LCOV - code coverage report
Current view: top level - src/backend/access/transam - xact.c (source / functions) Hit Total Coverage
Test: PostgreSQL 18devel Lines: 1602 1842 87.0 %
Date: 2025-04-01 14:15:22 Functions: 102 109 93.6 %
Legend: Lines: hit not hit

          Line data    Source code
       1             : /*-------------------------------------------------------------------------
       2             :  *
       3             :  * xact.c
       4             :  *    top level transaction system support routines
       5             :  *
       6             :  * See src/backend/access/transam/README for more information.
       7             :  *
       8             :  * Portions Copyright (c) 1996-2025, PostgreSQL Global Development Group
       9             :  * Portions Copyright (c) 1994, Regents of the University of California
      10             :  *
      11             :  *
      12             :  * IDENTIFICATION
      13             :  *    src/backend/access/transam/xact.c
      14             :  *
      15             :  *-------------------------------------------------------------------------
      16             :  */
      17             : 
      18             : #include "postgres.h"
      19             : 
      20             : #include <time.h>
      21             : #include <unistd.h>
      22             : 
      23             : #include "access/commit_ts.h"
      24             : #include "access/multixact.h"
      25             : #include "access/parallel.h"
      26             : #include "access/subtrans.h"
      27             : #include "access/transam.h"
      28             : #include "access/twophase.h"
      29             : #include "access/xact.h"
      30             : #include "access/xlog.h"
      31             : #include "access/xloginsert.h"
      32             : #include "access/xlogrecovery.h"
      33             : #include "access/xlogutils.h"
      34             : #include "catalog/index.h"
      35             : #include "catalog/namespace.h"
      36             : #include "catalog/pg_enum.h"
      37             : #include "catalog/storage.h"
      38             : #include "commands/async.h"
      39             : #include "commands/tablecmds.h"
      40             : #include "commands/trigger.h"
      41             : #include "common/pg_prng.h"
      42             : #include "executor/spi.h"
      43             : #include "libpq/be-fsstubs.h"
      44             : #include "libpq/pqsignal.h"
      45             : #include "miscadmin.h"
      46             : #include "pg_trace.h"
      47             : #include "pgstat.h"
      48             : #include "replication/logical.h"
      49             : #include "replication/logicallauncher.h"
      50             : #include "replication/logicalworker.h"
      51             : #include "replication/origin.h"
      52             : #include "replication/snapbuild.h"
      53             : #include "replication/syncrep.h"
      54             : #include "storage/aio_subsys.h"
      55             : #include "storage/condition_variable.h"
      56             : #include "storage/fd.h"
      57             : #include "storage/lmgr.h"
      58             : #include "storage/md.h"
      59             : #include "storage/predicate.h"
      60             : #include "storage/proc.h"
      61             : #include "storage/procarray.h"
      62             : #include "storage/sinvaladt.h"
      63             : #include "storage/smgr.h"
      64             : #include "utils/builtins.h"
      65             : #include "utils/combocid.h"
      66             : #include "utils/guc.h"
      67             : #include "utils/inval.h"
      68             : #include "utils/memutils.h"
      69             : #include "utils/relmapper.h"
      70             : #include "utils/snapmgr.h"
      71             : #include "utils/timeout.h"
      72             : #include "utils/timestamp.h"
      73             : #include "utils/typcache.h"
      74             : 
      75             : /*
      76             :  *  User-tweakable parameters
      77             :  */
      78             : int         DefaultXactIsoLevel = XACT_READ_COMMITTED;
      79             : int         XactIsoLevel = XACT_READ_COMMITTED;
      80             : 
      81             : bool        DefaultXactReadOnly = false;
      82             : bool        XactReadOnly;
      83             : 
      84             : bool        DefaultXactDeferrable = false;
      85             : bool        XactDeferrable;
      86             : 
      87             : int         synchronous_commit = SYNCHRONOUS_COMMIT_ON;
      88             : 
      89             : /*
      90             :  * CheckXidAlive is a xid value pointing to a possibly ongoing (sub)
      91             :  * transaction.  Currently, it is used in logical decoding.  It's possible
      92             :  * that such transactions can get aborted while the decoding is ongoing in
      93             :  * which case we skip decoding that particular transaction.  To ensure that we
      94             :  * check whether the CheckXidAlive is aborted after fetching the tuple from
      95             :  * system tables.  We also ensure that during logical decoding we never
      96             :  * directly access the tableam or heap APIs because we are checking for the
      97             :  * concurrent aborts only in systable_* APIs.
      98             :  */
      99             : TransactionId CheckXidAlive = InvalidTransactionId;
     100             : bool        bsysscan = false;
     101             : 
     102             : /*
     103             :  * When running as a parallel worker, we place only a single
     104             :  * TransactionStateData on the parallel worker's state stack, and the XID
     105             :  * reflected there will be that of the *innermost* currently-active
     106             :  * subtransaction in the backend that initiated parallelism.  However,
     107             :  * GetTopTransactionId() and TransactionIdIsCurrentTransactionId()
     108             :  * need to return the same answers in the parallel worker as they would have
     109             :  * in the user backend, so we need some additional bookkeeping.
     110             :  *
     111             :  * XactTopFullTransactionId stores the XID of our toplevel transaction, which
     112             :  * will be the same as TopTransactionStateData.fullTransactionId in an
     113             :  * ordinary backend; but in a parallel backend, which does not have the entire
     114             :  * transaction state, it will instead be copied from the backend that started
     115             :  * the parallel operation.
     116             :  *
     117             :  * nParallelCurrentXids will be 0 and ParallelCurrentXids NULL in an ordinary
     118             :  * backend, but in a parallel backend, nParallelCurrentXids will contain the
     119             :  * number of XIDs that need to be considered current, and ParallelCurrentXids
     120             :  * will contain the XIDs themselves.  This includes all XIDs that were current
     121             :  * or sub-committed in the parent at the time the parallel operation began.
     122             :  * The XIDs are stored sorted in numerical order (not logical order) to make
     123             :  * lookups as fast as possible.
     124             :  */
     125             : static FullTransactionId XactTopFullTransactionId = {InvalidTransactionId};
     126             : static int  nParallelCurrentXids = 0;
     127             : static TransactionId *ParallelCurrentXids;
     128             : 
     129             : /*
     130             :  * Miscellaneous flag bits to record events which occur on the top level
     131             :  * transaction. These flags are only persisted in MyXactFlags and are intended
     132             :  * so we remember to do certain things later on in the transaction. This is
     133             :  * globally accessible, so can be set from anywhere in the code that requires
     134             :  * recording flags.
     135             :  */
     136             : int         MyXactFlags;
     137             : 
     138             : /*
     139             :  *  transaction states - transaction state from server perspective
     140             :  */
     141             : typedef enum TransState
     142             : {
     143             :     TRANS_DEFAULT,              /* idle */
     144             :     TRANS_START,                /* transaction starting */
     145             :     TRANS_INPROGRESS,           /* inside a valid transaction */
     146             :     TRANS_COMMIT,               /* commit in progress */
     147             :     TRANS_ABORT,                /* abort in progress */
     148             :     TRANS_PREPARE,              /* prepare in progress */
     149             : } TransState;
     150             : 
     151             : /*
     152             :  *  transaction block states - transaction state of client queries
     153             :  *
     154             :  * Note: the subtransaction states are used only for non-topmost
     155             :  * transactions; the others appear only in the topmost transaction.
     156             :  */
     157             : typedef enum TBlockState
     158             : {
     159             :     /* not-in-transaction-block states */
     160             :     TBLOCK_DEFAULT,             /* idle */
     161             :     TBLOCK_STARTED,             /* running single-query transaction */
     162             : 
     163             :     /* transaction block states */
     164             :     TBLOCK_BEGIN,               /* starting transaction block */
     165             :     TBLOCK_INPROGRESS,          /* live transaction */
     166             :     TBLOCK_IMPLICIT_INPROGRESS, /* live transaction after implicit BEGIN */
     167             :     TBLOCK_PARALLEL_INPROGRESS, /* live transaction inside parallel worker */
     168             :     TBLOCK_END,                 /* COMMIT received */
     169             :     TBLOCK_ABORT,               /* failed xact, awaiting ROLLBACK */
     170             :     TBLOCK_ABORT_END,           /* failed xact, ROLLBACK received */
     171             :     TBLOCK_ABORT_PENDING,       /* live xact, ROLLBACK received */
     172             :     TBLOCK_PREPARE,             /* live xact, PREPARE received */
     173             : 
     174             :     /* subtransaction states */
     175             :     TBLOCK_SUBBEGIN,            /* starting a subtransaction */
     176             :     TBLOCK_SUBINPROGRESS,       /* live subtransaction */
     177             :     TBLOCK_SUBRELEASE,          /* RELEASE received */
     178             :     TBLOCK_SUBCOMMIT,           /* COMMIT received while TBLOCK_SUBINPROGRESS */
     179             :     TBLOCK_SUBABORT,            /* failed subxact, awaiting ROLLBACK */
     180             :     TBLOCK_SUBABORT_END,        /* failed subxact, ROLLBACK received */
     181             :     TBLOCK_SUBABORT_PENDING,    /* live subxact, ROLLBACK received */
     182             :     TBLOCK_SUBRESTART,          /* live subxact, ROLLBACK TO received */
     183             :     TBLOCK_SUBABORT_RESTART,    /* failed subxact, ROLLBACK TO received */
     184             : } TBlockState;
     185             : 
     186             : /*
     187             :  *  transaction state structure
     188             :  *
     189             :  * Note: parallelModeLevel counts the number of unmatched EnterParallelMode
     190             :  * calls done at this transaction level.  parallelChildXact is true if any
     191             :  * upper transaction level has nonzero parallelModeLevel.
     192             :  */
     193             : typedef struct TransactionStateData
     194             : {
     195             :     FullTransactionId fullTransactionId;    /* my FullTransactionId */
     196             :     SubTransactionId subTransactionId;  /* my subxact ID */
     197             :     char       *name;           /* savepoint name, if any */
     198             :     int         savepointLevel; /* savepoint level */
     199             :     TransState  state;          /* low-level state */
     200             :     TBlockState blockState;     /* high-level state */
     201             :     int         nestingLevel;   /* transaction nesting depth */
     202             :     int         gucNestLevel;   /* GUC context nesting depth */
     203             :     MemoryContext curTransactionContext;    /* my xact-lifetime context */
     204             :     ResourceOwner curTransactionOwner;  /* my query resources */
     205             :     MemoryContext priorContext; /* CurrentMemoryContext before xact started */
     206             :     TransactionId *childXids;   /* subcommitted child XIDs, in XID order */
     207             :     int         nChildXids;     /* # of subcommitted child XIDs */
     208             :     int         maxChildXids;   /* allocated size of childXids[] */
     209             :     Oid         prevUser;       /* previous CurrentUserId setting */
     210             :     int         prevSecContext; /* previous SecurityRestrictionContext */
     211             :     bool        prevXactReadOnly;   /* entry-time xact r/o state */
     212             :     bool        startedInRecovery;  /* did we start in recovery? */
     213             :     bool        didLogXid;      /* has xid been included in WAL record? */
     214             :     int         parallelModeLevel;  /* Enter/ExitParallelMode counter */
     215             :     bool        parallelChildXact;  /* is any parent transaction parallel? */
     216             :     bool        chain;          /* start a new block after this one */
     217             :     bool        topXidLogged;   /* for a subxact: is top-level XID logged? */
     218             :     struct TransactionStateData *parent;    /* back link to parent */
     219             : } TransactionStateData;
     220             : 
     221             : typedef TransactionStateData *TransactionState;
     222             : 
     223             : /*
     224             :  * Serialized representation used to transmit transaction state to parallel
     225             :  * workers through shared memory.
     226             :  */
     227             : typedef struct SerializedTransactionState
     228             : {
     229             :     int         xactIsoLevel;
     230             :     bool        xactDeferrable;
     231             :     FullTransactionId topFullTransactionId;
     232             :     FullTransactionId currentFullTransactionId;
     233             :     CommandId   currentCommandId;
     234             :     int         nParallelCurrentXids;
     235             :     TransactionId parallelCurrentXids[FLEXIBLE_ARRAY_MEMBER];
     236             : } SerializedTransactionState;
     237             : 
     238             : /* The size of SerializedTransactionState, not including the final array. */
     239             : #define SerializedTransactionStateHeaderSize \
     240             :     offsetof(SerializedTransactionState, parallelCurrentXids)
     241             : 
     242             : /*
     243             :  * CurrentTransactionState always points to the current transaction state
     244             :  * block.  It will point to TopTransactionStateData when not in a
     245             :  * transaction at all, or when in a top-level transaction.
     246             :  */
     247             : static TransactionStateData TopTransactionStateData = {
     248             :     .state = TRANS_DEFAULT,
     249             :     .blockState = TBLOCK_DEFAULT,
     250             :     .topXidLogged = false,
     251             : };
     252             : 
     253             : /*
     254             :  * unreportedXids holds XIDs of all subtransactions that have not yet been
     255             :  * reported in an XLOG_XACT_ASSIGNMENT record.
     256             :  */
     257             : static int  nUnreportedXids;
     258             : static TransactionId unreportedXids[PGPROC_MAX_CACHED_SUBXIDS];
     259             : 
     260             : static TransactionState CurrentTransactionState = &TopTransactionStateData;
     261             : 
     262             : /*
     263             :  * The subtransaction ID and command ID assignment counters are global
     264             :  * to a whole transaction, so we do not keep them in the state stack.
     265             :  */
     266             : static SubTransactionId currentSubTransactionId;
     267             : static CommandId currentCommandId;
     268             : static bool currentCommandIdUsed;
     269             : 
     270             : /*
     271             :  * xactStartTimestamp is the value of transaction_timestamp().
     272             :  * stmtStartTimestamp is the value of statement_timestamp().
     273             :  * xactStopTimestamp is the time at which we log a commit / abort WAL record,
     274             :  * or if that was skipped, the time of the first subsequent
     275             :  * GetCurrentTransactionStopTimestamp() call.
     276             :  *
     277             :  * These do not change as we enter and exit subtransactions, so we don't
     278             :  * keep them inside the TransactionState stack.
     279             :  */
     280             : static TimestampTz xactStartTimestamp;
     281             : static TimestampTz stmtStartTimestamp;
     282             : static TimestampTz xactStopTimestamp;
     283             : 
     284             : /*
     285             :  * GID to be used for preparing the current transaction.  This is also
     286             :  * global to a whole transaction, so we don't keep it in the state stack.
     287             :  */
     288             : static char *prepareGID;
     289             : 
     290             : /*
     291             :  * Some commands want to force synchronous commit.
     292             :  */
     293             : static bool forceSyncCommit = false;
     294             : 
     295             : /* Flag for logging statements in a transaction. */
     296             : bool        xact_is_sampled = false;
     297             : 
     298             : /*
     299             :  * Private context for transaction-abort work --- we reserve space for this
     300             :  * at startup to ensure that AbortTransaction and AbortSubTransaction can work
     301             :  * when we've run out of memory.
     302             :  */
     303             : static MemoryContext TransactionAbortContext = NULL;
     304             : 
     305             : /*
     306             :  * List of add-on start- and end-of-xact callbacks
     307             :  */
     308             : typedef struct XactCallbackItem
     309             : {
     310             :     struct XactCallbackItem *next;
     311             :     XactCallback callback;
     312             :     void       *arg;
     313             : } XactCallbackItem;
     314             : 
     315             : static XactCallbackItem *Xact_callbacks = NULL;
     316             : 
     317             : /*
     318             :  * List of add-on start- and end-of-subxact callbacks
     319             :  */
     320             : typedef struct SubXactCallbackItem
     321             : {
     322             :     struct SubXactCallbackItem *next;
     323             :     SubXactCallback callback;
     324             :     void       *arg;
     325             : } SubXactCallbackItem;
     326             : 
     327             : static SubXactCallbackItem *SubXact_callbacks = NULL;
     328             : 
     329             : 
     330             : /* local function prototypes */
     331             : static void AssignTransactionId(TransactionState s);
     332             : static void AbortTransaction(void);
     333             : static void AtAbort_Memory(void);
     334             : static void AtCleanup_Memory(void);
     335             : static void AtAbort_ResourceOwner(void);
     336             : static void AtCCI_LocalCache(void);
     337             : static void AtCommit_Memory(void);
     338             : static void AtStart_Cache(void);
     339             : static void AtStart_Memory(void);
     340             : static void AtStart_ResourceOwner(void);
     341             : static void CallXactCallbacks(XactEvent event);
     342             : static void CallSubXactCallbacks(SubXactEvent event,
     343             :                                  SubTransactionId mySubid,
     344             :                                  SubTransactionId parentSubid);
     345             : static void CleanupTransaction(void);
     346             : static void CheckTransactionBlock(bool isTopLevel, bool throwError,
     347             :                                   const char *stmtType);
     348             : static void CommitTransaction(void);
     349             : static TransactionId RecordTransactionAbort(bool isSubXact);
     350             : static void StartTransaction(void);
     351             : 
     352             : static bool CommitTransactionCommandInternal(void);
     353             : static bool AbortCurrentTransactionInternal(void);
     354             : 
     355             : static void StartSubTransaction(void);
     356             : static void CommitSubTransaction(void);
     357             : static void AbortSubTransaction(void);
     358             : static void CleanupSubTransaction(void);
     359             : static void PushTransaction(void);
     360             : static void PopTransaction(void);
     361             : 
     362             : static void AtSubAbort_Memory(void);
     363             : static void AtSubCleanup_Memory(void);
     364             : static void AtSubAbort_ResourceOwner(void);
     365             : static void AtSubCommit_Memory(void);
     366             : static void AtSubStart_Memory(void);
     367             : static void AtSubStart_ResourceOwner(void);
     368             : 
     369             : static void ShowTransactionState(const char *str);
     370             : static void ShowTransactionStateRec(const char *str, TransactionState s);
     371             : static const char *BlockStateAsString(TBlockState blockState);
     372             : static const char *TransStateAsString(TransState state);
     373             : 
     374             : 
     375             : /* ----------------------------------------------------------------
     376             :  *  transaction state accessors
     377             :  * ----------------------------------------------------------------
     378             :  */
     379             : 
     380             : /*
     381             :  *  IsTransactionState
     382             :  *
     383             :  *  This returns true if we are inside a valid transaction; that is,
     384             :  *  it is safe to initiate database access, take heavyweight locks, etc.
     385             :  */
     386             : bool
     387     2051948 : IsTransactionState(void)
     388             : {
     389     2051948 :     TransactionState s = CurrentTransactionState;
     390             : 
     391             :     /*
     392             :      * TRANS_DEFAULT and TRANS_ABORT are obviously unsafe states.  However, we
     393             :      * also reject the startup/shutdown states TRANS_START, TRANS_COMMIT,
     394             :      * TRANS_PREPARE since it might be too soon or too late within those
     395             :      * transition states to do anything interesting.  Hence, the only "valid"
     396             :      * state is TRANS_INPROGRESS.
     397             :      */
     398     2051948 :     return (s->state == TRANS_INPROGRESS);
     399             : }
     400             : 
     401             : /*
     402             :  *  IsAbortedTransactionBlockState
     403             :  *
     404             :  *  This returns true if we are within an aborted transaction block.
     405             :  */
     406             : bool
     407     1473648 : IsAbortedTransactionBlockState(void)
     408             : {
     409     1473648 :     TransactionState s = CurrentTransactionState;
     410             : 
     411     1473648 :     if (s->blockState == TBLOCK_ABORT ||
     412     1470698 :         s->blockState == TBLOCK_SUBABORT)
     413        3526 :         return true;
     414             : 
     415     1470122 :     return false;
     416             : }
     417             : 
     418             : 
     419             : /*
     420             :  *  GetTopTransactionId
     421             :  *
     422             :  * This will return the XID of the main transaction, assigning one if
     423             :  * it's not yet set.  Be careful to call this only inside a valid xact.
     424             :  */
     425             : TransactionId
     426       58858 : GetTopTransactionId(void)
     427             : {
     428       58858 :     if (!FullTransactionIdIsValid(XactTopFullTransactionId))
     429        1118 :         AssignTransactionId(&TopTransactionStateData);
     430       58858 :     return XidFromFullTransactionId(XactTopFullTransactionId);
     431             : }
     432             : 
     433             : /*
     434             :  *  GetTopTransactionIdIfAny
     435             :  *
     436             :  * This will return the XID of the main transaction, if one is assigned.
     437             :  * It will return InvalidTransactionId if we are not currently inside a
     438             :  * transaction, or inside a transaction that hasn't yet been assigned an XID.
     439             :  */
     440             : TransactionId
     441    87793344 : GetTopTransactionIdIfAny(void)
     442             : {
     443    87793344 :     return XidFromFullTransactionId(XactTopFullTransactionId);
     444             : }
     445             : 
     446             : /*
     447             :  *  GetCurrentTransactionId
     448             :  *
     449             :  * This will return the XID of the current transaction (main or sub
     450             :  * transaction), assigning one if it's not yet set.  Be careful to call this
     451             :  * only inside a valid xact.
     452             :  */
     453             : TransactionId
     454    20626722 : GetCurrentTransactionId(void)
     455             : {
     456    20626722 :     TransactionState s = CurrentTransactionState;
     457             : 
     458    20626722 :     if (!FullTransactionIdIsValid(s->fullTransactionId))
     459      251064 :         AssignTransactionId(s);
     460    20626710 :     return XidFromFullTransactionId(s->fullTransactionId);
     461             : }
     462             : 
     463             : /*
     464             :  *  GetCurrentTransactionIdIfAny
     465             :  *
     466             :  * This will return the XID of the current sub xact, if one is assigned.
     467             :  * It will return InvalidTransactionId if we are not currently inside a
     468             :  * transaction, or inside a transaction that hasn't been assigned an XID yet.
     469             :  */
     470             : TransactionId
     471    28482896 : GetCurrentTransactionIdIfAny(void)
     472             : {
     473    28482896 :     return XidFromFullTransactionId(CurrentTransactionState->fullTransactionId);
     474             : }
     475             : 
     476             : /*
     477             :  *  GetTopFullTransactionId
     478             :  *
     479             :  * This will return the FullTransactionId of the main transaction, assigning
     480             :  * one if it's not yet set.  Be careful to call this only inside a valid xact.
     481             :  */
     482             : FullTransactionId
     483        5726 : GetTopFullTransactionId(void)
     484             : {
     485        5726 :     if (!FullTransactionIdIsValid(XactTopFullTransactionId))
     486        4156 :         AssignTransactionId(&TopTransactionStateData);
     487        5726 :     return XactTopFullTransactionId;
     488             : }
     489             : 
     490             : /*
     491             :  *  GetTopFullTransactionIdIfAny
     492             :  *
     493             :  * This will return the FullTransactionId of the main transaction, if one is
     494             :  * assigned.  It will return InvalidFullTransactionId if we are not currently
     495             :  * inside a transaction, or inside a transaction that hasn't yet been assigned
     496             :  * one.
     497             :  */
     498             : FullTransactionId
     499          24 : GetTopFullTransactionIdIfAny(void)
     500             : {
     501          24 :     return XactTopFullTransactionId;
     502             : }
     503             : 
     504             : /*
     505             :  *  GetCurrentFullTransactionId
     506             :  *
     507             :  * This will return the FullTransactionId of the current transaction (main or
     508             :  * sub transaction), assigning one if it's not yet set.  Be careful to call
     509             :  * this only inside a valid xact.
     510             :  */
     511             : FullTransactionId
     512           0 : GetCurrentFullTransactionId(void)
     513             : {
     514           0 :     TransactionState s = CurrentTransactionState;
     515             : 
     516           0 :     if (!FullTransactionIdIsValid(s->fullTransactionId))
     517           0 :         AssignTransactionId(s);
     518           0 :     return s->fullTransactionId;
     519             : }
     520             : 
     521             : /*
     522             :  *  GetCurrentFullTransactionIdIfAny
     523             :  *
     524             :  * This will return the FullTransactionId of the current sub xact, if one is
     525             :  * assigned.  It will return InvalidFullTransactionId if we are not currently
     526             :  * inside a transaction, or inside a transaction that hasn't been assigned one
     527             :  * yet.
     528             :  */
     529             : FullTransactionId
     530           0 : GetCurrentFullTransactionIdIfAny(void)
     531             : {
     532           0 :     return CurrentTransactionState->fullTransactionId;
     533             : }
     534             : 
     535             : /*
     536             :  *  MarkCurrentTransactionIdLoggedIfAny
     537             :  *
     538             :  * Remember that the current xid - if it is assigned - now has been wal logged.
     539             :  */
     540             : void
     541    28406486 : MarkCurrentTransactionIdLoggedIfAny(void)
     542             : {
     543    28406486 :     if (FullTransactionIdIsValid(CurrentTransactionState->fullTransactionId))
     544    27906672 :         CurrentTransactionState->didLogXid = true;
     545    28406486 : }
     546             : 
     547             : /*
     548             :  * IsSubxactTopXidLogPending
     549             :  *
     550             :  * This is used to decide whether we need to WAL log the top-level XID for
     551             :  * operation in a subtransaction.  We require that for logical decoding, see
     552             :  * LogicalDecodingProcessRecord.
     553             :  *
     554             :  * This returns true if wal_level >= logical and we are inside a valid
     555             :  * subtransaction, for which the assignment was not yet written to any WAL
     556             :  * record.
     557             :  */
     558             : bool
     559    28420966 : IsSubxactTopXidLogPending(void)
     560             : {
     561             :     /* check whether it is already logged */
     562    28420966 :     if (CurrentTransactionState->topXidLogged)
     563      204250 :         return false;
     564             : 
     565             :     /* wal_level has to be logical */
     566    28216716 :     if (!XLogLogicalInfoActive())
     567    27154352 :         return false;
     568             : 
     569             :     /* we need to be in a transaction state */
     570     1062364 :     if (!IsTransactionState())
     571        7370 :         return false;
     572             : 
     573             :     /* it has to be a subtransaction */
     574     1054994 :     if (!IsSubTransaction())
     575     1054538 :         return false;
     576             : 
     577             :     /* the subtransaction has to have a XID assigned */
     578         456 :     if (!TransactionIdIsValid(GetCurrentTransactionIdIfAny()))
     579          14 :         return false;
     580             : 
     581         442 :     return true;
     582             : }
     583             : 
     584             : /*
     585             :  * MarkSubxactTopXidLogged
     586             :  *
     587             :  * Remember that the top transaction id for the current subtransaction is WAL
     588             :  * logged now.
     589             :  */
     590             : void
     591         438 : MarkSubxactTopXidLogged(void)
     592             : {
     593             :     Assert(IsSubxactTopXidLogPending());
     594             : 
     595         438 :     CurrentTransactionState->topXidLogged = true;
     596         438 : }
     597             : 
     598             : /*
     599             :  *  GetStableLatestTransactionId
     600             :  *
     601             :  * Get the transaction's XID if it has one, else read the next-to-be-assigned
     602             :  * XID.  Once we have a value, return that same value for the remainder of the
     603             :  * current transaction.  This is meant to provide the reference point for the
     604             :  * age(xid) function, but might be useful for other maintenance tasks as well.
     605             :  */
     606             : TransactionId
     607         290 : GetStableLatestTransactionId(void)
     608             : {
     609             :     static LocalTransactionId lxid = InvalidLocalTransactionId;
     610             :     static TransactionId stablexid = InvalidTransactionId;
     611             : 
     612         290 :     if (lxid != MyProc->vxid.lxid)
     613             :     {
     614          24 :         lxid = MyProc->vxid.lxid;
     615          24 :         stablexid = GetTopTransactionIdIfAny();
     616          24 :         if (!TransactionIdIsValid(stablexid))
     617          24 :             stablexid = ReadNextTransactionId();
     618             :     }
     619             : 
     620             :     Assert(TransactionIdIsValid(stablexid));
     621             : 
     622         290 :     return stablexid;
     623             : }
     624             : 
     625             : /*
     626             :  * AssignTransactionId
     627             :  *
     628             :  * Assigns a new permanent FullTransactionId to the given TransactionState.
     629             :  * We do not assign XIDs to transactions until/unless this is called.
     630             :  * Also, any parent TransactionStates that don't yet have XIDs are assigned
     631             :  * one; this maintains the invariant that a child transaction has an XID
     632             :  * following its parent's.
     633             :  */
     634             : static void
     635      258614 : AssignTransactionId(TransactionState s)
     636             : {
     637      258614 :     bool        isSubXact = (s->parent != NULL);
     638             :     ResourceOwner currentOwner;
     639      258614 :     bool        log_unknown_top = false;
     640             : 
     641             :     /* Assert that caller didn't screw up */
     642             :     Assert(!FullTransactionIdIsValid(s->fullTransactionId));
     643             :     Assert(s->state == TRANS_INPROGRESS);
     644             : 
     645             :     /*
     646             :      * Workers synchronize transaction state at the beginning of each parallel
     647             :      * operation, so we can't account for new XIDs at this point.
     648             :      */
     649      258614 :     if (IsInParallelMode() || IsParallelWorker())
     650           0 :         ereport(ERROR,
     651             :                 (errcode(ERRCODE_INVALID_TRANSACTION_STATE),
     652             :                  errmsg("cannot assign transaction IDs during a parallel operation")));
     653             : 
     654             :     /*
     655             :      * Ensure parent(s) have XIDs, so that a child always has an XID later
     656             :      * than its parent.  Mustn't recurse here, or we might get a stack
     657             :      * overflow if we're at the bottom of a huge stack of subtransactions none
     658             :      * of which have XIDs yet.
     659             :      */
     660      258614 :     if (isSubXact && !FullTransactionIdIsValid(s->parent->fullTransactionId))
     661             :     {
     662        1138 :         TransactionState p = s->parent;
     663             :         TransactionState *parents;
     664        1138 :         size_t      parentOffset = 0;
     665             : 
     666        1138 :         parents = palloc(sizeof(TransactionState) * s->nestingLevel);
     667        3414 :         while (p != NULL && !FullTransactionIdIsValid(p->fullTransactionId))
     668             :         {
     669        2276 :             parents[parentOffset++] = p;
     670        2276 :             p = p->parent;
     671             :         }
     672             : 
     673             :         /*
     674             :          * This is technically a recursive call, but the recursion will never
     675             :          * be more than one layer deep.
     676             :          */
     677        3414 :         while (parentOffset != 0)
     678        2276 :             AssignTransactionId(parents[--parentOffset]);
     679             : 
     680        1138 :         pfree(parents);
     681             :     }
     682             : 
     683             :     /*
     684             :      * When wal_level=logical, guarantee that a subtransaction's xid can only
     685             :      * be seen in the WAL stream if its toplevel xid has been logged before.
     686             :      * If necessary we log an xact_assignment record with fewer than
     687             :      * PGPROC_MAX_CACHED_SUBXIDS. Note that it is fine if didLogXid isn't set
     688             :      * for a transaction even though it appears in a WAL record, we just might
     689             :      * superfluously log something. That can happen when an xid is included
     690             :      * somewhere inside a wal record, but not in XLogRecord->xl_xid, like in
     691             :      * xl_standby_locks.
     692             :      */
     693      258614 :     if (isSubXact && XLogLogicalInfoActive() &&
     694         600 :         !TopTransactionStateData.didLogXid)
     695          48 :         log_unknown_top = true;
     696             : 
     697             :     /*
     698             :      * Generate a new FullTransactionId and record its xid in PGPROC and
     699             :      * pg_subtrans.
     700             :      *
     701             :      * NB: we must make the subtrans entry BEFORE the Xid appears anywhere in
     702             :      * shared storage other than PGPROC; because if there's no room for it in
     703             :      * PGPROC, the subtrans entry is needed to ensure that other backends see
     704             :      * the Xid as "running".  See GetNewTransactionId.
     705             :      */
     706      258614 :     s->fullTransactionId = GetNewTransactionId(isSubXact);
     707      258602 :     if (!isSubXact)
     708      249970 :         XactTopFullTransactionId = s->fullTransactionId;
     709             : 
     710      258602 :     if (isSubXact)
     711        8632 :         SubTransSetParent(XidFromFullTransactionId(s->fullTransactionId),
     712        8632 :                           XidFromFullTransactionId(s->parent->fullTransactionId));
     713             : 
     714             :     /*
     715             :      * If it's a top-level transaction, the predicate locking system needs to
     716             :      * be told about it too.
     717             :      */
     718      258602 :     if (!isSubXact)
     719      249970 :         RegisterPredicateLockingXid(XidFromFullTransactionId(s->fullTransactionId));
     720             : 
     721             :     /*
     722             :      * Acquire lock on the transaction XID.  (We assume this cannot block.) We
     723             :      * have to ensure that the lock is assigned to the transaction's own
     724             :      * ResourceOwner.
     725             :      */
     726      258602 :     currentOwner = CurrentResourceOwner;
     727      258602 :     CurrentResourceOwner = s->curTransactionOwner;
     728             : 
     729      258602 :     XactLockTableInsert(XidFromFullTransactionId(s->fullTransactionId));
     730             : 
     731      258602 :     CurrentResourceOwner = currentOwner;
     732             : 
     733             :     /*
     734             :      * Every PGPROC_MAX_CACHED_SUBXIDS assigned transaction ids within each
     735             :      * top-level transaction we issue a WAL record for the assignment. We
     736             :      * include the top-level xid and all the subxids that have not yet been
     737             :      * reported using XLOG_XACT_ASSIGNMENT records.
     738             :      *
     739             :      * This is required to limit the amount of shared memory required in a hot
     740             :      * standby server to keep track of in-progress XIDs. See notes for
     741             :      * RecordKnownAssignedTransactionIds().
     742             :      *
     743             :      * We don't keep track of the immediate parent of each subxid, only the
     744             :      * top-level transaction that each subxact belongs to. This is correct in
     745             :      * recovery only because aborted subtransactions are separately WAL
     746             :      * logged.
     747             :      *
     748             :      * This is correct even for the case where several levels above us didn't
     749             :      * have an xid assigned as we recursed up to them beforehand.
     750             :      */
     751      258602 :     if (isSubXact && XLogStandbyInfoActive())
     752             :     {
     753        7656 :         unreportedXids[nUnreportedXids] = XidFromFullTransactionId(s->fullTransactionId);
     754        7656 :         nUnreportedXids++;
     755             : 
     756             :         /*
     757             :          * ensure this test matches similar one in
     758             :          * RecoverPreparedTransactions()
     759             :          */
     760        7656 :         if (nUnreportedXids >= PGPROC_MAX_CACHED_SUBXIDS ||
     761             :             log_unknown_top)
     762             :         {
     763             :             xl_xact_assignment xlrec;
     764             : 
     765             :             /*
     766             :              * xtop is always set by now because we recurse up transaction
     767             :              * stack to the highest unassigned xid and then come back down
     768             :              */
     769         132 :             xlrec.xtop = GetTopTransactionId();
     770             :             Assert(TransactionIdIsValid(xlrec.xtop));
     771         132 :             xlrec.nsubxacts = nUnreportedXids;
     772             : 
     773         132 :             XLogBeginInsert();
     774         132 :             XLogRegisterData(&xlrec, MinSizeOfXactAssignment);
     775         132 :             XLogRegisterData(unreportedXids,
     776             :                              nUnreportedXids * sizeof(TransactionId));
     777             : 
     778         132 :             (void) XLogInsert(RM_XACT_ID, XLOG_XACT_ASSIGNMENT);
     779             : 
     780         132 :             nUnreportedXids = 0;
     781             :             /* mark top, not current xact as having been logged */
     782         132 :             TopTransactionStateData.didLogXid = true;
     783             :         }
     784             :     }
     785      258602 : }
     786             : 
     787             : /*
     788             :  *  GetCurrentSubTransactionId
     789             :  */
     790             : SubTransactionId
     791    17831228 : GetCurrentSubTransactionId(void)
     792             : {
     793    17831228 :     TransactionState s = CurrentTransactionState;
     794             : 
     795    17831228 :     return s->subTransactionId;
     796             : }
     797             : 
     798             : /*
     799             :  *  SubTransactionIsActive
     800             :  *
     801             :  * Test if the specified subxact ID is still active.  Note caller is
     802             :  * responsible for checking whether this ID is relevant to the current xact.
     803             :  */
     804             : bool
     805       92542 : SubTransactionIsActive(SubTransactionId subxid)
     806             : {
     807             :     TransactionState s;
     808             : 
     809       92554 :     for (s = CurrentTransactionState; s != NULL; s = s->parent)
     810             :     {
     811       92554 :         if (s->state == TRANS_ABORT)
     812           0 :             continue;
     813       92554 :         if (s->subTransactionId == subxid)
     814       92542 :             return true;
     815             :     }
     816           0 :     return false;
     817             : }
     818             : 
     819             : 
     820             : /*
     821             :  *  GetCurrentCommandId
     822             :  *
     823             :  * "used" must be true if the caller intends to use the command ID to mark
     824             :  * inserted/updated/deleted tuples.  false means the ID is being fetched
     825             :  * for read-only purposes (ie, as a snapshot validity cutoff).  See
     826             :  * CommandCounterIncrement() for discussion.
     827             :  */
     828             : CommandId
     829    10809868 : GetCurrentCommandId(bool used)
     830             : {
     831             :     /* this is global to a transaction, not subtransaction-local */
     832    10809868 :     if (used)
     833             :     {
     834             :         /*
     835             :          * Forbid setting currentCommandIdUsed in a parallel worker, because
     836             :          * we have no provision for communicating this back to the leader.  We
     837             :          * could relax this restriction when currentCommandIdUsed was already
     838             :          * true at the start of the parallel operation.
     839             :          */
     840     6488408 :         if (IsParallelWorker())
     841           0 :             ereport(ERROR,
     842             :                     (errcode(ERRCODE_INVALID_TRANSACTION_STATE),
     843             :                      errmsg("cannot modify data in a parallel worker")));
     844             : 
     845     6488408 :         currentCommandIdUsed = true;
     846             :     }
     847    10809868 :     return currentCommandId;
     848             : }
     849             : 
     850             : /*
     851             :  *  SetParallelStartTimestamps
     852             :  *
     853             :  * In a parallel worker, we should inherit the parent transaction's
     854             :  * timestamps rather than setting our own.  The parallel worker
     855             :  * infrastructure must call this to provide those values before
     856             :  * calling StartTransaction() or SetCurrentStatementStartTimestamp().
     857             :  */
     858             : void
     859        2746 : SetParallelStartTimestamps(TimestampTz xact_ts, TimestampTz stmt_ts)
     860             : {
     861             :     Assert(IsParallelWorker());
     862        2746 :     xactStartTimestamp = xact_ts;
     863        2746 :     stmtStartTimestamp = stmt_ts;
     864        2746 : }
     865             : 
     866             : /*
     867             :  *  GetCurrentTransactionStartTimestamp
     868             :  */
     869             : TimestampTz
     870       85950 : GetCurrentTransactionStartTimestamp(void)
     871             : {
     872       85950 :     return xactStartTimestamp;
     873             : }
     874             : 
     875             : /*
     876             :  *  GetCurrentStatementStartTimestamp
     877             :  */
     878             : TimestampTz
     879     2254738 : GetCurrentStatementStartTimestamp(void)
     880             : {
     881     2254738 :     return stmtStartTimestamp;
     882             : }
     883             : 
     884             : /*
     885             :  *  GetCurrentTransactionStopTimestamp
     886             :  *
     887             :  * If the transaction stop time hasn't already been set, which can happen if
     888             :  * we decided we don't need to log an XLOG record, set xactStopTimestamp.
     889             :  */
     890             : TimestampTz
     891     2008294 : GetCurrentTransactionStopTimestamp(void)
     892             : {
     893     2008294 :     TransactionState s PG_USED_FOR_ASSERTS_ONLY = CurrentTransactionState;
     894             : 
     895             :     /* should only be called after commit / abort processing */
     896             :     Assert(s->state == TRANS_DEFAULT ||
     897             :            s->state == TRANS_COMMIT ||
     898             :            s->state == TRANS_ABORT ||
     899             :            s->state == TRANS_PREPARE);
     900             : 
     901     2008294 :     if (xactStopTimestamp == 0)
     902      561554 :         xactStopTimestamp = GetCurrentTimestamp();
     903             : 
     904     2008294 :     return xactStopTimestamp;
     905             : }
     906             : 
     907             : /*
     908             :  *  SetCurrentStatementStartTimestamp
     909             :  *
     910             :  * In a parallel worker, this should already have been provided by a call
     911             :  * to SetParallelStartTimestamps().
     912             :  */
     913             : void
     914     1152868 : SetCurrentStatementStartTimestamp(void)
     915             : {
     916     1152868 :     if (!IsParallelWorker())
     917     1150122 :         stmtStartTimestamp = GetCurrentTimestamp();
     918             :     else
     919             :         Assert(stmtStartTimestamp != 0);
     920     1152868 : }
     921             : 
     922             : /*
     923             :  *  GetCurrentTransactionNestLevel
     924             :  *
     925             :  * Note: this will return zero when not inside any transaction, one when
     926             :  * inside a top-level transaction, etc.
     927             :  */
     928             : int
     929    32926322 : GetCurrentTransactionNestLevel(void)
     930             : {
     931    32926322 :     TransactionState s = CurrentTransactionState;
     932             : 
     933    32926322 :     return s->nestingLevel;
     934             : }
     935             : 
     936             : 
     937             : /*
     938             :  *  TransactionIdIsCurrentTransactionId
     939             :  */
     940             : bool
     941    87921048 : TransactionIdIsCurrentTransactionId(TransactionId xid)
     942             : {
     943             :     TransactionState s;
     944             : 
     945             :     /*
     946             :      * We always say that BootstrapTransactionId is "not my transaction ID"
     947             :      * even when it is (ie, during bootstrap).  Along with the fact that
     948             :      * transam.c always treats BootstrapTransactionId as already committed,
     949             :      * this causes the heapam_visibility.c routines to see all tuples as
     950             :      * committed, which is what we need during bootstrap.  (Bootstrap mode
     951             :      * only inserts tuples, it never updates or deletes them, so all tuples
     952             :      * can be presumed good immediately.)
     953             :      *
     954             :      * Likewise, InvalidTransactionId and FrozenTransactionId are certainly
     955             :      * not my transaction ID, so we can just return "false" immediately for
     956             :      * any non-normal XID.
     957             :      */
     958    87921048 :     if (!TransactionIdIsNormal(xid))
     959     1145296 :         return false;
     960             : 
     961    86775752 :     if (TransactionIdEquals(xid, GetTopTransactionIdIfAny()))
     962    54678694 :         return true;
     963             : 
     964             :     /*
     965             :      * In parallel workers, the XIDs we must consider as current are stored in
     966             :      * ParallelCurrentXids rather than the transaction-state stack.  Note that
     967             :      * the XIDs in this array are sorted numerically rather than according to
     968             :      * transactionIdPrecedes order.
     969             :      */
     970    32097058 :     if (nParallelCurrentXids > 0)
     971             :     {
     972             :         int         low,
     973             :                     high;
     974             : 
     975     3692340 :         low = 0;
     976     3692340 :         high = nParallelCurrentXids - 1;
     977    14595150 :         while (low <= high)
     978             :         {
     979             :             int         middle;
     980             :             TransactionId probe;
     981             : 
     982    14508132 :             middle = low + (high - low) / 2;
     983    14508132 :             probe = ParallelCurrentXids[middle];
     984    14508132 :             if (probe == xid)
     985     3605322 :                 return true;
     986    10902810 :             else if (probe < xid)
     987    10815824 :                 low = middle + 1;
     988             :             else
     989       86986 :                 high = middle - 1;
     990             :         }
     991       87018 :         return false;
     992             :     }
     993             : 
     994             :     /*
     995             :      * We will return true for the Xid of the current subtransaction, any of
     996             :      * its subcommitted children, any of its parents, or any of their
     997             :      * previously subcommitted children.  However, a transaction being aborted
     998             :      * is no longer "current", even though it may still have an entry on the
     999             :      * state stack.
    1000             :      */
    1001    56861576 :     for (s = CurrentTransactionState; s != NULL; s = s->parent)
    1002             :     {
    1003             :         int         low,
    1004             :                     high;
    1005             : 
    1006    28528910 :         if (s->state == TRANS_ABORT)
    1007           0 :             continue;
    1008    28528910 :         if (!FullTransactionIdIsValid(s->fullTransactionId))
    1009    21853734 :             continue;           /* it can't have any child XIDs either */
    1010     6675176 :         if (TransactionIdEquals(xid, XidFromFullTransactionId(s->fullTransactionId)))
    1011       68968 :             return true;
    1012             :         /* As the childXids array is ordered, we can use binary search */
    1013     6606208 :         low = 0;
    1014     6606208 :         high = s->nChildXids - 1;
    1015     6607992 :         while (low <= high)
    1016             :         {
    1017             :             int         middle;
    1018             :             TransactionId probe;
    1019             : 
    1020        4868 :             middle = low + (high - low) / 2;
    1021        4868 :             probe = s->childXids[middle];
    1022        4868 :             if (TransactionIdEquals(probe, xid))
    1023        3084 :                 return true;
    1024        1784 :             else if (TransactionIdPrecedes(probe, xid))
    1025        1606 :                 low = middle + 1;
    1026             :             else
    1027         178 :                 high = middle - 1;
    1028             :         }
    1029             :     }
    1030             : 
    1031    28332666 :     return false;
    1032             : }
    1033             : 
    1034             : /*
    1035             :  *  TransactionStartedDuringRecovery
    1036             :  *
    1037             :  * Returns true if the current transaction started while recovery was still
    1038             :  * in progress. Recovery might have ended since so RecoveryInProgress() might
    1039             :  * return false already.
    1040             :  */
    1041             : bool
    1042    13773958 : TransactionStartedDuringRecovery(void)
    1043             : {
    1044    13773958 :     return CurrentTransactionState->startedInRecovery;
    1045             : }
    1046             : 
    1047             : /*
    1048             :  *  EnterParallelMode
    1049             :  */
    1050             : void
    1051        6366 : EnterParallelMode(void)
    1052             : {
    1053        6366 :     TransactionState s = CurrentTransactionState;
    1054             : 
    1055             :     Assert(s->parallelModeLevel >= 0);
    1056             : 
    1057        6366 :     ++s->parallelModeLevel;
    1058        6366 : }
    1059             : 
    1060             : /*
    1061             :  *  ExitParallelMode
    1062             :  */
    1063             : void
    1064        3608 : ExitParallelMode(void)
    1065             : {
    1066        3608 :     TransactionState s = CurrentTransactionState;
    1067             : 
    1068             :     Assert(s->parallelModeLevel > 0);
    1069             :     Assert(s->parallelModeLevel > 1 || s->parallelChildXact ||
    1070             :            !ParallelContextActive());
    1071             : 
    1072        3608 :     --s->parallelModeLevel;
    1073        3608 : }
    1074             : 
    1075             : /*
    1076             :  *  IsInParallelMode
    1077             :  *
    1078             :  * Are we in a parallel operation, as either the leader or a worker?  Check
    1079             :  * this to prohibit operations that change backend-local state expected to
    1080             :  * match across all workers.  Mere caches usually don't require such a
    1081             :  * restriction.  State modified in a strict push/pop fashion, such as the
    1082             :  * active snapshot stack, is often fine.
    1083             :  *
    1084             :  * We say we are in parallel mode if we are in a subxact of a transaction
    1085             :  * that's initiated a parallel operation; for most purposes that context
    1086             :  * has all the same restrictions.
    1087             :  */
    1088             : bool
    1089    57318390 : IsInParallelMode(void)
    1090             : {
    1091    57318390 :     TransactionState s = CurrentTransactionState;
    1092             : 
    1093    57318390 :     return s->parallelModeLevel != 0 || s->parallelChildXact;
    1094             : }
    1095             : 
    1096             : /*
    1097             :  *  CommandCounterIncrement
    1098             :  */
    1099             : void
    1100     2165254 : CommandCounterIncrement(void)
    1101             : {
    1102             :     /*
    1103             :      * If the current value of the command counter hasn't been "used" to mark
    1104             :      * tuples, we need not increment it, since there's no need to distinguish
    1105             :      * a read-only command from others.  This helps postpone command counter
    1106             :      * overflow, and keeps no-op CommandCounterIncrement operations cheap.
    1107             :      */
    1108     2165254 :     if (currentCommandIdUsed)
    1109             :     {
    1110             :         /*
    1111             :          * Workers synchronize transaction state at the beginning of each
    1112             :          * parallel operation, so we can't account for new commands after that
    1113             :          * point.
    1114             :          */
    1115     1092618 :         if (IsInParallelMode() || IsParallelWorker())
    1116           0 :             ereport(ERROR,
    1117             :                     (errcode(ERRCODE_INVALID_TRANSACTION_STATE),
    1118             :                      errmsg("cannot start commands during a parallel operation")));
    1119             : 
    1120     1092618 :         currentCommandId += 1;
    1121     1092618 :         if (currentCommandId == InvalidCommandId)
    1122             :         {
    1123           0 :             currentCommandId -= 1;
    1124           0 :             ereport(ERROR,
    1125             :                     (errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
    1126             :                      errmsg("cannot have more than 2^32-2 commands in a transaction")));
    1127             :         }
    1128     1092618 :         currentCommandIdUsed = false;
    1129             : 
    1130             :         /* Propagate new command ID into static snapshots */
    1131     1092618 :         SnapshotSetCommandId(currentCommandId);
    1132             : 
    1133             :         /*
    1134             :          * Make any catalog changes done by the just-completed command visible
    1135             :          * in the local syscache.  We obviously don't need to do this after a
    1136             :          * read-only command.  (But see hacks in inval.c to make real sure we
    1137             :          * don't think a command that queued inval messages was read-only.)
    1138             :          */
    1139     1092618 :         AtCCI_LocalCache();
    1140             :     }
    1141     2165248 : }
    1142             : 
    1143             : /*
    1144             :  * ForceSyncCommit
    1145             :  *
    1146             :  * Interface routine to allow commands to force a synchronous commit of the
    1147             :  * current top-level transaction.  Currently, two-phase commit does not
    1148             :  * persist and restore this variable.  So long as all callers use
    1149             :  * PreventInTransactionBlock(), that omission has no consequences.
    1150             :  */
    1151             : void
    1152         938 : ForceSyncCommit(void)
    1153             : {
    1154         938 :     forceSyncCommit = true;
    1155         938 : }
    1156             : 
    1157             : 
    1158             : /* ----------------------------------------------------------------
    1159             :  *                      StartTransaction stuff
    1160             :  * ----------------------------------------------------------------
    1161             :  */
    1162             : 
    1163             : /*
    1164             :  *  AtStart_Cache
    1165             :  */
    1166             : static void
    1167      818430 : AtStart_Cache(void)
    1168             : {
    1169      818430 :     AcceptInvalidationMessages();
    1170      818430 : }
    1171             : 
    1172             : /*
    1173             :  *  AtStart_Memory
    1174             :  */
    1175             : static void
    1176      818430 : AtStart_Memory(void)
    1177             : {
    1178      818430 :     TransactionState s = CurrentTransactionState;
    1179             : 
    1180             :     /*
    1181             :      * Remember the memory context that was active prior to transaction start.
    1182             :      */
    1183      818430 :     s->priorContext = CurrentMemoryContext;
    1184             : 
    1185             :     /*
    1186             :      * If this is the first time through, create a private context for
    1187             :      * AbortTransaction to work in.  By reserving some space now, we can
    1188             :      * insulate AbortTransaction from out-of-memory scenarios.  Like
    1189             :      * ErrorContext, we set it up with slow growth rate and a nonzero minimum
    1190             :      * size, so that space will be reserved immediately.
    1191             :      */
    1192      818430 :     if (TransactionAbortContext == NULL)
    1193       34350 :         TransactionAbortContext =
    1194       34350 :             AllocSetContextCreate(TopMemoryContext,
    1195             :                                   "TransactionAbortContext",
    1196             :                                   32 * 1024,
    1197             :                                   32 * 1024,
    1198             :                                   32 * 1024);
    1199             : 
    1200             :     /*
    1201             :      * Likewise, if this is the first time through, create a top-level context
    1202             :      * for transaction-local data.  This context will be reset at transaction
    1203             :      * end, and then re-used in later transactions.
    1204             :      */
    1205      818430 :     if (TopTransactionContext == NULL)
    1206       34350 :         TopTransactionContext =
    1207       34350 :             AllocSetContextCreate(TopMemoryContext,
    1208             :                                   "TopTransactionContext",
    1209             :                                   ALLOCSET_DEFAULT_SIZES);
    1210             : 
    1211             :     /*
    1212             :      * In a top-level transaction, CurTransactionContext is the same as
    1213             :      * TopTransactionContext.
    1214             :      */
    1215      818430 :     CurTransactionContext = TopTransactionContext;
    1216      818430 :     s->curTransactionContext = CurTransactionContext;
    1217             : 
    1218             :     /* Make the CurTransactionContext active. */
    1219      818430 :     MemoryContextSwitchTo(CurTransactionContext);
    1220      818430 : }
    1221             : 
    1222             : /*
    1223             :  *  AtStart_ResourceOwner
    1224             :  */
    1225             : static void
    1226      818430 : AtStart_ResourceOwner(void)
    1227             : {
    1228      818430 :     TransactionState s = CurrentTransactionState;
    1229             : 
    1230             :     /*
    1231             :      * We shouldn't have a transaction resource owner already.
    1232             :      */
    1233             :     Assert(TopTransactionResourceOwner == NULL);
    1234             : 
    1235             :     /*
    1236             :      * Create a toplevel resource owner for the transaction.
    1237             :      */
    1238      818430 :     s->curTransactionOwner = ResourceOwnerCreate(NULL, "TopTransaction");
    1239             : 
    1240      818430 :     TopTransactionResourceOwner = s->curTransactionOwner;
    1241      818430 :     CurTransactionResourceOwner = s->curTransactionOwner;
    1242      818430 :     CurrentResourceOwner = s->curTransactionOwner;
    1243      818430 : }
    1244             : 
    1245             : /* ----------------------------------------------------------------
    1246             :  *                      StartSubTransaction stuff
    1247             :  * ----------------------------------------------------------------
    1248             :  */
    1249             : 
    1250             : /*
    1251             :  * AtSubStart_Memory
    1252             :  */
    1253             : static void
    1254       19942 : AtSubStart_Memory(void)
    1255             : {
    1256       19942 :     TransactionState s = CurrentTransactionState;
    1257             : 
    1258             :     Assert(CurTransactionContext != NULL);
    1259             : 
    1260             :     /*
    1261             :      * Remember the context that was active prior to subtransaction start.
    1262             :      */
    1263       19942 :     s->priorContext = CurrentMemoryContext;
    1264             : 
    1265             :     /*
    1266             :      * Create a CurTransactionContext, which will be used to hold data that
    1267             :      * survives subtransaction commit but disappears on subtransaction abort.
    1268             :      * We make it a child of the immediate parent's CurTransactionContext.
    1269             :      */
    1270       19942 :     CurTransactionContext = AllocSetContextCreate(CurTransactionContext,
    1271             :                                                   "CurTransactionContext",
    1272             :                                                   ALLOCSET_DEFAULT_SIZES);
    1273       19942 :     s->curTransactionContext = CurTransactionContext;
    1274             : 
    1275             :     /* Make the CurTransactionContext active. */
    1276       19942 :     MemoryContextSwitchTo(CurTransactionContext);
    1277       19942 : }
    1278             : 
    1279             : /*
    1280             :  * AtSubStart_ResourceOwner
    1281             :  */
    1282             : static void
    1283       19942 : AtSubStart_ResourceOwner(void)
    1284             : {
    1285       19942 :     TransactionState s = CurrentTransactionState;
    1286             : 
    1287             :     Assert(s->parent != NULL);
    1288             : 
    1289             :     /*
    1290             :      * Create a resource owner for the subtransaction.  We make it a child of
    1291             :      * the immediate parent's resource owner.
    1292             :      */
    1293       19942 :     s->curTransactionOwner =
    1294       19942 :         ResourceOwnerCreate(s->parent->curTransactionOwner,
    1295             :                             "SubTransaction");
    1296             : 
    1297       19942 :     CurTransactionResourceOwner = s->curTransactionOwner;
    1298       19942 :     CurrentResourceOwner = s->curTransactionOwner;
    1299       19942 : }
    1300             : 
    1301             : /* ----------------------------------------------------------------
    1302             :  *                      CommitTransaction stuff
    1303             :  * ----------------------------------------------------------------
    1304             :  */
    1305             : 
    1306             : /*
    1307             :  *  RecordTransactionCommit
    1308             :  *
    1309             :  * Returns latest XID among xact and its children, or InvalidTransactionId
    1310             :  * if the xact has no XID.  (We compute that here just because it's easier.)
    1311             :  *
    1312             :  * If you change this function, see RecordTransactionCommitPrepared also.
    1313             :  */
    1314             : static TransactionId
    1315      766742 : RecordTransactionCommit(void)
    1316             : {
    1317      766742 :     TransactionId xid = GetTopTransactionIdIfAny();
    1318      766742 :     bool        markXidCommitted = TransactionIdIsValid(xid);
    1319      766742 :     TransactionId latestXid = InvalidTransactionId;
    1320             :     int         nrels;
    1321             :     RelFileLocator *rels;
    1322             :     int         nchildren;
    1323             :     TransactionId *children;
    1324      766742 :     int         ndroppedstats = 0;
    1325      766742 :     xl_xact_stats_item *droppedstats = NULL;
    1326      766742 :     int         nmsgs = 0;
    1327      766742 :     SharedInvalidationMessage *invalMessages = NULL;
    1328      766742 :     bool        RelcacheInitFileInval = false;
    1329             :     bool        wrote_xlog;
    1330             : 
    1331             :     /*
    1332             :      * Log pending invalidations for logical decoding of in-progress
    1333             :      * transactions.  Normally for DDLs, we log this at each command end,
    1334             :      * however, for certain cases where we directly update the system table
    1335             :      * without a transaction block, the invalidations are not logged till this
    1336             :      * time.
    1337             :      */
    1338      766742 :     if (XLogLogicalInfoActive())
    1339       23630 :         LogLogicalInvalidations();
    1340             : 
    1341             :     /* Get data needed for commit record */
    1342      766742 :     nrels = smgrGetPendingDeletes(true, &rels);
    1343      766742 :     nchildren = xactGetCommittedChildren(&children);
    1344      766742 :     ndroppedstats = pgstat_get_transactional_drops(true, &droppedstats);
    1345      766742 :     if (XLogStandbyInfoActive())
    1346      379506 :         nmsgs = xactGetCommittedInvalidationMessages(&invalMessages,
    1347             :                                                      &RelcacheInitFileInval);
    1348      766742 :     wrote_xlog = (XactLastRecEnd != 0);
    1349             : 
    1350             :     /*
    1351             :      * If we haven't been assigned an XID yet, we neither can, nor do we want
    1352             :      * to write a COMMIT record.
    1353             :      */
    1354      766742 :     if (!markXidCommitted)
    1355             :     {
    1356             :         /*
    1357             :          * We expect that every RelationDropStorage is followed by a catalog
    1358             :          * update, and hence XID assignment, so we shouldn't get here with any
    1359             :          * pending deletes. Same is true for dropping stats.
    1360             :          *
    1361             :          * Use a real test not just an Assert to check this, since it's a bit
    1362             :          * fragile.
    1363             :          */
    1364      527624 :         if (nrels != 0 || ndroppedstats != 0)
    1365           0 :             elog(ERROR, "cannot commit a transaction that deleted files but has no xid");
    1366             : 
    1367             :         /* Can't have child XIDs either; AssignTransactionId enforces this */
    1368             :         Assert(nchildren == 0);
    1369             : 
    1370             :         /*
    1371             :          * Transactions without an assigned xid can contain invalidation
    1372             :          * messages.  While inplace updates do this, this is not known to be
    1373             :          * necessary; see comment at inplace CacheInvalidateHeapTuple().
    1374             :          * Extensions might still rely on this capability, and standbys may
    1375             :          * need to process those invals.  We can't emit a commit record
    1376             :          * without an xid, and we don't want to force assigning an xid,
    1377             :          * because that'd be problematic for e.g. vacuum.  Hence we emit a
    1378             :          * bespoke record for the invalidations. We don't want to use that in
    1379             :          * case a commit record is emitted, so they happen synchronously with
    1380             :          * commits (besides not wanting to emit more WAL records).
    1381             :          *
    1382             :          * XXX Every known use of this capability is a defect.  Since an XID
    1383             :          * isn't controlling visibility of the change that prompted invals,
    1384             :          * other sessions need the inval even if this transactions aborts.
    1385             :          *
    1386             :          * ON COMMIT DELETE ROWS does a nontransactional index_build(), which
    1387             :          * queues a relcache inval, including in transactions without an xid
    1388             :          * that had read the (empty) table.  Standbys don't need any ON COMMIT
    1389             :          * DELETE ROWS invals, but we've not done the work to withhold them.
    1390             :          */
    1391      527624 :         if (nmsgs != 0)
    1392             :         {
    1393       15808 :             LogStandbyInvalidations(nmsgs, invalMessages,
    1394             :                                     RelcacheInitFileInval);
    1395       15808 :             wrote_xlog = true;  /* not strictly necessary */
    1396             :         }
    1397             : 
    1398             :         /*
    1399             :          * If we didn't create XLOG entries, we're done here; otherwise we
    1400             :          * should trigger flushing those entries the same as a commit record
    1401             :          * would.  This will primarily happen for HOT pruning and the like; we
    1402             :          * want these to be flushed to disk in due time.
    1403             :          */
    1404      527624 :         if (!wrote_xlog)
    1405      459938 :             goto cleanup;
    1406             :     }
    1407             :     else
    1408             :     {
    1409             :         bool        replorigin;
    1410             : 
    1411             :         /*
    1412             :          * Are we using the replication origins feature?  Or, in other words,
    1413             :          * are we replaying remote actions?
    1414             :          */
    1415      241106 :         replorigin = (replorigin_session_origin != InvalidRepOriginId &&
    1416        1988 :                       replorigin_session_origin != DoNotReplicateId);
    1417             : 
    1418             :         /*
    1419             :          * Mark ourselves as within our "commit critical section".  This
    1420             :          * forces any concurrent checkpoint to wait until we've updated
    1421             :          * pg_xact.  Without this, it is possible for the checkpoint to set
    1422             :          * REDO after the XLOG record but fail to flush the pg_xact update to
    1423             :          * disk, leading to loss of the transaction commit if the system
    1424             :          * crashes a little later.
    1425             :          *
    1426             :          * Note: we could, but don't bother to, set this flag in
    1427             :          * RecordTransactionAbort.  That's because loss of a transaction abort
    1428             :          * is noncritical; the presumption would be that it aborted, anyway.
    1429             :          *
    1430             :          * It's safe to change the delayChkptFlags flag of our own backend
    1431             :          * without holding the ProcArrayLock, since we're the only one
    1432             :          * modifying it.  This makes checkpoint's determination of which xacts
    1433             :          * are delaying the checkpoint a bit fuzzy, but it doesn't matter.
    1434             :          */
    1435             :         Assert((MyProc->delayChkptFlags & DELAY_CHKPT_START) == 0);
    1436      239118 :         START_CRIT_SECTION();
    1437      239118 :         MyProc->delayChkptFlags |= DELAY_CHKPT_START;
    1438             : 
    1439             :         /*
    1440             :          * Insert the commit XLOG record.
    1441             :          */
    1442      239118 :         XactLogCommitRecord(GetCurrentTransactionStopTimestamp(),
    1443             :                             nchildren, children, nrels, rels,
    1444             :                             ndroppedstats, droppedstats,
    1445             :                             nmsgs, invalMessages,
    1446             :                             RelcacheInitFileInval,
    1447             :                             MyXactFlags,
    1448             :                             InvalidTransactionId, NULL /* plain commit */ );
    1449             : 
    1450      239118 :         if (replorigin)
    1451             :             /* Move LSNs forward for this replication origin */
    1452        1988 :             replorigin_session_advance(replorigin_session_origin_lsn,
    1453             :                                        XactLastRecEnd);
    1454             : 
    1455             :         /*
    1456             :          * Record commit timestamp.  The value comes from plain commit
    1457             :          * timestamp if there's no replication origin; otherwise, the
    1458             :          * timestamp was already set in replorigin_session_origin_timestamp by
    1459             :          * replication.
    1460             :          *
    1461             :          * We don't need to WAL-log anything here, as the commit record
    1462             :          * written above already contains the data.
    1463             :          */
    1464             : 
    1465      239118 :         if (!replorigin || replorigin_session_origin_timestamp == 0)
    1466      237336 :             replorigin_session_origin_timestamp = GetCurrentTransactionStopTimestamp();
    1467             : 
    1468      239118 :         TransactionTreeSetCommitTsData(xid, nchildren, children,
    1469             :                                        replorigin_session_origin_timestamp,
    1470             :                                        replorigin_session_origin);
    1471             :     }
    1472             : 
    1473             :     /*
    1474             :      * Check if we want to commit asynchronously.  We can allow the XLOG flush
    1475             :      * to happen asynchronously if synchronous_commit=off, or if the current
    1476             :      * transaction has not performed any WAL-logged operation or didn't assign
    1477             :      * an xid.  The transaction can end up not writing any WAL, even if it has
    1478             :      * an xid, if it only wrote to temporary and/or unlogged tables.  It can
    1479             :      * end up having written WAL without an xid if it did HOT pruning.  In
    1480             :      * case of a crash, the loss of such a transaction will be irrelevant;
    1481             :      * temp tables will be lost anyway, unlogged tables will be truncated and
    1482             :      * HOT pruning will be done again later. (Given the foregoing, you might
    1483             :      * think that it would be unnecessary to emit the XLOG record at all in
    1484             :      * this case, but we don't currently try to do that.  It would certainly
    1485             :      * cause problems at least in Hot Standby mode, where the
    1486             :      * KnownAssignedXids machinery requires tracking every XID assignment.  It
    1487             :      * might be OK to skip it only when wal_level < replica, but for now we
    1488             :      * don't.)
    1489             :      *
    1490             :      * However, if we're doing cleanup of any non-temp rels or committing any
    1491             :      * command that wanted to force sync commit, then we must flush XLOG
    1492             :      * immediately.  (We must not allow asynchronous commit if there are any
    1493             :      * non-temp tables to be deleted, because we might delete the files before
    1494             :      * the COMMIT record is flushed to disk.  We do allow asynchronous commit
    1495             :      * if all to-be-deleted tables are temporary though, since they are lost
    1496             :      * anyway if we crash.)
    1497             :      */
    1498      306804 :     if ((wrote_xlog && markXidCommitted &&
    1499      306804 :          synchronous_commit > SYNCHRONOUS_COMMIT_OFF) ||
    1500       79912 :         forceSyncCommit || nrels > 0)
    1501             :     {
    1502      226932 :         XLogFlush(XactLastRecEnd);
    1503             : 
    1504             :         /*
    1505             :          * Now we may update the CLOG, if we wrote a COMMIT record above
    1506             :          */
    1507      226932 :         if (markXidCommitted)
    1508      226932 :             TransactionIdCommitTree(xid, nchildren, children);
    1509             :     }
    1510             :     else
    1511             :     {
    1512             :         /*
    1513             :          * Asynchronous commit case:
    1514             :          *
    1515             :          * This enables possible committed transaction loss in the case of a
    1516             :          * postmaster crash because WAL buffers are left unwritten. Ideally we
    1517             :          * could issue the WAL write without the fsync, but some
    1518             :          * wal_sync_methods do not allow separate write/fsync.
    1519             :          *
    1520             :          * Report the latest async commit LSN, so that the WAL writer knows to
    1521             :          * flush this commit.
    1522             :          */
    1523       79872 :         XLogSetAsyncXactLSN(XactLastRecEnd);
    1524             : 
    1525             :         /*
    1526             :          * We must not immediately update the CLOG, since we didn't flush the
    1527             :          * XLOG. Instead, we store the LSN up to which the XLOG must be
    1528             :          * flushed before the CLOG may be updated.
    1529             :          */
    1530       79872 :         if (markXidCommitted)
    1531       12186 :             TransactionIdAsyncCommitTree(xid, nchildren, children, XactLastRecEnd);
    1532             :     }
    1533             : 
    1534             :     /*
    1535             :      * If we entered a commit critical section, leave it now, and let
    1536             :      * checkpoints proceed.
    1537             :      */
    1538      306804 :     if (markXidCommitted)
    1539             :     {
    1540      239118 :         MyProc->delayChkptFlags &= ~DELAY_CHKPT_START;
    1541      239118 :         END_CRIT_SECTION();
    1542             :     }
    1543             : 
    1544             :     /* Compute latestXid while we have the child XIDs handy */
    1545      306804 :     latestXid = TransactionIdLatest(xid, nchildren, children);
    1546             : 
    1547             :     /*
    1548             :      * Wait for synchronous replication, if required. Similar to the decision
    1549             :      * above about using committing asynchronously we only want to wait if
    1550             :      * this backend assigned an xid and wrote WAL.  No need to wait if an xid
    1551             :      * was assigned due to temporary/unlogged tables or due to HOT pruning.
    1552             :      *
    1553             :      * Note that at this stage we have marked clog, but still show as running
    1554             :      * in the procarray and continue to hold locks.
    1555             :      */
    1556      306804 :     if (wrote_xlog && markXidCommitted)
    1557      231194 :         SyncRepWaitForLSN(XactLastRecEnd, true);
    1558             : 
    1559             :     /* remember end of last commit record */
    1560      306804 :     XactLastCommitEnd = XactLastRecEnd;
    1561             : 
    1562             :     /* Reset XactLastRecEnd until the next transaction writes something */
    1563      306804 :     XactLastRecEnd = 0;
    1564      766742 : cleanup:
    1565             :     /* Clean up local data */
    1566      766742 :     if (rels)
    1567       18202 :         pfree(rels);
    1568      766742 :     if (ndroppedstats)
    1569       21014 :         pfree(droppedstats);
    1570             : 
    1571      766742 :     return latestXid;
    1572             : }
    1573             : 
    1574             : 
    1575             : /*
    1576             :  *  AtCCI_LocalCache
    1577             :  */
    1578             : static void
    1579     1092618 : AtCCI_LocalCache(void)
    1580             : {
    1581             :     /*
    1582             :      * Make any pending relation map changes visible.  We must do this before
    1583             :      * processing local sinval messages, so that the map changes will get
    1584             :      * reflected into the relcache when relcache invals are processed.
    1585             :      */
    1586     1092618 :     AtCCI_RelationMap();
    1587             : 
    1588             :     /*
    1589             :      * Make catalog changes visible to me for the next command.
    1590             :      */
    1591     1092618 :     CommandEndInvalidationMessages();
    1592     1092612 : }
    1593             : 
    1594             : /*
    1595             :  *  AtCommit_Memory
    1596             :  */
    1597             : static void
    1598      770086 : AtCommit_Memory(void)
    1599             : {
    1600      770086 :     TransactionState s = CurrentTransactionState;
    1601             : 
    1602             :     /*
    1603             :      * Return to the memory context that was current before we started the
    1604             :      * transaction.  (In principle, this could not be any of the contexts we
    1605             :      * are about to delete.  If it somehow is, assertions in mcxt.c will
    1606             :      * complain.)
    1607             :      */
    1608      770086 :     MemoryContextSwitchTo(s->priorContext);
    1609             : 
    1610             :     /*
    1611             :      * Release all transaction-local memory.  TopTransactionContext survives
    1612             :      * but becomes empty; any sub-contexts go away.
    1613             :      */
    1614             :     Assert(TopTransactionContext != NULL);
    1615      770086 :     MemoryContextReset(TopTransactionContext);
    1616             : 
    1617             :     /*
    1618             :      * Clear these pointers as a pro-forma matter.  (Notionally, while
    1619             :      * TopTransactionContext still exists, it's currently not associated with
    1620             :      * this TransactionState struct.)
    1621             :      */
    1622      770086 :     CurTransactionContext = NULL;
    1623      770086 :     s->curTransactionContext = NULL;
    1624      770086 : }
    1625             : 
    1626             : /* ----------------------------------------------------------------
    1627             :  *                      CommitSubTransaction stuff
    1628             :  * ----------------------------------------------------------------
    1629             :  */
    1630             : 
    1631             : /*
    1632             :  * AtSubCommit_Memory
    1633             :  */
    1634             : static void
    1635       10650 : AtSubCommit_Memory(void)
    1636             : {
    1637       10650 :     TransactionState s = CurrentTransactionState;
    1638             : 
    1639             :     Assert(s->parent != NULL);
    1640             : 
    1641             :     /* Return to parent transaction level's memory context. */
    1642       10650 :     CurTransactionContext = s->parent->curTransactionContext;
    1643       10650 :     MemoryContextSwitchTo(CurTransactionContext);
    1644             : 
    1645             :     /*
    1646             :      * Ordinarily we cannot throw away the child's CurTransactionContext,
    1647             :      * since the data it contains will be needed at upper commit.  However, if
    1648             :      * there isn't actually anything in it, we can throw it away.  This avoids
    1649             :      * a small memory leak in the common case of "trivial" subxacts.
    1650             :      */
    1651       10650 :     if (MemoryContextIsEmpty(s->curTransactionContext))
    1652             :     {
    1653       10632 :         MemoryContextDelete(s->curTransactionContext);
    1654       10632 :         s->curTransactionContext = NULL;
    1655             :     }
    1656       10650 : }
    1657             : 
    1658             : /*
    1659             :  * AtSubCommit_childXids
    1660             :  *
    1661             :  * Pass my own XID and my child XIDs up to my parent as committed children.
    1662             :  */
    1663             : static void
    1664        7334 : AtSubCommit_childXids(void)
    1665             : {
    1666        7334 :     TransactionState s = CurrentTransactionState;
    1667             :     int         new_nChildXids;
    1668             : 
    1669             :     Assert(s->parent != NULL);
    1670             : 
    1671             :     /*
    1672             :      * The parent childXids array will need to hold my XID and all my
    1673             :      * childXids, in addition to the XIDs already there.
    1674             :      */
    1675        7334 :     new_nChildXids = s->parent->nChildXids + s->nChildXids + 1;
    1676             : 
    1677             :     /* Allocate or enlarge the parent array if necessary */
    1678        7334 :     if (s->parent->maxChildXids < new_nChildXids)
    1679             :     {
    1680             :         int         new_maxChildXids;
    1681             :         TransactionId *new_childXids;
    1682             : 
    1683             :         /*
    1684             :          * Make it 2x what's needed right now, to avoid having to enlarge it
    1685             :          * repeatedly. But we can't go above MaxAllocSize.  (The latter limit
    1686             :          * is what ensures that we don't need to worry about integer overflow
    1687             :          * here or in the calculation of new_nChildXids.)
    1688             :          */
    1689        3266 :         new_maxChildXids = Min(new_nChildXids * 2,
    1690             :                                (int) (MaxAllocSize / sizeof(TransactionId)));
    1691             : 
    1692        3266 :         if (new_maxChildXids < new_nChildXids)
    1693           0 :             ereport(ERROR,
    1694             :                     (errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
    1695             :                      errmsg("maximum number of committed subtransactions (%d) exceeded",
    1696             :                             (int) (MaxAllocSize / sizeof(TransactionId)))));
    1697             : 
    1698             :         /*
    1699             :          * We keep the child-XID arrays in TopTransactionContext; this avoids
    1700             :          * setting up child-transaction contexts for what might be just a few
    1701             :          * bytes of grandchild XIDs.
    1702             :          */
    1703        3266 :         if (s->parent->childXids == NULL)
    1704             :             new_childXids =
    1705        3182 :                 MemoryContextAlloc(TopTransactionContext,
    1706             :                                    new_maxChildXids * sizeof(TransactionId));
    1707             :         else
    1708          84 :             new_childXids = repalloc(s->parent->childXids,
    1709             :                                      new_maxChildXids * sizeof(TransactionId));
    1710             : 
    1711        3266 :         s->parent->childXids = new_childXids;
    1712        3266 :         s->parent->maxChildXids = new_maxChildXids;
    1713             :     }
    1714             : 
    1715             :     /*
    1716             :      * Copy all my XIDs to parent's array.
    1717             :      *
    1718             :      * Note: We rely on the fact that the XID of a child always follows that
    1719             :      * of its parent.  By copying the XID of this subtransaction before the
    1720             :      * XIDs of its children, we ensure that the array stays ordered. Likewise,
    1721             :      * all XIDs already in the array belong to subtransactions started and
    1722             :      * subcommitted before us, so their XIDs must precede ours.
    1723             :      */
    1724        7334 :     s->parent->childXids[s->parent->nChildXids] = XidFromFullTransactionId(s->fullTransactionId);
    1725             : 
    1726        7334 :     if (s->nChildXids > 0)
    1727        2016 :         memcpy(&s->parent->childXids[s->parent->nChildXids + 1],
    1728        2016 :                s->childXids,
    1729        2016 :                s->nChildXids * sizeof(TransactionId));
    1730             : 
    1731        7334 :     s->parent->nChildXids = new_nChildXids;
    1732             : 
    1733             :     /* Release child's array to avoid leakage */
    1734        7334 :     if (s->childXids != NULL)
    1735        2016 :         pfree(s->childXids);
    1736             :     /* We must reset these to avoid double-free if fail later in commit */
    1737        7334 :     s->childXids = NULL;
    1738        7334 :     s->nChildXids = 0;
    1739        7334 :     s->maxChildXids = 0;
    1740        7334 : }
    1741             : 
    1742             : /* ----------------------------------------------------------------
    1743             :  *                      AbortTransaction stuff
    1744             :  * ----------------------------------------------------------------
    1745             :  */
    1746             : 
    1747             : /*
    1748             :  *  RecordTransactionAbort
    1749             :  *
    1750             :  * Returns latest XID among xact and its children, or InvalidTransactionId
    1751             :  * if the xact has no XID.  (We compute that here just because it's easier.)
    1752             :  */
    1753             : static TransactionId
    1754       57624 : RecordTransactionAbort(bool isSubXact)
    1755             : {
    1756       57624 :     TransactionId xid = GetCurrentTransactionIdIfAny();
    1757             :     TransactionId latestXid;
    1758             :     int         nrels;
    1759             :     RelFileLocator *rels;
    1760       57624 :     int         ndroppedstats = 0;
    1761       57624 :     xl_xact_stats_item *droppedstats = NULL;
    1762             :     int         nchildren;
    1763             :     TransactionId *children;
    1764             :     TimestampTz xact_time;
    1765             :     bool        replorigin;
    1766             : 
    1767             :     /*
    1768             :      * If we haven't been assigned an XID, nobody will care whether we aborted
    1769             :      * or not.  Hence, we're done in that case.  It does not matter if we have
    1770             :      * rels to delete (note that this routine is not responsible for actually
    1771             :      * deleting 'em).  We cannot have any child XIDs, either.
    1772             :      */
    1773       57624 :     if (!TransactionIdIsValid(xid))
    1774             :     {
    1775             :         /* Reset XactLastRecEnd until the next transaction writes something */
    1776       46084 :         if (!isSubXact)
    1777       38090 :             XactLastRecEnd = 0;
    1778       46084 :         return InvalidTransactionId;
    1779             :     }
    1780             : 
    1781             :     /*
    1782             :      * We have a valid XID, so we should write an ABORT record for it.
    1783             :      *
    1784             :      * We do not flush XLOG to disk here, since the default assumption after a
    1785             :      * crash would be that we aborted, anyway.  For the same reason, we don't
    1786             :      * need to worry about interlocking against checkpoint start.
    1787             :      */
    1788             : 
    1789             :     /*
    1790             :      * Check that we haven't aborted halfway through RecordTransactionCommit.
    1791             :      */
    1792       11540 :     if (TransactionIdDidCommit(xid))
    1793           0 :         elog(PANIC, "cannot abort transaction %u, it was already committed",
    1794             :              xid);
    1795             : 
    1796             :     /*
    1797             :      * Are we using the replication origins feature?  Or, in other words, are
    1798             :      * we replaying remote actions?
    1799             :      */
    1800       11590 :     replorigin = (replorigin_session_origin != InvalidRepOriginId &&
    1801          50 :                   replorigin_session_origin != DoNotReplicateId);
    1802             : 
    1803             :     /* Fetch the data we need for the abort record */
    1804       11540 :     nrels = smgrGetPendingDeletes(false, &rels);
    1805       11540 :     nchildren = xactGetCommittedChildren(&children);
    1806       11540 :     ndroppedstats = pgstat_get_transactional_drops(false, &droppedstats);
    1807             : 
    1808             :     /* XXX do we really need a critical section here? */
    1809       11540 :     START_CRIT_SECTION();
    1810             : 
    1811             :     /* Write the ABORT record */
    1812       11540 :     if (isSubXact)
    1813        1298 :         xact_time = GetCurrentTimestamp();
    1814             :     else
    1815             :     {
    1816       10242 :         xact_time = GetCurrentTransactionStopTimestamp();
    1817             :     }
    1818             : 
    1819       11540 :     XactLogAbortRecord(xact_time,
    1820             :                        nchildren, children,
    1821             :                        nrels, rels,
    1822             :                        ndroppedstats, droppedstats,
    1823             :                        MyXactFlags, InvalidTransactionId,
    1824             :                        NULL);
    1825             : 
    1826       11540 :     if (replorigin)
    1827             :         /* Move LSNs forward for this replication origin */
    1828          50 :         replorigin_session_advance(replorigin_session_origin_lsn,
    1829             :                                    XactLastRecEnd);
    1830             : 
    1831             :     /*
    1832             :      * Report the latest async abort LSN, so that the WAL writer knows to
    1833             :      * flush this abort. There's nothing to be gained by delaying this, since
    1834             :      * WALWriter may as well do this when it can. This is important with
    1835             :      * streaming replication because if we don't flush WAL regularly we will
    1836             :      * find that large aborts leave us with a long backlog for when commits
    1837             :      * occur after the abort, increasing our window of data loss should
    1838             :      * problems occur at that point.
    1839             :      */
    1840       11540 :     if (!isSubXact)
    1841       10242 :         XLogSetAsyncXactLSN(XactLastRecEnd);
    1842             : 
    1843             :     /*
    1844             :      * Mark the transaction aborted in clog.  This is not absolutely necessary
    1845             :      * but we may as well do it while we are here; also, in the subxact case
    1846             :      * it is helpful because XactLockTableWait makes use of it to avoid
    1847             :      * waiting for already-aborted subtransactions.  It is OK to do it without
    1848             :      * having flushed the ABORT record to disk, because in event of a crash
    1849             :      * we'd be assumed to have aborted anyway.
    1850             :      */
    1851       11540 :     TransactionIdAbortTree(xid, nchildren, children);
    1852             : 
    1853       11540 :     END_CRIT_SECTION();
    1854             : 
    1855             :     /* Compute latestXid while we have the child XIDs handy */
    1856       11540 :     latestXid = TransactionIdLatest(xid, nchildren, children);
    1857             : 
    1858             :     /*
    1859             :      * If we're aborting a subtransaction, we can immediately remove failed
    1860             :      * XIDs from PGPROC's cache of running child XIDs.  We do that here for
    1861             :      * subxacts, because we already have the child XID array at hand.  For
    1862             :      * main xacts, the equivalent happens just after this function returns.
    1863             :      */
    1864       11540 :     if (isSubXact)
    1865        1298 :         XidCacheRemoveRunningXids(xid, nchildren, children, latestXid);
    1866             : 
    1867             :     /* Reset XactLastRecEnd until the next transaction writes something */
    1868       11540 :     if (!isSubXact)
    1869       10242 :         XactLastRecEnd = 0;
    1870             : 
    1871             :     /* And clean up local data */
    1872       11540 :     if (rels)
    1873        1936 :         pfree(rels);
    1874       11540 :     if (ndroppedstats)
    1875        2652 :         pfree(droppedstats);
    1876             : 
    1877       11540 :     return latestXid;
    1878             : }
    1879             : 
    1880             : /*
    1881             :  *  AtAbort_Memory
    1882             :  */
    1883             : static void
    1884       83410 : AtAbort_Memory(void)
    1885             : {
    1886             :     /*
    1887             :      * Switch into TransactionAbortContext, which should have some free space
    1888             :      * even if nothing else does.  We'll work in this context until we've
    1889             :      * finished cleaning up.
    1890             :      *
    1891             :      * It is barely possible to get here when we've not been able to create
    1892             :      * TransactionAbortContext yet; if so use TopMemoryContext.
    1893             :      */
    1894       83410 :     if (TransactionAbortContext != NULL)
    1895       83410 :         MemoryContextSwitchTo(TransactionAbortContext);
    1896             :     else
    1897           0 :         MemoryContextSwitchTo(TopMemoryContext);
    1898       83410 : }
    1899             : 
    1900             : /*
    1901             :  * AtSubAbort_Memory
    1902             :  */
    1903             : static void
    1904        9292 : AtSubAbort_Memory(void)
    1905             : {
    1906             :     Assert(TransactionAbortContext != NULL);
    1907             : 
    1908        9292 :     MemoryContextSwitchTo(TransactionAbortContext);
    1909        9292 : }
    1910             : 
    1911             : 
    1912             : /*
    1913             :  *  AtAbort_ResourceOwner
    1914             :  */
    1915             : static void
    1916       48344 : AtAbort_ResourceOwner(void)
    1917             : {
    1918             :     /*
    1919             :      * Make sure we have a valid ResourceOwner, if possible (else it will be
    1920             :      * NULL, which is OK)
    1921             :      */
    1922       48344 :     CurrentResourceOwner = TopTransactionResourceOwner;
    1923       48344 : }
    1924             : 
    1925             : /*
    1926             :  * AtSubAbort_ResourceOwner
    1927             :  */
    1928             : static void
    1929        9292 : AtSubAbort_ResourceOwner(void)
    1930             : {
    1931        9292 :     TransactionState s = CurrentTransactionState;
    1932             : 
    1933             :     /* Make sure we have a valid ResourceOwner */
    1934        9292 :     CurrentResourceOwner = s->curTransactionOwner;
    1935        9292 : }
    1936             : 
    1937             : 
    1938             : /*
    1939             :  * AtSubAbort_childXids
    1940             :  */
    1941             : static void
    1942        1298 : AtSubAbort_childXids(void)
    1943             : {
    1944        1298 :     TransactionState s = CurrentTransactionState;
    1945             : 
    1946             :     /*
    1947             :      * We keep the child-XID arrays in TopTransactionContext (see
    1948             :      * AtSubCommit_childXids).  This means we'd better free the array
    1949             :      * explicitly at abort to avoid leakage.
    1950             :      */
    1951        1298 :     if (s->childXids != NULL)
    1952          50 :         pfree(s->childXids);
    1953        1298 :     s->childXids = NULL;
    1954        1298 :     s->nChildXids = 0;
    1955        1298 :     s->maxChildXids = 0;
    1956             : 
    1957             :     /*
    1958             :      * We could prune the unreportedXids array here. But we don't bother. That
    1959             :      * would potentially reduce number of XLOG_XACT_ASSIGNMENT records but it
    1960             :      * would likely introduce more CPU time into the more common paths, so we
    1961             :      * choose not to do that.
    1962             :      */
    1963        1298 : }
    1964             : 
    1965             : /* ----------------------------------------------------------------
    1966             :  *                      CleanupTransaction stuff
    1967             :  * ----------------------------------------------------------------
    1968             :  */
    1969             : 
    1970             : /*
    1971             :  *  AtCleanup_Memory
    1972             :  */
    1973             : static void
    1974       48344 : AtCleanup_Memory(void)
    1975             : {
    1976       48344 :     TransactionState s = CurrentTransactionState;
    1977             : 
    1978             :     /* Should be at top level */
    1979             :     Assert(s->parent == NULL);
    1980             : 
    1981             :     /*
    1982             :      * Return to the memory context that was current before we started the
    1983             :      * transaction.  (In principle, this could not be any of the contexts we
    1984             :      * are about to delete.  If it somehow is, assertions in mcxt.c will
    1985             :      * complain.)
    1986             :      */
    1987       48344 :     MemoryContextSwitchTo(s->priorContext);
    1988             : 
    1989             :     /*
    1990             :      * Clear the special abort context for next time.
    1991             :      */
    1992       48344 :     if (TransactionAbortContext != NULL)
    1993       48344 :         MemoryContextReset(TransactionAbortContext);
    1994             : 
    1995             :     /*
    1996             :      * Release all transaction-local memory, the same as in AtCommit_Memory,
    1997             :      * except we must cope with the possibility that we didn't get as far as
    1998             :      * creating TopTransactionContext.
    1999             :      */
    2000       48344 :     if (TopTransactionContext != NULL)
    2001       48344 :         MemoryContextReset(TopTransactionContext);
    2002             : 
    2003             :     /*
    2004             :      * Clear these pointers as a pro-forma matter.  (Notionally, while
    2005             :      * TopTransactionContext still exists, it's currently not associated with
    2006             :      * this TransactionState struct.)
    2007             :      */
    2008       48344 :     CurTransactionContext = NULL;
    2009       48344 :     s->curTransactionContext = NULL;
    2010       48344 : }
    2011             : 
    2012             : 
    2013             : /* ----------------------------------------------------------------
    2014             :  *                      CleanupSubTransaction stuff
    2015             :  * ----------------------------------------------------------------
    2016             :  */
    2017             : 
    2018             : /*
    2019             :  * AtSubCleanup_Memory
    2020             :  */
    2021             : static void
    2022        9292 : AtSubCleanup_Memory(void)
    2023             : {
    2024        9292 :     TransactionState s = CurrentTransactionState;
    2025             : 
    2026             :     Assert(s->parent != NULL);
    2027             : 
    2028             :     /*
    2029             :      * Return to the memory context that was current before we started the
    2030             :      * subtransaction.  (In principle, this could not be any of the contexts
    2031             :      * we are about to delete.  If it somehow is, assertions in mcxt.c will
    2032             :      * complain.)
    2033             :      */
    2034        9292 :     MemoryContextSwitchTo(s->priorContext);
    2035             : 
    2036             :     /* Update CurTransactionContext (might not be same as priorContext) */
    2037        9292 :     CurTransactionContext = s->parent->curTransactionContext;
    2038             : 
    2039             :     /*
    2040             :      * Clear the special abort context for next time.
    2041             :      */
    2042        9292 :     if (TransactionAbortContext != NULL)
    2043        9292 :         MemoryContextReset(TransactionAbortContext);
    2044             : 
    2045             :     /*
    2046             :      * Delete the subxact local memory contexts. Its CurTransactionContext can
    2047             :      * go too (note this also kills CurTransactionContexts from any children
    2048             :      * of the subxact).
    2049             :      */
    2050        9292 :     if (s->curTransactionContext)
    2051        9292 :         MemoryContextDelete(s->curTransactionContext);
    2052        9292 :     s->curTransactionContext = NULL;
    2053        9292 : }
    2054             : 
    2055             : /* ----------------------------------------------------------------
    2056             :  *                      interface routines
    2057             :  * ----------------------------------------------------------------
    2058             :  */
    2059             : 
    2060             : /*
    2061             :  *  StartTransaction
    2062             :  */
    2063             : static void
    2064      818430 : StartTransaction(void)
    2065             : {
    2066             :     TransactionState s;
    2067             :     VirtualTransactionId vxid;
    2068             : 
    2069             :     /*
    2070             :      * Let's just make sure the state stack is empty
    2071             :      */
    2072      818430 :     s = &TopTransactionStateData;
    2073      818430 :     CurrentTransactionState = s;
    2074             : 
    2075             :     Assert(!FullTransactionIdIsValid(XactTopFullTransactionId));
    2076             : 
    2077             :     /* check the current transaction state */
    2078             :     Assert(s->state == TRANS_DEFAULT);
    2079             : 
    2080             :     /*
    2081             :      * Set the current transaction state information appropriately during
    2082             :      * start processing.  Note that once the transaction status is switched
    2083             :      * this process cannot fail until the user ID and the security context
    2084             :      * flags are fetched below.
    2085             :      */
    2086      818430 :     s->state = TRANS_START;
    2087      818430 :     s->fullTransactionId = InvalidFullTransactionId; /* until assigned */
    2088             : 
    2089             :     /* Determine if statements are logged in this transaction */
    2090      818430 :     xact_is_sampled = log_xact_sample_rate != 0 &&
    2091           0 :         (log_xact_sample_rate == 1 ||
    2092           0 :          pg_prng_double(&pg_global_prng_state) <= log_xact_sample_rate);
    2093             : 
    2094             :     /*
    2095             :      * initialize current transaction state fields
    2096             :      *
    2097             :      * note: prevXactReadOnly is not used at the outermost level
    2098             :      */
    2099      818430 :     s->nestingLevel = 1;
    2100      818430 :     s->gucNestLevel = 1;
    2101      818430 :     s->childXids = NULL;
    2102      818430 :     s->nChildXids = 0;
    2103      818430 :     s->maxChildXids = 0;
    2104             : 
    2105             :     /*
    2106             :      * Once the current user ID and the security context flags are fetched,
    2107             :      * both will be properly reset even if transaction startup fails.
    2108             :      */
    2109      818430 :     GetUserIdAndSecContext(&s->prevUser, &s->prevSecContext);
    2110             : 
    2111             :     /* SecurityRestrictionContext should never be set outside a transaction */
    2112             :     Assert(s->prevSecContext == 0);
    2113             : 
    2114             :     /*
    2115             :      * Make sure we've reset xact state variables
    2116             :      *
    2117             :      * If recovery is still in progress, mark this transaction as read-only.
    2118             :      * We have lower level defences in XLogInsert and elsewhere to stop us
    2119             :      * from modifying data during recovery, but this gives the normal
    2120             :      * indication to the user that the transaction is read-only.
    2121             :      */
    2122      818430 :     if (RecoveryInProgress())
    2123             :     {
    2124        3080 :         s->startedInRecovery = true;
    2125        3080 :         XactReadOnly = true;
    2126             :     }
    2127             :     else
    2128             :     {
    2129      815350 :         s->startedInRecovery = false;
    2130      815350 :         XactReadOnly = DefaultXactReadOnly;
    2131             :     }
    2132      818430 :     XactDeferrable = DefaultXactDeferrable;
    2133      818430 :     XactIsoLevel = DefaultXactIsoLevel;
    2134      818430 :     forceSyncCommit = false;
    2135      818430 :     MyXactFlags = 0;
    2136             : 
    2137             :     /*
    2138             :      * reinitialize within-transaction counters
    2139             :      */
    2140      818430 :     s->subTransactionId = TopSubTransactionId;
    2141      818430 :     currentSubTransactionId = TopSubTransactionId;
    2142      818430 :     currentCommandId = FirstCommandId;
    2143      818430 :     currentCommandIdUsed = false;
    2144             : 
    2145             :     /*
    2146             :      * initialize reported xid accounting
    2147             :      */
    2148      818430 :     nUnreportedXids = 0;
    2149      818430 :     s->didLogXid = false;
    2150             : 
    2151             :     /*
    2152             :      * must initialize resource-management stuff first
    2153             :      */
    2154      818430 :     AtStart_Memory();
    2155      818430 :     AtStart_ResourceOwner();
    2156             : 
    2157             :     /*
    2158             :      * Assign a new LocalTransactionId, and combine it with the proc number to
    2159             :      * form a virtual transaction id.
    2160             :      */
    2161      818430 :     vxid.procNumber = MyProcNumber;
    2162      818430 :     vxid.localTransactionId = GetNextLocalTransactionId();
    2163             : 
    2164             :     /*
    2165             :      * Lock the virtual transaction id before we announce it in the proc array
    2166             :      */
    2167      818430 :     VirtualXactLockTableInsert(vxid);
    2168             : 
    2169             :     /*
    2170             :      * Advertise it in the proc array.  We assume assignment of
    2171             :      * localTransactionId is atomic, and the proc number should be set
    2172             :      * already.
    2173             :      */
    2174             :     Assert(MyProc->vxid.procNumber == vxid.procNumber);
    2175      818430 :     MyProc->vxid.lxid = vxid.localTransactionId;
    2176             : 
    2177             :     TRACE_POSTGRESQL_TRANSACTION_START(vxid.localTransactionId);
    2178             : 
    2179             :     /*
    2180             :      * set transaction_timestamp() (a/k/a now()).  Normally, we want this to
    2181             :      * be the same as the first command's statement_timestamp(), so don't do a
    2182             :      * fresh GetCurrentTimestamp() call (which'd be expensive anyway).  But
    2183             :      * for transactions started inside procedures (i.e., nonatomic SPI
    2184             :      * contexts), we do need to advance the timestamp.  Also, in a parallel
    2185             :      * worker, the timestamp should already have been provided by a call to
    2186             :      * SetParallelStartTimestamps().
    2187             :      */
    2188      818430 :     if (!IsParallelWorker())
    2189             :     {
    2190      810192 :         if (!SPI_inside_nonatomic_context())
    2191      805766 :             xactStartTimestamp = stmtStartTimestamp;
    2192             :         else
    2193        4426 :             xactStartTimestamp = GetCurrentTimestamp();
    2194             :     }
    2195             :     else
    2196             :         Assert(xactStartTimestamp != 0);
    2197      818430 :     pgstat_report_xact_timestamp(xactStartTimestamp);
    2198             :     /* Mark xactStopTimestamp as unset. */
    2199      818430 :     xactStopTimestamp = 0;
    2200             : 
    2201             :     /*
    2202             :      * initialize other subsystems for new transaction
    2203             :      */
    2204      818430 :     AtStart_GUC();
    2205      818430 :     AtStart_Cache();
    2206      818430 :     AfterTriggerBeginXact();
    2207             : 
    2208             :     /*
    2209             :      * done with start processing, set current transaction state to "in
    2210             :      * progress"
    2211             :      */
    2212      818430 :     s->state = TRANS_INPROGRESS;
    2213             : 
    2214             :     /* Schedule transaction timeout */
    2215      818430 :     if (TransactionTimeout > 0)
    2216           2 :         enable_timeout_after(TRANSACTION_TIMEOUT, TransactionTimeout);
    2217             : 
    2218      818430 :     ShowTransactionState("StartTransaction");
    2219      818430 : }
    2220             : 
    2221             : 
    2222             : /*
    2223             :  *  CommitTransaction
    2224             :  *
    2225             :  * NB: if you change this routine, better look at PrepareTransaction too!
    2226             :  */
    2227             : static void
    2228      769946 : CommitTransaction(void)
    2229             : {
    2230      769946 :     TransactionState s = CurrentTransactionState;
    2231             :     TransactionId latestXid;
    2232             :     bool        is_parallel_worker;
    2233             : 
    2234      769946 :     is_parallel_worker = (s->blockState == TBLOCK_PARALLEL_INPROGRESS);
    2235             : 
    2236             :     /* Enforce parallel mode restrictions during parallel worker commit. */
    2237      769946 :     if (is_parallel_worker)
    2238        2734 :         EnterParallelMode();
    2239             : 
    2240      769946 :     ShowTransactionState("CommitTransaction");
    2241             : 
    2242             :     /*
    2243             :      * check the current transaction state
    2244             :      */
    2245      769946 :     if (s->state != TRANS_INPROGRESS)
    2246           0 :         elog(WARNING, "CommitTransaction while in %s state",
    2247             :              TransStateAsString(s->state));
    2248             :     Assert(s->parent == NULL);
    2249             : 
    2250             :     /*
    2251             :      * Do pre-commit processing that involves calling user-defined code, such
    2252             :      * as triggers.  SECURITY_RESTRICTED_OPERATION contexts must not queue an
    2253             :      * action that would run here, because that would bypass the sandbox.
    2254             :      * Since closing cursors could queue trigger actions, triggers could open
    2255             :      * cursors, etc, we have to keep looping until there's nothing left to do.
    2256             :      */
    2257             :     for (;;)
    2258             :     {
    2259             :         /*
    2260             :          * Fire all currently pending deferred triggers.
    2261             :          */
    2262      781068 :         AfterTriggerFireDeferred();
    2263             : 
    2264             :         /*
    2265             :          * Close open portals (converting holdable ones into static portals).
    2266             :          * If there weren't any, we are done ... otherwise loop back to check
    2267             :          * if they queued deferred triggers.  Lather, rinse, repeat.
    2268             :          */
    2269      780914 :         if (!PreCommit_Portals(false))
    2270      769792 :             break;
    2271             :     }
    2272             : 
    2273             :     /*
    2274             :      * The remaining actions cannot call any user-defined code, so it's safe
    2275             :      * to start shutting down within-transaction services.  But note that most
    2276             :      * of this stuff could still throw an error, which would switch us into
    2277             :      * the transaction-abort path.
    2278             :      */
    2279             : 
    2280      769792 :     CallXactCallbacks(is_parallel_worker ? XACT_EVENT_PARALLEL_PRE_COMMIT
    2281             :                       : XACT_EVENT_PRE_COMMIT);
    2282             : 
    2283             :     /*
    2284             :      * If this xact has started any unfinished parallel operation, clean up
    2285             :      * its workers, warning about leaked resources.  (But we don't actually
    2286             :      * reset parallelModeLevel till entering TRANS_COMMIT, a bit below.  This
    2287             :      * keeps parallel mode restrictions active as long as possible in a
    2288             :      * parallel worker.)
    2289             :      */
    2290      769792 :     AtEOXact_Parallel(true);
    2291      769792 :     if (is_parallel_worker)
    2292             :     {
    2293        2734 :         if (s->parallelModeLevel != 1)
    2294           0 :             elog(WARNING, "parallelModeLevel is %d not 1 at end of parallel worker transaction",
    2295             :                  s->parallelModeLevel);
    2296             :     }
    2297             :     else
    2298             :     {
    2299      767058 :         if (s->parallelModeLevel != 0)
    2300           0 :             elog(WARNING, "parallelModeLevel is %d not 0 at end of transaction",
    2301             :                  s->parallelModeLevel);
    2302             :     }
    2303             : 
    2304             :     /* Shut down the deferred-trigger manager */
    2305      769792 :     AfterTriggerEndXact(true);
    2306             : 
    2307             :     /*
    2308             :      * Let ON COMMIT management do its thing (must happen after closing
    2309             :      * cursors, to avoid dangling-reference problems)
    2310             :      */
    2311      769792 :     PreCommit_on_commit_actions();
    2312             : 
    2313             :     /*
    2314             :      * Synchronize files that are created and not WAL-logged during this
    2315             :      * transaction. This must happen before AtEOXact_RelationMap(), so that we
    2316             :      * don't see committed-but-broken files after a crash.
    2317             :      */
    2318      769786 :     smgrDoPendingSyncs(true, is_parallel_worker);
    2319             : 
    2320             :     /* close large objects before lower-level cleanup */
    2321      769786 :     AtEOXact_LargeObject(true);
    2322             : 
    2323             :     /*
    2324             :      * Insert notifications sent by NOTIFY commands into the queue.  This
    2325             :      * should be late in the pre-commit sequence to minimize time spent
    2326             :      * holding the notify-insertion lock.  However, this could result in
    2327             :      * creating a snapshot, so we must do it before serializable cleanup.
    2328             :      */
    2329      769786 :     PreCommit_Notify();
    2330             : 
    2331             :     /*
    2332             :      * Mark serializable transaction as complete for predicate locking
    2333             :      * purposes.  This should be done as late as we can put it and still allow
    2334             :      * errors to be raised for failure patterns found at commit.  This is not
    2335             :      * appropriate in a parallel worker however, because we aren't committing
    2336             :      * the leader's transaction and its serializable state will live on.
    2337             :      */
    2338      769786 :     if (!is_parallel_worker)
    2339      767052 :         PreCommit_CheckForSerializationFailure();
    2340             : 
    2341             :     /* Prevent cancel/die interrupt while cleaning up */
    2342      769476 :     HOLD_INTERRUPTS();
    2343             : 
    2344             :     /* Commit updates to the relation map --- do this as late as possible */
    2345      769476 :     AtEOXact_RelationMap(true, is_parallel_worker);
    2346             : 
    2347             :     /*
    2348             :      * set the current transaction state information appropriately during
    2349             :      * commit processing
    2350             :      */
    2351      769476 :     s->state = TRANS_COMMIT;
    2352      769476 :     s->parallelModeLevel = 0;
    2353      769476 :     s->parallelChildXact = false;    /* should be false already */
    2354             : 
    2355             :     /* Disable transaction timeout */
    2356      769476 :     if (TransactionTimeout > 0)
    2357           2 :         disable_timeout(TRANSACTION_TIMEOUT, false);
    2358             : 
    2359      769476 :     if (!is_parallel_worker)
    2360             :     {
    2361             :         /*
    2362             :          * We need to mark our XIDs as committed in pg_xact.  This is where we
    2363             :          * durably commit.
    2364             :          */
    2365      766742 :         latestXid = RecordTransactionCommit();
    2366             :     }
    2367             :     else
    2368             :     {
    2369             :         /*
    2370             :          * We must not mark our XID committed; the parallel leader is
    2371             :          * responsible for that.
    2372             :          */
    2373        2734 :         latestXid = InvalidTransactionId;
    2374             : 
    2375             :         /*
    2376             :          * Make sure the leader will know about any WAL we wrote before it
    2377             :          * commits.
    2378             :          */
    2379        2734 :         ParallelWorkerReportLastRecEnd(XactLastRecEnd);
    2380             :     }
    2381             : 
    2382             :     TRACE_POSTGRESQL_TRANSACTION_COMMIT(MyProc->vxid.lxid);
    2383             : 
    2384             :     /*
    2385             :      * Let others know about no transaction in progress by me. Note that this
    2386             :      * must be done _before_ releasing locks we hold and _after_
    2387             :      * RecordTransactionCommit.
    2388             :      */
    2389      769476 :     ProcArrayEndTransaction(MyProc, latestXid);
    2390             : 
    2391             :     /*
    2392             :      * This is all post-commit cleanup.  Note that if an error is raised here,
    2393             :      * it's too late to abort the transaction.  This should be just
    2394             :      * noncritical resource releasing.
    2395             :      *
    2396             :      * The ordering of operations is not entirely random.  The idea is:
    2397             :      * release resources visible to other backends (eg, files, buffer pins);
    2398             :      * then release locks; then release backend-local resources. We want to
    2399             :      * release locks at the point where any backend waiting for us will see
    2400             :      * our transaction as being fully cleaned up.
    2401             :      *
    2402             :      * Resources that can be associated with individual queries are handled by
    2403             :      * the ResourceOwner mechanism.  The other calls here are for backend-wide
    2404             :      * state.
    2405             :      */
    2406             : 
    2407      769476 :     CallXactCallbacks(is_parallel_worker ? XACT_EVENT_PARALLEL_COMMIT
    2408             :                       : XACT_EVENT_COMMIT);
    2409             : 
    2410      769476 :     CurrentResourceOwner = NULL;
    2411      769476 :     ResourceOwnerRelease(TopTransactionResourceOwner,
    2412             :                          RESOURCE_RELEASE_BEFORE_LOCKS,
    2413             :                          true, true);
    2414             : 
    2415      769476 :     AtEOXact_Aio(true);
    2416             : 
    2417             :     /* Check we've released all buffer pins */
    2418      769476 :     AtEOXact_Buffers(true);
    2419             : 
    2420             :     /* Clean up the relation cache */
    2421      769476 :     AtEOXact_RelationCache(true);
    2422             : 
    2423             :     /* Clean up the type cache */
    2424      769476 :     AtEOXact_TypeCache();
    2425             : 
    2426             :     /*
    2427             :      * Make catalog changes visible to all backends.  This has to happen after
    2428             :      * relcache references are dropped (see comments for
    2429             :      * AtEOXact_RelationCache), but before locks are released (if anyone is
    2430             :      * waiting for lock on a relation we've modified, we want them to know
    2431             :      * about the catalog change before they start using the relation).
    2432             :      */
    2433      769476 :     AtEOXact_Inval(true);
    2434             : 
    2435      769476 :     AtEOXact_MultiXact();
    2436             : 
    2437      769476 :     ResourceOwnerRelease(TopTransactionResourceOwner,
    2438             :                          RESOURCE_RELEASE_LOCKS,
    2439             :                          true, true);
    2440      769476 :     ResourceOwnerRelease(TopTransactionResourceOwner,
    2441             :                          RESOURCE_RELEASE_AFTER_LOCKS,
    2442             :                          true, true);
    2443             : 
    2444             :     /*
    2445             :      * Likewise, dropping of files deleted during the transaction is best done
    2446             :      * after releasing relcache and buffer pins.  (This is not strictly
    2447             :      * necessary during commit, since such pins should have been released
    2448             :      * already, but this ordering is definitely critical during abort.)  Since
    2449             :      * this may take many seconds, also delay until after releasing locks.
    2450             :      * Other backends will observe the attendant catalog changes and not
    2451             :      * attempt to access affected files.
    2452             :      */
    2453      769476 :     smgrDoPendingDeletes(true);
    2454             : 
    2455             :     /*
    2456             :      * Send out notification signals to other backends (and do other
    2457             :      * post-commit NOTIFY cleanup).  This must not happen until after our
    2458             :      * transaction is fully done from the viewpoint of other backends.
    2459             :      */
    2460      769476 :     AtCommit_Notify();
    2461             : 
    2462             :     /*
    2463             :      * Everything after this should be purely internal-to-this-backend
    2464             :      * cleanup.
    2465             :      */
    2466      769476 :     AtEOXact_GUC(true, 1);
    2467      769476 :     AtEOXact_SPI(true);
    2468      769476 :     AtEOXact_Enum();
    2469      769476 :     AtEOXact_on_commit_actions(true);
    2470      769476 :     AtEOXact_Namespace(true, is_parallel_worker);
    2471      769476 :     AtEOXact_SMgr();
    2472      769476 :     AtEOXact_Files(true);
    2473      769476 :     AtEOXact_ComboCid();
    2474      769476 :     AtEOXact_HashTables(true);
    2475      769476 :     AtEOXact_PgStat(true, is_parallel_worker);
    2476      769476 :     AtEOXact_Snapshot(true, false);
    2477      769476 :     AtEOXact_ApplyLauncher(true);
    2478      769476 :     AtEOXact_LogicalRepWorkers(true);
    2479      769476 :     pgstat_report_xact_timestamp(0);
    2480             : 
    2481      769476 :     ResourceOwnerDelete(TopTransactionResourceOwner);
    2482      769476 :     s->curTransactionOwner = NULL;
    2483      769476 :     CurTransactionResourceOwner = NULL;
    2484      769476 :     TopTransactionResourceOwner = NULL;
    2485             : 
    2486      769476 :     AtCommit_Memory();
    2487             : 
    2488      769476 :     s->fullTransactionId = InvalidFullTransactionId;
    2489      769476 :     s->subTransactionId = InvalidSubTransactionId;
    2490      769476 :     s->nestingLevel = 0;
    2491      769476 :     s->gucNestLevel = 0;
    2492      769476 :     s->childXids = NULL;
    2493      769476 :     s->nChildXids = 0;
    2494      769476 :     s->maxChildXids = 0;
    2495             : 
    2496      769476 :     XactTopFullTransactionId = InvalidFullTransactionId;
    2497      769476 :     nParallelCurrentXids = 0;
    2498             : 
    2499             :     /*
    2500             :      * done with commit processing, set current transaction state back to
    2501             :      * default
    2502             :      */
    2503      769476 :     s->state = TRANS_DEFAULT;
    2504             : 
    2505      769476 :     RESUME_INTERRUPTS();
    2506      769476 : }
    2507             : 
    2508             : 
    2509             : /*
    2510             :  *  PrepareTransaction
    2511             :  *
    2512             :  * NB: if you change this routine, better look at CommitTransaction too!
    2513             :  */
    2514             : static void
    2515         708 : PrepareTransaction(void)
    2516             : {
    2517         708 :     TransactionState s = CurrentTransactionState;
    2518         708 :     TransactionId xid = GetCurrentTransactionId();
    2519             :     GlobalTransaction gxact;
    2520             :     TimestampTz prepared_at;
    2521             : 
    2522             :     Assert(!IsInParallelMode());
    2523             : 
    2524         708 :     ShowTransactionState("PrepareTransaction");
    2525             : 
    2526             :     /*
    2527             :      * check the current transaction state
    2528             :      */
    2529         708 :     if (s->state != TRANS_INPROGRESS)
    2530           0 :         elog(WARNING, "PrepareTransaction while in %s state",
    2531             :              TransStateAsString(s->state));
    2532             :     Assert(s->parent == NULL);
    2533             : 
    2534             :     /*
    2535             :      * Do pre-commit processing that involves calling user-defined code, such
    2536             :      * as triggers.  Since closing cursors could queue trigger actions,
    2537             :      * triggers could open cursors, etc, we have to keep looping until there's
    2538             :      * nothing left to do.
    2539             :      */
    2540             :     for (;;)
    2541             :     {
    2542             :         /*
    2543             :          * Fire all currently pending deferred triggers.
    2544             :          */
    2545         714 :         AfterTriggerFireDeferred();
    2546             : 
    2547             :         /*
    2548             :          * Close open portals (converting holdable ones into static portals).
    2549             :          * If there weren't any, we are done ... otherwise loop back to check
    2550             :          * if they queued deferred triggers.  Lather, rinse, repeat.
    2551             :          */
    2552         714 :         if (!PreCommit_Portals(true))
    2553         708 :             break;
    2554             :     }
    2555             : 
    2556         708 :     CallXactCallbacks(XACT_EVENT_PRE_PREPARE);
    2557             : 
    2558             :     /*
    2559             :      * The remaining actions cannot call any user-defined code, so it's safe
    2560             :      * to start shutting down within-transaction services.  But note that most
    2561             :      * of this stuff could still throw an error, which would switch us into
    2562             :      * the transaction-abort path.
    2563             :      */
    2564             : 
    2565             :     /* Shut down the deferred-trigger manager */
    2566         706 :     AfterTriggerEndXact(true);
    2567             : 
    2568             :     /*
    2569             :      * Let ON COMMIT management do its thing (must happen after closing
    2570             :      * cursors, to avoid dangling-reference problems)
    2571             :      */
    2572         706 :     PreCommit_on_commit_actions();
    2573             : 
    2574             :     /*
    2575             :      * Synchronize files that are created and not WAL-logged during this
    2576             :      * transaction. This must happen before EndPrepare(), so that we don't see
    2577             :      * committed-but-broken files after a crash and COMMIT PREPARED.
    2578             :      */
    2579         706 :     smgrDoPendingSyncs(true, false);
    2580             : 
    2581             :     /* close large objects before lower-level cleanup */
    2582         706 :     AtEOXact_LargeObject(true);
    2583             : 
    2584             :     /* NOTIFY requires no work at this point */
    2585             : 
    2586             :     /*
    2587             :      * Mark serializable transaction as complete for predicate locking
    2588             :      * purposes.  This should be done as late as we can put it and still allow
    2589             :      * errors to be raised for failure patterns found at commit.
    2590             :      */
    2591         706 :     PreCommit_CheckForSerializationFailure();
    2592             : 
    2593             :     /*
    2594             :      * Don't allow PREPARE TRANSACTION if we've accessed a temporary table in
    2595             :      * this transaction.  Having the prepared xact hold locks on another
    2596             :      * backend's temp table seems a bad idea --- for instance it would prevent
    2597             :      * the backend from exiting.  There are other problems too, such as how to
    2598             :      * clean up the source backend's local buffers and ON COMMIT state if the
    2599             :      * prepared xact includes a DROP of a temp table.
    2600             :      *
    2601             :      * Other objects types, like functions, operators or extensions, share the
    2602             :      * same restriction as they should not be created, locked or dropped as
    2603             :      * this can mess up with this session or even a follow-up session trying
    2604             :      * to use the same temporary namespace.
    2605             :      *
    2606             :      * We must check this after executing any ON COMMIT actions, because they
    2607             :      * might still access a temp relation.
    2608             :      *
    2609             :      * XXX In principle this could be relaxed to allow some useful special
    2610             :      * cases, such as a temp table created and dropped all within the
    2611             :      * transaction.  That seems to require much more bookkeeping though.
    2612             :      */
    2613         706 :     if ((MyXactFlags & XACT_FLAGS_ACCESSEDTEMPNAMESPACE))
    2614          68 :         ereport(ERROR,
    2615             :                 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
    2616             :                  errmsg("cannot PREPARE a transaction that has operated on temporary objects")));
    2617             : 
    2618             :     /*
    2619             :      * Likewise, don't allow PREPARE after pg_export_snapshot.  This could be
    2620             :      * supported if we added cleanup logic to twophase.c, but for now it
    2621             :      * doesn't seem worth the trouble.
    2622             :      */
    2623         638 :     if (XactHasExportedSnapshots())
    2624           0 :         ereport(ERROR,
    2625             :                 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
    2626             :                  errmsg("cannot PREPARE a transaction that has exported snapshots")));
    2627             : 
    2628             :     /* Prevent cancel/die interrupt while cleaning up */
    2629         638 :     HOLD_INTERRUPTS();
    2630             : 
    2631             :     /*
    2632             :      * set the current transaction state information appropriately during
    2633             :      * prepare processing
    2634             :      */
    2635         638 :     s->state = TRANS_PREPARE;
    2636             : 
    2637             :     /* Disable transaction timeout */
    2638         638 :     if (TransactionTimeout > 0)
    2639           0 :         disable_timeout(TRANSACTION_TIMEOUT, false);
    2640             : 
    2641         638 :     prepared_at = GetCurrentTimestamp();
    2642             : 
    2643             :     /*
    2644             :      * Reserve the GID for this transaction. This could fail if the requested
    2645             :      * GID is invalid or already in use.
    2646             :      */
    2647         638 :     gxact = MarkAsPreparing(xid, prepareGID, prepared_at,
    2648             :                             GetUserId(), MyDatabaseId);
    2649         614 :     prepareGID = NULL;
    2650             : 
    2651             :     /*
    2652             :      * Collect data for the 2PC state file.  Note that in general, no actual
    2653             :      * state change should happen in the called modules during this step,
    2654             :      * since it's still possible to fail before commit, and in that case we
    2655             :      * want transaction abort to be able to clean up.  (In particular, the
    2656             :      * AtPrepare routines may error out if they find cases they cannot
    2657             :      * handle.)  State cleanup should happen in the PostPrepare routines
    2658             :      * below.  However, some modules can go ahead and clear state here because
    2659             :      * they wouldn't do anything with it during abort anyway.
    2660             :      *
    2661             :      * Note: because the 2PC state file records will be replayed in the same
    2662             :      * order they are made, the order of these calls has to match the order in
    2663             :      * which we want things to happen during COMMIT PREPARED or ROLLBACK
    2664             :      * PREPARED; in particular, pay attention to whether things should happen
    2665             :      * before or after releasing the transaction's locks.
    2666             :      */
    2667         614 :     StartPrepare(gxact);
    2668             : 
    2669         614 :     AtPrepare_Notify();
    2670         614 :     AtPrepare_Locks();
    2671         610 :     AtPrepare_PredicateLocks();
    2672         610 :     AtPrepare_PgStat();
    2673         610 :     AtPrepare_MultiXact();
    2674         610 :     AtPrepare_RelationMap();
    2675             : 
    2676             :     /*
    2677             :      * Here is where we really truly prepare.
    2678             :      *
    2679             :      * We have to record transaction prepares even if we didn't make any
    2680             :      * updates, because the transaction manager might get confused if we lose
    2681             :      * a global transaction.
    2682             :      */
    2683         610 :     EndPrepare(gxact);
    2684             : 
    2685             :     /*
    2686             :      * Now we clean up backend-internal state and release internal resources.
    2687             :      */
    2688             : 
    2689             :     /* Reset XactLastRecEnd until the next transaction writes something */
    2690         610 :     XactLastRecEnd = 0;
    2691             : 
    2692             :     /*
    2693             :      * Transfer our locks to a dummy PGPROC.  This has to be done before
    2694             :      * ProcArrayClearTransaction().  Otherwise, a GetLockConflicts() would
    2695             :      * conclude "xact already committed or aborted" for our locks.
    2696             :      */
    2697         610 :     PostPrepare_Locks(xid);
    2698             : 
    2699             :     /*
    2700             :      * Let others know about no transaction in progress by me.  This has to be
    2701             :      * done *after* the prepared transaction has been marked valid, else
    2702             :      * someone may think it is unlocked and recyclable.
    2703             :      */
    2704         610 :     ProcArrayClearTransaction(MyProc);
    2705             : 
    2706             :     /*
    2707             :      * In normal commit-processing, this is all non-critical post-transaction
    2708             :      * cleanup.  When the transaction is prepared, however, it's important
    2709             :      * that the locks and other per-backend resources are transferred to the
    2710             :      * prepared transaction's PGPROC entry.  Note that if an error is raised
    2711             :      * here, it's too late to abort the transaction. XXX: This probably should
    2712             :      * be in a critical section, to force a PANIC if any of this fails, but
    2713             :      * that cure could be worse than the disease.
    2714             :      */
    2715             : 
    2716         610 :     CallXactCallbacks(XACT_EVENT_PREPARE);
    2717             : 
    2718         610 :     ResourceOwnerRelease(TopTransactionResourceOwner,
    2719             :                          RESOURCE_RELEASE_BEFORE_LOCKS,
    2720             :                          true, true);
    2721             : 
    2722         610 :     AtEOXact_Aio(true);
    2723             : 
    2724             :     /* Check we've released all buffer pins */
    2725         610 :     AtEOXact_Buffers(true);
    2726             : 
    2727             :     /* Clean up the relation cache */
    2728         610 :     AtEOXact_RelationCache(true);
    2729             : 
    2730             :     /* Clean up the type cache */
    2731         610 :     AtEOXact_TypeCache();
    2732             : 
    2733             :     /* notify doesn't need a postprepare call */
    2734             : 
    2735         610 :     PostPrepare_PgStat();
    2736             : 
    2737         610 :     PostPrepare_Inval();
    2738             : 
    2739         610 :     PostPrepare_smgr();
    2740             : 
    2741         610 :     PostPrepare_MultiXact(xid);
    2742             : 
    2743         610 :     PostPrepare_PredicateLocks(xid);
    2744             : 
    2745         610 :     ResourceOwnerRelease(TopTransactionResourceOwner,
    2746             :                          RESOURCE_RELEASE_LOCKS,
    2747             :                          true, true);
    2748         610 :     ResourceOwnerRelease(TopTransactionResourceOwner,
    2749             :                          RESOURCE_RELEASE_AFTER_LOCKS,
    2750             :                          true, true);
    2751             : 
    2752             :     /*
    2753             :      * Allow another backend to finish the transaction.  After
    2754             :      * PostPrepare_Twophase(), the transaction is completely detached from our
    2755             :      * backend.  The rest is just non-critical cleanup of backend-local state.
    2756             :      */
    2757         610 :     PostPrepare_Twophase();
    2758             : 
    2759             :     /* PREPARE acts the same as COMMIT as far as GUC is concerned */
    2760         610 :     AtEOXact_GUC(true, 1);
    2761         610 :     AtEOXact_SPI(true);
    2762         610 :     AtEOXact_Enum();
    2763         610 :     AtEOXact_on_commit_actions(true);
    2764         610 :     AtEOXact_Namespace(true, false);
    2765         610 :     AtEOXact_SMgr();
    2766         610 :     AtEOXact_Files(true);
    2767         610 :     AtEOXact_ComboCid();
    2768         610 :     AtEOXact_HashTables(true);
    2769             :     /* don't call AtEOXact_PgStat here; we fixed pgstat state above */
    2770         610 :     AtEOXact_Snapshot(true, true);
    2771             :     /* we treat PREPARE as ROLLBACK so far as waking workers goes */
    2772         610 :     AtEOXact_ApplyLauncher(false);
    2773         610 :     AtEOXact_LogicalRepWorkers(false);
    2774         610 :     pgstat_report_xact_timestamp(0);
    2775             : 
    2776         610 :     CurrentResourceOwner = NULL;
    2777         610 :     ResourceOwnerDelete(TopTransactionResourceOwner);
    2778         610 :     s->curTransactionOwner = NULL;
    2779         610 :     CurTransactionResourceOwner = NULL;
    2780         610 :     TopTransactionResourceOwner = NULL;
    2781             : 
    2782         610 :     AtCommit_Memory();
    2783             : 
    2784         610 :     s->fullTransactionId = InvalidFullTransactionId;
    2785         610 :     s->subTransactionId = InvalidSubTransactionId;
    2786         610 :     s->nestingLevel = 0;
    2787         610 :     s->gucNestLevel = 0;
    2788         610 :     s->childXids = NULL;
    2789         610 :     s->nChildXids = 0;
    2790         610 :     s->maxChildXids = 0;
    2791             : 
    2792         610 :     XactTopFullTransactionId = InvalidFullTransactionId;
    2793         610 :     nParallelCurrentXids = 0;
    2794             : 
    2795             :     /*
    2796             :      * done with 1st phase commit processing, set current transaction state
    2797             :      * back to default
    2798             :      */
    2799         610 :     s->state = TRANS_DEFAULT;
    2800             : 
    2801         610 :     RESUME_INTERRUPTS();
    2802         610 : }
    2803             : 
    2804             : 
    2805             : /*
    2806             :  *  AbortTransaction
    2807             :  */
    2808             : static void
    2809       48344 : AbortTransaction(void)
    2810             : {
    2811       48344 :     TransactionState s = CurrentTransactionState;
    2812             :     TransactionId latestXid;
    2813             :     bool        is_parallel_worker;
    2814             : 
    2815             :     /* Prevent cancel/die interrupt while cleaning up */
    2816       48344 :     HOLD_INTERRUPTS();
    2817             : 
    2818             :     /* Disable transaction timeout */
    2819       48344 :     if (TransactionTimeout > 0)
    2820           2 :         disable_timeout(TRANSACTION_TIMEOUT, false);
    2821             : 
    2822             :     /* Make sure we have a valid memory context and resource owner */
    2823       48344 :     AtAbort_Memory();
    2824       48344 :     AtAbort_ResourceOwner();
    2825             : 
    2826             :     /*
    2827             :      * Release any LW locks we might be holding as quickly as possible.
    2828             :      * (Regular locks, however, must be held till we finish aborting.)
    2829             :      * Releasing LW locks is critical since we might try to grab them again
    2830             :      * while cleaning up!
    2831             :      */
    2832       48344 :     LWLockReleaseAll();
    2833             : 
    2834             :     /* Clear wait information and command progress indicator */
    2835       48344 :     pgstat_report_wait_end();
    2836       48344 :     pgstat_progress_end_command();
    2837             : 
    2838       48344 :     pgaio_error_cleanup();
    2839             : 
    2840             :     /* Clean up buffer content locks, too */
    2841       48344 :     UnlockBuffers();
    2842             : 
    2843             :     /* Reset WAL record construction state */
    2844       48344 :     XLogResetInsertion();
    2845             : 
    2846             :     /* Cancel condition variable sleep */
    2847       48344 :     ConditionVariableCancelSleep();
    2848             : 
    2849             :     /*
    2850             :      * Also clean up any open wait for lock, since the lock manager will choke
    2851             :      * if we try to wait for another lock before doing this.
    2852             :      */
    2853       48344 :     LockErrorCleanup();
    2854             : 
    2855             :     /*
    2856             :      * If any timeout events are still active, make sure the timeout interrupt
    2857             :      * is scheduled.  This covers possible loss of a timeout interrupt due to
    2858             :      * longjmp'ing out of the SIGINT handler (see notes in handle_sig_alarm).
    2859             :      * We delay this till after LockErrorCleanup so that we don't uselessly
    2860             :      * reschedule lock or deadlock check timeouts.
    2861             :      */
    2862       48344 :     reschedule_timeouts();
    2863             : 
    2864             :     /*
    2865             :      * Re-enable signals, in case we got here by longjmp'ing out of a signal
    2866             :      * handler.  We do this fairly early in the sequence so that the timeout
    2867             :      * infrastructure will be functional if needed while aborting.
    2868             :      */
    2869       48344 :     sigprocmask(SIG_SETMASK, &UnBlockSig, NULL);
    2870             : 
    2871             :     /*
    2872             :      * check the current transaction state
    2873             :      */
    2874       48344 :     is_parallel_worker = (s->blockState == TBLOCK_PARALLEL_INPROGRESS);
    2875       48344 :     if (s->state != TRANS_INPROGRESS && s->state != TRANS_PREPARE)
    2876           0 :         elog(WARNING, "AbortTransaction while in %s state",
    2877             :              TransStateAsString(s->state));
    2878             :     Assert(s->parent == NULL);
    2879             : 
    2880             :     /*
    2881             :      * set the current transaction state information appropriately during the
    2882             :      * abort processing
    2883             :      */
    2884       48344 :     s->state = TRANS_ABORT;
    2885             : 
    2886             :     /*
    2887             :      * Reset user ID which might have been changed transiently.  We need this
    2888             :      * to clean up in case control escaped out of a SECURITY DEFINER function
    2889             :      * or other local change of CurrentUserId; therefore, the prior value of
    2890             :      * SecurityRestrictionContext also needs to be restored.
    2891             :      *
    2892             :      * (Note: it is not necessary to restore session authorization or role
    2893             :      * settings here because those can only be changed via GUC, and GUC will
    2894             :      * take care of rolling them back if need be.)
    2895             :      */
    2896       48344 :     SetUserIdAndSecContext(s->prevUser, s->prevSecContext);
    2897             : 
    2898             :     /* Forget about any active REINDEX. */
    2899       48344 :     ResetReindexState(s->nestingLevel);
    2900             : 
    2901             :     /* Reset logical streaming state. */
    2902       48344 :     ResetLogicalStreamingState();
    2903             : 
    2904             :     /* Reset snapshot export state. */
    2905       48344 :     SnapBuildResetExportedSnapshotState();
    2906             : 
    2907             :     /*
    2908             :      * If this xact has started any unfinished parallel operation, clean up
    2909             :      * its workers and exit parallel mode.  Don't warn about leaked resources.
    2910             :      */
    2911       48344 :     AtEOXact_Parallel(false);
    2912       48344 :     s->parallelModeLevel = 0;
    2913       48344 :     s->parallelChildXact = false;    /* should be false already */
    2914             : 
    2915             :     /*
    2916             :      * do abort processing
    2917             :      */
    2918       48344 :     AfterTriggerEndXact(false); /* 'false' means it's abort */
    2919       48344 :     AtAbort_Portals();
    2920       48344 :     smgrDoPendingSyncs(false, is_parallel_worker);
    2921       48344 :     AtEOXact_LargeObject(false);
    2922       48344 :     AtAbort_Notify();
    2923       48344 :     AtEOXact_RelationMap(false, is_parallel_worker);
    2924       48344 :     AtAbort_Twophase();
    2925             : 
    2926             :     /*
    2927             :      * Advertise the fact that we aborted in pg_xact (assuming that we got as
    2928             :      * far as assigning an XID to advertise).  But if we're inside a parallel
    2929             :      * worker, skip this; the user backend must be the one to write the abort
    2930             :      * record.
    2931             :      */
    2932       48344 :     if (!is_parallel_worker)
    2933       48332 :         latestXid = RecordTransactionAbort(false);
    2934             :     else
    2935             :     {
    2936          12 :         latestXid = InvalidTransactionId;
    2937             : 
    2938             :         /*
    2939             :          * Since the parallel leader won't get our value of XactLastRecEnd in
    2940             :          * this case, we nudge WAL-writer ourselves in this case.  See related
    2941             :          * comments in RecordTransactionAbort for why this matters.
    2942             :          */
    2943          12 :         XLogSetAsyncXactLSN(XactLastRecEnd);
    2944             :     }
    2945             : 
    2946             :     TRACE_POSTGRESQL_TRANSACTION_ABORT(MyProc->vxid.lxid);
    2947             : 
    2948             :     /*
    2949             :      * Let others know about no transaction in progress by me. Note that this
    2950             :      * must be done _before_ releasing locks we hold and _after_
    2951             :      * RecordTransactionAbort.
    2952             :      */
    2953       48344 :     ProcArrayEndTransaction(MyProc, latestXid);
    2954             : 
    2955             :     /*
    2956             :      * Post-abort cleanup.  See notes in CommitTransaction() concerning
    2957             :      * ordering.  We can skip all of it if the transaction failed before
    2958             :      * creating a resource owner.
    2959             :      */
    2960       48344 :     if (TopTransactionResourceOwner != NULL)
    2961             :     {
    2962       48344 :         if (is_parallel_worker)
    2963          12 :             CallXactCallbacks(XACT_EVENT_PARALLEL_ABORT);
    2964             :         else
    2965       48332 :             CallXactCallbacks(XACT_EVENT_ABORT);
    2966             : 
    2967       48344 :         ResourceOwnerRelease(TopTransactionResourceOwner,
    2968             :                              RESOURCE_RELEASE_BEFORE_LOCKS,
    2969             :                              false, true);
    2970       48344 :         AtEOXact_Aio(false);
    2971       48344 :         AtEOXact_Buffers(false);
    2972       48344 :         AtEOXact_RelationCache(false);
    2973       48344 :         AtEOXact_TypeCache();
    2974       48344 :         AtEOXact_Inval(false);
    2975       48344 :         AtEOXact_MultiXact();
    2976       48344 :         ResourceOwnerRelease(TopTransactionResourceOwner,
    2977             :                              RESOURCE_RELEASE_LOCKS,
    2978             :                              false, true);
    2979       48344 :         ResourceOwnerRelease(TopTransactionResourceOwner,
    2980             :                              RESOURCE_RELEASE_AFTER_LOCKS,
    2981             :                              false, true);
    2982       48344 :         smgrDoPendingDeletes(false);
    2983             : 
    2984       48344 :         AtEOXact_GUC(false, 1);
    2985       48344 :         AtEOXact_SPI(false);
    2986       48344 :         AtEOXact_Enum();
    2987       48344 :         AtEOXact_on_commit_actions(false);
    2988       48344 :         AtEOXact_Namespace(false, is_parallel_worker);
    2989       48344 :         AtEOXact_SMgr();
    2990       48344 :         AtEOXact_Files(false);
    2991       48344 :         AtEOXact_ComboCid();
    2992       48344 :         AtEOXact_HashTables(false);
    2993       48344 :         AtEOXact_PgStat(false, is_parallel_worker);
    2994       48344 :         AtEOXact_ApplyLauncher(false);
    2995       48344 :         AtEOXact_LogicalRepWorkers(false);
    2996       48344 :         pgstat_report_xact_timestamp(0);
    2997             :     }
    2998             : 
    2999             :     /*
    3000             :      * State remains TRANS_ABORT until CleanupTransaction().
    3001             :      */
    3002       48344 :     RESUME_INTERRUPTS();
    3003       48344 : }
    3004             : 
    3005             : /*
    3006             :  *  CleanupTransaction
    3007             :  */
    3008             : static void
    3009       48344 : CleanupTransaction(void)
    3010             : {
    3011       48344 :     TransactionState s = CurrentTransactionState;
    3012             : 
    3013             :     /*
    3014             :      * State should still be TRANS_ABORT from AbortTransaction().
    3015             :      */
    3016       48344 :     if (s->state != TRANS_ABORT)
    3017           0 :         elog(FATAL, "CleanupTransaction: unexpected state %s",
    3018             :              TransStateAsString(s->state));
    3019             : 
    3020             :     /*
    3021             :      * do abort cleanup processing
    3022             :      */
    3023       48344 :     AtCleanup_Portals();        /* now safe to release portal memory */
    3024       48344 :     AtEOXact_Snapshot(false, true); /* and release the transaction's snapshots */
    3025             : 
    3026       48344 :     CurrentResourceOwner = NULL;    /* and resource owner */
    3027       48344 :     if (TopTransactionResourceOwner)
    3028       48344 :         ResourceOwnerDelete(TopTransactionResourceOwner);
    3029       48344 :     s->curTransactionOwner = NULL;
    3030       48344 :     CurTransactionResourceOwner = NULL;
    3031       48344 :     TopTransactionResourceOwner = NULL;
    3032             : 
    3033       48344 :     AtCleanup_Memory();         /* and transaction memory */
    3034             : 
    3035       48344 :     s->fullTransactionId = InvalidFullTransactionId;
    3036       48344 :     s->subTransactionId = InvalidSubTransactionId;
    3037       48344 :     s->nestingLevel = 0;
    3038       48344 :     s->gucNestLevel = 0;
    3039       48344 :     s->childXids = NULL;
    3040       48344 :     s->nChildXids = 0;
    3041       48344 :     s->maxChildXids = 0;
    3042       48344 :     s->parallelModeLevel = 0;
    3043       48344 :     s->parallelChildXact = false;
    3044             : 
    3045       48344 :     XactTopFullTransactionId = InvalidFullTransactionId;
    3046       48344 :     nParallelCurrentXids = 0;
    3047             : 
    3048             :     /*
    3049             :      * done with abort processing, set current transaction state back to
    3050             :      * default
    3051             :      */
    3052       48344 :     s->state = TRANS_DEFAULT;
    3053       48344 : }
    3054             : 
    3055             : /*
    3056             :  *  StartTransactionCommand
    3057             :  */
    3058             : void
    3059      995530 : StartTransactionCommand(void)
    3060             : {
    3061      995530 :     TransactionState s = CurrentTransactionState;
    3062             : 
    3063      995530 :     switch (s->blockState)
    3064             :     {
    3065             :             /*
    3066             :              * if we aren't in a transaction block, we just do our usual start
    3067             :              * transaction.
    3068             :              */
    3069      815624 :         case TBLOCK_DEFAULT:
    3070      815624 :             StartTransaction();
    3071      815624 :             s->blockState = TBLOCK_STARTED;
    3072      815624 :             break;
    3073             : 
    3074             :             /*
    3075             :              * We are somewhere in a transaction block or subtransaction and
    3076             :              * about to start a new command.  For now we do nothing, but
    3077             :              * someday we may do command-local resource initialization. (Note
    3078             :              * that any needed CommandCounterIncrement was done by the
    3079             :              * previous CommitTransactionCommand.)
    3080             :              */
    3081      178150 :         case TBLOCK_INPROGRESS:
    3082             :         case TBLOCK_IMPLICIT_INPROGRESS:
    3083             :         case TBLOCK_SUBINPROGRESS:
    3084      178150 :             break;
    3085             : 
    3086             :             /*
    3087             :              * Here we are in a failed transaction block (one of the commands
    3088             :              * caused an abort) so we do nothing but remain in the abort
    3089             :              * state.  Eventually we will get a ROLLBACK command which will
    3090             :              * get us out of this state.  (It is up to other code to ensure
    3091             :              * that no commands other than ROLLBACK will be processed in these
    3092             :              * states.)
    3093             :              */
    3094        1756 :         case TBLOCK_ABORT:
    3095             :         case TBLOCK_SUBABORT:
    3096        1756 :             break;
    3097             : 
    3098             :             /* These cases are invalid. */
    3099           0 :         case TBLOCK_STARTED:
    3100             :         case TBLOCK_BEGIN:
    3101             :         case TBLOCK_PARALLEL_INPROGRESS:
    3102             :         case TBLOCK_SUBBEGIN:
    3103             :         case TBLOCK_END:
    3104             :         case TBLOCK_SUBRELEASE:
    3105             :         case TBLOCK_SUBCOMMIT:
    3106             :         case TBLOCK_ABORT_END:
    3107             :         case TBLOCK_SUBABORT_END:
    3108             :         case TBLOCK_ABORT_PENDING:
    3109             :         case TBLOCK_SUBABORT_PENDING:
    3110             :         case TBLOCK_SUBRESTART:
    3111             :         case TBLOCK_SUBABORT_RESTART:
    3112             :         case TBLOCK_PREPARE:
    3113           0 :             elog(ERROR, "StartTransactionCommand: unexpected state %s",
    3114             :                  BlockStateAsString(s->blockState));
    3115             :             break;
    3116             :     }
    3117             : 
    3118             :     /*
    3119             :      * We must switch to CurTransactionContext before returning. This is
    3120             :      * already done if we called StartTransaction, otherwise not.
    3121             :      */
    3122      995530 :     Assert(CurTransactionContext != NULL);
    3123      995530 :     MemoryContextSwitchTo(CurTransactionContext);
    3124      995530 : }
    3125             : 
    3126             : 
    3127             : /*
    3128             :  * Simple system for saving and restoring transaction characteristics
    3129             :  * (isolation level, read only, deferrable).  We need this for transaction
    3130             :  * chaining, so that we can set the characteristics of the new transaction to
    3131             :  * be the same as the previous one.  (We need something like this because the
    3132             :  * GUC system resets the characteristics at transaction end, so for example
    3133             :  * just skipping the reset in StartTransaction() won't work.)
    3134             :  */
    3135             : void
    3136      950648 : SaveTransactionCharacteristics(SavedTransactionCharacteristics *s)
    3137             : {
    3138      950648 :     s->save_XactIsoLevel = XactIsoLevel;
    3139      950648 :     s->save_XactReadOnly = XactReadOnly;
    3140      950648 :     s->save_XactDeferrable = XactDeferrable;
    3141      950648 : }
    3142             : 
    3143             : void
    3144          68 : RestoreTransactionCharacteristics(const SavedTransactionCharacteristics *s)
    3145             : {
    3146          68 :     XactIsoLevel = s->save_XactIsoLevel;
    3147          68 :     XactReadOnly = s->save_XactReadOnly;
    3148          68 :     XactDeferrable = s->save_XactDeferrable;
    3149          68 : }
    3150             : 
    3151             : /*
    3152             :  *  CommitTransactionCommand -- a wrapper function handling the
    3153             :  *      loop over subtransactions to avoid a potentially dangerous recursion
    3154             :  *      in CommitTransactionCommandInternal().
    3155             :  */
    3156             : void
    3157      950210 : CommitTransactionCommand(void)
    3158             : {
    3159             :     /*
    3160             :      * Repeatedly call CommitTransactionCommandInternal() until all the work
    3161             :      * is done.
    3162             :      */
    3163      950640 :     while (!CommitTransactionCommandInternal())
    3164             :     {
    3165             :     }
    3166      949642 : }
    3167             : 
    3168             : /*
    3169             :  *  CommitTransactionCommandInternal - a function doing an iteration of work
    3170             :  *      regarding handling the commit transaction command.  In the case of
    3171             :  *      subtransactions more than one iterations could be required.  Returns
    3172             :  *      true when no more iterations required, false otherwise.
    3173             :  */
    3174             : static bool
    3175      950640 : CommitTransactionCommandInternal(void)
    3176             : {
    3177      950640 :     TransactionState s = CurrentTransactionState;
    3178             :     SavedTransactionCharacteristics savetc;
    3179             : 
    3180             :     /* Must save in case we need to restore below */
    3181      950640 :     SaveTransactionCharacteristics(&savetc);
    3182             : 
    3183      950640 :     switch (s->blockState)
    3184             :     {
    3185             :             /*
    3186             :              * These shouldn't happen.  TBLOCK_DEFAULT means the previous
    3187             :              * StartTransactionCommand didn't set the STARTED state
    3188             :              * appropriately, while TBLOCK_PARALLEL_INPROGRESS should be ended
    3189             :              * by EndParallelWorkerTransaction(), not this function.
    3190             :              */
    3191           0 :         case TBLOCK_DEFAULT:
    3192             :         case TBLOCK_PARALLEL_INPROGRESS:
    3193           0 :             elog(FATAL, "CommitTransactionCommand: unexpected state %s",
    3194             :                  BlockStateAsString(s->blockState));
    3195             :             break;
    3196             : 
    3197             :             /*
    3198             :              * If we aren't in a transaction block, just do our usual
    3199             :              * transaction commit, and return to the idle state.
    3200             :              */
    3201      755740 :         case TBLOCK_STARTED:
    3202      755740 :             CommitTransaction();
    3203      755720 :             s->blockState = TBLOCK_DEFAULT;
    3204      755720 :             break;
    3205             : 
    3206             :             /*
    3207             :              * We are completing a "BEGIN TRANSACTION" command, so we change
    3208             :              * to the "transaction block in progress" state and return.  (We
    3209             :              * assume the BEGIN did nothing to the database, so we need no
    3210             :              * CommandCounterIncrement.)
    3211             :              */
    3212       16136 :         case TBLOCK_BEGIN:
    3213       16136 :             s->blockState = TBLOCK_INPROGRESS;
    3214       16136 :             break;
    3215             : 
    3216             :             /*
    3217             :              * This is the case when we have finished executing a command
    3218             :              * someplace within a transaction block.  We increment the command
    3219             :              * counter and return.
    3220             :              */
    3221      142400 :         case TBLOCK_INPROGRESS:
    3222             :         case TBLOCK_IMPLICIT_INPROGRESS:
    3223             :         case TBLOCK_SUBINPROGRESS:
    3224      142400 :             CommandCounterIncrement();
    3225      142400 :             break;
    3226             : 
    3227             :             /*
    3228             :              * We are completing a "COMMIT" command.  Do it and return to the
    3229             :              * idle state.
    3230             :              */
    3231       10806 :         case TBLOCK_END:
    3232       10806 :             CommitTransaction();
    3233       10382 :             s->blockState = TBLOCK_DEFAULT;
    3234       10382 :             if (s->chain)
    3235             :             {
    3236          12 :                 StartTransaction();
    3237          12 :                 s->blockState = TBLOCK_INPROGRESS;
    3238          12 :                 s->chain = false;
    3239          12 :                 RestoreTransactionCharacteristics(&savetc);
    3240             :             }
    3241       10382 :             break;
    3242             : 
    3243             :             /*
    3244             :              * Here we are in the middle of a transaction block but one of the
    3245             :              * commands caused an abort so we do nothing but remain in the
    3246             :              * abort state.  Eventually we will get a ROLLBACK command.
    3247             :              */
    3248          18 :         case TBLOCK_ABORT:
    3249             :         case TBLOCK_SUBABORT:
    3250          18 :             break;
    3251             : 
    3252             :             /*
    3253             :              * Here we were in an aborted transaction block and we just got
    3254             :              * the ROLLBACK command from the user, so clean up the
    3255             :              * already-aborted transaction and return to the idle state.
    3256             :              */
    3257        1366 :         case TBLOCK_ABORT_END:
    3258        1366 :             CleanupTransaction();
    3259        1366 :             s->blockState = TBLOCK_DEFAULT;
    3260        1366 :             if (s->chain)
    3261             :             {
    3262          12 :                 StartTransaction();
    3263          12 :                 s->blockState = TBLOCK_INPROGRESS;
    3264          12 :                 s->chain = false;
    3265          12 :                 RestoreTransactionCharacteristics(&savetc);
    3266             :             }
    3267        1366 :             break;
    3268             : 
    3269             :             /*
    3270             :              * Here we were in a perfectly good transaction block but the user
    3271             :              * told us to ROLLBACK anyway.  We have to abort the transaction
    3272             :              * and then clean up.
    3273             :              */
    3274        2152 :         case TBLOCK_ABORT_PENDING:
    3275        2152 :             AbortTransaction();
    3276        2152 :             CleanupTransaction();
    3277        2152 :             s->blockState = TBLOCK_DEFAULT;
    3278        2152 :             if (s->chain)
    3279             :             {
    3280          18 :                 StartTransaction();
    3281          18 :                 s->blockState = TBLOCK_INPROGRESS;
    3282          18 :                 s->chain = false;
    3283          18 :                 RestoreTransactionCharacteristics(&savetc);
    3284             :             }
    3285        2152 :             break;
    3286             : 
    3287             :             /*
    3288             :              * We are completing a "PREPARE TRANSACTION" command.  Do it and
    3289             :              * return to the idle state.
    3290             :              */
    3291         468 :         case TBLOCK_PREPARE:
    3292         468 :             PrepareTransaction();
    3293         372 :             s->blockState = TBLOCK_DEFAULT;
    3294         372 :             break;
    3295             : 
    3296             :             /*
    3297             :              * The user issued a SAVEPOINT inside a transaction block. Start a
    3298             :              * subtransaction.  (DefineSavepoint already did PushTransaction,
    3299             :              * so as to have someplace to put the SUBBEGIN state.)
    3300             :              */
    3301       19224 :         case TBLOCK_SUBBEGIN:
    3302       19224 :             StartSubTransaction();
    3303       19224 :             s->blockState = TBLOCK_SUBINPROGRESS;
    3304       19224 :             break;
    3305             : 
    3306             :             /*
    3307             :              * The user issued a RELEASE command, so we end the current
    3308             :              * subtransaction and return to the parent transaction. The parent
    3309             :              * might be ended too, so repeat till we find an INPROGRESS
    3310             :              * transaction or subtransaction.
    3311             :              */
    3312         172 :         case TBLOCK_SUBRELEASE:
    3313             :             do
    3314             :             {
    3315         448 :                 CommitSubTransaction();
    3316         448 :                 s = CurrentTransactionState;    /* changed by pop */
    3317         448 :             } while (s->blockState == TBLOCK_SUBRELEASE);
    3318             : 
    3319             :             Assert(s->blockState == TBLOCK_INPROGRESS ||
    3320             :                    s->blockState == TBLOCK_SUBINPROGRESS);
    3321         276 :             break;
    3322             : 
    3323             :             /*
    3324             :              * The user issued a COMMIT, so we end the current subtransaction
    3325             :              * hierarchy and perform final commit. We do this by rolling up
    3326             :              * any subtransactions into their parent, which leads to O(N^2)
    3327             :              * operations with respect to resource owners - this isn't that
    3328             :              * bad until we approach a thousands of savepoints but is
    3329             :              * necessary for correctness should after triggers create new
    3330             :              * resource owners.
    3331             :              */
    3332         134 :         case TBLOCK_SUBCOMMIT:
    3333             :             do
    3334             :             {
    3335        1040 :                 CommitSubTransaction();
    3336        1040 :                 s = CurrentTransactionState;    /* changed by pop */
    3337        1040 :             } while (s->blockState == TBLOCK_SUBCOMMIT);
    3338             :             /* If we had a COMMIT command, finish off the main xact too */
    3339         906 :             if (s->blockState == TBLOCK_END)
    3340             :             {
    3341             :                 Assert(s->parent == NULL);
    3342         666 :                 CommitTransaction();
    3343         640 :                 s->blockState = TBLOCK_DEFAULT;
    3344         640 :                 if (s->chain)
    3345             :                 {
    3346          18 :                     StartTransaction();
    3347          18 :                     s->blockState = TBLOCK_INPROGRESS;
    3348          18 :                     s->chain = false;
    3349          18 :                     RestoreTransactionCharacteristics(&savetc);
    3350             :                 }
    3351             :             }
    3352         240 :             else if (s->blockState == TBLOCK_PREPARE)
    3353             :             {
    3354             :                 Assert(s->parent == NULL);
    3355         240 :                 PrepareTransaction();
    3356         238 :                 s->blockState = TBLOCK_DEFAULT;
    3357             :             }
    3358             :             else
    3359           0 :                 elog(ERROR, "CommitTransactionCommand: unexpected state %s",
    3360             :                      BlockStateAsString(s->blockState));
    3361         878 :             break;
    3362             : 
    3363             :             /*
    3364             :              * The current already-failed subtransaction is ending due to a
    3365             :              * ROLLBACK or ROLLBACK TO command, so pop it and recursively
    3366             :              * examine the parent (which could be in any of several states).
    3367             :              * As we need to examine the parent, return false to request the
    3368             :              * caller to do the next iteration.
    3369             :              */
    3370          80 :         case TBLOCK_SUBABORT_END:
    3371          80 :             CleanupSubTransaction();
    3372          80 :             return false;
    3373             : 
    3374             :             /*
    3375             :              * As above, but it's not dead yet, so abort first.
    3376             :              */
    3377         350 :         case TBLOCK_SUBABORT_PENDING:
    3378         350 :             AbortSubTransaction();
    3379         350 :             CleanupSubTransaction();
    3380         350 :             return false;
    3381             : 
    3382             :             /*
    3383             :              * The current subtransaction is the target of a ROLLBACK TO
    3384             :              * command.  Abort and pop it, then start a new subtransaction
    3385             :              * with the same name.
    3386             :              */
    3387         520 :         case TBLOCK_SUBRESTART:
    3388             :             {
    3389             :                 char       *name;
    3390             :                 int         savepointLevel;
    3391             : 
    3392             :                 /* save name and keep Cleanup from freeing it */
    3393         520 :                 name = s->name;
    3394         520 :                 s->name = NULL;
    3395         520 :                 savepointLevel = s->savepointLevel;
    3396             : 
    3397         520 :                 AbortSubTransaction();
    3398         520 :                 CleanupSubTransaction();
    3399             : 
    3400         520 :                 DefineSavepoint(NULL);
    3401         520 :                 s = CurrentTransactionState;    /* changed by push */
    3402         520 :                 s->name = name;
    3403         520 :                 s->savepointLevel = savepointLevel;
    3404             : 
    3405             :                 /* This is the same as TBLOCK_SUBBEGIN case */
    3406             :                 Assert(s->blockState == TBLOCK_SUBBEGIN);
    3407         520 :                 StartSubTransaction();
    3408         520 :                 s->blockState = TBLOCK_SUBINPROGRESS;
    3409             :             }
    3410         520 :             break;
    3411             : 
    3412             :             /*
    3413             :              * Same as above, but the subtransaction had already failed, so we
    3414             :              * don't need AbortSubTransaction.
    3415             :              */
    3416         198 :         case TBLOCK_SUBABORT_RESTART:
    3417             :             {
    3418             :                 char       *name;
    3419             :                 int         savepointLevel;
    3420             : 
    3421             :                 /* save name and keep Cleanup from freeing it */
    3422         198 :                 name = s->name;
    3423         198 :                 s->name = NULL;
    3424         198 :                 savepointLevel = s->savepointLevel;
    3425             : 
    3426         198 :                 CleanupSubTransaction();
    3427             : 
    3428         198 :                 DefineSavepoint(NULL);
    3429         198 :                 s = CurrentTransactionState;    /* changed by push */
    3430         198 :                 s->name = name;
    3431         198 :                 s->savepointLevel = savepointLevel;
    3432             : 
    3433             :                 /* This is the same as TBLOCK_SUBBEGIN case */
    3434             :                 Assert(s->blockState == TBLOCK_SUBBEGIN);
    3435         198 :                 StartSubTransaction();
    3436         198 :                 s->blockState = TBLOCK_SUBINPROGRESS;
    3437             :             }
    3438         198 :             break;
    3439             :     }
    3440             : 
    3441             :     /* Done, no more iterations required */
    3442      949642 :     return true;
    3443             : }
    3444             : 
    3445             : /*
    3446             :  *  AbortCurrentTransaction -- a wrapper function handling the
    3447             :  *      loop over subtransactions to avoid potentially dangerous recursion in
    3448             :  *      AbortCurrentTransactionInternal().
    3449             :  */
    3450             : void
    3451       47564 : AbortCurrentTransaction(void)
    3452             : {
    3453             :     /*
    3454             :      * Repeatedly call AbortCurrentTransactionInternal() until all the work is
    3455             :      * done.
    3456             :      */
    3457       47564 :     while (!AbortCurrentTransactionInternal())
    3458             :     {
    3459             :     }
    3460       47564 : }
    3461             : 
    3462             : /*
    3463             :  *  AbortCurrentTransactionInternal - a function doing an iteration of work
    3464             :  *      regarding handling the current transaction abort.  In the case of
    3465             :  *      subtransactions more than one iterations could be required.  Returns
    3466             :  *      true when no more iterations required, false otherwise.
    3467             :  */
    3468             : static bool
    3469       47564 : AbortCurrentTransactionInternal(void)
    3470             : {
    3471       47564 :     TransactionState s = CurrentTransactionState;
    3472             : 
    3473       47564 :     switch (s->blockState)
    3474             :     {
    3475          98 :         case TBLOCK_DEFAULT:
    3476          98 :             if (s->state == TRANS_DEFAULT)
    3477             :             {
    3478             :                 /* we are idle, so nothing to do */
    3479             :             }
    3480             :             else
    3481             :             {
    3482             :                 /*
    3483             :                  * We can get here after an error during transaction start
    3484             :                  * (state will be TRANS_START).  Need to clean up the
    3485             :                  * incompletely started transaction.  First, adjust the
    3486             :                  * low-level state to suppress warning message from
    3487             :                  * AbortTransaction.
    3488             :                  */
    3489           0 :                 if (s->state == TRANS_START)
    3490           0 :                     s->state = TRANS_INPROGRESS;
    3491           0 :                 AbortTransaction();
    3492           0 :                 CleanupTransaction();
    3493             :             }
    3494          98 :             break;
    3495             : 
    3496             :             /*
    3497             :              * If we aren't in a transaction block, we just do the basic abort
    3498             :              * & cleanup transaction.  For this purpose, we treat an implicit
    3499             :              * transaction block as if it were a simple statement.
    3500             :              */
    3501       43332 :         case TBLOCK_STARTED:
    3502             :         case TBLOCK_IMPLICIT_INPROGRESS:
    3503       43332 :             AbortTransaction();
    3504       43332 :             CleanupTransaction();
    3505       43332 :             s->blockState = TBLOCK_DEFAULT;
    3506       43332 :             break;
    3507             : 
    3508             :             /*
    3509             :              * If we are in TBLOCK_BEGIN it means something screwed up right
    3510             :              * after reading "BEGIN TRANSACTION".  We assume that the user
    3511             :              * will interpret the error as meaning the BEGIN failed to get him
    3512             :              * into a transaction block, so we should abort and return to idle
    3513             :              * state.
    3514             :              */
    3515           0 :         case TBLOCK_BEGIN:
    3516           0 :             AbortTransaction();
    3517           0 :             CleanupTransaction();
    3518           0 :             s->blockState = TBLOCK_DEFAULT;
    3519           0 :             break;
    3520             : 
    3521             :             /*
    3522             :              * We are somewhere in a transaction block and we've gotten a
    3523             :              * failure, so we abort the transaction and set up the persistent
    3524             :              * ABORT state.  We will stay in ABORT until we get a ROLLBACK.
    3525             :              */
    3526        1388 :         case TBLOCK_INPROGRESS:
    3527             :         case TBLOCK_PARALLEL_INPROGRESS:
    3528        1388 :             AbortTransaction();
    3529        1388 :             s->blockState = TBLOCK_ABORT;
    3530             :             /* CleanupTransaction happens when we exit TBLOCK_ABORT_END */
    3531        1388 :             break;
    3532             : 
    3533             :             /*
    3534             :              * Here, we failed while trying to COMMIT.  Clean up the
    3535             :              * transaction and return to idle state (we do not want to stay in
    3536             :              * the transaction).
    3537             :              */
    3538         450 :         case TBLOCK_END:
    3539         450 :             AbortTransaction();
    3540         450 :             CleanupTransaction();
    3541         450 :             s->blockState = TBLOCK_DEFAULT;
    3542         450 :             break;
    3543             : 
    3544             :             /*
    3545             :              * Here, we are already in an aborted transaction state and are
    3546             :              * waiting for a ROLLBACK, but for some reason we failed again! So
    3547             :              * we just remain in the abort state.
    3548             :              */
    3549          96 :         case TBLOCK_ABORT:
    3550             :         case TBLOCK_SUBABORT:
    3551          96 :             break;
    3552             : 
    3553             :             /*
    3554             :              * We are in a failed transaction and we got the ROLLBACK command.
    3555             :              * We have already aborted, we just need to cleanup and go to idle
    3556             :              * state.
    3557             :              */
    3558           0 :         case TBLOCK_ABORT_END:
    3559           0 :             CleanupTransaction();
    3560           0 :             s->blockState = TBLOCK_DEFAULT;
    3561           0 :             break;
    3562             : 
    3563             :             /*
    3564             :              * We are in a live transaction and we got a ROLLBACK command.
    3565             :              * Abort, cleanup, go to idle state.
    3566             :              */
    3567           0 :         case TBLOCK_ABORT_PENDING:
    3568           0 :             AbortTransaction();
    3569           0 :             CleanupTransaction();
    3570           0 :             s->blockState = TBLOCK_DEFAULT;
    3571           0 :             break;
    3572             : 
    3573             :             /*
    3574             :              * Here, we failed while trying to PREPARE.  Clean up the
    3575             :              * transaction and return to idle state (we do not want to stay in
    3576             :              * the transaction).
    3577             :              */
    3578          96 :         case TBLOCK_PREPARE:
    3579          96 :             AbortTransaction();
    3580          96 :             CleanupTransaction();
    3581          96 :             s->blockState = TBLOCK_DEFAULT;
    3582          96 :             break;
    3583             : 
    3584             :             /*
    3585             :              * We got an error inside a subtransaction.  Abort just the
    3586             :              * subtransaction, and go to the persistent SUBABORT state until
    3587             :              * we get ROLLBACK.
    3588             :              */
    3589        2104 :         case TBLOCK_SUBINPROGRESS:
    3590        2104 :             AbortSubTransaction();
    3591        2104 :             s->blockState = TBLOCK_SUBABORT;
    3592        2104 :             break;
    3593             : 
    3594             :             /*
    3595             :              * If we failed while trying to create a subtransaction, clean up
    3596             :              * the broken subtransaction and abort the parent.  The same
    3597             :              * applies if we get a failure while ending a subtransaction.  As
    3598             :              * we need to abort the parent, return false to request the caller
    3599             :              * to do the next iteration.
    3600             :              */
    3601           0 :         case TBLOCK_SUBBEGIN:
    3602             :         case TBLOCK_SUBRELEASE:
    3603             :         case TBLOCK_SUBCOMMIT:
    3604             :         case TBLOCK_SUBABORT_PENDING:
    3605             :         case TBLOCK_SUBRESTART:
    3606           0 :             AbortSubTransaction();
    3607           0 :             CleanupSubTransaction();
    3608           0 :             return false;
    3609             : 
    3610             :             /*
    3611             :              * Same as above, except the Abort() was already done.
    3612             :              */
    3613           0 :         case TBLOCK_SUBABORT_END:
    3614             :         case TBLOCK_SUBABORT_RESTART:
    3615           0 :             CleanupSubTransaction();
    3616           0 :             return false;
    3617             :     }
    3618             : 
    3619             :     /* Done, no more iterations required */
    3620       47564 :     return true;
    3621             : }
    3622             : 
    3623             : /*
    3624             :  *  PreventInTransactionBlock
    3625             :  *
    3626             :  *  This routine is to be called by statements that must not run inside
    3627             :  *  a transaction block, typically because they have non-rollback-able
    3628             :  *  side effects or do internal commits.
    3629             :  *
    3630             :  *  If this routine completes successfully, then the calling statement is
    3631             :  *  guaranteed that if it completes without error, its results will be
    3632             :  *  committed immediately.
    3633             :  *
    3634             :  *  If we have already started a transaction block, issue an error; also issue
    3635             :  *  an error if we appear to be running inside a user-defined function (which
    3636             :  *  could issue more commands and possibly cause a failure after the statement
    3637             :  *  completes).  Subtransactions are verboten too.
    3638             :  *
    3639             :  *  We must also set XACT_FLAGS_NEEDIMMEDIATECOMMIT in MyXactFlags, to ensure
    3640             :  *  that postgres.c follows through by committing after the statement is done.
    3641             :  *
    3642             :  *  isTopLevel: passed down from ProcessUtility to determine whether we are
    3643             :  *  inside a function.  (We will always fail if this is false, but it's
    3644             :  *  convenient to centralize the check here instead of making callers do it.)
    3645             :  *  stmtType: statement type name, for error messages.
    3646             :  */
    3647             : void
    3648      107986 : PreventInTransactionBlock(bool isTopLevel, const char *stmtType)
    3649             : {
    3650             :     /*
    3651             :      * xact block already started?
    3652             :      */
    3653      107986 :     if (IsTransactionBlock())
    3654         118 :         ereport(ERROR,
    3655             :                 (errcode(ERRCODE_ACTIVE_SQL_TRANSACTION),
    3656             :         /* translator: %s represents an SQL statement name */
    3657             :                  errmsg("%s cannot run inside a transaction block",
    3658             :                         stmtType)));
    3659             : 
    3660             :     /*
    3661             :      * subtransaction?
    3662             :      */
    3663      107868 :     if (IsSubTransaction())
    3664           0 :         ereport(ERROR,
    3665             :                 (errcode(ERRCODE_ACTIVE_SQL_TRANSACTION),
    3666             :         /* translator: %s represents an SQL statement name */
    3667             :                  errmsg("%s cannot run inside a subtransaction",
    3668             :                         stmtType)));
    3669             : 
    3670             :     /*
    3671             :      * inside a function call?
    3672             :      */
    3673      107868 :     if (!isTopLevel)
    3674           6 :         ereport(ERROR,
    3675             :                 (errcode(ERRCODE_ACTIVE_SQL_TRANSACTION),
    3676             :         /* translator: %s represents an SQL statement name */
    3677             :                  errmsg("%s cannot be executed from a function", stmtType)));
    3678             : 
    3679             :     /* If we got past IsTransactionBlock test, should be in default state */
    3680      107862 :     if (CurrentTransactionState->blockState != TBLOCK_DEFAULT &&
    3681      106198 :         CurrentTransactionState->blockState != TBLOCK_STARTED)
    3682           0 :         elog(FATAL, "cannot prevent transaction chain");
    3683             : 
    3684             :     /* All okay.  Set the flag to make sure the right thing happens later. */
    3685      107862 :     MyXactFlags |= XACT_FLAGS_NEEDIMMEDIATECOMMIT;
    3686      107862 : }
    3687             : 
    3688             : /*
    3689             :  *  WarnNoTransactionBlock
    3690             :  *  RequireTransactionBlock
    3691             :  *
    3692             :  *  These two functions allow for warnings or errors if a command is executed
    3693             :  *  outside of a transaction block.  This is useful for commands that have no
    3694             :  *  effects that persist past transaction end (and so calling them outside a
    3695             :  *  transaction block is presumably an error).  DECLARE CURSOR is an example.
    3696             :  *  While top-level transaction control commands (BEGIN/COMMIT/ABORT) and SET
    3697             :  *  that have no effect issue warnings, all other no-effect commands generate
    3698             :  *  errors.
    3699             :  *
    3700             :  *  If we appear to be running inside a user-defined function, we do not
    3701             :  *  issue anything, since the function could issue more commands that make
    3702             :  *  use of the current statement's results.  Likewise subtransactions.
    3703             :  *  Thus these are inverses for PreventInTransactionBlock.
    3704             :  *
    3705             :  *  isTopLevel: passed down from ProcessUtility to determine whether we are
    3706             :  *  inside a function.
    3707             :  *  stmtType: statement type name, for warning or error messages.
    3708             :  */
    3709             : void
    3710        1984 : WarnNoTransactionBlock(bool isTopLevel, const char *stmtType)
    3711             : {
    3712        1984 :     CheckTransactionBlock(isTopLevel, false, stmtType);
    3713        1984 : }
    3714             : 
    3715             : void
    3716        8420 : RequireTransactionBlock(bool isTopLevel, const char *stmtType)
    3717             : {
    3718        8420 :     CheckTransactionBlock(isTopLevel, true, stmtType);
    3719        8384 : }
    3720             : 
    3721             : /*
    3722             :  * This is the implementation of the above two.
    3723             :  */
    3724             : static void
    3725       10404 : CheckTransactionBlock(bool isTopLevel, bool throwError, const char *stmtType)
    3726             : {
    3727             :     /*
    3728             :      * xact block already started?
    3729             :      */
    3730       10404 :     if (IsTransactionBlock())
    3731       10230 :         return;
    3732             : 
    3733             :     /*
    3734             :      * subtransaction?
    3735             :      */
    3736         174 :     if (IsSubTransaction())
    3737           0 :         return;
    3738             : 
    3739             :     /*
    3740             :      * inside a function call?
    3741             :      */
    3742         174 :     if (!isTopLevel)
    3743         116 :         return;
    3744             : 
    3745          58 :     ereport(throwError ? ERROR : WARNING,
    3746             :             (errcode(ERRCODE_NO_ACTIVE_SQL_TRANSACTION),
    3747             :     /* translator: %s represents an SQL statement name */
    3748             :              errmsg("%s can only be used in transaction blocks",
    3749             :                     stmtType)));
    3750             : }
    3751             : 
    3752             : /*
    3753             :  *  IsInTransactionBlock
    3754             :  *
    3755             :  *  This routine is for statements that need to behave differently inside
    3756             :  *  a transaction block than when running as single commands.  ANALYZE is
    3757             :  *  currently the only example.
    3758             :  *
    3759             :  *  If this routine returns "false", then the calling statement is allowed
    3760             :  *  to perform internal transaction-commit-and-start cycles; there is not a
    3761             :  *  risk of messing up any transaction already in progress.  (Note that this
    3762             :  *  is not the identical guarantee provided by PreventInTransactionBlock,
    3763             :  *  since we will not force a post-statement commit.)
    3764             :  *
    3765             :  *  isTopLevel: passed down from ProcessUtility to determine whether we are
    3766             :  *  inside a function.
    3767             :  */
    3768             : bool
    3769        4820 : IsInTransactionBlock(bool isTopLevel)
    3770             : {
    3771             :     /*
    3772             :      * Return true on same conditions that would make
    3773             :      * PreventInTransactionBlock error out
    3774             :      */
    3775        4820 :     if (IsTransactionBlock())
    3776         138 :         return true;
    3777             : 
    3778        4682 :     if (IsSubTransaction())
    3779           0 :         return true;
    3780             : 
    3781        4682 :     if (!isTopLevel)
    3782         112 :         return true;
    3783             : 
    3784        4570 :     if (CurrentTransactionState->blockState != TBLOCK_DEFAULT &&
    3785        4570 :         CurrentTransactionState->blockState != TBLOCK_STARTED)
    3786           0 :         return true;
    3787             : 
    3788        4570 :     return false;
    3789             : }
    3790             : 
    3791             : 
    3792             : /*
    3793             :  * Register or deregister callback functions for start- and end-of-xact
    3794             :  * operations.
    3795             :  *
    3796             :  * These functions are intended for use by dynamically loaded modules.
    3797             :  * For built-in modules we generally just hardwire the appropriate calls
    3798             :  * (mainly because it's easier to control the order that way, where needed).
    3799             :  *
    3800             :  * At transaction end, the callback occurs post-commit or post-abort, so the
    3801             :  * callback functions can only do noncritical cleanup.
    3802             :  */
    3803             : void
    3804        3526 : RegisterXactCallback(XactCallback callback, void *arg)
    3805             : {
    3806             :     XactCallbackItem *item;
    3807             : 
    3808             :     item = (XactCallbackItem *)
    3809        3526 :         MemoryContextAlloc(TopMemoryContext, sizeof(XactCallbackItem));
    3810        3526 :     item->callback = callback;
    3811        3526 :     item->arg = arg;
    3812        3526 :     item->next = Xact_callbacks;
    3813        3526 :     Xact_callbacks = item;
    3814        3526 : }
    3815             : 
    3816             : void
    3817           0 : UnregisterXactCallback(XactCallback callback, void *arg)
    3818             : {
    3819             :     XactCallbackItem *item;
    3820             :     XactCallbackItem *prev;
    3821             : 
    3822           0 :     prev = NULL;
    3823           0 :     for (item = Xact_callbacks; item; prev = item, item = item->next)
    3824             :     {
    3825           0 :         if (item->callback == callback && item->arg == arg)
    3826             :         {
    3827           0 :             if (prev)
    3828           0 :                 prev->next = item->next;
    3829             :             else
    3830           0 :                 Xact_callbacks = item->next;
    3831           0 :             pfree(item);
    3832           0 :             break;
    3833             :         }
    3834             :     }
    3835           0 : }
    3836             : 
    3837             : static void
    3838     1588930 : CallXactCallbacks(XactEvent event)
    3839             : {
    3840             :     XactCallbackItem *item;
    3841             :     XactCallbackItem *next;
    3842             : 
    3843     1882500 :     for (item = Xact_callbacks; item; item = next)
    3844             :     {
    3845             :         /* allow callbacks to unregister themselves when called */
    3846      293572 :         next = item->next;
    3847      293572 :         item->callback(event, item->arg);
    3848             :     }
    3849     1588928 : }
    3850             : 
    3851             : 
    3852             : /*
    3853             :  * Register or deregister callback functions for start- and end-of-subxact
    3854             :  * operations.
    3855             :  *
    3856             :  * Pretty much same as above, but for subtransaction events.
    3857             :  *
    3858             :  * At subtransaction end, the callback occurs post-subcommit or post-subabort,
    3859             :  * so the callback functions can only do noncritical cleanup.  At
    3860             :  * subtransaction start, the callback is called when the subtransaction has
    3861             :  * finished initializing.
    3862             :  */
    3863             : void
    3864        3526 : RegisterSubXactCallback(SubXactCallback callback, void *arg)
    3865             : {
    3866             :     SubXactCallbackItem *item;
    3867             : 
    3868             :     item = (SubXactCallbackItem *)
    3869        3526 :         MemoryContextAlloc(TopMemoryContext, sizeof(SubXactCallbackItem));
    3870        3526 :     item->callback = callback;
    3871        3526 :     item->arg = arg;
    3872        3526 :     item->next = SubXact_callbacks;
    3873        3526 :     SubXact_callbacks = item;
    3874        3526 : }
    3875             : 
    3876             : void
    3877           0 : UnregisterSubXactCallback(SubXactCallback callback, void *arg)
    3878             : {
    3879             :     SubXactCallbackItem *item;
    3880             :     SubXactCallbackItem *prev;
    3881             : 
    3882           0 :     prev = NULL;
    3883           0 :     for (item = SubXact_callbacks; item; prev = item, item = item->next)
    3884             :     {
    3885           0 :         if (item->callback == callback && item->arg == arg)
    3886             :         {
    3887           0 :             if (prev)
    3888           0 :                 prev->next = item->next;
    3889             :             else
    3890           0 :                 SubXact_callbacks = item->next;
    3891           0 :             pfree(item);
    3892           0 :             break;
    3893             :         }
    3894             :     }
    3895           0 : }
    3896             : 
    3897             : static void
    3898       50534 : CallSubXactCallbacks(SubXactEvent event,
    3899             :                      SubTransactionId mySubid,
    3900             :                      SubTransactionId parentSubid)
    3901             : {
    3902             :     SubXactCallbackItem *item;
    3903             :     SubXactCallbackItem *next;
    3904             : 
    3905       90172 :     for (item = SubXact_callbacks; item; item = next)
    3906             :     {
    3907             :         /* allow callbacks to unregister themselves when called */
    3908       39638 :         next = item->next;
    3909       39638 :         item->callback(event, mySubid, parentSubid, item->arg);
    3910             :     }
    3911       50534 : }
    3912             : 
    3913             : 
    3914             : /* ----------------------------------------------------------------
    3915             :  *                     transaction block support
    3916             :  * ----------------------------------------------------------------
    3917             :  */
    3918             : 
    3919             : /*
    3920             :  *  BeginTransactionBlock
    3921             :  *      This executes a BEGIN command.
    3922             :  */
    3923             : void
    3924       16136 : BeginTransactionBlock(void)
    3925             : {
    3926       16136 :     TransactionState s = CurrentTransactionState;
    3927             : 
    3928       16136 :     switch (s->blockState)
    3929             :     {
    3930             :             /*
    3931             :              * We are not inside a transaction block, so allow one to begin.
    3932             :              */
    3933       15172 :         case TBLOCK_STARTED:
    3934       15172 :             s->blockState = TBLOCK_BEGIN;
    3935       15172 :             break;
    3936             : 
    3937             :             /*
    3938             :              * BEGIN converts an implicit transaction block to a regular one.
    3939             :              * (Note that we allow this even if we've already done some
    3940             :              * commands, which is a bit odd but matches historical practice.)
    3941             :              */
    3942         964 :         case TBLOCK_IMPLICIT_INPROGRESS:
    3943         964 :             s->blockState = TBLOCK_BEGIN;
    3944         964 :             break;
    3945             : 
    3946             :             /*
    3947             :              * Already a transaction block in progress.
    3948             :              */
    3949           0 :         case TBLOCK_INPROGRESS:
    3950             :         case TBLOCK_PARALLEL_INPROGRESS:
    3951             :         case TBLOCK_SUBINPROGRESS:
    3952             :         case TBLOCK_ABORT:
    3953             :         case TBLOCK_SUBABORT:
    3954           0 :             ereport(WARNING,
    3955             :                     (errcode(ERRCODE_ACTIVE_SQL_TRANSACTION),
    3956             :                      errmsg("there is already a transaction in progress")));
    3957           0 :             break;
    3958             : 
    3959             :             /* These cases are invalid. */
    3960           0 :         case TBLOCK_DEFAULT:
    3961             :         case TBLOCK_BEGIN:
    3962             :         case TBLOCK_SUBBEGIN:
    3963             :         case TBLOCK_END:
    3964             :         case TBLOCK_SUBRELEASE:
    3965             :         case TBLOCK_SUBCOMMIT:
    3966             :         case TBLOCK_ABORT_END:
    3967             :         case TBLOCK_SUBABORT_END:
    3968             :         case TBLOCK_ABORT_PENDING:
    3969             :         case TBLOCK_SUBABORT_PENDING:
    3970             :         case TBLOCK_SUBRESTART:
    3971             :         case TBLOCK_SUBABORT_RESTART:
    3972             :         case TBLOCK_PREPARE:
    3973           0 :             elog(FATAL, "BeginTransactionBlock: unexpected state %s",
    3974             :                  BlockStateAsString(s->blockState));
    3975             :             break;
    3976             :     }
    3977       16136 : }
    3978             : 
    3979             : /*
    3980             :  *  PrepareTransactionBlock
    3981             :  *      This executes a PREPARE command.
    3982             :  *
    3983             :  * Since PREPARE may actually do a ROLLBACK, the result indicates what
    3984             :  * happened: true for PREPARE, false for ROLLBACK.
    3985             :  *
    3986             :  * Note that we don't actually do anything here except change blockState.
    3987             :  * The real work will be done in the upcoming PrepareTransaction().
    3988             :  * We do it this way because it's not convenient to change memory context,
    3989             :  * resource owner, etc while executing inside a Portal.
    3990             :  */
    3991             : bool
    3992         712 : PrepareTransactionBlock(const char *gid)
    3993             : {
    3994             :     TransactionState s;
    3995             :     bool        result;
    3996             : 
    3997             :     /* Set up to commit the current transaction */
    3998         712 :     result = EndTransactionBlock(false);
    3999             : 
    4000             :     /* If successful, change outer tblock state to PREPARE */
    4001         712 :     if (result)
    4002             :     {
    4003         708 :         s = CurrentTransactionState;
    4004             : 
    4005         962 :         while (s->parent != NULL)
    4006         254 :             s = s->parent;
    4007             : 
    4008         708 :         if (s->blockState == TBLOCK_END)
    4009             :         {
    4010             :             /* Save GID where PrepareTransaction can find it again */
    4011         708 :             prepareGID = MemoryContextStrdup(TopTransactionContext, gid);
    4012             : 
    4013         708 :             s->blockState = TBLOCK_PREPARE;
    4014             :         }
    4015             :         else
    4016             :         {
    4017             :             /*
    4018             :              * ignore case where we are not in a transaction;
    4019             :              * EndTransactionBlock already issued a warning.
    4020             :              */
    4021             :             Assert(s->blockState == TBLOCK_STARTED ||
    4022             :                    s->blockState == TBLOCK_IMPLICIT_INPROGRESS);
    4023             :             /* Don't send back a PREPARE result tag... */
    4024           0 :             result = false;
    4025             :         }
    4026             :     }
    4027             : 
    4028         712 :     return result;
    4029             : }
    4030             : 
    4031             : /*
    4032             :  *  EndTransactionBlock
    4033             :  *      This executes a COMMIT command.
    4034             :  *
    4035             :  * Since COMMIT may actually do a ROLLBACK, the result indicates what
    4036             :  * happened: true for COMMIT, false for ROLLBACK.
    4037             :  *
    4038             :  * Note that we don't actually do anything here except change blockState.
    4039             :  * The real work will be done in the upcoming CommitTransactionCommand().
    4040             :  * We do it this way because it's not convenient to change memory context,
    4041             :  * resource owner, etc while executing inside a Portal.
    4042             :  */
    4043             : bool
    4044       12994 : EndTransactionBlock(bool chain)
    4045             : {
    4046       12994 :     TransactionState s = CurrentTransactionState;
    4047       12994 :     bool        result = false;
    4048             : 
    4049       12994 :     switch (s->blockState)
    4050             :     {
    4051             :             /*
    4052             :              * We are in a transaction block, so tell CommitTransactionCommand
    4053             :              * to COMMIT.
    4054             :              */
    4055       11250 :         case TBLOCK_INPROGRESS:
    4056       11250 :             s->blockState = TBLOCK_END;
    4057       11250 :             result = true;
    4058       11250 :             break;
    4059             : 
    4060             :             /*
    4061             :              * We are in an implicit transaction block.  If AND CHAIN was
    4062             :              * specified, error.  Otherwise commit, but issue a warning
    4063             :              * because there was no explicit BEGIN before this.
    4064             :              */
    4065          48 :         case TBLOCK_IMPLICIT_INPROGRESS:
    4066          48 :             if (chain)
    4067          24 :                 ereport(ERROR,
    4068             :                         (errcode(ERRCODE_NO_ACTIVE_SQL_TRANSACTION),
    4069             :                 /* translator: %s represents an SQL statement name */
    4070             :                          errmsg("%s can only be used in transaction blocks",
    4071             :                                 "COMMIT AND CHAIN")));
    4072             :             else
    4073          24 :                 ereport(WARNING,
    4074             :                         (errcode(ERRCODE_NO_ACTIVE_SQL_TRANSACTION),
    4075             :                          errmsg("there is no transaction in progress")));
    4076          24 :             s->blockState = TBLOCK_END;
    4077          24 :             result = true;
    4078          24 :             break;
    4079             : 
    4080             :             /*
    4081             :              * We are in a failed transaction block.  Tell
    4082             :              * CommitTransactionCommand it's time to exit the block.
    4083             :              */
    4084         706 :         case TBLOCK_ABORT:
    4085         706 :             s->blockState = TBLOCK_ABORT_END;
    4086         706 :             break;
    4087             : 
    4088             :             /*
    4089             :              * We are in a live subtransaction block.  Set up to subcommit all
    4090             :              * open subtransactions and then commit the main transaction.
    4091             :              */
    4092         906 :         case TBLOCK_SUBINPROGRESS:
    4093        1946 :             while (s->parent != NULL)
    4094             :             {
    4095        1040 :                 if (s->blockState == TBLOCK_SUBINPROGRESS)
    4096        1040 :                     s->blockState = TBLOCK_SUBCOMMIT;
    4097             :                 else
    4098           0 :                     elog(FATAL, "EndTransactionBlock: unexpected state %s",
    4099             :                          BlockStateAsString(s->blockState));
    4100        1040 :                 s = s->parent;
    4101             :             }
    4102         906 :             if (s->blockState == TBLOCK_INPROGRESS)
    4103         906 :                 s->blockState = TBLOCK_END;
    4104             :             else
    4105           0 :                 elog(FATAL, "EndTransactionBlock: unexpected state %s",
    4106             :                      BlockStateAsString(s->blockState));
    4107         906 :             result = true;
    4108         906 :             break;
    4109             : 
    4110             :             /*
    4111             :              * Here we are inside an aborted subtransaction.  Treat the COMMIT
    4112             :              * as ROLLBACK: set up to abort everything and exit the main
    4113             :              * transaction.
    4114             :              */
    4115          60 :         case TBLOCK_SUBABORT:
    4116         120 :             while (s->parent != NULL)
    4117             :             {
    4118          60 :                 if (s->blockState == TBLOCK_SUBINPROGRESS)
    4119           0 :                     s->blockState = TBLOCK_SUBABORT_PENDING;
    4120          60 :                 else if (s->blockState == TBLOCK_SUBABORT)
    4121          60 :                     s->blockState = TBLOCK_SUBABORT_END;
    4122             :                 else
    4123           0 :                     elog(FATAL, "EndTransactionBlock: unexpected state %s",
    4124             :                          BlockStateAsString(s->blockState));
    4125          60 :                 s = s->parent;
    4126             :             }
    4127          60 :             if (s->blockState == TBLOCK_INPROGRESS)
    4128          60 :                 s->blockState = TBLOCK_ABORT_PENDING;
    4129           0 :             else if (s->blockState == TBLOCK_ABORT)
    4130           0 :                 s->blockState = TBLOCK_ABORT_END;
    4131             :             else
    4132           0 :                 elog(FATAL, "EndTransactionBlock: unexpected state %s",
    4133             :                      BlockStateAsString(s->blockState));
    4134          60 :             break;
    4135             : 
    4136             :             /*
    4137             :              * The user issued COMMIT when not inside a transaction.  For
    4138             :              * COMMIT without CHAIN, issue a WARNING, staying in
    4139             :              * TBLOCK_STARTED state.  The upcoming call to
    4140             :              * CommitTransactionCommand() will then close the transaction and
    4141             :              * put us back into the default state.  For COMMIT AND CHAIN,
    4142             :              * error.
    4143             :              */
    4144          24 :         case TBLOCK_STARTED:
    4145          24 :             if (chain)
    4146           6 :                 ereport(ERROR,
    4147             :                         (errcode(ERRCODE_NO_ACTIVE_SQL_TRANSACTION),
    4148             :                 /* translator: %s represents an SQL statement name */
    4149             :                          errmsg("%s can only be used in transaction blocks",
    4150             :                                 "COMMIT AND CHAIN")));
    4151             :             else
    4152          18 :                 ereport(WARNING,
    4153             :                         (errcode(ERRCODE_NO_ACTIVE_SQL_TRANSACTION),
    4154             :                          errmsg("there is no transaction in progress")));
    4155          18 :             result = true;
    4156          18 :             break;
    4157             : 
    4158             :             /*
    4159             :              * The user issued a COMMIT that somehow ran inside a parallel
    4160             :              * worker.  We can't cope with that.
    4161             :              */
    4162           0 :         case TBLOCK_PARALLEL_INPROGRESS:
    4163           0 :             ereport(FATAL,
    4164             :                     (errcode(ERRCODE_INVALID_TRANSACTION_STATE),
    4165             :                      errmsg("cannot commit during a parallel operation")));
    4166             :             break;
    4167             : 
    4168             :             /* These cases are invalid. */
    4169           0 :         case TBLOCK_DEFAULT:
    4170             :         case TBLOCK_BEGIN:
    4171             :         case TBLOCK_SUBBEGIN:
    4172             :         case TBLOCK_END:
    4173             :         case TBLOCK_SUBRELEASE:
    4174             :         case TBLOCK_SUBCOMMIT:
    4175             :         case TBLOCK_ABORT_END:
    4176             :         case TBLOCK_SUBABORT_END:
    4177             :         case TBLOCK_ABORT_PENDING:
    4178             :         case TBLOCK_SUBABORT_PENDING:
    4179             :         case TBLOCK_SUBRESTART:
    4180             :         case TBLOCK_SUBABORT_RESTART:
    4181             :         case TBLOCK_PREPARE:
    4182           0 :             elog(FATAL, "EndTransactionBlock: unexpected state %s",
    4183             :                  BlockStateAsString(s->blockState));
    4184             :             break;
    4185             :     }
    4186             : 
    4187       12964 :     Assert(s->blockState == TBLOCK_STARTED ||
    4188             :            s->blockState == TBLOCK_END ||
    4189             :            s->blockState == TBLOCK_ABORT_END ||
    4190             :            s->blockState == TBLOCK_ABORT_PENDING);
    4191             : 
    4192       12964 :     s->chain = chain;
    4193             : 
    4194       12964 :     return result;
    4195             : }
    4196             : 
    4197             : /*
    4198             :  *  UserAbortTransactionBlock
    4199             :  *      This executes a ROLLBACK command.
    4200             :  *
    4201             :  * As above, we don't actually do anything here except change blockState.
    4202             :  */
    4203             : void
    4204        2782 : UserAbortTransactionBlock(bool chain)
    4205             : {
    4206        2782 :     TransactionState s = CurrentTransactionState;
    4207             : 
    4208        2782 :     switch (s->blockState)
    4209             :     {
    4210             :             /*
    4211             :              * We are inside a transaction block and we got a ROLLBACK command
    4212             :              * from the user, so tell CommitTransactionCommand to abort and
    4213             :              * exit the transaction block.
    4214             :              */
    4215        1938 :         case TBLOCK_INPROGRESS:
    4216        1938 :             s->blockState = TBLOCK_ABORT_PENDING;
    4217        1938 :             break;
    4218             : 
    4219             :             /*
    4220             :              * We are inside a failed transaction block and we got a ROLLBACK
    4221             :              * command from the user.  Abort processing is already done, so
    4222             :              * CommitTransactionCommand just has to cleanup and go back to
    4223             :              * idle state.
    4224             :              */
    4225         660 :         case TBLOCK_ABORT:
    4226         660 :             s->blockState = TBLOCK_ABORT_END;
    4227         660 :             break;
    4228             : 
    4229             :             /*
    4230             :              * We are inside a subtransaction.  Mark everything up to top
    4231             :              * level as exitable.
    4232             :              */
    4233         106 :         case TBLOCK_SUBINPROGRESS:
    4234             :         case TBLOCK_SUBABORT:
    4235         424 :             while (s->parent != NULL)
    4236             :             {
    4237         318 :                 if (s->blockState == TBLOCK_SUBINPROGRESS)
    4238         298 :                     s->blockState = TBLOCK_SUBABORT_PENDING;
    4239          20 :                 else if (s->blockState == TBLOCK_SUBABORT)
    4240          20 :                     s->blockState = TBLOCK_SUBABORT_END;
    4241             :                 else
    4242           0 :                     elog(FATAL, "UserAbortTransactionBlock: unexpected state %s",
    4243             :                          BlockStateAsString(s->blockState));
    4244         318 :                 s = s->parent;
    4245             :             }
    4246         106 :             if (s->blockState == TBLOCK_INPROGRESS)
    4247         106 :                 s->blockState = TBLOCK_ABORT_PENDING;
    4248           0 :             else if (s->blockState == TBLOCK_ABORT)
    4249           0 :                 s->blockState = TBLOCK_ABORT_END;
    4250             :             else
    4251           0 :                 elog(FATAL, "UserAbortTransactionBlock: unexpected state %s",
    4252             :                      BlockStateAsString(s->blockState));
    4253         106 :             break;
    4254             : 
    4255             :             /*
    4256             :              * The user issued ABORT when not inside a transaction.  For
    4257             :              * ROLLBACK without CHAIN, issue a WARNING and go to abort state.
    4258             :              * The upcoming call to CommitTransactionCommand() will then put
    4259             :              * us back into the default state.  For ROLLBACK AND CHAIN, error.
    4260             :              *
    4261             :              * We do the same thing with ABORT inside an implicit transaction,
    4262             :              * although in this case we might be rolling back actual database
    4263             :              * state changes.  (It's debatable whether we should issue a
    4264             :              * WARNING in this case, but we have done so historically.)
    4265             :              */
    4266          78 :         case TBLOCK_STARTED:
    4267             :         case TBLOCK_IMPLICIT_INPROGRESS:
    4268          78 :             if (chain)
    4269          30 :                 ereport(ERROR,
    4270             :                         (errcode(ERRCODE_NO_ACTIVE_SQL_TRANSACTION),
    4271             :                 /* translator: %s represents an SQL statement name */
    4272             :                          errmsg("%s can only be used in transaction blocks",
    4273             :                                 "ROLLBACK AND CHAIN")));
    4274             :             else
    4275          48 :                 ereport(WARNING,
    4276             :                         (errcode(ERRCODE_NO_ACTIVE_SQL_TRANSACTION),
    4277             :                          errmsg("there is no transaction in progress")));
    4278          48 :             s->blockState = TBLOCK_ABORT_PENDING;
    4279          48 :             break;
    4280             : 
    4281             :             /*
    4282             :              * The user issued an ABORT that somehow ran inside a parallel
    4283             :              * worker.  We can't cope with that.
    4284             :              */
    4285           0 :         case TBLOCK_PARALLEL_INPROGRESS:
    4286           0 :             ereport(FATAL,
    4287             :                     (errcode(ERRCODE_INVALID_TRANSACTION_STATE),
    4288             :                      errmsg("cannot abort during a parallel operation")));
    4289             :             break;
    4290             : 
    4291             :             /* These cases are invalid. */
    4292           0 :         case TBLOCK_DEFAULT:
    4293             :         case TBLOCK_BEGIN:
    4294             :         case TBLOCK_SUBBEGIN:
    4295             :         case TBLOCK_END:
    4296             :         case TBLOCK_SUBRELEASE:
    4297             :         case TBLOCK_SUBCOMMIT:
    4298             :         case TBLOCK_ABORT_END:
    4299             :         case TBLOCK_SUBABORT_END:
    4300             :         case TBLOCK_ABORT_PENDING:
    4301             :         case TBLOCK_SUBABORT_PENDING:
    4302             :         case TBLOCK_SUBRESTART:
    4303             :         case TBLOCK_SUBABORT_RESTART:
    4304             :         case TBLOCK_PREPARE:
    4305           0 :             elog(FATAL, "UserAbortTransactionBlock: unexpected state %s",
    4306             :                  BlockStateAsString(s->blockState));
    4307             :             break;
    4308             :     }
    4309             : 
    4310        2752 :     Assert(s->blockState == TBLOCK_ABORT_END ||
    4311             :            s->blockState == TBLOCK_ABORT_PENDING);
    4312             : 
    4313        2752 :     s->chain = chain;
    4314        2752 : }
    4315             : 
    4316             : /*
    4317             :  * BeginImplicitTransactionBlock
    4318             :  *      Start an implicit transaction block if we're not already in one.
    4319             :  *
    4320             :  * Unlike BeginTransactionBlock, this is called directly from the main loop
    4321             :  * in postgres.c, not within a Portal.  So we can just change blockState
    4322             :  * without a lot of ceremony.  We do not expect caller to do
    4323             :  * CommitTransactionCommand/StartTransactionCommand.
    4324             :  */
    4325             : void
    4326       86466 : BeginImplicitTransactionBlock(void)
    4327             : {
    4328       86466 :     TransactionState s = CurrentTransactionState;
    4329             : 
    4330             :     /*
    4331             :      * If we are in STARTED state (that is, no transaction block is open),
    4332             :      * switch to IMPLICIT_INPROGRESS state, creating an implicit transaction
    4333             :      * block.
    4334             :      *
    4335             :      * For caller convenience, we consider all other transaction states as
    4336             :      * legal here; otherwise the caller would need its own state check, which
    4337             :      * seems rather pointless.
    4338             :      */
    4339       86466 :     if (s->blockState == TBLOCK_STARTED)
    4340        9990 :         s->blockState = TBLOCK_IMPLICIT_INPROGRESS;
    4341       86466 : }
    4342             : 
    4343             : /*
    4344             :  * EndImplicitTransactionBlock
    4345             :  *      End an implicit transaction block, if we're in one.
    4346             :  *
    4347             :  * Like EndTransactionBlock, we just make any needed blockState change here.
    4348             :  * The real work will be done in the upcoming CommitTransactionCommand().
    4349             :  */
    4350             : void
    4351       35262 : EndImplicitTransactionBlock(void)
    4352             : {
    4353       35262 :     TransactionState s = CurrentTransactionState;
    4354             : 
    4355             :     /*
    4356             :      * If we are in IMPLICIT_INPROGRESS state, switch back to STARTED state,
    4357             :      * allowing CommitTransactionCommand to commit whatever happened during
    4358             :      * the implicit transaction block as though it were a single statement.
    4359             :      *
    4360             :      * For caller convenience, we consider all other transaction states as
    4361             :      * legal here; otherwise the caller would need its own state check, which
    4362             :      * seems rather pointless.
    4363             :      */
    4364       35262 :     if (s->blockState == TBLOCK_IMPLICIT_INPROGRESS)
    4365        8854 :         s->blockState = TBLOCK_STARTED;
    4366       35262 : }
    4367             : 
    4368             : /*
    4369             :  * DefineSavepoint
    4370             :  *      This executes a SAVEPOINT command.
    4371             :  */
    4372             : void
    4373        2648 : DefineSavepoint(const char *name)
    4374             : {
    4375        2648 :     TransactionState s = CurrentTransactionState;
    4376             : 
    4377             :     /*
    4378             :      * Workers synchronize transaction state at the beginning of each parallel
    4379             :      * operation, so we can't account for new subtransactions after that
    4380             :      * point.  (Note that this check will certainly error out if s->blockState
    4381             :      * is TBLOCK_PARALLEL_INPROGRESS, so we can treat that as an invalid case
    4382             :      * below.)
    4383             :      */
    4384        2648 :     if (IsInParallelMode() || IsParallelWorker())
    4385           0 :         ereport(ERROR,
    4386             :                 (errcode(ERRCODE_INVALID_TRANSACTION_STATE),
    4387             :                  errmsg("cannot define savepoints during a parallel operation")));
    4388             : 
    4389        2648 :     switch (s->blockState)
    4390             :     {
    4391        2636 :         case TBLOCK_INPROGRESS:
    4392             :         case TBLOCK_SUBINPROGRESS:
    4393             :             /* Normal subtransaction start */
    4394        2636 :             PushTransaction();
    4395        2636 :             s = CurrentTransactionState;    /* changed by push */
    4396             : 
    4397             :             /*
    4398             :              * Savepoint names, like the TransactionState block itself, live
    4399             :              * in TopTransactionContext.
    4400             :              */
    4401        2636 :             if (name)
    4402        1918 :                 s->name = MemoryContextStrdup(TopTransactionContext, name);
    4403        2636 :             break;
    4404             : 
    4405             :             /*
    4406             :              * We disallow savepoint commands in implicit transaction blocks.
    4407             :              * There would be no great difficulty in allowing them so far as
    4408             :              * this module is concerned, but a savepoint seems inconsistent
    4409             :              * with exec_simple_query's behavior of abandoning the whole query
    4410             :              * string upon error.  Also, the point of an implicit transaction
    4411             :              * block (as opposed to a regular one) is to automatically close
    4412             :              * after an error, so it's hard to see how a savepoint would fit
    4413             :              * into that.
    4414             :              *
    4415             :              * The error messages for this are phrased as if there were no
    4416             :              * active transaction block at all, which is historical but
    4417             :              * perhaps could be improved.
    4418             :              */
    4419          12 :         case TBLOCK_IMPLICIT_INPROGRESS:
    4420          12 :             ereport(ERROR,
    4421             :                     (errcode(ERRCODE_NO_ACTIVE_SQL_TRANSACTION),
    4422             :             /* translator: %s represents an SQL statement name */
    4423             :                      errmsg("%s can only be used in transaction blocks",
    4424             :                             "SAVEPOINT")));
    4425             :             break;
    4426             : 
    4427             :             /* These cases are invalid. */
    4428           0 :         case TBLOCK_DEFAULT:
    4429             :         case TBLOCK_STARTED:
    4430             :         case TBLOCK_BEGIN:
    4431             :         case TBLOCK_PARALLEL_INPROGRESS:
    4432             :         case TBLOCK_SUBBEGIN:
    4433             :         case TBLOCK_END:
    4434             :         case TBLOCK_SUBRELEASE:
    4435             :         case TBLOCK_SUBCOMMIT:
    4436             :         case TBLOCK_ABORT:
    4437             :         case TBLOCK_SUBABORT:
    4438             :         case TBLOCK_ABORT_END:
    4439             :         case TBLOCK_SUBABORT_END:
    4440             :         case TBLOCK_ABORT_PENDING:
    4441             :         case TBLOCK_SUBABORT_PENDING:
    4442             :         case TBLOCK_SUBRESTART:
    4443             :         case TBLOCK_SUBABORT_RESTART:
    4444             :         case TBLOCK_PREPARE:
    4445           0 :             elog(FATAL, "DefineSavepoint: unexpected state %s",
    4446             :                  BlockStateAsString(s->blockState));
    4447             :             break;
    4448             :     }
    4449        2636 : }
    4450             : 
    4451             : /*
    4452             :  * ReleaseSavepoint
    4453             :  *      This executes a RELEASE command.
    4454             :  *
    4455             :  * As above, we don't actually do anything here except change blockState.
    4456             :  */
    4457             : void
    4458         282 : ReleaseSavepoint(const char *name)
    4459             : {
    4460         282 :     TransactionState s = CurrentTransactionState;
    4461             :     TransactionState target,
    4462             :                 xact;
    4463             : 
    4464             :     /*
    4465             :      * Workers synchronize transaction state at the beginning of each parallel
    4466             :      * operation, so we can't account for transaction state change after that
    4467             :      * point.  (Note that this check will certainly error out if s->blockState
    4468             :      * is TBLOCK_PARALLEL_INPROGRESS, so we can treat that as an invalid case
    4469             :      * below.)
    4470             :      */
    4471         282 :     if (IsInParallelMode() || IsParallelWorker())
    4472           0 :         ereport(ERROR,
    4473             :                 (errcode(ERRCODE_INVALID_TRANSACTION_STATE),
    4474             :                  errmsg("cannot release savepoints during a parallel operation")));
    4475             : 
    4476         282 :     switch (s->blockState)
    4477             :     {
    4478             :             /*
    4479             :              * We can't release a savepoint if there is no savepoint defined.
    4480             :              */
    4481           0 :         case TBLOCK_INPROGRESS:
    4482           0 :             ereport(ERROR,
    4483             :                     (errcode(ERRCODE_S_E_INVALID_SPECIFICATION),
    4484             :                      errmsg("savepoint \"%s\" does not exist", name)));
    4485             :             break;
    4486             : 
    4487           6 :         case TBLOCK_IMPLICIT_INPROGRESS:
    4488             :             /* See comment about implicit transactions in DefineSavepoint */
    4489           6 :             ereport(ERROR,
    4490             :                     (errcode(ERRCODE_NO_ACTIVE_SQL_TRANSACTION),
    4491             :             /* translator: %s represents an SQL statement name */
    4492             :                      errmsg("%s can only be used in transaction blocks",
    4493             :                             "RELEASE SAVEPOINT")));
    4494             :             break;
    4495             : 
    4496             :             /*
    4497             :              * We are in a non-aborted subtransaction.  This is the only valid
    4498             :              * case.
    4499             :              */
    4500         276 :         case TBLOCK_SUBINPROGRESS:
    4501         276 :             break;
    4502             : 
    4503             :             /* These cases are invalid. */
    4504           0 :         case TBLOCK_DEFAULT:
    4505             :         case TBLOCK_STARTED:
    4506             :         case TBLOCK_BEGIN:
    4507             :         case TBLOCK_PARALLEL_INPROGRESS:
    4508             :         case TBLOCK_SUBBEGIN:
    4509             :         case TBLOCK_END:
    4510             :         case TBLOCK_SUBRELEASE:
    4511             :         case TBLOCK_SUBCOMMIT:
    4512             :         case TBLOCK_ABORT:
    4513             :         case TBLOCK_SUBABORT:
    4514             :         case TBLOCK_ABORT_END:
    4515             :         case TBLOCK_SUBABORT_END:
    4516             :         case TBLOCK_ABORT_PENDING:
    4517             :         case TBLOCK_SUBABORT_PENDING:
    4518             :         case TBLOCK_SUBRESTART:
    4519             :         case TBLOCK_SUBABORT_RESTART:
    4520             :         case TBLOCK_PREPARE:
    4521           0 :             elog(FATAL, "ReleaseSavepoint: unexpected state %s",
    4522             :                  BlockStateAsString(s->blockState));
    4523             :             break;
    4524             :     }
    4525             : 
    4526         448 :     for (target = s; PointerIsValid(target); target = target->parent)
    4527             :     {
    4528         448 :         if (PointerIsValid(target->name) && strcmp(target->name, name) == 0)
    4529         276 :             break;
    4530             :     }
    4531             : 
    4532         276 :     if (!PointerIsValid(target))
    4533           0 :         ereport(ERROR,
    4534             :                 (errcode(ERRCODE_S_E_INVALID_SPECIFICATION),
    4535             :                  errmsg("savepoint \"%s\" does not exist", name)));
    4536             : 
    4537             :     /* disallow crossing savepoint level boundaries */
    4538         276 :     if (target->savepointLevel != s->savepointLevel)
    4539           0 :         ereport(ERROR,
    4540             :                 (errcode(ERRCODE_S_E_INVALID_SPECIFICATION),
    4541             :                  errmsg("savepoint \"%s\" does not exist within current savepoint level", name)));
    4542             : 
    4543             :     /*
    4544             :      * Mark "commit pending" all subtransactions up to the target
    4545             :      * subtransaction.  The actual commits will happen when control gets to
    4546             :      * CommitTransactionCommand.
    4547             :      */
    4548         276 :     xact = CurrentTransactionState;
    4549             :     for (;;)
    4550             :     {
    4551         172 :         Assert(xact->blockState == TBLOCK_SUBINPROGRESS);
    4552         448 :         xact->blockState = TBLOCK_SUBRELEASE;
    4553         448 :         if (xact == target)
    4554         276 :             break;
    4555         172 :         xact = xact->parent;
    4556             :         Assert(PointerIsValid(xact));
    4557             :     }
    4558         276 : }
    4559             : 
    4560             : /*
    4561             :  * RollbackToSavepoint
    4562             :  *      This executes a ROLLBACK TO <savepoint> command.
    4563             :  *
    4564             :  * As above, we don't actually do anything here except change blockState.
    4565             :  */
    4566             : void
    4567         730 : RollbackToSavepoint(const char *name)
    4568             : {
    4569         730 :     TransactionState s = CurrentTransactionState;
    4570             :     TransactionState target,
    4571             :                 xact;
    4572             : 
    4573             :     /*
    4574             :      * Workers synchronize transaction state at the beginning of each parallel
    4575             :      * operation, so we can't account for transaction state change after that
    4576             :      * point.  (Note that this check will certainly error out if s->blockState
    4577             :      * is TBLOCK_PARALLEL_INPROGRESS, so we can treat that as an invalid case
    4578             :      * below.)
    4579             :      */
    4580         730 :     if (IsInParallelMode() || IsParallelWorker())
    4581           0 :         ereport(ERROR,
    4582             :                 (errcode(ERRCODE_INVALID_TRANSACTION_STATE),
    4583             :                  errmsg("cannot rollback to savepoints during a parallel operation")));
    4584             : 
    4585         730 :     switch (s->blockState)
    4586             :     {
    4587             :             /*
    4588             :              * We can't rollback to a savepoint if there is no savepoint
    4589             :              * defined.
    4590             :              */
    4591           6 :         case TBLOCK_INPROGRESS:
    4592             :         case TBLOCK_ABORT:
    4593           6 :             ereport(ERROR,
    4594             :                     (errcode(ERRCODE_S_E_INVALID_SPECIFICATION),
    4595             :                      errmsg("savepoint \"%s\" does not exist", name)));
    4596             :             break;
    4597             : 
    4598           6 :         case TBLOCK_IMPLICIT_INPROGRESS:
    4599             :             /* See comment about implicit transactions in DefineSavepoint */
    4600           6 :             ereport(ERROR,
    4601             :                     (errcode(ERRCODE_NO_ACTIVE_SQL_TRANSACTION),
    4602             :             /* translator: %s represents an SQL statement name */
    4603             :                      errmsg("%s can only be used in transaction blocks",
    4604             :                             "ROLLBACK TO SAVEPOINT")));
    4605             :             break;
    4606             : 
    4607             :             /*
    4608             :              * There is at least one savepoint, so proceed.
    4609             :              */
    4610         718 :         case TBLOCK_SUBINPROGRESS:
    4611             :         case TBLOCK_SUBABORT:
    4612         718 :             break;
    4613             : 
    4614             :             /* These cases are invalid. */
    4615           0 :         case TBLOCK_DEFAULT:
    4616             :         case TBLOCK_STARTED:
    4617             :         case TBLOCK_BEGIN:
    4618             :         case TBLOCK_PARALLEL_INPROGRESS:
    4619             :         case TBLOCK_SUBBEGIN:
    4620             :         case TBLOCK_END:
    4621             :         case TBLOCK_SUBRELEASE:
    4622             :         case TBLOCK_SUBCOMMIT:
    4623             :         case TBLOCK_ABORT_END:
    4624             :         case TBLOCK_SUBABORT_END:
    4625             :         case TBLOCK_ABORT_PENDING:
    4626             :         case TBLOCK_SUBABORT_PENDING:
    4627             :         case TBLOCK_SUBRESTART:
    4628             :         case TBLOCK_SUBABORT_RESTART:
    4629             :         case TBLOCK_PREPARE:
    4630           0 :             elog(FATAL, "RollbackToSavepoint: unexpected state %s",
    4631             :                  BlockStateAsString(s->blockState));
    4632             :             break;
    4633             :     }
    4634             : 
    4635         770 :     for (target = s; PointerIsValid(target); target = target->parent)
    4636             :     {
    4637         770 :         if (PointerIsValid(target->name) && strcmp(target->name, name) == 0)
    4638         718 :             break;
    4639             :     }
    4640             : 
    4641         718 :     if (!PointerIsValid(target))
    4642           0 :         ereport(ERROR,
    4643             :                 (errcode(ERRCODE_S_E_INVALID_SPECIFICATION),
    4644             :                  errmsg("savepoint \"%s\" does not exist", name)));
    4645             : 
    4646             :     /* disallow crossing savepoint level boundaries */
    4647         718 :     if (target->savepointLevel != s->savepointLevel)
    4648           0 :         ereport(ERROR,
    4649             :                 (errcode(ERRCODE_S_E_INVALID_SPECIFICATION),
    4650             :                  errmsg("savepoint \"%s\" does not exist within current savepoint level", name)));
    4651             : 
    4652             :     /*
    4653             :      * Mark "abort pending" all subtransactions up to the target
    4654             :      * subtransaction.  The actual aborts will happen when control gets to
    4655             :      * CommitTransactionCommand.
    4656             :      */
    4657         718 :     xact = CurrentTransactionState;
    4658             :     for (;;)
    4659             :     {
    4660         770 :         if (xact == target)
    4661         718 :             break;
    4662          52 :         if (xact->blockState == TBLOCK_SUBINPROGRESS)
    4663          52 :             xact->blockState = TBLOCK_SUBABORT_PENDING;
    4664           0 :         else if (xact->blockState == TBLOCK_SUBABORT)
    4665           0 :             xact->blockState = TBLOCK_SUBABORT_END;
    4666             :         else
    4667           0 :             elog(FATAL, "RollbackToSavepoint: unexpected state %s",
    4668             :                  BlockStateAsString(xact->blockState));
    4669          52 :         xact = xact->parent;
    4670             :         Assert(PointerIsValid(xact));
    4671             :     }
    4672             : 
    4673             :     /* And mark the target as "restart pending" */
    4674         718 :     if (xact->blockState == TBLOCK_SUBINPROGRESS)
    4675         520 :         xact->blockState = TBLOCK_SUBRESTART;
    4676         198 :     else if (xact->blockState == TBLOCK_SUBABORT)
    4677         198 :         xact->blockState = TBLOCK_SUBABORT_RESTART;
    4678             :     else
    4679           0 :         elog(FATAL, "RollbackToSavepoint: unexpected state %s",
    4680             :              BlockStateAsString(xact->blockState));
    4681         718 : }
    4682             : 
    4683             : /*
    4684             :  * BeginInternalSubTransaction
    4685             :  *      This is the same as DefineSavepoint except it allows TBLOCK_STARTED,
    4686             :  *      TBLOCK_IMPLICIT_INPROGRESS, TBLOCK_PARALLEL_INPROGRESS, TBLOCK_END,
    4687             :  *      and TBLOCK_PREPARE states, and therefore it can safely be used in
    4688             :  *      functions that might be called when not inside a BEGIN block or when
    4689             :  *      running deferred triggers at COMMIT/PREPARE time.  Also, it
    4690             :  *      automatically does CommitTransactionCommand/StartTransactionCommand
    4691             :  *      instead of expecting the caller to do it.
    4692             :  */
    4693             : void
    4694       17306 : BeginInternalSubTransaction(const char *name)
    4695             : {
    4696       17306 :     TransactionState s = CurrentTransactionState;
    4697       17306 :     bool        save_ExitOnAnyError = ExitOnAnyError;
    4698             : 
    4699             :     /*
    4700             :      * Errors within this function are improbable, but if one does happen we
    4701             :      * force a FATAL exit.  Callers generally aren't prepared to handle losing
    4702             :      * control, and moreover our transaction state is probably corrupted if we
    4703             :      * fail partway through; so an ordinary ERROR longjmp isn't okay.
    4704             :      */
    4705       17306 :     ExitOnAnyError = true;
    4706             : 
    4707             :     /*
    4708             :      * We do not check for parallel mode here.  It's permissible to start and
    4709             :      * end "internal" subtransactions while in parallel mode, so long as no
    4710             :      * new XIDs or command IDs are assigned.  Enforcement of that occurs in
    4711             :      * AssignTransactionId() and CommandCounterIncrement().
    4712             :      */
    4713             : 
    4714       17306 :     switch (s->blockState)
    4715             :     {
    4716       17306 :         case TBLOCK_STARTED:
    4717             :         case TBLOCK_INPROGRESS:
    4718             :         case TBLOCK_IMPLICIT_INPROGRESS:
    4719             :         case TBLOCK_PARALLEL_INPROGRESS:
    4720             :         case TBLOCK_END:
    4721             :         case TBLOCK_PREPARE:
    4722             :         case TBLOCK_SUBINPROGRESS:
    4723             :             /* Normal subtransaction start */
    4724       17306 :             PushTransaction();
    4725       17306 :             s = CurrentTransactionState;    /* changed by push */
    4726             : 
    4727             :             /*
    4728             :              * Savepoint names, like the TransactionState block itself, live
    4729             :              * in TopTransactionContext.
    4730             :              */
    4731       17306 :             if (name)
    4732        1826 :                 s->name = MemoryContextStrdup(TopTransactionContext, name);
    4733       17306 :             break;
    4734             : 
    4735             :             /* These cases are invalid. */
    4736           0 :         case TBLOCK_DEFAULT:
    4737             :         case TBLOCK_BEGIN:
    4738             :         case TBLOCK_SUBBEGIN:
    4739             :         case TBLOCK_SUBRELEASE:
    4740             :         case TBLOCK_SUBCOMMIT:
    4741             :         case TBLOCK_ABORT:
    4742             :         case TBLOCK_SUBABORT:
    4743             :         case TBLOCK_ABORT_END:
    4744             :         case TBLOCK_SUBABORT_END:
    4745             :         case TBLOCK_ABORT_PENDING:
    4746             :         case TBLOCK_SUBABORT_PENDING:
    4747             :         case TBLOCK_SUBRESTART:
    4748             :         case TBLOCK_SUBABORT_RESTART:
    4749           0 :             elog(FATAL, "BeginInternalSubTransaction: unexpected state %s",
    4750             :                  BlockStateAsString(s->blockState));
    4751             :             break;
    4752             :     }
    4753             : 
    4754       17306 :     CommitTransactionCommand();
    4755       17306 :     StartTransactionCommand();
    4756             : 
    4757       17306 :     ExitOnAnyError = save_ExitOnAnyError;
    4758       17306 : }
    4759             : 
    4760             : /*
    4761             :  * ReleaseCurrentSubTransaction
    4762             :  *
    4763             :  * RELEASE (ie, commit) the innermost subtransaction, regardless of its
    4764             :  * savepoint name (if any).
    4765             :  * NB: do NOT use CommitTransactionCommand/StartTransactionCommand with this.
    4766             :  */
    4767             : void
    4768        9162 : ReleaseCurrentSubTransaction(void)
    4769             : {
    4770        9162 :     TransactionState s = CurrentTransactionState;
    4771             : 
    4772             :     /*
    4773             :      * We do not check for parallel mode here.  It's permissible to start and
    4774             :      * end "internal" subtransactions while in parallel mode, so long as no
    4775             :      * new XIDs or command IDs are assigned.
    4776             :      */
    4777             : 
    4778        9162 :     if (s->blockState != TBLOCK_SUBINPROGRESS)
    4779           0 :         elog(ERROR, "ReleaseCurrentSubTransaction: unexpected state %s",
    4780             :              BlockStateAsString(s->blockState));
    4781             :     Assert(s->state == TRANS_INPROGRESS);
    4782        9162 :     MemoryContextSwitchTo(CurTransactionContext);
    4783        9162 :     CommitSubTransaction();
    4784        9162 :     s = CurrentTransactionState;    /* changed by pop */
    4785             :     Assert(s->state == TRANS_INPROGRESS);
    4786        9162 : }
    4787             : 
    4788             : /*
    4789             :  * RollbackAndReleaseCurrentSubTransaction
    4790             :  *
    4791             :  * ROLLBACK and RELEASE (ie, abort) the innermost subtransaction, regardless
    4792             :  * of its savepoint name (if any).
    4793             :  * NB: do NOT use CommitTransactionCommand/StartTransactionCommand with this.
    4794             :  */
    4795             : void
    4796        8144 : RollbackAndReleaseCurrentSubTransaction(void)
    4797             : {
    4798        8144 :     TransactionState s = CurrentTransactionState;
    4799             : 
    4800             :     /*
    4801             :      * We do not check for parallel mode here.  It's permissible to start and
    4802             :      * end "internal" subtransactions while in parallel mode, so long as no
    4803             :      * new XIDs or command IDs are assigned.
    4804             :      */
    4805             : 
    4806        8144 :     switch (s->blockState)
    4807             :     {
    4808             :             /* Must be in a subtransaction */
    4809        8144 :         case TBLOCK_SUBINPROGRESS:
    4810             :         case TBLOCK_SUBABORT:
    4811        8144 :             break;
    4812             : 
    4813             :             /* These cases are invalid. */
    4814           0 :         case TBLOCK_DEFAULT:
    4815             :         case TBLOCK_STARTED:
    4816             :         case TBLOCK_BEGIN:
    4817             :         case TBLOCK_IMPLICIT_INPROGRESS:
    4818             :         case TBLOCK_PARALLEL_INPROGRESS:
    4819             :         case TBLOCK_SUBBEGIN:
    4820             :         case TBLOCK_INPROGRESS:
    4821             :         case TBLOCK_END:
    4822             :         case TBLOCK_SUBRELEASE:
    4823             :         case TBLOCK_SUBCOMMIT:
    4824             :         case TBLOCK_ABORT:
    4825             :         case TBLOCK_ABORT_END:
    4826             :         case TBLOCK_SUBABORT_END:
    4827             :         case TBLOCK_ABORT_PENDING:
    4828             :         case TBLOCK_SUBABORT_PENDING:
    4829             :         case TBLOCK_SUBRESTART:
    4830             :         case TBLOCK_SUBABORT_RESTART:
    4831             :         case TBLOCK_PREPARE:
    4832           0 :             elog(FATAL, "RollbackAndReleaseCurrentSubTransaction: unexpected state %s",
    4833             :                  BlockStateAsString(s->blockState));
    4834             :             break;
    4835             :     }
    4836             : 
    4837             :     /*
    4838             :      * Abort the current subtransaction, if needed.
    4839             :      */
    4840        8144 :     if (s->blockState == TBLOCK_SUBINPROGRESS)
    4841        6318 :         AbortSubTransaction();
    4842             : 
    4843             :     /* And clean it up, too */
    4844        8144 :     CleanupSubTransaction();
    4845             : 
    4846        8144 :     s = CurrentTransactionState;    /* changed by pop */
    4847             :     Assert(s->blockState == TBLOCK_SUBINPROGRESS ||
    4848             :            s->blockState == TBLOCK_INPROGRESS ||
    4849             :            s->blockState == TBLOCK_IMPLICIT_INPROGRESS ||
    4850             :            s->blockState == TBLOCK_PARALLEL_INPROGRESS ||
    4851             :            s->blockState == TBLOCK_STARTED);
    4852        8144 : }
    4853             : 
    4854             : /*
    4855             :  *  AbortOutOfAnyTransaction
    4856             :  *
    4857             :  *  This routine is provided for error recovery purposes.  It aborts any
    4858             :  *  active transaction or transaction block, leaving the system in a known
    4859             :  *  idle state.
    4860             :  */
    4861             : void
    4862       35066 : AbortOutOfAnyTransaction(void)
    4863             : {
    4864       35066 :     TransactionState s = CurrentTransactionState;
    4865             : 
    4866             :     /* Ensure we're not running in a doomed memory context */
    4867       35066 :     AtAbort_Memory();
    4868             : 
    4869             :     /*
    4870             :      * Get out of any transaction or nested transaction
    4871             :      */
    4872             :     do
    4873             :     {
    4874       35066 :         switch (s->blockState)
    4875             :         {
    4876       34118 :             case TBLOCK_DEFAULT:
    4877       34118 :                 if (s->state == TRANS_DEFAULT)
    4878             :                 {
    4879             :                     /* Not in a transaction, do nothing */
    4880             :                 }
    4881             :                 else
    4882             :                 {
    4883             :                     /*
    4884             :                      * We can get here after an error during transaction start
    4885             :                      * (state will be TRANS_START).  Need to clean up the
    4886             :                      * incompletely started transaction.  First, adjust the
    4887             :                      * low-level state to suppress warning message from
    4888             :                      * AbortTransaction.
    4889             :                      */
    4890           0 :                     if (s->state == TRANS_START)
    4891           0 :                         s->state = TRANS_INPROGRESS;
    4892           0 :                     AbortTransaction();
    4893           0 :                     CleanupTransaction();
    4894             :                 }
    4895       34118 :                 break;
    4896         926 :             case TBLOCK_STARTED:
    4897             :             case TBLOCK_BEGIN:
    4898             :             case TBLOCK_INPROGRESS:
    4899             :             case TBLOCK_IMPLICIT_INPROGRESS:
    4900             :             case TBLOCK_PARALLEL_INPROGRESS:
    4901             :             case TBLOCK_END:
    4902             :             case TBLOCK_ABORT_PENDING:
    4903             :             case TBLOCK_PREPARE:
    4904             :                 /* In a transaction, so clean up */
    4905         926 :                 AbortTransaction();
    4906         926 :                 CleanupTransaction();
    4907         926 :                 s->blockState = TBLOCK_DEFAULT;
    4908         926 :                 break;
    4909          22 :             case TBLOCK_ABORT:
    4910             :             case TBLOCK_ABORT_END:
    4911             : 
    4912             :                 /*
    4913             :                  * AbortTransaction is already done, still need Cleanup.
    4914             :                  * However, if we failed partway through running ROLLBACK,
    4915             :                  * there will be an active portal running that command, which
    4916             :                  * we need to shut down before doing CleanupTransaction.
    4917             :                  */
    4918          22 :                 AtAbort_Portals();
    4919          22 :                 CleanupTransaction();
    4920          22 :                 s->blockState = TBLOCK_DEFAULT;
    4921          22 :                 break;
    4922             : 
    4923             :                 /*
    4924             :                  * In a subtransaction, so clean it up and abort parent too
    4925             :                  */
    4926           0 :             case TBLOCK_SUBBEGIN:
    4927             :             case TBLOCK_SUBINPROGRESS:
    4928             :             case TBLOCK_SUBRELEASE:
    4929             :             case TBLOCK_SUBCOMMIT:
    4930             :             case TBLOCK_SUBABORT_PENDING:
    4931             :             case TBLOCK_SUBRESTART:
    4932           0 :                 AbortSubTransaction();
    4933           0 :                 CleanupSubTransaction();
    4934           0 :                 s = CurrentTransactionState;    /* changed by pop */
    4935           0 :                 break;
    4936             : 
    4937           0 :             case TBLOCK_SUBABORT:
    4938             :             case TBLOCK_SUBABORT_END:
    4939             :             case TBLOCK_SUBABORT_RESTART:
    4940             :                 /* As above, but AbortSubTransaction already done */
    4941           0 :                 if (s->curTransactionOwner)
    4942             :                 {
    4943             :                     /* As in TBLOCK_ABORT, might have a live portal to zap */
    4944           0 :                     AtSubAbort_Portals(s->subTransactionId,
    4945           0 :                                        s->parent->subTransactionId,
    4946             :                                        s->curTransactionOwner,
    4947           0 :                                        s->parent->curTransactionOwner);
    4948             :                 }
    4949           0 :                 CleanupSubTransaction();
    4950           0 :                 s = CurrentTransactionState;    /* changed by pop */
    4951           0 :                 break;
    4952             :         }
    4953       35066 :     } while (s->blockState != TBLOCK_DEFAULT);
    4954             : 
    4955             :     /* Should be out of all subxacts now */
    4956             :     Assert(s->parent == NULL);
    4957             : 
    4958             :     /*
    4959             :      * Revert to TopMemoryContext, to ensure we exit in a well-defined state
    4960             :      * whether there were any transactions to close or not.  (Callers that
    4961             :      * don't intend to exit soon should switch to some other context to avoid
    4962             :      * long-term memory leaks.)
    4963             :      */
    4964       35066 :     MemoryContextSwitchTo(TopMemoryContext);
    4965       35066 : }
    4966             : 
    4967             : /*
    4968             :  * IsTransactionBlock --- are we within a transaction block?
    4969             :  */
    4970             : bool
    4971      474022 : IsTransactionBlock(void)
    4972             : {
    4973      474022 :     TransactionState s = CurrentTransactionState;
    4974             : 
    4975      474022 :     if (s->blockState == TBLOCK_DEFAULT || s->blockState == TBLOCK_STARTED)
    4976      351018 :         return false;
    4977             : 
    4978      123004 :     return true;
    4979             : }
    4980             : 
    4981             : /*
    4982             :  * IsTransactionOrTransactionBlock --- are we within either a transaction
    4983             :  * or a transaction block?  (The backend is only really "idle" when this
    4984             :  * returns false.)
    4985             :  *
    4986             :  * This should match up with IsTransactionBlock and IsTransactionState.
    4987             :  */
    4988             : bool
    4989      710804 : IsTransactionOrTransactionBlock(void)
    4990             : {
    4991      710804 :     TransactionState s = CurrentTransactionState;
    4992             : 
    4993      710804 :     if (s->blockState == TBLOCK_DEFAULT)
    4994      546574 :         return false;
    4995             : 
    4996      164230 :     return true;
    4997             : }
    4998             : 
    4999             : /*
    5000             :  * TransactionBlockStatusCode - return status code to send in ReadyForQuery
    5001             :  */
    5002             : char
    5003      638770 : TransactionBlockStatusCode(void)
    5004             : {
    5005      638770 :     TransactionState s = CurrentTransactionState;
    5006             : 
    5007      638770 :     switch (s->blockState)
    5008             :     {
    5009      476328 :         case TBLOCK_DEFAULT:
    5010             :         case TBLOCK_STARTED:
    5011      476328 :             return 'I';         /* idle --- not in transaction */
    5012      160664 :         case TBLOCK_BEGIN:
    5013             :         case TBLOCK_SUBBEGIN:
    5014             :         case TBLOCK_INPROGRESS:
    5015             :         case TBLOCK_IMPLICIT_INPROGRESS:
    5016             :         case TBLOCK_PARALLEL_INPROGRESS:
    5017             :         case TBLOCK_SUBINPROGRESS:
    5018             :         case TBLOCK_END:
    5019             :         case TBLOCK_SUBRELEASE:
    5020             :         case TBLOCK_SUBCOMMIT:
    5021             :         case TBLOCK_PREPARE:
    5022      160664 :             return 'T';         /* in transaction */
    5023        1778 :         case TBLOCK_ABORT:
    5024             :         case TBLOCK_SUBABORT:
    5025             :         case TBLOCK_ABORT_END:
    5026             :         case TBLOCK_SUBABORT_END:
    5027             :         case TBLOCK_ABORT_PENDING:
    5028             :         case TBLOCK_SUBABORT_PENDING:
    5029             :         case TBLOCK_SUBRESTART:
    5030             :         case TBLOCK_SUBABORT_RESTART:
    5031        1778 :             return 'E';         /* in failed transaction */
    5032             :     }
    5033             : 
    5034             :     /* should never get here */
    5035           0 :     elog(FATAL, "invalid transaction block state: %s",
    5036             :          BlockStateAsString(s->blockState));
    5037             :     return 0;                   /* keep compiler quiet */
    5038             : }
    5039             : 
    5040             : /*
    5041             :  * IsSubTransaction
    5042             :  */
    5043             : bool
    5044     1190406 : IsSubTransaction(void)
    5045             : {
    5046     1190406 :     TransactionState s = CurrentTransactionState;
    5047             : 
    5048     1190406 :     if (s->nestingLevel >= 2)
    5049         486 :         return true;
    5050             : 
    5051     1189920 :     return false;
    5052             : }
    5053             : 
    5054             : /*
    5055             :  * StartSubTransaction
    5056             :  *
    5057             :  * If you're wondering why this is separate from PushTransaction: it's because
    5058             :  * we can't conveniently do this stuff right inside DefineSavepoint.  The
    5059             :  * SAVEPOINT utility command will be executed inside a Portal, and if we
    5060             :  * muck with CurrentMemoryContext or CurrentResourceOwner then exit from
    5061             :  * the Portal will undo those settings.  So we make DefineSavepoint just
    5062             :  * push a dummy transaction block, and when control returns to the main
    5063             :  * idle loop, CommitTransactionCommand will be called, and we'll come here
    5064             :  * to finish starting the subtransaction.
    5065             :  */
    5066             : static void
    5067       19942 : StartSubTransaction(void)
    5068             : {
    5069       19942 :     TransactionState s = CurrentTransactionState;
    5070             : 
    5071       19942 :     if (s->state != TRANS_DEFAULT)
    5072           0 :         elog(WARNING, "StartSubTransaction while in %s state",
    5073             :              TransStateAsString(s->state));
    5074             : 
    5075       19942 :     s->state = TRANS_START;
    5076             : 
    5077             :     /*
    5078             :      * Initialize subsystems for new subtransaction
    5079             :      *
    5080             :      * must initialize resource-management stuff first
    5081             :      */
    5082       19942 :     AtSubStart_Memory();
    5083       19942 :     AtSubStart_ResourceOwner();
    5084       19942 :     AfterTriggerBeginSubXact();
    5085             : 
    5086       19942 :     s->state = TRANS_INPROGRESS;
    5087             : 
    5088             :     /*
    5089             :      * Call start-of-subxact callbacks
    5090             :      */
    5091       19942 :     CallSubXactCallbacks(SUBXACT_EVENT_START_SUB, s->subTransactionId,
    5092       19942 :                          s->parent->subTransactionId);
    5093             : 
    5094       19942 :     ShowTransactionState("StartSubTransaction");
    5095       19942 : }
    5096             : 
    5097             : /*
    5098             :  * CommitSubTransaction
    5099             :  *
    5100             :  *  The caller has to make sure to always reassign CurrentTransactionState
    5101             :  *  if it has a local pointer to it after calling this function.
    5102             :  */
    5103             : static void
    5104       10650 : CommitSubTransaction(void)
    5105             : {
    5106       10650 :     TransactionState s = CurrentTransactionState;
    5107             : 
    5108       10650 :     ShowTransactionState("CommitSubTransaction");
    5109             : 
    5110       10650 :     if (s->state != TRANS_INPROGRESS)
    5111           0 :         elog(WARNING, "CommitSubTransaction while in %s state",
    5112             :              TransStateAsString(s->state));
    5113             : 
    5114             :     /* Pre-commit processing goes here */
    5115             : 
    5116       10650 :     CallSubXactCallbacks(SUBXACT_EVENT_PRE_COMMIT_SUB, s->subTransactionId,
    5117       10650 :                          s->parent->subTransactionId);
    5118             : 
    5119             :     /*
    5120             :      * If this subxact has started any unfinished parallel operation, clean up
    5121             :      * its workers and exit parallel mode.  Warn about leaked resources.
    5122             :      */
    5123       10650 :     AtEOSubXact_Parallel(true, s->subTransactionId);
    5124       10650 :     if (s->parallelModeLevel != 0)
    5125             :     {
    5126           0 :         elog(WARNING, "parallelModeLevel is %d not 0 at end of subtransaction",
    5127             :              s->parallelModeLevel);
    5128           0 :         s->parallelModeLevel = 0;
    5129             :     }
    5130             : 
    5131             :     /* Do the actual "commit", such as it is */
    5132       10650 :     s->state = TRANS_COMMIT;
    5133             : 
    5134             :     /* Must CCI to ensure commands of subtransaction are seen as done */
    5135       10650 :     CommandCounterIncrement();
    5136             : 
    5137             :     /*
    5138             :      * Prior to 8.4 we marked subcommit in clog at this point.  We now only
    5139             :      * perform that step, if required, as part of the atomic update of the
    5140             :      * whole transaction tree at top level commit or abort.
    5141             :      */
    5142             : 
    5143             :     /* Post-commit cleanup */
    5144       10650 :     if (FullTransactionIdIsValid(s->fullTransactionId))
    5145        7334 :         AtSubCommit_childXids();
    5146       10650 :     AfterTriggerEndSubXact(true);
    5147       10650 :     AtSubCommit_Portals(s->subTransactionId,
    5148       10650 :                         s->parent->subTransactionId,
    5149       10650 :                         s->parent->nestingLevel,
    5150       10650 :                         s->parent->curTransactionOwner);
    5151       10650 :     AtEOSubXact_LargeObject(true, s->subTransactionId,
    5152       10650 :                             s->parent->subTransactionId);
    5153       10650 :     AtSubCommit_Notify();
    5154             : 
    5155       10650 :     CallSubXactCallbacks(SUBXACT_EVENT_COMMIT_SUB, s->subTransactionId,
    5156       10650 :                          s->parent->subTransactionId);
    5157             : 
    5158       10650 :     ResourceOwnerRelease(s->curTransactionOwner,
    5159             :                          RESOURCE_RELEASE_BEFORE_LOCKS,
    5160             :                          true, false);
    5161       10650 :     AtEOSubXact_RelationCache(true, s->subTransactionId,
    5162       10650 :                               s->parent->subTransactionId);
    5163       10650 :     AtEOSubXact_TypeCache();
    5164       10650 :     AtEOSubXact_Inval(true);
    5165       10650 :     AtSubCommit_smgr();
    5166             : 
    5167             :     /*
    5168             :      * The only lock we actually release here is the subtransaction XID lock.
    5169             :      */
    5170       10650 :     CurrentResourceOwner = s->curTransactionOwner;
    5171       10650 :     if (FullTransactionIdIsValid(s->fullTransactionId))
    5172        7334 :         XactLockTableDelete(XidFromFullTransactionId(s->fullTransactionId));
    5173             : 
    5174             :     /*
    5175             :      * Other locks should get transferred to their parent resource owner.
    5176             :      */
    5177       10650 :     ResourceOwnerRelease(s->curTransactionOwner,
    5178             :                          RESOURCE_RELEASE_LOCKS,
    5179             :                          true, false);
    5180       10650 :     ResourceOwnerRelease(s->curTransactionOwner,
    5181             :                          RESOURCE_RELEASE_AFTER_LOCKS,
    5182             :                          true, false);
    5183             : 
    5184       10650 :     AtEOXact_GUC(true, s->gucNestLevel);
    5185       10650 :     AtEOSubXact_SPI(true, s->subTransactionId);
    5186       10650 :     AtEOSubXact_on_commit_actions(true, s->subTransactionId,
    5187       10650 :                                   s->parent->subTransactionId);
    5188       10650 :     AtEOSubXact_Namespace(true, s->subTransactionId,
    5189       10650 :                           s->parent->subTransactionId);
    5190       10650 :     AtEOSubXact_Files(true, s->subTransactionId,
    5191       10650 :                       s->parent->subTransactionId);
    5192       10650 :     AtEOSubXact_HashTables(true, s->nestingLevel);
    5193       10650 :     AtEOSubXact_PgStat(true, s->nestingLevel);
    5194       10650 :     AtSubCommit_Snapshot(s->nestingLevel);
    5195             : 
    5196             :     /*
    5197             :      * We need to restore the upper transaction's read-only state, in case the
    5198             :      * upper is read-write while the child is read-only; GUC will incorrectly
    5199             :      * think it should leave the child state in place.
    5200             :      */
    5201       10650 :     XactReadOnly = s->prevXactReadOnly;
    5202             : 
    5203       10650 :     CurrentResourceOwner = s->parent->curTransactionOwner;
    5204       10650 :     CurTransactionResourceOwner = s->parent->curTransactionOwner;
    5205       10650 :     ResourceOwnerDelete(s->curTransactionOwner);
    5206       10650 :     s->curTransactionOwner = NULL;
    5207             : 
    5208       10650 :     AtSubCommit_Memory();
    5209             : 
    5210       10650 :     s->state = TRANS_DEFAULT;
    5211             : 
    5212       10650 :     PopTransaction();
    5213       10650 : }
    5214             : 
    5215             : /*
    5216             :  * AbortSubTransaction
    5217             :  */
    5218             : static void
    5219        9292 : AbortSubTransaction(void)
    5220             : {
    5221        9292 :     TransactionState s = CurrentTransactionState;
    5222             : 
    5223             :     /* Prevent cancel/die interrupt while cleaning up */
    5224        9292 :     HOLD_INTERRUPTS();
    5225             : 
    5226             :     /* Make sure we have a valid memory context and resource owner */
    5227        9292 :     AtSubAbort_Memory();
    5228        9292 :     AtSubAbort_ResourceOwner();
    5229             : 
    5230             :     /*
    5231             :      * Release any LW locks we might be holding as quickly as possible.
    5232             :      * (Regular locks, however, must be held till we finish aborting.)
    5233             :      * Releasing LW locks is critical since we might try to grab them again
    5234             :      * while cleaning up!
    5235             :      *
    5236             :      * FIXME This may be incorrect --- Are there some locks we should keep?
    5237             :      * Buffer locks, for example?  I don't think so but I'm not sure.
    5238             :      */
    5239        9292 :     LWLockReleaseAll();
    5240             : 
    5241        9292 :     pgstat_report_wait_end();
    5242        9292 :     pgstat_progress_end_command();
    5243             : 
    5244        9292 :     pgaio_error_cleanup();
    5245             : 
    5246        9292 :     UnlockBuffers();
    5247             : 
    5248             :     /* Reset WAL record construction state */
    5249        9292 :     XLogResetInsertion();
    5250             : 
    5251             :     /* Cancel condition variable sleep */
    5252        9292 :     ConditionVariableCancelSleep();
    5253             : 
    5254             :     /*
    5255             :      * Also clean up any open wait for lock, since the lock manager will choke
    5256             :      * if we try to wait for another lock before doing this.
    5257             :      */
    5258        9292 :     LockErrorCleanup();
    5259             : 
    5260             :     /*
    5261             :      * If any timeout events are still active, make sure the timeout interrupt
    5262             :      * is scheduled.  This covers possible loss of a timeout interrupt due to
    5263             :      * longjmp'ing out of the SIGINT handler (see notes in handle_sig_alarm).
    5264             :      * We delay this till after LockErrorCleanup so that we don't uselessly
    5265             :      * reschedule lock or deadlock check timeouts.
    5266             :      */
    5267        9292 :     reschedule_timeouts();
    5268             : 
    5269             :     /*
    5270             :      * Re-enable signals, in case we got here by longjmp'ing out of a signal
    5271             :      * handler.  We do this fairly early in the sequence so that the timeout
    5272             :      * infrastructure will be functional if needed while aborting.
    5273             :      */
    5274        9292 :     sigprocmask(SIG_SETMASK, &UnBlockSig, NULL);
    5275             : 
    5276             :     /*
    5277             :      * check the current transaction state
    5278             :      */
    5279        9292 :     ShowTransactionState("AbortSubTransaction");
    5280             : 
    5281        9292 :     if (s->state != TRANS_INPROGRESS)
    5282           0 :         elog(WARNING, "AbortSubTransaction while in %s state",
    5283             :              TransStateAsString(s->state));
    5284             : 
    5285        9292 :     s->state = TRANS_ABORT;
    5286             : 
    5287             :     /*
    5288             :      * Reset user ID which might have been changed transiently.  (See notes in
    5289             :      * AbortTransaction.)
    5290             :      */
    5291        9292 :     SetUserIdAndSecContext(s->prevUser, s->prevSecContext);
    5292             : 
    5293             :     /* Forget about any active REINDEX. */
    5294        9292 :     ResetReindexState(s->nestingLevel);
    5295             : 
    5296             :     /* Reset logical streaming state. */
    5297        9292 :     ResetLogicalStreamingState();
    5298             : 
    5299             :     /*
    5300             :      * No need for SnapBuildResetExportedSnapshotState() here, snapshot
    5301             :      * exports are not supported in subtransactions.
    5302             :      */
    5303             : 
    5304             :     /*
    5305             :      * If this subxact has started any unfinished parallel operation, clean up
    5306             :      * its workers and exit parallel mode.  Don't warn about leaked resources.
    5307             :      */
    5308        9292 :     AtEOSubXact_Parallel(false, s->subTransactionId);
    5309        9292 :     s->parallelModeLevel = 0;
    5310             : 
    5311             :     /*
    5312             :      * We can skip all this stuff if the subxact failed before creating a
    5313             :      * ResourceOwner...
    5314             :      */
    5315        9292 :     if (s->curTransactionOwner)
    5316             :     {
    5317        9292 :         AfterTriggerEndSubXact(false);
    5318        9292 :         AtSubAbort_Portals(s->subTransactionId,
    5319        9292 :                            s->parent->subTransactionId,
    5320             :                            s->curTransactionOwner,
    5321        9292 :                            s->parent->curTransactionOwner);
    5322        9292 :         AtEOSubXact_LargeObject(false, s->subTransactionId,
    5323        9292 :                                 s->parent->subTransactionId);
    5324        9292 :         AtSubAbort_Notify();
    5325             : 
    5326             :         /* Advertise the fact that we aborted in pg_xact. */
    5327        9292 :         (void) RecordTransactionAbort(true);
    5328             : 
    5329             :         /* Post-abort cleanup */
    5330        9292 :         if (FullTransactionIdIsValid(s->fullTransactionId))
    5331        1298 :             AtSubAbort_childXids();
    5332             : 
    5333        9292 :         CallSubXactCallbacks(SUBXACT_EVENT_ABORT_SUB, s->subTransactionId,
    5334        9292 :                              s->parent->subTransactionId);
    5335             : 
    5336        9292 :         ResourceOwnerRelease(s->curTransactionOwner,
    5337             :                              RESOURCE_RELEASE_BEFORE_LOCKS,
    5338             :                              false, false);
    5339             : 
    5340        9292 :         AtEOXact_Aio(false);
    5341        9292 :         AtEOSubXact_RelationCache(false, s->subTransactionId,
    5342        9292 :                                   s->parent->subTransactionId);
    5343        9292 :         AtEOSubXact_TypeCache();
    5344        9292 :         AtEOSubXact_Inval(false);
    5345        9292 :         ResourceOwnerRelease(s->curTransactionOwner,
    5346             :                              RESOURCE_RELEASE_LOCKS,
    5347             :                              false, false);
    5348        9292 :         ResourceOwnerRelease(s->curTransactionOwner,
    5349             :                              RESOURCE_RELEASE_AFTER_LOCKS,
    5350             :                              false, false);
    5351        9292 :         AtSubAbort_smgr();
    5352             : 
    5353        9292 :         AtEOXact_GUC(false, s->gucNestLevel);
    5354        9292 :         AtEOSubXact_SPI(false, s->subTransactionId);
    5355        9292 :         AtEOSubXact_on_commit_actions(false, s->subTransactionId,
    5356        9292 :                                       s->parent->subTransactionId);
    5357        9292 :         AtEOSubXact_Namespace(false, s->subTransactionId,
    5358        9292 :                               s->parent->subTransactionId);
    5359        9292 :         AtEOSubXact_Files(false, s->subTransactionId,
    5360        9292 :                           s->parent->subTransactionId);
    5361        9292 :         AtEOSubXact_HashTables(false, s->nestingLevel);
    5362        9292 :         AtEOSubXact_PgStat(false, s->nestingLevel);
    5363        9292 :         AtSubAbort_Snapshot(s->nestingLevel);
    5364             :     }
    5365             : 
    5366             :     /*
    5367             :      * Restore the upper transaction's read-only state, too.  This should be
    5368             :      * redundant with GUC's cleanup but we may as well do it for consistency
    5369             :      * with the commit case.
    5370             :      */
    5371        9292 :     XactReadOnly = s->prevXactReadOnly;
    5372             : 
    5373        9292 :     RESUME_INTERRUPTS();
    5374        9292 : }
    5375             : 
    5376             : /*
    5377             :  * CleanupSubTransaction
    5378             :  *
    5379             :  *  The caller has to make sure to always reassign CurrentTransactionState
    5380             :  *  if it has a local pointer to it after calling this function.
    5381             :  */
    5382             : static void
    5383        9292 : CleanupSubTransaction(void)
    5384             : {
    5385        9292 :     TransactionState s = CurrentTransactionState;
    5386             : 
    5387        9292 :     ShowTransactionState("CleanupSubTransaction");
    5388             : 
    5389        9292 :     if (s->state != TRANS_ABORT)
    5390           0 :         elog(WARNING, "CleanupSubTransaction while in %s state",
    5391             :              TransStateAsString(s->state));
    5392             : 
    5393        9292 :     AtSubCleanup_Portals(s->subTransactionId);
    5394             : 
    5395        9292 :     CurrentResourceOwner = s->parent->curTransactionOwner;
    5396        9292 :     CurTransactionResourceOwner = s->parent->curTransactionOwner;
    5397        9292 :     if (s->curTransactionOwner)
    5398        9292 :         ResourceOwnerDelete(s->curTransactionOwner);
    5399        9292 :     s->curTransactionOwner = NULL;
    5400             : 
    5401        9292 :     AtSubCleanup_Memory();
    5402             : 
    5403        9292 :     s->state = TRANS_DEFAULT;
    5404             : 
    5405        9292 :     PopTransaction();
    5406        9292 : }
    5407             : 
    5408             : /*
    5409             :  * PushTransaction
    5410             :  *      Create transaction state stack entry for a subtransaction
    5411             :  *
    5412             :  *  The caller has to make sure to always reassign CurrentTransactionState
    5413             :  *  if it has a local pointer to it after calling this function.
    5414             :  */
    5415             : static void
    5416       19942 : PushTransaction(void)
    5417             : {
    5418       19942 :     TransactionState p = CurrentTransactionState;
    5419             :     TransactionState s;
    5420             : 
    5421             :     /*
    5422             :      * We keep subtransaction state nodes in TopTransactionContext.
    5423             :      */
    5424             :     s = (TransactionState)
    5425       19942 :         MemoryContextAllocZero(TopTransactionContext,
    5426             :                                sizeof(TransactionStateData));
    5427             : 
    5428             :     /*
    5429             :      * Assign a subtransaction ID, watching out for counter wraparound.
    5430             :      */
    5431       19942 :     currentSubTransactionId += 1;
    5432       19942 :     if (currentSubTransactionId == InvalidSubTransactionId)
    5433             :     {
    5434           0 :         currentSubTransactionId -= 1;
    5435           0 :         pfree(s);
    5436           0 :         ereport(ERROR,
    5437             :                 (errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
    5438             :                  errmsg("cannot have more than 2^32-1 subtransactions in a transaction")));
    5439             :     }
    5440             : 
    5441             :     /*
    5442             :      * We can now stack a minimally valid subtransaction without fear of
    5443             :      * failure.
    5444             :      */
    5445       19942 :     s->fullTransactionId = InvalidFullTransactionId; /* until assigned */
    5446       19942 :     s->subTransactionId = currentSubTransactionId;
    5447       19942 :     s->parent = p;
    5448       19942 :     s->nestingLevel = p->nestingLevel + 1;
    5449       19942 :     s->gucNestLevel = NewGUCNestLevel();
    5450       19942 :     s->savepointLevel = p->savepointLevel;
    5451       19942 :     s->state = TRANS_DEFAULT;
    5452       19942 :     s->blockState = TBLOCK_SUBBEGIN;
    5453       19942 :     GetUserIdAndSecContext(&s->prevUser, &s->prevSecContext);
    5454       19942 :     s->prevXactReadOnly = XactReadOnly;
    5455       19942 :     s->startedInRecovery = p->startedInRecovery;
    5456       19942 :     s->parallelModeLevel = 0;
    5457       19942 :     s->parallelChildXact = (p->parallelModeLevel != 0 || p->parallelChildXact);
    5458       19942 :     s->topXidLogged = false;
    5459             : 
    5460       19942 :     CurrentTransactionState = s;
    5461             : 
    5462             :     /*
    5463             :      * AbortSubTransaction and CleanupSubTransaction have to be able to cope
    5464             :      * with the subtransaction from here on out; in particular they should not
    5465             :      * assume that it necessarily has a transaction context, resource owner,
    5466             :      * or XID.
    5467             :      */
    5468       19942 : }
    5469             : 
    5470             : /*
    5471             :  * PopTransaction
    5472             :  *      Pop back to parent transaction state
    5473             :  *
    5474             :  *  The caller has to make sure to always reassign CurrentTransactionState
    5475             :  *  if it has a local pointer to it after calling this function.
    5476             :  */
    5477             : static void
    5478       19942 : PopTransaction(void)
    5479             : {
    5480       19942 :     TransactionState s = CurrentTransactionState;
    5481             : 
    5482       19942 :     if (s->state != TRANS_DEFAULT)
    5483           0 :         elog(WARNING, "PopTransaction while in %s state",
    5484             :              TransStateAsString(s->state));
    5485             : 
    5486       19942 :     if (s->parent == NULL)
    5487           0 :         elog(FATAL, "PopTransaction with no parent");
    5488             : 
    5489       19942 :     CurrentTransactionState = s->parent;
    5490             : 
    5491             :     /* Let's just make sure CurTransactionContext is good */
    5492       19942 :     CurTransactionContext = s->parent->curTransactionContext;
    5493       19942 :     MemoryContextSwitchTo(CurTransactionContext);
    5494             : 
    5495             :     /* Ditto for ResourceOwner links */
    5496       19942 :     CurTransactionResourceOwner = s->parent->curTransactionOwner;
    5497       19942 :     CurrentResourceOwner = s->parent->curTransactionOwner;
    5498             : 
    5499             :     /* Free the old child structure */
    5500       19942 :     if (s->name)
    5501        3744 :         pfree(s->name);
    5502       19942 :     pfree(s);
    5503       19942 : }
    5504             : 
    5505             : /*
    5506             :  * EstimateTransactionStateSpace
    5507             :  *      Estimate the amount of space that will be needed by
    5508             :  *      SerializeTransactionState.  It would be OK to overestimate slightly,
    5509             :  *      but it's simple for us to work out the precise value, so we do.
    5510             :  */
    5511             : Size
    5512         910 : EstimateTransactionStateSpace(void)
    5513             : {
    5514             :     TransactionState s;
    5515         910 :     Size        nxids = 0;
    5516         910 :     Size        size = SerializedTransactionStateHeaderSize;
    5517             : 
    5518        4358 :     for (s = CurrentTransactionState; s != NULL; s = s->parent)
    5519             :     {
    5520        3448 :         if (FullTransactionIdIsValid(s->fullTransactionId))
    5521        1976 :             nxids = add_size(nxids, 1);
    5522        3448 :         nxids = add_size(nxids, s->nChildXids);
    5523             :     }
    5524             : 
    5525         910 :     return add_size(size, mul_size(sizeof(TransactionId), nxids));
    5526             : }
    5527             : 
    5528             : /*
    5529             :  * SerializeTransactionState
    5530             :  *      Write out relevant details of our transaction state that will be
    5531             :  *      needed by a parallel worker.
    5532             :  *
    5533             :  * We need to save and restore XactDeferrable, XactIsoLevel, and the XIDs
    5534             :  * associated with this transaction.  These are serialized into a
    5535             :  * caller-supplied buffer big enough to hold the number of bytes reported by
    5536             :  * EstimateTransactionStateSpace().  We emit the XIDs in sorted order for the
    5537             :  * convenience of the receiving process.
    5538             :  */
    5539             : void
    5540         910 : SerializeTransactionState(Size maxsize, char *start_address)
    5541             : {
    5542             :     TransactionState s;
    5543         910 :     Size        nxids = 0;
    5544         910 :     Size        i = 0;
    5545             :     TransactionId *workspace;
    5546             :     SerializedTransactionState *result;
    5547             : 
    5548         910 :     result = (SerializedTransactionState *) start_address;
    5549             : 
    5550         910 :     result->xactIsoLevel = XactIsoLevel;
    5551         910 :     result->xactDeferrable = XactDeferrable;
    5552         910 :     result->topFullTransactionId = XactTopFullTransactionId;
    5553         910 :     result->currentFullTransactionId =
    5554         910 :         CurrentTransactionState->fullTransactionId;
    5555         910 :     result->currentCommandId = currentCommandId;
    5556             : 
    5557             :     /*
    5558             :      * If we're running in a parallel worker and launching a parallel worker
    5559             :      * of our own, we can just pass along the information that was passed to
    5560             :      * us.
    5561             :      */
    5562         910 :     if (nParallelCurrentXids > 0)
    5563             :     {
    5564           0 :         result->nParallelCurrentXids = nParallelCurrentXids;
    5565           0 :         memcpy(&result->parallelCurrentXids[0], ParallelCurrentXids,
    5566             :                nParallelCurrentXids * sizeof(TransactionId));
    5567           0 :         return;
    5568             :     }
    5569             : 
    5570             :     /*
    5571             :      * OK, we need to generate a sorted list of XIDs that our workers should
    5572             :      * view as current.  First, figure out how many there are.
    5573             :      */
    5574        4358 :     for (s = CurrentTransactionState; s != NULL; s = s->parent)
    5575             :     {
    5576        3448 :         if (FullTransactionIdIsValid(s->fullTransactionId))
    5577        1976 :             nxids = add_size(nxids, 1);
    5578        3448 :         nxids = add_size(nxids, s->nChildXids);
    5579             :     }
    5580             :     Assert(SerializedTransactionStateHeaderSize + nxids * sizeof(TransactionId)
    5581             :            <= maxsize);
    5582             : 
    5583             :     /* Copy them to our scratch space. */
    5584         910 :     workspace = palloc(nxids * sizeof(TransactionId));
    5585        4358 :     for (s = CurrentTransactionState; s != NULL; s = s->parent)
    5586             :     {
    5587        3448 :         if (FullTransactionIdIsValid(s->fullTransactionId))
    5588        1976 :             workspace[i++] = XidFromFullTransactionId(s->fullTransactionId);
    5589        3448 :         if (s->nChildXids > 0)
    5590           0 :             memcpy(&workspace[i], s->childXids,
    5591           0 :                    s->nChildXids * sizeof(TransactionId));
    5592        3448 :         i += s->nChildXids;
    5593             :     }
    5594             :     Assert(i == nxids);
    5595             : 
    5596             :     /* Sort them. */
    5597         910 :     qsort(workspace, nxids, sizeof(TransactionId), xidComparator);
    5598             : 
    5599             :     /* Copy data into output area. */
    5600         910 :     result->nParallelCurrentXids = nxids;
    5601         910 :     memcpy(&result->parallelCurrentXids[0], workspace,
    5602             :            nxids * sizeof(TransactionId));
    5603             : }
    5604             : 
    5605             : /*
    5606             :  * StartParallelWorkerTransaction
    5607             :  *      Start a parallel worker transaction, restoring the relevant
    5608             :  *      transaction state serialized by SerializeTransactionState.
    5609             :  */
    5610             : void
    5611        2746 : StartParallelWorkerTransaction(char *tstatespace)
    5612             : {
    5613             :     SerializedTransactionState *tstate;
    5614             : 
    5615             :     Assert(CurrentTransactionState->blockState == TBLOCK_DEFAULT);
    5616        2746 :     StartTransaction();
    5617             : 
    5618        2746 :     tstate = (SerializedTransactionState *) tstatespace;
    5619        2746 :     XactIsoLevel = tstate->xactIsoLevel;
    5620        2746 :     XactDeferrable = tstate->xactDeferrable;
    5621        2746 :     XactTopFullTransactionId = tstate->topFullTransactionId;
    5622        2746 :     CurrentTransactionState->fullTransactionId =
    5623             :         tstate->currentFullTransactionId;
    5624        2746 :     currentCommandId = tstate->currentCommandId;
    5625        2746 :     nParallelCurrentXids = tstate->nParallelCurrentXids;
    5626        2746 :     ParallelCurrentXids = &tstate->parallelCurrentXids[0];
    5627             : 
    5628        2746 :     CurrentTransactionState->blockState = TBLOCK_PARALLEL_INPROGRESS;
    5629        2746 : }
    5630             : 
    5631             : /*
    5632             :  * EndParallelWorkerTransaction
    5633             :  *      End a parallel worker transaction.
    5634             :  */
    5635             : void
    5636        2734 : EndParallelWorkerTransaction(void)
    5637             : {
    5638             :     Assert(CurrentTransactionState->blockState == TBLOCK_PARALLEL_INPROGRESS);
    5639        2734 :     CommitTransaction();
    5640        2734 :     CurrentTransactionState->blockState = TBLOCK_DEFAULT;
    5641        2734 : }
    5642             : 
    5643             : /*
    5644             :  * ShowTransactionState
    5645             :  *      Debug support
    5646             :  */
    5647             : static void
    5648     1638260 : ShowTransactionState(const char *str)
    5649             : {
    5650             :     /* skip work if message will definitely not be printed */
    5651     1638260 :     if (message_level_is_interesting(DEBUG5))
    5652           0 :         ShowTransactionStateRec(str, CurrentTransactionState);
    5653     1638260 : }
    5654             : 
    5655             : /*
    5656             :  * ShowTransactionStateRec
    5657             :  *      Recursive subroutine for ShowTransactionState
    5658             :  */
    5659             : static void
    5660           0 : ShowTransactionStateRec(const char *str, TransactionState s)
    5661             : {
    5662             :     StringInfoData buf;
    5663             : 
    5664           0 :     if (s->parent)
    5665             :     {
    5666             :         /*
    5667             :          * Since this function recurses, it could be driven to stack overflow.
    5668             :          * This is just a debugging aid, so we can leave out some details
    5669             :          * instead of erroring out with check_stack_depth().
    5670             :          */
    5671           0 :         if (stack_is_too_deep())
    5672           0 :             ereport(DEBUG5,
    5673             :                     (errmsg_internal("%s(%d): parent omitted to avoid stack overflow",
    5674             :                                      str, s->nestingLevel)));
    5675             :         else
    5676           0 :             ShowTransactionStateRec(str, s->parent);
    5677             :     }
    5678             : 
    5679           0 :     initStringInfo(&buf);
    5680           0 :     if (s->nChildXids > 0)
    5681             :     {
    5682             :         int         i;
    5683             : 
    5684           0 :         appendStringInfo(&buf, ", children: %u", s->childXids[0]);
    5685           0 :         for (i = 1; i < s->nChildXids; i++)
    5686           0 :             appendStringInfo(&buf, " %u", s->childXids[i]);
    5687             :     }
    5688           0 :     ereport(DEBUG5,
    5689             :             (errmsg_internal("%s(%d) name: %s; blockState: %s; state: %s, xid/subid/cid: %u/%u/%u%s%s",
    5690             :                              str, s->nestingLevel,
    5691             :                              PointerIsValid(s->name) ? s->name : "unnamed",
    5692             :                              BlockStateAsString(s->blockState),
    5693             :                              TransStateAsString(s->state),
    5694             :                              (unsigned int) XidFromFullTransactionId(s->fullTransactionId),
    5695             :                              (unsigned int) s->subTransactionId,
    5696             :                              (unsigned int) currentCommandId,
    5697             :                              currentCommandIdUsed ? " (used)" : "",
    5698             :                              buf.data)));
    5699           0 :     pfree(buf.data);
    5700           0 : }
    5701             : 
    5702             : /*
    5703             :  * BlockStateAsString
    5704             :  *      Debug support
    5705             :  */
    5706             : static const char *
    5707           0 : BlockStateAsString(TBlockState blockState)
    5708             : {
    5709           0 :     switch (blockState)
    5710             :     {
    5711           0 :         case TBLOCK_DEFAULT:
    5712           0 :             return "DEFAULT";
    5713           0 :         case TBLOCK_STARTED:
    5714           0 :             return "STARTED";
    5715           0 :         case TBLOCK_BEGIN:
    5716           0 :             return "BEGIN";
    5717           0 :         case TBLOCK_INPROGRESS:
    5718           0 :             return "INPROGRESS";
    5719           0 :         case TBLOCK_IMPLICIT_INPROGRESS:
    5720           0 :             return "IMPLICIT_INPROGRESS";
    5721           0 :         case TBLOCK_PARALLEL_INPROGRESS:
    5722           0 :             return "PARALLEL_INPROGRESS";
    5723           0 :         case TBLOCK_END:
    5724           0 :             return "END";
    5725           0 :         case TBLOCK_ABORT:
    5726           0 :             return "ABORT";
    5727           0 :         case TBLOCK_ABORT_END:
    5728           0 :             return "ABORT_END";
    5729           0 :         case TBLOCK_ABORT_PENDING:
    5730           0 :             return "ABORT_PENDING";
    5731           0 :         case TBLOCK_PREPARE:
    5732           0 :             return "PREPARE";
    5733           0 :         case TBLOCK_SUBBEGIN:
    5734           0 :             return "SUBBEGIN";
    5735           0 :         case TBLOCK_SUBINPROGRESS:
    5736           0 :             return "SUBINPROGRESS";
    5737           0 :         case TBLOCK_SUBRELEASE:
    5738           0 :             return "SUBRELEASE";
    5739           0 :         case TBLOCK_SUBCOMMIT:
    5740           0 :             return "SUBCOMMIT";
    5741           0 :         case TBLOCK_SUBABORT:
    5742           0 :             return "SUBABORT";
    5743           0 :         case TBLOCK_SUBABORT_END:
    5744           0 :             return "SUBABORT_END";
    5745           0 :         case TBLOCK_SUBABORT_PENDING:
    5746           0 :             return "SUBABORT_PENDING";
    5747           0 :         case TBLOCK_SUBRESTART:
    5748           0 :             return "SUBRESTART";
    5749           0 :         case TBLOCK_SUBABORT_RESTART:
    5750           0 :             return "SUBABORT_RESTART";
    5751             :     }
    5752           0 :     return "UNRECOGNIZED";
    5753             : }
    5754             : 
    5755             : /*
    5756             :  * TransStateAsString
    5757             :  *      Debug support
    5758             :  */
    5759             : static const char *
    5760           0 : TransStateAsString(TransState state)
    5761             : {
    5762           0 :     switch (state)
    5763             :     {
    5764           0 :         case TRANS_DEFAULT:
    5765           0 :             return "DEFAULT";
    5766           0 :         case TRANS_START:
    5767           0 :             return "START";
    5768           0 :         case TRANS_INPROGRESS:
    5769           0 :             return "INPROGRESS";
    5770           0 :         case TRANS_COMMIT:
    5771           0 :             return "COMMIT";
    5772           0 :         case TRANS_ABORT:
    5773           0 :             return "ABORT";
    5774           0 :         case TRANS_PREPARE:
    5775           0 :             return "PREPARE";
    5776             :     }
    5777           0 :     return "UNRECOGNIZED";
    5778             : }
    5779             : 
    5780             : /*
    5781             :  * xactGetCommittedChildren
    5782             :  *
    5783             :  * Gets the list of committed children of the current transaction.  The return
    5784             :  * value is the number of child transactions.  *ptr is set to point to an
    5785             :  * array of TransactionIds.  The array is allocated in TopTransactionContext;
    5786             :  * the caller should *not* pfree() it (this is a change from pre-8.4 code!).
    5787             :  * If there are no subxacts, *ptr is set to NULL.
    5788             :  */
    5789             : int
    5790      778912 : xactGetCommittedChildren(TransactionId **ptr)
    5791             : {
    5792      778912 :     TransactionState s = CurrentTransactionState;
    5793             : 
    5794      778912 :     if (s->nChildXids == 0)
    5795      777746 :         *ptr = NULL;
    5796             :     else
    5797        1166 :         *ptr = s->childXids;
    5798             : 
    5799      778912 :     return s->nChildXids;
    5800             : }
    5801             : 
    5802             : /*
    5803             :  *  XLOG support routines
    5804             :  */
    5805             : 
    5806             : 
    5807             : /*
    5808             :  * Log the commit record for a plain or twophase transaction commit.
    5809             :  *
    5810             :  * A 2pc commit will be emitted when twophase_xid is valid, a plain one
    5811             :  * otherwise.
    5812             :  */
    5813             : XLogRecPtr
    5814      239662 : XactLogCommitRecord(TimestampTz commit_time,
    5815             :                     int nsubxacts, TransactionId *subxacts,
    5816             :                     int nrels, RelFileLocator *rels,
    5817             :                     int ndroppedstats, xl_xact_stats_item *droppedstats,
    5818             :                     int nmsgs, SharedInvalidationMessage *msgs,
    5819             :                     bool relcacheInval,
    5820             :                     int xactflags, TransactionId twophase_xid,
    5821             :                     const char *twophase_gid)
    5822             : {
    5823             :     xl_xact_commit xlrec;
    5824             :     xl_xact_xinfo xl_xinfo;
    5825             :     xl_xact_dbinfo xl_dbinfo;
    5826             :     xl_xact_subxacts xl_subxacts;
    5827             :     xl_xact_relfilelocators xl_relfilelocators;
    5828             :     xl_xact_stats_items xl_dropped_stats;
    5829             :     xl_xact_invals xl_invals;
    5830             :     xl_xact_twophase xl_twophase;
    5831             :     xl_xact_origin xl_origin;
    5832             :     uint8       info;
    5833             : 
    5834             :     Assert(CritSectionCount > 0);
    5835             : 
    5836      239662 :     xl_xinfo.xinfo = 0;
    5837             : 
    5838             :     /* decide between a plain and 2pc commit */
    5839      239662 :     if (!TransactionIdIsValid(twophase_xid))
    5840      239118 :         info = XLOG_XACT_COMMIT;
    5841             :     else
    5842         544 :         info = XLOG_XACT_COMMIT_PREPARED;
    5843             : 
    5844             :     /* First figure out and collect all the information needed */
    5845             : 
    5846      239662 :     xlrec.xact_time = commit_time;
    5847             : 
    5848      239662 :     if (relcacheInval)
    5849        6702 :         xl_xinfo.xinfo |= XACT_COMPLETION_UPDATE_RELCACHE_FILE;
    5850      239662 :     if (forceSyncCommit)
    5851         938 :         xl_xinfo.xinfo |= XACT_COMPLETION_FORCE_SYNC_COMMIT;
    5852      239662 :     if ((xactflags & XACT_FLAGS_ACQUIREDACCESSEXCLUSIVELOCK))
    5853       71672 :         xl_xinfo.xinfo |= XACT_XINFO_HAS_AE_LOCKS;
    5854             : 
    5855             :     /*
    5856             :      * Check if the caller would like to ask standbys for immediate feedback
    5857             :      * once this commit is applied.
    5858             :      */
    5859      239662 :     if (synchronous_commit >= SYNCHRONOUS_COMMIT_REMOTE_APPLY)
    5860           4 :         xl_xinfo.xinfo |= XACT_COMPLETION_APPLY_FEEDBACK;
    5861             : 
    5862             :     /*
    5863             :      * Relcache invalidations requires information about the current database
    5864             :      * and so does logical decoding.
    5865             :      */
    5866      239662 :     if (nmsgs > 0 || XLogLogicalInfoActive())
    5867             :     {
    5868      140300 :         xl_xinfo.xinfo |= XACT_XINFO_HAS_DBINFO;
    5869      140300 :         xl_dbinfo.dbId = MyDatabaseId;
    5870      140300 :         xl_dbinfo.tsId = MyDatabaseTableSpace;
    5871             :     }
    5872             : 
    5873      239662 :     if (nsubxacts > 0)
    5874             :     {
    5875         976 :         xl_xinfo.xinfo |= XACT_XINFO_HAS_SUBXACTS;
    5876         976 :         xl_subxacts.nsubxacts = nsubxacts;
    5877             :     }
    5878             : 
    5879      239662 :     if (nrels > 0)
    5880             :     {
    5881       18212 :         xl_xinfo.xinfo |= XACT_XINFO_HAS_RELFILELOCATORS;
    5882       18212 :         xl_relfilelocators.nrels = nrels;
    5883       18212 :         info |= XLR_SPECIAL_REL_UPDATE;
    5884             :     }
    5885             : 
    5886      239662 :     if (ndroppedstats > 0)
    5887             :     {
    5888       21024 :         xl_xinfo.xinfo |= XACT_XINFO_HAS_DROPPED_STATS;
    5889       21024 :         xl_dropped_stats.nitems = ndroppedstats;
    5890             :     }
    5891             : 
    5892      239662 :     if (nmsgs > 0)
    5893             :     {
    5894      138624 :         xl_xinfo.xinfo |= XACT_XINFO_HAS_INVALS;
    5895      138624 :         xl_invals.nmsgs = nmsgs;
    5896             :     }
    5897             : 
    5898      239662 :     if (TransactionIdIsValid(twophase_xid))
    5899             :     {
    5900         544 :         xl_xinfo.xinfo |= XACT_XINFO_HAS_TWOPHASE;
    5901         544 :         xl_twophase.xid = twophase_xid;
    5902             :         Assert(twophase_gid != NULL);
    5903             : 
    5904         544 :         if (XLogLogicalInfoActive())
    5905          74 :             xl_xinfo.xinfo |= XACT_XINFO_HAS_GID;
    5906             :     }
    5907             : 
    5908             :     /* dump transaction origin information */
    5909      239662 :     if (replorigin_session_origin != InvalidRepOriginId)
    5910             :     {
    5911        2030 :         xl_xinfo.xinfo |= XACT_XINFO_HAS_ORIGIN;
    5912             : 
    5913        2030 :         xl_origin.origin_lsn = replorigin_session_origin_lsn;
    5914        2030 :         xl_origin.origin_timestamp = replorigin_session_origin_timestamp;
    5915             :     }
    5916             : 
    5917      239662 :     if (xl_xinfo.xinfo != 0)
    5918      151342 :         info |= XLOG_XACT_HAS_INFO;
    5919             : 
    5920             :     /* Then include all the collected data into the commit record. */
    5921             : 
    5922      239662 :     XLogBeginInsert();
    5923             : 
    5924      239662 :     XLogRegisterData(&xlrec, sizeof(xl_xact_commit));
    5925             : 
    5926      239662 :     if (xl_xinfo.xinfo != 0)
    5927      151342 :         XLogRegisterData(&xl_xinfo.xinfo, sizeof(xl_xinfo.xinfo));
    5928             : 
    5929      239662 :     if (xl_xinfo.xinfo & XACT_XINFO_HAS_DBINFO)
    5930      140300 :         XLogRegisterData(&xl_dbinfo, sizeof(xl_dbinfo));
    5931             : 
    5932      239662 :     if (xl_xinfo.xinfo & XACT_XINFO_HAS_SUBXACTS)
    5933             :     {
    5934         976 :         XLogRegisterData(&xl_subxacts,
    5935             :                          MinSizeOfXactSubxacts);
    5936         976 :         XLogRegisterData(subxacts,
    5937             :                          nsubxacts * sizeof(TransactionId));
    5938             :     }
    5939             : 
    5940      239662 :     if (xl_xinfo.xinfo & XACT_XINFO_HAS_RELFILELOCATORS)
    5941             :     {
    5942       18212 :         XLogRegisterData(&xl_relfilelocators,
    5943             :                          MinSizeOfXactRelfileLocators);
    5944       18212 :         XLogRegisterData(rels,
    5945             :                          nrels * sizeof(RelFileLocator));
    5946             :     }
    5947             : 
    5948      239662 :     if (xl_xinfo.xinfo & XACT_XINFO_HAS_DROPPED_STATS)
    5949             :     {
    5950       21024 :         XLogRegisterData(&xl_dropped_stats,
    5951             :                          MinSizeOfXactStatsItems);
    5952       21024 :         XLogRegisterData(droppedstats,
    5953             :                          ndroppedstats * sizeof(xl_xact_stats_item));
    5954             :     }
    5955             : 
    5956      239662 :     if (xl_xinfo.xinfo & XACT_XINFO_HAS_INVALS)
    5957             :     {
    5958      138624 :         XLogRegisterData(&xl_invals, MinSizeOfXactInvals);
    5959      138624 :         XLogRegisterData(msgs,
    5960             :                          nmsgs * sizeof(SharedInvalidationMessage));
    5961             :     }
    5962             : 
    5963      239662 :     if (xl_xinfo.xinfo & XACT_XINFO_HAS_TWOPHASE)
    5964             :     {
    5965         544 :         XLogRegisterData(&xl_twophase, sizeof(xl_xact_twophase));
    5966         544 :         if (xl_xinfo.xinfo & XACT_XINFO_HAS_GID)
    5967          74 :             XLogRegisterData(twophase_gid, strlen(twophase_gid) + 1);
    5968             :     }
    5969             : 
    5970      239662 :     if (xl_xinfo.xinfo & XACT_XINFO_HAS_ORIGIN)
    5971        2030 :         XLogRegisterData(&xl_origin, sizeof(xl_xact_origin));
    5972             : 
    5973             :     /* we allow filtering by xacts */
    5974      239662 :     XLogSetRecordFlags(XLOG_INCLUDE_ORIGIN);
    5975             : 
    5976      239662 :     return XLogInsert(RM_XACT_ID, info);
    5977             : }
    5978             : 
    5979             : /*
    5980             :  * Log the commit record for a plain or twophase transaction abort.
    5981             :  *
    5982             :  * A 2pc abort will be emitted when twophase_xid is valid, a plain one
    5983             :  * otherwise.
    5984             :  */
    5985             : XLogRecPtr
    5986       11620 : XactLogAbortRecord(TimestampTz abort_time,
    5987             :                    int nsubxacts, TransactionId *subxacts,
    5988             :                    int nrels, RelFileLocator *rels,
    5989             :                    int ndroppedstats, xl_xact_stats_item *droppedstats,
    5990             :                    int xactflags, TransactionId twophase_xid,
    5991             :                    const char *twophase_gid)
    5992             : {
    5993             :     xl_xact_abort xlrec;
    5994             :     xl_xact_xinfo xl_xinfo;
    5995             :     xl_xact_subxacts xl_subxacts;
    5996             :     xl_xact_relfilelocators xl_relfilelocators;
    5997             :     xl_xact_stats_items xl_dropped_stats;
    5998             :     xl_xact_twophase xl_twophase;
    5999             :     xl_xact_dbinfo xl_dbinfo;
    6000             :     xl_xact_origin xl_origin;
    6001             : 
    6002             :     uint8       info;
    6003             : 
    6004             :     Assert(CritSectionCount > 0);
    6005             : 
    6006       11620 :     xl_xinfo.xinfo = 0;
    6007             : 
    6008             :     /* decide between a plain and 2pc abort */
    6009       11620 :     if (!TransactionIdIsValid(twophase_xid))
    6010       11540 :         info = XLOG_XACT_ABORT;
    6011             :     else
    6012          80 :         info = XLOG_XACT_ABORT_PREPARED;
    6013             : 
    6014             : 
    6015             :     /* First figure out and collect all the information needed */
    6016             : 
    6017       11620 :     xlrec.xact_time = abort_time;
    6018             : 
    6019       11620 :     if ((xactflags & XACT_FLAGS_ACQUIREDACCESSEXCLUSIVELOCK))
    6020        4748 :         xl_xinfo.xinfo |= XACT_XINFO_HAS_AE_LOCKS;
    6021             : 
    6022       11620 :     if (nsubxacts > 0)
    6023             :     {
    6024         202 :         xl_xinfo.xinfo |= XACT_XINFO_HAS_SUBXACTS;
    6025         202 :         xl_subxacts.nsubxacts = nsubxacts;
    6026             :     }
    6027             : 
    6028       11620 :     if (nrels > 0)
    6029             :     {
    6030        1944 :         xl_xinfo.xinfo |= XACT_XINFO_HAS_RELFILELOCATORS;
    6031        1944 :         xl_relfilelocators.nrels = nrels;
    6032        1944 :         info |= XLR_SPECIAL_REL_UPDATE;
    6033             :     }
    6034             : 
    6035       11620 :     if (ndroppedstats > 0)
    6036             :     {
    6037        2656 :         xl_xinfo.xinfo |= XACT_XINFO_HAS_DROPPED_STATS;
    6038        2656 :         xl_dropped_stats.nitems = ndroppedstats;
    6039             :     }
    6040             : 
    6041       11620 :     if (TransactionIdIsValid(twophase_xid))
    6042             :     {
    6043          80 :         xl_xinfo.xinfo |= XACT_XINFO_HAS_TWOPHASE;
    6044          80 :         xl_twophase.xid = twophase_xid;
    6045             :         Assert(twophase_gid != NULL);
    6046             : 
    6047          80 :         if (XLogLogicalInfoActive())
    6048          26 :             xl_xinfo.xinfo |= XACT_XINFO_HAS_GID;
    6049             :     }
    6050             : 
    6051       11620 :     if (TransactionIdIsValid(twophase_xid) && XLogLogicalInfoActive())
    6052             :     {
    6053          26 :         xl_xinfo.xinfo |= XACT_XINFO_HAS_DBINFO;
    6054          26 :         xl_dbinfo.dbId = MyDatabaseId;
    6055          26 :         xl_dbinfo.tsId = MyDatabaseTableSpace;
    6056             :     }
    6057             : 
    6058             :     /*
    6059             :      * Dump transaction origin information. We need this during recovery to
    6060             :      * update the replication origin progress.
    6061             :      */
    6062       11620 :     if (replorigin_session_origin != InvalidRepOriginId)
    6063             :     {
    6064          62 :         xl_xinfo.xinfo |= XACT_XINFO_HAS_ORIGIN;
    6065             : 
    6066          62 :         xl_origin.origin_lsn = replorigin_session_origin_lsn;
    6067          62 :         xl_origin.origin_timestamp = replorigin_session_origin_timestamp;
    6068             :     }
    6069             : 
    6070       11620 :     if (xl_xinfo.xinfo != 0)
    6071        5952 :         info |= XLOG_XACT_HAS_INFO;
    6072             : 
    6073             :     /* Then include all the collected data into the abort record. */
    6074             : 
    6075       11620 :     XLogBeginInsert();
    6076             : 
    6077       11620 :     XLogRegisterData(&xlrec, MinSizeOfXactAbort);
    6078             : 
    6079       11620 :     if (xl_xinfo.xinfo != 0)
    6080        5952 :         XLogRegisterData(&xl_xinfo, sizeof(xl_xinfo));
    6081             : 
    6082       11620 :     if (xl_xinfo.xinfo & XACT_XINFO_HAS_DBINFO)
    6083          26 :         XLogRegisterData(&xl_dbinfo, sizeof(xl_dbinfo));
    6084             : 
    6085       11620 :     if (xl_xinfo.xinfo & XACT_XINFO_HAS_SUBXACTS)
    6086             :     {
    6087         202 :         XLogRegisterData(&xl_subxacts,
    6088             :                          MinSizeOfXactSubxacts);
    6089         202 :         XLogRegisterData(subxacts,
    6090             :                          nsubxacts * sizeof(TransactionId));
    6091             :     }
    6092             : 
    6093       11620 :     if (xl_xinfo.xinfo & XACT_XINFO_HAS_RELFILELOCATORS)
    6094             :     {
    6095        1944 :         XLogRegisterData(&xl_relfilelocators,
    6096             :                          MinSizeOfXactRelfileLocators);
    6097        1944 :         XLogRegisterData(rels,
    6098             :                          nrels * sizeof(RelFileLocator));
    6099             :     }
    6100             : 
    6101       11620 :     if (xl_xinfo.xinfo & XACT_XINFO_HAS_DROPPED_STATS)
    6102             :     {
    6103        2656 :         XLogRegisterData(&xl_dropped_stats,
    6104             :                          MinSizeOfXactStatsItems);
    6105        2656 :         XLogRegisterData(droppedstats,
    6106             :                          ndroppedstats * sizeof(xl_xact_stats_item));
    6107             :     }
    6108             : 
    6109       11620 :     if (xl_xinfo.xinfo & XACT_XINFO_HAS_TWOPHASE)
    6110             :     {
    6111          80 :         XLogRegisterData(&xl_twophase, sizeof(xl_xact_twophase));
    6112          80 :         if (xl_xinfo.xinfo & XACT_XINFO_HAS_GID)
    6113          26 :             XLogRegisterData(twophase_gid, strlen(twophase_gid) + 1);
    6114             :     }
    6115             : 
    6116       11620 :     if (xl_xinfo.xinfo & XACT_XINFO_HAS_ORIGIN)
    6117          62 :         XLogRegisterData(&xl_origin, sizeof(xl_xact_origin));
    6118             : 
    6119             :     /* Include the replication origin */
    6120       11620 :     XLogSetRecordFlags(XLOG_INCLUDE_ORIGIN);
    6121             : 
    6122       11620 :     return XLogInsert(RM_XACT_ID, info);
    6123             : }
    6124             : 
    6125             : /*
    6126             :  * Before 9.0 this was a fairly short function, but now it performs many
    6127             :  * actions for which the order of execution is critical.
    6128             :  */
    6129             : static void
    6130       42758 : xact_redo_commit(xl_xact_parsed_commit *parsed,
    6131             :                  TransactionId xid,
    6132             :                  XLogRecPtr lsn,
    6133             :                  RepOriginId origin_id)
    6134             : {
    6135             :     TransactionId max_xid;
    6136             :     TimestampTz commit_time;
    6137             : 
    6138             :     Assert(TransactionIdIsValid(xid));
    6139             : 
    6140       42758 :     max_xid = TransactionIdLatest(xid, parsed->nsubxacts, parsed->subxacts);
    6141             : 
    6142             :     /* Make sure nextXid is beyond any XID mentioned in the record. */
    6143       42758 :     AdvanceNextFullTransactionIdPastXid(max_xid);
    6144             : 
    6145             :     Assert(((parsed->xinfo & XACT_XINFO_HAS_ORIGIN) == 0) ==
    6146             :            (origin_id == InvalidRepOriginId));
    6147             : 
    6148       42758 :     if (parsed->xinfo & XACT_XINFO_HAS_ORIGIN)
    6149          40 :         commit_time = parsed->origin_timestamp;
    6150             :     else
    6151       42718 :         commit_time = parsed->xact_time;
    6152             : 
    6153             :     /* Set the transaction commit timestamp and metadata */
    6154       42758 :     TransactionTreeSetCommitTsData(xid, parsed->nsubxacts, parsed->subxacts,
    6155             :                                    commit_time, origin_id);
    6156             : 
    6157       42758 :     if (standbyState == STANDBY_DISABLED)
    6158             :     {
    6159             :         /*
    6160             :          * Mark the transaction committed in pg_xact.
    6161             :          */
    6162        4452 :         TransactionIdCommitTree(xid, parsed->nsubxacts, parsed->subxacts);
    6163             :     }
    6164             :     else
    6165             :     {
    6166             :         /*
    6167             :          * If a transaction completion record arrives that has as-yet
    6168             :          * unobserved subtransactions then this will not have been fully
    6169             :          * handled by the call to RecordKnownAssignedTransactionIds() in the
    6170             :          * main recovery loop in xlog.c. So we need to do bookkeeping again to
    6171             :          * cover that case. This is confusing and it is easy to think this
    6172             :          * call is irrelevant, which has happened three times in development
    6173             :          * already. Leave it in.
    6174             :          */
    6175       38306 :         RecordKnownAssignedTransactionIds(max_xid);
    6176             : 
    6177             :         /*
    6178             :          * Mark the transaction committed in pg_xact. We use async commit
    6179             :          * protocol during recovery to provide information on database
    6180             :          * consistency for when users try to set hint bits. It is important
    6181             :          * that we do not set hint bits until the minRecoveryPoint is past
    6182             :          * this commit record. This ensures that if we crash we don't see hint
    6183             :          * bits set on changes made by transactions that haven't yet
    6184             :          * recovered. It's unlikely but it's good to be safe.
    6185             :          */
    6186       38306 :         TransactionIdAsyncCommitTree(xid, parsed->nsubxacts, parsed->subxacts, lsn);
    6187             : 
    6188             :         /*
    6189             :          * We must mark clog before we update the ProcArray.
    6190             :          */
    6191       38306 :         ExpireTreeKnownAssignedTransactionIds(xid, parsed->nsubxacts, parsed->subxacts, max_xid);
    6192             : 
    6193             :         /*
    6194             :          * Send any cache invalidations attached to the commit. We must
    6195             :          * maintain the same order of invalidation then release locks as
    6196             :          * occurs in CommitTransaction().
    6197             :          */
    6198       38306 :         ProcessCommittedInvalidationMessages(parsed->msgs, parsed->nmsgs,
    6199       38306 :                                              XactCompletionRelcacheInitFileInval(parsed->xinfo),
    6200             :                                              parsed->dbId, parsed->tsId);
    6201             : 
    6202             :         /*
    6203             :          * Release locks, if any. We do this for both two phase and normal one
    6204             :          * phase transactions. In effect we are ignoring the prepare phase and
    6205             :          * just going straight to lock release.
    6206             :          */
    6207       38306 :         if (parsed->xinfo & XACT_XINFO_HAS_AE_LOCKS)
    6208       18550 :             StandbyReleaseLockTree(xid, parsed->nsubxacts, parsed->subxacts);
    6209             :     }
    6210             : 
    6211       42758 :     if (parsed->xinfo & XACT_XINFO_HAS_ORIGIN)
    6212             :     {
    6213             :         /* recover apply progress */
    6214          40 :         replorigin_advance(origin_id, parsed->origin_lsn, lsn,
    6215             :                            false /* backward */ , false /* WAL */ );
    6216             :     }
    6217             : 
    6218             :     /* Make sure files supposed to be dropped are dropped */
    6219       42758 :     if (parsed->nrels > 0)
    6220             :     {
    6221             :         /*
    6222             :          * First update minimum recovery point to cover this WAL record. Once
    6223             :          * a relation is deleted, there's no going back. The buffer manager
    6224             :          * enforces the WAL-first rule for normal updates to relation files,
    6225             :          * so that the minimum recovery point is always updated before the
    6226             :          * corresponding change in the data file is flushed to disk, but we
    6227             :          * have to do the same here since we're bypassing the buffer manager.
    6228             :          *
    6229             :          * Doing this before deleting the files means that if a deletion fails
    6230             :          * for some reason, you cannot start up the system even after restart,
    6231             :          * until you fix the underlying situation so that the deletion will
    6232             :          * succeed. Alternatively, we could update the minimum recovery point
    6233             :          * after deletion, but that would leave a small window where the
    6234             :          * WAL-first rule would be violated.
    6235             :          */
    6236        3970 :         XLogFlush(lsn);
    6237             : 
    6238             :         /* Make sure files supposed to be dropped are dropped */
    6239        3970 :         DropRelationFiles(parsed->xlocators, parsed->nrels, true);
    6240             :     }
    6241             : 
    6242       42758 :     if (parsed->nstats > 0)
    6243             :     {
    6244             :         /* see equivalent call for relations above */
    6245        5178 :         XLogFlush(lsn);
    6246             : 
    6247        5178 :         pgstat_execute_transactional_drops(parsed->nstats, parsed->stats, true);
    6248             :     }
    6249             : 
    6250             :     /*
    6251             :      * We issue an XLogFlush() for the same reason we emit ForceSyncCommit()
    6252             :      * in normal operation. For example, in CREATE DATABASE, we copy all files
    6253             :      * from the template database, and then commit the transaction. If we
    6254             :      * crash after all the files have been copied but before the commit, you
    6255             :      * have files in the data directory without an entry in pg_database. To
    6256             :      * minimize the window for that, we use ForceSyncCommit() to rush the
    6257             :      * commit record to disk as quick as possible. We have the same window
    6258             :      * during recovery, and forcing an XLogFlush() (which updates
    6259             :      * minRecoveryPoint during recovery) helps to reduce that problem window,
    6260             :      * for any user that requested ForceSyncCommit().
    6261             :      */
    6262       42758 :     if (XactCompletionForceSyncCommit(parsed->xinfo))
    6263          94 :         XLogFlush(lsn);
    6264             : 
    6265             :     /*
    6266             :      * If asked by the primary (because someone is waiting for a synchronous
    6267             :      * commit = remote_apply), we will need to ask walreceiver to send a reply
    6268             :      * immediately.
    6269             :      */
    6270       42758 :     if (XactCompletionApplyFeedback(parsed->xinfo))
    6271           4 :         XLogRequestWalReceiverReply();
    6272       42758 : }
    6273             : 
    6274             : /*
    6275             :  * Be careful with the order of execution, as with xact_redo_commit().
    6276             :  * The two functions are similar but differ in key places.
    6277             :  *
    6278             :  * Note also that an abort can be for a subtransaction and its children,
    6279             :  * not just for a top level abort. That means we have to consider
    6280             :  * topxid != xid, whereas in commit we would find topxid == xid always
    6281             :  * because subtransaction commit is never WAL logged.
    6282             :  */
    6283             : static void
    6284        3508 : xact_redo_abort(xl_xact_parsed_abort *parsed, TransactionId xid,
    6285             :                 XLogRecPtr lsn, RepOriginId origin_id)
    6286             : {
    6287             :     TransactionId max_xid;
    6288             : 
    6289             :     Assert(TransactionIdIsValid(xid));
    6290             : 
    6291             :     /* Make sure nextXid is beyond any XID mentioned in the record. */
    6292        3508 :     max_xid = TransactionIdLatest(xid,
    6293             :                                   parsed->nsubxacts,
    6294        3508 :                                   parsed->subxacts);
    6295        3508 :     AdvanceNextFullTransactionIdPastXid(max_xid);
    6296             : 
    6297        3508 :     if (standbyState == STANDBY_DISABLED)
    6298             :     {
    6299             :         /* Mark the transaction aborted in pg_xact, no need for async stuff */
    6300          40 :         TransactionIdAbortTree(xid, parsed->nsubxacts, parsed->subxacts);
    6301             :     }
    6302             :     else
    6303             :     {
    6304             :         /*
    6305             :          * If a transaction completion record arrives that has as-yet
    6306             :          * unobserved subtransactions then this will not have been fully
    6307             :          * handled by the call to RecordKnownAssignedTransactionIds() in the
    6308             :          * main recovery loop in xlog.c. So we need to do bookkeeping again to
    6309             :          * cover that case. This is confusing and it is easy to think this
    6310             :          * call is irrelevant, which has happened three times in development
    6311             :          * already. Leave it in.
    6312             :          */
    6313        3468 :         RecordKnownAssignedTransactionIds(max_xid);
    6314             : 
    6315             :         /* Mark the transaction aborted in pg_xact, no need for async stuff */
    6316        3468 :         TransactionIdAbortTree(xid, parsed->nsubxacts, parsed->subxacts);
    6317             : 
    6318             :         /*
    6319             :          * We must update the ProcArray after we have marked clog.
    6320             :          */
    6321        3468 :         ExpireTreeKnownAssignedTransactionIds(xid, parsed->nsubxacts, parsed->subxacts, max_xid);
    6322             : 
    6323             :         /*
    6324             :          * There are no invalidation messages to send or undo.
    6325             :          */
    6326             : 
    6327             :         /*
    6328             :          * Release locks, if any. There are no invalidations to send.
    6329             :          */
    6330        3468 :         if (parsed->xinfo & XACT_XINFO_HAS_AE_LOCKS)
    6331        2164 :             StandbyReleaseLockTree(xid, parsed->nsubxacts, parsed->subxacts);
    6332             :     }
    6333             : 
    6334        3508 :     if (parsed->xinfo & XACT_XINFO_HAS_ORIGIN)
    6335             :     {
    6336             :         /* recover apply progress */
    6337          10 :         replorigin_advance(origin_id, parsed->origin_lsn, lsn,
    6338             :                            false /* backward */ , false /* WAL */ );
    6339             :     }
    6340             : 
    6341             :     /* Make sure files supposed to be dropped are dropped */
    6342        3508 :     if (parsed->nrels > 0)
    6343             :     {
    6344             :         /*
    6345             :          * See comments about update of minimum recovery point on truncation,
    6346             :          * in xact_redo_commit().
    6347             :          */
    6348         614 :         XLogFlush(lsn);
    6349             : 
    6350         614 :         DropRelationFiles(parsed->xlocators, parsed->nrels, true);
    6351             :     }
    6352             : 
    6353        3508 :     if (parsed->nstats > 0)
    6354             :     {
    6355             :         /* see equivalent call for relations above */
    6356         814 :         XLogFlush(lsn);
    6357             : 
    6358         814 :         pgstat_execute_transactional_drops(parsed->nstats, parsed->stats, true);
    6359             :     }
    6360        3508 : }
    6361             : 
    6362             : void
    6363       46890 : xact_redo(XLogReaderState *record)
    6364             : {
    6365       46890 :     uint8       info = XLogRecGetInfo(record) & XLOG_XACT_OPMASK;
    6366             : 
    6367             :     /* Backup blocks are not used in xact records */
    6368             :     Assert(!XLogRecHasAnyBlockRefs(record));
    6369             : 
    6370       46890 :     if (info == XLOG_XACT_COMMIT)
    6371             :     {
    6372       42670 :         xl_xact_commit *xlrec = (xl_xact_commit *) XLogRecGetData(record);
    6373             :         xl_xact_parsed_commit parsed;
    6374             : 
    6375       42670 :         ParseCommitRecord(XLogRecGetInfo(record), xlrec, &parsed);
    6376       42670 :         xact_redo_commit(&parsed, XLogRecGetXid(record),
    6377       42670 :                          record->EndRecPtr, XLogRecGetOrigin(record));
    6378             :     }
    6379        4220 :     else if (info == XLOG_XACT_COMMIT_PREPARED)
    6380             :     {
    6381          88 :         xl_xact_commit *xlrec = (xl_xact_commit *) XLogRecGetData(record);
    6382             :         xl_xact_parsed_commit parsed;
    6383             : 
    6384          88 :         ParseCommitRecord(XLogRecGetInfo(record), xlrec, &parsed);
    6385          88 :         xact_redo_commit(&parsed, parsed.twophase_xid,
    6386          88 :                          record->EndRecPtr, XLogRecGetOrigin(record));
    6387             : 
    6388             :         /* Delete TwoPhaseState gxact entry and/or 2PC file. */
    6389          88 :         LWLockAcquire(TwoPhaseStateLock, LW_EXCLUSIVE);
    6390          88 :         PrepareRedoRemove(parsed.twophase_xid, false);
    6391          88 :         LWLockRelease(TwoPhaseStateLock);
    6392             :     }
    6393        4132 :     else if (info == XLOG_XACT_ABORT)
    6394             :     {
    6395        3466 :         xl_xact_abort *xlrec = (xl_xact_abort *) XLogRecGetData(record);
    6396             :         xl_xact_parsed_abort parsed;
    6397             : 
    6398        3466 :         ParseAbortRecord(XLogRecGetInfo(record), xlrec, &parsed);
    6399        3466 :         xact_redo_abort(&parsed, XLogRecGetXid(record),
    6400        3466 :                         record->EndRecPtr, XLogRecGetOrigin(record));
    6401             :     }
    6402         666 :     else if (info == XLOG_XACT_ABORT_PREPARED)
    6403             :     {
    6404          42 :         xl_xact_abort *xlrec = (xl_xact_abort *) XLogRecGetData(record);
    6405             :         xl_xact_parsed_abort parsed;
    6406             : 
    6407          42 :         ParseAbortRecord(XLogRecGetInfo(record), xlrec, &parsed);
    6408          42 :         xact_redo_abort(&parsed, parsed.twophase_xid,
    6409          42 :                         record->EndRecPtr, XLogRecGetOrigin(record));
    6410             : 
    6411             :         /* Delete TwoPhaseState gxact entry and/or 2PC file. */
    6412          42 :         LWLockAcquire(TwoPhaseStateLock, LW_EXCLUSIVE);
    6413          42 :         PrepareRedoRemove(parsed.twophase_xid, false);
    6414          42 :         LWLockRelease(TwoPhaseStateLock);
    6415             :     }
    6416         624 :     else if (info == XLOG_XACT_PREPARE)
    6417             :     {
    6418             :         /*
    6419             :          * Store xid and start/end pointers of the WAL record in TwoPhaseState
    6420             :          * gxact entry.
    6421             :          */
    6422         150 :         LWLockAcquire(TwoPhaseStateLock, LW_EXCLUSIVE);
    6423         150 :         PrepareRedoAdd(XLogRecGetData(record),
    6424             :                        record->ReadRecPtr,
    6425             :                        record->EndRecPtr,
    6426         150 :                        XLogRecGetOrigin(record));
    6427         150 :         LWLockRelease(TwoPhaseStateLock);
    6428             :     }
    6429         474 :     else if (info == XLOG_XACT_ASSIGNMENT)
    6430             :     {
    6431          42 :         xl_xact_assignment *xlrec = (xl_xact_assignment *) XLogRecGetData(record);
    6432             : 
    6433          42 :         if (standbyState >= STANDBY_INITIALIZED)
    6434          42 :             ProcArrayApplyXidAssignment(xlrec->xtop,
    6435          42 :                                         xlrec->nsubxacts, xlrec->xsub);
    6436             :     }
    6437         432 :     else if (info == XLOG_XACT_INVALIDATIONS)
    6438             :     {
    6439             :         /*
    6440             :          * XXX we do ignore this for now, what matters are invalidations
    6441             :          * written into the commit record.
    6442             :          */
    6443             :     }
    6444             :     else
    6445           0 :         elog(PANIC, "xact_redo: unknown op code %u", info);
    6446       46890 : }

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