LCOV - code coverage report
Current view: top level - src/backend/utils/init - postinit.c (source / functions) Hit Total Coverage
Test: PostgreSQL 18devel Lines: 324 353 91.8 %
Date: 2024-12-02 20:15:07 Functions: 19 20 95.0 %
Legend: Lines: hit not hit

          Line data    Source code
       1             : /*-------------------------------------------------------------------------
       2             :  *
       3             :  * postinit.c
       4             :  *    postgres initialization utilities
       5             :  *
       6             :  * Portions Copyright (c) 1996-2024, PostgreSQL Global Development Group
       7             :  * Portions Copyright (c) 1994, Regents of the University of California
       8             :  *
       9             :  *
      10             :  * IDENTIFICATION
      11             :  *    src/backend/utils/init/postinit.c
      12             :  *
      13             :  *
      14             :  *-------------------------------------------------------------------------
      15             :  */
      16             : #include "postgres.h"
      17             : 
      18             : #include <ctype.h>
      19             : #include <fcntl.h>
      20             : #include <unistd.h>
      21             : 
      22             : #include "access/genam.h"
      23             : #include "access/heapam.h"
      24             : #include "access/htup_details.h"
      25             : #include "access/parallel.h"
      26             : #include "access/session.h"
      27             : #include "access/tableam.h"
      28             : #include "access/xact.h"
      29             : #include "access/xlog.h"
      30             : #include "access/xloginsert.h"
      31             : #include "catalog/namespace.h"
      32             : #include "catalog/pg_authid.h"
      33             : #include "catalog/pg_collation.h"
      34             : #include "catalog/pg_database.h"
      35             : #include "catalog/pg_db_role_setting.h"
      36             : #include "catalog/pg_tablespace.h"
      37             : #include "libpq/auth.h"
      38             : #include "libpq/libpq-be.h"
      39             : #include "mb/pg_wchar.h"
      40             : #include "miscadmin.h"
      41             : #include "pgstat.h"
      42             : #include "postmaster/autovacuum.h"
      43             : #include "postmaster/postmaster.h"
      44             : #include "replication/slot.h"
      45             : #include "replication/slotsync.h"
      46             : #include "replication/walsender.h"
      47             : #include "storage/bufmgr.h"
      48             : #include "storage/fd.h"
      49             : #include "storage/ipc.h"
      50             : #include "storage/lmgr.h"
      51             : #include "storage/proc.h"
      52             : #include "storage/procarray.h"
      53             : #include "storage/procsignal.h"
      54             : #include "storage/sinvaladt.h"
      55             : #include "storage/smgr.h"
      56             : #include "storage/sync.h"
      57             : #include "tcop/tcopprot.h"
      58             : #include "utils/acl.h"
      59             : #include "utils/builtins.h"
      60             : #include "utils/fmgroids.h"
      61             : #include "utils/guc_hooks.h"
      62             : #include "utils/memutils.h"
      63             : #include "utils/pg_locale.h"
      64             : #include "utils/portal.h"
      65             : #include "utils/ps_status.h"
      66             : #include "utils/snapmgr.h"
      67             : #include "utils/syscache.h"
      68             : #include "utils/timeout.h"
      69             : 
      70             : static HeapTuple GetDatabaseTuple(const char *dbname);
      71             : static HeapTuple GetDatabaseTupleByOid(Oid dboid);
      72             : static void PerformAuthentication(Port *port);
      73             : static void CheckMyDatabase(const char *name, bool am_superuser, bool override_allow_connections);
      74             : static void ShutdownPostgres(int code, Datum arg);
      75             : static void StatementTimeoutHandler(void);
      76             : static void LockTimeoutHandler(void);
      77             : static void IdleInTransactionSessionTimeoutHandler(void);
      78             : static void TransactionTimeoutHandler(void);
      79             : static void IdleSessionTimeoutHandler(void);
      80             : static void IdleStatsUpdateTimeoutHandler(void);
      81             : static void ClientCheckTimeoutHandler(void);
      82             : static bool ThereIsAtLeastOneRole(void);
      83             : static void process_startup_options(Port *port, bool am_superuser);
      84             : static void process_settings(Oid databaseid, Oid roleid);
      85             : 
      86             : 
      87             : /*** InitPostgres support ***/
      88             : 
      89             : 
      90             : /*
      91             :  * GetDatabaseTuple -- fetch the pg_database row for a database
      92             :  *
      93             :  * This is used during backend startup when we don't yet have any access to
      94             :  * system catalogs in general.  In the worst case, we can seqscan pg_database
      95             :  * using nothing but the hard-wired descriptor that relcache.c creates for
      96             :  * pg_database.  In more typical cases, relcache.c was able to load
      97             :  * descriptors for both pg_database and its indexes from the shared relcache
      98             :  * cache file, and so we can do an indexscan.  criticalSharedRelcachesBuilt
      99             :  * tells whether we got the cached descriptors.
     100             :  */
     101             : static HeapTuple
     102       21482 : GetDatabaseTuple(const char *dbname)
     103             : {
     104             :     HeapTuple   tuple;
     105             :     Relation    relation;
     106             :     SysScanDesc scan;
     107             :     ScanKeyData key[1];
     108             : 
     109             :     /*
     110             :      * form a scan key
     111             :      */
     112       21482 :     ScanKeyInit(&key[0],
     113             :                 Anum_pg_database_datname,
     114             :                 BTEqualStrategyNumber, F_NAMEEQ,
     115             :                 CStringGetDatum(dbname));
     116             : 
     117             :     /*
     118             :      * Open pg_database and fetch a tuple.  Force heap scan if we haven't yet
     119             :      * built the critical shared relcache entries (i.e., we're starting up
     120             :      * without a shared relcache cache file).
     121             :      */
     122       21482 :     relation = table_open(DatabaseRelationId, AccessShareLock);
     123       21482 :     scan = systable_beginscan(relation, DatabaseNameIndexId,
     124             :                               criticalSharedRelcachesBuilt,
     125             :                               NULL,
     126             :                               1, key);
     127             : 
     128       21482 :     tuple = systable_getnext(scan);
     129             : 
     130             :     /* Must copy tuple before releasing buffer */
     131       21482 :     if (HeapTupleIsValid(tuple))
     132       21464 :         tuple = heap_copytuple(tuple);
     133             : 
     134             :     /* all done */
     135       21482 :     systable_endscan(scan);
     136       21482 :     table_close(relation, AccessShareLock);
     137             : 
     138       21482 :     return tuple;
     139             : }
     140             : 
     141             : /*
     142             :  * GetDatabaseTupleByOid -- as above, but search by database OID
     143             :  */
     144             : static HeapTuple
     145       25960 : GetDatabaseTupleByOid(Oid dboid)
     146             : {
     147             :     HeapTuple   tuple;
     148             :     Relation    relation;
     149             :     SysScanDesc scan;
     150             :     ScanKeyData key[1];
     151             : 
     152             :     /*
     153             :      * form a scan key
     154             :      */
     155       25960 :     ScanKeyInit(&key[0],
     156             :                 Anum_pg_database_oid,
     157             :                 BTEqualStrategyNumber, F_OIDEQ,
     158             :                 ObjectIdGetDatum(dboid));
     159             : 
     160             :     /*
     161             :      * Open pg_database and fetch a tuple.  Force heap scan if we haven't yet
     162             :      * built the critical shared relcache entries (i.e., we're starting up
     163             :      * without a shared relcache cache file).
     164             :      */
     165       25960 :     relation = table_open(DatabaseRelationId, AccessShareLock);
     166       25960 :     scan = systable_beginscan(relation, DatabaseOidIndexId,
     167             :                               criticalSharedRelcachesBuilt,
     168             :                               NULL,
     169             :                               1, key);
     170             : 
     171       25960 :     tuple = systable_getnext(scan);
     172             : 
     173             :     /* Must copy tuple before releasing buffer */
     174       25960 :     if (HeapTupleIsValid(tuple))
     175       25960 :         tuple = heap_copytuple(tuple);
     176             : 
     177             :     /* all done */
     178       25960 :     systable_endscan(scan);
     179       25960 :     table_close(relation, AccessShareLock);
     180             : 
     181       25960 :     return tuple;
     182             : }
     183             : 
     184             : 
     185             : /*
     186             :  * PerformAuthentication -- authenticate a remote client
     187             :  *
     188             :  * returns: nothing.  Will not return at all if there's any failure.
     189             :  */
     190             : static void
     191       22402 : PerformAuthentication(Port *port)
     192             : {
     193             :     /* This should be set already, but let's make sure */
     194       22402 :     ClientAuthInProgress = true;    /* limit visibility of log messages */
     195             : 
     196             :     /*
     197             :      * In EXEC_BACKEND case, we didn't inherit the contents of pg_hba.conf
     198             :      * etcetera from the postmaster, and have to load them ourselves.
     199             :      *
     200             :      * FIXME: [fork/exec] Ugh.  Is there a way around this overhead?
     201             :      */
     202             : #ifdef EXEC_BACKEND
     203             : 
     204             :     /*
     205             :      * load_hba() and load_ident() want to work within the PostmasterContext,
     206             :      * so create that if it doesn't exist (which it won't).  We'll delete it
     207             :      * again later, in PostgresMain.
     208             :      */
     209             :     if (PostmasterContext == NULL)
     210             :         PostmasterContext = AllocSetContextCreate(TopMemoryContext,
     211             :                                                   "Postmaster",
     212             :                                                   ALLOCSET_DEFAULT_SIZES);
     213             : 
     214             :     if (!load_hba())
     215             :     {
     216             :         /*
     217             :          * It makes no sense to continue if we fail to load the HBA file,
     218             :          * since there is no way to connect to the database in this case.
     219             :          */
     220             :         ereport(FATAL,
     221             :         /* translator: %s is a configuration file */
     222             :                 (errmsg("could not load %s", HbaFileName)));
     223             :     }
     224             : 
     225             :     if (!load_ident())
     226             :     {
     227             :         /*
     228             :          * It is ok to continue if we fail to load the IDENT file, although it
     229             :          * means that you cannot log in using any of the authentication
     230             :          * methods that need a user name mapping. load_ident() already logged
     231             :          * the details of error to the log.
     232             :          */
     233             :     }
     234             : #endif
     235             : 
     236             :     /*
     237             :      * Set up a timeout in case a buggy or malicious client fails to respond
     238             :      * during authentication.  Since we're inside a transaction and might do
     239             :      * database access, we have to use the statement_timeout infrastructure.
     240             :      */
     241       22402 :     enable_timeout_after(STATEMENT_TIMEOUT, AuthenticationTimeout * 1000);
     242             : 
     243             :     /*
     244             :      * Now perform authentication exchange.
     245             :      */
     246       22402 :     set_ps_display("authentication");
     247       22402 :     ClientAuthentication(port); /* might not return, if failure */
     248             : 
     249             :     /*
     250             :      * Done with authentication.  Disable the timeout, and log if needed.
     251             :      */
     252       22272 :     disable_timeout(STATEMENT_TIMEOUT, false);
     253             : 
     254       22272 :     if (Log_connections)
     255             :     {
     256             :         StringInfoData logmsg;
     257             : 
     258         600 :         initStringInfo(&logmsg);
     259         600 :         if (am_walsender)
     260           6 :             appendStringInfo(&logmsg, _("replication connection authorized: user=%s"),
     261             :                              port->user_name);
     262             :         else
     263         594 :             appendStringInfo(&logmsg, _("connection authorized: user=%s"),
     264             :                              port->user_name);
     265         600 :         if (!am_walsender)
     266         594 :             appendStringInfo(&logmsg, _(" database=%s"), port->database_name);
     267             : 
     268         600 :         if (port->application_name != NULL)
     269         600 :             appendStringInfo(&logmsg, _(" application_name=%s"),
     270             :                              port->application_name);
     271             : 
     272             : #ifdef USE_SSL
     273         600 :         if (port->ssl_in_use)
     274         168 :             appendStringInfo(&logmsg, _(" SSL enabled (protocol=%s, cipher=%s, bits=%d)"),
     275             :                              be_tls_get_version(port),
     276             :                              be_tls_get_cipher(port),
     277             :                              be_tls_get_cipher_bits(port));
     278             : #endif
     279             : #ifdef ENABLE_GSS
     280             :         if (port->gss)
     281             :         {
     282             :             const char *princ = be_gssapi_get_princ(port);
     283             : 
     284             :             if (princ)
     285             :                 appendStringInfo(&logmsg,
     286             :                                  _(" GSS (authenticated=%s, encrypted=%s, delegated_credentials=%s, principal=%s)"),
     287             :                                  be_gssapi_get_auth(port) ? _("yes") : _("no"),
     288             :                                  be_gssapi_get_enc(port) ? _("yes") : _("no"),
     289             :                                  be_gssapi_get_delegation(port) ? _("yes") : _("no"),
     290             :                                  princ);
     291             :             else
     292             :                 appendStringInfo(&logmsg,
     293             :                                  _(" GSS (authenticated=%s, encrypted=%s, delegated_credentials=%s)"),
     294             :                                  be_gssapi_get_auth(port) ? _("yes") : _("no"),
     295             :                                  be_gssapi_get_enc(port) ? _("yes") : _("no"),
     296             :                                  be_gssapi_get_delegation(port) ? _("yes") : _("no"));
     297             :         }
     298             : #endif
     299             : 
     300         600 :         ereport(LOG, errmsg_internal("%s", logmsg.data));
     301         600 :         pfree(logmsg.data);
     302             :     }
     303             : 
     304       22272 :     set_ps_display("startup");
     305             : 
     306       22272 :     ClientAuthInProgress = false;   /* client_min_messages is active now */
     307       22272 : }
     308             : 
     309             : 
     310             : /*
     311             :  * CheckMyDatabase -- fetch information from the pg_database entry for our DB
     312             :  */
     313             : static void
     314       25942 : CheckMyDatabase(const char *name, bool am_superuser, bool override_allow_connections)
     315             : {
     316             :     HeapTuple   tup;
     317             :     Form_pg_database dbform;
     318             :     Datum       datum;
     319             :     bool        isnull;
     320             :     char       *collate;
     321             :     char       *ctype;
     322             : 
     323             :     /* Fetch our pg_database row normally, via syscache */
     324       25942 :     tup = SearchSysCache1(DATABASEOID, ObjectIdGetDatum(MyDatabaseId));
     325       25942 :     if (!HeapTupleIsValid(tup))
     326           0 :         elog(ERROR, "cache lookup failed for database %u", MyDatabaseId);
     327       25942 :     dbform = (Form_pg_database) GETSTRUCT(tup);
     328             : 
     329             :     /* This recheck is strictly paranoia */
     330       25942 :     if (strcmp(name, NameStr(dbform->datname)) != 0)
     331           0 :         ereport(FATAL,
     332             :                 (errcode(ERRCODE_UNDEFINED_DATABASE),
     333             :                  errmsg("database \"%s\" has disappeared from pg_database",
     334             :                         name),
     335             :                  errdetail("Database OID %u now seems to belong to \"%s\".",
     336             :                            MyDatabaseId, NameStr(dbform->datname))));
     337             : 
     338             :     /*
     339             :      * Check permissions to connect to the database.
     340             :      *
     341             :      * These checks are not enforced when in standalone mode, so that there is
     342             :      * a way to recover from disabling all access to all databases, for
     343             :      * example "UPDATE pg_database SET datallowconn = false;".
     344             :      *
     345             :      * We do not enforce them for autovacuum worker processes either.
     346             :      */
     347       25942 :     if (IsUnderPostmaster && !AmAutoVacuumWorkerProcess())
     348             :     {
     349             :         /*
     350             :          * Check that the database is currently allowing connections.
     351             :          */
     352       24840 :         if (!dbform->datallowconn && !override_allow_connections)
     353           2 :             ereport(FATAL,
     354             :                     (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
     355             :                      errmsg("database \"%s\" is not currently accepting connections",
     356             :                             name)));
     357             : 
     358             :         /*
     359             :          * Check privilege to connect to the database.  (The am_superuser test
     360             :          * is redundant, but since we have the flag, might as well check it
     361             :          * and save a few cycles.)
     362             :          */
     363       25324 :         if (!am_superuser &&
     364         486 :             object_aclcheck(DatabaseRelationId, MyDatabaseId, GetUserId(),
     365             :                             ACL_CONNECT) != ACLCHECK_OK)
     366           0 :             ereport(FATAL,
     367             :                     (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
     368             :                      errmsg("permission denied for database \"%s\"", name),
     369             :                      errdetail("User does not have CONNECT privilege.")));
     370             : 
     371             :         /*
     372             :          * Check connection limit for this database.
     373             :          *
     374             :          * There is a race condition here --- we create our PGPROC before
     375             :          * checking for other PGPROCs.  If two backends did this at about the
     376             :          * same time, they might both think they were over the limit, while
     377             :          * ideally one should succeed and one fail.  Getting that to work
     378             :          * exactly seems more trouble than it is worth, however; instead we
     379             :          * just document that the connection limit is approximate.
     380             :          */
     381       24838 :         if (dbform->datconnlimit >= 0 &&
     382           0 :             !am_superuser &&
     383           0 :             CountDBConnections(MyDatabaseId) > dbform->datconnlimit)
     384           0 :             ereport(FATAL,
     385             :                     (errcode(ERRCODE_TOO_MANY_CONNECTIONS),
     386             :                      errmsg("too many connections for database \"%s\"",
     387             :                             name)));
     388             :     }
     389             : 
     390             :     /*
     391             :      * OK, we're golden.  Next to-do item is to save the encoding info out of
     392             :      * the pg_database tuple.
     393             :      */
     394       25940 :     SetDatabaseEncoding(dbform->encoding);
     395             :     /* Record it as a GUC internal option, too */
     396       25940 :     SetConfigOption("server_encoding", GetDatabaseEncodingName(),
     397             :                     PGC_INTERNAL, PGC_S_DYNAMIC_DEFAULT);
     398             :     /* If we have no other source of client_encoding, use server encoding */
     399       25940 :     SetConfigOption("client_encoding", GetDatabaseEncodingName(),
     400             :                     PGC_BACKEND, PGC_S_DYNAMIC_DEFAULT);
     401             : 
     402             :     /* assign locale variables */
     403       25940 :     datum = SysCacheGetAttrNotNull(DATABASEOID, tup, Anum_pg_database_datcollate);
     404       25940 :     collate = TextDatumGetCString(datum);
     405       25940 :     datum = SysCacheGetAttrNotNull(DATABASEOID, tup, Anum_pg_database_datctype);
     406       25940 :     ctype = TextDatumGetCString(datum);
     407             : 
     408       25940 :     if (pg_perm_setlocale(LC_COLLATE, collate) == NULL)
     409           0 :         ereport(FATAL,
     410             :                 (errmsg("database locale is incompatible with operating system"),
     411             :                  errdetail("The database was initialized with LC_COLLATE \"%s\", "
     412             :                            " which is not recognized by setlocale().", collate),
     413             :                  errhint("Recreate the database with another locale or install the missing locale.")));
     414             : 
     415       25940 :     if (pg_perm_setlocale(LC_CTYPE, ctype) == NULL)
     416           0 :         ereport(FATAL,
     417             :                 (errmsg("database locale is incompatible with operating system"),
     418             :                  errdetail("The database was initialized with LC_CTYPE \"%s\", "
     419             :                            " which is not recognized by setlocale().", ctype),
     420             :                  errhint("Recreate the database with another locale or install the missing locale.")));
     421             : 
     422       25940 :     if (strcmp(ctype, "C") == 0 ||
     423       23152 :         strcmp(ctype, "POSIX") == 0)
     424        2788 :         database_ctype_is_c = true;
     425             : 
     426       25940 :     init_database_collation();
     427             : 
     428             :     /*
     429             :      * Check collation version.  See similar code in
     430             :      * pg_newlocale_from_collation().  Note that here we warn instead of error
     431             :      * in any case, so that we don't prevent connecting.
     432             :      */
     433       25936 :     datum = SysCacheGetAttr(DATABASEOID, tup, Anum_pg_database_datcollversion,
     434             :                             &isnull);
     435       25936 :     if (!isnull)
     436             :     {
     437             :         char       *actual_versionstr;
     438             :         char       *collversionstr;
     439             :         char       *locale;
     440             : 
     441       24610 :         collversionstr = TextDatumGetCString(datum);
     442             : 
     443       24610 :         if (dbform->datlocprovider == COLLPROVIDER_LIBC)
     444       22918 :             locale = collate;
     445             :         else
     446             :         {
     447        1692 :             datum = SysCacheGetAttrNotNull(DATABASEOID, tup, Anum_pg_database_datlocale);
     448        1692 :             locale = TextDatumGetCString(datum);
     449             :         }
     450             : 
     451       24610 :         actual_versionstr = get_collation_actual_version(dbform->datlocprovider, locale);
     452       24610 :         if (!actual_versionstr)
     453             :             /* should not happen */
     454           0 :             elog(WARNING,
     455             :                  "database \"%s\" has no actual collation version, but a version was recorded",
     456             :                  name);
     457       24610 :         else if (strcmp(actual_versionstr, collversionstr) != 0)
     458           0 :             ereport(WARNING,
     459             :                     (errmsg("database \"%s\" has a collation version mismatch",
     460             :                             name),
     461             :                      errdetail("The database was created using collation version %s, "
     462             :                                "but the operating system provides version %s.",
     463             :                                collversionstr, actual_versionstr),
     464             :                      errhint("Rebuild all objects in this database that use the default collation and run "
     465             :                              "ALTER DATABASE %s REFRESH COLLATION VERSION, "
     466             :                              "or build PostgreSQL with the right library version.",
     467             :                              quote_identifier(name))));
     468             :     }
     469             : 
     470       25936 :     ReleaseSysCache(tup);
     471       25936 : }
     472             : 
     473             : 
     474             : /*
     475             :  * pg_split_opts -- split a string of options and append it to an argv array
     476             :  *
     477             :  * The caller is responsible for ensuring the argv array is large enough.  The
     478             :  * maximum possible number of arguments added by this routine is
     479             :  * (strlen(optstr) + 1) / 2.
     480             :  *
     481             :  * Because some option values can contain spaces we allow escaping using
     482             :  * backslashes, with \\ representing a literal backslash.
     483             :  */
     484             : void
     485        6170 : pg_split_opts(char **argv, int *argcp, const char *optstr)
     486             : {
     487             :     StringInfoData s;
     488             : 
     489        6170 :     initStringInfo(&s);
     490             : 
     491       22650 :     while (*optstr)
     492             :     {
     493       16480 :         bool        last_was_escape = false;
     494             : 
     495       16480 :         resetStringInfo(&s);
     496             : 
     497             :         /* skip over leading space */
     498       31042 :         while (isspace((unsigned char) *optstr))
     499       14562 :             optstr++;
     500             : 
     501       16480 :         if (*optstr == '\0')
     502           0 :             break;
     503             : 
     504             :         /*
     505             :          * Parse a single option, stopping at the first space, unless it's
     506             :          * escaped.
     507             :          */
     508      248354 :         while (*optstr)
     509             :         {
     510      242184 :             if (isspace((unsigned char) *optstr) && !last_was_escape)
     511       10310 :                 break;
     512             : 
     513      231874 :             if (!last_was_escape && *optstr == '\\')
     514          28 :                 last_was_escape = true;
     515             :             else
     516             :             {
     517      231846 :                 last_was_escape = false;
     518      231846 :                 appendStringInfoChar(&s, *optstr);
     519             :             }
     520             : 
     521      231874 :             optstr++;
     522             :         }
     523             : 
     524             :         /* now store the option in the next argv[] position */
     525       16480 :         argv[(*argcp)++] = pstrdup(s.data);
     526             :     }
     527             : 
     528        6170 :     pfree(s.data);
     529        6170 : }
     530             : 
     531             : /*
     532             :  * Initialize MaxBackends value from config options.
     533             :  *
     534             :  * This must be called after modules have had the chance to alter GUCs in
     535             :  * shared_preload_libraries and before shared memory size is determined.
     536             :  *
     537             :  * Note that in EXEC_BACKEND environment, the value is passed down from
     538             :  * postmaster to subprocesses via BackendParameters in SubPostmasterMain; only
     539             :  * postmaster itself and processes not under postmaster control should call
     540             :  * this.
     541             :  */
     542             : void
     543        1898 : InitializeMaxBackends(void)
     544             : {
     545             :     Assert(MaxBackends == 0);
     546             : 
     547             :     /* the extra unit accounts for the autovacuum launcher */
     548        1898 :     MaxBackends = MaxConnections + autovacuum_max_workers + 1 +
     549        1898 :         max_worker_processes + max_wal_senders;
     550             : 
     551        1898 :     if (MaxBackends > MAX_BACKENDS)
     552           0 :         ereport(ERROR,
     553             :                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
     554             :                  errmsg("too many server processes configured"),
     555             :                  errdetail("\"max_connections\" (%d) plus \"autovacuum_max_workers\" (%d) plus \"max_worker_processes\" (%d) plus \"max_wal_senders\" (%d) must be less than %d.",
     556             :                            MaxConnections, autovacuum_max_workers,
     557             :                            max_worker_processes, max_wal_senders,
     558             :                            MAX_BACKENDS)));
     559        1898 : }
     560             : 
     561             : /*
     562             :  * Initialize the number of fast-path lock slots in PGPROC.
     563             :  *
     564             :  * This must be called after modules have had the chance to alter GUCs in
     565             :  * shared_preload_libraries and before shared memory size is determined.
     566             :  *
     567             :  * The default max_locks_per_xact=64 means 4 groups by default.
     568             :  *
     569             :  * We allow anything between 1 and 1024 groups, with the usual power-of-2
     570             :  * logic. The 1 is the "old" size with only 16 slots, 1024 is an arbitrary
     571             :  * limit (matching max_locks_per_xact = 16k). Values over 1024 are unlikely
     572             :  * to be beneficial - there are bottlenecks we'll hit way before that.
     573             :  */
     574             : void
     575        1898 : InitializeFastPathLocks(void)
     576             : {
     577             :     /* Should be initialized only once. */
     578             :     Assert(FastPathLockGroupsPerBackend == 0);
     579             : 
     580             :     /* we need at least one group */
     581        1898 :     FastPathLockGroupsPerBackend = 1;
     582             : 
     583        5694 :     while (FastPathLockGroupsPerBackend < FP_LOCK_GROUPS_PER_BACKEND_MAX)
     584             :     {
     585             :         /* stop once we exceed max_locks_per_xact */
     586        5694 :         if (FastPathLockGroupsPerBackend * FP_LOCK_SLOTS_PER_GROUP >= max_locks_per_xact)
     587        1898 :             break;
     588             : 
     589        3796 :         FastPathLockGroupsPerBackend *= 2;
     590             :     }
     591             : 
     592             :     Assert(FastPathLockGroupsPerBackend <= FP_LOCK_GROUPS_PER_BACKEND_MAX);
     593        1898 : }
     594             : 
     595             : /*
     596             :  * Early initialization of a backend (either standalone or under postmaster).
     597             :  * This happens even before InitPostgres.
     598             :  *
     599             :  * This is separate from InitPostgres because it is also called by auxiliary
     600             :  * processes, such as the background writer process, which may not call
     601             :  * InitPostgres at all.
     602             :  */
     603             : void
     604       33038 : BaseInit(void)
     605             : {
     606             :     Assert(MyProc != NULL);
     607             : 
     608             :     /*
     609             :      * Initialize our input/output/debugging file descriptors.
     610             :      */
     611       33038 :     DebugFileOpen();
     612             : 
     613             :     /*
     614             :      * Initialize file access. Done early so other subsystems can access
     615             :      * files.
     616             :      */
     617       33038 :     InitFileAccess();
     618             : 
     619             :     /*
     620             :      * Initialize statistics reporting. This needs to happen early to ensure
     621             :      * that pgstat's shutdown callback runs after the shutdown callbacks of
     622             :      * all subsystems that can produce stats (like e.g. transaction commits
     623             :      * can).
     624             :      */
     625       33038 :     pgstat_initialize();
     626             : 
     627             :     /* Do local initialization of storage and buffer managers */
     628       33038 :     InitSync();
     629       33038 :     smgrinit();
     630       33038 :     InitBufferManagerAccess();
     631             : 
     632             :     /*
     633             :      * Initialize temporary file access after pgstat, so that the temporary
     634             :      * file shutdown hook can report temporary file statistics.
     635             :      */
     636       33038 :     InitTemporaryFileAccess();
     637             : 
     638             :     /*
     639             :      * Initialize local buffers for WAL record construction, in case we ever
     640             :      * try to insert XLOG.
     641             :      */
     642       33038 :     InitXLogInsert();
     643             : 
     644             :     /* Initialize lock manager's local structs */
     645       33038 :     InitLockManagerAccess();
     646             : 
     647             :     /*
     648             :      * Initialize replication slots after pgstat. The exit hook might need to
     649             :      * drop ephemeral slots, which in turn triggers stats reporting.
     650             :      */
     651       33038 :     ReplicationSlotInitialize();
     652       33038 : }
     653             : 
     654             : 
     655             : /* --------------------------------
     656             :  * InitPostgres
     657             :  *      Initialize POSTGRES.
     658             :  *
     659             :  * Parameters:
     660             :  *  in_dbname, dboid: specify database to connect to, as described below
     661             :  *  username, useroid: specify role to connect as, as described below
     662             :  *  flags:
     663             :  *    - INIT_PG_LOAD_SESSION_LIBS to honor [session|local]_preload_libraries.
     664             :  *    - INIT_PG_OVERRIDE_ALLOW_CONNS to connect despite !datallowconn.
     665             :  *    - INIT_PG_OVERRIDE_ROLE_LOGIN to connect despite !rolcanlogin.
     666             :  *  out_dbname: optional output parameter, see below; pass NULL if not used
     667             :  *
     668             :  * The database can be specified by name, using the in_dbname parameter, or by
     669             :  * OID, using the dboid parameter.  Specify NULL or InvalidOid respectively
     670             :  * for the unused parameter.  If dboid is provided, the actual database
     671             :  * name can be returned to the caller in out_dbname.  If out_dbname isn't
     672             :  * NULL, it must point to a buffer of size NAMEDATALEN.
     673             :  *
     674             :  * Similarly, the role can be passed by name, using the username parameter,
     675             :  * or by OID using the useroid parameter.
     676             :  *
     677             :  * In bootstrap mode the database and username parameters are NULL/InvalidOid.
     678             :  * The autovacuum launcher process doesn't specify these parameters either,
     679             :  * because it only goes far enough to be able to read pg_database; it doesn't
     680             :  * connect to any particular database.  An autovacuum worker specifies a
     681             :  * database but not a username; conversely, a physical walsender specifies
     682             :  * username but not database.
     683             :  *
     684             :  * By convention, INIT_PG_LOAD_SESSION_LIBS should be passed in "flags" in
     685             :  * "interactive" sessions (including standalone backends), but not in
     686             :  * background processes such as autovacuum.  Note in particular that it
     687             :  * shouldn't be true in parallel worker processes; those have another
     688             :  * mechanism for replicating their leader's set of loaded libraries.
     689             :  *
     690             :  * We expect that InitProcess() was already called, so we already have a
     691             :  * PGPROC struct ... but it's not completely filled in yet.
     692             :  *
     693             :  * Note:
     694             :  *      Be very careful with the order of calls in the InitPostgres function.
     695             :  * --------------------------------
     696             :  */
     697             : void
     698       28536 : InitPostgres(const char *in_dbname, Oid dboid,
     699             :              const char *username, Oid useroid,
     700             :              bits32 flags,
     701             :              char *out_dbname)
     702             : {
     703       28536 :     bool        bootstrap = IsBootstrapProcessingMode();
     704             :     bool        am_superuser;
     705             :     char       *fullpath;
     706             :     char        dbname[NAMEDATALEN];
     707       28536 :     int         nfree = 0;
     708             : 
     709       28536 :     elog(DEBUG3, "InitPostgres");
     710             : 
     711             :     /*
     712             :      * Add my PGPROC struct to the ProcArray.
     713             :      *
     714             :      * Once I have done this, I am visible to other backends!
     715             :      */
     716       28536 :     InitProcessPhase2();
     717             : 
     718             :     /*
     719             :      * Initialize my entry in the shared-invalidation manager's array of
     720             :      * per-backend data.
     721             :      */
     722       28536 :     SharedInvalBackendInit(false);
     723             : 
     724       28536 :     ProcSignalInit(MyCancelKeyValid, MyCancelKey);
     725             : 
     726             :     /*
     727             :      * Also set up timeout handlers needed for backend operation.  We need
     728             :      * these in every case except bootstrap.
     729             :      */
     730       28536 :     if (!bootstrap)
     731             :     {
     732       28446 :         RegisterTimeout(DEADLOCK_TIMEOUT, CheckDeadLockAlert);
     733       28446 :         RegisterTimeout(STATEMENT_TIMEOUT, StatementTimeoutHandler);
     734       28446 :         RegisterTimeout(LOCK_TIMEOUT, LockTimeoutHandler);
     735       28446 :         RegisterTimeout(IDLE_IN_TRANSACTION_SESSION_TIMEOUT,
     736             :                         IdleInTransactionSessionTimeoutHandler);
     737       28446 :         RegisterTimeout(TRANSACTION_TIMEOUT, TransactionTimeoutHandler);
     738       28446 :         RegisterTimeout(IDLE_SESSION_TIMEOUT, IdleSessionTimeoutHandler);
     739       28446 :         RegisterTimeout(CLIENT_CONNECTION_CHECK_TIMEOUT, ClientCheckTimeoutHandler);
     740       28446 :         RegisterTimeout(IDLE_STATS_UPDATE_TIMEOUT,
     741             :                         IdleStatsUpdateTimeoutHandler);
     742             :     }
     743             : 
     744             :     /*
     745             :      * If this is either a bootstrap process or a standalone backend, start up
     746             :      * the XLOG machinery, and register to have it closed down at exit. In
     747             :      * other cases, the startup process is responsible for starting up the
     748             :      * XLOG machinery, and the checkpointer for closing it down.
     749             :      */
     750       28536 :     if (!IsUnderPostmaster)
     751             :     {
     752             :         /*
     753             :          * We don't yet have an aux-process resource owner, but StartupXLOG
     754             :          * and ShutdownXLOG will need one.  Hence, create said resource owner
     755             :          * (and register a callback to clean it up after ShutdownXLOG runs).
     756             :          */
     757         198 :         CreateAuxProcessResourceOwner();
     758             : 
     759         198 :         StartupXLOG();
     760             :         /* Release (and warn about) any buffer pins leaked in StartupXLOG */
     761         198 :         ReleaseAuxProcessResources(true);
     762             :         /* Reset CurrentResourceOwner to nothing for the moment */
     763         198 :         CurrentResourceOwner = NULL;
     764             : 
     765             :         /*
     766             :          * Use before_shmem_exit() so that ShutdownXLOG() can rely on DSM
     767             :          * segments etc to work (which in turn is required for pgstats).
     768             :          */
     769         198 :         before_shmem_exit(pgstat_before_server_shutdown, 0);
     770         198 :         before_shmem_exit(ShutdownXLOG, 0);
     771             :     }
     772             : 
     773             :     /*
     774             :      * Initialize the relation cache and the system catalog caches.  Note that
     775             :      * no catalog access happens here; we only set up the hashtable structure.
     776             :      * We must do this before starting a transaction because transaction abort
     777             :      * would try to touch these hashtables.
     778             :      */
     779       28536 :     RelationCacheInitialize();
     780       28536 :     InitCatalogCache();
     781       28536 :     InitPlanCache();
     782             : 
     783             :     /* Initialize portal manager */
     784       28536 :     EnablePortalManager();
     785             : 
     786             :     /* Initialize status reporting */
     787       28536 :     pgstat_beinit();
     788             : 
     789             :     /*
     790             :      * Load relcache entries for the shared system catalogs.  This must create
     791             :      * at least entries for pg_database and catalogs used for authentication.
     792             :      */
     793       28536 :     RelationCacheInitializePhase2();
     794             : 
     795             :     /*
     796             :      * Set up process-exit callback to do pre-shutdown cleanup.  This is the
     797             :      * one of the first before_shmem_exit callbacks we register; thus, this
     798             :      * will be one the last things we do before low-level modules like the
     799             :      * buffer manager begin to close down.  We need to have this in place
     800             :      * before we begin our first transaction --- if we fail during the
     801             :      * initialization transaction, as is entirely possible, we need the
     802             :      * AbortTransaction call to clean up.
     803             :      */
     804       28536 :     before_shmem_exit(ShutdownPostgres, 0);
     805             : 
     806             :     /* The autovacuum launcher is done here */
     807       28536 :     if (AmAutoVacuumLauncherProcess())
     808             :     {
     809             :         /* report this backend in the PgBackendStatus array */
     810         692 :         pgstat_bestart();
     811             : 
     812        2324 :         return;
     813             :     }
     814             : 
     815             :     /*
     816             :      * Start a new transaction here before first access to db, and get a
     817             :      * snapshot.  We don't have a use for the snapshot itself, but we're
     818             :      * interested in the secondary effect that it sets RecentGlobalXmin. (This
     819             :      * is critical for anything that reads heap pages, because HOT may decide
     820             :      * to prune them even if the process doesn't attempt to modify any
     821             :      * tuples.)
     822             :      *
     823             :      * FIXME: This comment is inaccurate / the code buggy. A snapshot that is
     824             :      * not pushed/active does not reliably prevent HOT pruning (->xmin could
     825             :      * e.g. be cleared when cache invalidations are processed).
     826             :      */
     827       27844 :     if (!bootstrap)
     828             :     {
     829             :         /* statement_timestamp must be set for timeouts to work correctly */
     830       27754 :         SetCurrentStatementStartTimestamp();
     831       27754 :         StartTransactionCommand();
     832             : 
     833             :         /*
     834             :          * transaction_isolation will have been set to the default by the
     835             :          * above.  If the default is "serializable", and we are in hot
     836             :          * standby, we will fail if we don't change it to something lower.
     837             :          * Fortunately, "read committed" is plenty good enough.
     838             :          */
     839       27754 :         XactIsoLevel = XACT_READ_COMMITTED;
     840             : 
     841       27754 :         (void) GetTransactionSnapshot();
     842             :     }
     843             : 
     844             :     /*
     845             :      * Perform client authentication if necessary, then figure out our
     846             :      * postgres user ID, and see if we are a superuser.
     847             :      *
     848             :      * In standalone mode, autovacuum worker processes and slot sync worker
     849             :      * process, we use a fixed ID, otherwise we figure it out from the
     850             :      * authenticated user name.
     851             :      */
     852       27844 :     if (bootstrap || AmAutoVacuumWorkerProcess() || AmLogicalSlotSyncWorkerProcess())
     853             :     {
     854        1092 :         InitializeSessionUserIdStandalone();
     855        1092 :         am_superuser = true;
     856             :     }
     857       26752 :     else if (!IsUnderPostmaster)
     858             :     {
     859         108 :         InitializeSessionUserIdStandalone();
     860         108 :         am_superuser = true;
     861         108 :         if (!ThereIsAtLeastOneRole())
     862           0 :             ereport(WARNING,
     863             :                     (errcode(ERRCODE_UNDEFINED_OBJECT),
     864             :                      errmsg("no roles are defined in this database system"),
     865             :                      errhint("You should immediately run CREATE USER \"%s\" SUPERUSER;.",
     866             :                              username != NULL ? username : "postgres")));
     867             :     }
     868       26644 :     else if (AmBackgroundWorkerProcess())
     869             :     {
     870        4242 :         if (username == NULL && !OidIsValid(useroid))
     871             :         {
     872         742 :             InitializeSessionUserIdStandalone();
     873         742 :             am_superuser = true;
     874             :         }
     875             :         else
     876             :         {
     877        3500 :             InitializeSessionUserId(username, useroid,
     878        3500 :                                     (flags & INIT_PG_OVERRIDE_ROLE_LOGIN) != 0);
     879             : 
     880             :             /*
     881             :              * In a parallel worker, set am_superuser based on the
     882             :              * authenticated user ID, not the current role.  This is pretty
     883             :              * dubious but it matches our historical behavior.  Note that this
     884             :              * value of am_superuser is used only for connection-privilege
     885             :              * checks here and in CheckMyDatabase (we won't reach
     886             :              * process_startup_options in a background worker).
     887             :              *
     888             :              * In other cases, there's been no opportunity for the current
     889             :              * role to diverge from the authenticated user ID yet, so we can
     890             :              * just rely on superuser() and avoid an extra catalog lookup.
     891             :              */
     892        3498 :             if (InitializingParallelWorker)
     893        2718 :                 am_superuser = superuser_arg(GetAuthenticatedUserId());
     894             :             else
     895         780 :                 am_superuser = superuser();
     896             :         }
     897             :     }
     898             :     else
     899             :     {
     900             :         /* normal multiuser case */
     901             :         Assert(MyProcPort != NULL);
     902       22402 :         PerformAuthentication(MyProcPort);
     903       22272 :         InitializeSessionUserId(username, useroid, false);
     904             :         /* ensure that auth_method is actually valid, aka authn_id is not NULL */
     905       22264 :         if (MyClientConnectionInfo.authn_id)
     906         204 :             InitializeSystemUser(MyClientConnectionInfo.authn_id,
     907             :                                  hba_authname(MyClientConnectionInfo.auth_method));
     908       22264 :         am_superuser = superuser();
     909             :     }
     910             : 
     911             :     /*
     912             :      * Binary upgrades only allowed super-user connections
     913             :      */
     914       27704 :     if (IsBinaryUpgrade && !am_superuser)
     915             :     {
     916           0 :         ereport(FATAL,
     917             :                 (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
     918             :                  errmsg("must be superuser to connect in binary upgrade mode")));
     919             :     }
     920             : 
     921             :     /*
     922             :      * The last few connection slots are reserved for superusers and roles
     923             :      * with privileges of pg_use_reserved_connections.  Replication
     924             :      * connections are drawn from slots reserved with max_wal_senders and are
     925             :      * not limited by max_connections, superuser_reserved_connections, or
     926             :      * reserved_connections.
     927             :      *
     928             :      * Note: At this point, the new backend has already claimed a proc struct,
     929             :      * so we must check whether the number of free slots is strictly less than
     930             :      * the reserved connection limits.
     931             :      */
     932       27704 :     if (!am_superuser && !am_walsender &&
     933         488 :         (SuperuserReservedConnections + ReservedConnections) > 0 &&
     934         488 :         !HaveNFreeProcs(SuperuserReservedConnections + ReservedConnections, &nfree))
     935             :     {
     936           8 :         if (nfree < SuperuserReservedConnections)
     937           2 :             ereport(FATAL,
     938             :                     (errcode(ERRCODE_TOO_MANY_CONNECTIONS),
     939             :                      errmsg("remaining connection slots are reserved for roles with the %s attribute",
     940             :                             "SUPERUSER")));
     941             : 
     942           6 :         if (!has_privs_of_role(GetUserId(), ROLE_PG_USE_RESERVED_CONNECTIONS))
     943           2 :             ereport(FATAL,
     944             :                     (errcode(ERRCODE_TOO_MANY_CONNECTIONS),
     945             :                      errmsg("remaining connection slots are reserved for roles with privileges of the \"%s\" role",
     946             :                             "pg_use_reserved_connections")));
     947             :     }
     948             : 
     949             :     /* Check replication permissions needed for walsender processes. */
     950       27700 :     if (am_walsender)
     951             :     {
     952             :         Assert(!bootstrap);
     953             : 
     954        2086 :         if (!has_rolreplication(GetUserId()))
     955           0 :             ereport(FATAL,
     956             :                     (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
     957             :                      errmsg("permission denied to start WAL sender"),
     958             :                      errdetail("Only roles with the %s attribute may start a WAL sender process.",
     959             :                                "REPLICATION")));
     960             :     }
     961             : 
     962             :     /*
     963             :      * If this is a plain walsender only supporting physical replication, we
     964             :      * don't want to connect to any particular database. Just finish the
     965             :      * backend startup by processing any options from the startup packet, and
     966             :      * we're done.
     967             :      */
     968       27700 :     if (am_walsender && !am_db_walsender)
     969             :     {
     970             :         /* process any options passed in the startup packet */
     971         894 :         if (MyProcPort != NULL)
     972         894 :             process_startup_options(MyProcPort, am_superuser);
     973             : 
     974             :         /* Apply PostAuthDelay as soon as we've read all options */
     975         894 :         if (PostAuthDelay > 0)
     976           0 :             pg_usleep(PostAuthDelay * 1000000L);
     977             : 
     978             :         /* initialize client encoding */
     979         894 :         InitializeClientEncoding();
     980             : 
     981             :         /* report this backend in the PgBackendStatus array */
     982         894 :         pgstat_bestart();
     983             : 
     984             :         /* close the transaction we started above */
     985         894 :         CommitTransactionCommand();
     986             : 
     987         894 :         return;
     988             :     }
     989             : 
     990             :     /*
     991             :      * Set up the global variables holding database id and default tablespace.
     992             :      * But note we won't actually try to touch the database just yet.
     993             :      *
     994             :      * We take a shortcut in the bootstrap case, otherwise we have to look up
     995             :      * the db's entry in pg_database.
     996             :      */
     997       26806 :     if (bootstrap)
     998             :     {
     999          90 :         dboid = Template1DbOid;
    1000          90 :         MyDatabaseTableSpace = DEFAULTTABLESPACE_OID;
    1001             :     }
    1002       26716 :     else if (in_dbname != NULL)
    1003             :     {
    1004             :         HeapTuple   tuple;
    1005             :         Form_pg_database dbform;
    1006             : 
    1007       21482 :         tuple = GetDatabaseTuple(in_dbname);
    1008       21482 :         if (!HeapTupleIsValid(tuple))
    1009          18 :             ereport(FATAL,
    1010             :                     (errcode(ERRCODE_UNDEFINED_DATABASE),
    1011             :                      errmsg("database \"%s\" does not exist", in_dbname)));
    1012       21464 :         dbform = (Form_pg_database) GETSTRUCT(tuple);
    1013       21464 :         dboid = dbform->oid;
    1014             :     }
    1015        5234 :     else if (!OidIsValid(dboid))
    1016             :     {
    1017             :         /*
    1018             :          * If this is a background worker not bound to any particular
    1019             :          * database, we're done now.  Everything that follows only makes sense
    1020             :          * if we are bound to a specific database.  We do need to close the
    1021             :          * transaction we started before returning.
    1022             :          */
    1023         738 :         if (!bootstrap)
    1024             :         {
    1025         738 :             pgstat_bestart();
    1026         738 :             CommitTransactionCommand();
    1027             :         }
    1028         738 :         return;
    1029             :     }
    1030             : 
    1031             :     /*
    1032             :      * Now, take a writer's lock on the database we are trying to connect to.
    1033             :      * If there is a concurrently running DROP DATABASE on that database, this
    1034             :      * will block us until it finishes (and has committed its update of
    1035             :      * pg_database).
    1036             :      *
    1037             :      * Note that the lock is not held long, only until the end of this startup
    1038             :      * transaction.  This is OK since we will advertise our use of the
    1039             :      * database in the ProcArray before dropping the lock (in fact, that's the
    1040             :      * next thing to do).  Anyone trying a DROP DATABASE after this point will
    1041             :      * see us in the array once they have the lock.  Ordering is important for
    1042             :      * this because we don't want to advertise ourselves as being in this
    1043             :      * database until we have the lock; otherwise we create what amounts to a
    1044             :      * deadlock with CountOtherDBBackends().
    1045             :      *
    1046             :      * Note: use of RowExclusiveLock here is reasonable because we envision
    1047             :      * our session as being a concurrent writer of the database.  If we had a
    1048             :      * way of declaring a session as being guaranteed-read-only, we could use
    1049             :      * AccessShareLock for such sessions and thereby not conflict against
    1050             :      * CREATE DATABASE.
    1051             :      */
    1052       26050 :     if (!bootstrap)
    1053       25960 :         LockSharedObject(DatabaseRelationId, dboid, 0, RowExclusiveLock);
    1054             : 
    1055             :     /*
    1056             :      * Recheck pg_database to make sure the target database hasn't gone away.
    1057             :      * If there was a concurrent DROP DATABASE, this ensures we will die
    1058             :      * cleanly without creating a mess.
    1059             :      */
    1060       26050 :     if (!bootstrap)
    1061             :     {
    1062             :         HeapTuple   tuple;
    1063             :         Form_pg_database datform;
    1064             : 
    1065       25960 :         tuple = GetDatabaseTupleByOid(dboid);
    1066       25960 :         if (HeapTupleIsValid(tuple))
    1067       25960 :             datform = (Form_pg_database) GETSTRUCT(tuple);
    1068             : 
    1069       25960 :         if (!HeapTupleIsValid(tuple) ||
    1070       21464 :             (in_dbname && namestrcmp(&datform->datname, in_dbname)))
    1071             :         {
    1072           0 :             if (in_dbname)
    1073           0 :                 ereport(FATAL,
    1074             :                         (errcode(ERRCODE_UNDEFINED_DATABASE),
    1075             :                          errmsg("database \"%s\" does not exist", in_dbname),
    1076             :                          errdetail("It seems to have just been dropped or renamed.")));
    1077             :             else
    1078           0 :                 ereport(FATAL,
    1079             :                         (errcode(ERRCODE_UNDEFINED_DATABASE),
    1080             :                          errmsg("database %u does not exist", dboid)));
    1081             :         }
    1082             : 
    1083       25960 :         strlcpy(dbname, NameStr(datform->datname), sizeof(dbname));
    1084             : 
    1085       25960 :         if (database_is_invalid_form(datform))
    1086             :         {
    1087          12 :             ereport(FATAL,
    1088             :                     errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
    1089             :                     errmsg("cannot connect to invalid database \"%s\"", dbname),
    1090             :                     errhint("Use DROP DATABASE to drop invalid databases."));
    1091             :         }
    1092             : 
    1093       25948 :         MyDatabaseTableSpace = datform->dattablespace;
    1094       25948 :         MyDatabaseHasLoginEventTriggers = datform->dathasloginevt;
    1095             :         /* pass the database name back to the caller */
    1096       25948 :         if (out_dbname)
    1097         994 :             strcpy(out_dbname, dbname);
    1098             :     }
    1099             : 
    1100             :     /*
    1101             :      * Now that we rechecked, we are certain to be connected to a database and
    1102             :      * thus can set MyDatabaseId.
    1103             :      *
    1104             :      * It is important that MyDatabaseId only be set once we are sure that the
    1105             :      * target database can no longer be concurrently dropped or renamed.  For
    1106             :      * example, without this guarantee, pgstat_update_dbstats() could create
    1107             :      * entries for databases that were just dropped in the pgstat shutdown
    1108             :      * callback, which could confuse other code paths like the autovacuum
    1109             :      * scheduler.
    1110             :      */
    1111       26038 :     MyDatabaseId = dboid;
    1112             : 
    1113             :     /*
    1114             :      * Now we can mark our PGPROC entry with the database ID.
    1115             :      *
    1116             :      * We assume this is an atomic store so no lock is needed; though actually
    1117             :      * things would work fine even if it weren't atomic.  Anyone searching the
    1118             :      * ProcArray for this database's ID should hold the database lock, so they
    1119             :      * would not be executing concurrently with this store.  A process looking
    1120             :      * for another database's ID could in theory see a chance match if it read
    1121             :      * a partially-updated databaseId value; but as long as all such searches
    1122             :      * wait and retry, as in CountOtherDBBackends(), they will certainly see
    1123             :      * the correct value on their next try.
    1124             :      */
    1125       26038 :     MyProc->databaseId = MyDatabaseId;
    1126             : 
    1127             :     /*
    1128             :      * We established a catalog snapshot while reading pg_authid and/or
    1129             :      * pg_database; but until we have set up MyDatabaseId, we won't react to
    1130             :      * incoming sinval messages for unshared catalogs, so we won't realize it
    1131             :      * if the snapshot has been invalidated.  Assume it's no good anymore.
    1132             :      */
    1133       26038 :     InvalidateCatalogSnapshot();
    1134             : 
    1135             :     /*
    1136             :      * Now we should be able to access the database directory safely. Verify
    1137             :      * it's there and looks reasonable.
    1138             :      */
    1139       26038 :     fullpath = GetDatabasePath(MyDatabaseId, MyDatabaseTableSpace);
    1140             : 
    1141       26038 :     if (!bootstrap)
    1142             :     {
    1143       25948 :         if (access(fullpath, F_OK) == -1)
    1144             :         {
    1145           0 :             if (errno == ENOENT)
    1146           0 :                 ereport(FATAL,
    1147             :                         (errcode(ERRCODE_UNDEFINED_DATABASE),
    1148             :                          errmsg("database \"%s\" does not exist",
    1149             :                                 dbname),
    1150             :                          errdetail("The database subdirectory \"%s\" is missing.",
    1151             :                                    fullpath)));
    1152             :             else
    1153           0 :                 ereport(FATAL,
    1154             :                         (errcode_for_file_access(),
    1155             :                          errmsg("could not access directory \"%s\": %m",
    1156             :                                 fullpath)));
    1157             :         }
    1158             : 
    1159       25948 :         ValidatePgVersion(fullpath);
    1160             :     }
    1161             : 
    1162       26038 :     SetDatabasePath(fullpath);
    1163       26038 :     pfree(fullpath);
    1164             : 
    1165             :     /*
    1166             :      * It's now possible to do real access to the system catalogs.
    1167             :      *
    1168             :      * Load relcache entries for the system catalogs.  This must create at
    1169             :      * least the minimum set of "nailed-in" cache entries.
    1170             :      */
    1171       26038 :     RelationCacheInitializePhase3();
    1172             : 
    1173             :     /* set up ACL framework (so CheckMyDatabase can check permissions) */
    1174       26032 :     initialize_acl();
    1175             : 
    1176             :     /*
    1177             :      * Re-read the pg_database row for our database, check permissions and set
    1178             :      * up database-specific GUC settings.  We can't do this until all the
    1179             :      * database-access infrastructure is up.  (Also, it wants to know if the
    1180             :      * user is a superuser, so the above stuff has to happen first.)
    1181             :      */
    1182       26032 :     if (!bootstrap)
    1183       25942 :         CheckMyDatabase(dbname, am_superuser,
    1184       25942 :                         (flags & INIT_PG_OVERRIDE_ALLOW_CONNS) != 0);
    1185             : 
    1186             :     /*
    1187             :      * Now process any command-line switches and any additional GUC variable
    1188             :      * settings passed in the startup packet.   We couldn't do this before
    1189             :      * because we didn't know if client is a superuser.
    1190             :      */
    1191       26026 :     if (MyProcPort != NULL)
    1192       21336 :         process_startup_options(MyProcPort, am_superuser);
    1193             : 
    1194             :     /* Process pg_db_role_setting options */
    1195       26026 :     process_settings(MyDatabaseId, GetSessionUserId());
    1196             : 
    1197             :     /* Apply PostAuthDelay as soon as we've read all options */
    1198       26024 :     if (PostAuthDelay > 0)
    1199           0 :         pg_usleep(PostAuthDelay * 1000000L);
    1200             : 
    1201             :     /*
    1202             :      * Initialize various default states that can't be set up until we've
    1203             :      * selected the active user and gotten the right GUC settings.
    1204             :      */
    1205             : 
    1206             :     /* set default namespace search path */
    1207       26024 :     InitializeSearchPath();
    1208             : 
    1209             :     /* initialize client encoding */
    1210       26024 :     InitializeClientEncoding();
    1211             : 
    1212             :     /* Initialize this backend's session state. */
    1213       26024 :     InitializeSession();
    1214             : 
    1215             :     /*
    1216             :      * If this is an interactive session, load any libraries that should be
    1217             :      * preloaded at backend start.  Since those are determined by GUCs, this
    1218             :      * can't happen until GUC settings are complete, but we want it to happen
    1219             :      * during the initial transaction in case anything that requires database
    1220             :      * access needs to be done.
    1221             :      */
    1222       26024 :     if ((flags & INIT_PG_LOAD_SESSION_LIBS) != 0)
    1223       20248 :         process_session_preload_libraries();
    1224             : 
    1225             :     /* report this backend in the PgBackendStatus array */
    1226       26024 :     if (!bootstrap)
    1227       25934 :         pgstat_bestart();
    1228             : 
    1229             :     /* close the transaction we started above */
    1230       26024 :     if (!bootstrap)
    1231       25934 :         CommitTransactionCommand();
    1232             : }
    1233             : 
    1234             : /*
    1235             :  * Process any command-line switches and any additional GUC variable
    1236             :  * settings passed in the startup packet.
    1237             :  */
    1238             : static void
    1239       22230 : process_startup_options(Port *port, bool am_superuser)
    1240             : {
    1241             :     GucContext  gucctx;
    1242             :     ListCell   *gucopts;
    1243             : 
    1244       22230 :     gucctx = am_superuser ? PGC_SU_BACKEND : PGC_BACKEND;
    1245             : 
    1246             :     /*
    1247             :      * First process any command-line switches that were included in the
    1248             :      * startup packet, if we are in a regular backend.
    1249             :      */
    1250       22230 :     if (port->cmdline_options != NULL)
    1251             :     {
    1252             :         /*
    1253             :          * The maximum possible number of commandline arguments that could
    1254             :          * come from port->cmdline_options is (strlen + 1) / 2; see
    1255             :          * pg_split_opts().
    1256             :          */
    1257             :         char      **av;
    1258             :         int         maxac;
    1259             :         int         ac;
    1260             : 
    1261        6170 :         maxac = 2 + (strlen(port->cmdline_options) + 1) / 2;
    1262             : 
    1263        6170 :         av = (char **) palloc(maxac * sizeof(char *));
    1264        6170 :         ac = 0;
    1265             : 
    1266        6170 :         av[ac++] = "postgres";
    1267             : 
    1268        6170 :         pg_split_opts(av, &ac, port->cmdline_options);
    1269             : 
    1270        6170 :         av[ac] = NULL;
    1271             : 
    1272             :         Assert(ac < maxac);
    1273             : 
    1274        6170 :         (void) process_postgres_switches(ac, av, gucctx, NULL);
    1275             :     }
    1276             : 
    1277             :     /*
    1278             :      * Process any additional GUC variable settings passed in startup packet.
    1279             :      * These are handled exactly like command-line variables.
    1280             :      */
    1281       22230 :     gucopts = list_head(port->guc_options);
    1282       54350 :     while (gucopts)
    1283             :     {
    1284             :         char       *name;
    1285             :         char       *value;
    1286             : 
    1287       32120 :         name = lfirst(gucopts);
    1288       32120 :         gucopts = lnext(port->guc_options, gucopts);
    1289             : 
    1290       32120 :         value = lfirst(gucopts);
    1291       32120 :         gucopts = lnext(port->guc_options, gucopts);
    1292             : 
    1293       32120 :         SetConfigOption(name, value, gucctx, PGC_S_CLIENT);
    1294             :     }
    1295       22230 : }
    1296             : 
    1297             : /*
    1298             :  * Load GUC settings from pg_db_role_setting.
    1299             :  *
    1300             :  * We try specific settings for the database/role combination, as well as
    1301             :  * general for this database and for this user.
    1302             :  */
    1303             : static void
    1304       26026 : process_settings(Oid databaseid, Oid roleid)
    1305             : {
    1306             :     Relation    relsetting;
    1307             :     Snapshot    snapshot;
    1308             : 
    1309       26026 :     if (!IsUnderPostmaster)
    1310         194 :         return;
    1311             : 
    1312       25832 :     relsetting = table_open(DbRoleSettingRelationId, AccessShareLock);
    1313             : 
    1314             :     /* read all the settings under the same snapshot for efficiency */
    1315       25832 :     snapshot = RegisterSnapshot(GetCatalogSnapshot(DbRoleSettingRelationId));
    1316             : 
    1317             :     /* Later settings are ignored if set earlier. */
    1318       25832 :     ApplySetting(snapshot, databaseid, roleid, relsetting, PGC_S_DATABASE_USER);
    1319       25830 :     ApplySetting(snapshot, InvalidOid, roleid, relsetting, PGC_S_USER);
    1320       25830 :     ApplySetting(snapshot, databaseid, InvalidOid, relsetting, PGC_S_DATABASE);
    1321       25830 :     ApplySetting(snapshot, InvalidOid, InvalidOid, relsetting, PGC_S_GLOBAL);
    1322             : 
    1323       25830 :     UnregisterSnapshot(snapshot);
    1324       25830 :     table_close(relsetting, AccessShareLock);
    1325             : }
    1326             : 
    1327             : /*
    1328             :  * Backend-shutdown callback.  Do cleanup that we want to be sure happens
    1329             :  * before all the supporting modules begin to nail their doors shut via
    1330             :  * their own callbacks.
    1331             :  *
    1332             :  * User-level cleanup, such as temp-relation removal and UNLISTEN, happens
    1333             :  * via separate callbacks that execute before this one.  We don't combine the
    1334             :  * callbacks because we still want this one to happen if the user-level
    1335             :  * cleanup fails.
    1336             :  */
    1337             : static void
    1338       28536 : ShutdownPostgres(int code, Datum arg)
    1339             : {
    1340             :     /* Make sure we've killed any active transaction */
    1341       28536 :     AbortOutOfAnyTransaction();
    1342             : 
    1343             :     /*
    1344             :      * User locks are not released by transaction end, so be sure to release
    1345             :      * them explicitly.
    1346             :      */
    1347       28536 :     LockReleaseAll(USER_LOCKMETHOD, true);
    1348       28536 : }
    1349             : 
    1350             : 
    1351             : /*
    1352             :  * STATEMENT_TIMEOUT handler: trigger a query-cancel interrupt.
    1353             :  */
    1354             : static void
    1355          12 : StatementTimeoutHandler(void)
    1356             : {
    1357          12 :     int         sig = SIGINT;
    1358             : 
    1359             :     /*
    1360             :      * During authentication the timeout is used to deal with
    1361             :      * authentication_timeout - we want to quit in response to such timeouts.
    1362             :      */
    1363          12 :     if (ClientAuthInProgress)
    1364           0 :         sig = SIGTERM;
    1365             : 
    1366             : #ifdef HAVE_SETSID
    1367             :     /* try to signal whole process group */
    1368          12 :     kill(-MyProcPid, sig);
    1369             : #endif
    1370          12 :     kill(MyProcPid, sig);
    1371          12 : }
    1372             : 
    1373             : /*
    1374             :  * LOCK_TIMEOUT handler: trigger a query-cancel interrupt.
    1375             :  */
    1376             : static void
    1377           8 : LockTimeoutHandler(void)
    1378             : {
    1379             : #ifdef HAVE_SETSID
    1380             :     /* try to signal whole process group */
    1381           8 :     kill(-MyProcPid, SIGINT);
    1382             : #endif
    1383           8 :     kill(MyProcPid, SIGINT);
    1384           8 : }
    1385             : 
    1386             : static void
    1387           2 : TransactionTimeoutHandler(void)
    1388             : {
    1389           2 :     TransactionTimeoutPending = true;
    1390           2 :     InterruptPending = true;
    1391           2 :     SetLatch(MyLatch);
    1392           2 : }
    1393             : 
    1394             : static void
    1395           2 : IdleInTransactionSessionTimeoutHandler(void)
    1396             : {
    1397           2 :     IdleInTransactionSessionTimeoutPending = true;
    1398           2 :     InterruptPending = true;
    1399           2 :     SetLatch(MyLatch);
    1400           2 : }
    1401             : 
    1402             : static void
    1403           2 : IdleSessionTimeoutHandler(void)
    1404             : {
    1405           2 :     IdleSessionTimeoutPending = true;
    1406           2 :     InterruptPending = true;
    1407           2 :     SetLatch(MyLatch);
    1408           2 : }
    1409             : 
    1410             : static void
    1411          26 : IdleStatsUpdateTimeoutHandler(void)
    1412             : {
    1413          26 :     IdleStatsUpdateTimeoutPending = true;
    1414          26 :     InterruptPending = true;
    1415          26 :     SetLatch(MyLatch);
    1416          26 : }
    1417             : 
    1418             : static void
    1419           0 : ClientCheckTimeoutHandler(void)
    1420             : {
    1421           0 :     CheckClientConnectionPending = true;
    1422           0 :     InterruptPending = true;
    1423           0 :     SetLatch(MyLatch);
    1424           0 : }
    1425             : 
    1426             : /*
    1427             :  * Returns true if at least one role is defined in this database cluster.
    1428             :  */
    1429             : static bool
    1430         108 : ThereIsAtLeastOneRole(void)
    1431             : {
    1432             :     Relation    pg_authid_rel;
    1433             :     TableScanDesc scan;
    1434             :     bool        result;
    1435             : 
    1436         108 :     pg_authid_rel = table_open(AuthIdRelationId, AccessShareLock);
    1437             : 
    1438         108 :     scan = table_beginscan_catalog(pg_authid_rel, 0, NULL);
    1439         108 :     result = (heap_getnext(scan, ForwardScanDirection) != NULL);
    1440             : 
    1441         108 :     table_endscan(scan);
    1442         108 :     table_close(pg_authid_rel, AccessShareLock);
    1443             : 
    1444         108 :     return result;
    1445             : }

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