Line data Source code
1 : /*-------------------------------------------------------------------------
2 : *
3 : * postmaster.c
4 : * This program acts as a clearing house for requests to the
5 : * POSTGRES system. Frontend programs send a startup message
6 : * to the Postmaster and the postmaster uses the info in the
7 : * message to setup a backend process.
8 : *
9 : * The postmaster also manages system-wide operations such as
10 : * startup and shutdown. The postmaster itself doesn't do those
11 : * operations, mind you --- it just forks off a subprocess to do them
12 : * at the right times. It also takes care of resetting the system
13 : * if a backend crashes.
14 : *
15 : * The postmaster process creates the shared memory and semaphore
16 : * pools during startup, but as a rule does not touch them itself.
17 : * In particular, it is not a member of the PGPROC array of backends
18 : * and so it cannot participate in lock-manager operations. Keeping
19 : * the postmaster away from shared memory operations makes it simpler
20 : * and more reliable. The postmaster is almost always able to recover
21 : * from crashes of individual backends by resetting shared memory;
22 : * if it did much with shared memory then it would be prone to crashing
23 : * along with the backends.
24 : *
25 : * When a request message is received, we now fork() immediately.
26 : * The child process performs authentication of the request, and
27 : * then becomes a backend if successful. This allows the auth code
28 : * to be written in a simple single-threaded style (as opposed to the
29 : * crufty "poor man's multitasking" code that used to be needed).
30 : * More importantly, it ensures that blockages in non-multithreaded
31 : * libraries like SSL or PAM cannot cause denial of service to other
32 : * clients.
33 : *
34 : *
35 : * Portions Copyright (c) 1996-2019, PostgreSQL Global Development Group
36 : * Portions Copyright (c) 1994, Regents of the University of California
37 : *
38 : *
39 : * IDENTIFICATION
40 : * src/backend/postmaster/postmaster.c
41 : *
42 : * NOTES
43 : *
44 : * Initialization:
45 : * The Postmaster sets up shared memory data structures
46 : * for the backends.
47 : *
48 : * Synchronization:
49 : * The Postmaster shares memory with the backends but should avoid
50 : * touching shared memory, so as not to become stuck if a crashing
51 : * backend screws up locks or shared memory. Likewise, the Postmaster
52 : * should never block on messages from frontend clients.
53 : *
54 : * Garbage Collection:
55 : * The Postmaster cleans up after backends if they have an emergency
56 : * exit and/or core dump.
57 : *
58 : * Error Reporting:
59 : * Use write_stderr() only for reporting "interactive" errors
60 : * (essentially, bogus arguments on the command line). Once the
61 : * postmaster is launched, use ereport().
62 : *
63 : *-------------------------------------------------------------------------
64 : */
65 :
66 : #include "postgres.h"
67 :
68 : #include <unistd.h>
69 : #include <signal.h>
70 : #include <time.h>
71 : #include <sys/wait.h>
72 : #include <ctype.h>
73 : #include <sys/stat.h>
74 : #include <sys/socket.h>
75 : #include <fcntl.h>
76 : #include <sys/param.h>
77 : #include <netdb.h>
78 : #include <limits.h>
79 :
80 : #ifdef HAVE_SYS_SELECT_H
81 : #include <sys/select.h>
82 : #endif
83 :
84 : #ifdef USE_BONJOUR
85 : #include <dns_sd.h>
86 : #endif
87 :
88 : #ifdef USE_SYSTEMD
89 : #include <systemd/sd-daemon.h>
90 : #endif
91 :
92 : #ifdef HAVE_PTHREAD_IS_THREADED_NP
93 : #include <pthread.h>
94 : #endif
95 :
96 : #include "access/transam.h"
97 : #include "access/xlog.h"
98 : #include "bootstrap/bootstrap.h"
99 : #include "catalog/pg_control.h"
100 : #include "common/file_perm.h"
101 : #include "common/ip.h"
102 : #include "common/string.h"
103 : #include "lib/ilist.h"
104 : #include "libpq/auth.h"
105 : #include "libpq/libpq.h"
106 : #include "libpq/pqformat.h"
107 : #include "libpq/pqsignal.h"
108 : #include "miscadmin.h"
109 : #include "pg_getopt.h"
110 : #include "pgstat.h"
111 : #include "port/pg_bswap.h"
112 : #include "postmaster/autovacuum.h"
113 : #include "postmaster/bgworker_internals.h"
114 : #include "postmaster/fork_process.h"
115 : #include "postmaster/pgarch.h"
116 : #include "postmaster/postmaster.h"
117 : #include "postmaster/syslogger.h"
118 : #include "replication/logicallauncher.h"
119 : #include "replication/walsender.h"
120 : #include "storage/fd.h"
121 : #include "storage/ipc.h"
122 : #include "storage/pg_shmem.h"
123 : #include "storage/pmsignal.h"
124 : #include "storage/proc.h"
125 : #include "tcop/tcopprot.h"
126 : #include "utils/builtins.h"
127 : #include "utils/datetime.h"
128 : #include "utils/memutils.h"
129 : #include "utils/pidfile.h"
130 : #include "utils/ps_status.h"
131 : #include "utils/timeout.h"
132 : #include "utils/timestamp.h"
133 : #include "utils/varlena.h"
134 :
135 : #ifdef EXEC_BACKEND
136 : #include "storage/spin.h"
137 : #endif
138 :
139 :
140 : /*
141 : * Possible types of a backend. Beyond being the possible bkend_type values in
142 : * struct bkend, these are OR-able request flag bits for SignalSomeChildren()
143 : * and CountChildren().
144 : */
145 : #define BACKEND_TYPE_NORMAL 0x0001 /* normal backend */
146 : #define BACKEND_TYPE_AUTOVAC 0x0002 /* autovacuum worker process */
147 : #define BACKEND_TYPE_WALSND 0x0004 /* walsender process */
148 : #define BACKEND_TYPE_BGWORKER 0x0008 /* bgworker process */
149 : #define BACKEND_TYPE_ALL 0x000F /* OR of all the above */
150 :
151 : #define BACKEND_TYPE_WORKER (BACKEND_TYPE_AUTOVAC | BACKEND_TYPE_BGWORKER)
152 :
153 : /*
154 : * List of active backends (or child processes anyway; we don't actually
155 : * know whether a given child has become a backend or is still in the
156 : * authorization phase). This is used mainly to keep track of how many
157 : * children we have and send them appropriate signals when necessary.
158 : *
159 : * "Special" children such as the startup, bgwriter and autovacuum launcher
160 : * tasks are not in this list. Autovacuum worker and walsender are in it.
161 : * Also, "dead_end" children are in it: these are children launched just for
162 : * the purpose of sending a friendly rejection message to a would-be client.
163 : * We must track them because they are attached to shared memory, but we know
164 : * they will never become live backends. dead_end children are not assigned a
165 : * PMChildSlot.
166 : *
167 : * Background workers are in this list, too.
168 : */
169 : typedef struct bkend
170 : {
171 : pid_t pid; /* process id of backend */
172 : int32 cancel_key; /* cancel key for cancels for this backend */
173 : int child_slot; /* PMChildSlot for this backend, if any */
174 :
175 : /*
176 : * Flavor of backend or auxiliary process. Note that BACKEND_TYPE_WALSND
177 : * backends initially announce themselves as BACKEND_TYPE_NORMAL, so if
178 : * bkend_type is normal, you should check for a recent transition.
179 : */
180 : int bkend_type;
181 : bool dead_end; /* is it going to send an error and quit? */
182 : bool bgworker_notify; /* gets bgworker start/stop notifications */
183 : dlist_node elem; /* list link in BackendList */
184 : } Backend;
185 :
186 : static dlist_head BackendList = DLIST_STATIC_INIT(BackendList);
187 :
188 : #ifdef EXEC_BACKEND
189 : static Backend *ShmemBackendArray;
190 : #endif
191 :
192 : BackgroundWorker *MyBgworkerEntry = NULL;
193 :
194 :
195 :
196 : /* The socket number we are listening for connections on */
197 : int PostPortNumber;
198 :
199 : /* The directory names for Unix socket(s) */
200 : char *Unix_socket_directories;
201 :
202 : /* The TCP listen address(es) */
203 : char *ListenAddresses;
204 :
205 : /*
206 : * ReservedBackends is the number of backends reserved for superuser use.
207 : * This number is taken out of the pool size given by MaxConnections so
208 : * number of backend slots available to non-superusers is
209 : * (MaxConnections - ReservedBackends). Note what this really means is
210 : * "if there are <= ReservedBackends connections available, only superusers
211 : * can make new connections" --- pre-existing superuser connections don't
212 : * count against the limit.
213 : */
214 : int ReservedBackends;
215 :
216 : /* The socket(s) we're listening to. */
217 : #define MAXLISTEN 64
218 : static pgsocket ListenSocket[MAXLISTEN];
219 :
220 : /*
221 : * Set by the -o option
222 : */
223 : static char ExtraOptions[MAXPGPATH];
224 :
225 : /*
226 : * These globals control the behavior of the postmaster in case some
227 : * backend dumps core. Normally, it kills all peers of the dead backend
228 : * and reinitializes shared memory. By specifying -s or -n, we can have
229 : * the postmaster stop (rather than kill) peers and not reinitialize
230 : * shared data structures. (Reinit is currently dead code, though.)
231 : */
232 : static bool Reinit = true;
233 : static int SendStop = false;
234 :
235 : /* still more option variables */
236 : bool EnableSSL = false;
237 :
238 : int PreAuthDelay = 0;
239 : int AuthenticationTimeout = 60;
240 :
241 : bool log_hostname; /* for ps display and logging */
242 : bool Log_connections = false;
243 : bool Db_user_namespace = false;
244 :
245 : bool enable_bonjour = false;
246 : char *bonjour_name;
247 : bool restart_after_crash = true;
248 :
249 : /* PIDs of special child processes; 0 when not running */
250 : static pid_t StartupPID = 0,
251 : BgWriterPID = 0,
252 : CheckpointerPID = 0,
253 : WalWriterPID = 0,
254 : WalReceiverPID = 0,
255 : AutoVacPID = 0,
256 : PgArchPID = 0,
257 : PgStatPID = 0,
258 : SysLoggerPID = 0;
259 :
260 : /* Startup process's status */
261 : typedef enum
262 : {
263 : STARTUP_NOT_RUNNING,
264 : STARTUP_RUNNING,
265 : STARTUP_SIGNALED, /* we sent it a SIGQUIT or SIGKILL */
266 : STARTUP_CRASHED
267 : } StartupStatusEnum;
268 :
269 : static StartupStatusEnum StartupStatus = STARTUP_NOT_RUNNING;
270 :
271 : /* Startup/shutdown state */
272 : #define NoShutdown 0
273 : #define SmartShutdown 1
274 : #define FastShutdown 2
275 : #define ImmediateShutdown 3
276 :
277 : static int Shutdown = NoShutdown;
278 :
279 : static bool FatalError = false; /* T if recovering from backend crash */
280 :
281 : /*
282 : * We use a simple state machine to control startup, shutdown, and
283 : * crash recovery (which is rather like shutdown followed by startup).
284 : *
285 : * After doing all the postmaster initialization work, we enter PM_STARTUP
286 : * state and the startup process is launched. The startup process begins by
287 : * reading the control file and other preliminary initialization steps.
288 : * In a normal startup, or after crash recovery, the startup process exits
289 : * with exit code 0 and we switch to PM_RUN state. However, archive recovery
290 : * is handled specially since it takes much longer and we would like to support
291 : * hot standby during archive recovery.
292 : *
293 : * When the startup process is ready to start archive recovery, it signals the
294 : * postmaster, and we switch to PM_RECOVERY state. The background writer and
295 : * checkpointer are launched, while the startup process continues applying WAL.
296 : * If Hot Standby is enabled, then, after reaching a consistent point in WAL
297 : * redo, startup process signals us again, and we switch to PM_HOT_STANDBY
298 : * state and begin accepting connections to perform read-only queries. When
299 : * archive recovery is finished, the startup process exits with exit code 0
300 : * and we switch to PM_RUN state.
301 : *
302 : * Normal child backends can only be launched when we are in PM_RUN or
303 : * PM_HOT_STANDBY state. (We also allow launch of normal
304 : * child backends in PM_WAIT_BACKUP state, but only for superusers.)
305 : * In other states we handle connection requests by launching "dead_end"
306 : * child processes, which will simply send the client an error message and
307 : * quit. (We track these in the BackendList so that we can know when they
308 : * are all gone; this is important because they're still connected to shared
309 : * memory, and would interfere with an attempt to destroy the shmem segment,
310 : * possibly leading to SHMALL failure when we try to make a new one.)
311 : * In PM_WAIT_DEAD_END state we are waiting for all the dead_end children
312 : * to drain out of the system, and therefore stop accepting connection
313 : * requests at all until the last existing child has quit (which hopefully
314 : * will not be very long).
315 : *
316 : * Notice that this state variable does not distinguish *why* we entered
317 : * states later than PM_RUN --- Shutdown and FatalError must be consulted
318 : * to find that out. FatalError is never true in PM_RECOVERY_* or PM_RUN
319 : * states, nor in PM_SHUTDOWN states (because we don't enter those states
320 : * when trying to recover from a crash). It can be true in PM_STARTUP state,
321 : * because we don't clear it until we've successfully started WAL redo.
322 : */
323 : typedef enum
324 : {
325 : PM_INIT, /* postmaster starting */
326 : PM_STARTUP, /* waiting for startup subprocess */
327 : PM_RECOVERY, /* in archive recovery mode */
328 : PM_HOT_STANDBY, /* in hot standby mode */
329 : PM_RUN, /* normal "database is alive" state */
330 : PM_WAIT_BACKUP, /* waiting for online backup mode to end */
331 : PM_WAIT_READONLY, /* waiting for read only backends to exit */
332 : PM_WAIT_BACKENDS, /* waiting for live backends to exit */
333 : PM_SHUTDOWN, /* waiting for checkpointer to do shutdown
334 : * ckpt */
335 : PM_SHUTDOWN_2, /* waiting for archiver and walsenders to
336 : * finish */
337 : PM_WAIT_DEAD_END, /* waiting for dead_end children to exit */
338 : PM_NO_CHILDREN /* all important children have exited */
339 : } PMState;
340 :
341 : static PMState pmState = PM_INIT;
342 :
343 : /* Start time of SIGKILL timeout during immediate shutdown or child crash */
344 : /* Zero means timeout is not running */
345 : static time_t AbortStartTime = 0;
346 :
347 : /* Length of said timeout */
348 : #define SIGKILL_CHILDREN_AFTER_SECS 5
349 :
350 : static bool ReachedNormalRunning = false; /* T if we've reached PM_RUN */
351 :
352 : bool ClientAuthInProgress = false; /* T during new-client
353 : * authentication */
354 :
355 : bool redirection_done = false; /* stderr redirected for syslogger? */
356 :
357 : /* received START_AUTOVAC_LAUNCHER signal */
358 : static volatile sig_atomic_t start_autovac_launcher = false;
359 :
360 : /* the launcher needs to be signalled to communicate some condition */
361 : static volatile bool avlauncher_needs_signal = false;
362 :
363 : /* received START_WALRECEIVER signal */
364 : static volatile sig_atomic_t WalReceiverRequested = false;
365 :
366 : /* set when there's a worker that needs to be started up */
367 : static volatile bool StartWorkerNeeded = true;
368 : static volatile bool HaveCrashedWorker = false;
369 :
370 : #ifdef USE_SSL
371 : /* Set when and if SSL has been initialized properly */
372 : static bool LoadedSSL = false;
373 : #endif
374 :
375 : #ifdef USE_BONJOUR
376 : static DNSServiceRef bonjour_sdref = NULL;
377 : #endif
378 :
379 : /*
380 : * postmaster.c - function prototypes
381 : */
382 : static void CloseServerPorts(int status, Datum arg);
383 : static void unlink_external_pid_file(int status, Datum arg);
384 : static void getInstallationPaths(const char *argv0);
385 : static void checkControlFile(void);
386 : static Port *ConnCreate(int serverFd);
387 : static void ConnFree(Port *port);
388 : static void reset_shared(int port);
389 : static void SIGHUP_handler(SIGNAL_ARGS);
390 : static void pmdie(SIGNAL_ARGS);
391 : static void reaper(SIGNAL_ARGS);
392 : static void sigusr1_handler(SIGNAL_ARGS);
393 : static void startup_die(SIGNAL_ARGS);
394 : static void dummy_handler(SIGNAL_ARGS);
395 : static void StartupPacketTimeoutHandler(void);
396 : static void CleanupBackend(int pid, int exitstatus);
397 : static bool CleanupBackgroundWorker(int pid, int exitstatus);
398 : static void HandleChildCrash(int pid, int exitstatus, const char *procname);
399 : static void LogChildExit(int lev, const char *procname,
400 : int pid, int exitstatus);
401 : static void PostmasterStateMachine(void);
402 : static void BackendInitialize(Port *port);
403 : static void BackendRun(Port *port) pg_attribute_noreturn();
404 : static void ExitPostmaster(int status) pg_attribute_noreturn();
405 : static int ServerLoop(void);
406 : static int BackendStartup(Port *port);
407 : static int ProcessStartupPacket(Port *port, bool secure_done);
408 : static void SendNegotiateProtocolVersion(List *unrecognized_protocol_options);
409 : static void processCancelRequest(Port *port, void *pkt);
410 : static int initMasks(fd_set *rmask);
411 : static void report_fork_failure_to_client(Port *port, int errnum);
412 : static CAC_state canAcceptConnections(void);
413 : static bool RandomCancelKey(int32 *cancel_key);
414 : static void signal_child(pid_t pid, int signal);
415 : static bool SignalSomeChildren(int signal, int targets);
416 : static void TerminateChildren(int signal);
417 :
418 : #define SignalChildren(sig) SignalSomeChildren(sig, BACKEND_TYPE_ALL)
419 :
420 : static int CountChildren(int target);
421 : static bool assign_backendlist_entry(RegisteredBgWorker *rw);
422 : static void maybe_start_bgworkers(void);
423 : static bool CreateOptsFile(int argc, char *argv[], char *fullprogname);
424 : static pid_t StartChildProcess(AuxProcType type);
425 : static void StartAutovacuumWorker(void);
426 : static void MaybeStartWalReceiver(void);
427 : static void InitPostmasterDeathWatchHandle(void);
428 :
429 : /*
430 : * Archiver is allowed to start up at the current postmaster state?
431 : *
432 : * If WAL archiving is enabled always, we are allowed to start archiver
433 : * even during recovery.
434 : */
435 : #define PgArchStartupAllowed() \
436 : ((XLogArchivingActive() && pmState == PM_RUN) || \
437 : (XLogArchivingAlways() && \
438 : (pmState == PM_RECOVERY || pmState == PM_HOT_STANDBY)))
439 :
440 : #ifdef EXEC_BACKEND
441 :
442 : #ifdef WIN32
443 : #define WNOHANG 0 /* ignored, so any integer value will do */
444 :
445 : static pid_t waitpid(pid_t pid, int *exitstatus, int options);
446 : static void WINAPI pgwin32_deadchild_callback(PVOID lpParameter, BOOLEAN TimerOrWaitFired);
447 :
448 : static HANDLE win32ChildQueue;
449 :
450 : typedef struct
451 : {
452 : HANDLE waitHandle;
453 : HANDLE procHandle;
454 : DWORD procId;
455 : } win32_deadchild_waitinfo;
456 : #endif /* WIN32 */
457 :
458 : static pid_t backend_forkexec(Port *port);
459 : static pid_t internal_forkexec(int argc, char *argv[], Port *port);
460 :
461 : /* Type for a socket that can be inherited to a client process */
462 : #ifdef WIN32
463 : typedef struct
464 : {
465 : SOCKET origsocket; /* Original socket value, or PGINVALID_SOCKET
466 : * if not a socket */
467 : WSAPROTOCOL_INFO wsainfo;
468 : } InheritableSocket;
469 : #else
470 : typedef int InheritableSocket;
471 : #endif
472 :
473 : /*
474 : * Structure contains all variables passed to exec:ed backends
475 : */
476 : typedef struct
477 : {
478 : Port port;
479 : InheritableSocket portsocket;
480 : char DataDir[MAXPGPATH];
481 : pgsocket ListenSocket[MAXLISTEN];
482 : int32 MyCancelKey;
483 : int MyPMChildSlot;
484 : #ifndef WIN32
485 : unsigned long UsedShmemSegID;
486 : #else
487 : void *ShmemProtectiveRegion;
488 : HANDLE UsedShmemSegID;
489 : #endif
490 : void *UsedShmemSegAddr;
491 : slock_t *ShmemLock;
492 : VariableCache ShmemVariableCache;
493 : Backend *ShmemBackendArray;
494 : #ifndef HAVE_SPINLOCKS
495 : PGSemaphore *SpinlockSemaArray;
496 : #endif
497 : int NamedLWLockTrancheRequests;
498 : NamedLWLockTranche *NamedLWLockTrancheArray;
499 : LWLockPadded *MainLWLockArray;
500 : slock_t *ProcStructLock;
501 : PROC_HDR *ProcGlobal;
502 : PGPROC *AuxiliaryProcs;
503 : PGPROC *PreparedXactProcs;
504 : PMSignalData *PMSignalState;
505 : InheritableSocket pgStatSock;
506 : pid_t PostmasterPid;
507 : TimestampTz PgStartTime;
508 : TimestampTz PgReloadTime;
509 : pg_time_t first_syslogger_file_time;
510 : bool redirection_done;
511 : bool IsBinaryUpgrade;
512 : int max_safe_fds;
513 : int MaxBackends;
514 : #ifdef WIN32
515 : HANDLE PostmasterHandle;
516 : HANDLE initial_signal_pipe;
517 : HANDLE syslogPipe[2];
518 : #else
519 : int postmaster_alive_fds[2];
520 : int syslogPipe[2];
521 : #endif
522 : char my_exec_path[MAXPGPATH];
523 : char pkglib_path[MAXPGPATH];
524 : char ExtraOptions[MAXPGPATH];
525 : } BackendParameters;
526 :
527 : static void read_backend_variables(char *id, Port *port);
528 : static void restore_backend_variables(BackendParameters *param, Port *port);
529 :
530 : #ifndef WIN32
531 : static bool save_backend_variables(BackendParameters *param, Port *port);
532 : #else
533 : static bool save_backend_variables(BackendParameters *param, Port *port,
534 : HANDLE childProcess, pid_t childPid);
535 : #endif
536 :
537 : static void ShmemBackendArrayAdd(Backend *bn);
538 : static void ShmemBackendArrayRemove(Backend *bn);
539 : #endif /* EXEC_BACKEND */
540 :
541 : #define StartupDataBase() StartChildProcess(StartupProcess)
542 : #define StartBackgroundWriter() StartChildProcess(BgWriterProcess)
543 : #define StartCheckpointer() StartChildProcess(CheckpointerProcess)
544 : #define StartWalWriter() StartChildProcess(WalWriterProcess)
545 : #define StartWalReceiver() StartChildProcess(WalReceiverProcess)
546 :
547 : /* Macros to check exit status of a child process */
548 : #define EXIT_STATUS_0(st) ((st) == 0)
549 : #define EXIT_STATUS_1(st) (WIFEXITED(st) && WEXITSTATUS(st) == 1)
550 : #define EXIT_STATUS_3(st) (WIFEXITED(st) && WEXITSTATUS(st) == 3)
551 :
552 : #ifndef WIN32
553 : /*
554 : * File descriptors for pipe used to monitor if postmaster is alive.
555 : * First is POSTMASTER_FD_WATCH, second is POSTMASTER_FD_OWN.
556 : */
557 : int postmaster_alive_fds[2] = {-1, -1};
558 : #else
559 : /* Process handle of postmaster used for the same purpose on Windows */
560 : HANDLE PostmasterHandle;
561 : #endif
562 :
563 : /*
564 : * Postmaster main entry point
565 : */
566 : void
567 580 : PostmasterMain(int argc, char *argv[])
568 : {
569 : int opt;
570 : int status;
571 580 : char *userDoption = NULL;
572 580 : bool listen_addr_saved = false;
573 : int i;
574 580 : char *output_config_variable = NULL;
575 :
576 580 : InitProcessGlobals();
577 :
578 580 : PostmasterPid = MyProcPid;
579 :
580 580 : IsPostmasterEnvironment = true;
581 :
582 : /*
583 : * We should not be creating any files or directories before we check the
584 : * data directory (see checkDataDir()), but just in case set the umask to
585 : * the most restrictive (owner-only) permissions.
586 : *
587 : * checkDataDir() will reset the umask based on the data directory
588 : * permissions.
589 : */
590 580 : umask(PG_MODE_MASK_OWNER);
591 :
592 : /*
593 : * By default, palloc() requests in the postmaster will be allocated in
594 : * the PostmasterContext, which is space that can be recycled by backends.
595 : * Allocated data that needs to be available to backends should be
596 : * allocated in TopMemoryContext.
597 : */
598 580 : PostmasterContext = AllocSetContextCreate(TopMemoryContext,
599 : "Postmaster",
600 : ALLOCSET_DEFAULT_SIZES);
601 580 : MemoryContextSwitchTo(PostmasterContext);
602 :
603 : /* Initialize paths to installation files */
604 580 : getInstallationPaths(argv[0]);
605 :
606 : /*
607 : * Set up signal handlers for the postmaster process.
608 : *
609 : * In the postmaster, we want to install non-ignored handlers *without*
610 : * SA_RESTART. This is because they'll be blocked at all times except
611 : * when ServerLoop is waiting for something to happen, and during that
612 : * window, we want signals to exit the select(2) wait so that ServerLoop
613 : * can respond if anything interesting happened. On some platforms,
614 : * signals marked SA_RESTART would not cause the select() wait to end.
615 : * Child processes will generally want SA_RESTART, but we expect them to
616 : * set up their own handlers before unblocking signals.
617 : *
618 : * CAUTION: when changing this list, check for side-effects on the signal
619 : * handling setup of child processes. See tcop/postgres.c,
620 : * bootstrap/bootstrap.c, postmaster/bgwriter.c, postmaster/walwriter.c,
621 : * postmaster/autovacuum.c, postmaster/pgarch.c, postmaster/pgstat.c,
622 : * postmaster/syslogger.c, postmaster/bgworker.c and
623 : * postmaster/checkpointer.c.
624 : */
625 580 : pqinitmask();
626 580 : PG_SETMASK(&BlockSig);
627 :
628 580 : pqsignal_no_restart(SIGHUP, SIGHUP_handler); /* reread config file and
629 : * have children do same */
630 580 : pqsignal_no_restart(SIGINT, pmdie); /* send SIGTERM and shut down */
631 580 : pqsignal_no_restart(SIGQUIT, pmdie); /* send SIGQUIT and die */
632 580 : pqsignal_no_restart(SIGTERM, pmdie); /* wait for children and shut down */
633 580 : pqsignal(SIGALRM, SIG_IGN); /* ignored */
634 580 : pqsignal(SIGPIPE, SIG_IGN); /* ignored */
635 580 : pqsignal_no_restart(SIGUSR1, sigusr1_handler); /* message from child
636 : * process */
637 580 : pqsignal_no_restart(SIGUSR2, dummy_handler); /* unused, reserve for
638 : * children */
639 580 : pqsignal_no_restart(SIGCHLD, reaper); /* handle child termination */
640 :
641 : /*
642 : * No other place in Postgres should touch SIGTTIN/SIGTTOU handling. We
643 : * ignore those signals in a postmaster environment, so that there is no
644 : * risk of a child process freezing up due to writing to stderr. But for
645 : * a standalone backend, their default handling is reasonable. Hence, all
646 : * child processes should just allow the inherited settings to stand.
647 : */
648 : #ifdef SIGTTIN
649 580 : pqsignal(SIGTTIN, SIG_IGN); /* ignored */
650 : #endif
651 : #ifdef SIGTTOU
652 580 : pqsignal(SIGTTOU, SIG_IGN); /* ignored */
653 : #endif
654 :
655 : /* ignore SIGXFSZ, so that ulimit violations work like disk full */
656 : #ifdef SIGXFSZ
657 580 : pqsignal(SIGXFSZ, SIG_IGN); /* ignored */
658 : #endif
659 :
660 : /*
661 : * Options setup
662 : */
663 580 : InitializeGUCOptions();
664 :
665 580 : opterr = 1;
666 :
667 : /*
668 : * Parse command-line options. CAUTION: keep this in sync with
669 : * tcop/postgres.c (the option sets should not conflict) and with the
670 : * common help() function in main/main.c.
671 : */
672 2602 : while ((opt = getopt(argc, argv, "B:bc:C:D:d:EeFf:h:ijk:lN:nOo:Pp:r:S:sTt:W:-:")) != -1)
673 : {
674 1442 : switch (opt)
675 : {
676 : case 'B':
677 0 : SetConfigOption("shared_buffers", optarg, PGC_POSTMASTER, PGC_S_ARGV);
678 0 : break;
679 :
680 : case 'b':
681 : /* Undocumented flag used for binary upgrades */
682 8 : IsBinaryUpgrade = true;
683 8 : break;
684 :
685 : case 'C':
686 0 : output_config_variable = strdup(optarg);
687 0 : break;
688 :
689 : case 'D':
690 576 : userDoption = strdup(optarg);
691 576 : break;
692 :
693 : case 'd':
694 0 : set_debug_options(atoi(optarg), PGC_POSTMASTER, PGC_S_ARGV);
695 0 : break;
696 :
697 : case 'E':
698 0 : SetConfigOption("log_statement", "all", PGC_POSTMASTER, PGC_S_ARGV);
699 0 : break;
700 :
701 : case 'e':
702 0 : SetConfigOption("datestyle", "euro", PGC_POSTMASTER, PGC_S_ARGV);
703 0 : break;
704 :
705 : case 'F':
706 128 : SetConfigOption("fsync", "false", PGC_POSTMASTER, PGC_S_ARGV);
707 128 : break;
708 :
709 : case 'f':
710 0 : if (!set_plan_disabling_options(optarg, PGC_POSTMASTER, PGC_S_ARGV))
711 : {
712 0 : write_stderr("%s: invalid argument for option -f: \"%s\"\n",
713 : progname, optarg);
714 0 : ExitPostmaster(1);
715 : }
716 0 : break;
717 :
718 : case 'h':
719 0 : SetConfigOption("listen_addresses", optarg, PGC_POSTMASTER, PGC_S_ARGV);
720 0 : break;
721 :
722 : case 'i':
723 0 : SetConfigOption("listen_addresses", "*", PGC_POSTMASTER, PGC_S_ARGV);
724 0 : break;
725 :
726 : case 'j':
727 : /* only used by interactive backend */
728 0 : break;
729 :
730 : case 'k':
731 128 : SetConfigOption("unix_socket_directories", optarg, PGC_POSTMASTER, PGC_S_ARGV);
732 128 : break;
733 :
734 : case 'l':
735 0 : SetConfigOption("ssl", "true", PGC_POSTMASTER, PGC_S_ARGV);
736 0 : break;
737 :
738 : case 'N':
739 0 : SetConfigOption("max_connections", optarg, PGC_POSTMASTER, PGC_S_ARGV);
740 0 : break;
741 :
742 : case 'n':
743 : /* Don't reinit shared mem after abnormal exit */
744 0 : Reinit = false;
745 0 : break;
746 :
747 : case 'O':
748 0 : SetConfigOption("allow_system_table_mods", "true", PGC_POSTMASTER, PGC_S_ARGV);
749 0 : break;
750 :
751 : case 'o':
752 : /* Other options to pass to the backend on the command line */
753 0 : snprintf(ExtraOptions + strlen(ExtraOptions),
754 0 : sizeof(ExtraOptions) - strlen(ExtraOptions),
755 : " %s", optarg);
756 0 : break;
757 :
758 : case 'P':
759 0 : SetConfigOption("ignore_system_indexes", "true", PGC_POSTMASTER, PGC_S_ARGV);
760 0 : break;
761 :
762 : case 'p':
763 8 : SetConfigOption("port", optarg, PGC_POSTMASTER, PGC_S_ARGV);
764 8 : break;
765 :
766 : case 'r':
767 : /* only used by single-user backend */
768 0 : break;
769 :
770 : case 'S':
771 0 : SetConfigOption("work_mem", optarg, PGC_POSTMASTER, PGC_S_ARGV);
772 0 : break;
773 :
774 : case 's':
775 0 : SetConfigOption("log_statement_stats", "true", PGC_POSTMASTER, PGC_S_ARGV);
776 0 : break;
777 :
778 : case 'T':
779 :
780 : /*
781 : * In the event that some backend dumps core, send SIGSTOP,
782 : * rather than SIGQUIT, to all its peers. This lets the wily
783 : * post_hacker collect core dumps from everyone.
784 : */
785 0 : SendStop = true;
786 0 : break;
787 :
788 : case 't':
789 : {
790 0 : const char *tmp = get_stats_option_name(optarg);
791 :
792 0 : if (tmp)
793 : {
794 0 : SetConfigOption(tmp, "true", PGC_POSTMASTER, PGC_S_ARGV);
795 : }
796 : else
797 : {
798 0 : write_stderr("%s: invalid argument for option -t: \"%s\"\n",
799 : progname, optarg);
800 0 : ExitPostmaster(1);
801 : }
802 0 : break;
803 : }
804 :
805 : case 'W':
806 0 : SetConfigOption("post_auth_delay", optarg, PGC_POSTMASTER, PGC_S_ARGV);
807 0 : break;
808 :
809 : case 'c':
810 : case '-':
811 : {
812 : char *name,
813 : *value;
814 :
815 594 : ParseLongOption(optarg, &name, &value);
816 594 : if (!value)
817 : {
818 0 : if (opt == '-')
819 0 : ereport(ERROR,
820 : (errcode(ERRCODE_SYNTAX_ERROR),
821 : errmsg("--%s requires a value",
822 : optarg)));
823 : else
824 0 : ereport(ERROR,
825 : (errcode(ERRCODE_SYNTAX_ERROR),
826 : errmsg("-c %s requires a value",
827 : optarg)));
828 : }
829 :
830 594 : SetConfigOption(name, value, PGC_POSTMASTER, PGC_S_ARGV);
831 594 : free(name);
832 594 : if (value)
833 594 : free(value);
834 594 : break;
835 : }
836 :
837 : default:
838 0 : write_stderr("Try \"%s --help\" for more information.\n",
839 : progname);
840 0 : ExitPostmaster(1);
841 : }
842 : }
843 :
844 : /*
845 : * Postmaster accepts no non-option switch arguments.
846 : */
847 580 : if (optind < argc)
848 : {
849 0 : write_stderr("%s: invalid argument: \"%s\"\n",
850 0 : progname, argv[optind]);
851 0 : write_stderr("Try \"%s --help\" for more information.\n",
852 : progname);
853 0 : ExitPostmaster(1);
854 : }
855 :
856 : /*
857 : * Locate the proper configuration files and data directory, and read
858 : * postgresql.conf for the first time.
859 : */
860 580 : if (!SelectConfigFiles(userDoption, progname))
861 0 : ExitPostmaster(2);
862 :
863 578 : if (output_config_variable != NULL)
864 : {
865 : /*
866 : * "-C guc" was specified, so print GUC's value and exit. No extra
867 : * permission check is needed because the user is reading inside the
868 : * data dir.
869 : */
870 0 : const char *config_val = GetConfigOption(output_config_variable,
871 : false, false);
872 :
873 0 : puts(config_val ? config_val : "");
874 0 : ExitPostmaster(0);
875 : }
876 :
877 : /* Verify that DataDir looks reasonable */
878 578 : checkDataDir();
879 :
880 : /* Check that pg_control exists */
881 578 : checkControlFile();
882 :
883 : /* And switch working directory into it */
884 578 : ChangeToDataDir();
885 :
886 : /*
887 : * Check for invalid combinations of GUC settings.
888 : */
889 578 : if (ReservedBackends >= MaxConnections)
890 : {
891 0 : write_stderr("%s: superuser_reserved_connections (%d) must be less than max_connections (%d)\n",
892 : progname,
893 : ReservedBackends, MaxConnections);
894 0 : ExitPostmaster(1);
895 : }
896 578 : if (XLogArchiveMode > ARCHIVE_MODE_OFF && wal_level == WAL_LEVEL_MINIMAL)
897 0 : ereport(ERROR,
898 : (errmsg("WAL archival cannot be enabled when wal_level is \"minimal\"")));
899 578 : if (max_wal_senders > 0 && wal_level == WAL_LEVEL_MINIMAL)
900 0 : ereport(ERROR,
901 : (errmsg("WAL streaming (max_wal_senders > 0) requires wal_level \"replica\" or \"logical\"")));
902 :
903 : /*
904 : * Other one-time internal sanity checks can go here, if they are fast.
905 : * (Put any slow processing further down, after postmaster.pid creation.)
906 : */
907 578 : if (!CheckDateTokenTables())
908 : {
909 0 : write_stderr("%s: invalid datetoken tables, please fix\n", progname);
910 0 : ExitPostmaster(1);
911 : }
912 :
913 : /*
914 : * Now that we are done processing the postmaster arguments, reset
915 : * getopt(3) library so that it will work correctly in subprocesses.
916 : */
917 578 : optind = 1;
918 : #ifdef HAVE_INT_OPTRESET
919 : optreset = 1; /* some systems need this too */
920 : #endif
921 :
922 : /* For debugging: display postmaster environment */
923 : {
924 : extern char **environ;
925 : char **p;
926 :
927 578 : ereport(DEBUG3,
928 : (errmsg_internal("%s: PostmasterMain: initial environment dump:",
929 : progname)));
930 578 : ereport(DEBUG3,
931 : (errmsg_internal("-----------------------------------------")));
932 20388 : for (p = environ; *p; ++p)
933 19810 : ereport(DEBUG3,
934 : (errmsg_internal("\t%s", *p)));
935 578 : ereport(DEBUG3,
936 : (errmsg_internal("-----------------------------------------")));
937 : }
938 :
939 : /*
940 : * Create lockfile for data directory.
941 : *
942 : * We want to do this before we try to grab the input sockets, because the
943 : * data directory interlock is more reliable than the socket-file
944 : * interlock (thanks to whoever decided to put socket files in /tmp :-().
945 : * For the same reason, it's best to grab the TCP socket(s) before the
946 : * Unix socket(s).
947 : *
948 : * Also note that this internally sets up the on_proc_exit function that
949 : * is responsible for removing both data directory and socket lockfiles;
950 : * so it must happen before opening sockets so that at exit, the socket
951 : * lockfiles go away after CloseServerPorts runs.
952 : */
953 578 : CreateDataDirLockFile(true);
954 :
955 : /*
956 : * Read the control file (for error checking and config info).
957 : *
958 : * Since we verify the control file's CRC, this has a useful side effect
959 : * on machines where we need a run-time test for CRC support instructions.
960 : * The postmaster will do the test once at startup, and then its child
961 : * processes will inherit the correct function pointer and not need to
962 : * repeat the test.
963 : */
964 576 : LocalProcessControlFile(false);
965 :
966 : /*
967 : * Initialize SSL library, if specified.
968 : */
969 : #ifdef USE_SSL
970 576 : if (EnableSSL)
971 : {
972 20 : (void) secure_initialize(true);
973 18 : LoadedSSL = true;
974 : }
975 : #endif
976 :
977 : /*
978 : * Register the apply launcher. Since it registers a background worker,
979 : * it needs to be called before InitializeMaxBackends(), and it's probably
980 : * a good idea to call it before any modules had chance to take the
981 : * background worker slots.
982 : */
983 574 : ApplyLauncherRegister();
984 :
985 : /*
986 : * process any libraries that should be preloaded at postmaster start
987 : */
988 574 : process_shared_preload_libraries();
989 :
990 : /*
991 : * Now that loadable modules have had their chance to register background
992 : * workers, calculate MaxBackends.
993 : */
994 574 : InitializeMaxBackends();
995 :
996 : /* Report server startup in log */
997 574 : ereport(LOG,
998 : (errmsg("starting %s", PG_VERSION_STR)));
999 :
1000 : /*
1001 : * Establish input sockets.
1002 : *
1003 : * First, mark them all closed, and set up an on_proc_exit function that's
1004 : * charged with closing the sockets again at postmaster shutdown.
1005 : */
1006 37310 : for (i = 0; i < MAXLISTEN; i++)
1007 36736 : ListenSocket[i] = PGINVALID_SOCKET;
1008 :
1009 574 : on_proc_exit(CloseServerPorts, 0);
1010 :
1011 574 : if (ListenAddresses)
1012 : {
1013 : char *rawstring;
1014 : List *elemlist;
1015 : ListCell *l;
1016 574 : int success = 0;
1017 :
1018 : /* Need a modifiable copy of ListenAddresses */
1019 574 : rawstring = pstrdup(ListenAddresses);
1020 :
1021 : /* Parse string into list of hostnames */
1022 574 : if (!SplitIdentifierString(rawstring, ',', &elemlist))
1023 : {
1024 : /* syntax error in list */
1025 0 : ereport(FATAL,
1026 : (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
1027 : errmsg("invalid list syntax in parameter \"%s\"",
1028 : "listen_addresses")));
1029 : }
1030 :
1031 598 : foreach(l, elemlist)
1032 : {
1033 24 : char *curhost = (char *) lfirst(l);
1034 :
1035 24 : if (strcmp(curhost, "*") == 0)
1036 0 : status = StreamServerPort(AF_UNSPEC, NULL,
1037 0 : (unsigned short) PostPortNumber,
1038 : NULL,
1039 : ListenSocket, MAXLISTEN);
1040 : else
1041 24 : status = StreamServerPort(AF_UNSPEC, curhost,
1042 24 : (unsigned short) PostPortNumber,
1043 : NULL,
1044 : ListenSocket, MAXLISTEN);
1045 :
1046 24 : if (status == STATUS_OK)
1047 : {
1048 24 : success++;
1049 : /* record the first successful host addr in lockfile */
1050 24 : if (!listen_addr_saved)
1051 : {
1052 24 : AddToDataDirLockFile(LOCK_FILE_LINE_LISTEN_ADDR, curhost);
1053 24 : listen_addr_saved = true;
1054 : }
1055 : }
1056 : else
1057 0 : ereport(WARNING,
1058 : (errmsg("could not create listen socket for \"%s\"",
1059 : curhost)));
1060 : }
1061 :
1062 574 : if (!success && elemlist != NIL)
1063 0 : ereport(FATAL,
1064 : (errmsg("could not create any TCP/IP sockets")));
1065 :
1066 574 : list_free(elemlist);
1067 574 : pfree(rawstring);
1068 : }
1069 :
1070 : #ifdef USE_BONJOUR
1071 : /* Register for Bonjour only if we opened TCP socket(s) */
1072 : if (enable_bonjour && ListenSocket[0] != PGINVALID_SOCKET)
1073 : {
1074 : DNSServiceErrorType err;
1075 :
1076 : /*
1077 : * We pass 0 for interface_index, which will result in registering on
1078 : * all "applicable" interfaces. It's not entirely clear from the
1079 : * DNS-SD docs whether this would be appropriate if we have bound to
1080 : * just a subset of the available network interfaces.
1081 : */
1082 : err = DNSServiceRegister(&bonjour_sdref,
1083 : 0,
1084 : 0,
1085 : bonjour_name,
1086 : "_postgresql._tcp.",
1087 : NULL,
1088 : NULL,
1089 : pg_hton16(PostPortNumber),
1090 : 0,
1091 : NULL,
1092 : NULL,
1093 : NULL);
1094 : if (err != kDNSServiceErr_NoError)
1095 : elog(LOG, "DNSServiceRegister() failed: error code %ld",
1096 : (long) err);
1097 :
1098 : /*
1099 : * We don't bother to read the mDNS daemon's reply, and we expect that
1100 : * it will automatically terminate our registration when the socket is
1101 : * closed at postmaster termination. So there's nothing more to be
1102 : * done here. However, the bonjour_sdref is kept around so that
1103 : * forked children can close their copies of the socket.
1104 : */
1105 : }
1106 : #endif
1107 :
1108 : #ifdef HAVE_UNIX_SOCKETS
1109 574 : if (Unix_socket_directories)
1110 : {
1111 : char *rawstring;
1112 : List *elemlist;
1113 : ListCell *l;
1114 574 : int success = 0;
1115 :
1116 : /* Need a modifiable copy of Unix_socket_directories */
1117 574 : rawstring = pstrdup(Unix_socket_directories);
1118 :
1119 : /* Parse string into list of directories */
1120 574 : if (!SplitDirectoriesString(rawstring, ',', &elemlist))
1121 : {
1122 : /* syntax error in list */
1123 0 : ereport(FATAL,
1124 : (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
1125 : errmsg("invalid list syntax in parameter \"%s\"",
1126 : "unix_socket_directories")));
1127 : }
1128 :
1129 1146 : foreach(l, elemlist)
1130 : {
1131 572 : char *socketdir = (char *) lfirst(l);
1132 :
1133 572 : status = StreamServerPort(AF_UNIX, NULL,
1134 572 : (unsigned short) PostPortNumber,
1135 : socketdir,
1136 : ListenSocket, MAXLISTEN);
1137 :
1138 572 : if (status == STATUS_OK)
1139 : {
1140 572 : success++;
1141 : /* record the first successful Unix socket in lockfile */
1142 572 : if (success == 1)
1143 572 : AddToDataDirLockFile(LOCK_FILE_LINE_SOCKET_DIR, socketdir);
1144 : }
1145 : else
1146 0 : ereport(WARNING,
1147 : (errmsg("could not create Unix-domain socket in directory \"%s\"",
1148 : socketdir)));
1149 : }
1150 :
1151 574 : if (!success && elemlist != NIL)
1152 0 : ereport(FATAL,
1153 : (errmsg("could not create any Unix-domain sockets")));
1154 :
1155 574 : list_free_deep(elemlist);
1156 574 : pfree(rawstring);
1157 : }
1158 : #endif
1159 :
1160 : /*
1161 : * check that we have some socket to listen on
1162 : */
1163 574 : if (ListenSocket[0] == PGINVALID_SOCKET)
1164 0 : ereport(FATAL,
1165 : (errmsg("no socket created for listening")));
1166 :
1167 : /*
1168 : * If no valid TCP ports, write an empty line for listen address,
1169 : * indicating the Unix socket must be used. Note that this line is not
1170 : * added to the lock file until there is a socket backing it.
1171 : */
1172 574 : if (!listen_addr_saved)
1173 550 : AddToDataDirLockFile(LOCK_FILE_LINE_LISTEN_ADDR, "");
1174 :
1175 : /*
1176 : * Set up shared memory and semaphores.
1177 : */
1178 574 : reset_shared(PostPortNumber);
1179 :
1180 : /*
1181 : * Estimate number of openable files. This must happen after setting up
1182 : * semaphores, because on some platforms semaphores count as open files.
1183 : */
1184 572 : set_max_safe_fds();
1185 :
1186 : /*
1187 : * Set reference point for stack-depth checking.
1188 : */
1189 572 : set_stack_base();
1190 :
1191 : /*
1192 : * Initialize pipe (or process handle on Windows) that allows children to
1193 : * wake up from sleep on postmaster death.
1194 : */
1195 572 : InitPostmasterDeathWatchHandle();
1196 :
1197 : #ifdef WIN32
1198 :
1199 : /*
1200 : * Initialize I/O completion port used to deliver list of dead children.
1201 : */
1202 : win32ChildQueue = CreateIoCompletionPort(INVALID_HANDLE_VALUE, NULL, 0, 1);
1203 : if (win32ChildQueue == NULL)
1204 : ereport(FATAL,
1205 : (errmsg("could not create I/O completion port for child queue")));
1206 : #endif
1207 :
1208 : /*
1209 : * Record postmaster options. We delay this till now to avoid recording
1210 : * bogus options (eg, NBuffers too high for available memory).
1211 : */
1212 572 : if (!CreateOptsFile(argc, argv, my_exec_path))
1213 0 : ExitPostmaster(1);
1214 :
1215 : #ifdef EXEC_BACKEND
1216 : /* Write out nondefault GUC settings for child processes to use */
1217 : write_nondefault_variables(PGC_POSTMASTER);
1218 : #endif
1219 :
1220 : /*
1221 : * Write the external PID file if requested
1222 : */
1223 572 : if (external_pid_file)
1224 : {
1225 0 : FILE *fpidfile = fopen(external_pid_file, "w");
1226 :
1227 0 : if (fpidfile)
1228 : {
1229 0 : fprintf(fpidfile, "%d\n", MyProcPid);
1230 0 : fclose(fpidfile);
1231 :
1232 : /* Make PID file world readable */
1233 0 : if (chmod(external_pid_file, S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH) != 0)
1234 0 : write_stderr("%s: could not change permissions of external PID file \"%s\": %s\n",
1235 0 : progname, external_pid_file, strerror(errno));
1236 : }
1237 : else
1238 0 : write_stderr("%s: could not write external PID file \"%s\": %s\n",
1239 0 : progname, external_pid_file, strerror(errno));
1240 :
1241 0 : on_proc_exit(unlink_external_pid_file, 0);
1242 : }
1243 :
1244 : /*
1245 : * Remove old temporary files. At this point there can be no other
1246 : * Postgres processes running in this directory, so this should be safe.
1247 : */
1248 572 : RemovePgTempFiles();
1249 :
1250 : /*
1251 : * Forcibly remove the files signaling a standby promotion request.
1252 : * Otherwise, the existence of those files triggers a promotion too early,
1253 : * whether a user wants that or not.
1254 : *
1255 : * This removal of files is usually unnecessary because they can exist
1256 : * only during a few moments during a standby promotion. However there is
1257 : * a race condition: if pg_ctl promote is executed and creates the files
1258 : * during a promotion, the files can stay around even after the server is
1259 : * brought up to new master. Then, if new standby starts by using the
1260 : * backup taken from that master, the files can exist at the server
1261 : * startup and should be removed in order to avoid an unexpected
1262 : * promotion.
1263 : *
1264 : * Note that promotion signal files need to be removed before the startup
1265 : * process is invoked. Because, after that, they can be used by
1266 : * postmaster's SIGUSR1 signal handler.
1267 : */
1268 572 : RemovePromoteSignalFiles();
1269 :
1270 : /* Do the same for logrotate signal file */
1271 572 : RemoveLogrotateSignalFiles();
1272 :
1273 : /* Remove any outdated file holding the current log filenames. */
1274 572 : if (unlink(LOG_METAINFO_DATAFILE) < 0 && errno != ENOENT)
1275 0 : ereport(LOG,
1276 : (errcode_for_file_access(),
1277 : errmsg("could not remove file \"%s\": %m",
1278 : LOG_METAINFO_DATAFILE)));
1279 :
1280 : /*
1281 : * If enabled, start up syslogger collection subprocess
1282 : */
1283 572 : SysLoggerPID = SysLogger_Start();
1284 :
1285 : /*
1286 : * Reset whereToSendOutput from DestDebug (its starting state) to
1287 : * DestNone. This stops ereport from sending log messages to stderr unless
1288 : * Log_destination permits. We don't do this until the postmaster is
1289 : * fully launched, since startup failures may as well be reported to
1290 : * stderr.
1291 : *
1292 : * If we are in fact disabling logging to stderr, first emit a log message
1293 : * saying so, to provide a breadcrumb trail for users who may not remember
1294 : * that their logging is configured to go somewhere else.
1295 : */
1296 572 : if (!(Log_destination & LOG_DESTINATION_STDERR))
1297 0 : ereport(LOG,
1298 : (errmsg("ending log output to stderr"),
1299 : errhint("Future log output will go to log destination \"%s\".",
1300 : Log_destination_string)));
1301 :
1302 572 : whereToSendOutput = DestNone;
1303 :
1304 : /*
1305 : * Initialize stats collection subsystem (this does NOT start the
1306 : * collector process!)
1307 : */
1308 572 : pgstat_init();
1309 :
1310 : /*
1311 : * Initialize the autovacuum subsystem (again, no process start yet)
1312 : */
1313 572 : autovac_init();
1314 :
1315 : /*
1316 : * Load configuration files for client authentication.
1317 : */
1318 572 : if (!load_hba())
1319 : {
1320 : /*
1321 : * It makes no sense to continue if we fail to load the HBA file,
1322 : * since there is no way to connect to the database in this case.
1323 : */
1324 0 : ereport(FATAL,
1325 : (errmsg("could not load pg_hba.conf")));
1326 : }
1327 572 : if (!load_ident())
1328 : {
1329 : /*
1330 : * We can start up without the IDENT file, although it means that you
1331 : * cannot log in using any of the authentication methods that need a
1332 : * user name mapping. load_ident() already logged the details of error
1333 : * to the log.
1334 : */
1335 : }
1336 :
1337 : #ifdef HAVE_PTHREAD_IS_THREADED_NP
1338 :
1339 : /*
1340 : * On macOS, libintl replaces setlocale() with a version that calls
1341 : * CFLocaleCopyCurrent() when its second argument is "" and every relevant
1342 : * environment variable is unset or empty. CFLocaleCopyCurrent() makes
1343 : * the process multithreaded. The postmaster calls sigprocmask() and
1344 : * calls fork() without an immediate exec(), both of which have undefined
1345 : * behavior in a multithreaded program. A multithreaded postmaster is the
1346 : * normal case on Windows, which offers neither fork() nor sigprocmask().
1347 : */
1348 : if (pthread_is_threaded_np() != 0)
1349 : ereport(FATAL,
1350 : (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
1351 : errmsg("postmaster became multithreaded during startup"),
1352 : errhint("Set the LC_ALL environment variable to a valid locale.")));
1353 : #endif
1354 :
1355 : /*
1356 : * Remember postmaster startup time
1357 : */
1358 572 : PgStartTime = GetCurrentTimestamp();
1359 :
1360 : /*
1361 : * Report postmaster status in the postmaster.pid file, to allow pg_ctl to
1362 : * see what's happening.
1363 : */
1364 572 : AddToDataDirLockFile(LOCK_FILE_LINE_PM_STATUS, PM_STATUS_STARTING);
1365 :
1366 : /*
1367 : * We're ready to rock and roll...
1368 : */
1369 572 : StartupPID = StartupDataBase();
1370 : Assert(StartupPID != 0);
1371 572 : StartupStatus = STARTUP_RUNNING;
1372 572 : pmState = PM_STARTUP;
1373 :
1374 : /* Some workers may be scheduled to start now */
1375 572 : maybe_start_bgworkers();
1376 :
1377 572 : status = ServerLoop();
1378 :
1379 : /*
1380 : * ServerLoop probably shouldn't ever return, but if it does, close down.
1381 : */
1382 0 : ExitPostmaster(status != STATUS_OK);
1383 :
1384 : abort(); /* not reached */
1385 : }
1386 :
1387 :
1388 : /*
1389 : * on_proc_exit callback to close server's listen sockets
1390 : */
1391 : static void
1392 570 : CloseServerPorts(int status, Datum arg)
1393 : {
1394 : int i;
1395 :
1396 : /*
1397 : * First, explicitly close all the socket FDs. We used to just let this
1398 : * happen implicitly at postmaster exit, but it's better to close them
1399 : * before we remove the postmaster.pid lockfile; otherwise there's a race
1400 : * condition if a new postmaster wants to re-use the TCP port number.
1401 : */
1402 37050 : for (i = 0; i < MAXLISTEN; i++)
1403 : {
1404 36480 : if (ListenSocket[i] != PGINVALID_SOCKET)
1405 : {
1406 594 : StreamClose(ListenSocket[i]);
1407 594 : ListenSocket[i] = PGINVALID_SOCKET;
1408 : }
1409 : }
1410 :
1411 : /*
1412 : * Next, remove any filesystem entries for Unix sockets. To avoid race
1413 : * conditions against incoming postmasters, this must happen after closing
1414 : * the sockets and before removing lock files.
1415 : */
1416 570 : RemoveSocketFiles();
1417 :
1418 : /*
1419 : * We don't do anything about socket lock files here; those will be
1420 : * removed in a later on_proc_exit callback.
1421 : */
1422 570 : }
1423 :
1424 : /*
1425 : * on_proc_exit callback to delete external_pid_file
1426 : */
1427 : static void
1428 0 : unlink_external_pid_file(int status, Datum arg)
1429 : {
1430 0 : if (external_pid_file)
1431 0 : unlink(external_pid_file);
1432 0 : }
1433 :
1434 :
1435 : /*
1436 : * Compute and check the directory paths to files that are part of the
1437 : * installation (as deduced from the postgres executable's own location)
1438 : */
1439 : static void
1440 580 : getInstallationPaths(const char *argv0)
1441 : {
1442 : DIR *pdir;
1443 :
1444 : /* Locate the postgres executable itself */
1445 580 : if (find_my_exec(argv0, my_exec_path) < 0)
1446 0 : elog(FATAL, "%s: could not locate my own executable path", argv0);
1447 :
1448 : #ifdef EXEC_BACKEND
1449 : /* Locate executable backend before we change working directory */
1450 : if (find_other_exec(argv0, "postgres", PG_BACKEND_VERSIONSTR,
1451 : postgres_exec_path) < 0)
1452 : ereport(FATAL,
1453 : (errmsg("%s: could not locate matching postgres executable",
1454 : argv0)));
1455 : #endif
1456 :
1457 : /*
1458 : * Locate the pkglib directory --- this has to be set early in case we try
1459 : * to load any modules from it in response to postgresql.conf entries.
1460 : */
1461 580 : get_pkglib_path(my_exec_path, pkglib_path);
1462 :
1463 : /*
1464 : * Verify that there's a readable directory there; otherwise the Postgres
1465 : * installation is incomplete or corrupt. (A typical cause of this
1466 : * failure is that the postgres executable has been moved or hardlinked to
1467 : * some directory that's not a sibling of the installation lib/
1468 : * directory.)
1469 : */
1470 580 : pdir = AllocateDir(pkglib_path);
1471 580 : if (pdir == NULL)
1472 0 : ereport(ERROR,
1473 : (errcode_for_file_access(),
1474 : errmsg("could not open directory \"%s\": %m",
1475 : pkglib_path),
1476 : errhint("This may indicate an incomplete PostgreSQL installation, or that the file \"%s\" has been moved away from its proper location.",
1477 : my_exec_path)));
1478 580 : FreeDir(pdir);
1479 :
1480 : /*
1481 : * XXX is it worth similarly checking the share/ directory? If the lib/
1482 : * directory is there, then share/ probably is too.
1483 : */
1484 580 : }
1485 :
1486 : /*
1487 : * Check that pg_control exists in the correct location in the data directory.
1488 : *
1489 : * No attempt is made to validate the contents of pg_control here. This is
1490 : * just a sanity check to see if we are looking at a real data directory.
1491 : */
1492 : static void
1493 578 : checkControlFile(void)
1494 : {
1495 : char path[MAXPGPATH];
1496 : FILE *fp;
1497 :
1498 578 : snprintf(path, sizeof(path), "%s/global/pg_control", DataDir);
1499 :
1500 578 : fp = AllocateFile(path, PG_BINARY_R);
1501 578 : if (fp == NULL)
1502 : {
1503 0 : write_stderr("%s: could not find the database system\n"
1504 : "Expected to find it in the directory \"%s\",\n"
1505 : "but could not open file \"%s\": %s\n",
1506 0 : progname, DataDir, path, strerror(errno));
1507 0 : ExitPostmaster(2);
1508 : }
1509 578 : FreeFile(fp);
1510 578 : }
1511 :
1512 : /*
1513 : * Determine how long should we let ServerLoop sleep.
1514 : *
1515 : * In normal conditions we wait at most one minute, to ensure that the other
1516 : * background tasks handled by ServerLoop get done even when no requests are
1517 : * arriving. However, if there are background workers waiting to be started,
1518 : * we don't actually sleep so that they are quickly serviced. Other exception
1519 : * cases are as shown in the code.
1520 : */
1521 : static void
1522 16628 : DetermineSleepTime(struct timeval *timeout)
1523 : {
1524 16628 : TimestampTz next_wakeup = 0;
1525 :
1526 : /*
1527 : * Normal case: either there are no background workers at all, or we're in
1528 : * a shutdown sequence (during which we ignore bgworkers altogether).
1529 : */
1530 30732 : if (Shutdown > NoShutdown ||
1531 28208 : (!StartWorkerNeeded && !HaveCrashedWorker))
1532 : {
1533 16628 : if (AbortStartTime != 0)
1534 : {
1535 : /* time left to abort; clamp to 0 in case it already expired */
1536 496 : timeout->tv_sec = SIGKILL_CHILDREN_AFTER_SECS -
1537 496 : (time(NULL) - AbortStartTime);
1538 496 : timeout->tv_sec = Max(timeout->tv_sec, 0);
1539 496 : timeout->tv_usec = 0;
1540 : }
1541 : else
1542 : {
1543 16132 : timeout->tv_sec = 60;
1544 16132 : timeout->tv_usec = 0;
1545 : }
1546 16628 : return;
1547 : }
1548 :
1549 0 : if (StartWorkerNeeded)
1550 : {
1551 0 : timeout->tv_sec = 0;
1552 0 : timeout->tv_usec = 0;
1553 0 : return;
1554 : }
1555 :
1556 0 : if (HaveCrashedWorker)
1557 : {
1558 : slist_mutable_iter siter;
1559 :
1560 : /*
1561 : * When there are crashed bgworkers, we sleep just long enough that
1562 : * they are restarted when they request to be. Scan the list to
1563 : * determine the minimum of all wakeup times according to most recent
1564 : * crash time and requested restart interval.
1565 : */
1566 0 : slist_foreach_modify(siter, &BackgroundWorkerList)
1567 : {
1568 : RegisteredBgWorker *rw;
1569 : TimestampTz this_wakeup;
1570 :
1571 0 : rw = slist_container(RegisteredBgWorker, rw_lnode, siter.cur);
1572 :
1573 0 : if (rw->rw_crashed_at == 0)
1574 0 : continue;
1575 :
1576 0 : if (rw->rw_worker.bgw_restart_time == BGW_NEVER_RESTART
1577 0 : || rw->rw_terminate)
1578 : {
1579 0 : ForgetBackgroundWorker(&siter);
1580 0 : continue;
1581 : }
1582 :
1583 0 : this_wakeup = TimestampTzPlusMilliseconds(rw->rw_crashed_at,
1584 : 1000L * rw->rw_worker.bgw_restart_time);
1585 0 : if (next_wakeup == 0 || this_wakeup < next_wakeup)
1586 0 : next_wakeup = this_wakeup;
1587 : }
1588 : }
1589 :
1590 0 : if (next_wakeup != 0)
1591 : {
1592 : long secs;
1593 : int microsecs;
1594 :
1595 0 : TimestampDifference(GetCurrentTimestamp(), next_wakeup,
1596 : &secs, µsecs);
1597 0 : timeout->tv_sec = secs;
1598 0 : timeout->tv_usec = microsecs;
1599 :
1600 : /* Ensure we don't exceed one minute */
1601 0 : if (timeout->tv_sec > 60)
1602 : {
1603 0 : timeout->tv_sec = 60;
1604 0 : timeout->tv_usec = 0;
1605 : }
1606 : }
1607 : else
1608 : {
1609 0 : timeout->tv_sec = 60;
1610 0 : timeout->tv_usec = 0;
1611 : }
1612 : }
1613 :
1614 : /*
1615 : * Main idle loop of postmaster
1616 : *
1617 : * NB: Needs to be called with signals blocked
1618 : */
1619 : static int
1620 572 : ServerLoop(void)
1621 : {
1622 : fd_set readmask;
1623 : int nSockets;
1624 : time_t last_lockfile_recheck_time,
1625 : last_touch_time;
1626 :
1627 572 : last_lockfile_recheck_time = last_touch_time = time(NULL);
1628 :
1629 572 : nSockets = initMasks(&readmask);
1630 :
1631 : for (;;)
1632 16616 : {
1633 : fd_set rmask;
1634 : int selres;
1635 : time_t now;
1636 :
1637 : /*
1638 : * Wait for a connection request to arrive.
1639 : *
1640 : * We block all signals except while sleeping. That makes it safe for
1641 : * signal handlers, which again block all signals while executing, to
1642 : * do nontrivial work.
1643 : *
1644 : * If we are in PM_WAIT_DEAD_END state, then we don't want to accept
1645 : * any new connections, so we don't call select(), and just sleep.
1646 : */
1647 17188 : memcpy((char *) &rmask, (char *) &readmask, sizeof(fd_set));
1648 :
1649 17188 : if (pmState == PM_WAIT_DEAD_END)
1650 : {
1651 560 : PG_SETMASK(&UnBlockSig);
1652 :
1653 560 : pg_usleep(100000L); /* 100 msec seems reasonable */
1654 18 : selres = 0;
1655 :
1656 18 : PG_SETMASK(&BlockSig);
1657 : }
1658 : else
1659 : {
1660 : /* must set timeout each time; some OSes change it! */
1661 : struct timeval timeout;
1662 :
1663 : /* Needs to run with blocked signals! */
1664 16628 : DetermineSleepTime(&timeout);
1665 :
1666 16628 : PG_SETMASK(&UnBlockSig);
1667 :
1668 16628 : selres = select(nSockets, &rmask, NULL, NULL, &timeout);
1669 :
1670 16600 : PG_SETMASK(&BlockSig);
1671 : }
1672 :
1673 : /* Now check the select() result */
1674 16618 : if (selres < 0)
1675 : {
1676 9730 : if (errno != EINTR && errno != EWOULDBLOCK)
1677 : {
1678 0 : ereport(LOG,
1679 : (errcode_for_socket_access(),
1680 : errmsg("select() failed in postmaster: %m")));
1681 0 : return STATUS_ERROR;
1682 : }
1683 : }
1684 :
1685 : /*
1686 : * New connection pending on any of our sockets? If so, fork a child
1687 : * process to deal with it.
1688 : */
1689 16618 : if (selres > 0)
1690 : {
1691 : int i;
1692 :
1693 14128 : for (i = 0; i < MAXLISTEN; i++)
1694 : {
1695 14128 : if (ListenSocket[i] == PGINVALID_SOCKET)
1696 6868 : break;
1697 7260 : if (FD_ISSET(ListenSocket[i], &rmask))
1698 : {
1699 : Port *port;
1700 :
1701 6870 : port = ConnCreate(ListenSocket[i]);
1702 6870 : if (port)
1703 : {
1704 6870 : BackendStartup(port);
1705 :
1706 : /*
1707 : * We no longer need the open socket or port structure
1708 : * in this process
1709 : */
1710 6868 : StreamClose(port->sock);
1711 6868 : ConnFree(port);
1712 : }
1713 : }
1714 : }
1715 : }
1716 :
1717 : /* If we have lost the log collector, try to start a new one */
1718 16616 : if (SysLoggerPID == 0 && Logging_collector)
1719 0 : SysLoggerPID = SysLogger_Start();
1720 :
1721 : /*
1722 : * If no background writer process is running, and we are not in a
1723 : * state that prevents it, start one. It doesn't matter if this
1724 : * fails, we'll just try again later. Likewise for the checkpointer.
1725 : */
1726 20634 : if (pmState == PM_RUN || pmState == PM_RECOVERY ||
1727 4018 : pmState == PM_HOT_STANDBY)
1728 : {
1729 13416 : if (CheckpointerPID == 0)
1730 0 : CheckpointerPID = StartCheckpointer();
1731 13416 : if (BgWriterPID == 0)
1732 0 : BgWriterPID = StartBackgroundWriter();
1733 : }
1734 :
1735 : /*
1736 : * Likewise, if we have lost the walwriter process, try to start a new
1737 : * one. But this is needed only in normal operation (else we cannot
1738 : * be writing any new WAL).
1739 : */
1740 16616 : if (WalWriterPID == 0 && pmState == PM_RUN)
1741 0 : WalWriterPID = StartWalWriter();
1742 :
1743 : /*
1744 : * If we have lost the autovacuum launcher, try to start a new one. We
1745 : * don't want autovacuum to run in binary upgrade mode because
1746 : * autovacuum might update relfrozenxid for empty tables before the
1747 : * physical files are put in place.
1748 : */
1749 19430 : if (!IsBinaryUpgrade && AutoVacPID == 0 &&
1750 5628 : (AutoVacuumingActive() || start_autovac_launcher) &&
1751 2586 : pmState == PM_RUN)
1752 : {
1753 0 : AutoVacPID = StartAutoVacLauncher();
1754 0 : if (AutoVacPID != 0)
1755 0 : start_autovac_launcher = false; /* signal processed */
1756 : }
1757 :
1758 : /* If we have lost the stats collector, try to start a new one */
1759 16744 : if (PgStatPID == 0 &&
1760 256 : (pmState == PM_RUN || pmState == PM_HOT_STANDBY))
1761 0 : PgStatPID = pgstat_start();
1762 :
1763 : /* If we have lost the archiver, try to start a new one. */
1764 16616 : if (PgArchPID == 0 && PgArchStartupAllowed())
1765 0 : PgArchPID = pgarch_start();
1766 :
1767 : /* If we need to signal the autovacuum launcher, do so now */
1768 16616 : if (avlauncher_needs_signal)
1769 : {
1770 0 : avlauncher_needs_signal = false;
1771 0 : if (AutoVacPID != 0)
1772 0 : kill(AutoVacPID, SIGUSR2);
1773 : }
1774 :
1775 : /* If we need to start a WAL receiver, try to do that now */
1776 16616 : if (WalReceiverRequested)
1777 152 : MaybeStartWalReceiver();
1778 :
1779 : /* Get other worker processes running, if needed */
1780 16616 : if (StartWorkerNeeded || HaveCrashedWorker)
1781 3070 : maybe_start_bgworkers();
1782 :
1783 : #ifdef HAVE_PTHREAD_IS_THREADED_NP
1784 :
1785 : /*
1786 : * With assertions enabled, check regularly for appearance of
1787 : * additional threads. All builds check at start and exit.
1788 : */
1789 : Assert(pthread_is_threaded_np() == 0);
1790 : #endif
1791 :
1792 : /*
1793 : * Lastly, check to see if it's time to do some things that we don't
1794 : * want to do every single time through the loop, because they're a
1795 : * bit expensive. Note that there's up to a minute of slop in when
1796 : * these tasks will be performed, since DetermineSleepTime() will let
1797 : * us sleep at most that long; except for SIGKILL timeout which has
1798 : * special-case logic there.
1799 : */
1800 16616 : now = time(NULL);
1801 :
1802 : /*
1803 : * If we already sent SIGQUIT to children and they are slow to shut
1804 : * down, it's time to send them SIGKILL. This doesn't happen
1805 : * normally, but under certain conditions backends can get stuck while
1806 : * shutting down. This is a last measure to get them unwedged.
1807 : *
1808 : * Note we also do this during recovery from a process crash.
1809 : */
1810 17324 : if ((Shutdown >= ImmediateShutdown || (FatalError && !SendStop)) &&
1811 1408 : AbortStartTime != 0 &&
1812 700 : (now - AbortStartTime) >= SIGKILL_CHILDREN_AFTER_SECS)
1813 : {
1814 : /* We were gentle with them before. Not anymore */
1815 0 : TerminateChildren(SIGKILL);
1816 : /* reset flag so we don't SIGKILL again */
1817 0 : AbortStartTime = 0;
1818 : }
1819 :
1820 : /*
1821 : * Once a minute, verify that postmaster.pid hasn't been removed or
1822 : * overwritten. If it has, we force a shutdown. This avoids having
1823 : * postmasters and child processes hanging around after their database
1824 : * is gone, and maybe causing problems if a new database cluster is
1825 : * created in the same place. It also provides some protection
1826 : * against a DBA foolishly removing postmaster.pid and manually
1827 : * starting a new postmaster. Data corruption is likely to ensue from
1828 : * that anyway, but we can minimize the damage by aborting ASAP.
1829 : */
1830 16616 : if (now - last_lockfile_recheck_time >= 1 * SECS_PER_MINUTE)
1831 : {
1832 10 : if (!RecheckDataDirLockFile())
1833 : {
1834 0 : ereport(LOG,
1835 : (errmsg("performing immediate shutdown because data directory lock file is invalid")));
1836 0 : kill(MyProcPid, SIGQUIT);
1837 : }
1838 10 : last_lockfile_recheck_time = now;
1839 : }
1840 :
1841 : /*
1842 : * Touch Unix socket and lock files every 58 minutes, to ensure that
1843 : * they are not removed by overzealous /tmp-cleaning tasks. We assume
1844 : * no one runs cleaners with cutoff times of less than an hour ...
1845 : */
1846 16616 : if (now - last_touch_time >= 58 * SECS_PER_MINUTE)
1847 : {
1848 0 : TouchSocketFiles();
1849 0 : TouchSocketLockFiles();
1850 0 : last_touch_time = now;
1851 : }
1852 : }
1853 : }
1854 :
1855 : /*
1856 : * Initialise the masks for select() for the ports we are listening on.
1857 : * Return the number of sockets to listen on.
1858 : */
1859 : static int
1860 572 : initMasks(fd_set *rmask)
1861 : {
1862 572 : int maxsock = -1;
1863 : int i;
1864 :
1865 572 : FD_ZERO(rmask);
1866 :
1867 1168 : for (i = 0; i < MAXLISTEN; i++)
1868 : {
1869 1168 : int fd = ListenSocket[i];
1870 :
1871 1168 : if (fd == PGINVALID_SOCKET)
1872 572 : break;
1873 596 : FD_SET(fd, rmask);
1874 :
1875 596 : if (fd > maxsock)
1876 596 : maxsock = fd;
1877 : }
1878 :
1879 572 : return maxsock + 1;
1880 : }
1881 :
1882 :
1883 : /*
1884 : * Read a client's startup packet and do something according to it.
1885 : *
1886 : * Returns STATUS_OK or STATUS_ERROR, or might call ereport(FATAL) and
1887 : * not return at all.
1888 : *
1889 : * (Note that ereport(FATAL) stuff is sent to the client, so only use it
1890 : * if that's what you want. Return STATUS_ERROR if you don't want to
1891 : * send anything to the client, which would typically be appropriate
1892 : * if we detect a communications failure.)
1893 : *
1894 : * Set secure_done when negotiation of an encrypted layer (currently, TLS or
1895 : * GSSAPI) is already completed.
1896 : */
1897 : static int
1898 7114 : ProcessStartupPacket(Port *port, bool secure_done)
1899 : {
1900 : int32 len;
1901 : void *buf;
1902 : ProtocolVersion proto;
1903 : MemoryContext oldcontext;
1904 :
1905 7114 : pq_startmsgread();
1906 :
1907 : /*
1908 : * Grab the first byte of the length word separately, so that we can tell
1909 : * whether we have no data at all or an incomplete packet. (This might
1910 : * sound inefficient, but it's not really, because of buffering in
1911 : * pqcomm.c.)
1912 : */
1913 7114 : if (pq_getbytes((char *) &len, 1) == EOF)
1914 : {
1915 : /*
1916 : * If we get no data at all, don't clutter the log with a complaint;
1917 : * such cases often occur for legitimate reasons. An example is that
1918 : * we might be here after responding to NEGOTIATE_SSL_CODE, and if the
1919 : * client didn't like our response, it'll probably just drop the
1920 : * connection. Service-monitoring software also often just opens and
1921 : * closes a connection without sending anything. (So do port
1922 : * scanners, which may be less benign, but it's not really our job to
1923 : * notice those.)
1924 : */
1925 12 : return STATUS_ERROR;
1926 : }
1927 :
1928 7102 : if (pq_getbytes(((char *) &len) + 1, 3) == EOF)
1929 : {
1930 : /* Got a partial length word, so bleat about that */
1931 0 : if (!secure_done)
1932 0 : ereport(COMMERROR,
1933 : (errcode(ERRCODE_PROTOCOL_VIOLATION),
1934 : errmsg("incomplete startup packet")));
1935 0 : return STATUS_ERROR;
1936 : }
1937 :
1938 7102 : len = pg_ntoh32(len);
1939 7102 : len -= 4;
1940 :
1941 14204 : if (len < (int32) sizeof(ProtocolVersion) ||
1942 7102 : len > MAX_STARTUP_PACKET_LENGTH)
1943 : {
1944 0 : ereport(COMMERROR,
1945 : (errcode(ERRCODE_PROTOCOL_VIOLATION),
1946 : errmsg("invalid length of startup packet")));
1947 0 : return STATUS_ERROR;
1948 : }
1949 :
1950 : /*
1951 : * Allocate at least the size of an old-style startup packet, plus one
1952 : * extra byte, and make sure all are zeroes. This ensures we will have
1953 : * null termination of all strings, in both fixed- and variable-length
1954 : * packet layouts.
1955 : */
1956 7102 : if (len <= (int32) sizeof(StartupPacket))
1957 7102 : buf = palloc0(sizeof(StartupPacket) + 1);
1958 : else
1959 0 : buf = palloc0(len + 1);
1960 :
1961 7102 : if (pq_getbytes(buf, len) == EOF)
1962 : {
1963 0 : ereport(COMMERROR,
1964 : (errcode(ERRCODE_PROTOCOL_VIOLATION),
1965 : errmsg("incomplete startup packet")));
1966 0 : return STATUS_ERROR;
1967 : }
1968 7102 : pq_endmsgread();
1969 :
1970 : /*
1971 : * The first field is either a protocol version number or a special
1972 : * request code.
1973 : */
1974 7102 : port->proto = proto = pg_ntoh32(*((ProtocolVersion *) buf));
1975 :
1976 7102 : if (proto == CANCEL_REQUEST_CODE)
1977 : {
1978 2 : processCancelRequest(port, buf);
1979 : /* Not really an error, but we don't want to proceed further */
1980 2 : return STATUS_ERROR;
1981 : }
1982 :
1983 7100 : if (proto == NEGOTIATE_SSL_CODE && !secure_done)
1984 : {
1985 : char SSLok;
1986 :
1987 : #ifdef USE_SSL
1988 : /* No SSL when disabled or on Unix sockets */
1989 378 : if (!LoadedSSL || IS_AF_UNIX(port->laddr.addr.ss_family))
1990 294 : SSLok = 'N';
1991 : else
1992 84 : SSLok = 'S'; /* Support for SSL */
1993 : #else
1994 : SSLok = 'N'; /* No support for SSL */
1995 : #endif
1996 :
1997 : retry1:
1998 378 : if (send(port->sock, &SSLok, 1, 0) != 1)
1999 : {
2000 0 : if (errno == EINTR)
2001 0 : goto retry1; /* if interrupted, just retry */
2002 0 : ereport(COMMERROR,
2003 : (errcode_for_socket_access(),
2004 : errmsg("failed to send SSL negotiation response: %m")));
2005 0 : return STATUS_ERROR; /* close the connection */
2006 : }
2007 :
2008 : #ifdef USE_SSL
2009 378 : if (SSLok == 'S' && secure_open_server(port) == -1)
2010 20 : return STATUS_ERROR;
2011 : #endif
2012 : /* regular startup packet, cancel, etc packet should follow... */
2013 : /* but not another SSL negotiation request */
2014 358 : return ProcessStartupPacket(port, true);
2015 : }
2016 6722 : else if (proto == NEGOTIATE_GSS_CODE && !secure_done)
2017 : {
2018 0 : char GSSok = 'N';
2019 : #ifdef ENABLE_GSS
2020 : /* No GSSAPI encryption when on Unix socket */
2021 : if (!IS_AF_UNIX(port->laddr.addr.ss_family))
2022 : GSSok = 'G';
2023 : #endif
2024 :
2025 0 : while (send(port->sock, &GSSok, 1, 0) != 1)
2026 : {
2027 0 : if (errno == EINTR)
2028 0 : continue;
2029 0 : ereport(COMMERROR,
2030 : (errcode_for_socket_access(),
2031 : errmsg("failed to send GSSAPI negotiation response: %m")));
2032 0 : return STATUS_ERROR; /* close the connection */
2033 : }
2034 :
2035 : #ifdef ENABLE_GSS
2036 : if (GSSok == 'G' && secure_open_gssapi(port) == -1)
2037 : return STATUS_ERROR;
2038 : #endif
2039 : /* Won't ever see more than one negotiation request */
2040 0 : return ProcessStartupPacket(port, true);
2041 : }
2042 :
2043 : /* Could add additional special packet types here */
2044 :
2045 : /*
2046 : * Set FrontendProtocol now so that ereport() knows what format to send if
2047 : * we fail during startup.
2048 : */
2049 6722 : FrontendProtocol = proto;
2050 :
2051 : /* Check that the major protocol version is in range. */
2052 13444 : if (PG_PROTOCOL_MAJOR(proto) < PG_PROTOCOL_MAJOR(PG_PROTOCOL_EARLIEST) ||
2053 6722 : PG_PROTOCOL_MAJOR(proto) > PG_PROTOCOL_MAJOR(PG_PROTOCOL_LATEST))
2054 0 : ereport(FATAL,
2055 : (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
2056 : errmsg("unsupported frontend protocol %u.%u: server supports %u.0 to %u.%u",
2057 : PG_PROTOCOL_MAJOR(proto), PG_PROTOCOL_MINOR(proto),
2058 : PG_PROTOCOL_MAJOR(PG_PROTOCOL_EARLIEST),
2059 : PG_PROTOCOL_MAJOR(PG_PROTOCOL_LATEST),
2060 : PG_PROTOCOL_MINOR(PG_PROTOCOL_LATEST))));
2061 :
2062 : /*
2063 : * Now fetch parameters out of startup packet and save them into the Port
2064 : * structure. All data structures attached to the Port struct must be
2065 : * allocated in TopMemoryContext so that they will remain available in a
2066 : * running backend (even after PostmasterContext is destroyed). We need
2067 : * not worry about leaking this storage on failure, since we aren't in the
2068 : * postmaster process anymore.
2069 : */
2070 6722 : oldcontext = MemoryContextSwitchTo(TopMemoryContext);
2071 :
2072 6722 : if (PG_PROTOCOL_MAJOR(proto) >= 3)
2073 : {
2074 6722 : int32 offset = sizeof(ProtocolVersion);
2075 6722 : List *unrecognized_protocol_options = NIL;
2076 :
2077 : /*
2078 : * Scan packet body for name/option pairs. We can assume any string
2079 : * beginning within the packet body is null-terminated, thanks to
2080 : * zeroing extra byte above.
2081 : */
2082 6722 : port->guc_options = NIL;
2083 :
2084 44532 : while (offset < len)
2085 : {
2086 37810 : char *nameptr = ((char *) buf) + offset;
2087 : int32 valoffset;
2088 : char *valptr;
2089 :
2090 37810 : if (*nameptr == '\0')
2091 6722 : break; /* found packet terminator */
2092 31088 : valoffset = offset + strlen(nameptr) + 1;
2093 31088 : if (valoffset >= len)
2094 0 : break; /* missing value, will complain below */
2095 31088 : valptr = ((char *) buf) + valoffset;
2096 :
2097 31088 : if (strcmp(nameptr, "database") == 0)
2098 6722 : port->database_name = pstrdup(valptr);
2099 24366 : else if (strcmp(nameptr, "user") == 0)
2100 6722 : port->user_name = pstrdup(valptr);
2101 17644 : else if (strcmp(nameptr, "options") == 0)
2102 3318 : port->cmdline_options = pstrdup(valptr);
2103 14326 : else if (strcmp(nameptr, "replication") == 0)
2104 : {
2105 : /*
2106 : * Due to backward compatibility concerns the replication
2107 : * parameter is a hybrid beast which allows the value to be
2108 : * either boolean or the string 'database'. The latter
2109 : * connects to a specific database which is e.g. required for
2110 : * logical decoding while.
2111 : */
2112 474 : if (strcmp(valptr, "database") == 0)
2113 : {
2114 180 : am_walsender = true;
2115 180 : am_db_walsender = true;
2116 : }
2117 294 : else if (!parse_bool(valptr, &am_walsender))
2118 0 : ereport(FATAL,
2119 : (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
2120 : errmsg("invalid value for parameter \"%s\": \"%s\"",
2121 : "replication",
2122 : valptr),
2123 : errhint("Valid values are: \"false\", 0, \"true\", 1, \"database\".")));
2124 : }
2125 13852 : else if (strncmp(nameptr, "_pq_.", 5) == 0)
2126 : {
2127 : /*
2128 : * Any option beginning with _pq_. is reserved for use as a
2129 : * protocol-level option, but at present no such options are
2130 : * defined.
2131 : */
2132 0 : unrecognized_protocol_options =
2133 0 : lappend(unrecognized_protocol_options, pstrdup(nameptr));
2134 : }
2135 : else
2136 : {
2137 : /* Assume it's a generic GUC option */
2138 13852 : port->guc_options = lappend(port->guc_options,
2139 13852 : pstrdup(nameptr));
2140 13852 : port->guc_options = lappend(port->guc_options,
2141 13852 : pstrdup(valptr));
2142 :
2143 : /*
2144 : * Copy application_name to port if we come across it. This
2145 : * is done so we can log the application_name in the
2146 : * connection authorization message. Note that the GUC would
2147 : * be used but we haven't gone through GUC setup yet.
2148 : */
2149 13852 : if (strcmp(nameptr, "application_name") == 0)
2150 : {
2151 6634 : char *tmp_app_name = pstrdup(valptr);
2152 :
2153 6634 : pg_clean_ascii(tmp_app_name);
2154 :
2155 6634 : port->application_name = tmp_app_name;
2156 : }
2157 : }
2158 31088 : offset = valoffset + strlen(valptr) + 1;
2159 : }
2160 :
2161 : /*
2162 : * If we didn't find a packet terminator exactly at the end of the
2163 : * given packet length, complain.
2164 : */
2165 6722 : if (offset != len - 1)
2166 0 : ereport(FATAL,
2167 : (errcode(ERRCODE_PROTOCOL_VIOLATION),
2168 : errmsg("invalid startup packet layout: expected terminator as last byte")));
2169 :
2170 : /*
2171 : * If the client requested a newer protocol version or if the client
2172 : * requested any protocol options we didn't recognize, let them know
2173 : * the newest minor protocol version we do support and the names of
2174 : * any unrecognized options.
2175 : */
2176 6722 : if (PG_PROTOCOL_MINOR(proto) > PG_PROTOCOL_MINOR(PG_PROTOCOL_LATEST) ||
2177 : unrecognized_protocol_options != NIL)
2178 0 : SendNegotiateProtocolVersion(unrecognized_protocol_options);
2179 : }
2180 : else
2181 : {
2182 : /*
2183 : * Get the parameters from the old-style, fixed-width-fields startup
2184 : * packet as C strings. The packet destination was cleared first so a
2185 : * short packet has zeros silently added. We have to be prepared to
2186 : * truncate the pstrdup result for oversize fields, though.
2187 : */
2188 0 : StartupPacket *packet = (StartupPacket *) buf;
2189 :
2190 0 : port->database_name = pstrdup(packet->database);
2191 0 : if (strlen(port->database_name) > sizeof(packet->database))
2192 0 : port->database_name[sizeof(packet->database)] = '\0';
2193 0 : port->user_name = pstrdup(packet->user);
2194 0 : if (strlen(port->user_name) > sizeof(packet->user))
2195 0 : port->user_name[sizeof(packet->user)] = '\0';
2196 0 : port->cmdline_options = pstrdup(packet->options);
2197 0 : if (strlen(port->cmdline_options) > sizeof(packet->options))
2198 0 : port->cmdline_options[sizeof(packet->options)] = '\0';
2199 0 : port->guc_options = NIL;
2200 : }
2201 :
2202 : /* Check a user name was given. */
2203 6722 : if (port->user_name == NULL || port->user_name[0] == '\0')
2204 0 : ereport(FATAL,
2205 : (errcode(ERRCODE_INVALID_AUTHORIZATION_SPECIFICATION),
2206 : errmsg("no PostgreSQL user name specified in startup packet")));
2207 :
2208 : /* The database defaults to the user name. */
2209 6722 : if (port->database_name == NULL || port->database_name[0] == '\0')
2210 0 : port->database_name = pstrdup(port->user_name);
2211 :
2212 6722 : if (Db_user_namespace)
2213 : {
2214 : /*
2215 : * If user@, it is a global user, remove '@'. We only want to do this
2216 : * if there is an '@' at the end and no earlier in the user string or
2217 : * they may fake as a local user of another database attaching to this
2218 : * database.
2219 : */
2220 0 : if (strchr(port->user_name, '@') ==
2221 0 : port->user_name + strlen(port->user_name) - 1)
2222 0 : *strchr(port->user_name, '@') = '\0';
2223 : else
2224 : {
2225 : /* Append '@' and dbname */
2226 0 : port->user_name = psprintf("%s@%s", port->user_name, port->database_name);
2227 : }
2228 : }
2229 :
2230 : /*
2231 : * Truncate given database and user names to length of a Postgres name.
2232 : * This avoids lookup failures when overlength names are given.
2233 : */
2234 6722 : if (strlen(port->database_name) >= NAMEDATALEN)
2235 0 : port->database_name[NAMEDATALEN - 1] = '\0';
2236 6722 : if (strlen(port->user_name) >= NAMEDATALEN)
2237 0 : port->user_name[NAMEDATALEN - 1] = '\0';
2238 :
2239 : /*
2240 : * Normal walsender backends, e.g. for streaming replication, are not
2241 : * connected to a particular database. But walsenders used for logical
2242 : * replication need to connect to a specific database. We allow streaming
2243 : * replication commands to be issued even if connected to a database as it
2244 : * can make sense to first make a basebackup and then stream changes
2245 : * starting from that.
2246 : */
2247 6722 : if (am_walsender && !am_db_walsender)
2248 294 : port->database_name[0] = '\0';
2249 :
2250 : /*
2251 : * Done putting stuff in TopMemoryContext.
2252 : */
2253 6722 : MemoryContextSwitchTo(oldcontext);
2254 :
2255 : /*
2256 : * If we're going to reject the connection due to database state, say so
2257 : * now instead of wasting cycles on an authentication exchange. (This also
2258 : * allows a pg_ping utility to be written.)
2259 : */
2260 6722 : switch (port->canAcceptConnections)
2261 : {
2262 : case CAC_STARTUP:
2263 76 : ereport(FATAL,
2264 : (errcode(ERRCODE_CANNOT_CONNECT_NOW),
2265 : errmsg("the database system is starting up")));
2266 : break;
2267 : case CAC_SHUTDOWN:
2268 0 : ereport(FATAL,
2269 : (errcode(ERRCODE_CANNOT_CONNECT_NOW),
2270 : errmsg("the database system is shutting down")));
2271 : break;
2272 : case CAC_RECOVERY:
2273 4 : ereport(FATAL,
2274 : (errcode(ERRCODE_CANNOT_CONNECT_NOW),
2275 : errmsg("the database system is in recovery mode")));
2276 : break;
2277 : case CAC_TOOMANY:
2278 0 : ereport(FATAL,
2279 : (errcode(ERRCODE_TOO_MANY_CONNECTIONS),
2280 : errmsg("sorry, too many clients already")));
2281 : break;
2282 : case CAC_WAITBACKUP:
2283 : /* OK for now, will check in InitPostgres */
2284 0 : break;
2285 : case CAC_OK:
2286 6642 : break;
2287 : }
2288 :
2289 6642 : return STATUS_OK;
2290 : }
2291 :
2292 : /*
2293 : * Send a NegotiateProtocolVersion to the client. This lets the client know
2294 : * that they have requested a newer minor protocol version than we are able
2295 : * to speak. We'll speak the highest version we know about; the client can,
2296 : * of course, abandon the connection if that's a problem.
2297 : *
2298 : * We also include in the response a list of protocol options we didn't
2299 : * understand. This allows clients to include optional parameters that might
2300 : * be present either in newer protocol versions or third-party protocol
2301 : * extensions without fear of having to reconnect if those options are not
2302 : * understood, while at the same time making certain that the client is aware
2303 : * of which options were actually accepted.
2304 : */
2305 : static void
2306 0 : SendNegotiateProtocolVersion(List *unrecognized_protocol_options)
2307 : {
2308 : StringInfoData buf;
2309 : ListCell *lc;
2310 :
2311 0 : pq_beginmessage(&buf, 'v'); /* NegotiateProtocolVersion */
2312 0 : pq_sendint32(&buf, PG_PROTOCOL_LATEST);
2313 0 : pq_sendint32(&buf, list_length(unrecognized_protocol_options));
2314 0 : foreach(lc, unrecognized_protocol_options)
2315 0 : pq_sendstring(&buf, lfirst(lc));
2316 0 : pq_endmessage(&buf);
2317 :
2318 : /* no need to flush, some other message will follow */
2319 0 : }
2320 :
2321 : /*
2322 : * The client has sent a cancel request packet, not a normal
2323 : * start-a-new-connection packet. Perform the necessary processing.
2324 : * Nothing is sent back to the client.
2325 : */
2326 : static void
2327 2 : processCancelRequest(Port *port, void *pkt)
2328 : {
2329 2 : CancelRequestPacket *canc = (CancelRequestPacket *) pkt;
2330 : int backendPID;
2331 : int32 cancelAuthCode;
2332 : Backend *bp;
2333 :
2334 : #ifndef EXEC_BACKEND
2335 : dlist_iter iter;
2336 : #else
2337 : int i;
2338 : #endif
2339 :
2340 2 : backendPID = (int) pg_ntoh32(canc->backendPID);
2341 2 : cancelAuthCode = (int32) pg_ntoh32(canc->cancelAuthCode);
2342 :
2343 : /*
2344 : * See if we have a matching backend. In the EXEC_BACKEND case, we can no
2345 : * longer access the postmaster's own backend list, and must rely on the
2346 : * duplicate array in shared memory.
2347 : */
2348 : #ifndef EXEC_BACKEND
2349 2 : dlist_foreach(iter, &BackendList)
2350 : {
2351 2 : bp = dlist_container(Backend, elem, iter.cur);
2352 : #else
2353 : for (i = MaxLivePostmasterChildren() - 1; i >= 0; i--)
2354 : {
2355 : bp = (Backend *) &ShmemBackendArray[i];
2356 : #endif
2357 2 : if (bp->pid == backendPID)
2358 : {
2359 2 : if (bp->cancel_key == cancelAuthCode)
2360 : {
2361 : /* Found a match; signal that backend to cancel current op */
2362 2 : ereport(DEBUG2,
2363 : (errmsg_internal("processing cancel request: sending SIGINT to process %d",
2364 : backendPID)));
2365 2 : signal_child(bp->pid, SIGINT);
2366 : }
2367 : else
2368 : /* Right PID, wrong key: no way, Jose */
2369 0 : ereport(LOG,
2370 : (errmsg("wrong key in cancel request for process %d",
2371 : backendPID)));
2372 2 : return;
2373 : }
2374 : #ifndef EXEC_BACKEND /* make GNU Emacs 26.1 see brace balance */
2375 : }
2376 : #else
2377 : }
2378 : #endif
2379 :
2380 : /* No matching backend */
2381 0 : ereport(LOG,
2382 : (errmsg("PID %d in cancel request did not match any process",
2383 : backendPID)));
2384 : }
2385 :
2386 : /*
2387 : * canAcceptConnections --- check to see if database state allows connections.
2388 : */
2389 : static CAC_state
2390 6930 : canAcceptConnections(void)
2391 : {
2392 6930 : CAC_state result = CAC_OK;
2393 :
2394 : /*
2395 : * Can't start backends when in startup/shutdown/inconsistent recovery
2396 : * state.
2397 : *
2398 : * In state PM_WAIT_BACKUP only superusers can connect (this must be
2399 : * allowed so that a superuser can end online backup mode); we return
2400 : * CAC_WAITBACKUP code to indicate that this must be checked later. Note
2401 : * that neither CAC_OK nor CAC_WAITBACKUP can safely be returned until we
2402 : * have checked for too many children.
2403 : */
2404 6930 : if (pmState != PM_RUN)
2405 : {
2406 326 : if (pmState == PM_WAIT_BACKUP)
2407 0 : result = CAC_WAITBACKUP; /* allow superusers only */
2408 326 : else if (Shutdown > NoShutdown)
2409 0 : return CAC_SHUTDOWN; /* shutdown is pending */
2410 648 : else if (!FatalError &&
2411 568 : (pmState == PM_STARTUP ||
2412 246 : pmState == PM_RECOVERY))
2413 76 : return CAC_STARTUP; /* normal startup */
2414 496 : else if (!FatalError &&
2415 246 : pmState == PM_HOT_STANDBY)
2416 246 : result = CAC_OK; /* connection OK during hot standby */
2417 : else
2418 4 : return CAC_RECOVERY; /* else must be crash recovery */
2419 : }
2420 :
2421 : /*
2422 : * Don't start too many children.
2423 : *
2424 : * We allow more connections than we can have backends here because some
2425 : * might still be authenticating; they might fail auth, or some existing
2426 : * backend might exit before the auth cycle is completed. The exact
2427 : * MaxBackends limit is enforced when a new backend tries to join the
2428 : * shared-inval backend array.
2429 : *
2430 : * The limit here must match the sizes of the per-child-process arrays;
2431 : * see comments for MaxLivePostmasterChildren().
2432 : */
2433 6850 : if (CountChildren(BACKEND_TYPE_ALL) >= MaxLivePostmasterChildren())
2434 0 : result = CAC_TOOMANY;
2435 :
2436 6850 : return result;
2437 : }
2438 :
2439 :
2440 : /*
2441 : * ConnCreate -- create a local connection data structure
2442 : *
2443 : * Returns NULL on failure, other than out-of-memory which is fatal.
2444 : */
2445 : static Port *
2446 6870 : ConnCreate(int serverFd)
2447 : {
2448 : Port *port;
2449 :
2450 6870 : if (!(port = (Port *) calloc(1, sizeof(Port))))
2451 : {
2452 0 : ereport(LOG,
2453 : (errcode(ERRCODE_OUT_OF_MEMORY),
2454 : errmsg("out of memory")));
2455 0 : ExitPostmaster(1);
2456 : }
2457 :
2458 6870 : if (StreamConnection(serverFd, port) != STATUS_OK)
2459 : {
2460 0 : if (port->sock != PGINVALID_SOCKET)
2461 0 : StreamClose(port->sock);
2462 0 : ConnFree(port);
2463 0 : return NULL;
2464 : }
2465 :
2466 : /*
2467 : * Allocate GSSAPI specific state struct
2468 : */
2469 : #ifndef EXEC_BACKEND
2470 : #if defined(ENABLE_GSS) || defined(ENABLE_SSPI)
2471 : port->gss = (pg_gssinfo *) calloc(1, sizeof(pg_gssinfo));
2472 : if (!port->gss)
2473 : {
2474 : ereport(LOG,
2475 : (errcode(ERRCODE_OUT_OF_MEMORY),
2476 : errmsg("out of memory")));
2477 : ExitPostmaster(1);
2478 : }
2479 : #endif
2480 : #endif
2481 :
2482 6870 : return port;
2483 : }
2484 :
2485 :
2486 : /*
2487 : * ConnFree -- free a local connection data structure
2488 : */
2489 : static void
2490 6868 : ConnFree(Port *conn)
2491 : {
2492 : #ifdef USE_SSL
2493 6868 : secure_close(conn);
2494 : #endif
2495 6868 : if (conn->gss)
2496 0 : free(conn->gss);
2497 6868 : free(conn);
2498 6868 : }
2499 :
2500 :
2501 : /*
2502 : * ClosePostmasterPorts -- close all the postmaster's open sockets
2503 : *
2504 : * This is called during child process startup to release file descriptors
2505 : * that are not needed by that child process. The postmaster still has
2506 : * them open, of course.
2507 : *
2508 : * Note: we pass am_syslogger as a boolean because we don't want to set
2509 : * the global variable yet when this is called.
2510 : */
2511 : void
2512 11714 : ClosePostmasterPorts(bool am_syslogger)
2513 : {
2514 : int i;
2515 :
2516 : #ifndef WIN32
2517 :
2518 : /*
2519 : * Close the write end of postmaster death watch pipe. It's important to
2520 : * do this as early as possible, so that if postmaster dies, others won't
2521 : * think that it's still running because we're holding the pipe open.
2522 : */
2523 11714 : if (close(postmaster_alive_fds[POSTMASTER_FD_OWN]))
2524 0 : ereport(FATAL,
2525 : (errcode_for_file_access(),
2526 : errmsg_internal("could not close postmaster death monitoring pipe in child process: %m")));
2527 11714 : postmaster_alive_fds[POSTMASTER_FD_OWN] = -1;
2528 : #endif
2529 :
2530 : /* Close the listen sockets */
2531 761410 : for (i = 0; i < MAXLISTEN; i++)
2532 : {
2533 749696 : if (ListenSocket[i] != PGINVALID_SOCKET)
2534 : {
2535 12246 : StreamClose(ListenSocket[i]);
2536 12246 : ListenSocket[i] = PGINVALID_SOCKET;
2537 : }
2538 : }
2539 :
2540 : /* If using syslogger, close the read side of the pipe */
2541 11714 : if (!am_syslogger)
2542 : {
2543 : #ifndef WIN32
2544 11712 : if (syslogPipe[0] >= 0)
2545 18 : close(syslogPipe[0]);
2546 11712 : syslogPipe[0] = -1;
2547 : #else
2548 : if (syslogPipe[0])
2549 : CloseHandle(syslogPipe[0]);
2550 : syslogPipe[0] = 0;
2551 : #endif
2552 : }
2553 :
2554 : #ifdef USE_BONJOUR
2555 : /* If using Bonjour, close the connection to the mDNS daemon */
2556 : if (bonjour_sdref)
2557 : close(DNSServiceRefSockFD(bonjour_sdref));
2558 : #endif
2559 11714 : }
2560 :
2561 :
2562 : /*
2563 : * InitProcessGlobals -- set MyProcPid, MyStartTime[stamp], random seeds
2564 : *
2565 : * Called early in the postmaster and every backend.
2566 : */
2567 : void
2568 13568 : InitProcessGlobals(void)
2569 : {
2570 : unsigned int rseed;
2571 :
2572 13568 : MyProcPid = getpid();
2573 13568 : MyStartTimestamp = GetCurrentTimestamp();
2574 13568 : MyStartTime = timestamptz_to_time_t(MyStartTimestamp);
2575 :
2576 : /*
2577 : * Set a different seed for random() in every process. We want something
2578 : * unpredictable, so if possible, use high-quality random bits for the
2579 : * seed. Otherwise, fall back to a seed based on timestamp and PID.
2580 : */
2581 13568 : if (!pg_strong_random(&rseed, sizeof(rseed)))
2582 : {
2583 : /*
2584 : * Since PIDs and timestamps tend to change more frequently in their
2585 : * least significant bits, shift the timestamp left to allow a larger
2586 : * total number of seeds in a given time period. Since that would
2587 : * leave only 20 bits of the timestamp that cycle every ~1 second,
2588 : * also mix in some higher bits.
2589 : */
2590 0 : rseed = ((uint64) MyProcPid) ^
2591 0 : ((uint64) MyStartTimestamp << 12) ^
2592 0 : ((uint64) MyStartTimestamp >> 20);
2593 : }
2594 13568 : srandom(rseed);
2595 13568 : }
2596 :
2597 :
2598 : /*
2599 : * reset_shared -- reset shared memory and semaphores
2600 : */
2601 : static void
2602 578 : reset_shared(int port)
2603 : {
2604 : /*
2605 : * Create or re-create shared memory and semaphores.
2606 : *
2607 : * Note: in each "cycle of life" we will normally assign the same IPC keys
2608 : * (if using SysV shmem and/or semas), since the port number is used to
2609 : * determine IPC keys. This helps ensure that we will clean up dead IPC
2610 : * objects if the postmaster crashes and is restarted.
2611 : */
2612 578 : CreateSharedMemoryAndSemaphores(port);
2613 576 : }
2614 :
2615 :
2616 : /*
2617 : * SIGHUP -- reread config files, and tell children to do same
2618 : */
2619 : static void
2620 48 : SIGHUP_handler(SIGNAL_ARGS)
2621 : {
2622 48 : int save_errno = errno;
2623 :
2624 48 : PG_SETMASK(&BlockSig);
2625 :
2626 48 : if (Shutdown <= SmartShutdown)
2627 : {
2628 48 : ereport(LOG,
2629 : (errmsg("received SIGHUP, reloading configuration files")));
2630 48 : ProcessConfigFile(PGC_SIGHUP);
2631 48 : SignalChildren(SIGHUP);
2632 48 : if (StartupPID != 0)
2633 10 : signal_child(StartupPID, SIGHUP);
2634 48 : if (BgWriterPID != 0)
2635 48 : signal_child(BgWriterPID, SIGHUP);
2636 48 : if (CheckpointerPID != 0)
2637 48 : signal_child(CheckpointerPID, SIGHUP);
2638 48 : if (WalWriterPID != 0)
2639 38 : signal_child(WalWriterPID, SIGHUP);
2640 48 : if (WalReceiverPID != 0)
2641 10 : signal_child(WalReceiverPID, SIGHUP);
2642 48 : if (AutoVacPID != 0)
2643 38 : signal_child(AutoVacPID, SIGHUP);
2644 48 : if (PgArchPID != 0)
2645 0 : signal_child(PgArchPID, SIGHUP);
2646 48 : if (SysLoggerPID != 0)
2647 0 : signal_child(SysLoggerPID, SIGHUP);
2648 48 : if (PgStatPID != 0)
2649 48 : signal_child(PgStatPID, SIGHUP);
2650 :
2651 : /* Reload authentication config files too */
2652 48 : if (!load_hba())
2653 0 : ereport(LOG,
2654 : /* translator: %s is a configuration file */
2655 : (errmsg("%s was not reloaded", "pg_hba.conf")));
2656 :
2657 48 : if (!load_ident())
2658 0 : ereport(LOG,
2659 : (errmsg("%s was not reloaded", "pg_ident.conf")));
2660 :
2661 : #ifdef USE_SSL
2662 : /* Reload SSL configuration as well */
2663 48 : if (EnableSSL)
2664 : {
2665 0 : if (secure_initialize(false) == 0)
2666 0 : LoadedSSL = true;
2667 : else
2668 0 : ereport(LOG,
2669 : (errmsg("SSL configuration was not reloaded")));
2670 : }
2671 : else
2672 : {
2673 48 : secure_destroy();
2674 48 : LoadedSSL = false;
2675 : }
2676 : #endif
2677 :
2678 : #ifdef EXEC_BACKEND
2679 : /* Update the starting-point file for future children */
2680 : write_nondefault_variables(PGC_SIGHUP);
2681 : #endif
2682 : }
2683 :
2684 48 : PG_SETMASK(&UnBlockSig);
2685 :
2686 48 : errno = save_errno;
2687 48 : }
2688 :
2689 :
2690 : /*
2691 : * pmdie -- signal handler for processing various postmaster signals.
2692 : */
2693 : static void
2694 568 : pmdie(SIGNAL_ARGS)
2695 : {
2696 568 : int save_errno = errno;
2697 :
2698 568 : PG_SETMASK(&BlockSig);
2699 :
2700 568 : ereport(DEBUG2,
2701 : (errmsg_internal("postmaster received signal %d",
2702 : postgres_signal_arg)));
2703 :
2704 568 : switch (postgres_signal_arg)
2705 : {
2706 : case SIGTERM:
2707 :
2708 : /*
2709 : * Smart Shutdown:
2710 : *
2711 : * Wait for children to end their work, then shut down.
2712 : */
2713 8 : if (Shutdown >= SmartShutdown)
2714 0 : break;
2715 8 : Shutdown = SmartShutdown;
2716 8 : ereport(LOG,
2717 : (errmsg("received smart shutdown request")));
2718 :
2719 : /* Report status */
2720 8 : AddToDataDirLockFile(LOCK_FILE_LINE_PM_STATUS, PM_STATUS_STOPPING);
2721 : #ifdef USE_SYSTEMD
2722 : sd_notify(0, "STOPPING=1");
2723 : #endif
2724 :
2725 8 : if (pmState == PM_RUN || pmState == PM_RECOVERY ||
2726 0 : pmState == PM_HOT_STANDBY || pmState == PM_STARTUP)
2727 : {
2728 : /* autovac workers are told to shut down immediately */
2729 : /* and bgworkers too; does this need tweaking? */
2730 8 : SignalSomeChildren(SIGTERM,
2731 : BACKEND_TYPE_AUTOVAC | BACKEND_TYPE_BGWORKER);
2732 : /* and the autovac launcher too */
2733 8 : if (AutoVacPID != 0)
2734 0 : signal_child(AutoVacPID, SIGTERM);
2735 : /* and the bgwriter too */
2736 8 : if (BgWriterPID != 0)
2737 8 : signal_child(BgWriterPID, SIGTERM);
2738 : /* and the walwriter too */
2739 8 : if (WalWriterPID != 0)
2740 8 : signal_child(WalWriterPID, SIGTERM);
2741 :
2742 : /*
2743 : * If we're in recovery, we can't kill the startup process
2744 : * right away, because at present doing so does not release
2745 : * its locks. We might want to change this in a future
2746 : * release. For the time being, the PM_WAIT_READONLY state
2747 : * indicates that we're waiting for the regular (read only)
2748 : * backends to die off; once they do, we'll kill the startup
2749 : * and walreceiver processes.
2750 : */
2751 16 : pmState = (pmState == PM_RUN) ?
2752 8 : PM_WAIT_BACKUP : PM_WAIT_READONLY;
2753 : }
2754 :
2755 : /*
2756 : * Now wait for online backup mode to end and backends to exit. If
2757 : * that is already the case, PostmasterStateMachine will take the
2758 : * next step.
2759 : */
2760 8 : PostmasterStateMachine();
2761 8 : break;
2762 :
2763 : case SIGINT:
2764 :
2765 : /*
2766 : * Fast Shutdown:
2767 : *
2768 : * Abort all children with SIGTERM (rollback active transactions
2769 : * and exit) and shut down when they are gone.
2770 : */
2771 368 : if (Shutdown >= FastShutdown)
2772 0 : break;
2773 368 : Shutdown = FastShutdown;
2774 368 : ereport(LOG,
2775 : (errmsg("received fast shutdown request")));
2776 :
2777 : /* Report status */
2778 368 : AddToDataDirLockFile(LOCK_FILE_LINE_PM_STATUS, PM_STATUS_STOPPING);
2779 : #ifdef USE_SYSTEMD
2780 : sd_notify(0, "STOPPING=1");
2781 : #endif
2782 :
2783 368 : if (StartupPID != 0)
2784 22 : signal_child(StartupPID, SIGTERM);
2785 368 : if (BgWriterPID != 0)
2786 368 : signal_child(BgWriterPID, SIGTERM);
2787 368 : if (WalReceiverPID != 0)
2788 18 : signal_child(WalReceiverPID, SIGTERM);
2789 368 : if (pmState == PM_STARTUP || pmState == PM_RECOVERY)
2790 : {
2791 0 : SignalSomeChildren(SIGTERM, BACKEND_TYPE_BGWORKER);
2792 :
2793 : /*
2794 : * Only startup, bgwriter, walreceiver, possibly bgworkers,
2795 : * and/or checkpointer should be active in this state; we just
2796 : * signaled the first four, and we don't want to kill
2797 : * checkpointer yet.
2798 : */
2799 0 : pmState = PM_WAIT_BACKENDS;
2800 : }
2801 390 : else if (pmState == PM_RUN ||
2802 44 : pmState == PM_WAIT_BACKUP ||
2803 44 : pmState == PM_WAIT_READONLY ||
2804 44 : pmState == PM_WAIT_BACKENDS ||
2805 22 : pmState == PM_HOT_STANDBY)
2806 : {
2807 368 : ereport(LOG,
2808 : (errmsg("aborting any active transactions")));
2809 : /* shut down all backends and workers */
2810 368 : SignalSomeChildren(SIGTERM,
2811 : BACKEND_TYPE_NORMAL | BACKEND_TYPE_AUTOVAC |
2812 : BACKEND_TYPE_BGWORKER);
2813 : /* and the autovac launcher too */
2814 368 : if (AutoVacPID != 0)
2815 342 : signal_child(AutoVacPID, SIGTERM);
2816 : /* and the walwriter too */
2817 368 : if (WalWriterPID != 0)
2818 346 : signal_child(WalWriterPID, SIGTERM);
2819 368 : pmState = PM_WAIT_BACKENDS;
2820 : }
2821 :
2822 : /*
2823 : * Now wait for backends to exit. If there are none,
2824 : * PostmasterStateMachine will take the next step.
2825 : */
2826 368 : PostmasterStateMachine();
2827 368 : break;
2828 :
2829 : case SIGQUIT:
2830 :
2831 : /*
2832 : * Immediate Shutdown:
2833 : *
2834 : * abort all children with SIGQUIT, wait for them to exit,
2835 : * terminate remaining ones with SIGKILL, then exit without
2836 : * attempt to properly shut down the data base system.
2837 : */
2838 192 : if (Shutdown >= ImmediateShutdown)
2839 0 : break;
2840 192 : Shutdown = ImmediateShutdown;
2841 192 : ereport(LOG,
2842 : (errmsg("received immediate shutdown request")));
2843 :
2844 : /* Report status */
2845 192 : AddToDataDirLockFile(LOCK_FILE_LINE_PM_STATUS, PM_STATUS_STOPPING);
2846 : #ifdef USE_SYSTEMD
2847 : sd_notify(0, "STOPPING=1");
2848 : #endif
2849 :
2850 192 : TerminateChildren(SIGQUIT);
2851 192 : pmState = PM_WAIT_BACKENDS;
2852 :
2853 : /* set stopwatch for them to die */
2854 192 : AbortStartTime = time(NULL);
2855 :
2856 : /*
2857 : * Now wait for backends to exit. If there are none,
2858 : * PostmasterStateMachine will take the next step.
2859 : */
2860 192 : PostmasterStateMachine();
2861 192 : break;
2862 : }
2863 :
2864 568 : PG_SETMASK(&UnBlockSig);
2865 :
2866 568 : errno = save_errno;
2867 568 : }
2868 :
2869 : /*
2870 : * Reaper -- signal handler to cleanup after a child process dies.
2871 : */
2872 : static void
2873 11464 : reaper(SIGNAL_ARGS)
2874 : {
2875 11464 : int save_errno = errno;
2876 : int pid; /* process id of dead child process */
2877 : int exitstatus; /* its exit status */
2878 :
2879 11464 : PG_SETMASK(&BlockSig);
2880 :
2881 11464 : ereport(DEBUG4,
2882 : (errmsg_internal("reaping dead processes")));
2883 :
2884 35602 : while ((pid = waitpid(-1, &exitstatus, WNOHANG)) > 0)
2885 : {
2886 : /*
2887 : * Check if this child was a startup process.
2888 : */
2889 12676 : if (pid == StartupPID)
2890 : {
2891 576 : StartupPID = 0;
2892 :
2893 : /*
2894 : * Startup process exited in response to a shutdown request (or it
2895 : * completed normally regardless of the shutdown request).
2896 : */
2897 654 : if (Shutdown > NoShutdown &&
2898 156 : (EXIT_STATUS_0(exitstatus) || EXIT_STATUS_1(exitstatus)))
2899 : {
2900 22 : StartupStatus = STARTUP_NOT_RUNNING;
2901 22 : pmState = PM_WAIT_BACKENDS;
2902 : /* PostmasterStateMachine logic does the rest */
2903 22 : continue;
2904 : }
2905 :
2906 554 : if (EXIT_STATUS_3(exitstatus))
2907 : {
2908 0 : ereport(LOG,
2909 : (errmsg("shutdown at recovery target")));
2910 0 : StartupStatus = STARTUP_NOT_RUNNING;
2911 0 : Shutdown = SmartShutdown;
2912 0 : TerminateChildren(SIGTERM);
2913 0 : pmState = PM_WAIT_BACKENDS;
2914 : /* PostmasterStateMachine logic does the rest */
2915 0 : continue;
2916 : }
2917 :
2918 : /*
2919 : * Unexpected exit of startup process (including FATAL exit)
2920 : * during PM_STARTUP is treated as catastrophic. There are no
2921 : * other processes running yet, so we can just exit.
2922 : */
2923 554 : if (pmState == PM_STARTUP && !EXIT_STATUS_0(exitstatus))
2924 : {
2925 0 : LogChildExit(LOG, _("startup process"),
2926 : pid, exitstatus);
2927 0 : ereport(LOG,
2928 : (errmsg("aborting startup due to startup process failure")));
2929 0 : ExitPostmaster(1);
2930 : }
2931 :
2932 : /*
2933 : * After PM_STARTUP, any unexpected exit (including FATAL exit) of
2934 : * the startup process is catastrophic, so kill other children,
2935 : * and set StartupStatus so we don't try to reinitialize after
2936 : * they're gone. Exception: if StartupStatus is STARTUP_SIGNALED,
2937 : * then we previously sent the startup process a SIGQUIT; so
2938 : * that's probably the reason it died, and we do want to try to
2939 : * restart in that case.
2940 : */
2941 554 : if (!EXIT_STATUS_0(exitstatus))
2942 : {
2943 56 : if (StartupStatus == STARTUP_SIGNALED)
2944 56 : StartupStatus = STARTUP_NOT_RUNNING;
2945 : else
2946 0 : StartupStatus = STARTUP_CRASHED;
2947 56 : HandleChildCrash(pid, exitstatus,
2948 56 : _("startup process"));
2949 56 : continue;
2950 : }
2951 :
2952 : /*
2953 : * Startup succeeded, commence normal operations
2954 : */
2955 498 : StartupStatus = STARTUP_NOT_RUNNING;
2956 498 : FatalError = false;
2957 : Assert(AbortStartTime == 0);
2958 498 : ReachedNormalRunning = true;
2959 498 : pmState = PM_RUN;
2960 :
2961 : /*
2962 : * Crank up the background tasks, if we didn't do that already
2963 : * when we entered consistent recovery state. It doesn't matter
2964 : * if this fails, we'll just try again later.
2965 : */
2966 498 : if (CheckpointerPID == 0)
2967 456 : CheckpointerPID = StartCheckpointer();
2968 498 : if (BgWriterPID == 0)
2969 456 : BgWriterPID = StartBackgroundWriter();
2970 498 : if (WalWriterPID == 0)
2971 498 : WalWriterPID = StartWalWriter();
2972 :
2973 : /*
2974 : * Likewise, start other special children as needed. In a restart
2975 : * situation, some of them may be alive already.
2976 : */
2977 498 : if (!IsBinaryUpgrade && AutoVacuumingActive() && AutoVacPID == 0)
2978 480 : AutoVacPID = StartAutoVacLauncher();
2979 498 : if (PgArchStartupAllowed() && PgArchPID == 0)
2980 10 : PgArchPID = pgarch_start();
2981 498 : if (PgStatPID == 0)
2982 456 : PgStatPID = pgstat_start();
2983 :
2984 : /* workers may be scheduled to start now */
2985 498 : maybe_start_bgworkers();
2986 :
2987 : /* at this point we are really open for business */
2988 496 : ereport(LOG,
2989 : (errmsg("database system is ready to accept connections")));
2990 :
2991 : /* Report status */
2992 496 : AddToDataDirLockFile(LOCK_FILE_LINE_PM_STATUS, PM_STATUS_READY);
2993 : #ifdef USE_SYSTEMD
2994 : sd_notify(0, "READY=1");
2995 : #endif
2996 :
2997 496 : continue;
2998 : }
2999 :
3000 : /*
3001 : * Was it the bgwriter? Normal exit can be ignored; we'll start a new
3002 : * one at the next iteration of the postmaster's main loop, if
3003 : * necessary. Any other exit condition is treated as a crash.
3004 : */
3005 12100 : if (pid == BgWriterPID)
3006 : {
3007 572 : BgWriterPID = 0;
3008 572 : if (!EXIT_STATUS_0(exitstatus))
3009 196 : HandleChildCrash(pid, exitstatus,
3010 196 : _("background writer process"));
3011 572 : continue;
3012 : }
3013 :
3014 : /*
3015 : * Was it the checkpointer?
3016 : */
3017 11528 : if (pid == CheckpointerPID)
3018 : {
3019 572 : CheckpointerPID = 0;
3020 572 : if (EXIT_STATUS_0(exitstatus) && pmState == PM_SHUTDOWN)
3021 : {
3022 : /*
3023 : * OK, we saw normal exit of the checkpointer after it's been
3024 : * told to shut down. We expect that it wrote a shutdown
3025 : * checkpoint. (If for some reason it didn't, recovery will
3026 : * occur on next postmaster start.)
3027 : *
3028 : * At this point we should have no normal backend children
3029 : * left (else we'd not be in PM_SHUTDOWN state) but we might
3030 : * have dead_end children to wait for.
3031 : *
3032 : * If we have an archiver subprocess, tell it to do a last
3033 : * archive cycle and quit. Likewise, if we have walsender
3034 : * processes, tell them to send any remaining WAL and quit.
3035 : */
3036 : Assert(Shutdown > NoShutdown);
3037 :
3038 : /* Waken archiver for the last time */
3039 376 : if (PgArchPID != 0)
3040 0 : signal_child(PgArchPID, SIGUSR2);
3041 :
3042 : /*
3043 : * Waken walsenders for the last time. No regular backends
3044 : * should be around anymore.
3045 : */
3046 376 : SignalChildren(SIGUSR2);
3047 :
3048 376 : pmState = PM_SHUTDOWN_2;
3049 :
3050 : /*
3051 : * We can also shut down the stats collector now; there's
3052 : * nothing left for it to do.
3053 : */
3054 752 : if (PgStatPID != 0)
3055 376 : signal_child(PgStatPID, SIGQUIT);
3056 : }
3057 : else
3058 : {
3059 : /*
3060 : * Any unexpected exit of the checkpointer (including FATAL
3061 : * exit) is treated as a crash.
3062 : */
3063 196 : HandleChildCrash(pid, exitstatus,
3064 196 : _("checkpointer process"));
3065 : }
3066 :
3067 572 : continue;
3068 : }
3069 :
3070 : /*
3071 : * Was it the wal writer? Normal exit can be ignored; we'll start a
3072 : * new one at the next iteration of the postmaster's main loop, if
3073 : * necessary. Any other exit condition is treated as a crash.
3074 : */
3075 10956 : if (pid == WalWriterPID)
3076 : {
3077 494 : WalWriterPID = 0;
3078 494 : if (!EXIT_STATUS_0(exitstatus))
3079 140 : HandleChildCrash(pid, exitstatus,
3080 140 : _("WAL writer process"));
3081 494 : continue;
3082 : }
3083 :
3084 : /*
3085 : * Was it the wal receiver? If exit status is zero (normal) or one
3086 : * (FATAL exit), we assume everything is all right just like normal
3087 : * backends. (If we need a new wal receiver, we'll start one at the
3088 : * next iteration of the postmaster's main loop.)
3089 : */
3090 10462 : if (pid == WalReceiverPID)
3091 : {
3092 204 : WalReceiverPID = 0;
3093 204 : if (!EXIT_STATUS_0(exitstatus) && !EXIT_STATUS_1(exitstatus))
3094 20 : HandleChildCrash(pid, exitstatus,
3095 20 : _("WAL receiver process"));
3096 204 : continue;
3097 : }
3098 :
3099 : /*
3100 : * Was it the autovacuum launcher? Normal exit can be ignored; we'll
3101 : * start a new one at the next iteration of the postmaster's main
3102 : * loop, if necessary. Any other exit condition is treated as a
3103 : * crash.
3104 : */
3105 10258 : if (pid == AutoVacPID)
3106 : {
3107 476 : AutoVacPID = 0;
3108 476 : if (!EXIT_STATUS_0(exitstatus))
3109 134 : HandleChildCrash(pid, exitstatus,
3110 134 : _("autovacuum launcher process"));
3111 476 : continue;
3112 : }
3113 :
3114 : /*
3115 : * Was it the archiver? If so, just try to start a new one; no need
3116 : * to force reset of the rest of the system. (If fail, we'll try
3117 : * again in future cycles of the main loop.). Unless we were waiting
3118 : * for it to shut down; don't restart it in that case, and
3119 : * PostmasterStateMachine() will advance to the next shutdown step.
3120 : */
3121 9782 : if (pid == PgArchPID)
3122 : {
3123 10 : PgArchPID = 0;
3124 10 : if (!EXIT_STATUS_0(exitstatus))
3125 10 : LogChildExit(LOG, _("archiver process"),
3126 : pid, exitstatus);
3127 10 : if (PgArchStartupAllowed())
3128 0 : PgArchPID = pgarch_start();
3129 10 : continue;
3130 : }
3131 :
3132 : /*
3133 : * Was it the statistics collector? If so, just try to start a new
3134 : * one; no need to force reset of the rest of the system. (If fail,
3135 : * we'll try again in future cycles of the main loop.)
3136 : */
3137 9772 : if (pid == PgStatPID)
3138 : {
3139 572 : PgStatPID = 0;
3140 572 : if (!EXIT_STATUS_0(exitstatus))
3141 0 : LogChildExit(LOG, _("statistics collector process"),
3142 : pid, exitstatus);
3143 572 : if (pmState == PM_RUN || pmState == PM_HOT_STANDBY)
3144 0 : PgStatPID = pgstat_start();
3145 572 : continue;
3146 : }
3147 :
3148 : /* Was it the system logger? If so, try to start a new one */
3149 9200 : if (pid == SysLoggerPID)
3150 : {
3151 0 : SysLoggerPID = 0;
3152 : /* for safety's sake, launch new logger *first* */
3153 0 : SysLoggerPID = SysLogger_Start();
3154 0 : if (!EXIT_STATUS_0(exitstatus))
3155 0 : LogChildExit(LOG, _("system logger process"),
3156 : pid, exitstatus);
3157 0 : continue;
3158 : }
3159 :
3160 : /* Was it one of our background workers? */
3161 9200 : if (CleanupBackgroundWorker(pid, exitstatus))
3162 : {
3163 : /* have it be restarted */
3164 2276 : HaveCrashedWorker = true;
3165 2276 : continue;
3166 : }
3167 :
3168 : /*
3169 : * Else do standard backend child cleanup.
3170 : */
3171 6924 : CleanupBackend(pid, exitstatus);
3172 : } /* loop over pending child-death reports */
3173 :
3174 : /*
3175 : * After cleaning out the SIGCHLD queue, see if we have any state changes
3176 : * or actions to make.
3177 : */
3178 11462 : PostmasterStateMachine();
3179 :
3180 : /* Done with signal handler */
3181 10894 : PG_SETMASK(&UnBlockSig);
3182 :
3183 10894 : errno = save_errno;
3184 10894 : }
3185 :
3186 : /*
3187 : * Scan the bgworkers list and see if the given PID (which has just stopped
3188 : * or crashed) is in it. Handle its shutdown if so, and return true. If not a
3189 : * bgworker, return false.
3190 : *
3191 : * This is heavily based on CleanupBackend. One important difference is that
3192 : * we don't know yet that the dying process is a bgworker, so we must be silent
3193 : * until we're sure it is.
3194 : */
3195 : static bool
3196 9200 : CleanupBackgroundWorker(int pid,
3197 : int exitstatus) /* child's exit status */
3198 : {
3199 : char namebuf[MAXPGPATH];
3200 : slist_mutable_iter iter;
3201 :
3202 18520 : slist_foreach_modify(iter, &BackgroundWorkerList)
3203 : {
3204 : RegisteredBgWorker *rw;
3205 :
3206 10398 : rw = slist_container(RegisteredBgWorker, rw_lnode, iter.cur);
3207 :
3208 10398 : if (rw->rw_pid != pid)
3209 8122 : continue;
3210 :
3211 : #ifdef WIN32
3212 : /* see CleanupBackend */
3213 : if (exitstatus == ERROR_WAIT_NO_CHILDREN)
3214 : exitstatus = 0;
3215 : #endif
3216 :
3217 2276 : snprintf(namebuf, MAXPGPATH, _("background worker \"%s\""),
3218 2276 : rw->rw_worker.bgw_type);
3219 :
3220 :
3221 2276 : if (!EXIT_STATUS_0(exitstatus))
3222 : {
3223 : /* Record timestamp, so we know when to restart the worker. */
3224 562 : rw->rw_crashed_at = GetCurrentTimestamp();
3225 : }
3226 : else
3227 : {
3228 : /* Zero exit status means terminate */
3229 1714 : rw->rw_crashed_at = 0;
3230 1714 : rw->rw_terminate = true;
3231 : }
3232 :
3233 : /*
3234 : * Additionally, for shared-memory-connected workers, just like a
3235 : * backend, any exit status other than 0 or 1 is considered a crash
3236 : * and causes a system-wide restart.
3237 : */
3238 2276 : if ((rw->rw_worker.bgw_flags & BGWORKER_SHMEM_ACCESS) != 0)
3239 : {
3240 2276 : if (!EXIT_STATUS_0(exitstatus) && !EXIT_STATUS_1(exitstatus))
3241 : {
3242 140 : HandleChildCrash(pid, exitstatus, namebuf);
3243 140 : return true;
3244 : }
3245 : }
3246 :
3247 : /*
3248 : * We must release the postmaster child slot whether this worker is
3249 : * connected to shared memory or not, but we only treat it as a crash
3250 : * if it is in fact connected.
3251 : */
3252 2136 : if (!ReleasePostmasterChildSlot(rw->rw_child_slot) &&
3253 0 : (rw->rw_worker.bgw_flags & BGWORKER_SHMEM_ACCESS) != 0)
3254 : {
3255 0 : HandleChildCrash(pid, exitstatus, namebuf);
3256 0 : return true;
3257 : }
3258 :
3259 : /* Get it out of the BackendList and clear out remaining data */
3260 2136 : dlist_delete(&rw->rw_backend->elem);
3261 : #ifdef EXEC_BACKEND
3262 : ShmemBackendArrayRemove(rw->rw_backend);
3263 : #endif
3264 :
3265 : /*
3266 : * It's possible that this background worker started some OTHER
3267 : * background worker and asked to be notified when that worker started
3268 : * or stopped. If so, cancel any notifications destined for the
3269 : * now-dead backend.
3270 : */
3271 2136 : if (rw->rw_backend->bgworker_notify)
3272 48 : BackgroundWorkerStopNotifications(rw->rw_pid);
3273 2136 : free(rw->rw_backend);
3274 2136 : rw->rw_backend = NULL;
3275 2136 : rw->rw_pid = 0;
3276 2136 : rw->rw_child_slot = 0;
3277 2136 : ReportBackgroundWorkerExit(&iter); /* report child death */
3278 :
3279 2136 : LogChildExit(EXIT_STATUS_0(exitstatus) ? DEBUG1 : LOG,
3280 : namebuf, pid, exitstatus);
3281 :
3282 2136 : return true;
3283 : }
3284 :
3285 6924 : return false;
3286 : }
3287 :
3288 : /*
3289 : * CleanupBackend -- cleanup after terminated backend.
3290 : *
3291 : * Remove all local state associated with backend.
3292 : *
3293 : * If you change this, see also CleanupBackgroundWorker.
3294 : */
3295 : static void
3296 6924 : CleanupBackend(int pid,
3297 : int exitstatus) /* child's exit status. */
3298 : {
3299 : dlist_mutable_iter iter;
3300 :
3301 6924 : LogChildExit(DEBUG2, _("server process"), pid, exitstatus);
3302 :
3303 : /*
3304 : * If a backend dies in an ugly way then we must signal all other backends
3305 : * to quickdie. If exit status is zero (normal) or one (FATAL exit), we
3306 : * assume everything is all right and proceed to remove the backend from
3307 : * the active backend list.
3308 : */
3309 :
3310 : #ifdef WIN32
3311 :
3312 : /*
3313 : * On win32, also treat ERROR_WAIT_NO_CHILDREN (128) as nonfatal case,
3314 : * since that sometimes happens under load when the process fails to start
3315 : * properly (long before it starts using shared memory). Microsoft reports
3316 : * it is related to mutex failure:
3317 : * http://archives.postgresql.org/pgsql-hackers/2010-09/msg00790.php
3318 : */
3319 : if (exitstatus == ERROR_WAIT_NO_CHILDREN)
3320 : {
3321 : LogChildExit(LOG, _("server process"), pid, exitstatus);
3322 : exitstatus = 0;
3323 : }
3324 : #endif
3325 :
3326 6924 : if (!EXIT_STATUS_0(exitstatus) && !EXIT_STATUS_1(exitstatus))
3327 : {
3328 120 : HandleChildCrash(pid, exitstatus, _("server process"));
3329 120 : return;
3330 : }
3331 :
3332 15396 : dlist_foreach_modify(iter, &BackendList)
3333 : {
3334 15396 : Backend *bp = dlist_container(Backend, elem, iter.cur);
3335 :
3336 15396 : if (bp->pid == pid)
3337 : {
3338 6804 : if (!bp->dead_end)
3339 : {
3340 6724 : if (!ReleasePostmasterChildSlot(bp->child_slot))
3341 : {
3342 : /*
3343 : * Uh-oh, the child failed to clean itself up. Treat as a
3344 : * crash after all.
3345 : */
3346 0 : HandleChildCrash(pid, exitstatus, _("server process"));
3347 0 : return;
3348 : }
3349 : #ifdef EXEC_BACKEND
3350 : ShmemBackendArrayRemove(bp);
3351 : #endif
3352 : }
3353 6804 : if (bp->bgworker_notify)
3354 : {
3355 : /*
3356 : * This backend may have been slated to receive SIGUSR1 when
3357 : * some background worker started or stopped. Cancel those
3358 : * notifications, as we don't want to signal PIDs that are not
3359 : * PostgreSQL backends. This gets skipped in the (probably
3360 : * very common) case where the backend has never requested any
3361 : * such notifications.
3362 : */
3363 40 : BackgroundWorkerStopNotifications(bp->pid);
3364 : }
3365 6804 : dlist_delete(iter.cur);
3366 6804 : free(bp);
3367 6804 : break;
3368 : }
3369 : }
3370 : }
3371 :
3372 : /*
3373 : * HandleChildCrash -- cleanup after failed backend, bgwriter, checkpointer,
3374 : * walwriter, autovacuum, or background worker.
3375 : *
3376 : * The objectives here are to clean up our local state about the child
3377 : * process, and to signal all other remaining children to quickdie.
3378 : */
3379 : static void
3380 1002 : HandleChildCrash(int pid, int exitstatus, const char *procname)
3381 : {
3382 : dlist_mutable_iter iter;
3383 : slist_iter siter;
3384 : Backend *bp;
3385 : bool take_action;
3386 :
3387 : /*
3388 : * We only log messages and send signals if this is the first process
3389 : * crash and we're not doing an immediate shutdown; otherwise, we're only
3390 : * here to update postmaster's idea of live processes. If we have already
3391 : * signalled children, nonzero exit status is to be expected, so don't
3392 : * clutter log.
3393 : */
3394 1002 : take_action = !FatalError && Shutdown != ImmediateShutdown;
3395 :
3396 1002 : if (take_action)
3397 : {
3398 4 : LogChildExit(LOG, procname, pid, exitstatus);
3399 4 : ereport(LOG,
3400 : (errmsg("terminating any other active server processes")));
3401 : }
3402 :
3403 : /* Process background workers. */
3404 2004 : slist_foreach(siter, &BackgroundWorkerList)
3405 : {
3406 : RegisteredBgWorker *rw;
3407 :
3408 1002 : rw = slist_container(RegisteredBgWorker, rw_lnode, siter.cur);
3409 1002 : if (rw->rw_pid == 0)
3410 452 : continue; /* not running */
3411 550 : if (rw->rw_pid == pid)
3412 : {
3413 : /*
3414 : * Found entry for freshly-dead worker, so remove it.
3415 : */
3416 140 : (void) ReleasePostmasterChildSlot(rw->rw_child_slot);
3417 140 : dlist_delete(&rw->rw_backend->elem);
3418 : #ifdef EXEC_BACKEND
3419 : ShmemBackendArrayRemove(rw->rw_backend);
3420 : #endif
3421 140 : free(rw->rw_backend);
3422 140 : rw->rw_backend = NULL;
3423 140 : rw->rw_pid = 0;
3424 140 : rw->rw_child_slot = 0;
3425 : /* don't reset crashed_at */
3426 : /* don't report child stop, either */
3427 : /* Keep looping so we can signal remaining workers */
3428 : }
3429 : else
3430 : {
3431 : /*
3432 : * This worker is still alive. Unless we did so already, tell it
3433 : * to commit hara-kiri.
3434 : *
3435 : * SIGQUIT is the special signal that says exit without proc_exit
3436 : * and let the user know what's going on. But if SendStop is set
3437 : * (-s on command line), then we send SIGSTOP instead, so that we
3438 : * can get core dumps from all backends by hand.
3439 : */
3440 410 : if (take_action)
3441 : {
3442 4 : ereport(DEBUG2,
3443 : (errmsg_internal("sending %s to process %d",
3444 : (SendStop ? "SIGSTOP" : "SIGQUIT"),
3445 : (int) rw->rw_pid)));
3446 4 : signal_child(rw->rw_pid, (SendStop ? SIGSTOP : SIGQUIT));
3447 : }
3448 : }
3449 : }
3450 :
3451 : /* Process regular backends */
3452 2070 : dlist_foreach_modify(iter, &BackendList)
3453 : {
3454 1068 : bp = dlist_container(Backend, elem, iter.cur);
3455 :
3456 1068 : if (bp->pid == pid)
3457 : {
3458 : /*
3459 : * Found entry for freshly-dead backend, so remove it.
3460 : */
3461 120 : if (!bp->dead_end)
3462 : {
3463 120 : (void) ReleasePostmasterChildSlot(bp->child_slot);
3464 : #ifdef EXEC_BACKEND
3465 : ShmemBackendArrayRemove(bp);
3466 : #endif
3467 : }
3468 120 : dlist_delete(iter.cur);
3469 120 : free(bp);
3470 : /* Keep looping so we can signal remaining backends */
3471 : }
3472 : else
3473 : {
3474 : /*
3475 : * This backend is still alive. Unless we did so already, tell it
3476 : * to commit hara-kiri.
3477 : *
3478 : * SIGQUIT is the special signal that says exit without proc_exit
3479 : * and let the user know what's going on. But if SendStop is set
3480 : * (-s on command line), then we send SIGSTOP instead, so that we
3481 : * can get core dumps from all backends by hand.
3482 : *
3483 : * We could exclude dead_end children here, but at least in the
3484 : * SIGSTOP case it seems better to include them.
3485 : *
3486 : * Background workers were already processed above; ignore them
3487 : * here.
3488 : */
3489 948 : if (bp->bkend_type == BACKEND_TYPE_BGWORKER)
3490 410 : continue;
3491 :
3492 538 : if (take_action)
3493 : {
3494 4 : ereport(DEBUG2,
3495 : (errmsg_internal("sending %s to process %d",
3496 : (SendStop ? "SIGSTOP" : "SIGQUIT"),
3497 : (int) bp->pid)));
3498 4 : signal_child(bp->pid, (SendStop ? SIGSTOP : SIGQUIT));
3499 : }
3500 : }
3501 : }
3502 :
3503 : /* Take care of the startup process too */
3504 1002 : if (pid == StartupPID)
3505 : {
3506 0 : StartupPID = 0;
3507 0 : StartupStatus = STARTUP_CRASHED;
3508 : }
3509 1002 : else if (StartupPID != 0 && take_action)
3510 : {
3511 0 : ereport(DEBUG2,
3512 : (errmsg_internal("sending %s to process %d",
3513 : (SendStop ? "SIGSTOP" : "SIGQUIT"),
3514 : (int) StartupPID)));
3515 0 : signal_child(StartupPID, (SendStop ? SIGSTOP : SIGQUIT));
3516 0 : StartupStatus = STARTUP_SIGNALED;
3517 : }
3518 :
3519 : /* Take care of the bgwriter too */
3520 1002 : if (pid == BgWriterPID)
3521 0 : BgWriterPID = 0;
3522 1002 : else if (BgWriterPID != 0 && take_action)
3523 : {
3524 4 : ereport(DEBUG2,
3525 : (errmsg_internal("sending %s to process %d",
3526 : (SendStop ? "SIGSTOP" : "SIGQUIT"),
3527 : (int) BgWriterPID)));
3528 4 : signal_child(BgWriterPID, (SendStop ? SIGSTOP : SIGQUIT));
3529 : }
3530 :
3531 : /* Take care of the checkpointer too */
3532 1002 : if (pid == CheckpointerPID)
3533 0 : CheckpointerPID = 0;
3534 1002 : else if (CheckpointerPID != 0 && take_action)
3535 : {
3536 4 : ereport(DEBUG2,
3537 : (errmsg_internal("sending %s to process %d",
3538 : (SendStop ? "SIGSTOP" : "SIGQUIT"),
3539 : (int) CheckpointerPID)));
3540 4 : signal_child(CheckpointerPID, (SendStop ? SIGSTOP : SIGQUIT));
3541 : }
3542 :
3543 : /* Take care of the walwriter too */
3544 1002 : if (pid == WalWriterPID)
3545 0 : WalWriterPID = 0;
3546 1002 : else if (WalWriterPID != 0 && take_action)
3547 : {
3548 4 : ereport(DEBUG2,
3549 : (errmsg_internal("sending %s to process %d",
3550 : (SendStop ? "SIGSTOP" : "SIGQUIT"),
3551 : (int) WalWriterPID)));
3552 4 : signal_child(WalWriterPID, (SendStop ? SIGSTOP : SIGQUIT));
3553 : }
3554 :
3555 : /* Take care of the walreceiver too */
3556 1002 : if (pid == WalReceiverPID)
3557 0 : WalReceiverPID = 0;
3558 1002 : else if (WalReceiverPID != 0 && take_action)
3559 : {
3560 0 : ereport(DEBUG2,
3561 : (errmsg_internal("sending %s to process %d",
3562 : (SendStop ? "SIGSTOP" : "SIGQUIT"),
3563 : (int) WalReceiverPID)));
3564 0 : signal_child(WalReceiverPID, (SendStop ? SIGSTOP : SIGQUIT));
3565 : }
3566 :
3567 : /* Take care of the autovacuum launcher too */
3568 1002 : if (pid == AutoVacPID)
3569 0 : AutoVacPID = 0;
3570 1002 : else if (AutoVacPID != 0 && take_action)
3571 : {
3572 4 : ereport(DEBUG2,
3573 : (errmsg_internal("sending %s to process %d",
3574 : (SendStop ? "SIGSTOP" : "SIGQUIT"),
3575 : (int) AutoVacPID)));
3576 4 : signal_child(AutoVacPID, (SendStop ? SIGSTOP : SIGQUIT));
3577 : }
3578 :
3579 : /*
3580 : * Force a power-cycle of the pgarch process too. (This isn't absolutely
3581 : * necessary, but it seems like a good idea for robustness, and it
3582 : * simplifies the state-machine logic in the case where a shutdown request
3583 : * arrives during crash processing.)
3584 : */
3585 1002 : if (PgArchPID != 0 && take_action)
3586 : {
3587 0 : ereport(DEBUG2,
3588 : (errmsg_internal("sending %s to process %d",
3589 : "SIGQUIT",
3590 : (int) PgArchPID)));
3591 0 : signal_child(PgArchPID, SIGQUIT);
3592 : }
3593 :
3594 : /*
3595 : * Force a power-cycle of the pgstat process too. (This isn't absolutely
3596 : * necessary, but it seems like a good idea for robustness, and it
3597 : * simplifies the state-machine logic in the case where a shutdown request
3598 : * arrives during crash processing.)
3599 : */
3600 1002 : if (PgStatPID != 0 && take_action)
3601 : {
3602 4 : ereport(DEBUG2,
3603 : (errmsg_internal("sending %s to process %d",
3604 : "SIGQUIT",
3605 : (int) PgStatPID)));
3606 4 : signal_child(PgStatPID, SIGQUIT);
3607 4 : allow_immediate_pgstat_restart();
3608 : }
3609 :
3610 : /* We do NOT restart the syslogger */
3611 :
3612 1002 : if (Shutdown != ImmediateShutdown)
3613 28 : FatalError = true;
3614 :
3615 : /* We now transit into a state of waiting for children to die */
3616 2004 : if (pmState == PM_RECOVERY ||
3617 2004 : pmState == PM_HOT_STANDBY ||
3618 2000 : pmState == PM_RUN ||
3619 1996 : pmState == PM_WAIT_BACKUP ||
3620 1996 : pmState == PM_WAIT_READONLY ||
3621 998 : pmState == PM_SHUTDOWN)
3622 4 : pmState = PM_WAIT_BACKENDS;
3623 :
3624 : /*
3625 : * .. and if this doesn't happen quickly enough, now the clock is ticking
3626 : * for us to kill them without mercy.
3627 : */
3628 1002 : if (AbortStartTime == 0)
3629 4 : AbortStartTime = time(NULL);
3630 1002 : }
3631 :
3632 : /*
3633 : * Log the death of a child process.
3634 : */
3635 : static void
3636 9074 : LogChildExit(int lev, const char *procname, int pid, int exitstatus)
3637 : {
3638 : /*
3639 : * size of activity_buffer is arbitrary, but set equal to default
3640 : * track_activity_query_size
3641 : */
3642 : char activity_buffer[1024];
3643 9074 : const char *activity = NULL;
3644 :
3645 9074 : if (!EXIT_STATUS_0(exitstatus))
3646 722 : activity = pgstat_get_crashed_backend_activity(pid,
3647 : activity_buffer,
3648 : sizeof(activity_buffer));
3649 :
3650 9074 : if (WIFEXITED(exitstatus))
3651 9070 : ereport(lev,
3652 :
3653 : /*------
3654 : translator: %s is a noun phrase describing a child process, such as
3655 : "server process" */
3656 : (errmsg("%s (PID %d) exited with exit code %d",
3657 : procname, pid, WEXITSTATUS(exitstatus)),
3658 : activity ? errdetail("Failed process was running: %s", activity) : 0));
3659 4 : else if (WIFSIGNALED(exitstatus))
3660 : {
3661 : #if defined(WIN32)
3662 : ereport(lev,
3663 :
3664 : /*------
3665 : translator: %s is a noun phrase describing a child process, such as
3666 : "server process" */
3667 : (errmsg("%s (PID %d) was terminated by exception 0x%X",
3668 : procname, pid, WTERMSIG(exitstatus)),
3669 : errhint("See C include file \"ntstatus.h\" for a description of the hexadecimal value."),
3670 : activity ? errdetail("Failed process was running: %s", activity) : 0));
3671 : #else
3672 4 : ereport(lev,
3673 :
3674 : /*------
3675 : translator: %s is a noun phrase describing a child process, such as
3676 : "server process" */
3677 : (errmsg("%s (PID %d) was terminated by signal %d: %s",
3678 : procname, pid, WTERMSIG(exitstatus),
3679 : pg_strsignal(WTERMSIG(exitstatus))),
3680 : activity ? errdetail("Failed process was running: %s", activity) : 0));
3681 : #endif
3682 : }
3683 : else
3684 0 : ereport(lev,
3685 :
3686 : /*------
3687 : translator: %s is a noun phrase describing a child process, such as
3688 : "server process" */
3689 : (errmsg("%s (PID %d) exited with unrecognized status %d",
3690 : procname, pid, exitstatus),
3691 : activity ? errdetail("Failed process was running: %s", activity) : 0));
3692 9074 : }
3693 :
3694 : /*
3695 : * Advance the postmaster's state machine and take actions as appropriate
3696 : *
3697 : * This is common code for pmdie(), reaper() and sigusr1_handler(), which
3698 : * receive the signals that might mean we need to change state.
3699 : */
3700 : static void
3701 12538 : PostmasterStateMachine(void)
3702 : {
3703 12538 : if (pmState == PM_WAIT_BACKUP)
3704 : {
3705 : /*
3706 : * PM_WAIT_BACKUP state ends when online backup mode is not active.
3707 : */
3708 8 : if (!BackupInProgress())
3709 8 : pmState = PM_WAIT_BACKENDS;
3710 : }
3711 :
3712 12538 : if (pmState == PM_WAIT_READONLY)
3713 : {
3714 : /*
3715 : * PM_WAIT_READONLY state ends when we have no regular backends that
3716 : * have been started during recovery. We kill the startup and
3717 : * walreceiver processes and transition to PM_WAIT_BACKENDS. Ideally,
3718 : * we might like to kill these processes first and then wait for
3719 : * backends to die off, but that doesn't work at present because
3720 : * killing the startup process doesn't release its locks.
3721 : */
3722 0 : if (CountChildren(BACKEND_TYPE_NORMAL) == 0)
3723 : {
3724 0 : if (StartupPID != 0)
3725 0 : signal_child(StartupPID, SIGTERM);
3726 0 : if (WalReceiverPID != 0)
3727 0 : signal_child(WalReceiverPID, SIGTERM);
3728 0 : pmState = PM_WAIT_BACKENDS;
3729 : }
3730 : }
3731 :
3732 : /*
3733 : * If we are in a state-machine state that implies waiting for backends to
3734 : * exit, see if they're all gone, and change state if so.
3735 : */
3736 12538 : if (pmState == PM_WAIT_BACKENDS)
3737 : {
3738 : /*
3739 : * PM_WAIT_BACKENDS state ends when we have no regular backends
3740 : * (including autovac workers), no bgworkers (including unconnected
3741 : * ones), and no walwriter, autovac launcher or bgwriter. If we are
3742 : * doing crash recovery or an immediate shutdown then we expect the
3743 : * checkpointer to exit as well, otherwise not. The archiver, stats,
3744 : * and syslogger processes are disregarded since they are not
3745 : * connected to shared memory; we also disregard dead_end children
3746 : * here. Walsenders are also disregarded, they will be terminated
3747 : * later after writing the checkpoint record, like the archiver
3748 : * process.
3749 : */
3750 3970 : if (CountChildren(BACKEND_TYPE_NORMAL | BACKEND_TYPE_WORKER) == 0 &&
3751 2348 : StartupPID == 0 &&
3752 2236 : WalReceiverPID == 0 &&
3753 1992 : BgWriterPID == 0 &&
3754 1498 : (CheckpointerPID == 0 ||
3755 2074 : (!FatalError && Shutdown < ImmediateShutdown)) &&
3756 1536 : WalWriterPID == 0 &&
3757 690 : AutoVacPID == 0)
3758 : {
3759 572 : if (Shutdown >= ImmediateShutdown || FatalError)
3760 : {
3761 : /*
3762 : * Start waiting for dead_end children to die. This state
3763 : * change causes ServerLoop to stop creating new ones.
3764 : */
3765 196 : pmState = PM_WAIT_DEAD_END;
3766 :
3767 : /*
3768 : * We already SIGQUIT'd the archiver and stats processes, if
3769 : * any, when we started immediate shutdown or entered
3770 : * FatalError state.
3771 : */
3772 : }
3773 : else
3774 : {
3775 : /*
3776 : * If we get here, we are proceeding with normal shutdown. All
3777 : * the regular children are gone, and it's time to tell the
3778 : * checkpointer to do a shutdown checkpoint.
3779 : */
3780 : Assert(Shutdown > NoShutdown);
3781 : /* Start the checkpointer if not running */
3782 376 : if (CheckpointerPID == 0)
3783 0 : CheckpointerPID = StartCheckpointer();
3784 : /* And tell it to shut down */
3785 376 : if (CheckpointerPID != 0)
3786 : {
3787 376 : signal_child(CheckpointerPID, SIGUSR2);
3788 376 : pmState = PM_SHUTDOWN;
3789 : }
3790 : else
3791 : {
3792 : /*
3793 : * If we failed to fork a checkpointer, just shut down.
3794 : * Any required cleanup will happen at next restart. We
3795 : * set FatalError so that an "abnormal shutdown" message
3796 : * gets logged when we exit.
3797 : */
3798 0 : FatalError = true;
3799 0 : pmState = PM_WAIT_DEAD_END;
3800 :
3801 : /* Kill the walsenders, archiver and stats collector too */
3802 0 : SignalChildren(SIGQUIT);
3803 0 : if (PgArchPID != 0)
3804 0 : signal_child(PgArchPID, SIGQUIT);
3805 0 : if (PgStatPID != 0)
3806 0 : signal_child(PgStatPID, SIGQUIT);
3807 : }
3808 : }
3809 : }
3810 : }
3811 :
3812 12538 : if (pmState == PM_SHUTDOWN_2)
3813 : {
3814 : /*
3815 : * PM_SHUTDOWN_2 state ends when there's no other children than
3816 : * dead_end children left. There shouldn't be any regular backends
3817 : * left by now anyway; what we're really waiting for is walsenders and
3818 : * archiver.
3819 : */
3820 432 : if (PgArchPID == 0 && CountChildren(BACKEND_TYPE_ALL) == 0)
3821 : {
3822 376 : pmState = PM_WAIT_DEAD_END;
3823 : }
3824 : }
3825 :
3826 12538 : if (pmState == PM_WAIT_DEAD_END)
3827 : {
3828 : /*
3829 : * PM_WAIT_DEAD_END state ends when the BackendList is entirely empty
3830 : * (ie, no dead_end children remain), and the archiver and stats
3831 : * collector are gone too.
3832 : *
3833 : * The reason we wait for those two is to protect them against a new
3834 : * postmaster starting conflicting subprocesses; this isn't an
3835 : * ironclad protection, but it at least helps in the
3836 : * shutdown-and-immediately-restart scenario. Note that they have
3837 : * already been sent appropriate shutdown signals, either during a
3838 : * normal state transition leading up to PM_WAIT_DEAD_END, or during
3839 : * FatalError processing.
3840 : */
3841 2274 : if (dlist_is_empty(&BackendList) &&
3842 2260 : PgArchPID == 0 && PgStatPID == 0)
3843 : {
3844 : /* These other guys should be dead already */
3845 : Assert(StartupPID == 0);
3846 : Assert(WalReceiverPID == 0);
3847 : Assert(BgWriterPID == 0);
3848 : Assert(CheckpointerPID == 0);
3849 : Assert(WalWriterPID == 0);
3850 : Assert(AutoVacPID == 0);
3851 : /* syslogger is not considered here */
3852 572 : pmState = PM_NO_CHILDREN;
3853 : }
3854 : }
3855 :
3856 : /*
3857 : * If we've been told to shut down, we exit as soon as there are no
3858 : * remaining children. If there was a crash, cleanup will occur at the
3859 : * next startup. (Before PostgreSQL 8.3, we tried to recover from the
3860 : * crash before exiting, but that seems unwise if we are quitting because
3861 : * we got SIGTERM from init --- there may well not be time for recovery
3862 : * before init decides to SIGKILL us.)
3863 : *
3864 : * Note that the syslogger continues to run. It will exit when it sees
3865 : * EOF on its input pipe, which happens when there are no more upstream
3866 : * processes.
3867 : */
3868 12538 : if (Shutdown > NoShutdown && pmState == PM_NO_CHILDREN)
3869 : {
3870 568 : if (FatalError)
3871 : {
3872 0 : ereport(LOG, (errmsg("abnormal database system shutdown")));
3873 0 : ExitPostmaster(1);
3874 : }
3875 : else
3876 : {
3877 : /*
3878 : * Terminate exclusive backup mode to avoid recovery after a clean
3879 : * fast shutdown. Since an exclusive backup can only be taken
3880 : * during normal running (and not, for example, while running
3881 : * under Hot Standby) it only makes sense to do this if we reached
3882 : * normal running. If we're still in recovery, the backup file is
3883 : * one we're recovering *from*, and we must keep it around so that
3884 : * recovery restarts from the right place.
3885 : */
3886 568 : if (ReachedNormalRunning)
3887 490 : CancelBackup();
3888 :
3889 : /* Normal exit from the postmaster is here */
3890 568 : ExitPostmaster(0);
3891 : }
3892 : }
3893 :
3894 : /*
3895 : * If the startup process failed, or the user does not want an automatic
3896 : * restart after backend crashes, wait for all non-syslogger children to
3897 : * exit, and then exit postmaster. We don't try to reinitialize when the
3898 : * startup process fails, because more than likely it will just fail again
3899 : * and we will keep trying forever.
3900 : */
3901 11974 : if (pmState == PM_NO_CHILDREN &&
3902 8 : (StartupStatus == STARTUP_CRASHED || !restart_after_crash))
3903 0 : ExitPostmaster(1);
3904 :
3905 : /*
3906 : * If we need to recover from a crash, wait for all non-syslogger children
3907 : * to exit, then reset shmem and StartupDataBase.
3908 : */
3909 11970 : if (FatalError && pmState == PM_NO_CHILDREN)
3910 : {
3911 4 : ereport(LOG,
3912 : (errmsg("all server processes terminated; reinitializing")));
3913 :
3914 : /* allow background workers to immediately restart */
3915 4 : ResetBackgroundWorkerCrashTimes();
3916 :
3917 4 : shmem_exit(1);
3918 :
3919 : /* re-read control file into local memory */
3920 4 : LocalProcessControlFile(true);
3921 :
3922 4 : reset_shared(PostPortNumber);
3923 :
3924 4 : StartupPID = StartupDataBase();
3925 : Assert(StartupPID != 0);
3926 4 : StartupStatus = STARTUP_RUNNING;
3927 4 : pmState = PM_STARTUP;
3928 : /* crash recovery started, reset SIGKILL flag */
3929 4 : AbortStartTime = 0;
3930 : }
3931 11970 : }
3932 :
3933 :
3934 : /*
3935 : * Send a signal to a postmaster child process
3936 : *
3937 : * On systems that have setsid(), each child process sets itself up as a
3938 : * process group leader. For signals that are generally interpreted in the
3939 : * appropriate fashion, we signal the entire process group not just the
3940 : * direct child process. This allows us to, for example, SIGQUIT a blocked
3941 : * archive_recovery script, or SIGINT a script being run by a backend via
3942 : * system().
3943 : *
3944 : * There is a race condition for recently-forked children: they might not
3945 : * have executed setsid() yet. So we signal the child directly as well as
3946 : * the group. We assume such a child will handle the signal before trying
3947 : * to spawn any grandchild processes. We also assume that signaling the
3948 : * child twice will not cause any problems.
3949 : */
3950 : static void
3951 4146 : signal_child(pid_t pid, int signal)
3952 : {
3953 4146 : if (kill(pid, signal) < 0)
3954 0 : elog(DEBUG3, "kill(%ld,%d) failed: %m", (long) pid, signal);
3955 : #ifdef HAVE_SETSID
3956 4146 : switch (signal)
3957 : {
3958 : case SIGINT:
3959 : case SIGTERM:
3960 : case SIGQUIT:
3961 : case SIGSTOP:
3962 : case SIGKILL:
3963 3280 : if (kill(-pid, signal) < 0)
3964 8 : elog(DEBUG3, "kill(%ld,%d) failed: %m", (long) (-pid), signal);
3965 3280 : break;
3966 : default:
3967 866 : break;
3968 : }
3969 : #endif
3970 4146 : }
3971 :
3972 : /*
3973 : * Send a signal to the targeted children (but NOT special children;
3974 : * dead_end children are never signaled, either).
3975 : */
3976 : static bool
3977 992 : SignalSomeChildren(int signal, int target)
3978 : {
3979 : dlist_iter iter;
3980 992 : bool signaled = false;
3981 :
3982 2048 : dlist_foreach(iter, &BackendList)
3983 : {
3984 1056 : Backend *bp = dlist_container(Backend, elem, iter.cur);
3985 :
3986 1056 : if (bp->dead_end)
3987 0 : continue;
3988 :
3989 : /*
3990 : * Since target == BACKEND_TYPE_ALL is the most common case, we test
3991 : * it first and avoid touching shared memory for every child.
3992 : */
3993 1056 : if (target != BACKEND_TYPE_ALL)
3994 : {
3995 : /*
3996 : * Assign bkend_type for any recently announced WAL Sender
3997 : * processes.
3998 : */
3999 874 : if (bp->bkend_type == BACKEND_TYPE_NORMAL &&
4000 248 : IsPostmasterChildWalSender(bp->child_slot))
4001 34 : bp->bkend_type = BACKEND_TYPE_WALSND;
4002 :
4003 626 : if (!(target & bp->bkend_type))
4004 42 : continue;
4005 : }
4006 :
4007 1014 : ereport(DEBUG4,
4008 : (errmsg_internal("sending signal %d to process %d",
4009 : signal, (int) bp->pid)));
4010 1014 : signal_child(bp->pid, signal);
4011 1014 : signaled = true;
4012 : }
4013 992 : return signaled;
4014 : }
4015 :
4016 : /*
4017 : * Send a termination signal to children. This considers all of our children
4018 : * processes, except syslogger and dead_end backends.
4019 : */
4020 : static void
4021 192 : TerminateChildren(int signal)
4022 : {
4023 192 : SignalChildren(signal);
4024 192 : if (StartupPID != 0)
4025 : {
4026 56 : signal_child(StartupPID, signal);
4027 56 : if (signal == SIGQUIT || signal == SIGKILL)
4028 56 : StartupStatus = STARTUP_SIGNALED;
4029 : }
4030 192 : if (BgWriterPID != 0)
4031 192 : signal_child(BgWriterPID, signal);
4032 192 : if (CheckpointerPID != 0)
4033 192 : signal_child(CheckpointerPID, signal);
4034 192 : if (WalWriterPID != 0)
4035 136 : signal_child(WalWriterPID, signal);
4036 192 : if (WalReceiverPID != 0)
4037 20 : signal_child(WalReceiverPID, signal);
4038 192 : if (AutoVacPID != 0)
4039 130 : signal_child(AutoVacPID, signal);
4040 192 : if (PgArchPID != 0)
4041 10 : signal_child(PgArchPID, signal);
4042 192 : if (PgStatPID != 0)
4043 192 : signal_child(PgStatPID, signal);
4044 192 : }
4045 :
4046 : /*
4047 : * BackendStartup -- start backend process
4048 : *
4049 : * returns: STATUS_ERROR if the fork failed, STATUS_OK otherwise.
4050 : *
4051 : * Note: if you change this code, also consider StartAutovacuumWorker.
4052 : */
4053 : static int
4054 6870 : BackendStartup(Port *port)
4055 : {
4056 : Backend *bn; /* for backend cleanup */
4057 : pid_t pid;
4058 :
4059 : /*
4060 : * Create backend data structure. Better before the fork() so we can
4061 : * handle failure cleanly.
4062 : */
4063 6870 : bn = (Backend *) malloc(sizeof(Backend));
4064 6870 : if (!bn)
4065 : {
4066 0 : ereport(LOG,
4067 : (errcode(ERRCODE_OUT_OF_MEMORY),
4068 : errmsg("out of memory")));
4069 0 : return STATUS_ERROR;
4070 : }
4071 :
4072 : /*
4073 : * Compute the cancel key that will be assigned to this backend. The
4074 : * backend will have its own copy in the forked-off process' value of
4075 : * MyCancelKey, so that it can transmit the key to the frontend.
4076 : */
4077 6870 : if (!RandomCancelKey(&MyCancelKey))
4078 : {
4079 0 : free(bn);
4080 0 : ereport(LOG,
4081 : (errcode(ERRCODE_INTERNAL_ERROR),
4082 : errmsg("could not generate random cancel key")));
4083 0 : return STATUS_ERROR;
4084 : }
4085 :
4086 6870 : bn->cancel_key = MyCancelKey;
4087 :
4088 : /* Pass down canAcceptConnections state */
4089 6870 : port->canAcceptConnections = canAcceptConnections();
4090 6950 : bn->dead_end = (port->canAcceptConnections != CAC_OK &&
4091 80 : port->canAcceptConnections != CAC_WAITBACKUP);
4092 :
4093 : /*
4094 : * Unless it's a dead_end child, assign it a child slot number
4095 : */
4096 6870 : if (!bn->dead_end)
4097 6790 : bn->child_slot = MyPMChildSlot = AssignPostmasterChildSlot();
4098 : else
4099 80 : bn->child_slot = 0;
4100 :
4101 : /* Hasn't asked to be notified about any bgworkers yet */
4102 6870 : bn->bgworker_notify = false;
4103 :
4104 : #ifdef EXEC_BACKEND
4105 : pid = backend_forkexec(port);
4106 : #else /* !EXEC_BACKEND */
4107 6870 : pid = fork_process();
4108 13626 : if (pid == 0) /* child */
4109 : {
4110 6758 : free(bn);
4111 :
4112 : /* Detangle from postmaster */
4113 6758 : InitPostmasterChild();
4114 :
4115 : /* Close the postmaster's sockets */
4116 6758 : ClosePostmasterPorts(false);
4117 :
4118 : /* Perform additional initialization and collect startup packet */
4119 6758 : BackendInitialize(port);
4120 :
4121 : /* And run the backend */
4122 6642 : BackendRun(port);
4123 : }
4124 : #endif /* EXEC_BACKEND */
4125 :
4126 6868 : if (pid < 0)
4127 : {
4128 : /* in parent, fork failed */
4129 0 : int save_errno = errno;
4130 :
4131 0 : if (!bn->dead_end)
4132 0 : (void) ReleasePostmasterChildSlot(bn->child_slot);
4133 0 : free(bn);
4134 0 : errno = save_errno;
4135 0 : ereport(LOG,
4136 : (errmsg("could not fork new process for connection: %m")));
4137 0 : report_fork_failure_to_client(port, save_errno);
4138 0 : return STATUS_ERROR;
4139 : }
4140 :
4141 : /* in parent, successful fork */
4142 6868 : ereport(DEBUG2,
4143 : (errmsg_internal("forked new backend, pid=%d socket=%d",
4144 : (int) pid, (int) port->sock)));
4145 :
4146 : /*
4147 : * Everything's been successful, it's safe to add this backend to our list
4148 : * of backends.
4149 : */
4150 6868 : bn->pid = pid;
4151 6868 : bn->bkend_type = BACKEND_TYPE_NORMAL; /* Can change later to WALSND */
4152 6868 : dlist_push_head(&BackendList, &bn->elem);
4153 :
4154 : #ifdef EXEC_BACKEND
4155 : if (!bn->dead_end)
4156 : ShmemBackendArrayAdd(bn);
4157 : #endif
4158 :
4159 6868 : return STATUS_OK;
4160 : }
4161 :
4162 : /*
4163 : * Try to report backend fork() failure to client before we close the
4164 : * connection. Since we do not care to risk blocking the postmaster on
4165 : * this connection, we set the connection to non-blocking and try only once.
4166 : *
4167 : * This is grungy special-purpose code; we cannot use backend libpq since
4168 : * it's not up and running.
4169 : */
4170 : static void
4171 0 : report_fork_failure_to_client(Port *port, int errnum)
4172 : {
4173 : char buffer[1000];
4174 : int rc;
4175 :
4176 : /* Format the error message packet (always V2 protocol) */
4177 0 : snprintf(buffer, sizeof(buffer), "E%s%s\n",
4178 : _("could not fork new process for connection: "),
4179 : strerror(errnum));
4180 :
4181 : /* Set port to non-blocking. Don't do send() if this fails */
4182 0 : if (!pg_set_noblock(port->sock))
4183 0 : return;
4184 :
4185 : /* We'll retry after EINTR, but ignore all other failures */
4186 : do
4187 : {
4188 0 : rc = send(port->sock, buffer, strlen(buffer) + 1, 0);
4189 0 : } while (rc < 0 && errno == EINTR);
4190 : }
4191 :
4192 :
4193 : /*
4194 : * BackendInitialize -- initialize an interactive (postmaster-child)
4195 : * backend process, and collect the client's startup packet.
4196 : *
4197 : * returns: nothing. Will not return at all if there's any failure.
4198 : *
4199 : * Note: this code does not depend on having any access to shared memory.
4200 : * In the EXEC_BACKEND case, we are physically attached to shared memory
4201 : * but have not yet set up most of our local pointers to shmem structures.
4202 : */
4203 : static void
4204 6758 : BackendInitialize(Port *port)
4205 : {
4206 : int status;
4207 : int ret;
4208 : char remote_host[NI_MAXHOST];
4209 : char remote_port[NI_MAXSERV];
4210 : char remote_ps_data[NI_MAXHOST];
4211 :
4212 : /* Save port etc. for ps status */
4213 6758 : MyProcPort = port;
4214 :
4215 : /*
4216 : * PreAuthDelay is a debugging aid for investigating problems in the
4217 : * authentication cycle: it can be set in postgresql.conf to allow time to
4218 : * attach to the newly-forked backend with a debugger. (See also
4219 : * PostAuthDelay, which we allow clients to pass through PGOPTIONS, but it
4220 : * is not honored until after authentication.)
4221 : */
4222 6758 : if (PreAuthDelay > 0)
4223 0 : pg_usleep(PreAuthDelay * 1000000L);
4224 :
4225 : /* This flag will remain set until InitPostgres finishes authentication */
4226 6758 : ClientAuthInProgress = true; /* limit visibility of log messages */
4227 :
4228 : /* set these to empty in case they are needed before we set them up */
4229 6758 : port->remote_host = "";
4230 6758 : port->remote_port = "";
4231 :
4232 : /*
4233 : * Initialize libpq and enable reporting of ereport errors to the client.
4234 : * Must do this now because authentication uses libpq to send messages.
4235 : */
4236 6758 : pq_init(); /* initialize libpq to talk to client */
4237 6758 : whereToSendOutput = DestRemote; /* now safe to ereport to client */
4238 :
4239 : /*
4240 : * We arrange for a simple exit(1) if we receive SIGTERM or SIGQUIT or
4241 : * timeout while trying to collect the startup packet. Otherwise the
4242 : * postmaster cannot shutdown the database FAST or IMMED cleanly if a
4243 : * buggy client fails to send the packet promptly. XXX it follows that
4244 : * the remainder of this function must tolerate losing control at any
4245 : * instant. Likewise, any pg_on_exit_callback registered before or during
4246 : * this function must be prepared to execute at any instant between here
4247 : * and the end of this function. Furthermore, affected callbacks execute
4248 : * partially or not at all when a second exit-inducing signal arrives
4249 : * after proc_exit_prepare() decrements on_proc_exit_index. (Thanks to
4250 : * that mechanic, callbacks need not anticipate more than one call.) This
4251 : * is fragile; it ought to instead follow the norm of handling interrupts
4252 : * at selected, safe opportunities.
4253 : */
4254 6758 : pqsignal(SIGTERM, startup_die);
4255 6758 : pqsignal(SIGQUIT, startup_die);
4256 6758 : InitializeTimeouts(); /* establishes SIGALRM handler */
4257 6758 : PG_SETMASK(&StartupBlockSig);
4258 :
4259 : /*
4260 : * Get the remote host name and port for logging and status display.
4261 : */
4262 6756 : remote_host[0] = '\0';
4263 6756 : remote_port[0] = '\0';
4264 6756 : if ((ret = pg_getnameinfo_all(&port->raddr.addr, port->raddr.salen,
4265 : remote_host, sizeof(remote_host),
4266 : remote_port, sizeof(remote_port),
4267 : (log_hostname ? 0 : NI_NUMERICHOST) | NI_NUMERICSERV)) != 0)
4268 0 : ereport(WARNING,
4269 : (errmsg_internal("pg_getnameinfo_all() failed: %s",
4270 : gai_strerror(ret))));
4271 6756 : if (remote_port[0] == '\0')
4272 6374 : snprintf(remote_ps_data, sizeof(remote_ps_data), "%s", remote_host);
4273 : else
4274 382 : snprintf(remote_ps_data, sizeof(remote_ps_data), "%s(%s)", remote_host, remote_port);
4275 :
4276 : /*
4277 : * Save remote_host and remote_port in port structure (after this, they
4278 : * will appear in log_line_prefix data for log messages).
4279 : */
4280 6756 : port->remote_host = strdup(remote_host);
4281 6756 : port->remote_port = strdup(remote_port);
4282 :
4283 : /* And now we can issue the Log_connections message, if wanted */
4284 6756 : if (Log_connections)
4285 : {
4286 106 : if (remote_port[0])
4287 86 : ereport(LOG,
4288 : (errmsg("connection received: host=%s port=%s",
4289 : remote_host,
4290 : remote_port)));
4291 : else
4292 20 : ereport(LOG,
4293 : (errmsg("connection received: host=%s",
4294 : remote_host)));
4295 : }
4296 :
4297 : /*
4298 : * If we did a reverse lookup to name, we might as well save the results
4299 : * rather than possibly repeating the lookup during authentication.
4300 : *
4301 : * Note that we don't want to specify NI_NAMEREQD above, because then we'd
4302 : * get nothing useful for a client without an rDNS entry. Therefore, we
4303 : * must check whether we got a numeric IPv4 or IPv6 address, and not save
4304 : * it into remote_hostname if so. (This test is conservative and might
4305 : * sometimes classify a hostname as numeric, but an error in that
4306 : * direction is safe; it only results in a possible extra lookup.)
4307 : */
4308 6756 : if (log_hostname &&
4309 86 : ret == 0 &&
4310 172 : strspn(remote_host, "0123456789.") < strlen(remote_host) &&
4311 86 : strspn(remote_host, "0123456789ABCDEFabcdef:") < strlen(remote_host))
4312 86 : port->remote_hostname = strdup(remote_host);
4313 :
4314 : /*
4315 : * Ready to begin client interaction. We will give up and exit(1) after a
4316 : * time delay, so that a broken client can't hog a connection
4317 : * indefinitely. PreAuthDelay and any DNS interactions above don't count
4318 : * against the time limit.
4319 : *
4320 : * Note: AuthenticationTimeout is applied here while waiting for the
4321 : * startup packet, and then again in InitPostgres for the duration of any
4322 : * authentication operations. So a hostile client could tie up the
4323 : * process for nearly twice AuthenticationTimeout before we kick him off.
4324 : *
4325 : * Note: because PostgresMain will call InitializeTimeouts again, the
4326 : * registration of STARTUP_PACKET_TIMEOUT will be lost. This is okay
4327 : * since we never use it again after this function.
4328 : */
4329 6756 : RegisterTimeout(STARTUP_PACKET_TIMEOUT, StartupPacketTimeoutHandler);
4330 6756 : enable_timeout_after(STARTUP_PACKET_TIMEOUT, AuthenticationTimeout * 1000);
4331 :
4332 : /*
4333 : * Receive the startup packet (which might turn out to be a cancel request
4334 : * packet).
4335 : */
4336 6756 : status = ProcessStartupPacket(port, false);
4337 :
4338 : /*
4339 : * Stop here if it was bad or a cancel packet. ProcessStartupPacket
4340 : * already did any appropriate error reporting.
4341 : */
4342 6676 : if (status != STATUS_OK)
4343 34 : proc_exit(0);
4344 :
4345 : /*
4346 : * Now that we have the user and database name, we can set the process
4347 : * title for ps. It's good to do this as early as possible in startup.
4348 : *
4349 : * For a walsender, the ps display is set in the following form:
4350 : *
4351 : * postgres: walsender <user> <host> <activity>
4352 : *
4353 : * To achieve that, we pass "walsender" as username and username as dbname
4354 : * to init_ps_display(). XXX: should add a new variant of
4355 : * init_ps_display() to avoid abusing the parameters like this.
4356 : */
4357 6642 : if (am_walsender)
4358 466 : init_ps_display(pgstat_get_backend_desc(B_WAL_SENDER), port->user_name, remote_ps_data,
4359 466 : update_process_title ? "authentication" : "");
4360 : else
4361 6176 : init_ps_display(port->user_name, port->database_name, remote_ps_data,
4362 6176 : update_process_title ? "authentication" : "");
4363 :
4364 : /*
4365 : * Disable the timeout, and prevent SIGTERM/SIGQUIT again.
4366 : */
4367 6642 : disable_timeout(STARTUP_PACKET_TIMEOUT, false);
4368 6642 : PG_SETMASK(&BlockSig);
4369 6642 : }
4370 :
4371 :
4372 : /*
4373 : * BackendRun -- set up the backend's argument list and invoke PostgresMain()
4374 : *
4375 : * returns:
4376 : * Shouldn't return at all.
4377 : * If PostgresMain() fails, return status.
4378 : */
4379 : static void
4380 6642 : BackendRun(Port *port)
4381 : {
4382 : char **av;
4383 : int maxac;
4384 : int ac;
4385 : int i;
4386 :
4387 : /*
4388 : * Now, build the argv vector that will be given to PostgresMain.
4389 : *
4390 : * The maximum possible number of commandline arguments that could come
4391 : * from ExtraOptions is (strlen(ExtraOptions) + 1) / 2; see
4392 : * pg_split_opts().
4393 : */
4394 6642 : maxac = 2; /* for fixed args supplied below */
4395 6642 : maxac += (strlen(ExtraOptions) + 1) / 2;
4396 :
4397 6642 : av = (char **) MemoryContextAlloc(TopMemoryContext,
4398 : maxac * sizeof(char *));
4399 6642 : ac = 0;
4400 :
4401 6642 : av[ac++] = "postgres";
4402 :
4403 : /*
4404 : * Pass any backend switches specified with -o on the postmaster's own
4405 : * command line. We assume these are secure.
4406 : */
4407 6642 : pg_split_opts(av, &ac, ExtraOptions);
4408 :
4409 6642 : av[ac] = NULL;
4410 :
4411 : Assert(ac < maxac);
4412 :
4413 : /*
4414 : * Debug: print arguments being passed to backend
4415 : */
4416 6642 : ereport(DEBUG3,
4417 : (errmsg_internal("%s child[%d]: starting with (",
4418 : progname, (int) getpid())));
4419 13284 : for (i = 0; i < ac; ++i)
4420 6642 : ereport(DEBUG3,
4421 : (errmsg_internal("\t%s", av[i])));
4422 6642 : ereport(DEBUG3,
4423 : (errmsg_internal(")")));
4424 :
4425 : /*
4426 : * Make sure we aren't in PostmasterContext anymore. (We can't delete it
4427 : * just yet, though, because InitPostgres will need the HBA data.)
4428 : */
4429 6642 : MemoryContextSwitchTo(TopMemoryContext);
4430 :
4431 6642 : PostgresMain(ac, av, port->database_name, port->user_name);
4432 : }
4433 :
4434 :
4435 : #ifdef EXEC_BACKEND
4436 :
4437 : /*
4438 : * postmaster_forkexec -- fork and exec a postmaster subprocess
4439 : *
4440 : * The caller must have set up the argv array already, except for argv[2]
4441 : * which will be filled with the name of the temp variable file.
4442 : *
4443 : * Returns the child process PID, or -1 on fork failure (a suitable error
4444 : * message has been logged on failure).
4445 : *
4446 : * All uses of this routine will dispatch to SubPostmasterMain in the
4447 : * child process.
4448 : */
4449 : pid_t
4450 : postmaster_forkexec(int argc, char *argv[])
4451 : {
4452 : Port port;
4453 :
4454 : /* This entry point passes dummy values for the Port variables */
4455 : memset(&port, 0, sizeof(port));
4456 : return internal_forkexec(argc, argv, &port);
4457 : }
4458 :
4459 : /*
4460 : * backend_forkexec -- fork/exec off a backend process
4461 : *
4462 : * Some operating systems (WIN32) don't have fork() so we have to simulate
4463 : * it by storing parameters that need to be passed to the child and
4464 : * then create a new child process.
4465 : *
4466 : * returns the pid of the fork/exec'd process, or -1 on failure
4467 : */
4468 : static pid_t
4469 : backend_forkexec(Port *port)
4470 : {
4471 : char *av[4];
4472 : int ac = 0;
4473 :
4474 : av[ac++] = "postgres";
4475 : av[ac++] = "--forkbackend";
4476 : av[ac++] = NULL; /* filled in by internal_forkexec */
4477 :
4478 : av[ac] = NULL;
4479 : Assert(ac < lengthof(av));
4480 :
4481 : return internal_forkexec(ac, av, port);
4482 : }
4483 :
4484 : #ifndef WIN32
4485 :
4486 : /*
4487 : * internal_forkexec non-win32 implementation
4488 : *
4489 : * - writes out backend variables to the parameter file
4490 : * - fork():s, and then exec():s the child process
4491 : */
4492 : static pid_t
4493 : internal_forkexec(int argc, char *argv[], Port *port)
4494 : {
4495 : static unsigned long tmpBackendFileNum = 0;
4496 : pid_t pid;
4497 : char tmpfilename[MAXPGPATH];
4498 : BackendParameters param;
4499 : FILE *fp;
4500 :
4501 : if (!save_backend_variables(¶m, port))
4502 : return -1; /* log made by save_backend_variables */
4503 :
4504 : /* Calculate name for temp file */
4505 : snprintf(tmpfilename, MAXPGPATH, "%s/%s.backend_var.%d.%lu",
4506 : PG_TEMP_FILES_DIR, PG_TEMP_FILE_PREFIX,
4507 : MyProcPid, ++tmpBackendFileNum);
4508 :
4509 : /* Open file */
4510 : fp = AllocateFile(tmpfilename, PG_BINARY_W);
4511 : if (!fp)
4512 : {
4513 : /*
4514 : * As in OpenTemporaryFileInTablespace, try to make the temp-file
4515 : * directory, ignoring errors.
4516 : */
4517 : (void) MakePGDirectory(PG_TEMP_FILES_DIR);
4518 :
4519 : fp = AllocateFile(tmpfilename, PG_BINARY_W);
4520 : if (!fp)
4521 : {
4522 : ereport(LOG,
4523 : (errcode_for_file_access(),
4524 : errmsg("could not create file \"%s\": %m",
4525 : tmpfilename)));
4526 : return -1;
4527 : }
4528 : }
4529 :
4530 : if (fwrite(¶m, sizeof(param), 1, fp) != 1)
4531 : {
4532 : ereport(LOG,
4533 : (errcode_for_file_access(),
4534 : errmsg("could not write to file \"%s\": %m", tmpfilename)));
4535 : FreeFile(fp);
4536 : return -1;
4537 : }
4538 :
4539 : /* Release file */
4540 : if (FreeFile(fp))
4541 : {
4542 : ereport(LOG,
4543 : (errcode_for_file_access(),
4544 : errmsg("could not write to file \"%s\": %m", tmpfilename)));
4545 : return -1;
4546 : }
4547 :
4548 : /* Make sure caller set up argv properly */
4549 : Assert(argc >= 3);
4550 : Assert(argv[argc] == NULL);
4551 : Assert(strncmp(argv[1], "--fork", 6) == 0);
4552 : Assert(argv[2] == NULL);
4553 :
4554 : /* Insert temp file name after --fork argument */
4555 : argv[2] = tmpfilename;
4556 :
4557 : /* Fire off execv in child */
4558 : if ((pid = fork_process()) == 0)
4559 : {
4560 : if (execv(postgres_exec_path, argv) < 0)
4561 : {
4562 : ereport(LOG,
4563 : (errmsg("could not execute server process \"%s\": %m",
4564 : postgres_exec_path)));
4565 : /* We're already in the child process here, can't return */
4566 : exit(1);
4567 : }
4568 : }
4569 :
4570 : return pid; /* Parent returns pid, or -1 on fork failure */
4571 : }
4572 : #else /* WIN32 */
4573 :
4574 : /*
4575 : * internal_forkexec win32 implementation
4576 : *
4577 : * - starts backend using CreateProcess(), in suspended state
4578 : * - writes out backend variables to the parameter file
4579 : * - during this, duplicates handles and sockets required for
4580 : * inheritance into the new process
4581 : * - resumes execution of the new process once the backend parameter
4582 : * file is complete.
4583 : */
4584 : static pid_t
4585 : internal_forkexec(int argc, char *argv[], Port *port)
4586 : {
4587 : int retry_count = 0;
4588 : STARTUPINFO si;
4589 : PROCESS_INFORMATION pi;
4590 : int i;
4591 : int j;
4592 : char cmdLine[MAXPGPATH * 2];
4593 : HANDLE paramHandle;
4594 : BackendParameters *param;
4595 : SECURITY_ATTRIBUTES sa;
4596 : char paramHandleStr[32];
4597 : win32_deadchild_waitinfo *childinfo;
4598 :
4599 : /* Make sure caller set up argv properly */
4600 : Assert(argc >= 3);
4601 : Assert(argv[argc] == NULL);
4602 : Assert(strncmp(argv[1], "--fork", 6) == 0);
4603 : Assert(argv[2] == NULL);
4604 :
4605 : /* Resume here if we need to retry */
4606 : retry:
4607 :
4608 : /* Set up shared memory for parameter passing */
4609 : ZeroMemory(&sa, sizeof(sa));
4610 : sa.nLength = sizeof(sa);
4611 : sa.bInheritHandle = TRUE;
4612 : paramHandle = CreateFileMapping(INVALID_HANDLE_VALUE,
4613 : &sa,
4614 : PAGE_READWRITE,
4615 : 0,
4616 : sizeof(BackendParameters),
4617 : NULL);
4618 : if (paramHandle == INVALID_HANDLE_VALUE)
4619 : {
4620 : elog(LOG, "could not create backend parameter file mapping: error code %lu",
4621 : GetLastError());
4622 : return -1;
4623 : }
4624 :
4625 : param = MapViewOfFile(paramHandle, FILE_MAP_WRITE, 0, 0, sizeof(BackendParameters));
4626 : if (!param)
4627 : {
4628 : elog(LOG, "could not map backend parameter memory: error code %lu",
4629 : GetLastError());
4630 : CloseHandle(paramHandle);
4631 : return -1;
4632 : }
4633 :
4634 : /* Insert temp file name after --fork argument */
4635 : #ifdef _WIN64
4636 : sprintf(paramHandleStr, "%llu", (LONG_PTR) paramHandle);
4637 : #else
4638 : sprintf(paramHandleStr, "%lu", (DWORD) paramHandle);
4639 : #endif
4640 : argv[2] = paramHandleStr;
4641 :
4642 : /* Format the cmd line */
4643 : cmdLine[sizeof(cmdLine) - 1] = '\0';
4644 : cmdLine[sizeof(cmdLine) - 2] = '\0';
4645 : snprintf(cmdLine, sizeof(cmdLine) - 1, "\"%s\"", postgres_exec_path);
4646 : i = 0;
4647 : while (argv[++i] != NULL)
4648 : {
4649 : j = strlen(cmdLine);
4650 : snprintf(cmdLine + j, sizeof(cmdLine) - 1 - j, " \"%s\"", argv[i]);
4651 : }
4652 : if (cmdLine[sizeof(cmdLine) - 2] != '\0')
4653 : {
4654 : elog(LOG, "subprocess command line too long");
4655 : return -1;
4656 : }
4657 :
4658 : memset(&pi, 0, sizeof(pi));
4659 : memset(&si, 0, sizeof(si));
4660 : si.cb = sizeof(si);
4661 :
4662 : /*
4663 : * Create the subprocess in a suspended state. This will be resumed later,
4664 : * once we have written out the parameter file.
4665 : */
4666 : if (!CreateProcess(NULL, cmdLine, NULL, NULL, TRUE, CREATE_SUSPENDED,
4667 : NULL, NULL, &si, &pi))
4668 : {
4669 : elog(LOG, "CreateProcess call failed: %m (error code %lu)",
4670 : GetLastError());
4671 : return -1;
4672 : }
4673 :
4674 : if (!save_backend_variables(param, port, pi.hProcess, pi.dwProcessId))
4675 : {
4676 : /*
4677 : * log made by save_backend_variables, but we have to clean up the
4678 : * mess with the half-started process
4679 : */
4680 : if (!TerminateProcess(pi.hProcess, 255))
4681 : ereport(LOG,
4682 : (errmsg_internal("could not terminate unstarted process: error code %lu",
4683 : GetLastError())));
4684 : CloseHandle(pi.hProcess);
4685 : CloseHandle(pi.hThread);
4686 : return -1; /* log made by save_backend_variables */
4687 : }
4688 :
4689 : /* Drop the parameter shared memory that is now inherited to the backend */
4690 : if (!UnmapViewOfFile(param))
4691 : elog(LOG, "could not unmap view of backend parameter file: error code %lu",
4692 : GetLastError());
4693 : if (!CloseHandle(paramHandle))
4694 : elog(LOG, "could not close handle to backend parameter file: error code %lu",
4695 : GetLastError());
4696 :
4697 : /*
4698 : * Reserve the memory region used by our main shared memory segment before
4699 : * we resume the child process. Normally this should succeed, but if ASLR
4700 : * is active then it might sometimes fail due to the stack or heap having
4701 : * gotten mapped into that range. In that case, just terminate the
4702 : * process and retry.
4703 : */
4704 : if (!pgwin32_ReserveSharedMemoryRegion(pi.hProcess))
4705 : {
4706 : /* pgwin32_ReserveSharedMemoryRegion already made a log entry */
4707 : if (!TerminateProcess(pi.hProcess, 255))
4708 : ereport(LOG,
4709 : (errmsg_internal("could not terminate process that failed to reserve memory: error code %lu",
4710 : GetLastError())));
4711 : CloseHandle(pi.hProcess);
4712 : CloseHandle(pi.hThread);
4713 : if (++retry_count < 100)
4714 : goto retry;
4715 : ereport(LOG,
4716 : (errmsg("giving up after too many tries to reserve shared memory"),
4717 : errhint("This might be caused by ASLR or antivirus software.")));
4718 : return -1;
4719 : }
4720 :
4721 : /*
4722 : * Now that the backend variables are written out, we start the child
4723 : * thread so it can start initializing while we set up the rest of the
4724 : * parent state.
4725 : */
4726 : if (ResumeThread(pi.hThread) == -1)
4727 : {
4728 : if (!TerminateProcess(pi.hProcess, 255))
4729 : {
4730 : ereport(LOG,
4731 : (errmsg_internal("could not terminate unstartable process: error code %lu",
4732 : GetLastError())));
4733 : CloseHandle(pi.hProcess);
4734 : CloseHandle(pi.hThread);
4735 : return -1;
4736 : }
4737 : CloseHandle(pi.hProcess);
4738 : CloseHandle(pi.hThread);
4739 : ereport(LOG,
4740 : (errmsg_internal("could not resume thread of unstarted process: error code %lu",
4741 : GetLastError())));
4742 : return -1;
4743 : }
4744 :
4745 : /*
4746 : * Queue a waiter to signal when this child dies. The wait will be handled
4747 : * automatically by an operating system thread pool.
4748 : *
4749 : * Note: use malloc instead of palloc, since it needs to be thread-safe.
4750 : * Struct will be free():d from the callback function that runs on a
4751 : * different thread.
4752 : */
4753 : childinfo = malloc(sizeof(win32_deadchild_waitinfo));
4754 : if (!childinfo)
4755 : ereport(FATAL,
4756 : (errcode(ERRCODE_OUT_OF_MEMORY),
4757 : errmsg("out of memory")));
4758 :
4759 : childinfo->procHandle = pi.hProcess;
4760 : childinfo->procId = pi.dwProcessId;
4761 :
4762 : if (!RegisterWaitForSingleObject(&childinfo->waitHandle,
4763 : pi.hProcess,
4764 : pgwin32_deadchild_callback,
4765 : childinfo,
4766 : INFINITE,
4767 : WT_EXECUTEONLYONCE | WT_EXECUTEINWAITTHREAD))
4768 : ereport(FATAL,
4769 : (errmsg_internal("could not register process for wait: error code %lu",
4770 : GetLastError())));
4771 :
4772 : /* Don't close pi.hProcess here - the wait thread needs access to it */
4773 :
4774 : CloseHandle(pi.hThread);
4775 :
4776 : return pi.dwProcessId;
4777 : }
4778 : #endif /* WIN32 */
4779 :
4780 :
4781 : /*
4782 : * SubPostmasterMain -- Get the fork/exec'd process into a state equivalent
4783 : * to what it would be if we'd simply forked on Unix, and then
4784 : * dispatch to the appropriate place.
4785 : *
4786 : * The first two command line arguments are expected to be "--forkFOO"
4787 : * (where FOO indicates which postmaster child we are to become), and
4788 : * the name of a variables file that we can read to load data that would
4789 : * have been inherited by fork() on Unix. Remaining arguments go to the
4790 : * subprocess FooMain() routine.
4791 : */
4792 : void
4793 : SubPostmasterMain(int argc, char *argv[])
4794 : {
4795 : Port port;
4796 :
4797 : /* In EXEC_BACKEND case we will not have inherited these settings */
4798 : IsPostmasterEnvironment = true;
4799 : whereToSendOutput = DestNone;
4800 :
4801 : /* Setup as postmaster child */
4802 : InitPostmasterChild();
4803 :
4804 : /* Setup essential subsystems (to ensure elog() behaves sanely) */
4805 : InitializeGUCOptions();
4806 :
4807 : /* Check we got appropriate args */
4808 : if (argc < 3)
4809 : elog(FATAL, "invalid subpostmaster invocation");
4810 :
4811 : /* Read in the variables file */
4812 : memset(&port, 0, sizeof(Port));
4813 : read_backend_variables(argv[2], &port);
4814 :
4815 : /* Close the postmaster's sockets (as soon as we know them) */
4816 : ClosePostmasterPorts(strcmp(argv[1], "--forklog") == 0);
4817 :
4818 : /*
4819 : * Set reference point for stack-depth checking
4820 : */
4821 : set_stack_base();
4822 :
4823 : /*
4824 : * Set up memory area for GSS information. Mirrors the code in ConnCreate
4825 : * for the non-exec case.
4826 : */
4827 : #if defined(ENABLE_GSS) || defined(ENABLE_SSPI)
4828 : port.gss = (pg_gssinfo *) calloc(1, sizeof(pg_gssinfo));
4829 : if (!port.gss)
4830 : ereport(FATAL,
4831 : (errcode(ERRCODE_OUT_OF_MEMORY),
4832 : errmsg("out of memory")));
4833 : #endif
4834 :
4835 : /*
4836 : * If appropriate, physically re-attach to shared memory segment. We want
4837 : * to do this before going any further to ensure that we can attach at the
4838 : * same address the postmaster used. On the other hand, if we choose not
4839 : * to re-attach, we may have other cleanup to do.
4840 : *
4841 : * If testing EXEC_BACKEND on Linux, you should run this as root before
4842 : * starting the postmaster:
4843 : *
4844 : * echo 0 >/proc/sys/kernel/randomize_va_space
4845 : *
4846 : * This prevents using randomized stack and code addresses that cause the
4847 : * child process's memory map to be different from the parent's, making it
4848 : * sometimes impossible to attach to shared memory at the desired address.
4849 : * Return the setting to its old value (usually '1' or '2') when finished.
4850 : */
4851 : if (strcmp(argv[1], "--forkbackend") == 0 ||
4852 : strcmp(argv[1], "--forkavlauncher") == 0 ||
4853 : strcmp(argv[1], "--forkavworker") == 0 ||
4854 : strcmp(argv[1], "--forkboot") == 0 ||
4855 : strncmp(argv[1], "--forkbgworker=", 15) == 0)
4856 : PGSharedMemoryReAttach();
4857 : else
4858 : PGSharedMemoryNoReAttach();
4859 :
4860 : /* autovacuum needs this set before calling InitProcess */
4861 : if (strcmp(argv[1], "--forkavlauncher") == 0)
4862 : AutovacuumLauncherIAm();
4863 : if (strcmp(argv[1], "--forkavworker") == 0)
4864 : AutovacuumWorkerIAm();
4865 :
4866 : /*
4867 : * Start our win32 signal implementation. This has to be done after we
4868 : * read the backend variables, because we need to pick up the signal pipe
4869 : * from the parent process.
4870 : */
4871 : #ifdef WIN32
4872 : pgwin32_signal_initialize();
4873 : #endif
4874 :
4875 : /* In EXEC_BACKEND case we will not have inherited these settings */
4876 : pqinitmask();
4877 : PG_SETMASK(&BlockSig);
4878 :
4879 : /* Read in remaining GUC variables */
4880 : read_nondefault_variables();
4881 :
4882 : /*
4883 : * Check that the data directory looks valid, which will also check the
4884 : * privileges on the data directory and update our umask and file/group
4885 : * variables for creating files later. Note: this should really be done
4886 : * before we create any files or directories.
4887 : */
4888 : checkDataDir();
4889 :
4890 : /*
4891 : * (re-)read control file, as it contains config. The postmaster will
4892 : * already have read this, but this process doesn't know about that.
4893 : */
4894 : LocalProcessControlFile(false);
4895 :
4896 : /*
4897 : * Reload any libraries that were preloaded by the postmaster. Since we
4898 : * exec'd this process, those libraries didn't come along with us; but we
4899 : * should load them into all child processes to be consistent with the
4900 : * non-EXEC_BACKEND behavior.
4901 : */
4902 : process_shared_preload_libraries();
4903 :
4904 : /* Run backend or appropriate child */
4905 : if (strcmp(argv[1], "--forkbackend") == 0)
4906 : {
4907 : Assert(argc == 3); /* shouldn't be any more args */
4908 :
4909 : /*
4910 : * Need to reinitialize the SSL library in the backend, since the
4911 : * context structures contain function pointers and cannot be passed
4912 : * through the parameter file.
4913 : *
4914 : * If for some reason reload fails (maybe the user installed broken
4915 : * key files), soldier on without SSL; that's better than all
4916 : * connections becoming impossible.
4917 : *
4918 : * XXX should we do this in all child processes? For the moment it's
4919 : * enough to do it in backend children.
4920 : */
4921 : #ifdef USE_SSL
4922 : if (EnableSSL)
4923 : {
4924 : if (secure_initialize(false) == 0)
4925 : LoadedSSL = true;
4926 : else
4927 : ereport(LOG,
4928 : (errmsg("SSL configuration could not be loaded in child process")));
4929 : }
4930 : #endif
4931 :
4932 : /*
4933 : * Perform additional initialization and collect startup packet.
4934 : *
4935 : * We want to do this before InitProcess() for a couple of reasons: 1.
4936 : * so that we aren't eating up a PGPROC slot while waiting on the
4937 : * client. 2. so that if InitProcess() fails due to being out of
4938 : * PGPROC slots, we have already initialized libpq and are able to
4939 : * report the error to the client.
4940 : */
4941 : BackendInitialize(&port);
4942 :
4943 : /* Restore basic shared memory pointers */
4944 : InitShmemAccess(UsedShmemSegAddr);
4945 :
4946 : /* Need a PGPROC to run CreateSharedMemoryAndSemaphores */
4947 : InitProcess();
4948 :
4949 : /* Attach process to shared data structures */
4950 : CreateSharedMemoryAndSemaphores(0);
4951 :
4952 : /* And run the backend */
4953 : BackendRun(&port); /* does not return */
4954 : }
4955 : if (strcmp(argv[1], "--forkboot") == 0)
4956 : {
4957 : /* Restore basic shared memory pointers */
4958 : InitShmemAccess(UsedShmemSegAddr);
4959 :
4960 : /* Need a PGPROC to run CreateSharedMemoryAndSemaphores */
4961 : InitAuxiliaryProcess();
4962 :
4963 : /* Attach process to shared data structures */
4964 : CreateSharedMemoryAndSemaphores(0);
4965 :
4966 : AuxiliaryProcessMain(argc - 2, argv + 2); /* does not return */
4967 : }
4968 : if (strcmp(argv[1], "--forkavlauncher") == 0)
4969 : {
4970 : /* Restore basic shared memory pointers */
4971 : InitShmemAccess(UsedShmemSegAddr);
4972 :
4973 : /* Need a PGPROC to run CreateSharedMemoryAndSemaphores */
4974 : InitProcess();
4975 :
4976 : /* Attach process to shared data structures */
4977 : CreateSharedMemoryAndSemaphores(0);
4978 :
4979 : AutoVacLauncherMain(argc - 2, argv + 2); /* does not return */
4980 : }
4981 : if (strcmp(argv[1], "--forkavworker") == 0)
4982 : {
4983 : /* Restore basic shared memory pointers */
4984 : InitShmemAccess(UsedShmemSegAddr);
4985 :
4986 : /* Need a PGPROC to run CreateSharedMemoryAndSemaphores */
4987 : InitProcess();
4988 :
4989 : /* Attach process to shared data structures */
4990 : CreateSharedMemoryAndSemaphores(0);
4991 :
4992 : AutoVacWorkerMain(argc - 2, argv + 2); /* does not return */
4993 : }
4994 : if (strncmp(argv[1], "--forkbgworker=", 15) == 0)
4995 : {
4996 : int shmem_slot;
4997 :
4998 : /* do this as early as possible; in particular, before InitProcess() */
4999 : IsBackgroundWorker = true;
5000 :
5001 : /* Restore basic shared memory pointers */
5002 : InitShmemAccess(UsedShmemSegAddr);
5003 :
5004 : /* Need a PGPROC to run CreateSharedMemoryAndSemaphores */
5005 : InitProcess();
5006 :
5007 : /* Attach process to shared data structures */
5008 : CreateSharedMemoryAndSemaphores(0);
5009 :
5010 : /* Fetch MyBgworkerEntry from shared memory */
5011 : shmem_slot = atoi(argv[1] + 15);
5012 : MyBgworkerEntry = BackgroundWorkerEntry(shmem_slot);
5013 :
5014 : StartBackgroundWorker();
5015 : }
5016 : if (strcmp(argv[1], "--forkarch") == 0)
5017 : {
5018 : /* Do not want to attach to shared memory */
5019 :
5020 : PgArchiverMain(argc, argv); /* does not return */
5021 : }
5022 : if (strcmp(argv[1], "--forkcol") == 0)
5023 : {
5024 : /* Do not want to attach to shared memory */
5025 :
5026 : PgstatCollectorMain(argc, argv); /* does not return */
5027 : }
5028 : if (strcmp(argv[1], "--forklog") == 0)
5029 : {
5030 : /* Do not want to attach to shared memory */
5031 :
5032 : SysLoggerMain(argc, argv); /* does not return */
5033 : }
5034 :
5035 : abort(); /* shouldn't get here */
5036 : }
5037 : #endif /* EXEC_BACKEND */
5038 :
5039 :
5040 : /*
5041 : * ExitPostmaster -- cleanup
5042 : *
5043 : * Do NOT call exit() directly --- always go through here!
5044 : */
5045 : static void
5046 568 : ExitPostmaster(int status)
5047 : {
5048 : #ifdef HAVE_PTHREAD_IS_THREADED_NP
5049 :
5050 : /*
5051 : * There is no known cause for a postmaster to become multithreaded after
5052 : * startup. Recheck to account for the possibility of unknown causes.
5053 : * This message uses LOG level, because an unclean shutdown at this point
5054 : * would usually not look much different from a clean shutdown.
5055 : */
5056 : if (pthread_is_threaded_np() != 0)
5057 : ereport(LOG,
5058 : (errcode(ERRCODE_INTERNAL_ERROR),
5059 : errmsg_internal("postmaster became multithreaded"),
5060 : errdetail("Please report this to <pgsql-bugs@lists.postgresql.org>.")));
5061 : #endif
5062 :
5063 : /* should cleanup shared memory and kill all backends */
5064 :
5065 : /*
5066 : * Not sure of the semantics here. When the Postmaster dies, should the
5067 : * backends all be killed? probably not.
5068 : *
5069 : * MUST -- vadim 05-10-1999
5070 : */
5071 :
5072 568 : proc_exit(status);
5073 : }
5074 :
5075 : /*
5076 : * sigusr1_handler - handle signal conditions from child processes
5077 : */
5078 : static void
5079 1850 : sigusr1_handler(SIGNAL_ARGS)
5080 : {
5081 1850 : int save_errno = errno;
5082 :
5083 1850 : PG_SETMASK(&BlockSig);
5084 :
5085 : /* Process background worker state change. */
5086 1850 : if (CheckPostmasterSignal(PMSIGNAL_BACKGROUND_WORKER_CHANGE))
5087 : {
5088 870 : BackgroundWorkerStateChange();
5089 870 : StartWorkerNeeded = true;
5090 : }
5091 :
5092 : /*
5093 : * RECOVERY_STARTED and BEGIN_HOT_STANDBY signals are ignored in
5094 : * unexpected states. If the startup process quickly starts up, completes
5095 : * recovery, exits, we might process the death of the startup process
5096 : * first. We don't want to go back to recovery in that case.
5097 : */
5098 1970 : if (CheckPostmasterSignal(PMSIGNAL_RECOVERY_STARTED) &&
5099 240 : pmState == PM_STARTUP && Shutdown == NoShutdown)
5100 : {
5101 : /* WAL redo has started. We're out of reinitialization. */
5102 120 : FatalError = false;
5103 : Assert(AbortStartTime == 0);
5104 :
5105 : /*
5106 : * Crank up the background tasks. It doesn't matter if this fails,
5107 : * we'll just try again later.
5108 : */
5109 : Assert(CheckpointerPID == 0);
5110 120 : CheckpointerPID = StartCheckpointer();
5111 : Assert(BgWriterPID == 0);
5112 120 : BgWriterPID = StartBackgroundWriter();
5113 :
5114 : /*
5115 : * Start the archiver if we're responsible for (re-)archiving received
5116 : * files.
5117 : */
5118 : Assert(PgArchPID == 0);
5119 120 : if (XLogArchivingAlways())
5120 0 : PgArchPID = pgarch_start();
5121 :
5122 : /*
5123 : * If we aren't planning to enter hot standby mode later, treat
5124 : * RECOVERY_STARTED as meaning we're out of startup, and report status
5125 : * accordingly.
5126 : */
5127 120 : if (!EnableHotStandby)
5128 : {
5129 0 : AddToDataDirLockFile(LOCK_FILE_LINE_PM_STATUS, PM_STATUS_STANDBY);
5130 : #ifdef USE_SYSTEMD
5131 : sd_notify(0, "READY=1");
5132 : #endif
5133 : }
5134 :
5135 120 : pmState = PM_RECOVERY;
5136 : }
5137 1970 : if (CheckPostmasterSignal(PMSIGNAL_BEGIN_HOT_STANDBY) &&
5138 240 : pmState == PM_RECOVERY && Shutdown == NoShutdown)
5139 : {
5140 : /*
5141 : * Likewise, start other special children as needed.
5142 : */
5143 : Assert(PgStatPID == 0);
5144 120 : PgStatPID = pgstat_start();
5145 :
5146 120 : ereport(LOG,
5147 : (errmsg("database system is ready to accept read only connections")));
5148 :
5149 : /* Report status */
5150 120 : AddToDataDirLockFile(LOCK_FILE_LINE_PM_STATUS, PM_STATUS_READY);
5151 : #ifdef USE_SYSTEMD
5152 : sd_notify(0, "READY=1");
5153 : #endif
5154 :
5155 120 : pmState = PM_HOT_STANDBY;
5156 : /* Some workers may be scheduled to start now */
5157 120 : StartWorkerNeeded = true;
5158 : }
5159 :
5160 1850 : if (StartWorkerNeeded || HaveCrashedWorker)
5161 998 : maybe_start_bgworkers();
5162 :
5163 1876 : if (CheckPostmasterSignal(PMSIGNAL_WAKEN_ARCHIVER) &&
5164 26 : PgArchPID != 0)
5165 : {
5166 : /*
5167 : * Send SIGUSR1 to archiver process, to wake it up and begin archiving
5168 : * next WAL file.
5169 : */
5170 22 : signal_child(PgArchPID, SIGUSR1);
5171 : }
5172 :
5173 : /* Tell syslogger to rotate logfile if requested */
5174 1850 : if (SysLoggerPID != 0)
5175 : {
5176 2 : if (CheckLogrotateSignal())
5177 : {
5178 2 : signal_child(SysLoggerPID, SIGUSR1);
5179 2 : RemoveLogrotateSignalFiles();
5180 : }
5181 0 : else if (CheckPostmasterSignal(PMSIGNAL_ROTATE_LOGFILE))
5182 : {
5183 0 : signal_child(SysLoggerPID, SIGUSR1);
5184 : }
5185 : }
5186 :
5187 1856 : if (CheckPostmasterSignal(PMSIGNAL_START_AUTOVAC_LAUNCHER) &&
5188 6 : Shutdown == NoShutdown)
5189 : {
5190 : /*
5191 : * Start one iteration of the autovacuum daemon, even if autovacuuming
5192 : * is nominally not enabled. This is so we can have an active defense
5193 : * against transaction ID wraparound. We set a flag for the main loop
5194 : * to do it rather than trying to do it here --- this is because the
5195 : * autovac process itself may send the signal, and we want to handle
5196 : * that by launching another iteration as soon as the current one
5197 : * completes.
5198 : */
5199 6 : start_autovac_launcher = true;
5200 : }
5201 :
5202 1910 : if (CheckPostmasterSignal(PMSIGNAL_START_AUTOVAC_WORKER) &&
5203 60 : Shutdown == NoShutdown)
5204 : {
5205 : /* The autovacuum launcher wants us to start a worker process. */
5206 60 : StartAutovacuumWorker();
5207 : }
5208 :
5209 1850 : if (CheckPostmasterSignal(PMSIGNAL_START_WALRECEIVER))
5210 : {
5211 : /* Startup Process wants us to start the walreceiver process. */
5212 : /* Start immediately if possible, else remember request for later. */
5213 208 : WalReceiverRequested = true;
5214 208 : MaybeStartWalReceiver();
5215 : }
5216 :
5217 : /*
5218 : * Try to advance postmaster's state machine, if a child requests it.
5219 : *
5220 : * Be careful about the order of this action relative to sigusr1_handler's
5221 : * other actions. Generally, this should be after other actions, in case
5222 : * they have effects PostmasterStateMachine would need to know about.
5223 : * However, we should do it before the CheckPromoteSignal step, which
5224 : * cannot have any (immediate) effect on the state machine, but does
5225 : * depend on what state we're in now.
5226 : */
5227 1850 : if (CheckPostmasterSignal(PMSIGNAL_ADVANCE_STATE_MACHINE))
5228 : {
5229 508 : PostmasterStateMachine();
5230 : }
5231 :
5232 2250 : if (StartupPID != 0 &&
5233 1176 : (pmState == PM_STARTUP || pmState == PM_RECOVERY ||
5234 782 : pmState == PM_HOT_STANDBY || pmState == PM_WAIT_READONLY) &&
5235 396 : CheckPromoteSignal())
5236 : {
5237 : /* Tell startup process to finish recovery */
5238 46 : signal_child(StartupPID, SIGUSR2);
5239 : }
5240 :
5241 1850 : PG_SETMASK(&UnBlockSig);
5242 :
5243 1850 : errno = save_errno;
5244 1850 : }
5245 :
5246 : /*
5247 : * SIGTERM or SIGQUIT while processing startup packet.
5248 : * Clean up and exit(1).
5249 : *
5250 : * XXX: possible future improvement: try to send a message indicating
5251 : * why we are disconnecting. Problem is to be sure we don't block while
5252 : * doing so, nor mess up SSL initialization. In practice, if the client
5253 : * has wedged here, it probably couldn't do anything with the message anyway.
5254 : */
5255 : static void
5256 2 : startup_die(SIGNAL_ARGS)
5257 : {
5258 2 : proc_exit(1);
5259 : }
5260 :
5261 : /*
5262 : * Dummy signal handler
5263 : *
5264 : * We use this for signals that we don't actually use in the postmaster,
5265 : * but we do use in backends. If we were to SIG_IGN such signals in the
5266 : * postmaster, then a newly started backend might drop a signal that arrives
5267 : * before it's able to reconfigure its signal processing. (See notes in
5268 : * tcop/postgres.c.)
5269 : */
5270 : static void
5271 0 : dummy_handler(SIGNAL_ARGS)
5272 : {
5273 0 : }
5274 :
5275 : /*
5276 : * Timeout while processing startup packet.
5277 : * As for startup_die(), we clean up and exit(1).
5278 : */
5279 : static void
5280 0 : StartupPacketTimeoutHandler(void)
5281 : {
5282 0 : proc_exit(1);
5283 : }
5284 :
5285 :
5286 : /*
5287 : * Generate a random cancel key.
5288 : */
5289 : static bool
5290 9210 : RandomCancelKey(int32 *cancel_key)
5291 : {
5292 9210 : return pg_strong_random(cancel_key, sizeof(int32));
5293 : }
5294 :
5295 : /*
5296 : * Count up number of child processes of specified types (dead_end children
5297 : * are always excluded).
5298 : */
5299 : static int
5300 10032 : CountChildren(int target)
5301 : {
5302 : dlist_iter iter;
5303 10032 : int cnt = 0;
5304 :
5305 31498 : dlist_foreach(iter, &BackendList)
5306 : {
5307 21466 : Backend *bp = dlist_container(Backend, elem, iter.cur);
5308 :
5309 21466 : if (bp->dead_end)
5310 0 : continue;
5311 :
5312 : /*
5313 : * Since target == BACKEND_TYPE_ALL is the most common case, we test
5314 : * it first and avoid touching shared memory for every child.
5315 : */
5316 21466 : if (target != BACKEND_TYPE_ALL)
5317 : {
5318 : /*
5319 : * Assign bkend_type for any recently announced WAL Sender
5320 : * processes.
5321 : */
5322 2924 : if (bp->bkend_type == BACKEND_TYPE_NORMAL &&
5323 640 : IsPostmasterChildWalSender(bp->child_slot))
5324 42 : bp->bkend_type = BACKEND_TYPE_WALSND;
5325 :
5326 2284 : if (!(target & bp->bkend_type))
5327 274 : continue;
5328 : }
5329 :
5330 21192 : cnt++;
5331 : }
5332 10032 : return cnt;
5333 : }
5334 :
5335 :
5336 : /*
5337 : * StartChildProcess -- start an auxiliary process for the postmaster
5338 : *
5339 : * "type" determines what kind of child will be started. All child types
5340 : * initially go to AuxiliaryProcessMain, which will handle common setup.
5341 : *
5342 : * Return value of StartChildProcess is subprocess' PID, or 0 if failed
5343 : * to start subprocess.
5344 : */
5345 : static pid_t
5346 2430 : StartChildProcess(AuxProcType type)
5347 : {
5348 : pid_t pid;
5349 : char *av[10];
5350 2430 : int ac = 0;
5351 : char typebuf[32];
5352 :
5353 : /*
5354 : * Set up command-line arguments for subprocess
5355 : */
5356 2430 : av[ac++] = "postgres";
5357 :
5358 : #ifdef EXEC_BACKEND
5359 : av[ac++] = "--forkboot";
5360 : av[ac++] = NULL; /* filled in by postmaster_forkexec */
5361 : #endif
5362 :
5363 2430 : snprintf(typebuf, sizeof(typebuf), "-x%d", type);
5364 2430 : av[ac++] = typebuf;
5365 :
5366 2430 : av[ac] = NULL;
5367 : Assert(ac < lengthof(av));
5368 :
5369 : #ifdef EXEC_BACKEND
5370 : pid = postmaster_forkexec(ac, av);
5371 : #else /* !EXEC_BACKEND */
5372 2430 : pid = fork_process();
5373 :
5374 4252 : if (pid == 0) /* child */
5375 : {
5376 1822 : InitPostmasterChild();
5377 :
5378 : /* Close the postmaster's sockets */
5379 1822 : ClosePostmasterPorts(false);
5380 :
5381 : /* Release postmaster's working memory context */
5382 1822 : MemoryContextSwitchTo(TopMemoryContext);
5383 1822 : MemoryContextDelete(PostmasterContext);
5384 1822 : PostmasterContext = NULL;
5385 :
5386 1822 : AuxiliaryProcessMain(ac, av);
5387 : ExitPostmaster(0);
5388 : }
5389 : #endif /* EXEC_BACKEND */
5390 :
5391 2430 : if (pid < 0)
5392 : {
5393 : /* in parent, fork failed */
5394 0 : int save_errno = errno;
5395 :
5396 0 : errno = save_errno;
5397 0 : switch (type)
5398 : {
5399 : case StartupProcess:
5400 0 : ereport(LOG,
5401 : (errmsg("could not fork startup process: %m")));
5402 0 : break;
5403 : case BgWriterProcess:
5404 0 : ereport(LOG,
5405 : (errmsg("could not fork background writer process: %m")));
5406 0 : break;
5407 : case CheckpointerProcess:
5408 0 : ereport(LOG,
5409 : (errmsg("could not fork checkpointer process: %m")));
5410 0 : break;
5411 : case WalWriterProcess:
5412 0 : ereport(LOG,
5413 : (errmsg("could not fork WAL writer process: %m")));
5414 0 : break;
5415 : case WalReceiverProcess:
5416 0 : ereport(LOG,
5417 : (errmsg("could not fork WAL receiver process: %m")));
5418 0 : break;
5419 : default:
5420 0 : ereport(LOG,
5421 : (errmsg("could not fork process: %m")));
5422 0 : break;
5423 : }
5424 :
5425 : /*
5426 : * fork failure is fatal during startup, but there's no need to choke
5427 : * immediately if starting other child types fails.
5428 : */
5429 0 : if (type == StartupProcess)
5430 0 : ExitPostmaster(1);
5431 0 : return 0;
5432 : }
5433 :
5434 : /*
5435 : * in parent, successful fork
5436 : */
5437 2430 : return pid;
5438 : }
5439 :
5440 : /*
5441 : * StartAutovacuumWorker
5442 : * Start an autovac worker process.
5443 : *
5444 : * This function is here because it enters the resulting PID into the
5445 : * postmaster's private backends list.
5446 : *
5447 : * NB -- this code very roughly matches BackendStartup.
5448 : */
5449 : static void
5450 60 : StartAutovacuumWorker(void)
5451 : {
5452 : Backend *bn;
5453 :
5454 : /*
5455 : * If not in condition to run a process, don't try, but handle it like a
5456 : * fork failure. This does not normally happen, since the signal is only
5457 : * supposed to be sent by autovacuum launcher when it's OK to do it, but
5458 : * we have to check to avoid race-condition problems during DB state
5459 : * changes.
5460 : */
5461 60 : if (canAcceptConnections() == CAC_OK)
5462 : {
5463 : /*
5464 : * Compute the cancel key that will be assigned to this session. We
5465 : * probably don't need cancel keys for autovac workers, but we'd
5466 : * better have something random in the field to prevent unfriendly
5467 : * people from sending cancels to them.
5468 : */
5469 60 : if (!RandomCancelKey(&MyCancelKey))
5470 : {
5471 0 : ereport(LOG,
5472 : (errcode(ERRCODE_INTERNAL_ERROR),
5473 : errmsg("could not generate random cancel key")));
5474 0 : return;
5475 : }
5476 :
5477 60 : bn = (Backend *) malloc(sizeof(Backend));
5478 60 : if (bn)
5479 : {
5480 60 : bn->cancel_key = MyCancelKey;
5481 :
5482 : /* Autovac workers are not dead_end and need a child slot */
5483 60 : bn->dead_end = false;
5484 60 : bn->child_slot = MyPMChildSlot = AssignPostmasterChildSlot();
5485 60 : bn->bgworker_notify = false;
5486 :
5487 60 : bn->pid = StartAutoVacWorker();
5488 60 : if (bn->pid > 0)
5489 : {
5490 60 : bn->bkend_type = BACKEND_TYPE_AUTOVAC;
5491 60 : dlist_push_head(&BackendList, &bn->elem);
5492 : #ifdef EXEC_BACKEND
5493 : ShmemBackendArrayAdd(bn);
5494 : #endif
5495 : /* all OK */
5496 60 : return;
5497 : }
5498 :
5499 : /*
5500 : * fork failed, fall through to report -- actual error message was
5501 : * logged by StartAutoVacWorker
5502 : */
5503 0 : (void) ReleasePostmasterChildSlot(bn->child_slot);
5504 0 : free(bn);
5505 : }
5506 : else
5507 0 : ereport(LOG,
5508 : (errcode(ERRCODE_OUT_OF_MEMORY),
5509 : errmsg("out of memory")));
5510 : }
5511 :
5512 : /*
5513 : * Report the failure to the launcher, if it's running. (If it's not, we
5514 : * might not even be connected to shared memory, so don't try to call
5515 : * AutoVacWorkerFailed.) Note that we also need to signal it so that it
5516 : * responds to the condition, but we don't do that here, instead waiting
5517 : * for ServerLoop to do it. This way we avoid a ping-pong signalling in
5518 : * quick succession between the autovac launcher and postmaster in case
5519 : * things get ugly.
5520 : */
5521 0 : if (AutoVacPID != 0)
5522 : {
5523 0 : AutoVacWorkerFailed();
5524 0 : avlauncher_needs_signal = true;
5525 : }
5526 : }
5527 :
5528 : /*
5529 : * MaybeStartWalReceiver
5530 : * Start the WAL receiver process, if not running and our state allows.
5531 : *
5532 : * Note: if WalReceiverPID is already nonzero, it might seem that we should
5533 : * clear WalReceiverRequested. However, there's a race condition if the
5534 : * walreceiver terminates and the startup process immediately requests a new
5535 : * one: it's quite possible to get the signal for the request before reaping
5536 : * the dead walreceiver process. Better to risk launching an extra
5537 : * walreceiver than to miss launching one we need. (The walreceiver code
5538 : * has logic to recognize that it should go away if not needed.)
5539 : */
5540 : static void
5541 360 : MaybeStartWalReceiver(void)
5542 : {
5543 584 : if (WalReceiverPID == 0 &&
5544 666 : (pmState == PM_STARTUP || pmState == PM_RECOVERY ||
5545 442 : pmState == PM_HOT_STANDBY || pmState == PM_WAIT_READONLY) &&
5546 204 : Shutdown == NoShutdown)
5547 : {
5548 204 : WalReceiverPID = StartWalReceiver();
5549 204 : if (WalReceiverPID != 0)
5550 204 : WalReceiverRequested = false;
5551 : /* else leave the flag set, so we'll try again later */
5552 : }
5553 360 : }
5554 :
5555 :
5556 : /*
5557 : * Create the opts file
5558 : */
5559 : static bool
5560 572 : CreateOptsFile(int argc, char *argv[], char *fullprogname)
5561 : {
5562 : FILE *fp;
5563 : int i;
5564 :
5565 : #define OPTS_FILE "postmaster.opts"
5566 :
5567 572 : if ((fp = fopen(OPTS_FILE, "w")) == NULL)
5568 : {
5569 0 : elog(LOG, "could not create file \"%s\": %m", OPTS_FILE);
5570 0 : return false;
5571 : }
5572 :
5573 572 : fprintf(fp, "%s", fullprogname);
5574 2876 : for (i = 1; i < argc; i++)
5575 2304 : fprintf(fp, " \"%s\"", argv[i]);
5576 572 : fputs("\n", fp);
5577 :
5578 572 : if (fclose(fp))
5579 : {
5580 0 : elog(LOG, "could not write file \"%s\": %m", OPTS_FILE);
5581 0 : return false;
5582 : }
5583 :
5584 572 : return true;
5585 : }
5586 :
5587 :
5588 : /*
5589 : * MaxLivePostmasterChildren
5590 : *
5591 : * This reports the number of entries needed in per-child-process arrays
5592 : * (the PMChildFlags array, and if EXEC_BACKEND the ShmemBackendArray).
5593 : * These arrays include regular backends, autovac workers, walsenders
5594 : * and background workers, but not special children nor dead_end children.
5595 : * This allows the arrays to have a fixed maximum size, to wit the same
5596 : * too-many-children limit enforced by canAcceptConnections(). The exact value
5597 : * isn't too critical as long as it's more than MaxBackends.
5598 : */
5599 : int
5600 14246 : MaxLivePostmasterChildren(void)
5601 : {
5602 28492 : return 2 * (MaxConnections + autovacuum_max_workers + 1 +
5603 14246 : max_wal_senders + max_worker_processes);
5604 : }
5605 :
5606 : /*
5607 : * Connect background worker to a database.
5608 : */
5609 : void
5610 364 : BackgroundWorkerInitializeConnection(const char *dbname, const char *username, uint32 flags)
5611 : {
5612 364 : BackgroundWorker *worker = MyBgworkerEntry;
5613 :
5614 : /* XXX is this the right errcode? */
5615 364 : if (!(worker->bgw_flags & BGWORKER_BACKEND_DATABASE_CONNECTION))
5616 0 : ereport(FATAL,
5617 : (errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
5618 : errmsg("database connection requirement not indicated during registration")));
5619 :
5620 364 : InitPostgres(dbname, InvalidOid, username, InvalidOid, NULL, (flags & BGWORKER_BYPASS_ALLOWCONN) != 0);
5621 :
5622 : /* it had better not gotten out of "init" mode yet */
5623 360 : if (!IsInitProcessingMode())
5624 0 : ereport(ERROR,
5625 : (errmsg("invalid processing mode in background worker")));
5626 360 : SetProcessingMode(NormalProcessing);
5627 360 : }
5628 :
5629 : /*
5630 : * Connect background worker to a database using OIDs.
5631 : */
5632 : void
5633 1762 : BackgroundWorkerInitializeConnectionByOid(Oid dboid, Oid useroid, uint32 flags)
5634 : {
5635 1762 : BackgroundWorker *worker = MyBgworkerEntry;
5636 :
5637 : /* XXX is this the right errcode? */
5638 1762 : if (!(worker->bgw_flags & BGWORKER_BACKEND_DATABASE_CONNECTION))
5639 0 : ereport(FATAL,
5640 : (errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
5641 : errmsg("database connection requirement not indicated during registration")));
5642 :
5643 1762 : InitPostgres(NULL, dboid, NULL, useroid, NULL, (flags & BGWORKER_BYPASS_ALLOWCONN) != 0);
5644 :
5645 : /* it had better not gotten out of "init" mode yet */
5646 1762 : if (!IsInitProcessingMode())
5647 0 : ereport(ERROR,
5648 : (errmsg("invalid processing mode in background worker")));
5649 1762 : SetProcessingMode(NormalProcessing);
5650 1762 : }
5651 :
5652 : /*
5653 : * Block/unblock signals in a background worker
5654 : */
5655 : void
5656 0 : BackgroundWorkerBlockSignals(void)
5657 : {
5658 0 : PG_SETMASK(&BlockSig);
5659 0 : }
5660 :
5661 : void
5662 2140 : BackgroundWorkerUnblockSignals(void)
5663 : {
5664 2140 : PG_SETMASK(&UnBlockSig);
5665 2140 : }
5666 :
5667 : #ifdef EXEC_BACKEND
5668 : static pid_t
5669 : bgworker_forkexec(int shmem_slot)
5670 : {
5671 : char *av[10];
5672 : int ac = 0;
5673 : char forkav[MAXPGPATH];
5674 :
5675 : snprintf(forkav, MAXPGPATH, "--forkbgworker=%d", shmem_slot);
5676 :
5677 : av[ac++] = "postgres";
5678 : av[ac++] = forkav;
5679 : av[ac++] = NULL; /* filled in by postmaster_forkexec */
5680 : av[ac] = NULL;
5681 :
5682 : Assert(ac < lengthof(av));
5683 :
5684 : return postmaster_forkexec(ac, av);
5685 : }
5686 : #endif
5687 :
5688 : /*
5689 : * Start a new bgworker.
5690 : * Starting time conditions must have been checked already.
5691 : *
5692 : * Returns true on success, false on failure.
5693 : * In either case, update the RegisteredBgWorker's state appropriately.
5694 : *
5695 : * This code is heavily based on autovacuum.c, q.v.
5696 : */
5697 : static bool
5698 2280 : do_start_bgworker(RegisteredBgWorker *rw)
5699 : {
5700 : pid_t worker_pid;
5701 :
5702 : Assert(rw->rw_pid == 0);
5703 :
5704 : /*
5705 : * Allocate and assign the Backend element. Note we must do this before
5706 : * forking, so that we can handle out of memory properly.
5707 : *
5708 : * Treat failure as though the worker had crashed. That way, the
5709 : * postmaster will wait a bit before attempting to start it again; if it
5710 : * tried again right away, most likely it'd find itself repeating the
5711 : * out-of-memory or fork failure condition.
5712 : */
5713 2280 : if (!assign_backendlist_entry(rw))
5714 : {
5715 0 : rw->rw_crashed_at = GetCurrentTimestamp();
5716 0 : return false;
5717 : }
5718 :
5719 2280 : ereport(DEBUG1,
5720 : (errmsg("starting background worker process \"%s\"",
5721 : rw->rw_worker.bgw_name)));
5722 :
5723 : #ifdef EXEC_BACKEND
5724 : switch ((worker_pid = bgworker_forkexec(rw->rw_shmem_slot)))
5725 : #else
5726 2280 : switch ((worker_pid = fork_process()))
5727 : #endif
5728 : {
5729 : case -1:
5730 : /* in postmaster, fork failed ... */
5731 0 : ereport(LOG,
5732 : (errmsg("could not fork worker process: %m")));
5733 : /* undo what assign_backendlist_entry did */
5734 0 : ReleasePostmasterChildSlot(rw->rw_child_slot);
5735 0 : rw->rw_child_slot = 0;
5736 0 : free(rw->rw_backend);
5737 0 : rw->rw_backend = NULL;
5738 : /* mark entry as crashed, so we'll try again later */
5739 0 : rw->rw_crashed_at = GetCurrentTimestamp();
5740 0 : break;
5741 :
5742 : #ifndef EXEC_BACKEND
5743 : case 0:
5744 : /* in postmaster child ... */
5745 2140 : InitPostmasterChild();
5746 :
5747 : /* Close the postmaster's sockets */
5748 2140 : ClosePostmasterPorts(false);
5749 :
5750 : /*
5751 : * Before blowing away PostmasterContext, save this bgworker's
5752 : * data where it can find it.
5753 : */
5754 2140 : MyBgworkerEntry = (BackgroundWorker *)
5755 2140 : MemoryContextAlloc(TopMemoryContext, sizeof(BackgroundWorker));
5756 2140 : memcpy(MyBgworkerEntry, &rw->rw_worker, sizeof(BackgroundWorker));
5757 :
5758 : /* Release postmaster's working memory context */
5759 2140 : MemoryContextSwitchTo(TopMemoryContext);
5760 2140 : MemoryContextDelete(PostmasterContext);
5761 2140 : PostmasterContext = NULL;
5762 :
5763 2140 : StartBackgroundWorker();
5764 :
5765 : exit(1); /* should not get here */
5766 : break;
5767 : #endif
5768 : default:
5769 : /* in postmaster, fork successful ... */
5770 2278 : rw->rw_pid = worker_pid;
5771 2278 : rw->rw_backend->pid = rw->rw_pid;
5772 2278 : ReportBackgroundWorkerPID(rw);
5773 : /* add new worker to lists of backends */
5774 2278 : dlist_push_head(&BackendList, &rw->rw_backend->elem);
5775 : #ifdef EXEC_BACKEND
5776 : ShmemBackendArrayAdd(rw->rw_backend);
5777 : #endif
5778 2278 : return true;
5779 : }
5780 :
5781 0 : return false;
5782 : }
5783 :
5784 : /*
5785 : * Does the current postmaster state require starting a worker with the
5786 : * specified start_time?
5787 : */
5788 : static bool
5789 2976 : bgworker_should_start_now(BgWorkerStartTime start_time)
5790 : {
5791 2976 : switch (pmState)
5792 : {
5793 : case PM_NO_CHILDREN:
5794 : case PM_WAIT_DEAD_END:
5795 : case PM_SHUTDOWN_2:
5796 : case PM_SHUTDOWN:
5797 : case PM_WAIT_BACKENDS:
5798 : case PM_WAIT_READONLY:
5799 : case PM_WAIT_BACKUP:
5800 0 : break;
5801 :
5802 : case PM_RUN:
5803 2280 : if (start_time == BgWorkerStart_RecoveryFinished)
5804 624 : return true;
5805 : /* fall through */
5806 :
5807 : case PM_HOT_STANDBY:
5808 1776 : if (start_time == BgWorkerStart_ConsistentState)
5809 1656 : return true;
5810 : /* fall through */
5811 :
5812 : case PM_RECOVERY:
5813 : case PM_STARTUP:
5814 : case PM_INIT:
5815 696 : if (start_time == BgWorkerStart_PostmasterStart)
5816 0 : return true;
5817 : /* fall through */
5818 :
5819 : }
5820 :
5821 696 : return false;
5822 : }
5823 :
5824 : /*
5825 : * Allocate the Backend struct for a connected background worker, but don't
5826 : * add it to the list of backends just yet.
5827 : *
5828 : * On failure, return false without changing any worker state.
5829 : *
5830 : * Some info from the Backend is copied into the passed rw.
5831 : */
5832 : static bool
5833 2280 : assign_backendlist_entry(RegisteredBgWorker *rw)
5834 : {
5835 : Backend *bn;
5836 :
5837 : /*
5838 : * Compute the cancel key that will be assigned to this session. We
5839 : * probably don't need cancel keys for background workers, but we'd better
5840 : * have something random in the field to prevent unfriendly people from
5841 : * sending cancels to them.
5842 : */
5843 2280 : if (!RandomCancelKey(&MyCancelKey))
5844 : {
5845 0 : ereport(LOG,
5846 : (errcode(ERRCODE_INTERNAL_ERROR),
5847 : errmsg("could not generate random cancel key")));
5848 0 : return false;
5849 : }
5850 :
5851 2280 : bn = malloc(sizeof(Backend));
5852 2280 : if (bn == NULL)
5853 : {
5854 0 : ereport(LOG,
5855 : (errcode(ERRCODE_OUT_OF_MEMORY),
5856 : errmsg("out of memory")));
5857 0 : return false;
5858 : }
5859 :
5860 2280 : bn->cancel_key = MyCancelKey;
5861 2280 : bn->child_slot = MyPMChildSlot = AssignPostmasterChildSlot();
5862 2280 : bn->bkend_type = BACKEND_TYPE_BGWORKER;
5863 2280 : bn->dead_end = false;
5864 2280 : bn->bgworker_notify = false;
5865 :
5866 2280 : rw->rw_backend = bn;
5867 2280 : rw->rw_child_slot = bn->child_slot;
5868 :
5869 2280 : return true;
5870 : }
5871 :
5872 : /*
5873 : * If the time is right, start background worker(s).
5874 : *
5875 : * As a side effect, the bgworker control variables are set or reset
5876 : * depending on whether more workers may need to be started.
5877 : *
5878 : * We limit the number of workers started per call, to avoid consuming the
5879 : * postmaster's attention for too long when many such requests are pending.
5880 : * As long as StartWorkerNeeded is true, ServerLoop will not block and will
5881 : * call this function again after dealing with any other issues.
5882 : */
5883 : static void
5884 5138 : maybe_start_bgworkers(void)
5885 : {
5886 : #define MAX_BGWORKERS_TO_LAUNCH 100
5887 5138 : int num_launched = 0;
5888 5138 : TimestampTz now = 0;
5889 : slist_mutable_iter iter;
5890 :
5891 : /*
5892 : * During crash recovery, we have no need to be called until the state
5893 : * transition out of recovery.
5894 : */
5895 5138 : if (FatalError)
5896 : {
5897 4 : StartWorkerNeeded = false;
5898 4 : HaveCrashedWorker = false;
5899 8 : return;
5900 : }
5901 :
5902 : /* Don't need to be called again unless we find a reason for it below */
5903 5134 : StartWorkerNeeded = false;
5904 5134 : HaveCrashedWorker = false;
5905 :
5906 14078 : slist_foreach_modify(iter, &BackgroundWorkerList)
5907 : {
5908 : RegisteredBgWorker *rw;
5909 :
5910 8946 : rw = slist_container(RegisteredBgWorker, rw_lnode, iter.cur);
5911 :
5912 : /* ignore if already running */
5913 8946 : if (rw->rw_pid != 0)
5914 4462 : continue;
5915 :
5916 : /* if marked for death, clean up and remove from list */
5917 4484 : if (rw->rw_terminate)
5918 : {
5919 0 : ForgetBackgroundWorker(&iter);
5920 0 : continue;
5921 : }
5922 :
5923 : /*
5924 : * If this worker has crashed previously, maybe it needs to be
5925 : * restarted (unless on registration it specified it doesn't want to
5926 : * be restarted at all). Check how long ago did a crash last happen.
5927 : * If the last crash is too recent, don't start it right away; let it
5928 : * be restarted once enough time has passed.
5929 : */
5930 4484 : if (rw->rw_crashed_at != 0)
5931 : {
5932 1508 : if (rw->rw_worker.bgw_restart_time == BGW_NEVER_RESTART)
5933 : {
5934 : int notify_pid;
5935 :
5936 0 : notify_pid = rw->rw_worker.bgw_notify_pid;
5937 :
5938 0 : ForgetBackgroundWorker(&iter);
5939 :
5940 : /* Report worker is gone now. */
5941 0 : if (notify_pid != 0)
5942 0 : kill(notify_pid, SIGUSR1);
5943 :
5944 0 : continue;
5945 : }
5946 :
5947 : /* read system time only when needed */
5948 1508 : if (now == 0)
5949 1508 : now = GetCurrentTimestamp();
5950 :
5951 1508 : if (!TimestampDifferenceExceeds(rw->rw_crashed_at, now,
5952 1508 : rw->rw_worker.bgw_restart_time * 1000))
5953 : {
5954 : /* Set flag to remember that we have workers to start later */
5955 1508 : HaveCrashedWorker = true;
5956 1508 : continue;
5957 : }
5958 : }
5959 :
5960 2976 : if (bgworker_should_start_now(rw->rw_worker.bgw_start_time))
5961 : {
5962 : /* reset crash time before trying to start worker */
5963 2280 : rw->rw_crashed_at = 0;
5964 :
5965 : /*
5966 : * Try to start the worker.
5967 : *
5968 : * On failure, give up processing workers for now, but set
5969 : * StartWorkerNeeded so we'll come back here on the next iteration
5970 : * of ServerLoop to try again. (We don't want to wait, because
5971 : * there might be additional ready-to-run workers.) We could set
5972 : * HaveCrashedWorker as well, since this worker is now marked
5973 : * crashed, but there's no need because the next run of this
5974 : * function will do that.
5975 : */
5976 2280 : if (!do_start_bgworker(rw))
5977 : {
5978 0 : StartWorkerNeeded = true;
5979 0 : return;
5980 : }
5981 :
5982 : /*
5983 : * If we've launched as many workers as allowed, quit, but have
5984 : * ServerLoop call us again to look for additional ready-to-run
5985 : * workers. There might not be any, but we'll find out the next
5986 : * time we run.
5987 : */
5988 2278 : if (++num_launched >= MAX_BGWORKERS_TO_LAUNCH)
5989 : {
5990 0 : StartWorkerNeeded = true;
5991 0 : return;
5992 : }
5993 : }
5994 : }
5995 : }
5996 :
5997 : /*
5998 : * When a backend asks to be notified about worker state changes, we
5999 : * set a flag in its backend entry. The background worker machinery needs
6000 : * to know when such backends exit.
6001 : */
6002 : bool
6003 1778 : PostmasterMarkPIDForWorkerNotify(int pid)
6004 : {
6005 : dlist_iter iter;
6006 : Backend *bp;
6007 :
6008 2876 : dlist_foreach(iter, &BackendList)
6009 : {
6010 2876 : bp = dlist_container(Backend, elem, iter.cur);
6011 2876 : if (bp->pid == pid)
6012 : {
6013 1778 : bp->bgworker_notify = true;
6014 1778 : return true;
6015 : }
6016 : }
6017 0 : return false;
6018 : }
6019 :
6020 : #ifdef EXEC_BACKEND
6021 :
6022 : /*
6023 : * The following need to be available to the save/restore_backend_variables
6024 : * functions. They are marked NON_EXEC_STATIC in their home modules.
6025 : */
6026 : extern slock_t *ShmemLock;
6027 : extern slock_t *ProcStructLock;
6028 : extern PGPROC *AuxiliaryProcs;
6029 : extern PMSignalData *PMSignalState;
6030 : extern pgsocket pgStatSock;
6031 : extern pg_time_t first_syslogger_file_time;
6032 :
6033 : #ifndef WIN32
6034 : #define write_inheritable_socket(dest, src, childpid) ((*(dest) = (src)), true)
6035 : #define read_inheritable_socket(dest, src) (*(dest) = *(src))
6036 : #else
6037 : static bool write_duplicated_handle(HANDLE *dest, HANDLE src, HANDLE child);
6038 : static bool write_inheritable_socket(InheritableSocket *dest, SOCKET src,
6039 : pid_t childPid);
6040 : static void read_inheritable_socket(SOCKET *dest, InheritableSocket *src);
6041 : #endif
6042 :
6043 :
6044 : /* Save critical backend variables into the BackendParameters struct */
6045 : #ifndef WIN32
6046 : static bool
6047 : save_backend_variables(BackendParameters *param, Port *port)
6048 : #else
6049 : static bool
6050 : save_backend_variables(BackendParameters *param, Port *port,
6051 : HANDLE childProcess, pid_t childPid)
6052 : #endif
6053 : {
6054 : memcpy(¶m->port, port, sizeof(Port));
6055 : if (!write_inheritable_socket(¶m->portsocket, port->sock, childPid))
6056 : return false;
6057 :
6058 : strlcpy(param->DataDir, DataDir, MAXPGPATH);
6059 :
6060 : memcpy(¶m->ListenSocket, &ListenSocket, sizeof(ListenSocket));
6061 :
6062 : param->MyCancelKey = MyCancelKey;
6063 : param->MyPMChildSlot = MyPMChildSlot;
6064 :
6065 : #ifdef WIN32
6066 : param->ShmemProtectiveRegion = ShmemProtectiveRegion;
6067 : #endif
6068 : param->UsedShmemSegID = UsedShmemSegID;
6069 : param->UsedShmemSegAddr = UsedShmemSegAddr;
6070 :
6071 : param->ShmemLock = ShmemLock;
6072 : param->ShmemVariableCache = ShmemVariableCache;
6073 : param->ShmemBackendArray = ShmemBackendArray;
6074 :
6075 : #ifndef HAVE_SPINLOCKS
6076 : param->SpinlockSemaArray = SpinlockSemaArray;
6077 : #endif
6078 : param->NamedLWLockTrancheRequests = NamedLWLockTrancheRequests;
6079 : param->NamedLWLockTrancheArray = NamedLWLockTrancheArray;
6080 : param->MainLWLockArray = MainLWLockArray;
6081 : param->ProcStructLock = ProcStructLock;
6082 : param->ProcGlobal = ProcGlobal;
6083 : param->AuxiliaryProcs = AuxiliaryProcs;
6084 : param->PreparedXactProcs = PreparedXactProcs;
6085 : param->PMSignalState = PMSignalState;
6086 : if (!write_inheritable_socket(¶m->pgStatSock, pgStatSock, childPid))
6087 : return false;
6088 :
6089 : param->PostmasterPid = PostmasterPid;
6090 : param->PgStartTime = PgStartTime;
6091 : param->PgReloadTime = PgReloadTime;
6092 : param->first_syslogger_file_time = first_syslogger_file_time;
6093 :
6094 : param->redirection_done = redirection_done;
6095 : param->IsBinaryUpgrade = IsBinaryUpgrade;
6096 : param->max_safe_fds = max_safe_fds;
6097 :
6098 : param->MaxBackends = MaxBackends;
6099 :
6100 : #ifdef WIN32
6101 : param->PostmasterHandle = PostmasterHandle;
6102 : if (!write_duplicated_handle(¶m->initial_signal_pipe,
6103 : pgwin32_create_signal_listener(childPid),
6104 : childProcess))
6105 : return false;
6106 : #else
6107 : memcpy(¶m->postmaster_alive_fds, &postmaster_alive_fds,
6108 : sizeof(postmaster_alive_fds));
6109 : #endif
6110 :
6111 : memcpy(¶m->syslogPipe, &syslogPipe, sizeof(syslogPipe));
6112 :
6113 : strlcpy(param->my_exec_path, my_exec_path, MAXPGPATH);
6114 :
6115 : strlcpy(param->pkglib_path, pkglib_path, MAXPGPATH);
6116 :
6117 : strlcpy(param->ExtraOptions, ExtraOptions, MAXPGPATH);
6118 :
6119 : return true;
6120 : }
6121 :
6122 :
6123 : #ifdef WIN32
6124 : /*
6125 : * Duplicate a handle for usage in a child process, and write the child
6126 : * process instance of the handle to the parameter file.
6127 : */
6128 : static bool
6129 : write_duplicated_handle(HANDLE *dest, HANDLE src, HANDLE childProcess)
6130 : {
6131 : HANDLE hChild = INVALID_HANDLE_VALUE;
6132 :
6133 : if (!DuplicateHandle(GetCurrentProcess(),
6134 : src,
6135 : childProcess,
6136 : &hChild,
6137 : 0,
6138 : TRUE,
6139 : DUPLICATE_CLOSE_SOURCE | DUPLICATE_SAME_ACCESS))
6140 : {
6141 : ereport(LOG,
6142 : (errmsg_internal("could not duplicate handle to be written to backend parameter file: error code %lu",
6143 : GetLastError())));
6144 : return false;
6145 : }
6146 :
6147 : *dest = hChild;
6148 : return true;
6149 : }
6150 :
6151 : /*
6152 : * Duplicate a socket for usage in a child process, and write the resulting
6153 : * structure to the parameter file.
6154 : * This is required because a number of LSPs (Layered Service Providers) very
6155 : * common on Windows (antivirus, firewalls, download managers etc) break
6156 : * straight socket inheritance.
6157 : */
6158 : static bool
6159 : write_inheritable_socket(InheritableSocket *dest, SOCKET src, pid_t childpid)
6160 : {
6161 : dest->origsocket = src;
6162 : if (src != 0 && src != PGINVALID_SOCKET)
6163 : {
6164 : /* Actual socket */
6165 : if (WSADuplicateSocket(src, childpid, &dest->wsainfo) != 0)
6166 : {
6167 : ereport(LOG,
6168 : (errmsg("could not duplicate socket %d for use in backend: error code %d",
6169 : (int) src, WSAGetLastError())));
6170 : return false;
6171 : }
6172 : }
6173 : return true;
6174 : }
6175 :
6176 : /*
6177 : * Read a duplicate socket structure back, and get the socket descriptor.
6178 : */
6179 : static void
6180 : read_inheritable_socket(SOCKET *dest, InheritableSocket *src)
6181 : {
6182 : SOCKET s;
6183 :
6184 : if (src->origsocket == PGINVALID_SOCKET || src->origsocket == 0)
6185 : {
6186 : /* Not a real socket! */
6187 : *dest = src->origsocket;
6188 : }
6189 : else
6190 : {
6191 : /* Actual socket, so create from structure */
6192 : s = WSASocket(FROM_PROTOCOL_INFO,
6193 : FROM_PROTOCOL_INFO,
6194 : FROM_PROTOCOL_INFO,
6195 : &src->wsainfo,
6196 : 0,
6197 : 0);
6198 : if (s == INVALID_SOCKET)
6199 : {
6200 : write_stderr("could not create inherited socket: error code %d\n",
6201 : WSAGetLastError());
6202 : exit(1);
6203 : }
6204 : *dest = s;
6205 :
6206 : /*
6207 : * To make sure we don't get two references to the same socket, close
6208 : * the original one. (This would happen when inheritance actually
6209 : * works..
6210 : */
6211 : closesocket(src->origsocket);
6212 : }
6213 : }
6214 : #endif
6215 :
6216 : static void
6217 : read_backend_variables(char *id, Port *port)
6218 : {
6219 : BackendParameters param;
6220 :
6221 : #ifndef WIN32
6222 : /* Non-win32 implementation reads from file */
6223 : FILE *fp;
6224 :
6225 : /* Open file */
6226 : fp = AllocateFile(id, PG_BINARY_R);
6227 : if (!fp)
6228 : {
6229 : write_stderr("could not open backend variables file \"%s\": %s\n",
6230 : id, strerror(errno));
6231 : exit(1);
6232 : }
6233 :
6234 : if (fread(¶m, sizeof(param), 1, fp) != 1)
6235 : {
6236 : write_stderr("could not read from backend variables file \"%s\": %s\n",
6237 : id, strerror(errno));
6238 : exit(1);
6239 : }
6240 :
6241 : /* Release file */
6242 : FreeFile(fp);
6243 : if (unlink(id) != 0)
6244 : {
6245 : write_stderr("could not remove file \"%s\": %s\n",
6246 : id, strerror(errno));
6247 : exit(1);
6248 : }
6249 : #else
6250 : /* Win32 version uses mapped file */
6251 : HANDLE paramHandle;
6252 : BackendParameters *paramp;
6253 :
6254 : #ifdef _WIN64
6255 : paramHandle = (HANDLE) _atoi64(id);
6256 : #else
6257 : paramHandle = (HANDLE) atol(id);
6258 : #endif
6259 : paramp = MapViewOfFile(paramHandle, FILE_MAP_READ, 0, 0, 0);
6260 : if (!paramp)
6261 : {
6262 : write_stderr("could not map view of backend variables: error code %lu\n",
6263 : GetLastError());
6264 : exit(1);
6265 : }
6266 :
6267 : memcpy(¶m, paramp, sizeof(BackendParameters));
6268 :
6269 : if (!UnmapViewOfFile(paramp))
6270 : {
6271 : write_stderr("could not unmap view of backend variables: error code %lu\n",
6272 : GetLastError());
6273 : exit(1);
6274 : }
6275 :
6276 : if (!CloseHandle(paramHandle))
6277 : {
6278 : write_stderr("could not close handle to backend parameter variables: error code %lu\n",
6279 : GetLastError());
6280 : exit(1);
6281 : }
6282 : #endif
6283 :
6284 : restore_backend_variables(¶m, port);
6285 : }
6286 :
6287 : /* Restore critical backend variables from the BackendParameters struct */
6288 : static void
6289 : restore_backend_variables(BackendParameters *param, Port *port)
6290 : {
6291 : memcpy(port, ¶m->port, sizeof(Port));
6292 : read_inheritable_socket(&port->sock, ¶m->portsocket);
6293 :
6294 : SetDataDir(param->DataDir);
6295 :
6296 : memcpy(&ListenSocket, ¶m->ListenSocket, sizeof(ListenSocket));
6297 :
6298 : MyCancelKey = param->MyCancelKey;
6299 : MyPMChildSlot = param->MyPMChildSlot;
6300 :
6301 : #ifdef WIN32
6302 : ShmemProtectiveRegion = param->ShmemProtectiveRegion;
6303 : #endif
6304 : UsedShmemSegID = param->UsedShmemSegID;
6305 : UsedShmemSegAddr = param->UsedShmemSegAddr;
6306 :
6307 : ShmemLock = param->ShmemLock;
6308 : ShmemVariableCache = param->ShmemVariableCache;
6309 : ShmemBackendArray = param->ShmemBackendArray;
6310 :
6311 : #ifndef HAVE_SPINLOCKS
6312 : SpinlockSemaArray = param->SpinlockSemaArray;
6313 : #endif
6314 : NamedLWLockTrancheRequests = param->NamedLWLockTrancheRequests;
6315 : NamedLWLockTrancheArray = param->NamedLWLockTrancheArray;
6316 : MainLWLockArray = param->MainLWLockArray;
6317 : ProcStructLock = param->ProcStructLock;
6318 : ProcGlobal = param->ProcGlobal;
6319 : AuxiliaryProcs = param->AuxiliaryProcs;
6320 : PreparedXactProcs = param->PreparedXactProcs;
6321 : PMSignalState = param->PMSignalState;
6322 : read_inheritable_socket(&pgStatSock, ¶m->pgStatSock);
6323 :
6324 : PostmasterPid = param->PostmasterPid;
6325 : PgStartTime = param->PgStartTime;
6326 : PgReloadTime = param->PgReloadTime;
6327 : first_syslogger_file_time = param->first_syslogger_file_time;
6328 :
6329 : redirection_done = param->redirection_done;
6330 : IsBinaryUpgrade = param->IsBinaryUpgrade;
6331 : max_safe_fds = param->max_safe_fds;
6332 :
6333 : MaxBackends = param->MaxBackends;
6334 :
6335 : #ifdef WIN32
6336 : PostmasterHandle = param->PostmasterHandle;
6337 : pgwin32_initial_signal_pipe = param->initial_signal_pipe;
6338 : #else
6339 : memcpy(&postmaster_alive_fds, ¶m->postmaster_alive_fds,
6340 : sizeof(postmaster_alive_fds));
6341 : #endif
6342 :
6343 : memcpy(&syslogPipe, ¶m->syslogPipe, sizeof(syslogPipe));
6344 :
6345 : strlcpy(my_exec_path, param->my_exec_path, MAXPGPATH);
6346 :
6347 : strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH);
6348 :
6349 : strlcpy(ExtraOptions, param->ExtraOptions, MAXPGPATH);
6350 : }
6351 :
6352 :
6353 : Size
6354 : ShmemBackendArraySize(void)
6355 : {
6356 : return mul_size(MaxLivePostmasterChildren(), sizeof(Backend));
6357 : }
6358 :
6359 : void
6360 : ShmemBackendArrayAllocation(void)
6361 : {
6362 : Size size = ShmemBackendArraySize();
6363 :
6364 : ShmemBackendArray = (Backend *) ShmemAlloc(size);
6365 : /* Mark all slots as empty */
6366 : memset(ShmemBackendArray, 0, size);
6367 : }
6368 :
6369 : static void
6370 : ShmemBackendArrayAdd(Backend *bn)
6371 : {
6372 : /* The array slot corresponding to my PMChildSlot should be free */
6373 : int i = bn->child_slot - 1;
6374 :
6375 : Assert(ShmemBackendArray[i].pid == 0);
6376 : ShmemBackendArray[i] = *bn;
6377 : }
6378 :
6379 : static void
6380 : ShmemBackendArrayRemove(Backend *bn)
6381 : {
6382 : int i = bn->child_slot - 1;
6383 :
6384 : Assert(ShmemBackendArray[i].pid == bn->pid);
6385 : /* Mark the slot as empty */
6386 : ShmemBackendArray[i].pid = 0;
6387 : }
6388 : #endif /* EXEC_BACKEND */
6389 :
6390 :
6391 : #ifdef WIN32
6392 :
6393 : /*
6394 : * Subset implementation of waitpid() for Windows. We assume pid is -1
6395 : * (that is, check all child processes) and options is WNOHANG (don't wait).
6396 : */
6397 : static pid_t
6398 : waitpid(pid_t pid, int *exitstatus, int options)
6399 : {
6400 : DWORD dwd;
6401 : ULONG_PTR key;
6402 : OVERLAPPED *ovl;
6403 :
6404 : /*
6405 : * Check if there are any dead children. If there are, return the pid of
6406 : * the first one that died.
6407 : */
6408 : if (GetQueuedCompletionStatus(win32ChildQueue, &dwd, &key, &ovl, 0))
6409 : {
6410 : *exitstatus = (int) key;
6411 : return dwd;
6412 : }
6413 :
6414 : return -1;
6415 : }
6416 :
6417 : /*
6418 : * Note! Code below executes on a thread pool! All operations must
6419 : * be thread safe! Note that elog() and friends must *not* be used.
6420 : */
6421 : static void WINAPI
6422 : pgwin32_deadchild_callback(PVOID lpParameter, BOOLEAN TimerOrWaitFired)
6423 : {
6424 : win32_deadchild_waitinfo *childinfo = (win32_deadchild_waitinfo *) lpParameter;
6425 : DWORD exitcode;
6426 :
6427 : if (TimerOrWaitFired)
6428 : return; /* timeout. Should never happen, since we use
6429 : * INFINITE as timeout value. */
6430 :
6431 : /*
6432 : * Remove handle from wait - required even though it's set to wait only
6433 : * once
6434 : */
6435 : UnregisterWaitEx(childinfo->waitHandle, NULL);
6436 :
6437 : if (!GetExitCodeProcess(childinfo->procHandle, &exitcode))
6438 : {
6439 : /*
6440 : * Should never happen. Inform user and set a fixed exitcode.
6441 : */
6442 : write_stderr("could not read exit code for process\n");
6443 : exitcode = 255;
6444 : }
6445 :
6446 : if (!PostQueuedCompletionStatus(win32ChildQueue, childinfo->procId, (ULONG_PTR) exitcode, NULL))
6447 : write_stderr("could not post child completion status\n");
6448 :
6449 : /*
6450 : * Handle is per-process, so we close it here instead of in the
6451 : * originating thread
6452 : */
6453 : CloseHandle(childinfo->procHandle);
6454 :
6455 : /*
6456 : * Free struct that was allocated before the call to
6457 : * RegisterWaitForSingleObject()
6458 : */
6459 : free(childinfo);
6460 :
6461 : /* Queue SIGCHLD signal */
6462 : pg_queue_signal(SIGCHLD);
6463 : }
6464 : #endif /* WIN32 */
6465 :
6466 : /*
6467 : * Initialize one and only handle for monitoring postmaster death.
6468 : *
6469 : * Called once in the postmaster, so that child processes can subsequently
6470 : * monitor if their parent is dead.
6471 : */
6472 : static void
6473 572 : InitPostmasterDeathWatchHandle(void)
6474 : {
6475 : #ifndef WIN32
6476 :
6477 : /*
6478 : * Create a pipe. Postmaster holds the write end of the pipe open
6479 : * (POSTMASTER_FD_OWN), and children hold the read end. Children can pass
6480 : * the read file descriptor to select() to wake up in case postmaster
6481 : * dies, or check for postmaster death with a (read() == 0). Children must
6482 : * close the write end as soon as possible after forking, because EOF
6483 : * won't be signaled in the read end until all processes have closed the
6484 : * write fd. That is taken care of in ClosePostmasterPorts().
6485 : */
6486 : Assert(MyProcPid == PostmasterPid);
6487 572 : if (pipe(postmaster_alive_fds) < 0)
6488 0 : ereport(FATAL,
6489 : (errcode_for_file_access(),
6490 : errmsg_internal("could not create pipe to monitor postmaster death: %m")));
6491 :
6492 : /*
6493 : * Set O_NONBLOCK to allow testing for the fd's presence with a read()
6494 : * call.
6495 : */
6496 572 : if (fcntl(postmaster_alive_fds[POSTMASTER_FD_WATCH], F_SETFL, O_NONBLOCK) == -1)
6497 0 : ereport(FATAL,
6498 : (errcode_for_socket_access(),
6499 : errmsg_internal("could not set postmaster death monitoring pipe to nonblocking mode: %m")));
6500 : #else
6501 :
6502 : /*
6503 : * On Windows, we use a process handle for the same purpose.
6504 : */
6505 : if (DuplicateHandle(GetCurrentProcess(),
6506 : GetCurrentProcess(),
6507 : GetCurrentProcess(),
6508 : &PostmasterHandle,
6509 : 0,
6510 : TRUE,
6511 : DUPLICATE_SAME_ACCESS) == 0)
6512 : ereport(FATAL,
6513 : (errmsg_internal("could not duplicate postmaster handle: error code %lu",
6514 : GetLastError())));
6515 : #endif /* WIN32 */
6516 572 : }
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