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syncrep.h File Reference
#include "access/xlogdefs.h"
#include "utils/guc.h"
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Data Structures

struct  SyncRepConfigData
 

Macros

#define SyncRepRequested()   (max_wal_senders > 0 && synchronous_commit > SYNCHRONOUS_COMMIT_LOCAL_FLUSH)
 
#define SYNC_REP_NO_WAIT   (-1)
 
#define SYNC_REP_WAIT_WRITE   0
 
#define SYNC_REP_WAIT_FLUSH   1
 
#define SYNC_REP_WAIT_APPLY   2
 
#define NUM_SYNC_REP_WAIT_MODE   3
 
#define SYNC_REP_NOT_WAITING   0
 
#define SYNC_REP_WAITING   1
 
#define SYNC_REP_WAIT_COMPLETE   2
 
#define SYNC_REP_PRIORITY   0
 
#define SYNC_REP_QUORUM   1
 

Typedefs

typedef struct SyncRepConfigData SyncRepConfigData
 

Functions

void SyncRepWaitForLSN (XLogRecPtr lsn, bool commit)
 
void SyncRepCleanupAtProcExit (void)
 
void SyncRepInitConfig (void)
 
void SyncRepReleaseWaiters (void)
 
ListSyncRepGetSyncStandbys (bool *am_sync)
 
void SyncRepUpdateSyncStandbysDefined (void)
 
bool check_synchronous_standby_names (char **newval, void **extra, GucSource source)
 
void assign_synchronous_standby_names (const char *newval, void *extra)
 
void assign_synchronous_commit (int newval, void *extra)
 
int syncrep_yyparse (void)
 
int syncrep_yylex (void)
 
void syncrep_yyerror (const char *str)
 
void syncrep_scanner_init (const char *query_string)
 
void syncrep_scanner_finish (void)
 

Variables

SyncRepConfigDataSyncRepConfig
 
SyncRepConfigDatasyncrep_parse_result
 
char * syncrep_parse_error_msg
 
char * SyncRepStandbyNames
 

Macro Definition Documentation

◆ NUM_SYNC_REP_WAIT_MODE

#define NUM_SYNC_REP_WAIT_MODE   3

◆ SYNC_REP_NO_WAIT

#define SYNC_REP_NO_WAIT   (-1)

Definition at line 23 of file syncrep.h.

Referenced by assign_synchronous_commit().

◆ SYNC_REP_NOT_WAITING

#define SYNC_REP_NOT_WAITING   0

Definition at line 31 of file syncrep.h.

Referenced by InitProcess(), SyncRepCancelWait(), and SyncRepWaitForLSN().

◆ SYNC_REP_PRIORITY

◆ SYNC_REP_QUORUM

#define SYNC_REP_QUORUM   1

Definition at line 37 of file syncrep.h.

Referenced by SyncRepGetSyncStandbysQuorum().

◆ SYNC_REP_WAIT_APPLY

#define SYNC_REP_WAIT_APPLY   2

◆ SYNC_REP_WAIT_COMPLETE

#define SYNC_REP_WAIT_COMPLETE   2

Definition at line 33 of file syncrep.h.

Referenced by SyncRepWaitForLSN(), and SyncRepWakeQueue().

◆ SYNC_REP_WAIT_FLUSH

#define SYNC_REP_WAIT_FLUSH   1

◆ SYNC_REP_WAIT_WRITE

#define SYNC_REP_WAIT_WRITE   0

◆ SYNC_REP_WAITING

#define SYNC_REP_WAITING   1

Definition at line 32 of file syncrep.h.

Referenced by SyncRepWaitForLSN().

◆ SyncRepRequested

#define SyncRepRequested ( )    (max_wal_senders > 0 && synchronous_commit > SYNCHRONOUS_COMMIT_LOCAL_FLUSH)

Definition at line 19 of file syncrep.h.

Referenced by SyncRepWaitForLSN().

Typedef Documentation

◆ SyncRepConfigData

Function Documentation

◆ assign_synchronous_commit()

void assign_synchronous_commit ( int  newval,
void *  extra 
)

Definition at line 1203 of file syncrep.c.

References SYNC_REP_NO_WAIT, SYNC_REP_WAIT_APPLY, SYNC_REP_WAIT_FLUSH, SYNC_REP_WAIT_WRITE, SYNCHRONOUS_COMMIT_REMOTE_APPLY, SYNCHRONOUS_COMMIT_REMOTE_FLUSH, SYNCHRONOUS_COMMIT_REMOTE_WRITE, and SyncRepWaitMode.

1204 {
1205  switch (newval)
1206  {
1209  break;
1212  break;
1215  break;
1216  default:
1218  break;
1219  }
1220 }
#define SYNC_REP_NO_WAIT
Definition: syncrep.h:23
#define SYNC_REP_WAIT_APPLY
Definition: syncrep.h:26
#define SYNC_REP_WAIT_FLUSH
Definition: syncrep.h:25
#define newval
static int SyncRepWaitMode
Definition: syncrep.c:98
#define SYNC_REP_WAIT_WRITE
Definition: syncrep.h:24

◆ assign_synchronous_standby_names()

void assign_synchronous_standby_names ( const char *  newval,
void *  extra 
)

Definition at line 1197 of file syncrep.c.

1198 {
1199  SyncRepConfig = (SyncRepConfigData *) extra;
1200 }
SyncRepConfigData * SyncRepConfig
Definition: syncrep.c:97

◆ check_synchronous_standby_names()

bool check_synchronous_standby_names ( char **  newval,
void **  extra,
GucSource  source 
)

Definition at line 1140 of file syncrep.c.

References SyncRepConfigData::config_size, GUC_check_errcode(), GUC_check_errdetail, GUC_check_errmsg, malloc, SyncRepConfigData::num_sync, syncrep_parse_error_msg, syncrep_parse_result, syncrep_scanner_finish(), syncrep_scanner_init(), and syncrep_yyparse().

1141 {
1142  if (*newval != NULL && (*newval)[0] != '\0')
1143  {
1144  int parse_rc;
1145  SyncRepConfigData *pconf;
1146 
1147  /* Reset communication variables to ensure a fresh start */
1148  syncrep_parse_result = NULL;
1149  syncrep_parse_error_msg = NULL;
1150 
1151  /* Parse the synchronous_standby_names string */
1153  parse_rc = syncrep_yyparse();
1155 
1156  if (parse_rc != 0 || syncrep_parse_result == NULL)
1157  {
1158  GUC_check_errcode(ERRCODE_SYNTAX_ERROR);
1161  else
1162  GUC_check_errdetail("synchronous_standby_names parser failed");
1163  return false;
1164  }
1165 
1166  if (syncrep_parse_result->num_sync <= 0)
1167  {
1168  GUC_check_errmsg("number of synchronous standbys (%d) must be greater than zero",
1170  return false;
1171  }
1172 
1173  /* GUC extra value must be malloc'd, not palloc'd */
1174  pconf = (SyncRepConfigData *)
1176  if (pconf == NULL)
1177  return false;
1179 
1180  *extra = (void *) pconf;
1181 
1182  /*
1183  * We need not explicitly clean up syncrep_parse_result. It, and any
1184  * other cruft generated during parsing, will be freed when the
1185  * current memory context is deleted. (This code is generally run in
1186  * a short-lived context used for config file processing, so that will
1187  * not be very long.)
1188  */
1189  }
1190  else
1191  *extra = NULL;
1192 
1193  return true;
1194 }
void syncrep_scanner_finish(void)
void syncrep_scanner_init(const char *query_string)
#define GUC_check_errdetail
Definition: guc.h:409
char * syncrep_parse_error_msg
#define GUC_check_errmsg
Definition: guc.h:405
void GUC_check_errcode(int sqlerrcode)
Definition: guc.c:9796
#define malloc(a)
Definition: header.h:50
SyncRepConfigData * syncrep_parse_result
#define newval
int syncrep_yyparse(void)

◆ syncrep_scanner_finish()

void syncrep_scanner_finish ( void  )

◆ syncrep_scanner_init()

void syncrep_scanner_init ( const char *  query_string)

◆ syncrep_yyerror()

void syncrep_yyerror ( const char *  str)

◆ syncrep_yylex()

int syncrep_yylex ( void  )

◆ syncrep_yyparse()

int syncrep_yyparse ( void  )

◆ SyncRepCleanupAtProcExit()

void SyncRepCleanupAtProcExit ( void  )

Definition at line 363 of file syncrep.c.

References LW_EXCLUSIVE, LWLockAcquire(), LWLockRelease(), MyProc, SHMQueueDelete(), SHMQueueIsDetached(), and PGPROC::syncRepLinks.

Referenced by ProcKill().

364 {
366  {
367  LWLockAcquire(SyncRepLock, LW_EXCLUSIVE);
369  LWLockRelease(SyncRepLock);
370  }
371 }
PGPROC * MyProc
Definition: proc.c:67
void LWLockRelease(LWLock *lock)
Definition: lwlock.c:1722
bool SHMQueueIsDetached(const SHM_QUEUE *queue)
Definition: shmqueue.c:47
bool LWLockAcquire(LWLock *lock, LWLockMode mode)
Definition: lwlock.c:1118
SHM_QUEUE syncRepLinks
Definition: proc.h:150
void SHMQueueDelete(SHM_QUEUE *queue)
Definition: shmqueue.c:68

◆ SyncRepGetSyncStandbys()

List* SyncRepGetSyncStandbys ( bool am_sync)

Definition at line 680 of file syncrep.c.

References NIL, SYNC_REP_PRIORITY, SyncRepConfigData::syncrep_method, SyncRepGetSyncStandbysPriority(), and SyncRepGetSyncStandbysQuorum().

Referenced by pg_stat_get_wal_senders(), and SyncRepGetSyncRecPtr().

681 {
682  /* Set default result */
683  if (am_sync != NULL)
684  *am_sync = false;
685 
686  /* Quick exit if sync replication is not requested */
687  if (SyncRepConfig == NULL)
688  return NIL;
689 
693 }
#define NIL
Definition: pg_list.h:69
static List * SyncRepGetSyncStandbysPriority(bool *am_sync)
Definition: syncrep.c:771
#define SYNC_REP_PRIORITY
Definition: syncrep.h:36
uint8 syncrep_method
Definition: syncrep.h:51
SyncRepConfigData * SyncRepConfig
Definition: syncrep.c:97
static List * SyncRepGetSyncStandbysQuorum(bool *am_sync)
Definition: syncrep.c:706

◆ SyncRepInitConfig()

void SyncRepInitConfig ( void  )

Definition at line 384 of file syncrep.c.

References application_name, DEBUG1, ereport, errmsg(), LW_EXCLUSIVE, LWLockAcquire(), LWLockRelease(), MyWalSnd, WalSnd::sync_standby_priority, and SyncRepGetStandbyPriority().

Referenced by StartLogicalReplication(), StartReplication(), WalSndLoop(), WalSndWaitForWal(), and WalSndWriteData().

385 {
386  int priority;
387 
388  /*
389  * Determine if we are a potential sync standby and remember the result
390  * for handling replies from standby.
391  */
392  priority = SyncRepGetStandbyPriority();
393  if (MyWalSnd->sync_standby_priority != priority)
394  {
395  LWLockAcquire(SyncRepLock, LW_EXCLUSIVE);
396  MyWalSnd->sync_standby_priority = priority;
397  LWLockRelease(SyncRepLock);
398  ereport(DEBUG1,
399  (errmsg("standby \"%s\" now has synchronous standby priority %u",
400  application_name, priority)));
401  }
402 }
#define DEBUG1
Definition: elog.h:25
void LWLockRelease(LWLock *lock)
Definition: lwlock.c:1722
#define ereport(elevel, rest)
Definition: elog.h:122
WalSnd * MyWalSnd
Definition: walsender.c:111
int sync_standby_priority
bool LWLockAcquire(LWLock *lock, LWLockMode mode)
Definition: lwlock.c:1118
char * application_name
Definition: guc.c:470
int errmsg(const char *fmt,...)
Definition: elog.c:797
static int SyncRepGetStandbyPriority(void)
Definition: syncrep.c:949

◆ SyncRepReleaseWaiters()

void SyncRepReleaseWaiters ( void  )

Definition at line 412 of file syncrep.c.

References announce_next_takeover, application_name, DEBUG3, elog, ereport, errmsg(), WalSnd::flush, LOG, WalSndCtlData::lsn, LW_EXCLUSIVE, LWLockAcquire(), LWLockRelease(), MyWalSnd, WalSnd::state, SYNC_REP_PRIORITY, SYNC_REP_WAIT_APPLY, SYNC_REP_WAIT_FLUSH, SYNC_REP_WAIT_WRITE, WalSnd::sync_standby_priority, SyncRepConfigData::syncrep_method, SyncRepGetSyncRecPtr(), SyncRepWakeQueue(), WalSndCtl, WALSNDSTATE_STREAMING, and XLogRecPtrIsInvalid.

Referenced by ProcessStandbyReplyMessage().

413 {
414  volatile WalSndCtlData *walsndctl = WalSndCtl;
415  XLogRecPtr writePtr;
416  XLogRecPtr flushPtr;
417  XLogRecPtr applyPtr;
418  bool got_recptr;
419  bool am_sync;
420  int numwrite = 0;
421  int numflush = 0;
422  int numapply = 0;
423 
424  /*
425  * If this WALSender is serving a standby that is not on the list of
426  * potential sync standbys then we have nothing to do. If we are still
427  * starting up, still running base backup or the current flush position is
428  * still invalid, then leave quickly also.
429  */
430  if (MyWalSnd->sync_standby_priority == 0 ||
433  {
434  announce_next_takeover = true;
435  return;
436  }
437 
438  /*
439  * We're a potential sync standby. Release waiters if there are enough
440  * sync standbys and we are considered as sync.
441  */
442  LWLockAcquire(SyncRepLock, LW_EXCLUSIVE);
443 
444  /*
445  * Check whether we are a sync standby or not, and calculate the synced
446  * positions among all sync standbys.
447  */
448  got_recptr = SyncRepGetSyncRecPtr(&writePtr, &flushPtr, &applyPtr, &am_sync);
449 
450  /*
451  * If we are managing a sync standby, though we weren't prior to this,
452  * then announce we are now a sync standby.
453  */
454  if (announce_next_takeover && am_sync)
455  {
456  announce_next_takeover = false;
457 
459  ereport(LOG,
460  (errmsg("standby \"%s\" is now a synchronous standby with priority %u",
462  else
463  ereport(LOG,
464  (errmsg("standby \"%s\" is now a candidate for quorum synchronous standby",
465  application_name)));
466  }
467 
468  /*
469  * If the number of sync standbys is less than requested or we aren't
470  * managing a sync standby then just leave.
471  */
472  if (!got_recptr || !am_sync)
473  {
474  LWLockRelease(SyncRepLock);
475  announce_next_takeover = !am_sync;
476  return;
477  }
478 
479  /*
480  * Set the lsn first so that when we wake backends they will release up to
481  * this location.
482  */
483  if (walsndctl->lsn[SYNC_REP_WAIT_WRITE] < writePtr)
484  {
485  walsndctl->lsn[SYNC_REP_WAIT_WRITE] = writePtr;
486  numwrite = SyncRepWakeQueue(false, SYNC_REP_WAIT_WRITE);
487  }
488  if (walsndctl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr)
489  {
490  walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr;
491  numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH);
492  }
493  if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr)
494  {
495  walsndctl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr;
496  numapply = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY);
497  }
498 
499  LWLockRelease(SyncRepLock);
500 
501  elog(DEBUG3, "released %d procs up to write %X/%X, %d procs up to flush %X/%X, %d procs up to apply %X/%X",
502  numwrite, (uint32) (writePtr >> 32), (uint32) writePtr,
503  numflush, (uint32) (flushPtr >> 32), (uint32) flushPtr,
504  numapply, (uint32) (applyPtr >> 32), (uint32) applyPtr);
505 }
static bool SyncRepGetSyncRecPtr(XLogRecPtr *writePtr, XLogRecPtr *flushPtr, XLogRecPtr *applyPtr, bool *am_sync)
Definition: syncrep.c:518
#define DEBUG3
Definition: elog.h:23
#define SYNC_REP_PRIORITY
Definition: syncrep.h:36
uint8 syncrep_method
Definition: syncrep.h:51
WalSndCtlData * WalSndCtl
Definition: walsender.c:108
#define LOG
Definition: elog.h:26
SyncRepConfigData * SyncRepConfig
Definition: syncrep.c:97
static int SyncRepWakeQueue(bool all, int mode)
Definition: syncrep.c:996
void LWLockRelease(LWLock *lock)
Definition: lwlock.c:1722
XLogRecPtr flush
#define SYNC_REP_WAIT_APPLY
Definition: syncrep.h:26
static bool announce_next_takeover
Definition: syncrep.c:95
WalSndState state
unsigned int uint32
Definition: c.h:296
#define ereport(elevel, rest)
Definition: elog.h:122
#define SYNC_REP_WAIT_FLUSH
Definition: syncrep.h:25
#define XLogRecPtrIsInvalid(r)
Definition: xlogdefs.h:29
WalSnd * MyWalSnd
Definition: walsender.c:111
uint64 XLogRecPtr
Definition: xlogdefs.h:21
int sync_standby_priority
bool LWLockAcquire(LWLock *lock, LWLockMode mode)
Definition: lwlock.c:1118
XLogRecPtr lsn[NUM_SYNC_REP_WAIT_MODE]
char * application_name
Definition: guc.c:470
int errmsg(const char *fmt,...)
Definition: elog.c:797
#define elog
Definition: elog.h:219
#define SYNC_REP_WAIT_WRITE
Definition: syncrep.h:24

◆ SyncRepUpdateSyncStandbysDefined()

void SyncRepUpdateSyncStandbysDefined ( void  )

Definition at line 1064 of file syncrep.c.

References Assert, i, LW_EXCLUSIVE, LWLockAcquire(), LWLockRelease(), NUM_SYNC_REP_WAIT_MODE, offsetof, SHMQueueNext(), WalSndCtlData::sync_standbys_defined, PGPROC::syncRepLinks, WalSndCtlData::SyncRepQueue, SyncRepWakeQueue(), SyncStandbysDefined, PGPROC::waitLSN, and WalSndCtl.

Referenced by UpdateSharedMemoryConfig().

1065 {
1066  bool sync_standbys_defined = SyncStandbysDefined();
1067 
1068  if (sync_standbys_defined != WalSndCtl->sync_standbys_defined)
1069  {
1070  LWLockAcquire(SyncRepLock, LW_EXCLUSIVE);
1071 
1072  /*
1073  * If synchronous_standby_names has been reset to empty, it's futile
1074  * for backends to continue to waiting. Since the user no longer
1075  * wants synchronous replication, we'd better wake them up.
1076  */
1077  if (!sync_standbys_defined)
1078  {
1079  int i;
1080 
1081  for (i = 0; i < NUM_SYNC_REP_WAIT_MODE; i++)
1082  SyncRepWakeQueue(true, i);
1083  }
1084 
1085  /*
1086  * Only allow people to join the queue when there are synchronous
1087  * standbys defined. Without this interlock, there's a race
1088  * condition: we might wake up all the current waiters; then, some
1089  * backend that hasn't yet reloaded its config might go to sleep on
1090  * the queue (and never wake up). This prevents that.
1091  */
1092  WalSndCtl->sync_standbys_defined = sync_standbys_defined;
1093 
1094  LWLockRelease(SyncRepLock);
1095  }
1096 }
WalSndCtlData * WalSndCtl
Definition: walsender.c:108
static int SyncRepWakeQueue(bool all, int mode)
Definition: syncrep.c:996
void LWLockRelease(LWLock *lock)
Definition: lwlock.c:1722
#define SyncStandbysDefined()
Definition: syncrep.c:92
bool LWLockAcquire(LWLock *lock, LWLockMode mode)
Definition: lwlock.c:1118
int i
#define NUM_SYNC_REP_WAIT_MODE
Definition: syncrep.h:28

◆ SyncRepWaitForLSN()

void SyncRepWaitForLSN ( XLogRecPtr  lsn,
bool  commit 
)

Definition at line 146 of file syncrep.c.

References Assert, DestNone, ereport, errcode(), errdetail(), errmsg(), get_ps_display(), LW_EXCLUSIVE, LWLockAcquire(), LWLockRelease(), Min, MyLatch, MyProc, palloc(), pfree(), pg_read_barrier, PostmasterIsAlive(), ProcDiePending, QueryCancelPending, ResetLatch(), set_ps_display(), SHMQueueIsDetached(), SYNC_REP_NOT_WAITING, SYNC_REP_WAIT_COMPLETE, SYNC_REP_WAIT_FLUSH, SYNC_REP_WAITING, WalSndCtlData::sync_standbys_defined, SyncRepCancelWait(), PGPROC::syncRepLinks, SyncRepQueueInsert(), SyncRepRequested, PGPROC::syncRepState, SyncRepWaitMode, SyncStandbysDefined, update_process_title, WAIT_EVENT_SYNC_REP, WaitLatch(), PGPROC::waitLSN, WalSndCtl, WARNING, whereToSendOutput, WL_LATCH_SET, and WL_POSTMASTER_DEATH.

Referenced by EndPrepare(), RecordTransactionAbortPrepared(), RecordTransactionCommit(), and RecordTransactionCommitPrepared().

147 {
148  char *new_status = NULL;
149  const char *old_status;
150  int mode;
151 
152  /* Cap the level for anything other than commit to remote flush only. */
153  if (commit)
154  mode = SyncRepWaitMode;
155  else
157 
158  /*
159  * Fast exit if user has not requested sync replication, or there are no
160  * sync replication standby names defined. Note that those standbys don't
161  * need to be connected.
162  */
164  return;
165 
167  Assert(WalSndCtl != NULL);
168 
169  LWLockAcquire(SyncRepLock, LW_EXCLUSIVE);
171 
172  /*
173  * We don't wait for sync rep if WalSndCtl->sync_standbys_defined is not
174  * set. See SyncRepUpdateSyncStandbysDefined.
175  *
176  * Also check that the standby hasn't already replied. Unlikely race
177  * condition but we'll be fetching that cache line anyway so it's likely
178  * to be a low cost check.
179  */
181  lsn <= WalSndCtl->lsn[mode])
182  {
183  LWLockRelease(SyncRepLock);
184  return;
185  }
186 
187  /*
188  * Set our waitLSN so WALSender will know when to wake us, and add
189  * ourselves to the queue.
190  */
191  MyProc->waitLSN = lsn;
193  SyncRepQueueInsert(mode);
194  Assert(SyncRepQueueIsOrderedByLSN(mode));
195  LWLockRelease(SyncRepLock);
196 
197  /* Alter ps display to show waiting for sync rep. */
199  {
200  int len;
201 
202  old_status = get_ps_display(&len);
203  new_status = (char *) palloc(len + 32 + 1);
204  memcpy(new_status, old_status, len);
205  sprintf(new_status + len, " waiting for %X/%X",
206  (uint32) (lsn >> 32), (uint32) lsn);
207  set_ps_display(new_status, false);
208  new_status[len] = '\0'; /* truncate off " waiting ..." */
209  }
210 
211  /*
212  * Wait for specified LSN to be confirmed.
213  *
214  * Each proc has its own wait latch, so we perform a normal latch
215  * check/wait loop here.
216  */
217  for (;;)
218  {
219  /* Must reset the latch before testing state. */
221 
222  /*
223  * Acquiring the lock is not needed, the latch ensures proper
224  * barriers. If it looks like we're done, we must really be done,
225  * because once walsender changes the state to SYNC_REP_WAIT_COMPLETE,
226  * it will never update it again, so we can't be seeing a stale value
227  * in that case.
228  */
230  break;
231 
232  /*
233  * If a wait for synchronous replication is pending, we can neither
234  * acknowledge the commit nor raise ERROR or FATAL. The latter would
235  * lead the client to believe that the transaction aborted, which is
236  * not true: it's already committed locally. The former is no good
237  * either: the client has requested synchronous replication, and is
238  * entitled to assume that an acknowledged commit is also replicated,
239  * which might not be true. So in this case we issue a WARNING (which
240  * some clients may be able to interpret) and shut off further output.
241  * We do NOT reset ProcDiePending, so that the process will die after
242  * the commit is cleaned up.
243  */
244  if (ProcDiePending)
245  {
247  (errcode(ERRCODE_ADMIN_SHUTDOWN),
248  errmsg("canceling the wait for synchronous replication and terminating connection due to administrator command"),
249  errdetail("The transaction has already committed locally, but might not have been replicated to the standby.")));
252  break;
253  }
254 
255  /*
256  * It's unclear what to do if a query cancel interrupt arrives. We
257  * can't actually abort at this point, but ignoring the interrupt
258  * altogether is not helpful, so we just terminate the wait with a
259  * suitable warning.
260  */
261  if (QueryCancelPending)
262  {
263  QueryCancelPending = false;
265  (errmsg("canceling wait for synchronous replication due to user request"),
266  errdetail("The transaction has already committed locally, but might not have been replicated to the standby.")));
268  break;
269  }
270 
271  /*
272  * If the postmaster dies, we'll probably never get an
273  * acknowledgement, because all the wal sender processes will exit. So
274  * just bail out.
275  */
276  if (!PostmasterIsAlive())
277  {
278  ProcDiePending = true;
281  break;
282  }
283 
284  /*
285  * Wait on latch. Any condition that should wake us up will set the
286  * latch, so no need for timeout.
287  */
290  }
291 
292  /*
293  * WalSender has checked our LSN and has removed us from queue. Clean up
294  * state and leave. It's OK to reset these shared memory fields without
295  * holding SyncRepLock, because any walsenders will ignore us anyway when
296  * we're not on the queue. We need a read barrier to make sure we see the
297  * changes to the queue link (this might be unnecessary without
298  * assertions, but better safe than sorry).
299  */
300  pg_read_barrier();
303  MyProc->waitLSN = 0;
304 
305  if (new_status)
306  {
307  /* Reset ps display */
308  set_ps_display(new_status, false);
309  pfree(new_status);
310  }
311 }
static void SyncRepCancelWait(void)
Definition: syncrep.c:353
bool update_process_title
Definition: ps_status.c:35
static void SyncRepQueueInsert(int mode)
Definition: syncrep.c:320
PGPROC * MyProc
Definition: proc.c:67
#define SYNC_REP_WAITING
Definition: syncrep.h:32
#define Min(x, y)
Definition: c.h:802
void set_ps_display(const char *activity, bool force)
Definition: ps_status.c:326
#define SYNC_REP_NOT_WAITING
Definition: syncrep.h:31
WalSndCtlData * WalSndCtl
Definition: walsender.c:108
int errcode(int sqlerrcode)
Definition: elog.c:575
void ResetLatch(volatile Latch *latch)
Definition: latch.c:497
volatile bool QueryCancelPending
Definition: globals.c:30
void LWLockRelease(LWLock *lock)
Definition: lwlock.c:1722
int WaitLatch(volatile Latch *latch, int wakeEvents, long timeout, uint32 wait_event_info)
Definition: latch.c:336
void pfree(void *pointer)
Definition: mcxt.c:949
Definition: dest.h:88
const char * get_ps_display(int *displen)
Definition: ps_status.c:405
#define SyncStandbysDefined()
Definition: syncrep.c:92
bool PostmasterIsAlive(void)
Definition: pmsignal.c:272
int errdetail(const char *fmt,...)
Definition: elog.c:873
unsigned int uint32
Definition: c.h:296
#define ereport(elevel, rest)
Definition: elog.h:122
#define SYNC_REP_WAIT_FLUSH
Definition: syncrep.h:25
#define SyncRepRequested()
Definition: syncrep.h:19
#define WARNING
Definition: elog.h:40
#define WL_POSTMASTER_DEATH
Definition: latch.h:128
#define SYNC_REP_WAIT_COMPLETE
Definition: syncrep.h:33
#define Assert(condition)
Definition: c.h:670
#define pg_read_barrier()
Definition: atomics.h:161
bool SHMQueueIsDetached(const SHM_QUEUE *queue)
Definition: shmqueue.c:47
bool LWLockAcquire(LWLock *lock, LWLockMode mode)
Definition: lwlock.c:1118
SHM_QUEUE syncRepLinks
Definition: proc.h:150
volatile bool ProcDiePending
Definition: globals.c:31
void * palloc(Size size)
Definition: mcxt.c:848
int errmsg(const char *fmt,...)
Definition: elog.c:797
struct Latch * MyLatch
Definition: globals.c:52
int syncRepState
Definition: proc.h:149
CommandDest whereToSendOutput
Definition: postgres.c:88
static int SyncRepWaitMode
Definition: syncrep.c:98
#define WL_LATCH_SET
Definition: latch.h:124
XLogRecPtr waitLSN
Definition: proc.h:148

Variable Documentation

◆ syncrep_parse_error_msg

char* syncrep_parse_error_msg

◆ syncrep_parse_result

SyncRepConfigData* syncrep_parse_result

◆ SyncRepConfig

SyncRepConfigData* SyncRepConfig

Definition at line 97 of file syncrep.c.

Referenced by pg_stat_get_wal_senders().

◆ SyncRepStandbyNames

char* SyncRepStandbyNames

Definition at line 90 of file syncrep.c.