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

struct  SyncRepStandbyData
 
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
 
#define YY_TYPEDEF_YY_SCANNER_T
 

Typedefs

typedef struct SyncRepStandbyData SyncRepStandbyData
 
typedef struct SyncRepConfigData SyncRepConfigData
 
typedef void * yyscan_t
 

Functions

void SyncRepWaitForLSN (XLogRecPtr lsn, bool commit)
 
void SyncRepCleanupAtProcExit (void)
 
void SyncRepInitConfig (void)
 
void SyncRepReleaseWaiters (void)
 
int SyncRepGetCandidateStandbys (SyncRepStandbyData **standbys)
 
void SyncRepUpdateSyncStandbysDefined (void)
 
int syncrep_yyparse (SyncRepConfigData **syncrep_parse_result_p, char **syncrep_parse_error_msg_p, yyscan_t yyscanner)
 
int syncrep_yylex (union YYSTYPE *yylval_param, char **syncrep_parse_error_msg_p, yyscan_t yyscanner)
 
void syncrep_yyerror (SyncRepConfigData **syncrep_parse_result_p, char **syncrep_parse_error_msg_p, yyscan_t yyscanner, const char *str)
 
void syncrep_scanner_init (const char *str, yyscan_t *yyscannerp)
 
void syncrep_scanner_finish (yyscan_t yyscanner)
 

Variables

PGDLLIMPORT SyncRepConfigDataSyncRepConfig
 
PGDLLIMPORT char * SyncRepStandbyNames
 

Macro Definition Documentation

◆ NUM_SYNC_REP_WAIT_MODE

#define NUM_SYNC_REP_WAIT_MODE   3

Definition at line 27 of file syncrep.h.

◆ SYNC_REP_NO_WAIT

#define SYNC_REP_NO_WAIT   (-1)

Definition at line 22 of file syncrep.h.

◆ SYNC_REP_NOT_WAITING

#define SYNC_REP_NOT_WAITING   0

Definition at line 30 of file syncrep.h.

◆ SYNC_REP_PRIORITY

#define SYNC_REP_PRIORITY   0

Definition at line 35 of file syncrep.h.

◆ SYNC_REP_QUORUM

#define SYNC_REP_QUORUM   1

Definition at line 36 of file syncrep.h.

◆ SYNC_REP_WAIT_APPLY

#define SYNC_REP_WAIT_APPLY   2

Definition at line 25 of file syncrep.h.

◆ SYNC_REP_WAIT_COMPLETE

#define SYNC_REP_WAIT_COMPLETE   2

Definition at line 32 of file syncrep.h.

◆ SYNC_REP_WAIT_FLUSH

#define SYNC_REP_WAIT_FLUSH   1

Definition at line 24 of file syncrep.h.

◆ SYNC_REP_WAIT_WRITE

#define SYNC_REP_WAIT_WRITE   0

Definition at line 23 of file syncrep.h.

◆ SYNC_REP_WAITING

#define SYNC_REP_WAITING   1

Definition at line 31 of file syncrep.h.

◆ SyncRepRequested

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

Definition at line 18 of file syncrep.h.

◆ YY_TYPEDEF_YY_SCANNER_T

#define YY_TYPEDEF_YY_SCANNER_T

Definition at line 101 of file syncrep.h.

Typedef Documentation

◆ SyncRepConfigData

◆ SyncRepStandbyData

◆ yyscan_t

typedef void* yyscan_t

Definition at line 102 of file syncrep.h.

Function Documentation

◆ syncrep_scanner_finish()

void syncrep_scanner_finish ( yyscan_t  yyscanner)

Definition at line 190 of file syncrep_scanner.l.

191{
192 pfree(yyextra);
193 yylex_destroy(yyscanner);
194}
void pfree(void *pointer)
Definition: mcxt.c:1524
#define yyextra

References pfree(), and yyextra.

Referenced by check_synchronous_standby_names().

◆ syncrep_scanner_init()

void syncrep_scanner_init ( const char *  str,
yyscan_t yyscannerp 
)

Definition at line 174 of file syncrep_scanner.l.

175{
176 yyscan_t yyscanner;
178
179 if (yylex_init(yyscannerp) != 0)
180 elog(ERROR, "yylex_init() failed: %m");
181
182 yyscanner = *yyscannerp;
183
184 yyset_extra(yyext, yyscanner);
185
186 yy_scan_string(str, yyscanner);
187}
void * yyscan_t
Definition: cubedata.h:67
#define ERROR
Definition: elog.h:39
#define elog(elevel,...)
Definition: elog.h:225
#define palloc0_object(type)
Definition: fe_memutils.h:75
const char * str

References elog, ERROR, palloc0_object, and str.

Referenced by check_synchronous_standby_names().

◆ syncrep_yyerror()

void syncrep_yyerror ( SyncRepConfigData **  syncrep_parse_result_p,
char **  syncrep_parse_error_msg_p,
yyscan_t  yyscanner,
const char *  str 
)

Definition at line 156 of file syncrep_scanner.l.

157{
158 struct yyguts_t *yyg = (struct yyguts_t *) yyscanner; /* needed for yytext
159 * macro */
160 char *syncrep_parse_error_msg = *syncrep_parse_error_msg_p;
161
162 /* report only the first error in a parse operation */
163 if (syncrep_parse_error_msg)
164 return;
165 if (yytext[0])
166 syncrep_parse_error_msg = psprintf("%s at or near \"%s\"",
167 message, yytext);
168 else
169 syncrep_parse_error_msg = psprintf("%s at end of input",
170 message);
171}
char * psprintf(const char *fmt,...)
Definition: psprintf.c:43

References psprintf().

◆ syncrep_yylex()

int syncrep_yylex ( union YYSTYPE yylval_param,
char **  syncrep_parse_error_msg_p,
yyscan_t  yyscanner 
)

◆ syncrep_yyparse()

int syncrep_yyparse ( SyncRepConfigData **  syncrep_parse_result_p,
char **  syncrep_parse_error_msg_p,
yyscan_t  yyscanner 
)

◆ SyncRepCleanupAtProcExit()

void SyncRepCleanupAtProcExit ( void  )

Definition at line 373 of file syncrep.c.

374{
375 /*
376 * First check if we are removed from the queue without the lock to not
377 * slow down backend exit.
378 */
380 {
381 LWLockAcquire(SyncRepLock, LW_EXCLUSIVE);
382
383 /* maybe we have just been removed, so recheck */
386
387 LWLockRelease(SyncRepLock);
388 }
389}
static void dlist_delete_thoroughly(dlist_node *node)
Definition: ilist.h:416
static bool dlist_node_is_detached(const dlist_node *node)
Definition: ilist.h:525
bool LWLockAcquire(LWLock *lock, LWLockMode mode)
Definition: lwlock.c:1178
void LWLockRelease(LWLock *lock)
Definition: lwlock.c:1898
@ LW_EXCLUSIVE
Definition: lwlock.h:114
PGPROC * MyProc
Definition: proc.c:66
dlist_node syncRepLinks
Definition: proc.h:255

References dlist_delete_thoroughly(), dlist_node_is_detached(), LW_EXCLUSIVE, LWLockAcquire(), LWLockRelease(), MyProc, and PGPROC::syncRepLinks.

Referenced by ProcKill().

◆ SyncRepGetCandidateStandbys()

int SyncRepGetCandidateStandbys ( SyncRepStandbyData **  standbys)

Definition at line 711 of file syncrep.c.

712{
713 int i;
714 int n;
715
716 /* Create result array */
717 *standbys = (SyncRepStandbyData *)
719
720 /* Quick exit if sync replication is not requested */
721 if (SyncRepConfig == NULL)
722 return 0;
723
724 /* Collect raw data from shared memory */
725 n = 0;
726 for (i = 0; i < max_wal_senders; i++)
727 {
728 volatile WalSnd *walsnd; /* Use volatile pointer to prevent code
729 * rearrangement */
730 SyncRepStandbyData *stby;
731 WalSndState state; /* not included in SyncRepStandbyData */
732
733 walsnd = &WalSndCtl->walsnds[i];
734 stby = *standbys + n;
735
736 SpinLockAcquire(&walsnd->mutex);
737 stby->pid = walsnd->pid;
738 state = walsnd->state;
739 stby->write = walsnd->write;
740 stby->flush = walsnd->flush;
741 stby->apply = walsnd->apply;
743 SpinLockRelease(&walsnd->mutex);
744
745 /* Must be active */
746 if (stby->pid == 0)
747 continue;
748
749 /* Must be streaming or stopping */
752 continue;
753
754 /* Must be synchronous */
755 if (stby->sync_standby_priority == 0)
756 continue;
757
758 /* Must have a valid flush position */
759 if (XLogRecPtrIsInvalid(stby->flush))
760 continue;
761
762 /* OK, it's a candidate */
763 stby->walsnd_index = i;
764 stby->is_me = (walsnd == MyWalSnd);
765 n++;
766 }
767
768 /*
769 * In quorum mode, we return all the candidates. In priority mode, if we
770 * have too many candidates then return only the num_sync ones of highest
771 * priority.
772 */
775 {
776 /* Sort by priority ... */
777 qsort(*standbys, n, sizeof(SyncRepStandbyData),
779 /* ... then report just the first num_sync ones */
781 }
782
783 return n;
784}
int i
Definition: isn.c:72
void * palloc(Size size)
Definition: mcxt.c:1317
#define qsort(a, b, c, d)
Definition: port.h:475
#define SpinLockRelease(lock)
Definition: spin.h:61
#define SpinLockAcquire(lock)
Definition: spin.h:59
uint8 syncrep_method
Definition: syncrep.h:68
int sync_standby_priority
Definition: syncrep.h:49
XLogRecPtr apply
Definition: syncrep.h:48
XLogRecPtr write
Definition: syncrep.h:46
XLogRecPtr flush
Definition: syncrep.h:47
WalSnd walsnds[FLEXIBLE_ARRAY_MEMBER]
slock_t mutex
XLogRecPtr flush
WalSndState state
XLogRecPtr write
int sync_standby_priority
XLogRecPtr apply
Definition: regguts.h:323
static int standby_priority_comparator(const void *a, const void *b)
Definition: syncrep.c:790
SyncRepConfigData * SyncRepConfig
Definition: syncrep.c:97
#define SYNC_REP_PRIORITY
Definition: syncrep.h:35
WalSnd * MyWalSnd
Definition: walsender.c:112
int max_wal_senders
Definition: walsender.c:121
WalSndCtlData * WalSndCtl
Definition: walsender.c:109
WalSndState
@ WALSNDSTATE_STREAMING
@ WALSNDSTATE_STOPPING
#define XLogRecPtrIsInvalid(r)
Definition: xlogdefs.h:29

References SyncRepStandbyData::apply, WalSnd::apply, SyncRepStandbyData::flush, WalSnd::flush, i, SyncRepStandbyData::is_me, max_wal_senders, WalSnd::mutex, MyWalSnd, SyncRepConfigData::num_sync, palloc(), SyncRepStandbyData::pid, WalSnd::pid, qsort, SpinLockAcquire, SpinLockRelease, standby_priority_comparator(), WalSnd::state, SYNC_REP_PRIORITY, SyncRepStandbyData::sync_standby_priority, WalSnd::sync_standby_priority, SyncRepConfigData::syncrep_method, SyncRepConfig, SyncRepStandbyData::walsnd_index, WalSndCtl, WalSndCtlData::walsnds, WALSNDSTATE_STOPPING, WALSNDSTATE_STREAMING, SyncRepStandbyData::write, WalSnd::write, and XLogRecPtrIsInvalid.

Referenced by pg_stat_get_wal_senders(), and SyncRepGetSyncRecPtr().

◆ SyncRepInitConfig()

void SyncRepInitConfig ( void  )

Definition at line 402 of file syncrep.c.

403{
404 int priority;
405
406 /*
407 * Determine if we are a potential sync standby and remember the result
408 * for handling replies from standby.
409 */
410 priority = SyncRepGetStandbyPriority();
411 if (MyWalSnd->sync_standby_priority != priority)
412 {
416
418 (errmsg_internal("standby \"%s\" now has synchronous standby priority %d",
419 application_name, priority)));
420 }
421}
int errmsg_internal(const char *fmt,...)
Definition: elog.c:1157
#define DEBUG1
Definition: elog.h:30
#define ereport(elevel,...)
Definition: elog.h:149
char * application_name
Definition: guc_tables.c:545
static int SyncRepGetStandbyPriority(void)
Definition: syncrep.c:817

References application_name, DEBUG1, ereport, errmsg_internal(), WalSnd::mutex, MyWalSnd, SpinLockAcquire, SpinLockRelease, WalSnd::sync_standby_priority, and SyncRepGetStandbyPriority().

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

◆ SyncRepReleaseWaiters()

void SyncRepReleaseWaiters ( void  )

Definition at line 431 of file syncrep.c.

432{
433 volatile WalSndCtlData *walsndctl = WalSndCtl;
434 XLogRecPtr writePtr;
435 XLogRecPtr flushPtr;
436 XLogRecPtr applyPtr;
437 bool got_recptr;
438 bool am_sync;
439 int numwrite = 0;
440 int numflush = 0;
441 int numapply = 0;
442
443 /*
444 * If this WALSender is serving a standby that is not on the list of
445 * potential sync standbys then we have nothing to do. If we are still
446 * starting up, still running base backup or the current flush position is
447 * still invalid, then leave quickly also. Streaming or stopping WAL
448 * senders are allowed to release waiters.
449 */
454 {
456 return;
457 }
458
459 /*
460 * We're a potential sync standby. Release waiters if there are enough
461 * sync standbys and we are considered as sync.
462 */
463 LWLockAcquire(SyncRepLock, LW_EXCLUSIVE);
464
465 /*
466 * Check whether we are a sync standby or not, and calculate the synced
467 * positions among all sync standbys. (Note: although this step does not
468 * of itself require holding SyncRepLock, it seems like a good idea to do
469 * it after acquiring the lock. This ensures that the WAL pointers we use
470 * to release waiters are newer than any previous execution of this
471 * routine used.)
472 */
473 got_recptr = SyncRepGetSyncRecPtr(&writePtr, &flushPtr, &applyPtr, &am_sync);
474
475 /*
476 * If we are managing a sync standby, though we weren't prior to this,
477 * then announce we are now a sync standby.
478 */
479 if (announce_next_takeover && am_sync)
480 {
482
484 ereport(LOG,
485 (errmsg("standby \"%s\" is now a synchronous standby with priority %d",
487 else
488 ereport(LOG,
489 (errmsg("standby \"%s\" is now a candidate for quorum synchronous standby",
491 }
492
493 /*
494 * If the number of sync standbys is less than requested or we aren't
495 * managing a sync standby then just leave.
496 */
497 if (!got_recptr || !am_sync)
498 {
499 LWLockRelease(SyncRepLock);
500 announce_next_takeover = !am_sync;
501 return;
502 }
503
504 /*
505 * Set the lsn first so that when we wake backends they will release up to
506 * this location.
507 */
508 if (walsndctl->lsn[SYNC_REP_WAIT_WRITE] < writePtr)
509 {
510 walsndctl->lsn[SYNC_REP_WAIT_WRITE] = writePtr;
511 numwrite = SyncRepWakeQueue(false, SYNC_REP_WAIT_WRITE);
512 }
513 if (walsndctl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr)
514 {
515 walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr;
516 numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH);
517 }
518 if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr)
519 {
520 walsndctl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr;
521 numapply = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY);
522 }
523
524 LWLockRelease(SyncRepLock);
525
526 elog(DEBUG3, "released %d procs up to write %X/%X, %d procs up to flush %X/%X, %d procs up to apply %X/%X",
527 numwrite, LSN_FORMAT_ARGS(writePtr),
528 numflush, LSN_FORMAT_ARGS(flushPtr),
529 numapply, LSN_FORMAT_ARGS(applyPtr));
530}
int errmsg(const char *fmt,...)
Definition: elog.c:1070
#define LOG
Definition: elog.h:31
#define DEBUG3
Definition: elog.h:28
XLogRecPtr lsn[NUM_SYNC_REP_WAIT_MODE]
static bool SyncRepGetSyncRecPtr(XLogRecPtr *writePtr, XLogRecPtr *flushPtr, XLogRecPtr *applyPtr, bool *am_sync)
Definition: syncrep.c:543
static int SyncRepWakeQueue(bool all, int mode)
Definition: syncrep.c:864
static bool announce_next_takeover
Definition: syncrep.c:95
#define SYNC_REP_WAIT_WRITE
Definition: syncrep.h:23
#define SYNC_REP_WAIT_FLUSH
Definition: syncrep.h:24
#define SYNC_REP_WAIT_APPLY
Definition: syncrep.h:25
#define LSN_FORMAT_ARGS(lsn)
Definition: xlogdefs.h:43
uint64 XLogRecPtr
Definition: xlogdefs.h:21

References announce_next_takeover, application_name, DEBUG3, elog, ereport, errmsg(), WalSnd::flush, LOG, WalSndCtlData::lsn, LSN_FORMAT_ARGS, 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, SyncRepConfig, SyncRepGetSyncRecPtr(), SyncRepWakeQueue(), WalSndCtl, WALSNDSTATE_STOPPING, WALSNDSTATE_STREAMING, and XLogRecPtrIsInvalid.

Referenced by ProcessStandbyReplyMessage().

◆ SyncRepUpdateSyncStandbysDefined()

void SyncRepUpdateSyncStandbysDefined ( void  )

Definition at line 921 of file syncrep.c.

922{
923 bool sync_standbys_defined = SyncStandbysDefined();
924
925 if (sync_standbys_defined != WalSndCtl->sync_standbys_defined)
926 {
927 LWLockAcquire(SyncRepLock, LW_EXCLUSIVE);
928
929 /*
930 * If synchronous_standby_names has been reset to empty, it's futile
931 * for backends to continue waiting. Since the user no longer wants
932 * synchronous replication, we'd better wake them up.
933 */
934 if (!sync_standbys_defined)
935 {
936 int i;
937
938 for (i = 0; i < NUM_SYNC_REP_WAIT_MODE; i++)
939 SyncRepWakeQueue(true, i);
940 }
941
942 /*
943 * Only allow people to join the queue when there are synchronous
944 * standbys defined. Without this interlock, there's a race
945 * condition: we might wake up all the current waiters; then, some
946 * backend that hasn't yet reloaded its config might go to sleep on
947 * the queue (and never wake up). This prevents that.
948 */
949 WalSndCtl->sync_standbys_defined = sync_standbys_defined;
950
951 LWLockRelease(SyncRepLock);
952 }
953}
#define SyncStandbysDefined()
Definition: syncrep.c:92
#define NUM_SYNC_REP_WAIT_MODE
Definition: syncrep.h:27

References i, LW_EXCLUSIVE, LWLockAcquire(), LWLockRelease(), NUM_SYNC_REP_WAIT_MODE, WalSndCtlData::sync_standbys_defined, SyncRepWakeQueue(), SyncStandbysDefined, and WalSndCtl.

Referenced by UpdateSharedMemoryConfig().

◆ SyncRepWaitForLSN()

void SyncRepWaitForLSN ( XLogRecPtr  lsn,
bool  commit 
)

Definition at line 148 of file syncrep.c.

149{
150 int mode;
151
152 /*
153 * This should be called while holding interrupts during a transaction
154 * commit to prevent the follow-up shared memory queue cleanups to be
155 * influenced by external interruptions.
156 */
158
159 /*
160 * Fast exit if user has not requested sync replication, or there are no
161 * sync replication standby names defined.
162 *
163 * Since this routine gets called every commit time, it's important to
164 * exit quickly if sync replication is not requested. So we check
165 * WalSndCtl->sync_standbys_defined flag without the lock and exit
166 * immediately if it's false. If it's true, we need to check it again
167 * later while holding the lock, to check the flag and operate the sync
168 * rep queue atomically. This is necessary to avoid the race condition
169 * described in SyncRepUpdateSyncStandbysDefined(). On the other hand, if
170 * it's false, the lock is not necessary because we don't touch the queue.
171 */
172 if (!SyncRepRequested() ||
173 !((volatile WalSndCtlData *) WalSndCtl)->sync_standbys_defined)
174 return;
175
176 /* Cap the level for anything other than commit to remote flush only. */
177 if (commit)
179 else
181
183 Assert(WalSndCtl != NULL);
184
185 LWLockAcquire(SyncRepLock, LW_EXCLUSIVE);
187
188 /*
189 * We don't wait for sync rep if WalSndCtl->sync_standbys_defined is not
190 * set. See SyncRepUpdateSyncStandbysDefined.
191 *
192 * Also check that the standby hasn't already replied. Unlikely race
193 * condition but we'll be fetching that cache line anyway so it's likely
194 * to be a low cost check.
195 */
197 lsn <= WalSndCtl->lsn[mode])
198 {
199 LWLockRelease(SyncRepLock);
200 return;
201 }
202
203 /*
204 * Set our waitLSN so WALSender will know when to wake us, and add
205 * ourselves to the queue.
206 */
207 MyProc->waitLSN = lsn;
210 Assert(SyncRepQueueIsOrderedByLSN(mode));
211 LWLockRelease(SyncRepLock);
212
213 /* Alter ps display to show waiting for sync rep. */
215 {
216 char buffer[32];
217
218 sprintf(buffer, "waiting for %X/%X", LSN_FORMAT_ARGS(lsn));
219 set_ps_display_suffix(buffer);
220 }
221
222 /*
223 * Wait for specified LSN to be confirmed.
224 *
225 * Each proc has its own wait latch, so we perform a normal latch
226 * check/wait loop here.
227 */
228 for (;;)
229 {
230 int rc;
231
232 /* Must reset the latch before testing state. */
234
235 /*
236 * Acquiring the lock is not needed, the latch ensures proper
237 * barriers. If it looks like we're done, we must really be done,
238 * because once walsender changes the state to SYNC_REP_WAIT_COMPLETE,
239 * it will never update it again, so we can't be seeing a stale value
240 * in that case.
241 */
243 break;
244
245 /*
246 * If a wait for synchronous replication is pending, we can neither
247 * acknowledge the commit nor raise ERROR or FATAL. The latter would
248 * lead the client to believe that the transaction aborted, which is
249 * not true: it's already committed locally. The former is no good
250 * either: the client has requested synchronous replication, and is
251 * entitled to assume that an acknowledged commit is also replicated,
252 * which might not be true. So in this case we issue a WARNING (which
253 * some clients may be able to interpret) and shut off further output.
254 * We do NOT reset ProcDiePending, so that the process will die after
255 * the commit is cleaned up.
256 */
257 if (ProcDiePending)
258 {
260 (errcode(ERRCODE_ADMIN_SHUTDOWN),
261 errmsg("canceling the wait for synchronous replication and terminating connection due to administrator command"),
262 errdetail("The transaction has already committed locally, but might not have been replicated to the standby.")));
265 break;
266 }
267
268 /*
269 * It's unclear what to do if a query cancel interrupt arrives. We
270 * can't actually abort at this point, but ignoring the interrupt
271 * altogether is not helpful, so we just terminate the wait with a
272 * suitable warning.
273 */
275 {
276 QueryCancelPending = false;
278 (errmsg("canceling wait for synchronous replication due to user request"),
279 errdetail("The transaction has already committed locally, but might not have been replicated to the standby.")));
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 */
289 WAIT_EVENT_SYNC_REP);
290
291 /*
292 * If the postmaster dies, we'll probably never get an acknowledgment,
293 * because all the wal sender processes will exit. So just bail out.
294 */
295 if (rc & WL_POSTMASTER_DEATH)
296 {
297 ProcDiePending = true;
300 break;
301 }
302 }
303
304 /*
305 * WalSender has checked our LSN and has removed us from queue. Clean up
306 * state and leave. It's OK to reset these shared memory fields without
307 * holding SyncRepLock, because any walsenders will ignore us anyway when
308 * we're not on the queue. We need a read barrier to make sure we see the
309 * changes to the queue link (this might be unnecessary without
310 * assertions, but better safe than sorry).
311 */
315 MyProc->waitLSN = 0;
316
317 /* reset ps display to remove the suffix */
320}
#define pg_read_barrier()
Definition: atomics.h:156
#define Min(x, y)
Definition: c.h:961
#define Assert(condition)
Definition: c.h:815
@ DestNone
Definition: dest.h:87
int errdetail(const char *fmt,...)
Definition: elog.c:1203
int errcode(int sqlerrcode)
Definition: elog.c:853
#define WARNING
Definition: elog.h:36
volatile uint32 InterruptHoldoffCount
Definition: globals.c:42
volatile sig_atomic_t QueryCancelPending
Definition: globals.c:32
struct Latch * MyLatch
Definition: globals.c:62
volatile sig_atomic_t ProcDiePending
Definition: globals.c:33
void ResetLatch(Latch *latch)
Definition: latch.c:372
int WaitLatch(Latch *latch, int wakeEvents, long timeout, uint32 wait_event_info)
Definition: latch.c:172
static PgChecksumMode mode
Definition: pg_checksums.c:55
#define sprintf
Definition: port.h:241
CommandDest whereToSendOutput
Definition: postgres.c:90
void set_ps_display_remove_suffix(void)
Definition: ps_status.c:423
void set_ps_display_suffix(const char *suffix)
Definition: ps_status.c:371
bool update_process_title
Definition: ps_status.c:31
XLogRecPtr waitLSN
Definition: proc.h:253
int syncRepState
Definition: proc.h:254
static int SyncRepWaitMode
Definition: syncrep.c:98
static void SyncRepQueueInsert(int mode)
Definition: syncrep.c:329
static void SyncRepCancelWait(void)
Definition: syncrep.c:363
#define SyncRepRequested()
Definition: syncrep.h:18
#define SYNC_REP_WAITING
Definition: syncrep.h:31
#define SYNC_REP_WAIT_COMPLETE
Definition: syncrep.h:32
#define SYNC_REP_NOT_WAITING
Definition: syncrep.h:30
#define WL_LATCH_SET
Definition: waiteventset.h:34
#define WL_POSTMASTER_DEATH
Definition: waiteventset.h:38

References Assert, DestNone, dlist_node_is_detached(), ereport, errcode(), errdetail(), errmsg(), InterruptHoldoffCount, LSN_FORMAT_ARGS, LW_EXCLUSIVE, LWLockAcquire(), LWLockRelease(), Min, mode, MyLatch, MyProc, pg_read_barrier, ProcDiePending, QueryCancelPending, ResetLatch(), set_ps_display_remove_suffix(), set_ps_display_suffix(), sprintf, 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, update_process_title, WaitLatch(), PGPROC::waitLSN, WalSndCtl, WARNING, whereToSendOutput, WL_LATCH_SET, and WL_POSTMASTER_DEATH.

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

Variable Documentation

◆ SyncRepConfig

◆ SyncRepStandbyNames

PGDLLIMPORT char* SyncRepStandbyNames
extern

Definition at line 90 of file syncrep.c.