PostgreSQL Source Code  git master
checkpointer.c File Reference
#include "postgres.h"
#include <sys/time.h>
#include "access/xlog.h"
#include "access/xlog_internal.h"
#include "access/xlogrecovery.h"
#include "libpq/pqsignal.h"
#include "miscadmin.h"
#include "pgstat.h"
#include "postmaster/auxprocess.h"
#include "postmaster/bgwriter.h"
#include "postmaster/interrupt.h"
#include "replication/syncrep.h"
#include "storage/bufmgr.h"
#include "storage/condition_variable.h"
#include "storage/fd.h"
#include "storage/ipc.h"
#include "storage/lwlock.h"
#include "storage/proc.h"
#include "storage/procsignal.h"
#include "storage/shmem.h"
#include "storage/smgr.h"
#include "storage/spin.h"
#include "utils/guc.h"
#include "utils/memutils.h"
#include "utils/resowner.h"
Include dependency graph for checkpointer.c:

Go to the source code of this file.

Data Structures

struct  CheckpointerRequest
 
struct  CheckpointerShmemStruct
 

Macros

#define WRITES_PER_ABSORB   1000
 
#define MAX_SIGNAL_TRIES   600 /* max wait 60.0 sec */
 

Functions

static void HandleCheckpointerInterrupts (void)
 
static void CheckArchiveTimeout (void)
 
static bool IsCheckpointOnSchedule (double progress)
 
static bool ImmediateCheckpointRequested (void)
 
static bool CompactCheckpointerRequestQueue (void)
 
static void UpdateSharedMemoryConfig (void)
 
static void ReqCheckpointHandler (SIGNAL_ARGS)
 
void CheckpointerMain (char *startup_data, size_t startup_data_len)
 
void CheckpointWriteDelay (int flags, double progress)
 
Size CheckpointerShmemSize (void)
 
void CheckpointerShmemInit (void)
 
void RequestCheckpoint (int flags)
 
bool ForwardSyncRequest (const FileTag *ftag, SyncRequestType type)
 
void AbsorbSyncRequests (void)
 
bool FirstCallSinceLastCheckpoint (void)
 

Variables

static CheckpointerShmemStructCheckpointerShmem
 
int CheckPointTimeout = 300
 
int CheckPointWarning = 30
 
double CheckPointCompletionTarget = 0.9
 
static bool ckpt_active = false
 
static pg_time_t ckpt_start_time
 
static XLogRecPtr ckpt_start_recptr
 
static double ckpt_cached_elapsed
 
static pg_time_t last_checkpoint_time
 
static pg_time_t last_xlog_switch_time
 

Macro Definition Documentation

◆ MAX_SIGNAL_TRIES

#define MAX_SIGNAL_TRIES   600 /* max wait 60.0 sec */

◆ WRITES_PER_ABSORB

#define WRITES_PER_ABSORB   1000

Definition at line 131 of file checkpointer.c.

Function Documentation

◆ AbsorbSyncRequests()

void AbsorbSyncRequests ( void  )

Definition at line 1260 of file checkpointer.c.

1261 {
1262  CheckpointerRequest *requests = NULL;
1263  CheckpointerRequest *request;
1264  int n;
1265 
1266  if (!AmCheckpointerProcess())
1267  return;
1268 
1269  LWLockAcquire(CheckpointerCommLock, LW_EXCLUSIVE);
1270 
1271  /*
1272  * We try to avoid holding the lock for a long time by copying the request
1273  * array, and processing the requests after releasing the lock.
1274  *
1275  * Once we have cleared the requests from shared memory, we have to PANIC
1276  * if we then fail to absorb them (eg, because our hashtable runs out of
1277  * memory). This is because the system cannot run safely if we are unable
1278  * to fsync what we have been told to fsync. Fortunately, the hashtable
1279  * is so small that the problem is quite unlikely to arise in practice.
1280  */
1282  if (n > 0)
1283  {
1284  requests = (CheckpointerRequest *) palloc(n * sizeof(CheckpointerRequest));
1285  memcpy(requests, CheckpointerShmem->requests, n * sizeof(CheckpointerRequest));
1286  }
1287 
1289 
1291 
1292  LWLockRelease(CheckpointerCommLock);
1293 
1294  for (request = requests; n > 0; request++, n--)
1295  RememberSyncRequest(&request->ftag, request->type);
1296 
1297  END_CRIT_SECTION();
1298 
1299  if (requests)
1300  pfree(requests);
1301 }
static CheckpointerShmemStruct * CheckpointerShmem
Definition: checkpointer.c:128
bool LWLockAcquire(LWLock *lock, LWLockMode mode)
Definition: lwlock.c:1170
void LWLockRelease(LWLock *lock)
Definition: lwlock.c:1783
@ LW_EXCLUSIVE
Definition: lwlock.h:114
void pfree(void *pointer)
Definition: mcxt.c:1520
void * palloc(Size size)
Definition: mcxt.c:1316
#define AmCheckpointerProcess()
Definition: miscadmin.h:381
#define START_CRIT_SECTION()
Definition: miscadmin.h:149
#define END_CRIT_SECTION()
Definition: miscadmin.h:151
SyncRequestType type
Definition: checkpointer.c:104
CheckpointerRequest requests[FLEXIBLE_ARRAY_MEMBER]
Definition: checkpointer.c:125
void RememberSyncRequest(const FileTag *ftag, SyncRequestType type)
Definition: sync.c:487

References AmCheckpointerProcess, CheckpointerShmem, END_CRIT_SECTION, CheckpointerRequest::ftag, LW_EXCLUSIVE, LWLockAcquire(), LWLockRelease(), CheckpointerShmemStruct::num_requests, palloc(), pfree(), RememberSyncRequest(), CheckpointerShmemStruct::requests, START_CRIT_SECTION, and CheckpointerRequest::type.

Referenced by CheckpointerMain(), CheckpointWriteDelay(), ProcessSyncRequests(), SyncPostCheckpoint(), and SyncPreCheckpoint().

◆ CheckArchiveTimeout()

static void CheckArchiveTimeout ( void  )
static

Definition at line 623 of file checkpointer.c.

624 {
625  pg_time_t now;
626  pg_time_t last_time;
627  XLogRecPtr last_switch_lsn;
628 
630  return;
631 
632  now = (pg_time_t) time(NULL);
633 
634  /* First we do a quick check using possibly-stale local state. */
636  return;
637 
638  /*
639  * Update local state ... note that last_xlog_switch_time is the last time
640  * a switch was performed *or requested*.
641  */
642  last_time = GetLastSegSwitchData(&last_switch_lsn);
643 
645 
646  /* Now we can do the real checks */
648  {
649  /*
650  * Switch segment only when "important" WAL has been logged since the
651  * last segment switch (last_switch_lsn points to end of segment
652  * switch occurred in).
653  */
654  if (GetLastImportantRecPtr() > last_switch_lsn)
655  {
656  XLogRecPtr switchpoint;
657 
658  /* mark switch as unimportant, avoids triggering checkpoints */
659  switchpoint = RequestXLogSwitch(true);
660 
661  /*
662  * If the returned pointer points exactly to a segment boundary,
663  * assume nothing happened.
664  */
665  if (XLogSegmentOffset(switchpoint, wal_segment_size) != 0)
666  elog(DEBUG1, "write-ahead log switch forced (archive_timeout=%d)",
668  }
669 
670  /*
671  * Update state in any case, so we don't retry constantly when the
672  * system is idle.
673  */
675  }
676 }
Datum now(PG_FUNCTION_ARGS)
Definition: timestamp.c:1618
#define Max(x, y)
Definition: c.h:998
static pg_time_t last_xlog_switch_time
Definition: checkpointer.c:151
#define DEBUG1
Definition: elog.h:30
#define elog(elevel,...)
Definition: elog.h:224
int64 pg_time_t
Definition: pgtime.h:23
bool RecoveryInProgress(void)
Definition: xlog.c:6290
XLogRecPtr RequestXLogSwitch(bool mark_unimportant)
Definition: xlog.c:7981
int wal_segment_size
Definition: xlog.c:143
int XLogArchiveTimeout
Definition: xlog.c:118
pg_time_t GetLastSegSwitchData(XLogRecPtr *lastSwitchLSN)
Definition: xlog.c:6522
XLogRecPtr GetLastImportantRecPtr(void)
Definition: xlog.c:6493
#define XLogSegmentOffset(xlogptr, wal_segsz_bytes)
uint64 XLogRecPtr
Definition: xlogdefs.h:21

References DEBUG1, elog, GetLastImportantRecPtr(), GetLastSegSwitchData(), last_xlog_switch_time, Max, now(), RecoveryInProgress(), RequestXLogSwitch(), wal_segment_size, XLogArchiveTimeout, and XLogSegmentOffset.

Referenced by CheckpointerMain(), and CheckpointWriteDelay().

◆ CheckpointerMain()

void CheckpointerMain ( char *  startup_data,
size_t  startup_data_len 
)

Definition at line 173 of file checkpointer.c.

174 {
175  sigjmp_buf local_sigjmp_buf;
176  MemoryContext checkpointer_context;
177 
178  Assert(startup_data_len == 0);
179 
182 
184 
185  /*
186  * Properly accept or ignore signals the postmaster might send us
187  *
188  * Note: we deliberately ignore SIGTERM, because during a standard Unix
189  * system shutdown cycle, init will SIGTERM all processes at once. We
190  * want to wait for the backends to exit, whereupon the postmaster will
191  * tell us it's okay to shut down (via SIGUSR2).
192  */
194  pqsignal(SIGINT, ReqCheckpointHandler); /* request checkpoint */
195  pqsignal(SIGTERM, SIG_IGN); /* ignore SIGTERM */
196  /* SIGQUIT handler was already set up by InitPostmasterChild */
201 
202  /*
203  * Reset some signals that are accepted by postmaster but not here
204  */
206 
207  /*
208  * Initialize so that first time-driven event happens at the correct time.
209  */
211 
212  /*
213  * Write out stats after shutdown. This needs to be called by exactly one
214  * process during a normal shutdown, and since checkpointer is shut down
215  * very late...
216  *
217  * Walsenders are shut down after the checkpointer, but currently don't
218  * report stats. If that changes, we need a more complicated solution.
219  */
221 
222  /*
223  * Create a memory context that we will do all our work in. We do this so
224  * that we can reset the context during error recovery and thereby avoid
225  * possible memory leaks. Formerly this code just ran in
226  * TopMemoryContext, but resetting that would be a really bad idea.
227  */
228  checkpointer_context = AllocSetContextCreate(TopMemoryContext,
229  "Checkpointer",
231  MemoryContextSwitchTo(checkpointer_context);
232 
233  /*
234  * If an exception is encountered, processing resumes here.
235  *
236  * You might wonder why this isn't coded as an infinite loop around a
237  * PG_TRY construct. The reason is that this is the bottom of the
238  * exception stack, and so with PG_TRY there would be no exception handler
239  * in force at all during the CATCH part. By leaving the outermost setjmp
240  * always active, we have at least some chance of recovering from an error
241  * during error recovery. (If we get into an infinite loop thereby, it
242  * will soon be stopped by overflow of elog.c's internal state stack.)
243  *
244  * Note that we use sigsetjmp(..., 1), so that the prevailing signal mask
245  * (to wit, BlockSig) will be restored when longjmp'ing to here. Thus,
246  * signals other than SIGQUIT will be blocked until we complete error
247  * recovery. It might seem that this policy makes the HOLD_INTERRUPTS()
248  * call redundant, but it is not since InterruptPending might be set
249  * already.
250  */
251  if (sigsetjmp(local_sigjmp_buf, 1) != 0)
252  {
253  /* Since not using PG_TRY, must reset error stack by hand */
254  error_context_stack = NULL;
255 
256  /* Prevent interrupts while cleaning up */
257  HOLD_INTERRUPTS();
258 
259  /* Report the error to the server log */
260  EmitErrorReport();
261 
262  /*
263  * These operations are really just a minimal subset of
264  * AbortTransaction(). We don't have very many resources to worry
265  * about in checkpointer, but we do have LWLocks, buffers, and temp
266  * files.
267  */
271  UnlockBuffers();
273  AtEOXact_Buffers(false);
274  AtEOXact_SMgr();
275  AtEOXact_Files(false);
276  AtEOXact_HashTables(false);
277 
278  /* Warn any waiting backends that the checkpoint failed. */
279  if (ckpt_active)
280  {
285 
287 
288  ckpt_active = false;
289  }
290 
291  /*
292  * Now return to normal top-level context and clear ErrorContext for
293  * next time.
294  */
295  MemoryContextSwitchTo(checkpointer_context);
296  FlushErrorState();
297 
298  /* Flush any leaked data in the top-level context */
299  MemoryContextReset(checkpointer_context);
300 
301  /* Now we can allow interrupts again */
303 
304  /*
305  * Sleep at least 1 second after any error. A write error is likely
306  * to be repeated, and we don't want to be filling the error logs as
307  * fast as we can.
308  */
309  pg_usleep(1000000L);
310  }
311 
312  /* We can now handle ereport(ERROR) */
313  PG_exception_stack = &local_sigjmp_buf;
314 
315  /*
316  * Unblock signals (they were blocked when the postmaster forked us)
317  */
318  sigprocmask(SIG_SETMASK, &UnBlockSig, NULL);
319 
320  /*
321  * Ensure all shared memory values are set correctly for the config. Doing
322  * this here ensures no race conditions from other concurrent updaters.
323  */
325 
326  /*
327  * Advertise our latch that backends can use to wake us up while we're
328  * sleeping.
329  */
331 
332  /*
333  * Loop forever
334  */
335  for (;;)
336  {
337  bool do_checkpoint = false;
338  int flags = 0;
339  pg_time_t now;
340  int elapsed_secs;
341  int cur_timeout;
342  bool chkpt_or_rstpt_requested = false;
343  bool chkpt_or_rstpt_timed = false;
344 
345  /* Clear any already-pending wakeups */
347 
348  /*
349  * Process any requests or signals received recently.
350  */
353 
354  /*
355  * Detect a pending checkpoint request by checking whether the flags
356  * word in shared memory is nonzero. We shouldn't need to acquire the
357  * ckpt_lck for this.
358  */
359  if (((volatile CheckpointerShmemStruct *) CheckpointerShmem)->ckpt_flags)
360  {
361  do_checkpoint = true;
362  chkpt_or_rstpt_requested = true;
363  }
364 
365  /*
366  * Force a checkpoint if too much time has elapsed since the last one.
367  * Note that we count a timed checkpoint in stats only when this
368  * occurs without an external request, but we set the CAUSE_TIME flag
369  * bit even if there is also an external request.
370  */
371  now = (pg_time_t) time(NULL);
372  elapsed_secs = now - last_checkpoint_time;
373  if (elapsed_secs >= CheckPointTimeout)
374  {
375  if (!do_checkpoint)
376  chkpt_or_rstpt_timed = true;
377  do_checkpoint = true;
378  flags |= CHECKPOINT_CAUSE_TIME;
379  }
380 
381  /*
382  * Do a checkpoint if requested.
383  */
384  if (do_checkpoint)
385  {
386  bool ckpt_performed = false;
387  bool do_restartpoint;
388 
389  /* Check if we should perform a checkpoint or a restartpoint. */
390  do_restartpoint = RecoveryInProgress();
391 
392  /*
393  * Atomically fetch the request flags to figure out what kind of a
394  * checkpoint we should perform, and increase the started-counter
395  * to acknowledge that we've started a new checkpoint.
396  */
398  flags |= CheckpointerShmem->ckpt_flags;
402 
404 
405  /*
406  * The end-of-recovery checkpoint is a real checkpoint that's
407  * performed while we're still in recovery.
408  */
409  if (flags & CHECKPOINT_END_OF_RECOVERY)
410  do_restartpoint = false;
411 
412  if (chkpt_or_rstpt_timed)
413  {
414  chkpt_or_rstpt_timed = false;
415  if (do_restartpoint)
417  else
419  }
420 
421  if (chkpt_or_rstpt_requested)
422  {
423  chkpt_or_rstpt_requested = false;
424  if (do_restartpoint)
426  else
428  }
429 
430  /*
431  * We will warn if (a) too soon since last checkpoint (whatever
432  * caused it) and (b) somebody set the CHECKPOINT_CAUSE_XLOG flag
433  * since the last checkpoint start. Note in particular that this
434  * implementation will not generate warnings caused by
435  * CheckPointTimeout < CheckPointWarning.
436  */
437  if (!do_restartpoint &&
438  (flags & CHECKPOINT_CAUSE_XLOG) &&
439  elapsed_secs < CheckPointWarning)
440  ereport(LOG,
441  (errmsg_plural("checkpoints are occurring too frequently (%d second apart)",
442  "checkpoints are occurring too frequently (%d seconds apart)",
443  elapsed_secs,
444  elapsed_secs),
445  errhint("Consider increasing the configuration parameter \"%s\".", "max_wal_size")));
446 
447  /*
448  * Initialize checkpointer-private variables used during
449  * checkpoint.
450  */
451  ckpt_active = true;
452  if (do_restartpoint)
454  else
458 
459  /*
460  * Do the checkpoint.
461  */
462  if (!do_restartpoint)
463  {
464  CreateCheckPoint(flags);
465  ckpt_performed = true;
466  }
467  else
468  ckpt_performed = CreateRestartPoint(flags);
469 
470  /*
471  * After any checkpoint, free all smgr objects. Otherwise we
472  * would never do so for dropped relations, as the checkpointer
473  * does not process shared invalidation messages or call
474  * AtEOXact_SMgr().
475  */
476  smgrdestroyall();
477 
478  /*
479  * Indicate checkpoint completion to any waiting backends.
480  */
484 
486 
487  if (ckpt_performed)
488  {
489  /*
490  * Note we record the checkpoint start time not end time as
491  * last_checkpoint_time. This is so that time-driven
492  * checkpoints happen at a predictable spacing.
493  */
495 
496  if (do_restartpoint)
498  }
499  else
500  {
501  /*
502  * We were not able to perform the restartpoint (checkpoints
503  * throw an ERROR in case of error). Most likely because we
504  * have not received any new checkpoint WAL records since the
505  * last restartpoint. Try again in 15 s.
506  */
508  }
509 
510  ckpt_active = false;
511 
512  /* We may have received an interrupt during the checkpoint. */
514  }
515 
516  /* Check for archive_timeout and switch xlog files if necessary. */
518 
519  /* Report pending statistics to the cumulative stats system */
521  pgstat_report_wal(true);
522 
523  /*
524  * If any checkpoint flags have been set, redo the loop to handle the
525  * checkpoint without sleeping.
526  */
527  if (((volatile CheckpointerShmemStruct *) CheckpointerShmem)->ckpt_flags)
528  continue;
529 
530  /*
531  * Sleep until we are signaled or it's time for another checkpoint or
532  * xlog file switch.
533  */
534  now = (pg_time_t) time(NULL);
535  elapsed_secs = now - last_checkpoint_time;
536  if (elapsed_secs >= CheckPointTimeout)
537  continue; /* no sleep for us ... */
538  cur_timeout = CheckPointTimeout - elapsed_secs;
540  {
541  elapsed_secs = now - last_xlog_switch_time;
542  if (elapsed_secs >= XLogArchiveTimeout)
543  continue; /* no sleep for us ... */
544  cur_timeout = Min(cur_timeout, XLogArchiveTimeout - elapsed_secs);
545  }
546 
547  (void) WaitLatch(MyLatch,
549  cur_timeout * 1000L /* convert to ms */ ,
550  WAIT_EVENT_CHECKPOINTER_MAIN);
551  }
552 }
void AuxiliaryProcessMainCommon(void)
Definition: auxprocess.c:44
sigset_t UnBlockSig
Definition: pqsignal.c:22
void AtEOXact_Buffers(bool isCommit)
Definition: bufmgr.c:3548
void UnlockBuffers(void)
Definition: bufmgr.c:5103
#define Min(x, y)
Definition: c.h:1004
#define Assert(condition)
Definition: c.h:858
static void UpdateSharedMemoryConfig(void)
static XLogRecPtr ckpt_start_recptr
Definition: checkpointer.c:147
static void ReqCheckpointHandler(SIGNAL_ARGS)
Definition: checkpointer.c:859
static void CheckArchiveTimeout(void)
Definition: checkpointer.c:623
static double ckpt_cached_elapsed
Definition: checkpointer.c:148
static bool ckpt_active
Definition: checkpointer.c:143
static void HandleCheckpointerInterrupts(void)
Definition: checkpointer.c:558
void AbsorbSyncRequests(void)
int CheckPointWarning
Definition: checkpointer.c:137
int CheckPointTimeout
Definition: checkpointer.c:136
static pg_time_t last_checkpoint_time
Definition: checkpointer.c:150
static pg_time_t ckpt_start_time
Definition: checkpointer.c:146
bool ConditionVariableCancelSleep(void)
void ConditionVariableBroadcast(ConditionVariable *cv)
void AtEOXact_HashTables(bool isCommit)
Definition: dynahash.c:1869
int errmsg_plural(const char *fmt_singular, const char *fmt_plural, unsigned long n,...)
Definition: elog.c:1180
void EmitErrorReport(void)
Definition: elog.c:1670
ErrorContextCallback * error_context_stack
Definition: elog.c:94
void FlushErrorState(void)
Definition: elog.c:1834
int errhint(const char *fmt,...)
Definition: elog.c:1317
sigjmp_buf * PG_exception_stack
Definition: elog.c:96
#define LOG
Definition: elog.h:31
#define ereport(elevel,...)
Definition: elog.h:149
void AtEOXact_Files(bool isCommit)
Definition: fd.c:3165
int MyProcPid
Definition: globals.c:45
struct Latch * MyLatch
Definition: globals.c:60
void SignalHandlerForShutdownRequest(SIGNAL_ARGS)
Definition: interrupt.c:105
void SignalHandlerForConfigReload(SIGNAL_ARGS)
Definition: interrupt.c:61
void before_shmem_exit(pg_on_exit_callback function, Datum arg)
Definition: ipc.c:337
void ResetLatch(Latch *latch)
Definition: latch.c:724
int WaitLatch(Latch *latch, int wakeEvents, long timeout, uint32 wait_event_info)
Definition: latch.c:517
#define WL_TIMEOUT
Definition: latch.h:130
#define WL_EXIT_ON_PM_DEATH
Definition: latch.h:132
#define WL_LATCH_SET
Definition: latch.h:127
void LWLockReleaseAll(void)
Definition: lwlock.c:1878
void MemoryContextReset(MemoryContext context)
Definition: mcxt.c:383
MemoryContext TopMemoryContext
Definition: mcxt.c:149
#define AllocSetContextCreate
Definition: memutils.h:129
#define ALLOCSET_DEFAULT_SIZES
Definition: memutils.h:160
#define RESUME_INTERRUPTS()
Definition: miscadmin.h:135
#define HOLD_INTERRUPTS()
Definition: miscadmin.h:133
@ B_CHECKPOINTER
Definition: miscadmin.h:357
BackendType MyBackendType
Definition: miscinit.c:63
void pgstat_before_server_shutdown(int code, Datum arg)
Definition: pgstat.c:462
void pgstat_report_checkpointer(void)
PgStat_CheckpointerStats PendingCheckpointerStats
void pgstat_report_wal(bool force)
Definition: pgstat_wal.c:48
pqsigfunc pqsignal(int signo, pqsigfunc func)
void procsignal_sigusr1_handler(SIGNAL_ARGS)
Definition: procsignal.c:635
MemoryContextSwitchTo(old_ctx)
void ReleaseAuxProcessResources(bool isCommit)
Definition: resowner.c:1002
void pg_usleep(long microsec)
Definition: signal.c:53
void smgrdestroyall(void)
Definition: smgr.c:332
void AtEOXact_SMgr(void)
Definition: smgr.c:807
#define SpinLockRelease(lock)
Definition: spin.h:64
#define SpinLockAcquire(lock)
Definition: spin.h:62
PGPROC * MyProc
Definition: proc.c:66
PROC_HDR * ProcGlobal
Definition: proc.c:78
ConditionVariable done_cv
Definition: checkpointer.c:121
ConditionVariable start_cv
Definition: checkpointer.c:120
Latch procLatch
Definition: proc.h:165
Latch * checkpointerLatch
Definition: proc.h:414
PgStat_Counter restartpoints_requested
Definition: pgstat.h:266
PgStat_Counter num_requested
Definition: pgstat.h:264
PgStat_Counter restartpoints_timed
Definition: pgstat.h:265
PgStat_Counter num_timed
Definition: pgstat.h:263
PgStat_Counter restartpoints_performed
Definition: pgstat.h:267
static void pgstat_report_wait_end(void)
Definition: wait_event.h:98
#define SIGCHLD
Definition: win32_port.h:178
#define SIGHUP
Definition: win32_port.h:168
#define SIG_DFL
Definition: win32_port.h:163
#define SIGPIPE
Definition: win32_port.h:173
#define SIGUSR1
Definition: win32_port.h:180
#define SIGALRM
Definition: win32_port.h:174
#define SIGUSR2
Definition: win32_port.h:181
#define SIG_IGN
Definition: win32_port.h:165
bool CreateRestartPoint(int flags)
Definition: xlog.c:7512
XLogRecPtr GetInsertRecPtr(void)
Definition: xlog.c:6438
void CreateCheckPoint(int flags)
Definition: xlog.c:6821
#define CHECKPOINT_CAUSE_XLOG
Definition: xlog.h:146
#define CHECKPOINT_END_OF_RECOVERY
Definition: xlog.h:138
#define CHECKPOINT_CAUSE_TIME
Definition: xlog.h:147
XLogRecPtr GetXLogReplayRecPtr(TimeLineID *replayTLI)

References AbsorbSyncRequests(), ALLOCSET_DEFAULT_SIZES, AllocSetContextCreate, Assert, AtEOXact_Buffers(), AtEOXact_Files(), AtEOXact_HashTables(), AtEOXact_SMgr(), AuxiliaryProcessMainCommon(), B_CHECKPOINTER, before_shmem_exit(), CheckArchiveTimeout(), CHECKPOINT_CAUSE_TIME, CHECKPOINT_CAUSE_XLOG, CHECKPOINT_END_OF_RECOVERY, CheckpointerShmemStruct::checkpointer_pid, PROC_HDR::checkpointerLatch, CheckpointerShmem, CheckPointTimeout, CheckPointWarning, ckpt_active, ckpt_cached_elapsed, CheckpointerShmemStruct::ckpt_done, CheckpointerShmemStruct::ckpt_failed, CheckpointerShmemStruct::ckpt_flags, CheckpointerShmemStruct::ckpt_lck, ckpt_start_recptr, ckpt_start_time, CheckpointerShmemStruct::ckpt_started, ConditionVariableBroadcast(), ConditionVariableCancelSleep(), CreateCheckPoint(), CreateRestartPoint(), CheckpointerShmemStruct::done_cv, EmitErrorReport(), ereport, errhint(), errmsg_plural(), error_context_stack, FlushErrorState(), GetInsertRecPtr(), GetXLogReplayRecPtr(), HandleCheckpointerInterrupts(), HOLD_INTERRUPTS, last_checkpoint_time, last_xlog_switch_time, LOG, LWLockReleaseAll(), MemoryContextReset(), MemoryContextSwitchTo(), Min, MyBackendType, MyLatch, MyProc, MyProcPid, now(), PgStat_CheckpointerStats::num_requested, PgStat_CheckpointerStats::num_timed, PendingCheckpointerStats, PG_exception_stack, pg_usleep(), pgstat_before_server_shutdown(), pgstat_report_checkpointer(), pgstat_report_wait_end(), pgstat_report_wal(), pqsignal(), ProcGlobal, PGPROC::procLatch, procsignal_sigusr1_handler(), RecoveryInProgress(), ReleaseAuxProcessResources(), ReqCheckpointHandler(), ResetLatch(), PgStat_CheckpointerStats::restartpoints_performed, PgStat_CheckpointerStats::restartpoints_requested, PgStat_CheckpointerStats::restartpoints_timed, RESUME_INTERRUPTS, SIG_DFL, SIG_IGN, SIGALRM, SIGCHLD, SIGHUP, SignalHandlerForConfigReload(), SignalHandlerForShutdownRequest(), SIGPIPE, SIGUSR1, SIGUSR2, smgrdestroyall(), SpinLockAcquire, SpinLockRelease, CheckpointerShmemStruct::start_cv, TopMemoryContext, UnBlockSig, UnlockBuffers(), UpdateSharedMemoryConfig(), WaitLatch(), WL_EXIT_ON_PM_DEATH, WL_LATCH_SET, WL_TIMEOUT, and XLogArchiveTimeout.

◆ CheckpointerShmemInit()

void CheckpointerShmemInit ( void  )

Definition at line 898 of file checkpointer.c.

899 {
901  bool found;
902 
904  ShmemInitStruct("Checkpointer Data",
905  size,
906  &found);
907 
908  if (!found)
909  {
910  /*
911  * First time through, so initialize. Note that we zero the whole
912  * requests array; this is so that CompactCheckpointerRequestQueue can
913  * assume that any pad bytes in the request structs are zeroes.
914  */
920  }
921 }
#define MemSet(start, val, len)
Definition: c.h:1020
size_t Size
Definition: c.h:605
Size CheckpointerShmemSize(void)
Definition: checkpointer.c:879
void ConditionVariableInit(ConditionVariable *cv)
int NBuffers
Definition: globals.c:139
void * ShmemInitStruct(const char *name, Size size, bool *foundPtr)
Definition: shmem.c:387
static pg_noinline void Size size
Definition: slab.c:607
#define SpinLockInit(lock)
Definition: spin.h:60

References CheckpointerShmem, CheckpointerShmemSize(), CheckpointerShmemStruct::ckpt_lck, ConditionVariableInit(), CheckpointerShmemStruct::done_cv, CheckpointerShmemStruct::max_requests, MemSet, NBuffers, ShmemInitStruct(), size, SpinLockInit, and CheckpointerShmemStruct::start_cv.

Referenced by CreateOrAttachShmemStructs().

◆ CheckpointerShmemSize()

Size CheckpointerShmemSize ( void  )

Definition at line 879 of file checkpointer.c.

880 {
881  Size size;
882 
883  /*
884  * Currently, the size of the requests[] array is arbitrarily set equal to
885  * NBuffers. This may prove too large or small ...
886  */
887  size = offsetof(CheckpointerShmemStruct, requests);
889 
890  return size;
891 }
Size add_size(Size s1, Size s2)
Definition: shmem.c:493
Size mul_size(Size s1, Size s2)
Definition: shmem.c:510

References add_size(), mul_size(), NBuffers, and size.

Referenced by CalculateShmemSize(), and CheckpointerShmemInit().

◆ CheckpointWriteDelay()

void CheckpointWriteDelay ( int  flags,
double  progress 
)

Definition at line 711 of file checkpointer.c.

712 {
713  static int absorb_counter = WRITES_PER_ABSORB;
714 
715  /* Do nothing if checkpoint is being executed by non-checkpointer process */
716  if (!AmCheckpointerProcess())
717  return;
718 
719  /*
720  * Perform the usual duties and take a nap, unless we're behind schedule,
721  * in which case we just try to catch up as quickly as possible.
722  */
723  if (!(flags & CHECKPOINT_IMMEDIATE) &&
727  {
729  {
730  ConfigReloadPending = false;
732  /* update shmem copies of config variables */
734  }
735 
737  absorb_counter = WRITES_PER_ABSORB;
738 
740 
741  /* Report interim statistics to the cumulative stats system */
743 
744  /*
745  * This sleep used to be connected to bgwriter_delay, typically 200ms.
746  * That resulted in more frequent wakeups if not much work to do.
747  * Checkpointer and bgwriter are no longer related so take the Big
748  * Sleep.
749  */
751  100,
752  WAIT_EVENT_CHECKPOINT_WRITE_DELAY);
754  }
755  else if (--absorb_counter <= 0)
756  {
757  /*
758  * Absorb pending fsync requests after each WRITES_PER_ABSORB write
759  * operations even when we don't sleep, to prevent overflow of the
760  * fsync request queue.
761  */
763  absorb_counter = WRITES_PER_ABSORB;
764  }
765 
766  /* Check for barrier events. */
769 }
static bool ImmediateCheckpointRequested(void)
Definition: checkpointer.c:684
static bool IsCheckpointOnSchedule(double progress)
Definition: checkpointer.c:780
#define WRITES_PER_ABSORB
Definition: checkpointer.c:131
volatile sig_atomic_t ProcSignalBarrierPending
Definition: globals.c:38
@ PGC_SIGHUP
Definition: guc.h:71
void ProcessConfigFile(GucContext context)
volatile sig_atomic_t ShutdownRequestPending
Definition: interrupt.c:28
volatile sig_atomic_t ConfigReloadPending
Definition: interrupt.c:27
int progress
Definition: pgbench.c:261
void ProcessProcSignalBarrier(void)
Definition: procsignal.c:464
#define CHECKPOINT_IMMEDIATE
Definition: xlog.h:139

References AbsorbSyncRequests(), AmCheckpointerProcess, CheckArchiveTimeout(), CHECKPOINT_IMMEDIATE, ConfigReloadPending, ImmediateCheckpointRequested(), IsCheckpointOnSchedule(), MyLatch, PGC_SIGHUP, pgstat_report_checkpointer(), ProcessConfigFile(), ProcessProcSignalBarrier(), ProcSignalBarrierPending, progress, ResetLatch(), ShutdownRequestPending, UpdateSharedMemoryConfig(), WaitLatch(), WL_EXIT_ON_PM_DEATH, WL_LATCH_SET, WL_TIMEOUT, and WRITES_PER_ABSORB.

Referenced by BufferSync().

◆ CompactCheckpointerRequestQueue()

static bool CompactCheckpointerRequestQueue ( void  )
static

Definition at line 1154 of file checkpointer.c.

1155 {
1156  struct CheckpointerSlotMapping
1157  {
1158  CheckpointerRequest request;
1159  int slot;
1160  };
1161 
1162  int n,
1163  preserve_count;
1164  int num_skipped = 0;
1165  HASHCTL ctl;
1166  HTAB *htab;
1167  bool *skip_slot;
1168 
1169  /* must hold CheckpointerCommLock in exclusive mode */
1170  Assert(LWLockHeldByMe(CheckpointerCommLock));
1171 
1172  /* Initialize skip_slot array */
1173  skip_slot = palloc0(sizeof(bool) * CheckpointerShmem->num_requests);
1174 
1175  /* Initialize temporary hash table */
1176  ctl.keysize = sizeof(CheckpointerRequest);
1177  ctl.entrysize = sizeof(struct CheckpointerSlotMapping);
1178  ctl.hcxt = CurrentMemoryContext;
1179 
1180  htab = hash_create("CompactCheckpointerRequestQueue",
1182  &ctl,
1184 
1185  /*
1186  * The basic idea here is that a request can be skipped if it's followed
1187  * by a later, identical request. It might seem more sensible to work
1188  * backwards from the end of the queue and check whether a request is
1189  * *preceded* by an earlier, identical request, in the hopes of doing less
1190  * copying. But that might change the semantics, if there's an
1191  * intervening SYNC_FORGET_REQUEST or SYNC_FILTER_REQUEST, so we do it
1192  * this way. It would be possible to be even smarter if we made the code
1193  * below understand the specific semantics of such requests (it could blow
1194  * away preceding entries that would end up being canceled anyhow), but
1195  * it's not clear that the extra complexity would buy us anything.
1196  */
1197  for (n = 0; n < CheckpointerShmem->num_requests; n++)
1198  {
1199  CheckpointerRequest *request;
1200  struct CheckpointerSlotMapping *slotmap;
1201  bool found;
1202 
1203  /*
1204  * We use the request struct directly as a hashtable key. This
1205  * assumes that any padding bytes in the structs are consistently the
1206  * same, which should be okay because we zeroed them in
1207  * CheckpointerShmemInit. Note also that RelFileLocator had better
1208  * contain no pad bytes.
1209  */
1210  request = &CheckpointerShmem->requests[n];
1211  slotmap = hash_search(htab, request, HASH_ENTER, &found);
1212  if (found)
1213  {
1214  /* Duplicate, so mark the previous occurrence as skippable */
1215  skip_slot[slotmap->slot] = true;
1216  num_skipped++;
1217  }
1218  /* Remember slot containing latest occurrence of this request value */
1219  slotmap->slot = n;
1220  }
1221 
1222  /* Done with the hash table. */
1223  hash_destroy(htab);
1224 
1225  /* If no duplicates, we're out of luck. */
1226  if (!num_skipped)
1227  {
1228  pfree(skip_slot);
1229  return false;
1230  }
1231 
1232  /* We found some duplicates; remove them. */
1233  preserve_count = 0;
1234  for (n = 0; n < CheckpointerShmem->num_requests; n++)
1235  {
1236  if (skip_slot[n])
1237  continue;
1238  CheckpointerShmem->requests[preserve_count++] = CheckpointerShmem->requests[n];
1239  }
1240  ereport(DEBUG1,
1241  (errmsg_internal("compacted fsync request queue from %d entries to %d entries",
1242  CheckpointerShmem->num_requests, preserve_count)));
1243  CheckpointerShmem->num_requests = preserve_count;
1244 
1245  /* Cleanup. */
1246  pfree(skip_slot);
1247  return true;
1248 }
void hash_destroy(HTAB *hashp)
Definition: dynahash.c:865
void * hash_search(HTAB *hashp, const void *keyPtr, HASHACTION action, bool *foundPtr)
Definition: dynahash.c:955
HTAB * hash_create(const char *tabname, long nelem, const HASHCTL *info, int flags)
Definition: dynahash.c:352
int errmsg_internal(const char *fmt,...)
Definition: elog.c:1157
@ HASH_ENTER
Definition: hsearch.h:114
#define HASH_CONTEXT
Definition: hsearch.h:102
#define HASH_ELEM
Definition: hsearch.h:95
#define HASH_BLOBS
Definition: hsearch.h:97
bool LWLockHeldByMe(LWLock *lock)
Definition: lwlock.c:1895
void * palloc0(Size size)
Definition: mcxt.c:1346
MemoryContext CurrentMemoryContext
Definition: mcxt.c:143
tree ctl
Definition: radixtree.h:1851
Definition: dynahash.c:220

References Assert, CheckpointerShmem, ctl, CurrentMemoryContext, DEBUG1, ereport, errmsg_internal(), HASH_BLOBS, HASH_CONTEXT, hash_create(), hash_destroy(), HASH_ELEM, HASH_ENTER, hash_search(), LWLockHeldByMe(), CheckpointerShmemStruct::num_requests, palloc0(), pfree(), and CheckpointerShmemStruct::requests.

Referenced by ForwardSyncRequest().

◆ FirstCallSinceLastCheckpoint()

bool FirstCallSinceLastCheckpoint ( void  )

Definition at line 1326 of file checkpointer.c.

1327 {
1328  static int ckpt_done = 0;
1329  int new_done;
1330  bool FirstCall = false;
1331 
1333  new_done = CheckpointerShmem->ckpt_done;
1335 
1336  if (new_done != ckpt_done)
1337  FirstCall = true;
1338 
1339  ckpt_done = new_done;
1340 
1341  return FirstCall;
1342 }

References CheckpointerShmem, CheckpointerShmemStruct::ckpt_done, CheckpointerShmemStruct::ckpt_lck, SpinLockAcquire, and SpinLockRelease.

Referenced by BackgroundWriterMain().

◆ ForwardSyncRequest()

bool ForwardSyncRequest ( const FileTag ftag,
SyncRequestType  type 
)

Definition at line 1093 of file checkpointer.c.

1094 {
1095  CheckpointerRequest *request;
1096  bool too_full;
1097 
1098  if (!IsUnderPostmaster)
1099  return false; /* probably shouldn't even get here */
1100 
1101  if (AmCheckpointerProcess())
1102  elog(ERROR, "ForwardSyncRequest must not be called in checkpointer");
1103 
1104  LWLockAcquire(CheckpointerCommLock, LW_EXCLUSIVE);
1105 
1106  /*
1107  * If the checkpointer isn't running or the request queue is full, the
1108  * backend will have to perform its own fsync request. But before forcing
1109  * that to happen, we can try to compact the request queue.
1110  */
1111  if (CheckpointerShmem->checkpointer_pid == 0 ||
1114  {
1115  LWLockRelease(CheckpointerCommLock);
1116  return false;
1117  }
1118 
1119  /* OK, insert request */
1121  request->ftag = *ftag;
1122  request->type = type;
1123 
1124  /* If queue is more than half full, nudge the checkpointer to empty it */
1125  too_full = (CheckpointerShmem->num_requests >=
1127 
1128  LWLockRelease(CheckpointerCommLock);
1129 
1130  /* ... but not till after we release the lock */
1131  if (too_full && ProcGlobal->checkpointerLatch)
1133 
1134  return true;
1135 }
static bool CompactCheckpointerRequestQueue(void)
#define ERROR
Definition: elog.h:39
bool IsUnderPostmaster
Definition: globals.c:117
void SetLatch(Latch *latch)
Definition: latch.c:632
const char * type

References AmCheckpointerProcess, CheckpointerShmemStruct::checkpointer_pid, PROC_HDR::checkpointerLatch, CheckpointerShmem, CompactCheckpointerRequestQueue(), elog, ERROR, CheckpointerRequest::ftag, IsUnderPostmaster, LW_EXCLUSIVE, LWLockAcquire(), LWLockRelease(), CheckpointerShmemStruct::max_requests, CheckpointerShmemStruct::num_requests, ProcGlobal, CheckpointerShmemStruct::requests, SetLatch(), CheckpointerRequest::type, and type.

Referenced by RegisterSyncRequest().

◆ HandleCheckpointerInterrupts()

static void HandleCheckpointerInterrupts ( void  )
static

Definition at line 558 of file checkpointer.c.

559 {
562 
564  {
565  ConfigReloadPending = false;
567 
568  /*
569  * Checkpointer is the last process to shut down, so we ask it to hold
570  * the keys for a range of other tasks required most of which have
571  * nothing to do with checkpointing at all.
572  *
573  * For various reasons, some config values can change dynamically so
574  * the primary copy of them is held in shared memory to make sure all
575  * backends see the same value. We make Checkpointer responsible for
576  * updating the shared memory copy if the parameter setting changes
577  * because of SIGHUP.
578  */
580  }
582  {
583  /*
584  * From here on, elog(ERROR) should end with exit(1), not send control
585  * back to the sigsetjmp block above
586  */
587  ExitOnAnyError = true;
588 
589  /*
590  * Close down the database.
591  *
592  * Since ShutdownXLOG() creates restartpoint or checkpoint, and
593  * updates the statistics, increment the checkpoint request and flush
594  * out pending statistic.
595  */
597  ShutdownXLOG(0, 0);
599  pgstat_report_wal(true);
600 
601  /* Normal exit from the checkpointer is here */
602  proc_exit(0); /* done */
603  }
604 
605  /* Perform logging of memory contexts of this process */
608 }
volatile sig_atomic_t LogMemoryContextPending
Definition: globals.c:39
bool ExitOnAnyError
Definition: globals.c:120
void proc_exit(int code)
Definition: ipc.c:104
void ProcessLogMemoryContextInterrupt(void)
Definition: mcxt.c:1288
void ShutdownXLOG(int code, Datum arg)
Definition: xlog.c:6539

References ConfigReloadPending, ExitOnAnyError, LogMemoryContextPending, PgStat_CheckpointerStats::num_requested, PendingCheckpointerStats, PGC_SIGHUP, pgstat_report_checkpointer(), pgstat_report_wal(), proc_exit(), ProcessConfigFile(), ProcessLogMemoryContextInterrupt(), ProcessProcSignalBarrier(), ProcSignalBarrierPending, ShutdownRequestPending, ShutdownXLOG(), and UpdateSharedMemoryConfig().

Referenced by CheckpointerMain().

◆ ImmediateCheckpointRequested()

static bool ImmediateCheckpointRequested ( void  )
static

Definition at line 684 of file checkpointer.c.

685 {
687 
688  /*
689  * We don't need to acquire the ckpt_lck in this case because we're only
690  * looking at a single flag bit.
691  */
692  if (cps->ckpt_flags & CHECKPOINT_IMMEDIATE)
693  return true;
694  return false;
695 }

References CHECKPOINT_IMMEDIATE, CheckpointerShmem, and CheckpointerShmemStruct::ckpt_flags.

Referenced by CheckpointWriteDelay().

◆ IsCheckpointOnSchedule()

static bool IsCheckpointOnSchedule ( double  progress)
static

Definition at line 780 of file checkpointer.c.

781 {
782  XLogRecPtr recptr;
783  struct timeval now;
784  double elapsed_xlogs,
785  elapsed_time;
786 
788 
789  /* Scale progress according to checkpoint_completion_target. */
791 
792  /*
793  * Check against the cached value first. Only do the more expensive
794  * calculations once we reach the target previously calculated. Since
795  * neither time or WAL insert pointer moves backwards, a freshly
796  * calculated value can only be greater than or equal to the cached value.
797  */
799  return false;
800 
801  /*
802  * Check progress against WAL segments written and CheckPointSegments.
803  *
804  * We compare the current WAL insert location against the location
805  * computed before calling CreateCheckPoint. The code in XLogInsert that
806  * actually triggers a checkpoint when CheckPointSegments is exceeded
807  * compares against RedoRecPtr, so this is not completely accurate.
808  * However, it's good enough for our purposes, we're only calculating an
809  * estimate anyway.
810  *
811  * During recovery, we compare last replayed WAL record's location with
812  * the location computed before calling CreateRestartPoint. That maintains
813  * the same pacing as we have during checkpoints in normal operation, but
814  * we might exceed max_wal_size by a fair amount. That's because there can
815  * be a large gap between a checkpoint's redo-pointer and the checkpoint
816  * record itself, and we only start the restartpoint after we've seen the
817  * checkpoint record. (The gap is typically up to CheckPointSegments *
818  * checkpoint_completion_target where checkpoint_completion_target is the
819  * value that was in effect when the WAL was generated).
820  */
821  if (RecoveryInProgress())
822  recptr = GetXLogReplayRecPtr(NULL);
823  else
824  recptr = GetInsertRecPtr();
825  elapsed_xlogs = (((double) (recptr - ckpt_start_recptr)) /
827 
828  if (progress < elapsed_xlogs)
829  {
830  ckpt_cached_elapsed = elapsed_xlogs;
831  return false;
832  }
833 
834  /*
835  * Check progress against time elapsed and checkpoint_timeout.
836  */
837  gettimeofday(&now, NULL);
838  elapsed_time = ((double) ((pg_time_t) now.tv_sec - ckpt_start_time) +
839  now.tv_usec / 1000000.0) / CheckPointTimeout;
840 
841  if (progress < elapsed_time)
842  {
844  return false;
845  }
846 
847  /* It looks like we're on schedule. */
848  return true;
849 }
double CheckPointCompletionTarget
Definition: checkpointer.c:138
static double elapsed_time(instr_time *starttime)
Definition: explain.c:1272
int gettimeofday(struct timeval *tp, void *tzp)
int CheckPointSegments
Definition: xlog.c:156

References Assert, CheckPointCompletionTarget, CheckPointSegments, CheckPointTimeout, ckpt_active, ckpt_cached_elapsed, ckpt_start_recptr, ckpt_start_time, elapsed_time(), GetInsertRecPtr(), gettimeofday(), GetXLogReplayRecPtr(), now(), progress, RecoveryInProgress(), and wal_segment_size.

Referenced by CheckpointWriteDelay().

◆ ReqCheckpointHandler()

static void ReqCheckpointHandler ( SIGNAL_ARGS  )
static

Definition at line 859 of file checkpointer.c.

860 {
861  /*
862  * The signaling process should have set ckpt_flags nonzero, so all we
863  * need do is ensure that our main loop gets kicked out of any wait.
864  */
865  SetLatch(MyLatch);
866 }

References MyLatch, and SetLatch().

Referenced by CheckpointerMain().

◆ RequestCheckpoint()

void RequestCheckpoint ( int  flags)

Definition at line 941 of file checkpointer.c.

942 {
943  int ntries;
944  int old_failed,
945  old_started;
946 
947  /*
948  * If in a standalone backend, just do it ourselves.
949  */
951  {
952  /*
953  * There's no point in doing slow checkpoints in a standalone backend,
954  * because there's no other backends the checkpoint could disrupt.
955  */
957 
958  /* Free all smgr objects, as CheckpointerMain() normally would. */
959  smgrdestroyall();
960 
961  return;
962  }
963 
964  /*
965  * Atomically set the request flags, and take a snapshot of the counters.
966  * When we see ckpt_started > old_started, we know the flags we set here
967  * have been seen by checkpointer.
968  *
969  * Note that we OR the flags with any existing flags, to avoid overriding
970  * a "stronger" request by another backend. The flag senses must be
971  * chosen to make this work!
972  */
974 
975  old_failed = CheckpointerShmem->ckpt_failed;
976  old_started = CheckpointerShmem->ckpt_started;
978 
980 
981  /*
982  * Send signal to request checkpoint. It's possible that the checkpointer
983  * hasn't started yet, or is in process of restarting, so we will retry a
984  * few times if needed. (Actually, more than a few times, since on slow
985  * or overloaded buildfarm machines, it's been observed that the
986  * checkpointer can take several seconds to start.) However, if not told
987  * to wait for the checkpoint to occur, we consider failure to send the
988  * signal to be nonfatal and merely LOG it. The checkpointer should see
989  * the request when it does start, with or without getting a signal.
990  */
991 #define MAX_SIGNAL_TRIES 600 /* max wait 60.0 sec */
992  for (ntries = 0;; ntries++)
993  {
995  {
996  if (ntries >= MAX_SIGNAL_TRIES || !(flags & CHECKPOINT_WAIT))
997  {
998  elog((flags & CHECKPOINT_WAIT) ? ERROR : LOG,
999  "could not signal for checkpoint: checkpointer is not running");
1000  break;
1001  }
1002  }
1003  else if (kill(CheckpointerShmem->checkpointer_pid, SIGINT) != 0)
1004  {
1005  if (ntries >= MAX_SIGNAL_TRIES || !(flags & CHECKPOINT_WAIT))
1006  {
1007  elog((flags & CHECKPOINT_WAIT) ? ERROR : LOG,
1008  "could not signal for checkpoint: %m");
1009  break;
1010  }
1011  }
1012  else
1013  break; /* signal sent successfully */
1014 
1016  pg_usleep(100000L); /* wait 0.1 sec, then retry */
1017  }
1018 
1019  /*
1020  * If requested, wait for completion. We detect completion according to
1021  * the algorithm given above.
1022  */
1023  if (flags & CHECKPOINT_WAIT)
1024  {
1025  int new_started,
1026  new_failed;
1027 
1028  /* Wait for a new checkpoint to start. */
1030  for (;;)
1031  {
1033  new_started = CheckpointerShmem->ckpt_started;
1035 
1036  if (new_started != old_started)
1037  break;
1038 
1040  WAIT_EVENT_CHECKPOINT_START);
1041  }
1043 
1044  /*
1045  * We are waiting for ckpt_done >= new_started, in a modulo sense.
1046  */
1048  for (;;)
1049  {
1050  int new_done;
1051 
1053  new_done = CheckpointerShmem->ckpt_done;
1054  new_failed = CheckpointerShmem->ckpt_failed;
1056 
1057  if (new_done - new_started >= 0)
1058  break;
1059 
1061  WAIT_EVENT_CHECKPOINT_DONE);
1062  }
1064 
1065  if (new_failed != old_failed)
1066  ereport(ERROR,
1067  (errmsg("checkpoint request failed"),
1068  errhint("Consult recent messages in the server log for details.")));
1069  }
1070 }
#define MAX_SIGNAL_TRIES
void ConditionVariablePrepareToSleep(ConditionVariable *cv)
void ConditionVariableSleep(ConditionVariable *cv, uint32 wait_event_info)
int errmsg(const char *fmt,...)
Definition: elog.c:1070
bool IsPostmasterEnvironment
Definition: globals.c:116
#define CHECK_FOR_INTERRUPTS()
Definition: miscadmin.h:122
#define kill(pid, sig)
Definition: win32_port.h:485
#define CHECKPOINT_REQUESTED
Definition: xlog.h:144
#define CHECKPOINT_WAIT
Definition: xlog.h:143

References CHECK_FOR_INTERRUPTS, CHECKPOINT_IMMEDIATE, CHECKPOINT_REQUESTED, CHECKPOINT_WAIT, CheckpointerShmemStruct::checkpointer_pid, CheckpointerShmem, CheckpointerShmemStruct::ckpt_done, CheckpointerShmemStruct::ckpt_failed, CheckpointerShmemStruct::ckpt_flags, CheckpointerShmemStruct::ckpt_lck, CheckpointerShmemStruct::ckpt_started, ConditionVariableCancelSleep(), ConditionVariablePrepareToSleep(), ConditionVariableSleep(), CreateCheckPoint(), CheckpointerShmemStruct::done_cv, elog, ereport, errhint(), errmsg(), ERROR, IsPostmasterEnvironment, kill, LOG, MAX_SIGNAL_TRIES, pg_usleep(), smgrdestroyall(), SpinLockAcquire, SpinLockRelease, and CheckpointerShmemStruct::start_cv.

Referenced by CreateDatabaseUsingFileCopy(), do_pg_backup_start(), dropdb(), DropTableSpace(), movedb(), PerformRecoveryXLogAction(), standard_ProcessUtility(), StartupXLOG(), XLogPageRead(), and XLogWrite().

◆ UpdateSharedMemoryConfig()

static void UpdateSharedMemoryConfig ( void  )
static

Definition at line 1307 of file checkpointer.c.

1308 {
1309  /* update global shmem state for sync rep */
1311 
1312  /*
1313  * If full_page_writes has been changed by SIGHUP, we update it in shared
1314  * memory and write an XLOG_FPW_CHANGE record.
1315  */
1317 
1318  elog(DEBUG2, "checkpointer updated shared memory configuration values");
1319 }
#define DEBUG2
Definition: elog.h:29
void SyncRepUpdateSyncStandbysDefined(void)
Definition: syncrep.c:921
void UpdateFullPageWrites(void)
Definition: xlog.c:8087

References DEBUG2, elog, SyncRepUpdateSyncStandbysDefined(), and UpdateFullPageWrites().

Referenced by CheckpointerMain(), CheckpointWriteDelay(), and HandleCheckpointerInterrupts().

Variable Documentation

◆ CheckPointCompletionTarget

double CheckPointCompletionTarget = 0.9

◆ CheckpointerShmem

◆ CheckPointTimeout

int CheckPointTimeout = 300

Definition at line 136 of file checkpointer.c.

Referenced by CheckpointerMain(), and IsCheckpointOnSchedule().

◆ CheckPointWarning

int CheckPointWarning = 30

Definition at line 137 of file checkpointer.c.

Referenced by CheckpointerMain().

◆ ckpt_active

bool ckpt_active = false
static

Definition at line 143 of file checkpointer.c.

Referenced by CheckpointerMain(), and IsCheckpointOnSchedule().

◆ ckpt_cached_elapsed

double ckpt_cached_elapsed
static

Definition at line 148 of file checkpointer.c.

Referenced by CheckpointerMain(), and IsCheckpointOnSchedule().

◆ ckpt_start_recptr

XLogRecPtr ckpt_start_recptr
static

Definition at line 147 of file checkpointer.c.

Referenced by CheckpointerMain(), and IsCheckpointOnSchedule().

◆ ckpt_start_time

pg_time_t ckpt_start_time
static

Definition at line 146 of file checkpointer.c.

Referenced by CheckpointerMain(), and IsCheckpointOnSchedule().

◆ last_checkpoint_time

pg_time_t last_checkpoint_time
static

Definition at line 150 of file checkpointer.c.

Referenced by CheckpointerMain().

◆ last_xlog_switch_time

pg_time_t last_xlog_switch_time
static

Definition at line 151 of file checkpointer.c.

Referenced by CheckArchiveTimeout(), and CheckpointerMain().