#include "postgres.h"
#include "utils/pgstat_internal.h"
#include "executor/instrument.h"

Include dependency graph for pgstat_wal.c:

Macros
#define	WALSTAT_ACC(fld, var_to_add) (stats_shmem->stats.fld += var_to_add.fld)

#define	WALSTAT_ACC_INSTR_TIME(fld) (stats_shmem->stats.fld += INSTR_TIME_GET_MICROSEC(PendingWalStats.fld))

Functions
void	pgstat_report_wal (bool force)

PgStat_WalStats *	pgstat_fetch_stat_wal (void)

bool	pgstat_flush_wal (bool nowait)

void	pgstat_init_wal (void)

bool	pgstat_have_pending_wal (void)

void	pgstat_wal_reset_all_cb (TimestampTz ts)

void	pgstat_wal_snapshot_cb (void)

Variables
PgStat_PendingWalStats	PendingWalStats = {0}

static WalUsage	prevWalUsage

Macro Definition Documentation

◆ WALSTAT_ACC

#define WALSTAT_ACC	(	fld,
		var_to_add
	)	(stats_shmem->stats.fld += var_to_add.fld)

◆ WALSTAT_ACC_INSTR_TIME

#define WALSTAT_ACC_INSTR_TIME ( fld ) (stats_shmem->stats.fld += INSTR_TIME_GET_MICROSEC(PendingWalStats.fld))

Function Documentation

◆ pgstat_fetch_stat_wal()

PgStat_WalStats* pgstat_fetch_stat_wal ( void )

Definition at line 67 of file pgstat_wal.c.

 {
     pgstat_snapshot_fixed(PGSTAT_KIND_WAL);
  
     return &pgStatLocal.snapshot.wal;
 }

References PGSTAT_KIND_WAL, pgstat_snapshot_fixed(), pgStatLocal, PgStat_LocalState::snapshot, and PgStat_Snapshot::wal.

Referenced by pg_stat_get_wal().

◆ pgstat_flush_wal()

bool pgstat_flush_wal ( bool nowait )

Definition at line 82 of file pgstat_wal.c.

 {
     PgStatShared_Wal *stats_shmem = &pgStatLocal.shmem->wal;
     WalUsage    wal_usage_diff = {0};
  
     Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
     Assert(pgStatLocal.shmem != NULL &&
            !pgStatLocal.shmem->is_shutdown);
  
     /*
      * This function can be called even if nothing at all has happened. Avoid
      * taking lock for nothing in that case.
      */
     if (!pgstat_have_pending_wal())
         return false;
  
     /*
      * We don't update the WAL usage portion of the local WalStats elsewhere.
      * Calculate how much WAL usage counters were increased by subtracting the
      * previous counters from the current ones.
      */
     WalUsageAccumDiff(&wal_usage_diff, &pgWalUsage, &prevWalUsage);
  
     if (!nowait)
         LWLockAcquire(&stats_shmem->lock, LW_EXCLUSIVE);
     else if (!LWLockConditionalAcquire(&stats_shmem->lock, LW_EXCLUSIVE))
         return true;
  
 #define WALSTAT_ACC(fld, var_to_add) \
     (stats_shmem->stats.fld += var_to_add.fld)
 #define WALSTAT_ACC_INSTR_TIME(fld) \
     (stats_shmem->stats.fld += INSTR_TIME_GET_MICROSEC(PendingWalStats.fld))
     WALSTAT_ACC(wal_records, wal_usage_diff);
     WALSTAT_ACC(wal_fpi, wal_usage_diff);
     WALSTAT_ACC(wal_bytes, wal_usage_diff);
     WALSTAT_ACC(wal_buffers_full, PendingWalStats);
     WALSTAT_ACC(wal_write, PendingWalStats);
     WALSTAT_ACC(wal_sync, PendingWalStats);
     WALSTAT_ACC_INSTR_TIME(wal_write_time);
     WALSTAT_ACC_INSTR_TIME(wal_sync_time);
 #undef WALSTAT_ACC_INSTR_TIME
 #undef WALSTAT_ACC
  
     LWLockRelease(&stats_shmem->lock);
  
     /*
      * Save the current counters for the subsequent calculation of WAL usage.
      */
     prevWalUsage = pgWalUsage;
  
     /*
      * Clear out the statistics buffer, so it can be re-used.
      */
     MemSet(&PendingWalStats, 0, sizeof(PendingWalStats));
  
     return false;
 }

References Assert(), PgStat_ShmemControl::is_shutdown, IsPostmasterEnvironment, IsUnderPostmaster, PgStatShared_Wal::lock, LW_EXCLUSIVE, LWLockAcquire(), LWLockConditionalAcquire(), LWLockRelease(), MemSet, PendingWalStats, pgstat_have_pending_wal(), pgStatLocal, pgWalUsage, prevWalUsage, PgStat_LocalState::shmem, PgStat_ShmemControl::wal, WALSTAT_ACC, WALSTAT_ACC_INSTR_TIME, and WalUsageAccumDiff().

Referenced by pgstat_report_stat(), and pgstat_report_wal().

◆ pgstat_have_pending_wal()

bool pgstat_have_pending_wal ( void )

Definition at line 159 of file pgstat_wal.c.

 {
     return pgWalUsage.wal_records != prevWalUsage.wal_records ||
         PendingWalStats.wal_write != 0 ||
         PendingWalStats.wal_sync != 0;
 }

References PendingWalStats, pgWalUsage, prevWalUsage, WalUsage::wal_records, PgStat_PendingWalStats::wal_sync, and PgStat_PendingWalStats::wal_write.

Referenced by pgstat_flush_wal(), and pgstat_report_stat().

◆ pgstat_init_wal()

void pgstat_init_wal ( void )

Definition at line 141 of file pgstat_wal.c.

 {
     /*
      * Initialize prevWalUsage with pgWalUsage so that pgstat_flush_wal() can
      * calculate how much pgWalUsage counters are increased by subtracting
      * prevWalUsage from pgWalUsage.
      */
     prevWalUsage = pgWalUsage;
 }

References pgWalUsage, and prevWalUsage.

Referenced by pgstat_initialize().

◆ pgstat_report_wal()

void pgstat_report_wal ( bool force )

Definition at line 48 of file pgstat_wal.c.

 {
     bool        nowait;
  
     /* like in pgstat.c, don't wait for lock acquisition when !force */
     nowait = !force;
  
     /* flush wal stats */
     pgstat_flush_wal(nowait);
  
     /* flush IO stats */
     pgstat_flush_io(nowait);
 }

References pgstat_flush_io(), and pgstat_flush_wal().

Referenced by BackgroundWriterMain(), CheckpointerMain(), HandleCheckpointerInterrupts(), and WalWriterMain().

◆ pgstat_wal_reset_all_cb()

void pgstat_wal_reset_all_cb ( TimestampTz ts )

Definition at line 167 of file pgstat_wal.c.

 {
     PgStatShared_Wal *stats_shmem = &pgStatLocal.shmem->wal;
  
     LWLockAcquire(&stats_shmem->lock, LW_EXCLUSIVE);
     memset(&stats_shmem->stats, 0, sizeof(stats_shmem->stats));
     stats_shmem->stats.stat_reset_timestamp = ts;
     LWLockRelease(&stats_shmem->lock);
 }

References PgStatShared_Wal::lock, LW_EXCLUSIVE, LWLockAcquire(), LWLockRelease(), pgStatLocal, PgStat_LocalState::shmem, PgStat_WalStats::stat_reset_timestamp, PgStatShared_Wal::stats, and PgStat_ShmemControl::wal.

◆ pgstat_wal_snapshot_cb()

void pgstat_wal_snapshot_cb ( void )

Definition at line 178 of file pgstat_wal.c.

 {
     PgStatShared_Wal *stats_shmem = &pgStatLocal.shmem->wal;
  
     LWLockAcquire(&stats_shmem->lock, LW_SHARED);
     memcpy(&pgStatLocal.snapshot.wal, &stats_shmem->stats,
            sizeof(pgStatLocal.snapshot.wal));
     LWLockRelease(&stats_shmem->lock);
 }

References PgStatShared_Wal::lock, LW_SHARED, LWLockAcquire(), LWLockRelease(), pgStatLocal, PgStat_LocalState::shmem, PgStat_LocalState::snapshot, PgStatShared_Wal::stats, PgStat_ShmemControl::wal, and PgStat_Snapshot::wal.

Variable Documentation

◆ PendingWalStats

PgStat_PendingWalStats PendingWalStats = {0}

Definition at line 24 of file pgstat_wal.c.

Referenced by AdvanceXLInsertBuffer(), issue_xlog_fsync(), pgstat_flush_wal(), pgstat_have_pending_wal(), and XLogWrite().

◆ prevWalUsage

WalUsage prevWalUsage

static

Definition at line 32 of file pgstat_wal.c.

Referenced by pgstat_flush_wal(), pgstat_have_pending_wal(), and pgstat_init_wal().

Macros

Functions

Variables