diff options
Diffstat (limited to 'src/backend/utils/activity/pgstat_bgwriter.c')
| -rw-r--r-- | src/backend/utils/activity/pgstat_bgwriter.c | 82 |
1 files changed, 66 insertions, 16 deletions
diff --git a/src/backend/utils/activity/pgstat_bgwriter.c b/src/backend/utils/activity/pgstat_bgwriter.c index dfea88eca10..fbb1edc5275 100644 --- a/src/backend/utils/activity/pgstat_bgwriter.c +++ b/src/backend/utils/activity/pgstat_bgwriter.c @@ -20,12 +20,7 @@ #include "utils/pgstat_internal.h" -/* - * BgWriter global statistics counters. Stored directly in a stats - * message structure so they can be sent without needing to copy things - * around. We assume this init to zeroes. - */ -PgStat_MsgBgWriter PendingBgWriterStats; +PgStat_BgWriterStats PendingBgWriterStats = {0}; /* @@ -34,27 +29,82 @@ PgStat_MsgBgWriter PendingBgWriterStats; void pgstat_report_bgwriter(void) { - /* We assume this initializes to zeroes */ - static const PgStat_MsgBgWriter all_zeroes; + PgStatShared_BgWriter *stats_shmem = &pgStatLocal.shmem->bgwriter; + static const PgStat_BgWriterStats all_zeroes; + Assert(!pgStatLocal.shmem->is_shutdown); pgstat_assert_is_up(); /* * This function can be called even if nothing at all has happened. In - * this case, avoid sending a completely empty message to the stats - * collector. + * this case, avoid unnecessarily modifying the stats entry. */ - if (memcmp(&PendingBgWriterStats, &all_zeroes, sizeof(PgStat_MsgBgWriter)) == 0) + if (memcmp(&PendingBgWriterStats, &all_zeroes, sizeof(all_zeroes)) == 0) return; - /* - * Prepare and send the message - */ - pgstat_setheader(&PendingBgWriterStats.m_hdr, PGSTAT_MTYPE_BGWRITER); - pgstat_send(&PendingBgWriterStats, sizeof(PendingBgWriterStats)); + pgstat_begin_changecount_write(&stats_shmem->changecount); + +#define BGWRITER_ACC(fld) stats_shmem->stats.fld += PendingBgWriterStats.fld + BGWRITER_ACC(buf_written_clean); + BGWRITER_ACC(maxwritten_clean); + BGWRITER_ACC(buf_alloc); +#undef BGWRITER_ACC + + pgstat_end_changecount_write(&stats_shmem->changecount); /* * Clear out the statistics buffer, so it can be re-used. */ MemSet(&PendingBgWriterStats, 0, sizeof(PendingBgWriterStats)); } + +/* + * Support function for the SQL-callable pgstat* functions. Returns + * a pointer to the bgwriter statistics struct. + */ +PgStat_BgWriterStats * +pgstat_fetch_stat_bgwriter(void) +{ + pgstat_snapshot_fixed(PGSTAT_KIND_BGWRITER); + + return &pgStatLocal.snapshot.bgwriter; +} + +void +pgstat_bgwriter_reset_all_cb(TimestampTz ts) +{ + PgStatShared_BgWriter *stats_shmem = &pgStatLocal.shmem->bgwriter; + + /* see explanation above PgStatShared_BgWriter for the reset protocol */ + LWLockAcquire(&stats_shmem->lock, LW_EXCLUSIVE); + pgstat_copy_changecounted_stats(&stats_shmem->reset_offset, + &stats_shmem->stats, + sizeof(stats_shmem->stats), + &stats_shmem->changecount); + stats_shmem->stats.stat_reset_timestamp = ts; + LWLockRelease(&stats_shmem->lock); +} + +void +pgstat_bgwriter_snapshot_cb(void) +{ + PgStatShared_BgWriter *stats_shmem = &pgStatLocal.shmem->bgwriter; + PgStat_BgWriterStats *reset_offset = &stats_shmem->reset_offset; + PgStat_BgWriterStats reset; + + pgstat_copy_changecounted_stats(&pgStatLocal.snapshot.bgwriter, + &stats_shmem->stats, + sizeof(stats_shmem->stats), + &stats_shmem->changecount); + + LWLockAcquire(&stats_shmem->lock, LW_SHARED); + memcpy(&reset, reset_offset, sizeof(stats_shmem->stats)); + LWLockRelease(&stats_shmem->lock); + + /* compensate by reset offsets */ +#define BGWRITER_COMP(fld) pgStatLocal.snapshot.bgwriter.fld -= reset.fld; + BGWRITER_COMP(buf_written_clean); + BGWRITER_COMP(maxwritten_clean); + BGWRITER_COMP(buf_alloc); +#undef BGWRITER_COMP +} |