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pgstat_checkpointer.c
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1 /* -------------------------------------------------------------------------
2  *
3  * pgstat_checkpointer.c
4  * Implementation of checkpoint statistics.
5  *
6  * This file contains the implementation of checkpoint statistics. It is kept
7  * separate from pgstat.c to enforce the line between the statistics access /
8  * storage implementation and the details about individual types of
9  * statistics.
10  *
11  * Copyright (c) 2001-2022, PostgreSQL Global Development Group
12  *
13  * IDENTIFICATION
14  * src/backend/utils/activity/pgstat_checkpointer.c
15  * -------------------------------------------------------------------------
16  */
17 
18 #include "postgres.h"
19 
20 #include "utils/pgstat_internal.h"
21 
22 
24 
25 
26 /*
27  * Report checkpointer statistics
28  */
29 void
31 {
32  /* We assume this initializes to zeroes */
33  static const PgStat_CheckpointerStats all_zeroes;
35 
38 
39  /*
40  * This function can be called even if nothing at all has happened. In
41  * this case, avoid unnecessarily modifying the stats entry.
42  */
43  if (memcmp(&PendingCheckpointerStats, &all_zeroes,
44  sizeof(all_zeroes)) == 0)
45  return;
46 
48 
49 #define CHECKPOINTER_ACC(fld) stats_shmem->stats.fld += PendingCheckpointerStats.fld
50  CHECKPOINTER_ACC(timed_checkpoints);
51  CHECKPOINTER_ACC(requested_checkpoints);
52  CHECKPOINTER_ACC(checkpoint_write_time);
53  CHECKPOINTER_ACC(checkpoint_sync_time);
54  CHECKPOINTER_ACC(buf_written_checkpoints);
55  CHECKPOINTER_ACC(buf_written_backend);
56  CHECKPOINTER_ACC(buf_fsync_backend);
57 #undef CHECKPOINTER_ACC
58 
60 
61  /*
62  * Clear out the statistics buffer, so it can be re-used.
63  */
65 }
66 
67 /*
68  * pgstat_fetch_stat_checkpointer() -
69  *
70  * Support function for the SQL-callable pgstat* functions. Returns
71  * a pointer to the checkpointer statistics struct.
72  */
75 {
77 
79 }
80 
81 void
83 {
85 
86  /* see explanation above PgStatShared_Checkpointer for the reset protocol */
87  LWLockAcquire(&stats_shmem->lock, LW_EXCLUSIVE);
89  &stats_shmem->stats,
90  sizeof(stats_shmem->stats),
91  &stats_shmem->changecount);
92  LWLockRelease(&stats_shmem->lock);
93 }
94 
95 void
97 {
99  PgStat_CheckpointerStats *reset_offset = &stats_shmem->reset_offset;
101 
103  &stats_shmem->stats,
104  sizeof(stats_shmem->stats),
105  &stats_shmem->changecount);
106 
107  LWLockAcquire(&stats_shmem->lock, LW_SHARED);
108  memcpy(&reset, reset_offset, sizeof(stats_shmem->stats));
109  LWLockRelease(&stats_shmem->lock);
110 
111  /* compensate by reset offsets */
112 #define CHECKPOINTER_COMP(fld) pgStatLocal.snapshot.checkpointer.fld -= reset.fld;
113  CHECKPOINTER_COMP(timed_checkpoints);
114  CHECKPOINTER_COMP(requested_checkpoints);
115  CHECKPOINTER_COMP(checkpoint_write_time);
116  CHECKPOINTER_COMP(checkpoint_sync_time);
117  CHECKPOINTER_COMP(buf_written_checkpoints);
118  CHECKPOINTER_COMP(buf_written_backend);
119  CHECKPOINTER_COMP(buf_fsync_backend);
120 #undef CHECKPOINTER_COMP
121 }
#define MemSet(start, val, len)
Definition: c.h:1008
int64 TimestampTz
Definition: timestamp.h:39
Assert(fmt[strlen(fmt) - 1] !='\n')
bool LWLockAcquire(LWLock *lock, LWLockMode mode)
Definition: lwlock.c:1196
void LWLockRelease(LWLock *lock)
Definition: lwlock.c:1800
@ LW_SHARED
Definition: lwlock.h:105
@ LW_EXCLUSIVE
Definition: lwlock.h:104
void pgstat_snapshot_fixed(PgStat_Kind kind)
Definition: pgstat.c:899
PgStat_LocalState pgStatLocal
Definition: pgstat.c:195
@ PGSTAT_KIND_CHECKPOINTER
Definition: pgstat.h:50
void pgstat_checkpointer_snapshot_cb(void)
#define CHECKPOINTER_COMP(fld)
void pgstat_report_checkpointer(void)
void pgstat_checkpointer_reset_all_cb(TimestampTz ts)
PgStat_CheckpointerStats PendingCheckpointerStats
PgStat_CheckpointerStats * pgstat_fetch_stat_checkpointer(void)
#define CHECKPOINTER_ACC(fld)
static void pgstat_end_changecount_write(uint32 *cc)
#define pgstat_assert_is_up()
static void pgstat_begin_changecount_write(uint32 *cc)
static void pgstat_copy_changecounted_stats(void *dst, void *src, size_t len, uint32 *cc)
void reset(void)
Definition: sql-declare.c:600
PgStat_CheckpointerStats reset_offset
PgStat_CheckpointerStats stats
PgStat_Snapshot snapshot
PgStat_ShmemControl * shmem
PgStatShared_Checkpointer checkpointer
PgStat_CheckpointerStats checkpointer