pgstat.c File Reference

#include "postgres.h"
#include <unistd.h>
#include "access/transam.h"
#include "access/xact.h"
#include "lib/dshash.h"
#include "pgstat.h"
#include "port/atomics.h"
#include "storage/fd.h"
#include "storage/ipc.h"
#include "storage/lwlock.h"
#include "storage/pg_shmem.h"
#include "storage/shmem.h"
#include "utils/guc_hooks.h"
#include "utils/memutils.h"
#include "utils/pgstat_internal.h"
#include "utils/timestamp.h"
#include "lib/simplehash.h"

Include dependency graph for pgstat.c:

Go to the source code of this file.

Data Structures
struct	PgStat_SnapshotEntry

Macros
#define	PGSTAT_MIN_INTERVAL   1000
#define	PGSTAT_MAX_INTERVAL   60000
#define	PGSTAT_IDLE_INTERVAL   10000
#define	PGSTAT_SNAPSHOT_HASH_SIZE   512
#define	SH_PREFIX   pgstat_snapshot
#define	SH_ELEMENT_TYPE   PgStat_SnapshotEntry
#define	SH_KEY_TYPE   PgStat_HashKey
#define	SH_KEY   key
#define	SH_HASH_KEY(tb, key)    pgstat_hash_hash_key(&key, sizeof(PgStat_HashKey), NULL)
#define	SH_EQUAL(tb, a, b)    pgstat_cmp_hash_key(&a, &b, sizeof(PgStat_HashKey), NULL) == 0
#define	SH_SCOPE   static inline
#define	SH_DEFINE
#define	SH_DECLARE
#define	write_chunk_s(fpout, ptr)   write_chunk(fpout, ptr, sizeof(*ptr))
#define	read_chunk_s(fpin, ptr)   read_chunk(fpin, ptr, sizeof(*ptr))

Typedefs
typedef struct PgStat_SnapshotEntry	PgStat_SnapshotEntry

Functions
static void	pgstat_write_statsfile (void)
static void	pgstat_read_statsfile (void)
static void	pgstat_reset_after_failure (void)
static bool	pgstat_flush_pending_entries (bool nowait)
static void	pgstat_prep_snapshot (void)
static void	pgstat_build_snapshot (void)
static void	pgstat_build_snapshot_fixed (PgStat_Kind kind)
static bool	pgstat_is_kind_valid (int ikind)
void	pgstat_restore_stats (void)
void	pgstat_discard_stats (void)
void	pgstat_before_server_shutdown (int code, Datum arg)
static void	pgstat_shutdown_hook (int code, Datum arg)
void	pgstat_initialize (void)
long	pgstat_report_stat (bool force)
void	pgstat_force_next_flush (void)
static bool	match_db_entries (PgStatShared_HashEntry *entry, Datum match_data)
void	pgstat_reset_counters (void)
void	pgstat_reset (PgStat_Kind kind, Oid dboid, Oid objoid)
void	pgstat_reset_of_kind (PgStat_Kind kind)
void	pgstat_clear_snapshot (void)
void *	pgstat_fetch_entry (PgStat_Kind kind, Oid dboid, Oid objoid)
TimestampTz	pgstat_get_stat_snapshot_timestamp (bool *have_snapshot)
bool	pgstat_have_entry (PgStat_Kind kind, Oid dboid, Oid objoid)
void	pgstat_snapshot_fixed (PgStat_Kind kind)
PgStat_EntryRef *	pgstat_prep_pending_entry (PgStat_Kind kind, Oid dboid, Oid objoid, bool *created_entry)
PgStat_EntryRef *	pgstat_fetch_pending_entry (PgStat_Kind kind, Oid dboid, Oid objoid)
void	pgstat_delete_pending_entry (PgStat_EntryRef *entry_ref)
PgStat_Kind	pgstat_get_kind_from_str (char *kind_str)
const PgStat_KindInfo *	pgstat_get_kind_info (PgStat_Kind kind)
static void	write_chunk (FILE *fpout, void *ptr, size_t len)
static bool	read_chunk (FILE *fpin, void *ptr, size_t len)
void	assign_stats_fetch_consistency (int newval, void *extra)

Variables
bool	pgstat_track_counts = false
int	pgstat_fetch_consistency = PGSTAT_FETCH_CONSISTENCY_CACHE
PgStat_LocalState	pgStatLocal
static MemoryContext	pgStatPendingContext = NULL
static dlist_head	pgStatPending = DLIST_STATIC_INIT(pgStatPending)
static bool	pgStatForceNextFlush = false
static bool	force_stats_snapshot_clear = false
static const PgStat_KindInfo	pgstat_kind_infos [PGSTAT_NUM_KINDS]

Macro Definition Documentation

PGSTAT_IDLE_INTERVAL

#define PGSTAT_IDLE_INTERVAL   10000

Definition at line 124 of file pgstat.c.

PGSTAT_MAX_INTERVAL

#define PGSTAT_MAX_INTERVAL   60000

Definition at line 122 of file pgstat.c.

PGSTAT_MIN_INTERVAL

#define PGSTAT_MIN_INTERVAL   1000

Definition at line 120 of file pgstat.c.

PGSTAT_SNAPSHOT_HASH_SIZE

#define PGSTAT_SNAPSHOT_HASH_SIZE   512

Definition at line 131 of file pgstat.c.

read_chunk_s

#define read_chunk_s	(		fpin,
			ptr
	)		read_chunk(fpin, ptr, sizeof(*ptr))

Definition at line 1474 of file pgstat.c.

SH_DECLARE

#define SH_DECLARE

Definition at line 159 of file pgstat.c.

SH_DEFINE

#define SH_DEFINE

Definition at line 158 of file pgstat.c.

SH_ELEMENT_TYPE

#define SH_ELEMENT_TYPE   PgStat_SnapshotEntry

Definition at line 150 of file pgstat.c.

SH_EQUAL

#define SH_EQUAL	(		tb,
			a,
			b
	)		pgstat_cmp_hash_key(&a, &b, sizeof(PgStat_HashKey), NULL) == 0

Definition at line 155 of file pgstat.c.

SH_HASH_KEY

#define SH_HASH_KEY	(		tb,
			key
	)		pgstat_hash_hash_key(&key, sizeof(PgStat_HashKey), NULL)

Definition at line 153 of file pgstat.c.

SH_KEY

#define SH_KEY   key

Definition at line 152 of file pgstat.c.

SH_KEY_TYPE

#define SH_KEY_TYPE   PgStat_HashKey

Definition at line 151 of file pgstat.c.

SH_PREFIX

#define SH_PREFIX   pgstat_snapshot

Definition at line 149 of file pgstat.c.

SH_SCOPE

#define SH_SCOPE   static inline

Definition at line 157 of file pgstat.c.

write_chunk_s

#define write_chunk_s	(		fpout,
			ptr
	)		write_chunk(fpout, ptr, sizeof(*ptr))

Definition at line 1301 of file pgstat.c.

Typedef Documentation

PgStat_SnapshotEntry

typedef struct PgStat_SnapshotEntry PgStat_SnapshotEntry

Function Documentation

assign_stats_fetch_consistency()

void assign_stats_fetch_consistency	(	int	newval,
		void *	extra
	)

Definition at line 1707 of file pgstat.c.

{
    /*
     * Changing this value in a transaction may cause snapshot state
     * inconsistencies, so force a clear of the current snapshot on the next
     * snapshot build attempt.
     */
    if (pgstat_fetch_consistency != newval)
        force_stats_snapshot_clear = true;
}

References force_stats_snapshot_clear, newval, and pgstat_fetch_consistency.

match_db_entries()

static bool match_db_entries ( PgStatShared_HashEntry *  entry, Datum  match_data  )

static

Definition at line 706 of file pgstat.c.

{
    return entry->key.dboid == DatumGetObjectId(MyDatabaseId);
}

References DatumGetObjectId(), PgStat_HashKey::dboid, PgStatShared_HashEntry::key, and MyDatabaseId.

Referenced by pgstat_reset_counters().

pgstat_before_server_shutdown()

void pgstat_before_server_shutdown	(	int	code,
		Datum	arg
	)

Definition at line 465 of file pgstat.c.

{
    Assert(pgStatLocal.shmem != NULL);
    Assert(!pgStatLocal.shmem->is_shutdown);
 
    /*
     * Stats should only be reported after pgstat_initialize() and before
     * pgstat_shutdown(). This is a convenient point to catch most violations
     * of this rule.
     */
    Assert(pgstat_is_initialized && !pgstat_is_shutdown);
 
    /* flush out our own pending changes before writing out */
    pgstat_report_stat(true);
 
    /*
     * Only write out file during normal shutdown. Don't even signal that
     * we've shutdown during irregular shutdowns, because the shutdown
     * sequence isn't coordinated to ensure this backend shuts down last.
     */
    if (code == 0)
    {
        pgStatLocal.shmem->is_shutdown = true;
        pgstat_write_statsfile();
    }
}

References Assert(), PgStat_ShmemControl::is_shutdown, pgstat_report_stat(), pgstat_write_statsfile(), pgStatLocal, and PgStat_LocalState::shmem.

Referenced by CheckpointerMain(), and InitPostgres().

pgstat_build_snapshot()

static void pgstat_build_snapshot ( void  )

static

Definition at line 976 of file pgstat.c.

{
    dshash_seq_status hstat;
    PgStatShared_HashEntry *p;
 
    /* should only be called when we need a snapshot */
    Assert(pgstat_fetch_consistency == PGSTAT_FETCH_CONSISTENCY_SNAPSHOT);
 
    /* snapshot already built */
    if (pgStatLocal.snapshot.mode == PGSTAT_FETCH_CONSISTENCY_SNAPSHOT)
        return;
 
    pgstat_prep_snapshot();
 
    Assert(pgStatLocal.snapshot.stats->members == 0);
 
    pgStatLocal.snapshot.snapshot_timestamp = GetCurrentTimestamp();
 
    /*
     * Snapshot all variable stats.
     */
    dshash_seq_init(&hstat, pgStatLocal.shared_hash, false);
    while ((p = dshash_seq_next(&hstat)) != NULL)
    {
        PgStat_Kind kind = p->key.kind;
        const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
        bool        found;
        PgStat_SnapshotEntry *entry;
        PgStatShared_Common *stats_data;
 
        /*
         * Check if the stats object should be included in the snapshot.
         * Unless the stats kind can be accessed from all databases (e.g.,
         * database stats themselves), we only include stats for the current
         * database or objects not associated with a database (e.g. shared
         * relations).
         */
        if (p->key.dboid != MyDatabaseId &&
            p->key.dboid != InvalidOid &&
            !kind_info->accessed_across_databases)
            continue;
 
        if (p->dropped)
            continue;
 
        Assert(pg_atomic_read_u32(&p->refcount) > 0);
 
        stats_data = dsa_get_address(pgStatLocal.dsa, p->body);
        Assert(stats_data);
 
        entry = pgstat_snapshot_insert(pgStatLocal.snapshot.stats, p->key, &found);
        Assert(!found);
 
        entry->data = MemoryContextAlloc(pgStatLocal.snapshot.context,
                                         kind_info->shared_size);
 
        /*
         * Acquire the LWLock directly instead of using
         * pg_stat_lock_entry_shared() which requires a reference.
         */
        LWLockAcquire(&stats_data->lock, LW_SHARED);
        memcpy(entry->data,
               pgstat_get_entry_data(kind, stats_data),
               kind_info->shared_size);
        LWLockRelease(&stats_data->lock);
    }
    dshash_seq_term(&hstat);
 
    /*
     * Build snapshot of all fixed-numbered stats.
     */
    for (int kind = PGSTAT_KIND_FIRST_VALID; kind <= PGSTAT_KIND_LAST; kind++)
    {
        const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
 
        if (!kind_info->fixed_amount)
        {
            Assert(kind_info->snapshot_cb == NULL);
            continue;
        }
 
        pgstat_build_snapshot_fixed(kind);
    }
 
    pgStatLocal.snapshot.mode = PGSTAT_FETCH_CONSISTENCY_SNAPSHOT;
}

References PgStat_KindInfo::accessed_across_databases, Assert(), PgStatShared_HashEntry::body, PgStat_Snapshot::context, PgStat_SnapshotEntry::data, PgStat_HashKey::dboid, PgStatShared_HashEntry::dropped, PgStat_LocalState::dsa, dsa_get_address(), dshash_seq_init(), dshash_seq_next(), dshash_seq_term(), PgStat_KindInfo::fixed_amount, GetCurrentTimestamp(), InvalidOid, PgStatShared_HashEntry::key, PgStat_HashKey::kind, PgStatShared_Common::lock, LW_SHARED, LWLockAcquire(), LWLockRelease(), MemoryContextAlloc(), PgStat_Snapshot::mode, MyDatabaseId, pg_atomic_read_u32(), pgstat_build_snapshot_fixed(), pgstat_fetch_consistency, PGSTAT_FETCH_CONSISTENCY_SNAPSHOT, pgstat_get_entry_data(), pgstat_get_kind_info(), PGSTAT_KIND_FIRST_VALID, PGSTAT_KIND_LAST, pgstat_prep_snapshot(), pgStatLocal, PgStatShared_HashEntry::refcount, PgStat_LocalState::shared_hash, PgStat_KindInfo::shared_size, PgStat_LocalState::snapshot, PgStat_KindInfo::snapshot_cb, PgStat_Snapshot::snapshot_timestamp, and PgStat_Snapshot::stats.

Referenced by pgstat_fetch_entry(), and pgstat_snapshot_fixed().

pgstat_build_snapshot_fixed()

static void pgstat_build_snapshot_fixed ( PgStat_Kind  kind )

static

Definition at line 1064 of file pgstat.c.

{
    const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
 
    Assert(kind_info->fixed_amount);
    Assert(kind_info->snapshot_cb != NULL);
 
    if (pgstat_fetch_consistency == PGSTAT_FETCH_CONSISTENCY_NONE)
    {
        /* rebuild every time */
        pgStatLocal.snapshot.fixed_valid[kind] = false;
    }
    else if (pgStatLocal.snapshot.fixed_valid[kind])
    {
        /* in snapshot mode we shouldn't get called again */
        Assert(pgstat_fetch_consistency == PGSTAT_FETCH_CONSISTENCY_CACHE);
        return;
    }
 
    Assert(!pgStatLocal.snapshot.fixed_valid[kind]);
 
    kind_info->snapshot_cb();
 
    Assert(!pgStatLocal.snapshot.fixed_valid[kind]);
    pgStatLocal.snapshot.fixed_valid[kind] = true;
}

References Assert(), PgStat_KindInfo::fixed_amount, PgStat_Snapshot::fixed_valid, pgstat_fetch_consistency, PGSTAT_FETCH_CONSISTENCY_CACHE, PGSTAT_FETCH_CONSISTENCY_NONE, pgstat_get_kind_info(), pgStatLocal, PgStat_LocalState::snapshot, and PgStat_KindInfo::snapshot_cb.

Referenced by pgstat_build_snapshot(), pgstat_snapshot_fixed(), and pgstat_write_statsfile().

pgstat_clear_snapshot()

void pgstat_clear_snapshot

(

void

)

Definition at line 785 of file pgstat.c.

{
    pgstat_assert_is_up();
 
    memset(&pgStatLocal.snapshot.fixed_valid, 0,
           sizeof(pgStatLocal.snapshot.fixed_valid));
    pgStatLocal.snapshot.stats = NULL;
    pgStatLocal.snapshot.mode = PGSTAT_FETCH_CONSISTENCY_NONE;
 
    /* Release memory, if any was allocated */
    if (pgStatLocal.snapshot.context)
    {
        MemoryContextDelete(pgStatLocal.snapshot.context);
 
        /* Reset variables */
        pgStatLocal.snapshot.context = NULL;
    }
 
    /*
     * Historically the backend_status.c facilities lived in this file, and
     * were reset with the same function. For now keep it that way, and
     * forward the reset request.
     */
    pgstat_clear_backend_activity_snapshot();
 
    /* Reset this flag, as it may be possible that a cleanup was forced. */
    force_stats_snapshot_clear = false;
}

References PgStat_Snapshot::context, PgStat_Snapshot::fixed_valid, force_stats_snapshot_clear, MemoryContextDelete(), PgStat_Snapshot::mode, pgstat_assert_is_up, pgstat_clear_backend_activity_snapshot(), PGSTAT_FETCH_CONSISTENCY_NONE, pgStatLocal, PgStat_LocalState::snapshot, and PgStat_Snapshot::stats.

Referenced by AtEOXact_PgStat(), pg_stat_clear_snapshot(), pgstat_get_stat_snapshot_timestamp(), pgstat_prep_snapshot(), and PostPrepare_PgStat().

pgstat_delete_pending_entry()

void pgstat_delete_pending_entry

(

PgStat_EntryRef *

entry_ref

)

Definition at line 1156 of file pgstat.c.

{
    PgStat_Kind kind = entry_ref->shared_entry->key.kind;
    const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
    void       *pending_data = entry_ref->pending;
 
    Assert(pending_data != NULL);
    /* !fixed_amount stats should be handled explicitly */
    Assert(!pgstat_get_kind_info(kind)->fixed_amount);
 
    if (kind_info->delete_pending_cb)
        kind_info->delete_pending_cb(entry_ref);
 
    pfree(pending_data);
    entry_ref->pending = NULL;
 
    dlist_delete(&entry_ref->pending_node);
}

References Assert(), PgStat_KindInfo::delete_pending_cb, dlist_delete(), PgStatShared_HashEntry::key, PgStat_HashKey::kind, PgStat_EntryRef::pending, PgStat_EntryRef::pending_node, pfree(), pgstat_get_kind_info(), and PgStat_EntryRef::shared_entry.

Referenced by pgstat_flush_pending_entries(), and pgstat_release_entry_ref().

pgstat_discard_stats()

void pgstat_discard_stats

(

void

)

Definition at line 422 of file pgstat.c.

{
    int         ret;
 
    /* NB: this needs to be done even in single user mode */
 
    ret = unlink(PGSTAT_STAT_PERMANENT_FILENAME);
    if (ret != 0)
    {
        if (errno == ENOENT)
            elog(DEBUG2,
                 "didn't need to unlink permanent stats file \"%s\" - didn't exist",
                 PGSTAT_STAT_PERMANENT_FILENAME);
        else
            ereport(LOG,
                    (errcode_for_file_access(),
                     errmsg("could not unlink permanent statistics file \"%s\": %m",
                            PGSTAT_STAT_PERMANENT_FILENAME)));
    }
    else
    {
        ereport(DEBUG2,
                (errcode_for_file_access(),
                 errmsg_internal("unlinked permanent statistics file \"%s\"",
                                 PGSTAT_STAT_PERMANENT_FILENAME)));
    }
 
    /*
     * Reset stats contents. This will set reset timestamps of fixed-numbered
     * stats to the current time (no variable stats exist).
     */
    pgstat_reset_after_failure();
}

References DEBUG2, elog(), ereport, errcode_for_file_access(), errmsg(), errmsg_internal(), LOG, pgstat_reset_after_failure(), and PGSTAT_STAT_PERMANENT_FILENAME.

Referenced by StartupXLOG().

pgstat_fetch_entry()

void* pgstat_fetch_entry	(	PgStat_Kind	kind,
		Oid	dboid,
		Oid	objoid
	)

Definition at line 815 of file pgstat.c.

{
    PgStat_HashKey key;
    PgStat_EntryRef *entry_ref;
    void       *stats_data;
    const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
 
    /* should be called from backends */
    Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
    Assert(!kind_info->fixed_amount);
 
    pgstat_prep_snapshot();
 
    key.kind = kind;
    key.dboid = dboid;
    key.objoid = objoid;
 
    /* if we need to build a full snapshot, do so */
    if (pgstat_fetch_consistency == PGSTAT_FETCH_CONSISTENCY_SNAPSHOT)
        pgstat_build_snapshot();
 
    /* if caching is desired, look up in cache */
    if (pgstat_fetch_consistency > PGSTAT_FETCH_CONSISTENCY_NONE)
    {
        PgStat_SnapshotEntry *entry = NULL;
 
        entry = pgstat_snapshot_lookup(pgStatLocal.snapshot.stats, key);
 
        if (entry)
            return entry->data;
 
        /*
         * If we built a full snapshot and the key is not in
         * pgStatLocal.snapshot.stats, there are no matching stats.
         */
        if (pgstat_fetch_consistency == PGSTAT_FETCH_CONSISTENCY_SNAPSHOT)
            return NULL;
    }
 
    pgStatLocal.snapshot.mode = pgstat_fetch_consistency;
 
    entry_ref = pgstat_get_entry_ref(kind, dboid, objoid, false, NULL);
 
    if (entry_ref == NULL || entry_ref->shared_entry->dropped)
    {
        /* create empty entry when using PGSTAT_FETCH_CONSISTENCY_CACHE */
        if (pgstat_fetch_consistency == PGSTAT_FETCH_CONSISTENCY_CACHE)
        {
            PgStat_SnapshotEntry *entry = NULL;
            bool        found;
 
            entry = pgstat_snapshot_insert(pgStatLocal.snapshot.stats, key, &found);
            Assert(!found);
            entry->data = NULL;
        }
        return NULL;
    }
 
    /*
     * Allocate in caller's context for PGSTAT_FETCH_CONSISTENCY_NONE,
     * otherwise we could quickly end up with a fair bit of memory used due to
     * repeated accesses.
     */
    if (pgstat_fetch_consistency == PGSTAT_FETCH_CONSISTENCY_NONE)
        stats_data = palloc(kind_info->shared_data_len);
    else
        stats_data = MemoryContextAlloc(pgStatLocal.snapshot.context,
                                        kind_info->shared_data_len);
 
    pgstat_lock_entry_shared(entry_ref, false);
    memcpy(stats_data,
           pgstat_get_entry_data(kind, entry_ref->shared_stats),
           kind_info->shared_data_len);
    pgstat_unlock_entry(entry_ref);
 
    if (pgstat_fetch_consistency > PGSTAT_FETCH_CONSISTENCY_NONE)
    {
        PgStat_SnapshotEntry *entry = NULL;
        bool        found;
 
        entry = pgstat_snapshot_insert(pgStatLocal.snapshot.stats, key, &found);
        entry->data = stats_data;
    }
 
    return stats_data;
}

References Assert(), PgStat_Snapshot::context, PgStat_SnapshotEntry::data, PgStatShared_HashEntry::dropped, PgStat_KindInfo::fixed_amount, IsPostmasterEnvironment, IsUnderPostmaster, sort-test::key, MemoryContextAlloc(), PgStat_Snapshot::mode, palloc(), pgstat_build_snapshot(), pgstat_fetch_consistency, PGSTAT_FETCH_CONSISTENCY_CACHE, PGSTAT_FETCH_CONSISTENCY_NONE, PGSTAT_FETCH_CONSISTENCY_SNAPSHOT, pgstat_get_entry_data(), pgstat_get_entry_ref(), pgstat_get_kind_info(), pgstat_lock_entry_shared(), pgstat_prep_snapshot(), pgstat_unlock_entry(), pgStatLocal, PgStat_KindInfo::shared_data_len, PgStat_EntryRef::shared_entry, PgStat_EntryRef::shared_stats, PgStat_LocalState::snapshot, and PgStat_Snapshot::stats.

Referenced by pgstat_fetch_replslot(), pgstat_fetch_stat_dbentry(), pgstat_fetch_stat_funcentry(), pgstat_fetch_stat_subscription(), and pgstat_fetch_stat_tabentry_ext().

pgstat_fetch_pending_entry()

PgStat_EntryRef* pgstat_fetch_pending_entry	(	PgStat_Kind	kind,
		Oid	dboid,
		Oid	objoid
	)

Definition at line 1143 of file pgstat.c.

{
    PgStat_EntryRef *entry_ref;
 
    entry_ref = pgstat_get_entry_ref(kind, dboid, objoid, false, NULL);
 
    if (entry_ref == NULL || entry_ref->pending == NULL)
        return NULL;
 
    return entry_ref;
}

References PgStat_EntryRef::pending, and pgstat_get_entry_ref().

Referenced by find_funcstat_entry(), and find_tabstat_entry().

pgstat_flush_pending_entries()

static bool pgstat_flush_pending_entries ( bool  nowait )

static

Definition at line 1180 of file pgstat.c.

{
    bool        have_pending = false;
    dlist_node *cur = NULL;
 
    /*
     * Need to be a bit careful iterating over the list of pending entries.
     * Processing a pending entry may queue further pending entries to the end
     * of the list that we want to process, so a simple iteration won't do.
     * Further complicating matters is that we want to delete the current
     * entry in each iteration from the list if we flushed successfully.
     *
     * So we just keep track of the next pointer in each loop iteration.
     */
    if (!dlist_is_empty(&pgStatPending))
        cur = dlist_head_node(&pgStatPending);
 
    while (cur)
    {
        PgStat_EntryRef *entry_ref =
            dlist_container(PgStat_EntryRef, pending_node, cur);
        PgStat_HashKey key = entry_ref->shared_entry->key;
        PgStat_Kind kind = key.kind;
        const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
        bool        did_flush;
        dlist_node *next;
 
        Assert(!kind_info->fixed_amount);
        Assert(kind_info->flush_pending_cb != NULL);
 
        /* flush the stats, if possible */
        did_flush = kind_info->flush_pending_cb(entry_ref, nowait);
 
        Assert(did_flush || nowait);
 
        /* determine next entry, before deleting the pending entry */
        if (dlist_has_next(&pgStatPending, cur))
            next = dlist_next_node(&pgStatPending, cur);
        else
            next = NULL;
 
        /* if successfully flushed, remove entry */
        if (did_flush)
            pgstat_delete_pending_entry(entry_ref);
        else
            have_pending = true;
 
        cur = next;
    }
 
    Assert(dlist_is_empty(&pgStatPending) == !have_pending);
 
    return have_pending;
}

References Assert(), cur, dlist_container, dlist_has_next(), dlist_head_node(), dlist_is_empty(), dlist_next_node(), PgStat_KindInfo::fixed_amount, PgStat_KindInfo::flush_pending_cb, PgStatShared_HashEntry::key, sort-test::key, next, pgstat_delete_pending_entry(), pgstat_get_kind_info(), pgStatPending, and PgStat_EntryRef::shared_entry.

Referenced by pgstat_report_stat().

pgstat_force_next_flush()

void pgstat_force_next_flush

(

void

)

Definition at line 697 of file pgstat.c.

{
    pgStatForceNextFlush = true;
}

References pgStatForceNextFlush.

Referenced by pg_stat_force_next_flush().

pgstat_get_kind_from_str()

PgStat_Kind pgstat_get_kind_from_str

(

char *

kind_str

)

Definition at line 1242 of file pgstat.c.

{
    for (int kind = PGSTAT_KIND_FIRST_VALID; kind <= PGSTAT_KIND_LAST; kind++)
    {
        if (pg_strcasecmp(kind_str, pgstat_kind_infos[kind].name) == 0)
            return kind;
    }
 
    ereport(ERROR,
            (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
             errmsg("invalid statistics kind: \"%s\"", kind_str)));
    return PGSTAT_KIND_DATABASE;    /* avoid compiler warnings */
}

References ereport, errcode(), errmsg(), ERROR, name, pg_strcasecmp(), PGSTAT_KIND_DATABASE, PGSTAT_KIND_FIRST_VALID, pgstat_kind_infos, and PGSTAT_KIND_LAST.

Referenced by pg_stat_have_stats().

pgstat_get_kind_info()

const PgStat_KindInfo* pgstat_get_kind_info

(

PgStat_Kind

kind

)

Definition at line 1263 of file pgstat.c.

{
    Assert(pgstat_is_kind_valid(kind));
 
    return &pgstat_kind_infos[kind];
}

References Assert(), pgstat_is_kind_valid(), and pgstat_kind_infos.

Referenced by pgstat_build_snapshot(), pgstat_build_snapshot_fixed(), pgstat_create_transactional(), pgstat_delete_pending_entry(), pgstat_fetch_entry(), pgstat_flush_pending_entries(), pgstat_get_entry_data(), pgstat_get_entry_len(), pgstat_have_entry(), pgstat_init_entry(), pgstat_prep_pending_entry(), pgstat_read_statsfile(), pgstat_reset(), pgstat_reset_after_failure(), pgstat_reset_entry(), pgstat_reset_of_kind(), pgstat_snapshot_fixed(), pgstat_write_statsfile(), and shared_stat_reset_contents().

pgstat_get_stat_snapshot_timestamp()

TimestampTz pgstat_get_stat_snapshot_timestamp

(

bool *

have_snapshot

)

Definition at line 908 of file pgstat.c.

{
    if (force_stats_snapshot_clear)
        pgstat_clear_snapshot();
 
    if (pgStatLocal.snapshot.mode == PGSTAT_FETCH_CONSISTENCY_SNAPSHOT)
    {
        *have_snapshot = true;
        return pgStatLocal.snapshot.snapshot_timestamp;
    }
 
    *have_snapshot = false;
 
    return 0;
}

References force_stats_snapshot_clear, PgStat_Snapshot::mode, pgstat_clear_snapshot(), PGSTAT_FETCH_CONSISTENCY_SNAPSHOT, pgStatLocal, PgStat_LocalState::snapshot, and PgStat_Snapshot::snapshot_timestamp.

Referenced by pg_stat_get_snapshot_timestamp().

pgstat_have_entry()

bool pgstat_have_entry	(	PgStat_Kind	kind,
		Oid	dboid,
		Oid	objoid
	)

Definition at line 925 of file pgstat.c.

{
    /* fixed-numbered stats always exist */
    if (pgstat_get_kind_info(kind)->fixed_amount)
        return true;
 
    return pgstat_get_entry_ref(kind, dboid, objoid, false, NULL) != NULL;
}

References pgstat_get_entry_ref(), and pgstat_get_kind_info().

Referenced by pg_stat_have_stats().

pgstat_initialize()

void pgstat_initialize

(

void

)

Definition at line 540 of file pgstat.c.

{
    Assert(!pgstat_is_initialized);
 
    pgstat_attach_shmem();
 
    pgstat_init_wal();
 
    /* Set up a process-exit hook to clean up */
    before_shmem_exit(pgstat_shutdown_hook, 0);
 
#ifdef USE_ASSERT_CHECKING
    pgstat_is_initialized = true;
#endif
}

References Assert(), before_shmem_exit(), pgstat_attach_shmem(), pgstat_init_wal(), and pgstat_shutdown_hook().

Referenced by BaseInit().

pgstat_is_kind_valid()

static bool pgstat_is_kind_valid ( int  ikind )

inlinestatic

Definition at line 1257 of file pgstat.c.

{
    return ikind >= PGSTAT_KIND_FIRST_VALID && ikind <= PGSTAT_KIND_LAST;
}

References PGSTAT_KIND_FIRST_VALID, and PGSTAT_KIND_LAST.

Referenced by pgstat_get_kind_info(), pgstat_read_statsfile(), and pgstat_snapshot_fixed().

pgstat_prep_pending_entry()

PgStat_EntryRef* pgstat_prep_pending_entry	(	PgStat_Kind	kind,
		Oid	dboid,
		Oid	objoid,
		bool *	created_entry
	)

Definition at line 1105 of file pgstat.c.

{
    PgStat_EntryRef *entry_ref;
 
    /* need to be able to flush out */
    Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
 
    if (unlikely(!pgStatPendingContext))
    {
        pgStatPendingContext =
            AllocSetContextCreate(TopMemoryContext,
                                  "PgStat Pending",
                                  ALLOCSET_SMALL_SIZES);
    }
 
    entry_ref = pgstat_get_entry_ref(kind, dboid, objoid,
                                     true, created_entry);
 
    if (entry_ref->pending == NULL)
    {
        size_t      entrysize = pgstat_get_kind_info(kind)->pending_size;
 
        Assert(entrysize != (size_t) -1);
 
        entry_ref->pending = MemoryContextAllocZero(pgStatPendingContext, entrysize);
        dlist_push_tail(&pgStatPending, &entry_ref->pending_node);
    }
 
    return entry_ref;
}

References ALLOCSET_SMALL_SIZES, AllocSetContextCreate, Assert(), dlist_push_tail(), MemoryContextAllocZero(), PgStat_EntryRef::pending, PgStat_EntryRef::pending_node, PgStat_KindInfo::pending_size, pgstat_get_entry_ref(), pgstat_get_kind_info(), pgStatPending, pgStatPendingContext, TopMemoryContext, and unlikely.

Referenced by pgstat_init_function_usage(), pgstat_prep_database_pending(), pgstat_prep_relation_pending(), and pgstat_report_subscription_error().

pgstat_prep_snapshot()

static void pgstat_prep_snapshot ( void  )

static

Definition at line 955 of file pgstat.c.

{
    if (force_stats_snapshot_clear)
        pgstat_clear_snapshot();
 
    if (pgstat_fetch_consistency == PGSTAT_FETCH_CONSISTENCY_NONE ||
        pgStatLocal.snapshot.stats != NULL)
        return;
 
    if (!pgStatLocal.snapshot.context)
        pgStatLocal.snapshot.context = AllocSetContextCreate(TopMemoryContext,
                                                             "PgStat Snapshot",
                                                             ALLOCSET_SMALL_SIZES);
 
    pgStatLocal.snapshot.stats =
        pgstat_snapshot_create(pgStatLocal.snapshot.context,
                               PGSTAT_SNAPSHOT_HASH_SIZE,
                               NULL);
}

References ALLOCSET_SMALL_SIZES, AllocSetContextCreate, PgStat_Snapshot::context, force_stats_snapshot_clear, pgstat_clear_snapshot(), pgstat_fetch_consistency, PGSTAT_FETCH_CONSISTENCY_NONE, PGSTAT_SNAPSHOT_HASH_SIZE, pgStatLocal, PgStat_LocalState::snapshot, PgStat_Snapshot::stats, and TopMemoryContext.

Referenced by pgstat_build_snapshot(), and pgstat_fetch_entry().

pgstat_read_statsfile()

static void pgstat_read_statsfile ( void  )

static

Definition at line 1483 of file pgstat.c.

{
    FILE       *fpin;
    int32       format_id;
    bool        found;
    const char *statfile = PGSTAT_STAT_PERMANENT_FILENAME;
    PgStat_ShmemControl *shmem = pgStatLocal.shmem;
 
    /* shouldn't be called from postmaster */
    Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
 
    elog(DEBUG2, "reading stats file \"%s\"", statfile);
 
    /*
     * Try to open the stats file. If it doesn't exist, the backends simply
     * returns zero for anything and statistics simply starts from scratch
     * with empty counters.
     *
     * ENOENT is a possibility if stats collection was previously disabled or
     * has not yet written the stats file for the first time.  Any other
     * failure condition is suspicious.
     */
    if ((fpin = AllocateFile(statfile, PG_BINARY_R)) == NULL)
    {
        if (errno != ENOENT)
            ereport(LOG,
                    (errcode_for_file_access(),
                     errmsg("could not open statistics file \"%s\": %m",
                            statfile)));
        pgstat_reset_after_failure();
        return;
    }
 
    /*
     * Verify it's of the expected format.
     */
    if (!read_chunk_s(fpin, &format_id) ||
        format_id != PGSTAT_FILE_FORMAT_ID)
        goto error;
 
    /*
     * XXX: The following could now be generalized to just iterate over
     * pgstat_kind_infos instead of knowing about the different kinds of
     * stats.
     */
 
    /*
     * Read archiver stats struct
     */
    if (!read_chunk_s(fpin, &shmem->archiver.stats))
        goto error;
 
    /*
     * Read bgwriter stats struct
     */
    if (!read_chunk_s(fpin, &shmem->bgwriter.stats))
        goto error;
 
    /*
     * Read checkpointer stats struct
     */
    if (!read_chunk_s(fpin, &shmem->checkpointer.stats))
        goto error;
 
    /*
     * Read IO stats struct
     */
    if (!read_chunk_s(fpin, &shmem->io.stats))
        goto error;
 
    /*
     * Read SLRU stats struct
     */
    if (!read_chunk_s(fpin, &shmem->slru.stats))
        goto error;
 
    /*
     * Read WAL stats struct
     */
    if (!read_chunk_s(fpin, &shmem->wal.stats))
        goto error;
 
    /*
     * We found an existing statistics file. Read it and put all the hash
     * table entries into place.
     */
    for (;;)
    {
        int         t = fgetc(fpin);
 
        switch (t)
        {
            case 'S':
            case 'N':
                {
                    PgStat_HashKey key;
                    PgStatShared_HashEntry *p;
                    PgStatShared_Common *header;
 
                    CHECK_FOR_INTERRUPTS();
 
                    if (t == 'S')
                    {
                        /* normal stats entry, identified by PgStat_HashKey */
                        if (!read_chunk_s(fpin, &key))
                            goto error;
 
                        if (!pgstat_is_kind_valid(key.kind))
                            goto error;
                    }
                    else
                    {
                        /* stats entry identified by name on disk (e.g. slots) */
                        const PgStat_KindInfo *kind_info = NULL;
                        PgStat_Kind kind;
                        NameData    name;
 
                        if (!read_chunk_s(fpin, &kind))
                            goto error;
                        if (!read_chunk_s(fpin, &name))
                            goto error;
                        if (!pgstat_is_kind_valid(kind))
                            goto error;
 
                        kind_info = pgstat_get_kind_info(kind);
 
                        if (!kind_info->from_serialized_name)
                            goto error;
 
                        if (!kind_info->from_serialized_name(&name, &key))
                        {
                            /* skip over data for entry we don't care about */
                            if (fseek(fpin, pgstat_get_entry_len(kind), SEEK_CUR) != 0)
                                goto error;
 
                            continue;
                        }
 
                        Assert(key.kind == kind);
                    }
 
                    /*
                     * This intentionally doesn't use pgstat_get_entry_ref() -
                     * putting all stats into checkpointer's
                     * pgStatEntryRefHash would be wasted effort and memory.
                     */
                    p = dshash_find_or_insert(pgStatLocal.shared_hash, &key, &found);
 
                    /* don't allow duplicate entries */
                    if (found)
                    {
                        dshash_release_lock(pgStatLocal.shared_hash, p);
                        elog(WARNING, "found duplicate stats entry %d/%u/%u",
                             key.kind, key.dboid, key.objoid);
                        goto error;
                    }
 
                    header = pgstat_init_entry(key.kind, p);
                    dshash_release_lock(pgStatLocal.shared_hash, p);
 
                    if (!read_chunk(fpin,
                                    pgstat_get_entry_data(key.kind, header),
                                    pgstat_get_entry_len(key.kind)))
                        goto error;
 
                    break;
                }
            case 'E':
                /* check that 'E' actually signals end of file */
                if (fgetc(fpin) != EOF)
                    goto error;
 
                goto done;
 
            default:
                goto error;
        }
    }
 
done:
    FreeFile(fpin);
 
    elog(DEBUG2, "removing permanent stats file \"%s\"", statfile);
    unlink(statfile);
 
    return;
 
error:
    ereport(LOG,
            (errmsg("corrupted statistics file \"%s\"", statfile)));
 
    pgstat_reset_after_failure();
 
    goto done;
}

References AllocateFile(), PgStat_ShmemControl::archiver, Assert(), PgStat_ShmemControl::bgwriter, CHECK_FOR_INTERRUPTS, PgStat_ShmemControl::checkpointer, DEBUG2, dshash_find_or_insert(), dshash_release_lock(), elog(), ereport, errcode_for_file_access(), errmsg(), error(), FreeFile(), PgStat_KindInfo::from_serialized_name, PgStat_ShmemControl::io, IsPostmasterEnvironment, IsUnderPostmaster, sort-test::key, LOG, name, PG_BINARY_R, PGSTAT_FILE_FORMAT_ID, pgstat_get_entry_data(), pgstat_get_entry_len(), pgstat_get_kind_info(), pgstat_init_entry(), pgstat_is_kind_valid(), pgstat_reset_after_failure(), PGSTAT_STAT_PERMANENT_FILENAME, pgStatLocal, read_chunk(), read_chunk_s, PgStat_LocalState::shared_hash, PgStat_LocalState::shmem, PgStat_ShmemControl::slru, PgStatShared_Archiver::stats, PgStatShared_BgWriter::stats, PgStatShared_Checkpointer::stats, PgStatShared_IO::stats, PgStatShared_SLRU::stats, PgStatShared_Wal::stats, PgStat_ShmemControl::wal, and WARNING.

Referenced by pgstat_restore_stats().

pgstat_report_stat()

long pgstat_report_stat

(

bool

force

)

Definition at line 582 of file pgstat.c.

{
    static TimestampTz pending_since = 0;
    static TimestampTz last_flush = 0;
    bool        partial_flush;
    TimestampTz now;
    bool        nowait;
 
    pgstat_assert_is_up();
    Assert(!IsTransactionOrTransactionBlock());
 
    /* "absorb" the forced flush even if there's nothing to flush */
    if (pgStatForceNextFlush)
    {
        force = true;
        pgStatForceNextFlush = false;
    }
 
    /* Don't expend a clock check if nothing to do */
    if (dlist_is_empty(&pgStatPending) &&
        !have_iostats &&
        !have_slrustats &&
        !pgstat_have_pending_wal())
    {
        Assert(pending_since == 0);
        return 0;
    }
 
    /*
     * There should never be stats to report once stats are shut down. Can't
     * assert that before the checks above, as there is an unconditional
     * pgstat_report_stat() call in pgstat_shutdown_hook() - which at least
     * the process that ran pgstat_before_server_shutdown() will still call.
     */
    Assert(!pgStatLocal.shmem->is_shutdown);
 
    if (force)
    {
        /*
         * Stats reports are forced either when it's been too long since stats
         * have been reported or in processes that force stats reporting to
         * happen at specific points (including shutdown). In the former case
         * the transaction stop time might be quite old, in the latter it
         * would never get cleared.
         */
        now = GetCurrentTimestamp();
    }
    else
    {
        now = GetCurrentTransactionStopTimestamp();
 
        if (pending_since > 0 &&
            TimestampDifferenceExceeds(pending_since, now, PGSTAT_MAX_INTERVAL))
        {
            /* don't keep pending updates longer than PGSTAT_MAX_INTERVAL */
            force = true;
        }
        else if (last_flush > 0 &&
                 !TimestampDifferenceExceeds(last_flush, now, PGSTAT_MIN_INTERVAL))
        {
            /* don't flush too frequently */
            if (pending_since == 0)
                pending_since = now;
 
            return PGSTAT_IDLE_INTERVAL;
        }
    }
 
    pgstat_update_dbstats(now);
 
    /* don't wait for lock acquisition when !force */
    nowait = !force;
 
    partial_flush = false;
 
    /* flush database / relation / function / ... stats */
    partial_flush |= pgstat_flush_pending_entries(nowait);
 
    /* flush IO stats */
    partial_flush |= pgstat_flush_io(nowait);
 
    /* flush wal stats */
    partial_flush |= pgstat_flush_wal(nowait);
 
    /* flush SLRU stats */
    partial_flush |= pgstat_slru_flush(nowait);
 
    last_flush = now;
 
    /*
     * If some of the pending stats could not be flushed due to lock
     * contention, let the caller know when to retry.
     */
    if (partial_flush)
    {
        /* force should have prevented us from getting here */
        Assert(!force);
 
        /* remember since when stats have been pending */
        if (pending_since == 0)
            pending_since = now;
 
        return PGSTAT_IDLE_INTERVAL;
    }
 
    pending_since = 0;
 
    return 0;
}

References Assert(), dlist_is_empty(), GetCurrentTimestamp(), GetCurrentTransactionStopTimestamp(), have_iostats, have_slrustats, PgStat_ShmemControl::is_shutdown, IsTransactionOrTransactionBlock(), now(), pgstat_assert_is_up, pgstat_flush_io(), pgstat_flush_pending_entries(), pgstat_flush_wal(), pgstat_have_pending_wal(), PGSTAT_IDLE_INTERVAL, PGSTAT_MAX_INTERVAL, PGSTAT_MIN_INTERVAL, pgstat_slru_flush(), pgstat_update_dbstats(), pgStatForceNextFlush, pgStatLocal, pgStatPending, PgStat_LocalState::shmem, and TimestampDifferenceExceeds().

Referenced by AllTablesyncsReady(), apply_handle_commit_internal(), apply_handle_commit_prepared(), apply_handle_prepare(), apply_handle_rollback_prepared(), apply_handle_stream_prepare(), LogicalRepApplyLoop(), LogicalRepSyncTableStart(), pg_attribute_noreturn(), pgstat_before_server_shutdown(), pgstat_shutdown_hook(), PostgresMain(), process_syncing_tables_for_apply(), process_syncing_tables_for_sync(), ProcessInterrupts(), standby_redo(), and worker_spi_main().

pgstat_reset()

void pgstat_reset	(	PgStat_Kind	kind,
		Oid	dboid,
		Oid	objoid
	)

Definition at line 737 of file pgstat.c.

{
    const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
    TimestampTz ts = GetCurrentTimestamp();
 
    /* not needed atm, and doesn't make sense with the current signature */
    Assert(!pgstat_get_kind_info(kind)->fixed_amount);
 
    /* reset the "single counter" */
    pgstat_reset_entry(kind, dboid, objoid, ts);
 
    if (!kind_info->accessed_across_databases)
        pgstat_reset_database_timestamp(dboid, ts);
}

References PgStat_KindInfo::accessed_across_databases, Assert(), GetCurrentTimestamp(), pgstat_get_kind_info(), pgstat_reset_database_timestamp(), and pgstat_reset_entry().

Referenced by pg_stat_reset_single_function_counters(), pg_stat_reset_single_table_counters(), pg_stat_reset_subscription_stats(), pgstat_create_transactional(), and pgstat_reset_replslot().

pgstat_reset_after_failure()

static void pgstat_reset_after_failure ( void  )

static

Definition at line 1684 of file pgstat.c.

{
    TimestampTz ts = GetCurrentTimestamp();
 
    /* reset fixed-numbered stats */
    for (int kind = PGSTAT_KIND_FIRST_VALID; kind <= PGSTAT_KIND_LAST; kind++)
    {
        const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
 
        if (!kind_info->fixed_amount)
            continue;
 
        kind_info->reset_all_cb(ts);
    }
 
    /* and drop variable-numbered ones */
    pgstat_drop_all_entries();
}

References PgStat_KindInfo::fixed_amount, GetCurrentTimestamp(), pgstat_drop_all_entries(), pgstat_get_kind_info(), PGSTAT_KIND_FIRST_VALID, PGSTAT_KIND_LAST, and PgStat_KindInfo::reset_all_cb.

Referenced by pgstat_discard_stats(), and pgstat_read_statsfile().

pgstat_reset_counters()

void pgstat_reset_counters

(

void

)

Definition at line 718 of file pgstat.c.

{
    TimestampTz ts = GetCurrentTimestamp();
 
    pgstat_reset_matching_entries(match_db_entries,
                                  ObjectIdGetDatum(MyDatabaseId),
                                  ts);
}

References GetCurrentTimestamp(), match_db_entries(), MyDatabaseId, ObjectIdGetDatum(), and pgstat_reset_matching_entries().

Referenced by pg_stat_reset().

pgstat_reset_of_kind()

void pgstat_reset_of_kind

(

PgStat_Kind

kind

)

Definition at line 759 of file pgstat.c.

{
    const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
    TimestampTz ts = GetCurrentTimestamp();
 
    if (kind_info->fixed_amount)
        kind_info->reset_all_cb(ts);
    else
        pgstat_reset_entries_of_kind(kind, ts);
}

References PgStat_KindInfo::fixed_amount, GetCurrentTimestamp(), pgstat_get_kind_info(), pgstat_reset_entries_of_kind(), and PgStat_KindInfo::reset_all_cb.

Referenced by pg_stat_reset_replication_slot(), pg_stat_reset_shared(), pg_stat_reset_slru(), and pg_stat_reset_subscription_stats().

pgstat_restore_stats()

void pgstat_restore_stats

(

void

)

Definition at line 410 of file pgstat.c.

{
    pgstat_read_statsfile();
}

References pgstat_read_statsfile().

Referenced by StartupXLOG().

pgstat_shutdown_hook()

static void pgstat_shutdown_hook ( int  code, Datum  arg  )

static

Definition at line 506 of file pgstat.c.

{
    Assert(!pgstat_is_shutdown);
    Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
 
    /*
     * If we got as far as discovering our own database ID, we can flush out
     * what we did so far.  Otherwise, we'd be reporting an invalid database
     * ID, so forget it.  (This means that accesses to pg_database during
     * failed backend starts might never get counted.)
     */
    if (OidIsValid(MyDatabaseId))
        pgstat_report_disconnect(MyDatabaseId);
 
    pgstat_report_stat(true);
 
    /* there shouldn't be any pending changes left */
    Assert(dlist_is_empty(&pgStatPending));
    dlist_init(&pgStatPending);
 
    pgstat_detach_shmem();
 
#ifdef USE_ASSERT_CHECKING
    pgstat_is_shutdown = true;
#endif
}

References Assert(), dlist_init(), dlist_is_empty(), IsPostmasterEnvironment, IsUnderPostmaster, MyDatabaseId, OidIsValid, pgstat_detach_shmem(), pgstat_report_disconnect(), pgstat_report_stat(), and pgStatPending.

Referenced by pgstat_initialize().

pgstat_snapshot_fixed()

void pgstat_snapshot_fixed

(

PgStat_Kind

kind

)

Definition at line 941 of file pgstat.c.

{
    Assert(pgstat_is_kind_valid(kind));
    Assert(pgstat_get_kind_info(kind)->fixed_amount);
 
    if (pgstat_fetch_consistency == PGSTAT_FETCH_CONSISTENCY_SNAPSHOT)
        pgstat_build_snapshot();
    else
        pgstat_build_snapshot_fixed(kind);
 
    Assert(pgStatLocal.snapshot.fixed_valid[kind]);
}

References Assert(), PgStat_Snapshot::fixed_valid, pgstat_build_snapshot(), pgstat_build_snapshot_fixed(), pgstat_fetch_consistency, PGSTAT_FETCH_CONSISTENCY_SNAPSHOT, pgstat_get_kind_info(), pgstat_is_kind_valid(), pgStatLocal, and PgStat_LocalState::snapshot.

Referenced by pgstat_fetch_slru(), pgstat_fetch_stat_archiver(), pgstat_fetch_stat_bgwriter(), pgstat_fetch_stat_checkpointer(), pgstat_fetch_stat_io(), and pgstat_fetch_stat_wal().

pgstat_write_statsfile()

static void pgstat_write_statsfile ( void  )

static

Definition at line 1308 of file pgstat.c.

{
    FILE       *fpout;
    int32       format_id;
    const char *tmpfile = PGSTAT_STAT_PERMANENT_TMPFILE;
    const char *statfile = PGSTAT_STAT_PERMANENT_FILENAME;
    dshash_seq_status hstat;
    PgStatShared_HashEntry *ps;
 
    pgstat_assert_is_up();
 
    /* we're shutting down, so it's ok to just override this */
    pgstat_fetch_consistency = PGSTAT_FETCH_CONSISTENCY_NONE;
 
    elog(DEBUG2, "writing stats file \"%s\"", statfile);
 
    /*
     * Open the statistics temp file to write out the current values.
     */
    fpout = AllocateFile(tmpfile, PG_BINARY_W);
    if (fpout == NULL)
    {
        ereport(LOG,
                (errcode_for_file_access(),
                 errmsg("could not open temporary statistics file \"%s\": %m",
                        tmpfile)));
        return;
    }
 
    /*
     * Write the file header --- currently just a format ID.
     */
    format_id = PGSTAT_FILE_FORMAT_ID;
    write_chunk_s(fpout, &format_id);
 
    /*
     * XXX: The following could now be generalized to just iterate over
     * pgstat_kind_infos instead of knowing about the different kinds of
     * stats.
     */
 
    /*
     * Write archiver stats struct
     */
    pgstat_build_snapshot_fixed(PGSTAT_KIND_ARCHIVER);
    write_chunk_s(fpout, &pgStatLocal.snapshot.archiver);
 
    /*
     * Write bgwriter stats struct
     */
    pgstat_build_snapshot_fixed(PGSTAT_KIND_BGWRITER);
    write_chunk_s(fpout, &pgStatLocal.snapshot.bgwriter);
 
    /*
     * Write checkpointer stats struct
     */
    pgstat_build_snapshot_fixed(PGSTAT_KIND_CHECKPOINTER);
    write_chunk_s(fpout, &pgStatLocal.snapshot.checkpointer);
 
    /*
     * Write IO stats struct
     */
    pgstat_build_snapshot_fixed(PGSTAT_KIND_IO);
    write_chunk_s(fpout, &pgStatLocal.snapshot.io);
 
    /*
     * Write SLRU stats struct
     */
    pgstat_build_snapshot_fixed(PGSTAT_KIND_SLRU);
    write_chunk_s(fpout, &pgStatLocal.snapshot.slru);
 
    /*
     * Write WAL stats struct
     */
    pgstat_build_snapshot_fixed(PGSTAT_KIND_WAL);
    write_chunk_s(fpout, &pgStatLocal.snapshot.wal);
 
    /*
     * Walk through the stats entries
     */
    dshash_seq_init(&hstat, pgStatLocal.shared_hash, false);
    while ((ps = dshash_seq_next(&hstat)) != NULL)
    {
        PgStatShared_Common *shstats;
        const PgStat_KindInfo *kind_info = NULL;
 
        CHECK_FOR_INTERRUPTS();
 
        /* we may have some "dropped" entries not yet removed, skip them */
        Assert(!ps->dropped);
        if (ps->dropped)
            continue;
 
        shstats = (PgStatShared_Common *) dsa_get_address(pgStatLocal.dsa, ps->body);
 
        kind_info = pgstat_get_kind_info(ps->key.kind);
 
        /* if not dropped the valid-entry refcount should exist */
        Assert(pg_atomic_read_u32(&ps->refcount) > 0);
 
        if (!kind_info->to_serialized_name)
        {
            /* normal stats entry, identified by PgStat_HashKey */
            fputc('S', fpout);
            write_chunk_s(fpout, &ps->key);
        }
        else
        {
            /* stats entry identified by name on disk (e.g. slots) */
            NameData    name;
 
            kind_info->to_serialized_name(&ps->key, shstats, &name);
 
            fputc('N', fpout);
            write_chunk_s(fpout, &ps->key.kind);
            write_chunk_s(fpout, &name);
        }
 
        /* Write except the header part of the entry */
        write_chunk(fpout,
                    pgstat_get_entry_data(ps->key.kind, shstats),
                    pgstat_get_entry_len(ps->key.kind));
    }
    dshash_seq_term(&hstat);
 
    /*
     * No more output to be done. Close the temp file and replace the old
     * pgstat.stat with it.  The ferror() check replaces testing for error
     * after each individual fputc or fwrite (in write_chunk()) above.
     */
    fputc('E', fpout);
 
    if (ferror(fpout))
    {
        ereport(LOG,
                (errcode_for_file_access(),
                 errmsg("could not write temporary statistics file \"%s\": %m",
                        tmpfile)));
        FreeFile(fpout);
        unlink(tmpfile);
    }
    else if (FreeFile(fpout) < 0)
    {
        ereport(LOG,
                (errcode_for_file_access(),
                 errmsg("could not close temporary statistics file \"%s\": %m",
                        tmpfile)));
        unlink(tmpfile);
    }
    else if (rename(tmpfile, statfile) < 0)
    {
        ereport(LOG,
                (errcode_for_file_access(),
                 errmsg("could not rename temporary statistics file \"%s\" to \"%s\": %m",
                        tmpfile, statfile)));
        unlink(tmpfile);
    }
}

References AllocateFile(), PgStat_Snapshot::archiver, Assert(), PgStat_Snapshot::bgwriter, CHECK_FOR_INTERRUPTS, PgStat_Snapshot::checkpointer, DEBUG2, PgStat_LocalState::dsa, dsa_get_address(), dshash_seq_init(), dshash_seq_next(), dshash_seq_term(), elog(), ereport, errcode_for_file_access(), errmsg(), FreeFile(), PgStat_Snapshot::io, LOG, name, pg_atomic_read_u32(), PG_BINARY_W, pgstat_assert_is_up, pgstat_build_snapshot_fixed(), pgstat_fetch_consistency, PGSTAT_FETCH_CONSISTENCY_NONE, PGSTAT_FILE_FORMAT_ID, pgstat_get_entry_data(), pgstat_get_entry_len(), pgstat_get_kind_info(), PGSTAT_KIND_ARCHIVER, PGSTAT_KIND_BGWRITER, PGSTAT_KIND_CHECKPOINTER, PGSTAT_KIND_IO, PGSTAT_KIND_SLRU, PGSTAT_KIND_WAL, PGSTAT_STAT_PERMANENT_FILENAME, PGSTAT_STAT_PERMANENT_TMPFILE, pgStatLocal, ps, PgStat_LocalState::shared_hash, PgStat_Snapshot::slru, PgStat_LocalState::snapshot, PgStat_KindInfo::to_serialized_name, PgStat_Snapshot::wal, write_chunk(), and write_chunk_s.

Referenced by pgstat_before_server_shutdown().

read_chunk()

static bool read_chunk ( FILE *  fpin, void *  ptr, size_t  len  )

static

Definition at line 1469 of file pgstat.c.

{
    return fread(ptr, 1, len, fpin) == len;
}

References len.

Referenced by pgstat_read_statsfile().

write_chunk()

static void write_chunk ( FILE *  fpout, void *  ptr, size_t  len  )

static

Definition at line 1291 of file pgstat.c.

{
    int         rc;
 
    rc = fwrite(ptr, len, 1, fpout);
 
    /* we'll check for errors with ferror once at the end */
    (void) rc;
}

References len.

Referenced by pgstat_write_statsfile().

Variable Documentation

force_stats_snapshot_clear

bool force_stats_snapshot_clear = false

static

Definition at line 234 of file pgstat.c.

Referenced by assign_stats_fetch_consistency(), pgstat_clear_snapshot(), pgstat_get_stat_snapshot_timestamp(), and pgstat_prep_snapshot().

pgstat_fetch_consistency

int pgstat_fetch_consistency = PGSTAT_FETCH_CONSISTENCY_CACHE

Definition at line 188 of file pgstat.c.

Referenced by assign_stats_fetch_consistency(), pgstat_build_snapshot(), pgstat_build_snapshot_fixed(), pgstat_fetch_entry(), pgstat_prep_snapshot(), pgstat_snapshot_fixed(), and pgstat_write_statsfile().

pgstat_kind_infos

const PgStat_KindInfo pgstat_kind_infos[PGSTAT_NUM_KINDS]

static

Definition at line 260 of file pgstat.c.

Referenced by pgstat_get_kind_from_str(), and pgstat_get_kind_info().

pgstat_track_counts

bool pgstat_track_counts = false

Definition at line 187 of file pgstat.c.

Referenced by autovac_init(), AutoVacuumingActive(), pgstat_init_relation(), pgstat_report_analyze(), pgstat_report_checksum_failures_in_db(), pgstat_report_deadlock(), pgstat_report_recovery_conflict(), pgstat_report_tempfile(), and pgstat_report_vacuum().

pgStatForceNextFlush

bool pgStatForceNextFlush = false

static

Definition at line 228 of file pgstat.c.

Referenced by pgstat_force_next_flush(), and pgstat_report_stat().

pgStatLocal

PgStat_LocalState pgStatLocal

Definition at line 196 of file pgstat.c.

Referenced by pgstat_acquire_entry_ref(), pgstat_archiver_reset_all_cb(), pgstat_archiver_snapshot_cb(), pgstat_attach_shmem(), pgstat_before_server_shutdown(), pgstat_bgwriter_reset_all_cb(), pgstat_bgwriter_snapshot_cb(), pgstat_build_snapshot(), pgstat_build_snapshot_fixed(), pgstat_checkpointer_reset_all_cb(), pgstat_checkpointer_snapshot_cb(), pgstat_clear_snapshot(), pgstat_detach_shmem(), pgstat_drop_all_entries(), pgstat_drop_database_and_contents(), pgstat_drop_entry(), pgstat_drop_entry_internal(), pgstat_fetch_entry(), pgstat_fetch_slru(), pgstat_fetch_stat_archiver(), pgstat_fetch_stat_bgwriter(), pgstat_fetch_stat_checkpointer(), pgstat_fetch_stat_io(), pgstat_fetch_stat_wal(), pgstat_flush_io(), pgstat_flush_wal(), pgstat_free_entry(), pgstat_gc_entry_refs(), pgstat_get_entry_ref(), pgstat_get_stat_snapshot_timestamp(), pgstat_init_entry(), pgstat_io_reset_all_cb(), pgstat_io_snapshot_cb(), pgstat_need_entry_refs_gc(), pgstat_prep_snapshot(), pgstat_read_statsfile(), pgstat_reinit_entry(), pgstat_release_entry_ref(), pgstat_report_archiver(), pgstat_report_bgwriter(), pgstat_report_checkpointer(), pgstat_report_stat(), pgstat_request_entry_refs_gc(), pgstat_reset_matching_entries(), pgstat_reset_slru_counter_internal(), pgstat_setup_shared_refs(), pgstat_slru_flush(), pgstat_slru_snapshot_cb(), pgstat_snapshot_fixed(), pgstat_wal_reset_all_cb(), pgstat_wal_snapshot_cb(), pgstat_write_statsfile(), and StatsShmemInit().

pgStatPending

dlist_head pgStatPending = DLIST_STATIC_INIT(pgStatPending)

static

Definition at line 221 of file pgstat.c.

Referenced by pgstat_flush_pending_entries(), pgstat_prep_pending_entry(), pgstat_report_stat(), and pgstat_shutdown_hook().

pgStatPendingContext

MemoryContext pgStatPendingContext = NULL

static

Definition at line 213 of file pgstat.c.

Referenced by pgstat_prep_pending_entry().