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apache / hawq / HAWQ-1075 / . / src / backend / postmaster / pgstat.c
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/* ----------
* pgstat.c
*
* All the statistics collector stuff hacked up in one big, ugly file.
*
* TODO: - Separate collector, postmaster and backend stuff
* into different files.
*
* - Add some automatic call for pgstat vacuuming.
*
* - Add a pgstat config column to pg_database, so this
* entire thing can be enabled/disabled on a per db basis.
*
* Copyright (c) 2001-2009, PostgreSQL Global Development Group
*
* $PostgreSQL: pgsql/src/backend/postmaster/pgstat.c,v 1.189 2009/06/11 14:49:01 momjian Exp $
* ----------
*/
#include "postgres.h"
#include <unistd.h>
#include <fcntl.h>
#include <sys/param.h>
#include <sys/time.h>
#include <sys/socket.h>
#include <netdb.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <signal.h>
#include <time.h>
#ifdef HAVE_POLL_H
#include <poll.h>
#endif
#ifdef HAVE_SYS_POLL_H
#include <sys/poll.h>
#endif
#include "pgstat.h"
#include "access/heapam.h"
#include "access/transam.h"
#include "access/twophase_rmgr.h"
#include "access/xact.h"
#include "catalog/pg_database.h"
#include "catalog/pg_proc.h"
#include "libpq/ip.h"
#include "libpq/libpq.h"
#include "libpq/pqsignal.h"
#include "mb/pg_wchar.h"
#include "miscadmin.h"
#include "executor/instrument.h"
#include "pg_trace.h"
#include "postmaster/autovacuum.h"
#include "postmaster/fork_process.h"
#include "postmaster/postmaster.h"
#include "storage/backendid.h"
#include "storage/fd.h"
#include "storage/ipc.h"
#include "storage/pg_shmem.h"
#include "storage/pmsignal.h"
#include "utils/guc.h"
#include "utils/memutils.h"
#include "utils/ps_status.h"
#include "utils/rel.h"
#include "utils/tqual.h"
#include "cdb/cdbvars.h"
// for mkdir
#include "sys/stat.h"
/* ----------
* Paths for the statistics files (relative to installation's $PGDATA).
* ----------
*/
#define PGSTAT_STAT_PERMANENT_FILENAME "global/pgstat.stat"
#define PGSTAT_STAT_PERMANENT_TMPFILE "global/pgstat.tmp"
/* ----------
* Timer definitions.
* ----------
*/
#define PGSTAT_STAT_INTERVAL 500 /* Minimum time between stats file
* updates; in milliseconds. */
#define PGSTAT_RETRY_DELAY 10 /* How long to wait between statistics
* update requests; in milliseconds. */
#define PGSTAT_MAX_WAIT_TIME 5000 /* Maximum time to wait for a stats
* file update; in milliseconds. */
#define PGSTAT_RESTART_INTERVAL 60 /* How often to attempt to restart a
* failed statistics collector; in
* seconds. */
#define PGSTAT_SELECT_TIMEOUT 2 /* How often to check for postmaster
* death; in seconds. */
#define PGSTAT_POLL_LOOP_COUNT (PGSTAT_MAX_WAIT_TIME / PGSTAT_RETRY_DELAY)
/* ----------
* The initial size hints for the hash tables used in the collector.
* ----------
*/
#define PGSTAT_DB_HASH_SIZE 16
#define PGSTAT_TAB_HASH_SIZE 512
#define PGSTAT_QUEUE_HASH_SIZE 8
#define PGSTAT_FUNCTION_HASH_SIZE 512
/* ----------
* GUC parameters
* ----------
*/
bool pgstat_track_activities = false;
bool pgstat_track_counts = false;
bool pgstat_collect_queuelevel = false;
int pgstat_track_functions = TRACK_FUNC_OFF;
int pgstat_track_activity_query_size = PGBE_ACTIVITY_SIZE;
/* ----------
* Built from GUC parameter
* ----------
*/
char *pgstat_stat_filename = NULL;
char *pgstat_stat_tmpname = NULL;
/*
* BgWriter global statistics counters (unused in other processes).
* Stored directly in a stats message structure so it can be sent
* without needing to copy things around. We assume this inits to zeroes.
*/
PgStat_MsgBgWriter BgWriterStats;
/* ----------
* Local data
* ----------
*/
NON_EXEC_STATIC int pgStatSock = -1;
static struct sockaddr_storage pgStatAddr;
static time_t last_pgstat_start_time;
static bool pgStatRunningInCollector = false;
/*
* Structures in which backends store per-table info that's waiting to be
* sent to the collector.
*
* NOTE: once allocated, TabStatusArray structures are never moved or deleted
* for the life of the backend. Also, we zero out the t_id fields of the
* contained PgStat_TableStatus structs whenever they are not actively in use.
* This allows relcache pgstat_info pointers to be treated as long-lived data,
* avoiding repeated searches in pgstat_initstats() when a relation is
* repeatedly opened during a transaction.
*/
#define TABSTAT_QUANTUM 100 /* we alloc this many at a time */
typedef struct TabStatusArray
{
struct TabStatusArray *tsa_next; /* link to next array, if any */
int tsa_used; /* # entries currently used */
PgStat_TableStatus tsa_entries[TABSTAT_QUANTUM]; /* per-table data */
} TabStatusArray;
static TabStatusArray *pgStatTabList = NULL;
/*
* Backends store per-function info that's waiting to be sent to the collector
* in this hash table (indexed by function OID).
*/
static HTAB *pgStatFunctions = NULL;
/*
* Indicates if backend has some function stats that it hasn't yet
* sent to the collector.
*/
static bool have_function_stats = false;
/*
* Tuple insertion/deletion counts for an open transaction can't be propagated
* into PgStat_TableStatus counters until we know if it is going to commit
* or abort. Hence, we keep these counts in per-subxact structs that live
* in TopTransactionContext. This data structure is designed on the assumption
* that subxacts won't usually modify very many tables.
*/
typedef struct PgStat_SubXactStatus
{
int nest_level; /* subtransaction nest level */
struct PgStat_SubXactStatus *prev; /* higher-level subxact if any */
PgStat_TableXactStatus *first; /* head of list for this subxact */
} PgStat_SubXactStatus;
static PgStat_SubXactStatus *pgStatXactStack = NULL;
static int pgStatXactCommit = 0;
static int pgStatXactRollback = 0;
/* Record that's written to 2PC state file when pgstat state is persisted */
typedef struct TwoPhasePgStatRecord
{
PgStat_Counter tuples_inserted; /* tuples inserted in xact */
PgStat_Counter tuples_deleted; /* tuples deleted in xact */
Oid t_id; /* table's OID */
bool t_shared; /* is it a shared catalog? */
} TwoPhasePgStatRecord;
/*
* Info about current "snapshot" of stats file
*/
static MemoryContext pgStatLocalContext = NULL;
static HTAB *pgStatDBHash = NULL;
static HTAB *pgStatQueueHash = NULL; /* GPDB */
static HTAB *localStatPortalHash = NULL; /* GPDB. per backend portal queue stats.*/
static PgBackendStatus *localBackendStatusTable = NULL;
static int localNumBackends = 0;
/*
* Cluster wide statistics, kept in the stats collector.
* Contains statistics that are not collected per database
* or per table.
*/
static PgStat_GlobalStats globalStats;
/* Last time the collector successfully wrote the stats file */
static TimestampTz last_statwrite;
/* Latest statistics request time from backends */
static TimestampTz last_statrequest;
static volatile bool need_exit = false;
static volatile bool got_SIGHUP = false;
/*
* Total time charged to functions so far in the current backend.
* We use this to help separate "self" and "other" time charges.
* (We assume this initializes to zero.)
*/
static instr_time total_func_time;
/* ----------
* Local function forward declarations
* ----------
*/
#ifdef EXEC_BACKEND
static pid_t pgstat_forkexec(void);
#endif
NON_EXEC_STATIC void PgstatCollectorMain(int argc, char *argv[]);
static void pgstat_exit(SIGNAL_ARGS);
static void pgstat_beshutdown_hook(int code, Datum arg);
static void pgstat_sighup_handler(SIGNAL_ARGS);
static PgStat_StatDBEntry *pgstat_get_db_entry(Oid databaseid, bool create);
static PgStat_StatQueueEntry *pgstat_get_queue_entry(Oid queueid, bool create); /*GPDB*/
static void pgstat_write_statsfile(bool permanent);
static HTAB *pgstat_read_statsfile(Oid onlydb, bool permanent);
static void backend_read_statsfile(void);
static void pgstat_read_current_status(void);
static void pgstat_send_tabstat(PgStat_MsgTabstat *tsmsg);
static void pgstat_send_funcstats(void);
static HTAB *pgstat_collect_oids(Oid catalogid);
static PgStat_TableStatus *get_tabstat_entry(Oid rel_id, bool isshared);
static void pgstat_setup_memcxt(void);
static void pgstat_setheader(PgStat_MsgHdr *hdr, StatMsgType mtype);
static void pgstat_send(void *msg, int len);
static void pgstat_recv_inquiry(PgStat_MsgInquiry *msg, int len);
static void pgstat_recv_tabstat(PgStat_MsgTabstat *msg, int len);
static void pgstat_recv_tabpurge(PgStat_MsgTabpurge *msg, int len);
static void pgstat_recv_dropdb(PgStat_MsgDropdb *msg, int len);
static void pgstat_recv_resetcounter(PgStat_MsgResetcounter *msg, int len);
static void pgstat_recv_autovac(PgStat_MsgAutovacStart *msg, int len);
static void pgstat_recv_vacuum(PgStat_MsgVacuum *msg, int len);
static void pgstat_recv_analyze(PgStat_MsgAnalyze *msg, int len);
static void pgstat_recv_queuestat(PgStat_MsgQueuestat *msg, int len); /* GPDB */
static void pgstat_recv_bgwriter(PgStat_MsgBgWriter *msg, int len);
static void pgstat_recv_funcstat(PgStat_MsgFuncstat *msg, int len);
static void pgstat_recv_funcpurge(PgStat_MsgFuncpurge *msg, int len);
/* ------------------------------------------------------------
* Public functions called from postmaster follow
* ------------------------------------------------------------
*/
/* ----------
* pgstat_init() -
*
* Called from postmaster at startup. Create the resources required
* by the statistics collector process. If unable to do so, do not
* fail --- better to let the postmaster start with stats collection
* disabled.
* ----------
*/
void
pgstat_init(void)
{
socklen_t alen;
struct addrinfo *addrs = NULL,
*addr,
hints;
int ret;
fd_set rset;
struct timeval tv;
char test_byte;
int sel_res;
int tries = 0;
#define TESTBYTEVAL ((char) 199)
/*
* Create stats temp directory if not present; ignore errors.
* This avoids the need to initdb... This is temporary code, and
* can be removed in the future, as initdb does this for us.
*/
mkdir("pg_stat_tmp", 0700);
/*
* Create the UDP socket for sending and receiving statistic messages
*/
hints.ai_flags = AI_PASSIVE;
hints.ai_family = PF_UNSPEC;
hints.ai_socktype = SOCK_DGRAM;
hints.ai_protocol = 0;
hints.ai_addrlen = 0;
hints.ai_addr = NULL;
hints.ai_canonname = NULL;
hints.ai_next = NULL;
ret = pg_getaddrinfo_all("localhost", NULL, &hints, &addrs);
if (ret || !addrs)
{
ereport(LOG,
(errmsg("could not resolve \"localhost\": %s",
gai_strerror(ret))));
goto startup_failed;
}
/*
* On some platforms, pg_getaddrinfo_all() may return multiple addresses
* only one of which will actually work (eg, both IPv6 and IPv4 addresses
* when kernel will reject IPv6). Worse, the failure may occur at the
* bind() or perhaps even connect() stage. So we must loop through the
* results till we find a working combination. We will generate LOG
* messages, but no error, for bogus combinations.
*/
for (addr = addrs; addr; addr = addr->ai_next)
{
#ifdef HAVE_UNIX_SOCKETS
/* Ignore AF_UNIX sockets, if any are returned. */
if (addr->ai_family == AF_UNIX)
continue;
#endif
if (++tries > 1)
ereport(LOG,
(errmsg("trying another address for the statistics collector")));
/*
* Create the socket.
*/
if ((pgStatSock = socket(addr->ai_family, SOCK_DGRAM, 0)) < 0)
{
ereport(LOG,
(errcode_for_socket_access(),
errmsg("could not create socket for statistics collector: %m")));
continue;
}
/*
* Bind it to a kernel assigned port on localhost and get the assigned
* port via getsockname().
*/
if (bind(pgStatSock, addr->ai_addr, addr->ai_addrlen) < 0)
{
ereport(LOG,
(errcode_for_socket_access(),
errmsg("could not bind socket for statistics collector: %m")));
closesocket(pgStatSock);
pgStatSock = -1;
continue;
}
alen = sizeof(pgStatAddr);
if (getsockname(pgStatSock, (struct sockaddr *) & pgStatAddr, &alen) < 0)
{
ereport(LOG,
(errcode_for_socket_access(),
errmsg("could not get address of socket for statistics collector: %m")));
closesocket(pgStatSock);
pgStatSock = -1;
continue;
}
/*
* Connect the socket to its own address. This saves a few cycles by
* not having to respecify the target address on every send. This also
* provides a kernel-level check that only packets from this same
* address will be received.
*/
if (connect(pgStatSock, (struct sockaddr *) & pgStatAddr, alen) < 0)
{
ereport(LOG,
(errcode_for_socket_access(),
errmsg("could not connect socket for statistics collector: %m")));
closesocket(pgStatSock);
pgStatSock = -1;
continue;
}
/*
* Try to send and receive a one-byte test message on the socket. This
* is to catch situations where the socket can be created but will not
* actually pass data (for instance, because kernel packet filtering
* rules prevent it).
*/
test_byte = TESTBYTEVAL;
retry1:
if (send(pgStatSock, &test_byte, 1, 0) != 1)
{
if (errno == EINTR)
goto retry1; /* if interrupted, just retry */
ereport(LOG,
(errcode_for_socket_access(),
errmsg("could not send test message on socket for statistics collector: %m")));
closesocket(pgStatSock);
pgStatSock = -1;
continue;
}
/*
* There could possibly be a little delay before the message can be
* received. We arbitrarily allow up to half a second before deciding
* it's broken.
*/
for (;;) /* need a loop to handle EINTR */
{
FD_ZERO(&rset);
FD_SET (pgStatSock, &rset);
tv.tv_sec = 0;
tv.tv_usec = 500000;
sel_res = select(pgStatSock + 1, &rset, NULL, NULL, &tv);
if (sel_res >= 0 || errno != EINTR)
break;
}
if (sel_res < 0)
{
ereport(LOG,
(errcode_for_socket_access(),
errmsg("select() failed in statistics collector: %m")));
closesocket(pgStatSock);
pgStatSock = -1;
continue;
}
if (sel_res == 0 || !FD_ISSET(pgStatSock, &rset))
{
/*
* This is the case we actually think is likely, so take pains to
* give a specific message for it.
*
* errno will not be set meaningfully here, so don't use it.
*/
ereport(LOG,
(errcode(ERRCODE_CONNECTION_FAILURE),
errmsg("test message did not get through on socket for statistics collector")));
closesocket(pgStatSock);
pgStatSock = -1;
continue;
}
test_byte++; /* just make sure variable is changed */
retry2:
if (recv(pgStatSock, &test_byte, 1, 0) != 1)
{
if (errno == EINTR)
goto retry2; /* if interrupted, just retry */
ereport(LOG,
(errcode_for_socket_access(),
errmsg("could not receive test message on socket for statistics collector: %m")));
closesocket(pgStatSock);
pgStatSock = -1;
continue;
}
if (test_byte != TESTBYTEVAL) /* strictly paranoia ... */
{
ereport(LOG,
(errcode(ERRCODE_INTERNAL_ERROR),
errmsg("incorrect test message transmission on socket for statistics collector")));
closesocket(pgStatSock);
pgStatSock = -1;
continue;
}
/* If we get here, we have a working socket */
break;
}
/* Did we find a working address? */
if (!addr || pgStatSock < 0)
goto startup_failed;
/*
* Set the socket to non-blocking IO. This ensures that if the collector
* falls behind, statistics messages will be discarded; backends won't
* block waiting to send messages to the collector.
*/
if (!pg_set_noblock(pgStatSock))
{
ereport(LOG,
(errcode_for_socket_access(),
errmsg("could not set statistics collector socket to nonblocking mode: %m")));
goto startup_failed;
}
pg_freeaddrinfo_all(hints.ai_family, addrs);
return;
startup_failed:
ereport(LOG,
(errmsg("disabling statistics collector for lack of working socket")));
if (addrs)
pg_freeaddrinfo_all(hints.ai_family, addrs);
if (pgStatSock >= 0)
closesocket(pgStatSock);
pgStatSock = -1;
/*
* Adjust GUC variables to suppress useless activity, and for debugging
* purposes (seeing track_counts off is a clue that we failed here). We
* use PGC_S_OVERRIDE because there is no point in trying to turn it back
* on from postgresql.conf without a restart.
*/
SetConfigOption("track_counts", "off", PGC_INTERNAL, PGC_S_OVERRIDE);
pgstat_track_counts = false;
pgstat_collect_queuelevel = false;
}
/*
* pgstat_reset_all() -
*
* Remove the stats file. This is currently used only if WAL
* recovery is needed after a crash.
*/
void
pgstat_reset_all(void)
{
unlink(pgstat_stat_filename);
unlink(PGSTAT_STAT_PERMANENT_FILENAME);
}
#ifdef EXEC_BACKEND
/*
* pgstat_forkexec() -
*
* Format up the arglist for, then fork and exec, statistics collector process
*/
static pid_t
pgstat_forkexec(void)
{
char *av[10];
int ac = 0;
av[ac++] = "postgres";
av[ac++] = "--forkcol";
av[ac++] = NULL; /* filled in by postmaster_forkexec */
av[ac] = NULL;
Assert(ac < lengthof(av));
return postmaster_forkexec(ac, av);
}
#endif /* EXEC_BACKEND */
/*
* pgstat_start() -
*
* Called from postmaster at startup or after an existing collector
* died. Attempt to fire up a fresh statistics collector.
*
* Returns PID of child process, or 0 if fail.
*
* Note: if fail, we will be called again from the postmaster main loop.
*/
int
pgstat_start(void)
{
time_t curtime;
pid_t pgStatPid;
/*
* Check that the socket is there, else pgstat_init failed and we can do
* nothing useful.
*/
if (pgStatSock < 0)
return 0;
/*
* Do nothing if too soon since last collector start. This is a safety
* valve to protect against continuous respawn attempts if the collector
* is dying immediately at launch. Note that since we will be re-called
* from the postmaster main loop, we will get another chance later.
*/
curtime = time(NULL);
if ((unsigned int) (curtime - last_pgstat_start_time) <
(unsigned int) PGSTAT_RESTART_INTERVAL)
return 0;
last_pgstat_start_time = curtime;
/*
* Okay, fork off the collector.
*/
#ifdef EXEC_BACKEND
switch ((pgStatPid = pgstat_forkexec()))
#else
switch ((pgStatPid = fork_process()))
#endif
{
case -1:
ereport(LOG,
(errmsg("could not fork statistics collector: %m")));
return 0;
#ifndef EXEC_BACKEND
case 0:
/* in postmaster child ... */
/* Close the postmaster's sockets */
ClosePostmasterPorts(false);
/* Lose the postmaster's on-exit routines */
on_exit_reset();
/* Drop our connection to postmaster's shared memory, as well */
PGSharedMemoryDetach();
PgstatCollectorMain(0, NULL);
break;
#endif
default:
return (int) pgStatPid;
}
/* shouldn't get here */
return 0;
}
void
allow_immediate_pgstat_restart(void)
{
last_pgstat_start_time = 0;
}
/* ------------------------------------------------------------
* Public functions used by backends follow
*------------------------------------------------------------
*/
/* ----------
* pgstat_report_stat() -
*
* Called from tcop/postgres.c to send the so far collected per-table
* and function usage statistics to the collector. Note that this is
* called only when not within a transaction, so it is fair to use
* transaction stop time as an approximation of current time.
* ----------
*/
void
pgstat_report_stat(bool force)
{
/* we assume this inits to all zeroes: */
static const PgStat_TableCounts all_zeroes;
static TimestampTz last_report = 0;
TimestampTz now;
PgStat_MsgTabstat regular_msg;
PgStat_MsgTabstat shared_msg;
TabStatusArray *tsa;
int i;
/* Don't expend a clock check if nothing to do */
if ((pgStatTabList == NULL || pgStatTabList->tsa_used == 0)
&& !have_function_stats)
return;
/*
* Don't send a message unless it's been at least PGSTAT_STAT_INTERVAL
* msec since we last sent one, or the caller wants to force stats out.
*/
now = GetCurrentTransactionStopTimestamp();
if (!force &&
!TimestampDifferenceExceeds(last_report, now, PGSTAT_STAT_INTERVAL))
return;
last_report = now;
/*
* Scan through the TabStatusArray struct(s) to find tables that actually
* have counts, and build messages to send. We have to separate shared
* relations from regular ones because the databaseid field in the message
* header has to depend on that.
*/
regular_msg.m_databaseid = MyDatabaseId;
shared_msg.m_databaseid = InvalidOid;
regular_msg.m_nentries = 0;
shared_msg.m_nentries = 0;
for (tsa = pgStatTabList; tsa != NULL; tsa = tsa->tsa_next)
{
for (i = 0; i < tsa->tsa_used; i++)
{
PgStat_TableStatus *entry = &tsa->tsa_entries[i];
PgStat_MsgTabstat *this_msg;
PgStat_TableEntry *this_ent;
/* Shouldn't have any pending transaction-dependent counts */
Assert(entry->trans == NULL);
/*
* Ignore entries that didn't accumulate any actual counts, such
* as indexes that were opened by the planner but not used.
*/
if (memcmp(&entry->t_counts, &all_zeroes,
sizeof(PgStat_TableCounts)) == 0)
continue;
/*
* OK, insert data into the appropriate message, and send if full.
*/
this_msg = entry->t_shared ? &shared_msg : &regular_msg;
this_ent = &this_msg->m_entry[this_msg->m_nentries];
this_ent->t_id = entry->t_id;
memcpy(&this_ent->t_counts, &entry->t_counts,
sizeof(PgStat_TableCounts));
if (++this_msg->m_nentries >= PGSTAT_NUM_TABENTRIES)
{
pgstat_send_tabstat(this_msg);
this_msg->m_nentries = 0;
}
}
/* zero out TableStatus structs after use */
MemSet(tsa->tsa_entries, 0,
tsa->tsa_used * sizeof(PgStat_TableStatus));
tsa->tsa_used = 0;
}
/*
* Send partial messages. If force is true, make sure that any pending
* xact commit/abort gets counted, even if no table stats to send.
*/
if (regular_msg.m_nentries > 0 ||
(force && (pgStatXactCommit > 0 || pgStatXactRollback > 0)))
pgstat_send_tabstat(&regular_msg);
if (shared_msg.m_nentries > 0)
pgstat_send_tabstat(&shared_msg);
/* Now, send function statistics */
pgstat_send_funcstats();
}
/*
* Subroutine for pgstat_report_stat: finish and send a tabstat message
*/
static void
pgstat_send_tabstat(PgStat_MsgTabstat *tsmsg)
{
int n;
int len;
/* It's unlikely we'd get here with no socket, but maybe not impossible */
if (pgStatSock < 0)
return;
/*
* Report accumulated xact commit/rollback whenever we send a normal
* tabstat message
*/
if (OidIsValid(tsmsg->m_databaseid))
{
tsmsg->m_xact_commit = pgStatXactCommit;
tsmsg->m_xact_rollback = pgStatXactRollback;
pgStatXactCommit = 0;
pgStatXactRollback = 0;
}
else
{
tsmsg->m_xact_commit = 0;
tsmsg->m_xact_rollback = 0;
}
n = tsmsg->m_nentries;
len = offsetof(PgStat_MsgTabstat, m_entry[0]) +
n * sizeof(PgStat_TableEntry);
pgstat_setheader(&tsmsg->m_hdr, PGSTAT_MTYPE_TABSTAT);
pgstat_send(tsmsg, len);
}
/*
* Subroutine for pgstat_report_stat: populate and send a function stat message
*/
static void
pgstat_send_funcstats(void)
{
/* we assume this inits to all zeroes: */
static const PgStat_FunctionCounts all_zeroes;
PgStat_MsgFuncstat msg;
PgStat_BackendFunctionEntry *entry;
HASH_SEQ_STATUS fstat;
if (pgStatFunctions == NULL)
return;
pgstat_setheader(&msg.m_hdr, PGSTAT_MTYPE_FUNCSTAT);
msg.m_databaseid = MyDatabaseId;
msg.m_nentries = 0;
hash_seq_init(&fstat, pgStatFunctions);
while ((entry = (PgStat_BackendFunctionEntry *) hash_seq_search(&fstat)) != NULL)
{
PgStat_FunctionEntry *m_ent;
/* Skip it if no counts accumulated since last time */
if (memcmp(&entry->f_counts, &all_zeroes,
sizeof(PgStat_FunctionCounts)) == 0)
continue;
/* need to convert format of time accumulators */
m_ent = &msg.m_entry[msg.m_nentries];
m_ent->f_id = entry->f_id;
m_ent->f_numcalls = entry->f_counts.f_numcalls;
m_ent->f_time = INSTR_TIME_GET_MICROSEC(entry->f_counts.f_time);
m_ent->f_time_self = INSTR_TIME_GET_MICROSEC(entry->f_counts.f_time_self);
if (++msg.m_nentries >= PGSTAT_NUM_FUNCENTRIES)
{
pgstat_send(&msg, offsetof(PgStat_MsgFuncstat, m_entry[0]) +
msg.m_nentries * sizeof(PgStat_FunctionEntry));
msg.m_nentries = 0;
}
/* reset the entry's counts */
MemSet(&entry->f_counts, 0, sizeof(PgStat_FunctionCounts));
}
if (msg.m_nentries > 0)
pgstat_send(&msg, offsetof(PgStat_MsgFuncstat, m_entry[0]) +
msg.m_nentries * sizeof(PgStat_FunctionEntry));
have_function_stats = false;
}
/* ----------
* pgstat_vacuum_stat() -
*
* Will tell the collector about objects he can get rid of.
* ----------
*/
void
pgstat_vacuum_stat(void)
{
HTAB *htab;
PgStat_MsgTabpurge msg;
PgStat_MsgFuncpurge f_msg;
HASH_SEQ_STATUS hstat;
PgStat_StatDBEntry *dbentry;
PgStat_StatTabEntry *tabentry;
PgStat_StatFuncEntry *funcentry;
int len;
if (pgStatSock < 0)
return;
/*
* If not done for this transaction, read the statistics collector stats
* file into some hash tables.
*/
backend_read_statsfile();
/*
* Read pg_database and make a list of OIDs of all existing databases
*/
htab = pgstat_collect_oids(DatabaseRelationId);
/*
* Search the database hash table for dead databases and tell the
* collector to drop them.
*/
hash_seq_init(&hstat, pgStatDBHash);
while ((dbentry = (PgStat_StatDBEntry *) hash_seq_search(&hstat)) != NULL)
{
Oid dbid = dbentry->databaseid;
CHECK_FOR_INTERRUPTS();
/* the DB entry for shared tables (with InvalidOid) is never dropped */
if (OidIsValid(dbid) &&
hash_search(htab, (void *) &dbid, HASH_FIND, NULL) == NULL)
pgstat_drop_database(dbid);
}
/* Clean up */
hash_destroy(htab);
/*
* Lookup our own database entry; if not found, nothing more to do.
*/
dbentry = (PgStat_StatDBEntry *) hash_search(pgStatDBHash,
(void *) &MyDatabaseId,
HASH_FIND, NULL);
if (dbentry == NULL || dbentry->tables == NULL)
return;
/*
* Similarly to above, make a list of all known relations in this DB.
*/
htab = pgstat_collect_oids(RelationRelationId);
/*
* Initialize our messages table counter to zero
*/
msg.m_nentries = 0;
/*
* Check for all tables listed in stats hashtable if they still exist.
*/
hash_seq_init(&hstat, dbentry->tables);
while ((tabentry = (PgStat_StatTabEntry *) hash_seq_search(&hstat)) != NULL)
{
Oid tabid = tabentry->tableid;
CHECK_FOR_INTERRUPTS();
if (hash_search(htab, (void *) &tabid, HASH_FIND, NULL) != NULL)
continue;
/*
* Not there, so add this table's Oid to the message
*/
msg.m_tableid[msg.m_nentries++] = tabid;
/*
* If the message is full, send it out and reinitialize to empty
*/
if (msg.m_nentries >= PGSTAT_NUM_TABPURGE)
{
len = offsetof(PgStat_MsgTabpurge, m_tableid[0])
+msg.m_nentries * sizeof(Oid);
pgstat_setheader(&msg.m_hdr, PGSTAT_MTYPE_TABPURGE);
msg.m_databaseid = MyDatabaseId;
pgstat_send(&msg, len);
msg.m_nentries = 0;
}
}
/*
* Send the rest
*/
if (msg.m_nentries > 0)
{
len = offsetof(PgStat_MsgTabpurge, m_tableid[0])
+msg.m_nentries * sizeof(Oid);
pgstat_setheader(&msg.m_hdr, PGSTAT_MTYPE_TABPURGE);
msg.m_databaseid = MyDatabaseId;
pgstat_send(&msg, len);
}
/* Clean up */
hash_destroy(htab);
/*
* Now repeat the above steps for functions. However, we needn't bother
* in the common case where no function stats are being collected.
*/
if (dbentry->functions != NULL &&
hash_get_num_entries(dbentry->functions) > 0)
{
htab = pgstat_collect_oids(ProcedureRelationId);
pgstat_setheader(&f_msg.m_hdr, PGSTAT_MTYPE_FUNCPURGE);
f_msg.m_databaseid = MyDatabaseId;
f_msg.m_nentries = 0;
hash_seq_init(&hstat, dbentry->functions);
while ((funcentry = (PgStat_StatFuncEntry *) hash_seq_search(&hstat)) != NULL)
{
Oid funcid = funcentry->functionid;
CHECK_FOR_INTERRUPTS();
if (hash_search(htab, (void *) &funcid, HASH_FIND, NULL) != NULL)
continue;
/*
* Not there, so add this function's Oid to the message
*/
f_msg.m_functionid[f_msg.m_nentries++] = funcid;
/*
* If the message is full, send it out and reinitialize to empty
*/
if (f_msg.m_nentries >= PGSTAT_NUM_FUNCPURGE)
{
len = offsetof(PgStat_MsgFuncpurge, m_functionid[0])
+f_msg.m_nentries * sizeof(Oid);
pgstat_send(&f_msg, len);
f_msg.m_nentries = 0;
}
}
/*
* Send the rest
*/
if (f_msg.m_nentries > 0)
{
len = offsetof(PgStat_MsgFuncpurge, m_functionid[0])
+f_msg.m_nentries * sizeof(Oid);
pgstat_send(&f_msg, len);
}
hash_destroy(htab);
}
}
/* ----------
* pgstat_collect_oids() -
*
* Collect the OIDs of all objects listed in the specified system catalog
* into a temporary hash table. Caller should hash_destroy the result
* when done with it.
* ----------
*/
static HTAB *
pgstat_collect_oids(Oid catalogid)
{
HTAB *htab;
HASHCTL hash_ctl;
Relation rel;
HeapScanDesc scan;
HeapTuple tup;
memset(&hash_ctl, 0, sizeof(hash_ctl));
hash_ctl.keysize = sizeof(Oid);
hash_ctl.entrysize = sizeof(Oid);
hash_ctl.hash = oid_hash;
htab = hash_create("Temporary table of OIDs",
PGSTAT_TAB_HASH_SIZE,
&hash_ctl,
HASH_ELEM | HASH_FUNCTION);
rel = heap_open(catalogid, AccessShareLock);
scan = heap_beginscan(rel, SnapshotNow, 0, NULL);
while ((tup = heap_getnext(scan, ForwardScanDirection)) != NULL)
{
Oid thisoid = HeapTupleGetOid(tup);
CHECK_FOR_INTERRUPTS();
(void) hash_search(htab, (void *) &thisoid, HASH_ENTER, NULL);
}
heap_endscan(scan);
heap_close(rel, AccessShareLock);
return htab;
}
/* ----------
* pgstat_drop_database() -
*
* Tell the collector that we just dropped a database.
* (If the message gets lost, we will still clean the dead DB eventually
* via future invocations of pgstat_vacuum_stat().)
* ----------
*/
void
pgstat_drop_database(Oid databaseid)
{
PgStat_MsgDropdb msg;
if (pgStatSock < 0)
return;
pgstat_setheader(&msg.m_hdr, PGSTAT_MTYPE_DROPDB);
msg.m_databaseid = databaseid;
pgstat_send(&msg, sizeof(msg));
}
/* ----------
* pgstat_drop_relation() -
*
* Tell the collector that we just dropped a relation.
* (If the message gets lost, we will still clean the dead entry eventually
* via future invocations of pgstat_vacuum_stat().)
*
* Currently not used for lack of any good place to call it; we rely
* entirely on pgstat_vacuum_stat() to clean out stats for dead rels.
* ----------
*/
#ifdef NOT_USED
void
pgstat_drop_relation(Oid relid)
{
PgStat_MsgTabpurge msg;
int len;
if (pgStatSock < 0)
return;
msg.m_tableid[0] = relid;
msg.m_nentries = 1;
len = offsetof(PgStat_MsgTabpurge, m_tableid[0]) +sizeof(Oid);
pgstat_setheader(&msg.m_hdr, PGSTAT_MTYPE_TABPURGE);
msg.m_databaseid = MyDatabaseId;
pgstat_send(&msg, len);
}
#endif /* NOT_USED */
/* ----------
* pgstat_reset_counters() -
*
* Tell the statistics collector to reset counters for our database.
* ----------
*/
void
pgstat_reset_counters(void)
{
PgStat_MsgResetcounter msg;
if (pgStatSock < 0)
return;
if (!superuser())
ereport(ERROR,
(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
errmsg("must be superuser to reset statistics counters")));
pgstat_setheader(&msg.m_hdr, PGSTAT_MTYPE_RESETCOUNTER);
msg.m_databaseid = MyDatabaseId;
pgstat_send(&msg, sizeof(msg));
}
/* ----------
* pgstat_report_autovac() -
*
* Called from autovacuum.c to report startup of an autovacuum process.
* We are called before InitPostgres is done, so can't rely on MyDatabaseId;
* the db OID must be passed in, instead.
* ----------
*/
void
pgstat_report_autovac(Oid dboid)
{
PgStat_MsgAutovacStart msg;
if (pgStatSock < 0)
return;
pgstat_setheader(&msg.m_hdr, PGSTAT_MTYPE_AUTOVAC_START);
msg.m_databaseid = dboid;
msg.m_start_time = GetCurrentTimestamp();
pgstat_send(&msg, sizeof(msg));
}
/* ---------
* pgstat_report_vacuum() -
*
* Tell the collector about the table we just vacuumed.
* ---------
*/
void
pgstat_report_vacuum(Oid tableoid, bool shared, bool scanned_all,
bool analyze, PgStat_Counter tuples)
{
PgStat_MsgVacuum msg;
if (pgStatSock < 0 || !pgstat_track_counts)
return;
pgstat_setheader(&msg.m_hdr, PGSTAT_MTYPE_VACUUM);
msg.m_databaseid = shared ? InvalidOid : MyDatabaseId;
msg.m_tableoid = tableoid;
msg.m_scanned_all = scanned_all;
msg.m_analyze = analyze;
msg.m_autovacuum = IsAutoVacuumProcess(); /* is this autovacuum? */
msg.m_vacuumtime = GetCurrentTimestamp();
msg.m_tuples = tuples;
pgstat_send(&msg, sizeof(msg));
}
/* --------
* pgstat_report_analyze() -
*
* Tell the collector about the table we just analyzed.
* --------
*/
void
pgstat_report_analyze(Relation rel, PgStat_Counter livetuples,
PgStat_Counter deadtuples)
{
PgStat_MsgAnalyze msg;
if (pgStatSock < 0 || !pgstat_track_counts)
return;
/*
* Unlike VACUUM, ANALYZE might be running inside a transaction that has
* already inserted and/or deleted rows in the target table. ANALYZE will
* have counted such rows as live or dead respectively. Because we will
* report our counts of such rows at transaction end, we should subtract
* off these counts from what we send to the collector now, else they'll
* be double-counted after commit. (This approach also ensures that the
* collector ends up with the right numbers if we abort instead of
* committing.)
*/
if (rel->pgstat_info != NULL)
{
PgStat_TableXactStatus *trans;
for (trans = rel->pgstat_info->trans; trans; trans = trans->upper)
{
livetuples -= trans->tuples_inserted - trans->tuples_deleted;
deadtuples -= trans->tuples_deleted;
}
/* count stuff inserted by already-aborted subxacts, too */
deadtuples -= rel->pgstat_info->t_counts.t_new_dead_tuples;
/* Since ANALYZE's counts are estimates, we could have underflowed */
livetuples = Max(livetuples, 0);
deadtuples = Max(deadtuples, 0);
}
pgstat_setheader(&msg.m_hdr, PGSTAT_MTYPE_ANALYZE);
msg.m_databaseid = rel->rd_rel->relisshared ? InvalidOid : MyDatabaseId;
msg.m_tableoid = RelationGetRelid(rel);
msg.m_autovacuum = IsAutoVacuumProcess(); /* is this autovacuum? */
msg.m_analyzetime = GetCurrentTimestamp();
msg.m_live_tuples = livetuples;
msg.m_dead_tuples = deadtuples;
pgstat_send(&msg, sizeof(msg));
}
/* ----------
* pgstat_ping() -
*
* Send some junk data to the collector to increase traffic.
* ----------
*/
void
pgstat_ping(void)
{
PgStat_MsgDummy msg;
if (pgStatSock < 0)
return;
pgstat_setheader(&msg.m_hdr, PGSTAT_MTYPE_DUMMY);
pgstat_send(&msg, sizeof(msg));
}
/* ----------
* pgstat_send_inquiry() -
*
* Notify collector that we need fresh data.
* ts specifies the minimum acceptable timestamp for the stats file.
* ----------
*/
static void
pgstat_send_inquiry(TimestampTz ts)
{
PgStat_MsgInquiry msg;
pgstat_setheader(&msg.m_hdr, PGSTAT_MTYPE_INQUIRY);
msg.inquiry_time = ts;
pgstat_send(&msg, sizeof(msg));
}
/*
* Initialize function call usage data.
* Called by the executor before invoking a function.
*/
void
pgstat_init_function_usage(FunctionCallInfoData *fcinfo,
PgStat_FunctionCallUsage *fcu)
{
PgStat_BackendFunctionEntry *htabent;
bool found;
if (pgstat_track_functions <= fcinfo->flinfo->fn_stats)
{
/* stats not wanted */
fcu->fs = NULL;
return;
}
if (!pgStatFunctions)
{
/* First time through - initialize function stat table */
HASHCTL hash_ctl;
memset(&hash_ctl, 0, sizeof(hash_ctl));
hash_ctl.keysize = sizeof(Oid);
hash_ctl.entrysize = sizeof(PgStat_BackendFunctionEntry);
hash_ctl.hash = oid_hash;
pgStatFunctions = hash_create("Function stat entries",
PGSTAT_FUNCTION_HASH_SIZE,
&hash_ctl,
HASH_ELEM | HASH_FUNCTION);
}
/* Get the stats entry for this function, create if necessary */
htabent = hash_search(pgStatFunctions, &fcinfo->flinfo->fn_oid,
HASH_ENTER, &found);
if (!found)
MemSet(&htabent->f_counts, 0, sizeof(PgStat_FunctionCounts));
fcu->fs = &htabent->f_counts;
/* save stats for this function, later used to compensate for recursion */
fcu->save_f_time = htabent->f_counts.f_time;
/* save current backend-wide total time */
fcu->save_total = total_func_time;
/* get clock time as of function start */
INSTR_TIME_SET_CURRENT(fcu->f_start);
}
/*
* Calculate function call usage and update stat counters.
* Called by the executor after invoking a function.
*
* In the case of a set-returning function that runs in value-per-call mode,
* we will see multiple pgstat_init_function_usage/pgstat_end_function_usage
* calls for what the user considers a single call of the function. The
* finalize flag should be TRUE on the last call.
*/
void
pgstat_end_function_usage(PgStat_FunctionCallUsage *fcu, bool finalize)
{
PgStat_FunctionCounts *fs = fcu->fs;
instr_time f_total;
instr_time f_others;
instr_time f_self;
/* stats not wanted? */
if (fs == NULL)
return;
/* total elapsed time in this function call */
INSTR_TIME_SET_CURRENT(f_total);
INSTR_TIME_SUBTRACT(f_total, fcu->f_start);
/* self usage: elapsed minus anything already charged to other calls */
f_others = total_func_time;
INSTR_TIME_SUBTRACT(f_others, fcu->save_total);
f_self = f_total;
INSTR_TIME_SUBTRACT(f_self, f_others);
/* update backend-wide total time */
INSTR_TIME_ADD(total_func_time, f_self);
/*
* Compute the new total f_time as the total elapsed time added to the
* pre-call value of f_time. This is necessary to avoid double-counting
* any time taken by recursive calls of myself. (We do not need any
* similar kluge for self time, since that already excludes any recursive
* calls.)
*/
INSTR_TIME_ADD(f_total, fcu->save_f_time);
/* update counters in function stats table */
if (finalize)
fs->f_numcalls++;
fs->f_time = f_total;
INSTR_TIME_ADD(fs->f_time_self, f_self);
/* indicate that we have something to send */
have_function_stats = true;
}
/* ----------
* pgstat_initstats() -
*
* Initialize a relcache entry to count access statistics.
* Called whenever a relation is opened.
*
* We assume that a relcache entry's pgstat_info field is zeroed by
* relcache.c when the relcache entry is made; thereafter it is long-lived
* data. We can avoid repeated searches of the TabStatus arrays when the
* same relation is touched repeatedly within a transaction.
* ----------
*/
void
pgstat_initstats(Relation rel)
{
Oid rel_id = rel->rd_id;
char relkind = rel->rd_rel->relkind;
/* We only count stats for things that have storage */
if (!(relkind == RELKIND_RELATION ||
relkind == RELKIND_INDEX ||
relkind == RELKIND_TOASTVALUE ||
relkind == RELKIND_SEQUENCE))
{
rel->pgstat_info = NULL;
return;
}
if (pgStatSock < 0 || !pgstat_track_counts)
{
/* We're not counting at all */
rel->pgstat_info = NULL;
return;
}
/*
* If we already set up this relation in the current transaction, nothing
* to do.
*/
if (rel->pgstat_info != NULL &&
rel->pgstat_info->t_id == rel_id)
return;
/* Else find or make the PgStat_TableStatus entry, and update link */
rel->pgstat_info = get_tabstat_entry(rel_id, rel->rd_rel->relisshared);
}
/*
* get_tabstat_entry - find or create a PgStat_TableStatus entry for rel
*/
static PgStat_TableStatus *
get_tabstat_entry(Oid rel_id, bool isshared)
{
PgStat_TableStatus *entry;
TabStatusArray *tsa;
TabStatusArray *prev_tsa;
int i;
/*
* Search the already-used tabstat slots for this relation.
*/
prev_tsa = NULL;
for (tsa = pgStatTabList; tsa != NULL; prev_tsa = tsa, tsa = tsa->tsa_next)
{
for (i = 0; i < tsa->tsa_used; i++)
{
entry = &tsa->tsa_entries[i];
if (entry->t_id == rel_id)
return entry;
}
if (tsa->tsa_used < TABSTAT_QUANTUM)
{
/*
* It must not be present, but we found a free slot instead. Fine,
* let's use this one. We assume the entry was already zeroed,
* either at creation or after last use.
*/
entry = &tsa->tsa_entries[tsa->tsa_used++];
entry->t_id = rel_id;
entry->t_shared = isshared;
return entry;
}
}
/*
* We ran out of tabstat slots, so allocate more. Be sure they're zeroed.
*/
tsa = (TabStatusArray *) MemoryContextAllocZero(TopMemoryContext,
sizeof(TabStatusArray));
if (prev_tsa)
prev_tsa->tsa_next = tsa;
else
pgStatTabList = tsa;
/*
* Use the first entry of the new TabStatusArray.
*/
entry = &tsa->tsa_entries[tsa->tsa_used++];
entry->t_id = rel_id;
entry->t_shared = isshared;
return entry;
}
/*
* get_tabstat_stack_level - add a new (sub)transaction stack entry if needed
*/
static PgStat_SubXactStatus *
get_tabstat_stack_level(int nest_level)
{
PgStat_SubXactStatus *xact_state;
xact_state = pgStatXactStack;
if (xact_state == NULL || xact_state->nest_level != nest_level)
{
xact_state = (PgStat_SubXactStatus *)
MemoryContextAlloc(TopTransactionContext,
sizeof(PgStat_SubXactStatus));
xact_state->nest_level = nest_level;
xact_state->prev = pgStatXactStack;
xact_state->first = NULL;
pgStatXactStack = xact_state;
}
return xact_state;
}
/*
* add_tabstat_xact_level - add a new (sub)transaction state record
*/
static void
add_tabstat_xact_level(PgStat_TableStatus *pgstat_info, int nest_level)
{
PgStat_SubXactStatus *xact_state;
PgStat_TableXactStatus *trans;
/*
* If this is the first rel to be modified at the current nest level, we
* first have to push a transaction stack entry.
*/
xact_state = get_tabstat_stack_level(nest_level);
/* Now make a per-table stack entry */
trans = (PgStat_TableXactStatus *)
MemoryContextAllocZero(TopTransactionContext,
sizeof(PgStat_TableXactStatus));
trans->nest_level = nest_level;
trans->upper = pgstat_info->trans;
trans->parent = pgstat_info;
trans->next = xact_state->first;
xact_state->first = trans;
pgstat_info->trans = trans;
}
/*
* pgstat_count_heap_insert - count a tuple insertion
*/
void
pgstat_count_heap_insert(Relation rel)
{
PgStat_TableStatus *pgstat_info = rel->pgstat_info;
if (pgstat_track_counts && pgstat_info != NULL)
{
int nest_level = GetCurrentTransactionNestLevel();
/* t_tuples_inserted is nontransactional, so just advance it */
pgstat_info->t_counts.t_tuples_inserted++;
/* We have to log the transactional effect at the proper level */
if (pgstat_info->trans == NULL ||
pgstat_info->trans->nest_level != nest_level)
add_tabstat_xact_level(pgstat_info, nest_level);
pgstat_info->trans->tuples_inserted++;
}
}
/*
* pgstat_count_heap_update - count a tuple update
*/
void
pgstat_count_heap_update(Relation rel, bool hot)
{
PgStat_TableStatus *pgstat_info = rel->pgstat_info;
if (pgstat_track_counts && pgstat_info != NULL)
{
int nest_level = GetCurrentTransactionNestLevel();
/* t_tuples_updated is nontransactional, so just advance it */
pgstat_info->t_counts.t_tuples_updated++;
/* ditto for the hot_update counter */
if (hot)
pgstat_info->t_counts.t_tuples_hot_updated++;
/* We have to log the transactional effect at the proper level */
if (pgstat_info->trans == NULL ||
pgstat_info->trans->nest_level != nest_level)
add_tabstat_xact_level(pgstat_info, nest_level);
/* An UPDATE both inserts a new tuple and deletes the old */
pgstat_info->trans->tuples_inserted++;
pgstat_info->trans->tuples_deleted++;
}
}
/*
* pgstat_count_heap_delete - count a tuple deletion
*/
void
pgstat_count_heap_delete(Relation rel)
{
PgStat_TableStatus *pgstat_info = rel->pgstat_info;
if (pgstat_track_counts && pgstat_info != NULL)
{
int nest_level = GetCurrentTransactionNestLevel();
/* t_tuples_deleted is nontransactional, so just advance it */
pgstat_info->t_counts.t_tuples_deleted++;
/* We have to log the transactional effect at the proper level */
if (pgstat_info->trans == NULL ||
pgstat_info->trans->nest_level != nest_level)
add_tabstat_xact_level(pgstat_info, nest_level);
pgstat_info->trans->tuples_deleted++;
}
}
/*
* pgstat_update_heap_dead_tuples - update dead-tuples count
*
* The semantics of this are that we are reporting the nontransactional
* recovery of "delta" dead tuples; so t_new_dead_tuples decreases
* rather than increasing, and the change goes straight into the per-table
* counter, not into transactional state.
*/
void
pgstat_update_heap_dead_tuples(Relation rel, int delta)
{
PgStat_TableStatus *pgstat_info = rel->pgstat_info;
if (pgstat_track_counts && pgstat_info != NULL)
pgstat_info->t_counts.t_new_dead_tuples -= delta;
}
/* ----------
* AtEOXact_PgStat
*
* Called from access/transam/xact.c at top-level transaction commit/abort.
* ----------
*/
void
AtEOXact_PgStat(bool isCommit)
{
PgStat_SubXactStatus *xact_state;
/*
* Count transaction commit or abort. (We use counters, not just bools,
* in case the reporting message isn't sent right away.)
*/
if (isCommit)
pgStatXactCommit++;
else
pgStatXactRollback++;
/*
* Transfer transactional insert/update counts into the base tabstat
* entries. We don't bother to free any of the transactional state, since
* it's all in TopTransactionContext and will go away anyway.
*/
xact_state = pgStatXactStack;
if (xact_state != NULL)
{
PgStat_TableXactStatus *trans;
Assert(xact_state->nest_level == 1);
Assert(xact_state->prev == NULL);
for (trans = xact_state->first; trans != NULL; trans = trans->next)
{
PgStat_TableStatus *tabstat;
Assert(trans->nest_level == 1);
Assert(trans->upper == NULL);
tabstat = trans->parent;
Assert(tabstat->trans == trans);
if (isCommit)
{
tabstat->t_counts.t_new_live_tuples +=
trans->tuples_inserted - trans->tuples_deleted;
tabstat->t_counts.t_new_dead_tuples += trans->tuples_deleted;
}
else
{
/* inserted tuples are dead, deleted tuples are unaffected */
tabstat->t_counts.t_new_dead_tuples += trans->tuples_inserted;
}
tabstat->trans = NULL;
}
}
pgStatXactStack = NULL;
/* Make sure any stats snapshot is thrown away */
pgstat_clear_snapshot();
}
/* ----------
* AtEOSubXact_PgStat
*
* Called from access/transam/xact.c at subtransaction commit/abort.
* ----------
*/
void
AtEOSubXact_PgStat(bool isCommit, int nestDepth)
{
PgStat_SubXactStatus *xact_state;
/*
* Transfer transactional insert/update counts into the next higher
* subtransaction state.
*/
xact_state = pgStatXactStack;
if (xact_state != NULL &&
xact_state->nest_level >= nestDepth)
{
PgStat_TableXactStatus *trans;
PgStat_TableXactStatus *next_trans;
/* delink xact_state from stack immediately to simplify reuse case */
pgStatXactStack = xact_state->prev;
for (trans = xact_state->first; trans != NULL; trans = next_trans)
{
PgStat_TableStatus *tabstat;
next_trans = trans->next;
Assert(trans->nest_level == nestDepth);
tabstat = trans->parent;
Assert(tabstat->trans == trans);
if (isCommit)
{
if (trans->upper && trans->upper->nest_level == nestDepth - 1)
{
trans->upper->tuples_inserted += trans->tuples_inserted;
trans->upper->tuples_deleted += trans->tuples_deleted;
tabstat->trans = trans->upper;
pfree(trans);
}
else
{
/*
* When there isn't an immediate parent state, we can just
* reuse the record instead of going through a
* palloc/pfree pushup (this works since it's all in
* TopTransactionContext anyway). We have to re-link it
* into the parent level, though, and that might mean
* pushing a new entry into the pgStatXactStack.
*/
PgStat_SubXactStatus *upper_xact_state;
upper_xact_state = get_tabstat_stack_level(nestDepth - 1);
trans->next = upper_xact_state->first;
upper_xact_state->first = trans;
trans->nest_level = nestDepth - 1;
}
}
else
{
/*
* On abort, inserted tuples are dead (and can be bounced out
* to the top-level tabstat), deleted tuples are unaffected
*/
tabstat->t_counts.t_new_dead_tuples += trans->tuples_inserted;
tabstat->trans = trans->upper;
pfree(trans);
}
}
pfree(xact_state);
}
}
/*
* AtPrepare_PgStat
* Save the transactional stats state at 2PC transaction prepare.
*
* In this phase we just generate 2PC records for all the pending
* transaction-dependent stats work.
*/
void
AtPrepare_PgStat(void)
{
PgStat_SubXactStatus *xact_state;
xact_state = pgStatXactStack;
if (xact_state != NULL)
{
PgStat_TableXactStatus *trans;
Assert(xact_state->nest_level == 1);
Assert(xact_state->prev == NULL);
for (trans = xact_state->first; trans != NULL; trans = trans->next)
{
PgStat_TableStatus *tabstat;
TwoPhasePgStatRecord record;
Assert(trans->nest_level == 1);
Assert(trans->upper == NULL);
tabstat = trans->parent;
Assert(tabstat->trans == trans);
record.tuples_inserted = trans->tuples_inserted;
record.tuples_deleted = trans->tuples_deleted;
record.t_id = tabstat->t_id;
record.t_shared = tabstat->t_shared;
RegisterTwoPhaseRecord(TWOPHASE_RM_PGSTAT_ID, 0,
&record, sizeof(TwoPhasePgStatRecord));
}
}
}
/*
* PostPrepare_PgStat
* Clean up after successful PREPARE.
*
* All we need do here is unlink the transaction stats state from the
* nontransactional state. The nontransactional action counts will be
* reported to the stats collector immediately, while the effects on live
* and dead tuple counts are preserved in the 2PC state file.
*
* Note: AtEOXact_PgStat is not called during PREPARE.
*/
void
PostPrepare_PgStat(void)
{
PgStat_SubXactStatus *xact_state;
/*
* We don't bother to free any of the transactional state, since it's all
* in TopTransactionContext and will go away anyway.
*/
xact_state = pgStatXactStack;
if (xact_state != NULL)
{
PgStat_TableXactStatus *trans;
for (trans = xact_state->first; trans != NULL; trans = trans->next)
{
PgStat_TableStatus *tabstat;
tabstat = trans->parent;
tabstat->trans = NULL;
}
}
pgStatXactStack = NULL;
/* Make sure any stats snapshot is thrown away */
pgstat_clear_snapshot();
}
/*
* 2PC processing routine for COMMIT PREPARED case.
*
* Load the saved counts into our local pgstats state.
*/
void
pgstat_twophase_postcommit(TransactionId xid, uint16 info,
void *recdata, uint32 len)
{
TwoPhasePgStatRecord *rec = (TwoPhasePgStatRecord *) recdata;
PgStat_TableStatus *pgstat_info;
/* Find or create a tabstat entry for the rel */
pgstat_info = get_tabstat_entry(rec->t_id, rec->t_shared);
pgstat_info->t_counts.t_new_live_tuples +=
rec->tuples_inserted - rec->tuples_deleted;
pgstat_info->t_counts.t_new_dead_tuples += rec->tuples_deleted;
}
/*
* 2PC processing routine for ROLLBACK PREPARED case.
*
* Load the saved counts into our local pgstats state, but treat them
* as aborted.
*/
void
pgstat_twophase_postabort(TransactionId xid, uint16 info,
void *recdata, uint32 len)
{
TwoPhasePgStatRecord *rec = (TwoPhasePgStatRecord *) recdata;
PgStat_TableStatus *pgstat_info;
/* Find or create a tabstat entry for the rel */
pgstat_info = get_tabstat_entry(rec->t_id, rec->t_shared);
/* inserted tuples are dead, deleted tuples are no-ops */
pgstat_info->t_counts.t_new_dead_tuples += rec->tuples_inserted;
}
/* ----------
* pgstat_fetch_stat_dbentry() -
*
* Support function for the SQL-callable pgstat* functions. Returns
* the collected statistics for one database or NULL. NULL doesn't mean
* that the database doesn't exist, it is just not yet known by the
* collector, so the caller is better off to report ZERO instead.
* ----------
*/
PgStat_StatDBEntry *
pgstat_fetch_stat_dbentry(Oid dbid)
{
/*
* If not done for this transaction, read the statistics collector stats
* file into some hash tables.
*/
backend_read_statsfile();
/*
* Lookup the requested database; return NULL if not found
*/
return (PgStat_StatDBEntry *) hash_search(pgStatDBHash,
(void *) &dbid,
HASH_FIND, NULL);
}
/* ----------
* pgstat_fetch_stat_tabentry() -
*
* Support function for the SQL-callable pgstat* functions. Returns
* the collected statistics for one table or NULL. NULL doesn't mean
* that the table doesn't exist, it is just not yet known by the
* collector, so the caller is better off to report ZERO instead.
* ----------
*/
PgStat_StatTabEntry *
pgstat_fetch_stat_tabentry(Oid relid)
{
Oid dbid;
PgStat_StatDBEntry *dbentry;
PgStat_StatTabEntry *tabentry;
/*
* If not done for this transaction, read the statistics collector stats
* file into some hash tables.
*/
backend_read_statsfile();
/*
* Lookup our database, then look in its table hash table.
*/
dbid = MyDatabaseId;
dbentry = (PgStat_StatDBEntry *) hash_search(pgStatDBHash,
(void *) &dbid,
HASH_FIND, NULL);
if (dbentry != NULL && dbentry->tables != NULL)
{
tabentry = (PgStat_StatTabEntry *) hash_search(dbentry->tables,
(void *) &relid,
HASH_FIND, NULL);
if (tabentry)
return tabentry;
}
/*
* If we didn't find it, maybe it's a shared table.
*/
dbid = InvalidOid;
dbentry = (PgStat_StatDBEntry *) hash_search(pgStatDBHash,
(void *) &dbid,
HASH_FIND, NULL);
if (dbentry != NULL && dbentry->tables != NULL)
{
tabentry = (PgStat_StatTabEntry *) hash_search(dbentry->tables,
(void *) &relid,
HASH_FIND, NULL);
if (tabentry)
return tabentry;
}
return NULL;
}
/* ----------
* pgstat_fetch_stat_funcentry() -
*
* Support function for the SQL-callable pgstat* functions. Returns
* the collected statistics for one function or NULL.
* ----------
*/
PgStat_StatFuncEntry *
pgstat_fetch_stat_funcentry(Oid func_id)
{
PgStat_StatDBEntry *dbentry;
PgStat_StatFuncEntry *funcentry = NULL;
/* load the stats file if needed */
backend_read_statsfile();
/* Lookup our database, then find the requested function. */
dbentry = pgstat_fetch_stat_dbentry(MyDatabaseId);
if (dbentry != NULL && dbentry->functions != NULL)
{
funcentry = (PgStat_StatFuncEntry *) hash_search(dbentry->functions,
(void *) &func_id,
HASH_FIND, NULL);
}
return funcentry;
}
/* ----------
* pgstat_fetch_stat_beentry() -
*
* Support function for the SQL-callable pgstat* functions. Returns
* our local copy of the current-activity entry for one backend.
*
* NB: caller is responsible for a check if the user is permitted to see
* this info (especially the querystring).
* ----------
*/
PgBackendStatus *
pgstat_fetch_stat_beentry(int beid)
{
pgstat_read_current_status();
if (beid < 1 || beid > localNumBackends)
return NULL;
return &localBackendStatusTable[beid - 1];
}
/* ----------
* pgstat_fetch_stat_numbackends() -
*
* Support function for the SQL-callable pgstat* functions. Returns
* the maximum current backend id.
* ----------
*/
int
pgstat_fetch_stat_numbackends(void)
{
pgstat_read_current_status();
return localNumBackends;
}
/*
* ---------
* pgstat_fetch_global() -
*
* Support function for the SQL-callable pgstat* functions. Returns
* a pointer to the global statistics struct.
* ---------
*/
PgStat_GlobalStats *
pgstat_fetch_global(void)
{
backend_read_statsfile();
return &globalStats;
}
/* ------------------------------------------------------------
* Functions for management of the shared-memory PgBackendStatus array
* ------------------------------------------------------------
*/
static PgBackendStatus *BackendStatusArray = NULL;
static PgBackendStatus *MyBEEntry = NULL;
static char *BackendAppnameBuffer = NULL;
static char *BackendActivityBuffer = NULL;
/*
* Report shared-memory space needed by CreateSharedBackendStatus.
*/
Size
BackendStatusShmemSize(void)
{
Size size;
size = mul_size(sizeof(PgBackendStatus), MaxBackends);
size = add_size(size,
mul_size(NAMEDATALEN, MaxBackends));
size = add_size(size,
mul_size(pgstat_track_activity_query_size, MaxBackends));
return size;
}
/*
* Initialize the shared status array and activity/appname string buffers
* during postmaster startup.
*/
void
CreateSharedBackendStatus(void)
{
Size size;
bool found;
int i;
char *buffer;
/* Create or attach to the shared array */
size = mul_size(sizeof(PgBackendStatus), MaxBackends);
BackendStatusArray = (PgBackendStatus *)
ShmemInitStruct("Backend Status Array", size, &found);
if (!found)
{
/*
* We're the first - initialize.
*/
MemSet(BackendStatusArray, 0, size);
}
/* Create or attach to the shared appname buffer */
size = mul_size(NAMEDATALEN, MaxBackends);
BackendAppnameBuffer = (char *)
ShmemInitStruct("Backend Application Name Buffer", size, &found);
if (!found)
{
MemSet(BackendAppnameBuffer, 0, size);
/* Initialize st_appname pointers. */
buffer = BackendAppnameBuffer;
for (i = 0; i < MaxBackends; i++)
{
BackendStatusArray[i].st_appname = buffer;
buffer += NAMEDATALEN;
}
}
/* Create or attach to the shared activity buffer */
size = mul_size(pgstat_track_activity_query_size, MaxBackends);
BackendActivityBuffer = (char *)
ShmemInitStruct("Backend Activity Buffer", size, &found);
if (!found)
{
MemSet(BackendActivityBuffer, 0, size);
/* Initialize st_activity pointers. */
buffer = BackendActivityBuffer;
for (i = 0; i < MaxBackends; i++)
{
BackendStatusArray[i].st_activity = buffer;
buffer += pgstat_track_activity_query_size;
}
}
}
/* ----------
* pgstat_initialize() -
*
* Initialize pgstats state, and set up our on-proc-exit hook.
* Called from InitPostgres. MyBackendId must be set,
* but we must not have started any transaction yet (since the
* exit hook must run after the last transaction exit).
* NOTE: MyDatabaseId isn't set yet; so the shutdown hook has to be careful.
* ----------
*/
void
pgstat_initialize(void)
{
/* Initialize MyBEEntry */
Assert(MyBackendId >= 1 && MyBackendId <= MaxBackends);
MyBEEntry = &BackendStatusArray[MyBackendId - 1];
/* Set up a process-exit hook to clean up */
on_shmem_exit(pgstat_beshutdown_hook, 0);
}
/* ----------
* pgstat_bestart() -
*
* Initialize this backend's entry in the PgBackendStatus array.
* Called from InitPostgres.
* MyDatabaseId, session userid, and application_name must be set
* (hence, this cannot be combined with pgstat_initialize).
* ----------
*/
void
pgstat_bestart(void)
{
TimestampTz proc_start_timestamp;
Oid userid;
SockAddr clientaddr;
volatile PgBackendStatus *beentry;
/*
* To minimize the time spent modifying the PgBackendStatus entry, fetch
* all the needed data first.
*
* If we have a MyProcPort, use its session start time (for consistency,
* and to save a kernel call).
*/
if (MyProcPort)
proc_start_timestamp = MyProcPort->SessionStartTime;
else
proc_start_timestamp = GetCurrentTimestamp();
userid = GetSessionUserId();
/*
* We may not have a MyProcPort (eg, if this is the autovacuum process).
* If so, use all-zeroes client address, which is dealt with specially in
* pg_stat_get_backend_client_addr and pg_stat_get_backend_client_port.
*/
if (MyProcPort)
memcpy(&clientaddr, &MyProcPort->raddr, sizeof(clientaddr));
else
MemSet(&clientaddr, 0, sizeof(clientaddr));
/*
* Initialize my status entry, following the protocol of bumping
* st_changecount before and after; and make sure it's even afterwards. We
* use a volatile pointer here to ensure the compiler doesn't try to get
* cute.
*/
beentry = MyBEEntry;
do
{
beentry->st_changecount++;
} while ((beentry->st_changecount & 1) == 0);
beentry->st_procpid = MyProcPid;
beentry->st_proc_start_timestamp = proc_start_timestamp;
beentry->st_activity_start_timestamp = 0;
beentry->st_xact_start_timestamp = 0;
beentry->st_databaseid = MyDatabaseId;
beentry->st_userid = userid;
beentry->st_session_id = gp_session_id; /* GPDB only */
beentry->st_clientaddr = clientaddr;
beentry->st_waiting = false;
beentry->st_appname[0] = '\0';
beentry->st_activity[0] = '\0';
/* Also make sure the last byte in each string area is always 0 */
beentry->st_appname[NAMEDATALEN - 1] = '\0';
beentry->st_activity[pgstat_track_activity_query_size - 1] = '\0';
beentry->st_waiting_resource = false;
beentry->st_changecount++;
Assert((beentry->st_changecount & 1) == 0);
/*
* GPDB: Initialize per-portal statistics hash for resource queues.
*/
pgstat_init_localportalhash();
/*
* GPDB: Set up a process-exit hook to clean up.
*/
on_shmem_exit(pgstat_beshutdown_hook, 0);
/* Update app name to current GUC setting */
if (application_name)
pgstat_report_appname(application_name);
}
/*
* Shut down a single backend's statistics reporting at process exit.
*
* Flush any remaining statistics counts out to the collector.
* Without this, operations triggered during backend exit (such as
* temp table deletions) won't be counted.
*
* Lastly, clear out our entry in the PgBackendStatus array.
*/
static void
pgstat_beshutdown_hook(int code, Datum arg)
{
volatile PgBackendStatus *beentry = MyBEEntry;
/*
* If we got as far as discovering our own database ID, we can report what
* we did to the collector. Otherwise, we'd be sending 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_stat(true);
/*
* Clear my status entry, following the protocol of bumping st_changecount
* before and after. We use a volatile pointer here to ensure the
* compiler doesn't try to get cute.
*/
beentry->st_changecount++;
beentry->st_procpid = 0; /* mark invalid */
beentry->st_session_id = 0;
beentry->st_changecount++;
Assert((beentry->st_changecount & 1) == 0);
}
/* ----------
* pgstat_report_activity() -
*
* Called from tcop/postgres.c to report what the backend is actually doing
* (usually "<IDLE>" or the start of the query to be executed).
* ----------
*/
void
pgstat_report_activity(const char *cmd_str)
{
volatile PgBackendStatus *beentry = MyBEEntry;
TimestampTz start_timestamp;
int len;
// TRACE_POSTGRESQL_STATEMENT_STATUS(cmd_str);
if (!pgstat_track_activities || !beentry)
return;
/*
* To minimize the time spent modifying the entry, fetch all the needed
* data first.
*/
start_timestamp = GetCurrentStatementStartTimestamp();
len = strlen(cmd_str);
len = pg_mbcliplen(cmd_str, len, pgstat_track_activity_query_size - 1);
/*
* Update my status entry, following the protocol of bumping
* st_changecount before and after. We use a volatile pointer here to
* ensure the compiler doesn't try to get cute.
*/
beentry->st_changecount++;
beentry->st_activity_start_timestamp = start_timestamp;
memcpy((char *) beentry->st_activity, cmd_str, len);
beentry->st_activity[len] = '\0';
beentry->st_changecount++;
Assert((beentry->st_changecount & 1) == 0);
}
/* ----------
* pgstat_report_appname() -
*
* Called to update our application name.
* ----------
*/
void
pgstat_report_appname(const char *appname)
{
volatile PgBackendStatus *beentry = MyBEEntry;
int len;
if (!beentry)
return;
/* This should be unnecessary if GUC did its job, but be safe */
len = pg_mbcliplen(appname, strlen(appname), NAMEDATALEN - 1);
/*
* Update my status entry, following the protocol of bumping
* st_changecount before and after. We use a volatile pointer here to
* ensure the compiler doesn't try to get cute.
*/
beentry->st_changecount++;
memcpy((char *) beentry->st_appname, appname, len);
beentry->st_appname[len] = '\0';
beentry->st_changecount++;
Assert((beentry->st_changecount & 1) == 0);
}
/*
* Report current transaction start timestamp as the specified value.
* Zero means there is no active transaction.
*/
void
pgstat_report_xact_timestamp(TimestampTz tstamp)
{
volatile PgBackendStatus *beentry = MyBEEntry;
if (!pgstat_track_activities || !beentry)
return;
/*
* Update my status entry, following the protocol of bumping
* st_changecount before and after. We use a volatile pointer here to
* ensure the compiler doesn't try to get cute.
*/
beentry->st_changecount++;
beentry->st_xact_start_timestamp = tstamp;
beentry->st_changecount++;
Assert((beentry->st_changecount & 1) == 0);
}
/* ----------
* pgstat_report_waiting() -
*
* Called from lock manager to report beginning or end of a lock wait.
*
* NB: this *must* be able to survive being called before MyBEEntry has been
* initialized.
* ----------
*/
void
pgstat_report_waiting(bool waiting)
{
volatile PgBackendStatus *beentry = MyBEEntry;
if (!pgstat_track_activities || !beentry)
return;
/*
* Since this is a single-byte field in a struct that only this process
* may modify, there seems no need to bother with the st_changecount
* protocol. The update must appear atomic in any case.
*/
beentry->st_waiting = waiting;
}
/* ----------
* pgstat_report_waiting_resource() -
*
* report beginning or end of a resource wait.
*
* NB: this *must* be able to survive being called before MyBEEntry has been
* initialized.
* ----------
*/
void
pgstat_report_waiting_resource(bool waiting)
{
volatile PgBackendStatus *beentry = MyBEEntry;
if (!pgstat_track_activities || !beentry)
return;
/*
* Since this is a single-byte field in a struct that only this process
* may modify, there seems no need to bother with the st_changecount
* protocol. The update must appear atomic in any case.
*/
beentry->st_waiting_resource = waiting;
}
/* ----------
* pgstat_read_current_status() -
*
* Copy the current contents of the PgBackendStatus array to local memory,
* if not already done in this transaction.
* ----------
*/
static void
pgstat_read_current_status(void)
{
volatile PgBackendStatus *beentry;
PgBackendStatus *localtable;
PgBackendStatus *localentry;
char *localappname;
char *localactivity;
int i;
Assert(!pgStatRunningInCollector);
if (localBackendStatusTable)
return; /* already done */
pgstat_setup_memcxt();
localtable = (PgBackendStatus *)
MemoryContextAlloc(pgStatLocalContext,
sizeof(PgBackendStatus) * MaxBackends);
localappname = (char *)
MemoryContextAlloc(pgStatLocalContext,
NAMEDATALEN * MaxBackends);
localactivity = (char *)
MemoryContextAlloc(pgStatLocalContext,
pgstat_track_activity_query_size * MaxBackends);
localNumBackends = 0;
beentry = BackendStatusArray;
localentry = localtable;
for (i = 1; i <= MaxBackends; i++)
{
/*
* Follow the protocol of retrying if st_changecount changes while we
* copy the entry, or if it's odd. (The check for odd is needed to
* cover the case where we are able to completely copy the entry while
* the source backend is between increment steps.) We use a volatile
* pointer here to ensure the compiler doesn't try to get cute.
*/
for (;;)
{
int save_changecount = beentry->st_changecount;
localentry->st_procpid = beentry->st_procpid;
if (localentry->st_procpid > 0)
{
memcpy(localentry, (char *) beentry, sizeof(PgBackendStatus));
/*
* strcpy is safe even if the string is modified concurrently,
* because there's always a \0 at the end of the buffer.
*/
strcpy(localappname, (char *) beentry->st_appname);
localentry->st_appname = localappname;
strcpy(localactivity, (char *) beentry->st_activity);
localentry->st_activity = localactivity;
}
if (save_changecount == beentry->st_changecount &&
(save_changecount & 1) == 0)
break;
/* Make sure we can break out of loop if stuck... */
CHECK_FOR_INTERRUPTS();
}
beentry++;
/* Only valid entries get included into the local array */
if (localentry->st_procpid > 0)
{
localentry++;
localappname += NAMEDATALEN;
localactivity += pgstat_track_activity_query_size;
localNumBackends++;
}
}
/* Set the pointer only after completion of a valid table */
localBackendStatusTable = localtable;
}
/* ----------
* pgstat_get_backend_current_activity() -
*
* Return a string representing the current activity of the backend with
* the specified PID. This looks directly at the BackendStatusArray,
* and so will provide current information regardless of the age of our
* transaction's snapshot of the status array.
*
* It is the caller's responsibility to invoke this only for backends whose
* state is expected to remain stable while the result is in use. The
* only current use is in deadlock reporting, where we can expect that
* the target backend is blocked on a lock. (There are corner cases
* where the target's wait could get aborted while we are looking at it,
* but the very worst consequence is to return a pointer to a string
* that's been changed, so we won't worry too much.)
*
* Note: return strings for special cases match pg_stat_get_backend_activity.
* ----------
*/
const char *
pgstat_get_backend_current_activity(int pid, bool checkUser)
{
PgBackendStatus *beentry;
int i;
beentry = BackendStatusArray;
for (i = 1; i <= MaxBackends; i++)
{
/*
* Although we expect the target backend's entry to be stable, that
* doesn't imply that anyone else's is. To avoid identifying the
* wrong backend, while we check for a match to the desired PID we
* must follow the protocol of retrying if st_changecount changes
* while we examine the entry, or if it's odd. (This might be
* unnecessary, since fetching or storing an int is almost certainly
* atomic, but let's play it safe.) We use a volatile pointer here to
* ensure the compiler doesn't try to get cute.
*/
volatile PgBackendStatus *vbeentry = beentry;
bool found;
for (;;)
{
int save_changecount = vbeentry->st_changecount;
found = (vbeentry->st_procpid == pid);
if (save_changecount == vbeentry->st_changecount &&
(save_changecount & 1) == 0)
break;
/* Make sure we can break out of loop if stuck... */
CHECK_FOR_INTERRUPTS();
}
if (found)
{
/* Now it is safe to use the non-volatile pointer */
if (checkUser && !superuser() && beentry->st_userid != GetUserId())
return "<insufficient privilege>";
else if (*(beentry->st_activity) == '\0')
return "<command string not enabled>";
else
return beentry->st_activity;
}
beentry++;
}
/* If we get here, caller is in error ... */
return "<backend information not available>";
}
/* ------------------------------------------------------------
* Local support functions follow
* ------------------------------------------------------------
*/
/* ----------
* pgstat_setheader() -
*
* Set common header fields in a statistics message
* ----------
*/
static void
pgstat_setheader(PgStat_MsgHdr *hdr, StatMsgType mtype)
{
hdr->m_type = mtype;
}
/* ----------
* pgstat_send() -
*
* Send out one statistics message to the collector
* ----------
*/
static void
pgstat_send(void *msg, int len)
{
int rc;
if (pgStatSock == PGINVALID_SOCKET)
return;
((PgStat_MsgHdr *) msg)->m_size = len;
/* We'll retry after EINTR, but ignore all other failures */
do
{
rc = send(pgStatSock, msg, len, 0);
} while (rc < 0 && errno == EINTR);
#ifdef USE_ASSERT_CHECKING
/* In debug builds, log send failures ... */
if (rc < 0)
elog(LOG, "could not send to statistics collector: %m");
#endif
}
/* ----------
* pgstat_send_bgwriter() -
*
* Send bgwriter statistics to the collector
* ----------
*/
void
pgstat_send_bgwriter(void)
{
/* We assume this initializes to zeroes */
static const PgStat_MsgBgWriter all_zeroes;
/*
* 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.
*/
if (memcmp(&BgWriterStats, &all_zeroes, sizeof(PgStat_MsgBgWriter)) == 0)
return;
/*
* Prepare and send the message
*/
pgstat_setheader(&BgWriterStats.m_hdr, PGSTAT_MTYPE_BGWRITER);
pgstat_send(&BgWriterStats, sizeof(BgWriterStats));
/*
* Clear out the statistics buffer, so it can be re-used.
*/
MemSet(&BgWriterStats, 0, sizeof(BgWriterStats));
}
/* ----------
* PgstatCollectorMain() -
*
* Start up the statistics collector process. This is the body of the
* postmaster child process.
*
* The argc/argv parameters are valid only in EXEC_BACKEND case.
* ----------
*/
NON_EXEC_STATIC void
PgstatCollectorMain(int argc, char *argv[])
{
int len;
PgStat_Msg msg;
#ifndef WIN32
#ifdef HAVE_POLL
struct pollfd input_fd;
#else
struct timeval sel_timeout;
fd_set rfds;
#endif
#endif
IsUnderPostmaster = true; /* we are a postmaster subprocess now */
MyProcPid = getpid(); /* reset MyProcPid */
MyStartTime = time(NULL); /* record Start Time for logging */
/*
* If possible, make this process a group leader, so that the postmaster
* can signal any child processes too. (pgstat probably never has any
* child processes, but for consistency we make all postmaster child
* processes do this.)
*/
#ifdef HAVE_SETSID
if (setsid() < 0)
elog(FATAL, "setsid() failed: %m");
#endif
/*
* Ignore all signals usually bound to some action in the postmaster,
* except SIGQUIT.
*/
pqsignal(SIGHUP, pgstat_sighup_handler);
pqsignal(SIGINT, SIG_IGN);
pqsignal(SIGTERM, SIG_IGN);
pqsignal(SIGQUIT, pgstat_exit);
pqsignal(SIGALRM, SIG_IGN);
pqsignal(SIGPIPE, SIG_IGN);
pqsignal(SIGUSR1, SIG_IGN);
pqsignal(SIGUSR2, SIG_IGN);
pqsignal(SIGCHLD, SIG_DFL);
pqsignal(SIGTTIN, SIG_DFL);
pqsignal(SIGTTOU, SIG_DFL);
pqsignal(SIGCONT, SIG_DFL);
pqsignal(SIGWINCH, SIG_DFL);
PG_SETMASK(&UnBlockSig);
/*
* Identify myself via ps
*/
init_ps_display("stats collector process", "", "", "");
/*
* Arrange to write the initial status file right away
*/
last_statrequest = GetCurrentTimestamp();
last_statwrite = last_statrequest - 1;
/*
* Read in an existing statistics stats file or initialize the stats to
* zero.
*/
pgStatRunningInCollector = true;
pgStatDBHash = pgstat_read_statsfile(InvalidOid, true);
/*
* Setup the descriptor set for select(2). Since only one bit in the set
* ever changes, we need not repeat FD_ZERO each time.
*/
#if !defined(HAVE_POLL) && !defined(WIN32)
FD_ZERO(&rfds);
#endif
/*
* Loop to process messages until we get SIGQUIT or detect ungraceful
* death of our parent postmaster.
*
* For performance reasons, we don't want to do a PostmasterIsAlive() test
* after every message; instead, do it only when select()/poll() is
* interrupted by timeout. In essence, we'll stay alive as long as
* backends keep sending us stuff often, even if the postmaster is gone.
*/
for (;;)
{
int got_data;
/*
* Quit if we get SIGQUIT from the postmaster.
*/
if (need_exit)
break;
/*
* Reload configuration if we got SIGHUP from the postmaster.
*/
if (got_SIGHUP)
{
ProcessConfigFile(PGC_SIGHUP);
got_SIGHUP = false;
}
/*
* Write the stats file if a new request has arrived that is not
* satisfied by existing file.
*/
if (last_statwrite < last_statrequest)
pgstat_write_statsfile(false);
/*
* Wait for a message to arrive; but not for more than
* PGSTAT_SELECT_TIMEOUT seconds. (This determines how quickly we will
* shut down after an ungraceful postmaster termination; so it needn't
* be very fast. However, on some systems SIGQUIT won't interrupt the
* poll/select call, so this also limits speed of response to SIGQUIT,
* which is more important.)
*
* We use poll(2) if available, otherwise select(2). Win32 has its own
* implementation.
*/
#ifndef WIN32
#ifdef HAVE_POLL
input_fd.fd = pgStatSock;
input_fd.events = POLLIN | POLLERR;
input_fd.revents = 0;
if (poll(&input_fd, 1, PGSTAT_SELECT_TIMEOUT * 1000) < 0)
{
if (errno == EINTR)
continue;
ereport(ERROR,
(errcode_for_socket_access(),
errmsg("poll() failed in statistics collector: %m")));
}
got_data = (input_fd.revents != 0);
#else /* !HAVE_POLL */
FD_SET(pgStatSock, &rfds);
/*
* timeout struct is modified by select() on some operating systems,
* so re-fill it each time.
*/
sel_timeout.tv_sec = PGSTAT_SELECT_TIMEOUT;
sel_timeout.tv_usec = 0;
if (select(pgStatSock + 1, &rfds, NULL, NULL, &sel_timeout) < 0)
{
if (errno == EINTR)
continue;
ereport(ERROR,
(errcode_for_socket_access(),
errmsg("select() failed in statistics collector: %m")));
}
got_data = FD_ISSET(pgStatSock, &rfds);
#endif /* HAVE_POLL */
#else /* WIN32 */
got_data = pgwin32_waitforsinglesocket(pgStatSock, FD_READ,
PGSTAT_SELECT_TIMEOUT*1000);
#endif
/*
* If there is a message on the socket, read it and check for
* validity.
*/
if (got_data)
{
len = recv(pgStatSock, (char *) &msg,
sizeof(PgStat_Msg), 0);
if (len < 0)
{
if (errno == EINTR)
continue;
ereport(ERROR,
(errcode_for_socket_access(),
errmsg("could not read statistics message: %m")));
}
/*
* We ignore messages that are smaller than our common header
*/
if (len < sizeof(PgStat_MsgHdr))
continue;
/*
* The received length must match the length in the header
*/
if (msg.msg_hdr.m_size != len)
continue;
/*
* O.K. - we accept this message. Process it.
*/
switch (msg.msg_hdr.m_type)
{
case PGSTAT_MTYPE_DUMMY:
break;
case PGSTAT_MTYPE_INQUIRY:
pgstat_recv_inquiry((PgStat_MsgInquiry *) &msg, len);
break;
case PGSTAT_MTYPE_TABSTAT:
pgstat_recv_tabstat((PgStat_MsgTabstat *) &msg, len);
break;
case PGSTAT_MTYPE_TABPURGE:
pgstat_recv_tabpurge((PgStat_MsgTabpurge *) &msg, len);
break;
case PGSTAT_MTYPE_DROPDB:
pgstat_recv_dropdb((PgStat_MsgDropdb *) &msg, len);
break;
case PGSTAT_MTYPE_RESETCOUNTER:
pgstat_recv_resetcounter((PgStat_MsgResetcounter *) &msg,
len);
break;
case PGSTAT_MTYPE_AUTOVAC_START:
pgstat_recv_autovac((PgStat_MsgAutovacStart *) &msg, len);
break;
case PGSTAT_MTYPE_VACUUM:
pgstat_recv_vacuum((PgStat_MsgVacuum *) &msg, len);
break;
case PGSTAT_MTYPE_ANALYZE:
pgstat_recv_analyze((PgStat_MsgAnalyze *) &msg, len);
break;
case PGSTAT_MTYPE_BGWRITER:
pgstat_recv_bgwriter((PgStat_MsgBgWriter *) &msg, len);
break;
case PGSTAT_MTYPE_QUEUESTAT: /* GPDB */
pgstat_recv_queuestat((PgStat_MsgQueuestat *) &msg, len);
break;
case PGSTAT_MTYPE_FUNCSTAT:
pgstat_recv_funcstat((PgStat_MsgFuncstat *) &msg, len);
break;
case PGSTAT_MTYPE_FUNCPURGE:
pgstat_recv_funcpurge((PgStat_MsgFuncpurge *) &msg, len);
break;
default:
break;
}
}
else
{
/*
* We can only get here if the select/poll timeout elapsed. Check
* for postmaster death.
*/
if (!PostmasterIsAlive(true))
break;
}
} /* end of message-processing loop */
/*
* Save the final stats to reuse at next startup.
*/
pgstat_write_statsfile(true);
exit(0);
}
/* SIGQUIT signal handler for collector process */
static void
pgstat_exit(SIGNAL_ARGS)
{
need_exit = true;
}
/* SIGHUP handler for collector process */
static void
pgstat_sighup_handler(SIGNAL_ARGS)
{
got_SIGHUP = true;
}
/*
* Lookup the hash table entry for the specified database. If no hash
* table entry exists, initialize it, if the create parameter is true.
* Else, return NULL.
*/
static PgStat_StatDBEntry *
pgstat_get_db_entry(Oid databaseid, bool create)
{
PgStat_StatDBEntry *result;
bool found;
HASHACTION action = (create ? HASH_ENTER : HASH_FIND);
/* Lookup or create the hash table entry for this database */
result = (PgStat_StatDBEntry *) hash_search(pgStatDBHash,
&databaseid,
action, &found);
if (!create && !found)
return NULL;
/* If not found, initialize the new one. */
if (!found)
{
HASHCTL hash_ctl;
result->tables = NULL;
result->functions = NULL;
result->n_xact_commit = 0;
result->n_xact_rollback = 0;
result->n_blocks_fetched = 0;
result->n_blocks_hit = 0;
result->n_tuples_returned = 0;
result->n_tuples_fetched = 0;
result->n_tuples_inserted = 0;
result->n_tuples_updated = 0;
result->n_tuples_deleted = 0;
result->last_autovac_time = 0;
memset(&hash_ctl, 0, sizeof(hash_ctl));
hash_ctl.keysize = sizeof(Oid);
hash_ctl.entrysize = sizeof(PgStat_StatTabEntry);
hash_ctl.hash = oid_hash;
result->tables = hash_create("Per-database table",
PGSTAT_TAB_HASH_SIZE,
&hash_ctl,
HASH_ELEM | HASH_FUNCTION);
hash_ctl.keysize = sizeof(Oid);
hash_ctl.entrysize = sizeof(PgStat_StatFuncEntry);
hash_ctl.hash = oid_hash;
result->functions = hash_create("Per-database function",
PGSTAT_FUNCTION_HASH_SIZE,
&hash_ctl,
HASH_ELEM | HASH_FUNCTION);
}
return result;
}
/* ----------
* pgstat_write_statsfile() -
*
* Tell the news.
* If writing to the permanent file (happens when the collector is
* shutting down only), remove the temporary file so that backends
* starting up under a new postmaster can't read the old data before
* the new collector is ready.
* ----------
*/
static void
pgstat_write_statsfile(bool permanent)
{
HASH_SEQ_STATUS hstat;
HASH_SEQ_STATUS tstat;
HASH_SEQ_STATUS fstat;
PgStat_StatDBEntry *dbentry;
PgStat_StatTabEntry *tabentry;
PgStat_StatFuncEntry *funcentry;
FILE *fpout;
int32 format_id;
const char *tmpfile = permanent ? PGSTAT_STAT_PERMANENT_TMPFILE : pgstat_stat_tmpname;
const char *statfile = permanent ? PGSTAT_STAT_PERMANENT_FILENAME : pgstat_stat_filename;
/*
* 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;
}
/*
* Set the timestamp of the stats file.
*/
globalStats.stats_timestamp = GetCurrentTimestamp();
/*
* Write the file header --- currently just a format ID.
*/
format_id = PGSTAT_FILE_FORMAT_ID;
fwrite(&format_id, sizeof(format_id), 1, fpout);
/*
* Write global stats struct
*/
fwrite(&globalStats, sizeof(globalStats), 1, fpout);
/*
* Walk through the database table.
*/
hash_seq_init(&hstat, pgStatDBHash);
while ((dbentry = (PgStat_StatDBEntry *) hash_seq_search(&hstat)) != NULL)
{
/*
* Write out the DB entry including the number of live backends. We
* don't write the tables or functions pointers, since they're of no
* use to any other process.
*/
fputc('D', fpout);
fwrite(dbentry, offsetof(PgStat_StatDBEntry, tables), 1, fpout);
/*
* Walk through the database's access stats per table.
*/
hash_seq_init(&tstat, dbentry->tables);
while ((tabentry = (PgStat_StatTabEntry *) hash_seq_search(&tstat)) != NULL)
{
fputc('T', fpout);
fwrite(tabentry, sizeof(PgStat_StatTabEntry), 1, fpout);
}
/*
* Walk through the database's function stats table.
*/
hash_seq_init(&fstat, dbentry->functions);
while ((funcentry = (PgStat_StatFuncEntry *) hash_seq_search(&fstat)) != NULL)
{
fputc('F', fpout);
fwrite(funcentry, sizeof(PgStat_StatFuncEntry), 1, fpout);
}
/*
* Mark the end of this DB
*/
fputc('d', fpout);
}
/*
* 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 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);
}
else
{
/*
* Successful write, so update last_statwrite.
*/
last_statwrite = globalStats.stats_timestamp;
/*
* It's not entirely clear whether there could be clock skew between
* backends and the collector; but just in case someone manages to
* send us a stats request time that's far in the future, reset it.
* This ensures that no inquiry message can cause more than one stats
* file write to occur.
*/
last_statrequest = last_statwrite;
}
if (permanent)
unlink(pgstat_stat_filename);
}
/* ----------
* pgstat_read_statsfile() -
*
* Reads in an existing statistics collector file and initializes the
* databases' hash table (whose entries point to the tables' hash tables).
* ----------
*/
static HTAB *
pgstat_read_statsfile(Oid onlydb, bool permanent)
{
PgStat_StatDBEntry *dbentry;
PgStat_StatDBEntry dbbuf;
PgStat_StatTabEntry *tabentry;
PgStat_StatTabEntry tabbuf;
PgStat_StatFuncEntry funcbuf;
PgStat_StatFuncEntry *funcentry;
PgStat_StatQueueEntry queuebuf; /* GPDB */
PgStat_StatQueueEntry *queueentry; /* GPDB */
HASHCTL hash_ctl;
HTAB *dbhash;
HTAB *tabhash = NULL;
HTAB *funchash = NULL;
HTAB *queuehash = NULL; /* GPDB */
FILE *fpin;
int32 format_id;
bool found;
const char *statfile = permanent ? PGSTAT_STAT_PERMANENT_FILENAME : pgstat_stat_filename;
/*
* The tables will live in pgStatLocalContext.
*/
pgstat_setup_memcxt();
/*
* Create the DB hashtable
*/
memset(&hash_ctl, 0, sizeof(hash_ctl));
hash_ctl.keysize = sizeof(Oid);
hash_ctl.entrysize = sizeof(PgStat_StatDBEntry);
hash_ctl.hash = oid_hash;
hash_ctl.hcxt = pgStatLocalContext;
dbhash = hash_create("Databases hash", PGSTAT_DB_HASH_SIZE, &hash_ctl,
HASH_ELEM | HASH_FUNCTION | HASH_CONTEXT);
/*
* Clear out global statistics so they start from zero in case we can't
* load an existing statsfile.
*/
memset(&globalStats, 0, sizeof(globalStats));
/**
** Create the Queue hashtable
**/
memset(&hash_ctl, 0, sizeof(hash_ctl));
hash_ctl.keysize = sizeof(Oid);
hash_ctl.entrysize = sizeof(PgStat_StatQueueEntry);
hash_ctl.hash = oid_hash;
hash_ctl.hcxt = pgStatLocalContext;
queuehash = hash_create("Queues hash", PGSTAT_QUEUE_HASH_SIZE, &hash_ctl,
HASH_ELEM | HASH_FUNCTION | HASH_CONTEXT);
pgStatQueueHash = queuehash;
/*
* Clear out global statistics so they start from zero in case we can't
* load an existing statsfile.
*/
memset(&globalStats, 0, sizeof(globalStats));
/*
* Try to open the status file. If it doesn't exist, the backends simply
* return zero for anything and the collector simply starts from scratch
* with empty counters.
*/
if ((fpin = AllocateFile(statfile, PG_BINARY_R)) == NULL)
return dbhash;
/*
* Try to open the status file. If it doesn't exist, the backends simply
* return zero for anything and the collector simply starts from scratch
* with empty counters.
*/
if ((fpin = AllocateFile(statfile, PG_BINARY_R)) == NULL)
return dbhash;
/*
* Verify it's of the expected format.
*/
if (fread(&format_id, 1, sizeof(format_id), fpin) != sizeof(format_id)
|| format_id != PGSTAT_FILE_FORMAT_ID)
{
ereport(pgStatRunningInCollector ? LOG : WARNING,
(errmsg("corrupted pgstat.stat file")));
goto done;
}
/*
* Read global stats struct
*/
if (fread(&globalStats, 1, sizeof(globalStats), fpin) != sizeof(globalStats))
{
ereport(pgStatRunningInCollector ? LOG : WARNING,
(errmsg("corrupted pgstat.stat file")));
goto done;
}
/*
* We found an existing collector stats file. Read it and put all the
* hashtable entries into place.
*/
for (;;)
{
switch (fgetc(fpin))
{
/*
* 'D' A PgStat_StatDBEntry struct describing a database
* follows. Subsequently, zero to many 'T' and 'F' entries
* will follow until a 'd' is encountered.
*/
case 'D':
if (fread(&dbbuf, 1, offsetof(PgStat_StatDBEntry, tables),
fpin) != offsetof(PgStat_StatDBEntry, tables))
{
ereport(pgStatRunningInCollector ? LOG : WARNING,
(errmsg("corrupted pgstat.stat file")));
goto done;
}
/*
* Add to the DB hash
*/
dbentry = (PgStat_StatDBEntry *) hash_search(dbhash,
(void *) &dbbuf.databaseid,
HASH_ENTER,
&found);
if (found)
{
ereport(pgStatRunningInCollector ? LOG : WARNING,
(errmsg("corrupted pgstat.stat file")));
goto done;
}
memcpy(dbentry, &dbbuf, sizeof(PgStat_StatDBEntry));
dbentry->tables = NULL;
dbentry->functions = NULL;
/*
* Don't collect tables if not the requested DB (or the
* shared-table info)
*/
if (onlydb != InvalidOid)
{
if (dbbuf.databaseid != onlydb &&
dbbuf.databaseid != InvalidOid)
break;
}
memset(&hash_ctl, 0, sizeof(hash_ctl));
hash_ctl.keysize = sizeof(Oid);
hash_ctl.entrysize = sizeof(PgStat_StatTabEntry);
hash_ctl.hash = oid_hash;
hash_ctl.hcxt = pgStatLocalContext;
dbentry->tables = hash_create("Per-database table",
PGSTAT_TAB_HASH_SIZE,
&hash_ctl,
HASH_ELEM | HASH_FUNCTION | HASH_CONTEXT);
memset(&hash_ctl, 0, sizeof(hash_ctl));
hash_ctl.keysize = sizeof(Oid);
hash_ctl.entrysize = sizeof(PgStat_StatFuncEntry);
hash_ctl.hash = oid_hash;
hash_ctl.hcxt = pgStatLocalContext;
dbentry->functions = hash_create("Per-database function",
PGSTAT_FUNCTION_HASH_SIZE,
&hash_ctl,
HASH_ELEM | HASH_FUNCTION | HASH_CONTEXT);
/*
* Arrange that following records add entries to this
* database's hash tables.
*/
tabhash = dbentry->tables;
funchash = dbentry->functions;
break;
/*
* 'd' End of this database.
*/
case 'd':
tabhash = NULL;
funchash = NULL;
break;
/*
* 'T' A PgStat_StatTabEntry follows.
*/
case 'T':
if (fread(&tabbuf, 1, sizeof(PgStat_StatTabEntry),
fpin) != sizeof(PgStat_StatTabEntry))
{
ereport(pgStatRunningInCollector ? LOG : WARNING,
(errmsg("corrupted pgstat.stat file")));
goto done;
}
/*
* Skip if table belongs to a not requested database.
*/
if (tabhash == NULL)
break;
tabentry = (PgStat_StatTabEntry *) hash_search(tabhash,
(void *) &tabbuf.tableid,
HASH_ENTER, &found);
if (found)
{
ereport(pgStatRunningInCollector ? LOG : WARNING,
(errmsg("corrupted pgstat.stat file")));
goto done;
}
memcpy(tabentry, &tabbuf, sizeof(tabbuf));
break;
/*
* 'F' A PgStat_StatFuncEntry follows.
*/
case 'F':
if (fread(&funcbuf, 1, sizeof(PgStat_StatFuncEntry),
fpin) != sizeof(PgStat_StatFuncEntry))
{
ereport(pgStatRunningInCollector ? LOG : WARNING,
(errmsg("corrupted pgstat.stat file")));
goto done;
}
/*
* Skip if function belongs to a not requested database.
*/
if (funchash == NULL)
break;
funcentry = (PgStat_StatFuncEntry *) hash_search(funchash,
(void *) &funcbuf.functionid,
HASH_ENTER, &found);
if (found)
{
ereport(pgStatRunningInCollector ? LOG : WARNING,
(errmsg("corrupted pgstat.stat file")));
goto done;
}
memcpy(funcentry, &funcbuf, sizeof(funcbuf));
break;
/*
* 'Q' A PgStat_StatQueueEntry follows. (GPDB)
*/
case 'Q':
if (fread(&queuebuf, 1, sizeof(PgStat_StatQueueEntry),
fpin) != sizeof(PgStat_StatQueueEntry))
{
ereport(pgStatRunningInCollector ? LOG : WARNING,
(errmsg("corrupted pgstat.stat file")));
goto done;
}
if (queuehash == NULL)
break;
/*
* Add it to the queue hash.
*/
queueentry = (PgStat_StatQueueEntry *) hash_search(queuehash,
(void *) &queuebuf.queueid,
HASH_ENTER, &found);
if (found)
{
ereport(pgStatRunningInCollector ? LOG : WARNING,
(errmsg("corrupted pgstat.stat file")));
goto done;
}
memcpy(queueentry, &queuebuf, sizeof(PgStat_StatQueueEntry));
break;
/*
* 'E' The EOF marker of a complete stats file.
*/
case 'E':
goto done;
default:
ereport(pgStatRunningInCollector ? LOG : WARNING,
(errmsg("corrupted pgstat.stat file")));
goto done;
}
}
done:
FreeFile(fpin);
if (permanent)
unlink(PGSTAT_STAT_PERMANENT_FILENAME);
return dbhash;
}
/* ----------
* pgstat_read_statsfile_timestamp() -
*
* Attempt to fetch the timestamp of an existing stats file.
* Returns TRUE if successful (timestamp is stored at *ts).
* ----------
*/
static bool
pgstat_read_statsfile_timestamp(bool permanent, TimestampTz *ts)
{
PgStat_GlobalStats myGlobalStats;
FILE *fpin;
int32 format_id;
const char *statfile = permanent ? PGSTAT_STAT_PERMANENT_FILENAME : pgstat_stat_filename;
/*
* Try to open the status file.
*/
if ((fpin = AllocateFile(statfile, PG_BINARY_R)) == NULL)
return false;
/*
* Verify it's of the expected format.
*/
if (fread(&format_id, 1, sizeof(format_id), fpin) != sizeof(format_id)
|| format_id != PGSTAT_FILE_FORMAT_ID)
{
FreeFile(fpin);
return false;
}
/*
* Read global stats struct
*/
if (fread(&myGlobalStats, 1, sizeof(myGlobalStats), fpin) != sizeof(myGlobalStats))
{
FreeFile(fpin);
return false;
}
*ts = myGlobalStats.stats_timestamp;
FreeFile(fpin);
return true;
}
/*
* If not already done, read the statistics collector stats file into
* some hash tables. The results will be kept until pgstat_clear_snapshot()
* is called (typically, at end of transaction).
*/
static void
backend_read_statsfile(void)
{
TimestampTz min_ts;
int count;
/* already read it? */
if (pgStatDBHash)
return;
Assert(!pgStatRunningInCollector);
/*
* We set the minimum acceptable timestamp to PGSTAT_STAT_INTERVAL msec
* before now. This indirectly ensures that the collector needn't write
* the file more often than PGSTAT_STAT_INTERVAL. In an autovacuum
* worker, however, we want a lower delay to avoid using stale data, so we
* use PGSTAT_RETRY_DELAY (since the number of worker is low, this
* shouldn't be a problem).
*
* Note that we don't recompute min_ts after sleeping; so we might end up
* accepting a file a bit older than PGSTAT_STAT_INTERVAL. In practice
* that shouldn't happen, though, as long as the sleep time is less than
* PGSTAT_STAT_INTERVAL; and we don't want to lie to the collector about
* what our cutoff time really is.
*/
//if (IsAutoVacuumWorkerProcess())
if (IsAutoVacuumProcess())
min_ts = TimestampTzPlusMilliseconds(GetCurrentTimestamp(),
-PGSTAT_RETRY_DELAY);
else
min_ts = TimestampTzPlusMilliseconds(GetCurrentTimestamp(),
-PGSTAT_STAT_INTERVAL);
/*
* Loop until fresh enough stats file is available or we ran out of time.
* The stats inquiry message is sent repeatedly in case collector drops
* it.
*/
for (count = 0; count < PGSTAT_POLL_LOOP_COUNT; count++)
{
TimestampTz file_ts = 0;
CHECK_FOR_INTERRUPTS();
if (pgstat_read_statsfile_timestamp(false, &file_ts) &&
file_ts >= min_ts)
break;
/* Not there or too old, so kick the collector and wait a bit */
pgstat_send_inquiry(min_ts);
pg_usleep(PGSTAT_RETRY_DELAY * 1000L);
}
if (count >= PGSTAT_POLL_LOOP_COUNT)
elog(WARNING, "pgstat wait timeout");
/* Autovacuum launcher wants stats about all databases */
//if (IsAutoVacuumLauncherProcess())
pgStatDBHash = pgstat_read_statsfile(InvalidOid, false);
//else
// pgStatDBHash = pgstat_read_statsfile(MyDatabaseId, false);
}
/* ----------
* pgstat_setup_memcxt() -
*
* Create pgStatLocalContext, if not already done.
* ----------
*/
static void
pgstat_setup_memcxt(void)
{
if (!pgStatLocalContext)
pgStatLocalContext = AllocSetContextCreate(TopMemoryContext,
"Statistics snapshot",
ALLOCSET_SMALL_MINSIZE,
ALLOCSET_SMALL_INITSIZE,
ALLOCSET_SMALL_MAXSIZE);
}
/* ----------
* pgstat_clear_snapshot() -
*
* Discard any data collected in the current transaction. Any subsequent
* request will cause new snapshots to be read.
*
* This is also invoked during transaction commit or abort to discard
* the no-longer-wanted snapshot.
* ----------
*/
void
pgstat_clear_snapshot(void)
{
/* Release memory, if any was allocated */
if (pgStatLocalContext)
MemoryContextDelete(pgStatLocalContext);
/* Reset variables */
pgStatLocalContext = NULL;
pgStatDBHash = NULL;
localBackendStatusTable = NULL;
localNumBackends = 0;
}
/* ----------
* pgstat_recv_inquiry() -
*
* Process stat inquiry requests.
* ----------
*/
static void
pgstat_recv_inquiry(PgStat_MsgInquiry *msg, int len)
{
if (msg->inquiry_time > last_statrequest)
last_statrequest = msg->inquiry_time;
}
/* ----------
* pgstat_recv_tabstat() -
*
* Count what the backend has done.
* ----------
*/
static void
pgstat_recv_tabstat(PgStat_MsgTabstat *msg, int len)
{
PgStat_TableEntry *tabmsg = &(msg->m_entry[0]);
PgStat_StatDBEntry *dbentry;
PgStat_StatTabEntry *tabentry;
int i;
bool found;
dbentry = pgstat_get_db_entry(msg->m_databaseid, true);
/*
* Update database-wide stats.
*/
dbentry->n_xact_commit += (PgStat_Counter) (msg->m_xact_commit);
dbentry->n_xact_rollback += (PgStat_Counter) (msg->m_xact_rollback);
/*
* Process all table entries in the message.
*/
for (i = 0; i < msg->m_nentries; i++)
{
tabentry = (PgStat_StatTabEntry *) hash_search(dbentry->tables,
(void *) &(tabmsg[i].t_id),
HASH_ENTER, &found);
if (!found)
{
/*
* If it's a new table entry, initialize counters to the values we
* just got.
*/
tabentry->numscans = tabmsg[i].t_counts.t_numscans;
tabentry->tuples_returned = tabmsg[i].t_counts.t_tuples_returned;
tabentry->tuples_fetched = tabmsg[i].t_counts.t_tuples_fetched;
tabentry->tuples_inserted = tabmsg[i].t_counts.t_tuples_inserted;
tabentry->tuples_updated = tabmsg[i].t_counts.t_tuples_updated;
tabentry->tuples_deleted = tabmsg[i].t_counts.t_tuples_deleted;
tabentry->tuples_hot_updated = tabmsg[i].t_counts.t_tuples_hot_updated;
tabentry->n_live_tuples = tabmsg[i].t_counts.t_new_live_tuples;
tabentry->n_dead_tuples = tabmsg[i].t_counts.t_new_dead_tuples;
tabentry->blocks_fetched = tabmsg[i].t_counts.t_blocks_fetched;
tabentry->blocks_hit = tabmsg[i].t_counts.t_blocks_hit;
tabentry->last_anl_tuples = 0;
tabentry->vacuum_timestamp = 0;
tabentry->autovac_vacuum_timestamp = 0;
tabentry->analyze_timestamp = 0;
tabentry->autovac_analyze_timestamp = 0;
}
else
{
/*
* Otherwise add the values to the existing entry.
*/
tabentry->numscans += tabmsg[i].t_counts.t_numscans;
tabentry->tuples_returned += tabmsg[i].t_counts.t_tuples_returned;
tabentry->tuples_fetched += tabmsg[i].t_counts.t_tuples_fetched;
tabentry->tuples_inserted += tabmsg[i].t_counts.t_tuples_inserted;
tabentry->tuples_updated += tabmsg[i].t_counts.t_tuples_updated;
tabentry->tuples_deleted += tabmsg[i].t_counts.t_tuples_deleted;
tabentry->tuples_hot_updated += tabmsg[i].t_counts.t_tuples_hot_updated;
tabentry->n_live_tuples += tabmsg[i].t_counts.t_new_live_tuples;
tabentry->n_dead_tuples += tabmsg[i].t_counts.t_new_dead_tuples;
tabentry->blocks_fetched += tabmsg[i].t_counts.t_blocks_fetched;
tabentry->blocks_hit += tabmsg[i].t_counts.t_blocks_hit;
}
/* Clamp n_live_tuples in case of negative new_live_tuples */
tabentry->n_live_tuples = Max(tabentry->n_live_tuples, 0);
/* Likewise for n_dead_tuples */
tabentry->n_dead_tuples = Max(tabentry->n_dead_tuples, 0);
/*
* Add per-table stats to the per-database entry, too.
*/
dbentry->n_tuples_returned += tabmsg[i].t_counts.t_tuples_returned;
dbentry->n_tuples_fetched += tabmsg[i].t_counts.t_tuples_fetched;
dbentry->n_tuples_inserted += tabmsg[i].t_counts.t_tuples_inserted;
dbentry->n_tuples_updated += tabmsg[i].t_counts.t_tuples_updated;
dbentry->n_tuples_deleted += tabmsg[i].t_counts.t_tuples_deleted;
dbentry->n_blocks_fetched += tabmsg[i].t_counts.t_blocks_fetched;
dbentry->n_blocks_hit += tabmsg[i].t_counts.t_blocks_hit;
}
}
/* ----------
* pgstat_recv_tabpurge() -
*
* Arrange for dead table removal.
* ----------
*/
static void
pgstat_recv_tabpurge(PgStat_MsgTabpurge *msg, int len)
{
PgStat_StatDBEntry *dbentry;
int i;
dbentry = pgstat_get_db_entry(msg->m_databaseid, false);
/*
* No need to purge if we don't even know the database.
*/
if (!dbentry || !dbentry->tables)
return;
/*
* Process all table entries in the message.
*/
for (i = 0; i < msg->m_nentries; i++)
{
/* Remove from hashtable if present; we don't care if it's not. */
(void) hash_search(dbentry->tables,
(void *) &(msg->m_tableid[i]),
HASH_REMOVE, NULL);
}
}
/* ----------
* pgstat_recv_dropdb() -
*
* Arrange for dead database removal
* ----------
*/
static void
pgstat_recv_dropdb(PgStat_MsgDropdb *msg, int len)
{
PgStat_StatDBEntry *dbentry;
/*
* Lookup the database in the hashtable.
*/
dbentry = pgstat_get_db_entry(msg->m_databaseid, false);
/*
* If found, remove it.
*/
if (dbentry)
{
if (dbentry->tables != NULL)
hash_destroy(dbentry->tables);
if (dbentry->functions != NULL)
hash_destroy(dbentry->functions);
if (hash_search(pgStatDBHash,
(void *) &(dbentry->databaseid),
HASH_REMOVE, NULL) == NULL)
ereport(ERROR,
(errmsg("database hash table corrupted "
"during cleanup --- abort")));
}
}
/* ----------
* pgstat_recv_resetcounter() -
*
* Reset the statistics for the specified database.
* ----------
*/
static void
pgstat_recv_resetcounter(PgStat_MsgResetcounter *msg, int len)
{
HASHCTL hash_ctl;
PgStat_StatDBEntry *dbentry;
/*
* Lookup the database in the hashtable. Nothing to do if not there.
*/
dbentry = pgstat_get_db_entry(msg->m_databaseid, false);
if (!dbentry)
return;
/*
* We simply throw away all the database's table entries by recreating a
* new hash table for them.
*/
if (dbentry->tables != NULL)
hash_destroy(dbentry->tables);
if (dbentry->functions != NULL)
hash_destroy(dbentry->functions);
dbentry->tables = NULL;
dbentry->functions = NULL;
dbentry->n_xact_commit = 0;
dbentry->n_xact_rollback = 0;
dbentry->n_blocks_fetched = 0;
dbentry->n_blocks_hit = 0;
memset(&hash_ctl, 0, sizeof(hash_ctl));
hash_ctl.keysize = sizeof(Oid);
hash_ctl.entrysize = sizeof(PgStat_StatTabEntry);
hash_ctl.hash = oid_hash;
dbentry->tables = hash_create("Per-database table",
PGSTAT_TAB_HASH_SIZE,
&hash_ctl,
HASH_ELEM | HASH_FUNCTION);
hash_ctl.keysize = sizeof(Oid);
hash_ctl.entrysize = sizeof(PgStat_StatFuncEntry);
hash_ctl.hash = oid_hash;
dbentry->functions = hash_create("Per-database function",
PGSTAT_FUNCTION_HASH_SIZE,
&hash_ctl,
HASH_ELEM | HASH_FUNCTION);
}
/* ----------
* pgstat_recv_autovac() -
*
* Process an autovacuum signalling message.
* ----------
*/
static void
pgstat_recv_autovac(PgStat_MsgAutovacStart *msg, int len)
{
PgStat_StatDBEntry *dbentry;
/*
* Lookup the database in the hashtable. Don't create the entry if it
* doesn't exist, because autovacuum may be processing a template
* database. If this isn't the case, the database is most likely to have
* an entry already. (If it doesn't, not much harm is done anyway --
* it'll get created as soon as somebody actually uses the database.)
*/
dbentry = pgstat_get_db_entry(msg->m_databaseid, false);
if (dbentry == NULL)
return;
/*
* Store the last autovacuum time in the database entry.
*/
dbentry->last_autovac_time = msg->m_start_time;
}
/* ----------
* pgstat_recv_vacuum() -
*
* Process a VACUUM message.
* ----------
*/
static void
pgstat_recv_vacuum(PgStat_MsgVacuum *msg, int len)
{
PgStat_StatDBEntry *dbentry;
PgStat_StatTabEntry *tabentry;
/*
* Don't create either the database or table entry if it doesn't already
* exist. This avoids bloating the stats with entries for stuff that is
* only touched by vacuum and not by live operations.
*/
dbentry = pgstat_get_db_entry(msg->m_databaseid, false);
if (dbentry == NULL)
return;
tabentry = hash_search(dbentry->tables, &(msg->m_tableoid),
HASH_FIND, NULL);
if (tabentry == NULL)
return;
if (msg->m_autovacuum)
tabentry->autovac_vacuum_timestamp = msg->m_vacuumtime;
else
tabentry->vacuum_timestamp = msg->m_vacuumtime;
if (msg->m_scanned_all)
tabentry->n_live_tuples = msg->m_tuples;
/* Resetting dead_tuples to 0 is an approximation ... */
tabentry->n_dead_tuples = 0;
if (msg->m_analyze)
{
if (msg->m_scanned_all)
tabentry->last_anl_tuples = msg->m_tuples;
else
{
/* last_anl_tuples must never exceed n_live_tuples+n_dead_tuples */
tabentry->last_anl_tuples = Min(tabentry->last_anl_tuples,
tabentry->n_live_tuples);
}
if (msg->m_autovacuum)
tabentry->autovac_analyze_timestamp = msg->m_vacuumtime;
else
tabentry->analyze_timestamp = msg->m_vacuumtime;
}
else
{
/* last_anl_tuples must never exceed n_live_tuples+n_dead_tuples */
tabentry->last_anl_tuples = Min(tabentry->last_anl_tuples,
tabentry->n_live_tuples);
}
}
/* ----------
* pgstat_recv_analyze() -
*
* Process an ANALYZE message.
* ----------
*/
static void
pgstat_recv_analyze(PgStat_MsgAnalyze *msg, int len)
{
PgStat_StatDBEntry *dbentry;
PgStat_StatTabEntry *tabentry;
/*
* Don't create either the database or table entry if it doesn't already
* exist. This avoids bloating the stats with entries for stuff that is
* only touched by analyze and not by live operations.
*/
dbentry = pgstat_get_db_entry(msg->m_databaseid, false);
if (dbentry == NULL)
return;
tabentry = hash_search(dbentry->tables, &(msg->m_tableoid),
HASH_FIND, NULL);
if (tabentry == NULL)
return;
if (msg->m_autovacuum)
tabentry->autovac_analyze_timestamp = msg->m_analyzetime;
else
tabentry->analyze_timestamp = msg->m_analyzetime;
tabentry->n_live_tuples = msg->m_live_tuples;
tabentry->n_dead_tuples = msg->m_dead_tuples;
tabentry->last_anl_tuples = msg->m_live_tuples + msg->m_dead_tuples;
}
/* ----------
* pgstat_recv_bgwriter() -
*
* Process a BGWRITER message.
* ----------
*/
static void
pgstat_recv_bgwriter(PgStat_MsgBgWriter *msg, int len)
{
globalStats.timed_checkpoints += msg->m_timed_checkpoints;
globalStats.requested_checkpoints += msg->m_requested_checkpoints;
globalStats.buf_written_checkpoints += msg->m_buf_written_checkpoints;
globalStats.buf_written_clean += msg->m_buf_written_clean;
globalStats.maxwritten_clean += msg->m_maxwritten_clean;
globalStats.buf_written_backend += msg->m_buf_written_backend;
globalStats.buf_alloc += msg->m_buf_alloc;
}
/*
* GPDB: Lookup the hash table entry for the specified resource queue. If no hash
* table entry exists, initialize it, if the create parameter is true.
* Else, return NULL.
*/
static PgStat_StatQueueEntry *
pgstat_get_queue_entry(Oid queueid, bool create)
{
PgStat_StatQueueEntry *result;
bool found;
HASHACTION action = (create ? HASH_ENTER : HASH_FIND);
/* Lookup or create the hash table entry for this queue */
result = (PgStat_StatQueueEntry *) hash_search(pgStatQueueHash,
&queueid,
action, &found);
if (!create && !found)
return NULL;
/* If not found, initialize the new one. */
if (!found)
{
result->queueid = queueid;
result->n_queries_exec = 0;
result->n_queries_wait = 0;
result->elapsed_exec = 0;
result->elapsed_wait = 0;
}
return result;
}
/* ----------
* pgstat_recv_queuestat() -
*
* Process resource queue activity for a backend.
* ----------
*/
static void
pgstat_recv_queuestat(PgStat_MsgQueuestat *msg, int len)
{
PgStat_StatQueueEntry *queueentry;
/* Get or create an entry for this resource queue. */
queueentry = pgstat_get_queue_entry(msg->m_queueid, true);
/* Update the metrics. */
queueentry->n_queries_exec += msg->m_queries_exec;
queueentry->n_queries_wait += msg->m_queries_wait;
queueentry->elapsed_exec += msg->m_elapsed_exec;
queueentry->elapsed_wait += msg->m_elapsed_wait;
}
/* ----------
* pgstat_init_localportalhash() -
*
* Cache for portal statistics for a backend.
* ----------
*/
void
pgstat_init_localportalhash(void)
{
HASHCTL info;
int hash_flags;
info.keysize = sizeof(uint32);
info.entrysize = sizeof(PgStat_StatPortalEntry);
info.hash = tag_hash;
hash_flags = (HASH_ELEM | HASH_FUNCTION);
localStatPortalHash = hash_create("Local Stat Portal Hash",
1,
&info,
hash_flags);
return;
}
/* ----------
* pgstat_getportalentry() -
*
* Return the (PgStat_StatPortalEntry *) for a given portal (and backend).
* ----------
*/
PgStat_StatPortalEntry *
pgstat_getportalentry(uint32 portalid, Oid queueid)
{
PgStat_StatPortalEntry *portalentry;
bool found;
portalentry = hash_search(localStatPortalHash,
(void *) &portalid,
HASH_ENTER, &found);
Assert(portalentry != NULL);
/* Initialize if this we have not seen this portal before! */
if (!found)
{
portalentry->portalid = portalid;
portalentry->queueentry.queueid = queueid;
portalentry->queueentry.n_queries_exec = 0;
portalentry->queueentry.n_queries_wait = 0;
portalentry->queueentry.elapsed_exec = 0;
portalentry->queueentry.elapsed_wait = 0;
}
return portalentry;
}
/* ----------
* pgstat_report_queuestat() -
*
* Called from tcop/postgres.c to send the so far collected
* per resource queue statistics to the collector.
* ----------
*/
void
pgstat_report_queuestat()
{
HASH_SEQ_STATUS hstat;
PgStat_StatPortalEntry *pentry;
PgStat_MsgQueuestat msg;
if (pgStatSock < 0 || !pgstat_collect_queuelevel)
{
return; /* Not collecting queue stats or collector disabled. */
}
/* Do a sequential scan through the local portal/queue hash*/
hash_seq_init(&hstat, localStatPortalHash);
while ((pentry = (PgStat_StatPortalEntry *) hash_seq_search(&hstat)) != NULL)
{
/* Skip if message payload will be trivial. */
if (pentry->queueentry.n_queries_exec == 0 &&
pentry->queueentry.n_queries_wait == 0 &&
pentry->queueentry.elapsed_exec == 0 &&
pentry->queueentry.elapsed_wait == 0)
continue;
/* Initialize a message to send to the collector. */
pgstat_setheader(&msg.m_hdr, PGSTAT_MTYPE_QUEUESTAT);
msg.m_queueid = pentry->queueentry.queueid;
msg.m_queries_exec = pentry->queueentry.n_queries_exec;
msg.m_queries_wait = pentry->queueentry.n_queries_wait;
msg.m_elapsed_exec = pentry->queueentry.elapsed_exec;
msg.m_elapsed_wait = pentry->queueentry.elapsed_wait;
/* Reset the counters for this entry. */
pentry->queueentry.n_queries_exec = 0;
pentry->queueentry.n_queries_wait = 0;
pentry->queueentry.elapsed_exec = 0;
pentry->queueentry.elapsed_wait = 0;
pgstat_send(&msg, sizeof(msg));
}
}
/* ----------
* pgstat_fetch_stat_queueentry() -
*
* Support function for the SQL-callable pgstat* functions. Returns
* the collected statistics for one resource queue or NULL. NULL doesn't mean
* that the queue doesn't exist, it is just not yet known by the
* collector, so the caller is better off to report ZERO instead.
* ----------
*/
PgStat_StatQueueEntry *
pgstat_fetch_stat_queueentry(Oid queueid)
{
/*
* If not done for this transaction, read the statistics collector stats
* file into some hash tables.
*/
backend_read_statsfile();
/*
* Lookup the requested database; return NULL if not found
*/
return (PgStat_StatQueueEntry *) hash_search(pgStatQueueHash,
(void *) &queueid,
HASH_FIND, NULL);
}
/* ----------
* pgstat_recv_funcstat() -
*
* Count what the backend has done.
* ----------
*/
static void
pgstat_recv_funcstat(PgStat_MsgFuncstat *msg, int len)
{
PgStat_FunctionEntry *funcmsg = &(msg->m_entry[0]);
PgStat_StatDBEntry *dbentry;
PgStat_StatFuncEntry *funcentry;
int i;
bool found;
dbentry = pgstat_get_db_entry(msg->m_databaseid, true);
/*
* Process all function entries in the message.
*/
for (i = 0; i < msg->m_nentries; i++, funcmsg++)
{
funcentry = (PgStat_StatFuncEntry *) hash_search(dbentry->functions,
(void *) &(funcmsg->f_id),
HASH_ENTER, &found);
if (!found)
{
/*
* If it's a new function entry, initialize counters to the values
* we just got.
*/
funcentry->f_numcalls = funcmsg->f_numcalls;
funcentry->f_time = funcmsg->f_time;
funcentry->f_time_self = funcmsg->f_time_self;
}
else
{
/*
* Otherwise add the values to the existing entry.
*/
funcentry->f_numcalls += funcmsg->f_numcalls;
funcentry->f_time += funcmsg->f_time;
funcentry->f_time_self += funcmsg->f_time_self;
}
}
}
/* ----------
* pgstat_recv_funcpurge() -
*
* Arrange for dead function removal.
* ----------
*/
static void
pgstat_recv_funcpurge(PgStat_MsgFuncpurge *msg, int len)
{
PgStat_StatDBEntry *dbentry;
int i;
dbentry = pgstat_get_db_entry(msg->m_databaseid, false);
/*
* No need to purge if we don't even know the database.
*/
if (!dbentry || !dbentry->functions)
return;
/*
* Process all function entries in the message.
*/
for (i = 0; i < msg->m_nentries; i++)
{
/* Remove from hashtable if present; we don't care if it's not. */
(void) hash_search(dbentry->functions,
(void *) &(msg->m_functionid[i]),
HASH_REMOVE, NULL);
}
}