diff --git a/src/backend/postmaster/pgstat.c b/src/backend/postmaster/pgstat.c
index 788dedb9ee97c5981bcfeae20e9cc050f9924330..c40b90b5993ad745795793e0eaf8acfe060adcc8 100644
--- a/src/backend/postmaster/pgstat.c
+++ b/src/backend/postmaster/pgstat.c
@@ -13,7 +13,7 @@
*
* Copyright (c) 2001-2006, PostgreSQL Global Development Group
*
- * $PostgreSQL: pgsql/src/backend/postmaster/pgstat.c,v 1.123 2006/04/20 10:51:32 momjian Exp $
+ * $PostgreSQL: pgsql/src/backend/postmaster/pgstat.c,v 1.124 2006/04/27 00:06:58 momjian Exp $
* ----------
*/
#include "postgres.h"
@@ -28,6 +28,7 @@
#include <arpa/inet.h>
#include <signal.h>
#include <time.h>
+#include <sys/stat.h>
#include "pgstat.h"
@@ -66,12 +67,15 @@
* Timer definitions.
* ----------
*/
-#define PGSTAT_STAT_INTERVAL 500 /* How often to write the status file;
- * in milliseconds. */
-#define PGSTAT_RESTART_INTERVAL 60 /* How often to attempt to restart a
- * failed statistics collector; in
- * seconds. */
+/* How often to write the status file, in milliseconds. */
+#define PGSTAT_STAT_INTERVAL (5*60*1000)
+
+/*
+ * How often to attempt to restart a failed statistics collector; in ms.
+ * Must be at least PGSTAT_STAT_INTERVAL.
+ */
+#define PGSTAT_RESTART_INTERVAL (5*60*1000)
/* ----------
* Amount of space reserved in pgstat_recvbuffer().
@@ -172,11 +176,12 @@ static void pgstat_drop_database(Oid databaseid);
static void pgstat_write_statsfile(void);
static void pgstat_read_statsfile(HTAB **dbhash, Oid onlydb,
PgStat_StatBeEntry **betab,
- int *numbackends);
+ int *numbackends, bool rewrite);
static void backend_read_statsfile(void);
static void pgstat_setheader(PgStat_MsgHdr *hdr, StatMsgType mtype);
static void pgstat_send(void *msg, int len);
+static void pgstat_send_rewrite(void);
static void pgstat_recv_bestart(PgStat_MsgBestart *msg, int len);
static void pgstat_recv_beterm(PgStat_MsgBeterm *msg, int len);
@@ -1449,6 +1454,24 @@ pgstat_send(void *msg, int len)
#endif
}
+/*
+ * pgstat_send_rewrite() -
+ *
+ * Send a command to the collector to rewrite the stats file.
+ * ----------
+ */
+static void
+pgstat_send_rewrite(void)
+{
+ PgStat_MsgRewrite msg;
+
+ if (pgStatSock < 0)
+ return;
+
+ pgstat_setheader(&msg.m_hdr, PGSTAT_MTYPE_REWRITE);
+ pgstat_send(&msg, sizeof(msg));
+}
+
/* ----------
* PgstatBufferMain() -
@@ -1549,7 +1572,7 @@ PgstatCollectorMain(int argc, char *argv[])
fd_set rfds;
int readPipe;
int len = 0;
- struct itimerval timeout;
+ struct itimerval timeout, canceltimeout;
bool need_timer = false;
MyProcPid = getpid(); /* reset MyProcPid */
@@ -1604,12 +1627,15 @@ PgstatCollectorMain(int argc, char *argv[])
timeout.it_value.tv_sec = PGSTAT_STAT_INTERVAL / 1000;
timeout.it_value.tv_usec = PGSTAT_STAT_INTERVAL % 1000;
+ /* Values set to zero will cancel the active timer */
+ MemSet(&canceltimeout, 0, sizeof(struct itimerval));
+
/*
* Read in an existing statistics stats file or initialize the stats to
* zero.
*/
pgStatRunningInCollector = true;
- pgstat_read_statsfile(&pgStatDBHash, InvalidOid, NULL, NULL);
+ pgstat_read_statsfile(&pgStatDBHash, InvalidOid, NULL, NULL, false);
/*
* Create the known backends table
@@ -1764,6 +1790,12 @@ PgstatCollectorMain(int argc, char *argv[])
pgstat_recv_analyze((PgStat_MsgAnalyze *) &msg, nread);
break;
+ case PGSTAT_MTYPE_REWRITE:
+ need_statwrite = true;
+ /* Disable the timer - it will be restarted on next data update */
+ setitimer(ITIMER_REAL, &canceltimeout, NULL);
+ break;
+
default:
break;
}
@@ -2344,7 +2376,7 @@ comparePids(const void *v1, const void *v2)
*/
static void
pgstat_read_statsfile(HTAB **dbhash, Oid onlydb,
- PgStat_StatBeEntry **betab, int *numbackends)
+ PgStat_StatBeEntry **betab, int *numbackends, bool rewrite)
{
PgStat_StatDBEntry *dbentry;
PgStat_StatDBEntry dbbuf;
@@ -2363,6 +2395,71 @@ pgstat_read_statsfile(HTAB **dbhash, Oid onlydb,
MemoryContext use_mcxt;
int mcxt_flags;
+
+ if (rewrite)
+ {
+ /*
+ * To force a rewrite of the stats file from the collector, send
+ * a REWRITE message to the stats collector. Then wait for the file
+ * to change. On Unix, we wait for the inode to change (as the file
+ * is renamed into place from a different file). Win32 has no concept
+ * of inodes, so we wait for the date on the file to change instead.
+ * We can do this on win32 because we have high-res timing on the
+ * file dates, but we can't on unix, because it has 1sec resolution
+ * on the fields in struct stat.
+ */
+ int i;
+#ifndef WIN32
+ struct stat st1, st2;
+
+ if (stat(PGSTAT_STAT_FILENAME, &st1))
+ {
+ /* Assume no file there yet */
+ st1.st_ino = 0;
+ }
+ st2.st_ino = 0;
+#else
+ WIN32_FILE_ATTRIBUTE_DATA fd1, fd2;
+
+ if (!GetFileAttributesEx(PGSTAT_STAT_FILENAME, GetFileExInfoStandard, &fd1))
+ {
+ fd1.ftLastWriteTime.dwLowDateTime = 0;
+ fd1.ftLastWriteTime.dwHighDateTime = 0;
+ }
+ fd2.ftLastWriteTime.dwLowDateTime = 0;
+ fd2.ftLastWriteTime.dwHighDateTime = 0;
+#endif
+
+
+ /* Send rewrite message */
+ pgstat_send_rewrite();
+
+ /* Now wait for the file to change */
+ for (i=0; i < 50; i++)
+ {
+#ifndef WIN32
+ if (!stat(PGSTAT_STAT_FILENAME, &st2))
+ {
+ if (st2.st_ino != st1.st_ino)
+ break;
+ }
+#else
+ if (GetFileAttributesEx(PGSTAT_STAT_FILENAME, GetFileExInfoStandard, &fd2))
+ {
+ if (fd1.ftLastWriteTime.dwLowDateTime != fd2.ftLastWriteTime.dwLowDateTime ||
+ fd1.ftLastWriteTime.dwHighDateTime != fd2.ftLastWriteTime.dwHighDateTime)
+ break;
+ }
+#endif
+
+ pg_usleep(50000);
+ }
+ if (i >= 50)
+ ereport(WARNING,
+ (errmsg("pgstat update timeout")));
+ /* Fallthrough and read the old file anyway - old data better than no data */
+ }
+
/*
* If running in the collector or the autovacuum process, we use the
* DynaHashCxt memory context. If running in a backend, we use the
@@ -2681,7 +2778,7 @@ backend_read_statsfile(void)
return;
Assert(!pgStatRunningInCollector);
pgstat_read_statsfile(&pgStatDBHash, InvalidOid,
- &pgStatBeTable, &pgStatNumBackends);
+ &pgStatBeTable, &pgStatNumBackends, true);
}
else
{
@@ -2691,7 +2788,7 @@ backend_read_statsfile(void)
{
Assert(!pgStatRunningInCollector);
pgstat_read_statsfile(&pgStatDBHash, MyDatabaseId,
- &pgStatBeTable, &pgStatNumBackends);
+ &pgStatBeTable, &pgStatNumBackends, true);
pgStatDBHashXact = topXid;
}
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 00631b3e12b7b9ef0bde89e8d6b01505f2dfbc1e..4497e4d1f58fd80a18fd7d423bdbc57ff0dd1253 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -5,7 +5,7 @@
*
* Copyright (c) 2001-2006, PostgreSQL Global Development Group
*
- * $PostgreSQL: pgsql/src/include/pgstat.h,v 1.43 2006/04/06 20:38:00 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/pgstat.h,v 1.44 2006/04/27 00:06:59 momjian Exp $
* ----------
*/
#ifndef PGSTAT_H
@@ -32,7 +32,8 @@ typedef enum StatMsgType
PGSTAT_MTYPE_RESETCOUNTER,
PGSTAT_MTYPE_AUTOVAC_START,
PGSTAT_MTYPE_VACUUM,
- PGSTAT_MTYPE_ANALYZE
+ PGSTAT_MTYPE_ANALYZE,
+ PGSTAT_MTYPE_REWRITE
} StatMsgType;
/* ----------
@@ -107,6 +108,15 @@ typedef struct PgStat_MsgDummy
char m_dummy[512];
} PgStat_MsgDummy;
+/* ----------
+ * PgStat_MsgRewrite Sent by backends to cause a rewrite of the stats file
+ * ----------
+ */
+typedef struct Pgstat_MsgRewrite
+{
+ PgStat_MsgHdr m_hdr;
+} PgStat_MsgRewrite;
+
/* ----------
* PgStat_MsgBestart Sent by the backend on startup
* ----------