Bruce Momjian wrote:
> Tom Lane wrote:
> A second improvement I discovered is that the statistics collector is
> calling gettimeofday() for every packet received, so it can determine
> the timeout for the select() call to write the flat file. I removed
> that behavior and instead used setitimer() to issue a SIGINT every
> 500ms, which was the original behavior. This eliminates the
> gettimeofday() call and makes the code cleaner. Second patch attached.
I have applied this second patch, with a few small stylistic
improvements.
--
Bruce Momjian | http://candle.pha.pa.us
pgman@candle.pha.pa.us | (610) 359-1001
+ If your life is a hard drive, | 13 Roberts Road
+ Christ can be your backup. | Newtown Square, Pennsylvania 19073
Index: src/backend/postmaster/pgstat.c
===================================================================
RCS file: /cvsroot/pgsql/src/backend/postmaster/pgstat.c,v
retrieving revision 1.116
diff -c -c -r1.116 pgstat.c
*** src/backend/postmaster/pgstat.c 2 Jan 2006 00:58:00 -0000 1.116
--- src/backend/postmaster/pgstat.c 3 Jan 2006 16:26:04 -0000
***************
*** 117,123 ****
static long pgStatNumMessages = 0;
! static bool pgStatRunningInCollector = FALSE;
/*
* Place where backends store per-table info to be sent to the collector.
--- 117,123 ----
static long pgStatNumMessages = 0;
! static bool pgStatRunningInCollector = false;
/*
* Place where backends store per-table info to be sent to the collector.
***************
*** 145,150 ****
--- 145,151 ----
static PgStat_StatBeEntry *pgStatBeTable = NULL;
static int pgStatNumBackends = 0;
+ static volatile bool need_statwrite;
/* ----------
* Local function forward declarations
***************
*** 164,169 ****
--- 165,171 ----
NON_EXEC_STATIC void PgstatBufferMain(int argc, char *argv[]);
NON_EXEC_STATIC void PgstatCollectorMain(int argc, char *argv[]);
+ static void force_statwrite(SIGNAL_ARGS);
static void pgstat_recvbuffer(void);
static void pgstat_exit(SIGNAL_ARGS);
static void pgstat_die(SIGNAL_ARGS);
***************
*** 1548,1560 ****
PgStat_Msg msg;
fd_set rfds;
int readPipe;
- int nready;
int len = 0;
! struct timeval timeout;
! struct timeval next_statwrite;
! bool need_statwrite;
HASHCTL hash_ctl;
!
MyProcPid = getpid(); /* reset MyProcPid */
/*
--- 1550,1560 ----
PgStat_Msg msg;
fd_set rfds;
int readPipe;
int len = 0;
! struct itimerval timeval;
HASHCTL hash_ctl;
! bool need_timer = false;
!
MyProcPid = getpid(); /* reset MyProcPid */
/*
***************
*** 1572,1578 ****
/* kluge to allow buffer process to kill collector; FIXME */
pqsignal(SIGQUIT, pgstat_exit);
#endif
! pqsignal(SIGALRM, SIG_IGN);
pqsignal(SIGPIPE, SIG_IGN);
pqsignal(SIGUSR1, SIG_IGN);
pqsignal(SIGUSR2, SIG_IGN);
--- 1572,1578 ----
/* kluge to allow buffer process to kill collector; FIXME */
pqsignal(SIGQUIT, pgstat_exit);
#endif
! pqsignal(SIGALRM, force_statwrite);
pqsignal(SIGPIPE, SIG_IGN);
pqsignal(SIGUSR1, SIG_IGN);
pqsignal(SIGUSR2, SIG_IGN);
***************
*** 1597,1613 ****
init_ps_display("stats collector process", "", "");
set_ps_display("");
! /*
! * Arrange to write the initial status file right away
! */
! gettimeofday(&next_statwrite, NULL);
! need_statwrite = TRUE;
/*
* Read in an existing statistics stats file or initialize the stats to
* zero.
*/
! pgStatRunningInCollector = TRUE;
pgstat_read_statsfile(&pgStatDBHash, InvalidOid, NULL, NULL);
/*
--- 1597,1613 ----
init_ps_display("stats collector process", "", "");
set_ps_display("");
! need_statwrite = true;
!
! MemSet(&timeval, 0, sizeof(struct itimerval));
! timeval.it_value.tv_sec = PGSTAT_STAT_INTERVAL / 1000;
! timeval.it_value.tv_usec = PGSTAT_STAT_INTERVAL % 1000;
/*
* Read in an existing statistics stats file or initialize the stats to
* zero.
*/
! pgStatRunningInCollector = true;
pgstat_read_statsfile(&pgStatDBHash, InvalidOid, NULL, NULL);
/*
***************
*** 1634,1667 ****
*/
for (;;)
{
- /*
- * If we need to write the status file again (there have been
changes
- * in the statistics since we wrote it last) calculate the
timeout
- * until we have to do so.
- */
if (need_statwrite)
{
! struct timeval now;
!
! gettimeofday(&now, NULL);
! /* avoid assuming that tv_sec is signed */
! if (now.tv_sec > next_statwrite.tv_sec ||
! (now.tv_sec == next_statwrite.tv_sec &&
! now.tv_usec >= next_statwrite.tv_usec))
! {
! timeout.tv_sec = 0;
! timeout.tv_usec = 0;
! }
! else
! {
! timeout.tv_sec = next_statwrite.tv_sec -
now.tv_sec;
! timeout.tv_usec = next_statwrite.tv_usec -
now.tv_usec;
! if (timeout.tv_usec < 0)
! {
! timeout.tv_sec--;
! timeout.tv_usec += 1000000;
! }
! }
}
/*
--- 1634,1644 ----
*/
for (;;)
{
if (need_statwrite)
{
! pgstat_write_statsfile();
! need_statwrite = false;
! need_timer = true;
}
/*
***************
*** 1673,1681 ****
/*
* Now wait for something to do.
*/
! nready = select(readPipe + 1, &rfds, NULL, NULL,
! (need_statwrite) ? &timeout :
NULL);
! if (nready < 0)
{
if (errno == EINTR)
continue;
--- 1650,1656 ----
/*
* Now wait for something to do.
*/
! if (select(readPipe + 1, &rfds, NULL, NULL, NULL) < 0)
{
if (errno == EINTR)
continue;
***************
*** 1685,1702 ****
}
/*
- * If there are no descriptors ready, our timeout for writing
the
- * stats file happened.
- */
- if (nready == 0)
- {
- pgstat_write_statsfile();
- need_statwrite = FALSE;
-
- continue;
- }
-
- /*
* Check if there is a new statistics message to collect.
*/
if (FD_ISSET(readPipe, &rfds))
--- 1660,1665 ----
***************
*** 1813,1829 ****
*/
pgStatNumMessages++;
! /*
! * If this is the first message after we wrote the
stats file the
! * last time, setup the timeout that it'd be written.
! */
! if (!need_statwrite)
{
! gettimeofday(&next_statwrite, NULL);
! next_statwrite.tv_usec +=
((PGSTAT_STAT_INTERVAL) * 1000);
! next_statwrite.tv_sec +=
(next_statwrite.tv_usec / 1000000);
! next_statwrite.tv_usec %= 1000000;
! need_statwrite = TRUE;
}
}
--- 1776,1787 ----
*/
pgStatNumMessages++;
! if (need_timer)
{
! if (setitimer(ITIMER_REAL, &timeval, NULL))
! ereport(ERROR,
! (errmsg("unable to set
statistics collector timer: %m")));
! need_timer = false;
}
}
***************
*** 1848,1853 ****
--- 1806,1818 ----
}
+ static void
+ force_statwrite(SIGNAL_ARGS)
+ {
+ need_statwrite = true;
+ }
+
+
/* ----------
* pgstat_recvbuffer() -
*
***************
*** 1865,1871 ****
struct timeval timeout;
int writePipe = pgStatPipe[1];
int maxfd;
- int nready;
int len;
int xfr;
int frm;
--- 1830,1835 ----
***************
*** 1907,1912 ****
--- 1871,1884 ----
msgbuffer = (char *) palloc(PGSTAT_RECVBUFFERSZ);
/*
+ * Wait for some work to do; but not for more than 10 seconds. (This
+ * determines how quickly we will shut down after an ungraceful
+ * postmaster termination; so it needn't be very fast.)
+ */
+ timeout.tv_sec = 10;
+ timeout.tv_usec = 0;
+
+ /*
* Loop forever
*/
for (;;)
***************
*** 1946,1961 ****
maxfd = writePipe;
}
! /*
! * Wait for some work to do; but not for more than 10 seconds.
(This
! * determines how quickly we will shut down after an ungraceful
! * postmaster termination; so it needn't be very fast.)
! */
! timeout.tv_sec = 10;
! timeout.tv_usec = 0;
!
! nready = select(maxfd + 1, &rfds, &wfds, NULL, &timeout);
! if (nready < 0)
{
if (errno == EINTR)
continue;
--- 1918,1924 ----
maxfd = writePipe;
}
! if (select(maxfd + 1, &rfds, &wfds, NULL, &timeout) < 0)
{
if (errno == EINTR)
continue;
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