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Add lock_timeout configuration parameter.

This GUC allows limiting the time spent waiting to acquire any one
heavyweight lock.

In support of this, improve the recently-added timeout infrastructure
to permit efficiently enabling or disabling multiple timeouts at once.
That reduces the performance hit from turning on lock_timeout, though
it's still not zero.

Zoltán Böszörményi, reviewed by Tom Lane,
Stephen Frost, and Hari Babu
This commit is contained in:
Tom Lane
2013-03-16 23:22:17 -04:00
parent d2bef5f7db
commit d43837d030
16 changed files with 511 additions and 116 deletions

View File

@@ -55,6 +55,7 @@
/* GUC variables */
int DeadlockTimeout = 1000;
int StatementTimeout = 0;
int LockTimeout = 0;
bool log_lock_waits = false;
/* Pointer to this process's PGPROC and PGXACT structs, if any */
@@ -665,6 +666,7 @@ void
LockErrorCleanup(void)
{
LWLockId partitionLock;
DisableTimeoutParams timeouts[2];
AbortStrongLockAcquire();
@@ -672,8 +674,19 @@ LockErrorCleanup(void)
if (lockAwaited == NULL)
return;
/* Turn off the deadlock timer, if it's still running (see ProcSleep) */
disable_timeout(DEADLOCK_TIMEOUT, false);
/*
* Turn off the deadlock and lock timeout timers, if they are still
* running (see ProcSleep). Note we must preserve the LOCK_TIMEOUT
* indicator flag, since this function is executed before
* ProcessInterrupts when responding to SIGINT; else we'd lose the
* knowledge that the SIGINT came from a lock timeout and not an external
* source.
*/
timeouts[0].id = DEADLOCK_TIMEOUT;
timeouts[0].keep_indicator = false;
timeouts[1].id = LOCK_TIMEOUT;
timeouts[1].keep_indicator = true;
disable_timeouts(timeouts, 2);
/* Unlink myself from the wait queue, if on it (might not be anymore!) */
partitionLock = LockHashPartitionLock(lockAwaited->hashcode);
@@ -1072,8 +1085,24 @@ ProcSleep(LOCALLOCK *locallock, LockMethod lockMethodTable)
*
* By delaying the check until we've waited for a bit, we can avoid
* running the rather expensive deadlock-check code in most cases.
*
* If LockTimeout is set, also enable the timeout for that. We can save a
* few cycles by enabling both timeout sources in one call.
*/
enable_timeout_after(DEADLOCK_TIMEOUT, DeadlockTimeout);
if (LockTimeout > 0)
{
EnableTimeoutParams timeouts[2];
timeouts[0].id = DEADLOCK_TIMEOUT;
timeouts[0].type = TMPARAM_AFTER;
timeouts[0].delay_ms = DeadlockTimeout;
timeouts[1].id = LOCK_TIMEOUT;
timeouts[1].type = TMPARAM_AFTER;
timeouts[1].delay_ms = LockTimeout;
enable_timeouts(timeouts, 2);
}
else
enable_timeout_after(DEADLOCK_TIMEOUT, DeadlockTimeout);
/*
* If someone wakes us between LWLockRelease and PGSemaphoreLock,
@@ -1240,9 +1269,20 @@ ProcSleep(LOCALLOCK *locallock, LockMethod lockMethodTable)
} while (myWaitStatus == STATUS_WAITING);
/*
* Disable the timer, if it's still running
* Disable the timers, if they are still running
*/
disable_timeout(DEADLOCK_TIMEOUT, false);
if (LockTimeout > 0)
{
DisableTimeoutParams timeouts[2];
timeouts[0].id = DEADLOCK_TIMEOUT;
timeouts[0].keep_indicator = false;
timeouts[1].id = LOCK_TIMEOUT;
timeouts[1].keep_indicator = false;
disable_timeouts(timeouts, 2);
}
else
disable_timeout(DEADLOCK_TIMEOUT, false);
/*
* Re-acquire the lock table's partition lock. We have to do this to hold