diff options
Diffstat (limited to 'src/backend/utils/misc/timeout.c')
| -rw-r--r-- | src/backend/utils/misc/timeout.c | 19 |
1 files changed, 16 insertions, 3 deletions
diff --git a/src/backend/utils/misc/timeout.c b/src/backend/utils/misc/timeout.c index ac570730337..6f5e08bc302 100644 --- a/src/backend/utils/misc/timeout.c +++ b/src/backend/utils/misc/timeout.c @@ -71,11 +71,12 @@ static volatile sig_atomic_t alarm_enabled = false; /* * State recording if and when we next expect the interrupt to fire. + * (signal_due_at is valid only when signal_pending is true.) * Note that the signal handler will unconditionally reset signal_pending to * false, so that can change asynchronously even when alarm_enabled is false. */ static volatile sig_atomic_t signal_pending = false; -static TimestampTz signal_due_at = 0; /* valid only when signal_pending */ +static volatile TimestampTz signal_due_at = 0; /***************************************************************************** @@ -218,9 +219,21 @@ schedule_alarm(TimestampTz now) MemSet(&timeval, 0, sizeof(struct itimerval)); /* + * If we think there's a signal pending, but current time is more than + * 10ms past when the signal was due, then assume that the timeout + * request got lost somehow; clear signal_pending so that we'll reset + * the interrupt request below. (10ms corresponds to the worst-case + * timeout granularity on modern systems.) It won't hurt us if the + * interrupt does manage to fire between now and when we reach the + * setitimer() call. + */ + if (signal_pending && now > signal_due_at + 10 * 1000) + signal_pending = false; + + /* * Get the time remaining till the nearest pending timeout. If it is - * negative, assume that we somehow missed an interrupt, and force - * signal_pending off. This gives us a chance to recover if the + * negative, assume that we somehow missed an interrupt, and clear + * signal_pending. This gives us another chance to recover if the * kernel drops a timeout request for some reason. */ nearest_timeout = active_timeouts[0]->fin_time; |