diff options
| -rw-r--r-- | contrib/pg_prewarm/autoprewarm.c | 30 |
1 files changed, 25 insertions, 5 deletions
diff --git a/contrib/pg_prewarm/autoprewarm.c b/contrib/pg_prewarm/autoprewarm.c index bfcea9bde3f..8d6c81998ca 100644 --- a/contrib/pg_prewarm/autoprewarm.c +++ b/contrib/pg_prewarm/autoprewarm.c @@ -153,6 +153,7 @@ void autoprewarm_main(Datum main_arg) { bool first_time = true; + bool final_dump_allowed = true; TimestampTz last_dump_time = 0; /* Establish signal handlers; once that's done, unblock signals. */ @@ -193,10 +194,15 @@ autoprewarm_main(Datum main_arg) * There's not much point in performing a dump immediately after we finish * preloading; so, if we do end up preloading, consider the last dump time * to be equal to the current time. + * + * If apw_load_buffers() is terminated early by a shutdown request, + * prevent dumping out our state below the loop, because we'd effectively + * just truncate the saved state to however much we'd managed to preload. */ if (first_time) { apw_load_buffers(); + final_dump_allowed = !ShutdownRequestPending; last_dump_time = GetCurrentTimestamp(); } @@ -254,7 +260,8 @@ autoprewarm_main(Datum main_arg) * Dump one last time. We assume this is probably the result of a system * shutdown, although it's possible that we've merely been terminated. */ - apw_dump_now(true, true); + if (final_dump_allowed) + apw_dump_now(true, true); } /* @@ -388,6 +395,18 @@ apw_load_buffers(void) break; /* + * Likewise, don't launch if we've already been told to shut down. + * + * There is a race condition here: if the postmaster has received a + * fast-shutdown signal, but we've not heard about it yet, then the + * postmaster will ignore our worker start request and we'll wait + * forever. However, that's a bug in the general background-worker + * logic, not the fault of this module. + */ + if (ShutdownRequestPending) + break; + + /* * Start a per-database worker to load blocks for this database; this * function will return once the per-database worker exits. */ @@ -404,10 +423,11 @@ apw_load_buffers(void) apw_state->pid_using_dumpfile = InvalidPid; LWLockRelease(&apw_state->lock); - /* Report our success. */ - ereport(LOG, - (errmsg("autoprewarm successfully prewarmed %d of %d previously-loaded blocks", - apw_state->prewarmed_blocks, num_elements))); + /* Report our success, if we were able to finish. */ + if (!ShutdownRequestPending) + ereport(LOG, + (errmsg("autoprewarm successfully prewarmed %d of %d previously-loaded blocks", + apw_state->prewarmed_blocks, num_elements))); } /* |