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| author | Nathan Bossart <nathan@postgresql.org> | 2024-01-23 14:20:14 -0600 |
|---|---|---|
| committer | Nathan Bossart <nathan@postgresql.org> | 2024-01-23 14:20:14 -0600 |
| commit | bcd5b4bcbefc8b99be3678cf9c6c990a0c28f68e (patch) | |
| tree | d52f3e76e8a8740086b7f9c146c8297ba3184731 | |
| parent | 79b03dbb3304539c6599593397c6a6b63b6a6ad9 (diff) | |
| download | postgresql-bcd5b4bcbefc8b99be3678cf9c6c990a0c28f68e.tar.gz postgresql-bcd5b4bcbefc8b99be3678cf9c6c990a0c28f68e.zip | |
Fix crash in autoprewarm.
Commit abb0b4fc03 moved the shared state for autoprewarm to a
dynamic shared memory (DSM) segment, but it left apw_detach_shmem()
in the on_shmem_exit callback list for the autoprewarm leader
process. This is a problem because shmem_exit() detaches all the
DSM segments prior to calling the on_shmem_exit callbacks, thus
producing segfaults in the exit path for the autoprewarm leader
process.
To fix, move apw_detach_shmem() to the before_shmem_exit callback
list. This commit also adds a check to pg_prewarm's test that the
server shut down normally. It might be worth making this a common
check for all shutdowns in TAP tests, but that is left as a future
exercise.
Reported-by: Andres Freund
Reviewed-by: Andres Freund, Álvaro Herrera
Discussion: https://postgr.es/m/20240122204117.swton324xcoodnyi%40awork3.anarazel.de
| -rw-r--r-- | contrib/pg_prewarm/autoprewarm.c | 10 | ||||
| -rw-r--r-- | contrib/pg_prewarm/t/001_basic.pl | 6 |
2 files changed, 14 insertions, 2 deletions
diff --git a/contrib/pg_prewarm/autoprewarm.c b/contrib/pg_prewarm/autoprewarm.c index 9ea6c2252ad..06ee21d4963 100644 --- a/contrib/pg_prewarm/autoprewarm.c +++ b/contrib/pg_prewarm/autoprewarm.c @@ -164,8 +164,14 @@ autoprewarm_main(Datum main_arg) if (apw_init_shmem()) first_time = false; - /* Set on-detach hook so that our PID will be cleared on exit. */ - on_shmem_exit(apw_detach_shmem, 0); + /* + * Set on-detach hook so that our PID will be cleared on exit. + * + * NB: Autoprewarm's state is stored in a DSM segment, and DSM segments + * are detached before calling the on_shmem_exit callbacks, so we must put + * apw_detach_shmem in the before_shmem_exit callback list. + */ + before_shmem_exit(apw_detach_shmem, 0); /* * Store our PID in the shared memory area --- unless there's already diff --git a/contrib/pg_prewarm/t/001_basic.pl b/contrib/pg_prewarm/t/001_basic.pl index bcd23a69146..825d3448ee5 100644 --- a/contrib/pg_prewarm/t/001_basic.pl +++ b/contrib/pg_prewarm/t/001_basic.pl @@ -55,4 +55,10 @@ $node->wait_for_log( $node->stop; +# control file should indicate normal shut down +command_like( + [ 'pg_controldata', $node->data_dir() ], + qr/Database cluster state:\s*shut down/, + 'cluster shut down normally'); + done_testing(); |