]> granicus.if.org Git - postgresql/commit
Add WL_EXIT_ON_PM_DEATH pseudo-event.
authorThomas Munro <tmunro@postgresql.org>
Fri, 23 Nov 2018 07:16:41 +0000 (20:16 +1300)
committerThomas Munro <tmunro@postgresql.org>
Fri, 23 Nov 2018 07:46:34 +0000 (20:46 +1300)
commitcfdf4dc4fc9635ac8bf6eaaa5dbbcd364ab29f0c
treec1e3c40912c5f9274fb9381bea1082f6a2cc2296
parentd392e9bdea957964e1fa6a5481e5adb5904d759a
Add WL_EXIT_ON_PM_DEATH pseudo-event.

Users of the WaitEventSet and WaitLatch() APIs can now choose between
asking for WL_POSTMASTER_DEATH and then handling it explicitly, or asking
for WL_EXIT_ON_PM_DEATH to trigger immediate exit on postmaster death.
This reduces code duplication, since almost all callers want the latter.

Repair all code that was previously ignoring postmaster death completely,
or requesting the event but ignoring it, or requesting the event but then
doing an unconditional PostmasterIsAlive() call every time through its
event loop (which is an expensive syscall on platforms for which we don't
have USE_POSTMASTER_DEATH_SIGNAL support).

Assert that callers of WaitLatchXXX() under the postmaster remember to
ask for either WL_POSTMASTER_DEATH or WL_EXIT_ON_PM_DEATH, to prevent
future bugs.

The only process that doesn't handle postmaster death is syslogger.  It
waits until all backends holding the write end of the syslog pipe
(including the postmaster) have closed it by exiting, to be sure to
capture any parting messages.  By using the WaitEventSet API directly
it avoids the new assertion, and as a by-product it may be slightly
more efficient on platforms that have epoll().

Author: Thomas Munro
Reviewed-by: Kyotaro Horiguchi, Heikki Linnakangas, Tom Lane
Discussion: https://postgr.es/m/CAEepm%3D1TCviRykkUb69ppWLr_V697rzd1j3eZsRMmbXvETfqbQ%40mail.gmail.com,
            https://postgr.es/m/CAEepm=2LqHzizbe7muD7-2yHUbTOoF7Q+qkSD5Q41kuhttRTwA@mail.gmail.com
32 files changed:
- [new file with mode: 0644]
contrib/pg_prewarm/autoprewarm.c
contrib/postgres_fdw/connection.c
src/backend/access/transam/parallel.c
src/backend/access/transam/xlog.c
src/backend/access/transam/xlogfuncs.c
src/backend/executor/nodeGather.c
src/backend/libpq/be-secure-openssl.c
src/backend/libpq/pqmq.c
src/backend/postmaster/autovacuum.c
src/backend/postmaster/bgwriter.c
src/backend/postmaster/checkpointer.c
src/backend/postmaster/pgarch.c
src/backend/postmaster/syslogger.c
src/backend/postmaster/walwriter.c
src/backend/replication/basebackup.c
src/backend/replication/libpqwalreceiver/libpqwalreceiver.c
src/backend/replication/logical/launcher.c
src/backend/replication/logical/tablesync.c
src/backend/replication/logical/worker.c
src/backend/replication/syncrep.c
src/backend/replication/walreceiver.c
src/backend/replication/walsender.c
src/backend/storage/ipc/latch.c
src/backend/storage/ipc/shm_mq.c
src/backend/storage/lmgr/condition_variable.c
src/backend/storage/lmgr/proc.c
src/backend/utils/adt/misc.c
src/include/storage/latch.h
src/test/modules/test_shm_mq/setup.c
src/test/modules/test_shm_mq/test.c
src/test/modules/worker_spi/worker_spi.c