injection_points: Clear waiter slot on error and exit injection_wait() only clears its slot in the waiter array after the wait loop finishes. When the waiting query is canceled or the backend is terminated (wait look has a CHECK_FOR_INTERRUPS), the slot leaks. Later wakeups of the same point then bump the counter of the leaked slot instead of the real waiter, that sleeps forever. Repeated leaks can exhaust all the slots.
The code is changed so as the waiting loop is wrapped with PG_ENSURE_ERROR_CLEANUP, so as the injection point slots, that are shared resources, can be cleaned up on ERROR as much as a FATAL. An isolation test is added: cancel one waiter, terminate another waiter, then check that a later waiter still receives a wakeup. Without the fixed code, the test would fail on timeout. Author: Zsolt Parragi <[email protected]> Discussion: https://postgr.es/m/CAN4CZFO+KF=cc0-ieg28rhqrbp_fts6d4b8b7d7db-pgyp3...@mail.gmail.com Backpatch-through: 17 Branch ------ REL_18_STABLE Details ------- https://git.postgresql.org/pg/commitdiff/bb0a3ca8d218b6c0792235d7306117e5bc36294a Modified Files -------------- src/test/modules/injection_points/Makefile | 1 + .../injection_points/expected/wait_cleanup.out | 87 ++++++++++++++++++++++ .../modules/injection_points/injection_points.c | 39 +++++++--- src/test/modules/injection_points/meson.build | 1 + .../injection_points/specs/wait_cleanup.spec | 50 +++++++++++++ 5 files changed, 166 insertions(+), 12 deletions(-)
