injection_points: Fix incorrect spinlock acquisition Injection points created under injection_points_set_local() are cleaned up by a shmem_exit() callback. The spinlock used by the module would be hold while calling InjectionPointDetach(), which is incorrect as spinlocks should avoid external calls while hold.
This commit changes the shmem_exit() callback to detach the points in three steps with the spinlock acquired twice, knowing that the injection points should be around with the conditions related to them: - Scans for the points to detach in a first loop, while holding the spinlock. - Detach them. - Remove the registered conditions. It is still possible for other processes to detach local points concurrently of the callback. I have wanted to restrict the detach, but Noah has mentioned that he has in mind some cases that may require this capability. No tests in the tree based on injection points need that currently. Thinko in f587338dec87. Reported-by: Noah Misch Reviewed-by: Noah Misch Discussion: https://postgr.es/m/20240501231214...@rfd.leadboat.com Branch ------ master Details ------- https://git.postgresql.org/pg/commitdiff/597f66942d0b18f2f15b478346bc74ae6fdb793b Modified Files -------------- .../modules/injection_points/injection_points.c | 31 ++++++++++++++++++++-- 1 file changed, 29 insertions(+), 2 deletions(-)
