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| author | Heikki Linnakangas <heikki.linnakangas@iki.fi> | 2025-11-06 12:50:10 +0200 |
|---|---|---|
| committer | Heikki Linnakangas <heikki.linnakangas@iki.fi> | 2025-11-06 14:20:48 +0200 |
| commit | daf3d99d2b8bebb3361163a11ef3d232002127c9 (patch) | |
| tree | 386d35c84e32bef55dbaa67bf5aeb5d13ecbb917 /src/backend/storage/ipc/ipci.c | |
| parent | 150e24501bc218057a7b9a24b19a145fa8b5c678 (diff) | |
Add comment to explain why PGReserveSemaphores() is called early
Before commit e25626677f, PGReserveSemaphores() had to be called
before SpinlockSemaInit() because spinlocks were implemented using
semaphores on some platforms (--disable-spinlocks). Add a comment
explaining that.
Author: Ashutosh Bapat <ashutosh.bapat.oss@gmail.com>
Discussion: https://www.postgresql.org/message-id/CAExHW5seSZpPx-znjidVZNzdagGHOk06F+Ds88MpPUbxd1kTaA@mail.gmail.com
Backpatch-to: 18
Diffstat (limited to 'src/backend/storage/ipc/ipci.c')
| -rw-r--r-- | src/backend/storage/ipc/ipci.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/src/backend/storage/ipc/ipci.c b/src/backend/storage/ipc/ipci.c index 10ffce8d174..19f9c774488 100644 --- a/src/backend/storage/ipc/ipci.c +++ b/src/backend/storage/ipc/ipci.c @@ -227,7 +227,9 @@ CreateSharedMemoryAndSemaphores(void) InitShmemAccess(seghdr); /* - * Create semaphores + * Create semaphores. (This is done here for historical reasons. We used + * to support emulating spinlocks with semaphores, which required + * initializing semaphores early.) */ PGReserveSemaphores(numSemas); |