From 60c879adc2540dad404a05e7f2c20957573b4211 Mon Sep 17 00:00:00 2001 From: Andres Freund Date: Wed, 14 Jan 2026 13:54:00 -0500 Subject: [PATCH v11 4/7] lwlock: Remove support for disowned lwlwocks This reverts commit f8d7f29b3e81db59b95e4b5baaa6943178c89fd8, plus parts of subsequent commits fixing a typo an a parameter name. Support for disowned lwlocks was added for the benefit of AIO, to be able to have content locks "owned" by the AIO subsystem. But as of commit FIXME-XXX-UPDATEME, content locks do not use lwlocks anymore. It does not seem particularly likely that we need this facility outside of the AIO use-case, therefore remove the now unused functions. I did choose to keep the comment added in the aforementioned commit about lock->owner intentionally being left pointing to the last owner. --- src/include/storage/lwlock.h | 2 - src/backend/storage/lmgr/lwlock.c | 71 +++---------------------------- 2 files changed, 6 insertions(+), 67 deletions(-) diff --git a/src/include/storage/lwlock.h b/src/include/storage/lwlock.h index df589902adc..9a0290391d0 100644 --- a/src/include/storage/lwlock.h +++ b/src/include/storage/lwlock.h @@ -127,8 +127,6 @@ extern bool LWLockAcquireOrWait(LWLock *lock, LWLockMode mode); extern void LWLockRelease(LWLock *lock); extern void LWLockReleaseClearVar(LWLock *lock, pg_atomic_uint64 *valptr, uint64 val); extern void LWLockReleaseAll(void); -extern void LWLockDisown(LWLock *lock); -extern void LWLockReleaseDisowned(LWLock *lock, LWLockMode mode); extern bool LWLockHeldByMe(LWLock *lock); extern bool LWLockAnyHeldByMe(LWLock *lock, int nlocks, size_t stride); extern bool LWLockHeldByMeInMode(LWLock *lock, LWLockMode mode); diff --git a/src/backend/storage/lmgr/lwlock.c b/src/backend/storage/lmgr/lwlock.c index 2ee0339c52e..a133c97b992 100644 --- a/src/backend/storage/lmgr/lwlock.c +++ b/src/backend/storage/lmgr/lwlock.c @@ -1783,25 +1783,18 @@ LWLockUpdateVar(LWLock *lock, pg_atomic_uint64 *valptr, uint64 val) /* - * Stop treating lock as held by current backend. - * - * This is the code that can be shared between actually releasing a lock - * (LWLockRelease()) and just not tracking ownership of the lock anymore - * without releasing the lock (LWLockDisown()). - * - * Returns the mode in which the lock was held by the current backend. - * - * NB: This does not call RESUME_INTERRUPTS(), but leaves that responsibility - * of the caller. + * LWLockRelease - release a previously acquired lock * * NB: This will leave lock->owner pointing to the current backend (if * LOCK_DEBUG is set). This is somewhat intentional, as it makes it easier to * debug cases of missing wakeups during lock release. */ -static inline LWLockMode -LWLockDisownInternal(LWLock *lock) +void +LWLockRelease(LWLock *lock) { LWLockMode mode; + uint32 oldstate; + bool check_waiters; int i; /* @@ -1821,18 +1814,7 @@ LWLockDisownInternal(LWLock *lock) for (; i < num_held_lwlocks; i++) held_lwlocks[i] = held_lwlocks[i + 1]; - return mode; -} - -/* - * Helper function to release lock, shared between LWLockRelease() and - * LWLockReleaseDisowned(). - */ -static void -LWLockReleaseInternal(LWLock *lock, LWLockMode mode) -{ - uint32 oldstate; - bool check_waiters; + PRINT_LWDEBUG("LWLockRelease", lock, mode); /* * Release my hold on lock, after that it can immediately be acquired by @@ -1870,38 +1852,6 @@ LWLockReleaseInternal(LWLock *lock, LWLockMode mode) LOG_LWDEBUG("LWLockRelease", lock, "releasing waiters"); LWLockWakeup(lock); } -} - - -/* - * Stop treating lock as held by current backend. - * - * After calling this function it's the callers responsibility to ensure that - * the lock gets released (via LWLockReleaseDisowned()), even in case of an - * error. This only is desirable if the lock is going to be released in a - * different process than the process that acquired it. - */ -void -LWLockDisown(LWLock *lock) -{ - LWLockDisownInternal(lock); - - RESUME_INTERRUPTS(); -} - -/* - * LWLockRelease - release a previously acquired lock - */ -void -LWLockRelease(LWLock *lock) -{ - LWLockMode mode; - - mode = LWLockDisownInternal(lock); - - PRINT_LWDEBUG("LWLockRelease", lock, mode); - - LWLockReleaseInternal(lock, mode); /* * Now okay to allow cancel/die interrupts. @@ -1909,15 +1859,6 @@ LWLockRelease(LWLock *lock) RESUME_INTERRUPTS(); } -/* - * Release lock previously disowned with LWLockDisown(). - */ -void -LWLockReleaseDisowned(LWLock *lock, LWLockMode mode) -{ - LWLockReleaseInternal(lock, mode); -} - /* * LWLockReleaseClearVar - release a previously acquired lock, reset variable */ -- 2.48.1.76.g4e746b1a31.dirty