diff options
| author | Tom Lane <tgl@sss.pgh.pa.us> | 2005-04-08 14:18:35 +0000 |
|---|---|---|
| committer | Tom Lane <tgl@sss.pgh.pa.us> | 2005-04-08 14:18:35 +0000 |
| commit | badb83f9ec72687c27e8f983fbaefc26a8d1af31 (patch) | |
| tree | cf4b2bcdd16146c0fce2e7f25a1612a4cc2ac2d4 | |
| parent | e794dfa51144574dfbf51716c22116d03c7da7ca (diff) | |
| download | postgresql-badb83f9ec72687c27e8f983fbaefc26a8d1af31.tar.gz postgresql-badb83f9ec72687c27e8f983fbaefc26a8d1af31.zip | |
If we're going to have a non-panic check for held_lwlocks[] overrun,
it must occur *before* we get into the critical state of holding a
lock we have no place to record. Per discussion with Qingqing Zhou.
| -rw-r--r-- | src/backend/storage/lmgr/lwlock.c | 14 |
1 files changed, 9 insertions, 5 deletions
diff --git a/src/backend/storage/lmgr/lwlock.c b/src/backend/storage/lmgr/lwlock.c index 112690ae903..f75ccc869ff 100644 --- a/src/backend/storage/lmgr/lwlock.c +++ b/src/backend/storage/lmgr/lwlock.c @@ -15,7 +15,7 @@ * Portions Copyright (c) 1994, Regents of the University of California * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/storage/lmgr/lwlock.c,v 1.26 2005/04/08 03:43:54 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/storage/lmgr/lwlock.c,v 1.27 2005/04/08 14:18:35 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -213,6 +213,10 @@ LWLockAcquire(LWLockId lockid, LWLockMode mode) */ Assert(!(proc == NULL && IsUnderPostmaster)); + /* Ensure we will have room to remember the lock */ + if (num_held_lwlocks >= MAX_SIMUL_LWLOCKS) + elog(ERROR, "too many LWLocks taken"); + /* * Lock out cancel/die interrupts until we exit the code section * protected by the LWLock. This ensures that interrupts will not @@ -328,8 +332,6 @@ LWLockAcquire(LWLockId lockid, LWLockMode mode) SpinLockRelease_NoHoldoff(&lock->mutex); /* Add lock to list of locks held by this backend */ - if (num_held_lwlocks >= MAX_SIMUL_LWLOCKS) - elog(ERROR, "too many LWLocks taken"); held_lwlocks[num_held_lwlocks++] = lockid; /* @@ -354,6 +356,10 @@ LWLockConditionalAcquire(LWLockId lockid, LWLockMode mode) PRINT_LWDEBUG("LWLockConditionalAcquire", lockid, lock); + /* Ensure we will have room to remember the lock */ + if (num_held_lwlocks >= MAX_SIMUL_LWLOCKS) + elog(ERROR, "too many LWLocks taken"); + /* * Lock out cancel/die interrupts until we exit the code section * protected by the LWLock. This ensures that interrupts will not @@ -398,8 +404,6 @@ LWLockConditionalAcquire(LWLockId lockid, LWLockMode mode) else { /* Add lock to list of locks held by this backend */ - if (num_held_lwlocks >= MAX_SIMUL_LWLOCKS) - elog(ERROR, "too many LWLocks taken"); held_lwlocks[num_held_lwlocks++] = lockid; } |