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Fix off-by-one bug in LWLockRegisterTranche().

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Original coding failed to enlarge the array as required if
the requested tranche_id was equal to LWLockTranchesAllocated.

In passing, fix poor style of not casting the result of (re)palloc.
This commit is contained in:
Tom Lane 2014-04-25 15:59:57 -04:00
parent 49137ec9d4
commit 4bfc5f1396
1 changed files with 7 additions and 5 deletions
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8
src/backend/storage/lmgr/lwlock.c
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@ -350,7 +350,8 @@ CreateLWLocks(void)
if (LWLockTrancheArray == NULL) if (LWLockTrancheArray == NULL)
{ {
LWLockTranchesAllocated = 16; LWLockTranchesAllocated = 16;
LWLockTrancheArray = MemoryContextAlloc(TopMemoryContext, LWLockTrancheArray = (LWLockTranche **)
MemoryContextAlloc(TopMemoryContext,
LWLockTranchesAllocated * sizeof(LWLockTranche *)); LWLockTranchesAllocated * sizeof(LWLockTranche *));
} }
@ -423,10 +424,11 @@ LWLockRegisterTranche(int tranche_id, LWLockTranche *tranche)
{ {
int i = LWLockTranchesAllocated; int i = LWLockTranchesAllocated;
while (i < tranche_id) while (i <= tranche_id)
i *= 2; i *= 2;
LWLockTrancheArray = repalloc(LWLockTrancheArray, LWLockTrancheArray = (LWLockTranche **)
repalloc(LWLockTrancheArray,
i * sizeof(LWLockTranche *)); i * sizeof(LWLockTranche *));
LWLockTranchesAllocated = i; LWLockTranchesAllocated = i;
} }