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Remove belt-and-suspenders guards against buffer pin leaks.

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Forcibly releasing all leftover buffer pins should be unnecessary now
that we have a robust ResourceOwner mechanism, and it significantly
increases the cost of process shutdown.  Instead, in an assert-enabled
build, assert that no pins are held; in a non-assert-enabled build, do
nothing.
This commit is contained in:
Robert Haas 2010-11-25 00:06:46 -05:00
parent 58dfb07b5d
commit c2281ac87c
2 changed files with 23 additions and 19 deletions
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21
src/backend/storage/buffer/bufmgr.c
View File

@ -1659,31 +1659,26 @@ InitBufferPoolBackend(void)
}
/*
* Ensure we have released all shared-buffer locks and pins during backend exit
* During backend exit, ensure that we released all shared-buffer locks and
* assert that we have no remaining pins.
*/
static void
AtProcExit_Buffers(int code, Datum arg)
{
int i;
AbortBufferIO();
UnlockBuffers();
for (i = 0; i < NBuffers; i++)
#ifdef USE_ASSERT_CHECKING
if (assert_enabled)
{
if (PrivateRefCount[i] != 0)
{
volatile BufferDesc *buf = &(BufferDescriptors[i]);
int i;
/*
* We don't worry about updating ResourceOwner; if we even got
* here, it suggests that ResourceOwners are messed up.
*/
PrivateRefCount[i] = 1; /* make sure we release shared pin */
UnpinBuffer(buf, false);
for (i = 0; i < NBuffers; i++)
{
Assert(PrivateRefCount[i] == 0);
}
}
#endif
/* localbuf.c needs a chance too */
AtProcExit_LocalBuffers();

21
src/backend/storage/buffer/localbuf.c
View File

@ -468,14 +468,23 @@ AtEOXact_LocalBuffers(bool isCommit)
/*
* AtProcExit_LocalBuffers - ensure we have dropped pins during backend exit.
*
* This is just like AtProcExit_Buffers, but for local buffers. We have
* to drop pins to ensure that any attempt to drop temp files doesn't
* fail in DropRelFileNodeBuffers.
* This is just like AtProcExit_Buffers, but for local buffers. We shouldn't
* be holding any remaining pins; if we are, and assertions aren't enabled,
* we'll fail later in DropRelFileNodeBuffers while trying to drop the temp
* rels.
*/
void
AtProcExit_LocalBuffers(void)
{
/* just zero the refcounts ... */
if (LocalRefCount)
MemSet(LocalRefCount, 0, NLocBuffer * sizeof(*LocalRefCount));
#ifdef USE_ASSERT_CHECKING
if (assert_enabled && LocalRefCount)
{
int i;
for (i = 0; i < NLocBuffer; i++)
{
Assert(LocalRefCount[i] == 0);
}
}
#endif
}