diff options
Diffstat (limited to 'src/backend/storage/buffer/bufmgr.c')
| -rw-r--r-- | src/backend/storage/buffer/bufmgr.c | 177 |
1 files changed, 97 insertions, 80 deletions
diff --git a/src/backend/storage/buffer/bufmgr.c b/src/backend/storage/buffer/bufmgr.c index b435dd53cac..e0327c678f2 100644 --- a/src/backend/storage/buffer/bufmgr.c +++ b/src/backend/storage/buffer/bufmgr.c @@ -7,7 +7,7 @@ * * * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/backend/storage/buffer/bufmgr.c,v 1.62 1999/09/18 19:07:26 tgl Exp $ + * $Header: /cvsroot/pgsql/src/backend/storage/buffer/bufmgr.c,v 1.63 1999/09/24 00:24:29 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -89,9 +89,6 @@ static void BufferSync(void); static int BufferReplace(BufferDesc *bufHdr, bool bufferLockHeld); void PrintBufferDescs(void); -/* not static but used by vacuum only ... */ -int BlowawayRelationBuffers(Relation rel, BlockNumber block); - /* --------------------------------------------------- * RelationGetBufferWithBuffer * see if the given buffer is what we want @@ -146,9 +143,6 @@ RelationGetBufferWithBuffer(Relation relation, * opened already. */ -extern int ShowPinTrace; - - #undef ReadBuffer /* conflicts with macro when BUFMGR_DEBUG * defined */ @@ -499,6 +493,7 @@ BufferAlloc(Relation reln, SignalIO(buf); #endif /* !HAS_TEST_AND_SET */ PrivateRefCount[BufferDescriptorGetBuffer(buf) - 1] = 0; + Assert(buf->refcount > 0); buf->refcount--; if (buf->refcount == 0) { @@ -575,10 +570,14 @@ BufferAlloc(Relation reln, SignalIO(buf); #endif /* !HAS_TEST_AND_SET */ /* give up the buffer since we don't need it any more */ - buf->refcount--; PrivateRefCount[BufferDescriptorGetBuffer(buf) - 1] = 0; - AddBufferToFreelist(buf); - buf->flags |= BM_FREE; + Assert(buf->refcount > 0); + buf->refcount--; + if (buf->refcount == 0) + { + AddBufferToFreelist(buf); + buf->flags |= BM_FREE; + } buf->flags &= ~BM_IO_IN_PROGRESS; } @@ -791,7 +790,7 @@ FlushBuffer(Buffer buffer, bool release) int status; if (BufferIsLocal(buffer)) - return FlushLocalBuffer(buffer, release); + return FlushLocalBuffer(buffer, release) ? STATUS_OK : STATUS_ERROR; if (BAD_BUFFER_ID(buffer)) return STATUS_ERROR; @@ -813,7 +812,7 @@ FlushBuffer(Buffer buffer, bool release) status = smgrflush(DEFAULT_SMGR, bufrel, bufHdr->tag.blockNum, (char *) MAKE_PTR(bufHdr->data)); - /* drop relcache refcount incremented by RelationIdCacheGetRelation */ + /* drop relcache refcnt incremented by RelationIdCacheGetRelation */ RelationDecrementReferenceCount(bufrel); if (status == SM_FAIL) @@ -908,15 +907,10 @@ ReleaseAndReadBuffer(Buffer buffer, bufHdr = &BufferDescriptors[buffer - 1]; Assert(PrivateRefCount[buffer - 1] > 0); PrivateRefCount[buffer - 1]--; - if (PrivateRefCount[buffer - 1] == 0 && - LastRefCount[buffer - 1] == 0) + if (PrivateRefCount[buffer - 1] == 0) { - - /* - * only release buffer if it is not pinned in previous - * ExecMain level - */ SpinAcquire(BufMgrLock); + Assert(bufHdr->refcount > 0); bufHdr->refcount--; if (bufHdr->refcount == 0) { @@ -994,7 +988,7 @@ BufferSync() elog(ERROR, "BufferSync: write error %u for %s", bufHdr->tag.blockNum, bufHdr->sb_relname); } - /* drop refcount from RelationIdCacheGetRelation */ + /* drop refcnt from RelationIdCacheGetRelation */ if (reln != (Relation) NULL) RelationDecrementReferenceCount(reln); continue; @@ -1049,7 +1043,7 @@ BufferSync() */ if (!(bufHdr->flags & BM_JUST_DIRTIED)) bufHdr->flags &= ~BM_DIRTY; - /* drop refcount from RelationIdCacheGetRelation */ + /* drop refcnt from RelationIdCacheGetRelation */ if (reln != (Relation) NULL) RelationDecrementReferenceCount(reln); } @@ -1175,7 +1169,7 @@ ResetBufferUsage() * ResetBufferPool * * this routine is supposed to be called when a transaction aborts. - * it will release all the buffer pins held by the transaciton. + * it will release all the buffer pins held by the transaction. * * ---------------------------------------------- */ @@ -1184,15 +1178,24 @@ ResetBufferPool() { int i; - for (i = 1; i <= NBuffers; i++) + for (i = 0; i < NBuffers; i++) { - CommitInfoNeedsSave[i - 1] = 0; - if (BufferIsValid(i)) + if (PrivateRefCount[i] != 0) { - while (PrivateRefCount[i - 1] > 0) - ReleaseBuffer(i); + BufferDesc *buf = &BufferDescriptors[i]; + + SpinAcquire(BufMgrLock); + Assert(buf->refcount > 0); + buf->refcount--; + if (buf->refcount == 0) + { + AddBufferToFreelist(buf); + buf->flags |= BM_FREE; + } + SpinRelease(BufMgrLock); } - LastRefCount[i - 1] = 0; + PrivateRefCount[i] = 0; + CommitInfoNeedsSave[i] = 0; } ResetLocalBufferPool(); @@ -1213,7 +1216,7 @@ BufferPoolCheckLeak() for (i = 1; i <= NBuffers; i++) { - if (BufferIsValid(i)) + if (PrivateRefCount[i - 1] != 0) { BufferDesc *buf = &(BufferDescriptors[i - 1]); @@ -1226,7 +1229,7 @@ relname=%s, blockNum=%d, flags=0x%x, refcount=%d %d)", result = 1; } } - return (result); + return result; } /* ------------------------------------------------ @@ -1287,7 +1290,7 @@ BufferGetRelation(Buffer buffer) relation = RelationIdGetRelation(relid); Assert(relation); - /* drop relcache refcount incremented by RelationIdGetRelation */ + /* drop relcache refcnt incremented by RelationIdGetRelation */ RelationDecrementReferenceCount(relation); if (RelationHasReferenceCountZero(relation)) @@ -1354,7 +1357,7 @@ BufferReplace(BufferDesc *bufHdr, bool bufferLockHeld) (char *) MAKE_PTR(bufHdr->data)); } - /* drop relcache refcount incremented by RelationIdCacheGetRelation */ + /* drop relcache refcnt incremented by RelationIdCacheGetRelation */ if (reln != (Relation) NULL) RelationDecrementReferenceCount(reln); @@ -1549,10 +1552,27 @@ BufferPoolBlowaway() #endif /* --------------------------------------------------------------------- - * BlowawayRelationBuffers + * FlushRelationBuffers + * + * This function removes from the buffer pool all pages of a relation + * that have blocknumber >= specified block. If doFlush is true, + * dirty buffers are written out --- otherwise it's an error for any + * of the buffers to be dirty. + * + * This is used by VACUUM before truncating the relation to the given + * number of blocks. For VACUUM, we pass doFlush = false since it would + * mean a bug in VACUUM if any of the unwanted pages were still dirty. + * (TRUNCATE TABLE also uses it in the same way.) * - * This function blowaway all the pages with blocknumber >= passed - * of a relation in the buffer pool. Used by vacuum before truncation... + * This is also used by RENAME TABLE (with block = 0 and doFlush = true) + * to clear out the buffer cache before renaming the physical files of + * a relation. Without that, some other backend might try to do a + * blind write of a buffer page (relying on the sb_relname of the buffer) + * and fail because it's not got the right filename anymore. + * + * In both cases, the caller should be holding AccessExclusiveLock on + * the target relation to ensure that no other backend is busy reading + * more blocks of the relation... * * Returns: 0 - Ok, -1 - DIRTY, -2 - PINNED * @@ -1561,7 +1581,7 @@ BufferPoolBlowaway() * -------------------------------------------------------------------- */ int -BlowawayRelationBuffers(Relation rel, BlockNumber block) +FlushRelationBuffers(Relation rel, BlockNumber block, bool doFlush) { int i; BufferDesc *buf; @@ -1576,13 +1596,25 @@ BlowawayRelationBuffers(Relation rel, BlockNumber block) { if (buf->flags & BM_DIRTY) { - elog(NOTICE, "BlowawayRelationBuffers(%s (local), %u): block %u is dirty", - rel->rd_rel->relname.data, block, buf->tag.blockNum); - return -1; + if (doFlush) + { + if (FlushBuffer(-i-1, false) != STATUS_OK) + { + elog(NOTICE, "FlushRelationBuffers(%s (local), %u): block %u is dirty, could not flush it", + rel->rd_rel->relname.data, block, buf->tag.blockNum); + return -1; + } + } + else + { + elog(NOTICE, "FlushRelationBuffers(%s (local), %u): block %u is dirty", + rel->rd_rel->relname.data, block, buf->tag.blockNum); + return -1; + } } if (LocalRefCount[i] > 0) { - elog(NOTICE, "BlowawayRelationBuffers(%s (local), %u): block %u is referenced (%d)", + elog(NOTICE, "FlushRelationBuffers(%s (local), %u): block %u is referenced (%d)", rel->rd_rel->relname.data, block, buf->tag.blockNum, LocalRefCount[i]); return -2; @@ -1603,18 +1635,33 @@ BlowawayRelationBuffers(Relation rel, BlockNumber block) { if (buf->flags & BM_DIRTY) { - elog(NOTICE, "BlowawayRelationBuffers(%s, %u): block %u is dirty (private %d, last %d, global %d)", - buf->sb_relname, block, buf->tag.blockNum, - PrivateRefCount[i], LastRefCount[i], buf->refcount); - SpinRelease(BufMgrLock); - return -1; + if (doFlush) + { + SpinRelease(BufMgrLock); + if (FlushBuffer(i+1, false) != STATUS_OK) + { + elog(NOTICE, "FlushRelationBuffers(%s, %u): block %u is dirty (private %d, global %d), could not flush it", + buf->sb_relname, block, buf->tag.blockNum, + PrivateRefCount[i], buf->refcount); + return -1; + } + SpinAcquire(BufMgrLock); + } + else + { + SpinRelease(BufMgrLock); + elog(NOTICE, "FlushRelationBuffers(%s, %u): block %u is dirty (private %d, global %d)", + buf->sb_relname, block, buf->tag.blockNum, + PrivateRefCount[i], buf->refcount); + return -1; + } } if (!(buf->flags & BM_FREE)) { - elog(NOTICE, "BlowawayRelationBuffers(%s, %u): block %u is referenced (private %d, last %d, global %d)", - buf->sb_relname, block, buf->tag.blockNum, - PrivateRefCount[i], LastRefCount[i], buf->refcount); SpinRelease(BufMgrLock); + elog(NOTICE, "FlushRelationBuffers(%s, %u): block %u is referenced (private %d, global %d)", + buf->sb_relname, block, buf->tag.blockNum, + PrivateRefCount[i], buf->refcount); return -2; } BufTableDelete(buf); @@ -1650,14 +1697,10 @@ ReleaseBuffer(Buffer buffer) Assert(PrivateRefCount[buffer - 1] > 0); PrivateRefCount[buffer - 1]--; - if (PrivateRefCount[buffer - 1] == 0 && LastRefCount[buffer - 1] == 0) + if (PrivateRefCount[buffer - 1] == 0) { - - /* - * only release buffer if it is not pinned in previous ExecMain - * levels - */ SpinAcquire(BufMgrLock); + Assert(bufHdr->refcount > 0); bufHdr->refcount--; if (bufHdr->refcount == 0) { @@ -1892,32 +1935,6 @@ _bm_die(Oid dbId, Oid relId, int blkNo, int bufNo, #endif /* BMTRACE */ -void -BufferRefCountReset(int *refcountsave) -{ - int i; - - for (i = 0; i < NBuffers; i++) - { - refcountsave[i] = PrivateRefCount[i]; - LastRefCount[i] += PrivateRefCount[i]; - PrivateRefCount[i] = 0; - } -} - -void -BufferRefCountRestore(int *refcountsave) -{ - int i; - - for (i = 0; i < NBuffers; i++) - { - PrivateRefCount[i] = refcountsave[i]; - LastRefCount[i] -= refcountsave[i]; - refcountsave[i] = 0; - } -} - int SetBufferWriteMode(int mode) { |