diff options
| -rw-r--r-- | contrib/pg_buffercache/pg_buffercache_pages.c | 27 | ||||
| -rw-r--r-- | src/backend/storage/buffer/bufmgr.c | 89 | ||||
| -rw-r--r-- | src/backend/storage/buffer/freelist.c | 8 | ||||
| -rw-r--r-- | src/include/storage/buf_internals.h | 11 |
4 files changed, 64 insertions, 71 deletions
diff --git a/contrib/pg_buffercache/pg_buffercache_pages.c b/contrib/pg_buffercache/pg_buffercache_pages.c index e55aff991dc..e511c0df9ad 100644 --- a/contrib/pg_buffercache/pg_buffercache_pages.c +++ b/contrib/pg_buffercache/pg_buffercache_pages.c @@ -3,7 +3,7 @@ * pg_buffercache_pages.c * display some contents of the buffer cache * - * $PostgreSQL: pgsql/contrib/pg_buffercache/pg_buffercache_pages.c,v 1.4 2005/05/31 00:07:47 tgl Exp $ + * $PostgreSQL: pgsql/contrib/pg_buffercache/pg_buffercache_pages.c,v 1.5 2005/10/12 16:45:13 tgl Exp $ *------------------------------------------------------------------------- */ #include "postgres.h" @@ -72,10 +72,8 @@ pg_buffercache_pages(PG_FUNCTION_ARGS) if (SRF_IS_FIRSTCALL()) { - RelFileNode rnode; uint32 i; - BufferDesc *bufHdr; - + volatile BufferDesc *bufHdr; funcctx = SRF_FIRSTCALL_INIT(); @@ -136,35 +134,24 @@ pg_buffercache_pages(PG_FUNCTION_ARGS) /* Lock each buffer header before inspecting. */ LockBufHdr(bufHdr); - rnode = bufHdr->tag.rnode; - fctx->record[i].bufferid = BufferDescriptorGetBuffer(bufHdr); - fctx->record[i].relfilenode = rnode.relNode; - fctx->record[i].reltablespace = rnode.spcNode; - fctx->record[i].reldatabase = rnode.dbNode; + fctx->record[i].relfilenode = bufHdr->tag.rnode.relNode; + fctx->record[i].reltablespace = bufHdr->tag.rnode.spcNode; + fctx->record[i].reldatabase = bufHdr->tag.rnode.dbNode; fctx->record[i].blocknum = bufHdr->tag.blockNum; - if ( bufHdr->flags & BM_DIRTY) - { + if (bufHdr->flags & BM_DIRTY) fctx->record[i].isdirty = true; - } else - { fctx->record[i].isdirty = false; - } /* Note if the buffer is valid, and has storage created */ - if ( (bufHdr->flags & BM_VALID) && (bufHdr->flags & BM_TAG_VALID)) - { + if ((bufHdr->flags & BM_VALID) && (bufHdr->flags & BM_TAG_VALID)) fctx->record[i].isvalid = true; - } else - { fctx->record[i].isvalid = false; - } UnlockBufHdr(bufHdr); - } /* Release Buffer map. */ diff --git a/src/backend/storage/buffer/bufmgr.c b/src/backend/storage/buffer/bufmgr.c index 51b3f56c810..fb3efcbca96 100644 --- a/src/backend/storage/buffer/bufmgr.c +++ b/src/backend/storage/buffer/bufmgr.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/storage/buffer/bufmgr.c,v 1.195 2005/08/12 23:13:54 momjian Exp $ + * $PostgreSQL: pgsql/src/backend/storage/buffer/bufmgr.c,v 1.196 2005/10/12 16:45:13 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -76,24 +76,24 @@ long NDirectFileWrite; /* e.g., I/O in psort and hashjoin. */ /* local state for StartBufferIO and related functions */ -static BufferDesc *InProgressBuf = NULL; +static volatile BufferDesc *InProgressBuf = NULL; static bool IsForInput; /* local state for LockBufferForCleanup */ -static BufferDesc *PinCountWaitBuf = NULL; +static volatile BufferDesc *PinCountWaitBuf = NULL; -static bool PinBuffer(BufferDesc *buf); -static void PinBuffer_Locked(BufferDesc *buf); -static void UnpinBuffer(BufferDesc *buf, bool fixOwner, bool trashOK); +static bool PinBuffer(volatile BufferDesc *buf); +static void PinBuffer_Locked(volatile BufferDesc *buf); +static void UnpinBuffer(volatile BufferDesc *buf, bool fixOwner, bool trashOK); static bool SyncOneBuffer(int buf_id, bool skip_pinned); -static void WaitIO(BufferDesc *buf); -static bool StartBufferIO(BufferDesc *buf, bool forInput); -static void TerminateBufferIO(BufferDesc *buf, bool clear_dirty, +static void WaitIO(volatile BufferDesc *buf); +static bool StartBufferIO(volatile BufferDesc *buf, bool forInput); +static void TerminateBufferIO(volatile BufferDesc *buf, bool clear_dirty, int set_flag_bits); static void buffer_write_error_callback(void *arg); -static BufferDesc *BufferAlloc(Relation reln, BlockNumber blockNum, +static volatile BufferDesc *BufferAlloc(Relation reln, BlockNumber blockNum, bool *foundPtr); -static void FlushBuffer(BufferDesc *buf, SMgrRelation reln); +static void FlushBuffer(volatile BufferDesc *buf, SMgrRelation reln); static void AtProcExit_Buffers(int code, Datum arg); static void write_buffer(Buffer buffer, bool unpin); @@ -116,7 +116,7 @@ static void write_buffer(Buffer buffer, bool unpin); Buffer ReadBuffer(Relation reln, BlockNumber blockNum) { - BufferDesc *bufHdr; + volatile BufferDesc *bufHdr; Block bufBlock; bool found; bool isExtend; @@ -255,7 +255,7 @@ ReadBuffer(Relation reln, BlockNumber blockNum) * * No locks are held either at entry or exit. */ -static BufferDesc * +static volatile BufferDesc * BufferAlloc(Relation reln, BlockNumber blockNum, bool *foundPtr) @@ -264,7 +264,7 @@ BufferAlloc(Relation reln, BufferTag oldTag; BufFlags oldFlags; int buf_id; - BufferDesc *buf; + volatile BufferDesc *buf; bool valid; /* create a tag so we can lookup the buffer */ @@ -512,7 +512,7 @@ BufferAlloc(Relation reln, * to acquire the necessary locks; if so, don't mess it up. */ static void -InvalidateBuffer(BufferDesc *buf) +InvalidateBuffer(volatile BufferDesc *buf) { BufferTag oldTag; BufFlags oldFlags; @@ -602,7 +602,7 @@ retry: static void write_buffer(Buffer buffer, bool unpin) { - BufferDesc *bufHdr; + volatile BufferDesc *bufHdr; if (!BufferIsValid(buffer)) elog(ERROR, "bad buffer id: %d", buffer); @@ -679,7 +679,7 @@ ReleaseAndReadBuffer(Buffer buffer, Relation relation, BlockNumber blockNum) { - BufferDesc *bufHdr; + volatile BufferDesc *bufHdr; if (BufferIsValid(buffer)) { @@ -722,7 +722,7 @@ ReleaseAndReadBuffer(Buffer buffer, * some callers to avoid an extra spinlock cycle. */ static bool -PinBuffer(BufferDesc *buf) +PinBuffer(volatile BufferDesc *buf) { int b = buf->buf_id; bool result; @@ -760,7 +760,7 @@ PinBuffer(BufferDesc *buf) * its state can change under us. */ static void -PinBuffer_Locked(BufferDesc *buf) +PinBuffer_Locked(volatile BufferDesc *buf) { int b = buf->buf_id; @@ -787,7 +787,7 @@ PinBuffer_Locked(BufferDesc *buf) * used recently, and trashOK is true, send the buffer to the freelist. */ static void -UnpinBuffer(BufferDesc *buf, bool fixOwner, bool trashOK) +UnpinBuffer(volatile BufferDesc *buf, bool fixOwner, bool trashOK) { int b = buf->buf_id; @@ -967,7 +967,7 @@ BgBufferSync(void) static bool SyncOneBuffer(int buf_id, bool skip_pinned) { - BufferDesc *bufHdr = &BufferDescriptors[buf_id]; + volatile BufferDesc *bufHdr = &BufferDescriptors[buf_id]; /* * Check whether buffer needs writing. @@ -1114,7 +1114,7 @@ AtProcExit_Buffers(int code, Datum arg) { if (PrivateRefCount[i] != 0) { - BufferDesc *buf = &(BufferDescriptors[i]); + volatile BufferDesc *buf = &(BufferDescriptors[i]); /* * We don't worry about updating ResourceOwner; if we even got @@ -1136,7 +1136,7 @@ AtProcExit_Buffers(int code, Datum arg) void PrintBufferLeakWarning(Buffer buffer) { - BufferDesc *buf; + volatile BufferDesc *buf; int32 loccount; Assert(BufferIsValid(buffer)); @@ -1199,7 +1199,7 @@ BufmgrCommit(void) BlockNumber BufferGetBlockNumber(Buffer buffer) { - BufferDesc *bufHdr; + volatile BufferDesc *bufHdr; Assert(BufferIsPinned(buffer)); @@ -1222,7 +1222,7 @@ BufferGetBlockNumber(Buffer buffer) RelFileNode BufferGetFileNode(Buffer buffer) { - BufferDesc *bufHdr; + volatile BufferDesc *bufHdr; if (BufferIsLocal(buffer)) bufHdr = &(LocalBufferDescriptors[-buffer - 1]); @@ -1252,7 +1252,7 @@ BufferGetFileNode(Buffer buffer) * as the second parameter. If not, pass NULL. */ static void -FlushBuffer(BufferDesc *buf, SMgrRelation reln) +FlushBuffer(volatile BufferDesc *buf, SMgrRelation reln) { XLogRecPtr recptr; ErrorContextCallback errcontext; @@ -1267,7 +1267,7 @@ FlushBuffer(BufferDesc *buf, SMgrRelation reln) /* Setup error traceback support for ereport() */ errcontext.callback = buffer_write_error_callback; - errcontext.arg = buf; + errcontext.arg = (void *) buf; errcontext.previous = error_context_stack; error_context_stack = &errcontext; @@ -1375,7 +1375,7 @@ DropRelFileNodeBuffers(RelFileNode rnode, bool istemp, BlockNumber firstDelBlock) { int i; - BufferDesc *bufHdr; + volatile BufferDesc *bufHdr; if (istemp) { @@ -1427,7 +1427,7 @@ void DropBuffers(Oid dbid) { int i; - BufferDesc *bufHdr; + volatile BufferDesc *bufHdr; /* * We needn't consider local buffers, since by assumption the target @@ -1457,7 +1457,7 @@ void PrintBufferDescs(void) { int i; - BufferDesc *buf = BufferDescriptors; + volatile BufferDesc *buf = BufferDescriptors; for (i = 0; i < NBuffers; ++i, ++buf) { @@ -1479,7 +1479,7 @@ void PrintPinnedBufs(void) { int i; - BufferDesc *buf = BufferDescriptors; + volatile BufferDesc *buf = BufferDescriptors; for (i = 0; i < NBuffers; ++i, ++buf) { @@ -1522,7 +1522,7 @@ void FlushRelationBuffers(Relation rel) { int i; - BufferDesc *bufHdr; + volatile BufferDesc *bufHdr; /* Open rel at the smgr level if not already done */ RelationOpenSmgr(rel); @@ -1539,7 +1539,7 @@ FlushRelationBuffers(Relation rel) /* Setup error traceback support for ereport() */ errcontext.callback = buffer_write_error_callback; - errcontext.arg = bufHdr; + errcontext.arg = (void *) bufHdr; errcontext.previous = error_context_stack; error_context_stack = &errcontext; @@ -1586,7 +1586,7 @@ FlushRelationBuffers(Relation rel) void ReleaseBuffer(Buffer buffer) { - BufferDesc *bufHdr; + volatile BufferDesc *bufHdr; if (!BufferIsValid(buffer)) elog(ERROR, "bad buffer id: %d", buffer); @@ -1657,7 +1657,7 @@ IncrBufferRefCount(Buffer buffer) void SetBufferCommitInfoNeedsSave(Buffer buffer) { - BufferDesc *bufHdr; + volatile BufferDesc *bufHdr; if (!BufferIsValid(buffer)) elog(ERROR, "bad buffer id: %d", buffer); @@ -1694,7 +1694,7 @@ SetBufferCommitInfoNeedsSave(Buffer buffer) void UnlockBuffers(void) { - BufferDesc *buf = PinCountWaitBuf; + volatile BufferDesc *buf = PinCountWaitBuf; if (buf) { @@ -1727,7 +1727,7 @@ UnlockBuffers(void) void LockBuffer(Buffer buffer, int mode) { - BufferDesc *buf; + volatile BufferDesc *buf; Assert(BufferIsValid(buffer)); if (BufferIsLocal(buffer)) @@ -1765,7 +1765,7 @@ LockBuffer(Buffer buffer, int mode) bool ConditionalLockBuffer(Buffer buffer) { - BufferDesc *buf; + volatile BufferDesc *buf; Assert(BufferIsValid(buffer)); if (BufferIsLocal(buffer)) @@ -1809,7 +1809,7 @@ ConditionalLockBuffer(Buffer buffer) void LockBufferForCleanup(Buffer buffer) { - BufferDesc *bufHdr; + volatile BufferDesc *bufHdr; Assert(BufferIsValid(buffer)); Assert(PinCountWaitBuf == NULL); @@ -1875,7 +1875,7 @@ LockBufferForCleanup(Buffer buffer) * WaitIO -- Block until the IO_IN_PROGRESS flag on 'buf' is cleared. */ static void -WaitIO(BufferDesc *buf) +WaitIO(volatile BufferDesc *buf) { /* * Changed to wait until there's no IO - Inoue 01/13/2000 @@ -1922,7 +1922,7 @@ WaitIO(BufferDesc *buf) * FALSE if someone else already did the work. */ static bool -StartBufferIO(BufferDesc *buf, bool forInput) +StartBufferIO(volatile BufferDesc *buf, bool forInput) { Assert(!InProgressBuf); @@ -1989,7 +1989,8 @@ StartBufferIO(BufferDesc *buf, bool forInput) * be 0, or BM_VALID if we just finished reading in the page. */ static void -TerminateBufferIO(BufferDesc *buf, bool clear_dirty, int set_flag_bits) +TerminateBufferIO(volatile BufferDesc *buf, bool clear_dirty, + int set_flag_bits) { Assert(buf == InProgressBuf); @@ -2021,7 +2022,7 @@ TerminateBufferIO(BufferDesc *buf, bool clear_dirty, int set_flag_bits) void AbortBufferIO(void) { - BufferDesc *buf = InProgressBuf; + volatile BufferDesc *buf = InProgressBuf; if (buf) { @@ -2075,7 +2076,7 @@ AbortBufferIO(void) static void buffer_write_error_callback(void *arg) { - BufferDesc *bufHdr = (BufferDesc *) arg; + volatile BufferDesc *bufHdr = (volatile BufferDesc *) arg; /* Buffer is pinned, so we can read the tag without locking the spinlock */ if (bufHdr != NULL) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 906165638b6..4739512ad36 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -9,7 +9,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/storage/buffer/freelist.c,v 1.52 2005/08/20 23:26:17 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/storage/buffer/freelist.c,v 1.53 2005/10/12 16:45:13 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -55,10 +55,10 @@ bool strategy_hint_vacuum = false; * means that we return with the BufFreelistLock still held, as well; * the caller must release that lock once the spinlock is dropped. */ -BufferDesc * +volatile BufferDesc * StrategyGetBuffer(void) { - BufferDesc *buf; + volatile BufferDesc *buf; int trycounter; LWLockAcquire(BufFreelistLock, LW_EXCLUSIVE); @@ -138,7 +138,7 @@ StrategyGetBuffer(void) * quickly the buffer is reused. */ void -StrategyFreeBuffer(BufferDesc *buf, bool at_head) +StrategyFreeBuffer(volatile BufferDesc *buf, bool at_head) { LWLockAcquire(BufFreelistLock, LW_EXCLUSIVE); diff --git a/src/include/storage/buf_internals.h b/src/include/storage/buf_internals.h index 6e083be21ba..e75f24a6ced 100644 --- a/src/include/storage/buf_internals.h +++ b/src/include/storage/buf_internals.h @@ -8,7 +8,7 @@ * Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group * Portions Copyright (c) 1994, Regents of the University of California * - * $PostgreSQL: pgsql/src/include/storage/buf_internals.h,v 1.79 2005/08/20 23:26:33 tgl Exp $ + * $PostgreSQL: pgsql/src/include/storage/buf_internals.h,v 1.80 2005/10/12 16:45:14 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -145,6 +145,11 @@ typedef struct sbufdesc * NoHoldoff cases may be used when we know that we hold some LWLock * and therefore interrupts are already held off. Do not apply these * to local buffers! + * + * Note: as a general coding rule, if you are using these then you probably + * want to be using a volatile-qualified pointer to the buffer header, to + * ensure that the compiler doesn't rearrange accesses to the header to + * occur before or after the spinlock is acquired/released. */ #define LockBufHdr(bufHdr) \ SpinLockAcquire(&(bufHdr)->buf_hdr_lock) @@ -179,8 +184,8 @@ extern long int LocalBufferFlushCount; */ /* freelist.c */ -extern BufferDesc *StrategyGetBuffer(void); -extern void StrategyFreeBuffer(BufferDesc *buf, bool at_head); +extern volatile BufferDesc *StrategyGetBuffer(void); +extern void StrategyFreeBuffer(volatile BufferDesc *buf, bool at_head); extern int StrategySyncStart(void); extern Size StrategyShmemSize(void); extern void StrategyInitialize(bool init); |