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Minor code cleanup in bufmgr.c and bufmgr.h, mainly by moving repeated

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lines of code into internal routines (drop_relfilenode_buffers,
release_buffer) and by hiding unused routines (PrintBufferDescs,
PrintPinnedBufs) behind #ifdef NOT_USED. Remove AbortBufferIO()
declaration from bufmgr.c (already declared in bufmgr.h)

Manfred Koizar
REL7_3_STABLE
Bruce Momjian 24 years ago
parent 97bfffe50e
commit 8864603f3c
2 changed files with 70 additions and 119 deletions
Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL
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  1. 185
      src/backend/storage/buffer/bufmgr.c
  2. 4
      src/include/storage/bufmgr.h

185
src/backend/storage/buffer/bufmgr.c
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@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/storage/buffer/bufmgr.c,v 1.126 2002/06/20 20:29:34 momjian Exp $
* $Header: /cvsroot/pgsql/src/backend/storage/buffer/bufmgr.c,v 1.127 2002/07/02 05:47:37 momjian Exp $
*
*-------------------------------------------------------------------------
*/
@ -71,7 +71,6 @@ static void WaitIO(BufferDesc *buf);
static void StartBufferIO(BufferDesc *buf, bool forInput);
static void TerminateBufferIO(BufferDesc *buf);
static void ContinueBufferIO(BufferDesc *buf, bool forInput);
extern void AbortBufferIO(void);
/*
* Macro : BUFFER_IS_BROKEN
@ -85,9 +84,14 @@ static BufferDesc *BufferAlloc(Relation reln, BlockNumber blockNum,
bool *foundPtr);
static int ReleaseBufferWithBufferLock(Buffer buffer);
static int BufferReplace(BufferDesc *bufHdr);
#ifdef NOT_USED
void PrintBufferDescs(void);
#endif
static void write_buffer(Buffer buffer, bool unpin);
static void drop_relfilenode_buffers(RelFileNode rnode,
bool do_local, bool do_both);
static int release_buffer(Buffer buffer, bool havelock);
/*
* ReadBuffer -- returns a buffer containing the requested
@ -1097,34 +1101,26 @@ RelationGetNumberOfBlocks(Relation relation)
return relation->rd_nblocks;
}
/* ---------------------------------------------------------------------
* DropRelationBuffers
*
* This function removes all the buffered pages for a relation
* from the buffer pool. Dirty pages are simply dropped, without
* bothering to write them out first. This is NOT rollback-able,
* and so should be used only with extreme caution!
*
* We assume that the caller holds an exclusive lock on the relation,
* which should assure that no new buffers will be acquired for the rel
* meanwhile.
/*
* drop_relfilenode_buffers -- common functionality for
* DropRelationBuffers and
* DropRelFileNodeBuffers
*
* XXX currently it sequentially searches the buffer pool, should be
* changed to more clever ways of searching.
* --------------------------------------------------------------------
*/
void
DropRelationBuffers(Relation rel)
static void
drop_relfilenode_buffers(RelFileNode rnode, bool do_local, bool do_both)
{
int i;
BufferDesc *bufHdr;
if (rel->rd_myxactonly)
if (do_local)
{
for (i = 0; i < NLocBuffer; i++)
{
bufHdr = &LocalBufferDescriptors[i];
if (RelFileNodeEquals(bufHdr->tag.rnode, rel->rd_node))
if (RelFileNodeEquals(bufHdr->tag.rnode, rnode))
{
bufHdr->flags &= ~(BM_DIRTY | BM_JUST_DIRTIED);
bufHdr->cntxDirty = false;
@ -1132,7 +1128,8 @@ DropRelationBuffers(Relation rel)
bufHdr->tag.rnode.relNode = InvalidOid;
}
}
return;
if (!do_both)
return;
}
LWLockAcquire(BufMgrLock, LW_EXCLUSIVE);
@ -1141,7 +1138,7 @@ DropRelationBuffers(Relation rel)
{
bufHdr = &BufferDescriptors[i - 1];
recheck:
if (RelFileNodeEquals(bufHdr->tag.rnode, rel->rd_node))
if (RelFileNodeEquals(bufHdr->tag.rnode, rnode))
{
/*
* If there is I/O in progress, better wait till it's done;
@ -1187,6 +1184,25 @@ recheck:
LWLockRelease(BufMgrLock);
}
/* ---------------------------------------------------------------------
* DropRelationBuffers
*
* This function removes all the buffered pages for a relation
* from the buffer pool. Dirty pages are simply dropped, without
* bothering to write them out first. This is NOT rollback-able,
* and so should be used only with extreme caution!
*
* We assume that the caller holds an exclusive lock on the relation,
* which should assure that no new buffers will be acquired for the rel
* meanwhile.
* --------------------------------------------------------------------
*/
void
DropRelationBuffers(Relation rel)
{
drop_relfilenode_buffers(rel->rd_node, rel->rd_myxactonly, false);
}
/* ---------------------------------------------------------------------
* DropRelFileNodeBuffers
*
@ -1201,73 +1217,8 @@ recheck:
void
DropRelFileNodeBuffers(RelFileNode rnode)
{
int i;
BufferDesc *bufHdr;
/* We have to search both local and shared buffers... */
for (i = 0; i < NLocBuffer; i++)
{
bufHdr = &LocalBufferDescriptors[i];
if (RelFileNodeEquals(bufHdr->tag.rnode, rnode))
{
bufHdr->flags &= ~(BM_DIRTY | BM_JUST_DIRTIED);
bufHdr->cntxDirty = false;
LocalRefCount[i] = 0;
bufHdr->tag.rnode.relNode = InvalidOid;
}
}
LWLockAcquire(BufMgrLock, LW_EXCLUSIVE);
for (i = 1; i <= NBuffers; i++)
{
bufHdr = &BufferDescriptors[i - 1];
recheck:
if (RelFileNodeEquals(bufHdr->tag.rnode, rnode))
{
/*
* If there is I/O in progress, better wait till it's done;
* don't want to delete the relation out from under someone
* who's just trying to flush the buffer!
*/
if (bufHdr->flags & BM_IO_IN_PROGRESS)
{
WaitIO(bufHdr);
/*
* By now, the buffer very possibly belongs to some other
* rel, so check again before proceeding.
*/
goto recheck;
}
/* Now we can do what we came for */
bufHdr->flags &= ~(BM_DIRTY | BM_JUST_DIRTIED);
bufHdr->cntxDirty = false;
/*
* Release any refcount we may have.
*
* This is very probably dead code, and if it isn't then it's
* probably wrong. I added the Assert to find out --- tgl
* 11/99.
*/
if (!(bufHdr->flags & BM_FREE))
{
/* Assert checks that buffer will actually get freed! */
Assert(PrivateRefCount[i - 1] == 1 &&
bufHdr->refcount == 1);
ReleaseBufferWithBufferLock(i);
}
/*
* And mark the buffer as no longer occupied by this rel.
*/
BufTableDelete(bufHdr);
}
}
LWLockRelease(BufMgrLock);
drop_relfilenode_buffers(rnode, true, true);
}
/* ---------------------------------------------------------------------
@ -1343,6 +1294,7 @@ recheck:
* use only.
* -----------------------------------------------------------------
*/
#ifdef NOT_USED
void
PrintBufferDescs()
{
@ -1375,7 +1327,9 @@ blockNum=%u, flags=0x%x, refcount=%d %ld)",
}
}
}
#endif
#ifdef NOT_USED
void
PrintPinnedBufs()
{
@ -1395,6 +1349,7 @@ blockNum=%u, flags=0x%x, refcount=%d %ld)",
}
LWLockRelease(BufMgrLock);
}
#endif
/*
* BufferPoolBlowaway
@ -1589,14 +1544,12 @@ FlushRelationBuffers(Relation rel, BlockNumber firstDelBlock)
return 0;
}
#undef ReleaseBuffer
/*
* ReleaseBuffer -- remove the pin on a buffer without
* marking it dirty.
* release_buffer -- common functionality for
* ReleaseBuffer and ReleaseBufferWithBufferLock
*/
int
ReleaseBuffer(Buffer buffer)
static int
release_buffer(Buffer buffer, bool havelock)
{
BufferDesc *bufHdr;
@ -1617,14 +1570,30 @@ ReleaseBuffer(Buffer buffer)
PrivateRefCount[buffer - 1]--;
else
{
LWLockAcquire(BufMgrLock, LW_EXCLUSIVE);
if (!havelock)
LWLockAcquire(BufMgrLock, LW_EXCLUSIVE);
UnpinBuffer(bufHdr);
LWLockRelease(BufMgrLock);
if (!havelock)
LWLockRelease(BufMgrLock);
}
return STATUS_OK;
}
#undef ReleaseBuffer
/*
* ReleaseBuffer -- remove the pin on a buffer without
* marking it dirty.
*/
int
ReleaseBuffer(Buffer buffer)
{
return release_buffer(buffer, false);
}
/*
* ReleaseBufferWithBufferLock
* Same as ReleaseBuffer except we hold the bufmgr lock
@ -1632,27 +1601,7 @@ ReleaseBuffer(Buffer buffer)
static int
ReleaseBufferWithBufferLock(Buffer buffer)
{
BufferDesc *bufHdr;
if (BufferIsLocal(buffer))
{
Assert(LocalRefCount[-buffer - 1] > 0);
LocalRefCount[-buffer - 1]--;
return STATUS_OK;
}
if (BAD_BUFFER_ID(buffer))
return STATUS_ERROR;
bufHdr = &BufferDescriptors[buffer - 1];
Assert(PrivateRefCount[buffer - 1] > 0);
if (PrivateRefCount[buffer - 1] > 1)
PrivateRefCount[buffer - 1]--;
else
UnpinBuffer(bufHdr);
return STATUS_OK;
return release_buffer(buffer, true);
}
@ -1695,7 +1644,7 @@ refcount = %ld, file: %s, line: %d\n",
#endif
#ifdef NOT_USED
int
Buffer
ReleaseAndReadBuffer_Debug(char *file,
int line,
Buffer buffer,
@ -2117,7 +2066,7 @@ TerminateBufferIO(BufferDesc *buf)
{
Assert(buf == InProgressBuf);
LWLockRelease(buf->io_in_progress_lock);
InProgressBuf = (BufferDesc *) 0;
InProgressBuf = (BufferDesc *) NULL;
}
/*
@ -2142,7 +2091,7 @@ ContinueBufferIO(BufferDesc *buf, bool forInput)
void
InitBufferIO(void)
{
InProgressBuf = (BufferDesc *) 0;
InProgressBuf = (BufferDesc *) NULL;
}
#endif

4
src/include/storage/bufmgr.h
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@ -7,7 +7,7 @@
* Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* $Id: bufmgr.h,v 1.60 2002/06/20 20:29:52 momjian Exp $
* $Id: bufmgr.h,v 1.61 2002/07/02 05:47:37 momjian Exp $
*
*-------------------------------------------------------------------------
*/
@ -167,7 +167,9 @@ extern int FlushRelationBuffers(Relation rel, BlockNumber firstDelBlock);
extern void DropRelationBuffers(Relation rel);
extern void DropRelFileNodeBuffers(RelFileNode rnode);
extern void DropBuffers(Oid dbid);
#ifdef NOT_USED
extern void PrintPinnedBufs(void);
#endif
extern int BufferShmemSize(void);
extern RelFileNode BufferGetFileNode(Buffer buffer);

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