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bd272cace6
additional argument specifying the kind of lock to acquire/release (or 'NoLock' to do no lock processing). Ensure that all relations are locked with some appropriate lock level before being examined --- this ensures that relevant shared-inval messages have been processed and should prevent problems caused by concurrent VACUUM. Fix several bugs having to do with mismatched increment/decrement of relation ref count and mismatched heap_open/close (which amounts to the same thing). A bogus ref count on a relation doesn't matter much *unless* a SI Inval message happens to arrive at the wrong time, which is probably why we got away with this sloppiness for so long. Repair missing grab of AccessExclusiveLock in DROP TABLE, ALTER/RENAME TABLE, etc, as noted by Hiroshi. Recommend 'make clean all' after pulling this update; I modified the Relation struct layout slightly. Will post further discussion to pghackers list shortly.
189 lines
4.9 KiB
C
189 lines
4.9 KiB
C
/*-------------------------------------------------------------------------
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*
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* buf_internals.h
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* Internal definitions.
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*
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*
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* Copyright (c) 1994, Regents of the University of California
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*
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* $Id: buf_internals.h,v 1.32 1999/09/18 19:08:18 tgl Exp $
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*
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* NOTE
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* If BUFFERPAGE0 is defined, then 0 will be used as a
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* valid buffer page number.
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*
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*-------------------------------------------------------------------------
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*/
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#ifndef BUFMGR_INTERNALS_H
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#define BUFMGR_INTERNALS_H
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#include "storage/buf.h"
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#include "storage/lmgr.h"
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/* Buf Mgr constants */
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/* in bufmgr.c */
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extern int NBuffers;
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extern int Data_Descriptors;
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extern int Free_List_Descriptor;
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extern int Lookup_List_Descriptor;
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extern int Num_Descriptors;
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/*
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* Flags for buffer descriptors
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*/
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#define BM_DIRTY (1 << 0)
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#define BM_PRIVATE (1 << 1)
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#define BM_VALID (1 << 2)
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#define BM_DELETED (1 << 3)
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#define BM_FREE (1 << 4)
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#define BM_IO_IN_PROGRESS (1 << 5)
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#define BM_IO_ERROR (1 << 6)
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#define BM_JUST_DIRTIED (1 << 7)
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typedef bits16 BufFlags;
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typedef struct sbufdesc BufferDesc;
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typedef struct sbufdesc BufferHdr;
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typedef struct buftag BufferTag;
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/* long * so alignment will be correct */
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typedef long **BufferBlock;
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struct buftag
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{
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LockRelId relId;
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BlockNumber blockNum; /* blknum relative to begin of reln */
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};
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#define CLEAR_BUFFERTAG(a) \
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( \
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(a)->relId.dbId = InvalidOid, \
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(a)->relId.relId = InvalidOid, \
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(a)->blockNum = InvalidBlockNumber \
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)
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#define INIT_BUFFERTAG(a,xx_reln,xx_blockNum) \
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( \
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(a)->blockNum = (xx_blockNum), \
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(a)->relId = (xx_reln)->rd_lockInfo.lockRelId \
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)
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#define BAD_BUFFER_ID(bid) ((bid<1) || (bid>(NBuffers)))
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#define INVALID_DESCRIPTOR (-3)
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/*
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* struct sbufdesc -- shared buffer cache metadata for a single
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* shared buffer descriptor.
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*
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* We keep the name of the database and relation in which this
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* buffer appears in order to avoid a catalog lookup on cache
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* flush if we don't have the reldesc in the cache. It is also
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* possible that the relation to which this buffer belongs is
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* not visible to all backends at the time that it gets flushed.
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* Dbname, relname, dbid, and relid are enough to determine where
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* to put the buffer, for all storage managers.
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*/
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struct sbufdesc
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{
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Buffer freeNext; /* link for freelist chain */
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Buffer freePrev;
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SHMEM_OFFSET data; /* pointer to data in buf pool */
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/* tag and id must be together for table lookup to work */
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BufferTag tag; /* file/block identifier */
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int buf_id; /* maps global desc to local desc */
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BufFlags flags; /* described below */
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unsigned refcount; /* # of times buffer is pinned */
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#ifdef HAS_TEST_AND_SET
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/* can afford a dedicated lock if test-and-set locks are available */
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slock_t io_in_progress_lock;
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slock_t cntx_lock; /* to lock access to page context */
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#endif /* HAS_TEST_AND_SET */
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unsigned r_locks; /* # of shared locks */
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bool ri_lock; /* read-intent lock */
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bool w_lock; /* context exclusively locked */
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char sb_dbname[NAMEDATALEN]; /* name of db in which buf belongs */
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char sb_relname[NAMEDATALEN]; /* name of reln */
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};
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/*
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* Buffer lock infos in BufferLocks below.
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* We have to free these locks in elog(ERROR)...
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*/
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#define BL_IO_IN_PROGRESS (1 << 0) /* unimplemented */
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#define BL_R_LOCK (1 << 1)
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#define BL_RI_LOCK (1 << 2)
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#define BL_W_LOCK (1 << 3)
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/*
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* mao tracing buffer allocation
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*/
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/*#define BMTRACE*/
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#ifdef BMTRACE
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typedef struct _bmtrace
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{
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int bmt_pid;
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long bmt_buf;
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long bmt_dbid;
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long bmt_relid;
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int bmt_blkno;
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int bmt_op;
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#define BMT_NOTUSED 0
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#define BMT_ALLOCFND 1
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#define BMT_ALLOCNOTFND 2
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#define BMT_DEALLOC 3
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} bmtrace;
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#endif /* BMTRACE */
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/*
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* Bufmgr Interface:
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*/
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/* Internal routines: only called by buf.c */
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/*freelist.c*/
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extern void AddBufferToFreelist(BufferDesc *bf);
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extern void PinBuffer(BufferDesc *buf);
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extern void PinBuffer_Debug(char *file, int line, BufferDesc *buf);
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extern void UnpinBuffer(BufferDesc *buf);
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extern BufferDesc *GetFreeBuffer(void);
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extern void InitFreeList(bool init);
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/* buf_table.c */
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extern void InitBufTable(void);
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extern BufferDesc *BufTableLookup(BufferTag *tagPtr);
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extern bool BufTableDelete(BufferDesc *buf);
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extern bool BufTableInsert(BufferDesc *buf);
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/* bufmgr.c */
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extern BufferDesc *BufferDescriptors;
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extern BufferBlock BufferBlocks;
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extern long *PrivateRefCount;
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extern long *LastRefCount;
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extern bits8 *BufferLocks;
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extern long *CommitInfoNeedsSave;
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extern SPINLOCK BufMgrLock;
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/* localbuf.c */
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extern long *LocalRefCount;
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extern BufferDesc *LocalBufferDescriptors;
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extern int NLocBuffer;
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extern BufferDesc *LocalBufferAlloc(Relation reln, BlockNumber blockNum,
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bool *foundPtr);
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extern int WriteLocalBuffer(Buffer buffer, bool release);
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extern int FlushLocalBuffer(Buffer buffer, bool release);
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extern void InitLocalBuffer(void);
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extern void LocalBufferSync(void);
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extern void ResetLocalBufferPool(void);
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#endif /* BUFMGR_INTERNALS_H */
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