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7863404417
Improve 'pg_internal.init' relcache entry preload mechanism so that it is safe to use for all system catalogs, and arrange to preload a realistic set of system-catalog entries instead of only the three nailed-in-cache indexes that were formerly loaded this way. Fix mechanism for deleting out-of-date pg_internal.init files: this must be synchronized with transaction commit, not just done at random times within transactions. Drive it off relcache invalidation mechanism so that no special-case tests are needed. Cache additional information in relcache entries for indexes (their pg_index tuples and index-operator OIDs) to eliminate repeated lookups. Also cache index opclass info at the per-opclass level to avoid repeated lookups during relcache load. Generalize 'systable scan' utilities originally developed by Hiroshi, move them into genam.c, use in a number of places where there was formerly ugly code for choosing either heap or index scan. In particular this allows simplification of the logic that prevents infinite recursion between syscache and relcache during startup: we can easily switch to heapscans in relcache.c when and where needed to avoid recursion, so IndexScanOK becomes simpler and does not need any expensive initialization. Eliminate useless opening of a heapscan data structure while doing an indexscan (this saves an mdnblocks call and thus at least one kernel call).
72 lines
1.8 KiB
C
72 lines
1.8 KiB
C
/*-------------------------------------------------------------------------
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*
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* lwlock.h
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* Lightweight lock manager
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*
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*
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* Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group
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* Portions Copyright (c) 1994, Regents of the University of California
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*
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* $Id: lwlock.h,v 1.5 2002/02/19 20:11:19 tgl Exp $
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*
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*-------------------------------------------------------------------------
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*/
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#ifndef LWLOCK_H
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#define LWLOCK_H
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/*
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* We have a number of predefined LWLocks, plus a bunch of LWLocks that are
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* dynamically assigned (for shared buffers). The LWLock structures live
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* in shared memory (since they contain shared data) and are identified by
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* values of this enumerated type. We abuse the notion of an enum somewhat
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* by allowing values not listed in the enum declaration to be assigned.
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* The extra value MaxDynamicLWLock is there to keep the compiler from
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* deciding that the enum can be represented as char or short ...
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*/
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typedef enum LWLockId
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{
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BufMgrLock,
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LockMgrLock,
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OidGenLock,
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XidGenLock,
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ShmemIndexLock,
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SInvalLock,
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FreeSpaceLock,
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MMCacheLock,
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WALInsertLock,
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WALWriteLock,
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ControlFileLock,
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CheckpointLock,
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CLogControlLock,
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RelCacheInitLock,
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NumFixedLWLocks, /* must be last except for
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* MaxDynamicLWLock */
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MaxDynamicLWLock = 1000000000
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} LWLockId;
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typedef enum LWLockMode
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{
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LW_EXCLUSIVE,
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LW_SHARED
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} LWLockMode;
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#ifdef LOCK_DEBUG
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extern bool Trace_lwlocks;
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#endif
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extern LWLockId LWLockAssign(void);
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extern void LWLockAcquire(LWLockId lockid, LWLockMode mode);
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extern bool LWLockConditionalAcquire(LWLockId lockid, LWLockMode mode);
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extern void LWLockRelease(LWLockId lockid);
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extern void LWLockReleaseAll(void);
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extern int NumLWLocks(void);
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extern int LWLockShmemSize(void);
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extern void CreateLWLocks(void);
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#endif /* LWLOCK_H */
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