init

2026-04-07 13:35:22 +08:00
commit 0120fa9ce3
1530 changed files with 424864 additions and 0 deletions
--- a/pg_include/storage/lwlock.h
+++ b/pg_include/storage/lwlock.h
@@ -0,0 +1,122 @@
+/*-------------------------------------------------------------------------
+ *
+ * lwlock.h
+ *	  Lightweight lock manager
+ *
+ *
+ * Portions Copyright (c) 1996-2012, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * src/include/storage/lwlock.h
+ *
+ *-------------------------------------------------------------------------
+ */
+#ifndef LWLOCK_H
+#define LWLOCK_H
+
+/*
+ * It's a bit odd to declare NUM_BUFFER_PARTITIONS and NUM_LOCK_PARTITIONS
+ * here, but we need them to set up enum LWLockId correctly, and having
+ * this file include lock.h or bufmgr.h would be backwards.
+ */
+
+/* Number of partitions of the shared buffer mapping hashtable */
+#define NUM_BUFFER_PARTITIONS  16
+
+/* Number of partitions the shared lock tables are divided into */
+#define LOG2_NUM_LOCK_PARTITIONS  4
+#define NUM_LOCK_PARTITIONS  (1 << LOG2_NUM_LOCK_PARTITIONS)
+
+/* Number of partitions the shared predicate lock tables are divided into */
+#define LOG2_NUM_PREDICATELOCK_PARTITIONS  4
+#define NUM_PREDICATELOCK_PARTITIONS  (1 << LOG2_NUM_PREDICATELOCK_PARTITIONS)
+
+/*
+ * We have a number of predefined LWLocks, plus a bunch of LWLocks that are
+ * dynamically assigned (e.g., for shared buffers).  The LWLock structures
+ * live in shared memory (since they contain shared data) and are identified
+ * by values of this enumerated type.  We abuse the notion of an enum somewhat
+ * by allowing values not listed in the enum declaration to be assigned.
+ * The extra value MaxDynamicLWLock is there to keep the compiler from
+ * deciding that the enum can be represented as char or short ...
+ *
+ * If you remove a lock, please replace it with a placeholder. This retains
+ * the lock numbering, which is helpful for DTrace and other external
+ * debugging scripts.
+ */
+typedef enum LWLockId
+{
+	BufFreelistLock,
+	ShmemIndexLock,
+	OidGenLock,
+	XidGenLock,
+	ProcArrayLock,
+	SInvalReadLock,
+	SInvalWriteLock,
+	WALInsertLock,
+	WALWriteLock,
+	ControlFileLock,
+	CheckpointLock,
+	CLogControlLock,
+	SubtransControlLock,
+	MultiXactGenLock,
+	MultiXactOffsetControlLock,
+	MultiXactMemberControlLock,
+	RelCacheInitLock,
+	CheckpointerCommLock,
+	TwoPhaseStateLock,
+	TablespaceCreateLock,
+	BtreeVacuumLock,
+	AddinShmemInitLock,
+	AutovacuumLock,
+	AutovacuumScheduleLock,
+	SyncScanLock,
+	RelationMappingLock,
+	AsyncCtlLock,
+	AsyncQueueLock,
+	SerializableXactHashLock,
+	SerializableFinishedListLock,
+	SerializablePredicateLockListLock,
+	OldSerXidLock,
+	SyncRepLock,
+	/* Individual lock IDs end here */
+	FirstBufMappingLock,
+	FirstLockMgrLock = FirstBufMappingLock + NUM_BUFFER_PARTITIONS,
+	FirstPredicateLockMgrLock = FirstLockMgrLock + NUM_LOCK_PARTITIONS,
+
+	/* must be last except for MaxDynamicLWLock: */
+	NumFixedLWLocks = FirstPredicateLockMgrLock + NUM_PREDICATELOCK_PARTITIONS,
+
+	MaxDynamicLWLock = 1000000000
+} LWLockId;
+
+
+typedef enum LWLockMode
+{
+	LW_EXCLUSIVE,
+	LW_SHARED,
+	LW_WAIT_UNTIL_FREE			/* A special mode used in PGPROC->lwlockMode,
+								 * when waiting for lock to become free. Not
+								 * to be used as LWLockAcquire argument */
+} LWLockMode;
+
+
+#ifdef LOCK_DEBUG
+extern bool Trace_lwlocks;
+#endif
+
+extern LWLockId LWLockAssign(void);
+extern void LWLockAcquire(LWLockId lockid, LWLockMode mode);
+extern bool LWLockConditionalAcquire(LWLockId lockid, LWLockMode mode);
+extern bool LWLockAcquireOrWait(LWLockId lockid, LWLockMode mode);
+extern void LWLockRelease(LWLockId lockid);
+extern void LWLockReleaseAll(void);
+extern bool LWLockHeldByMe(LWLockId lockid);
+
+extern int	NumLWLocks(void);
+extern Size LWLockShmemSize(void);
+extern void CreateLWLocks(void);
+
+extern void RequestAddinLWLocks(int n);
+
+#endif   /* LWLOCK_H */