Adding upstream version 14.5.upstream/14.5upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 616 insertions, 0 deletions

diff --git a/src/include/storage/lock.h b/src/include/storage/lock.h
new file mode 100644
index 0000000..a5286fa
--- /dev/null
+++ b/src/include/storage/lock.h
@@ -0,0 +1,616 @@
+/*-------------------------------------------------------------------------
+ *
+ * lock.h
+ *	  POSTGRES low-level lock mechanism
+ *
+ *
+ * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * src/include/storage/lock.h
+ *
+ *-------------------------------------------------------------------------
+ */
+#ifndef LOCK_H_
+#define LOCK_H_
+
+#ifdef FRONTEND
+#error "lock.h may not be included from frontend code"
+#endif
+
+#include "storage/backendid.h"
+#include "storage/lockdefs.h"
+#include "storage/lwlock.h"
+#include "storage/shmem.h"
+#include "utils/timestamp.h"
+
+/* struct PGPROC is declared in proc.h, but must forward-reference it */
+typedef struct PGPROC PGPROC;
+
+typedef struct PROC_QUEUE
+{
+	SHM_QUEUE	links;			/* head of list of PGPROC objects */
+	int			size;			/* number of entries in list */
+} PROC_QUEUE;
+
+/* GUC variables */
+extern int	max_locks_per_xact;
+
+#ifdef LOCK_DEBUG
+extern int	Trace_lock_oidmin;
+extern bool Trace_locks;
+extern bool Trace_userlocks;
+extern int	Trace_lock_table;
+extern bool Debug_deadlocks;
+#endif							/* LOCK_DEBUG */
+
+
+/*
+ * Top-level transactions are identified by VirtualTransactionIDs comprising
+ * PGPROC fields backendId and lxid.  For recovered prepared transactions, the
+ * LocalTransactionId is an ordinary XID; LOCKTAG_VIRTUALTRANSACTION never
+ * refers to that kind.  These are guaranteed unique over the short term, but
+ * will be reused after a database restart or XID wraparound; hence they
+ * should never be stored on disk.
+ *
+ * Note that struct VirtualTransactionId can not be assumed to be atomically
+ * assignable as a whole.  However, type LocalTransactionId is assumed to
+ * be atomically assignable, and the backend ID doesn't change often enough
+ * to be a problem, so we can fetch or assign the two fields separately.
+ * We deliberately refrain from using the struct within PGPROC, to prevent
+ * coding errors from trying to use struct assignment with it; instead use
+ * GET_VXID_FROM_PGPROC().
+ */
+typedef struct
+{
+	BackendId	backendId;		/* backendId from PGPROC */
+	LocalTransactionId localTransactionId;	/* lxid from PGPROC */
+} VirtualTransactionId;
+
+#define InvalidLocalTransactionId		0
+#define LocalTransactionIdIsValid(lxid) ((lxid) != InvalidLocalTransactionId)
+#define VirtualTransactionIdIsValid(vxid) \
+	(LocalTransactionIdIsValid((vxid).localTransactionId))
+#define VirtualTransactionIdIsRecoveredPreparedXact(vxid) \
+	((vxid).backendId == InvalidBackendId)
+#define VirtualTransactionIdEquals(vxid1, vxid2) \
+	((vxid1).backendId == (vxid2).backendId && \
+	 (vxid1).localTransactionId == (vxid2).localTransactionId)
+#define SetInvalidVirtualTransactionId(vxid) \
+	((vxid).backendId = InvalidBackendId, \
+	 (vxid).localTransactionId = InvalidLocalTransactionId)
+#define GET_VXID_FROM_PGPROC(vxid, proc) \
+	((vxid).backendId = (proc).backendId, \
+	 (vxid).localTransactionId = (proc).lxid)
+
+/* MAX_LOCKMODES cannot be larger than the # of bits in LOCKMASK */
+#define MAX_LOCKMODES		10
+
+#define LOCKBIT_ON(lockmode) (1 << (lockmode))
+#define LOCKBIT_OFF(lockmode) (~(1 << (lockmode)))
+
+
+/*
+ * This data structure defines the locking semantics associated with a
+ * "lock method".  The semantics specify the meaning of each lock mode
+ * (by defining which lock modes it conflicts with).
+ * All of this data is constant and is kept in const tables.
+ *
+ * numLockModes -- number of lock modes (READ,WRITE,etc) that
+ *		are defined in this lock method.  Must be less than MAX_LOCKMODES.
+ *
+ * conflictTab -- this is an array of bitmasks showing lock
+ *		mode conflicts.  conflictTab[i] is a mask with the j-th bit
+ *		turned on if lock modes i and j conflict.  Lock modes are
+ *		numbered 1..numLockModes; conflictTab[0] is unused.
+ *
+ * lockModeNames -- ID strings for debug printouts.
+ *
+ * trace_flag -- pointer to GUC trace flag for this lock method.  (The
+ * GUC variable is not constant, but we use "const" here to denote that
+ * it can't be changed through this reference.)
+ */
+typedef struct LockMethodData
+{
+	int			numLockModes;
+	const LOCKMASK *conflictTab;
+	const char *const *lockModeNames;
+	const bool *trace_flag;
+} LockMethodData;
+
+typedef const LockMethodData *LockMethod;
+
+/*
+ * Lock methods are identified by LOCKMETHODID.  (Despite the declaration as
+ * uint16, we are constrained to 256 lockmethods by the layout of LOCKTAG.)
+ */
+typedef uint16 LOCKMETHODID;
+
+/* These identify the known lock methods */
+#define DEFAULT_LOCKMETHOD	1
+#define USER_LOCKMETHOD		2
+
+/*
+ * LOCKTAG is the key information needed to look up a LOCK item in the
+ * lock hashtable.  A LOCKTAG value uniquely identifies a lockable object.
+ *
+ * The LockTagType enum defines the different kinds of objects we can lock.
+ * We can handle up to 256 different LockTagTypes.
+ */
+typedef enum LockTagType
+{
+	LOCKTAG_RELATION,			/* whole relation */
+	LOCKTAG_RELATION_EXTEND,	/* the right to extend a relation */
+	LOCKTAG_DATABASE_FROZEN_IDS,	/* pg_database.datfrozenxid */
+	LOCKTAG_PAGE,				/* one page of a relation */
+	LOCKTAG_TUPLE,				/* one physical tuple */
+	LOCKTAG_TRANSACTION,		/* transaction (for waiting for xact done) */
+	LOCKTAG_VIRTUALTRANSACTION, /* virtual transaction (ditto) */
+	LOCKTAG_SPECULATIVE_TOKEN,	/* speculative insertion Xid and token */
+	LOCKTAG_OBJECT,				/* non-relation database object */
+	LOCKTAG_USERLOCK,			/* reserved for old contrib/userlock code */
+	LOCKTAG_ADVISORY			/* advisory user locks */
+} LockTagType;
+
+#define LOCKTAG_LAST_TYPE	LOCKTAG_ADVISORY
+
+extern const char *const LockTagTypeNames[];
+
+/*
+ * The LOCKTAG struct is defined with malice aforethought to fit into 16
+ * bytes with no padding.  Note that this would need adjustment if we were
+ * to widen Oid, BlockNumber, or TransactionId to more than 32 bits.
+ *
+ * We include lockmethodid in the locktag so that a single hash table in
+ * shared memory can store locks of different lockmethods.
+ */
+typedef struct LOCKTAG
+{
+	uint32		locktag_field1; /* a 32-bit ID field */
+	uint32		locktag_field2; /* a 32-bit ID field */
+	uint32		locktag_field3; /* a 32-bit ID field */
+	uint16		locktag_field4; /* a 16-bit ID field */
+	uint8		locktag_type;	/* see enum LockTagType */
+	uint8		locktag_lockmethodid;	/* lockmethod indicator */
+} LOCKTAG;
+
+/*
+ * These macros define how we map logical IDs of lockable objects into
+ * the physical fields of LOCKTAG.  Use these to set up LOCKTAG values,
+ * rather than accessing the fields directly.  Note multiple eval of target!
+ */
+
+/* ID info for a relation is DB OID + REL OID; DB OID = 0 if shared */
+#define SET_LOCKTAG_RELATION(locktag,dboid,reloid) \
+	((locktag).locktag_field1 = (dboid), \
+	 (locktag).locktag_field2 = (reloid), \
+	 (locktag).locktag_field3 = 0, \
+	 (locktag).locktag_field4 = 0, \
+	 (locktag).locktag_type = LOCKTAG_RELATION, \
+	 (locktag).locktag_lockmethodid = DEFAULT_LOCKMETHOD)
+
+/* same ID info as RELATION */
+#define SET_LOCKTAG_RELATION_EXTEND(locktag,dboid,reloid) \
+	((locktag).locktag_field1 = (dboid), \
+	 (locktag).locktag_field2 = (reloid), \
+	 (locktag).locktag_field3 = 0, \
+	 (locktag).locktag_field4 = 0, \
+	 (locktag).locktag_type = LOCKTAG_RELATION_EXTEND, \
+	 (locktag).locktag_lockmethodid = DEFAULT_LOCKMETHOD)
+
+/* ID info for frozen IDs is DB OID */
+#define SET_LOCKTAG_DATABASE_FROZEN_IDS(locktag,dboid) \
+	((locktag).locktag_field1 = (dboid), \
+	 (locktag).locktag_field2 = 0, \
+	 (locktag).locktag_field3 = 0, \
+	 (locktag).locktag_field4 = 0, \
+	 (locktag).locktag_type = LOCKTAG_DATABASE_FROZEN_IDS, \
+	 (locktag).locktag_lockmethodid = DEFAULT_LOCKMETHOD)
+
+/* ID info for a page is RELATION info + BlockNumber */
+#define SET_LOCKTAG_PAGE(locktag,dboid,reloid,blocknum) \
+	((locktag).locktag_field1 = (dboid), \
+	 (locktag).locktag_field2 = (reloid), \
+	 (locktag).locktag_field3 = (blocknum), \
+	 (locktag).locktag_field4 = 0, \
+	 (locktag).locktag_type = LOCKTAG_PAGE, \
+	 (locktag).locktag_lockmethodid = DEFAULT_LOCKMETHOD)
+
+/* ID info for a tuple is PAGE info + OffsetNumber */
+#define SET_LOCKTAG_TUPLE(locktag,dboid,reloid,blocknum,offnum) \
+	((locktag).locktag_field1 = (dboid), \
+	 (locktag).locktag_field2 = (reloid), \
+	 (locktag).locktag_field3 = (blocknum), \
+	 (locktag).locktag_field4 = (offnum), \
+	 (locktag).locktag_type = LOCKTAG_TUPLE, \
+	 (locktag).locktag_lockmethodid = DEFAULT_LOCKMETHOD)
+
+/* ID info for a transaction is its TransactionId */
+#define SET_LOCKTAG_TRANSACTION(locktag,xid) \
+	((locktag).locktag_field1 = (xid), \
+	 (locktag).locktag_field2 = 0, \
+	 (locktag).locktag_field3 = 0, \
+	 (locktag).locktag_field4 = 0, \
+	 (locktag).locktag_type = LOCKTAG_TRANSACTION, \
+	 (locktag).locktag_lockmethodid = DEFAULT_LOCKMETHOD)
+
+/* ID info for a virtual transaction is its VirtualTransactionId */
+#define SET_LOCKTAG_VIRTUALTRANSACTION(locktag,vxid) \
+	((locktag).locktag_field1 = (vxid).backendId, \
+	 (locktag).locktag_field2 = (vxid).localTransactionId, \
+	 (locktag).locktag_field3 = 0, \
+	 (locktag).locktag_field4 = 0, \
+	 (locktag).locktag_type = LOCKTAG_VIRTUALTRANSACTION, \
+	 (locktag).locktag_lockmethodid = DEFAULT_LOCKMETHOD)
+
+/*
+ * ID info for a speculative insert is TRANSACTION info +
+ * its speculative insert counter.
+ */
+#define SET_LOCKTAG_SPECULATIVE_INSERTION(locktag,xid,token) \
+	((locktag).locktag_field1 = (xid), \
+	 (locktag).locktag_field2 = (token),		\
+	 (locktag).locktag_field3 = 0, \
+	 (locktag).locktag_field4 = 0, \
+	 (locktag).locktag_type = LOCKTAG_SPECULATIVE_TOKEN, \
+	 (locktag).locktag_lockmethodid = DEFAULT_LOCKMETHOD)
+
+/*
+ * ID info for an object is DB OID + CLASS OID + OBJECT OID + SUBID
+ *
+ * Note: object ID has same representation as in pg_depend and
+ * pg_description, but notice that we are constraining SUBID to 16 bits.
+ * Also, we use DB OID = 0 for shared objects such as tablespaces.
+ */
+#define SET_LOCKTAG_OBJECT(locktag,dboid,classoid,objoid,objsubid) \
+	((locktag).locktag_field1 = (dboid), \
+	 (locktag).locktag_field2 = (classoid), \
+	 (locktag).locktag_field3 = (objoid), \
+	 (locktag).locktag_field4 = (objsubid), \
+	 (locktag).locktag_type = LOCKTAG_OBJECT, \
+	 (locktag).locktag_lockmethodid = DEFAULT_LOCKMETHOD)
+
+#define SET_LOCKTAG_ADVISORY(locktag,id1,id2,id3,id4) \
+	((locktag).locktag_field1 = (id1), \
+	 (locktag).locktag_field2 = (id2), \
+	 (locktag).locktag_field3 = (id3), \
+	 (locktag).locktag_field4 = (id4), \
+	 (locktag).locktag_type = LOCKTAG_ADVISORY, \
+	 (locktag).locktag_lockmethodid = USER_LOCKMETHOD)
+
+
+/*
+ * Per-locked-object lock information:
+ *
+ * tag -- uniquely identifies the object being locked
+ * grantMask -- bitmask for all lock types currently granted on this object.
+ * waitMask -- bitmask for all lock types currently awaited on this object.
+ * procLocks -- list of PROCLOCK objects for this lock.
+ * waitProcs -- queue of processes waiting for this lock.
+ * requested -- count of each lock type currently requested on the lock
+ *		(includes requests already granted!!).
+ * nRequested -- total requested locks of all types.
+ * granted -- count of each lock type currently granted on the lock.
+ * nGranted -- total granted locks of all types.
+ *
+ * Note: these counts count 1 for each backend.  Internally to a backend,
+ * there may be multiple grabs on a particular lock, but this is not reflected
+ * into shared memory.
+ */
+typedef struct LOCK
+{
+	/* hash key */
+	LOCKTAG		tag;			/* unique identifier of lockable object */
+
+	/* data */
+	LOCKMASK	grantMask;		/* bitmask for lock types already granted */
+	LOCKMASK	waitMask;		/* bitmask for lock types awaited */
+	SHM_QUEUE	procLocks;		/* list of PROCLOCK objects assoc. with lock */
+	PROC_QUEUE	waitProcs;		/* list of PGPROC objects waiting on lock */
+	int			requested[MAX_LOCKMODES];	/* counts of requested locks */
+	int			nRequested;		/* total of requested[] array */
+	int			granted[MAX_LOCKMODES]; /* counts of granted locks */
+	int			nGranted;		/* total of granted[] array */
+} LOCK;
+
+#define LOCK_LOCKMETHOD(lock) ((LOCKMETHODID) (lock).tag.locktag_lockmethodid)
+#define LOCK_LOCKTAG(lock) ((LockTagType) (lock).tag.locktag_type)
+
+
+/*
+ * We may have several different backends holding or awaiting locks
+ * on the same lockable object.  We need to store some per-holder/waiter
+ * information for each such holder (or would-be holder).  This is kept in
+ * a PROCLOCK struct.
+ *
+ * PROCLOCKTAG is the key information needed to look up a PROCLOCK item in the
+ * proclock hashtable.  A PROCLOCKTAG value uniquely identifies the combination
+ * of a lockable object and a holder/waiter for that object.  (We can use
+ * pointers here because the PROCLOCKTAG need only be unique for the lifespan
+ * of the PROCLOCK, and it will never outlive the lock or the proc.)
+ *
+ * Internally to a backend, it is possible for the same lock to be held
+ * for different purposes: the backend tracks transaction locks separately
+ * from session locks.  However, this is not reflected in the shared-memory
+ * state: we only track which backend(s) hold the lock.  This is OK since a
+ * backend can never block itself.
+ *
+ * The holdMask field shows the already-granted locks represented by this
+ * proclock.  Note that there will be a proclock object, possibly with
+ * zero holdMask, for any lock that the process is currently waiting on.
+ * Otherwise, proclock objects whose holdMasks are zero are recycled
+ * as soon as convenient.
+ *
+ * releaseMask is workspace for LockReleaseAll(): it shows the locks due
+ * to be released during the current call.  This must only be examined or
+ * set by the backend owning the PROCLOCK.
+ *
+ * Each PROCLOCK object is linked into lists for both the associated LOCK
+ * object and the owning PGPROC object.  Note that the PROCLOCK is entered
+ * into these lists as soon as it is created, even if no lock has yet been
+ * granted.  A PGPROC that is waiting for a lock to be granted will also be
+ * linked into the lock's waitProcs queue.
+ */
+typedef struct PROCLOCKTAG
+{
+	/* NB: we assume this struct contains no padding! */
+	LOCK	   *myLock;			/* link to per-lockable-object information */
+	PGPROC	   *myProc;			/* link to PGPROC of owning backend */
+} PROCLOCKTAG;
+
+typedef struct PROCLOCK
+{
+	/* tag */
+	PROCLOCKTAG tag;			/* unique identifier of proclock object */
+
+	/* data */
+	PGPROC	   *groupLeader;	/* proc's lock group leader, or proc itself */
+	LOCKMASK	holdMask;		/* bitmask for lock types currently held */
+	LOCKMASK	releaseMask;	/* bitmask for lock types to be released */
+	SHM_QUEUE	lockLink;		/* list link in LOCK's list of proclocks */
+	SHM_QUEUE	procLink;		/* list link in PGPROC's list of proclocks */
+} PROCLOCK;
+
+#define PROCLOCK_LOCKMETHOD(proclock) \
+	LOCK_LOCKMETHOD(*((proclock).tag.myLock))
+
+/*
+ * Each backend also maintains a local hash table with information about each
+ * lock it is currently interested in.  In particular the local table counts
+ * the number of times that lock has been acquired.  This allows multiple
+ * requests for the same lock to be executed without additional accesses to
+ * shared memory.  We also track the number of lock acquisitions per
+ * ResourceOwner, so that we can release just those locks belonging to a
+ * particular ResourceOwner.
+ *
+ * When holding a lock taken "normally", the lock and proclock fields always
+ * point to the associated objects in shared memory.  However, if we acquired
+ * the lock via the fast-path mechanism, the lock and proclock fields are set
+ * to NULL, since there probably aren't any such objects in shared memory.
+ * (If the lock later gets promoted to normal representation, we may eventually
+ * update our locallock's lock/proclock fields after finding the shared
+ * objects.)
+ *
+ * Caution: a locallock object can be left over from a failed lock acquisition
+ * attempt.  In this case its lock/proclock fields are untrustworthy, since
+ * the shared lock object is neither held nor awaited, and hence is available
+ * to be reclaimed.  If nLocks > 0 then these pointers must either be valid or
+ * NULL, but when nLocks == 0 they should be considered garbage.
+ */
+typedef struct LOCALLOCKTAG
+{
+	LOCKTAG		lock;			/* identifies the lockable object */
+	LOCKMODE	mode;			/* lock mode for this table entry */
+} LOCALLOCKTAG;
+
+typedef struct LOCALLOCKOWNER
+{
+	/*
+	 * Note: if owner is NULL then the lock is held on behalf of the session;
+	 * otherwise it is held on behalf of my current transaction.
+	 *
+	 * Must use a forward struct reference to avoid circularity.
+	 */
+	struct ResourceOwnerData *owner;
+	int64		nLocks;			/* # of times held by this owner */
+} LOCALLOCKOWNER;
+
+typedef struct LOCALLOCK
+{
+	/* tag */
+	LOCALLOCKTAG tag;			/* unique identifier of locallock entry */
+
+	/* data */
+	uint32		hashcode;		/* copy of LOCKTAG's hash value */
+	LOCK	   *lock;			/* associated LOCK object, if any */
+	PROCLOCK   *proclock;		/* associated PROCLOCK object, if any */
+	int64		nLocks;			/* total number of times lock is held */
+	int			numLockOwners;	/* # of relevant ResourceOwners */
+	int			maxLockOwners;	/* allocated size of array */
+	LOCALLOCKOWNER *lockOwners; /* dynamically resizable array */
+	bool		holdsStrongLockCount;	/* bumped FastPathStrongRelationLocks */
+	bool		lockCleared;	/* we read all sinval msgs for lock */
+} LOCALLOCK;
+
+#define LOCALLOCK_LOCKMETHOD(llock) ((llock).tag.lock.locktag_lockmethodid)
+#define LOCALLOCK_LOCKTAG(llock) ((LockTagType) (llock).tag.lock.locktag_type)
+
+
+/*
+ * These structures hold information passed from lmgr internals to the lock
+ * listing user-level functions (in lockfuncs.c).
+ */
+
+typedef struct LockInstanceData
+{
+	LOCKTAG		locktag;		/* tag for locked object */
+	LOCKMASK	holdMask;		/* locks held by this PGPROC */
+	LOCKMODE	waitLockMode;	/* lock awaited by this PGPROC, if any */
+	BackendId	backend;		/* backend ID of this PGPROC */
+	LocalTransactionId lxid;	/* local transaction ID of this PGPROC */
+	TimestampTz waitStart;		/* time at which this PGPROC started waiting
+								 * for lock */
+	int			pid;			/* pid of this PGPROC */
+	int			leaderPid;		/* pid of group leader; = pid if no group */
+	bool		fastpath;		/* taken via fastpath? */
+} LockInstanceData;
+
+typedef struct LockData
+{
+	int			nelements;		/* The length of the array */
+	LockInstanceData *locks;	/* Array of per-PROCLOCK information */
+} LockData;
+
+typedef struct BlockedProcData
+{
+	int			pid;			/* pid of a blocked PGPROC */
+	/* Per-PROCLOCK information about PROCLOCKs of the lock the pid awaits */
+	/* (these fields refer to indexes in BlockedProcsData.locks[]) */
+	int			first_lock;		/* index of first relevant LockInstanceData */
+	int			num_locks;		/* number of relevant LockInstanceDatas */
+	/* PIDs of PGPROCs that are ahead of "pid" in the lock's wait queue */
+	/* (these fields refer to indexes in BlockedProcsData.waiter_pids[]) */
+	int			first_waiter;	/* index of first preceding waiter */
+	int			num_waiters;	/* number of preceding waiters */
+} BlockedProcData;
+
+typedef struct BlockedProcsData
+{
+	BlockedProcData *procs;		/* Array of per-blocked-proc information */
+	LockInstanceData *locks;	/* Array of per-PROCLOCK information */
+	int		   *waiter_pids;	/* Array of PIDs of other blocked PGPROCs */
+	int			nprocs;			/* # of valid entries in procs[] array */
+	int			maxprocs;		/* Allocated length of procs[] array */
+	int			nlocks;			/* # of valid entries in locks[] array */
+	int			maxlocks;		/* Allocated length of locks[] array */
+	int			npids;			/* # of valid entries in waiter_pids[] array */
+	int			maxpids;		/* Allocated length of waiter_pids[] array */
+} BlockedProcsData;
+
+
+/* Result codes for LockAcquire() */
+typedef enum
+{
+	LOCKACQUIRE_NOT_AVAIL,		/* lock not available, and dontWait=true */
+	LOCKACQUIRE_OK,				/* lock successfully acquired */
+	LOCKACQUIRE_ALREADY_HELD,	/* incremented count for lock already held */
+	LOCKACQUIRE_ALREADY_CLEAR	/* incremented count for lock already clear */
+} LockAcquireResult;
+
+/* Deadlock states identified by DeadLockCheck() */
+typedef enum
+{
+	DS_NOT_YET_CHECKED,			/* no deadlock check has run yet */
+	DS_NO_DEADLOCK,				/* no deadlock detected */
+	DS_SOFT_DEADLOCK,			/* deadlock avoided by queue rearrangement */
+	DS_HARD_DEADLOCK,			/* deadlock, no way out but ERROR */
+	DS_BLOCKED_BY_AUTOVACUUM	/* no deadlock; queue blocked by autovacuum
+								 * worker */
+} DeadLockState;
+
+/*
+ * The lockmgr's shared hash tables are partitioned to reduce contention.
+ * To determine which partition a given locktag belongs to, compute the tag's
+ * hash code with LockTagHashCode(), then apply one of these macros.
+ * NB: NUM_LOCK_PARTITIONS must be a power of 2!
+ */
+#define LockHashPartition(hashcode) \
+	((hashcode) % NUM_LOCK_PARTITIONS)
+#define LockHashPartitionLock(hashcode) \
+	(&MainLWLockArray[LOCK_MANAGER_LWLOCK_OFFSET + \
+		LockHashPartition(hashcode)].lock)
+#define LockHashPartitionLockByIndex(i) \
+	(&MainLWLockArray[LOCK_MANAGER_LWLOCK_OFFSET + (i)].lock)
+
+/*
+ * The deadlock detector needs to be able to access lockGroupLeader and
+ * related fields in the PGPROC, so we arrange for those fields to be protected
+ * by one of the lock hash partition locks.  Since the deadlock detector
+ * acquires all such locks anyway, this makes it safe for it to access these
+ * fields without doing anything extra.  To avoid contention as much as
+ * possible, we map different PGPROCs to different partition locks.  The lock
+ * used for a given lock group is determined by the group leader's pgprocno.
+ */
+#define LockHashPartitionLockByProc(leader_pgproc) \
+	LockHashPartitionLock((leader_pgproc)->pgprocno)
+
+/*
+ * function prototypes
+ */
+extern void InitLocks(void);
+extern LockMethod GetLocksMethodTable(const LOCK *lock);
+extern LockMethod GetLockTagsMethodTable(const LOCKTAG *locktag);
+extern uint32 LockTagHashCode(const LOCKTAG *locktag);
+extern bool DoLockModesConflict(LOCKMODE mode1, LOCKMODE mode2);
+extern LockAcquireResult LockAcquire(const LOCKTAG *locktag,
+									 LOCKMODE lockmode,
+									 bool sessionLock,
+									 bool dontWait);
+extern LockAcquireResult LockAcquireExtended(const LOCKTAG *locktag,
+											 LOCKMODE lockmode,
+											 bool sessionLock,
+											 bool dontWait,
+											 bool reportMemoryError,
+											 LOCALLOCK **locallockp);
+extern void AbortStrongLockAcquire(void);
+extern void MarkLockClear(LOCALLOCK *locallock);
+extern bool LockRelease(const LOCKTAG *locktag,
+						LOCKMODE lockmode, bool sessionLock);
+extern void LockReleaseAll(LOCKMETHODID lockmethodid, bool allLocks);
+extern void LockReleaseSession(LOCKMETHODID lockmethodid);
+extern void LockReleaseCurrentOwner(LOCALLOCK **locallocks, int nlocks);
+extern void LockReassignCurrentOwner(LOCALLOCK **locallocks, int nlocks);
+extern bool LockHeldByMe(const LOCKTAG *locktag, LOCKMODE lockmode);
+#ifdef USE_ASSERT_CHECKING
+extern HTAB *GetLockMethodLocalHash(void);
+#endif
+extern bool LockHasWaiters(const LOCKTAG *locktag,
+						   LOCKMODE lockmode, bool sessionLock);
+extern VirtualTransactionId *GetLockConflicts(const LOCKTAG *locktag,
+											  LOCKMODE lockmode, int *countp);
+extern void AtPrepare_Locks(void);
+extern void PostPrepare_Locks(TransactionId xid);
+extern bool LockCheckConflicts(LockMethod lockMethodTable,
+							   LOCKMODE lockmode,
+							   LOCK *lock, PROCLOCK *proclock);
+extern void GrantLock(LOCK *lock, PROCLOCK *proclock, LOCKMODE lockmode);
+extern void GrantAwaitedLock(void);
+extern void RemoveFromWaitQueue(PGPROC *proc, uint32 hashcode);
+extern Size LockShmemSize(void);
+extern LockData *GetLockStatusData(void);
+extern BlockedProcsData *GetBlockerStatusData(int blocked_pid);
+
+extern xl_standby_lock *GetRunningTransactionLocks(int *nlocks);
+extern const char *GetLockmodeName(LOCKMETHODID lockmethodid, LOCKMODE mode);
+
+extern void lock_twophase_recover(TransactionId xid, uint16 info,
+								  void *recdata, uint32 len);
+extern void lock_twophase_postcommit(TransactionId xid, uint16 info,
+									 void *recdata, uint32 len);
+extern void lock_twophase_postabort(TransactionId xid, uint16 info,
+									void *recdata, uint32 len);
+extern void lock_twophase_standby_recover(TransactionId xid, uint16 info,
+										  void *recdata, uint32 len);
+
+extern DeadLockState DeadLockCheck(PGPROC *proc);
+extern PGPROC *GetBlockingAutoVacuumPgproc(void);
+extern void DeadLockReport(void) pg_attribute_noreturn();
+extern void RememberSimpleDeadLock(PGPROC *proc1,
+								   LOCKMODE lockmode,
+								   LOCK *lock,
+								   PGPROC *proc2);
+extern void InitDeadLockChecking(void);
+
+extern int	LockWaiterCount(const LOCKTAG *locktag);
+
+#ifdef LOCK_DEBUG
+extern void DumpLocks(PGPROC *proc);
+extern void DumpAllLocks(void);
+#endif
+
+/* Lock a VXID (used to wait for a transaction to finish) */
+extern void VirtualXactLockTableInsert(VirtualTransactionId vxid);
+extern void VirtualXactLockTableCleanup(void);
+extern bool VirtualXactLock(VirtualTransactionId vxid, bool wait);
+
+#endif							/* LOCK_H_ */