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Convert the lock manager to use the new dynahash.c support for partitioned

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hash tables, instead of the previous kluge involving multiple hash tables.
This partially undoes my patch of last December.
This commit is contained in:
Tom Lane
2006-07-23 23:08:46 +00:00
parent b25dc481c8
commit a794fb0681
7 changed files with 306 additions and 235 deletions
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42
src/include/storage/lock.h
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@@ -7,7 +7,7 @@
* Portions Copyright (c) 1996-2006, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* $PostgreSQL: pgsql/src/include/storage/lock.h,v 1.95 2006/07/23 03:07:58 tgl Exp $
* $PostgreSQL: pgsql/src/include/storage/lock.h,v 1.96 2006/07/23 23:08:46 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -266,7 +266,9 @@ typedef struct LOCK
*
* 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.
* 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
@@ -292,8 +294,9 @@ typedef struct LOCK
*/
typedef struct PROCLOCKTAG
{
SHMEM_OFFSET lock; /* link to per-lockable-object information */
SHMEM_OFFSET proc; /* link to PGPROC of owning backend */
/* 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
@@ -309,7 +312,7 @@ typedef struct PROCLOCK
} PROCLOCK;
#define PROCLOCK_LOCKMETHOD(proclock) \
LOCK_LOCKMETHOD(*((LOCK *) MAKE_PTR((proclock).tag.lock)))
LOCK_LOCKMETHOD(*((proclock).tag.myLock))
/*
* Each backend also maintains a local hash table with information about each
@@ -347,7 +350,7 @@ typedef struct LOCALLOCK
LOCK *lock; /* associated LOCK object in shared mem */
PROCLOCK *proclock; /* associated PROCLOCK object in shmem */
bool isTempObject; /* true if lock is on a temporary object */
int partition; /* ID of partition containing this lock */
uint32 hashcode; /* copy of LOCKTAG's hash value */
int nLocks; /* total number of times lock is held */
int numLockOwners; /* # of relevant ResourceOwners */
int maxLockOwners; /* allocated size of array */
@@ -360,15 +363,14 @@ typedef struct LOCALLOCK
/*
* This struct holds information passed from lmgr internals to the lock
* listing user-level functions (lockfuncs.c). For each PROCLOCK in the
* system, the SHMEM_OFFSET, PROCLOCK itself, and associated PGPROC and
* LOCK objects are stored. (Note there will often be multiple copies
* of the same PGPROC or LOCK.) We do not store the SHMEM_OFFSET of the
* PGPROC or LOCK separately, since they're in the PROCLOCK's tag fields.
* system, copies of the PROCLOCK object and associated PGPROC and
* LOCK objects are stored. Note there will often be multiple copies
* of the same PGPROC or LOCK --- to detect whether two are the same,
* compare the PROCLOCK tag fields.
*/
typedef struct
typedef struct LockData
{
int nelements; /* The length of each of the arrays */
SHMEM_OFFSET *proclockaddrs;
PROCLOCK *proclocks;
PGPROC *procs;
LOCK *locks;
@@ -384,12 +386,24 @@ typedef enum
} LockAcquireResult;
/*
* 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) \
((LWLockId) (FirstLockMgrLock + LockHashPartition(hashcode)))
/*
* function prototypes
*/
extern void InitLocks(void);
extern LockMethod GetLocksMethodTable(const LOCK *lock);
extern int LockTagToPartition(const LOCKTAG *locktag);
extern uint32 LockTagHashCode(const LOCKTAG *locktag);
extern LockAcquireResult LockAcquire(const LOCKTAG *locktag,
bool isTempObject,
LOCKMODE lockmode,
@@ -407,7 +421,7 @@ extern int LockCheckConflicts(LockMethod lockMethodTable,
LOCK *lock, PROCLOCK *proclock, PGPROC *proc);
extern void GrantLock(LOCK *lock, PROCLOCK *proclock, LOCKMODE lockmode);
extern void GrantAwaitedLock(void);
extern void RemoveFromWaitQueue(PGPROC *proc, int partition);
extern void RemoveFromWaitQueue(PGPROC *proc, uint32 hashcode);
extern Size LockShmemSize(void);
extern bool DeadLockCheck(PGPROC *proc);
extern void DeadLockReport(void);