diff options
Diffstat (limited to 'src/support/mtx_rw.c')
| -rw-r--r-- | src/support/mtx_rw.c | 93 |
1 files changed, 28 insertions, 65 deletions
diff --git a/src/support/mtx_rw.c b/src/support/mtx_rw.c index ea18f556257..35ad5da23f2 100644 --- a/src/support/mtx_rw.c +++ b/src/support/mtx_rw.c @@ -115,23 +115,27 @@ #include "wt_internal.h" /* - * __wt_rwlock_alloc -- - * Allocate and initialize a read/write lock. + * __wt_rwlock_init -- + * Initialize a read/write lock. */ -int -__wt_rwlock_alloc( - WT_SESSION_IMPL *session, WT_RWLOCK **rwlockp, const char *name) +void +__wt_rwlock_init(WT_SESSION_IMPL *session, WT_RWLOCK *l) { - WT_RWLOCK *rwlock; - - __wt_verbose(session, WT_VERB_MUTEX, "rwlock: alloc %s", name); + WT_UNUSED(session); - WT_RET(__wt_calloc_one(session, &rwlock)); + l->u = 0; +} - rwlock->name = name; +/* + * __wt_rwlock_destroy -- + * Destroy a read/write lock. + */ +void +__wt_rwlock_destroy(WT_SESSION_IMPL *session, WT_RWLOCK *l) +{ + WT_UNUSED(session); - *rwlockp = rwlock; - return (0); + l->u = 0; } /* @@ -139,13 +143,12 @@ __wt_rwlock_alloc( * Try to get a shared lock, fail immediately if unavailable. */ int -__wt_try_readlock(WT_SESSION_IMPL *session, WT_RWLOCK *rwlock) +__wt_try_readlock(WT_SESSION_IMPL *session, WT_RWLOCK *l) { - wt_rwlock_t *l, new, old; + WT_RWLOCK new, old; WT_STAT_CONN_INCR(session, rwlock_read); - l = &rwlock->rwlock; new = old = *l; /* @@ -172,19 +175,15 @@ __wt_try_readlock(WT_SESSION_IMPL *session, WT_RWLOCK *rwlock) * exclusive. */ void -__wt_readlock_spin(WT_SESSION_IMPL *session, WT_RWLOCK *rwlock) +__wt_readlock_spin(WT_SESSION_IMPL *session, WT_RWLOCK *l) { - wt_rwlock_t *l; - - l = &rwlock->rwlock; - /* * Try to get the lock in a single operation if it is available to * readers. This avoids the situation where multiple readers arrive * concurrently and have to line up in order to enter the lock. For * read-heavy workloads it can make a significant difference. */ - while (__wt_try_readlock(session, rwlock) != 0) { + while (__wt_try_readlock(session, l) != 0) { if (l->s.writers_active > 0) __wt_yield(); else @@ -197,9 +196,8 @@ __wt_readlock_spin(WT_SESSION_IMPL *session, WT_RWLOCK *rwlock) * Get a shared lock. */ void -__wt_readlock(WT_SESSION_IMPL *session, WT_RWLOCK *rwlock) +__wt_readlock(WT_SESSION_IMPL *session, WT_RWLOCK *l) { - wt_rwlock_t *l; uint16_t ticket; int pause_cnt; @@ -207,8 +205,6 @@ __wt_readlock(WT_SESSION_IMPL *session, WT_RWLOCK *rwlock) WT_DIAGNOSTIC_YIELD; - l = &rwlock->rwlock; - /* * Possibly wrap: if we have more than 64K lockers waiting, the ticket * value will wrap and two lockers will simultaneously be granted the @@ -246,14 +242,10 @@ __wt_readlock(WT_SESSION_IMPL *session, WT_RWLOCK *rwlock) * Release a shared lock. */ void -__wt_readunlock(WT_SESSION_IMPL *session, WT_RWLOCK *rwlock) +__wt_readunlock(WT_SESSION_IMPL *session, WT_RWLOCK *l) { - wt_rwlock_t *l; - WT_UNUSED(session); - l = &rwlock->rwlock; - /* * Increment the writers value (other readers are doing the same, make * sure we don't race). @@ -266,13 +258,12 @@ __wt_readunlock(WT_SESSION_IMPL *session, WT_RWLOCK *rwlock) * Try to get an exclusive lock, fail immediately if unavailable. */ int -__wt_try_writelock(WT_SESSION_IMPL *session, WT_RWLOCK *rwlock) +__wt_try_writelock(WT_SESSION_IMPL *session, WT_RWLOCK *l) { - wt_rwlock_t *l, new, old; + WT_RWLOCK new, old; WT_STAT_CONN_INCR(session, rwlock_write); - l = &rwlock->rwlock; old = new = *l; /* @@ -296,16 +287,13 @@ __wt_try_writelock(WT_SESSION_IMPL *session, WT_RWLOCK *rwlock) * Wait to get an exclusive lock. */ void -__wt_writelock(WT_SESSION_IMPL *session, WT_RWLOCK *rwlock) +__wt_writelock(WT_SESSION_IMPL *session, WT_RWLOCK *l) { - wt_rwlock_t *l; uint16_t ticket; int pause_cnt; WT_STAT_CONN_INCR(session, rwlock_write); - l = &rwlock->rwlock; - /* * Possibly wrap: if we have more than 64K lockers waiting, the ticket * value will wrap and two lockers will simultaneously be granted the @@ -338,13 +326,12 @@ __wt_writelock(WT_SESSION_IMPL *session, WT_RWLOCK *rwlock) * Release an exclusive lock. */ void -__wt_writeunlock(WT_SESSION_IMPL *session, WT_RWLOCK *rwlock) +__wt_writeunlock(WT_SESSION_IMPL *session, WT_RWLOCK *l) { - wt_rwlock_t *l, new; + WT_RWLOCK new; WT_UNUSED(session); - l = &rwlock->rwlock; (void)__wt_atomic_sub16(&l->s.writers_active, 1); /* @@ -368,40 +355,16 @@ __wt_writeunlock(WT_SESSION_IMPL *session, WT_RWLOCK *rwlock) WT_DIAGNOSTIC_YIELD; } -/* - * __wt_rwlock_destroy -- - * Destroy a read/write lock. - */ -void -__wt_rwlock_destroy(WT_SESSION_IMPL *session, WT_RWLOCK **rwlockp) -{ - WT_RWLOCK *rwlock; - - rwlock = *rwlockp; /* Clear our caller's reference. */ - if (rwlock == NULL) - return; - *rwlockp = NULL; - - __wt_verbose( - session, WT_VERB_MUTEX, "rwlock: destroy %s", rwlock->name); - - __wt_free(session, rwlock); -} - #ifdef HAVE_DIAGNOSTIC /* * __wt_rwlock_islocked -- * Return if a read/write lock is currently locked for reading or writing. */ bool -__wt_rwlock_islocked(WT_SESSION_IMPL *session, WT_RWLOCK *rwlock) +__wt_rwlock_islocked(WT_SESSION_IMPL *session, WT_RWLOCK *l) { - wt_rwlock_t *l; - WT_UNUSED(session); - l = &rwlock->rwlock; - return (l->s.writers != l->s.next || l->s.readers != l->s.next); } #endif |