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NAME ck_rwlock_init, ck_rwlock_write_lock, ck_rwlock_write_unlock, ck_rwlock_write_trylock, ck_rwlock_write_downgrade, ck_rwlock_locked_writer, ck_rwlock_read_lock, ck_rwlock_read_trylock, ck_rwlock_read_unlock, ck_rwlock_locked_reader, ck_rwlock_recursive_write_lock, ck_rwlock_recursive_write_trylock, ck_rwlock_recurisve_write_unlock, ck_rwlock_recursive_read_lock, ck_rwlock_recursive_read_trylock, ck_rwlock_recursive_read_unlock -- cen- tralized write-biased reader-writer locks LIBRARY Concurrency Kit (libck, -lck) SYNOPSIS #include <ck_rwlock.h> ck_rwlock_t lock = CK_RWLOCK_INITIALIZER; void ck_rwlock_init(ck_rwlock_t *lock); void ck_rwlock_write_lock(ck_rwlock_t *lock); void ck_rwlock_write_unlock(ck_rwlock_t *lock); bool ck_rwlock_write_trylock(ck_rwlock_t *lock); bool ck_rwlock_write_downgrade(ck_rwlock_t *lock); bool ck_rwlock_locked_writer(ck_rwlock_t *lock); void ck_rwlock_read_lock(ck_rwlock_t *lock); bool ck_rwlock_read_trylock(ck_rwlock_t *lock); void ck_rwlock_read_unlock(ck_rwlock_t *lock); bool ck_rwlock_locked_reader(ck_rwlock_t *lock); ck_rwlock_recursive_t lock = CK_RWLOCK_RECURSIVE_INITIALIZER; void ck_rwlock_recursive_write_lock(ck_rwlock_recursive_t *lock, unsigned int tid); bool ck_rwlock_recursive_write_trylock(ck_rwlock_recursive_t *lock, unsigned int tid); void ck_rwlock_recurisve_write_unlock(ck_rwlock_recursive_t *lock); void ck_rwlock_recursive_read_lock(ck_rwlock_recursive_t *lock); bool ck_rwlock_recursive_read_trylock(ck_rwlock_recursive_t *lock); void ck_rwlock_recursive_read_unlock(ck_rwlock_recursive_t *lock); DESCRIPTION This is a centralized write-biased reader-writer lock. It requires very little space overhead and has a low latency fast path. Write-side recursion requires usage of ck_rwlock_recursive. Read-side recursion is disallowed. The ck_rwlock_write_downgrade() function degrades the caller's write-side acquisition to a read-side acquisition without forfeit of current critical section. EXAMPLE #include <ck_rwlock.h> static ck_rwlock_t lock = CK_RWLOCK_INITIALIZER; static void reader(void) { for (;;) { ck_rwlock_read_lock(&lock); /* Read-side critical section. */ ck_rwlock_read_unlock(&lock); if (ck_rwlock_read_trylock(&lock) == true) { /* Read-side critical section. */ ck_rwlock_read_unlock(&lock); } } return; } static void writer(void) { for (;;) { ck_rwlock_write_lock(&lock); /* Write-side critical section. */ ck_rwlock_write_unlock(&lock); if (ck_rwlock_write_trylock(&lock, 1) == true) { /* Write-side critical section. */ ck_rwlock_write_unlock(&lock); } } return; } SEE ALSO ck_brlock(3), ck_elide(3) Additional information available at http://concurrencykit.org/ July 26, 2013. ck_rwlock(3)
NAME | LIBRARY | SYNOPSIS | DESCRIPTION | EXAMPLE | SEE ALSO
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