ck_swlock_init, ck_swlock_write_latch, ck_swlock_write_unlatch, ck_swlock_write_lock,
Contents
Description
This is a centralized write-biased single-writer reader-writer lock. It requires half the space that
ck_rwlock does and has a low latency fast path. The lock supports latch and unlatch operations that allow
it to be used in a copy-safe manner (reader-bits may be over-written safely).
Example
#include <ck_swlock.h>
static ck_swlock_t lock = CK_SWLOCK_INITIALIZER;
static void
reader(void)
{
for (;;) {
ck_swlock_read_lock(&lock);
/* Read-side critical section. */
ck_swlock_read_unlock(&lock);
if (ck_swlock_read_trylock(&lock) == true) {
/* Read-side critical section. */
ck_swlock_read_unlock(&lock);
}
}
return;
}
static void
writer(void)
{
ck_swlock_t contrived;
for (;;) {
ck_swlock_write_lock(&lock);
/* Write-side critical section. */
ck_swlock_write_unlock(&lock);
if (ck_swlock_write_trylock(&lock) == true) {
/* Write-side critical section. */
ck_swlock_write_unlock(&lock);
}
ck_swlock_write_latch(&lock);
/* Write-side critical section. */
/* This is safe to do with-in a latch. */
contrived = lock;
lock = contrived;
ck_swlock_write_unlatch(&lock);
}
return;
}
Library
Concurrency Kit (libck, -lck)
Name
ck_swlock_init, ck_swlock_write_latch, ck_swlock_write_unlatch, ck_swlock_write_lock,
ck_swlock_write_unlock, ck_swlock_write_trylock, ck_swlock_write_downgrade, ck_swlock_locked_writer,
ck_swlock_read_lock, ck_swlock_read_trylock, ck_swlock_read_unlock, ck_swlock_locked_reader — centralized
copy-safe write-biased single-writer read-write locks
See Also
ck_brlock(3), ck_elide(3), ck_pflock(3), ck_rwlock(3), ck_tflock(3) Additional information available at http://concurrencykit.org/ April 22, 2014. ck_swlock(3)
Synopsis
#include<ck_swlock.h>
ck_swlock_t lock = CK_SWLOCK_INITIALIZER;
voidck_swlock_init(ck_swlock_t*lock);
voidck_swlock_write_lock(ck_swlock_t*lock);
voidck_swlock_write_unlock(ck_swlock_t*lock);
voidck_swlatch_write_latch(ck_swlatch_t*latch);
voidck_swlatch_write_unlatch(ck_swlatch_t*latch);
boolck_swlock_write_trylock(ck_swlock_t*lock);
boolck_swlock_write_downgrade(ck_swlock_t*lock);
boolck_swlock_locked_writer(ck_swlock_t*lock);
voidck_swlock_read_lock(ck_swlock_t*lock);
boolck_swlock_read_trylock(ck_swlock_t*lock);
voidck_swlock_read_unlock(ck_swlock_t*lock);
boolck_swlock_locked_reader(ck_swlock_t*lock);
