ck_rwlock3
Centralized write-biased reader-writer locks
Usage
#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);
Library
Concurrency Kit (libck, -lck)
Overview
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.
Examples
#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;
}
Releases
5 releases since Debian 8 (Jessie); the text changed 1 time.