Other Alias
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_readerLIBRARY
Concurrency Kit (libck, -lck)SYNOPSIS
In ck_rwlock.hck_rwlock_t lock = CK_RWLOCK_INITIALIZER;
Ft void Fn ck_rwlock_init ck_rwlock_t *lock Ft void Fn ck_rwlock_write_lock ck_rwlock_t *lock Ft void Fn ck_rwlock_write_unlock ck_rwlock_t *lock Ft bool Fn ck_rwlock_write_trylock ck_rwlock_t *lock Ft bool Fn ck_rwlock_write_downgrade ck_rwlock_t *lock Ft bool Fn ck_rwlock_locked_writer ck_rwlock_t *lock Ft void Fn ck_rwlock_read_lock ck_rwlock_t *lock Ft bool Fn ck_rwlock_read_trylock ck_rwlock_t *lock Ft void Fn ck_rwlock_read_unlock ck_rwlock_t *lock Ft bool Fn ck_rwlock_locked_reader ck_rwlock_t *lock
ck_rwlock_recursive_t lock = CK_RWLOCK_RECURSIVE_INITIALIZER;
Ft void Fn ck_rwlock_recursive_write_lock ck_rwlock_recursive_t *lock unsigned int tid Ft bool Fn ck_rwlock_recursive_write_trylock ck_rwlock_recursive_t *lock unsigned int tid Ft void Fn ck_rwlock_recurisve_write_unlock ck_rwlock_recursive_t *lock Ft void Fn ck_rwlock_recursive_read_lock ck_rwlock_recursive_t *lock Ft bool Fn ck_rwlock_recursive_read_trylock ck_rwlock_recursive_t *lock Ft void Fn 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 Fn 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; }