+ pthread_mutex_lock(&mutex->lock);
+
+ while (!mutex->value) {
+ mutex->waiters++;
+ pthread_cond_wait(&mutex->cond, &mutex->lock);
+ mutex->waiters--;
+ }
+
+ mutex->value--;
+ pthread_mutex_unlock(&mutex->lock);
+}
+
+void fio_mutex_up(struct fio_mutex *mutex)
+{
+ pthread_mutex_lock(&mutex->lock);
+ read_barrier();
+ if (!mutex->value && mutex->waiters)
+ pthread_cond_signal(&mutex->cond);
+ mutex->value++;
+ pthread_mutex_unlock(&mutex->lock);
+}
+
+void fio_rwlock_write(struct fio_rwlock *lock)
+{
+ pthread_rwlock_wrlock(&lock->lock);
+}
+
+void fio_rwlock_read(struct fio_rwlock *lock)
+{
+ pthread_rwlock_rdlock(&lock->lock);
+}
+
+void fio_rwlock_unlock(struct fio_rwlock *lock)
+{
+ pthread_rwlock_unlock(&lock->lock);
+}
+
+void fio_rwlock_remove(struct fio_rwlock *lock)
+{
+ munmap((void *) lock, sizeof(*lock));
+}
+
+struct fio_rwlock *fio_rwlock_init(void)
+{
+ struct fio_rwlock *lock;
+ int ret;
+
+ lock = (void *) mmap(NULL, sizeof(struct fio_rwlock),
+ PROT_READ | PROT_WRITE,
+ OS_MAP_ANON | MAP_SHARED, -1, 0);
+ if (lock == MAP_FAILED) {
+ perror("mmap rwlock");
+ lock = NULL;
+ goto err;
+ }
+
+ ret = pthread_rwlock_init(&lock->lock, NULL);
+ if (ret) {
+ log_err("pthread_rwlock_init: %s\n", strerror(ret));
+ goto err;
+ }
+
+ return lock;
+err:
+ if (lock)
+ fio_rwlock_remove(lock);
+ return NULL;