/libs/headers/gc/private/darwin_semaphore.h
http://github.com/nddrylliog/ooc · C++ Header · 68 lines · 53 code · 9 blank · 6 comment · 12 complexity · 14a4a64df372dafcc6121c4d958ed00c MD5 · raw file
- #ifndef GC_DARWIN_SEMAPHORE_H
- #define GC_DARWIN_SEMAPHORE_H
- #if !defined(GC_DARWIN_THREADS)
- #error darwin_semaphore.h included with GC_DARWIN_THREADS not defined
- #endif
- /*
- This is a very simple semaphore implementation for darwin. It
- is implemented in terms of pthreads calls so it isn't async signal
- safe. This isn't a problem because signals aren't used to
- suspend threads on darwin.
- */
-
- typedef struct {
- pthread_mutex_t mutex;
- pthread_cond_t cond;
- int value;
- } sem_t;
- static int sem_init(sem_t *sem, int pshared, int value) {
- int ret;
- if(pshared)
- GC_abort("sem_init with pshared set");
- sem->value = value;
-
- ret = pthread_mutex_init(&sem->mutex,NULL);
- if(ret < 0) return -1;
- ret = pthread_cond_init(&sem->cond,NULL);
- if(ret < 0) return -1;
- return 0;
- }
- static int sem_post(sem_t *sem) {
- if(pthread_mutex_lock(&sem->mutex) < 0)
- return -1;
- sem->value++;
- if(pthread_cond_signal(&sem->cond) < 0) {
- pthread_mutex_unlock(&sem->mutex);
- return -1;
- }
- if(pthread_mutex_unlock(&sem->mutex) < 0)
- return -1;
- return 0;
- }
- static int sem_wait(sem_t *sem) {
- if(pthread_mutex_lock(&sem->mutex) < 0)
- return -1;
- while(sem->value == 0) {
- pthread_cond_wait(&sem->cond,&sem->mutex);
- }
- sem->value--;
- if(pthread_mutex_unlock(&sem->mutex) < 0)
- return -1;
- return 0;
- }
- static int sem_destroy(sem_t *sem) {
- int ret;
- ret = pthread_cond_destroy(&sem->cond);
- if(ret < 0) return -1;
- ret = pthread_mutex_destroy(&sem->mutex);
- if(ret < 0) return -1;
- return 0;
- }
- #endif