1 #include <semaphore.h> 2 #include "pthread_impl.h" 3 cleanup(void * p)4static void cleanup(void *p) 5 { 6 a_dec(p); 7 } 8 sem_timedwait(sem_t * restrict sem,const struct timespec * restrict at)9int sem_timedwait(sem_t *restrict sem, const struct timespec *restrict at) 10 { 11 pthread_testcancel(); 12 13 if (!sem_trywait(sem)) return 0; 14 15 int spins = 100; 16 while (spins-- && sem->__val[0] <= 0 && !sem->__val[1]) a_spin(); 17 18 while (sem_trywait(sem)) { 19 int r; 20 a_inc(sem->__val+1); 21 a_cas(sem->__val, 0, -1); 22 pthread_cleanup_push(cleanup, (void *)(sem->__val+1)); 23 r = __timedwait_cp(sem->__val, -1, CLOCK_REALTIME, at, sem->__val[2]); 24 pthread_cleanup_pop(1); 25 if (r) { 26 errno = r; 27 return -1; 28 } 29 } 30 return 0; 31 } 32