1 #include <semaphore.h>
2 #include "pthread_impl.h"
3
cleanup(void * p)4 static void cleanup(void *p)
5 {
6 a_dec(p);
7 }
__sem_timedwait(sem_t * restrict sem,const struct timespec * restrict at)8 int __sem_timedwait(sem_t *restrict sem, const struct timespec *restrict at)
9 {
10 int spins = 100;
11 while (spins-- && sem->__val[0] <= 0 && !sem->__val[1]) a_spin();
12
13 while (sem_trywait(sem)) {
14 int r;
15 a_inc(sem->__val+1);
16 a_cas(sem->__val, 0, -1);
17 pthread_cleanup_push(cleanup, (void *)(sem->__val+1));
18 r = __timedwait_cp(sem->__val, -1, CLOCK_REALTIME, at, sem->__val[2]);
19 pthread_cleanup_pop(1);
20 if (r) {
21 errno = r;
22 return -1;
23 }
24 }
25 return 0;
26 }
sem_timedwait(sem_t * restrict sem,const struct timespec * restrict at)27 int sem_timedwait(sem_t *restrict sem, const struct timespec *restrict at)
28 {
29 pthread_testcancel();
30
31 if (!sem_trywait(sem)) return 0;
32
33 return __sem_timedwait(sem, at);
34 }
35