nsz Git - musl/blob - src/thread/sem_timedwait.c

   1 #include <semaphore.h>
   2 #include "pthread_impl.h"
   3
   4 int sem_timedwait(sem_t *sem, const struct timespec *at)
   5 {
   6         int val;
   7
   8         for (;;) {
   9                 if (a_fetch_add(sem->__val, -1) > 0) return 0;
  10                 val = a_fetch_add(sem->__val, 1)+1;
  11                 CANCELPT_BEGIN;
  12                 if (val <= 0 && __timedwait(sem->__val, val, CLOCK_REALTIME, at, 0) == ETIMEDOUT) {
  13                         errno = ETIMEDOUT;
  14                         return -1;
  15                 }
  16                 CANCELPT_END;
  17         }
  18 }