remove no-longer-needed unblocking of signals in pthread_create
[musl] / src / thread / sem_trywait.c
index beb7aa5..55d9007 100644 (file)
@@ -3,9 +3,11 @@
 
 int sem_trywait(sem_t *sem)
 {
-       if (a_fetch_add(sem->__val, -1) > 0) return 0;
-       if (!a_fetch_add(sem->__val, 1) && sem->__val[1])
-               __wake(sem->__val, 1, 0);
+       int val = sem->__val[0];
+       if (val>0) {
+               int new = val-1-(val==1 && sem->__val[1]);
+               if (a_cas(sem->__val, val, new)==val) return 0;
+       }
        errno = EAGAIN;
        return -1;
 }