make all objects used with atomic operations volatile

[musl] / src / thread / sem_timedwait.c

diff --git a/src/thread/sem_timedwait.c b/src/thread/sem_timedwait.c
index e660436..8132eb1 100644 (file)
--- a/src/thread/sem_timedwait.c
+++ b/src/thread/sem_timedwait.c
@@ -1,18 +1,31 @@
 #include <semaphore.h>
 #include "pthread_impl.h"
 
-int sem_timedwait(sem_t *sem, const struct timespec *at)
+static void cleanup(void *p)
 {
-       int val;
+       a_dec(p);
+}
+
+int sem_timedwait(sem_t *restrict sem, const struct timespec *restrict at)
+{
+       pthread_testcancel();
+
+       if (!sem_trywait(sem)) return 0;
+
+       int spins = 100;
+       while (spins-- && sem->__val[0] <= 0 && !sem->__val[1]) a_spin();
 
-       for (;;) {
-               if (a_fetch_add(sem->__val, -1) > 0) return 0;
-               val = a_fetch_add(sem->__val, 1);
-               CANCELPT_BEGIN;
-               if (val <= 0 && __timedwait(sem->__val, val, CLOCK_REALTIME, at, 0) == ETIMEDOUT) {
-                       errno = ETIMEDOUT;
+       while (sem_trywait(sem)) {
+               int r;
+               a_inc(sem->__val+1);
+               a_cas(sem->__val, 0, -1);
+               pthread_cleanup_push(cleanup, (void *)(sem->__val+1));
+               r = __timedwait_cp(sem->__val, -1, CLOCK_REALTIME, at, sem->__val[2]);
+               pthread_cleanup_pop(1);
+               if (r && r != EINTR) {
+                       errno = r;
                        return -1;
                }
-               CANCELPT_END;
        }
+       return 0;
 }