refrain from spinning on locks when there is already a waiter

[musl] / src / thread / sem_timedwait.c

diff --git a/src/thread/sem_timedwait.c b/src/thread/sem_timedwait.c
index df5f3a6..b5a60ad 100644 (file)
--- a/src/thread/sem_timedwait.c
+++ b/src/thread/sem_timedwait.c
@@ -11,7 +11,7 @@ int sem_timedwait(sem_t *restrict sem, const struct timespec *restrict at)
        if (!sem_trywait(sem)) return 0;
 
        int spins = 100;
-       while (spins-- && sem->__val[0] <= 0) a_spin();
+       while (spins-- && sem->__val[0] <= 0 && !sem->__val[1]) a_spin();
 
        while (sem_trywait(sem)) {
                int r;