X-Git-Url: http://nsz.repo.hu/git/?p=musl;a=blobdiff_plain;f=src%2Fthread%2Fsem_trywait.c;h=04edf46b524de72a575b1db7687f56d93fc1e291;hp=dd8f57e36a0bd54a60a5b4c21516b9a1b6a8bba5;hb=8c0a3d9e5c169fc9d0f246ab59362b658b029ad7;hpb=e983aea0aec4b77cd3eb39dabc763b08c4485395

diff --git a/src/thread/sem_trywait.c b/src/thread/sem_trywait.c
index dd8f57e3..04edf46b 100644
--- a/src/thread/sem_trywait.c
+++ b/src/thread/sem_trywait.c
@@ -3,8 +3,11 @@
 
 int sem_trywait(sem_t *sem)
 {
-	int val = sem->__val[0];
-	if (val>0 && a_cas(sem->__val, val, val-1)==val) return 0;
+	int val;
+	while ((val=sem->__val[0]) > 0) {
+		int new = val-1-(val==1 && sem->__val[1]);
+		if (a_cas(sem->__val, val, new)==val) return 0;
+	}
 	errno = EAGAIN;
 	return -1;
 }