X-Git-Url: http://nsz.repo.hu/git/?p=musl;a=blobdiff_plain;f=src%2Fthread%2Fpthread_rwlock_tryrdlock.c;h=fa271fcc6a156a78e9dfe975bf084113e3aa3167;hp=fc1d5328a787dc6df63db2cc265227c795e9b394;hb=d432b2c057fc64256645422382c2f7e32c45b3cc;hpb=e882756311c7b06e59fcc8e582f03852b7dcfd30

diff --git a/src/thread/pthread_rwlock_tryrdlock.c b/src/thread/pthread_rwlock_tryrdlock.c
index fc1d5328..fa271fcc 100644
--- a/src/thread/pthread_rwlock_tryrdlock.c
+++ b/src/thread/pthread_rwlock_tryrdlock.c
@@ -2,12 +2,12 @@
 
 int pthread_rwlock_tryrdlock(pthread_rwlock_t *rw)
 {
-	a_inc(&rw->_rw_readers);
-	if (rw->_rw_wrlock) {
-		a_dec(&rw->_rw_readers);
-		if (rw->_rw_waiters && !rw->_rw_readers)
-			__wake(&rw->_rw_readers, 1, 0);
-		return EAGAIN;
-	}
+	int val, cnt;
+	do {
+		val = rw->_rw_lock;
+		cnt = val & 0x7fffffff;
+		if (cnt == 0x7fffffff) return EBUSY;
+		if (cnt == 0x7ffffffe) return EAGAIN;
+	} while (a_cas(&rw->_rw_lock, val, val+1) != val);
 	return 0;
 }