dummy implementation of set_thread_area

[musl] / src / thread / pthread_rwlock_tryrdlock.c

diff --git a/src/thread/pthread_rwlock_tryrdlock.c b/src/thread/pthread_rwlock_tryrdlock.c
index f59fbbd..fa271fc 100644 (file)
--- 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->__readers);
-       if (rw->__wrlock) {
-               a_dec(&rw->__readers);
-               if (rw->__waiters && !rw->__readers)
-                       __wake(&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;
 }