getaddrinfo: add EAI_NODATA error code to distinguish NODATA vs NxDomain
[musl] / src / thread / pthread_rwlock_timedwrlock.c
index 9682774..d77706e 100644 (file)
@@ -1,17 +1,25 @@
 #include "pthread_impl.h"
 
-int pthread_rwlock_timedwrlock(pthread_rwlock_t *rw, const struct timespec *at)
+int __pthread_rwlock_timedwrlock(pthread_rwlock_t *restrict rw, const struct timespec *restrict at)
 {
-       int nr, *p, w=0;
-       while (pthread_rwlock_trywrlock(rw)==EAGAIN) {
-               if (!w) a_inc(&rw->_rw_waiters), w++;
-               if ((nr=rw->_rw_readers)) p = &rw->_rw_readers;
-               else nr=1, p = &rw->_rw_wrlock;
-               if (__timedwait(p, nr, CLOCK_REALTIME, at, 0)==ETIMEDOUT) {
-                       if (w) a_dec(&rw->_rw_waiters);
-                       return ETIMEDOUT;
-               }
+       int r, t;
+       
+       r = pthread_rwlock_trywrlock(rw);
+       if (r != EBUSY) return r;
+       
+       int spins = 100;
+       while (spins-- && rw->_rw_lock && !rw->_rw_waiters) a_spin();
+
+       while ((r=__pthread_rwlock_trywrlock(rw))==EBUSY) {
+               if (!(r=rw->_rw_lock)) continue;
+               t = r | 0x80000000;
+               a_inc(&rw->_rw_waiters);
+               a_cas(&rw->_rw_lock, r, t);
+               r = __timedwait(&rw->_rw_lock, t, CLOCK_REALTIME, at, rw->_rw_shared^128);
+               a_dec(&rw->_rw_waiters);
+               if (r && r != EINTR) return r;
        }
-       if (w) a_dec(&rw->_rw_waiters);
-       return 0;
+       return r;
 }
+
+weak_alias(__pthread_rwlock_timedwrlock, pthread_rwlock_timedwrlock);