src/thread/pthread_rwlock_timedrdlock.c

   1 #include "pthread_impl.h"
   2
   3 int __pthread_rwlock_timedrdlock(pthread_rwlock_t *restrict rw, const struct timespec *restrict at)
   4 {
   5         int r, t;
   6
   7         r = pthread_rwlock_tryrdlock(rw);
   8         if (r != EBUSY) return r;
   9
  10         int spins = 100;
  11         while (spins-- && rw->_rw_lock && !rw->_rw_waiters) a_spin();
  12
  13         while ((r=__pthread_rwlock_tryrdlock(rw))==EBUSY) {
  14                 if (!(r=rw->_rw_lock) || (r&0x7fffffff)!=0x7fffffff) continue;
  15                 t = r | 0x80000000;
  16                 a_inc(&rw->_rw_waiters);
  17                 a_cas(&rw->_rw_lock, r, t);
  18                 r = __timedwait(&rw->_rw_lock, t, CLOCK_REALTIME, at, rw->_rw_shared^128);
  19                 a_dec(&rw->_rw_waiters);
  20                 if (r && r != EINTR) return r;
  21         }
  22         return r;
  23 }
  24
  25 weak_alias(__pthread_rwlock_timedrdlock, pthread_rwlock_timedrdlock);