nsz Git - musl/blob - src/thread/pthread_mutex_timedlock.c

   1 #include "pthread_impl.h"
   2
   3 int pthread_mutex_timedlock(pthread_mutex_t *restrict m, const struct timespec *restrict at)
   4 {
   5         if ((m->_m_type&15) == PTHREAD_MUTEX_NORMAL
   6             && !a_cas(&m->_m_lock, 0, EBUSY))
   7                 return 0;
   8
   9         int r, t, priv = (m->_m_type & 128) ^ 128;
  10
  11         while ((r=pthread_mutex_trylock(m)) == EBUSY) {
  12                 if (!(r=m->_m_lock) || (r&0x40000000)) continue;
  13                 if ((m->_m_type&3) == PTHREAD_MUTEX_ERRORCHECK
  14                  && (r&0x1fffffff) == __pthread_self()->tid)
  15                         return EDEADLK;
  16
  17                 a_inc(&m->_m_waiters);
  18                 t = r | 0x80000000;
  19                 a_cas(&m->_m_lock, r, t);
  20                 r = __timedwait(&m->_m_lock, t, CLOCK_REALTIME, at, 0, 0, priv);
  21                 a_dec(&m->_m_waiters);
  22                 if (r && r != EINTR) break;
  23         }
  24         return r;
  25 }