github.com/afumu/libc@v0.0.6/musl/src/thread/pthread_rwlock_timedrdlock.c (about)

     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);