summaryrefslogblamecommitdiff
path: root/src/thread/pthread_rwlock_unlock.c
blob: 9ae27ad2b3a76c05d4038b291469053bf61f62e2 (plain) (tree)
1
2
3
4
5

                         
                                                 
 
                                                              








                                                                  
                                                 
 

                 

                                                           
#include "pthread_impl.h"

int __pthread_rwlock_unlock(pthread_rwlock_t *rw)
{
	int val, cnt, waiters, new, priv = rw->_rw_shared^128;

	do {
		val = rw->_rw_lock;
		cnt = val & 0x7fffffff;
		waiters = rw->_rw_waiters;
		new = (cnt == 0x7fffffff || cnt == 1) ? 0 : val-1;
	} while (a_cas(&rw->_rw_lock, val, new) != val);

	if (!new && (waiters || val<0))
		__wake(&rw->_rw_lock, cnt, priv);

	return 0;
}

weak_alias(__pthread_rwlock_unlock, pthread_rwlock_unlock);