1#include "pthread_impl.h"
2
3int pthread_rwlock_tryrdlock(pthread_rwlock_t *rw)
4{
5	int val, cnt;
6	do {
7		val = rw->_rw_lock;
8		cnt = val & 0x7fffffff;
9		if (cnt == 0x7fffffff) return EBUSY;
10		if (cnt == 0x7ffffffe) return EAGAIN;
11	} while (a_cas(&rw->_rw_lock, val, val+1) != val);
12	return 0;
13}
14