reorganize pthread data structures and move the definitions to alltypes.h

[musl] / src / thread / pthread_rwlock_trywrlock.c

#include "pthread_impl.h"

int pthread_rwlock_trywrlock(pthread_rwlock_t *rw)
{
        if (a_xchg(&rw->_rw_wrlock, 1))
                return EAGAIN;
        if (rw->_rw_readers) {
                a_store(&rw->_rw_wrlock, 0);
                return EAGAIN;
        }
        rw->_rw_owner = pthread_self()->tid;
        return 0;
}