void pthread_setspecific(pthread_key_t, void *);
void *pthread_getspecific(pthread_key_t);
-void pthread_mutex_init(pthread_mutex_t *, void *attr);
-void pthread_mutex_lock(pthread_mutex_t *);
+int pthread_mutex_init(pthread_mutex_t *, void *attr);
+int pthread_mutex_lock(pthread_mutex_t *);
/* blocking */
-void pthread_mutex_unlock(pthread_mutex_t *);
+int pthread_mutex_unlock(pthread_mutex_t *);
#endif