THRET_FAILURE
pthread_exit(ret ? (void *)THRET_FAILURE : (void *)THRET_SUCCESS);
void *thret = THRET_FAILURE;
void *thret1 = THRET_FAILURE, *thret2 = THRET_FAILURE;
return ((thret1 == THRET_SUCCESS && thret2 == THRET_FAILURE) ||
(thret1 == THRET_FAILURE && thret2 == THRET_SUCCESS))