- pthread_mutexattr_init(&attr);
- pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_DEFAULT);
- pthread_mutex_init(&queue->mutex, &attr);
+ assert(pthread_mutexattr_init(&attr) == 0);
+ assert(pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_DEFAULT) == 0);
+ assert(pthread_mutex_init(&queue->mutex, &attr) == 0);