Method pop

src/bthread/remote_task_queue.h:51–59

    }

    bool pop(bthread_t* task) {
        if (_tasks.empty()) {
            return false;
        }
        _mutex.lock();
        const bool result = _tasks.pop(task);
        _mutex.unlock();
        return result;
    }

    bool push(bthread_t task) {
        _mutex.lock();