Method wait

example/cpp14/executors/actor.cpp:190–197

Block until a message has been received.

  // Block until a message has been received.
  Message wait()
  {
    std::unique_lock<std::mutex> lock(mutex_);
    condition_.wait(lock, [this]{ return !message_queue_.empty(); });
    Message msg(std::move(message_queue_.front()));
    message_queue_.pop_front();
    return msg;
  }

private:
  // Handle a new message by adding it to the queue and waking a waiter.