c# - 超时的 API 设计 : TimeoutException or boolean return with out parameter?

Question

场景是消息队列上的 RPC - 由于底层机制是异步的，客户端应该指定他们希望在超时前等待响应的时间。作为客户，您更愿意使用这两个代码片段中的哪一个？

最重要的是:作为 GetResponseTo() 方法的用户，为什么您更喜欢其中一种方法？您的选择如何使您的代码更具可扩展性、可读性、可测试性等？

try
{
    IEvent response = _eventMgr.GetResponseTo(myRequest, myTimeSpan);
    // I have my response!
}
catch(TimeoutException te)
{
    // I didn't get a response to 'myRequest' within 'myTimeSpan'
}

或

IEvent myResponse = null;

if (_eventMgr.GetResponseTo(myRequest, myTimeSpan, out myResponse)
{
    // I got a response!
}
else
{
    // I didn't get a response... :(
}

供您引用，这是 GetResponseTo() 的当前实现:

public IEvent GetResponseTo(IEvent request, TimeSpan timeout)
{
    if (null == request) { throw new ArgumentNullException("request"); }

    // create an interceptor for the request
    IEventInterceptor interceptor = new EventInterceptor(request, timeout);

    // tell the dispatcher to watch for a response to this request
    _eventDispatcher.AddInterceptor(interceptor);

    // send the request
    _queueManager.SendRequest(request);

    // block this thread while we wait for a response.  If the timeout elapses,
    // this will throw a TimeoutException
    interceptor.WaitForResponse();

    // return the intercepted response
    return interceptor.Response;
}

Answer 1

无论是第一个还是第二个，我都想使用 Task Parallel Library ，这是从 .NET 4.5 开始推荐的所有异步处理方式:

Task<IEvent> task = _eventMgr.GetResponseToAsync(myRequest);

if (task.Wait(myTimeSpan))
{
    // I got a response!
}
else
{
    // I didn't get a response... :(
}