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分享急:CSOCKET中TCP连接,服务端如何马上知道客户端已断开,为什么onclose()不行?
急:CSOCKET中TCP连接,服务端如何马上知道客户端已断开,为什么onclose()不行?
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formoney 2002-05-08
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very good
acptvc 2002-05-06
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If the client disconnects the connection gracefully by calling closesocket or shutdown API, the onclose event will be activated. However, if the network disconnectes because of physical problem, for example, network line and OS shuts down, the onclose will not be notified.
Therefore, there is no method to detect the physical disconnection of a network. There is also no method to detect the program down of the opposite side.
However there are 2 ways.
The first way: you need to set SO_KEEPALIVE by setsockopt API.
Please refer to the following article:
Q140325 How to Determine Loss of Client/Server Connection
http://support.microsoft.com/support/kb/articles/q140/3/25.asp
The other way: you can sets a socket as a non-block in the program, and implement TIMEOUT by select(). If the opposite side does not respond for a certain time, we should assume the opposite side is down and close by close().
CSDN
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本贴子以“现状”提供且没有任何担保，同时也没有授予任何权利。具体事项可参见使用条款(http://support.microsoft.com/directory/worldwide/zh-cn/community/terms_chs.asp)。
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Therefore, there is no method to detect the physical disconnection of a network. There is also no method to detect the program down of the opposite side.
However there are 2 ways.
The first way: you need to set SO_KEEPALIVE by setsockopt API.
Please refer to the following article:
Q140325 How to Determine Loss of Client/Server Connection
http://support.microsoft.com/support/kb/articles/q140/3/25.asp
The other way: you can sets a socket as a non-block in the program, and implement TIMEOUT by select(). If the opposite side does not respond for a certain time, we should assume the opposite side is down and close by close().
CSDN
======================
- 微软全球技术中心 <display name>
本贴子以“现状”提供且没有任何担保，同时也没有授予任何权利。具体事项可参见使用条款(http://support.microsoft.com/directory/worldwide/zh-cn/community/terms_chs.asp)。
为了为您创建更好的讨论环境，请参加我们的用户满意度调查(http://support.microsoft.com/directory/worldwide/zh-cn/community/survey.asp?key=(S,49854782))。
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MFC中封装的socket 直接就有事件回调，就不需要我们自己去轮询 自己去处理，我们只需要写好对于的事件回调函数即可，系统帮我们进行调用 方便了很多，而且 不需要多线程就可以实现 单个TCP服...
