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CAsyncSocket and broken network cable

mike_marquet asked
Medium Priority
Last Modified: 2013-11-20
I have created a client/server application using CAsyncSocket class.
It works very fine. But my question is :

1°) I make a connection to the server side.
2°) When the connection is establish, I 'cut' the physical network cable.
3°) How can these applications know that the connection is broken ?

Because when I send a packet to the other side (with CAsyncSocket::Send), the function
returns OK, send succefull.

How to know it ?

Thanks for response
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But there is an other error, when I send my data, the OnSend handler is never posted !
But the remote computer has received the datas.
I become an OnSend data the first time the socket is connected to remote computer and that of both side.
Why ?

Must I set an option some where, and if yes where ?


I don't understand.  How can your remote computer receive the data if you've cut the network cable?  Please explain.

I don't understand.  How can your remote computer receive the data if you've cut the network cable?  Please explain.

You haven't posted any code but, in order to use the OnSend virtual function of CAsyncSocket, you must derive your own class from CAsyncSocket so that you can define your own OnSend class.  You then would add an instance of myCAsyncSocket to your application and it's OnSend member function would get called.

BTW, is there a particular reason why you are using CAsyncSocket instead of CSocket?  I find that it's often easier to use the blocking CSocket calls and put them in a thread and then use WaitforSingleObject on the thread than to manage CAsyncSocket callback messages.  It gives you greater control over what you are waiting for.  If you put your Send in a thread, the call will hang until the data is sent.  Now your WaitForSingleObject can wait on the thread until it completes or your timeout happens.  If a timeout occurs, you can assume the network is down and cancel the send operation and recover grecefully.


When the cable is broken, the send function says that he has send data succefully.
It seams that the socket hasn't sea that the connection is broken.
He sends the data, but I never became an error ? (such as OnSend with error code).

When I says I using CAsyncSocket, I meen that I have derived from this class.
Replace all CAsyncSocket by CMyAsyncSocket.

I'm using CAsyncSocket for the callbacks functions and for non blocking socket.

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