Question

So, i have a CSocket listening in a worker thread, it would do a blocking accept and then spin another thread (yea, i know perfermance not a issue) for each new connection.

How one is supposed stop listen?
You cannot call it close from another thread because the CSocket will trown an assert.

Any quick fix or just throw away this terribile badly designed wrapper?

Answer 1

From MSDN:

If you want to handle this connection in a different thread, just
passing the MFC object to the thread will not work correctly. To
correctly set up everything for the connection to be handled in a
different thread, the following steps are required:

1. Detach the socket handle from the CAsyncSocket object in the thread where the connection was accepted.
2. Pass the socket handle to the thread.
3. In the thread, attach this handle to a CAsyncSocket derived object.

If you are creating a performance critical program, I’d personally use IOCP.

The code is going to look similar to:

Accept(ClientSocketObject, ... );
SOCKET s = ClientSocketObject.Detach();
CreateThread( ... ,(LPVOID)s, ...);

In your thread procedure,

ThreadProc( SOCKET s ){
CAsyncSocket clientSocket;
clientSocket.Attach( s );