Use shutdown for socket on stop with handling ENOTCONN error

[tyler92]

MR #201 wasn't correct. Blocking recv is not interrupted by the close function, only shutdown can interrupt it.

[dakka]

Please provide test cases. This won't be merged as is.

[tyler92]

I am not very familiar with the FIX8 library tests and would be grateful if you could tell me in which of the existing tests this can be added

[tyler92]

OK, I found a way how to reproduce it with f8test target.

1. Change ignore_logon_sequence_check to false in test/myfix_server.xml
2. Desynchronize sequence numbers for the server and the client. We have to get "Message Sequence too low" on the next step.
3. Run the server .libs/f8test -sml server_log
4. Run the client ./f8test -l client_log
5. Observe the error in logs: Net Exception. In fact, it's Net Exception: Socket is not connected (ENOTCONN)

And it's a memory leak:

virtual ~SessionInstance ()
{
    try
    {
        if (_psc != nullptr)
        {
            _psc->stop();  // the exception is occurred here
            delete _psc;   // will never be freed
            _psc = nullptr;
        }
    }
...
    catch (Poco::Exception& e)
    {
        this->_session->log(e.what(), Logger::Error);
    }

[Matoran]

Hi, as you said on #201 an exception on stop will lead to termination due to an exception. You can't throw without changing more code.
Would need to change stop to take a bool can_throw = true, where on connection destructor we call it as stop(false) . Capture every exception log it and throw it only if we can.
Other issue not related to your commit is that in coro mode, _reader.started() is never true, meaning we will never shutdown the socket.

[tyler92]

I will close the MR, it seems nobody is interested in the patch