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Re: Problem with websocket connect method [message #49012 is a reply to message #48954]

Sat, 25 November 2017 13:58

Oblivion
Messages: 1093
Registered: August 2007

Senior Contributor

Hello,

I found the problem with connection.
It turned out that

1) IpAddrInfo::Start() is not called (WebSocket.cpp, ln. 94-5.

		if(!ipaddrinfo.Execute(host, port)) {
			Error("Not found");
			return false;
		}
		LLOG("DNS resolved");
		StartConnect();
		while(opcode != READING_FRAME_HEADER) {
			Do0();
			if(IsError())
				return false;
		}
	}
	else {
		opcode = DNS;
		ipaddrinfo.Start(host, port); // <-- Was missing.
	}
	return true;

2) In Do0(), socket is checked for Eof too early (It should be checked after DNS phase, WebSocket, ln. 345-6).

		prev_opcode = opcode;
		if(opcode != DNS)
			if(socket->IsEof() && !(close_sent || close_received))
				Error("Socket has been closed unexpectedly");

3) I also changed addrinfo to ipaddrinfo to avoid any nameclashes and errors (there is already an "addrinfo" structure)
4) A suggestion: We should check for DNS lookup errors too:


void WebSocket::Dns()
{
	if(ipaddrinfo.InProgress())
		return;
        if(!ipaddrinfo.GetResult()) {                         // We should check for lookup errors...
               Error("DNS lookup failed");                   //
               return;
        }
	LLOG("DNS resolved");
	StartConnect();
}

5) Aonther suggestion: I still think that WebSocket::Do() should return a boolean value to indicate progress/finish. I couldn't find a reliable way to check if a non-blocking operation such as Connect() is successful. Currently the only way to break the loop of a non-blocking Connect() call seems to be to check for errors.

From my experience I can say that below code (or other variants of this) would work well on such situations:


    ws.NonBlocking().Connect("127.0.0.1:12321");
    while(ws.Do())
        ;
    if(ws.IsError())
       return;

    // Success, carry on (send/recv)...

You can find the patched files below.

Best regards,
Oblivion

Attachment: WebSocketPatched.zip
(Size: 9.78KB, Downloaded 223 times)

Github page: https://github.com/ismail-yilmaz
upp-components: https://github.com/ismail-yilmaz/upp-components
Bobcat the terminal emulator: https://github.com/ismail-yilmaz/Bobcat

[Updated on: Sat, 25 November 2017 22:47]

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