[SOLVED]Problem when using second socket.

ealione

I have created a multithreaded html server that can receive and send data, including images and other files. I wanted to add the ability to send messages so I created a different library that connects to a host (e.g. smtp.google.com) and acts as a simple smtp client

socket->connectToHost(host, port);

and after logging in it writes my message

socket->write(text.toUtf8() + "\r\n");

If I test this on its own it works as expected and all messages get send.

After invoking this from my server though I get an error.

The server listens for traffic using another socket. When a user connects and visits a link for example I try to use my smtp client to send an email only to get this error

QIODevice::write: device not open

mcosta

Sorry,

can you post the code that is not working??
Do you wait for connected() signal before using write()?

ealione

Yes I do wait for the socket to connect using

if (!socket->waitForConnected(connectionTimeout))
{
    return false;
}

And its hard to post the code as it has turned out to be quite lengthy. Yet my smtp client is a barebones version of this . Any changes that I have made could not be responsible as the way I connect and send the data is the same, and as I said it works fine by itself. As for the http server it contains a worker class that deals with sockets (moves them into a separate thread, connects to the host etc) and a tcpServer that uses the worker class in order to deal with multiple connections.

mcosta

Is write() called just after that??

ealione

No after that I wait for the smtp server to respond using

waitForResponse();

after that I follow with all the procedure that has to take place in order to communicate with an smtp server, like sending the EHLO/HELO message

socket->write(text.toUtf8() + "\r\n");
if (! socket->waitForBytesWritten(sendMessageTimeout))
{
  throw SendMessageTimeoutException();
}

mcosta

Seems that socket is not connected when you use write().
I suggest to handle the QAbstractSocket::stateChanged() signal to understand when the state changes after connection

ealione

I did and it seems that it never changes state. I do not even connect with smtp.google when I use this class form inside my http server, which is weird as it connects just fine otherwise.

mcosta

Are you sure your socket is not changed is some part in the code??

ealione

Yup you are correct I should have looked more carefully at my implementation. I had a placed an ! symbol incorrectly. Now as you suggested I can see the states. This is what I get

Sending verification email.
QAbstractSocket::HostLookupState
QAbstractSocket::ConnectingState
QAbstractSocket::ConnectedState
Failed to connect to host!

The last comment comes from

smtp.connectToHost()

Seems that it returns false, but at least this is a step forward.

mcosta

Are you sure you don't need to have a SSL socket?? I think at least smtp.gmail.com requires it

ealione

Yup that was it. Realised it just before I read your comment.
I am marking this as solved, thanks for the help mcosta.

mcosta

You're welcome