CODEWITHSUNDEEP
c#serial-port
Bildsoe
Bildsoe

Reputation: 1350

How do I properly close serial port connection and thread it runs in?

I have an serial port read running on a background thread, but everytime I try to close it, I get an exception. Usually an IO-exception.

It is as if the read continues on eventhough I close the thread.

This is my current code:

EDIT: I changed the code, removed the checks on threatstate.

public bool Connect(string portName)
    {
        try
        {
            sp = new SerialPort(portName, BaudRate);
            sp.Open();
            sp.DtrEnable = true;

             cf = SingletonFormProvider.GetInstance<ConnectionForm>(null);

            _continue = true;
            readThread = new Thread(Read);
            readThread.Start();

            return true;
        }
        catch(Exception ex)
        { 
            MessageBox.Show(ex.Message);

            return false;
        }
    }

    public void Disconnect()
    {

        if (IsConnectionOpen)
        {
            _continue = false;
            readThread.Abort();

            while (readThread.ThreadState == ThreadState.AbortRequested)
            { }

            sp.Close();

            readThread.Join();
        }

    }

    private void Read()
    {

                while (_continue)
                {
                    try
                    {
                        string message = sp.ReadLine();
                        cf.WriteLog(message);
                    }
                    catch (Exception ex)
                    {

                            MessageBox.Show(ex.Message);
                            _continue = false;
                            readThread.Join();
                            sp.Close();

                    }

            }


    }

Upvotes: 1

Views: 3258

Answers (2)

Tim
Tim

Reputation: 1286

Join your read thread before you close the serial port:

public void Disconnect()
{

    if (IsConnectionOpen)
    {
        _continue = false;

        readThread.Join();
        sp.Close();
    }
}

Upvotes: 0

500 - Internal Server Error
500 - Internal Server Error

Reputation: 28839

You do know that what thread.Abort() does is throw a ThreadAbortException in the thread in question, right? In the thread you catch all exceptions that inherited from Exception. I believe that includes the abort exception. If you really must call Abort, you may want to close the serial port first since I believe that will cause any pending calls to return.

Upvotes: 2

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