Question

I’m getting a stream from HttpWebResponse.GetResponseStream() where I’m reading data from.
Now I want to implement a Timeout property. The easiest way to do it would be stream.ReadTimeout = timeout but this throws an InvalidOperationException -> Timeouts are not supported on this stream.

Given this, I’m trying to implement the timeout property myself but got stuck on a dispose. This is what I got so far:

public class MyStream : Stream {
    private readonly Stream _src;
    public override int ReadTimeout { get; set; }

    public MyStream (Stream src, int timeout) {
       ReadTimeout = timeout;
       _src = src;
    }

    public override int Read(byte[] buffer, int offset, int count) {
        var timer = new AutoResetEvent(false);
        int read = 0;

        ThreadPool.QueueUserWorkItem(
            _ => {
                read = _src.Read(buffer, offset, count);
                timer.Set();
            });
        bool completed = timer.WaitOne(ReadTimeout);
        if (completed) {
            return read;
        }
        throw new TimeoutException(string.Format("waited {0} miliseconds", ReadTimeout));
    }

The problem with this code is after is throws a TimeoutException that is being properly handled somewhere. It throws an Exception on _src.Read(buffer, offset, count) saying that the _src stream was disposed.

Is there a way to cancel the ThreadPool method or should I use a better approach and which one?

Thanks

EDIT

As asked by @JotaBe, were’s the code where I get the stream from HttpWebResponse:

_httpRequest = WebRequest.CreateHttp(url);

_httpRequest.AllowReadStreamBuffering = false;
_httpRequest.BeginGetResponse(
    result =>
        {
            try {
                _httpResponse = (HttpWebResponse)_httpRequest.EndGetResponse(result);
                stream = _httpResponse.GetResponseStream();
            }
            catch (WebException) {
                downloadCompleted.Set();
                Abort();
            }
            finally {
                downloadCompleted.Set();
            }
        },
        null);

    bool completed = downloadCompleted.WaitOne(15 * 1000);
    if (completed) {
        return new MyStream(stream, 10000);
    }

Answer 1

I ended up using Nomad101 suggestion and surround the read with a try/catch.