Bug 22717 - Process hangs if there is a socket operation going on
Summary: Process hangs if there is a socket operation going on
Alias: None
Product: Class Libraries
Classification: Mono
Component: System ()
Version: 3.4.0
Hardware: PC Linux
: --- normal
Target Milestone: Untriaged
Assignee: Ludovic Henry
Depends on:
Reported: 2014-09-06 05:59 UTC by Tudor Simionescu
Modified: 2017-02-08 20:22 UTC (History)
2 users (show)

Is this bug a regression?: ---
Last known good build:

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Description Tudor Simionescu 2014-09-06 05:59:34 UTC
The following program never finishes when run on mono 3.4.0 on Linux (CentOS) (also on mono 3.2.0 on Windows). I have also reproduced it using the csharp REPL. The problem reproduces almost always, though small changes in the program prevent it from happening. If it is not reproducing on your machine, try adding some wait time between creating the thread that tries to accept a connection, and the call to Environment.Exit.

The problem never reproduces if run on the CLR on windows. I also wasn't able to reproduce on mac with mono 3.8.0, but I didn't get a chance to try changing the timing.

using System;
using System.Net;
using System.Net.Sockets;
using System.Threading;

namespace Example
    class Program
        static void Main(string[] args)
            var s = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.IP);
            Console.WriteLine("Socket created");

            s.Bind(new IPEndPoint(new IPAddress(new byte[] { 127, 0, 0, 1 }), 12345));
            Console.WriteLine("Socket bound");            

            new Thread(() => s.Accept()).Start();
            //On windows it also reproduces if you replace 
            //the previous line with a call to 
            //s.AcceptAsync(new SocketAsyncEventArgs())

            Console.WriteLine("Exiting...");//the problem may not reproduce without this, it's probably timing dependent
Comment 1 Ludovic Henry 2017-02-08 20:22:04 UTC
I cannot reproduce with latest mono: Mono JIT compiler version 4.8.0 (mono-4.8.0-branch/6100225 Thu Jan 12 11:37:51 EST 2017)

Please reopen the bug if you can still witness it.