Parallel.For loop unit test crashes VsTestHost

Question

 

this is an example of a small unit test which runs a Parallel.For loop 200,000 times.  many times this unit test causes VsTestHost to crash.  we are having this problem in our project and have narrowed the problem down to this example.  I can send or attach a small project if desired.

 

using System;

using System.Text;

using System.Collections.Generic;

using System.Linq;

using Microsoft.VisualStudio.TestTools.UnitTesting;

using System.Threading;

namespace ParallelCrashTest

{

/// <summary>

/// Summary description for ParallelCrash

/// </summary>

[TestClass]

public class ParallelCrash

{

[TestMethod]

public void ParrelCrashTest()

{

for (int x = 0; x < 200000; x++)

{

Parallel.For(0, 9, delegate(int y)

{

});

}

}

}

}

Answer 1

Thanks for the bug report.  This is a known issue with the CTP bits having to do with aborting worker threads, and we haven't made a fix available publicly.  As a workaround, you could try adding the following code to your unit test project:

 

Code Snippet

static void UnitTestWorkaround(Action a)

{

    using (var tm = new TaskManager())

        Task.Create(delegate { a(); }, tm).Wait();

}

 

Then instead of the code you currently have, you could surround it with a call to UnitTestWorkaround, where the delegate passed to UnitTestWorkaround includes your code, e.g.:

 

Code Snippet

[TestMethod]

public void ParrelCrashTest()

{

    UnitTestWorkaround(() => {

 

    for (int x = 0; x < 200000; x++)

    {

        Parallel.For(0, 9, delegate(int y)

        {

        });

    }

 

    });

}

 

Please let me know if this "fixes" (or doesn't) the problem for you.

 

 

 

 

 

Answer 2

It works for me! Thank you.