G120 Debug.GC(true)

Archive
1

I’m running a graphic intense app on the Cobra II and I’ve found calling Debug.GC(true) can cause the system to hang or even reboot.

Known issue?

2

One way to check is to try it on another Cobra II :wink:

3

That is no good! No this is not a known issue. Please provide a test example.

4

Trying to find a way to give a good test.

I’ve found there’s one specific area that causes Debug.GC to fail. Outside of the method, it works. Now I just need to narrow down what’s breaking it so I can cut the code down (big graphics = big code) for you guys.

5

I am really hoping this is a coincidence and the problem is not GC! We are waiting for more details.

6

Definitely not a coincidence. I can break it over and over by putting Debug.GC(true) inside of this method and it will work everytime if I omit that line.

FOUND IT!

The problem is calling Debug.GC(true); while you have a ManualResetEvent going.

Here’s a way to make it fail every time.

        static ManualResetEvent _activeBlock = null;
        static void IWillAlwaysFail()
        {
            Debug.Print("Starting failure method...");

            _activeBlock = new ManualResetEvent(false); 
            Debug.Print("ManualResetEvent Created");

            new Thread(ICauseTheFailure).Start();

            // Wait for Result
            _activeBlock.Reset();
            while (!_activeBlock.WaitOne(1000, false))
                ;

            // Unblock
            _activeBlock = null;

        }

        static void ICauseTheFailure()
        {
            Thread.Sleep(3000);
            Debug.Print("About to force a failure...");
            Debug.GC(true);
            Debug.Print("I'll never get here...");
            _activeBlock.Set();
        }

        public static void Main()
        {
            IWillAlwaysFail();
        }
7

Ttried it on my Cobra II it hanged as you have described.

8

Look at this thread,

http://www.tinyclr.com/forum/topic?id=9876

9

Looks like related issue and the fix is already exists! Good catch!

10

This is great. I was worried this will be a difficult fix but it is fixed already :slight_smile:

11

That is a relief. :slight_smile:

12

Wow, do you have an index of the entire forum? :slight_smile: It is unbelievable how often you remember that there was a related issue!! We should replace the forum search with @ Architect.

13

@ taylorza - I read that thread before, but I forgot about it.

It is @ Honken who pointed that out.

14

Ah, I missed his post… :slight_smile: