Programming with .NET - General

Re: Re: Re: Re: Memory leak again

rambler.elf — Thu, 24 Jan 2008 10:25:41 GMT

haughtycool:

However when I add the statement this.Children.Remove(c); at the end of code block, the memory increases when I refresh the page. Is this funny

Idon't know but if your code is something like :

String script = "<Canvas><Image Source=\"bg.jpg\"/></Canvas>";
            Object objApp = XamlReader.Load(script);
            Canvas c = objApp as Canvas;
           for (int i = c.Children.Count - 1; i >= 0; i--)
            {
                Image img = c.Children[ i ] as Image;
                try
                {
                    c.Children.RemoveAt(i);
                    this.Children.Add(img);
                }
                catch (Exception exception)
                {
                    System.Diagnostics.Debug.WriteLine(exception.Message);
                }
            }

            c.Children.Clear();
then this.Children.Remove(c); does not work cos you're not going to add it to the page before removing it!

and if you're adding it to page, there will be no memory leak cos the GC will automatically collects them and this.Children.Remove(c); is unnecessary.

haughtycool:

Thank you. Our discussion is very interesting.

no problems, glad to help you

Re: Re: Re: Re: Memory leak again

haughtycool — Thu, 24 Jan 2008 10:14:39 GMT

However when I add the statement this.Children.Remove(c); at the end of code block, the memory increases when I refresh the page. Is this funny

Thank you. Our discussion is very interesting.

Re: Re: Re: Memory leak again

rambler.elf — Thu, 24 Jan 2008 09:35:24 GMT

Hmmm, I didn't see your code completely and I thought you're removing parent canvas...

I think the problem returns to the silverlight plug-in cos at the end you're calling c.Children.Clear() and in the for statement you're just adding childs so the parent canvas remains in memory(objApp and c pointers) and loaded to the temporary xaml object tree, but if you set c and objApp to null at the end of method, there will be no memory leak so far.(it could be the reason why we see no leak in managed code)

I believe these object which is loaded by XamlReader and are no longer available causes the memory leak...

Re: Re: Re: Memory leak again

haughtycool — Thu, 24 Jan 2008 09:08:12 GMT

Maybe you're right. If I repair the source code as follow, the memory of IE doesn't increase

String script = "<Canvas><Image Source=\"bg.jpg\"/></Canvas>";
            Object objApp = XamlReader.Load(script);
            Canvas c = objApp as Canvas;
           this.Children.Add(c);
            for (int i = c.Children.Count - 1; i >= 0; i--)
            {
                Image img = c.Children[ i ] as Image;
                try
                {
                    c.Children.RemoveAt(i);
                    this.Children.Add(img);
                }
                catch (Exception exception)
                {
                    System.Diagnostics.Debug.WriteLine(exception.Message);
                }
            }

            c.Children.Clear();

Re: Re: Memory leak again

rambler.elf — Thu, 24 Jan 2008 08:53:57 GMT

are you using GC.GetTotalMemory(true) or you're using task manager?

GC.GetTotalMemory returns best available approximation of the number of bytes currently allocated in managed memory. I've tested your case with GC and there was no memory leak on managed code...

but if you're using the task manager, you may see some memory leaks after reloading page continuously; unfortunately, most memory leaks are directly related to the IE garbage collector.

Re: Re: Memory leak again

haughtycool — Thu, 24 Jan 2008 08:23:01 GMT

Yes, when I refresh the page, the memory increases about 7Mb

Re: Memory leak again

rambler.elf — Thu, 24 Jan 2008 08:07:16 GMT

haughtycool:

How about this case. It seems the memory leak

String script = "<Canvas><Image Source=\"bg.jpg\"/></Canvas>";
            Object objApp = XamlReader.Load(script);
            Canvas c = objApp as Canvas;
            for (int i = c.Children.Count - 1; i >= 0; i--)
            {
                Image img = c.Children[ i ] as Image;
                try
                {
                    c.Children.RemoveAt(i);
                    this.Children.Add(img);
                }
                catch (Exception exception)
                {
                    System.Diagnostics.Debug.WriteLine(exception.Message);
                }
            }

            c.Children.Clear();

No, I don't think so, GC works fine in that case, I've tested it and there was no memory leak...

could you tell me why you think there is memory leak in that case?

Re: Memory leak again

mchlSync — Thu, 24 Jan 2008 03:40:09 GMT

haughtycool:
Thank you so much

How come your heart is broken? :P

Re: Memory leak again

haughtycool — Thu, 24 Jan 2008 03:31:19 GMT

How about this case. It seems the memory leak

String script = "<Canvas><Image Source=\"bg.jpg\"/></Canvas>";
            Object objApp = XamlReader.Load(script);
            Canvas c = objApp as Canvas;
            for (int i = c.Children.Count - 1; i >= 0; i--)
            {
                Image img = c.Children[ i ] as Image;
                try
                {
                    c.Children.RemoveAt(i);
                    this.Children.Add(img);
                }
                catch (Exception exception)
                {
                    System.Diagnostics.Debug.WriteLine(exception.Message);
                }
            }

            c.Children.Clear();

Re: Memory leak again

haughtycool — Wed, 23 Jan 2008 06:21:50 GMT

Thank you so much

Re: Memory leak again

rambler.elf — Tue, 22 Jan 2008 20:41:50 GMT

Hi,

That's Simple!, in the first project you've some bugs like changing the collection in your foreach statements which causes an exception, and objects remains in memory for longer time... (you have just to correct them! - did you even tried that for more than one image object!, it doesn't work due to issue mentioned -)

another thing (which doesn't related to the problem) is : if(!(obj is Image)) c.Children.Remove(obj as Visual);// was obj as Image

for the second project just change i<10000 to i<100 (this causes an exception again)

now check with GC.GetTotalMemory - there is no memory leak now...

Memory leak again

haughtycool — Mon, 21 Jan 2008 04:58:08 GMT

I found 2 memory leak case:

1. I created a page which loads and unloads a dynamic resource, when I refresh the page, the memory increase about 7Mb

Please download source code here : http://rapidshare.com/files/85335888/TestContext.zip and give me an advice if you can

2. I create a page which loads and unloads many custom controls, and the memory doesn't decrease when the page unloads the custom control

Please download source code here : http://rapidshare.com/files/85335555/TestContext.rar and give me an advice if you can

PS: You can use Windows Task Manager to monitor the usage memory of the SilverLight page

Thanks for any reply!