Re: [flexcoders] Runtime Memory Problems

[slangeberg]

Only after I hit a saturation
point (Around 2.5Meg) would it Garbage Collect. My machine has 2Gig
of Ram.

You're worried about a Flex app using 2.5MB memory? That's nearly nothing.
I've seen apps use upwards of 100M, and that's still not much compared to
2GB.

If you look at the articles online and perhaps posts within this list,
you'll see that there are indeed thresholds within the player, to kick in
garbage collection, but in this instance, i don't see the issue.(?)

-Scott


On 15 Mar 2007 08:41:48 -0700, One Person <[EMAIL PROTECTED]> wrote:

  Description:
We are creating a web-app built with Flex 2.
This app uses some very large image files (From around 256K to over
600K)
We have an image viewer section of our Flex app that will allow the
user to move from one image to another.
I was noticing that with our app in IE7 that memory useage would
climb each time we grabbed a new image but even after letting it set
for several minutes the memory usage would not go down. It was acting
as if Garbage Collection was not getting called. So I added all kinds
of code to make sure that we were letting go of the previous images
to allow Garbage Collection to work.

After 3 days of trying to track down the problem I decided to create
a smaller Flex app that only used our image viewer control to limit
the number of variables in the problem. After a few hours I still
could not figure out the problem so I replace our image view with a
standard <mx:Image> tag. The problem still existed after doing this.
Having take our code out of the picutre I decided to compare results
in FireFox. FireFox would Garbage Collect fairly quickly and the
problem did not seem to exist using my test Flex app in FireFox.

From what I can tell, IE7 and Flash (version 9.0.28.0) do not seem to
work well at allowing Garbage Collection to work.
I have the same version of Flash installed in FireFox 2.0.0.2 and
there does not seem to be any problem there.

The code below is what I used in my mxml file. To test it you will
need to point to some kind of large images that you have access to.
The images that I was using are on an internal network and so are
unavailable to anyone on the outside.

<?xml version="1.0" encoding="utf-8"?>
<mx:Application
layout="absolute"
xmlns:mx="http://www.adobe.com/2006/mxml";
initialize="init()"
>
<mx:Script>
<![CDATA[

public var urls:Array = new Array();
public var index:int = 0;
[Bindable] public var tempUrl:String;

private function init() : void
{
urls.push( "http://10.7.2.8/07026/07026_00115.jpg"; );
urls.push( "http://10.7.2.8/07026/07026_00116.jpg"; );
urls.push( "http://10.7.2.8/07026/07026_00117.jpg"; );
urls.push( "http://10.7.2.8/07026/07026_00118.jpg"; );
urls.push( "http://10.7.2.8/07026/07026_00119.jpg"; );
urls.push( "http://10.7.2.8/07751/07751_00473.jpg"; );
urls.push( "http://10.7.2.8/07751/07751_00474.jpg"; );
urls.push( "http://10.7.2.8/07751/07751_00475.jpg"; );
urls.push( "http://10.7.2.8/07751/07751_00476.jpg"; );
urls.push( "http://10.7.2.8/07751/07751_00477.jpg"; );
urls.push( "http://10.7.2.8/07751/07751_00478.jpg"; );
urls.push( "http://10.7.2.8/07751/07751_00479.jpg"; );
urls.push( "http://10.7.2.8/42401/42401_00000000.JPG"; );
urls.push( "http://10.7.2.8/42401/42401_00000002.JPG"; );
urls.push( "http://10.7.2.8/42401/42401_00000003.JPG"; );
urls.push( "http://10.7.2.8/42401/42401_00000004.JPG"; );
urls.push( "http://10.7.2.8/42401/42401_00000005.JPG"; );
urls.push( "http://10.7.2.8/42401/42401_00000006.JPG"; );
urls.push( "http://10.7.2.8/42401/42401_00000007.JPG"; );
urls.push( "http://10.7.2.8/42401/42401_00000008.JPG"; );
index = 0;
setCurrentIndex();
}

private function setCurrentIndex() : void
{
img.source = urls[index];
}

private function previous_Click() : void
{
if( --index < 0 )
{
index = urls.length-1;
}

setCurrentIndex();
}

private function next_Click() : void
{
if( ++index >= urls.length )
{
index = 0;
}

setCurrentIndex();
}
]]>
</mx:Script>
<mx:Grid width="100%" height="100%">
<mx:GridRow width="100%" height="30">
<mx:GridItem width="100%" height="100%">
<mx:Button label="&lt;" click="previous_Click()"/>
<mx:Button label="&gt;" click="next_Click()"/>
</mx:GridItem>
</mx:GridRow>
<mx:GridRow width="100%" height="100%">
<mx:GridItem width="100%" height="100%">
<mx:Image id="img" source="{tempUrl}" width="100%"
height="100%"/>
</mx:GridItem>
</mx:GridRow>
</mx:Grid>
</mx:Application>

I can't find a way to post my images so I hope this description is
good enough.

In IE7 the memory would climb each time I would move to the next
image. On the left of this graph I loaded several images and then let
IE7 sit. After a few minutes, and memory staying where it was, I
continued click next to load images. Only after I hit a saturation
point (Around 2.5Meg) would it Garbage Collect. My machine has 2Gig
of Ram.

The next rise in the graph is where I kept loading images over and
over until the memory usage was about the same as just before the
garbage collection happened the previous time. I let that sit for a
while and then tried to load one more image. That caused the garbage
collection to happen.

The next 4 peaks in the graph are where I basicly clicked on the next
button over and over as fast as I could and the Garbage Collection
seemed to happen a little more often.

In FireFox I ran similar tests of loading images and waiting in
FireFox. The Garbage Collection seems to be working fairly well here.
Each time I would load a new image the previous one would be cleaned
up with garbage collection.

So I'm not sure what can be done or if there is a fix for this. I
really would LOVE to have access to the Garbage Collection in Flash
so I could force things to happen when I am dumping a real large
image.

Thanks,
Mike Collins

--

: : ) Scott