I easily reproduced the behavior you described with XXE V2.11, Java 1.4.2_09 on Linux. (I didn't manage to reproduce the problem with V3 and Java 1.5.0_05, which seems faster and more constant in terms of garbage collection.)
After a sequence of close/open, I used Help|About to display memory usage. The Help|About dialog box does a garbage-collection before displaying the memory usage. My analysis is that there is no memory leak here. I think that due to the way XXE works, *transient* out of memory errors may happen when opening a document containing large images. Why do I say that? Because after getting the message "Out of memory" displayed in the document view in red near the ``broken image'' icon, using Select|Redraw caused all the images to be properly displayed again. And after that, Help|About reported that there were still plenty of memory available. In summary, a 1Mb JPEG image has say 1482x1704 pixels. Once uncompressed each pixel uses 4 bytes (RGBA -- or is it 3 bytes: RGB?). This makes 9.63Mb per image. 4 images means 38Mb. To be on the safe side with XXE, you'll need say 2.5*38Mb=95Mb. No, I'm no ashamed to say this, because the workaround is so obvious: * A 1482x1704 pixels is totally unusable on screen: much too large. * Simply adjust the CSS style sheet to display images scaled down (example: CSS style sheet "Images displayed as thumbnails") or define an element template for <imagedata> having for example: scalefit=1, width=50%. With CSS stylesheet "Images displayed as thumbnails", a document which caused XXE to use 36Mb (document data+XXE code+many plug-in code, etc) / 63Mb, now only uses 7Mb/63Mb. Christian K?hrt wrote: > thanks a lot for your fast reply. I will try to explain what I am doing > to provocate the out of memory exception. > > java version: 1.4.2_08 > os: win xp > software to observe the memory of the vm: JProbe > startoptions of xxe: starting without the increase of memory heap and > allocated memory > > workflow: > 1. creating a new docbook article > 2. insert 4 images (jps's around 1mb each) as references in the local > filesystem > 3. save > 4. close the document > .... used memory of vm increased from 4mb to 47mb (after the garbage > collector runs) > 5. open the same document > ... huge increase of used memory again > 6. the first image can be displayed all the others not ... only the > message instead of the image java.lang.outOfMemory > > I can increase the reserved memory by adding the vm options -Xss1m > -Xmx128m but now it is only a question of time when the first out of > memory occured (4 times open - close procedure) > > do you still need the document? its only a docbook article with 4 > figures and this figures are references in the local filesystem and they > are around 1mb sized jpg images. > > the out of memory also occured without using jprobe. > > like mentioned in my first mail we are planing to integrate xxe in > another application and out of memory exceptions are not really funny.
