There is also a trick to recreating large objects which
could influence your app:
The code:
BufferedImage img;
while (true) {
img = new BufferedImage(w, h, type);
}
will use up more memory in general than the following:
BufferedImage img;
while (true) {
img = null;
img = new BufferedImage(w, h, type);
}
The problem with the first approach is the old img is
still alive (and therefore sitting in the heap) when
the new image is created, so the allocator must find room
for the new one without removing the old one.
In the second example, the reference is first removed, so
when the allocator goes to find enough heap space for the
new image it is allowed to scavenge the memory from the
old image first.
I don't know if this is at the root of your problem, but
I thought it was worth pointing out.
Chet.
Chris Campbell wrote:
>
> Hi Nick,
>
> In general it's best to avoid recreating BufferedImages in an animation
> loop, but it sounds like you only do it when necessary, which is okay.
> I'm interested to see why you need to make a larger BufferedImage when
> you "zoom in". If you send me a small testcase that reproduces the
> problem I'd be happy to take a look at it.
>
> Thanks,
> Chris
>
> Nick Collier wrote:
> > Hi,
> >
> > I think I'm seeing a problem with creating BufferedImage-s and memory
> > use. To over simplify a bit I'm using one to draw on as part of some
> > animation. Sometimes I need to recreate it when I've zoomed in (the
> > BufferedImage needs to become bigger). If I do this enough I eventually
> > I get an OutOfMemoryError when I try to create the new BufferedImage.
> > The amount of allocated memory should easily be enough to hold the
> > largest BufferedImage I need so the problem is not with the size of a
> > single BufferedImage. I don't have any extraneous references to this
> > BufferedImage and so the memory should be reclaimed I think. It doesn't
> > appear to be though. I've come up with a work around that eliminates the
> > need to recreate the BufferedImage, but I'm still puzzled as to why this
> > should ever occur, especially as it occurs much more frequently on Win2K
> > than on Linux.
> >
> > I've tried looking in the bug database but it seems to be down.
> >
> > Any comments appreciated,
> >
> > Nick
> >
> > --
> > Nick Collier
> > Social Science Research Computing
> > University of Chicago
> > http://repast.sourceforge.net
> >
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> --
> Chris Campbell 408-276-6429
> [EMAIL PROTECTED] x16429
> Sun Microsystems, Java 2D USCA22-212
>
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