Re: [JAVA2D] memory limit problems with Java and System.gc()

[James Carroll]

Title: Re: [JAVA2D] memory limit problems with Java and System.gc()

 

I second this.  Using JProbe (back when it was affordable) really saved

my project... it's a lot easier than you might think to hold on to references to memory that

you think you're getting rid of.  Now I'm also in the habit of calling dispose() on any bitmaps

that I'm finished with, and making sure that any MediaTrackers have their images removed

after they're done tracking, etc...   (My worst problems were on Mac Java 1.3, but doing

these things will make code run smoother on all platforms.)

 

OptimizeIt is what I would use today.

 

-Jim

 

---

From: Discussion list for Java 2D API [mailto:[EMAIL PROTECTED] On Behalf Of David Kavanagh
Sent: Tuesday, July 20, 2004 11:17 AM
To: [EMAIL PROTECTED]
Subject: Re: [JAVA2D] memory limit problems with Java and System.gc()

I've done apps that use Java2D and cycle through large amounts of memory. We
even had one running on a large Sun server with 2G allocated to it and it was
stable over the long run. That was with 1.3.1, and things have improved with
1.4.x. I recommend reading some of the documentation found here;
http://java.sun.com/docs/hotspot/index.html
In general, if you configure the JVM correctly, you shouldn't need to call
System.gc() ever.
If you still have problems, try something like JProbe or OptiimizeIt to fine the
source of your memory problems. If you have references to these strings, those
tools can find them!

Best of luck,
David

Quoting Sven Mielordt <[EMAIL PROTECTED]>:

> Dear David,
>
> thank you for the advice concerning memory mapped files. Though this are
> interesting topics, the ideas do not solve my problem. The memory leaks occur
> due to extensive formation of strings, arrays of strings and other objects,
> but not from file accession.
>
> The problem is to free the memory occupied by objects that are no longer
> needed; obviously, the invocation of System.gc() does not really help.
>
> Perhaps this problem is hard to solve in Java? I need a mechanism that is
> similar to the concept of a C++ destructor or something like
> Graphics.dispose() but suited for instances of any class. Doesnt there exist
> something stronger then just to rely on the garbage collection?
>
> Another thing that would help is to overcome the daunting 1GB RAM limit for
> java when calling the virtual machine with the Xmx attribute. Is there a
> trick to make the whole 2GB RAM available to Java?
>
> Sorry for repeated questioning,
> Sven
>
>
> "Rosenstrauch, David" <[EMAIL PROTECTED]> schrieb am 20.07.04
> 15:31:58:
> >
> >
> >
> > > -----Original Message-----
> > > From: Sven Mielordt [mailto:[EMAIL PROTECTED]]
> > > Sent: Tuesday, July 20, 2004 9:14 AM
> > > To: Rosenstrauch, David
> > > Subject: Re: [JAVA2D] memory problems with Java and System.gc()
> > >
> > >
> > > That sounds nice, how can I use them and what Java version is needed?
> >
> >
> > As of JDK1.4, it looks like.
> >
> > Start with these:
> >
> > http://www.developer.com/java/other/article.php/1548681
> > http://javaalmanac.com/egs/java.nio/CreateMemMap.html?l=rel
> >
> > I'm sure you can google up some other references from there.
> >
> > DR
> >
> >
>
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