Memory leak in 1.5.0 JVM

[Mika Nystrom]

No, that does seem to fix it, also.  Of course, I have no idea how
many times slower System.gc() is than thread.start()...

Out-running the garbage collector?  I'm not used to Java, but in
Modula-3, the garbage collector gets called when you allocate memory,
is that not how it works in Java?

Hmmm...!

I am testing this code because I am having some trouble with a
long-running server, which spaws a few new threads every two seconds
using Quartz, and I can't for the life of me see why its memory
usage is growing over time (it runs out of its 300 megs after about
two hours).  But it could be something completely different in that
program, of course.

    Mika

class Leakq {

  private static class MyThread extends Thread {
    public void run()
    {

    }
  }

  public static void main (String[] args)
  {
    for(;;) {
      Thread  t = new MyThread();
      t.start();
      /*try { t.join(); } catch (Exception ex) { ; }*/
      System.gc();
    }
  }
}


"Samuel R. Baskinger" writes:
>
>Do you get the same results if you put a System.gc() after your thread spawn? Perhaps you are just out-running the garbage collector. :)
>
>I tried this on the diablog-jdk 1.5 on amd64 bsd and it runs quite nicely unmodified.
>
>[sam at bob ~]$ java -version
>java version "1.5.0"
>Java(TM) 2 Runtime Environment, Standard Edition (build diablo-1.5.0-b01)
>Java HotSpot(TM) 64-Bit Server VM (build diablo-1.5.0_07-b01, mixed mode)
>[sam at bob ~]$ 
>
>Sam
>
>-----Original Message-----
>From: owner-freebsd-java at freebsd.org on behalf of Mika Nystrom
>Sent: Thu 2/21/2008 9:07 PM
>To: freebsd-java at freebsd.org
>Cc: mika at camembert.async.caltech.edu
>Subject: Memory leak in 1.5.0 JVM
> 
>Hello there freebsd-java,
>
>I am running a binary downloaded 1.5.0 JVM on a FreeBSD 5.5 system:
>
>(167)rover:~/levinc/memleak>java -version
>java version "1.5.0"
>Java(TM) 2 Runtime Environment, Standard Edition (build diablo-1.5.0-b01)
>Java HotSpot(TM) Client VM (build diablo-1.5.0_07-b01, mixed mode)
>(168)rover:~/levinc/memleak>uname -a
>FreeBSD rover 5.5-RELEASE FreeBSD 5.5-RELEASE #4: Sat Nov 17 12:13:24 PST 2007     mika at rover:/usr/src/sys/i386/compile/ROVER  i386
>
>I have found the following program to leak memory on FreeBSD, but not on Windows with same Java 1.6.0, nor on Debian with gij 1.4.2:
>
>class Leakq {
>
>  private static class MyThread extends Thread {
>    public void run() 
>    {
>
>    }
>  }
>
>  public static void main (String[] args)
>  {
>    for(;;) {
>      (new MyThread()).start();
>    }
>  }
>}
>
>    Best regards,
>      Mika Nystrom
>      mika at alum.mit.edu
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