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On Fri, 28 May 2004 10:10:48 +0200, Michael Borgwardt wrote:
> Very interesting detail. Then what can you do to reclaim the memory
> if you come to a point where you have instantiated a Thread but
> change your mind about running it? I can't seem to find anything in
> the Thread class that could be used to handle this case.

It seems you have to run it in that case. If you expect that you'll
create threads and later change your mind, you could always set a
field checked by the run method, then run the thread anyway:

public void run() {
if (!cancelled) {
...
}
}

/gordon

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"Roedy Green" <look-> wrote in message
news:...
> On Thu, 27 May 2004 11:58:52 +0200, Michael Borgwardt
> <> wrote or quoted :
>
> >It becomes *egligible* for garbage collection when its run() method
> >has finished executing. When it will actually *be* garbage collected
> >is up to the JVM to decide.
>
> Be careful. If you instantiate a Thread but never get around to
> calling the start method, it will hang around forever,
> even if you drop all references to it.
>
> see http://mindprod.com/jgloss/packratting.html

There is nothing the JavaDoc for Thread or ThreadGroup
that indicates that a JVM implementation is required
to hold an inactive Thread reference in the ThreadGroup.

When instantiating the Thread, there is nothing that
indicates that the Thread instance is referenced in the
ThreadGroup before the thread is started. The Thread
instance may hold a reference to the ThreadGroup to
which the thread will belong after the start() method
is called. The start() method could add the Thread
reference to the ThreadGroup at that time.

Your glossary is quite likely describing a particular
implementation detail that can change across different
JVM releases and almost certainly across different JVM
vendors.

Roedy Green wrote:
> Be careful. If you instantiate a Thread but never get around to
> calling the start method, it will hang around forever,
> even if you drop all references to it.

In fact, JDK 1.5.0 does not retain unstarted threads that otherwise become
unreachable. See <http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=4089701>.

On Fri, 28 May 2004 14:09:42 GMT, "xarax" <> wrote or
quoted :

>There is nothing the JavaDoc for Thread or ThreadGroup
>that indicates that a JVM implementation is required
>to hold an inactive Thread reference in the ThreadGroup.

Correct. But it does.

--
Canadian Mind Products, Roedy Green.
Coaching, problem solving, economical contract programming.
See http://mindprod.com/jgloss/jgloss.html for The Java Glossary.

Roedy Green wrote:
> On Fri, 28 May 2004 14:09:42 GMT, "xarax" <> wrote or
> quoted :
>
> >There is nothing the JavaDoc for Thread or ThreadGroup
> >that indicates that a JVM implementation is required
> >to hold an inactive Thread reference in the ThreadGroup.
>
> Correct. But it does.

The conveniently missed point here is that this statement is meaningless
unless you define "it". If "it" is a Sun release of the JVM prior to
1.5, then you're right.

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