[news.eclipse.platform.swt] Re: javaw.exe keeps running in Windows

[ewing@xxxxxxxxx (Bill Ewing)]

Hi Steve.  Yes, confirmed.  Our problem was a combination of JFace and a 
GUI designer which is now fixed.  To summarize, main method was missing 
"Display.getCurrent().dispose()" below:

public static void main(String args[]) {
 try {
   MainWindow window = new MainWindow();
   // (MainWindow is an ApplicationWindow)
   window.setBlockOnOpen(true);
   Display.getCurrent().dispose();
 } catch (Exception e) {
   e.printStackTrace();
 }
}





Steve Northover wrote:

> Ok, it was a combination of the GUI builder and JFace.  I just want to
> confirm with you that SWT doesn't do anything special to keep running.

> "Bill Ewing" <ewing@xxxxxxxxx> wrote in message
> news:ct442e$t3m$1@xxxxxxxxxxxxxxxxxx
> > Bill Ewing wrote:
> >
> > > Steve Northover wrote:
> >
> > >> The java VM will not keep running if you fail to dispose an SWT
> resource.
> > >> Are you exiting from your event loop?
> >
> > >> "Bill Ewing" <ewing@xxxxxxxxx> wrote in message
> > >> news:csrshl$asq$1@xxxxxxxxxxxxxxxxxx
> > >>> In Task Manager, you see an instance of javaw.exe (Windows' jvm
> launcher)
> > >>> appear when you start eclipse.  We see another instance appear when we
> run
> > >>> our JFace app (either under eclipse or standalone).
> > >>>
> > >>> After exiting our app, its javaw.exe does not disappear from Task
> Manager.
> > >>>  They pile up, one for each run.  Eventually, system problems begin to
> > >>> occur.  Plus, when you try to shut down windows, you get all of these
> > >>> instances not responding to windows.
> > >>>
> > >>> It sure sounds like a memory leak, or a failure to dispose a system
> > >>> resource, such as a non standard color.
> > >>>
> > >>> But, we've scoured our app and commented out all such Color creations.
> We
> > >>> don't do anything with fonts, so we're out of ideas as to what would
> cause
> > >>> this problem.  We have verified that this problem does not occur with
> > >>> simplistic apps.
> > >>>
> > >>> Anyone have any ideas on...?
> > >>>  1. What our problem is
> > >>>  2. Strategies for troubleshooting
> > >>>
> >
> > > Thank you for taking the time to post, Steve.  The information in your
> > > response is valuable to us.
> >
> > > We are using JFace.  Specifically, we have an ApplicationWindow class
> that
> > > contains a main method.  So, I believe handling the event loop is
> > > automatically done by ApplicationWindow-- it's buried and not available
> > > for us to see (until we figure out how to attach source and JavaDoc to
> > > libs we use).
> >
> > > What would you suggest we look at next?
> >
> > > I was in the process of commenting out chunks of the program, piece by
> > > piece until the zombie javaw.exe no longer hangs around in Task Manager.
> >
> > > But now, the knowledge that failure to dispose() would not cause this
> > > problem makes us wonder just what sort of problem we are chasing.
> >
> > > Our main method looks like the following.  It was auto-generated by the
> > > GUI builder available from swt-designer.com.
> >
> > > public static void main(String args[]) {
> > > try {
> > > MainWindow window = new MainWindow();
> > > window.setBlockOnOpen(true);
> > > window.open();
> > > } catch (Exception e) {
> > > e.printStackTrace();
> > > }
> > > }
> >
> >
> > OK, it looks like we were not dispose'ing Display.  Thank you Bahram, for
> > suggesting that earlier.
> >
> > The reason that this stumped us is that all of the code is autogenerated
> > by a GUI designer tool that we assumed worked.  We've contacted the
> > manufacturer (who sent us here).
> >
> > Our new main method now looks like below.
> >
> > public static void main(String args[]) {
> > try {
> > MainWindow window = new MainWindow();
> > window.setBlockOnOpen(true);
> > Display.getCurrent().dispose();
> > } catch (Exception e) {
> > e.printStackTrace();
> > }
> > }