[tcljava-user] Re: RE: [Tcl Java] Re: Interrupting a Interp.eval()

[W. J. G. <gu...@ea...>]

Sorry for the late reply - it's been a long time (and a couple of projects
;) since I played with Tcl/Tcl Blend.

We had the same issue with "runaway TCL interps." I solved it by adding a
flag to the interp structure, which the Tcl byte code engine checks after
each individual bytecode execution. If the flag is non-zero, the bytecode
engine does an "abnormalReturn" which causes it to abort (cleanly!) I then
added a new method that can be called on the interp - abortExecution().

it seems to work quite well.

john


> -----Original Message-----
> From: Mo DeJong [mailto:md...@cy...]
> Sent: Thursday, July 27, 2000 6:18 PM
> To: Marc Saegesser
> Cc: tc...@sc...
> Subject: [Tcl Java] Re: Interrupting a Interp.eval()
>
>
> On Thu, 27 Jul 2000, Marc Saegesser wrote:
>
> > I'm embedding several Tcl interpreters inside a JVM.  I'm
> currently using
> > Jacl, but will probably switch to TclBlend at some point in the future.
> >
> > I'm trying to work out the best approach for cleanly shutting down these
> > embedded interpreters.  If everything is running normally, I can post a
> > TclEvent object whose processEvent() method calls Interp.dispose() and
> > causes the event loop to terminate.
> >
> > The problem with this is that I don't see a way to stop an
> interpreter that
> > has run amok.  Suppose that Interp.eval() is processing a script that is
> > stuck in an infinite loop.  The notifier's event loop isn't
> processing new
> > events to my shutdown TclEvent will never get processed.  Is
> there a good
> > method for aborting a call to Interp.eval()?
>
> There is no way to do this in Jacl. The "how do I stop a runaway thread"
> problem is a very tricky one. The best you can really do is put and event
> into the queue and code your app so it notices the "quit now" event.