Re: Embedding a REPL in a Java application

[Per Bothner <per at bothner dot com>]

On 11/16/2009 12:28 AM, Per Bothner wrote:
> On 11/15/2009 01:43 PM, Jamison Hope wrote:
> > I tried that, actually. It led to a stream of
> > ArrayIndexOutOfBoundsExceptions like this:
> >
> > Exception in thread "AWT-EventQueue-0"
> > java.lang.ArrayIndexOutOfBoundsException: 24387
> > at gnu.lists.StableVector.allocPositionIndex(StableVector.java:111)
> > at gnu.lists.StableVector.createPos(StableVector.java:123)
> > at gnu.lists.SeqPosition.<init>(SeqPosition.java:55)
> > at gnu.kawa.swingviews.GapPosition.<init>(SwingContent.java:116)
> > at gnu.kawa.swingviews.SwingContent.createPosition(SwingContent.java:104)
>
> These appear to be thread contention between the AWT thread and the
> finalizer thread. Adding "synchronized" before every method in
> StableVector "fixes" the problem.
>
> A better solution would be avoid thread contention in the first place.
> That would seem to require changing gnu.lists.SeqPosition to use
> weak references rather than finalizers. I haven't looked into
> what would be involved.

It may be best to replace the use of SwingContent by
standard GapContent.  Not a completely trivial fix, but
doesn't look too difficult.  Could you try that?  The
non-trivial part is changing checkingPendingInput to use
GapContent.getChars and a Segment.
--
	--Per Bothner
per@bothner.com   http://per.bothner.com/