Re: kawa hanging while running input-parse.scm

[Seth Alves <alves at hungry dot com>]

With the code like this:

    public void loadHeapFrame (Compilation comp) {
        LambdaExp curLambda = comp.curLambda;
        while (curLambda != this && curLambda.getInlineOnly()) {
            if (curLambda == curLambda.getCaller())
                throw new Error("CYCLE for "+curLambda);
            curLambda = curLambda.getCaller();
        }

The error does get thrown -- I've attached the output.

One possible clue is that if I'm redirecting stdout:

  $ ./kawa-sometimes-hang.scm | cat
  #t

I can't get the program to hang.

    -seth


On 12/05/2014 02:50 PM, Per Bothner wrote:
> On 12/05/2014 12:49 PM, Seth Alves wrote:
> > jdb is telling me "Nothing suspended." (I haven't read the jdb docs 
> > yet), but jstack produced this when run against a hung process. 
> > Anything interesting?
> >
> >      -seth
> >
> > On 12/05/2014 11:58 AM, Per Bothner wrote:
> > > jdb -attach
> "main" prio=10 tid=0x00007fbf60009800 nid=0x13a9 runnable 
> [0x00007fbf6780f000]
>    java.lang.Thread.State: RUNNABLE
>     at gnu.expr.LambdaExp.loadHeapFrame(LambdaExp.java:523)
>     at gnu.expr.Declaration.loadOwningObject(Declaration.java:259)
>
> I'd say you have an infinite loop.  I'd add just before 
> LambdaExp.java:523:
> if (curLambda == curLambda.getCaller()) throw new Error("CYCLE for 
> "+curLambda);
>
> Once you'd verified that, the next step is finding where inlineHome is 
> getting set,
> and specifically where this.inlineHome==this happens.
>
> Then the next step is figuring why that is only happening sporadically,
> assuming that the case.

Attachment: kawa-sometimes-hang-error
Description: Text document