[elephant-devel] strange bug related to psets

[Ian Eslick]

This happens in your application, or only in the tests?  Can you give  
me the exact sequence and state you use to reproduce?  Do you have a  
fresh lisp & fresh DB?  Does it still show up if you close the store,  
open a fresh one, and try again?  There is likely to be some state  
somewhere and identifying the environmental dependencies should help  
us localize where that is.

Thank you,
Ian

On May 10, 2008, at 9:35 AM, Ryszard Szopa wrote:

> Hello,
>
> I have run into a very strange bug related to psets. I create some
> persistent objects with psets as slot-values, and at some point one of
> those psets that should be empty contains 5 integers, usually in
> descending order with a step equal 5. For example
>
> (values pset (pset-list pset)) => #<DEFAULT-PSET oid:17> (20 15 10 5  
> 0)
>
> (the exact numbers may vary: most often it starts from 20).
>
> The bug appeared for the first time in a unit test. Before running
> that test, I open a new BDB store in an empty directory, so it is
> rather unlikely that my code at some point before puts the extra
> values into the pset. What is more, the bug does not appear the first
> time I run the test: only in the second and subsequent runs. In order
> to get rid (at lest temporarily) of this bug, it is enough to run
> (make-pset) somewhere in the code before creating my objects.
>
> It looks as if there was some pset floating in memory, which
> accidentally gets reused while making my new pset. Does anybody have
> any idea how to hunt this bug down?
>
> I am using elephant as in the darcs repository and the BerkeleyDB
> (4.6) backend, on SBCL 1.0.15, x86 Linux version.
>
> Oh, and I can actually reproduce this bug, but I wasn't able to factor
> it down not to contain major parts of the application I am writing.
>
> Thanks in advance,
>
>    -- Richard
>
> PS. I'd like to apologize: I have asked a question ("question about
> persistent classes") on this group before, and got some interesting
> answers, but then failed to thank for them. I was planning to write an
> elaborate answer etc., but then there was ECLM, I had a lot of work to
> do... You probably know how it goes. So, let me fix my mistake now:
> thank you, Robert, Ian and Alex.
>
> -- 
> http://szopa.tasak.gda.pl/
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