[Soot-list] Undeterministic processing order

[David Mohr]

Thanks everyone for the comments.

It's not that complicated after all: Soot uses mostly the nice Chain
interface, but in Scene.prepareClasses() it mangles the classes using
a HashSet, which destroys the order. The prepareClasses() function
maybe could be improved, but it suffices to use a Chain instead of a
Set in that function to preserve order.

Attached is a patch against 2.3.0 which fixes this.

Note that I haven't tested it with any excludes.

~David

On Wed, Oct 21, 2009 at 9:33 AM, Patrick Lam <plam at sable.mcgill.ca> wrote:
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> Let me just comment that it's a bit tricky to figure out how Soot
> figures out which classes to process. Last year, I started to figure out
> how one might parallelize class processing; obviously, one has to find
> the queue of classes to process to parallelize processing. However, I
> ran out of time and had to do other things, like writing papers. Syed is
> looking into finishing the job I did with parallelization, though, and
> he might have something to say about this in a week or so.
>
> pat
>
> Prof. Laurie Hendren wrote:
>>   David,
>>
>> Yes, it is annoying.  I know we removed some of these non-deterministic
>> data structures for exactly that reason.   If you find where it is
>> happening and have a suggested fix which wouldn't impact performance
>> otherwise, please suggest it.
>>
>> Cheers, Laurie
>>
>>
>> +-----------------------------------------------------------------
>> | Laurie Hendren --- laurie.hendren at mcgill.ca <mailto:laurie.hendren at mcgill.ca>
>> | Associate Dean (Academic), Faculty of Science,
>> | Dawson Hall, McGill University, 853 Sherbrooke St W,
>> | Montreal QC H3A 2T6 Canada, 514-398-7179, fax 514-398-1774
>> +----------------------------------------------------------------
>> | For contact and home page info as Professor, Computer Science:
>> | http://www.sable.mcgill.ca/~hendren   ---  hendren at cs.mcgill.ca <mailto:hendren at cs.mcgill.ca>
>> | Research: http://www.sable.mcgill.ca  http://aspectbench.org
>> +----------------------------------------------------------------
>>
>>
>>
>> David Mohr wrote:
>>> On Wed, Oct 21, 2009 at 9:17 AM, Patrick Lam <plam at sable.mcgill.ca> <mailto:plam at sable.mcgill.ca> wrote:
>>>
>> I'll bet that Soot puts classes into a non-list data structure that
>> doesn't preserve order.
>>
>>>> Ah that makes sense.
>>>>
>>>> It is annoying when hunting bugs though, because if you rerun Soot
>>>> after fixing something, you might encounter some other bug first.
>>>>
>>>> ~David
>>>>
>>>>
>> David Mohr wrote:
>>
>>>>>> Hi,
>>>>>> I've noticed that soot processes classes in some seemingly random
>>>>>> order. At the very least, it's not always the same for identical
>>>>>> invocations of Soot. Is there a particular reason for this behavior?
>>>>>>
>>>>>> ~David
>>>>>> _______________________________________________
>>>>>> Soot-list mailing list
>>>>>> Soot-list at sable.mcgill.ca <mailto:Soot-list at sable.mcgill.ca>
>>>>>> http://mailman.cs.mcgill.ca/mailman/listinfo/soot-list
>>>>>>
>>>>
>
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