Re: [rvm-research] Object usage frequency within a method

[Eliot M. <mo...@cs...>]

MisterD123 wrote:
> Hey guys,
> 
> i'm facing a problem: i need some rather special kind of profiling
> information. Consider the following:
> 
> I have a method, for instance Collections.sort() which gets passed a
> Comparator object. The profiling information i'm looking for is an estimate
> how many calls on methods of that comparator object are made within the sort
> method to be able to decide, if it's worth trying a new optimization which
> we are currently implementing.
> 
> I need that profiling data to be able to differentiate mehtods worth
> optimizing (like Collections.sort() for instance) from methods not worth
> optimizing (like the constructor SortedSet(Comparator), which does not do
> any calls to the comparators methods for instance).
> 
> I'd be glad about any hints or even solutions on how to obtain that data.

If you just need the data and don't need to gather it within Jikes RVM,
you can get this kind of info from the standard TPTP measurement stuff
in Eclipse. It can count the number of calls made from your sort method
to a particular Comparator class, etc.

If you can change the Comparator class, you can add a counter to the
Comparator object to count how many times it is used. You might even
be able to ues bytecode rewriting on Comparator classes to get such
statistics collected automatically.

I'm sure other people can add to these ideas ....

Best wishes -- Eliot Moss