[Checkers] NonNull checker Performance

[Matt Papi]

Mahmood,

Thanks! That information was very helpful.

I just got rid of the use of getPath() in nearestEnclosing via
visitorState. (This one's especially important since that call is part
of the implementation for @Default and moving that into the framework
is high on my todo list.)

There's a call to each of getPath() and declarationFromElement() to
work around the (Sun) bug in javac in which elements for exception
parameters have the kind PARAMETER instead of EXCEPTION_PARAMETER. I
think I've found a way to get rid of both calls.

 - Matt

On Mon, Apr 21, 2008 at 7:02 PM, Mahmood Ali <mahmood at mit.edu> wrote:
>
>  On Apr 21, 2008, at 2:49 PM, Matt Papi wrote:
>
> >
> > > That is long, but it doesn't take very long to compile.  Is there some
> > > remaining inefficiency in the checker?
> > >
> >
> > There could very well be. However, I don't expect the NonNull checker
> > to be as fast as, say, the Interned checker; NonNull calls into the
> > factory for every member select [...]. It does seem like it's slower than
> it
> > should be, but not so slow as to be alarming at this point.
> >
>
>  I ran the profiler in a VM (so it's significantly slower there than in my
> machine) with a random three files in daikon and FunctionBinary.java.  The
> top four bottle-neck methods are:
>
>  - Trees.getPath()     -- 150 seconds (49% of total time)        average
> time: 4.9s      invocations: 30,237
>         Basically as a result of
> NonNullAnnotatedTypeFactory.nearestEnclosing()
>
>  - TreeInfo.declarationFor() -- 27.7 seconds (9% total time)     average
> time: 3.2s      invocations: 8,672
>         All calls are from AnnotatedTypeFactory.declarationFromElement()
>  Note: Internally, declarationFor() does a search also for all the ASTs to
> get the declaration.
>
>  - TreePath.getPath() -- 16.6 seconds (5% total time)            average
> time: 3.7s    invocations: 4,422
>         All calls are from TypeFromTree$TypeFromMember.visitVariable()
>
>  - Element.getAnnotation() -- 6 seconds (2% total time)          average
> time: 10ns    invocations: 675,292.
>
>  While NonNull checks every single member select, it is not obvious to me
> that it's the reason.  AnnotatedTypeFactory.getAnnotatedType() amounts to
> just less than 3 seconds (0%) of the total run time.
>
>  - Mahmood
>