[racket-dev] Where does this program allocate?

I've been trying to use the new futures visualizer (which is great) to
improve my parallel version of the mandelbrot benchmark
(collects/tests/racket/shootout/mandelbrot-futures.rkt).  My current
code is attached.  You can run it like this:

    $ racket mand.rkt 4000 8 # 8 is the number of futures to use.

The visualizer shows that each future syncs thousands of times for
allocation.  However, I can't find the allocation in the loop at all
(even in the decompiler output).  Does anyone have any suggestions on
what might be allocating here, or any strategies I can use for finding
the allocation?
-- 
sam th
samth at ccs.neu.edu
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