While we look into the other problems... What happens if you use `let' instead of the internal defines in `mandelbrot-point'?
There's a `set!' implicit in the `letrec' that is implicit in the use of internal definitions. Maybe the Typed Racket optimizations confuse the compiler so that it doesn't see how to convert the `let' into a `letrec'. At Wed, 25 Aug 2010 10:07:04 -0400, Sam Tobin-Hochstadt wrote: > On Wed, Aug 25, 2010 at 9:56 AM, Matthew Flatt <[email protected]> wrote: > > At Wed, 25 Aug 2010 09:42:40 -0400, Sam Tobin-Hochstadt wrote: > >> While trying to use futures to parallelize a simple piece of code, I > >> was able to remove all of the waiting except for this: > >> > >> future: 3 waiting for runtime at 1282743524205.783936: > [scheme_make_envunbox] > >> > >> which happens continuously. What causes this function to be invoked, > >> and how can I eliminate it? > > > > It happens when initializing a local variable that is assigned via > > `set!'. Probably we should inline scheme_make_envunbox() in > > JIT-generated code. > > Ok, that's kind of surprising. It seems that Typed Racket's optimizer > is transforming the program in such a way that the bytecode compiler > inserts `set!' where it wasn't before. I've attached the relevant > file (which is just TR applied to the mandlebrot example from the > futures paper). When the #:optimize keyword is used, the futures wait > on `scheme_make_envunbox'. When it isn't used, there's much less > waiting (just allocation and jitting). > > Unfortunately, trying to decompile this file produces an error in the > decompiler: > > [sa...@punge:~/tmp plt] raco decompile mandelbrot.rkt > hash-ref: no value found for key: 1128 > > so it's hard to tell exactly what's happening. > -- > sam th > [email protected] > > ------------------------------------------------------------------------------ > [application/octet-stream "mandelbrot.rkt"] [~/Desktop & open] [~/Temp & open] _________________________________________________ For list-related administrative tasks: http://lists.racket-lang.org/listinfo/dev
