[racket-dev] [plt] Push #27825: master branch updated

Thanks!

I think Jay and I became confused about the purpose of
`call-with-limits` and thought it was supposed to constrain the time
used by evaluation, no matter what it tries to do.

We should revert the change, clarify the docs at `call-with-limits`,
and maybe add something else to `racket/sandbox`.

At Mon, 25 Nov 2013 05:02:07 -0500, Eli Barzilay wrote:
> IIUC, this makes the limit thing -- and therefore sandboxes -- behave
> *very* differently.  The original intention was that the time limit is
> on something similar to what you get with `time'.
> 
> A very visible way to see the effect of this change:
> 
>     -> ,r racket/sandbox
>     -> (define e (make-evaluator 'racket))
>     -> (e '(define foo 1))
>     -> (e '(thread (lambda () (sleep 5) (set! foo 2))))
>     #<thread>
> 
> This used to happen immediately, with the thread continuing to run
> inside the sandbox.  After your change, the last line hangs until the
> thread is done.  Using a bigger sleeping time will make it throw an
> error when it previously didn't.  Similarly,
> 
>     (make-module-evaluator "#lang racket (thread (λ() (sleep 99)))")
> 
> used to work and will throw an error now, and of course, any code that
> runs some kind of sandboxed server will probably break now.
> 
> I think that instead of this, it'd be better to write a helper that
> runs a thunk and waits for it and for any generated threads to end,
> and suggest using this helper when you want to wait for all threads in
> a `with-limits'.  (It might also be useful in the profiler, where a
> similar kind of wait-for-all is done.)
> 
> 
> On Friday, jay at racket-lang.org wrote:
> > jay has updated `master' from e0026f5de4 to 79f8636e1e.
> >   http://git.racket-lang.org/plt/e0026f5de4..79f8636e1e
> > 
> > =====[ One Commit ]=====================================================
> > Directory summary:
> >   52.6% pkgs/racket-pkgs/racket-test/tests/racket/
> >   45.6% pkgs/sandbox-lib/racket/
> > 
> > ~~~~~~~~~~
> > 
> > 79f8636 Jay McCarthy <jay at racket-lang.org> 2013-11-22 14:25
> > :
> > | Ensure that threads created within call-with-limits are accounted
> > | during the time/space limits
> > :
> >   A pkgs/racket-pkgs/racket-test/tests/racket/sandbox.rkt
> >   M pkgs/sandbox-lib/racket/sandbox.rkt               | 81 
> ++++++++++++++------
> >   M .../racket-test/tests/racket/sandbox.rktl         | 48 ++++++++----
> >   M .../scribblings/reference/sandbox.scrbl           |  4 +
> 
> -- 
>           ((lambda (x) (x x)) (lambda (x) (x x)))          Eli Barzilay:
>                     http://barzilay.org/                   Maze is Life!
> 
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