[racket-dev] TR tests sometimes fail with a promise error

At Fri, 3 May 2013 12:17:46 -0400,
Eli Barzilay wrote:
> 
> A few minutes ago, Vincent St-Amour wrote:
> > At Fri, 3 May 2013 11:56:02 -0400, Eli Barzilay wrote:
> > >     (define (delay/thread thunk)
> > >       (let ()
> > >         (define p (make-promise/thread #f))
> > >         (pset! p (make-running-thread (thread (λ() ...same...))))
> > >         p))
> > 
> > I think that introduces another race condition.
> > 
> > If the thread is forced before the `pset!', then `force' would
> > return #f (line 107 of racket/promise.rkt), since the value inside
> > the `promise/thread' is not a thread.
> 
> But this can't happen because `delay/thread' won't return with the
> broken promise until after the `pset!' fixed it.
> 
> (Even code in the input thunk will not be able to try to force itself
> without having itself accessible as a value.)

Makes sense. I'll give it a try.

Vincent