"R. Kent Dybvig" <dyb_at_cs.indiana.edu> writes:
>> That's a strange way to interpret "separate," since both mechanisms
>> are joined with parameters. Why aren't dynamic binding and
>> thread-local storage separate?
>
> Hmm. I guess any mechanism that allows per-thread locations to be
> dynamically bound would be considered a combined mechanism by your
> definition. Are you suggesting that one should not dynamically bind
> per-thread locations?
No, I'm suggesting that one should dynamically bind *values*, not
locations, and do the locations mechanism orthogonally to that.
Again, the details are all in the paper.
>> Our Scheme workshop spells out exactly
>> what the semantic problems are. (Specifically, they occur when a
>> escape procedure created in one thread is invoked in another.)
>
> Again, I don't believe that there is a problem. Parameterize, like
> fluid-let, just assigns a new value on entry and restores the old on exit,
> and the semantics wrt thread-local paramters, even if the assignment is
> performed by a continuation created in another thread, is totally well
> defined.
... and how exactly is it defined? Does the contents of the location
migrate with the continuation? I'm assuming no, from your
description. However, it's often desirable (if mutation isn't
involved) for the value of a dynamic binding to migrate. So, I'm sure
the semantics is well defined, but it's often not the one I want. I'd
rather mix and match, which for me typically means not doing mutation
anyway.
--
Cheers =8-} Mike
Friede, V?lkerverst?ndigung und ?berhaupt blabla
Received on Mon Feb 12 2007 - 14:32:21 UTC