Re: threads in 1.7.1

[Neil Jerram]

Julian Graham wrote:

> If I started trolling, do you think I'd get more responses to my
> question?

I wonder the same myself :-)

>  Just kidding.  Anyway, I know you're all busy with real
> work and the like, but Marius (since I'm told this is pretty much your
> domain) -- is there any reason that Guile *shouldn't* support thread
> cancellation?  I was thinking maybe I'd just try to write it myself
> and submit a patch, unless there was some philosophical opposition to
> that idea.

FWIW, with me not being at all an expert on this area:

- It isn't yet possible to have more than one thread of C code call 
Guile functions.

- Guile's threads in 1.7.1, OTOH, are compatible with Posix threads, 
because they are Posix threads.  In more detail:

  - Guile 1.6.x supported coop threads, and kind-of Posix threads (with 
some kind of hack I believe)

  - Guile 1.7.x has dropped coop threads, and now only supports Posix 
threads.

  (I'm not sure of the rationale for dropping coop threads; personally 
I'm a fan of them.)

- I doubt it would Just Work to call pthread_cancel on a Scheme thread, 
because of the per-thread state that Guile maintains.  I'd guess, 
though, that it shouldn't be hard to add cancellation support, given 
that Guile threads are now Posix threads.

Hopefully this is all sufficiently inaccurate that someone will be 
forced to correct it :-)

Regards,
     Neil