Re: Threading/Process Question

[Brent Fulgham <bfulgham@debian.org>]

On Wed, Nov 22, 2000 at 07:43:24PM -0800, Matthew Flatt wrote:
> The main problem here is that NULL is not allowed as the first argument
> to scheme_thread. It needs a procedure to start executing in the new
> thread.
> 
> Also, you don't want to supply the "config" (a set of parameter values)
> of the current thread to the created one, otherwise they'll share
> parameter values.
> 
> Instead, create a new one:
> 
>   scheme_thread(thunk, scheme_make_config(scheme_config));
> 
> [Note: the docs claim that NULL is a legal second argument to
> scheme_thread(), but it isn't anymore.]
> 

Must the new procedure be long-lived?  E.g., can it be something
as trivial as (+ 1 2)?

> >     ... Still later, I want to get back to thread "A"
> >     scheme_swap_process(proc);
> > 
> > However, this doesn't work right -- it causes me to segfault
> > when I try to execute code after the scheme_swap_process.
> 
> Actually, the segfault is within scheme_swap_process(), because it's
> trying to jump to the NULL procedure, right?
> 

Exactly!

> > Does "scheme_thread" return a real, usable Scheme_Process*,
> 
> Yes, assuming that it gets valid procedure and config values.
> 

Thanks.  Onward and upward....

Happy Thanksgiving!  

-Brent