Re: "non interruptible" forms (deferred posix signals)

[Vladimir T. <vtz...@gm...>]

On Sat, 21 Feb 2009 01:12:59 +0200, Don Cohen <don...@is...> wrote:

>
>  > Following a discussion on clisp-list with Don about
>  > call-with-timeout behavior it looks good to introduce
>  > "non-interruptible" forms.
>
> I think you're missing something here.  The fact that a cleanup form
> could be in an infinite loop suggests that we still want to be able
> to interrupt it.  
> My first argument was that things like with-timeout,
> at least by default, should complete all of the cleanup forms.
> My second was that it seems important to be able to program a wide
> variety of options.  This is why I wanted to separate the interruption
> from the reaction.  I think adding a small amount of state would allow
> the reaction code (which should be able to do to all that the debugger
> now does), to do a wide variety of useful things, inc.
> - interrupt and go into the debugger (despite any without-interrupts)
> - interrupt and execute only (and all) cleanup code out to the closest
>   timeout, and return from the timeout
> I suggest that those two are a bare minimum, even if you don't want to
> support my more general scheme.
> 


That's the reason thread-interrupt will have an option not to pay attention in what form we are (so it will always be able to get in the debeugger for exmaple).
call-with-timeout by default will not interrupt "non-interruptible" forms - but deffer the interrupt for later.