Subject: questions about the signal facility.

From: [email-masked] (Dan Stanger)
Date: Tue, 18 Apr 1995 11:15:04 -0600

i want to use SIGUSR1 to interupt a read in progress.  i also under
certain conditions want to hold signals.  is there a way to do this in
lisp or do i have to go to using c functions.
thanks,
dan stanger

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From: haible (Bruno Haible)
Date: Wed, 19 Apr 95 17:42:57 +0200

Dan Stanger <[email-masked]> wrote:

> i also under certain conditions want to hold signals ... is there
> a way to do this in lisp or do i have to go to using c functions.

Using the FFI, you should be able to call some C functions which perform
the necessary sigprocmask() calls.

> i want to use SIGUSR1 to interupt a read in progress.

Again, use the FFI. But you can't call Lisp functions from within the
signal handler: The interpreter and bytecode interpreter are not reentrant,
and on many systems you cannot even call malloc() from within a signal
handler.

                    Bruno Haible
                    [email-masked]