Re: Bye from forks sends signals?
Dmitry Non
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https://libera.irclog.whitequark.org/picolisp/2024-01-10
On Tue, 9 Jan 2024 at 19:14, Dmitry Non wrote:
> Hey.
>
> That's awesome. Thank you very much, Alex!
>
> > On 6 Jan 2024, at 06:48, Alexander Burger
> wrote:
> >
> > Hi Dmitry,
> >
> >> Is this newsletter alive?:)
> >
> > Yes, just not so noisy :)
> >
> >
> >> I'm playing around with `native` and ZeroMQ and found a curious
> behaviour.
> >>
> >>(unless (fork)
> >> (wait 2000)
> >> (bye))
> >>
> >>(setq Context (native "libzmq.so" "zmq_ctx_new" 'P))
> >>(setq ZMQ_REP 4)
> >>(setq Socket (native "libzmq.so" "zmq_socket" 'P Context ZMQ_REP))
> >>(native "libzmq.so" "zmq_bind" 'I Socket "tcp://*:")
> >>
> >>(buf
> >> Buffer 10
> >> (prinl "Waiting for messages")
> >> (when (= -1 (native "libzmq.so" "zmq_recv" 'I Socket Buffer 10 0))
> >> (prinl (pack "Error: " (errno)
> >
> > This looks good.
> >
> >
> >> The `errno` is 4 (which is signal interrupt as i understand).
> >
> > Yes. EINTR is 4 on most systems. You can see it with
> >
> > : (sysdefs "errno")
> > -> EACCES
> > : EINTR
> > -> 4
> >
> > or (vi "@lib/sysdefs").
> >
> >
> >> My assumption here is that `bye` throws some signal? Why else would it
> affect
> >> zeromq in the parent process?
> >> Actually, while writing this I found out about SIGCHLD which is
> apparently
> >> sent to parent on child's exit so I guess zmq_recv gets interrupted by
> that
> >> for some reason?
> >
> > Absolutely correct. The child sends a SIGCHLD signal, which must be
> handled or
> > ignored.
> >
> > I don't have libzmq at the moment and cannot test it, but I think it
> should be
> > something like
> >
> > (while (lt0 (native "libzmq.so" "zmq_recv" 'I Socket Buffer 10 0))
> > (unless (== EINTR (errno))
> > (quit (errno) "Signal") ) )
> >
> >
> >> P.S. completely offtopic but since I'm here. I just noticed that
> semicolons
> >> aren't treated as comments. Why?
> >
> > Comments in PicoLisp are # or #{...}#.
> >
> >
> >> Can it be enabled? Otherwise my Emacs' lisp-mode comment/uncomment
> function is
> >> useless and no comment highlight either.
> >
> > There is no built-in way to change it. There are some Emacs libs for
> PicoLisp,
> > but I don't use Emacs and cannot be helpful here.
> >
> > ☺/ A!ex
> >
> > --
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>
>
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Re: Bye from forks sends signals?
Hey.
That's awesome. Thank you very much, Alex!
> On 6 Jan 2024, at 06:48, Alexander Burger wrote:
>
> Hi Dmitry,
>
>> Is this newsletter alive?:)
>
> Yes, just not so noisy :)
>
>
>> I'm playing around with `native` and ZeroMQ and found a curious behaviour.
>>
>>(unless (fork)
>> (wait 2000)
>> (bye))
>>
>>(setq Context (native "libzmq.so" "zmq_ctx_new" 'P))
>>(setq ZMQ_REP 4)
>>(setq Socket (native "libzmq.so" "zmq_socket" 'P Context ZMQ_REP))
>>(native "libzmq.so" "zmq_bind" 'I Socket "tcp://*:")
>>
>>(buf
>> Buffer 10
>> (prinl "Waiting for messages")
>> (when (= -1 (native "libzmq.so" "zmq_recv" 'I Socket Buffer 10 0))
>> (prinl (pack "Error: " (errno)
>
> This looks good.
>
>
>> The `errno` is 4 (which is signal interrupt as i understand).
>
> Yes. EINTR is 4 on most systems. You can see it with
>
> : (sysdefs "errno")
> -> EACCES
> : EINTR
> -> 4
>
> or (vi "@lib/sysdefs").
>
>
>> My assumption here is that `bye` throws some signal? Why else would it affect
>> zeromq in the parent process?
>> Actually, while writing this I found out about SIGCHLD which is apparently
>> sent to parent on child's exit so I guess zmq_recv gets interrupted by that
>> for some reason?
>
> Absolutely correct. The child sends a SIGCHLD signal, which must be handled or
> ignored.
>
> I don't have libzmq at the moment and cannot test it, but I think it should be
> something like
>
> (while (lt0 (native "libzmq.so" "zmq_recv" 'I Socket Buffer 10 0))
> (unless (== EINTR (errno))
> (quit (errno) "Signal") ) )
>
>
>> P.S. completely offtopic but since I'm here. I just noticed that semicolons
>> aren't treated as comments. Why?
>
> Comments in PicoLisp are # or #{...}#.
>
>
>> Can it be enabled? Otherwise my Emacs' lisp-mode comment/uncomment function
>> is
>> useless and no comment highlight either.
>
> There is no built-in way to change it. There are some Emacs libs for PicoLisp,
> but I don't use Emacs and cannot be helpful here.
>
> ☺/ A!ex
>
> --
> UNSUBSCRIBE: mailto:picolisp@software-lab.de?subject=Unsubscribe
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Re: Bye from forks sends signals?
Hi Dmitry,
> Is this newsletter alive?:)
Yes, just not so noisy :)
> I'm playing around with `native` and ZeroMQ and found a curious behaviour.
>
> (unless (fork)
> (wait 2000)
> (bye))
>
> (setq Context (native "libzmq.so" "zmq_ctx_new" 'P))
> (setq ZMQ_REP 4)
> (setq Socket (native "libzmq.so" "zmq_socket" 'P Context ZMQ_REP))
> (native "libzmq.so" "zmq_bind" 'I Socket "tcp://*:")
>
> (buf
> Buffer 10
> (prinl "Waiting for messages")
> (when (= -1 (native "libzmq.so" "zmq_recv" 'I Socket Buffer 10 0))
>(prinl (pack "Error: " (errno)
This looks good.
> The `errno` is 4 (which is signal interrupt as i understand).
Yes. EINTR is 4 on most systems. You can see it with
: (sysdefs "errno")
-> EACCES
: EINTR
-> 4
or (vi "@lib/sysdefs").
> My assumption here is that `bye` throws some signal? Why else would it affect
> zeromq in the parent process?
> Actually, while writing this I found out about SIGCHLD which is apparently
> sent to parent on child's exit so I guess zmq_recv gets interrupted by that
> for some reason?
Absolutely correct. The child sends a SIGCHLD signal, which must be handled or
ignored.
I don't have libzmq at the moment and cannot test it, but I think it should be
something like
(while (lt0 (native "libzmq.so" "zmq_recv" 'I Socket Buffer 10 0))
(unless (== EINTR (errno))
(quit (errno) "Signal") ) )
> P.S. completely offtopic but since I'm here. I just noticed that semicolons
> aren't treated as comments. Why?
Comments in PicoLisp are # or #{...}#.
> Can it be enabled? Otherwise my Emacs' lisp-mode comment/uncomment function is
> useless and no comment highlight either.
There is no built-in way to change it. There are some Emacs libs for PicoLisp,
but I don't use Emacs and cannot be helpful here.
☺/ A!ex
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