* bug#21424: Bug#685919: guile-1.6: SIGALRM signal handler does not get called when guile blocks on I/O
[not found] <20120826131404.6959.57720.reportbug@localhost.localdomain>
@ 2015-09-06 17:18 ` Rob Browning
[not found] ` <handler.21424.B.14415599333771.ack@debbugs.gnu.org>
` (2 more replies)
0 siblings, 3 replies; 4+ messages in thread
From: Rob Browning @ 2015-09-06 17:18 UTC (permalink / raw)
To: 21424; +Cc: Panu Kalliokoski, 685919, 685919-forwarded
[If possible, please preserve the -forwarded address in any replies.]
Reference: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=765497
Panu Kalliokoski <panu.kalliokoski@gmail.com> writes:
> While playing with guile on my system, I discovered a weird anomaly
> which I could not reproduce on other systems running guile. If I
> install a signal handler for SIGALRM, it won't get called while guile is
> making an I/O system call. To demonstrate:
>
> [atehwa@karaihin ~/proj/psyk]$ guile
> guile> (alarm 2)
> 0
> guile> Herätyskello
> [atehwa@karaihin ~/proj/psyk]$ guile
> guile> (sigaction SIGALRM (lambda (x) (display "now!") (newline)))
> (0 . 335544320)
> guile> (alarm 2)
> 0
> guile> now a lot more than two seconds has passed, while I wrote this
> now!
> <unnamed port>: In expression now:
> <unnamed port>: Unbound variable: now
> ABORT: (unbound-variable)
> [...]
>
> As you can see, the signal handler gets called as soon as guile returns
> from read(2), already before calling (eval).
>
> I can't get to understand what causes this on my system, because another
> Debian system with exact same versions of guile-1.6, libc6 and
> libguile-ltdl-1 seems to work fine, and interrupts the read(2) call with
> the signal handler.
This appears to still be the case with at least Debian's 2.0.11+1-10
package, and setting the handler to something that doesn't perform IO
has the same effect (i.e. no alarm until you hit return):
(sigaction SIGALRM (lambda (x) (exit 1)))
Thanks
--
Rob Browning
rlb @defaultvalue.org and @debian.org
GPG as of 2011-07-10 E6A9 DA3C C9FD 1FF8 C676 D2C4 C0F0 39E9 ED1B 597A
GPG as of 2002-11-03 14DD 432F AE39 534D B592 F9A0 25C8 D377 8C7E 73A4
^ permalink raw reply [flat|nested] 4+ messages in thread
* bug#21424: Acknowledgement (Bug#685919: guile-1.6: SIGALRM signal handler does not get called when guile blocks on I/O)
[not found] ` <handler.21424.B.14415599333771.ack@debbugs.gnu.org>
@ 2015-09-06 17:49 ` Rob Browning
0 siblings, 0 replies; 4+ messages in thread
From: Rob Browning @ 2015-09-06 17:49 UTC (permalink / raw)
To: 21424, 765497-forwarded; +Cc: control
retitle 21424 guile-2.0: SIGALRM signal handler does not get called when guile blocks on I/O
thanks
GNU bug Tracking System <help-debbugs@gnu.org> writes:
> Thank you for filing a new bug report with debbugs.gnu.org.
Note: I used the wrong bug number (the old guile-1.6 clone) in the
original forwarding.
It should have been 765497, and so the Debian forwarded address would be
765497-forwarded@bugs.debian.org, as in the headers above.
Thanks
--
Rob Browning
rlb @defaultvalue.org and @debian.org
GPG as of 2011-07-10 E6A9 DA3C C9FD 1FF8 C676 D2C4 C0F0 39E9 ED1B 597A
GPG as of 2002-11-03 14DD 432F AE39 534D B592 F9A0 25C8 D377 8C7E 73A4
^ permalink raw reply [flat|nested] 4+ messages in thread
* bug#21424: Bug#685919: guile-1.6: SIGALRM signal handler does not get called when guile blocks on I/O
2015-09-06 17:18 ` bug#21424: Bug#685919: guile-1.6: SIGALRM signal handler does not get called when guile blocks on I/O Rob Browning
[not found] ` <handler.21424.B.14415599333771.ack@debbugs.gnu.org>
@ 2016-06-24 9:17 ` Andy Wingo
2025-01-12 19:52 ` bug#21424: guile-2.0: " Rob Browning
2 siblings, 0 replies; 4+ messages in thread
From: Andy Wingo @ 2016-06-24 9:17 UTC (permalink / raw)
To: Rob Browning; +Cc: 21424, Panu Kalliokoski, 685919, 685919-forwarded
It does seem clear that we have a bug here; evidently signals do not
wake up the reader, neither with readline nor without.
Andy
On Sun 06 Sep 2015 19:18, Rob Browning <rlb@defaultvalue.org> writes:
> [If possible, please preserve the -forwarded address in any replies.]
>
> Reference: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=765497
>
> Panu Kalliokoski <panu.kalliokoski@gmail.com> writes:
>
>> While playing with guile on my system, I discovered a weird anomaly
>> which I could not reproduce on other systems running guile. If I
>> install a signal handler for SIGALRM, it won't get called while guile is
>> making an I/O system call. To demonstrate:
>>
>> [atehwa@karaihin ~/proj/psyk]$ guile
>> guile> (alarm 2)
>> 0
>> guile> Herätyskello
>> [atehwa@karaihin ~/proj/psyk]$ guile
>> guile> (sigaction SIGALRM (lambda (x) (display "now!") (newline)))
>> (0 . 335544320)
>> guile> (alarm 2)
>> 0
>> guile> now a lot more than two seconds has passed, while I wrote this
>> now!
>> <unnamed port>: In expression now:
>> <unnamed port>: Unbound variable: now
>> ABORT: (unbound-variable)
>> [...]
>>
>> As you can see, the signal handler gets called as soon as guile returns
>> from read(2), already before calling (eval).
>>
>> I can't get to understand what causes this on my system, because another
>> Debian system with exact same versions of guile-1.6, libc6 and
>> libguile-ltdl-1 seems to work fine, and interrupts the read(2) call with
>> the signal handler.
>
> This appears to still be the case with at least Debian's 2.0.11+1-10
> package, and setting the handler to something that doesn't perform IO
> has the same effect (i.e. no alarm until you hit return):
>
> (sigaction SIGALRM (lambda (x) (exit 1)))
>
> Thanks
^ permalink raw reply [flat|nested] 4+ messages in thread
* bug#21424: guile-2.0: SIGALRM signal handler does not get called when guile blocks on I/O
2015-09-06 17:18 ` bug#21424: Bug#685919: guile-1.6: SIGALRM signal handler does not get called when guile blocks on I/O Rob Browning
[not found] ` <handler.21424.B.14415599333771.ack@debbugs.gnu.org>
2016-06-24 9:17 ` bug#21424: Bug#685919: guile-1.6: SIGALRM signal handler does not get called when guile blocks on I/O Andy Wingo
@ 2025-01-12 19:52 ` Rob Browning
2 siblings, 0 replies; 4+ messages in thread
From: Rob Browning @ 2025-01-12 19:52 UTC (permalink / raw)
To: 21424; +Cc: 685919-forwarded
Rob Browning <rlb@defaultvalue.org> writes:
> This appears to still be the case with at least Debian's 2.0.11+1-10
> package, and setting the handler to something that doesn't perform IO
> has the same effect (i.e. no alarm until you hit return):
>
> (sigaction SIGALRM (lambda (x) (exit 1)))
Just checked -- still true with 3.0.9.
Thanks
--
Rob Browning
rlb @defaultvalue.org and @debian.org
GPG as of 2011-07-10 E6A9 DA3C C9FD 1FF8 C676 D2C4 C0F0 39E9 ED1B 597A
GPG as of 2002-11-03 14DD 432F AE39 534D B592 F9A0 25C8 D377 8C7E 73A4
^ permalink raw reply [flat|nested] 4+ messages in thread
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2015-09-06 17:18 ` bug#21424: Bug#685919: guile-1.6: SIGALRM signal handler does not get called when guile blocks on I/O Rob Browning
[not found] ` <handler.21424.B.14415599333771.ack@debbugs.gnu.org>
2015-09-06 17:49 ` bug#21424: Acknowledgement (Bug#685919: guile-1.6: SIGALRM signal handler does not get called when guile blocks on I/O) Rob Browning
2016-06-24 9:17 ` bug#21424: Bug#685919: guile-1.6: SIGALRM signal handler does not get called when guile blocks on I/O Andy Wingo
2025-01-12 19:52 ` bug#21424: guile-2.0: " Rob Browning
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