sending signal to self with kill on windows

bulk88 has asked for the wisdom of the Perl Monks concerning the following question:

I am trying to send a signal from a Perl process to the same Perl process on Windows to run one of the %SIG handlers. So far I have

use warnings;
use strict;
use Config;
use Data::Dumper;
my (%signo, @signame, $i);
$i = 0;
defined $Config{sig_name} || die "No sigs?";
foreach my $name (split(' ', $Config{sig_name})) {
    $signo{$name} = $i;
    $signame[$i] = $name;
    $i++;
}

print Dumper(\@signame);
sub sighandler {
    print "sighandler called\n";
}
$SIG{BREAK} = \&sighandler;
sub s1 {
    kill("BREAK", $$);
}
s1();
sleep 1;
print "after sleep\n";
exit;
[download]

The output I got was

$VAR1 = [
          "ZERO",
          "HUP",
          "INT",
          "QUIT",
          "ILL",
          "NUM05",
          "NUM06",
          "NUM07",
          "FPE",
          "KILL",
          "NUM10",
          "SEGV",
          "NUM12",
          "PIPE",
          "ALRM",
          "TERM",
          "NUM16",
          "NUM17",
          "NUM18",
          "NUM19",
          "CHLD",
          "BREAK",
          "ABRT",
          "STOP",
          "NUM24",
          "CONT",
          "CLD"
        ];
after sleep
[download]

Why wasn't the %SIG handler called?

edit: remove wrong wording, tip from browseruk

Comment on sending signal to self with kill on windows Select or Download Code

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Re: sending signal to self with kill on windows (updated); by BrowserUk (Patriarch) on Dec 30, 2012 at 05:54 UTC
Why wasn't the %INC handler called? What the heck is an " %INC handler"? Update: assuming you mean %SIG handler; I think this demonstrates that the Perl Windows sig emulation has code to prevent a process from attempting to signal itself: `C:\test>start /b perl -E"say $$; sleep 10000" C:\test>192904 C:\test>perl -E"kill 21, 192904 or die $^E" Terminating on signal SIGBREAK(21) C:\test>perl -E"kill 21, $$ or say $^E; say 'ending';" The parameter is incorrect ending` [download] It doesn't make a great deal of sense to signal yourself to invoke a subroutine when you can just: `C:\test>perl -wE"$SIG{BREAK}=sub{ say 'BREAKing' }; &{$SIG{BREAK}}; sa +y 'ending'; " BREAKing ending` [download] With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday' Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error. "Science is about questioning the status quo. Questioning authority". In the absence of evidence, opinion is indistinguishable from prejudice.	[reply] [d/l] [select]
Re^2: sending signal to self with kill on windows (recursive sig-handler) by LanX (Saint) on Dec 30, 2012 at 21:12 UTC
> I think this demonstrates that the Perl Windows sig emulation has code to prevent a process from attempting to signal itself: Definitely! I had this at one of my projects... My face and all my hairs went pale, when I realized that a young colleague of mine called warn within `$SIG{__WARN__}`-handler. As it turned out Perl was (since 5.8 IIRC) idiot proof. It locally resets signal handler redirections before calling them. My colleague insisted that I exaggerated, because she "tested" (i.e ran) it once before committing into production. Her warn did depend on an if clause and "production" meant a central module of a mod-perl environment... Cheers Rolf UPDATE: from warn `Most handlers must therefore make arrangements to actually display the warnings that they are not prepare +d to deal with, by calling "warn" again in the handler. Not +e that this is quite safe and will not produce an endless loop +, since "__WARN__" hooks are not called from inside one.` [download]	[reply] [d/l] [select]


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