in reply to Need Help With Alarm And Eval

The problem is local inside sub On. Perl restores $SIG{'ALRM'} as soon as On returns. You have no other handler for that signal, so the default handler kicks in and kills perl.

Alexander

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Today I will gladly share my knowledge and experience, for there are no sweeter words than "I told you so". ;-)

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Re^2: Need Help With Alarm And Eval
by PerlRocks6345 (Novice) on Dec 06, 2012 at 12:59 UTC

    Hey thanks a lot for your reply removed local and every thing worked perfectly!!!! Thanks a lot!!!!!

[reply]
      removed local and every thing worked perfectly

      No, it doesn't. The On function sets the signal handler globally, for ever, even after eval has finished. You want local $SIG{'ALRM'} inside that eval.

      The extra subs don't make your code any clearer. I think you should keep alarm and local $SIG{'ALRM'} inside the eval.

      You could also consider writing a generic timeout function like this:

      # untested

sub withTimeout
{
    my ($timeout,$worker,$timeouthandler)=@_;
    eval {
        local $SIG{'ALRM'}=sub { die "TIMEOUT" };
        alarm($timeout);
        $worker->();
        alarm(0);
    };
    if ($@ and $@=~/TIMEOUT/) {
        $timeouthandler->();
    }
}

      [download]

      Alexander

      --
      Today I will gladly share my knowledge and experience, for there are no sweeter words than "I told you so". ;-)
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        Hey Thank you.My problem is ,I want subs to switch on and off my alarm so that i can call them when needed. Any suggestion how to do that ?

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