Beefy Boxes and Bandwidth Generously Provided by pair Networks
Perl Monk, Perl Meditation
 
PerlMonks  

Re^2: Need Help With Alarm And Eval

by PerlRocks6345 (Novice)
on Dec 06, 2012 at 12:59 UTC ( #1007559=note: print w/replies, xml ) Need Help??


in reply to Re: Need Help With Alarm And Eval
in thread Need Help With Alarm And Eval

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

Replies are listed 'Best First'.
Re^3: Need Help With Alarm And Eval
by afoken (Monsignor) on Dec 06, 2012 at 15:08 UTC
    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/) { $errorhandler->(); } }

    Alexander

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

      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 ?

        I want subs to switch on and off my alarm so that i can call them when needed

        Why? The code you showed first is more or less the usual code for having a timeout in some long running code. (You do know the example in perlipc, right?) If you don't need a timeout, just don't mess with alarm and $SIG{'ALRM'} at all.

        In code:

        withTimeout(30,\&doSomething,sub { die 'Oooops, doSomething was too sl +ow' }); # <-- timeout after 30 seconds doSomething(); # <-- no timeout here

        If you still think that you need to "switch on and off", please explain your actual problem.

        Alexander

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

Log In?
Username:
Password:

What's my password?
Create A New User
Node Status?
node history
Node Type: note [id://1007559]
help
Chatterbox?
[choroba]: which usually means its input wasn't handled correctly
[Corion]: choroba: Yeah, I think that would be the good solution
[LanX]: I suspect the first string which comes from the DB ...
[LanX]: ... but this part is already in production for a year now
[Corion]: LanX: The "good" approach here would be to use the appropriate DBI parameters to make the driver decode strings properly. But that will have a ripple-on effect of messing up all the places where manual decoding happens ;)
[LanX]: which means albeit being broken UTF8 it'll be handled correctly
[LanX]: and the problem only occurs since we changed the emails to base64
[LanX]: my main problem will be to cnvince my colleagues that our productive code is broken oO ... so in the end I will just make a workaround :-/
LanX hates UTF8 for causing knots in his brain and stomach
[Corion]: LanX: Yes, that's the main problem - you have lots (and lots) of workarounds in various places and stages of the processing, and to clean that mess up requires action across the complete codebase. And it's almost impossible to do it piece-by-piece

How do I use this? | Other CB clients
Other Users?
Others making s'mores by the fire in the courtyard of the Monastery: (10)
As of 2017-01-16 14:02 GMT
Sections?
Information?
Find Nodes?
Leftovers?
    Voting Booth?
    Do you watch meteor showers?




    Results (150 votes). Check out past polls.