http://qs321.pair.com?node_id=172819

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

I have about ten routines that are common to a number of classes. These routines are kept in a package called Func. After profiling an application with DProf, I was surprised to find that most of the time is being spent in the BEGIN section of Func. Here is the output from the profiler: 
Total Elapsed Time = -36.6621 Seconds
  User+System Time = 86.44528 Seconds
Exclusive Times
%Time ExclSec CumulS #Calls sec/call Csec/c  Name
 28.4   24.62 28.883 738874   0.0000 0.0000  SE::Util::Func::BEGIN

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Here is the top of the Func module: 
package SE::Util::Func;

use Exporter;
@ISA = ('Exporter');
@EXPORT= qw(  SE_cat SE_dump SE_getName SE_getValue SE_isTag SE_matchN
+ame SE_matchNamePattern SE_prog SE_trim );
    
require 5.6.1;
use strict;

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Why is perl spending so much time in the BEGIN section of Func? Thanks.

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Re: Why is perl spending so much time in the BEGIN section?
by chromatic (Archbishop) on Jun 08, 2002 at 21:50 UTC
    Exporter's a bit heavy compared to small programs. Why does that show up in BEGIN blocks in your code? Well... 
    $ bleadperl -MO=Deparse
package SE::Util::Func;
use Exporter;
@ISA = ('Exporter');
@EXPORT= qw(  SE_cat SE_dump SE_getName SE_getValue SE_isTag );
require 5.6.1;
use strict;

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    produces: 
    package SE::Util::Func;
@ISA = 'Exporter';
@EXPORT = ('SE_cat', 'SE_dump', 'SE_getName', 'SE_getValue', 'SE_isTag
+');
require 5.006001;
sub SE::Util::Func::BEGIN {
    package SE::Util::Func;
    require Exporter;
    do {
        'Exporter'->import
    };
}

sub SE::Util::Func::BEGIN {
    package SE::Util::Func;
    require strict;
    do {
        'strict'->import
    };
}

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Re: Why is perl spending so much time in the BEGIN section?
by Anonymous Monk on Jun 08, 2002 at 20:43 UTC
    I don't know because your slow code could be many places inside of the module. It could be pretty much anything you are doing when you just execute the module, opening a database connection, initializing variables, etc.

    Just try to use SE::Util::Func and see how slow that is, then put print statements in the module to see where it gets to in a hurry, and where it slows down.

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