Why is perl spending so much time in the BEGIN section?

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;
[download]

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

Comment on Why is perl spending so much time in the BEGIN section? Select or Download Code

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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;` [download] 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 }; }` [download]	[reply] [d/l] [select]
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.	[reply] [d/l]