Re^4: Isolating dynamically loaded modules with Thread::Isolate.

[gmpassos]

Maybe this can help you. With a normal Perl thread, create 2 threads, make the 2 thread load 2 pages, let's say www.perlmonks.com, but you need to do all of this loading only 1 time LWP::Simple.

Remember that when you create 2 threads and use LWP::Simple from this 2 threads you are loading LWP::Simple 2 times in the memory since Perl duplicate everything when a thread is created. If you play a while with threads you will see that Perl threads use to much memory, so I can't load more than 10 threads to do a real job. With Delphi for example we can load more than 30 threads and still have a good execution, with Perl if I use more than 8 I start to see the application to be slow! Is more about performance and not what is possible to do.

Here's a simple way to do that with Thread::Isolate:

  use Thread::Isolate ;
  
  $|=1 ;
  
  my $thi = Thread::Isolate->new() ;
  $thi->use('LWP::Simple');
  
  my $url = 'http://www.perlmonks.com/' ;
  
  my @threds = (
  threads->new( \&get_pages , $url ) ,
  threads->new( \&get_pages , $url ) ,
  ) ;
  
  foreach my $threds_i ( @threds ) {
    $threds_i->join ;
  }
  
  print "INC:\n" ;
  
  foreach my $Key (sort keys %INC ) {
    print "$Key\n" ;
  }

sub get_pages {
  my $url = shift ;

  my $html = $thi->call('LWP::Simple::get' , $url) ;
  
  print "GOT PAGE: ". length($html) ." bytes\n" ;
}

[BrowserUk]

This is what I got from your script above:

P:\test>426324
GOT PAGE: 61833 bytes
GOT PAGE: 61456 bytes
INC:
AutoLoader.pm
Carp.pm
Config.pm
DynaLoader.pm
Exporter.pm
Exporter/Heavy.pm
Fcntl.pm
Storable.pm
Thread/Isolate.pm
XSLoader.pm
attributes.pm
c:/Perl/lib/auto/Storable/_freeze.al
c:/Perl/lib/auto/Storable/autosplit.ix
c:/Perl/lib/auto/Storable/freeze.al
overload.pm
strict.pm
threads.pm
threads/shared.pm
vars.pm
warnings.pm
warnings/register.pm
        (in cleanup) Can't call method "PUSH" on an undefined value at
+ c:/Perl/site/lib/Thread/Isolate.pm line 224 during global destructio
+n.

And this is what I got from my equivalent:

P:\test>426297
GOT PAGE: 61637 bytes
GOT PAGE: 61585 bytes
AutoLoader.pm
Carp.pm
Config.pm
DynaLoader.pm
Exporter.pm
overload.pm
strict.pm
threads.pm
vars.pm
warnings.pm
warnings/register.pm

Rather less loaded?

The script I used was:

#! perl -slw
use strict;
use threads qw[ async ];

my $thr = async {
    require LWP::Simple;
    return LWP::Simple::get( 'http://www.perlmonks.com/' );
};
print 'GOT PAGE: ', length $thr->join, ' bytes';

$thr = async {
    require LWP::Simple;
    return LWP::Simple::get( 'http://www.perlmonks.com/' );
};
print 'GOT PAGE: ', length $thr->join, ' bytes';

print for sort keys %INC;

[gmpassos]

Ok, now get your code and put it as a module and ensure that it will always load that!