Hi,
I have a working model where a main program starts threads
that dynamically load another named program.
It is like a plug-in style system.
I run it under Windows 2000, Activestate 5.8.
Now, I want multiple instances of the same loaded program
to share common resources. In my example I want a global static $q to be
accessed by the second invocation of "xy1".

1) How shall I do it if I place this resource in the main file?
2) How do I place this resource just in the loaded file (preferred)?
If this model can be inproved, please advise.

You can test it; In the stripped-down version below,
cut the code into 2 files, "xy_load.pl" and "xy1.pm",
and place in same directory.
TIA
J. Merc
#================== xy_load.pl  =============
#! /usr/bin/perl -w

use 5.008;             # 5.8 required for stable threading
   package xy_load;

use strict;
no strict 'subs';
no strict 'refs';
use warnings;
use threads;
use File::Basename;

  my $HOME = dirname($0);  # directory the program loaded from
  push(@INC, $HOME);       # Set in perl's include path list
  $| = 1;

  my $p = 0;  # counter
  my $sub = "xy1"; # the name of program to load
  my $thr1 = threads->create(\&start_thread, $sub, $p );
  $p++;
  my $thr2 = threads->create(\&start_thread, $sub, $p );
  $thr1->join;
  $thr2->join;

sub start_thread {
   my ($sub, $p )= @_;

   eval "require $sub"; # load the passed program
   &{"xy_load::" . $sub . "::Process"}($p); # and run it
}

#================  xy1.pm  ============
  package xy_load::xy1;

### I want $q as shared global to all invocations of "xy1",

my $q : shared = 0;
sub Process {
   my $p = $_[0];
   my $tid = threads->self->tid;
   $| = 1;
   {
     lock ($q);
     $q++;
     print STDERR "TID: $tid, p = $p, q = $q\n";
   }
}
1; # success status for require

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In reply to Threads, dynamic loading programs, and using globals? by Anonymous Monk

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