=begin
the goal of this module is for us to have a way of keeping track of objects
accross processes
=cut

#using ipcs command in linux to see shared memory segments and shared semaphores
#ipcrm deletes those shared structures
package ObjectMonitor; #monitors all instances of objects over multiple processes

use strict;
use warnings;
use feature 'say';
use Data::Dumper;
use IPC::ShareLite;
use Storable qw/ freeze thaw /;

my $newcall=0;

sub new {
    my($class,$key_id) = @_;
    say 'call:'.++$newcall;
    my $shared=undef;
    my $just_created=0;
    my $self;
    my @data;
    eval {
	say "ALREADY";
	$shared = IPC::ShareLite->new(
	    -key     => $key_id,
	    -create  => 'no',
	    -destroy => 'no'
	);
	@data = @{ thaw( $shared->fetch() )  };
	push @data,{
	    id => $data[-1]->{id}+1,
	    pid=> $$,
	};
	$shared->store(freeze(\@data));
    };
    unless($shared) {
	say "NEW SHARED!";
	$shared = IPC::ShareLite->new(
	    -key     => $key_id,
	    -create  => 'yes',
	    -destroy => 'no'
	);
	push @data,{
	    id => 0,
	    pid=> $$,
	};
	$shared->store(freeze(\@data));
	$just_created=1;
    };

    $self->{key_id}= $key_id;
    $self->{shared}= $shared;
    #say Dumper \@data;
    #$self->{cross_process_id}=$data[-1];

    return bless($self , $class);
}

sub print_ids {
    my($self) = @_;
    my @data = @{ thaw($self->{shared}->fetch) };
    #say Dumper \@data;
}


sub DESTROY {
    my ($self) = @_;
    return unless $self->{shared};
    my $cross_id = $self->{cross_process_id};
    my @data =  @{ thaw( $self->{shared}->fetch ) };
    say scalar @data;
    @data = grep{ $_->{id} != $self->{cross_process_id}  } @data;
    $self->{shared}->store(freeze(\@data));
    say scalar @data;
    say "DESTROYED !";
}

1;