#!/usr/bin/perl
use warnings;
use strict;
use threads;

my $count = 0;

#  load a mem intensive thread first, then watch how mem  drops
# notice the difference in memory reclamation( top) after
# the following thread is run with heavy,medium, light mem

# on my machine
# heavy mem use will skyrocket to 75%, then drop to 2%
# medium will jump to 40% then drop to 20%
# light use will jump to 5% then stay there
# none use will stay at .3 %

#my $t = threads->new(\&do_my_thing, $count, 1000000); #light
#my $t = threads->new(\&do_my_thing, $count, 4000000); #medium
my $t = threads->new(\&do_my_thing, $count,    8000000);  #heavy
#my $t = threads->new(\&do_my_thing, $count, 1);  #none

$t->join;
select(undef,undef,undef,.1);
    
while (1) {
        $count++;
        print "thread $count started\n";         
        my $t = threads->new(\&do_my_thing, $count, 1 );
        $t->join;
        select(undef,undef,undef,.1);
    }

<>; #wait for keypress to end, to check top

sub do_my_thing {
    my ($val,$cdown) = @_;
    my %hash;
    for(0..$cdown){ $hash{$_} = 'a'; }
        
    select(undef,undef,undef,.1);
    print "thread $val ended\n";         
}