#!/usr/bin/perl -w

use threads;
use threads::shared;

share $threadscount;
$threadscount = 0;
share $maxthreads;
$maxthreads = 0;
share $threadscreated;
$threadscreated = 0;

# Dump out virtual memory and resident memory consumption
sub printmemorysizes{
		open F, "</proc/self/status";
		my @s = <F>;
		close F;
		my @vmsize = grep /^VmSize.*/, @s;
		chomp $vmsize[0];
		print $vmsize[0], " ";
		my @rss = grep /^VmRSS/, @s;
		print $rss[0];
}

# The treads' sub
sub thread{
		my $count;
		{ 
				lock $threadscount;
				$threadscount ++; # count how many threads there are
				$count = $threadscount;

				lock $maxthreads;
				if ( $count>$maxthreads ){
						$maxthreads = $count; 
   # Store the maximum of concurrent threads
				}
				lock $threadscreated;
				$threadscreated ++;
		}
		#print "threadscreated: $threadscreated ";
		#&printmemorysizes();
		select undef,undef,undef,1;

		lock $threadscount;
		$threadscount --;
}

while ( 1 ){
		for ( 1..300 ){
				my $t = threads->create("thread");
				$t->detach();
		}
		my $tc;
		do {
				select undef,undef,undef,0.1; # SLEEP
# as shorter the sleep the memory cunsumption raises faster it seems
				
				lock $threadscount;
				$tc = $threadscount;
		} while ( $tc );
		#sleep 2;

# dump out: 
#maximum concurrent threads | How many threads have been created | 
# virtual memory size | resident memory size
print "maxthreads: $maxthreads  threadscreated: $threadscreated  ";
		printmemorysizes();
		$maxthreads = 0;

}