#!/usr/bin/perl

use strict;
use warnings;

use Time::HiRes qw(usleep gettimeofday);



my $microseconds = 1_000_000;


my $iter = 10;



my $tflux = 0;
my $flux = 0;
my $titer = $iter;
my $sleep = $microseconds;

my $count = 0;

my ($start_s, $start_m) = gettimeofday;
my ($is, $im) = ($start_s, $start_m);
my ($seconds, $micro) = ($start_s, $start_m);


my $diff = 0;

foo: {
	# tflux serves as gravity
	# flux serves as inertia
	$diff = int ( ($flux + $tflux) / 2 + 0.5);
	$sleep -= $diff;
	
	print "sleeping for $sleep\nelapsed time: " . (($start_s - $is) * 1_000_000 + $start_m - $im) . "\ntotal correction: $tflux\ncorrected from last: $flux\naverage: $diff\n";
	
	for (1 .. $iter){
		action();
		usleep $sleep;
	}
	
	($seconds, $micro) = gettimeofday();

	$flux = # difference from the last iteration
			(	(($seconds - $start_s) * 1_000_000) # elapsed seconds
							+
				$micro - $start_m # elapsed micro seconds
							-
				$microseconds * $iter # desired interval of entire loop
			) / $iter;
			
	$tflux = # difference from desired total time
			(
				(($seconds - $is) * 1_000_000) # elapsed seconds
							+
				$micro - $im # elapsed micro seconds
							-
				$microseconds * $titer # desired interval of entire loop
			) / $titer;
	
	$titer += $iter;
	
	($start_s, $start_m) = gettimeofday();
	
	redo foo;
}


sub action {
	$count++;
	usleep 100;
}

1; # keep your mother happy

__END__