use strict;
use warnings;

use Time::HiRes ;

my $secs_old = 1;     
my $usecs_old = 0.000001;
my $sleep_amt = 1;

for (1..100_000){
    my ($secs_new, $usecs_new) = Time::HiRes::gettimeofday();
    
    my $secs_diff = $secs_new - $secs_old - $sleep_amt;
    my $usecs_diff = $usecs_new - $usecs_old;
    
    $usecs_diff = $usecs_diff / 1000;
    
    print "[$secs_diff] [$usecs_diff]\n";
    
    $secs_old = $secs_new;
    $usecs_old = $usecs_new;
    
    #Time::HiRes::usleep(1_000_000);    #I found usleep tends to have even less accurate results than the builtin sleep function...
    sleep $sleep_amt;
}

__END__

[0] [0]
[0] [15.625]
[0] [0]
....
[0] [0]
[0] [15.625]
[0] [0]
[0] [0]
[0] [0]
[0] [0]
[0] [265.625]
[0] [0]
[0] [0]
...
etc