use 5.14.0;
use warnings;

use Time::HiRes qw( ualarm gettimeofday usleep );

my $delay = 100_000; # us

my $x = 0;
sub foo {
    my $duration = rand 1200; # Some will be longer than the max duration

    my ($sec, $msec) = gettimeofday;
    printf "%4d %12d.%03d %6d\n", $x++, $sec, int ($msec / 1000), $duration;
    vec (my $v, 13, 1) = 0;
    select ($v, $v, $v, $duration / 10000.);
    } # foo

my $running = 0;
$SIG{ALRM} = sub {

    ualarm ($delay);

    unless ($running) {
	$running = 1;
	foo ();
	$running = 0;
	}
    };

ualarm (10);
usleep (10) while 1;