nanosleep (1000000000);

I think that with a fixed time like that, you'll probably still see a cumulative error if you run it for a longer time, I don't think 5 minutes is enough.

However, I only now realized that I overlooked a solution that should have been staring me in the face: clock_nanosleep(2), which is also provided by Time::HiRes. Try running the following over a longer time (several hours):

use warnings;
use strict;
use Time::HiRes qw/ clock_gettime clock_nanosleep
    CLOCK_REALTIME TIMER_ABSTIME /;
die "Don't have nanosleep" unless Time::HiRes::d_nanosleep();

my $run = 1; $SIG{INT} = sub { $run = 0 };
while ($run) {
    my $now_s = int(clock_gettime(CLOCK_REALTIME));
    clock_nanosleep(CLOCK_REALTIME, ($now_s+1)*1e9, TIMER_ABSTIME);
    last unless $run;
    print clock_gettime(CLOCK_REALTIME), "\n";
}

[download]

In reply to Re^5: The most precise second (timer) by haukex
in thread The most precise second (timer) by tukusejssirs

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.