I use the regular Parallel::ForkManager module in Perl. I execute around 10 children processes. 'passes_thresholds' function take few milliseconds or nanoseconds (checked it). In case i run all processes one by one (without Parallel::ForkManager) the whole process took 80-250 milliseconds. In case i run them as parallel, the whole process takes at lease 1 second. I found that the Fork spend 1 second to start the 'finish' function. I put a timer when the child process finished his job and should go to 'finish' function. One second is too much for my development. 
sub parallel_execute {
    my $this = shift;
    foreach my $a (@a_array) {
        my $pid = $this->{fork_manager}->start and next;
        my $res = $a->passes_thresholds();
        $a->{timer} = Benchmark::Timer->new();
        $svc->{timer}->start;
        $this->{fork_manager}->finish(0,{a => $a, plugin_result => $re
+s});
    }
}

$this->{fork_manager}->run_on_finish( sub {
    my ($pid, $exit_code, $ident, $exit_signal, $core_dump, $data_stru
+cture_reference) = @_;
    my $a = $data_structure_reference->{a};
    if (exists $a->{timer}) {
        $a->{timer}->stop;
        debug "took: " . $a->{timer}->report;
    }
});

[download]
Do you have any idea why it took at least 1 second to start the 'finish' command? (I am using Unix server, and perl 5.10)

In reply to Parallel::ForkManager takes too much time to start 'finish' function by ohadk

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.