come out of the polling with a new client socket in a can read state
nonsense. They all (or just some of them) come out of the polling with the listening socket in can read state. Poll/epoll/select don't return any new sockets, for that workers have to call accept, which will return connection only to one worker. 
use 5.010;
use strict;
use warnings;

use IO::Socket::INET;
use IO::Poll;
use Time::HiRes;

my $port = shift // 7777;
my $sock = IO::Socket::INET->new(LocalPort => $port, Listen => 10);
$sock->blocking(0);

for ( 1 .. 3 ) {
    my $pid = fork;
    unless ($pid) {
        my $poll = IO::Poll->new;
        $poll->mask( $sock => POLLIN );
        while ( $poll->poll >= 0 ) {
            say "$$ got out of poll";
            my $cli = $sock->accept;
            if ($cli) {
                say "$$ accepted connection from " . $cli->peerport;
                print while <$cli>;
                exit 0;
            }
            else {
                say "$$ got nothing from accept";
            }
        }
    }
}
__END__
4367 got out of poll
4367 accepted connection from 58442
4365 got out of poll
4366 got out of poll
4366 got nothing from accept
4365 accepted connection from 58446

[download]
As you can see when there's an incoming connection, poll may return in several workers, but only one worker can accept the connection.

In reply to Re^12: Help designing a threaded service by zwon
in thread Help designing a threaded service by Tommy

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.