Re^11: Help designing a threaded service

There's a difference between being notified about new connection and accepting it.

OKay. So all of these identical workers are sitting polling, poll/epoll/select/whatever, and when a new client connects, exactly one of them will come out of the polling with a new client socket in a can read state, and all the others will get a polite note slipped under their doors informing them of the event.

Do please think before pedanting.

With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday'

Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.

"Science is about questioning the status quo. Questioning authority".

In the absence of evidence, opinion is indistinguishable from prejudice.

Comment on Re^11: Help designing a threaded service

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Re^12: Help designing a threaded service by zwon (Abbot) on Jan 28, 2014 at 15:03 UTC
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.	[reply] [d/l]

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Re^12: Help designing a threaded service
by zwon (Abbot) on Jan 28, 2014 at 15:03 UTC

come out of the polling with a new client socket in a can read state

listening

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]

[reply]
[d/l]