How to share sockets between threads

Anonymous Monk has asked for the wisdom of the Perl Monks concerning the following question:

I am trying to create a server that will transfer messages from one client to the other. In order to do that I need to keep a list of client sockets. I am using threads::shared, and every time I try to &share() the new clients socket, I get an error message that you cannot share globs yet.

Is there any way around this?

use threads;
use threads::shared;
use IO::Socket;

my $server = new IO::Socket::INET(LocalHost => 'localhost', 
                                  LocalPort => 3333,
                                  Proto     => 'tcp', 
                                  Listen    => SOMAXCONN, 
                                  Reuse     => 1);

my %CLIENTS  : shared = ();
my $clientID : shared = 0;

while( my $newClient = $server->accept ) {
    $clientID++;
    $CLIENTS{$clientID} = &share($newClient);  #<--Error

    print "hCLIENT: " . $CLIENTS{$clientID} . "\n"
}
[download]

I know that POE is an alternative, but I would like to use threads instead.

Thanks, Bill

Code tags added by GrandFather

2006-05-10 Retitled by planetscape, as per Monastery guidelines: one-word (or module-only) titles pose a hazard to site navigation

( keep:0 edit:8 reap:0 )

Original title: 'threads::shared'

Comment on How to share sockets between threads Download Code

Replies are listed 'Best First'.
Re: How to share sockets between threads by renodino (Curate) on May 10, 2006 at 15:24 UTC
You don't show how you intend to use threads, so I'll assume you're going to spawn N worker threads, and pass the sockets to them as needed via a Thread::Queue object. GLOB's can't be threads::shared, and aren't scalars, so they can't be passed over Thread::Queue (which is just a threads::shared array). However, you can get the fileno of the socket after accept()'ing, and pass it to the worker instead: (The following code hasn't been tested, its just an outline) `my $thrdq = Thread::Queue->new(); my @thrds = (); push @thrds, threads->new(\&runworker) foreach (1..$num_of_threads); while( my $newClient = $server->accept ) { $thrdq->enqueue(fileno($newClient)); } sub runworker { my $sktno = $thrdq->dequeue(); my $client = IO::Socket::INET->new(); $client->fdopen($fn, '+>>'); print $client "CLIENT: some stuff\n" }` [download] IIRC, you'll also need to wait for the work thread to pick up the fileno before accepting another connection, or the master may cause a socket close when it accepts the next connection.	[reply] [d/l]
Re: How to share sockets between threads by Anonymous Monk on May 10, 2006 at 04:47 UTC
I forgot to add, I am using Windows XP with Perl 5.8.8	[reply]
Re^2: How to share sockets between threads by earlati2 (Beadle) on May 10, 2006 at 07:20 UTC
substitute the line: $CLIENTS{$clientID} = &share($newClient); as show belowe ( put $newClient inside braket square ) $CLIENTS{$clientID} = &share([$newClient]); I test it on a win2000 with perl 5.8.7 and it works	[reply]
Re^3: How to share sockets between threads by BrowserUk (Patriarch) on May 10, 2006 at 08:04 UTC
This doesn't work. It prevents the error message, but what it actually does is Creates an anonymous array containing the glob. It then shares the anonymous array--but when you share an array, all its contents are silently discarded! `use threads; use threads::shared;; use IO::Socket::INET;; $sock = IO::Socket::INET->new( 'localhost:12345' );; $ref = &share( [ $sock ] );; print $ref;; ARRAY(0x2253c8) print $#$ref;; -1 #### The anonymous array is EMPTY!` [download] Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error. Lingua non convalesco, consenesco et abolesco. -- Rule 1 has a caveat! -- Who broke the cabal? "Science is about questioning the status quo. Questioning authority". In the absence of evidence, opinion is indistinguishable from prejudice.	[reply] [d/l]