Pass a IO::Socket handle to a thread

[bsdmeister]

Hi,

I am a newbie in Perl, used it only to work with strings in the past, but now I am doing a MSc work that makes massive usage of threads and sockets.

My goal is to pass a socket handle to a thread, so the thread can recv data.

I have read something about shared objects (where IO::Socket is not available to pass). Is there a way to pass a socket handle to a thread?

I create the socket:

    $server = IO::Socket::INET->new(
              LocalAddr=>'localhost',
              LocalPort=>$port,
              Type=>SOCK_STREAM,
              Proto=>'tcp',
              Listen=>10
              );

sub protocol($server)
{
    while(1)
    {
        if ($server->connected())
        {
            print "Socket is here :)";
        }
        $server->recv($data,1024);
        @recvData = split(/:/,$data);
        print $data;        
        print $recvData;    
    }
}

while(1)
{
    print "UP\n";
    $server->accept();
    print $server->connected();
    $p = threads->create(\&protocol => $server);

}

[BrowserUk]

Your problem is that you are trying to use perl as if it was C.

This:

sub protocol($srv) {

Does not declare a function that takes a single argument called $srv.

You need to learn how to use perl before you start playing with threads; otherwise you will just blame threading for your own mistakes.

You should start by reading perlsub and writing some simple (non-threaded!) programs that use subroutines and pass arguments.

Once you understand how to pass arguments and what "prototypes" are, you may be ready to progress to the next level.

[zentara]

I don't know about the code you posted, but to pass a handle to a thread, use the fileno of the handle.

# some pseudo code

my $fileno = fileno($fh);
threads->create( \&thread, $fileno )->detach;

sub thread{
  my( $fileno ) = @_;

open my $fh, ">&=$fileno" or warn $! and die;

print $fh  "thread# ",threads->tid()," ->  $fileno \n"  ;

}

[Anonymous Monk]

threads + sockets stalling question shows fileno isn't required

[Anonymous Monk]

I don't know :) seems to me you're passing a socket when you spawn/create a thread, no sharing required

 [thread socket] thread socket -> threads + sockets stalling question, Multithreaded Socket Listener -> Simple threaded chat server

[bsdmeister]

I am passing full code here, I changed it thousands of times without success, my goal is quite simple, just read data from the socket inside the thread

#!/usr/bin/perl
use Getopt::Long;
use IO::Socket::INET;
use threads;
use threads::shared;
#-------------------------------------------------
# BEGIN: Variables Declaration
#-------------------------------------------------
my @replicas;

#-------------------------------------------------
# END: Variables Declaration
#-------------------------------------------------

#-------------------------------------------------
# BEGIN: Command Line Processing
#-------------------------------------------------

$parameters = GetOptions("leader=s" => \$type,
             "malicious=s" => \$state);

#-------------------------------------------------
# END: Command Line Processing
#-------------------------------------------------

#-------------------------------------------------
# BEGIN: Socket Server Startup and Checks
#-------------------------------------------------
$connected = 0;

if ($type == "TRUE")
{
    $port = 9000;
}

my $server;

while ($connected == 0)
{
    $server = IO::Socket::INET->new(
              LocalAddr=>'localhost',
              LocalPort=>$port,
              Type=>SOCK_STREAM,
              Proto=>'tcp',
              Listen=>10
              );
    if ($server)
    {
        print("SERVER: BIND to PORT $port SUCCESFULL\n");
        $connected = 1;
        #if ($type != "TRUE")
        #{
            
    }
    else
    {
        print("SERVER: CANNOT BIND to PORT $port \n");
        $port++;
        print("SERVER: NEW PORT $port \n");
    }
}
$replica = "localhost:$port";
push(@replicas, $replica);

#-------------------------------------------------
# END: Socket Server Startup and Checks
#-------------------------------------------------

#-------------------------------------------------
# BEGIN: ServerControl Thread
#-------------------------------------------------
sub serverControl($time)
{
    while (1)
    {
        print "LISTENING \n";
        print @replicas;
        foreach $replica ($replicas)
        {
            print $replica;
            if ($replica != "localhost:$port")
            {
                @repl = split(/:/,$replica);
                print $repl;
                $clientServerControl = IO::Socket::INET->new(
                               PeerAddr=>'localhost',
                               PeerPort=>$repl[1],
                               Proto   =>'tcp'
                               );
                if ($clientServerControl)
                {
                    $keepAlive = "UP:localhost:$replica[1]:ENDUP";
                    $clientServerControl->send($keepAlive);
                    $answer = <$socket>;
                    print $answer;
                }
                else
                {
                    @replicas = grep { $_ != $replica } @replicas;
                }
                close($clientServerControl);
            }
            
        }    
        sleep(2);
    }
}

#-------------------------------------------------
# END: ServerControl Thread
#-------------------------------------------------

#-------------------------------------------------
# BEGIN: Protocol Thread
#-------------------------------------------------


sub protocol($srv)
{
    
    while(1)
    {
    #    if ($srv->connected())
    #    {
            print "Socket is here :)";
            $srv->recv($data,1024);
            @recvData = split(/:/,$data);
            if ($data)
            {
                print "-----> $data";        
            }
            print $recvData;    
    #    }
        
    }
}

print "aqui";


$t = threads->create('serverControl');
print $type;
if ($type eq "FALSE")
{
    $notifyLeader = IO::Socket::INET->new(
                PeerAddr=>'localhost',
                PeerPort=>9000,
                Proto   =>'tcp'
                )
    or die("LEADER is Offline");
    $notify = "ENTER-VIEW:localhost:$port";
    print $notify;
    if ($notifyLeader->send($notify))
    {
        print "Mensagem enviada... \n";
    }
        
    close($notifyLeader);
}
    

while(1)
{
    print "UP\n";
    $client = $server->accept();
    $p = threads->create(\&protocol,$client);

}

[CountZero]

Always

use strict;
use warnings;

It will avoid silly typos and assist you to find other bugs as well.

Hint 1: check your if tests. There is a big difference between == and eq.

Hint 2: forget the subroutine prototypes. They don't do what you think they do.

[Anonymous Monk]

Also, you should read perlintro and use eq to compare strings

[Anonymous Monk]

That doesn't compile

$ perl -Mdiagnostics -e " sub serverControl($time) { } "
Illegal character in prototype for main::serverControl : $time at -e l
+ine 1 (#1)
    (W illegalproto) An illegal character was found in a prototype dec
+laration.
    Legal characters in prototypes are $, @, %, *, ;, [, ], &, \, and 
++.