hi, all monks:
    I try to figure out a walk around for this problem, by
passing the socket descriptor to the worker threads through
unix domain, and here is my experimental scripts:  
the server side script:

#!/usr/bin/perl
# server
 use strict;
 use warnings;

 use threads;
 use IO::Socket::UNIX;
 use IO::Socket::INET;
 use Socket::MsgHdr;

 $| = 1;

 threads->create( \&handleClient )->detach();

 my $listenSocket = IO::Socket::INET->new(
     'LocalPort' => '8888',
     'Listen'    => SOMAXCONN,
     'Reuse'     => 1,
     'Proto'     => 'tcp',
 );

 while ( defined ( my $conSocket = $listenSocket->accept ) ) {
     my $un_ConSocket = IO::Socket::UNIX->new(
         'Type' => SOCK_STREAM,
         'Peer' => '/tmp/undomain',
     );

     my $outMsgHdr = Socket::MsgHdr->new( 'buf' => 'some bytes' );
     $outMsgHdr->cmsghdr( SOL_SOCKET, SCM_RIGHTS,
         pack ( "i", fileno ($conSocket) ) );
     my $sentMsgLen;
     {
         no warnings qw( uninitialized );
         $sentMsgLen = sendmsg( $un_ConSocket, $outMsgHdr );
     }

 } ## end while ( defined ( my $conSocket...


 sub handleClient
 {
     unlink '/tmp/undomain';

     my $listenSocket = IO::Socket::UNIX->new(
         'Type'   => SOCK_STREAM,
         'Local'  => '/tmp/undomain',
         'Listen' => SOMAXCONN,
     );

     my $unConSocket = $listenSocket->accept;
     my $inMsgHdr = Socket::MsgHdr->new( buflen => 128, controllen => 
+256 );
     my $receivedMsgLen;
     {
         no warnings qw( uninitialized );
         $receivedMsgLen = recvmsg( $unConSocket, $inMsgHdr);
     }
     print 'received msg:', $inMsgHdr->buf(), "\n";
     my ( $level, $type, $data ) = $inMsgHdr->cmsghdr();
     my $fileno = unpack ( 'i', $data );

     open ( CLIENTSOCKET, '+<&=' , $fileno );

     while ( my $line = <CLIENTSOCKET> ) {
         print CLIENTSOCKET $line or warn $!;
         print "thread ", threads->tid(), " received line: $line\n";
     }
 } ## end sub handleClient
[download]

The client side script:

#!/usr/bin/perl
# client

 use strict;
 use warnings;

 use IO::Socket;

 $| = 1;

 my $socket = IO::Socket::INET->new(
     'Proto'    => 'tcp',
     'PeerAddr' => '127.0.0.1',
     'PeerPort' => '8888',
 ) or die $@;

 my $msgOut = "hello, server\n";
 while (1) {
     print $socket $msgOut;
     my $msgIn = <$socket>;

     print "client received echo:$msgIn\n";

     sleep 1;
 } ## end while (1)
[download]

It didn't work well, the worker thread only can get the first message from the client, and then hold on

 while ( my $line = <CLIENTSOCKET> ) 

, and the client side also hold on

my $msgIn = <$socket>; 

I can't figure out why they both hold on readline operation.

thx 4 helpping ...