Re: Handling multiple clients (use threads)

[BrowserUk]

Provided that you create the threads before loading your data, a threaded server works fine. Only the main thread has a copy of the large volume of data, whilst sharing the requests and replies with the server threads through shared memory (Thread::Queue):

#! perl -slw
use strict;
use IO::Socket;
use threads qw[ yield ];
use threads::shared;
use Thread::Queue;
$| = 1;

our $THREADS ||= 5;

my $listening : shared = 0;

our $ios = IO::Socket::INET->new(
    LocalPort    => 6969,
    Type        => &IO::Socket::SOCK_STREAM,
    Proto        => 'tcp',
    Reuse        => 1,
    Listen        => 100,
) or die "IO::S->new failed with $!";
    
print "$ios";

sub server {
    $listening++;
    
    my( $Qquery, $Qreply ) = @_;
    my $tid = threads->self->tid;
    print "tid:$tid";

    ## Give th other threads a chance to get up and running.
    yield until $listening == $THREADS;
    
    while( my $client = $ios->accept() ) {
        chomp( my $query = <$client> );
#        print "$tid: $client got: '$query'";
        $Qquery->enqueue( "$tid:$query" );
        my $reply = $Qreply->dequeue();
        print $client $reply;        
        close $client;
    }
    $listening--;
}

my @Qs = map{ new Thread::Queue } 0 .. $THREADS;
threads->new( \&server, $Qs[ 0 ], $Qs[ $_ ] )->detach for 1 .. $THREAD
+S;

yield until $listening == $THREADS;

print "Threads $listening running; grabbing data";

open BIGFILE, '< :raw', 'data/50MB.dat' or die "data/50mb.dat: $!";
my $data;
sysread( BIGFILE, $data, -s( BIGFILE ) ) or die "sysread BIGFILE : $!"
+;
close BIGFILE;

while( $listening ) {
    my( $tid, $msg ) = split ':', $Qs[ 0 ]->dequeue();
    ## Process request
    print "Received '$msg' from $tid";
    $Qs[ $tid ]->enqueue( 'Thankyou for your enquiry' );
}

Partial server log

__END__
P:\test>388547 -THREADS=10
IO::Socket::INET=GLOB(0x197f1ac)
tid:1
tid:2
tid:3
tid:4
tid:5
tid:6
tid:9
tid:8
tid:7
tid:10
Threads 10 running; grabbing data
Received 'Why don't you call me anymore?' from 10
Received 'Why don't you call me anymore?' from 1
Received 'Why don't you call me anymore?' from 2
Received 'Why don't you call me anymore?' from 3
Received 'Why don't you call me anymore?' from 4
Received 'Why don't you call me anymore?' from 5
Received 'Why don't you call me anymore?' from 6
Received 'Why don't you call me anymore?' from 9
Received 'Why don't you call me anymore?' from 8
Received 'Why don't you call me anymore?' from 7
Received 'Why don't you call me anymore?' from 10
Received 'Why don't you call me anymore?' from 1
Received 'Why don't you call me anymore?' from 2
Received 'Why don't you call me anymore?' from 3
Received 'Why don't you call me anymore?' from 4
Received 'Why don't you call me anymore?' from 5
Received 'Why don't you call me anymore?' from 6
Received 'Why don't you call me anymore?' from 9
Received 'Why don't you call me anymore?' from 8
Received 'Why don't you call me anymore?' from 7
Received 'Why don't you call me anymore?' from 10
Received 'Why don't you call me anymore?' from 1
Received 'Why don't you call me anymore?' from 2
Received 'Why don't you call me anymore?' from 3
Received 'Why don't you call me anymore?' from 4
Received 'Why don't you call me anymore?' from 5
Received 'Why don't you call me anymore?' from 6
Received 'Why don't you call me anymore?' from 9

Client:

#! perl -slw
use strict;
use IO::Socket;

my $socket = IO::Socket::INET->new(
    PeerAddr => '127.0.0.1',
    PeerPort => 6969,
    Proto    => "tcp",
    Type     => SOCK_STREAM
) or die "Couldn't connect to 127.0.0.1:6969 : $@";

# ... do something with the socket
print $socket "Why don't you call me anymore?";

chomp( my $answer = <$socket> );

print "Got: $answer";

# and terminate the connection when we're done
close($socket);

__END__
for /l %i in (1,1,30) do @start /b SockClient
Got: Thankyou for your enquiry
Got: Thankyou for your enquiry
Got: Thankyou for your enquiry
Got: Thankyou for your enquiry
Got: Thankyou for your enquiry
Got: Thankyou for your enquiry
Got: Thankyou for your enquiry
Got: Thankyou for your enquiry
Got: Thankyou for your enquiry
Got: Thankyou for your enquiry
Got: Thankyou for your enquiry
Got: Thankyou for your enquiry
Got: Thankyou for your enquiry
Got: Thankyou for your enquiry
Got: Thankyou for your enquiry
Got: Thankyou for your enquiry
Got: Thankyou for your enquiry

P:\test>Got: Thankyou for your enquiry
Got: Thankyou for your enquiry
Got: Thankyou for your enquiry
Got: Thankyou for your enquiry
Got: Thankyou for your enquiry
Got: Thankyou for your enquiry
Got: Thankyou for your enquiry
Got: Thankyou for your enquiry
Got: Thankyou for your enquiry
Got: Thankyou for your enquiry
Got: Thankyou for your enquiry
Got: Thankyou for your enquiry
Got: Thankyou for your enquiry

As is, the server doesn't contain any mechanism for shutting it down, but ^C works okay and a SIGINT handler could deal with cleanup if required.

[jalewis2]

Thanks to everyone that replied. I think I misunderstood what exactly the fork was doing in relation to what I wanted to accomplish.

I am going to give BroswerUK's code a try.

Thanks again for the quick response.