Thanks for your reply!
I'm a little confused...
1st of all, yes, my "threads" could be renamed to children processes, sorry :)

The $SIG{CHLD} is called when a child process has finished, so we can retrieve its exit($result) using waitpid() and put the $result into the $status{$pid} hash.

use POSIX ":sys_wait_h";

$SIG{'CHLD'} = \&REAPER;  # manage moribound children
sub REAPER {
  my $pid = 0;

  while (($pid = waitpid(-1, &WNOHANG)) > 0) { $status{$pid} = $?; }

  $SIG{'CHLD'} = \&REAPER;
}
[download]

The $threads decrement is done in the &timer_online, comparing the $status $pid with the client's pid list.


If you launch the 2nd portion of code (the fake "scan"), everything is running fine, the parent gets the finished child's $result using the &REAPER routine.

Here's a simple code:

use strict;
use POSIX ":sys_wait_h";

$SIG{'CHLD'} = \&REAPER;

sub REAPER {
  my $pid = 0;

  while (($pid = waitpid(-1, &WNOHANG)) > 0) {
    print STDOUT "$pid returned $?\n";
  }

  $SIG{'CHLD'} = \&REAPER;
}

sub new_thread {
  my $result = 0;

  if (my $pid = fork()) {
    return($pid);
  }

  $result = 1;

  exit($result);
}

my $child = &new_thread();
print STDOUT "got a new child: $child\n";

for (;;) {}

1;
[download]

This way we can retrieve the $result.

If this works fine without the select() and vec() socket management, why are the fork()'s processes problematic when using them?


The simple complete code mixing them:

use strict;
use POSIX ":sys_wait_h";
use IO::Socket::INET;

$SIG{'CHLD'} = \&REAPER;

sub REAPER {
  my $pid = 0;

  while (($pid = waitpid(-1, &WNOHANG)) > 0) {
    print STDOUT "$pid returned $?\n";
  }

  $SIG{'CHLD'} = \&REAPER;
}

sub new_thread {
  my $result = 0;

  if (my $pid = fork()) {
    return($pid);
  }

  sleep(3);

  $result = 1;

  exit($result);
}

my %socklist = (); # hash table of sockets
my $bit = '';

# connect to the IRC server
my $socket = &open_socket("tcp", "irc.creatixnet.com", 6667, 3);

sub open_socket {
  my ($proto, $host, $port, $timeout) = (shift, shift, shift, shift);

  my $socket = IO::Socket::INET->new(
    Proto => $proto,
    PeerAddr => $host,
    PeerPort => $port,
    Timeout => $timeout
  );

  if (!$socket) { return(0); }
  return($socket);
}

if (!$socket) { die("can't connect"); }

&add_socket($socket, "IRC");

sub add_socket {
  my ($socket, $type) = (shift, shift);

  $socket->autoflush(1);

  $socklist{$socket}{'sock'} = $socket;
  $socklist{$socket}{'type'} = $type;
  $socklist{$socket}{'fileno'} = $socket->fileno();

  vec($bit, $socklist{$socket}{'fileno'}, 1) = 1;

  return(0);
}

print $socket "USER zxf sdf sdf sdf\n";
print $socket "NICK sdfsdfg\n";
print $socket "JOIN #fx\n";

my $child = &new_thread();
print STDOUT "got a new child: $child\n";

sub loop_socket {
  my $rin = $bit; $rin =~ /[^\0]/ || next;
  my $idx = select($rin, undef, undef, 1);
  my $buffer = "";

  $idx || next;
  $idx > 0 || die($!);

  my %list = %socklist;

  while ($idx && (my ($socket, $value) = each(%list))) {
    $socket = $value->{'sock'};

    if (vec($rin, $value->{'fileno'}, 1)) { $buffer = <$socket>; print
+ STDOUT "IRC: $buffer"; }
  }

  return(0);
}

for (;;) {
  &loop_socket();
}

1;
[download]

When children exits: No children at test.txt line 82

:(
Cheers