src/lib/Bcd/Clients/ClientsListeners.pm

   1 package Bcd::Clients::ClientsListeners;
   2
   3 # This file is part of the breadcrumbs daemon (bcd).
   4 # Copyright (C) 2007 Pasqualino Ferrentino
   5
   6 # This program is free software; you can redistribute it and/or modify
   7 # it under the terms of the GNU General Public License as published by
   8 # the Free Software Foundation; either version 2 of the License, or
   9 # (at your option) any later version.
  10
  11 # This program is distributed in the hope that it will be useful, but
  12 # WITHOUT ANY WARRANTY; without even the implied warranty of
  13 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14 # General Public License for more details.
  15
  16 # You should have received a copy of the GNU General Public License
  17 # along with this program; if not, write to the Free Software
  18 # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  19 # 02110-1301, USA.
  20
  21 # Contact: lino.ferrentino@yahoo.it (in Italian, English or German).
  22
  23 #this file contains the set of the listeners in our program.
  24 #each listener is in its own thread.
  25
  26 #this file is a singleton.
  27
  28 use strict;
  29 use warnings;
  30 use Class::Singleton;
  31
  32 use Bcd::Clients::Listener;
  33
  34 use vars qw(@ISA);
  35 @ISA = qw(Class::Singleton);
  36 use constant EOL => "\015\012";
  37
  38 use constant{
  39     # Some constants to initialize the number of threads in this program...
  40     INITAL_LISTENERS => 10,
  41     MAX_LISTENERS => 20,
  42 };
  43
  44 sub _new_instance{
  45     my ($class, $script) = @_;
  46
  47     my $self = {};
  48
  49     bless ($self, $class);
  50
  51     $self->_create_the_listeners($script);
  52
  53     #this is the hash which has the clients which must be closed...
  54     $self->{"clients"} = {};
  55
  56     return $self;
  57 }
  58
  59 sub _create_the_listeners{
  60
  61     my ($self, $script) = @_;
  62
  63     #if you want the script you have only one listener...
  64     my @listeners;
  65
  66     my $listeners_num;
  67
  68     if ($script == 1) {
  69         $listeners_num = 1;
  70     } else {
  71         $listeners_num = INITAL_LISTENERS;
  72     }
  73
  74     for ( my $i = 0 ; $i < $listeners_num ; ++$i){
  75         #ok, let's create them
  76
  77         my $listener = Bcd::Clients::Listener->new($script);
  78         push (@listeners, $listener);
  79     }
  80
  81     $self->{"listeners"} = \@listeners;
  82 }
  83
  84 #this function is called whenever a new client wants to talk to the
  85 #daemon.  this function can blocks the incoming client because we have
  86 #not reasource available to serve it
  87 sub a_new_client_has_arrived{
  88
  89     my ($self, $client) = @_;
  90
  91     #ok, let's try to get a free listener for this client
  92     my $served = 0;
  93
  94     while (!$served){
  95         for (my $i = 0 ; $i < INITAL_LISTENERS ; ++$i){
  96             if ($self->{"listeners"}[$i]->try_to_serve_this_client($client) == 0){
  97                 #ok... I am able to go on
  98                 $served = 1;
  99                 last;
 100             }
 101         }
 102
 103         if (!$served){
 104             print $client "BCD busy, please wait..." . EOL;
 105             sleep(2);
 106         }
 107     }
 108 }
 109
 110 1;