Vigilantes de Grupo

El Programa

En el siguiente ejemplo, el vigilante $group monitoriza un watcher de entrada/salida y un reloj. Si ninguno de ellos actúa en un periodo de tiempo el manejador del vigilante del grupo es invocado.

pp2@nereida:~/src/perl/Event$ cat -n groupwatchers.pl
 1  #!/usr/bin/perl
 2  use warnings;
 3  use strict;
 4
 5  use Event qw{loop unloop};
 6  require Event::group;
 7
 8  my $io = Event->io(
 9    fd => \*STDIN,
10    cb => sub {
11      warn "IO event here\n";
12      <STDIN>;
13    },
14  );
15
16  my $timer = Event->timer(
17    interval => 1,
18    cb => sub {
19      $_[0]->w->interval($_[0]->w->interval+1);
20      warn "Timer event here, next call in ",$_[0]->w->interval," seconds.\n";
21    },
22  );
23
24  my $group = Event->group(
25    add => $io,
26    timeout => 5,
27    cb => sub {
28      warn "Action detected. ".$_[0]->hits()." hits\n";
29    },
30  );
31
32  $group->add($timer);
33
34  loop;

Ejecución

Puesto que el reloj aumenta su periodo con cada ejecución y no tecleo nada por pantalla eventualmente llega el momento en el que el manejador del grupo es invocado.

pp2@nereida:~/src/perl/Event$ ./groupwatchers.pl
Timer event here, next call in 2 seconds.
Timer event here, next call in 3 seconds.
Timer event here, next call in 4 seconds.
Timer event here, next call in 5 seconds.
Action detected. 1 hits
Timer event here, next call in 6 seconds.
Action detected. 1 hits
Timer event here, next call in 7 seconds.
Action detected. 1 hits
Timer event here, next call in 8 seconds.
Action detected. 1 hits
Timer event here, next call in 9 seconds.
Action detected. 1 hits

Tecleando inhibimos la ejecución del manejador del grupo:

Veamos
IO event here
VeTimer event here, next call in 10 seconds.
amos
IO event here
Veamos
IO event here
Veamos
IO event here
Veamos
IO event here
Timer event here, next call in 11 seconds.
Action detected. 1 hits
^C