The document discusses POE (Perl Object Environment), which is a framework for building event-driven and concurrent applications in Perl. It describes POE's architecture which includes sessions, kernels, wheels, and components. It provides examples of creating POE sessions and using wheels and components to interface with files and IRC. POE allows building multithreaded and networked applications using an event-driven model with inter-session communication.

1. POE
Stefano Rodighiero
OpenExp 2006

2. Perl
Object
Environment
POE - A Perl Object Environment

3. ?
POE - A Perl Object Environment

4. Framework
POE - A Perl Object Environment

5. Event
driven
POE - A Perl Object Environment

6. Multitasking
Cooperativo
POE - A Perl Object Environment

7. Single
thread
POE - A Perl Object Environment

8. Networking
POE - A Perl Object Environment

9. System
administration
POE - A Perl Object Environment

10. GUI
POE - A Perl Object Environment

11. POE - A Perl Object Environment

12. Component
Wheel
“Architettura”
Session
Kernel
POE - A Perl Object Environment

13. Component
Wheel
Dispatch di eventi
Session
Kernel
POE - A Perl Object Environment

14. Component
Wheel
Risponde agli eventi
Session
Kernel
POE - A Perl Object Environment

15. Component
“Plugin” per sessioni,
incapsula insiemi di
Wheel
gestori di eventi
Session POE::Wheel::FollowTail
POE::Wheel::Run
Kernel
POE - A Perl Object Environment

16. Component
Wheel POE::Component::IRC
POE::Component::Server::TCP
POE::Component::Server::SimpleHTTP
…CPAN…
Session
Kernel
POE - A Perl Object Environment

17. POE - A Perl Object Environment

18. Un programma tipico
• Istanzia una o più sessioni
• Esplicitamente, eventualmente usando
delle Wheel
• Implicitamente, con Componenti già
pronti
• POE::Kernel->run()
POE - A Perl Object Environment

19. sub POE::Kernel::TRACE_EVENTS() { 1 }
POE - A Perl Object Environment

20. use POE;
POE - A Perl Object Environment

21. for ( 1 .. 3 ) {
POE::Session -> create(
inline_states => {
_start => sub { print quot;Start!nquot; },
_stop => sub { print quot;Stop!nquot; }
} );
}
POE - A Perl Object Environment

22. POE::Kernel->run();
POE - A Perl Object Environment

23. _start
Session
Kernel
POE - A Perl Object Environment

24. _start
Session
_start =>
sub {
print quot;Start!nquot;
Kernel
}
POE - A Perl Object Environment

25. Passaggio di messaggi
Accoda un evento, da inoltrare
post() alla session specificata
Accoda un evento, da inoltrare
yield() alla session stessa
Invoca - in maniera
sincrona - un evento per una
call()
sessione specificata
POE - A Perl Object Environment

26. Passaggio di messaggi
post()/yield()
POE - A Perl Object Environment

27. Passaggio di messaggi
call()
POE - A Perl Object Environment

28. Comunicazione
tra sessioni
POE - A Perl Object Environment

29. # Sessione Babbo Natale
POE::Session->create(
inline_states => {
_start => sub {
print quot;Oh oh oh!nquot;;
$poe_kernel->alias_set( quot;Santaquot; );
},
lettera => sub {
print quot;Lettera da quot;
. $poe_kernel->alias_list( $_[SENDER] );
}
}
);
POE - A Perl Object Environment

30. # Sessione Babbo Natale
POE::Session->create(
inline_states => {
_start => sub {
print quot;Oh oh oh!nquot;;
$poe_kernel->alias_set( quot;Santaquot; );
},
lettera => sub {
print quot;Lettera da quot;
. $poe_kernel->alias_list( $_[SENDER] );
}
}
);
POE - A Perl Object Environment

31. # Sessione Babbo Natale
POE::Session->create(
inline_states => {
_start => sub {
print quot;Oh oh oh!nquot;;
$poe_kernel->alias_set( quot;Santaquot; );
},
lettera => sub {
print quot;Lettera da quot;
. $poe_kernel->alias_list( $_[SENDER] );
}
}
);
POE - A Perl Object Environment

32. # Sessione Babbo Natale
POE::Session->create(
inline_states => {
_start => sub {
print quot;Oh oh oh!nquot;;
$poe_kernel->alias_set( quot;Santaquot; );
},
lettera => sub {
print quot;Lettera da quot;
. $poe_kernel->alias_list( $_[SENDER] );
}
}
);
POE - A Perl Object Environment

33. # Sessione bimbo
POE::Session->create(
inline_states => {
_start => sub {
$poe_kernel->alias_set( quot;Paolinoquot; );
$poe_kernel->post( quot;Santaquot; => 'lettera' );
},
}
);
POE - A Perl Object Environment

34. # Sessione bimbo
POE::Session->create(
inline_states => {
_start => sub {
$poe_kernel->alias_set( quot;Paolinoquot; );
$poe_kernel->post( quot;Santaquot; => 'lettera' );
},
}
);
POE - A Perl Object Environment

35. Babbo Natale _start
Kernel
Paolino
_start
POE - A Perl Object Environment

36. Babbo Natale
Kernel
Paolino
post( quot;Santaquot;, quot;letteraquot; )
POE - A Perl Object Environment

37. lettera
Babbo Natale
Kernel
Paolino
POE - A Perl Object Environment

38. lettera
Babbo Natale
lettera
Kernel
Paolino
post( quot;Santaquot;, quot;letteraquot; )
POE - A Perl Object Environment

39. POE - A Perl Object Environment

40. Wheel
POE - A Perl Object Environment

41. Insiemi di
gestori di
eventi
POE - A Perl Object Environment

42. POE::
Wheel::
FollowTail
POE - A Perl Object Environment

43. use POE qw(
Wheel::FollowTail
);
POE - A Perl Object Environment

44. $|++
POE - A Perl Object Environment

45. POE::Session-create(
inline_states = {...
POE - A Perl Object Environment

46. _start = sub {
my $heap = $_[ HEAP ];
my $watcher = POE::Wheel::FollowTail-new(
Filename = 'logfile.log',
PollInterval = 1,
InputEvent = 'input_state'
);
$heap-{ watcher } = $watcher;
} , ...
POE - A Perl Object Environment

47. _start = sub {
my $heap = $_[ HEAP ];
my $watcher = POE::Wheel::FollowTail-new(
Filename = 'logfile.log',
PollInterval = 1,
InputEvent = 'input_state'
);
$heap-{ watcher } = $watcher;
} , ...
POE - A Perl Object Environment

48. _start = sub {
my $heap = $_[ HEAP ];
my $watcher = POE::Wheel::FollowTail-new(
Filename = 'logfile.log',
PollInterval = 1,
InputEvent = 'input_state'
);
$heap-{ watcher } = $watcher;
} , ...
POE - A Perl Object Environment

49. _start = sub {
my $heap = $_[ HEAP ];
my $watcher = POE::Wheel::FollowTail-new(
Filename = 'logfile.log',
PollInterval = 1,
InputEvent = 'input_state'
);
$heap-{ watcher } = $watcher;
} , ...
POE - A Perl Object Environment

50. _start = sub {
my $heap = $_[ HEAP ];
my $watcher = POE::Wheel::FollowTail-new(
Filename = 'logfile.log',
PollInterval = 1,
InputEvent = 'input_state'
);
$heap-{ watcher } = $watcher;
} , ...
POE - A Perl Object Environment

51. input_state = sub {
my $input = $_[ ARG0 ];
print $input;
}
POE - A Perl Object Environment

52. Session
__________
__________
__________
__________
__________
__________
Wheel
POE - A Perl Object Environment

53. Session
__________
__________
__________
input_event
__________
__________
__________
Wheel
POE - A Perl Object Environment

54. POE - A Perl Object Environment

55. POE
+ Test
+ IRC
POE - A Perl Object Environment

56. Testing?
POE - A Perl Object Environment

57. Failed 3/10
tests
?
Test IRC
POE - A Perl Object Environment

58. 09:41 Quinn larsen: Avast!
Whoreson swab!
You failed 3/10 tests!
POE - A Perl Object Environment

59. ?
Test IRC
POE - A Perl Object Environment

60. Session
POE::
Wheel::
__________ FollowTail
__________
__________
__________
__________
__________
POE::
Component::
IRC
POE - A Perl Object Environment

61. POE::
Component::
IRC
POE - A Perl Object Environment

62. use POE qw/ Wheel::FollowTail
Component::IRC
/;
POE - A Perl Object Environment

63. use Acme::Scurvy::Whoreson::BilgeRat;
POE - A Perl Object Environment

64. my $conf = {
nick = 'Quinn',
ircname = 'HAR!',
server = 'irc.freenode.net',
port = 6667
};
my $channel = '#scummbar';
POE - A Perl Object Environment

65. my $irc = POE::Component::IRC-spawn( %$conf )
or die quot;HAR!!! $!quot;;
POE - A Perl Object Environment

66. POE::Session-create(
package_states = [
'main' = [ qw(
_default
_start
irc_001
irc_public
tell_results
) ],
],
heap = { irc = $irc }
);
POE - A Perl Object Environment

67. POE::Session-create(
package_states = [
'main' = [ qw(
_default
_start
irc_001
irc_public
tell_results
) ],
],
heap = { irc = $irc }
);
POE - A Perl Object Environment

68. POE::Session-create(
package_states = [
'main' = [ qw(
_default
_start
irc_001
irc_public
tell_results
) ],
],
heap = { irc = $irc }
);
POE - A Perl Object Environment

69. sub _start {
my ( $kernel, $heap ) = @_[ KERNEL, HEAP ];
my $watcher = POE::Wheel::FollowTail-new(
Filename = 'tests.log' ,
PollInterval = 1 ,
InputEvent = 'tell_results'
);
$heap-{ watcher } = $watcher;
my $irc_sess = $heap-{irc}-session_id();
$kernel-post( $irc_sess = register = 'all' );
$kernel-post( $irc_sess = connect = {} );
undef;
}
POE - A Perl Object Environment

70. sub _start {
my ( $kernel, $heap ) = @_[ KERNEL, HEAP ];
my $watcher = POE::Wheel::FollowTail-new(
Filename = 'tests.log' ,
PollInterval = 1 ,
InputEvent = 'tell_results'
);
$heap-{ watcher } = $watcher;
my $irc_sess = $heap-{irc}-session_id();
$kernel-post( $irc_sess = register = 'all' );
$kernel-post( $irc_sess = connect = {} );
undef;
}
POE - A Perl Object Environment

71. sub _start {
my ( $kernel, $heap ) = @_[ KERNEL, HEAP ];
my $watcher = POE::Wheel::FollowTail-new(
Filename = 'tests.log' ,
PollInterval = 1 ,
InputEvent = 'tell_results'
);
$heap-{ watcher } = $watcher;
my $irc_sess = $heap-{irc}-session_id();
$kernel-post( $irc_sess = register = 'all' );
$kernel-post( $irc_sess = connect = {} );
undef;
}
POE - A Perl Object Environment

72. sub irc_001 {
my ( $kernel, $sender ) =
@_[ KERNEL, SENDER ];
$kernel-post(
$sender = join = $channel );
undef;
}
POE - A Perl Object Environment

73. sub tell_results
{
my $kernel = $_[KERNEL];
my $heap = $_[HEAP];
my $line = $_[ARG0];
my $irc_session = $heap-{irc};
my ($failed, $total) = split qr|/|, $line;
if ($failed) {
my $insult = Acme::Scurvy::Whoreson::BilgeRat-new(
language = 'pirate'
);
$kernel-post(
$irc_session = privmsg =
$channel = quot;$insult! You failed $failed tests!quot; );
}
}
}
POE - A Perl Object Environment

74. sub tell_results
{
my $kernel = $_[KERNEL];
my $heap = $_[HEAP];
my $line = $_[ARG0];
my $irc_session = $heap-{irc};
my ($failed, $total) = split qr|/|, $line;
if ($failed) {
my $insult = Acme::Scurvy::Whoreson::BilgeRat-new(
language = 'pirate'
);
$kernel-post(
$irc_session = privmsg =
$channel = quot;$insult! You failed $failed tests!quot; );
}
}
}
POE - A Perl Object Environment

75. sub tell_results
{
my $kernel = $_[KERNEL];
my $heap = $_[HEAP];
my $line = $_[ARG0];
my $irc_session = $heap-{irc};
my ($failed, $total) = split qr|/|, $line;
if ($failed) {
my $insult = Acme::Scurvy::Whoreson::BilgeRat-new(
language = 'pirate'
);
$kernel-post(
$irc_session = privmsg =
$channel = quot;$insult! You failed $failed tests!quot; );
}
}
}
POE - A Perl Object Environment

76. POE - A Perl Object Environment

77. • irc.freenode.net,#poe
• http://poe.perl.org
• “Advanced Perl
Programming” (O’Reilly) - Cap.7
• http://del.icio.us/slr/poe ☺
POE - A Perl Object Environment

78. • http://www.perl.it
• irc.freenode.net,#perl.it
• mongers@perl.it
POE - A Perl Object Environment

79. Grazie!
Stefano Rodighiero
larsen@perl.it