Coro/Event/Event.pm

=head1 NAME

Coro::Event - do events the coro-way

=head1 SYNOPSIS

 use Coro;
 use Coro::Event;

 sub keyboard : Coro {
    my $w = Coro::Event->io(fd => \*STDIN, poll => 'r');
    while() {
       print "cmd> ";
       my $ev = $w->next; my $cmd = <STDIN>;
       unloop unless $cmd ne "";
       print "data> ";
       my $ev = $w->next; my $data = <STDIN>;
    }
 }

 loop;

=head1 DESCRIPTION

This module enables you to create programs using the powerful Event model
(and module), while retaining the linear style known from simple or
threaded programs.

This module provides a method and a function for every watcher type
(I<flavour>) (see L<Event>). The only difference between these and the
watcher constructors from Event is that you do not specify a callback
function - it will be managed by this module.

Your application should just create all necessary coroutines and then call
Coro::Event::loop.

Please note that even programs or modules (such as
L<Coro::Handle|Coro::Handle>) that use "traditional"
event-based/continuation style will run more efficient with this module
then when using only Event.

=head1 WARNING

Please note that Event does not support coroutines or threads. That
means that you B<MUST NOT> block in an event callback. Again: In Event
callbacks, you I<must never ever> call a Coroutine fucntion that blocks
the current coroutine.

While this seems to work superficially, it will eventually cause memory
corruption.

=head1 FUNCTIONS

=over 4

=cut

package Coro::Event;

no warnings;

use Carp;
no warnings;

use Coro;
use Coro::Timer;
use Event qw(loop unloop); # we are re-exporting this, cooool!

use XSLoader;

use base Exporter::;

our @EXPORT = qw(loop unloop sweep);

BEGIN {
   our $VERSION = 1.9;

   local $^W = 0; # avoid redefine warning for Coro::ready;
   XSLoader::load __PACKAGE__, $VERSION;
}

=item $w = Coro::Event->flavour (args...)

Create and return a watcher of the given type.

Examples:

  my $reader = Coro::Event->io(fd => $filehandle, poll => 'r');
  $reader->next;

=cut

=item $w->next

Return the next event of the event queue of the watcher.

=cut

=item do_flavour args...

Create a watcher of the given type and immediately call it's next
method. This is less efficient then calling the constructor once and the
next method often, but it does save typing sometimes.

=cut

for my $flavour (qw(idle var timer io signal)) {
   push @EXPORT, "do_$flavour";
   my $new = \&{"Event::$flavour"};
   my $class = "Coro::Event::$flavour";
   my $type = $flavour eq "io" ? 1 : 0;
   @{"${class}::ISA"} = (Coro::Event::, "Event::$flavour");
   my $coronew = sub {
      # how does one do method-call-by-name?
      # my $w = $class->SUPER::$flavour(@_);

      shift eq Coro::Event::
         or croak "event constructor \"Coro::Event->$flavour\" must be called as a static method";

      my $w = $new->($class,
            desc => $flavour,
            @_,
            parked => 1,
      );
      _install_std_cb($w, $type);
      bless $w, $class; # reblessing due to broken Event
   };
   *{    $flavour } = $coronew;
   *{"do_$flavour"} = sub {
      unshift @_, Coro::Event::;
      my $e = (&$coronew)->next;
      $e->cancel; # $e === $e->w
      $e;
   };
}

# double calls to avoid stack-cloning ;()
# is about 10% slower, though.
sub next($) {
   &Coro::schedule while &_next;

   $_[0]
}

sub Coro::Event::w    { $_[0] }
sub Coro::Event::prio { $_[0]{Coro::Event}[3] }
sub Coro::Event::hits { $_[0]{Coro::Event}[4] }
sub Coro::Event::got  { $_[0]{Coro::Event}[5] }

=item sweep

Similar to Event::one_event and Event::sweep: The idle task is called once
(this has the effect of jumping back into the Event loop once to serve new
events).

The reason this function exists is that you sometimes want to serve events
while doing other work. Calling C<Coro::cede> does not work because
C<cede> implies that the current coroutine is runnable and does not call
into the Event dispatcher.

=cut

sub sweep {
   Event::one_event 0; # for now
}

=item $result = loop([$timeout])

This is the version of C<loop> you should use instead of C<Event::loop>
when using this module - it will ensure correct scheduling in the presence
of events.

=item unloop([$result])

Same as Event::unloop (provided here for your convinience only).

=cut

$Coro::idle = \&Event::one_event; # inefficient

1;

=back

=head1 AUTHOR

 Marc Lehmann <schmorp@schmorp.de>
 http://home.schmorp.de/

=cut

Revision:	1.42
Committed:	Fri Dec 1 02:24:46 2006 UTC (17 years, 7 months ago) by root
Branch:	MAIN
Changes since 1.41:	+16 -4 lines
Log Message:	* empty log message *
#	User	Rev	Content
1	root	1.1	=head1 NAME
2
3			Coro::Event - do events the coro-way
4
5			=head1 SYNOPSIS
6
7			use Coro;
8			use Coro::Event;
9
10			sub keyboard : Coro {
11	pcg	1.21	my $w = Coro::Event->io(fd => \*STDIN, poll => 'r');
12	root	1.1	while() {
13			print "cmd> ";
14			my $ev = $w->next; my $cmd = <STDIN>;
15			unloop unless $cmd ne "";
16			print "data> ";
17			my $ev = $w->next; my $data = <STDIN>;
18			}
19			}
20
21	root	1.8	loop;
22	root	1.1
23			=head1 DESCRIPTION
24
25			This module enables you to create programs using the powerful Event model
26			(and module), while retaining the linear style known from simple or
27			threaded programs.
28
29			This module provides a method and a function for every watcher type
30			(I<flavour>) (see L<Event>). The only difference between these and the
31			watcher constructors from Event is that you do not specify a callback
32			function - it will be managed by this module.
33
34			Your application should just create all necessary coroutines and then call
35	root	1.12	Coro::Event::loop.
36	root	1.1
37	root	1.37	Please note that even programs or modules (such as
38			L<Coro::Handle\|Coro::Handle>) that use "traditional"
39			event-based/continuation style will run more efficient with this module
40			then when using only Event.
41
42	root	1.42	=head1 WARNING
43
44			Please note that Event does not support coroutines or threads. That
45			means that you B<MUST NOT> block in an event callback. Again: In Event
46			callbacks, you I<must never ever> call a Coroutine fucntion that blocks
47			the current coroutine.
48
49			While this seems to work superficially, it will eventually cause memory
50			corruption.
51
52			=head1 FUNCTIONS
53
54	root	1.1	=over 4
55
56			=cut
57
58			package Coro::Event;
59
60	root	1.42	no warnings;
61	root	1.1
62			use Carp;
63	root	1.30	no warnings;
64	root	1.1
65			use Coro;
66	root	1.40	use Coro::Timer;
67	root	1.8	use Event qw(loop unloop); # we are re-exporting this, cooool!
68	root	1.1
69	root	1.30	use XSLoader;
70	root	1.1
71	root	1.30	use base Exporter::;
72
73	root	1.41	our @EXPORT = qw(loop unloop sweep);
74	root	1.1
75	root	1.2	BEGIN {
76	root	1.35	our $VERSION = 1.9;
77	root	1.2
78	root	1.13	local $^W = 0; # avoid redefine warning for Coro::ready;
79	root	1.30	XSLoader::load __PACKAGE__, $VERSION;
80	root	1.2	}
81	root	1.1
82	root	1.42	=item $w = Coro::Event->flavour (args...)
83	root	1.1
84			Create and return a watcher of the given type.
85
86			Examples:
87
88			my $reader = Coro::Event->io(fd => $filehandle, poll => 'r');
89			$reader->next;
90
91			=cut
92
93			=item $w->next
94
95			Return the next event of the event queue of the watcher.
96
97			=cut
98
99	root	1.42	=item do_flavour args...
100	root	1.1
101			Create a watcher of the given type and immediately call it's next
102			method. This is less efficient then calling the constructor once and the
103			next method often, but it does save typing sometimes.
104
105			=cut
106
107			for my $flavour (qw(idle var timer io signal)) {
108			push @EXPORT, "do_$flavour";
109			my $new = \&{"Event::$flavour"};
110			my $class = "Coro::Event::$flavour";
111	root	1.2	my $type = $flavour eq "io" ? 1 : 0;
112	root	1.1	@{"${class}::ISA"} = (Coro::Event::, "Event::$flavour");
113			my $coronew = sub {
114			# how does one do method-call-by-name?
115			# my $w = $class->SUPER::$flavour(@_);
116
117	root	1.10	shift eq Coro::Event::
118	root	1.1	or croak "event constructor \"Coro::Event->$flavour\" must be called as a static method";
119
120	root	1.10	my $w = $new->($class,
121	root	1.1	desc => $flavour,
122			@_,
123	root	1.2	parked => 1,
124	root	1.1	);
125	root	1.2	_install_std_cb($w, $type);
126	root	1.1	bless $w, $class; # reblessing due to broken Event
127			};
128			*{ $flavour } = $coronew;
129			*{"do_$flavour"} = sub {
130			unshift @_, Coro::Event::;
131			my $e = (&$coronew)->next;
132	pcg	1.20	$e->cancel; # $e === $e->w
133	root	1.1	$e;
134			};
135			}
136
137	root	1.2	# double calls to avoid stack-cloning ;()
138	root	1.3	# is about 10% slower, though.
139	root	1.2	sub next($) {
140	root	1.41	&Coro::schedule while &_next;
141
142			$_[0]
143	root	1.1	}
144	root	1.2
145	root	1.4	sub Coro::Event::w { $_[0] }
146	root	1.5	sub Coro::Event::prio { $_[0]{Coro::Event}[3] }
147			sub Coro::Event::hits { $_[0]{Coro::Event}[4] }
148			sub Coro::Event::got { $_[0]{Coro::Event}[5] }
149	root	1.1
150			=item sweep
151
152			Similar to Event::one_event and Event::sweep: The idle task is called once
153			(this has the effect of jumping back into the Event loop once to serve new
154			events).
155
156			The reason this function exists is that you sometimes want to serve events
157			while doing other work. Calling C<Coro::cede> does not work because
158			C<cede> implies that the current coroutine is runnable and does not call
159			into the Event dispatcher.
160
161			=cut
162
163			sub sweep {
164	root	1.42	Event::one_event 0; # for now
165	root	1.1	}
166
167			=item $result = loop([$timeout])
168
169			This is the version of C<loop> you should use instead of C<Event::loop>
170			when using this module - it will ensure correct scheduling in the presence
171			of events.
172
173			=item unloop([$result])
174
175			Same as Event::unloop (provided here for your convinience only).
176
177			=cut
178
179	root	1.40	$Coro::idle = \&Event::one_event; # inefficient
180	root	1.9
181	root	1.1	1;
182
183	root	1.36	=back
184
185	root	1.1	=head1 AUTHOR
186
187	root	1.27	Marc Lehmann <schmorp@schmorp.de>
188	root	1.25	http://home.schmorp.de/
189	root	1.1
190			=cut
191