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->main.

=over 4

=cut

package Coro::Event;

no warnings;

use Carp;

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

use base 'Exporter';

@EXPORT = qw(loop unloop sweep reschedule);

BEGIN {
   $VERSION = 0.45;

   require XSLoader;
   XSLoader::load Coro::Event, $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(@_);

      $_[0] eq Coro::Event::
         or croak "event constructor \"Coro::Event->$flavour\" must be called as a static method";

      my $q = []; # [$coro, $event]
      my $w = $new->(
            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 if &_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 {
   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.

=begin comment

Unlike loop's counterpart it is not an error when no watchers are active -
loop silently returns in this case, as if unloop(undef) were called.

=end comment

=cut

sub loop(;$) {
   local $Coro::idle = $Coro::current;
   Coro::schedule; # become idle task, which is implicitly ready
   &Event::loop;
}

=item unloop([$result])

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

=cut

$Coro::idle = new Coro sub {
   while () {
      Event::one_event; # inefficient
      Coro::schedule;
   }
};

1;

=head1 AUTHOR

 Marc Lehmann <pcg@goof.com>
 http://www.goof.com/pcg/marc/

=cut

Revision:	1.5
Committed:	Sat Aug 18 02:58:38 2001 UTC (22 years, 9 months ago) by root
Branch:	MAIN
Changes since 1.4:	+4 -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			my $w = Coro::Event->io(fd => *STDIN, poll => 'r');
12			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			&loop;
22
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			Coro::Event->main.
36
37			=over 4
38
39			=cut
40
41			package Coro::Event;
42
43			no warnings;
44
45			use Carp;
46
47			use Coro;
48			use Event qw(unloop); # we are re-exporting this, cooool!
49
50			use base 'Exporter';
51
52	root	1.5	@EXPORT = qw(loop unloop sweep reschedule);
53	root	1.1
54	root	1.2	BEGIN {
55			$VERSION = 0.45;
56
57			require XSLoader;
58			XSLoader::load Coro::Event, $VERSION;
59			}
60	root	1.1
61			=item $w = Coro::Event->flavour(args...)
62
63			Create and return a watcher of the given type.
64
65			Examples:
66
67			my $reader = Coro::Event->io(fd => $filehandle, poll => 'r');
68			$reader->next;
69
70			=cut
71
72			=item $w->next
73
74			Return the next event of the event queue of the watcher.
75
76			=cut
77
78			=item do_flavour(args...)
79
80			Create a watcher of the given type and immediately call it's next
81			method. This is less efficient then calling the constructor once and the
82			next method often, but it does save typing sometimes.
83
84			=cut
85
86			for my $flavour (qw(idle var timer io signal)) {
87			push @EXPORT, "do_$flavour";
88			my $new = \&{"Event::$flavour"};
89			my $class = "Coro::Event::$flavour";
90	root	1.2	my $type = $flavour eq "io" ? 1 : 0;
91	root	1.1	@{"${class}::ISA"} = (Coro::Event::, "Event::$flavour");
92			my $coronew = sub {
93			# how does one do method-call-by-name?
94			# my $w = $class->SUPER::$flavour(@_);
95
96			$_[0] eq Coro::Event::
97			or croak "event constructor \"Coro::Event->$flavour\" must be called as a static method";
98
99			my $q = []; # [$coro, $event]
100			my $w = $new->(
101			desc => $flavour,
102			@_,
103	root	1.2	parked => 1,
104	root	1.1	);
105	root	1.2	_install_std_cb($w, $type);
106	root	1.1	bless $w, $class; # reblessing due to broken Event
107			};
108			*{ $flavour } = $coronew;
109			*{"do_$flavour"} = sub {
110			unshift @_, Coro::Event::;
111			my $e = (&$coronew)->next;
112	root	1.4	$e->cancel; # $e = $e->w
113	root	1.1	$e;
114			};
115			}
116
117	root	1.2	# double calls to avoid stack-cloning ;()
118	root	1.3	# is about 10% slower, though.
119	root	1.2	sub next($) {
120	root	1.3	&Coro::schedule if &_next; $_[0];
121	root	1.1	}
122	root	1.2
123	root	1.4	sub Coro::Event::w { $_[0] }
124	root	1.5	sub Coro::Event::prio { $_[0]{Coro::Event}[3] }
125			sub Coro::Event::hits { $_[0]{Coro::Event}[4] }
126			sub Coro::Event::got { $_[0]{Coro::Event}[5] }
127	root	1.1
128			=item sweep
129
130			Similar to Event::one_event and Event::sweep: The idle task is called once
131			(this has the effect of jumping back into the Event loop once to serve new
132			events).
133
134			The reason this function exists is that you sometimes want to serve events
135			while doing other work. Calling C<Coro::cede> does not work because
136			C<cede> implies that the current coroutine is runnable and does not call
137			into the Event dispatcher.
138
139			=cut
140
141			sub sweep {
142			one_event(0); # for now
143			}
144
145			=item $result = loop([$timeout])
146
147			This is the version of C<loop> you should use instead of C<Event::loop>
148			when using this module - it will ensure correct scheduling in the presence
149			of events.
150
151			=begin comment
152
153			Unlike loop's counterpart it is not an error when no watchers are active -
154			loop silently returns in this case, as if unloop(undef) were called.
155
156			=end comment
157
158			=cut
159
160			sub loop(;$) {
161			local $Coro::idle = $Coro::current;
162			Coro::schedule; # become idle task, which is implicitly ready
163			&Event::loop;
164			}
165
166			=item unloop([$result])
167
168			Same as Event::unloop (provided here for your convinience only).
169
170			=cut
171
172			$Coro::idle = new Coro sub {
173			while () {
174			Event::one_event; # inefficient
175			Coro::schedule;
176			}
177			};
178
179			1;
180
181			=head1 AUTHOR
182
183			Marc Lehmann <pcg@goof.com>
184			http://www.goof.com/pcg/marc/
185
186			=cut
187