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);

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

#sub std_cb {
#   my $w = $_[0]->w;
#   my $q = $w->private;
#   $q->[1] = $_[0];
#   if ($q->[0]) { # somebody waiting?
#      $q->[0]->ready;
#      &Coro::schedule;
#   } else {
#      $w->stop;
#   }
#}

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->w->cancel;
      $e;
   };
}

# double calls to avoid stack-cloning ;()
# is about 20% slower, though.
sub next($) {
   &_next0;
   &Coro::schedule;
   &_next1;
}

#sub next {
#   my $w = $_[0];
#   my $q = $w->private;
#   if ($q->[1]) { # event waiting?
#      $w->again unless $w->is_cancelled;
#   } elsif ($q->[0]) {
#      croak "only one coroutine can wait for an event";
#   } else {
#      local $q->[0] = $Coro::current;
#      &Coro::schedule;
#   }
#   pop @$q;
#}

sub Coro::Event::Ev::w    { $_[0][2] }
sub Coro::Event::Ev::got  { $_[0][3] }
sub Coro::Event::Ev::prio { croak "prio not supported yet, please mail to pcg\@goof.com" }
sub Coro::Event::Ev::hits { croak "prio not supported yet, please mail to pcg\@goof.com" }

=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:	1.2
Committed:	Fri Aug 17 01:45:39 2001 UTC (22 years, 10 months ago) by root
Branch:	MAIN
Changes since 1.1:	+45 -31 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			@EXPORT = qw(loop unloop sweep);
53
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	root	1.2	#sub std_cb {
87			# my $w = $_[0]->w;
88			# my $q = $w->private;
89			# $q->[1] = $_[0];
90			# if ($q->[0]) { # somebody waiting?
91			# $q->[0]->ready;
92			# &Coro::schedule;
93			# } else {
94			# $w->stop;
95			# }
96			#}
97	root	1.1
98			for my $flavour (qw(idle var timer io signal)) {
99			push @EXPORT, "do_$flavour";
100			my $new = \&{"Event::$flavour"};
101			my $class = "Coro::Event::$flavour";
102	root	1.2	my $type = $flavour eq "io" ? 1 : 0;
103	root	1.1	@{"${class}::ISA"} = (Coro::Event::, "Event::$flavour");
104			my $coronew = sub {
105			# how does one do method-call-by-name?
106			# my $w = $class->SUPER::$flavour(@_);
107
108			$_[0] eq Coro::Event::
109			or croak "event constructor \"Coro::Event->$flavour\" must be called as a static method";
110
111			my $q = []; # [$coro, $event]
112			my $w = $new->(
113			desc => $flavour,
114			@_,
115	root	1.2	parked => 1,
116	root	1.1	);
117	root	1.2	_install_std_cb($w, $type);
118	root	1.1	bless $w, $class; # reblessing due to broken Event
119			};
120			*{ $flavour } = $coronew;
121			*{"do_$flavour"} = sub {
122			unshift @_, Coro::Event::;
123			my $e = (&$coronew)->next;
124			$e->w->cancel;
125			$e;
126			};
127			}
128
129	root	1.2	# double calls to avoid stack-cloning ;()
130			# is about 20% slower, though.
131			sub next($) {
132			&_next0;
133			&Coro::schedule;
134			&_next1;
135	root	1.1	}
136	root	1.2
137			#sub next {
138			# my $w = $_[0];
139			# my $q = $w->private;
140			# if ($q->[1]) { # event waiting?
141			# $w->again unless $w->is_cancelled;
142			# } elsif ($q->[0]) {
143			# croak "only one coroutine can wait for an event";
144			# } else {
145			# local $q->[0] = $Coro::current;
146			# &Coro::schedule;
147			# }
148			# pop @$q;
149			#}
150
151			sub Coro::Event::Ev::w { $_[0][2] }
152			sub Coro::Event::Ev::got { $_[0][3] }
153			sub Coro::Event::Ev::prio { croak "prio not supported yet, please mail to pcg\@goof.com" }
154			sub Coro::Event::Ev::hits { croak "prio not supported yet, please mail to pcg\@goof.com" }
155	root	1.1
156			=item sweep
157
158			Similar to Event::one_event and Event::sweep: The idle task is called once
159			(this has the effect of jumping back into the Event loop once to serve new
160			events).
161
162			The reason this function exists is that you sometimes want to serve events
163			while doing other work. Calling C<Coro::cede> does not work because
164			C<cede> implies that the current coroutine is runnable and does not call
165			into the Event dispatcher.
166
167			=cut
168
169			sub sweep {
170			one_event(0); # for now
171			}
172
173			=item $result = loop([$timeout])
174
175			This is the version of C<loop> you should use instead of C<Event::loop>
176			when using this module - it will ensure correct scheduling in the presence
177			of events.
178
179			=begin comment
180
181			Unlike loop's counterpart it is not an error when no watchers are active -
182			loop silently returns in this case, as if unloop(undef) were called.
183
184			=end comment
185
186			=cut
187
188			sub loop(;$) {
189			local $Coro::idle = $Coro::current;
190			Coro::schedule; # become idle task, which is implicitly ready
191			&Event::loop;
192			}
193
194			=item unloop([$result])
195
196			Same as Event::unloop (provided here for your convinience only).
197
198			=cut
199
200			$Coro::idle = new Coro sub {
201			while () {
202			Event::one_event; # inefficient
203			Coro::schedule;
204			}
205			};
206
207			1;
208
209			=head1 AUTHOR
210
211			Marc Lehmann <pcg@goof.com>
212			http://www.goof.com/pcg/marc/
213
214			=cut
215