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Revision 1.42 by root, Mon Apr 7 19:40:12 2008 UTC vs.
Revision 1.49 by root, Mon Apr 14 19:11:15 2008 UTC

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18 18
19 my $w = AnyEvent->condvar; # stores wether a condition was flagged 19 my $w = AnyEvent->condvar; # stores wether a condition was flagged
20 $w->wait; # enters "main loop" till $condvar gets ->broadcast 20 $w->wait; # enters "main loop" till $condvar gets ->broadcast
21 $w->broadcast; # wake up current and all future wait's 21 $w->broadcast; # wake up current and all future wait's
22 22
23=head1 WHY YOU SHOULD USE THIS MODULE 23=head1 WHY YOU SHOULD USE THIS MODULE (OR NOT)
24 24
25Glib, POE, IO::Async, Event... CPAN offers event models by the dozen 25Glib, POE, IO::Async, Event... CPAN offers event models by the dozen
26nowadays. So what is different about AnyEvent? 26nowadays. So what is different about AnyEvent?
27 27
28Executive Summary: AnyEvent is I<compatible>, AnyEvent is I<free of 28Executive Summary: AnyEvent is I<compatible>, AnyEvent is I<free of
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57model>, AnyEvent also is free of bloat and policy: with POE or similar 57model>, AnyEvent also is free of bloat and policy: with POE or similar
58modules, you get an enourmous amount of code and strict rules you have 58modules, you get an enourmous amount of code and strict rules you have
59to follow. AnyEvent, on the other hand, is lean and to the point by only 59to follow. AnyEvent, on the other hand, is lean and to the point by only
60offering the functionality that is useful, in as thin as a wrapper as 60offering the functionality that is useful, in as thin as a wrapper as
61technically possible. 61technically possible.
62
63Of course, if you want lots of policy (this can arguably be somewhat
64useful) and you want to force your users to use the one and only event
65model, you should I<not> use this module.
62 66
63 67
64=head1 DESCRIPTION 68=head1 DESCRIPTION
65 69
66L<AnyEvent> provides an identical interface to multiple event loops. This 70L<AnyEvent> provides an identical interface to multiple event loops. This
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175=item $cv->wait 179=item $cv->wait
176 180
177Wait (blocking if necessary) until the C<< ->broadcast >> method has been 181Wait (blocking if necessary) until the C<< ->broadcast >> method has been
178called on c<$cv>, while servicing other watchers normally. 182called on c<$cv>, while servicing other watchers normally.
179 183
180Not all event models support a blocking wait - some die in that case, so
181if you are using this from a module, never require a blocking wait, but
182let the caller decide wether the call will block or not (for example,
183by coupling condition variables with some kind of request results and
184supporting callbacks so the caller knows that getting the result will not
185block, while still suppporting blockign waits if the caller so desires).
186
187You can only wait once on a condition - additional calls will return 184You can only wait once on a condition - additional calls will return
188immediately. 185immediately.
186
187Not all event models support a blocking wait - some die in that case
188(programs might want to do that so they stay interactive), so I<if you
189are using this from a module, never require a blocking wait>, but let the
190caller decide wether the call will block or not (for example, by coupling
191condition variables with some kind of request results and supporting
192callbacks so the caller knows that getting the result will not block,
193while still suppporting blocking waits if the caller so desires).
194
195Another reason I<never> to C<< ->wait >> in a module is that you cannot
196sensibly have two C<< ->wait >>'s in parallel, as that would require
197multiple interpreters or coroutines/threads, none of which C<AnyEvent>
198can supply (the coroutine-aware backends C<Coro::EV> and C<Coro::Event>
199explicitly support concurrent C<< ->wait >>'s from different coroutines,
200however).
189 201
190=item $cv->broadcast 202=item $cv->broadcast
191 203
192Flag the condition as ready - a running C<< ->wait >> and all further 204Flag the condition as ready - a running C<< ->wait >> and all further
193calls to C<wait> will return after this method has been called. If nobody 205calls to C<wait> will return after this method has been called. If nobody
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248 260
249 AnyEvent::Impl::CoroEV based on Coro::EV, best choice. 261 AnyEvent::Impl::CoroEV based on Coro::EV, best choice.
250 AnyEvent::Impl::EV based on EV (an interface to libev, also best choice). 262 AnyEvent::Impl::EV based on EV (an interface to libev, also best choice).
251 AnyEvent::Impl::CoroEvent based on Coro::Event, second best choice. 263 AnyEvent::Impl::CoroEvent based on Coro::Event, second best choice.
252 AnyEvent::Impl::Event based on Event, also second best choice :) 264 AnyEvent::Impl::Event based on Event, also second best choice :)
253 AnyEvent::Impl::Glib based on Glib, second-best choice. 265 AnyEvent::Impl::Glib based on Glib, third-best choice.
254 AnyEvent::Impl::Tk based on Tk, very bad choice. 266 AnyEvent::Impl::Tk based on Tk, very bad choice.
255 AnyEvent::Impl::Perl pure-perl implementation, inefficient. 267 AnyEvent::Impl::Perl pure-perl implementation, inefficient but portable.
256 268
257=item AnyEvent::detect 269=item AnyEvent::detect
258 270
259Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model if 271Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model if
260necessary. You should only call this function right before you would have 272necessary. You should only call this function right before you would have
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630 642
6311. Blocking: 6431. Blocking:
632 644
633 my $data = $fcp->client_get ($url); 645 my $data = $fcp->client_get ($url);
634 646
6352. Blocking, but parallelizing: 6472. Blocking, but running in parallel:
636 648
637 my @datas = map $_->result, 649 my @datas = map $_->result,
638 map $fcp->txn_client_get ($_), 650 map $fcp->txn_client_get ($_),
639 @urls; 651 @urls;
640 652
641Both blocking examples work without the module user having to know 653Both blocking examples work without the module user having to know
642anything about events. 654anything about events.
643 655
6443a. Event-based in a main program, using any support Event module: 6563a. Event-based in a main program, using any supported event module:
645 657
646 use Event; 658 use EV;
647 659
648 $fcp->txn_client_get ($url)->cb (sub { 660 $fcp->txn_client_get ($url)->cb (sub {
649 my $txn = shift; 661 my $txn = shift;
650 my $data = $txn->result; 662 my $data = $txn->result;
651 ... 663 ...
652 }); 664 });
653 665
654 Event::loop; 666 EV::loop;
655 667
6563b. The module user could use AnyEvent, too: 6683b. The module user could use AnyEvent, too:
657 669
658 use AnyEvent; 670 use AnyEvent;
659 671
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666 678
667 $quit->wait; 679 $quit->wait;
668 680
669=head1 SEE ALSO 681=head1 SEE ALSO
670 682
671Event modules: L<Coro::Event>, L<Coro>, L<Event>, L<Glib::Event>, L<Glib>. 683Event modules: L<Coro::EV>, L<EV>, L<EV::Glib>, L<Glib::EV>,
684L<Coro::Event>, L<Event>, L<Glib::Event>, L<Glib>, L<Coro>, L<Tk>.
672 685
673Implementations: L<AnyEvent::Impl::Coro>, L<AnyEvent::Impl::Event>, L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>. 686Implementations: L<AnyEvent::Impl::CoroEV>, L<AnyEvent::Impl::EV>,
687L<AnyEvent::Impl::CoroEvent>, L<AnyEvent::Impl::Event>,
688L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>.
674 689
675Nontrivial usage example: L<Net::FCP>. 690Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>.
676 691
677=head1 692=head1
678 693
679=cut 694=cut
680 695

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