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Comparing AnyEvent/lib/AnyEvent.pm (file contents):
Revision 1.102 by root, Sun Apr 27 21:16:26 2008 UTC vs.
Revision 1.104 by root, Wed Apr 30 11:40:22 2008 UTC

… …
390 390
391 AnyEvent::Impl::CoroEV based on Coro::EV, best choice. 391 AnyEvent::Impl::CoroEV based on Coro::EV, best choice.
392 AnyEvent::Impl::CoroEvent based on Coro::Event, second best choice. 392 AnyEvent::Impl::CoroEvent based on Coro::Event, second best choice.
393 AnyEvent::Impl::EV based on EV (an interface to libev, best choice). 393 AnyEvent::Impl::EV based on EV (an interface to libev, best choice).
394 AnyEvent::Impl::Event based on Event, second best choice. 394 AnyEvent::Impl::Event based on Event, second best choice.
395 AnyEvent::Impl::Perl pure-perl implementation, fast and portable.
395 AnyEvent::Impl::Glib based on Glib, third-best choice. 396 AnyEvent::Impl::Glib based on Glib, third-best choice.
396 AnyEvent::Impl::Perl pure-perl implementation, inefficient but portable.
397 AnyEvent::Impl::Tk based on Tk, very bad choice. 397 AnyEvent::Impl::Tk based on Tk, very bad choice.
398 AnyEvent::Impl::Qt based on Qt, cannot be autoprobed (see its docs). 398 AnyEvent::Impl::Qt based on Qt, cannot be autoprobed (see its docs).
399 AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse. 399 AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
400 AnyEvent::Impl::POE based on POE, not generic enough for full support. 400 AnyEvent::Impl::POE based on POE, not generic enough for full support.
401 401
… …
553my @models = ( 553my @models = (
554 [Coro::EV:: => AnyEvent::Impl::CoroEV::], 554 [Coro::EV:: => AnyEvent::Impl::CoroEV::],
555 [Coro::Event:: => AnyEvent::Impl::CoroEvent::], 555 [Coro::Event:: => AnyEvent::Impl::CoroEvent::],
556 [EV:: => AnyEvent::Impl::EV::], 556 [EV:: => AnyEvent::Impl::EV::],
557 [Event:: => AnyEvent::Impl::Event::], 557 [Event:: => AnyEvent::Impl::Event::],
558 [Glib:: => AnyEvent::Impl::Glib::],
559 [Tk:: => AnyEvent::Impl::Tk::], 558 [Tk:: => AnyEvent::Impl::Tk::],
560 [Wx:: => AnyEvent::Impl::POE::], 559 [Wx:: => AnyEvent::Impl::POE::],
561 [Prima:: => AnyEvent::Impl::POE::], 560 [Prima:: => AnyEvent::Impl::POE::],
562 [AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::], 561 [AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::],
563 # everything below here will not be autoprobed as the pureperl backend should work everywhere 562 # everything below here will not be autoprobed as the pureperl backend should work everywhere
563 [Glib:: => AnyEvent::Impl::Glib::],
564 [Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy 564 [Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
565 [Qt:: => AnyEvent::Impl::Qt::], # requires special main program 565 [Qt:: => AnyEvent::Impl::Qt::], # requires special main program
566 [POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza 566 [POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
567); 567);
568 568
… …
1071file descriptor is dup()ed for each watcher. This shows that the dup() 1071file descriptor is dup()ed for each watcher. This shows that the dup()
1072employed by some adaptors is not a big performance issue (it does incur a 1072employed by some adaptors is not a big performance issue (it does incur a
1073hidden memory cost inside the kernel which is not reflected in the figures 1073hidden memory cost inside the kernel which is not reflected in the figures
1074above). 1074above).
1075 1075
1076C<POE>, regardless of underlying event loop (whether using its pure 1076C<POE>, regardless of underlying event loop (whether using its pure perl
1077perl select-based backend or the Event module, the POE-EV backend 1077select-based backend or the Event module, the POE-EV backend couldn't
1078couldn't be tested because it wasn't working) shows abysmal performance 1078be tested because it wasn't working) shows abysmal performance and
1079and memory usage: Watchers use almost 30 times as much memory as 1079memory usage with AnyEvent: Watchers use almost 30 times as much memory
1080EV watchers, and 10 times as much memory as Event (the high memory 1080as EV watchers, and 10 times as much memory as Event (the high memory
1081requirements are caused by requiring a session for each watcher). Watcher 1081requirements are caused by requiring a session for each watcher). Watcher
1082invocation speed is almost 900 times slower than with AnyEvent's pure perl 1082invocation speed is almost 900 times slower than with AnyEvent's pure perl
1083implementation.
1084
1083implementation. The design of the POE adaptor class in AnyEvent can not 1085The design of the POE adaptor class in AnyEvent can not really account
1084really account for this, as session creation overhead is small compared 1086for the performance issues, though, as session creation overhead is
1085to execution of the state machine, which is coded pretty optimally within 1087small compared to execution of the state machine, which is coded pretty
1086L<AnyEvent::Impl::POE>. POE simply seems to be abysmally slow. 1088optimally within L<AnyEvent::Impl::POE> (and while everybody agrees that
1089using multiple sessions is not a good approach, especially regarding
1090memory usage, even the author of POE could not come up with a faster
1091design).
1087 1092
1088=head3 Summary 1093=head3 Summary
1089 1094
1090=over 4 1095=over 4
1091 1096
… …
1170 1175
1171=head3 Summary 1176=head3 Summary
1172 1177
1173=over 4 1178=over 4
1174 1179
1175=item * The pure perl implementation performs extremely well, considering 1180=item * The pure perl implementation performs extremely well.
1176that it uses select.
1177 1181
1178=item * Avoid Glib or POE in large projects where performance matters. 1182=item * Avoid Glib or POE in large projects where performance matters.
1179 1183
1180=back 1184=back
1181 1185
… …
1230 1234
1231 1235
1232=head1 FORK 1236=head1 FORK
1233 1237
1234Most event libraries are not fork-safe. The ones who are usually are 1238Most event libraries are not fork-safe. The ones who are usually are
1235because they are so inefficient. Only L<EV> is fully fork-aware. 1239because they rely on inefficient but fork-safe C<select> or C<poll>
1240calls. Only L<EV> is fully fork-aware.
1236 1241
1237If you have to fork, you must either do so I<before> creating your first 1242If you have to fork, you must either do so I<before> creating your first
1238watcher OR you must not use AnyEvent at all in the child. 1243watcher OR you must not use AnyEvent at all in the child.
1239 1244
1240 1245

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