… | |
… | |
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 | |
… | |
… | |
553 | my @models = ( |
553 | my @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 | |
… | |
… | |
1071 | file descriptor is dup()ed for each watcher. This shows that the dup() |
1071 | file descriptor is dup()ed for each watcher. This shows that the dup() |
1072 | employed by some adaptors is not a big performance issue (it does incur a |
1072 | employed by some adaptors is not a big performance issue (it does incur a |
1073 | hidden memory cost inside the kernel which is not reflected in the figures |
1073 | hidden memory cost inside the kernel which is not reflected in the figures |
1074 | above). |
1074 | above). |
1075 | |
1075 | |
1076 | C<POE>, regardless of underlying event loop (whether using its pure |
1076 | C<POE>, regardless of underlying event loop (whether using its pure perl |
1077 | perl select-based backend or the Event module, the POE-EV backend |
1077 | select-based backend or the Event module, the POE-EV backend couldn't |
1078 | couldn't be tested because it wasn't working) shows abysmal performance |
1078 | be tested because it wasn't working) shows abysmal performance and |
1079 | and memory usage: Watchers use almost 30 times as much memory as |
1079 | memory usage with AnyEvent: Watchers use almost 30 times as much memory |
1080 | EV watchers, and 10 times as much memory as Event (the high memory |
1080 | as EV watchers, and 10 times as much memory as Event (the high memory |
1081 | requirements are caused by requiring a session for each watcher). Watcher |
1081 | requirements are caused by requiring a session for each watcher). Watcher |
1082 | invocation speed is almost 900 times slower than with AnyEvent's pure perl |
1082 | invocation speed is almost 900 times slower than with AnyEvent's pure perl |
|
|
1083 | implementation. |
|
|
1084 | |
1083 | implementation. The design of the POE adaptor class in AnyEvent can not |
1085 | The design of the POE adaptor class in AnyEvent can not really account |
1084 | really account for this, as session creation overhead is small compared |
1086 | for the performance issues, though, as session creation overhead is |
1085 | to execution of the state machine, which is coded pretty optimally within |
1087 | small compared to execution of the state machine, which is coded pretty |
1086 | L<AnyEvent::Impl::POE>. POE simply seems to be abysmally slow. |
1088 | optimally within L<AnyEvent::Impl::POE> (and while everybody agrees that |
|
|
1089 | using multiple sessions is not a good approach, especially regarding |
|
|
1090 | memory usage, even the author of POE could not come up with a faster |
|
|
1091 | design). |
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. |
1176 | that 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 | |
… | |
… | |
1210 | speed most when you have lots of watchers, not when you only have a few of |
1214 | speed most when you have lots of watchers, not when you only have a few of |
1211 | them). |
1215 | them). |
1212 | |
1216 | |
1213 | EV is again fastest. |
1217 | EV is again fastest. |
1214 | |
1218 | |
1215 | The C-based event loops Event and Glib come in second this time, as the |
1219 | Perl again comes second. It is noticably faster than the C-based event |
1216 | overhead of running an iteration is much smaller in C than in Perl (little |
1220 | loops Event and Glib, although the difference is too small to really |
1217 | code to execute in the inner loop, and perl's function calling overhead is |
1221 | matter. |
1218 | high, and updating all the data structures is costly). |
|
|
1219 | |
|
|
1220 | The pure perl event loop is much slower, but still competitive. |
|
|
1221 | |
1222 | |
1222 | POE also performs much better in this case, but is is still far behind the |
1223 | POE also performs much better in this case, but is is still far behind the |
1223 | others. |
1224 | others. |
1224 | |
1225 | |
1225 | =head3 Summary |
1226 | =head3 Summary |
… | |
… | |
1233 | |
1234 | |
1234 | |
1235 | |
1235 | =head1 FORK |
1236 | =head1 FORK |
1236 | |
1237 | |
1237 | Most event libraries are not fork-safe. The ones who are usually are |
1238 | Most event libraries are not fork-safe. The ones who are usually are |
1238 | because they are so inefficient. Only L<EV> is fully fork-aware. |
1239 | because they rely on inefficient but fork-safe C<select> or C<poll> |
|
|
1240 | calls. Only L<EV> is fully fork-aware. |
1239 | |
1241 | |
1240 | If you have to fork, you must either do so I<before> creating your first |
1242 | If you have to fork, you must either do so I<before> creating your first |
1241 | watcher OR you must not use AnyEvent at all in the child. |
1243 | watcher OR you must not use AnyEvent at all in the child. |
1242 | |
1244 | |
1243 | |
1245 | |