… | |
… | |
65 | technically possible. |
65 | technically possible. |
66 | |
66 | |
67 | Of course, if you want lots of policy (this can arguably be somewhat |
67 | Of course, if you want lots of policy (this can arguably be somewhat |
68 | useful) and you want to force your users to use the one and only event |
68 | useful) and you want to force your users to use the one and only event |
69 | model, you should I<not> use this module. |
69 | model, you should I<not> use this module. |
70 | |
|
|
71 | |
70 | |
72 | =head1 DESCRIPTION |
71 | =head1 DESCRIPTION |
73 | |
72 | |
74 | L<AnyEvent> provides an identical interface to multiple event loops. This |
73 | L<AnyEvent> provides an identical interface to multiple event loops. This |
75 | allows module authors to utilise an event loop without forcing module |
74 | allows module authors to utilise an event loop without forcing module |
… | |
… | |
391 | |
390 | |
392 | AnyEvent::Impl::CoroEV based on Coro::EV, best choice. |
391 | AnyEvent::Impl::CoroEV based on Coro::EV, best choice. |
393 | AnyEvent::Impl::CoroEvent based on Coro::Event, second best choice. |
392 | AnyEvent::Impl::CoroEvent based on Coro::Event, second best choice. |
394 | 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). |
395 | 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. |
396 | AnyEvent::Impl::Glib based on Glib, third-best choice. |
396 | AnyEvent::Impl::Glib based on Glib, third-best choice. |
397 | AnyEvent::Impl::Perl pure-perl implementation, inefficient but portable. |
|
|
398 | AnyEvent::Impl::Tk based on Tk, very bad choice. |
397 | AnyEvent::Impl::Tk based on Tk, very bad choice. |
399 | 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). |
400 | AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse. |
399 | AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse. |
401 | 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. |
402 | |
401 | |
… | |
… | |
458 | |
457 | |
459 | You can chose to use a rather inefficient pure-perl implementation by |
458 | You can chose to use a rather inefficient pure-perl implementation by |
460 | loading the C<AnyEvent::Impl::Perl> module, which gives you similar |
459 | loading the C<AnyEvent::Impl::Perl> module, which gives you similar |
461 | behaviour everywhere, but letting AnyEvent chose is generally better. |
460 | behaviour everywhere, but letting AnyEvent chose is generally better. |
462 | |
461 | |
|
|
462 | =head1 OTHER MODULES |
|
|
463 | |
|
|
464 | The following is a non-exhaustive list of additional modules that use |
|
|
465 | AnyEvent and can therefore be mixed easily with other AnyEvent modules |
|
|
466 | in the same program. Some of the modules come with AnyEvent, some are |
|
|
467 | available via CPAN. |
|
|
468 | |
|
|
469 | =over 4 |
|
|
470 | |
|
|
471 | =item L<AnyEvent::Util> |
|
|
472 | |
|
|
473 | Contains various utility functions that replace often-used but blocking |
|
|
474 | functions such as C<inet_aton> by event-/callback-based versions. |
|
|
475 | |
|
|
476 | =item L<AnyEvent::Handle> |
|
|
477 | |
|
|
478 | Provide read and write buffers and manages watchers for reads and writes. |
|
|
479 | |
|
|
480 | =item L<AnyEvent::Socket> |
|
|
481 | |
|
|
482 | Provides a means to do non-blocking connects, accepts etc. |
|
|
483 | |
|
|
484 | =item L<AnyEvent::HTTPD> |
|
|
485 | |
|
|
486 | Provides a simple web application server framework. |
|
|
487 | |
|
|
488 | =item L<AnyEvent::DNS> |
|
|
489 | |
|
|
490 | Provides asynchronous DNS resolver capabilities, beyond what |
|
|
491 | L<AnyEvent::Util> offers. |
|
|
492 | |
|
|
493 | =item L<AnyEvent::FastPing> |
|
|
494 | |
|
|
495 | The fastest ping in the west. |
|
|
496 | |
|
|
497 | =item L<Net::IRC3> |
|
|
498 | |
|
|
499 | AnyEvent based IRC client module family. |
|
|
500 | |
|
|
501 | =item L<Net::XMPP2> |
|
|
502 | |
|
|
503 | AnyEvent based XMPP (Jabber protocol) module family. |
|
|
504 | |
|
|
505 | =item L<Net::FCP> |
|
|
506 | |
|
|
507 | AnyEvent-based implementation of the Freenet Client Protocol, birthplace |
|
|
508 | of AnyEvent. |
|
|
509 | |
|
|
510 | =item L<Event::ExecFlow> |
|
|
511 | |
|
|
512 | High level API for event-based execution flow control. |
|
|
513 | |
|
|
514 | =item L<Coro> |
|
|
515 | |
|
|
516 | Has special support for AnyEvent. |
|
|
517 | |
|
|
518 | =item L<IO::Lambda> |
|
|
519 | |
|
|
520 | The lambda approach to I/O - don't ask, look there. Can use AnyEvent. |
|
|
521 | |
|
|
522 | =item L<IO::AIO> |
|
|
523 | |
|
|
524 | Truly asynchronous I/O, should be in the toolbox of every event |
|
|
525 | programmer. Can be trivially made to use AnyEvent. |
|
|
526 | |
|
|
527 | =item L<BDB> |
|
|
528 | |
|
|
529 | Truly asynchronous Berkeley DB access. Can be trivially made to use |
|
|
530 | AnyEvent. |
|
|
531 | |
|
|
532 | =back |
|
|
533 | |
463 | =cut |
534 | =cut |
464 | |
535 | |
465 | package AnyEvent; |
536 | package AnyEvent; |
466 | |
537 | |
467 | no warnings; |
538 | no warnings; |
… | |
… | |
482 | my @models = ( |
553 | my @models = ( |
483 | [Coro::EV:: => AnyEvent::Impl::CoroEV::], |
554 | [Coro::EV:: => AnyEvent::Impl::CoroEV::], |
484 | [Coro::Event:: => AnyEvent::Impl::CoroEvent::], |
555 | [Coro::Event:: => AnyEvent::Impl::CoroEvent::], |
485 | [EV:: => AnyEvent::Impl::EV::], |
556 | [EV:: => AnyEvent::Impl::EV::], |
486 | [Event:: => AnyEvent::Impl::Event::], |
557 | [Event:: => AnyEvent::Impl::Event::], |
487 | [Glib:: => AnyEvent::Impl::Glib::], |
|
|
488 | [Tk:: => AnyEvent::Impl::Tk::], |
558 | [Tk:: => AnyEvent::Impl::Tk::], |
489 | [Wx:: => AnyEvent::Impl::POE::], |
559 | [Wx:: => AnyEvent::Impl::POE::], |
490 | [Prima:: => AnyEvent::Impl::POE::], |
560 | [Prima:: => AnyEvent::Impl::POE::], |
491 | [AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::], |
561 | [AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::], |
492 | # 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::], |
493 | [Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy |
564 | [Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy |
494 | [Qt:: => AnyEvent::Impl::Qt::], # requires special main program |
565 | [Qt:: => AnyEvent::Impl::Qt::], # requires special main program |
495 | [POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza |
566 | [POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza |
496 | ); |
567 | ); |
497 | |
568 | |
… | |
… | |
944 | EV/EV 400000 244 0.56 0.46 0.31 EV native interface |
1015 | EV/EV 400000 244 0.56 0.46 0.31 EV native interface |
945 | EV/Any 100000 244 2.50 0.46 0.29 EV + AnyEvent watchers |
1016 | EV/Any 100000 244 2.50 0.46 0.29 EV + AnyEvent watchers |
946 | CoroEV/Any 100000 244 2.49 0.44 0.29 coroutines + Coro::Signal |
1017 | CoroEV/Any 100000 244 2.49 0.44 0.29 coroutines + Coro::Signal |
947 | Perl/Any 100000 513 4.92 0.87 1.12 pure perl implementation |
1018 | Perl/Any 100000 513 4.92 0.87 1.12 pure perl implementation |
948 | Event/Event 16000 516 31.88 31.30 0.85 Event native interface |
1019 | Event/Event 16000 516 31.88 31.30 0.85 Event native interface |
949 | Event/Any 16000 936 39.17 33.63 1.43 Event + AnyEvent watchers |
1020 | Event/Any 16000 590 35.75 31.42 1.08 Event + AnyEvent watchers |
950 | Glib/Any 16000 1357 98.22 12.41 54.00 quadratic behaviour |
1021 | Glib/Any 16000 1357 98.22 12.41 54.00 quadratic behaviour |
951 | Tk/Any 2000 1860 26.97 67.98 14.00 SEGV with >> 2000 watchers |
1022 | Tk/Any 2000 1860 26.97 67.98 14.00 SEGV with >> 2000 watchers |
952 | POE/Event 2000 6644 108.64 736.02 14.73 via POE::Loop::Event |
1023 | POE/Event 2000 6644 108.64 736.02 14.73 via POE::Loop::Event |
953 | POE/Select 2000 6343 94.13 809.12 565.96 via POE::Loop::Select |
1024 | POE/Select 2000 6343 94.13 809.12 565.96 via POE::Loop::Select |
954 | |
1025 | |
… | |
… | |
958 | well. For example, a select-based event loop (such as the pure perl one) |
1029 | well. For example, a select-based event loop (such as the pure perl one) |
959 | can never compete with an event loop that uses epoll when the number of |
1030 | can never compete with an event loop that uses epoll when the number of |
960 | file descriptors grows high. In this benchmark, all events become ready at |
1031 | file descriptors grows high. In this benchmark, all events become ready at |
961 | the same time, so select/poll-based implementations get an unnatural speed |
1032 | the same time, so select/poll-based implementations get an unnatural speed |
962 | boost. |
1033 | boost. |
|
|
1034 | |
|
|
1035 | Also, note that the number of watchers usually has a nonlinear effect on |
|
|
1036 | overall speed, that is, creating twice as many watchers doesn't take twice |
|
|
1037 | the time - usually it takes longer. This puts event loops tested with a |
|
|
1038 | higher number of watchers at a disadvantage. |
|
|
1039 | |
|
|
1040 | To put the range of results into perspective, consider that on the |
|
|
1041 | benchmark machine, handling an event takes roughly 1600 CPU cycles with |
|
|
1042 | EV, 3100 CPU cycles with AnyEvent's pure perl loop and almost 3000000 CPU |
|
|
1043 | cycles with POE. |
963 | |
1044 | |
964 | C<EV> is the sole leader regarding speed and memory use, which are both |
1045 | C<EV> is the sole leader regarding speed and memory use, which are both |
965 | maximal/minimal, respectively. Even when going through AnyEvent, it uses |
1046 | maximal/minimal, respectively. Even when going through AnyEvent, it uses |
966 | far less memory than any other event loop and is still faster than Event |
1047 | far less memory than any other event loop and is still faster than Event |
967 | natively. |
1048 | natively. |
… | |
… | |
990 | 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() |
991 | 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 |
992 | 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 |
993 | above). |
1074 | above). |
994 | |
1075 | |
995 | C<POE>, regardless of underlying event loop (whether using its pure |
1076 | C<POE>, regardless of underlying event loop (whether using its pure perl |
996 | 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 |
997 | couldn't be tested because it wasn't working) shows abysmal performance |
1078 | be tested because it wasn't working) shows abysmal performance and |
998 | 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 |
999 | 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 |
1000 | requirements are caused by requiring a session for each watcher). Watcher |
1081 | requirements are caused by requiring a session for each watcher). Watcher |
1001 | 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 | |
1002 | 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 |
1003 | really account for this, as session creation overhead is small compared |
1086 | for the performance issues, though, as session creation overhead is |
1004 | 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 |
1005 | 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). |
1006 | |
1092 | |
1007 | =head3 Summary |
1093 | =head3 Summary |
1008 | |
1094 | |
1009 | =over 4 |
1095 | =over 4 |
1010 | |
1096 | |
… | |
… | |
1043 | distribution. |
1129 | distribution. |
1044 | |
1130 | |
1045 | =head3 Explanation of the columns |
1131 | =head3 Explanation of the columns |
1046 | |
1132 | |
1047 | I<sockets> is the number of sockets, and twice the number of "servers" (as |
1133 | I<sockets> is the number of sockets, and twice the number of "servers" (as |
1048 | eahc server has a read and write socket end). |
1134 | each server has a read and write socket end). |
1049 | |
1135 | |
1050 | I<create> is the time it takes to create a socketpair (which is |
1136 | I<create> is the time it takes to create a socketpair (which is |
1051 | nontrivial) and two watchers: an I/O watcher and a timeout watcher. |
1137 | nontrivial) and two watchers: an I/O watcher and a timeout watcher. |
1052 | |
1138 | |
1053 | I<request>, the most important value, is the time it takes to handle a |
1139 | I<request>, the most important value, is the time it takes to handle a |
… | |
… | |
1057 | |
1143 | |
1058 | =head3 Results |
1144 | =head3 Results |
1059 | |
1145 | |
1060 | name sockets create request |
1146 | name sockets create request |
1061 | EV 20000 69.01 11.16 |
1147 | EV 20000 69.01 11.16 |
1062 | Perl 20000 75.28 112.76 |
1148 | Perl 20000 73.32 35.87 |
1063 | Event 20000 212.62 257.32 |
1149 | Event 20000 212.62 257.32 |
1064 | Glib 20000 651.16 1896.30 |
1150 | Glib 20000 651.16 1896.30 |
1065 | POE 20000 349.67 12317.24 uses POE::Loop::Event |
1151 | POE 20000 349.67 12317.24 uses POE::Loop::Event |
1066 | |
1152 | |
1067 | =head3 Discussion |
1153 | =head3 Discussion |
… | |
… | |
1089 | |
1175 | |
1090 | =head3 Summary |
1176 | =head3 Summary |
1091 | |
1177 | |
1092 | =over 4 |
1178 | =over 4 |
1093 | |
1179 | |
1094 | =item * The pure perl implementation performs extremely well, considering |
1180 | =item * The pure perl implementation performs extremely well. |
1095 | that it uses select. |
|
|
1096 | |
1181 | |
1097 | =item * Avoid Glib or POE in large projects where performance matters. |
1182 | =item * Avoid Glib or POE in large projects where performance matters. |
1098 | |
1183 | |
1099 | =back |
1184 | =back |
1100 | |
1185 | |
… | |
… | |
1113 | |
1198 | |
1114 | =head3 Results |
1199 | =head3 Results |
1115 | |
1200 | |
1116 | name sockets create request |
1201 | name sockets create request |
1117 | EV 16 20.00 6.54 |
1202 | EV 16 20.00 6.54 |
|
|
1203 | Perl 16 25.75 12.62 |
1118 | Event 16 81.27 35.86 |
1204 | Event 16 81.27 35.86 |
1119 | Glib 16 32.63 15.48 |
1205 | Glib 16 32.63 15.48 |
1120 | Perl 16 24.62 162.37 |
|
|
1121 | POE 16 261.87 276.28 uses POE::Loop::Event |
1206 | POE 16 261.87 276.28 uses POE::Loop::Event |
1122 | |
1207 | |
1123 | =head3 Discussion |
1208 | =head3 Discussion |
1124 | |
1209 | |
1125 | The benchmark tries to test the performance of a typical small |
1210 | The benchmark tries to test the performance of a typical small |
1126 | server. While knowing how various event loops perform is interesting, keep |
1211 | server. While knowing how various event loops perform is interesting, keep |
1127 | in mind that their overhead in this case is usually not as important, due |
1212 | in mind that their overhead in this case is usually not as important, due |
1128 | to the small absolute number of watchers. |
1213 | to the small absolute number of watchers (that is, you need efficiency and |
|
|
1214 | speed most when you have lots of watchers, not when you only have a few of |
|
|
1215 | them). |
1129 | |
1216 | |
1130 | EV is again fastest. |
1217 | EV is again fastest. |
1131 | |
1218 | |
1132 | 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 |
1133 | 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 |
1134 | code to execute in the inner loop, and perl's function calling overhead is |
1221 | matter. |
1135 | high, and updating all the data structures is costly). |
|
|
1136 | |
1222 | |
1137 | The pure perl event loop is much slower, but still competitive. |
|
|
1138 | |
|
|
1139 | POE also performs much better in this case, but is is stillf ar behind the |
1223 | POE also performs much better in this case, but is is still far behind the |
1140 | others. |
1224 | others. |
1141 | |
1225 | |
1142 | =head3 Summary |
1226 | =head3 Summary |
1143 | |
1227 | |
1144 | =over 4 |
1228 | =over 4 |
… | |
… | |
1150 | |
1234 | |
1151 | |
1235 | |
1152 | =head1 FORK |
1236 | =head1 FORK |
1153 | |
1237 | |
1154 | 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 |
1155 | 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. |
1156 | |
1241 | |
1157 | 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 |
1158 | 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. |
1159 | |
1244 | |
1160 | |
1245 | |