1 | =head1 NAME |
1 | =head1 => NAME |
2 | |
2 | |
3 | AnyEvent - provide framework for multiple event loops |
3 | AnyEvent - provide framework for multiple event loops |
4 | |
4 | |
5 | EV, Event, Glib, Tk, Perl, Event::Lib, Qt, POE - various supported event loops |
5 | EV, Event, Glib, Tk, Perl, Event::Lib, Qt, POE - various supported event loops |
6 | |
6 | |
… | |
… | |
57 | as those use one of the supported event loops. It is trivial to add new |
57 | as those use one of the supported event loops. It is trivial to add new |
58 | event loops to AnyEvent, too, so it is future-proof). |
58 | event loops to AnyEvent, too, so it is future-proof). |
59 | |
59 | |
60 | In addition to being free of having to use I<the one and only true event |
60 | In addition to being free of having to use I<the one and only true event |
61 | model>, AnyEvent also is free of bloat and policy: with POE or similar |
61 | model>, AnyEvent also is free of bloat and policy: with POE or similar |
62 | modules, you get an enourmous amount of code and strict rules you have to |
62 | modules, you get an enormous amount of code and strict rules you have to |
63 | follow. AnyEvent, on the other hand, is lean and up to the point, by only |
63 | follow. AnyEvent, on the other hand, is lean and up to the point, by only |
64 | offering the functionality that is necessary, in as thin as a wrapper as |
64 | offering the functionality that is necessary, in as thin as a wrapper as |
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 |
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108 | |
108 | |
109 | =head1 WATCHERS |
109 | =head1 WATCHERS |
110 | |
110 | |
111 | AnyEvent has the central concept of a I<watcher>, which is an object that |
111 | AnyEvent has the central concept of a I<watcher>, which is an object that |
112 | stores relevant data for each kind of event you are waiting for, such as |
112 | stores relevant data for each kind of event you are waiting for, such as |
113 | the callback to call, the filehandle to watch, etc. |
113 | the callback to call, the file handle to watch, etc. |
114 | |
114 | |
115 | These watchers are normal Perl objects with normal Perl lifetime. After |
115 | These watchers are normal Perl objects with normal Perl lifetime. After |
116 | creating a watcher it will immediately "watch" for events and invoke the |
116 | creating a watcher it will immediately "watch" for events and invoke the |
117 | callback when the event occurs (of course, only when the event model |
117 | callback when the event occurs (of course, only when the event model |
118 | is in control). |
118 | is in control). |
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237 | |
237 | |
238 | Although the callback might get passed parameters, their value and |
238 | Although the callback might get passed parameters, their value and |
239 | presence is undefined and you cannot rely on them. Portable AnyEvent |
239 | presence is undefined and you cannot rely on them. Portable AnyEvent |
240 | callbacks cannot use arguments passed to signal watcher callbacks. |
240 | callbacks cannot use arguments passed to signal watcher callbacks. |
241 | |
241 | |
242 | Multiple signal occurances can be clumped together into one callback |
242 | Multiple signal occurrences can be clumped together into one callback |
243 | invocation, and callback invocation will be synchronous. synchronous means |
243 | invocation, and callback invocation will be synchronous. Synchronous means |
244 | that it might take a while until the signal gets handled by the process, |
244 | that it might take a while until the signal gets handled by the process, |
245 | but it is guarenteed not to interrupt any other callbacks. |
245 | but it is guaranteed not to interrupt any other callbacks. |
246 | |
246 | |
247 | The main advantage of using these watchers is that you can share a signal |
247 | The main advantage of using these watchers is that you can share a signal |
248 | between multiple watchers. |
248 | between multiple watchers. |
249 | |
249 | |
250 | This watcher might use C<%SIG>, so programs overwriting those signals |
250 | This watcher might use C<%SIG>, so programs overwriting those signals |
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310 | Condition variables can be created by calling the C<< AnyEvent->condvar |
310 | Condition variables can be created by calling the C<< AnyEvent->condvar |
311 | >> method, usually without arguments. The only argument pair allowed is |
311 | >> method, usually without arguments. The only argument pair allowed is |
312 | C<cb>, which specifies a callback to be called when the condition variable |
312 | C<cb>, which specifies a callback to be called when the condition variable |
313 | becomes true. |
313 | becomes true. |
314 | |
314 | |
315 | After creation, the conditon variable is "false" until it becomes "true" |
315 | After creation, the condition variable is "false" until it becomes "true" |
316 | by calling the C<send> method. |
316 | by calling the C<send> method (or calling the condition variable as if it |
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317 | were a callback). |
317 | |
318 | |
318 | Condition variables are similar to callbacks, except that you can |
319 | Condition variables are similar to callbacks, except that you can |
319 | optionally wait for them. They can also be called merge points - points |
320 | optionally wait for them. They can also be called merge points - points |
320 | in time where multiple outstandign events have been processed. And yet |
321 | in time where multiple outstanding events have been processed. And yet |
321 | another way to call them is transations - each condition variable can be |
322 | another way to call them is transactions - each condition variable can be |
322 | used to represent a transaction, which finishes at some point and delivers |
323 | used to represent a transaction, which finishes at some point and delivers |
323 | a result. |
324 | a result. |
324 | |
325 | |
325 | Condition variables are very useful to signal that something has finished, |
326 | Condition variables are very useful to signal that something has finished, |
326 | for example, if you write a module that does asynchronous http requests, |
327 | for example, if you write a module that does asynchronous http requests, |
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332 | you can block your main program until an event occurs - for example, you |
333 | you can block your main program until an event occurs - for example, you |
333 | could C<< ->recv >> in your main program until the user clicks the Quit |
334 | could C<< ->recv >> in your main program until the user clicks the Quit |
334 | button of your app, which would C<< ->send >> the "quit" event. |
335 | button of your app, which would C<< ->send >> the "quit" event. |
335 | |
336 | |
336 | Note that condition variables recurse into the event loop - if you have |
337 | Note that condition variables recurse into the event loop - if you have |
337 | two pieces of code that call C<< ->recv >> in a round-robbin fashion, you |
338 | two pieces of code that call C<< ->recv >> in a round-robin fashion, you |
338 | lose. Therefore, condition variables are good to export to your caller, but |
339 | lose. Therefore, condition variables are good to export to your caller, but |
339 | you should avoid making a blocking wait yourself, at least in callbacks, |
340 | you should avoid making a blocking wait yourself, at least in callbacks, |
340 | as this asks for trouble. |
341 | as this asks for trouble. |
341 | |
342 | |
342 | Condition variables are represented by hash refs in perl, and the keys |
343 | Condition variables are represented by hash refs in perl, and the keys |
… | |
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347 | |
348 | |
348 | There are two "sides" to a condition variable - the "producer side" which |
349 | There are two "sides" to a condition variable - the "producer side" which |
349 | eventually calls C<< -> send >>, and the "consumer side", which waits |
350 | eventually calls C<< -> send >>, and the "consumer side", which waits |
350 | for the send to occur. |
351 | for the send to occur. |
351 | |
352 | |
352 | Example: |
353 | Example: wait for a timer. |
353 | |
354 | |
354 | # wait till the result is ready |
355 | # wait till the result is ready |
355 | my $result_ready = AnyEvent->condvar; |
356 | my $result_ready = AnyEvent->condvar; |
356 | |
357 | |
357 | # do something such as adding a timer |
358 | # do something such as adding a timer |
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365 | |
366 | |
366 | # this "blocks" (while handling events) till the callback |
367 | # this "blocks" (while handling events) till the callback |
367 | # calls send |
368 | # calls send |
368 | $result_ready->recv; |
369 | $result_ready->recv; |
369 | |
370 | |
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371 | Example: wait for a timer, but take advantage of the fact that |
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372 | condition variables are also code references. |
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373 | |
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374 | my $done = AnyEvent->condvar; |
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375 | my $delay = AnyEvent->timer (after => 5, cb => $done); |
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376 | $done->recv; |
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377 | |
370 | =head3 METHODS FOR PRODUCERS |
378 | =head3 METHODS FOR PRODUCERS |
371 | |
379 | |
372 | These methods should only be used by the producing side, i.e. the |
380 | These methods should only be used by the producing side, i.e. the |
373 | code/module that eventually sends the signal. Note that it is also |
381 | code/module that eventually sends the signal. Note that it is also |
374 | the producer side which creates the condvar in most cases, but it isn't |
382 | the producer side which creates the condvar in most cases, but it isn't |
… | |
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385 | If a callback has been set on the condition variable, it is called |
393 | If a callback has been set on the condition variable, it is called |
386 | immediately from within send. |
394 | immediately from within send. |
387 | |
395 | |
388 | Any arguments passed to the C<send> call will be returned by all |
396 | Any arguments passed to the C<send> call will be returned by all |
389 | future C<< ->recv >> calls. |
397 | future C<< ->recv >> calls. |
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398 | |
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399 | Condition variables are overloaded so one can call them directly (as a |
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400 | code reference). Calling them directly is the same as calling C<send>. |
390 | |
401 | |
391 | =item $cv->croak ($error) |
402 | =item $cv->croak ($error) |
392 | |
403 | |
393 | Similar to send, but causes all call's to C<< ->recv >> to invoke |
404 | Similar to send, but causes all call's to C<< ->recv >> to invoke |
394 | C<Carp::croak> with the given error message/object/scalar. |
405 | C<Carp::croak> with the given error message/object/scalar. |
… | |
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443 | doesn't execute once). |
454 | doesn't execute once). |
444 | |
455 | |
445 | This is the general pattern when you "fan out" into multiple subrequests: |
456 | This is the general pattern when you "fan out" into multiple subrequests: |
446 | use an outer C<begin>/C<end> pair to set the callback and ensure C<end> |
457 | use an outer C<begin>/C<end> pair to set the callback and ensure C<end> |
447 | is called at least once, and then, for each subrequest you start, call |
458 | is called at least once, and then, for each subrequest you start, call |
448 | C<begin> and for eahc subrequest you finish, call C<end>. |
459 | C<begin> and for each subrequest you finish, call C<end>. |
449 | |
460 | |
450 | =back |
461 | =back |
451 | |
462 | |
452 | =head3 METHODS FOR CONSUMERS |
463 | =head3 METHODS FOR CONSUMERS |
453 | |
464 | |
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475 | (programs might want to do that to stay interactive), so I<if you are |
486 | (programs might want to do that to stay interactive), so I<if you are |
476 | using this from a module, never require a blocking wait>, but let the |
487 | using this from a module, never require a blocking wait>, but let the |
477 | caller decide whether the call will block or not (for example, by coupling |
488 | caller decide whether the call will block or not (for example, by coupling |
478 | condition variables with some kind of request results and supporting |
489 | condition variables with some kind of request results and supporting |
479 | callbacks so the caller knows that getting the result will not block, |
490 | callbacks so the caller knows that getting the result will not block, |
480 | while still suppporting blocking waits if the caller so desires). |
491 | while still supporting blocking waits if the caller so desires). |
481 | |
492 | |
482 | Another reason I<never> to C<< ->recv >> in a module is that you cannot |
493 | Another reason I<never> to C<< ->recv >> in a module is that you cannot |
483 | sensibly have two C<< ->recv >>'s in parallel, as that would require |
494 | sensibly have two C<< ->recv >>'s in parallel, as that would require |
484 | multiple interpreters or coroutines/threads, none of which C<AnyEvent> |
495 | multiple interpreters or coroutines/threads, none of which C<AnyEvent> |
485 | can supply. |
496 | can supply. |
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601 | |
612 | |
602 | If it doesn't care, it can just "use AnyEvent" and use it itself, or not |
613 | If it doesn't care, it can just "use AnyEvent" and use it itself, or not |
603 | do anything special (it does not need to be event-based) and let AnyEvent |
614 | do anything special (it does not need to be event-based) and let AnyEvent |
604 | decide which implementation to chose if some module relies on it. |
615 | decide which implementation to chose if some module relies on it. |
605 | |
616 | |
606 | If the main program relies on a specific event model. For example, in |
617 | If the main program relies on a specific event model - for example, in |
607 | Gtk2 programs you have to rely on the Glib module. You should load the |
618 | Gtk2 programs you have to rely on the Glib module - you should load the |
608 | event module before loading AnyEvent or any module that uses it: generally |
619 | event module before loading AnyEvent or any module that uses it: generally |
609 | speaking, you should load it as early as possible. The reason is that |
620 | speaking, you should load it as early as possible. The reason is that |
610 | modules might create watchers when they are loaded, and AnyEvent will |
621 | modules might create watchers when they are loaded, and AnyEvent will |
611 | decide on the event model to use as soon as it creates watchers, and it |
622 | decide on the event model to use as soon as it creates watchers, and it |
612 | might chose the wrong one unless you load the correct one yourself. |
623 | might chose the wrong one unless you load the correct one yourself. |
613 | |
624 | |
614 | You can chose to use a rather inefficient pure-perl implementation by |
625 | You can chose to use a pure-perl implementation by loading the |
615 | loading the C<AnyEvent::Impl::Perl> module, which gives you similar |
626 | C<AnyEvent::Impl::Perl> module, which gives you similar behaviour |
616 | behaviour everywhere, but letting AnyEvent chose is generally better. |
627 | everywhere, but letting AnyEvent chose the model is generally better. |
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628 | |
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629 | =head2 MAINLOOP EMULATION |
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630 | |
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631 | Sometimes (often for short test scripts, or even standalone programs who |
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632 | only want to use AnyEvent), you do not want to run a specific event loop. |
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633 | |
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634 | In that case, you can use a condition variable like this: |
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635 | |
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636 | AnyEvent->condvar->recv; |
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637 | |
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638 | This has the effect of entering the event loop and looping forever. |
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639 | |
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640 | Note that usually your program has some exit condition, in which case |
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641 | it is better to use the "traditional" approach of storing a condition |
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642 | variable somewhere, waiting for it, and sending it when the program should |
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643 | exit cleanly. |
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644 | |
617 | |
645 | |
618 | =head1 OTHER MODULES |
646 | =head1 OTHER MODULES |
619 | |
647 | |
620 | The following is a non-exhaustive list of additional modules that use |
648 | The following is a non-exhaustive list of additional modules that use |
621 | AnyEvent and can therefore be mixed easily with other AnyEvent modules |
649 | AnyEvent and can therefore be mixed easily with other AnyEvent modules |
… | |
… | |
631 | |
659 | |
632 | =item L<AnyEvent::Handle> |
660 | =item L<AnyEvent::Handle> |
633 | |
661 | |
634 | Provide read and write buffers and manages watchers for reads and writes. |
662 | Provide read and write buffers and manages watchers for reads and writes. |
635 | |
663 | |
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664 | =item L<AnyEvent::Socket> |
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665 | |
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666 | Provides various utility functions for (internet protocol) sockets, |
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667 | addresses and name resolution. Also functions to create non-blocking tcp |
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668 | connections or tcp servers, with IPv6 and SRV record support and more. |
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669 | |
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670 | =item L<AnyEvent::DNS> |
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671 | |
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672 | Provides rich asynchronous DNS resolver capabilities. |
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673 | |
636 | =item L<AnyEvent::HTTPD> |
674 | =item L<AnyEvent::HTTPD> |
637 | |
675 | |
638 | Provides a simple web application server framework. |
676 | Provides a simple web application server framework. |
639 | |
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640 | =item L<AnyEvent::DNS> |
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641 | |
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642 | Provides asynchronous DNS resolver capabilities, beyond what |
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643 | L<AnyEvent::Util> offers. |
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644 | |
677 | |
645 | =item L<AnyEvent::FastPing> |
678 | =item L<AnyEvent::FastPing> |
646 | |
679 | |
647 | The fastest ping in the west. |
680 | The fastest ping in the west. |
648 | |
681 | |
… | |
… | |
691 | no warnings; |
724 | no warnings; |
692 | use strict; |
725 | use strict; |
693 | |
726 | |
694 | use Carp; |
727 | use Carp; |
695 | |
728 | |
696 | our $VERSION = '3.5'; |
729 | our $VERSION = '4.03'; |
697 | our $MODEL; |
730 | our $MODEL; |
698 | |
731 | |
699 | our $AUTOLOAD; |
732 | our $AUTOLOAD; |
700 | our @ISA; |
733 | our @ISA; |
701 | |
734 | |
702 | our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1; |
735 | our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1; |
703 | |
736 | |
704 | our @REGISTRY; |
737 | our @REGISTRY; |
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738 | |
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739 | our %PROTOCOL; # (ipv4|ipv6) => (1|2) |
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740 | |
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741 | { |
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742 | my $idx; |
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743 | $PROTOCOL{$_} = ++$idx |
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744 | for split /\s*,\s*/, $ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6"; |
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745 | } |
705 | |
746 | |
706 | my @models = ( |
747 | my @models = ( |
707 | [EV:: => AnyEvent::Impl::EV::], |
748 | [EV:: => AnyEvent::Impl::EV::], |
708 | [Event:: => AnyEvent::Impl::Event::], |
749 | [Event:: => AnyEvent::Impl::Event::], |
709 | [Tk:: => AnyEvent::Impl::Tk::], |
750 | [Tk:: => AnyEvent::Impl::Tk::], |
… | |
… | |
811 | package AnyEvent::Base; |
852 | package AnyEvent::Base; |
812 | |
853 | |
813 | # default implementation for ->condvar |
854 | # default implementation for ->condvar |
814 | |
855 | |
815 | sub condvar { |
856 | sub condvar { |
816 | bless {}, AnyEvent::CondVar:: |
857 | bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, AnyEvent::CondVar:: |
817 | } |
858 | } |
818 | |
859 | |
819 | # default implementation for ->signal |
860 | # default implementation for ->signal |
820 | |
861 | |
821 | our %SIG_CB; |
862 | our %SIG_CB; |
… | |
… | |
901 | |
942 | |
902 | our @ISA = AnyEvent::CondVar::Base::; |
943 | our @ISA = AnyEvent::CondVar::Base::; |
903 | |
944 | |
904 | package AnyEvent::CondVar::Base; |
945 | package AnyEvent::CondVar::Base; |
905 | |
946 | |
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947 | use overload |
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948 | '&{}' => sub { my $self = shift; sub { $self->send (@_) } }, |
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949 | fallback => 1; |
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950 | |
906 | sub _send { |
951 | sub _send { |
907 | # nop |
952 | # nop |
908 | } |
953 | } |
909 | |
954 | |
910 | sub send { |
955 | sub send { |
… | |
… | |
944 | $_[0]{_ae_end_cb} = $_[1] if @_ > 1; |
989 | $_[0]{_ae_end_cb} = $_[1] if @_ > 1; |
945 | } |
990 | } |
946 | |
991 | |
947 | sub end { |
992 | sub end { |
948 | return if --$_[0]{_ae_counter}; |
993 | return if --$_[0]{_ae_counter}; |
949 | &{ $_[0]{_ae_end_cb} } if $_[0]{_ae_end_cb}; |
994 | &{ $_[0]{_ae_end_cb} || sub { $_[0]->send } }; |
950 | } |
995 | } |
951 | |
996 | |
952 | # undocumented/compatibility with pre-3.4 |
997 | # undocumented/compatibility with pre-3.4 |
953 | *broadcast = \&send; |
998 | *broadcast = \&send; |
954 | *wait = \&_wait; |
999 | *wait = \&_wait; |
… | |
… | |
1016 | model it chooses. |
1061 | model it chooses. |
1017 | |
1062 | |
1018 | =item C<PERL_ANYEVENT_MODEL> |
1063 | =item C<PERL_ANYEVENT_MODEL> |
1019 | |
1064 | |
1020 | This can be used to specify the event model to be used by AnyEvent, before |
1065 | This can be used to specify the event model to be used by AnyEvent, before |
1021 | autodetection and -probing kicks in. It must be a string consisting |
1066 | auto detection and -probing kicks in. It must be a string consisting |
1022 | entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended |
1067 | entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended |
1023 | and the resulting module name is loaded and if the load was successful, |
1068 | and the resulting module name is loaded and if the load was successful, |
1024 | used as event model. If it fails to load AnyEvent will proceed with |
1069 | used as event model. If it fails to load AnyEvent will proceed with |
1025 | autodetection and -probing. |
1070 | auto detection and -probing. |
1026 | |
1071 | |
1027 | This functionality might change in future versions. |
1072 | This functionality might change in future versions. |
1028 | |
1073 | |
1029 | For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you |
1074 | For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you |
1030 | could start your program like this: |
1075 | could start your program like this: |
1031 | |
1076 | |
1032 | PERL_ANYEVENT_MODEL=Perl perl ... |
1077 | PERL_ANYEVENT_MODEL=Perl perl ... |
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1078 | |
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1079 | =item C<PERL_ANYEVENT_PROTOCOLS> |
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1080 | |
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1081 | Used by both L<AnyEvent::DNS> and L<AnyEvent::Socket> to determine preferences |
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1082 | for IPv4 or IPv6. The default is unspecified (and might change, or be the result |
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1083 | of auto probing). |
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1084 | |
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1085 | Must be set to a comma-separated list of protocols or address families, |
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1086 | current supported: C<ipv4> and C<ipv6>. Only protocols mentioned will be |
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1087 | used, and preference will be given to protocols mentioned earlier in the |
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1088 | list. |
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1089 | |
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1090 | This variable can effectively be used for denial-of-service attacks |
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1091 | against local programs (e.g. when setuid), although the impact is likely |
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1092 | small, as the program has to handle connection errors already- |
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1093 | |
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1094 | Examples: C<PERL_ANYEVENT_PROTOCOLS=ipv4,ipv6> - prefer IPv4 over IPv6, |
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1095 | but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4> |
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1096 | - only support IPv4, never try to resolve or contact IPv6 |
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1097 | addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or |
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1098 | IPv6, but prefer IPv6 over IPv4. |
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1099 | |
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1100 | =item C<PERL_ANYEVENT_EDNS0> |
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1101 | |
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1102 | Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension |
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1103 | for DNS. This extension is generally useful to reduce DNS traffic, but |
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1104 | some (broken) firewalls drop such DNS packets, which is why it is off by |
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1105 | default. |
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1106 | |
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1107 | Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce |
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1108 | EDNS0 in its DNS requests. |
1033 | |
1109 | |
1034 | =back |
1110 | =back |
1035 | |
1111 | |
1036 | =head1 EXAMPLE PROGRAM |
1112 | =head1 EXAMPLE PROGRAM |
1037 | |
1113 | |
… | |
… | |
1123 | syswrite $txn->{fh}, $txn->{request} |
1199 | syswrite $txn->{fh}, $txn->{request} |
1124 | or die "connection or write error"; |
1200 | or die "connection or write error"; |
1125 | $txn->{w} = AnyEvent->io (fh => $txn->{fh}, poll => 'r', cb => sub { $txn->fh_ready_r }); |
1201 | $txn->{w} = AnyEvent->io (fh => $txn->{fh}, poll => 'r', cb => sub { $txn->fh_ready_r }); |
1126 | |
1202 | |
1127 | Again, C<fh_ready_r> waits till all data has arrived, and then stores the |
1203 | Again, C<fh_ready_r> waits till all data has arrived, and then stores the |
1128 | result and signals any possible waiters that the request ahs finished: |
1204 | result and signals any possible waiters that the request has finished: |
1129 | |
1205 | |
1130 | sysread $txn->{fh}, $txn->{buf}, length $txn->{$buf}; |
1206 | sysread $txn->{fh}, $txn->{buf}, length $txn->{$buf}; |
1131 | |
1207 | |
1132 | if (end-of-file or data complete) { |
1208 | if (end-of-file or data complete) { |
1133 | $txn->{result} = $txn->{buf}; |
1209 | $txn->{result} = $txn->{buf}; |
… | |
… | |
1141 | |
1217 | |
1142 | $txn->{finished}->recv; |
1218 | $txn->{finished}->recv; |
1143 | return $txn->{result}; |
1219 | return $txn->{result}; |
1144 | |
1220 | |
1145 | The actual code goes further and collects all errors (C<die>s, exceptions) |
1221 | The actual code goes further and collects all errors (C<die>s, exceptions) |
1146 | that occured during request processing. The C<result> method detects |
1222 | that occurred during request processing. The C<result> method detects |
1147 | whether an exception as thrown (it is stored inside the $txn object) |
1223 | whether an exception as thrown (it is stored inside the $txn object) |
1148 | and just throws the exception, which means connection errors and other |
1224 | and just throws the exception, which means connection errors and other |
1149 | problems get reported tot he code that tries to use the result, not in a |
1225 | problems get reported tot he code that tries to use the result, not in a |
1150 | random callback. |
1226 | random callback. |
1151 | |
1227 | |
… | |
… | |
1197 | of various event loops I prepared some benchmarks. |
1273 | of various event loops I prepared some benchmarks. |
1198 | |
1274 | |
1199 | =head2 BENCHMARKING ANYEVENT OVERHEAD |
1275 | =head2 BENCHMARKING ANYEVENT OVERHEAD |
1200 | |
1276 | |
1201 | Here is a benchmark of various supported event models used natively and |
1277 | Here is a benchmark of various supported event models used natively and |
1202 | through anyevent. The benchmark creates a lot of timers (with a zero |
1278 | through AnyEvent. The benchmark creates a lot of timers (with a zero |
1203 | timeout) and I/O watchers (watching STDOUT, a pty, to become writable, |
1279 | timeout) and I/O watchers (watching STDOUT, a pty, to become writable, |
1204 | which it is), lets them fire exactly once and destroys them again. |
1280 | which it is), lets them fire exactly once and destroys them again. |
1205 | |
1281 | |
1206 | Source code for this benchmark is found as F<eg/bench> in the AnyEvent |
1282 | Source code for this benchmark is found as F<eg/bench> in the AnyEvent |
1207 | distribution. |
1283 | distribution. |
… | |
… | |
1330 | |
1406 | |
1331 | =back |
1407 | =back |
1332 | |
1408 | |
1333 | =head2 BENCHMARKING THE LARGE SERVER CASE |
1409 | =head2 BENCHMARKING THE LARGE SERVER CASE |
1334 | |
1410 | |
1335 | This benchmark atcually benchmarks the event loop itself. It works by |
1411 | This benchmark actually benchmarks the event loop itself. It works by |
1336 | creating a number of "servers": each server consists of a socketpair, a |
1412 | creating a number of "servers": each server consists of a socket pair, a |
1337 | timeout watcher that gets reset on activity (but never fires), and an I/O |
1413 | timeout watcher that gets reset on activity (but never fires), and an I/O |
1338 | watcher waiting for input on one side of the socket. Each time the socket |
1414 | watcher waiting for input on one side of the socket. Each time the socket |
1339 | watcher reads a byte it will write that byte to a random other "server". |
1415 | watcher reads a byte it will write that byte to a random other "server". |
1340 | |
1416 | |
1341 | The effect is that there will be a lot of I/O watchers, only part of which |
1417 | The effect is that there will be a lot of I/O watchers, only part of which |
1342 | are active at any one point (so there is a constant number of active |
1418 | are active at any one point (so there is a constant number of active |
1343 | fds for each loop iterstaion, but which fds these are is random). The |
1419 | fds for each loop iteration, but which fds these are is random). The |
1344 | timeout is reset each time something is read because that reflects how |
1420 | timeout is reset each time something is read because that reflects how |
1345 | most timeouts work (and puts extra pressure on the event loops). |
1421 | most timeouts work (and puts extra pressure on the event loops). |
1346 | |
1422 | |
1347 | In this benchmark, we use 10000 socketpairs (20000 sockets), of which 100 |
1423 | In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100 |
1348 | (1%) are active. This mirrors the activity of large servers with many |
1424 | (1%) are active. This mirrors the activity of large servers with many |
1349 | connections, most of which are idle at any one point in time. |
1425 | connections, most of which are idle at any one point in time. |
1350 | |
1426 | |
1351 | Source code for this benchmark is found as F<eg/bench2> in the AnyEvent |
1427 | Source code for this benchmark is found as F<eg/bench2> in the AnyEvent |
1352 | distribution. |
1428 | distribution. |
… | |
… | |
1354 | =head3 Explanation of the columns |
1430 | =head3 Explanation of the columns |
1355 | |
1431 | |
1356 | I<sockets> is the number of sockets, and twice the number of "servers" (as |
1432 | I<sockets> is the number of sockets, and twice the number of "servers" (as |
1357 | each server has a read and write socket end). |
1433 | each server has a read and write socket end). |
1358 | |
1434 | |
1359 | I<create> is the time it takes to create a socketpair (which is |
1435 | I<create> is the time it takes to create a socket pair (which is |
1360 | nontrivial) and two watchers: an I/O watcher and a timeout watcher. |
1436 | nontrivial) and two watchers: an I/O watcher and a timeout watcher. |
1361 | |
1437 | |
1362 | I<request>, the most important value, is the time it takes to handle a |
1438 | I<request>, the most important value, is the time it takes to handle a |
1363 | single "request", that is, reading the token from the pipe and forwarding |
1439 | single "request", that is, reading the token from the pipe and forwarding |
1364 | it to another server. This includes deleting the old timeout and creating |
1440 | it to another server. This includes deleting the old timeout and creating |
… | |
… | |
1437 | speed most when you have lots of watchers, not when you only have a few of |
1513 | speed most when you have lots of watchers, not when you only have a few of |
1438 | them). |
1514 | them). |
1439 | |
1515 | |
1440 | EV is again fastest. |
1516 | EV is again fastest. |
1441 | |
1517 | |
1442 | Perl again comes second. It is noticably faster than the C-based event |
1518 | Perl again comes second. It is noticeably faster than the C-based event |
1443 | loops Event and Glib, although the difference is too small to really |
1519 | loops Event and Glib, although the difference is too small to really |
1444 | matter. |
1520 | matter. |
1445 | |
1521 | |
1446 | POE also performs much better in this case, but is is still far behind the |
1522 | POE also performs much better in this case, but is is still far behind the |
1447 | others. |
1523 | others. |
… | |
… | |
1487 | probably even less useful to an attacker than PERL_ANYEVENT_MODEL). |
1563 | probably even less useful to an attacker than PERL_ANYEVENT_MODEL). |
1488 | |
1564 | |
1489 | |
1565 | |
1490 | =head1 SEE ALSO |
1566 | =head1 SEE ALSO |
1491 | |
1567 | |
|
|
1568 | Utility functions: L<AnyEvent::Util>. |
|
|
1569 | |
1492 | Event modules: L<EV>, L<EV::Glib>, L<Glib::EV>, L<Event>, L<Glib::Event>, |
1570 | Event modules: L<EV>, L<EV::Glib>, L<Glib::EV>, L<Event>, L<Glib::Event>, |
1493 | L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>. |
1571 | L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>. |
1494 | |
1572 | |
1495 | Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>, |
1573 | Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>, |
1496 | L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>, |
1574 | L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>, |
1497 | L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>, |
1575 | L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>, |
1498 | L<AnyEvent::Impl::POE>. |
1576 | L<AnyEvent::Impl::POE>. |
1499 | |
1577 | |
|
|
1578 | Non-blocking file handles, sockets, TCP clients and |
|
|
1579 | servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>. |
|
|
1580 | |
|
|
1581 | Asynchronous DNS: L<AnyEvent::DNS>. |
|
|
1582 | |
1500 | Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>, |
1583 | Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>, |
1501 | |
1584 | |
1502 | Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>. |
1585 | Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>, L<AnyEvent::DNS>. |
1503 | |
1586 | |
1504 | |
1587 | |
1505 | =head1 AUTHOR |
1588 | =head1 AUTHOR |
1506 | |
1589 | |
1507 | Marc Lehmann <schmorp@schmorp.de> |
1590 | Marc Lehmann <schmorp@schmorp.de> |