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1=head1 NAME 1=head1 => NAME
2 2
3AnyEvent - provide framework for multiple event loops 3AnyEvent - provide framework for multiple event loops
4 4
5EV, Event, Coro::EV, Coro::Event, Glib, Tk, Perl, Event::Lib, Qt, POE - various supported event loops 5EV, Event, Glib, Tk, Perl, Event::Lib, Qt, POE - various supported event loops
6 6
7=head1 SYNOPSIS 7=head1 SYNOPSIS
8 8
9 use AnyEvent; 9 use AnyEvent;
10 10
15 my $w = AnyEvent->timer (after => $seconds, cb => sub { 15 my $w = AnyEvent->timer (after => $seconds, cb => sub {
16 ... 16 ...
17 }); 17 });
18 18
19 my $w = AnyEvent->condvar; # stores whether a condition was flagged 19 my $w = AnyEvent->condvar; # stores whether a condition was flagged
20 $w->send; # wake up current and all future recv's
20 $w->wait; # enters "main loop" till $condvar gets ->broadcast 21 $w->recv; # enters "main loop" till $condvar gets ->send
21 $w->broadcast; # wake up current and all future wait's
22 22
23=head1 WHY YOU SHOULD USE THIS MODULE (OR NOT) 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?
57as those use one of the supported event loops. It is trivial to add new 57as those use one of the supported event loops. It is trivial to add new
58event loops to AnyEvent, too, so it is future-proof). 58event loops to AnyEvent, too, so it is future-proof).
59 59
60In addition to being free of having to use I<the one and only true event 60In addition to being free of having to use I<the one and only true event
61model>, AnyEvent also is free of bloat and policy: with POE or similar 61model>, AnyEvent also is free of bloat and policy: with POE or similar
62modules, you get an enourmous amount of code and strict rules you have to 62modules, you get an enormous amount of code and strict rules you have to
63follow. AnyEvent, on the other hand, is lean and up to the point, by only 63follow. AnyEvent, on the other hand, is lean and up to the point, by only
64offering the functionality that is necessary, in as thin as a wrapper as 64offering the functionality that is necessary, in as thin as a wrapper as
65technically possible. 65technically possible.
66 66
67Of course, if you want lots of policy (this can arguably be somewhat 67Of course, if you want lots of policy (this can arguably be somewhat
78The interface itself is vaguely similar, but not identical to the L<Event> 78The interface itself is vaguely similar, but not identical to the L<Event>
79module. 79module.
80 80
81During the first call of any watcher-creation method, the module tries 81During the first call of any watcher-creation method, the module tries
82to detect the currently loaded event loop by probing whether one of the 82to detect the currently loaded event loop by probing whether one of the
83following modules is already loaded: L<Coro::EV>, L<Coro::Event>, L<EV>, 83following modules is already loaded: L<EV>,
84L<Event>, L<Glib>, L<AnyEvent::Impl::Perl>, L<Tk>, L<Event::Lib>, L<Qt>, 84L<Event>, L<Glib>, L<AnyEvent::Impl::Perl>, L<Tk>, L<Event::Lib>, L<Qt>,
85L<POE>. The first one found is used. If none are found, the module tries 85L<POE>. The first one found is used. If none are found, the module tries
86to load these modules (excluding Tk, Event::Lib, Qt and POE as the pure perl 86to load these modules (excluding Tk, Event::Lib, Qt and POE as the pure perl
87adaptor should always succeed) in the order given. The first one that can 87adaptor should always succeed) in the order given. The first one that can
88be successfully loaded will be used. If, after this, still none could be 88be successfully loaded will be used. If, after this, still none could be
108 108
109=head1 WATCHERS 109=head1 WATCHERS
110 110
111AnyEvent has the central concept of a I<watcher>, which is an object that 111AnyEvent has the central concept of a I<watcher>, which is an object that
112stores relevant data for each kind of event you are waiting for, such as 112stores relevant data for each kind of event you are waiting for, such as
113the callback to call, the filehandle to watch, etc. 113the callback to call, the file handle to watch, etc.
114 114
115These watchers are normal Perl objects with normal Perl lifetime. After 115These watchers are normal Perl objects with normal Perl lifetime. After
116creating a watcher it will immediately "watch" for events and invoke the 116creating a watcher it will immediately "watch" for events and invoke the
117callback when the event occurs (of course, only when the event model 117callback when the event occurs (of course, only when the event model
118is in control). 118is in control).
237 237
238Although the callback might get passed parameters, their value and 238Although the callback might get passed parameters, their value and
239presence is undefined and you cannot rely on them. Portable AnyEvent 239presence is undefined and you cannot rely on them. Portable AnyEvent
240callbacks cannot use arguments passed to signal watcher callbacks. 240callbacks cannot use arguments passed to signal watcher callbacks.
241 241
242Multiple signal occurances can be clumped together into one callback 242Multiple signal occurrences can be clumped together into one callback
243invocation, and callback invocation will be synchronous. synchronous means 243invocation, and callback invocation will be synchronous. Synchronous means
244that it might take a while until the signal gets handled by the process, 244that it might take a while until the signal gets handled by the process,
245but it is guarenteed not to interrupt any other callbacks. 245but it is guaranteed not to interrupt any other callbacks.
246 246
247The main advantage of using these watchers is that you can share a signal 247The main advantage of using these watchers is that you can share a signal
248between multiple watchers. 248between multiple watchers.
249 249
250This watcher might use C<%SIG>, so programs overwriting those signals 250This watcher might use C<%SIG>, so programs overwriting those signals
279 279
280Example: fork a process and wait for it 280Example: fork a process and wait for it
281 281
282 my $done = AnyEvent->condvar; 282 my $done = AnyEvent->condvar;
283 283
284 AnyEvent::detect; # force event module to be initialised
285
286 my $pid = fork or exit 5; 284 my $pid = fork or exit 5;
287 285
288 my $w = AnyEvent->child ( 286 my $w = AnyEvent->child (
289 pid => $pid, 287 pid => $pid,
290 cb => sub { 288 cb => sub {
291 my ($pid, $status) = @_; 289 my ($pid, $status) = @_;
292 warn "pid $pid exited with status $status"; 290 warn "pid $pid exited with status $status";
293 $done->broadcast; 291 $done->send;
294 }, 292 },
295 ); 293 );
296 294
297 # do something else, then wait for process exit 295 # do something else, then wait for process exit
298 $done->wait; 296 $done->recv;
299 297
300=head2 CONDITION VARIABLES 298=head2 CONDITION VARIABLES
301 299
300If you are familiar with some event loops you will know that all of them
301require you to run some blocking "loop", "run" or similar function that
302will actively watch for new events and call your callbacks.
303
304AnyEvent is different, it expects somebody else to run the event loop and
305will only block when necessary (usually when told by the user).
306
307The instrument to do that is called a "condition variable", so called
308because they represent a condition that must become true.
309
302Condition variables can be created by calling the C<< AnyEvent->condvar >> 310Condition variables can be created by calling the C<< AnyEvent->condvar
303method without any arguments. 311>> method, usually without arguments. The only argument pair allowed is
312C<cb>, which specifies a callback to be called when the condition variable
313becomes true.
304 314
305A condition variable waits for a condition - precisely that the C<< 315After creation, the condition variable is "false" until it becomes "true"
306->broadcast >> method has been called. 316by calling the C<send> method (or calling the condition variable as if it
317were a callback, read about the caveats in the description for the C<<
318->send >> method).
307 319
308They are very useful to signal that a condition has been fulfilled, for 320Condition variables are similar to callbacks, except that you can
321optionally wait for them. They can also be called merge points - points
322in time where multiple outstanding events have been processed. And yet
323another way to call them is transactions - each condition variable can be
324used to represent a transaction, which finishes at some point and delivers
325a result.
326
327Condition variables are very useful to signal that something has finished,
309example, if you write a module that does asynchronous http requests, 328for example, if you write a module that does asynchronous http requests,
310then a condition variable would be the ideal candidate to signal the 329then a condition variable would be the ideal candidate to signal the
311availability of results. 330availability of results. The user can either act when the callback is
331called or can synchronously C<< ->recv >> for the results.
312 332
313You can also use condition variables to block your main program until 333You can also use them to simulate traditional event loops - for example,
314an event occurs - for example, you could C<< ->wait >> in your main 334you can block your main program until an event occurs - for example, you
315program until the user clicks the Quit button in your app, which would C<< 335could C<< ->recv >> in your main program until the user clicks the Quit
316->broadcast >> the "quit" event. 336button of your app, which would C<< ->send >> the "quit" event.
317 337
318Note that condition variables recurse into the event loop - if you have 338Note that condition variables recurse into the event loop - if you have
319two pirces of code that call C<< ->wait >> in a round-robbin fashion, you 339two pieces of code that call C<< ->recv >> in a round-robin fashion, you
320lose. Therefore, condition variables are good to export to your caller, but 340lose. Therefore, condition variables are good to export to your caller, but
321you should avoid making a blocking wait yourself, at least in callbacks, 341you should avoid making a blocking wait yourself, at least in callbacks,
322as this asks for trouble. 342as this asks for trouble.
323 343
324This object has two methods: 344Condition variables are represented by hash refs in perl, and the keys
345used by AnyEvent itself are all named C<_ae_XXX> to make subclassing
346easy (it is often useful to build your own transaction class on top of
347AnyEvent). To subclass, use C<AnyEvent::CondVar> as base class and call
348it's C<new> method in your own C<new> method.
349
350There are two "sides" to a condition variable - the "producer side" which
351eventually calls C<< -> send >>, and the "consumer side", which waits
352for the send to occur.
353
354Example: wait for a timer.
355
356 # wait till the result is ready
357 my $result_ready = AnyEvent->condvar;
358
359 # do something such as adding a timer
360 # or socket watcher the calls $result_ready->send
361 # when the "result" is ready.
362 # in this case, we simply use a timer:
363 my $w = AnyEvent->timer (
364 after => 1,
365 cb => sub { $result_ready->send },
366 );
367
368 # this "blocks" (while handling events) till the callback
369 # calls send
370 $result_ready->recv;
371
372Example: wait for a timer, but take advantage of the fact that
373condition variables are also code references.
374
375 my $done = AnyEvent->condvar;
376 my $delay = AnyEvent->timer (after => 5, cb => $done);
377 $done->recv;
378
379=head3 METHODS FOR PRODUCERS
380
381These methods should only be used by the producing side, i.e. the
382code/module that eventually sends the signal. Note that it is also
383the producer side which creates the condvar in most cases, but it isn't
384uncommon for the consumer to create it as well.
325 385
326=over 4 386=over 4
327 387
388=item $cv->send (...)
389
390Flag the condition as ready - a running C<< ->recv >> and all further
391calls to C<recv> will (eventually) return after this method has been
392called. If nobody is waiting the send will be remembered.
393
394If a callback has been set on the condition variable, it is called
395immediately from within send.
396
397Any arguments passed to the C<send> call will be returned by all
398future C<< ->recv >> calls.
399
400Condition variables are overloaded so one can call them directly
401(as a code reference). Calling them directly is the same as calling
402C<send>. Note, however, that many C-based event loops do not handle
403overloading, so as tempting as it may be, passing a condition variable
404instead of a callback does not work. Both the pure perl and EV loops
405support overloading, however, as well as all functions that use perl to
406invoke a callback (as in L<AnyEvent::Socket> and L<AnyEvent::DNS> for
407example).
408
409=item $cv->croak ($error)
410
411Similar to send, but causes all call's to C<< ->recv >> to invoke
412C<Carp::croak> with the given error message/object/scalar.
413
414This can be used to signal any errors to the condition variable
415user/consumer.
416
417=item $cv->begin ([group callback])
418
328=item $cv->wait 419=item $cv->end
329 420
330Wait (blocking if necessary) until the C<< ->broadcast >> method has been 421These two methods are EXPERIMENTAL and MIGHT CHANGE.
422
423These two methods can be used to combine many transactions/events into
424one. For example, a function that pings many hosts in parallel might want
425to use a condition variable for the whole process.
426
427Every call to C<< ->begin >> will increment a counter, and every call to
428C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end
429>>, the (last) callback passed to C<begin> will be executed. That callback
430is I<supposed> to call C<< ->send >>, but that is not required. If no
431callback was set, C<send> will be called without any arguments.
432
433Let's clarify this with the ping example:
434
435 my $cv = AnyEvent->condvar;
436
437 my %result;
438 $cv->begin (sub { $cv->send (\%result) });
439
440 for my $host (@list_of_hosts) {
441 $cv->begin;
442 ping_host_then_call_callback $host, sub {
443 $result{$host} = ...;
444 $cv->end;
445 };
446 }
447
448 $cv->end;
449
450This code fragment supposedly pings a number of hosts and calls
451C<send> after results for all then have have been gathered - in any
452order. To achieve this, the code issues a call to C<begin> when it starts
453each ping request and calls C<end> when it has received some result for
454it. Since C<begin> and C<end> only maintain a counter, the order in which
455results arrive is not relevant.
456
457There is an additional bracketing call to C<begin> and C<end> outside the
458loop, which serves two important purposes: first, it sets the callback
459to be called once the counter reaches C<0>, and second, it ensures that
460C<send> is called even when C<no> hosts are being pinged (the loop
461doesn't execute once).
462
463This is the general pattern when you "fan out" into multiple subrequests:
464use an outer C<begin>/C<end> pair to set the callback and ensure C<end>
465is called at least once, and then, for each subrequest you start, call
466C<begin> and for each subrequest you finish, call C<end>.
467
468=back
469
470=head3 METHODS FOR CONSUMERS
471
472These methods should only be used by the consuming side, i.e. the
473code awaits the condition.
474
475=over 4
476
477=item $cv->recv
478
479Wait (blocking if necessary) until the C<< ->send >> or C<< ->croak
331called on c<$cv>, while servicing other watchers normally. 480>> methods have been called on c<$cv>, while servicing other watchers
481normally.
332 482
333You can only wait once on a condition - additional calls will return 483You can only wait once on a condition - additional calls are valid but
334immediately. 484will return immediately.
485
486If an error condition has been set by calling C<< ->croak >>, then this
487function will call C<croak>.
488
489In list context, all parameters passed to C<send> will be returned,
490in scalar context only the first one will be returned.
335 491
336Not all event models support a blocking wait - some die in that case 492Not all event models support a blocking wait - some die in that case
337(programs might want to do that to stay interactive), so I<if you are 493(programs might want to do that to stay interactive), so I<if you are
338using this from a module, never require a blocking wait>, but let the 494using this from a module, never require a blocking wait>, but let the
339caller decide whether the call will block or not (for example, by coupling 495caller decide whether the call will block or not (for example, by coupling
340condition variables with some kind of request results and supporting 496condition variables with some kind of request results and supporting
341callbacks so the caller knows that getting the result will not block, 497callbacks so the caller knows that getting the result will not block,
342while still suppporting blocking waits if the caller so desires). 498while still supporting blocking waits if the caller so desires).
343 499
344Another reason I<never> to C<< ->wait >> in a module is that you cannot 500Another reason I<never> to C<< ->recv >> in a module is that you cannot
345sensibly have two C<< ->wait >>'s in parallel, as that would require 501sensibly have two C<< ->recv >>'s in parallel, as that would require
346multiple interpreters or coroutines/threads, none of which C<AnyEvent> 502multiple interpreters or coroutines/threads, none of which C<AnyEvent>
347can supply (the coroutine-aware backends L<AnyEvent::Impl::CoroEV> and 503can supply.
348L<AnyEvent::Impl::CoroEvent> explicitly support concurrent C<< ->wait >>'s
349from different coroutines, however).
350 504
351=item $cv->broadcast 505The L<Coro> module, however, I<can> and I<does> supply coroutines and, in
506fact, L<Coro::AnyEvent> replaces AnyEvent's condvars by coroutine-safe
507versions and also integrates coroutines into AnyEvent, making blocking
508C<< ->recv >> calls perfectly safe as long as they are done from another
509coroutine (one that doesn't run the event loop).
352 510
353Flag the condition as ready - a running C<< ->wait >> and all further 511You can ensure that C<< -recv >> never blocks by setting a callback and
354calls to C<wait> will (eventually) return after this method has been 512only calling C<< ->recv >> from within that callback (or at a later
355called. If nobody is waiting the broadcast will be remembered.. 513time). This will work even when the event loop does not support blocking
514waits otherwise.
515
516=item $bool = $cv->ready
517
518Returns true when the condition is "true", i.e. whether C<send> or
519C<croak> have been called.
520
521=item $cb = $cv->cb ([new callback])
522
523This is a mutator function that returns the callback set and optionally
524replaces it before doing so.
525
526The callback will be called when the condition becomes "true", i.e. when
527C<send> or C<croak> are called. Calling C<recv> inside the callback
528or at any later time is guaranteed not to block.
356 529
357=back 530=back
358
359Example:
360
361 # wait till the result is ready
362 my $result_ready = AnyEvent->condvar;
363
364 # do something such as adding a timer
365 # or socket watcher the calls $result_ready->broadcast
366 # when the "result" is ready.
367 # in this case, we simply use a timer:
368 my $w = AnyEvent->timer (
369 after => 1,
370 cb => sub { $result_ready->broadcast },
371 );
372
373 # this "blocks" (while handling events) till the watcher
374 # calls broadcast
375 $result_ready->wait;
376 531
377=head1 GLOBAL VARIABLES AND FUNCTIONS 532=head1 GLOBAL VARIABLES AND FUNCTIONS
378 533
379=over 4 534=over 4
380 535
386C<AnyEvent::Impl:xxx> modules, but can be any other class in the case 541C<AnyEvent::Impl:xxx> modules, but can be any other class in the case
387AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode>). 542AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode>).
388 543
389The known classes so far are: 544The known classes so far are:
390 545
391 AnyEvent::Impl::CoroEV based on Coro::EV, best choice.
392 AnyEvent::Impl::CoroEvent based on Coro::Event, second best choice.
393 AnyEvent::Impl::EV based on EV (an interface to libev, best choice). 546 AnyEvent::Impl::EV based on EV (an interface to libev, best choice).
394 AnyEvent::Impl::Event based on Event, second best choice. 547 AnyEvent::Impl::Event based on Event, second best choice.
395 AnyEvent::Impl::Perl pure-perl implementation, fast and portable. 548 AnyEvent::Impl::Perl pure-perl implementation, fast and portable.
396 AnyEvent::Impl::Glib based on Glib, third-best choice. 549 AnyEvent::Impl::Glib based on Glib, third-best choice.
397 AnyEvent::Impl::Tk based on Tk, very bad choice. 550 AnyEvent::Impl::Tk based on Tk, very bad choice.
414Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model 567Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model
415if necessary. You should only call this function right before you would 568if necessary. You should only call this function right before you would
416have created an AnyEvent watcher anyway, that is, as late as possible at 569have created an AnyEvent watcher anyway, that is, as late as possible at
417runtime. 570runtime.
418 571
572=item $guard = AnyEvent::post_detect { BLOCK }
573
574Arranges for the code block to be executed as soon as the event model is
575autodetected (or immediately if this has already happened).
576
577If called in scalar or list context, then it creates and returns an object
578that automatically removes the callback again when it is destroyed. See
579L<Coro::BDB> for a case where this is useful.
580
581=item @AnyEvent::post_detect
582
583If there are any code references in this array (you can C<push> to it
584before or after loading AnyEvent), then they will called directly after
585the event loop has been chosen.
586
587You should check C<$AnyEvent::MODEL> before adding to this array, though:
588if it contains a true value then the event loop has already been detected,
589and the array will be ignored.
590
591Best use C<AnyEvent::post_detect { BLOCK }> instead.
592
419=back 593=back
420 594
421=head1 WHAT TO DO IN A MODULE 595=head1 WHAT TO DO IN A MODULE
422 596
423As a module author, you should C<use AnyEvent> and call AnyEvent methods 597As a module author, you should C<use AnyEvent> and call AnyEvent methods
426Be careful when you create watchers in the module body - AnyEvent will 600Be careful when you create watchers in the module body - AnyEvent will
427decide which event module to use as soon as the first method is called, so 601decide which event module to use as soon as the first method is called, so
428by calling AnyEvent in your module body you force the user of your module 602by calling AnyEvent in your module body you force the user of your module
429to load the event module first. 603to load the event module first.
430 604
431Never call C<< ->wait >> on a condition variable unless you I<know> that 605Never call C<< ->recv >> on a condition variable unless you I<know> that
432the C<< ->broadcast >> method has been called on it already. This is 606the C<< ->send >> method has been called on it already. This is
433because it will stall the whole program, and the whole point of using 607because it will stall the whole program, and the whole point of using
434events is to stay interactive. 608events is to stay interactive.
435 609
436It is fine, however, to call C<< ->wait >> when the user of your module 610It is fine, however, to call C<< ->recv >> when the user of your module
437requests it (i.e. if you create a http request object ad have a method 611requests it (i.e. if you create a http request object ad have a method
438called C<results> that returns the results, it should call C<< ->wait >> 612called C<results> that returns the results, it should call C<< ->recv >>
439freely, as the user of your module knows what she is doing. always). 613freely, as the user of your module knows what she is doing. always).
440 614
441=head1 WHAT TO DO IN THE MAIN PROGRAM 615=head1 WHAT TO DO IN THE MAIN PROGRAM
442 616
443There will always be a single main program - the only place that should 617There will always be a single main program - the only place that should
445 619
446If it doesn't care, it can just "use AnyEvent" and use it itself, or not 620If it doesn't care, it can just "use AnyEvent" and use it itself, or not
447do anything special (it does not need to be event-based) and let AnyEvent 621do anything special (it does not need to be event-based) and let AnyEvent
448decide which implementation to chose if some module relies on it. 622decide which implementation to chose if some module relies on it.
449 623
450If the main program relies on a specific event model. For example, in 624If the main program relies on a specific event model - for example, in
451Gtk2 programs you have to rely on the Glib module. You should load the 625Gtk2 programs you have to rely on the Glib module - you should load the
452event module before loading AnyEvent or any module that uses it: generally 626event module before loading AnyEvent or any module that uses it: generally
453speaking, you should load it as early as possible. The reason is that 627speaking, you should load it as early as possible. The reason is that
454modules might create watchers when they are loaded, and AnyEvent will 628modules might create watchers when they are loaded, and AnyEvent will
455decide on the event model to use as soon as it creates watchers, and it 629decide on the event model to use as soon as it creates watchers, and it
456might chose the wrong one unless you load the correct one yourself. 630might chose the wrong one unless you load the correct one yourself.
457 631
458You can chose to use a rather inefficient pure-perl implementation by 632You can chose to use a pure-perl implementation by loading the
459loading the C<AnyEvent::Impl::Perl> module, which gives you similar 633C<AnyEvent::Impl::Perl> module, which gives you similar behaviour
460behaviour everywhere, but letting AnyEvent chose is generally better. 634everywhere, but letting AnyEvent chose the model is generally better.
635
636=head2 MAINLOOP EMULATION
637
638Sometimes (often for short test scripts, or even standalone programs who
639only want to use AnyEvent), you do not want to run a specific event loop.
640
641In that case, you can use a condition variable like this:
642
643 AnyEvent->condvar->recv;
644
645This has the effect of entering the event loop and looping forever.
646
647Note that usually your program has some exit condition, in which case
648it is better to use the "traditional" approach of storing a condition
649variable somewhere, waiting for it, and sending it when the program should
650exit cleanly.
651
461 652
462=head1 OTHER MODULES 653=head1 OTHER MODULES
463 654
464The following is a non-exhaustive list of additional modules that use 655The following is a non-exhaustive list of additional modules that use
465AnyEvent and can therefore be mixed easily with other AnyEvent modules 656AnyEvent and can therefore be mixed easily with other AnyEvent modules
477 668
478Provide read and write buffers and manages watchers for reads and writes. 669Provide read and write buffers and manages watchers for reads and writes.
479 670
480=item L<AnyEvent::Socket> 671=item L<AnyEvent::Socket>
481 672
482Provides a means to do non-blocking connects, accepts etc. 673Provides various utility functions for (internet protocol) sockets,
674addresses and name resolution. Also functions to create non-blocking tcp
675connections or tcp servers, with IPv6 and SRV record support and more.
676
677=item L<AnyEvent::DNS>
678
679Provides rich asynchronous DNS resolver capabilities.
483 680
484=item L<AnyEvent::HTTPD> 681=item L<AnyEvent::HTTPD>
485 682
486Provides a simple web application server framework. 683Provides a simple web application server framework.
487
488=item L<AnyEvent::DNS>
489
490Provides asynchronous DNS resolver capabilities, beyond what
491L<AnyEvent::Util> offers.
492 684
493=item L<AnyEvent::FastPing> 685=item L<AnyEvent::FastPing>
494 686
495The fastest ping in the west. 687The fastest ping in the west.
496 688
511 703
512High level API for event-based execution flow control. 704High level API for event-based execution flow control.
513 705
514=item L<Coro> 706=item L<Coro>
515 707
516Has special support for AnyEvent. 708Has special support for AnyEvent via L<Coro::AnyEvent>.
709
710=item L<AnyEvent::AIO>, L<IO::AIO>
711
712Truly asynchronous I/O, should be in the toolbox of every event
713programmer. AnyEvent::AIO transparently fuses IO::AIO and AnyEvent
714together.
715
716=item L<AnyEvent::BDB>, L<BDB>
717
718Truly asynchronous Berkeley DB access. AnyEvent::AIO transparently fuses
719IO::AIO and AnyEvent together.
517 720
518=item L<IO::Lambda> 721=item L<IO::Lambda>
519 722
520The lambda approach to I/O - don't ask, look there. Can use AnyEvent. 723The lambda approach to I/O - don't ask, look there. Can use AnyEvent.
521
522=item L<IO::AIO>
523
524Truly asynchronous I/O, should be in the toolbox of every event
525programmer. Can be trivially made to use AnyEvent.
526
527=item L<BDB>
528
529Truly asynchronous Berkeley DB access. Can be trivially made to use
530AnyEvent.
531 724
532=back 725=back
533 726
534=cut 727=cut
535 728
538no warnings; 731no warnings;
539use strict; 732use strict;
540 733
541use Carp; 734use Carp;
542 735
543our $VERSION = '3.3'; 736our $VERSION = '4.05';
544our $MODEL; 737our $MODEL;
545 738
546our $AUTOLOAD; 739our $AUTOLOAD;
547our @ISA; 740our @ISA;
548 741
742our @REGISTRY;
743
744our $WIN32;
745
746BEGIN {
747 my $win32 = ! ! ($^O =~ /mswin32/i);
748 eval "sub WIN32(){ $win32 }";
749}
750
549our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1; 751our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1;
550 752
551our @REGISTRY; 753our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred
754
755{
756 my $idx;
757 $PROTOCOL{$_} = ++$idx
758 for reverse split /\s*,\s*/,
759 $ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";
760}
552 761
553my @models = ( 762my @models = (
554 [Coro::EV:: => AnyEvent::Impl::CoroEV::],
555 [Coro::Event:: => AnyEvent::Impl::CoroEvent::],
556 [EV:: => AnyEvent::Impl::EV::], 763 [EV:: => AnyEvent::Impl::EV::],
557 [Event:: => AnyEvent::Impl::Event::], 764 [Event:: => AnyEvent::Impl::Event::],
558 [Tk:: => AnyEvent::Impl::Tk::],
559 [Wx:: => AnyEvent::Impl::POE::],
560 [Prima:: => AnyEvent::Impl::POE::],
561 [AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::], 765 [AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::],
562 # everything below here will not be autoprobed as the pureperl backend should work everywhere 766 # everything below here will not be autoprobed
563 [Glib:: => AnyEvent::Impl::Glib::], 767 # as the pureperl backend should work everywhere
768 # and is usually faster
769 [Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
770 [Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers
564 [Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy 771 [Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
565 [Qt:: => AnyEvent::Impl::Qt::], # requires special main program 772 [Qt:: => AnyEvent::Impl::Qt::], # requires special main program
566 [POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza 773 [POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
774 [Wx:: => AnyEvent::Impl::POE::],
775 [Prima:: => AnyEvent::Impl::POE::],
567); 776);
568 777
569our %method = map +($_ => 1), qw(io timer signal child condvar broadcast wait one_event DESTROY); 778our %method = map +($_ => 1), qw(io timer signal child condvar one_event DESTROY);
779
780our @post_detect;
781
782sub post_detect(&) {
783 my ($cb) = @_;
784
785 if ($MODEL) {
786 $cb->();
787
788 1
789 } else {
790 push @post_detect, $cb;
791
792 defined wantarray
793 ? bless \$cb, "AnyEvent::Util::PostDetect"
794 : ()
795 }
796}
797
798sub AnyEvent::Util::PostDetect::DESTROY {
799 @post_detect = grep $_ != ${$_[0]}, @post_detect;
800}
570 801
571sub detect() { 802sub detect() {
572 unless ($MODEL) { 803 unless ($MODEL) {
573 no strict 'refs'; 804 no strict 'refs';
805 local $SIG{__DIE__};
574 806
575 if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) { 807 if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {
576 my $model = "AnyEvent::Impl::$1"; 808 my $model = "AnyEvent::Impl::$1";
577 if (eval "require $model") { 809 if (eval "require $model") {
578 $MODEL = $model; 810 $MODEL = $model;
608 last; 840 last;
609 } 841 }
610 } 842 }
611 843
612 $MODEL 844 $MODEL
613 or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV (or Coro+EV), Event (or Coro+Event) or Glib."; 845 or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.";
614 } 846 }
615 } 847 }
616 848
617 unshift @ISA, $MODEL; 849 unshift @ISA, $MODEL;
618 push @{"$MODEL\::ISA"}, "AnyEvent::Base"; 850 push @{"$MODEL\::ISA"}, "AnyEvent::Base";
851
852 (shift @post_detect)->() while @post_detect;
619 } 853 }
620 854
621 $MODEL 855 $MODEL
622} 856}
623 857
633 $class->$func (@_); 867 $class->$func (@_);
634} 868}
635 869
636package AnyEvent::Base; 870package AnyEvent::Base;
637 871
638# default implementation for ->condvar, ->wait, ->broadcast 872# default implementation for ->condvar
639 873
640sub condvar { 874sub condvar {
641 bless \my $flag, "AnyEvent::Base::CondVar" 875 bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, AnyEvent::CondVar::
642}
643
644sub AnyEvent::Base::CondVar::broadcast {
645 ${$_[0]}++;
646}
647
648sub AnyEvent::Base::CondVar::wait {
649 AnyEvent->one_event while !${$_[0]};
650} 876}
651 877
652# default implementation for ->signal 878# default implementation for ->signal
653 879
654our %SIG_CB; 880our %SIG_CB;
707 or Carp::croak "required option 'pid' is missing"; 933 or Carp::croak "required option 'pid' is missing";
708 934
709 $PID_CB{$pid}{$arg{cb}} = $arg{cb}; 935 $PID_CB{$pid}{$arg{cb}} = $arg{cb};
710 936
711 unless ($WNOHANG) { 937 unless ($WNOHANG) {
712 $WNOHANG = eval { require POSIX; &POSIX::WNOHANG } || 1; 938 $WNOHANG = eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1;
713 } 939 }
714 940
715 unless ($CHLD_W) { 941 unless ($CHLD_W) {
716 $CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld); 942 $CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld);
717 # child could be a zombie already, so make at least one round 943 # child could be a zombie already, so make at least one round
727 delete $PID_CB{$pid}{$cb}; 953 delete $PID_CB{$pid}{$cb};
728 delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} }; 954 delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };
729 955
730 undef $CHLD_W unless keys %PID_CB; 956 undef $CHLD_W unless keys %PID_CB;
731} 957}
958
959package AnyEvent::CondVar;
960
961our @ISA = AnyEvent::CondVar::Base::;
962
963package AnyEvent::CondVar::Base;
964
965use overload
966 '&{}' => sub { my $self = shift; sub { $self->send (@_) } },
967 fallback => 1;
968
969sub _send {
970 # nop
971}
972
973sub send {
974 my $cv = shift;
975 $cv->{_ae_sent} = [@_];
976 (delete $cv->{_ae_cb})->($cv) if $cv->{_ae_cb};
977 $cv->_send;
978}
979
980sub croak {
981 $_[0]{_ae_croak} = $_[1];
982 $_[0]->send;
983}
984
985sub ready {
986 $_[0]{_ae_sent}
987}
988
989sub _wait {
990 AnyEvent->one_event while !$_[0]{_ae_sent};
991}
992
993sub recv {
994 $_[0]->_wait;
995
996 Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak};
997 wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0]
998}
999
1000sub cb {
1001 $_[0]{_ae_cb} = $_[1] if @_ > 1;
1002 $_[0]{_ae_cb}
1003}
1004
1005sub begin {
1006 ++$_[0]{_ae_counter};
1007 $_[0]{_ae_end_cb} = $_[1] if @_ > 1;
1008}
1009
1010sub end {
1011 return if --$_[0]{_ae_counter};
1012 &{ $_[0]{_ae_end_cb} || sub { $_[0]->send } };
1013}
1014
1015# undocumented/compatibility with pre-3.4
1016*broadcast = \&send;
1017*wait = \&_wait;
732 1018
733=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE 1019=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE
734 1020
735This is an advanced topic that you do not normally need to use AnyEvent in 1021This is an advanced topic that you do not normally need to use AnyEvent in
736a module. This section is only of use to event loop authors who want to 1022a module. This section is only of use to event loop authors who want to
793model it chooses. 1079model it chooses.
794 1080
795=item C<PERL_ANYEVENT_MODEL> 1081=item C<PERL_ANYEVENT_MODEL>
796 1082
797This can be used to specify the event model to be used by AnyEvent, before 1083This can be used to specify the event model to be used by AnyEvent, before
798autodetection and -probing kicks in. It must be a string consisting 1084auto detection and -probing kicks in. It must be a string consisting
799entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended 1085entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended
800and the resulting module name is loaded and if the load was successful, 1086and the resulting module name is loaded and if the load was successful,
801used as event model. If it fails to load AnyEvent will proceed with 1087used as event model. If it fails to load AnyEvent will proceed with
802autodetection and -probing. 1088auto detection and -probing.
803 1089
804This functionality might change in future versions. 1090This functionality might change in future versions.
805 1091
806For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you 1092For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you
807could start your program like this: 1093could start your program like this:
808 1094
809 PERL_ANYEVENT_MODEL=Perl perl ... 1095 PERL_ANYEVENT_MODEL=Perl perl ...
1096
1097=item C<PERL_ANYEVENT_PROTOCOLS>
1098
1099Used by both L<AnyEvent::DNS> and L<AnyEvent::Socket> to determine preferences
1100for IPv4 or IPv6. The default is unspecified (and might change, or be the result
1101of auto probing).
1102
1103Must be set to a comma-separated list of protocols or address families,
1104current supported: C<ipv4> and C<ipv6>. Only protocols mentioned will be
1105used, and preference will be given to protocols mentioned earlier in the
1106list.
1107
1108This variable can effectively be used for denial-of-service attacks
1109against local programs (e.g. when setuid), although the impact is likely
1110small, as the program has to handle connection errors already-
1111
1112Examples: C<PERL_ANYEVENT_PROTOCOLS=ipv4,ipv6> - prefer IPv4 over IPv6,
1113but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4>
1114- only support IPv4, never try to resolve or contact IPv6
1115addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or
1116IPv6, but prefer IPv6 over IPv4.
1117
1118=item C<PERL_ANYEVENT_EDNS0>
1119
1120Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension
1121for DNS. This extension is generally useful to reduce DNS traffic, but
1122some (broken) firewalls drop such DNS packets, which is why it is off by
1123default.
1124
1125Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce
1126EDNS0 in its DNS requests.
810 1127
811=back 1128=back
812 1129
813=head1 EXAMPLE PROGRAM 1130=head1 EXAMPLE PROGRAM
814 1131
825 poll => 'r', 1142 poll => 'r',
826 cb => sub { 1143 cb => sub {
827 warn "io event <$_[0]>\n"; # will always output <r> 1144 warn "io event <$_[0]>\n"; # will always output <r>
828 chomp (my $input = <STDIN>); # read a line 1145 chomp (my $input = <STDIN>); # read a line
829 warn "read: $input\n"; # output what has been read 1146 warn "read: $input\n"; # output what has been read
830 $cv->broadcast if $input =~ /^q/i; # quit program if /^q/i 1147 $cv->send if $input =~ /^q/i; # quit program if /^q/i
831 }, 1148 },
832 ); 1149 );
833 1150
834 my $time_watcher; # can only be used once 1151 my $time_watcher; # can only be used once
835 1152
840 }); 1157 });
841 } 1158 }
842 1159
843 new_timer; # create first timer 1160 new_timer; # create first timer
844 1161
845 $cv->wait; # wait until user enters /^q/i 1162 $cv->recv; # wait until user enters /^q/i
846 1163
847=head1 REAL-WORLD EXAMPLE 1164=head1 REAL-WORLD EXAMPLE
848 1165
849Consider the L<Net::FCP> module. It features (among others) the following 1166Consider the L<Net::FCP> module. It features (among others) the following
850API calls, which are to freenet what HTTP GET requests are to http: 1167API calls, which are to freenet what HTTP GET requests are to http:
900 syswrite $txn->{fh}, $txn->{request} 1217 syswrite $txn->{fh}, $txn->{request}
901 or die "connection or write error"; 1218 or die "connection or write error";
902 $txn->{w} = AnyEvent->io (fh => $txn->{fh}, poll => 'r', cb => sub { $txn->fh_ready_r }); 1219 $txn->{w} = AnyEvent->io (fh => $txn->{fh}, poll => 'r', cb => sub { $txn->fh_ready_r });
903 1220
904Again, C<fh_ready_r> waits till all data has arrived, and then stores the 1221Again, C<fh_ready_r> waits till all data has arrived, and then stores the
905result and signals any possible waiters that the request ahs finished: 1222result and signals any possible waiters that the request has finished:
906 1223
907 sysread $txn->{fh}, $txn->{buf}, length $txn->{$buf}; 1224 sysread $txn->{fh}, $txn->{buf}, length $txn->{$buf};
908 1225
909 if (end-of-file or data complete) { 1226 if (end-of-file or data complete) {
910 $txn->{result} = $txn->{buf}; 1227 $txn->{result} = $txn->{buf};
911 $txn->{finished}->broadcast; 1228 $txn->{finished}->send;
912 $txb->{cb}->($txn) of $txn->{cb}; # also call callback 1229 $txb->{cb}->($txn) of $txn->{cb}; # also call callback
913 } 1230 }
914 1231
915The C<result> method, finally, just waits for the finished signal (if the 1232The C<result> method, finally, just waits for the finished signal (if the
916request was already finished, it doesn't wait, of course, and returns the 1233request was already finished, it doesn't wait, of course, and returns the
917data: 1234data:
918 1235
919 $txn->{finished}->wait; 1236 $txn->{finished}->recv;
920 return $txn->{result}; 1237 return $txn->{result};
921 1238
922The actual code goes further and collects all errors (C<die>s, exceptions) 1239The actual code goes further and collects all errors (C<die>s, exceptions)
923that occured during request processing. The C<result> method detects 1240that occurred during request processing. The C<result> method detects
924whether an exception as thrown (it is stored inside the $txn object) 1241whether an exception as thrown (it is stored inside the $txn object)
925and just throws the exception, which means connection errors and other 1242and just throws the exception, which means connection errors and other
926problems get reported tot he code that tries to use the result, not in a 1243problems get reported tot he code that tries to use the result, not in a
927random callback. 1244random callback.
928 1245
959 1276
960 my $quit = AnyEvent->condvar; 1277 my $quit = AnyEvent->condvar;
961 1278
962 $fcp->txn_client_get ($url)->cb (sub { 1279 $fcp->txn_client_get ($url)->cb (sub {
963 ... 1280 ...
964 $quit->broadcast; 1281 $quit->send;
965 }); 1282 });
966 1283
967 $quit->wait; 1284 $quit->recv;
968 1285
969 1286
970=head1 BENCHMARKS 1287=head1 BENCHMARKS
971 1288
972To give you an idea of the performance and overheads that AnyEvent adds 1289To give you an idea of the performance and overheads that AnyEvent adds
974of various event loops I prepared some benchmarks. 1291of various event loops I prepared some benchmarks.
975 1292
976=head2 BENCHMARKING ANYEVENT OVERHEAD 1293=head2 BENCHMARKING ANYEVENT OVERHEAD
977 1294
978Here is a benchmark of various supported event models used natively and 1295Here is a benchmark of various supported event models used natively and
979through anyevent. The benchmark creates a lot of timers (with a zero 1296through AnyEvent. The benchmark creates a lot of timers (with a zero
980timeout) and I/O watchers (watching STDOUT, a pty, to become writable, 1297timeout) and I/O watchers (watching STDOUT, a pty, to become writable,
981which it is), lets them fire exactly once and destroys them again. 1298which it is), lets them fire exactly once and destroys them again.
982 1299
983Source code for this benchmark is found as F<eg/bench> in the AnyEvent 1300Source code for this benchmark is found as F<eg/bench> in the AnyEvent
984distribution. 1301distribution.
1001all watchers, to avoid adding memory overhead. That means closure creation 1318all watchers, to avoid adding memory overhead. That means closure creation
1002and memory usage is not included in the figures. 1319and memory usage is not included in the figures.
1003 1320
1004I<invoke> is the time, in microseconds, used to invoke a simple 1321I<invoke> is the time, in microseconds, used to invoke a simple
1005callback. The callback simply counts down a Perl variable and after it was 1322callback. The callback simply counts down a Perl variable and after it was
1006invoked "watcher" times, it would C<< ->broadcast >> a condvar once to 1323invoked "watcher" times, it would C<< ->send >> a condvar once to
1007signal the end of this phase. 1324signal the end of this phase.
1008 1325
1009I<destroy> is the time, in microseconds, that it takes to destroy a single 1326I<destroy> is the time, in microseconds, that it takes to destroy a single
1010watcher. 1327watcher.
1011 1328
1107 1424
1108=back 1425=back
1109 1426
1110=head2 BENCHMARKING THE LARGE SERVER CASE 1427=head2 BENCHMARKING THE LARGE SERVER CASE
1111 1428
1112This benchmark atcually benchmarks the event loop itself. It works by 1429This benchmark actually benchmarks the event loop itself. It works by
1113creating a number of "servers": each server consists of a socketpair, a 1430creating a number of "servers": each server consists of a socket pair, a
1114timeout watcher that gets reset on activity (but never fires), and an I/O 1431timeout watcher that gets reset on activity (but never fires), and an I/O
1115watcher waiting for input on one side of the socket. Each time the socket 1432watcher waiting for input on one side of the socket. Each time the socket
1116watcher reads a byte it will write that byte to a random other "server". 1433watcher reads a byte it will write that byte to a random other "server".
1117 1434
1118The effect is that there will be a lot of I/O watchers, only part of which 1435The effect is that there will be a lot of I/O watchers, only part of which
1119are active at any one point (so there is a constant number of active 1436are active at any one point (so there is a constant number of active
1120fds for each loop iterstaion, but which fds these are is random). The 1437fds for each loop iteration, but which fds these are is random). The
1121timeout is reset each time something is read because that reflects how 1438timeout is reset each time something is read because that reflects how
1122most timeouts work (and puts extra pressure on the event loops). 1439most timeouts work (and puts extra pressure on the event loops).
1123 1440
1124In this benchmark, we use 10000 socketpairs (20000 sockets), of which 100 1441In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100
1125(1%) are active. This mirrors the activity of large servers with many 1442(1%) are active. This mirrors the activity of large servers with many
1126connections, most of which are idle at any one point in time. 1443connections, most of which are idle at any one point in time.
1127 1444
1128Source code for this benchmark is found as F<eg/bench2> in the AnyEvent 1445Source code for this benchmark is found as F<eg/bench2> in the AnyEvent
1129distribution. 1446distribution.
1131=head3 Explanation of the columns 1448=head3 Explanation of the columns
1132 1449
1133I<sockets> is the number of sockets, and twice the number of "servers" (as 1450I<sockets> is the number of sockets, and twice the number of "servers" (as
1134each server has a read and write socket end). 1451each server has a read and write socket end).
1135 1452
1136I<create> is the time it takes to create a socketpair (which is 1453I<create> is the time it takes to create a socket pair (which is
1137nontrivial) and two watchers: an I/O watcher and a timeout watcher. 1454nontrivial) and two watchers: an I/O watcher and a timeout watcher.
1138 1455
1139I<request>, the most important value, is the time it takes to handle a 1456I<request>, the most important value, is the time it takes to handle a
1140single "request", that is, reading the token from the pipe and forwarding 1457single "request", that is, reading the token from the pipe and forwarding
1141it to another server. This includes deleting the old timeout and creating 1458it to another server. This includes deleting the old timeout and creating
1214speed most when you have lots of watchers, not when you only have a few of 1531speed most when you have lots of watchers, not when you only have a few of
1215them). 1532them).
1216 1533
1217EV is again fastest. 1534EV is again fastest.
1218 1535
1219Perl again comes second. It is noticably faster than the C-based event 1536Perl again comes second. It is noticeably faster than the C-based event
1220loops Event and Glib, although the difference is too small to really 1537loops Event and Glib, although the difference is too small to really
1221matter. 1538matter.
1222 1539
1223POE also performs much better in this case, but is is still far behind the 1540POE also performs much better in this case, but is is still far behind the
1224others. 1541others.
1257 1574
1258 BEGIN { delete $ENV{PERL_ANYEVENT_MODEL} } 1575 BEGIN { delete $ENV{PERL_ANYEVENT_MODEL} }
1259 1576
1260 use AnyEvent; 1577 use AnyEvent;
1261 1578
1579Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can
1580be used to probe what backend is used and gain other information (which is
1581probably even less useful to an attacker than PERL_ANYEVENT_MODEL).
1582
1262 1583
1263=head1 SEE ALSO 1584=head1 SEE ALSO
1264 1585
1265Event modules: L<Coro::EV>, L<EV>, L<EV::Glib>, L<Glib::EV>, 1586Utility functions: L<AnyEvent::Util>.
1266L<Coro::Event>, L<Event>, L<Glib::Event>, L<Glib>, L<Coro>, L<Tk>, 1587
1588Event modules: L<EV>, L<EV::Glib>, L<Glib::EV>, L<Event>, L<Glib::Event>,
1267L<Event::Lib>, L<Qt>, L<POE>. 1589L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.
1268 1590
1269Implementations: L<AnyEvent::Impl::CoroEV>, L<AnyEvent::Impl::EV>, 1591Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,
1270L<AnyEvent::Impl::CoroEvent>, L<AnyEvent::Impl::Event>, L<AnyEvent::Impl::Glib>, 1592L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,
1271L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>, L<AnyEvent::Impl::EventLib>, 1593L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,
1272L<AnyEvent::Impl::Qt>, L<AnyEvent::Impl::POE>. 1594L<AnyEvent::Impl::POE>.
1273 1595
1596Non-blocking file handles, sockets, TCP clients and
1597servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>.
1598
1599Asynchronous DNS: L<AnyEvent::DNS>.
1600
1601Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>,
1602
1274Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>. 1603Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>, L<AnyEvent::DNS>.
1275 1604
1276 1605
1277=head1 AUTHOR 1606=head1 AUTHOR
1278 1607
1279 Marc Lehmann <schmorp@schmorp.de> 1608 Marc Lehmann <schmorp@schmorp.de>

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