[ViewVC] Diff of: cvs/AnyEvent/lib/AnyEvent.pm

Comparing AnyEvent/lib/AnyEvent.pm (file contents):
Revision 1.107 by root, Tue May 6 12:15:50 2008 UTC vs.
Revision 1.142 by root, Tue May 27 02:34:30 2008 UTC

…		…
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, Coro::EV, Coro::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
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 ->send	21	$w->recv; # enters "main loop" till $condvar gets ->send
21	$w->send; # 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
25	Glib, POE, IO::Async, Event... CPAN offers event models by the dozen	25	Glib, POE, IO::Async, Event... CPAN offers event models by the dozen
26	nowadays. So what is different about AnyEvent?	26	nowadays. So what is different about AnyEvent?
…		…
48	isn't itself. What's worse, all the potential users of your module are	48	isn't itself. What's worse, all the potential users of your module are
49	I<also> forced to use the same event loop you use.	49	I<also> forced to use the same event loop you use.
50		50
51	AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works	51	AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works
52	fine. AnyEvent + Tk works fine etc. etc. but none of these work together	52	fine. AnyEvent + Tk works fine etc. etc. but none of these work together
53	with the rest: POE + IO::Async? no go. Tk + Event? no go. Again: if	53	with the rest: POE + IO::Async? No go. Tk + Event? No go. Again: if
54	your module uses one of those, every user of your module has to use it,	54	your module uses one of those, every user of your module has to use it,
55	too. But if your module uses AnyEvent, it works transparently with all	55	too. But if your module uses AnyEvent, it works transparently with all
56	event models it supports (including stuff like POE and IO::Async, as long	56	event models it supports (including stuff like POE and IO::Async, as long
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, AnyEvent comes with a big (and fully optional!) toolbox
		68	of useful functionality, such as an asynchronous DNS resolver, 100%
		69	non-blocking connects (even with TLS/SSL, IPv6 and on broken platforms
		70	such as Windows) and lots of real-world knowledge and workarounds for
		71	platform bugs and differences.
		72
67	Of course, if you want lots of policy (this can arguably be somewhat	73	Now, if you I<do 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	74	useful) and you want to force your users to use the one and only event
69	model, you should I<not> use this module.	75	model, you should I<not> use this module.
70		76
71	=head1 DESCRIPTION	77	=head1 DESCRIPTION
72		78
…		…
78	The interface itself is vaguely similar, but not identical to the L<Event>	84	The interface itself is vaguely similar, but not identical to the L<Event>
79	module.	85	module.
80		86
81	During the first call of any watcher-creation method, the module tries	87	During the first call of any watcher-creation method, the module tries
82	to detect the currently loaded event loop by probing whether one of the	88	to detect the currently loaded event loop by probing whether one of the
83	following modules is already loaded: L<Coro::EV>, L<Coro::Event>, L<EV>,	89	following modules is already loaded: L<EV>,
84	L<Event>, L<Glib>, L<AnyEvent::Impl::Perl>, L<Tk>, L<Event::Lib>, L<Qt>,	90	L<Event>, L<Glib>, L<AnyEvent::Impl::Perl>, L<Tk>, L<Event::Lib>, L<Qt>,
85	L<POE>. The first one found is used. If none are found, the module tries	91	L<POE>. The first one found is used. If none are found, the module tries
86	to load these modules (excluding Tk, Event::Lib, Qt and POE as the pure perl	92	to load these modules (excluding Tk, Event::Lib, Qt and POE as the pure perl
87	adaptor should always succeed) in the order given. The first one that can	93	adaptor should always succeed) in the order given. The first one that can
88	be successfully loaded will be used. If, after this, still none could be	94	be successfully loaded will be used. If, after this, still none could be
…		…
102	starts using it, all bets are off. Maybe you should tell their authors to	108	starts using it, all bets are off. Maybe you should tell their authors to
103	use AnyEvent so their modules work together with others seamlessly...	109	use AnyEvent so their modules work together with others seamlessly...
104		110
105	The pure-perl implementation of AnyEvent is called	111	The pure-perl implementation of AnyEvent is called
106	C<AnyEvent::Impl::Perl>. Like other event modules you can load it	112	C<AnyEvent::Impl::Perl>. Like other event modules you can load it
107	explicitly.	113	explicitly and enjoy the high availability of that event loop :)
108		114
109	=head1 WATCHERS	115	=head1 WATCHERS
110		116
111	AnyEvent has the central concept of a I<watcher>, which is an object that	117	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	118	stores relevant data for each kind of event you are waiting for, such as
113	the callback to call, the filehandle to watch, etc.	119	the callback to call, the file handle to watch, etc.
114		120
115	These watchers are normal Perl objects with normal Perl lifetime. After	121	These watchers are normal Perl objects with normal Perl lifetime. After
116	creating a watcher it will immediately "watch" for events and invoke the	122	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	123	callback when the event occurs (of course, only when the event model
118	is in control).	124	is in control).
…		…
237		243
238	Although the callback might get passed parameters, their value and	244	Although the callback might get passed parameters, their value and
239	presence is undefined and you cannot rely on them. Portable AnyEvent	245	presence is undefined and you cannot rely on them. Portable AnyEvent
240	callbacks cannot use arguments passed to signal watcher callbacks.	246	callbacks cannot use arguments passed to signal watcher callbacks.
241		247
242	Multiple signal occurances can be clumped together into one callback	248	Multiple signal occurrences can be clumped together into one callback
243	invocation, and callback invocation will be synchronous. synchronous means	249	invocation, and callback invocation will be synchronous. Synchronous means
244	that it might take a while until the signal gets handled by the process,	250	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.	251	but it is guaranteed not to interrupt any other callbacks.
246		252
247	The main advantage of using these watchers is that you can share a signal	253	The main advantage of using these watchers is that you can share a signal
248	between multiple watchers.	254	between multiple watchers.
249		255
250	This watcher might use C<%SIG>, so programs overwriting those signals	256	This watcher might use C<%SIG>, so programs overwriting those signals
…		…
278	C<fork> the child (alternatively, you can call C<AnyEvent::detect>).	284	C<fork> the child (alternatively, you can call C<AnyEvent::detect>).
279		285
280	Example: fork a process and wait for it	286	Example: fork a process and wait for it
281		287
282	my $done = AnyEvent->condvar;	288	my $done = AnyEvent->condvar;
283
284	AnyEvent::detect; # force event module to be initialised
285		289
286	my $pid = fork or exit 5;	290	my $pid = fork or exit 5;
287		291
288	my $w = AnyEvent->child (	292	my $w = AnyEvent->child (
289	pid => $pid,	293	pid => $pid,
…		…
293	$done->send;	297	$done->send;
294	},	298	},
295	);	299	);
296		300
297	# do something else, then wait for process exit	301	# do something else, then wait for process exit
298	$done->wait;	302	$done->recv;
299		303
300	=head2 CONDITION VARIABLES	304	=head2 CONDITION VARIABLES
301		305
302	If you are familiar with some event loops you will know that all of them	306	If you are familiar with some event loops you will know that all of them
303	require you to run some blocking "loop", "run" or similar function that	307	require you to run some blocking "loop", "run" or similar function that
…		…
312	Condition variables can be created by calling the C<< AnyEvent->condvar	316	Condition variables can be created by calling the C<< AnyEvent->condvar
313	>> method, usually without arguments. The only argument pair allowed is	317	>> method, usually without arguments. The only argument pair allowed is
314	C<cb>, which specifies a callback to be called when the condition variable	318	C<cb>, which specifies a callback to be called when the condition variable
315	becomes true.	319	becomes true.
316		320
317	After creation, the conditon variable is "false" until it becomes "true"	321	After creation, the condition variable is "false" until it becomes "true"
318	by calling the C<send> method.	322	by calling the C<send> method (or calling the condition variable as if it
		323	were a callback, read about the caveats in the description for the C<<
		324	->send >> method).
319		325
320	Condition variables are similar to callbacks, except that you can	326	Condition variables are similar to callbacks, except that you can
321	optionally wait for them. They can also be called merge points - points	327	optionally wait for them. They can also be called merge points - points
322	in time where multiple outstandign events have been processed. And yet	328	in time where multiple outstanding events have been processed. And yet
323	another way to call them is transations - each condition variable can be	329	another way to call them is transactions - each condition variable can be
324	used to represent a transaction, which finishes at some point and delivers	330	used to represent a transaction, which finishes at some point and delivers
325	a result.	331	a result.
326		332
327	Condition variables are very useful to signal that something has finished,	333	Condition variables are very useful to signal that something has finished,
328	for example, if you write a module that does asynchronous http requests,	334	for example, if you write a module that does asynchronous http requests,
329	then a condition variable would be the ideal candidate to signal the	335	then a condition variable would be the ideal candidate to signal the
330	availability of results. The user can either act when the callback is	336	availability of results. The user can either act when the callback is
331	called or can synchronously C<< ->wait >> for the results.	337	called or can synchronously C<< ->recv >> for the results.
332		338
333	You can also use them to simulate traditional event loops - for example,	339	You can also use them to simulate traditional event loops - for example,
334	you can block your main program until an event occurs - for example, you	340	you can block your main program until an event occurs - for example, you
335	could C<< ->wait >> in your main program until the user clicks the Quit	341	could C<< ->recv >> in your main program until the user clicks the Quit
336	button of your app, which would C<< ->send >> the "quit" event.	342	button of your app, which would C<< ->send >> the "quit" event.
337		343
338	Note that condition variables recurse into the event loop - if you have	344	Note that condition variables recurse into the event loop - if you have
339	two pieces of code that call C<< ->wait >> in a round-robbin fashion, you	345	two pieces of code that call C<< ->recv >> in a round-robin fashion, you
340	lose. Therefore, condition variables are good to export to your caller, but	346	lose. Therefore, condition variables are good to export to your caller, but
341	you should avoid making a blocking wait yourself, at least in callbacks,	347	you should avoid making a blocking wait yourself, at least in callbacks,
342	as this asks for trouble.	348	as this asks for trouble.
343		349
344	Condition variables are represented by hash refs in perl, and the keys	350	Condition variables are represented by hash refs in perl, and the keys
…		…
349		355
350	There are two "sides" to a condition variable - the "producer side" which	356	There are two "sides" to a condition variable - the "producer side" which
351	eventually calls C<< -> send >>, and the "consumer side", which waits	357	eventually calls C<< -> send >>, and the "consumer side", which waits
352	for the send to occur.	358	for the send to occur.
353		359
354	Example:	360	Example: wait for a timer.
355		361
356	# wait till the result is ready	362	# wait till the result is ready
357	my $result_ready = AnyEvent->condvar;	363	my $result_ready = AnyEvent->condvar;
358		364
359	# do something such as adding a timer	365	# do something such as adding a timer
…		…
365	cb => sub { $result_ready->send },	371	cb => sub { $result_ready->send },
366	);	372	);
367		373
368	# this "blocks" (while handling events) till the callback	374	# this "blocks" (while handling events) till the callback
369	# calls send	375	# calls send
370	$result_ready->wait;	376	$result_ready->recv;
		377
		378	Example: wait for a timer, but take advantage of the fact that
		379	condition variables are also code references.
		380
		381	my $done = AnyEvent->condvar;
		382	my $delay = AnyEvent->timer (after => 5, cb => $done);
		383	$done->recv;
371		384
372	=head3 METHODS FOR PRODUCERS	385	=head3 METHODS FOR PRODUCERS
373		386
374	These methods should only be used by the producing side, i.e. the	387	These methods should only be used by the producing side, i.e. the
375	code/module that eventually sends the signal. Note that it is also	388	code/module that eventually sends the signal. Note that it is also
…		…
378		391
379	=over 4	392	=over 4
380		393
381	=item $cv->send (...)	394	=item $cv->send (...)
382		395
383	Flag the condition as ready - a running C<< ->wait >> and all further	396	Flag the condition as ready - a running C<< ->recv >> and all further
384	calls to C<wait> will (eventually) return after this method has been	397	calls to C<recv> will (eventually) return after this method has been
385	called. If nobody is waiting the send will be remembered.	398	called. If nobody is waiting the send will be remembered.
386		399
387	If a callback has been set on the condition variable, it is called	400	If a callback has been set on the condition variable, it is called
388	immediately from within send.	401	immediately from within send.
389		402
390	Any arguments passed to the C<send> call will be returned by all	403	Any arguments passed to the C<send> call will be returned by all
391	future C<< ->wait >> calls.	404	future C<< ->recv >> calls.
		405
		406	Condition variables are overloaded so one can call them directly
		407	(as a code reference). Calling them directly is the same as calling
		408	C<send>. Note, however, that many C-based event loops do not handle
		409	overloading, so as tempting as it may be, passing a condition variable
		410	instead of a callback does not work. Both the pure perl and EV loops
		411	support overloading, however, as well as all functions that use perl to
		412	invoke a callback (as in L<AnyEvent::Socket> and L<AnyEvent::DNS> for
		413	example).
392		414
393	=item $cv->croak ($error)	415	=item $cv->croak ($error)
394		416
395	Similar to send, but causes all call's wait C<< ->wait >> to invoke	417	Similar to send, but causes all call's to C<< ->recv >> to invoke
396	C<Carp::croak> with the given error message/object/scalar.	418	C<Carp::croak> with the given error message/object/scalar.
397		419
398	This can be used to signal any errors to the condition variable	420	This can be used to signal any errors to the condition variable
399	user/consumer.	421	user/consumer.
400		422
401	=item $cv->begin ([group callback])	423	=item $cv->begin ([group callback])
402		424
403	=item $cv->end	425	=item $cv->end
		426
		427	These two methods are EXPERIMENTAL and MIGHT CHANGE.
404		428
405	These two methods can be used to combine many transactions/events into	429	These two methods can be used to combine many transactions/events into
406	one. For example, a function that pings many hosts in parallel might want	430	one. For example, a function that pings many hosts in parallel might want
407	to use a condition variable for the whole process.	431	to use a condition variable for the whole process.
408		432
…		…
443	doesn't execute once).	467	doesn't execute once).
444		468
445	This is the general pattern when you "fan out" into multiple subrequests:	469	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>	470	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	471	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>.	472	C<begin> and for each subrequest you finish, call C<end>.
449		473
450	=back	474	=back
451		475
452	=head3 METHODS FOR CONSUMERS	476	=head3 METHODS FOR CONSUMERS
453		477
454	These methods should only be used by the consuming side, i.e. the	478	These methods should only be used by the consuming side, i.e. the
455	code awaits the condition.	479	code awaits the condition.
456		480
457	=over 4	481	=over 4
458		482
459	=item $cv->wait	483	=item $cv->recv
460		484
461	Wait (blocking if necessary) until the C<< ->send >> or C<< ->croak	485	Wait (blocking if necessary) until the C<< ->send >> or C<< ->croak
462	>> methods have been called on c<$cv>, while servicing other watchers	486	>> methods have been called on c<$cv>, while servicing other watchers
463	normally.	487	normally.
464		488
…		…
475	(programs might want to do that to stay interactive), so I<if you are	499	(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	500	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	501	caller decide whether the call will block or not (for example, by coupling
478	condition variables with some kind of request results and supporting	502	condition variables with some kind of request results and supporting
479	callbacks so the caller knows that getting the result will not block,	503	callbacks so the caller knows that getting the result will not block,
480	while still suppporting blocking waits if the caller so desires).	504	while still supporting blocking waits if the caller so desires).
481		505
482	Another reason I<never> to C<< ->wait >> in a module is that you cannot	506	Another reason I<never> to C<< ->recv >> in a module is that you cannot
483	sensibly have two C<< ->wait >>'s in parallel, as that would require	507	sensibly have two C<< ->recv >>'s in parallel, as that would require
484	multiple interpreters or coroutines/threads, none of which C<AnyEvent>	508	multiple interpreters or coroutines/threads, none of which C<AnyEvent>
485	can supply (the coroutine-aware backends L<AnyEvent::Impl::CoroEV> and	509	can supply.
486	L<AnyEvent::Impl::CoroEvent> explicitly support concurrent C<< ->wait >>'s
487	from different coroutines, however).
488		510
		511	The L<Coro> module, however, I<can> and I<does> supply coroutines and, in
		512	fact, L<Coro::AnyEvent> replaces AnyEvent's condvars by coroutine-safe
		513	versions and also integrates coroutines into AnyEvent, making blocking
		514	C<< ->recv >> calls perfectly safe as long as they are done from another
		515	coroutine (one that doesn't run the event loop).
		516
489	You can ensure that C<< -wait >> never blocks by setting a callback and	517	You can ensure that C<< -recv >> never blocks by setting a callback and
490	only calling C<< ->wait >> from within that callback (or at a later	518	only calling C<< ->recv >> from within that callback (or at a later
491	time). This will work even when the event loop does not support blocking	519	time). This will work even when the event loop does not support blocking
492	waits otherwise.	520	waits otherwise.
493		521
494	=item $bool = $cv->ready	522	=item $bool = $cv->ready
495		523
…		…
500		528
501	This is a mutator function that returns the callback set and optionally	529	This is a mutator function that returns the callback set and optionally
502	replaces it before doing so.	530	replaces it before doing so.
503		531
504	The callback will be called when the condition becomes "true", i.e. when	532	The callback will be called when the condition becomes "true", i.e. when
505	C<send> or C<croak> are called. Calling C<wait> inside the callback	533	C<send> or C<croak> are called. Calling C<recv> inside the callback
506	or at any later time is guaranteed not to block.	534	or at any later time is guaranteed not to block.
507		535
508	=back	536	=back
509		537
510	=head1 GLOBAL VARIABLES AND FUNCTIONS	538	=head1 GLOBAL VARIABLES AND FUNCTIONS
…		…
519	C<AnyEvent::Impl:xxx> modules, but can be any other class in the case	547	C<AnyEvent::Impl:xxx> modules, but can be any other class in the case
520	AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode>).	548	AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode>).
521		549
522	The known classes so far are:	550	The known classes so far are:
523		551
524	AnyEvent::Impl::CoroEV based on Coro::EV, best choice.
525	AnyEvent::Impl::CoroEvent based on Coro::Event, second best choice.
526	AnyEvent::Impl::EV based on EV (an interface to libev, best choice).	552	AnyEvent::Impl::EV based on EV (an interface to libev, best choice).
527	AnyEvent::Impl::Event based on Event, second best choice.	553	AnyEvent::Impl::Event based on Event, second best choice.
528	AnyEvent::Impl::Perl pure-perl implementation, fast and portable.	554	AnyEvent::Impl::Perl pure-perl implementation, fast and portable.
529	AnyEvent::Impl::Glib based on Glib, third-best choice.	555	AnyEvent::Impl::Glib based on Glib, third-best choice.
530	AnyEvent::Impl::Tk based on Tk, very bad choice.	556	AnyEvent::Impl::Tk based on Tk, very bad choice.
…		…
547	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model	573	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model
548	if necessary. You should only call this function right before you would	574	if necessary. You should only call this function right before you would
549	have created an AnyEvent watcher anyway, that is, as late as possible at	575	have created an AnyEvent watcher anyway, that is, as late as possible at
550	runtime.	576	runtime.
551		577
		578	=item $guard = AnyEvent::post_detect { BLOCK }
		579
		580	Arranges for the code block to be executed as soon as the event model is
		581	autodetected (or immediately if this has already happened).
		582
		583	If called in scalar or list context, then it creates and returns an object
		584	that automatically removes the callback again when it is destroyed. See
		585	L<Coro::BDB> for a case where this is useful.
		586
		587	=item @AnyEvent::post_detect
		588
		589	If there are any code references in this array (you can C<push> to it
		590	before or after loading AnyEvent), then they will called directly after
		591	the event loop has been chosen.
		592
		593	You should check C<$AnyEvent::MODEL> before adding to this array, though:
		594	if it contains a true value then the event loop has already been detected,
		595	and the array will be ignored.
		596
		597	Best use C<AnyEvent::post_detect { BLOCK }> instead.
		598
552	=back	599	=back
553		600
554	=head1 WHAT TO DO IN A MODULE	601	=head1 WHAT TO DO IN A MODULE
555		602
556	As a module author, you should C<use AnyEvent> and call AnyEvent methods	603	As a module author, you should C<use AnyEvent> and call AnyEvent methods
…		…
559	Be careful when you create watchers in the module body - AnyEvent will	606	Be careful when you create watchers in the module body - AnyEvent will
560	decide which event module to use as soon as the first method is called, so	607	decide which event module to use as soon as the first method is called, so
561	by calling AnyEvent in your module body you force the user of your module	608	by calling AnyEvent in your module body you force the user of your module
562	to load the event module first.	609	to load the event module first.
563		610
564	Never call C<< ->wait >> on a condition variable unless you I<know> that	611	Never call C<< ->recv >> on a condition variable unless you I<know> that
565	the C<< ->send >> method has been called on it already. This is	612	the C<< ->send >> method has been called on it already. This is
566	because it will stall the whole program, and the whole point of using	613	because it will stall the whole program, and the whole point of using
567	events is to stay interactive.	614	events is to stay interactive.
568		615
569	It is fine, however, to call C<< ->wait >> when the user of your module	616	It is fine, however, to call C<< ->recv >> when the user of your module
570	requests it (i.e. if you create a http request object ad have a method	617	requests it (i.e. if you create a http request object ad have a method
571	called C<results> that returns the results, it should call C<< ->wait >>	618	called C<results> that returns the results, it should call C<< ->recv >>
572	freely, as the user of your module knows what she is doing. always).	619	freely, as the user of your module knows what she is doing. always).
573		620
574	=head1 WHAT TO DO IN THE MAIN PROGRAM	621	=head1 WHAT TO DO IN THE MAIN PROGRAM
575		622
576	There will always be a single main program - the only place that should	623	There will always be a single main program - the only place that should
…		…
578		625
579	If it doesn't care, it can just "use AnyEvent" and use it itself, or not	626	If it doesn't care, it can just "use AnyEvent" and use it itself, or not
580	do anything special (it does not need to be event-based) and let AnyEvent	627	do anything special (it does not need to be event-based) and let AnyEvent
581	decide which implementation to chose if some module relies on it.	628	decide which implementation to chose if some module relies on it.
582		629
583	If the main program relies on a specific event model. For example, in	630	If the main program relies on a specific event model - for example, in
584	Gtk2 programs you have to rely on the Glib module. You should load the	631	Gtk2 programs you have to rely on the Glib module - you should load the
585	event module before loading AnyEvent or any module that uses it: generally	632	event module before loading AnyEvent or any module that uses it: generally
586	speaking, you should load it as early as possible. The reason is that	633	speaking, you should load it as early as possible. The reason is that
587	modules might create watchers when they are loaded, and AnyEvent will	634	modules might create watchers when they are loaded, and AnyEvent will
588	decide on the event model to use as soon as it creates watchers, and it	635	decide on the event model to use as soon as it creates watchers, and it
589	might chose the wrong one unless you load the correct one yourself.	636	might chose the wrong one unless you load the correct one yourself.
590		637
591	You can chose to use a rather inefficient pure-perl implementation by	638	You can chose to use a pure-perl implementation by loading the
592	loading the C<AnyEvent::Impl::Perl> module, which gives you similar	639	C<AnyEvent::Impl::Perl> module, which gives you similar behaviour
593	behaviour everywhere, but letting AnyEvent chose is generally better.	640	everywhere, but letting AnyEvent chose the model is generally better.
		641
		642	=head2 MAINLOOP EMULATION
		643
		644	Sometimes (often for short test scripts, or even standalone programs who
		645	only want to use AnyEvent), you do not want to run a specific event loop.
		646
		647	In that case, you can use a condition variable like this:
		648
		649	AnyEvent->condvar->recv;
		650
		651	This has the effect of entering the event loop and looping forever.
		652
		653	Note that usually your program has some exit condition, in which case
		654	it is better to use the "traditional" approach of storing a condition
		655	variable somewhere, waiting for it, and sending it when the program should
		656	exit cleanly.
		657
594		658
595	=head1 OTHER MODULES	659	=head1 OTHER MODULES
596		660
597	The following is a non-exhaustive list of additional modules that use	661	The following is a non-exhaustive list of additional modules that use
598	AnyEvent and can therefore be mixed easily with other AnyEvent modules	662	AnyEvent and can therefore be mixed easily with other AnyEvent modules
…		…
610		674
611	Provide read and write buffers and manages watchers for reads and writes.	675	Provide read and write buffers and manages watchers for reads and writes.
612		676
613	=item L<AnyEvent::Socket>	677	=item L<AnyEvent::Socket>
614		678
615	Provides a means to do non-blocking connects, accepts etc.	679	Provides various utility functions for (internet protocol) sockets,
		680	addresses and name resolution. Also functions to create non-blocking tcp
		681	connections or tcp servers, with IPv6 and SRV record support and more.
		682
		683	=item L<AnyEvent::DNS>
		684
		685	Provides rich asynchronous DNS resolver capabilities.
616		686
617	=item L<AnyEvent::HTTPD>	687	=item L<AnyEvent::HTTPD>
618		688
619	Provides a simple web application server framework.	689	Provides a simple web application server framework.
620
621	=item L<AnyEvent::DNS>
622
623	Provides asynchronous DNS resolver capabilities, beyond what
624	L<AnyEvent::Util> offers.
625		690
626	=item L<AnyEvent::FastPing>	691	=item L<AnyEvent::FastPing>
627		692
628	The fastest ping in the west.	693	The fastest ping in the west.
629		694
…		…
644		709
645	High level API for event-based execution flow control.	710	High level API for event-based execution flow control.
646		711
647	=item L<Coro>	712	=item L<Coro>
648		713
649	Has special support for AnyEvent.	714	Has special support for AnyEvent via L<Coro::AnyEvent>.
		715
		716	=item L<AnyEvent::AIO>, L<IO::AIO>
		717
		718	Truly asynchronous I/O, should be in the toolbox of every event
		719	programmer. AnyEvent::AIO transparently fuses IO::AIO and AnyEvent
		720	together.
		721
		722	=item L<AnyEvent::BDB>, L<BDB>
		723
		724	Truly asynchronous Berkeley DB access. AnyEvent::AIO transparently fuses
		725	IO::AIO and AnyEvent together.
650		726
651	=item L<IO::Lambda>	727	=item L<IO::Lambda>
652		728
653	The lambda approach to I/O - don't ask, look there. Can use AnyEvent.	729	The lambda approach to I/O - don't ask, look there. Can use AnyEvent.
654
655	=item L<IO::AIO>
656
657	Truly asynchronous I/O, should be in the toolbox of every event
658	programmer. Can be trivially made to use AnyEvent.
659
660	=item L<BDB>
661
662	Truly asynchronous Berkeley DB access. Can be trivially made to use
663	AnyEvent.
664		730
665	=back	731	=back
666		732
667	=cut	733	=cut
668		734
…		…
671	no warnings;	737	no warnings;
672	use strict;	738	use strict;
673		739
674	use Carp;	740	use Carp;
675		741
676	our $VERSION = '3.3';	742	our $VERSION = '4.05';
677	our $MODEL;	743	our $MODEL;
678		744
679	our $AUTOLOAD;	745	our $AUTOLOAD;
680	our @ISA;	746	our @ISA;
681		747
		748	our @REGISTRY;
		749
		750	our $WIN32;
		751
		752	BEGIN {
		753	my $win32 = ! ! ($^O =~ /mswin32/i);
		754	eval "sub WIN32(){ $win32 }";
		755	}
		756
682	our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1;	757	our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1;
683		758
684	our @REGISTRY;	759	our %PROTOCOL; # (ipv4\|ipv6) => (1\|2), higher numbers are preferred
		760
		761	{
		762	my $idx;
		763	$PROTOCOL{$_} = ++$idx
		764	for reverse split /\s,\s/,
		765	$ENV{PERL_ANYEVENT_PROTOCOLS} \|\| "ipv4,ipv6";
		766	}
685		767
686	my @models = (	768	my @models = (
687	[Coro::EV:: => AnyEvent::Impl::CoroEV::],
688	[Coro::Event:: => AnyEvent::Impl::CoroEvent::],
689	[EV:: => AnyEvent::Impl::EV::],	769	[EV:: => AnyEvent::Impl::EV::],
690	[Event:: => AnyEvent::Impl::Event::],	770	[Event:: => AnyEvent::Impl::Event::],
691	[Tk:: => AnyEvent::Impl::Tk::],
692	[Wx:: => AnyEvent::Impl::POE::],
693	[Prima:: => AnyEvent::Impl::POE::],
694	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::],	771	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::],
695	# everything below here will not be autoprobed as the pureperl backend should work everywhere	772	# everything below here will not be autoprobed
696	[Glib:: => AnyEvent::Impl::Glib::],	773	# as the pureperl backend should work everywhere
		774	# and is usually faster
		775	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
		776	[Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers
697	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy	777	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
698	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program	778	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program
699	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza	779	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
		780	[Wx:: => AnyEvent::Impl::POE::],
		781	[Prima:: => AnyEvent::Impl::POE::],
700	);	782	);
701		783
702	our %method = map +($_ => 1), qw(io timer signal child condvar one_event DESTROY);	784	our %method = map +($_ => 1), qw(io timer signal child condvar one_event DESTROY);
		785
		786	our @post_detect;
		787
		788	sub post_detect(&) {
		789	my ($cb) = @_;
		790
		791	if ($MODEL) {
		792	$cb->();
		793
		794	1
		795	} else {
		796	push @post_detect, $cb;
		797
		798	defined wantarray
		799	? bless \$cb, "AnyEvent::Util::PostDetect"
		800	: ()
		801	}
		802	}
		803
		804	sub AnyEvent::Util::PostDetect::DESTROY {
		805	@post_detect = grep $_ != ${$_[0]}, @post_detect;
		806	}
703		807
704	sub detect() {	808	sub detect() {
705	unless ($MODEL) {	809	unless ($MODEL) {
706	no strict 'refs';	810	no strict 'refs';
		811	local $SIG{__DIE__};
707		812
708	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {	813	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {
709	my $model = "AnyEvent::Impl::$1";	814	my $model = "AnyEvent::Impl::$1";
710	if (eval "require $model") {	815	if (eval "require $model") {
711	$MODEL = $model;	816	$MODEL = $model;
…		…
741	last;	846	last;
742	}	847	}
743	}	848	}
744		849
745	$MODEL	850	$MODEL
746	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.";	851	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.";
747	}	852	}
748	}	853	}
749		854
750	unshift @ISA, $MODEL;	855	unshift @ISA, $MODEL;
751	push @{"$MODEL\::ISA"}, "AnyEvent::Base";	856	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
		857
		858	(shift @post_detect)->() while @post_detect;
752	}	859	}
753		860
754	$MODEL	861	$MODEL
755	}	862	}
756		863
…		…
766	$class->$func (@_);	873	$class->$func (@_);
767	}	874	}
768		875
769	package AnyEvent::Base;	876	package AnyEvent::Base;
770		877
771	# default implementation for ->condvar, ->wait, ->broadcast	878	# default implementation for ->condvar
772		879
773	sub condvar {	880	sub condvar {
774	bless \my $flag, "AnyEvent::Base::CondVar"	881	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, AnyEvent::CondVar::
775	}
776
777	sub AnyEvent::Base::CondVar::broadcast {
778	${$_[0]}++;
779	}
780
781	sub AnyEvent::Base::CondVar::wait {
782	AnyEvent->one_event while !${$_[0]};
783	}	882	}
784		883
785	# default implementation for ->signal	884	# default implementation for ->signal
786		885
787	our %SIG_CB;	886	our %SIG_CB;
…		…
840	or Carp::croak "required option 'pid' is missing";	939	or Carp::croak "required option 'pid' is missing";
841		940
842	$PID_CB{$pid}{$arg{cb}} = $arg{cb};	941	$PID_CB{$pid}{$arg{cb}} = $arg{cb};
843		942
844	unless ($WNOHANG) {	943	unless ($WNOHANG) {
845	$WNOHANG = eval { require POSIX; &POSIX::WNOHANG } \|\| 1;	944	$WNOHANG = eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } \|\| 1;
846	}	945	}
847		946
848	unless ($CHLD_W) {	947	unless ($CHLD_W) {
849	$CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld);	948	$CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld);
850	# child could be a zombie already, so make at least one round	949	# child could be a zombie already, so make at least one round
…		…
860	delete $PID_CB{$pid}{$cb};	959	delete $PID_CB{$pid}{$cb};
861	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };	960	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };
862		961
863	undef $CHLD_W unless keys %PID_CB;	962	undef $CHLD_W unless keys %PID_CB;
864	}	963	}
		964
		965	package AnyEvent::CondVar;
		966
		967	our @ISA = AnyEvent::CondVar::Base::;
		968
		969	package AnyEvent::CondVar::Base;
		970
		971	use overload
		972	'&{}' => sub { my $self = shift; sub { $self->send (@_) } },
		973	fallback => 1;
		974
		975	sub _send {
		976	# nop
		977	}
		978
		979	sub send {
		980	my $cv = shift;
		981	$cv->{_ae_sent} = [@_];
		982	(delete $cv->{_ae_cb})->($cv) if $cv->{_ae_cb};
		983	$cv->_send;
		984	}
		985
		986	sub croak {
		987	$_[0]{_ae_croak} = $_[1];
		988	$_[0]->send;
		989	}
		990
		991	sub ready {
		992	$_[0]{_ae_sent}
		993	}
		994
		995	sub _wait {
		996	AnyEvent->one_event while !$_[0]{_ae_sent};
		997	}
		998
		999	sub recv {
		1000	$_[0]->_wait;
		1001
		1002	Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak};
		1003	wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0]
		1004	}
		1005
		1006	sub cb {
		1007	$_[0]{_ae_cb} = $_[1] if @_ > 1;
		1008	$_[0]{_ae_cb}
		1009	}
		1010
		1011	sub begin {
		1012	++$_[0]{_ae_counter};
		1013	$_[0]{_ae_end_cb} = $_[1] if @_ > 1;
		1014	}
		1015
		1016	sub end {
		1017	return if --$_[0]{_ae_counter};
		1018	&{ $_[0]{_ae_end_cb} \|\| sub { $_[0]->send } };
		1019	}
		1020
		1021	# undocumented/compatibility with pre-3.4
		1022	*broadcast = \&send;
		1023	*wait = \&_wait;
865		1024
866	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE	1025	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE
867		1026
868	This is an advanced topic that you do not normally need to use AnyEvent in	1027	This is an advanced topic that you do not normally need to use AnyEvent in
869	a module. This section is only of use to event loop authors who want to	1028	a module. This section is only of use to event loop authors who want to
…		…
926	model it chooses.	1085	model it chooses.
927		1086
928	=item C<PERL_ANYEVENT_MODEL>	1087	=item C<PERL_ANYEVENT_MODEL>
929		1088
930	This can be used to specify the event model to be used by AnyEvent, before	1089	This can be used to specify the event model to be used by AnyEvent, before
931	autodetection and -probing kicks in. It must be a string consisting	1090	auto detection and -probing kicks in. It must be a string consisting
932	entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended	1091	entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended
933	and the resulting module name is loaded and if the load was successful,	1092	and the resulting module name is loaded and if the load was successful,
934	used as event model. If it fails to load AnyEvent will proceed with	1093	used as event model. If it fails to load AnyEvent will proceed with
935	autodetection and -probing.	1094	auto detection and -probing.
936		1095
937	This functionality might change in future versions.	1096	This functionality might change in future versions.
938		1097
939	For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you	1098	For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you
940	could start your program like this:	1099	could start your program like this:
941		1100
942	PERL_ANYEVENT_MODEL=Perl perl ...	1101	PERL_ANYEVENT_MODEL=Perl perl ...
		1102
		1103	=item C<PERL_ANYEVENT_PROTOCOLS>
		1104
		1105	Used by both L<AnyEvent::DNS> and L<AnyEvent::Socket> to determine preferences
		1106	for IPv4 or IPv6. The default is unspecified (and might change, or be the result
		1107	of auto probing).
		1108
		1109	Must be set to a comma-separated list of protocols or address families,
		1110	current supported: C<ipv4> and C<ipv6>. Only protocols mentioned will be
		1111	used, and preference will be given to protocols mentioned earlier in the
		1112	list.
		1113
		1114	This variable can effectively be used for denial-of-service attacks
		1115	against local programs (e.g. when setuid), although the impact is likely
		1116	small, as the program has to handle connection errors already-
		1117
		1118	Examples: C<PERL_ANYEVENT_PROTOCOLS=ipv4,ipv6> - prefer IPv4 over IPv6,
		1119	but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4>
		1120	- only support IPv4, never try to resolve or contact IPv6
		1121	addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or
		1122	IPv6, but prefer IPv6 over IPv4.
		1123
		1124	=item C<PERL_ANYEVENT_EDNS0>
		1125
		1126	Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension
		1127	for DNS. This extension is generally useful to reduce DNS traffic, but
		1128	some (broken) firewalls drop such DNS packets, which is why it is off by
		1129	default.
		1130
		1131	Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce
		1132	EDNS0 in its DNS requests.
		1133
		1134	=item C<PERL_ANYEVENT_MAX_FORKS>
		1135
		1136	The maximum number of child processes that C<AnyEvent::Util::fork_call>
		1137	will create in parallel.
943		1138
944	=back	1139	=back
945		1140
946	=head1 EXAMPLE PROGRAM	1141	=head1 EXAMPLE PROGRAM
947		1142
…		…
958	poll => 'r',	1153	poll => 'r',
959	cb => sub {	1154	cb => sub {
960	warn "io event <$_[0]>\n"; # will always output <r>	1155	warn "io event <$_[0]>\n"; # will always output <r>
961	chomp (my $input = <STDIN>); # read a line	1156	chomp (my $input = <STDIN>); # read a line
962	warn "read: $input\n"; # output what has been read	1157	warn "read: $input\n"; # output what has been read
963	$cv->broadcast if $input =~ /^q/i; # quit program if /^q/i	1158	$cv->send if $input =~ /^q/i; # quit program if /^q/i
964	},	1159	},
965	);	1160	);
966		1161
967	my $time_watcher; # can only be used once	1162	my $time_watcher; # can only be used once
968		1163
…		…
973	});	1168	});
974	}	1169	}
975		1170
976	new_timer; # create first timer	1171	new_timer; # create first timer
977		1172
978	$cv->wait; # wait until user enters /^q/i	1173	$cv->recv; # wait until user enters /^q/i
979		1174
980	=head1 REAL-WORLD EXAMPLE	1175	=head1 REAL-WORLD EXAMPLE
981		1176
982	Consider the L<Net::FCP> module. It features (among others) the following	1177	Consider the L<Net::FCP> module. It features (among others) the following
983	API calls, which are to freenet what HTTP GET requests are to http:	1178	API calls, which are to freenet what HTTP GET requests are to http:
…		…
1033	syswrite $txn->{fh}, $txn->{request}	1228	syswrite $txn->{fh}, $txn->{request}
1034	or die "connection or write error";	1229	or die "connection or write error";
1035	$txn->{w} = AnyEvent->io (fh => $txn->{fh}, poll => 'r', cb => sub { $txn->fh_ready_r });	1230	$txn->{w} = AnyEvent->io (fh => $txn->{fh}, poll => 'r', cb => sub { $txn->fh_ready_r });
1036		1231
1037	Again, C<fh_ready_r> waits till all data has arrived, and then stores the	1232	Again, C<fh_ready_r> waits till all data has arrived, and then stores the
1038	result and signals any possible waiters that the request ahs finished:	1233	result and signals any possible waiters that the request has finished:
1039		1234
1040	sysread $txn->{fh}, $txn->{buf}, length $txn->{$buf};	1235	sysread $txn->{fh}, $txn->{buf}, length $txn->{$buf};
1041		1236
1042	if (end-of-file or data complete) {	1237	if (end-of-file or data complete) {
1043	$txn->{result} = $txn->{buf};	1238	$txn->{result} = $txn->{buf};
1044	$txn->{finished}->broadcast;	1239	$txn->{finished}->send;
1045	$txb->{cb}->($txn) of $txn->{cb}; # also call callback	1240	$txb->{cb}->($txn) of $txn->{cb}; # also call callback
1046	}	1241	}
1047		1242
1048	The C<result> method, finally, just waits for the finished signal (if the	1243	The C<result> method, finally, just waits for the finished signal (if the
1049	request was already finished, it doesn't wait, of course, and returns the	1244	request was already finished, it doesn't wait, of course, and returns the
1050	data:	1245	data:
1051		1246
1052	$txn->{finished}->wait;	1247	$txn->{finished}->recv;
1053	return $txn->{result};	1248	return $txn->{result};
1054		1249
1055	The actual code goes further and collects all errors (C<die>s, exceptions)	1250	The actual code goes further and collects all errors (C<die>s, exceptions)
1056	that occured during request processing. The C<result> method detects	1251	that occurred during request processing. The C<result> method detects
1057	whether an exception as thrown (it is stored inside the $txn object)	1252	whether an exception as thrown (it is stored inside the $txn object)
1058	and just throws the exception, which means connection errors and other	1253	and just throws the exception, which means connection errors and other
1059	problems get reported tot he code that tries to use the result, not in a	1254	problems get reported tot he code that tries to use the result, not in a
1060	random callback.	1255	random callback.
1061		1256
…		…
1092		1287
1093	my $quit = AnyEvent->condvar;	1288	my $quit = AnyEvent->condvar;
1094		1289
1095	$fcp->txn_client_get ($url)->cb (sub {	1290	$fcp->txn_client_get ($url)->cb (sub {
1096	...	1291	...
1097	$quit->broadcast;	1292	$quit->send;
1098	});	1293	});
1099		1294
1100	$quit->wait;	1295	$quit->recv;
1101		1296
1102		1297
1103	=head1 BENCHMARKS	1298	=head1 BENCHMARKS
1104		1299
1105	To give you an idea of the performance and overheads that AnyEvent adds	1300	To give you an idea of the performance and overheads that AnyEvent adds
…		…
1107	of various event loops I prepared some benchmarks.	1302	of various event loops I prepared some benchmarks.
1108		1303
1109	=head2 BENCHMARKING ANYEVENT OVERHEAD	1304	=head2 BENCHMARKING ANYEVENT OVERHEAD
1110		1305
1111	Here is a benchmark of various supported event models used natively and	1306	Here is a benchmark of various supported event models used natively and
1112	through anyevent. The benchmark creates a lot of timers (with a zero	1307	through AnyEvent. The benchmark creates a lot of timers (with a zero
1113	timeout) and I/O watchers (watching STDOUT, a pty, to become writable,	1308	timeout) and I/O watchers (watching STDOUT, a pty, to become writable,
1114	which it is), lets them fire exactly once and destroys them again.	1309	which it is), lets them fire exactly once and destroys them again.
1115		1310
1116	Source code for this benchmark is found as F<eg/bench> in the AnyEvent	1311	Source code for this benchmark is found as F<eg/bench> in the AnyEvent
1117	distribution.	1312	distribution.
…		…
1134	all watchers, to avoid adding memory overhead. That means closure creation	1329	all watchers, to avoid adding memory overhead. That means closure creation
1135	and memory usage is not included in the figures.	1330	and memory usage is not included in the figures.
1136		1331
1137	I<invoke> is the time, in microseconds, used to invoke a simple	1332	I<invoke> is the time, in microseconds, used to invoke a simple
1138	callback. The callback simply counts down a Perl variable and after it was	1333	callback. The callback simply counts down a Perl variable and after it was
1139	invoked "watcher" times, it would C<< ->broadcast >> a condvar once to	1334	invoked "watcher" times, it would C<< ->send >> a condvar once to
1140	signal the end of this phase.	1335	signal the end of this phase.
1141		1336
1142	I<destroy> is the time, in microseconds, that it takes to destroy a single	1337	I<destroy> is the time, in microseconds, that it takes to destroy a single
1143	watcher.	1338	watcher.
1144		1339
…		…
1240		1435
1241	=back	1436	=back
1242		1437
1243	=head2 BENCHMARKING THE LARGE SERVER CASE	1438	=head2 BENCHMARKING THE LARGE SERVER CASE
1244		1439
1245	This benchmark atcually benchmarks the event loop itself. It works by	1440	This benchmark actually benchmarks the event loop itself. It works by
1246	creating a number of "servers": each server consists of a socketpair, a	1441	creating a number of "servers": each server consists of a socket pair, a
1247	timeout watcher that gets reset on activity (but never fires), and an I/O	1442	timeout watcher that gets reset on activity (but never fires), and an I/O
1248	watcher waiting for input on one side of the socket. Each time the socket	1443	watcher waiting for input on one side of the socket. Each time the socket
1249	watcher reads a byte it will write that byte to a random other "server".	1444	watcher reads a byte it will write that byte to a random other "server".
1250		1445
1251	The effect is that there will be a lot of I/O watchers, only part of which	1446	The effect is that there will be a lot of I/O watchers, only part of which
1252	are active at any one point (so there is a constant number of active	1447	are active at any one point (so there is a constant number of active
1253	fds for each loop iterstaion, but which fds these are is random). The	1448	fds for each loop iteration, but which fds these are is random). The
1254	timeout is reset each time something is read because that reflects how	1449	timeout is reset each time something is read because that reflects how
1255	most timeouts work (and puts extra pressure on the event loops).	1450	most timeouts work (and puts extra pressure on the event loops).
1256		1451
1257	In this benchmark, we use 10000 socketpairs (20000 sockets), of which 100	1452	In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100
1258	(1%) are active. This mirrors the activity of large servers with many	1453	(1%) are active. This mirrors the activity of large servers with many
1259	connections, most of which are idle at any one point in time.	1454	connections, most of which are idle at any one point in time.
1260		1455
1261	Source code for this benchmark is found as F<eg/bench2> in the AnyEvent	1456	Source code for this benchmark is found as F<eg/bench2> in the AnyEvent
1262	distribution.	1457	distribution.
…		…
1264	=head3 Explanation of the columns	1459	=head3 Explanation of the columns
1265		1460
1266	I<sockets> is the number of sockets, and twice the number of "servers" (as	1461	I<sockets> is the number of sockets, and twice the number of "servers" (as
1267	each server has a read and write socket end).	1462	each server has a read and write socket end).
1268		1463
1269	I<create> is the time it takes to create a socketpair (which is	1464	I<create> is the time it takes to create a socket pair (which is
1270	nontrivial) and two watchers: an I/O watcher and a timeout watcher.	1465	nontrivial) and two watchers: an I/O watcher and a timeout watcher.
1271		1466
1272	I<request>, the most important value, is the time it takes to handle a	1467	I<request>, the most important value, is the time it takes to handle a
1273	single "request", that is, reading the token from the pipe and forwarding	1468	single "request", that is, reading the token from the pipe and forwarding
1274	it to another server. This includes deleting the old timeout and creating	1469	it to another server. This includes deleting the old timeout and creating
…		…
1347	speed most when you have lots of watchers, not when you only have a few of	1542	speed most when you have lots of watchers, not when you only have a few of
1348	them).	1543	them).
1349		1544
1350	EV is again fastest.	1545	EV is again fastest.
1351		1546
1352	Perl again comes second. It is noticably faster than the C-based event	1547	Perl again comes second. It is noticeably faster than the C-based event
1353	loops Event and Glib, although the difference is too small to really	1548	loops Event and Glib, although the difference is too small to really
1354	matter.	1549	matter.
1355		1550
1356	POE also performs much better in this case, but is is still far behind the	1551	POE also performs much better in this case, but is is still far behind the
1357	others.	1552	others.
…		…
1397	probably even less useful to an attacker than PERL_ANYEVENT_MODEL).	1592	probably even less useful to an attacker than PERL_ANYEVENT_MODEL).
1398		1593
1399		1594
1400	=head1 SEE ALSO	1595	=head1 SEE ALSO
1401		1596
1402	Event modules: L<Coro::EV>, L<EV>, L<EV::Glib>, L<Glib::EV>,	1597	Utility functions: L<AnyEvent::Util>.
1403	L<Coro::Event>, L<Event>, L<Glib::Event>, L<Glib>, L<Coro>, L<Tk>,	1598
		1599	Event modules: L<EV>, L<EV::Glib>, L<Glib::EV>, L<Event>, L<Glib::Event>,
1404	L<Event::Lib>, L<Qt>, L<POE>.	1600	L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.
1405		1601
1406	Implementations: L<AnyEvent::Impl::CoroEV>, L<AnyEvent::Impl::EV>,	1602	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,
1407	L<AnyEvent::Impl::CoroEvent>, L<AnyEvent::Impl::Event>, L<AnyEvent::Impl::Glib>,	1603	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,
1408	L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>, L<AnyEvent::Impl::EventLib>,	1604	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,
1409	L<AnyEvent::Impl::Qt>, L<AnyEvent::Impl::POE>.	1605	L<AnyEvent::Impl::POE>.
1410		1606
		1607	Non-blocking file handles, sockets, TCP clients and
		1608	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>.
		1609
		1610	Asynchronous DNS: L<AnyEvent::DNS>.
		1611
		1612	Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>,
		1613
1411	Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>.	1614	Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>, L<AnyEvent::DNS>.
1412		1615
1413		1616
1414	=head1 AUTHOR	1617	=head1 AUTHOR
1415		1618
1416	Marc Lehmann <schmorp@schmorp.de>	1619	Marc Lehmann <schmorp@schmorp.de>

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Comparing AnyEvent/lib/AnyEvent.pm (file contents): Revision 1.107 by root, Tue May 6 12:15:50 2008 UTC vs. Revision 1.142 by root, Tue May 27 02:34:30 2008 UTC

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Comparing AnyEvent/lib/AnyEvent.pm (file contents):
Revision 1.107 by root, Tue May 6 12:15:50 2008 UTC vs.
Revision 1.142 by root, Tue May 27 02:34:30 2008 UTC