[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 1.148 by root, Sat May 31 00:40:16 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
		23	=head1 INTRODUCTION/TUTORIAL
		24
		25	This manpage is mainly a reference manual. If you are interested
		26	in a tutorial or some gentle introduction, have a look at the
		27	L<AnyEvent::Intro> manpage.
22		28
23	=head1 WHY YOU SHOULD USE THIS MODULE (OR NOT)	29	=head1 WHY YOU SHOULD USE THIS MODULE (OR NOT)
24		30
25	Glib, POE, IO::Async, Event... CPAN offers event models by the dozen	31	Glib, POE, IO::Async, Event... CPAN offers event models by the dozen
26	nowadays. So what is different about AnyEvent?	32	nowadays. So what is different about AnyEvent?
…		…
48	isn't itself. What's worse, all the potential users of your module are	54	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.	55	I<also> forced to use the same event loop you use.
50		56
51	AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works	57	AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works
52	fine. AnyEvent + Tk works fine etc. etc. but none of these work together	58	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	59	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,	60	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	61	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	62	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	63	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).	64	event loops to AnyEvent, too, so it is future-proof).
59		65
60	In addition to being free of having to use I<the one and only true event	66	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	67	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	68	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	69	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	70	offering the functionality that is necessary, in as thin as a wrapper as
65	technically possible.	71	technically possible.
66		72
		73	Of course, AnyEvent comes with a big (and fully optional!) toolbox
		74	of useful functionality, such as an asynchronous DNS resolver, 100%
		75	non-blocking connects (even with TLS/SSL, IPv6 and on broken platforms
		76	such as Windows) and lots of real-world knowledge and workarounds for
		77	platform bugs and differences.
		78
67	Of course, if you want lots of policy (this can arguably be somewhat	79	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	80	useful) and you want to force your users to use the one and only event
69	model, you should I<not> use this module.	81	model, you should I<not> use this module.
70		82
71	=head1 DESCRIPTION	83	=head1 DESCRIPTION
72		84
…		…
78	The interface itself is vaguely similar, but not identical to the L<Event>	90	The interface itself is vaguely similar, but not identical to the L<Event>
79	module.	91	module.
80		92
81	During the first call of any watcher-creation method, the module tries	93	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	94	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>,	95	following modules is already loaded: L<EV>,
84	L<Event>, L<Glib>, L<AnyEvent::Impl::Perl>, L<Tk>, L<Event::Lib>, L<Qt>,	96	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	97	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	98	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	99	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	100	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	114	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...	115	use AnyEvent so their modules work together with others seamlessly...
104		116
105	The pure-perl implementation of AnyEvent is called	117	The pure-perl implementation of AnyEvent is called
106	C<AnyEvent::Impl::Perl>. Like other event modules you can load it	118	C<AnyEvent::Impl::Perl>. Like other event modules you can load it
107	explicitly.	119	explicitly and enjoy the high availability of that event loop :)
108		120
109	=head1 WATCHERS	121	=head1 WATCHERS
110		122
111	AnyEvent has the central concept of a I<watcher>, which is an object that	123	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	124	stores relevant data for each kind of event you are waiting for, such as
113	the callback to call, the filehandle to watch, etc.	125	the callback to call, the file handle to watch, etc.
114		126
115	These watchers are normal Perl objects with normal Perl lifetime. After	127	These watchers are normal Perl objects with normal Perl lifetime. After
116	creating a watcher it will immediately "watch" for events and invoke the	128	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	129	callback when the event occurs (of course, only when the event model
118	is in control).	130	is in control).
…		…
227	timers.	239	timers.
228		240
229	AnyEvent always prefers relative timers, if available, matching the	241	AnyEvent always prefers relative timers, if available, matching the
230	AnyEvent API.	242	AnyEvent API.
231		243
		244	AnyEvent has two additional methods that return the "current time":
		245
		246	=over 4
		247
		248	=item AnyEvent->time
		249
		250	This returns the "current wallclock time" as a fractional number of
		251	seconds since the Epoch (the same thing as C<time> or C<Time::HiRes::time>
		252	return, and the result is guaranteed to be compatible with those).
		253
		254	It progresses independently of any event loop processing, i.e. each call
		255	will check the system clock, which usually gets updated frequently.
		256
		257	=item AnyEvent->now
		258
		259	This also returns the "current wallclock time", but unlike C<time>, above,
		260	this value might change only once per event loop iteration, depending on
		261	the event loop (most return the same time as C<time>, above). This is the
		262	time that AnyEvent's timers get scheduled against.
		263
		264	I<In almost all cases (in all cases if you don't care), this is the
		265	function to call when you want to know the current time.>
		266
		267	This function is also often faster then C<< AnyEvent->time >>, and
		268	thus the preferred method if you want some timestamp (for example,
		269	L<AnyEvent::Handle> uses this to update it's activity timeouts).
		270
		271	The rest of this section is only of relevance if you try to be very exact
		272	with your timing, you can skip it without bad conscience.
		273
		274	For a practical example of when these times differ, consider L<Event::Lib>
		275	and L<EV> and the following set-up:
		276
		277	The event loop is running and has just invoked one of your callback at
		278	time=500 (assume no other callbacks delay processing). In your callback,
		279	you wait a second by executing C<sleep 1> (blocking the process for a
		280	second) and then (at time=501) you create a relative timer that fires
		281	after three seconds.
		282
		283	With L<Event::Lib>, C<< AnyEvent->time >> and C<< AnyEvent->now >> will
		284	both return C<501>, because that is the current time, and the timer will
		285	be scheduled to fire at time=504 (C<501> + C<3>).
		286
		287	With L<EV>, C<< AnyEvent->time >> returns C<501> (as that is the current
		288	time), but C<< AnyEvent->now >> returns C<500>, as that is the time the
		289	last event processing phase started. With L<EV>, your timer gets scheduled
		290	to run at time=503 (C<500> + C<3>).
		291
		292	In one sense, L<Event::Lib> is more exact, as it uses the current time
		293	regardless of any delays introduced by event processing. However, most
		294	callbacks do not expect large delays in processing, so this causes a
		295	higher drift (and a lot more system calls to get the current time).
		296
		297	In another sense, L<EV> is more exact, as your timer will be scheduled at
		298	the same time, regardless of how long event processing actually took.
		299
		300	In either case, if you care (and in most cases, you don't), then you
		301	can get whatever behaviour you want with any event loop, by taking the
		302	difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into
		303	account.
		304
		305	=back
		306
232	=head2 SIGNAL WATCHERS	307	=head2 SIGNAL WATCHERS
233		308
234	You can watch for signals using a signal watcher, C<signal> is the signal	309	You can watch for signals using a signal watcher, C<signal> is the signal
235	I<name> without any C<SIG> prefix, C<cb> is the Perl callback to	310	I<name> without any C<SIG> prefix, C<cb> is the Perl callback to
236	be invoked whenever a signal occurs.	311	be invoked whenever a signal occurs.
237		312
238	Although the callback might get passed parameters, their value and	313	Although the callback might get passed parameters, their value and
239	presence is undefined and you cannot rely on them. Portable AnyEvent	314	presence is undefined and you cannot rely on them. Portable AnyEvent
240	callbacks cannot use arguments passed to signal watcher callbacks.	315	callbacks cannot use arguments passed to signal watcher callbacks.
241		316
242	Multiple signal occurances can be clumped together into one callback	317	Multiple signal occurrences can be clumped together into one callback
243	invocation, and callback invocation will be synchronous. synchronous means	318	invocation, and callback invocation will be synchronous. Synchronous means
244	that it might take a while until the signal gets handled by the process,	319	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.	320	but it is guaranteed not to interrupt any other callbacks.
246		321
247	The main advantage of using these watchers is that you can share a signal	322	The main advantage of using these watchers is that you can share a signal
248	between multiple watchers.	323	between multiple watchers.
249		324
250	This watcher might use C<%SIG>, so programs overwriting those signals	325	This watcher might use C<%SIG>, so programs overwriting those signals
…		…
278	C<fork> the child (alternatively, you can call C<AnyEvent::detect>).	353	C<fork> the child (alternatively, you can call C<AnyEvent::detect>).
279		354
280	Example: fork a process and wait for it	355	Example: fork a process and wait for it
281		356
282	my $done = AnyEvent->condvar;	357	my $done = AnyEvent->condvar;
283
284	AnyEvent::detect; # force event module to be initialised
285		358
286	my $pid = fork or exit 5;	359	my $pid = fork or exit 5;
287		360
288	my $w = AnyEvent->child (	361	my $w = AnyEvent->child (
289	pid => $pid,	362	pid => $pid,
…		…
293	$done->send;	366	$done->send;
294	},	367	},
295	);	368	);
296		369
297	# do something else, then wait for process exit	370	# do something else, then wait for process exit
298	$done->wait;	371	$done->recv;
299		372
300	=head2 CONDITION VARIABLES	373	=head2 CONDITION VARIABLES
301		374
302	If you are familiar with some event loops you will know that all of them	375	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	376	require you to run some blocking "loop", "run" or similar function that
…		…
312	Condition variables can be created by calling the C<< AnyEvent->condvar	385	Condition variables can be created by calling the C<< AnyEvent->condvar
313	>> method, usually without arguments. The only argument pair allowed is	386	>> method, usually without arguments. The only argument pair allowed is
314	C<cb>, which specifies a callback to be called when the condition variable	387	C<cb>, which specifies a callback to be called when the condition variable
315	becomes true.	388	becomes true.
316		389
317	After creation, the conditon variable is "false" until it becomes "true"	390	After creation, the condition variable is "false" until it becomes "true"
318	by calling the C<send> method.	391	by calling the C<send> method (or calling the condition variable as if it
		392	were a callback, read about the caveats in the description for the C<<
		393	->send >> method).
319		394
320	Condition variables are similar to callbacks, except that you can	395	Condition variables are similar to callbacks, except that you can
321	optionally wait for them. They can also be called merge points - points	396	optionally wait for them. They can also be called merge points - points
322	in time where multiple outstandign events have been processed. And yet	397	in time where multiple outstanding events have been processed. And yet
323	another way to call them is transations - each condition variable can be	398	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	399	used to represent a transaction, which finishes at some point and delivers
325	a result.	400	a result.
326		401
327	Condition variables are very useful to signal that something has finished,	402	Condition variables are very useful to signal that something has finished,
328	for example, if you write a module that does asynchronous http requests,	403	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	404	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	405	availability of results. The user can either act when the callback is
331	called or can synchronously C<< ->wait >> for the results.	406	called or can synchronously C<< ->recv >> for the results.
332		407
333	You can also use them to simulate traditional event loops - for example,	408	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	409	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	410	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.	411	button of your app, which would C<< ->send >> the "quit" event.
337		412
338	Note that condition variables recurse into the event loop - if you have	413	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	414	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	415	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,	416	you should avoid making a blocking wait yourself, at least in callbacks,
342	as this asks for trouble.	417	as this asks for trouble.
343		418
344	Condition variables are represented by hash refs in perl, and the keys	419	Condition variables are represented by hash refs in perl, and the keys
…		…
349		424
350	There are two "sides" to a condition variable - the "producer side" which	425	There are two "sides" to a condition variable - the "producer side" which
351	eventually calls C<< -> send >>, and the "consumer side", which waits	426	eventually calls C<< -> send >>, and the "consumer side", which waits
352	for the send to occur.	427	for the send to occur.
353		428
354	Example:	429	Example: wait for a timer.
355		430
356	# wait till the result is ready	431	# wait till the result is ready
357	my $result_ready = AnyEvent->condvar;	432	my $result_ready = AnyEvent->condvar;
358		433
359	# do something such as adding a timer	434	# do something such as adding a timer
…		…
365	cb => sub { $result_ready->send },	440	cb => sub { $result_ready->send },
366	);	441	);
367		442
368	# this "blocks" (while handling events) till the callback	443	# this "blocks" (while handling events) till the callback
369	# calls send	444	# calls send
370	$result_ready->wait;	445	$result_ready->recv;
		446
		447	Example: wait for a timer, but take advantage of the fact that
		448	condition variables are also code references.
		449
		450	my $done = AnyEvent->condvar;
		451	my $delay = AnyEvent->timer (after => 5, cb => $done);
		452	$done->recv;
371		453
372	=head3 METHODS FOR PRODUCERS	454	=head3 METHODS FOR PRODUCERS
373		455
374	These methods should only be used by the producing side, i.e. the	456	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	457	code/module that eventually sends the signal. Note that it is also
…		…
378		460
379	=over 4	461	=over 4
380		462
381	=item $cv->send (...)	463	=item $cv->send (...)
382		464
383	Flag the condition as ready - a running C<< ->wait >> and all further	465	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	466	calls to C<recv> will (eventually) return after this method has been
385	called. If nobody is waiting the send will be remembered.	467	called. If nobody is waiting the send will be remembered.
386		468
387	If a callback has been set on the condition variable, it is called	469	If a callback has been set on the condition variable, it is called
388	immediately from within send.	470	immediately from within send.
389		471
390	Any arguments passed to the C<send> call will be returned by all	472	Any arguments passed to the C<send> call will be returned by all
391	future C<< ->wait >> calls.	473	future C<< ->recv >> calls.
		474
		475	Condition variables are overloaded so one can call them directly
		476	(as a code reference). Calling them directly is the same as calling
		477	C<send>. Note, however, that many C-based event loops do not handle
		478	overloading, so as tempting as it may be, passing a condition variable
		479	instead of a callback does not work. Both the pure perl and EV loops
		480	support overloading, however, as well as all functions that use perl to
		481	invoke a callback (as in L<AnyEvent::Socket> and L<AnyEvent::DNS> for
		482	example).
392		483
393	=item $cv->croak ($error)	484	=item $cv->croak ($error)
394		485
395	Similar to send, but causes all call's wait C<< ->wait >> to invoke	486	Similar to send, but causes all call's to C<< ->recv >> to invoke
396	C<Carp::croak> with the given error message/object/scalar.	487	C<Carp::croak> with the given error message/object/scalar.
397		488
398	This can be used to signal any errors to the condition variable	489	This can be used to signal any errors to the condition variable
399	user/consumer.	490	user/consumer.
400		491
401	=item $cv->begin ([group callback])	492	=item $cv->begin ([group callback])
402		493
403	=item $cv->end	494	=item $cv->end
		495
		496	These two methods are EXPERIMENTAL and MIGHT CHANGE.
404		497
405	These two methods can be used to combine many transactions/events into	498	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	499	one. For example, a function that pings many hosts in parallel might want
407	to use a condition variable for the whole process.	500	to use a condition variable for the whole process.
408		501
…		…
443	doesn't execute once).	536	doesn't execute once).
444		537
445	This is the general pattern when you "fan out" into multiple subrequests:	538	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>	539	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	540	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>.	541	C<begin> and for each subrequest you finish, call C<end>.
449		542
450	=back	543	=back
451		544
452	=head3 METHODS FOR CONSUMERS	545	=head3 METHODS FOR CONSUMERS
453		546
454	These methods should only be used by the consuming side, i.e. the	547	These methods should only be used by the consuming side, i.e. the
455	code awaits the condition.	548	code awaits the condition.
456		549
457	=over 4	550	=over 4
458		551
459	=item $cv->wait	552	=item $cv->recv
460		553
461	Wait (blocking if necessary) until the C<< ->send >> or C<< ->croak	554	Wait (blocking if necessary) until the C<< ->send >> or C<< ->croak
462	>> methods have been called on c<$cv>, while servicing other watchers	555	>> methods have been called on c<$cv>, while servicing other watchers
463	normally.	556	normally.
464		557
…		…
475	(programs might want to do that to stay interactive), so I<if you are	568	(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	569	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	570	caller decide whether the call will block or not (for example, by coupling
478	condition variables with some kind of request results and supporting	571	condition variables with some kind of request results and supporting
479	callbacks so the caller knows that getting the result will not block,	572	callbacks so the caller knows that getting the result will not block,
480	while still suppporting blocking waits if the caller so desires).	573	while still supporting blocking waits if the caller so desires).
481		574
482	Another reason I<never> to C<< ->wait >> in a module is that you cannot	575	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	576	sensibly have two C<< ->recv >>'s in parallel, as that would require
484	multiple interpreters or coroutines/threads, none of which C<AnyEvent>	577	multiple interpreters or coroutines/threads, none of which C<AnyEvent>
485	can supply (the coroutine-aware backends L<AnyEvent::Impl::CoroEV> and	578	can supply.
486	L<AnyEvent::Impl::CoroEvent> explicitly support concurrent C<< ->wait >>'s
487	from different coroutines, however).
488		579
		580	The L<Coro> module, however, I<can> and I<does> supply coroutines and, in
		581	fact, L<Coro::AnyEvent> replaces AnyEvent's condvars by coroutine-safe
		582	versions and also integrates coroutines into AnyEvent, making blocking
		583	C<< ->recv >> calls perfectly safe as long as they are done from another
		584	coroutine (one that doesn't run the event loop).
		585
489	You can ensure that C<< -wait >> never blocks by setting a callback and	586	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	587	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	588	time). This will work even when the event loop does not support blocking
492	waits otherwise.	589	waits otherwise.
493		590
494	=item $bool = $cv->ready	591	=item $bool = $cv->ready
495		592
…		…
500		597
501	This is a mutator function that returns the callback set and optionally	598	This is a mutator function that returns the callback set and optionally
502	replaces it before doing so.	599	replaces it before doing so.
503		600
504	The callback will be called when the condition becomes "true", i.e. when	601	The callback will be called when the condition becomes "true", i.e. when
505	C<send> or C<croak> are called. Calling C<wait> inside the callback	602	C<send> or C<croak> are called. Calling C<recv> inside the callback
506	or at any later time is guaranteed not to block.	603	or at any later time is guaranteed not to block.
507		604
508	=back	605	=back
509		606
510	=head1 GLOBAL VARIABLES AND FUNCTIONS	607	=head1 GLOBAL VARIABLES AND FUNCTIONS
…		…
519	C<AnyEvent::Impl:xxx> modules, but can be any other class in the case	616	C<AnyEvent::Impl:xxx> modules, but can be any other class in the case
520	AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode>).	617	AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode>).
521		618
522	The known classes so far are:	619	The known classes so far are:
523		620
524	AnyEvent::Impl::CoroEV based on Coro::EV, best choice.
525	AnyEvent::Impl::CoroEvent based on Coro::Event, second best choice.
526	AnyEvent::Impl::EV based on EV (an interface to libev, best choice).	621	AnyEvent::Impl::EV based on EV (an interface to libev, best choice).
527	AnyEvent::Impl::Event based on Event, second best choice.	622	AnyEvent::Impl::Event based on Event, second best choice.
528	AnyEvent::Impl::Perl pure-perl implementation, fast and portable.	623	AnyEvent::Impl::Perl pure-perl implementation, fast and portable.
529	AnyEvent::Impl::Glib based on Glib, third-best choice.	624	AnyEvent::Impl::Glib based on Glib, third-best choice.
530	AnyEvent::Impl::Tk based on Tk, very bad choice.	625	AnyEvent::Impl::Tk based on Tk, very bad choice.
…		…
547	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model	642	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model
548	if necessary. You should only call this function right before you would	643	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	644	have created an AnyEvent watcher anyway, that is, as late as possible at
550	runtime.	645	runtime.
551		646
		647	=item $guard = AnyEvent::post_detect { BLOCK }
		648
		649	Arranges for the code block to be executed as soon as the event model is
		650	autodetected (or immediately if this has already happened).
		651
		652	If called in scalar or list context, then it creates and returns an object
		653	that automatically removes the callback again when it is destroyed. See
		654	L<Coro::BDB> for a case where this is useful.
		655
		656	=item @AnyEvent::post_detect
		657
		658	If there are any code references in this array (you can C<push> to it
		659	before or after loading AnyEvent), then they will called directly after
		660	the event loop has been chosen.
		661
		662	You should check C<$AnyEvent::MODEL> before adding to this array, though:
		663	if it contains a true value then the event loop has already been detected,
		664	and the array will be ignored.
		665
		666	Best use C<AnyEvent::post_detect { BLOCK }> instead.
		667
552	=back	668	=back
553		669
554	=head1 WHAT TO DO IN A MODULE	670	=head1 WHAT TO DO IN A MODULE
555		671
556	As a module author, you should C<use AnyEvent> and call AnyEvent methods	672	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	675	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	676	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	677	by calling AnyEvent in your module body you force the user of your module
562	to load the event module first.	678	to load the event module first.
563		679
564	Never call C<< ->wait >> on a condition variable unless you I<know> that	680	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	681	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	682	because it will stall the whole program, and the whole point of using
567	events is to stay interactive.	683	events is to stay interactive.
568		684
569	It is fine, however, to call C<< ->wait >> when the user of your module	685	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	686	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 >>	687	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).	688	freely, as the user of your module knows what she is doing. always).
573		689
574	=head1 WHAT TO DO IN THE MAIN PROGRAM	690	=head1 WHAT TO DO IN THE MAIN PROGRAM
575		691
576	There will always be a single main program - the only place that should	692	There will always be a single main program - the only place that should
…		…
578		694
579	If it doesn't care, it can just "use AnyEvent" and use it itself, or not	695	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	696	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.	697	decide which implementation to chose if some module relies on it.
582		698
583	If the main program relies on a specific event model. For example, in	699	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	700	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	701	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	702	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	703	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	704	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.	705	might chose the wrong one unless you load the correct one yourself.
590		706
591	You can chose to use a rather inefficient pure-perl implementation by	707	You can chose to use a pure-perl implementation by loading the
592	loading the C<AnyEvent::Impl::Perl> module, which gives you similar	708	C<AnyEvent::Impl::Perl> module, which gives you similar behaviour
593	behaviour everywhere, but letting AnyEvent chose is generally better.	709	everywhere, but letting AnyEvent chose the model is generally better.
		710
		711	=head2 MAINLOOP EMULATION
		712
		713	Sometimes (often for short test scripts, or even standalone programs who
		714	only want to use AnyEvent), you do not want to run a specific event loop.
		715
		716	In that case, you can use a condition variable like this:
		717
		718	AnyEvent->condvar->recv;
		719
		720	This has the effect of entering the event loop and looping forever.
		721
		722	Note that usually your program has some exit condition, in which case
		723	it is better to use the "traditional" approach of storing a condition
		724	variable somewhere, waiting for it, and sending it when the program should
		725	exit cleanly.
		726
594		727
595	=head1 OTHER MODULES	728	=head1 OTHER MODULES
596		729
597	The following is a non-exhaustive list of additional modules that use	730	The following is a non-exhaustive list of additional modules that use
598	AnyEvent and can therefore be mixed easily with other AnyEvent modules	731	AnyEvent and can therefore be mixed easily with other AnyEvent modules
…		…
610		743
611	Provide read and write buffers and manages watchers for reads and writes.	744	Provide read and write buffers and manages watchers for reads and writes.
612		745
613	=item L<AnyEvent::Socket>	746	=item L<AnyEvent::Socket>
614		747
615	Provides a means to do non-blocking connects, accepts etc.	748	Provides various utility functions for (internet protocol) sockets,
		749	addresses and name resolution. Also functions to create non-blocking tcp
		750	connections or tcp servers, with IPv6 and SRV record support and more.
		751
		752	=item L<AnyEvent::DNS>
		753
		754	Provides rich asynchronous DNS resolver capabilities.
616		755
617	=item L<AnyEvent::HTTPD>	756	=item L<AnyEvent::HTTPD>
618		757
619	Provides a simple web application server framework.	758	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		759
626	=item L<AnyEvent::FastPing>	760	=item L<AnyEvent::FastPing>
627		761
628	The fastest ping in the west.	762	The fastest ping in the west.
629		763
…		…
644		778
645	High level API for event-based execution flow control.	779	High level API for event-based execution flow control.
646		780
647	=item L<Coro>	781	=item L<Coro>
648		782
649	Has special support for AnyEvent.	783	Has special support for AnyEvent via L<Coro::AnyEvent>.
		784
		785	=item L<AnyEvent::AIO>, L<IO::AIO>
		786
		787	Truly asynchronous I/O, should be in the toolbox of every event
		788	programmer. AnyEvent::AIO transparently fuses IO::AIO and AnyEvent
		789	together.
		790
		791	=item L<AnyEvent::BDB>, L<BDB>
		792
		793	Truly asynchronous Berkeley DB access. AnyEvent::AIO transparently fuses
		794	IO::AIO and AnyEvent together.
650		795
651	=item L<IO::Lambda>	796	=item L<IO::Lambda>
652		797
653	The lambda approach to I/O - don't ask, look there. Can use AnyEvent.	798	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		799
665	=back	800	=back
666		801
667	=cut	802	=cut
668		803
…		…
671	no warnings;	806	no warnings;
672	use strict;	807	use strict;
673		808
674	use Carp;	809	use Carp;
675		810
676	our $VERSION = '3.3';	811	our $VERSION = 4.11;
677	our $MODEL;	812	our $MODEL;
678		813
679	our $AUTOLOAD;	814	our $AUTOLOAD;
680	our @ISA;	815	our @ISA;
681		816
		817	our @REGISTRY;
		818
		819	our $WIN32;
		820
		821	BEGIN {
		822	my $win32 = ! ! ($^O =~ /mswin32/i);
		823	eval "sub WIN32(){ $win32 }";
		824	}
		825
682	our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1;	826	our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1;
683		827
684	our @REGISTRY;	828	our %PROTOCOL; # (ipv4\|ipv6) => (1\|2), higher numbers are preferred
		829
		830	{
		831	my $idx;
		832	$PROTOCOL{$_} = ++$idx
		833	for reverse split /\s,\s/,
		834	$ENV{PERL_ANYEVENT_PROTOCOLS} \|\| "ipv4,ipv6";
		835	}
685		836
686	my @models = (	837	my @models = (
687	[Coro::EV:: => AnyEvent::Impl::CoroEV::],
688	[Coro::Event:: => AnyEvent::Impl::CoroEvent::],
689	[EV:: => AnyEvent::Impl::EV::],	838	[EV:: => AnyEvent::Impl::EV::],
690	[Event:: => AnyEvent::Impl::Event::],	839	[Event:: => AnyEvent::Impl::Event::],
691	[Tk:: => AnyEvent::Impl::Tk::],
692	[Wx:: => AnyEvent::Impl::POE::],
693	[Prima:: => AnyEvent::Impl::POE::],
694	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::],	840	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::],
695	# everything below here will not be autoprobed as the pureperl backend should work everywhere	841	# everything below here will not be autoprobed
696	[Glib:: => AnyEvent::Impl::Glib::],	842	# as the pureperl backend should work everywhere
		843	# and is usually faster
		844	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
		845	[Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers
697	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy	846	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
698	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program	847	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program
699	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza	848	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
		849	[Wx:: => AnyEvent::Impl::POE::],
		850	[Prima:: => AnyEvent::Impl::POE::],
700	);	851	);
701		852
702	our %method = map +($_ => 1), qw(io timer signal child condvar one_event DESTROY);	853	our %method = map +($_ => 1), qw(io timer time now signal child condvar one_event DESTROY);
		854
		855	our @post_detect;
		856
		857	sub post_detect(&) {
		858	my ($cb) = @_;
		859
		860	if ($MODEL) {
		861	$cb->();
		862
		863	1
		864	} else {
		865	push @post_detect, $cb;
		866
		867	defined wantarray
		868	? bless \$cb, "AnyEvent::Util::PostDetect"
		869	: ()
		870	}
		871	}
		872
		873	sub AnyEvent::Util::PostDetect::DESTROY {
		874	@post_detect = grep $_ != ${$_[0]}, @post_detect;
		875	}
703		876
704	sub detect() {	877	sub detect() {
705	unless ($MODEL) {	878	unless ($MODEL) {
706	no strict 'refs';	879	no strict 'refs';
		880	local $SIG{__DIE__};
707		881
708	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {	882	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {
709	my $model = "AnyEvent::Impl::$1";	883	my $model = "AnyEvent::Impl::$1";
710	if (eval "require $model") {	884	if (eval "require $model") {
711	$MODEL = $model;	885	$MODEL = $model;
…		…
741	last;	915	last;
742	}	916	}
743	}	917	}
744		918
745	$MODEL	919	$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.";	920	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.";
747	}	921	}
748	}	922	}
749		923
750	unshift @ISA, $MODEL;	924	unshift @ISA, $MODEL;
751	push @{"$MODEL\::ISA"}, "AnyEvent::Base";	925	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
		926
		927	(shift @post_detect)->() while @post_detect;
752	}	928	}
753		929
754	$MODEL	930	$MODEL
755	}	931	}
756		932
…		…
766	$class->$func (@_);	942	$class->$func (@_);
767	}	943	}
768		944
769	package AnyEvent::Base;	945	package AnyEvent::Base;
770		946
		947	# default implementation for now and time
		948
		949	use Time::HiRes ();
		950
		951	sub time { Time::HiRes::time }
		952	sub now { Time::HiRes::time }
		953
771	# default implementation for ->condvar, ->wait, ->broadcast	954	# default implementation for ->condvar
772		955
773	sub condvar {	956	sub condvar {
774	bless \my $flag, "AnyEvent::Base::CondVar"	957	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	}	958	}
784		959
785	# default implementation for ->signal	960	# default implementation for ->signal
786		961
787	our %SIG_CB;	962	our %SIG_CB;
…		…
840	or Carp::croak "required option 'pid' is missing";	1015	or Carp::croak "required option 'pid' is missing";
841		1016
842	$PID_CB{$pid}{$arg{cb}} = $arg{cb};	1017	$PID_CB{$pid}{$arg{cb}} = $arg{cb};
843		1018
844	unless ($WNOHANG) {	1019	unless ($WNOHANG) {
845	$WNOHANG = eval { require POSIX; &POSIX::WNOHANG } \|\| 1;	1020	$WNOHANG = eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } \|\| 1;
846	}	1021	}
847		1022
848	unless ($CHLD_W) {	1023	unless ($CHLD_W) {
849	$CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld);	1024	$CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld);
850	# child could be a zombie already, so make at least one round	1025	# child could be a zombie already, so make at least one round
…		…
860	delete $PID_CB{$pid}{$cb};	1035	delete $PID_CB{$pid}{$cb};
861	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };	1036	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };
862		1037
863	undef $CHLD_W unless keys %PID_CB;	1038	undef $CHLD_W unless keys %PID_CB;
864	}	1039	}
		1040
		1041	package AnyEvent::CondVar;
		1042
		1043	our @ISA = AnyEvent::CondVar::Base::;
		1044
		1045	package AnyEvent::CondVar::Base;
		1046
		1047	use overload
		1048	'&{}' => sub { my $self = shift; sub { $self->send (@_) } },
		1049	fallback => 1;
		1050
		1051	sub _send {
		1052	# nop
		1053	}
		1054
		1055	sub send {
		1056	my $cv = shift;
		1057	$cv->{_ae_sent} = [@_];
		1058	(delete $cv->{_ae_cb})->($cv) if $cv->{_ae_cb};
		1059	$cv->_send;
		1060	}
		1061
		1062	sub croak {
		1063	$_[0]{_ae_croak} = $_[1];
		1064	$_[0]->send;
		1065	}
		1066
		1067	sub ready {
		1068	$_[0]{_ae_sent}
		1069	}
		1070
		1071	sub _wait {
		1072	AnyEvent->one_event while !$_[0]{_ae_sent};
		1073	}
		1074
		1075	sub recv {
		1076	$_[0]->_wait;
		1077
		1078	Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak};
		1079	wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0]
		1080	}
		1081
		1082	sub cb {
		1083	$_[0]{_ae_cb} = $_[1] if @_ > 1;
		1084	$_[0]{_ae_cb}
		1085	}
		1086
		1087	sub begin {
		1088	++$_[0]{_ae_counter};
		1089	$_[0]{_ae_end_cb} = $_[1] if @_ > 1;
		1090	}
		1091
		1092	sub end {
		1093	return if --$_[0]{_ae_counter};
		1094	&{ $_[0]{_ae_end_cb} \|\| sub { $_[0]->send } };
		1095	}
		1096
		1097	# undocumented/compatibility with pre-3.4
		1098	*broadcast = \&send;
		1099	*wait = \&_wait;
865		1100
866	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE	1101	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE
867		1102
868	This is an advanced topic that you do not normally need to use AnyEvent in	1103	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	1104	a module. This section is only of use to event loop authors who want to
…		…
926	model it chooses.	1161	model it chooses.
927		1162
928	=item C<PERL_ANYEVENT_MODEL>	1163	=item C<PERL_ANYEVENT_MODEL>
929		1164
930	This can be used to specify the event model to be used by AnyEvent, before	1165	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	1166	auto detection and -probing kicks in. It must be a string consisting
932	entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended	1167	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,	1168	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	1169	used as event model. If it fails to load AnyEvent will proceed with
935	autodetection and -probing.	1170	auto detection and -probing.
936		1171
937	This functionality might change in future versions.	1172	This functionality might change in future versions.
938		1173
939	For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you	1174	For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you
940	could start your program like this:	1175	could start your program like this:
941		1176
942	PERL_ANYEVENT_MODEL=Perl perl ...	1177	PERL_ANYEVENT_MODEL=Perl perl ...
		1178
		1179	=item C<PERL_ANYEVENT_PROTOCOLS>
		1180
		1181	Used by both L<AnyEvent::DNS> and L<AnyEvent::Socket> to determine preferences
		1182	for IPv4 or IPv6. The default is unspecified (and might change, or be the result
		1183	of auto probing).
		1184
		1185	Must be set to a comma-separated list of protocols or address families,
		1186	current supported: C<ipv4> and C<ipv6>. Only protocols mentioned will be
		1187	used, and preference will be given to protocols mentioned earlier in the
		1188	list.
		1189
		1190	This variable can effectively be used for denial-of-service attacks
		1191	against local programs (e.g. when setuid), although the impact is likely
		1192	small, as the program has to handle connection errors already-
		1193
		1194	Examples: C<PERL_ANYEVENT_PROTOCOLS=ipv4,ipv6> - prefer IPv4 over IPv6,
		1195	but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4>
		1196	- only support IPv4, never try to resolve or contact IPv6
		1197	addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or
		1198	IPv6, but prefer IPv6 over IPv4.
		1199
		1200	=item C<PERL_ANYEVENT_EDNS0>
		1201
		1202	Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension
		1203	for DNS. This extension is generally useful to reduce DNS traffic, but
		1204	some (broken) firewalls drop such DNS packets, which is why it is off by
		1205	default.
		1206
		1207	Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce
		1208	EDNS0 in its DNS requests.
		1209
		1210	=item C<PERL_ANYEVENT_MAX_FORKS>
		1211
		1212	The maximum number of child processes that C<AnyEvent::Util::fork_call>
		1213	will create in parallel.
943		1214
944	=back	1215	=back
945		1216
946	=head1 EXAMPLE PROGRAM	1217	=head1 EXAMPLE PROGRAM
947		1218
…		…
958	poll => 'r',	1229	poll => 'r',
959	cb => sub {	1230	cb => sub {
960	warn "io event <$_[0]>\n"; # will always output <r>	1231	warn "io event <$_[0]>\n"; # will always output <r>
961	chomp (my $input = <STDIN>); # read a line	1232	chomp (my $input = <STDIN>); # read a line
962	warn "read: $input\n"; # output what has been read	1233	warn "read: $input\n"; # output what has been read
963	$cv->broadcast if $input =~ /^q/i; # quit program if /^q/i	1234	$cv->send if $input =~ /^q/i; # quit program if /^q/i
964	},	1235	},
965	);	1236	);
966		1237
967	my $time_watcher; # can only be used once	1238	my $time_watcher; # can only be used once
968		1239
…		…
973	});	1244	});
974	}	1245	}
975		1246
976	new_timer; # create first timer	1247	new_timer; # create first timer
977		1248
978	$cv->wait; # wait until user enters /^q/i	1249	$cv->recv; # wait until user enters /^q/i
979		1250
980	=head1 REAL-WORLD EXAMPLE	1251	=head1 REAL-WORLD EXAMPLE
981		1252
982	Consider the L<Net::FCP> module. It features (among others) the following	1253	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:	1254	API calls, which are to freenet what HTTP GET requests are to http:
…		…
1033	syswrite $txn->{fh}, $txn->{request}	1304	syswrite $txn->{fh}, $txn->{request}
1034	or die "connection or write error";	1305	or die "connection or write error";
1035	$txn->{w} = AnyEvent->io (fh => $txn->{fh}, poll => 'r', cb => sub { $txn->fh_ready_r });	1306	$txn->{w} = AnyEvent->io (fh => $txn->{fh}, poll => 'r', cb => sub { $txn->fh_ready_r });
1036		1307
1037	Again, C<fh_ready_r> waits till all data has arrived, and then stores the	1308	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:	1309	result and signals any possible waiters that the request has finished:
1039		1310
1040	sysread $txn->{fh}, $txn->{buf}, length $txn->{$buf};	1311	sysread $txn->{fh}, $txn->{buf}, length $txn->{$buf};
1041		1312
1042	if (end-of-file or data complete) {	1313	if (end-of-file or data complete) {
1043	$txn->{result} = $txn->{buf};	1314	$txn->{result} = $txn->{buf};
1044	$txn->{finished}->broadcast;	1315	$txn->{finished}->send;
1045	$txb->{cb}->($txn) of $txn->{cb}; # also call callback	1316	$txb->{cb}->($txn) of $txn->{cb}; # also call callback
1046	}	1317	}
1047		1318
1048	The C<result> method, finally, just waits for the finished signal (if the	1319	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	1320	request was already finished, it doesn't wait, of course, and returns the
1050	data:	1321	data:
1051		1322
1052	$txn->{finished}->wait;	1323	$txn->{finished}->recv;
1053	return $txn->{result};	1324	return $txn->{result};
1054		1325
1055	The actual code goes further and collects all errors (C<die>s, exceptions)	1326	The actual code goes further and collects all errors (C<die>s, exceptions)
1056	that occured during request processing. The C<result> method detects	1327	that occurred during request processing. The C<result> method detects
1057	whether an exception as thrown (it is stored inside the $txn object)	1328	whether an exception as thrown (it is stored inside the $txn object)
1058	and just throws the exception, which means connection errors and other	1329	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	1330	problems get reported tot he code that tries to use the result, not in a
1060	random callback.	1331	random callback.
1061		1332
…		…
1092		1363
1093	my $quit = AnyEvent->condvar;	1364	my $quit = AnyEvent->condvar;
1094		1365
1095	$fcp->txn_client_get ($url)->cb (sub {	1366	$fcp->txn_client_get ($url)->cb (sub {
1096	...	1367	...
1097	$quit->broadcast;	1368	$quit->send;
1098	});	1369	});
1099		1370
1100	$quit->wait;	1371	$quit->recv;
1101		1372
1102		1373
1103	=head1 BENCHMARKS	1374	=head1 BENCHMARKS
1104		1375
1105	To give you an idea of the performance and overheads that AnyEvent adds	1376	To give you an idea of the performance and overheads that AnyEvent adds
…		…
1107	of various event loops I prepared some benchmarks.	1378	of various event loops I prepared some benchmarks.
1108		1379
1109	=head2 BENCHMARKING ANYEVENT OVERHEAD	1380	=head2 BENCHMARKING ANYEVENT OVERHEAD
1110		1381
1111	Here is a benchmark of various supported event models used natively and	1382	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	1383	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,	1384	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.	1385	which it is), lets them fire exactly once and destroys them again.
1115		1386
1116	Source code for this benchmark is found as F<eg/bench> in the AnyEvent	1387	Source code for this benchmark is found as F<eg/bench> in the AnyEvent
1117	distribution.	1388	distribution.
…		…
1134	all watchers, to avoid adding memory overhead. That means closure creation	1405	all watchers, to avoid adding memory overhead. That means closure creation
1135	and memory usage is not included in the figures.	1406	and memory usage is not included in the figures.
1136		1407
1137	I<invoke> is the time, in microseconds, used to invoke a simple	1408	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	1409	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	1410	invoked "watcher" times, it would C<< ->send >> a condvar once to
1140	signal the end of this phase.	1411	signal the end of this phase.
1141		1412
1142	I<destroy> is the time, in microseconds, that it takes to destroy a single	1413	I<destroy> is the time, in microseconds, that it takes to destroy a single
1143	watcher.	1414	watcher.
1144		1415
…		…
1240		1511
1241	=back	1512	=back
1242		1513
1243	=head2 BENCHMARKING THE LARGE SERVER CASE	1514	=head2 BENCHMARKING THE LARGE SERVER CASE
1244		1515
1245	This benchmark atcually benchmarks the event loop itself. It works by	1516	This benchmark actually benchmarks the event loop itself. It works by
1246	creating a number of "servers": each server consists of a socketpair, a	1517	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	1518	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	1519	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".	1520	watcher reads a byte it will write that byte to a random other "server".
1250		1521
1251	The effect is that there will be a lot of I/O watchers, only part of which	1522	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	1523	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	1524	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	1525	timeout is reset each time something is read because that reflects how
1255	most timeouts work (and puts extra pressure on the event loops).	1526	most timeouts work (and puts extra pressure on the event loops).
1256		1527
1257	In this benchmark, we use 10000 socketpairs (20000 sockets), of which 100	1528	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	1529	(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.	1530	connections, most of which are idle at any one point in time.
1260		1531
1261	Source code for this benchmark is found as F<eg/bench2> in the AnyEvent	1532	Source code for this benchmark is found as F<eg/bench2> in the AnyEvent
1262	distribution.	1533	distribution.
…		…
1264	=head3 Explanation of the columns	1535	=head3 Explanation of the columns
1265		1536
1266	I<sockets> is the number of sockets, and twice the number of "servers" (as	1537	I<sockets> is the number of sockets, and twice the number of "servers" (as
1267	each server has a read and write socket end).	1538	each server has a read and write socket end).
1268		1539
1269	I<create> is the time it takes to create a socketpair (which is	1540	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.	1541	nontrivial) and two watchers: an I/O watcher and a timeout watcher.
1271		1542
1272	I<request>, the most important value, is the time it takes to handle a	1543	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	1544	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	1545	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	1618	speed most when you have lots of watchers, not when you only have a few of
1348	them).	1619	them).
1349		1620
1350	EV is again fastest.	1621	EV is again fastest.
1351		1622
1352	Perl again comes second. It is noticably faster than the C-based event	1623	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	1624	loops Event and Glib, although the difference is too small to really
1354	matter.	1625	matter.
1355		1626
1356	POE also performs much better in this case, but is is still far behind the	1627	POE also performs much better in this case, but is is still far behind the
1357	others.	1628	others.
…		…
1397	probably even less useful to an attacker than PERL_ANYEVENT_MODEL).	1668	probably even less useful to an attacker than PERL_ANYEVENT_MODEL).
1398		1669
1399		1670
1400	=head1 SEE ALSO	1671	=head1 SEE ALSO
1401		1672
1402	Event modules: L<Coro::EV>, L<EV>, L<EV::Glib>, L<Glib::EV>,	1673	Utility functions: L<AnyEvent::Util>.
1403	L<Coro::Event>, L<Event>, L<Glib::Event>, L<Glib>, L<Coro>, L<Tk>,	1674
		1675	Event modules: L<EV>, L<EV::Glib>, L<Glib::EV>, L<Event>, L<Glib::Event>,
1404	L<Event::Lib>, L<Qt>, L<POE>.	1676	L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.
1405		1677
1406	Implementations: L<AnyEvent::Impl::CoroEV>, L<AnyEvent::Impl::EV>,	1678	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,
1407	L<AnyEvent::Impl::CoroEvent>, L<AnyEvent::Impl::Event>, L<AnyEvent::Impl::Glib>,	1679	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>,	1680	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,
1409	L<AnyEvent::Impl::Qt>, L<AnyEvent::Impl::POE>.	1681	L<AnyEvent::Impl::POE>.
1410		1682
		1683	Non-blocking file handles, sockets, TCP clients and
		1684	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>.
		1685
		1686	Asynchronous DNS: L<AnyEvent::DNS>.
		1687
		1688	Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>,
		1689
1411	Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>.	1690	Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>, L<AnyEvent::DNS>.
1412		1691
1413		1692
1414	=head1 AUTHOR	1693	=head1 AUTHOR
1415		1694
1416	Marc Lehmann <schmorp@schmorp.de>	1695	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 1.148 by root, Sat May 31 00:40:16 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 1.148 by root, Sat May 31 00:40:16 2008 UTC