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

Comparing AnyEvent/lib/AnyEvent.pm (file contents):
Revision 1.82 by root, Fri Apr 25 13:32:39 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 ->broadcast	21	$w->recv; # enters "main loop" till $condvar gets ->send
21	$w->broadcast; # 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
71		82
72	=head1 DESCRIPTION	83	=head1 DESCRIPTION
73		84
74	L<AnyEvent> provides an identical interface to multiple event loops. This	85	L<AnyEvent> provides an identical interface to multiple event loops. This
75	allows module authors to utilise an event loop without forcing module	86	allows module authors to utilise an event loop without forcing module
…		…
79	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>
80	module.	91	module.
81		92
82	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
83	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
84	following modules is already loaded: L<Coro::EV>, L<Coro::Event>, L<EV>,	95	following modules is already loaded: L<EV>,
85	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>,
86	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
87	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
88	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
89	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
…		…
103	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
104	use AnyEvent so their modules work together with others seamlessly...	115	use AnyEvent so their modules work together with others seamlessly...
105		116
106	The pure-perl implementation of AnyEvent is called	117	The pure-perl implementation of AnyEvent is called
107	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
108	explicitly.	119	explicitly and enjoy the high availability of that event loop :)
109		120
110	=head1 WATCHERS	121	=head1 WATCHERS
111		122
112	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
113	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
114	the callback to call, the filehandle to watch, etc.	125	the callback to call, the file handle to watch, etc.
115		126
116	These watchers are normal Perl objects with normal Perl lifetime. After	127	These watchers are normal Perl objects with normal Perl lifetime. After
117	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
118	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
119	is in control).	130	is in control).
…		…
141	=head2 I/O WATCHERS	152	=head2 I/O WATCHERS
142		153
143	You can create an I/O watcher by calling the C<< AnyEvent->io >> method	154	You can create an I/O watcher by calling the C<< AnyEvent->io >> method
144	with the following mandatory key-value pairs as arguments:	155	with the following mandatory key-value pairs as arguments:
145		156
146	C<fh> the Perl I<file handle> (I<not> file descriptor) to watch for	157	C<fh> the Perl I<file handle> (I<not> file descriptor) to watch
147	events. C<poll> must be a string that is either C<r> or C<w>, which	158	for events. C<poll> must be a string that is either C<r> or C<w>,
148	creates a watcher waiting for "r"eadable or "w"ritable events,	159	which creates a watcher waiting for "r"eadable or "w"ritable events,
149	respectively. C<cb> is the callback to invoke each time the file handle	160	respectively. C<cb> is the callback to invoke each time the file handle
150	becomes ready.	161	becomes ready.
151		162
		163	Although the callback might get passed parameters, their value and
		164	presence is undefined and you cannot rely on them. Portable AnyEvent
		165	callbacks cannot use arguments passed to I/O watcher callbacks.
		166
152	The I/O watcher might use the underlying file descriptor or a copy of it.	167	The I/O watcher might use the underlying file descriptor or a copy of it.
153	It is not allowed to close a file handle as long as any watcher is active	168	You must not close a file handle as long as any watcher is active on the
154	on the underlying file descriptor.	169	underlying file descriptor.
155		170
156	Some event loops issue spurious readyness notifications, so you should	171	Some event loops issue spurious readyness notifications, so you should
157	always use non-blocking calls when reading/writing from/to your file	172	always use non-blocking calls when reading/writing from/to your file
158	handles.	173	handles.
159		174
…		…
170		185
171	You can create a time watcher by calling the C<< AnyEvent->timer >>	186	You can create a time watcher by calling the C<< AnyEvent->timer >>
172	method with the following mandatory arguments:	187	method with the following mandatory arguments:
173		188
174	C<after> specifies after how many seconds (fractional values are	189	C<after> specifies after how many seconds (fractional values are
175	supported) should the timer activate. C<cb> the callback to invoke in that	190	supported) the callback should be invoked. C<cb> is the callback to invoke
176	case.	191	in that case.
		192
		193	Although the callback might get passed parameters, their value and
		194	presence is undefined and you cannot rely on them. Portable AnyEvent
		195	callbacks cannot use arguments passed to time watcher callbacks.
177		196
178	The timer callback will be invoked at most once: if you want a repeating	197	The timer callback will be invoked at most once: if you want a repeating
179	timer you have to create a new watcher (this is a limitation by both Tk	198	timer you have to create a new watcher (this is a limitation by both Tk
180	and Glib).	199	and Glib).
181		200
…		…
220	timers.	239	timers.
221		240
222	AnyEvent always prefers relative timers, if available, matching the	241	AnyEvent always prefers relative timers, if available, matching the
223	AnyEvent API.	242	AnyEvent API.
224		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
225	=head2 SIGNAL WATCHERS	307	=head2 SIGNAL WATCHERS
226		308
227	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
228	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
229	be invoked whenever a signal occurs.	311	be invoked whenever a signal occurs.
230		312
		313	Although the callback might get passed parameters, their value and
		314	presence is undefined and you cannot rely on them. Portable AnyEvent
		315	callbacks cannot use arguments passed to signal watcher callbacks.
		316
231	Multiple signal occurances can be clumped together into one callback	317	Multiple signal occurrences can be clumped together into one callback
232	invocation, and callback invocation will be synchronous. synchronous means	318	invocation, and callback invocation will be synchronous. Synchronous means
233	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,
234	but it is guarenteed not to interrupt any other callbacks.	320	but it is guaranteed not to interrupt any other callbacks.
235		321
236	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
237	between multiple watchers.	323	between multiple watchers.
238		324
239	This watcher might use C<%SIG>, so programs overwriting those signals	325	This watcher might use C<%SIG>, so programs overwriting those signals
…		…
249		335
250	The child process is specified by the C<pid> argument (if set to C<0>, it	336	The child process is specified by the C<pid> argument (if set to C<0>, it
251	watches for any child process exit). The watcher will trigger as often	337	watches for any child process exit). The watcher will trigger as often
252	as status change for the child are received. This works by installing a	338	as status change for the child are received. This works by installing a
253	signal handler for C<SIGCHLD>. The callback will be called with the pid	339	signal handler for C<SIGCHLD>. The callback will be called with the pid
254	and exit status (as returned by waitpid).	340	and exit status (as returned by waitpid), so unlike other watcher types,
		341	you I<can> rely on child watcher callback arguments.
255		342
256	There is a slight catch to child watchers, however: you usually start them	343	There is a slight catch to child watchers, however: you usually start them
257	I<after> the child process was created, and this means the process could	344	I<after> the child process was created, and this means the process could
258	have exited already (and no SIGCHLD will be sent anymore).	345	have exited already (and no SIGCHLD will be sent anymore).
259		346
…		…
266	C<fork> the child (alternatively, you can call C<AnyEvent::detect>).	353	C<fork> the child (alternatively, you can call C<AnyEvent::detect>).
267		354
268	Example: fork a process and wait for it	355	Example: fork a process and wait for it
269		356
270	my $done = AnyEvent->condvar;	357	my $done = AnyEvent->condvar;
271
272	AnyEvent::detect; # force event module to be initialised
273		358
274	my $pid = fork or exit 5;	359	my $pid = fork or exit 5;
275		360
276	my $w = AnyEvent->child (	361	my $w = AnyEvent->child (
277	pid => $pid,	362	pid => $pid,
278	cb => sub {	363	cb => sub {
279	my ($pid, $status) = @_;	364	my ($pid, $status) = @_;
280	warn "pid $pid exited with status $status";	365	warn "pid $pid exited with status $status";
281	$done->broadcast;	366	$done->send;
282	},	367	},
283	);	368	);
284		369
285	# do something else, then wait for process exit	370	# do something else, then wait for process exit
286	$done->wait;	371	$done->recv;
287		372
288	=head2 CONDITION VARIABLES	373	=head2 CONDITION VARIABLES
289		374
		375	If you are familiar with some event loops you will know that all of them
		376	require you to run some blocking "loop", "run" or similar function that
		377	will actively watch for new events and call your callbacks.
		378
		379	AnyEvent is different, it expects somebody else to run the event loop and
		380	will only block when necessary (usually when told by the user).
		381
		382	The instrument to do that is called a "condition variable", so called
		383	because they represent a condition that must become true.
		384
290	Condition variables can be created by calling the C<< AnyEvent->condvar >>	385	Condition variables can be created by calling the C<< AnyEvent->condvar
291	method without any arguments.	386	>> method, usually without arguments. The only argument pair allowed is
		387	C<cb>, which specifies a callback to be called when the condition variable
		388	becomes true.
292		389
293	A condition variable waits for a condition - precisely that the C<<	390	After creation, the condition variable is "false" until it becomes "true"
294	->broadcast >> method has been called.	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).
295		394
296	They are very useful to signal that a condition has been fulfilled, for	395	Condition variables are similar to callbacks, except that you can
		396	optionally wait for them. They can also be called merge points - points
		397	in time where multiple outstanding events have been processed. And yet
		398	another way to call them is transactions - each condition variable can be
		399	used to represent a transaction, which finishes at some point and delivers
		400	a result.
		401
		402	Condition variables are very useful to signal that something has finished,
297	example, if you write a module that does asynchronous http requests,	403	for example, if you write a module that does asynchronous http requests,
298	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
299	availability of results.	405	availability of results. The user can either act when the callback is
		406	called or can synchronously C<< ->recv >> for the results.
300		407
301	You can also use condition variables to block your main program until	408	You can also use them to simulate traditional event loops - for example,
302	an event occurs - for example, you could C<< ->wait >> in your main	409	you can block your main program until an event occurs - for example, you
303	program until the user clicks the Quit button in your app, which would C<<	410	could C<< ->recv >> in your main program until the user clicks the Quit
304	->broadcast >> the "quit" event.	411	button of your app, which would C<< ->send >> the "quit" event.
305		412
306	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
307	two pirces 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
308	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
309	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,
310	as this asks for trouble.	417	as this asks for trouble.
311		418
312	This object has two methods:	419	Condition variables are represented by hash refs in perl, and the keys
		420	used by AnyEvent itself are all named C<_ae_XXX> to make subclassing
		421	easy (it is often useful to build your own transaction class on top of
		422	AnyEvent). To subclass, use C<AnyEvent::CondVar> as base class and call
		423	it's C<new> method in your own C<new> method.
		424
		425	There are two "sides" to a condition variable - the "producer side" which
		426	eventually calls C<< -> send >>, and the "consumer side", which waits
		427	for the send to occur.
		428
		429	Example: wait for a timer.
		430
		431	# wait till the result is ready
		432	my $result_ready = AnyEvent->condvar;
		433
		434	# do something such as adding a timer
		435	# or socket watcher the calls $result_ready->send
		436	# when the "result" is ready.
		437	# in this case, we simply use a timer:
		438	my $w = AnyEvent->timer (
		439	after => 1,
		440	cb => sub { $result_ready->send },
		441	);
		442
		443	# this "blocks" (while handling events) till the callback
		444	# calls send
		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;
		453
		454	=head3 METHODS FOR PRODUCERS
		455
		456	These methods should only be used by the producing side, i.e. the
		457	code/module that eventually sends the signal. Note that it is also
		458	the producer side which creates the condvar in most cases, but it isn't
		459	uncommon for the consumer to create it as well.
313		460
314	=over 4	461	=over 4
315		462
		463	=item $cv->send (...)
		464
		465	Flag the condition as ready - a running C<< ->recv >> and all further
		466	calls to C<recv> will (eventually) return after this method has been
		467	called. If nobody is waiting the send will be remembered.
		468
		469	If a callback has been set on the condition variable, it is called
		470	immediately from within send.
		471
		472	Any arguments passed to the C<send> call will be returned by all
		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).
		483
		484	=item $cv->croak ($error)
		485
		486	Similar to send, but causes all call's to C<< ->recv >> to invoke
		487	C<Carp::croak> with the given error message/object/scalar.
		488
		489	This can be used to signal any errors to the condition variable
		490	user/consumer.
		491
		492	=item $cv->begin ([group callback])
		493
316	=item $cv->wait	494	=item $cv->end
317		495
318	Wait (blocking if necessary) until the C<< ->broadcast >> method has been	496	These two methods are EXPERIMENTAL and MIGHT CHANGE.
		497
		498	These two methods can be used to combine many transactions/events into
		499	one. For example, a function that pings many hosts in parallel might want
		500	to use a condition variable for the whole process.
		501
		502	Every call to C<< ->begin >> will increment a counter, and every call to
		503	C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end
		504	>>, the (last) callback passed to C<begin> will be executed. That callback
		505	is I<supposed> to call C<< ->send >>, but that is not required. If no
		506	callback was set, C<send> will be called without any arguments.
		507
		508	Let's clarify this with the ping example:
		509
		510	my $cv = AnyEvent->condvar;
		511
		512	my %result;
		513	$cv->begin (sub { $cv->send (\%result) });
		514
		515	for my $host (@list_of_hosts) {
		516	$cv->begin;
		517	ping_host_then_call_callback $host, sub {
		518	$result{$host} = ...;
		519	$cv->end;
		520	};
		521	}
		522
		523	$cv->end;
		524
		525	This code fragment supposedly pings a number of hosts and calls
		526	C<send> after results for all then have have been gathered - in any
		527	order. To achieve this, the code issues a call to C<begin> when it starts
		528	each ping request and calls C<end> when it has received some result for
		529	it. Since C<begin> and C<end> only maintain a counter, the order in which
		530	results arrive is not relevant.
		531
		532	There is an additional bracketing call to C<begin> and C<end> outside the
		533	loop, which serves two important purposes: first, it sets the callback
		534	to be called once the counter reaches C<0>, and second, it ensures that
		535	C<send> is called even when C<no> hosts are being pinged (the loop
		536	doesn't execute once).
		537
		538	This is the general pattern when you "fan out" into multiple subrequests:
		539	use an outer C<begin>/C<end> pair to set the callback and ensure C<end>
		540	is called at least once, and then, for each subrequest you start, call
		541	C<begin> and for each subrequest you finish, call C<end>.
		542
		543	=back
		544
		545	=head3 METHODS FOR CONSUMERS
		546
		547	These methods should only be used by the consuming side, i.e. the
		548	code awaits the condition.
		549
		550	=over 4
		551
		552	=item $cv->recv
		553
		554	Wait (blocking if necessary) until the C<< ->send >> or C<< ->croak
319	called on c<$cv>, while servicing other watchers normally.	555	>> methods have been called on c<$cv>, while servicing other watchers
		556	normally.
320		557
321	You can only wait once on a condition - additional calls will return	558	You can only wait once on a condition - additional calls are valid but
322	immediately.	559	will return immediately.
		560
		561	If an error condition has been set by calling C<< ->croak >>, then this
		562	function will call C<croak>.
		563
		564	In list context, all parameters passed to C<send> will be returned,
		565	in scalar context only the first one will be returned.
323		566
324	Not all event models support a blocking wait - some die in that case	567	Not all event models support a blocking wait - some die in that case
325	(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
326	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
327	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
328	condition variables with some kind of request results and supporting	571	condition variables with some kind of request results and supporting
329	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,
330	while still suppporting blocking waits if the caller so desires).	573	while still supporting blocking waits if the caller so desires).
331		574
332	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
333	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
334	multiple interpreters or coroutines/threads, none of which C<AnyEvent>	577	multiple interpreters or coroutines/threads, none of which C<AnyEvent>
335	can supply (the coroutine-aware backends L<AnyEvent::Impl::CoroEV> and	578	can supply.
336	L<AnyEvent::Impl::CoroEvent> explicitly support concurrent C<< ->wait >>'s
337	from different coroutines, however).
338		579
339	=item $cv->broadcast	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).
340		585
341	Flag the condition as ready - a running C<< ->wait >> and all further	586	You can ensure that C<< -recv >> never blocks by setting a callback and
342	calls to C<wait> will (eventually) return after this method has been	587	only calling C<< ->recv >> from within that callback (or at a later
343	called. If nobody is waiting the broadcast will be remembered..	588	time). This will work even when the event loop does not support blocking
		589	waits otherwise.
		590
		591	=item $bool = $cv->ready
		592
		593	Returns true when the condition is "true", i.e. whether C<send> or
		594	C<croak> have been called.
		595
		596	=item $cb = $cv->cb ([new callback])
		597
		598	This is a mutator function that returns the callback set and optionally
		599	replaces it before doing so.
		600
		601	The callback will be called when the condition becomes "true", i.e. when
		602	C<send> or C<croak> are called. Calling C<recv> inside the callback
		603	or at any later time is guaranteed not to block.
344		604
345	=back	605	=back
346
347	Example:
348
349	# wait till the result is ready
350	my $result_ready = AnyEvent->condvar;
351
352	# do something such as adding a timer
353	# or socket watcher the calls $result_ready->broadcast
354	# when the "result" is ready.
355	# in this case, we simply use a timer:
356	my $w = AnyEvent->timer (
357	after => 1,
358	cb => sub { $result_ready->broadcast },
359	);
360
361	# this "blocks" (while handling events) till the watcher
362	# calls broadcast
363	$result_ready->wait;
364		606
365	=head1 GLOBAL VARIABLES AND FUNCTIONS	607	=head1 GLOBAL VARIABLES AND FUNCTIONS
366		608
367	=over 4	609	=over 4
368		610
…		…
374	C<AnyEvent::Impl:xxx> modules, but can be any other class in the case	616	C<AnyEvent::Impl:xxx> modules, but can be any other class in the case
375	AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode>).	617	AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode>).
376		618
377	The known classes so far are:	619	The known classes so far are:
378		620
379	AnyEvent::Impl::CoroEV based on Coro::EV, best choice.
380	AnyEvent::Impl::CoroEvent based on Coro::Event, second best choice.
381	AnyEvent::Impl::EV based on EV (an interface to libev, best choice).	621	AnyEvent::Impl::EV based on EV (an interface to libev, best choice).
382	AnyEvent::Impl::Event based on Event, second best choice.	622	AnyEvent::Impl::Event based on Event, second best choice.
		623	AnyEvent::Impl::Perl pure-perl implementation, fast and portable.
383	AnyEvent::Impl::Glib based on Glib, third-best choice.	624	AnyEvent::Impl::Glib based on Glib, third-best choice.
384	AnyEvent::Impl::Perl pure-perl implementation, inefficient but portable.
385	AnyEvent::Impl::Tk based on Tk, very bad choice.	625	AnyEvent::Impl::Tk based on Tk, very bad choice.
386	AnyEvent::Impl::Qt based on Qt, cannot be autoprobed (see its docs).	626	AnyEvent::Impl::Qt based on Qt, cannot be autoprobed (see its docs).
387	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.	627	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
388	AnyEvent::Impl::POE based on POE, not generic enough for full support.	628	AnyEvent::Impl::POE based on POE, not generic enough for full support.
389		629
…		…
402	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model	642	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model
403	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
404	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
405	runtime.	645	runtime.
406		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
407	=back	668	=back
408		669
409	=head1 WHAT TO DO IN A MODULE	670	=head1 WHAT TO DO IN A MODULE
410		671
411	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
…		…
414	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
415	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
416	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
417	to load the event module first.	678	to load the event module first.
418		679
419	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
420	the C<< ->broadcast >> method has been called on it already. This is	681	the C<< ->send >> method has been called on it already. This is
421	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
422	events is to stay interactive.	683	events is to stay interactive.
423		684
424	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
425	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
426	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 >>
427	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).
428		689
429	=head1 WHAT TO DO IN THE MAIN PROGRAM	690	=head1 WHAT TO DO IN THE MAIN PROGRAM
430		691
431	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
…		…
433		694
434	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
435	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
436	decide which implementation to chose if some module relies on it.	697	decide which implementation to chose if some module relies on it.
437		698
438	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
439	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
440	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
441	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
442	modules might create watchers when they are loaded, and AnyEvent will	703	modules might create watchers when they are loaded, and AnyEvent will
443	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
444	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.
445		706
446	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
447	loading the C<AnyEvent::Impl::Perl> module, which gives you similar	708	C<AnyEvent::Impl::Perl> module, which gives you similar behaviour
448	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
		727
		728	=head1 OTHER MODULES
		729
		730	The following is a non-exhaustive list of additional modules that use
		731	AnyEvent and can therefore be mixed easily with other AnyEvent modules
		732	in the same program. Some of the modules come with AnyEvent, some are
		733	available via CPAN.
		734
		735	=over 4
		736
		737	=item L<AnyEvent::Util>
		738
		739	Contains various utility functions that replace often-used but blocking
		740	functions such as C<inet_aton> by event-/callback-based versions.
		741
		742	=item L<AnyEvent::Handle>
		743
		744	Provide read and write buffers and manages watchers for reads and writes.
		745
		746	=item L<AnyEvent::Socket>
		747
		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.
		755
		756	=item L<AnyEvent::HTTPD>
		757
		758	Provides a simple web application server framework.
		759
		760	=item L<AnyEvent::FastPing>
		761
		762	The fastest ping in the west.
		763
		764	=item L<Net::IRC3>
		765
		766	AnyEvent based IRC client module family.
		767
		768	=item L<Net::XMPP2>
		769
		770	AnyEvent based XMPP (Jabber protocol) module family.
		771
		772	=item L<Net::FCP>
		773
		774	AnyEvent-based implementation of the Freenet Client Protocol, birthplace
		775	of AnyEvent.
		776
		777	=item L<Event::ExecFlow>
		778
		779	High level API for event-based execution flow control.
		780
		781	=item L<Coro>
		782
		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.
		795
		796	=item L<IO::Lambda>
		797
		798	The lambda approach to I/O - don't ask, look there. Can use AnyEvent.
		799
		800	=back
449		801
450	=cut	802	=cut
451		803
452	package AnyEvent;	804	package AnyEvent;
453		805
454	no warnings;	806	no warnings;
455	use strict;	807	use strict;
456		808
457	use Carp;	809	use Carp;
458		810
459	our $VERSION = '3.3';	811	our $VERSION = 4.11;
460	our $MODEL;	812	our $MODEL;
461		813
462	our $AUTOLOAD;	814	our $AUTOLOAD;
463	our @ISA;	815	our @ISA;
464		816
		817	our @REGISTRY;
		818
		819	our $WIN32;
		820
		821	BEGIN {
		822	my $win32 = ! ! ($^O =~ /mswin32/i);
		823	eval "sub WIN32(){ $win32 }";
		824	}
		825
465	our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1;	826	our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1;
466		827
467	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	$ENV{PERL_ANYEVENT_PROTOCOLS} \|\| "ipv4,ipv6";
		835	}
468		836
469	my @models = (	837	my @models = (
470	[Coro::EV:: => AnyEvent::Impl::CoroEV::],
471	[Coro::Event:: => AnyEvent::Impl::CoroEvent::],
472	[EV:: => AnyEvent::Impl::EV::],	838	[EV:: => AnyEvent::Impl::EV::],
473	[Event:: => AnyEvent::Impl::Event::],	839	[Event:: => AnyEvent::Impl::Event::],
474	[Glib:: => AnyEvent::Impl::Glib::],
475	[Tk:: => AnyEvent::Impl::Tk::],
476	[Wx:: => AnyEvent::Impl::POE::],
477	[Prima:: => AnyEvent::Impl::POE::],
478	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::],	840	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::],
479	# everything below here will not be autoprobed as the pureperl backend should work everywhere	841	# everything below here will not be autoprobed
		842	# as the pureperl backend should work everywhere
		843	# and is usually faster
		844	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
		845	[Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers
480	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy	846	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
481	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program	847	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program
482	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza	848	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
		849	[Wx:: => AnyEvent::Impl::POE::],
		850	[Prima:: => AnyEvent::Impl::POE::],
483	);	851	);
484		852
485	our %method = map +($_ => 1), qw(io timer signal child condvar broadcast wait 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	}
486		876
487	sub detect() {	877	sub detect() {
488	unless ($MODEL) {	878	unless ($MODEL) {
489	no strict 'refs';	879	no strict 'refs';
		880	local $SIG{__DIE__};
490		881
491	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {	882	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {
492	my $model = "AnyEvent::Impl::$1";	883	my $model = "AnyEvent::Impl::$1";
493	if (eval "require $model") {	884	if (eval "require $model") {
494	$MODEL = $model;	885	$MODEL = $model;
…		…
524	last;	915	last;
525	}	916	}
526	}	917	}
527		918
528	$MODEL	919	$MODEL
529	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.";
530	}	921	}
531	}	922	}
532		923
533	unshift @ISA, $MODEL;	924	unshift @ISA, $MODEL;
534	push @{"$MODEL\::ISA"}, "AnyEvent::Base";	925	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
		926
		927	(shift @post_detect)->() while @post_detect;
535	}	928	}
536		929
537	$MODEL	930	$MODEL
538	}	931	}
539		932
…		…
549	$class->$func (@_);	942	$class->$func (@_);
550	}	943	}
551		944
552	package AnyEvent::Base;	945	package AnyEvent::Base;
553		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
554	# default implementation for ->condvar, ->wait, ->broadcast	954	# default implementation for ->condvar
555		955
556	sub condvar {	956	sub condvar {
557	bless \my $flag, "AnyEvent::Base::CondVar"	957	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, AnyEvent::CondVar::
558	}
559
560	sub AnyEvent::Base::CondVar::broadcast {
561	${$_[0]}++;
562	}
563
564	sub AnyEvent::Base::CondVar::wait {
565	AnyEvent->one_event while !${$_[0]};
566	}	958	}
567		959
568	# default implementation for ->signal	960	# default implementation for ->signal
569		961
570	our %SIG_CB;	962	our %SIG_CB;
…		…
623	or Carp::croak "required option 'pid' is missing";	1015	or Carp::croak "required option 'pid' is missing";
624		1016
625	$PID_CB{$pid}{$arg{cb}} = $arg{cb};	1017	$PID_CB{$pid}{$arg{cb}} = $arg{cb};
626		1018
627	unless ($WNOHANG) {	1019	unless ($WNOHANG) {
628	$WNOHANG = eval { require POSIX; &POSIX::WNOHANG } \|\| 1;	1020	$WNOHANG = eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } \|\| 1;
629	}	1021	}
630		1022
631	unless ($CHLD_W) {	1023	unless ($CHLD_W) {
632	$CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld);	1024	$CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld);
633	# 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
…		…
643	delete $PID_CB{$pid}{$cb};	1035	delete $PID_CB{$pid}{$cb};
644	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };	1036	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };
645		1037
646	undef $CHLD_W unless keys %PID_CB;	1038	undef $CHLD_W unless keys %PID_CB;
647	}	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;
648		1100
649	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE	1101	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE
650		1102
651	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
652	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
…		…
709	model it chooses.	1161	model it chooses.
710		1162
711	=item C<PERL_ANYEVENT_MODEL>	1163	=item C<PERL_ANYEVENT_MODEL>
712		1164
713	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
714	autodetection and -probing kicks in. It must be a string consisting	1166	auto detection and -probing kicks in. It must be a string consisting
715	entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended	1167	entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended
716	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,
717	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
718	autodetection and -probing.	1170	auto detection and -probing.
719		1171
720	This functionality might change in future versions.	1172	This functionality might change in future versions.
721		1173
722	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
723	could start your program like this:	1175	could start your program like this:
724		1176
725	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.
726		1214
727	=back	1215	=back
728		1216
729	=head1 EXAMPLE PROGRAM	1217	=head1 EXAMPLE PROGRAM
730		1218
…		…
741	poll => 'r',	1229	poll => 'r',
742	cb => sub {	1230	cb => sub {
743	warn "io event <$_[0]>\n"; # will always output <r>	1231	warn "io event <$_[0]>\n"; # will always output <r>
744	chomp (my $input = <STDIN>); # read a line	1232	chomp (my $input = <STDIN>); # read a line
745	warn "read: $input\n"; # output what has been read	1233	warn "read: $input\n"; # output what has been read
746	$cv->broadcast if $input =~ /^q/i; # quit program if /^q/i	1234	$cv->send if $input =~ /^q/i; # quit program if /^q/i
747	},	1235	},
748	);	1236	);
749		1237
750	my $time_watcher; # can only be used once	1238	my $time_watcher; # can only be used once
751		1239
…		…
756	});	1244	});
757	}	1245	}
758		1246
759	new_timer; # create first timer	1247	new_timer; # create first timer
760		1248
761	$cv->wait; # wait until user enters /^q/i	1249	$cv->recv; # wait until user enters /^q/i
762		1250
763	=head1 REAL-WORLD EXAMPLE	1251	=head1 REAL-WORLD EXAMPLE
764		1252
765	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
766	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:
…		…
816	syswrite $txn->{fh}, $txn->{request}	1304	syswrite $txn->{fh}, $txn->{request}
817	or die "connection or write error";	1305	or die "connection or write error";
818	$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 });
819		1307
820	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
821	result and signals any possible waiters that the request ahs finished:	1309	result and signals any possible waiters that the request has finished:
822		1310
823	sysread $txn->{fh}, $txn->{buf}, length $txn->{$buf};	1311	sysread $txn->{fh}, $txn->{buf}, length $txn->{$buf};
824		1312
825	if (end-of-file or data complete) {	1313	if (end-of-file or data complete) {
826	$txn->{result} = $txn->{buf};	1314	$txn->{result} = $txn->{buf};
827	$txn->{finished}->broadcast;	1315	$txn->{finished}->send;
828	$txb->{cb}->($txn) of $txn->{cb}; # also call callback	1316	$txb->{cb}->($txn) of $txn->{cb}; # also call callback
829	}	1317	}
830		1318
831	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
832	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
833	data:	1321	data:
834		1322
835	$txn->{finished}->wait;	1323	$txn->{finished}->recv;
836	return $txn->{result};	1324	return $txn->{result};
837		1325
838	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)
839	that occured during request processing. The C<result> method detects	1327	that occurred during request processing. The C<result> method detects
840	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)
841	and just throws the exception, which means connection errors and other	1329	and just throws the exception, which means connection errors and other
842	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
843	random callback.	1331	random callback.
844		1332
…		…
875		1363
876	my $quit = AnyEvent->condvar;	1364	my $quit = AnyEvent->condvar;
877		1365
878	$fcp->txn_client_get ($url)->cb (sub {	1366	$fcp->txn_client_get ($url)->cb (sub {
879	...	1367	...
880	$quit->broadcast;	1368	$quit->send;
881	});	1369	});
882		1370
883	$quit->wait;	1371	$quit->recv;
884		1372
885		1373
886	=head1 BENCHMARK	1374	=head1 BENCHMARKS
887		1375
888	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
889	over the event loops themselves (and to give you an impression of the	1377	over the event loops themselves and to give you an impression of the speed
890	speed of various event loops), here is a benchmark of various supported	1378	of various event loops I prepared some benchmarks.
891	event models natively and with anyevent. The benchmark creates a lot of	1379
892	timers (with a zero timeout) and I/O watchers (watching STDOUT, a pty, to	1380	=head2 BENCHMARKING ANYEVENT OVERHEAD
		1381
		1382	Here is a benchmark of various supported event models used natively and
		1383	through AnyEvent. The benchmark creates a lot of timers (with a zero
		1384	timeout) and I/O watchers (watching STDOUT, a pty, to become writable,
893	become writable, which it is), lets them fire exactly once and destroys	1385	which it is), lets them fire exactly once and destroys them again.
894	them again.
895		1386
896	Rewriting the benchmark to use many different sockets instead of using	1387	Source code for this benchmark is found as F<eg/bench> in the AnyEvent
897	the same filehandle for all I/O watchers results in a much longer runtime	1388	distribution.
898	(socket creation is expensive), but qualitatively the same figures, so it
899	was not used.
900		1389
901	=head2 Explanation of the columns	1390	=head3 Explanation of the columns
902		1391
903	I<watcher> is the number of event watchers created/destroyed. Since	1392	I<watcher> is the number of event watchers created/destroyed. Since
904	different event models feature vastly different performances, each event	1393	different event models feature vastly different performances, each event
905	loop was given a number of watchers so that overall runtime is acceptable	1394	loop was given a number of watchers so that overall runtime is acceptable
906	and similar between tested event loop (and keep them from crashing): Glib	1395	and similar between tested event loop (and keep them from crashing): Glib
…		…
916	all watchers, to avoid adding memory overhead. That means closure creation	1405	all watchers, to avoid adding memory overhead. That means closure creation
917	and memory usage is not included in the figures.	1406	and memory usage is not included in the figures.
918		1407
919	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
920	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
921	invoked "watcher" times, it would C<< ->broadcast >> a condvar once to	1410	invoked "watcher" times, it would C<< ->send >> a condvar once to
922	signal the end of this phase.	1411	signal the end of this phase.
923		1412
924	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
925	watcher.	1414	watcher.
926		1415
927	=head2 Results	1416	=head3 Results
928		1417
929	name watchers bytes create invoke destroy comment	1418	name watchers bytes create invoke destroy comment
930	EV/EV 400000 244 0.56 0.46 0.31 EV native interface	1419	EV/EV 400000 244 0.56 0.46 0.31 EV native interface
931	EV/Any 100000 610 3.52 0.91 0.75 EV + AnyEvent watchers	1420	EV/Any 100000 244 2.50 0.46 0.29 EV + AnyEvent watchers
932	CoroEV/Any 100000 610 3.49 0.92 0.75 coroutines + Coro::Signal	1421	CoroEV/Any 100000 244 2.49 0.44 0.29 coroutines + Coro::Signal
933	Perl/Any 100000 513 4.91 0.92 1.15 pure perl implementation	1422	Perl/Any 100000 513 4.92 0.87 1.12 pure perl implementation
934	Event/Event 16000 523 28.05 21.38 0.86 Event native interface	1423	Event/Event 16000 516 31.88 31.30 0.85 Event native interface
935	Event/Any 16000 943 34.43 20.48 1.39 Event + AnyEvent watchers	1424	Event/Any 16000 590 35.75 31.42 1.08 Event + AnyEvent watchers
936	Glib/Any 16000 1357 96.99 12.55 55.51 quadratic behaviour	1425	Glib/Any 16000 1357 98.22 12.41 54.00 quadratic behaviour
937	Tk/Any 2000 1855 27.01 66.61 14.03 SEGV with >> 2000 watchers	1426	Tk/Any 2000 1860 26.97 67.98 14.00 SEGV with >> 2000 watchers
938	POE/Event 2000 6644 108.15 768.19 14.33 via POE::Loop::Event	1427	POE/Event 2000 6644 108.64 736.02 14.73 via POE::Loop::Event
939	POE/Select 2000 6343 94.69 807.65 562.69 via POE::Loop::Select	1428	POE/Select 2000 6343 94.13 809.12 565.96 via POE::Loop::Select
940		1429
941	=head2 Discussion	1430	=head3 Discussion
942		1431
943	The benchmark does I<not> measure scalability of the event loop very	1432	The benchmark does I<not> measure scalability of the event loop very
944	well. For example, a select-based event loop (such as the pure perl one)	1433	well. For example, a select-based event loop (such as the pure perl one)
945	can never compete with an event loop that uses epoll when the number of	1434	can never compete with an event loop that uses epoll when the number of
946	file descriptors grows high. In this benchmark, all events become ready at	1435	file descriptors grows high. In this benchmark, all events become ready at
947	the same time, so select/poll-based implementations get an unnatural speed	1436	the same time, so select/poll-based implementations get an unnatural speed
948	boost.	1437	boost.
949		1438
		1439	Also, note that the number of watchers usually has a nonlinear effect on
		1440	overall speed, that is, creating twice as many watchers doesn't take twice
		1441	the time - usually it takes longer. This puts event loops tested with a
		1442	higher number of watchers at a disadvantage.
		1443
		1444	To put the range of results into perspective, consider that on the
		1445	benchmark machine, handling an event takes roughly 1600 CPU cycles with
		1446	EV, 3100 CPU cycles with AnyEvent's pure perl loop and almost 3000000 CPU
		1447	cycles with POE.
		1448
950	C<EV> is the sole leader regarding speed and memory use, which are both	1449	C<EV> is the sole leader regarding speed and memory use, which are both
951	maximal/minimal, respectively. Even when going through AnyEvent, there are	1450	maximal/minimal, respectively. Even when going through AnyEvent, it uses
952	only two event loops that use slightly less memory (the C<Event> module	1451	far less memory than any other event loop and is still faster than Event
953	natively and the pure perl backend), and no faster event models, not even	1452	natively.
954	C<Event> natively.
955		1453
956	The pure perl implementation is hit in a few sweet spots (both the	1454	The pure perl implementation is hit in a few sweet spots (both the
957	zero timeout and the use of a single fd hit optimisations in the perl	1455	constant timeout and the use of a single fd hit optimisations in the perl
958	interpreter and the backend itself, and all watchers become ready at the	1456	interpreter and the backend itself). Nevertheless this shows that it
959	same time). Nevertheless this shows that it adds very little overhead in	1457	adds very little overhead in itself. Like any select-based backend its
960	itself. Like any select-based backend its performance becomes really bad	1458	performance becomes really bad with lots of file descriptors (and few of
961	with lots of file descriptors (and few of them active), of course, but	1459	them active), of course, but this was not subject of this benchmark.
962	this was not subject of this benchmark.
963		1460
964	The C<Event> module has a relatively high setup and callback invocation cost,	1461	The C<Event> module has a relatively high setup and callback invocation
965	but overall scores on the third place.	1462	cost, but overall scores in on the third place.
966		1463
967	C<Glib>'s memory usage is quite a bit bit higher, but it features a	1464	C<Glib>'s memory usage is quite a bit higher, but it features a
968	faster callback invocation and overall ends up in the same class as	1465	faster callback invocation and overall ends up in the same class as
969	C<Event>. However, Glib scales extremely badly, doubling the number of	1466	C<Event>. However, Glib scales extremely badly, doubling the number of
970	watchers increases the processing time by more than a factor of four,	1467	watchers increases the processing time by more than a factor of four,
971	making it completely unusable when using larger numbers of watchers	1468	making it completely unusable when using larger numbers of watchers
972	(note that only a single file descriptor was used in the benchmark, so	1469	(note that only a single file descriptor was used in the benchmark, so
…		…
975	The C<Tk> adaptor works relatively well. The fact that it crashes with	1472	The C<Tk> adaptor works relatively well. The fact that it crashes with
976	more than 2000 watchers is a big setback, however, as correctness takes	1473	more than 2000 watchers is a big setback, however, as correctness takes
977	precedence over speed. Nevertheless, its performance is surprising, as the	1474	precedence over speed. Nevertheless, its performance is surprising, as the
978	file descriptor is dup()ed for each watcher. This shows that the dup()	1475	file descriptor is dup()ed for each watcher. This shows that the dup()
979	employed by some adaptors is not a big performance issue (it does incur a	1476	employed by some adaptors is not a big performance issue (it does incur a
980	hidden memory cost inside the kernel, though, that is not reflected in the	1477	hidden memory cost inside the kernel which is not reflected in the figures
981	figures above).	1478	above).
982		1479
983	C<POE>, regardless of underlying event loop (wether using its pure perl	1480	C<POE>, regardless of underlying event loop (whether using its pure perl
984	select-based backend or the Event module) shows abysmal performance and	1481	select-based backend or the Event module, the POE-EV backend couldn't
		1482	be tested because it wasn't working) shows abysmal performance and
985	memory usage: Watchers use almost 30 times as much memory as EV watchers,	1483	memory usage with AnyEvent: Watchers use almost 30 times as much memory
986	and 10 times as much memory as both Event or EV via AnyEvent. Watcher	1484	as EV watchers, and 10 times as much memory as Event (the high memory
		1485	requirements are caused by requiring a session for each watcher). Watcher
987	invocation is almost 900 times slower than with AnyEvent's pure perl	1486	invocation speed is almost 900 times slower than with AnyEvent's pure perl
		1487	implementation.
		1488
988	implementation. The design of the POE adaptor class in AnyEvent can not	1489	The design of the POE adaptor class in AnyEvent can not really account
989	really account for this, as session creation overhead is small compared	1490	for the performance issues, though, as session creation overhead is
990	to execution of the state machine, which is coded pretty optimally within	1491	small compared to execution of the state machine, which is coded pretty
991	L<AnyEvent::Impl::POE>. POE simply seems to be abysmally slow.	1492	optimally within L<AnyEvent::Impl::POE> (and while everybody agrees that
		1493	using multiple sessions is not a good approach, especially regarding
		1494	memory usage, even the author of POE could not come up with a faster
		1495	design).
992		1496
993	=head2 Summary	1497	=head3 Summary
994		1498
		1499	=over 4
		1500
995	Using EV through AnyEvent is faster than any other event loop, but most	1501	=item * Using EV through AnyEvent is faster than any other event loop
996	event loops have acceptable performance with or without AnyEvent.	1502	(even when used without AnyEvent), but most event loops have acceptable
		1503	performance with or without AnyEvent.
997		1504
998	The overhead AnyEvent adds is usually much smaller than the overhead of	1505	=item * The overhead AnyEvent adds is usually much smaller than the overhead of
999	the actual event loop, only with extremely fast event loops such as the EV	1506	the actual event loop, only with extremely fast event loops such as EV
1000	adds AnyEvent significant overhead.	1507	adds AnyEvent significant overhead.
1001		1508
1002	And you should simply avoid POE like the plague if you want performance or	1509	=item * You should avoid POE like the plague if you want performance or
1003	reasonable memory usage.	1510	reasonable memory usage.
1004		1511
		1512	=back
		1513
		1514	=head2 BENCHMARKING THE LARGE SERVER CASE
		1515
		1516	This benchmark actually benchmarks the event loop itself. It works by
		1517	creating a number of "servers": each server consists of a socket pair, a
		1518	timeout watcher that gets reset on activity (but never fires), and an I/O
		1519	watcher waiting for input on one side of the socket. Each time the socket
		1520	watcher reads a byte it will write that byte to a random other "server".
		1521
		1522	The effect is that there will be a lot of I/O watchers, only part of which
		1523	are active at any one point (so there is a constant number of active
		1524	fds for each loop iteration, but which fds these are is random). The
		1525	timeout is reset each time something is read because that reflects how
		1526	most timeouts work (and puts extra pressure on the event loops).
		1527
		1528	In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100
		1529	(1%) are active. This mirrors the activity of large servers with many
		1530	connections, most of which are idle at any one point in time.
		1531
		1532	Source code for this benchmark is found as F<eg/bench2> in the AnyEvent
		1533	distribution.
		1534
		1535	=head3 Explanation of the columns
		1536
		1537	I<sockets> is the number of sockets, and twice the number of "servers" (as
		1538	each server has a read and write socket end).
		1539
		1540	I<create> is the time it takes to create a socket pair (which is
		1541	nontrivial) and two watchers: an I/O watcher and a timeout watcher.
		1542
		1543	I<request>, the most important value, is the time it takes to handle a
		1544	single "request", that is, reading the token from the pipe and forwarding
		1545	it to another server. This includes deleting the old timeout and creating
		1546	a new one that moves the timeout into the future.
		1547
		1548	=head3 Results
		1549
		1550	name sockets create request
		1551	EV 20000 69.01 11.16
		1552	Perl 20000 73.32 35.87
		1553	Event 20000 212.62 257.32
		1554	Glib 20000 651.16 1896.30
		1555	POE 20000 349.67 12317.24 uses POE::Loop::Event
		1556
		1557	=head3 Discussion
		1558
		1559	This benchmark I<does> measure scalability and overall performance of the
		1560	particular event loop.
		1561
		1562	EV is again fastest. Since it is using epoll on my system, the setup time
		1563	is relatively high, though.
		1564
		1565	Perl surprisingly comes second. It is much faster than the C-based event
		1566	loops Event and Glib.
		1567
		1568	Event suffers from high setup time as well (look at its code and you will
		1569	understand why). Callback invocation also has a high overhead compared to
		1570	the C<< $_->() for .. >>-style loop that the Perl event loop uses. Event
		1571	uses select or poll in basically all documented configurations.
		1572
		1573	Glib is hit hard by its quadratic behaviour w.r.t. many watchers. It
		1574	clearly fails to perform with many filehandles or in busy servers.
		1575
		1576	POE is still completely out of the picture, taking over 1000 times as long
		1577	as EV, and over 100 times as long as the Perl implementation, even though
		1578	it uses a C-based event loop in this case.
		1579
		1580	=head3 Summary
		1581
		1582	=over 4
		1583
		1584	=item * The pure perl implementation performs extremely well.
		1585
		1586	=item * Avoid Glib or POE in large projects where performance matters.
		1587
		1588	=back
		1589
		1590	=head2 BENCHMARKING SMALL SERVERS
		1591
		1592	While event loops should scale (and select-based ones do not...) even to
		1593	large servers, most programs we (or I :) actually write have only a few
		1594	I/O watchers.
		1595
		1596	In this benchmark, I use the same benchmark program as in the large server
		1597	case, but it uses only eight "servers", of which three are active at any
		1598	one time. This should reflect performance for a small server relatively
		1599	well.
		1600
		1601	The columns are identical to the previous table.
		1602
		1603	=head3 Results
		1604
		1605	name sockets create request
		1606	EV 16 20.00 6.54
		1607	Perl 16 25.75 12.62
		1608	Event 16 81.27 35.86
		1609	Glib 16 32.63 15.48
		1610	POE 16 261.87 276.28 uses POE::Loop::Event
		1611
		1612	=head3 Discussion
		1613
		1614	The benchmark tries to test the performance of a typical small
		1615	server. While knowing how various event loops perform is interesting, keep
		1616	in mind that their overhead in this case is usually not as important, due
		1617	to the small absolute number of watchers (that is, you need efficiency and
		1618	speed most when you have lots of watchers, not when you only have a few of
		1619	them).
		1620
		1621	EV is again fastest.
		1622
		1623	Perl again comes second. It is noticeably faster than the C-based event
		1624	loops Event and Glib, although the difference is too small to really
		1625	matter.
		1626
		1627	POE also performs much better in this case, but is is still far behind the
		1628	others.
		1629
		1630	=head3 Summary
		1631
		1632	=over 4
		1633
		1634	=item * C-based event loops perform very well with small number of
		1635	watchers, as the management overhead dominates.
		1636
		1637	=back
		1638
1005		1639
1006	=head1 FORK	1640	=head1 FORK
1007		1641
1008	Most event libraries are not fork-safe. The ones who are usually are	1642	Most event libraries are not fork-safe. The ones who are usually are
1009	because they are so inefficient. Only L<EV> is fully fork-aware.	1643	because they rely on inefficient but fork-safe C<select> or C<poll>
		1644	calls. Only L<EV> is fully fork-aware.
1010		1645
1011	If you have to fork, you must either do so I<before> creating your first	1646	If you have to fork, you must either do so I<before> creating your first
1012	watcher OR you must not use AnyEvent at all in the child.	1647	watcher OR you must not use AnyEvent at all in the child.
1013		1648
1014		1649
…		…
1026		1661
1027	BEGIN { delete $ENV{PERL_ANYEVENT_MODEL} }	1662	BEGIN { delete $ENV{PERL_ANYEVENT_MODEL} }
1028		1663
1029	use AnyEvent;	1664	use AnyEvent;
1030		1665
		1666	Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can
		1667	be used to probe what backend is used and gain other information (which is
		1668	probably even less useful to an attacker than PERL_ANYEVENT_MODEL).
		1669
1031		1670
1032	=head1 SEE ALSO	1671	=head1 SEE ALSO
1033		1672
1034	Event modules: L<Coro::EV>, L<EV>, L<EV::Glib>, L<Glib::EV>,	1673	Utility functions: L<AnyEvent::Util>.
1035	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>,
1036	L<Event::Lib>, L<Qt>, L<POE>.	1676	L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.
1037		1677
1038	Implementations: L<AnyEvent::Impl::CoroEV>, L<AnyEvent::Impl::EV>,	1678	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,
1039	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>,
1040	L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>, L<AnyEvent::Impl::EventLib>,	1680	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,
1041	L<AnyEvent::Impl::Qt>, L<AnyEvent::Impl::POE>.	1681	L<AnyEvent::Impl::POE>.
1042		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
1043	Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>.	1690	Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>, L<AnyEvent::DNS>.
1044		1691
1045		1692
1046	=head1 AUTHOR	1693	=head1 AUTHOR
1047		1694
1048	Marc Lehmann <schmorp@schmorp.de>	1695	Marc Lehmann <schmorp@schmorp.de>

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Comparing AnyEvent/lib/AnyEvent.pm (file contents): Revision 1.82 by root, Fri Apr 25 13:32:39 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 1.82 by root, Fri Apr 25 13:32:39 2008 UTC vs.
Revision 1.148 by root, Sat May 31 00:40:16 2008 UTC