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

Comparing AnyEvent/lib/AnyEvent.pm (file contents):
Revision 1.83 by root, Fri Apr 25 13:39:08 2008 UTC vs.
Revision 1.143 by root, Wed May 28 23:57:38 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		22
23	=head1 WHY YOU SHOULD USE THIS MODULE (OR NOT)	23	=head1 WHY YOU SHOULD USE THIS MODULE (OR NOT)
24		24
25	Glib, POE, IO::Async, Event... CPAN offers event models by the dozen	25	Glib, POE, IO::Async, Event... CPAN offers event models by the dozen
26	nowadays. So what is different about AnyEvent?	26	nowadays. So what is different about AnyEvent?
…		…
48	isn't itself. What's worse, all the potential users of your module are	48	isn't itself. What's worse, all the potential users of your module are
49	I<also> forced to use the same event loop you use.	49	I<also> forced to use the same event loop you use.
50		50
51	AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works	51	AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works
52	fine. AnyEvent + Tk works fine etc. etc. but none of these work together	52	fine. AnyEvent + Tk works fine etc. etc. but none of these work together
53	with the rest: POE + IO::Async? no go. Tk + Event? no go. Again: if	53	with the rest: POE + IO::Async? No go. Tk + Event? No go. Again: if
54	your module uses one of those, every user of your module has to use it,	54	your module uses one of those, every user of your module has to use it,
55	too. But if your module uses AnyEvent, it works transparently with all	55	too. But if your module uses AnyEvent, it works transparently with all
56	event models it supports (including stuff like POE and IO::Async, as long	56	event models it supports (including stuff like POE and IO::Async, as long
57	as those use one of the supported event loops. It is trivial to add new	57	as those use one of the supported event loops. It is trivial to add new
58	event loops to AnyEvent, too, so it is future-proof).	58	event loops to AnyEvent, too, so it is future-proof).
59		59
60	In addition to being free of having to use I<the one and only true event	60	In addition to being free of having to use I<the one and only true event
61	model>, AnyEvent also is free of bloat and policy: with POE or similar	61	model>, AnyEvent also is free of bloat and policy: with POE or similar
62	modules, you get an enourmous amount of code and strict rules you have to	62	modules, you get an enormous amount of code and strict rules you have to
63	follow. AnyEvent, on the other hand, is lean and up to the point, by only	63	follow. AnyEvent, on the other hand, is lean and up to the point, by only
64	offering the functionality that is necessary, in as thin as a wrapper as	64	offering the functionality that is necessary, in as thin as a wrapper as
65	technically possible.	65	technically possible.
66		66
		67	Of course, AnyEvent comes with a big (and fully optional!) toolbox
		68	of useful functionality, such as an asynchronous DNS resolver, 100%
		69	non-blocking connects (even with TLS/SSL, IPv6 and on broken platforms
		70	such as Windows) and lots of real-world knowledge and workarounds for
		71	platform bugs and differences.
		72
67	Of course, if you want lots of policy (this can arguably be somewhat	73	Now, if you I<do want> lots of policy (this can arguably be somewhat
68	useful) and you want to force your users to use the one and only event	74	useful) and you want to force your users to use the one and only event
69	model, you should I<not> use this module.	75	model, you should I<not> use this module.
70
71		76
72	=head1 DESCRIPTION	77	=head1 DESCRIPTION
73		78
74	L<AnyEvent> provides an identical interface to multiple event loops. This	79	L<AnyEvent> provides an identical interface to multiple event loops. This
75	allows module authors to utilise an event loop without forcing module	80	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>	84	The interface itself is vaguely similar, but not identical to the L<Event>
80	module.	85	module.
81		86
82	During the first call of any watcher-creation method, the module tries	87	During the first call of any watcher-creation method, the module tries
83	to detect the currently loaded event loop by probing whether one of the	88	to detect the currently loaded event loop by probing whether one of the
84	following modules is already loaded: L<Coro::EV>, L<Coro::Event>, L<EV>,	89	following modules is already loaded: L<EV>,
85	L<Event>, L<Glib>, L<AnyEvent::Impl::Perl>, L<Tk>, L<Event::Lib>, L<Qt>,	90	L<Event>, L<Glib>, L<AnyEvent::Impl::Perl>, L<Tk>, L<Event::Lib>, L<Qt>,
86	L<POE>. The first one found is used. If none are found, the module tries	91	L<POE>. The first one found is used. If none are found, the module tries
87	to load these modules (excluding Tk, Event::Lib, Qt and POE as the pure perl	92	to load these modules (excluding Tk, Event::Lib, Qt and POE as the pure perl
88	adaptor should always succeed) in the order given. The first one that can	93	adaptor should always succeed) in the order given. The first one that can
89	be successfully loaded will be used. If, after this, still none could be	94	be successfully loaded will be used. If, after this, still none could be
…		…
103	starts using it, all bets are off. Maybe you should tell their authors to	108	starts using it, all bets are off. Maybe you should tell their authors to
104	use AnyEvent so their modules work together with others seamlessly...	109	use AnyEvent so their modules work together with others seamlessly...
105		110
106	The pure-perl implementation of AnyEvent is called	111	The pure-perl implementation of AnyEvent is called
107	C<AnyEvent::Impl::Perl>. Like other event modules you can load it	112	C<AnyEvent::Impl::Perl>. Like other event modules you can load it
108	explicitly.	113	explicitly and enjoy the high availability of that event loop :)
109		114
110	=head1 WATCHERS	115	=head1 WATCHERS
111		116
112	AnyEvent has the central concept of a I<watcher>, which is an object that	117	AnyEvent has the central concept of a I<watcher>, which is an object that
113	stores relevant data for each kind of event you are waiting for, such as	118	stores relevant data for each kind of event you are waiting for, such as
114	the callback to call, the filehandle to watch, etc.	119	the callback to call, the file handle to watch, etc.
115		120
116	These watchers are normal Perl objects with normal Perl lifetime. After	121	These watchers are normal Perl objects with normal Perl lifetime. After
117	creating a watcher it will immediately "watch" for events and invoke the	122	creating a watcher it will immediately "watch" for events and invoke the
118	callback when the event occurs (of course, only when the event model	123	callback when the event occurs (of course, only when the event model
119	is in control).	124	is in control).
…		…
141	=head2 I/O WATCHERS	146	=head2 I/O WATCHERS
142		147
143	You can create an I/O watcher by calling the C<< AnyEvent->io >> method	148	You can create an I/O watcher by calling the C<< AnyEvent->io >> method
144	with the following mandatory key-value pairs as arguments:	149	with the following mandatory key-value pairs as arguments:
145		150
146	C<fh> the Perl I<file handle> (I<not> file descriptor) to watch for	151	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	152	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,	153	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	154	respectively. C<cb> is the callback to invoke each time the file handle
150	becomes ready.	155	becomes ready.
151		156
		157	Although the callback might get passed parameters, their value and
		158	presence is undefined and you cannot rely on them. Portable AnyEvent
		159	callbacks cannot use arguments passed to I/O watcher callbacks.
		160
152	The I/O watcher might use the underlying file descriptor or a copy of it.	161	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	162	You must not close a file handle as long as any watcher is active on the
154	on the underlying file descriptor.	163	underlying file descriptor.
155		164
156	Some event loops issue spurious readyness notifications, so you should	165	Some event loops issue spurious readyness notifications, so you should
157	always use non-blocking calls when reading/writing from/to your file	166	always use non-blocking calls when reading/writing from/to your file
158	handles.	167	handles.
159		168
…		…
170		179
171	You can create a time watcher by calling the C<< AnyEvent->timer >>	180	You can create a time watcher by calling the C<< AnyEvent->timer >>
172	method with the following mandatory arguments:	181	method with the following mandatory arguments:
173		182
174	C<after> specifies after how many seconds (fractional values are	183	C<after> specifies after how many seconds (fractional values are
175	supported) should the timer activate. C<cb> the callback to invoke in that	184	supported) the callback should be invoked. C<cb> is the callback to invoke
176	case.	185	in that case.
		186
		187	Although the callback might get passed parameters, their value and
		188	presence is undefined and you cannot rely on them. Portable AnyEvent
		189	callbacks cannot use arguments passed to time watcher callbacks.
177		190
178	The timer callback will be invoked at most once: if you want a repeating	191	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	192	timer you have to create a new watcher (this is a limitation by both Tk
180	and Glib).	193	and Glib).
181		194
…		…
220	timers.	233	timers.
221		234
222	AnyEvent always prefers relative timers, if available, matching the	235	AnyEvent always prefers relative timers, if available, matching the
223	AnyEvent API.	236	AnyEvent API.
224		237
		238	AnyEvent has two additional methods that return the "current time":
		239
		240	=over 4
		241
		242	=item AnyEvent->time
		243
		244	This returns the "current wallclock time" as a fractional number of
		245	seconds since the Epoch (the same thing as C<time> or C<Time::HiRes::time>
		246	return, and the result is guaranteed to be compatible with those).
		247
		248	It progresses independently of any event loop processing.
		249
		250	In almost all cases (in all cases if you don't care), this is the function
		251	to call when you want to know the current time.
		252
		253	=item AnyEvent->now
		254
		255	This also returns the "current wallclock time", but unlike C<time>, above,
		256	this value might change only once per event loop iteration, depending on
		257	the event loop (most return the same time as C<time>, above). This is the
		258	time that AnyEvent timers get scheduled against.
		259
		260	For a practical example of when these times differ, consider L<Event::Lib>
		261	and L<EV> and the following set-up:
		262
		263	The event loop is running and has just invoked one of your callback at
		264	time=500 (assume no other callbacks delay processing). In your callback,
		265	you wait a second by executing C<sleep 1> (blocking the process for a
		266	second) and then (at time=501) you create a relative timer that fires
		267	after three seconds.
		268
		269	With L<Event::Lib>, C<< AnyEvent->time >> and C<< AnyEvent->now >> will
		270	both return C<501>, because that is the current time, and the timer will
		271	be scheduled to fire at time=504 (C<501> + C<3>).
		272
		273	With L<EV>m C<< AnyEvent->time >> returns C<501> (as that is the current
		274	time), but C<< AnyEvent->now >> returns C<500>, as that is the time the
		275	last event processing phase started. With L<EV>, your timer gets scheduled
		276	to run at time=503 (C<500> + C<3>).
		277
		278	In one sense, L<Event::Lib> is more exact, as it uses the current time
		279	regardless of any delays introduced by event processing. However, most
		280	callbacks do not expect large delays in processing, so this causes a
		281	higher drift (and a lot more syscalls to get the current time).
		282
		283	In another sense, L<EV> is more exact, as your timer will be scheduled at
		284	the same time, regardless of how long event processing actually took.
		285
		286	In either case, if you care (and in most cases, you don't), then you
		287	can get whatever behaviour you want with any event loop, by taking the
		288	difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into
		289	account.
		290
		291	=back
		292
225	=head2 SIGNAL WATCHERS	293	=head2 SIGNAL WATCHERS
226		294
227	You can watch for signals using a signal watcher, C<signal> is the signal	295	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	296	I<name> without any C<SIG> prefix, C<cb> is the Perl callback to
229	be invoked whenever a signal occurs.	297	be invoked whenever a signal occurs.
230		298
		299	Although the callback might get passed parameters, their value and
		300	presence is undefined and you cannot rely on them. Portable AnyEvent
		301	callbacks cannot use arguments passed to signal watcher callbacks.
		302
231	Multiple signal occurances can be clumped together into one callback	303	Multiple signal occurrences can be clumped together into one callback
232	invocation, and callback invocation will be synchronous. synchronous means	304	invocation, and callback invocation will be synchronous. Synchronous means
233	that it might take a while until the signal gets handled by the process,	305	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.	306	but it is guaranteed not to interrupt any other callbacks.
235		307
236	The main advantage of using these watchers is that you can share a signal	308	The main advantage of using these watchers is that you can share a signal
237	between multiple watchers.	309	between multiple watchers.
238		310
239	This watcher might use C<%SIG>, so programs overwriting those signals	311	This watcher might use C<%SIG>, so programs overwriting those signals
…		…
249		321
250	The child process is specified by the C<pid> argument (if set to C<0>, it	322	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	323	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	324	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	325	signal handler for C<SIGCHLD>. The callback will be called with the pid
254	and exit status (as returned by waitpid).	326	and exit status (as returned by waitpid), so unlike other watcher types,
		327	you I<can> rely on child watcher callback arguments.
255		328
256	There is a slight catch to child watchers, however: you usually start them	329	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	330	I<after> the child process was created, and this means the process could
258	have exited already (and no SIGCHLD will be sent anymore).	331	have exited already (and no SIGCHLD will be sent anymore).
259		332
…		…
266	C<fork> the child (alternatively, you can call C<AnyEvent::detect>).	339	C<fork> the child (alternatively, you can call C<AnyEvent::detect>).
267		340
268	Example: fork a process and wait for it	341	Example: fork a process and wait for it
269		342
270	my $done = AnyEvent->condvar;	343	my $done = AnyEvent->condvar;
271
272	AnyEvent::detect; # force event module to be initialised
273		344
274	my $pid = fork or exit 5;	345	my $pid = fork or exit 5;
275		346
276	my $w = AnyEvent->child (	347	my $w = AnyEvent->child (
277	pid => $pid,	348	pid => $pid,
278	cb => sub {	349	cb => sub {
279	my ($pid, $status) = @_;	350	my ($pid, $status) = @_;
280	warn "pid $pid exited with status $status";	351	warn "pid $pid exited with status $status";
281	$done->broadcast;	352	$done->send;
282	},	353	},
283	);	354	);
284		355
285	# do something else, then wait for process exit	356	# do something else, then wait for process exit
286	$done->wait;	357	$done->recv;
287		358
288	=head2 CONDITION VARIABLES	359	=head2 CONDITION VARIABLES
289		360
		361	If you are familiar with some event loops you will know that all of them
		362	require you to run some blocking "loop", "run" or similar function that
		363	will actively watch for new events and call your callbacks.
		364
		365	AnyEvent is different, it expects somebody else to run the event loop and
		366	will only block when necessary (usually when told by the user).
		367
		368	The instrument to do that is called a "condition variable", so called
		369	because they represent a condition that must become true.
		370
290	Condition variables can be created by calling the C<< AnyEvent->condvar >>	371	Condition variables can be created by calling the C<< AnyEvent->condvar
291	method without any arguments.	372	>> method, usually without arguments. The only argument pair allowed is
		373	C<cb>, which specifies a callback to be called when the condition variable
		374	becomes true.
292		375
293	A condition variable waits for a condition - precisely that the C<<	376	After creation, the condition variable is "false" until it becomes "true"
294	->broadcast >> method has been called.	377	by calling the C<send> method (or calling the condition variable as if it
		378	were a callback, read about the caveats in the description for the C<<
		379	->send >> method).
295		380
296	They are very useful to signal that a condition has been fulfilled, for	381	Condition variables are similar to callbacks, except that you can
		382	optionally wait for them. They can also be called merge points - points
		383	in time where multiple outstanding events have been processed. And yet
		384	another way to call them is transactions - each condition variable can be
		385	used to represent a transaction, which finishes at some point and delivers
		386	a result.
		387
		388	Condition variables are very useful to signal that something has finished,
297	example, if you write a module that does asynchronous http requests,	389	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	390	then a condition variable would be the ideal candidate to signal the
299	availability of results.	391	availability of results. The user can either act when the callback is
		392	called or can synchronously C<< ->recv >> for the results.
300		393
301	You can also use condition variables to block your main program until	394	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	395	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<<	396	could C<< ->recv >> in your main program until the user clicks the Quit
304	->broadcast >> the "quit" event.	397	button of your app, which would C<< ->send >> the "quit" event.
305		398
306	Note that condition variables recurse into the event loop - if you have	399	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	400	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	401	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,	402	you should avoid making a blocking wait yourself, at least in callbacks,
310	as this asks for trouble.	403	as this asks for trouble.
311		404
312	This object has two methods:	405	Condition variables are represented by hash refs in perl, and the keys
		406	used by AnyEvent itself are all named C<_ae_XXX> to make subclassing
		407	easy (it is often useful to build your own transaction class on top of
		408	AnyEvent). To subclass, use C<AnyEvent::CondVar> as base class and call
		409	it's C<new> method in your own C<new> method.
		410
		411	There are two "sides" to a condition variable - the "producer side" which
		412	eventually calls C<< -> send >>, and the "consumer side", which waits
		413	for the send to occur.
		414
		415	Example: wait for a timer.
		416
		417	# wait till the result is ready
		418	my $result_ready = AnyEvent->condvar;
		419
		420	# do something such as adding a timer
		421	# or socket watcher the calls $result_ready->send
		422	# when the "result" is ready.
		423	# in this case, we simply use a timer:
		424	my $w = AnyEvent->timer (
		425	after => 1,
		426	cb => sub { $result_ready->send },
		427	);
		428
		429	# this "blocks" (while handling events) till the callback
		430	# calls send
		431	$result_ready->recv;
		432
		433	Example: wait for a timer, but take advantage of the fact that
		434	condition variables are also code references.
		435
		436	my $done = AnyEvent->condvar;
		437	my $delay = AnyEvent->timer (after => 5, cb => $done);
		438	$done->recv;
		439
		440	=head3 METHODS FOR PRODUCERS
		441
		442	These methods should only be used by the producing side, i.e. the
		443	code/module that eventually sends the signal. Note that it is also
		444	the producer side which creates the condvar in most cases, but it isn't
		445	uncommon for the consumer to create it as well.
313		446
314	=over 4	447	=over 4
315		448
		449	=item $cv->send (...)
		450
		451	Flag the condition as ready - a running C<< ->recv >> and all further
		452	calls to C<recv> will (eventually) return after this method has been
		453	called. If nobody is waiting the send will be remembered.
		454
		455	If a callback has been set on the condition variable, it is called
		456	immediately from within send.
		457
		458	Any arguments passed to the C<send> call will be returned by all
		459	future C<< ->recv >> calls.
		460
		461	Condition variables are overloaded so one can call them directly
		462	(as a code reference). Calling them directly is the same as calling
		463	C<send>. Note, however, that many C-based event loops do not handle
		464	overloading, so as tempting as it may be, passing a condition variable
		465	instead of a callback does not work. Both the pure perl and EV loops
		466	support overloading, however, as well as all functions that use perl to
		467	invoke a callback (as in L<AnyEvent::Socket> and L<AnyEvent::DNS> for
		468	example).
		469
		470	=item $cv->croak ($error)
		471
		472	Similar to send, but causes all call's to C<< ->recv >> to invoke
		473	C<Carp::croak> with the given error message/object/scalar.
		474
		475	This can be used to signal any errors to the condition variable
		476	user/consumer.
		477
		478	=item $cv->begin ([group callback])
		479
316	=item $cv->wait	480	=item $cv->end
317		481
318	Wait (blocking if necessary) until the C<< ->broadcast >> method has been	482	These two methods are EXPERIMENTAL and MIGHT CHANGE.
		483
		484	These two methods can be used to combine many transactions/events into
		485	one. For example, a function that pings many hosts in parallel might want
		486	to use a condition variable for the whole process.
		487
		488	Every call to C<< ->begin >> will increment a counter, and every call to
		489	C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end
		490	>>, the (last) callback passed to C<begin> will be executed. That callback
		491	is I<supposed> to call C<< ->send >>, but that is not required. If no
		492	callback was set, C<send> will be called without any arguments.
		493
		494	Let's clarify this with the ping example:
		495
		496	my $cv = AnyEvent->condvar;
		497
		498	my %result;
		499	$cv->begin (sub { $cv->send (\%result) });
		500
		501	for my $host (@list_of_hosts) {
		502	$cv->begin;
		503	ping_host_then_call_callback $host, sub {
		504	$result{$host} = ...;
		505	$cv->end;
		506	};
		507	}
		508
		509	$cv->end;
		510
		511	This code fragment supposedly pings a number of hosts and calls
		512	C<send> after results for all then have have been gathered - in any
		513	order. To achieve this, the code issues a call to C<begin> when it starts
		514	each ping request and calls C<end> when it has received some result for
		515	it. Since C<begin> and C<end> only maintain a counter, the order in which
		516	results arrive is not relevant.
		517
		518	There is an additional bracketing call to C<begin> and C<end> outside the
		519	loop, which serves two important purposes: first, it sets the callback
		520	to be called once the counter reaches C<0>, and second, it ensures that
		521	C<send> is called even when C<no> hosts are being pinged (the loop
		522	doesn't execute once).
		523
		524	This is the general pattern when you "fan out" into multiple subrequests:
		525	use an outer C<begin>/C<end> pair to set the callback and ensure C<end>
		526	is called at least once, and then, for each subrequest you start, call
		527	C<begin> and for each subrequest you finish, call C<end>.
		528
		529	=back
		530
		531	=head3 METHODS FOR CONSUMERS
		532
		533	These methods should only be used by the consuming side, i.e. the
		534	code awaits the condition.
		535
		536	=over 4
		537
		538	=item $cv->recv
		539
		540	Wait (blocking if necessary) until the C<< ->send >> or C<< ->croak
319	called on c<$cv>, while servicing other watchers normally.	541	>> methods have been called on c<$cv>, while servicing other watchers
		542	normally.
320		543
321	You can only wait once on a condition - additional calls will return	544	You can only wait once on a condition - additional calls are valid but
322	immediately.	545	will return immediately.
		546
		547	If an error condition has been set by calling C<< ->croak >>, then this
		548	function will call C<croak>.
		549
		550	In list context, all parameters passed to C<send> will be returned,
		551	in scalar context only the first one will be returned.
323		552
324	Not all event models support a blocking wait - some die in that case	553	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	554	(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	555	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	556	caller decide whether the call will block or not (for example, by coupling
328	condition variables with some kind of request results and supporting	557	condition variables with some kind of request results and supporting
329	callbacks so the caller knows that getting the result will not block,	558	callbacks so the caller knows that getting the result will not block,
330	while still suppporting blocking waits if the caller so desires).	559	while still supporting blocking waits if the caller so desires).
331		560
332	Another reason I<never> to C<< ->wait >> in a module is that you cannot	561	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	562	sensibly have two C<< ->recv >>'s in parallel, as that would require
334	multiple interpreters or coroutines/threads, none of which C<AnyEvent>	563	multiple interpreters or coroutines/threads, none of which C<AnyEvent>
335	can supply (the coroutine-aware backends L<AnyEvent::Impl::CoroEV> and	564	can supply.
336	L<AnyEvent::Impl::CoroEvent> explicitly support concurrent C<< ->wait >>'s
337	from different coroutines, however).
338		565
339	=item $cv->broadcast	566	The L<Coro> module, however, I<can> and I<does> supply coroutines and, in
		567	fact, L<Coro::AnyEvent> replaces AnyEvent's condvars by coroutine-safe
		568	versions and also integrates coroutines into AnyEvent, making blocking
		569	C<< ->recv >> calls perfectly safe as long as they are done from another
		570	coroutine (one that doesn't run the event loop).
340		571
341	Flag the condition as ready - a running C<< ->wait >> and all further	572	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	573	only calling C<< ->recv >> from within that callback (or at a later
343	called. If nobody is waiting the broadcast will be remembered..	574	time). This will work even when the event loop does not support blocking
		575	waits otherwise.
		576
		577	=item $bool = $cv->ready
		578
		579	Returns true when the condition is "true", i.e. whether C<send> or
		580	C<croak> have been called.
		581
		582	=item $cb = $cv->cb ([new callback])
		583
		584	This is a mutator function that returns the callback set and optionally
		585	replaces it before doing so.
		586
		587	The callback will be called when the condition becomes "true", i.e. when
		588	C<send> or C<croak> are called. Calling C<recv> inside the callback
		589	or at any later time is guaranteed not to block.
344		590
345	=back	591	=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	$result_ready->wait;
364		592
365	=head1 GLOBAL VARIABLES AND FUNCTIONS	593	=head1 GLOBAL VARIABLES AND FUNCTIONS
366		594
367	=over 4	595	=over 4
368		596
…		…
374	C<AnyEvent::Impl:xxx> modules, but can be any other class in the case	602	C<AnyEvent::Impl:xxx> modules, but can be any other class in the case
375	AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode>).	603	AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode>).
376		604
377	The known classes so far are:	605	The known classes so far are:
378		606
379	AnyEvent::Impl::CoroEV based on Coro::EV, best choice.
380	AnyEvent::Impl::CoroEvent based on Coro::Event, second best choice.
381	AnyEvent::Impl::EV based on EV (an interface to libev, best choice).	607	AnyEvent::Impl::EV based on EV (an interface to libev, best choice).
382	AnyEvent::Impl::Event based on Event, second best choice.	608	AnyEvent::Impl::Event based on Event, second best choice.
		609	AnyEvent::Impl::Perl pure-perl implementation, fast and portable.
383	AnyEvent::Impl::Glib based on Glib, third-best choice.	610	AnyEvent::Impl::Glib based on Glib, third-best choice.
384	AnyEvent::Impl::Perl pure-perl implementation, inefficient but portable.
385	AnyEvent::Impl::Tk based on Tk, very bad choice.	611	AnyEvent::Impl::Tk based on Tk, very bad choice.
386	AnyEvent::Impl::Qt based on Qt, cannot be autoprobed (see its docs).	612	AnyEvent::Impl::Qt based on Qt, cannot be autoprobed (see its docs).
387	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.	613	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
388	AnyEvent::Impl::POE based on POE, not generic enough for full support.	614	AnyEvent::Impl::POE based on POE, not generic enough for full support.
389		615
…		…
402	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model	628	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model
403	if necessary. You should only call this function right before you would	629	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	630	have created an AnyEvent watcher anyway, that is, as late as possible at
405	runtime.	631	runtime.
406		632
		633	=item $guard = AnyEvent::post_detect { BLOCK }
		634
		635	Arranges for the code block to be executed as soon as the event model is
		636	autodetected (or immediately if this has already happened).
		637
		638	If called in scalar or list context, then it creates and returns an object
		639	that automatically removes the callback again when it is destroyed. See
		640	L<Coro::BDB> for a case where this is useful.
		641
		642	=item @AnyEvent::post_detect
		643
		644	If there are any code references in this array (you can C<push> to it
		645	before or after loading AnyEvent), then they will called directly after
		646	the event loop has been chosen.
		647
		648	You should check C<$AnyEvent::MODEL> before adding to this array, though:
		649	if it contains a true value then the event loop has already been detected,
		650	and the array will be ignored.
		651
		652	Best use C<AnyEvent::post_detect { BLOCK }> instead.
		653
407	=back	654	=back
408		655
409	=head1 WHAT TO DO IN A MODULE	656	=head1 WHAT TO DO IN A MODULE
410		657
411	As a module author, you should C<use AnyEvent> and call AnyEvent methods	658	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	661	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	662	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	663	by calling AnyEvent in your module body you force the user of your module
417	to load the event module first.	664	to load the event module first.
418		665
419	Never call C<< ->wait >> on a condition variable unless you I<know> that	666	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	667	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	668	because it will stall the whole program, and the whole point of using
422	events is to stay interactive.	669	events is to stay interactive.
423		670
424	It is fine, however, to call C<< ->wait >> when the user of your module	671	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	672	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 >>	673	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).	674	freely, as the user of your module knows what she is doing. always).
428		675
429	=head1 WHAT TO DO IN THE MAIN PROGRAM	676	=head1 WHAT TO DO IN THE MAIN PROGRAM
430		677
431	There will always be a single main program - the only place that should	678	There will always be a single main program - the only place that should
…		…
433		680
434	If it doesn't care, it can just "use AnyEvent" and use it itself, or not	681	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	682	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.	683	decide which implementation to chose if some module relies on it.
437		684
438	If the main program relies on a specific event model. For example, in	685	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	686	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	687	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	688	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	689	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	690	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.	691	might chose the wrong one unless you load the correct one yourself.
445		692
446	You can chose to use a rather inefficient pure-perl implementation by	693	You can chose to use a pure-perl implementation by loading the
447	loading the C<AnyEvent::Impl::Perl> module, which gives you similar	694	C<AnyEvent::Impl::Perl> module, which gives you similar behaviour
448	behaviour everywhere, but letting AnyEvent chose is generally better.	695	everywhere, but letting AnyEvent chose the model is generally better.
		696
		697	=head2 MAINLOOP EMULATION
		698
		699	Sometimes (often for short test scripts, or even standalone programs who
		700	only want to use AnyEvent), you do not want to run a specific event loop.
		701
		702	In that case, you can use a condition variable like this:
		703
		704	AnyEvent->condvar->recv;
		705
		706	This has the effect of entering the event loop and looping forever.
		707
		708	Note that usually your program has some exit condition, in which case
		709	it is better to use the "traditional" approach of storing a condition
		710	variable somewhere, waiting for it, and sending it when the program should
		711	exit cleanly.
		712
		713
		714	=head1 OTHER MODULES
		715
		716	The following is a non-exhaustive list of additional modules that use
		717	AnyEvent and can therefore be mixed easily with other AnyEvent modules
		718	in the same program. Some of the modules come with AnyEvent, some are
		719	available via CPAN.
		720
		721	=over 4
		722
		723	=item L<AnyEvent::Util>
		724
		725	Contains various utility functions that replace often-used but blocking
		726	functions such as C<inet_aton> by event-/callback-based versions.
		727
		728	=item L<AnyEvent::Handle>
		729
		730	Provide read and write buffers and manages watchers for reads and writes.
		731
		732	=item L<AnyEvent::Socket>
		733
		734	Provides various utility functions for (internet protocol) sockets,
		735	addresses and name resolution. Also functions to create non-blocking tcp
		736	connections or tcp servers, with IPv6 and SRV record support and more.
		737
		738	=item L<AnyEvent::DNS>
		739
		740	Provides rich asynchronous DNS resolver capabilities.
		741
		742	=item L<AnyEvent::HTTPD>
		743
		744	Provides a simple web application server framework.
		745
		746	=item L<AnyEvent::FastPing>
		747
		748	The fastest ping in the west.
		749
		750	=item L<Net::IRC3>
		751
		752	AnyEvent based IRC client module family.
		753
		754	=item L<Net::XMPP2>
		755
		756	AnyEvent based XMPP (Jabber protocol) module family.
		757
		758	=item L<Net::FCP>
		759
		760	AnyEvent-based implementation of the Freenet Client Protocol, birthplace
		761	of AnyEvent.
		762
		763	=item L<Event::ExecFlow>
		764
		765	High level API for event-based execution flow control.
		766
		767	=item L<Coro>
		768
		769	Has special support for AnyEvent via L<Coro::AnyEvent>.
		770
		771	=item L<AnyEvent::AIO>, L<IO::AIO>
		772
		773	Truly asynchronous I/O, should be in the toolbox of every event
		774	programmer. AnyEvent::AIO transparently fuses IO::AIO and AnyEvent
		775	together.
		776
		777	=item L<AnyEvent::BDB>, L<BDB>
		778
		779	Truly asynchronous Berkeley DB access. AnyEvent::AIO transparently fuses
		780	IO::AIO and AnyEvent together.
		781
		782	=item L<IO::Lambda>
		783
		784	The lambda approach to I/O - don't ask, look there. Can use AnyEvent.
		785
		786	=back
449		787
450	=cut	788	=cut
451		789
452	package AnyEvent;	790	package AnyEvent;
453		791
454	no warnings;	792	no warnings;
455	use strict;	793	use strict;
456		794
457	use Carp;	795	use Carp;
458		796
459	our $VERSION = '3.3';	797	our $VERSION = '4.05';
460	our $MODEL;	798	our $MODEL;
461		799
462	our $AUTOLOAD;	800	our $AUTOLOAD;
463	our @ISA;	801	our @ISA;
464		802
		803	our @REGISTRY;
		804
		805	our $WIN32;
		806
		807	BEGIN {
		808	my $win32 = ! ! ($^O =~ /mswin32/i);
		809	eval "sub WIN32(){ $win32 }";
		810	}
		811
465	our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1;	812	our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1;
466		813
467	our @REGISTRY;	814	our %PROTOCOL; # (ipv4\|ipv6) => (1\|2), higher numbers are preferred
		815
		816	{
		817	my $idx;
		818	$PROTOCOL{$_} = ++$idx
		819	for reverse split /\s,\s/,
		820	$ENV{PERL_ANYEVENT_PROTOCOLS} \|\| "ipv4,ipv6";
		821	}
468		822
469	my @models = (	823	my @models = (
470	[Coro::EV:: => AnyEvent::Impl::CoroEV::],
471	[Coro::Event:: => AnyEvent::Impl::CoroEvent::],
472	[EV:: => AnyEvent::Impl::EV::],	824	[EV:: => AnyEvent::Impl::EV::],
473	[Event:: => AnyEvent::Impl::Event::],	825	[Event:: => AnyEvent::Impl::Event::],
474	[Glib:: => AnyEvent::Impl::Glib::],
475	[Tk:: => AnyEvent::Impl::Tk::],
476	[Wx:: => AnyEvent::Impl::POE::],
477	[Prima:: => AnyEvent::Impl::POE::],
478	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::],	826	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::],
479	# everything below here will not be autoprobed as the pureperl backend should work everywhere	827	# everything below here will not be autoprobed
		828	# as the pureperl backend should work everywhere
		829	# and is usually faster
		830	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
		831	[Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers
480	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy	832	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
481	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program	833	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program
482	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza	834	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
		835	[Wx:: => AnyEvent::Impl::POE::],
		836	[Prima:: => AnyEvent::Impl::POE::],
483	);	837	);
484		838
485	our %method = map +($_ => 1), qw(io timer signal child condvar broadcast wait one_event DESTROY);	839	our %method = map +($_ => 1), qw(io timer time now signal child condvar one_event DESTROY);
		840
		841	our @post_detect;
		842
		843	sub post_detect(&) {
		844	my ($cb) = @_;
		845
		846	if ($MODEL) {
		847	$cb->();
		848
		849	1
		850	} else {
		851	push @post_detect, $cb;
		852
		853	defined wantarray
		854	? bless \$cb, "AnyEvent::Util::PostDetect"
		855	: ()
		856	}
		857	}
		858
		859	sub AnyEvent::Util::PostDetect::DESTROY {
		860	@post_detect = grep $_ != ${$_[0]}, @post_detect;
		861	}
486		862
487	sub detect() {	863	sub detect() {
488	unless ($MODEL) {	864	unless ($MODEL) {
489	no strict 'refs';	865	no strict 'refs';
		866	local $SIG{__DIE__};
490		867
491	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {	868	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {
492	my $model = "AnyEvent::Impl::$1";	869	my $model = "AnyEvent::Impl::$1";
493	if (eval "require $model") {	870	if (eval "require $model") {
494	$MODEL = $model;	871	$MODEL = $model;
…		…
524	last;	901	last;
525	}	902	}
526	}	903	}
527		904
528	$MODEL	905	$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.";	906	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.";
530	}	907	}
531	}	908	}
532		909
533	unshift @ISA, $MODEL;	910	unshift @ISA, $MODEL;
534	push @{"$MODEL\::ISA"}, "AnyEvent::Base";	911	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
		912
		913	(shift @post_detect)->() while @post_detect;
535	}	914	}
536		915
537	$MODEL	916	$MODEL
538	}	917	}
539		918
…		…
549	$class->$func (@_);	928	$class->$func (@_);
550	}	929	}
551		930
552	package AnyEvent::Base;	931	package AnyEvent::Base;
553		932
		933	# default implementation for now and time
		934
		935	use Time::HiRes ();
		936
		937	sub time { Time::HiRes::time }
		938	sub now { Time::HiRes::time }
		939
554	# default implementation for ->condvar, ->wait, ->broadcast	940	# default implementation for ->condvar
555		941
556	sub condvar {	942	sub condvar {
557	bless \my $flag, "AnyEvent::Base::CondVar"	943	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	}	944	}
567		945
568	# default implementation for ->signal	946	# default implementation for ->signal
569		947
570	our %SIG_CB;	948	our %SIG_CB;
…		…
623	or Carp::croak "required option 'pid' is missing";	1001	or Carp::croak "required option 'pid' is missing";
624		1002
625	$PID_CB{$pid}{$arg{cb}} = $arg{cb};	1003	$PID_CB{$pid}{$arg{cb}} = $arg{cb};
626		1004
627	unless ($WNOHANG) {	1005	unless ($WNOHANG) {
628	$WNOHANG = eval { require POSIX; &POSIX::WNOHANG } \|\| 1;	1006	$WNOHANG = eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } \|\| 1;
629	}	1007	}
630		1008
631	unless ($CHLD_W) {	1009	unless ($CHLD_W) {
632	$CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld);	1010	$CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld);
633	# child could be a zombie already, so make at least one round	1011	# child could be a zombie already, so make at least one round
…		…
643	delete $PID_CB{$pid}{$cb};	1021	delete $PID_CB{$pid}{$cb};
644	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };	1022	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };
645		1023
646	undef $CHLD_W unless keys %PID_CB;	1024	undef $CHLD_W unless keys %PID_CB;
647	}	1025	}
		1026
		1027	package AnyEvent::CondVar;
		1028
		1029	our @ISA = AnyEvent::CondVar::Base::;
		1030
		1031	package AnyEvent::CondVar::Base;
		1032
		1033	use overload
		1034	'&{}' => sub { my $self = shift; sub { $self->send (@_) } },
		1035	fallback => 1;
		1036
		1037	sub _send {
		1038	# nop
		1039	}
		1040
		1041	sub send {
		1042	my $cv = shift;
		1043	$cv->{_ae_sent} = [@_];
		1044	(delete $cv->{_ae_cb})->($cv) if $cv->{_ae_cb};
		1045	$cv->_send;
		1046	}
		1047
		1048	sub croak {
		1049	$_[0]{_ae_croak} = $_[1];
		1050	$_[0]->send;
		1051	}
		1052
		1053	sub ready {
		1054	$_[0]{_ae_sent}
		1055	}
		1056
		1057	sub _wait {
		1058	AnyEvent->one_event while !$_[0]{_ae_sent};
		1059	}
		1060
		1061	sub recv {
		1062	$_[0]->_wait;
		1063
		1064	Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak};
		1065	wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0]
		1066	}
		1067
		1068	sub cb {
		1069	$_[0]{_ae_cb} = $_[1] if @_ > 1;
		1070	$_[0]{_ae_cb}
		1071	}
		1072
		1073	sub begin {
		1074	++$_[0]{_ae_counter};
		1075	$_[0]{_ae_end_cb} = $_[1] if @_ > 1;
		1076	}
		1077
		1078	sub end {
		1079	return if --$_[0]{_ae_counter};
		1080	&{ $_[0]{_ae_end_cb} \|\| sub { $_[0]->send } };
		1081	}
		1082
		1083	# undocumented/compatibility with pre-3.4
		1084	*broadcast = \&send;
		1085	*wait = \&_wait;
648		1086
649	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE	1087	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE
650		1088
651	This is an advanced topic that you do not normally need to use AnyEvent in	1089	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	1090	a module. This section is only of use to event loop authors who want to
…		…
709	model it chooses.	1147	model it chooses.
710		1148
711	=item C<PERL_ANYEVENT_MODEL>	1149	=item C<PERL_ANYEVENT_MODEL>
712		1150
713	This can be used to specify the event model to be used by AnyEvent, before	1151	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	1152	auto detection and -probing kicks in. It must be a string consisting
715	entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended	1153	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,	1154	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	1155	used as event model. If it fails to load AnyEvent will proceed with
718	autodetection and -probing.	1156	auto detection and -probing.
719		1157
720	This functionality might change in future versions.	1158	This functionality might change in future versions.
721		1159
722	For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you	1160	For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you
723	could start your program like this:	1161	could start your program like this:
724		1162
725	PERL_ANYEVENT_MODEL=Perl perl ...	1163	PERL_ANYEVENT_MODEL=Perl perl ...
		1164
		1165	=item C<PERL_ANYEVENT_PROTOCOLS>
		1166
		1167	Used by both L<AnyEvent::DNS> and L<AnyEvent::Socket> to determine preferences
		1168	for IPv4 or IPv6. The default is unspecified (and might change, or be the result
		1169	of auto probing).
		1170
		1171	Must be set to a comma-separated list of protocols or address families,
		1172	current supported: C<ipv4> and C<ipv6>. Only protocols mentioned will be
		1173	used, and preference will be given to protocols mentioned earlier in the
		1174	list.
		1175
		1176	This variable can effectively be used for denial-of-service attacks
		1177	against local programs (e.g. when setuid), although the impact is likely
		1178	small, as the program has to handle connection errors already-
		1179
		1180	Examples: C<PERL_ANYEVENT_PROTOCOLS=ipv4,ipv6> - prefer IPv4 over IPv6,
		1181	but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4>
		1182	- only support IPv4, never try to resolve or contact IPv6
		1183	addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or
		1184	IPv6, but prefer IPv6 over IPv4.
		1185
		1186	=item C<PERL_ANYEVENT_EDNS0>
		1187
		1188	Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension
		1189	for DNS. This extension is generally useful to reduce DNS traffic, but
		1190	some (broken) firewalls drop such DNS packets, which is why it is off by
		1191	default.
		1192
		1193	Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce
		1194	EDNS0 in its DNS requests.
		1195
		1196	=item C<PERL_ANYEVENT_MAX_FORKS>
		1197
		1198	The maximum number of child processes that C<AnyEvent::Util::fork_call>
		1199	will create in parallel.
726		1200
727	=back	1201	=back
728		1202
729	=head1 EXAMPLE PROGRAM	1203	=head1 EXAMPLE PROGRAM
730		1204
…		…
741	poll => 'r',	1215	poll => 'r',
742	cb => sub {	1216	cb => sub {
743	warn "io event <$_[0]>\n"; # will always output <r>	1217	warn "io event <$_[0]>\n"; # will always output <r>
744	chomp (my $input = <STDIN>); # read a line	1218	chomp (my $input = <STDIN>); # read a line
745	warn "read: $input\n"; # output what has been read	1219	warn "read: $input\n"; # output what has been read
746	$cv->broadcast if $input =~ /^q/i; # quit program if /^q/i	1220	$cv->send if $input =~ /^q/i; # quit program if /^q/i
747	},	1221	},
748	);	1222	);
749		1223
750	my $time_watcher; # can only be used once	1224	my $time_watcher; # can only be used once
751		1225
…		…
756	});	1230	});
757	}	1231	}
758		1232
759	new_timer; # create first timer	1233	new_timer; # create first timer
760		1234
761	$cv->wait; # wait until user enters /^q/i	1235	$cv->recv; # wait until user enters /^q/i
762		1236
763	=head1 REAL-WORLD EXAMPLE	1237	=head1 REAL-WORLD EXAMPLE
764		1238
765	Consider the L<Net::FCP> module. It features (among others) the following	1239	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:	1240	API calls, which are to freenet what HTTP GET requests are to http:
…		…
816	syswrite $txn->{fh}, $txn->{request}	1290	syswrite $txn->{fh}, $txn->{request}
817	or die "connection or write error";	1291	or die "connection or write error";
818	$txn->{w} = AnyEvent->io (fh => $txn->{fh}, poll => 'r', cb => sub { $txn->fh_ready_r });	1292	$txn->{w} = AnyEvent->io (fh => $txn->{fh}, poll => 'r', cb => sub { $txn->fh_ready_r });
819		1293
820	Again, C<fh_ready_r> waits till all data has arrived, and then stores the	1294	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:	1295	result and signals any possible waiters that the request has finished:
822		1296
823	sysread $txn->{fh}, $txn->{buf}, length $txn->{$buf};	1297	sysread $txn->{fh}, $txn->{buf}, length $txn->{$buf};
824		1298
825	if (end-of-file or data complete) {	1299	if (end-of-file or data complete) {
826	$txn->{result} = $txn->{buf};	1300	$txn->{result} = $txn->{buf};
827	$txn->{finished}->broadcast;	1301	$txn->{finished}->send;
828	$txb->{cb}->($txn) of $txn->{cb}; # also call callback	1302	$txb->{cb}->($txn) of $txn->{cb}; # also call callback
829	}	1303	}
830		1304
831	The C<result> method, finally, just waits for the finished signal (if the	1305	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	1306	request was already finished, it doesn't wait, of course, and returns the
833	data:	1307	data:
834		1308
835	$txn->{finished}->wait;	1309	$txn->{finished}->recv;
836	return $txn->{result};	1310	return $txn->{result};
837		1311
838	The actual code goes further and collects all errors (C<die>s, exceptions)	1312	The actual code goes further and collects all errors (C<die>s, exceptions)
839	that occured during request processing. The C<result> method detects	1313	that occurred during request processing. The C<result> method detects
840	whether an exception as thrown (it is stored inside the $txn object)	1314	whether an exception as thrown (it is stored inside the $txn object)
841	and just throws the exception, which means connection errors and other	1315	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	1316	problems get reported tot he code that tries to use the result, not in a
843	random callback.	1317	random callback.
844		1318
…		…
875		1349
876	my $quit = AnyEvent->condvar;	1350	my $quit = AnyEvent->condvar;
877		1351
878	$fcp->txn_client_get ($url)->cb (sub {	1352	$fcp->txn_client_get ($url)->cb (sub {
879	...	1353	...
880	$quit->broadcast;	1354	$quit->send;
881	});	1355	});
882		1356
883	$quit->wait;	1357	$quit->recv;
884		1358
885		1359
886	=head1 BENCHMARK	1360	=head1 BENCHMARKS
887		1361
888	To give you an idea of the performance and overheads that AnyEvent adds	1362	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	1363	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	1364	of various event loops I prepared some benchmarks.
891	event models natively and with anyevent. The benchmark creates a lot of	1365
892	timers (with a zero timeout) and I/O watchers (watching STDOUT, a pty, to	1366	=head2 BENCHMARKING ANYEVENT OVERHEAD
		1367
		1368	Here is a benchmark of various supported event models used natively and
		1369	through AnyEvent. The benchmark creates a lot of timers (with a zero
		1370	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	1371	which it is), lets them fire exactly once and destroys them again.
894	them again.
895		1372
896	Rewriting the benchmark to use many different sockets instead of using	1373	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	1374	distribution.
898	(socket creation is expensive), but qualitatively the same figures, so it
899	was not used.
900		1375
901	=head2 Explanation of the columns	1376	=head3 Explanation of the columns
902		1377
903	I<watcher> is the number of event watchers created/destroyed. Since	1378	I<watcher> is the number of event watchers created/destroyed. Since
904	different event models feature vastly different performances, each event	1379	different event models feature vastly different performances, each event
905	loop was given a number of watchers so that overall runtime is acceptable	1380	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	1381	and similar between tested event loop (and keep them from crashing): Glib
…		…
916	all watchers, to avoid adding memory overhead. That means closure creation	1391	all watchers, to avoid adding memory overhead. That means closure creation
917	and memory usage is not included in the figures.	1392	and memory usage is not included in the figures.
918		1393
919	I<invoke> is the time, in microseconds, used to invoke a simple	1394	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	1395	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	1396	invoked "watcher" times, it would C<< ->send >> a condvar once to
922	signal the end of this phase.	1397	signal the end of this phase.
923		1398
924	I<destroy> is the time, in microseconds, that it takes to destroy a single	1399	I<destroy> is the time, in microseconds, that it takes to destroy a single
925	watcher.	1400	watcher.
926		1401
927	=head2 Results	1402	=head3 Results
928		1403
929	name watchers bytes create invoke destroy comment	1404	name watchers bytes create invoke destroy comment
930	EV/EV 400000 244 0.56 0.46 0.31 EV native interface	1405	EV/EV 400000 244 0.56 0.46 0.31 EV native interface
931	EV/Any 100000 244 2.50 0.46 0.29 EV + AnyEvent watchers	1406	EV/Any 100000 244 2.50 0.46 0.29 EV + AnyEvent watchers
932	CoroEV/Any 100000 244 2.49 0.44 0.29 coroutines + Coro::Signal	1407	CoroEV/Any 100000 244 2.49 0.44 0.29 coroutines + Coro::Signal
933	Perl/Any 100000 513 4.92 0.87 1.12 pure perl implementation	1408	Perl/Any 100000 513 4.92 0.87 1.12 pure perl implementation
934	Event/Event 16000 516 31.88 31.30 0.85 Event native interface	1409	Event/Event 16000 516 31.88 31.30 0.85 Event native interface
935	Event/Any 16000 936 39.17 33.63 1.43 Event + AnyEvent watchers	1410	Event/Any 16000 590 35.75 31.42 1.08 Event + AnyEvent watchers
936	Glib/Any 16000 1357 98.22 12.41 54.00 quadratic behaviour	1411	Glib/Any 16000 1357 98.22 12.41 54.00 quadratic behaviour
937	Tk/Any 2000 1860 26.97 67.98 14.00 SEGV with >> 2000 watchers	1412	Tk/Any 2000 1860 26.97 67.98 14.00 SEGV with >> 2000 watchers
938	POE/Event 2000 6644 108.64 736.02 14.73 via POE::Loop::Event	1413	POE/Event 2000 6644 108.64 736.02 14.73 via POE::Loop::Event
939	POE/Select 2000 6343 94.13 809.12 565.96 via POE::Loop::Select	1414	POE/Select 2000 6343 94.13 809.12 565.96 via POE::Loop::Select
940		1415
941	=head2 Discussion	1416	=head3 Discussion
942		1417
943	The benchmark does I<not> measure scalability of the event loop very	1418	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)	1419	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	1420	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	1421	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	1422	the same time, so select/poll-based implementations get an unnatural speed
948	boost.	1423	boost.
949		1424
		1425	Also, note that the number of watchers usually has a nonlinear effect on
		1426	overall speed, that is, creating twice as many watchers doesn't take twice
		1427	the time - usually it takes longer. This puts event loops tested with a
		1428	higher number of watchers at a disadvantage.
		1429
		1430	To put the range of results into perspective, consider that on the
		1431	benchmark machine, handling an event takes roughly 1600 CPU cycles with
		1432	EV, 3100 CPU cycles with AnyEvent's pure perl loop and almost 3000000 CPU
		1433	cycles with POE.
		1434
950	C<EV> is the sole leader regarding speed and memory use, which are both	1435	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	1436	maximal/minimal, respectively. Even when going through AnyEvent, it uses
952	only two event loops that use slightly less memory (the C<Event> module	1437	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	1438	natively.
954	C<Event> natively.
955		1439
956	The pure perl implementation is hit in a few sweet spots (both the	1440	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	1441	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	1442	interpreter and the backend itself). Nevertheless this shows that it
959	same time). Nevertheless this shows that it adds very little overhead in	1443	adds very little overhead in itself. Like any select-based backend its
960	itself. Like any select-based backend its performance becomes really bad	1444	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	1445	them active), of course, but this was not subject of this benchmark.
962	this was not subject of this benchmark.
963		1446
964	The C<Event> module has a relatively high setup and callback invocation cost,	1447	The C<Event> module has a relatively high setup and callback invocation
965	but overall scores on the third place.	1448	cost, but overall scores in on the third place.
966		1449
967	C<Glib>'s memory usage is quite a bit bit higher, but it features a	1450	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	1451	faster callback invocation and overall ends up in the same class as
969	C<Event>. However, Glib scales extremely badly, doubling the number of	1452	C<Event>. However, Glib scales extremely badly, doubling the number of
970	watchers increases the processing time by more than a factor of four,	1453	watchers increases the processing time by more than a factor of four,
971	making it completely unusable when using larger numbers of watchers	1454	making it completely unusable when using larger numbers of watchers
972	(note that only a single file descriptor was used in the benchmark, so	1455	(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	1458	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	1459	more than 2000 watchers is a big setback, however, as correctness takes
977	precedence over speed. Nevertheless, its performance is surprising, as the	1460	precedence over speed. Nevertheless, its performance is surprising, as the
978	file descriptor is dup()ed for each watcher. This shows that the dup()	1461	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	1462	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	1463	hidden memory cost inside the kernel which is not reflected in the figures
981	figures above).	1464	above).
982		1465
983	C<POE>, regardless of underlying event loop (wether using its pure perl	1466	C<POE>, regardless of underlying event loop (whether using its pure perl
984	select-based backend or the Event module) shows abysmal performance and	1467	select-based backend or the Event module, the POE-EV backend couldn't
		1468	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,	1469	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	1470	as EV watchers, and 10 times as much memory as Event (the high memory
		1471	requirements are caused by requiring a session for each watcher). Watcher
987	invocation is almost 900 times slower than with AnyEvent's pure perl	1472	invocation speed is almost 900 times slower than with AnyEvent's pure perl
		1473	implementation.
		1474
988	implementation. The design of the POE adaptor class in AnyEvent can not	1475	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	1476	for the performance issues, though, as session creation overhead is
990	to execution of the state machine, which is coded pretty optimally within	1477	small compared to execution of the state machine, which is coded pretty
991	L<AnyEvent::Impl::POE>. POE simply seems to be abysmally slow.	1478	optimally within L<AnyEvent::Impl::POE> (and while everybody agrees that
		1479	using multiple sessions is not a good approach, especially regarding
		1480	memory usage, even the author of POE could not come up with a faster
		1481	design).
992		1482
993	=head2 Summary	1483	=head3 Summary
994		1484
		1485	=over 4
		1486
995	Using EV through AnyEvent is faster than any other event loop, but most	1487	=item * Using EV through AnyEvent is faster than any other event loop
996	event loops have acceptable performance with or without AnyEvent.	1488	(even when used without AnyEvent), but most event loops have acceptable
		1489	performance with or without AnyEvent.
997		1490
998	The overhead AnyEvent adds is usually much smaller than the overhead of	1491	=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	1492	the actual event loop, only with extremely fast event loops such as EV
1000	adds AnyEvent significant overhead.	1493	adds AnyEvent significant overhead.
1001		1494
1002	And you should simply avoid POE like the plague if you want performance or	1495	=item * You should avoid POE like the plague if you want performance or
1003	reasonable memory usage.	1496	reasonable memory usage.
1004		1497
		1498	=back
		1499
		1500	=head2 BENCHMARKING THE LARGE SERVER CASE
		1501
		1502	This benchmark actually benchmarks the event loop itself. It works by
		1503	creating a number of "servers": each server consists of a socket pair, a
		1504	timeout watcher that gets reset on activity (but never fires), and an I/O
		1505	watcher waiting for input on one side of the socket. Each time the socket
		1506	watcher reads a byte it will write that byte to a random other "server".
		1507
		1508	The effect is that there will be a lot of I/O watchers, only part of which
		1509	are active at any one point (so there is a constant number of active
		1510	fds for each loop iteration, but which fds these are is random). The
		1511	timeout is reset each time something is read because that reflects how
		1512	most timeouts work (and puts extra pressure on the event loops).
		1513
		1514	In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100
		1515	(1%) are active. This mirrors the activity of large servers with many
		1516	connections, most of which are idle at any one point in time.
		1517
		1518	Source code for this benchmark is found as F<eg/bench2> in the AnyEvent
		1519	distribution.
		1520
		1521	=head3 Explanation of the columns
		1522
		1523	I<sockets> is the number of sockets, and twice the number of "servers" (as
		1524	each server has a read and write socket end).
		1525
		1526	I<create> is the time it takes to create a socket pair (which is
		1527	nontrivial) and two watchers: an I/O watcher and a timeout watcher.
		1528
		1529	I<request>, the most important value, is the time it takes to handle a
		1530	single "request", that is, reading the token from the pipe and forwarding
		1531	it to another server. This includes deleting the old timeout and creating
		1532	a new one that moves the timeout into the future.
		1533
		1534	=head3 Results
		1535
		1536	name sockets create request
		1537	EV 20000 69.01 11.16
		1538	Perl 20000 73.32 35.87
		1539	Event 20000 212.62 257.32
		1540	Glib 20000 651.16 1896.30
		1541	POE 20000 349.67 12317.24 uses POE::Loop::Event
		1542
		1543	=head3 Discussion
		1544
		1545	This benchmark I<does> measure scalability and overall performance of the
		1546	particular event loop.
		1547
		1548	EV is again fastest. Since it is using epoll on my system, the setup time
		1549	is relatively high, though.
		1550
		1551	Perl surprisingly comes second. It is much faster than the C-based event
		1552	loops Event and Glib.
		1553
		1554	Event suffers from high setup time as well (look at its code and you will
		1555	understand why). Callback invocation also has a high overhead compared to
		1556	the C<< $_->() for .. >>-style loop that the Perl event loop uses. Event
		1557	uses select or poll in basically all documented configurations.
		1558
		1559	Glib is hit hard by its quadratic behaviour w.r.t. many watchers. It
		1560	clearly fails to perform with many filehandles or in busy servers.
		1561
		1562	POE is still completely out of the picture, taking over 1000 times as long
		1563	as EV, and over 100 times as long as the Perl implementation, even though
		1564	it uses a C-based event loop in this case.
		1565
		1566	=head3 Summary
		1567
		1568	=over 4
		1569
		1570	=item * The pure perl implementation performs extremely well.
		1571
		1572	=item * Avoid Glib or POE in large projects where performance matters.
		1573
		1574	=back
		1575
		1576	=head2 BENCHMARKING SMALL SERVERS
		1577
		1578	While event loops should scale (and select-based ones do not...) even to
		1579	large servers, most programs we (or I :) actually write have only a few
		1580	I/O watchers.
		1581
		1582	In this benchmark, I use the same benchmark program as in the large server
		1583	case, but it uses only eight "servers", of which three are active at any
		1584	one time. This should reflect performance for a small server relatively
		1585	well.
		1586
		1587	The columns are identical to the previous table.
		1588
		1589	=head3 Results
		1590
		1591	name sockets create request
		1592	EV 16 20.00 6.54
		1593	Perl 16 25.75 12.62
		1594	Event 16 81.27 35.86
		1595	Glib 16 32.63 15.48
		1596	POE 16 261.87 276.28 uses POE::Loop::Event
		1597
		1598	=head3 Discussion
		1599
		1600	The benchmark tries to test the performance of a typical small
		1601	server. While knowing how various event loops perform is interesting, keep
		1602	in mind that their overhead in this case is usually not as important, due
		1603	to the small absolute number of watchers (that is, you need efficiency and
		1604	speed most when you have lots of watchers, not when you only have a few of
		1605	them).
		1606
		1607	EV is again fastest.
		1608
		1609	Perl again comes second. It is noticeably faster than the C-based event
		1610	loops Event and Glib, although the difference is too small to really
		1611	matter.
		1612
		1613	POE also performs much better in this case, but is is still far behind the
		1614	others.
		1615
		1616	=head3 Summary
		1617
		1618	=over 4
		1619
		1620	=item * C-based event loops perform very well with small number of
		1621	watchers, as the management overhead dominates.
		1622
		1623	=back
		1624
1005		1625
1006	=head1 FORK	1626	=head1 FORK
1007		1627
1008	Most event libraries are not fork-safe. The ones who are usually are	1628	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.	1629	because they rely on inefficient but fork-safe C<select> or C<poll>
		1630	calls. Only L<EV> is fully fork-aware.
1010		1631
1011	If you have to fork, you must either do so I<before> creating your first	1632	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.	1633	watcher OR you must not use AnyEvent at all in the child.
1013		1634
1014		1635
…		…
1026		1647
1027	BEGIN { delete $ENV{PERL_ANYEVENT_MODEL} }	1648	BEGIN { delete $ENV{PERL_ANYEVENT_MODEL} }
1028		1649
1029	use AnyEvent;	1650	use AnyEvent;
1030		1651
		1652	Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can
		1653	be used to probe what backend is used and gain other information (which is
		1654	probably even less useful to an attacker than PERL_ANYEVENT_MODEL).
		1655
1031		1656
1032	=head1 SEE ALSO	1657	=head1 SEE ALSO
1033		1658
1034	Event modules: L<Coro::EV>, L<EV>, L<EV::Glib>, L<Glib::EV>,	1659	Utility functions: L<AnyEvent::Util>.
1035	L<Coro::Event>, L<Event>, L<Glib::Event>, L<Glib>, L<Coro>, L<Tk>,	1660
		1661	Event modules: L<EV>, L<EV::Glib>, L<Glib::EV>, L<Event>, L<Glib::Event>,
1036	L<Event::Lib>, L<Qt>, L<POE>.	1662	L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.
1037		1663
1038	Implementations: L<AnyEvent::Impl::CoroEV>, L<AnyEvent::Impl::EV>,	1664	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,
1039	L<AnyEvent::Impl::CoroEvent>, L<AnyEvent::Impl::Event>, L<AnyEvent::Impl::Glib>,	1665	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>,	1666	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,
1041	L<AnyEvent::Impl::Qt>, L<AnyEvent::Impl::POE>.	1667	L<AnyEvent::Impl::POE>.
1042		1668
		1669	Non-blocking file handles, sockets, TCP clients and
		1670	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>.
		1671
		1672	Asynchronous DNS: L<AnyEvent::DNS>.
		1673
		1674	Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>,
		1675
1043	Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>.	1676	Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>, L<AnyEvent::DNS>.
1044		1677
1045		1678
1046	=head1 AUTHOR	1679	=head1 AUTHOR
1047		1680
1048	Marc Lehmann <schmorp@schmorp.de>	1681	Marc Lehmann <schmorp@schmorp.de>

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Comparing AnyEvent/lib/AnyEvent.pm (file contents): Revision 1.83 by root, Fri Apr 25 13:39:08 2008 UTC vs. Revision 1.143 by root, Wed May 28 23:57:38 2008 UTC

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Comparing AnyEvent/lib/AnyEvent.pm (file contents):
Revision 1.83 by root, Fri Apr 25 13:39:08 2008 UTC vs.
Revision 1.143 by root, Wed May 28 23:57:38 2008 UTC