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Revision 1.355 by root, Fri Aug 12 00:53:29 2011 UTC

1	=head1 NAME	1	=head1 NAME
2		2
3	AnyEvent - provide framework for multiple event loops	3	AnyEvent - the DBI of event loop programming
4		4
5	EV, Event, Glib, Tk, Perl, Event::Lib, Qt and POE are various supported	5	EV, Event, Glib, Tk, Perl, Event::Lib, Irssi, rxvt-unicode, IO::Async, Qt
6	event loops.	6	and POE are various supported event loops/environments.
7		7
8	=head1 SYNOPSIS	8	=head1 SYNOPSIS
9		9
10	use AnyEvent;	10	use AnyEvent;
11		11
		12	# if you prefer function calls, look at the AE manpage for
		13	# an alternative API.
		14
12	# file descriptor readable	15	# file handle or descriptor readable
13	my $w = AnyEvent->io (fh => $fh, poll => "r", cb => sub { ... });	16	my $w = AnyEvent->io (fh => $fh, poll => "r", cb => sub { ... });
14		17
15	# one-shot or repeating timers	18	# one-shot or repeating timers
16	my $w = AnyEvent->timer (after => $seconds, cb => sub { ... });	19	my $w = AnyEvent->timer (after => $seconds, cb => sub { ... });
17	my $w = AnyEvent->timer (after => $seconds, interval => $seconds, cb => ...	20	my $w = AnyEvent->timer (after => $seconds, interval => $seconds, cb => ...);
18		21
19	print AnyEvent->now; # prints current event loop time	22	print AnyEvent->now; # prints current event loop time
20	print AnyEvent->time; # think Time::HiRes::time or simply CORE::time.	23	print AnyEvent->time; # think Time::HiRes::time or simply CORE::time.
21		24
22	# POSIX signal	25	# POSIX signal
…		…
40	=head1 INTRODUCTION/TUTORIAL	43	=head1 INTRODUCTION/TUTORIAL
41		44
42	This manpage is mainly a reference manual. If you are interested	45	This manpage is mainly a reference manual. If you are interested
43	in a tutorial or some gentle introduction, have a look at the	46	in a tutorial or some gentle introduction, have a look at the
44	L<AnyEvent::Intro> manpage.	47	L<AnyEvent::Intro> manpage.
		48
		49	=head1 SUPPORT
		50
		51	An FAQ document is available as L<AnyEvent::FAQ>.
		52
		53	There also is a mailinglist for discussing all things AnyEvent, and an IRC
		54	channel, too.
		55
		56	See the AnyEvent project page at the B<Schmorpforge Ta-Sa Software
		57	Repository>, at L<http://anyevent.schmorp.de>, for more info.
45		58
46	=head1 WHY YOU SHOULD USE THIS MODULE (OR NOT)	59	=head1 WHY YOU SHOULD USE THIS MODULE (OR NOT)
47		60
48	Glib, POE, IO::Async, Event... CPAN offers event models by the dozen	61	Glib, POE, IO::Async, Event... CPAN offers event models by the dozen
49	nowadays. So what is different about AnyEvent?	62	nowadays. So what is different about AnyEvent?
…		…
65	module users into the same thing by forcing them to use the same event	78	module users into the same thing by forcing them to use the same event
66	model you use.	79	model you use.
67		80
68	For modules like POE or IO::Async (which is a total misnomer as it is	81	For modules like POE or IO::Async (which is a total misnomer as it is
69	actually doing all I/O I<synchronously>...), using them in your module is	82	actually doing all I/O I<synchronously>...), using them in your module is
70	like joining a cult: After you joined, you are dependent on them and you	83	like joining a cult: After you join, you are dependent on them and you
71	cannot use anything else, as they are simply incompatible to everything	84	cannot use anything else, as they are simply incompatible to everything
72	that isn't them. What's worse, all the potential users of your	85	that isn't them. What's worse, all the potential users of your
73	module are I<also> forced to use the same event loop you use.	86	module are I<also> forced to use the same event loop you use.
74		87
75	AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works	88	AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works
76	fine. AnyEvent + Tk works fine etc. etc. but none of these work together	89	fine. AnyEvent + Tk works fine etc. etc. but none of these work together
77	with the rest: POE + IO::Async? No go. Tk + Event? No go. Again: if	90	with the rest: POE + EV? No go. Tk + Event? No go. Again: if your module
78	your module uses one of those, every user of your module has to use it,	91	uses one of those, every user of your module has to use it, too. But if
79	too. But if your module uses AnyEvent, it works transparently with all	92	your module uses AnyEvent, it works transparently with all event models it
80	event models it supports (including stuff like IO::Async, as long as those	93	supports (including stuff like IO::Async, as long as those use one of the
81	use one of the supported event loops. It is trivial to add new event loops	94	supported event loops. It is easy to add new event loops to AnyEvent, too,
82	to AnyEvent, too, so it is future-proof).	95	so it is future-proof).
83		96
84	In addition to being free of having to use I<the one and only true event	97	In addition to being free of having to use I<the one and only true event
85	model>, AnyEvent also is free of bloat and policy: with POE or similar	98	model>, AnyEvent also is free of bloat and policy: with POE or similar
86	modules, you get an enormous amount of code and strict rules you have to	99	modules, you get an enormous amount of code and strict rules you have to
87	follow. AnyEvent, on the other hand, is lean and up to the point, by only	100	follow. AnyEvent, on the other hand, is lean and to the point, by only
88	offering the functionality that is necessary, in as thin as a wrapper as	101	offering the functionality that is necessary, in as thin as a wrapper as
89	technically possible.	102	technically possible.
90		103
91	Of course, AnyEvent comes with a big (and fully optional!) toolbox	104	Of course, AnyEvent comes with a big (and fully optional!) toolbox
92	of useful functionality, such as an asynchronous DNS resolver, 100%	105	of useful functionality, such as an asynchronous DNS resolver, 100%
…		…
98	useful) and you want to force your users to use the one and only event	111	useful) and you want to force your users to use the one and only event
99	model, you should I<not> use this module.	112	model, you should I<not> use this module.
100		113
101	=head1 DESCRIPTION	114	=head1 DESCRIPTION
102		115
103	L<AnyEvent> provides an identical interface to multiple event loops. This	116	L<AnyEvent> provides a uniform interface to various event loops. This
104	allows module authors to utilise an event loop without forcing module	117	allows module authors to use event loop functionality without forcing
105	users to use the same event loop (as only a single event loop can coexist	118	module users to use a specific event loop implementation (since more
106	peacefully at any one time).	119	than one event loop cannot coexist peacefully).
107		120
108	The interface itself is vaguely similar, but not identical to the L<Event>	121	The interface itself is vaguely similar, but not identical to the L<Event>
109	module.	122	module.
110		123
111	During the first call of any watcher-creation method, the module tries	124	During the first call of any watcher-creation method, the module tries
112	to detect the currently loaded event loop by probing whether one of the	125	to detect the currently loaded event loop by probing whether one of the
113	following modules is already loaded: L<EV>,	126	following modules is already loaded: L<EV>, L<AnyEvent::Loop>,
114	L<Event>, L<Glib>, L<AnyEvent::Impl::Perl>, L<Tk>, L<Event::Lib>, L<Qt>,	127	L<Event>, L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>. The first one
115	L<POE>. The first one found is used. If none are found, the module tries	128	found is used. If none are detected, the module tries to load the first
116	to load these modules (excluding Tk, Event::Lib, Qt and POE as the pure perl	129	four modules in the order given; but note that if L<EV> is not
117	adaptor should always succeed) in the order given. The first one that can	130	available, the pure-perl L<AnyEvent::Loop> should always work, so
118	be successfully loaded will be used. If, after this, still none could be	131	the other two are not normally tried.
119	found, AnyEvent will fall back to a pure-perl event loop, which is not
120	very efficient, but should work everywhere.
121		132
122	Because AnyEvent first checks for modules that are already loaded, loading	133	Because AnyEvent first checks for modules that are already loaded, loading
123	an event model explicitly before first using AnyEvent will likely make	134	an event model explicitly before first using AnyEvent will likely make
124	that model the default. For example:	135	that model the default. For example:
125		136
…		…
127	use AnyEvent;	138	use AnyEvent;
128		139
129	# .. AnyEvent will likely default to Tk	140	# .. AnyEvent will likely default to Tk
130		141
131	The I<likely> means that, if any module loads another event model and	142	The I<likely> means that, if any module loads another event model and
132	starts using it, all bets are off. Maybe you should tell their authors to	143	starts using it, all bets are off - this case should be very rare though,
133	use AnyEvent so their modules work together with others seamlessly...	144	as very few modules hardcode event loops without announcing this very
		145	loudly.
134		146
135	The pure-perl implementation of AnyEvent is called	147	The pure-perl implementation of AnyEvent is called C<AnyEvent::Loop>. Like
136	C<AnyEvent::Impl::Perl>. Like other event modules you can load it	148	other event modules you can load it explicitly and enjoy the high
137	explicitly and enjoy the high availability of that event loop :)	149	availability of that event loop :)
138		150
139	=head1 WATCHERS	151	=head1 WATCHERS
140		152
141	AnyEvent has the central concept of a I<watcher>, which is an object that	153	AnyEvent has the central concept of a I<watcher>, which is an object that
142	stores relevant data for each kind of event you are waiting for, such as	154	stores relevant data for each kind of event you are waiting for, such as
…		…
147	callback when the event occurs (of course, only when the event model	159	callback when the event occurs (of course, only when the event model
148	is in control).	160	is in control).
149		161
150	Note that B<callbacks must not permanently change global variables>	162	Note that B<callbacks must not permanently change global variables>
151	potentially in use by the event loop (such as C<$_> or C<$[>) and that B<<	163	potentially in use by the event loop (such as C<$_> or C<$[>) and that B<<
152	callbacks must not C<die> >>. The former is good programming practise in	164	callbacks must not C<die> >>. The former is good programming practice in
153	Perl and the latter stems from the fact that exception handling differs	165	Perl and the latter stems from the fact that exception handling differs
154	widely between event loops.	166	widely between event loops.
155		167
156	To disable the watcher you have to destroy it (e.g. by setting the	168	To disable a watcher you have to destroy it (e.g. by setting the
157	variable you store it in to C<undef> or otherwise deleting all references	169	variable you store it in to C<undef> or otherwise deleting all references
158	to it).	170	to it).
159		171
160	All watchers are created by calling a method on the C<AnyEvent> class.	172	All watchers are created by calling a method on the C<AnyEvent> class.
161		173
162	Many watchers either are used with "recursion" (repeating timers for	174	Many watchers either are used with "recursion" (repeating timers for
163	example), or need to refer to their watcher object in other ways.	175	example), or need to refer to their watcher object in other ways.
164		176
165	An any way to achieve that is this pattern:	177	One way to achieve that is this pattern:
166		178
167	my $w; $w = AnyEvent->type (arg => value ..., cb => sub {	179	my $w; $w = AnyEvent->type (arg => value ..., cb => sub {
168	# you can use $w here, for example to undef it	180	# you can use $w here, for example to undef it
169	undef $w;	181	undef $w;
170	});	182	});
…		…
172	Note that C<my $w; $w => combination. This is necessary because in Perl,	184	Note that C<my $w; $w => combination. This is necessary because in Perl,
173	my variables are only visible after the statement in which they are	185	my variables are only visible after the statement in which they are
174	declared.	186	declared.
175		187
176	=head2 I/O WATCHERS	188	=head2 I/O WATCHERS
		189
		190	$w = AnyEvent->io (
		191	fh => <filehandle_or_fileno>,
		192	poll => <"r" or "w">,
		193	cb => <callback>,
		194	);
177		195
178	You can create an I/O watcher by calling the C<< AnyEvent->io >> method	196	You can create an I/O watcher by calling the C<< AnyEvent->io >> method
179	with the following mandatory key-value pairs as arguments:	197	with the following mandatory key-value pairs as arguments:
180		198
181	C<fh> is the Perl I<file handle> (or a naked file descriptor) to watch	199	C<fh> is the Perl I<file handle> (or a naked file descriptor) to watch
…		…
196		214
197	The I/O watcher might use the underlying file descriptor or a copy of it.	215	The I/O watcher might use the underlying file descriptor or a copy of it.
198	You must not close a file handle as long as any watcher is active on the	216	You must not close a file handle as long as any watcher is active on the
199	underlying file descriptor.	217	underlying file descriptor.
200		218
201	Some event loops issue spurious readyness notifications, so you should	219	Some event loops issue spurious readiness notifications, so you should
202	always use non-blocking calls when reading/writing from/to your file	220	always use non-blocking calls when reading/writing from/to your file
203	handles.	221	handles.
204		222
205	Example: wait for readability of STDIN, then read a line and disable the	223	Example: wait for readability of STDIN, then read a line and disable the
206	watcher.	224	watcher.
…		…
211	undef $w;	229	undef $w;
212	});	230	});
213		231
214	=head2 TIME WATCHERS	232	=head2 TIME WATCHERS
215		233
		234	$w = AnyEvent->timer (after => <seconds>, cb => <callback>);
		235
		236	$w = AnyEvent->timer (
		237	after => <fractional_seconds>,
		238	interval => <fractional_seconds>,
		239	cb => <callback>,
		240	);
		241
216	You can create a time watcher by calling the C<< AnyEvent->timer >>	242	You can create a time watcher by calling the C<< AnyEvent->timer >>
217	method with the following mandatory arguments:	243	method with the following mandatory arguments:
218		244
219	C<after> specifies after how many seconds (fractional values are	245	C<after> specifies after how many seconds (fractional values are
220	supported) the callback should be invoked. C<cb> is the callback to invoke	246	supported) the callback should be invoked. C<cb> is the callback to invoke
…		…
222		248
223	Although the callback might get passed parameters, their value and	249	Although the callback might get passed parameters, their value and
224	presence is undefined and you cannot rely on them. Portable AnyEvent	250	presence is undefined and you cannot rely on them. Portable AnyEvent
225	callbacks cannot use arguments passed to time watcher callbacks.	251	callbacks cannot use arguments passed to time watcher callbacks.
226		252
227	The callback will normally be invoked once only. If you specify another	253	The callback will normally be invoked only once. If you specify another
228	parameter, C<interval>, as a strictly positive number (> 0), then the	254	parameter, C<interval>, as a strictly positive number (> 0), then the
229	callback will be invoked regularly at that interval (in fractional	255	callback will be invoked regularly at that interval (in fractional
230	seconds) after the first invocation. If C<interval> is specified with a	256	seconds) after the first invocation. If C<interval> is specified with a
231	false value, then it is treated as if it were missing.	257	false value, then it is treated as if it were not specified at all.
232		258
233	The callback will be rescheduled before invoking the callback, but no	259	The callback will be rescheduled before invoking the callback, but no
234	attempt is done to avoid timer drift in most backends, so the interval is	260	attempt is made to avoid timer drift in most backends, so the interval is
235	only approximate.	261	only approximate.
236		262
237	Example: fire an event after 7.7 seconds.	263	Example: fire an event after 7.7 seconds.
238		264
239	my $w = AnyEvent->timer (after => 7.7, cb => sub {	265	my $w = AnyEvent->timer (after => 7.7, cb => sub {
…		…
257		283
258	While most event loops expect timers to specified in a relative way, they	284	While most event loops expect timers to specified in a relative way, they
259	use absolute time internally. This makes a difference when your clock	285	use absolute time internally. This makes a difference when your clock
260	"jumps", for example, when ntp decides to set your clock backwards from	286	"jumps", for example, when ntp decides to set your clock backwards from
261	the wrong date of 2014-01-01 to 2008-01-01, a watcher that is supposed to	287	the wrong date of 2014-01-01 to 2008-01-01, a watcher that is supposed to
262	fire "after" a second might actually take six years to finally fire.	288	fire "after a second" might actually take six years to finally fire.
263		289
264	AnyEvent cannot compensate for this. The only event loop that is conscious	290	AnyEvent cannot compensate for this. The only event loop that is conscious
265	about these issues is L<EV>, which offers both relative (ev_timer, based	291	of these issues is L<EV>, which offers both relative (ev_timer, based
266	on true relative time) and absolute (ev_periodic, based on wallclock time)	292	on true relative time) and absolute (ev_periodic, based on wallclock time)
267	timers.	293	timers.
268		294
269	AnyEvent always prefers relative timers, if available, matching the	295	AnyEvent always prefers relative timers, if available, matching the
270	AnyEvent API.	296	AnyEvent API.
…		…
292	I<In almost all cases (in all cases if you don't care), this is the	318	I<In almost all cases (in all cases if you don't care), this is the
293	function to call when you want to know the current time.>	319	function to call when you want to know the current time.>
294		320
295	This function is also often faster then C<< AnyEvent->time >>, and	321	This function is also often faster then C<< AnyEvent->time >>, and
296	thus the preferred method if you want some timestamp (for example,	322	thus the preferred method if you want some timestamp (for example,
297	L<AnyEvent::Handle> uses this to update it's activity timeouts).	323	L<AnyEvent::Handle> uses this to update its activity timeouts).
298		324
299	The rest of this section is only of relevance if you try to be very exact	325	The rest of this section is only of relevance if you try to be very exact
300	with your timing, you can skip it without bad conscience.	326	with your timing; you can skip it without a bad conscience.
301		327
302	For a practical example of when these times differ, consider L<Event::Lib>	328	For a practical example of when these times differ, consider L<Event::Lib>
303	and L<EV> and the following set-up:	329	and L<EV> and the following set-up:
304		330
305	The event loop is running and has just invoked one of your callback at	331	The event loop is running and has just invoked one of your callbacks at
306	time=500 (assume no other callbacks delay processing). In your callback,	332	time=500 (assume no other callbacks delay processing). In your callback,
307	you wait a second by executing C<sleep 1> (blocking the process for a	333	you wait a second by executing C<sleep 1> (blocking the process for a
308	second) and then (at time=501) you create a relative timer that fires	334	second) and then (at time=501) you create a relative timer that fires
309	after three seconds.	335	after three seconds.
310		336
…		…
330	difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into	356	difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into
331	account.	357	account.
332		358
333	=item AnyEvent->now_update	359	=item AnyEvent->now_update
334		360
335	Some event loops (such as L<EV> or L<AnyEvent::Impl::Perl>) cache	361	Some event loops (such as L<EV> or L<AnyEvent::Loop>) cache the current
336	the current time for each loop iteration (see the discussion of L<<	362	time for each loop iteration (see the discussion of L<< AnyEvent->now >>,
337	AnyEvent->now >>, above).	363	above).
338		364
339	When a callback runs for a long time (or when the process sleeps), then	365	When a callback runs for a long time (or when the process sleeps), then
340	this "current" time will differ substantially from the real time, which	366	this "current" time will differ substantially from the real time, which
341	might affect timers and time-outs.	367	might affect timers and time-outs.
342		368
343	When this is the case, you can call this method, which will update the	369	When this is the case, you can call this method, which will update the
344	event loop's idea of "current time".	370	event loop's idea of "current time".
345		371
		372	A typical example would be a script in a web server (e.g. C<mod_perl>) -
		373	when mod_perl executes the script, then the event loop will have the wrong
		374	idea about the "current time" (being potentially far in the past, when the
		375	script ran the last time). In that case you should arrange a call to C<<
		376	AnyEvent->now_update >> each time the web server process wakes up again
		377	(e.g. at the start of your script, or in a handler).
		378
346	Note that updating the time I<might> cause some events to be handled.	379	Note that updating the time I<might> cause some events to be handled.
347		380
348	=back	381	=back
349		382
350	=head2 SIGNAL WATCHERS	383	=head2 SIGNAL WATCHERS
		384
		385	$w = AnyEvent->signal (signal => <uppercase_signal_name>, cb => <callback>);
351		386
352	You can watch for signals using a signal watcher, C<signal> is the signal	387	You can watch for signals using a signal watcher, C<signal> is the signal
353	I<name> in uppercase and without any C<SIG> prefix, C<cb> is the Perl	388	I<name> in uppercase and without any C<SIG> prefix, C<cb> is the Perl
354	callback to be invoked whenever a signal occurs.	389	callback to be invoked whenever a signal occurs.
355		390
…		…
372		407
373	Example: exit on SIGINT	408	Example: exit on SIGINT
374		409
375	my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });	410	my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });
376		411
		412	=head3 Restart Behaviour
		413
		414	While restart behaviour is up to the event loop implementation, most will
		415	not restart syscalls (that includes L<Async::Interrupt> and AnyEvent's
		416	pure perl implementation).
		417
		418	=head3 Safe/Unsafe Signals
		419
		420	Perl signals can be either "safe" (synchronous to opcode handling) or
		421	"unsafe" (asynchronous) - the former might get delayed indefinitely, the
		422	latter might corrupt your memory.
		423
		424	AnyEvent signal handlers are, in addition, synchronous to the event loop,
		425	i.e. they will not interrupt your running perl program but will only be
		426	called as part of the normal event handling (just like timer, I/O etc.
		427	callbacks, too).
		428
377	=head3 Signal Races, Delays and Workarounds	429	=head3 Signal Races, Delays and Workarounds
378		430
379	Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support attaching	431	Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support attaching
380	callbacks to signals in a generic way, which is a pity, as you cannot do	432	callbacks to signals in a generic way, which is a pity, as you cannot
381	race-free signal handling in perl. AnyEvent will try to do it's best, but	433	do race-free signal handling in perl, requiring C libraries for
		434	this. AnyEvent will try to do its best, which means in some cases,
382	in some cases, signals will be delayed. The maximum time a signal might	435	signals will be delayed. The maximum time a signal might be delayed is
383	be delayed is specified in C<$AnyEvent::MAX_SIGNAL_LATENCY> (default: 10	436	specified in C<$AnyEvent::MAX_SIGNAL_LATENCY> (default: 10 seconds). This
384	seconds). This variable can be changed only before the first signal	437	variable can be changed only before the first signal watcher is created,
385	watcher is created, and should be left alone otherwise. Higher values	438	and should be left alone otherwise. This variable determines how often
		439	AnyEvent polls for signals (in case a wake-up was missed). Higher values
386	will cause fewer spurious wake-ups, which is better for power and CPU	440	will cause fewer spurious wake-ups, which is better for power and CPU
		441	saving.
		442
387	saving. All these problems can be avoided by installing the optional	443	All these problems can be avoided by installing the optional
388	L<Async::Interrupt> module. This will not work with inherently broken	444	L<Async::Interrupt> module, which works with most event loops. It will not
389	event loops such as L<Event> or L<Event::Lib> (and not with L<POE>	445	work with inherently broken event loops such as L<Event> or L<Event::Lib>
390	currently, as POE does it's own workaround with one-second latency). With	446	(and not with L<POE> currently, as POE does its own workaround with
391	those, you just have to suffer the delays.	447	one-second latency). For those, you just have to suffer the delays.
392		448
393	=head2 CHILD PROCESS WATCHERS	449	=head2 CHILD PROCESS WATCHERS
394		450
		451	$w = AnyEvent->child (pid => <process id>, cb => <callback>);
		452
395	You can also watch on a child process exit and catch its exit status.	453	You can also watch for a child process exit and catch its exit status.
396		454
397	The child process is specified by the C<pid> argument (if set to C<0>, it	455	The child process is specified by the C<pid> argument (on some backends,
398	watches for any child process exit). The watcher will triggered only when	456	using C<0> watches for any child process exit, on others this will
399	the child process has finished and an exit status is available, not on	457	croak). The watcher will be triggered only when the child process has
400	any trace events (stopped/continued).	458	finished and an exit status is available, not on any trace events
		459	(stopped/continued).
401		460
402	The callback will be called with the pid and exit status (as returned by	461	The callback will be called with the pid and exit status (as returned by
403	waitpid), so unlike other watcher types, you I<can> rely on child watcher	462	waitpid), so unlike other watcher types, you I<can> rely on child watcher
404	callback arguments.	463	callback arguments.
405		464
…		…
423	thing in an AnyEvent program, you I<have> to create at least one	482	thing in an AnyEvent program, you I<have> to create at least one
424	watcher before you C<fork> the child (alternatively, you can call	483	watcher before you C<fork> the child (alternatively, you can call
425	C<AnyEvent::detect>).	484	C<AnyEvent::detect>).
426		485
427	As most event loops do not support waiting for child events, they will be	486	As most event loops do not support waiting for child events, they will be
428	emulated by AnyEvent in most cases, in which the latency and race problems	487	emulated by AnyEvent in most cases, in which case the latency and race
429	mentioned in the description of signal watchers apply.	488	problems mentioned in the description of signal watchers apply.
430		489
431	Example: fork a process and wait for it	490	Example: fork a process and wait for it
432		491
433	my $done = AnyEvent->condvar;	492	my $done = AnyEvent->condvar;
434		493
…		…
446	# do something else, then wait for process exit	505	# do something else, then wait for process exit
447	$done->recv;	506	$done->recv;
448		507
449	=head2 IDLE WATCHERS	508	=head2 IDLE WATCHERS
450		509
451	Sometimes there is a need to do something, but it is not so important	510	$w = AnyEvent->idle (cb => <callback>);
452	to do it instantly, but only when there is nothing better to do. This
453	"nothing better to do" is usually defined to be "no other events need
454	attention by the event loop".
455		511
456	Idle watchers ideally get invoked when the event loop has nothing	512	This will repeatedly invoke the callback after the process becomes idle,
457	better to do, just before it would block the process to wait for new	513	until either the watcher is destroyed or new events have been detected.
458	events. Instead of blocking, the idle watcher is invoked.
459		514
460	Most event loops unfortunately do not really support idle watchers (only	515	Idle watchers are useful when there is a need to do something, but it
		516	is not so important (or wise) to do it instantly. The callback will be
		517	invoked only when there is "nothing better to do", which is usually
		518	defined as "all outstanding events have been handled and no new events
		519	have been detected". That means that idle watchers ideally get invoked
		520	when the event loop has just polled for new events but none have been
		521	detected. Instead of blocking to wait for more events, the idle watchers
		522	will be invoked.
		523
		524	Unfortunately, most event loops do not really support idle watchers (only
461	EV, Event and Glib do it in a usable fashion) - for the rest, AnyEvent	525	EV, Event and Glib do it in a usable fashion) - for the rest, AnyEvent
462	will simply call the callback "from time to time".	526	will simply call the callback "from time to time".
463		527
464	Example: read lines from STDIN, but only process them when the	528	Example: read lines from STDIN, but only process them when the
465	program is otherwise idle:	529	program is otherwise idle:
…		…
481	});	545	});
482	});	546	});
483		547
484	=head2 CONDITION VARIABLES	548	=head2 CONDITION VARIABLES
485		549
		550	$cv = AnyEvent->condvar;
		551
		552	$cv->send (<list>);
		553	my @res = $cv->recv;
		554
486	If you are familiar with some event loops you will know that all of them	555	If you are familiar with some event loops you will know that all of them
487	require you to run some blocking "loop", "run" or similar function that	556	require you to run some blocking "loop", "run" or similar function that
488	will actively watch for new events and call your callbacks.	557	will actively watch for new events and call your callbacks.
489		558
490	AnyEvent is slightly different: it expects somebody else to run the event	559	AnyEvent is slightly different: it expects somebody else to run the event
491	loop and will only block when necessary (usually when told by the user).	560	loop and will only block when necessary (usually when told by the user).
492		561
493	The instrument to do that is called a "condition variable", so called	562	The tool to do that is called a "condition variable", so called because
494	because they represent a condition that must become true.	563	they represent a condition that must become true.
495		564
496	Now is probably a good time to look at the examples further below.	565	Now is probably a good time to look at the examples further below.
497		566
498	Condition variables can be created by calling the C<< AnyEvent->condvar	567	Condition variables can be created by calling the C<< AnyEvent->condvar
499	>> method, usually without arguments. The only argument pair allowed is	568	>> method, usually without arguments. The only argument pair allowed is
…		…
504	After creation, the condition variable is "false" until it becomes "true"	573	After creation, the condition variable is "false" until it becomes "true"
505	by calling the C<send> method (or calling the condition variable as if it	574	by calling the C<send> method (or calling the condition variable as if it
506	were a callback, read about the caveats in the description for the C<<	575	were a callback, read about the caveats in the description for the C<<
507	->send >> method).	576	->send >> method).
508		577
509	Condition variables are similar to callbacks, except that you can	578	Since condition variables are the most complex part of the AnyEvent API, here are
510	optionally wait for them. They can also be called merge points - points	579	some different mental models of what they are - pick the ones you can connect to:
511	in time where multiple outstanding events have been processed. And yet	580
512	another way to call them is transactions - each condition variable can be	581	=over 4
513	used to represent a transaction, which finishes at some point and delivers	582
514	a result.	583	=item * Condition variables are like callbacks - you can call them (and pass them instead
		584	of callbacks). Unlike callbacks however, you can also wait for them to be called.
		585
		586	=item * Condition variables are signals - one side can emit or send them,
		587	the other side can wait for them, or install a handler that is called when
		588	the signal fires.
		589
		590	=item * Condition variables are like "Merge Points" - points in your program
		591	where you merge multiple independent results/control flows into one.
		592
		593	=item * Condition variables represent a transaction - functions that start
		594	some kind of transaction can return them, leaving the caller the choice
		595	between waiting in a blocking fashion, or setting a callback.
		596
		597	=item * Condition variables represent future values, or promises to deliver
		598	some result, long before the result is available.
		599
		600	=back
515		601
516	Condition variables are very useful to signal that something has finished,	602	Condition variables are very useful to signal that something has finished,
517	for example, if you write a module that does asynchronous http requests,	603	for example, if you write a module that does asynchronous http requests,
518	then a condition variable would be the ideal candidate to signal the	604	then a condition variable would be the ideal candidate to signal the
519	availability of results. The user can either act when the callback is	605	availability of results. The user can either act when the callback is
…		…
532		618
533	Condition variables are represented by hash refs in perl, and the keys	619	Condition variables are represented by hash refs in perl, and the keys
534	used by AnyEvent itself are all named C<_ae_XXX> to make subclassing	620	used by AnyEvent itself are all named C<_ae_XXX> to make subclassing
535	easy (it is often useful to build your own transaction class on top of	621	easy (it is often useful to build your own transaction class on top of
536	AnyEvent). To subclass, use C<AnyEvent::CondVar> as base class and call	622	AnyEvent). To subclass, use C<AnyEvent::CondVar> as base class and call
537	it's C<new> method in your own C<new> method.	623	its C<new> method in your own C<new> method.
538		624
539	There are two "sides" to a condition variable - the "producer side" which	625	There are two "sides" to a condition variable - the "producer side" which
540	eventually calls C<< -> send >>, and the "consumer side", which waits	626	eventually calls C<< -> send >>, and the "consumer side", which waits
541	for the send to occur.	627	for the send to occur.
542		628
543	Example: wait for a timer.	629	Example: wait for a timer.
544		630
545	# wait till the result is ready	631	# condition: "wait till the timer is fired"
546	my $result_ready = AnyEvent->condvar;	632	my $timer_fired = AnyEvent->condvar;
547		633
548	# do something such as adding a timer	634	# create the timer - we could wait for, say
549	# or socket watcher the calls $result_ready->send	635	# a handle becomign ready, or even an
550	# when the "result" is ready.	636	# AnyEvent::HTTP request to finish, but
551	# in this case, we simply use a timer:	637	# in this case, we simply use a timer:
552	my $w = AnyEvent->timer (	638	my $w = AnyEvent->timer (
553	after => 1,	639	after => 1,
554	cb => sub { $result_ready->send },	640	cb => sub { $timer_fired->send },
555	);	641	);
556		642
557	# this "blocks" (while handling events) till the callback	643	# this "blocks" (while handling events) till the callback
558	# calls -<send	644	# calls ->send
559	$result_ready->recv;	645	$timer_fired->recv;
560		646
561	Example: wait for a timer, but take advantage of the fact that condition	647	Example: wait for a timer, but take advantage of the fact that condition
562	variables are also callable directly.	648	variables are also callable directly.
563		649
564	my $done = AnyEvent->condvar;	650	my $done = AnyEvent->condvar;
…		…
607	they were a code reference). Calling them directly is the same as calling	693	they were a code reference). Calling them directly is the same as calling
608	C<send>.	694	C<send>.
609		695
610	=item $cv->croak ($error)	696	=item $cv->croak ($error)
611		697
612	Similar to send, but causes all call's to C<< ->recv >> to invoke	698	Similar to send, but causes all calls to C<< ->recv >> to invoke
613	C<Carp::croak> with the given error message/object/scalar.	699	C<Carp::croak> with the given error message/object/scalar.
614		700
615	This can be used to signal any errors to the condition variable	701	This can be used to signal any errors to the condition variable
616	user/consumer. Doing it this way instead of calling C<croak> directly	702	user/consumer. Doing it this way instead of calling C<croak> directly
617	delays the error detetcion, but has the overwhelmign advantage that it	703	delays the error detection, but has the overwhelming advantage that it
618	diagnoses the error at the place where the result is expected, and not	704	diagnoses the error at the place where the result is expected, and not
619	deep in some event clalback without connection to the actual code causing	705	deep in some event callback with no connection to the actual code causing
620	the problem.	706	the problem.
621		707
622	=item $cv->begin ([group callback])	708	=item $cv->begin ([group callback])
623		709
624	=item $cv->end	710	=item $cv->end
…		…
627	one. For example, a function that pings many hosts in parallel might want	713	one. For example, a function that pings many hosts in parallel might want
628	to use a condition variable for the whole process.	714	to use a condition variable for the whole process.
629		715
630	Every call to C<< ->begin >> will increment a counter, and every call to	716	Every call to C<< ->begin >> will increment a counter, and every call to
631	C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end	717	C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end
632	>>, the (last) callback passed to C<begin> will be executed. That callback	718	>>, the (last) callback passed to C<begin> will be executed, passing the
633	is I<supposed> to call C<< ->send >>, but that is not required. If no	719	condvar as first argument. That callback is I<supposed> to call C<< ->send
634	callback was set, C<send> will be called without any arguments.	720	>>, but that is not required. If no group callback was set, C<send> will
		721	be called without any arguments.
635		722
636	You can think of C<< $cv->send >> giving you an OR condition (one call	723	You can think of C<< $cv->send >> giving you an OR condition (one call
637	sends), while C<< $cv->begin >> and C<< $cv->end >> giving you an AND	724	sends), while C<< $cv->begin >> and C<< $cv->end >> giving you an AND
638	condition (all C<begin> calls must be C<end>'ed before the condvar sends).	725	condition (all C<begin> calls must be C<end>'ed before the condvar sends).
639		726
…		…
661	one call to C<begin>, so the condvar waits for all calls to C<end> before	748	one call to C<begin>, so the condvar waits for all calls to C<end> before
662	sending.	749	sending.
663		750
664	The ping example mentioned above is slightly more complicated, as the	751	The ping example mentioned above is slightly more complicated, as the
665	there are results to be passwd back, and the number of tasks that are	752	there are results to be passwd back, and the number of tasks that are
666	begung can potentially be zero:	753	begun can potentially be zero:
667		754
668	my $cv = AnyEvent->condvar;	755	my $cv = AnyEvent->condvar;
669		756
670	my %result;	757	my %result;
671	$cv->begin (sub { $cv->send (\%result) });	758	$cv->begin (sub { shift->send (\%result) });
672		759
673	for my $host (@list_of_hosts) {	760	for my $host (@list_of_hosts) {
674	$cv->begin;	761	$cv->begin;
675	ping_host_then_call_callback $host, sub {	762	ping_host_then_call_callback $host, sub {
676	$result{$host} = ...;	763	$result{$host} = ...;
…		…
692	to be called once the counter reaches C<0>, and second, it ensures that	779	to be called once the counter reaches C<0>, and second, it ensures that
693	C<send> is called even when C<no> hosts are being pinged (the loop	780	C<send> is called even when C<no> hosts are being pinged (the loop
694	doesn't execute once).	781	doesn't execute once).
695		782
696	This is the general pattern when you "fan out" into multiple (but	783	This is the general pattern when you "fan out" into multiple (but
697	potentially none) subrequests: use an outer C<begin>/C<end> pair to set	784	potentially zero) subrequests: use an outer C<begin>/C<end> pair to set
698	the callback and ensure C<end> is called at least once, and then, for each	785	the callback and ensure C<end> is called at least once, and then, for each
699	subrequest you start, call C<begin> and for each subrequest you finish,	786	subrequest you start, call C<begin> and for each subrequest you finish,
700	call C<end>.	787	call C<end>.
701		788
702	=back	789	=back
…		…
709	=over 4	796	=over 4
710		797
711	=item $cv->recv	798	=item $cv->recv
712		799
713	Wait (blocking if necessary) until the C<< ->send >> or C<< ->croak	800	Wait (blocking if necessary) until the C<< ->send >> or C<< ->croak
714	>> methods have been called on c<$cv>, while servicing other watchers	801	>> methods have been called on C<$cv>, while servicing other watchers
715	normally.	802	normally.
716		803
717	You can only wait once on a condition - additional calls are valid but	804	You can only wait once on a condition - additional calls are valid but
718	will return immediately.	805	will return immediately.
719		806
…		…
736	caller decide whether the call will block or not (for example, by coupling	823	caller decide whether the call will block or not (for example, by coupling
737	condition variables with some kind of request results and supporting	824	condition variables with some kind of request results and supporting
738	callbacks so the caller knows that getting the result will not block,	825	callbacks so the caller knows that getting the result will not block,
739	while still supporting blocking waits if the caller so desires).	826	while still supporting blocking waits if the caller so desires).
740		827
741	You can ensure that C<< -recv >> never blocks by setting a callback and	828	You can ensure that C<< ->recv >> never blocks by setting a callback and
742	only calling C<< ->recv >> from within that callback (or at a later	829	only calling C<< ->recv >> from within that callback (or at a later
743	time). This will work even when the event loop does not support blocking	830	time). This will work even when the event loop does not support blocking
744	waits otherwise.	831	waits otherwise.
745		832
746	=item $bool = $cv->ready	833	=item $bool = $cv->ready
…		…
752		839
753	This is a mutator function that returns the callback set and optionally	840	This is a mutator function that returns the callback set and optionally
754	replaces it before doing so.	841	replaces it before doing so.
755		842
756	The callback will be called when the condition becomes "true", i.e. when	843	The callback will be called when the condition becomes "true", i.e. when
757	C<send> or C<croak> are called, with the only argument being the condition	844	C<send> or C<croak> are called, with the only argument being the
758	variable itself. Calling C<recv> inside the callback or at any later time	845	condition variable itself. If the condition is already true, the
759	is guaranteed not to block.	846	callback is called immediately when it is set. Calling C<recv> inside
		847	the callback or at any later time is guaranteed not to block.
760		848
761	=back	849	=back
762		850
763	=head1 SUPPORTED EVENT LOOPS/BACKENDS	851	=head1 SUPPORTED EVENT LOOPS/BACKENDS
764		852
…		…
767	=over 4	855	=over 4
768		856
769	=item Backends that are autoprobed when no other event loop can be found.	857	=item Backends that are autoprobed when no other event loop can be found.
770		858
771	EV is the preferred backend when no other event loop seems to be in	859	EV is the preferred backend when no other event loop seems to be in
772	use. If EV is not installed, then AnyEvent will try Event, and, failing	860	use. If EV is not installed, then AnyEvent will fall back to its own
773	that, will fall back to its own pure-perl implementation, which is	861	pure-perl implementation, which is available everywhere as it comes with
774	available everywhere as it comes with AnyEvent itself.	862	AnyEvent itself.
775		863
776	AnyEvent::Impl::EV based on EV (interface to libev, best choice).	864	AnyEvent::Impl::EV based on EV (interface to libev, best choice).
777	AnyEvent::Impl::Event based on Event, very stable, few glitches.
778	AnyEvent::Impl::Perl pure-perl implementation, fast and portable.	865	AnyEvent::Impl::Perl pure-perl AnyEvent::Loop, fast and portable.
779		866
780	=item Backends that are transparently being picked up when they are used.	867	=item Backends that are transparently being picked up when they are used.
781		868
782	These will be used when they are currently loaded when the first watcher	869	These will be used if they are already loaded when the first watcher
783	is created, in which case it is assumed that the application is using	870	is created, in which case it is assumed that the application is using
784	them. This means that AnyEvent will automatically pick the right backend	871	them. This means that AnyEvent will automatically pick the right backend
785	when the main program loads an event module before anything starts to	872	when the main program loads an event module before anything starts to
786	create watchers. Nothing special needs to be done by the main program.	873	create watchers. Nothing special needs to be done by the main program.
787		874
		875	AnyEvent::Impl::Event based on Event, very stable, few glitches.
788	AnyEvent::Impl::Glib based on Glib, slow but very stable.	876	AnyEvent::Impl::Glib based on Glib, slow but very stable.
789	AnyEvent::Impl::Tk based on Tk, very broken.	877	AnyEvent::Impl::Tk based on Tk, very broken.
790	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.	878	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
791	AnyEvent::Impl::POE based on POE, very slow, some limitations.	879	AnyEvent::Impl::POE based on POE, very slow, some limitations.
		880	AnyEvent::Impl::Irssi used when running within irssi.
		881	AnyEvent::Impl::IOAsync based on IO::Async.
		882	AnyEvent::Impl::Cocoa based on Cocoa::EventLoop.
		883	AnyEvent::Impl::FLTK based on FLTK.
792		884
793	=item Backends with special needs.	885	=item Backends with special needs.
794		886
795	Qt requires the Qt::Application to be instantiated first, but will	887	Qt requires the Qt::Application to be instantiated first, but will
796	otherwise be picked up automatically. As long as the main program	888	otherwise be picked up automatically. As long as the main program
797	instantiates the application before any AnyEvent watchers are created,	889	instantiates the application before any AnyEvent watchers are created,
798	everything should just work.	890	everything should just work.
799		891
800	AnyEvent::Impl::Qt based on Qt.	892	AnyEvent::Impl::Qt based on Qt.
801		893
802	Support for IO::Async can only be partial, as it is too broken and
803	architecturally limited to even support the AnyEvent API. It also
804	is the only event loop that needs the loop to be set explicitly, so
805	it can only be used by a main program knowing about AnyEvent. See
806	L<AnyEvent::Impl::Async> for the gory details.
807
808	AnyEvent::Impl::IOAsync based on IO::Async, cannot be autoprobed.
809
810	=item Event loops that are indirectly supported via other backends.	894	=item Event loops that are indirectly supported via other backends.
811		895
812	Some event loops can be supported via other modules:	896	Some event loops can be supported via other modules:
813		897
814	There is no direct support for WxWidgets (L<Wx>) or L<Prima>.	898	There is no direct support for WxWidgets (L<Wx>) or L<Prima>.
…		…
839	Contains C<undef> until the first watcher is being created, before the	923	Contains C<undef> until the first watcher is being created, before the
840	backend has been autodetected.	924	backend has been autodetected.
841		925
842	Afterwards it contains the event model that is being used, which is the	926	Afterwards it contains the event model that is being used, which is the
843	name of the Perl class implementing the model. This class is usually one	927	name of the Perl class implementing the model. This class is usually one
844	of the C<AnyEvent::Impl:xxx> modules, but can be any other class in the	928	of the C<AnyEvent::Impl::xxx> modules, but can be any other class in the
845	case AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode> it	929	case AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode> it
846	will be C<urxvt::anyevent>).	930	will be C<urxvt::anyevent>).
847		931
848	=item AnyEvent::detect	932	=item AnyEvent::detect
849		933
850	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model	934	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model
851	if necessary. You should only call this function right before you would	935	if necessary. You should only call this function right before you would
852	have created an AnyEvent watcher anyway, that is, as late as possible at	936	have created an AnyEvent watcher anyway, that is, as late as possible at
853	runtime, and not e.g. while initialising of your module.	937	runtime, and not e.g. during initialisation of your module.
854		938
855	If you need to do some initialisation before AnyEvent watchers are	939	If you need to do some initialisation before AnyEvent watchers are
856	created, use C<post_detect>.	940	created, use C<post_detect>.
857		941
858	=item $guard = AnyEvent::post_detect { BLOCK }	942	=item $guard = AnyEvent::post_detect { BLOCK }
859		943
860	Arranges for the code block to be executed as soon as the event model is	944	Arranges for the code block to be executed as soon as the event model is
861	autodetected (or immediately if this has already happened).	945	autodetected (or immediately if that has already happened).
862		946
863	The block will be executed I<after> the actual backend has been detected	947	The block will be executed I<after> the actual backend has been detected
864	(C<$AnyEvent::MODEL> is set), but I<before> any watchers have been	948	(C<$AnyEvent::MODEL> is set), but I<before> any watchers have been
865	created, so it is possible to e.g. patch C<@AnyEvent::ISA> or do	949	created, so it is possible to e.g. patch C<@AnyEvent::ISA> or do
866	other initialisations - see the sources of L<AnyEvent::Strict> or	950	other initialisations - see the sources of L<AnyEvent::Strict> or
…		…
870	event module detection too early, for example, L<AnyEvent::AIO> creates	954	event module detection too early, for example, L<AnyEvent::AIO> creates
871	and installs the global L<IO::AIO> watcher in a C<post_detect> block to	955	and installs the global L<IO::AIO> watcher in a C<post_detect> block to
872	avoid autodetecting the event module at load time.	956	avoid autodetecting the event module at load time.
873		957
874	If called in scalar or list context, then it creates and returns an object	958	If called in scalar or list context, then it creates and returns an object
875	that automatically removes the callback again when it is destroyed. See	959	that automatically removes the callback again when it is destroyed (or
		960	C<undef> when the hook was immediately executed). See L<AnyEvent::AIO> for
876	L<Coro::BDB> for a case where this is useful.	961	a case where this is useful.
		962
		963	Example: Create a watcher for the IO::AIO module and store it in
		964	C<$WATCHER>, but do so only do so after the event loop is initialised.
		965
		966	our WATCHER;
		967
		968	my $guard = AnyEvent::post_detect {
		969	$WATCHER = AnyEvent->io (fh => IO::AIO::poll_fileno, poll => 'r', cb => \&IO::AIO::poll_cb);
		970	};
		971
		972	# the ||= is important in case post_detect immediately runs the block,
		973	# as to not clobber the newly-created watcher. assigning both watcher and
		974	# post_detect guard to the same variable has the advantage of users being
		975	# able to just C<undef $WATCHER> if the watcher causes them grief.
		976
		977	$WATCHER ||= $guard;
877		978
878	=item @AnyEvent::post_detect	979	=item @AnyEvent::post_detect
879		980
880	If there are any code references in this array (you can C<push> to it	981	If there are any code references in this array (you can C<push> to it
881	before or after loading AnyEvent), then they will called directly after	982	before or after loading AnyEvent), then they will be called directly
882	the event loop has been chosen.	983	after the event loop has been chosen.
883		984
884	You should check C<$AnyEvent::MODEL> before adding to this array, though:	985	You should check C<$AnyEvent::MODEL> before adding to this array, though:
885	if it is defined then the event loop has already been detected, and the	986	if it is defined then the event loop has already been detected, and the
886	array will be ignored.	987	array will be ignored.
887		988
888	Best use C<AnyEvent::post_detect { BLOCK }> when your application allows	989	Best use C<AnyEvent::post_detect { BLOCK }> when your application allows
889	it,as it takes care of these details.	990	it, as it takes care of these details.
890		991
891	This variable is mainly useful for modules that can do something useful	992	This variable is mainly useful for modules that can do something useful
892	when AnyEvent is used and thus want to know when it is initialised, but do	993	when AnyEvent is used and thus want to know when it is initialised, but do
893	not need to even load it by default. This array provides the means to hook	994	not need to even load it by default. This array provides the means to hook
894	into AnyEvent passively, without loading it.	995	into AnyEvent passively, without loading it.
895		996
		997	Example: To load Coro::AnyEvent whenever Coro and AnyEvent are used
		998	together, you could put this into Coro (this is the actual code used by
		999	Coro to accomplish this):
		1000
		1001	if (defined $AnyEvent::MODEL) {
		1002	# AnyEvent already initialised, so load Coro::AnyEvent
		1003	require Coro::AnyEvent;
		1004	} else {
		1005	# AnyEvent not yet initialised, so make sure to load Coro::AnyEvent
		1006	# as soon as it is
		1007	push @AnyEvent::post_detect, sub { require Coro::AnyEvent };
		1008	}
		1009
		1010	=item AnyEvent::postpone { BLOCK }
		1011
		1012	Arranges for the block to be executed as soon as possible, but not before
		1013	the call itself returns. In practise, the block will be executed just
		1014	before the event loop polls for new events, or shortly afterwards.
		1015
		1016	This function never returns anything (to make the C<return postpone { ...
		1017	}> idiom more useful.
		1018
		1019	To understand the usefulness of this function, consider a function that
		1020	asynchronously does something for you and returns some transaction
		1021	object or guard to let you cancel the operation. For example,
		1022	C<AnyEvent::Socket::tcp_connect>:
		1023
		1024	# start a conenction attempt unless one is active
		1025	$self->{connect_guard} ||= AnyEvent::Socket::tcp_connect "www.example.net", 80, sub {
		1026	delete $self->{connect_guard};
		1027	...
		1028	};
		1029
		1030	Imagine that this function could instantly call the callback, for
		1031	example, because it detects an obvious error such as a negative port
		1032	number. Invoking the callback before the function returns causes problems
		1033	however: the callback will be called and will try to delete the guard
		1034	object. But since the function hasn't returned yet, there is nothing to
		1035	delete. When the function eventually returns it will assign the guard
		1036	object to C<< $self->{connect_guard} >>, where it will likely never be
		1037	deleted, so the program thinks it is still trying to connect.
		1038
		1039	This is where C<AnyEvent::postpone> should be used. Instead of calling the
		1040	callback directly on error:
		1041
		1042	$cb->(undef), return # signal error to callback, BAD!
		1043	if $some_error_condition;
		1044
		1045	It should use C<postpone>:
		1046
		1047	AnyEvent::postpone { $cb->(undef) }, return # signal error to callback, later
		1048	if $some_error_condition;
		1049
896	=back	1050	=back
897		1051
898	=head1 WHAT TO DO IN A MODULE	1052	=head1 WHAT TO DO IN A MODULE
899		1053
900	As a module author, you should C<use AnyEvent> and call AnyEvent methods	1054	As a module author, you should C<use AnyEvent> and call AnyEvent methods
…		…
910	because it will stall the whole program, and the whole point of using	1064	because it will stall the whole program, and the whole point of using
911	events is to stay interactive.	1065	events is to stay interactive.
912		1066
913	It is fine, however, to call C<< ->recv >> when the user of your module	1067	It is fine, however, to call C<< ->recv >> when the user of your module
914	requests it (i.e. if you create a http request object ad have a method	1068	requests it (i.e. if you create a http request object ad have a method
915	called C<results> that returns the results, it should call C<< ->recv >>	1069	called C<results> that returns the results, it may call C<< ->recv >>
916	freely, as the user of your module knows what she is doing. always).	1070	freely, as the user of your module knows what she is doing. Always).
917		1071
918	=head1 WHAT TO DO IN THE MAIN PROGRAM	1072	=head1 WHAT TO DO IN THE MAIN PROGRAM
919		1073
920	There will always be a single main program - the only place that should	1074	There will always be a single main program - the only place that should
921	dictate which event model to use.	1075	dictate which event model to use.
922		1076
923	If it doesn't care, it can just "use AnyEvent" and use it itself, or not	1077	If the program is not event-based, it need not do anything special, even
924	do anything special (it does not need to be event-based) and let AnyEvent	1078	when it depends on a module that uses an AnyEvent. If the program itself
925	decide which implementation to chose if some module relies on it.	1079	uses AnyEvent, but does not care which event loop is used, all it needs
		1080	to do is C<use AnyEvent>. In either case, AnyEvent will choose the best
		1081	available loop implementation.
926		1082
927	If the main program relies on a specific event model - for example, in	1083	If the main program relies on a specific event model - for example, in
928	Gtk2 programs you have to rely on the Glib module - you should load the	1084	Gtk2 programs you have to rely on the Glib module - you should load the
929	event module before loading AnyEvent or any module that uses it: generally	1085	event module before loading AnyEvent or any module that uses it: generally
930	speaking, you should load it as early as possible. The reason is that	1086	speaking, you should load it as early as possible. The reason is that
931	modules might create watchers when they are loaded, and AnyEvent will	1087	modules might create watchers when they are loaded, and AnyEvent will
932	decide on the event model to use as soon as it creates watchers, and it	1088	decide on the event model to use as soon as it creates watchers, and it
933	might chose the wrong one unless you load the correct one yourself.	1089	might choose the wrong one unless you load the correct one yourself.
934		1090
935	You can chose to use a pure-perl implementation by loading the	1091	You can chose to use a pure-perl implementation by loading the
936	C<AnyEvent::Impl::Perl> module, which gives you similar behaviour	1092	C<AnyEvent::Loop> module, which gives you similar behaviour
937	everywhere, but letting AnyEvent chose the model is generally better.	1093	everywhere, but letting AnyEvent chose the model is generally better.
938		1094
939	=head2 MAINLOOP EMULATION	1095	=head2 MAINLOOP EMULATION
940		1096
941	Sometimes (often for short test scripts, or even standalone programs who	1097	Sometimes (often for short test scripts, or even standalone programs who
…		…
956	=head1 OTHER MODULES	1112	=head1 OTHER MODULES
957		1113
958	The following is a non-exhaustive list of additional modules that use	1114	The following is a non-exhaustive list of additional modules that use
959	AnyEvent as a client and can therefore be mixed easily with other AnyEvent	1115	AnyEvent as a client and can therefore be mixed easily with other AnyEvent
960	modules and other event loops in the same program. Some of the modules	1116	modules and other event loops in the same program. Some of the modules
961	come with AnyEvent, most are available via CPAN.	1117	come as part of AnyEvent, the others are available via CPAN.
962		1118
963	=over 4	1119	=over 4
964		1120
965	=item L<AnyEvent::Util>	1121	=item L<AnyEvent::Util>
966		1122
967	Contains various utility functions that replace often-used but blocking	1123	Contains various utility functions that replace often-used blocking
968	functions such as C<inet_aton> by event-/callback-based versions.	1124	functions such as C<inet_aton> with event/callback-based versions.
969		1125
970	=item L<AnyEvent::Socket>	1126	=item L<AnyEvent::Socket>
971		1127
972	Provides various utility functions for (internet protocol) sockets,	1128	Provides various utility functions for (internet protocol) sockets,
973	addresses and name resolution. Also functions to create non-blocking tcp	1129	addresses and name resolution. Also functions to create non-blocking tcp
…		…
975		1131
976	=item L<AnyEvent::Handle>	1132	=item L<AnyEvent::Handle>
977		1133
978	Provide read and write buffers, manages watchers for reads and writes,	1134	Provide read and write buffers, manages watchers for reads and writes,
979	supports raw and formatted I/O, I/O queued and fully transparent and	1135	supports raw and formatted I/O, I/O queued and fully transparent and
980	non-blocking SSL/TLS (via L<AnyEvent::TLS>.	1136	non-blocking SSL/TLS (via L<AnyEvent::TLS>).
981		1137
982	=item L<AnyEvent::DNS>	1138	=item L<AnyEvent::DNS>
983		1139
984	Provides rich asynchronous DNS resolver capabilities.	1140	Provides rich asynchronous DNS resolver capabilities.
985		1141
		1142	=item L<AnyEvent::HTTP>, L<AnyEvent::IRC>, L<AnyEvent::XMPP>, L<AnyEvent::GPSD>, L<AnyEvent::IGS>, L<AnyEvent::FCP>
		1143
		1144	Implement event-based interfaces to the protocols of the same name (for
		1145	the curious, IGS is the International Go Server and FCP is the Freenet
		1146	Client Protocol).
		1147
		1148	=item L<AnyEvent::Handle::UDP>
		1149
		1150	Here be danger!
		1151
		1152	As Pauli would put it, "Not only is it not right, it's not even wrong!" -
		1153	there are so many things wrong with AnyEvent::Handle::UDP, most notably
		1154	its use of a stream-based API with a protocol that isn't streamable, that
		1155	the only way to improve it is to delete it.
		1156
		1157	It features data corruption (but typically only under load) and general
		1158	confusion. On top, the author is not only clueless about UDP but also
		1159	fact-resistant - some gems of his understanding: "connect doesn't work
		1160	with UDP", "UDP packets are not IP packets", "UDP only has datagrams, not
		1161	packets", "I don't need to implement proper error checking as UDP doesn't
		1162	support error checking" and so on - he doesn't even understand what's
		1163	wrong with his module when it is explained to him.
		1164
986	=item L<AnyEvent::HTTP>	1165	=item L<AnyEvent::DBI>
987		1166
988	A simple-to-use HTTP library that is capable of making a lot of concurrent	1167	Executes L<DBI> requests asynchronously in a proxy process for you,
989	HTTP requests.	1168	notifying you in an event-based way when the operation is finished.
		1169
		1170	=item L<AnyEvent::AIO>
		1171
		1172	Truly asynchronous (as opposed to non-blocking) I/O, should be in the
		1173	toolbox of every event programmer. AnyEvent::AIO transparently fuses
		1174	L<IO::AIO> and AnyEvent together, giving AnyEvent access to event-based
		1175	file I/O, and much more.
990		1176
991	=item L<AnyEvent::HTTPD>	1177	=item L<AnyEvent::HTTPD>
992		1178
993	Provides a simple web application server framework.	1179	A simple embedded webserver.
994		1180
995	=item L<AnyEvent::FastPing>	1181	=item L<AnyEvent::FastPing>
996		1182
997	The fastest ping in the west.	1183	The fastest ping in the west.
998
999	=item L<AnyEvent::DBI>
1000
1001	Executes L<DBI> requests asynchronously in a proxy process.
1002
1003	=item L<AnyEvent::AIO>
1004
1005	Truly asynchronous I/O, should be in the toolbox of every event
1006	programmer. AnyEvent::AIO transparently fuses L<IO::AIO> and AnyEvent
1007	together.
1008
1009	=item L<AnyEvent::BDB>
1010
1011	Truly asynchronous Berkeley DB access. AnyEvent::BDB transparently fuses
1012	L<BDB> and AnyEvent together.
1013
1014	=item L<AnyEvent::GPSD>
1015
1016	A non-blocking interface to gpsd, a daemon delivering GPS information.
1017
1018	=item L<AnyEvent::IRC>
1019
1020	AnyEvent based IRC client module family (replacing the older Net::IRC3).
1021
1022	=item L<AnyEvent::XMPP>
1023
1024	AnyEvent based XMPP (Jabber protocol) module family (replacing the older
1025	Net::XMPP2>.
1026
1027	=item L<AnyEvent::IGS>
1028
1029	A non-blocking interface to the Internet Go Server protocol (used by
1030	L<App::IGS>).
1031
1032	=item L<Net::FCP>
1033
1034	AnyEvent-based implementation of the Freenet Client Protocol, birthplace
1035	of AnyEvent.
1036
1037	=item L<Event::ExecFlow>
1038
1039	High level API for event-based execution flow control.
1040		1184
1041	=item L<Coro>	1185	=item L<Coro>
1042		1186
1043	Has special support for AnyEvent via L<Coro::AnyEvent>.	1187	Has special support for AnyEvent via L<Coro::AnyEvent>.
1044		1188
…		…
1048		1192
1049	package AnyEvent;	1193	package AnyEvent;
1050		1194
1051	# basically a tuned-down version of common::sense	1195	# basically a tuned-down version of common::sense
1052	sub common_sense {	1196	sub common_sense {
1053	# no warnings	1197	# from common:.sense 3.4
1054	${^WARNING_BITS} ^= ${^WARNING_BITS};	1198	${^WARNING_BITS} ^= ${^WARNING_BITS} ^ "\x3c\x3f\x33\x00\x0f\xf0\x0f\xc0\xf0\xfc\x33\x00";
1055	# use strict vars subs	1199	# use strict vars subs - NO UTF-8, as Util.pm doesn't like this atm. (uts46data.pl)
1056	$^H |= 0x00000600;	1200	$^H |= 0x00000600;
1057	}	1201	}
1058		1202
1059	BEGIN { AnyEvent::common_sense }	1203	BEGIN { AnyEvent::common_sense }
1060		1204
1061	use Carp ();	1205	use Carp ();
1062		1206
1063	our $VERSION = 4.85;	1207	our $VERSION = '5.34';
1064	our $MODEL;	1208	our $MODEL;
1065		1209
1066	our $AUTOLOAD;	1210	our $AUTOLOAD;
1067	our @ISA;	1211	our @ISA;
1068		1212
1069	our @REGISTRY;	1213	our @REGISTRY;
1070		1214
1071	our $WIN32;
1072
1073	our $VERBOSE;	1215	our $VERBOSE;
1074		1216
1075	BEGIN {	1217	BEGIN {
1076	eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }";	1218	require "AnyEvent/constants.pl";
		1219
1077	eval "sub TAINT(){ " . (${^TAINT}*1) . " }";	1220	eval "sub TAINT (){" . (${^TAINT}*1) . "}";
1078		1221
1079	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}	1222	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}
1080	if ${^TAINT};	1223	if ${^TAINT};
1081		1224
1082	$VERBOSE = $ENV{PERL_ANYEVENT_VERBOSE}*1;	1225	$VERBOSE = $ENV{PERL_ANYEVENT_VERBOSE}*1;
…		…
1092	$PROTOCOL{$_} = ++$idx	1235	$PROTOCOL{$_} = ++$idx
1093	for reverse split /\s*,\s*/,	1236	for reverse split /\s*,\s*/,
1094	$ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";	1237	$ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";
1095	}	1238	}
1096		1239
		1240	our @post_detect;
		1241
		1242	sub post_detect(&) {
		1243	my ($cb) = @_;
		1244
		1245	push @post_detect, $cb;
		1246
		1247	defined wantarray
		1248	? bless \$cb, "AnyEvent::Util::postdetect"
		1249	: ()
		1250	}
		1251
		1252	sub AnyEvent::Util::postdetect::DESTROY {
		1253	@post_detect = grep $_ != ${$_[0]}, @post_detect;
		1254	}
		1255
		1256	our $POSTPONE_W;
		1257	our @POSTPONE;
		1258
		1259	sub _postpone_exec {
		1260	undef $POSTPONE_W;
		1261
		1262	&{ shift @POSTPONE }
		1263	while @POSTPONE;
		1264	}
		1265
		1266	sub postpone(&) {
		1267	push @POSTPONE, shift;
		1268
		1269	$POSTPONE_W ||= AE::timer (0, 0, \&_postpone_exec);
		1270
		1271	()
		1272	}
		1273
1097	my @models = (	1274	our @models = (
1098	[EV:: => AnyEvent::Impl::EV::],	1275	[EV:: => AnyEvent::Impl::EV:: , 1],
1099	[Event:: => AnyEvent::Impl::Event::],	1276	[AnyEvent::Loop:: => AnyEvent::Impl::Perl:: , 1],
1100	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::],
1101	# everything below here will not be autoprobed	1277	# everything below here will not (normally) be autoprobed
1102	# as the pureperl backend should work everywhere	1278	# as the pure perl backend should work everywhere
1103	# and is usually faster	1279	# and is usually faster
		1280	[Event:: => AnyEvent::Impl::Event::, 1],
1104	[Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers	1281	[Glib:: => AnyEvent::Impl::Glib:: , 1], # becomes extremely slow with many watchers
1105	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy	1282	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
		1283	[Irssi:: => AnyEvent::Impl::Irssi::], # Irssi has a bogus "Event" package
1106	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles	1284	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
1107	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program	1285	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program
1108	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza	1286	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
1109	[Wx:: => AnyEvent::Impl::POE::],	1287	[Wx:: => AnyEvent::Impl::POE::],
1110	[Prima:: => AnyEvent::Impl::POE::],	1288	[Prima:: => AnyEvent::Impl::POE::],
1111	# IO::Async is just too broken - we would need workarounds for its	1289	[IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # a bitch to autodetect
1112	# byzantine signal and broken child handling, among others.	1290	[Cocoa::EventLoop:: => AnyEvent::Impl::Cocoa::],
1113	# IO::Async is rather hard to detect, as it doesn't have any	1291	[FLTK:: => AnyEvent::Impl::FLTK::],
1114	# obvious default class.
1115	# [IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program
1116	# [IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program
1117	# [IO::Async::Notifier:: => AnyEvent::Impl::IOAsync::], # requires special main program
1118	);	1292	);
1119		1293
1120	our %method = map +($_ => 1),	1294	our %method = map +($_ => 1),
1121	qw(io timer time now now_update signal child idle condvar one_event DESTROY);	1295	qw(io timer time now now_update signal child idle condvar DESTROY);
1122		1296
1123	our @post_detect;
1124
1125	sub post_detect(&) {	1297	sub detect() {
1126	my ($cb) = @_;	1298	# free some memory
		1299	*detect = sub () { $MODEL };
1127		1300
1128	if ($MODEL) {	1301	local $!; # for good measure
1129	$cb->();	1302	local $SIG{__DIE__};
1130		1303
1131	1	1304	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z0-9:]+)$/) {
		1305	my $model = $1;
		1306	$model = "AnyEvent::Impl::$model" unless $model =~ s/::$//;
		1307	if (eval "require $model") {
		1308	$MODEL = $model;
		1309	warn "AnyEvent: loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.\n" if $VERBOSE >= 2;
1132	} else {	1310	} else {
1133	push @post_detect, $cb;	1311	warn "AnyEvent: unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@" if $VERBOSE;
1134		1312	}
1135	defined wantarray
1136	? bless \$cb, "AnyEvent::Util::postdetect"
1137	: ()
1138	}	1313	}
1139	}
1140		1314
1141	sub AnyEvent::Util::postdetect::DESTROY {	1315	# check for already loaded models
1142	@post_detect = grep $_ != ${$_[0]}, @post_detect;
1143	}
1144
1145	sub detect() {
1146	unless ($MODEL) {	1316	unless ($MODEL) {
1147	local $SIG{__DIE__};	1317	for (@REGISTRY, @models) {
1148		1318	my ($package, $model) = @$_;
1149	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {	1319	if (${"$package\::VERSION"} > 0) {
1150	my $model = "AnyEvent::Impl::$1";
1151	if (eval "require $model") {	1320	if (eval "require $model") {
1152	$MODEL = $model;	1321	$MODEL = $model;
1153	warn "AnyEvent: loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.\n" if $VERBOSE >= 2;	1322	warn "AnyEvent: autodetected model '$model', using it.\n" if $VERBOSE >= 2;
1154	} else {	1323	last;
1155	warn "AnyEvent: unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@" if $VERBOSE;	1324	}
1156	}	1325	}
1157	}	1326	}
1158		1327
1159	# check for already loaded models
1160	unless ($MODEL) {	1328	unless ($MODEL) {
		1329	# try to autoload a model
1161	for (@REGISTRY, @models) {	1330	for (@REGISTRY, @models) {
1162	my ($package, $model) = @$_;	1331	my ($package, $model, $autoload) = @$_;
		1332	if (
		1333	$autoload
		1334	and eval "require $package"
1163	if (${"$package\::VERSION"} > 0) {	1335	and ${"$package\::VERSION"} > 0
1164	if (eval "require $model") {	1336	and eval "require $model"
		1337	) {
1165	$MODEL = $model;	1338	$MODEL = $model;
1166	warn "AnyEvent: autodetected model '$model', using it.\n" if $VERBOSE >= 2;	1339	warn "AnyEvent: autoloaded model '$model', using it.\n" if $VERBOSE >= 2;
1167	last;	1340	last;
1168	}
1169	}	1341	}
1170	}	1342	}
1171		1343
1172	unless ($MODEL) {
1173	# try to load a model
1174
1175	for (@REGISTRY, @models) {
1176	my ($package, $model) = @$_;
1177	if (eval "require $package"
1178	and ${"$package\::VERSION"} > 0
1179	and eval "require $model") {
1180	$MODEL = $model;
1181	warn "AnyEvent: autoprobed model '$model', using it.\n" if $VERBOSE >= 2;
1182	last;
1183	}
1184	}
1185
1186	$MODEL	1344	$MODEL
1187	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.\n";	1345	or die "AnyEvent: backend autodetection failed - did you properly install AnyEvent?\n";
1188	}
1189	}	1346	}
1190
1191	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
1192
1193	unshift @ISA, $MODEL;
1194
1195	require AnyEvent::Strict if $ENV{PERL_ANYEVENT_STRICT};
1196
1197	(shift @post_detect)->() while @post_detect;
1198	}	1347	}
1199		1348
		1349	# free memory only needed for probing
		1350	undef @models;
		1351	undef @REGISTRY;
		1352
		1353	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
		1354	unshift @ISA, $MODEL;
		1355
		1356	# now nuke some methods that are overridden by the backend.
		1357	# SUPER usage is not allowed in these.
		1358	for (qw(time signal child idle)) {
		1359	undef &{"AnyEvent::Base::$_"}
		1360	if defined &{"$MODEL\::$_"};
		1361	}
		1362
		1363	if ($ENV{PERL_ANYEVENT_STRICT}) {
		1364	eval { require AnyEvent::Strict };
		1365	warn "AnyEvent: cannot load AnyEvent::Strict: $@"
		1366	if $@ && $VERBOSE;
		1367	}
		1368
		1369	(shift @post_detect)->() while @post_detect;
		1370	undef @post_detect;
		1371
		1372	*post_detect = sub(&) {
		1373	shift->();
		1374
		1375	undef
		1376	};
		1377
		1378	# recover a few more bytes
		1379	postpone {
		1380	undef &AUTOLOAD;
		1381	};
		1382
1200	$MODEL	1383	$MODEL
1201	}	1384	}
		1385
		1386	our %method = map +($_ => 1),
		1387	qw(io timer time now now_update signal child idle condvar DESTROY);
1202		1388
1203	sub AUTOLOAD {	1389	sub AUTOLOAD {
1204	(my $func = $AUTOLOAD) =~ s/.*://;	1390	(my $func = $AUTOLOAD) =~ s/.*://;
1205		1391
1206	$method{$func}	1392	$method{$func}
1207	or Carp::croak "$func: not a valid method for AnyEvent objects";	1393	or Carp::croak "$func: not a valid AnyEvent class method";
1208		1394
1209	detect unless $MODEL;	1395	# free some memory
		1396	undef %method;
		1397
		1398	detect;
1210		1399
1211	my $class = shift;	1400	my $class = shift;
1212	$class->$func (@_);	1401	$class->$func (@_);
1213	}	1402	}
1214		1403
…		…
1227	# we assume CLOEXEC is already set by perl in all important cases	1416	# we assume CLOEXEC is already set by perl in all important cases
1228		1417
1229	($fh2, $rw)	1418	($fh2, $rw)
1230	}	1419	}
1231		1420
		1421	=head1 SIMPLIFIED AE API
		1422
		1423	Starting with version 5.0, AnyEvent officially supports a second, much
		1424	simpler, API that is designed to reduce the calling, typing and memory
		1425	overhead by using function call syntax and a fixed number of parameters.
		1426
		1427	See the L<AE> manpage for details.
		1428
		1429	=cut
		1430
		1431	package AE;
		1432
		1433	our $VERSION = $AnyEvent::VERSION;
		1434
		1435
		1436	sub _reset() {
		1437	eval q{
		1438	# fall back to the main API by default - backends and AnyEvent::Base
		1439	# implementations can overwrite these.
		1440
		1441	sub io($$$) {
		1442	AnyEvent->io (fh => $_[0], poll => $_[1] ? "w" : "r", cb => $_[2])
		1443	}
		1444
		1445	sub timer($$$) {
		1446	AnyEvent->timer (after => $_[0], interval => $_[1], cb => $_[2])
		1447	}
		1448
		1449	sub signal($$) {
		1450	AnyEvent->signal (signal => $_[0], cb => $_[1])
		1451	}
		1452
		1453	sub child($$) {
		1454	AnyEvent->child (pid => $_[0], cb => $_[1])
		1455	}
		1456
		1457	sub idle($) {
		1458	AnyEvent->idle (cb => $_[0])
		1459	}
		1460
		1461	sub cv(;&) {
		1462	AnyEvent->condvar (@_ ? (cb => $_[0]) : ())
		1463	}
		1464
		1465	sub now() {
		1466	AnyEvent->now
		1467	}
		1468
		1469	sub now_update() {
		1470	AnyEvent->now_update
		1471	}
		1472
		1473	sub time() {
		1474	AnyEvent->time
		1475	}
		1476
		1477	*postpone = \&AnyEvent::postpone;
		1478	};
		1479	die if $@;
		1480	}
		1481
		1482	BEGIN { _reset }
		1483
1232	package AnyEvent::Base;	1484	package AnyEvent::Base;
1233		1485
1234	# default implementations for many methods	1486	# default implementations for many methods
1235		1487
1236	sub _time {	1488	sub time {
		1489	eval q{ # poor man's autoloading {}
1237	# probe for availability of Time::HiRes	1490	# probe for availability of Time::HiRes
1238	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {	1491	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {
1239	warn "AnyEvent: using Time::HiRes for sub-second timing accuracy.\n" if $VERBOSE >= 8;	1492	warn "AnyEvent: using Time::HiRes for sub-second timing accuracy.\n" if $VERBOSE >= 8;
1240	*_time = \&Time::HiRes::time;	1493	*AE::time = \&Time::HiRes::time;
1241	# if (eval "use POSIX (); (POSIX::times())...	1494	# if (eval "use POSIX (); (POSIX::times())...
1242	} else {	1495	} else {
1243	warn "AnyEvent: using built-in time(), WARNING, no sub-second resolution!\n" if $VERBOSE;	1496	warn "AnyEvent: using built-in time(), WARNING, no sub-second resolution!\n" if $VERBOSE;
1244	*_time = sub { time }; # epic fail	1497	*AE::time = sub (){ time }; # epic fail
		1498	}
		1499
		1500	*time = sub { AE::time }; # different prototypes
1245	}	1501	};
		1502	die if $@;
1246		1503
1247	&_time	1504	&time
1248	}	1505	}
1249		1506
1250	sub time { _time }	1507	*now = \&time;
1251	sub now { _time }	1508
1252	sub now_update { }	1509	sub now_update { }
1253		1510
		1511	sub _poll {
		1512	Carp::croak "$AnyEvent::MODEL does not support blocking waits. Caught";
		1513	}
		1514
1254	# default implementation for ->condvar	1515	# default implementation for ->condvar
		1516	# in fact, the default should not be overwritten
1255		1517
1256	sub condvar {	1518	sub condvar {
		1519	eval q{ # poor man's autoloading {}
		1520	*condvar = sub {
1257	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"	1521	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"
		1522	};
		1523
		1524	*AE::cv = sub (;&) {
		1525	bless { @_ ? (_ae_cb => shift) : () }, "AnyEvent::CondVar"
		1526	};
		1527	};
		1528	die if $@;
		1529
		1530	&condvar
1258	}	1531	}
1259		1532
1260	# default implementation for ->signal	1533	# default implementation for ->signal
1261		1534
1262	our $HAVE_ASYNC_INTERRUPT;	1535	our $HAVE_ASYNC_INTERRUPT;
		1536
		1537	sub _have_async_interrupt() {
		1538	$HAVE_ASYNC_INTERRUPT = 1*(!$ENV{PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT}
		1539	&& eval "use Async::Interrupt 1.02 (); 1")
		1540	unless defined $HAVE_ASYNC_INTERRUPT;
		1541
		1542	$HAVE_ASYNC_INTERRUPT
		1543	}
		1544
1263	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);	1545	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);
1264	our (%SIG_ASY, %SIG_ASY_W);	1546	our (%SIG_ASY, %SIG_ASY_W);
1265	our ($SIG_COUNT, $SIG_TW);	1547	our ($SIG_COUNT, $SIG_TW);
1266		1548
1267	sub _signal_exec {
1268	$HAVE_ASYNC_INTERRUPT
1269	? $SIGPIPE_R->drain
1270	: sysread $SIGPIPE_R, my $dummy, 9;
1271
1272	while (%SIG_EV) {
1273	for (keys %SIG_EV) {
1274	delete $SIG_EV{$_};
1275	$_->() for values %{ $SIG_CB{$_} || {} };
1276	}
1277	}
1278	}
1279
1280	# install a dumym wakeupw atcher to reduce signal catching latency	1549	# install a dummy wakeup watcher to reduce signal catching latency
		1550	# used by Impls
1281	sub _sig_add() {	1551	sub _sig_add() {
1282	unless ($SIG_COUNT++) {	1552	unless ($SIG_COUNT++) {
1283	# try to align timer on a full-second boundary, if possible	1553	# try to align timer on a full-second boundary, if possible
1284	my $NOW = AnyEvent->now;	1554	my $NOW = AE::now;
1285		1555
1286	$SIG_TW = AnyEvent->timer (	1556	$SIG_TW = AE::timer
1287	after => $MAX_SIGNAL_LATENCY - ($NOW - int $NOW),	1557	$MAX_SIGNAL_LATENCY - ($NOW - int $NOW),
1288	interval => $MAX_SIGNAL_LATENCY,	1558	$MAX_SIGNAL_LATENCY,
1289	cb => sub { }, # just for the PERL_ASYNC_CHECK	1559	sub { } # just for the PERL_ASYNC_CHECK
1290	);	1560	;
1291	}	1561	}
1292	}	1562	}
1293		1563
1294	sub _sig_del {	1564	sub _sig_del {
1295	undef $SIG_TW	1565	undef $SIG_TW
1296	unless --$SIG_COUNT;	1566	unless --$SIG_COUNT;
1297	}	1567	}
1298		1568
		1569	our $_sig_name_init; $_sig_name_init = sub {
		1570	eval q{ # poor man's autoloading {}
		1571	undef $_sig_name_init;
		1572
		1573	if (_have_async_interrupt) {
		1574	*sig2num = \&Async::Interrupt::sig2num;
		1575	*sig2name = \&Async::Interrupt::sig2name;
		1576	} else {
		1577	require Config;
		1578
		1579	my %signame2num;
		1580	@signame2num{ split ' ', $Config::Config{sig_name} }
		1581	= split ' ', $Config::Config{sig_num};
		1582
		1583	my @signum2name;
		1584	@signum2name[values %signame2num] = keys %signame2num;
		1585
		1586	*sig2num = sub($) {
		1587	$_[0] > 0 ? shift : $signame2num{+shift}
		1588	};
		1589	*sig2name = sub ($) {
		1590	$_[0] > 0 ? $signum2name[+shift] : shift
		1591	};
		1592	}
		1593	};
		1594	die if $@;
		1595	};
		1596
		1597	sub sig2num ($) { &$_sig_name_init; &sig2num }
		1598	sub sig2name($) { &$_sig_name_init; &sig2name }
		1599
1299	sub _signal {	1600	sub signal {
1300	my (undef, %arg) = @_;	1601	eval q{ # poor man's autoloading {}
		1602	# probe for availability of Async::Interrupt
		1603	if (_have_async_interrupt) {
		1604	warn "AnyEvent: using Async::Interrupt for race-free signal handling.\n" if $VERBOSE >= 8;
1301		1605
1302	my $signal = uc $arg{signal}	1606	$SIGPIPE_R = new Async::Interrupt::EventPipe;
1303	or Carp::croak "required option 'signal' is missing";	1607	$SIG_IO = AE::io $SIGPIPE_R->fileno, 0, \&_signal_exec;
1304		1608
1305	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};	1609	} else {
		1610	warn "AnyEvent: using emulated perl signal handling with latency timer.\n" if $VERBOSE >= 8;
1306		1611
1307	if ($HAVE_ASYNC_INTERRUPT) {	1612	if (AnyEvent::WIN32) {
1308	# async::interrupt	1613	require AnyEvent::Util;
1309		1614
1310	$SIG_ASY{$signal} ||= do {	1615	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
1311	my $asy = new Async::Interrupt	1616	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R, 1) if $SIGPIPE_R;
1312	cb => sub { undef $SIG_EV{$signal} },	1617	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W, 1) if $SIGPIPE_W; # just in case
1313	signal => $signal,	1618	} else {
1314	pipe => [$SIGPIPE_R->filenos],	1619	pipe $SIGPIPE_R, $SIGPIPE_W;
		1620	fcntl $SIGPIPE_R, AnyEvent::F_SETFL, AnyEvent::O_NONBLOCK if $SIGPIPE_R;
		1621	fcntl $SIGPIPE_W, AnyEvent::F_SETFL, AnyEvent::O_NONBLOCK if $SIGPIPE_W; # just in case
		1622
		1623	# not strictly required, as $^F is normally 2, but let's make sure...
		1624	fcntl $SIGPIPE_R, AnyEvent::F_SETFD, AnyEvent::FD_CLOEXEC;
		1625	fcntl $SIGPIPE_W, AnyEvent::F_SETFD, AnyEvent::FD_CLOEXEC;
1315	;	1626	}
1316	$asy->pipe_autodrain (0);
1317		1627
1318	$asy	1628	$SIGPIPE_R
		1629	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";
		1630
		1631	$SIG_IO = AE::io $SIGPIPE_R, 0, \&_signal_exec;
		1632	}
		1633
		1634	*signal = $HAVE_ASYNC_INTERRUPT
		1635	? sub {
		1636	my (undef, %arg) = @_;
		1637
		1638	# async::interrupt
		1639	my $signal = sig2num $arg{signal};
		1640	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
		1641
		1642	$SIG_ASY{$signal} ||= new Async::Interrupt
		1643	cb => sub { undef $SIG_EV{$signal} },
		1644	signal => $signal,
		1645	pipe => [$SIGPIPE_R->filenos],
		1646	pipe_autodrain => 0,
		1647	;
		1648
		1649	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
		1650	}
		1651	: sub {
		1652	my (undef, %arg) = @_;
		1653
		1654	# pure perl
		1655	my $signal = sig2name $arg{signal};
		1656	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
		1657
		1658	$SIG{$signal} ||= sub {
		1659	local $!;
		1660	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;
		1661	undef $SIG_EV{$signal};
		1662	};
		1663
		1664	# can't do signal processing without introducing races in pure perl,
		1665	# so limit the signal latency.
		1666	_sig_add;
		1667
		1668	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
		1669	}
		1670	;
		1671
		1672	*AnyEvent::Base::signal::DESTROY = sub {
		1673	my ($signal, $cb) = @{$_[0]};
		1674
		1675	_sig_del;
		1676
		1677	delete $SIG_CB{$signal}{$cb};
		1678
		1679	$HAVE_ASYNC_INTERRUPT
		1680	? delete $SIG_ASY{$signal}
		1681	: # delete doesn't work with older perls - they then
		1682	# print weird messages, or just unconditionally exit
		1683	# instead of getting the default action.
		1684	undef $SIG{$signal}
		1685	unless keys %{ $SIG_CB{$signal} };
1319	};	1686	};
1320		1687
1321	} else {	1688	*_signal_exec = sub {
1322	# pure perl	1689	$HAVE_ASYNC_INTERRUPT
		1690	? $SIGPIPE_R->drain
		1691	: sysread $SIGPIPE_R, (my $dummy), 9;
1323		1692
1324	$SIG{$signal} ||= sub {	1693	while (%SIG_EV) {
1325	local $!;	1694	for (keys %SIG_EV) {
1326	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;	1695	delete $SIG_EV{$_};
1327	undef $SIG_EV{$signal};	1696	&$_ for values %{ $SIG_CB{$_} || {} };
		1697	}
		1698	}
1328	};	1699	};
1329
1330	# can't do signal processing without introducing races in pure perl,
1331	# so limit the signal latency.
1332	_sig_add;
1333	}	1700	};
		1701	die if $@;
1334		1702
1335	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
1336	}
1337
1338	sub signal {
1339	# probe for availability of Async::Interrupt
1340	if (!$ENV{PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT} && eval "use Async::Interrupt 0.6 (); 1") {
1341	warn "AnyEvent: using Async::Interrupt for race-free signal handling.\n" if $VERBOSE >= 8;
1342
1343	$HAVE_ASYNC_INTERRUPT = 1;
1344	$SIGPIPE_R = new Async::Interrupt::EventPipe;
1345	$SIG_IO = AnyEvent->io (fh => $SIGPIPE_R->fileno, poll => "r", cb => \&_signal_exec);
1346
1347	} else {
1348	warn "AnyEvent: using emulated perl signal handling with latency timer.\n" if $VERBOSE >= 8;
1349
1350	require Fcntl;
1351
1352	if (AnyEvent::WIN32) {
1353	require AnyEvent::Util;
1354
1355	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
1356	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R) if $SIGPIPE_R;
1357	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W) if $SIGPIPE_W; # just in case
1358	} else {
1359	pipe $SIGPIPE_R, $SIGPIPE_W;
1360	fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R;
1361	fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case
1362
1363	# not strictly required, as $^F is normally 2, but let's make sure...
1364	fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
1365	fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
1366	}
1367
1368	$SIGPIPE_R
1369	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";
1370
1371	$SIG_IO = AnyEvent->io (fh => $SIGPIPE_R, poll => "r", cb => \&_signal_exec);
1372	}
1373
1374	*signal = \&_signal;
1375	&signal	1703	&signal
1376	}
1377
1378	sub AnyEvent::Base::signal::DESTROY {
1379	my ($signal, $cb) = @{$_[0]};
1380
1381	_sig_del;
1382
1383	delete $SIG_CB{$signal}{$cb};
1384
1385	$HAVE_ASYNC_INTERRUPT
1386	? delete $SIG_ASY{$signal}
1387	: # delete doesn't work with older perls - they then
1388	# print weird messages, or just unconditionally exit
1389	# instead of getting the default action.
1390	undef $SIG{$signal}
1391	unless keys %{ $SIG_CB{$signal} };
1392	}	1704	}
1393		1705
1394	# default implementation for ->child	1706	# default implementation for ->child
1395		1707
1396	our %PID_CB;	1708	our %PID_CB;
1397	our $CHLD_W;	1709	our $CHLD_W;
1398	our $CHLD_DELAY_W;	1710	our $CHLD_DELAY_W;
1399	our $WNOHANG;
1400		1711
1401	sub _sigchld {	1712	# used by many Impl's
1402	while (0 < (my $pid = waitpid -1, $WNOHANG)) {	1713	sub _emit_childstatus($$) {
1403	$_->($pid, $?)	1714	my (undef, $rpid, $rstatus) = @_;
		1715
		1716	$_->($rpid, $rstatus)
1404	for values %{ $PID_CB{$pid} || {} },	1717	for values %{ $PID_CB{$rpid} || {} },
1405	values %{ $PID_CB{0} || {} };	1718	values %{ $PID_CB{0} || {} };
1406	}
1407	}	1719	}
1408		1720
1409	sub child {	1721	sub child {
		1722	eval q{ # poor man's autoloading {}
		1723	*_sigchld = sub {
		1724	my $pid;
		1725
		1726	AnyEvent->_emit_childstatus ($pid, $?)
		1727	while ($pid = waitpid -1, WNOHANG) > 0;
		1728	};
		1729
		1730	*child = sub {
1410	my (undef, %arg) = @_;	1731	my (undef, %arg) = @_;
1411		1732
1412	defined (my $pid = $arg{pid} + 0)	1733	my $pid = $arg{pid};
1413	or Carp::croak "required option 'pid' is missing";	1734	my $cb = $arg{cb};
1414		1735
1415	$PID_CB{$pid}{$arg{cb}} = $arg{cb};	1736	$PID_CB{$pid}{$cb+0} = $cb;
1416		1737
1417	# WNOHANG is almost cetrainly 1 everywhere
1418	$WNOHANG ||= $^O =~ /^(?:openbsd|netbsd|linux|freebsd|cygwin|MSWin32)$/
1419	? 1
1420	: eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1;
1421
1422	unless ($CHLD_W) {	1738	unless ($CHLD_W) {
1423	$CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld);	1739	$CHLD_W = AE::signal CHLD => \&_sigchld;
1424	# child could be a zombie already, so make at least one round	1740	# child could be a zombie already, so make at least one round
1425	&_sigchld;	1741	&_sigchld;
1426	}	1742	}
1427		1743
1428	bless [$pid, $arg{cb}], "AnyEvent::Base::child"	1744	bless [$pid, $cb+0], "AnyEvent::Base::child"
1429	}	1745	};
1430		1746
1431	sub AnyEvent::Base::child::DESTROY {	1747	*AnyEvent::Base::child::DESTROY = sub {
1432	my ($pid, $cb) = @{$_[0]};	1748	my ($pid, $icb) = @{$_[0]};
1433		1749
1434	delete $PID_CB{$pid}{$cb};	1750	delete $PID_CB{$pid}{$icb};
1435	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };	1751	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };
1436		1752
1437	undef $CHLD_W unless keys %PID_CB;	1753	undef $CHLD_W unless keys %PID_CB;
		1754	};
		1755	};
		1756	die if $@;
		1757
		1758	&child
1438	}	1759	}
1439		1760
1440	# idle emulation is done by simply using a timer, regardless	1761	# idle emulation is done by simply using a timer, regardless
1441	# of whether the process is idle or not, and not letting	1762	# of whether the process is idle or not, and not letting
1442	# the callback use more than 50% of the time.	1763	# the callback use more than 50% of the time.
1443	sub idle {	1764	sub idle {
		1765	eval q{ # poor man's autoloading {}
		1766	*idle = sub {
1444	my (undef, %arg) = @_;	1767	my (undef, %arg) = @_;
1445		1768
1446	my ($cb, $w, $rcb) = $arg{cb};	1769	my ($cb, $w, $rcb) = $arg{cb};
1447		1770
1448	$rcb = sub {	1771	$rcb = sub {
1449	if ($cb) {	1772	if ($cb) {
1450	$w = _time;	1773	$w = _time;
1451	&$cb;	1774	&$cb;
1452	$w = _time - $w;	1775	$w = _time - $w;
1453		1776
1454	# never use more then 50% of the time for the idle watcher,	1777	# never use more then 50% of the time for the idle watcher,
1455	# within some limits	1778	# within some limits
1456	$w = 0.0001 if $w < 0.0001;	1779	$w = 0.0001 if $w < 0.0001;
1457	$w = 5 if $w > 5;	1780	$w = 5 if $w > 5;
1458		1781
1459	$w = AnyEvent->timer (after => $w, cb => $rcb);	1782	$w = AE::timer $w, 0, $rcb;
1460	} else {	1783	} else {
1461	# clean up...	1784	# clean up...
1462	undef $w;	1785	undef $w;
1463	undef $rcb;	1786	undef $rcb;
		1787	}
		1788	};
		1789
		1790	$w = AE::timer 0.05, 0, $rcb;
		1791
		1792	bless \\$cb, "AnyEvent::Base::idle"
1464	}	1793	};
		1794
		1795	*AnyEvent::Base::idle::DESTROY = sub {
		1796	undef $${$_[0]};
		1797	};
1465	};	1798	};
		1799	die if $@;
1466		1800
1467	$w = AnyEvent->timer (after => 0.05, cb => $rcb);	1801	&idle
1468
1469	bless \\$cb, "AnyEvent::Base::idle"
1470	}
1471
1472	sub AnyEvent::Base::idle::DESTROY {
1473	undef $${$_[0]};
1474	}	1802	}
1475		1803
1476	package AnyEvent::CondVar;	1804	package AnyEvent::CondVar;
1477		1805
1478	our @ISA = AnyEvent::CondVar::Base::;	1806	our @ISA = AnyEvent::CondVar::Base::;
		1807
		1808	# only to be used for subclassing
		1809	sub new {
		1810	my $class = shift;
		1811	bless AnyEvent->condvar (@_), $class
		1812	}
1479		1813
1480	package AnyEvent::CondVar::Base;	1814	package AnyEvent::CondVar::Base;
1481		1815
1482	#use overload	1816	#use overload
1483	# '&{}' => sub { my $self = shift; sub { $self->send (@_) } },	1817	# '&{}' => sub { my $self = shift; sub { $self->send (@_) } },
…		…
1493		1827
1494	sub _send {	1828	sub _send {
1495	# nop	1829	# nop
1496	}	1830	}
1497		1831
		1832	sub _wait {
		1833	AnyEvent->_poll until $_[0]{_ae_sent};
		1834	}
		1835
1498	sub send {	1836	sub send {
1499	my $cv = shift;	1837	my $cv = shift;
1500	$cv->{_ae_sent} = [@_];	1838	$cv->{_ae_sent} = [@_];
1501	(delete $cv->{_ae_cb})->($cv) if $cv->{_ae_cb};	1839	(delete $cv->{_ae_cb})->($cv) if $cv->{_ae_cb};
1502	$cv->_send;	1840	$cv->_send;
…		…
1509		1847
1510	sub ready {	1848	sub ready {
1511	$_[0]{_ae_sent}	1849	$_[0]{_ae_sent}
1512	}	1850	}
1513		1851
1514	sub _wait {
1515	$WAITING
1516	and !$_[0]{_ae_sent}
1517	and Carp::croak "AnyEvent::CondVar: recursive blocking wait detected";
1518
1519	local $WAITING = 1;
1520	AnyEvent->one_event while !$_[0]{_ae_sent};
1521	}
1522
1523	sub recv {	1852	sub recv {
		1853	unless ($_[0]{_ae_sent}) {
		1854	$WAITING
		1855	and Carp::croak "AnyEvent::CondVar: recursive blocking wait attempted";
		1856
		1857	local $WAITING = 1;
1524	$_[0]->_wait;	1858	$_[0]->_wait;
		1859	}
1525		1860
1526	Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak};	1861	$_[0]{_ae_croak}
1527	wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0]	1862	and Carp::croak $_[0]{_ae_croak};
		1863
		1864	wantarray
		1865	? @{ $_[0]{_ae_sent} }
		1866	: $_[0]{_ae_sent}[0]
1528	}	1867	}
1529		1868
1530	sub cb {	1869	sub cb {
1531	$_[0]{_ae_cb} = $_[1] if @_ > 1;	1870	my $cv = shift;
		1871
		1872	@_
		1873	and $cv->{_ae_cb} = shift
		1874	and $cv->{_ae_sent}
		1875	and (delete $cv->{_ae_cb})->($cv);
		1876
1532	$_[0]{_ae_cb}	1877	$cv->{_ae_cb}
1533	}	1878	}
1534		1879
1535	sub begin {	1880	sub begin {
1536	++$_[0]{_ae_counter};	1881	++$_[0]{_ae_counter};
1537	$_[0]{_ae_end_cb} = $_[1] if @_ > 1;	1882	$_[0]{_ae_end_cb} = $_[1] if @_ > 1;
…		…
1542	&{ $_[0]{_ae_end_cb} || sub { $_[0]->send } };	1887	&{ $_[0]{_ae_end_cb} || sub { $_[0]->send } };
1543	}	1888	}
1544		1889
1545	# undocumented/compatibility with pre-3.4	1890	# undocumented/compatibility with pre-3.4
1546	*broadcast = \&send;	1891	*broadcast = \&send;
1547	*wait = \&_wait;	1892	*wait = \&recv;
1548		1893
1549	=head1 ERROR AND EXCEPTION HANDLING	1894	=head1 ERROR AND EXCEPTION HANDLING
1550		1895
1551	In general, AnyEvent does not do any error handling - it relies on the	1896	In general, AnyEvent does not do any error handling - it relies on the
1552	caller to do that if required. The L<AnyEvent::Strict> module (see also	1897	caller to do that if required. The L<AnyEvent::Strict> module (see also
…		…
1599	check the arguments passed to most method calls. If it finds any problems,	1944	check the arguments passed to most method calls. If it finds any problems,
1600	it will croak.	1945	it will croak.
1601		1946
1602	In other words, enables "strict" mode.	1947	In other words, enables "strict" mode.
1603		1948
1604	Unlike C<use strict> (or it's modern cousin, C<< use L<common::sense>	1949	Unlike C<use strict> (or its modern cousin, C<< use L<common::sense>
1605	>>, it is definitely recommended to keep it off in production. Keeping	1950	>>, it is definitely recommended to keep it off in production. Keeping
1606	C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs	1951	C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs
1607	can be very useful, however.	1952	can be very useful, however.
1608		1953
1609	=item C<PERL_ANYEVENT_MODEL>	1954	=item C<PERL_ANYEVENT_MODEL>
1610		1955
1611	This can be used to specify the event model to be used by AnyEvent, before	1956	This can be used to specify the event model to be used by AnyEvent, before
1612	auto detection and -probing kicks in. It must be a string consisting	1957	auto detection and -probing kicks in.
1613	entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended	1958
		1959	It normally is a string consisting entirely of ASCII letters (e.g. C<EV>
		1960	or C<IOAsync>). The string C<AnyEvent::Impl::> gets prepended and the
1614	and the resulting module name is loaded and if the load was successful,	1961	resulting module name is loaded and - if the load was successful - used as
1615	used as event model. If it fails to load AnyEvent will proceed with	1962	event model backend. If it fails to load then AnyEvent will proceed with
1616	auto detection and -probing.	1963	auto detection and -probing.
1617		1964
1618	This functionality might change in future versions.	1965	If the string ends with C<::> instead (e.g. C<AnyEvent::Impl::EV::>) then
		1966	nothing gets prepended and the module name is used as-is (hint: C<::> at
		1967	the end of a string designates a module name and quotes it appropriately).
1619		1968
1620	For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you	1969	For example, to force the pure perl model (L<AnyEvent::Loop::Perl>) you
1621	could start your program like this:	1970	could start your program like this:
1622		1971
1623	PERL_ANYEVENT_MODEL=Perl perl ...	1972	PERL_ANYEVENT_MODEL=Perl perl ...
1624		1973
1625	=item C<PERL_ANYEVENT_PROTOCOLS>	1974	=item C<PERL_ANYEVENT_PROTOCOLS>
…		…
1746	warn "read: $input\n"; # output what has been read	2095	warn "read: $input\n"; # output what has been read
1747	$cv->send if $input =~ /^q/i; # quit program if /^q/i	2096	$cv->send if $input =~ /^q/i; # quit program if /^q/i
1748	},	2097	},
1749	);	2098	);
1750		2099
1751	my $time_watcher; # can only be used once
1752
1753	sub new_timer {
1754	$timer = AnyEvent->timer (after => 1, cb => sub {	2100	my $time_watcher = AnyEvent->timer (after => 1, interval => 1, cb => sub {
1755	warn "timeout\n"; # print 'timeout' about every second	2101	warn "timeout\n"; # print 'timeout' at most every second
1756	&new_timer; # and restart the time
1757	});	2102	});
1758	}
1759
1760	new_timer; # create first timer
1761		2103
1762	$cv->recv; # wait until user enters /^q/i	2104	$cv->recv; # wait until user enters /^q/i
1763		2105
1764	=head1 REAL-WORLD EXAMPLE	2106	=head1 REAL-WORLD EXAMPLE
1765		2107
…		…
1838		2180
1839	The actual code goes further and collects all errors (C<die>s, exceptions)	2181	The actual code goes further and collects all errors (C<die>s, exceptions)
1840	that occurred during request processing. The C<result> method detects	2182	that occurred during request processing. The C<result> method detects
1841	whether an exception as thrown (it is stored inside the $txn object)	2183	whether an exception as thrown (it is stored inside the $txn object)
1842	and just throws the exception, which means connection errors and other	2184	and just throws the exception, which means connection errors and other
1843	problems get reported tot he code that tries to use the result, not in a	2185	problems get reported to the code that tries to use the result, not in a
1844	random callback.	2186	random callback.
1845		2187
1846	All of this enables the following usage styles:	2188	All of this enables the following usage styles:
1847		2189
1848	1. Blocking:	2190	1. Blocking:
…		…
1896	through AnyEvent. The benchmark creates a lot of timers (with a zero	2238	through AnyEvent. The benchmark creates a lot of timers (with a zero
1897	timeout) and I/O watchers (watching STDOUT, a pty, to become writable,	2239	timeout) and I/O watchers (watching STDOUT, a pty, to become writable,
1898	which it is), lets them fire exactly once and destroys them again.	2240	which it is), lets them fire exactly once and destroys them again.
1899		2241
1900	Source code for this benchmark is found as F<eg/bench> in the AnyEvent	2242	Source code for this benchmark is found as F<eg/bench> in the AnyEvent
1901	distribution.	2243	distribution. It uses the L<AE> interface, which makes a real difference
		2244	for the EV and Perl backends only.
1902		2245
1903	=head3 Explanation of the columns	2246	=head3 Explanation of the columns
1904		2247
1905	I<watcher> is the number of event watchers created/destroyed. Since	2248	I<watcher> is the number of event watchers created/destroyed. Since
1906	different event models feature vastly different performances, each event	2249	different event models feature vastly different performances, each event
…		…
1927	watcher.	2270	watcher.
1928		2271
1929	=head3 Results	2272	=head3 Results
1930		2273
1931	name watchers bytes create invoke destroy comment	2274	name watchers bytes create invoke destroy comment
1932	EV/EV 400000 224 0.47 0.35 0.27 EV native interface	2275	EV/EV 100000 223 0.47 0.43 0.27 EV native interface
1933	EV/Any 100000 224 2.88 0.34 0.27 EV + AnyEvent watchers	2276	EV/Any 100000 223 0.48 0.42 0.26 EV + AnyEvent watchers
1934	CoroEV/Any 100000 224 2.85 0.35 0.28 coroutines + Coro::Signal	2277	Coro::EV/Any 100000 223 0.47 0.42 0.26 coroutines + Coro::Signal
1935	Perl/Any 100000 452 4.13 0.73 0.95 pure perl implementation	2278	Perl/Any 100000 431 2.70 0.74 0.92 pure perl implementation
1936	Event/Event 16000 517 32.20 31.80 0.81 Event native interface	2279	Event/Event 16000 516 31.16 31.84 0.82 Event native interface
1937	Event/Any 16000 590 35.85 31.55 1.06 Event + AnyEvent watchers	2280	Event/Any 16000 1203 42.61 34.79 1.80 Event + AnyEvent watchers
1938	IOAsync/Any 16000 989 38.10 32.77 11.13 via IO::Async::Loop::IO_Poll	2281	IOAsync/Any 16000 1911 41.92 27.45 16.81 via IO::Async::Loop::IO_Poll
1939	IOAsync/Any 16000 990 37.59 29.50 10.61 via IO::Async::Loop::Epoll	2282	IOAsync/Any 16000 1726 40.69 26.37 15.25 via IO::Async::Loop::Epoll
1940	Glib/Any 16000 1357 102.33 12.31 51.00 quadratic behaviour	2283	Glib/Any 16000 1118 89.00 12.57 51.17 quadratic behaviour
1941	Tk/Any 2000 1860 27.20 66.31 14.00 SEGV with >> 2000 watchers	2284	Tk/Any 2000 1346 20.96 10.75 8.00 SEGV with >> 2000 watchers
1942	POE/Event 2000 6328 109.99 751.67 14.02 via POE::Loop::Event	2285	POE/Any 2000 6951 108.97 795.32 14.24 via POE::Loop::Event
1943	POE/Select 2000 6027 94.54 809.13 579.80 via POE::Loop::Select	2286	POE/Any 2000 6648 94.79 774.40 575.51 via POE::Loop::Select
1944		2287
1945	=head3 Discussion	2288	=head3 Discussion
1946		2289
1947	The benchmark does I<not> measure scalability of the event loop very	2290	The benchmark does I<not> measure scalability of the event loop very
1948	well. For example, a select-based event loop (such as the pure perl one)	2291	well. For example, a select-based event loop (such as the pure perl one)
…		…
1960	benchmark machine, handling an event takes roughly 1600 CPU cycles with	2303	benchmark machine, handling an event takes roughly 1600 CPU cycles with
1961	EV, 3100 CPU cycles with AnyEvent's pure perl loop and almost 3000000 CPU	2304	EV, 3100 CPU cycles with AnyEvent's pure perl loop and almost 3000000 CPU
1962	cycles with POE.	2305	cycles with POE.
1963		2306
1964	C<EV> is the sole leader regarding speed and memory use, which are both	2307	C<EV> is the sole leader regarding speed and memory use, which are both
1965	maximal/minimal, respectively. Even when going through AnyEvent, it uses	2308	maximal/minimal, respectively. When using the L<AE> API there is zero
		2309	overhead (when going through the AnyEvent API create is about 5-6 times
		2310	slower, with other times being equal, so still uses far less memory than
1966	far less memory than any other event loop and is still faster than Event	2311	any other event loop and is still faster than Event natively).
1967	natively.
1968		2312
1969	The pure perl implementation is hit in a few sweet spots (both the	2313	The pure perl implementation is hit in a few sweet spots (both the
1970	constant timeout and the use of a single fd hit optimisations in the perl	2314	constant timeout and the use of a single fd hit optimisations in the perl
1971	interpreter and the backend itself). Nevertheless this shows that it	2315	interpreter and the backend itself). Nevertheless this shows that it
1972	adds very little overhead in itself. Like any select-based backend its	2316	adds very little overhead in itself. Like any select-based backend its
…		…
2046	In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100	2390	In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100
2047	(1%) are active. This mirrors the activity of large servers with many	2391	(1%) are active. This mirrors the activity of large servers with many
2048	connections, most of which are idle at any one point in time.	2392	connections, most of which are idle at any one point in time.
2049		2393
2050	Source code for this benchmark is found as F<eg/bench2> in the AnyEvent	2394	Source code for this benchmark is found as F<eg/bench2> in the AnyEvent
2051	distribution.	2395	distribution. It uses the L<AE> interface, which makes a real difference
		2396	for the EV and Perl backends only.
2052		2397
2053	=head3 Explanation of the columns	2398	=head3 Explanation of the columns
2054		2399
2055	I<sockets> is the number of sockets, and twice the number of "servers" (as	2400	I<sockets> is the number of sockets, and twice the number of "servers" (as
2056	each server has a read and write socket end).	2401	each server has a read and write socket end).
…		…
2064	a new one that moves the timeout into the future.	2409	a new one that moves the timeout into the future.
2065		2410
2066	=head3 Results	2411	=head3 Results
2067		2412
2068	name sockets create request	2413	name sockets create request
2069	EV 20000 69.01 11.16	2414	EV 20000 62.66 7.99
2070	Perl 20000 73.32 35.87	2415	Perl 20000 68.32 32.64
2071	IOAsync 20000 157.00 98.14 epoll	2416	IOAsync 20000 174.06 101.15 epoll
2072	IOAsync 20000 159.31 616.06 poll	2417	IOAsync 20000 174.67 610.84 poll
2073	Event 20000 212.62 257.32	2418	Event 20000 202.69 242.91
2074	Glib 20000 651.16 1896.30	2419	Glib 20000 557.01 1689.52
2075	POE 20000 349.67 12317.24 uses POE::Loop::Event	2420	POE 20000 341.54 12086.32 uses POE::Loop::Event
2076		2421
2077	=head3 Discussion	2422	=head3 Discussion
2078		2423
2079	This benchmark I<does> measure scalability and overall performance of the	2424	This benchmark I<does> measure scalability and overall performance of the
2080	particular event loop.	2425	particular event loop.
…		…
2206	As you can see, the AnyEvent + EV combination even beats the	2551	As you can see, the AnyEvent + EV combination even beats the
2207	hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl	2552	hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl
2208	backend easily beats IO::Lambda and POE.	2553	backend easily beats IO::Lambda and POE.
2209		2554
2210	And even the 100% non-blocking version written using the high-level (and	2555	And even the 100% non-blocking version written using the high-level (and
2211	slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda by a	2556	slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda
2212	large margin, even though it does all of DNS, tcp-connect and socket I/O	2557	higher level ("unoptimised") abstractions by a large margin, even though
2213	in a non-blocking way.	2558	it does all of DNS, tcp-connect and socket I/O in a non-blocking way.
2214		2559
2215	The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and	2560	The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and
2216	F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are	2561	F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are
2217	part of the IO::lambda distribution and were used without any changes.	2562	part of the IO::Lambda distribution and were used without any changes.
2218		2563
2219		2564
2220	=head1 SIGNALS	2565	=head1 SIGNALS
2221		2566
2222	AnyEvent currently installs handlers for these signals:	2567	AnyEvent currently installs handlers for these signals:
…		…
2259	unless defined $SIG{PIPE};	2604	unless defined $SIG{PIPE};
2260		2605
2261	=head1 RECOMMENDED/OPTIONAL MODULES	2606	=head1 RECOMMENDED/OPTIONAL MODULES
2262		2607
2263	One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and	2608	One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and
2264	it's built-in modules) are required to use it.	2609	its built-in modules) are required to use it.
2265		2610
2266	That does not mean that AnyEvent won't take advantage of some additional	2611	That does not mean that AnyEvent won't take advantage of some additional
2267	modules if they are installed.	2612	modules if they are installed.
2268		2613
2269	This section epxlains which additional modules will be used, and how they	2614	This section explains which additional modules will be used, and how they
2270	affect AnyEvent's operetion.	2615	affect AnyEvent's operation.
2271		2616
2272	=over 4	2617	=over 4
2273		2618
2274	=item L<Async::Interrupt>	2619	=item L<Async::Interrupt>
2275		2620
…		…
2280	catch the signals) with some delay (default is 10 seconds, look for	2625	catch the signals) with some delay (default is 10 seconds, look for
2281	C<$AnyEvent::MAX_SIGNAL_LATENCY>).	2626	C<$AnyEvent::MAX_SIGNAL_LATENCY>).
2282		2627
2283	If this module is available, then it will be used to implement signal	2628	If this module is available, then it will be used to implement signal
2284	catching, which means that signals will not be delayed, and the event loop	2629	catching, which means that signals will not be delayed, and the event loop
2285	will not be interrupted regularly, which is more efficient (And good for	2630	will not be interrupted regularly, which is more efficient (and good for
2286	battery life on laptops).	2631	battery life on laptops).
2287		2632
2288	This affects not just the pure-perl event loop, but also other event loops	2633	This affects not just the pure-perl event loop, but also other event loops
2289	that have no signal handling on their own (e.g. Glib, Tk, Qt).	2634	that have no signal handling on their own (e.g. Glib, Tk, Qt).
2290		2635
…		…
2302	automatic timer adjustments even when no monotonic clock is available,	2647	automatic timer adjustments even when no monotonic clock is available,
2303	can take avdantage of advanced kernel interfaces such as C<epoll> and	2648	can take avdantage of advanced kernel interfaces such as C<epoll> and
2304	C<kqueue>, and is the fastest backend I<by far>. You can even embed	2649	C<kqueue>, and is the fastest backend I<by far>. You can even embed
2305	L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>).	2650	L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>).
2306		2651
		2652	If you only use backends that rely on another event loop (e.g. C<Tk>),
		2653	then this module will do nothing for you.
		2654
2307	=item L<Guard>	2655	=item L<Guard>
2308		2656
2309	The guard module, when used, will be used to implement	2657	The guard module, when used, will be used to implement
2310	C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a	2658	C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a
2311	lot less memory), but otherwise doesn't affect guard operation much. It is	2659	lot less memory), but otherwise doesn't affect guard operation much. It is
2312	purely used for performance.	2660	purely used for performance.
2313		2661
2314	=item L<JSON> and L<JSON::XS>	2662	=item L<JSON> and L<JSON::XS>
2315		2663
2316	This module is required when you want to read or write JSON data via	2664	One of these modules is required when you want to read or write JSON data
2317	L<AnyEvent::Handle>. It is also written in pure-perl, but can take	2665	via L<AnyEvent::Handle>. L<JSON> is also written in pure-perl, but can take
2318	advantage of the ulta-high-speed L<JSON::XS> module when it is installed.	2666	advantage of the ultra-high-speed L<JSON::XS> module when it is installed.
2319
2320	In fact, L<AnyEvent::Handle> will use L<JSON::XS> by default if it is
2321	installed.
2322		2667
2323	=item L<Net::SSLeay>	2668	=item L<Net::SSLeay>
2324		2669
2325	Implementing TLS/SSL in Perl is certainly interesting, but not very	2670	Implementing TLS/SSL in Perl is certainly interesting, but not very
2326	worthwhile: If this module is installed, then L<AnyEvent::Handle> (with	2671	worthwhile: If this module is installed, then L<AnyEvent::Handle> (with
2327	the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL.	2672	the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL.
2328		2673
2329	=item L<Time::HiRes>	2674	=item L<Time::HiRes>
2330		2675
2331	This module is part of perl since release 5.008. It will be used when the	2676	This module is part of perl since release 5.008. It will be used when the
2332	chosen event library does not come with a timing source on it's own. The	2677	chosen event library does not come with a timing source of its own. The
2333	pure-perl event loop (L<AnyEvent::Impl::Perl>) will additionally use it to	2678	pure-perl event loop (L<AnyEvent::Loop>) will additionally load it to
2334	try to use a monotonic clock for timing stability.	2679	try to use a monotonic clock for timing stability.
2335		2680
2336	=back	2681	=back
2337		2682
2338		2683
2339	=head1 FORK	2684	=head1 FORK
2340		2685
2341	Most event libraries are not fork-safe. The ones who are usually are	2686	Most event libraries are not fork-safe. The ones who are usually are
2342	because they rely on inefficient but fork-safe C<select> or C<poll>	2687	because they rely on inefficient but fork-safe C<select> or C<poll> calls
2343	calls. Only L<EV> is fully fork-aware.	2688	- higher performance APIs such as BSD's kqueue or the dreaded Linux epoll
		2689	are usually badly thought-out hacks that are incompatible with fork in
		2690	one way or another. Only L<EV> is fully fork-aware and ensures that you
		2691	continue event-processing in both parent and child (or both, if you know
		2692	what you are doing).
		2693
		2694	This means that, in general, you cannot fork and do event processing in
		2695	the child if the event library was initialised before the fork (which
		2696	usually happens when the first AnyEvent watcher is created, or the library
		2697	is loaded).
2344		2698
2345	If you have to fork, you must either do so I<before> creating your first	2699	If you have to fork, you must either do so I<before> creating your first
2346	watcher OR you must not use AnyEvent at all in the child OR you must do	2700	watcher OR you must not use AnyEvent at all in the child OR you must do
2347	something completely out of the scope of AnyEvent.	2701	something completely out of the scope of AnyEvent.
		2702
		2703	The problem of doing event processing in the parent I<and> the child
		2704	is much more complicated: even for backends that I<are> fork-aware or
		2705	fork-safe, their behaviour is not usually what you want: fork clones all
		2706	watchers, that means all timers, I/O watchers etc. are active in both
		2707	parent and child, which is almost never what you want. USing C<exec>
		2708	to start worker children from some kind of manage rprocess is usually
		2709	preferred, because it is much easier and cleaner, at the expense of having
		2710	to have another binary.
2348		2711
2349		2712
2350	=head1 SECURITY CONSIDERATIONS	2713	=head1 SECURITY CONSIDERATIONS
2351		2714
2352	AnyEvent can be forced to load any event model via	2715	AnyEvent can be forced to load any event model via
…		…
2382	pronounced).	2745	pronounced).
2383		2746
2384		2747
2385	=head1 SEE ALSO	2748	=head1 SEE ALSO
2386		2749
		2750	Tutorial/Introduction: L<AnyEvent::Intro>.
		2751
		2752	FAQ: L<AnyEvent::FAQ>.
		2753
2387	Utility functions: L<AnyEvent::Util>.	2754	Utility functions: L<AnyEvent::Util>.
2388		2755
2389	Event modules: L<EV>, L<EV::Glib>, L<Glib::EV>, L<Event>, L<Glib::Event>,	2756	Event modules: L<AnyEvent::Loop>, L<EV>, L<EV::Glib>, L<Glib::EV>,
2390	L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.	2757	L<Event>, L<Glib::Event>, L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.
2391		2758
2392	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,	2759	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,
2393	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,	2760	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,
2394	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,	2761	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,
2395	L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>.	2762	L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>, L<Anyevent::Impl::Irssi>.
2396		2763
2397	Non-blocking file handles, sockets, TCP clients and	2764	Non-blocking file handles, sockets, TCP clients and
2398	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.	2765	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.
2399		2766
2400	Asynchronous DNS: L<AnyEvent::DNS>.	2767	Asynchronous DNS: L<AnyEvent::DNS>.
2401		2768
2402	Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>,	2769	Thread support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>.
2403	L<Coro::Event>,
2404		2770
2405	Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::XMPP>,	2771	Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::IRC>,
2406	L<AnyEvent::HTTP>.	2772	L<AnyEvent::HTTP>.
2407		2773
2408		2774
2409	=head1 AUTHOR	2775	=head1 AUTHOR
2410		2776

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