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Revision 1.409 by root, Thu Dec 6 12:10:09 2012 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	FLTK 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	$w = AnyEvent->signal (signal => <uppercase_signal_name>, cb => <callback>);
351		386
352	You can watch for signals using a signal watcher, C<signal> is the signal	387	You can watch for signals using a signal watcher, C<signal> is the signal
353	I<name> in uppercase and without any C<SIG> prefix, C<cb> is the Perl	388	I<name> in uppercase and without any C<SIG> prefix, C<cb> is the Perl
354	callback to be invoked whenever a signal occurs.	389	callback to be invoked whenever a signal occurs.
355		390
…		…
368		403
369	This watcher might use C<%SIG> (depending on the event loop used),	404	This watcher might use C<%SIG> (depending on the event loop used),
370	so programs overwriting those signals directly will likely not work	405	so programs overwriting those signals directly will likely not work
371	correctly.	406	correctly.
372		407
373	Also note that many event loops (e.g. Glib, Tk, Qt, IO::Async) do not
374	support attaching callbacks to signals, which is a pity, as you cannot do
375	race-free signal handling in perl. AnyEvent will try to do it's best, but
376	in some cases, signals will be delayed. The maximum time a signal might
377	be delayed is specified in C<$AnyEvent::MAX_SIGNAL_LATENCY> (default: 10
378	seconds). This variable can be changed only before the first signal
379	watcher is created, and should be left alone otherwise. Higher values
380	will cause fewer spurious wake-ups, which is better for power and CPU
381	saving. All these problems can be avoided by installing the optional
382	L<Async::Interrupt> module.
383
384	Example: exit on SIGINT	408	Example: exit on SIGINT
385		409
386	my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });	410	my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });
387		411
		412	=head3 Restart Behaviour
		413
		414	While restart behaviour is up to the event loop implementation, most will
		415	not restart syscalls (that includes L<Async::Interrupt> and AnyEvent's
		416	pure perl implementation).
		417
		418	=head3 Safe/Unsafe Signals
		419
		420	Perl signals can be either "safe" (synchronous to opcode handling)
		421	or "unsafe" (asynchronous) - the former might delay signal delivery
		422	indefinitely, the latter might corrupt your memory.
		423
		424	AnyEvent signal handlers are, in addition, synchronous to the event loop,
		425	i.e. they will not interrupt your running perl program but will only be
		426	called as part of the normal event handling (just like timer, I/O etc.
		427	callbacks, too).
		428
		429	=head3 Signal Races, Delays and Workarounds
		430
		431	Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support
		432	attaching callbacks to signals in a generic way, which is a pity,
		433	as you cannot do race-free signal handling in perl, requiring
		434	C libraries for this. AnyEvent will try to do its best, which
		435	means in some cases, signals will be delayed. The maximum time
		436	a signal might be delayed is 10 seconds by default, but can
		437	be overriden via C<$ENV{PERL_ANYEVENT_MAX_SIGNAL_LATENCY}> or
		438	C<$AnyEvent::MAX_SIGNAL_LATENCY> - see the L<ENVIRONMENT VARIABLES>
		439	section for details.
		440
		441	All these problems can be avoided by installing the optional
		442	L<Async::Interrupt> module, which works with most event loops. It will not
		443	work with inherently broken event loops such as L<Event> or L<Event::Lib>
		444	(and not with L<POE> currently). For those, you just have to suffer the
		445	delays.
		446
388	=head2 CHILD PROCESS WATCHERS	447	=head2 CHILD PROCESS WATCHERS
389		448
		449	$w = AnyEvent->child (pid => <process id>, cb => <callback>);
		450
390	You can also watch on a child process exit and catch its exit status.	451	You can also watch for a child process exit and catch its exit status.
391		452
392	The child process is specified by the C<pid> argument (if set to C<0>, it	453	The child process is specified by the C<pid> argument (on some backends,
393	watches for any child process exit). The watcher will triggered only when	454	using C<0> watches for any child process exit, on others this will
394	the child process has finished and an exit status is available, not on	455	croak). The watcher will be triggered only when the child process has
395	any trace events (stopped/continued).	456	finished and an exit status is available, not on any trace events
		457	(stopped/continued).
396		458
397	The callback will be called with the pid and exit status (as returned by	459	The callback will be called with the pid and exit status (as returned by
398	waitpid), so unlike other watcher types, you I<can> rely on child watcher	460	waitpid), so unlike other watcher types, you I<can> rely on child watcher
399	callback arguments.	461	callback arguments.
400		462
…		…
418	thing in an AnyEvent program, you I<have> to create at least one	480	thing in an AnyEvent program, you I<have> to create at least one
419	watcher before you C<fork> the child (alternatively, you can call	481	watcher before you C<fork> the child (alternatively, you can call
420	C<AnyEvent::detect>).	482	C<AnyEvent::detect>).
421		483
422	As most event loops do not support waiting for child events, they will be	484	As most event loops do not support waiting for child events, they will be
423	emulated by AnyEvent in most cases, in which the latency and race problems	485	emulated by AnyEvent in most cases, in which case the latency and race
424	mentioned in the description of signal watchers apply.	486	problems mentioned in the description of signal watchers apply.
425		487
426	Example: fork a process and wait for it	488	Example: fork a process and wait for it
427		489
428	my $done = AnyEvent->condvar;	490	my $done = AnyEvent->condvar;
429		491
…		…
441	# do something else, then wait for process exit	503	# do something else, then wait for process exit
442	$done->recv;	504	$done->recv;
443		505
444	=head2 IDLE WATCHERS	506	=head2 IDLE WATCHERS
445		507
446	Sometimes there is a need to do something, but it is not so important	508	$w = AnyEvent->idle (cb => <callback>);
447	to do it instantly, but only when there is nothing better to do. This
448	"nothing better to do" is usually defined to be "no other events need
449	attention by the event loop".
450		509
451	Idle watchers ideally get invoked when the event loop has nothing	510	This will repeatedly invoke the callback after the process becomes idle,
452	better to do, just before it would block the process to wait for new	511	until either the watcher is destroyed or new events have been detected.
453	events. Instead of blocking, the idle watcher is invoked.
454		512
455	Most event loops unfortunately do not really support idle watchers (only	513	Idle watchers are useful when there is a need to do something, but it
		514	is not so important (or wise) to do it instantly. The callback will be
		515	invoked only when there is "nothing better to do", which is usually
		516	defined as "all outstanding events have been handled and no new events
		517	have been detected". That means that idle watchers ideally get invoked
		518	when the event loop has just polled for new events but none have been
		519	detected. Instead of blocking to wait for more events, the idle watchers
		520	will be invoked.
		521
		522	Unfortunately, most event loops do not really support idle watchers (only
456	EV, Event and Glib do it in a usable fashion) - for the rest, AnyEvent	523	EV, Event and Glib do it in a usable fashion) - for the rest, AnyEvent
457	will simply call the callback "from time to time".	524	will simply call the callback "from time to time".
458		525
459	Example: read lines from STDIN, but only process them when the	526	Example: read lines from STDIN, but only process them when the
460	program is otherwise idle:	527	program is otherwise idle:
…		…
476	});	543	});
477	});	544	});
478		545
479	=head2 CONDITION VARIABLES	546	=head2 CONDITION VARIABLES
480		547
		548	$cv = AnyEvent->condvar;
		549
		550	$cv->send (<list>);
		551	my @res = $cv->recv;
		552
481	If you are familiar with some event loops you will know that all of them	553	If you are familiar with some event loops you will know that all of them
482	require you to run some blocking "loop", "run" or similar function that	554	require you to run some blocking "loop", "run" or similar function that
483	will actively watch for new events and call your callbacks.	555	will actively watch for new events and call your callbacks.
484		556
485	AnyEvent is slightly different: it expects somebody else to run the event	557	AnyEvent is slightly different: it expects somebody else to run the event
486	loop and will only block when necessary (usually when told by the user).	558	loop and will only block when necessary (usually when told by the user).
487		559
488	The instrument to do that is called a "condition variable", so called	560	The tool to do that is called a "condition variable", so called because
489	because they represent a condition that must become true.	561	they represent a condition that must become true.
490		562
491	Now is probably a good time to look at the examples further below.	563	Now is probably a good time to look at the examples further below.
492		564
493	Condition variables can be created by calling the C<< AnyEvent->condvar	565	Condition variables can be created by calling the C<< AnyEvent->condvar
494	>> method, usually without arguments. The only argument pair allowed is	566	>> method, usually without arguments. The only argument pair allowed is
…		…
499	After creation, the condition variable is "false" until it becomes "true"	571	After creation, the condition variable is "false" until it becomes "true"
500	by calling the C<send> method (or calling the condition variable as if it	572	by calling the C<send> method (or calling the condition variable as if it
501	were a callback, read about the caveats in the description for the C<<	573	were a callback, read about the caveats in the description for the C<<
502	->send >> method).	574	->send >> method).
503		575
504	Condition variables are similar to callbacks, except that you can	576	Since condition variables are the most complex part of the AnyEvent API, here are
505	optionally wait for them. They can also be called merge points - points	577	some different mental models of what they are - pick the ones you can connect to:
506	in time where multiple outstanding events have been processed. And yet	578
507	another way to call them is transactions - each condition variable can be	579	=over 4
508	used to represent a transaction, which finishes at some point and delivers	580
509	a result.	581	=item * Condition variables are like callbacks - you can call them (and pass them instead
		582	of callbacks). Unlike callbacks however, you can also wait for them to be called.
		583
		584	=item * Condition variables are signals - one side can emit or send them,
		585	the other side can wait for them, or install a handler that is called when
		586	the signal fires.
		587
		588	=item * Condition variables are like "Merge Points" - points in your program
		589	where you merge multiple independent results/control flows into one.
		590
		591	=item * Condition variables represent a transaction - functions that start
		592	some kind of transaction can return them, leaving the caller the choice
		593	between waiting in a blocking fashion, or setting a callback.
		594
		595	=item * Condition variables represent future values, or promises to deliver
		596	some result, long before the result is available.
		597
		598	=back
510		599
511	Condition variables are very useful to signal that something has finished,	600	Condition variables are very useful to signal that something has finished,
512	for example, if you write a module that does asynchronous http requests,	601	for example, if you write a module that does asynchronous http requests,
513	then a condition variable would be the ideal candidate to signal the	602	then a condition variable would be the ideal candidate to signal the
514	availability of results. The user can either act when the callback is	603	availability of results. The user can either act when the callback is
…		…
527		616
528	Condition variables are represented by hash refs in perl, and the keys	617	Condition variables are represented by hash refs in perl, and the keys
529	used by AnyEvent itself are all named C<_ae_XXX> to make subclassing	618	used by AnyEvent itself are all named C<_ae_XXX> to make subclassing
530	easy (it is often useful to build your own transaction class on top of	619	easy (it is often useful to build your own transaction class on top of
531	AnyEvent). To subclass, use C<AnyEvent::CondVar> as base class and call	620	AnyEvent). To subclass, use C<AnyEvent::CondVar> as base class and call
532	it's C<new> method in your own C<new> method.	621	its C<new> method in your own C<new> method.
533		622
534	There are two "sides" to a condition variable - the "producer side" which	623	There are two "sides" to a condition variable - the "producer side" which
535	eventually calls C<< -> send >>, and the "consumer side", which waits	624	eventually calls C<< -> send >>, and the "consumer side", which waits
536	for the send to occur.	625	for the send to occur.
537		626
538	Example: wait for a timer.	627	Example: wait for a timer.
539		628
540	# wait till the result is ready	629	# condition: "wait till the timer is fired"
541	my $result_ready = AnyEvent->condvar;	630	my $timer_fired = AnyEvent->condvar;
542		631
543	# do something such as adding a timer	632	# create the timer - we could wait for, say
544	# or socket watcher the calls $result_ready->send	633	# a handle becomign ready, or even an
545	# when the "result" is ready.	634	# AnyEvent::HTTP request to finish, but
546	# in this case, we simply use a timer:	635	# in this case, we simply use a timer:
547	my $w = AnyEvent->timer (	636	my $w = AnyEvent->timer (
548	after => 1,	637	after => 1,
549	cb => sub { $result_ready->send },	638	cb => sub { $timer_fired->send },
550	);	639	);
551		640
552	# this "blocks" (while handling events) till the callback	641	# this "blocks" (while handling events) till the callback
553	# calls -<send	642	# calls ->send
554	$result_ready->recv;	643	$timer_fired->recv;
555		644
556	Example: wait for a timer, but take advantage of the fact that condition	645	Example: wait for a timer, but take advantage of the fact that condition
557	variables are also callable directly.	646	variables are also callable directly.
558		647
559	my $done = AnyEvent->condvar;	648	my $done = AnyEvent->condvar;
…		…
602	they were a code reference). Calling them directly is the same as calling	691	they were a code reference). Calling them directly is the same as calling
603	C<send>.	692	C<send>.
604		693
605	=item $cv->croak ($error)	694	=item $cv->croak ($error)
606		695
607	Similar to send, but causes all call's to C<< ->recv >> to invoke	696	Similar to send, but causes all calls to C<< ->recv >> to invoke
608	C<Carp::croak> with the given error message/object/scalar.	697	C<Carp::croak> with the given error message/object/scalar.
609		698
610	This can be used to signal any errors to the condition variable	699	This can be used to signal any errors to the condition variable
611	user/consumer. Doing it this way instead of calling C<croak> directly	700	user/consumer. Doing it this way instead of calling C<croak> directly
612	delays the error detetcion, but has the overwhelmign advantage that it	701	delays the error detection, but has the overwhelming advantage that it
613	diagnoses the error at the place where the result is expected, and not	702	diagnoses the error at the place where the result is expected, and not
614	deep in some event clalback without connection to the actual code causing	703	deep in some event callback with no connection to the actual code causing
615	the problem.	704	the problem.
616		705
617	=item $cv->begin ([group callback])	706	=item $cv->begin ([group callback])
618		707
619	=item $cv->end	708	=item $cv->end
…		…
622	one. For example, a function that pings many hosts in parallel might want	711	one. For example, a function that pings many hosts in parallel might want
623	to use a condition variable for the whole process.	712	to use a condition variable for the whole process.
624		713
625	Every call to C<< ->begin >> will increment a counter, and every call to	714	Every call to C<< ->begin >> will increment a counter, and every call to
626	C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end	715	C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end
627	>>, the (last) callback passed to C<begin> will be executed. That callback	716	>>, the (last) callback passed to C<begin> will be executed, passing the
628	is I<supposed> to call C<< ->send >>, but that is not required. If no	717	condvar as first argument. That callback is I<supposed> to call C<< ->send
629	callback was set, C<send> will be called without any arguments.	718	>>, but that is not required. If no group callback was set, C<send> will
		719	be called without any arguments.
630		720
631	You can think of C<< $cv->send >> giving you an OR condition (one call	721	You can think of C<< $cv->send >> giving you an OR condition (one call
632	sends), while C<< $cv->begin >> and C<< $cv->end >> giving you an AND	722	sends), while C<< $cv->begin >> and C<< $cv->end >> giving you an AND
633	condition (all C<begin> calls must be C<end>'ed before the condvar sends).	723	condition (all C<begin> calls must be C<end>'ed before the condvar sends).
634		724
…		…
656	one call to C<begin>, so the condvar waits for all calls to C<end> before	746	one call to C<begin>, so the condvar waits for all calls to C<end> before
657	sending.	747	sending.
658		748
659	The ping example mentioned above is slightly more complicated, as the	749	The ping example mentioned above is slightly more complicated, as the
660	there are results to be passwd back, and the number of tasks that are	750	there are results to be passwd back, and the number of tasks that are
661	begung can potentially be zero:	751	begun can potentially be zero:
662		752
663	my $cv = AnyEvent->condvar;	753	my $cv = AnyEvent->condvar;
664		754
665	my %result;	755	my %result;
666	$cv->begin (sub { $cv->send (\%result) });	756	$cv->begin (sub { shift->send (\%result) });
667		757
668	for my $host (@list_of_hosts) {	758	for my $host (@list_of_hosts) {
669	$cv->begin;	759	$cv->begin;
670	ping_host_then_call_callback $host, sub {	760	ping_host_then_call_callback $host, sub {
671	$result{$host} = ...;	761	$result{$host} = ...;
…		…
673	};	763	};
674	}	764	}
675		765
676	$cv->end;	766	$cv->end;
677		767
		768	...
		769
		770	my $results = $cv->recv;
		771
678	This code fragment supposedly pings a number of hosts and calls	772	This code fragment supposedly pings a number of hosts and calls
679	C<send> after results for all then have have been gathered - in any	773	C<send> after results for all then have have been gathered - in any
680	order. To achieve this, the code issues a call to C<begin> when it starts	774	order. To achieve this, the code issues a call to C<begin> when it starts
681	each ping request and calls C<end> when it has received some result for	775	each ping request and calls C<end> when it has received some result for
682	it. Since C<begin> and C<end> only maintain a counter, the order in which	776	it. Since C<begin> and C<end> only maintain a counter, the order in which
…		…
687	to be called once the counter reaches C<0>, and second, it ensures that	781	to be called once the counter reaches C<0>, and second, it ensures that
688	C<send> is called even when C<no> hosts are being pinged (the loop	782	C<send> is called even when C<no> hosts are being pinged (the loop
689	doesn't execute once).	783	doesn't execute once).
690		784
691	This is the general pattern when you "fan out" into multiple (but	785	This is the general pattern when you "fan out" into multiple (but
692	potentially none) subrequests: use an outer C<begin>/C<end> pair to set	786	potentially zero) subrequests: use an outer C<begin>/C<end> pair to set
693	the callback and ensure C<end> is called at least once, and then, for each	787	the callback and ensure C<end> is called at least once, and then, for each
694	subrequest you start, call C<begin> and for each subrequest you finish,	788	subrequest you start, call C<begin> and for each subrequest you finish,
695	call C<end>.	789	call C<end>.
696		790
697	=back	791	=back
…		…
704	=over 4	798	=over 4
705		799
706	=item $cv->recv	800	=item $cv->recv
707		801
708	Wait (blocking if necessary) until the C<< ->send >> or C<< ->croak	802	Wait (blocking if necessary) until the C<< ->send >> or C<< ->croak
709	>> methods have been called on c<$cv>, while servicing other watchers	803	>> methods have been called on C<$cv>, while servicing other watchers
710	normally.	804	normally.
711		805
712	You can only wait once on a condition - additional calls are valid but	806	You can only wait once on a condition - additional calls are valid but
713	will return immediately.	807	will return immediately.
714		808
…		…
717		811
718	In list context, all parameters passed to C<send> will be returned,	812	In list context, all parameters passed to C<send> will be returned,
719	in scalar context only the first one will be returned.	813	in scalar context only the first one will be returned.
720		814
721	Note that doing a blocking wait in a callback is not supported by any	815	Note that doing a blocking wait in a callback is not supported by any
722	event loop, that is, recursive invocation of a blocking C<< ->recv	816	event loop, that is, recursive invocation of a blocking C<< ->recv >> is
723	>> is not allowed, and the C<recv> call will C<croak> if such a	817	not allowed and the C<recv> call will C<croak> if such a condition is
724	condition is detected. This condition can be slightly loosened by using	818	detected. This requirement can be dropped by relying on L<Coro::AnyEvent>
725	L<Coro::AnyEvent>, which allows you to do a blocking C<< ->recv >> from	819	, which allows you to do a blocking C<< ->recv >> from any thread
726	any thread that doesn't run the event loop itself.	820	that doesn't run the event loop itself. L<Coro::AnyEvent> is loaded
		821	automatically when L<Coro> is used with L<AnyEvent>, so code does not need
		822	to do anything special to take advantage of that: any code that would
		823	normally block your program because it calls C<recv>, be executed in an
		824	C<async> thread instead without blocking other threads.
727		825
728	Not all event models support a blocking wait - some die in that case	826	Not all event models support a blocking wait - some die in that case
729	(programs might want to do that to stay interactive), so I<if you are	827	(programs might want to do that to stay interactive), so I<if you are
730	using this from a module, never require a blocking wait>. Instead, let the	828	using this from a module, never require a blocking wait>. Instead, let the
731	caller decide whether the call will block or not (for example, by coupling	829	caller decide whether the call will block or not (for example, by coupling
732	condition variables with some kind of request results and supporting	830	condition variables with some kind of request results and supporting
733	callbacks so the caller knows that getting the result will not block,	831	callbacks so the caller knows that getting the result will not block,
734	while still supporting blocking waits if the caller so desires).	832	while still supporting blocking waits if the caller so desires).
735		833
736	You can ensure that C<< -recv >> never blocks by setting a callback and	834	You can ensure that C<< ->recv >> never blocks by setting a callback and
737	only calling C<< ->recv >> from within that callback (or at a later	835	only calling C<< ->recv >> from within that callback (or at a later
738	time). This will work even when the event loop does not support blocking	836	time). This will work even when the event loop does not support blocking
739	waits otherwise.	837	waits otherwise.
740		838
741	=item $bool = $cv->ready	839	=item $bool = $cv->ready
…		…
747		845
748	This is a mutator function that returns the callback set and optionally	846	This is a mutator function that returns the callback set and optionally
749	replaces it before doing so.	847	replaces it before doing so.
750		848
751	The callback will be called when the condition becomes "true", i.e. when	849	The callback will be called when the condition becomes "true", i.e. when
752	C<send> or C<croak> are called, with the only argument being the condition	850	C<send> or C<croak> are called, with the only argument being the
753	variable itself. Calling C<recv> inside the callback or at any later time	851	condition variable itself. If the condition is already true, the
754	is guaranteed not to block.	852	callback is called immediately when it is set. Calling C<recv> inside
		853	the callback or at any later time is guaranteed not to block.
755		854
756	=back	855	=back
757		856
758	=head1 SUPPORTED EVENT LOOPS/BACKENDS	857	=head1 SUPPORTED EVENT LOOPS/BACKENDS
759		858
…		…
762	=over 4	861	=over 4
763		862
764	=item Backends that are autoprobed when no other event loop can be found.	863	=item Backends that are autoprobed when no other event loop can be found.
765		864
766	EV is the preferred backend when no other event loop seems to be in	865	EV is the preferred backend when no other event loop seems to be in
767	use. If EV is not installed, then AnyEvent will try Event, and, failing	866	use. If EV is not installed, then AnyEvent will fall back to its own
768	that, will fall back to its own pure-perl implementation, which is	867	pure-perl implementation, which is available everywhere as it comes with
769	available everywhere as it comes with AnyEvent itself.	868	AnyEvent itself.
770		869
771	AnyEvent::Impl::EV based on EV (interface to libev, best choice).	870	AnyEvent::Impl::EV based on EV (interface to libev, best choice).
772	AnyEvent::Impl::Event based on Event, very stable, few glitches.
773	AnyEvent::Impl::Perl pure-perl implementation, fast and portable.	871	AnyEvent::Impl::Perl pure-perl AnyEvent::Loop, fast and portable.
774		872
775	=item Backends that are transparently being picked up when they are used.	873	=item Backends that are transparently being picked up when they are used.
776		874
777	These will be used when they are currently loaded when the first watcher	875	These will be used if they are already loaded when the first watcher
778	is created, in which case it is assumed that the application is using	876	is created, in which case it is assumed that the application is using
779	them. This means that AnyEvent will automatically pick the right backend	877	them. This means that AnyEvent will automatically pick the right backend
780	when the main program loads an event module before anything starts to	878	when the main program loads an event module before anything starts to
781	create watchers. Nothing special needs to be done by the main program.	879	create watchers. Nothing special needs to be done by the main program.
782		880
		881	AnyEvent::Impl::Event based on Event, very stable, few glitches.
783	AnyEvent::Impl::Glib based on Glib, slow but very stable.	882	AnyEvent::Impl::Glib based on Glib, slow but very stable.
784	AnyEvent::Impl::Tk based on Tk, very broken.	883	AnyEvent::Impl::Tk based on Tk, very broken.
785	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.	884	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
786	AnyEvent::Impl::POE based on POE, very slow, some limitations.	885	AnyEvent::Impl::POE based on POE, very slow, some limitations.
		886	AnyEvent::Impl::Irssi used when running within irssi.
		887	AnyEvent::Impl::IOAsync based on IO::Async.
		888	AnyEvent::Impl::Cocoa based on Cocoa::EventLoop.
		889	AnyEvent::Impl::FLTK based on FLTK (fltk 2 binding).
787		890
788	=item Backends with special needs.	891	=item Backends with special needs.
789		892
790	Qt requires the Qt::Application to be instantiated first, but will	893	Qt requires the Qt::Application to be instantiated first, but will
791	otherwise be picked up automatically. As long as the main program	894	otherwise be picked up automatically. As long as the main program
792	instantiates the application before any AnyEvent watchers are created,	895	instantiates the application before any AnyEvent watchers are created,
793	everything should just work.	896	everything should just work.
794		897
795	AnyEvent::Impl::Qt based on Qt.	898	AnyEvent::Impl::Qt based on Qt.
796		899
797	Support for IO::Async can only be partial, as it is too broken and
798	architecturally limited to even support the AnyEvent API. It also
799	is the only event loop that needs the loop to be set explicitly, so
800	it can only be used by a main program knowing about AnyEvent. See
801	L<AnyEvent::Impl::Async> for the gory details.
802
803	AnyEvent::Impl::IOAsync based on IO::Async, cannot be autoprobed.
804
805	=item Event loops that are indirectly supported via other backends.	900	=item Event loops that are indirectly supported via other backends.
806		901
807	Some event loops can be supported via other modules:	902	Some event loops can be supported via other modules:
808		903
809	There is no direct support for WxWidgets (L<Wx>) or L<Prima>.	904	There is no direct support for WxWidgets (L<Wx>) or L<Prima>.
…		…
834	Contains C<undef> until the first watcher is being created, before the	929	Contains C<undef> until the first watcher is being created, before the
835	backend has been autodetected.	930	backend has been autodetected.
836		931
837	Afterwards it contains the event model that is being used, which is the	932	Afterwards it contains the event model that is being used, which is the
838	name of the Perl class implementing the model. This class is usually one	933	name of the Perl class implementing the model. This class is usually one
839	of the C<AnyEvent::Impl:xxx> modules, but can be any other class in the	934	of the C<AnyEvent::Impl::xxx> modules, but can be any other class in the
840	case AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode> it	935	case AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode> it
841	will be C<urxvt::anyevent>).	936	will be C<urxvt::anyevent>).
842		937
843	=item AnyEvent::detect	938	=item AnyEvent::detect
844		939
845	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model	940	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model
846	if necessary. You should only call this function right before you would	941	if necessary. You should only call this function right before you would
847	have created an AnyEvent watcher anyway, that is, as late as possible at	942	have created an AnyEvent watcher anyway, that is, as late as possible at
848	runtime, and not e.g. while initialising of your module.	943	runtime, and not e.g. during initialisation of your module.
		944
		945	The effect of calling this function is as if a watcher had been created
		946	(specifically, actions that happen "when the first watcher is created"
		947	happen when calling detetc as well).
849		948
850	If you need to do some initialisation before AnyEvent watchers are	949	If you need to do some initialisation before AnyEvent watchers are
851	created, use C<post_detect>.	950	created, use C<post_detect>.
852		951
853	=item $guard = AnyEvent::post_detect { BLOCK }	952	=item $guard = AnyEvent::post_detect { BLOCK }
854		953
855	Arranges for the code block to be executed as soon as the event model is	954	Arranges for the code block to be executed as soon as the event model is
856	autodetected (or immediately if this has already happened).	955	autodetected (or immediately if that has already happened).
857		956
858	The block will be executed I<after> the actual backend has been detected	957	The block will be executed I<after> the actual backend has been detected
859	(C<$AnyEvent::MODEL> is set), but I<before> any watchers have been	958	(C<$AnyEvent::MODEL> is set), but I<before> any watchers have been
860	created, so it is possible to e.g. patch C<@AnyEvent::ISA> or do	959	created, so it is possible to e.g. patch C<@AnyEvent::ISA> or do
861	other initialisations - see the sources of L<AnyEvent::Strict> or	960	other initialisations - see the sources of L<AnyEvent::Strict> or
…		…
865	event module detection too early, for example, L<AnyEvent::AIO> creates	964	event module detection too early, for example, L<AnyEvent::AIO> creates
866	and installs the global L<IO::AIO> watcher in a C<post_detect> block to	965	and installs the global L<IO::AIO> watcher in a C<post_detect> block to
867	avoid autodetecting the event module at load time.	966	avoid autodetecting the event module at load time.
868		967
869	If called in scalar or list context, then it creates and returns an object	968	If called in scalar or list context, then it creates and returns an object
870	that automatically removes the callback again when it is destroyed. See	969	that automatically removes the callback again when it is destroyed (or
		970	C<undef> when the hook was immediately executed). See L<AnyEvent::AIO> for
871	L<Coro::BDB> for a case where this is useful.	971	a case where this is useful.
		972
		973	Example: Create a watcher for the IO::AIO module and store it in
		974	C<$WATCHER>, but do so only do so after the event loop is initialised.
		975
		976	our WATCHER;
		977
		978	my $guard = AnyEvent::post_detect {
		979	$WATCHER = AnyEvent->io (fh => IO::AIO::poll_fileno, poll => 'r', cb => \&IO::AIO::poll_cb);
		980	};
		981
		982	# the ||= is important in case post_detect immediately runs the block,
		983	# as to not clobber the newly-created watcher. assigning both watcher and
		984	# post_detect guard to the same variable has the advantage of users being
		985	# able to just C<undef $WATCHER> if the watcher causes them grief.
		986
		987	$WATCHER ||= $guard;
872		988
873	=item @AnyEvent::post_detect	989	=item @AnyEvent::post_detect
874		990
875	If there are any code references in this array (you can C<push> to it	991	If there are any code references in this array (you can C<push> to it
876	before or after loading AnyEvent), then they will called directly after	992	before or after loading AnyEvent), then they will be called directly
877	the event loop has been chosen.	993	after the event loop has been chosen.
878		994
879	You should check C<$AnyEvent::MODEL> before adding to this array, though:	995	You should check C<$AnyEvent::MODEL> before adding to this array, though:
880	if it is defined then the event loop has already been detected, and the	996	if it is defined then the event loop has already been detected, and the
881	array will be ignored.	997	array will be ignored.
882		998
883	Best use C<AnyEvent::post_detect { BLOCK }> when your application allows	999	Best use C<AnyEvent::post_detect { BLOCK }> when your application allows
884	it,as it takes care of these details.	1000	it, as it takes care of these details.
885		1001
886	This variable is mainly useful for modules that can do something useful	1002	This variable is mainly useful for modules that can do something useful
887	when AnyEvent is used and thus want to know when it is initialised, but do	1003	when AnyEvent is used and thus want to know when it is initialised, but do
888	not need to even load it by default. This array provides the means to hook	1004	not need to even load it by default. This array provides the means to hook
889	into AnyEvent passively, without loading it.	1005	into AnyEvent passively, without loading it.
890		1006
		1007	Example: To load Coro::AnyEvent whenever Coro and AnyEvent are used
		1008	together, you could put this into Coro (this is the actual code used by
		1009	Coro to accomplish this):
		1010
		1011	if (defined $AnyEvent::MODEL) {
		1012	# AnyEvent already initialised, so load Coro::AnyEvent
		1013	require Coro::AnyEvent;
		1014	} else {
		1015	# AnyEvent not yet initialised, so make sure to load Coro::AnyEvent
		1016	# as soon as it is
		1017	push @AnyEvent::post_detect, sub { require Coro::AnyEvent };
		1018	}
		1019
		1020	=item AnyEvent::postpone { BLOCK }
		1021
		1022	Arranges for the block to be executed as soon as possible, but not before
		1023	the call itself returns. In practise, the block will be executed just
		1024	before the event loop polls for new events, or shortly afterwards.
		1025
		1026	This function never returns anything (to make the C<return postpone { ...
		1027	}> idiom more useful.
		1028
		1029	To understand the usefulness of this function, consider a function that
		1030	asynchronously does something for you and returns some transaction
		1031	object or guard to let you cancel the operation. For example,
		1032	C<AnyEvent::Socket::tcp_connect>:
		1033
		1034	# start a conenction attempt unless one is active
		1035	$self->{connect_guard} ||= AnyEvent::Socket::tcp_connect "www.example.net", 80, sub {
		1036	delete $self->{connect_guard};
		1037	...
		1038	};
		1039
		1040	Imagine that this function could instantly call the callback, for
		1041	example, because it detects an obvious error such as a negative port
		1042	number. Invoking the callback before the function returns causes problems
		1043	however: the callback will be called and will try to delete the guard
		1044	object. But since the function hasn't returned yet, there is nothing to
		1045	delete. When the function eventually returns it will assign the guard
		1046	object to C<< $self->{connect_guard} >>, where it will likely never be
		1047	deleted, so the program thinks it is still trying to connect.
		1048
		1049	This is where C<AnyEvent::postpone> should be used. Instead of calling the
		1050	callback directly on error:
		1051
		1052	$cb->(undef), return # signal error to callback, BAD!
		1053	if $some_error_condition;
		1054
		1055	It should use C<postpone>:
		1056
		1057	AnyEvent::postpone { $cb->(undef) }, return # signal error to callback, later
		1058	if $some_error_condition;
		1059
		1060	=item AnyEvent::log $level, $msg[, @args]
		1061
		1062	Log the given C<$msg> at the given C<$level>.
		1063
		1064	If L<AnyEvent::Log> is not loaded then this function makes a simple test
		1065	to see whether the message will be logged. If the test succeeds it will
		1066	load AnyEvent::Log and call C<AnyEvent::Log::log> - consequently, look at
		1067	the L<AnyEvent::Log> documentation for details.
		1068
		1069	If the test fails it will simply return. Right now this happens when a
		1070	numerical loglevel is used and it is larger than the level specified via
		1071	C<$ENV{PERL_ANYEVENT_VERBOSE}>.
		1072
		1073	If you want to sprinkle loads of logging calls around your code, consider
		1074	creating a logger callback with the C<AnyEvent::Log::logger> function,
		1075	which can reduce typing, codesize and can reduce the logging overhead
		1076	enourmously.
		1077
891	=back	1078	=back
892		1079
893	=head1 WHAT TO DO IN A MODULE	1080	=head1 WHAT TO DO IN A MODULE
894		1081
895	As a module author, you should C<use AnyEvent> and call AnyEvent methods	1082	As a module author, you should C<use AnyEvent> and call AnyEvent methods
…		…
905	because it will stall the whole program, and the whole point of using	1092	because it will stall the whole program, and the whole point of using
906	events is to stay interactive.	1093	events is to stay interactive.
907		1094
908	It is fine, however, to call C<< ->recv >> when the user of your module	1095	It is fine, however, to call C<< ->recv >> when the user of your module
909	requests it (i.e. if you create a http request object ad have a method	1096	requests it (i.e. if you create a http request object ad have a method
910	called C<results> that returns the results, it should call C<< ->recv >>	1097	called C<results> that returns the results, it may call C<< ->recv >>
911	freely, as the user of your module knows what she is doing. always).	1098	freely, as the user of your module knows what she is doing. Always).
912		1099
913	=head1 WHAT TO DO IN THE MAIN PROGRAM	1100	=head1 WHAT TO DO IN THE MAIN PROGRAM
914		1101
915	There will always be a single main program - the only place that should	1102	There will always be a single main program - the only place that should
916	dictate which event model to use.	1103	dictate which event model to use.
917		1104
918	If it doesn't care, it can just "use AnyEvent" and use it itself, or not	1105	If the program is not event-based, it need not do anything special, even
919	do anything special (it does not need to be event-based) and let AnyEvent	1106	when it depends on a module that uses an AnyEvent. If the program itself
920	decide which implementation to chose if some module relies on it.	1107	uses AnyEvent, but does not care which event loop is used, all it needs
		1108	to do is C<use AnyEvent>. In either case, AnyEvent will choose the best
		1109	available loop implementation.
921		1110
922	If the main program relies on a specific event model - for example, in	1111	If the main program relies on a specific event model - for example, in
923	Gtk2 programs you have to rely on the Glib module - you should load the	1112	Gtk2 programs you have to rely on the Glib module - you should load the
924	event module before loading AnyEvent or any module that uses it: generally	1113	event module before loading AnyEvent or any module that uses it: generally
925	speaking, you should load it as early as possible. The reason is that	1114	speaking, you should load it as early as possible. The reason is that
926	modules might create watchers when they are loaded, and AnyEvent will	1115	modules might create watchers when they are loaded, and AnyEvent will
927	decide on the event model to use as soon as it creates watchers, and it	1116	decide on the event model to use as soon as it creates watchers, and it
928	might chose the wrong one unless you load the correct one yourself.	1117	might choose the wrong one unless you load the correct one yourself.
929		1118
930	You can chose to use a pure-perl implementation by loading the	1119	You can chose to use a pure-perl implementation by loading the
931	C<AnyEvent::Impl::Perl> module, which gives you similar behaviour	1120	C<AnyEvent::Loop> module, which gives you similar behaviour
932	everywhere, but letting AnyEvent chose the model is generally better.	1121	everywhere, but letting AnyEvent chose the model is generally better.
933		1122
934	=head2 MAINLOOP EMULATION	1123	=head2 MAINLOOP EMULATION
935		1124
936	Sometimes (often for short test scripts, or even standalone programs who	1125	Sometimes (often for short test scripts, or even standalone programs who
…		…
949		1138
950		1139
951	=head1 OTHER MODULES	1140	=head1 OTHER MODULES
952		1141
953	The following is a non-exhaustive list of additional modules that use	1142	The following is a non-exhaustive list of additional modules that use
954	AnyEvent as a client and can therefore be mixed easily with other AnyEvent	1143	AnyEvent as a client and can therefore be mixed easily with other
955	modules and other event loops in the same program. Some of the modules	1144	AnyEvent modules and other event loops in the same program. Some of the
956	come with AnyEvent, most are available via CPAN.	1145	modules come as part of AnyEvent, the others are available via CPAN (see
		1146	L<http://search.cpan.org/search?m=module&q=anyevent%3A%3A*> for
		1147	a longer non-exhaustive list), and the list is heavily biased towards
		1148	modules of the AnyEvent author himself :)
957		1149
958	=over 4	1150	=over 4
959		1151
960	=item L<AnyEvent::Util>	1152	=item L<AnyEvent::Util>
961		1153
962	Contains various utility functions that replace often-used but blocking	1154	Contains various utility functions that replace often-used blocking
963	functions such as C<inet_aton> by event-/callback-based versions.	1155	functions such as C<inet_aton> with event/callback-based versions.
964		1156
965	=item L<AnyEvent::Socket>	1157	=item L<AnyEvent::Socket>
966		1158
967	Provides various utility functions for (internet protocol) sockets,	1159	Provides various utility functions for (internet protocol) sockets,
968	addresses and name resolution. Also functions to create non-blocking tcp	1160	addresses and name resolution. Also functions to create non-blocking tcp
…		…
970		1162
971	=item L<AnyEvent::Handle>	1163	=item L<AnyEvent::Handle>
972		1164
973	Provide read and write buffers, manages watchers for reads and writes,	1165	Provide read and write buffers, manages watchers for reads and writes,
974	supports raw and formatted I/O, I/O queued and fully transparent and	1166	supports raw and formatted I/O, I/O queued and fully transparent and
975	non-blocking SSL/TLS (via L<AnyEvent::TLS>.	1167	non-blocking SSL/TLS (via L<AnyEvent::TLS>).
976		1168
977	=item L<AnyEvent::DNS>	1169	=item L<AnyEvent::DNS>
978		1170
979	Provides rich asynchronous DNS resolver capabilities.	1171	Provides rich asynchronous DNS resolver capabilities.
980		1172
		1173	=item L<AnyEvent::HTTP>, L<AnyEvent::IRC>, L<AnyEvent::XMPP>, L<AnyEvent::GPSD>, L<AnyEvent::IGS>, L<AnyEvent::FCP>
		1174
		1175	Implement event-based interfaces to the protocols of the same name (for
		1176	the curious, IGS is the International Go Server and FCP is the Freenet
		1177	Client Protocol).
		1178
981	=item L<AnyEvent::HTTP>	1179	=item L<AnyEvent::AIO>
982		1180
983	A simple-to-use HTTP library that is capable of making a lot of concurrent	1181	Truly asynchronous (as opposed to non-blocking) I/O, should be in the
984	HTTP requests.	1182	toolbox of every event programmer. AnyEvent::AIO transparently fuses
		1183	L<IO::AIO> and AnyEvent together, giving AnyEvent access to event-based
		1184	file I/O, and much more.
		1185
		1186	=item L<AnyEvent::Filesys::Notify>
		1187
		1188	AnyEvent is good for non-blocking stuff, but it can't detect file or
		1189	path changes (e.g. "watch this directory for new files", "watch this
		1190	file for changes"). The L<AnyEvent::Filesys::Notify> module promises to
		1191	do just that in a portbale fashion, supporting inotify on GNU/Linux and
		1192	some weird, without doubt broken, stuff on OS X to monitor files. It can
		1193	fall back to blocking scans at regular intervals transparently on other
		1194	platforms, so it's about as portable as it gets.
		1195
		1196	(I haven't used it myself, but I haven't heard anybody complaining about
		1197	it yet).
		1198
		1199	=item L<AnyEvent::DBI>
		1200
		1201	Executes L<DBI> requests asynchronously in a proxy process for you,
		1202	notifying you in an event-based way when the operation is finished.
985		1203
986	=item L<AnyEvent::HTTPD>	1204	=item L<AnyEvent::HTTPD>
987		1205
988	Provides a simple web application server framework.	1206	A simple embedded webserver.
989		1207
990	=item L<AnyEvent::FastPing>	1208	=item L<AnyEvent::FastPing>
991		1209
992	The fastest ping in the west.	1210	The fastest ping in the west.
993		1211
994	=item L<AnyEvent::DBI>
995
996	Executes L<DBI> requests asynchronously in a proxy process.
997
998	=item L<AnyEvent::AIO>
999
1000	Truly asynchronous I/O, should be in the toolbox of every event
1001	programmer. AnyEvent::AIO transparently fuses L<IO::AIO> and AnyEvent
1002	together.
1003
1004	=item L<AnyEvent::BDB>
1005
1006	Truly asynchronous Berkeley DB access. AnyEvent::BDB transparently fuses
1007	L<BDB> and AnyEvent together.
1008
1009	=item L<AnyEvent::GPSD>
1010
1011	A non-blocking interface to gpsd, a daemon delivering GPS information.
1012
1013	=item L<AnyEvent::IRC>
1014
1015	AnyEvent based IRC client module family (replacing the older Net::IRC3).
1016
1017	=item L<AnyEvent::XMPP>
1018
1019	AnyEvent based XMPP (Jabber protocol) module family (replacing the older
1020	Net::XMPP2>.
1021
1022	=item L<AnyEvent::IGS>
1023
1024	A non-blocking interface to the Internet Go Server protocol (used by
1025	L<App::IGS>).
1026
1027	=item L<Net::FCP>
1028
1029	AnyEvent-based implementation of the Freenet Client Protocol, birthplace
1030	of AnyEvent.
1031
1032	=item L<Event::ExecFlow>
1033
1034	High level API for event-based execution flow control.
1035
1036	=item L<Coro>	1212	=item L<Coro>
1037		1213
1038	Has special support for AnyEvent via L<Coro::AnyEvent>.	1214	Has special support for AnyEvent via L<Coro::AnyEvent>, which allows you
		1215	to simply invert the flow control - don't call us, we will call you:
		1216
		1217	async {
		1218	Coro::AnyEvent::sleep 5; # creates a 5s timer and waits for it
		1219	print "5 seconds later!\n";
		1220
		1221	Coro::AnyEvent::readable *STDIN; # uses an I/O watcher
		1222	my $line = <STDIN>; # works for ttys
		1223
		1224	AnyEvent::HTTP::http_get "url", Coro::rouse_cb;
		1225	my ($body, $hdr) = Coro::rouse_wait;
		1226	};
1039		1227
1040	=back	1228	=back
1041		1229
1042	=cut	1230	=cut
1043		1231
1044	package AnyEvent;	1232	package AnyEvent;
1045		1233
1046	# basically a tuned-down version of common::sense	1234	# basically a tuned-down version of common::sense
1047	sub common_sense {	1235	sub common_sense {
1048	# no warnings	1236	# from common:.sense 3.5
1049	${^WARNING_BITS} ^= ${^WARNING_BITS};	1237	local $^W;
1050	# use strict vars subs	1238	${^WARNING_BITS} ^= ${^WARNING_BITS} ^ "\x3c\x3f\x33\x00\x0f\xf0\x0f\xc0\xf0\xfc\x33\x00";
		1239	# use strict vars subs - NO UTF-8, as Util.pm doesn't like this atm. (uts46data.pl)
1051	$^H |= 0x00000600;	1240	$^H |= 0x00000600;
1052	}	1241	}
1053		1242
1054	BEGIN { AnyEvent::common_sense }	1243	BEGIN { AnyEvent::common_sense }
1055		1244
1056	use Carp ();	1245	use Carp ();
1057		1246
1058	our $VERSION = 4.85;	1247	our $VERSION = '7.04';
1059	our $MODEL;	1248	our $MODEL;
1060
1061	our $AUTOLOAD;
1062	our @ISA;	1249	our @ISA;
1063
1064	our @REGISTRY;	1250	our @REGISTRY;
1065
1066	our $WIN32;
1067
1068	our $VERBOSE;	1251	our $VERBOSE;
		1252	our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred
		1253	our $MAX_SIGNAL_LATENCY = $ENV{PERL_ANYEVENT_MAX_SIGNAL_LATENCY} || 10; # executes after the BEGIN block below (tainting!)
1069		1254
1070	BEGIN {	1255	BEGIN {
1071	eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }";	1256	require "AnyEvent/constants.pl";
		1257
1072	eval "sub TAINT(){ " . (${^TAINT}*1) . " }";	1258	eval "sub TAINT (){" . (${^TAINT}*1) . "}";
1073		1259
1074	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}	1260	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}
1075	if ${^TAINT};	1261	if ${^TAINT};
1076		1262
1077	$VERBOSE = $ENV{PERL_ANYEVENT_VERBOSE}*1;	1263	$ENV{"PERL_ANYEVENT_$_"} = $ENV{"AE_$_"}
		1264	for grep s/^AE_// && !exists $ENV{"PERL_ANYEVENT_$_"}, keys %ENV;
1078		1265
1079	}	1266	@ENV{grep /^PERL_ANYEVENT_/, keys %ENV} = ()
		1267	if ${^TAINT};
1080		1268
1081	our $MAX_SIGNAL_LATENCY = 10;	1269	# $ENV{PERL_ANYEVENT_xxx} now valid
1082		1270
1083	our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred	1271	$VERBOSE = length $ENV{PERL_ANYEVENT_VERBOSE} ? $ENV{PERL_ANYEVENT_VERBOSE}*1 : 4;
1084		1272
1085	{
1086	my $idx;	1273	my $idx;
1087	$PROTOCOL{$_} = ++$idx	1274	$PROTOCOL{$_} = ++$idx
1088	for reverse split /\s*,\s*/,	1275	for reverse split /\s*,\s*/,
1089	$ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";	1276	$ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";
1090	}	1277	}
1091		1278
		1279	our @post_detect;
		1280
		1281	sub post_detect(&) {
		1282	my ($cb) = @_;
		1283
		1284	push @post_detect, $cb;
		1285
		1286	defined wantarray
		1287	? bless \$cb, "AnyEvent::Util::postdetect"
		1288	: ()
		1289	}
		1290
		1291	sub AnyEvent::Util::postdetect::DESTROY {
		1292	@post_detect = grep $_ != ${$_[0]}, @post_detect;
		1293	}
		1294
		1295	our $POSTPONE_W;
		1296	our @POSTPONE;
		1297
		1298	sub _postpone_exec {
		1299	undef $POSTPONE_W;
		1300
		1301	&{ shift @POSTPONE }
		1302	while @POSTPONE;
		1303	}
		1304
		1305	sub postpone(&) {
		1306	push @POSTPONE, shift;
		1307
		1308	$POSTPONE_W ||= AE::timer (0, 0, \&_postpone_exec);
		1309
		1310	()
		1311	}
		1312
		1313	sub log($$;@) {
		1314	# only load the big bloated module when we actually are about to log something
		1315	if ($_[0] <= ($VERBOSE || 1)) { # also catches non-numeric levels(!) and fatal
		1316	local ($!, $@);
		1317	require AnyEvent::Log; # among other things, sets $VERBOSE to 9
		1318	# AnyEvent::Log overwrites this function
		1319	goto &log;
		1320	}
		1321
		1322	0 # not logged
		1323	}
		1324
		1325	sub _logger($;$) {
		1326	my ($level, $renabled) = @_;
		1327
		1328	$$renabled = $level <= $VERBOSE;
		1329
		1330	my $logger = [(caller)[0], $level, $renabled];
		1331
		1332	$AnyEvent::Log::LOGGER{$logger+0} = $logger;
		1333
		1334	# return unless defined wantarray;
		1335	#
		1336	# require AnyEvent::Util;
		1337	# my $guard = AnyEvent::Util::guard (sub {
		1338	# # "clean up"
		1339	# delete $LOGGER{$logger+0};
		1340	# });
		1341	#
		1342	# sub {
		1343	# return 0 unless $$renabled;
		1344	#
		1345	# $guard if 0; # keep guard alive, but don't cause runtime overhead
		1346	# require AnyEvent::Log unless $AnyEvent::Log::VERSION;
		1347	# package AnyEvent::Log;
		1348	# _log ($logger->[0], $level, @_) # logger->[0] has been converted at load time
		1349	# }
		1350	}
		1351
		1352	if (length $ENV{PERL_ANYEVENT_LOG}) {
		1353	require AnyEvent::Log; # AnyEvent::Log does the thing for us
		1354	}
		1355
1092	my @models = (	1356	our @models = (
1093	[EV:: => AnyEvent::Impl::EV::],	1357	[EV:: => AnyEvent::Impl::EV::],
1094	[Event:: => AnyEvent::Impl::Event::],
1095	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::],	1358	[AnyEvent::Loop:: => AnyEvent::Impl::Perl::],
1096	# everything below here will not be autoprobed	1359	# everything below here will not (normally) be autoprobed
1097	# as the pureperl backend should work everywhere	1360	# as the pure perl backend should work everywhere
1098	# and is usually faster	1361	# and is usually faster
		1362	[Irssi:: => AnyEvent::Impl::Irssi::], # Irssi has a bogus "Event" package, so msut be near the top
		1363	[Event:: => AnyEvent::Impl::Event::], # slow, stable
1099	[Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers	1364	[Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers
		1365	# everything below here should not be autoloaded
1100	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy	1366	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
1101	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles	1367	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
1102	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program	1368	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program
1103	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza	1369	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
1104	[Wx:: => AnyEvent::Impl::POE::],	1370	[Wx:: => AnyEvent::Impl::POE::],
1105	[Prima:: => AnyEvent::Impl::POE::],	1371	[Prima:: => AnyEvent::Impl::POE::],
1106	# IO::Async is just too broken - we would need workarounds for its	1372	[IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # a bitch to autodetect
1107	# byzantine signal and broken child handling, among others.	1373	[Cocoa::EventLoop:: => AnyEvent::Impl::Cocoa::],
1108	# IO::Async is rather hard to detect, as it doesn't have any	1374	[FLTK:: => AnyEvent::Impl::FLTK::],
1109	# obvious default class.
1110	# [IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program
1111	# [IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program
1112	# [IO::Async::Notifier:: => AnyEvent::Impl::IOAsync::], # requires special main program
1113	);	1375	);
1114		1376
1115	our %method = map +($_ => 1),	1377	our @isa_hook;
		1378
		1379	sub _isa_set {
		1380	my @pkg = ("AnyEvent", (map $_->[0], grep defined, @isa_hook), $MODEL);
		1381
		1382	@{"$pkg[$_-1]::ISA"} = $pkg[$_]
		1383	for 1 .. $#pkg;
		1384
		1385	grep $_ && $_->[1], @isa_hook
		1386	and AE::_reset ();
		1387	}
		1388
		1389	# used for hooking AnyEvent::Strict and AnyEvent::Debug::Wrap into the class hierarchy
		1390	sub _isa_hook($$;$) {
		1391	my ($i, $pkg, $reset_ae) = @_;
		1392
		1393	$isa_hook[$i] = $pkg ? [$pkg, $reset_ae] : undef;
		1394
		1395	_isa_set;
		1396	}
		1397
		1398	# all autoloaded methods reserve the complete glob, not just the method slot.
		1399	# due to bugs in perls method cache implementation.
1116	qw(io timer time now now_update signal child idle condvar one_event DESTROY);	1400	our @methods = qw(io timer time now now_update signal child idle condvar);
1117		1401
1118	our @post_detect;
1119
1120	sub post_detect(&) {	1402	sub detect() {
1121	my ($cb) = @_;	1403	return $MODEL if $MODEL; # some programs keep references to detect
1122		1404
1123	if ($MODEL) {	1405	# IO::Async::Loop::AnyEvent is extremely evil, refuse to work with it
1124	$cb->();	1406	# the author knows about the problems and what it does to AnyEvent as a whole
		1407	# (and the ability of others to use AnyEvent), but simply wants to abuse AnyEvent
		1408	# anyway.
		1409	AnyEvent::log fatal => "IO::Async::Loop::AnyEvent detected - that module is broken by\n"
		1410	. "design, abuses internals and breaks AnyEvent - will not continue."
		1411	if exists $INC{"IO/Async/Loop/AnyEvent.pm"};
1125		1412
1126	1	1413	local $!; # for good measure
		1414	local $SIG{__DIE__}; # we use eval
		1415
		1416	# free some memory
		1417	*detect = sub () { $MODEL };
		1418	# undef &func doesn't correctly update the method cache. grmbl.
		1419	# so we delete the whole glob. grmbl.
		1420	# otoh, perl doesn't let me undef an active usb, but it lets me free
		1421	# a glob with an active sub. hrm. i hope it works, but perl is
		1422	# usually buggy in this department. sigh.
		1423	delete @{"AnyEvent::"}{@methods};
		1424	undef @methods;
		1425
		1426	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z0-9:]+)$/) {
		1427	my $model = $1;
		1428	$model = "AnyEvent::Impl::$model" unless $model =~ s/::$//;
		1429	if (eval "require $model") {
		1430	AnyEvent::log 7 => "Loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.";
		1431	$MODEL = $model;
1127	} else {	1432	} else {
1128	push @post_detect, $cb;	1433	AnyEvent::log 4 => "Unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@";
1129		1434	}
1130	defined wantarray
1131	? bless \$cb, "AnyEvent::Util::postdetect"
1132	: ()
1133	}	1435	}
1134	}
1135		1436
1136	sub AnyEvent::Util::postdetect::DESTROY {	1437	# check for already loaded models
1137	@post_detect = grep $_ != ${$_[0]}, @post_detect;
1138	}
1139
1140	sub detect() {
1141	unless ($MODEL) {	1438	unless ($MODEL) {
1142	local $SIG{__DIE__};	1439	for (@REGISTRY, @models) {
1143		1440	my ($package, $model) = @$_;
1144	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {	1441	if (${"$package\::VERSION"} > 0) {
1145	my $model = "AnyEvent::Impl::$1";
1146	if (eval "require $model") {	1442	if (eval "require $model") {
		1443	AnyEvent::log 7 => "Autodetected model '$model', using it.";
1147	$MODEL = $model;	1444	$MODEL = $model;
1148	warn "AnyEvent: loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.\n" if $VERBOSE >= 2;	1445	last;
1149	} else {	1446	} else {
1150	warn "AnyEvent: unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@" if $VERBOSE;	1447	AnyEvent::log 8 => "Detected event loop $package, but cannot load '$model', skipping: $@";
		1448	}
1151	}	1449	}
1152	}	1450	}
1153		1451
1154	# check for already loaded models
1155	unless ($MODEL) {	1452	unless ($MODEL) {
		1453	# try to autoload a model
1156	for (@REGISTRY, @models) {	1454	for (@REGISTRY, @models) {
1157	my ($package, $model) = @$_;	1455	my ($package, $model) = @$_;
		1456	if (
		1457	eval "require $package"
1158	if (${"$package\::VERSION"} > 0) {	1458	and ${"$package\::VERSION"} > 0
1159	if (eval "require $model") {	1459	and eval "require $model"
		1460	) {
		1461	AnyEvent::log 7 => "Autoloaded model '$model', using it.";
1160	$MODEL = $model;	1462	$MODEL = $model;
1161	warn "AnyEvent: autodetected model '$model', using it.\n" if $VERBOSE >= 2;
1162	last;	1463	last;
1163	}
1164	}	1464	}
1165	}	1465	}
1166		1466
1167	unless ($MODEL) {
1168	# try to load a model
1169
1170	for (@REGISTRY, @models) {
1171	my ($package, $model) = @$_;
1172	if (eval "require $package"
1173	and ${"$package\::VERSION"} > 0
1174	and eval "require $model") {
1175	$MODEL = $model;
1176	warn "AnyEvent: autoprobed model '$model', using it.\n" if $VERBOSE >= 2;
1177	last;
1178	}
1179	}
1180
1181	$MODEL	1467	$MODEL
1182	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.\n";	1468	or AnyEvent::log fatal => "Backend autodetection failed - did you properly install AnyEvent?";
1183	}
1184	}	1469	}
1185
1186	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
1187
1188	unshift @ISA, $MODEL;
1189
1190	require AnyEvent::Strict if $ENV{PERL_ANYEVENT_STRICT};
1191
1192	(shift @post_detect)->() while @post_detect;
1193	}	1470	}
1194		1471
		1472	# free memory only needed for probing
		1473	undef @models;
		1474	undef @REGISTRY;
		1475
		1476	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
		1477
		1478	# now nuke some methods that are overridden by the backend.
		1479	# SUPER usage is not allowed in these.
		1480	for (qw(time signal child idle)) {
		1481	undef &{"AnyEvent::Base::$_"}
		1482	if defined &{"$MODEL\::$_"};
		1483	}
		1484
		1485	_isa_set;
		1486
		1487	# we're officially open!
		1488
		1489	if ($ENV{PERL_ANYEVENT_STRICT}) {
		1490	require AnyEvent::Strict;
		1491	}
		1492
		1493	if ($ENV{PERL_ANYEVENT_DEBUG_WRAP}) {
		1494	require AnyEvent::Debug;
		1495	AnyEvent::Debug::wrap ($ENV{PERL_ANYEVENT_DEBUG_WRAP});
		1496	}
		1497
		1498	if (length $ENV{PERL_ANYEVENT_DEBUG_SHELL}) {
		1499	require AnyEvent::Socket;
		1500	require AnyEvent::Debug;
		1501
		1502	my $shell = $ENV{PERL_ANYEVENT_DEBUG_SHELL};
		1503	$shell =~ s/\$\$/$$/g;
		1504
		1505	my ($host, $service) = AnyEvent::Socket::parse_hostport ($shell);
		1506	$AnyEvent::Debug::SHELL = AnyEvent::Debug::shell ($host, $service);
		1507	}
		1508
		1509	# now the anyevent environment is set up as the user told us to, so
		1510	# call the actual user code - post detects
		1511
		1512	(shift @post_detect)->() while @post_detect;
		1513	undef @post_detect;
		1514
		1515	*post_detect = sub(&) {
		1516	shift->();
		1517
		1518	undef
		1519	};
		1520
1195	$MODEL	1521	$MODEL
1196	}	1522	}
1197		1523
1198	sub AUTOLOAD {	1524	for my $name (@methods) {
1199	(my $func = $AUTOLOAD) =~ s/.*://;	1525	*$name = sub {
1200		1526	detect;
1201	$method{$func}	1527	# we use goto because
1202	or Carp::croak "$func: not a valid method for AnyEvent objects";	1528	# a) it makes the thunk more transparent
1203		1529	# b) it allows us to delete the thunk later
1204	detect unless $MODEL;	1530	goto &{ UNIVERSAL::can AnyEvent => "SUPER::$name" }
1205		1531	};
1206	my $class = shift;
1207	$class->$func (@_);
1208	}	1532	}
1209		1533
1210	# utility function to dup a filehandle. this is used by many backends	1534	# utility function to dup a filehandle. this is used by many backends
1211	# to support binding more than one watcher per filehandle (they usually	1535	# to support binding more than one watcher per filehandle (they usually
1212	# allow only one watcher per fd, so we dup it to get a different one).	1536	# allow only one watcher per fd, so we dup it to get a different one).
…		…
1222	# we assume CLOEXEC is already set by perl in all important cases	1546	# we assume CLOEXEC is already set by perl in all important cases
1223		1547
1224	($fh2, $rw)	1548	($fh2, $rw)
1225	}	1549	}
1226		1550
		1551	=head1 SIMPLIFIED AE API
		1552
		1553	Starting with version 5.0, AnyEvent officially supports a second, much
		1554	simpler, API that is designed to reduce the calling, typing and memory
		1555	overhead by using function call syntax and a fixed number of parameters.
		1556
		1557	See the L<AE> manpage for details.
		1558
		1559	=cut
		1560
		1561	package AE;
		1562
		1563	our $VERSION = $AnyEvent::VERSION;
		1564
		1565	sub _reset() {
		1566	eval q{
		1567	# fall back to the main API by default - backends and AnyEvent::Base
		1568	# implementations can overwrite these.
		1569
		1570	sub io($$$) {
		1571	AnyEvent->io (fh => $_[0], poll => $_[1] ? "w" : "r", cb => $_[2])
		1572	}
		1573
		1574	sub timer($$$) {
		1575	AnyEvent->timer (after => $_[0], interval => $_[1], cb => $_[2])
		1576	}
		1577
		1578	sub signal($$) {
		1579	AnyEvent->signal (signal => $_[0], cb => $_[1])
		1580	}
		1581
		1582	sub child($$) {
		1583	AnyEvent->child (pid => $_[0], cb => $_[1])
		1584	}
		1585
		1586	sub idle($) {
		1587	AnyEvent->idle (cb => $_[0]);
		1588	}
		1589
		1590	sub cv(;&) {
		1591	AnyEvent->condvar (@_ ? (cb => $_[0]) : ())
		1592	}
		1593
		1594	sub now() {
		1595	AnyEvent->now
		1596	}
		1597
		1598	sub now_update() {
		1599	AnyEvent->now_update
		1600	}
		1601
		1602	sub time() {
		1603	AnyEvent->time
		1604	}
		1605
		1606	*postpone = \&AnyEvent::postpone;
		1607	*log = \&AnyEvent::log;
		1608	};
		1609	die if $@;
		1610	}
		1611
		1612	BEGIN { _reset }
		1613
1227	package AnyEvent::Base;	1614	package AnyEvent::Base;
1228		1615
1229	# default implementations for many methods	1616	# default implementations for many methods
1230		1617
1231	sub _time {	1618	sub time {
		1619	eval q{ # poor man's autoloading {}
1232	# probe for availability of Time::HiRes	1620	# probe for availability of Time::HiRes
1233	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {	1621	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {
1234	warn "AnyEvent: using Time::HiRes for sub-second timing accuracy.\n" if $VERBOSE >= 8;	1622	*time = sub { Time::HiRes::time () };
1235	*_time = \&Time::HiRes::time;	1623	*AE::time = \& Time::HiRes::time ;
		1624	*now = \&time;
		1625	AnyEvent::log 8 => "using Time::HiRes for sub-second timing accuracy.";
1236	# if (eval "use POSIX (); (POSIX::times())...	1626	# if (eval "use POSIX (); (POSIX::times())...
1237	} else {	1627	} else {
1238	warn "AnyEvent: using built-in time(), WARNING, no sub-second resolution!\n" if $VERBOSE;	1628	*time = sub { CORE::time };
1239	*_time = sub { time }; # epic fail	1629	*AE::time = sub (){ CORE::time };
		1630	*now = \&time;
		1631	AnyEvent::log 3 => "Using built-in time(), no sub-second resolution!";
		1632	}
1240	}	1633	};
		1634	die if $@;
1241		1635
1242	&_time	1636	&time
1243	}	1637	}
1244		1638
1245	sub time { _time }	1639	*now = \&time;
1246	sub now { _time }
1247	sub now_update { }	1640	sub now_update { }
1248		1641
		1642	sub _poll {
		1643	Carp::croak "$AnyEvent::MODEL does not support blocking waits. Caught";
		1644	}
		1645
1249	# default implementation for ->condvar	1646	# default implementation for ->condvar
		1647	# in fact, the default should not be overwritten
1250		1648
1251	sub condvar {	1649	sub condvar {
		1650	eval q{ # poor man's autoloading {}
		1651	*condvar = sub {
1252	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"	1652	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"
		1653	};
		1654
		1655	*AE::cv = sub (;&) {
		1656	bless { @_ ? (_ae_cb => shift) : () }, "AnyEvent::CondVar"
		1657	};
		1658	};
		1659	die if $@;
		1660
		1661	&condvar
1253	}	1662	}
1254		1663
1255	# default implementation for ->signal	1664	# default implementation for ->signal
1256		1665
1257	our $HAVE_ASYNC_INTERRUPT;	1666	our $HAVE_ASYNC_INTERRUPT;
		1667
		1668	sub _have_async_interrupt() {
		1669	$HAVE_ASYNC_INTERRUPT = 1*(!$ENV{PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT}
		1670	&& eval "use Async::Interrupt 1.02 (); 1")
		1671	unless defined $HAVE_ASYNC_INTERRUPT;
		1672
		1673	$HAVE_ASYNC_INTERRUPT
		1674	}
		1675
1258	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);	1676	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);
1259	our (%SIG_ASY, %SIG_ASY_W);	1677	our (%SIG_ASY, %SIG_ASY_W);
1260	our ($SIG_COUNT, $SIG_TW);	1678	our ($SIG_COUNT, $SIG_TW);
1261		1679
1262	sub _signal_exec {	1680	# install a dummy wakeup watcher to reduce signal catching latency
1263	$HAVE_ASYNC_INTERRUPT	1681	# used by Impls
1264	? $SIGPIPE_R->drain	1682	sub _sig_add() {
1265	: sysread $SIGPIPE_R, my $dummy, 9;	1683	unless ($SIG_COUNT++) {
		1684	# try to align timer on a full-second boundary, if possible
		1685	my $NOW = AE::now;
1266		1686
1267	while (%SIG_EV) {	1687	$SIG_TW = AE::timer
1268	for (keys %SIG_EV) {	1688	$MAX_SIGNAL_LATENCY - ($NOW - int $NOW),
1269	delete $SIG_EV{$_};	1689	$MAX_SIGNAL_LATENCY,
1270	$_->() for values %{ $SIG_CB{$_} || {} };	1690	sub { } # just for the PERL_ASYNC_CHECK
1271	}	1691	;
1272	}	1692	}
1273	}	1693	}
1274		1694
1275	sub _signal {	1695	sub _sig_del {
1276	my (undef, %arg) = @_;
1277
1278	my $signal = uc $arg{signal}
1279	or Carp::croak "required option 'signal' is missing";
1280
1281	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
1282
1283	if ($HAVE_ASYNC_INTERRUPT) {
1284	# async::interrupt
1285
1286	$SIG_ASY{$signal} ||= do {
1287	my $asy = new Async::Interrupt
1288	cb => sub { undef $SIG_EV{$signal} },
1289	signal => $signal,
1290	pipe => [$SIGPIPE_R->filenos],
1291	;
1292	$asy->pipe_autodrain (0);
1293
1294	$asy
1295	};
1296
1297	} else {
1298	# pure perl
1299
1300	$SIG{$signal} ||= sub {
1301	local $!;
1302	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;
1303	undef $SIG_EV{$signal};
1304	};
1305
1306	# can't do signal processing without introducing races in pure perl,
1307	# so limit the signal latency.
1308	++$SIG_COUNT;
1309	$SIG_TW ||= AnyEvent->timer (
1310	after => $MAX_SIGNAL_LATENCY,
1311	interval => $MAX_SIGNAL_LATENCY,
1312	cb => sub { }, # just for the PERL_ASYNC_CHECK
1313	);
1314	}
1315
1316	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
1317	}
1318
1319	sub signal {
1320	# probe for availability of Async::Interrupt
1321	if (!$ENV{PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT} && eval "use Async::Interrupt 0.6 (); 1") {
1322	warn "AnyEvent: using Async::Interrupt for race-free signal handling.\n" if $VERBOSE >= 8;
1323
1324	$HAVE_ASYNC_INTERRUPT = 1;
1325	$SIGPIPE_R = new Async::Interrupt::EventPipe;
1326	$SIG_IO = AnyEvent->io (fh => $SIGPIPE_R->fileno, poll => "r", cb => \&_signal_exec);
1327
1328	} else {
1329	warn "AnyEvent: using emulated perl signal handling with latency timer.\n" if $VERBOSE >= 8;
1330
1331	require Fcntl;
1332
1333	if (AnyEvent::WIN32) {
1334	require AnyEvent::Util;
1335
1336	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
1337	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R) if $SIGPIPE_R;
1338	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W) if $SIGPIPE_W; # just in case
1339	} else {
1340	pipe $SIGPIPE_R, $SIGPIPE_W;
1341	fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R;
1342	fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case
1343
1344	# not strictly required, as $^F is normally 2, but let's make sure...
1345	fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
1346	fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
1347	}
1348
1349	$SIGPIPE_R
1350	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";
1351
1352	$SIG_IO = AnyEvent->io (fh => $SIGPIPE_R, poll => "r", cb => \&_signal_exec);
1353	}
1354
1355	*signal = \&_signal;
1356	&signal
1357	}
1358
1359	sub AnyEvent::Base::signal::DESTROY {
1360	my ($signal, $cb) = @{$_[0]};
1361
1362	undef $SIG_TW	1696	undef $SIG_TW
1363	unless --$SIG_COUNT;	1697	unless --$SIG_COUNT;
		1698	}
1364		1699
		1700	our $_sig_name_init; $_sig_name_init = sub {
		1701	eval q{ # poor man's autoloading {}
		1702	undef $_sig_name_init;
		1703
		1704	if (_have_async_interrupt) {
		1705	*sig2num = \&Async::Interrupt::sig2num;
		1706	*sig2name = \&Async::Interrupt::sig2name;
		1707	} else {
		1708	require Config;
		1709
		1710	my %signame2num;
		1711	@signame2num{ split ' ', $Config::Config{sig_name} }
		1712	= split ' ', $Config::Config{sig_num};
		1713
		1714	my @signum2name;
		1715	@signum2name[values %signame2num] = keys %signame2num;
		1716
		1717	*sig2num = sub($) {
		1718	$_[0] > 0 ? shift : $signame2num{+shift}
		1719	};
		1720	*sig2name = sub ($) {
		1721	$_[0] > 0 ? $signum2name[+shift] : shift
		1722	};
		1723	}
		1724	};
		1725	die if $@;
		1726	};
		1727
		1728	sub sig2num ($) { &$_sig_name_init; &sig2num }
		1729	sub sig2name($) { &$_sig_name_init; &sig2name }
		1730
		1731	sub signal {
		1732	eval q{ # poor man's autoloading {}
		1733	# probe for availability of Async::Interrupt
		1734	if (_have_async_interrupt) {
		1735	AnyEvent::log 8 => "Using Async::Interrupt for race-free signal handling.";
		1736
		1737	$SIGPIPE_R = new Async::Interrupt::EventPipe;
		1738	$SIG_IO = AE::io $SIGPIPE_R->fileno, 0, \&_signal_exec;
		1739
		1740	} else {
		1741	AnyEvent::log 8 => "Using emulated perl signal handling with latency timer.";
		1742
		1743	if (AnyEvent::WIN32) {
		1744	require AnyEvent::Util;
		1745
		1746	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
		1747	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R, 1) if $SIGPIPE_R;
		1748	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W, 1) if $SIGPIPE_W; # just in case
		1749	} else {
		1750	pipe $SIGPIPE_R, $SIGPIPE_W;
		1751	fcntl $SIGPIPE_R, AnyEvent::F_SETFL, AnyEvent::O_NONBLOCK if $SIGPIPE_R;
		1752	fcntl $SIGPIPE_W, AnyEvent::F_SETFL, AnyEvent::O_NONBLOCK if $SIGPIPE_W; # just in case
		1753
		1754	# not strictly required, as $^F is normally 2, but let's make sure...
		1755	fcntl $SIGPIPE_R, AnyEvent::F_SETFD, AnyEvent::FD_CLOEXEC;
		1756	fcntl $SIGPIPE_W, AnyEvent::F_SETFD, AnyEvent::FD_CLOEXEC;
		1757	}
		1758
		1759	$SIGPIPE_R
		1760	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";
		1761
		1762	$SIG_IO = AE::io $SIGPIPE_R, 0, \&_signal_exec;
		1763	}
		1764
		1765	*signal = $HAVE_ASYNC_INTERRUPT
		1766	? sub {
		1767	my (undef, %arg) = @_;
		1768
		1769	# async::interrupt
		1770	my $signal = sig2num $arg{signal};
		1771	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
		1772
		1773	$SIG_ASY{$signal} ||= new Async::Interrupt
		1774	cb => sub { undef $SIG_EV{$signal} },
		1775	signal => $signal,
		1776	pipe => [$SIGPIPE_R->filenos],
		1777	pipe_autodrain => 0,
		1778	;
		1779
		1780	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
		1781	}
		1782	: sub {
		1783	my (undef, %arg) = @_;
		1784
		1785	# pure perl
		1786	my $signal = sig2name $arg{signal};
		1787	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
		1788
		1789	$SIG{$signal} ||= sub {
		1790	local $!;
		1791	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;
		1792	undef $SIG_EV{$signal};
		1793	};
		1794
		1795	# can't do signal processing without introducing races in pure perl,
		1796	# so limit the signal latency.
		1797	_sig_add;
		1798
		1799	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
		1800	}
		1801	;
		1802
		1803	*AnyEvent::Base::signal::DESTROY = sub {
		1804	my ($signal, $cb) = @{$_[0]};
		1805
		1806	_sig_del;
		1807
1365	delete $SIG_CB{$signal}{$cb};	1808	delete $SIG_CB{$signal}{$cb};
1366		1809
1367	$HAVE_ASYNC_INTERRUPT	1810	$HAVE_ASYNC_INTERRUPT
1368	? delete $SIG_ASY{$signal}	1811	? delete $SIG_ASY{$signal}
1369	: # delete doesn't work with older perls - they then	1812	: # delete doesn't work with older perls - they then
1370	# print weird messages, or just unconditionally exit	1813	# print weird messages, or just unconditionally exit
1371	# instead of getting the default action.	1814	# instead of getting the default action.
1372	undef $SIG{$signal}	1815	undef $SIG{$signal}
1373	unless keys %{ $SIG_CB{$signal} };	1816	unless keys %{ $SIG_CB{$signal} };
		1817	};
		1818
		1819	*_signal_exec = sub {
		1820	$HAVE_ASYNC_INTERRUPT
		1821	? $SIGPIPE_R->drain
		1822	: sysread $SIGPIPE_R, (my $dummy), 9;
		1823
		1824	while (%SIG_EV) {
		1825	for (keys %SIG_EV) {
		1826	delete $SIG_EV{$_};
		1827	&$_ for values %{ $SIG_CB{$_} || {} };
		1828	}
		1829	}
		1830	};
		1831	};
		1832	die if $@;
		1833
		1834	&signal
1374	}	1835	}
1375		1836
1376	# default implementation for ->child	1837	# default implementation for ->child
1377		1838
1378	our %PID_CB;	1839	our %PID_CB;
1379	our $CHLD_W;	1840	our $CHLD_W;
1380	our $CHLD_DELAY_W;	1841	our $CHLD_DELAY_W;
1381	our $WNOHANG;
1382		1842
1383	sub _sigchld {	1843	# used by many Impl's
1384	while (0 < (my $pid = waitpid -1, $WNOHANG)) {	1844	sub _emit_childstatus($$) {
1385	$_->($pid, $?)	1845	my (undef, $rpid, $rstatus) = @_;
		1846
		1847	$_->($rpid, $rstatus)
1386	for values %{ $PID_CB{$pid} || {} },	1848	for values %{ $PID_CB{$rpid} || {} },
1387	values %{ $PID_CB{0} || {} };	1849	values %{ $PID_CB{0} || {} };
1388	}
1389	}	1850	}
1390		1851
1391	sub child {	1852	sub child {
		1853	eval q{ # poor man's autoloading {}
		1854	*_sigchld = sub {
		1855	my $pid;
		1856
		1857	AnyEvent->_emit_childstatus ($pid, $?)
		1858	while ($pid = waitpid -1, WNOHANG) > 0;
		1859	};
		1860
		1861	*child = sub {
1392	my (undef, %arg) = @_;	1862	my (undef, %arg) = @_;
1393		1863
1394	defined (my $pid = $arg{pid} + 0)	1864	my $pid = $arg{pid};
1395	or Carp::croak "required option 'pid' is missing";	1865	my $cb = $arg{cb};
1396		1866
1397	$PID_CB{$pid}{$arg{cb}} = $arg{cb};	1867	$PID_CB{$pid}{$cb+0} = $cb;
1398		1868
1399	# WNOHANG is almost cetrainly 1 everywhere
1400	$WNOHANG ||= $^O =~ /^(?:openbsd|netbsd|linux|freebsd|cygwin|MSWin32)$/
1401	? 1
1402	: eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1;
1403
1404	unless ($CHLD_W) {	1869	unless ($CHLD_W) {
1405	$CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld);	1870	$CHLD_W = AE::signal CHLD => \&_sigchld;
1406	# child could be a zombie already, so make at least one round	1871	# child could be a zombie already, so make at least one round
1407	&_sigchld;	1872	&_sigchld;
1408	}	1873	}
1409		1874
1410	bless [$pid, $arg{cb}], "AnyEvent::Base::child"	1875	bless [$pid, $cb+0], "AnyEvent::Base::child"
1411	}	1876	};
1412		1877
1413	sub AnyEvent::Base::child::DESTROY {	1878	*AnyEvent::Base::child::DESTROY = sub {
1414	my ($pid, $cb) = @{$_[0]};	1879	my ($pid, $icb) = @{$_[0]};
1415		1880
1416	delete $PID_CB{$pid}{$cb};	1881	delete $PID_CB{$pid}{$icb};
1417	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };	1882	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };
1418		1883
1419	undef $CHLD_W unless keys %PID_CB;	1884	undef $CHLD_W unless keys %PID_CB;
		1885	};
		1886	};
		1887	die if $@;
		1888
		1889	&child
1420	}	1890	}
1421		1891
1422	# idle emulation is done by simply using a timer, regardless	1892	# idle emulation is done by simply using a timer, regardless
1423	# of whether the process is idle or not, and not letting	1893	# of whether the process is idle or not, and not letting
1424	# the callback use more than 50% of the time.	1894	# the callback use more than 50% of the time.
1425	sub idle {	1895	sub idle {
		1896	eval q{ # poor man's autoloading {}
		1897	*idle = sub {
1426	my (undef, %arg) = @_;	1898	my (undef, %arg) = @_;
1427		1899
1428	my ($cb, $w, $rcb) = $arg{cb};	1900	my ($cb, $w, $rcb) = $arg{cb};
1429		1901
1430	$rcb = sub {	1902	$rcb = sub {
1431	if ($cb) {	1903	if ($cb) {
1432	$w = _time;	1904	$w = AE::time;
1433	&$cb;	1905	&$cb;
1434	$w = _time - $w;	1906	$w = AE::time - $w;
1435		1907
1436	# never use more then 50% of the time for the idle watcher,	1908	# never use more then 50% of the time for the idle watcher,
1437	# within some limits	1909	# within some limits
1438	$w = 0.0001 if $w < 0.0001;	1910	$w = 0.0001 if $w < 0.0001;
1439	$w = 5 if $w > 5;	1911	$w = 5 if $w > 5;
1440		1912
1441	$w = AnyEvent->timer (after => $w, cb => $rcb);	1913	$w = AE::timer $w, 0, $rcb;
1442	} else {	1914	} else {
1443	# clean up...	1915	# clean up...
1444	undef $w;	1916	undef $w;
1445	undef $rcb;	1917	undef $rcb;
		1918	}
		1919	};
		1920
		1921	$w = AE::timer 0.05, 0, $rcb;
		1922
		1923	bless \\$cb, "AnyEvent::Base::idle"
1446	}	1924	};
		1925
		1926	*AnyEvent::Base::idle::DESTROY = sub {
		1927	undef $${$_[0]};
		1928	};
1447	};	1929	};
		1930	die if $@;
1448		1931
1449	$w = AnyEvent->timer (after => 0.05, cb => $rcb);	1932	&idle
1450
1451	bless \\$cb, "AnyEvent::Base::idle"
1452	}
1453
1454	sub AnyEvent::Base::idle::DESTROY {
1455	undef $${$_[0]};
1456	}	1933	}
1457		1934
1458	package AnyEvent::CondVar;	1935	package AnyEvent::CondVar;
1459		1936
1460	our @ISA = AnyEvent::CondVar::Base::;	1937	our @ISA = AnyEvent::CondVar::Base::;
		1938
		1939	# only to be used for subclassing
		1940	sub new {
		1941	my $class = shift;
		1942	bless AnyEvent->condvar (@_), $class
		1943	}
1461		1944
1462	package AnyEvent::CondVar::Base;	1945	package AnyEvent::CondVar::Base;
1463		1946
1464	#use overload	1947	#use overload
1465	# '&{}' => sub { my $self = shift; sub { $self->send (@_) } },	1948	# '&{}' => sub { my $self = shift; sub { $self->send (@_) } },
…		…
1475		1958
1476	sub _send {	1959	sub _send {
1477	# nop	1960	# nop
1478	}	1961	}
1479		1962
		1963	sub _wait {
		1964	AnyEvent->_poll until $_[0]{_ae_sent};
		1965	}
		1966
1480	sub send {	1967	sub send {
1481	my $cv = shift;	1968	my $cv = shift;
1482	$cv->{_ae_sent} = [@_];	1969	$cv->{_ae_sent} = [@_];
1483	(delete $cv->{_ae_cb})->($cv) if $cv->{_ae_cb};	1970	(delete $cv->{_ae_cb})->($cv) if $cv->{_ae_cb};
1484	$cv->_send;	1971	$cv->_send;
…		…
1491		1978
1492	sub ready {	1979	sub ready {
1493	$_[0]{_ae_sent}	1980	$_[0]{_ae_sent}
1494	}	1981	}
1495		1982
1496	sub _wait {
1497	$WAITING
1498	and !$_[0]{_ae_sent}
1499	and Carp::croak "AnyEvent::CondVar: recursive blocking wait detected";
1500
1501	local $WAITING = 1;
1502	AnyEvent->one_event while !$_[0]{_ae_sent};
1503	}
1504
1505	sub recv {	1983	sub recv {
		1984	unless ($_[0]{_ae_sent}) {
		1985	$WAITING
		1986	and Carp::croak "AnyEvent::CondVar: recursive blocking wait attempted";
		1987
		1988	local $WAITING = 1;
1506	$_[0]->_wait;	1989	$_[0]->_wait;
		1990	}
1507		1991
1508	Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak};	1992	$_[0]{_ae_croak}
1509	wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0]	1993	and Carp::croak $_[0]{_ae_croak};
		1994
		1995	wantarray
		1996	? @{ $_[0]{_ae_sent} }
		1997	: $_[0]{_ae_sent}[0]
1510	}	1998	}
1511		1999
1512	sub cb {	2000	sub cb {
1513	$_[0]{_ae_cb} = $_[1] if @_ > 1;	2001	my $cv = shift;
		2002
		2003	@_
		2004	and $cv->{_ae_cb} = shift
		2005	and $cv->{_ae_sent}
		2006	and (delete $cv->{_ae_cb})->($cv);
		2007
1514	$_[0]{_ae_cb}	2008	$cv->{_ae_cb}
1515	}	2009	}
1516		2010
1517	sub begin {	2011	sub begin {
1518	++$_[0]{_ae_counter};	2012	++$_[0]{_ae_counter};
1519	$_[0]{_ae_end_cb} = $_[1] if @_ > 1;	2013	$_[0]{_ae_end_cb} = $_[1] if @_ > 1;
…		…
1524	&{ $_[0]{_ae_end_cb} || sub { $_[0]->send } };	2018	&{ $_[0]{_ae_end_cb} || sub { $_[0]->send } };
1525	}	2019	}
1526		2020
1527	# undocumented/compatibility with pre-3.4	2021	# undocumented/compatibility with pre-3.4
1528	*broadcast = \&send;	2022	*broadcast = \&send;
1529	*wait = \&_wait;	2023	*wait = \&recv;
1530		2024
1531	=head1 ERROR AND EXCEPTION HANDLING	2025	=head1 ERROR AND EXCEPTION HANDLING
1532		2026
1533	In general, AnyEvent does not do any error handling - it relies on the	2027	In general, AnyEvent does not do any error handling - it relies on the
1534	caller to do that if required. The L<AnyEvent::Strict> module (see also	2028	caller to do that if required. The L<AnyEvent::Strict> module (see also
…		…
1546	$Event/EV::DIED->() >>, L<Glib> uses C<< install_exception_handler >> and	2040	$Event/EV::DIED->() >>, L<Glib> uses C<< install_exception_handler >> and
1547	so on.	2041	so on.
1548		2042
1549	=head1 ENVIRONMENT VARIABLES	2043	=head1 ENVIRONMENT VARIABLES
1550		2044
1551	The following environment variables are used by this module or its	2045	AnyEvent supports a number of environment variables that tune the
1552	submodules.	2046	runtime behaviour. They are usually evaluated when AnyEvent is
		2047	loaded, initialised, or a submodule that uses them is loaded. Many of
		2048	them also cause AnyEvent to load additional modules - for example,
		2049	C<PERL_ANYEVENT_DEBUG_WRAP> causes the L<AnyEvent::Debug> module to be
		2050	loaded.
1553		2051
1554	Note that AnyEvent will remove I<all> environment variables starting with	2052	All the environment variables documented here start with
1555	C<PERL_ANYEVENT_> from C<%ENV> when it is loaded while taint mode is	2053	C<PERL_ANYEVENT_>, which is what AnyEvent considers its own
1556	enabled.	2054	namespace. Other modules are encouraged (but by no means required) to use
		2055	C<PERL_ANYEVENT_SUBMODULE> if they have registered the AnyEvent::Submodule
		2056	namespace on CPAN, for any submodule. For example, L<AnyEvent::HTTP> could
		2057	be expected to use C<PERL_ANYEVENT_HTTP_PROXY> (it should not access env
		2058	variables starting with C<AE_>, see below).
		2059
		2060	All variables can also be set via the C<AE_> prefix, that is, instead
		2061	of setting C<PERL_ANYEVENT_VERBOSE> you can also set C<AE_VERBOSE>. In
		2062	case there is a clash btween anyevent and another program that uses
		2063	C<AE_something> you can set the corresponding C<PERL_ANYEVENT_something>
		2064	variable to the empty string, as those variables take precedence.
		2065
		2066	When AnyEvent is first loaded, it copies all C<AE_xxx> env variables
		2067	to their C<PERL_ANYEVENT_xxx> counterpart unless that variable already
		2068	exists. If taint mode is on, then AnyEvent will remove I<all> environment
		2069	variables starting with C<PERL_ANYEVENT_> from C<%ENV> (or replace them
		2070	with C<undef> or the empty string, if the corresaponding C<AE_> variable
		2071	is set).
		2072
		2073	The exact algorithm is currently:
		2074
		2075	1. if taint mode enabled, delete all PERL_ANYEVENT_xyz variables from %ENV
		2076	2. copy over AE_xyz to PERL_ANYEVENT_xyz unless the latter alraedy exists
		2077	3. if taint mode enabled, set all PERL_ANYEVENT_xyz variables to undef.
		2078
		2079	This ensures that child processes will not see the C<AE_> variables.
		2080
		2081	The following environment variables are currently known to AnyEvent:
1557		2082
1558	=over 4	2083	=over 4
1559		2084
1560	=item C<PERL_ANYEVENT_VERBOSE>	2085	=item C<PERL_ANYEVENT_VERBOSE>
1561		2086
1562	By default, AnyEvent will be completely silent except in fatal	2087	By default, AnyEvent will log messages with loglevel C<4> (C<error>) or
1563	conditions. You can set this environment variable to make AnyEvent more	2088	higher (see L<AnyEvent::Log>). You can set this environment variable to a
1564	talkative.	2089	numerical loglevel to make AnyEvent more (or less) talkative.
1565		2090
		2091	If you want to do more than just set the global logging level
		2092	you should have a look at C<PERL_ANYEVENT_LOG>, which allows much more
		2093	complex specifications.
		2094
		2095	When set to C<0> (C<off>), then no messages whatsoever will be logged with
		2096	everything else at defaults.
		2097
1566	When set to C<1> or higher, causes AnyEvent to warn about unexpected	2098	When set to C<5> or higher (C<warn>), AnyEvent warns about unexpected
1567	conditions, such as not being able to load the event model specified by	2099	conditions, such as not being able to load the event model specified by
1568	C<PERL_ANYEVENT_MODEL>.	2100	C<PERL_ANYEVENT_MODEL>, or a guard callback throwing an exception - this
		2101	is the minimum recommended level for use during development.
1569		2102
1570	When set to C<2> or higher, cause AnyEvent to report to STDERR which event	2103	When set to C<7> or higher (info), AnyEvent reports which event model it
1571	model it chooses.	2104	chooses.
1572		2105
1573	When set to C<8> or higher, then AnyEvent will report extra information on	2106	When set to C<8> or higher (debug), then AnyEvent will report extra
1574	which optional modules it loads and how it implements certain features.	2107	information on which optional modules it loads and how it implements
		2108	certain features.
		2109
		2110	=item C<PERL_ANYEVENT_LOG>
		2111
		2112	Accepts rather complex logging specifications. For example, you could log
		2113	all C<debug> messages of some module to stderr, warnings and above to
		2114	stderr, and errors and above to syslog, with:
		2115
		2116	PERL_ANYEVENT_LOG=Some::Module=debug,+log:filter=warn,+%syslog:%syslog=error,syslog
		2117
		2118	For the rather extensive details, see L<AnyEvent::Log>.
		2119
		2120	This variable is evaluated when AnyEvent (or L<AnyEvent::Log>) is loaded,
		2121	so will take effect even before AnyEvent has initialised itself.
		2122
		2123	Note that specifying this environment variable causes the L<AnyEvent::Log>
		2124	module to be loaded, while C<PERL_ANYEVENT_VERBOSE> does not, so only
		2125	using the latter saves a few hundred kB of memory unless a module
		2126	explicitly needs the extra features of AnyEvent::Log.
1575		2127
1576	=item C<PERL_ANYEVENT_STRICT>	2128	=item C<PERL_ANYEVENT_STRICT>
1577		2129
1578	AnyEvent does not do much argument checking by default, as thorough	2130	AnyEvent does not do much argument checking by default, as thorough
1579	argument checking is very costly. Setting this variable to a true value	2131	argument checking is very costly. Setting this variable to a true value
…		…
1581	check the arguments passed to most method calls. If it finds any problems,	2133	check the arguments passed to most method calls. If it finds any problems,
1582	it will croak.	2134	it will croak.
1583		2135
1584	In other words, enables "strict" mode.	2136	In other words, enables "strict" mode.
1585		2137
1586	Unlike C<use strict> (or it's modern cousin, C<< use L<common::sense>	2138	Unlike C<use strict> (or its modern cousin, C<< use L<common::sense>
1587	>>, it is definitely recommended to keep it off in production. Keeping	2139	>>, it is definitely recommended to keep it off in production. Keeping
1588	C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs	2140	C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs
1589	can be very useful, however.	2141	can be very useful, however.
1590		2142
		2143	=item C<PERL_ANYEVENT_DEBUG_SHELL>
		2144
		2145	If this env variable is nonempty, then its contents will be interpreted by
		2146	C<AnyEvent::Socket::parse_hostport> and C<AnyEvent::Debug::shell> (after
		2147	replacing every occurance of C<$$> by the process pid). The shell object
		2148	is saved in C<$AnyEvent::Debug::SHELL>.
		2149
		2150	This happens when the first watcher is created.
		2151
		2152	For example, to bind a debug shell on a unix domain socket in
		2153	F<< /tmp/debug<pid>.sock >>, you could use this:
		2154
		2155	PERL_ANYEVENT_DEBUG_SHELL=/tmp/debug\$\$.sock perlprog
		2156	# connect with e.g.: socat readline /tmp/debug123.sock
		2157
		2158	Or to bind to tcp port 4545 on localhost:
		2159
		2160	PERL_ANYEVENT_DEBUG_SHELL=127.0.0.1:4545 perlprog
		2161	# connect with e.g.: telnet localhost 4545
		2162
		2163	Note that creating sockets in F</tmp> or on localhost is very unsafe on
		2164	multiuser systems.
		2165
		2166	=item C<PERL_ANYEVENT_DEBUG_WRAP>
		2167
		2168	Can be set to C<0>, C<1> or C<2> and enables wrapping of all watchers for
		2169	debugging purposes. See C<AnyEvent::Debug::wrap> for details.
		2170
1591	=item C<PERL_ANYEVENT_MODEL>	2171	=item C<PERL_ANYEVENT_MODEL>
1592		2172
1593	This can be used to specify the event model to be used by AnyEvent, before	2173	This can be used to specify the event model to be used by AnyEvent, before
1594	auto detection and -probing kicks in. It must be a string consisting	2174	auto detection and -probing kicks in.
1595	entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended	2175
		2176	It normally is a string consisting entirely of ASCII letters (e.g. C<EV>
		2177	or C<IOAsync>). The string C<AnyEvent::Impl::> gets prepended and the
1596	and the resulting module name is loaded and if the load was successful,	2178	resulting module name is loaded and - if the load was successful - used as
1597	used as event model. If it fails to load AnyEvent will proceed with	2179	event model backend. If it fails to load then AnyEvent will proceed with
1598	auto detection and -probing.	2180	auto detection and -probing.
1599		2181
1600	This functionality might change in future versions.	2182	If the string ends with C<::> instead (e.g. C<AnyEvent::Impl::EV::>) then
		2183	nothing gets prepended and the module name is used as-is (hint: C<::> at
		2184	the end of a string designates a module name and quotes it appropriately).
1601		2185
1602	For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you	2186	For example, to force the pure perl model (L<AnyEvent::Loop::Perl>) you
1603	could start your program like this:	2187	could start your program like this:
1604		2188
1605	PERL_ANYEVENT_MODEL=Perl perl ...	2189	PERL_ANYEVENT_MODEL=Perl perl ...
		2190
		2191	=item C<PERL_ANYEVENT_IO_MODEL>
		2192
		2193	The current file I/O model - see L<AnyEvent::IO> for more info.
		2194
		2195	At the moment, only C<Perl> (small, pure-perl, synchronous) and
		2196	C<IOAIO> (truly asynchronous) are supported. The default is C<IOAIO> if
		2197	L<AnyEvent::AIO> can be loaded, otherwise it is C<Perl>.
1606		2198
1607	=item C<PERL_ANYEVENT_PROTOCOLS>	2199	=item C<PERL_ANYEVENT_PROTOCOLS>
1608		2200
1609	Used by both L<AnyEvent::DNS> and L<AnyEvent::Socket> to determine preferences	2201	Used by both L<AnyEvent::DNS> and L<AnyEvent::Socket> to determine preferences
1610	for IPv4 or IPv6. The default is unspecified (and might change, or be the result	2202	for IPv4 or IPv6. The default is unspecified (and might change, or be the result
…		…
1623	but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4>	2215	but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4>
1624	- only support IPv4, never try to resolve or contact IPv6	2216	- only support IPv4, never try to resolve or contact IPv6
1625	addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or	2217	addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or
1626	IPv6, but prefer IPv6 over IPv4.	2218	IPv6, but prefer IPv6 over IPv4.
1627		2219
		2220	=item C<PERL_ANYEVENT_HOSTS>
		2221
		2222	This variable, if specified, overrides the F</etc/hosts> file used by
		2223	L<AnyEvent::Socket>C<::resolve_sockaddr>, i.e. hosts aliases will be read
		2224	from that file instead.
		2225
1628	=item C<PERL_ANYEVENT_EDNS0>	2226	=item C<PERL_ANYEVENT_EDNS0>
1629		2227
1630	Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension	2228	Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension for
1631	for DNS. This extension is generally useful to reduce DNS traffic, but	2229	DNS. This extension is generally useful to reduce DNS traffic, especially
1632	some (broken) firewalls drop such DNS packets, which is why it is off by	2230	when DNSSEC is involved, but some (broken) firewalls drop such DNS
1633	default.	2231	packets, which is why it is off by default.
1634		2232
1635	Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce	2233	Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce
1636	EDNS0 in its DNS requests.	2234	EDNS0 in its DNS requests.
1637		2235
1638	=item C<PERL_ANYEVENT_MAX_FORKS>	2236	=item C<PERL_ANYEVENT_MAX_FORKS>
…		…
1644		2242
1645	The default value for the C<max_outstanding> parameter for the default DNS	2243	The default value for the C<max_outstanding> parameter for the default DNS
1646	resolver - this is the maximum number of parallel DNS requests that are	2244	resolver - this is the maximum number of parallel DNS requests that are
1647	sent to the DNS server.	2245	sent to the DNS server.
1648		2246
		2247	=item C<PERL_ANYEVENT_MAX_SIGNAL_LATENCY>
		2248
		2249	Perl has inherently racy signal handling (you can basically choose between
		2250	losing signals and memory corruption) - pure perl event loops (including
		2251	C<AnyEvent::Loop>, when C<Async::Interrupt> isn't available) therefore
		2252	have to poll regularly to avoid losing signals.
		2253
		2254	Some event loops are racy, but don't poll regularly, and some event loops
		2255	are written in C but are still racy. For those event loops, AnyEvent
		2256	installs a timer that regularly wakes up the event loop.
		2257
		2258	By default, the interval for this timer is C<10> seconds, but you can
		2259	override this delay with this environment variable (or by setting
		2260	the C<$AnyEvent::MAX_SIGNAL_LATENCY> variable before creating signal
		2261	watchers).
		2262
		2263	Lower values increase CPU (and energy) usage, higher values can introduce
		2264	long delays when reaping children or waiting for signals.
		2265
		2266	The L<AnyEvent::Async> module, if available, will be used to avoid this
		2267	polling (with most event loops).
		2268
1649	=item C<PERL_ANYEVENT_RESOLV_CONF>	2269	=item C<PERL_ANYEVENT_RESOLV_CONF>
1650		2270
1651	The file to use instead of F</etc/resolv.conf> (or OS-specific	2271	The absolute path to a F<resolv.conf>-style file to use instead of
1652	configuration) in the default resolver. When set to the empty string, no	2272	F</etc/resolv.conf> (or the OS-specific configuration) in the default
1653	default config will be used.	2273	resolver, or the empty string to select the default configuration.
1654		2274
1655	=item C<PERL_ANYEVENT_CA_FILE>, C<PERL_ANYEVENT_CA_PATH>.	2275	=item C<PERL_ANYEVENT_CA_FILE>, C<PERL_ANYEVENT_CA_PATH>.
1656		2276
1657	When neither C<ca_file> nor C<ca_path> was specified during	2277	When neither C<ca_file> nor C<ca_path> was specified during
1658	L<AnyEvent::TLS> context creation, and either of these environment	2278	L<AnyEvent::TLS> context creation, and either of these environment
1659	variables exist, they will be used to specify CA certificate locations	2279	variables are nonempty, they will be used to specify CA certificate
1660	instead of a system-dependent default.	2280	locations instead of a system-dependent default.
1661		2281
1662	=item C<PERL_ANYEVENT_AVOID_GUARD> and C<PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT>	2282	=item C<PERL_ANYEVENT_AVOID_GUARD> and C<PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT>
1663		2283
1664	When these are set to C<1>, then the respective modules are not	2284	When these are set to C<1>, then the respective modules are not
1665	loaded. Mostly good for testing AnyEvent itself.	2285	loaded. Mostly good for testing AnyEvent itself.
…		…
1728	warn "read: $input\n"; # output what has been read	2348	warn "read: $input\n"; # output what has been read
1729	$cv->send if $input =~ /^q/i; # quit program if /^q/i	2349	$cv->send if $input =~ /^q/i; # quit program if /^q/i
1730	},	2350	},
1731	);	2351	);
1732		2352
1733	my $time_watcher; # can only be used once
1734
1735	sub new_timer {
1736	$timer = AnyEvent->timer (after => 1, cb => sub {	2353	my $time_watcher = AnyEvent->timer (after => 1, interval => 1, cb => sub {
1737	warn "timeout\n"; # print 'timeout' about every second	2354	warn "timeout\n"; # print 'timeout' at most every second
1738	&new_timer; # and restart the time
1739	});	2355	});
1740	}
1741
1742	new_timer; # create first timer
1743		2356
1744	$cv->recv; # wait until user enters /^q/i	2357	$cv->recv; # wait until user enters /^q/i
1745		2358
1746	=head1 REAL-WORLD EXAMPLE	2359	=head1 REAL-WORLD EXAMPLE
1747		2360
…		…
1820		2433
1821	The actual code goes further and collects all errors (C<die>s, exceptions)	2434	The actual code goes further and collects all errors (C<die>s, exceptions)
1822	that occurred during request processing. The C<result> method detects	2435	that occurred during request processing. The C<result> method detects
1823	whether an exception as thrown (it is stored inside the $txn object)	2436	whether an exception as thrown (it is stored inside the $txn object)
1824	and just throws the exception, which means connection errors and other	2437	and just throws the exception, which means connection errors and other
1825	problems get reported tot he code that tries to use the result, not in a	2438	problems get reported to the code that tries to use the result, not in a
1826	random callback.	2439	random callback.
1827		2440
1828	All of this enables the following usage styles:	2441	All of this enables the following usage styles:
1829		2442
1830	1. Blocking:	2443	1. Blocking:
…		…
1878	through AnyEvent. The benchmark creates a lot of timers (with a zero	2491	through AnyEvent. The benchmark creates a lot of timers (with a zero
1879	timeout) and I/O watchers (watching STDOUT, a pty, to become writable,	2492	timeout) and I/O watchers (watching STDOUT, a pty, to become writable,
1880	which it is), lets them fire exactly once and destroys them again.	2493	which it is), lets them fire exactly once and destroys them again.
1881		2494
1882	Source code for this benchmark is found as F<eg/bench> in the AnyEvent	2495	Source code for this benchmark is found as F<eg/bench> in the AnyEvent
1883	distribution.	2496	distribution. It uses the L<AE> interface, which makes a real difference
		2497	for the EV and Perl backends only.
1884		2498
1885	=head3 Explanation of the columns	2499	=head3 Explanation of the columns
1886		2500
1887	I<watcher> is the number of event watchers created/destroyed. Since	2501	I<watcher> is the number of event watchers created/destroyed. Since
1888	different event models feature vastly different performances, each event	2502	different event models feature vastly different performances, each event
…		…
1909	watcher.	2523	watcher.
1910		2524
1911	=head3 Results	2525	=head3 Results
1912		2526
1913	name watchers bytes create invoke destroy comment	2527	name watchers bytes create invoke destroy comment
1914	EV/EV 400000 224 0.47 0.35 0.27 EV native interface	2528	EV/EV 100000 223 0.47 0.43 0.27 EV native interface
1915	EV/Any 100000 224 2.88 0.34 0.27 EV + AnyEvent watchers	2529	EV/Any 100000 223 0.48 0.42 0.26 EV + AnyEvent watchers
1916	CoroEV/Any 100000 224 2.85 0.35 0.28 coroutines + Coro::Signal	2530	Coro::EV/Any 100000 223 0.47 0.42 0.26 coroutines + Coro::Signal
1917	Perl/Any 100000 452 4.13 0.73 0.95 pure perl implementation	2531	Perl/Any 100000 431 2.70 0.74 0.92 pure perl implementation
1918	Event/Event 16000 517 32.20 31.80 0.81 Event native interface	2532	Event/Event 16000 516 31.16 31.84 0.82 Event native interface
1919	Event/Any 16000 590 35.85 31.55 1.06 Event + AnyEvent watchers	2533	Event/Any 16000 1203 42.61 34.79 1.80 Event + AnyEvent watchers
1920	IOAsync/Any 16000 989 38.10 32.77 11.13 via IO::Async::Loop::IO_Poll	2534	IOAsync/Any 16000 1911 41.92 27.45 16.81 via IO::Async::Loop::IO_Poll
1921	IOAsync/Any 16000 990 37.59 29.50 10.61 via IO::Async::Loop::Epoll	2535	IOAsync/Any 16000 1726 40.69 26.37 15.25 via IO::Async::Loop::Epoll
1922	Glib/Any 16000 1357 102.33 12.31 51.00 quadratic behaviour	2536	Glib/Any 16000 1118 89.00 12.57 51.17 quadratic behaviour
1923	Tk/Any 2000 1860 27.20 66.31 14.00 SEGV with >> 2000 watchers	2537	Tk/Any 2000 1346 20.96 10.75 8.00 SEGV with >> 2000 watchers
1924	POE/Event 2000 6328 109.99 751.67 14.02 via POE::Loop::Event	2538	POE/Any 2000 6951 108.97 795.32 14.24 via POE::Loop::Event
1925	POE/Select 2000 6027 94.54 809.13 579.80 via POE::Loop::Select	2539	POE/Any 2000 6648 94.79 774.40 575.51 via POE::Loop::Select
1926		2540
1927	=head3 Discussion	2541	=head3 Discussion
1928		2542
1929	The benchmark does I<not> measure scalability of the event loop very	2543	The benchmark does I<not> measure scalability of the event loop very
1930	well. For example, a select-based event loop (such as the pure perl one)	2544	well. For example, a select-based event loop (such as the pure perl one)
…		…
1942	benchmark machine, handling an event takes roughly 1600 CPU cycles with	2556	benchmark machine, handling an event takes roughly 1600 CPU cycles with
1943	EV, 3100 CPU cycles with AnyEvent's pure perl loop and almost 3000000 CPU	2557	EV, 3100 CPU cycles with AnyEvent's pure perl loop and almost 3000000 CPU
1944	cycles with POE.	2558	cycles with POE.
1945		2559
1946	C<EV> is the sole leader regarding speed and memory use, which are both	2560	C<EV> is the sole leader regarding speed and memory use, which are both
1947	maximal/minimal, respectively. Even when going through AnyEvent, it uses	2561	maximal/minimal, respectively. When using the L<AE> API there is zero
		2562	overhead (when going through the AnyEvent API create is about 5-6 times
		2563	slower, with other times being equal, so still uses far less memory than
1948	far less memory than any other event loop and is still faster than Event	2564	any other event loop and is still faster than Event natively).
1949	natively.
1950		2565
1951	The pure perl implementation is hit in a few sweet spots (both the	2566	The pure perl implementation is hit in a few sweet spots (both the
1952	constant timeout and the use of a single fd hit optimisations in the perl	2567	constant timeout and the use of a single fd hit optimisations in the perl
1953	interpreter and the backend itself). Nevertheless this shows that it	2568	interpreter and the backend itself). Nevertheless this shows that it
1954	adds very little overhead in itself. Like any select-based backend its	2569	adds very little overhead in itself. Like any select-based backend its
…		…
2002	(even when used without AnyEvent), but most event loops have acceptable	2617	(even when used without AnyEvent), but most event loops have acceptable
2003	performance with or without AnyEvent.	2618	performance with or without AnyEvent.
2004		2619
2005	=item * The overhead AnyEvent adds is usually much smaller than the overhead of	2620	=item * The overhead AnyEvent adds is usually much smaller than the overhead of
2006	the actual event loop, only with extremely fast event loops such as EV	2621	the actual event loop, only with extremely fast event loops such as EV
2007	adds AnyEvent significant overhead.	2622	does AnyEvent add significant overhead.
2008		2623
2009	=item * You should avoid POE like the plague if you want performance or	2624	=item * You should avoid POE like the plague if you want performance or
2010	reasonable memory usage.	2625	reasonable memory usage.
2011		2626
2012	=back	2627	=back
…		…
2028	In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100	2643	In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100
2029	(1%) are active. This mirrors the activity of large servers with many	2644	(1%) are active. This mirrors the activity of large servers with many
2030	connections, most of which are idle at any one point in time.	2645	connections, most of which are idle at any one point in time.
2031		2646
2032	Source code for this benchmark is found as F<eg/bench2> in the AnyEvent	2647	Source code for this benchmark is found as F<eg/bench2> in the AnyEvent
2033	distribution.	2648	distribution. It uses the L<AE> interface, which makes a real difference
		2649	for the EV and Perl backends only.
2034		2650
2035	=head3 Explanation of the columns	2651	=head3 Explanation of the columns
2036		2652
2037	I<sockets> is the number of sockets, and twice the number of "servers" (as	2653	I<sockets> is the number of sockets, and twice the number of "servers" (as
2038	each server has a read and write socket end).	2654	each server has a read and write socket end).
…		…
2046	a new one that moves the timeout into the future.	2662	a new one that moves the timeout into the future.
2047		2663
2048	=head3 Results	2664	=head3 Results
2049		2665
2050	name sockets create request	2666	name sockets create request
2051	EV 20000 69.01 11.16	2667	EV 20000 62.66 7.99
2052	Perl 20000 73.32 35.87	2668	Perl 20000 68.32 32.64
2053	IOAsync 20000 157.00 98.14 epoll	2669	IOAsync 20000 174.06 101.15 epoll
2054	IOAsync 20000 159.31 616.06 poll	2670	IOAsync 20000 174.67 610.84 poll
2055	Event 20000 212.62 257.32	2671	Event 20000 202.69 242.91
2056	Glib 20000 651.16 1896.30	2672	Glib 20000 557.01 1689.52
2057	POE 20000 349.67 12317.24 uses POE::Loop::Event	2673	POE 20000 341.54 12086.32 uses POE::Loop::Event
2058		2674
2059	=head3 Discussion	2675	=head3 Discussion
2060		2676
2061	This benchmark I<does> measure scalability and overall performance of the	2677	This benchmark I<does> measure scalability and overall performance of the
2062	particular event loop.	2678	particular event loop.
…		…
2188	As you can see, the AnyEvent + EV combination even beats the	2804	As you can see, the AnyEvent + EV combination even beats the
2189	hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl	2805	hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl
2190	backend easily beats IO::Lambda and POE.	2806	backend easily beats IO::Lambda and POE.
2191		2807
2192	And even the 100% non-blocking version written using the high-level (and	2808	And even the 100% non-blocking version written using the high-level (and
2193	slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda by a	2809	slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda
2194	large margin, even though it does all of DNS, tcp-connect and socket I/O	2810	higher level ("unoptimised") abstractions by a large margin, even though
2195	in a non-blocking way.	2811	it does all of DNS, tcp-connect and socket I/O in a non-blocking way.
2196		2812
2197	The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and	2813	The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and
2198	F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are	2814	F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are
2199	part of the IO::lambda distribution and were used without any changes.	2815	part of the IO::Lambda distribution and were used without any changes.
2200		2816
2201		2817
2202	=head1 SIGNALS	2818	=head1 SIGNALS
2203		2819
2204	AnyEvent currently installs handlers for these signals:	2820	AnyEvent currently installs handlers for these signals:
…		…
2241	unless defined $SIG{PIPE};	2857	unless defined $SIG{PIPE};
2242		2858
2243	=head1 RECOMMENDED/OPTIONAL MODULES	2859	=head1 RECOMMENDED/OPTIONAL MODULES
2244		2860
2245	One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and	2861	One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and
2246	it's built-in modules) are required to use it.	2862	its built-in modules) are required to use it.
2247		2863
2248	That does not mean that AnyEvent won't take advantage of some additional	2864	That does not mean that AnyEvent won't take advantage of some additional
2249	modules if they are installed.	2865	modules if they are installed.
2250		2866
2251	This section epxlains which additional modules will be used, and how they	2867	This section explains which additional modules will be used, and how they
2252	affect AnyEvent's operetion.	2868	affect AnyEvent's operation.
2253		2869
2254	=over 4	2870	=over 4
2255		2871
2256	=item L<Async::Interrupt>	2872	=item L<Async::Interrupt>
2257		2873
2258	This slightly arcane module is used to implement fast signal handling: To	2874	This slightly arcane module is used to implement fast signal handling: To
2259	my knowledge, there is no way to do completely race-free and quick	2875	my knowledge, there is no way to do completely race-free and quick
2260	signal handling in pure perl. To ensure that signals still get	2876	signal handling in pure perl. To ensure that signals still get
2261	delivered, AnyEvent will start an interval timer to wake up perl (and	2877	delivered, AnyEvent will start an interval timer to wake up perl (and
2262	catch the signals) with soemd elay (default is 10 seconds, look for	2878	catch the signals) with some delay (default is 10 seconds, look for
2263	C<$AnyEvent::MAX_SIGNAL_LATENCY>).	2879	C<$AnyEvent::MAX_SIGNAL_LATENCY>).
2264		2880
2265	If this module is available, then it will be used to implement signal	2881	If this module is available, then it will be used to implement signal
2266	catching, which means that signals will not be delayed, and the event loop	2882	catching, which means that signals will not be delayed, and the event loop
2267	will not be interrupted regularly, which is more efficient (And good for	2883	will not be interrupted regularly, which is more efficient (and good for
2268	battery life on laptops).	2884	battery life on laptops).
2269		2885
2270	This affects not just the pure-perl event loop, but also other event loops	2886	This affects not just the pure-perl event loop, but also other event loops
2271	that have no signal handling on their own (e.g. Glib, Tk, Qt).	2887	that have no signal handling on their own (e.g. Glib, Tk, Qt).
		2888
		2889	Some event loops (POE, Event, Event::Lib) offer signal watchers natively,
		2890	and either employ their own workarounds (POE) or use AnyEvent's workaround
		2891	(using C<$AnyEvent::MAX_SIGNAL_LATENCY>). Installing L<Async::Interrupt>
		2892	does nothing for those backends.
2272		2893
2273	=item L<EV>	2894	=item L<EV>
2274		2895
2275	This module isn't really "optional", as it is simply one of the backend	2896	This module isn't really "optional", as it is simply one of the backend
2276	event loops that AnyEvent can use. However, it is simply the best event	2897	event loops that AnyEvent can use. However, it is simply the best event
…		…
2279	automatic timer adjustments even when no monotonic clock is available,	2900	automatic timer adjustments even when no monotonic clock is available,
2280	can take avdantage of advanced kernel interfaces such as C<epoll> and	2901	can take avdantage of advanced kernel interfaces such as C<epoll> and
2281	C<kqueue>, and is the fastest backend I<by far>. You can even embed	2902	C<kqueue>, and is the fastest backend I<by far>. You can even embed
2282	L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>).	2903	L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>).
2283		2904
		2905	If you only use backends that rely on another event loop (e.g. C<Tk>),
		2906	then this module will do nothing for you.
		2907
2284	=item L<Guard>	2908	=item L<Guard>
2285		2909
2286	The guard module, when used, will be used to implement	2910	The guard module, when used, will be used to implement
2287	C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a	2911	C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a
2288	lot less memory), but otherwise doesn't affect guard operation much. It is	2912	lot less memory), but otherwise doesn't affect guard operation much. It is
2289	purely used for performance.	2913	purely used for performance.
2290		2914
2291	=item L<JSON> and L<JSON::XS>	2915	=item L<JSON> and L<JSON::XS>
2292		2916
2293	This module is required when you want to read or write JSON data via	2917	One of these modules is required when you want to read or write JSON data
2294	L<AnyEvent::Handle>. It is also written in pure-perl, but can take	2918	via L<AnyEvent::Handle>. L<JSON> is also written in pure-perl, but can take
2295	advantage of the ulta-high-speed L<JSON::XS> module when it is installed.	2919	advantage of the ultra-high-speed L<JSON::XS> module when it is installed.
2296
2297	In fact, L<AnyEvent::Handle> will use L<JSON::XS> by default if it is
2298	installed.
2299		2920
2300	=item L<Net::SSLeay>	2921	=item L<Net::SSLeay>
2301		2922
2302	Implementing TLS/SSL in Perl is certainly interesting, but not very	2923	Implementing TLS/SSL in Perl is certainly interesting, but not very
2303	worthwhile: If this module is installed, then L<AnyEvent::Handle> (with	2924	worthwhile: If this module is installed, then L<AnyEvent::Handle> (with
2304	the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL.	2925	the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL.
2305		2926
2306	=item L<Time::HiRes>	2927	=item L<Time::HiRes>
2307		2928
2308	This module is part of perl since release 5.008. It will be used when the	2929	This module is part of perl since release 5.008. It will be used when the
2309	chosen event library does not come with a timing source on it's own. The	2930	chosen event library does not come with a timing source of its own. The
2310	pure-perl event loop (L<AnyEvent::Impl::Perl>) will additionally use it to	2931	pure-perl event loop (L<AnyEvent::Loop>) will additionally load it to
2311	try to use a monotonic clock for timing stability.	2932	try to use a monotonic clock for timing stability.
2312		2933
2313	=back	2934	=back
2314		2935
2315		2936
2316	=head1 FORK	2937	=head1 FORK
2317		2938
2318	Most event libraries are not fork-safe. The ones who are usually are	2939	Most event libraries are not fork-safe. The ones who are usually are
2319	because they rely on inefficient but fork-safe C<select> or C<poll>	2940	because they rely on inefficient but fork-safe C<select> or C<poll> calls
2320	calls. Only L<EV> is fully fork-aware.	2941	- higher performance APIs such as BSD's kqueue or the dreaded Linux epoll
		2942	are usually badly thought-out hacks that are incompatible with fork in
		2943	one way or another. Only L<EV> is fully fork-aware and ensures that you
		2944	continue event-processing in both parent and child (or both, if you know
		2945	what you are doing).
		2946
		2947	This means that, in general, you cannot fork and do event processing in
		2948	the child if the event library was initialised before the fork (which
		2949	usually happens when the first AnyEvent watcher is created, or the library
		2950	is loaded).
2321		2951
2322	If you have to fork, you must either do so I<before> creating your first	2952	If you have to fork, you must either do so I<before> creating your first
2323	watcher OR you must not use AnyEvent at all in the child OR you must do	2953	watcher OR you must not use AnyEvent at all in the child OR you must do
2324	something completely out of the scope of AnyEvent.	2954	something completely out of the scope of AnyEvent.
		2955
		2956	The problem of doing event processing in the parent I<and> the child
		2957	is much more complicated: even for backends that I<are> fork-aware or
		2958	fork-safe, their behaviour is not usually what you want: fork clones all
		2959	watchers, that means all timers, I/O watchers etc. are active in both
		2960	parent and child, which is almost never what you want. USing C<exec>
		2961	to start worker children from some kind of manage rprocess is usually
		2962	preferred, because it is much easier and cleaner, at the expense of having
		2963	to have another binary.
2325		2964
2326		2965
2327	=head1 SECURITY CONSIDERATIONS	2966	=head1 SECURITY CONSIDERATIONS
2328		2967
2329	AnyEvent can be forced to load any event model via	2968	AnyEvent can be forced to load any event model via
…		…
2359	pronounced).	2998	pronounced).
2360		2999
2361		3000
2362	=head1 SEE ALSO	3001	=head1 SEE ALSO
2363		3002
2364	Utility functions: L<AnyEvent::Util>.	3003	Tutorial/Introduction: L<AnyEvent::Intro>.
2365		3004
2366	Event modules: L<EV>, L<EV::Glib>, L<Glib::EV>, L<Event>, L<Glib::Event>,	3005	FAQ: L<AnyEvent::FAQ>.
2367	L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.	3006
		3007	Utility functions: L<AnyEvent::Util> (misc. grab-bag), L<AnyEvent::Log>
		3008	(simply logging).
		3009
		3010	Development/Debugging: L<AnyEvent::Strict> (stricter checking),
		3011	L<AnyEvent::Debug> (interactive shell, watcher tracing).
		3012
		3013	Supported event modules: L<AnyEvent::Loop>, L<EV>, L<EV::Glib>,
		3014	L<Glib::EV>, L<Event>, L<Glib::Event>, L<Glib>, L<Tk>, L<Event::Lib>,
		3015	L<Qt>, L<POE>, L<FLTK>.
2368		3016
2369	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,	3017	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,
2370	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,	3018	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,
2371	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,	3019	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,
2372	L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>.	3020	L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>, L<Anyevent::Impl::Irssi>,
		3021	L<AnyEvent::Impl::FLTK>.
2373		3022
2374	Non-blocking file handles, sockets, TCP clients and	3023	Non-blocking handles, pipes, stream sockets, TCP clients and
2375	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.	3024	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.
2376		3025
		3026	Asynchronous File I/O: L<AnyEvent::IO>.
		3027
2377	Asynchronous DNS: L<AnyEvent::DNS>.	3028	Asynchronous DNS: L<AnyEvent::DNS>.
2378		3029
2379	Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>,	3030	Thread support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>.
2380	L<Coro::Event>,
2381		3031
2382	Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::XMPP>,	3032	Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::IRC>,
2383	L<AnyEvent::HTTP>.	3033	L<AnyEvent::HTTP>.
2384		3034
2385		3035
2386	=head1 AUTHOR	3036	=head1 AUTHOR
2387		3037
2388	Marc Lehmann <schmorp@schmorp.de>	3038	Marc Lehmann <schmorp@schmorp.de>
2389	http://home.schmorp.de/	3039	http://anyevent.schmorp.de
2390		3040
2391	=cut	3041	=cut
2392		3042
2393	1	3043	1
2394		3044

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