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Revision 1.231 by root, Wed Jul 8 13:46:46 2009 UTC vs.
Revision 1.418 by root, Tue Jan 21 16:48:34 2014 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 {
…		…
245		271
246	Example 2: fire an event after 0.5 seconds, then roughly every second.	272	Example 2: fire an event after 0.5 seconds, then roughly every second.
247		273
248	my $w = AnyEvent->timer (after => 0.5, interval => 1, cb => sub {	274	my $w = AnyEvent->timer (after => 0.5, interval => 1, cb => sub {
249	warn "timeout\n";	275	warn "timeout\n";
250	};	276	});
251		277
252	=head3 TIMING ISSUES	278	=head3 TIMING ISSUES
253		279
254	There are two ways to handle timers: based on real time (relative, "fire	280	There are two ways to handle timers: based on real time (relative, "fire
255	in 10 seconds") and based on wallclock time (absolute, "fire at 12	281	in 10 seconds") and based on wallclock time (absolute, "fire at 12
…		…
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
…		…
361	invocation, and callback invocation will be synchronous. Synchronous means	396	invocation, and callback invocation will be synchronous. Synchronous means
362	that it might take a while until the signal gets handled by the process,	397	that it might take a while until the signal gets handled by the process,
363	but it is guaranteed not to interrupt any other callbacks.	398	but it is guaranteed not to interrupt any other callbacks.
364		399
365	The main advantage of using these watchers is that you can share a signal	400	The main advantage of using these watchers is that you can share a signal
366	between multiple watchers.	401	between multiple watchers, and AnyEvent will ensure that signals will not
		402	interrupt your program at bad times.
367		403
368	This watcher might use C<%SIG>, so programs overwriting those signals	404	This watcher might use C<%SIG> (depending on the event loop used),
369	directly will likely not work correctly.	405	so programs overwriting those signals directly will likely not work
		406	correctly.
370		407
371	Example: exit on SIGINT	408	Example: exit on SIGINT
372		409
373	my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });	410	my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });
374		411
		412	=head3 Restart Behaviour
		413
		414	While restart behaviour is up to the event loop implementation, most will
		415	not restart syscalls (that includes L<Async::Interrupt> and AnyEvent's
		416	pure perl implementation).
		417
		418	=head3 Safe/Unsafe Signals
		419
		420	Perl signals can be either "safe" (synchronous to opcode handling)
		421	or "unsafe" (asynchronous) - the former might delay signal delivery
		422	indefinitely, the latter might corrupt your memory.
		423
		424	AnyEvent signal handlers are, in addition, synchronous to the event loop,
		425	i.e. they will not interrupt your running perl program but will only be
		426	called as part of the normal event handling (just like timer, I/O etc.
		427	callbacks, too).
		428
		429	=head3 Signal Races, Delays and Workarounds
		430
		431	Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support
		432	attaching callbacks to signals in a generic way, which is a pity,
		433	as you cannot do race-free signal handling in perl, requiring
		434	C libraries for this. AnyEvent will try to do its best, which
		435	means in some cases, signals will be delayed. The maximum time
		436	a signal might be delayed is 10 seconds by default, but can
		437	be overriden via C<$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
375	=head2 CHILD PROCESS WATCHERS	447	=head2 CHILD PROCESS WATCHERS
376		448
		449	$w = AnyEvent->child (pid => <process id>, cb => <callback>);
		450
377	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.
378		452
379	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,
380	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
381	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
382	any trace events (stopped/continued).	456	finished and an exit status is available, not on any trace events
		457	(stopped/continued).
383		458
384	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
385	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
386	callback arguments.	461	callback arguments.
387		462
…		…
404	This means you cannot create a child watcher as the very first	479	This means you cannot create a child watcher as the very first
405	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
406	watcher before you C<fork> the child (alternatively, you can call	481	watcher before you C<fork> the child (alternatively, you can call
407	C<AnyEvent::detect>).	482	C<AnyEvent::detect>).
408		483
		484	As most event loops do not support waiting for child events, they will be
		485	emulated by AnyEvent in most cases, in which case the latency and race
		486	problems mentioned in the description of signal watchers apply.
		487
409	Example: fork a process and wait for it	488	Example: fork a process and wait for it
410		489
411	my $done = AnyEvent->condvar;	490	my $done = AnyEvent->condvar;
412		491
		492	# this forks and immediately calls exit in the child. this
		493	# normally has all sorts of bad consequences for your parent,
		494	# so take this as an example only. always fork and exec,
		495	# or call POSIX::_exit, in real code.
413	my $pid = fork or exit 5;	496	my $pid = fork or exit 5;
414		497
415	my $w = AnyEvent->child (	498	my $w = AnyEvent->child (
416	pid => $pid,	499	pid => $pid,
417	cb => sub {	500	cb => sub {
…		…
424	# do something else, then wait for process exit	507	# do something else, then wait for process exit
425	$done->recv;	508	$done->recv;
426		509
427	=head2 IDLE WATCHERS	510	=head2 IDLE WATCHERS
428		511
429	Sometimes there is a need to do something, but it is not so important	512	$w = AnyEvent->idle (cb => <callback>);
430	to do it instantly, but only when there is nothing better to do. This
431	"nothing better to do" is usually defined to be "no other events need
432	attention by the event loop".
433		513
434	Idle watchers ideally get invoked when the event loop has nothing	514	This will repeatedly invoke the callback after the process becomes idle,
435	better to do, just before it would block the process to wait for new	515	until either the watcher is destroyed or new events have been detected.
436	events. Instead of blocking, the idle watcher is invoked.
437		516
438	Most event loops unfortunately do not really support idle watchers (only	517	Idle watchers are useful when there is a need to do something, but it
		518	is not so important (or wise) to do it instantly. The callback will be
		519	invoked only when there is "nothing better to do", which is usually
		520	defined as "all outstanding events have been handled and no new events
		521	have been detected". That means that idle watchers ideally get invoked
		522	when the event loop has just polled for new events but none have been
		523	detected. Instead of blocking to wait for more events, the idle watchers
		524	will be invoked.
		525
		526	Unfortunately, most event loops do not really support idle watchers (only
439	EV, Event and Glib do it in a usable fashion) - for the rest, AnyEvent	527	EV, Event and Glib do it in a usable fashion) - for the rest, AnyEvent
440	will simply call the callback "from time to time".	528	will simply call the callback "from time to time".
441		529
442	Example: read lines from STDIN, but only process them when the	530	Example: read lines from STDIN, but only process them when the
443	program is otherwise idle:	531	program is otherwise idle:
…		…
459	});	547	});
460	});	548	});
461		549
462	=head2 CONDITION VARIABLES	550	=head2 CONDITION VARIABLES
463		551
		552	$cv = AnyEvent->condvar;
		553
		554	$cv->send (<list>);
		555	my @res = $cv->recv;
		556
464	If you are familiar with some event loops you will know that all of them	557	If you are familiar with some event loops you will know that all of them
465	require you to run some blocking "loop", "run" or similar function that	558	require you to run some blocking "loop", "run" or similar function that
466	will actively watch for new events and call your callbacks.	559	will actively watch for new events and call your callbacks.
467		560
468	AnyEvent is different, it expects somebody else to run the event loop and	561	AnyEvent is slightly different: it expects somebody else to run the event
469	will only block when necessary (usually when told by the user).	562	loop and will only block when necessary (usually when told by the user).
470		563
471	The instrument to do that is called a "condition variable", so called	564	The tool to do that is called a "condition variable", so called because
472	because they represent a condition that must become true.	565	they represent a condition that must become true.
		566
		567	Now is probably a good time to look at the examples further below.
473		568
474	Condition variables can be created by calling the C<< AnyEvent->condvar	569	Condition variables can be created by calling the C<< AnyEvent->condvar
475	>> method, usually without arguments. The only argument pair allowed is	570	>> method, usually without arguments. The only argument pair allowed is
476
477	C<cb>, which specifies a callback to be called when the condition variable	571	C<cb>, which specifies a callback to be called when the condition variable
478	becomes true, with the condition variable as the first argument (but not	572	becomes true, with the condition variable as the first argument (but not
479	the results).	573	the results).
480		574
481	After creation, the condition variable is "false" until it becomes "true"	575	After creation, the condition variable is "false" until it becomes "true"
482	by calling the C<send> method (or calling the condition variable as if it	576	by calling the C<send> method (or calling the condition variable as if it
483	were a callback, read about the caveats in the description for the C<<	577	were a callback, read about the caveats in the description for the C<<
484	->send >> method).	578	->send >> method).
485		579
486	Condition variables are similar to callbacks, except that you can	580	Since condition variables are the most complex part of the AnyEvent API, here are
487	optionally wait for them. They can also be called merge points - points	581	some different mental models of what they are - pick the ones you can connect to:
488	in time where multiple outstanding events have been processed. And yet	582
489	another way to call them is transactions - each condition variable can be	583	=over 4
490	used to represent a transaction, which finishes at some point and delivers	584
491	a result.	585	=item * Condition variables are like callbacks - you can call them (and pass them instead
		586	of callbacks). Unlike callbacks however, you can also wait for them to be called.
		587
		588	=item * Condition variables are signals - one side can emit or send them,
		589	the other side can wait for them, or install a handler that is called when
		590	the signal fires.
		591
		592	=item * Condition variables are like "Merge Points" - points in your program
		593	where you merge multiple independent results/control flows into one.
		594
		595	=item * Condition variables represent a transaction - functions that start
		596	some kind of transaction can return them, leaving the caller the choice
		597	between waiting in a blocking fashion, or setting a callback.
		598
		599	=item * Condition variables represent future values, or promises to deliver
		600	some result, long before the result is available.
		601
		602	=back
492		603
493	Condition variables are very useful to signal that something has finished,	604	Condition variables are very useful to signal that something has finished,
494	for example, if you write a module that does asynchronous http requests,	605	for example, if you write a module that does asynchronous http requests,
495	then a condition variable would be the ideal candidate to signal the	606	then a condition variable would be the ideal candidate to signal the
496	availability of results. The user can either act when the callback is	607	availability of results. The user can either act when the callback is
…		…
509		620
510	Condition variables are represented by hash refs in perl, and the keys	621	Condition variables are represented by hash refs in perl, and the keys
511	used by AnyEvent itself are all named C<_ae_XXX> to make subclassing	622	used by AnyEvent itself are all named C<_ae_XXX> to make subclassing
512	easy (it is often useful to build your own transaction class on top of	623	easy (it is often useful to build your own transaction class on top of
513	AnyEvent). To subclass, use C<AnyEvent::CondVar> as base class and call	624	AnyEvent). To subclass, use C<AnyEvent::CondVar> as base class and call
514	it's C<new> method in your own C<new> method.	625	its C<new> method in your own C<new> method.
515		626
516	There are two "sides" to a condition variable - the "producer side" which	627	There are two "sides" to a condition variable - the "producer side" which
517	eventually calls C<< -> send >>, and the "consumer side", which waits	628	eventually calls C<< -> send >>, and the "consumer side", which waits
518	for the send to occur.	629	for the send to occur.
519		630
520	Example: wait for a timer.	631	Example: wait for a timer.
521		632
522	# wait till the result is ready	633	# condition: "wait till the timer is fired"
523	my $result_ready = AnyEvent->condvar;	634	my $timer_fired = AnyEvent->condvar;
524		635
525	# do something such as adding a timer	636	# create the timer - we could wait for, say
526	# or socket watcher the calls $result_ready->send	637	# a handle becomign ready, or even an
527	# when the "result" is ready.	638	# AnyEvent::HTTP request to finish, but
528	# in this case, we simply use a timer:	639	# in this case, we simply use a timer:
529	my $w = AnyEvent->timer (	640	my $w = AnyEvent->timer (
530	after => 1,	641	after => 1,
531	cb => sub { $result_ready->send },	642	cb => sub { $timer_fired->send },
532	);	643	);
533		644
534	# this "blocks" (while handling events) till the callback	645	# this "blocks" (while handling events) till the callback
535	# calls send	646	# calls ->send
536	$result_ready->recv;	647	$timer_fired->recv;
537		648
538	Example: wait for a timer, but take advantage of the fact that	649	Example: wait for a timer, but take advantage of the fact that condition
539	condition variables are also code references.	650	variables are also callable directly.
540		651
541	my $done = AnyEvent->condvar;	652	my $done = AnyEvent->condvar;
542	my $delay = AnyEvent->timer (after => 5, cb => $done);	653	my $delay = AnyEvent->timer (after => 5, cb => $done);
543	$done->recv;	654	$done->recv;
544		655
…		…
550		661
551	...	662	...
552		663
553	my @info = $couchdb->info->recv;	664	my @info = $couchdb->info->recv;
554		665
555	And this is how you would just ste a callback to be called whenever the	666	And this is how you would just set a callback to be called whenever the
556	results are available:	667	results are available:
557		668
558	$couchdb->info->cb (sub {	669	$couchdb->info->cb (sub {
559	my @info = $_[0]->recv;	670	my @info = $_[0]->recv;
560	});	671	});
…		…
578	immediately from within send.	689	immediately from within send.
579		690
580	Any arguments passed to the C<send> call will be returned by all	691	Any arguments passed to the C<send> call will be returned by all
581	future C<< ->recv >> calls.	692	future C<< ->recv >> calls.
582		693
583	Condition variables are overloaded so one can call them directly	694	Condition variables are overloaded so one can call them directly (as if
584	(as a code reference). Calling them directly is the same as calling	695	they were a code reference). Calling them directly is the same as calling
585	C<send>. Note, however, that many C-based event loops do not handle	696	C<send>.
586	overloading, so as tempting as it may be, passing a condition variable
587	instead of a callback does not work. Both the pure perl and EV loops
588	support overloading, however, as well as all functions that use perl to
589	invoke a callback (as in L<AnyEvent::Socket> and L<AnyEvent::DNS> for
590	example).
591		697
592	=item $cv->croak ($error)	698	=item $cv->croak ($error)
593		699
594	Similar to send, but causes all call's to C<< ->recv >> to invoke	700	Similar to send, but causes all calls to C<< ->recv >> to invoke
595	C<Carp::croak> with the given error message/object/scalar.	701	C<Carp::croak> with the given error message/object/scalar.
596		702
597	This can be used to signal any errors to the condition variable	703	This can be used to signal any errors to the condition variable
598	user/consumer.	704	user/consumer. Doing it this way instead of calling C<croak> directly
		705	delays the error detection, but has the overwhelming advantage that it
		706	diagnoses the error at the place where the result is expected, and not
		707	deep in some event callback with no connection to the actual code causing
		708	the problem.
599		709
600	=item $cv->begin ([group callback])	710	=item $cv->begin ([group callback])
601		711
602	=item $cv->end	712	=item $cv->end
603		713
…		…
605	one. For example, a function that pings many hosts in parallel might want	715	one. For example, a function that pings many hosts in parallel might want
606	to use a condition variable for the whole process.	716	to use a condition variable for the whole process.
607		717
608	Every call to C<< ->begin >> will increment a counter, and every call to	718	Every call to C<< ->begin >> will increment a counter, and every call to
609	C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end	719	C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end
610	>>, the (last) callback passed to C<begin> will be executed. That callback	720	>>, the (last) callback passed to C<begin> will be executed, passing the
611	is I<supposed> to call C<< ->send >>, but that is not required. If no	721	condvar as first argument. That callback is I<supposed> to call C<< ->send
612	callback was set, C<send> will be called without any arguments.	722	>>, but that is not required. If no group callback was set, C<send> will
		723	be called without any arguments.
613		724
614	You can think of C<< $cv->send >> giving you an OR condition (one call	725	You can think of C<< $cv->send >> giving you an OR condition (one call
615	sends), while C<< $cv->begin >> and C<< $cv->end >> giving you an AND	726	sends), while C<< $cv->begin >> and C<< $cv->end >> giving you an AND
616	condition (all C<begin> calls must be C<end>'ed before the condvar sends).	727	condition (all C<begin> calls must be C<end>'ed before the condvar sends).
617		728
…		…
638	This works because for every event source (EOF on file handle), there is	749	This works because for every event source (EOF on file handle), there is
639	one call to C<begin>, so the condvar waits for all calls to C<end> before	750	one call to C<begin>, so the condvar waits for all calls to C<end> before
640	sending.	751	sending.
641		752
642	The ping example mentioned above is slightly more complicated, as the	753	The ping example mentioned above is slightly more complicated, as the
643	there are results to be passwd back, and the number of tasks that are	754	there are results to be passed back, and the number of tasks that are
644	begung can potentially be zero:	755	begun can potentially be zero:
645		756
646	my $cv = AnyEvent->condvar;	757	my $cv = AnyEvent->condvar;
647		758
648	my %result;	759	my %result;
649	$cv->begin (sub { $cv->send (\%result) });	760	$cv->begin (sub { shift->send (\%result) });
650		761
651	for my $host (@list_of_hosts) {	762	for my $host (@list_of_hosts) {
652	$cv->begin;	763	$cv->begin;
653	ping_host_then_call_callback $host, sub {	764	ping_host_then_call_callback $host, sub {
654	$result{$host} = ...;	765	$result{$host} = ...;
…		…
656	};	767	};
657	}	768	}
658		769
659	$cv->end;	770	$cv->end;
660		771
		772	...
		773
		774	my $results = $cv->recv;
		775
661	This code fragment supposedly pings a number of hosts and calls	776	This code fragment supposedly pings a number of hosts and calls
662	C<send> after results for all then have have been gathered - in any	777	C<send> after results for all then have have been gathered - in any
663	order. To achieve this, the code issues a call to C<begin> when it starts	778	order. To achieve this, the code issues a call to C<begin> when it starts
664	each ping request and calls C<end> when it has received some result for	779	each ping request and calls C<end> when it has received some result for
665	it. Since C<begin> and C<end> only maintain a counter, the order in which	780	it. Since C<begin> and C<end> only maintain a counter, the order in which
…		…
670	to be called once the counter reaches C<0>, and second, it ensures that	785	to be called once the counter reaches C<0>, and second, it ensures that
671	C<send> is called even when C<no> hosts are being pinged (the loop	786	C<send> is called even when C<no> hosts are being pinged (the loop
672	doesn't execute once).	787	doesn't execute once).
673		788
674	This is the general pattern when you "fan out" into multiple (but	789	This is the general pattern when you "fan out" into multiple (but
675	potentially none) subrequests: use an outer C<begin>/C<end> pair to set	790	potentially zero) subrequests: use an outer C<begin>/C<end> pair to set
676	the callback and ensure C<end> is called at least once, and then, for each	791	the callback and ensure C<end> is called at least once, and then, for each
677	subrequest you start, call C<begin> and for each subrequest you finish,	792	subrequest you start, call C<begin> and for each subrequest you finish,
678	call C<end>.	793	call C<end>.
679		794
680	=back	795	=back
…		…
687	=over 4	802	=over 4
688		803
689	=item $cv->recv	804	=item $cv->recv
690		805
691	Wait (blocking if necessary) until the C<< ->send >> or C<< ->croak	806	Wait (blocking if necessary) until the C<< ->send >> or C<< ->croak
692	>> methods have been called on c<$cv>, while servicing other watchers	807	>> methods have been called on C<$cv>, while servicing other watchers
693	normally.	808	normally.
694		809
695	You can only wait once on a condition - additional calls are valid but	810	You can only wait once on a condition - additional calls are valid but
696	will return immediately.	811	will return immediately.
697		812
…		…
699	function will call C<croak>.	814	function will call C<croak>.
700		815
701	In list context, all parameters passed to C<send> will be returned,	816	In list context, all parameters passed to C<send> will be returned,
702	in scalar context only the first one will be returned.	817	in scalar context only the first one will be returned.
703		818
		819	Note that doing a blocking wait in a callback is not supported by any
		820	event loop, that is, recursive invocation of a blocking C<< ->recv >> is
		821	not allowed and the C<recv> call will C<croak> if such a condition is
		822	detected. This requirement can be dropped by relying on L<Coro::AnyEvent>
		823	, which allows you to do a blocking C<< ->recv >> from any thread
		824	that doesn't run the event loop itself. L<Coro::AnyEvent> is loaded
		825	automatically when L<Coro> is used with L<AnyEvent>, so code does not need
		826	to do anything special to take advantage of that: any code that would
		827	normally block your program because it calls C<recv>, be executed in an
		828	C<async> thread instead without blocking other threads.
		829
704	Not all event models support a blocking wait - some die in that case	830	Not all event models support a blocking wait - some die in that case
705	(programs might want to do that to stay interactive), so I<if you are	831	(programs might want to do that to stay interactive), so I<if you are
706	using this from a module, never require a blocking wait>, but let the	832	using this from a module, never require a blocking wait>. Instead, let the
707	caller decide whether the call will block or not (for example, by coupling	833	caller decide whether the call will block or not (for example, by coupling
708	condition variables with some kind of request results and supporting	834	condition variables with some kind of request results and supporting
709	callbacks so the caller knows that getting the result will not block,	835	callbacks so the caller knows that getting the result will not block,
710	while still supporting blocking waits if the caller so desires).	836	while still supporting blocking waits if the caller so desires).
711		837
712	Another reason I<never> to C<< ->recv >> in a module is that you cannot
713	sensibly have two C<< ->recv >>'s in parallel, as that would require
714	multiple interpreters or coroutines/threads, none of which C<AnyEvent>
715	can supply.
716
717	The L<Coro> module, however, I<can> and I<does> supply coroutines and, in
718	fact, L<Coro::AnyEvent> replaces AnyEvent's condvars by coroutine-safe
719	versions and also integrates coroutines into AnyEvent, making blocking
720	C<< ->recv >> calls perfectly safe as long as they are done from another
721	coroutine (one that doesn't run the event loop).
722
723	You can ensure that C<< -recv >> never blocks by setting a callback and	838	You can ensure that C<< ->recv >> never blocks by setting a callback and
724	only calling C<< ->recv >> from within that callback (or at a later	839	only calling C<< ->recv >> from within that callback (or at a later
725	time). This will work even when the event loop does not support blocking	840	time). This will work even when the event loop does not support blocking
726	waits otherwise.	841	waits otherwise.
727		842
728	=item $bool = $cv->ready	843	=item $bool = $cv->ready
…		…
734		849
735	This is a mutator function that returns the callback set and optionally	850	This is a mutator function that returns the callback set and optionally
736	replaces it before doing so.	851	replaces it before doing so.
737		852
738	The callback will be called when the condition becomes "true", i.e. when	853	The callback will be called when the condition becomes "true", i.e. when
739	C<send> or C<croak> are called, with the only argument being the condition	854	C<send> or C<croak> are called, with the only argument being the
740	variable itself. Calling C<recv> inside the callback or at any later time	855	condition variable itself. If the condition is already true, the
741	is guaranteed not to block.	856	callback is called immediately when it is set. Calling C<recv> inside
		857	the callback or at any later time is guaranteed not to block.
742		858
743	=back	859	=back
744		860
		861	=head1 SUPPORTED EVENT LOOPS/BACKENDS
		862
		863	The available backend classes are (every class has its own manpage):
		864
		865	=over 4
		866
		867	=item Backends that are autoprobed when no other event loop can be found.
		868
		869	EV is the preferred backend when no other event loop seems to be in
		870	use. If EV is not installed, then AnyEvent will fall back to its own
		871	pure-perl implementation, which is available everywhere as it comes with
		872	AnyEvent itself.
		873
		874	AnyEvent::Impl::EV based on EV (interface to libev, best choice).
		875	AnyEvent::Impl::Perl pure-perl AnyEvent::Loop, fast and portable.
		876
		877	=item Backends that are transparently being picked up when they are used.
		878
		879	These will be used if they are already loaded when the first watcher
		880	is created, in which case it is assumed that the application is using
		881	them. This means that AnyEvent will automatically pick the right backend
		882	when the main program loads an event module before anything starts to
		883	create watchers. Nothing special needs to be done by the main program.
		884
		885	AnyEvent::Impl::Event based on Event, very stable, few glitches.
		886	AnyEvent::Impl::Glib based on Glib, slow but very stable.
		887	AnyEvent::Impl::Tk based on Tk, very broken.
		888	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
		889	AnyEvent::Impl::POE based on POE, very slow, some limitations.
		890	AnyEvent::Impl::Irssi used when running within irssi.
		891	AnyEvent::Impl::IOAsync based on IO::Async.
		892	AnyEvent::Impl::Cocoa based on Cocoa::EventLoop.
		893	AnyEvent::Impl::FLTK based on FLTK (fltk 2 binding).
		894
		895	=item Backends with special needs.
		896
		897	Qt requires the Qt::Application to be instantiated first, but will
		898	otherwise be picked up automatically. As long as the main program
		899	instantiates the application before any AnyEvent watchers are created,
		900	everything should just work.
		901
		902	AnyEvent::Impl::Qt based on Qt.
		903
		904	=item Event loops that are indirectly supported via other backends.
		905
		906	Some event loops can be supported via other modules:
		907
		908	There is no direct support for WxWidgets (L<Wx>) or L<Prima>.
		909
		910	B<WxWidgets> has no support for watching file handles. However, you can
		911	use WxWidgets through the POE adaptor, as POE has a Wx backend that simply
		912	polls 20 times per second, which was considered to be too horrible to even
		913	consider for AnyEvent.
		914
		915	B<Prima> is not supported as nobody seems to be using it, but it has a POE
		916	backend, so it can be supported through POE.
		917
		918	AnyEvent knows about both L<Prima> and L<Wx>, however, and will try to
		919	load L<POE> when detecting them, in the hope that POE will pick them up,
		920	in which case everything will be automatic.
		921
		922	=back
		923
745	=head1 GLOBAL VARIABLES AND FUNCTIONS	924	=head1 GLOBAL VARIABLES AND FUNCTIONS
746		925
		926	These are not normally required to use AnyEvent, but can be useful to
		927	write AnyEvent extension modules.
		928
747	=over 4	929	=over 4
748		930
749	=item $AnyEvent::MODEL	931	=item $AnyEvent::MODEL
750		932
751	Contains C<undef> until the first watcher is being created. Then it	933	Contains C<undef> until the first watcher is being created, before the
		934	backend has been autodetected.
		935
752	contains the event model that is being used, which is the name of the	936	Afterwards it contains the event model that is being used, which is the
753	Perl class implementing the model. This class is usually one of the	937	name of the Perl class implementing the model. This class is usually one
754	C<AnyEvent::Impl:xxx> modules, but can be any other class in the case	938	of the C<AnyEvent::Impl::xxx> modules, but can be any other class in the
755	AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode>).	939	case AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode> it
756		940	will be C<urxvt::anyevent>).
757	The known classes so far are:
758
759	AnyEvent::Impl::EV based on EV (an interface to libev, best choice).
760	AnyEvent::Impl::Event based on Event, second best choice.
761	AnyEvent::Impl::Perl pure-perl implementation, fast and portable.
762	AnyEvent::Impl::Glib based on Glib, third-best choice.
763	AnyEvent::Impl::Tk based on Tk, very bad choice.
764	AnyEvent::Impl::Qt based on Qt, cannot be autoprobed (see its docs).
765	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
766	AnyEvent::Impl::POE based on POE, not generic enough for full support.
767
768	# warning, support for IO::Async is only partial, as it is too broken
769	# and limited toe ven support the AnyEvent API. See AnyEvent::Impl::Async.
770	AnyEvent::Impl::IOAsync based on IO::Async, cannot be autoprobed (see its docs).
771
772	There is no support for WxWidgets, as WxWidgets has no support for
773	watching file handles. However, you can use WxWidgets through the
774	POE Adaptor, as POE has a Wx backend that simply polls 20 times per
775	second, which was considered to be too horrible to even consider for
776	AnyEvent. Likewise, other POE backends can be used by AnyEvent by using
777	it's adaptor.
778
779	AnyEvent knows about L<Prima> and L<Wx> and will try to use L<POE> when
780	autodetecting them.
781		941
782	=item AnyEvent::detect	942	=item AnyEvent::detect
783		943
784	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model	944	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model
785	if necessary. You should only call this function right before you would	945	if necessary. You should only call this function right before you would
786	have created an AnyEvent watcher anyway, that is, as late as possible at	946	have created an AnyEvent watcher anyway, that is, as late as possible at
787	runtime.	947	runtime, and not e.g. during initialisation of your module.
		948
		949	The effect of calling this function is as if a watcher had been created
		950	(specifically, actions that happen "when the first watcher is created"
		951	happen when calling detetc as well).
		952
		953	If you need to do some initialisation before AnyEvent watchers are
		954	created, use C<post_detect>.
788		955
789	=item $guard = AnyEvent::post_detect { BLOCK }	956	=item $guard = AnyEvent::post_detect { BLOCK }
790		957
791	Arranges for the code block to be executed as soon as the event model is	958	Arranges for the code block to be executed as soon as the event model is
792	autodetected (or immediately if this has already happened).	959	autodetected (or immediately if that has already happened).
		960
		961	The block will be executed I<after> the actual backend has been detected
		962	(C<$AnyEvent::MODEL> is set), but I<before> any watchers have been
		963	created, so it is possible to e.g. patch C<@AnyEvent::ISA> or do
		964	other initialisations - see the sources of L<AnyEvent::Strict> or
		965	L<AnyEvent::AIO> to see how this is used.
		966
		967	The most common usage is to create some global watchers, without forcing
		968	event module detection too early, for example, L<AnyEvent::AIO> creates
		969	and installs the global L<IO::AIO> watcher in a C<post_detect> block to
		970	avoid autodetecting the event module at load time.
793		971
794	If called in scalar or list context, then it creates and returns an object	972	If called in scalar or list context, then it creates and returns an object
795	that automatically removes the callback again when it is destroyed. See	973	that automatically removes the callback again when it is destroyed (or
		974	C<undef> when the hook was immediately executed). See L<AnyEvent::AIO> for
796	L<Coro::BDB> for a case where this is useful.	975	a case where this is useful.
		976
		977	Example: Create a watcher for the IO::AIO module and store it in
		978	C<$WATCHER>, but do so only do so after the event loop is initialised.
		979
		980	our WATCHER;
		981
		982	my $guard = AnyEvent::post_detect {
		983	$WATCHER = AnyEvent->io (fh => IO::AIO::poll_fileno, poll => 'r', cb => \&IO::AIO::poll_cb);
		984	};
		985
		986	# the ||= is important in case post_detect immediately runs the block,
		987	# as to not clobber the newly-created watcher. assigning both watcher and
		988	# post_detect guard to the same variable has the advantage of users being
		989	# able to just C<undef $WATCHER> if the watcher causes them grief.
		990
		991	$WATCHER ||= $guard;
797		992
798	=item @AnyEvent::post_detect	993	=item @AnyEvent::post_detect
799		994
800	If there are any code references in this array (you can C<push> to it	995	If there are any code references in this array (you can C<push> to it
801	before or after loading AnyEvent), then they will called directly after	996	before or after loading AnyEvent), then they will be called directly
802	the event loop has been chosen.	997	after the event loop has been chosen.
803		998
804	You should check C<$AnyEvent::MODEL> before adding to this array, though:	999	You should check C<$AnyEvent::MODEL> before adding to this array, though:
805	if it contains a true value then the event loop has already been detected,	1000	if it is defined then the event loop has already been detected, and the
806	and the array will be ignored.	1001	array will be ignored.
807		1002
808	Best use C<AnyEvent::post_detect { BLOCK }> instead.	1003	Best use C<AnyEvent::post_detect { BLOCK }> when your application allows
		1004	it, as it takes care of these details.
		1005
		1006	This variable is mainly useful for modules that can do something useful
		1007	when AnyEvent is used and thus want to know when it is initialised, but do
		1008	not need to even load it by default. This array provides the means to hook
		1009	into AnyEvent passively, without loading it.
		1010
		1011	Example: To load Coro::AnyEvent whenever Coro and AnyEvent are used
		1012	together, you could put this into Coro (this is the actual code used by
		1013	Coro to accomplish this):
		1014
		1015	if (defined $AnyEvent::MODEL) {
		1016	# AnyEvent already initialised, so load Coro::AnyEvent
		1017	require Coro::AnyEvent;
		1018	} else {
		1019	# AnyEvent not yet initialised, so make sure to load Coro::AnyEvent
		1020	# as soon as it is
		1021	push @AnyEvent::post_detect, sub { require Coro::AnyEvent };
		1022	}
		1023
		1024	=item AnyEvent::postpone { BLOCK }
		1025
		1026	Arranges for the block to be executed as soon as possible, but not before
		1027	the call itself returns. In practise, the block will be executed just
		1028	before the event loop polls for new events, or shortly afterwards.
		1029
		1030	This function never returns anything (to make the C<return postpone { ...
		1031	}> idiom more useful.
		1032
		1033	To understand the usefulness of this function, consider a function that
		1034	asynchronously does something for you and returns some transaction
		1035	object or guard to let you cancel the operation. For example,
		1036	C<AnyEvent::Socket::tcp_connect>:
		1037
		1038	# start a connection attempt unless one is active
		1039	$self->{connect_guard} ||= AnyEvent::Socket::tcp_connect "www.example.net", 80, sub {
		1040	delete $self->{connect_guard};
		1041	...
		1042	};
		1043
		1044	Imagine that this function could instantly call the callback, for
		1045	example, because it detects an obvious error such as a negative port
		1046	number. Invoking the callback before the function returns causes problems
		1047	however: the callback will be called and will try to delete the guard
		1048	object. But since the function hasn't returned yet, there is nothing to
		1049	delete. When the function eventually returns it will assign the guard
		1050	object to C<< $self->{connect_guard} >>, where it will likely never be
		1051	deleted, so the program thinks it is still trying to connect.
		1052
		1053	This is where C<AnyEvent::postpone> should be used. Instead of calling the
		1054	callback directly on error:
		1055
		1056	$cb->(undef), return # signal error to callback, BAD!
		1057	if $some_error_condition;
		1058
		1059	It should use C<postpone>:
		1060
		1061	AnyEvent::postpone { $cb->(undef) }, return # signal error to callback, later
		1062	if $some_error_condition;
		1063
		1064	=item AnyEvent::log $level, $msg[, @args]
		1065
		1066	Log the given C<$msg> at the given C<$level>.
		1067
		1068	If L<AnyEvent::Log> is not loaded then this function makes a simple test
		1069	to see whether the message will be logged. If the test succeeds it will
		1070	load AnyEvent::Log and call C<AnyEvent::Log::log> - consequently, look at
		1071	the L<AnyEvent::Log> documentation for details.
		1072
		1073	If the test fails it will simply return. Right now this happens when a
		1074	numerical loglevel is used and it is larger than the level specified via
		1075	C<$ENV{PERL_ANYEVENT_VERBOSE}>.
		1076
		1077	If you want to sprinkle loads of logging calls around your code, consider
		1078	creating a logger callback with the C<AnyEvent::Log::logger> function,
		1079	which can reduce typing, codesize and can reduce the logging overhead
		1080	enourmously.
809		1081
810	=back	1082	=back
811		1083
812	=head1 WHAT TO DO IN A MODULE	1084	=head1 WHAT TO DO IN A MODULE
813		1085
…		…
824	because it will stall the whole program, and the whole point of using	1096	because it will stall the whole program, and the whole point of using
825	events is to stay interactive.	1097	events is to stay interactive.
826		1098
827	It is fine, however, to call C<< ->recv >> when the user of your module	1099	It is fine, however, to call C<< ->recv >> when the user of your module
828	requests it (i.e. if you create a http request object ad have a method	1100	requests it (i.e. if you create a http request object ad have a method
829	called C<results> that returns the results, it should call C<< ->recv >>	1101	called C<results> that returns the results, it may call C<< ->recv >>
830	freely, as the user of your module knows what she is doing. always).	1102	freely, as the user of your module knows what she is doing. Always).
831		1103
832	=head1 WHAT TO DO IN THE MAIN PROGRAM	1104	=head1 WHAT TO DO IN THE MAIN PROGRAM
833		1105
834	There will always be a single main program - the only place that should	1106	There will always be a single main program - the only place that should
835	dictate which event model to use.	1107	dictate which event model to use.
836		1108
837	If it doesn't care, it can just "use AnyEvent" and use it itself, or not	1109	If the program is not event-based, it need not do anything special, even
838	do anything special (it does not need to be event-based) and let AnyEvent	1110	when it depends on a module that uses an AnyEvent. If the program itself
839	decide which implementation to chose if some module relies on it.	1111	uses AnyEvent, but does not care which event loop is used, all it needs
		1112	to do is C<use AnyEvent>. In either case, AnyEvent will choose the best
		1113	available loop implementation.
840		1114
841	If the main program relies on a specific event model - for example, in	1115	If the main program relies on a specific event model - for example, in
842	Gtk2 programs you have to rely on the Glib module - you should load the	1116	Gtk2 programs you have to rely on the Glib module - you should load the
843	event module before loading AnyEvent or any module that uses it: generally	1117	event module before loading AnyEvent or any module that uses it: generally
844	speaking, you should load it as early as possible. The reason is that	1118	speaking, you should load it as early as possible. The reason is that
845	modules might create watchers when they are loaded, and AnyEvent will	1119	modules might create watchers when they are loaded, and AnyEvent will
846	decide on the event model to use as soon as it creates watchers, and it	1120	decide on the event model to use as soon as it creates watchers, and it
847	might chose the wrong one unless you load the correct one yourself.	1121	might choose the wrong one unless you load the correct one yourself.
848		1122
849	You can chose to use a pure-perl implementation by loading the	1123	You can chose to use a pure-perl implementation by loading the
850	C<AnyEvent::Impl::Perl> module, which gives you similar behaviour	1124	C<AnyEvent::Loop> module, which gives you similar behaviour
851	everywhere, but letting AnyEvent chose the model is generally better.	1125	everywhere, but letting AnyEvent chose the model is generally better.
852		1126
853	=head2 MAINLOOP EMULATION	1127	=head2 MAINLOOP EMULATION
854		1128
855	Sometimes (often for short test scripts, or even standalone programs who	1129	Sometimes (often for short test scripts, or even standalone programs who
…		…
868		1142
869		1143
870	=head1 OTHER MODULES	1144	=head1 OTHER MODULES
871		1145
872	The following is a non-exhaustive list of additional modules that use	1146	The following is a non-exhaustive list of additional modules that use
873	AnyEvent as a client and can therefore be mixed easily with other AnyEvent	1147	AnyEvent as a client and can therefore be mixed easily with other
874	modules and other event loops in the same program. Some of the modules	1148	AnyEvent modules and other event loops in the same program. Some of the
875	come with AnyEvent, most are available via CPAN.	1149	modules come as part of AnyEvent, the others are available via CPAN (see
		1150	L<http://search.cpan.org/search?m=module&q=anyevent%3A%3A*> for
		1151	a longer non-exhaustive list), and the list is heavily biased towards
		1152	modules of the AnyEvent author himself :)
876		1153
877	=over 4	1154	=over 4
878		1155
879	=item L<AnyEvent::Util>	1156	=item L<AnyEvent::Util> (part of the AnyEvent distribution)
880		1157
881	Contains various utility functions that replace often-used but blocking	1158	Contains various utility functions that replace often-used blocking
882	functions such as C<inet_aton> by event-/callback-based versions.	1159	functions such as C<inet_aton> with event/callback-based versions.
883		1160
884	=item L<AnyEvent::Socket>	1161	=item L<AnyEvent::Socket> (part of the AnyEvent distribution)
885		1162
886	Provides various utility functions for (internet protocol) sockets,	1163	Provides various utility functions for (internet protocol) sockets,
887	addresses and name resolution. Also functions to create non-blocking tcp	1164	addresses and name resolution. Also functions to create non-blocking tcp
888	connections or tcp servers, with IPv6 and SRV record support and more.	1165	connections or tcp servers, with IPv6 and SRV record support and more.
889		1166
890	=item L<AnyEvent::Handle>	1167	=item L<AnyEvent::Handle> (part of the AnyEvent distribution)
891		1168
892	Provide read and write buffers, manages watchers for reads and writes,	1169	Provide read and write buffers, manages watchers for reads and writes,
893	supports raw and formatted I/O, I/O queued and fully transparent and	1170	supports raw and formatted I/O, I/O queued and fully transparent and
894	non-blocking SSL/TLS (via L<AnyEvent::TLS>.	1171	non-blocking SSL/TLS (via L<AnyEvent::TLS>).
895		1172
896	=item L<AnyEvent::DNS>	1173	=item L<AnyEvent::DNS> (part of the AnyEvent distribution)
897		1174
898	Provides rich asynchronous DNS resolver capabilities.	1175	Provides rich asynchronous DNS resolver capabilities.
899		1176
900	=item L<AnyEvent::HTTP>	1177	=item L<AnyEvent::HTTP>, L<AnyEvent::IRC>, L<AnyEvent::XMPP>, L<AnyEvent::GPSD>, L<AnyEvent::IGS>, L<AnyEvent::FCP>
901		1178
902	A simple-to-use HTTP library that is capable of making a lot of concurrent	1179	Implement event-based interfaces to the protocols of the same name (for
903	HTTP requests.	1180	the curious, IGS is the International Go Server and FCP is the Freenet
		1181	Client Protocol).
904		1182
		1183	=item L<AnyEvent::AIO> (part of the AnyEvent distribution)
		1184
		1185	Truly asynchronous (as opposed to non-blocking) I/O, should be in the
		1186	toolbox of every event programmer. AnyEvent::AIO transparently fuses
		1187	L<IO::AIO> and AnyEvent together, giving AnyEvent access to event-based
		1188	file I/O, and much more.
		1189
		1190	=item L<AnyEvent::Fork>, L<AnyEvent::Fork::RPC>, L<AnyEvent::Fork::Pool>, L<AnyEvent::Fork::Remote>
		1191
		1192	These let you safely fork new subprocesses, either locally or
		1193	remotely (e.g.v ia ssh), using some RPC protocol or not, without
		1194	the limitations normally imposed by fork (AnyEvent works fine for
		1195	example). Dynamically-resized worker pools are obviously included as well.
		1196
		1197	And they are quite tiny and fast as well - "abusing" L<AnyEvent::Fork>
		1198	just to exec external programs can easily beat using C<fork> and C<exec>
		1199	(or even C<system>) in most programs.
		1200
		1201	=item L<AnyEvent::Filesys::Notify>
		1202
		1203	AnyEvent is good for non-blocking stuff, but it can't detect file or
		1204	path changes (e.g. "watch this directory for new files", "watch this
		1205	file for changes"). The L<AnyEvent::Filesys::Notify> module promises to
		1206	do just that in a portbale fashion, supporting inotify on GNU/Linux and
		1207	some weird, without doubt broken, stuff on OS X to monitor files. It can
		1208	fall back to blocking scans at regular intervals transparently on other
		1209	platforms, so it's about as portable as it gets.
		1210
		1211	(I haven't used it myself, but it seems the biggest problem with it is
		1212	it quite bad performance).
		1213
905	=item L<AnyEvent::HTTPD>	1214	=item L<AnyEvent::DBI>
906		1215
907	Provides a simple web application server framework.	1216	Executes L<DBI> requests asynchronously in a proxy process for you,
		1217	notifying you in an event-based way when the operation is finished.
908		1218
909	=item L<AnyEvent::FastPing>	1219	=item L<AnyEvent::FastPing>
910		1220
911	The fastest ping in the west.	1221	The fastest ping in the west.
912		1222
913	=item L<AnyEvent::DBI>
914
915	Executes L<DBI> requests asynchronously in a proxy process.
916
917	=item L<AnyEvent::AIO>
918
919	Truly asynchronous I/O, should be in the toolbox of every event
920	programmer. AnyEvent::AIO transparently fuses L<IO::AIO> and AnyEvent
921	together.
922
923	=item L<AnyEvent::BDB>
924
925	Truly asynchronous Berkeley DB access. AnyEvent::BDB transparently fuses
926	L<BDB> and AnyEvent together.
927
928	=item L<AnyEvent::GPSD>
929
930	A non-blocking interface to gpsd, a daemon delivering GPS information.
931
932	=item L<AnyEvent::IRC>
933
934	AnyEvent based IRC client module family (replacing the older Net::IRC3).
935
936	=item L<AnyEvent::XMPP>
937
938	AnyEvent based XMPP (Jabber protocol) module family (replacing the older
939	Net::XMPP2>.
940
941	=item L<AnyEvent::IGS>
942
943	A non-blocking interface to the Internet Go Server protocol (used by
944	L<App::IGS>).
945
946	=item L<Net::FCP>
947
948	AnyEvent-based implementation of the Freenet Client Protocol, birthplace
949	of AnyEvent.
950
951	=item L<Event::ExecFlow>
952
953	High level API for event-based execution flow control.
954
955	=item L<Coro>	1223	=item L<Coro>
956		1224
957	Has special support for AnyEvent via L<Coro::AnyEvent>.	1225	Has special support for AnyEvent via L<Coro::AnyEvent>, which allows you
		1226	to simply invert the flow control - don't call us, we will call you:
		1227
		1228	async {
		1229	Coro::AnyEvent::sleep 5; # creates a 5s timer and waits for it
		1230	print "5 seconds later!\n";
		1231
		1232	Coro::AnyEvent::readable *STDIN; # uses an I/O watcher
		1233	my $line = <STDIN>; # works for ttys
		1234
		1235	AnyEvent::HTTP::http_get "url", Coro::rouse_cb;
		1236	my ($body, $hdr) = Coro::rouse_wait;
		1237	};
958		1238
959	=back	1239	=back
960		1240
961	=cut	1241	=cut
962		1242
963	package AnyEvent;	1243	package AnyEvent;
964		1244
965	no warnings;	1245	BEGIN {
966	use strict qw(vars subs);	1246	require "AnyEvent/constants.pl";
		1247	&AnyEvent::common_sense;
		1248	}
967		1249
968	use Carp;	1250	use Carp ();
969		1251
970	our $VERSION = 4.801;	1252	our $VERSION = '7.07';
971	our $MODEL;	1253	our $MODEL;
972
973	our $AUTOLOAD;
974	our @ISA;	1254	our @ISA;
975
976	our @REGISTRY;	1255	our @REGISTRY;
977		1256	our $VERBOSE;
978	our $WIN32;	1257	our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred
		1258	our $MAX_SIGNAL_LATENCY = $ENV{PERL_ANYEVENT_MAX_SIGNAL_LATENCY} || 10; # executes after the BEGIN block below (tainting!)
979		1259
980	BEGIN {	1260	BEGIN {
981	eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }";
982	eval "sub TAINT(){ " . (${^TAINT}*1) . " }";	1261	eval "sub TAINT (){" . (${^TAINT}*1) . "}";
983		1262
984	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}	1263	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}
985	if ${^TAINT};	1264	if ${^TAINT};
986	}
987		1265
988	our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1;	1266	$ENV{"PERL_ANYEVENT_$_"} = $ENV{"AE_$_"}
		1267	for grep s/^AE_// && !exists $ENV{"PERL_ANYEVENT_$_"}, keys %ENV;
989		1268
990	our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred	1269	@ENV{grep /^PERL_ANYEVENT_/, keys %ENV} = ()
		1270	if ${^TAINT};
991		1271
992	{	1272	# $ENV{PERL_ANYEVENT_xxx} now valid
		1273
		1274	$VERBOSE = length $ENV{PERL_ANYEVENT_VERBOSE} ? $ENV{PERL_ANYEVENT_VERBOSE}*1 : 4;
		1275
993	my $idx;	1276	my $idx;
994	$PROTOCOL{$_} = ++$idx	1277	$PROTOCOL{$_} = ++$idx
995	for reverse split /\s*,\s*/,	1278	for reverse split /\s*,\s*/,
996	$ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";	1279	$ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";
997	}	1280	}
998		1281
		1282	our @post_detect;
		1283
		1284	sub post_detect(&) {
		1285	my ($cb) = @_;
		1286
		1287	push @post_detect, $cb;
		1288
		1289	defined wantarray
		1290	? bless \$cb, "AnyEvent::Util::postdetect"
		1291	: ()
		1292	}
		1293
		1294	sub AnyEvent::Util::postdetect::DESTROY {
		1295	@post_detect = grep $_ != ${$_[0]}, @post_detect;
		1296	}
		1297
		1298	our $POSTPONE_W;
		1299	our @POSTPONE;
		1300
		1301	sub _postpone_exec {
		1302	undef $POSTPONE_W;
		1303
		1304	&{ shift @POSTPONE }
		1305	while @POSTPONE;
		1306	}
		1307
		1308	sub postpone(&) {
		1309	push @POSTPONE, shift;
		1310
		1311	$POSTPONE_W ||= AE::timer (0, 0, \&_postpone_exec);
		1312
		1313	()
		1314	}
		1315
		1316	sub log($$;@) {
		1317	# only load the big bloated module when we actually are about to log something
		1318	if ($_[0] <= ($VERBOSE || 1)) { # also catches non-numeric levels(!) and fatal
		1319	local ($!, $@);
		1320	require AnyEvent::Log; # among other things, sets $VERBOSE to 9
		1321	# AnyEvent::Log overwrites this function
		1322	goto &log;
		1323	}
		1324
		1325	0 # not logged
		1326	}
		1327
		1328	sub _logger($;$) {
		1329	my ($level, $renabled) = @_;
		1330
		1331	$$renabled = $level <= $VERBOSE;
		1332
		1333	my $logger = [(caller)[0], $level, $renabled];
		1334
		1335	$AnyEvent::Log::LOGGER{$logger+0} = $logger;
		1336
		1337	# return unless defined wantarray;
		1338	#
		1339	# require AnyEvent::Util;
		1340	# my $guard = AnyEvent::Util::guard (sub {
		1341	# # "clean up"
		1342	# delete $LOGGER{$logger+0};
		1343	# });
		1344	#
		1345	# sub {
		1346	# return 0 unless $$renabled;
		1347	#
		1348	# $guard if 0; # keep guard alive, but don't cause runtime overhead
		1349	# require AnyEvent::Log unless $AnyEvent::Log::VERSION;
		1350	# package AnyEvent::Log;
		1351	# _log ($logger->[0], $level, @_) # logger->[0] has been converted at load time
		1352	# }
		1353	}
		1354
		1355	if (length $ENV{PERL_ANYEVENT_LOG}) {
		1356	require AnyEvent::Log; # AnyEvent::Log does the thing for us
		1357	}
		1358
999	my @models = (	1359	our @models = (
1000	[EV:: => AnyEvent::Impl::EV::],	1360	[EV:: => AnyEvent::Impl::EV::],
1001	[Event:: => AnyEvent::Impl::Event::],
1002	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::],	1361	[AnyEvent::Loop:: => AnyEvent::Impl::Perl::],
1003	# everything below here will not be autoprobed	1362	# everything below here will not (normally) be autoprobed
1004	# as the pureperl backend should work everywhere	1363	# as the pure perl backend should work everywhere
1005	# and is usually faster	1364	# and is usually faster
		1365	[Irssi:: => AnyEvent::Impl::Irssi::], # Irssi has a bogus "Event" package, so msut be near the top
		1366	[Event:: => AnyEvent::Impl::Event::], # slow, stable
		1367	[Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers
		1368	# everything below here should not be autoloaded
		1369	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
1006	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles	1370	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
1007	[Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers
1008	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
1009	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program	1371	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program
1010	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza	1372	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
1011	[Wx:: => AnyEvent::Impl::POE::],	1373	[Wx:: => AnyEvent::Impl::POE::],
1012	[Prima:: => AnyEvent::Impl::POE::],	1374	[Prima:: => AnyEvent::Impl::POE::],
1013	# IO::Async is just too broken - we would need workaorunds for its	1375	[IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # a bitch to autodetect
1014	# byzantine signal and broken child handling, among others.	1376	[Cocoa::EventLoop:: => AnyEvent::Impl::Cocoa::],
1015	# IO::Async is rather hard to detect, as it doesn't have any	1377	[FLTK:: => AnyEvent::Impl::FLTK::],
1016	# obvious default class.
1017	# [IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program
1018	# [IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program
1019	# [IO::Async::Notifier:: => AnyEvent::Impl::IOAsync::], # requires special main program
1020	);	1378	);
1021		1379
1022	our %method = map +($_ => 1),	1380	our @isa_hook;
		1381
		1382	sub _isa_set {
		1383	my @pkg = ("AnyEvent", (map $_->[0], grep defined, @isa_hook), $MODEL);
		1384
		1385	@{"$pkg[$_-1]::ISA"} = $pkg[$_]
		1386	for 1 .. $#pkg;
		1387
		1388	grep $_ && $_->[1], @isa_hook
		1389	and AE::_reset ();
		1390	}
		1391
		1392	# used for hooking AnyEvent::Strict and AnyEvent::Debug::Wrap into the class hierarchy
		1393	sub _isa_hook($$;$) {
		1394	my ($i, $pkg, $reset_ae) = @_;
		1395
		1396	$isa_hook[$i] = $pkg ? [$pkg, $reset_ae] : undef;
		1397
		1398	_isa_set;
		1399	}
		1400
		1401	# all autoloaded methods reserve the complete glob, not just the method slot.
		1402	# due to bugs in perls method cache implementation.
1023	qw(io timer time now now_update signal child idle condvar one_event DESTROY);	1403	our @methods = qw(io timer time now now_update signal child idle condvar);
1024		1404
1025	our @post_detect;
1026
1027	sub post_detect(&) {	1405	sub detect() {
1028	my ($cb) = @_;	1406	return $MODEL if $MODEL; # some programs keep references to detect
1029		1407
1030	if ($MODEL) {	1408	# IO::Async::Loop::AnyEvent is extremely evil, refuse to work with it
1031	$cb->();	1409	# the author knows about the problems and what it does to AnyEvent as a whole
		1410	# (and the ability of others to use AnyEvent), but simply wants to abuse AnyEvent
		1411	# anyway.
		1412	AnyEvent::log fatal => "IO::Async::Loop::AnyEvent detected - that module is broken by\n"
		1413	. "design, abuses internals and breaks AnyEvent - will not continue."
		1414	if exists $INC{"IO/Async/Loop/AnyEvent.pm"};
1032		1415
1033	1	1416	local $!; # for good measure
		1417	local $SIG{__DIE__}; # we use eval
		1418
		1419	# free some memory
		1420	*detect = sub () { $MODEL };
		1421	# undef &func doesn't correctly update the method cache. grmbl.
		1422	# so we delete the whole glob. grmbl.
		1423	# otoh, perl doesn't let me undef an active usb, but it lets me free
		1424	# a glob with an active sub. hrm. i hope it works, but perl is
		1425	# usually buggy in this department. sigh.
		1426	delete @{"AnyEvent::"}{@methods};
		1427	undef @methods;
		1428
		1429	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z0-9:]+)$/) {
		1430	my $model = $1;
		1431	$model = "AnyEvent::Impl::$model" unless $model =~ s/::$//;
		1432	if (eval "require $model") {
		1433	AnyEvent::log 7 => "Loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.";
		1434	$MODEL = $model;
1034	} else {	1435	} else {
1035	push @post_detect, $cb;	1436	AnyEvent::log 4 => "Unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@";
1036		1437	}
1037	defined wantarray
1038	? bless \$cb, "AnyEvent::Util::postdetect"
1039	: ()
1040	}	1438	}
1041	}
1042		1439
1043	sub AnyEvent::Util::postdetect::DESTROY {	1440	# check for already loaded models
1044	@post_detect = grep $_ != ${$_[0]}, @post_detect;
1045	}
1046
1047	sub detect() {
1048	unless ($MODEL) {	1441	unless ($MODEL) {
1049	no strict 'refs';	1442	for (@REGISTRY, @models) {
1050	local $SIG{__DIE__};	1443	my ($package, $model) = @$_;
1051		1444	if (${"$package\::VERSION"} > 0) {
1052	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {
1053	my $model = "AnyEvent::Impl::$1";
1054	if (eval "require $model") {	1445	if (eval "require $model") {
		1446	AnyEvent::log 7 => "Autodetected model '$model', using it.";
1055	$MODEL = $model;	1447	$MODEL = $model;
1056	warn "AnyEvent: loaded model '$model' (forced by \$PERL_ANYEVENT_MODEL), using it.\n" if $verbose > 1;	1448	last;
1057	} else {	1449	} else {
1058	warn "AnyEvent: unable to load model '$model' (from \$PERL_ANYEVENT_MODEL):\n$@" if $verbose;	1450	AnyEvent::log 8 => "Detected event loop $package, but cannot load '$model', skipping: $@";
		1451	}
1059	}	1452	}
1060	}	1453	}
1061		1454
1062	# check for already loaded models
1063	unless ($MODEL) {	1455	unless ($MODEL) {
		1456	# try to autoload a model
1064	for (@REGISTRY, @models) {	1457	for (@REGISTRY, @models) {
1065	my ($package, $model) = @$_;	1458	my ($package, $model) = @$_;
		1459	if (
		1460	eval "require $package"
1066	if (${"$package\::VERSION"} > 0) {	1461	and ${"$package\::VERSION"} > 0
1067	if (eval "require $model") {	1462	and eval "require $model"
		1463	) {
		1464	AnyEvent::log 7 => "Autoloaded model '$model', using it.";
1068	$MODEL = $model;	1465	$MODEL = $model;
1069	warn "AnyEvent: autodetected model '$model', using it.\n" if $verbose > 1;
1070	last;	1466	last;
1071	}
1072	}	1467	}
1073	}	1468	}
1074		1469
1075	unless ($MODEL) {
1076	# try to load a model
1077
1078	for (@REGISTRY, @models) {
1079	my ($package, $model) = @$_;
1080	if (eval "require $package"
1081	and ${"$package\::VERSION"} > 0
1082	and eval "require $model") {
1083	$MODEL = $model;
1084	warn "AnyEvent: autoprobed model '$model', using it.\n" if $verbose > 1;
1085	last;
1086	}
1087	}
1088
1089	$MODEL	1470	$MODEL
1090	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.\n";	1471	or AnyEvent::log fatal => "Backend autodetection failed - did you properly install AnyEvent?";
1091	}
1092	}	1472	}
1093
1094	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
1095
1096	unshift @ISA, $MODEL;
1097
1098	require AnyEvent::Strict if $ENV{PERL_ANYEVENT_STRICT};
1099
1100	(shift @post_detect)->() while @post_detect;
1101	}	1473	}
1102		1474
		1475	# free memory only needed for probing
		1476	undef @models;
		1477	undef @REGISTRY;
		1478
		1479	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
		1480
		1481	# now nuke some methods that are overridden by the backend.
		1482	# SUPER usage is not allowed in these.
		1483	for (qw(time signal child idle)) {
		1484	undef &{"AnyEvent::Base::$_"}
		1485	if defined &{"$MODEL\::$_"};
		1486	}
		1487
		1488	_isa_set;
		1489
		1490	# we're officially open!
		1491
		1492	if ($ENV{PERL_ANYEVENT_STRICT}) {
		1493	require AnyEvent::Strict;
		1494	}
		1495
		1496	if ($ENV{PERL_ANYEVENT_DEBUG_WRAP}) {
		1497	require AnyEvent::Debug;
		1498	AnyEvent::Debug::wrap ($ENV{PERL_ANYEVENT_DEBUG_WRAP});
		1499	}
		1500
		1501	if (length $ENV{PERL_ANYEVENT_DEBUG_SHELL}) {
		1502	require AnyEvent::Socket;
		1503	require AnyEvent::Debug;
		1504
		1505	my $shell = $ENV{PERL_ANYEVENT_DEBUG_SHELL};
		1506	$shell =~ s/\$\$/$$/g;
		1507
		1508	my ($host, $service) = AnyEvent::Socket::parse_hostport ($shell);
		1509	$AnyEvent::Debug::SHELL = AnyEvent::Debug::shell ($host, $service);
		1510	}
		1511
		1512	# now the anyevent environment is set up as the user told us to, so
		1513	# call the actual user code - post detects
		1514
		1515	(shift @post_detect)->() while @post_detect;
		1516	undef @post_detect;
		1517
		1518	*post_detect = sub(&) {
		1519	shift->();
		1520
		1521	undef
		1522	};
		1523
1103	$MODEL	1524	$MODEL
1104	}	1525	}
1105		1526
1106	sub AUTOLOAD {	1527	for my $name (@methods) {
1107	(my $func = $AUTOLOAD) =~ s/.*://;	1528	*$name = sub {
1108		1529	detect;
1109	$method{$func}	1530	# we use goto because
1110	or croak "$func: not a valid method for AnyEvent objects";	1531	# a) it makes the thunk more transparent
1111		1532	# b) it allows us to delete the thunk later
1112	detect unless $MODEL;	1533	goto &{ UNIVERSAL::can AnyEvent => "SUPER::$name" }
1113		1534	};
1114	my $class = shift;
1115	$class->$func (@_);
1116	}	1535	}
1117		1536
1118	# utility function to dup a filehandle. this is used by many backends	1537	# utility function to dup a filehandle. this is used by many backends
1119	# to support binding more than one watcher per filehandle (they usually	1538	# to support binding more than one watcher per filehandle (they usually
1120	# allow only one watcher per fd, so we dup it to get a different one).	1539	# allow only one watcher per fd, so we dup it to get a different one).
1121	sub _dupfh($$;$$) {	1540	sub _dupfh($$;$$) {
1122	my ($poll, $fh, $r, $w) = @_;	1541	my ($poll, $fh, $r, $w) = @_;
1123		1542
1124	# cygwin requires the fh mode to be matching, unix doesn't	1543	# cygwin requires the fh mode to be matching, unix doesn't
1125	my ($rw, $mode) = $poll eq "r" ? ($r, "<") : ($w, ">");	1544	my ($rw, $mode) = $poll eq "r" ? ($r, "<&") : ($w, ">&");
1126		1545
1127	open my $fh2, "$mode&", $fh	1546	open my $fh2, $mode, $fh
1128	or die "AnyEvent->io: cannot dup() filehandle in mode '$poll': $!,";	1547	or die "AnyEvent->io: cannot dup() filehandle in mode '$poll': $!,";
1129		1548
1130	# we assume CLOEXEC is already set by perl in all important cases	1549	# we assume CLOEXEC is already set by perl in all important cases
1131		1550
1132	($fh2, $rw)	1551	($fh2, $rw)
1133	}	1552	}
1134		1553
		1554	=head1 SIMPLIFIED AE API
		1555
		1556	Starting with version 5.0, AnyEvent officially supports a second, much
		1557	simpler, API that is designed to reduce the calling, typing and memory
		1558	overhead by using function call syntax and a fixed number of parameters.
		1559
		1560	See the L<AE> manpage for details.
		1561
		1562	=cut
		1563
		1564	package AE;
		1565
		1566	our $VERSION = $AnyEvent::VERSION;
		1567
		1568	sub _reset() {
		1569	eval q{
		1570	# fall back to the main API by default - backends and AnyEvent::Base
		1571	# implementations can overwrite these.
		1572
		1573	sub io($$$) {
		1574	AnyEvent->io (fh => $_[0], poll => $_[1] ? "w" : "r", cb => $_[2])
		1575	}
		1576
		1577	sub timer($$$) {
		1578	AnyEvent->timer (after => $_[0], interval => $_[1], cb => $_[2])
		1579	}
		1580
		1581	sub signal($$) {
		1582	AnyEvent->signal (signal => $_[0], cb => $_[1])
		1583	}
		1584
		1585	sub child($$) {
		1586	AnyEvent->child (pid => $_[0], cb => $_[1])
		1587	}
		1588
		1589	sub idle($) {
		1590	AnyEvent->idle (cb => $_[0]);
		1591	}
		1592
		1593	sub cv(;&) {
		1594	AnyEvent->condvar (@_ ? (cb => $_[0]) : ())
		1595	}
		1596
		1597	sub now() {
		1598	AnyEvent->now
		1599	}
		1600
		1601	sub now_update() {
		1602	AnyEvent->now_update
		1603	}
		1604
		1605	sub time() {
		1606	AnyEvent->time
		1607	}
		1608
		1609	*postpone = \&AnyEvent::postpone;
		1610	*log = \&AnyEvent::log;
		1611	};
		1612	die if $@;
		1613	}
		1614
		1615	BEGIN { _reset }
		1616
1135	package AnyEvent::Base;	1617	package AnyEvent::Base;
1136		1618
1137	# default implementations for many methods	1619	# default implementations for many methods
1138		1620
1139	BEGIN {	1621	sub time {
		1622	eval q{ # poor man's autoloading {}
		1623	# probe for availability of Time::HiRes
1140	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {	1624	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {
		1625	*time = sub { Time::HiRes::time () };
1141	*_time = \&Time::HiRes::time;	1626	*AE::time = \& Time::HiRes::time ;
		1627	*now = \&time;
		1628	AnyEvent::log 8 => "using Time::HiRes for sub-second timing accuracy.";
1142	# if (eval "use POSIX (); (POSIX::times())...	1629	# if (eval "use POSIX (); (POSIX::times())...
1143	} else {	1630	} else {
1144	*_time = sub { time }; # epic fail	1631	*time = sub { CORE::time };
		1632	*AE::time = sub (){ CORE::time };
		1633	*now = \&time;
		1634	AnyEvent::log 3 => "Using built-in time(), no sub-second resolution!";
		1635	}
		1636	};
		1637	die if $@;
		1638
		1639	&time
		1640	}
		1641
		1642	*now = \&time;
		1643	sub now_update { }
		1644
		1645	sub _poll {
		1646	Carp::croak "$AnyEvent::MODEL does not support blocking waits. Caught";
		1647	}
		1648
		1649	# default implementation for ->condvar
		1650	# in fact, the default should not be overwritten
		1651
		1652	sub condvar {
		1653	eval q{ # poor man's autoloading {}
		1654	*condvar = sub {
		1655	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"
		1656	};
		1657
		1658	*AE::cv = sub (;&) {
		1659	bless { @_ ? (_ae_cb => shift) : () }, "AnyEvent::CondVar"
		1660	};
		1661	};
		1662	die if $@;
		1663
		1664	&condvar
		1665	}
		1666
		1667	# default implementation for ->signal
		1668
		1669	our $HAVE_ASYNC_INTERRUPT;
		1670
		1671	sub _have_async_interrupt() {
		1672	$HAVE_ASYNC_INTERRUPT = 1*(!$ENV{PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT}
		1673	&& eval "use Async::Interrupt 1.02 (); 1")
		1674	unless defined $HAVE_ASYNC_INTERRUPT;
		1675
		1676	$HAVE_ASYNC_INTERRUPT
		1677	}
		1678
		1679	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);
		1680	our (%SIG_ASY, %SIG_ASY_W);
		1681	our ($SIG_COUNT, $SIG_TW);
		1682
		1683	# install a dummy wakeup watcher to reduce signal catching latency
		1684	# used by Impls
		1685	sub _sig_add() {
		1686	unless ($SIG_COUNT++) {
		1687	# try to align timer on a full-second boundary, if possible
		1688	my $NOW = AE::now;
		1689
		1690	$SIG_TW = AE::timer
		1691	$MAX_SIGNAL_LATENCY - ($NOW - int $NOW),
		1692	$MAX_SIGNAL_LATENCY,
		1693	sub { } # just for the PERL_ASYNC_CHECK
		1694	;
1145	}	1695	}
1146	}	1696	}
1147		1697
1148	sub time { _time }	1698	sub _sig_del {
1149	sub now { _time }	1699	undef $SIG_TW
1150	sub now_update { }	1700	unless --$SIG_COUNT;
1151
1152	# default implementation for ->condvar
1153
1154	sub condvar {
1155	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"
1156	}	1701	}
1157		1702
1158	# default implementation for ->signal	1703	our $_sig_name_init; $_sig_name_init = sub {
		1704	eval q{ # poor man's autoloading {}
		1705	undef $_sig_name_init;
1159		1706
1160	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);	1707	if (_have_async_interrupt) {
		1708	*sig2num = \&Async::Interrupt::sig2num;
		1709	*sig2name = \&Async::Interrupt::sig2name;
		1710	} else {
		1711	require Config;
1161		1712
1162	sub _signal_exec {	1713	my %signame2num;
1163	sysread $SIGPIPE_R, my $dummy, 4;	1714	@signame2num{ split ' ', $Config::Config{sig_name} }
		1715	= split ' ', $Config::Config{sig_num};
1164		1716
1165	while (%SIG_EV) {	1717	my @signum2name;
1166	for (keys %SIG_EV) {	1718	@signum2name[values %signame2num] = keys %signame2num;
1167	delete $SIG_EV{$_};	1719
1168	$_->() for values %{ $SIG_CB{$_} || {} };	1720	*sig2num = sub($) {
		1721	$_[0] > 0 ? shift : $signame2num{+shift}
		1722	};
		1723	*sig2name = sub ($) {
		1724	$_[0] > 0 ? $signum2name[+shift] : shift
		1725	};
1169	}	1726	}
1170	}	1727	};
1171	}	1728	die if $@;
		1729	};
		1730
		1731	sub sig2num ($) { &$_sig_name_init; &sig2num }
		1732	sub sig2name($) { &$_sig_name_init; &sig2name }
1172		1733
1173	sub signal {	1734	sub signal {
1174	my (undef, %arg) = @_;	1735	eval q{ # poor man's autoloading {}
		1736	# probe for availability of Async::Interrupt
		1737	if (_have_async_interrupt) {
		1738	AnyEvent::log 8 => "Using Async::Interrupt for race-free signal handling.";
1175		1739
1176	unless ($SIGPIPE_R) {	1740	$SIGPIPE_R = new Async::Interrupt::EventPipe;
1177	require Fcntl;	1741	$SIG_IO = AE::io $SIGPIPE_R->fileno, 0, \&_signal_exec;
1178		1742
1179	if (AnyEvent::WIN32) {
1180	require AnyEvent::Util;
1181
1182	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
1183	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R) if $SIGPIPE_R;
1184	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W) if $SIGPIPE_W; # just in case
1185	} else {	1743	} else {
		1744	AnyEvent::log 8 => "Using emulated perl signal handling with latency timer.";
		1745
		1746	if (AnyEvent::WIN32) {
		1747	require AnyEvent::Util;
		1748
		1749	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
		1750	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R, 1) if $SIGPIPE_R;
		1751	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W, 1) if $SIGPIPE_W; # just in case
		1752	} else {
1186	pipe $SIGPIPE_R, $SIGPIPE_W;	1753	pipe $SIGPIPE_R, $SIGPIPE_W;
1187	fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R;	1754	fcntl $SIGPIPE_R, AnyEvent::F_SETFL, AnyEvent::O_NONBLOCK if $SIGPIPE_R;
1188	fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case	1755	fcntl $SIGPIPE_W, AnyEvent::F_SETFL, AnyEvent::O_NONBLOCK if $SIGPIPE_W; # just in case
1189		1756
1190	# not strictly required, as $^F is normally 2, but let's make sure...	1757	# not strictly required, as $^F is normally 2, but let's make sure...
1191	fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;	1758	fcntl $SIGPIPE_R, AnyEvent::F_SETFD, AnyEvent::FD_CLOEXEC;
1192	fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;	1759	fcntl $SIGPIPE_W, AnyEvent::F_SETFD, AnyEvent::FD_CLOEXEC;
		1760	}
		1761
		1762	$SIGPIPE_R
		1763	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";
		1764
		1765	$SIG_IO = AE::io $SIGPIPE_R, 0, \&_signal_exec;
1193	}	1766	}
1194		1767
1195	$SIGPIPE_R	1768	*signal = $HAVE_ASYNC_INTERRUPT
1196	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";	1769	? sub {
		1770	my (undef, %arg) = @_;
1197		1771
1198	$SIG_IO = AnyEvent->io (fh => $SIGPIPE_R, poll => "r", cb => \&_signal_exec);	1772	# async::interrupt
1199	}
1200
1201	my $signal = uc $arg{signal}	1773	my $signal = sig2num $arg{signal};
1202	or Carp::croak "required option 'signal' is missing";
1203
1204	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};	1774	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
		1775
		1776	$SIG_ASY{$signal} ||= new Async::Interrupt
		1777	cb => sub { undef $SIG_EV{$signal} },
		1778	signal => $signal,
		1779	pipe => [$SIGPIPE_R->filenos],
		1780	pipe_autodrain => 0,
		1781	;
		1782
		1783	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
		1784	}
		1785	: sub {
		1786	my (undef, %arg) = @_;
		1787
		1788	# pure perl
		1789	my $signal = sig2name $arg{signal};
		1790	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
		1791
1205	$SIG{$signal} ||= sub {	1792	$SIG{$signal} ||= sub {
1206	local $!;	1793	local $!;
1207	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;	1794	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;
1208	undef $SIG_EV{$signal};	1795	undef $SIG_EV{$signal};
		1796	};
		1797
		1798	# can't do signal processing without introducing races in pure perl,
		1799	# so limit the signal latency.
		1800	_sig_add;
		1801
		1802	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
		1803	}
		1804	;
		1805
		1806	*AnyEvent::Base::signal::DESTROY = sub {
		1807	my ($signal, $cb) = @{$_[0]};
		1808
		1809	_sig_del;
		1810
		1811	delete $SIG_CB{$signal}{$cb};
		1812
		1813	$HAVE_ASYNC_INTERRUPT
		1814	? delete $SIG_ASY{$signal}
		1815	: # delete doesn't work with older perls - they then
		1816	# print weird messages, or just unconditionally exit
		1817	# instead of getting the default action.
		1818	undef $SIG{$signal}
		1819	unless keys %{ $SIG_CB{$signal} };
		1820	};
		1821
		1822	*_signal_exec = sub {
		1823	$HAVE_ASYNC_INTERRUPT
		1824	? $SIGPIPE_R->drain
		1825	: sysread $SIGPIPE_R, (my $dummy), 9;
		1826
		1827	while (%SIG_EV) {
		1828	for (keys %SIG_EV) {
		1829	delete $SIG_EV{$_};
		1830	&$_ for values %{ $SIG_CB{$_} || {} };
		1831	}
		1832	}
		1833	};
1209	};	1834	};
		1835	die if $@;
1210		1836
1211	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"	1837	&signal
1212	}
1213
1214	sub AnyEvent::Base::signal::DESTROY {
1215	my ($signal, $cb) = @{$_[0]};
1216
1217	delete $SIG_CB{$signal}{$cb};
1218
1219	# delete doesn't work with older perls - they then
1220	# print weird messages, or just unconditionally exit
1221	# instead of getting the default action.
1222	undef $SIG{$signal} unless keys %{ $SIG_CB{$signal} };
1223	}	1838	}
1224		1839
1225	# default implementation for ->child	1840	# default implementation for ->child
1226		1841
1227	our %PID_CB;	1842	our %PID_CB;
1228	our $CHLD_W;	1843	our $CHLD_W;
1229	our $CHLD_DELAY_W;	1844	our $CHLD_DELAY_W;
1230	our $WNOHANG;
1231		1845
1232	sub _sigchld {	1846	# used by many Impl's
1233	while (0 < (my $pid = waitpid -1, $WNOHANG)) {	1847	sub _emit_childstatus($$) {
		1848	my (undef, $rpid, $rstatus) = @_;
		1849
		1850	$_->($rpid, $rstatus)
1234	$_->($pid, $?) for (values %{ $PID_CB{$pid} || {} }),	1851	for values %{ $PID_CB{$rpid} || {} },
1235	(values %{ $PID_CB{0} || {} });	1852	values %{ $PID_CB{0} || {} };
1236	}
1237	}	1853	}
1238		1854
1239	sub child {	1855	sub child {
		1856	eval q{ # poor man's autoloading {}
		1857	*_sigchld = sub {
		1858	my $pid;
		1859
		1860	AnyEvent->_emit_childstatus ($pid, $?)
		1861	while ($pid = waitpid -1, WNOHANG) > 0;
		1862	};
		1863
		1864	*child = sub {
1240	my (undef, %arg) = @_;	1865	my (undef, %arg) = @_;
1241		1866
1242	defined (my $pid = $arg{pid} + 0)	1867	my $pid = $arg{pid};
1243	or Carp::croak "required option 'pid' is missing";	1868	my $cb = $arg{cb};
1244		1869
1245	$PID_CB{$pid}{$arg{cb}} = $arg{cb};	1870	$PID_CB{$pid}{$cb+0} = $cb;
1246		1871
1247	$WNOHANG ||= eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1;
1248
1249	unless ($CHLD_W) {	1872	unless ($CHLD_W) {
1250	$CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld);	1873	$CHLD_W = AE::signal CHLD => \&_sigchld;
1251	# child could be a zombie already, so make at least one round	1874	# child could be a zombie already, so make at least one round
1252	&_sigchld;	1875	&_sigchld;
1253	}	1876	}
1254		1877
1255	bless [$pid, $arg{cb}], "AnyEvent::Base::child"	1878	bless [$pid, $cb+0], "AnyEvent::Base::child"
1256	}	1879	};
1257		1880
1258	sub AnyEvent::Base::child::DESTROY {	1881	*AnyEvent::Base::child::DESTROY = sub {
1259	my ($pid, $cb) = @{$_[0]};	1882	my ($pid, $icb) = @{$_[0]};
1260		1883
1261	delete $PID_CB{$pid}{$cb};	1884	delete $PID_CB{$pid}{$icb};
1262	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };	1885	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };
1263		1886
1264	undef $CHLD_W unless keys %PID_CB;	1887	undef $CHLD_W unless keys %PID_CB;
		1888	};
		1889	};
		1890	die if $@;
		1891
		1892	&child
1265	}	1893	}
1266		1894
1267	# idle emulation is done by simply using a timer, regardless	1895	# idle emulation is done by simply using a timer, regardless
1268	# of whether the process is idle or not, and not letting	1896	# of whether the process is idle or not, and not letting
1269	# the callback use more than 50% of the time.	1897	# the callback use more than 50% of the time.
1270	sub idle {	1898	sub idle {
		1899	eval q{ # poor man's autoloading {}
		1900	*idle = sub {
1271	my (undef, %arg) = @_;	1901	my (undef, %arg) = @_;
1272		1902
1273	my ($cb, $w, $rcb) = $arg{cb};	1903	my ($cb, $w, $rcb) = $arg{cb};
1274		1904
1275	$rcb = sub {	1905	$rcb = sub {
1276	if ($cb) {	1906	if ($cb) {
1277	$w = _time;	1907	$w = AE::time;
1278	&$cb;	1908	&$cb;
1279	$w = _time - $w;	1909	$w = AE::time - $w;
1280		1910
1281	# never use more then 50% of the time for the idle watcher,	1911	# never use more then 50% of the time for the idle watcher,
1282	# within some limits	1912	# within some limits
1283	$w = 0.0001 if $w < 0.0001;	1913	$w = 0.0001 if $w < 0.0001;
1284	$w = 5 if $w > 5;	1914	$w = 5 if $w > 5;
1285		1915
1286	$w = AnyEvent->timer (after => $w, cb => $rcb);	1916	$w = AE::timer $w, 0, $rcb;
1287	} else {	1917	} else {
1288	# clean up...	1918	# clean up...
1289	undef $w;	1919	undef $w;
1290	undef $rcb;	1920	undef $rcb;
		1921	}
		1922	};
		1923
		1924	$w = AE::timer 0.05, 0, $rcb;
		1925
		1926	bless \\$cb, "AnyEvent::Base::idle"
1291	}	1927	};
		1928
		1929	*AnyEvent::Base::idle::DESTROY = sub {
		1930	undef $${$_[0]};
		1931	};
1292	};	1932	};
		1933	die if $@;
1293		1934
1294	$w = AnyEvent->timer (after => 0.05, cb => $rcb);	1935	&idle
1295
1296	bless \\$cb, "AnyEvent::Base::idle"
1297	}
1298
1299	sub AnyEvent::Base::idle::DESTROY {
1300	undef $${$_[0]};
1301	}	1936	}
1302		1937
1303	package AnyEvent::CondVar;	1938	package AnyEvent::CondVar;
1304		1939
1305	our @ISA = AnyEvent::CondVar::Base::;	1940	our @ISA = AnyEvent::CondVar::Base::;
1306		1941
		1942	# only to be used for subclassing
		1943	sub new {
		1944	my $class = shift;
		1945	bless AnyEvent->condvar (@_), $class
		1946	}
		1947
1307	package AnyEvent::CondVar::Base;	1948	package AnyEvent::CondVar::Base;
1308		1949
1309	use overload	1950	#use overload
1310	'&{}' => sub { my $self = shift; sub { $self->send (@_) } },	1951	# '&{}' => sub { my $self = shift; sub { $self->send (@_) } },
1311	fallback => 1;	1952	# fallback => 1;
		1953
		1954	# save 300+ kilobytes by dirtily hardcoding overloading
		1955	${"AnyEvent::CondVar::Base::OVERLOAD"}{dummy}++; # Register with magic by touching.
		1956	*{'AnyEvent::CondVar::Base::()'} = sub { }; # "Make it findable via fetchmethod."
		1957	*{'AnyEvent::CondVar::Base::(&{}'} = sub { my $self = shift; sub { $self->send (@_) } }; # &{}
		1958	${'AnyEvent::CondVar::Base::()'} = 1; # fallback
		1959
		1960	our $WAITING;
1312		1961
1313	sub _send {	1962	sub _send {
1314	# nop	1963	# nop
		1964	}
		1965
		1966	sub _wait {
		1967	AnyEvent->_poll until $_[0]{_ae_sent};
1315	}	1968	}
1316		1969
1317	sub send {	1970	sub send {
1318	my $cv = shift;	1971	my $cv = shift;
1319	$cv->{_ae_sent} = [@_];	1972	$cv->{_ae_sent} = [@_];
…		…
1328		1981
1329	sub ready {	1982	sub ready {
1330	$_[0]{_ae_sent}	1983	$_[0]{_ae_sent}
1331	}	1984	}
1332		1985
1333	sub _wait {
1334	AnyEvent->one_event while !$_[0]{_ae_sent};
1335	}
1336
1337	sub recv {	1986	sub recv {
		1987	unless ($_[0]{_ae_sent}) {
		1988	$WAITING
		1989	and Carp::croak "AnyEvent::CondVar: recursive blocking wait attempted";
		1990
		1991	local $WAITING = 1;
1338	$_[0]->_wait;	1992	$_[0]->_wait;
		1993	}
1339		1994
1340	Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak};	1995	$_[0]{_ae_croak}
1341	wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0]	1996	and Carp::croak $_[0]{_ae_croak};
		1997
		1998	wantarray
		1999	? @{ $_[0]{_ae_sent} }
		2000	: $_[0]{_ae_sent}[0]
1342	}	2001	}
1343		2002
1344	sub cb {	2003	sub cb {
1345	$_[0]{_ae_cb} = $_[1] if @_ > 1;	2004	my $cv = shift;
		2005
		2006	@_
		2007	and $cv->{_ae_cb} = shift
		2008	and $cv->{_ae_sent}
		2009	and (delete $cv->{_ae_cb})->($cv);
		2010
1346	$_[0]{_ae_cb}	2011	$cv->{_ae_cb}
1347	}	2012	}
1348		2013
1349	sub begin {	2014	sub begin {
1350	++$_[0]{_ae_counter};	2015	++$_[0]{_ae_counter};
1351	$_[0]{_ae_end_cb} = $_[1] if @_ > 1;	2016	$_[0]{_ae_end_cb} = $_[1] if @_ > 1;
…		…
1356	&{ $_[0]{_ae_end_cb} || sub { $_[0]->send } };	2021	&{ $_[0]{_ae_end_cb} || sub { $_[0]->send } };
1357	}	2022	}
1358		2023
1359	# undocumented/compatibility with pre-3.4	2024	# undocumented/compatibility with pre-3.4
1360	*broadcast = \&send;	2025	*broadcast = \&send;
1361	*wait = \&_wait;	2026	*wait = \&recv;
1362		2027
1363	=head1 ERROR AND EXCEPTION HANDLING	2028	=head1 ERROR AND EXCEPTION HANDLING
1364		2029
1365	In general, AnyEvent does not do any error handling - it relies on the	2030	In general, AnyEvent does not do any error handling - it relies on the
1366	caller to do that if required. The L<AnyEvent::Strict> module (see also	2031	caller to do that if required. The L<AnyEvent::Strict> module (see also
…		…
1378	$Event/EV::DIED->() >>, L<Glib> uses C<< install_exception_handler >> and	2043	$Event/EV::DIED->() >>, L<Glib> uses C<< install_exception_handler >> and
1379	so on.	2044	so on.
1380		2045
1381	=head1 ENVIRONMENT VARIABLES	2046	=head1 ENVIRONMENT VARIABLES
1382		2047
1383	The following environment variables are used by this module or its	2048	AnyEvent supports a number of environment variables that tune the
1384	submodules.	2049	runtime behaviour. They are usually evaluated when AnyEvent is
		2050	loaded, initialised, or a submodule that uses them is loaded. Many of
		2051	them also cause AnyEvent to load additional modules - for example,
		2052	C<PERL_ANYEVENT_DEBUG_WRAP> causes the L<AnyEvent::Debug> module to be
		2053	loaded.
1385		2054
1386	Note that AnyEvent will remove I<all> environment variables starting with	2055	All the environment variables documented here start with
1387	C<PERL_ANYEVENT_> from C<%ENV> when it is loaded while taint mode is	2056	C<PERL_ANYEVENT_>, which is what AnyEvent considers its own
1388	enabled.	2057	namespace. Other modules are encouraged (but by no means required) to use
		2058	C<PERL_ANYEVENT_SUBMODULE> if they have registered the AnyEvent::Submodule
		2059	namespace on CPAN, for any submodule. For example, L<AnyEvent::HTTP> could
		2060	be expected to use C<PERL_ANYEVENT_HTTP_PROXY> (it should not access env
		2061	variables starting with C<AE_>, see below).
		2062
		2063	All variables can also be set via the C<AE_> prefix, that is, instead
		2064	of setting C<PERL_ANYEVENT_VERBOSE> you can also set C<AE_VERBOSE>. In
		2065	case there is a clash btween anyevent and another program that uses
		2066	C<AE_something> you can set the corresponding C<PERL_ANYEVENT_something>
		2067	variable to the empty string, as those variables take precedence.
		2068
		2069	When AnyEvent is first loaded, it copies all C<AE_xxx> env variables
		2070	to their C<PERL_ANYEVENT_xxx> counterpart unless that variable already
		2071	exists. If taint mode is on, then AnyEvent will remove I<all> environment
		2072	variables starting with C<PERL_ANYEVENT_> from C<%ENV> (or replace them
		2073	with C<undef> or the empty string, if the corresaponding C<AE_> variable
		2074	is set).
		2075
		2076	The exact algorithm is currently:
		2077
		2078	1. if taint mode enabled, delete all PERL_ANYEVENT_xyz variables from %ENV
		2079	2. copy over AE_xyz to PERL_ANYEVENT_xyz unless the latter alraedy exists
		2080	3. if taint mode enabled, set all PERL_ANYEVENT_xyz variables to undef.
		2081
		2082	This ensures that child processes will not see the C<AE_> variables.
		2083
		2084	The following environment variables are currently known to AnyEvent:
1389		2085
1390	=over 4	2086	=over 4
1391		2087
1392	=item C<PERL_ANYEVENT_VERBOSE>	2088	=item C<PERL_ANYEVENT_VERBOSE>
1393		2089
1394	By default, AnyEvent will be completely silent except in fatal	2090	By default, AnyEvent will log messages with loglevel C<4> (C<error>) or
1395	conditions. You can set this environment variable to make AnyEvent more	2091	higher (see L<AnyEvent::Log>). You can set this environment variable to a
1396	talkative.	2092	numerical loglevel to make AnyEvent more (or less) talkative.
1397		2093
		2094	If you want to do more than just set the global logging level
		2095	you should have a look at C<PERL_ANYEVENT_LOG>, which allows much more
		2096	complex specifications.
		2097
		2098	When set to C<0> (C<off>), then no messages whatsoever will be logged with
		2099	everything else at defaults.
		2100
1398	When set to C<1> or higher, causes AnyEvent to warn about unexpected	2101	When set to C<5> or higher (C<warn>), AnyEvent warns about unexpected
1399	conditions, such as not being able to load the event model specified by	2102	conditions, such as not being able to load the event model specified by
1400	C<PERL_ANYEVENT_MODEL>.	2103	C<PERL_ANYEVENT_MODEL>, or a guard callback throwing an exception - this
		2104	is the minimum recommended level for use during development.
1401		2105
1402	When set to C<2> or higher, cause AnyEvent to report to STDERR which event	2106	When set to C<7> or higher (info), AnyEvent reports which event model it
1403	model it chooses.	2107	chooses.
		2108
		2109	When set to C<8> or higher (debug), then AnyEvent will report extra
		2110	information on which optional modules it loads and how it implements
		2111	certain features.
		2112
		2113	=item C<PERL_ANYEVENT_LOG>
		2114
		2115	Accepts rather complex logging specifications. For example, you could log
		2116	all C<debug> messages of some module to stderr, warnings and above to
		2117	stderr, and errors and above to syslog, with:
		2118
		2119	PERL_ANYEVENT_LOG=Some::Module=debug,+log:filter=warn,+%syslog:%syslog=error,syslog
		2120
		2121	For the rather extensive details, see L<AnyEvent::Log>.
		2122
		2123	This variable is evaluated when AnyEvent (or L<AnyEvent::Log>) is loaded,
		2124	so will take effect even before AnyEvent has initialised itself.
		2125
		2126	Note that specifying this environment variable causes the L<AnyEvent::Log>
		2127	module to be loaded, while C<PERL_ANYEVENT_VERBOSE> does not, so only
		2128	using the latter saves a few hundred kB of memory unless a module
		2129	explicitly needs the extra features of AnyEvent::Log.
1404		2130
1405	=item C<PERL_ANYEVENT_STRICT>	2131	=item C<PERL_ANYEVENT_STRICT>
1406		2132
1407	AnyEvent does not do much argument checking by default, as thorough	2133	AnyEvent does not do much argument checking by default, as thorough
1408	argument checking is very costly. Setting this variable to a true value	2134	argument checking is very costly. Setting this variable to a true value
…		…
1410	check the arguments passed to most method calls. If it finds any problems,	2136	check the arguments passed to most method calls. If it finds any problems,
1411	it will croak.	2137	it will croak.
1412		2138
1413	In other words, enables "strict" mode.	2139	In other words, enables "strict" mode.
1414		2140
1415	Unlike C<use strict>, it is definitely recommended to keep it off in	2141	Unlike C<use strict> (or its modern cousin, C<< use L<common::sense>
1416	production. Keeping C<PERL_ANYEVENT_STRICT=1> in your environment while	2142	>>, it is definitely recommended to keep it off in production. Keeping
1417	developing programs can be very useful, however.	2143	C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs
		2144	can be very useful, however.
		2145
		2146	=item C<PERL_ANYEVENT_DEBUG_SHELL>
		2147
		2148	If this env variable is nonempty, then its contents will be interpreted by
		2149	C<AnyEvent::Socket::parse_hostport> and C<AnyEvent::Debug::shell> (after
		2150	replacing every occurance of C<$$> by the process pid). The shell object
		2151	is saved in C<$AnyEvent::Debug::SHELL>.
		2152
		2153	This happens when the first watcher is created.
		2154
		2155	For example, to bind a debug shell on a unix domain socket in
		2156	F<< /tmp/debug<pid>.sock >>, you could use this:
		2157
		2158	PERL_ANYEVENT_DEBUG_SHELL=/tmp/debug\$\$.sock perlprog
		2159	# connect with e.g.: socat readline /tmp/debug123.sock
		2160
		2161	Or to bind to tcp port 4545 on localhost:
		2162
		2163	PERL_ANYEVENT_DEBUG_SHELL=127.0.0.1:4545 perlprog
		2164	# connect with e.g.: telnet localhost 4545
		2165
		2166	Note that creating sockets in F</tmp> or on localhost is very unsafe on
		2167	multiuser systems.
		2168
		2169	=item C<PERL_ANYEVENT_DEBUG_WRAP>
		2170
		2171	Can be set to C<0>, C<1> or C<2> and enables wrapping of all watchers for
		2172	debugging purposes. See C<AnyEvent::Debug::wrap> for details.
1418		2173
1419	=item C<PERL_ANYEVENT_MODEL>	2174	=item C<PERL_ANYEVENT_MODEL>
1420		2175
1421	This can be used to specify the event model to be used by AnyEvent, before	2176	This can be used to specify the event model to be used by AnyEvent, before
1422	auto detection and -probing kicks in. It must be a string consisting	2177	auto detection and -probing kicks in.
1423	entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended	2178
		2179	It normally is a string consisting entirely of ASCII letters (e.g. C<EV>
		2180	or C<IOAsync>). The string C<AnyEvent::Impl::> gets prepended and the
1424	and the resulting module name is loaded and if the load was successful,	2181	resulting module name is loaded and - if the load was successful - used as
1425	used as event model. If it fails to load AnyEvent will proceed with	2182	event model backend. If it fails to load then AnyEvent will proceed with
1426	auto detection and -probing.	2183	auto detection and -probing.
1427		2184
1428	This functionality might change in future versions.	2185	If the string ends with C<::> instead (e.g. C<AnyEvent::Impl::EV::>) then
		2186	nothing gets prepended and the module name is used as-is (hint: C<::> at
		2187	the end of a string designates a module name and quotes it appropriately).
1429		2188
1430	For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you	2189	For example, to force the pure perl model (L<AnyEvent::Loop::Perl>) you
1431	could start your program like this:	2190	could start your program like this:
1432		2191
1433	PERL_ANYEVENT_MODEL=Perl perl ...	2192	PERL_ANYEVENT_MODEL=Perl perl ...
		2193
		2194	=item C<PERL_ANYEVENT_IO_MODEL>
		2195
		2196	The current file I/O model - see L<AnyEvent::IO> for more info.
		2197
		2198	At the moment, only C<Perl> (small, pure-perl, synchronous) and
		2199	C<IOAIO> (truly asynchronous) are supported. The default is C<IOAIO> if
		2200	L<AnyEvent::AIO> can be loaded, otherwise it is C<Perl>.
1434		2201
1435	=item C<PERL_ANYEVENT_PROTOCOLS>	2202	=item C<PERL_ANYEVENT_PROTOCOLS>
1436		2203
1437	Used by both L<AnyEvent::DNS> and L<AnyEvent::Socket> to determine preferences	2204	Used by both L<AnyEvent::DNS> and L<AnyEvent::Socket> to determine preferences
1438	for IPv4 or IPv6. The default is unspecified (and might change, or be the result	2205	for IPv4 or IPv6. The default is unspecified (and might change, or be the result
…		…
1443	used, and preference will be given to protocols mentioned earlier in the	2210	used, and preference will be given to protocols mentioned earlier in the
1444	list.	2211	list.
1445		2212
1446	This variable can effectively be used for denial-of-service attacks	2213	This variable can effectively be used for denial-of-service attacks
1447	against local programs (e.g. when setuid), although the impact is likely	2214	against local programs (e.g. when setuid), although the impact is likely
1448	small, as the program has to handle conenction and other failures anyways.	2215	small, as the program has to handle connection and other failures anyways.
1449		2216
1450	Examples: C<PERL_ANYEVENT_PROTOCOLS=ipv4,ipv6> - prefer IPv4 over IPv6,	2217	Examples: C<PERL_ANYEVENT_PROTOCOLS=ipv4,ipv6> - prefer IPv4 over IPv6,
1451	but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4>	2218	but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4>
1452	- only support IPv4, never try to resolve or contact IPv6	2219	- only support IPv4, never try to resolve or contact IPv6
1453	addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or	2220	addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or
1454	IPv6, but prefer IPv6 over IPv4.	2221	IPv6, but prefer IPv6 over IPv4.
1455		2222
		2223	=item C<PERL_ANYEVENT_HOSTS>
		2224
		2225	This variable, if specified, overrides the F</etc/hosts> file used by
		2226	L<AnyEvent::Socket>C<::resolve_sockaddr>, i.e. hosts aliases will be read
		2227	from that file instead.
		2228
1456	=item C<PERL_ANYEVENT_EDNS0>	2229	=item C<PERL_ANYEVENT_EDNS0>
1457		2230
1458	Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension	2231	Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension for
1459	for DNS. This extension is generally useful to reduce DNS traffic, but	2232	DNS. This extension is generally useful to reduce DNS traffic, especially
1460	some (broken) firewalls drop such DNS packets, which is why it is off by	2233	when DNSSEC is involved, but some (broken) firewalls drop such DNS
1461	default.	2234	packets, which is why it is off by default.
1462		2235
1463	Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce	2236	Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce
1464	EDNS0 in its DNS requests.	2237	EDNS0 in its DNS requests.
1465		2238
1466	=item C<PERL_ANYEVENT_MAX_FORKS>	2239	=item C<PERL_ANYEVENT_MAX_FORKS>
…		…
1472		2245
1473	The default value for the C<max_outstanding> parameter for the default DNS	2246	The default value for the C<max_outstanding> parameter for the default DNS
1474	resolver - this is the maximum number of parallel DNS requests that are	2247	resolver - this is the maximum number of parallel DNS requests that are
1475	sent to the DNS server.	2248	sent to the DNS server.
1476		2249
		2250	=item C<PERL_ANYEVENT_MAX_SIGNAL_LATENCY>
		2251
		2252	Perl has inherently racy signal handling (you can basically choose between
		2253	losing signals and memory corruption) - pure perl event loops (including
		2254	C<AnyEvent::Loop>, when C<Async::Interrupt> isn't available) therefore
		2255	have to poll regularly to avoid losing signals.
		2256
		2257	Some event loops are racy, but don't poll regularly, and some event loops
		2258	are written in C but are still racy. For those event loops, AnyEvent
		2259	installs a timer that regularly wakes up the event loop.
		2260
		2261	By default, the interval for this timer is C<10> seconds, but you can
		2262	override this delay with this environment variable (or by setting
		2263	the C<$AnyEvent::MAX_SIGNAL_LATENCY> variable before creating signal
		2264	watchers).
		2265
		2266	Lower values increase CPU (and energy) usage, higher values can introduce
		2267	long delays when reaping children or waiting for signals.
		2268
		2269	The L<AnyEvent::Async> module, if available, will be used to avoid this
		2270	polling (with most event loops).
		2271
1477	=item C<PERL_ANYEVENT_RESOLV_CONF>	2272	=item C<PERL_ANYEVENT_RESOLV_CONF>
1478		2273
1479	The file to use instead of F</etc/resolv.conf> (or OS-specific	2274	The absolute path to a F<resolv.conf>-style file to use instead of
1480	configuration) in the default resolver. When set to the empty string, no	2275	F</etc/resolv.conf> (or the OS-specific configuration) in the default
1481	default config will be used.	2276	resolver, or the empty string to select the default configuration.
1482		2277
1483	=item C<PERL_ANYEVENT_CA_FILE>, C<PERL_ANYEVENT_CA_PATH>.	2278	=item C<PERL_ANYEVENT_CA_FILE>, C<PERL_ANYEVENT_CA_PATH>.
1484		2279
1485	When neither C<ca_file> nor C<ca_path> was specified during	2280	When neither C<ca_file> nor C<ca_path> was specified during
1486	L<AnyEvent::TLS> context creation, and either of these environment	2281	L<AnyEvent::TLS> context creation, and either of these environment
1487	variables exist, they will be used to specify CA certificate locations	2282	variables are nonempty, they will be used to specify CA certificate
1488	instead of a system-dependent default.	2283	locations instead of a system-dependent default.
		2284
		2285	=item C<PERL_ANYEVENT_AVOID_GUARD> and C<PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT>
		2286
		2287	When these are set to C<1>, then the respective modules are not
		2288	loaded. Mostly good for testing AnyEvent itself.
1489		2289
1490	=back	2290	=back
1491		2291
1492	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE	2292	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE
1493		2293
…		…
1551	warn "read: $input\n"; # output what has been read	2351	warn "read: $input\n"; # output what has been read
1552	$cv->send if $input =~ /^q/i; # quit program if /^q/i	2352	$cv->send if $input =~ /^q/i; # quit program if /^q/i
1553	},	2353	},
1554	);	2354	);
1555		2355
1556	my $time_watcher; # can only be used once
1557
1558	sub new_timer {
1559	$timer = AnyEvent->timer (after => 1, cb => sub {	2356	my $time_watcher = AnyEvent->timer (after => 1, interval => 1, cb => sub {
1560	warn "timeout\n"; # print 'timeout' about every second	2357	warn "timeout\n"; # print 'timeout' at most every second
1561	&new_timer; # and restart the time
1562	});	2358	});
1563	}
1564
1565	new_timer; # create first timer
1566		2359
1567	$cv->recv; # wait until user enters /^q/i	2360	$cv->recv; # wait until user enters /^q/i
1568		2361
1569	=head1 REAL-WORLD EXAMPLE	2362	=head1 REAL-WORLD EXAMPLE
1570		2363
…		…
1643		2436
1644	The actual code goes further and collects all errors (C<die>s, exceptions)	2437	The actual code goes further and collects all errors (C<die>s, exceptions)
1645	that occurred during request processing. The C<result> method detects	2438	that occurred during request processing. The C<result> method detects
1646	whether an exception as thrown (it is stored inside the $txn object)	2439	whether an exception as thrown (it is stored inside the $txn object)
1647	and just throws the exception, which means connection errors and other	2440	and just throws the exception, which means connection errors and other
1648	problems get reported tot he code that tries to use the result, not in a	2441	problems get reported to the code that tries to use the result, not in a
1649	random callback.	2442	random callback.
1650		2443
1651	All of this enables the following usage styles:	2444	All of this enables the following usage styles:
1652		2445
1653	1. Blocking:	2446	1. Blocking:
…		…
1701	through AnyEvent. The benchmark creates a lot of timers (with a zero	2494	through AnyEvent. The benchmark creates a lot of timers (with a zero
1702	timeout) and I/O watchers (watching STDOUT, a pty, to become writable,	2495	timeout) and I/O watchers (watching STDOUT, a pty, to become writable,
1703	which it is), lets them fire exactly once and destroys them again.	2496	which it is), lets them fire exactly once and destroys them again.
1704		2497
1705	Source code for this benchmark is found as F<eg/bench> in the AnyEvent	2498	Source code for this benchmark is found as F<eg/bench> in the AnyEvent
1706	distribution.	2499	distribution. It uses the L<AE> interface, which makes a real difference
		2500	for the EV and Perl backends only.
1707		2501
1708	=head3 Explanation of the columns	2502	=head3 Explanation of the columns
1709		2503
1710	I<watcher> is the number of event watchers created/destroyed. Since	2504	I<watcher> is the number of event watchers created/destroyed. Since
1711	different event models feature vastly different performances, each event	2505	different event models feature vastly different performances, each event
…		…
1732	watcher.	2526	watcher.
1733		2527
1734	=head3 Results	2528	=head3 Results
1735		2529
1736	name watchers bytes create invoke destroy comment	2530	name watchers bytes create invoke destroy comment
1737	EV/EV 400000 224 0.47 0.35 0.27 EV native interface	2531	EV/EV 100000 223 0.47 0.43 0.27 EV native interface
1738	EV/Any 100000 224 2.88 0.34 0.27 EV + AnyEvent watchers	2532	EV/Any 100000 223 0.48 0.42 0.26 EV + AnyEvent watchers
1739	CoroEV/Any 100000 224 2.85 0.35 0.28 coroutines + Coro::Signal	2533	Coro::EV/Any 100000 223 0.47 0.42 0.26 coroutines + Coro::Signal
1740	Perl/Any 100000 452 4.13 0.73 0.95 pure perl implementation	2534	Perl/Any 100000 431 2.70 0.74 0.92 pure perl implementation
1741	Event/Event 16000 517 32.20 31.80 0.81 Event native interface	2535	Event/Event 16000 516 31.16 31.84 0.82 Event native interface
1742	Event/Any 16000 590 35.85 31.55 1.06 Event + AnyEvent watchers	2536	Event/Any 16000 1203 42.61 34.79 1.80 Event + AnyEvent watchers
1743	IOAsync/Any 16000 989 38.10 32.77 11.13 via IO::Async::Loop::IO_Poll	2537	IOAsync/Any 16000 1911 41.92 27.45 16.81 via IO::Async::Loop::IO_Poll
1744	IOAsync/Any 16000 990 37.59 29.50 10.61 via IO::Async::Loop::Epoll	2538	IOAsync/Any 16000 1726 40.69 26.37 15.25 via IO::Async::Loop::Epoll
1745	Glib/Any 16000 1357 102.33 12.31 51.00 quadratic behaviour	2539	Glib/Any 16000 1118 89.00 12.57 51.17 quadratic behaviour
1746	Tk/Any 2000 1860 27.20 66.31 14.00 SEGV with >> 2000 watchers	2540	Tk/Any 2000 1346 20.96 10.75 8.00 SEGV with >> 2000 watchers
1747	POE/Event 2000 6328 109.99 751.67 14.02 via POE::Loop::Event	2541	POE/Any 2000 6951 108.97 795.32 14.24 via POE::Loop::Event
1748	POE/Select 2000 6027 94.54 809.13 579.80 via POE::Loop::Select	2542	POE/Any 2000 6648 94.79 774.40 575.51 via POE::Loop::Select
1749		2543
1750	=head3 Discussion	2544	=head3 Discussion
1751		2545
1752	The benchmark does I<not> measure scalability of the event loop very	2546	The benchmark does I<not> measure scalability of the event loop very
1753	well. For example, a select-based event loop (such as the pure perl one)	2547	well. For example, a select-based event loop (such as the pure perl one)
…		…
1765	benchmark machine, handling an event takes roughly 1600 CPU cycles with	2559	benchmark machine, handling an event takes roughly 1600 CPU cycles with
1766	EV, 3100 CPU cycles with AnyEvent's pure perl loop and almost 3000000 CPU	2560	EV, 3100 CPU cycles with AnyEvent's pure perl loop and almost 3000000 CPU
1767	cycles with POE.	2561	cycles with POE.
1768		2562
1769	C<EV> is the sole leader regarding speed and memory use, which are both	2563	C<EV> is the sole leader regarding speed and memory use, which are both
1770	maximal/minimal, respectively. Even when going through AnyEvent, it uses	2564	maximal/minimal, respectively. When using the L<AE> API there is zero
		2565	overhead (when going through the AnyEvent API create is about 5-6 times
		2566	slower, with other times being equal, so still uses far less memory than
1771	far less memory than any other event loop and is still faster than Event	2567	any other event loop and is still faster than Event natively).
1772	natively.
1773		2568
1774	The pure perl implementation is hit in a few sweet spots (both the	2569	The pure perl implementation is hit in a few sweet spots (both the
1775	constant timeout and the use of a single fd hit optimisations in the perl	2570	constant timeout and the use of a single fd hit optimisations in the perl
1776	interpreter and the backend itself). Nevertheless this shows that it	2571	interpreter and the backend itself). Nevertheless this shows that it
1777	adds very little overhead in itself. Like any select-based backend its	2572	adds very little overhead in itself. Like any select-based backend its
…		…
1825	(even when used without AnyEvent), but most event loops have acceptable	2620	(even when used without AnyEvent), but most event loops have acceptable
1826	performance with or without AnyEvent.	2621	performance with or without AnyEvent.
1827		2622
1828	=item * The overhead AnyEvent adds is usually much smaller than the overhead of	2623	=item * The overhead AnyEvent adds is usually much smaller than the overhead of
1829	the actual event loop, only with extremely fast event loops such as EV	2624	the actual event loop, only with extremely fast event loops such as EV
1830	adds AnyEvent significant overhead.	2625	does AnyEvent add significant overhead.
1831		2626
1832	=item * You should avoid POE like the plague if you want performance or	2627	=item * You should avoid POE like the plague if you want performance or
1833	reasonable memory usage.	2628	reasonable memory usage.
1834		2629
1835	=back	2630	=back
…		…
1851	In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100	2646	In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100
1852	(1%) are active. This mirrors the activity of large servers with many	2647	(1%) are active. This mirrors the activity of large servers with many
1853	connections, most of which are idle at any one point in time.	2648	connections, most of which are idle at any one point in time.
1854		2649
1855	Source code for this benchmark is found as F<eg/bench2> in the AnyEvent	2650	Source code for this benchmark is found as F<eg/bench2> in the AnyEvent
1856	distribution.	2651	distribution. It uses the L<AE> interface, which makes a real difference
		2652	for the EV and Perl backends only.
1857		2653
1858	=head3 Explanation of the columns	2654	=head3 Explanation of the columns
1859		2655
1860	I<sockets> is the number of sockets, and twice the number of "servers" (as	2656	I<sockets> is the number of sockets, and twice the number of "servers" (as
1861	each server has a read and write socket end).	2657	each server has a read and write socket end).
…		…
1869	a new one that moves the timeout into the future.	2665	a new one that moves the timeout into the future.
1870		2666
1871	=head3 Results	2667	=head3 Results
1872		2668
1873	name sockets create request	2669	name sockets create request
1874	EV 20000 69.01 11.16	2670	EV 20000 62.66 7.99
1875	Perl 20000 73.32 35.87	2671	Perl 20000 68.32 32.64
1876	IOAsync 20000 157.00 98.14 epoll	2672	IOAsync 20000 174.06 101.15 epoll
1877	IOAsync 20000 159.31 616.06 poll	2673	IOAsync 20000 174.67 610.84 poll
1878	Event 20000 212.62 257.32	2674	Event 20000 202.69 242.91
1879	Glib 20000 651.16 1896.30	2675	Glib 20000 557.01 1689.52
1880	POE 20000 349.67 12317.24 uses POE::Loop::Event	2676	POE 20000 341.54 12086.32 uses POE::Loop::Event
1881		2677
1882	=head3 Discussion	2678	=head3 Discussion
1883		2679
1884	This benchmark I<does> measure scalability and overall performance of the	2680	This benchmark I<does> measure scalability and overall performance of the
1885	particular event loop.	2681	particular event loop.
…		…
2011	As you can see, the AnyEvent + EV combination even beats the	2807	As you can see, the AnyEvent + EV combination even beats the
2012	hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl	2808	hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl
2013	backend easily beats IO::Lambda and POE.	2809	backend easily beats IO::Lambda and POE.
2014		2810
2015	And even the 100% non-blocking version written using the high-level (and	2811	And even the 100% non-blocking version written using the high-level (and
2016	slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda by a	2812	slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda
2017	large margin, even though it does all of DNS, tcp-connect and socket I/O	2813	higher level ("unoptimised") abstractions by a large margin, even though
2018	in a non-blocking way.	2814	it does all of DNS, tcp-connect and socket I/O in a non-blocking way.
2019		2815
2020	The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and	2816	The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and
2021	F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are	2817	F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are
2022	part of the IO::lambda distribution and were used without any changes.	2818	part of the IO::Lambda distribution and were used without any changes.
2023		2819
2024		2820
2025	=head1 SIGNALS	2821	=head1 SIGNALS
2026		2822
2027	AnyEvent currently installs handlers for these signals:	2823	AnyEvent currently installs handlers for these signals:
…		…
2032		2828
2033	A handler for C<SIGCHLD> is installed by AnyEvent's child watcher	2829	A handler for C<SIGCHLD> is installed by AnyEvent's child watcher
2034	emulation for event loops that do not support them natively. Also, some	2830	emulation for event loops that do not support them natively. Also, some
2035	event loops install a similar handler.	2831	event loops install a similar handler.
2036		2832
2037	If, when AnyEvent is loaded, SIGCHLD is set to IGNORE, then AnyEvent will	2833	Additionally, when AnyEvent is loaded and SIGCHLD is set to IGNORE, then
2038	reset it to default, to avoid losing child exit statuses.	2834	AnyEvent will reset it to default, to avoid losing child exit statuses.
2039		2835
2040	=item SIGPIPE	2836	=item SIGPIPE
2041		2837
2042	A no-op handler is installed for C<SIGPIPE> when C<$SIG{PIPE}> is C<undef>	2838	A no-op handler is installed for C<SIGPIPE> when C<$SIG{PIPE}> is C<undef>
2043	when AnyEvent gets loaded.	2839	when AnyEvent gets loaded.
…		…
2061	if $SIG{CHLD} eq 'IGNORE';	2857	if $SIG{CHLD} eq 'IGNORE';
2062		2858
2063	$SIG{PIPE} = sub { }	2859	$SIG{PIPE} = sub { }
2064	unless defined $SIG{PIPE};	2860	unless defined $SIG{PIPE};
2065		2861
		2862	=head1 RECOMMENDED/OPTIONAL MODULES
		2863
		2864	One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and
		2865	its built-in modules) are required to use it.
		2866
		2867	That does not mean that AnyEvent won't take advantage of some additional
		2868	modules if they are installed.
		2869
		2870	This section explains which additional modules will be used, and how they
		2871	affect AnyEvent's operation.
		2872
		2873	=over 4
		2874
		2875	=item L<Async::Interrupt>
		2876
		2877	This slightly arcane module is used to implement fast signal handling: To
		2878	my knowledge, there is no way to do completely race-free and quick
		2879	signal handling in pure perl. To ensure that signals still get
		2880	delivered, AnyEvent will start an interval timer to wake up perl (and
		2881	catch the signals) with some delay (default is 10 seconds, look for
		2882	C<$AnyEvent::MAX_SIGNAL_LATENCY>).
		2883
		2884	If this module is available, then it will be used to implement signal
		2885	catching, which means that signals will not be delayed, and the event loop
		2886	will not be interrupted regularly, which is more efficient (and good for
		2887	battery life on laptops).
		2888
		2889	This affects not just the pure-perl event loop, but also other event loops
		2890	that have no signal handling on their own (e.g. Glib, Tk, Qt).
		2891
		2892	Some event loops (POE, Event, Event::Lib) offer signal watchers natively,
		2893	and either employ their own workarounds (POE) or use AnyEvent's workaround
		2894	(using C<$AnyEvent::MAX_SIGNAL_LATENCY>). Installing L<Async::Interrupt>
		2895	does nothing for those backends.
		2896
		2897	=item L<EV>
		2898
		2899	This module isn't really "optional", as it is simply one of the backend
		2900	event loops that AnyEvent can use. However, it is simply the best event
		2901	loop available in terms of features, speed and stability: It supports
		2902	the AnyEvent API optimally, implements all the watcher types in XS, does
		2903	automatic timer adjustments even when no monotonic clock is available,
		2904	can take avdantage of advanced kernel interfaces such as C<epoll> and
		2905	C<kqueue>, and is the fastest backend I<by far>. You can even embed
		2906	L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>).
		2907
		2908	If you only use backends that rely on another event loop (e.g. C<Tk>),
		2909	then this module will do nothing for you.
		2910
		2911	=item L<Guard>
		2912
		2913	The guard module, when used, will be used to implement
		2914	C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a
		2915	lot less memory), but otherwise doesn't affect guard operation much. It is
		2916	purely used for performance.
		2917
		2918	=item L<JSON> and L<JSON::XS>
		2919
		2920	One of these modules is required when you want to read or write JSON data
		2921	via L<AnyEvent::Handle>. L<JSON> is also written in pure-perl, but can take
		2922	advantage of the ultra-high-speed L<JSON::XS> module when it is installed.
		2923
		2924	=item L<Net::SSLeay>
		2925
		2926	Implementing TLS/SSL in Perl is certainly interesting, but not very
		2927	worthwhile: If this module is installed, then L<AnyEvent::Handle> (with
		2928	the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL.
		2929
		2930	=item L<Time::HiRes>
		2931
		2932	This module is part of perl since release 5.008. It will be used when the
		2933	chosen event library does not come with a timing source of its own. The
		2934	pure-perl event loop (L<AnyEvent::Loop>) will additionally load it to
		2935	try to use a monotonic clock for timing stability.
		2936
		2937	=item L<AnyEvent::AIO> (and L<IO::AIO>)
		2938
		2939	The default implementation of L<AnyEvent::IO> is to do I/O synchronously,
		2940	stopping programs while they access the disk, which is fine for a lot of
		2941	programs.
		2942
		2943	Installing AnyEvent::AIO (and its IO::AIO dependency) makes it switch to
		2944	a true asynchronous implementation, so event processing can continue even
		2945	while waiting for disk I/O.
		2946
		2947	=back
		2948
		2949
2066	=head1 FORK	2950	=head1 FORK
2067		2951
2068	Most event libraries are not fork-safe. The ones who are usually are	2952	Most event libraries are not fork-safe. The ones who are usually are
2069	because they rely on inefficient but fork-safe C<select> or C<poll>	2953	because they rely on inefficient but fork-safe C<select> or C<poll> calls
2070	calls. Only L<EV> is fully fork-aware.	2954	- higher performance APIs such as BSD's kqueue or the dreaded Linux epoll
		2955	are usually badly thought-out hacks that are incompatible with fork in
		2956	one way or another. Only L<EV> is fully fork-aware and ensures that you
		2957	continue event-processing in both parent and child (or both, if you know
		2958	what you are doing).
		2959
		2960	This means that, in general, you cannot fork and do event processing in
		2961	the child if the event library was initialised before the fork (which
		2962	usually happens when the first AnyEvent watcher is created, or the library
		2963	is loaded).
2071		2964
2072	If you have to fork, you must either do so I<before> creating your first	2965	If you have to fork, you must either do so I<before> creating your first
2073	watcher OR you must not use AnyEvent at all in the child.	2966	watcher OR you must not use AnyEvent at all in the child OR you must do
		2967	something completely out of the scope of AnyEvent (see below).
		2968
		2969	The problem of doing event processing in the parent I<and> the child
		2970	is much more complicated: even for backends that I<are> fork-aware or
		2971	fork-safe, their behaviour is not usually what you want: fork clones all
		2972	watchers, that means all timers, I/O watchers etc. are active in both
		2973	parent and child, which is almost never what you want. Using C<exec>
		2974	to start worker children from some kind of manage prrocess is usually
		2975	preferred, because it is much easier and cleaner, at the expense of having
		2976	to have another binary.
		2977
		2978	In addition to logical problems with fork, there are also implementation
		2979	problems. For example, on POSIX systems, you cannot fork at all in Perl
		2980	code if a thread (I am talking of pthreads here) was ever created in the
		2981	process, and this is just the tip of the iceberg. In general, using fork
		2982	from Perl is difficult, and attempting to use fork without an exec to
		2983	implement some kind of parallel processing is almost certainly doomed.
		2984
		2985	To safely fork and exec, you should use a module such as
		2986	L<Proc::FastSpawn> that let's you safely fork and exec new processes.
		2987
		2988	If you want to do multiprocessing using processes, you can
		2989	look at the L<AnyEvent::Fork> module (and some related modules
		2990	such as L<AnyEvent::Fork::RPC>, L<AnyEvent::Fork::Pool> and
		2991	L<AnyEvent::Fork::Remote>). This module allows you to safely create
		2992	subprocesses without any limitations - you can use X11 toolkits or
		2993	AnyEvent in the children created by L<AnyEvent::Fork> safely and without
		2994	any special precautions.
2074		2995
2075		2996
2076	=head1 SECURITY CONSIDERATIONS	2997	=head1 SECURITY CONSIDERATIONS
2077		2998
2078	AnyEvent can be forced to load any event model via	2999	AnyEvent can be forced to load any event model via
…		…
2108	pronounced).	3029	pronounced).
2109		3030
2110		3031
2111	=head1 SEE ALSO	3032	=head1 SEE ALSO
2112		3033
2113	Utility functions: L<AnyEvent::Util>.	3034	Tutorial/Introduction: L<AnyEvent::Intro>.
2114		3035
2115	Event modules: L<EV>, L<EV::Glib>, L<Glib::EV>, L<Event>, L<Glib::Event>,	3036	FAQ: L<AnyEvent::FAQ>.
2116	L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.	3037
		3038	Utility functions: L<AnyEvent::Util> (misc. grab-bag), L<AnyEvent::Log>
		3039	(simply logging).
		3040
		3041	Development/Debugging: L<AnyEvent::Strict> (stricter checking),
		3042	L<AnyEvent::Debug> (interactive shell, watcher tracing).
		3043
		3044	Supported event modules: L<AnyEvent::Loop>, L<EV>, L<EV::Glib>,
		3045	L<Glib::EV>, L<Event>, L<Glib::Event>, L<Glib>, L<Tk>, L<Event::Lib>,
		3046	L<Qt>, L<POE>, L<FLTK>.
2117		3047
2118	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,	3048	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,
2119	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,	3049	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,
2120	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,	3050	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,
2121	L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>.	3051	L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>, L<Anyevent::Impl::Irssi>,
		3052	L<AnyEvent::Impl::FLTK>.
2122		3053
2123	Non-blocking file handles, sockets, TCP clients and	3054	Non-blocking handles, pipes, stream sockets, TCP clients and
2124	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.	3055	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.
2125		3056
		3057	Asynchronous File I/O: L<AnyEvent::IO>.
		3058
2126	Asynchronous DNS: L<AnyEvent::DNS>.	3059	Asynchronous DNS: L<AnyEvent::DNS>.
2127		3060
2128	Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>,	3061	Thread support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>.
2129	L<Coro::Event>,
2130		3062
2131	Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::XMPP>,	3063	Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::IRC>,
2132	L<AnyEvent::HTTP>.	3064	L<AnyEvent::HTTP>.
2133		3065
2134		3066
2135	=head1 AUTHOR	3067	=head1 AUTHOR
2136		3068
2137	Marc Lehmann <schmorp@schmorp.de>	3069	Marc Lehmann <schmorp@schmorp.de>
2138	http://home.schmorp.de/	3070	http://anyevent.schmorp.de
2139		3071
2140	=cut	3072	=cut
2141		3073
2142	1	3074	1
2143		3075

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