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Revision 1.306 by root, Tue Dec 15 05:49:13 2009 UTC vs.
Revision 1.379 by root, Fri Aug 26 18:09:04 2011 UTC

1	=head1 NAME	1	=head1 NAME
2		2
3	AnyEvent - the DBI of event loop programming	3	AnyEvent - the DBI of event loop programming
4		4
5	EV, Event, Glib, Tk, Perl, Event::Lib, Irssi, rxvt-unicode, IO::Async, Qt	5	EV, Event, Glib, Tk, Perl, Event::Lib, Irssi, rxvt-unicode, IO::Async, Qt,
6	and POE are various supported event loops/environments.	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
…		…
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.
45		48
46	=head1 SUPPORT	49	=head1 SUPPORT
47		50
		51	An FAQ document is available as L<AnyEvent::FAQ>.
		52
48	There is a mailinglist for discussing all things AnyEvent, and an IRC	53	There also is a mailinglist for discussing all things AnyEvent, and an IRC
49	channel, too.	54	channel, too.
50		55
51	See the AnyEvent project page at the B<Schmorpforge Ta-Sa Software	56	See the AnyEvent project page at the B<Schmorpforge Ta-Sa Software
52	Repository>, at L<http://anyevent.schmorp.de>, for more info.	57	Repository>, at L<http://anyevent.schmorp.de>, for more info.
53		58
…		…
73	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
74	model you use.	79	model you use.
75		80
76	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
77	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
78	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
79	cannot use anything else, as they are simply incompatible to everything	84	cannot use anything else, as they are simply incompatible to everything
80	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
81	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.
82		87
83	AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works	88	AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works
84	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
85	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
86	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
87	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
88	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
89	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,
90	to AnyEvent, too, so it is future-proof).	95	so it is future-proof).
91		96
92	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
93	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
94	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
95	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
96	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
97	technically possible.	102	technically possible.
98		103
99	Of course, AnyEvent comes with a big (and fully optional!) toolbox	104	Of course, AnyEvent comes with a big (and fully optional!) toolbox
100	of useful functionality, such as an asynchronous DNS resolver, 100%	105	of useful functionality, such as an asynchronous DNS resolver, 100%
…		…
106	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
107	model, you should I<not> use this module.	112	model, you should I<not> use this module.
108		113
109	=head1 DESCRIPTION	114	=head1 DESCRIPTION
110		115
111	L<AnyEvent> provides an identical interface to multiple event loops. This	116	L<AnyEvent> provides a uniform interface to various event loops. This
112	allows module authors to utilise an event loop without forcing module	117	allows module authors to use event loop functionality without forcing
113	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
114	peacefully at any one time).	119	than one event loop cannot coexist peacefully).
115		120
116	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>
117	module.	122	module.
118		123
119	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
120	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
121	following modules is already loaded: L<EV>,	126	following modules is already loaded: L<EV>, L<AnyEvent::Loop>,
122	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
123	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
124	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
125	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
126	be successfully loaded will be used. If, after this, still none could be	131	the other two are not normally tried.
127	found, AnyEvent will fall back to a pure-perl event loop, which is not
128	very efficient, but should work everywhere.
129		132
130	Because AnyEvent first checks for modules that are already loaded, loading	133	Because AnyEvent first checks for modules that are already loaded, loading
131	an event model explicitly before first using AnyEvent will likely make	134	an event model explicitly before first using AnyEvent will likely make
132	that model the default. For example:	135	that model the default. For example:
133		136
…		…
135	use AnyEvent;	138	use AnyEvent;
136		139
137	# .. AnyEvent will likely default to Tk	140	# .. AnyEvent will likely default to Tk
138		141
139	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
140	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,
141	use AnyEvent so their modules work together with others seamlessly...	144	as very few modules hardcode event loops without announcing this very
		145	loudly.
142		146
143	The pure-perl implementation of AnyEvent is called	147	The pure-perl implementation of AnyEvent is called C<AnyEvent::Loop>. Like
144	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
145	explicitly and enjoy the high availability of that event loop :)	149	availability of that event loop :)
146		150
147	=head1 WATCHERS	151	=head1 WATCHERS
148		152
149	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
150	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
…		…
155	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
156	is in control).	160	is in control).
157		161
158	Note that B<callbacks must not permanently change global variables>	162	Note that B<callbacks must not permanently change global variables>
159	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<<
160	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
161	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
162	widely between event loops.	166	widely between event loops.
163		167
164	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
165	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
166	to it).	170	to it).
167		171
168	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.
169		173
170	Many watchers either are used with "recursion" (repeating timers for	174	Many watchers either are used with "recursion" (repeating timers for
171	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.
172		176
173	An any way to achieve that is this pattern:	177	One way to achieve that is this pattern:
174		178
175	my $w; $w = AnyEvent->type (arg => value ..., cb => sub {	179	my $w; $w = AnyEvent->type (arg => value ..., cb => sub {
176	# you can use $w here, for example to undef it	180	# you can use $w here, for example to undef it
177	undef $w;	181	undef $w;
178	});	182	});
…		…
210		214
211	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.
212	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
213	underlying file descriptor.	217	underlying file descriptor.
214		218
215	Some event loops issue spurious readyness notifications, so you should	219	Some event loops issue spurious readiness notifications, so you should
216	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
217	handles.	221	handles.
218		222
219	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
220	watcher.	224	watcher.
…		…
244		248
245	Although the callback might get passed parameters, their value and	249	Although the callback might get passed parameters, their value and
246	presence is undefined and you cannot rely on them. Portable AnyEvent	250	presence is undefined and you cannot rely on them. Portable AnyEvent
247	callbacks cannot use arguments passed to time watcher callbacks.	251	callbacks cannot use arguments passed to time watcher callbacks.
248		252
249	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
250	parameter, C<interval>, as a strictly positive number (> 0), then the	254	parameter, C<interval>, as a strictly positive number (> 0), then the
251	callback will be invoked regularly at that interval (in fractional	255	callback will be invoked regularly at that interval (in fractional
252	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
253	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.
254		258
255	The callback will be rescheduled before invoking the callback, but no	259	The callback will be rescheduled before invoking the callback, but no
256	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
257	only approximate.	261	only approximate.
258		262
259	Example: fire an event after 7.7 seconds.	263	Example: fire an event after 7.7 seconds.
260		264
261	my $w = AnyEvent->timer (after => 7.7, cb => sub {	265	my $w = AnyEvent->timer (after => 7.7, cb => sub {
…		…
279		283
280	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
281	use absolute time internally. This makes a difference when your clock	285	use absolute time internally. This makes a difference when your clock
282	"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
283	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
284	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.
285		289
286	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
287	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
288	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)
289	timers.	293	timers.
290		294
291	AnyEvent always prefers relative timers, if available, matching the	295	AnyEvent always prefers relative timers, if available, matching the
292	AnyEvent API.	296	AnyEvent API.
…		…
314	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
315	function to call when you want to know the current time.>	319	function to call when you want to know the current time.>
316		320
317	This function is also often faster then C<< AnyEvent->time >>, and	321	This function is also often faster then C<< AnyEvent->time >>, and
318	thus the preferred method if you want some timestamp (for example,	322	thus the preferred method if you want some timestamp (for example,
319	L<AnyEvent::Handle> uses this to update it's activity timeouts).	323	L<AnyEvent::Handle> uses this to update its activity timeouts).
320		324
321	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
322	with your timing, you can skip it without bad conscience.	326	with your timing; you can skip it without a bad conscience.
323		327
324	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>
325	and L<EV> and the following set-up:	329	and L<EV> and the following set-up:
326		330
327	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
328	time=500 (assume no other callbacks delay processing). In your callback,	332	time=500 (assume no other callbacks delay processing). In your callback,
329	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
330	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
331	after three seconds.	335	after three seconds.
332		336
…		…
352	difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into	356	difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into
353	account.	357	account.
354		358
355	=item AnyEvent->now_update	359	=item AnyEvent->now_update
356		360
357	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
358	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 >>,
359	AnyEvent->now >>, above).	363	above).
360		364
361	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
362	this "current" time will differ substantially from the real time, which	366	this "current" time will differ substantially from the real time, which
363	might affect timers and time-outs.	367	might affect timers and time-outs.
364		368
…		…
425	=head3 Signal Races, Delays and Workarounds	429	=head3 Signal Races, Delays and Workarounds
426		430
427	Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support attaching	431	Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support attaching
428	callbacks to signals in a generic way, which is a pity, as you cannot	432	callbacks to signals in a generic way, which is a pity, as you cannot
429	do race-free signal handling in perl, requiring C libraries for	433	do race-free signal handling in perl, requiring C libraries for
430	this. AnyEvent will try to do it's best, which means in some cases,	434	this. AnyEvent will try to do its best, which means in some cases,
431	signals will be delayed. The maximum time a signal might be delayed is	435	signals will be delayed. The maximum time a signal might be delayed is
432	specified in C<$AnyEvent::MAX_SIGNAL_LATENCY> (default: 10 seconds). This	436	specified in C<$AnyEvent::MAX_SIGNAL_LATENCY> (default: 10 seconds). This
433	variable can be changed only before the first signal watcher is created,	437	variable can be changed only before the first signal watcher is created,
434	and should be left alone otherwise. This variable determines how often	438	and should be left alone otherwise. This variable determines how often
435	AnyEvent polls for signals (in case a wake-up was missed). Higher values	439	AnyEvent polls for signals (in case a wake-up was missed). Higher values
…		…
437	saving.	441	saving.
438		442
439	All these problems can be avoided by installing the optional	443	All these problems can be avoided by installing the optional
440	L<Async::Interrupt> module, which works with most event loops. It will not	444	L<Async::Interrupt> module, which works with most event loops. It will not
441	work with inherently broken event loops such as L<Event> or L<Event::Lib>	445	work with inherently broken event loops such as L<Event> or L<Event::Lib>
442	(and not with L<POE> currently, as POE does it's own workaround with	446	(and not with L<POE> currently, as POE does its own workaround with
443	one-second latency). For those, you just have to suffer the delays.	447	one-second latency). For those, you just have to suffer the delays.
444		448
445	=head2 CHILD PROCESS WATCHERS	449	=head2 CHILD PROCESS WATCHERS
446		450
447	$w = AnyEvent->child (pid => <process id>, cb => <callback>);	451	$w = AnyEvent->child (pid => <process id>, cb => <callback>);
448		452
449	You can also watch on a child process exit and catch its exit status.	453	You can also watch for a child process exit and catch its exit status.
450		454
451	The child process is specified by the C<pid> argument (one some backends,	455	The child process is specified by the C<pid> argument (on some backends,
452	using C<0> watches for any child process exit, on others this will	456	using C<0> watches for any child process exit, on others this will
453	croak). The watcher will be triggered only when the child process has	457	croak). The watcher will be triggered only when the child process has
454	finished and an exit status is available, not on any trace events	458	finished and an exit status is available, not on any trace events
455	(stopped/continued).	459	(stopped/continued).
456		460
…		…
478	thing in an AnyEvent program, you I<have> to create at least one	482	thing in an AnyEvent program, you I<have> to create at least one
479	watcher before you C<fork> the child (alternatively, you can call	483	watcher before you C<fork> the child (alternatively, you can call
480	C<AnyEvent::detect>).	484	C<AnyEvent::detect>).
481		485
482	As most event loops do not support waiting for child events, they will be	486	As most event loops do not support waiting for child events, they will be
483	emulated by AnyEvent in most cases, in which the latency and race problems	487	emulated by AnyEvent in most cases, in which case the latency and race
484	mentioned in the description of signal watchers apply.	488	problems mentioned in the description of signal watchers apply.
485		489
486	Example: fork a process and wait for it	490	Example: fork a process and wait for it
487		491
488	my $done = AnyEvent->condvar;	492	my $done = AnyEvent->condvar;
489		493
…		…
503		507
504	=head2 IDLE WATCHERS	508	=head2 IDLE WATCHERS
505		509
506	$w = AnyEvent->idle (cb => <callback>);	510	$w = AnyEvent->idle (cb => <callback>);
507		511
508	Sometimes there is a need to do something, but it is not so important	512	This will repeatedly invoke the callback after the process becomes idle,
509	to do it instantly, but only when there is nothing better to do. This	513	until either the watcher is destroyed or new events have been detected.
510	"nothing better to do" is usually defined to be "no other events need
511	attention by the event loop".
512		514
513	Idle watchers ideally get invoked when the event loop has nothing	515	Idle watchers are useful when there is a need to do something, but it
514	better to do, just before it would block the process to wait for new	516	is not so important (or wise) to do it instantly. The callback will be
515	events. Instead of blocking, the idle watcher is invoked.	517	invoked only when there is "nothing better to do", which is usually
		518	defined as "all outstanding events have been handled and no new events
		519	have been detected". That means that idle watchers ideally get invoked
		520	when the event loop has just polled for new events but none have been
		521	detected. Instead of blocking to wait for more events, the idle watchers
		522	will be invoked.
516		523
517	Most event loops unfortunately do not really support idle watchers (only	524	Unfortunately, most event loops do not really support idle watchers (only
518	EV, Event and Glib do it in a usable fashion) - for the rest, AnyEvent	525	EV, Event and Glib do it in a usable fashion) - for the rest, AnyEvent
519	will simply call the callback "from time to time".	526	will simply call the callback "from time to time".
520		527
521	Example: read lines from STDIN, but only process them when the	528	Example: read lines from STDIN, but only process them when the
522	program is otherwise idle:	529	program is otherwise idle:
…		…
550	will actively watch for new events and call your callbacks.	557	will actively watch for new events and call your callbacks.
551		558
552	AnyEvent is slightly different: it expects somebody else to run the event	559	AnyEvent is slightly different: it expects somebody else to run the event
553	loop and will only block when necessary (usually when told by the user).	560	loop and will only block when necessary (usually when told by the user).
554		561
555	The instrument to do that is called a "condition variable", so called	562	The tool to do that is called a "condition variable", so called because
556	because they represent a condition that must become true.	563	they represent a condition that must become true.
557		564
558	Now is probably a good time to look at the examples further below.	565	Now is probably a good time to look at the examples further below.
559		566
560	Condition variables can be created by calling the C<< AnyEvent->condvar	567	Condition variables can be created by calling the C<< AnyEvent->condvar
561	>> method, usually without arguments. The only argument pair allowed is	568	>> method, usually without arguments. The only argument pair allowed is
…		…
566	After creation, the condition variable is "false" until it becomes "true"	573	After creation, the condition variable is "false" until it becomes "true"
567	by calling the C<send> method (or calling the condition variable as if it	574	by calling the C<send> method (or calling the condition variable as if it
568	were a callback, read about the caveats in the description for the C<<	575	were a callback, read about the caveats in the description for the C<<
569	->send >> method).	576	->send >> method).
570		577
571	Condition variables are similar to callbacks, except that you can	578	Since condition variables are the most complex part of the AnyEvent API, here are
572	optionally wait for them. They can also be called merge points - points	579	some different mental models of what they are - pick the ones you can connect to:
573	in time where multiple outstanding events have been processed. And yet	580
574	another way to call them is transactions - each condition variable can be	581	=over 4
575	used to represent a transaction, which finishes at some point and delivers	582
576	a result. And yet some people know them as "futures" - a promise to	583	=item * Condition variables are like callbacks - you can call them (and pass them instead
577	compute/deliver something that you can wait for.	584	of callbacks). Unlike callbacks however, you can also wait for them to be called.
		585
		586	=item * Condition variables are signals - one side can emit or send them,
		587	the other side can wait for them, or install a handler that is called when
		588	the signal fires.
		589
		590	=item * Condition variables are like "Merge Points" - points in your program
		591	where you merge multiple independent results/control flows into one.
		592
		593	=item * Condition variables represent a transaction - functions that start
		594	some kind of transaction can return them, leaving the caller the choice
		595	between waiting in a blocking fashion, or setting a callback.
		596
		597	=item * Condition variables represent future values, or promises to deliver
		598	some result, long before the result is available.
		599
		600	=back
578		601
579	Condition variables are very useful to signal that something has finished,	602	Condition variables are very useful to signal that something has finished,
580	for example, if you write a module that does asynchronous http requests,	603	for example, if you write a module that does asynchronous http requests,
581	then a condition variable would be the ideal candidate to signal the	604	then a condition variable would be the ideal candidate to signal the
582	availability of results. The user can either act when the callback is	605	availability of results. The user can either act when the callback is
…		…
595		618
596	Condition variables are represented by hash refs in perl, and the keys	619	Condition variables are represented by hash refs in perl, and the keys
597	used by AnyEvent itself are all named C<_ae_XXX> to make subclassing	620	used by AnyEvent itself are all named C<_ae_XXX> to make subclassing
598	easy (it is often useful to build your own transaction class on top of	621	easy (it is often useful to build your own transaction class on top of
599	AnyEvent). To subclass, use C<AnyEvent::CondVar> as base class and call	622	AnyEvent). To subclass, use C<AnyEvent::CondVar> as base class and call
600	it's C<new> method in your own C<new> method.	623	its C<new> method in your own C<new> method.
601		624
602	There are two "sides" to a condition variable - the "producer side" which	625	There are two "sides" to a condition variable - the "producer side" which
603	eventually calls C<< -> send >>, and the "consumer side", which waits	626	eventually calls C<< -> send >>, and the "consumer side", which waits
604	for the send to occur.	627	for the send to occur.
605		628
606	Example: wait for a timer.	629	Example: wait for a timer.
607		630
608	# wait till the result is ready	631	# condition: "wait till the timer is fired"
609	my $result_ready = AnyEvent->condvar;	632	my $timer_fired = AnyEvent->condvar;
610		633
611	# do something such as adding a timer	634	# create the timer - we could wait for, say
612	# or socket watcher the calls $result_ready->send	635	# a handle becomign ready, or even an
613	# when the "result" is ready.	636	# AnyEvent::HTTP request to finish, but
614	# in this case, we simply use a timer:	637	# in this case, we simply use a timer:
615	my $w = AnyEvent->timer (	638	my $w = AnyEvent->timer (
616	after => 1,	639	after => 1,
617	cb => sub { $result_ready->send },	640	cb => sub { $timer_fired->send },
618	);	641	);
619		642
620	# this "blocks" (while handling events) till the callback	643	# this "blocks" (while handling events) till the callback
621	# calls ->send	644	# calls ->send
622	$result_ready->recv;	645	$timer_fired->recv;
623		646
624	Example: wait for a timer, but take advantage of the fact that condition	647	Example: wait for a timer, but take advantage of the fact that condition
625	variables are also callable directly.	648	variables are also callable directly.
626		649
627	my $done = AnyEvent->condvar;	650	my $done = AnyEvent->condvar;
…		…
670	they were a code reference). Calling them directly is the same as calling	693	they were a code reference). Calling them directly is the same as calling
671	C<send>.	694	C<send>.
672		695
673	=item $cv->croak ($error)	696	=item $cv->croak ($error)
674		697
675	Similar to send, but causes all call's to C<< ->recv >> to invoke	698	Similar to send, but causes all calls to C<< ->recv >> to invoke
676	C<Carp::croak> with the given error message/object/scalar.	699	C<Carp::croak> with the given error message/object/scalar.
677		700
678	This can be used to signal any errors to the condition variable	701	This can be used to signal any errors to the condition variable
679	user/consumer. Doing it this way instead of calling C<croak> directly	702	user/consumer. Doing it this way instead of calling C<croak> directly
680	delays the error detetcion, but has the overwhelmign advantage that it	703	delays the error detection, but has the overwhelming advantage that it
681	diagnoses the error at the place where the result is expected, and not	704	diagnoses the error at the place where the result is expected, and not
682	deep in some event clalback without connection to the actual code causing	705	deep in some event callback with no connection to the actual code causing
683	the problem.	706	the problem.
684		707
685	=item $cv->begin ([group callback])	708	=item $cv->begin ([group callback])
686		709
687	=item $cv->end	710	=item $cv->end
…		…
725	one call to C<begin>, so the condvar waits for all calls to C<end> before	748	one call to C<begin>, so the condvar waits for all calls to C<end> before
726	sending.	749	sending.
727		750
728	The ping example mentioned above is slightly more complicated, as the	751	The ping example mentioned above is slightly more complicated, as the
729	there are results to be passwd back, and the number of tasks that are	752	there are results to be passwd back, and the number of tasks that are
730	begung can potentially be zero:	753	begun can potentially be zero:
731		754
732	my $cv = AnyEvent->condvar;	755	my $cv = AnyEvent->condvar;
733		756
734	my %result;	757	my %result;
735	$cv->begin (sub { shift->send (\%result) });	758	$cv->begin (sub { shift->send (\%result) });
…		…
756	to be called once the counter reaches C<0>, and second, it ensures that	779	to be called once the counter reaches C<0>, and second, it ensures that
757	C<send> is called even when C<no> hosts are being pinged (the loop	780	C<send> is called even when C<no> hosts are being pinged (the loop
758	doesn't execute once).	781	doesn't execute once).
759		782
760	This is the general pattern when you "fan out" into multiple (but	783	This is the general pattern when you "fan out" into multiple (but
761	potentially none) subrequests: use an outer C<begin>/C<end> pair to set	784	potentially zero) subrequests: use an outer C<begin>/C<end> pair to set
762	the callback and ensure C<end> is called at least once, and then, for each	785	the callback and ensure C<end> is called at least once, and then, for each
763	subrequest you start, call C<begin> and for each subrequest you finish,	786	subrequest you start, call C<begin> and for each subrequest you finish,
764	call C<end>.	787	call C<end>.
765		788
766	=back	789	=back
…		…
773	=over 4	796	=over 4
774		797
775	=item $cv->recv	798	=item $cv->recv
776		799
777	Wait (blocking if necessary) until the C<< ->send >> or C<< ->croak	800	Wait (blocking if necessary) until the C<< ->send >> or C<< ->croak
778	>> methods have been called on c<$cv>, while servicing other watchers	801	>> methods have been called on C<$cv>, while servicing other watchers
779	normally.	802	normally.
780		803
781	You can only wait once on a condition - additional calls are valid but	804	You can only wait once on a condition - additional calls are valid but
782	will return immediately.	805	will return immediately.
783		806
…		…
800	caller decide whether the call will block or not (for example, by coupling	823	caller decide whether the call will block or not (for example, by coupling
801	condition variables with some kind of request results and supporting	824	condition variables with some kind of request results and supporting
802	callbacks so the caller knows that getting the result will not block,	825	callbacks so the caller knows that getting the result will not block,
803	while still supporting blocking waits if the caller so desires).	826	while still supporting blocking waits if the caller so desires).
804		827
805	You can ensure that C<< -recv >> never blocks by setting a callback and	828	You can ensure that C<< ->recv >> never blocks by setting a callback and
806	only calling C<< ->recv >> from within that callback (or at a later	829	only calling C<< ->recv >> from within that callback (or at a later
807	time). This will work even when the event loop does not support blocking	830	time). This will work even when the event loop does not support blocking
808	waits otherwise.	831	waits otherwise.
809		832
810	=item $bool = $cv->ready	833	=item $bool = $cv->ready
…		…
815	=item $cb = $cv->cb ($cb->($cv))	838	=item $cb = $cv->cb ($cb->($cv))
816		839
817	This is a mutator function that returns the callback set and optionally	840	This is a mutator function that returns the callback set and optionally
818	replaces it before doing so.	841	replaces it before doing so.
819		842
820	The callback will be called when the condition becomes (or already was)	843	The callback will be called when the condition becomes "true", i.e. when
821	"true", i.e. when C<send> or C<croak> are called (or were called), with	844	C<send> or C<croak> are called, with the only argument being the
822	the only argument being the condition variable itself. Calling C<recv>	845	condition variable itself. If the condition is already true, the
		846	callback is called immediately when it is set. Calling C<recv> inside
823	inside the callback or at any later time is guaranteed not to block.	847	the callback or at any later time is guaranteed not to block.
824		848
825	=back	849	=back
826		850
827	=head1 SUPPORTED EVENT LOOPS/BACKENDS	851	=head1 SUPPORTED EVENT LOOPS/BACKENDS
828		852
…		…
836	use. If EV is not installed, then AnyEvent will fall back to its own	860	use. If EV is not installed, then AnyEvent will fall back to its own
837	pure-perl implementation, which is available everywhere as it comes with	861	pure-perl implementation, which is available everywhere as it comes with
838	AnyEvent itself.	862	AnyEvent itself.
839		863
840	AnyEvent::Impl::EV based on EV (interface to libev, best choice).	864	AnyEvent::Impl::EV based on EV (interface to libev, best choice).
841	AnyEvent::Impl::Perl pure-perl implementation, fast and portable.	865	AnyEvent::Impl::Perl pure-perl AnyEvent::Loop, fast and portable.
842		866
843	=item Backends that are transparently being picked up when they are used.	867	=item Backends that are transparently being picked up when they are used.
844		868
845	These will be used when they are currently loaded when the first watcher	869	These will be used if they are already loaded when the first watcher
846	is created, in which case it is assumed that the application is using	870	is created, in which case it is assumed that the application is using
847	them. This means that AnyEvent will automatically pick the right backend	871	them. This means that AnyEvent will automatically pick the right backend
848	when the main program loads an event module before anything starts to	872	when the main program loads an event module before anything starts to
849	create watchers. Nothing special needs to be done by the main program.	873	create watchers. Nothing special needs to be done by the main program.
850		874
…		…
852	AnyEvent::Impl::Glib based on Glib, slow but very stable.	876	AnyEvent::Impl::Glib based on Glib, slow but very stable.
853	AnyEvent::Impl::Tk based on Tk, very broken.	877	AnyEvent::Impl::Tk based on Tk, very broken.
854	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.	878	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
855	AnyEvent::Impl::POE based on POE, very slow, some limitations.	879	AnyEvent::Impl::POE based on POE, very slow, some limitations.
856	AnyEvent::Impl::Irssi used when running within irssi.	880	AnyEvent::Impl::Irssi used when running within irssi.
		881	AnyEvent::Impl::IOAsync based on IO::Async.
		882	AnyEvent::Impl::Cocoa based on Cocoa::EventLoop.
		883	AnyEvent::Impl::FLTK based on FLTK (fltk 2 binding).
857		884
858	=item Backends with special needs.	885	=item Backends with special needs.
859		886
860	Qt requires the Qt::Application to be instantiated first, but will	887	Qt requires the Qt::Application to be instantiated first, but will
861	otherwise be picked up automatically. As long as the main program	888	otherwise be picked up automatically. As long as the main program
862	instantiates the application before any AnyEvent watchers are created,	889	instantiates the application before any AnyEvent watchers are created,
863	everything should just work.	890	everything should just work.
864		891
865	AnyEvent::Impl::Qt based on Qt.	892	AnyEvent::Impl::Qt based on Qt.
866		893
867	Support for IO::Async can only be partial, as it is too broken and
868	architecturally limited to even support the AnyEvent API. It also
869	is the only event loop that needs the loop to be set explicitly, so
870	it can only be used by a main program knowing about AnyEvent. See
871	L<AnyEvent::Impl::Async> for the gory details.
872
873	AnyEvent::Impl::IOAsync based on IO::Async, cannot be autoprobed.
874
875	=item Event loops that are indirectly supported via other backends.	894	=item Event loops that are indirectly supported via other backends.
876		895
877	Some event loops can be supported via other modules:	896	Some event loops can be supported via other modules:
878		897
879	There is no direct support for WxWidgets (L<Wx>) or L<Prima>.	898	There is no direct support for WxWidgets (L<Wx>) or L<Prima>.
…		…
904	Contains C<undef> until the first watcher is being created, before the	923	Contains C<undef> until the first watcher is being created, before the
905	backend has been autodetected.	924	backend has been autodetected.
906		925
907	Afterwards it contains the event model that is being used, which is the	926	Afterwards it contains the event model that is being used, which is the
908	name of the Perl class implementing the model. This class is usually one	927	name of the Perl class implementing the model. This class is usually one
909	of the C<AnyEvent::Impl:xxx> modules, but can be any other class in the	928	of the C<AnyEvent::Impl::xxx> modules, but can be any other class in the
910	case AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode> it	929	case AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode> it
911	will be C<urxvt::anyevent>).	930	will be C<urxvt::anyevent>).
912		931
913	=item AnyEvent::detect	932	=item AnyEvent::detect
914		933
915	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model	934	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model
916	if necessary. You should only call this function right before you would	935	if necessary. You should only call this function right before you would
917	have created an AnyEvent watcher anyway, that is, as late as possible at	936	have created an AnyEvent watcher anyway, that is, as late as possible at
918	runtime, and not e.g. while initialising of your module.	937	runtime, and not e.g. during initialisation of your module.
		938
		939	The effect of calling this function is as if a watcher had been created
		940	(specifically, actions that happen "when the first watcher is created"
		941	happen when calling detetc as well).
919		942
920	If you need to do some initialisation before AnyEvent watchers are	943	If you need to do some initialisation before AnyEvent watchers are
921	created, use C<post_detect>.	944	created, use C<post_detect>.
922		945
923	=item $guard = AnyEvent::post_detect { BLOCK }	946	=item $guard = AnyEvent::post_detect { BLOCK }
924		947
925	Arranges for the code block to be executed as soon as the event model is	948	Arranges for the code block to be executed as soon as the event model is
926	autodetected (or immediately if this has already happened).	949	autodetected (or immediately if that has already happened).
927		950
928	The block will be executed I<after> the actual backend has been detected	951	The block will be executed I<after> the actual backend has been detected
929	(C<$AnyEvent::MODEL> is set), but I<before> any watchers have been	952	(C<$AnyEvent::MODEL> is set), but I<before> any watchers have been
930	created, so it is possible to e.g. patch C<@AnyEvent::ISA> or do	953	created, so it is possible to e.g. patch C<@AnyEvent::ISA> or do
931	other initialisations - see the sources of L<AnyEvent::Strict> or	954	other initialisations - see the sources of L<AnyEvent::Strict> or
…		…
940	that automatically removes the callback again when it is destroyed (or	963	that automatically removes the callback again when it is destroyed (or
941	C<undef> when the hook was immediately executed). See L<AnyEvent::AIO> for	964	C<undef> when the hook was immediately executed). See L<AnyEvent::AIO> for
942	a case where this is useful.	965	a case where this is useful.
943		966
944	Example: Create a watcher for the IO::AIO module and store it in	967	Example: Create a watcher for the IO::AIO module and store it in
945	C<$WATCHER>. Only do so after the event loop is initialised, though.	968	C<$WATCHER>, but do so only do so after the event loop is initialised.
946		969
947	our WATCHER;	970	our WATCHER;
948		971
949	my $guard = AnyEvent::post_detect {	972	my $guard = AnyEvent::post_detect {
950	$WATCHER = AnyEvent->io (fh => IO::AIO::poll_fileno, poll => 'r', cb => \&IO::AIO::poll_cb);	973	$WATCHER = AnyEvent->io (fh => IO::AIO::poll_fileno, poll => 'r', cb => \&IO::AIO::poll_cb);
…		…
958	$WATCHER ||= $guard;	981	$WATCHER ||= $guard;
959		982
960	=item @AnyEvent::post_detect	983	=item @AnyEvent::post_detect
961		984
962	If there are any code references in this array (you can C<push> to it	985	If there are any code references in this array (you can C<push> to it
963	before or after loading AnyEvent), then they will called directly after	986	before or after loading AnyEvent), then they will be called directly
964	the event loop has been chosen.	987	after the event loop has been chosen.
965		988
966	You should check C<$AnyEvent::MODEL> before adding to this array, though:	989	You should check C<$AnyEvent::MODEL> before adding to this array, though:
967	if it is defined then the event loop has already been detected, and the	990	if it is defined then the event loop has already been detected, and the
968	array will be ignored.	991	array will be ignored.
969		992
…		…
986	# AnyEvent not yet initialised, so make sure to load Coro::AnyEvent	1009	# AnyEvent not yet initialised, so make sure to load Coro::AnyEvent
987	# as soon as it is	1010	# as soon as it is
988	push @AnyEvent::post_detect, sub { require Coro::AnyEvent };	1011	push @AnyEvent::post_detect, sub { require Coro::AnyEvent };
989	}	1012	}
990		1013
		1014	=item AnyEvent::postpone { BLOCK }
		1015
		1016	Arranges for the block to be executed as soon as possible, but not before
		1017	the call itself returns. In practise, the block will be executed just
		1018	before the event loop polls for new events, or shortly afterwards.
		1019
		1020	This function never returns anything (to make the C<return postpone { ...
		1021	}> idiom more useful.
		1022
		1023	To understand the usefulness of this function, consider a function that
		1024	asynchronously does something for you and returns some transaction
		1025	object or guard to let you cancel the operation. For example,
		1026	C<AnyEvent::Socket::tcp_connect>:
		1027
		1028	# start a conenction attempt unless one is active
		1029	$self->{connect_guard} ||= AnyEvent::Socket::tcp_connect "www.example.net", 80, sub {
		1030	delete $self->{connect_guard};
		1031	...
		1032	};
		1033
		1034	Imagine that this function could instantly call the callback, for
		1035	example, because it detects an obvious error such as a negative port
		1036	number. Invoking the callback before the function returns causes problems
		1037	however: the callback will be called and will try to delete the guard
		1038	object. But since the function hasn't returned yet, there is nothing to
		1039	delete. When the function eventually returns it will assign the guard
		1040	object to C<< $self->{connect_guard} >>, where it will likely never be
		1041	deleted, so the program thinks it is still trying to connect.
		1042
		1043	This is where C<AnyEvent::postpone> should be used. Instead of calling the
		1044	callback directly on error:
		1045
		1046	$cb->(undef), return # signal error to callback, BAD!
		1047	if $some_error_condition;
		1048
		1049	It should use C<postpone>:
		1050
		1051	AnyEvent::postpone { $cb->(undef) }, return # signal error to callback, later
		1052	if $some_error_condition;
		1053
		1054	=item AnyEvent::log $level, $msg[, @args]
		1055
		1056	Log the given C<$msg> at the given C<$level>.
		1057
		1058	If L<AnyEvent::Log> is not loaded then this function makes a simple test
		1059	to see whether the message will be logged. If the test succeeds it will
		1060	load AnyEvent::Log and call C<AnyEvent::Log::log> - consequently, look at
		1061	the L<AnyEvent::Log> documentation for details.
		1062
		1063	If the test fails it will simply return.
		1064
		1065	If you want to sprinkle loads of logging calls around your code, consider
		1066	creating a logger callback with the C<AnyEvent::Log::logger> function,
		1067	which can reduce typing, codesize and can reduce the logging overhead
		1068	enourmously.
		1069
991	=back	1070	=back
992		1071
993	=head1 WHAT TO DO IN A MODULE	1072	=head1 WHAT TO DO IN A MODULE
994		1073
995	As a module author, you should C<use AnyEvent> and call AnyEvent methods	1074	As a module author, you should C<use AnyEvent> and call AnyEvent methods
…		…
1005	because it will stall the whole program, and the whole point of using	1084	because it will stall the whole program, and the whole point of using
1006	events is to stay interactive.	1085	events is to stay interactive.
1007		1086
1008	It is fine, however, to call C<< ->recv >> when the user of your module	1087	It is fine, however, to call C<< ->recv >> when the user of your module
1009	requests it (i.e. if you create a http request object ad have a method	1088	requests it (i.e. if you create a http request object ad have a method
1010	called C<results> that returns the results, it should call C<< ->recv >>	1089	called C<results> that returns the results, it may call C<< ->recv >>
1011	freely, as the user of your module knows what she is doing. always).	1090	freely, as the user of your module knows what she is doing. Always).
1012		1091
1013	=head1 WHAT TO DO IN THE MAIN PROGRAM	1092	=head1 WHAT TO DO IN THE MAIN PROGRAM
1014		1093
1015	There will always be a single main program - the only place that should	1094	There will always be a single main program - the only place that should
1016	dictate which event model to use.	1095	dictate which event model to use.
1017		1096
1018	If it doesn't care, it can just "use AnyEvent" and use it itself, or not	1097	If the program is not event-based, it need not do anything special, even
1019	do anything special (it does not need to be event-based) and let AnyEvent	1098	when it depends on a module that uses an AnyEvent. If the program itself
1020	decide which implementation to chose if some module relies on it.	1099	uses AnyEvent, but does not care which event loop is used, all it needs
		1100	to do is C<use AnyEvent>. In either case, AnyEvent will choose the best
		1101	available loop implementation.
1021		1102
1022	If the main program relies on a specific event model - for example, in	1103	If the main program relies on a specific event model - for example, in
1023	Gtk2 programs you have to rely on the Glib module - you should load the	1104	Gtk2 programs you have to rely on the Glib module - you should load the
1024	event module before loading AnyEvent or any module that uses it: generally	1105	event module before loading AnyEvent or any module that uses it: generally
1025	speaking, you should load it as early as possible. The reason is that	1106	speaking, you should load it as early as possible. The reason is that
1026	modules might create watchers when they are loaded, and AnyEvent will	1107	modules might create watchers when they are loaded, and AnyEvent will
1027	decide on the event model to use as soon as it creates watchers, and it	1108	decide on the event model to use as soon as it creates watchers, and it
1028	might chose the wrong one unless you load the correct one yourself.	1109	might choose the wrong one unless you load the correct one yourself.
1029		1110
1030	You can chose to use a pure-perl implementation by loading the	1111	You can chose to use a pure-perl implementation by loading the
1031	C<AnyEvent::Impl::Perl> module, which gives you similar behaviour	1112	C<AnyEvent::Loop> module, which gives you similar behaviour
1032	everywhere, but letting AnyEvent chose the model is generally better.	1113	everywhere, but letting AnyEvent chose the model is generally better.
1033		1114
1034	=head2 MAINLOOP EMULATION	1115	=head2 MAINLOOP EMULATION
1035		1116
1036	Sometimes (often for short test scripts, or even standalone programs who	1117	Sometimes (often for short test scripts, or even standalone programs who
…		…
1049		1130
1050		1131
1051	=head1 OTHER MODULES	1132	=head1 OTHER MODULES
1052		1133
1053	The following is a non-exhaustive list of additional modules that use	1134	The following is a non-exhaustive list of additional modules that use
1054	AnyEvent as a client and can therefore be mixed easily with other AnyEvent	1135	AnyEvent as a client and can therefore be mixed easily with other
1055	modules and other event loops in the same program. Some of the modules	1136	AnyEvent modules and other event loops in the same program. Some of the
1056	come with AnyEvent, most are available via CPAN.	1137	modules come as part of AnyEvent, the others are available via CPAN (see
		1138	L<http://search.cpan.org/search?m=module&q=anyevent%3A%3A*> for
		1139	a longer non-exhaustive list), and the list is heavily biased towards
		1140	modules of the AnyEvent author himself :)
1057		1141
1058	=over 4	1142	=over 4
1059		1143
1060	=item L<AnyEvent::Util>	1144	=item L<AnyEvent::Util>
1061		1145
1062	Contains various utility functions that replace often-used but blocking	1146	Contains various utility functions that replace often-used blocking
1063	functions such as C<inet_aton> by event-/callback-based versions.	1147	functions such as C<inet_aton> with event/callback-based versions.
1064		1148
1065	=item L<AnyEvent::Socket>	1149	=item L<AnyEvent::Socket>
1066		1150
1067	Provides various utility functions for (internet protocol) sockets,	1151	Provides various utility functions for (internet protocol) sockets,
1068	addresses and name resolution. Also functions to create non-blocking tcp	1152	addresses and name resolution. Also functions to create non-blocking tcp
…		…
1070		1154
1071	=item L<AnyEvent::Handle>	1155	=item L<AnyEvent::Handle>
1072		1156
1073	Provide read and write buffers, manages watchers for reads and writes,	1157	Provide read and write buffers, manages watchers for reads and writes,
1074	supports raw and formatted I/O, I/O queued and fully transparent and	1158	supports raw and formatted I/O, I/O queued and fully transparent and
1075	non-blocking SSL/TLS (via L<AnyEvent::TLS>.	1159	non-blocking SSL/TLS (via L<AnyEvent::TLS>).
1076		1160
1077	=item L<AnyEvent::DNS>	1161	=item L<AnyEvent::DNS>
1078		1162
1079	Provides rich asynchronous DNS resolver capabilities.	1163	Provides rich asynchronous DNS resolver capabilities.
1080		1164
		1165	=item L<AnyEvent::HTTP>, L<AnyEvent::IRC>, L<AnyEvent::XMPP>, L<AnyEvent::GPSD>, L<AnyEvent::IGS>, L<AnyEvent::FCP>
		1166
		1167	Implement event-based interfaces to the protocols of the same name (for
		1168	the curious, IGS is the International Go Server and FCP is the Freenet
		1169	Client Protocol).
		1170
1081	=item L<AnyEvent::HTTP>	1171	=item L<AnyEvent::AIO>
1082		1172
1083	A simple-to-use HTTP library that is capable of making a lot of concurrent	1173	Truly asynchronous (as opposed to non-blocking) I/O, should be in the
1084	HTTP requests.	1174	toolbox of every event programmer. AnyEvent::AIO transparently fuses
		1175	L<IO::AIO> and AnyEvent together, giving AnyEvent access to event-based
		1176	file I/O, and much more.
		1177
		1178	=item L<AnyEvent::Filesys::Notify>
		1179
		1180	AnyEvent is good for non-blocking stuff, but it can't detect file or
		1181	path changes (e.g. "watch this directory for new files", "watch this
		1182	file for changes"). The L<AnyEvent::Filesys::Notify> module promises to
		1183	do just that in a portbale fashion, supporting inotify on GNU/Linux and
		1184	some weird, without doubt broken, stuff on OS X to monitor files. It can
		1185	fall back to blocking scans at regular intervals transparently on other
		1186	platforms, so it's about as portable as it gets.
		1187
		1188	(I haven't used it myself, but I haven't heard anybody complaining about
		1189	it yet).
		1190
		1191	=item L<AnyEvent::DBI>
		1192
		1193	Executes L<DBI> requests asynchronously in a proxy process for you,
		1194	notifying you in an event-based way when the operation is finished.
1085		1195
1086	=item L<AnyEvent::HTTPD>	1196	=item L<AnyEvent::HTTPD>
1087		1197
1088	Provides a simple web application server framework.	1198	A simple embedded webserver.
1089		1199
1090	=item L<AnyEvent::FastPing>	1200	=item L<AnyEvent::FastPing>
1091		1201
1092	The fastest ping in the west.	1202	The fastest ping in the west.
1093		1203
1094	=item L<AnyEvent::DBI>
1095
1096	Executes L<DBI> requests asynchronously in a proxy process.
1097
1098	=item L<AnyEvent::AIO>
1099
1100	Truly asynchronous I/O, should be in the toolbox of every event
1101	programmer. AnyEvent::AIO transparently fuses L<IO::AIO> and AnyEvent
1102	together.
1103
1104	=item L<AnyEvent::BDB>
1105
1106	Truly asynchronous Berkeley DB access. AnyEvent::BDB transparently fuses
1107	L<BDB> and AnyEvent together.
1108
1109	=item L<AnyEvent::GPSD>
1110
1111	A non-blocking interface to gpsd, a daemon delivering GPS information.
1112
1113	=item L<AnyEvent::IRC>
1114
1115	AnyEvent based IRC client module family (replacing the older Net::IRC3).
1116
1117	=item L<AnyEvent::XMPP>
1118
1119	AnyEvent based XMPP (Jabber protocol) module family (replacing the older
1120	Net::XMPP2>.
1121
1122	=item L<AnyEvent::IGS>
1123
1124	A non-blocking interface to the Internet Go Server protocol (used by
1125	L<App::IGS>).
1126
1127	=item L<Net::FCP>
1128
1129	AnyEvent-based implementation of the Freenet Client Protocol, birthplace
1130	of AnyEvent.
1131
1132	=item L<Event::ExecFlow>
1133
1134	High level API for event-based execution flow control.
1135
1136	=item L<Coro>	1204	=item L<Coro>
1137		1205
1138	Has special support for AnyEvent via L<Coro::AnyEvent>.	1206	Has special support for AnyEvent via L<Coro::AnyEvent>, which allows you
		1207	to simply invert the flow control - don't call us, we will call you:
		1208
		1209	async {
		1210	Coro::AnyEvent::sleep 5; # creates a 5s timer and waits for it
		1211	print "5 seconds later!\n";
		1212
		1213	Coro::AnyEvent::readable *STDIN; # uses an I/O watcher
		1214	my $line = <STDIN>; # works for ttys
		1215
		1216	AnyEvent::HTTP::http_get "url", Coro::rouse_cb;
		1217	my ($body, $hdr) = Coro::rouse_wait;
		1218	};
1139		1219
1140	=back	1220	=back
1141		1221
1142	=cut	1222	=cut
1143		1223
1144	package AnyEvent;	1224	package AnyEvent;
1145		1225
1146	# basically a tuned-down version of common::sense	1226	# basically a tuned-down version of common::sense
1147	sub common_sense {	1227	sub common_sense {
1148	# from common:.sense 1.0	1228	# from common:.sense 3.4
1149	${^WARNING_BITS} = "\xfc\x3f\x33\x00\x0f\xf3\xcf\xc0\xf3\xfc\x33\x00";	1229	${^WARNING_BITS} ^= ${^WARNING_BITS} ^ "\x3c\x3f\x33\x00\x0f\xf0\x0f\xc0\xf0\xfc\x33\x00";
1150	# use strict vars subs - NO UTF-8, as Util.pm doesn't like this atm. (uts46data.pl)	1230	# use strict vars subs - NO UTF-8, as Util.pm doesn't like this atm. (uts46data.pl)
1151	$^H |= 0x00000600;	1231	$^H |= 0x00000600;
1152	}	1232	}
1153		1233
1154	BEGIN { AnyEvent::common_sense }	1234	BEGIN { AnyEvent::common_sense }
1155		1235
1156	use Carp ();	1236	use Carp ();
1157		1237
1158	our $VERSION = '5.22';	1238	our $VERSION = '6.02';
1159	our $MODEL;	1239	our $MODEL;
1160		1240
1161	our $AUTOLOAD;
1162	our @ISA;	1241	our @ISA;
1163		1242
1164	our @REGISTRY;	1243	our @REGISTRY;
1165		1244
1166	our $VERBOSE;	1245	our $VERBOSE;
1167		1246
1168	BEGIN {	1247	BEGIN {
1169	eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }";	1248	require "AnyEvent/constants.pl";
		1249
1170	eval "sub TAINT(){ " . (${^TAINT}*1) . " }";	1250	eval "sub TAINT (){" . (${^TAINT}*1) . "}";
1171		1251
1172	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}	1252	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}
1173	if ${^TAINT};	1253	if ${^TAINT};
1174		1254
		1255	$ENV{"PERL_ANYEVENT_$_"} = $ENV{"AE_$_"}
		1256	for grep s/^AE_// && !exists $ENV{"PERL_ANYEVENT_$_"}, keys %ENV;
		1257
		1258	@ENV{grep /^PERL_ANYEVENT_/, keys %ENV} = ()
		1259	if ${^TAINT};
		1260
1175	$VERBOSE = $ENV{PERL_ANYEVENT_VERBOSE}*1;	1261	$VERBOSE = $ENV{PERL_ANYEVENT_VERBOSE}*1;
1176
1177	}	1262	}
1178		1263
1179	our $MAX_SIGNAL_LATENCY = 10;	1264	our $MAX_SIGNAL_LATENCY = 10;
1180		1265
1181	our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred	1266	our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred
…		…
1185	$PROTOCOL{$_} = ++$idx	1270	$PROTOCOL{$_} = ++$idx
1186	for reverse split /\s*,\s*/,	1271	for reverse split /\s*,\s*/,
1187	$ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";	1272	$ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";
1188	}	1273	}
1189		1274
		1275	our @post_detect;
		1276
		1277	sub post_detect(&) {
		1278	my ($cb) = @_;
		1279
		1280	push @post_detect, $cb;
		1281
		1282	defined wantarray
		1283	? bless \$cb, "AnyEvent::Util::postdetect"
		1284	: ()
		1285	}
		1286
		1287	sub AnyEvent::Util::postdetect::DESTROY {
		1288	@post_detect = grep $_ != ${$_[0]}, @post_detect;
		1289	}
		1290
		1291	our $POSTPONE_W;
		1292	our @POSTPONE;
		1293
		1294	sub _postpone_exec {
		1295	undef $POSTPONE_W;
		1296
		1297	&{ shift @POSTPONE }
		1298	while @POSTPONE;
		1299	}
		1300
		1301	sub postpone(&) {
		1302	push @POSTPONE, shift;
		1303
		1304	$POSTPONE_W ||= AE::timer (0, 0, \&_postpone_exec);
		1305
		1306	()
		1307	}
		1308
		1309	sub log($$;@) {
		1310	# only load the big bloated module when we actually are about to log something
		1311	if ($_[0] <= $VERBOSE) { # also catches non-numeric levels(!)
		1312	require AnyEvent::Log;
		1313	# AnyEvent::Log overwrites this function
		1314	goto &log;
		1315	}
		1316
		1317	0 # not logged
		1318	}
		1319
		1320	if (length $ENV{PERL_ANYEVENT_LOG}) {
		1321	require AnyEvent::Log; # AnyEvent::Log does the thing for us
		1322	}
		1323
1190	my @models = (	1324	our @models = (
1191	[EV:: => AnyEvent::Impl::EV:: , 1],	1325	[EV:: => AnyEvent::Impl::EV:: , 1],
1192	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl:: , 1],	1326	[AnyEvent::Loop:: => AnyEvent::Impl::Perl:: , 1],
1193	# everything below here will not (normally) be autoprobed	1327	# everything below here will not (normally) be autoprobed
1194	# as the pureperl backend should work everywhere	1328	# as the pure perl backend should work everywhere
1195	# and is usually faster	1329	# and is usually faster
1196	[Event:: => AnyEvent::Impl::Event::, 1],	1330	[Event:: => AnyEvent::Impl::Event::, 1],
1197	[Glib:: => AnyEvent::Impl::Glib:: , 1], # becomes extremely slow with many watchers	1331	[Glib:: => AnyEvent::Impl::Glib:: , 1], # becomes extremely slow with many watchers
1198	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy	1332	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
1199	[Irssi:: => AnyEvent::Impl::Irssi::], # Irssi has a bogus "Event" package	1333	[Irssi:: => AnyEvent::Impl::Irssi::], # Irssi has a bogus "Event" package
1200	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles	1334	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
1201	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program	1335	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program
1202	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza	1336	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
1203	[Wx:: => AnyEvent::Impl::POE::],	1337	[Wx:: => AnyEvent::Impl::POE::],
1204	[Prima:: => AnyEvent::Impl::POE::],	1338	[Prima:: => AnyEvent::Impl::POE::],
1205	# IO::Async is just too broken - we would need workarounds for its	1339	[IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # a bitch to autodetect
1206	# byzantine signal and broken child handling, among others.	1340	[Cocoa::EventLoop:: => AnyEvent::Impl::Cocoa::],
1207	# IO::Async is rather hard to detect, as it doesn't have any	1341	[FLTK:: => AnyEvent::Impl::FLTK::],
1208	# obvious default class.
1209	[IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program
1210	[IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program
1211	[IO::Async::Notifier:: => AnyEvent::Impl::IOAsync::], # requires special main program
1212	[AnyEvent::Impl::IOAsync:: => AnyEvent::Impl::IOAsync::], # requires special main program
1213	);	1342	);
1214		1343
1215	our %method = map +($_ => 1),	1344	our @isa_hook;
		1345
		1346	sub _isa_set {
		1347	my @pkg = ("AnyEvent", (map $_->[0], grep defined, @isa_hook), $MODEL);
		1348
		1349	@{"$pkg[$_-1]::ISA"} = $pkg[$_]
		1350	for 1 .. $#pkg;
		1351
		1352	grep $_ && $_->[1], @isa_hook
		1353	and AE::_reset ();
		1354	}
		1355
		1356	# used for hooking AnyEvent::Strict and AnyEvent::Debug::Wrap into the class hierarchy
		1357	sub _isa_hook($$;$) {
		1358	my ($i, $pkg, $reset_ae) = @_;
		1359
		1360	$isa_hook[$i] = $pkg ? [$pkg, $reset_ae] : undef;
		1361
		1362	_isa_set;
		1363	}
		1364
		1365	# all autoloaded methods reserve the complete glob, not just the method slot.
		1366	# due to bugs in perls method cache implementation.
1216	qw(io timer time now now_update signal child idle condvar one_event DESTROY);	1367	our @methods = qw(io timer time now now_update signal child idle condvar);
1217		1368
1218	our @post_detect;
1219
1220	sub post_detect(&) {	1369	sub detect() {
1221	my ($cb) = @_;	1370	return $MODEL if $MODEL; # some programs keep references to detect
1222		1371
1223	if ($MODEL) {	1372	local $!; # for good measure
1224	$cb->();	1373	local $SIG{__DIE__}; # we use eval
1225		1374
1226	undef	1375	# free some memory
		1376	*detect = sub () { $MODEL };
		1377	# undef &func doesn't correctly update the method cache. grmbl.
		1378	# so we delete the whole glob. grmbl.
		1379	# otoh, perl doesn't let me undef an active usb, but it lets me free
		1380	# a glob with an active sub. hrm. i hope it works, but perl is
		1381	# usually buggy in this department. sigh.
		1382	delete @{"AnyEvent::"}{@methods};
		1383	undef @methods;
		1384
		1385	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z0-9:]+)$/) {
		1386	my $model = $1;
		1387	$model = "AnyEvent::Impl::$model" unless $model =~ s/::$//;
		1388	if (eval "require $model") {
		1389	AnyEvent::log 7 => "loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.";
		1390	$MODEL = $model;
1227	} else {	1391	} else {
1228	push @post_detect, $cb;	1392	AnyEvent::log 5 => "unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@";
1229		1393	}
1230	defined wantarray
1231	? bless \$cb, "AnyEvent::Util::postdetect"
1232	: ()
1233	}	1394	}
1234	}
1235		1395
1236	sub AnyEvent::Util::postdetect::DESTROY {	1396	# check for already loaded models
1237	@post_detect = grep $_ != ${$_[0]}, @post_detect;
1238	}
1239
1240	sub detect() {
1241	unless ($MODEL) {	1397	unless ($MODEL) {
1242	local $SIG{__DIE__};	1398	for (@REGISTRY, @models) {
1243		1399	my ($package, $model) = @$_;
1244	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {	1400	if (${"$package\::VERSION"} > 0) {
1245	my $model = "AnyEvent::Impl::$1";
1246	if (eval "require $model") {	1401	if (eval "require $model") {
		1402	AnyEvent::log 7 => "autodetected model '$model', using it.";
1247	$MODEL = $model;	1403	$MODEL = $model;
1248	warn "AnyEvent: loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.\n" if $VERBOSE >= 2;	1404	last;
1249	} else {	1405	}
1250	warn "AnyEvent: unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@" if $VERBOSE;
1251	}	1406	}
1252	}	1407	}
1253		1408
1254	# check for already loaded models
1255	unless ($MODEL) {	1409	unless ($MODEL) {
		1410	# try to autoload a model
1256	for (@REGISTRY, @models) {	1411	for (@REGISTRY, @models) {
1257	my ($package, $model) = @$_;	1412	my ($package, $model, $autoload) = @$_;
		1413	if (
		1414	$autoload
		1415	and eval "require $package"
1258	if (${"$package\::VERSION"} > 0) {	1416	and ${"$package\::VERSION"} > 0
1259	if (eval "require $model") {	1417	and eval "require $model"
		1418	) {
		1419	AnyEvent::log 7 => "autoloaded model '$model', using it.";
1260	$MODEL = $model;	1420	$MODEL = $model;
1261	warn "AnyEvent: autodetected model '$model', using it.\n" if $VERBOSE >= 2;
1262	last;	1421	last;
1263	}
1264	}	1422	}
1265	}	1423	}
1266		1424
1267	unless ($MODEL) {
1268	# try to autoload a model
1269	for (@REGISTRY, @models) {
1270	my ($package, $model, $autoload) = @$_;
1271	if (
1272	$autoload
1273	and eval "require $package"
1274	and ${"$package\::VERSION"} > 0
1275	and eval "require $model"
1276	) {
1277	$MODEL = $model;
1278	warn "AnyEvent: autoloaded model '$model', using it.\n" if $VERBOSE >= 2;
1279	last;
1280	}
1281	}
1282
1283	$MODEL	1425	$MODEL
1284	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.\n";	1426	or die "AnyEvent: backend autodetection failed - did you properly install AnyEvent?";
1285	}
1286	}	1427	}
1287
1288	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
1289
1290	unshift @ISA, $MODEL;
1291
1292	require AnyEvent::Strict if $ENV{PERL_ANYEVENT_STRICT};
1293
1294	(shift @post_detect)->() while @post_detect;
1295	}	1428	}
1296		1429
		1430	# free memory only needed for probing
		1431	undef @models;
		1432	undef @REGISTRY;
		1433
		1434	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
		1435
		1436	# now nuke some methods that are overridden by the backend.
		1437	# SUPER usage is not allowed in these.
		1438	for (qw(time signal child idle)) {
		1439	undef &{"AnyEvent::Base::$_"}
		1440	if defined &{"$MODEL\::$_"};
		1441	}
		1442
		1443	_isa_set;
		1444
		1445	# we're officially open!
		1446
		1447	if ($ENV{PERL_ANYEVENT_STRICT}) {
		1448	require AnyEvent::Strict;
		1449	}
		1450
		1451	if ($ENV{PERL_ANYEVENT_DEBUG_WRAP}) {
		1452	require AnyEvent::Debug;
		1453	AnyEvent::Debug::wrap ($ENV{PERL_ANYEVENT_DEBUG_WRAP});
		1454	}
		1455
		1456	if (length $ENV{PERL_ANYEVENT_DEBUG_SHELL}) {
		1457	require AnyEvent::Socket;
		1458	require AnyEvent::Debug;
		1459
		1460	my $shell = $ENV{PERL_ANYEVENT_DEBUG_SHELL};
		1461	$shell =~ s/\$\$/$$/g;
		1462
		1463	my ($host, $service) = AnyEvent::Socket::parse_hostport ($shell);
		1464	$AnyEvent::Debug::SHELL = AnyEvent::Debug::shell ($host, $service);
		1465	}
		1466
		1467	# now the anyevent environment is set up as the user told us to, so
		1468	# call the actual user code - post detects
		1469
		1470	(shift @post_detect)->() while @post_detect;
		1471	undef @post_detect;
		1472
		1473	*post_detect = sub(&) {
		1474	shift->();
		1475
		1476	undef
		1477	};
		1478
1297	$MODEL	1479	$MODEL
1298	}	1480	}
1299		1481
1300	sub AUTOLOAD {	1482	for my $name (@methods) {
1301	(my $func = $AUTOLOAD) =~ s/.*://;	1483	*$name = sub {
1302		1484	detect;
1303	$method{$func}	1485	# we use goto because
1304	or Carp::croak "$func: not a valid method for AnyEvent objects";	1486	# a) it makes the thunk more transparent
1305		1487	# b) it allows us to delete the thunk later
1306	detect unless $MODEL;	1488	goto &{ UNIVERSAL::can AnyEvent => "SUPER::$name" }
1307		1489	};
1308	my $class = shift;
1309	$class->$func (@_);
1310	}	1490	}
1311		1491
1312	# utility function to dup a filehandle. this is used by many backends	1492	# utility function to dup a filehandle. this is used by many backends
1313	# to support binding more than one watcher per filehandle (they usually	1493	# to support binding more than one watcher per filehandle (they usually
1314	# allow only one watcher per fd, so we dup it to get a different one).	1494	# allow only one watcher per fd, so we dup it to get a different one).
…		…
1328		1508
1329	=head1 SIMPLIFIED AE API	1509	=head1 SIMPLIFIED AE API
1330		1510
1331	Starting with version 5.0, AnyEvent officially supports a second, much	1511	Starting with version 5.0, AnyEvent officially supports a second, much
1332	simpler, API that is designed to reduce the calling, typing and memory	1512	simpler, API that is designed to reduce the calling, typing and memory
1333	overhead.	1513	overhead by using function call syntax and a fixed number of parameters.
1334		1514
1335	See the L<AE> manpage for details.	1515	See the L<AE> manpage for details.
1336		1516
1337	=cut	1517	=cut
1338		1518
1339	package AE;	1519	package AE;
1340		1520
1341	our $VERSION = $AnyEvent::VERSION;	1521	our $VERSION = $AnyEvent::VERSION;
1342		1522
		1523	sub _reset() {
		1524	eval q{
		1525	# fall back to the main API by default - backends and AnyEvent::Base
		1526	# implementations can overwrite these.
		1527
1343	sub io($$$) {	1528	sub io($$$) {
1344	AnyEvent->io (fh => $_[0], poll => $_[1] ? "w" : "r", cb => $_[2])	1529	AnyEvent->io (fh => $_[0], poll => $_[1] ? "w" : "r", cb => $_[2])
1345	}	1530	}
1346		1531
1347	sub timer($$$) {	1532	sub timer($$$) {
1348	AnyEvent->timer (after => $_[0], interval => $_[1], cb => $_[2])	1533	AnyEvent->timer (after => $_[0], interval => $_[1], cb => $_[2])
1349	}	1534	}
1350		1535
1351	sub signal($$) {	1536	sub signal($$) {
1352	AnyEvent->signal (signal => $_[0], cb => $_[1])	1537	AnyEvent->signal (signal => $_[0], cb => $_[1])
1353	}	1538	}
1354		1539
1355	sub child($$) {	1540	sub child($$) {
1356	AnyEvent->child (pid => $_[0], cb => $_[1])	1541	AnyEvent->child (pid => $_[0], cb => $_[1])
1357	}	1542	}
1358		1543
1359	sub idle($) {	1544	sub idle($) {
1360	AnyEvent->idle (cb => $_[0])	1545	AnyEvent->idle (cb => $_[0]);
1361	}	1546	}
1362		1547
1363	sub cv(;&) {	1548	sub cv(;&) {
1364	AnyEvent->condvar (@_ ? (cb => $_[0]) : ())	1549	AnyEvent->condvar (@_ ? (cb => $_[0]) : ())
1365	}	1550	}
1366		1551
1367	sub now() {	1552	sub now() {
1368	AnyEvent->now	1553	AnyEvent->now
1369	}	1554	}
1370		1555
1371	sub now_update() {	1556	sub now_update() {
1372	AnyEvent->now_update	1557	AnyEvent->now_update
1373	}	1558	}
1374		1559
1375	sub time() {	1560	sub time() {
1376	AnyEvent->time	1561	AnyEvent->time
		1562	}
		1563
		1564	*postpone = \&AnyEvent::postpone;
		1565	*log = \&AnyEvent::log;
		1566	};
		1567	die if $@;
1377	}	1568	}
		1569
		1570	BEGIN { _reset }
1378		1571
1379	package AnyEvent::Base;	1572	package AnyEvent::Base;
1380		1573
1381	# default implementations for many methods	1574	# default implementations for many methods
1382		1575
1383	sub _time() {	1576	sub time {
		1577	eval q{ # poor man's autoloading {}
1384	# probe for availability of Time::HiRes	1578	# probe for availability of Time::HiRes
1385	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {	1579	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {
1386	warn "AnyEvent: using Time::HiRes for sub-second timing accuracy.\n" if $VERBOSE >= 8;	1580	*time = sub { Time::HiRes::time () };
1387	*_time = \&Time::HiRes::time;	1581	*AE::time = \& Time::HiRes::time ;
		1582	*now = \&time;
		1583	AnyEvent::log 8 => "AnyEvent: using Time::HiRes for sub-second timing accuracy.";
1388	# if (eval "use POSIX (); (POSIX::times())...	1584	# if (eval "use POSIX (); (POSIX::times())...
1389	} else {	1585	} else {
		1586	*time = sub { CORE::time };
		1587	*AE::time = sub (){ CORE::time };
		1588	*now = \&time;
1390	warn "AnyEvent: using built-in time(), WARNING, no sub-second resolution!\n" if $VERBOSE;	1589	AnyEvent::log 3 => "using built-in time(), WARNING, no sub-second resolution!";
1391	*_time = sub { time }; # epic fail	1590	}
1392	}	1591	};
		1592	die if $@;
1393		1593
1394	&_time	1594	&time
1395	}	1595	}
1396		1596
1397	sub time { _time }	1597	*now = \&time;
1398	sub now { _time }
1399	sub now_update { }	1598	sub now_update { }
1400		1599
		1600	sub _poll {
		1601	Carp::croak "$AnyEvent::MODEL does not support blocking waits. Caught";
		1602	}
		1603
1401	# default implementation for ->condvar	1604	# default implementation for ->condvar
		1605	# in fact, the default should not be overwritten
1402		1606
1403	sub condvar {	1607	sub condvar {
		1608	eval q{ # poor man's autoloading {}
		1609	*condvar = sub {
1404	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"	1610	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"
		1611	};
		1612
		1613	*AE::cv = sub (;&) {
		1614	bless { @_ ? (_ae_cb => shift) : () }, "AnyEvent::CondVar"
		1615	};
		1616	};
		1617	die if $@;
		1618
		1619	&condvar
1405	}	1620	}
1406		1621
1407	# default implementation for ->signal	1622	# default implementation for ->signal
1408		1623
1409	our $HAVE_ASYNC_INTERRUPT;	1624	our $HAVE_ASYNC_INTERRUPT;
…		…
1418		1633
1419	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);	1634	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);
1420	our (%SIG_ASY, %SIG_ASY_W);	1635	our (%SIG_ASY, %SIG_ASY_W);
1421	our ($SIG_COUNT, $SIG_TW);	1636	our ($SIG_COUNT, $SIG_TW);
1422		1637
1423	sub _signal_exec {
1424	$HAVE_ASYNC_INTERRUPT
1425	? $SIGPIPE_R->drain
1426	: sysread $SIGPIPE_R, (my $dummy), 9;
1427
1428	while (%SIG_EV) {
1429	for (keys %SIG_EV) {
1430	delete $SIG_EV{$_};
1431	$_->() for values %{ $SIG_CB{$_} || {} };
1432	}
1433	}
1434	}
1435
1436	# install a dummy wakeup watcher to reduce signal catching latency	1638	# install a dummy wakeup watcher to reduce signal catching latency
		1639	# used by Impls
1437	sub _sig_add() {	1640	sub _sig_add() {
1438	unless ($SIG_COUNT++) {	1641	unless ($SIG_COUNT++) {
1439	# try to align timer on a full-second boundary, if possible	1642	# try to align timer on a full-second boundary, if possible
1440	my $NOW = AE::now;	1643	my $NOW = AE::now;
1441		1644
…		…
1451	undef $SIG_TW	1654	undef $SIG_TW
1452	unless --$SIG_COUNT;	1655	unless --$SIG_COUNT;
1453	}	1656	}
1454		1657
1455	our $_sig_name_init; $_sig_name_init = sub {	1658	our $_sig_name_init; $_sig_name_init = sub {
1456	eval q{ # poor man's autoloading	1659	eval q{ # poor man's autoloading {}
1457	undef $_sig_name_init;	1660	undef $_sig_name_init;
1458		1661
1459	if (_have_async_interrupt) {	1662	if (_have_async_interrupt) {
1460	*sig2num = \&Async::Interrupt::sig2num;	1663	*sig2num = \&Async::Interrupt::sig2num;
1461	*sig2name = \&Async::Interrupt::sig2name;	1664	*sig2name = \&Async::Interrupt::sig2name;
…		…
1485		1688
1486	sub signal {	1689	sub signal {
1487	eval q{ # poor man's autoloading {}	1690	eval q{ # poor man's autoloading {}
1488	# probe for availability of Async::Interrupt	1691	# probe for availability of Async::Interrupt
1489	if (_have_async_interrupt) {	1692	if (_have_async_interrupt) {
1490	warn "AnyEvent: using Async::Interrupt for race-free signal handling.\n" if $VERBOSE >= 8;	1693	AnyEvent::log 8 => "using Async::Interrupt for race-free signal handling.";
1491		1694
1492	$SIGPIPE_R = new Async::Interrupt::EventPipe;	1695	$SIGPIPE_R = new Async::Interrupt::EventPipe;
1493	$SIG_IO = AE::io $SIGPIPE_R->fileno, 0, \&_signal_exec;	1696	$SIG_IO = AE::io $SIGPIPE_R->fileno, 0, \&_signal_exec;
1494		1697
1495	} else {	1698	} else {
1496	warn "AnyEvent: using emulated perl signal handling with latency timer.\n" if $VERBOSE >= 8;	1699	AnyEvent::log 8 => "using emulated perl signal handling with latency timer.";
1497
1498	require Fcntl;
1499		1700
1500	if (AnyEvent::WIN32) {	1701	if (AnyEvent::WIN32) {
1501	require AnyEvent::Util;	1702	require AnyEvent::Util;
1502		1703
1503	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();	1704	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
1504	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R, 1) if $SIGPIPE_R;	1705	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R, 1) if $SIGPIPE_R;
1505	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W, 1) if $SIGPIPE_W; # just in case	1706	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W, 1) if $SIGPIPE_W; # just in case
1506	} else {	1707	} else {
1507	pipe $SIGPIPE_R, $SIGPIPE_W;	1708	pipe $SIGPIPE_R, $SIGPIPE_W;
1508	fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R;	1709	fcntl $SIGPIPE_R, AnyEvent::F_SETFL, AnyEvent::O_NONBLOCK if $SIGPIPE_R;
1509	fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case	1710	fcntl $SIGPIPE_W, AnyEvent::F_SETFL, AnyEvent::O_NONBLOCK if $SIGPIPE_W; # just in case
1510		1711
1511	# not strictly required, as $^F is normally 2, but let's make sure...	1712	# not strictly required, as $^F is normally 2, but let's make sure...
1512	fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;	1713	fcntl $SIGPIPE_R, AnyEvent::F_SETFD, AnyEvent::FD_CLOEXEC;
1513	fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;	1714	fcntl $SIGPIPE_W, AnyEvent::F_SETFD, AnyEvent::FD_CLOEXEC;
1514	}	1715	}
1515		1716
1516	$SIGPIPE_R	1717	$SIGPIPE_R
1517	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";	1718	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";
1518		1719
1519	$SIG_IO = AE::io $SIGPIPE_R, 0, \&_signal_exec;	1720	$SIG_IO = AE::io $SIGPIPE_R, 0, \&_signal_exec;
1520	}	1721	}
1521		1722
1522	*signal = sub {	1723	*signal = $HAVE_ASYNC_INTERRUPT
		1724	? sub {
1523	my (undef, %arg) = @_;	1725	my (undef, %arg) = @_;
1524		1726
1525	my $signal = uc $arg{signal}
1526	or Carp::croak "required option 'signal' is missing";
1527
1528	if ($HAVE_ASYNC_INTERRUPT) {
1529	# async::interrupt	1727	# async::interrupt
1530
1531	$signal = sig2num $signal;	1728	my $signal = sig2num $arg{signal};
1532	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};	1729	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
1533		1730
1534	$SIG_ASY{$signal} ||= new Async::Interrupt	1731	$SIG_ASY{$signal} ||= new Async::Interrupt
1535	cb => sub { undef $SIG_EV{$signal} },	1732	cb => sub { undef $SIG_EV{$signal} },
1536	signal => $signal,	1733	signal => $signal,
1537	pipe => [$SIGPIPE_R->filenos],	1734	pipe => [$SIGPIPE_R->filenos],
1538	pipe_autodrain => 0,	1735	pipe_autodrain => 0,
1539	;	1736	;
1540		1737
1541	} else {	1738	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
		1739	}
		1740	: sub {
		1741	my (undef, %arg) = @_;
		1742
1542	# pure perl	1743	# pure perl
1543
1544	# AE::Util has been loaded in signal
1545	$signal = sig2name $signal;	1744	my $signal = sig2name $arg{signal};
1546	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};	1745	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
1547		1746
1548	$SIG{$signal} ||= sub {	1747	$SIG{$signal} ||= sub {
1549	local $!;	1748	local $!;
1550	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;	1749	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;
1551	undef $SIG_EV{$signal};	1750	undef $SIG_EV{$signal};
1552	};	1751	};
1553		1752
1554	# can't do signal processing without introducing races in pure perl,	1753	# can't do signal processing without introducing races in pure perl,
1555	# so limit the signal latency.	1754	# so limit the signal latency.
1556	_sig_add;	1755	_sig_add;
1557	}
1558		1756
1559	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"	1757	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
		1758	}
1560	};	1759	;
1561		1760
1562	*AnyEvent::Base::signal::DESTROY = sub {	1761	*AnyEvent::Base::signal::DESTROY = sub {
1563	my ($signal, $cb) = @{$_[0]};	1762	my ($signal, $cb) = @{$_[0]};
1564		1763
1565	_sig_del;	1764	_sig_del;
…		…
1572	# print weird messages, or just unconditionally exit	1771	# print weird messages, or just unconditionally exit
1573	# instead of getting the default action.	1772	# instead of getting the default action.
1574	undef $SIG{$signal}	1773	undef $SIG{$signal}
1575	unless keys %{ $SIG_CB{$signal} };	1774	unless keys %{ $SIG_CB{$signal} };
1576	};	1775	};
		1776
		1777	*_signal_exec = sub {
		1778	$HAVE_ASYNC_INTERRUPT
		1779	? $SIGPIPE_R->drain
		1780	: sysread $SIGPIPE_R, (my $dummy), 9;
		1781
		1782	while (%SIG_EV) {
		1783	for (keys %SIG_EV) {
		1784	delete $SIG_EV{$_};
		1785	&$_ for values %{ $SIG_CB{$_} || {} };
		1786	}
		1787	}
		1788	};
1577	};	1789	};
1578	die if $@;	1790	die if $@;
		1791
1579	&signal	1792	&signal
1580	}	1793	}
1581		1794
1582	# default implementation for ->child	1795	# default implementation for ->child
1583		1796
1584	our %PID_CB;	1797	our %PID_CB;
1585	our $CHLD_W;	1798	our $CHLD_W;
1586	our $CHLD_DELAY_W;	1799	our $CHLD_DELAY_W;
1587	our $WNOHANG;
1588		1800
		1801	# used by many Impl's
1589	sub _emit_childstatus($$) {	1802	sub _emit_childstatus($$) {
1590	my (undef, $rpid, $rstatus) = @_;	1803	my (undef, $rpid, $rstatus) = @_;
1591		1804
1592	$_->($rpid, $rstatus)	1805	$_->($rpid, $rstatus)
1593	for values %{ $PID_CB{$rpid} || {} },	1806	for values %{ $PID_CB{$rpid} || {} },
1594	values %{ $PID_CB{0} || {} };	1807	values %{ $PID_CB{0} || {} };
1595	}	1808	}
1596		1809
1597	sub _sigchld {
1598	my $pid;
1599
1600	AnyEvent->_emit_childstatus ($pid, $?)
1601	while ($pid = waitpid -1, $WNOHANG) > 0;
1602	}
1603
1604	sub child {	1810	sub child {
		1811	eval q{ # poor man's autoloading {}
		1812	*_sigchld = sub {
		1813	my $pid;
		1814
		1815	AnyEvent->_emit_childstatus ($pid, $?)
		1816	while ($pid = waitpid -1, WNOHANG) > 0;
		1817	};
		1818
		1819	*child = sub {
1605	my (undef, %arg) = @_;	1820	my (undef, %arg) = @_;
1606		1821
1607	defined (my $pid = $arg{pid} + 0)	1822	my $pid = $arg{pid};
1608	or Carp::croak "required option 'pid' is missing";	1823	my $cb = $arg{cb};
1609		1824
1610	$PID_CB{$pid}{$arg{cb}} = $arg{cb};	1825	$PID_CB{$pid}{$cb+0} = $cb;
1611		1826
1612	# WNOHANG is almost cetrainly 1 everywhere
1613	$WNOHANG ||= $^O =~ /^(?:openbsd|netbsd|linux|freebsd|cygwin|MSWin32)$/
1614	? 1
1615	: eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1;
1616
1617	unless ($CHLD_W) {	1827	unless ($CHLD_W) {
1618	$CHLD_W = AE::signal CHLD => \&_sigchld;	1828	$CHLD_W = AE::signal CHLD => \&_sigchld;
1619	# child could be a zombie already, so make at least one round	1829	# child could be a zombie already, so make at least one round
1620	&_sigchld;	1830	&_sigchld;
1621	}	1831	}
1622		1832
1623	bless [$pid, $arg{cb}], "AnyEvent::Base::child"	1833	bless [$pid, $cb+0], "AnyEvent::Base::child"
1624	}	1834	};
1625		1835
1626	sub AnyEvent::Base::child::DESTROY {	1836	*AnyEvent::Base::child::DESTROY = sub {
1627	my ($pid, $cb) = @{$_[0]};	1837	my ($pid, $icb) = @{$_[0]};
1628		1838
1629	delete $PID_CB{$pid}{$cb};	1839	delete $PID_CB{$pid}{$icb};
1630	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };	1840	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };
1631		1841
1632	undef $CHLD_W unless keys %PID_CB;	1842	undef $CHLD_W unless keys %PID_CB;
		1843	};
		1844	};
		1845	die if $@;
		1846
		1847	&child
1633	}	1848	}
1634		1849
1635	# idle emulation is done by simply using a timer, regardless	1850	# idle emulation is done by simply using a timer, regardless
1636	# of whether the process is idle or not, and not letting	1851	# of whether the process is idle or not, and not letting
1637	# the callback use more than 50% of the time.	1852	# the callback use more than 50% of the time.
1638	sub idle {	1853	sub idle {
		1854	eval q{ # poor man's autoloading {}
		1855	*idle = sub {
1639	my (undef, %arg) = @_;	1856	my (undef, %arg) = @_;
1640		1857
1641	my ($cb, $w, $rcb) = $arg{cb};	1858	my ($cb, $w, $rcb) = $arg{cb};
1642		1859
1643	$rcb = sub {	1860	$rcb = sub {
1644	if ($cb) {	1861	if ($cb) {
1645	$w = _time;	1862	$w = AE::time;
1646	&$cb;	1863	&$cb;
1647	$w = _time - $w;	1864	$w = AE::time - $w;
1648		1865
1649	# never use more then 50% of the time for the idle watcher,	1866	# never use more then 50% of the time for the idle watcher,
1650	# within some limits	1867	# within some limits
1651	$w = 0.0001 if $w < 0.0001;	1868	$w = 0.0001 if $w < 0.0001;
1652	$w = 5 if $w > 5;	1869	$w = 5 if $w > 5;
1653		1870
1654	$w = AE::timer $w, 0, $rcb;	1871	$w = AE::timer $w, 0, $rcb;
1655	} else {	1872	} else {
1656	# clean up...	1873	# clean up...
1657	undef $w;	1874	undef $w;
1658	undef $rcb;	1875	undef $rcb;
		1876	}
		1877	};
		1878
		1879	$w = AE::timer 0.05, 0, $rcb;
		1880
		1881	bless \\$cb, "AnyEvent::Base::idle"
1659	}	1882	};
		1883
		1884	*AnyEvent::Base::idle::DESTROY = sub {
		1885	undef $${$_[0]};
		1886	};
1660	};	1887	};
		1888	die if $@;
1661		1889
1662	$w = AE::timer 0.05, 0, $rcb;	1890	&idle
1663
1664	bless \\$cb, "AnyEvent::Base::idle"
1665	}
1666
1667	sub AnyEvent::Base::idle::DESTROY {
1668	undef $${$_[0]};
1669	}	1891	}
1670		1892
1671	package AnyEvent::CondVar;	1893	package AnyEvent::CondVar;
1672		1894
1673	our @ISA = AnyEvent::CondVar::Base::;	1895	our @ISA = AnyEvent::CondVar::Base::;
		1896
		1897	# only to be used for subclassing
		1898	sub new {
		1899	my $class = shift;
		1900	bless AnyEvent->condvar (@_), $class
		1901	}
1674		1902
1675	package AnyEvent::CondVar::Base;	1903	package AnyEvent::CondVar::Base;
1676		1904
1677	#use overload	1905	#use overload
1678	# '&{}' => sub { my $self = shift; sub { $self->send (@_) } },	1906	# '&{}' => sub { my $self = shift; sub { $self->send (@_) } },
…		…
1688		1916
1689	sub _send {	1917	sub _send {
1690	# nop	1918	# nop
1691	}	1919	}
1692		1920
		1921	sub _wait {
		1922	AnyEvent->_poll until $_[0]{_ae_sent};
		1923	}
		1924
1693	sub send {	1925	sub send {
1694	my $cv = shift;	1926	my $cv = shift;
1695	$cv->{_ae_sent} = [@_];	1927	$cv->{_ae_sent} = [@_];
1696	(delete $cv->{_ae_cb})->($cv) if $cv->{_ae_cb};	1928	(delete $cv->{_ae_cb})->($cv) if $cv->{_ae_cb};
1697	$cv->_send;	1929	$cv->_send;
…		…
1704		1936
1705	sub ready {	1937	sub ready {
1706	$_[0]{_ae_sent}	1938	$_[0]{_ae_sent}
1707	}	1939	}
1708		1940
1709	sub _wait {
1710	$WAITING
1711	and !$_[0]{_ae_sent}
1712	and Carp::croak "AnyEvent::CondVar: recursive blocking wait detected";
1713
1714	local $WAITING = 1;
1715	AnyEvent->one_event while !$_[0]{_ae_sent};
1716	}
1717
1718	sub recv {	1941	sub recv {
		1942	unless ($_[0]{_ae_sent}) {
		1943	$WAITING
		1944	and Carp::croak "AnyEvent::CondVar: recursive blocking wait attempted";
		1945
		1946	local $WAITING = 1;
1719	$_[0]->_wait;	1947	$_[0]->_wait;
		1948	}
1720		1949
1721	Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak};	1950	$_[0]{_ae_croak}
1722	wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0]	1951	and Carp::croak $_[0]{_ae_croak};
		1952
		1953	wantarray
		1954	? @{ $_[0]{_ae_sent} }
		1955	: $_[0]{_ae_sent}[0]
1723	}	1956	}
1724		1957
1725	sub cb {	1958	sub cb {
1726	my $cv = shift;	1959	my $cv = shift;
1727		1960
…		…
1743	&{ $_[0]{_ae_end_cb} || sub { $_[0]->send } };	1976	&{ $_[0]{_ae_end_cb} || sub { $_[0]->send } };
1744	}	1977	}
1745		1978
1746	# undocumented/compatibility with pre-3.4	1979	# undocumented/compatibility with pre-3.4
1747	*broadcast = \&send;	1980	*broadcast = \&send;
1748	*wait = \&_wait;	1981	*wait = \&recv;
1749		1982
1750	=head1 ERROR AND EXCEPTION HANDLING	1983	=head1 ERROR AND EXCEPTION HANDLING
1751		1984
1752	In general, AnyEvent does not do any error handling - it relies on the	1985	In general, AnyEvent does not do any error handling - it relies on the
1753	caller to do that if required. The L<AnyEvent::Strict> module (see also	1986	caller to do that if required. The L<AnyEvent::Strict> module (see also
…		…
1765	$Event/EV::DIED->() >>, L<Glib> uses C<< install_exception_handler >> and	1998	$Event/EV::DIED->() >>, L<Glib> uses C<< install_exception_handler >> and
1766	so on.	1999	so on.
1767		2000
1768	=head1 ENVIRONMENT VARIABLES	2001	=head1 ENVIRONMENT VARIABLES
1769		2002
1770	The following environment variables are used by this module or its	2003	AnyEvent supports a number of environment variables that tune the
1771	submodules.	2004	runtime behaviour. They are usually evaluated when AnyEvent is
		2005	loaded, initialised, or a submodule that uses them is loaded. Many of
		2006	them also cause AnyEvent to load additional modules - for example,
		2007	C<PERL_ANYEVENT_DEBUG_WRAP> causes the L<AnyEvent::Debug> module to be
		2008	loaded.
1772		2009
1773	Note that AnyEvent will remove I<all> environment variables starting with	2010	All the environment variables documented here start with
1774	C<PERL_ANYEVENT_> from C<%ENV> when it is loaded while taint mode is	2011	C<PERL_ANYEVENT_>, which is what AnyEvent considers its own
1775	enabled.	2012	namespace. Other modules are encouraged (but by no means required) to use
		2013	C<PERL_ANYEVENT_SUBMODULE> if they have registered the AnyEvent::Submodule
		2014	namespace on CPAN, for any submodule. For example, L<AnyEvent::HTTP> could
		2015	be expected to use C<PERL_ANYEVENT_HTTP_PROXY> (it should not access env
		2016	variables starting with C<AE_>, see below).
		2017
		2018	All variables can also be set via the C<AE_> prefix, that is, instead
		2019	of setting C<PERL_ANYEVENT_VERBOSE> you can also set C<AE_VERBOSE>. In
		2020	case there is a clash btween anyevent and another program that uses
		2021	C<AE_something> you can set the corresponding C<PERL_ANYEVENT_something>
		2022	variable to the empty string, as those variables take precedence.
		2023
		2024	When AnyEvent is first loaded, it copies all C<AE_xxx> env variables
		2025	to their C<PERL_ANYEVENT_xxx> counterpart unless that variable already
		2026	exists. If taint mode is on, then AnyEvent will remove I<all> environment
		2027	variables starting with C<PERL_ANYEVENT_> from C<%ENV> (or replace them
		2028	with C<undef> or the empty string, if the corresaponding C<AE_> variable
		2029	is set).
		2030
		2031	The exact algorithm is currently:
		2032
		2033	1. if taint mode enabled, delete all PERL_ANYEVENT_xyz variables from %ENV
		2034	2. copy over AE_xyz to PERL_ANYEVENT_xyz unless the latter alraedy exists
		2035	3. if taint mode enabled, set all PERL_ANYEVENT_xyz variables to undef.
		2036
		2037	This ensures that child processes will not see the C<AE_> variables.
		2038
		2039	The following environment variables are currently known to AnyEvent:
1776		2040
1777	=over 4	2041	=over 4
1778		2042
1779	=item C<PERL_ANYEVENT_VERBOSE>	2043	=item C<PERL_ANYEVENT_VERBOSE>
1780		2044
1781	By default, AnyEvent will be completely silent except in fatal	2045	By default, AnyEvent will be completely silent except in fatal
1782	conditions. You can set this environment variable to make AnyEvent more	2046	conditions. You can set this environment variable to make AnyEvent more
1783	talkative.	2047	talkative. If you want to do more than just set the global logging level
		2048	you should have a look at C<PERL_ANYEVENT_LOG>, which allows much more
		2049	complex specifications.
1784		2050
1785	When set to C<1> or higher, causes AnyEvent to warn about unexpected	2051	When set to C<5> or higher (warn), causes AnyEvent to warn about unexpected
1786	conditions, such as not being able to load the event model specified by	2052	conditions, such as not being able to load the event model specified by
1787	C<PERL_ANYEVENT_MODEL>.	2053	C<PERL_ANYEVENT_MODEL>, or a guard callback throwing an exception - this
		2054	is the minimum recommended level.
1788		2055
1789	When set to C<2> or higher, cause AnyEvent to report to STDERR which event	2056	When set to C<7> or higher (info), cause AnyEvent to report which event model it
1790	model it chooses.	2057	chooses.
1791		2058
1792	When set to C<8> or higher, then AnyEvent will report extra information on	2059	When set to C<8> or higher (debug), then AnyEvent will report extra information on
1793	which optional modules it loads and how it implements certain features.	2060	which optional modules it loads and how it implements certain features.
		2061
		2062	=item C<PERL_ANYEVENT_LOG>
		2063
		2064	Accepts rather complex logging specifications. For example, you could log
		2065	all C<debug> messages of some module to stderr, warnings and above to
		2066	stderr, and errors and above to syslog, with:
		2067
		2068	PERL_ANYEVENT_LOG=Some::Module=debug,+log:filter=warn,+%syslog:%syslog=error,syslog
		2069
		2070	For the rather extensive details, see L<AnyEvent::Log>.
		2071
		2072	This variable is evaluated when AnyEvent (or L<AnyEvent::Log>) is loaded,
		2073	so will take effect even before AnyEvent has initialised itself.
		2074
		2075	Note that specifying this environment variable causes the L<AnyEvent::Log>
		2076	module to be loaded, while C<PERL_ANYEVENT_VERBOSE> does not, so only
		2077	using the latter saves a few hundred kB of memory until the first message
		2078	is being logged.
1794		2079
1795	=item C<PERL_ANYEVENT_STRICT>	2080	=item C<PERL_ANYEVENT_STRICT>
1796		2081
1797	AnyEvent does not do much argument checking by default, as thorough	2082	AnyEvent does not do much argument checking by default, as thorough
1798	argument checking is very costly. Setting this variable to a true value	2083	argument checking is very costly. Setting this variable to a true value
…		…
1800	check the arguments passed to most method calls. If it finds any problems,	2085	check the arguments passed to most method calls. If it finds any problems,
1801	it will croak.	2086	it will croak.
1802		2087
1803	In other words, enables "strict" mode.	2088	In other words, enables "strict" mode.
1804		2089
1805	Unlike C<use strict> (or it's modern cousin, C<< use L<common::sense>	2090	Unlike C<use strict> (or its modern cousin, C<< use L<common::sense>
1806	>>, it is definitely recommended to keep it off in production. Keeping	2091	>>, it is definitely recommended to keep it off in production. Keeping
1807	C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs	2092	C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs
1808	can be very useful, however.	2093	can be very useful, however.
1809		2094
		2095	=item C<PERL_ANYEVENT_DEBUG_SHELL>
		2096
		2097	If this env variable is set, then its contents will be interpreted by
		2098	C<AnyEvent::Socket::parse_hostport> (after replacing every occurance of
		2099	C<$$> by the process pid) and an C<AnyEvent::Debug::shell> is bound on
		2100	that port. The shell object is saved in C<$AnyEvent::Debug::SHELL>.
		2101
		2102	This happens when the first watcher is created.
		2103
		2104	For example, to bind a debug shell on a unix domain socket in
		2105	F<< /tmp/debug<pid>.sock >>, you could use this:
		2106
		2107	PERL_ANYEVENT_DEBUG_SHELL=/tmp/debug\$\$.sock perlprog
		2108
		2109	Note that creating sockets in F</tmp> is very unsafe on multiuser
		2110	systems.
		2111
		2112	=item C<PERL_ANYEVENT_DEBUG_WRAP>
		2113
		2114	Can be set to C<0>, C<1> or C<2> and enables wrapping of all watchers for
		2115	debugging purposes. See C<AnyEvent::Debug::wrap> for details.
		2116
1810	=item C<PERL_ANYEVENT_MODEL>	2117	=item C<PERL_ANYEVENT_MODEL>
1811		2118
1812	This can be used to specify the event model to be used by AnyEvent, before	2119	This can be used to specify the event model to be used by AnyEvent, before
1813	auto detection and -probing kicks in. It must be a string consisting	2120	auto detection and -probing kicks in.
1814	entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended	2121
		2122	It normally is a string consisting entirely of ASCII letters (e.g. C<EV>
		2123	or C<IOAsync>). The string C<AnyEvent::Impl::> gets prepended and the
1815	and the resulting module name is loaded and if the load was successful,	2124	resulting module name is loaded and - if the load was successful - used as
1816	used as event model. If it fails to load AnyEvent will proceed with	2125	event model backend. If it fails to load then AnyEvent will proceed with
1817	auto detection and -probing.	2126	auto detection and -probing.
1818		2127
1819	This functionality might change in future versions.	2128	If the string ends with C<::> instead (e.g. C<AnyEvent::Impl::EV::>) then
		2129	nothing gets prepended and the module name is used as-is (hint: C<::> at
		2130	the end of a string designates a module name and quotes it appropriately).
1820		2131
1821	For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you	2132	For example, to force the pure perl model (L<AnyEvent::Loop::Perl>) you
1822	could start your program like this:	2133	could start your program like this:
1823		2134
1824	PERL_ANYEVENT_MODEL=Perl perl ...	2135	PERL_ANYEVENT_MODEL=Perl perl ...
1825		2136
1826	=item C<PERL_ANYEVENT_PROTOCOLS>	2137	=item C<PERL_ANYEVENT_PROTOCOLS>
…		…
1842	but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4>	2153	but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4>
1843	- only support IPv4, never try to resolve or contact IPv6	2154	- only support IPv4, never try to resolve or contact IPv6
1844	addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or	2155	addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or
1845	IPv6, but prefer IPv6 over IPv4.	2156	IPv6, but prefer IPv6 over IPv4.
1846		2157
		2158	=item C<PERL_ANYEVENT_HOSTS>
		2159
		2160	This variable, if specified, overrides the F</etc/hosts> file used by
		2161	L<AnyEvent::Socket>C<::resolve_sockaddr>, i.e. hosts aliases will be read
		2162	from that file instead.
		2163
1847	=item C<PERL_ANYEVENT_EDNS0>	2164	=item C<PERL_ANYEVENT_EDNS0>
1848		2165
1849	Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension	2166	Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension for
1850	for DNS. This extension is generally useful to reduce DNS traffic, but	2167	DNS. This extension is generally useful to reduce DNS traffic, especially
1851	some (broken) firewalls drop such DNS packets, which is why it is off by	2168	when DNSSEC is involved, but some (broken) firewalls drop such DNS
1852	default.	2169	packets, which is why it is off by default.
1853		2170
1854	Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce	2171	Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce
1855	EDNS0 in its DNS requests.	2172	EDNS0 in its DNS requests.
1856		2173
1857	=item C<PERL_ANYEVENT_MAX_FORKS>	2174	=item C<PERL_ANYEVENT_MAX_FORKS>
…		…
1865	resolver - this is the maximum number of parallel DNS requests that are	2182	resolver - this is the maximum number of parallel DNS requests that are
1866	sent to the DNS server.	2183	sent to the DNS server.
1867		2184
1868	=item C<PERL_ANYEVENT_RESOLV_CONF>	2185	=item C<PERL_ANYEVENT_RESOLV_CONF>
1869		2186
1870	The file to use instead of F</etc/resolv.conf> (or OS-specific	2187	The absolute path to a F<resolv.conf>-style file to use instead of
1871	configuration) in the default resolver. When set to the empty string, no	2188	F</etc/resolv.conf> (or the OS-specific configuration) in the default
1872	default config will be used.	2189	resolver, or the empty string to select the default configuration.
1873		2190
1874	=item C<PERL_ANYEVENT_CA_FILE>, C<PERL_ANYEVENT_CA_PATH>.	2191	=item C<PERL_ANYEVENT_CA_FILE>, C<PERL_ANYEVENT_CA_PATH>.
1875		2192
1876	When neither C<ca_file> nor C<ca_path> was specified during	2193	When neither C<ca_file> nor C<ca_path> was specified during
1877	L<AnyEvent::TLS> context creation, and either of these environment	2194	L<AnyEvent::TLS> context creation, and either of these environment
1878	variables exist, they will be used to specify CA certificate locations	2195	variables are nonempty, they will be used to specify CA certificate
1879	instead of a system-dependent default.	2196	locations instead of a system-dependent default.
1880		2197
1881	=item C<PERL_ANYEVENT_AVOID_GUARD> and C<PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT>	2198	=item C<PERL_ANYEVENT_AVOID_GUARD> and C<PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT>
1882		2199
1883	When these are set to C<1>, then the respective modules are not	2200	When these are set to C<1>, then the respective modules are not
1884	loaded. Mostly good for testing AnyEvent itself.	2201	loaded. Mostly good for testing AnyEvent itself.
…		…
2032		2349
2033	The actual code goes further and collects all errors (C<die>s, exceptions)	2350	The actual code goes further and collects all errors (C<die>s, exceptions)
2034	that occurred during request processing. The C<result> method detects	2351	that occurred during request processing. The C<result> method detects
2035	whether an exception as thrown (it is stored inside the $txn object)	2352	whether an exception as thrown (it is stored inside the $txn object)
2036	and just throws the exception, which means connection errors and other	2353	and just throws the exception, which means connection errors and other
2037	problems get reported tot he code that tries to use the result, not in a	2354	problems get reported to the code that tries to use the result, not in a
2038	random callback.	2355	random callback.
2039		2356
2040	All of this enables the following usage styles:	2357	All of this enables the following usage styles:
2041		2358
2042	1. Blocking:	2359	1. Blocking:
…		…
2216	(even when used without AnyEvent), but most event loops have acceptable	2533	(even when used without AnyEvent), but most event loops have acceptable
2217	performance with or without AnyEvent.	2534	performance with or without AnyEvent.
2218		2535
2219	=item * The overhead AnyEvent adds is usually much smaller than the overhead of	2536	=item * The overhead AnyEvent adds is usually much smaller than the overhead of
2220	the actual event loop, only with extremely fast event loops such as EV	2537	the actual event loop, only with extremely fast event loops such as EV
2221	adds AnyEvent significant overhead.	2538	does AnyEvent add significant overhead.
2222		2539
2223	=item * You should avoid POE like the plague if you want performance or	2540	=item * You should avoid POE like the plague if you want performance or
2224	reasonable memory usage.	2541	reasonable memory usage.
2225		2542
2226	=back	2543	=back
…		…
2456	unless defined $SIG{PIPE};	2773	unless defined $SIG{PIPE};
2457		2774
2458	=head1 RECOMMENDED/OPTIONAL MODULES	2775	=head1 RECOMMENDED/OPTIONAL MODULES
2459		2776
2460	One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and	2777	One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and
2461	it's built-in modules) are required to use it.	2778	its built-in modules) are required to use it.
2462		2779
2463	That does not mean that AnyEvent won't take advantage of some additional	2780	That does not mean that AnyEvent won't take advantage of some additional
2464	modules if they are installed.	2781	modules if they are installed.
2465		2782
2466	This section explains which additional modules will be used, and how they	2783	This section explains which additional modules will be used, and how they
…		…
2499	automatic timer adjustments even when no monotonic clock is available,	2816	automatic timer adjustments even when no monotonic clock is available,
2500	can take avdantage of advanced kernel interfaces such as C<epoll> and	2817	can take avdantage of advanced kernel interfaces such as C<epoll> and
2501	C<kqueue>, and is the fastest backend I<by far>. You can even embed	2818	C<kqueue>, and is the fastest backend I<by far>. You can even embed
2502	L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>).	2819	L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>).
2503		2820
		2821	If you only use backends that rely on another event loop (e.g. C<Tk>),
		2822	then this module will do nothing for you.
		2823
2504	=item L<Guard>	2824	=item L<Guard>
2505		2825
2506	The guard module, when used, will be used to implement	2826	The guard module, when used, will be used to implement
2507	C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a	2827	C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a
2508	lot less memory), but otherwise doesn't affect guard operation much. It is	2828	lot less memory), but otherwise doesn't affect guard operation much. It is
2509	purely used for performance.	2829	purely used for performance.
2510		2830
2511	=item L<JSON> and L<JSON::XS>	2831	=item L<JSON> and L<JSON::XS>
2512		2832
2513	One of these modules is required when you want to read or write JSON data	2833	One of these modules is required when you want to read or write JSON data
2514	via L<AnyEvent::Handle>. It is also written in pure-perl, but can take	2834	via L<AnyEvent::Handle>. L<JSON> is also written in pure-perl, but can take
2515	advantage of the ultra-high-speed L<JSON::XS> module when it is installed.	2835	advantage of the ultra-high-speed L<JSON::XS> module when it is installed.
2516
2517	In fact, L<AnyEvent::Handle> will use L<JSON::XS> by default if it is
2518	installed.
2519		2836
2520	=item L<Net::SSLeay>	2837	=item L<Net::SSLeay>
2521		2838
2522	Implementing TLS/SSL in Perl is certainly interesting, but not very	2839	Implementing TLS/SSL in Perl is certainly interesting, but not very
2523	worthwhile: If this module is installed, then L<AnyEvent::Handle> (with	2840	worthwhile: If this module is installed, then L<AnyEvent::Handle> (with
2524	the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL.	2841	the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL.
2525		2842
2526	=item L<Time::HiRes>	2843	=item L<Time::HiRes>
2527		2844
2528	This module is part of perl since release 5.008. It will be used when the	2845	This module is part of perl since release 5.008. It will be used when the
2529	chosen event library does not come with a timing source on it's own. The	2846	chosen event library does not come with a timing source of its own. The
2530	pure-perl event loop (L<AnyEvent::Impl::Perl>) will additionally use it to	2847	pure-perl event loop (L<AnyEvent::Loop>) will additionally load it to
2531	try to use a monotonic clock for timing stability.	2848	try to use a monotonic clock for timing stability.
2532		2849
2533	=back	2850	=back
2534		2851
2535		2852
2536	=head1 FORK	2853	=head1 FORK
2537		2854
2538	Most event libraries are not fork-safe. The ones who are usually are	2855	Most event libraries are not fork-safe. The ones who are usually are
2539	because they rely on inefficient but fork-safe C<select> or C<poll>	2856	because they rely on inefficient but fork-safe C<select> or C<poll> calls
2540	calls. Only L<EV> is fully fork-aware.	2857	- higher performance APIs such as BSD's kqueue or the dreaded Linux epoll
		2858	are usually badly thought-out hacks that are incompatible with fork in
		2859	one way or another. Only L<EV> is fully fork-aware and ensures that you
		2860	continue event-processing in both parent and child (or both, if you know
		2861	what you are doing).
2541		2862
2542	This means that, in general, you cannot fork and do event processing	2863	This means that, in general, you cannot fork and do event processing in
2543	in the child if a watcher was created before the fork (which in turn	2864	the child if the event library was initialised before the fork (which
2544	initialises the event library).	2865	usually happens when the first AnyEvent watcher is created, or the library
		2866	is loaded).
2545		2867
2546	If you have to fork, you must either do so I<before> creating your first	2868	If you have to fork, you must either do so I<before> creating your first
2547	watcher OR you must not use AnyEvent at all in the child OR you must do	2869	watcher OR you must not use AnyEvent at all in the child OR you must do
2548	something completely out of the scope of AnyEvent.	2870	something completely out of the scope of AnyEvent.
2549		2871
2550	The problem of doing event processing in the parent I<and> the child	2872	The problem of doing event processing in the parent I<and> the child
2551	is much more complicated: even for backends that I<are> fork-aware or	2873	is much more complicated: even for backends that I<are> fork-aware or
2552	fork-safe, their behaviour is not usually what you want: fork clones all	2874	fork-safe, their behaviour is not usually what you want: fork clones all
2553	watchers, that means all timers, I/O watchers etc. are active in both	2875	watchers, that means all timers, I/O watchers etc. are active in both
2554	parent and child, which is almost never what you want.	2876	parent and child, which is almost never what you want. USing C<exec>
		2877	to start worker children from some kind of manage rprocess is usually
		2878	preferred, because it is much easier and cleaner, at the expense of having
		2879	to have another binary.
2555		2880
2556		2881
2557	=head1 SECURITY CONSIDERATIONS	2882	=head1 SECURITY CONSIDERATIONS
2558		2883
2559	AnyEvent can be forced to load any event model via	2884	AnyEvent can be forced to load any event model via
…		…
2589	pronounced).	2914	pronounced).
2590		2915
2591		2916
2592	=head1 SEE ALSO	2917	=head1 SEE ALSO
2593		2918
2594	Utility functions: L<AnyEvent::Util>.	2919	Tutorial/Introduction: L<AnyEvent::Intro>.
2595		2920
2596	Event modules: L<EV>, L<EV::Glib>, L<Glib::EV>, L<Event>, L<Glib::Event>,	2921	FAQ: L<AnyEvent::FAQ>.
2597	L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.	2922
		2923	Utility functions: L<AnyEvent::Util> (misc. grab-bag), L<AnyEvent::Log>
		2924	(simply logging).
		2925
		2926	Development/Debugging: L<AnyEvent::Strict> (stricter checking),
		2927	L<AnyEvent::Debug> (interactive shell, watcher tracing).
		2928
		2929	Supported event modules: L<AnyEvent::Loop>, L<EV>, L<EV::Glib>,
		2930	L<Glib::EV>, L<Event>, L<Glib::Event>, L<Glib>, L<Tk>, L<Event::Lib>,
		2931	L<Qt>, L<POE>, L<FLTK>.
2598		2932
2599	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,	2933	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,
2600	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,	2934	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,
2601	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,	2935	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,
2602	L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>, L<Anyevent::Impl::Irssi>.	2936	L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>, L<Anyevent::Impl::Irssi>,
		2937	L<AnyEvent::Impl::FLTK>.
2603		2938
2604	Non-blocking file handles, sockets, TCP clients and	2939	Non-blocking handles, pipes, stream sockets, TCP clients and
2605	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.	2940	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.
2606		2941
2607	Asynchronous DNS: L<AnyEvent::DNS>.	2942	Asynchronous DNS: L<AnyEvent::DNS>.
2608		2943
2609	Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>,	2944	Thread support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>.
2610	L<Coro::Event>,
2611		2945
2612	Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::XMPP>,	2946	Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::IRC>,
2613	L<AnyEvent::HTTP>.	2947	L<AnyEvent::HTTP>.
2614		2948
2615		2949
2616	=head1 AUTHOR	2950	=head1 AUTHOR
2617		2951

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