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Revision 1.296 by root, Tue Nov 17 01:19:49 2009 UTC vs.
Revision 1.388 by root, Sun Oct 2 01:22:01 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
…		…
403		407
404	Example: exit on SIGINT	408	Example: exit on SIGINT
405		409
406	my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });	410	my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });
407		411
		412	=head3 Restart Behaviour
		413
		414	While restart behaviour is up to the event loop implementation, most will
		415	not restart syscalls (that includes L<Async::Interrupt> and AnyEvent's
		416	pure perl implementation).
		417
		418	=head3 Safe/Unsafe Signals
		419
		420	Perl signals can be either "safe" (synchronous to opcode handling)
		421	or "unsafe" (asynchronous) - the former might delay signal delivery
		422	indefinitely, the latter might corrupt your memory.
		423
		424	AnyEvent signal handlers are, in addition, synchronous to the event loop,
		425	i.e. they will not interrupt your running perl program but will only be
		426	called as part of the normal event handling (just like timer, I/O etc.
		427	callbacks, too).
		428
408	=head3 Signal Races, Delays and Workarounds	429	=head3 Signal Races, Delays and Workarounds
409		430
410	Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support attaching	431	Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support
411	callbacks to signals in a generic way, which is a pity, as you cannot	432	attaching callbacks to signals in a generic way, which is a pity,
412	do race-free signal handling in perl, requiring C libraries for	433	as you cannot do race-free signal handling in perl, requiring
413	this. AnyEvent will try to do it's best, which means in some cases,	434	C libraries for this. AnyEvent will try to do its best, which
414	signals will be delayed. The maximum time a signal might be delayed is	435	means in some cases, signals will be delayed. The maximum time
415	specified in C<$AnyEvent::MAX_SIGNAL_LATENCY> (default: 10 seconds). This	436	a signal might be delayed is 10 seconds by default, but can
416	variable can be changed only before the first signal watcher is created,	437	be overriden via C<$ENV{PERL_ANYEVENT_MAX_SIGNAL_LATENCY}> or
417	and should be left alone otherwise. This variable determines how often	438	C<$AnyEvent::MAX_SIGNAL_LATENCY> - see the Ö<ENVIRONMENT VARIABLES>
418	AnyEvent polls for signals (in case a wake-up was missed). Higher values	439	section for details.
419	will cause fewer spurious wake-ups, which is better for power and CPU
420	saving.
421		440
422	All these problems can be avoided by installing the optional	441	All these problems can be avoided by installing the optional
423	L<Async::Interrupt> module, which works with most event loops. It will not	442	L<Async::Interrupt> module, which works with most event loops. It will not
424	work with inherently broken event loops such as L<Event> or L<Event::Lib>	443	work with inherently broken event loops such as L<Event> or L<Event::Lib>
425	(and not with L<POE> currently, as POE does it's own workaround with	444	(and not with L<POE> currently). For those, you just have to suffer the
426	one-second latency). For those, you just have to suffer the delays.	445	delays.
427		446
428	=head2 CHILD PROCESS WATCHERS	447	=head2 CHILD PROCESS WATCHERS
429		448
430	$w = AnyEvent->child (pid => <process id>, cb => <callback>);	449	$w = AnyEvent->child (pid => <process id>, cb => <callback>);
431		450
432	You can also watch on a child process exit and catch its exit status.	451	You can also watch for a child process exit and catch its exit status.
433		452
434	The child process is specified by the C<pid> argument (one some backends,	453	The child process is specified by the C<pid> argument (on some backends,
435	using C<0> watches for any child process exit, on others this will	454	using C<0> watches for any child process exit, on others this will
436	croak). The watcher will be triggered only when the child process has	455	croak). The watcher will be triggered only when the child process has
437	finished and an exit status is available, not on any trace events	456	finished and an exit status is available, not on any trace events
438	(stopped/continued).	457	(stopped/continued).
439		458
…		…
461	thing in an AnyEvent program, you I<have> to create at least one	480	thing in an AnyEvent program, you I<have> to create at least one
462	watcher before you C<fork> the child (alternatively, you can call	481	watcher before you C<fork> the child (alternatively, you can call
463	C<AnyEvent::detect>).	482	C<AnyEvent::detect>).
464		483
465	As most event loops do not support waiting for child events, they will be	484	As most event loops do not support waiting for child events, they will be
466	emulated by AnyEvent in most cases, in which the latency and race problems	485	emulated by AnyEvent in most cases, in which case the latency and race
467	mentioned in the description of signal watchers apply.	486	problems mentioned in the description of signal watchers apply.
468		487
469	Example: fork a process and wait for it	488	Example: fork a process and wait for it
470		489
471	my $done = AnyEvent->condvar;	490	my $done = AnyEvent->condvar;
472		491
…		…
486		505
487	=head2 IDLE WATCHERS	506	=head2 IDLE WATCHERS
488		507
489	$w = AnyEvent->idle (cb => <callback>);	508	$w = AnyEvent->idle (cb => <callback>);
490		509
491	Sometimes there is a need to do something, but it is not so important	510	This will repeatedly invoke the callback after the process becomes idle,
492	to do it instantly, but only when there is nothing better to do. This	511	until either the watcher is destroyed or new events have been detected.
493	"nothing better to do" is usually defined to be "no other events need
494	attention by the event loop".
495		512
496	Idle watchers ideally get invoked when the event loop has nothing	513	Idle watchers are useful when there is a need to do something, but it
497	better to do, just before it would block the process to wait for new	514	is not so important (or wise) to do it instantly. The callback will be
498	events. Instead of blocking, the idle watcher is invoked.	515	invoked only when there is "nothing better to do", which is usually
		516	defined as "all outstanding events have been handled and no new events
		517	have been detected". That means that idle watchers ideally get invoked
		518	when the event loop has just polled for new events but none have been
		519	detected. Instead of blocking to wait for more events, the idle watchers
		520	will be invoked.
499		521
500	Most event loops unfortunately do not really support idle watchers (only	522	Unfortunately, most event loops do not really support idle watchers (only
501	EV, Event and Glib do it in a usable fashion) - for the rest, AnyEvent	523	EV, Event and Glib do it in a usable fashion) - for the rest, AnyEvent
502	will simply call the callback "from time to time".	524	will simply call the callback "from time to time".
503		525
504	Example: read lines from STDIN, but only process them when the	526	Example: read lines from STDIN, but only process them when the
505	program is otherwise idle:	527	program is otherwise idle:
…		…
533	will actively watch for new events and call your callbacks.	555	will actively watch for new events and call your callbacks.
534		556
535	AnyEvent is slightly different: it expects somebody else to run the event	557	AnyEvent is slightly different: it expects somebody else to run the event
536	loop and will only block when necessary (usually when told by the user).	558	loop and will only block when necessary (usually when told by the user).
537		559
538	The instrument to do that is called a "condition variable", so called	560	The tool to do that is called a "condition variable", so called because
539	because they represent a condition that must become true.	561	they represent a condition that must become true.
540		562
541	Now is probably a good time to look at the examples further below.	563	Now is probably a good time to look at the examples further below.
542		564
543	Condition variables can be created by calling the C<< AnyEvent->condvar	565	Condition variables can be created by calling the C<< AnyEvent->condvar
544	>> method, usually without arguments. The only argument pair allowed is	566	>> method, usually without arguments. The only argument pair allowed is
…		…
549	After creation, the condition variable is "false" until it becomes "true"	571	After creation, the condition variable is "false" until it becomes "true"
550	by calling the C<send> method (or calling the condition variable as if it	572	by calling the C<send> method (or calling the condition variable as if it
551	were a callback, read about the caveats in the description for the C<<	573	were a callback, read about the caveats in the description for the C<<
552	->send >> method).	574	->send >> method).
553		575
554	Condition variables are similar to callbacks, except that you can	576	Since condition variables are the most complex part of the AnyEvent API, here are
555	optionally wait for them. They can also be called merge points - points	577	some different mental models of what they are - pick the ones you can connect to:
556	in time where multiple outstanding events have been processed. And yet	578
557	another way to call them is transactions - each condition variable can be	579	=over 4
558	used to represent a transaction, which finishes at some point and delivers	580
559	a result. And yet some people know them as "futures" - a promise to	581	=item * Condition variables are like callbacks - you can call them (and pass them instead
560	compute/deliver something that you can wait for.	582	of callbacks). Unlike callbacks however, you can also wait for them to be called.
		583
		584	=item * Condition variables are signals - one side can emit or send them,
		585	the other side can wait for them, or install a handler that is called when
		586	the signal fires.
		587
		588	=item * Condition variables are like "Merge Points" - points in your program
		589	where you merge multiple independent results/control flows into one.
		590
		591	=item * Condition variables represent a transaction - functions that start
		592	some kind of transaction can return them, leaving the caller the choice
		593	between waiting in a blocking fashion, or setting a callback.
		594
		595	=item * Condition variables represent future values, or promises to deliver
		596	some result, long before the result is available.
		597
		598	=back
561		599
562	Condition variables are very useful to signal that something has finished,	600	Condition variables are very useful to signal that something has finished,
563	for example, if you write a module that does asynchronous http requests,	601	for example, if you write a module that does asynchronous http requests,
564	then a condition variable would be the ideal candidate to signal the	602	then a condition variable would be the ideal candidate to signal the
565	availability of results. The user can either act when the callback is	603	availability of results. The user can either act when the callback is
…		…
578		616
579	Condition variables are represented by hash refs in perl, and the keys	617	Condition variables are represented by hash refs in perl, and the keys
580	used by AnyEvent itself are all named C<_ae_XXX> to make subclassing	618	used by AnyEvent itself are all named C<_ae_XXX> to make subclassing
581	easy (it is often useful to build your own transaction class on top of	619	easy (it is often useful to build your own transaction class on top of
582	AnyEvent). To subclass, use C<AnyEvent::CondVar> as base class and call	620	AnyEvent). To subclass, use C<AnyEvent::CondVar> as base class and call
583	it's C<new> method in your own C<new> method.	621	its C<new> method in your own C<new> method.
584		622
585	There are two "sides" to a condition variable - the "producer side" which	623	There are two "sides" to a condition variable - the "producer side" which
586	eventually calls C<< -> send >>, and the "consumer side", which waits	624	eventually calls C<< -> send >>, and the "consumer side", which waits
587	for the send to occur.	625	for the send to occur.
588		626
589	Example: wait for a timer.	627	Example: wait for a timer.
590		628
591	# wait till the result is ready	629	# condition: "wait till the timer is fired"
592	my $result_ready = AnyEvent->condvar;	630	my $timer_fired = AnyEvent->condvar;
593		631
594	# do something such as adding a timer	632	# create the timer - we could wait for, say
595	# or socket watcher the calls $result_ready->send	633	# a handle becomign ready, or even an
596	# when the "result" is ready.	634	# AnyEvent::HTTP request to finish, but
597	# in this case, we simply use a timer:	635	# in this case, we simply use a timer:
598	my $w = AnyEvent->timer (	636	my $w = AnyEvent->timer (
599	after => 1,	637	after => 1,
600	cb => sub { $result_ready->send },	638	cb => sub { $timer_fired->send },
601	);	639	);
602		640
603	# this "blocks" (while handling events) till the callback	641	# this "blocks" (while handling events) till the callback
604	# calls ->send	642	# calls ->send
605	$result_ready->recv;	643	$timer_fired->recv;
606		644
607	Example: wait for a timer, but take advantage of the fact that condition	645	Example: wait for a timer, but take advantage of the fact that condition
608	variables are also callable directly.	646	variables are also callable directly.
609		647
610	my $done = AnyEvent->condvar;	648	my $done = AnyEvent->condvar;
…		…
653	they were a code reference). Calling them directly is the same as calling	691	they were a code reference). Calling them directly is the same as calling
654	C<send>.	692	C<send>.
655		693
656	=item $cv->croak ($error)	694	=item $cv->croak ($error)
657		695
658	Similar to send, but causes all call's to C<< ->recv >> to invoke	696	Similar to send, but causes all calls to C<< ->recv >> to invoke
659	C<Carp::croak> with the given error message/object/scalar.	697	C<Carp::croak> with the given error message/object/scalar.
660		698
661	This can be used to signal any errors to the condition variable	699	This can be used to signal any errors to the condition variable
662	user/consumer. Doing it this way instead of calling C<croak> directly	700	user/consumer. Doing it this way instead of calling C<croak> directly
663	delays the error detetcion, but has the overwhelmign advantage that it	701	delays the error detection, but has the overwhelming advantage that it
664	diagnoses the error at the place where the result is expected, and not	702	diagnoses the error at the place where the result is expected, and not
665	deep in some event clalback without connection to the actual code causing	703	deep in some event callback with no connection to the actual code causing
666	the problem.	704	the problem.
667		705
668	=item $cv->begin ([group callback])	706	=item $cv->begin ([group callback])
669		707
670	=item $cv->end	708	=item $cv->end
…		…
708	one call to C<begin>, so the condvar waits for all calls to C<end> before	746	one call to C<begin>, so the condvar waits for all calls to C<end> before
709	sending.	747	sending.
710		748
711	The ping example mentioned above is slightly more complicated, as the	749	The ping example mentioned above is slightly more complicated, as the
712	there are results to be passwd back, and the number of tasks that are	750	there are results to be passwd back, and the number of tasks that are
713	begung can potentially be zero:	751	begun can potentially be zero:
714		752
715	my $cv = AnyEvent->condvar;	753	my $cv = AnyEvent->condvar;
716		754
717	my %result;	755	my %result;
718	$cv->begin (sub { shift->send (\%result) });	756	$cv->begin (sub { shift->send (\%result) });
…		…
739	to be called once the counter reaches C<0>, and second, it ensures that	777	to be called once the counter reaches C<0>, and second, it ensures that
740	C<send> is called even when C<no> hosts are being pinged (the loop	778	C<send> is called even when C<no> hosts are being pinged (the loop
741	doesn't execute once).	779	doesn't execute once).
742		780
743	This is the general pattern when you "fan out" into multiple (but	781	This is the general pattern when you "fan out" into multiple (but
744	potentially none) subrequests: use an outer C<begin>/C<end> pair to set	782	potentially zero) subrequests: use an outer C<begin>/C<end> pair to set
745	the callback and ensure C<end> is called at least once, and then, for each	783	the callback and ensure C<end> is called at least once, and then, for each
746	subrequest you start, call C<begin> and for each subrequest you finish,	784	subrequest you start, call C<begin> and for each subrequest you finish,
747	call C<end>.	785	call C<end>.
748		786
749	=back	787	=back
…		…
756	=over 4	794	=over 4
757		795
758	=item $cv->recv	796	=item $cv->recv
759		797
760	Wait (blocking if necessary) until the C<< ->send >> or C<< ->croak	798	Wait (blocking if necessary) until the C<< ->send >> or C<< ->croak
761	>> methods have been called on c<$cv>, while servicing other watchers	799	>> methods have been called on C<$cv>, while servicing other watchers
762	normally.	800	normally.
763		801
764	You can only wait once on a condition - additional calls are valid but	802	You can only wait once on a condition - additional calls are valid but
765	will return immediately.	803	will return immediately.
766		804
…		…
783	caller decide whether the call will block or not (for example, by coupling	821	caller decide whether the call will block or not (for example, by coupling
784	condition variables with some kind of request results and supporting	822	condition variables with some kind of request results and supporting
785	callbacks so the caller knows that getting the result will not block,	823	callbacks so the caller knows that getting the result will not block,
786	while still supporting blocking waits if the caller so desires).	824	while still supporting blocking waits if the caller so desires).
787		825
788	You can ensure that C<< -recv >> never blocks by setting a callback and	826	You can ensure that C<< ->recv >> never blocks by setting a callback and
789	only calling C<< ->recv >> from within that callback (or at a later	827	only calling C<< ->recv >> from within that callback (or at a later
790	time). This will work even when the event loop does not support blocking	828	time). This will work even when the event loop does not support blocking
791	waits otherwise.	829	waits otherwise.
792		830
793	=item $bool = $cv->ready	831	=item $bool = $cv->ready
…		…
798	=item $cb = $cv->cb ($cb->($cv))	836	=item $cb = $cv->cb ($cb->($cv))
799		837
800	This is a mutator function that returns the callback set and optionally	838	This is a mutator function that returns the callback set and optionally
801	replaces it before doing so.	839	replaces it before doing so.
802		840
803	The callback will be called when the condition becomes (or already was)	841	The callback will be called when the condition becomes "true", i.e. when
804	"true", i.e. when C<send> or C<croak> are called (or were called), with	842	C<send> or C<croak> are called, with the only argument being the
805	the only argument being the condition variable itself. Calling C<recv>	843	condition variable itself. If the condition is already true, the
		844	callback is called immediately when it is set. Calling C<recv> inside
806	inside the callback or at any later time is guaranteed not to block.	845	the callback or at any later time is guaranteed not to block.
807		846
808	=back	847	=back
809		848
810	=head1 SUPPORTED EVENT LOOPS/BACKENDS	849	=head1 SUPPORTED EVENT LOOPS/BACKENDS
811		850
…		…
819	use. If EV is not installed, then AnyEvent will fall back to its own	858	use. If EV is not installed, then AnyEvent will fall back to its own
820	pure-perl implementation, which is available everywhere as it comes with	859	pure-perl implementation, which is available everywhere as it comes with
821	AnyEvent itself.	860	AnyEvent itself.
822		861
823	AnyEvent::Impl::EV based on EV (interface to libev, best choice).	862	AnyEvent::Impl::EV based on EV (interface to libev, best choice).
824	AnyEvent::Impl::Perl pure-perl implementation, fast and portable.	863	AnyEvent::Impl::Perl pure-perl AnyEvent::Loop, fast and portable.
825		864
826	=item Backends that are transparently being picked up when they are used.	865	=item Backends that are transparently being picked up when they are used.
827		866
828	These will be used when they are currently loaded when the first watcher	867	These will be used if they are already loaded when the first watcher
829	is created, in which case it is assumed that the application is using	868	is created, in which case it is assumed that the application is using
830	them. This means that AnyEvent will automatically pick the right backend	869	them. This means that AnyEvent will automatically pick the right backend
831	when the main program loads an event module before anything starts to	870	when the main program loads an event module before anything starts to
832	create watchers. Nothing special needs to be done by the main program.	871	create watchers. Nothing special needs to be done by the main program.
833		872
…		…
835	AnyEvent::Impl::Glib based on Glib, slow but very stable.	874	AnyEvent::Impl::Glib based on Glib, slow but very stable.
836	AnyEvent::Impl::Tk based on Tk, very broken.	875	AnyEvent::Impl::Tk based on Tk, very broken.
837	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.	876	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
838	AnyEvent::Impl::POE based on POE, very slow, some limitations.	877	AnyEvent::Impl::POE based on POE, very slow, some limitations.
839	AnyEvent::Impl::Irssi used when running within irssi.	878	AnyEvent::Impl::Irssi used when running within irssi.
		879	AnyEvent::Impl::IOAsync based on IO::Async.
		880	AnyEvent::Impl::Cocoa based on Cocoa::EventLoop.
		881	AnyEvent::Impl::FLTK based on FLTK (fltk 2 binding).
840		882
841	=item Backends with special needs.	883	=item Backends with special needs.
842		884
843	Qt requires the Qt::Application to be instantiated first, but will	885	Qt requires the Qt::Application to be instantiated first, but will
844	otherwise be picked up automatically. As long as the main program	886	otherwise be picked up automatically. As long as the main program
845	instantiates the application before any AnyEvent watchers are created,	887	instantiates the application before any AnyEvent watchers are created,
846	everything should just work.	888	everything should just work.
847		889
848	AnyEvent::Impl::Qt based on Qt.	890	AnyEvent::Impl::Qt based on Qt.
849		891
850	Support for IO::Async can only be partial, as it is too broken and
851	architecturally limited to even support the AnyEvent API. It also
852	is the only event loop that needs the loop to be set explicitly, so
853	it can only be used by a main program knowing about AnyEvent. See
854	L<AnyEvent::Impl::Async> for the gory details.
855
856	AnyEvent::Impl::IOAsync based on IO::Async, cannot be autoprobed.
857
858	=item Event loops that are indirectly supported via other backends.	892	=item Event loops that are indirectly supported via other backends.
859		893
860	Some event loops can be supported via other modules:	894	Some event loops can be supported via other modules:
861		895
862	There is no direct support for WxWidgets (L<Wx>) or L<Prima>.	896	There is no direct support for WxWidgets (L<Wx>) or L<Prima>.
…		…
887	Contains C<undef> until the first watcher is being created, before the	921	Contains C<undef> until the first watcher is being created, before the
888	backend has been autodetected.	922	backend has been autodetected.
889		923
890	Afterwards it contains the event model that is being used, which is the	924	Afterwards it contains the event model that is being used, which is the
891	name of the Perl class implementing the model. This class is usually one	925	name of the Perl class implementing the model. This class is usually one
892	of the C<AnyEvent::Impl:xxx> modules, but can be any other class in the	926	of the C<AnyEvent::Impl::xxx> modules, but can be any other class in the
893	case AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode> it	927	case AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode> it
894	will be C<urxvt::anyevent>).	928	will be C<urxvt::anyevent>).
895		929
896	=item AnyEvent::detect	930	=item AnyEvent::detect
897		931
898	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model	932	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model
899	if necessary. You should only call this function right before you would	933	if necessary. You should only call this function right before you would
900	have created an AnyEvent watcher anyway, that is, as late as possible at	934	have created an AnyEvent watcher anyway, that is, as late as possible at
901	runtime, and not e.g. while initialising of your module.	935	runtime, and not e.g. during initialisation of your module.
		936
		937	The effect of calling this function is as if a watcher had been created
		938	(specifically, actions that happen "when the first watcher is created"
		939	happen when calling detetc as well).
902		940
903	If you need to do some initialisation before AnyEvent watchers are	941	If you need to do some initialisation before AnyEvent watchers are
904	created, use C<post_detect>.	942	created, use C<post_detect>.
905		943
906	=item $guard = AnyEvent::post_detect { BLOCK }	944	=item $guard = AnyEvent::post_detect { BLOCK }
907		945
908	Arranges for the code block to be executed as soon as the event model is	946	Arranges for the code block to be executed as soon as the event model is
909	autodetected (or immediately if this has already happened).	947	autodetected (or immediately if that has already happened).
910		948
911	The block will be executed I<after> the actual backend has been detected	949	The block will be executed I<after> the actual backend has been detected
912	(C<$AnyEvent::MODEL> is set), but I<before> any watchers have been	950	(C<$AnyEvent::MODEL> is set), but I<before> any watchers have been
913	created, so it is possible to e.g. patch C<@AnyEvent::ISA> or do	951	created, so it is possible to e.g. patch C<@AnyEvent::ISA> or do
914	other initialisations - see the sources of L<AnyEvent::Strict> or	952	other initialisations - see the sources of L<AnyEvent::Strict> or
…		…
923	that automatically removes the callback again when it is destroyed (or	961	that automatically removes the callback again when it is destroyed (or
924	C<undef> when the hook was immediately executed). See L<AnyEvent::AIO> for	962	C<undef> when the hook was immediately executed). See L<AnyEvent::AIO> for
925	a case where this is useful.	963	a case where this is useful.
926		964
927	Example: Create a watcher for the IO::AIO module and store it in	965	Example: Create a watcher for the IO::AIO module and store it in
928	C<$WATCHER>. Only do so after the event loop is initialised, though.	966	C<$WATCHER>, but do so only do so after the event loop is initialised.
929		967
930	our WATCHER;	968	our WATCHER;
931		969
932	my $guard = AnyEvent::post_detect {	970	my $guard = AnyEvent::post_detect {
933	$WATCHER = AnyEvent->io (fh => IO::AIO::poll_fileno, poll => 'r', cb => \&IO::AIO::poll_cb);	971	$WATCHER = AnyEvent->io (fh => IO::AIO::poll_fileno, poll => 'r', cb => \&IO::AIO::poll_cb);
…		…
941	$WATCHER ||= $guard;	979	$WATCHER ||= $guard;
942		980
943	=item @AnyEvent::post_detect	981	=item @AnyEvent::post_detect
944		982
945	If there are any code references in this array (you can C<push> to it	983	If there are any code references in this array (you can C<push> to it
946	before or after loading AnyEvent), then they will called directly after	984	before or after loading AnyEvent), then they will be called directly
947	the event loop has been chosen.	985	after the event loop has been chosen.
948		986
949	You should check C<$AnyEvent::MODEL> before adding to this array, though:	987	You should check C<$AnyEvent::MODEL> before adding to this array, though:
950	if it is defined then the event loop has already been detected, and the	988	if it is defined then the event loop has already been detected, and the
951	array will be ignored.	989	array will be ignored.
952		990
953	Best use C<AnyEvent::post_detect { BLOCK }> when your application allows	991	Best use C<AnyEvent::post_detect { BLOCK }> when your application allows
954	it,as it takes care of these details.	992	it, as it takes care of these details.
955		993
956	This variable is mainly useful for modules that can do something useful	994	This variable is mainly useful for modules that can do something useful
957	when AnyEvent is used and thus want to know when it is initialised, but do	995	when AnyEvent is used and thus want to know when it is initialised, but do
958	not need to even load it by default. This array provides the means to hook	996	not need to even load it by default. This array provides the means to hook
959	into AnyEvent passively, without loading it.	997	into AnyEvent passively, without loading it.
960		998
		999	Example: To load Coro::AnyEvent whenever Coro and AnyEvent are used
		1000	together, you could put this into Coro (this is the actual code used by
		1001	Coro to accomplish this):
		1002
		1003	if (defined $AnyEvent::MODEL) {
		1004	# AnyEvent already initialised, so load Coro::AnyEvent
		1005	require Coro::AnyEvent;
		1006	} else {
		1007	# AnyEvent not yet initialised, so make sure to load Coro::AnyEvent
		1008	# as soon as it is
		1009	push @AnyEvent::post_detect, sub { require Coro::AnyEvent };
		1010	}
		1011
		1012	=item AnyEvent::postpone { BLOCK }
		1013
		1014	Arranges for the block to be executed as soon as possible, but not before
		1015	the call itself returns. In practise, the block will be executed just
		1016	before the event loop polls for new events, or shortly afterwards.
		1017
		1018	This function never returns anything (to make the C<return postpone { ...
		1019	}> idiom more useful.
		1020
		1021	To understand the usefulness of this function, consider a function that
		1022	asynchronously does something for you and returns some transaction
		1023	object or guard to let you cancel the operation. For example,
		1024	C<AnyEvent::Socket::tcp_connect>:
		1025
		1026	# start a conenction attempt unless one is active
		1027	$self->{connect_guard} ||= AnyEvent::Socket::tcp_connect "www.example.net", 80, sub {
		1028	delete $self->{connect_guard};
		1029	...
		1030	};
		1031
		1032	Imagine that this function could instantly call the callback, for
		1033	example, because it detects an obvious error such as a negative port
		1034	number. Invoking the callback before the function returns causes problems
		1035	however: the callback will be called and will try to delete the guard
		1036	object. But since the function hasn't returned yet, there is nothing to
		1037	delete. When the function eventually returns it will assign the guard
		1038	object to C<< $self->{connect_guard} >>, where it will likely never be
		1039	deleted, so the program thinks it is still trying to connect.
		1040
		1041	This is where C<AnyEvent::postpone> should be used. Instead of calling the
		1042	callback directly on error:
		1043
		1044	$cb->(undef), return # signal error to callback, BAD!
		1045	if $some_error_condition;
		1046
		1047	It should use C<postpone>:
		1048
		1049	AnyEvent::postpone { $cb->(undef) }, return # signal error to callback, later
		1050	if $some_error_condition;
		1051
		1052	=item AnyEvent::log $level, $msg[, @args]
		1053
		1054	Log the given C<$msg> at the given C<$level>.
		1055
		1056	If L<AnyEvent::Log> is not loaded then this function makes a simple test
		1057	to see whether the message will be logged. If the test succeeds it will
		1058	load AnyEvent::Log and call C<AnyEvent::Log::log> - consequently, look at
		1059	the L<AnyEvent::Log> documentation for details.
		1060
		1061	If the test fails it will simply return. Right now this happens when a
		1062	numerical loglevel is used and it is larger than the level specified via
		1063	C<$ENV{PERL_ANYEVENT_VERBOSE}>.
		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
961	=back	1070	=back
962		1071
963	=head1 WHAT TO DO IN A MODULE	1072	=head1 WHAT TO DO IN A MODULE
964		1073
965	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
…		…
975	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
976	events is to stay interactive.	1085	events is to stay interactive.
977		1086
978	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
979	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
980	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 >>
981	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).
982		1091
983	=head1 WHAT TO DO IN THE MAIN PROGRAM	1092	=head1 WHAT TO DO IN THE MAIN PROGRAM
984		1093
985	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
986	dictate which event model to use.	1095	dictate which event model to use.
987		1096
988	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
989	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
990	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.
991		1102
992	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
993	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
994	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
995	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
996	modules might create watchers when they are loaded, and AnyEvent will	1107	modules might create watchers when they are loaded, and AnyEvent will
997	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
998	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.
999		1110
1000	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
1001	C<AnyEvent::Impl::Perl> module, which gives you similar behaviour	1112	C<AnyEvent::Loop> module, which gives you similar behaviour
1002	everywhere, but letting AnyEvent chose the model is generally better.	1113	everywhere, but letting AnyEvent chose the model is generally better.
1003		1114
1004	=head2 MAINLOOP EMULATION	1115	=head2 MAINLOOP EMULATION
1005		1116
1006	Sometimes (often for short test scripts, or even standalone programs who	1117	Sometimes (often for short test scripts, or even standalone programs who
…		…
1019		1130
1020		1131
1021	=head1 OTHER MODULES	1132	=head1 OTHER MODULES
1022		1133
1023	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
1024	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
1025	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
1026	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 :)
1027		1141
1028	=over 4	1142	=over 4
1029		1143
1030	=item L<AnyEvent::Util>	1144	=item L<AnyEvent::Util>
1031		1145
1032	Contains various utility functions that replace often-used but blocking	1146	Contains various utility functions that replace often-used blocking
1033	functions such as C<inet_aton> by event-/callback-based versions.	1147	functions such as C<inet_aton> with event/callback-based versions.
1034		1148
1035	=item L<AnyEvent::Socket>	1149	=item L<AnyEvent::Socket>
1036		1150
1037	Provides various utility functions for (internet protocol) sockets,	1151	Provides various utility functions for (internet protocol) sockets,
1038	addresses and name resolution. Also functions to create non-blocking tcp	1152	addresses and name resolution. Also functions to create non-blocking tcp
…		…
1040		1154
1041	=item L<AnyEvent::Handle>	1155	=item L<AnyEvent::Handle>
1042		1156
1043	Provide read and write buffers, manages watchers for reads and writes,	1157	Provide read and write buffers, manages watchers for reads and writes,
1044	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
1045	non-blocking SSL/TLS (via L<AnyEvent::TLS>.	1159	non-blocking SSL/TLS (via L<AnyEvent::TLS>).
1046		1160
1047	=item L<AnyEvent::DNS>	1161	=item L<AnyEvent::DNS>
1048		1162
1049	Provides rich asynchronous DNS resolver capabilities.	1163	Provides rich asynchronous DNS resolver capabilities.
1050		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
1051	=item L<AnyEvent::HTTP>	1171	=item L<AnyEvent::AIO>
1052		1172
1053	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
1054	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.
1055		1195
1056	=item L<AnyEvent::HTTPD>	1196	=item L<AnyEvent::HTTPD>
1057		1197
1058	Provides a simple web application server framework.	1198	A simple embedded webserver.
1059		1199
1060	=item L<AnyEvent::FastPing>	1200	=item L<AnyEvent::FastPing>
1061		1201
1062	The fastest ping in the west.	1202	The fastest ping in the west.
1063		1203
1064	=item L<AnyEvent::DBI>
1065
1066	Executes L<DBI> requests asynchronously in a proxy process.
1067
1068	=item L<AnyEvent::AIO>
1069
1070	Truly asynchronous I/O, should be in the toolbox of every event
1071	programmer. AnyEvent::AIO transparently fuses L<IO::AIO> and AnyEvent
1072	together.
1073
1074	=item L<AnyEvent::BDB>
1075
1076	Truly asynchronous Berkeley DB access. AnyEvent::BDB transparently fuses
1077	L<BDB> and AnyEvent together.
1078
1079	=item L<AnyEvent::GPSD>
1080
1081	A non-blocking interface to gpsd, a daemon delivering GPS information.
1082
1083	=item L<AnyEvent::IRC>
1084
1085	AnyEvent based IRC client module family (replacing the older Net::IRC3).
1086
1087	=item L<AnyEvent::XMPP>
1088
1089	AnyEvent based XMPP (Jabber protocol) module family (replacing the older
1090	Net::XMPP2>.
1091
1092	=item L<AnyEvent::IGS>
1093
1094	A non-blocking interface to the Internet Go Server protocol (used by
1095	L<App::IGS>).
1096
1097	=item L<Net::FCP>
1098
1099	AnyEvent-based implementation of the Freenet Client Protocol, birthplace
1100	of AnyEvent.
1101
1102	=item L<Event::ExecFlow>
1103
1104	High level API for event-based execution flow control.
1105
1106	=item L<Coro>	1204	=item L<Coro>
1107		1205
1108	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	};
1109		1219
1110	=back	1220	=back
1111		1221
1112	=cut	1222	=cut
1113		1223
1114	package AnyEvent;	1224	package AnyEvent;
1115		1225
1116	# basically a tuned-down version of common::sense	1226	# basically a tuned-down version of common::sense
1117	sub common_sense {	1227	sub common_sense {
1118	# from common:.sense 1.0	1228	# from common:.sense 3.4
1119	${^WARNING_BITS} = "\xfc\x3f\xf3\x00\x0f\xf3\xcf\xc0\xf3\xfc\x33\x03";	1229	${^WARNING_BITS} ^= ${^WARNING_BITS} ^ "\x3c\x3f\x33\x00\x0f\xf0\x0f\xc0\xf0\xfc\x33\x00";
1120	# use strict vars subs	1230	# use strict vars subs - NO UTF-8, as Util.pm doesn't like this atm. (uts46data.pl)
1121	$^H |= 0x00000600;	1231	$^H |= 0x00000600;
1122	}	1232	}
1123		1233
1124	BEGIN { AnyEvent::common_sense }	1234	BEGIN { AnyEvent::common_sense }
1125		1235
1126	use Carp ();	1236	use Carp ();
1127		1237
1128	our $VERSION = '5.202';	1238	our $VERSION = '6.02';
1129	our $MODEL;	1239	our $MODEL;
1130
1131	our $AUTOLOAD;
1132	our @ISA;	1240	our @ISA;
1133
1134	our @REGISTRY;	1241	our @REGISTRY;
1135
1136	our $WIN32;
1137
1138	our $VERBOSE;	1242	our $VERBOSE;
		1243	our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred
		1244	our $MAX_SIGNAL_LATENCY = $ENV{PERL_ANYEVENT_MAX_SIGNAL_LATENCY} || 10; # executes after the BEGIN block below (tainting!)
1139		1245
1140	BEGIN {	1246	BEGIN {
1141	eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }";	1247	require "AnyEvent/constants.pl";
		1248
1142	eval "sub TAINT(){ " . (${^TAINT}*1) . " }";	1249	eval "sub TAINT (){" . (${^TAINT}*1) . "}";
1143		1250
1144	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}	1251	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}
1145	if ${^TAINT};	1252	if ${^TAINT};
1146		1253
1147	$VERBOSE = $ENV{PERL_ANYEVENT_VERBOSE}*1;	1254	$ENV{"PERL_ANYEVENT_$_"} = $ENV{"AE_$_"}
		1255	for grep s/^AE_// && !exists $ENV{"PERL_ANYEVENT_$_"}, keys %ENV;
1148		1256
1149	}	1257	@ENV{grep /^PERL_ANYEVENT_/, keys %ENV} = ()
		1258	if ${^TAINT};
1150		1259
1151	our $MAX_SIGNAL_LATENCY = 10;	1260	# $ENV{PERL_ANYEVENT_xxx} now valid
1152		1261
1153	our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred	1262	$VERBOSE = length $ENV{PERL_ANYEVENT_VERBOSE} ? $ENV{PERL_ANYEVENT_VERBOSE}*1 : 4;
1154		1263
1155	{
1156	my $idx;	1264	my $idx;
1157	$PROTOCOL{$_} = ++$idx	1265	$PROTOCOL{$_} = ++$idx
1158	for reverse split /\s*,\s*/,	1266	for reverse split /\s*,\s*/,
1159	$ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";	1267	$ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";
1160	}	1268	}
1161		1269
		1270	our @post_detect;
		1271
		1272	sub post_detect(&) {
		1273	my ($cb) = @_;
		1274
		1275	push @post_detect, $cb;
		1276
		1277	defined wantarray
		1278	? bless \$cb, "AnyEvent::Util::postdetect"
		1279	: ()
		1280	}
		1281
		1282	sub AnyEvent::Util::postdetect::DESTROY {
		1283	@post_detect = grep $_ != ${$_[0]}, @post_detect;
		1284	}
		1285
		1286	our $POSTPONE_W;
		1287	our @POSTPONE;
		1288
		1289	sub _postpone_exec {
		1290	undef $POSTPONE_W;
		1291
		1292	&{ shift @POSTPONE }
		1293	while @POSTPONE;
		1294	}
		1295
		1296	sub postpone(&) {
		1297	push @POSTPONE, shift;
		1298
		1299	$POSTPONE_W ||= AE::timer (0, 0, \&_postpone_exec);
		1300
		1301	()
		1302	}
		1303
		1304	sub log($$;@) {
		1305	# only load the big bloated module when we actually are about to log something
		1306	if ($_[0] <= ($VERBOSE || 1)) { # also catches non-numeric levels(!) and fatal
		1307	local ($!, $@);
		1308	require AnyEvent::Log; # among other things, sets $VERBOSE to 9
		1309	# AnyEvent::Log overwrites this function
		1310	goto &log;
		1311	}
		1312
		1313	0 # not logged
		1314	}
		1315
		1316	sub logger($;$) {
		1317	package AnyEvent::Log;
		1318
		1319	my ($level, $renabled) = @_;
		1320
		1321	$$renabled = $level <= $VERBOSE;
		1322
		1323	my $pkg = (caller)[0];
		1324
		1325	my $logger = [$pkg, $level, $renabled];
		1326
		1327	our %LOGGER;
		1328	$LOGGER{$logger+0} = $logger;
		1329
		1330	return unless defined wantarray;
		1331
		1332	require AnyEvent::Util;
		1333	my $guard = AnyEvent::Util::guard (sub {
		1334	# "clean up"
		1335	delete $LOGGER{$logger+0};
		1336	});
		1337
		1338	sub {
		1339	return 0 unless $$renabled;
		1340
		1341	$guard if 0; # keep guard alive, but don't cause runtime overhead
		1342	require AnyEvent::Log unless $AnyEvent::Log::VERSION;
		1343	package AnyEvent::Log;
		1344	_log ($logger->[0], $level, @_) # logger->[0] has been converted at load time
		1345	}
		1346	}
		1347
		1348	if (length $ENV{PERL_ANYEVENT_LOG}) {
		1349	require AnyEvent::Log; # AnyEvent::Log does the thing for us
		1350	}
		1351
1162	my @models = (	1352	our @models = (
1163	[EV:: => AnyEvent::Impl::EV:: , 1],	1353	[EV:: => AnyEvent::Impl::EV::],
1164	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl:: , 1],	1354	[AnyEvent::Loop:: => AnyEvent::Impl::Perl::],
1165	# everything below here will not (normally) be autoprobed	1355	# everything below here will not (normally) be autoprobed
1166	# as the pureperl backend should work everywhere	1356	# as the pure perl backend should work everywhere
1167	# and is usually faster	1357	# and is usually faster
		1358	[Irssi:: => AnyEvent::Impl::Irssi::], # Irssi has a bogus "Event" package, so msut be near the top
1168	[Event:: => AnyEvent::Impl::Event::, 1],	1359	[Event:: => AnyEvent::Impl::Event::], # slow, stable
1169	[Glib:: => AnyEvent::Impl::Glib:: , 1], # becomes extremely slow with many watchers	1360	[Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers
		1361	# everything below here should not be autoloaded
1170	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy	1362	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
1171	[Irssi:: => AnyEvent::Impl::Irssi::], # Irssi has a bogus "Event" package
1172	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles	1363	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
1173	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program	1364	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program
1174	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza	1365	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
1175	[Wx:: => AnyEvent::Impl::POE::],	1366	[Wx:: => AnyEvent::Impl::POE::],
1176	[Prima:: => AnyEvent::Impl::POE::],	1367	[Prima:: => AnyEvent::Impl::POE::],
1177	# IO::Async is just too broken - we would need workarounds for its	1368	[IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # a bitch to autodetect
1178	# byzantine signal and broken child handling, among others.	1369	[Cocoa::EventLoop:: => AnyEvent::Impl::Cocoa::],
1179	# IO::Async is rather hard to detect, as it doesn't have any	1370	[FLTK:: => AnyEvent::Impl::FLTK::],
1180	# obvious default class.
1181	[IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program
1182	[IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program
1183	[IO::Async::Notifier:: => AnyEvent::Impl::IOAsync::], # requires special main program
1184	[AnyEvent::Impl::IOAsync:: => AnyEvent::Impl::IOAsync::], # requires special main program
1185	);	1371	);
1186		1372
1187	our %method = map +($_ => 1),	1373	our @isa_hook;
		1374
		1375	sub _isa_set {
		1376	my @pkg = ("AnyEvent", (map $_->[0], grep defined, @isa_hook), $MODEL);
		1377
		1378	@{"$pkg[$_-1]::ISA"} = $pkg[$_]
		1379	for 1 .. $#pkg;
		1380
		1381	grep $_ && $_->[1], @isa_hook
		1382	and AE::_reset ();
		1383	}
		1384
		1385	# used for hooking AnyEvent::Strict and AnyEvent::Debug::Wrap into the class hierarchy
		1386	sub _isa_hook($$;$) {
		1387	my ($i, $pkg, $reset_ae) = @_;
		1388
		1389	$isa_hook[$i] = $pkg ? [$pkg, $reset_ae] : undef;
		1390
		1391	_isa_set;
		1392	}
		1393
		1394	# all autoloaded methods reserve the complete glob, not just the method slot.
		1395	# due to bugs in perls method cache implementation.
1188	qw(io timer time now now_update signal child idle condvar one_event DESTROY);	1396	our @methods = qw(io timer time now now_update signal child idle condvar);
1189		1397
1190	our @post_detect;
1191
1192	sub post_detect(&) {	1398	sub detect() {
1193	my ($cb) = @_;	1399	return $MODEL if $MODEL; # some programs keep references to detect
1194		1400
1195	if ($MODEL) {	1401	# IO::Async::Loop::AnyEvent is extremely evil, refuse to work with it
1196	$cb->();	1402	# the author knows about the problems and what it does to AnyEvent as a whole
		1403	# (and the ability of others to use AnyEvent), but simply wants to abuse AnyEvent
		1404	# anyway.
		1405	AnyEvent::log fatal => "AnyEvent: IO::Async::Loop::AnyEvent detected - this module is broken by design,\n"
		1406	. "abuses internals and breaks AnyEvent, will not continue."
		1407	if exists $INC{"IO/Async/Loop/AnyEvent.pm"};
1197		1408
1198	undef	1409	local $!; # for good measure
		1410	local $SIG{__DIE__}; # we use eval
		1411
		1412	# free some memory
		1413	*detect = sub () { $MODEL };
		1414	# undef &func doesn't correctly update the method cache. grmbl.
		1415	# so we delete the whole glob. grmbl.
		1416	# otoh, perl doesn't let me undef an active usb, but it lets me free
		1417	# a glob with an active sub. hrm. i hope it works, but perl is
		1418	# usually buggy in this department. sigh.
		1419	delete @{"AnyEvent::"}{@methods};
		1420	undef @methods;
		1421
		1422	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z0-9:]+)$/) {
		1423	my $model = $1;
		1424	$model = "AnyEvent::Impl::$model" unless $model =~ s/::$//;
		1425	if (eval "require $model") {
		1426	AnyEvent::log 7 => "loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.";
		1427	$MODEL = $model;
1199	} else {	1428	} else {
1200	push @post_detect, $cb;	1429	AnyEvent::log 4 => "unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@";
1201		1430	}
1202	defined wantarray
1203	? bless \$cb, "AnyEvent::Util::postdetect"
1204	: ()
1205	}	1431	}
1206	}
1207		1432
1208	sub AnyEvent::Util::postdetect::DESTROY {	1433	# check for already loaded models
1209	@post_detect = grep $_ != ${$_[0]}, @post_detect;
1210	}
1211
1212	sub detect() {
1213	unless ($MODEL) {	1434	unless ($MODEL) {
1214	local $SIG{__DIE__};	1435	for (@REGISTRY, @models) {
1215		1436	my ($package, $model) = @$_;
1216	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {	1437	if (${"$package\::VERSION"} > 0) {
1217	my $model = "AnyEvent::Impl::$1";
1218	if (eval "require $model") {	1438	if (eval "require $model") {
		1439	AnyEvent::log 7 => "autodetected model '$model', using it.";
1219	$MODEL = $model;	1440	$MODEL = $model;
1220	warn "AnyEvent: loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.\n" if $VERBOSE >= 2;	1441	last;
1221	} else {	1442	}
1222	warn "AnyEvent: unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@" if $VERBOSE;
1223	}	1443	}
1224	}	1444	}
1225		1445
1226	# check for already loaded models
1227	unless ($MODEL) {	1446	unless ($MODEL) {
		1447	# try to autoload a model
1228	for (@REGISTRY, @models) {	1448	for (@REGISTRY, @models) {
1229	my ($package, $model) = @$_;	1449	my ($package, $model) = @$_;
		1450	if (
		1451	eval "require $package"
1230	if (${"$package\::VERSION"} > 0) {	1452	and ${"$package\::VERSION"} > 0
1231	if (eval "require $model") {	1453	and eval "require $model"
		1454	) {
		1455	AnyEvent::log 7 => "autoloaded model '$model', using it.";
1232	$MODEL = $model;	1456	$MODEL = $model;
1233	warn "AnyEvent: autodetected model '$model', using it.\n" if $VERBOSE >= 2;
1234	last;	1457	last;
1235	}
1236	}	1458	}
1237	}	1459	}
1238		1460
1239	unless ($MODEL) {
1240	# try to autoload a model
1241	for (@REGISTRY, @models) {
1242	my ($package, $model, $autoload) = @$_;
1243	if (
1244	$autoload
1245	and eval "require $package"
1246	and ${"$package\::VERSION"} > 0
1247	and eval "require $model"
1248	) {
1249	$MODEL = $model;
1250	warn "AnyEvent: autoloaded model '$model', using it.\n" if $VERBOSE >= 2;
1251	last;
1252	}
1253	}
1254
1255	$MODEL	1461	$MODEL
1256	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.\n";	1462	or AnyEvent::log fatal => "AnyEvent: backend autodetection failed - did you properly install AnyEvent?";
1257	}
1258	}	1463	}
1259
1260	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
1261
1262	unshift @ISA, $MODEL;
1263
1264	require AnyEvent::Strict if $ENV{PERL_ANYEVENT_STRICT};
1265
1266	(shift @post_detect)->() while @post_detect;
1267	}	1464	}
1268		1465
		1466	# free memory only needed for probing
		1467	undef @models;
		1468	undef @REGISTRY;
		1469
		1470	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
		1471
		1472	# now nuke some methods that are overridden by the backend.
		1473	# SUPER usage is not allowed in these.
		1474	for (qw(time signal child idle)) {
		1475	undef &{"AnyEvent::Base::$_"}
		1476	if defined &{"$MODEL\::$_"};
		1477	}
		1478
		1479	_isa_set;
		1480
		1481	# we're officially open!
		1482
		1483	if ($ENV{PERL_ANYEVENT_STRICT}) {
		1484	require AnyEvent::Strict;
		1485	}
		1486
		1487	if ($ENV{PERL_ANYEVENT_DEBUG_WRAP}) {
		1488	require AnyEvent::Debug;
		1489	AnyEvent::Debug::wrap ($ENV{PERL_ANYEVENT_DEBUG_WRAP});
		1490	}
		1491
		1492	if (length $ENV{PERL_ANYEVENT_DEBUG_SHELL}) {
		1493	require AnyEvent::Socket;
		1494	require AnyEvent::Debug;
		1495
		1496	my $shell = $ENV{PERL_ANYEVENT_DEBUG_SHELL};
		1497	$shell =~ s/\$\$/$$/g;
		1498
		1499	my ($host, $service) = AnyEvent::Socket::parse_hostport ($shell);
		1500	$AnyEvent::Debug::SHELL = AnyEvent::Debug::shell ($host, $service);
		1501	}
		1502
		1503	# now the anyevent environment is set up as the user told us to, so
		1504	# call the actual user code - post detects
		1505
		1506	(shift @post_detect)->() while @post_detect;
		1507	undef @post_detect;
		1508
		1509	*post_detect = sub(&) {
		1510	shift->();
		1511
		1512	undef
		1513	};
		1514
1269	$MODEL	1515	$MODEL
1270	}	1516	}
1271		1517
1272	sub AUTOLOAD {	1518	for my $name (@methods) {
1273	(my $func = $AUTOLOAD) =~ s/.*://;	1519	*$name = sub {
1274		1520	detect;
1275	$method{$func}	1521	# we use goto because
1276	or Carp::croak "$func: not a valid method for AnyEvent objects";	1522	# a) it makes the thunk more transparent
1277		1523	# b) it allows us to delete the thunk later
1278	detect unless $MODEL;	1524	goto &{ UNIVERSAL::can AnyEvent => "SUPER::$name" }
1279		1525	};
1280	my $class = shift;
1281	$class->$func (@_);
1282	}	1526	}
1283		1527
1284	# utility function to dup a filehandle. this is used by many backends	1528	# utility function to dup a filehandle. this is used by many backends
1285	# to support binding more than one watcher per filehandle (they usually	1529	# to support binding more than one watcher per filehandle (they usually
1286	# allow only one watcher per fd, so we dup it to get a different one).	1530	# allow only one watcher per fd, so we dup it to get a different one).
…		…
1300		1544
1301	=head1 SIMPLIFIED AE API	1545	=head1 SIMPLIFIED AE API
1302		1546
1303	Starting with version 5.0, AnyEvent officially supports a second, much	1547	Starting with version 5.0, AnyEvent officially supports a second, much
1304	simpler, API that is designed to reduce the calling, typing and memory	1548	simpler, API that is designed to reduce the calling, typing and memory
1305	overhead.	1549	overhead by using function call syntax and a fixed number of parameters.
1306		1550
1307	See the L<AE> manpage for details.	1551	See the L<AE> manpage for details.
1308		1552
1309	=cut	1553	=cut
1310		1554
1311	package AE;	1555	package AE;
1312		1556
1313	our $VERSION = $AnyEvent::VERSION;	1557	our $VERSION = $AnyEvent::VERSION;
1314		1558
		1559	sub _reset() {
		1560	eval q{
		1561	# fall back to the main API by default - backends and AnyEvent::Base
		1562	# implementations can overwrite these.
		1563
1315	sub io($$$) {	1564	sub io($$$) {
1316	AnyEvent->io (fh => $_[0], poll => $_[1] ? "w" : "r", cb => $_[2])	1565	AnyEvent->io (fh => $_[0], poll => $_[1] ? "w" : "r", cb => $_[2])
1317	}	1566	}
1318		1567
1319	sub timer($$$) {	1568	sub timer($$$) {
1320	AnyEvent->timer (after => $_[0], interval => $_[1], cb => $_[2])	1569	AnyEvent->timer (after => $_[0], interval => $_[1], cb => $_[2])
1321	}	1570	}
1322		1571
1323	sub signal($$) {	1572	sub signal($$) {
1324	AnyEvent->signal (signal => $_[0], cb => $_[1])	1573	AnyEvent->signal (signal => $_[0], cb => $_[1])
1325	}	1574	}
1326		1575
1327	sub child($$) {	1576	sub child($$) {
1328	AnyEvent->child (pid => $_[0], cb => $_[1])	1577	AnyEvent->child (pid => $_[0], cb => $_[1])
1329	}	1578	}
1330		1579
1331	sub idle($) {	1580	sub idle($) {
1332	AnyEvent->idle (cb => $_[0])	1581	AnyEvent->idle (cb => $_[0]);
1333	}	1582	}
1334		1583
1335	sub cv(;&) {	1584	sub cv(;&) {
1336	AnyEvent->condvar (@_ ? (cb => $_[0]) : ())	1585	AnyEvent->condvar (@_ ? (cb => $_[0]) : ())
1337	}	1586	}
1338		1587
1339	sub now() {	1588	sub now() {
1340	AnyEvent->now	1589	AnyEvent->now
1341	}	1590	}
1342		1591
1343	sub now_update() {	1592	sub now_update() {
1344	AnyEvent->now_update	1593	AnyEvent->now_update
1345	}	1594	}
1346		1595
1347	sub time() {	1596	sub time() {
1348	AnyEvent->time	1597	AnyEvent->time
		1598	}
		1599
		1600	*postpone = \&AnyEvent::postpone;
		1601	*log = \&AnyEvent::log;
		1602	};
		1603	die if $@;
1349	}	1604	}
		1605
		1606	BEGIN { _reset }
1350		1607
1351	package AnyEvent::Base;	1608	package AnyEvent::Base;
1352		1609
1353	# default implementations for many methods	1610	# default implementations for many methods
1354		1611
1355	sub _time() {	1612	sub time {
		1613	eval q{ # poor man's autoloading {}
1356	# probe for availability of Time::HiRes	1614	# probe for availability of Time::HiRes
1357	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {	1615	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {
1358	warn "AnyEvent: using Time::HiRes for sub-second timing accuracy.\n" if $VERBOSE >= 8;	1616	*time = sub { Time::HiRes::time () };
1359	*_time = \&Time::HiRes::time;	1617	*AE::time = \& Time::HiRes::time ;
		1618	*now = \&time;
		1619	AnyEvent::log 8 => "AnyEvent: using Time::HiRes for sub-second timing accuracy.";
1360	# if (eval "use POSIX (); (POSIX::times())...	1620	# if (eval "use POSIX (); (POSIX::times())...
1361	} else {	1621	} else {
		1622	*time = sub { CORE::time };
		1623	*AE::time = sub (){ CORE::time };
		1624	*now = \&time;
1362	warn "AnyEvent: using built-in time(), WARNING, no sub-second resolution!\n" if $VERBOSE;	1625	AnyEvent::log 3 => "using built-in time(), WARNING, no sub-second resolution!";
1363	*_time = sub { time }; # epic fail	1626	}
1364	}	1627	};
		1628	die if $@;
1365		1629
1366	&_time	1630	&time
1367	}	1631	}
1368		1632
1369	sub time { _time }	1633	*now = \&time;
1370	sub now { _time }
1371	sub now_update { }	1634	sub now_update { }
1372		1635
		1636	sub _poll {
		1637	Carp::croak "$AnyEvent::MODEL does not support blocking waits. Caught";
		1638	}
		1639
1373	# default implementation for ->condvar	1640	# default implementation for ->condvar
		1641	# in fact, the default should not be overwritten
1374		1642
1375	sub condvar {	1643	sub condvar {
		1644	eval q{ # poor man's autoloading {}
		1645	*condvar = sub {
1376	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"	1646	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"
		1647	};
		1648
		1649	*AE::cv = sub (;&) {
		1650	bless { @_ ? (_ae_cb => shift) : () }, "AnyEvent::CondVar"
		1651	};
		1652	};
		1653	die if $@;
		1654
		1655	&condvar
1377	}	1656	}
1378		1657
1379	# default implementation for ->signal	1658	# default implementation for ->signal
1380		1659
1381	our $HAVE_ASYNC_INTERRUPT;	1660	our $HAVE_ASYNC_INTERRUPT;
…		…
1390		1669
1391	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);	1670	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);
1392	our (%SIG_ASY, %SIG_ASY_W);	1671	our (%SIG_ASY, %SIG_ASY_W);
1393	our ($SIG_COUNT, $SIG_TW);	1672	our ($SIG_COUNT, $SIG_TW);
1394		1673
1395	sub _signal_exec {
1396	$HAVE_ASYNC_INTERRUPT
1397	? $SIGPIPE_R->drain
1398	: sysread $SIGPIPE_R, (my $dummy), 9;
1399
1400	while (%SIG_EV) {
1401	for (keys %SIG_EV) {
1402	delete $SIG_EV{$_};
1403	$_->() for values %{ $SIG_CB{$_} || {} };
1404	}
1405	}
1406	}
1407
1408	# install a dummy wakeup watcher to reduce signal catching latency	1674	# install a dummy wakeup watcher to reduce signal catching latency
		1675	# used by Impls
1409	sub _sig_add() {	1676	sub _sig_add() {
1410	unless ($SIG_COUNT++) {	1677	unless ($SIG_COUNT++) {
1411	# try to align timer on a full-second boundary, if possible	1678	# try to align timer on a full-second boundary, if possible
1412	my $NOW = AE::now;	1679	my $NOW = AE::now;
1413		1680
…		…
1423	undef $SIG_TW	1690	undef $SIG_TW
1424	unless --$SIG_COUNT;	1691	unless --$SIG_COUNT;
1425	}	1692	}
1426		1693
1427	our $_sig_name_init; $_sig_name_init = sub {	1694	our $_sig_name_init; $_sig_name_init = sub {
1428	eval q{ # poor man's autoloading	1695	eval q{ # poor man's autoloading {}
1429	undef $_sig_name_init;	1696	undef $_sig_name_init;
1430		1697
1431	if (_have_async_interrupt) {	1698	if (_have_async_interrupt) {
1432	*sig2num = \&Async::Interrupt::sig2num;	1699	*sig2num = \&Async::Interrupt::sig2num;
1433	*sig2name = \&Async::Interrupt::sig2name;	1700	*sig2name = \&Async::Interrupt::sig2name;
…		…
1457		1724
1458	sub signal {	1725	sub signal {
1459	eval q{ # poor man's autoloading {}	1726	eval q{ # poor man's autoloading {}
1460	# probe for availability of Async::Interrupt	1727	# probe for availability of Async::Interrupt
1461	if (_have_async_interrupt) {	1728	if (_have_async_interrupt) {
1462	warn "AnyEvent: using Async::Interrupt for race-free signal handling.\n" if $VERBOSE >= 8;	1729	AnyEvent::log 8 => "using Async::Interrupt for race-free signal handling.";
1463		1730
1464	$SIGPIPE_R = new Async::Interrupt::EventPipe;	1731	$SIGPIPE_R = new Async::Interrupt::EventPipe;
1465	$SIG_IO = AE::io $SIGPIPE_R->fileno, 0, \&_signal_exec;	1732	$SIG_IO = AE::io $SIGPIPE_R->fileno, 0, \&_signal_exec;
1466		1733
1467	} else {	1734	} else {
1468	warn "AnyEvent: using emulated perl signal handling with latency timer.\n" if $VERBOSE >= 8;	1735	AnyEvent::log 8 => "using emulated perl signal handling with latency timer.";
1469
1470	require Fcntl;
1471		1736
1472	if (AnyEvent::WIN32) {	1737	if (AnyEvent::WIN32) {
1473	require AnyEvent::Util;	1738	require AnyEvent::Util;
1474		1739
1475	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();	1740	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
1476	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R, 1) if $SIGPIPE_R;	1741	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R, 1) if $SIGPIPE_R;
1477	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W, 1) if $SIGPIPE_W; # just in case	1742	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W, 1) if $SIGPIPE_W; # just in case
1478	} else {	1743	} else {
1479	pipe $SIGPIPE_R, $SIGPIPE_W;	1744	pipe $SIGPIPE_R, $SIGPIPE_W;
1480	fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R;	1745	fcntl $SIGPIPE_R, AnyEvent::F_SETFL, AnyEvent::O_NONBLOCK if $SIGPIPE_R;
1481	fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case	1746	fcntl $SIGPIPE_W, AnyEvent::F_SETFL, AnyEvent::O_NONBLOCK if $SIGPIPE_W; # just in case
1482		1747
1483	# not strictly required, as $^F is normally 2, but let's make sure...	1748	# not strictly required, as $^F is normally 2, but let's make sure...
1484	fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;	1749	fcntl $SIGPIPE_R, AnyEvent::F_SETFD, AnyEvent::FD_CLOEXEC;
1485	fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;	1750	fcntl $SIGPIPE_W, AnyEvent::F_SETFD, AnyEvent::FD_CLOEXEC;
1486	}	1751	}
1487		1752
1488	$SIGPIPE_R	1753	$SIGPIPE_R
1489	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";	1754	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";
1490		1755
1491	$SIG_IO = AE::io $SIGPIPE_R, 0, \&_signal_exec;	1756	$SIG_IO = AE::io $SIGPIPE_R, 0, \&_signal_exec;
1492	}	1757	}
1493		1758
1494	*signal = sub {	1759	*signal = $HAVE_ASYNC_INTERRUPT
		1760	? sub {
1495	my (undef, %arg) = @_;	1761	my (undef, %arg) = @_;
1496		1762
1497	my $signal = uc $arg{signal}
1498	or Carp::croak "required option 'signal' is missing";
1499
1500	if ($HAVE_ASYNC_INTERRUPT) {
1501	# async::interrupt	1763	# async::interrupt
1502
1503	$signal = sig2num $signal;	1764	my $signal = sig2num $arg{signal};
1504	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};	1765	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
1505		1766
1506	$SIG_ASY{$signal} ||= new Async::Interrupt	1767	$SIG_ASY{$signal} ||= new Async::Interrupt
1507	cb => sub { undef $SIG_EV{$signal} },	1768	cb => sub { undef $SIG_EV{$signal} },
1508	signal => $signal,	1769	signal => $signal,
1509	pipe => [$SIGPIPE_R->filenos],	1770	pipe => [$SIGPIPE_R->filenos],
1510	pipe_autodrain => 0,	1771	pipe_autodrain => 0,
1511	;	1772	;
1512		1773
1513	} else {	1774	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
		1775	}
		1776	: sub {
		1777	my (undef, %arg) = @_;
		1778
1514	# pure perl	1779	# pure perl
1515
1516	# AE::Util has been loaded in signal
1517	$signal = sig2name $signal;	1780	my $signal = sig2name $arg{signal};
1518	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};	1781	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
1519		1782
1520	$SIG{$signal} ||= sub {	1783	$SIG{$signal} ||= sub {
1521	local $!;	1784	local $!;
1522	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;	1785	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;
1523	undef $SIG_EV{$signal};	1786	undef $SIG_EV{$signal};
1524	};	1787	};
1525		1788
1526	# can't do signal processing without introducing races in pure perl,	1789	# can't do signal processing without introducing races in pure perl,
1527	# so limit the signal latency.	1790	# so limit the signal latency.
1528	_sig_add;	1791	_sig_add;
1529	}
1530		1792
1531	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"	1793	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
		1794	}
1532	};	1795	;
1533		1796
1534	*AnyEvent::Base::signal::DESTROY = sub {	1797	*AnyEvent::Base::signal::DESTROY = sub {
1535	my ($signal, $cb) = @{$_[0]};	1798	my ($signal, $cb) = @{$_[0]};
1536		1799
1537	_sig_del;	1800	_sig_del;
…		…
1544	# print weird messages, or just unconditionally exit	1807	# print weird messages, or just unconditionally exit
1545	# instead of getting the default action.	1808	# instead of getting the default action.
1546	undef $SIG{$signal}	1809	undef $SIG{$signal}
1547	unless keys %{ $SIG_CB{$signal} };	1810	unless keys %{ $SIG_CB{$signal} };
1548	};	1811	};
		1812
		1813	*_signal_exec = sub {
		1814	$HAVE_ASYNC_INTERRUPT
		1815	? $SIGPIPE_R->drain
		1816	: sysread $SIGPIPE_R, (my $dummy), 9;
		1817
		1818	while (%SIG_EV) {
		1819	for (keys %SIG_EV) {
		1820	delete $SIG_EV{$_};
		1821	&$_ for values %{ $SIG_CB{$_} || {} };
		1822	}
		1823	}
		1824	};
1549	};	1825	};
1550	die if $@;	1826	die if $@;
		1827
1551	&signal	1828	&signal
1552	}	1829	}
1553		1830
1554	# default implementation for ->child	1831	# default implementation for ->child
1555		1832
1556	our %PID_CB;	1833	our %PID_CB;
1557	our $CHLD_W;	1834	our $CHLD_W;
1558	our $CHLD_DELAY_W;	1835	our $CHLD_DELAY_W;
1559	our $WNOHANG;
1560		1836
		1837	# used by many Impl's
1561	sub _emit_childstatus($$) {	1838	sub _emit_childstatus($$) {
1562	my (undef, $rpid, $rstatus) = @_;	1839	my (undef, $rpid, $rstatus) = @_;
1563		1840
1564	$_->($rpid, $rstatus)	1841	$_->($rpid, $rstatus)
1565	for values %{ $PID_CB{$rpid} || {} },	1842	for values %{ $PID_CB{$rpid} || {} },
1566	values %{ $PID_CB{0} || {} };	1843	values %{ $PID_CB{0} || {} };
1567	}	1844	}
1568		1845
1569	sub _sigchld {
1570	my $pid;
1571
1572	AnyEvent->_emit_childstatus ($pid, $?)
1573	while ($pid = waitpid -1, $WNOHANG) > 0;
1574	}
1575
1576	sub child {	1846	sub child {
		1847	eval q{ # poor man's autoloading {}
		1848	*_sigchld = sub {
		1849	my $pid;
		1850
		1851	AnyEvent->_emit_childstatus ($pid, $?)
		1852	while ($pid = waitpid -1, WNOHANG) > 0;
		1853	};
		1854
		1855	*child = sub {
1577	my (undef, %arg) = @_;	1856	my (undef, %arg) = @_;
1578		1857
1579	defined (my $pid = $arg{pid} + 0)	1858	my $pid = $arg{pid};
1580	or Carp::croak "required option 'pid' is missing";	1859	my $cb = $arg{cb};
1581		1860
1582	$PID_CB{$pid}{$arg{cb}} = $arg{cb};	1861	$PID_CB{$pid}{$cb+0} = $cb;
1583		1862
1584	# WNOHANG is almost cetrainly 1 everywhere
1585	$WNOHANG ||= $^O =~ /^(?:openbsd|netbsd|linux|freebsd|cygwin|MSWin32)$/
1586	? 1
1587	: eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1;
1588
1589	unless ($CHLD_W) {	1863	unless ($CHLD_W) {
1590	$CHLD_W = AE::signal CHLD => \&_sigchld;	1864	$CHLD_W = AE::signal CHLD => \&_sigchld;
1591	# child could be a zombie already, so make at least one round	1865	# child could be a zombie already, so make at least one round
1592	&_sigchld;	1866	&_sigchld;
1593	}	1867	}
1594		1868
1595	bless [$pid, $arg{cb}], "AnyEvent::Base::child"	1869	bless [$pid, $cb+0], "AnyEvent::Base::child"
1596	}	1870	};
1597		1871
1598	sub AnyEvent::Base::child::DESTROY {	1872	*AnyEvent::Base::child::DESTROY = sub {
1599	my ($pid, $cb) = @{$_[0]};	1873	my ($pid, $icb) = @{$_[0]};
1600		1874
1601	delete $PID_CB{$pid}{$cb};	1875	delete $PID_CB{$pid}{$icb};
1602	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };	1876	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };
1603		1877
1604	undef $CHLD_W unless keys %PID_CB;	1878	undef $CHLD_W unless keys %PID_CB;
		1879	};
		1880	};
		1881	die if $@;
		1882
		1883	&child
1605	}	1884	}
1606		1885
1607	# idle emulation is done by simply using a timer, regardless	1886	# idle emulation is done by simply using a timer, regardless
1608	# of whether the process is idle or not, and not letting	1887	# of whether the process is idle or not, and not letting
1609	# the callback use more than 50% of the time.	1888	# the callback use more than 50% of the time.
1610	sub idle {	1889	sub idle {
		1890	eval q{ # poor man's autoloading {}
		1891	*idle = sub {
1611	my (undef, %arg) = @_;	1892	my (undef, %arg) = @_;
1612		1893
1613	my ($cb, $w, $rcb) = $arg{cb};	1894	my ($cb, $w, $rcb) = $arg{cb};
1614		1895
1615	$rcb = sub {	1896	$rcb = sub {
1616	if ($cb) {	1897	if ($cb) {
1617	$w = _time;	1898	$w = AE::time;
1618	&$cb;	1899	&$cb;
1619	$w = _time - $w;	1900	$w = AE::time - $w;
1620		1901
1621	# never use more then 50% of the time for the idle watcher,	1902	# never use more then 50% of the time for the idle watcher,
1622	# within some limits	1903	# within some limits
1623	$w = 0.0001 if $w < 0.0001;	1904	$w = 0.0001 if $w < 0.0001;
1624	$w = 5 if $w > 5;	1905	$w = 5 if $w > 5;
1625		1906
1626	$w = AE::timer $w, 0, $rcb;	1907	$w = AE::timer $w, 0, $rcb;
1627	} else {	1908	} else {
1628	# clean up...	1909	# clean up...
1629	undef $w;	1910	undef $w;
1630	undef $rcb;	1911	undef $rcb;
		1912	}
		1913	};
		1914
		1915	$w = AE::timer 0.05, 0, $rcb;
		1916
		1917	bless \\$cb, "AnyEvent::Base::idle"
1631	}	1918	};
		1919
		1920	*AnyEvent::Base::idle::DESTROY = sub {
		1921	undef $${$_[0]};
		1922	};
1632	};	1923	};
		1924	die if $@;
1633		1925
1634	$w = AE::timer 0.05, 0, $rcb;	1926	&idle
1635
1636	bless \\$cb, "AnyEvent::Base::idle"
1637	}
1638
1639	sub AnyEvent::Base::idle::DESTROY {
1640	undef $${$_[0]};
1641	}	1927	}
1642		1928
1643	package AnyEvent::CondVar;	1929	package AnyEvent::CondVar;
1644		1930
1645	our @ISA = AnyEvent::CondVar::Base::;	1931	our @ISA = AnyEvent::CondVar::Base::;
		1932
		1933	# only to be used for subclassing
		1934	sub new {
		1935	my $class = shift;
		1936	bless AnyEvent->condvar (@_), $class
		1937	}
1646		1938
1647	package AnyEvent::CondVar::Base;	1939	package AnyEvent::CondVar::Base;
1648		1940
1649	#use overload	1941	#use overload
1650	# '&{}' => sub { my $self = shift; sub { $self->send (@_) } },	1942	# '&{}' => sub { my $self = shift; sub { $self->send (@_) } },
…		…
1660		1952
1661	sub _send {	1953	sub _send {
1662	# nop	1954	# nop
1663	}	1955	}
1664		1956
		1957	sub _wait {
		1958	AnyEvent->_poll until $_[0]{_ae_sent};
		1959	}
		1960
1665	sub send {	1961	sub send {
1666	my $cv = shift;	1962	my $cv = shift;
1667	$cv->{_ae_sent} = [@_];	1963	$cv->{_ae_sent} = [@_];
1668	(delete $cv->{_ae_cb})->($cv) if $cv->{_ae_cb};	1964	(delete $cv->{_ae_cb})->($cv) if $cv->{_ae_cb};
1669	$cv->_send;	1965	$cv->_send;
…		…
1676		1972
1677	sub ready {	1973	sub ready {
1678	$_[0]{_ae_sent}	1974	$_[0]{_ae_sent}
1679	}	1975	}
1680		1976
1681	sub _wait {
1682	$WAITING
1683	and !$_[0]{_ae_sent}
1684	and Carp::croak "AnyEvent::CondVar: recursive blocking wait detected";
1685
1686	local $WAITING = 1;
1687	AnyEvent->one_event while !$_[0]{_ae_sent};
1688	}
1689
1690	sub recv {	1977	sub recv {
		1978	unless ($_[0]{_ae_sent}) {
		1979	$WAITING
		1980	and Carp::croak "AnyEvent::CondVar: recursive blocking wait attempted";
		1981
		1982	local $WAITING = 1;
1691	$_[0]->_wait;	1983	$_[0]->_wait;
		1984	}
1692		1985
1693	Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak};	1986	$_[0]{_ae_croak}
1694	wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0]	1987	and Carp::croak $_[0]{_ae_croak};
		1988
		1989	wantarray
		1990	? @{ $_[0]{_ae_sent} }
		1991	: $_[0]{_ae_sent}[0]
1695	}	1992	}
1696		1993
1697	sub cb {	1994	sub cb {
1698	my $cv = shift;	1995	my $cv = shift;
1699		1996
…		…
1715	&{ $_[0]{_ae_end_cb} || sub { $_[0]->send } };	2012	&{ $_[0]{_ae_end_cb} || sub { $_[0]->send } };
1716	}	2013	}
1717		2014
1718	# undocumented/compatibility with pre-3.4	2015	# undocumented/compatibility with pre-3.4
1719	*broadcast = \&send;	2016	*broadcast = \&send;
1720	*wait = \&_wait;	2017	*wait = \&recv;
1721		2018
1722	=head1 ERROR AND EXCEPTION HANDLING	2019	=head1 ERROR AND EXCEPTION HANDLING
1723		2020
1724	In general, AnyEvent does not do any error handling - it relies on the	2021	In general, AnyEvent does not do any error handling - it relies on the
1725	caller to do that if required. The L<AnyEvent::Strict> module (see also	2022	caller to do that if required. The L<AnyEvent::Strict> module (see also
…		…
1737	$Event/EV::DIED->() >>, L<Glib> uses C<< install_exception_handler >> and	2034	$Event/EV::DIED->() >>, L<Glib> uses C<< install_exception_handler >> and
1738	so on.	2035	so on.
1739		2036
1740	=head1 ENVIRONMENT VARIABLES	2037	=head1 ENVIRONMENT VARIABLES
1741		2038
1742	The following environment variables are used by this module or its	2039	AnyEvent supports a number of environment variables that tune the
1743	submodules.	2040	runtime behaviour. They are usually evaluated when AnyEvent is
		2041	loaded, initialised, or a submodule that uses them is loaded. Many of
		2042	them also cause AnyEvent to load additional modules - for example,
		2043	C<PERL_ANYEVENT_DEBUG_WRAP> causes the L<AnyEvent::Debug> module to be
		2044	loaded.
1744		2045
1745	Note that AnyEvent will remove I<all> environment variables starting with	2046	All the environment variables documented here start with
1746	C<PERL_ANYEVENT_> from C<%ENV> when it is loaded while taint mode is	2047	C<PERL_ANYEVENT_>, which is what AnyEvent considers its own
1747	enabled.	2048	namespace. Other modules are encouraged (but by no means required) to use
		2049	C<PERL_ANYEVENT_SUBMODULE> if they have registered the AnyEvent::Submodule
		2050	namespace on CPAN, for any submodule. For example, L<AnyEvent::HTTP> could
		2051	be expected to use C<PERL_ANYEVENT_HTTP_PROXY> (it should not access env
		2052	variables starting with C<AE_>, see below).
		2053
		2054	All variables can also be set via the C<AE_> prefix, that is, instead
		2055	of setting C<PERL_ANYEVENT_VERBOSE> you can also set C<AE_VERBOSE>. In
		2056	case there is a clash btween anyevent and another program that uses
		2057	C<AE_something> you can set the corresponding C<PERL_ANYEVENT_something>
		2058	variable to the empty string, as those variables take precedence.
		2059
		2060	When AnyEvent is first loaded, it copies all C<AE_xxx> env variables
		2061	to their C<PERL_ANYEVENT_xxx> counterpart unless that variable already
		2062	exists. If taint mode is on, then AnyEvent will remove I<all> environment
		2063	variables starting with C<PERL_ANYEVENT_> from C<%ENV> (or replace them
		2064	with C<undef> or the empty string, if the corresaponding C<AE_> variable
		2065	is set).
		2066
		2067	The exact algorithm is currently:
		2068
		2069	1. if taint mode enabled, delete all PERL_ANYEVENT_xyz variables from %ENV
		2070	2. copy over AE_xyz to PERL_ANYEVENT_xyz unless the latter alraedy exists
		2071	3. if taint mode enabled, set all PERL_ANYEVENT_xyz variables to undef.
		2072
		2073	This ensures that child processes will not see the C<AE_> variables.
		2074
		2075	The following environment variables are currently known to AnyEvent:
1748		2076
1749	=over 4	2077	=over 4
1750		2078
1751	=item C<PERL_ANYEVENT_VERBOSE>	2079	=item C<PERL_ANYEVENT_VERBOSE>
1752		2080
1753	By default, AnyEvent will be completely silent except in fatal	2081	By default, AnyEvent will only log messages with loglevel C<3>
1754	conditions. You can set this environment variable to make AnyEvent more	2082	(C<critical>) or higher (see L<AnyEvent::Log>). You can set this
		2083	environment variable to a numerical loglevel to make AnyEvent more (or
1755	talkative.	2084	less) talkative.
1756		2085
		2086	If you want to do more than just set the global logging level
		2087	you should have a look at C<PERL_ANYEVENT_LOG>, which allows much more
		2088	complex specifications.
		2089
		2090	When set to C<0> (C<off>), then no messages whatsoever will be logged with
		2091	the default logging settings.
		2092
1757	When set to C<1> or higher, causes AnyEvent to warn about unexpected	2093	When set to C<5> or higher (C<warn>), causes AnyEvent to warn about
1758	conditions, such as not being able to load the event model specified by	2094	unexpected conditions, such as not being able to load the event model
1759	C<PERL_ANYEVENT_MODEL>.	2095	specified by C<PERL_ANYEVENT_MODEL>, or a guard callback throwing an
		2096	exception - this is the minimum recommended level.
1760		2097
1761	When set to C<2> or higher, cause AnyEvent to report to STDERR which event	2098	When set to C<7> or higher (info), cause AnyEvent to report which event model it
1762	model it chooses.	2099	chooses.
1763		2100
1764	When set to C<8> or higher, then AnyEvent will report extra information on	2101	When set to C<8> or higher (debug), then AnyEvent will report extra information on
1765	which optional modules it loads and how it implements certain features.	2102	which optional modules it loads and how it implements certain features.
		2103
		2104	=item C<PERL_ANYEVENT_LOG>
		2105
		2106	Accepts rather complex logging specifications. For example, you could log
		2107	all C<debug> messages of some module to stderr, warnings and above to
		2108	stderr, and errors and above to syslog, with:
		2109
		2110	PERL_ANYEVENT_LOG=Some::Module=debug,+log:filter=warn,+%syslog:%syslog=error,syslog
		2111
		2112	For the rather extensive details, see L<AnyEvent::Log>.
		2113
		2114	This variable is evaluated when AnyEvent (or L<AnyEvent::Log>) is loaded,
		2115	so will take effect even before AnyEvent has initialised itself.
		2116
		2117	Note that specifying this environment variable causes the L<AnyEvent::Log>
		2118	module to be loaded, while C<PERL_ANYEVENT_VERBOSE> does not, so only
		2119	using the latter saves a few hundred kB of memory until the first message
		2120	is being logged.
1766		2121
1767	=item C<PERL_ANYEVENT_STRICT>	2122	=item C<PERL_ANYEVENT_STRICT>
1768		2123
1769	AnyEvent does not do much argument checking by default, as thorough	2124	AnyEvent does not do much argument checking by default, as thorough
1770	argument checking is very costly. Setting this variable to a true value	2125	argument checking is very costly. Setting this variable to a true value
…		…
1772	check the arguments passed to most method calls. If it finds any problems,	2127	check the arguments passed to most method calls. If it finds any problems,
1773	it will croak.	2128	it will croak.
1774		2129
1775	In other words, enables "strict" mode.	2130	In other words, enables "strict" mode.
1776		2131
1777	Unlike C<use strict> (or it's modern cousin, C<< use L<common::sense>	2132	Unlike C<use strict> (or its modern cousin, C<< use L<common::sense>
1778	>>, it is definitely recommended to keep it off in production. Keeping	2133	>>, it is definitely recommended to keep it off in production. Keeping
1779	C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs	2134	C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs
1780	can be very useful, however.	2135	can be very useful, however.
1781		2136
		2137	=item C<PERL_ANYEVENT_DEBUG_SHELL>
		2138
		2139	If this env variable is nonempty, then its contents will be interpreted by
		2140	C<AnyEvent::Socket::parse_hostport> and C<AnyEvent::Debug::shell> (after
		2141	replacing every occurance of C<$$> by the process pid). The shell object
		2142	is saved in C<$AnyEvent::Debug::SHELL>.
		2143
		2144	This happens when the first watcher is created.
		2145
		2146	For example, to bind a debug shell on a unix domain socket in
		2147	F<< /tmp/debug<pid>.sock >>, you could use this:
		2148
		2149	PERL_ANYEVENT_DEBUG_SHELL=/tmp/debug\$\$.sock perlprog
		2150	# connect with e.g.: socat readline /tmp/debug123.sock
		2151
		2152	Or to bind to tcp port 4545 on localhost:
		2153
		2154	PERL_ANYEVENT_DEBUG_SHELL=127.0.0.1:4545 perlprog
		2155	# connect with e.g.: telnet localhost 4545
		2156
		2157	Note that creating sockets in F</tmp> or on localhost is very unsafe on
		2158	multiuser systems.
		2159
		2160	=item C<PERL_ANYEVENT_DEBUG_WRAP>
		2161
		2162	Can be set to C<0>, C<1> or C<2> and enables wrapping of all watchers for
		2163	debugging purposes. See C<AnyEvent::Debug::wrap> for details.
		2164
1782	=item C<PERL_ANYEVENT_MODEL>	2165	=item C<PERL_ANYEVENT_MODEL>
1783		2166
1784	This can be used to specify the event model to be used by AnyEvent, before	2167	This can be used to specify the event model to be used by AnyEvent, before
1785	auto detection and -probing kicks in. It must be a string consisting	2168	auto detection and -probing kicks in.
1786	entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended	2169
		2170	It normally is a string consisting entirely of ASCII letters (e.g. C<EV>
		2171	or C<IOAsync>). The string C<AnyEvent::Impl::> gets prepended and the
1787	and the resulting module name is loaded and if the load was successful,	2172	resulting module name is loaded and - if the load was successful - used as
1788	used as event model. If it fails to load AnyEvent will proceed with	2173	event model backend. If it fails to load then AnyEvent will proceed with
1789	auto detection and -probing.	2174	auto detection and -probing.
1790		2175
1791	This functionality might change in future versions.	2176	If the string ends with C<::> instead (e.g. C<AnyEvent::Impl::EV::>) then
		2177	nothing gets prepended and the module name is used as-is (hint: C<::> at
		2178	the end of a string designates a module name and quotes it appropriately).
1792		2179
1793	For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you	2180	For example, to force the pure perl model (L<AnyEvent::Loop::Perl>) you
1794	could start your program like this:	2181	could start your program like this:
1795		2182
1796	PERL_ANYEVENT_MODEL=Perl perl ...	2183	PERL_ANYEVENT_MODEL=Perl perl ...
1797		2184
1798	=item C<PERL_ANYEVENT_PROTOCOLS>	2185	=item C<PERL_ANYEVENT_PROTOCOLS>
…		…
1814	but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4>	2201	but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4>
1815	- only support IPv4, never try to resolve or contact IPv6	2202	- only support IPv4, never try to resolve or contact IPv6
1816	addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or	2203	addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or
1817	IPv6, but prefer IPv6 over IPv4.	2204	IPv6, but prefer IPv6 over IPv4.
1818		2205
		2206	=item C<PERL_ANYEVENT_HOSTS>
		2207
		2208	This variable, if specified, overrides the F</etc/hosts> file used by
		2209	L<AnyEvent::Socket>C<::resolve_sockaddr>, i.e. hosts aliases will be read
		2210	from that file instead.
		2211
1819	=item C<PERL_ANYEVENT_EDNS0>	2212	=item C<PERL_ANYEVENT_EDNS0>
1820		2213
1821	Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension	2214	Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension for
1822	for DNS. This extension is generally useful to reduce DNS traffic, but	2215	DNS. This extension is generally useful to reduce DNS traffic, especially
1823	some (broken) firewalls drop such DNS packets, which is why it is off by	2216	when DNSSEC is involved, but some (broken) firewalls drop such DNS
1824	default.	2217	packets, which is why it is off by default.
1825		2218
1826	Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce	2219	Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce
1827	EDNS0 in its DNS requests.	2220	EDNS0 in its DNS requests.
1828		2221
1829	=item C<PERL_ANYEVENT_MAX_FORKS>	2222	=item C<PERL_ANYEVENT_MAX_FORKS>
…		…
1835		2228
1836	The default value for the C<max_outstanding> parameter for the default DNS	2229	The default value for the C<max_outstanding> parameter for the default DNS
1837	resolver - this is the maximum number of parallel DNS requests that are	2230	resolver - this is the maximum number of parallel DNS requests that are
1838	sent to the DNS server.	2231	sent to the DNS server.
1839		2232
		2233	=item C<PERL_ANYEVENT_MAX_SIGNAL_LATENCY>
		2234
		2235	Perl has inherently racy signal handling (you can basically choose between
		2236	losing signals and memory corruption) - pure perl event loops (including
		2237	C<AnyEvent::Loop>, when C<Async::Interrupt> isn't available) therefore
		2238	have to poll regularly to avoid losing signals.
		2239
		2240	Some event loops are racy, but don't poll regularly, and some event loops
		2241	are written in C but are still racy. For those event loops, AnyEvent
		2242	installs a timer that regularly wakes up the event loop.
		2243
		2244	By default, the interval for this timer is C<10> seconds, but you can
		2245	override this delay with this environment variable (or by setting
		2246	the C<$AnyEvent::MAX_SIGNAL_LATENCY> variable before creating signal
		2247	watchers).
		2248
		2249	Lower values increase CPU (and energy) usage, higher values can introduce
		2250	long delays when reaping children or waiting for signals.
		2251
		2252	The L<AnyEvent::Async> module, if available, will be used to avoid this
		2253	polling (with most event loops).
		2254
1840	=item C<PERL_ANYEVENT_RESOLV_CONF>	2255	=item C<PERL_ANYEVENT_RESOLV_CONF>
1841		2256
1842	The file to use instead of F</etc/resolv.conf> (or OS-specific	2257	The absolute path to a F<resolv.conf>-style file to use instead of
1843	configuration) in the default resolver. When set to the empty string, no	2258	F</etc/resolv.conf> (or the OS-specific configuration) in the default
1844	default config will be used.	2259	resolver, or the empty string to select the default configuration.
1845		2260
1846	=item C<PERL_ANYEVENT_CA_FILE>, C<PERL_ANYEVENT_CA_PATH>.	2261	=item C<PERL_ANYEVENT_CA_FILE>, C<PERL_ANYEVENT_CA_PATH>.
1847		2262
1848	When neither C<ca_file> nor C<ca_path> was specified during	2263	When neither C<ca_file> nor C<ca_path> was specified during
1849	L<AnyEvent::TLS> context creation, and either of these environment	2264	L<AnyEvent::TLS> context creation, and either of these environment
1850	variables exist, they will be used to specify CA certificate locations	2265	variables are nonempty, they will be used to specify CA certificate
1851	instead of a system-dependent default.	2266	locations instead of a system-dependent default.
1852		2267
1853	=item C<PERL_ANYEVENT_AVOID_GUARD> and C<PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT>	2268	=item C<PERL_ANYEVENT_AVOID_GUARD> and C<PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT>
1854		2269
1855	When these are set to C<1>, then the respective modules are not	2270	When these are set to C<1>, then the respective modules are not
1856	loaded. Mostly good for testing AnyEvent itself.	2271	loaded. Mostly good for testing AnyEvent itself.
…		…
2004		2419
2005	The actual code goes further and collects all errors (C<die>s, exceptions)	2420	The actual code goes further and collects all errors (C<die>s, exceptions)
2006	that occurred during request processing. The C<result> method detects	2421	that occurred during request processing. The C<result> method detects
2007	whether an exception as thrown (it is stored inside the $txn object)	2422	whether an exception as thrown (it is stored inside the $txn object)
2008	and just throws the exception, which means connection errors and other	2423	and just throws the exception, which means connection errors and other
2009	problems get reported tot he code that tries to use the result, not in a	2424	problems get reported to the code that tries to use the result, not in a
2010	random callback.	2425	random callback.
2011		2426
2012	All of this enables the following usage styles:	2427	All of this enables the following usage styles:
2013		2428
2014	1. Blocking:	2429	1. Blocking:
…		…
2188	(even when used without AnyEvent), but most event loops have acceptable	2603	(even when used without AnyEvent), but most event loops have acceptable
2189	performance with or without AnyEvent.	2604	performance with or without AnyEvent.
2190		2605
2191	=item * The overhead AnyEvent adds is usually much smaller than the overhead of	2606	=item * The overhead AnyEvent adds is usually much smaller than the overhead of
2192	the actual event loop, only with extremely fast event loops such as EV	2607	the actual event loop, only with extremely fast event loops such as EV
2193	adds AnyEvent significant overhead.	2608	does AnyEvent add significant overhead.
2194		2609
2195	=item * You should avoid POE like the plague if you want performance or	2610	=item * You should avoid POE like the plague if you want performance or
2196	reasonable memory usage.	2611	reasonable memory usage.
2197		2612
2198	=back	2613	=back
…		…
2428	unless defined $SIG{PIPE};	2843	unless defined $SIG{PIPE};
2429		2844
2430	=head1 RECOMMENDED/OPTIONAL MODULES	2845	=head1 RECOMMENDED/OPTIONAL MODULES
2431		2846
2432	One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and	2847	One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and
2433	it's built-in modules) are required to use it.	2848	its built-in modules) are required to use it.
2434		2849
2435	That does not mean that AnyEvent won't take advantage of some additional	2850	That does not mean that AnyEvent won't take advantage of some additional
2436	modules if they are installed.	2851	modules if they are installed.
2437		2852
2438	This section epxlains which additional modules will be used, and how they	2853	This section explains which additional modules will be used, and how they
2439	affect AnyEvent's operetion.	2854	affect AnyEvent's operation.
2440		2855
2441	=over 4	2856	=over 4
2442		2857
2443	=item L<Async::Interrupt>	2858	=item L<Async::Interrupt>
2444		2859
…		…
2449	catch the signals) with some delay (default is 10 seconds, look for	2864	catch the signals) with some delay (default is 10 seconds, look for
2450	C<$AnyEvent::MAX_SIGNAL_LATENCY>).	2865	C<$AnyEvent::MAX_SIGNAL_LATENCY>).
2451		2866
2452	If this module is available, then it will be used to implement signal	2867	If this module is available, then it will be used to implement signal
2453	catching, which means that signals will not be delayed, and the event loop	2868	catching, which means that signals will not be delayed, and the event loop
2454	will not be interrupted regularly, which is more efficient (And good for	2869	will not be interrupted regularly, which is more efficient (and good for
2455	battery life on laptops).	2870	battery life on laptops).
2456		2871
2457	This affects not just the pure-perl event loop, but also other event loops	2872	This affects not just the pure-perl event loop, but also other event loops
2458	that have no signal handling on their own (e.g. Glib, Tk, Qt).	2873	that have no signal handling on their own (e.g. Glib, Tk, Qt).
2459		2874
…		…
2471	automatic timer adjustments even when no monotonic clock is available,	2886	automatic timer adjustments even when no monotonic clock is available,
2472	can take avdantage of advanced kernel interfaces such as C<epoll> and	2887	can take avdantage of advanced kernel interfaces such as C<epoll> and
2473	C<kqueue>, and is the fastest backend I<by far>. You can even embed	2888	C<kqueue>, and is the fastest backend I<by far>. You can even embed
2474	L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>).	2889	L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>).
2475		2890
		2891	If you only use backends that rely on another event loop (e.g. C<Tk>),
		2892	then this module will do nothing for you.
		2893
2476	=item L<Guard>	2894	=item L<Guard>
2477		2895
2478	The guard module, when used, will be used to implement	2896	The guard module, when used, will be used to implement
2479	C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a	2897	C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a
2480	lot less memory), but otherwise doesn't affect guard operation much. It is	2898	lot less memory), but otherwise doesn't affect guard operation much. It is
2481	purely used for performance.	2899	purely used for performance.
2482		2900
2483	=item L<JSON> and L<JSON::XS>	2901	=item L<JSON> and L<JSON::XS>
2484		2902
2485	One of these modules is required when you want to read or write JSON data	2903	One of these modules is required when you want to read or write JSON data
2486	via L<AnyEvent::Handle>. It is also written in pure-perl, but can take	2904	via L<AnyEvent::Handle>. L<JSON> is also written in pure-perl, but can take
2487	advantage of the ultra-high-speed L<JSON::XS> module when it is installed.	2905	advantage of the ultra-high-speed L<JSON::XS> module when it is installed.
2488
2489	In fact, L<AnyEvent::Handle> will use L<JSON::XS> by default if it is
2490	installed.
2491		2906
2492	=item L<Net::SSLeay>	2907	=item L<Net::SSLeay>
2493		2908
2494	Implementing TLS/SSL in Perl is certainly interesting, but not very	2909	Implementing TLS/SSL in Perl is certainly interesting, but not very
2495	worthwhile: If this module is installed, then L<AnyEvent::Handle> (with	2910	worthwhile: If this module is installed, then L<AnyEvent::Handle> (with
2496	the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL.	2911	the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL.
2497		2912
2498	=item L<Time::HiRes>	2913	=item L<Time::HiRes>
2499		2914
2500	This module is part of perl since release 5.008. It will be used when the	2915	This module is part of perl since release 5.008. It will be used when the
2501	chosen event library does not come with a timing source on it's own. The	2916	chosen event library does not come with a timing source of its own. The
2502	pure-perl event loop (L<AnyEvent::Impl::Perl>) will additionally use it to	2917	pure-perl event loop (L<AnyEvent::Loop>) will additionally load it to
2503	try to use a monotonic clock for timing stability.	2918	try to use a monotonic clock for timing stability.
2504		2919
2505	=back	2920	=back
2506		2921
2507		2922
2508	=head1 FORK	2923	=head1 FORK
2509		2924
2510	Most event libraries are not fork-safe. The ones who are usually are	2925	Most event libraries are not fork-safe. The ones who are usually are
2511	because they rely on inefficient but fork-safe C<select> or C<poll>	2926	because they rely on inefficient but fork-safe C<select> or C<poll> calls
2512	calls. Only L<EV> is fully fork-aware.	2927	- higher performance APIs such as BSD's kqueue or the dreaded Linux epoll
		2928	are usually badly thought-out hacks that are incompatible with fork in
		2929	one way or another. Only L<EV> is fully fork-aware and ensures that you
		2930	continue event-processing in both parent and child (or both, if you know
		2931	what you are doing).
		2932
		2933	This means that, in general, you cannot fork and do event processing in
		2934	the child if the event library was initialised before the fork (which
		2935	usually happens when the first AnyEvent watcher is created, or the library
		2936	is loaded).
2513		2937
2514	If you have to fork, you must either do so I<before> creating your first	2938	If you have to fork, you must either do so I<before> creating your first
2515	watcher OR you must not use AnyEvent at all in the child OR you must do	2939	watcher OR you must not use AnyEvent at all in the child OR you must do
2516	something completely out of the scope of AnyEvent.	2940	something completely out of the scope of AnyEvent.
		2941
		2942	The problem of doing event processing in the parent I<and> the child
		2943	is much more complicated: even for backends that I<are> fork-aware or
		2944	fork-safe, their behaviour is not usually what you want: fork clones all
		2945	watchers, that means all timers, I/O watchers etc. are active in both
		2946	parent and child, which is almost never what you want. USing C<exec>
		2947	to start worker children from some kind of manage rprocess is usually
		2948	preferred, because it is much easier and cleaner, at the expense of having
		2949	to have another binary.
2517		2950
2518		2951
2519	=head1 SECURITY CONSIDERATIONS	2952	=head1 SECURITY CONSIDERATIONS
2520		2953
2521	AnyEvent can be forced to load any event model via	2954	AnyEvent can be forced to load any event model via
…		…
2551	pronounced).	2984	pronounced).
2552		2985
2553		2986
2554	=head1 SEE ALSO	2987	=head1 SEE ALSO
2555		2988
2556	Utility functions: L<AnyEvent::Util>.	2989	Tutorial/Introduction: L<AnyEvent::Intro>.
2557		2990
2558	Event modules: L<EV>, L<EV::Glib>, L<Glib::EV>, L<Event>, L<Glib::Event>,	2991	FAQ: L<AnyEvent::FAQ>.
2559	L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.	2992
		2993	Utility functions: L<AnyEvent::Util> (misc. grab-bag), L<AnyEvent::Log>
		2994	(simply logging).
		2995
		2996	Development/Debugging: L<AnyEvent::Strict> (stricter checking),
		2997	L<AnyEvent::Debug> (interactive shell, watcher tracing).
		2998
		2999	Supported event modules: L<AnyEvent::Loop>, L<EV>, L<EV::Glib>,
		3000	L<Glib::EV>, L<Event>, L<Glib::Event>, L<Glib>, L<Tk>, L<Event::Lib>,
		3001	L<Qt>, L<POE>, L<FLTK>.
2560		3002
2561	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,	3003	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,
2562	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,	3004	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,
2563	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,	3005	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,
2564	L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>, L<Anyevent::Impl::Irssi>.	3006	L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>, L<Anyevent::Impl::Irssi>,
		3007	L<AnyEvent::Impl::FLTK>.
2565		3008
2566	Non-blocking file handles, sockets, TCP clients and	3009	Non-blocking handles, pipes, stream sockets, TCP clients and
2567	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.	3010	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.
2568		3011
2569	Asynchronous DNS: L<AnyEvent::DNS>.	3012	Asynchronous DNS: L<AnyEvent::DNS>.
2570		3013
2571	Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>,	3014	Thread support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>.
2572	L<Coro::Event>,
2573		3015
2574	Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::XMPP>,	3016	Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::IRC>,
2575	L<AnyEvent::HTTP>.	3017	L<AnyEvent::HTTP>.
2576		3018
2577		3019
2578	=head1 AUTHOR	3020	=head1 AUTHOR
2579		3021

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