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Revision 1.388 by root, Sun Oct 2 01:22:01 2011 UTC

1	=head1 NAME	1	=head1 NAME
2		2
3	AnyEvent - provide framework for multiple event loops	3	AnyEvent - the DBI of event loop programming
4		4
5	EV, Event, Glib, Tk, Perl, Event::Lib, Qt, POE - various supported event loops	5	EV, Event, Glib, Tk, Perl, Event::Lib, Irssi, rxvt-unicode, IO::Async, Qt,
		6	FLTK and POE are various supported event loops/environments.
6		7
7	=head1 SYNOPSIS	8	=head1 SYNOPSIS
8		9
9	use AnyEvent;	10	use AnyEvent;
10		11
		12	# if you prefer function calls, look at the AE manpage for
		13	# an alternative API.
		14
		15	# file handle or descriptor readable
11	my $w = AnyEvent->io (fh => $fh, poll => "r|w", cb => sub { ... });	16	my $w = AnyEvent->io (fh => $fh, poll => "r", cb => sub { ... });
12		17
		18	# one-shot or repeating timers
13	my $w = AnyEvent->timer (after => $seconds, cb => sub { ... });	19	my $w = AnyEvent->timer (after => $seconds, cb => sub { ... });
14	my $w = AnyEvent->timer (after => $seconds, interval => $seconds, cb => ...	20	my $w = AnyEvent->timer (after => $seconds, interval => $seconds, cb => ...);
15		21
16	print AnyEvent->now; # prints current event loop time	22	print AnyEvent->now; # prints current event loop time
17	print AnyEvent->time; # think Time::HiRes::time or simply CORE::time.	23	print AnyEvent->time; # think Time::HiRes::time or simply CORE::time.
18		24
		25	# POSIX signal
19	my $w = AnyEvent->signal (signal => "TERM", cb => sub { ... });	26	my $w = AnyEvent->signal (signal => "TERM", cb => sub { ... });
20		27
		28	# child process exit
21	my $w = AnyEvent->child (pid => $pid, cb => sub {	29	my $w = AnyEvent->child (pid => $pid, cb => sub {
22	my ($pid, $status) = @_;	30	my ($pid, $status) = @_;
23	...	31	...
24	});	32	});
		33
		34	# called when event loop idle (if applicable)
		35	my $w = AnyEvent->idle (cb => sub { ... });
25		36
26	my $w = AnyEvent->condvar; # stores whether a condition was flagged	37	my $w = AnyEvent->condvar; # stores whether a condition was flagged
27	$w->send; # wake up current and all future recv's	38	$w->send; # wake up current and all future recv's
28	$w->recv; # enters "main loop" till $condvar gets ->send	39	$w->recv; # enters "main loop" till $condvar gets ->send
29	# use a condvar in callback mode:	40	# use a condvar in callback mode:
…		…
32	=head1 INTRODUCTION/TUTORIAL	43	=head1 INTRODUCTION/TUTORIAL
33		44
34	This manpage is mainly a reference manual. If you are interested	45	This manpage is mainly a reference manual. If you are interested
35	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
36	L<AnyEvent::Intro> manpage.	47	L<AnyEvent::Intro> manpage.
		48
		49	=head1 SUPPORT
		50
		51	An FAQ document is available as L<AnyEvent::FAQ>.
		52
		53	There also is a mailinglist for discussing all things AnyEvent, and an IRC
		54	channel, too.
		55
		56	See the AnyEvent project page at the B<Schmorpforge Ta-Sa Software
		57	Repository>, at L<http://anyevent.schmorp.de>, for more info.
37		58
38	=head1 WHY YOU SHOULD USE THIS MODULE (OR NOT)	59	=head1 WHY YOU SHOULD USE THIS MODULE (OR NOT)
39		60
40	Glib, POE, IO::Async, Event... CPAN offers event models by the dozen	61	Glib, POE, IO::Async, Event... CPAN offers event models by the dozen
41	nowadays. So what is different about AnyEvent?	62	nowadays. So what is different about AnyEvent?
…		…
57	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
58	model you use.	79	model you use.
59		80
60	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
61	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
62	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
63	cannot use anything else, as they are simply incompatible to everything	84	cannot use anything else, as they are simply incompatible to everything
64	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
65	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.
66		87
67	AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works	88	AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works
68	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
69	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
70	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
71	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
72	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
73	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,
74	to AnyEvent, too, so it is future-proof).	95	so it is future-proof).
75		96
76	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
77	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
78	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
79	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
80	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
81	technically possible.	102	technically possible.
82		103
83	Of course, AnyEvent comes with a big (and fully optional!) toolbox	104	Of course, AnyEvent comes with a big (and fully optional!) toolbox
84	of useful functionality, such as an asynchronous DNS resolver, 100%	105	of useful functionality, such as an asynchronous DNS resolver, 100%
…		…
90	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
91	model, you should I<not> use this module.	112	model, you should I<not> use this module.
92		113
93	=head1 DESCRIPTION	114	=head1 DESCRIPTION
94		115
95	L<AnyEvent> provides an identical interface to multiple event loops. This	116	L<AnyEvent> provides a uniform interface to various event loops. This
96	allows module authors to utilise an event loop without forcing module	117	allows module authors to use event loop functionality without forcing
97	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
98	peacefully at any one time).	119	than one event loop cannot coexist peacefully).
99		120
100	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>
101	module.	122	module.
102		123
103	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
104	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
105	following modules is already loaded: L<EV>,	126	following modules is already loaded: L<EV>, L<AnyEvent::Loop>,
106	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
107	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
108	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
109	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
110	be successfully loaded will be used. If, after this, still none could be	131	the other two are not normally tried.
111	found, AnyEvent will fall back to a pure-perl event loop, which is not
112	very efficient, but should work everywhere.
113		132
114	Because AnyEvent first checks for modules that are already loaded, loading	133	Because AnyEvent first checks for modules that are already loaded, loading
115	an event model explicitly before first using AnyEvent will likely make	134	an event model explicitly before first using AnyEvent will likely make
116	that model the default. For example:	135	that model the default. For example:
117		136
…		…
119	use AnyEvent;	138	use AnyEvent;
120		139
121	# .. AnyEvent will likely default to Tk	140	# .. AnyEvent will likely default to Tk
122		141
123	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
124	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,
125	use AnyEvent so their modules work together with others seamlessly...	144	as very few modules hardcode event loops without announcing this very
		145	loudly.
126		146
127	The pure-perl implementation of AnyEvent is called	147	The pure-perl implementation of AnyEvent is called C<AnyEvent::Loop>. Like
128	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
129	explicitly and enjoy the high availability of that event loop :)	149	availability of that event loop :)
130		150
131	=head1 WATCHERS	151	=head1 WATCHERS
132		152
133	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
134	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
…		…
139	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
140	is in control).	160	is in control).
141		161
142	Note that B<callbacks must not permanently change global variables>	162	Note that B<callbacks must not permanently change global variables>
143	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<<
144	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
145	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
146	widely between event loops.	166	widely between event loops.
147		167
148	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
149	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
150	to it).	170	to it).
151		171
152	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.
153		173
154	Many watchers either are used with "recursion" (repeating timers for	174	Many watchers either are used with "recursion" (repeating timers for
155	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.
156		176
157	An any way to achieve that is this pattern:	177	One way to achieve that is this pattern:
158		178
159	my $w; $w = AnyEvent->type (arg => value ..., cb => sub {	179	my $w; $w = AnyEvent->type (arg => value ..., cb => sub {
160	# you can use $w here, for example to undef it	180	# you can use $w here, for example to undef it
161	undef $w;	181	undef $w;
162	});	182	});
…		…
165	my variables are only visible after the statement in which they are	185	my variables are only visible after the statement in which they are
166	declared.	186	declared.
167		187
168	=head2 I/O WATCHERS	188	=head2 I/O WATCHERS
169		189
		190	$w = AnyEvent->io (
		191	fh => <filehandle_or_fileno>,
		192	poll => <"r" or "w">,
		193	cb => <callback>,
		194	);
		195
170	You can create an I/O watcher by calling the C<< AnyEvent->io >> method	196	You can create an I/O watcher by calling the C<< AnyEvent->io >> method
171	with the following mandatory key-value pairs as arguments:	197	with the following mandatory key-value pairs as arguments:
172		198
173	C<fh> the Perl I<file handle> (I<not> file descriptor) to watch for events	199	C<fh> is the Perl I<file handle> (or a naked file descriptor) to watch
174	(AnyEvent might or might not keep a reference to this file handle). C<poll>	200	for events (AnyEvent might or might not keep a reference to this file
		201	handle). Note that only file handles pointing to things for which
		202	non-blocking operation makes sense are allowed. This includes sockets,
		203	most character devices, pipes, fifos and so on, but not for example files
		204	or block devices.
		205
175	must be a string that is either C<r> or C<w>, which creates a watcher	206	C<poll> must be a string that is either C<r> or C<w>, which creates a
176	waiting for "r"eadable or "w"ritable events, respectively. C<cb> is the	207	watcher waiting for "r"eadable or "w"ritable events, respectively.
		208
177	callback to invoke each time the file handle becomes ready.	209	C<cb> is the callback to invoke each time the file handle becomes ready.
178		210
179	Although the callback might get passed parameters, their value and	211	Although the callback might get passed parameters, their value and
180	presence is undefined and you cannot rely on them. Portable AnyEvent	212	presence is undefined and you cannot rely on them. Portable AnyEvent
181	callbacks cannot use arguments passed to I/O watcher callbacks.	213	callbacks cannot use arguments passed to I/O watcher callbacks.
182		214
183	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.
184	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
185	underlying file descriptor.	217	underlying file descriptor.
186		218
187	Some event loops issue spurious readyness notifications, so you should	219	Some event loops issue spurious readiness notifications, so you should
188	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
189	handles.	221	handles.
190		222
191	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
192	watcher.	224	watcher.
…		…
197	undef $w;	229	undef $w;
198	});	230	});
199		231
200	=head2 TIME WATCHERS	232	=head2 TIME WATCHERS
201		233
		234	$w = AnyEvent->timer (after => <seconds>, cb => <callback>);
		235
		236	$w = AnyEvent->timer (
		237	after => <fractional_seconds>,
		238	interval => <fractional_seconds>,
		239	cb => <callback>,
		240	);
		241
202	You can create a time watcher by calling the C<< AnyEvent->timer >>	242	You can create a time watcher by calling the C<< AnyEvent->timer >>
203	method with the following mandatory arguments:	243	method with the following mandatory arguments:
204		244
205	C<after> specifies after how many seconds (fractional values are	245	C<after> specifies after how many seconds (fractional values are
206	supported) the callback should be invoked. C<cb> is the callback to invoke	246	supported) the callback should be invoked. C<cb> is the callback to invoke
…		…
208		248
209	Although the callback might get passed parameters, their value and	249	Although the callback might get passed parameters, their value and
210	presence is undefined and you cannot rely on them. Portable AnyEvent	250	presence is undefined and you cannot rely on them. Portable AnyEvent
211	callbacks cannot use arguments passed to time watcher callbacks.	251	callbacks cannot use arguments passed to time watcher callbacks.
212		252
213	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
214	parameter, C<interval>, as a strictly positive number (> 0), then the	254	parameter, C<interval>, as a strictly positive number (> 0), then the
215	callback will be invoked regularly at that interval (in fractional	255	callback will be invoked regularly at that interval (in fractional
216	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
217	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.
218		258
219	The callback will be rescheduled before invoking the callback, but no	259	The callback will be rescheduled before invoking the callback, but no
220	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
221	only approximate.	261	only approximate.
222		262
223	Example: fire an event after 7.7 seconds.	263	Example: fire an event after 7.7 seconds.
224		264
225	my $w = AnyEvent->timer (after => 7.7, cb => sub {	265	my $w = AnyEvent->timer (after => 7.7, cb => sub {
…		…
243		283
244	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
245	use absolute time internally. This makes a difference when your clock	285	use absolute time internally. This makes a difference when your clock
246	"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
247	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
248	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.
249		289
250	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
251	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
252	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)
253	timers.	293	timers.
254		294
255	AnyEvent always prefers relative timers, if available, matching the	295	AnyEvent always prefers relative timers, if available, matching the
256	AnyEvent API.	296	AnyEvent API.
…		…
278	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
279	function to call when you want to know the current time.>	319	function to call when you want to know the current time.>
280		320
281	This function is also often faster then C<< AnyEvent->time >>, and	321	This function is also often faster then C<< AnyEvent->time >>, and
282	thus the preferred method if you want some timestamp (for example,	322	thus the preferred method if you want some timestamp (for example,
283	L<AnyEvent::Handle> uses this to update it's activity timeouts).	323	L<AnyEvent::Handle> uses this to update its activity timeouts).
284		324
285	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
286	with your timing, you can skip it without bad conscience.	326	with your timing; you can skip it without a bad conscience.
287		327
288	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>
289	and L<EV> and the following set-up:	329	and L<EV> and the following set-up:
290		330
291	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
292	time=500 (assume no other callbacks delay processing). In your callback,	332	time=500 (assume no other callbacks delay processing). In your callback,
293	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
294	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
295	after three seconds.	335	after three seconds.
296		336
…		…
314	In either case, if you care (and in most cases, you don't), then you	354	In either case, if you care (and in most cases, you don't), then you
315	can get whatever behaviour you want with any event loop, by taking the	355	can get whatever behaviour you want with any event loop, by taking the
316	difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into	356	difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into
317	account.	357	account.
318		358
		359	=item AnyEvent->now_update
		360
		361	Some event loops (such as L<EV> or L<AnyEvent::Loop>) cache the current
		362	time for each loop iteration (see the discussion of L<< AnyEvent->now >>,
		363	above).
		364
		365	When a callback runs for a long time (or when the process sleeps), then
		366	this "current" time will differ substantially from the real time, which
		367	might affect timers and time-outs.
		368
		369	When this is the case, you can call this method, which will update the
		370	event loop's idea of "current time".
		371
		372	A typical example would be a script in a web server (e.g. C<mod_perl>) -
		373	when mod_perl executes the script, then the event loop will have the wrong
		374	idea about the "current time" (being potentially far in the past, when the
		375	script ran the last time). In that case you should arrange a call to C<<
		376	AnyEvent->now_update >> each time the web server process wakes up again
		377	(e.g. at the start of your script, or in a handler).
		378
		379	Note that updating the time I<might> cause some events to be handled.
		380
319	=back	381	=back
320		382
321	=head2 SIGNAL WATCHERS	383	=head2 SIGNAL WATCHERS
		384
		385	$w = AnyEvent->signal (signal => <uppercase_signal_name>, cb => <callback>);
322		386
323	You can watch for signals using a signal watcher, C<signal> is the signal	387	You can watch for signals using a signal watcher, C<signal> is the signal
324	I<name> in uppercase and without any C<SIG> prefix, C<cb> is the Perl	388	I<name> in uppercase and without any C<SIG> prefix, C<cb> is the Perl
325	callback to be invoked whenever a signal occurs.	389	callback to be invoked whenever a signal occurs.
326		390
…		…
332	invocation, and callback invocation will be synchronous. Synchronous means	396	invocation, and callback invocation will be synchronous. Synchronous means
333	that it might take a while until the signal gets handled by the process,	397	that it might take a while until the signal gets handled by the process,
334	but it is guaranteed not to interrupt any other callbacks.	398	but it is guaranteed not to interrupt any other callbacks.
335		399
336	The main advantage of using these watchers is that you can share a signal	400	The main advantage of using these watchers is that you can share a signal
337	between multiple watchers.	401	between multiple watchers, and AnyEvent will ensure that signals will not
		402	interrupt your program at bad times.
338		403
339	This watcher might use C<%SIG>, so programs overwriting those signals	404	This watcher might use C<%SIG> (depending on the event loop used),
340	directly will likely not work correctly.	405	so programs overwriting those signals directly will likely not work
		406	correctly.
341		407
342	Example: exit on SIGINT	408	Example: exit on SIGINT
343		409
344	my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });	410	my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });
345		411
		412	=head3 Restart Behaviour
		413
		414	While restart behaviour is up to the event loop implementation, most will
		415	not restart syscalls (that includes L<Async::Interrupt> and AnyEvent's
		416	pure perl implementation).
		417
		418	=head3 Safe/Unsafe Signals
		419
		420	Perl signals can be either "safe" (synchronous to opcode handling)
		421	or "unsafe" (asynchronous) - the former might delay signal delivery
		422	indefinitely, the latter might corrupt your memory.
		423
		424	AnyEvent signal handlers are, in addition, synchronous to the event loop,
		425	i.e. they will not interrupt your running perl program but will only be
		426	called as part of the normal event handling (just like timer, I/O etc.
		427	callbacks, too).
		428
		429	=head3 Signal Races, Delays and Workarounds
		430
		431	Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support
		432	attaching callbacks to signals in a generic way, which is a pity,
		433	as you cannot do race-free signal handling in perl, requiring
		434	C libraries for this. AnyEvent will try to do its best, which
		435	means in some cases, signals will be delayed. The maximum time
		436	a signal might be delayed is 10 seconds by default, but can
		437	be overriden via C<$ENV{PERL_ANYEVENT_MAX_SIGNAL_LATENCY}> or
		438	C<$AnyEvent::MAX_SIGNAL_LATENCY> - see the Ö<ENVIRONMENT VARIABLES>
		439	section for details.
		440
		441	All these problems can be avoided by installing the optional
		442	L<Async::Interrupt> module, which works with most event loops. It will not
		443	work with inherently broken event loops such as L<Event> or L<Event::Lib>
		444	(and not with L<POE> currently). For those, you just have to suffer the
		445	delays.
		446
346	=head2 CHILD PROCESS WATCHERS	447	=head2 CHILD PROCESS WATCHERS
347		448
		449	$w = AnyEvent->child (pid => <process id>, cb => <callback>);
		450
348	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.
349		452
350	The child process is specified by the C<pid> argument (if set to C<0>, it	453	The child process is specified by the C<pid> argument (on some backends,
351	watches for any child process exit). The watcher will triggered only when	454	using C<0> watches for any child process exit, on others this will
352	the child process has finished and an exit status is available, not on	455	croak). The watcher will be triggered only when the child process has
353	any trace events (stopped/continued).	456	finished and an exit status is available, not on any trace events
		457	(stopped/continued).
354		458
355	The callback will be called with the pid and exit status (as returned by	459	The callback will be called with the pid and exit status (as returned by
356	waitpid), so unlike other watcher types, you I<can> rely on child watcher	460	waitpid), so unlike other watcher types, you I<can> rely on child watcher
357	callback arguments.	461	callback arguments.
358		462
…		…
363		467
364	There is a slight catch to child watchers, however: you usually start them	468	There is a slight catch to child watchers, however: you usually start them
365	I<after> the child process was created, and this means the process could	469	I<after> the child process was created, and this means the process could
366	have exited already (and no SIGCHLD will be sent anymore).	470	have exited already (and no SIGCHLD will be sent anymore).
367		471
368	Not all event models handle this correctly (POE doesn't), but even for	472	Not all event models handle this correctly (neither POE nor IO::Async do,
		473	see their AnyEvent::Impl manpages for details), but even for event models
369	event models that I<do> handle this correctly, they usually need to be	474	that I<do> handle this correctly, they usually need to be loaded before
370	loaded before the process exits (i.e. before you fork in the first place).	475	the process exits (i.e. before you fork in the first place). AnyEvent's
		476	pure perl event loop handles all cases correctly regardless of when you
		477	start the watcher.
371		478
372	This means you cannot create a child watcher as the very first thing in an	479	This means you cannot create a child watcher as the very first
373	AnyEvent program, you I<have> to create at least one watcher before you	480	thing in an AnyEvent program, you I<have> to create at least one
374	C<fork> the child (alternatively, you can call C<AnyEvent::detect>).	481	watcher before you C<fork> the child (alternatively, you can call
		482	C<AnyEvent::detect>).
		483
		484	As most event loops do not support waiting for child events, they will be
		485	emulated by AnyEvent in most cases, in which case the latency and race
		486	problems mentioned in the description of signal watchers apply.
375		487
376	Example: fork a process and wait for it	488	Example: fork a process and wait for it
377		489
378	my $done = AnyEvent->condvar;	490	my $done = AnyEvent->condvar;
379		491
…		…
389	);	501	);
390		502
391	# do something else, then wait for process exit	503	# do something else, then wait for process exit
392	$done->recv;	504	$done->recv;
393		505
		506	=head2 IDLE WATCHERS
		507
		508	$w = AnyEvent->idle (cb => <callback>);
		509
		510	This will repeatedly invoke the callback after the process becomes idle,
		511	until either the watcher is destroyed or new events have been detected.
		512
		513	Idle watchers are useful when there is a need to do something, but it
		514	is not so important (or wise) to do it instantly. The callback will be
		515	invoked only when there is "nothing better to do", which is usually
		516	defined as "all outstanding events have been handled and no new events
		517	have been detected". That means that idle watchers ideally get invoked
		518	when the event loop has just polled for new events but none have been
		519	detected. Instead of blocking to wait for more events, the idle watchers
		520	will be invoked.
		521
		522	Unfortunately, most event loops do not really support idle watchers (only
		523	EV, Event and Glib do it in a usable fashion) - for the rest, AnyEvent
		524	will simply call the callback "from time to time".
		525
		526	Example: read lines from STDIN, but only process them when the
		527	program is otherwise idle:
		528
		529	my @lines; # read data
		530	my $idle_w;
		531	my $io_w = AnyEvent->io (fh => \*STDIN, poll => 'r', cb => sub {
		532	push @lines, scalar <STDIN>;
		533
		534	# start an idle watcher, if not already done
		535	$idle_w ||= AnyEvent->idle (cb => sub {
		536	# handle only one line, when there are lines left
		537	if (my $line = shift @lines) {
		538	print "handled when idle: $line";
		539	} else {
		540	# otherwise disable the idle watcher again
		541	undef $idle_w;
		542	}
		543	});
		544	});
		545
394	=head2 CONDITION VARIABLES	546	=head2 CONDITION VARIABLES
		547
		548	$cv = AnyEvent->condvar;
		549
		550	$cv->send (<list>);
		551	my @res = $cv->recv;
395		552
396	If you are familiar with some event loops you will know that all of them	553	If you are familiar with some event loops you will know that all of them
397	require you to run some blocking "loop", "run" or similar function that	554	require you to run some blocking "loop", "run" or similar function that
398	will actively watch for new events and call your callbacks.	555	will actively watch for new events and call your callbacks.
399		556
400	AnyEvent is different, it expects somebody else to run the event loop and	557	AnyEvent is slightly different: it expects somebody else to run the event
401	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).
402		559
403	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
404	because they represent a condition that must become true.	561	they represent a condition that must become true.
		562
		563	Now is probably a good time to look at the examples further below.
405		564
406	Condition variables can be created by calling the C<< AnyEvent->condvar	565	Condition variables can be created by calling the C<< AnyEvent->condvar
407	>> method, usually without arguments. The only argument pair allowed is	566	>> method, usually without arguments. The only argument pair allowed is
408
409	C<cb>, which specifies a callback to be called when the condition variable	567	C<cb>, which specifies a callback to be called when the condition variable
410	becomes true, with the condition variable as the first argument (but not	568	becomes true, with the condition variable as the first argument (but not
411	the results).	569	the results).
412		570
413	After creation, the condition variable is "false" until it becomes "true"	571	After creation, the condition variable is "false" until it becomes "true"
414	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
415	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<<
416	->send >> method).	574	->send >> method).
417		575
418	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
419	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:
420	in time where multiple outstanding events have been processed. And yet	578
421	another way to call them is transactions - each condition variable can be	579	=over 4
422	used to represent a transaction, which finishes at some point and delivers	580
423	a result.	581	=item * Condition variables are like callbacks - you can call them (and pass them instead
		582	of callbacks). Unlike callbacks however, you can also wait for them to be called.
		583
		584	=item * Condition variables are signals - one side can emit or send them,
		585	the other side can wait for them, or install a handler that is called when
		586	the signal fires.
		587
		588	=item * Condition variables are like "Merge Points" - points in your program
		589	where you merge multiple independent results/control flows into one.
		590
		591	=item * Condition variables represent a transaction - functions that start
		592	some kind of transaction can return them, leaving the caller the choice
		593	between waiting in a blocking fashion, or setting a callback.
		594
		595	=item * Condition variables represent future values, or promises to deliver
		596	some result, long before the result is available.
		597
		598	=back
424		599
425	Condition variables are very useful to signal that something has finished,	600	Condition variables are very useful to signal that something has finished,
426	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,
427	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
428	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
…		…
441		616
442	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
443	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
444	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
445	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
446	it's C<new> method in your own C<new> method.	621	its C<new> method in your own C<new> method.
447		622
448	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
449	eventually calls C<< -> send >>, and the "consumer side", which waits	624	eventually calls C<< -> send >>, and the "consumer side", which waits
450	for the send to occur.	625	for the send to occur.
451		626
452	Example: wait for a timer.	627	Example: wait for a timer.
453		628
454	# wait till the result is ready	629	# condition: "wait till the timer is fired"
455	my $result_ready = AnyEvent->condvar;	630	my $timer_fired = AnyEvent->condvar;
456		631
457	# do something such as adding a timer	632	# create the timer - we could wait for, say
458	# or socket watcher the calls $result_ready->send	633	# a handle becomign ready, or even an
459	# when the "result" is ready.	634	# AnyEvent::HTTP request to finish, but
460	# in this case, we simply use a timer:	635	# in this case, we simply use a timer:
461	my $w = AnyEvent->timer (	636	my $w = AnyEvent->timer (
462	after => 1,	637	after => 1,
463	cb => sub { $result_ready->send },	638	cb => sub { $timer_fired->send },
464	);	639	);
465		640
466	# this "blocks" (while handling events) till the callback	641	# this "blocks" (while handling events) till the callback
467	# calls send	642	# calls ->send
468	$result_ready->recv;	643	$timer_fired->recv;
469		644
470	Example: wait for a timer, but take advantage of the fact that	645	Example: wait for a timer, but take advantage of the fact that condition
471	condition variables are also code references.	646	variables are also callable directly.
472		647
473	my $done = AnyEvent->condvar;	648	my $done = AnyEvent->condvar;
474	my $delay = AnyEvent->timer (after => 5, cb => $done);	649	my $delay = AnyEvent->timer (after => 5, cb => $done);
475	$done->recv;	650	$done->recv;
476		651
…		…
482		657
483	...	658	...
484		659
485	my @info = $couchdb->info->recv;	660	my @info = $couchdb->info->recv;
486		661
487	And this is how you would just ste a callback to be called whenever the	662	And this is how you would just set a callback to be called whenever the
488	results are available:	663	results are available:
489		664
490	$couchdb->info->cb (sub {	665	$couchdb->info->cb (sub {
491	my @info = $_[0]->recv;	666	my @info = $_[0]->recv;
492	});	667	});
…		…
510	immediately from within send.	685	immediately from within send.
511		686
512	Any arguments passed to the C<send> call will be returned by all	687	Any arguments passed to the C<send> call will be returned by all
513	future C<< ->recv >> calls.	688	future C<< ->recv >> calls.
514		689
515	Condition variables are overloaded so one can call them directly	690	Condition variables are overloaded so one can call them directly (as if
516	(as 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
517	C<send>. Note, however, that many C-based event loops do not handle	692	C<send>.
518	overloading, so as tempting as it may be, passing a condition variable
519	instead of a callback does not work. Both the pure perl and EV loops
520	support overloading, however, as well as all functions that use perl to
521	invoke a callback (as in L<AnyEvent::Socket> and L<AnyEvent::DNS> for
522	example).
523		693
524	=item $cv->croak ($error)	694	=item $cv->croak ($error)
525		695
526	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
527	C<Carp::croak> with the given error message/object/scalar.	697	C<Carp::croak> with the given error message/object/scalar.
528		698
529	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
530	user/consumer.	700	user/consumer. Doing it this way instead of calling C<croak> directly
		701	delays the error detection, but has the overwhelming advantage that it
		702	diagnoses the error at the place where the result is expected, and not
		703	deep in some event callback with no connection to the actual code causing
		704	the problem.
531		705
532	=item $cv->begin ([group callback])	706	=item $cv->begin ([group callback])
533		707
534	=item $cv->end	708	=item $cv->end
535
536	These two methods are EXPERIMENTAL and MIGHT CHANGE.
537		709
538	These two methods can be used to combine many transactions/events into	710	These two methods can be used to combine many transactions/events into
539	one. For example, a function that pings many hosts in parallel might want	711	one. For example, a function that pings many hosts in parallel might want
540	to use a condition variable for the whole process.	712	to use a condition variable for the whole process.
541		713
542	Every call to C<< ->begin >> will increment a counter, and every call to	714	Every call to C<< ->begin >> will increment a counter, and every call to
543	C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end	715	C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end
544	>>, the (last) callback passed to C<begin> will be executed. That callback	716	>>, the (last) callback passed to C<begin> will be executed, passing the
545	is I<supposed> to call C<< ->send >>, but that is not required. If no	717	condvar as first argument. That callback is I<supposed> to call C<< ->send
546	callback was set, C<send> will be called without any arguments.	718	>>, but that is not required. If no group callback was set, C<send> will
		719	be called without any arguments.
547		720
548	Let's clarify this with the ping example:	721	You can think of C<< $cv->send >> giving you an OR condition (one call
		722	sends), while C<< $cv->begin >> and C<< $cv->end >> giving you an AND
		723	condition (all C<begin> calls must be C<end>'ed before the condvar sends).
		724
		725	Let's start with a simple example: you have two I/O watchers (for example,
		726	STDOUT and STDERR for a program), and you want to wait for both streams to
		727	close before activating a condvar:
549		728
550	my $cv = AnyEvent->condvar;	729	my $cv = AnyEvent->condvar;
551		730
		731	$cv->begin; # first watcher
		732	my $w1 = AnyEvent->io (fh => $fh1, cb => sub {
		733	defined sysread $fh1, my $buf, 4096
		734	or $cv->end;
		735	});
		736
		737	$cv->begin; # second watcher
		738	my $w2 = AnyEvent->io (fh => $fh2, cb => sub {
		739	defined sysread $fh2, my $buf, 4096
		740	or $cv->end;
		741	});
		742
		743	$cv->recv;
		744
		745	This works because for every event source (EOF on file handle), there is
		746	one call to C<begin>, so the condvar waits for all calls to C<end> before
		747	sending.
		748
		749	The ping example mentioned above is slightly more complicated, as the
		750	there are results to be passwd back, and the number of tasks that are
		751	begun can potentially be zero:
		752
		753	my $cv = AnyEvent->condvar;
		754
552	my %result;	755	my %result;
553	$cv->begin (sub { $cv->send (\%result) });	756	$cv->begin (sub { shift->send (\%result) });
554		757
555	for my $host (@list_of_hosts) {	758	for my $host (@list_of_hosts) {
556	$cv->begin;	759	$cv->begin;
557	ping_host_then_call_callback $host, sub {	760	ping_host_then_call_callback $host, sub {
558	$result{$host} = ...;	761	$result{$host} = ...;
…		…
573	loop, which serves two important purposes: first, it sets the callback	776	loop, which serves two important purposes: first, it sets the callback
574	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
575	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
576	doesn't execute once).	779	doesn't execute once).
577		780
578	This is the general pattern when you "fan out" into multiple subrequests:	781	This is the general pattern when you "fan out" into multiple (but
579	use an outer C<begin>/C<end> pair to set the callback and ensure C<end>	782	potentially zero) subrequests: use an outer C<begin>/C<end> pair to set
580	is called at least once, and then, for each subrequest you start, call	783	the callback and ensure C<end> is called at least once, and then, for each
581	C<begin> and for each subrequest you finish, call C<end>.	784	subrequest you start, call C<begin> and for each subrequest you finish,
		785	call C<end>.
582		786
583	=back	787	=back
584		788
585	=head3 METHODS FOR CONSUMERS	789	=head3 METHODS FOR CONSUMERS
586		790
…		…
590	=over 4	794	=over 4
591		795
592	=item $cv->recv	796	=item $cv->recv
593		797
594	Wait (blocking if necessary) until the C<< ->send >> or C<< ->croak	798	Wait (blocking if necessary) until the C<< ->send >> or C<< ->croak
595	>> methods have been called on c<$cv>, while servicing other watchers	799	>> methods have been called on C<$cv>, while servicing other watchers
596	normally.	800	normally.
597		801
598	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
599	will return immediately.	803	will return immediately.
600		804
…		…
602	function will call C<croak>.	806	function will call C<croak>.
603		807
604	In list context, all parameters passed to C<send> will be returned,	808	In list context, all parameters passed to C<send> will be returned,
605	in scalar context only the first one will be returned.	809	in scalar context only the first one will be returned.
606		810
		811	Note that doing a blocking wait in a callback is not supported by any
		812	event loop, that is, recursive invocation of a blocking C<< ->recv
		813	>> is not allowed, and the C<recv> call will C<croak> if such a
		814	condition is detected. This condition can be slightly loosened by using
		815	L<Coro::AnyEvent>, which allows you to do a blocking C<< ->recv >> from
		816	any thread that doesn't run the event loop itself.
		817
607	Not all event models support a blocking wait - some die in that case	818	Not all event models support a blocking wait - some die in that case
608	(programs might want to do that to stay interactive), so I<if you are	819	(programs might want to do that to stay interactive), so I<if you are
609	using this from a module, never require a blocking wait>, but let the	820	using this from a module, never require a blocking wait>. Instead, let the
610	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
611	condition variables with some kind of request results and supporting	822	condition variables with some kind of request results and supporting
612	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,
613	while still supporting blocking waits if the caller so desires).	824	while still supporting blocking waits if the caller so desires).
614		825
615	Another reason I<never> to C<< ->recv >> in a module is that you cannot
616	sensibly have two C<< ->recv >>'s in parallel, as that would require
617	multiple interpreters or coroutines/threads, none of which C<AnyEvent>
618	can supply.
619
620	The L<Coro> module, however, I<can> and I<does> supply coroutines and, in
621	fact, L<Coro::AnyEvent> replaces AnyEvent's condvars by coroutine-safe
622	versions and also integrates coroutines into AnyEvent, making blocking
623	C<< ->recv >> calls perfectly safe as long as they are done from another
624	coroutine (one that doesn't run the event loop).
625
626	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
627	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
628	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
629	waits otherwise.	829	waits otherwise.
630		830
631	=item $bool = $cv->ready	831	=item $bool = $cv->ready
…		…
637		837
638	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
639	replaces it before doing so.	839	replaces it before doing so.
640		840
641	The callback will be called when the condition becomes "true", i.e. when	841	The callback will be called when the condition becomes "true", i.e. when
642	C<send> or C<croak> are called, with the only argument being the condition	842	C<send> or C<croak> are called, with the only argument being the
643	variable itself. Calling C<recv> inside the callback or at any later time	843	condition variable itself. If the condition is already true, the
644	is guaranteed not to block.	844	callback is called immediately when it is set. Calling C<recv> inside
		845	the callback or at any later time is guaranteed not to block.
645		846
646	=back	847	=back
647		848
		849	=head1 SUPPORTED EVENT LOOPS/BACKENDS
		850
		851	The available backend classes are (every class has its own manpage):
		852
		853	=over 4
		854
		855	=item Backends that are autoprobed when no other event loop can be found.
		856
		857	EV is the preferred backend when no other event loop seems to be in
		858	use. If EV is not installed, then AnyEvent will fall back to its own
		859	pure-perl implementation, which is available everywhere as it comes with
		860	AnyEvent itself.
		861
		862	AnyEvent::Impl::EV based on EV (interface to libev, best choice).
		863	AnyEvent::Impl::Perl pure-perl AnyEvent::Loop, fast and portable.
		864
		865	=item Backends that are transparently being picked up when they are used.
		866
		867	These will be used if they are already loaded when the first watcher
		868	is created, in which case it is assumed that the application is using
		869	them. This means that AnyEvent will automatically pick the right backend
		870	when the main program loads an event module before anything starts to
		871	create watchers. Nothing special needs to be done by the main program.
		872
		873	AnyEvent::Impl::Event based on Event, very stable, few glitches.
		874	AnyEvent::Impl::Glib based on Glib, slow but very stable.
		875	AnyEvent::Impl::Tk based on Tk, very broken.
		876	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
		877	AnyEvent::Impl::POE based on POE, very slow, some limitations.
		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).
		882
		883	=item Backends with special needs.
		884
		885	Qt requires the Qt::Application to be instantiated first, but will
		886	otherwise be picked up automatically. As long as the main program
		887	instantiates the application before any AnyEvent watchers are created,
		888	everything should just work.
		889
		890	AnyEvent::Impl::Qt based on Qt.
		891
		892	=item Event loops that are indirectly supported via other backends.
		893
		894	Some event loops can be supported via other modules:
		895
		896	There is no direct support for WxWidgets (L<Wx>) or L<Prima>.
		897
		898	B<WxWidgets> has no support for watching file handles. However, you can
		899	use WxWidgets through the POE adaptor, as POE has a Wx backend that simply
		900	polls 20 times per second, which was considered to be too horrible to even
		901	consider for AnyEvent.
		902
		903	B<Prima> is not supported as nobody seems to be using it, but it has a POE
		904	backend, so it can be supported through POE.
		905
		906	AnyEvent knows about both L<Prima> and L<Wx>, however, and will try to
		907	load L<POE> when detecting them, in the hope that POE will pick them up,
		908	in which case everything will be automatic.
		909
		910	=back
		911
648	=head1 GLOBAL VARIABLES AND FUNCTIONS	912	=head1 GLOBAL VARIABLES AND FUNCTIONS
649		913
		914	These are not normally required to use AnyEvent, but can be useful to
		915	write AnyEvent extension modules.
		916
650	=over 4	917	=over 4
651		918
652	=item $AnyEvent::MODEL	919	=item $AnyEvent::MODEL
653		920
654	Contains C<undef> until the first watcher is being created. Then it	921	Contains C<undef> until the first watcher is being created, before the
		922	backend has been autodetected.
		923
655	contains the event model that is being used, which is the name of the	924	Afterwards it contains the event model that is being used, which is the
656	Perl class implementing the model. This class is usually one of the	925	name of the Perl class implementing the model. This class is usually one
657	C<AnyEvent::Impl:xxx> modules, but can be any other class in the case	926	of the C<AnyEvent::Impl::xxx> modules, but can be any other class in the
658	AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode>).	927	case AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode> it
659		928	will be C<urxvt::anyevent>).
660	The known classes so far are:
661
662	AnyEvent::Impl::EV based on EV (an interface to libev, best choice).
663	AnyEvent::Impl::Event based on Event, second best choice.
664	AnyEvent::Impl::Perl pure-perl implementation, fast and portable.
665	AnyEvent::Impl::Glib based on Glib, third-best choice.
666	AnyEvent::Impl::Tk based on Tk, very bad choice.
667	AnyEvent::Impl::Qt based on Qt, cannot be autoprobed (see its docs).
668	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
669	AnyEvent::Impl::POE based on POE, not generic enough for full support.
670
671	There is no support for WxWidgets, as WxWidgets has no support for
672	watching file handles. However, you can use WxWidgets through the
673	POE Adaptor, as POE has a Wx backend that simply polls 20 times per
674	second, which was considered to be too horrible to even consider for
675	AnyEvent. Likewise, other POE backends can be used by AnyEvent by using
676	it's adaptor.
677
678	AnyEvent knows about L<Prima> and L<Wx> and will try to use L<POE> when
679	autodetecting them.
680		929
681	=item AnyEvent::detect	930	=item AnyEvent::detect
682		931
683	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model	932	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model
684	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
685	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
686	runtime.	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).
		940
		941	If you need to do some initialisation before AnyEvent watchers are
		942	created, use C<post_detect>.
687		943
688	=item $guard = AnyEvent::post_detect { BLOCK }	944	=item $guard = AnyEvent::post_detect { BLOCK }
689		945
690	Arranges for the code block to be executed as soon as the event model is	946	Arranges for the code block to be executed as soon as the event model is
691	autodetected (or immediately if this has already happened).	947	autodetected (or immediately if that has already happened).
		948
		949	The block will be executed I<after> the actual backend has been detected
		950	(C<$AnyEvent::MODEL> is set), but I<before> any watchers have been
		951	created, so it is possible to e.g. patch C<@AnyEvent::ISA> or do
		952	other initialisations - see the sources of L<AnyEvent::Strict> or
		953	L<AnyEvent::AIO> to see how this is used.
		954
		955	The most common usage is to create some global watchers, without forcing
		956	event module detection too early, for example, L<AnyEvent::AIO> creates
		957	and installs the global L<IO::AIO> watcher in a C<post_detect> block to
		958	avoid autodetecting the event module at load time.
692		959
693	If called in scalar or list context, then it creates and returns an object	960	If called in scalar or list context, then it creates and returns an object
694	that automatically removes the callback again when it is destroyed. See	961	that automatically removes the callback again when it is destroyed (or
		962	C<undef> when the hook was immediately executed). See L<AnyEvent::AIO> for
695	L<Coro::BDB> for a case where this is useful.	963	a case where this is useful.
		964
		965	Example: Create a watcher for the IO::AIO module and store it in
		966	C<$WATCHER>, but do so only do so after the event loop is initialised.
		967
		968	our WATCHER;
		969
		970	my $guard = AnyEvent::post_detect {
		971	$WATCHER = AnyEvent->io (fh => IO::AIO::poll_fileno, poll => 'r', cb => \&IO::AIO::poll_cb);
		972	};
		973
		974	# the ||= is important in case post_detect immediately runs the block,
		975	# as to not clobber the newly-created watcher. assigning both watcher and
		976	# post_detect guard to the same variable has the advantage of users being
		977	# able to just C<undef $WATCHER> if the watcher causes them grief.
		978
		979	$WATCHER ||= $guard;
696		980
697	=item @AnyEvent::post_detect	981	=item @AnyEvent::post_detect
698		982
699	If there are any code references in this array (you can C<push> to it	983	If there are any code references in this array (you can C<push> to it
700	before or after loading AnyEvent), then they will called directly after	984	before or after loading AnyEvent), then they will be called directly
701	the event loop has been chosen.	985	after the event loop has been chosen.
702		986
703	You should check C<$AnyEvent::MODEL> before adding to this array, though:	987	You should check C<$AnyEvent::MODEL> before adding to this array, though:
704	if it contains a true value then the event loop has already been detected,	988	if it is defined then the event loop has already been detected, and the
705	and the array will be ignored.	989	array will be ignored.
706		990
707	Best use C<AnyEvent::post_detect { BLOCK }> instead.	991	Best use C<AnyEvent::post_detect { BLOCK }> when your application allows
		992	it, as it takes care of these details.
		993
		994	This variable is mainly useful for modules that can do something useful
		995	when AnyEvent is used and thus want to know when it is initialised, but do
		996	not need to even load it by default. This array provides the means to hook
		997	into AnyEvent passively, without loading it.
		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.
708		1069
709	=back	1070	=back
710		1071
711	=head1 WHAT TO DO IN A MODULE	1072	=head1 WHAT TO DO IN A MODULE
712		1073
…		…
723	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
724	events is to stay interactive.	1085	events is to stay interactive.
725		1086
726	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
727	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
728	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 >>
729	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).
730		1091
731	=head1 WHAT TO DO IN THE MAIN PROGRAM	1092	=head1 WHAT TO DO IN THE MAIN PROGRAM
732		1093
733	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
734	dictate which event model to use.	1095	dictate which event model to use.
735		1096
736	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
737	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
738	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.
739		1102
740	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
741	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
742	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
743	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
744	modules might create watchers when they are loaded, and AnyEvent will	1107	modules might create watchers when they are loaded, and AnyEvent will
745	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
746	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.
747		1110
748	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
749	C<AnyEvent::Impl::Perl> module, which gives you similar behaviour	1112	C<AnyEvent::Loop> module, which gives you similar behaviour
750	everywhere, but letting AnyEvent chose the model is generally better.	1113	everywhere, but letting AnyEvent chose the model is generally better.
751		1114
752	=head2 MAINLOOP EMULATION	1115	=head2 MAINLOOP EMULATION
753		1116
754	Sometimes (often for short test scripts, or even standalone programs who	1117	Sometimes (often for short test scripts, or even standalone programs who
…		…
767		1130
768		1131
769	=head1 OTHER MODULES	1132	=head1 OTHER MODULES
770		1133
771	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
772	AnyEvent and can therefore be mixed easily with other AnyEvent modules	1135	AnyEvent as a client and can therefore be mixed easily with other
773	in the same program. Some of the modules come with AnyEvent, some are	1136	AnyEvent modules and other event loops in the same program. Some of the
774	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 :)
775		1141
776	=over 4	1142	=over 4
777		1143
778	=item L<AnyEvent::Util>	1144	=item L<AnyEvent::Util>
779		1145
780	Contains various utility functions that replace often-used but blocking	1146	Contains various utility functions that replace often-used blocking
781	functions such as C<inet_aton> by event-/callback-based versions.	1147	functions such as C<inet_aton> with event/callback-based versions.
782		1148
783	=item L<AnyEvent::Socket>	1149	=item L<AnyEvent::Socket>
784		1150
785	Provides various utility functions for (internet protocol) sockets,	1151	Provides various utility functions for (internet protocol) sockets,
786	addresses and name resolution. Also functions to create non-blocking tcp	1152	addresses and name resolution. Also functions to create non-blocking tcp
…		…
788		1154
789	=item L<AnyEvent::Handle>	1155	=item L<AnyEvent::Handle>
790		1156
791	Provide read and write buffers, manages watchers for reads and writes,	1157	Provide read and write buffers, manages watchers for reads and writes,
792	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
793	non-blocking SSL/TLS.	1159	non-blocking SSL/TLS (via L<AnyEvent::TLS>).
794		1160
795	=item L<AnyEvent::DNS>	1161	=item L<AnyEvent::DNS>
796		1162
797	Provides rich asynchronous DNS resolver capabilities.	1163	Provides rich asynchronous DNS resolver capabilities.
798		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
799	=item L<AnyEvent::HTTP>	1171	=item L<AnyEvent::AIO>
800		1172
801	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
802	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.
803		1195
804	=item L<AnyEvent::HTTPD>	1196	=item L<AnyEvent::HTTPD>
805		1197
806	Provides a simple web application server framework.	1198	A simple embedded webserver.
807		1199
808	=item L<AnyEvent::FastPing>	1200	=item L<AnyEvent::FastPing>
809		1201
810	The fastest ping in the west.	1202	The fastest ping in the west.
811		1203
812	=item L<AnyEvent::DBI>
813
814	Executes L<DBI> requests asynchronously in a proxy process.
815
816	=item L<AnyEvent::AIO>
817
818	Truly asynchronous I/O, should be in the toolbox of every event
819	programmer. AnyEvent::AIO transparently fuses L<IO::AIO> and AnyEvent
820	together.
821
822	=item L<AnyEvent::BDB>
823
824	Truly asynchronous Berkeley DB access. AnyEvent::BDB transparently fuses
825	L<BDB> and AnyEvent together.
826
827	=item L<AnyEvent::GPSD>
828
829	A non-blocking interface to gpsd, a daemon delivering GPS information.
830
831	=item L<AnyEvent::IGS>
832
833	A non-blocking interface to the Internet Go Server protocol (used by
834	L<App::IGS>).
835
836	=item L<AnyEvent::IRC>
837
838	AnyEvent based IRC client module family (replacing the older Net::IRC3).
839
840	=item L<Net::XMPP2>
841
842	AnyEvent based XMPP (Jabber protocol) module family.
843
844	=item L<Net::FCP>
845
846	AnyEvent-based implementation of the Freenet Client Protocol, birthplace
847	of AnyEvent.
848
849	=item L<Event::ExecFlow>
850
851	High level API for event-based execution flow control.
852
853	=item L<Coro>	1204	=item L<Coro>
854		1205
855	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:
856		1208
857	=item L<IO::Lambda>	1209	async {
		1210	Coro::AnyEvent::sleep 5; # creates a 5s timer and waits for it
		1211	print "5 seconds later!\n";
858		1212
859	The lambda approach to I/O - don't ask, look there. Can use AnyEvent.	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	};
860		1219
861	=back	1220	=back
862		1221
863	=cut	1222	=cut
864		1223
865	package AnyEvent;	1224	package AnyEvent;
866		1225
867	no warnings;	1226	# basically a tuned-down version of common::sense
868	use strict qw(vars subs);	1227	sub common_sense {
		1228	# from common:.sense 3.4
		1229	${^WARNING_BITS} ^= ${^WARNING_BITS} ^ "\x3c\x3f\x33\x00\x0f\xf0\x0f\xc0\xf0\xfc\x33\x00";
		1230	# use strict vars subs - NO UTF-8, as Util.pm doesn't like this atm. (uts46data.pl)
		1231	$^H |= 0x00000600;
		1232	}
869		1233
		1234	BEGIN { AnyEvent::common_sense }
		1235
870	use Carp;	1236	use Carp ();
871		1237
872	our $VERSION = 4.341;	1238	our $VERSION = '6.02';
873	our $MODEL;	1239	our $MODEL;
874
875	our $AUTOLOAD;
876	our @ISA;	1240	our @ISA;
877
878	our @REGISTRY;	1241	our @REGISTRY;
879		1242	our $VERBOSE;
880	our $WIN32;	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!)
881		1245
882	BEGIN {	1246	BEGIN {
883	my $win32 = ! ! ($^O =~ /mswin32/i);	1247	require "AnyEvent/constants.pl";
884	eval "sub WIN32(){ $win32 }";
885	}
886		1248
887	our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1;	1249	eval "sub TAINT (){" . (${^TAINT}*1) . "}";
888		1250
889	our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred	1251	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}
		1252	if ${^TAINT};
890		1253
891	{	1254	$ENV{"PERL_ANYEVENT_$_"} = $ENV{"AE_$_"}
		1255	for grep s/^AE_// && !exists $ENV{"PERL_ANYEVENT_$_"}, keys %ENV;
		1256
		1257	@ENV{grep /^PERL_ANYEVENT_/, keys %ENV} = ()
		1258	if ${^TAINT};
		1259
		1260	# $ENV{PERL_ANYEVENT_xxx} now valid
		1261
		1262	$VERBOSE = length $ENV{PERL_ANYEVENT_VERBOSE} ? $ENV{PERL_ANYEVENT_VERBOSE}*1 : 4;
		1263
892	my $idx;	1264	my $idx;
893	$PROTOCOL{$_} = ++$idx	1265	$PROTOCOL{$_} = ++$idx
894	for reverse split /\s*,\s*/,	1266	for reverse split /\s*,\s*/,
895	$ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";	1267	$ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";
896	}	1268	}
897		1269
		1270	our @post_detect;
		1271
		1272	sub post_detect(&) {
		1273	my ($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
898	my @models = (	1352	our @models = (
899	[EV:: => AnyEvent::Impl::EV::],	1353	[EV:: => AnyEvent::Impl::EV::],
900	[Event:: => AnyEvent::Impl::Event::],
901	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::],	1354	[AnyEvent::Loop:: => AnyEvent::Impl::Perl::],
902	# everything below here will not be autoprobed	1355	# everything below here will not (normally) be autoprobed
903	# as the pureperl backend should work everywhere	1356	# as the pure perl backend should work everywhere
904	# 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
		1359	[Event:: => AnyEvent::Impl::Event::], # slow, stable
		1360	[Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers
		1361	# everything below here should not be autoloaded
		1362	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
905	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles	1363	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
906	[Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers
907	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
908	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program	1364	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program
909	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza	1365	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
910	[Wx:: => AnyEvent::Impl::POE::],	1366	[Wx:: => AnyEvent::Impl::POE::],
911	[Prima:: => AnyEvent::Impl::POE::],	1367	[Prima:: => AnyEvent::Impl::POE::],
		1368	[IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # a bitch to autodetect
		1369	[Cocoa::EventLoop:: => AnyEvent::Impl::Cocoa::],
		1370	[FLTK:: => AnyEvent::Impl::FLTK::],
912	);	1371	);
913		1372
914	our %method = map +($_ => 1), qw(io timer time now signal child condvar one_event DESTROY);	1373	our @isa_hook;
915		1374
916	our @post_detect;	1375	sub _isa_set {
		1376	my @pkg = ("AnyEvent", (map $_->[0], grep defined, @isa_hook), $MODEL);
917		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, $reset_ae] : undef;
		1390
		1391	_isa_set;
		1392	}
		1393
		1394	# all autoloaded methods reserve the complete glob, not just the method slot.
		1395	# due to bugs in perls method cache implementation.
		1396	our @methods = qw(io timer time now now_update signal child idle condvar);
		1397
918	sub post_detect(&) {	1398	sub detect() {
919	my ($cb) = @_;	1399	return $MODEL if $MODEL; # some programs keep references to detect
920		1400
921	if ($MODEL) {	1401	# IO::Async::Loop::AnyEvent is extremely evil, refuse to work with it
922	$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"};
923		1408
924	1	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;
925	} else {	1428	} else {
926	push @post_detect, $cb;	1429	AnyEvent::log 4 => "unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@";
927		1430	}
928	defined wantarray
929	? bless \$cb, "AnyEvent::Util::PostDetect"
930	: ()
931	}	1431	}
932	}
933		1432
934	sub AnyEvent::Util::PostDetect::DESTROY {	1433	# check for already loaded models
935	@post_detect = grep $_ != ${$_[0]}, @post_detect;
936	}
937
938	sub detect() {
939	unless ($MODEL) {	1434	unless ($MODEL) {
940	no strict 'refs';	1435	for (@REGISTRY, @models) {
941	local $SIG{__DIE__};	1436	my ($package, $model) = @$_;
942		1437	if (${"$package\::VERSION"} > 0) {
943	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {
944	my $model = "AnyEvent::Impl::$1";
945	if (eval "require $model") {	1438	if (eval "require $model") {
		1439	AnyEvent::log 7 => "autodetected model '$model', using it.";
946	$MODEL = $model;	1440	$MODEL = $model;
947	warn "AnyEvent: loaded model '$model' (forced by \$PERL_ANYEVENT_MODEL), using it.\n" if $verbose > 1;	1441	last;
948	} else {	1442	}
949	warn "AnyEvent: unable to load model '$model' (from \$PERL_ANYEVENT_MODEL):\n$@" if $verbose;
950	}	1443	}
951	}	1444	}
952		1445
953	# check for already loaded models
954	unless ($MODEL) {	1446	unless ($MODEL) {
		1447	# try to autoload a model
955	for (@REGISTRY, @models) {	1448	for (@REGISTRY, @models) {
956	my ($package, $model) = @$_;	1449	my ($package, $model) = @$_;
		1450	if (
		1451	eval "require $package"
957	if (${"$package\::VERSION"} > 0) {	1452	and ${"$package\::VERSION"} > 0
958	if (eval "require $model") {	1453	and eval "require $model"
		1454	) {
		1455	AnyEvent::log 7 => "autoloaded model '$model', using it.";
959	$MODEL = $model;	1456	$MODEL = $model;
960	warn "AnyEvent: autodetected model '$model', using it.\n" if $verbose > 1;
961	last;	1457	last;
962	}
963	}	1458	}
964	}	1459	}
965		1460
966	unless ($MODEL) {
967	# try to load a model
968
969	for (@REGISTRY, @models) {
970	my ($package, $model) = @$_;
971	if (eval "require $package"
972	and ${"$package\::VERSION"} > 0
973	and eval "require $model") {
974	$MODEL = $model;
975	warn "AnyEvent: autoprobed model '$model', using it.\n" if $verbose > 1;
976	last;
977	}
978	}
979
980	$MODEL	1461	$MODEL
981	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.";	1462	or AnyEvent::log fatal => "AnyEvent: backend autodetection failed - did you properly install AnyEvent?";
982	}
983	}	1463	}
984
985	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
986
987	unshift @ISA, $MODEL;
988
989	require AnyEvent::Strict if $ENV{PERL_ANYEVENT_STRICT};
990
991	(shift @post_detect)->() while @post_detect;
992	}	1464	}
993		1465
		1466	# free memory only needed for probing
		1467	undef @models;
		1468	undef @REGISTRY;
		1469
		1470	push @{"$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/\$\$/$$/g;
		1498
		1499	my ($host, $service) = AnyEvent::Socket::parse_hostport ($shell);
		1500	$AnyEvent::Debug::SHELL = AnyEvent::Debug::shell ($host, $service);
		1501	}
		1502
		1503	# now the anyevent environment is set up as the user told us to, so
		1504	# call the actual user code - post detects
		1505
		1506	(shift @post_detect)->() while @post_detect;
		1507	undef @post_detect;
		1508
		1509	*post_detect = sub(&) {
		1510	shift->();
		1511
		1512	undef
		1513	};
		1514
994	$MODEL	1515	$MODEL
995	}	1516	}
996		1517
997	sub AUTOLOAD {	1518	for my $name (@methods) {
998	(my $func = $AUTOLOAD) =~ s/.*://;	1519	*$name = sub {
999		1520	detect;
1000	$method{$func}	1521	# we use goto because
1001	or croak "$func: not a valid method for AnyEvent objects";	1522	# a) it makes the thunk more transparent
1002		1523	# b) it allows us to delete the thunk later
1003	detect unless $MODEL;	1524	goto &{ UNIVERSAL::can AnyEvent => "SUPER::$name" }
1004		1525	};
1005	my $class = shift;
1006	$class->$func (@_);
1007	}	1526	}
1008		1527
1009	# utility function to dup a filehandle. this is used by many backends	1528	# utility function to dup a filehandle. this is used by many backends
1010	# to support binding more than one watcher per filehandle (they usually	1529	# to support binding more than one watcher per filehandle (they usually
1011	# allow only one watcher per fd, so we dup it to get a different one).	1530	# allow only one watcher per fd, so we dup it to get a different one).
1012	sub _dupfh($$$$) {	1531	sub _dupfh($$;$$) {
1013	my ($poll, $fh, $r, $w) = @_;	1532	my ($poll, $fh, $r, $w) = @_;
1014		1533
1015	# cygwin requires the fh mode to be matching, unix doesn't	1534	# cygwin requires the fh mode to be matching, unix doesn't
1016	my ($rw, $mode) = $poll eq "r" ? ($r, "<")	1535	my ($rw, $mode) = $poll eq "r" ? ($r, "<&") : ($w, ">&");
1017	: $poll eq "w" ? ($w, ">")
1018	: Carp::croak "AnyEvent->io requires poll set to either 'r' or 'w'";
1019		1536
1020	open my $fh2, "$mode&" . fileno $fh	1537	open my $fh2, $mode, $fh
1021	or die "cannot dup() filehandle: $!";	1538	or die "AnyEvent->io: cannot dup() filehandle in mode '$poll': $!,";
1022		1539
1023	# we assume CLOEXEC is already set by perl in all important cases	1540	# we assume CLOEXEC is already set by perl in all important cases
1024		1541
1025	($fh2, $rw)	1542	($fh2, $rw)
1026	}	1543	}
1027		1544
		1545	=head1 SIMPLIFIED AE API
		1546
		1547	Starting with version 5.0, AnyEvent officially supports a second, much
		1548	simpler, API that is designed to reduce the calling, typing and memory
		1549	overhead by using function call syntax and a fixed number of parameters.
		1550
		1551	See the L<AE> manpage for details.
		1552
		1553	=cut
		1554
		1555	package AE;
		1556
		1557	our $VERSION = $AnyEvent::VERSION;
		1558
		1559	sub _reset() {
		1560	eval q{
		1561	# fall back to the main API by default - backends and AnyEvent::Base
		1562	# implementations can overwrite these.
		1563
		1564	sub io($$$) {
		1565	AnyEvent->io (fh => $_[0], poll => $_[1] ? "w" : "r", cb => $_[2])
		1566	}
		1567
		1568	sub timer($$$) {
		1569	AnyEvent->timer (after => $_[0], interval => $_[1], cb => $_[2])
		1570	}
		1571
		1572	sub signal($$) {
		1573	AnyEvent->signal (signal => $_[0], cb => $_[1])
		1574	}
		1575
		1576	sub child($$) {
		1577	AnyEvent->child (pid => $_[0], cb => $_[1])
		1578	}
		1579
		1580	sub idle($) {
		1581	AnyEvent->idle (cb => $_[0]);
		1582	}
		1583
		1584	sub cv(;&) {
		1585	AnyEvent->condvar (@_ ? (cb => $_[0]) : ())
		1586	}
		1587
		1588	sub now() {
		1589	AnyEvent->now
		1590	}
		1591
		1592	sub now_update() {
		1593	AnyEvent->now_update
		1594	}
		1595
		1596	sub time() {
		1597	AnyEvent->time
		1598	}
		1599
		1600	*postpone = \&AnyEvent::postpone;
		1601	*log = \&AnyEvent::log;
		1602	};
		1603	die if $@;
		1604	}
		1605
		1606	BEGIN { _reset }
		1607
1028	package AnyEvent::Base;	1608	package AnyEvent::Base;
1029		1609
1030	# default implementation for now and time	1610	# default implementations for many methods
1031		1611
1032	BEGIN {	1612	sub time {
		1613	eval q{ # poor man's autoloading {}
		1614	# probe for availability of Time::HiRes
1033	if (eval "use Time::HiRes (); time (); 1") {	1615	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {
		1616	*time = sub { Time::HiRes::time () };
1034	*_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.";
1035	# if (eval "use POSIX (); (POSIX::times())...	1620	# if (eval "use POSIX (); (POSIX::times())...
1036	} else {	1621	} else {
1037	*_time = sub { time }; # epic fail	1622	*time = sub { CORE::time };
		1623	*AE::time = sub (){ CORE::time };
		1624	*now = \&time;
		1625	AnyEvent::log 3 => "using built-in time(), WARNING, no sub-second resolution!";
		1626	}
		1627	};
		1628	die if $@;
		1629
		1630	&time
		1631	}
		1632
		1633	*now = \&time;
		1634	sub now_update { }
		1635
		1636	sub _poll {
		1637	Carp::croak "$AnyEvent::MODEL does not support blocking waits. Caught";
		1638	}
		1639
		1640	# default implementation for ->condvar
		1641	# in fact, the default should not be overwritten
		1642
		1643	sub condvar {
		1644	eval q{ # poor man's autoloading {}
		1645	*condvar = sub {
		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
		1656	}
		1657
		1658	# default implementation for ->signal
		1659
		1660	our $HAVE_ASYNC_INTERRUPT;
		1661
		1662	sub _have_async_interrupt() {
		1663	$HAVE_ASYNC_INTERRUPT = 1*(!$ENV{PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT}
		1664	&& eval "use Async::Interrupt 1.02 (); 1")
		1665	unless defined $HAVE_ASYNC_INTERRUPT;
		1666
		1667	$HAVE_ASYNC_INTERRUPT
		1668	}
		1669
		1670	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);
		1671	our (%SIG_ASY, %SIG_ASY_W);
		1672	our ($SIG_COUNT, $SIG_TW);
		1673
		1674	# install a dummy wakeup watcher to reduce signal catching latency
		1675	# used by Impls
		1676	sub _sig_add() {
		1677	unless ($SIG_COUNT++) {
		1678	# try to align timer on a full-second boundary, if possible
		1679	my $NOW = AE::now;
		1680
		1681	$SIG_TW = AE::timer
		1682	$MAX_SIGNAL_LATENCY - ($NOW - int $NOW),
		1683	$MAX_SIGNAL_LATENCY,
		1684	sub { } # just for the PERL_ASYNC_CHECK
		1685	;
1038	}	1686	}
1039	}	1687	}
1040		1688
1041	sub time { _time }	1689	sub _sig_del {
1042	sub now { _time }	1690	undef $SIG_TW
1043		1691	unless --$SIG_COUNT;
1044	# default implementation for ->condvar
1045
1046	sub condvar {
1047	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, AnyEvent::CondVar::
1048	}	1692	}
1049		1693
1050	# default implementation for ->signal	1694	our $_sig_name_init; $_sig_name_init = sub {
		1695	eval q{ # poor man's autoloading {}
		1696	undef $_sig_name_init;
1051		1697
1052	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);	1698	if (_have_async_interrupt) {
		1699	*sig2num = \&Async::Interrupt::sig2num;
		1700	*sig2name = \&Async::Interrupt::sig2name;
		1701	} else {
		1702	require Config;
1053		1703
1054	sub _signal_exec {	1704	my %signame2num;
1055	while (%SIG_EV) {	1705	@signame2num{ split ' ', $Config::Config{sig_name} }
1056	sysread $SIGPIPE_R, my $dummy, 4;	1706	= split ' ', $Config::Config{sig_num};
1057	for (keys %SIG_EV) {	1707
1058	delete $SIG_EV{$_};	1708	my @signum2name;
1059	$_->() for values %{ $SIG_CB{$_} || {} };	1709	@signum2name[values %signame2num] = keys %signame2num;
		1710
		1711	*sig2num = sub($) {
		1712	$_[0] > 0 ? shift : $signame2num{+shift}
		1713	};
		1714	*sig2name = sub ($) {
		1715	$_[0] > 0 ? $signum2name[+shift] : shift
		1716	};
1060	}	1717	}
1061	}	1718	};
1062	}	1719	die if $@;
		1720	};
		1721
		1722	sub sig2num ($) { &$_sig_name_init; &sig2num }
		1723	sub sig2name($) { &$_sig_name_init; &sig2name }
1063		1724
1064	sub signal {	1725	sub signal {
1065	my (undef, %arg) = @_;	1726	eval q{ # poor man's autoloading {}
		1727	# probe for availability of Async::Interrupt
		1728	if (_have_async_interrupt) {
		1729	AnyEvent::log 8 => "using Async::Interrupt for race-free signal handling.";
1066		1730
1067	unless ($SIGPIPE_R) {	1731	$SIGPIPE_R = new Async::Interrupt::EventPipe;
1068	if (AnyEvent::WIN32) {	1732	$SIG_IO = AE::io $SIGPIPE_R->fileno, 0, \&_signal_exec;
1069	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();	1733
1070	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R) if $SIGPIPE_R;
1071	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W) if $SIGPIPE_W; # just in case
1072	} else {	1734	} else {
		1735	AnyEvent::log 8 => "using emulated perl signal handling with latency timer.";
		1736
		1737	if (AnyEvent::WIN32) {
		1738	require AnyEvent::Util;
		1739
		1740	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
		1741	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R, 1) if $SIGPIPE_R;
		1742	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W, 1) if $SIGPIPE_W; # just in case
		1743	} else {
1073	pipe $SIGPIPE_R, $SIGPIPE_W;	1744	pipe $SIGPIPE_R, $SIGPIPE_W;
1074	require Fcntl;
1075	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;
1076	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
		1747
		1748	# not strictly required, as $^F is normally 2, but let's make sure...
		1749	fcntl $SIGPIPE_R, AnyEvent::F_SETFD, AnyEvent::FD_CLOEXEC;
		1750	fcntl $SIGPIPE_W, AnyEvent::F_SETFD, AnyEvent::FD_CLOEXEC;
		1751	}
		1752
		1753	$SIGPIPE_R
		1754	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";
		1755
		1756	$SIG_IO = AE::io $SIGPIPE_R, 0, \&_signal_exec;
1077	}	1757	}
1078		1758
1079	$SIGPIPE_R	1759	*signal = $HAVE_ASYNC_INTERRUPT
1080	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";	1760	? sub {
		1761	my (undef, %arg) = @_;
1081		1762
1082	$SIG_IO = AnyEvent->io (fh => $SIGPIPE_R, poll => "r", cb => \&_signal_exec);	1763	# async::interrupt
1083	}
1084
1085	my $signal = uc $arg{signal}	1764	my $signal = sig2num $arg{signal};
1086	or Carp::croak "required option 'signal' is missing";
1087
1088	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};	1765	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
		1766
		1767	$SIG_ASY{$signal} ||= new Async::Interrupt
		1768	cb => sub { undef $SIG_EV{$signal} },
		1769	signal => $signal,
		1770	pipe => [$SIGPIPE_R->filenos],
		1771	pipe_autodrain => 0,
		1772	;
		1773
		1774	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
		1775	}
		1776	: sub {
		1777	my (undef, %arg) = @_;
		1778
		1779	# pure perl
		1780	my $signal = sig2name $arg{signal};
		1781	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
		1782
1089	$SIG{$signal} ||= sub {	1783	$SIG{$signal} ||= sub {
		1784	local $!;
1090	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;	1785	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;
1091	undef $SIG_EV{$signal};	1786	undef $SIG_EV{$signal};
		1787	};
		1788
		1789	# can't do signal processing without introducing races in pure perl,
		1790	# so limit the signal latency.
		1791	_sig_add;
		1792
		1793	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
		1794	}
		1795	;
		1796
		1797	*AnyEvent::Base::signal::DESTROY = sub {
		1798	my ($signal, $cb) = @{$_[0]};
		1799
		1800	_sig_del;
		1801
		1802	delete $SIG_CB{$signal}{$cb};
		1803
		1804	$HAVE_ASYNC_INTERRUPT
		1805	? delete $SIG_ASY{$signal}
		1806	: # delete doesn't work with older perls - they then
		1807	# print weird messages, or just unconditionally exit
		1808	# instead of getting the default action.
		1809	undef $SIG{$signal}
		1810	unless keys %{ $SIG_CB{$signal} };
		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	};
1092	};	1825	};
		1826	die if $@;
1093		1827
1094	bless [$signal, $arg{cb}], "AnyEvent::Base::Signal"	1828	&signal
1095	}
1096
1097	sub AnyEvent::Base::Signal::DESTROY {
1098	my ($signal, $cb) = @{$_[0]};
1099
1100	delete $SIG_CB{$signal}{$cb};
1101
1102	delete $SIG{$signal} unless keys %{ $SIG_CB{$signal} };
1103	}	1829	}
1104		1830
1105	# default implementation for ->child	1831	# default implementation for ->child
1106		1832
1107	our %PID_CB;	1833	our %PID_CB;
1108	our $CHLD_W;	1834	our $CHLD_W;
1109	our $CHLD_DELAY_W;	1835	our $CHLD_DELAY_W;
1110	our $PID_IDLE;
1111	our $WNOHANG;
1112		1836
1113	sub _child_wait {	1837	# used by many Impl's
1114	while (0 < (my $pid = waitpid -1, $WNOHANG)) {	1838	sub _emit_childstatus($$) {
		1839	my (undef, $rpid, $rstatus) = @_;
		1840
		1841	$_->($rpid, $rstatus)
1115	$_->($pid, $?) for (values %{ $PID_CB{$pid} || {} }),	1842	for values %{ $PID_CB{$rpid} || {} },
1116	(values %{ $PID_CB{0} || {} });	1843	values %{ $PID_CB{0} || {} };
1117	}
1118
1119	undef $PID_IDLE;
1120	}
1121
1122	sub _sigchld {
1123	# make sure we deliver these changes "synchronous" with the event loop.
1124	$CHLD_DELAY_W ||= AnyEvent->timer (after => 0, cb => sub {
1125	undef $CHLD_DELAY_W;
1126	&_child_wait;
1127	});
1128	}	1844	}
1129		1845
1130	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 {
1131	my (undef, %arg) = @_;	1856	my (undef, %arg) = @_;
1132		1857
1133	defined (my $pid = $arg{pid} + 0)	1858	my $pid = $arg{pid};
1134	or Carp::croak "required option 'pid' is missing";	1859	my $cb = $arg{cb};
1135		1860
1136	$PID_CB{$pid}{$arg{cb}} = $arg{cb};	1861	$PID_CB{$pid}{$cb+0} = $cb;
1137		1862
1138	unless ($WNOHANG) {
1139	$WNOHANG = eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1;
1140	}
1141
1142	unless ($CHLD_W) {	1863	unless ($CHLD_W) {
1143	$CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld);	1864	$CHLD_W = AE::signal CHLD => \&_sigchld;
1144	# child could be a zombie already, so make at least one round	1865	# child could be a zombie already, so make at least one round
1145	&_sigchld;	1866	&_sigchld;
1146	}	1867	}
1147		1868
1148	bless [$pid, $arg{cb}], "AnyEvent::Base::Child"	1869	bless [$pid, $cb+0], "AnyEvent::Base::child"
1149	}	1870	};
1150		1871
1151	sub AnyEvent::Base::Child::DESTROY {	1872	*AnyEvent::Base::child::DESTROY = sub {
1152	my ($pid, $cb) = @{$_[0]};	1873	my ($pid, $icb) = @{$_[0]};
1153		1874
1154	delete $PID_CB{$pid}{$cb};	1875	delete $PID_CB{$pid}{$icb};
1155	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };	1876	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };
1156		1877
1157	undef $CHLD_W unless keys %PID_CB;	1878	undef $CHLD_W unless keys %PID_CB;
		1879	};
		1880	};
		1881	die if $@;
		1882
		1883	&child
		1884	}
		1885
		1886	# idle emulation is done by simply using a timer, regardless
		1887	# of whether the process is idle or not, and not letting
		1888	# the callback use more than 50% of the time.
		1889	sub idle {
		1890	eval q{ # poor man's autoloading {}
		1891	*idle = sub {
		1892	my (undef, %arg) = @_;
		1893
		1894	my ($cb, $w, $rcb) = $arg{cb};
		1895
		1896	$rcb = sub {
		1897	if ($cb) {
		1898	$w = AE::time;
		1899	&$cb;
		1900	$w = AE::time - $w;
		1901
		1902	# never use more then 50% of the time for the idle watcher,
		1903	# within some limits
		1904	$w = 0.0001 if $w < 0.0001;
		1905	$w = 5 if $w > 5;
		1906
		1907	$w = AE::timer $w, 0, $rcb;
		1908	} else {
		1909	# clean up...
		1910	undef $w;
		1911	undef $rcb;
		1912	}
		1913	};
		1914
		1915	$w = AE::timer 0.05, 0, $rcb;
		1916
		1917	bless \\$cb, "AnyEvent::Base::idle"
		1918	};
		1919
		1920	*AnyEvent::Base::idle::DESTROY = sub {
		1921	undef $${$_[0]};
		1922	};
		1923	};
		1924	die if $@;
		1925
		1926	&idle
1158	}	1927	}
1159		1928
1160	package AnyEvent::CondVar;	1929	package AnyEvent::CondVar;
1161		1930
1162	our @ISA = AnyEvent::CondVar::Base::;	1931	our @ISA = AnyEvent::CondVar::Base::;
1163		1932
		1933	# only to be used for subclassing
		1934	sub new {
		1935	my $class = shift;
		1936	bless AnyEvent->condvar (@_), $class
		1937	}
		1938
1164	package AnyEvent::CondVar::Base;	1939	package AnyEvent::CondVar::Base;
1165		1940
1166	use overload	1941	#use overload
1167	'&{}' => sub { my $self = shift; sub { $self->send (@_) } },	1942	# '&{}' => sub { my $self = shift; sub { $self->send (@_) } },
1168	fallback => 1;	1943	# fallback => 1;
		1944
		1945	# save 300+ kilobytes by dirtily hardcoding overloading
		1946	${"AnyEvent::CondVar::Base::OVERLOAD"}{dummy}++; # Register with magic by touching.
		1947	*{'AnyEvent::CondVar::Base::()'} = sub { }; # "Make it findable via fetchmethod."
		1948	*{'AnyEvent::CondVar::Base::(&{}'} = sub { my $self = shift; sub { $self->send (@_) } }; # &{}
		1949	${'AnyEvent::CondVar::Base::()'} = 1; # fallback
		1950
		1951	our $WAITING;
1169		1952
1170	sub _send {	1953	sub _send {
1171	# nop	1954	# nop
		1955	}
		1956
		1957	sub _wait {
		1958	AnyEvent->_poll until $_[0]{_ae_sent};
1172	}	1959	}
1173		1960
1174	sub send {	1961	sub send {
1175	my $cv = shift;	1962	my $cv = shift;
1176	$cv->{_ae_sent} = [@_];	1963	$cv->{_ae_sent} = [@_];
…		…
1185		1972
1186	sub ready {	1973	sub ready {
1187	$_[0]{_ae_sent}	1974	$_[0]{_ae_sent}
1188	}	1975	}
1189		1976
1190	sub _wait {
1191	AnyEvent->one_event while !$_[0]{_ae_sent};
1192	}
1193
1194	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;
1195	$_[0]->_wait;	1983	$_[0]->_wait;
		1984	}
1196		1985
1197	Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak};	1986	$_[0]{_ae_croak}
1198	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]
1199	}	1992	}
1200		1993
1201	sub cb {	1994	sub cb {
1202	$_[0]{_ae_cb} = $_[1] if @_ > 1;	1995	my $cv = shift;
		1996
		1997	@_
		1998	and $cv->{_ae_cb} = shift
		1999	and $cv->{_ae_sent}
		2000	and (delete $cv->{_ae_cb})->($cv);
		2001
1203	$_[0]{_ae_cb}	2002	$cv->{_ae_cb}
1204	}	2003	}
1205		2004
1206	sub begin {	2005	sub begin {
1207	++$_[0]{_ae_counter};	2006	++$_[0]{_ae_counter};
1208	$_[0]{_ae_end_cb} = $_[1] if @_ > 1;	2007	$_[0]{_ae_end_cb} = $_[1] if @_ > 1;
…		…
1213	&{ $_[0]{_ae_end_cb} || sub { $_[0]->send } };	2012	&{ $_[0]{_ae_end_cb} || sub { $_[0]->send } };
1214	}	2013	}
1215		2014
1216	# undocumented/compatibility with pre-3.4	2015	# undocumented/compatibility with pre-3.4
1217	*broadcast = \&send;	2016	*broadcast = \&send;
1218	*wait = \&_wait;	2017	*wait = \&recv;
1219		2018
1220	=head1 ERROR AND EXCEPTION HANDLING	2019	=head1 ERROR AND EXCEPTION HANDLING
1221		2020
1222	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
1223	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
…		…
1235	$Event/EV::DIED->() >>, L<Glib> uses C<< install_exception_handler >> and	2034	$Event/EV::DIED->() >>, L<Glib> uses C<< install_exception_handler >> and
1236	so on.	2035	so on.
1237		2036
1238	=head1 ENVIRONMENT VARIABLES	2037	=head1 ENVIRONMENT VARIABLES
1239		2038
1240	The following environment variables are used by this module or its	2039	AnyEvent supports a number of environment variables that tune the
1241	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.
		2045
		2046	All the environment variables documented here start with
		2047	C<PERL_ANYEVENT_>, which is what AnyEvent considers its own
		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:
1242		2076
1243	=over 4	2077	=over 4
1244		2078
1245	=item C<PERL_ANYEVENT_VERBOSE>	2079	=item C<PERL_ANYEVENT_VERBOSE>
1246		2080
1247	By default, AnyEvent will be completely silent except in fatal	2081	By default, AnyEvent will only log messages with loglevel C<3>
1248	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
1249	talkative.	2084	less) talkative.
1250		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
1251	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
1252	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
1253	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.
1254		2097
1255	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
1256	model it chooses.	2099	chooses.
		2100
		2101	When set to C<8> or higher (debug), then AnyEvent will report extra information on
		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.
1257		2121
1258	=item C<PERL_ANYEVENT_STRICT>	2122	=item C<PERL_ANYEVENT_STRICT>
1259		2123
1260	AnyEvent does not do much argument checking by default, as thorough	2124	AnyEvent does not do much argument checking by default, as thorough
1261	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
1262	will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly	2126	will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly
1263	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,
1264	it will croak.	2128	it will croak.
1265		2129
1266	In other words, enables "strict" mode.	2130	In other words, enables "strict" mode.
1267		2131
1268	Unlike C<use strict>, it is definitely recommended ot keep it off in	2132	Unlike C<use strict> (or its modern cousin, C<< use L<common::sense>
1269	production. Keeping C<PERL_ANYEVENT_STRICT=1> in your environment while	2133	>>, it is definitely recommended to keep it off in production. Keeping
1270	developing programs can be very useful, however.	2134	C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs
		2135	can be very useful, however.
		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.
1271		2164
1272	=item C<PERL_ANYEVENT_MODEL>	2165	=item C<PERL_ANYEVENT_MODEL>
1273		2166
1274	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
1275	auto detection and -probing kicks in. It must be a string consisting	2168	auto detection and -probing kicks in.
1276	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
1277	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
1278	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
1279	auto detection and -probing.	2174	auto detection and -probing.
1280		2175
1281	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).
1282		2179
1283	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
1284	could start your program like this:	2181	could start your program like this:
1285		2182
1286	PERL_ANYEVENT_MODEL=Perl perl ...	2183	PERL_ANYEVENT_MODEL=Perl perl ...
1287		2184
1288	=item C<PERL_ANYEVENT_PROTOCOLS>	2185	=item C<PERL_ANYEVENT_PROTOCOLS>
…		…
1304	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>
1305	- only support IPv4, never try to resolve or contact IPv6	2202	- only support IPv4, never try to resolve or contact IPv6
1306	addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or	2203	addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or
1307	IPv6, but prefer IPv6 over IPv4.	2204	IPv6, but prefer IPv6 over IPv4.
1308		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
1309	=item C<PERL_ANYEVENT_EDNS0>	2212	=item C<PERL_ANYEVENT_EDNS0>
1310		2213
1311	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
1312	for DNS. This extension is generally useful to reduce DNS traffic, but	2215	DNS. This extension is generally useful to reduce DNS traffic, especially
1313	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
1314	default.	2217	packets, which is why it is off by default.
1315		2218
1316	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
1317	EDNS0 in its DNS requests.	2220	EDNS0 in its DNS requests.
1318		2221
1319	=item C<PERL_ANYEVENT_MAX_FORKS>	2222	=item C<PERL_ANYEVENT_MAX_FORKS>
1320		2223
1321	The maximum number of child processes that C<AnyEvent::Util::fork_call>	2224	The maximum number of child processes that C<AnyEvent::Util::fork_call>
1322	will create in parallel.	2225	will create in parallel.
		2226
		2227	=item C<PERL_ANYEVENT_MAX_OUTSTANDING_DNS>
		2228
		2229	The default value for the C<max_outstanding> parameter for the default DNS
		2230	resolver - this is the maximum number of parallel DNS requests that are
		2231	sent to the DNS server.
		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
		2255	=item C<PERL_ANYEVENT_RESOLV_CONF>
		2256
		2257	The absolute path to a F<resolv.conf>-style file to use instead of
		2258	F</etc/resolv.conf> (or the OS-specific configuration) in the default
		2259	resolver, or the empty string to select the default configuration.
		2260
		2261	=item C<PERL_ANYEVENT_CA_FILE>, C<PERL_ANYEVENT_CA_PATH>.
		2262
		2263	When neither C<ca_file> nor C<ca_path> was specified during
		2264	L<AnyEvent::TLS> context creation, and either of these environment
		2265	variables are nonempty, they will be used to specify CA certificate
		2266	locations instead of a system-dependent default.
		2267
		2268	=item C<PERL_ANYEVENT_AVOID_GUARD> and C<PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT>
		2269
		2270	When these are set to C<1>, then the respective modules are not
		2271	loaded. Mostly good for testing AnyEvent itself.
1323		2272
1324	=back	2273	=back
1325		2274
1326	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE	2275	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE
1327		2276
…		…
1385	warn "read: $input\n"; # output what has been read	2334	warn "read: $input\n"; # output what has been read
1386	$cv->send if $input =~ /^q/i; # quit program if /^q/i	2335	$cv->send if $input =~ /^q/i; # quit program if /^q/i
1387	},	2336	},
1388	);	2337	);
1389		2338
1390	my $time_watcher; # can only be used once
1391
1392	sub new_timer {
1393	$timer = AnyEvent->timer (after => 1, cb => sub {	2339	my $time_watcher = AnyEvent->timer (after => 1, interval => 1, cb => sub {
1394	warn "timeout\n"; # print 'timeout' about every second	2340	warn "timeout\n"; # print 'timeout' at most every second
1395	&new_timer; # and restart the time
1396	});	2341	});
1397	}
1398
1399	new_timer; # create first timer
1400		2342
1401	$cv->recv; # wait until user enters /^q/i	2343	$cv->recv; # wait until user enters /^q/i
1402		2344
1403	=head1 REAL-WORLD EXAMPLE	2345	=head1 REAL-WORLD EXAMPLE
1404		2346
…		…
1477		2419
1478	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)
1479	that occurred during request processing. The C<result> method detects	2421	that occurred during request processing. The C<result> method detects
1480	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)
1481	and just throws the exception, which means connection errors and other	2423	and just throws the exception, which means connection errors and other
1482	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
1483	random callback.	2425	random callback.
1484		2426
1485	All of this enables the following usage styles:	2427	All of this enables the following usage styles:
1486		2428
1487	1. Blocking:	2429	1. Blocking:
…		…
1535	through AnyEvent. The benchmark creates a lot of timers (with a zero	2477	through AnyEvent. The benchmark creates a lot of timers (with a zero
1536	timeout) and I/O watchers (watching STDOUT, a pty, to become writable,	2478	timeout) and I/O watchers (watching STDOUT, a pty, to become writable,
1537	which it is), lets them fire exactly once and destroys them again.	2479	which it is), lets them fire exactly once and destroys them again.
1538		2480
1539	Source code for this benchmark is found as F<eg/bench> in the AnyEvent	2481	Source code for this benchmark is found as F<eg/bench> in the AnyEvent
1540	distribution.	2482	distribution. It uses the L<AE> interface, which makes a real difference
		2483	for the EV and Perl backends only.
1541		2484
1542	=head3 Explanation of the columns	2485	=head3 Explanation of the columns
1543		2486
1544	I<watcher> is the number of event watchers created/destroyed. Since	2487	I<watcher> is the number of event watchers created/destroyed. Since
1545	different event models feature vastly different performances, each event	2488	different event models feature vastly different performances, each event
…		…
1566	watcher.	2509	watcher.
1567		2510
1568	=head3 Results	2511	=head3 Results
1569		2512
1570	name watchers bytes create invoke destroy comment	2513	name watchers bytes create invoke destroy comment
1571	EV/EV 400000 224 0.47 0.35 0.27 EV native interface	2514	EV/EV 100000 223 0.47 0.43 0.27 EV native interface
1572	EV/Any 100000 224 2.88 0.34 0.27 EV + AnyEvent watchers	2515	EV/Any 100000 223 0.48 0.42 0.26 EV + AnyEvent watchers
1573	CoroEV/Any 100000 224 2.85 0.35 0.28 coroutines + Coro::Signal	2516	Coro::EV/Any 100000 223 0.47 0.42 0.26 coroutines + Coro::Signal
1574	Perl/Any 100000 452 4.13 0.73 0.95 pure perl implementation	2517	Perl/Any 100000 431 2.70 0.74 0.92 pure perl implementation
1575	Event/Event 16000 517 32.20 31.80 0.81 Event native interface	2518	Event/Event 16000 516 31.16 31.84 0.82 Event native interface
1576	Event/Any 16000 590 35.85 31.55 1.06 Event + AnyEvent watchers	2519	Event/Any 16000 1203 42.61 34.79 1.80 Event + AnyEvent watchers
		2520	IOAsync/Any 16000 1911 41.92 27.45 16.81 via IO::Async::Loop::IO_Poll
		2521	IOAsync/Any 16000 1726 40.69 26.37 15.25 via IO::Async::Loop::Epoll
1577	Glib/Any 16000 1357 102.33 12.31 51.00 quadratic behaviour	2522	Glib/Any 16000 1118 89.00 12.57 51.17 quadratic behaviour
1578	Tk/Any 2000 1860 27.20 66.31 14.00 SEGV with >> 2000 watchers	2523	Tk/Any 2000 1346 20.96 10.75 8.00 SEGV with >> 2000 watchers
1579	POE/Event 2000 6328 109.99 751.67 14.02 via POE::Loop::Event	2524	POE/Any 2000 6951 108.97 795.32 14.24 via POE::Loop::Event
1580	POE/Select 2000 6027 94.54 809.13 579.80 via POE::Loop::Select	2525	POE/Any 2000 6648 94.79 774.40 575.51 via POE::Loop::Select
1581		2526
1582	=head3 Discussion	2527	=head3 Discussion
1583		2528
1584	The benchmark does I<not> measure scalability of the event loop very	2529	The benchmark does I<not> measure scalability of the event loop very
1585	well. For example, a select-based event loop (such as the pure perl one)	2530	well. For example, a select-based event loop (such as the pure perl one)
…		…
1597	benchmark machine, handling an event takes roughly 1600 CPU cycles with	2542	benchmark machine, handling an event takes roughly 1600 CPU cycles with
1598	EV, 3100 CPU cycles with AnyEvent's pure perl loop and almost 3000000 CPU	2543	EV, 3100 CPU cycles with AnyEvent's pure perl loop and almost 3000000 CPU
1599	cycles with POE.	2544	cycles with POE.
1600		2545
1601	C<EV> is the sole leader regarding speed and memory use, which are both	2546	C<EV> is the sole leader regarding speed and memory use, which are both
1602	maximal/minimal, respectively. Even when going through AnyEvent, it uses	2547	maximal/minimal, respectively. When using the L<AE> API there is zero
		2548	overhead (when going through the AnyEvent API create is about 5-6 times
		2549	slower, with other times being equal, so still uses far less memory than
1603	far less memory than any other event loop and is still faster than Event	2550	any other event loop and is still faster than Event natively).
1604	natively.
1605		2551
1606	The pure perl implementation is hit in a few sweet spots (both the	2552	The pure perl implementation is hit in a few sweet spots (both the
1607	constant timeout and the use of a single fd hit optimisations in the perl	2553	constant timeout and the use of a single fd hit optimisations in the perl
1608	interpreter and the backend itself). Nevertheless this shows that it	2554	interpreter and the backend itself). Nevertheless this shows that it
1609	adds very little overhead in itself. Like any select-based backend its	2555	adds very little overhead in itself. Like any select-based backend its
1610	performance becomes really bad with lots of file descriptors (and few of	2556	performance becomes really bad with lots of file descriptors (and few of
1611	them active), of course, but this was not subject of this benchmark.	2557	them active), of course, but this was not subject of this benchmark.
1612		2558
1613	The C<Event> module has a relatively high setup and callback invocation	2559	The C<Event> module has a relatively high setup and callback invocation
1614	cost, but overall scores in on the third place.	2560	cost, but overall scores in on the third place.
		2561
		2562	C<IO::Async> performs admirably well, about on par with C<Event>, even
		2563	when using its pure perl backend.
1615		2564
1616	C<Glib>'s memory usage is quite a bit higher, but it features a	2565	C<Glib>'s memory usage is quite a bit higher, but it features a
1617	faster callback invocation and overall ends up in the same class as	2566	faster callback invocation and overall ends up in the same class as
1618	C<Event>. However, Glib scales extremely badly, doubling the number of	2567	C<Event>. However, Glib scales extremely badly, doubling the number of
1619	watchers increases the processing time by more than a factor of four,	2568	watchers increases the processing time by more than a factor of four,
…		…
1654	(even when used without AnyEvent), but most event loops have acceptable	2603	(even when used without AnyEvent), but most event loops have acceptable
1655	performance with or without AnyEvent.	2604	performance with or without AnyEvent.
1656		2605
1657	=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
1658	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
1659	adds AnyEvent significant overhead.	2608	does AnyEvent add significant overhead.
1660		2609
1661	=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
1662	reasonable memory usage.	2611	reasonable memory usage.
1663		2612
1664	=back	2613	=back
…		…
1680	In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100	2629	In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100
1681	(1%) are active. This mirrors the activity of large servers with many	2630	(1%) are active. This mirrors the activity of large servers with many
1682	connections, most of which are idle at any one point in time.	2631	connections, most of which are idle at any one point in time.
1683		2632
1684	Source code for this benchmark is found as F<eg/bench2> in the AnyEvent	2633	Source code for this benchmark is found as F<eg/bench2> in the AnyEvent
1685	distribution.	2634	distribution. It uses the L<AE> interface, which makes a real difference
		2635	for the EV and Perl backends only.
1686		2636
1687	=head3 Explanation of the columns	2637	=head3 Explanation of the columns
1688		2638
1689	I<sockets> is the number of sockets, and twice the number of "servers" (as	2639	I<sockets> is the number of sockets, and twice the number of "servers" (as
1690	each server has a read and write socket end).	2640	each server has a read and write socket end).
…		…
1697	it to another server. This includes deleting the old timeout and creating	2647	it to another server. This includes deleting the old timeout and creating
1698	a new one that moves the timeout into the future.	2648	a new one that moves the timeout into the future.
1699		2649
1700	=head3 Results	2650	=head3 Results
1701		2651
1702	name sockets create request	2652	name sockets create request
1703	EV 20000 69.01 11.16	2653	EV 20000 62.66 7.99
1704	Perl 20000 73.32 35.87	2654	Perl 20000 68.32 32.64
1705	Event 20000 212.62 257.32	2655	IOAsync 20000 174.06 101.15 epoll
1706	Glib 20000 651.16 1896.30	2656	IOAsync 20000 174.67 610.84 poll
		2657	Event 20000 202.69 242.91
		2658	Glib 20000 557.01 1689.52
1707	POE 20000 349.67 12317.24 uses POE::Loop::Event	2659	POE 20000 341.54 12086.32 uses POE::Loop::Event
1708		2660
1709	=head3 Discussion	2661	=head3 Discussion
1710		2662
1711	This benchmark I<does> measure scalability and overall performance of the	2663	This benchmark I<does> measure scalability and overall performance of the
1712	particular event loop.	2664	particular event loop.
…		…
1714	EV is again fastest. Since it is using epoll on my system, the setup time	2666	EV is again fastest. Since it is using epoll on my system, the setup time
1715	is relatively high, though.	2667	is relatively high, though.
1716		2668
1717	Perl surprisingly comes second. It is much faster than the C-based event	2669	Perl surprisingly comes second. It is much faster than the C-based event
1718	loops Event and Glib.	2670	loops Event and Glib.
		2671
		2672	IO::Async performs very well when using its epoll backend, and still quite
		2673	good compared to Glib when using its pure perl backend.
1719		2674
1720	Event suffers from high setup time as well (look at its code and you will	2675	Event suffers from high setup time as well (look at its code and you will
1721	understand why). Callback invocation also has a high overhead compared to	2676	understand why). Callback invocation also has a high overhead compared to
1722	the C<< $_->() for .. >>-style loop that the Perl event loop uses. Event	2677	the C<< $_->() for .. >>-style loop that the Perl event loop uses. Event
1723	uses select or poll in basically all documented configurations.	2678	uses select or poll in basically all documented configurations.
…		…
1786	=item * C-based event loops perform very well with small number of	2741	=item * C-based event loops perform very well with small number of
1787	watchers, as the management overhead dominates.	2742	watchers, as the management overhead dominates.
1788		2743
1789	=back	2744	=back
1790		2745
		2746	=head2 THE IO::Lambda BENCHMARK
		2747
		2748	Recently I was told about the benchmark in the IO::Lambda manpage, which
		2749	could be misinterpreted to make AnyEvent look bad. In fact, the benchmark
		2750	simply compares IO::Lambda with POE, and IO::Lambda looks better (which
		2751	shouldn't come as a surprise to anybody). As such, the benchmark is
		2752	fine, and mostly shows that the AnyEvent backend from IO::Lambda isn't
		2753	very optimal. But how would AnyEvent compare when used without the extra
		2754	baggage? To explore this, I wrote the equivalent benchmark for AnyEvent.
		2755
		2756	The benchmark itself creates an echo-server, and then, for 500 times,
		2757	connects to the echo server, sends a line, waits for the reply, and then
		2758	creates the next connection. This is a rather bad benchmark, as it doesn't
		2759	test the efficiency of the framework or much non-blocking I/O, but it is a
		2760	benchmark nevertheless.
		2761
		2762	name runtime
		2763	Lambda/select 0.330 sec
		2764	+ optimized 0.122 sec
		2765	Lambda/AnyEvent 0.327 sec
		2766	+ optimized 0.138 sec
		2767	Raw sockets/select 0.077 sec
		2768	POE/select, components 0.662 sec
		2769	POE/select, raw sockets 0.226 sec
		2770	POE/select, optimized 0.404 sec
		2771
		2772	AnyEvent/select/nb 0.085 sec
		2773	AnyEvent/EV/nb 0.068 sec
		2774	+state machine 0.134 sec
		2775
		2776	The benchmark is also a bit unfair (my fault): the IO::Lambda/POE
		2777	benchmarks actually make blocking connects and use 100% blocking I/O,
		2778	defeating the purpose of an event-based solution. All of the newly
		2779	written AnyEvent benchmarks use 100% non-blocking connects (using
		2780	AnyEvent::Socket::tcp_connect and the asynchronous pure perl DNS
		2781	resolver), so AnyEvent is at a disadvantage here, as non-blocking connects
		2782	generally require a lot more bookkeeping and event handling than blocking
		2783	connects (which involve a single syscall only).
		2784
		2785	The last AnyEvent benchmark additionally uses L<AnyEvent::Handle>, which
		2786	offers similar expressive power as POE and IO::Lambda, using conventional
		2787	Perl syntax. This means that both the echo server and the client are 100%
		2788	non-blocking, further placing it at a disadvantage.
		2789
		2790	As you can see, the AnyEvent + EV combination even beats the
		2791	hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl
		2792	backend easily beats IO::Lambda and POE.
		2793
		2794	And even the 100% non-blocking version written using the high-level (and
		2795	slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda
		2796	higher level ("unoptimised") abstractions by a large margin, even though
		2797	it does all of DNS, tcp-connect and socket I/O in a non-blocking way.
		2798
		2799	The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and
		2800	F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are
		2801	part of the IO::Lambda distribution and were used without any changes.
		2802
1791		2803
1792	=head1 SIGNALS	2804	=head1 SIGNALS
1793		2805
1794	AnyEvent currently installs handlers for these signals:	2806	AnyEvent currently installs handlers for these signals:
1795		2807
…		…
1798	=item SIGCHLD	2810	=item SIGCHLD
1799		2811
1800	A handler for C<SIGCHLD> is installed by AnyEvent's child watcher	2812	A handler for C<SIGCHLD> is installed by AnyEvent's child watcher
1801	emulation for event loops that do not support them natively. Also, some	2813	emulation for event loops that do not support them natively. Also, some
1802	event loops install a similar handler.	2814	event loops install a similar handler.
		2815
		2816	Additionally, when AnyEvent is loaded and SIGCHLD is set to IGNORE, then
		2817	AnyEvent will reset it to default, to avoid losing child exit statuses.
1803		2818
1804	=item SIGPIPE	2819	=item SIGPIPE
1805		2820
1806	A no-op handler is installed for C<SIGPIPE> when C<$SIG{PIPE}> is C<undef>	2821	A no-op handler is installed for C<SIGPIPE> when C<$SIG{PIPE}> is C<undef>
1807	when AnyEvent gets loaded.	2822	when AnyEvent gets loaded.
…		…
1819		2834
1820	=back	2835	=back
1821		2836
1822	=cut	2837	=cut
1823		2838
		2839	undef $SIG{CHLD}
		2840	if $SIG{CHLD} eq 'IGNORE';
		2841
1824	$SIG{PIPE} = sub { }	2842	$SIG{PIPE} = sub { }
1825	unless defined $SIG{PIPE};	2843	unless defined $SIG{PIPE};
1826		2844
		2845	=head1 RECOMMENDED/OPTIONAL MODULES
		2846
		2847	One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and
		2848	its built-in modules) are required to use it.
		2849
		2850	That does not mean that AnyEvent won't take advantage of some additional
		2851	modules if they are installed.
		2852
		2853	This section explains which additional modules will be used, and how they
		2854	affect AnyEvent's operation.
		2855
		2856	=over 4
		2857
		2858	=item L<Async::Interrupt>
		2859
		2860	This slightly arcane module is used to implement fast signal handling: To
		2861	my knowledge, there is no way to do completely race-free and quick
		2862	signal handling in pure perl. To ensure that signals still get
		2863	delivered, AnyEvent will start an interval timer to wake up perl (and
		2864	catch the signals) with some delay (default is 10 seconds, look for
		2865	C<$AnyEvent::MAX_SIGNAL_LATENCY>).
		2866
		2867	If this module is available, then it will be used to implement signal
		2868	catching, which means that signals will not be delayed, and the event loop
		2869	will not be interrupted regularly, which is more efficient (and good for
		2870	battery life on laptops).
		2871
		2872	This affects not just the pure-perl event loop, but also other event loops
		2873	that have no signal handling on their own (e.g. Glib, Tk, Qt).
		2874
		2875	Some event loops (POE, Event, Event::Lib) offer signal watchers natively,
		2876	and either employ their own workarounds (POE) or use AnyEvent's workaround
		2877	(using C<$AnyEvent::MAX_SIGNAL_LATENCY>). Installing L<Async::Interrupt>
		2878	does nothing for those backends.
		2879
		2880	=item L<EV>
		2881
		2882	This module isn't really "optional", as it is simply one of the backend
		2883	event loops that AnyEvent can use. However, it is simply the best event
		2884	loop available in terms of features, speed and stability: It supports
		2885	the AnyEvent API optimally, implements all the watcher types in XS, does
		2886	automatic timer adjustments even when no monotonic clock is available,
		2887	can take avdantage of advanced kernel interfaces such as C<epoll> and
		2888	C<kqueue>, and is the fastest backend I<by far>. You can even embed
		2889	L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>).
		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
		2894	=item L<Guard>
		2895
		2896	The guard module, when used, will be used to implement
		2897	C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a
		2898	lot less memory), but otherwise doesn't affect guard operation much. It is
		2899	purely used for performance.
		2900
		2901	=item L<JSON> and L<JSON::XS>
		2902
		2903	One of these modules is required when you want to read or write JSON data
		2904	via L<AnyEvent::Handle>. L<JSON> is also written in pure-perl, but can take
		2905	advantage of the ultra-high-speed L<JSON::XS> module when it is installed.
		2906
		2907	=item L<Net::SSLeay>
		2908
		2909	Implementing TLS/SSL in Perl is certainly interesting, but not very
		2910	worthwhile: If this module is installed, then L<AnyEvent::Handle> (with
		2911	the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL.
		2912
		2913	=item L<Time::HiRes>
		2914
		2915	This module is part of perl since release 5.008. It will be used when the
		2916	chosen event library does not come with a timing source of its own. The
		2917	pure-perl event loop (L<AnyEvent::Loop>) will additionally load it to
		2918	try to use a monotonic clock for timing stability.
		2919
		2920	=back
		2921
1827		2922
1828	=head1 FORK	2923	=head1 FORK
1829		2924
1830	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
1831	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
1832	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).
1833		2937
1834	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
1835	watcher OR you must not use AnyEvent at all in the child.	2939	watcher OR you must not use AnyEvent at all in the child OR you must do
		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.
1836		2950
1837		2951
1838	=head1 SECURITY CONSIDERATIONS	2952	=head1 SECURITY CONSIDERATIONS
1839		2953
1840	AnyEvent can be forced to load any event model via	2954	AnyEvent can be forced to load any event model via
…		…
1852	use AnyEvent;	2966	use AnyEvent;
1853		2967
1854	Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can	2968	Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can
1855	be used to probe what backend is used and gain other information (which is	2969	be used to probe what backend is used and gain other information (which is
1856	probably even less useful to an attacker than PERL_ANYEVENT_MODEL), and	2970	probably even less useful to an attacker than PERL_ANYEVENT_MODEL), and
1857	$ENV{PERL_ANYEGENT_STRICT}.	2971	$ENV{PERL_ANYEVENT_STRICT}.
		2972
		2973	Note that AnyEvent will remove I<all> environment variables starting with
		2974	C<PERL_ANYEVENT_> from C<%ENV> when it is loaded while taint mode is
		2975	enabled.
1858		2976
1859		2977
1860	=head1 BUGS	2978	=head1 BUGS
1861		2979
1862	Perl 5.8 has numerous memleaks that sometimes hit this module and are hard	2980	Perl 5.8 has numerous memleaks that sometimes hit this module and are hard
1863	to work around. If you suffer from memleaks, first upgrade to Perl 5.10	2981	to work around. If you suffer from memleaks, first upgrade to Perl 5.10
1864	and check wether the leaks still show up. (Perl 5.10.0 has other annoying	2982	and check wether the leaks still show up. (Perl 5.10.0 has other annoying
1865	mamleaks, such as leaking on C<map> and C<grep> but it is usually not as	2983	memleaks, such as leaking on C<map> and C<grep> but it is usually not as
1866	pronounced).	2984	pronounced).
1867		2985
1868		2986
1869	=head1 SEE ALSO	2987	=head1 SEE ALSO
1870		2988
1871	Utility functions: L<AnyEvent::Util>.	2989	Tutorial/Introduction: L<AnyEvent::Intro>.
1872		2990
1873	Event modules: L<EV>, L<EV::Glib>, L<Glib::EV>, L<Event>, L<Glib::Event>,	2991	FAQ: L<AnyEvent::FAQ>.
1874	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>.
1875		3002
1876	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,	3003	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,
1877	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>,
1878	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,	3005	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,
		3006	L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>, L<Anyevent::Impl::Irssi>,
1879	L<AnyEvent::Impl::POE>.	3007	L<AnyEvent::Impl::FLTK>.
1880		3008
1881	Non-blocking file handles, sockets, TCP clients and	3009	Non-blocking handles, pipes, stream sockets, TCP clients and
1882	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>.	3010	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.
1883		3011
1884	Asynchronous DNS: L<AnyEvent::DNS>.	3012	Asynchronous DNS: L<AnyEvent::DNS>.
1885		3013
1886	Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>,	3014	Thread support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>.
1887		3015
1888	Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>, L<AnyEvent::DNS>.	3016	Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::IRC>,
		3017	L<AnyEvent::HTTP>.
1889		3018
1890		3019
1891	=head1 AUTHOR	3020	=head1 AUTHOR
1892		3021
1893	Marc Lehmann <schmorp@schmorp.de>	3022	Marc Lehmann <schmorp@schmorp.de>

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