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Revision 1.269 by root, Fri Jul 31 20:16:29 2009 UTC vs.
Revision 1.416 by root, Tue Dec 17 16:43:15 2013 UTC

1	=head1 NAME	1	=head1 NAME
2		2
3	AnyEvent - the DBI of event loop programming	3	AnyEvent - the DBI of event loop programming
4		4
5	EV, Event, Glib, Tk, Perl, Event::Lib, Irssi, rxvt-unicode, IO::Async, Qt	5	EV, Event, Glib, Tk, Perl, Event::Lib, Irssi, rxvt-unicode, IO::Async, Qt,
6	and POE are various supported event loops/environments.	6	FLTK and POE are various supported event loops/environments.
7		7
8	=head1 SYNOPSIS	8	=head1 SYNOPSIS
9		9
10	use AnyEvent;	10	use AnyEvent;
11		11
		12	# if you prefer function calls, look at the AE manpage for
		13	# an alternative API.
		14
12	# file descriptor readable	15	# file handle or descriptor readable
13	my $w = AnyEvent->io (fh => $fh, poll => "r", cb => sub { ... });	16	my $w = AnyEvent->io (fh => $fh, poll => "r", cb => sub { ... });
14		17
15	# one-shot or repeating timers	18	# one-shot or repeating timers
16	my $w = AnyEvent->timer (after => $seconds, cb => sub { ... });	19	my $w = AnyEvent->timer (after => $seconds, cb => sub { ... });
17	my $w = AnyEvent->timer (after => $seconds, interval => $seconds, cb => ...	20	my $w = AnyEvent->timer (after => $seconds, interval => $seconds, cb => ...);
18		21
19	print AnyEvent->now; # prints current event loop time	22	print AnyEvent->now; # prints current event loop time
20	print AnyEvent->time; # think Time::HiRes::time or simply CORE::time.	23	print AnyEvent->time; # think Time::HiRes::time or simply CORE::time.
21		24
22	# POSIX signal	25	# POSIX signal
…		…
43	in a tutorial or some gentle introduction, have a look at the	46	in a tutorial or some gentle introduction, have a look at the
44	L<AnyEvent::Intro> manpage.	47	L<AnyEvent::Intro> manpage.
45		48
46	=head1 SUPPORT	49	=head1 SUPPORT
47		50
		51	An FAQ document is available as L<AnyEvent::FAQ>.
		52
48	There is a mailinglist for discussing all things AnyEvent, and an IRC	53	There also is a mailinglist for discussing all things AnyEvent, and an IRC
49	channel, too.	54	channel, too.
50		55
51	See the AnyEvent project page at the B<Schmorpforge Ta-Sa Software	56	See the AnyEvent project page at the B<Schmorpforge Ta-Sa Software
52	Repository>, at L<http://anyevent.schmorp.de>, for more info.	57	Repository>, at L<http://anyevent.schmorp.de>, for more info.
53		58
…		…
73	module users into the same thing by forcing them to use the same event	78	module users into the same thing by forcing them to use the same event
74	model you use.	79	model you use.
75		80
76	For modules like POE or IO::Async (which is a total misnomer as it is	81	For modules like POE or IO::Async (which is a total misnomer as it is
77	actually doing all I/O I<synchronously>...), using them in your module is	82	actually doing all I/O I<synchronously>...), using them in your module is
78	like joining a cult: After you joined, you are dependent on them and you	83	like joining a cult: After you join, you are dependent on them and you
79	cannot use anything else, as they are simply incompatible to everything	84	cannot use anything else, as they are simply incompatible to everything
80	that isn't them. What's worse, all the potential users of your	85	that isn't them. What's worse, all the potential users of your
81	module are I<also> forced to use the same event loop you use.	86	module are I<also> forced to use the same event loop you use.
82		87
83	AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works	88	AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works
84	fine. AnyEvent + Tk works fine etc. etc. but none of these work together	89	fine. AnyEvent + Tk works fine etc. etc. but none of these work together
85	with the rest: POE + IO::Async? No go. Tk + Event? No go. Again: if	90	with the rest: POE + EV? No go. Tk + Event? No go. Again: if your module
86	your module uses one of those, every user of your module has to use it,	91	uses one of those, every user of your module has to use it, too. But if
87	too. But if your module uses AnyEvent, it works transparently with all	92	your module uses AnyEvent, it works transparently with all event models it
88	event models it supports (including stuff like IO::Async, as long as those	93	supports (including stuff like IO::Async, as long as those use one of the
89	use one of the supported event loops. It is trivial to add new event loops	94	supported event loops. It is easy to add new event loops to AnyEvent, too,
90	to AnyEvent, too, so it is future-proof).	95	so it is future-proof).
91		96
92	In addition to being free of having to use I<the one and only true event	97	In addition to being free of having to use I<the one and only true event
93	model>, AnyEvent also is free of bloat and policy: with POE or similar	98	model>, AnyEvent also is free of bloat and policy: with POE or similar
94	modules, you get an enormous amount of code and strict rules you have to	99	modules, you get an enormous amount of code and strict rules you have to
95	follow. AnyEvent, on the other hand, is lean and up to the point, by only	100	follow. AnyEvent, on the other hand, is lean and to the point, by only
96	offering the functionality that is necessary, in as thin as a wrapper as	101	offering the functionality that is necessary, in as thin as a wrapper as
97	technically possible.	102	technically possible.
98		103
99	Of course, AnyEvent comes with a big (and fully optional!) toolbox	104	Of course, AnyEvent comes with a big (and fully optional!) toolbox
100	of useful functionality, such as an asynchronous DNS resolver, 100%	105	of useful functionality, such as an asynchronous DNS resolver, 100%
…		…
106	useful) and you want to force your users to use the one and only event	111	useful) and you want to force your users to use the one and only event
107	model, you should I<not> use this module.	112	model, you should I<not> use this module.
108		113
109	=head1 DESCRIPTION	114	=head1 DESCRIPTION
110		115
111	L<AnyEvent> provides an identical interface to multiple event loops. This	116	L<AnyEvent> provides a uniform interface to various event loops. This
112	allows module authors to utilise an event loop without forcing module	117	allows module authors to use event loop functionality without forcing
113	users to use the same event loop (as only a single event loop can coexist	118	module users to use a specific event loop implementation (since more
114	peacefully at any one time).	119	than one event loop cannot coexist peacefully).
115		120
116	The interface itself is vaguely similar, but not identical to the L<Event>	121	The interface itself is vaguely similar, but not identical to the L<Event>
117	module.	122	module.
118		123
119	During the first call of any watcher-creation method, the module tries	124	During the first call of any watcher-creation method, the module tries
120	to detect the currently loaded event loop by probing whether one of the	125	to detect the currently loaded event loop by probing whether one of the
121	following modules is already loaded: L<EV>,	126	following modules is already loaded: L<EV>, L<AnyEvent::Loop>,
122	L<Event>, L<Glib>, L<AnyEvent::Impl::Perl>, L<Tk>, L<Event::Lib>, L<Qt>,	127	L<Event>, L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>. The first one
123	L<POE>. The first one found is used. If none are found, the module tries	128	found is used. If none are detected, the module tries to load the first
124	to load these modules (excluding Tk, Event::Lib, Qt and POE as the pure perl	129	four modules in the order given; but note that if L<EV> is not
125	adaptor should always succeed) in the order given. The first one that can	130	available, the pure-perl L<AnyEvent::Loop> should always work, so
126	be successfully loaded will be used. If, after this, still none could be	131	the other two are not normally tried.
127	found, AnyEvent will fall back to a pure-perl event loop, which is not
128	very efficient, but should work everywhere.
129		132
130	Because AnyEvent first checks for modules that are already loaded, loading	133	Because AnyEvent first checks for modules that are already loaded, loading
131	an event model explicitly before first using AnyEvent will likely make	134	an event model explicitly before first using AnyEvent will likely make
132	that model the default. For example:	135	that model the default. For example:
133		136
…		…
135	use AnyEvent;	138	use AnyEvent;
136		139
137	# .. AnyEvent will likely default to Tk	140	# .. AnyEvent will likely default to Tk
138		141
139	The I<likely> means that, if any module loads another event model and	142	The I<likely> means that, if any module loads another event model and
140	starts using it, all bets are off. Maybe you should tell their authors to	143	starts using it, all bets are off - this case should be very rare though,
141	use AnyEvent so their modules work together with others seamlessly...	144	as very few modules hardcode event loops without announcing this very
		145	loudly.
142		146
143	The pure-perl implementation of AnyEvent is called	147	The pure-perl implementation of AnyEvent is called C<AnyEvent::Loop>. Like
144	C<AnyEvent::Impl::Perl>. Like other event modules you can load it	148	other event modules you can load it explicitly and enjoy the high
145	explicitly and enjoy the high availability of that event loop :)	149	availability of that event loop :)
146		150
147	=head1 WATCHERS	151	=head1 WATCHERS
148		152
149	AnyEvent has the central concept of a I<watcher>, which is an object that	153	AnyEvent has the central concept of a I<watcher>, which is an object that
150	stores relevant data for each kind of event you are waiting for, such as	154	stores relevant data for each kind of event you are waiting for, such as
…		…
155	callback when the event occurs (of course, only when the event model	159	callback when the event occurs (of course, only when the event model
156	is in control).	160	is in control).
157		161
158	Note that B<callbacks must not permanently change global variables>	162	Note that B<callbacks must not permanently change global variables>
159	potentially in use by the event loop (such as C<$_> or C<$[>) and that B<<	163	potentially in use by the event loop (such as C<$_> or C<$[>) and that B<<
160	callbacks must not C<die> >>. The former is good programming practise in	164	callbacks must not C<die> >>. The former is good programming practice in
161	Perl and the latter stems from the fact that exception handling differs	165	Perl and the latter stems from the fact that exception handling differs
162	widely between event loops.	166	widely between event loops.
163		167
164	To disable the watcher you have to destroy it (e.g. by setting the	168	To disable a watcher you have to destroy it (e.g. by setting the
165	variable you store it in to C<undef> or otherwise deleting all references	169	variable you store it in to C<undef> or otherwise deleting all references
166	to it).	170	to it).
167		171
168	All watchers are created by calling a method on the C<AnyEvent> class.	172	All watchers are created by calling a method on the C<AnyEvent> class.
169		173
170	Many watchers either are used with "recursion" (repeating timers for	174	Many watchers either are used with "recursion" (repeating timers for
171	example), or need to refer to their watcher object in other ways.	175	example), or need to refer to their watcher object in other ways.
172		176
173	An any way to achieve that is this pattern:	177	One way to achieve that is this pattern:
174		178
175	my $w; $w = AnyEvent->type (arg => value ..., cb => sub {	179	my $w; $w = AnyEvent->type (arg => value ..., cb => sub {
176	# you can use $w here, for example to undef it	180	# you can use $w here, for example to undef it
177	undef $w;	181	undef $w;
178	});	182	});
…		…
210		214
211	The I/O watcher might use the underlying file descriptor or a copy of it.	215	The I/O watcher might use the underlying file descriptor or a copy of it.
212	You must not close a file handle as long as any watcher is active on the	216	You must not close a file handle as long as any watcher is active on the
213	underlying file descriptor.	217	underlying file descriptor.
214		218
215	Some event loops issue spurious readyness notifications, so you should	219	Some event loops issue spurious readiness notifications, so you should
216	always use non-blocking calls when reading/writing from/to your file	220	always use non-blocking calls when reading/writing from/to your file
217	handles.	221	handles.
218		222
219	Example: wait for readability of STDIN, then read a line and disable the	223	Example: wait for readability of STDIN, then read a line and disable the
220	watcher.	224	watcher.
…		…
244		248
245	Although the callback might get passed parameters, their value and	249	Although the callback might get passed parameters, their value and
246	presence is undefined and you cannot rely on them. Portable AnyEvent	250	presence is undefined and you cannot rely on them. Portable AnyEvent
247	callbacks cannot use arguments passed to time watcher callbacks.	251	callbacks cannot use arguments passed to time watcher callbacks.
248		252
249	The callback will normally be invoked once only. If you specify another	253	The callback will normally be invoked only once. If you specify another
250	parameter, C<interval>, as a strictly positive number (> 0), then the	254	parameter, C<interval>, as a strictly positive number (> 0), then the
251	callback will be invoked regularly at that interval (in fractional	255	callback will be invoked regularly at that interval (in fractional
252	seconds) after the first invocation. If C<interval> is specified with a	256	seconds) after the first invocation. If C<interval> is specified with a
253	false value, then it is treated as if it were missing.	257	false value, then it is treated as if it were not specified at all.
254		258
255	The callback will be rescheduled before invoking the callback, but no	259	The callback will be rescheduled before invoking the callback, but no
256	attempt is done to avoid timer drift in most backends, so the interval is	260	attempt is made to avoid timer drift in most backends, so the interval is
257	only approximate.	261	only approximate.
258		262
259	Example: fire an event after 7.7 seconds.	263	Example: fire an event after 7.7 seconds.
260		264
261	my $w = AnyEvent->timer (after => 7.7, cb => sub {	265	my $w = AnyEvent->timer (after => 7.7, cb => sub {
…		…
267		271
268	Example 2: fire an event after 0.5 seconds, then roughly every second.	272	Example 2: fire an event after 0.5 seconds, then roughly every second.
269		273
270	my $w = AnyEvent->timer (after => 0.5, interval => 1, cb => sub {	274	my $w = AnyEvent->timer (after => 0.5, interval => 1, cb => sub {
271	warn "timeout\n";	275	warn "timeout\n";
272	};	276	});
273		277
274	=head3 TIMING ISSUES	278	=head3 TIMING ISSUES
275		279
276	There are two ways to handle timers: based on real time (relative, "fire	280	There are two ways to handle timers: based on real time (relative, "fire
277	in 10 seconds") and based on wallclock time (absolute, "fire at 12	281	in 10 seconds") and based on wallclock time (absolute, "fire at 12
…		…
279		283
280	While most event loops expect timers to specified in a relative way, they	284	While most event loops expect timers to specified in a relative way, they
281	use absolute time internally. This makes a difference when your clock	285	use absolute time internally. This makes a difference when your clock
282	"jumps", for example, when ntp decides to set your clock backwards from	286	"jumps", for example, when ntp decides to set your clock backwards from
283	the wrong date of 2014-01-01 to 2008-01-01, a watcher that is supposed to	287	the wrong date of 2014-01-01 to 2008-01-01, a watcher that is supposed to
284	fire "after" a second might actually take six years to finally fire.	288	fire "after a second" might actually take six years to finally fire.
285		289
286	AnyEvent cannot compensate for this. The only event loop that is conscious	290	AnyEvent cannot compensate for this. The only event loop that is conscious
287	about these issues is L<EV>, which offers both relative (ev_timer, based	291	of these issues is L<EV>, which offers both relative (ev_timer, based
288	on true relative time) and absolute (ev_periodic, based on wallclock time)	292	on true relative time) and absolute (ev_periodic, based on wallclock time)
289	timers.	293	timers.
290		294
291	AnyEvent always prefers relative timers, if available, matching the	295	AnyEvent always prefers relative timers, if available, matching the
292	AnyEvent API.	296	AnyEvent API.
…		…
314	I<In almost all cases (in all cases if you don't care), this is the	318	I<In almost all cases (in all cases if you don't care), this is the
315	function to call when you want to know the current time.>	319	function to call when you want to know the current time.>
316		320
317	This function is also often faster then C<< AnyEvent->time >>, and	321	This function is also often faster then C<< AnyEvent->time >>, and
318	thus the preferred method if you want some timestamp (for example,	322	thus the preferred method if you want some timestamp (for example,
319	L<AnyEvent::Handle> uses this to update it's activity timeouts).	323	L<AnyEvent::Handle> uses this to update its activity timeouts).
320		324
321	The rest of this section is only of relevance if you try to be very exact	325	The rest of this section is only of relevance if you try to be very exact
322	with your timing, you can skip it without bad conscience.	326	with your timing; you can skip it without a bad conscience.
323		327
324	For a practical example of when these times differ, consider L<Event::Lib>	328	For a practical example of when these times differ, consider L<Event::Lib>
325	and L<EV> and the following set-up:	329	and L<EV> and the following set-up:
326		330
327	The event loop is running and has just invoked one of your callback at	331	The event loop is running and has just invoked one of your callbacks at
328	time=500 (assume no other callbacks delay processing). In your callback,	332	time=500 (assume no other callbacks delay processing). In your callback,
329	you wait a second by executing C<sleep 1> (blocking the process for a	333	you wait a second by executing C<sleep 1> (blocking the process for a
330	second) and then (at time=501) you create a relative timer that fires	334	second) and then (at time=501) you create a relative timer that fires
331	after three seconds.	335	after three seconds.
332		336
…		…
352	difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into	356	difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into
353	account.	357	account.
354		358
355	=item AnyEvent->now_update	359	=item AnyEvent->now_update
356		360
357	Some event loops (such as L<EV> or L<AnyEvent::Impl::Perl>) cache	361	Some event loops (such as L<EV> or L<AnyEvent::Loop>) cache the current
358	the current time for each loop iteration (see the discussion of L<<	362	time for each loop iteration (see the discussion of L<< AnyEvent->now >>,
359	AnyEvent->now >>, above).	363	above).
360		364
361	When a callback runs for a long time (or when the process sleeps), then	365	When a callback runs for a long time (or when the process sleeps), then
362	this "current" time will differ substantially from the real time, which	366	this "current" time will differ substantially from the real time, which
363	might affect timers and time-outs.	367	might affect timers and time-outs.
364		368
365	When this is the case, you can call this method, which will update the	369	When this is the case, you can call this method, which will update the
366	event loop's idea of "current time".	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).
367		378
368	Note that updating the time I<might> cause some events to be handled.	379	Note that updating the time I<might> cause some events to be handled.
369		380
370	=back	381	=back
371		382
…		…
396		407
397	Example: exit on SIGINT	408	Example: exit on SIGINT
398		409
399	my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });	410	my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });
400		411
		412	=head3 Restart Behaviour
		413
		414	While restart behaviour is up to the event loop implementation, most will
		415	not restart syscalls (that includes L<Async::Interrupt> and AnyEvent's
		416	pure perl implementation).
		417
		418	=head3 Safe/Unsafe Signals
		419
		420	Perl signals can be either "safe" (synchronous to opcode handling)
		421	or "unsafe" (asynchronous) - the former might delay signal delivery
		422	indefinitely, the latter might corrupt your memory.
		423
		424	AnyEvent signal handlers are, in addition, synchronous to the event loop,
		425	i.e. they will not interrupt your running perl program but will only be
		426	called as part of the normal event handling (just like timer, I/O etc.
		427	callbacks, too).
		428
401	=head3 Signal Races, Delays and Workarounds	429	=head3 Signal Races, Delays and Workarounds
402		430
403	Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support attaching	431	Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support
404	callbacks to signals in a generic way, which is a pity, as you cannot	432	attaching callbacks to signals in a generic way, which is a pity,
405	do race-free signal handling in perl, requiring C libraries for	433	as you cannot do race-free signal handling in perl, requiring
406	this. AnyEvent will try to do it's best, which means in some cases,	434	C libraries for this. AnyEvent will try to do its best, which
407	signals will be delayed. The maximum time a signal might be delayed is	435	means in some cases, signals will be delayed. The maximum time
408	specified in C<$AnyEvent::MAX_SIGNAL_LATENCY> (default: 10 seconds). This	436	a signal might be delayed is 10 seconds by default, but can
409	variable can be changed only before the first signal watcher is created,	437	be overriden via C<$ENV{PERL_ANYEVENT_MAX_SIGNAL_LATENCY}> or
410	and should be left alone otherwise. This variable determines how often	438	C<$AnyEvent::MAX_SIGNAL_LATENCY> - see the L<ENVIRONMENT VARIABLES>
411	AnyEvent polls for signals (in case a wake-up was missed). Higher values	439	section for details.
412	will cause fewer spurious wake-ups, which is better for power and CPU
413	saving.
414		440
415	All these problems can be avoided by installing the optional	441	All these problems can be avoided by installing the optional
416	L<Async::Interrupt> module, which works with most event loops. It will not	442	L<Async::Interrupt> module, which works with most event loops. It will not
417	work with inherently broken event loops such as L<Event> or L<Event::Lib>	443	work with inherently broken event loops such as L<Event> or L<Event::Lib>
418	(and not with L<POE> currently, as POE does it's own workaround with	444	(and not with L<POE> currently). For those, you just have to suffer the
419	one-second latency). For those, you just have to suffer the delays.	445	delays.
420		446
421	=head2 CHILD PROCESS WATCHERS	447	=head2 CHILD PROCESS WATCHERS
422		448
423	$w = AnyEvent->child (pid => <process id>, cb => <callback>);	449	$w = AnyEvent->child (pid => <process id>, cb => <callback>);
424		450
425	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.
426		452
427	The child process is specified by the C<pid> argument (one some backends,	453	The child process is specified by the C<pid> argument (on some backends,
428	using C<0> watches for any child process exit, on others this will	454	using C<0> watches for any child process exit, on others this will
429	croak). The watcher will be triggered only when the child process has	455	croak). The watcher will be triggered only when the child process has
430	finished and an exit status is available, not on any trace events	456	finished and an exit status is available, not on any trace events
431	(stopped/continued).	457	(stopped/continued).
432		458
…		…
454	thing in an AnyEvent program, you I<have> to create at least one	480	thing in an AnyEvent program, you I<have> to create at least one
455	watcher before you C<fork> the child (alternatively, you can call	481	watcher before you C<fork> the child (alternatively, you can call
456	C<AnyEvent::detect>).	482	C<AnyEvent::detect>).
457		483
458	As most event loops do not support waiting for child events, they will be	484	As most event loops do not support waiting for child events, they will be
459	emulated by AnyEvent in most cases, in which the latency and race problems	485	emulated by AnyEvent in most cases, in which case the latency and race
460	mentioned in the description of signal watchers apply.	486	problems mentioned in the description of signal watchers apply.
461		487
462	Example: fork a process and wait for it	488	Example: fork a process and wait for it
463		489
464	my $done = AnyEvent->condvar;	490	my $done = AnyEvent->condvar;
465		491
		492	# this forks and immediately calls exit in the child. this
		493	# normally has all sorts of bad consequences for your parent,
		494	# so take this as an example only. always fork and exec,
		495	# or call POSIX::_exit, in real code.
466	my $pid = fork or exit 5;	496	my $pid = fork or exit 5;
467		497
468	my $w = AnyEvent->child (	498	my $w = AnyEvent->child (
469	pid => $pid,	499	pid => $pid,
470	cb => sub {	500	cb => sub {
…		…
479		509
480	=head2 IDLE WATCHERS	510	=head2 IDLE WATCHERS
481		511
482	$w = AnyEvent->idle (cb => <callback>);	512	$w = AnyEvent->idle (cb => <callback>);
483		513
484	Sometimes there is a need to do something, but it is not so important	514	This will repeatedly invoke the callback after the process becomes idle,
485	to do it instantly, but only when there is nothing better to do. This	515	until either the watcher is destroyed or new events have been detected.
486	"nothing better to do" is usually defined to be "no other events need
487	attention by the event loop".
488		516
489	Idle watchers ideally get invoked when the event loop has nothing	517	Idle watchers are useful when there is a need to do something, but it
490	better to do, just before it would block the process to wait for new	518	is not so important (or wise) to do it instantly. The callback will be
491	events. Instead of blocking, the idle watcher is invoked.	519	invoked only when there is "nothing better to do", which is usually
		520	defined as "all outstanding events have been handled and no new events
		521	have been detected". That means that idle watchers ideally get invoked
		522	when the event loop has just polled for new events but none have been
		523	detected. Instead of blocking to wait for more events, the idle watchers
		524	will be invoked.
492		525
493	Most event loops unfortunately do not really support idle watchers (only	526	Unfortunately, most event loops do not really support idle watchers (only
494	EV, Event and Glib do it in a usable fashion) - for the rest, AnyEvent	527	EV, Event and Glib do it in a usable fashion) - for the rest, AnyEvent
495	will simply call the callback "from time to time".	528	will simply call the callback "from time to time".
496		529
497	Example: read lines from STDIN, but only process them when the	530	Example: read lines from STDIN, but only process them when the
498	program is otherwise idle:	531	program is otherwise idle:
…		…
526	will actively watch for new events and call your callbacks.	559	will actively watch for new events and call your callbacks.
527		560
528	AnyEvent is slightly different: it expects somebody else to run the event	561	AnyEvent is slightly different: it expects somebody else to run the event
529	loop and will only block when necessary (usually when told by the user).	562	loop and will only block when necessary (usually when told by the user).
530		563
531	The instrument to do that is called a "condition variable", so called	564	The tool to do that is called a "condition variable", so called because
532	because they represent a condition that must become true.	565	they represent a condition that must become true.
533		566
534	Now is probably a good time to look at the examples further below.	567	Now is probably a good time to look at the examples further below.
535		568
536	Condition variables can be created by calling the C<< AnyEvent->condvar	569	Condition variables can be created by calling the C<< AnyEvent->condvar
537	>> method, usually without arguments. The only argument pair allowed is	570	>> method, usually without arguments. The only argument pair allowed is
…		…
542	After creation, the condition variable is "false" until it becomes "true"	575	After creation, the condition variable is "false" until it becomes "true"
543	by calling the C<send> method (or calling the condition variable as if it	576	by calling the C<send> method (or calling the condition variable as if it
544	were a callback, read about the caveats in the description for the C<<	577	were a callback, read about the caveats in the description for the C<<
545	->send >> method).	578	->send >> method).
546		579
547	Condition variables are similar to callbacks, except that you can	580	Since condition variables are the most complex part of the AnyEvent API, here are
548	optionally wait for them. They can also be called merge points - points	581	some different mental models of what they are - pick the ones you can connect to:
549	in time where multiple outstanding events have been processed. And yet	582
550	another way to call them is transactions - each condition variable can be	583	=over 4
551	used to represent a transaction, which finishes at some point and delivers	584
552	a result. And yet some people know them as "futures" - a promise to	585	=item * Condition variables are like callbacks - you can call them (and pass them instead
553	compute/deliver something that you can wait for.	586	of callbacks). Unlike callbacks however, you can also wait for them to be called.
		587
		588	=item * Condition variables are signals - one side can emit or send them,
		589	the other side can wait for them, or install a handler that is called when
		590	the signal fires.
		591
		592	=item * Condition variables are like "Merge Points" - points in your program
		593	where you merge multiple independent results/control flows into one.
		594
		595	=item * Condition variables represent a transaction - functions that start
		596	some kind of transaction can return them, leaving the caller the choice
		597	between waiting in a blocking fashion, or setting a callback.
		598
		599	=item * Condition variables represent future values, or promises to deliver
		600	some result, long before the result is available.
		601
		602	=back
554		603
555	Condition variables are very useful to signal that something has finished,	604	Condition variables are very useful to signal that something has finished,
556	for example, if you write a module that does asynchronous http requests,	605	for example, if you write a module that does asynchronous http requests,
557	then a condition variable would be the ideal candidate to signal the	606	then a condition variable would be the ideal candidate to signal the
558	availability of results. The user can either act when the callback is	607	availability of results. The user can either act when the callback is
…		…
571		620
572	Condition variables are represented by hash refs in perl, and the keys	621	Condition variables are represented by hash refs in perl, and the keys
573	used by AnyEvent itself are all named C<_ae_XXX> to make subclassing	622	used by AnyEvent itself are all named C<_ae_XXX> to make subclassing
574	easy (it is often useful to build your own transaction class on top of	623	easy (it is often useful to build your own transaction class on top of
575	AnyEvent). To subclass, use C<AnyEvent::CondVar> as base class and call	624	AnyEvent). To subclass, use C<AnyEvent::CondVar> as base class and call
576	it's C<new> method in your own C<new> method.	625	its C<new> method in your own C<new> method.
577		626
578	There are two "sides" to a condition variable - the "producer side" which	627	There are two "sides" to a condition variable - the "producer side" which
579	eventually calls C<< -> send >>, and the "consumer side", which waits	628	eventually calls C<< -> send >>, and the "consumer side", which waits
580	for the send to occur.	629	for the send to occur.
581		630
582	Example: wait for a timer.	631	Example: wait for a timer.
583		632
584	# wait till the result is ready	633	# condition: "wait till the timer is fired"
585	my $result_ready = AnyEvent->condvar;	634	my $timer_fired = AnyEvent->condvar;
586		635
587	# do something such as adding a timer	636	# create the timer - we could wait for, say
588	# or socket watcher the calls $result_ready->send	637	# a handle becomign ready, or even an
589	# when the "result" is ready.	638	# AnyEvent::HTTP request to finish, but
590	# in this case, we simply use a timer:	639	# in this case, we simply use a timer:
591	my $w = AnyEvent->timer (	640	my $w = AnyEvent->timer (
592	after => 1,	641	after => 1,
593	cb => sub { $result_ready->send },	642	cb => sub { $timer_fired->send },
594	);	643	);
595		644
596	# this "blocks" (while handling events) till the callback	645	# this "blocks" (while handling events) till the callback
597	# calls -<send	646	# calls ->send
598	$result_ready->recv;	647	$timer_fired->recv;
599		648
600	Example: wait for a timer, but take advantage of the fact that condition	649	Example: wait for a timer, but take advantage of the fact that condition
601	variables are also callable directly.	650	variables are also callable directly.
602		651
603	my $done = AnyEvent->condvar;	652	my $done = AnyEvent->condvar;
…		…
646	they were a code reference). Calling them directly is the same as calling	695	they were a code reference). Calling them directly is the same as calling
647	C<send>.	696	C<send>.
648		697
649	=item $cv->croak ($error)	698	=item $cv->croak ($error)
650		699
651	Similar to send, but causes all call's to C<< ->recv >> to invoke	700	Similar to send, but causes all calls to C<< ->recv >> to invoke
652	C<Carp::croak> with the given error message/object/scalar.	701	C<Carp::croak> with the given error message/object/scalar.
653		702
654	This can be used to signal any errors to the condition variable	703	This can be used to signal any errors to the condition variable
655	user/consumer. Doing it this way instead of calling C<croak> directly	704	user/consumer. Doing it this way instead of calling C<croak> directly
656	delays the error detetcion, but has the overwhelmign advantage that it	705	delays the error detection, but has the overwhelming advantage that it
657	diagnoses the error at the place where the result is expected, and not	706	diagnoses the error at the place where the result is expected, and not
658	deep in some event clalback without connection to the actual code causing	707	deep in some event callback with no connection to the actual code causing
659	the problem.	708	the problem.
660		709
661	=item $cv->begin ([group callback])	710	=item $cv->begin ([group callback])
662		711
663	=item $cv->end	712	=item $cv->end
…		…
666	one. For example, a function that pings many hosts in parallel might want	715	one. For example, a function that pings many hosts in parallel might want
667	to use a condition variable for the whole process.	716	to use a condition variable for the whole process.
668		717
669	Every call to C<< ->begin >> will increment a counter, and every call to	718	Every call to C<< ->begin >> will increment a counter, and every call to
670	C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end	719	C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end
671	>>, the (last) callback passed to C<begin> will be executed. That callback	720	>>, the (last) callback passed to C<begin> will be executed, passing the
672	is I<supposed> to call C<< ->send >>, but that is not required. If no	721	condvar as first argument. That callback is I<supposed> to call C<< ->send
673	callback was set, C<send> will be called without any arguments.	722	>>, but that is not required. If no group callback was set, C<send> will
		723	be called without any arguments.
674		724
675	You can think of C<< $cv->send >> giving you an OR condition (one call	725	You can think of C<< $cv->send >> giving you an OR condition (one call
676	sends), while C<< $cv->begin >> and C<< $cv->end >> giving you an AND	726	sends), while C<< $cv->begin >> and C<< $cv->end >> giving you an AND
677	condition (all C<begin> calls must be C<end>'ed before the condvar sends).	727	condition (all C<begin> calls must be C<end>'ed before the condvar sends).
678		728
…		…
699	This works because for every event source (EOF on file handle), there is	749	This works because for every event source (EOF on file handle), there is
700	one call to C<begin>, so the condvar waits for all calls to C<end> before	750	one call to C<begin>, so the condvar waits for all calls to C<end> before
701	sending.	751	sending.
702		752
703	The ping example mentioned above is slightly more complicated, as the	753	The ping example mentioned above is slightly more complicated, as the
704	there are results to be passwd back, and the number of tasks that are	754	there are results to be passed back, and the number of tasks that are
705	begung can potentially be zero:	755	begun can potentially be zero:
706		756
707	my $cv = AnyEvent->condvar;	757	my $cv = AnyEvent->condvar;
708		758
709	my %result;	759	my %result;
710	$cv->begin (sub { $cv->send (\%result) });	760	$cv->begin (sub { shift->send (\%result) });
711		761
712	for my $host (@list_of_hosts) {	762	for my $host (@list_of_hosts) {
713	$cv->begin;	763	$cv->begin;
714	ping_host_then_call_callback $host, sub {	764	ping_host_then_call_callback $host, sub {
715	$result{$host} = ...;	765	$result{$host} = ...;
…		…
717	};	767	};
718	}	768	}
719		769
720	$cv->end;	770	$cv->end;
721		771
		772	...
		773
		774	my $results = $cv->recv;
		775
722	This code fragment supposedly pings a number of hosts and calls	776	This code fragment supposedly pings a number of hosts and calls
723	C<send> after results for all then have have been gathered - in any	777	C<send> after results for all then have have been gathered - in any
724	order. To achieve this, the code issues a call to C<begin> when it starts	778	order. To achieve this, the code issues a call to C<begin> when it starts
725	each ping request and calls C<end> when it has received some result for	779	each ping request and calls C<end> when it has received some result for
726	it. Since C<begin> and C<end> only maintain a counter, the order in which	780	it. Since C<begin> and C<end> only maintain a counter, the order in which
…		…
731	to be called once the counter reaches C<0>, and second, it ensures that	785	to be called once the counter reaches C<0>, and second, it ensures that
732	C<send> is called even when C<no> hosts are being pinged (the loop	786	C<send> is called even when C<no> hosts are being pinged (the loop
733	doesn't execute once).	787	doesn't execute once).
734		788
735	This is the general pattern when you "fan out" into multiple (but	789	This is the general pattern when you "fan out" into multiple (but
736	potentially none) subrequests: use an outer C<begin>/C<end> pair to set	790	potentially zero) subrequests: use an outer C<begin>/C<end> pair to set
737	the callback and ensure C<end> is called at least once, and then, for each	791	the callback and ensure C<end> is called at least once, and then, for each
738	subrequest you start, call C<begin> and for each subrequest you finish,	792	subrequest you start, call C<begin> and for each subrequest you finish,
739	call C<end>.	793	call C<end>.
740		794
741	=back	795	=back
…		…
748	=over 4	802	=over 4
749		803
750	=item $cv->recv	804	=item $cv->recv
751		805
752	Wait (blocking if necessary) until the C<< ->send >> or C<< ->croak	806	Wait (blocking if necessary) until the C<< ->send >> or C<< ->croak
753	>> methods have been called on c<$cv>, while servicing other watchers	807	>> methods have been called on C<$cv>, while servicing other watchers
754	normally.	808	normally.
755		809
756	You can only wait once on a condition - additional calls are valid but	810	You can only wait once on a condition - additional calls are valid but
757	will return immediately.	811	will return immediately.
758		812
…		…
761		815
762	In list context, all parameters passed to C<send> will be returned,	816	In list context, all parameters passed to C<send> will be returned,
763	in scalar context only the first one will be returned.	817	in scalar context only the first one will be returned.
764		818
765	Note that doing a blocking wait in a callback is not supported by any	819	Note that doing a blocking wait in a callback is not supported by any
766	event loop, that is, recursive invocation of a blocking C<< ->recv	820	event loop, that is, recursive invocation of a blocking C<< ->recv >> is
767	>> is not allowed, and the C<recv> call will C<croak> if such a	821	not allowed and the C<recv> call will C<croak> if such a condition is
768	condition is detected. This condition can be slightly loosened by using	822	detected. This requirement can be dropped by relying on L<Coro::AnyEvent>
769	L<Coro::AnyEvent>, which allows you to do a blocking C<< ->recv >> from	823	, which allows you to do a blocking C<< ->recv >> from any thread
770	any thread that doesn't run the event loop itself.	824	that doesn't run the event loop itself. L<Coro::AnyEvent> is loaded
		825	automatically when L<Coro> is used with L<AnyEvent>, so code does not need
		826	to do anything special to take advantage of that: any code that would
		827	normally block your program because it calls C<recv>, be executed in an
		828	C<async> thread instead without blocking other threads.
771		829
772	Not all event models support a blocking wait - some die in that case	830	Not all event models support a blocking wait - some die in that case
773	(programs might want to do that to stay interactive), so I<if you are	831	(programs might want to do that to stay interactive), so I<if you are
774	using this from a module, never require a blocking wait>. Instead, let the	832	using this from a module, never require a blocking wait>. Instead, let the
775	caller decide whether the call will block or not (for example, by coupling	833	caller decide whether the call will block or not (for example, by coupling
776	condition variables with some kind of request results and supporting	834	condition variables with some kind of request results and supporting
777	callbacks so the caller knows that getting the result will not block,	835	callbacks so the caller knows that getting the result will not block,
778	while still supporting blocking waits if the caller so desires).	836	while still supporting blocking waits if the caller so desires).
779		837
780	You can ensure that C<< -recv >> never blocks by setting a callback and	838	You can ensure that C<< ->recv >> never blocks by setting a callback and
781	only calling C<< ->recv >> from within that callback (or at a later	839	only calling C<< ->recv >> from within that callback (or at a later
782	time). This will work even when the event loop does not support blocking	840	time). This will work even when the event loop does not support blocking
783	waits otherwise.	841	waits otherwise.
784		842
785	=item $bool = $cv->ready	843	=item $bool = $cv->ready
…		…
790	=item $cb = $cv->cb ($cb->($cv))	848	=item $cb = $cv->cb ($cb->($cv))
791		849
792	This is a mutator function that returns the callback set and optionally	850	This is a mutator function that returns the callback set and optionally
793	replaces it before doing so.	851	replaces it before doing so.
794		852
795	The callback will be called when the condition becomes (or already was)	853	The callback will be called when the condition becomes "true", i.e. when
796	"true", i.e. when C<send> or C<croak> are called (or were called), with	854	C<send> or C<croak> are called, with the only argument being the
797	the only argument being the condition variable itself. Calling C<recv>	855	condition variable itself. If the condition is already true, the
		856	callback is called immediately when it is set. Calling C<recv> inside
798	inside the callback or at any later time is guaranteed not to block.	857	the callback or at any later time is guaranteed not to block.
799		858
800	=back	859	=back
801		860
802	=head1 SUPPORTED EVENT LOOPS/BACKENDS	861	=head1 SUPPORTED EVENT LOOPS/BACKENDS
803		862
…		…
806	=over 4	865	=over 4
807		866
808	=item Backends that are autoprobed when no other event loop can be found.	867	=item Backends that are autoprobed when no other event loop can be found.
809		868
810	EV is the preferred backend when no other event loop seems to be in	869	EV is the preferred backend when no other event loop seems to be in
811	use. If EV is not installed, then AnyEvent will try Event, and, failing	870	use. If EV is not installed, then AnyEvent will fall back to its own
812	that, will fall back to its own pure-perl implementation, which is	871	pure-perl implementation, which is available everywhere as it comes with
813	available everywhere as it comes with AnyEvent itself.	872	AnyEvent itself.
814		873
815	AnyEvent::Impl::EV based on EV (interface to libev, best choice).	874	AnyEvent::Impl::EV based on EV (interface to libev, best choice).
816	AnyEvent::Impl::Event based on Event, very stable, few glitches.
817	AnyEvent::Impl::Perl pure-perl implementation, fast and portable.	875	AnyEvent::Impl::Perl pure-perl AnyEvent::Loop, fast and portable.
818		876
819	=item Backends that are transparently being picked up when they are used.	877	=item Backends that are transparently being picked up when they are used.
820		878
821	These will be used when they are currently loaded when the first watcher	879	These will be used if they are already loaded when the first watcher
822	is created, in which case it is assumed that the application is using	880	is created, in which case it is assumed that the application is using
823	them. This means that AnyEvent will automatically pick the right backend	881	them. This means that AnyEvent will automatically pick the right backend
824	when the main program loads an event module before anything starts to	882	when the main program loads an event module before anything starts to
825	create watchers. Nothing special needs to be done by the main program.	883	create watchers. Nothing special needs to be done by the main program.
826		884
		885	AnyEvent::Impl::Event based on Event, very stable, few glitches.
827	AnyEvent::Impl::Glib based on Glib, slow but very stable.	886	AnyEvent::Impl::Glib based on Glib, slow but very stable.
828	AnyEvent::Impl::Tk based on Tk, very broken.	887	AnyEvent::Impl::Tk based on Tk, very broken.
829	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.	888	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
830	AnyEvent::Impl::POE based on POE, very slow, some limitations.	889	AnyEvent::Impl::POE based on POE, very slow, some limitations.
831	AnyEvent::Impl::Irssi used when running within irssi.	890	AnyEvent::Impl::Irssi used when running within irssi.
		891	AnyEvent::Impl::IOAsync based on IO::Async.
		892	AnyEvent::Impl::Cocoa based on Cocoa::EventLoop.
		893	AnyEvent::Impl::FLTK based on FLTK (fltk 2 binding).
832		894
833	=item Backends with special needs.	895	=item Backends with special needs.
834		896
835	Qt requires the Qt::Application to be instantiated first, but will	897	Qt requires the Qt::Application to be instantiated first, but will
836	otherwise be picked up automatically. As long as the main program	898	otherwise be picked up automatically. As long as the main program
837	instantiates the application before any AnyEvent watchers are created,	899	instantiates the application before any AnyEvent watchers are created,
838	everything should just work.	900	everything should just work.
839		901
840	AnyEvent::Impl::Qt based on Qt.	902	AnyEvent::Impl::Qt based on Qt.
841		903
842	Support for IO::Async can only be partial, as it is too broken and
843	architecturally limited to even support the AnyEvent API. It also
844	is the only event loop that needs the loop to be set explicitly, so
845	it can only be used by a main program knowing about AnyEvent. See
846	L<AnyEvent::Impl::Async> for the gory details.
847
848	AnyEvent::Impl::IOAsync based on IO::Async, cannot be autoprobed.
849
850	=item Event loops that are indirectly supported via other backends.	904	=item Event loops that are indirectly supported via other backends.
851		905
852	Some event loops can be supported via other modules:	906	Some event loops can be supported via other modules:
853		907
854	There is no direct support for WxWidgets (L<Wx>) or L<Prima>.	908	There is no direct support for WxWidgets (L<Wx>) or L<Prima>.
…		…
879	Contains C<undef> until the first watcher is being created, before the	933	Contains C<undef> until the first watcher is being created, before the
880	backend has been autodetected.	934	backend has been autodetected.
881		935
882	Afterwards it contains the event model that is being used, which is the	936	Afterwards it contains the event model that is being used, which is the
883	name of the Perl class implementing the model. This class is usually one	937	name of the Perl class implementing the model. This class is usually one
884	of the C<AnyEvent::Impl:xxx> modules, but can be any other class in the	938	of the C<AnyEvent::Impl::xxx> modules, but can be any other class in the
885	case AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode> it	939	case AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode> it
886	will be C<urxvt::anyevent>).	940	will be C<urxvt::anyevent>).
887		941
888	=item AnyEvent::detect	942	=item AnyEvent::detect
889		943
890	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model	944	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model
891	if necessary. You should only call this function right before you would	945	if necessary. You should only call this function right before you would
892	have created an AnyEvent watcher anyway, that is, as late as possible at	946	have created an AnyEvent watcher anyway, that is, as late as possible at
893	runtime, and not e.g. while initialising of your module.	947	runtime, and not e.g. during initialisation of your module.
		948
		949	The effect of calling this function is as if a watcher had been created
		950	(specifically, actions that happen "when the first watcher is created"
		951	happen when calling detetc as well).
894		952
895	If you need to do some initialisation before AnyEvent watchers are	953	If you need to do some initialisation before AnyEvent watchers are
896	created, use C<post_detect>.	954	created, use C<post_detect>.
897		955
898	=item $guard = AnyEvent::post_detect { BLOCK }	956	=item $guard = AnyEvent::post_detect { BLOCK }
899		957
900	Arranges for the code block to be executed as soon as the event model is	958	Arranges for the code block to be executed as soon as the event model is
901	autodetected (or immediately if this has already happened).	959	autodetected (or immediately if that has already happened).
902		960
903	The block will be executed I<after> the actual backend has been detected	961	The block will be executed I<after> the actual backend has been detected
904	(C<$AnyEvent::MODEL> is set), but I<before> any watchers have been	962	(C<$AnyEvent::MODEL> is set), but I<before> any watchers have been
905	created, so it is possible to e.g. patch C<@AnyEvent::ISA> or do	963	created, so it is possible to e.g. patch C<@AnyEvent::ISA> or do
906	other initialisations - see the sources of L<AnyEvent::Strict> or	964	other initialisations - see the sources of L<AnyEvent::Strict> or
…		…
915	that automatically removes the callback again when it is destroyed (or	973	that automatically removes the callback again when it is destroyed (or
916	C<undef> when the hook was immediately executed). See L<AnyEvent::AIO> for	974	C<undef> when the hook was immediately executed). See L<AnyEvent::AIO> for
917	a case where this is useful.	975	a case where this is useful.
918		976
919	Example: Create a watcher for the IO::AIO module and store it in	977	Example: Create a watcher for the IO::AIO module and store it in
920	C<$WATCHER>. Only do so after the event loop is initialised, though.	978	C<$WATCHER>, but do so only do so after the event loop is initialised.
921		979
922	our WATCHER;	980	our WATCHER;
923		981
924	my $guard = AnyEvent::post_detect {	982	my $guard = AnyEvent::post_detect {
925	$WATCHER = AnyEvent->io (fh => IO::AIO::poll_fileno, poll => 'r', cb => \&IO::AIO::poll_cb);	983	$WATCHER = AnyEvent->io (fh => IO::AIO::poll_fileno, poll => 'r', cb => \&IO::AIO::poll_cb);
…		…
933	$WATCHER ||= $guard;	991	$WATCHER ||= $guard;
934		992
935	=item @AnyEvent::post_detect	993	=item @AnyEvent::post_detect
936		994
937	If there are any code references in this array (you can C<push> to it	995	If there are any code references in this array (you can C<push> to it
938	before or after loading AnyEvent), then they will called directly after	996	before or after loading AnyEvent), then they will be called directly
939	the event loop has been chosen.	997	after the event loop has been chosen.
940		998
941	You should check C<$AnyEvent::MODEL> before adding to this array, though:	999	You should check C<$AnyEvent::MODEL> before adding to this array, though:
942	if it is defined then the event loop has already been detected, and the	1000	if it is defined then the event loop has already been detected, and the
943	array will be ignored.	1001	array will be ignored.
944		1002
945	Best use C<AnyEvent::post_detect { BLOCK }> when your application allows	1003	Best use C<AnyEvent::post_detect { BLOCK }> when your application allows
946	it,as it takes care of these details.	1004	it, as it takes care of these details.
947		1005
948	This variable is mainly useful for modules that can do something useful	1006	This variable is mainly useful for modules that can do something useful
949	when AnyEvent is used and thus want to know when it is initialised, but do	1007	when AnyEvent is used and thus want to know when it is initialised, but do
950	not need to even load it by default. This array provides the means to hook	1008	not need to even load it by default. This array provides the means to hook
951	into AnyEvent passively, without loading it.	1009	into AnyEvent passively, without loading it.
952		1010
		1011	Example: To load Coro::AnyEvent whenever Coro and AnyEvent are used
		1012	together, you could put this into Coro (this is the actual code used by
		1013	Coro to accomplish this):
		1014
		1015	if (defined $AnyEvent::MODEL) {
		1016	# AnyEvent already initialised, so load Coro::AnyEvent
		1017	require Coro::AnyEvent;
		1018	} else {
		1019	# AnyEvent not yet initialised, so make sure to load Coro::AnyEvent
		1020	# as soon as it is
		1021	push @AnyEvent::post_detect, sub { require Coro::AnyEvent };
		1022	}
		1023
		1024	=item AnyEvent::postpone { BLOCK }
		1025
		1026	Arranges for the block to be executed as soon as possible, but not before
		1027	the call itself returns. In practise, the block will be executed just
		1028	before the event loop polls for new events, or shortly afterwards.
		1029
		1030	This function never returns anything (to make the C<return postpone { ...
		1031	}> idiom more useful.
		1032
		1033	To understand the usefulness of this function, consider a function that
		1034	asynchronously does something for you and returns some transaction
		1035	object or guard to let you cancel the operation. For example,
		1036	C<AnyEvent::Socket::tcp_connect>:
		1037
		1038	# start a conenction attempt unless one is active
		1039	$self->{connect_guard} ||= AnyEvent::Socket::tcp_connect "www.example.net", 80, sub {
		1040	delete $self->{connect_guard};
		1041	...
		1042	};
		1043
		1044	Imagine that this function could instantly call the callback, for
		1045	example, because it detects an obvious error such as a negative port
		1046	number. Invoking the callback before the function returns causes problems
		1047	however: the callback will be called and will try to delete the guard
		1048	object. But since the function hasn't returned yet, there is nothing to
		1049	delete. When the function eventually returns it will assign the guard
		1050	object to C<< $self->{connect_guard} >>, where it will likely never be
		1051	deleted, so the program thinks it is still trying to connect.
		1052
		1053	This is where C<AnyEvent::postpone> should be used. Instead of calling the
		1054	callback directly on error:
		1055
		1056	$cb->(undef), return # signal error to callback, BAD!
		1057	if $some_error_condition;
		1058
		1059	It should use C<postpone>:
		1060
		1061	AnyEvent::postpone { $cb->(undef) }, return # signal error to callback, later
		1062	if $some_error_condition;
		1063
		1064	=item AnyEvent::log $level, $msg[, @args]
		1065
		1066	Log the given C<$msg> at the given C<$level>.
		1067
		1068	If L<AnyEvent::Log> is not loaded then this function makes a simple test
		1069	to see whether the message will be logged. If the test succeeds it will
		1070	load AnyEvent::Log and call C<AnyEvent::Log::log> - consequently, look at
		1071	the L<AnyEvent::Log> documentation for details.
		1072
		1073	If the test fails it will simply return. Right now this happens when a
		1074	numerical loglevel is used and it is larger than the level specified via
		1075	C<$ENV{PERL_ANYEVENT_VERBOSE}>.
		1076
		1077	If you want to sprinkle loads of logging calls around your code, consider
		1078	creating a logger callback with the C<AnyEvent::Log::logger> function,
		1079	which can reduce typing, codesize and can reduce the logging overhead
		1080	enourmously.
		1081
953	=back	1082	=back
954		1083
955	=head1 WHAT TO DO IN A MODULE	1084	=head1 WHAT TO DO IN A MODULE
956		1085
957	As a module author, you should C<use AnyEvent> and call AnyEvent methods	1086	As a module author, you should C<use AnyEvent> and call AnyEvent methods
…		…
967	because it will stall the whole program, and the whole point of using	1096	because it will stall the whole program, and the whole point of using
968	events is to stay interactive.	1097	events is to stay interactive.
969		1098
970	It is fine, however, to call C<< ->recv >> when the user of your module	1099	It is fine, however, to call C<< ->recv >> when the user of your module
971	requests it (i.e. if you create a http request object ad have a method	1100	requests it (i.e. if you create a http request object ad have a method
972	called C<results> that returns the results, it should call C<< ->recv >>	1101	called C<results> that returns the results, it may call C<< ->recv >>
973	freely, as the user of your module knows what she is doing. always).	1102	freely, as the user of your module knows what she is doing. Always).
974		1103
975	=head1 WHAT TO DO IN THE MAIN PROGRAM	1104	=head1 WHAT TO DO IN THE MAIN PROGRAM
976		1105
977	There will always be a single main program - the only place that should	1106	There will always be a single main program - the only place that should
978	dictate which event model to use.	1107	dictate which event model to use.
979		1108
980	If it doesn't care, it can just "use AnyEvent" and use it itself, or not	1109	If the program is not event-based, it need not do anything special, even
981	do anything special (it does not need to be event-based) and let AnyEvent	1110	when it depends on a module that uses an AnyEvent. If the program itself
982	decide which implementation to chose if some module relies on it.	1111	uses AnyEvent, but does not care which event loop is used, all it needs
		1112	to do is C<use AnyEvent>. In either case, AnyEvent will choose the best
		1113	available loop implementation.
983		1114
984	If the main program relies on a specific event model - for example, in	1115	If the main program relies on a specific event model - for example, in
985	Gtk2 programs you have to rely on the Glib module - you should load the	1116	Gtk2 programs you have to rely on the Glib module - you should load the
986	event module before loading AnyEvent or any module that uses it: generally	1117	event module before loading AnyEvent or any module that uses it: generally
987	speaking, you should load it as early as possible. The reason is that	1118	speaking, you should load it as early as possible. The reason is that
988	modules might create watchers when they are loaded, and AnyEvent will	1119	modules might create watchers when they are loaded, and AnyEvent will
989	decide on the event model to use as soon as it creates watchers, and it	1120	decide on the event model to use as soon as it creates watchers, and it
990	might chose the wrong one unless you load the correct one yourself.	1121	might choose the wrong one unless you load the correct one yourself.
991		1122
992	You can chose to use a pure-perl implementation by loading the	1123	You can chose to use a pure-perl implementation by loading the
993	C<AnyEvent::Impl::Perl> module, which gives you similar behaviour	1124	C<AnyEvent::Loop> module, which gives you similar behaviour
994	everywhere, but letting AnyEvent chose the model is generally better.	1125	everywhere, but letting AnyEvent chose the model is generally better.
995		1126
996	=head2 MAINLOOP EMULATION	1127	=head2 MAINLOOP EMULATION
997		1128
998	Sometimes (often for short test scripts, or even standalone programs who	1129	Sometimes (often for short test scripts, or even standalone programs who
…		…
1011		1142
1012		1143
1013	=head1 OTHER MODULES	1144	=head1 OTHER MODULES
1014		1145
1015	The following is a non-exhaustive list of additional modules that use	1146	The following is a non-exhaustive list of additional modules that use
1016	AnyEvent as a client and can therefore be mixed easily with other AnyEvent	1147	AnyEvent as a client and can therefore be mixed easily with other
1017	modules and other event loops in the same program. Some of the modules	1148	AnyEvent modules and other event loops in the same program. Some of the
1018	come with AnyEvent, most are available via CPAN.	1149	modules come as part of AnyEvent, the others are available via CPAN (see
		1150	L<http://search.cpan.org/search?m=module&q=anyevent%3A%3A*> for
		1151	a longer non-exhaustive list), and the list is heavily biased towards
		1152	modules of the AnyEvent author himself :)
1019		1153
1020	=over 4	1154	=over 4
1021		1155
1022	=item L<AnyEvent::Util>	1156	=item L<AnyEvent::Util> (part of the AnyEvent distribution)
1023		1157
1024	Contains various utility functions that replace often-used but blocking	1158	Contains various utility functions that replace often-used blocking
1025	functions such as C<inet_aton> by event-/callback-based versions.	1159	functions such as C<inet_aton> with event/callback-based versions.
1026		1160
1027	=item L<AnyEvent::Socket>	1161	=item L<AnyEvent::Socket> (part of the AnyEvent distribution)
1028		1162
1029	Provides various utility functions for (internet protocol) sockets,	1163	Provides various utility functions for (internet protocol) sockets,
1030	addresses and name resolution. Also functions to create non-blocking tcp	1164	addresses and name resolution. Also functions to create non-blocking tcp
1031	connections or tcp servers, with IPv6 and SRV record support and more.	1165	connections or tcp servers, with IPv6 and SRV record support and more.
1032		1166
1033	=item L<AnyEvent::Handle>	1167	=item L<AnyEvent::Handle> (part of the AnyEvent distribution)
1034		1168
1035	Provide read and write buffers, manages watchers for reads and writes,	1169	Provide read and write buffers, manages watchers for reads and writes,
1036	supports raw and formatted I/O, I/O queued and fully transparent and	1170	supports raw and formatted I/O, I/O queued and fully transparent and
1037	non-blocking SSL/TLS (via L<AnyEvent::TLS>.	1171	non-blocking SSL/TLS (via L<AnyEvent::TLS>).
1038		1172
1039	=item L<AnyEvent::DNS>	1173	=item L<AnyEvent::DNS> (part of the AnyEvent distribution)
1040		1174
1041	Provides rich asynchronous DNS resolver capabilities.	1175	Provides rich asynchronous DNS resolver capabilities.
1042		1176
1043	=item L<AnyEvent::HTTP>	1177	=item L<AnyEvent::HTTP>, L<AnyEvent::IRC>, L<AnyEvent::XMPP>, L<AnyEvent::GPSD>, L<AnyEvent::IGS>, L<AnyEvent::FCP>
1044		1178
1045	A simple-to-use HTTP library that is capable of making a lot of concurrent	1179	Implement event-based interfaces to the protocols of the same name (for
1046	HTTP requests.	1180	the curious, IGS is the International Go Server and FCP is the Freenet
		1181	Client Protocol).
1047		1182
		1183	=item L<AnyEvent::AIO> (part of the AnyEvent distribution)
		1184
		1185	Truly asynchronous (as opposed to non-blocking) I/O, should be in the
		1186	toolbox of every event programmer. AnyEvent::AIO transparently fuses
		1187	L<IO::AIO> and AnyEvent together, giving AnyEvent access to event-based
		1188	file I/O, and much more.
		1189
		1190	=item L<AnyEvent::Fork>, L<AnyEvent::Fork::RPC>, L<AnyEvent::Fork::Pool>, L<AnyEvent::Fork::Remote>
		1191
		1192	These let you safely fork new subprocesses, either locally or
		1193	remotely (e.g.v ia ssh), using some RPC protocol or not, without
		1194	the limitations normally imposed by fork (AnyEvent works fine for
		1195	example). Dynamically-resized worker pools are obviously included as well.
		1196
		1197	And they are quite tiny and fast as well - "abusing" L<AnyEvent::Fork>
		1198	just to exec external programs can easily beat using C<fork> and C<exec>
		1199	(or even C<system>) in most programs.
		1200
		1201	=item L<AnyEvent::Filesys::Notify>
		1202
		1203	AnyEvent is good for non-blocking stuff, but it can't detect file or
		1204	path changes (e.g. "watch this directory for new files", "watch this
		1205	file for changes"). The L<AnyEvent::Filesys::Notify> module promises to
		1206	do just that in a portbale fashion, supporting inotify on GNU/Linux and
		1207	some weird, without doubt broken, stuff on OS X to monitor files. It can
		1208	fall back to blocking scans at regular intervals transparently on other
		1209	platforms, so it's about as portable as it gets.
		1210
		1211	(I haven't used it myself, but it seems the biggest problem with it is
		1212	it quite bad performance).
		1213
1048	=item L<AnyEvent::HTTPD>	1214	=item L<AnyEvent::DBI>
1049		1215
1050	Provides a simple web application server framework.	1216	Executes L<DBI> requests asynchronously in a proxy process for you,
		1217	notifying you in an event-based way when the operation is finished.
1051		1218
1052	=item L<AnyEvent::FastPing>	1219	=item L<AnyEvent::FastPing>
1053		1220
1054	The fastest ping in the west.	1221	The fastest ping in the west.
1055		1222
1056	=item L<AnyEvent::DBI>
1057
1058	Executes L<DBI> requests asynchronously in a proxy process.
1059
1060	=item L<AnyEvent::AIO>
1061
1062	Truly asynchronous I/O, should be in the toolbox of every event
1063	programmer. AnyEvent::AIO transparently fuses L<IO::AIO> and AnyEvent
1064	together.
1065
1066	=item L<AnyEvent::BDB>
1067
1068	Truly asynchronous Berkeley DB access. AnyEvent::BDB transparently fuses
1069	L<BDB> and AnyEvent together.
1070
1071	=item L<AnyEvent::GPSD>
1072
1073	A non-blocking interface to gpsd, a daemon delivering GPS information.
1074
1075	=item L<AnyEvent::IRC>
1076
1077	AnyEvent based IRC client module family (replacing the older Net::IRC3).
1078
1079	=item L<AnyEvent::XMPP>
1080
1081	AnyEvent based XMPP (Jabber protocol) module family (replacing the older
1082	Net::XMPP2>.
1083
1084	=item L<AnyEvent::IGS>
1085
1086	A non-blocking interface to the Internet Go Server protocol (used by
1087	L<App::IGS>).
1088
1089	=item L<Net::FCP>
1090
1091	AnyEvent-based implementation of the Freenet Client Protocol, birthplace
1092	of AnyEvent.
1093
1094	=item L<Event::ExecFlow>
1095
1096	High level API for event-based execution flow control.
1097
1098	=item L<Coro>	1223	=item L<Coro>
1099		1224
1100	Has special support for AnyEvent via L<Coro::AnyEvent>.	1225	Has special support for AnyEvent via L<Coro::AnyEvent>, which allows you
		1226	to simply invert the flow control - don't call us, we will call you:
		1227
		1228	async {
		1229	Coro::AnyEvent::sleep 5; # creates a 5s timer and waits for it
		1230	print "5 seconds later!\n";
		1231
		1232	Coro::AnyEvent::readable *STDIN; # uses an I/O watcher
		1233	my $line = <STDIN>; # works for ttys
		1234
		1235	AnyEvent::HTTP::http_get "url", Coro::rouse_cb;
		1236	my ($body, $hdr) = Coro::rouse_wait;
		1237	};
1101		1238
1102	=back	1239	=back
1103		1240
1104	=cut	1241	=cut
1105		1242
1106	package AnyEvent;	1243	package AnyEvent;
1107		1244
1108	# basically a tuned-down version of common::sense	1245	BEGIN {
1109	sub common_sense {	1246	require "AnyEvent/constants.pl";
1110	# no warnings	1247	&AnyEvent::common_sense;
1111	${^WARNING_BITS} ^= ${^WARNING_BITS};
1112	# use strict vars subs
1113	$^H |= 0x00000600;
1114	}	1248	}
1115
1116	BEGIN { AnyEvent::common_sense }
1117		1249
1118	use Carp ();	1250	use Carp ();
1119		1251
1120	our $VERSION = 4.9;	1252	our $VERSION = '7.05';
1121	our $MODEL;	1253	our $MODEL;
1122
1123	our $AUTOLOAD;
1124	our @ISA;	1254	our @ISA;
1125
1126	our @REGISTRY;	1255	our @REGISTRY;
1127
1128	our $WIN32;
1129
1130	our $VERBOSE;	1256	our $VERBOSE;
		1257	our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred
		1258	our $MAX_SIGNAL_LATENCY = $ENV{PERL_ANYEVENT_MAX_SIGNAL_LATENCY} || 10; # executes after the BEGIN block below (tainting!)
1131		1259
1132	BEGIN {	1260	BEGIN {
1133	eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }";
1134	eval "sub TAINT(){ " . (${^TAINT}*1) . " }";	1261	eval "sub TAINT (){" . (${^TAINT}*1) . "}";
1135		1262
1136	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}	1263	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}
1137	if ${^TAINT};	1264	if ${^TAINT};
1138		1265
1139	$VERBOSE = $ENV{PERL_ANYEVENT_VERBOSE}*1;	1266	$ENV{"PERL_ANYEVENT_$_"} = $ENV{"AE_$_"}
		1267	for grep s/^AE_// && !exists $ENV{"PERL_ANYEVENT_$_"}, keys %ENV;
1140		1268
1141	}	1269	@ENV{grep /^PERL_ANYEVENT_/, keys %ENV} = ()
		1270	if ${^TAINT};
1142		1271
1143	our $MAX_SIGNAL_LATENCY = 10;	1272	# $ENV{PERL_ANYEVENT_xxx} now valid
1144		1273
1145	our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred	1274	$VERBOSE = length $ENV{PERL_ANYEVENT_VERBOSE} ? $ENV{PERL_ANYEVENT_VERBOSE}*1 : 4;
1146		1275
1147	{
1148	my $idx;	1276	my $idx;
1149	$PROTOCOL{$_} = ++$idx	1277	$PROTOCOL{$_} = ++$idx
1150	for reverse split /\s*,\s*/,	1278	for reverse split /\s*,\s*/,
1151	$ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";	1279	$ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";
1152	}	1280	}
1153		1281
		1282	our @post_detect;
		1283
		1284	sub post_detect(&) {
		1285	my ($cb) = @_;
		1286
		1287	push @post_detect, $cb;
		1288
		1289	defined wantarray
		1290	? bless \$cb, "AnyEvent::Util::postdetect"
		1291	: ()
		1292	}
		1293
		1294	sub AnyEvent::Util::postdetect::DESTROY {
		1295	@post_detect = grep $_ != ${$_[0]}, @post_detect;
		1296	}
		1297
		1298	our $POSTPONE_W;
		1299	our @POSTPONE;
		1300
		1301	sub _postpone_exec {
		1302	undef $POSTPONE_W;
		1303
		1304	&{ shift @POSTPONE }
		1305	while @POSTPONE;
		1306	}
		1307
		1308	sub postpone(&) {
		1309	push @POSTPONE, shift;
		1310
		1311	$POSTPONE_W ||= AE::timer (0, 0, \&_postpone_exec);
		1312
		1313	()
		1314	}
		1315
		1316	sub log($$;@) {
		1317	# only load the big bloated module when we actually are about to log something
		1318	if ($_[0] <= ($VERBOSE || 1)) { # also catches non-numeric levels(!) and fatal
		1319	local ($!, $@);
		1320	require AnyEvent::Log; # among other things, sets $VERBOSE to 9
		1321	# AnyEvent::Log overwrites this function
		1322	goto &log;
		1323	}
		1324
		1325	0 # not logged
		1326	}
		1327
		1328	sub _logger($;$) {
		1329	my ($level, $renabled) = @_;
		1330
		1331	$$renabled = $level <= $VERBOSE;
		1332
		1333	my $logger = [(caller)[0], $level, $renabled];
		1334
		1335	$AnyEvent::Log::LOGGER{$logger+0} = $logger;
		1336
		1337	# return unless defined wantarray;
		1338	#
		1339	# require AnyEvent::Util;
		1340	# my $guard = AnyEvent::Util::guard (sub {
		1341	# # "clean up"
		1342	# delete $LOGGER{$logger+0};
		1343	# });
		1344	#
		1345	# sub {
		1346	# return 0 unless $$renabled;
		1347	#
		1348	# $guard if 0; # keep guard alive, but don't cause runtime overhead
		1349	# require AnyEvent::Log unless $AnyEvent::Log::VERSION;
		1350	# package AnyEvent::Log;
		1351	# _log ($logger->[0], $level, @_) # logger->[0] has been converted at load time
		1352	# }
		1353	}
		1354
		1355	if (length $ENV{PERL_ANYEVENT_LOG}) {
		1356	require AnyEvent::Log; # AnyEvent::Log does the thing for us
		1357	}
		1358
1154	my @models = (	1359	our @models = (
1155	[EV:: => AnyEvent::Impl::EV:: , 1],	1360	[EV:: => AnyEvent::Impl::EV::],
1156	[Event:: => AnyEvent::Impl::Event::, 1],	1361	[AnyEvent::Loop:: => AnyEvent::Impl::Perl::],
1157	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl:: , 1],
1158	# everything below here will not (normally) be autoprobed	1362	# everything below here will not (normally) be autoprobed
1159	# as the pureperl backend should work everywhere	1363	# as the pure perl backend should work everywhere
1160	# and is usually faster	1364	# and is usually faster
		1365	[Irssi:: => AnyEvent::Impl::Irssi::], # Irssi has a bogus "Event" package, so msut be near the top
		1366	[Event:: => AnyEvent::Impl::Event::], # slow, stable
1161	[Glib:: => AnyEvent::Impl::Glib:: , 1], # becomes extremely slow with many watchers	1367	[Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers
		1368	# everything below here should not be autoloaded
1162	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy	1369	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
1163	[Irssi:: => AnyEvent::Impl::Irssi::], # Irssi has a bogus "Event" package
1164	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles	1370	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
1165	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program	1371	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program
1166	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza	1372	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
1167	[Wx:: => AnyEvent::Impl::POE::],	1373	[Wx:: => AnyEvent::Impl::POE::],
1168	[Prima:: => AnyEvent::Impl::POE::],	1374	[Prima:: => AnyEvent::Impl::POE::],
1169	# IO::Async is just too broken - we would need workarounds for its	1375	[IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # a bitch to autodetect
1170	# byzantine signal and broken child handling, among others.	1376	[Cocoa::EventLoop:: => AnyEvent::Impl::Cocoa::],
1171	# IO::Async is rather hard to detect, as it doesn't have any	1377	[FLTK:: => AnyEvent::Impl::FLTK::],
1172	# obvious default class.
1173	# [0, IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program
1174	# [0, IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program
1175	# [0, IO::Async::Notifier:: => AnyEvent::Impl::IOAsync::], # requires special main program
1176	);	1378	);
1177		1379
1178	our %method = map +($_ => 1),	1380	our @isa_hook;
		1381
		1382	sub _isa_set {
		1383	my @pkg = ("AnyEvent", (map $_->[0], grep defined, @isa_hook), $MODEL);
		1384
		1385	@{"$pkg[$_-1]::ISA"} = $pkg[$_]
		1386	for 1 .. $#pkg;
		1387
		1388	grep $_ && $_->[1], @isa_hook
		1389	and AE::_reset ();
		1390	}
		1391
		1392	# used for hooking AnyEvent::Strict and AnyEvent::Debug::Wrap into the class hierarchy
		1393	sub _isa_hook($$;$) {
		1394	my ($i, $pkg, $reset_ae) = @_;
		1395
		1396	$isa_hook[$i] = $pkg ? [$pkg, $reset_ae] : undef;
		1397
		1398	_isa_set;
		1399	}
		1400
		1401	# all autoloaded methods reserve the complete glob, not just the method slot.
		1402	# due to bugs in perls method cache implementation.
1179	qw(io timer time now now_update signal child idle condvar one_event DESTROY);	1403	our @methods = qw(io timer time now now_update signal child idle condvar);
1180		1404
1181	our @post_detect;
1182
1183	sub post_detect(&) {	1405	sub detect() {
1184	my ($cb) = @_;	1406	return $MODEL if $MODEL; # some programs keep references to detect
1185		1407
1186	if ($MODEL) {	1408	# IO::Async::Loop::AnyEvent is extremely evil, refuse to work with it
1187	$cb->();	1409	# the author knows about the problems and what it does to AnyEvent as a whole
		1410	# (and the ability of others to use AnyEvent), but simply wants to abuse AnyEvent
		1411	# anyway.
		1412	AnyEvent::log fatal => "IO::Async::Loop::AnyEvent detected - that module is broken by\n"
		1413	. "design, abuses internals and breaks AnyEvent - will not continue."
		1414	if exists $INC{"IO/Async/Loop/AnyEvent.pm"};
1188		1415
1189	undef	1416	local $!; # for good measure
		1417	local $SIG{__DIE__}; # we use eval
		1418
		1419	# free some memory
		1420	*detect = sub () { $MODEL };
		1421	# undef &func doesn't correctly update the method cache. grmbl.
		1422	# so we delete the whole glob. grmbl.
		1423	# otoh, perl doesn't let me undef an active usb, but it lets me free
		1424	# a glob with an active sub. hrm. i hope it works, but perl is
		1425	# usually buggy in this department. sigh.
		1426	delete @{"AnyEvent::"}{@methods};
		1427	undef @methods;
		1428
		1429	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z0-9:]+)$/) {
		1430	my $model = $1;
		1431	$model = "AnyEvent::Impl::$model" unless $model =~ s/::$//;
		1432	if (eval "require $model") {
		1433	AnyEvent::log 7 => "Loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.";
		1434	$MODEL = $model;
1190	} else {	1435	} else {
1191	push @post_detect, $cb;	1436	AnyEvent::log 4 => "Unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@";
1192		1437	}
1193	defined wantarray
1194	? bless \$cb, "AnyEvent::Util::postdetect"
1195	: ()
1196	}	1438	}
1197	}
1198		1439
1199	sub AnyEvent::Util::postdetect::DESTROY {	1440	# check for already loaded models
1200	@post_detect = grep $_ != ${$_[0]}, @post_detect;
1201	}
1202
1203	sub detect() {
1204	unless ($MODEL) {	1441	unless ($MODEL) {
1205	local $SIG{__DIE__};	1442	for (@REGISTRY, @models) {
1206		1443	my ($package, $model) = @$_;
1207	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {	1444	if (${"$package\::VERSION"} > 0) {
1208	my $model = "AnyEvent::Impl::$1";
1209	if (eval "require $model") {	1445	if (eval "require $model") {
		1446	AnyEvent::log 7 => "Autodetected model '$model', using it.";
1210	$MODEL = $model;	1447	$MODEL = $model;
1211	warn "AnyEvent: loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.\n" if $VERBOSE >= 2;	1448	last;
1212	} else {	1449	} else {
1213	warn "AnyEvent: unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@" if $VERBOSE;	1450	AnyEvent::log 8 => "Detected event loop $package, but cannot load '$model', skipping: $@";
		1451	}
1214	}	1452	}
1215	}	1453	}
1216		1454
1217	# check for already loaded models
1218	unless ($MODEL) {	1455	unless ($MODEL) {
		1456	# try to autoload a model
1219	for (@REGISTRY, @models) {	1457	for (@REGISTRY, @models) {
1220	my ($package, $model) = @$_;	1458	my ($package, $model) = @$_;
		1459	if (
		1460	eval "require $package"
1221	if (${"$package\::VERSION"} > 0) {	1461	and ${"$package\::VERSION"} > 0
1222	if (eval "require $model") {	1462	and eval "require $model"
		1463	) {
		1464	AnyEvent::log 7 => "Autoloaded model '$model', using it.";
1223	$MODEL = $model;	1465	$MODEL = $model;
1224	warn "AnyEvent: autodetected model '$model', using it.\n" if $VERBOSE >= 2;
1225	last;	1466	last;
1226	}
1227	}	1467	}
1228	}	1468	}
1229		1469
1230	unless ($MODEL) {
1231	# try to autoload a model
1232	for (@REGISTRY, @models) {
1233	my ($package, $model, $autoload) = @$_;
1234	if (
1235	$autoload
1236	and eval "require $package"
1237	and ${"$package\::VERSION"} > 0
1238	and eval "require $model"
1239	) {
1240	$MODEL = $model;
1241	warn "AnyEvent: autoloaded model '$model', using it.\n" if $VERBOSE >= 2;
1242	last;
1243	}
1244	}
1245
1246	$MODEL	1470	$MODEL
1247	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.\n";	1471	or AnyEvent::log fatal => "Backend autodetection failed - did you properly install AnyEvent?";
1248	}
1249	}	1472	}
1250
1251	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
1252
1253	unshift @ISA, $MODEL;
1254
1255	require AnyEvent::Strict if $ENV{PERL_ANYEVENT_STRICT};
1256
1257	(shift @post_detect)->() while @post_detect;
1258	}	1473	}
1259		1474
		1475	# free memory only needed for probing
		1476	undef @models;
		1477	undef @REGISTRY;
		1478
		1479	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
		1480
		1481	# now nuke some methods that are overridden by the backend.
		1482	# SUPER usage is not allowed in these.
		1483	for (qw(time signal child idle)) {
		1484	undef &{"AnyEvent::Base::$_"}
		1485	if defined &{"$MODEL\::$_"};
		1486	}
		1487
		1488	_isa_set;
		1489
		1490	# we're officially open!
		1491
		1492	if ($ENV{PERL_ANYEVENT_STRICT}) {
		1493	require AnyEvent::Strict;
		1494	}
		1495
		1496	if ($ENV{PERL_ANYEVENT_DEBUG_WRAP}) {
		1497	require AnyEvent::Debug;
		1498	AnyEvent::Debug::wrap ($ENV{PERL_ANYEVENT_DEBUG_WRAP});
		1499	}
		1500
		1501	if (length $ENV{PERL_ANYEVENT_DEBUG_SHELL}) {
		1502	require AnyEvent::Socket;
		1503	require AnyEvent::Debug;
		1504
		1505	my $shell = $ENV{PERL_ANYEVENT_DEBUG_SHELL};
		1506	$shell =~ s/\$\$/$$/g;
		1507
		1508	my ($host, $service) = AnyEvent::Socket::parse_hostport ($shell);
		1509	$AnyEvent::Debug::SHELL = AnyEvent::Debug::shell ($host, $service);
		1510	}
		1511
		1512	# now the anyevent environment is set up as the user told us to, so
		1513	# call the actual user code - post detects
		1514
		1515	(shift @post_detect)->() while @post_detect;
		1516	undef @post_detect;
		1517
		1518	*post_detect = sub(&) {
		1519	shift->();
		1520
		1521	undef
		1522	};
		1523
1260	$MODEL	1524	$MODEL
1261	}	1525	}
1262		1526
1263	sub AUTOLOAD {	1527	for my $name (@methods) {
1264	(my $func = $AUTOLOAD) =~ s/.*://;	1528	*$name = sub {
1265		1529	detect;
1266	$method{$func}	1530	# we use goto because
1267	or Carp::croak "$func: not a valid method for AnyEvent objects";	1531	# a) it makes the thunk more transparent
1268		1532	# b) it allows us to delete the thunk later
1269	detect unless $MODEL;	1533	goto &{ UNIVERSAL::can AnyEvent => "SUPER::$name" }
1270		1534	};
1271	my $class = shift;
1272	$class->$func (@_);
1273	}	1535	}
1274		1536
1275	# utility function to dup a filehandle. this is used by many backends	1537	# utility function to dup a filehandle. this is used by many backends
1276	# to support binding more than one watcher per filehandle (they usually	1538	# to support binding more than one watcher per filehandle (they usually
1277	# allow only one watcher per fd, so we dup it to get a different one).	1539	# allow only one watcher per fd, so we dup it to get a different one).
…		…
1287	# we assume CLOEXEC is already set by perl in all important cases	1549	# we assume CLOEXEC is already set by perl in all important cases
1288		1550
1289	($fh2, $rw)	1551	($fh2, $rw)
1290	}	1552	}
1291		1553
		1554	=head1 SIMPLIFIED AE API
		1555
		1556	Starting with version 5.0, AnyEvent officially supports a second, much
		1557	simpler, API that is designed to reduce the calling, typing and memory
		1558	overhead by using function call syntax and a fixed number of parameters.
		1559
		1560	See the L<AE> manpage for details.
		1561
		1562	=cut
		1563
		1564	package AE;
		1565
		1566	our $VERSION = $AnyEvent::VERSION;
		1567
		1568	sub _reset() {
		1569	eval q{
		1570	# fall back to the main API by default - backends and AnyEvent::Base
		1571	# implementations can overwrite these.
		1572
		1573	sub io($$$) {
		1574	AnyEvent->io (fh => $_[0], poll => $_[1] ? "w" : "r", cb => $_[2])
		1575	}
		1576
		1577	sub timer($$$) {
		1578	AnyEvent->timer (after => $_[0], interval => $_[1], cb => $_[2])
		1579	}
		1580
		1581	sub signal($$) {
		1582	AnyEvent->signal (signal => $_[0], cb => $_[1])
		1583	}
		1584
		1585	sub child($$) {
		1586	AnyEvent->child (pid => $_[0], cb => $_[1])
		1587	}
		1588
		1589	sub idle($) {
		1590	AnyEvent->idle (cb => $_[0]);
		1591	}
		1592
		1593	sub cv(;&) {
		1594	AnyEvent->condvar (@_ ? (cb => $_[0]) : ())
		1595	}
		1596
		1597	sub now() {
		1598	AnyEvent->now
		1599	}
		1600
		1601	sub now_update() {
		1602	AnyEvent->now_update
		1603	}
		1604
		1605	sub time() {
		1606	AnyEvent->time
		1607	}
		1608
		1609	*postpone = \&AnyEvent::postpone;
		1610	*log = \&AnyEvent::log;
		1611	};
		1612	die if $@;
		1613	}
		1614
		1615	BEGIN { _reset }
		1616
1292	package AnyEvent::Base;	1617	package AnyEvent::Base;
1293		1618
1294	# default implementations for many methods	1619	# default implementations for many methods
1295		1620
1296	sub _time {	1621	sub time {
		1622	eval q{ # poor man's autoloading {}
1297	# probe for availability of Time::HiRes	1623	# probe for availability of Time::HiRes
1298	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {	1624	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {
1299	warn "AnyEvent: using Time::HiRes for sub-second timing accuracy.\n" if $VERBOSE >= 8;	1625	*time = sub { Time::HiRes::time () };
1300	*_time = \&Time::HiRes::time;	1626	*AE::time = \& Time::HiRes::time ;
		1627	*now = \&time;
		1628	AnyEvent::log 8 => "using Time::HiRes for sub-second timing accuracy.";
1301	# if (eval "use POSIX (); (POSIX::times())...	1629	# if (eval "use POSIX (); (POSIX::times())...
1302	} else {	1630	} else {
1303	warn "AnyEvent: using built-in time(), WARNING, no sub-second resolution!\n" if $VERBOSE;	1631	*time = sub { CORE::time };
1304	*_time = sub { time }; # epic fail	1632	*AE::time = sub (){ CORE::time };
		1633	*now = \&time;
		1634	AnyEvent::log 3 => "Using built-in time(), no sub-second resolution!";
		1635	}
1305	}	1636	};
		1637	die if $@;
1306		1638
1307	&_time	1639	&time
1308	}	1640	}
1309		1641
1310	sub time { _time }	1642	*now = \&time;
1311	sub now { _time }
1312	sub now_update { }	1643	sub now_update { }
1313		1644
		1645	sub _poll {
		1646	Carp::croak "$AnyEvent::MODEL does not support blocking waits. Caught";
		1647	}
		1648
1314	# default implementation for ->condvar	1649	# default implementation for ->condvar
		1650	# in fact, the default should not be overwritten
1315		1651
1316	sub condvar {	1652	sub condvar {
		1653	eval q{ # poor man's autoloading {}
		1654	*condvar = sub {
1317	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"	1655	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"
		1656	};
		1657
		1658	*AE::cv = sub (;&) {
		1659	bless { @_ ? (_ae_cb => shift) : () }, "AnyEvent::CondVar"
		1660	};
		1661	};
		1662	die if $@;
		1663
		1664	&condvar
1318	}	1665	}
1319		1666
1320	# default implementation for ->signal	1667	# default implementation for ->signal
1321		1668
1322	our $HAVE_ASYNC_INTERRUPT;	1669	our $HAVE_ASYNC_INTERRUPT;
1323		1670
1324	sub _have_async_interrupt() {	1671	sub _have_async_interrupt() {
1325	$HAVE_ASYNC_INTERRUPT = 1*(!$ENV{PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT}	1672	$HAVE_ASYNC_INTERRUPT = 1*(!$ENV{PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT}
1326	&& eval "use Async::Interrupt 1.0 (); 1")	1673	&& eval "use Async::Interrupt 1.02 (); 1")
1327	unless defined $HAVE_ASYNC_INTERRUPT;	1674	unless defined $HAVE_ASYNC_INTERRUPT;
1328		1675
1329	$HAVE_ASYNC_INTERRUPT	1676	$HAVE_ASYNC_INTERRUPT
1330	}	1677	}
1331		1678
1332	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);	1679	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);
1333	our (%SIG_ASY, %SIG_ASY_W);	1680	our (%SIG_ASY, %SIG_ASY_W);
1334	our ($SIG_COUNT, $SIG_TW);	1681	our ($SIG_COUNT, $SIG_TW);
1335		1682
1336	sub _signal_exec {
1337	$HAVE_ASYNC_INTERRUPT
1338	? $SIGPIPE_R->drain
1339	: sysread $SIGPIPE_R, my $dummy, 9;
1340
1341	while (%SIG_EV) {
1342	for (keys %SIG_EV) {
1343	delete $SIG_EV{$_};
1344	$_->() for values %{ $SIG_CB{$_} || {} };
1345	}
1346	}
1347	}
1348
1349	# install a dummy wakeup watcher to reduce signal catching latency	1683	# install a dummy wakeup watcher to reduce signal catching latency
		1684	# used by Impls
1350	sub _sig_add() {	1685	sub _sig_add() {
1351	unless ($SIG_COUNT++) {	1686	unless ($SIG_COUNT++) {
1352	# try to align timer on a full-second boundary, if possible	1687	# try to align timer on a full-second boundary, if possible
1353	my $NOW = AnyEvent->now;	1688	my $NOW = AE::now;
1354		1689
1355	$SIG_TW = AnyEvent->timer (	1690	$SIG_TW = AE::timer
1356	after => $MAX_SIGNAL_LATENCY - ($NOW - int $NOW),	1691	$MAX_SIGNAL_LATENCY - ($NOW - int $NOW),
1357	interval => $MAX_SIGNAL_LATENCY,	1692	$MAX_SIGNAL_LATENCY,
1358	cb => sub { }, # just for the PERL_ASYNC_CHECK	1693	sub { } # just for the PERL_ASYNC_CHECK
1359	);	1694	;
1360	}	1695	}
1361	}	1696	}
1362		1697
1363	sub _sig_del {	1698	sub _sig_del {
1364	undef $SIG_TW	1699	undef $SIG_TW
1365	unless --$SIG_COUNT;	1700	unless --$SIG_COUNT;
1366	}	1701	}
1367		1702
1368	our $_sig_name_init; $_sig_name_init = sub {	1703	our $_sig_name_init; $_sig_name_init = sub {
1369	eval q{ # poor man's autoloading	1704	eval q{ # poor man's autoloading {}
1370	undef $_sig_name_init;	1705	undef $_sig_name_init;
1371		1706
1372	if (_have_async_interrupt) {	1707	if (_have_async_interrupt) {
1373	*sig2num = \&Async::Interrupt::sig2num;	1708	*sig2num = \&Async::Interrupt::sig2num;
1374	*sig2name = \&Async::Interrupt::sig2name;	1709	*sig2name = \&Async::Interrupt::sig2name;
…		…
1398		1733
1399	sub signal {	1734	sub signal {
1400	eval q{ # poor man's autoloading {}	1735	eval q{ # poor man's autoloading {}
1401	# probe for availability of Async::Interrupt	1736	# probe for availability of Async::Interrupt
1402	if (_have_async_interrupt) {	1737	if (_have_async_interrupt) {
1403	warn "AnyEvent: using Async::Interrupt for race-free signal handling.\n" if $VERBOSE >= 8;	1738	AnyEvent::log 8 => "Using Async::Interrupt for race-free signal handling.";
1404		1739
1405	$SIGPIPE_R = new Async::Interrupt::EventPipe;	1740	$SIGPIPE_R = new Async::Interrupt::EventPipe;
1406	$SIG_IO = AnyEvent->io (fh => $SIGPIPE_R->fileno, poll => "r", cb => \&_signal_exec);	1741	$SIG_IO = AE::io $SIGPIPE_R->fileno, 0, \&_signal_exec;
1407		1742
1408	} else {	1743	} else {
1409	warn "AnyEvent: using emulated perl signal handling with latency timer.\n" if $VERBOSE >= 8;	1744	AnyEvent::log 8 => "Using emulated perl signal handling with latency timer.";
1410
1411	require Fcntl;
1412		1745
1413	if (AnyEvent::WIN32) {	1746	if (AnyEvent::WIN32) {
1414	require AnyEvent::Util;	1747	require AnyEvent::Util;
1415		1748
1416	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();	1749	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
1417	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R, 1) if $SIGPIPE_R;	1750	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R, 1) if $SIGPIPE_R;
1418	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W, 1) if $SIGPIPE_W; # just in case	1751	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W, 1) if $SIGPIPE_W; # just in case
1419	} else {	1752	} else {
1420	pipe $SIGPIPE_R, $SIGPIPE_W;	1753	pipe $SIGPIPE_R, $SIGPIPE_W;
1421	fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R;	1754	fcntl $SIGPIPE_R, AnyEvent::F_SETFL, AnyEvent::O_NONBLOCK if $SIGPIPE_R;
1422	fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case	1755	fcntl $SIGPIPE_W, AnyEvent::F_SETFL, AnyEvent::O_NONBLOCK if $SIGPIPE_W; # just in case
1423		1756
1424	# not strictly required, as $^F is normally 2, but let's make sure...	1757	# not strictly required, as $^F is normally 2, but let's make sure...
1425	fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;	1758	fcntl $SIGPIPE_R, AnyEvent::F_SETFD, AnyEvent::FD_CLOEXEC;
1426	fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;	1759	fcntl $SIGPIPE_W, AnyEvent::F_SETFD, AnyEvent::FD_CLOEXEC;
1427	}	1760	}
1428		1761
1429	$SIGPIPE_R	1762	$SIGPIPE_R
1430	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";	1763	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";
1431		1764
1432	$SIG_IO = AnyEvent->io (fh => $SIGPIPE_R, poll => "r", cb => \&_signal_exec);	1765	$SIG_IO = AE::io $SIGPIPE_R, 0, \&_signal_exec;
1433	}	1766	}
1434		1767
1435	*signal = sub {	1768	*signal = $HAVE_ASYNC_INTERRUPT
		1769	? sub {
1436	my (undef, %arg) = @_;	1770	my (undef, %arg) = @_;
1437		1771
1438	my $signal = uc $arg{signal}
1439	or Carp::croak "required option 'signal' is missing";
1440
1441	if ($HAVE_ASYNC_INTERRUPT) {
1442	# async::interrupt	1772	# async::interrupt
1443
1444	$signal = sig2num $signal;	1773	my $signal = sig2num $arg{signal};
1445	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};	1774	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
1446		1775
1447	$SIG_ASY{$signal} ||= new Async::Interrupt	1776	$SIG_ASY{$signal} ||= new Async::Interrupt
1448	cb => sub { undef $SIG_EV{$signal} },	1777	cb => sub { undef $SIG_EV{$signal} },
1449	signal => $signal,	1778	signal => $signal,
1450	pipe => [$SIGPIPE_R->filenos],	1779	pipe => [$SIGPIPE_R->filenos],
1451	pipe_autodrain => 0,	1780	pipe_autodrain => 0,
1452	;	1781	;
1453		1782
1454	} else {	1783	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
		1784	}
		1785	: sub {
		1786	my (undef, %arg) = @_;
		1787
1455	# pure perl	1788	# pure perl
1456
1457	# AE::Util has been loaded in signal
1458	$signal = sig2name $signal;	1789	my $signal = sig2name $arg{signal};
1459	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};	1790	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
1460		1791
1461	$SIG{$signal} ||= sub {	1792	$SIG{$signal} ||= sub {
1462	local $!;	1793	local $!;
1463	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;	1794	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;
1464	undef $SIG_EV{$signal};	1795	undef $SIG_EV{$signal};
1465	};	1796	};
1466		1797
1467	# can't do signal processing without introducing races in pure perl,	1798	# can't do signal processing without introducing races in pure perl,
1468	# so limit the signal latency.	1799	# so limit the signal latency.
1469	_sig_add;	1800	_sig_add;
1470	}
1471		1801
1472	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"	1802	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
		1803	}
1473	};	1804	;
1474		1805
1475	*AnyEvent::Base::signal::DESTROY = sub {	1806	*AnyEvent::Base::signal::DESTROY = sub {
1476	my ($signal, $cb) = @{$_[0]};	1807	my ($signal, $cb) = @{$_[0]};
1477		1808
1478	_sig_del;	1809	_sig_del;
…		…
1485	# print weird messages, or just unconditionally exit	1816	# print weird messages, or just unconditionally exit
1486	# instead of getting the default action.	1817	# instead of getting the default action.
1487	undef $SIG{$signal}	1818	undef $SIG{$signal}
1488	unless keys %{ $SIG_CB{$signal} };	1819	unless keys %{ $SIG_CB{$signal} };
1489	};	1820	};
		1821
		1822	*_signal_exec = sub {
		1823	$HAVE_ASYNC_INTERRUPT
		1824	? $SIGPIPE_R->drain
		1825	: sysread $SIGPIPE_R, (my $dummy), 9;
		1826
		1827	while (%SIG_EV) {
		1828	for (keys %SIG_EV) {
		1829	delete $SIG_EV{$_};
		1830	&$_ for values %{ $SIG_CB{$_} || {} };
		1831	}
		1832	}
		1833	};
1490	};	1834	};
1491	die if $@;	1835	die if $@;
		1836
1492	&signal	1837	&signal
1493	}	1838	}
1494		1839
1495	# default implementation for ->child	1840	# default implementation for ->child
1496		1841
1497	our %PID_CB;	1842	our %PID_CB;
1498	our $CHLD_W;	1843	our $CHLD_W;
1499	our $CHLD_DELAY_W;	1844	our $CHLD_DELAY_W;
1500	our $WNOHANG;
1501		1845
		1846	# used by many Impl's
1502	sub _emit_childstatus($$) {	1847	sub _emit_childstatus($$) {
1503	my (undef, $rpid, $rstatus) = @_;	1848	my (undef, $rpid, $rstatus) = @_;
1504		1849
1505	$_->($rpid, $rstatus)	1850	$_->($rpid, $rstatus)
1506	for values %{ $PID_CB{$rpid} || {} },	1851	for values %{ $PID_CB{$rpid} || {} },
1507	values %{ $PID_CB{0} || {} };	1852	values %{ $PID_CB{0} || {} };
1508	}	1853	}
1509		1854
1510	sub _sigchld {
1511	my $pid;
1512
1513	AnyEvent->_emit_childstatus ($pid, $?)
1514	while ($pid = waitpid -1, $WNOHANG) > 0;
1515	}
1516
1517	sub child {	1855	sub child {
		1856	eval q{ # poor man's autoloading {}
		1857	*_sigchld = sub {
		1858	my $pid;
		1859
		1860	AnyEvent->_emit_childstatus ($pid, $?)
		1861	while ($pid = waitpid -1, WNOHANG) > 0;
		1862	};
		1863
		1864	*child = sub {
1518	my (undef, %arg) = @_;	1865	my (undef, %arg) = @_;
1519		1866
1520	defined (my $pid = $arg{pid} + 0)	1867	my $pid = $arg{pid};
1521	or Carp::croak "required option 'pid' is missing";	1868	my $cb = $arg{cb};
1522		1869
1523	$PID_CB{$pid}{$arg{cb}} = $arg{cb};	1870	$PID_CB{$pid}{$cb+0} = $cb;
1524		1871
1525	# WNOHANG is almost cetrainly 1 everywhere
1526	$WNOHANG ||= $^O =~ /^(?:openbsd|netbsd|linux|freebsd|cygwin|MSWin32)$/
1527	? 1
1528	: eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1;
1529
1530	unless ($CHLD_W) {	1872	unless ($CHLD_W) {
1531	$CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld);	1873	$CHLD_W = AE::signal CHLD => \&_sigchld;
1532	# child could be a zombie already, so make at least one round	1874	# child could be a zombie already, so make at least one round
1533	&_sigchld;	1875	&_sigchld;
1534	}	1876	}
1535		1877
1536	bless [$pid, $arg{cb}], "AnyEvent::Base::child"	1878	bless [$pid, $cb+0], "AnyEvent::Base::child"
1537	}	1879	};
1538		1880
1539	sub AnyEvent::Base::child::DESTROY {	1881	*AnyEvent::Base::child::DESTROY = sub {
1540	my ($pid, $cb) = @{$_[0]};	1882	my ($pid, $icb) = @{$_[0]};
1541		1883
1542	delete $PID_CB{$pid}{$cb};	1884	delete $PID_CB{$pid}{$icb};
1543	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };	1885	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };
1544		1886
1545	undef $CHLD_W unless keys %PID_CB;	1887	undef $CHLD_W unless keys %PID_CB;
		1888	};
		1889	};
		1890	die if $@;
		1891
		1892	&child
1546	}	1893	}
1547		1894
1548	# idle emulation is done by simply using a timer, regardless	1895	# idle emulation is done by simply using a timer, regardless
1549	# of whether the process is idle or not, and not letting	1896	# of whether the process is idle or not, and not letting
1550	# the callback use more than 50% of the time.	1897	# the callback use more than 50% of the time.
1551	sub idle {	1898	sub idle {
		1899	eval q{ # poor man's autoloading {}
		1900	*idle = sub {
1552	my (undef, %arg) = @_;	1901	my (undef, %arg) = @_;
1553		1902
1554	my ($cb, $w, $rcb) = $arg{cb};	1903	my ($cb, $w, $rcb) = $arg{cb};
1555		1904
1556	$rcb = sub {	1905	$rcb = sub {
1557	if ($cb) {	1906	if ($cb) {
1558	$w = _time;	1907	$w = AE::time;
1559	&$cb;	1908	&$cb;
1560	$w = _time - $w;	1909	$w = AE::time - $w;
1561		1910
1562	# never use more then 50% of the time for the idle watcher,	1911	# never use more then 50% of the time for the idle watcher,
1563	# within some limits	1912	# within some limits
1564	$w = 0.0001 if $w < 0.0001;	1913	$w = 0.0001 if $w < 0.0001;
1565	$w = 5 if $w > 5;	1914	$w = 5 if $w > 5;
1566		1915
1567	$w = AnyEvent->timer (after => $w, cb => $rcb);	1916	$w = AE::timer $w, 0, $rcb;
1568	} else {	1917	} else {
1569	# clean up...	1918	# clean up...
1570	undef $w;	1919	undef $w;
1571	undef $rcb;	1920	undef $rcb;
		1921	}
		1922	};
		1923
		1924	$w = AE::timer 0.05, 0, $rcb;
		1925
		1926	bless \\$cb, "AnyEvent::Base::idle"
1572	}	1927	};
		1928
		1929	*AnyEvent::Base::idle::DESTROY = sub {
		1930	undef $${$_[0]};
		1931	};
1573	};	1932	};
		1933	die if $@;
1574		1934
1575	$w = AnyEvent->timer (after => 0.05, cb => $rcb);	1935	&idle
1576
1577	bless \\$cb, "AnyEvent::Base::idle"
1578	}
1579
1580	sub AnyEvent::Base::idle::DESTROY {
1581	undef $${$_[0]};
1582	}	1936	}
1583		1937
1584	package AnyEvent::CondVar;	1938	package AnyEvent::CondVar;
1585		1939
1586	our @ISA = AnyEvent::CondVar::Base::;	1940	our @ISA = AnyEvent::CondVar::Base::;
		1941
		1942	# only to be used for subclassing
		1943	sub new {
		1944	my $class = shift;
		1945	bless AnyEvent->condvar (@_), $class
		1946	}
1587		1947
1588	package AnyEvent::CondVar::Base;	1948	package AnyEvent::CondVar::Base;
1589		1949
1590	#use overload	1950	#use overload
1591	# '&{}' => sub { my $self = shift; sub { $self->send (@_) } },	1951	# '&{}' => sub { my $self = shift; sub { $self->send (@_) } },
…		…
1601		1961
1602	sub _send {	1962	sub _send {
1603	# nop	1963	# nop
1604	}	1964	}
1605		1965
		1966	sub _wait {
		1967	AnyEvent->_poll until $_[0]{_ae_sent};
		1968	}
		1969
1606	sub send {	1970	sub send {
1607	my $cv = shift;	1971	my $cv = shift;
1608	$cv->{_ae_sent} = [@_];	1972	$cv->{_ae_sent} = [@_];
1609	(delete $cv->{_ae_cb})->($cv) if $cv->{_ae_cb};	1973	(delete $cv->{_ae_cb})->($cv) if $cv->{_ae_cb};
1610	$cv->_send;	1974	$cv->_send;
…		…
1617		1981
1618	sub ready {	1982	sub ready {
1619	$_[0]{_ae_sent}	1983	$_[0]{_ae_sent}
1620	}	1984	}
1621		1985
1622	sub _wait {
1623	$WAITING
1624	and !$_[0]{_ae_sent}
1625	and Carp::croak "AnyEvent::CondVar: recursive blocking wait detected";
1626
1627	local $WAITING = 1;
1628	AnyEvent->one_event while !$_[0]{_ae_sent};
1629	}
1630
1631	sub recv {	1986	sub recv {
		1987	unless ($_[0]{_ae_sent}) {
		1988	$WAITING
		1989	and Carp::croak "AnyEvent::CondVar: recursive blocking wait attempted";
		1990
		1991	local $WAITING = 1;
1632	$_[0]->_wait;	1992	$_[0]->_wait;
		1993	}
1633		1994
1634	Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak};	1995	$_[0]{_ae_croak}
1635	wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0]	1996	and Carp::croak $_[0]{_ae_croak};
		1997
		1998	wantarray
		1999	? @{ $_[0]{_ae_sent} }
		2000	: $_[0]{_ae_sent}[0]
1636	}	2001	}
1637		2002
1638	sub cb {	2003	sub cb {
1639	my $cv = shift;	2004	my $cv = shift;
1640		2005
1641	@_	2006	@_
1642	and $cv->{_ae_cb} = shift	2007	and $cv->{_ae_cb} = shift
1643	and $cv->{_ae_sent}	2008	and $cv->{_ae_sent}
1644	and (delete $cv->{_ae_cb})->($cv);	2009	and (delete $cv->{_ae_cb})->($cv);
		2010
1645	$cv->{_ae_cb}	2011	$cv->{_ae_cb}
1646	}	2012	}
1647		2013
1648	sub begin {	2014	sub begin {
1649	++$_[0]{_ae_counter};	2015	++$_[0]{_ae_counter};
…		…
1655	&{ $_[0]{_ae_end_cb} || sub { $_[0]->send } };	2021	&{ $_[0]{_ae_end_cb} || sub { $_[0]->send } };
1656	}	2022	}
1657		2023
1658	# undocumented/compatibility with pre-3.4	2024	# undocumented/compatibility with pre-3.4
1659	*broadcast = \&send;	2025	*broadcast = \&send;
1660	*wait = \&_wait;	2026	*wait = \&recv;
1661
1662	#############################################################################
1663	# "new" API, currently only emulation of it
1664	#############################################################################
1665
1666	package AE;
1667
1668	sub io($$$) {
1669	AnyEvent->io (fh => $_[0], poll => $_[1] ? "w" : "r", cb => $_[2])
1670	}
1671
1672	sub timer($$$) {
1673	AnyEvent->timer (after => $_[0], interval => $_[1], cb => $_[2]);
1674	}
1675
1676	sub signal($$) {
1677	AnyEvent->signal (signal => $_[0], cb => $_[1]);
1678	}
1679
1680	sub child($$) {
1681	AnyEvent->child (pid => $_[0], cb => $_[1]);
1682	}
1683
1684	sub idle($) {
1685	AnyEvent->idle (cb => $_[0]);
1686	}
1687
1688	sub cv() {
1689	AnyEvent->condvar
1690	}
1691
1692	sub now() {
1693	AnyEvent->now
1694	}
1695
1696	sub now_update() {
1697	AnyEvent->now_update
1698	}
1699
1700	sub time() {
1701	AnyEvent->time
1702	}
1703		2027
1704	=head1 ERROR AND EXCEPTION HANDLING	2028	=head1 ERROR AND EXCEPTION HANDLING
1705		2029
1706	In general, AnyEvent does not do any error handling - it relies on the	2030	In general, AnyEvent does not do any error handling - it relies on the
1707	caller to do that if required. The L<AnyEvent::Strict> module (see also	2031	caller to do that if required. The L<AnyEvent::Strict> module (see also
…		…
1719	$Event/EV::DIED->() >>, L<Glib> uses C<< install_exception_handler >> and	2043	$Event/EV::DIED->() >>, L<Glib> uses C<< install_exception_handler >> and
1720	so on.	2044	so on.
1721		2045
1722	=head1 ENVIRONMENT VARIABLES	2046	=head1 ENVIRONMENT VARIABLES
1723		2047
1724	The following environment variables are used by this module or its	2048	AnyEvent supports a number of environment variables that tune the
1725	submodules.	2049	runtime behaviour. They are usually evaluated when AnyEvent is
		2050	loaded, initialised, or a submodule that uses them is loaded. Many of
		2051	them also cause AnyEvent to load additional modules - for example,
		2052	C<PERL_ANYEVENT_DEBUG_WRAP> causes the L<AnyEvent::Debug> module to be
		2053	loaded.
1726		2054
1727	Note that AnyEvent will remove I<all> environment variables starting with	2055	All the environment variables documented here start with
1728	C<PERL_ANYEVENT_> from C<%ENV> when it is loaded while taint mode is	2056	C<PERL_ANYEVENT_>, which is what AnyEvent considers its own
1729	enabled.	2057	namespace. Other modules are encouraged (but by no means required) to use
		2058	C<PERL_ANYEVENT_SUBMODULE> if they have registered the AnyEvent::Submodule
		2059	namespace on CPAN, for any submodule. For example, L<AnyEvent::HTTP> could
		2060	be expected to use C<PERL_ANYEVENT_HTTP_PROXY> (it should not access env
		2061	variables starting with C<AE_>, see below).
		2062
		2063	All variables can also be set via the C<AE_> prefix, that is, instead
		2064	of setting C<PERL_ANYEVENT_VERBOSE> you can also set C<AE_VERBOSE>. In
		2065	case there is a clash btween anyevent and another program that uses
		2066	C<AE_something> you can set the corresponding C<PERL_ANYEVENT_something>
		2067	variable to the empty string, as those variables take precedence.
		2068
		2069	When AnyEvent is first loaded, it copies all C<AE_xxx> env variables
		2070	to their C<PERL_ANYEVENT_xxx> counterpart unless that variable already
		2071	exists. If taint mode is on, then AnyEvent will remove I<all> environment
		2072	variables starting with C<PERL_ANYEVENT_> from C<%ENV> (or replace them
		2073	with C<undef> or the empty string, if the corresaponding C<AE_> variable
		2074	is set).
		2075
		2076	The exact algorithm is currently:
		2077
		2078	1. if taint mode enabled, delete all PERL_ANYEVENT_xyz variables from %ENV
		2079	2. copy over AE_xyz to PERL_ANYEVENT_xyz unless the latter alraedy exists
		2080	3. if taint mode enabled, set all PERL_ANYEVENT_xyz variables to undef.
		2081
		2082	This ensures that child processes will not see the C<AE_> variables.
		2083
		2084	The following environment variables are currently known to AnyEvent:
1730		2085
1731	=over 4	2086	=over 4
1732		2087
1733	=item C<PERL_ANYEVENT_VERBOSE>	2088	=item C<PERL_ANYEVENT_VERBOSE>
1734		2089
1735	By default, AnyEvent will be completely silent except in fatal	2090	By default, AnyEvent will log messages with loglevel C<4> (C<error>) or
1736	conditions. You can set this environment variable to make AnyEvent more	2091	higher (see L<AnyEvent::Log>). You can set this environment variable to a
1737	talkative.	2092	numerical loglevel to make AnyEvent more (or less) talkative.
1738		2093
		2094	If you want to do more than just set the global logging level
		2095	you should have a look at C<PERL_ANYEVENT_LOG>, which allows much more
		2096	complex specifications.
		2097
		2098	When set to C<0> (C<off>), then no messages whatsoever will be logged with
		2099	everything else at defaults.
		2100
1739	When set to C<1> or higher, causes AnyEvent to warn about unexpected	2101	When set to C<5> or higher (C<warn>), AnyEvent warns about unexpected
1740	conditions, such as not being able to load the event model specified by	2102	conditions, such as not being able to load the event model specified by
1741	C<PERL_ANYEVENT_MODEL>.	2103	C<PERL_ANYEVENT_MODEL>, or a guard callback throwing an exception - this
		2104	is the minimum recommended level for use during development.
1742		2105
1743	When set to C<2> or higher, cause AnyEvent to report to STDERR which event	2106	When set to C<7> or higher (info), AnyEvent reports which event model it
1744	model it chooses.	2107	chooses.
1745		2108
1746	When set to C<8> or higher, then AnyEvent will report extra information on	2109	When set to C<8> or higher (debug), then AnyEvent will report extra
1747	which optional modules it loads and how it implements certain features.	2110	information on which optional modules it loads and how it implements
		2111	certain features.
		2112
		2113	=item C<PERL_ANYEVENT_LOG>
		2114
		2115	Accepts rather complex logging specifications. For example, you could log
		2116	all C<debug> messages of some module to stderr, warnings and above to
		2117	stderr, and errors and above to syslog, with:
		2118
		2119	PERL_ANYEVENT_LOG=Some::Module=debug,+log:filter=warn,+%syslog:%syslog=error,syslog
		2120
		2121	For the rather extensive details, see L<AnyEvent::Log>.
		2122
		2123	This variable is evaluated when AnyEvent (or L<AnyEvent::Log>) is loaded,
		2124	so will take effect even before AnyEvent has initialised itself.
		2125
		2126	Note that specifying this environment variable causes the L<AnyEvent::Log>
		2127	module to be loaded, while C<PERL_ANYEVENT_VERBOSE> does not, so only
		2128	using the latter saves a few hundred kB of memory unless a module
		2129	explicitly needs the extra features of AnyEvent::Log.
1748		2130
1749	=item C<PERL_ANYEVENT_STRICT>	2131	=item C<PERL_ANYEVENT_STRICT>
1750		2132
1751	AnyEvent does not do much argument checking by default, as thorough	2133	AnyEvent does not do much argument checking by default, as thorough
1752	argument checking is very costly. Setting this variable to a true value	2134	argument checking is very costly. Setting this variable to a true value
…		…
1754	check the arguments passed to most method calls. If it finds any problems,	2136	check the arguments passed to most method calls. If it finds any problems,
1755	it will croak.	2137	it will croak.
1756		2138
1757	In other words, enables "strict" mode.	2139	In other words, enables "strict" mode.
1758		2140
1759	Unlike C<use strict> (or it's modern cousin, C<< use L<common::sense>	2141	Unlike C<use strict> (or its modern cousin, C<< use L<common::sense>
1760	>>, it is definitely recommended to keep it off in production. Keeping	2142	>>, it is definitely recommended to keep it off in production. Keeping
1761	C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs	2143	C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs
1762	can be very useful, however.	2144	can be very useful, however.
1763		2145
		2146	=item C<PERL_ANYEVENT_DEBUG_SHELL>
		2147
		2148	If this env variable is nonempty, then its contents will be interpreted by
		2149	C<AnyEvent::Socket::parse_hostport> and C<AnyEvent::Debug::shell> (after
		2150	replacing every occurance of C<$$> by the process pid). The shell object
		2151	is saved in C<$AnyEvent::Debug::SHELL>.
		2152
		2153	This happens when the first watcher is created.
		2154
		2155	For example, to bind a debug shell on a unix domain socket in
		2156	F<< /tmp/debug<pid>.sock >>, you could use this:
		2157
		2158	PERL_ANYEVENT_DEBUG_SHELL=/tmp/debug\$\$.sock perlprog
		2159	# connect with e.g.: socat readline /tmp/debug123.sock
		2160
		2161	Or to bind to tcp port 4545 on localhost:
		2162
		2163	PERL_ANYEVENT_DEBUG_SHELL=127.0.0.1:4545 perlprog
		2164	# connect with e.g.: telnet localhost 4545
		2165
		2166	Note that creating sockets in F</tmp> or on localhost is very unsafe on
		2167	multiuser systems.
		2168
		2169	=item C<PERL_ANYEVENT_DEBUG_WRAP>
		2170
		2171	Can be set to C<0>, C<1> or C<2> and enables wrapping of all watchers for
		2172	debugging purposes. See C<AnyEvent::Debug::wrap> for details.
		2173
1764	=item C<PERL_ANYEVENT_MODEL>	2174	=item C<PERL_ANYEVENT_MODEL>
1765		2175
1766	This can be used to specify the event model to be used by AnyEvent, before	2176	This can be used to specify the event model to be used by AnyEvent, before
1767	auto detection and -probing kicks in. It must be a string consisting	2177	auto detection and -probing kicks in.
1768	entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended	2178
		2179	It normally is a string consisting entirely of ASCII letters (e.g. C<EV>
		2180	or C<IOAsync>). The string C<AnyEvent::Impl::> gets prepended and the
1769	and the resulting module name is loaded and if the load was successful,	2181	resulting module name is loaded and - if the load was successful - used as
1770	used as event model. If it fails to load AnyEvent will proceed with	2182	event model backend. If it fails to load then AnyEvent will proceed with
1771	auto detection and -probing.	2183	auto detection and -probing.
1772		2184
1773	This functionality might change in future versions.	2185	If the string ends with C<::> instead (e.g. C<AnyEvent::Impl::EV::>) then
		2186	nothing gets prepended and the module name is used as-is (hint: C<::> at
		2187	the end of a string designates a module name and quotes it appropriately).
1774		2188
1775	For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you	2189	For example, to force the pure perl model (L<AnyEvent::Loop::Perl>) you
1776	could start your program like this:	2190	could start your program like this:
1777		2191
1778	PERL_ANYEVENT_MODEL=Perl perl ...	2192	PERL_ANYEVENT_MODEL=Perl perl ...
		2193
		2194	=item C<PERL_ANYEVENT_IO_MODEL>
		2195
		2196	The current file I/O model - see L<AnyEvent::IO> for more info.
		2197
		2198	At the moment, only C<Perl> (small, pure-perl, synchronous) and
		2199	C<IOAIO> (truly asynchronous) are supported. The default is C<IOAIO> if
		2200	L<AnyEvent::AIO> can be loaded, otherwise it is C<Perl>.
1779		2201
1780	=item C<PERL_ANYEVENT_PROTOCOLS>	2202	=item C<PERL_ANYEVENT_PROTOCOLS>
1781		2203
1782	Used by both L<AnyEvent::DNS> and L<AnyEvent::Socket> to determine preferences	2204	Used by both L<AnyEvent::DNS> and L<AnyEvent::Socket> to determine preferences
1783	for IPv4 or IPv6. The default is unspecified (and might change, or be the result	2205	for IPv4 or IPv6. The default is unspecified (and might change, or be the result
…		…
1796	but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4>	2218	but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4>
1797	- only support IPv4, never try to resolve or contact IPv6	2219	- only support IPv4, never try to resolve or contact IPv6
1798	addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or	2220	addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or
1799	IPv6, but prefer IPv6 over IPv4.	2221	IPv6, but prefer IPv6 over IPv4.
1800		2222
		2223	=item C<PERL_ANYEVENT_HOSTS>
		2224
		2225	This variable, if specified, overrides the F</etc/hosts> file used by
		2226	L<AnyEvent::Socket>C<::resolve_sockaddr>, i.e. hosts aliases will be read
		2227	from that file instead.
		2228
1801	=item C<PERL_ANYEVENT_EDNS0>	2229	=item C<PERL_ANYEVENT_EDNS0>
1802		2230
1803	Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension	2231	Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension for
1804	for DNS. This extension is generally useful to reduce DNS traffic, but	2232	DNS. This extension is generally useful to reduce DNS traffic, especially
1805	some (broken) firewalls drop such DNS packets, which is why it is off by	2233	when DNSSEC is involved, but some (broken) firewalls drop such DNS
1806	default.	2234	packets, which is why it is off by default.
1807		2235
1808	Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce	2236	Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce
1809	EDNS0 in its DNS requests.	2237	EDNS0 in its DNS requests.
1810		2238
1811	=item C<PERL_ANYEVENT_MAX_FORKS>	2239	=item C<PERL_ANYEVENT_MAX_FORKS>
…		…
1817		2245
1818	The default value for the C<max_outstanding> parameter for the default DNS	2246	The default value for the C<max_outstanding> parameter for the default DNS
1819	resolver - this is the maximum number of parallel DNS requests that are	2247	resolver - this is the maximum number of parallel DNS requests that are
1820	sent to the DNS server.	2248	sent to the DNS server.
1821		2249
		2250	=item C<PERL_ANYEVENT_MAX_SIGNAL_LATENCY>
		2251
		2252	Perl has inherently racy signal handling (you can basically choose between
		2253	losing signals and memory corruption) - pure perl event loops (including
		2254	C<AnyEvent::Loop>, when C<Async::Interrupt> isn't available) therefore
		2255	have to poll regularly to avoid losing signals.
		2256
		2257	Some event loops are racy, but don't poll regularly, and some event loops
		2258	are written in C but are still racy. For those event loops, AnyEvent
		2259	installs a timer that regularly wakes up the event loop.
		2260
		2261	By default, the interval for this timer is C<10> seconds, but you can
		2262	override this delay with this environment variable (or by setting
		2263	the C<$AnyEvent::MAX_SIGNAL_LATENCY> variable before creating signal
		2264	watchers).
		2265
		2266	Lower values increase CPU (and energy) usage, higher values can introduce
		2267	long delays when reaping children or waiting for signals.
		2268
		2269	The L<AnyEvent::Async> module, if available, will be used to avoid this
		2270	polling (with most event loops).
		2271
1822	=item C<PERL_ANYEVENT_RESOLV_CONF>	2272	=item C<PERL_ANYEVENT_RESOLV_CONF>
1823		2273
1824	The file to use instead of F</etc/resolv.conf> (or OS-specific	2274	The absolute path to a F<resolv.conf>-style file to use instead of
1825	configuration) in the default resolver. When set to the empty string, no	2275	F</etc/resolv.conf> (or the OS-specific configuration) in the default
1826	default config will be used.	2276	resolver, or the empty string to select the default configuration.
1827		2277
1828	=item C<PERL_ANYEVENT_CA_FILE>, C<PERL_ANYEVENT_CA_PATH>.	2278	=item C<PERL_ANYEVENT_CA_FILE>, C<PERL_ANYEVENT_CA_PATH>.
1829		2279
1830	When neither C<ca_file> nor C<ca_path> was specified during	2280	When neither C<ca_file> nor C<ca_path> was specified during
1831	L<AnyEvent::TLS> context creation, and either of these environment	2281	L<AnyEvent::TLS> context creation, and either of these environment
1832	variables exist, they will be used to specify CA certificate locations	2282	variables are nonempty, they will be used to specify CA certificate
1833	instead of a system-dependent default.	2283	locations instead of a system-dependent default.
1834		2284
1835	=item C<PERL_ANYEVENT_AVOID_GUARD> and C<PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT>	2285	=item C<PERL_ANYEVENT_AVOID_GUARD> and C<PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT>
1836		2286
1837	When these are set to C<1>, then the respective modules are not	2287	When these are set to C<1>, then the respective modules are not
1838	loaded. Mostly good for testing AnyEvent itself.	2288	loaded. Mostly good for testing AnyEvent itself.
…		…
1901	warn "read: $input\n"; # output what has been read	2351	warn "read: $input\n"; # output what has been read
1902	$cv->send if $input =~ /^q/i; # quit program if /^q/i	2352	$cv->send if $input =~ /^q/i; # quit program if /^q/i
1903	},	2353	},
1904	);	2354	);
1905		2355
1906	my $time_watcher; # can only be used once
1907
1908	sub new_timer {
1909	$timer = AnyEvent->timer (after => 1, cb => sub {	2356	my $time_watcher = AnyEvent->timer (after => 1, interval => 1, cb => sub {
1910	warn "timeout\n"; # print 'timeout' about every second	2357	warn "timeout\n"; # print 'timeout' at most every second
1911	&new_timer; # and restart the time
1912	});	2358	});
1913	}
1914
1915	new_timer; # create first timer
1916		2359
1917	$cv->recv; # wait until user enters /^q/i	2360	$cv->recv; # wait until user enters /^q/i
1918		2361
1919	=head1 REAL-WORLD EXAMPLE	2362	=head1 REAL-WORLD EXAMPLE
1920		2363
…		…
1993		2436
1994	The actual code goes further and collects all errors (C<die>s, exceptions)	2437	The actual code goes further and collects all errors (C<die>s, exceptions)
1995	that occurred during request processing. The C<result> method detects	2438	that occurred during request processing. The C<result> method detects
1996	whether an exception as thrown (it is stored inside the $txn object)	2439	whether an exception as thrown (it is stored inside the $txn object)
1997	and just throws the exception, which means connection errors and other	2440	and just throws the exception, which means connection errors and other
1998	problems get reported tot he code that tries to use the result, not in a	2441	problems get reported to the code that tries to use the result, not in a
1999	random callback.	2442	random callback.
2000		2443
2001	All of this enables the following usage styles:	2444	All of this enables the following usage styles:
2002		2445
2003	1. Blocking:	2446	1. Blocking:
…		…
2051	through AnyEvent. The benchmark creates a lot of timers (with a zero	2494	through AnyEvent. The benchmark creates a lot of timers (with a zero
2052	timeout) and I/O watchers (watching STDOUT, a pty, to become writable,	2495	timeout) and I/O watchers (watching STDOUT, a pty, to become writable,
2053	which it is), lets them fire exactly once and destroys them again.	2496	which it is), lets them fire exactly once and destroys them again.
2054		2497
2055	Source code for this benchmark is found as F<eg/bench> in the AnyEvent	2498	Source code for this benchmark is found as F<eg/bench> in the AnyEvent
2056	distribution.	2499	distribution. It uses the L<AE> interface, which makes a real difference
		2500	for the EV and Perl backends only.
2057		2501
2058	=head3 Explanation of the columns	2502	=head3 Explanation of the columns
2059		2503
2060	I<watcher> is the number of event watchers created/destroyed. Since	2504	I<watcher> is the number of event watchers created/destroyed. Since
2061	different event models feature vastly different performances, each event	2505	different event models feature vastly different performances, each event
…		…
2082	watcher.	2526	watcher.
2083		2527
2084	=head3 Results	2528	=head3 Results
2085		2529
2086	name watchers bytes create invoke destroy comment	2530	name watchers bytes create invoke destroy comment
2087	EV/EV 400000 224 0.47 0.35 0.27 EV native interface	2531	EV/EV 100000 223 0.47 0.43 0.27 EV native interface
2088	EV/Any 100000 224 2.88 0.34 0.27 EV + AnyEvent watchers	2532	EV/Any 100000 223 0.48 0.42 0.26 EV + AnyEvent watchers
2089	CoroEV/Any 100000 224 2.85 0.35 0.28 coroutines + Coro::Signal	2533	Coro::EV/Any 100000 223 0.47 0.42 0.26 coroutines + Coro::Signal
2090	Perl/Any 100000 452 4.13 0.73 0.95 pure perl implementation	2534	Perl/Any 100000 431 2.70 0.74 0.92 pure perl implementation
2091	Event/Event 16000 517 32.20 31.80 0.81 Event native interface	2535	Event/Event 16000 516 31.16 31.84 0.82 Event native interface
2092	Event/Any 16000 590 35.85 31.55 1.06 Event + AnyEvent watchers	2536	Event/Any 16000 1203 42.61 34.79 1.80 Event + AnyEvent watchers
2093	IOAsync/Any 16000 989 38.10 32.77 11.13 via IO::Async::Loop::IO_Poll	2537	IOAsync/Any 16000 1911 41.92 27.45 16.81 via IO::Async::Loop::IO_Poll
2094	IOAsync/Any 16000 990 37.59 29.50 10.61 via IO::Async::Loop::Epoll	2538	IOAsync/Any 16000 1726 40.69 26.37 15.25 via IO::Async::Loop::Epoll
2095	Glib/Any 16000 1357 102.33 12.31 51.00 quadratic behaviour	2539	Glib/Any 16000 1118 89.00 12.57 51.17 quadratic behaviour
2096	Tk/Any 2000 1860 27.20 66.31 14.00 SEGV with >> 2000 watchers	2540	Tk/Any 2000 1346 20.96 10.75 8.00 SEGV with >> 2000 watchers
2097	POE/Event 2000 6328 109.99 751.67 14.02 via POE::Loop::Event	2541	POE/Any 2000 6951 108.97 795.32 14.24 via POE::Loop::Event
2098	POE/Select 2000 6027 94.54 809.13 579.80 via POE::Loop::Select	2542	POE/Any 2000 6648 94.79 774.40 575.51 via POE::Loop::Select
2099		2543
2100	=head3 Discussion	2544	=head3 Discussion
2101		2545
2102	The benchmark does I<not> measure scalability of the event loop very	2546	The benchmark does I<not> measure scalability of the event loop very
2103	well. For example, a select-based event loop (such as the pure perl one)	2547	well. For example, a select-based event loop (such as the pure perl one)
…		…
2115	benchmark machine, handling an event takes roughly 1600 CPU cycles with	2559	benchmark machine, handling an event takes roughly 1600 CPU cycles with
2116	EV, 3100 CPU cycles with AnyEvent's pure perl loop and almost 3000000 CPU	2560	EV, 3100 CPU cycles with AnyEvent's pure perl loop and almost 3000000 CPU
2117	cycles with POE.	2561	cycles with POE.
2118		2562
2119	C<EV> is the sole leader regarding speed and memory use, which are both	2563	C<EV> is the sole leader regarding speed and memory use, which are both
2120	maximal/minimal, respectively. Even when going through AnyEvent, it uses	2564	maximal/minimal, respectively. When using the L<AE> API there is zero
		2565	overhead (when going through the AnyEvent API create is about 5-6 times
		2566	slower, with other times being equal, so still uses far less memory than
2121	far less memory than any other event loop and is still faster than Event	2567	any other event loop and is still faster than Event natively).
2122	natively.
2123		2568
2124	The pure perl implementation is hit in a few sweet spots (both the	2569	The pure perl implementation is hit in a few sweet spots (both the
2125	constant timeout and the use of a single fd hit optimisations in the perl	2570	constant timeout and the use of a single fd hit optimisations in the perl
2126	interpreter and the backend itself). Nevertheless this shows that it	2571	interpreter and the backend itself). Nevertheless this shows that it
2127	adds very little overhead in itself. Like any select-based backend its	2572	adds very little overhead in itself. Like any select-based backend its
…		…
2175	(even when used without AnyEvent), but most event loops have acceptable	2620	(even when used without AnyEvent), but most event loops have acceptable
2176	performance with or without AnyEvent.	2621	performance with or without AnyEvent.
2177		2622
2178	=item * The overhead AnyEvent adds is usually much smaller than the overhead of	2623	=item * The overhead AnyEvent adds is usually much smaller than the overhead of
2179	the actual event loop, only with extremely fast event loops such as EV	2624	the actual event loop, only with extremely fast event loops such as EV
2180	adds AnyEvent significant overhead.	2625	does AnyEvent add significant overhead.
2181		2626
2182	=item * You should avoid POE like the plague if you want performance or	2627	=item * You should avoid POE like the plague if you want performance or
2183	reasonable memory usage.	2628	reasonable memory usage.
2184		2629
2185	=back	2630	=back
…		…
2201	In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100	2646	In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100
2202	(1%) are active. This mirrors the activity of large servers with many	2647	(1%) are active. This mirrors the activity of large servers with many
2203	connections, most of which are idle at any one point in time.	2648	connections, most of which are idle at any one point in time.
2204		2649
2205	Source code for this benchmark is found as F<eg/bench2> in the AnyEvent	2650	Source code for this benchmark is found as F<eg/bench2> in the AnyEvent
2206	distribution.	2651	distribution. It uses the L<AE> interface, which makes a real difference
		2652	for the EV and Perl backends only.
2207		2653
2208	=head3 Explanation of the columns	2654	=head3 Explanation of the columns
2209		2655
2210	I<sockets> is the number of sockets, and twice the number of "servers" (as	2656	I<sockets> is the number of sockets, and twice the number of "servers" (as
2211	each server has a read and write socket end).	2657	each server has a read and write socket end).
…		…
2219	a new one that moves the timeout into the future.	2665	a new one that moves the timeout into the future.
2220		2666
2221	=head3 Results	2667	=head3 Results
2222		2668
2223	name sockets create request	2669	name sockets create request
2224	EV 20000 69.01 11.16	2670	EV 20000 62.66 7.99
2225	Perl 20000 73.32 35.87	2671	Perl 20000 68.32 32.64
2226	IOAsync 20000 157.00 98.14 epoll	2672	IOAsync 20000 174.06 101.15 epoll
2227	IOAsync 20000 159.31 616.06 poll	2673	IOAsync 20000 174.67 610.84 poll
2228	Event 20000 212.62 257.32	2674	Event 20000 202.69 242.91
2229	Glib 20000 651.16 1896.30	2675	Glib 20000 557.01 1689.52
2230	POE 20000 349.67 12317.24 uses POE::Loop::Event	2676	POE 20000 341.54 12086.32 uses POE::Loop::Event
2231		2677
2232	=head3 Discussion	2678	=head3 Discussion
2233		2679
2234	This benchmark I<does> measure scalability and overall performance of the	2680	This benchmark I<does> measure scalability and overall performance of the
2235	particular event loop.	2681	particular event loop.
…		…
2361	As you can see, the AnyEvent + EV combination even beats the	2807	As you can see, the AnyEvent + EV combination even beats the
2362	hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl	2808	hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl
2363	backend easily beats IO::Lambda and POE.	2809	backend easily beats IO::Lambda and POE.
2364		2810
2365	And even the 100% non-blocking version written using the high-level (and	2811	And even the 100% non-blocking version written using the high-level (and
2366	slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda by a	2812	slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda
2367	large margin, even though it does all of DNS, tcp-connect and socket I/O	2813	higher level ("unoptimised") abstractions by a large margin, even though
2368	in a non-blocking way.	2814	it does all of DNS, tcp-connect and socket I/O in a non-blocking way.
2369		2815
2370	The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and	2816	The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and
2371	F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are	2817	F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are
2372	part of the IO::lambda distribution and were used without any changes.	2818	part of the IO::Lambda distribution and were used without any changes.
2373		2819
2374		2820
2375	=head1 SIGNALS	2821	=head1 SIGNALS
2376		2822
2377	AnyEvent currently installs handlers for these signals:	2823	AnyEvent currently installs handlers for these signals:
…		…
2414	unless defined $SIG{PIPE};	2860	unless defined $SIG{PIPE};
2415		2861
2416	=head1 RECOMMENDED/OPTIONAL MODULES	2862	=head1 RECOMMENDED/OPTIONAL MODULES
2417		2863
2418	One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and	2864	One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and
2419	it's built-in modules) are required to use it.	2865	its built-in modules) are required to use it.
2420		2866
2421	That does not mean that AnyEvent won't take advantage of some additional	2867	That does not mean that AnyEvent won't take advantage of some additional
2422	modules if they are installed.	2868	modules if they are installed.
2423		2869
2424	This section epxlains which additional modules will be used, and how they	2870	This section explains which additional modules will be used, and how they
2425	affect AnyEvent's operetion.	2871	affect AnyEvent's operation.
2426		2872
2427	=over 4	2873	=over 4
2428		2874
2429	=item L<Async::Interrupt>	2875	=item L<Async::Interrupt>
2430		2876
…		…
2435	catch the signals) with some delay (default is 10 seconds, look for	2881	catch the signals) with some delay (default is 10 seconds, look for
2436	C<$AnyEvent::MAX_SIGNAL_LATENCY>).	2882	C<$AnyEvent::MAX_SIGNAL_LATENCY>).
2437		2883
2438	If this module is available, then it will be used to implement signal	2884	If this module is available, then it will be used to implement signal
2439	catching, which means that signals will not be delayed, and the event loop	2885	catching, which means that signals will not be delayed, and the event loop
2440	will not be interrupted regularly, which is more efficient (And good for	2886	will not be interrupted regularly, which is more efficient (and good for
2441	battery life on laptops).	2887	battery life on laptops).
2442		2888
2443	This affects not just the pure-perl event loop, but also other event loops	2889	This affects not just the pure-perl event loop, but also other event loops
2444	that have no signal handling on their own (e.g. Glib, Tk, Qt).	2890	that have no signal handling on their own (e.g. Glib, Tk, Qt).
2445		2891
…		…
2457	automatic timer adjustments even when no monotonic clock is available,	2903	automatic timer adjustments even when no monotonic clock is available,
2458	can take avdantage of advanced kernel interfaces such as C<epoll> and	2904	can take avdantage of advanced kernel interfaces such as C<epoll> and
2459	C<kqueue>, and is the fastest backend I<by far>. You can even embed	2905	C<kqueue>, and is the fastest backend I<by far>. You can even embed
2460	L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>).	2906	L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>).
2461		2907
		2908	If you only use backends that rely on another event loop (e.g. C<Tk>),
		2909	then this module will do nothing for you.
		2910
2462	=item L<Guard>	2911	=item L<Guard>
2463		2912
2464	The guard module, when used, will be used to implement	2913	The guard module, when used, will be used to implement
2465	C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a	2914	C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a
2466	lot less memory), but otherwise doesn't affect guard operation much. It is	2915	lot less memory), but otherwise doesn't affect guard operation much. It is
2467	purely used for performance.	2916	purely used for performance.
2468		2917
2469	=item L<JSON> and L<JSON::XS>	2918	=item L<JSON> and L<JSON::XS>
2470		2919
2471	This module is required when you want to read or write JSON data via	2920	One of these modules is required when you want to read or write JSON data
2472	L<AnyEvent::Handle>. It is also written in pure-perl, but can take	2921	via L<AnyEvent::Handle>. L<JSON> is also written in pure-perl, but can take
2473	advantage of the ultra-high-speed L<JSON::XS> module when it is installed.	2922	advantage of the ultra-high-speed L<JSON::XS> module when it is installed.
2474
2475	In fact, L<AnyEvent::Handle> will use L<JSON::XS> by default if it is
2476	installed.
2477		2923
2478	=item L<Net::SSLeay>	2924	=item L<Net::SSLeay>
2479		2925
2480	Implementing TLS/SSL in Perl is certainly interesting, but not very	2926	Implementing TLS/SSL in Perl is certainly interesting, but not very
2481	worthwhile: If this module is installed, then L<AnyEvent::Handle> (with	2927	worthwhile: If this module is installed, then L<AnyEvent::Handle> (with
2482	the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL.	2928	the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL.
2483		2929
2484	=item L<Time::HiRes>	2930	=item L<Time::HiRes>
2485		2931
2486	This module is part of perl since release 5.008. It will be used when the	2932	This module is part of perl since release 5.008. It will be used when the
2487	chosen event library does not come with a timing source on it's own. The	2933	chosen event library does not come with a timing source of its own. The
2488	pure-perl event loop (L<AnyEvent::Impl::Perl>) will additionally use it to	2934	pure-perl event loop (L<AnyEvent::Loop>) will additionally load it to
2489	try to use a monotonic clock for timing stability.	2935	try to use a monotonic clock for timing stability.
2490		2936
		2937	=item L<AnyEvent::AIO> (and L<IO::AIO>)
		2938
		2939	The default implementation of L<AnyEvent::IO> is to do I/O synchronously,
		2940	stopping programs while they access the disk, which is fine for a lot of
		2941	programs.
		2942
		2943	Installing AnyEvent::AIO (and its IO::AIO dependency) makes it switch to
		2944	a true asynchronous implementation, so event processing can continue even
		2945	while waiting for disk I/O.
		2946
2491	=back	2947	=back
2492		2948
2493		2949
2494	=head1 FORK	2950	=head1 FORK
2495		2951
2496	Most event libraries are not fork-safe. The ones who are usually are	2952	Most event libraries are not fork-safe. The ones who are usually are
2497	because they rely on inefficient but fork-safe C<select> or C<poll>	2953	because they rely on inefficient but fork-safe C<select> or C<poll> calls
2498	calls. Only L<EV> is fully fork-aware.	2954	- higher performance APIs such as BSD's kqueue or the dreaded Linux epoll
		2955	are usually badly thought-out hacks that are incompatible with fork in
		2956	one way or another. Only L<EV> is fully fork-aware and ensures that you
		2957	continue event-processing in both parent and child (or both, if you know
		2958	what you are doing).
		2959
		2960	This means that, in general, you cannot fork and do event processing in
		2961	the child if the event library was initialised before the fork (which
		2962	usually happens when the first AnyEvent watcher is created, or the library
		2963	is loaded).
2499		2964
2500	If you have to fork, you must either do so I<before> creating your first	2965	If you have to fork, you must either do so I<before> creating your first
2501	watcher OR you must not use AnyEvent at all in the child OR you must do	2966	watcher OR you must not use AnyEvent at all in the child OR you must do
2502	something completely out of the scope of AnyEvent.	2967	something completely out of the scope of AnyEvent (see below).
		2968
		2969	The problem of doing event processing in the parent I<and> the child
		2970	is much more complicated: even for backends that I<are> fork-aware or
		2971	fork-safe, their behaviour is not usually what you want: fork clones all
		2972	watchers, that means all timers, I/O watchers etc. are active in both
		2973	parent and child, which is almost never what you want. Using C<exec>
		2974	to start worker children from some kind of manage prrocess is usually
		2975	preferred, because it is much easier and cleaner, at the expense of having
		2976	to have another binary.
		2977
		2978	In addition to logical problems with fork, there are also implementation
		2979	problems. For example, on POSIX systems, you cannot fork at all in Perl
		2980	code if a thread (I am talking of pthreads here) was ever created in the
		2981	process, and this is just the tip of the iceberg. In general, using fork
		2982	from Perl is difficult, and attempting to use fork without an exec to
		2983	implement some kind of parallel processing is almost certainly doomed.
		2984
		2985	To safely fork and exec, you should use a module such as
		2986	L<Proc::FastSpawn> that let's you safely fork and exec new processes.
		2987
		2988	If you want to do multiprocessing using processes, you can
		2989	look at the L<AnyEvent::Fork> module (and some related modules
		2990	such as L<AnyEvent::Fork::RPC>, L<AnyEvent::Fork::Pool> and
		2991	L<AnyEvent::Fork::Remote>). This module allows you to safely create
		2992	subprocesses without any limitations - you can use X11 toolkits or
		2993	AnyEvent in the children created by L<AnyEvent::Fork> safely and without
		2994	any special precautions.
2503		2995
2504		2996
2505	=head1 SECURITY CONSIDERATIONS	2997	=head1 SECURITY CONSIDERATIONS
2506		2998
2507	AnyEvent can be forced to load any event model via	2999	AnyEvent can be forced to load any event model via
…		…
2537	pronounced).	3029	pronounced).
2538		3030
2539		3031
2540	=head1 SEE ALSO	3032	=head1 SEE ALSO
2541		3033
2542	Utility functions: L<AnyEvent::Util>.	3034	Tutorial/Introduction: L<AnyEvent::Intro>.
2543		3035
2544	Event modules: L<EV>, L<EV::Glib>, L<Glib::EV>, L<Event>, L<Glib::Event>,	3036	FAQ: L<AnyEvent::FAQ>.
2545	L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.	3037
		3038	Utility functions: L<AnyEvent::Util> (misc. grab-bag), L<AnyEvent::Log>
		3039	(simply logging).
		3040
		3041	Development/Debugging: L<AnyEvent::Strict> (stricter checking),
		3042	L<AnyEvent::Debug> (interactive shell, watcher tracing).
		3043
		3044	Supported event modules: L<AnyEvent::Loop>, L<EV>, L<EV::Glib>,
		3045	L<Glib::EV>, L<Event>, L<Glib::Event>, L<Glib>, L<Tk>, L<Event::Lib>,
		3046	L<Qt>, L<POE>, L<FLTK>.
2546		3047
2547	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,	3048	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,
2548	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,	3049	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,
2549	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,	3050	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,
2550	L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>, L<Anyevent::Impl::Irssi>.	3051	L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>, L<Anyevent::Impl::Irssi>,
		3052	L<AnyEvent::Impl::FLTK>.
2551		3053
2552	Non-blocking file handles, sockets, TCP clients and	3054	Non-blocking handles, pipes, stream sockets, TCP clients and
2553	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.	3055	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.
2554		3056
		3057	Asynchronous File I/O: L<AnyEvent::IO>.
		3058
2555	Asynchronous DNS: L<AnyEvent::DNS>.	3059	Asynchronous DNS: L<AnyEvent::DNS>.
2556		3060
2557	Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>,	3061	Thread support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>.
2558	L<Coro::Event>,
2559		3062
2560	Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::XMPP>,	3063	Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::IRC>,
2561	L<AnyEvent::HTTP>.	3064	L<AnyEvent::HTTP>.
2562		3065
2563		3066
2564	=head1 AUTHOR	3067	=head1 AUTHOR
2565		3068
2566	Marc Lehmann <schmorp@schmorp.de>	3069	Marc Lehmann <schmorp@schmorp.de>
2567	http://home.schmorp.de/	3070	http://anyevent.schmorp.de
2568		3071
2569	=cut	3072	=cut
2570		3073
2571	1	3074	1
2572		3075

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