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Revision 1.251 by root, Mon Jul 20 22:39:57 2009 UTC vs.
Revision 1.398 by root, Tue Mar 27 16:21:11 2012 UTC

1	=head1 NAME	1	=head1 NAME
2		2
3	AnyEvent - events independent of event loop implementation	3	AnyEvent - the DBI of event loop programming
4		4
5	EV, Event, Glib, Tk, Perl, Event::Lib, Qt and POE are various supported	5	EV, Event, Glib, Tk, Perl, Event::Lib, Irssi, rxvt-unicode, IO::Async, Qt,
6	event loops.	6	FLTK and POE are various supported event loops/environments.
7		7
8	=head1 SYNOPSIS	8	=head1 SYNOPSIS
9		9
10	use AnyEvent;	10	use AnyEvent;
11		11
		12	# if you prefer function calls, look at the AE manpage for
		13	# an alternative API.
		14
12	# file descriptor readable	15	# file handle or descriptor readable
13	my $w = AnyEvent->io (fh => $fh, poll => "r", cb => sub { ... });	16	my $w = AnyEvent->io (fh => $fh, poll => "r", cb => sub { ... });
14		17
15	# one-shot or repeating timers	18	# one-shot or repeating timers
16	my $w = AnyEvent->timer (after => $seconds, cb => sub { ... });	19	my $w = AnyEvent->timer (after => $seconds, cb => sub { ... });
17	my $w = AnyEvent->timer (after => $seconds, interval => $seconds, cb => ...	20	my $w = AnyEvent->timer (after => $seconds, interval => $seconds, cb => ...);
18		21
19	print AnyEvent->now; # prints current event loop time	22	print AnyEvent->now; # prints current event loop time
20	print AnyEvent->time; # think Time::HiRes::time or simply CORE::time.	23	print AnyEvent->time; # think Time::HiRes::time or simply CORE::time.
21		24
22	# POSIX signal	25	# POSIX signal
…		…
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	Respository>, at L<http://anyevent.schmorp.de>, for more info.	57	Repository>, at L<http://anyevent.schmorp.de>, for more info.
53		58
54	=head1 WHY YOU SHOULD USE THIS MODULE (OR NOT)	59	=head1 WHY YOU SHOULD USE THIS MODULE (OR NOT)
55		60
56	Glib, POE, IO::Async, Event... CPAN offers event models by the dozen	61	Glib, POE, IO::Async, Event... CPAN offers event models by the dozen
57	nowadays. So what is different about AnyEvent?	62	nowadays. So what is different about AnyEvent?
…		…
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	});
…		…
180	Note that C<my $w; $w => combination. This is necessary because in Perl,	184	Note that C<my $w; $w => combination. This is necessary because in Perl,
181	my variables are only visible after the statement in which they are	185	my variables are only visible after the statement in which they are
182	declared.	186	declared.
183		187
184	=head2 I/O WATCHERS	188	=head2 I/O WATCHERS
		189
		190	$w = AnyEvent->io (
		191	fh => <filehandle_or_fileno>,
		192	poll => <"r" or "w">,
		193	cb => <callback>,
		194	);
185		195
186	You can create an I/O watcher by calling the C<< AnyEvent->io >> method	196	You can create an I/O watcher by calling the C<< AnyEvent->io >> method
187	with the following mandatory key-value pairs as arguments:	197	with the following mandatory key-value pairs as arguments:
188		198
189	C<fh> is the Perl I<file handle> (or a naked file descriptor) to watch	199	C<fh> is the Perl I<file handle> (or a naked file descriptor) to watch
…		…
204		214
205	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.
206	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
207	underlying file descriptor.	217	underlying file descriptor.
208		218
209	Some event loops issue spurious readyness notifications, so you should	219	Some event loops issue spurious readiness notifications, so you should
210	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
211	handles.	221	handles.
212		222
213	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
214	watcher.	224	watcher.
…		…
219	undef $w;	229	undef $w;
220	});	230	});
221		231
222	=head2 TIME WATCHERS	232	=head2 TIME WATCHERS
223		233
		234	$w = AnyEvent->timer (after => <seconds>, cb => <callback>);
		235
		236	$w = AnyEvent->timer (
		237	after => <fractional_seconds>,
		238	interval => <fractional_seconds>,
		239	cb => <callback>,
		240	);
		241
224	You can create a time watcher by calling the C<< AnyEvent->timer >>	242	You can create a time watcher by calling the C<< AnyEvent->timer >>
225	method with the following mandatory arguments:	243	method with the following mandatory arguments:
226		244
227	C<after> specifies after how many seconds (fractional values are	245	C<after> specifies after how many seconds (fractional values are
228	supported) the callback should be invoked. C<cb> is the callback to invoke	246	supported) the callback should be invoked. C<cb> is the callback to invoke
…		…
230		248
231	Although the callback might get passed parameters, their value and	249	Although the callback might get passed parameters, their value and
232	presence is undefined and you cannot rely on them. Portable AnyEvent	250	presence is undefined and you cannot rely on them. Portable AnyEvent
233	callbacks cannot use arguments passed to time watcher callbacks.	251	callbacks cannot use arguments passed to time watcher callbacks.
234		252
235	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
236	parameter, C<interval>, as a strictly positive number (> 0), then the	254	parameter, C<interval>, as a strictly positive number (> 0), then the
237	callback will be invoked regularly at that interval (in fractional	255	callback will be invoked regularly at that interval (in fractional
238	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
239	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.
240		258
241	The callback will be rescheduled before invoking the callback, but no	259	The callback will be rescheduled before invoking the callback, but no
242	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
243	only approximate.	261	only approximate.
244		262
245	Example: fire an event after 7.7 seconds.	263	Example: fire an event after 7.7 seconds.
246		264
247	my $w = AnyEvent->timer (after => 7.7, cb => sub {	265	my $w = AnyEvent->timer (after => 7.7, cb => sub {
…		…
265		283
266	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
267	use absolute time internally. This makes a difference when your clock	285	use absolute time internally. This makes a difference when your clock
268	"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
269	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
270	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.
271		289
272	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
273	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
274	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)
275	timers.	293	timers.
276		294
277	AnyEvent always prefers relative timers, if available, matching the	295	AnyEvent always prefers relative timers, if available, matching the
278	AnyEvent API.	296	AnyEvent API.
…		…
300	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
301	function to call when you want to know the current time.>	319	function to call when you want to know the current time.>
302		320
303	This function is also often faster then C<< AnyEvent->time >>, and	321	This function is also often faster then C<< AnyEvent->time >>, and
304	thus the preferred method if you want some timestamp (for example,	322	thus the preferred method if you want some timestamp (for example,
305	L<AnyEvent::Handle> uses this to update it's activity timeouts).	323	L<AnyEvent::Handle> uses this to update its activity timeouts).
306		324
307	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
308	with your timing, you can skip it without bad conscience.	326	with your timing; you can skip it without a bad conscience.
309		327
310	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>
311	and L<EV> and the following set-up:	329	and L<EV> and the following set-up:
312		330
313	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
314	time=500 (assume no other callbacks delay processing). In your callback,	332	time=500 (assume no other callbacks delay processing). In your callback,
315	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
316	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
317	after three seconds.	335	after three seconds.
318		336
…		…
338	difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into	356	difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into
339	account.	357	account.
340		358
341	=item AnyEvent->now_update	359	=item AnyEvent->now_update
342		360
343	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
344	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 >>,
345	AnyEvent->now >>, above).	363	above).
346		364
347	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
348	this "current" time will differ substantially from the real time, which	366	this "current" time will differ substantially from the real time, which
349	might affect timers and time-outs.	367	might affect timers and time-outs.
350		368
351	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
352	event loop's idea of "current time".	370	event loop's idea of "current time".
353		371
		372	A typical example would be a script in a web server (e.g. C<mod_perl>) -
		373	when mod_perl executes the script, then the event loop will have the wrong
		374	idea about the "current time" (being potentially far in the past, when the
		375	script ran the last time). In that case you should arrange a call to C<<
		376	AnyEvent->now_update >> each time the web server process wakes up again
		377	(e.g. at the start of your script, or in a handler).
		378
354	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.
355		380
356	=back	381	=back
357		382
358	=head2 SIGNAL WATCHERS	383	=head2 SIGNAL WATCHERS
		384
		385	$w = AnyEvent->signal (signal => <uppercase_signal_name>, cb => <callback>);
359		386
360	You can watch for signals using a signal watcher, C<signal> is the signal	387	You can watch for signals using a signal watcher, C<signal> is the signal
361	I<name> in uppercase and without any C<SIG> prefix, C<cb> is the Perl	388	I<name> in uppercase and without any C<SIG> prefix, C<cb> is the Perl
362	callback to be invoked whenever a signal occurs.	389	callback to be invoked whenever a signal occurs.
363		390
…		…
380		407
381	Example: exit on SIGINT	408	Example: exit on SIGINT
382		409
383	my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });	410	my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });
384		411
		412	=head3 Restart Behaviour
		413
		414	While restart behaviour is up to the event loop implementation, most will
		415	not restart syscalls (that includes L<Async::Interrupt> and AnyEvent's
		416	pure perl implementation).
		417
		418	=head3 Safe/Unsafe Signals
		419
		420	Perl signals can be either "safe" (synchronous to opcode handling)
		421	or "unsafe" (asynchronous) - the former might delay signal delivery
		422	indefinitely, the latter might corrupt your memory.
		423
		424	AnyEvent signal handlers are, in addition, synchronous to the event loop,
		425	i.e. they will not interrupt your running perl program but will only be
		426	called as part of the normal event handling (just like timer, I/O etc.
		427	callbacks, too).
		428
385	=head3 Signal Races, Delays and Workarounds	429	=head3 Signal Races, Delays and Workarounds
386		430
387	Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support attaching	431	Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support
388	callbacks to signals in a generic way, which is a pity, as you cannot do	432	attaching callbacks to signals in a generic way, which is a pity,
389	race-free signal handling in perl. AnyEvent will try to do it's best, but	433	as you cannot do race-free signal handling in perl, requiring
		434	C libraries for this. AnyEvent will try to do its best, which
390	in some cases, signals will be delayed. The maximum time a signal might	435	means in some cases, signals will be delayed. The maximum time
391	be delayed is specified in C<$AnyEvent::MAX_SIGNAL_LATENCY> (default: 10	436	a signal might be delayed is 10 seconds by default, but can
392	seconds). This variable can be changed only before the first signal	437	be overriden via C<$ENV{PERL_ANYEVENT_MAX_SIGNAL_LATENCY}> or
393	watcher is created, and should be left alone otherwise. Higher values	438	C<$AnyEvent::MAX_SIGNAL_LATENCY> - see the L<ENVIRONMENT VARIABLES>
394	will cause fewer spurious wake-ups, which is better for power and CPU	439	section for details.
		440
395	saving. All these problems can be avoided by installing the optional	441	All these problems can be avoided by installing the optional
396	L<Async::Interrupt> module. This will not work with inherently broken	442	L<Async::Interrupt> module, which works with most event loops. It will not
397	event loops such as L<Event> or L<Event::Lib> (and not with L<POE>	443	work with inherently broken event loops such as L<Event> or L<Event::Lib>
398	currently, as POE does it's own workaround with one-second latency). With	444	(and not with L<POE> currently). For those, you just have to suffer the
399	those, you just have to suffer the delays.	445	delays.
400		446
401	=head2 CHILD PROCESS WATCHERS	447	=head2 CHILD PROCESS WATCHERS
402		448
		449	$w = AnyEvent->child (pid => <process id>, cb => <callback>);
		450
403	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.
404		452
405	The child process is specified by the C<pid> argument (if set to C<0>, it	453	The child process is specified by the C<pid> argument (on some backends,
406	watches for any child process exit). The watcher will triggered only when	454	using C<0> watches for any child process exit, on others this will
407	the child process has finished and an exit status is available, not on	455	croak). The watcher will be triggered only when the child process has
408	any trace events (stopped/continued).	456	finished and an exit status is available, not on any trace events
		457	(stopped/continued).
409		458
410	The callback will be called with the pid and exit status (as returned by	459	The callback will be called with the pid and exit status (as returned by
411	waitpid), so unlike other watcher types, you I<can> rely on child watcher	460	waitpid), so unlike other watcher types, you I<can> rely on child watcher
412	callback arguments.	461	callback arguments.
413		462
…		…
431	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
432	watcher before you C<fork> the child (alternatively, you can call	481	watcher before you C<fork> the child (alternatively, you can call
433	C<AnyEvent::detect>).	482	C<AnyEvent::detect>).
434		483
435	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
436	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
437	mentioned in the description of signal watchers apply.	486	problems mentioned in the description of signal watchers apply.
438		487
439	Example: fork a process and wait for it	488	Example: fork a process and wait for it
440		489
441	my $done = AnyEvent->condvar;	490	my $done = AnyEvent->condvar;
442		491
…		…
454	# do something else, then wait for process exit	503	# do something else, then wait for process exit
455	$done->recv;	504	$done->recv;
456		505
457	=head2 IDLE WATCHERS	506	=head2 IDLE WATCHERS
458		507
459	Sometimes there is a need to do something, but it is not so important	508	$w = AnyEvent->idle (cb => <callback>);
460	to do it instantly, but only when there is nothing better to do. This
461	"nothing better to do" is usually defined to be "no other events need
462	attention by the event loop".
463		509
464	Idle watchers ideally get invoked when the event loop has nothing	510	This will repeatedly invoke the callback after the process becomes idle,
465	better to do, just before it would block the process to wait for new	511	until either the watcher is destroyed or new events have been detected.
466	events. Instead of blocking, the idle watcher is invoked.
467		512
468	Most event loops unfortunately do not really support idle watchers (only	513	Idle watchers are useful when there is a need to do something, but it
		514	is not so important (or wise) to do it instantly. The callback will be
		515	invoked only when there is "nothing better to do", which is usually
		516	defined as "all outstanding events have been handled and no new events
		517	have been detected". That means that idle watchers ideally get invoked
		518	when the event loop has just polled for new events but none have been
		519	detected. Instead of blocking to wait for more events, the idle watchers
		520	will be invoked.
		521
		522	Unfortunately, most event loops do not really support idle watchers (only
469	EV, Event and Glib do it in a usable fashion) - for the rest, AnyEvent	523	EV, Event and Glib do it in a usable fashion) - for the rest, AnyEvent
470	will simply call the callback "from time to time".	524	will simply call the callback "from time to time".
471		525
472	Example: read lines from STDIN, but only process them when the	526	Example: read lines from STDIN, but only process them when the
473	program is otherwise idle:	527	program is otherwise idle:
…		…
489	});	543	});
490	});	544	});
491		545
492	=head2 CONDITION VARIABLES	546	=head2 CONDITION VARIABLES
493		547
		548	$cv = AnyEvent->condvar;
		549
		550	$cv->send (<list>);
		551	my @res = $cv->recv;
		552
494	If you are familiar with some event loops you will know that all of them	553	If you are familiar with some event loops you will know that all of them
495	require you to run some blocking "loop", "run" or similar function that	554	require you to run some blocking "loop", "run" or similar function that
496	will actively watch for new events and call your callbacks.	555	will actively watch for new events and call your callbacks.
497		556
498	AnyEvent is slightly different: it expects somebody else to run the event	557	AnyEvent is slightly different: it expects somebody else to run the event
499	loop and will only block when necessary (usually when told by the user).	558	loop and will only block when necessary (usually when told by the user).
500		559
501	The instrument to do that is called a "condition variable", so called	560	The tool to do that is called a "condition variable", so called because
502	because they represent a condition that must become true.	561	they represent a condition that must become true.
503		562
504	Now is probably a good time to look at the examples further below.	563	Now is probably a good time to look at the examples further below.
505		564
506	Condition variables can be created by calling the C<< AnyEvent->condvar	565	Condition variables can be created by calling the C<< AnyEvent->condvar
507	>> method, usually without arguments. The only argument pair allowed is	566	>> method, usually without arguments. The only argument pair allowed is
…		…
512	After creation, the condition variable is "false" until it becomes "true"	571	After creation, the condition variable is "false" until it becomes "true"
513	by calling the C<send> method (or calling the condition variable as if it	572	by calling the C<send> method (or calling the condition variable as if it
514	were a callback, read about the caveats in the description for the C<<	573	were a callback, read about the caveats in the description for the C<<
515	->send >> method).	574	->send >> method).
516		575
517	Condition variables are similar to callbacks, except that you can	576	Since condition variables are the most complex part of the AnyEvent API, here are
518	optionally wait for them. They can also be called merge points - points	577	some different mental models of what they are - pick the ones you can connect to:
519	in time where multiple outstanding events have been processed. And yet	578
520	another way to call them is transactions - each condition variable can be	579	=over 4
521	used to represent a transaction, which finishes at some point and delivers	580
522	a result. And yet some people know them as "futures" - a promise to	581	=item * Condition variables are like callbacks - you can call them (and pass them instead
523	compute/deliver something that you can wait for.	582	of callbacks). Unlike callbacks however, you can also wait for them to be called.
		583
		584	=item * Condition variables are signals - one side can emit or send them,
		585	the other side can wait for them, or install a handler that is called when
		586	the signal fires.
		587
		588	=item * Condition variables are like "Merge Points" - points in your program
		589	where you merge multiple independent results/control flows into one.
		590
		591	=item * Condition variables represent a transaction - functions that start
		592	some kind of transaction can return them, leaving the caller the choice
		593	between waiting in a blocking fashion, or setting a callback.
		594
		595	=item * Condition variables represent future values, or promises to deliver
		596	some result, long before the result is available.
		597
		598	=back
524		599
525	Condition variables are very useful to signal that something has finished,	600	Condition variables are very useful to signal that something has finished,
526	for example, if you write a module that does asynchronous http requests,	601	for example, if you write a module that does asynchronous http requests,
527	then a condition variable would be the ideal candidate to signal the	602	then a condition variable would be the ideal candidate to signal the
528	availability of results. The user can either act when the callback is	603	availability of results. The user can either act when the callback is
…		…
541		616
542	Condition variables are represented by hash refs in perl, and the keys	617	Condition variables are represented by hash refs in perl, and the keys
543	used by AnyEvent itself are all named C<_ae_XXX> to make subclassing	618	used by AnyEvent itself are all named C<_ae_XXX> to make subclassing
544	easy (it is often useful to build your own transaction class on top of	619	easy (it is often useful to build your own transaction class on top of
545	AnyEvent). To subclass, use C<AnyEvent::CondVar> as base class and call	620	AnyEvent). To subclass, use C<AnyEvent::CondVar> as base class and call
546	it's C<new> method in your own C<new> method.	621	its C<new> method in your own C<new> method.
547		622
548	There are two "sides" to a condition variable - the "producer side" which	623	There are two "sides" to a condition variable - the "producer side" which
549	eventually calls C<< -> send >>, and the "consumer side", which waits	624	eventually calls C<< -> send >>, and the "consumer side", which waits
550	for the send to occur.	625	for the send to occur.
551		626
552	Example: wait for a timer.	627	Example: wait for a timer.
553		628
554	# wait till the result is ready	629	# condition: "wait till the timer is fired"
555	my $result_ready = AnyEvent->condvar;	630	my $timer_fired = AnyEvent->condvar;
556		631
557	# do something such as adding a timer	632	# create the timer - we could wait for, say
558	# or socket watcher the calls $result_ready->send	633	# a handle becomign ready, or even an
559	# when the "result" is ready.	634	# AnyEvent::HTTP request to finish, but
560	# in this case, we simply use a timer:	635	# in this case, we simply use a timer:
561	my $w = AnyEvent->timer (	636	my $w = AnyEvent->timer (
562	after => 1,	637	after => 1,
563	cb => sub { $result_ready->send },	638	cb => sub { $timer_fired->send },
564	);	639	);
565		640
566	# this "blocks" (while handling events) till the callback	641	# this "blocks" (while handling events) till the callback
567	# calls -<send	642	# calls ->send
568	$result_ready->recv;	643	$timer_fired->recv;
569		644
570	Example: wait for a timer, but take advantage of the fact that condition	645	Example: wait for a timer, but take advantage of the fact that condition
571	variables are also callable directly.	646	variables are also callable directly.
572		647
573	my $done = AnyEvent->condvar;	648	my $done = AnyEvent->condvar;
…		…
616	they were a code reference). Calling them directly is the same as calling	691	they were a code reference). Calling them directly is the same as calling
617	C<send>.	692	C<send>.
618		693
619	=item $cv->croak ($error)	694	=item $cv->croak ($error)
620		695
621	Similar to send, but causes all call's to C<< ->recv >> to invoke	696	Similar to send, but causes all calls to C<< ->recv >> to invoke
622	C<Carp::croak> with the given error message/object/scalar.	697	C<Carp::croak> with the given error message/object/scalar.
623		698
624	This can be used to signal any errors to the condition variable	699	This can be used to signal any errors to the condition variable
625	user/consumer. Doing it this way instead of calling C<croak> directly	700	user/consumer. Doing it this way instead of calling C<croak> directly
626	delays the error detetcion, but has the overwhelmign advantage that it	701	delays the error detection, but has the overwhelming advantage that it
627	diagnoses the error at the place where the result is expected, and not	702	diagnoses the error at the place where the result is expected, and not
628	deep in some event clalback without connection to the actual code causing	703	deep in some event callback with no connection to the actual code causing
629	the problem.	704	the problem.
630		705
631	=item $cv->begin ([group callback])	706	=item $cv->begin ([group callback])
632		707
633	=item $cv->end	708	=item $cv->end
…		…
636	one. For example, a function that pings many hosts in parallel might want	711	one. For example, a function that pings many hosts in parallel might want
637	to use a condition variable for the whole process.	712	to use a condition variable for the whole process.
638		713
639	Every call to C<< ->begin >> will increment a counter, and every call to	714	Every call to C<< ->begin >> will increment a counter, and every call to
640	C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end	715	C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end
641	>>, the (last) callback passed to C<begin> will be executed. That callback	716	>>, the (last) callback passed to C<begin> will be executed, passing the
642	is I<supposed> to call C<< ->send >>, but that is not required. If no	717	condvar as first argument. That callback is I<supposed> to call C<< ->send
643	callback was set, C<send> will be called without any arguments.	718	>>, but that is not required. If no group callback was set, C<send> will
		719	be called without any arguments.
644		720
645	You can think of C<< $cv->send >> giving you an OR condition (one call	721	You can think of C<< $cv->send >> giving you an OR condition (one call
646	sends), while C<< $cv->begin >> and C<< $cv->end >> giving you an AND	722	sends), while C<< $cv->begin >> and C<< $cv->end >> giving you an AND
647	condition (all C<begin> calls must be C<end>'ed before the condvar sends).	723	condition (all C<begin> calls must be C<end>'ed before the condvar sends).
648		724
…		…
670	one call to C<begin>, so the condvar waits for all calls to C<end> before	746	one call to C<begin>, so the condvar waits for all calls to C<end> before
671	sending.	747	sending.
672		748
673	The ping example mentioned above is slightly more complicated, as the	749	The ping example mentioned above is slightly more complicated, as the
674	there are results to be passwd back, and the number of tasks that are	750	there are results to be passwd back, and the number of tasks that are
675	begung can potentially be zero:	751	begun can potentially be zero:
676		752
677	my $cv = AnyEvent->condvar;	753	my $cv = AnyEvent->condvar;
678		754
679	my %result;	755	my %result;
680	$cv->begin (sub { $cv->send (\%result) });	756	$cv->begin (sub { shift->send (\%result) });
681		757
682	for my $host (@list_of_hosts) {	758	for my $host (@list_of_hosts) {
683	$cv->begin;	759	$cv->begin;
684	ping_host_then_call_callback $host, sub {	760	ping_host_then_call_callback $host, sub {
685	$result{$host} = ...;	761	$result{$host} = ...;
…		…
701	to be called once the counter reaches C<0>, and second, it ensures that	777	to be called once the counter reaches C<0>, and second, it ensures that
702	C<send> is called even when C<no> hosts are being pinged (the loop	778	C<send> is called even when C<no> hosts are being pinged (the loop
703	doesn't execute once).	779	doesn't execute once).
704		780
705	This is the general pattern when you "fan out" into multiple (but	781	This is the general pattern when you "fan out" into multiple (but
706	potentially none) subrequests: use an outer C<begin>/C<end> pair to set	782	potentially zero) subrequests: use an outer C<begin>/C<end> pair to set
707	the callback and ensure C<end> is called at least once, and then, for each	783	the callback and ensure C<end> is called at least once, and then, for each
708	subrequest you start, call C<begin> and for each subrequest you finish,	784	subrequest you start, call C<begin> and for each subrequest you finish,
709	call C<end>.	785	call C<end>.
710		786
711	=back	787	=back
…		…
718	=over 4	794	=over 4
719		795
720	=item $cv->recv	796	=item $cv->recv
721		797
722	Wait (blocking if necessary) until the C<< ->send >> or C<< ->croak	798	Wait (blocking if necessary) until the C<< ->send >> or C<< ->croak
723	>> methods have been called on c<$cv>, while servicing other watchers	799	>> methods have been called on C<$cv>, while servicing other watchers
724	normally.	800	normally.
725		801
726	You can only wait once on a condition - additional calls are valid but	802	You can only wait once on a condition - additional calls are valid but
727	will return immediately.	803	will return immediately.
728		804
…		…
745	caller decide whether the call will block or not (for example, by coupling	821	caller decide whether the call will block or not (for example, by coupling
746	condition variables with some kind of request results and supporting	822	condition variables with some kind of request results and supporting
747	callbacks so the caller knows that getting the result will not block,	823	callbacks so the caller knows that getting the result will not block,
748	while still supporting blocking waits if the caller so desires).	824	while still supporting blocking waits if the caller so desires).
749		825
750	You can ensure that C<< -recv >> never blocks by setting a callback and	826	You can ensure that C<< ->recv >> never blocks by setting a callback and
751	only calling C<< ->recv >> from within that callback (or at a later	827	only calling C<< ->recv >> from within that callback (or at a later
752	time). This will work even when the event loop does not support blocking	828	time). This will work even when the event loop does not support blocking
753	waits otherwise.	829	waits otherwise.
754		830
755	=item $bool = $cv->ready	831	=item $bool = $cv->ready
…		…
761		837
762	This is a mutator function that returns the callback set and optionally	838	This is a mutator function that returns the callback set and optionally
763	replaces it before doing so.	839	replaces it before doing so.
764		840
765	The callback will be called when the condition becomes "true", i.e. when	841	The callback will be called when the condition becomes "true", i.e. when
766	C<send> or C<croak> are called, with the only argument being the condition	842	C<send> or C<croak> are called, with the only argument being the
767	variable itself. Calling C<recv> inside the callback or at any later time	843	condition variable itself. If the condition is already true, the
768	is guaranteed not to block.	844	callback is called immediately when it is set. Calling C<recv> inside
		845	the callback or at any later time is guaranteed not to block.
769		846
770	=back	847	=back
771		848
772	=head1 SUPPORTED EVENT LOOPS/BACKENDS	849	=head1 SUPPORTED EVENT LOOPS/BACKENDS
773		850
…		…
776	=over 4	853	=over 4
777		854
778	=item Backends that are autoprobed when no other event loop can be found.	855	=item Backends that are autoprobed when no other event loop can be found.
779		856
780	EV is the preferred backend when no other event loop seems to be in	857	EV is the preferred backend when no other event loop seems to be in
781	use. If EV is not installed, then AnyEvent will try Event, and, failing	858	use. If EV is not installed, then AnyEvent will fall back to its own
782	that, will fall back to its own pure-perl implementation, which is	859	pure-perl implementation, which is available everywhere as it comes with
783	available everywhere as it comes with AnyEvent itself.	860	AnyEvent itself.
784		861
785	AnyEvent::Impl::EV based on EV (interface to libev, best choice).	862	AnyEvent::Impl::EV based on EV (interface to libev, best choice).
786	AnyEvent::Impl::Event based on Event, very stable, few glitches.
787	AnyEvent::Impl::Perl pure-perl implementation, fast and portable.	863	AnyEvent::Impl::Perl pure-perl AnyEvent::Loop, fast and portable.
788		864
789	=item Backends that are transparently being picked up when they are used.	865	=item Backends that are transparently being picked up when they are used.
790		866
791	These will be used when they are currently loaded when the first watcher	867	These will be used if they are already loaded when the first watcher
792	is created, in which case it is assumed that the application is using	868	is created, in which case it is assumed that the application is using
793	them. This means that AnyEvent will automatically pick the right backend	869	them. This means that AnyEvent will automatically pick the right backend
794	when the main program loads an event module before anything starts to	870	when the main program loads an event module before anything starts to
795	create watchers. Nothing special needs to be done by the main program.	871	create watchers. Nothing special needs to be done by the main program.
796		872
		873	AnyEvent::Impl::Event based on Event, very stable, few glitches.
797	AnyEvent::Impl::Glib based on Glib, slow but very stable.	874	AnyEvent::Impl::Glib based on Glib, slow but very stable.
798	AnyEvent::Impl::Tk based on Tk, very broken.	875	AnyEvent::Impl::Tk based on Tk, very broken.
799	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.	876	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
800	AnyEvent::Impl::POE based on POE, very slow, some limitations.	877	AnyEvent::Impl::POE based on POE, very slow, some limitations.
		878	AnyEvent::Impl::Irssi used when running within irssi.
		879	AnyEvent::Impl::IOAsync based on IO::Async.
		880	AnyEvent::Impl::Cocoa based on Cocoa::EventLoop.
		881	AnyEvent::Impl::FLTK based on FLTK (fltk 2 binding).
801		882
802	=item Backends with special needs.	883	=item Backends with special needs.
803		884
804	Qt requires the Qt::Application to be instantiated first, but will	885	Qt requires the Qt::Application to be instantiated first, but will
805	otherwise be picked up automatically. As long as the main program	886	otherwise be picked up automatically. As long as the main program
806	instantiates the application before any AnyEvent watchers are created,	887	instantiates the application before any AnyEvent watchers are created,
807	everything should just work.	888	everything should just work.
808		889
809	AnyEvent::Impl::Qt based on Qt.	890	AnyEvent::Impl::Qt based on Qt.
810		891
811	Support for IO::Async can only be partial, as it is too broken and
812	architecturally limited to even support the AnyEvent API. It also
813	is the only event loop that needs the loop to be set explicitly, so
814	it can only be used by a main program knowing about AnyEvent. See
815	L<AnyEvent::Impl::Async> for the gory details.
816
817	AnyEvent::Impl::IOAsync based on IO::Async, cannot be autoprobed.
818
819	=item Event loops that are indirectly supported via other backends.	892	=item Event loops that are indirectly supported via other backends.
820		893
821	Some event loops can be supported via other modules:	894	Some event loops can be supported via other modules:
822		895
823	There is no direct support for WxWidgets (L<Wx>) or L<Prima>.	896	There is no direct support for WxWidgets (L<Wx>) or L<Prima>.
…		…
848	Contains C<undef> until the first watcher is being created, before the	921	Contains C<undef> until the first watcher is being created, before the
849	backend has been autodetected.	922	backend has been autodetected.
850		923
851	Afterwards it contains the event model that is being used, which is the	924	Afterwards it contains the event model that is being used, which is the
852	name of the Perl class implementing the model. This class is usually one	925	name of the Perl class implementing the model. This class is usually one
853	of the C<AnyEvent::Impl:xxx> modules, but can be any other class in the	926	of the C<AnyEvent::Impl::xxx> modules, but can be any other class in the
854	case AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode> it	927	case AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode> it
855	will be C<urxvt::anyevent>).	928	will be C<urxvt::anyevent>).
856		929
857	=item AnyEvent::detect	930	=item AnyEvent::detect
858		931
859	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model	932	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model
860	if necessary. You should only call this function right before you would	933	if necessary. You should only call this function right before you would
861	have created an AnyEvent watcher anyway, that is, as late as possible at	934	have created an AnyEvent watcher anyway, that is, as late as possible at
862	runtime, and not e.g. while initialising of your module.	935	runtime, and not e.g. during initialisation of your module.
		936
		937	The effect of calling this function is as if a watcher had been created
		938	(specifically, actions that happen "when the first watcher is created"
		939	happen when calling detetc as well).
863		940
864	If you need to do some initialisation before AnyEvent watchers are	941	If you need to do some initialisation before AnyEvent watchers are
865	created, use C<post_detect>.	942	created, use C<post_detect>.
866		943
867	=item $guard = AnyEvent::post_detect { BLOCK }	944	=item $guard = AnyEvent::post_detect { BLOCK }
868		945
869	Arranges for the code block to be executed as soon as the event model is	946	Arranges for the code block to be executed as soon as the event model is
870	autodetected (or immediately if this has already happened).	947	autodetected (or immediately if that has already happened).
871		948
872	The block will be executed I<after> the actual backend has been detected	949	The block will be executed I<after> the actual backend has been detected
873	(C<$AnyEvent::MODEL> is set), but I<before> any watchers have been	950	(C<$AnyEvent::MODEL> is set), but I<before> any watchers have been
874	created, so it is possible to e.g. patch C<@AnyEvent::ISA> or do	951	created, so it is possible to e.g. patch C<@AnyEvent::ISA> or do
875	other initialisations - see the sources of L<AnyEvent::Strict> or	952	other initialisations - see the sources of L<AnyEvent::Strict> or
…		…
879	event module detection too early, for example, L<AnyEvent::AIO> creates	956	event module detection too early, for example, L<AnyEvent::AIO> creates
880	and installs the global L<IO::AIO> watcher in a C<post_detect> block to	957	and installs the global L<IO::AIO> watcher in a C<post_detect> block to
881	avoid autodetecting the event module at load time.	958	avoid autodetecting the event module at load time.
882		959
883	If called in scalar or list context, then it creates and returns an object	960	If called in scalar or list context, then it creates and returns an object
884	that automatically removes the callback again when it is destroyed. See	961	that automatically removes the callback again when it is destroyed (or
		962	C<undef> when the hook was immediately executed). See L<AnyEvent::AIO> for
885	L<Coro::BDB> for a case where this is useful.	963	a case where this is useful.
		964
		965	Example: Create a watcher for the IO::AIO module and store it in
		966	C<$WATCHER>, but do so only do so after the event loop is initialised.
		967
		968	our WATCHER;
		969
		970	my $guard = AnyEvent::post_detect {
		971	$WATCHER = AnyEvent->io (fh => IO::AIO::poll_fileno, poll => 'r', cb => \&IO::AIO::poll_cb);
		972	};
		973
		974	# the ||= is important in case post_detect immediately runs the block,
		975	# as to not clobber the newly-created watcher. assigning both watcher and
		976	# post_detect guard to the same variable has the advantage of users being
		977	# able to just C<undef $WATCHER> if the watcher causes them grief.
		978
		979	$WATCHER ||= $guard;
886		980
887	=item @AnyEvent::post_detect	981	=item @AnyEvent::post_detect
888		982
889	If there are any code references in this array (you can C<push> to it	983	If there are any code references in this array (you can C<push> to it
890	before or after loading AnyEvent), then they will called directly after	984	before or after loading AnyEvent), then they will be called directly
891	the event loop has been chosen.	985	after the event loop has been chosen.
892		986
893	You should check C<$AnyEvent::MODEL> before adding to this array, though:	987	You should check C<$AnyEvent::MODEL> before adding to this array, though:
894	if it is defined then the event loop has already been detected, and the	988	if it is defined then the event loop has already been detected, and the
895	array will be ignored.	989	array will be ignored.
896		990
897	Best use C<AnyEvent::post_detect { BLOCK }> when your application allows	991	Best use C<AnyEvent::post_detect { BLOCK }> when your application allows
898	it,as it takes care of these details.	992	it, as it takes care of these details.
899		993
900	This variable is mainly useful for modules that can do something useful	994	This variable is mainly useful for modules that can do something useful
901	when AnyEvent is used and thus want to know when it is initialised, but do	995	when AnyEvent is used and thus want to know when it is initialised, but do
902	not need to even load it by default. This array provides the means to hook	996	not need to even load it by default. This array provides the means to hook
903	into AnyEvent passively, without loading it.	997	into AnyEvent passively, without loading it.
904		998
		999	Example: To load Coro::AnyEvent whenever Coro and AnyEvent are used
		1000	together, you could put this into Coro (this is the actual code used by
		1001	Coro to accomplish this):
		1002
		1003	if (defined $AnyEvent::MODEL) {
		1004	# AnyEvent already initialised, so load Coro::AnyEvent
		1005	require Coro::AnyEvent;
		1006	} else {
		1007	# AnyEvent not yet initialised, so make sure to load Coro::AnyEvent
		1008	# as soon as it is
		1009	push @AnyEvent::post_detect, sub { require Coro::AnyEvent };
		1010	}
		1011
		1012	=item AnyEvent::postpone { BLOCK }
		1013
		1014	Arranges for the block to be executed as soon as possible, but not before
		1015	the call itself returns. In practise, the block will be executed just
		1016	before the event loop polls for new events, or shortly afterwards.
		1017
		1018	This function never returns anything (to make the C<return postpone { ...
		1019	}> idiom more useful.
		1020
		1021	To understand the usefulness of this function, consider a function that
		1022	asynchronously does something for you and returns some transaction
		1023	object or guard to let you cancel the operation. For example,
		1024	C<AnyEvent::Socket::tcp_connect>:
		1025
		1026	# start a conenction attempt unless one is active
		1027	$self->{connect_guard} ||= AnyEvent::Socket::tcp_connect "www.example.net", 80, sub {
		1028	delete $self->{connect_guard};
		1029	...
		1030	};
		1031
		1032	Imagine that this function could instantly call the callback, for
		1033	example, because it detects an obvious error such as a negative port
		1034	number. Invoking the callback before the function returns causes problems
		1035	however: the callback will be called and will try to delete the guard
		1036	object. But since the function hasn't returned yet, there is nothing to
		1037	delete. When the function eventually returns it will assign the guard
		1038	object to C<< $self->{connect_guard} >>, where it will likely never be
		1039	deleted, so the program thinks it is still trying to connect.
		1040
		1041	This is where C<AnyEvent::postpone> should be used. Instead of calling the
		1042	callback directly on error:
		1043
		1044	$cb->(undef), return # signal error to callback, BAD!
		1045	if $some_error_condition;
		1046
		1047	It should use C<postpone>:
		1048
		1049	AnyEvent::postpone { $cb->(undef) }, return # signal error to callback, later
		1050	if $some_error_condition;
		1051
		1052	=item AnyEvent::log $level, $msg[, @args]
		1053
		1054	Log the given C<$msg> at the given C<$level>.
		1055
		1056	If L<AnyEvent::Log> is not loaded then this function makes a simple test
		1057	to see whether the message will be logged. If the test succeeds it will
		1058	load AnyEvent::Log and call C<AnyEvent::Log::log> - consequently, look at
		1059	the L<AnyEvent::Log> documentation for details.
		1060
		1061	If the test fails it will simply return. Right now this happens when a
		1062	numerical loglevel is used and it is larger than the level specified via
		1063	C<$ENV{PERL_ANYEVENT_VERBOSE}>.
		1064
		1065	If you want to sprinkle loads of logging calls around your code, consider
		1066	creating a logger callback with the C<AnyEvent::Log::logger> function,
		1067	which can reduce typing, codesize and can reduce the logging overhead
		1068	enourmously.
		1069
905	=back	1070	=back
906		1071
907	=head1 WHAT TO DO IN A MODULE	1072	=head1 WHAT TO DO IN A MODULE
908		1073
909	As a module author, you should C<use AnyEvent> and call AnyEvent methods	1074	As a module author, you should C<use AnyEvent> and call AnyEvent methods
…		…
919	because it will stall the whole program, and the whole point of using	1084	because it will stall the whole program, and the whole point of using
920	events is to stay interactive.	1085	events is to stay interactive.
921		1086
922	It is fine, however, to call C<< ->recv >> when the user of your module	1087	It is fine, however, to call C<< ->recv >> when the user of your module
923	requests it (i.e. if you create a http request object ad have a method	1088	requests it (i.e. if you create a http request object ad have a method
924	called C<results> that returns the results, it should call C<< ->recv >>	1089	called C<results> that returns the results, it may call C<< ->recv >>
925	freely, as the user of your module knows what she is doing. always).	1090	freely, as the user of your module knows what she is doing. Always).
926		1091
927	=head1 WHAT TO DO IN THE MAIN PROGRAM	1092	=head1 WHAT TO DO IN THE MAIN PROGRAM
928		1093
929	There will always be a single main program - the only place that should	1094	There will always be a single main program - the only place that should
930	dictate which event model to use.	1095	dictate which event model to use.
931		1096
932	If it doesn't care, it can just "use AnyEvent" and use it itself, or not	1097	If the program is not event-based, it need not do anything special, even
933	do anything special (it does not need to be event-based) and let AnyEvent	1098	when it depends on a module that uses an AnyEvent. If the program itself
934	decide which implementation to chose if some module relies on it.	1099	uses AnyEvent, but does not care which event loop is used, all it needs
		1100	to do is C<use AnyEvent>. In either case, AnyEvent will choose the best
		1101	available loop implementation.
935		1102
936	If the main program relies on a specific event model - for example, in	1103	If the main program relies on a specific event model - for example, in
937	Gtk2 programs you have to rely on the Glib module - you should load the	1104	Gtk2 programs you have to rely on the Glib module - you should load the
938	event module before loading AnyEvent or any module that uses it: generally	1105	event module before loading AnyEvent or any module that uses it: generally
939	speaking, you should load it as early as possible. The reason is that	1106	speaking, you should load it as early as possible. The reason is that
940	modules might create watchers when they are loaded, and AnyEvent will	1107	modules might create watchers when they are loaded, and AnyEvent will
941	decide on the event model to use as soon as it creates watchers, and it	1108	decide on the event model to use as soon as it creates watchers, and it
942	might chose the wrong one unless you load the correct one yourself.	1109	might choose the wrong one unless you load the correct one yourself.
943		1110
944	You can chose to use a pure-perl implementation by loading the	1111	You can chose to use a pure-perl implementation by loading the
945	C<AnyEvent::Impl::Perl> module, which gives you similar behaviour	1112	C<AnyEvent::Loop> module, which gives you similar behaviour
946	everywhere, but letting AnyEvent chose the model is generally better.	1113	everywhere, but letting AnyEvent chose the model is generally better.
947		1114
948	=head2 MAINLOOP EMULATION	1115	=head2 MAINLOOP EMULATION
949		1116
950	Sometimes (often for short test scripts, or even standalone programs who	1117	Sometimes (often for short test scripts, or even standalone programs who
…		…
963		1130
964		1131
965	=head1 OTHER MODULES	1132	=head1 OTHER MODULES
966		1133
967	The following is a non-exhaustive list of additional modules that use	1134	The following is a non-exhaustive list of additional modules that use
968	AnyEvent as a client and can therefore be mixed easily with other AnyEvent	1135	AnyEvent as a client and can therefore be mixed easily with other
969	modules and other event loops in the same program. Some of the modules	1136	AnyEvent modules and other event loops in the same program. Some of the
970	come with AnyEvent, most are available via CPAN.	1137	modules come as part of AnyEvent, the others are available via CPAN (see
		1138	L<http://search.cpan.org/search?m=module&q=anyevent%3A%3A*> for
		1139	a longer non-exhaustive list), and the list is heavily biased towards
		1140	modules of the AnyEvent author himself :)
971		1141
972	=over 4	1142	=over 4
973		1143
974	=item L<AnyEvent::Util>	1144	=item L<AnyEvent::Util>
975		1145
976	Contains various utility functions that replace often-used but blocking	1146	Contains various utility functions that replace often-used blocking
977	functions such as C<inet_aton> by event-/callback-based versions.	1147	functions such as C<inet_aton> with event/callback-based versions.
978		1148
979	=item L<AnyEvent::Socket>	1149	=item L<AnyEvent::Socket>
980		1150
981	Provides various utility functions for (internet protocol) sockets,	1151	Provides various utility functions for (internet protocol) sockets,
982	addresses and name resolution. Also functions to create non-blocking tcp	1152	addresses and name resolution. Also functions to create non-blocking tcp
…		…
984		1154
985	=item L<AnyEvent::Handle>	1155	=item L<AnyEvent::Handle>
986		1156
987	Provide read and write buffers, manages watchers for reads and writes,	1157	Provide read and write buffers, manages watchers for reads and writes,
988	supports raw and formatted I/O, I/O queued and fully transparent and	1158	supports raw and formatted I/O, I/O queued and fully transparent and
989	non-blocking SSL/TLS (via L<AnyEvent::TLS>.	1159	non-blocking SSL/TLS (via L<AnyEvent::TLS>).
990		1160
991	=item L<AnyEvent::DNS>	1161	=item L<AnyEvent::DNS>
992		1162
993	Provides rich asynchronous DNS resolver capabilities.	1163	Provides rich asynchronous DNS resolver capabilities.
994		1164
		1165	=item L<AnyEvent::HTTP>, L<AnyEvent::IRC>, L<AnyEvent::XMPP>, L<AnyEvent::GPSD>, L<AnyEvent::IGS>, L<AnyEvent::FCP>
		1166
		1167	Implement event-based interfaces to the protocols of the same name (for
		1168	the curious, IGS is the International Go Server and FCP is the Freenet
		1169	Client Protocol).
		1170
995	=item L<AnyEvent::HTTP>	1171	=item L<AnyEvent::AIO>
996		1172
997	A simple-to-use HTTP library that is capable of making a lot of concurrent	1173	Truly asynchronous (as opposed to non-blocking) I/O, should be in the
998	HTTP requests.	1174	toolbox of every event programmer. AnyEvent::AIO transparently fuses
		1175	L<IO::AIO> and AnyEvent together, giving AnyEvent access to event-based
		1176	file I/O, and much more.
		1177
		1178	=item L<AnyEvent::Filesys::Notify>
		1179
		1180	AnyEvent is good for non-blocking stuff, but it can't detect file or
		1181	path changes (e.g. "watch this directory for new files", "watch this
		1182	file for changes"). The L<AnyEvent::Filesys::Notify> module promises to
		1183	do just that in a portbale fashion, supporting inotify on GNU/Linux and
		1184	some weird, without doubt broken, stuff on OS X to monitor files. It can
		1185	fall back to blocking scans at regular intervals transparently on other
		1186	platforms, so it's about as portable as it gets.
		1187
		1188	(I haven't used it myself, but I haven't heard anybody complaining about
		1189	it yet).
		1190
		1191	=item L<AnyEvent::DBI>
		1192
		1193	Executes L<DBI> requests asynchronously in a proxy process for you,
		1194	notifying you in an event-based way when the operation is finished.
999		1195
1000	=item L<AnyEvent::HTTPD>	1196	=item L<AnyEvent::HTTPD>
1001		1197
1002	Provides a simple web application server framework.	1198	A simple embedded webserver.
1003		1199
1004	=item L<AnyEvent::FastPing>	1200	=item L<AnyEvent::FastPing>
1005		1201
1006	The fastest ping in the west.	1202	The fastest ping in the west.
1007		1203
1008	=item L<AnyEvent::DBI>
1009
1010	Executes L<DBI> requests asynchronously in a proxy process.
1011
1012	=item L<AnyEvent::AIO>
1013
1014	Truly asynchronous I/O, should be in the toolbox of every event
1015	programmer. AnyEvent::AIO transparently fuses L<IO::AIO> and AnyEvent
1016	together.
1017
1018	=item L<AnyEvent::BDB>
1019
1020	Truly asynchronous Berkeley DB access. AnyEvent::BDB transparently fuses
1021	L<BDB> and AnyEvent together.
1022
1023	=item L<AnyEvent::GPSD>
1024
1025	A non-blocking interface to gpsd, a daemon delivering GPS information.
1026
1027	=item L<AnyEvent::IRC>
1028
1029	AnyEvent based IRC client module family (replacing the older Net::IRC3).
1030
1031	=item L<AnyEvent::XMPP>
1032
1033	AnyEvent based XMPP (Jabber protocol) module family (replacing the older
1034	Net::XMPP2>.
1035
1036	=item L<AnyEvent::IGS>
1037
1038	A non-blocking interface to the Internet Go Server protocol (used by
1039	L<App::IGS>).
1040
1041	=item L<Net::FCP>
1042
1043	AnyEvent-based implementation of the Freenet Client Protocol, birthplace
1044	of AnyEvent.
1045
1046	=item L<Event::ExecFlow>
1047
1048	High level API for event-based execution flow control.
1049
1050	=item L<Coro>	1204	=item L<Coro>
1051		1205
1052	Has special support for AnyEvent via L<Coro::AnyEvent>.	1206	Has special support for AnyEvent via L<Coro::AnyEvent>, which allows you
		1207	to simply invert the flow control - don't call us, we will call you:
		1208
		1209	async {
		1210	Coro::AnyEvent::sleep 5; # creates a 5s timer and waits for it
		1211	print "5 seconds later!\n";
		1212
		1213	Coro::AnyEvent::readable *STDIN; # uses an I/O watcher
		1214	my $line = <STDIN>; # works for ttys
		1215
		1216	AnyEvent::HTTP::http_get "url", Coro::rouse_cb;
		1217	my ($body, $hdr) = Coro::rouse_wait;
		1218	};
1053		1219
1054	=back	1220	=back
1055		1221
1056	=cut	1222	=cut
1057		1223
1058	package AnyEvent;	1224	package AnyEvent;
1059		1225
1060	# basically a tuned-down version of common::sense	1226	# basically a tuned-down version of common::sense
1061	sub common_sense {	1227	sub common_sense {
1062	# no warnings	1228	# from common:.sense 3.5
1063	${^WARNING_BITS} ^= ${^WARNING_BITS};	1229	local $^W;
1064	# use strict vars subs	1230	${^WARNING_BITS} ^= ${^WARNING_BITS} ^ "\x3c\x3f\x33\x00\x0f\xf0\x0f\xc0\xf0\xfc\x33\x00";
		1231	# use strict vars subs - NO UTF-8, as Util.pm doesn't like this atm. (uts46data.pl)
1065	$^H |= 0x00000600;	1232	$^H |= 0x00000600;
1066	}	1233	}
1067		1234
1068	BEGIN { AnyEvent::common_sense }	1235	BEGIN { AnyEvent::common_sense }
1069		1236
1070	use Carp ();	1237	use Carp ();
1071		1238
1072	our $VERSION = 4.86;	1239	our $VERSION = '6.14';
1073	our $MODEL;	1240	our $MODEL;
1074
1075	our $AUTOLOAD;
1076	our @ISA;	1241	our @ISA;
1077
1078	our @REGISTRY;	1242	our @REGISTRY;
1079
1080	our $WIN32;
1081
1082	our $VERBOSE;	1243	our $VERBOSE;
		1244	our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred
		1245	our $MAX_SIGNAL_LATENCY = $ENV{PERL_ANYEVENT_MAX_SIGNAL_LATENCY} || 10; # executes after the BEGIN block below (tainting!)
1083		1246
1084	BEGIN {	1247	BEGIN {
1085	eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }";	1248	require "AnyEvent/constants.pl";
		1249
1086	eval "sub TAINT(){ " . (${^TAINT}*1) . " }";	1250	eval "sub TAINT (){" . (${^TAINT}*1) . "}";
1087		1251
1088	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}	1252	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}
1089	if ${^TAINT};	1253	if ${^TAINT};
1090		1254
1091	$VERBOSE = $ENV{PERL_ANYEVENT_VERBOSE}*1;	1255	$ENV{"PERL_ANYEVENT_$_"} = $ENV{"AE_$_"}
		1256	for grep s/^AE_// && !exists $ENV{"PERL_ANYEVENT_$_"}, keys %ENV;
1092		1257
1093	}	1258	@ENV{grep /^PERL_ANYEVENT_/, keys %ENV} = ()
		1259	if ${^TAINT};
1094		1260
1095	our $MAX_SIGNAL_LATENCY = 10;	1261	# $ENV{PERL_ANYEVENT_xxx} now valid
1096		1262
1097	our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred	1263	$VERBOSE = length $ENV{PERL_ANYEVENT_VERBOSE} ? $ENV{PERL_ANYEVENT_VERBOSE}*1 : 4;
1098		1264
1099	{
1100	my $idx;	1265	my $idx;
1101	$PROTOCOL{$_} = ++$idx	1266	$PROTOCOL{$_} = ++$idx
1102	for reverse split /\s*,\s*/,	1267	for reverse split /\s*,\s*/,
1103	$ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";	1268	$ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";
1104	}	1269	}
1105		1270
		1271	our @post_detect;
		1272
		1273	sub post_detect(&) {
		1274	my ($cb) = @_;
		1275
		1276	push @post_detect, $cb;
		1277
		1278	defined wantarray
		1279	? bless \$cb, "AnyEvent::Util::postdetect"
		1280	: ()
		1281	}
		1282
		1283	sub AnyEvent::Util::postdetect::DESTROY {
		1284	@post_detect = grep $_ != ${$_[0]}, @post_detect;
		1285	}
		1286
		1287	our $POSTPONE_W;
		1288	our @POSTPONE;
		1289
		1290	sub _postpone_exec {
		1291	undef $POSTPONE_W;
		1292
		1293	&{ shift @POSTPONE }
		1294	while @POSTPONE;
		1295	}
		1296
		1297	sub postpone(&) {
		1298	push @POSTPONE, shift;
		1299
		1300	$POSTPONE_W ||= AE::timer (0, 0, \&_postpone_exec);
		1301
		1302	()
		1303	}
		1304
		1305	sub log($$;@) {
		1306	# only load the big bloated module when we actually are about to log something
		1307	if ($_[0] <= ($VERBOSE || 1)) { # also catches non-numeric levels(!) and fatal
		1308	local ($!, $@);
		1309	require AnyEvent::Log; # among other things, sets $VERBOSE to 9
		1310	# AnyEvent::Log overwrites this function
		1311	goto &log;
		1312	}
		1313
		1314	0 # not logged
		1315	}
		1316
		1317	sub _logger($;$) {
		1318	my ($level, $renabled) = @_;
		1319
		1320	$$renabled = $level <= $VERBOSE;
		1321
		1322	my $logger = [(caller)[0], $level, $renabled];
		1323
		1324	$AnyEvent::Log::LOGGER{$logger+0} = $logger;
		1325
		1326	# return unless defined wantarray;
		1327	#
		1328	# require AnyEvent::Util;
		1329	# my $guard = AnyEvent::Util::guard (sub {
		1330	# # "clean up"
		1331	# delete $LOGGER{$logger+0};
		1332	# });
		1333	#
		1334	# sub {
		1335	# return 0 unless $$renabled;
		1336	#
		1337	# $guard if 0; # keep guard alive, but don't cause runtime overhead
		1338	# require AnyEvent::Log unless $AnyEvent::Log::VERSION;
		1339	# package AnyEvent::Log;
		1340	# _log ($logger->[0], $level, @_) # logger->[0] has been converted at load time
		1341	# }
		1342	}
		1343
		1344	if (length $ENV{PERL_ANYEVENT_LOG}) {
		1345	require AnyEvent::Log; # AnyEvent::Log does the thing for us
		1346	}
		1347
1106	my @models = (	1348	our @models = (
1107	[EV:: => AnyEvent::Impl::EV::],	1349	[EV:: => AnyEvent::Impl::EV::],
1108	[Event:: => AnyEvent::Impl::Event::],
1109	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::],	1350	[AnyEvent::Loop:: => AnyEvent::Impl::Perl::],
1110	# everything below here will not be autoprobed	1351	# everything below here will not (normally) be autoprobed
1111	# as the pureperl backend should work everywhere	1352	# as the pure perl backend should work everywhere
1112	# and is usually faster	1353	# and is usually faster
		1354	[Irssi:: => AnyEvent::Impl::Irssi::], # Irssi has a bogus "Event" package, so msut be near the top
		1355	[Event:: => AnyEvent::Impl::Event::], # slow, stable
1113	[Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers	1356	[Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers
		1357	# everything below here should not be autoloaded
1114	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy	1358	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
1115	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles	1359	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
1116	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program	1360	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program
1117	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza	1361	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
1118	[Wx:: => AnyEvent::Impl::POE::],	1362	[Wx:: => AnyEvent::Impl::POE::],
1119	[Prima:: => AnyEvent::Impl::POE::],	1363	[Prima:: => AnyEvent::Impl::POE::],
1120	# IO::Async is just too broken - we would need workarounds for its	1364	[IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # a bitch to autodetect
1121	# byzantine signal and broken child handling, among others.	1365	[Cocoa::EventLoop:: => AnyEvent::Impl::Cocoa::],
1122	# IO::Async is rather hard to detect, as it doesn't have any	1366	[FLTK:: => AnyEvent::Impl::FLTK::],
1123	# obvious default class.
1124	# [IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program
1125	# [IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program
1126	# [IO::Async::Notifier:: => AnyEvent::Impl::IOAsync::], # requires special main program
1127	);	1367	);
1128		1368
1129	our %method = map +($_ => 1),	1369	our @isa_hook;
		1370
		1371	sub _isa_set {
		1372	my @pkg = ("AnyEvent", (map $_->[0], grep defined, @isa_hook), $MODEL);
		1373
		1374	@{"$pkg[$_-1]::ISA"} = $pkg[$_]
		1375	for 1 .. $#pkg;
		1376
		1377	grep $_ && $_->[1], @isa_hook
		1378	and AE::_reset ();
		1379	}
		1380
		1381	# used for hooking AnyEvent::Strict and AnyEvent::Debug::Wrap into the class hierarchy
		1382	sub _isa_hook($$;$) {
		1383	my ($i, $pkg, $reset_ae) = @_;
		1384
		1385	$isa_hook[$i] = $pkg ? [$pkg, $reset_ae] : undef;
		1386
		1387	_isa_set;
		1388	}
		1389
		1390	# all autoloaded methods reserve the complete glob, not just the method slot.
		1391	# due to bugs in perls method cache implementation.
1130	qw(io timer time now now_update signal child idle condvar one_event DESTROY);	1392	our @methods = qw(io timer time now now_update signal child idle condvar);
1131		1393
1132	our @post_detect;
1133
1134	sub post_detect(&) {	1394	sub detect() {
1135	my ($cb) = @_;	1395	return $MODEL if $MODEL; # some programs keep references to detect
1136		1396
1137	if ($MODEL) {	1397	# IO::Async::Loop::AnyEvent is extremely evil, refuse to work with it
1138	$cb->();	1398	# the author knows about the problems and what it does to AnyEvent as a whole
		1399	# (and the ability of others to use AnyEvent), but simply wants to abuse AnyEvent
		1400	# anyway.
		1401	AnyEvent::log fatal => "AnyEvent: IO::Async::Loop::AnyEvent detected - that module is broken by\n"
		1402	. "design, abuses internals and breaks AnyEvent - will not continue."
		1403	if exists $INC{"IO/Async/Loop/AnyEvent.pm"};
1139		1404
1140	1	1405	local $!; # for good measure
		1406	local $SIG{__DIE__}; # we use eval
		1407
		1408	# free some memory
		1409	*detect = sub () { $MODEL };
		1410	# undef &func doesn't correctly update the method cache. grmbl.
		1411	# so we delete the whole glob. grmbl.
		1412	# otoh, perl doesn't let me undef an active usb, but it lets me free
		1413	# a glob with an active sub. hrm. i hope it works, but perl is
		1414	# usually buggy in this department. sigh.
		1415	delete @{"AnyEvent::"}{@methods};
		1416	undef @methods;
		1417
		1418	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z0-9:]+)$/) {
		1419	my $model = $1;
		1420	$model = "AnyEvent::Impl::$model" unless $model =~ s/::$//;
		1421	if (eval "require $model") {
		1422	AnyEvent::log 7 => "loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.";
		1423	$MODEL = $model;
1141	} else {	1424	} else {
1142	push @post_detect, $cb;	1425	AnyEvent::log 4 => "unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@";
1143		1426	}
1144	defined wantarray
1145	? bless \$cb, "AnyEvent::Util::postdetect"
1146	: ()
1147	}	1427	}
1148	}
1149		1428
1150	sub AnyEvent::Util::postdetect::DESTROY {	1429	# check for already loaded models
1151	@post_detect = grep $_ != ${$_[0]}, @post_detect;
1152	}
1153
1154	sub detect() {
1155	unless ($MODEL) {	1430	unless ($MODEL) {
1156	local $SIG{__DIE__};	1431	for (@REGISTRY, @models) {
1157		1432	my ($package, $model) = @$_;
1158	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {	1433	if (${"$package\::VERSION"} > 0) {
1159	my $model = "AnyEvent::Impl::$1";
1160	if (eval "require $model") {	1434	if (eval "require $model") {
		1435	AnyEvent::log 7 => "autodetected model '$model', using it.";
1161	$MODEL = $model;	1436	$MODEL = $model;
1162	warn "AnyEvent: loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.\n" if $VERBOSE >= 2;	1437	last;
1163	} else {	1438	} else {
1164	warn "AnyEvent: unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@" if $VERBOSE;	1439	AnyEvent::log 8 => "detected event loop $package, but cannot load '$model', skipping: $@";
		1440	}
1165	}	1441	}
1166	}	1442	}
1167		1443
1168	# check for already loaded models
1169	unless ($MODEL) {	1444	unless ($MODEL) {
		1445	# try to autoload a model
1170	for (@REGISTRY, @models) {	1446	for (@REGISTRY, @models) {
1171	my ($package, $model) = @$_;	1447	my ($package, $model) = @$_;
		1448	if (
		1449	eval "require $package"
1172	if (${"$package\::VERSION"} > 0) {	1450	and ${"$package\::VERSION"} > 0
1173	if (eval "require $model") {	1451	and eval "require $model"
		1452	) {
		1453	AnyEvent::log 7 => "autoloaded model '$model', using it.";
1174	$MODEL = $model;	1454	$MODEL = $model;
1175	warn "AnyEvent: autodetected model '$model', using it.\n" if $VERBOSE >= 2;
1176	last;	1455	last;
1177	}
1178	}	1456	}
1179	}	1457	}
1180		1458
1181	unless ($MODEL) {
1182	# try to load a model
1183
1184	for (@REGISTRY, @models) {
1185	my ($package, $model) = @$_;
1186	if (eval "require $package"
1187	and ${"$package\::VERSION"} > 0
1188	and eval "require $model") {
1189	$MODEL = $model;
1190	warn "AnyEvent: autoprobed model '$model', using it.\n" if $VERBOSE >= 2;
1191	last;
1192	}
1193	}
1194
1195	$MODEL	1459	$MODEL
1196	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.\n";	1460	or AnyEvent::log fatal => "AnyEvent: backend autodetection failed - did you properly install AnyEvent?";
1197	}
1198	}	1461	}
1199
1200	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
1201
1202	unshift @ISA, $MODEL;
1203
1204	require AnyEvent::Strict if $ENV{PERL_ANYEVENT_STRICT};
1205
1206	(shift @post_detect)->() while @post_detect;
1207	}	1462	}
1208		1463
		1464	# free memory only needed for probing
		1465	undef @models;
		1466	undef @REGISTRY;
		1467
		1468	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
		1469
		1470	# now nuke some methods that are overridden by the backend.
		1471	# SUPER usage is not allowed in these.
		1472	for (qw(time signal child idle)) {
		1473	undef &{"AnyEvent::Base::$_"}
		1474	if defined &{"$MODEL\::$_"};
		1475	}
		1476
		1477	_isa_set;
		1478
		1479	# we're officially open!
		1480
		1481	if ($ENV{PERL_ANYEVENT_STRICT}) {
		1482	require AnyEvent::Strict;
		1483	}
		1484
		1485	if ($ENV{PERL_ANYEVENT_DEBUG_WRAP}) {
		1486	require AnyEvent::Debug;
		1487	AnyEvent::Debug::wrap ($ENV{PERL_ANYEVENT_DEBUG_WRAP});
		1488	}
		1489
		1490	if (length $ENV{PERL_ANYEVENT_DEBUG_SHELL}) {
		1491	require AnyEvent::Socket;
		1492	require AnyEvent::Debug;
		1493
		1494	my $shell = $ENV{PERL_ANYEVENT_DEBUG_SHELL};
		1495	$shell =~ s/\$\$/$$/g;
		1496
		1497	my ($host, $service) = AnyEvent::Socket::parse_hostport ($shell);
		1498	$AnyEvent::Debug::SHELL = AnyEvent::Debug::shell ($host, $service);
		1499	}
		1500
		1501	# now the anyevent environment is set up as the user told us to, so
		1502	# call the actual user code - post detects
		1503
		1504	(shift @post_detect)->() while @post_detect;
		1505	undef @post_detect;
		1506
		1507	*post_detect = sub(&) {
		1508	shift->();
		1509
		1510	undef
		1511	};
		1512
1209	$MODEL	1513	$MODEL
1210	}	1514	}
1211		1515
1212	sub AUTOLOAD {	1516	for my $name (@methods) {
1213	(my $func = $AUTOLOAD) =~ s/.*://;	1517	*$name = sub {
1214		1518	detect;
1215	$method{$func}	1519	# we use goto because
1216	or Carp::croak "$func: not a valid method for AnyEvent objects";	1520	# a) it makes the thunk more transparent
1217		1521	# b) it allows us to delete the thunk later
1218	detect unless $MODEL;	1522	goto &{ UNIVERSAL::can AnyEvent => "SUPER::$name" }
1219		1523	};
1220	my $class = shift;
1221	$class->$func (@_);
1222	}	1524	}
1223		1525
1224	# utility function to dup a filehandle. this is used by many backends	1526	# utility function to dup a filehandle. this is used by many backends
1225	# to support binding more than one watcher per filehandle (they usually	1527	# to support binding more than one watcher per filehandle (they usually
1226	# allow only one watcher per fd, so we dup it to get a different one).	1528	# allow only one watcher per fd, so we dup it to get a different one).
…		…
1236	# we assume CLOEXEC is already set by perl in all important cases	1538	# we assume CLOEXEC is already set by perl in all important cases
1237		1539
1238	($fh2, $rw)	1540	($fh2, $rw)
1239	}	1541	}
1240		1542
		1543	=head1 SIMPLIFIED AE API
		1544
		1545	Starting with version 5.0, AnyEvent officially supports a second, much
		1546	simpler, API that is designed to reduce the calling, typing and memory
		1547	overhead by using function call syntax and a fixed number of parameters.
		1548
		1549	See the L<AE> manpage for details.
		1550
		1551	=cut
		1552
		1553	package AE;
		1554
		1555	our $VERSION = $AnyEvent::VERSION;
		1556
		1557	sub _reset() {
		1558	eval q{
		1559	# fall back to the main API by default - backends and AnyEvent::Base
		1560	# implementations can overwrite these.
		1561
		1562	sub io($$$) {
		1563	AnyEvent->io (fh => $_[0], poll => $_[1] ? "w" : "r", cb => $_[2])
		1564	}
		1565
		1566	sub timer($$$) {
		1567	AnyEvent->timer (after => $_[0], interval => $_[1], cb => $_[2])
		1568	}
		1569
		1570	sub signal($$) {
		1571	AnyEvent->signal (signal => $_[0], cb => $_[1])
		1572	}
		1573
		1574	sub child($$) {
		1575	AnyEvent->child (pid => $_[0], cb => $_[1])
		1576	}
		1577
		1578	sub idle($) {
		1579	AnyEvent->idle (cb => $_[0]);
		1580	}
		1581
		1582	sub cv(;&) {
		1583	AnyEvent->condvar (@_ ? (cb => $_[0]) : ())
		1584	}
		1585
		1586	sub now() {
		1587	AnyEvent->now
		1588	}
		1589
		1590	sub now_update() {
		1591	AnyEvent->now_update
		1592	}
		1593
		1594	sub time() {
		1595	AnyEvent->time
		1596	}
		1597
		1598	*postpone = \&AnyEvent::postpone;
		1599	*log = \&AnyEvent::log;
		1600	};
		1601	die if $@;
		1602	}
		1603
		1604	BEGIN { _reset }
		1605
1241	package AnyEvent::Base;	1606	package AnyEvent::Base;
1242		1607
1243	# default implementations for many methods	1608	# default implementations for many methods
1244		1609
1245	sub _time {	1610	sub time {
		1611	eval q{ # poor man's autoloading {}
1246	# probe for availability of Time::HiRes	1612	# probe for availability of Time::HiRes
1247	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {	1613	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {
1248	warn "AnyEvent: using Time::HiRes for sub-second timing accuracy.\n" if $VERBOSE >= 8;	1614	*time = sub { Time::HiRes::time () };
1249	*_time = \&Time::HiRes::time;	1615	*AE::time = \& Time::HiRes::time ;
		1616	*now = \&time;
		1617	AnyEvent::log 8 => "AnyEvent: using Time::HiRes for sub-second timing accuracy.";
1250	# if (eval "use POSIX (); (POSIX::times())...	1618	# if (eval "use POSIX (); (POSIX::times())...
1251	} else {	1619	} else {
		1620	*time = sub { CORE::time };
		1621	*AE::time = sub (){ CORE::time };
		1622	*now = \&time;
1252	warn "AnyEvent: using built-in time(), WARNING, no sub-second resolution!\n" if $VERBOSE;	1623	AnyEvent::log 3 => "using built-in time(), WARNING, no sub-second resolution!";
1253	*_time = sub { time }; # epic fail	1624	}
1254	}	1625	};
		1626	die if $@;
1255		1627
1256	&_time	1628	&time
1257	}	1629	}
1258		1630
1259	sub time { _time }	1631	*now = \&time;
1260	sub now { _time }
1261	sub now_update { }	1632	sub now_update { }
1262		1633
		1634	sub _poll {
		1635	Carp::croak "$AnyEvent::MODEL does not support blocking waits. Caught";
		1636	}
		1637
1263	# default implementation for ->condvar	1638	# default implementation for ->condvar
		1639	# in fact, the default should not be overwritten
1264		1640
1265	sub condvar {	1641	sub condvar {
		1642	eval q{ # poor man's autoloading {}
		1643	*condvar = sub {
1266	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"	1644	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"
		1645	};
		1646
		1647	*AE::cv = sub (;&) {
		1648	bless { @_ ? (_ae_cb => shift) : () }, "AnyEvent::CondVar"
		1649	};
		1650	};
		1651	die if $@;
		1652
		1653	&condvar
1267	}	1654	}
1268		1655
1269	# default implementation for ->signal	1656	# default implementation for ->signal
1270		1657
1271	our $HAVE_ASYNC_INTERRUPT;	1658	our $HAVE_ASYNC_INTERRUPT;
		1659
		1660	sub _have_async_interrupt() {
		1661	$HAVE_ASYNC_INTERRUPT = 1*(!$ENV{PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT}
		1662	&& eval "use Async::Interrupt 1.02 (); 1")
		1663	unless defined $HAVE_ASYNC_INTERRUPT;
		1664
		1665	$HAVE_ASYNC_INTERRUPT
		1666	}
		1667
1272	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);	1668	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);
1273	our (%SIG_ASY, %SIG_ASY_W);	1669	our (%SIG_ASY, %SIG_ASY_W);
1274	our ($SIG_COUNT, $SIG_TW);	1670	our ($SIG_COUNT, $SIG_TW);
1275		1671
1276	sub _signal_exec {
1277	$HAVE_ASYNC_INTERRUPT
1278	? $SIGPIPE_R->drain
1279	: sysread $SIGPIPE_R, my $dummy, 9;
1280
1281	while (%SIG_EV) {
1282	for (keys %SIG_EV) {
1283	delete $SIG_EV{$_};
1284	$_->() for values %{ $SIG_CB{$_} || {} };
1285	}
1286	}
1287	}
1288
1289	# install a dumym wakeupw atcher to reduce signal catching latency	1672	# install a dummy wakeup watcher to reduce signal catching latency
		1673	# used by Impls
1290	sub _sig_add() {	1674	sub _sig_add() {
1291	unless ($SIG_COUNT++) {	1675	unless ($SIG_COUNT++) {
1292	# try to align timer on a full-second boundary, if possible	1676	# try to align timer on a full-second boundary, if possible
1293	my $NOW = AnyEvent->now;	1677	my $NOW = AE::now;
1294		1678
1295	$SIG_TW = AnyEvent->timer (	1679	$SIG_TW = AE::timer
1296	after => $MAX_SIGNAL_LATENCY - ($NOW - int $NOW),	1680	$MAX_SIGNAL_LATENCY - ($NOW - int $NOW),
1297	interval => $MAX_SIGNAL_LATENCY,	1681	$MAX_SIGNAL_LATENCY,
1298	cb => sub { }, # just for the PERL_ASYNC_CHECK	1682	sub { } # just for the PERL_ASYNC_CHECK
1299	);	1683	;
1300	}	1684	}
1301	}	1685	}
1302		1686
1303	sub _sig_del {	1687	sub _sig_del {
1304	undef $SIG_TW	1688	undef $SIG_TW
1305	unless --$SIG_COUNT;	1689	unless --$SIG_COUNT;
1306	}	1690	}
1307		1691
		1692	our $_sig_name_init; $_sig_name_init = sub {
		1693	eval q{ # poor man's autoloading {}
		1694	undef $_sig_name_init;
		1695
		1696	if (_have_async_interrupt) {
		1697	*sig2num = \&Async::Interrupt::sig2num;
		1698	*sig2name = \&Async::Interrupt::sig2name;
		1699	} else {
		1700	require Config;
		1701
		1702	my %signame2num;
		1703	@signame2num{ split ' ', $Config::Config{sig_name} }
		1704	= split ' ', $Config::Config{sig_num};
		1705
		1706	my @signum2name;
		1707	@signum2name[values %signame2num] = keys %signame2num;
		1708
		1709	*sig2num = sub($) {
		1710	$_[0] > 0 ? shift : $signame2num{+shift}
		1711	};
		1712	*sig2name = sub ($) {
		1713	$_[0] > 0 ? $signum2name[+shift] : shift
		1714	};
		1715	}
		1716	};
		1717	die if $@;
		1718	};
		1719
		1720	sub sig2num ($) { &$_sig_name_init; &sig2num }
		1721	sub sig2name($) { &$_sig_name_init; &sig2name }
		1722
1308	sub _signal {	1723	sub signal {
1309	my (undef, %arg) = @_;	1724	eval q{ # poor man's autoloading {}
		1725	# probe for availability of Async::Interrupt
		1726	if (_have_async_interrupt) {
		1727	AnyEvent::log 8 => "using Async::Interrupt for race-free signal handling.";
1310		1728
1311	my $signal = uc $arg{signal}	1729	$SIGPIPE_R = new Async::Interrupt::EventPipe;
1312	or Carp::croak "required option 'signal' is missing";	1730	$SIG_IO = AE::io $SIGPIPE_R->fileno, 0, \&_signal_exec;
1313		1731
1314	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};	1732	} else {
		1733	AnyEvent::log 8 => "using emulated perl signal handling with latency timer.";
1315		1734
1316	if ($HAVE_ASYNC_INTERRUPT) {	1735	if (AnyEvent::WIN32) {
1317	# async::interrupt	1736	require AnyEvent::Util;
1318		1737
1319	$SIG_ASY{$signal} ||= do {	1738	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
1320	my $asy = new Async::Interrupt	1739	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R, 1) if $SIGPIPE_R;
1321	cb => sub { undef $SIG_EV{$signal} },	1740	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W, 1) if $SIGPIPE_W; # just in case
1322	signal => $signal,	1741	} else {
1323	pipe => [$SIGPIPE_R->filenos],	1742	pipe $SIGPIPE_R, $SIGPIPE_W;
		1743	fcntl $SIGPIPE_R, AnyEvent::F_SETFL, AnyEvent::O_NONBLOCK if $SIGPIPE_R;
		1744	fcntl $SIGPIPE_W, AnyEvent::F_SETFL, AnyEvent::O_NONBLOCK if $SIGPIPE_W; # just in case
		1745
		1746	# not strictly required, as $^F is normally 2, but let's make sure...
		1747	fcntl $SIGPIPE_R, AnyEvent::F_SETFD, AnyEvent::FD_CLOEXEC;
		1748	fcntl $SIGPIPE_W, AnyEvent::F_SETFD, AnyEvent::FD_CLOEXEC;
1324	;	1749	}
1325	$asy->pipe_autodrain (0);
1326		1750
1327	$asy	1751	$SIGPIPE_R
		1752	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";
		1753
		1754	$SIG_IO = AE::io $SIGPIPE_R, 0, \&_signal_exec;
		1755	}
		1756
		1757	*signal = $HAVE_ASYNC_INTERRUPT
		1758	? sub {
		1759	my (undef, %arg) = @_;
		1760
		1761	# async::interrupt
		1762	my $signal = sig2num $arg{signal};
		1763	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
		1764
		1765	$SIG_ASY{$signal} ||= new Async::Interrupt
		1766	cb => sub { undef $SIG_EV{$signal} },
		1767	signal => $signal,
		1768	pipe => [$SIGPIPE_R->filenos],
		1769	pipe_autodrain => 0,
		1770	;
		1771
		1772	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
		1773	}
		1774	: sub {
		1775	my (undef, %arg) = @_;
		1776
		1777	# pure perl
		1778	my $signal = sig2name $arg{signal};
		1779	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
		1780
		1781	$SIG{$signal} ||= sub {
		1782	local $!;
		1783	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;
		1784	undef $SIG_EV{$signal};
		1785	};
		1786
		1787	# can't do signal processing without introducing races in pure perl,
		1788	# so limit the signal latency.
		1789	_sig_add;
		1790
		1791	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
		1792	}
		1793	;
		1794
		1795	*AnyEvent::Base::signal::DESTROY = sub {
		1796	my ($signal, $cb) = @{$_[0]};
		1797
		1798	_sig_del;
		1799
		1800	delete $SIG_CB{$signal}{$cb};
		1801
		1802	$HAVE_ASYNC_INTERRUPT
		1803	? delete $SIG_ASY{$signal}
		1804	: # delete doesn't work with older perls - they then
		1805	# print weird messages, or just unconditionally exit
		1806	# instead of getting the default action.
		1807	undef $SIG{$signal}
		1808	unless keys %{ $SIG_CB{$signal} };
1328	};	1809	};
1329		1810
1330	} else {	1811	*_signal_exec = sub {
1331	# pure perl	1812	$HAVE_ASYNC_INTERRUPT
		1813	? $SIGPIPE_R->drain
		1814	: sysread $SIGPIPE_R, (my $dummy), 9;
1332		1815
1333	$SIG{$signal} ||= sub {	1816	while (%SIG_EV) {
1334	local $!;	1817	for (keys %SIG_EV) {
1335	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;	1818	delete $SIG_EV{$_};
1336	undef $SIG_EV{$signal};	1819	&$_ for values %{ $SIG_CB{$_} || {} };
		1820	}
		1821	}
1337	};	1822	};
1338
1339	# can't do signal processing without introducing races in pure perl,
1340	# so limit the signal latency.
1341	_sig_add;
1342	}	1823	};
		1824	die if $@;
1343		1825
1344	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
1345	}
1346
1347	sub signal {
1348	# probe for availability of Async::Interrupt
1349	if (!$ENV{PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT} && eval "use Async::Interrupt 0.6 (); 1") {
1350	warn "AnyEvent: using Async::Interrupt for race-free signal handling.\n" if $VERBOSE >= 8;
1351
1352	$HAVE_ASYNC_INTERRUPT = 1;
1353	$SIGPIPE_R = new Async::Interrupt::EventPipe;
1354	$SIG_IO = AnyEvent->io (fh => $SIGPIPE_R->fileno, poll => "r", cb => \&_signal_exec);
1355
1356	} else {
1357	warn "AnyEvent: using emulated perl signal handling with latency timer.\n" if $VERBOSE >= 8;
1358
1359	require Fcntl;
1360
1361	if (AnyEvent::WIN32) {
1362	require AnyEvent::Util;
1363
1364	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
1365	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R) if $SIGPIPE_R;
1366	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W) if $SIGPIPE_W; # just in case
1367	} else {
1368	pipe $SIGPIPE_R, $SIGPIPE_W;
1369	fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R;
1370	fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case
1371
1372	# not strictly required, as $^F is normally 2, but let's make sure...
1373	fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
1374	fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
1375	}
1376
1377	$SIGPIPE_R
1378	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";
1379
1380	$SIG_IO = AnyEvent->io (fh => $SIGPIPE_R, poll => "r", cb => \&_signal_exec);
1381	}
1382
1383	*signal = \&_signal;
1384	&signal	1826	&signal
1385	}
1386
1387	sub AnyEvent::Base::signal::DESTROY {
1388	my ($signal, $cb) = @{$_[0]};
1389
1390	_sig_del;
1391
1392	delete $SIG_CB{$signal}{$cb};
1393
1394	$HAVE_ASYNC_INTERRUPT
1395	? delete $SIG_ASY{$signal}
1396	: # delete doesn't work with older perls - they then
1397	# print weird messages, or just unconditionally exit
1398	# instead of getting the default action.
1399	undef $SIG{$signal}
1400	unless keys %{ $SIG_CB{$signal} };
1401	}	1827	}
1402		1828
1403	# default implementation for ->child	1829	# default implementation for ->child
1404		1830
1405	our %PID_CB;	1831	our %PID_CB;
1406	our $CHLD_W;	1832	our $CHLD_W;
1407	our $CHLD_DELAY_W;	1833	our $CHLD_DELAY_W;
1408	our $WNOHANG;
1409		1834
1410	sub _sigchld {	1835	# used by many Impl's
1411	while (0 < (my $pid = waitpid -1, $WNOHANG)) {	1836	sub _emit_childstatus($$) {
1412	$_->($pid, $?)	1837	my (undef, $rpid, $rstatus) = @_;
		1838
		1839	$_->($rpid, $rstatus)
1413	for values %{ $PID_CB{$pid} || {} },	1840	for values %{ $PID_CB{$rpid} || {} },
1414	values %{ $PID_CB{0} || {} };	1841	values %{ $PID_CB{0} || {} };
1415	}
1416	}	1842	}
1417		1843
1418	sub child {	1844	sub child {
		1845	eval q{ # poor man's autoloading {}
		1846	*_sigchld = sub {
		1847	my $pid;
		1848
		1849	AnyEvent->_emit_childstatus ($pid, $?)
		1850	while ($pid = waitpid -1, WNOHANG) > 0;
		1851	};
		1852
		1853	*child = sub {
1419	my (undef, %arg) = @_;	1854	my (undef, %arg) = @_;
1420		1855
1421	defined (my $pid = $arg{pid} + 0)	1856	my $pid = $arg{pid};
1422	or Carp::croak "required option 'pid' is missing";	1857	my $cb = $arg{cb};
1423		1858
1424	$PID_CB{$pid}{$arg{cb}} = $arg{cb};	1859	$PID_CB{$pid}{$cb+0} = $cb;
1425		1860
1426	# WNOHANG is almost cetrainly 1 everywhere
1427	$WNOHANG ||= $^O =~ /^(?:openbsd|netbsd|linux|freebsd|cygwin|MSWin32)$/
1428	? 1
1429	: eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1;
1430
1431	unless ($CHLD_W) {	1861	unless ($CHLD_W) {
1432	$CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld);	1862	$CHLD_W = AE::signal CHLD => \&_sigchld;
1433	# child could be a zombie already, so make at least one round	1863	# child could be a zombie already, so make at least one round
1434	&_sigchld;	1864	&_sigchld;
1435	}	1865	}
1436		1866
1437	bless [$pid, $arg{cb}], "AnyEvent::Base::child"	1867	bless [$pid, $cb+0], "AnyEvent::Base::child"
1438	}	1868	};
1439		1869
1440	sub AnyEvent::Base::child::DESTROY {	1870	*AnyEvent::Base::child::DESTROY = sub {
1441	my ($pid, $cb) = @{$_[0]};	1871	my ($pid, $icb) = @{$_[0]};
1442		1872
1443	delete $PID_CB{$pid}{$cb};	1873	delete $PID_CB{$pid}{$icb};
1444	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };	1874	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };
1445		1875
1446	undef $CHLD_W unless keys %PID_CB;	1876	undef $CHLD_W unless keys %PID_CB;
		1877	};
		1878	};
		1879	die if $@;
		1880
		1881	&child
1447	}	1882	}
1448		1883
1449	# idle emulation is done by simply using a timer, regardless	1884	# idle emulation is done by simply using a timer, regardless
1450	# of whether the process is idle or not, and not letting	1885	# of whether the process is idle or not, and not letting
1451	# the callback use more than 50% of the time.	1886	# the callback use more than 50% of the time.
1452	sub idle {	1887	sub idle {
		1888	eval q{ # poor man's autoloading {}
		1889	*idle = sub {
1453	my (undef, %arg) = @_;	1890	my (undef, %arg) = @_;
1454		1891
1455	my ($cb, $w, $rcb) = $arg{cb};	1892	my ($cb, $w, $rcb) = $arg{cb};
1456		1893
1457	$rcb = sub {	1894	$rcb = sub {
1458	if ($cb) {	1895	if ($cb) {
1459	$w = _time;	1896	$w = AE::time;
1460	&$cb;	1897	&$cb;
1461	$w = _time - $w;	1898	$w = AE::time - $w;
1462		1899
1463	# never use more then 50% of the time for the idle watcher,	1900	# never use more then 50% of the time for the idle watcher,
1464	# within some limits	1901	# within some limits
1465	$w = 0.0001 if $w < 0.0001;	1902	$w = 0.0001 if $w < 0.0001;
1466	$w = 5 if $w > 5;	1903	$w = 5 if $w > 5;
1467		1904
1468	$w = AnyEvent->timer (after => $w, cb => $rcb);	1905	$w = AE::timer $w, 0, $rcb;
1469	} else {	1906	} else {
1470	# clean up...	1907	# clean up...
1471	undef $w;	1908	undef $w;
1472	undef $rcb;	1909	undef $rcb;
		1910	}
		1911	};
		1912
		1913	$w = AE::timer 0.05, 0, $rcb;
		1914
		1915	bless \\$cb, "AnyEvent::Base::idle"
1473	}	1916	};
		1917
		1918	*AnyEvent::Base::idle::DESTROY = sub {
		1919	undef $${$_[0]};
		1920	};
1474	};	1921	};
		1922	die if $@;
1475		1923
1476	$w = AnyEvent->timer (after => 0.05, cb => $rcb);	1924	&idle
1477
1478	bless \\$cb, "AnyEvent::Base::idle"
1479	}
1480
1481	sub AnyEvent::Base::idle::DESTROY {
1482	undef $${$_[0]};
1483	}	1925	}
1484		1926
1485	package AnyEvent::CondVar;	1927	package AnyEvent::CondVar;
1486		1928
1487	our @ISA = AnyEvent::CondVar::Base::;	1929	our @ISA = AnyEvent::CondVar::Base::;
		1930
		1931	# only to be used for subclassing
		1932	sub new {
		1933	my $class = shift;
		1934	bless AnyEvent->condvar (@_), $class
		1935	}
1488		1936
1489	package AnyEvent::CondVar::Base;	1937	package AnyEvent::CondVar::Base;
1490		1938
1491	#use overload	1939	#use overload
1492	# '&{}' => sub { my $self = shift; sub { $self->send (@_) } },	1940	# '&{}' => sub { my $self = shift; sub { $self->send (@_) } },
…		…
1502		1950
1503	sub _send {	1951	sub _send {
1504	# nop	1952	# nop
1505	}	1953	}
1506		1954
		1955	sub _wait {
		1956	AnyEvent->_poll until $_[0]{_ae_sent};
		1957	}
		1958
1507	sub send {	1959	sub send {
1508	my $cv = shift;	1960	my $cv = shift;
1509	$cv->{_ae_sent} = [@_];	1961	$cv->{_ae_sent} = [@_];
1510	(delete $cv->{_ae_cb})->($cv) if $cv->{_ae_cb};	1962	(delete $cv->{_ae_cb})->($cv) if $cv->{_ae_cb};
1511	$cv->_send;	1963	$cv->_send;
…		…
1518		1970
1519	sub ready {	1971	sub ready {
1520	$_[0]{_ae_sent}	1972	$_[0]{_ae_sent}
1521	}	1973	}
1522		1974
1523	sub _wait {
1524	$WAITING
1525	and !$_[0]{_ae_sent}
1526	and Carp::croak "AnyEvent::CondVar: recursive blocking wait detected";
1527
1528	local $WAITING = 1;
1529	AnyEvent->one_event while !$_[0]{_ae_sent};
1530	}
1531
1532	sub recv {	1975	sub recv {
		1976	unless ($_[0]{_ae_sent}) {
		1977	$WAITING
		1978	and Carp::croak "AnyEvent::CondVar: recursive blocking wait attempted";
		1979
		1980	local $WAITING = 1;
1533	$_[0]->_wait;	1981	$_[0]->_wait;
		1982	}
1534		1983
1535	Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak};	1984	$_[0]{_ae_croak}
1536	wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0]	1985	and Carp::croak $_[0]{_ae_croak};
		1986
		1987	wantarray
		1988	? @{ $_[0]{_ae_sent} }
		1989	: $_[0]{_ae_sent}[0]
1537	}	1990	}
1538		1991
1539	sub cb {	1992	sub cb {
1540	$_[0]{_ae_cb} = $_[1] if @_ > 1;	1993	my $cv = shift;
		1994
		1995	@_
		1996	and $cv->{_ae_cb} = shift
		1997	and $cv->{_ae_sent}
		1998	and (delete $cv->{_ae_cb})->($cv);
		1999
1541	$_[0]{_ae_cb}	2000	$cv->{_ae_cb}
1542	}	2001	}
1543		2002
1544	sub begin {	2003	sub begin {
1545	++$_[0]{_ae_counter};	2004	++$_[0]{_ae_counter};
1546	$_[0]{_ae_end_cb} = $_[1] if @_ > 1;	2005	$_[0]{_ae_end_cb} = $_[1] if @_ > 1;
…		…
1551	&{ $_[0]{_ae_end_cb} || sub { $_[0]->send } };	2010	&{ $_[0]{_ae_end_cb} || sub { $_[0]->send } };
1552	}	2011	}
1553		2012
1554	# undocumented/compatibility with pre-3.4	2013	# undocumented/compatibility with pre-3.4
1555	*broadcast = \&send;	2014	*broadcast = \&send;
1556	*wait = \&_wait;	2015	*wait = \&recv;
1557		2016
1558	=head1 ERROR AND EXCEPTION HANDLING	2017	=head1 ERROR AND EXCEPTION HANDLING
1559		2018
1560	In general, AnyEvent does not do any error handling - it relies on the	2019	In general, AnyEvent does not do any error handling - it relies on the
1561	caller to do that if required. The L<AnyEvent::Strict> module (see also	2020	caller to do that if required. The L<AnyEvent::Strict> module (see also
…		…
1573	$Event/EV::DIED->() >>, L<Glib> uses C<< install_exception_handler >> and	2032	$Event/EV::DIED->() >>, L<Glib> uses C<< install_exception_handler >> and
1574	so on.	2033	so on.
1575		2034
1576	=head1 ENVIRONMENT VARIABLES	2035	=head1 ENVIRONMENT VARIABLES
1577		2036
1578	The following environment variables are used by this module or its	2037	AnyEvent supports a number of environment variables that tune the
1579	submodules.	2038	runtime behaviour. They are usually evaluated when AnyEvent is
		2039	loaded, initialised, or a submodule that uses them is loaded. Many of
		2040	them also cause AnyEvent to load additional modules - for example,
		2041	C<PERL_ANYEVENT_DEBUG_WRAP> causes the L<AnyEvent::Debug> module to be
		2042	loaded.
1580		2043
1581	Note that AnyEvent will remove I<all> environment variables starting with	2044	All the environment variables documented here start with
1582	C<PERL_ANYEVENT_> from C<%ENV> when it is loaded while taint mode is	2045	C<PERL_ANYEVENT_>, which is what AnyEvent considers its own
1583	enabled.	2046	namespace. Other modules are encouraged (but by no means required) to use
		2047	C<PERL_ANYEVENT_SUBMODULE> if they have registered the AnyEvent::Submodule
		2048	namespace on CPAN, for any submodule. For example, L<AnyEvent::HTTP> could
		2049	be expected to use C<PERL_ANYEVENT_HTTP_PROXY> (it should not access env
		2050	variables starting with C<AE_>, see below).
		2051
		2052	All variables can also be set via the C<AE_> prefix, that is, instead
		2053	of setting C<PERL_ANYEVENT_VERBOSE> you can also set C<AE_VERBOSE>. In
		2054	case there is a clash btween anyevent and another program that uses
		2055	C<AE_something> you can set the corresponding C<PERL_ANYEVENT_something>
		2056	variable to the empty string, as those variables take precedence.
		2057
		2058	When AnyEvent is first loaded, it copies all C<AE_xxx> env variables
		2059	to their C<PERL_ANYEVENT_xxx> counterpart unless that variable already
		2060	exists. If taint mode is on, then AnyEvent will remove I<all> environment
		2061	variables starting with C<PERL_ANYEVENT_> from C<%ENV> (or replace them
		2062	with C<undef> or the empty string, if the corresaponding C<AE_> variable
		2063	is set).
		2064
		2065	The exact algorithm is currently:
		2066
		2067	1. if taint mode enabled, delete all PERL_ANYEVENT_xyz variables from %ENV
		2068	2. copy over AE_xyz to PERL_ANYEVENT_xyz unless the latter alraedy exists
		2069	3. if taint mode enabled, set all PERL_ANYEVENT_xyz variables to undef.
		2070
		2071	This ensures that child processes will not see the C<AE_> variables.
		2072
		2073	The following environment variables are currently known to AnyEvent:
1584		2074
1585	=over 4	2075	=over 4
1586		2076
1587	=item C<PERL_ANYEVENT_VERBOSE>	2077	=item C<PERL_ANYEVENT_VERBOSE>
1588		2078
1589	By default, AnyEvent will be completely silent except in fatal	2079	By default, AnyEvent will log messages with loglevel C<4> (C<error>) or
1590	conditions. You can set this environment variable to make AnyEvent more	2080	higher (see L<AnyEvent::Log>). You can set this environment variable to a
1591	talkative.	2081	numerical loglevel to make AnyEvent more (or less) talkative.
1592		2082
		2083	If you want to do more than just set the global logging level
		2084	you should have a look at C<PERL_ANYEVENT_LOG>, which allows much more
		2085	complex specifications.
		2086
		2087	When set to C<0> (C<off>), then no messages whatsoever will be logged with
		2088	everything else at defaults.
		2089
1593	When set to C<1> or higher, causes AnyEvent to warn about unexpected	2090	When set to C<5> or higher (C<warn>), AnyEvent warns about unexpected
1594	conditions, such as not being able to load the event model specified by	2091	conditions, such as not being able to load the event model specified by
1595	C<PERL_ANYEVENT_MODEL>.	2092	C<PERL_ANYEVENT_MODEL>, or a guard callback throwing an exception - this
		2093	is the minimum recommended level for use during development.
1596		2094
1597	When set to C<2> or higher, cause AnyEvent to report to STDERR which event	2095	When set to C<7> or higher (info), AnyEvent reports which event model it
1598	model it chooses.	2096	chooses.
1599		2097
1600	When set to C<8> or higher, then AnyEvent will report extra information on	2098	When set to C<8> or higher (debug), then AnyEvent will report extra
1601	which optional modules it loads and how it implements certain features.	2099	information on which optional modules it loads and how it implements
		2100	certain features.
		2101
		2102	=item C<PERL_ANYEVENT_LOG>
		2103
		2104	Accepts rather complex logging specifications. For example, you could log
		2105	all C<debug> messages of some module to stderr, warnings and above to
		2106	stderr, and errors and above to syslog, with:
		2107
		2108	PERL_ANYEVENT_LOG=Some::Module=debug,+log:filter=warn,+%syslog:%syslog=error,syslog
		2109
		2110	For the rather extensive details, see L<AnyEvent::Log>.
		2111
		2112	This variable is evaluated when AnyEvent (or L<AnyEvent::Log>) is loaded,
		2113	so will take effect even before AnyEvent has initialised itself.
		2114
		2115	Note that specifying this environment variable causes the L<AnyEvent::Log>
		2116	module to be loaded, while C<PERL_ANYEVENT_VERBOSE> does not, so only
		2117	using the latter saves a few hundred kB of memory unless a module
		2118	explicitly needs the extra features of AnyEvent::Log.
1602		2119
1603	=item C<PERL_ANYEVENT_STRICT>	2120	=item C<PERL_ANYEVENT_STRICT>
1604		2121
1605	AnyEvent does not do much argument checking by default, as thorough	2122	AnyEvent does not do much argument checking by default, as thorough
1606	argument checking is very costly. Setting this variable to a true value	2123	argument checking is very costly. Setting this variable to a true value
…		…
1608	check the arguments passed to most method calls. If it finds any problems,	2125	check the arguments passed to most method calls. If it finds any problems,
1609	it will croak.	2126	it will croak.
1610		2127
1611	In other words, enables "strict" mode.	2128	In other words, enables "strict" mode.
1612		2129
1613	Unlike C<use strict> (or it's modern cousin, C<< use L<common::sense>	2130	Unlike C<use strict> (or its modern cousin, C<< use L<common::sense>
1614	>>, it is definitely recommended to keep it off in production. Keeping	2131	>>, it is definitely recommended to keep it off in production. Keeping
1615	C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs	2132	C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs
1616	can be very useful, however.	2133	can be very useful, however.
1617		2134
		2135	=item C<PERL_ANYEVENT_DEBUG_SHELL>
		2136
		2137	If this env variable is nonempty, then its contents will be interpreted by
		2138	C<AnyEvent::Socket::parse_hostport> and C<AnyEvent::Debug::shell> (after
		2139	replacing every occurance of C<$$> by the process pid). The shell object
		2140	is saved in C<$AnyEvent::Debug::SHELL>.
		2141
		2142	This happens when the first watcher is created.
		2143
		2144	For example, to bind a debug shell on a unix domain socket in
		2145	F<< /tmp/debug<pid>.sock >>, you could use this:
		2146
		2147	PERL_ANYEVENT_DEBUG_SHELL=/tmp/debug\$\$.sock perlprog
		2148	# connect with e.g.: socat readline /tmp/debug123.sock
		2149
		2150	Or to bind to tcp port 4545 on localhost:
		2151
		2152	PERL_ANYEVENT_DEBUG_SHELL=127.0.0.1:4545 perlprog
		2153	# connect with e.g.: telnet localhost 4545
		2154
		2155	Note that creating sockets in F</tmp> or on localhost is very unsafe on
		2156	multiuser systems.
		2157
		2158	=item C<PERL_ANYEVENT_DEBUG_WRAP>
		2159
		2160	Can be set to C<0>, C<1> or C<2> and enables wrapping of all watchers for
		2161	debugging purposes. See C<AnyEvent::Debug::wrap> for details.
		2162
1618	=item C<PERL_ANYEVENT_MODEL>	2163	=item C<PERL_ANYEVENT_MODEL>
1619		2164
1620	This can be used to specify the event model to be used by AnyEvent, before	2165	This can be used to specify the event model to be used by AnyEvent, before
1621	auto detection and -probing kicks in. It must be a string consisting	2166	auto detection and -probing kicks in.
1622	entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended	2167
		2168	It normally is a string consisting entirely of ASCII letters (e.g. C<EV>
		2169	or C<IOAsync>). The string C<AnyEvent::Impl::> gets prepended and the
1623	and the resulting module name is loaded and if the load was successful,	2170	resulting module name is loaded and - if the load was successful - used as
1624	used as event model. If it fails to load AnyEvent will proceed with	2171	event model backend. If it fails to load then AnyEvent will proceed with
1625	auto detection and -probing.	2172	auto detection and -probing.
1626		2173
1627	This functionality might change in future versions.	2174	If the string ends with C<::> instead (e.g. C<AnyEvent::Impl::EV::>) then
		2175	nothing gets prepended and the module name is used as-is (hint: C<::> at
		2176	the end of a string designates a module name and quotes it appropriately).
1628		2177
1629	For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you	2178	For example, to force the pure perl model (L<AnyEvent::Loop::Perl>) you
1630	could start your program like this:	2179	could start your program like this:
1631		2180
1632	PERL_ANYEVENT_MODEL=Perl perl ...	2181	PERL_ANYEVENT_MODEL=Perl perl ...
1633		2182
1634	=item C<PERL_ANYEVENT_PROTOCOLS>	2183	=item C<PERL_ANYEVENT_PROTOCOLS>
…		…
1650	but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4>	2199	but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4>
1651	- only support IPv4, never try to resolve or contact IPv6	2200	- only support IPv4, never try to resolve or contact IPv6
1652	addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or	2201	addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or
1653	IPv6, but prefer IPv6 over IPv4.	2202	IPv6, but prefer IPv6 over IPv4.
1654		2203
		2204	=item C<PERL_ANYEVENT_HOSTS>
		2205
		2206	This variable, if specified, overrides the F</etc/hosts> file used by
		2207	L<AnyEvent::Socket>C<::resolve_sockaddr>, i.e. hosts aliases will be read
		2208	from that file instead.
		2209
1655	=item C<PERL_ANYEVENT_EDNS0>	2210	=item C<PERL_ANYEVENT_EDNS0>
1656		2211
1657	Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension	2212	Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension for
1658	for DNS. This extension is generally useful to reduce DNS traffic, but	2213	DNS. This extension is generally useful to reduce DNS traffic, especially
1659	some (broken) firewalls drop such DNS packets, which is why it is off by	2214	when DNSSEC is involved, but some (broken) firewalls drop such DNS
1660	default.	2215	packets, which is why it is off by default.
1661		2216
1662	Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce	2217	Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce
1663	EDNS0 in its DNS requests.	2218	EDNS0 in its DNS requests.
1664		2219
1665	=item C<PERL_ANYEVENT_MAX_FORKS>	2220	=item C<PERL_ANYEVENT_MAX_FORKS>
…		…
1671		2226
1672	The default value for the C<max_outstanding> parameter for the default DNS	2227	The default value for the C<max_outstanding> parameter for the default DNS
1673	resolver - this is the maximum number of parallel DNS requests that are	2228	resolver - this is the maximum number of parallel DNS requests that are
1674	sent to the DNS server.	2229	sent to the DNS server.
1675		2230
		2231	=item C<PERL_ANYEVENT_MAX_SIGNAL_LATENCY>
		2232
		2233	Perl has inherently racy signal handling (you can basically choose between
		2234	losing signals and memory corruption) - pure perl event loops (including
		2235	C<AnyEvent::Loop>, when C<Async::Interrupt> isn't available) therefore
		2236	have to poll regularly to avoid losing signals.
		2237
		2238	Some event loops are racy, but don't poll regularly, and some event loops
		2239	are written in C but are still racy. For those event loops, AnyEvent
		2240	installs a timer that regularly wakes up the event loop.
		2241
		2242	By default, the interval for this timer is C<10> seconds, but you can
		2243	override this delay with this environment variable (or by setting
		2244	the C<$AnyEvent::MAX_SIGNAL_LATENCY> variable before creating signal
		2245	watchers).
		2246
		2247	Lower values increase CPU (and energy) usage, higher values can introduce
		2248	long delays when reaping children or waiting for signals.
		2249
		2250	The L<AnyEvent::Async> module, if available, will be used to avoid this
		2251	polling (with most event loops).
		2252
1676	=item C<PERL_ANYEVENT_RESOLV_CONF>	2253	=item C<PERL_ANYEVENT_RESOLV_CONF>
1677		2254
1678	The file to use instead of F</etc/resolv.conf> (or OS-specific	2255	The absolute path to a F<resolv.conf>-style file to use instead of
1679	configuration) in the default resolver. When set to the empty string, no	2256	F</etc/resolv.conf> (or the OS-specific configuration) in the default
1680	default config will be used.	2257	resolver, or the empty string to select the default configuration.
1681		2258
1682	=item C<PERL_ANYEVENT_CA_FILE>, C<PERL_ANYEVENT_CA_PATH>.	2259	=item C<PERL_ANYEVENT_CA_FILE>, C<PERL_ANYEVENT_CA_PATH>.
1683		2260
1684	When neither C<ca_file> nor C<ca_path> was specified during	2261	When neither C<ca_file> nor C<ca_path> was specified during
1685	L<AnyEvent::TLS> context creation, and either of these environment	2262	L<AnyEvent::TLS> context creation, and either of these environment
1686	variables exist, they will be used to specify CA certificate locations	2263	variables are nonempty, they will be used to specify CA certificate
1687	instead of a system-dependent default.	2264	locations instead of a system-dependent default.
1688		2265
1689	=item C<PERL_ANYEVENT_AVOID_GUARD> and C<PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT>	2266	=item C<PERL_ANYEVENT_AVOID_GUARD> and C<PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT>
1690		2267
1691	When these are set to C<1>, then the respective modules are not	2268	When these are set to C<1>, then the respective modules are not
1692	loaded. Mostly good for testing AnyEvent itself.	2269	loaded. Mostly good for testing AnyEvent itself.
…		…
1755	warn "read: $input\n"; # output what has been read	2332	warn "read: $input\n"; # output what has been read
1756	$cv->send if $input =~ /^q/i; # quit program if /^q/i	2333	$cv->send if $input =~ /^q/i; # quit program if /^q/i
1757	},	2334	},
1758	);	2335	);
1759		2336
1760	my $time_watcher; # can only be used once
1761
1762	sub new_timer {
1763	$timer = AnyEvent->timer (after => 1, cb => sub {	2337	my $time_watcher = AnyEvent->timer (after => 1, interval => 1, cb => sub {
1764	warn "timeout\n"; # print 'timeout' about every second	2338	warn "timeout\n"; # print 'timeout' at most every second
1765	&new_timer; # and restart the time
1766	});	2339	});
1767	}
1768
1769	new_timer; # create first timer
1770		2340
1771	$cv->recv; # wait until user enters /^q/i	2341	$cv->recv; # wait until user enters /^q/i
1772		2342
1773	=head1 REAL-WORLD EXAMPLE	2343	=head1 REAL-WORLD EXAMPLE
1774		2344
…		…
1847		2417
1848	The actual code goes further and collects all errors (C<die>s, exceptions)	2418	The actual code goes further and collects all errors (C<die>s, exceptions)
1849	that occurred during request processing. The C<result> method detects	2419	that occurred during request processing. The C<result> method detects
1850	whether an exception as thrown (it is stored inside the $txn object)	2420	whether an exception as thrown (it is stored inside the $txn object)
1851	and just throws the exception, which means connection errors and other	2421	and just throws the exception, which means connection errors and other
1852	problems get reported tot he code that tries to use the result, not in a	2422	problems get reported to the code that tries to use the result, not in a
1853	random callback.	2423	random callback.
1854		2424
1855	All of this enables the following usage styles:	2425	All of this enables the following usage styles:
1856		2426
1857	1. Blocking:	2427	1. Blocking:
…		…
1905	through AnyEvent. The benchmark creates a lot of timers (with a zero	2475	through AnyEvent. The benchmark creates a lot of timers (with a zero
1906	timeout) and I/O watchers (watching STDOUT, a pty, to become writable,	2476	timeout) and I/O watchers (watching STDOUT, a pty, to become writable,
1907	which it is), lets them fire exactly once and destroys them again.	2477	which it is), lets them fire exactly once and destroys them again.
1908		2478
1909	Source code for this benchmark is found as F<eg/bench> in the AnyEvent	2479	Source code for this benchmark is found as F<eg/bench> in the AnyEvent
1910	distribution.	2480	distribution. It uses the L<AE> interface, which makes a real difference
		2481	for the EV and Perl backends only.
1911		2482
1912	=head3 Explanation of the columns	2483	=head3 Explanation of the columns
1913		2484
1914	I<watcher> is the number of event watchers created/destroyed. Since	2485	I<watcher> is the number of event watchers created/destroyed. Since
1915	different event models feature vastly different performances, each event	2486	different event models feature vastly different performances, each event
…		…
1936	watcher.	2507	watcher.
1937		2508
1938	=head3 Results	2509	=head3 Results
1939		2510
1940	name watchers bytes create invoke destroy comment	2511	name watchers bytes create invoke destroy comment
1941	EV/EV 400000 224 0.47 0.35 0.27 EV native interface	2512	EV/EV 100000 223 0.47 0.43 0.27 EV native interface
1942	EV/Any 100000 224 2.88 0.34 0.27 EV + AnyEvent watchers	2513	EV/Any 100000 223 0.48 0.42 0.26 EV + AnyEvent watchers
1943	CoroEV/Any 100000 224 2.85 0.35 0.28 coroutines + Coro::Signal	2514	Coro::EV/Any 100000 223 0.47 0.42 0.26 coroutines + Coro::Signal
1944	Perl/Any 100000 452 4.13 0.73 0.95 pure perl implementation	2515	Perl/Any 100000 431 2.70 0.74 0.92 pure perl implementation
1945	Event/Event 16000 517 32.20 31.80 0.81 Event native interface	2516	Event/Event 16000 516 31.16 31.84 0.82 Event native interface
1946	Event/Any 16000 590 35.85 31.55 1.06 Event + AnyEvent watchers	2517	Event/Any 16000 1203 42.61 34.79 1.80 Event + AnyEvent watchers
1947	IOAsync/Any 16000 989 38.10 32.77 11.13 via IO::Async::Loop::IO_Poll	2518	IOAsync/Any 16000 1911 41.92 27.45 16.81 via IO::Async::Loop::IO_Poll
1948	IOAsync/Any 16000 990 37.59 29.50 10.61 via IO::Async::Loop::Epoll	2519	IOAsync/Any 16000 1726 40.69 26.37 15.25 via IO::Async::Loop::Epoll
1949	Glib/Any 16000 1357 102.33 12.31 51.00 quadratic behaviour	2520	Glib/Any 16000 1118 89.00 12.57 51.17 quadratic behaviour
1950	Tk/Any 2000 1860 27.20 66.31 14.00 SEGV with >> 2000 watchers	2521	Tk/Any 2000 1346 20.96 10.75 8.00 SEGV with >> 2000 watchers
1951	POE/Event 2000 6328 109.99 751.67 14.02 via POE::Loop::Event	2522	POE/Any 2000 6951 108.97 795.32 14.24 via POE::Loop::Event
1952	POE/Select 2000 6027 94.54 809.13 579.80 via POE::Loop::Select	2523	POE/Any 2000 6648 94.79 774.40 575.51 via POE::Loop::Select
1953		2524
1954	=head3 Discussion	2525	=head3 Discussion
1955		2526
1956	The benchmark does I<not> measure scalability of the event loop very	2527	The benchmark does I<not> measure scalability of the event loop very
1957	well. For example, a select-based event loop (such as the pure perl one)	2528	well. For example, a select-based event loop (such as the pure perl one)
…		…
1969	benchmark machine, handling an event takes roughly 1600 CPU cycles with	2540	benchmark machine, handling an event takes roughly 1600 CPU cycles with
1970	EV, 3100 CPU cycles with AnyEvent's pure perl loop and almost 3000000 CPU	2541	EV, 3100 CPU cycles with AnyEvent's pure perl loop and almost 3000000 CPU
1971	cycles with POE.	2542	cycles with POE.
1972		2543
1973	C<EV> is the sole leader regarding speed and memory use, which are both	2544	C<EV> is the sole leader regarding speed and memory use, which are both
1974	maximal/minimal, respectively. Even when going through AnyEvent, it uses	2545	maximal/minimal, respectively. When using the L<AE> API there is zero
		2546	overhead (when going through the AnyEvent API create is about 5-6 times
		2547	slower, with other times being equal, so still uses far less memory than
1975	far less memory than any other event loop and is still faster than Event	2548	any other event loop and is still faster than Event natively).
1976	natively.
1977		2549
1978	The pure perl implementation is hit in a few sweet spots (both the	2550	The pure perl implementation is hit in a few sweet spots (both the
1979	constant timeout and the use of a single fd hit optimisations in the perl	2551	constant timeout and the use of a single fd hit optimisations in the perl
1980	interpreter and the backend itself). Nevertheless this shows that it	2552	interpreter and the backend itself). Nevertheless this shows that it
1981	adds very little overhead in itself. Like any select-based backend its	2553	adds very little overhead in itself. Like any select-based backend its
…		…
2029	(even when used without AnyEvent), but most event loops have acceptable	2601	(even when used without AnyEvent), but most event loops have acceptable
2030	performance with or without AnyEvent.	2602	performance with or without AnyEvent.
2031		2603
2032	=item * The overhead AnyEvent adds is usually much smaller than the overhead of	2604	=item * The overhead AnyEvent adds is usually much smaller than the overhead of
2033	the actual event loop, only with extremely fast event loops such as EV	2605	the actual event loop, only with extremely fast event loops such as EV
2034	adds AnyEvent significant overhead.	2606	does AnyEvent add significant overhead.
2035		2607
2036	=item * You should avoid POE like the plague if you want performance or	2608	=item * You should avoid POE like the plague if you want performance or
2037	reasonable memory usage.	2609	reasonable memory usage.
2038		2610
2039	=back	2611	=back
…		…
2055	In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100	2627	In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100
2056	(1%) are active. This mirrors the activity of large servers with many	2628	(1%) are active. This mirrors the activity of large servers with many
2057	connections, most of which are idle at any one point in time.	2629	connections, most of which are idle at any one point in time.
2058		2630
2059	Source code for this benchmark is found as F<eg/bench2> in the AnyEvent	2631	Source code for this benchmark is found as F<eg/bench2> in the AnyEvent
2060	distribution.	2632	distribution. It uses the L<AE> interface, which makes a real difference
		2633	for the EV and Perl backends only.
2061		2634
2062	=head3 Explanation of the columns	2635	=head3 Explanation of the columns
2063		2636
2064	I<sockets> is the number of sockets, and twice the number of "servers" (as	2637	I<sockets> is the number of sockets, and twice the number of "servers" (as
2065	each server has a read and write socket end).	2638	each server has a read and write socket end).
…		…
2073	a new one that moves the timeout into the future.	2646	a new one that moves the timeout into the future.
2074		2647
2075	=head3 Results	2648	=head3 Results
2076		2649
2077	name sockets create request	2650	name sockets create request
2078	EV 20000 69.01 11.16	2651	EV 20000 62.66 7.99
2079	Perl 20000 73.32 35.87	2652	Perl 20000 68.32 32.64
2080	IOAsync 20000 157.00 98.14 epoll	2653	IOAsync 20000 174.06 101.15 epoll
2081	IOAsync 20000 159.31 616.06 poll	2654	IOAsync 20000 174.67 610.84 poll
2082	Event 20000 212.62 257.32	2655	Event 20000 202.69 242.91
2083	Glib 20000 651.16 1896.30	2656	Glib 20000 557.01 1689.52
2084	POE 20000 349.67 12317.24 uses POE::Loop::Event	2657	POE 20000 341.54 12086.32 uses POE::Loop::Event
2085		2658
2086	=head3 Discussion	2659	=head3 Discussion
2087		2660
2088	This benchmark I<does> measure scalability and overall performance of the	2661	This benchmark I<does> measure scalability and overall performance of the
2089	particular event loop.	2662	particular event loop.
…		…
2215	As you can see, the AnyEvent + EV combination even beats the	2788	As you can see, the AnyEvent + EV combination even beats the
2216	hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl	2789	hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl
2217	backend easily beats IO::Lambda and POE.	2790	backend easily beats IO::Lambda and POE.
2218		2791
2219	And even the 100% non-blocking version written using the high-level (and	2792	And even the 100% non-blocking version written using the high-level (and
2220	slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda by a	2793	slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda
2221	large margin, even though it does all of DNS, tcp-connect and socket I/O	2794	higher level ("unoptimised") abstractions by a large margin, even though
2222	in a non-blocking way.	2795	it does all of DNS, tcp-connect and socket I/O in a non-blocking way.
2223		2796
2224	The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and	2797	The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and
2225	F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are	2798	F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are
2226	part of the IO::lambda distribution and were used without any changes.	2799	part of the IO::Lambda distribution and were used without any changes.
2227		2800
2228		2801
2229	=head1 SIGNALS	2802	=head1 SIGNALS
2230		2803
2231	AnyEvent currently installs handlers for these signals:	2804	AnyEvent currently installs handlers for these signals:
…		…
2268	unless defined $SIG{PIPE};	2841	unless defined $SIG{PIPE};
2269		2842
2270	=head1 RECOMMENDED/OPTIONAL MODULES	2843	=head1 RECOMMENDED/OPTIONAL MODULES
2271		2844
2272	One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and	2845	One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and
2273	it's built-in modules) are required to use it.	2846	its built-in modules) are required to use it.
2274		2847
2275	That does not mean that AnyEvent won't take advantage of some additional	2848	That does not mean that AnyEvent won't take advantage of some additional
2276	modules if they are installed.	2849	modules if they are installed.
2277		2850
2278	This section epxlains which additional modules will be used, and how they	2851	This section explains which additional modules will be used, and how they
2279	affect AnyEvent's operetion.	2852	affect AnyEvent's operation.
2280		2853
2281	=over 4	2854	=over 4
2282		2855
2283	=item L<Async::Interrupt>	2856	=item L<Async::Interrupt>
2284		2857
…		…
2289	catch the signals) with some delay (default is 10 seconds, look for	2862	catch the signals) with some delay (default is 10 seconds, look for
2290	C<$AnyEvent::MAX_SIGNAL_LATENCY>).	2863	C<$AnyEvent::MAX_SIGNAL_LATENCY>).
2291		2864
2292	If this module is available, then it will be used to implement signal	2865	If this module is available, then it will be used to implement signal
2293	catching, which means that signals will not be delayed, and the event loop	2866	catching, which means that signals will not be delayed, and the event loop
2294	will not be interrupted regularly, which is more efficient (And good for	2867	will not be interrupted regularly, which is more efficient (and good for
2295	battery life on laptops).	2868	battery life on laptops).
2296		2869
2297	This affects not just the pure-perl event loop, but also other event loops	2870	This affects not just the pure-perl event loop, but also other event loops
2298	that have no signal handling on their own (e.g. Glib, Tk, Qt).	2871	that have no signal handling on their own (e.g. Glib, Tk, Qt).
2299		2872
…		…
2311	automatic timer adjustments even when no monotonic clock is available,	2884	automatic timer adjustments even when no monotonic clock is available,
2312	can take avdantage of advanced kernel interfaces such as C<epoll> and	2885	can take avdantage of advanced kernel interfaces such as C<epoll> and
2313	C<kqueue>, and is the fastest backend I<by far>. You can even embed	2886	C<kqueue>, and is the fastest backend I<by far>. You can even embed
2314	L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>).	2887	L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>).
2315		2888
		2889	If you only use backends that rely on another event loop (e.g. C<Tk>),
		2890	then this module will do nothing for you.
		2891
2316	=item L<Guard>	2892	=item L<Guard>
2317		2893
2318	The guard module, when used, will be used to implement	2894	The guard module, when used, will be used to implement
2319	C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a	2895	C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a
2320	lot less memory), but otherwise doesn't affect guard operation much. It is	2896	lot less memory), but otherwise doesn't affect guard operation much. It is
2321	purely used for performance.	2897	purely used for performance.
2322		2898
2323	=item L<JSON> and L<JSON::XS>	2899	=item L<JSON> and L<JSON::XS>
2324		2900
2325	This module is required when you want to read or write JSON data via	2901	One of these modules is required when you want to read or write JSON data
2326	L<AnyEvent::Handle>. It is also written in pure-perl, but can take	2902	via L<AnyEvent::Handle>. L<JSON> is also written in pure-perl, but can take
2327	advantage of the ultra-high-speed L<JSON::XS> module when it is installed.	2903	advantage of the ultra-high-speed L<JSON::XS> module when it is installed.
2328
2329	In fact, L<AnyEvent::Handle> will use L<JSON::XS> by default if it is
2330	installed.
2331		2904
2332	=item L<Net::SSLeay>	2905	=item L<Net::SSLeay>
2333		2906
2334	Implementing TLS/SSL in Perl is certainly interesting, but not very	2907	Implementing TLS/SSL in Perl is certainly interesting, but not very
2335	worthwhile: If this module is installed, then L<AnyEvent::Handle> (with	2908	worthwhile: If this module is installed, then L<AnyEvent::Handle> (with
2336	the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL.	2909	the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL.
2337		2910
2338	=item L<Time::HiRes>	2911	=item L<Time::HiRes>
2339		2912
2340	This module is part of perl since release 5.008. It will be used when the	2913	This module is part of perl since release 5.008. It will be used when the
2341	chosen event library does not come with a timing source on it's own. The	2914	chosen event library does not come with a timing source of its own. The
2342	pure-perl event loop (L<AnyEvent::Impl::Perl>) will additionally use it to	2915	pure-perl event loop (L<AnyEvent::Loop>) will additionally load it to
2343	try to use a monotonic clock for timing stability.	2916	try to use a monotonic clock for timing stability.
2344		2917
2345	=back	2918	=back
2346		2919
2347		2920
2348	=head1 FORK	2921	=head1 FORK
2349		2922
2350	Most event libraries are not fork-safe. The ones who are usually are	2923	Most event libraries are not fork-safe. The ones who are usually are
2351	because they rely on inefficient but fork-safe C<select> or C<poll>	2924	because they rely on inefficient but fork-safe C<select> or C<poll> calls
2352	calls. Only L<EV> is fully fork-aware.	2925	- higher performance APIs such as BSD's kqueue or the dreaded Linux epoll
		2926	are usually badly thought-out hacks that are incompatible with fork in
		2927	one way or another. Only L<EV> is fully fork-aware and ensures that you
		2928	continue event-processing in both parent and child (or both, if you know
		2929	what you are doing).
		2930
		2931	This means that, in general, you cannot fork and do event processing in
		2932	the child if the event library was initialised before the fork (which
		2933	usually happens when the first AnyEvent watcher is created, or the library
		2934	is loaded).
2353		2935
2354	If you have to fork, you must either do so I<before> creating your first	2936	If you have to fork, you must either do so I<before> creating your first
2355	watcher OR you must not use AnyEvent at all in the child OR you must do	2937	watcher OR you must not use AnyEvent at all in the child OR you must do
2356	something completely out of the scope of AnyEvent.	2938	something completely out of the scope of AnyEvent.
		2939
		2940	The problem of doing event processing in the parent I<and> the child
		2941	is much more complicated: even for backends that I<are> fork-aware or
		2942	fork-safe, their behaviour is not usually what you want: fork clones all
		2943	watchers, that means all timers, I/O watchers etc. are active in both
		2944	parent and child, which is almost never what you want. USing C<exec>
		2945	to start worker children from some kind of manage rprocess is usually
		2946	preferred, because it is much easier and cleaner, at the expense of having
		2947	to have another binary.
2357		2948
2358		2949
2359	=head1 SECURITY CONSIDERATIONS	2950	=head1 SECURITY CONSIDERATIONS
2360		2951
2361	AnyEvent can be forced to load any event model via	2952	AnyEvent can be forced to load any event model via
…		…
2391	pronounced).	2982	pronounced).
2392		2983
2393		2984
2394	=head1 SEE ALSO	2985	=head1 SEE ALSO
2395		2986
2396	Utility functions: L<AnyEvent::Util>.	2987	Tutorial/Introduction: L<AnyEvent::Intro>.
2397		2988
2398	Event modules: L<EV>, L<EV::Glib>, L<Glib::EV>, L<Event>, L<Glib::Event>,	2989	FAQ: L<AnyEvent::FAQ>.
2399	L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.	2990
		2991	Utility functions: L<AnyEvent::Util> (misc. grab-bag), L<AnyEvent::Log>
		2992	(simply logging).
		2993
		2994	Development/Debugging: L<AnyEvent::Strict> (stricter checking),
		2995	L<AnyEvent::Debug> (interactive shell, watcher tracing).
		2996
		2997	Supported event modules: L<AnyEvent::Loop>, L<EV>, L<EV::Glib>,
		2998	L<Glib::EV>, L<Event>, L<Glib::Event>, L<Glib>, L<Tk>, L<Event::Lib>,
		2999	L<Qt>, L<POE>, L<FLTK>.
2400		3000
2401	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,	3001	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,
2402	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,	3002	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,
2403	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,	3003	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,
2404	L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>.	3004	L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>, L<Anyevent::Impl::Irssi>,
		3005	L<AnyEvent::Impl::FLTK>.
2405		3006
2406	Non-blocking file handles, sockets, TCP clients and	3007	Non-blocking handles, pipes, stream sockets, TCP clients and
2407	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.	3008	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.
2408		3009
2409	Asynchronous DNS: L<AnyEvent::DNS>.	3010	Asynchronous DNS: L<AnyEvent::DNS>.
2410		3011
2411	Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>,	3012	Thread support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>.
2412	L<Coro::Event>,
2413		3013
2414	Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::XMPP>,	3014	Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::IRC>,
2415	L<AnyEvent::HTTP>.	3015	L<AnyEvent::HTTP>.
2416		3016
2417		3017
2418	=head1 AUTHOR	3018	=head1 AUTHOR
2419		3019

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