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Revision 1.259 by root, Tue Jul 28 02:07:18 2009 UTC vs.
Revision 1.408 by root, Thu Dec 6 12:04:23 2012 UTC

1	=head1 NAME	1	=head1 NAME
2		2
3	AnyEvent - the DBI of event loop programming	3	AnyEvent - the DBI of event loop programming
4		4
5	EV, Event, Glib, Tk, Perl, Event::Lib, Irssi, rxvt-unicode, IO::Async, Qt	5	EV, Event, Glib, Tk, Perl, Event::Lib, Irssi, rxvt-unicode, IO::Async, Qt,
6	and POE are various supported event loops/environments.	6	FLTK and POE are various supported event loops/environments.
7		7
8	=head1 SYNOPSIS	8	=head1 SYNOPSIS
9		9
10	use AnyEvent;	10	use AnyEvent;
11		11
		12	# if you prefer function calls, look at the AE manpage for
		13	# an alternative API.
		14
12	# file descriptor readable	15	# file handle or descriptor readable
13	my $w = AnyEvent->io (fh => $fh, poll => "r", cb => sub { ... });	16	my $w = AnyEvent->io (fh => $fh, poll => "r", cb => sub { ... });
14		17
15	# one-shot or repeating timers	18	# one-shot or repeating timers
16	my $w = AnyEvent->timer (after => $seconds, cb => sub { ... });	19	my $w = AnyEvent->timer (after => $seconds, cb => sub { ... });
17	my $w = AnyEvent->timer (after => $seconds, interval => $seconds, cb => ...	20	my $w = AnyEvent->timer (after => $seconds, interval => $seconds, cb => ...);
18		21
19	print AnyEvent->now; # prints current event loop time	22	print AnyEvent->now; # prints current event loop time
20	print AnyEvent->time; # think Time::HiRes::time or simply CORE::time.	23	print AnyEvent->time; # think Time::HiRes::time or simply CORE::time.
21		24
22	# POSIX signal	25	# POSIX signal
…		…
43	in a tutorial or some gentle introduction, have a look at the	46	in a tutorial or some gentle introduction, have a look at the
44	L<AnyEvent::Intro> manpage.	47	L<AnyEvent::Intro> manpage.
45		48
46	=head1 SUPPORT	49	=head1 SUPPORT
47		50
		51	An FAQ document is available as L<AnyEvent::FAQ>.
		52
48	There is a mailinglist for discussing all things AnyEvent, and an IRC	53	There also is a mailinglist for discussing all things AnyEvent, and an IRC
49	channel, too.	54	channel, too.
50		55
51	See the AnyEvent project page at the B<Schmorpforge Ta-Sa Software	56	See the AnyEvent project page at the B<Schmorpforge Ta-Sa Software
52	Repository>, at L<http://anyevent.schmorp.de>, for more info.	57	Repository>, at L<http://anyevent.schmorp.de>, for more info.
53		58
…		…
73	module users into the same thing by forcing them to use the same event	78	module users into the same thing by forcing them to use the same event
74	model you use.	79	model you use.
75		80
76	For modules like POE or IO::Async (which is a total misnomer as it is	81	For modules like POE or IO::Async (which is a total misnomer as it is
77	actually doing all I/O I<synchronously>...), using them in your module is	82	actually doing all I/O I<synchronously>...), using them in your module is
78	like joining a cult: After you joined, you are dependent on them and you	83	like joining a cult: After you join, you are dependent on them and you
79	cannot use anything else, as they are simply incompatible to everything	84	cannot use anything else, as they are simply incompatible to everything
80	that isn't them. What's worse, all the potential users of your	85	that isn't them. What's worse, all the potential users of your
81	module are I<also> forced to use the same event loop you use.	86	module are I<also> forced to use the same event loop you use.
82		87
83	AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works	88	AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works
84	fine. AnyEvent + Tk works fine etc. etc. but none of these work together	89	fine. AnyEvent + Tk works fine etc. etc. but none of these work together
85	with the rest: POE + IO::Async? No go. Tk + Event? No go. Again: if	90	with the rest: POE + EV? No go. Tk + Event? No go. Again: if your module
86	your module uses one of those, every user of your module has to use it,	91	uses one of those, every user of your module has to use it, too. But if
87	too. But if your module uses AnyEvent, it works transparently with all	92	your module uses AnyEvent, it works transparently with all event models it
88	event models it supports (including stuff like IO::Async, as long as those	93	supports (including stuff like IO::Async, as long as those use one of the
89	use one of the supported event loops. It is trivial to add new event loops	94	supported event loops. It is easy to add new event loops to AnyEvent, too,
90	to AnyEvent, too, so it is future-proof).	95	so it is future-proof).
91		96
92	In addition to being free of having to use I<the one and only true event	97	In addition to being free of having to use I<the one and only true event
93	model>, AnyEvent also is free of bloat and policy: with POE or similar	98	model>, AnyEvent also is free of bloat and policy: with POE or similar
94	modules, you get an enormous amount of code and strict rules you have to	99	modules, you get an enormous amount of code and strict rules you have to
95	follow. AnyEvent, on the other hand, is lean and up to the point, by only	100	follow. AnyEvent, on the other hand, is lean and to the point, by only
96	offering the functionality that is necessary, in as thin as a wrapper as	101	offering the functionality that is necessary, in as thin as a wrapper as
97	technically possible.	102	technically possible.
98		103
99	Of course, AnyEvent comes with a big (and fully optional!) toolbox	104	Of course, AnyEvent comes with a big (and fully optional!) toolbox
100	of useful functionality, such as an asynchronous DNS resolver, 100%	105	of useful functionality, such as an asynchronous DNS resolver, 100%
…		…
106	useful) and you want to force your users to use the one and only event	111	useful) and you want to force your users to use the one and only event
107	model, you should I<not> use this module.	112	model, you should I<not> use this module.
108		113
109	=head1 DESCRIPTION	114	=head1 DESCRIPTION
110		115
111	L<AnyEvent> provides an identical interface to multiple event loops. This	116	L<AnyEvent> provides a uniform interface to various event loops. This
112	allows module authors to utilise an event loop without forcing module	117	allows module authors to use event loop functionality without forcing
113	users to use the same event loop (as only a single event loop can coexist	118	module users to use a specific event loop implementation (since more
114	peacefully at any one time).	119	than one event loop cannot coexist peacefully).
115		120
116	The interface itself is vaguely similar, but not identical to the L<Event>	121	The interface itself is vaguely similar, but not identical to the L<Event>
117	module.	122	module.
118		123
119	During the first call of any watcher-creation method, the module tries	124	During the first call of any watcher-creation method, the module tries
120	to detect the currently loaded event loop by probing whether one of the	125	to detect the currently loaded event loop by probing whether one of the
121	following modules is already loaded: L<EV>,	126	following modules is already loaded: L<EV>, L<AnyEvent::Loop>,
122	L<Event>, L<Glib>, L<AnyEvent::Impl::Perl>, L<Tk>, L<Event::Lib>, L<Qt>,	127	L<Event>, L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>. The first one
123	L<POE>. The first one found is used. If none are found, the module tries	128	found is used. If none are detected, the module tries to load the first
124	to load these modules (excluding Tk, Event::Lib, Qt and POE as the pure perl	129	four modules in the order given; but note that if L<EV> is not
125	adaptor should always succeed) in the order given. The first one that can	130	available, the pure-perl L<AnyEvent::Loop> should always work, so
126	be successfully loaded will be used. If, after this, still none could be	131	the other two are not normally tried.
127	found, AnyEvent will fall back to a pure-perl event loop, which is not
128	very efficient, but should work everywhere.
129		132
130	Because AnyEvent first checks for modules that are already loaded, loading	133	Because AnyEvent first checks for modules that are already loaded, loading
131	an event model explicitly before first using AnyEvent will likely make	134	an event model explicitly before first using AnyEvent will likely make
132	that model the default. For example:	135	that model the default. For example:
133		136
…		…
135	use AnyEvent;	138	use AnyEvent;
136		139
137	# .. AnyEvent will likely default to Tk	140	# .. AnyEvent will likely default to Tk
138		141
139	The I<likely> means that, if any module loads another event model and	142	The I<likely> means that, if any module loads another event model and
140	starts using it, all bets are off. Maybe you should tell their authors to	143	starts using it, all bets are off - this case should be very rare though,
141	use AnyEvent so their modules work together with others seamlessly...	144	as very few modules hardcode event loops without announcing this very
		145	loudly.
142		146
143	The pure-perl implementation of AnyEvent is called	147	The pure-perl implementation of AnyEvent is called C<AnyEvent::Loop>. Like
144	C<AnyEvent::Impl::Perl>. Like other event modules you can load it	148	other event modules you can load it explicitly and enjoy the high
145	explicitly and enjoy the high availability of that event loop :)	149	availability of that event loop :)
146		150
147	=head1 WATCHERS	151	=head1 WATCHERS
148		152
149	AnyEvent has the central concept of a I<watcher>, which is an object that	153	AnyEvent has the central concept of a I<watcher>, which is an object that
150	stores relevant data for each kind of event you are waiting for, such as	154	stores relevant data for each kind of event you are waiting for, such as
…		…
155	callback when the event occurs (of course, only when the event model	159	callback when the event occurs (of course, only when the event model
156	is in control).	160	is in control).
157		161
158	Note that B<callbacks must not permanently change global variables>	162	Note that B<callbacks must not permanently change global variables>
159	potentially in use by the event loop (such as C<$_> or C<$[>) and that B<<	163	potentially in use by the event loop (such as C<$_> or C<$[>) and that B<<
160	callbacks must not C<die> >>. The former is good programming practise in	164	callbacks must not C<die> >>. The former is good programming practice in
161	Perl and the latter stems from the fact that exception handling differs	165	Perl and the latter stems from the fact that exception handling differs
162	widely between event loops.	166	widely between event loops.
163		167
164	To disable the watcher you have to destroy it (e.g. by setting the	168	To disable a watcher you have to destroy it (e.g. by setting the
165	variable you store it in to C<undef> or otherwise deleting all references	169	variable you store it in to C<undef> or otherwise deleting all references
166	to it).	170	to it).
167		171
168	All watchers are created by calling a method on the C<AnyEvent> class.	172	All watchers are created by calling a method on the C<AnyEvent> class.
169		173
170	Many watchers either are used with "recursion" (repeating timers for	174	Many watchers either are used with "recursion" (repeating timers for
171	example), or need to refer to their watcher object in other ways.	175	example), or need to refer to their watcher object in other ways.
172		176
173	An any way to achieve that is this pattern:	177	One way to achieve that is this pattern:
174		178
175	my $w; $w = AnyEvent->type (arg => value ..., cb => sub {	179	my $w; $w = AnyEvent->type (arg => value ..., cb => sub {
176	# you can use $w here, for example to undef it	180	# you can use $w here, for example to undef it
177	undef $w;	181	undef $w;
178	});	182	});
…		…
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 (one some backends,	453	The child process is specified by the C<pid> argument (on some backends,
406	using C<0> watches for any child process exit, on others this will	454	using C<0> watches for any child process exit, on others this will
407	croak). The watcher will be triggered only when the child process has	455	croak). The watcher will be triggered only when the child process has
408	finished and an exit status is available, not on any trace events	456	finished and an exit status is available, not on any trace events
409	(stopped/continued).	457	(stopped/continued).
410		458
…		…
432	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
433	watcher before you C<fork> the child (alternatively, you can call	481	watcher before you C<fork> the child (alternatively, you can call
434	C<AnyEvent::detect>).	482	C<AnyEvent::detect>).
435		483
436	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
437	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
438	mentioned in the description of signal watchers apply.	486	problems mentioned in the description of signal watchers apply.
439		487
440	Example: fork a process and wait for it	488	Example: fork a process and wait for it
441		489
442	my $done = AnyEvent->condvar;	490	my $done = AnyEvent->condvar;
443		491
…		…
455	# do something else, then wait for process exit	503	# do something else, then wait for process exit
456	$done->recv;	504	$done->recv;
457		505
458	=head2 IDLE WATCHERS	506	=head2 IDLE WATCHERS
459		507
460	Sometimes there is a need to do something, but it is not so important	508	$w = AnyEvent->idle (cb => <callback>);
461	to do it instantly, but only when there is nothing better to do. This
462	"nothing better to do" is usually defined to be "no other events need
463	attention by the event loop".
464		509
465	Idle watchers ideally get invoked when the event loop has nothing	510	This will repeatedly invoke the callback after the process becomes idle,
466	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.
467	events. Instead of blocking, the idle watcher is invoked.
468		512
469	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
470	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
471	will simply call the callback "from time to time".	524	will simply call the callback "from time to time".
472		525
473	Example: read lines from STDIN, but only process them when the	526	Example: read lines from STDIN, but only process them when the
474	program is otherwise idle:	527	program is otherwise idle:
…		…
490	});	543	});
491	});	544	});
492		545
493	=head2 CONDITION VARIABLES	546	=head2 CONDITION VARIABLES
494		547
		548	$cv = AnyEvent->condvar;
		549
		550	$cv->send (<list>);
		551	my @res = $cv->recv;
		552
495	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
496	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
497	will actively watch for new events and call your callbacks.	555	will actively watch for new events and call your callbacks.
498		556
499	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
500	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).
501		559
502	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
503	because they represent a condition that must become true.	561	they represent a condition that must become true.
504		562
505	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.
506		564
507	Condition variables can be created by calling the C<< AnyEvent->condvar	565	Condition variables can be created by calling the C<< AnyEvent->condvar
508	>> method, usually without arguments. The only argument pair allowed is	566	>> method, usually without arguments. The only argument pair allowed is
…		…
513	After creation, the condition variable is "false" until it becomes "true"	571	After creation, the condition variable is "false" until it becomes "true"
514	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
515	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<<
516	->send >> method).	574	->send >> method).
517		575
518	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
519	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:
520	in time where multiple outstanding events have been processed. And yet	578
521	another way to call them is transactions - each condition variable can be	579	=over 4
522	used to represent a transaction, which finishes at some point and delivers	580
523	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
524	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
525		599
526	Condition variables are very useful to signal that something has finished,	600	Condition variables are very useful to signal that something has finished,
527	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,
528	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
529	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
…		…
542		616
543	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
544	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
545	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
546	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
547	it's C<new> method in your own C<new> method.	621	its C<new> method in your own C<new> method.
548		622
549	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
550	eventually calls C<< -> send >>, and the "consumer side", which waits	624	eventually calls C<< -> send >>, and the "consumer side", which waits
551	for the send to occur.	625	for the send to occur.
552		626
553	Example: wait for a timer.	627	Example: wait for a timer.
554		628
555	# wait till the result is ready	629	# condition: "wait till the timer is fired"
556	my $result_ready = AnyEvent->condvar;	630	my $timer_fired = AnyEvent->condvar;
557		631
558	# do something such as adding a timer	632	# create the timer - we could wait for, say
559	# or socket watcher the calls $result_ready->send	633	# a handle becomign ready, or even an
560	# when the "result" is ready.	634	# AnyEvent::HTTP request to finish, but
561	# in this case, we simply use a timer:	635	# in this case, we simply use a timer:
562	my $w = AnyEvent->timer (	636	my $w = AnyEvent->timer (
563	after => 1,	637	after => 1,
564	cb => sub { $result_ready->send },	638	cb => sub { $timer_fired->send },
565	);	639	);
566		640
567	# this "blocks" (while handling events) till the callback	641	# this "blocks" (while handling events) till the callback
568	# calls -<send	642	# calls ->send
569	$result_ready->recv;	643	$timer_fired->recv;
570		644
571	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
572	variables are also callable directly.	646	variables are also callable directly.
573		647
574	my $done = AnyEvent->condvar;	648	my $done = AnyEvent->condvar;
…		…
617	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
618	C<send>.	692	C<send>.
619		693
620	=item $cv->croak ($error)	694	=item $cv->croak ($error)
621		695
622	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
623	C<Carp::croak> with the given error message/object/scalar.	697	C<Carp::croak> with the given error message/object/scalar.
624		698
625	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
626	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
627	delays the error detetcion, but has the overwhelmign advantage that it	701	delays the error detection, but has the overwhelming advantage that it
628	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
629	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
630	the problem.	704	the problem.
631		705
632	=item $cv->begin ([group callback])	706	=item $cv->begin ([group callback])
633		707
634	=item $cv->end	708	=item $cv->end
…		…
637	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
638	to use a condition variable for the whole process.	712	to use a condition variable for the whole process.
639		713
640	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
641	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
642	>>, 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
643	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
644	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.
645		720
646	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
647	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
648	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).
649		724
…		…
671	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
672	sending.	747	sending.
673		748
674	The ping example mentioned above is slightly more complicated, as the	749	The ping example mentioned above is slightly more complicated, as the
675	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
676	begung can potentially be zero:	751	begun can potentially be zero:
677		752
678	my $cv = AnyEvent->condvar;	753	my $cv = AnyEvent->condvar;
679		754
680	my %result;	755	my %result;
681	$cv->begin (sub { $cv->send (\%result) });	756	$cv->begin (sub { shift->send (\%result) });
682		757
683	for my $host (@list_of_hosts) {	758	for my $host (@list_of_hosts) {
684	$cv->begin;	759	$cv->begin;
685	ping_host_then_call_callback $host, sub {	760	ping_host_then_call_callback $host, sub {
686	$result{$host} = ...;	761	$result{$host} = ...;
…		…
688	};	763	};
689	}	764	}
690		765
691	$cv->end;	766	$cv->end;
692		767
		768	...
		769
		770	my $results = $cv->recv;
		771
693	This code fragment supposedly pings a number of hosts and calls	772	This code fragment supposedly pings a number of hosts and calls
694	C<send> after results for all then have have been gathered - in any	773	C<send> after results for all then have have been gathered - in any
695	order. To achieve this, the code issues a call to C<begin> when it starts	774	order. To achieve this, the code issues a call to C<begin> when it starts
696	each ping request and calls C<end> when it has received some result for	775	each ping request and calls C<end> when it has received some result for
697	it. Since C<begin> and C<end> only maintain a counter, the order in which	776	it. Since C<begin> and C<end> only maintain a counter, the order in which
…		…
702	to be called once the counter reaches C<0>, and second, it ensures that	781	to be called once the counter reaches C<0>, and second, it ensures that
703	C<send> is called even when C<no> hosts are being pinged (the loop	782	C<send> is called even when C<no> hosts are being pinged (the loop
704	doesn't execute once).	783	doesn't execute once).
705		784
706	This is the general pattern when you "fan out" into multiple (but	785	This is the general pattern when you "fan out" into multiple (but
707	potentially none) subrequests: use an outer C<begin>/C<end> pair to set	786	potentially zero) subrequests: use an outer C<begin>/C<end> pair to set
708	the callback and ensure C<end> is called at least once, and then, for each	787	the callback and ensure C<end> is called at least once, and then, for each
709	subrequest you start, call C<begin> and for each subrequest you finish,	788	subrequest you start, call C<begin> and for each subrequest you finish,
710	call C<end>.	789	call C<end>.
711		790
712	=back	791	=back
…		…
719	=over 4	798	=over 4
720		799
721	=item $cv->recv	800	=item $cv->recv
722		801
723	Wait (blocking if necessary) until the C<< ->send >> or C<< ->croak	802	Wait (blocking if necessary) until the C<< ->send >> or C<< ->croak
724	>> methods have been called on c<$cv>, while servicing other watchers	803	>> methods have been called on C<$cv>, while servicing other watchers
725	normally.	804	normally.
726		805
727	You can only wait once on a condition - additional calls are valid but	806	You can only wait once on a condition - additional calls are valid but
728	will return immediately.	807	will return immediately.
729		808
…		…
746	caller decide whether the call will block or not (for example, by coupling	825	caller decide whether the call will block or not (for example, by coupling
747	condition variables with some kind of request results and supporting	826	condition variables with some kind of request results and supporting
748	callbacks so the caller knows that getting the result will not block,	827	callbacks so the caller knows that getting the result will not block,
749	while still supporting blocking waits if the caller so desires).	828	while still supporting blocking waits if the caller so desires).
750		829
751	You can ensure that C<< -recv >> never blocks by setting a callback and	830	You can ensure that C<< ->recv >> never blocks by setting a callback and
752	only calling C<< ->recv >> from within that callback (or at a later	831	only calling C<< ->recv >> from within that callback (or at a later
753	time). This will work even when the event loop does not support blocking	832	time). This will work even when the event loop does not support blocking
754	waits otherwise.	833	waits otherwise.
755		834
756	=item $bool = $cv->ready	835	=item $bool = $cv->ready
…		…
762		841
763	This is a mutator function that returns the callback set and optionally	842	This is a mutator function that returns the callback set and optionally
764	replaces it before doing so.	843	replaces it before doing so.
765		844
766	The callback will be called when the condition becomes "true", i.e. when	845	The callback will be called when the condition becomes "true", i.e. when
767	C<send> or C<croak> are called, with the only argument being the condition	846	C<send> or C<croak> are called, with the only argument being the
768	variable itself. Calling C<recv> inside the callback or at any later time	847	condition variable itself. If the condition is already true, the
769	is guaranteed not to block.	848	callback is called immediately when it is set. Calling C<recv> inside
		849	the callback or at any later time is guaranteed not to block.
770		850
771	=back	851	=back
772		852
773	=head1 SUPPORTED EVENT LOOPS/BACKENDS	853	=head1 SUPPORTED EVENT LOOPS/BACKENDS
774		854
…		…
777	=over 4	857	=over 4
778		858
779	=item Backends that are autoprobed when no other event loop can be found.	859	=item Backends that are autoprobed when no other event loop can be found.
780		860
781	EV is the preferred backend when no other event loop seems to be in	861	EV is the preferred backend when no other event loop seems to be in
782	use. If EV is not installed, then AnyEvent will try Event, and, failing	862	use. If EV is not installed, then AnyEvent will fall back to its own
783	that, will fall back to its own pure-perl implementation, which is	863	pure-perl implementation, which is available everywhere as it comes with
784	available everywhere as it comes with AnyEvent itself.	864	AnyEvent itself.
785		865
786	AnyEvent::Impl::EV based on EV (interface to libev, best choice).	866	AnyEvent::Impl::EV based on EV (interface to libev, best choice).
787	AnyEvent::Impl::Event based on Event, very stable, few glitches.
788	AnyEvent::Impl::Perl pure-perl implementation, fast and portable.	867	AnyEvent::Impl::Perl pure-perl AnyEvent::Loop, fast and portable.
789		868
790	=item Backends that are transparently being picked up when they are used.	869	=item Backends that are transparently being picked up when they are used.
791		870
792	These will be used when they are currently loaded when the first watcher	871	These will be used if they are already loaded when the first watcher
793	is created, in which case it is assumed that the application is using	872	is created, in which case it is assumed that the application is using
794	them. This means that AnyEvent will automatically pick the right backend	873	them. This means that AnyEvent will automatically pick the right backend
795	when the main program loads an event module before anything starts to	874	when the main program loads an event module before anything starts to
796	create watchers. Nothing special needs to be done by the main program.	875	create watchers. Nothing special needs to be done by the main program.
797		876
		877	AnyEvent::Impl::Event based on Event, very stable, few glitches.
798	AnyEvent::Impl::Glib based on Glib, slow but very stable.	878	AnyEvent::Impl::Glib based on Glib, slow but very stable.
799	AnyEvent::Impl::Tk based on Tk, very broken.	879	AnyEvent::Impl::Tk based on Tk, very broken.
800	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.	880	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
801	AnyEvent::Impl::POE based on POE, very slow, some limitations.	881	AnyEvent::Impl::POE based on POE, very slow, some limitations.
802	AnyEvent::Impl::Irssi used when running within irssi.	882	AnyEvent::Impl::Irssi used when running within irssi.
		883	AnyEvent::Impl::IOAsync based on IO::Async.
		884	AnyEvent::Impl::Cocoa based on Cocoa::EventLoop.
		885	AnyEvent::Impl::FLTK based on FLTK (fltk 2 binding).
803		886
804	=item Backends with special needs.	887	=item Backends with special needs.
805		888
806	Qt requires the Qt::Application to be instantiated first, but will	889	Qt requires the Qt::Application to be instantiated first, but will
807	otherwise be picked up automatically. As long as the main program	890	otherwise be picked up automatically. As long as the main program
808	instantiates the application before any AnyEvent watchers are created,	891	instantiates the application before any AnyEvent watchers are created,
809	everything should just work.	892	everything should just work.
810		893
811	AnyEvent::Impl::Qt based on Qt.	894	AnyEvent::Impl::Qt based on Qt.
812		895
813	Support for IO::Async can only be partial, as it is too broken and
814	architecturally limited to even support the AnyEvent API. It also
815	is the only event loop that needs the loop to be set explicitly, so
816	it can only be used by a main program knowing about AnyEvent. See
817	L<AnyEvent::Impl::Async> for the gory details.
818
819	AnyEvent::Impl::IOAsync based on IO::Async, cannot be autoprobed.
820
821	=item Event loops that are indirectly supported via other backends.	896	=item Event loops that are indirectly supported via other backends.
822		897
823	Some event loops can be supported via other modules:	898	Some event loops can be supported via other modules:
824		899
825	There is no direct support for WxWidgets (L<Wx>) or L<Prima>.	900	There is no direct support for WxWidgets (L<Wx>) or L<Prima>.
…		…
850	Contains C<undef> until the first watcher is being created, before the	925	Contains C<undef> until the first watcher is being created, before the
851	backend has been autodetected.	926	backend has been autodetected.
852		927
853	Afterwards it contains the event model that is being used, which is the	928	Afterwards it contains the event model that is being used, which is the
854	name of the Perl class implementing the model. This class is usually one	929	name of the Perl class implementing the model. This class is usually one
855	of the C<AnyEvent::Impl:xxx> modules, but can be any other class in the	930	of the C<AnyEvent::Impl::xxx> modules, but can be any other class in the
856	case AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode> it	931	case AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode> it
857	will be C<urxvt::anyevent>).	932	will be C<urxvt::anyevent>).
858		933
859	=item AnyEvent::detect	934	=item AnyEvent::detect
860		935
861	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model	936	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model
862	if necessary. You should only call this function right before you would	937	if necessary. You should only call this function right before you would
863	have created an AnyEvent watcher anyway, that is, as late as possible at	938	have created an AnyEvent watcher anyway, that is, as late as possible at
864	runtime, and not e.g. while initialising of your module.	939	runtime, and not e.g. during initialisation of your module.
		940
		941	The effect of calling this function is as if a watcher had been created
		942	(specifically, actions that happen "when the first watcher is created"
		943	happen when calling detetc as well).
865		944
866	If you need to do some initialisation before AnyEvent watchers are	945	If you need to do some initialisation before AnyEvent watchers are
867	created, use C<post_detect>.	946	created, use C<post_detect>.
868		947
869	=item $guard = AnyEvent::post_detect { BLOCK }	948	=item $guard = AnyEvent::post_detect { BLOCK }
870		949
871	Arranges for the code block to be executed as soon as the event model is	950	Arranges for the code block to be executed as soon as the event model is
872	autodetected (or immediately if this has already happened).	951	autodetected (or immediately if that has already happened).
873		952
874	The block will be executed I<after> the actual backend has been detected	953	The block will be executed I<after> the actual backend has been detected
875	(C<$AnyEvent::MODEL> is set), but I<before> any watchers have been	954	(C<$AnyEvent::MODEL> is set), but I<before> any watchers have been
876	created, so it is possible to e.g. patch C<@AnyEvent::ISA> or do	955	created, so it is possible to e.g. patch C<@AnyEvent::ISA> or do
877	other initialisations - see the sources of L<AnyEvent::Strict> or	956	other initialisations - see the sources of L<AnyEvent::Strict> or
…		…
886	that automatically removes the callback again when it is destroyed (or	965	that automatically removes the callback again when it is destroyed (or
887	C<undef> when the hook was immediately executed). See L<AnyEvent::AIO> for	966	C<undef> when the hook was immediately executed). See L<AnyEvent::AIO> for
888	a case where this is useful.	967	a case where this is useful.
889		968
890	Example: Create a watcher for the IO::AIO module and store it in	969	Example: Create a watcher for the IO::AIO module and store it in
891	C<$WATCHER>. Only do so after the event loop is initialised, though.	970	C<$WATCHER>, but do so only do so after the event loop is initialised.
892		971
893	our WATCHER;	972	our WATCHER;
894		973
895	my $guard = AnyEvent::post_detect {	974	my $guard = AnyEvent::post_detect {
896	$WATCHER = AnyEvent->io (fh => IO::AIO::poll_fileno, poll => 'r', cb => \&IO::AIO::poll_cb);	975	$WATCHER = AnyEvent->io (fh => IO::AIO::poll_fileno, poll => 'r', cb => \&IO::AIO::poll_cb);
…		…
904	$WATCHER ||= $guard;	983	$WATCHER ||= $guard;
905		984
906	=item @AnyEvent::post_detect	985	=item @AnyEvent::post_detect
907		986
908	If there are any code references in this array (you can C<push> to it	987	If there are any code references in this array (you can C<push> to it
909	before or after loading AnyEvent), then they will called directly after	988	before or after loading AnyEvent), then they will be called directly
910	the event loop has been chosen.	989	after the event loop has been chosen.
911		990
912	You should check C<$AnyEvent::MODEL> before adding to this array, though:	991	You should check C<$AnyEvent::MODEL> before adding to this array, though:
913	if it is defined then the event loop has already been detected, and the	992	if it is defined then the event loop has already been detected, and the
914	array will be ignored.	993	array will be ignored.
915		994
916	Best use C<AnyEvent::post_detect { BLOCK }> when your application allows	995	Best use C<AnyEvent::post_detect { BLOCK }> when your application allows
917	it,as it takes care of these details.	996	it, as it takes care of these details.
918		997
919	This variable is mainly useful for modules that can do something useful	998	This variable is mainly useful for modules that can do something useful
920	when AnyEvent is used and thus want to know when it is initialised, but do	999	when AnyEvent is used and thus want to know when it is initialised, but do
921	not need to even load it by default. This array provides the means to hook	1000	not need to even load it by default. This array provides the means to hook
922	into AnyEvent passively, without loading it.	1001	into AnyEvent passively, without loading it.
923		1002
		1003	Example: To load Coro::AnyEvent whenever Coro and AnyEvent are used
		1004	together, you could put this into Coro (this is the actual code used by
		1005	Coro to accomplish this):
		1006
		1007	if (defined $AnyEvent::MODEL) {
		1008	# AnyEvent already initialised, so load Coro::AnyEvent
		1009	require Coro::AnyEvent;
		1010	} else {
		1011	# AnyEvent not yet initialised, so make sure to load Coro::AnyEvent
		1012	# as soon as it is
		1013	push @AnyEvent::post_detect, sub { require Coro::AnyEvent };
		1014	}
		1015
		1016	=item AnyEvent::postpone { BLOCK }
		1017
		1018	Arranges for the block to be executed as soon as possible, but not before
		1019	the call itself returns. In practise, the block will be executed just
		1020	before the event loop polls for new events, or shortly afterwards.
		1021
		1022	This function never returns anything (to make the C<return postpone { ...
		1023	}> idiom more useful.
		1024
		1025	To understand the usefulness of this function, consider a function that
		1026	asynchronously does something for you and returns some transaction
		1027	object or guard to let you cancel the operation. For example,
		1028	C<AnyEvent::Socket::tcp_connect>:
		1029
		1030	# start a conenction attempt unless one is active
		1031	$self->{connect_guard} ||= AnyEvent::Socket::tcp_connect "www.example.net", 80, sub {
		1032	delete $self->{connect_guard};
		1033	...
		1034	};
		1035
		1036	Imagine that this function could instantly call the callback, for
		1037	example, because it detects an obvious error such as a negative port
		1038	number. Invoking the callback before the function returns causes problems
		1039	however: the callback will be called and will try to delete the guard
		1040	object. But since the function hasn't returned yet, there is nothing to
		1041	delete. When the function eventually returns it will assign the guard
		1042	object to C<< $self->{connect_guard} >>, where it will likely never be
		1043	deleted, so the program thinks it is still trying to connect.
		1044
		1045	This is where C<AnyEvent::postpone> should be used. Instead of calling the
		1046	callback directly on error:
		1047
		1048	$cb->(undef), return # signal error to callback, BAD!
		1049	if $some_error_condition;
		1050
		1051	It should use C<postpone>:
		1052
		1053	AnyEvent::postpone { $cb->(undef) }, return # signal error to callback, later
		1054	if $some_error_condition;
		1055
		1056	=item AnyEvent::log $level, $msg[, @args]
		1057
		1058	Log the given C<$msg> at the given C<$level>.
		1059
		1060	If L<AnyEvent::Log> is not loaded then this function makes a simple test
		1061	to see whether the message will be logged. If the test succeeds it will
		1062	load AnyEvent::Log and call C<AnyEvent::Log::log> - consequently, look at
		1063	the L<AnyEvent::Log> documentation for details.
		1064
		1065	If the test fails it will simply return. Right now this happens when a
		1066	numerical loglevel is used and it is larger than the level specified via
		1067	C<$ENV{PERL_ANYEVENT_VERBOSE}>.
		1068
		1069	If you want to sprinkle loads of logging calls around your code, consider
		1070	creating a logger callback with the C<AnyEvent::Log::logger> function,
		1071	which can reduce typing, codesize and can reduce the logging overhead
		1072	enourmously.
		1073
924	=back	1074	=back
925		1075
926	=head1 WHAT TO DO IN A MODULE	1076	=head1 WHAT TO DO IN A MODULE
927		1077
928	As a module author, you should C<use AnyEvent> and call AnyEvent methods	1078	As a module author, you should C<use AnyEvent> and call AnyEvent methods
…		…
938	because it will stall the whole program, and the whole point of using	1088	because it will stall the whole program, and the whole point of using
939	events is to stay interactive.	1089	events is to stay interactive.
940		1090
941	It is fine, however, to call C<< ->recv >> when the user of your module	1091	It is fine, however, to call C<< ->recv >> when the user of your module
942	requests it (i.e. if you create a http request object ad have a method	1092	requests it (i.e. if you create a http request object ad have a method
943	called C<results> that returns the results, it should call C<< ->recv >>	1093	called C<results> that returns the results, it may call C<< ->recv >>
944	freely, as the user of your module knows what she is doing. always).	1094	freely, as the user of your module knows what she is doing. Always).
945		1095
946	=head1 WHAT TO DO IN THE MAIN PROGRAM	1096	=head1 WHAT TO DO IN THE MAIN PROGRAM
947		1097
948	There will always be a single main program - the only place that should	1098	There will always be a single main program - the only place that should
949	dictate which event model to use.	1099	dictate which event model to use.
950		1100
951	If it doesn't care, it can just "use AnyEvent" and use it itself, or not	1101	If the program is not event-based, it need not do anything special, even
952	do anything special (it does not need to be event-based) and let AnyEvent	1102	when it depends on a module that uses an AnyEvent. If the program itself
953	decide which implementation to chose if some module relies on it.	1103	uses AnyEvent, but does not care which event loop is used, all it needs
		1104	to do is C<use AnyEvent>. In either case, AnyEvent will choose the best
		1105	available loop implementation.
954		1106
955	If the main program relies on a specific event model - for example, in	1107	If the main program relies on a specific event model - for example, in
956	Gtk2 programs you have to rely on the Glib module - you should load the	1108	Gtk2 programs you have to rely on the Glib module - you should load the
957	event module before loading AnyEvent or any module that uses it: generally	1109	event module before loading AnyEvent or any module that uses it: generally
958	speaking, you should load it as early as possible. The reason is that	1110	speaking, you should load it as early as possible. The reason is that
959	modules might create watchers when they are loaded, and AnyEvent will	1111	modules might create watchers when they are loaded, and AnyEvent will
960	decide on the event model to use as soon as it creates watchers, and it	1112	decide on the event model to use as soon as it creates watchers, and it
961	might chose the wrong one unless you load the correct one yourself.	1113	might choose the wrong one unless you load the correct one yourself.
962		1114
963	You can chose to use a pure-perl implementation by loading the	1115	You can chose to use a pure-perl implementation by loading the
964	C<AnyEvent::Impl::Perl> module, which gives you similar behaviour	1116	C<AnyEvent::Loop> module, which gives you similar behaviour
965	everywhere, but letting AnyEvent chose the model is generally better.	1117	everywhere, but letting AnyEvent chose the model is generally better.
966		1118
967	=head2 MAINLOOP EMULATION	1119	=head2 MAINLOOP EMULATION
968		1120
969	Sometimes (often for short test scripts, or even standalone programs who	1121	Sometimes (often for short test scripts, or even standalone programs who
…		…
982		1134
983		1135
984	=head1 OTHER MODULES	1136	=head1 OTHER MODULES
985		1137
986	The following is a non-exhaustive list of additional modules that use	1138	The following is a non-exhaustive list of additional modules that use
987	AnyEvent as a client and can therefore be mixed easily with other AnyEvent	1139	AnyEvent as a client and can therefore be mixed easily with other
988	modules and other event loops in the same program. Some of the modules	1140	AnyEvent modules and other event loops in the same program. Some of the
989	come with AnyEvent, most are available via CPAN.	1141	modules come as part of AnyEvent, the others are available via CPAN (see
		1142	L<http://search.cpan.org/search?m=module&q=anyevent%3A%3A*> for
		1143	a longer non-exhaustive list), and the list is heavily biased towards
		1144	modules of the AnyEvent author himself :)
990		1145
991	=over 4	1146	=over 4
992		1147
993	=item L<AnyEvent::Util>	1148	=item L<AnyEvent::Util>
994		1149
995	Contains various utility functions that replace often-used but blocking	1150	Contains various utility functions that replace often-used blocking
996	functions such as C<inet_aton> by event-/callback-based versions.	1151	functions such as C<inet_aton> with event/callback-based versions.
997		1152
998	=item L<AnyEvent::Socket>	1153	=item L<AnyEvent::Socket>
999		1154
1000	Provides various utility functions for (internet protocol) sockets,	1155	Provides various utility functions for (internet protocol) sockets,
1001	addresses and name resolution. Also functions to create non-blocking tcp	1156	addresses and name resolution. Also functions to create non-blocking tcp
…		…
1003		1158
1004	=item L<AnyEvent::Handle>	1159	=item L<AnyEvent::Handle>
1005		1160
1006	Provide read and write buffers, manages watchers for reads and writes,	1161	Provide read and write buffers, manages watchers for reads and writes,
1007	supports raw and formatted I/O, I/O queued and fully transparent and	1162	supports raw and formatted I/O, I/O queued and fully transparent and
1008	non-blocking SSL/TLS (via L<AnyEvent::TLS>.	1163	non-blocking SSL/TLS (via L<AnyEvent::TLS>).
1009		1164
1010	=item L<AnyEvent::DNS>	1165	=item L<AnyEvent::DNS>
1011		1166
1012	Provides rich asynchronous DNS resolver capabilities.	1167	Provides rich asynchronous DNS resolver capabilities.
1013		1168
		1169	=item L<AnyEvent::HTTP>, L<AnyEvent::IRC>, L<AnyEvent::XMPP>, L<AnyEvent::GPSD>, L<AnyEvent::IGS>, L<AnyEvent::FCP>
		1170
		1171	Implement event-based interfaces to the protocols of the same name (for
		1172	the curious, IGS is the International Go Server and FCP is the Freenet
		1173	Client Protocol).
		1174
1014	=item L<AnyEvent::HTTP>	1175	=item L<AnyEvent::AIO>
1015		1176
1016	A simple-to-use HTTP library that is capable of making a lot of concurrent	1177	Truly asynchronous (as opposed to non-blocking) I/O, should be in the
1017	HTTP requests.	1178	toolbox of every event programmer. AnyEvent::AIO transparently fuses
		1179	L<IO::AIO> and AnyEvent together, giving AnyEvent access to event-based
		1180	file I/O, and much more.
		1181
		1182	=item L<AnyEvent::Filesys::Notify>
		1183
		1184	AnyEvent is good for non-blocking stuff, but it can't detect file or
		1185	path changes (e.g. "watch this directory for new files", "watch this
		1186	file for changes"). The L<AnyEvent::Filesys::Notify> module promises to
		1187	do just that in a portbale fashion, supporting inotify on GNU/Linux and
		1188	some weird, without doubt broken, stuff on OS X to monitor files. It can
		1189	fall back to blocking scans at regular intervals transparently on other
		1190	platforms, so it's about as portable as it gets.
		1191
		1192	(I haven't used it myself, but I haven't heard anybody complaining about
		1193	it yet).
		1194
		1195	=item L<AnyEvent::DBI>
		1196
		1197	Executes L<DBI> requests asynchronously in a proxy process for you,
		1198	notifying you in an event-based way when the operation is finished.
1018		1199
1019	=item L<AnyEvent::HTTPD>	1200	=item L<AnyEvent::HTTPD>
1020		1201
1021	Provides a simple web application server framework.	1202	A simple embedded webserver.
1022		1203
1023	=item L<AnyEvent::FastPing>	1204	=item L<AnyEvent::FastPing>
1024		1205
1025	The fastest ping in the west.	1206	The fastest ping in the west.
1026		1207
1027	=item L<AnyEvent::DBI>
1028
1029	Executes L<DBI> requests asynchronously in a proxy process.
1030
1031	=item L<AnyEvent::AIO>
1032
1033	Truly asynchronous I/O, should be in the toolbox of every event
1034	programmer. AnyEvent::AIO transparently fuses L<IO::AIO> and AnyEvent
1035	together.
1036
1037	=item L<AnyEvent::BDB>
1038
1039	Truly asynchronous Berkeley DB access. AnyEvent::BDB transparently fuses
1040	L<BDB> and AnyEvent together.
1041
1042	=item L<AnyEvent::GPSD>
1043
1044	A non-blocking interface to gpsd, a daemon delivering GPS information.
1045
1046	=item L<AnyEvent::IRC>
1047
1048	AnyEvent based IRC client module family (replacing the older Net::IRC3).
1049
1050	=item L<AnyEvent::XMPP>
1051
1052	AnyEvent based XMPP (Jabber protocol) module family (replacing the older
1053	Net::XMPP2>.
1054
1055	=item L<AnyEvent::IGS>
1056
1057	A non-blocking interface to the Internet Go Server protocol (used by
1058	L<App::IGS>).
1059
1060	=item L<Net::FCP>
1061
1062	AnyEvent-based implementation of the Freenet Client Protocol, birthplace
1063	of AnyEvent.
1064
1065	=item L<Event::ExecFlow>
1066
1067	High level API for event-based execution flow control.
1068
1069	=item L<Coro>	1208	=item L<Coro>
1070		1209
1071	Has special support for AnyEvent via L<Coro::AnyEvent>.	1210	Has special support for AnyEvent via L<Coro::AnyEvent>, which allows you
		1211	to simply invert the flow control - don't call us, we will call you:
		1212
		1213	async {
		1214	Coro::AnyEvent::sleep 5; # creates a 5s timer and waits for it
		1215	print "5 seconds later!\n";
		1216
		1217	Coro::AnyEvent::readable *STDIN; # uses an I/O watcher
		1218	my $line = <STDIN>; # works for ttys
		1219
		1220	AnyEvent::HTTP::http_get "url", Coro::rouse_cb;
		1221	my ($body, $hdr) = Coro::rouse_wait;
		1222	};
1072		1223
1073	=back	1224	=back
1074		1225
1075	=cut	1226	=cut
1076		1227
1077	package AnyEvent;	1228	package AnyEvent;
1078		1229
1079	# basically a tuned-down version of common::sense	1230	# basically a tuned-down version of common::sense
1080	sub common_sense {	1231	sub common_sense {
1081	# no warnings	1232	# from common:.sense 3.5
1082	${^WARNING_BITS} ^= ${^WARNING_BITS};	1233	local $^W;
1083	# use strict vars subs	1234	${^WARNING_BITS} ^= ${^WARNING_BITS} ^ "\x3c\x3f\x33\x00\x0f\xf0\x0f\xc0\xf0\xfc\x33\x00";
		1235	# use strict vars subs - NO UTF-8, as Util.pm doesn't like this atm. (uts46data.pl)
1084	$^H |= 0x00000600;	1236	$^H |= 0x00000600;
1085	}	1237	}
1086		1238
1087	BEGIN { AnyEvent::common_sense }	1239	BEGIN { AnyEvent::common_sense }
1088		1240
1089	use Carp ();	1241	use Carp ();
1090		1242
1091	our $VERSION = 4.88;	1243	our $VERSION = '7.04';
1092	our $MODEL;	1244	our $MODEL;
1093
1094	our $AUTOLOAD;
1095	our @ISA;	1245	our @ISA;
1096
1097	our @REGISTRY;	1246	our @REGISTRY;
1098
1099	our $WIN32;
1100
1101	our $VERBOSE;	1247	our $VERBOSE;
		1248	our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred
		1249	our $MAX_SIGNAL_LATENCY = $ENV{PERL_ANYEVENT_MAX_SIGNAL_LATENCY} || 10; # executes after the BEGIN block below (tainting!)
1102		1250
1103	BEGIN {	1251	BEGIN {
1104	eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }";	1252	require "AnyEvent/constants.pl";
		1253
1105	eval "sub TAINT(){ " . (${^TAINT}*1) . " }";	1254	eval "sub TAINT (){" . (${^TAINT}*1) . "}";
1106		1255
1107	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}	1256	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}
1108	if ${^TAINT};	1257	if ${^TAINT};
1109		1258
1110	$VERBOSE = $ENV{PERL_ANYEVENT_VERBOSE}*1;	1259	$ENV{"PERL_ANYEVENT_$_"} = $ENV{"AE_$_"}
		1260	for grep s/^AE_// && !exists $ENV{"PERL_ANYEVENT_$_"}, keys %ENV;
1111		1261
1112	}	1262	@ENV{grep /^PERL_ANYEVENT_/, keys %ENV} = ()
		1263	if ${^TAINT};
1113		1264
1114	our $MAX_SIGNAL_LATENCY = 10;	1265	# $ENV{PERL_ANYEVENT_xxx} now valid
1115		1266
1116	our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred	1267	$VERBOSE = length $ENV{PERL_ANYEVENT_VERBOSE} ? $ENV{PERL_ANYEVENT_VERBOSE}*1 : 4;
1117		1268
1118	{
1119	my $idx;	1269	my $idx;
1120	$PROTOCOL{$_} = ++$idx	1270	$PROTOCOL{$_} = ++$idx
1121	for reverse split /\s*,\s*/,	1271	for reverse split /\s*,\s*/,
1122	$ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";	1272	$ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";
1123	}	1273	}
1124		1274
		1275	our @post_detect;
		1276
		1277	sub post_detect(&) {
		1278	my ($cb) = @_;
		1279
		1280	push @post_detect, $cb;
		1281
		1282	defined wantarray
		1283	? bless \$cb, "AnyEvent::Util::postdetect"
		1284	: ()
		1285	}
		1286
		1287	sub AnyEvent::Util::postdetect::DESTROY {
		1288	@post_detect = grep $_ != ${$_[0]}, @post_detect;
		1289	}
		1290
		1291	our $POSTPONE_W;
		1292	our @POSTPONE;
		1293
		1294	sub _postpone_exec {
		1295	undef $POSTPONE_W;
		1296
		1297	&{ shift @POSTPONE }
		1298	while @POSTPONE;
		1299	}
		1300
		1301	sub postpone(&) {
		1302	push @POSTPONE, shift;
		1303
		1304	$POSTPONE_W ||= AE::timer (0, 0, \&_postpone_exec);
		1305
		1306	()
		1307	}
		1308
		1309	sub log($$;@) {
		1310	# only load the big bloated module when we actually are about to log something
		1311	if ($_[0] <= ($VERBOSE || 1)) { # also catches non-numeric levels(!) and fatal
		1312	local ($!, $@);
		1313	require AnyEvent::Log; # among other things, sets $VERBOSE to 9
		1314	# AnyEvent::Log overwrites this function
		1315	goto &log;
		1316	}
		1317
		1318	0 # not logged
		1319	}
		1320
		1321	sub _logger($;$) {
		1322	my ($level, $renabled) = @_;
		1323
		1324	$$renabled = $level <= $VERBOSE;
		1325
		1326	my $logger = [(caller)[0], $level, $renabled];
		1327
		1328	$AnyEvent::Log::LOGGER{$logger+0} = $logger;
		1329
		1330	# return unless defined wantarray;
		1331	#
		1332	# require AnyEvent::Util;
		1333	# my $guard = AnyEvent::Util::guard (sub {
		1334	# # "clean up"
		1335	# delete $LOGGER{$logger+0};
		1336	# });
		1337	#
		1338	# sub {
		1339	# return 0 unless $$renabled;
		1340	#
		1341	# $guard if 0; # keep guard alive, but don't cause runtime overhead
		1342	# require AnyEvent::Log unless $AnyEvent::Log::VERSION;
		1343	# package AnyEvent::Log;
		1344	# _log ($logger->[0], $level, @_) # logger->[0] has been converted at load time
		1345	# }
		1346	}
		1347
		1348	if (length $ENV{PERL_ANYEVENT_LOG}) {
		1349	require AnyEvent::Log; # AnyEvent::Log does the thing for us
		1350	}
		1351
1125	my @models = (	1352	our @models = (
1126	[EV:: => AnyEvent::Impl::EV:: , 1],	1353	[EV:: => AnyEvent::Impl::EV::],
1127	[Event:: => AnyEvent::Impl::Event::, 1],	1354	[AnyEvent::Loop:: => AnyEvent::Impl::Perl::],
1128	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl:: , 1],
1129	# everything below here will not (normally) be autoprobed	1355	# everything below here will not (normally) be autoprobed
1130	# as the pureperl backend should work everywhere	1356	# as the pure perl backend should work everywhere
1131	# and is usually faster	1357	# and is usually faster
		1358	[Irssi:: => AnyEvent::Impl::Irssi::], # Irssi has a bogus "Event" package, so msut be near the top
		1359	[Event:: => AnyEvent::Impl::Event::], # slow, stable
1132	[Glib:: => AnyEvent::Impl::Glib:: , 1], # becomes extremely slow with many watchers	1360	[Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers
		1361	# everything below here should not be autoloaded
1133	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy	1362	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
1134	[Irssi:: => AnyEvent::Impl::Irssi::], # Irssi has a bogus "Event" package
1135	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles	1363	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
1136	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program	1364	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program
1137	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza	1365	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
1138	[Wx:: => AnyEvent::Impl::POE::],	1366	[Wx:: => AnyEvent::Impl::POE::],
1139	[Prima:: => AnyEvent::Impl::POE::],	1367	[Prima:: => AnyEvent::Impl::POE::],
1140	# IO::Async is just too broken - we would need workarounds for its	1368	[IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # a bitch to autodetect
1141	# byzantine signal and broken child handling, among others.	1369	[Cocoa::EventLoop:: => AnyEvent::Impl::Cocoa::],
1142	# IO::Async is rather hard to detect, as it doesn't have any	1370	[FLTK:: => AnyEvent::Impl::FLTK::],
1143	# obvious default class.
1144	# [0, IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program
1145	# [0, IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program
1146	# [0, IO::Async::Notifier:: => AnyEvent::Impl::IOAsync::], # requires special main program
1147	);	1371	);
1148		1372
1149	our %method = map +($_ => 1),	1373	our @isa_hook;
		1374
		1375	sub _isa_set {
		1376	my @pkg = ("AnyEvent", (map $_->[0], grep defined, @isa_hook), $MODEL);
		1377
		1378	@{"$pkg[$_-1]::ISA"} = $pkg[$_]
		1379	for 1 .. $#pkg;
		1380
		1381	grep $_ && $_->[1], @isa_hook
		1382	and AE::_reset ();
		1383	}
		1384
		1385	# used for hooking AnyEvent::Strict and AnyEvent::Debug::Wrap into the class hierarchy
		1386	sub _isa_hook($$;$) {
		1387	my ($i, $pkg, $reset_ae) = @_;
		1388
		1389	$isa_hook[$i] = $pkg ? [$pkg, $reset_ae] : undef;
		1390
		1391	_isa_set;
		1392	}
		1393
		1394	# all autoloaded methods reserve the complete glob, not just the method slot.
		1395	# due to bugs in perls method cache implementation.
1150	qw(io timer time now now_update signal child idle condvar one_event DESTROY);	1396	our @methods = qw(io timer time now now_update signal child idle condvar);
1151		1397
1152	our @post_detect;
1153
1154	sub post_detect(&) {	1398	sub detect() {
1155	my ($cb) = @_;	1399	return $MODEL if $MODEL; # some programs keep references to detect
1156		1400
1157	if ($MODEL) {	1401	# IO::Async::Loop::AnyEvent is extremely evil, refuse to work with it
1158	$cb->();	1402	# the author knows about the problems and what it does to AnyEvent as a whole
		1403	# (and the ability of others to use AnyEvent), but simply wants to abuse AnyEvent
		1404	# anyway.
		1405	AnyEvent::log fatal => "IO::Async::Loop::AnyEvent detected - that module is broken by\n"
		1406	. "design, abuses internals and breaks AnyEvent - will not continue."
		1407	if exists $INC{"IO/Async/Loop/AnyEvent.pm"};
1159		1408
1160	undef	1409	local $!; # for good measure
		1410	local $SIG{__DIE__}; # we use eval
		1411
		1412	# free some memory
		1413	*detect = sub () { $MODEL };
		1414	# undef &func doesn't correctly update the method cache. grmbl.
		1415	# so we delete the whole glob. grmbl.
		1416	# otoh, perl doesn't let me undef an active usb, but it lets me free
		1417	# a glob with an active sub. hrm. i hope it works, but perl is
		1418	# usually buggy in this department. sigh.
		1419	delete @{"AnyEvent::"}{@methods};
		1420	undef @methods;
		1421
		1422	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z0-9:]+)$/) {
		1423	my $model = $1;
		1424	$model = "AnyEvent::Impl::$model" unless $model =~ s/::$//;
		1425	if (eval "require $model") {
		1426	AnyEvent::log 7 => "Loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.";
		1427	$MODEL = $model;
1161	} else {	1428	} else {
1162	push @post_detect, $cb;	1429	AnyEvent::log 4 => "Unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@";
1163		1430	}
1164	defined wantarray
1165	? bless \$cb, "AnyEvent::Util::postdetect"
1166	: ()
1167	}	1431	}
1168	}
1169		1432
1170	sub AnyEvent::Util::postdetect::DESTROY {	1433	# check for already loaded models
1171	@post_detect = grep $_ != ${$_[0]}, @post_detect;
1172	}
1173
1174	sub detect() {
1175	unless ($MODEL) {	1434	unless ($MODEL) {
1176	local $SIG{__DIE__};	1435	for (@REGISTRY, @models) {
1177		1436	my ($package, $model) = @$_;
1178	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {	1437	if (${"$package\::VERSION"} > 0) {
1179	my $model = "AnyEvent::Impl::$1";
1180	if (eval "require $model") {	1438	if (eval "require $model") {
		1439	AnyEvent::log 7 => "Autodetected model '$model', using it.";
1181	$MODEL = $model;	1440	$MODEL = $model;
1182	warn "AnyEvent: loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.\n" if $VERBOSE >= 2;	1441	last;
1183	} else {	1442	} else {
1184	warn "AnyEvent: unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@" if $VERBOSE;	1443	AnyEvent::log 8 => "Detected event loop $package, but cannot load '$model', skipping: $@";
		1444	}
1185	}	1445	}
1186	}	1446	}
1187		1447
1188	# check for already loaded models
1189	unless ($MODEL) {	1448	unless ($MODEL) {
		1449	# try to autoload a model
1190	for (@REGISTRY, @models) {	1450	for (@REGISTRY, @models) {
1191	my ($package, $model) = @$_;	1451	my ($package, $model) = @$_;
		1452	if (
		1453	eval "require $package"
1192	if (${"$package\::VERSION"} > 0) {	1454	and ${"$package\::VERSION"} > 0
1193	if (eval "require $model") {	1455	and eval "require $model"
		1456	) {
		1457	AnyEvent::log 7 => "Autoloaded model '$model', using it.";
1194	$MODEL = $model;	1458	$MODEL = $model;
1195	warn "AnyEvent: autodetected model '$model', using it.\n" if $VERBOSE >= 2;
1196	last;	1459	last;
1197	}
1198	}	1460	}
1199	}	1461	}
1200		1462
1201	unless ($MODEL) {
1202	# try to autoload a model
1203	for (@REGISTRY, @models) {
1204	my ($package, $model, $autoload) = @$_;
1205	if (
1206	$autoload
1207	and eval "require $package"
1208	and ${"$package\::VERSION"} > 0
1209	and eval "require $model"
1210	) {
1211	$MODEL = $model;
1212	warn "AnyEvent: autoloaded model '$model', using it.\n" if $VERBOSE >= 2;
1213	last;
1214	}
1215	}
1216
1217	$MODEL	1463	$MODEL
1218	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.\n";	1464	or AnyEvent::log fatal => "Backend autodetection failed - did you properly install AnyEvent?";
1219	}
1220	}	1465	}
1221
1222	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
1223
1224	unshift @ISA, $MODEL;
1225
1226	require AnyEvent::Strict if $ENV{PERL_ANYEVENT_STRICT};
1227
1228	(shift @post_detect)->() while @post_detect;
1229	}	1466	}
1230		1467
		1468	# free memory only needed for probing
		1469	undef @models;
		1470	undef @REGISTRY;
		1471
		1472	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
		1473
		1474	# now nuke some methods that are overridden by the backend.
		1475	# SUPER usage is not allowed in these.
		1476	for (qw(time signal child idle)) {
		1477	undef &{"AnyEvent::Base::$_"}
		1478	if defined &{"$MODEL\::$_"};
		1479	}
		1480
		1481	_isa_set;
		1482
		1483	# we're officially open!
		1484
		1485	if ($ENV{PERL_ANYEVENT_STRICT}) {
		1486	require AnyEvent::Strict;
		1487	}
		1488
		1489	if ($ENV{PERL_ANYEVENT_DEBUG_WRAP}) {
		1490	require AnyEvent::Debug;
		1491	AnyEvent::Debug::wrap ($ENV{PERL_ANYEVENT_DEBUG_WRAP});
		1492	}
		1493
		1494	if (length $ENV{PERL_ANYEVENT_DEBUG_SHELL}) {
		1495	require AnyEvent::Socket;
		1496	require AnyEvent::Debug;
		1497
		1498	my $shell = $ENV{PERL_ANYEVENT_DEBUG_SHELL};
		1499	$shell =~ s/\$\$/$$/g;
		1500
		1501	my ($host, $service) = AnyEvent::Socket::parse_hostport ($shell);
		1502	$AnyEvent::Debug::SHELL = AnyEvent::Debug::shell ($host, $service);
		1503	}
		1504
		1505	# now the anyevent environment is set up as the user told us to, so
		1506	# call the actual user code - post detects
		1507
		1508	(shift @post_detect)->() while @post_detect;
		1509	undef @post_detect;
		1510
		1511	*post_detect = sub(&) {
		1512	shift->();
		1513
		1514	undef
		1515	};
		1516
1231	$MODEL	1517	$MODEL
1232	}	1518	}
1233		1519
1234	sub AUTOLOAD {	1520	for my $name (@methods) {
1235	(my $func = $AUTOLOAD) =~ s/.*://;	1521	*$name = sub {
1236		1522	detect;
1237	$method{$func}	1523	# we use goto because
1238	or Carp::croak "$func: not a valid method for AnyEvent objects";	1524	# a) it makes the thunk more transparent
1239		1525	# b) it allows us to delete the thunk later
1240	detect unless $MODEL;	1526	goto &{ UNIVERSAL::can AnyEvent => "SUPER::$name" }
1241		1527	};
1242	my $class = shift;
1243	$class->$func (@_);
1244	}	1528	}
1245		1529
1246	# utility function to dup a filehandle. this is used by many backends	1530	# utility function to dup a filehandle. this is used by many backends
1247	# to support binding more than one watcher per filehandle (they usually	1531	# to support binding more than one watcher per filehandle (they usually
1248	# allow only one watcher per fd, so we dup it to get a different one).	1532	# allow only one watcher per fd, so we dup it to get a different one).
…		…
1258	# we assume CLOEXEC is already set by perl in all important cases	1542	# we assume CLOEXEC is already set by perl in all important cases
1259		1543
1260	($fh2, $rw)	1544	($fh2, $rw)
1261	}	1545	}
1262		1546
		1547	=head1 SIMPLIFIED AE API
		1548
		1549	Starting with version 5.0, AnyEvent officially supports a second, much
		1550	simpler, API that is designed to reduce the calling, typing and memory
		1551	overhead by using function call syntax and a fixed number of parameters.
		1552
		1553	See the L<AE> manpage for details.
		1554
		1555	=cut
		1556
		1557	package AE;
		1558
		1559	our $VERSION = $AnyEvent::VERSION;
		1560
		1561	sub _reset() {
		1562	eval q{
		1563	# fall back to the main API by default - backends and AnyEvent::Base
		1564	# implementations can overwrite these.
		1565
		1566	sub io($$$) {
		1567	AnyEvent->io (fh => $_[0], poll => $_[1] ? "w" : "r", cb => $_[2])
		1568	}
		1569
		1570	sub timer($$$) {
		1571	AnyEvent->timer (after => $_[0], interval => $_[1], cb => $_[2])
		1572	}
		1573
		1574	sub signal($$) {
		1575	AnyEvent->signal (signal => $_[0], cb => $_[1])
		1576	}
		1577
		1578	sub child($$) {
		1579	AnyEvent->child (pid => $_[0], cb => $_[1])
		1580	}
		1581
		1582	sub idle($) {
		1583	AnyEvent->idle (cb => $_[0]);
		1584	}
		1585
		1586	sub cv(;&) {
		1587	AnyEvent->condvar (@_ ? (cb => $_[0]) : ())
		1588	}
		1589
		1590	sub now() {
		1591	AnyEvent->now
		1592	}
		1593
		1594	sub now_update() {
		1595	AnyEvent->now_update
		1596	}
		1597
		1598	sub time() {
		1599	AnyEvent->time
		1600	}
		1601
		1602	*postpone = \&AnyEvent::postpone;
		1603	*log = \&AnyEvent::log;
		1604	};
		1605	die if $@;
		1606	}
		1607
		1608	BEGIN { _reset }
		1609
1263	package AnyEvent::Base;	1610	package AnyEvent::Base;
1264		1611
1265	# default implementations for many methods	1612	# default implementations for many methods
1266		1613
1267	sub _time {	1614	sub time {
		1615	eval q{ # poor man's autoloading {}
1268	# probe for availability of Time::HiRes	1616	# probe for availability of Time::HiRes
1269	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {	1617	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {
1270	warn "AnyEvent: using Time::HiRes for sub-second timing accuracy.\n" if $VERBOSE >= 8;	1618	*time = sub { Time::HiRes::time () };
1271	*_time = \&Time::HiRes::time;	1619	*AE::time = \& Time::HiRes::time ;
		1620	*now = \&time;
		1621	AnyEvent::log 8 => "using Time::HiRes for sub-second timing accuracy.";
1272	# if (eval "use POSIX (); (POSIX::times())...	1622	# if (eval "use POSIX (); (POSIX::times())...
1273	} else {	1623	} else {
1274	warn "AnyEvent: using built-in time(), WARNING, no sub-second resolution!\n" if $VERBOSE;	1624	*time = sub { CORE::time };
1275	*_time = sub { time }; # epic fail	1625	*AE::time = sub (){ CORE::time };
		1626	*now = \&time;
		1627	AnyEvent::log 3 => "Using built-in time(), no sub-second resolution!";
		1628	}
1276	}	1629	};
		1630	die if $@;
1277		1631
1278	&_time	1632	&time
1279	}	1633	}
1280		1634
1281	sub time { _time }	1635	*now = \&time;
1282	sub now { _time }
1283	sub now_update { }	1636	sub now_update { }
1284		1637
		1638	sub _poll {
		1639	Carp::croak "$AnyEvent::MODEL does not support blocking waits. Caught";
		1640	}
		1641
1285	# default implementation for ->condvar	1642	# default implementation for ->condvar
		1643	# in fact, the default should not be overwritten
1286		1644
1287	sub condvar {	1645	sub condvar {
		1646	eval q{ # poor man's autoloading {}
		1647	*condvar = sub {
1288	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"	1648	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"
		1649	};
		1650
		1651	*AE::cv = sub (;&) {
		1652	bless { @_ ? (_ae_cb => shift) : () }, "AnyEvent::CondVar"
		1653	};
		1654	};
		1655	die if $@;
		1656
		1657	&condvar
1289	}	1658	}
1290		1659
1291	# default implementation for ->signal	1660	# default implementation for ->signal
1292		1661
1293	our $HAVE_ASYNC_INTERRUPT;	1662	our $HAVE_ASYNC_INTERRUPT;
		1663
		1664	sub _have_async_interrupt() {
		1665	$HAVE_ASYNC_INTERRUPT = 1*(!$ENV{PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT}
		1666	&& eval "use Async::Interrupt 1.02 (); 1")
		1667	unless defined $HAVE_ASYNC_INTERRUPT;
		1668
		1669	$HAVE_ASYNC_INTERRUPT
		1670	}
		1671
1294	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);	1672	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);
1295	our (%SIG_ASY, %SIG_ASY_W);	1673	our (%SIG_ASY, %SIG_ASY_W);
1296	our ($SIG_COUNT, $SIG_TW);	1674	our ($SIG_COUNT, $SIG_TW);
1297		1675
1298	sub _signal_exec {
1299	$HAVE_ASYNC_INTERRUPT
1300	? $SIGPIPE_R->drain
1301	: sysread $SIGPIPE_R, my $dummy, 9;
1302
1303	while (%SIG_EV) {
1304	for (keys %SIG_EV) {
1305	delete $SIG_EV{$_};
1306	$_->() for values %{ $SIG_CB{$_} || {} };
1307	}
1308	}
1309	}
1310
1311	# install a dumym wakeupw atcher to reduce signal catching latency	1676	# install a dummy wakeup watcher to reduce signal catching latency
		1677	# used by Impls
1312	sub _sig_add() {	1678	sub _sig_add() {
1313	unless ($SIG_COUNT++) {	1679	unless ($SIG_COUNT++) {
1314	# try to align timer on a full-second boundary, if possible	1680	# try to align timer on a full-second boundary, if possible
1315	my $NOW = AnyEvent->now;	1681	my $NOW = AE::now;
1316		1682
1317	$SIG_TW = AnyEvent->timer (	1683	$SIG_TW = AE::timer
1318	after => $MAX_SIGNAL_LATENCY - ($NOW - int $NOW),	1684	$MAX_SIGNAL_LATENCY - ($NOW - int $NOW),
1319	interval => $MAX_SIGNAL_LATENCY,	1685	$MAX_SIGNAL_LATENCY,
1320	cb => sub { }, # just for the PERL_ASYNC_CHECK	1686	sub { } # just for the PERL_ASYNC_CHECK
1321	);	1687	;
1322	}	1688	}
1323	}	1689	}
1324		1690
1325	sub _sig_del {	1691	sub _sig_del {
1326	undef $SIG_TW	1692	undef $SIG_TW
1327	unless --$SIG_COUNT;	1693	unless --$SIG_COUNT;
1328	}	1694	}
1329		1695
		1696	our $_sig_name_init; $_sig_name_init = sub {
		1697	eval q{ # poor man's autoloading {}
		1698	undef $_sig_name_init;
		1699
		1700	if (_have_async_interrupt) {
		1701	*sig2num = \&Async::Interrupt::sig2num;
		1702	*sig2name = \&Async::Interrupt::sig2name;
		1703	} else {
		1704	require Config;
		1705
		1706	my %signame2num;
		1707	@signame2num{ split ' ', $Config::Config{sig_name} }
		1708	= split ' ', $Config::Config{sig_num};
		1709
		1710	my @signum2name;
		1711	@signum2name[values %signame2num] = keys %signame2num;
		1712
		1713	*sig2num = sub($) {
		1714	$_[0] > 0 ? shift : $signame2num{+shift}
		1715	};
		1716	*sig2name = sub ($) {
		1717	$_[0] > 0 ? $signum2name[+shift] : shift
		1718	};
		1719	}
		1720	};
		1721	die if $@;
		1722	};
		1723
		1724	sub sig2num ($) { &$_sig_name_init; &sig2num }
		1725	sub sig2name($) { &$_sig_name_init; &sig2name }
		1726
1330	sub _signal {	1727	sub signal {
1331	my (undef, %arg) = @_;	1728	eval q{ # poor man's autoloading {}
		1729	# probe for availability of Async::Interrupt
		1730	if (_have_async_interrupt) {
		1731	AnyEvent::log 8 => "Using Async::Interrupt for race-free signal handling.";
1332		1732
1333	my $signal = uc $arg{signal}	1733	$SIGPIPE_R = new Async::Interrupt::EventPipe;
1334	or Carp::croak "required option 'signal' is missing";	1734	$SIG_IO = AE::io $SIGPIPE_R->fileno, 0, \&_signal_exec;
1335		1735
1336	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};	1736	} else {
		1737	AnyEvent::log 8 => "Using emulated perl signal handling with latency timer.";
1337		1738
1338	if ($HAVE_ASYNC_INTERRUPT) {	1739	if (AnyEvent::WIN32) {
1339	# async::interrupt	1740	require AnyEvent::Util;
1340		1741
1341	$SIG_ASY{$signal} ||= do {	1742	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
1342	my $asy = new Async::Interrupt	1743	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R, 1) if $SIGPIPE_R;
1343	cb => sub { undef $SIG_EV{$signal} },	1744	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W, 1) if $SIGPIPE_W; # just in case
1344	signal => $signal,	1745	} else {
1345	pipe => [$SIGPIPE_R->filenos],	1746	pipe $SIGPIPE_R, $SIGPIPE_W;
		1747	fcntl $SIGPIPE_R, AnyEvent::F_SETFL, AnyEvent::O_NONBLOCK if $SIGPIPE_R;
		1748	fcntl $SIGPIPE_W, AnyEvent::F_SETFL, AnyEvent::O_NONBLOCK if $SIGPIPE_W; # just in case
		1749
		1750	# not strictly required, as $^F is normally 2, but let's make sure...
		1751	fcntl $SIGPIPE_R, AnyEvent::F_SETFD, AnyEvent::FD_CLOEXEC;
		1752	fcntl $SIGPIPE_W, AnyEvent::F_SETFD, AnyEvent::FD_CLOEXEC;
1346	;	1753	}
1347	$asy->pipe_autodrain (0);
1348		1754
1349	$asy	1755	$SIGPIPE_R
		1756	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";
		1757
		1758	$SIG_IO = AE::io $SIGPIPE_R, 0, \&_signal_exec;
		1759	}
		1760
		1761	*signal = $HAVE_ASYNC_INTERRUPT
		1762	? sub {
		1763	my (undef, %arg) = @_;
		1764
		1765	# async::interrupt
		1766	my $signal = sig2num $arg{signal};
		1767	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
		1768
		1769	$SIG_ASY{$signal} ||= new Async::Interrupt
		1770	cb => sub { undef $SIG_EV{$signal} },
		1771	signal => $signal,
		1772	pipe => [$SIGPIPE_R->filenos],
		1773	pipe_autodrain => 0,
		1774	;
		1775
		1776	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
		1777	}
		1778	: sub {
		1779	my (undef, %arg) = @_;
		1780
		1781	# pure perl
		1782	my $signal = sig2name $arg{signal};
		1783	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
		1784
		1785	$SIG{$signal} ||= sub {
		1786	local $!;
		1787	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;
		1788	undef $SIG_EV{$signal};
		1789	};
		1790
		1791	# can't do signal processing without introducing races in pure perl,
		1792	# so limit the signal latency.
		1793	_sig_add;
		1794
		1795	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
		1796	}
		1797	;
		1798
		1799	*AnyEvent::Base::signal::DESTROY = sub {
		1800	my ($signal, $cb) = @{$_[0]};
		1801
		1802	_sig_del;
		1803
		1804	delete $SIG_CB{$signal}{$cb};
		1805
		1806	$HAVE_ASYNC_INTERRUPT
		1807	? delete $SIG_ASY{$signal}
		1808	: # delete doesn't work with older perls - they then
		1809	# print weird messages, or just unconditionally exit
		1810	# instead of getting the default action.
		1811	undef $SIG{$signal}
		1812	unless keys %{ $SIG_CB{$signal} };
1350	};	1813	};
1351		1814
1352	} else {	1815	*_signal_exec = sub {
1353	# pure perl	1816	$HAVE_ASYNC_INTERRUPT
		1817	? $SIGPIPE_R->drain
		1818	: sysread $SIGPIPE_R, (my $dummy), 9;
1354		1819
1355	$SIG{$signal} ||= sub {	1820	while (%SIG_EV) {
1356	local $!;	1821	for (keys %SIG_EV) {
1357	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;	1822	delete $SIG_EV{$_};
1358	undef $SIG_EV{$signal};	1823	&$_ for values %{ $SIG_CB{$_} || {} };
		1824	}
		1825	}
1359	};	1826	};
1360
1361	# can't do signal processing without introducing races in pure perl,
1362	# so limit the signal latency.
1363	_sig_add;
1364	}	1827	};
		1828	die if $@;
1365		1829
1366	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
1367	}
1368
1369	sub signal {
1370	# probe for availability of Async::Interrupt
1371	if (!$ENV{PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT} && eval "use Async::Interrupt 0.6 (); 1") {
1372	warn "AnyEvent: using Async::Interrupt for race-free signal handling.\n" if $VERBOSE >= 8;
1373
1374	$HAVE_ASYNC_INTERRUPT = 1;
1375	$SIGPIPE_R = new Async::Interrupt::EventPipe;
1376	$SIG_IO = AnyEvent->io (fh => $SIGPIPE_R->fileno, poll => "r", cb => \&_signal_exec);
1377
1378	} else {
1379	warn "AnyEvent: using emulated perl signal handling with latency timer.\n" if $VERBOSE >= 8;
1380
1381	require Fcntl;
1382
1383	if (AnyEvent::WIN32) {
1384	require AnyEvent::Util;
1385
1386	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
1387	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R) if $SIGPIPE_R;
1388	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W) if $SIGPIPE_W; # just in case
1389	} else {
1390	pipe $SIGPIPE_R, $SIGPIPE_W;
1391	fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R;
1392	fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case
1393
1394	# not strictly required, as $^F is normally 2, but let's make sure...
1395	fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
1396	fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
1397	}
1398
1399	$SIGPIPE_R
1400	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";
1401
1402	$SIG_IO = AnyEvent->io (fh => $SIGPIPE_R, poll => "r", cb => \&_signal_exec);
1403	}
1404
1405	*signal = \&_signal;
1406	&signal	1830	&signal
1407	}
1408
1409	sub AnyEvent::Base::signal::DESTROY {
1410	my ($signal, $cb) = @{$_[0]};
1411
1412	_sig_del;
1413
1414	delete $SIG_CB{$signal}{$cb};
1415
1416	$HAVE_ASYNC_INTERRUPT
1417	? delete $SIG_ASY{$signal}
1418	: # delete doesn't work with older perls - they then
1419	# print weird messages, or just unconditionally exit
1420	# instead of getting the default action.
1421	undef $SIG{$signal}
1422	unless keys %{ $SIG_CB{$signal} };
1423	}	1831	}
1424		1832
1425	# default implementation for ->child	1833	# default implementation for ->child
1426		1834
1427	our %PID_CB;	1835	our %PID_CB;
1428	our $CHLD_W;	1836	our $CHLD_W;
1429	our $CHLD_DELAY_W;	1837	our $CHLD_DELAY_W;
1430	our $WNOHANG;
1431		1838
		1839	# used by many Impl's
1432	sub _emit_childstatus($$) {	1840	sub _emit_childstatus($$) {
1433	my (undef, $rpid, $rstatus) = @_;	1841	my (undef, $rpid, $rstatus) = @_;
1434		1842
1435	$_->($rpid, $rstatus)	1843	$_->($rpid, $rstatus)
1436	for values %{ $PID_CB{$rpid} || {} },	1844	for values %{ $PID_CB{$rpid} || {} },
1437	values %{ $PID_CB{0} || {} };	1845	values %{ $PID_CB{0} || {} };
1438	}	1846	}
1439		1847
1440	sub _sigchld {
1441	my $pid;
1442
1443	AnyEvent->_emit_childstatus ($pid, $?)
1444	while ($pid = waitpid -1, $WNOHANG) > 0;
1445	}
1446
1447	sub child {	1848	sub child {
		1849	eval q{ # poor man's autoloading {}
		1850	*_sigchld = sub {
		1851	my $pid;
		1852
		1853	AnyEvent->_emit_childstatus ($pid, $?)
		1854	while ($pid = waitpid -1, WNOHANG) > 0;
		1855	};
		1856
		1857	*child = sub {
1448	my (undef, %arg) = @_;	1858	my (undef, %arg) = @_;
1449		1859
1450	defined (my $pid = $arg{pid} + 0)	1860	my $pid = $arg{pid};
1451	or Carp::croak "required option 'pid' is missing";	1861	my $cb = $arg{cb};
1452		1862
1453	$PID_CB{$pid}{$arg{cb}} = $arg{cb};	1863	$PID_CB{$pid}{$cb+0} = $cb;
1454		1864
1455	# WNOHANG is almost cetrainly 1 everywhere
1456	$WNOHANG ||= $^O =~ /^(?:openbsd|netbsd|linux|freebsd|cygwin|MSWin32)$/
1457	? 1
1458	: eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1;
1459
1460	unless ($CHLD_W) {	1865	unless ($CHLD_W) {
1461	$CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld);	1866	$CHLD_W = AE::signal CHLD => \&_sigchld;
1462	# child could be a zombie already, so make at least one round	1867	# child could be a zombie already, so make at least one round
1463	&_sigchld;	1868	&_sigchld;
1464	}	1869	}
1465		1870
1466	bless [$pid, $arg{cb}], "AnyEvent::Base::child"	1871	bless [$pid, $cb+0], "AnyEvent::Base::child"
1467	}	1872	};
1468		1873
1469	sub AnyEvent::Base::child::DESTROY {	1874	*AnyEvent::Base::child::DESTROY = sub {
1470	my ($pid, $cb) = @{$_[0]};	1875	my ($pid, $icb) = @{$_[0]};
1471		1876
1472	delete $PID_CB{$pid}{$cb};	1877	delete $PID_CB{$pid}{$icb};
1473	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };	1878	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };
1474		1879
1475	undef $CHLD_W unless keys %PID_CB;	1880	undef $CHLD_W unless keys %PID_CB;
		1881	};
		1882	};
		1883	die if $@;
		1884
		1885	&child
1476	}	1886	}
1477		1887
1478	# idle emulation is done by simply using a timer, regardless	1888	# idle emulation is done by simply using a timer, regardless
1479	# of whether the process is idle or not, and not letting	1889	# of whether the process is idle or not, and not letting
1480	# the callback use more than 50% of the time.	1890	# the callback use more than 50% of the time.
1481	sub idle {	1891	sub idle {
		1892	eval q{ # poor man's autoloading {}
		1893	*idle = sub {
1482	my (undef, %arg) = @_;	1894	my (undef, %arg) = @_;
1483		1895
1484	my ($cb, $w, $rcb) = $arg{cb};	1896	my ($cb, $w, $rcb) = $arg{cb};
1485		1897
1486	$rcb = sub {	1898	$rcb = sub {
1487	if ($cb) {	1899	if ($cb) {
1488	$w = _time;	1900	$w = AE::time;
1489	&$cb;	1901	&$cb;
1490	$w = _time - $w;	1902	$w = AE::time - $w;
1491		1903
1492	# never use more then 50% of the time for the idle watcher,	1904	# never use more then 50% of the time for the idle watcher,
1493	# within some limits	1905	# within some limits
1494	$w = 0.0001 if $w < 0.0001;	1906	$w = 0.0001 if $w < 0.0001;
1495	$w = 5 if $w > 5;	1907	$w = 5 if $w > 5;
1496		1908
1497	$w = AnyEvent->timer (after => $w, cb => $rcb);	1909	$w = AE::timer $w, 0, $rcb;
1498	} else {	1910	} else {
1499	# clean up...	1911	# clean up...
1500	undef $w;	1912	undef $w;
1501	undef $rcb;	1913	undef $rcb;
		1914	}
		1915	};
		1916
		1917	$w = AE::timer 0.05, 0, $rcb;
		1918
		1919	bless \\$cb, "AnyEvent::Base::idle"
1502	}	1920	};
		1921
		1922	*AnyEvent::Base::idle::DESTROY = sub {
		1923	undef $${$_[0]};
		1924	};
1503	};	1925	};
		1926	die if $@;
1504		1927
1505	$w = AnyEvent->timer (after => 0.05, cb => $rcb);	1928	&idle
1506
1507	bless \\$cb, "AnyEvent::Base::idle"
1508	}
1509
1510	sub AnyEvent::Base::idle::DESTROY {
1511	undef $${$_[0]};
1512	}	1929	}
1513		1930
1514	package AnyEvent::CondVar;	1931	package AnyEvent::CondVar;
1515		1932
1516	our @ISA = AnyEvent::CondVar::Base::;	1933	our @ISA = AnyEvent::CondVar::Base::;
		1934
		1935	# only to be used for subclassing
		1936	sub new {
		1937	my $class = shift;
		1938	bless AnyEvent->condvar (@_), $class
		1939	}
1517		1940
1518	package AnyEvent::CondVar::Base;	1941	package AnyEvent::CondVar::Base;
1519		1942
1520	#use overload	1943	#use overload
1521	# '&{}' => sub { my $self = shift; sub { $self->send (@_) } },	1944	# '&{}' => sub { my $self = shift; sub { $self->send (@_) } },
…		…
1531		1954
1532	sub _send {	1955	sub _send {
1533	# nop	1956	# nop
1534	}	1957	}
1535		1958
		1959	sub _wait {
		1960	AnyEvent->_poll until $_[0]{_ae_sent};
		1961	}
		1962
1536	sub send {	1963	sub send {
1537	my $cv = shift;	1964	my $cv = shift;
1538	$cv->{_ae_sent} = [@_];	1965	$cv->{_ae_sent} = [@_];
1539	(delete $cv->{_ae_cb})->($cv) if $cv->{_ae_cb};	1966	(delete $cv->{_ae_cb})->($cv) if $cv->{_ae_cb};
1540	$cv->_send;	1967	$cv->_send;
…		…
1547		1974
1548	sub ready {	1975	sub ready {
1549	$_[0]{_ae_sent}	1976	$_[0]{_ae_sent}
1550	}	1977	}
1551		1978
1552	sub _wait {
1553	$WAITING
1554	and !$_[0]{_ae_sent}
1555	and Carp::croak "AnyEvent::CondVar: recursive blocking wait detected";
1556
1557	local $WAITING = 1;
1558	AnyEvent->one_event while !$_[0]{_ae_sent};
1559	}
1560
1561	sub recv {	1979	sub recv {
		1980	unless ($_[0]{_ae_sent}) {
		1981	$WAITING
		1982	and Carp::croak "AnyEvent::CondVar: recursive blocking wait attempted";
		1983
		1984	local $WAITING = 1;
1562	$_[0]->_wait;	1985	$_[0]->_wait;
		1986	}
1563		1987
1564	Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak};	1988	$_[0]{_ae_croak}
1565	wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0]	1989	and Carp::croak $_[0]{_ae_croak};
		1990
		1991	wantarray
		1992	? @{ $_[0]{_ae_sent} }
		1993	: $_[0]{_ae_sent}[0]
1566	}	1994	}
1567		1995
1568	sub cb {	1996	sub cb {
1569	$_[0]{_ae_cb} = $_[1] if @_ > 1;	1997	my $cv = shift;
		1998
		1999	@_
		2000	and $cv->{_ae_cb} = shift
		2001	and $cv->{_ae_sent}
		2002	and (delete $cv->{_ae_cb})->($cv);
		2003
1570	$_[0]{_ae_cb}	2004	$cv->{_ae_cb}
1571	}	2005	}
1572		2006
1573	sub begin {	2007	sub begin {
1574	++$_[0]{_ae_counter};	2008	++$_[0]{_ae_counter};
1575	$_[0]{_ae_end_cb} = $_[1] if @_ > 1;	2009	$_[0]{_ae_end_cb} = $_[1] if @_ > 1;
…		…
1580	&{ $_[0]{_ae_end_cb} || sub { $_[0]->send } };	2014	&{ $_[0]{_ae_end_cb} || sub { $_[0]->send } };
1581	}	2015	}
1582		2016
1583	# undocumented/compatibility with pre-3.4	2017	# undocumented/compatibility with pre-3.4
1584	*broadcast = \&send;	2018	*broadcast = \&send;
1585	*wait = \&_wait;	2019	*wait = \&recv;
1586		2020
1587	=head1 ERROR AND EXCEPTION HANDLING	2021	=head1 ERROR AND EXCEPTION HANDLING
1588		2022
1589	In general, AnyEvent does not do any error handling - it relies on the	2023	In general, AnyEvent does not do any error handling - it relies on the
1590	caller to do that if required. The L<AnyEvent::Strict> module (see also	2024	caller to do that if required. The L<AnyEvent::Strict> module (see also
…		…
1602	$Event/EV::DIED->() >>, L<Glib> uses C<< install_exception_handler >> and	2036	$Event/EV::DIED->() >>, L<Glib> uses C<< install_exception_handler >> and
1603	so on.	2037	so on.
1604		2038
1605	=head1 ENVIRONMENT VARIABLES	2039	=head1 ENVIRONMENT VARIABLES
1606		2040
1607	The following environment variables are used by this module or its	2041	AnyEvent supports a number of environment variables that tune the
1608	submodules.	2042	runtime behaviour. They are usually evaluated when AnyEvent is
		2043	loaded, initialised, or a submodule that uses them is loaded. Many of
		2044	them also cause AnyEvent to load additional modules - for example,
		2045	C<PERL_ANYEVENT_DEBUG_WRAP> causes the L<AnyEvent::Debug> module to be
		2046	loaded.
1609		2047
1610	Note that AnyEvent will remove I<all> environment variables starting with	2048	All the environment variables documented here start with
1611	C<PERL_ANYEVENT_> from C<%ENV> when it is loaded while taint mode is	2049	C<PERL_ANYEVENT_>, which is what AnyEvent considers its own
1612	enabled.	2050	namespace. Other modules are encouraged (but by no means required) to use
		2051	C<PERL_ANYEVENT_SUBMODULE> if they have registered the AnyEvent::Submodule
		2052	namespace on CPAN, for any submodule. For example, L<AnyEvent::HTTP> could
		2053	be expected to use C<PERL_ANYEVENT_HTTP_PROXY> (it should not access env
		2054	variables starting with C<AE_>, see below).
		2055
		2056	All variables can also be set via the C<AE_> prefix, that is, instead
		2057	of setting C<PERL_ANYEVENT_VERBOSE> you can also set C<AE_VERBOSE>. In
		2058	case there is a clash btween anyevent and another program that uses
		2059	C<AE_something> you can set the corresponding C<PERL_ANYEVENT_something>
		2060	variable to the empty string, as those variables take precedence.
		2061
		2062	When AnyEvent is first loaded, it copies all C<AE_xxx> env variables
		2063	to their C<PERL_ANYEVENT_xxx> counterpart unless that variable already
		2064	exists. If taint mode is on, then AnyEvent will remove I<all> environment
		2065	variables starting with C<PERL_ANYEVENT_> from C<%ENV> (or replace them
		2066	with C<undef> or the empty string, if the corresaponding C<AE_> variable
		2067	is set).
		2068
		2069	The exact algorithm is currently:
		2070
		2071	1. if taint mode enabled, delete all PERL_ANYEVENT_xyz variables from %ENV
		2072	2. copy over AE_xyz to PERL_ANYEVENT_xyz unless the latter alraedy exists
		2073	3. if taint mode enabled, set all PERL_ANYEVENT_xyz variables to undef.
		2074
		2075	This ensures that child processes will not see the C<AE_> variables.
		2076
		2077	The following environment variables are currently known to AnyEvent:
1613		2078
1614	=over 4	2079	=over 4
1615		2080
1616	=item C<PERL_ANYEVENT_VERBOSE>	2081	=item C<PERL_ANYEVENT_VERBOSE>
1617		2082
1618	By default, AnyEvent will be completely silent except in fatal	2083	By default, AnyEvent will log messages with loglevel C<4> (C<error>) or
1619	conditions. You can set this environment variable to make AnyEvent more	2084	higher (see L<AnyEvent::Log>). You can set this environment variable to a
1620	talkative.	2085	numerical loglevel to make AnyEvent more (or less) talkative.
1621		2086
		2087	If you want to do more than just set the global logging level
		2088	you should have a look at C<PERL_ANYEVENT_LOG>, which allows much more
		2089	complex specifications.
		2090
		2091	When set to C<0> (C<off>), then no messages whatsoever will be logged with
		2092	everything else at defaults.
		2093
1622	When set to C<1> or higher, causes AnyEvent to warn about unexpected	2094	When set to C<5> or higher (C<warn>), AnyEvent warns about unexpected
1623	conditions, such as not being able to load the event model specified by	2095	conditions, such as not being able to load the event model specified by
1624	C<PERL_ANYEVENT_MODEL>.	2096	C<PERL_ANYEVENT_MODEL>, or a guard callback throwing an exception - this
		2097	is the minimum recommended level for use during development.
1625		2098
1626	When set to C<2> or higher, cause AnyEvent to report to STDERR which event	2099	When set to C<7> or higher (info), AnyEvent reports which event model it
1627	model it chooses.	2100	chooses.
1628		2101
1629	When set to C<8> or higher, then AnyEvent will report extra information on	2102	When set to C<8> or higher (debug), then AnyEvent will report extra
1630	which optional modules it loads and how it implements certain features.	2103	information on which optional modules it loads and how it implements
		2104	certain features.
		2105
		2106	=item C<PERL_ANYEVENT_LOG>
		2107
		2108	Accepts rather complex logging specifications. For example, you could log
		2109	all C<debug> messages of some module to stderr, warnings and above to
		2110	stderr, and errors and above to syslog, with:
		2111
		2112	PERL_ANYEVENT_LOG=Some::Module=debug,+log:filter=warn,+%syslog:%syslog=error,syslog
		2113
		2114	For the rather extensive details, see L<AnyEvent::Log>.
		2115
		2116	This variable is evaluated when AnyEvent (or L<AnyEvent::Log>) is loaded,
		2117	so will take effect even before AnyEvent has initialised itself.
		2118
		2119	Note that specifying this environment variable causes the L<AnyEvent::Log>
		2120	module to be loaded, while C<PERL_ANYEVENT_VERBOSE> does not, so only
		2121	using the latter saves a few hundred kB of memory unless a module
		2122	explicitly needs the extra features of AnyEvent::Log.
1631		2123
1632	=item C<PERL_ANYEVENT_STRICT>	2124	=item C<PERL_ANYEVENT_STRICT>
1633		2125
1634	AnyEvent does not do much argument checking by default, as thorough	2126	AnyEvent does not do much argument checking by default, as thorough
1635	argument checking is very costly. Setting this variable to a true value	2127	argument checking is very costly. Setting this variable to a true value
…		…
1637	check the arguments passed to most method calls. If it finds any problems,	2129	check the arguments passed to most method calls. If it finds any problems,
1638	it will croak.	2130	it will croak.
1639		2131
1640	In other words, enables "strict" mode.	2132	In other words, enables "strict" mode.
1641		2133
1642	Unlike C<use strict> (or it's modern cousin, C<< use L<common::sense>	2134	Unlike C<use strict> (or its modern cousin, C<< use L<common::sense>
1643	>>, it is definitely recommended to keep it off in production. Keeping	2135	>>, it is definitely recommended to keep it off in production. Keeping
1644	C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs	2136	C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs
1645	can be very useful, however.	2137	can be very useful, however.
1646		2138
		2139	=item C<PERL_ANYEVENT_DEBUG_SHELL>
		2140
		2141	If this env variable is nonempty, then its contents will be interpreted by
		2142	C<AnyEvent::Socket::parse_hostport> and C<AnyEvent::Debug::shell> (after
		2143	replacing every occurance of C<$$> by the process pid). The shell object
		2144	is saved in C<$AnyEvent::Debug::SHELL>.
		2145
		2146	This happens when the first watcher is created.
		2147
		2148	For example, to bind a debug shell on a unix domain socket in
		2149	F<< /tmp/debug<pid>.sock >>, you could use this:
		2150
		2151	PERL_ANYEVENT_DEBUG_SHELL=/tmp/debug\$\$.sock perlprog
		2152	# connect with e.g.: socat readline /tmp/debug123.sock
		2153
		2154	Or to bind to tcp port 4545 on localhost:
		2155
		2156	PERL_ANYEVENT_DEBUG_SHELL=127.0.0.1:4545 perlprog
		2157	# connect with e.g.: telnet localhost 4545
		2158
		2159	Note that creating sockets in F</tmp> or on localhost is very unsafe on
		2160	multiuser systems.
		2161
		2162	=item C<PERL_ANYEVENT_DEBUG_WRAP>
		2163
		2164	Can be set to C<0>, C<1> or C<2> and enables wrapping of all watchers for
		2165	debugging purposes. See C<AnyEvent::Debug::wrap> for details.
		2166
1647	=item C<PERL_ANYEVENT_MODEL>	2167	=item C<PERL_ANYEVENT_MODEL>
1648		2168
1649	This can be used to specify the event model to be used by AnyEvent, before	2169	This can be used to specify the event model to be used by AnyEvent, before
1650	auto detection and -probing kicks in. It must be a string consisting	2170	auto detection and -probing kicks in.
1651	entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended	2171
		2172	It normally is a string consisting entirely of ASCII letters (e.g. C<EV>
		2173	or C<IOAsync>). The string C<AnyEvent::Impl::> gets prepended and the
1652	and the resulting module name is loaded and if the load was successful,	2174	resulting module name is loaded and - if the load was successful - used as
1653	used as event model. If it fails to load AnyEvent will proceed with	2175	event model backend. If it fails to load then AnyEvent will proceed with
1654	auto detection and -probing.	2176	auto detection and -probing.
1655		2177
1656	This functionality might change in future versions.	2178	If the string ends with C<::> instead (e.g. C<AnyEvent::Impl::EV::>) then
		2179	nothing gets prepended and the module name is used as-is (hint: C<::> at
		2180	the end of a string designates a module name and quotes it appropriately).
1657		2181
1658	For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you	2182	For example, to force the pure perl model (L<AnyEvent::Loop::Perl>) you
1659	could start your program like this:	2183	could start your program like this:
1660		2184
1661	PERL_ANYEVENT_MODEL=Perl perl ...	2185	PERL_ANYEVENT_MODEL=Perl perl ...
		2186
		2187	=item C<PERL_ANYEVENT_IO_MODEL>
		2188
		2189	The current file I/O model - see L<AnyEvent::IO> for more info.
		2190
		2191	At the moment, only C<Perl> (small, pure-perl, synchronous) and
		2192	C<IOAIO> (truly asynchronous) are supported. The default is C<IOAIO> if
		2193	L<AnyEvent::AIO> can be loaded, otherwise it is C<Perl>.
1662		2194
1663	=item C<PERL_ANYEVENT_PROTOCOLS>	2195	=item C<PERL_ANYEVENT_PROTOCOLS>
1664		2196
1665	Used by both L<AnyEvent::DNS> and L<AnyEvent::Socket> to determine preferences	2197	Used by both L<AnyEvent::DNS> and L<AnyEvent::Socket> to determine preferences
1666	for IPv4 or IPv6. The default is unspecified (and might change, or be the result	2198	for IPv4 or IPv6. The default is unspecified (and might change, or be the result
…		…
1679	but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4>	2211	but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4>
1680	- only support IPv4, never try to resolve or contact IPv6	2212	- only support IPv4, never try to resolve or contact IPv6
1681	addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or	2213	addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or
1682	IPv6, but prefer IPv6 over IPv4.	2214	IPv6, but prefer IPv6 over IPv4.
1683		2215
		2216	=item C<PERL_ANYEVENT_HOSTS>
		2217
		2218	This variable, if specified, overrides the F</etc/hosts> file used by
		2219	L<AnyEvent::Socket>C<::resolve_sockaddr>, i.e. hosts aliases will be read
		2220	from that file instead.
		2221
1684	=item C<PERL_ANYEVENT_EDNS0>	2222	=item C<PERL_ANYEVENT_EDNS0>
1685		2223
1686	Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension	2224	Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension for
1687	for DNS. This extension is generally useful to reduce DNS traffic, but	2225	DNS. This extension is generally useful to reduce DNS traffic, especially
1688	some (broken) firewalls drop such DNS packets, which is why it is off by	2226	when DNSSEC is involved, but some (broken) firewalls drop such DNS
1689	default.	2227	packets, which is why it is off by default.
1690		2228
1691	Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce	2229	Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce
1692	EDNS0 in its DNS requests.	2230	EDNS0 in its DNS requests.
1693		2231
1694	=item C<PERL_ANYEVENT_MAX_FORKS>	2232	=item C<PERL_ANYEVENT_MAX_FORKS>
…		…
1700		2238
1701	The default value for the C<max_outstanding> parameter for the default DNS	2239	The default value for the C<max_outstanding> parameter for the default DNS
1702	resolver - this is the maximum number of parallel DNS requests that are	2240	resolver - this is the maximum number of parallel DNS requests that are
1703	sent to the DNS server.	2241	sent to the DNS server.
1704		2242
		2243	=item C<PERL_ANYEVENT_MAX_SIGNAL_LATENCY>
		2244
		2245	Perl has inherently racy signal handling (you can basically choose between
		2246	losing signals and memory corruption) - pure perl event loops (including
		2247	C<AnyEvent::Loop>, when C<Async::Interrupt> isn't available) therefore
		2248	have to poll regularly to avoid losing signals.
		2249
		2250	Some event loops are racy, but don't poll regularly, and some event loops
		2251	are written in C but are still racy. For those event loops, AnyEvent
		2252	installs a timer that regularly wakes up the event loop.
		2253
		2254	By default, the interval for this timer is C<10> seconds, but you can
		2255	override this delay with this environment variable (or by setting
		2256	the C<$AnyEvent::MAX_SIGNAL_LATENCY> variable before creating signal
		2257	watchers).
		2258
		2259	Lower values increase CPU (and energy) usage, higher values can introduce
		2260	long delays when reaping children or waiting for signals.
		2261
		2262	The L<AnyEvent::Async> module, if available, will be used to avoid this
		2263	polling (with most event loops).
		2264
1705	=item C<PERL_ANYEVENT_RESOLV_CONF>	2265	=item C<PERL_ANYEVENT_RESOLV_CONF>
1706		2266
1707	The file to use instead of F</etc/resolv.conf> (or OS-specific	2267	The absolute path to a F<resolv.conf>-style file to use instead of
1708	configuration) in the default resolver. When set to the empty string, no	2268	F</etc/resolv.conf> (or the OS-specific configuration) in the default
1709	default config will be used.	2269	resolver, or the empty string to select the default configuration.
1710		2270
1711	=item C<PERL_ANYEVENT_CA_FILE>, C<PERL_ANYEVENT_CA_PATH>.	2271	=item C<PERL_ANYEVENT_CA_FILE>, C<PERL_ANYEVENT_CA_PATH>.
1712		2272
1713	When neither C<ca_file> nor C<ca_path> was specified during	2273	When neither C<ca_file> nor C<ca_path> was specified during
1714	L<AnyEvent::TLS> context creation, and either of these environment	2274	L<AnyEvent::TLS> context creation, and either of these environment
1715	variables exist, they will be used to specify CA certificate locations	2275	variables are nonempty, they will be used to specify CA certificate
1716	instead of a system-dependent default.	2276	locations instead of a system-dependent default.
1717		2277
1718	=item C<PERL_ANYEVENT_AVOID_GUARD> and C<PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT>	2278	=item C<PERL_ANYEVENT_AVOID_GUARD> and C<PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT>
1719		2279
1720	When these are set to C<1>, then the respective modules are not	2280	When these are set to C<1>, then the respective modules are not
1721	loaded. Mostly good for testing AnyEvent itself.	2281	loaded. Mostly good for testing AnyEvent itself.
…		…
1784	warn "read: $input\n"; # output what has been read	2344	warn "read: $input\n"; # output what has been read
1785	$cv->send if $input =~ /^q/i; # quit program if /^q/i	2345	$cv->send if $input =~ /^q/i; # quit program if /^q/i
1786	},	2346	},
1787	);	2347	);
1788		2348
1789	my $time_watcher; # can only be used once
1790
1791	sub new_timer {
1792	$timer = AnyEvent->timer (after => 1, cb => sub {	2349	my $time_watcher = AnyEvent->timer (after => 1, interval => 1, cb => sub {
1793	warn "timeout\n"; # print 'timeout' about every second	2350	warn "timeout\n"; # print 'timeout' at most every second
1794	&new_timer; # and restart the time
1795	});	2351	});
1796	}
1797
1798	new_timer; # create first timer
1799		2352
1800	$cv->recv; # wait until user enters /^q/i	2353	$cv->recv; # wait until user enters /^q/i
1801		2354
1802	=head1 REAL-WORLD EXAMPLE	2355	=head1 REAL-WORLD EXAMPLE
1803		2356
…		…
1876		2429
1877	The actual code goes further and collects all errors (C<die>s, exceptions)	2430	The actual code goes further and collects all errors (C<die>s, exceptions)
1878	that occurred during request processing. The C<result> method detects	2431	that occurred during request processing. The C<result> method detects
1879	whether an exception as thrown (it is stored inside the $txn object)	2432	whether an exception as thrown (it is stored inside the $txn object)
1880	and just throws the exception, which means connection errors and other	2433	and just throws the exception, which means connection errors and other
1881	problems get reported tot he code that tries to use the result, not in a	2434	problems get reported to the code that tries to use the result, not in a
1882	random callback.	2435	random callback.
1883		2436
1884	All of this enables the following usage styles:	2437	All of this enables the following usage styles:
1885		2438
1886	1. Blocking:	2439	1. Blocking:
…		…
1934	through AnyEvent. The benchmark creates a lot of timers (with a zero	2487	through AnyEvent. The benchmark creates a lot of timers (with a zero
1935	timeout) and I/O watchers (watching STDOUT, a pty, to become writable,	2488	timeout) and I/O watchers (watching STDOUT, a pty, to become writable,
1936	which it is), lets them fire exactly once and destroys them again.	2489	which it is), lets them fire exactly once and destroys them again.
1937		2490
1938	Source code for this benchmark is found as F<eg/bench> in the AnyEvent	2491	Source code for this benchmark is found as F<eg/bench> in the AnyEvent
1939	distribution.	2492	distribution. It uses the L<AE> interface, which makes a real difference
		2493	for the EV and Perl backends only.
1940		2494
1941	=head3 Explanation of the columns	2495	=head3 Explanation of the columns
1942		2496
1943	I<watcher> is the number of event watchers created/destroyed. Since	2497	I<watcher> is the number of event watchers created/destroyed. Since
1944	different event models feature vastly different performances, each event	2498	different event models feature vastly different performances, each event
…		…
1965	watcher.	2519	watcher.
1966		2520
1967	=head3 Results	2521	=head3 Results
1968		2522
1969	name watchers bytes create invoke destroy comment	2523	name watchers bytes create invoke destroy comment
1970	EV/EV 400000 224 0.47 0.35 0.27 EV native interface	2524	EV/EV 100000 223 0.47 0.43 0.27 EV native interface
1971	EV/Any 100000 224 2.88 0.34 0.27 EV + AnyEvent watchers	2525	EV/Any 100000 223 0.48 0.42 0.26 EV + AnyEvent watchers
1972	CoroEV/Any 100000 224 2.85 0.35 0.28 coroutines + Coro::Signal	2526	Coro::EV/Any 100000 223 0.47 0.42 0.26 coroutines + Coro::Signal
1973	Perl/Any 100000 452 4.13 0.73 0.95 pure perl implementation	2527	Perl/Any 100000 431 2.70 0.74 0.92 pure perl implementation
1974	Event/Event 16000 517 32.20 31.80 0.81 Event native interface	2528	Event/Event 16000 516 31.16 31.84 0.82 Event native interface
1975	Event/Any 16000 590 35.85 31.55 1.06 Event + AnyEvent watchers	2529	Event/Any 16000 1203 42.61 34.79 1.80 Event + AnyEvent watchers
1976	IOAsync/Any 16000 989 38.10 32.77 11.13 via IO::Async::Loop::IO_Poll	2530	IOAsync/Any 16000 1911 41.92 27.45 16.81 via IO::Async::Loop::IO_Poll
1977	IOAsync/Any 16000 990 37.59 29.50 10.61 via IO::Async::Loop::Epoll	2531	IOAsync/Any 16000 1726 40.69 26.37 15.25 via IO::Async::Loop::Epoll
1978	Glib/Any 16000 1357 102.33 12.31 51.00 quadratic behaviour	2532	Glib/Any 16000 1118 89.00 12.57 51.17 quadratic behaviour
1979	Tk/Any 2000 1860 27.20 66.31 14.00 SEGV with >> 2000 watchers	2533	Tk/Any 2000 1346 20.96 10.75 8.00 SEGV with >> 2000 watchers
1980	POE/Event 2000 6328 109.99 751.67 14.02 via POE::Loop::Event	2534	POE/Any 2000 6951 108.97 795.32 14.24 via POE::Loop::Event
1981	POE/Select 2000 6027 94.54 809.13 579.80 via POE::Loop::Select	2535	POE/Any 2000 6648 94.79 774.40 575.51 via POE::Loop::Select
1982		2536
1983	=head3 Discussion	2537	=head3 Discussion
1984		2538
1985	The benchmark does I<not> measure scalability of the event loop very	2539	The benchmark does I<not> measure scalability of the event loop very
1986	well. For example, a select-based event loop (such as the pure perl one)	2540	well. For example, a select-based event loop (such as the pure perl one)
…		…
1998	benchmark machine, handling an event takes roughly 1600 CPU cycles with	2552	benchmark machine, handling an event takes roughly 1600 CPU cycles with
1999	EV, 3100 CPU cycles with AnyEvent's pure perl loop and almost 3000000 CPU	2553	EV, 3100 CPU cycles with AnyEvent's pure perl loop and almost 3000000 CPU
2000	cycles with POE.	2554	cycles with POE.
2001		2555
2002	C<EV> is the sole leader regarding speed and memory use, which are both	2556	C<EV> is the sole leader regarding speed and memory use, which are both
2003	maximal/minimal, respectively. Even when going through AnyEvent, it uses	2557	maximal/minimal, respectively. When using the L<AE> API there is zero
		2558	overhead (when going through the AnyEvent API create is about 5-6 times
		2559	slower, with other times being equal, so still uses far less memory than
2004	far less memory than any other event loop and is still faster than Event	2560	any other event loop and is still faster than Event natively).
2005	natively.
2006		2561
2007	The pure perl implementation is hit in a few sweet spots (both the	2562	The pure perl implementation is hit in a few sweet spots (both the
2008	constant timeout and the use of a single fd hit optimisations in the perl	2563	constant timeout and the use of a single fd hit optimisations in the perl
2009	interpreter and the backend itself). Nevertheless this shows that it	2564	interpreter and the backend itself). Nevertheless this shows that it
2010	adds very little overhead in itself. Like any select-based backend its	2565	adds very little overhead in itself. Like any select-based backend its
…		…
2058	(even when used without AnyEvent), but most event loops have acceptable	2613	(even when used without AnyEvent), but most event loops have acceptable
2059	performance with or without AnyEvent.	2614	performance with or without AnyEvent.
2060		2615
2061	=item * The overhead AnyEvent adds is usually much smaller than the overhead of	2616	=item * The overhead AnyEvent adds is usually much smaller than the overhead of
2062	the actual event loop, only with extremely fast event loops such as EV	2617	the actual event loop, only with extremely fast event loops such as EV
2063	adds AnyEvent significant overhead.	2618	does AnyEvent add significant overhead.
2064		2619
2065	=item * You should avoid POE like the plague if you want performance or	2620	=item * You should avoid POE like the plague if you want performance or
2066	reasonable memory usage.	2621	reasonable memory usage.
2067		2622
2068	=back	2623	=back
…		…
2084	In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100	2639	In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100
2085	(1%) are active. This mirrors the activity of large servers with many	2640	(1%) are active. This mirrors the activity of large servers with many
2086	connections, most of which are idle at any one point in time.	2641	connections, most of which are idle at any one point in time.
2087		2642
2088	Source code for this benchmark is found as F<eg/bench2> in the AnyEvent	2643	Source code for this benchmark is found as F<eg/bench2> in the AnyEvent
2089	distribution.	2644	distribution. It uses the L<AE> interface, which makes a real difference
		2645	for the EV and Perl backends only.
2090		2646
2091	=head3 Explanation of the columns	2647	=head3 Explanation of the columns
2092		2648
2093	I<sockets> is the number of sockets, and twice the number of "servers" (as	2649	I<sockets> is the number of sockets, and twice the number of "servers" (as
2094	each server has a read and write socket end).	2650	each server has a read and write socket end).
…		…
2102	a new one that moves the timeout into the future.	2658	a new one that moves the timeout into the future.
2103		2659
2104	=head3 Results	2660	=head3 Results
2105		2661
2106	name sockets create request	2662	name sockets create request
2107	EV 20000 69.01 11.16	2663	EV 20000 62.66 7.99
2108	Perl 20000 73.32 35.87	2664	Perl 20000 68.32 32.64
2109	IOAsync 20000 157.00 98.14 epoll	2665	IOAsync 20000 174.06 101.15 epoll
2110	IOAsync 20000 159.31 616.06 poll	2666	IOAsync 20000 174.67 610.84 poll
2111	Event 20000 212.62 257.32	2667	Event 20000 202.69 242.91
2112	Glib 20000 651.16 1896.30	2668	Glib 20000 557.01 1689.52
2113	POE 20000 349.67 12317.24 uses POE::Loop::Event	2669	POE 20000 341.54 12086.32 uses POE::Loop::Event
2114		2670
2115	=head3 Discussion	2671	=head3 Discussion
2116		2672
2117	This benchmark I<does> measure scalability and overall performance of the	2673	This benchmark I<does> measure scalability and overall performance of the
2118	particular event loop.	2674	particular event loop.
…		…
2244	As you can see, the AnyEvent + EV combination even beats the	2800	As you can see, the AnyEvent + EV combination even beats the
2245	hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl	2801	hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl
2246	backend easily beats IO::Lambda and POE.	2802	backend easily beats IO::Lambda and POE.
2247		2803
2248	And even the 100% non-blocking version written using the high-level (and	2804	And even the 100% non-blocking version written using the high-level (and
2249	slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda by a	2805	slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda
2250	large margin, even though it does all of DNS, tcp-connect and socket I/O	2806	higher level ("unoptimised") abstractions by a large margin, even though
2251	in a non-blocking way.	2807	it does all of DNS, tcp-connect and socket I/O in a non-blocking way.
2252		2808
2253	The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and	2809	The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and
2254	F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are	2810	F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are
2255	part of the IO::lambda distribution and were used without any changes.	2811	part of the IO::Lambda distribution and were used without any changes.
2256		2812
2257		2813
2258	=head1 SIGNALS	2814	=head1 SIGNALS
2259		2815
2260	AnyEvent currently installs handlers for these signals:	2816	AnyEvent currently installs handlers for these signals:
…		…
2297	unless defined $SIG{PIPE};	2853	unless defined $SIG{PIPE};
2298		2854
2299	=head1 RECOMMENDED/OPTIONAL MODULES	2855	=head1 RECOMMENDED/OPTIONAL MODULES
2300		2856
2301	One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and	2857	One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and
2302	it's built-in modules) are required to use it.	2858	its built-in modules) are required to use it.
2303		2859
2304	That does not mean that AnyEvent won't take advantage of some additional	2860	That does not mean that AnyEvent won't take advantage of some additional
2305	modules if they are installed.	2861	modules if they are installed.
2306		2862
2307	This section epxlains which additional modules will be used, and how they	2863	This section explains which additional modules will be used, and how they
2308	affect AnyEvent's operetion.	2864	affect AnyEvent's operation.
2309		2865
2310	=over 4	2866	=over 4
2311		2867
2312	=item L<Async::Interrupt>	2868	=item L<Async::Interrupt>
2313		2869
…		…
2318	catch the signals) with some delay (default is 10 seconds, look for	2874	catch the signals) with some delay (default is 10 seconds, look for
2319	C<$AnyEvent::MAX_SIGNAL_LATENCY>).	2875	C<$AnyEvent::MAX_SIGNAL_LATENCY>).
2320		2876
2321	If this module is available, then it will be used to implement signal	2877	If this module is available, then it will be used to implement signal
2322	catching, which means that signals will not be delayed, and the event loop	2878	catching, which means that signals will not be delayed, and the event loop
2323	will not be interrupted regularly, which is more efficient (And good for	2879	will not be interrupted regularly, which is more efficient (and good for
2324	battery life on laptops).	2880	battery life on laptops).
2325		2881
2326	This affects not just the pure-perl event loop, but also other event loops	2882	This affects not just the pure-perl event loop, but also other event loops
2327	that have no signal handling on their own (e.g. Glib, Tk, Qt).	2883	that have no signal handling on their own (e.g. Glib, Tk, Qt).
2328		2884
…		…
2340	automatic timer adjustments even when no monotonic clock is available,	2896	automatic timer adjustments even when no monotonic clock is available,
2341	can take avdantage of advanced kernel interfaces such as C<epoll> and	2897	can take avdantage of advanced kernel interfaces such as C<epoll> and
2342	C<kqueue>, and is the fastest backend I<by far>. You can even embed	2898	C<kqueue>, and is the fastest backend I<by far>. You can even embed
2343	L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>).	2899	L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>).
2344		2900
		2901	If you only use backends that rely on another event loop (e.g. C<Tk>),
		2902	then this module will do nothing for you.
		2903
2345	=item L<Guard>	2904	=item L<Guard>
2346		2905
2347	The guard module, when used, will be used to implement	2906	The guard module, when used, will be used to implement
2348	C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a	2907	C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a
2349	lot less memory), but otherwise doesn't affect guard operation much. It is	2908	lot less memory), but otherwise doesn't affect guard operation much. It is
2350	purely used for performance.	2909	purely used for performance.
2351		2910
2352	=item L<JSON> and L<JSON::XS>	2911	=item L<JSON> and L<JSON::XS>
2353		2912
2354	This module is required when you want to read or write JSON data via	2913	One of these modules is required when you want to read or write JSON data
2355	L<AnyEvent::Handle>. It is also written in pure-perl, but can take	2914	via L<AnyEvent::Handle>. L<JSON> is also written in pure-perl, but can take
2356	advantage of the ultra-high-speed L<JSON::XS> module when it is installed.	2915	advantage of the ultra-high-speed L<JSON::XS> module when it is installed.
2357
2358	In fact, L<AnyEvent::Handle> will use L<JSON::XS> by default if it is
2359	installed.
2360		2916
2361	=item L<Net::SSLeay>	2917	=item L<Net::SSLeay>
2362		2918
2363	Implementing TLS/SSL in Perl is certainly interesting, but not very	2919	Implementing TLS/SSL in Perl is certainly interesting, but not very
2364	worthwhile: If this module is installed, then L<AnyEvent::Handle> (with	2920	worthwhile: If this module is installed, then L<AnyEvent::Handle> (with
2365	the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL.	2921	the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL.
2366		2922
2367	=item L<Time::HiRes>	2923	=item L<Time::HiRes>
2368		2924
2369	This module is part of perl since release 5.008. It will be used when the	2925	This module is part of perl since release 5.008. It will be used when the
2370	chosen event library does not come with a timing source on it's own. The	2926	chosen event library does not come with a timing source of its own. The
2371	pure-perl event loop (L<AnyEvent::Impl::Perl>) will additionally use it to	2927	pure-perl event loop (L<AnyEvent::Loop>) will additionally load it to
2372	try to use a monotonic clock for timing stability.	2928	try to use a monotonic clock for timing stability.
2373		2929
2374	=back	2930	=back
2375		2931
2376		2932
2377	=head1 FORK	2933	=head1 FORK
2378		2934
2379	Most event libraries are not fork-safe. The ones who are usually are	2935	Most event libraries are not fork-safe. The ones who are usually are
2380	because they rely on inefficient but fork-safe C<select> or C<poll>	2936	because they rely on inefficient but fork-safe C<select> or C<poll> calls
2381	calls. Only L<EV> is fully fork-aware.	2937	- higher performance APIs such as BSD's kqueue or the dreaded Linux epoll
		2938	are usually badly thought-out hacks that are incompatible with fork in
		2939	one way or another. Only L<EV> is fully fork-aware and ensures that you
		2940	continue event-processing in both parent and child (or both, if you know
		2941	what you are doing).
		2942
		2943	This means that, in general, you cannot fork and do event processing in
		2944	the child if the event library was initialised before the fork (which
		2945	usually happens when the first AnyEvent watcher is created, or the library
		2946	is loaded).
2382		2947
2383	If you have to fork, you must either do so I<before> creating your first	2948	If you have to fork, you must either do so I<before> creating your first
2384	watcher OR you must not use AnyEvent at all in the child OR you must do	2949	watcher OR you must not use AnyEvent at all in the child OR you must do
2385	something completely out of the scope of AnyEvent.	2950	something completely out of the scope of AnyEvent.
		2951
		2952	The problem of doing event processing in the parent I<and> the child
		2953	is much more complicated: even for backends that I<are> fork-aware or
		2954	fork-safe, their behaviour is not usually what you want: fork clones all
		2955	watchers, that means all timers, I/O watchers etc. are active in both
		2956	parent and child, which is almost never what you want. USing C<exec>
		2957	to start worker children from some kind of manage rprocess is usually
		2958	preferred, because it is much easier and cleaner, at the expense of having
		2959	to have another binary.
2386		2960
2387		2961
2388	=head1 SECURITY CONSIDERATIONS	2962	=head1 SECURITY CONSIDERATIONS
2389		2963
2390	AnyEvent can be forced to load any event model via	2964	AnyEvent can be forced to load any event model via
…		…
2420	pronounced).	2994	pronounced).
2421		2995
2422		2996
2423	=head1 SEE ALSO	2997	=head1 SEE ALSO
2424		2998
2425	Utility functions: L<AnyEvent::Util>.	2999	Tutorial/Introduction: L<AnyEvent::Intro>.
2426		3000
2427	Event modules: L<EV>, L<EV::Glib>, L<Glib::EV>, L<Event>, L<Glib::Event>,	3001	FAQ: L<AnyEvent::FAQ>.
2428	L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.	3002
		3003	Utility functions: L<AnyEvent::Util> (misc. grab-bag), L<AnyEvent::Log>
		3004	(simply logging).
		3005
		3006	Development/Debugging: L<AnyEvent::Strict> (stricter checking),
		3007	L<AnyEvent::Debug> (interactive shell, watcher tracing).
		3008
		3009	Supported event modules: L<AnyEvent::Loop>, L<EV>, L<EV::Glib>,
		3010	L<Glib::EV>, L<Event>, L<Glib::Event>, L<Glib>, L<Tk>, L<Event::Lib>,
		3011	L<Qt>, L<POE>, L<FLTK>.
2429		3012
2430	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,	3013	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,
2431	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,	3014	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,
2432	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,	3015	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,
2433	L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>, L<Anyevent::Impl::Irssi>.	3016	L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>, L<Anyevent::Impl::Irssi>,
		3017	L<AnyEvent::Impl::FLTK>.
2434		3018
2435	Non-blocking file handles, sockets, TCP clients and	3019	Non-blocking handles, pipes, stream sockets, TCP clients and
2436	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.	3020	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.
2437		3021
		3022	Asynchronous File I/O: L<AnyEvent::IO>.
		3023
2438	Asynchronous DNS: L<AnyEvent::DNS>.	3024	Asynchronous DNS: L<AnyEvent::DNS>.
2439		3025
2440	Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>,	3026	Thread support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>.
2441	L<Coro::Event>,
2442		3027
2443	Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::XMPP>,	3028	Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::IRC>,
2444	L<AnyEvent::HTTP>.	3029	L<AnyEvent::HTTP>.
2445		3030
2446		3031
2447	=head1 AUTHOR	3032	=head1 AUTHOR
2448		3033
2449	Marc Lehmann <schmorp@schmorp.de>	3034	Marc Lehmann <schmorp@schmorp.de>
2450	http://home.schmorp.de/	3035	http://anyevent.schmorp.de
2451		3036
2452	=cut	3037	=cut
2453		3038
2454	1	3039	1
2455		3040

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