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Revision 1.266 by root, Thu Jul 30 03:41:56 2009 UTC vs.
Revision 1.410 by root, Fri Mar 1 06:03:21 2013 UTC

1	=head1 NAME	1	=head1 NAME
2		2
3	AnyEvent - the DBI of event loop programming	3	AnyEvent - the DBI of event loop programming
4		4
5	EV, Event, Glib, Tk, Perl, Event::Lib, Irssi, rxvt-unicode, IO::Async, Qt	5	EV, Event, Glib, Tk, Perl, Event::Lib, Irssi, rxvt-unicode, IO::Async, Qt,
6	and POE are various supported event loops/environments.	6	FLTK and POE are various supported event loops/environments.
7		7
8	=head1 SYNOPSIS	8	=head1 SYNOPSIS
9		9
10	use AnyEvent;	10	use AnyEvent;
11		11
		12	# if you prefer function calls, look at the AE manpage for
		13	# an alternative API.
		14
12	# file descriptor readable	15	# file handle or descriptor readable
13	my $w = AnyEvent->io (fh => $fh, poll => "r", cb => sub { ... });	16	my $w = AnyEvent->io (fh => $fh, poll => "r", cb => sub { ... });
14		17
15	# one-shot or repeating timers	18	# one-shot or repeating timers
16	my $w = AnyEvent->timer (after => $seconds, cb => sub { ... });	19	my $w = AnyEvent->timer (after => $seconds, cb => sub { ... });
17	my $w = AnyEvent->timer (after => $seconds, interval => $seconds, cb => ...	20	my $w = AnyEvent->timer (after => $seconds, interval => $seconds, cb => ...);
18		21
19	print AnyEvent->now; # prints current event loop time	22	print AnyEvent->now; # prints current event loop time
20	print AnyEvent->time; # think Time::HiRes::time or simply CORE::time.	23	print AnyEvent->time; # think Time::HiRes::time or simply CORE::time.
21		24
22	# POSIX signal	25	# POSIX signal
…		…
43	in a tutorial or some gentle introduction, have a look at the	46	in a tutorial or some gentle introduction, have a look at the
44	L<AnyEvent::Intro> manpage.	47	L<AnyEvent::Intro> manpage.
45		48
46	=head1 SUPPORT	49	=head1 SUPPORT
47		50
		51	An FAQ document is available as L<AnyEvent::FAQ>.
		52
48	There is a mailinglist for discussing all things AnyEvent, and an IRC	53	There also is a mailinglist for discussing all things AnyEvent, and an IRC
49	channel, too.	54	channel, too.
50		55
51	See the AnyEvent project page at the B<Schmorpforge Ta-Sa Software	56	See the AnyEvent project page at the B<Schmorpforge Ta-Sa Software
52	Repository>, at L<http://anyevent.schmorp.de>, for more info.	57	Repository>, at L<http://anyevent.schmorp.de>, for more info.
53		58
…		…
73	module users into the same thing by forcing them to use the same event	78	module users into the same thing by forcing them to use the same event
74	model you use.	79	model you use.
75		80
76	For modules like POE or IO::Async (which is a total misnomer as it is	81	For modules like POE or IO::Async (which is a total misnomer as it is
77	actually doing all I/O I<synchronously>...), using them in your module is	82	actually doing all I/O I<synchronously>...), using them in your module is
78	like joining a cult: After you joined, you are dependent on them and you	83	like joining a cult: After you join, you are dependent on them and you
79	cannot use anything else, as they are simply incompatible to everything	84	cannot use anything else, as they are simply incompatible to everything
80	that isn't them. What's worse, all the potential users of your	85	that isn't them. What's worse, all the potential users of your
81	module are I<also> forced to use the same event loop you use.	86	module are I<also> forced to use the same event loop you use.
82		87
83	AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works	88	AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works
84	fine. AnyEvent + Tk works fine etc. etc. but none of these work together	89	fine. AnyEvent + Tk works fine etc. etc. but none of these work together
85	with the rest: POE + IO::Async? No go. Tk + Event? No go. Again: if	90	with the rest: POE + EV? No go. Tk + Event? No go. Again: if your module
86	your module uses one of those, every user of your module has to use it,	91	uses one of those, every user of your module has to use it, too. But if
87	too. But if your module uses AnyEvent, it works transparently with all	92	your module uses AnyEvent, it works transparently with all event models it
88	event models it supports (including stuff like IO::Async, as long as those	93	supports (including stuff like IO::Async, as long as those use one of the
89	use one of the supported event loops. It is trivial to add new event loops	94	supported event loops. It is easy to add new event loops to AnyEvent, too,
90	to AnyEvent, too, so it is future-proof).	95	so it is future-proof).
91		96
92	In addition to being free of having to use I<the one and only true event	97	In addition to being free of having to use I<the one and only true event
93	model>, AnyEvent also is free of bloat and policy: with POE or similar	98	model>, AnyEvent also is free of bloat and policy: with POE or similar
94	modules, you get an enormous amount of code and strict rules you have to	99	modules, you get an enormous amount of code and strict rules you have to
95	follow. AnyEvent, on the other hand, is lean and up to the point, by only	100	follow. AnyEvent, on the other hand, is lean and to the point, by only
96	offering the functionality that is necessary, in as thin as a wrapper as	101	offering the functionality that is necessary, in as thin as a wrapper as
97	technically possible.	102	technically possible.
98		103
99	Of course, AnyEvent comes with a big (and fully optional!) toolbox	104	Of course, AnyEvent comes with a big (and fully optional!) toolbox
100	of useful functionality, such as an asynchronous DNS resolver, 100%	105	of useful functionality, such as an asynchronous DNS resolver, 100%
…		…
106	useful) and you want to force your users to use the one and only event	111	useful) and you want to force your users to use the one and only event
107	model, you should I<not> use this module.	112	model, you should I<not> use this module.
108		113
109	=head1 DESCRIPTION	114	=head1 DESCRIPTION
110		115
111	L<AnyEvent> provides an identical interface to multiple event loops. This	116	L<AnyEvent> provides a uniform interface to various event loops. This
112	allows module authors to utilise an event loop without forcing module	117	allows module authors to use event loop functionality without forcing
113	users to use the same event loop (as only a single event loop can coexist	118	module users to use a specific event loop implementation (since more
114	peacefully at any one time).	119	than one event loop cannot coexist peacefully).
115		120
116	The interface itself is vaguely similar, but not identical to the L<Event>	121	The interface itself is vaguely similar, but not identical to the L<Event>
117	module.	122	module.
118		123
119	During the first call of any watcher-creation method, the module tries	124	During the first call of any watcher-creation method, the module tries
120	to detect the currently loaded event loop by probing whether one of the	125	to detect the currently loaded event loop by probing whether one of the
121	following modules is already loaded: L<EV>,	126	following modules is already loaded: L<EV>, L<AnyEvent::Loop>,
122	L<Event>, L<Glib>, L<AnyEvent::Impl::Perl>, L<Tk>, L<Event::Lib>, L<Qt>,	127	L<Event>, L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>. The first one
123	L<POE>. The first one found is used. If none are found, the module tries	128	found is used. If none are detected, the module tries to load the first
124	to load these modules (excluding Tk, Event::Lib, Qt and POE as the pure perl	129	four modules in the order given; but note that if L<EV> is not
125	adaptor should always succeed) in the order given. The first one that can	130	available, the pure-perl L<AnyEvent::Loop> should always work, so
126	be successfully loaded will be used. If, after this, still none could be	131	the other two are not normally tried.
127	found, AnyEvent will fall back to a pure-perl event loop, which is not
128	very efficient, but should work everywhere.
129		132
130	Because AnyEvent first checks for modules that are already loaded, loading	133	Because AnyEvent first checks for modules that are already loaded, loading
131	an event model explicitly before first using AnyEvent will likely make	134	an event model explicitly before first using AnyEvent will likely make
132	that model the default. For example:	135	that model the default. For example:
133		136
…		…
135	use AnyEvent;	138	use AnyEvent;
136		139
137	# .. AnyEvent will likely default to Tk	140	# .. AnyEvent will likely default to Tk
138		141
139	The I<likely> means that, if any module loads another event model and	142	The I<likely> means that, if any module loads another event model and
140	starts using it, all bets are off. Maybe you should tell their authors to	143	starts using it, all bets are off - this case should be very rare though,
141	use AnyEvent so their modules work together with others seamlessly...	144	as very few modules hardcode event loops without announcing this very
		145	loudly.
142		146
143	The pure-perl implementation of AnyEvent is called	147	The pure-perl implementation of AnyEvent is called C<AnyEvent::Loop>. Like
144	C<AnyEvent::Impl::Perl>. Like other event modules you can load it	148	other event modules you can load it explicitly and enjoy the high
145	explicitly and enjoy the high availability of that event loop :)	149	availability of that event loop :)
146		150
147	=head1 WATCHERS	151	=head1 WATCHERS
148		152
149	AnyEvent has the central concept of a I<watcher>, which is an object that	153	AnyEvent has the central concept of a I<watcher>, which is an object that
150	stores relevant data for each kind of event you are waiting for, such as	154	stores relevant data for each kind of event you are waiting for, such as
…		…
155	callback when the event occurs (of course, only when the event model	159	callback when the event occurs (of course, only when the event model
156	is in control).	160	is in control).
157		161
158	Note that B<callbacks must not permanently change global variables>	162	Note that B<callbacks must not permanently change global variables>
159	potentially in use by the event loop (such as C<$_> or C<$[>) and that B<<	163	potentially in use by the event loop (such as C<$_> or C<$[>) and that B<<
160	callbacks must not C<die> >>. The former is good programming practise in	164	callbacks must not C<die> >>. The former is good programming practice in
161	Perl and the latter stems from the fact that exception handling differs	165	Perl and the latter stems from the fact that exception handling differs
162	widely between event loops.	166	widely between event loops.
163		167
164	To disable the watcher you have to destroy it (e.g. by setting the	168	To disable a watcher you have to destroy it (e.g. by setting the
165	variable you store it in to C<undef> or otherwise deleting all references	169	variable you store it in to C<undef> or otherwise deleting all references
166	to it).	170	to it).
167		171
168	All watchers are created by calling a method on the C<AnyEvent> class.	172	All watchers are created by calling a method on the C<AnyEvent> class.
169		173
170	Many watchers either are used with "recursion" (repeating timers for	174	Many watchers either are used with "recursion" (repeating timers for
171	example), or need to refer to their watcher object in other ways.	175	example), or need to refer to their watcher object in other ways.
172		176
173	An any way to achieve that is this pattern:	177	One way to achieve that is this pattern:
174		178
175	my $w; $w = AnyEvent->type (arg => value ..., cb => sub {	179	my $w; $w = AnyEvent->type (arg => value ..., cb => sub {
176	# you can use $w here, for example to undef it	180	# you can use $w here, for example to undef it
177	undef $w;	181	undef $w;
178	});	182	});
…		…
210		214
211	The I/O watcher might use the underlying file descriptor or a copy of it.	215	The I/O watcher might use the underlying file descriptor or a copy of it.
212	You must not close a file handle as long as any watcher is active on the	216	You must not close a file handle as long as any watcher is active on the
213	underlying file descriptor.	217	underlying file descriptor.
214		218
215	Some event loops issue spurious readyness notifications, so you should	219	Some event loops issue spurious readiness notifications, so you should
216	always use non-blocking calls when reading/writing from/to your file	220	always use non-blocking calls when reading/writing from/to your file
217	handles.	221	handles.
218		222
219	Example: wait for readability of STDIN, then read a line and disable the	223	Example: wait for readability of STDIN, then read a line and disable the
220	watcher.	224	watcher.
…		…
244		248
245	Although the callback might get passed parameters, their value and	249	Although the callback might get passed parameters, their value and
246	presence is undefined and you cannot rely on them. Portable AnyEvent	250	presence is undefined and you cannot rely on them. Portable AnyEvent
247	callbacks cannot use arguments passed to time watcher callbacks.	251	callbacks cannot use arguments passed to time watcher callbacks.
248		252
249	The callback will normally be invoked once only. If you specify another	253	The callback will normally be invoked only once. If you specify another
250	parameter, C<interval>, as a strictly positive number (> 0), then the	254	parameter, C<interval>, as a strictly positive number (> 0), then the
251	callback will be invoked regularly at that interval (in fractional	255	callback will be invoked regularly at that interval (in fractional
252	seconds) after the first invocation. If C<interval> is specified with a	256	seconds) after the first invocation. If C<interval> is specified with a
253	false value, then it is treated as if it were missing.	257	false value, then it is treated as if it were not specified at all.
254		258
255	The callback will be rescheduled before invoking the callback, but no	259	The callback will be rescheduled before invoking the callback, but no
256	attempt is done to avoid timer drift in most backends, so the interval is	260	attempt is made to avoid timer drift in most backends, so the interval is
257	only approximate.	261	only approximate.
258		262
259	Example: fire an event after 7.7 seconds.	263	Example: fire an event after 7.7 seconds.
260		264
261	my $w = AnyEvent->timer (after => 7.7, cb => sub {	265	my $w = AnyEvent->timer (after => 7.7, cb => sub {
…		…
279		283
280	While most event loops expect timers to specified in a relative way, they	284	While most event loops expect timers to specified in a relative way, they
281	use absolute time internally. This makes a difference when your clock	285	use absolute time internally. This makes a difference when your clock
282	"jumps", for example, when ntp decides to set your clock backwards from	286	"jumps", for example, when ntp decides to set your clock backwards from
283	the wrong date of 2014-01-01 to 2008-01-01, a watcher that is supposed to	287	the wrong date of 2014-01-01 to 2008-01-01, a watcher that is supposed to
284	fire "after" a second might actually take six years to finally fire.	288	fire "after a second" might actually take six years to finally fire.
285		289
286	AnyEvent cannot compensate for this. The only event loop that is conscious	290	AnyEvent cannot compensate for this. The only event loop that is conscious
287	about these issues is L<EV>, which offers both relative (ev_timer, based	291	of these issues is L<EV>, which offers both relative (ev_timer, based
288	on true relative time) and absolute (ev_periodic, based on wallclock time)	292	on true relative time) and absolute (ev_periodic, based on wallclock time)
289	timers.	293	timers.
290		294
291	AnyEvent always prefers relative timers, if available, matching the	295	AnyEvent always prefers relative timers, if available, matching the
292	AnyEvent API.	296	AnyEvent API.
…		…
314	I<In almost all cases (in all cases if you don't care), this is the	318	I<In almost all cases (in all cases if you don't care), this is the
315	function to call when you want to know the current time.>	319	function to call when you want to know the current time.>
316		320
317	This function is also often faster then C<< AnyEvent->time >>, and	321	This function is also often faster then C<< AnyEvent->time >>, and
318	thus the preferred method if you want some timestamp (for example,	322	thus the preferred method if you want some timestamp (for example,
319	L<AnyEvent::Handle> uses this to update it's activity timeouts).	323	L<AnyEvent::Handle> uses this to update its activity timeouts).
320		324
321	The rest of this section is only of relevance if you try to be very exact	325	The rest of this section is only of relevance if you try to be very exact
322	with your timing, you can skip it without bad conscience.	326	with your timing; you can skip it without a bad conscience.
323		327
324	For a practical example of when these times differ, consider L<Event::Lib>	328	For a practical example of when these times differ, consider L<Event::Lib>
325	and L<EV> and the following set-up:	329	and L<EV> and the following set-up:
326		330
327	The event loop is running and has just invoked one of your callback at	331	The event loop is running and has just invoked one of your callbacks at
328	time=500 (assume no other callbacks delay processing). In your callback,	332	time=500 (assume no other callbacks delay processing). In your callback,
329	you wait a second by executing C<sleep 1> (blocking the process for a	333	you wait a second by executing C<sleep 1> (blocking the process for a
330	second) and then (at time=501) you create a relative timer that fires	334	second) and then (at time=501) you create a relative timer that fires
331	after three seconds.	335	after three seconds.
332		336
…		…
352	difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into	356	difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into
353	account.	357	account.
354		358
355	=item AnyEvent->now_update	359	=item AnyEvent->now_update
356		360
357	Some event loops (such as L<EV> or L<AnyEvent::Impl::Perl>) cache	361	Some event loops (such as L<EV> or L<AnyEvent::Loop>) cache the current
358	the current time for each loop iteration (see the discussion of L<<	362	time for each loop iteration (see the discussion of L<< AnyEvent->now >>,
359	AnyEvent->now >>, above).	363	above).
360		364
361	When a callback runs for a long time (or when the process sleeps), then	365	When a callback runs for a long time (or when the process sleeps), then
362	this "current" time will differ substantially from the real time, which	366	this "current" time will differ substantially from the real time, which
363	might affect timers and time-outs.	367	might affect timers and time-outs.
364		368
365	When this is the case, you can call this method, which will update the	369	When this is the case, you can call this method, which will update the
366	event loop's idea of "current time".	370	event loop's idea of "current time".
		371
		372	A typical example would be a script in a web server (e.g. C<mod_perl>) -
		373	when mod_perl executes the script, then the event loop will have the wrong
		374	idea about the "current time" (being potentially far in the past, when the
		375	script ran the last time). In that case you should arrange a call to C<<
		376	AnyEvent->now_update >> each time the web server process wakes up again
		377	(e.g. at the start of your script, or in a handler).
367		378
368	Note that updating the time I<might> cause some events to be handled.	379	Note that updating the time I<might> cause some events to be handled.
369		380
370	=back	381	=back
371		382
…		…
396		407
397	Example: exit on SIGINT	408	Example: exit on SIGINT
398		409
399	my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });	410	my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });
400		411
		412	=head3 Restart Behaviour
		413
		414	While restart behaviour is up to the event loop implementation, most will
		415	not restart syscalls (that includes L<Async::Interrupt> and AnyEvent's
		416	pure perl implementation).
		417
		418	=head3 Safe/Unsafe Signals
		419
		420	Perl signals can be either "safe" (synchronous to opcode handling)
		421	or "unsafe" (asynchronous) - the former might delay signal delivery
		422	indefinitely, the latter might corrupt your memory.
		423
		424	AnyEvent signal handlers are, in addition, synchronous to the event loop,
		425	i.e. they will not interrupt your running perl program but will only be
		426	called as part of the normal event handling (just like timer, I/O etc.
		427	callbacks, too).
		428
401	=head3 Signal Races, Delays and Workarounds	429	=head3 Signal Races, Delays and Workarounds
402		430
403	Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support attaching	431	Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support
404	callbacks to signals in a generic way, which is a pity, as you cannot do	432	attaching callbacks to signals in a generic way, which is a pity,
405	race-free signal handling in perl. AnyEvent will try to do it's best, but	433	as you cannot do race-free signal handling in perl, requiring
		434	C libraries for this. AnyEvent will try to do its best, which
406	in some cases, signals will be delayed. The maximum time a signal might	435	means in some cases, signals will be delayed. The maximum time
407	be delayed is specified in C<$AnyEvent::MAX_SIGNAL_LATENCY> (default: 10	436	a signal might be delayed is 10 seconds by default, but can
408	seconds). This variable can be changed only before the first signal	437	be overriden via C<$ENV{PERL_ANYEVENT_MAX_SIGNAL_LATENCY}> or
409	watcher is created, and should be left alone otherwise. Higher values	438	C<$AnyEvent::MAX_SIGNAL_LATENCY> - see the L<ENVIRONMENT VARIABLES>
410	will cause fewer spurious wake-ups, which is better for power and CPU	439	section for details.
		440
411	saving. All these problems can be avoided by installing the optional	441	All these problems can be avoided by installing the optional
412	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
413	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>
414	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
415	those, you just have to suffer the delays.	445	delays.
416		446
417	=head2 CHILD PROCESS WATCHERS	447	=head2 CHILD PROCESS WATCHERS
418		448
419	$w = AnyEvent->child (pid => <process id>, cb => <callback>);	449	$w = AnyEvent->child (pid => <process id>, cb => <callback>);
420		450
421	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.
422		452
423	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,
424	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
425	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
426	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
427	(stopped/continued).	457	(stopped/continued).
428		458
…		…
450	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
451	watcher before you C<fork> the child (alternatively, you can call	481	watcher before you C<fork> the child (alternatively, you can call
452	C<AnyEvent::detect>).	482	C<AnyEvent::detect>).
453		483
454	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
455	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
456	mentioned in the description of signal watchers apply.	486	problems mentioned in the description of signal watchers apply.
457		487
458	Example: fork a process and wait for it	488	Example: fork a process and wait for it
459		489
460	my $done = AnyEvent->condvar;	490	my $done = AnyEvent->condvar;
461		491
…		…
475		505
476	=head2 IDLE WATCHERS	506	=head2 IDLE WATCHERS
477		507
478	$w = AnyEvent->idle (cb => <callback>);	508	$w = AnyEvent->idle (cb => <callback>);
479		509
480	Sometimes there is a need to do something, but it is not so important	510	This will repeatedly invoke the callback after the process becomes idle,
481	to do it instantly, but only when there is nothing better to do. This	511	until either the watcher is destroyed or new events have been detected.
482	"nothing better to do" is usually defined to be "no other events need
483	attention by the event loop".
484		512
485	Idle watchers ideally get invoked when the event loop has nothing	513	Idle watchers are useful when there is a need to do something, but it
486	better to do, just before it would block the process to wait for new	514	is not so important (or wise) to do it instantly. The callback will be
487	events. Instead of blocking, the idle watcher is invoked.	515	invoked only when there is "nothing better to do", which is usually
		516	defined as "all outstanding events have been handled and no new events
		517	have been detected". That means that idle watchers ideally get invoked
		518	when the event loop has just polled for new events but none have been
		519	detected. Instead of blocking to wait for more events, the idle watchers
		520	will be invoked.
488		521
489	Most event loops unfortunately do not really support idle watchers (only	522	Unfortunately, most event loops do not really support idle watchers (only
490	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
491	will simply call the callback "from time to time".	524	will simply call the callback "from time to time".
492		525
493	Example: read lines from STDIN, but only process them when the	526	Example: read lines from STDIN, but only process them when the
494	program is otherwise idle:	527	program is otherwise idle:
…		…
522	will actively watch for new events and call your callbacks.	555	will actively watch for new events and call your callbacks.
523		556
524	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
525	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).
526		559
527	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
528	because they represent a condition that must become true.	561	they represent a condition that must become true.
529		562
530	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.
531		564
532	Condition variables can be created by calling the C<< AnyEvent->condvar	565	Condition variables can be created by calling the C<< AnyEvent->condvar
533	>> method, usually without arguments. The only argument pair allowed is	566	>> method, usually without arguments. The only argument pair allowed is
…		…
538	After creation, the condition variable is "false" until it becomes "true"	571	After creation, the condition variable is "false" until it becomes "true"
539	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
540	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<<
541	->send >> method).	574	->send >> method).
542		575
543	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
544	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:
545	in time where multiple outstanding events have been processed. And yet	578
546	another way to call them is transactions - each condition variable can be	579	=over 4
547	used to represent a transaction, which finishes at some point and delivers	580
548	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
549	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
550		599
551	Condition variables are very useful to signal that something has finished,	600	Condition variables are very useful to signal that something has finished,
552	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,
553	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
554	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
…		…
567		616
568	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
569	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
570	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
571	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
572	it's C<new> method in your own C<new> method.	621	its C<new> method in your own C<new> method.
573		622
574	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
575	eventually calls C<< -> send >>, and the "consumer side", which waits	624	eventually calls C<< -> send >>, and the "consumer side", which waits
576	for the send to occur.	625	for the send to occur.
577		626
578	Example: wait for a timer.	627	Example: wait for a timer.
579		628
580	# wait till the result is ready	629	# condition: "wait till the timer is fired"
581	my $result_ready = AnyEvent->condvar;	630	my $timer_fired = AnyEvent->condvar;
582		631
583	# do something such as adding a timer	632	# create the timer - we could wait for, say
584	# or socket watcher the calls $result_ready->send	633	# a handle becomign ready, or even an
585	# when the "result" is ready.	634	# AnyEvent::HTTP request to finish, but
586	# in this case, we simply use a timer:	635	# in this case, we simply use a timer:
587	my $w = AnyEvent->timer (	636	my $w = AnyEvent->timer (
588	after => 1,	637	after => 1,
589	cb => sub { $result_ready->send },	638	cb => sub { $timer_fired->send },
590	);	639	);
591		640
592	# this "blocks" (while handling events) till the callback	641	# this "blocks" (while handling events) till the callback
593	# calls -<send	642	# calls ->send
594	$result_ready->recv;	643	$timer_fired->recv;
595		644
596	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
597	variables are also callable directly.	646	variables are also callable directly.
598		647
599	my $done = AnyEvent->condvar;	648	my $done = AnyEvent->condvar;
…		…
642	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
643	C<send>.	692	C<send>.
644		693
645	=item $cv->croak ($error)	694	=item $cv->croak ($error)
646		695
647	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
648	C<Carp::croak> with the given error message/object/scalar.	697	C<Carp::croak> with the given error message/object/scalar.
649		698
650	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
651	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
652	delays the error detetcion, but has the overwhelmign advantage that it	701	delays the error detection, but has the overwhelming advantage that it
653	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
654	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
655	the problem.	704	the problem.
656		705
657	=item $cv->begin ([group callback])	706	=item $cv->begin ([group callback])
658		707
659	=item $cv->end	708	=item $cv->end
…		…
662	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
663	to use a condition variable for the whole process.	712	to use a condition variable for the whole process.
664		713
665	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
666	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
667	>>, 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
668	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
669	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.
670		720
671	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
672	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
673	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).
674		724
…		…
696	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
697	sending.	747	sending.
698		748
699	The ping example mentioned above is slightly more complicated, as the	749	The ping example mentioned above is slightly more complicated, as the
700	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
701	begung can potentially be zero:	751	begun can potentially be zero:
702		752
703	my $cv = AnyEvent->condvar;	753	my $cv = AnyEvent->condvar;
704		754
705	my %result;	755	my %result;
706	$cv->begin (sub { $cv->send (\%result) });	756	$cv->begin (sub { shift->send (\%result) });
707		757
708	for my $host (@list_of_hosts) {	758	for my $host (@list_of_hosts) {
709	$cv->begin;	759	$cv->begin;
710	ping_host_then_call_callback $host, sub {	760	ping_host_then_call_callback $host, sub {
711	$result{$host} = ...;	761	$result{$host} = ...;
…		…
713	};	763	};
714	}	764	}
715		765
716	$cv->end;	766	$cv->end;
717		767
		768	...
		769
		770	my $results = $cv->recv;
		771
718	This code fragment supposedly pings a number of hosts and calls	772	This code fragment supposedly pings a number of hosts and calls
719	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
720	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
721	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
722	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
…		…
727	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
728	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
729	doesn't execute once).	783	doesn't execute once).
730		784
731	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
732	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
733	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
734	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,
735	call C<end>.	789	call C<end>.
736		790
737	=back	791	=back
…		…
744	=over 4	798	=over 4
745		799
746	=item $cv->recv	800	=item $cv->recv
747		801
748	Wait (blocking if necessary) until the C<< ->send >> or C<< ->croak	802	Wait (blocking if necessary) until the C<< ->send >> or C<< ->croak
749	>> methods have been called on c<$cv>, while servicing other watchers	803	>> methods have been called on C<$cv>, while servicing other watchers
750	normally.	804	normally.
751		805
752	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
753	will return immediately.	807	will return immediately.
754		808
…		…
757		811
758	In list context, all parameters passed to C<send> will be returned,	812	In list context, all parameters passed to C<send> will be returned,
759	in scalar context only the first one will be returned.	813	in scalar context only the first one will be returned.
760		814
761	Note that doing a blocking wait in a callback is not supported by any	815	Note that doing a blocking wait in a callback is not supported by any
762	event loop, that is, recursive invocation of a blocking C<< ->recv	816	event loop, that is, recursive invocation of a blocking C<< ->recv >> is
763	>> is not allowed, and the C<recv> call will C<croak> if such a	817	not allowed and the C<recv> call will C<croak> if such a condition is
764	condition is detected. This condition can be slightly loosened by using	818	detected. This requirement can be dropped by relying on L<Coro::AnyEvent>
765	L<Coro::AnyEvent>, which allows you to do a blocking C<< ->recv >> from	819	, which allows you to do a blocking C<< ->recv >> from any thread
766	any thread that doesn't run the event loop itself.	820	that doesn't run the event loop itself. L<Coro::AnyEvent> is loaded
		821	automatically when L<Coro> is used with L<AnyEvent>, so code does not need
		822	to do anything special to take advantage of that: any code that would
		823	normally block your program because it calls C<recv>, be executed in an
		824	C<async> thread instead without blocking other threads.
767		825
768	Not all event models support a blocking wait - some die in that case	826	Not all event models support a blocking wait - some die in that case
769	(programs might want to do that to stay interactive), so I<if you are	827	(programs might want to do that to stay interactive), so I<if you are
770	using this from a module, never require a blocking wait>. Instead, let the	828	using this from a module, never require a blocking wait>. Instead, let the
771	caller decide whether the call will block or not (for example, by coupling	829	caller decide whether the call will block or not (for example, by coupling
772	condition variables with some kind of request results and supporting	830	condition variables with some kind of request results and supporting
773	callbacks so the caller knows that getting the result will not block,	831	callbacks so the caller knows that getting the result will not block,
774	while still supporting blocking waits if the caller so desires).	832	while still supporting blocking waits if the caller so desires).
775		833
776	You can ensure that C<< -recv >> never blocks by setting a callback and	834	You can ensure that C<< ->recv >> never blocks by setting a callback and
777	only calling C<< ->recv >> from within that callback (or at a later	835	only calling C<< ->recv >> from within that callback (or at a later
778	time). This will work even when the event loop does not support blocking	836	time). This will work even when the event loop does not support blocking
779	waits otherwise.	837	waits otherwise.
780		838
781	=item $bool = $cv->ready	839	=item $bool = $cv->ready
…		…
787		845
788	This is a mutator function that returns the callback set and optionally	846	This is a mutator function that returns the callback set and optionally
789	replaces it before doing so.	847	replaces it before doing so.
790		848
791	The callback will be called when the condition becomes "true", i.e. when	849	The callback will be called when the condition becomes "true", i.e. when
792	C<send> or C<croak> are called, with the only argument being the condition	850	C<send> or C<croak> are called, with the only argument being the
793	variable itself. Calling C<recv> inside the callback or at any later time	851	condition variable itself. If the condition is already true, the
794	is guaranteed not to block.	852	callback is called immediately when it is set. Calling C<recv> inside
		853	the callback or at any later time is guaranteed not to block.
795		854
796	=back	855	=back
797		856
798	=head1 SUPPORTED EVENT LOOPS/BACKENDS	857	=head1 SUPPORTED EVENT LOOPS/BACKENDS
799		858
…		…
802	=over 4	861	=over 4
803		862
804	=item Backends that are autoprobed when no other event loop can be found.	863	=item Backends that are autoprobed when no other event loop can be found.
805		864
806	EV is the preferred backend when no other event loop seems to be in	865	EV is the preferred backend when no other event loop seems to be in
807	use. If EV is not installed, then AnyEvent will try Event, and, failing	866	use. If EV is not installed, then AnyEvent will fall back to its own
808	that, will fall back to its own pure-perl implementation, which is	867	pure-perl implementation, which is available everywhere as it comes with
809	available everywhere as it comes with AnyEvent itself.	868	AnyEvent itself.
810		869
811	AnyEvent::Impl::EV based on EV (interface to libev, best choice).	870	AnyEvent::Impl::EV based on EV (interface to libev, best choice).
812	AnyEvent::Impl::Event based on Event, very stable, few glitches.
813	AnyEvent::Impl::Perl pure-perl implementation, fast and portable.	871	AnyEvent::Impl::Perl pure-perl AnyEvent::Loop, fast and portable.
814		872
815	=item Backends that are transparently being picked up when they are used.	873	=item Backends that are transparently being picked up when they are used.
816		874
817	These will be used when they are currently loaded when the first watcher	875	These will be used if they are already loaded when the first watcher
818	is created, in which case it is assumed that the application is using	876	is created, in which case it is assumed that the application is using
819	them. This means that AnyEvent will automatically pick the right backend	877	them. This means that AnyEvent will automatically pick the right backend
820	when the main program loads an event module before anything starts to	878	when the main program loads an event module before anything starts to
821	create watchers. Nothing special needs to be done by the main program.	879	create watchers. Nothing special needs to be done by the main program.
822		880
		881	AnyEvent::Impl::Event based on Event, very stable, few glitches.
823	AnyEvent::Impl::Glib based on Glib, slow but very stable.	882	AnyEvent::Impl::Glib based on Glib, slow but very stable.
824	AnyEvent::Impl::Tk based on Tk, very broken.	883	AnyEvent::Impl::Tk based on Tk, very broken.
825	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.	884	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
826	AnyEvent::Impl::POE based on POE, very slow, some limitations.	885	AnyEvent::Impl::POE based on POE, very slow, some limitations.
827	AnyEvent::Impl::Irssi used when running within irssi.	886	AnyEvent::Impl::Irssi used when running within irssi.
		887	AnyEvent::Impl::IOAsync based on IO::Async.
		888	AnyEvent::Impl::Cocoa based on Cocoa::EventLoop.
		889	AnyEvent::Impl::FLTK based on FLTK (fltk 2 binding).
828		890
829	=item Backends with special needs.	891	=item Backends with special needs.
830		892
831	Qt requires the Qt::Application to be instantiated first, but will	893	Qt requires the Qt::Application to be instantiated first, but will
832	otherwise be picked up automatically. As long as the main program	894	otherwise be picked up automatically. As long as the main program
833	instantiates the application before any AnyEvent watchers are created,	895	instantiates the application before any AnyEvent watchers are created,
834	everything should just work.	896	everything should just work.
835		897
836	AnyEvent::Impl::Qt based on Qt.	898	AnyEvent::Impl::Qt based on Qt.
837		899
838	Support for IO::Async can only be partial, as it is too broken and
839	architecturally limited to even support the AnyEvent API. It also
840	is the only event loop that needs the loop to be set explicitly, so
841	it can only be used by a main program knowing about AnyEvent. See
842	L<AnyEvent::Impl::Async> for the gory details.
843
844	AnyEvent::Impl::IOAsync based on IO::Async, cannot be autoprobed.
845
846	=item Event loops that are indirectly supported via other backends.	900	=item Event loops that are indirectly supported via other backends.
847		901
848	Some event loops can be supported via other modules:	902	Some event loops can be supported via other modules:
849		903
850	There is no direct support for WxWidgets (L<Wx>) or L<Prima>.	904	There is no direct support for WxWidgets (L<Wx>) or L<Prima>.
…		…
875	Contains C<undef> until the first watcher is being created, before the	929	Contains C<undef> until the first watcher is being created, before the
876	backend has been autodetected.	930	backend has been autodetected.
877		931
878	Afterwards it contains the event model that is being used, which is the	932	Afterwards it contains the event model that is being used, which is the
879	name of the Perl class implementing the model. This class is usually one	933	name of the Perl class implementing the model. This class is usually one
880	of the C<AnyEvent::Impl:xxx> modules, but can be any other class in the	934	of the C<AnyEvent::Impl::xxx> modules, but can be any other class in the
881	case AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode> it	935	case AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode> it
882	will be C<urxvt::anyevent>).	936	will be C<urxvt::anyevent>).
883		937
884	=item AnyEvent::detect	938	=item AnyEvent::detect
885		939
886	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model	940	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model
887	if necessary. You should only call this function right before you would	941	if necessary. You should only call this function right before you would
888	have created an AnyEvent watcher anyway, that is, as late as possible at	942	have created an AnyEvent watcher anyway, that is, as late as possible at
889	runtime, and not e.g. while initialising of your module.	943	runtime, and not e.g. during initialisation of your module.
		944
		945	The effect of calling this function is as if a watcher had been created
		946	(specifically, actions that happen "when the first watcher is created"
		947	happen when calling detetc as well).
890		948
891	If you need to do some initialisation before AnyEvent watchers are	949	If you need to do some initialisation before AnyEvent watchers are
892	created, use C<post_detect>.	950	created, use C<post_detect>.
893		951
894	=item $guard = AnyEvent::post_detect { BLOCK }	952	=item $guard = AnyEvent::post_detect { BLOCK }
895		953
896	Arranges for the code block to be executed as soon as the event model is	954	Arranges for the code block to be executed as soon as the event model is
897	autodetected (or immediately if this has already happened).	955	autodetected (or immediately if that has already happened).
898		956
899	The block will be executed I<after> the actual backend has been detected	957	The block will be executed I<after> the actual backend has been detected
900	(C<$AnyEvent::MODEL> is set), but I<before> any watchers have been	958	(C<$AnyEvent::MODEL> is set), but I<before> any watchers have been
901	created, so it is possible to e.g. patch C<@AnyEvent::ISA> or do	959	created, so it is possible to e.g. patch C<@AnyEvent::ISA> or do
902	other initialisations - see the sources of L<AnyEvent::Strict> or	960	other initialisations - see the sources of L<AnyEvent::Strict> or
…		…
911	that automatically removes the callback again when it is destroyed (or	969	that automatically removes the callback again when it is destroyed (or
912	C<undef> when the hook was immediately executed). See L<AnyEvent::AIO> for	970	C<undef> when the hook was immediately executed). See L<AnyEvent::AIO> for
913	a case where this is useful.	971	a case where this is useful.
914		972
915	Example: Create a watcher for the IO::AIO module and store it in	973	Example: Create a watcher for the IO::AIO module and store it in
916	C<$WATCHER>. Only do so after the event loop is initialised, though.	974	C<$WATCHER>, but do so only do so after the event loop is initialised.
917		975
918	our WATCHER;	976	our WATCHER;
919		977
920	my $guard = AnyEvent::post_detect {	978	my $guard = AnyEvent::post_detect {
921	$WATCHER = AnyEvent->io (fh => IO::AIO::poll_fileno, poll => 'r', cb => \&IO::AIO::poll_cb);	979	$WATCHER = AnyEvent->io (fh => IO::AIO::poll_fileno, poll => 'r', cb => \&IO::AIO::poll_cb);
…		…
929	$WATCHER ||= $guard;	987	$WATCHER ||= $guard;
930		988
931	=item @AnyEvent::post_detect	989	=item @AnyEvent::post_detect
932		990
933	If there are any code references in this array (you can C<push> to it	991	If there are any code references in this array (you can C<push> to it
934	before or after loading AnyEvent), then they will called directly after	992	before or after loading AnyEvent), then they will be called directly
935	the event loop has been chosen.	993	after the event loop has been chosen.
936		994
937	You should check C<$AnyEvent::MODEL> before adding to this array, though:	995	You should check C<$AnyEvent::MODEL> before adding to this array, though:
938	if it is defined then the event loop has already been detected, and the	996	if it is defined then the event loop has already been detected, and the
939	array will be ignored.	997	array will be ignored.
940		998
941	Best use C<AnyEvent::post_detect { BLOCK }> when your application allows	999	Best use C<AnyEvent::post_detect { BLOCK }> when your application allows
942	it,as it takes care of these details.	1000	it, as it takes care of these details.
943		1001
944	This variable is mainly useful for modules that can do something useful	1002	This variable is mainly useful for modules that can do something useful
945	when AnyEvent is used and thus want to know when it is initialised, but do	1003	when AnyEvent is used and thus want to know when it is initialised, but do
946	not need to even load it by default. This array provides the means to hook	1004	not need to even load it by default. This array provides the means to hook
947	into AnyEvent passively, without loading it.	1005	into AnyEvent passively, without loading it.
948		1006
		1007	Example: To load Coro::AnyEvent whenever Coro and AnyEvent are used
		1008	together, you could put this into Coro (this is the actual code used by
		1009	Coro to accomplish this):
		1010
		1011	if (defined $AnyEvent::MODEL) {
		1012	# AnyEvent already initialised, so load Coro::AnyEvent
		1013	require Coro::AnyEvent;
		1014	} else {
		1015	# AnyEvent not yet initialised, so make sure to load Coro::AnyEvent
		1016	# as soon as it is
		1017	push @AnyEvent::post_detect, sub { require Coro::AnyEvent };
		1018	}
		1019
		1020	=item AnyEvent::postpone { BLOCK }
		1021
		1022	Arranges for the block to be executed as soon as possible, but not before
		1023	the call itself returns. In practise, the block will be executed just
		1024	before the event loop polls for new events, or shortly afterwards.
		1025
		1026	This function never returns anything (to make the C<return postpone { ...
		1027	}> idiom more useful.
		1028
		1029	To understand the usefulness of this function, consider a function that
		1030	asynchronously does something for you and returns some transaction
		1031	object or guard to let you cancel the operation. For example,
		1032	C<AnyEvent::Socket::tcp_connect>:
		1033
		1034	# start a conenction attempt unless one is active
		1035	$self->{connect_guard} ||= AnyEvent::Socket::tcp_connect "www.example.net", 80, sub {
		1036	delete $self->{connect_guard};
		1037	...
		1038	};
		1039
		1040	Imagine that this function could instantly call the callback, for
		1041	example, because it detects an obvious error such as a negative port
		1042	number. Invoking the callback before the function returns causes problems
		1043	however: the callback will be called and will try to delete the guard
		1044	object. But since the function hasn't returned yet, there is nothing to
		1045	delete. When the function eventually returns it will assign the guard
		1046	object to C<< $self->{connect_guard} >>, where it will likely never be
		1047	deleted, so the program thinks it is still trying to connect.
		1048
		1049	This is where C<AnyEvent::postpone> should be used. Instead of calling the
		1050	callback directly on error:
		1051
		1052	$cb->(undef), return # signal error to callback, BAD!
		1053	if $some_error_condition;
		1054
		1055	It should use C<postpone>:
		1056
		1057	AnyEvent::postpone { $cb->(undef) }, return # signal error to callback, later
		1058	if $some_error_condition;
		1059
		1060	=item AnyEvent::log $level, $msg[, @args]
		1061
		1062	Log the given C<$msg> at the given C<$level>.
		1063
		1064	If L<AnyEvent::Log> is not loaded then this function makes a simple test
		1065	to see whether the message will be logged. If the test succeeds it will
		1066	load AnyEvent::Log and call C<AnyEvent::Log::log> - consequently, look at
		1067	the L<AnyEvent::Log> documentation for details.
		1068
		1069	If the test fails it will simply return. Right now this happens when a
		1070	numerical loglevel is used and it is larger than the level specified via
		1071	C<$ENV{PERL_ANYEVENT_VERBOSE}>.
		1072
		1073	If you want to sprinkle loads of logging calls around your code, consider
		1074	creating a logger callback with the C<AnyEvent::Log::logger> function,
		1075	which can reduce typing, codesize and can reduce the logging overhead
		1076	enourmously.
		1077
949	=back	1078	=back
950		1079
951	=head1 WHAT TO DO IN A MODULE	1080	=head1 WHAT TO DO IN A MODULE
952		1081
953	As a module author, you should C<use AnyEvent> and call AnyEvent methods	1082	As a module author, you should C<use AnyEvent> and call AnyEvent methods
…		…
963	because it will stall the whole program, and the whole point of using	1092	because it will stall the whole program, and the whole point of using
964	events is to stay interactive.	1093	events is to stay interactive.
965		1094
966	It is fine, however, to call C<< ->recv >> when the user of your module	1095	It is fine, however, to call C<< ->recv >> when the user of your module
967	requests it (i.e. if you create a http request object ad have a method	1096	requests it (i.e. if you create a http request object ad have a method
968	called C<results> that returns the results, it should call C<< ->recv >>	1097	called C<results> that returns the results, it may call C<< ->recv >>
969	freely, as the user of your module knows what she is doing. always).	1098	freely, as the user of your module knows what she is doing. Always).
970		1099
971	=head1 WHAT TO DO IN THE MAIN PROGRAM	1100	=head1 WHAT TO DO IN THE MAIN PROGRAM
972		1101
973	There will always be a single main program - the only place that should	1102	There will always be a single main program - the only place that should
974	dictate which event model to use.	1103	dictate which event model to use.
975		1104
976	If it doesn't care, it can just "use AnyEvent" and use it itself, or not	1105	If the program is not event-based, it need not do anything special, even
977	do anything special (it does not need to be event-based) and let AnyEvent	1106	when it depends on a module that uses an AnyEvent. If the program itself
978	decide which implementation to chose if some module relies on it.	1107	uses AnyEvent, but does not care which event loop is used, all it needs
		1108	to do is C<use AnyEvent>. In either case, AnyEvent will choose the best
		1109	available loop implementation.
979		1110
980	If the main program relies on a specific event model - for example, in	1111	If the main program relies on a specific event model - for example, in
981	Gtk2 programs you have to rely on the Glib module - you should load the	1112	Gtk2 programs you have to rely on the Glib module - you should load the
982	event module before loading AnyEvent or any module that uses it: generally	1113	event module before loading AnyEvent or any module that uses it: generally
983	speaking, you should load it as early as possible. The reason is that	1114	speaking, you should load it as early as possible. The reason is that
984	modules might create watchers when they are loaded, and AnyEvent will	1115	modules might create watchers when they are loaded, and AnyEvent will
985	decide on the event model to use as soon as it creates watchers, and it	1116	decide on the event model to use as soon as it creates watchers, and it
986	might chose the wrong one unless you load the correct one yourself.	1117	might choose the wrong one unless you load the correct one yourself.
987		1118
988	You can chose to use a pure-perl implementation by loading the	1119	You can chose to use a pure-perl implementation by loading the
989	C<AnyEvent::Impl::Perl> module, which gives you similar behaviour	1120	C<AnyEvent::Loop> module, which gives you similar behaviour
990	everywhere, but letting AnyEvent chose the model is generally better.	1121	everywhere, but letting AnyEvent chose the model is generally better.
991		1122
992	=head2 MAINLOOP EMULATION	1123	=head2 MAINLOOP EMULATION
993		1124
994	Sometimes (often for short test scripts, or even standalone programs who	1125	Sometimes (often for short test scripts, or even standalone programs who
…		…
1007		1138
1008		1139
1009	=head1 OTHER MODULES	1140	=head1 OTHER MODULES
1010		1141
1011	The following is a non-exhaustive list of additional modules that use	1142	The following is a non-exhaustive list of additional modules that use
1012	AnyEvent as a client and can therefore be mixed easily with other AnyEvent	1143	AnyEvent as a client and can therefore be mixed easily with other
1013	modules and other event loops in the same program. Some of the modules	1144	AnyEvent modules and other event loops in the same program. Some of the
1014	come with AnyEvent, most are available via CPAN.	1145	modules come as part of AnyEvent, the others are available via CPAN (see
		1146	L<http://search.cpan.org/search?m=module&q=anyevent%3A%3A*> for
		1147	a longer non-exhaustive list), and the list is heavily biased towards
		1148	modules of the AnyEvent author himself :)
1015		1149
1016	=over 4	1150	=over 4
1017		1151
1018	=item L<AnyEvent::Util>	1152	=item L<AnyEvent::Util>
1019		1153
1020	Contains various utility functions that replace often-used but blocking	1154	Contains various utility functions that replace often-used blocking
1021	functions such as C<inet_aton> by event-/callback-based versions.	1155	functions such as C<inet_aton> with event/callback-based versions.
1022		1156
1023	=item L<AnyEvent::Socket>	1157	=item L<AnyEvent::Socket>
1024		1158
1025	Provides various utility functions for (internet protocol) sockets,	1159	Provides various utility functions for (internet protocol) sockets,
1026	addresses and name resolution. Also functions to create non-blocking tcp	1160	addresses and name resolution. Also functions to create non-blocking tcp
…		…
1028		1162
1029	=item L<AnyEvent::Handle>	1163	=item L<AnyEvent::Handle>
1030		1164
1031	Provide read and write buffers, manages watchers for reads and writes,	1165	Provide read and write buffers, manages watchers for reads and writes,
1032	supports raw and formatted I/O, I/O queued and fully transparent and	1166	supports raw and formatted I/O, I/O queued and fully transparent and
1033	non-blocking SSL/TLS (via L<AnyEvent::TLS>.	1167	non-blocking SSL/TLS (via L<AnyEvent::TLS>).
1034		1168
1035	=item L<AnyEvent::DNS>	1169	=item L<AnyEvent::DNS>
1036		1170
1037	Provides rich asynchronous DNS resolver capabilities.	1171	Provides rich asynchronous DNS resolver capabilities.
1038		1172
		1173	=item L<AnyEvent::HTTP>, L<AnyEvent::IRC>, L<AnyEvent::XMPP>, L<AnyEvent::GPSD>, L<AnyEvent::IGS>, L<AnyEvent::FCP>
		1174
		1175	Implement event-based interfaces to the protocols of the same name (for
		1176	the curious, IGS is the International Go Server and FCP is the Freenet
		1177	Client Protocol).
		1178
1039	=item L<AnyEvent::HTTP>	1179	=item L<AnyEvent::AIO>
1040		1180
1041	A simple-to-use HTTP library that is capable of making a lot of concurrent	1181	Truly asynchronous (as opposed to non-blocking) I/O, should be in the
1042	HTTP requests.	1182	toolbox of every event programmer. AnyEvent::AIO transparently fuses
		1183	L<IO::AIO> and AnyEvent together, giving AnyEvent access to event-based
		1184	file I/O, and much more.
		1185
		1186	=item L<AnyEvent::Filesys::Notify>
		1187
		1188	AnyEvent is good for non-blocking stuff, but it can't detect file or
		1189	path changes (e.g. "watch this directory for new files", "watch this
		1190	file for changes"). The L<AnyEvent::Filesys::Notify> module promises to
		1191	do just that in a portbale fashion, supporting inotify on GNU/Linux and
		1192	some weird, without doubt broken, stuff on OS X to monitor files. It can
		1193	fall back to blocking scans at regular intervals transparently on other
		1194	platforms, so it's about as portable as it gets.
		1195
		1196	(I haven't used it myself, but I haven't heard anybody complaining about
		1197	it yet).
		1198
		1199	=item L<AnyEvent::DBI>
		1200
		1201	Executes L<DBI> requests asynchronously in a proxy process for you,
		1202	notifying you in an event-based way when the operation is finished.
1043		1203
1044	=item L<AnyEvent::HTTPD>	1204	=item L<AnyEvent::HTTPD>
1045		1205
1046	Provides a simple web application server framework.	1206	A simple embedded webserver.
1047		1207
1048	=item L<AnyEvent::FastPing>	1208	=item L<AnyEvent::FastPing>
1049		1209
1050	The fastest ping in the west.	1210	The fastest ping in the west.
1051		1211
1052	=item L<AnyEvent::DBI>
1053
1054	Executes L<DBI> requests asynchronously in a proxy process.
1055
1056	=item L<AnyEvent::AIO>
1057
1058	Truly asynchronous I/O, should be in the toolbox of every event
1059	programmer. AnyEvent::AIO transparently fuses L<IO::AIO> and AnyEvent
1060	together.
1061
1062	=item L<AnyEvent::BDB>
1063
1064	Truly asynchronous Berkeley DB access. AnyEvent::BDB transparently fuses
1065	L<BDB> and AnyEvent together.
1066
1067	=item L<AnyEvent::GPSD>
1068
1069	A non-blocking interface to gpsd, a daemon delivering GPS information.
1070
1071	=item L<AnyEvent::IRC>
1072
1073	AnyEvent based IRC client module family (replacing the older Net::IRC3).
1074
1075	=item L<AnyEvent::XMPP>
1076
1077	AnyEvent based XMPP (Jabber protocol) module family (replacing the older
1078	Net::XMPP2>.
1079
1080	=item L<AnyEvent::IGS>
1081
1082	A non-blocking interface to the Internet Go Server protocol (used by
1083	L<App::IGS>).
1084
1085	=item L<Net::FCP>
1086
1087	AnyEvent-based implementation of the Freenet Client Protocol, birthplace
1088	of AnyEvent.
1089
1090	=item L<Event::ExecFlow>
1091
1092	High level API for event-based execution flow control.
1093
1094	=item L<Coro>	1212	=item L<Coro>
1095		1213
1096	Has special support for AnyEvent via L<Coro::AnyEvent>.	1214	Has special support for AnyEvent via L<Coro::AnyEvent>, which allows you
		1215	to simply invert the flow control - don't call us, we will call you:
		1216
		1217	async {
		1218	Coro::AnyEvent::sleep 5; # creates a 5s timer and waits for it
		1219	print "5 seconds later!\n";
		1220
		1221	Coro::AnyEvent::readable *STDIN; # uses an I/O watcher
		1222	my $line = <STDIN>; # works for ttys
		1223
		1224	AnyEvent::HTTP::http_get "url", Coro::rouse_cb;
		1225	my ($body, $hdr) = Coro::rouse_wait;
		1226	};
1097		1227
1098	=back	1228	=back
1099		1229
1100	=cut	1230	=cut
1101		1231
1102	package AnyEvent;	1232	package AnyEvent;
1103		1233
1104	# basically a tuned-down version of common::sense	1234	# basically a tuned-down version of common::sense
1105	sub common_sense {	1235	sub common_sense {
1106	# no warnings	1236	# from common:.sense 3.5
1107	${^WARNING_BITS} ^= ${^WARNING_BITS};	1237	local $^W;
1108	# use strict vars subs	1238	${^WARNING_BITS} ^= ${^WARNING_BITS} ^ "\x3c\x3f\x33\x00\x0f\xf0\x0f\xc0\xf0\xfc\x33\x00";
		1239	# use strict vars subs - NO UTF-8, as Util.pm doesn't like this atm. (uts46data.pl)
1109	$^H |= 0x00000600;	1240	$^H |= 0x00000600;
1110	}	1241	}
1111		1242
1112	BEGIN { AnyEvent::common_sense }	1243	BEGIN { AnyEvent::common_sense }
1113		1244
1114	use Carp ();	1245	use Carp ();
1115		1246
1116	our $VERSION = 4.881;	1247	our $VERSION = '7.04';
1117	our $MODEL;	1248	our $MODEL;
1118
1119	our $AUTOLOAD;
1120	our @ISA;	1249	our @ISA;
1121
1122	our @REGISTRY;	1250	our @REGISTRY;
1123
1124	our $WIN32;
1125
1126	our $VERBOSE;	1251	our $VERBOSE;
		1252	our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred
		1253	our $MAX_SIGNAL_LATENCY = $ENV{PERL_ANYEVENT_MAX_SIGNAL_LATENCY} || 10; # executes after the BEGIN block below (tainting!)
1127		1254
1128	BEGIN {	1255	BEGIN {
1129	eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }";	1256	require "AnyEvent/constants.pl";
		1257
1130	eval "sub TAINT(){ " . (${^TAINT}*1) . " }";	1258	eval "sub TAINT (){" . (${^TAINT}*1) . "}";
1131		1259
1132	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}	1260	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}
1133	if ${^TAINT};	1261	if ${^TAINT};
1134		1262
1135	$VERBOSE = $ENV{PERL_ANYEVENT_VERBOSE}*1;	1263	$ENV{"PERL_ANYEVENT_$_"} = $ENV{"AE_$_"}
		1264	for grep s/^AE_// && !exists $ENV{"PERL_ANYEVENT_$_"}, keys %ENV;
1136		1265
1137	}	1266	@ENV{grep /^PERL_ANYEVENT_/, keys %ENV} = ()
		1267	if ${^TAINT};
1138		1268
1139	our $MAX_SIGNAL_LATENCY = 10;	1269	# $ENV{PERL_ANYEVENT_xxx} now valid
1140		1270
1141	our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred	1271	$VERBOSE = length $ENV{PERL_ANYEVENT_VERBOSE} ? $ENV{PERL_ANYEVENT_VERBOSE}*1 : 4;
1142		1272
1143	{
1144	my $idx;	1273	my $idx;
1145	$PROTOCOL{$_} = ++$idx	1274	$PROTOCOL{$_} = ++$idx
1146	for reverse split /\s*,\s*/,	1275	for reverse split /\s*,\s*/,
1147	$ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";	1276	$ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";
1148	}	1277	}
1149		1278
		1279	our @post_detect;
		1280
		1281	sub post_detect(&) {
		1282	my ($cb) = @_;
		1283
		1284	push @post_detect, $cb;
		1285
		1286	defined wantarray
		1287	? bless \$cb, "AnyEvent::Util::postdetect"
		1288	: ()
		1289	}
		1290
		1291	sub AnyEvent::Util::postdetect::DESTROY {
		1292	@post_detect = grep $_ != ${$_[0]}, @post_detect;
		1293	}
		1294
		1295	our $POSTPONE_W;
		1296	our @POSTPONE;
		1297
		1298	sub _postpone_exec {
		1299	undef $POSTPONE_W;
		1300
		1301	&{ shift @POSTPONE }
		1302	while @POSTPONE;
		1303	}
		1304
		1305	sub postpone(&) {
		1306	push @POSTPONE, shift;
		1307
		1308	$POSTPONE_W ||= AE::timer (0, 0, \&_postpone_exec);
		1309
		1310	()
		1311	}
		1312
		1313	sub log($$;@) {
		1314	# only load the big bloated module when we actually are about to log something
		1315	if ($_[0] <= ($VERBOSE || 1)) { # also catches non-numeric levels(!) and fatal
		1316	local ($!, $@);
		1317	require AnyEvent::Log; # among other things, sets $VERBOSE to 9
		1318	# AnyEvent::Log overwrites this function
		1319	goto &log;
		1320	}
		1321
		1322	0 # not logged
		1323	}
		1324
		1325	sub _logger($;$) {
		1326	my ($level, $renabled) = @_;
		1327
		1328	$$renabled = $level <= $VERBOSE;
		1329
		1330	my $logger = [(caller)[0], $level, $renabled];
		1331
		1332	$AnyEvent::Log::LOGGER{$logger+0} = $logger;
		1333
		1334	# return unless defined wantarray;
		1335	#
		1336	# require AnyEvent::Util;
		1337	# my $guard = AnyEvent::Util::guard (sub {
		1338	# # "clean up"
		1339	# delete $LOGGER{$logger+0};
		1340	# });
		1341	#
		1342	# sub {
		1343	# return 0 unless $$renabled;
		1344	#
		1345	# $guard if 0; # keep guard alive, but don't cause runtime overhead
		1346	# require AnyEvent::Log unless $AnyEvent::Log::VERSION;
		1347	# package AnyEvent::Log;
		1348	# _log ($logger->[0], $level, @_) # logger->[0] has been converted at load time
		1349	# }
		1350	}
		1351
		1352	if (length $ENV{PERL_ANYEVENT_LOG}) {
		1353	require AnyEvent::Log; # AnyEvent::Log does the thing for us
		1354	}
		1355
1150	my @models = (	1356	our @models = (
1151	[EV:: => AnyEvent::Impl::EV:: , 1],	1357	[EV:: => AnyEvent::Impl::EV::],
1152	[Event:: => AnyEvent::Impl::Event::, 1],	1358	[AnyEvent::Loop:: => AnyEvent::Impl::Perl::],
1153	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl:: , 1],
1154	# everything below here will not (normally) be autoprobed	1359	# everything below here will not (normally) be autoprobed
1155	# as the pureperl backend should work everywhere	1360	# as the pure perl backend should work everywhere
1156	# and is usually faster	1361	# and is usually faster
		1362	[Irssi:: => AnyEvent::Impl::Irssi::], # Irssi has a bogus "Event" package, so msut be near the top
		1363	[Event:: => AnyEvent::Impl::Event::], # slow, stable
1157	[Glib:: => AnyEvent::Impl::Glib:: , 1], # becomes extremely slow with many watchers	1364	[Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers
		1365	# everything below here should not be autoloaded
1158	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy	1366	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
1159	[Irssi:: => AnyEvent::Impl::Irssi::], # Irssi has a bogus "Event" package
1160	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles	1367	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
1161	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program	1368	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program
1162	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza	1369	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
1163	[Wx:: => AnyEvent::Impl::POE::],	1370	[Wx:: => AnyEvent::Impl::POE::],
1164	[Prima:: => AnyEvent::Impl::POE::],	1371	[Prima:: => AnyEvent::Impl::POE::],
1165	# IO::Async is just too broken - we would need workarounds for its	1372	[IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # a bitch to autodetect
1166	# byzantine signal and broken child handling, among others.	1373	[Cocoa::EventLoop:: => AnyEvent::Impl::Cocoa::],
1167	# IO::Async is rather hard to detect, as it doesn't have any	1374	[FLTK:: => AnyEvent::Impl::FLTK::],
1168	# obvious default class.
1169	# [0, IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program
1170	# [0, IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program
1171	# [0, IO::Async::Notifier:: => AnyEvent::Impl::IOAsync::], # requires special main program
1172	);	1375	);
1173		1376
1174	our %method = map +($_ => 1),	1377	our @isa_hook;
		1378
		1379	sub _isa_set {
		1380	my @pkg = ("AnyEvent", (map $_->[0], grep defined, @isa_hook), $MODEL);
		1381
		1382	@{"$pkg[$_-1]::ISA"} = $pkg[$_]
		1383	for 1 .. $#pkg;
		1384
		1385	grep $_ && $_->[1], @isa_hook
		1386	and AE::_reset ();
		1387	}
		1388
		1389	# used for hooking AnyEvent::Strict and AnyEvent::Debug::Wrap into the class hierarchy
		1390	sub _isa_hook($$;$) {
		1391	my ($i, $pkg, $reset_ae) = @_;
		1392
		1393	$isa_hook[$i] = $pkg ? [$pkg, $reset_ae] : undef;
		1394
		1395	_isa_set;
		1396	}
		1397
		1398	# all autoloaded methods reserve the complete glob, not just the method slot.
		1399	# due to bugs in perls method cache implementation.
1175	qw(io timer time now now_update signal child idle condvar one_event DESTROY);	1400	our @methods = qw(io timer time now now_update signal child idle condvar);
1176		1401
1177	our @post_detect;
1178
1179	sub post_detect(&) {	1402	sub detect() {
1180	my ($cb) = @_;	1403	return $MODEL if $MODEL; # some programs keep references to detect
1181		1404
1182	if ($MODEL) {	1405	# IO::Async::Loop::AnyEvent is extremely evil, refuse to work with it
1183	$cb->();	1406	# the author knows about the problems and what it does to AnyEvent as a whole
		1407	# (and the ability of others to use AnyEvent), but simply wants to abuse AnyEvent
		1408	# anyway.
		1409	AnyEvent::log fatal => "IO::Async::Loop::AnyEvent detected - that module is broken by\n"
		1410	. "design, abuses internals and breaks AnyEvent - will not continue."
		1411	if exists $INC{"IO/Async/Loop/AnyEvent.pm"};
1184		1412
1185	undef	1413	local $!; # for good measure
		1414	local $SIG{__DIE__}; # we use eval
		1415
		1416	# free some memory
		1417	*detect = sub () { $MODEL };
		1418	# undef &func doesn't correctly update the method cache. grmbl.
		1419	# so we delete the whole glob. grmbl.
		1420	# otoh, perl doesn't let me undef an active usb, but it lets me free
		1421	# a glob with an active sub. hrm. i hope it works, but perl is
		1422	# usually buggy in this department. sigh.
		1423	delete @{"AnyEvent::"}{@methods};
		1424	undef @methods;
		1425
		1426	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z0-9:]+)$/) {
		1427	my $model = $1;
		1428	$model = "AnyEvent::Impl::$model" unless $model =~ s/::$//;
		1429	if (eval "require $model") {
		1430	AnyEvent::log 7 => "Loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.";
		1431	$MODEL = $model;
1186	} else {	1432	} else {
1187	push @post_detect, $cb;	1433	AnyEvent::log 4 => "Unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@";
1188		1434	}
1189	defined wantarray
1190	? bless \$cb, "AnyEvent::Util::postdetect"
1191	: ()
1192	}	1435	}
1193	}
1194		1436
1195	sub AnyEvent::Util::postdetect::DESTROY {	1437	# check for already loaded models
1196	@post_detect = grep $_ != ${$_[0]}, @post_detect;
1197	}
1198
1199	sub detect() {
1200	unless ($MODEL) {	1438	unless ($MODEL) {
1201	local $SIG{__DIE__};	1439	for (@REGISTRY, @models) {
1202		1440	my ($package, $model) = @$_;
1203	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {	1441	if (${"$package\::VERSION"} > 0) {
1204	my $model = "AnyEvent::Impl::$1";
1205	if (eval "require $model") {	1442	if (eval "require $model") {
		1443	AnyEvent::log 7 => "Autodetected model '$model', using it.";
1206	$MODEL = $model;	1444	$MODEL = $model;
1207	warn "AnyEvent: loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.\n" if $VERBOSE >= 2;	1445	last;
1208	} else {	1446	} else {
1209	warn "AnyEvent: unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@" if $VERBOSE;	1447	AnyEvent::log 8 => "Detected event loop $package, but cannot load '$model', skipping: $@";
		1448	}
1210	}	1449	}
1211	}	1450	}
1212		1451
1213	# check for already loaded models
1214	unless ($MODEL) {	1452	unless ($MODEL) {
		1453	# try to autoload a model
1215	for (@REGISTRY, @models) {	1454	for (@REGISTRY, @models) {
1216	my ($package, $model) = @$_;	1455	my ($package, $model) = @$_;
		1456	if (
		1457	eval "require $package"
1217	if (${"$package\::VERSION"} > 0) {	1458	and ${"$package\::VERSION"} > 0
1218	if (eval "require $model") {	1459	and eval "require $model"
		1460	) {
		1461	AnyEvent::log 7 => "Autoloaded model '$model', using it.";
1219	$MODEL = $model;	1462	$MODEL = $model;
1220	warn "AnyEvent: autodetected model '$model', using it.\n" if $VERBOSE >= 2;
1221	last;	1463	last;
1222	}
1223	}	1464	}
1224	}	1465	}
1225		1466
1226	unless ($MODEL) {
1227	# try to autoload a model
1228	for (@REGISTRY, @models) {
1229	my ($package, $model, $autoload) = @$_;
1230	if (
1231	$autoload
1232	and eval "require $package"
1233	and ${"$package\::VERSION"} > 0
1234	and eval "require $model"
1235	) {
1236	$MODEL = $model;
1237	warn "AnyEvent: autoloaded model '$model', using it.\n" if $VERBOSE >= 2;
1238	last;
1239	}
1240	}
1241
1242	$MODEL	1467	$MODEL
1243	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.\n";	1468	or AnyEvent::log fatal => "Backend autodetection failed - did you properly install AnyEvent?";
1244	}
1245	}	1469	}
1246
1247	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
1248
1249	unshift @ISA, $MODEL;
1250
1251	require AnyEvent::Strict if $ENV{PERL_ANYEVENT_STRICT};
1252
1253	(shift @post_detect)->() while @post_detect;
1254	}	1470	}
1255		1471
		1472	# free memory only needed for probing
		1473	undef @models;
		1474	undef @REGISTRY;
		1475
		1476	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
		1477
		1478	# now nuke some methods that are overridden by the backend.
		1479	# SUPER usage is not allowed in these.
		1480	for (qw(time signal child idle)) {
		1481	undef &{"AnyEvent::Base::$_"}
		1482	if defined &{"$MODEL\::$_"};
		1483	}
		1484
		1485	_isa_set;
		1486
		1487	# we're officially open!
		1488
		1489	if ($ENV{PERL_ANYEVENT_STRICT}) {
		1490	require AnyEvent::Strict;
		1491	}
		1492
		1493	if ($ENV{PERL_ANYEVENT_DEBUG_WRAP}) {
		1494	require AnyEvent::Debug;
		1495	AnyEvent::Debug::wrap ($ENV{PERL_ANYEVENT_DEBUG_WRAP});
		1496	}
		1497
		1498	if (length $ENV{PERL_ANYEVENT_DEBUG_SHELL}) {
		1499	require AnyEvent::Socket;
		1500	require AnyEvent::Debug;
		1501
		1502	my $shell = $ENV{PERL_ANYEVENT_DEBUG_SHELL};
		1503	$shell =~ s/\$\$/$$/g;
		1504
		1505	my ($host, $service) = AnyEvent::Socket::parse_hostport ($shell);
		1506	$AnyEvent::Debug::SHELL = AnyEvent::Debug::shell ($host, $service);
		1507	}
		1508
		1509	# now the anyevent environment is set up as the user told us to, so
		1510	# call the actual user code - post detects
		1511
		1512	(shift @post_detect)->() while @post_detect;
		1513	undef @post_detect;
		1514
		1515	*post_detect = sub(&) {
		1516	shift->();
		1517
		1518	undef
		1519	};
		1520
1256	$MODEL	1521	$MODEL
1257	}	1522	}
1258		1523
1259	sub AUTOLOAD {	1524	for my $name (@methods) {
1260	(my $func = $AUTOLOAD) =~ s/.*://;	1525	*$name = sub {
1261		1526	detect;
1262	$method{$func}	1527	# we use goto because
1263	or Carp::croak "$func: not a valid method for AnyEvent objects";	1528	# a) it makes the thunk more transparent
1264		1529	# b) it allows us to delete the thunk later
1265	detect unless $MODEL;	1530	goto &{ UNIVERSAL::can AnyEvent => "SUPER::$name" }
1266		1531	};
1267	my $class = shift;
1268	$class->$func (@_);
1269	}	1532	}
1270		1533
1271	# utility function to dup a filehandle. this is used by many backends	1534	# utility function to dup a filehandle. this is used by many backends
1272	# to support binding more than one watcher per filehandle (they usually	1535	# to support binding more than one watcher per filehandle (they usually
1273	# allow only one watcher per fd, so we dup it to get a different one).	1536	# allow only one watcher per fd, so we dup it to get a different one).
…		…
1283	# we assume CLOEXEC is already set by perl in all important cases	1546	# we assume CLOEXEC is already set by perl in all important cases
1284		1547
1285	($fh2, $rw)	1548	($fh2, $rw)
1286	}	1549	}
1287		1550
		1551	=head1 SIMPLIFIED AE API
		1552
		1553	Starting with version 5.0, AnyEvent officially supports a second, much
		1554	simpler, API that is designed to reduce the calling, typing and memory
		1555	overhead by using function call syntax and a fixed number of parameters.
		1556
		1557	See the L<AE> manpage for details.
		1558
		1559	=cut
		1560
		1561	package AE;
		1562
		1563	our $VERSION = $AnyEvent::VERSION;
		1564
		1565	sub _reset() {
		1566	eval q{
		1567	# fall back to the main API by default - backends and AnyEvent::Base
		1568	# implementations can overwrite these.
		1569
		1570	sub io($$$) {
		1571	AnyEvent->io (fh => $_[0], poll => $_[1] ? "w" : "r", cb => $_[2])
		1572	}
		1573
		1574	sub timer($$$) {
		1575	AnyEvent->timer (after => $_[0], interval => $_[1], cb => $_[2])
		1576	}
		1577
		1578	sub signal($$) {
		1579	AnyEvent->signal (signal => $_[0], cb => $_[1])
		1580	}
		1581
		1582	sub child($$) {
		1583	AnyEvent->child (pid => $_[0], cb => $_[1])
		1584	}
		1585
		1586	sub idle($) {
		1587	AnyEvent->idle (cb => $_[0]);
		1588	}
		1589
		1590	sub cv(;&) {
		1591	AnyEvent->condvar (@_ ? (cb => $_[0]) : ())
		1592	}
		1593
		1594	sub now() {
		1595	AnyEvent->now
		1596	}
		1597
		1598	sub now_update() {
		1599	AnyEvent->now_update
		1600	}
		1601
		1602	sub time() {
		1603	AnyEvent->time
		1604	}
		1605
		1606	*postpone = \&AnyEvent::postpone;
		1607	*log = \&AnyEvent::log;
		1608	};
		1609	die if $@;
		1610	}
		1611
		1612	BEGIN { _reset }
		1613
1288	package AnyEvent::Base;	1614	package AnyEvent::Base;
1289		1615
1290	# default implementations for many methods	1616	# default implementations for many methods
1291		1617
1292	sub _time {	1618	sub time {
		1619	eval q{ # poor man's autoloading {}
1293	# probe for availability of Time::HiRes	1620	# probe for availability of Time::HiRes
1294	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {	1621	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {
1295	warn "AnyEvent: using Time::HiRes for sub-second timing accuracy.\n" if $VERBOSE >= 8;	1622	*time = sub { Time::HiRes::time () };
1296	*_time = \&Time::HiRes::time;	1623	*AE::time = \& Time::HiRes::time ;
		1624	*now = \&time;
		1625	AnyEvent::log 8 => "using Time::HiRes for sub-second timing accuracy.";
1297	# if (eval "use POSIX (); (POSIX::times())...	1626	# if (eval "use POSIX (); (POSIX::times())...
1298	} else {	1627	} else {
1299	warn "AnyEvent: using built-in time(), WARNING, no sub-second resolution!\n" if $VERBOSE;	1628	*time = sub { CORE::time };
1300	*_time = sub { time }; # epic fail	1629	*AE::time = sub (){ CORE::time };
		1630	*now = \&time;
		1631	AnyEvent::log 3 => "Using built-in time(), no sub-second resolution!";
		1632	}
1301	}	1633	};
		1634	die if $@;
1302		1635
1303	&_time	1636	&time
1304	}	1637	}
1305		1638
1306	sub time { _time }	1639	*now = \&time;
1307	sub now { _time }
1308	sub now_update { }	1640	sub now_update { }
1309		1641
		1642	sub _poll {
		1643	Carp::croak "$AnyEvent::MODEL does not support blocking waits. Caught";
		1644	}
		1645
1310	# default implementation for ->condvar	1646	# default implementation for ->condvar
		1647	# in fact, the default should not be overwritten
1311		1648
1312	sub condvar {	1649	sub condvar {
		1650	eval q{ # poor man's autoloading {}
		1651	*condvar = sub {
1313	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"	1652	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"
		1653	};
		1654
		1655	*AE::cv = sub (;&) {
		1656	bless { @_ ? (_ae_cb => shift) : () }, "AnyEvent::CondVar"
		1657	};
		1658	};
		1659	die if $@;
		1660
		1661	&condvar
1314	}	1662	}
1315		1663
1316	# default implementation for ->signal	1664	# default implementation for ->signal
1317		1665
1318	our $HAVE_ASYNC_INTERRUPT;	1666	our $HAVE_ASYNC_INTERRUPT;
1319		1667
1320	sub _have_async_interrupt() {	1668	sub _have_async_interrupt() {
1321	$HAVE_ASYNC_INTERRUPT = 1*(!$ENV{PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT}	1669	$HAVE_ASYNC_INTERRUPT = 1*(!$ENV{PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT}
1322	&& eval "use Async::Interrupt 1.0 (); 1")	1670	&& eval "use Async::Interrupt 1.02 (); 1")
1323	unless defined $HAVE_ASYNC_INTERRUPT;	1671	unless defined $HAVE_ASYNC_INTERRUPT;
1324		1672
1325	$HAVE_ASYNC_INTERRUPT	1673	$HAVE_ASYNC_INTERRUPT
1326	}	1674	}
1327		1675
1328	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);	1676	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);
1329	our (%SIG_ASY, %SIG_ASY_W);	1677	our (%SIG_ASY, %SIG_ASY_W);
1330	our ($SIG_COUNT, $SIG_TW);	1678	our ($SIG_COUNT, $SIG_TW);
1331		1679
1332	sub _signal_exec {
1333	$HAVE_ASYNC_INTERRUPT
1334	? $SIGPIPE_R->drain
1335	: sysread $SIGPIPE_R, my $dummy, 9;
1336
1337	while (%SIG_EV) {
1338	for (keys %SIG_EV) {
1339	delete $SIG_EV{$_};
1340	$_->() for values %{ $SIG_CB{$_} || {} };
1341	}
1342	}
1343	}
1344
1345	# install a dummy wakeup watcher to reduce signal catching latency	1680	# install a dummy wakeup watcher to reduce signal catching latency
		1681	# used by Impls
1346	sub _sig_add() {	1682	sub _sig_add() {
1347	unless ($SIG_COUNT++) {	1683	unless ($SIG_COUNT++) {
1348	# try to align timer on a full-second boundary, if possible	1684	# try to align timer on a full-second boundary, if possible
1349	my $NOW = AnyEvent->now;	1685	my $NOW = AE::now;
1350		1686
1351	$SIG_TW = AnyEvent->timer (	1687	$SIG_TW = AE::timer
1352	after => $MAX_SIGNAL_LATENCY - ($NOW - int $NOW),	1688	$MAX_SIGNAL_LATENCY - ($NOW - int $NOW),
1353	interval => $MAX_SIGNAL_LATENCY,	1689	$MAX_SIGNAL_LATENCY,
1354	cb => sub { }, # just for the PERL_ASYNC_CHECK	1690	sub { } # just for the PERL_ASYNC_CHECK
1355	);	1691	;
1356	}	1692	}
1357	}	1693	}
1358		1694
1359	sub _sig_del {	1695	sub _sig_del {
1360	undef $SIG_TW	1696	undef $SIG_TW
1361	unless --$SIG_COUNT;	1697	unless --$SIG_COUNT;
1362	}	1698	}
1363		1699
1364	our $_sig_name_init; $_sig_name_init = sub {	1700	our $_sig_name_init; $_sig_name_init = sub {
1365	eval q{ # poor man's autoloading	1701	eval q{ # poor man's autoloading {}
1366	undef $_sig_name_init;	1702	undef $_sig_name_init;
1367		1703
1368	if (_have_async_interrupt) {	1704	if (_have_async_interrupt) {
1369	*sig2num = \&Async::Interrupt::sig2num;	1705	*sig2num = \&Async::Interrupt::sig2num;
1370	*sig2name = \&Async::Interrupt::sig2name;	1706	*sig2name = \&Async::Interrupt::sig2name;
…		…
1394		1730
1395	sub signal {	1731	sub signal {
1396	eval q{ # poor man's autoloading {}	1732	eval q{ # poor man's autoloading {}
1397	# probe for availability of Async::Interrupt	1733	# probe for availability of Async::Interrupt
1398	if (_have_async_interrupt) {	1734	if (_have_async_interrupt) {
1399	warn "AnyEvent: using Async::Interrupt for race-free signal handling.\n" if $VERBOSE >= 8;	1735	AnyEvent::log 8 => "Using Async::Interrupt for race-free signal handling.";
1400		1736
1401	$SIGPIPE_R = new Async::Interrupt::EventPipe;	1737	$SIGPIPE_R = new Async::Interrupt::EventPipe;
1402	$SIG_IO = AnyEvent->io (fh => $SIGPIPE_R->fileno, poll => "r", cb => \&_signal_exec);	1738	$SIG_IO = AE::io $SIGPIPE_R->fileno, 0, \&_signal_exec;
1403		1739
1404	} else {	1740	} else {
1405	warn "AnyEvent: using emulated perl signal handling with latency timer.\n" if $VERBOSE >= 8;	1741	AnyEvent::log 8 => "Using emulated perl signal handling with latency timer.";
1406
1407	require Fcntl;
1408		1742
1409	if (AnyEvent::WIN32) {	1743	if (AnyEvent::WIN32) {
1410	require AnyEvent::Util;	1744	require AnyEvent::Util;
1411		1745
1412	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();	1746	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
1413	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R, 1) if $SIGPIPE_R;	1747	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R, 1) if $SIGPIPE_R;
1414	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W, 1) if $SIGPIPE_W; # just in case	1748	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W, 1) if $SIGPIPE_W; # just in case
1415	} else {	1749	} else {
1416	pipe $SIGPIPE_R, $SIGPIPE_W;	1750	pipe $SIGPIPE_R, $SIGPIPE_W;
1417	fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R;	1751	fcntl $SIGPIPE_R, AnyEvent::F_SETFL, AnyEvent::O_NONBLOCK if $SIGPIPE_R;
1418	fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case	1752	fcntl $SIGPIPE_W, AnyEvent::F_SETFL, AnyEvent::O_NONBLOCK if $SIGPIPE_W; # just in case
1419		1753
1420	# not strictly required, as $^F is normally 2, but let's make sure...	1754	# not strictly required, as $^F is normally 2, but let's make sure...
1421	fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;	1755	fcntl $SIGPIPE_R, AnyEvent::F_SETFD, AnyEvent::FD_CLOEXEC;
1422	fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;	1756	fcntl $SIGPIPE_W, AnyEvent::F_SETFD, AnyEvent::FD_CLOEXEC;
1423	}	1757	}
1424		1758
1425	$SIGPIPE_R	1759	$SIGPIPE_R
1426	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";	1760	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";
1427		1761
1428	$SIG_IO = AnyEvent->io (fh => $SIGPIPE_R, poll => "r", cb => \&_signal_exec);	1762	$SIG_IO = AE::io $SIGPIPE_R, 0, \&_signal_exec;
1429	}	1763	}
1430		1764
1431	*signal = sub {	1765	*signal = $HAVE_ASYNC_INTERRUPT
		1766	? sub {
1432	my (undef, %arg) = @_;	1767	my (undef, %arg) = @_;
1433		1768
1434	my $signal = uc $arg{signal}
1435	or Carp::croak "required option 'signal' is missing";
1436
1437	if ($HAVE_ASYNC_INTERRUPT) {
1438	# async::interrupt	1769	# async::interrupt
1439
1440	$signal = sig2num $signal;	1770	my $signal = sig2num $arg{signal};
1441	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};	1771	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
1442		1772
1443	$SIG_ASY{$signal} ||= new Async::Interrupt	1773	$SIG_ASY{$signal} ||= new Async::Interrupt
1444	cb => sub { undef $SIG_EV{$signal} },	1774	cb => sub { undef $SIG_EV{$signal} },
1445	signal => $signal,	1775	signal => $signal,
1446	pipe => [$SIGPIPE_R->filenos],	1776	pipe => [$SIGPIPE_R->filenos],
1447	pipe_autodrain => 0,	1777	pipe_autodrain => 0,
1448	;	1778	;
1449		1779
1450	} else {	1780	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
		1781	}
		1782	: sub {
		1783	my (undef, %arg) = @_;
		1784
1451	# pure perl	1785	# pure perl
1452
1453	# AE::Util has been loaded in signal
1454	$signal = sig2name $signal;	1786	my $signal = sig2name $arg{signal};
1455	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};	1787	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
1456		1788
1457	$SIG{$signal} ||= sub {	1789	$SIG{$signal} ||= sub {
1458	local $!;	1790	local $!;
1459	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;	1791	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;
1460	undef $SIG_EV{$signal};	1792	undef $SIG_EV{$signal};
1461	};	1793	};
1462		1794
1463	# can't do signal processing without introducing races in pure perl,	1795	# can't do signal processing without introducing races in pure perl,
1464	# so limit the signal latency.	1796	# so limit the signal latency.
1465	_sig_add;	1797	_sig_add;
1466	}
1467		1798
1468	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"	1799	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
		1800	}
1469	};	1801	;
1470		1802
1471	*AnyEvent::Base::signal::DESTROY = sub {	1803	*AnyEvent::Base::signal::DESTROY = sub {
1472	my ($signal, $cb) = @{$_[0]};	1804	my ($signal, $cb) = @{$_[0]};
1473		1805
1474	_sig_del;	1806	_sig_del;
…		…
1481	# print weird messages, or just unconditionally exit	1813	# print weird messages, or just unconditionally exit
1482	# instead of getting the default action.	1814	# instead of getting the default action.
1483	undef $SIG{$signal}	1815	undef $SIG{$signal}
1484	unless keys %{ $SIG_CB{$signal} };	1816	unless keys %{ $SIG_CB{$signal} };
1485	};	1817	};
		1818
		1819	*_signal_exec = sub {
		1820	$HAVE_ASYNC_INTERRUPT
		1821	? $SIGPIPE_R->drain
		1822	: sysread $SIGPIPE_R, (my $dummy), 9;
		1823
		1824	while (%SIG_EV) {
		1825	for (keys %SIG_EV) {
		1826	delete $SIG_EV{$_};
		1827	&$_ for values %{ $SIG_CB{$_} || {} };
		1828	}
		1829	}
		1830	};
1486	};	1831	};
1487	die if $@;	1832	die if $@;
		1833
1488	&signal	1834	&signal
1489	}	1835	}
1490		1836
1491	# default implementation for ->child	1837	# default implementation for ->child
1492		1838
1493	our %PID_CB;	1839	our %PID_CB;
1494	our $CHLD_W;	1840	our $CHLD_W;
1495	our $CHLD_DELAY_W;	1841	our $CHLD_DELAY_W;
1496	our $WNOHANG;
1497		1842
		1843	# used by many Impl's
1498	sub _emit_childstatus($$) {	1844	sub _emit_childstatus($$) {
1499	my (undef, $rpid, $rstatus) = @_;	1845	my (undef, $rpid, $rstatus) = @_;
1500		1846
1501	$_->($rpid, $rstatus)	1847	$_->($rpid, $rstatus)
1502	for values %{ $PID_CB{$rpid} || {} },	1848	for values %{ $PID_CB{$rpid} || {} },
1503	values %{ $PID_CB{0} || {} };	1849	values %{ $PID_CB{0} || {} };
1504	}	1850	}
1505		1851
1506	sub _sigchld {
1507	my $pid;
1508
1509	AnyEvent->_emit_childstatus ($pid, $?)
1510	while ($pid = waitpid -1, $WNOHANG) > 0;
1511	}
1512
1513	sub child {	1852	sub child {
		1853	eval q{ # poor man's autoloading {}
		1854	*_sigchld = sub {
		1855	my $pid;
		1856
		1857	AnyEvent->_emit_childstatus ($pid, $?)
		1858	while ($pid = waitpid -1, WNOHANG) > 0;
		1859	};
		1860
		1861	*child = sub {
1514	my (undef, %arg) = @_;	1862	my (undef, %arg) = @_;
1515		1863
1516	defined (my $pid = $arg{pid} + 0)	1864	my $pid = $arg{pid};
1517	or Carp::croak "required option 'pid' is missing";	1865	my $cb = $arg{cb};
1518		1866
1519	$PID_CB{$pid}{$arg{cb}} = $arg{cb};	1867	$PID_CB{$pid}{$cb+0} = $cb;
1520		1868
1521	# WNOHANG is almost cetrainly 1 everywhere
1522	$WNOHANG ||= $^O =~ /^(?:openbsd|netbsd|linux|freebsd|cygwin|MSWin32)$/
1523	? 1
1524	: eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1;
1525
1526	unless ($CHLD_W) {	1869	unless ($CHLD_W) {
1527	$CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld);	1870	$CHLD_W = AE::signal CHLD => \&_sigchld;
1528	# child could be a zombie already, so make at least one round	1871	# child could be a zombie already, so make at least one round
1529	&_sigchld;	1872	&_sigchld;
1530	}	1873	}
1531		1874
1532	bless [$pid, $arg{cb}], "AnyEvent::Base::child"	1875	bless [$pid, $cb+0], "AnyEvent::Base::child"
1533	}	1876	};
1534		1877
1535	sub AnyEvent::Base::child::DESTROY {	1878	*AnyEvent::Base::child::DESTROY = sub {
1536	my ($pid, $cb) = @{$_[0]};	1879	my ($pid, $icb) = @{$_[0]};
1537		1880
1538	delete $PID_CB{$pid}{$cb};	1881	delete $PID_CB{$pid}{$icb};
1539	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };	1882	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };
1540		1883
1541	undef $CHLD_W unless keys %PID_CB;	1884	undef $CHLD_W unless keys %PID_CB;
		1885	};
		1886	};
		1887	die if $@;
		1888
		1889	&child
1542	}	1890	}
1543		1891
1544	# idle emulation is done by simply using a timer, regardless	1892	# idle emulation is done by simply using a timer, regardless
1545	# of whether the process is idle or not, and not letting	1893	# of whether the process is idle or not, and not letting
1546	# the callback use more than 50% of the time.	1894	# the callback use more than 50% of the time.
1547	sub idle {	1895	sub idle {
		1896	eval q{ # poor man's autoloading {}
		1897	*idle = sub {
1548	my (undef, %arg) = @_;	1898	my (undef, %arg) = @_;
1549		1899
1550	my ($cb, $w, $rcb) = $arg{cb};	1900	my ($cb, $w, $rcb) = $arg{cb};
1551		1901
1552	$rcb = sub {	1902	$rcb = sub {
1553	if ($cb) {	1903	if ($cb) {
1554	$w = _time;	1904	$w = AE::time;
1555	&$cb;	1905	&$cb;
1556	$w = _time - $w;	1906	$w = AE::time - $w;
1557		1907
1558	# never use more then 50% of the time for the idle watcher,	1908	# never use more then 50% of the time for the idle watcher,
1559	# within some limits	1909	# within some limits
1560	$w = 0.0001 if $w < 0.0001;	1910	$w = 0.0001 if $w < 0.0001;
1561	$w = 5 if $w > 5;	1911	$w = 5 if $w > 5;
1562		1912
1563	$w = AnyEvent->timer (after => $w, cb => $rcb);	1913	$w = AE::timer $w, 0, $rcb;
1564	} else {	1914	} else {
1565	# clean up...	1915	# clean up...
1566	undef $w;	1916	undef $w;
1567	undef $rcb;	1917	undef $rcb;
		1918	}
		1919	};
		1920
		1921	$w = AE::timer 0.05, 0, $rcb;
		1922
		1923	bless \\$cb, "AnyEvent::Base::idle"
1568	}	1924	};
		1925
		1926	*AnyEvent::Base::idle::DESTROY = sub {
		1927	undef $${$_[0]};
		1928	};
1569	};	1929	};
		1930	die if $@;
1570		1931
1571	$w = AnyEvent->timer (after => 0.05, cb => $rcb);	1932	&idle
1572
1573	bless \\$cb, "AnyEvent::Base::idle"
1574	}
1575
1576	sub AnyEvent::Base::idle::DESTROY {
1577	undef $${$_[0]};
1578	}	1933	}
1579		1934
1580	package AnyEvent::CondVar;	1935	package AnyEvent::CondVar;
1581		1936
1582	our @ISA = AnyEvent::CondVar::Base::;	1937	our @ISA = AnyEvent::CondVar::Base::;
		1938
		1939	# only to be used for subclassing
		1940	sub new {
		1941	my $class = shift;
		1942	bless AnyEvent->condvar (@_), $class
		1943	}
1583		1944
1584	package AnyEvent::CondVar::Base;	1945	package AnyEvent::CondVar::Base;
1585		1946
1586	#use overload	1947	#use overload
1587	# '&{}' => sub { my $self = shift; sub { $self->send (@_) } },	1948	# '&{}' => sub { my $self = shift; sub { $self->send (@_) } },
…		…
1597		1958
1598	sub _send {	1959	sub _send {
1599	# nop	1960	# nop
1600	}	1961	}
1601		1962
		1963	sub _wait {
		1964	AnyEvent->_poll until $_[0]{_ae_sent};
		1965	}
		1966
1602	sub send {	1967	sub send {
1603	my $cv = shift;	1968	my $cv = shift;
1604	$cv->{_ae_sent} = [@_];	1969	$cv->{_ae_sent} = [@_];
1605	(delete $cv->{_ae_cb})->($cv) if $cv->{_ae_cb};	1970	(delete $cv->{_ae_cb})->($cv) if $cv->{_ae_cb};
1606	$cv->_send;	1971	$cv->_send;
…		…
1613		1978
1614	sub ready {	1979	sub ready {
1615	$_[0]{_ae_sent}	1980	$_[0]{_ae_sent}
1616	}	1981	}
1617		1982
1618	sub _wait {
1619	$WAITING
1620	and !$_[0]{_ae_sent}
1621	and Carp::croak "AnyEvent::CondVar: recursive blocking wait detected";
1622
1623	local $WAITING = 1;
1624	AnyEvent->one_event while !$_[0]{_ae_sent};
1625	}
1626
1627	sub recv {	1983	sub recv {
		1984	unless ($_[0]{_ae_sent}) {
		1985	$WAITING
		1986	and Carp::croak "AnyEvent::CondVar: recursive blocking wait attempted";
		1987
		1988	local $WAITING = 1;
1628	$_[0]->_wait;	1989	$_[0]->_wait;
		1990	}
1629		1991
1630	Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak};	1992	$_[0]{_ae_croak}
1631	wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0]	1993	and Carp::croak $_[0]{_ae_croak};
		1994
		1995	wantarray
		1996	? @{ $_[0]{_ae_sent} }
		1997	: $_[0]{_ae_sent}[0]
1632	}	1998	}
1633		1999
1634	sub cb {	2000	sub cb {
1635	$_[0]{_ae_cb} = $_[1] if @_ > 1;	2001	my $cv = shift;
		2002
		2003	@_
		2004	and $cv->{_ae_cb} = shift
		2005	and $cv->{_ae_sent}
		2006	and (delete $cv->{_ae_cb})->($cv);
		2007
1636	$_[0]{_ae_cb}	2008	$cv->{_ae_cb}
1637	}	2009	}
1638		2010
1639	sub begin {	2011	sub begin {
1640	++$_[0]{_ae_counter};	2012	++$_[0]{_ae_counter};
1641	$_[0]{_ae_end_cb} = $_[1] if @_ > 1;	2013	$_[0]{_ae_end_cb} = $_[1] if @_ > 1;
…		…
1646	&{ $_[0]{_ae_end_cb} || sub { $_[0]->send } };	2018	&{ $_[0]{_ae_end_cb} || sub { $_[0]->send } };
1647	}	2019	}
1648		2020
1649	# undocumented/compatibility with pre-3.4	2021	# undocumented/compatibility with pre-3.4
1650	*broadcast = \&send;	2022	*broadcast = \&send;
1651	*wait = \&_wait;	2023	*wait = \&recv;
1652
1653	#############################################################################
1654	# "new" API, currently only emulation of it
1655	#############################################################################
1656
1657	package AE;
1658
1659	sub io($$$) {
1660	AnyEvent->io (fh => $_[0], poll => $_[1] ? "w" : "r", cb => $_[2])
1661	}
1662
1663	sub timer($$$) {
1664	AnyEvent->timer (after => $_[0], interval => $_[1], cb => $_[2]);
1665	}
1666
1667	sub signal($$) {
1668	AnyEvent->signal (signal => $_[0], cb => $_[1]);
1669	}
1670
1671	sub child($$) {
1672	AnyEvent->child (pid => $_[0], cb => $_[1]);
1673	}
1674
1675	sub idle($) {
1676	AnyEvent->idle (cb => $_[0]);
1677	}
1678
1679	sub cv() {
1680	AnyEvent->condvar
1681	}
1682
1683	sub now() {
1684	AnyEvent->now
1685	}
1686
1687	sub now_update() {
1688	AnyEvent->now_update
1689	}
1690
1691	sub time() {
1692	AnyEvent->time
1693	}
1694		2024
1695	=head1 ERROR AND EXCEPTION HANDLING	2025	=head1 ERROR AND EXCEPTION HANDLING
1696		2026
1697	In general, AnyEvent does not do any error handling - it relies on the	2027	In general, AnyEvent does not do any error handling - it relies on the
1698	caller to do that if required. The L<AnyEvent::Strict> module (see also	2028	caller to do that if required. The L<AnyEvent::Strict> module (see also
…		…
1710	$Event/EV::DIED->() >>, L<Glib> uses C<< install_exception_handler >> and	2040	$Event/EV::DIED->() >>, L<Glib> uses C<< install_exception_handler >> and
1711	so on.	2041	so on.
1712		2042
1713	=head1 ENVIRONMENT VARIABLES	2043	=head1 ENVIRONMENT VARIABLES
1714		2044
1715	The following environment variables are used by this module or its	2045	AnyEvent supports a number of environment variables that tune the
1716	submodules.	2046	runtime behaviour. They are usually evaluated when AnyEvent is
		2047	loaded, initialised, or a submodule that uses them is loaded. Many of
		2048	them also cause AnyEvent to load additional modules - for example,
		2049	C<PERL_ANYEVENT_DEBUG_WRAP> causes the L<AnyEvent::Debug> module to be
		2050	loaded.
1717		2051
1718	Note that AnyEvent will remove I<all> environment variables starting with	2052	All the environment variables documented here start with
1719	C<PERL_ANYEVENT_> from C<%ENV> when it is loaded while taint mode is	2053	C<PERL_ANYEVENT_>, which is what AnyEvent considers its own
1720	enabled.	2054	namespace. Other modules are encouraged (but by no means required) to use
		2055	C<PERL_ANYEVENT_SUBMODULE> if they have registered the AnyEvent::Submodule
		2056	namespace on CPAN, for any submodule. For example, L<AnyEvent::HTTP> could
		2057	be expected to use C<PERL_ANYEVENT_HTTP_PROXY> (it should not access env
		2058	variables starting with C<AE_>, see below).
		2059
		2060	All variables can also be set via the C<AE_> prefix, that is, instead
		2061	of setting C<PERL_ANYEVENT_VERBOSE> you can also set C<AE_VERBOSE>. In
		2062	case there is a clash btween anyevent and another program that uses
		2063	C<AE_something> you can set the corresponding C<PERL_ANYEVENT_something>
		2064	variable to the empty string, as those variables take precedence.
		2065
		2066	When AnyEvent is first loaded, it copies all C<AE_xxx> env variables
		2067	to their C<PERL_ANYEVENT_xxx> counterpart unless that variable already
		2068	exists. If taint mode is on, then AnyEvent will remove I<all> environment
		2069	variables starting with C<PERL_ANYEVENT_> from C<%ENV> (or replace them
		2070	with C<undef> or the empty string, if the corresaponding C<AE_> variable
		2071	is set).
		2072
		2073	The exact algorithm is currently:
		2074
		2075	1. if taint mode enabled, delete all PERL_ANYEVENT_xyz variables from %ENV
		2076	2. copy over AE_xyz to PERL_ANYEVENT_xyz unless the latter alraedy exists
		2077	3. if taint mode enabled, set all PERL_ANYEVENT_xyz variables to undef.
		2078
		2079	This ensures that child processes will not see the C<AE_> variables.
		2080
		2081	The following environment variables are currently known to AnyEvent:
1721		2082
1722	=over 4	2083	=over 4
1723		2084
1724	=item C<PERL_ANYEVENT_VERBOSE>	2085	=item C<PERL_ANYEVENT_VERBOSE>
1725		2086
1726	By default, AnyEvent will be completely silent except in fatal	2087	By default, AnyEvent will log messages with loglevel C<4> (C<error>) or
1727	conditions. You can set this environment variable to make AnyEvent more	2088	higher (see L<AnyEvent::Log>). You can set this environment variable to a
1728	talkative.	2089	numerical loglevel to make AnyEvent more (or less) talkative.
1729		2090
		2091	If you want to do more than just set the global logging level
		2092	you should have a look at C<PERL_ANYEVENT_LOG>, which allows much more
		2093	complex specifications.
		2094
		2095	When set to C<0> (C<off>), then no messages whatsoever will be logged with
		2096	everything else at defaults.
		2097
1730	When set to C<1> or higher, causes AnyEvent to warn about unexpected	2098	When set to C<5> or higher (C<warn>), AnyEvent warns about unexpected
1731	conditions, such as not being able to load the event model specified by	2099	conditions, such as not being able to load the event model specified by
1732	C<PERL_ANYEVENT_MODEL>.	2100	C<PERL_ANYEVENT_MODEL>, or a guard callback throwing an exception - this
		2101	is the minimum recommended level for use during development.
1733		2102
1734	When set to C<2> or higher, cause AnyEvent to report to STDERR which event	2103	When set to C<7> or higher (info), AnyEvent reports which event model it
1735	model it chooses.	2104	chooses.
1736		2105
1737	When set to C<8> or higher, then AnyEvent will report extra information on	2106	When set to C<8> or higher (debug), then AnyEvent will report extra
1738	which optional modules it loads and how it implements certain features.	2107	information on which optional modules it loads and how it implements
		2108	certain features.
		2109
		2110	=item C<PERL_ANYEVENT_LOG>
		2111
		2112	Accepts rather complex logging specifications. For example, you could log
		2113	all C<debug> messages of some module to stderr, warnings and above to
		2114	stderr, and errors and above to syslog, with:
		2115
		2116	PERL_ANYEVENT_LOG=Some::Module=debug,+log:filter=warn,+%syslog:%syslog=error,syslog
		2117
		2118	For the rather extensive details, see L<AnyEvent::Log>.
		2119
		2120	This variable is evaluated when AnyEvent (or L<AnyEvent::Log>) is loaded,
		2121	so will take effect even before AnyEvent has initialised itself.
		2122
		2123	Note that specifying this environment variable causes the L<AnyEvent::Log>
		2124	module to be loaded, while C<PERL_ANYEVENT_VERBOSE> does not, so only
		2125	using the latter saves a few hundred kB of memory unless a module
		2126	explicitly needs the extra features of AnyEvent::Log.
1739		2127
1740	=item C<PERL_ANYEVENT_STRICT>	2128	=item C<PERL_ANYEVENT_STRICT>
1741		2129
1742	AnyEvent does not do much argument checking by default, as thorough	2130	AnyEvent does not do much argument checking by default, as thorough
1743	argument checking is very costly. Setting this variable to a true value	2131	argument checking is very costly. Setting this variable to a true value
…		…
1745	check the arguments passed to most method calls. If it finds any problems,	2133	check the arguments passed to most method calls. If it finds any problems,
1746	it will croak.	2134	it will croak.
1747		2135
1748	In other words, enables "strict" mode.	2136	In other words, enables "strict" mode.
1749		2137
1750	Unlike C<use strict> (or it's modern cousin, C<< use L<common::sense>	2138	Unlike C<use strict> (or its modern cousin, C<< use L<common::sense>
1751	>>, it is definitely recommended to keep it off in production. Keeping	2139	>>, it is definitely recommended to keep it off in production. Keeping
1752	C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs	2140	C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs
1753	can be very useful, however.	2141	can be very useful, however.
1754		2142
		2143	=item C<PERL_ANYEVENT_DEBUG_SHELL>
		2144
		2145	If this env variable is nonempty, then its contents will be interpreted by
		2146	C<AnyEvent::Socket::parse_hostport> and C<AnyEvent::Debug::shell> (after
		2147	replacing every occurance of C<$$> by the process pid). The shell object
		2148	is saved in C<$AnyEvent::Debug::SHELL>.
		2149
		2150	This happens when the first watcher is created.
		2151
		2152	For example, to bind a debug shell on a unix domain socket in
		2153	F<< /tmp/debug<pid>.sock >>, you could use this:
		2154
		2155	PERL_ANYEVENT_DEBUG_SHELL=/tmp/debug\$\$.sock perlprog
		2156	# connect with e.g.: socat readline /tmp/debug123.sock
		2157
		2158	Or to bind to tcp port 4545 on localhost:
		2159
		2160	PERL_ANYEVENT_DEBUG_SHELL=127.0.0.1:4545 perlprog
		2161	# connect with e.g.: telnet localhost 4545
		2162
		2163	Note that creating sockets in F</tmp> or on localhost is very unsafe on
		2164	multiuser systems.
		2165
		2166	=item C<PERL_ANYEVENT_DEBUG_WRAP>
		2167
		2168	Can be set to C<0>, C<1> or C<2> and enables wrapping of all watchers for
		2169	debugging purposes. See C<AnyEvent::Debug::wrap> for details.
		2170
1755	=item C<PERL_ANYEVENT_MODEL>	2171	=item C<PERL_ANYEVENT_MODEL>
1756		2172
1757	This can be used to specify the event model to be used by AnyEvent, before	2173	This can be used to specify the event model to be used by AnyEvent, before
1758	auto detection and -probing kicks in. It must be a string consisting	2174	auto detection and -probing kicks in.
1759	entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended	2175
		2176	It normally is a string consisting entirely of ASCII letters (e.g. C<EV>
		2177	or C<IOAsync>). The string C<AnyEvent::Impl::> gets prepended and the
1760	and the resulting module name is loaded and if the load was successful,	2178	resulting module name is loaded and - if the load was successful - used as
1761	used as event model. If it fails to load AnyEvent will proceed with	2179	event model backend. If it fails to load then AnyEvent will proceed with
1762	auto detection and -probing.	2180	auto detection and -probing.
1763		2181
1764	This functionality might change in future versions.	2182	If the string ends with C<::> instead (e.g. C<AnyEvent::Impl::EV::>) then
		2183	nothing gets prepended and the module name is used as-is (hint: C<::> at
		2184	the end of a string designates a module name and quotes it appropriately).
1765		2185
1766	For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you	2186	For example, to force the pure perl model (L<AnyEvent::Loop::Perl>) you
1767	could start your program like this:	2187	could start your program like this:
1768		2188
1769	PERL_ANYEVENT_MODEL=Perl perl ...	2189	PERL_ANYEVENT_MODEL=Perl perl ...
		2190
		2191	=item C<PERL_ANYEVENT_IO_MODEL>
		2192
		2193	The current file I/O model - see L<AnyEvent::IO> for more info.
		2194
		2195	At the moment, only C<Perl> (small, pure-perl, synchronous) and
		2196	C<IOAIO> (truly asynchronous) are supported. The default is C<IOAIO> if
		2197	L<AnyEvent::AIO> can be loaded, otherwise it is C<Perl>.
1770		2198
1771	=item C<PERL_ANYEVENT_PROTOCOLS>	2199	=item C<PERL_ANYEVENT_PROTOCOLS>
1772		2200
1773	Used by both L<AnyEvent::DNS> and L<AnyEvent::Socket> to determine preferences	2201	Used by both L<AnyEvent::DNS> and L<AnyEvent::Socket> to determine preferences
1774	for IPv4 or IPv6. The default is unspecified (and might change, or be the result	2202	for IPv4 or IPv6. The default is unspecified (and might change, or be the result
…		…
1787	but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4>	2215	but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4>
1788	- only support IPv4, never try to resolve or contact IPv6	2216	- only support IPv4, never try to resolve or contact IPv6
1789	addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or	2217	addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or
1790	IPv6, but prefer IPv6 over IPv4.	2218	IPv6, but prefer IPv6 over IPv4.
1791		2219
		2220	=item C<PERL_ANYEVENT_HOSTS>
		2221
		2222	This variable, if specified, overrides the F</etc/hosts> file used by
		2223	L<AnyEvent::Socket>C<::resolve_sockaddr>, i.e. hosts aliases will be read
		2224	from that file instead.
		2225
1792	=item C<PERL_ANYEVENT_EDNS0>	2226	=item C<PERL_ANYEVENT_EDNS0>
1793		2227
1794	Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension	2228	Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension for
1795	for DNS. This extension is generally useful to reduce DNS traffic, but	2229	DNS. This extension is generally useful to reduce DNS traffic, especially
1796	some (broken) firewalls drop such DNS packets, which is why it is off by	2230	when DNSSEC is involved, but some (broken) firewalls drop such DNS
1797	default.	2231	packets, which is why it is off by default.
1798		2232
1799	Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce	2233	Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce
1800	EDNS0 in its DNS requests.	2234	EDNS0 in its DNS requests.
1801		2235
1802	=item C<PERL_ANYEVENT_MAX_FORKS>	2236	=item C<PERL_ANYEVENT_MAX_FORKS>
…		…
1808		2242
1809	The default value for the C<max_outstanding> parameter for the default DNS	2243	The default value for the C<max_outstanding> parameter for the default DNS
1810	resolver - this is the maximum number of parallel DNS requests that are	2244	resolver - this is the maximum number of parallel DNS requests that are
1811	sent to the DNS server.	2245	sent to the DNS server.
1812		2246
		2247	=item C<PERL_ANYEVENT_MAX_SIGNAL_LATENCY>
		2248
		2249	Perl has inherently racy signal handling (you can basically choose between
		2250	losing signals and memory corruption) - pure perl event loops (including
		2251	C<AnyEvent::Loop>, when C<Async::Interrupt> isn't available) therefore
		2252	have to poll regularly to avoid losing signals.
		2253
		2254	Some event loops are racy, but don't poll regularly, and some event loops
		2255	are written in C but are still racy. For those event loops, AnyEvent
		2256	installs a timer that regularly wakes up the event loop.
		2257
		2258	By default, the interval for this timer is C<10> seconds, but you can
		2259	override this delay with this environment variable (or by setting
		2260	the C<$AnyEvent::MAX_SIGNAL_LATENCY> variable before creating signal
		2261	watchers).
		2262
		2263	Lower values increase CPU (and energy) usage, higher values can introduce
		2264	long delays when reaping children or waiting for signals.
		2265
		2266	The L<AnyEvent::Async> module, if available, will be used to avoid this
		2267	polling (with most event loops).
		2268
1813	=item C<PERL_ANYEVENT_RESOLV_CONF>	2269	=item C<PERL_ANYEVENT_RESOLV_CONF>
1814		2270
1815	The file to use instead of F</etc/resolv.conf> (or OS-specific	2271	The absolute path to a F<resolv.conf>-style file to use instead of
1816	configuration) in the default resolver. When set to the empty string, no	2272	F</etc/resolv.conf> (or the OS-specific configuration) in the default
1817	default config will be used.	2273	resolver, or the empty string to select the default configuration.
1818		2274
1819	=item C<PERL_ANYEVENT_CA_FILE>, C<PERL_ANYEVENT_CA_PATH>.	2275	=item C<PERL_ANYEVENT_CA_FILE>, C<PERL_ANYEVENT_CA_PATH>.
1820		2276
1821	When neither C<ca_file> nor C<ca_path> was specified during	2277	When neither C<ca_file> nor C<ca_path> was specified during
1822	L<AnyEvent::TLS> context creation, and either of these environment	2278	L<AnyEvent::TLS> context creation, and either of these environment
1823	variables exist, they will be used to specify CA certificate locations	2279	variables are nonempty, they will be used to specify CA certificate
1824	instead of a system-dependent default.	2280	locations instead of a system-dependent default.
1825		2281
1826	=item C<PERL_ANYEVENT_AVOID_GUARD> and C<PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT>	2282	=item C<PERL_ANYEVENT_AVOID_GUARD> and C<PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT>
1827		2283
1828	When these are set to C<1>, then the respective modules are not	2284	When these are set to C<1>, then the respective modules are not
1829	loaded. Mostly good for testing AnyEvent itself.	2285	loaded. Mostly good for testing AnyEvent itself.
…		…
1892	warn "read: $input\n"; # output what has been read	2348	warn "read: $input\n"; # output what has been read
1893	$cv->send if $input =~ /^q/i; # quit program if /^q/i	2349	$cv->send if $input =~ /^q/i; # quit program if /^q/i
1894	},	2350	},
1895	);	2351	);
1896		2352
1897	my $time_watcher; # can only be used once
1898
1899	sub new_timer {
1900	$timer = AnyEvent->timer (after => 1, cb => sub {	2353	my $time_watcher = AnyEvent->timer (after => 1, interval => 1, cb => sub {
1901	warn "timeout\n"; # print 'timeout' about every second	2354	warn "timeout\n"; # print 'timeout' at most every second
1902	&new_timer; # and restart the time
1903	});	2355	});
1904	}
1905
1906	new_timer; # create first timer
1907		2356
1908	$cv->recv; # wait until user enters /^q/i	2357	$cv->recv; # wait until user enters /^q/i
1909		2358
1910	=head1 REAL-WORLD EXAMPLE	2359	=head1 REAL-WORLD EXAMPLE
1911		2360
…		…
1984		2433
1985	The actual code goes further and collects all errors (C<die>s, exceptions)	2434	The actual code goes further and collects all errors (C<die>s, exceptions)
1986	that occurred during request processing. The C<result> method detects	2435	that occurred during request processing. The C<result> method detects
1987	whether an exception as thrown (it is stored inside the $txn object)	2436	whether an exception as thrown (it is stored inside the $txn object)
1988	and just throws the exception, which means connection errors and other	2437	and just throws the exception, which means connection errors and other
1989	problems get reported tot he code that tries to use the result, not in a	2438	problems get reported to the code that tries to use the result, not in a
1990	random callback.	2439	random callback.
1991		2440
1992	All of this enables the following usage styles:	2441	All of this enables the following usage styles:
1993		2442
1994	1. Blocking:	2443	1. Blocking:
…		…
2042	through AnyEvent. The benchmark creates a lot of timers (with a zero	2491	through AnyEvent. The benchmark creates a lot of timers (with a zero
2043	timeout) and I/O watchers (watching STDOUT, a pty, to become writable,	2492	timeout) and I/O watchers (watching STDOUT, a pty, to become writable,
2044	which it is), lets them fire exactly once and destroys them again.	2493	which it is), lets them fire exactly once and destroys them again.
2045		2494
2046	Source code for this benchmark is found as F<eg/bench> in the AnyEvent	2495	Source code for this benchmark is found as F<eg/bench> in the AnyEvent
2047	distribution.	2496	distribution. It uses the L<AE> interface, which makes a real difference
		2497	for the EV and Perl backends only.
2048		2498
2049	=head3 Explanation of the columns	2499	=head3 Explanation of the columns
2050		2500
2051	I<watcher> is the number of event watchers created/destroyed. Since	2501	I<watcher> is the number of event watchers created/destroyed. Since
2052	different event models feature vastly different performances, each event	2502	different event models feature vastly different performances, each event
…		…
2073	watcher.	2523	watcher.
2074		2524
2075	=head3 Results	2525	=head3 Results
2076		2526
2077	name watchers bytes create invoke destroy comment	2527	name watchers bytes create invoke destroy comment
2078	EV/EV 400000 224 0.47 0.35 0.27 EV native interface	2528	EV/EV 100000 223 0.47 0.43 0.27 EV native interface
2079	EV/Any 100000 224 2.88 0.34 0.27 EV + AnyEvent watchers	2529	EV/Any 100000 223 0.48 0.42 0.26 EV + AnyEvent watchers
2080	CoroEV/Any 100000 224 2.85 0.35 0.28 coroutines + Coro::Signal	2530	Coro::EV/Any 100000 223 0.47 0.42 0.26 coroutines + Coro::Signal
2081	Perl/Any 100000 452 4.13 0.73 0.95 pure perl implementation	2531	Perl/Any 100000 431 2.70 0.74 0.92 pure perl implementation
2082	Event/Event 16000 517 32.20 31.80 0.81 Event native interface	2532	Event/Event 16000 516 31.16 31.84 0.82 Event native interface
2083	Event/Any 16000 590 35.85 31.55 1.06 Event + AnyEvent watchers	2533	Event/Any 16000 1203 42.61 34.79 1.80 Event + AnyEvent watchers
2084	IOAsync/Any 16000 989 38.10 32.77 11.13 via IO::Async::Loop::IO_Poll	2534	IOAsync/Any 16000 1911 41.92 27.45 16.81 via IO::Async::Loop::IO_Poll
2085	IOAsync/Any 16000 990 37.59 29.50 10.61 via IO::Async::Loop::Epoll	2535	IOAsync/Any 16000 1726 40.69 26.37 15.25 via IO::Async::Loop::Epoll
2086	Glib/Any 16000 1357 102.33 12.31 51.00 quadratic behaviour	2536	Glib/Any 16000 1118 89.00 12.57 51.17 quadratic behaviour
2087	Tk/Any 2000 1860 27.20 66.31 14.00 SEGV with >> 2000 watchers	2537	Tk/Any 2000 1346 20.96 10.75 8.00 SEGV with >> 2000 watchers
2088	POE/Event 2000 6328 109.99 751.67 14.02 via POE::Loop::Event	2538	POE/Any 2000 6951 108.97 795.32 14.24 via POE::Loop::Event
2089	POE/Select 2000 6027 94.54 809.13 579.80 via POE::Loop::Select	2539	POE/Any 2000 6648 94.79 774.40 575.51 via POE::Loop::Select
2090		2540
2091	=head3 Discussion	2541	=head3 Discussion
2092		2542
2093	The benchmark does I<not> measure scalability of the event loop very	2543	The benchmark does I<not> measure scalability of the event loop very
2094	well. For example, a select-based event loop (such as the pure perl one)	2544	well. For example, a select-based event loop (such as the pure perl one)
…		…
2106	benchmark machine, handling an event takes roughly 1600 CPU cycles with	2556	benchmark machine, handling an event takes roughly 1600 CPU cycles with
2107	EV, 3100 CPU cycles with AnyEvent's pure perl loop and almost 3000000 CPU	2557	EV, 3100 CPU cycles with AnyEvent's pure perl loop and almost 3000000 CPU
2108	cycles with POE.	2558	cycles with POE.
2109		2559
2110	C<EV> is the sole leader regarding speed and memory use, which are both	2560	C<EV> is the sole leader regarding speed and memory use, which are both
2111	maximal/minimal, respectively. Even when going through AnyEvent, it uses	2561	maximal/minimal, respectively. When using the L<AE> API there is zero
		2562	overhead (when going through the AnyEvent API create is about 5-6 times
		2563	slower, with other times being equal, so still uses far less memory than
2112	far less memory than any other event loop and is still faster than Event	2564	any other event loop and is still faster than Event natively).
2113	natively.
2114		2565
2115	The pure perl implementation is hit in a few sweet spots (both the	2566	The pure perl implementation is hit in a few sweet spots (both the
2116	constant timeout and the use of a single fd hit optimisations in the perl	2567	constant timeout and the use of a single fd hit optimisations in the perl
2117	interpreter and the backend itself). Nevertheless this shows that it	2568	interpreter and the backend itself). Nevertheless this shows that it
2118	adds very little overhead in itself. Like any select-based backend its	2569	adds very little overhead in itself. Like any select-based backend its
…		…
2166	(even when used without AnyEvent), but most event loops have acceptable	2617	(even when used without AnyEvent), but most event loops have acceptable
2167	performance with or without AnyEvent.	2618	performance with or without AnyEvent.
2168		2619
2169	=item * The overhead AnyEvent adds is usually much smaller than the overhead of	2620	=item * The overhead AnyEvent adds is usually much smaller than the overhead of
2170	the actual event loop, only with extremely fast event loops such as EV	2621	the actual event loop, only with extremely fast event loops such as EV
2171	adds AnyEvent significant overhead.	2622	does AnyEvent add significant overhead.
2172		2623
2173	=item * You should avoid POE like the plague if you want performance or	2624	=item * You should avoid POE like the plague if you want performance or
2174	reasonable memory usage.	2625	reasonable memory usage.
2175		2626
2176	=back	2627	=back
…		…
2192	In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100	2643	In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100
2193	(1%) are active. This mirrors the activity of large servers with many	2644	(1%) are active. This mirrors the activity of large servers with many
2194	connections, most of which are idle at any one point in time.	2645	connections, most of which are idle at any one point in time.
2195		2646
2196	Source code for this benchmark is found as F<eg/bench2> in the AnyEvent	2647	Source code for this benchmark is found as F<eg/bench2> in the AnyEvent
2197	distribution.	2648	distribution. It uses the L<AE> interface, which makes a real difference
		2649	for the EV and Perl backends only.
2198		2650
2199	=head3 Explanation of the columns	2651	=head3 Explanation of the columns
2200		2652
2201	I<sockets> is the number of sockets, and twice the number of "servers" (as	2653	I<sockets> is the number of sockets, and twice the number of "servers" (as
2202	each server has a read and write socket end).	2654	each server has a read and write socket end).
…		…
2210	a new one that moves the timeout into the future.	2662	a new one that moves the timeout into the future.
2211		2663
2212	=head3 Results	2664	=head3 Results
2213		2665
2214	name sockets create request	2666	name sockets create request
2215	EV 20000 69.01 11.16	2667	EV 20000 62.66 7.99
2216	Perl 20000 73.32 35.87	2668	Perl 20000 68.32 32.64
2217	IOAsync 20000 157.00 98.14 epoll	2669	IOAsync 20000 174.06 101.15 epoll
2218	IOAsync 20000 159.31 616.06 poll	2670	IOAsync 20000 174.67 610.84 poll
2219	Event 20000 212.62 257.32	2671	Event 20000 202.69 242.91
2220	Glib 20000 651.16 1896.30	2672	Glib 20000 557.01 1689.52
2221	POE 20000 349.67 12317.24 uses POE::Loop::Event	2673	POE 20000 341.54 12086.32 uses POE::Loop::Event
2222		2674
2223	=head3 Discussion	2675	=head3 Discussion
2224		2676
2225	This benchmark I<does> measure scalability and overall performance of the	2677	This benchmark I<does> measure scalability and overall performance of the
2226	particular event loop.	2678	particular event loop.
…		…
2352	As you can see, the AnyEvent + EV combination even beats the	2804	As you can see, the AnyEvent + EV combination even beats the
2353	hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl	2805	hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl
2354	backend easily beats IO::Lambda and POE.	2806	backend easily beats IO::Lambda and POE.
2355		2807
2356	And even the 100% non-blocking version written using the high-level (and	2808	And even the 100% non-blocking version written using the high-level (and
2357	slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda by a	2809	slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda
2358	large margin, even though it does all of DNS, tcp-connect and socket I/O	2810	higher level ("unoptimised") abstractions by a large margin, even though
2359	in a non-blocking way.	2811	it does all of DNS, tcp-connect and socket I/O in a non-blocking way.
2360		2812
2361	The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and	2813	The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and
2362	F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are	2814	F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are
2363	part of the IO::lambda distribution and were used without any changes.	2815	part of the IO::Lambda distribution and were used without any changes.
2364		2816
2365		2817
2366	=head1 SIGNALS	2818	=head1 SIGNALS
2367		2819
2368	AnyEvent currently installs handlers for these signals:	2820	AnyEvent currently installs handlers for these signals:
…		…
2405	unless defined $SIG{PIPE};	2857	unless defined $SIG{PIPE};
2406		2858
2407	=head1 RECOMMENDED/OPTIONAL MODULES	2859	=head1 RECOMMENDED/OPTIONAL MODULES
2408		2860
2409	One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and	2861	One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and
2410	it's built-in modules) are required to use it.	2862	its built-in modules) are required to use it.
2411		2863
2412	That does not mean that AnyEvent won't take advantage of some additional	2864	That does not mean that AnyEvent won't take advantage of some additional
2413	modules if they are installed.	2865	modules if they are installed.
2414		2866
2415	This section epxlains which additional modules will be used, and how they	2867	This section explains which additional modules will be used, and how they
2416	affect AnyEvent's operetion.	2868	affect AnyEvent's operation.
2417		2869
2418	=over 4	2870	=over 4
2419		2871
2420	=item L<Async::Interrupt>	2872	=item L<Async::Interrupt>
2421		2873
…		…
2426	catch the signals) with some delay (default is 10 seconds, look for	2878	catch the signals) with some delay (default is 10 seconds, look for
2427	C<$AnyEvent::MAX_SIGNAL_LATENCY>).	2879	C<$AnyEvent::MAX_SIGNAL_LATENCY>).
2428		2880
2429	If this module is available, then it will be used to implement signal	2881	If this module is available, then it will be used to implement signal
2430	catching, which means that signals will not be delayed, and the event loop	2882	catching, which means that signals will not be delayed, and the event loop
2431	will not be interrupted regularly, which is more efficient (And good for	2883	will not be interrupted regularly, which is more efficient (and good for
2432	battery life on laptops).	2884	battery life on laptops).
2433		2885
2434	This affects not just the pure-perl event loop, but also other event loops	2886	This affects not just the pure-perl event loop, but also other event loops
2435	that have no signal handling on their own (e.g. Glib, Tk, Qt).	2887	that have no signal handling on their own (e.g. Glib, Tk, Qt).
2436		2888
…		…
2448	automatic timer adjustments even when no monotonic clock is available,	2900	automatic timer adjustments even when no monotonic clock is available,
2449	can take avdantage of advanced kernel interfaces such as C<epoll> and	2901	can take avdantage of advanced kernel interfaces such as C<epoll> and
2450	C<kqueue>, and is the fastest backend I<by far>. You can even embed	2902	C<kqueue>, and is the fastest backend I<by far>. You can even embed
2451	L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>).	2903	L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>).
2452		2904
		2905	If you only use backends that rely on another event loop (e.g. C<Tk>),
		2906	then this module will do nothing for you.
		2907
2453	=item L<Guard>	2908	=item L<Guard>
2454		2909
2455	The guard module, when used, will be used to implement	2910	The guard module, when used, will be used to implement
2456	C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a	2911	C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a
2457	lot less memory), but otherwise doesn't affect guard operation much. It is	2912	lot less memory), but otherwise doesn't affect guard operation much. It is
2458	purely used for performance.	2913	purely used for performance.
2459		2914
2460	=item L<JSON> and L<JSON::XS>	2915	=item L<JSON> and L<JSON::XS>
2461		2916
2462	This module is required when you want to read or write JSON data via	2917	One of these modules is required when you want to read or write JSON data
2463	L<AnyEvent::Handle>. It is also written in pure-perl, but can take	2918	via L<AnyEvent::Handle>. L<JSON> is also written in pure-perl, but can take
2464	advantage of the ultra-high-speed L<JSON::XS> module when it is installed.	2919	advantage of the ultra-high-speed L<JSON::XS> module when it is installed.
2465
2466	In fact, L<AnyEvent::Handle> will use L<JSON::XS> by default if it is
2467	installed.
2468		2920
2469	=item L<Net::SSLeay>	2921	=item L<Net::SSLeay>
2470		2922
2471	Implementing TLS/SSL in Perl is certainly interesting, but not very	2923	Implementing TLS/SSL in Perl is certainly interesting, but not very
2472	worthwhile: If this module is installed, then L<AnyEvent::Handle> (with	2924	worthwhile: If this module is installed, then L<AnyEvent::Handle> (with
2473	the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL.	2925	the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL.
2474		2926
2475	=item L<Time::HiRes>	2927	=item L<Time::HiRes>
2476		2928
2477	This module is part of perl since release 5.008. It will be used when the	2929	This module is part of perl since release 5.008. It will be used when the
2478	chosen event library does not come with a timing source on it's own. The	2930	chosen event library does not come with a timing source of its own. The
2479	pure-perl event loop (L<AnyEvent::Impl::Perl>) will additionally use it to	2931	pure-perl event loop (L<AnyEvent::Loop>) will additionally load it to
2480	try to use a monotonic clock for timing stability.	2932	try to use a monotonic clock for timing stability.
2481		2933
		2934	=item L<AnyEvent::AIO> (and L<IO::AIO>)
		2935
		2936	The default implementation of L<AnyEvent::IO> is to do I/O synchronously,
		2937	stopping programs while they access the disk, which is fine for a lot of
		2938	programs.
		2939
		2940	Installing AnyEvent::AIO (and its IO::AIO dependency) makes it switch to
		2941	a true asynchronous implementation, so event processing can continue even
		2942	while waiting for disk I/O.
		2943
2482	=back	2944	=back
2483		2945
2484		2946
2485	=head1 FORK	2947	=head1 FORK
2486		2948
2487	Most event libraries are not fork-safe. The ones who are usually are	2949	Most event libraries are not fork-safe. The ones who are usually are
2488	because they rely on inefficient but fork-safe C<select> or C<poll>	2950	because they rely on inefficient but fork-safe C<select> or C<poll> calls
2489	calls. Only L<EV> is fully fork-aware.	2951	- higher performance APIs such as BSD's kqueue or the dreaded Linux epoll
		2952	are usually badly thought-out hacks that are incompatible with fork in
		2953	one way or another. Only L<EV> is fully fork-aware and ensures that you
		2954	continue event-processing in both parent and child (or both, if you know
		2955	what you are doing).
		2956
		2957	This means that, in general, you cannot fork and do event processing in
		2958	the child if the event library was initialised before the fork (which
		2959	usually happens when the first AnyEvent watcher is created, or the library
		2960	is loaded).
2490		2961
2491	If you have to fork, you must either do so I<before> creating your first	2962	If you have to fork, you must either do so I<before> creating your first
2492	watcher OR you must not use AnyEvent at all in the child OR you must do	2963	watcher OR you must not use AnyEvent at all in the child OR you must do
2493	something completely out of the scope of AnyEvent.	2964	something completely out of the scope of AnyEvent.
		2965
		2966	The problem of doing event processing in the parent I<and> the child
		2967	is much more complicated: even for backends that I<are> fork-aware or
		2968	fork-safe, their behaviour is not usually what you want: fork clones all
		2969	watchers, that means all timers, I/O watchers etc. are active in both
		2970	parent and child, which is almost never what you want. USing C<exec>
		2971	to start worker children from some kind of manage rprocess is usually
		2972	preferred, because it is much easier and cleaner, at the expense of having
		2973	to have another binary.
2494		2974
2495		2975
2496	=head1 SECURITY CONSIDERATIONS	2976	=head1 SECURITY CONSIDERATIONS
2497		2977
2498	AnyEvent can be forced to load any event model via	2978	AnyEvent can be forced to load any event model via
…		…
2528	pronounced).	3008	pronounced).
2529		3009
2530		3010
2531	=head1 SEE ALSO	3011	=head1 SEE ALSO
2532		3012
2533	Utility functions: L<AnyEvent::Util>.	3013	Tutorial/Introduction: L<AnyEvent::Intro>.
2534		3014
2535	Event modules: L<EV>, L<EV::Glib>, L<Glib::EV>, L<Event>, L<Glib::Event>,	3015	FAQ: L<AnyEvent::FAQ>.
2536	L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.	3016
		3017	Utility functions: L<AnyEvent::Util> (misc. grab-bag), L<AnyEvent::Log>
		3018	(simply logging).
		3019
		3020	Development/Debugging: L<AnyEvent::Strict> (stricter checking),
		3021	L<AnyEvent::Debug> (interactive shell, watcher tracing).
		3022
		3023	Supported event modules: L<AnyEvent::Loop>, L<EV>, L<EV::Glib>,
		3024	L<Glib::EV>, L<Event>, L<Glib::Event>, L<Glib>, L<Tk>, L<Event::Lib>,
		3025	L<Qt>, L<POE>, L<FLTK>.
2537		3026
2538	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,	3027	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,
2539	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,	3028	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,
2540	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,	3029	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,
2541	L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>, L<Anyevent::Impl::Irssi>.	3030	L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>, L<Anyevent::Impl::Irssi>,
		3031	L<AnyEvent::Impl::FLTK>.
2542		3032
2543	Non-blocking file handles, sockets, TCP clients and	3033	Non-blocking handles, pipes, stream sockets, TCP clients and
2544	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.	3034	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.
2545		3035
		3036	Asynchronous File I/O: L<AnyEvent::IO>.
		3037
2546	Asynchronous DNS: L<AnyEvent::DNS>.	3038	Asynchronous DNS: L<AnyEvent::DNS>.
2547		3039
2548	Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>,	3040	Thread support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>.
2549	L<Coro::Event>,
2550		3041
2551	Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::XMPP>,	3042	Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::IRC>,
2552	L<AnyEvent::HTTP>.	3043	L<AnyEvent::HTTP>.
2553		3044
2554		3045
2555	=head1 AUTHOR	3046	=head1 AUTHOR
2556		3047
2557	Marc Lehmann <schmorp@schmorp.de>	3048	Marc Lehmann <schmorp@schmorp.de>
2558	http://home.schmorp.de/	3049	http://anyevent.schmorp.de
2559		3050
2560	=cut	3051	=cut
2561		3052
2562	1	3053	1
2563		3054

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