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Revision 1.396 by root, Sat Mar 10 17:36:24 2012 UTC

1	=head1 NAME	1	=head1 NAME
2		2
3	AnyEvent - the DBI of event loop programming	3	AnyEvent - the DBI of event loop programming
4		4
5	EV, Event, Glib, Tk, Perl, Event::Lib, Irssi, rxvt-unicode, IO::Async, Qt	5	EV, Event, Glib, Tk, Perl, Event::Lib, Irssi, rxvt-unicode, IO::Async, Qt,
6	and POE are various supported event loops/environments.	6	FLTK and POE are various supported event loops/environments.
7		7
8	=head1 SYNOPSIS	8	=head1 SYNOPSIS
9		9
10	use AnyEvent;	10	use AnyEvent;
11		11
…		…
15	# file handle or descriptor readable	15	# file handle or descriptor readable
16	my $w = AnyEvent->io (fh => $fh, poll => "r", cb => sub { ... });	16	my $w = AnyEvent->io (fh => $fh, poll => "r", cb => sub { ... });
17		17
18	# one-shot or repeating timers	18	# one-shot or repeating timers
19	my $w = AnyEvent->timer (after => $seconds, cb => sub { ... });	19	my $w = AnyEvent->timer (after => $seconds, cb => sub { ... });
20	my $w = AnyEvent->timer (after => $seconds, interval => $seconds, cb => ...	20	my $w = AnyEvent->timer (after => $seconds, interval => $seconds, cb => ...);
21		21
22	print AnyEvent->now; # prints current event loop time	22	print AnyEvent->now; # prints current event loop time
23	print AnyEvent->time; # think Time::HiRes::time or simply CORE::time.	23	print AnyEvent->time; # think Time::HiRes::time or simply CORE::time.
24		24
25	# POSIX signal	25	# POSIX signal
…		…
46	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
47	L<AnyEvent::Intro> manpage.	47	L<AnyEvent::Intro> manpage.
48		48
49	=head1 SUPPORT	49	=head1 SUPPORT
50		50
		51	An FAQ document is available as L<AnyEvent::FAQ>.
		52
51	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
52	channel, too.	54	channel, too.
53		55
54	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
55	Repository>, at L<http://anyevent.schmorp.de>, for more info.	57	Repository>, at L<http://anyevent.schmorp.de>, for more info.
56		58
…		…
76	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
77	model you use.	79	model you use.
78		80
79	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
80	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
81	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
82	cannot use anything else, as they are simply incompatible to everything	84	cannot use anything else, as they are simply incompatible to everything
83	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
84	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.
85		87
86	AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works	88	AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works
87	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
88	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
89	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
90	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
91	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
92	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,
93	to AnyEvent, too, so it is future-proof).	95	so it is future-proof).
94		96
95	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
96	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
97	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
98	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
99	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
100	technically possible.	102	technically possible.
101		103
102	Of course, AnyEvent comes with a big (and fully optional!) toolbox	104	Of course, AnyEvent comes with a big (and fully optional!) toolbox
103	of useful functionality, such as an asynchronous DNS resolver, 100%	105	of useful functionality, such as an asynchronous DNS resolver, 100%
…		…
109	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
110	model, you should I<not> use this module.	112	model, you should I<not> use this module.
111		113
112	=head1 DESCRIPTION	114	=head1 DESCRIPTION
113		115
114	L<AnyEvent> provides an identical interface to multiple event loops. This	116	L<AnyEvent> provides a uniform interface to various event loops. This
115	allows module authors to utilise an event loop without forcing module	117	allows module authors to use event loop functionality without forcing
116	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
117	peacefully at any one time).	119	than one event loop cannot coexist peacefully).
118		120
119	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>
120	module.	122	module.
121		123
122	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
123	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
124	following modules is already loaded: L<EV>,	126	following modules is already loaded: L<EV>, L<AnyEvent::Loop>,
125	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
126	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
127	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
128	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
129	be successfully loaded will be used. If, after this, still none could be	131	the other two are not normally tried.
130	found, AnyEvent will fall back to a pure-perl event loop, which is not
131	very efficient, but should work everywhere.
132		132
133	Because AnyEvent first checks for modules that are already loaded, loading	133	Because AnyEvent first checks for modules that are already loaded, loading
134	an event model explicitly before first using AnyEvent will likely make	134	an event model explicitly before first using AnyEvent will likely make
135	that model the default. For example:	135	that model the default. For example:
136		136
…		…
142	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
143	starts using it, all bets are off - this case should be very rare though,	143	starts using it, all bets are off - this case should be very rare though,
144	as very few modules hardcode event loops without announcing this very	144	as very few modules hardcode event loops without announcing this very
145	loudly.	145	loudly.
146		146
147	The pure-perl implementation of AnyEvent is called	147	The pure-perl implementation of AnyEvent is called C<AnyEvent::Loop>. Like
148	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
149	explicitly and enjoy the high availability of that event loop :)	149	availability of that event loop :)
150		150
151	=head1 WATCHERS	151	=head1 WATCHERS
152		152
153	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
154	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
…		…
159	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
160	is in control).	160	is in control).
161		161
162	Note that B<callbacks must not permanently change global variables>	162	Note that B<callbacks must not permanently change global variables>
163	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<<
164	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
165	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
166	widely between event loops.	166	widely between event loops.
167		167
168	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
169	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
170	to it).	170	to it).
171		171
172	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.
173		173
174	Many watchers either are used with "recursion" (repeating timers for	174	Many watchers either are used with "recursion" (repeating timers for
175	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.
176		176
177	An any way to achieve that is this pattern:	177	One way to achieve that is this pattern:
178		178
179	my $w; $w = AnyEvent->type (arg => value ..., cb => sub {	179	my $w; $w = AnyEvent->type (arg => value ..., cb => sub {
180	# you can use $w here, for example to undef it	180	# you can use $w here, for example to undef it
181	undef $w;	181	undef $w;
182	});	182	});
…		…
214		214
215	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.
216	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
217	underlying file descriptor.	217	underlying file descriptor.
218		218
219	Some event loops issue spurious readyness notifications, so you should	219	Some event loops issue spurious readiness notifications, so you should
220	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
221	handles.	221	handles.
222		222
223	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
224	watcher.	224	watcher.
…		…
248		248
249	Although the callback might get passed parameters, their value and	249	Although the callback might get passed parameters, their value and
250	presence is undefined and you cannot rely on them. Portable AnyEvent	250	presence is undefined and you cannot rely on them. Portable AnyEvent
251	callbacks cannot use arguments passed to time watcher callbacks.	251	callbacks cannot use arguments passed to time watcher callbacks.
252		252
253	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
254	parameter, C<interval>, as a strictly positive number (> 0), then the	254	parameter, C<interval>, as a strictly positive number (> 0), then the
255	callback will be invoked regularly at that interval (in fractional	255	callback will be invoked regularly at that interval (in fractional
256	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
257	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.
258		258
259	The callback will be rescheduled before invoking the callback, but no	259	The callback will be rescheduled before invoking the callback, but no
260	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
261	only approximate.	261	only approximate.
262		262
263	Example: fire an event after 7.7 seconds.	263	Example: fire an event after 7.7 seconds.
264		264
265	my $w = AnyEvent->timer (after => 7.7, cb => sub {	265	my $w = AnyEvent->timer (after => 7.7, cb => sub {
…		…
283		283
284	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
285	use absolute time internally. This makes a difference when your clock	285	use absolute time internally. This makes a difference when your clock
286	"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
287	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
288	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.
289		289
290	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
291	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
292	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)
293	timers.	293	timers.
294		294
295	AnyEvent always prefers relative timers, if available, matching the	295	AnyEvent always prefers relative timers, if available, matching the
296	AnyEvent API.	296	AnyEvent API.
…		…
318	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
319	function to call when you want to know the current time.>	319	function to call when you want to know the current time.>
320		320
321	This function is also often faster then C<< AnyEvent->time >>, and	321	This function is also often faster then C<< AnyEvent->time >>, and
322	thus the preferred method if you want some timestamp (for example,	322	thus the preferred method if you want some timestamp (for example,
323	L<AnyEvent::Handle> uses this to update it's activity timeouts).	323	L<AnyEvent::Handle> uses this to update its activity timeouts).
324		324
325	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
326	with your timing, you can skip it without bad conscience.	326	with your timing; you can skip it without a bad conscience.
327		327
328	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>
329	and L<EV> and the following set-up:	329	and L<EV> and the following set-up:
330		330
331	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
332	time=500 (assume no other callbacks delay processing). In your callback,	332	time=500 (assume no other callbacks delay processing). In your callback,
333	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
334	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
335	after three seconds.	335	after three seconds.
336		336
…		…
356	difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into	356	difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into
357	account.	357	account.
358		358
359	=item AnyEvent->now_update	359	=item AnyEvent->now_update
360		360
361	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
362	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 >>,
363	AnyEvent->now >>, above).	363	above).
364		364
365	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
366	this "current" time will differ substantially from the real time, which	366	this "current" time will differ substantially from the real time, which
367	might affect timers and time-outs.	367	might affect timers and time-outs.
368		368
…		…
415	not restart syscalls (that includes L<Async::Interrupt> and AnyEvent's	415	not restart syscalls (that includes L<Async::Interrupt> and AnyEvent's
416	pure perl implementation).	416	pure perl implementation).
417		417
418	=head3 Safe/Unsafe Signals	418	=head3 Safe/Unsafe Signals
419		419
420	Perl signals can be either "safe" (synchronous to opcode handling) or	420	Perl signals can be either "safe" (synchronous to opcode handling)
421	"unsafe" (asynchronous) - the former might get delayed indefinitely, the	421	or "unsafe" (asynchronous) - the former might delay signal delivery
422	latter might corrupt your memory.	422	indefinitely, the latter might corrupt your memory.
423		423
424	AnyEvent signal handlers are, in addition, synchronous to the event loop,	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	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.	426	called as part of the normal event handling (just like timer, I/O etc.
427	callbacks, too).	427	callbacks, too).
428		428
429	=head3 Signal Races, Delays and Workarounds	429	=head3 Signal Races, Delays and Workarounds
430		430
431	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
432	callbacks to signals in a generic way, which is a pity, as you cannot	432	attaching callbacks to signals in a generic way, which is a pity,
433	do race-free signal handling in perl, requiring C libraries for	433	as you cannot do race-free signal handling in perl, requiring
434	this. AnyEvent will try to do it's best, which means in some cases,	434	C libraries for this. AnyEvent will try to do its best, which
435	signals will be delayed. The maximum time a signal might be delayed is	435	means in some cases, signals will be delayed. The maximum time
436	specified in C<$AnyEvent::MAX_SIGNAL_LATENCY> (default: 10 seconds). This	436	a signal might be delayed is 10 seconds by default, but can
437	variable can be changed only before the first signal watcher is created,	437	be overriden via C<$ENV{PERL_ANYEVENT_MAX_SIGNAL_LATENCY}> or
438	and should be left alone otherwise. This variable determines how often	438	C<$AnyEvent::MAX_SIGNAL_LATENCY> - see the L<ENVIRONMENT VARIABLES>
439	AnyEvent polls for signals (in case a wake-up was missed). Higher values	439	section for details.
440	will cause fewer spurious wake-ups, which is better for power and CPU
441	saving.
442		440
443	All these problems can be avoided by installing the optional	441	All these problems can be avoided by installing the optional
444	L<Async::Interrupt> module, which works with most event loops. It will not	442	L<Async::Interrupt> module, which works with most event loops. It will not
445	work with inherently broken event loops such as L<Event> or L<Event::Lib>	443	work with inherently broken event loops such as L<Event> or L<Event::Lib>
446	(and not with L<POE> currently, as POE does it's own workaround with	444	(and not with L<POE> currently). For those, you just have to suffer the
447	one-second latency). For those, you just have to suffer the delays.	445	delays.
448		446
449	=head2 CHILD PROCESS WATCHERS	447	=head2 CHILD PROCESS WATCHERS
450		448
451	$w = AnyEvent->child (pid => <process id>, cb => <callback>);	449	$w = AnyEvent->child (pid => <process id>, cb => <callback>);
452		450
453	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.
454		452
455	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,
456	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
457	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
458	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
459	(stopped/continued).	457	(stopped/continued).
460		458
…		…
482	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
483	watcher before you C<fork> the child (alternatively, you can call	481	watcher before you C<fork> the child (alternatively, you can call
484	C<AnyEvent::detect>).	482	C<AnyEvent::detect>).
485		483
486	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
487	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
488	mentioned in the description of signal watchers apply.	486	problems mentioned in the description of signal watchers apply.
489		487
490	Example: fork a process and wait for it	488	Example: fork a process and wait for it
491		489
492	my $done = AnyEvent->condvar;	490	my $done = AnyEvent->condvar;
493		491
…		…
507		505
508	=head2 IDLE WATCHERS	506	=head2 IDLE WATCHERS
509		507
510	$w = AnyEvent->idle (cb => <callback>);	508	$w = AnyEvent->idle (cb => <callback>);
511		509
512	Repeatedly invoke the callback after the process becomes idle, until	510	This will repeatedly invoke the callback after the process becomes idle,
513	either the watcher is destroyed or new events have been detected.	511	until either the watcher is destroyed or new events have been detected.
514		512
515	Idle watchers are useful when there is a need to do something, but it	513	Idle watchers are useful when there is a need to do something, but it
516	is not so important (or wise) to do it instantly. The callback will be	514	is not so important (or wise) to do it instantly. The callback will be
517	invoked only when there is "nothing better to do", which is usually	515	invoked only when there is "nothing better to do", which is usually
518	defined as "all outstanding events have been handled and no new events	516	defined as "all outstanding events have been handled and no new events
…		…
588	the signal fires.	586	the signal fires.
589		587
590	=item * Condition variables are like "Merge Points" - points in your program	588	=item * Condition variables are like "Merge Points" - points in your program
591	where you merge multiple independent results/control flows into one.	589	where you merge multiple independent results/control flows into one.
592		590
593	=item * Condition variables represent a transaction - function that start	591	=item * Condition variables represent a transaction - functions that start
594	some kind of transaction can return them, leaving the caller the choice	592	some kind of transaction can return them, leaving the caller the choice
595	between waiting in a blocking fashion, or setting a callback.	593	between waiting in a blocking fashion, or setting a callback.
596		594
597	=item * Condition variables represent future values, or promises to deliver	595	=item * Condition variables represent future values, or promises to deliver
598	some result, long before the result is available.	596	some result, long before the result is available.
…		…
618		616
619	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
620	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
621	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
622	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
623	it's C<new> method in your own C<new> method.	621	its C<new> method in your own C<new> method.
624		622
625	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
626	eventually calls C<< -> send >>, and the "consumer side", which waits	624	eventually calls C<< -> send >>, and the "consumer side", which waits
627	for the send to occur.	625	for the send to occur.
628		626
…		…
693	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
694	C<send>.	692	C<send>.
695		693
696	=item $cv->croak ($error)	694	=item $cv->croak ($error)
697		695
698	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
699	C<Carp::croak> with the given error message/object/scalar.	697	C<Carp::croak> with the given error message/object/scalar.
700		698
701	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
702	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
703	delays the error detetcion, but has the overwhelmign advantage that it	701	delays the error detection, but has the overwhelming advantage that it
704	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
705	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
706	the problem.	704	the problem.
707		705
708	=item $cv->begin ([group callback])	706	=item $cv->begin ([group callback])
709		707
710	=item $cv->end	708	=item $cv->end
…		…
748	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
749	sending.	747	sending.
750		748
751	The ping example mentioned above is slightly more complicated, as the	749	The ping example mentioned above is slightly more complicated, as the
752	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
753	begung can potentially be zero:	751	begun can potentially be zero:
754		752
755	my $cv = AnyEvent->condvar;	753	my $cv = AnyEvent->condvar;
756		754
757	my %result;	755	my %result;
758	$cv->begin (sub { shift->send (\%result) });	756	$cv->begin (sub { shift->send (\%result) });
…		…
779	to be called once the counter reaches C<0>, and second, it ensures that	777	to be called once the counter reaches C<0>, and second, it ensures that
780	C<send> is called even when C<no> hosts are being pinged (the loop	778	C<send> is called even when C<no> hosts are being pinged (the loop
781	doesn't execute once).	779	doesn't execute once).
782		780
783	This is the general pattern when you "fan out" into multiple (but	781	This is the general pattern when you "fan out" into multiple (but
784	potentially none) subrequests: use an outer C<begin>/C<end> pair to set	782	potentially zero) subrequests: use an outer C<begin>/C<end> pair to set
785	the callback and ensure C<end> is called at least once, and then, for each	783	the callback and ensure C<end> is called at least once, and then, for each
786	subrequest you start, call C<begin> and for each subrequest you finish,	784	subrequest you start, call C<begin> and for each subrequest you finish,
787	call C<end>.	785	call C<end>.
788		786
789	=back	787	=back
…		…
796	=over 4	794	=over 4
797		795
798	=item $cv->recv	796	=item $cv->recv
799		797
800	Wait (blocking if necessary) until the C<< ->send >> or C<< ->croak	798	Wait (blocking if necessary) until the C<< ->send >> or C<< ->croak
801	>> methods have been called on c<$cv>, while servicing other watchers	799	>> methods have been called on C<$cv>, while servicing other watchers
802	normally.	800	normally.
803		801
804	You can only wait once on a condition - additional calls are valid but	802	You can only wait once on a condition - additional calls are valid but
805	will return immediately.	803	will return immediately.
806		804
…		…
823	caller decide whether the call will block or not (for example, by coupling	821	caller decide whether the call will block or not (for example, by coupling
824	condition variables with some kind of request results and supporting	822	condition variables with some kind of request results and supporting
825	callbacks so the caller knows that getting the result will not block,	823	callbacks so the caller knows that getting the result will not block,
826	while still supporting blocking waits if the caller so desires).	824	while still supporting blocking waits if the caller so desires).
827		825
828	You can ensure that C<< -recv >> never blocks by setting a callback and	826	You can ensure that C<< ->recv >> never blocks by setting a callback and
829	only calling C<< ->recv >> from within that callback (or at a later	827	only calling C<< ->recv >> from within that callback (or at a later
830	time). This will work even when the event loop does not support blocking	828	time). This will work even when the event loop does not support blocking
831	waits otherwise.	829	waits otherwise.
832		830
833	=item $bool = $cv->ready	831	=item $bool = $cv->ready
…		…
838	=item $cb = $cv->cb ($cb->($cv))	836	=item $cb = $cv->cb ($cb->($cv))
839		837
840	This is a mutator function that returns the callback set and optionally	838	This is a mutator function that returns the callback set and optionally
841	replaces it before doing so.	839	replaces it before doing so.
842		840
843	The callback will be called when the condition becomes (or already was)	841	The callback will be called when the condition becomes "true", i.e. when
844	"true", i.e. when C<send> or C<croak> are called (or were called), with	842	C<send> or C<croak> are called, with the only argument being the
845	the only argument being the condition variable itself. Calling C<recv>	843	condition variable itself. If the condition is already true, the
		844	callback is called immediately when it is set. Calling C<recv> inside
846	inside the callback or at any later time is guaranteed not to block.	845	the callback or at any later time is guaranteed not to block.
847		846
848	=back	847	=back
849		848
850	=head1 SUPPORTED EVENT LOOPS/BACKENDS	849	=head1 SUPPORTED EVENT LOOPS/BACKENDS
851		850
…		…
859	use. If EV is not installed, then AnyEvent will fall back to its own	858	use. If EV is not installed, then AnyEvent will fall back to its own
860	pure-perl implementation, which is available everywhere as it comes with	859	pure-perl implementation, which is available everywhere as it comes with
861	AnyEvent itself.	860	AnyEvent itself.
862		861
863	AnyEvent::Impl::EV based on EV (interface to libev, best choice).	862	AnyEvent::Impl::EV based on EV (interface to libev, best choice).
864	AnyEvent::Impl::Perl pure-perl implementation, fast and portable.	863	AnyEvent::Impl::Perl pure-perl AnyEvent::Loop, fast and portable.
865		864
866	=item Backends that are transparently being picked up when they are used.	865	=item Backends that are transparently being picked up when they are used.
867		866
868	These will be used when they are currently loaded when the first watcher	867	These will be used if they are already loaded when the first watcher
869	is created, in which case it is assumed that the application is using	868	is created, in which case it is assumed that the application is using
870	them. This means that AnyEvent will automatically pick the right backend	869	them. This means that AnyEvent will automatically pick the right backend
871	when the main program loads an event module before anything starts to	870	when the main program loads an event module before anything starts to
872	create watchers. Nothing special needs to be done by the main program.	871	create watchers. Nothing special needs to be done by the main program.
873		872
…		…
875	AnyEvent::Impl::Glib based on Glib, slow but very stable.	874	AnyEvent::Impl::Glib based on Glib, slow but very stable.
876	AnyEvent::Impl::Tk based on Tk, very broken.	875	AnyEvent::Impl::Tk based on Tk, very broken.
877	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.	876	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
878	AnyEvent::Impl::POE based on POE, very slow, some limitations.	877	AnyEvent::Impl::POE based on POE, very slow, some limitations.
879	AnyEvent::Impl::Irssi used when running within irssi.	878	AnyEvent::Impl::Irssi used when running within irssi.
		879	AnyEvent::Impl::IOAsync based on IO::Async.
		880	AnyEvent::Impl::Cocoa based on Cocoa::EventLoop.
		881	AnyEvent::Impl::FLTK based on FLTK (fltk 2 binding).
880		882
881	=item Backends with special needs.	883	=item Backends with special needs.
882		884
883	Qt requires the Qt::Application to be instantiated first, but will	885	Qt requires the Qt::Application to be instantiated first, but will
884	otherwise be picked up automatically. As long as the main program	886	otherwise be picked up automatically. As long as the main program
885	instantiates the application before any AnyEvent watchers are created,	887	instantiates the application before any AnyEvent watchers are created,
886	everything should just work.	888	everything should just work.
887		889
888	AnyEvent::Impl::Qt based on Qt.	890	AnyEvent::Impl::Qt based on Qt.
889		891
890	Support for IO::Async can only be partial, as it is too broken and
891	architecturally limited to even support the AnyEvent API. It also
892	is the only event loop that needs the loop to be set explicitly, so
893	it can only be used by a main program knowing about AnyEvent. See
894	L<AnyEvent::Impl::Async> for the gory details.
895
896	AnyEvent::Impl::IOAsync based on IO::Async, cannot be autoprobed.
897
898	=item Event loops that are indirectly supported via other backends.	892	=item Event loops that are indirectly supported via other backends.
899		893
900	Some event loops can be supported via other modules:	894	Some event loops can be supported via other modules:
901		895
902	There is no direct support for WxWidgets (L<Wx>) or L<Prima>.	896	There is no direct support for WxWidgets (L<Wx>) or L<Prima>.
…		…
927	Contains C<undef> until the first watcher is being created, before the	921	Contains C<undef> until the first watcher is being created, before the
928	backend has been autodetected.	922	backend has been autodetected.
929		923
930	Afterwards it contains the event model that is being used, which is the	924	Afterwards it contains the event model that is being used, which is the
931	name of the Perl class implementing the model. This class is usually one	925	name of the Perl class implementing the model. This class is usually one
932	of the C<AnyEvent::Impl:xxx> modules, but can be any other class in the	926	of the C<AnyEvent::Impl::xxx> modules, but can be any other class in the
933	case AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode> it	927	case AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode> it
934	will be C<urxvt::anyevent>).	928	will be C<urxvt::anyevent>).
935		929
936	=item AnyEvent::detect	930	=item AnyEvent::detect
937		931
938	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model	932	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model
939	if necessary. You should only call this function right before you would	933	if necessary. You should only call this function right before you would
940	have created an AnyEvent watcher anyway, that is, as late as possible at	934	have created an AnyEvent watcher anyway, that is, as late as possible at
941	runtime, and not e.g. while initialising of your module.	935	runtime, and not e.g. during initialisation of your module.
		936
		937	The effect of calling this function is as if a watcher had been created
		938	(specifically, actions that happen "when the first watcher is created"
		939	happen when calling detetc as well).
942		940
943	If you need to do some initialisation before AnyEvent watchers are	941	If you need to do some initialisation before AnyEvent watchers are
944	created, use C<post_detect>.	942	created, use C<post_detect>.
945		943
946	=item $guard = AnyEvent::post_detect { BLOCK }	944	=item $guard = AnyEvent::post_detect { BLOCK }
947		945
948	Arranges for the code block to be executed as soon as the event model is	946	Arranges for the code block to be executed as soon as the event model is
949	autodetected (or immediately if this has already happened).	947	autodetected (or immediately if that has already happened).
950		948
951	The block will be executed I<after> the actual backend has been detected	949	The block will be executed I<after> the actual backend has been detected
952	(C<$AnyEvent::MODEL> is set), but I<before> any watchers have been	950	(C<$AnyEvent::MODEL> is set), but I<before> any watchers have been
953	created, so it is possible to e.g. patch C<@AnyEvent::ISA> or do	951	created, so it is possible to e.g. patch C<@AnyEvent::ISA> or do
954	other initialisations - see the sources of L<AnyEvent::Strict> or	952	other initialisations - see the sources of L<AnyEvent::Strict> or
…		…
963	that automatically removes the callback again when it is destroyed (or	961	that automatically removes the callback again when it is destroyed (or
964	C<undef> when the hook was immediately executed). See L<AnyEvent::AIO> for	962	C<undef> when the hook was immediately executed). See L<AnyEvent::AIO> for
965	a case where this is useful.	963	a case where this is useful.
966		964
967	Example: Create a watcher for the IO::AIO module and store it in	965	Example: Create a watcher for the IO::AIO module and store it in
968	C<$WATCHER>. Only do so after the event loop is initialised, though.	966	C<$WATCHER>, but do so only do so after the event loop is initialised.
969		967
970	our WATCHER;	968	our WATCHER;
971		969
972	my $guard = AnyEvent::post_detect {	970	my $guard = AnyEvent::post_detect {
973	$WATCHER = AnyEvent->io (fh => IO::AIO::poll_fileno, poll => 'r', cb => \&IO::AIO::poll_cb);	971	$WATCHER = AnyEvent->io (fh => IO::AIO::poll_fileno, poll => 'r', cb => \&IO::AIO::poll_cb);
…		…
981	$WATCHER ||= $guard;	979	$WATCHER ||= $guard;
982		980
983	=item @AnyEvent::post_detect	981	=item @AnyEvent::post_detect
984		982
985	If there are any code references in this array (you can C<push> to it	983	If there are any code references in this array (you can C<push> to it
986	before or after loading AnyEvent), then they will called directly after	984	before or after loading AnyEvent), then they will be called directly
987	the event loop has been chosen.	985	after the event loop has been chosen.
988		986
989	You should check C<$AnyEvent::MODEL> before adding to this array, though:	987	You should check C<$AnyEvent::MODEL> before adding to this array, though:
990	if it is defined then the event loop has already been detected, and the	988	if it is defined then the event loop has already been detected, and the
991	array will be ignored.	989	array will be ignored.
992		990
…		…
1009	# AnyEvent not yet initialised, so make sure to load Coro::AnyEvent	1007	# AnyEvent not yet initialised, so make sure to load Coro::AnyEvent
1010	# as soon as it is	1008	# as soon as it is
1011	push @AnyEvent::post_detect, sub { require Coro::AnyEvent };	1009	push @AnyEvent::post_detect, sub { require Coro::AnyEvent };
1012	}	1010	}
1013		1011
		1012	=item AnyEvent::postpone { BLOCK }
		1013
		1014	Arranges for the block to be executed as soon as possible, but not before
		1015	the call itself returns. In practise, the block will be executed just
		1016	before the event loop polls for new events, or shortly afterwards.
		1017
		1018	This function never returns anything (to make the C<return postpone { ...
		1019	}> idiom more useful.
		1020
		1021	To understand the usefulness of this function, consider a function that
		1022	asynchronously does something for you and returns some transaction
		1023	object or guard to let you cancel the operation. For example,
		1024	C<AnyEvent::Socket::tcp_connect>:
		1025
		1026	# start a conenction attempt unless one is active
		1027	$self->{connect_guard} ||= AnyEvent::Socket::tcp_connect "www.example.net", 80, sub {
		1028	delete $self->{connect_guard};
		1029	...
		1030	};
		1031
		1032	Imagine that this function could instantly call the callback, for
		1033	example, because it detects an obvious error such as a negative port
		1034	number. Invoking the callback before the function returns causes problems
		1035	however: the callback will be called and will try to delete the guard
		1036	object. But since the function hasn't returned yet, there is nothing to
		1037	delete. When the function eventually returns it will assign the guard
		1038	object to C<< $self->{connect_guard} >>, where it will likely never be
		1039	deleted, so the program thinks it is still trying to connect.
		1040
		1041	This is where C<AnyEvent::postpone> should be used. Instead of calling the
		1042	callback directly on error:
		1043
		1044	$cb->(undef), return # signal error to callback, BAD!
		1045	if $some_error_condition;
		1046
		1047	It should use C<postpone>:
		1048
		1049	AnyEvent::postpone { $cb->(undef) }, return # signal error to callback, later
		1050	if $some_error_condition;
		1051
		1052	=item AnyEvent::log $level, $msg[, @args]
		1053
		1054	Log the given C<$msg> at the given C<$level>.
		1055
		1056	If L<AnyEvent::Log> is not loaded then this function makes a simple test
		1057	to see whether the message will be logged. If the test succeeds it will
		1058	load AnyEvent::Log and call C<AnyEvent::Log::log> - consequently, look at
		1059	the L<AnyEvent::Log> documentation for details.
		1060
		1061	If the test fails it will simply return. Right now this happens when a
		1062	numerical loglevel is used and it is larger than the level specified via
		1063	C<$ENV{PERL_ANYEVENT_VERBOSE}>.
		1064
		1065	If you want to sprinkle loads of logging calls around your code, consider
		1066	creating a logger callback with the C<AnyEvent::Log::logger> function,
		1067	which can reduce typing, codesize and can reduce the logging overhead
		1068	enourmously.
		1069
1014	=back	1070	=back
1015		1071
1016	=head1 WHAT TO DO IN A MODULE	1072	=head1 WHAT TO DO IN A MODULE
1017		1073
1018	As a module author, you should C<use AnyEvent> and call AnyEvent methods	1074	As a module author, you should C<use AnyEvent> and call AnyEvent methods
…		…
1028	because it will stall the whole program, and the whole point of using	1084	because it will stall the whole program, and the whole point of using
1029	events is to stay interactive.	1085	events is to stay interactive.
1030		1086
1031	It is fine, however, to call C<< ->recv >> when the user of your module	1087	It is fine, however, to call C<< ->recv >> when the user of your module
1032	requests it (i.e. if you create a http request object ad have a method	1088	requests it (i.e. if you create a http request object ad have a method
1033	called C<results> that returns the results, it should call C<< ->recv >>	1089	called C<results> that returns the results, it may call C<< ->recv >>
1034	freely, as the user of your module knows what she is doing. always).	1090	freely, as the user of your module knows what she is doing. Always).
1035		1091
1036	=head1 WHAT TO DO IN THE MAIN PROGRAM	1092	=head1 WHAT TO DO IN THE MAIN PROGRAM
1037		1093
1038	There will always be a single main program - the only place that should	1094	There will always be a single main program - the only place that should
1039	dictate which event model to use.	1095	dictate which event model to use.
1040		1096
1041	If it doesn't care, it can just "use AnyEvent" and use it itself, or not	1097	If the program is not event-based, it need not do anything special, even
1042	do anything special (it does not need to be event-based) and let AnyEvent	1098	when it depends on a module that uses an AnyEvent. If the program itself
1043	decide which implementation to chose if some module relies on it.	1099	uses AnyEvent, but does not care which event loop is used, all it needs
		1100	to do is C<use AnyEvent>. In either case, AnyEvent will choose the best
		1101	available loop implementation.
1044		1102
1045	If the main program relies on a specific event model - for example, in	1103	If the main program relies on a specific event model - for example, in
1046	Gtk2 programs you have to rely on the Glib module - you should load the	1104	Gtk2 programs you have to rely on the Glib module - you should load the
1047	event module before loading AnyEvent or any module that uses it: generally	1105	event module before loading AnyEvent or any module that uses it: generally
1048	speaking, you should load it as early as possible. The reason is that	1106	speaking, you should load it as early as possible. The reason is that
1049	modules might create watchers when they are loaded, and AnyEvent will	1107	modules might create watchers when they are loaded, and AnyEvent will
1050	decide on the event model to use as soon as it creates watchers, and it	1108	decide on the event model to use as soon as it creates watchers, and it
1051	might chose the wrong one unless you load the correct one yourself.	1109	might choose the wrong one unless you load the correct one yourself.
1052		1110
1053	You can chose to use a pure-perl implementation by loading the	1111	You can chose to use a pure-perl implementation by loading the
1054	C<AnyEvent::Impl::Perl> module, which gives you similar behaviour	1112	C<AnyEvent::Loop> module, which gives you similar behaviour
1055	everywhere, but letting AnyEvent chose the model is generally better.	1113	everywhere, but letting AnyEvent chose the model is generally better.
1056		1114
1057	=head2 MAINLOOP EMULATION	1115	=head2 MAINLOOP EMULATION
1058		1116
1059	Sometimes (often for short test scripts, or even standalone programs who	1117	Sometimes (often for short test scripts, or even standalone programs who
…		…
1072		1130
1073		1131
1074	=head1 OTHER MODULES	1132	=head1 OTHER MODULES
1075		1133
1076	The following is a non-exhaustive list of additional modules that use	1134	The following is a non-exhaustive list of additional modules that use
1077	AnyEvent as a client and can therefore be mixed easily with other AnyEvent	1135	AnyEvent as a client and can therefore be mixed easily with other
1078	modules and other event loops in the same program. Some of the modules	1136	AnyEvent modules and other event loops in the same program. Some of the
1079	come as part of AnyEvent, the others are available via CPAN.	1137	modules come as part of AnyEvent, the others are available via CPAN (see
		1138	L<http://search.cpan.org/search?m=module&q=anyevent%3A%3A*> for
		1139	a longer non-exhaustive list), and the list is heavily biased towards
		1140	modules of the AnyEvent author himself :)
1080		1141
1081	=over 4	1142	=over 4
1082		1143
1083	=item L<AnyEvent::Util>	1144	=item L<AnyEvent::Util>
1084		1145
1085	Contains various utility functions that replace often-used but blocking	1146	Contains various utility functions that replace often-used blocking
1086	functions such as C<inet_aton> by event-/callback-based versions.	1147	functions such as C<inet_aton> with event/callback-based versions.
1087		1148
1088	=item L<AnyEvent::Socket>	1149	=item L<AnyEvent::Socket>
1089		1150
1090	Provides various utility functions for (internet protocol) sockets,	1151	Provides various utility functions for (internet protocol) sockets,
1091	addresses and name resolution. Also functions to create non-blocking tcp	1152	addresses and name resolution. Also functions to create non-blocking tcp
…		…
1093		1154
1094	=item L<AnyEvent::Handle>	1155	=item L<AnyEvent::Handle>
1095		1156
1096	Provide read and write buffers, manages watchers for reads and writes,	1157	Provide read and write buffers, manages watchers for reads and writes,
1097	supports raw and formatted I/O, I/O queued and fully transparent and	1158	supports raw and formatted I/O, I/O queued and fully transparent and
1098	non-blocking SSL/TLS (via L<AnyEvent::TLS>.	1159	non-blocking SSL/TLS (via L<AnyEvent::TLS>).
1099		1160
1100	=item L<AnyEvent::DNS>	1161	=item L<AnyEvent::DNS>
1101		1162
1102	Provides rich asynchronous DNS resolver capabilities.	1163	Provides rich asynchronous DNS resolver capabilities.
1103		1164
1104	=item L<AnyEvent::HTTP>, L<AnyEvent::IRC>, L<AnyEvent::XMPP>, L<AnyEvent::GPSD>, L<AnyEvent::IGS>, L<AnyEvent::FCP>	1165	=item L<AnyEvent::HTTP>, L<AnyEvent::IRC>, L<AnyEvent::XMPP>, L<AnyEvent::GPSD>, L<AnyEvent::IGS>, L<AnyEvent::FCP>
1105		1166
1106	Implement event-based interfaces to the protocols of the same name (for	1167	Implement event-based interfaces to the protocols of the same name (for
1107	the curious, IGS is the International Go Server and FCP is the Freenet	1168	the curious, IGS is the International Go Server and FCP is the Freenet
1108	Client Protocol).	1169	Client Protocol).
1109
1110	=item L<AnyEvent::Handle::UDP>
1111
1112	Here be danger!
1113
1114	As Pauli would put it, "Not only is it not right, it's not even wrong!" -
1115	there are so many things wrong with AnyEvent::Handle::UDP, most notably
1116	it's use of a stream-based API with a protocol that isn't streamable, that
1117	the only way to improve it is to delete it.
1118
1119	It features data corruption (but typically only under load) and general
1120	confusion. On top, the author is not only clueless about UDP but also
1121	fact-resistant - some gems of his understanding: "connect doesn't work
1122	with UDP", "UDP packets are not IP packets", "UDP only has datagrams, not
1123	packets", "I don't need to implement proper error checking as UDP doesn't
1124	support error checking" and so on - he doesn't even understand what's
1125	wrong with his module when it is explained to him.
1126
1127	=item L<AnyEvent::DBI>
1128
1129	Executes L<DBI> requests asynchronously in a proxy process for you,
1130	notifying you in an event-bnased way when the operation is finished.
1131		1170
1132	=item L<AnyEvent::AIO>	1171	=item L<AnyEvent::AIO>
1133		1172
1134	Truly asynchronous (as opposed to non-blocking) I/O, should be in the	1173	Truly asynchronous (as opposed to non-blocking) I/O, should be in the
1135	toolbox of every event programmer. AnyEvent::AIO transparently fuses	1174	toolbox of every event programmer. AnyEvent::AIO transparently fuses
1136	L<IO::AIO> and AnyEvent together, giving AnyEvent access to event-based	1175	L<IO::AIO> and AnyEvent together, giving AnyEvent access to event-based
1137	file I/O, and much more.	1176	file I/O, and much more.
1138		1177
		1178	=item L<AnyEvent::Filesys::Notify>
		1179
		1180	AnyEvent is good for non-blocking stuff, but it can't detect file or
		1181	path changes (e.g. "watch this directory for new files", "watch this
		1182	file for changes"). The L<AnyEvent::Filesys::Notify> module promises to
		1183	do just that in a portbale fashion, supporting inotify on GNU/Linux and
		1184	some weird, without doubt broken, stuff on OS X to monitor files. It can
		1185	fall back to blocking scans at regular intervals transparently on other
		1186	platforms, so it's about as portable as it gets.
		1187
		1188	(I haven't used it myself, but I haven't heard anybody complaining about
		1189	it yet).
		1190
		1191	=item L<AnyEvent::DBI>
		1192
		1193	Executes L<DBI> requests asynchronously in a proxy process for you,
		1194	notifying you in an event-based way when the operation is finished.
		1195
1139	=item L<AnyEvent::HTTPD>	1196	=item L<AnyEvent::HTTPD>
1140		1197
1141	A simple embedded webserver.	1198	A simple embedded webserver.
1142		1199
1143	=item L<AnyEvent::FastPing>	1200	=item L<AnyEvent::FastPing>
1144		1201
1145	The fastest ping in the west.	1202	The fastest ping in the west.
1146		1203
1147	=item L<Coro>	1204	=item L<Coro>
1148		1205
1149	Has special support for AnyEvent via L<Coro::AnyEvent>.	1206	Has special support for AnyEvent via L<Coro::AnyEvent>, which allows you
		1207	to simply invert the flow control - don't call us, we will call you:
		1208
		1209	async {
		1210	Coro::AnyEvent::sleep 5; # creates a 5s timer and waits for it
		1211	print "5 seconds later!\n";
		1212
		1213	Coro::AnyEvent::readable *STDIN; # uses an I/O watcher
		1214	my $line = <STDIN>; # works for ttys
		1215
		1216	AnyEvent::HTTP::http_get "url", Coro::rouse_cb;
		1217	my ($body, $hdr) = Coro::rouse_wait;
		1218	};
1150		1219
1151	=back	1220	=back
1152		1221
1153	=cut	1222	=cut
1154		1223
1155	package AnyEvent;	1224	package AnyEvent;
1156		1225
1157	# basically a tuned-down version of common::sense	1226	# basically a tuned-down version of common::sense
1158	sub common_sense {	1227	sub common_sense {
1159	# from common:.sense 1.0	1228	# from common:.sense 3.4
1160	${^WARNING_BITS} = "\xfc\x3f\x33\x00\x0f\xf3\xcf\xc0\xf3\xfc\x33\x00";	1229	${^WARNING_BITS} ^= ${^WARNING_BITS} ^ "\x3c\x3f\x33\x00\x0f\xf0\x0f\xc0\xf0\xfc\x33\x00";
1161	# use strict vars subs - NO UTF-8, as Util.pm doesn't like this atm. (uts46data.pl)	1230	# use strict vars subs - NO UTF-8, as Util.pm doesn't like this atm. (uts46data.pl)
1162	$^H |= 0x00000600;	1231	$^H |= 0x00000600;
1163	}	1232	}
1164		1233
1165	BEGIN { AnyEvent::common_sense }	1234	BEGIN { AnyEvent::common_sense }
1166		1235
1167	use Carp ();	1236	use Carp ();
1168		1237
1169	our $VERSION = '5.271';	1238	our $VERSION = '6.14';
1170	our $MODEL;	1239	our $MODEL;
1171
1172	our $AUTOLOAD;
1173	our @ISA;	1240	our @ISA;
1174
1175	our @REGISTRY;	1241	our @REGISTRY;
1176
1177	our $VERBOSE;	1242	our $VERBOSE;
		1243	our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred
		1244	our $MAX_SIGNAL_LATENCY = $ENV{PERL_ANYEVENT_MAX_SIGNAL_LATENCY} || 10; # executes after the BEGIN block below (tainting!)
1178		1245
1179	BEGIN {	1246	BEGIN {
1180	require "AnyEvent/constants.pl";	1247	require "AnyEvent/constants.pl";
1181		1248
1182	eval "sub TAINT (){" . (${^TAINT}*1) . "}";	1249	eval "sub TAINT (){" . (${^TAINT}*1) . "}";
1183		1250
1184	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}	1251	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}
1185	if ${^TAINT};	1252	if ${^TAINT};
1186		1253
1187	$VERBOSE = $ENV{PERL_ANYEVENT_VERBOSE}*1;	1254	$ENV{"PERL_ANYEVENT_$_"} = $ENV{"AE_$_"}
		1255	for grep s/^AE_// && !exists $ENV{"PERL_ANYEVENT_$_"}, keys %ENV;
1188		1256
1189	}	1257	@ENV{grep /^PERL_ANYEVENT_/, keys %ENV} = ()
		1258	if ${^TAINT};
1190		1259
1191	our $MAX_SIGNAL_LATENCY = 10;	1260	# $ENV{PERL_ANYEVENT_xxx} now valid
1192		1261
1193	our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred	1262	$VERBOSE = length $ENV{PERL_ANYEVENT_VERBOSE} ? $ENV{PERL_ANYEVENT_VERBOSE}*1 : 4;
1194		1263
1195	{
1196	my $idx;	1264	my $idx;
1197	$PROTOCOL{$_} = ++$idx	1265	$PROTOCOL{$_} = ++$idx
1198	for reverse split /\s*,\s*/,	1266	for reverse split /\s*,\s*/,
1199	$ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";	1267	$ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";
1200	}	1268	}
1201		1269
		1270	our @post_detect;
		1271
		1272	sub post_detect(&) {
		1273	my ($cb) = @_;
		1274
		1275	push @post_detect, $cb;
		1276
		1277	defined wantarray
		1278	? bless \$cb, "AnyEvent::Util::postdetect"
		1279	: ()
		1280	}
		1281
		1282	sub AnyEvent::Util::postdetect::DESTROY {
		1283	@post_detect = grep $_ != ${$_[0]}, @post_detect;
		1284	}
		1285
		1286	our $POSTPONE_W;
		1287	our @POSTPONE;
		1288
		1289	sub _postpone_exec {
		1290	undef $POSTPONE_W;
		1291
		1292	&{ shift @POSTPONE }
		1293	while @POSTPONE;
		1294	}
		1295
		1296	sub postpone(&) {
		1297	push @POSTPONE, shift;
		1298
		1299	$POSTPONE_W ||= AE::timer (0, 0, \&_postpone_exec);
		1300
		1301	()
		1302	}
		1303
		1304	sub log($$;@) {
		1305	# only load the big bloated module when we actually are about to log something
		1306	if ($_[0] <= ($VERBOSE || 1)) { # also catches non-numeric levels(!) and fatal
		1307	local ($!, $@);
		1308	require AnyEvent::Log; # among other things, sets $VERBOSE to 9
		1309	# AnyEvent::Log overwrites this function
		1310	goto &log;
		1311	}
		1312
		1313	0 # not logged
		1314	}
		1315
		1316	sub _logger($;$) {
		1317	my ($level, $renabled) = @_;
		1318
		1319	$$renabled = $level <= $VERBOSE;
		1320
		1321	my $logger = [(caller)[0], $level, $renabled];
		1322
		1323	$AnyEvent::Log::LOGGER{$logger+0} = $logger;
		1324
		1325	# return unless defined wantarray;
		1326	#
		1327	# require AnyEvent::Util;
		1328	# my $guard = AnyEvent::Util::guard (sub {
		1329	# # "clean up"
		1330	# delete $LOGGER{$logger+0};
		1331	# });
		1332	#
		1333	# sub {
		1334	# return 0 unless $$renabled;
		1335	#
		1336	# $guard if 0; # keep guard alive, but don't cause runtime overhead
		1337	# require AnyEvent::Log unless $AnyEvent::Log::VERSION;
		1338	# package AnyEvent::Log;
		1339	# _log ($logger->[0], $level, @_) # logger->[0] has been converted at load time
		1340	# }
		1341	}
		1342
		1343	if (length $ENV{PERL_ANYEVENT_LOG}) {
		1344	require AnyEvent::Log; # AnyEvent::Log does the thing for us
		1345	}
		1346
1202	my @models = (	1347	our @models = (
1203	[EV:: => AnyEvent::Impl::EV:: , 1],	1348	[EV:: => AnyEvent::Impl::EV::],
1204	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl:: , 1],	1349	[AnyEvent::Loop:: => AnyEvent::Impl::Perl::],
1205	# everything below here will not (normally) be autoprobed	1350	# everything below here will not (normally) be autoprobed
1206	# as the pureperl backend should work everywhere	1351	# as the pure perl backend should work everywhere
1207	# and is usually faster	1352	# and is usually faster
		1353	[Irssi:: => AnyEvent::Impl::Irssi::], # Irssi has a bogus "Event" package, so msut be near the top
1208	[Event:: => AnyEvent::Impl::Event::, 1],	1354	[Event:: => AnyEvent::Impl::Event::], # slow, stable
1209	[Glib:: => AnyEvent::Impl::Glib:: , 1], # becomes extremely slow with many watchers	1355	[Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers
		1356	# everything below here should not be autoloaded
1210	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy	1357	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
1211	[Irssi:: => AnyEvent::Impl::Irssi::], # Irssi has a bogus "Event" package
1212	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles	1358	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
1213	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program	1359	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program
1214	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza	1360	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
1215	[Wx:: => AnyEvent::Impl::POE::],	1361	[Wx:: => AnyEvent::Impl::POE::],
1216	[Prima:: => AnyEvent::Impl::POE::],	1362	[Prima:: => AnyEvent::Impl::POE::],
1217	# IO::Async is just too broken - we would need workarounds for its	1363	[IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # a bitch to autodetect
1218	# byzantine signal and broken child handling, among others.	1364	[Cocoa::EventLoop:: => AnyEvent::Impl::Cocoa::],
1219	# IO::Async is rather hard to detect, as it doesn't have any	1365	[FLTK:: => AnyEvent::Impl::FLTK::],
1220	# obvious default class.
1221	[IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program
1222	[IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program
1223	[IO::Async::Notifier:: => AnyEvent::Impl::IOAsync::], # requires special main program
1224	[AnyEvent::Impl::IOAsync:: => AnyEvent::Impl::IOAsync::], # requires special main program
1225	);	1366	);
1226		1367
1227	our %method = map +($_ => 1),	1368	our @isa_hook;
		1369
		1370	sub _isa_set {
		1371	my @pkg = ("AnyEvent", (map $_->[0], grep defined, @isa_hook), $MODEL);
		1372
		1373	@{"$pkg[$_-1]::ISA"} = $pkg[$_]
		1374	for 1 .. $#pkg;
		1375
		1376	grep $_ && $_->[1], @isa_hook
		1377	and AE::_reset ();
		1378	}
		1379
		1380	# used for hooking AnyEvent::Strict and AnyEvent::Debug::Wrap into the class hierarchy
		1381	sub _isa_hook($$;$) {
		1382	my ($i, $pkg, $reset_ae) = @_;
		1383
		1384	$isa_hook[$i] = $pkg ? [$pkg, $reset_ae] : undef;
		1385
		1386	_isa_set;
		1387	}
		1388
		1389	# all autoloaded methods reserve the complete glob, not just the method slot.
		1390	# due to bugs in perls method cache implementation.
1228	qw(io timer time now now_update signal child idle condvar one_event DESTROY);	1391	our @methods = qw(io timer time now now_update signal child idle condvar);
1229
1230	our @post_detect;
1231
1232	sub post_detect(&) {
1233	my ($cb) = @_;
1234
1235	push @post_detect, $cb;
1236
1237	defined wantarray
1238	? bless \$cb, "AnyEvent::Util::postdetect"
1239	: ()
1240	}
1241
1242	sub AnyEvent::Util::postdetect::DESTROY {
1243	@post_detect = grep $_ != ${$_[0]}, @post_detect;
1244	}
1245		1392
1246	sub detect() {	1393	sub detect() {
		1394	return $MODEL if $MODEL; # some programs keep references to detect
		1395
		1396	# IO::Async::Loop::AnyEvent is extremely evil, refuse to work with it
		1397	# the author knows about the problems and what it does to AnyEvent as a whole
		1398	# (and the ability of others to use AnyEvent), but simply wants to abuse AnyEvent
		1399	# anyway.
		1400	AnyEvent::log fatal => "AnyEvent: IO::Async::Loop::AnyEvent detected - that module is broken by\n"
		1401	. "design, abuses internals and breaks AnyEvent - will not continue."
		1402	if exists $INC{"IO/Async/Loop/AnyEvent.pm"};
		1403
		1404	local $!; # for good measure
		1405	local $SIG{__DIE__}; # we use eval
		1406
1247	# free some memory	1407	# free some memory
1248	*detect = sub () { $MODEL };	1408	*detect = sub () { $MODEL };
		1409	# undef &func doesn't correctly update the method cache. grmbl.
		1410	# so we delete the whole glob. grmbl.
		1411	# otoh, perl doesn't let me undef an active usb, but it lets me free
		1412	# a glob with an active sub. hrm. i hope it works, but perl is
		1413	# usually buggy in this department. sigh.
		1414	delete @{"AnyEvent::"}{@methods};
		1415	undef @methods;
1249		1416
1250	local $!; # for good measure
1251	local $SIG{__DIE__};
1252
1253	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {	1417	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z0-9:]+)$/) {
1254	my $model = "AnyEvent::Impl::$1";	1418	my $model = $1;
		1419	$model = "AnyEvent::Impl::$model" unless $model =~ s/::$//;
1255	if (eval "require $model") {	1420	if (eval "require $model") {
		1421	AnyEvent::log 7 => "loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.";
1256	$MODEL = $model;	1422	$MODEL = $model;
1257	warn "AnyEvent: loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.\n" if $VERBOSE >= 2;
1258	} else {	1423	} else {
1259	warn "AnyEvent: unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@" if $VERBOSE;	1424	AnyEvent::log 4 => "unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@";
1260	}	1425	}
1261	}	1426	}
1262		1427
1263	# check for already loaded models	1428	# check for already loaded models
1264	unless ($MODEL) {	1429	unless ($MODEL) {
1265	for (@REGISTRY, @models) {	1430	for (@REGISTRY, @models) {
1266	my ($package, $model) = @$_;	1431	my ($package, $model) = @$_;
1267	if (${"$package\::VERSION"} > 0) {	1432	if (${"$package\::VERSION"} > 0) {
1268	if (eval "require $model") {	1433	if (eval "require $model") {
		1434	AnyEvent::log 7 => "autodetected model '$model', using it.";
1269	$MODEL = $model;	1435	$MODEL = $model;
1270	warn "AnyEvent: autodetected model '$model', using it.\n" if $VERBOSE >= 2;	1436	last;
		1437	} else {
		1438	AnyEvent::log 8 => "detected event loop $package, but cannot load '$model', skipping: $@";
		1439	}
		1440	}
		1441	}
		1442
		1443	unless ($MODEL) {
		1444	# try to autoload a model
		1445	for (@REGISTRY, @models) {
		1446	my ($package, $model) = @$_;
		1447	if (
		1448	eval "require $package"
		1449	and ${"$package\::VERSION"} > 0
		1450	and eval "require $model"
		1451	) {
		1452	AnyEvent::log 7 => "autoloaded model '$model', using it.";
		1453	$MODEL = $model;
1271	last;	1454	last;
1272	}	1455	}
1273	}	1456	}
1274	}
1275
1276	unless ($MODEL) {
1277	# try to autoload a model
1278	for (@REGISTRY, @models) {
1279	my ($package, $model, $autoload) = @$_;
1280	if (
1281	$autoload
1282	and eval "require $package"
1283	and ${"$package\::VERSION"} > 0
1284	and eval "require $model"
1285	) {
1286	$MODEL = $model;
1287	warn "AnyEvent: autoloaded model '$model', using it.\n" if $VERBOSE >= 2;
1288	last;
1289	}
1290	}
1291		1457
1292	$MODEL	1458	$MODEL
1293	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.\n";	1459	or AnyEvent::log fatal => "AnyEvent: backend autodetection failed - did you properly install AnyEvent?";
1294	}	1460	}
1295	}	1461	}
1296		1462
1297	@models = (); # free probe data	1463	# free memory only needed for probing
		1464	undef @models;
		1465	undef @REGISTRY;
1298		1466
1299	push @{"$MODEL\::ISA"}, "AnyEvent::Base";	1467	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
1300	unshift @ISA, $MODEL;
1301		1468
1302	# now nuke some methods that are overriden by the backend.	1469	# now nuke some methods that are overridden by the backend.
1303	# SUPER is not allowed.	1470	# SUPER usage is not allowed in these.
1304	for (qw(time signal child idle)) {	1471	for (qw(time signal child idle)) {
1305	undef &{"AnyEvent::Base::$_"}	1472	undef &{"AnyEvent::Base::$_"}
1306	if defined &{"$MODEL\::$_"};	1473	if defined &{"$MODEL\::$_"};
1307	}	1474	}
1308		1475
1309	require AnyEvent::Strict if $ENV{PERL_ANYEVENT_STRICT};	1476	_isa_set;
		1477
		1478	# we're officially open!
		1479
		1480	if ($ENV{PERL_ANYEVENT_STRICT}) {
		1481	require AnyEvent::Strict;
		1482	}
		1483
		1484	if ($ENV{PERL_ANYEVENT_DEBUG_WRAP}) {
		1485	require AnyEvent::Debug;
		1486	AnyEvent::Debug::wrap ($ENV{PERL_ANYEVENT_DEBUG_WRAP});
		1487	}
		1488
		1489	if (length $ENV{PERL_ANYEVENT_DEBUG_SHELL}) {
		1490	require AnyEvent::Socket;
		1491	require AnyEvent::Debug;
		1492
		1493	my $shell = $ENV{PERL_ANYEVENT_DEBUG_SHELL};
		1494	$shell =~ s/\$\$/$$/g;
		1495
		1496	my ($host, $service) = AnyEvent::Socket::parse_hostport ($shell);
		1497	$AnyEvent::Debug::SHELL = AnyEvent::Debug::shell ($host, $service);
		1498	}
		1499
		1500	# now the anyevent environment is set up as the user told us to, so
		1501	# call the actual user code - post detects
1310		1502
1311	(shift @post_detect)->() while @post_detect;	1503	(shift @post_detect)->() while @post_detect;
		1504	undef @post_detect;
1312		1505
1313	*post_detect = sub(&) {	1506	*post_detect = sub(&) {
1314	shift->();	1507	shift->();
1315		1508
1316	undef	1509	undef
1317	};	1510	};
1318		1511
1319	$MODEL	1512	$MODEL
1320	}	1513	}
1321		1514
1322	sub AUTOLOAD {	1515	for my $name (@methods) {
1323	(my $func = $AUTOLOAD) =~ s/.*://;	1516	*$name = sub {
1324
1325	$method{$func}
1326	or Carp::croak "$func: not a valid AnyEvent class method";
1327
1328	detect;	1517	detect;
1329		1518	# we use goto because
1330	my $class = shift;	1519	# a) it makes the thunk more transparent
1331	$class->$func (@_);	1520	# b) it allows us to delete the thunk later
		1521	goto &{ UNIVERSAL::can AnyEvent => "SUPER::$name" }
		1522	};
1332	}	1523	}
1333		1524
1334	# utility function to dup a filehandle. this is used by many backends	1525	# utility function to dup a filehandle. this is used by many backends
1335	# to support binding more than one watcher per filehandle (they usually	1526	# to support binding more than one watcher per filehandle (they usually
1336	# allow only one watcher per fd, so we dup it to get a different one).	1527	# allow only one watcher per fd, so we dup it to get a different one).
…		…
1360		1551
1361	package AE;	1552	package AE;
1362		1553
1363	our $VERSION = $AnyEvent::VERSION;	1554	our $VERSION = $AnyEvent::VERSION;
1364		1555
		1556	sub _reset() {
		1557	eval q{
1365	# fall back to the main API by default - backends and AnyEvent::Base	1558	# fall back to the main API by default - backends and AnyEvent::Base
1366	# implementations can overwrite these.	1559	# implementations can overwrite these.
1367		1560
1368	sub io($$$) {	1561	sub io($$$) {
1369	AnyEvent->io (fh => $_[0], poll => $_[1] ? "w" : "r", cb => $_[2])	1562	AnyEvent->io (fh => $_[0], poll => $_[1] ? "w" : "r", cb => $_[2])
1370	}	1563	}
1371		1564
1372	sub timer($$$) {	1565	sub timer($$$) {
1373	AnyEvent->timer (after => $_[0], interval => $_[1], cb => $_[2])	1566	AnyEvent->timer (after => $_[0], interval => $_[1], cb => $_[2])
1374	}	1567	}
1375		1568
1376	sub signal($$) {	1569	sub signal($$) {
1377	AnyEvent->signal (signal => $_[0], cb => $_[1])	1570	AnyEvent->signal (signal => $_[0], cb => $_[1])
1378	}	1571	}
1379		1572
1380	sub child($$) {	1573	sub child($$) {
1381	AnyEvent->child (pid => $_[0], cb => $_[1])	1574	AnyEvent->child (pid => $_[0], cb => $_[1])
1382	}	1575	}
1383		1576
1384	sub idle($) {	1577	sub idle($) {
1385	AnyEvent->idle (cb => $_[0])	1578	AnyEvent->idle (cb => $_[0]);
1386	}	1579	}
1387		1580
1388	sub cv(;&) {	1581	sub cv(;&) {
1389	AnyEvent->condvar (@_ ? (cb => $_[0]) : ())	1582	AnyEvent->condvar (@_ ? (cb => $_[0]) : ())
1390	}	1583	}
1391		1584
1392	sub now() {	1585	sub now() {
1393	AnyEvent->now	1586	AnyEvent->now
1394	}	1587	}
1395		1588
1396	sub now_update() {	1589	sub now_update() {
1397	AnyEvent->now_update	1590	AnyEvent->now_update
1398	}	1591	}
1399		1592
1400	sub time() {	1593	sub time() {
1401	AnyEvent->time	1594	AnyEvent->time
		1595	}
		1596
		1597	*postpone = \&AnyEvent::postpone;
		1598	*log = \&AnyEvent::log;
		1599	};
		1600	die if $@;
1402	}	1601	}
		1602
		1603	BEGIN { _reset }
1403		1604
1404	package AnyEvent::Base;	1605	package AnyEvent::Base;
1405		1606
1406	# default implementations for many methods	1607	# default implementations for many methods
1407		1608
1408	sub time {	1609	sub time {
1409	eval q{ # poor man's autoloading {}	1610	eval q{ # poor man's autoloading {}
1410	# probe for availability of Time::HiRes	1611	# probe for availability of Time::HiRes
1411	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {	1612	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {
1412	warn "AnyEvent: using Time::HiRes for sub-second timing accuracy.\n" if $VERBOSE >= 8;	1613	*time = sub { Time::HiRes::time () };
1413	*AE::time = \&Time::HiRes::time;	1614	*AE::time = \& Time::HiRes::time ;
		1615	*now = \&time;
		1616	AnyEvent::log 8 => "AnyEvent: using Time::HiRes for sub-second timing accuracy.";
1414	# if (eval "use POSIX (); (POSIX::times())...	1617	# if (eval "use POSIX (); (POSIX::times())...
1415	} else {	1618	} else {
		1619	*time = sub { CORE::time };
		1620	*AE::time = sub (){ CORE::time };
		1621	*now = \&time;
1416	warn "AnyEvent: using built-in time(), WARNING, no sub-second resolution!\n" if $VERBOSE;	1622	AnyEvent::log 3 => "using built-in time(), WARNING, no sub-second resolution!";
1417	*AE::time = sub (){ time }; # epic fail
1418	}	1623	}
1419
1420	*time = sub { AE::time }; # different prototypes
1421	};	1624	};
1422	die if $@;	1625	die if $@;
1423		1626
1424	&time	1627	&time
1425	}	1628	}
1426		1629
1427	*now = \&time;	1630	*now = \&time;
1428
1429	sub now_update { }	1631	sub now_update { }
1430		1632
		1633	sub _poll {
		1634	Carp::croak "$AnyEvent::MODEL does not support blocking waits. Caught";
		1635	}
		1636
1431	# default implementation for ->condvar	1637	# default implementation for ->condvar
		1638	# in fact, the default should not be overwritten
1432		1639
1433	sub condvar {	1640	sub condvar {
1434	eval q{ # poor man's autoloading {}	1641	eval q{ # poor man's autoloading {}
1435	*condvar = sub {	1642	*condvar = sub {
1436	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"	1643	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"
…		…
1514		1721
1515	sub signal {	1722	sub signal {
1516	eval q{ # poor man's autoloading {}	1723	eval q{ # poor man's autoloading {}
1517	# probe for availability of Async::Interrupt	1724	# probe for availability of Async::Interrupt
1518	if (_have_async_interrupt) {	1725	if (_have_async_interrupt) {
1519	warn "AnyEvent: using Async::Interrupt for race-free signal handling.\n" if $VERBOSE >= 8;	1726	AnyEvent::log 8 => "using Async::Interrupt for race-free signal handling.";
1520		1727
1521	$SIGPIPE_R = new Async::Interrupt::EventPipe;	1728	$SIGPIPE_R = new Async::Interrupt::EventPipe;
1522	$SIG_IO = AE::io $SIGPIPE_R->fileno, 0, \&_signal_exec;	1729	$SIG_IO = AE::io $SIGPIPE_R->fileno, 0, \&_signal_exec;
1523		1730
1524	} else {	1731	} else {
1525	warn "AnyEvent: using emulated perl signal handling with latency timer.\n" if $VERBOSE >= 8;	1732	AnyEvent::log 8 => "using emulated perl signal handling with latency timer.";
1526		1733
1527	if (AnyEvent::WIN32) {	1734	if (AnyEvent::WIN32) {
1528	require AnyEvent::Util;	1735	require AnyEvent::Util;
1529		1736
1530	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();	1737	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
…		…
1606	: sysread $SIGPIPE_R, (my $dummy), 9;	1813	: sysread $SIGPIPE_R, (my $dummy), 9;
1607		1814
1608	while (%SIG_EV) {	1815	while (%SIG_EV) {
1609	for (keys %SIG_EV) {	1816	for (keys %SIG_EV) {
1610	delete $SIG_EV{$_};	1817	delete $SIG_EV{$_};
1611	$_->() for values %{ $SIG_CB{$_} || {} };	1818	&$_ for values %{ $SIG_CB{$_} || {} };
1612	}	1819	}
1613	}	1820	}
1614	};	1821	};
1615	};	1822	};
1616	die if $@;	1823	die if $@;
…		…
1621	# default implementation for ->child	1828	# default implementation for ->child
1622		1829
1623	our %PID_CB;	1830	our %PID_CB;
1624	our $CHLD_W;	1831	our $CHLD_W;
1625	our $CHLD_DELAY_W;	1832	our $CHLD_DELAY_W;
1626	our $WNOHANG;
1627		1833
1628	# used by many Impl's	1834	# used by many Impl's
1629	sub _emit_childstatus($$) {	1835	sub _emit_childstatus($$) {
1630	my (undef, $rpid, $rstatus) = @_;	1836	my (undef, $rpid, $rstatus) = @_;
1631		1837
…		…
1638	eval q{ # poor man's autoloading {}	1844	eval q{ # poor man's autoloading {}
1639	*_sigchld = sub {	1845	*_sigchld = sub {
1640	my $pid;	1846	my $pid;
1641		1847
1642	AnyEvent->_emit_childstatus ($pid, $?)	1848	AnyEvent->_emit_childstatus ($pid, $?)
1643	while ($pid = waitpid -1, $WNOHANG) > 0;	1849	while ($pid = waitpid -1, WNOHANG) > 0;
1644	};	1850	};
1645		1851
1646	*child = sub {	1852	*child = sub {
1647	my (undef, %arg) = @_;	1853	my (undef, %arg) = @_;
1648		1854
1649	defined (my $pid = $arg{pid} + 0)	1855	my $pid = $arg{pid};
1650	or Carp::croak "required option 'pid' is missing";	1856	my $cb = $arg{cb};
1651		1857
1652	$PID_CB{$pid}{$arg{cb}} = $arg{cb};	1858	$PID_CB{$pid}{$cb+0} = $cb;
1653
1654	# WNOHANG is almost cetrainly 1 everywhere
1655	$WNOHANG ||= $^O =~ /^(?:openbsd|netbsd|linux|freebsd|cygwin|MSWin32)$/
1656	? 1
1657	: eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1;
1658		1859
1659	unless ($CHLD_W) {	1860	unless ($CHLD_W) {
1660	$CHLD_W = AE::signal CHLD => \&_sigchld;	1861	$CHLD_W = AE::signal CHLD => \&_sigchld;
1661	# child could be a zombie already, so make at least one round	1862	# child could be a zombie already, so make at least one round
1662	&_sigchld;	1863	&_sigchld;
1663	}	1864	}
1664		1865
1665	bless [$pid, $arg{cb}], "AnyEvent::Base::child"	1866	bless [$pid, $cb+0], "AnyEvent::Base::child"
1666	};	1867	};
1667		1868
1668	*AnyEvent::Base::child::DESTROY = sub {	1869	*AnyEvent::Base::child::DESTROY = sub {
1669	my ($pid, $cb) = @{$_[0]};	1870	my ($pid, $icb) = @{$_[0]};
1670		1871
1671	delete $PID_CB{$pid}{$cb};	1872	delete $PID_CB{$pid}{$icb};
1672	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };	1873	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };
1673		1874
1674	undef $CHLD_W unless keys %PID_CB;	1875	undef $CHLD_W unless keys %PID_CB;
1675	};	1876	};
1676	};	1877	};
…		…
1689		1890
1690	my ($cb, $w, $rcb) = $arg{cb};	1891	my ($cb, $w, $rcb) = $arg{cb};
1691		1892
1692	$rcb = sub {	1893	$rcb = sub {
1693	if ($cb) {	1894	if ($cb) {
1694	$w = _time;	1895	$w = AE::time;
1695	&$cb;	1896	&$cb;
1696	$w = _time - $w;	1897	$w = AE::time - $w;
1697		1898
1698	# never use more then 50% of the time for the idle watcher,	1899	# never use more then 50% of the time for the idle watcher,
1699	# within some limits	1900	# within some limits
1700	$w = 0.0001 if $w < 0.0001;	1901	$w = 0.0001 if $w < 0.0001;
1701	$w = 5 if $w > 5;	1902	$w = 5 if $w > 5;
…		…
1724		1925
1725	package AnyEvent::CondVar;	1926	package AnyEvent::CondVar;
1726		1927
1727	our @ISA = AnyEvent::CondVar::Base::;	1928	our @ISA = AnyEvent::CondVar::Base::;
1728		1929
		1930	# only to be used for subclassing
		1931	sub new {
		1932	my $class = shift;
		1933	bless AnyEvent->condvar (@_), $class
		1934	}
		1935
1729	package AnyEvent::CondVar::Base;	1936	package AnyEvent::CondVar::Base;
1730		1937
1731	#use overload	1938	#use overload
1732	# '&{}' => sub { my $self = shift; sub { $self->send (@_) } },	1939	# '&{}' => sub { my $self = shift; sub { $self->send (@_) } },
1733	# fallback => 1;	1940	# fallback => 1;
…		…
1742		1949
1743	sub _send {	1950	sub _send {
1744	# nop	1951	# nop
1745	}	1952	}
1746		1953
		1954	sub _wait {
		1955	AnyEvent->_poll until $_[0]{_ae_sent};
		1956	}
		1957
1747	sub send {	1958	sub send {
1748	my $cv = shift;	1959	my $cv = shift;
1749	$cv->{_ae_sent} = [@_];	1960	$cv->{_ae_sent} = [@_];
1750	(delete $cv->{_ae_cb})->($cv) if $cv->{_ae_cb};	1961	(delete $cv->{_ae_cb})->($cv) if $cv->{_ae_cb};
1751	$cv->_send;	1962	$cv->_send;
…		…
1758		1969
1759	sub ready {	1970	sub ready {
1760	$_[0]{_ae_sent}	1971	$_[0]{_ae_sent}
1761	}	1972	}
1762		1973
1763	sub _wait {
1764	$WAITING
1765	and !$_[0]{_ae_sent}
1766	and Carp::croak "AnyEvent::CondVar: recursive blocking wait detected";
1767
1768	local $WAITING = 1;
1769	AnyEvent->one_event while !$_[0]{_ae_sent};
1770	}
1771
1772	sub recv {	1974	sub recv {
		1975	unless ($_[0]{_ae_sent}) {
		1976	$WAITING
		1977	and Carp::croak "AnyEvent::CondVar: recursive blocking wait attempted";
		1978
		1979	local $WAITING = 1;
1773	$_[0]->_wait;	1980	$_[0]->_wait;
		1981	}
1774		1982
1775	Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak};	1983	$_[0]{_ae_croak}
1776	wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0]	1984	and Carp::croak $_[0]{_ae_croak};
		1985
		1986	wantarray
		1987	? @{ $_[0]{_ae_sent} }
		1988	: $_[0]{_ae_sent}[0]
1777	}	1989	}
1778		1990
1779	sub cb {	1991	sub cb {
1780	my $cv = shift;	1992	my $cv = shift;
1781		1993
…		…
1797	&{ $_[0]{_ae_end_cb} || sub { $_[0]->send } };	2009	&{ $_[0]{_ae_end_cb} || sub { $_[0]->send } };
1798	}	2010	}
1799		2011
1800	# undocumented/compatibility with pre-3.4	2012	# undocumented/compatibility with pre-3.4
1801	*broadcast = \&send;	2013	*broadcast = \&send;
1802	*wait = \&_wait;	2014	*wait = \&recv;
1803		2015
1804	=head1 ERROR AND EXCEPTION HANDLING	2016	=head1 ERROR AND EXCEPTION HANDLING
1805		2017
1806	In general, AnyEvent does not do any error handling - it relies on the	2018	In general, AnyEvent does not do any error handling - it relies on the
1807	caller to do that if required. The L<AnyEvent::Strict> module (see also	2019	caller to do that if required. The L<AnyEvent::Strict> module (see also
…		…
1819	$Event/EV::DIED->() >>, L<Glib> uses C<< install_exception_handler >> and	2031	$Event/EV::DIED->() >>, L<Glib> uses C<< install_exception_handler >> and
1820	so on.	2032	so on.
1821		2033
1822	=head1 ENVIRONMENT VARIABLES	2034	=head1 ENVIRONMENT VARIABLES
1823		2035
1824	The following environment variables are used by this module or its	2036	AnyEvent supports a number of environment variables that tune the
1825	submodules.	2037	runtime behaviour. They are usually evaluated when AnyEvent is
		2038	loaded, initialised, or a submodule that uses them is loaded. Many of
		2039	them also cause AnyEvent to load additional modules - for example,
		2040	C<PERL_ANYEVENT_DEBUG_WRAP> causes the L<AnyEvent::Debug> module to be
		2041	loaded.
1826		2042
1827	Note that AnyEvent will remove I<all> environment variables starting with	2043	All the environment variables documented here start with
1828	C<PERL_ANYEVENT_> from C<%ENV> when it is loaded while taint mode is	2044	C<PERL_ANYEVENT_>, which is what AnyEvent considers its own
1829	enabled.	2045	namespace. Other modules are encouraged (but by no means required) to use
		2046	C<PERL_ANYEVENT_SUBMODULE> if they have registered the AnyEvent::Submodule
		2047	namespace on CPAN, for any submodule. For example, L<AnyEvent::HTTP> could
		2048	be expected to use C<PERL_ANYEVENT_HTTP_PROXY> (it should not access env
		2049	variables starting with C<AE_>, see below).
		2050
		2051	All variables can also be set via the C<AE_> prefix, that is, instead
		2052	of setting C<PERL_ANYEVENT_VERBOSE> you can also set C<AE_VERBOSE>. In
		2053	case there is a clash btween anyevent and another program that uses
		2054	C<AE_something> you can set the corresponding C<PERL_ANYEVENT_something>
		2055	variable to the empty string, as those variables take precedence.
		2056
		2057	When AnyEvent is first loaded, it copies all C<AE_xxx> env variables
		2058	to their C<PERL_ANYEVENT_xxx> counterpart unless that variable already
		2059	exists. If taint mode is on, then AnyEvent will remove I<all> environment
		2060	variables starting with C<PERL_ANYEVENT_> from C<%ENV> (or replace them
		2061	with C<undef> or the empty string, if the corresaponding C<AE_> variable
		2062	is set).
		2063
		2064	The exact algorithm is currently:
		2065
		2066	1. if taint mode enabled, delete all PERL_ANYEVENT_xyz variables from %ENV
		2067	2. copy over AE_xyz to PERL_ANYEVENT_xyz unless the latter alraedy exists
		2068	3. if taint mode enabled, set all PERL_ANYEVENT_xyz variables to undef.
		2069
		2070	This ensures that child processes will not see the C<AE_> variables.
		2071
		2072	The following environment variables are currently known to AnyEvent:
1830		2073
1831	=over 4	2074	=over 4
1832		2075
1833	=item C<PERL_ANYEVENT_VERBOSE>	2076	=item C<PERL_ANYEVENT_VERBOSE>
1834		2077
1835	By default, AnyEvent will be completely silent except in fatal	2078	By default, AnyEvent will only log messages with loglevel C<3>
1836	conditions. You can set this environment variable to make AnyEvent more	2079	(C<critical>) or higher (see L<AnyEvent::Log>). You can set this
		2080	environment variable to a numerical loglevel to make AnyEvent more (or
1837	talkative.	2081	less) talkative.
1838		2082
		2083	If you want to do more than just set the global logging level
		2084	you should have a look at C<PERL_ANYEVENT_LOG>, which allows much more
		2085	complex specifications.
		2086
		2087	When set to C<0> (C<off>), then no messages whatsoever will be logged with
		2088	the default logging settings.
		2089
1839	When set to C<1> or higher, causes AnyEvent to warn about unexpected	2090	When set to C<5> or higher (C<warn>), causes AnyEvent to warn about
1840	conditions, such as not being able to load the event model specified by	2091	unexpected conditions, such as not being able to load the event model
1841	C<PERL_ANYEVENT_MODEL>.	2092	specified by C<PERL_ANYEVENT_MODEL>, or a guard callback throwing an
		2093	exception - this is the minimum recommended level.
1842		2094
1843	When set to C<2> or higher, cause AnyEvent to report to STDERR which event	2095	When set to C<7> or higher (info), cause AnyEvent to report which event model it
1844	model it chooses.	2096	chooses.
1845		2097
1846	When set to C<8> or higher, then AnyEvent will report extra information on	2098	When set to C<8> or higher (debug), then AnyEvent will report extra information on
1847	which optional modules it loads and how it implements certain features.	2099	which optional modules it loads and how it implements certain features.
		2100
		2101	=item C<PERL_ANYEVENT_LOG>
		2102
		2103	Accepts rather complex logging specifications. For example, you could log
		2104	all C<debug> messages of some module to stderr, warnings and above to
		2105	stderr, and errors and above to syslog, with:
		2106
		2107	PERL_ANYEVENT_LOG=Some::Module=debug,+log:filter=warn,+%syslog:%syslog=error,syslog
		2108
		2109	For the rather extensive details, see L<AnyEvent::Log>.
		2110
		2111	This variable is evaluated when AnyEvent (or L<AnyEvent::Log>) is loaded,
		2112	so will take effect even before AnyEvent has initialised itself.
		2113
		2114	Note that specifying this environment variable causes the L<AnyEvent::Log>
		2115	module to be loaded, while C<PERL_ANYEVENT_VERBOSE> does not, so only
		2116	using the latter saves a few hundred kB of memory until the first message
		2117	is being logged.
1848		2118
1849	=item C<PERL_ANYEVENT_STRICT>	2119	=item C<PERL_ANYEVENT_STRICT>
1850		2120
1851	AnyEvent does not do much argument checking by default, as thorough	2121	AnyEvent does not do much argument checking by default, as thorough
1852	argument checking is very costly. Setting this variable to a true value	2122	argument checking is very costly. Setting this variable to a true value
…		…
1854	check the arguments passed to most method calls. If it finds any problems,	2124	check the arguments passed to most method calls. If it finds any problems,
1855	it will croak.	2125	it will croak.
1856		2126
1857	In other words, enables "strict" mode.	2127	In other words, enables "strict" mode.
1858		2128
1859	Unlike C<use strict> (or it's modern cousin, C<< use L<common::sense>	2129	Unlike C<use strict> (or its modern cousin, C<< use L<common::sense>
1860	>>, it is definitely recommended to keep it off in production. Keeping	2130	>>, it is definitely recommended to keep it off in production. Keeping
1861	C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs	2131	C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs
1862	can be very useful, however.	2132	can be very useful, however.
1863		2133
		2134	=item C<PERL_ANYEVENT_DEBUG_SHELL>
		2135
		2136	If this env variable is nonempty, then its contents will be interpreted by
		2137	C<AnyEvent::Socket::parse_hostport> and C<AnyEvent::Debug::shell> (after
		2138	replacing every occurance of C<$$> by the process pid). The shell object
		2139	is saved in C<$AnyEvent::Debug::SHELL>.
		2140
		2141	This happens when the first watcher is created.
		2142
		2143	For example, to bind a debug shell on a unix domain socket in
		2144	F<< /tmp/debug<pid>.sock >>, you could use this:
		2145
		2146	PERL_ANYEVENT_DEBUG_SHELL=/tmp/debug\$\$.sock perlprog
		2147	# connect with e.g.: socat readline /tmp/debug123.sock
		2148
		2149	Or to bind to tcp port 4545 on localhost:
		2150
		2151	PERL_ANYEVENT_DEBUG_SHELL=127.0.0.1:4545 perlprog
		2152	# connect with e.g.: telnet localhost 4545
		2153
		2154	Note that creating sockets in F</tmp> or on localhost is very unsafe on
		2155	multiuser systems.
		2156
		2157	=item C<PERL_ANYEVENT_DEBUG_WRAP>
		2158
		2159	Can be set to C<0>, C<1> or C<2> and enables wrapping of all watchers for
		2160	debugging purposes. See C<AnyEvent::Debug::wrap> for details.
		2161
1864	=item C<PERL_ANYEVENT_MODEL>	2162	=item C<PERL_ANYEVENT_MODEL>
1865		2163
1866	This can be used to specify the event model to be used by AnyEvent, before	2164	This can be used to specify the event model to be used by AnyEvent, before
1867	auto detection and -probing kicks in. It must be a string consisting	2165	auto detection and -probing kicks in.
1868	entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended	2166
		2167	It normally is a string consisting entirely of ASCII letters (e.g. C<EV>
		2168	or C<IOAsync>). The string C<AnyEvent::Impl::> gets prepended and the
1869	and the resulting module name is loaded and if the load was successful,	2169	resulting module name is loaded and - if the load was successful - used as
1870	used as event model. If it fails to load AnyEvent will proceed with	2170	event model backend. If it fails to load then AnyEvent will proceed with
1871	auto detection and -probing.	2171	auto detection and -probing.
1872		2172
1873	This functionality might change in future versions.	2173	If the string ends with C<::> instead (e.g. C<AnyEvent::Impl::EV::>) then
		2174	nothing gets prepended and the module name is used as-is (hint: C<::> at
		2175	the end of a string designates a module name and quotes it appropriately).
1874		2176
1875	For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you	2177	For example, to force the pure perl model (L<AnyEvent::Loop::Perl>) you
1876	could start your program like this:	2178	could start your program like this:
1877		2179
1878	PERL_ANYEVENT_MODEL=Perl perl ...	2180	PERL_ANYEVENT_MODEL=Perl perl ...
1879		2181
1880	=item C<PERL_ANYEVENT_PROTOCOLS>	2182	=item C<PERL_ANYEVENT_PROTOCOLS>
…		…
1896	but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4>	2198	but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4>
1897	- only support IPv4, never try to resolve or contact IPv6	2199	- only support IPv4, never try to resolve or contact IPv6
1898	addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or	2200	addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or
1899	IPv6, but prefer IPv6 over IPv4.	2201	IPv6, but prefer IPv6 over IPv4.
1900		2202
		2203	=item C<PERL_ANYEVENT_HOSTS>
		2204
		2205	This variable, if specified, overrides the F</etc/hosts> file used by
		2206	L<AnyEvent::Socket>C<::resolve_sockaddr>, i.e. hosts aliases will be read
		2207	from that file instead.
		2208
1901	=item C<PERL_ANYEVENT_EDNS0>	2209	=item C<PERL_ANYEVENT_EDNS0>
1902		2210
1903	Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension	2211	Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension for
1904	for DNS. This extension is generally useful to reduce DNS traffic, but	2212	DNS. This extension is generally useful to reduce DNS traffic, especially
1905	some (broken) firewalls drop such DNS packets, which is why it is off by	2213	when DNSSEC is involved, but some (broken) firewalls drop such DNS
1906	default.	2214	packets, which is why it is off by default.
1907		2215
1908	Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce	2216	Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce
1909	EDNS0 in its DNS requests.	2217	EDNS0 in its DNS requests.
1910		2218
1911	=item C<PERL_ANYEVENT_MAX_FORKS>	2219	=item C<PERL_ANYEVENT_MAX_FORKS>
…		…
1917		2225
1918	The default value for the C<max_outstanding> parameter for the default DNS	2226	The default value for the C<max_outstanding> parameter for the default DNS
1919	resolver - this is the maximum number of parallel DNS requests that are	2227	resolver - this is the maximum number of parallel DNS requests that are
1920	sent to the DNS server.	2228	sent to the DNS server.
1921		2229
		2230	=item C<PERL_ANYEVENT_MAX_SIGNAL_LATENCY>
		2231
		2232	Perl has inherently racy signal handling (you can basically choose between
		2233	losing signals and memory corruption) - pure perl event loops (including
		2234	C<AnyEvent::Loop>, when C<Async::Interrupt> isn't available) therefore
		2235	have to poll regularly to avoid losing signals.
		2236
		2237	Some event loops are racy, but don't poll regularly, and some event loops
		2238	are written in C but are still racy. For those event loops, AnyEvent
		2239	installs a timer that regularly wakes up the event loop.
		2240
		2241	By default, the interval for this timer is C<10> seconds, but you can
		2242	override this delay with this environment variable (or by setting
		2243	the C<$AnyEvent::MAX_SIGNAL_LATENCY> variable before creating signal
		2244	watchers).
		2245
		2246	Lower values increase CPU (and energy) usage, higher values can introduce
		2247	long delays when reaping children or waiting for signals.
		2248
		2249	The L<AnyEvent::Async> module, if available, will be used to avoid this
		2250	polling (with most event loops).
		2251
1922	=item C<PERL_ANYEVENT_RESOLV_CONF>	2252	=item C<PERL_ANYEVENT_RESOLV_CONF>
1923		2253
1924	The file to use instead of F</etc/resolv.conf> (or OS-specific	2254	The absolute path to a F<resolv.conf>-style file to use instead of
1925	configuration) in the default resolver. When set to the empty string, no	2255	F</etc/resolv.conf> (or the OS-specific configuration) in the default
1926	default config will be used.	2256	resolver, or the empty string to select the default configuration.
1927		2257
1928	=item C<PERL_ANYEVENT_CA_FILE>, C<PERL_ANYEVENT_CA_PATH>.	2258	=item C<PERL_ANYEVENT_CA_FILE>, C<PERL_ANYEVENT_CA_PATH>.
1929		2259
1930	When neither C<ca_file> nor C<ca_path> was specified during	2260	When neither C<ca_file> nor C<ca_path> was specified during
1931	L<AnyEvent::TLS> context creation, and either of these environment	2261	L<AnyEvent::TLS> context creation, and either of these environment
1932	variables exist, they will be used to specify CA certificate locations	2262	variables are nonempty, they will be used to specify CA certificate
1933	instead of a system-dependent default.	2263	locations instead of a system-dependent default.
1934		2264
1935	=item C<PERL_ANYEVENT_AVOID_GUARD> and C<PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT>	2265	=item C<PERL_ANYEVENT_AVOID_GUARD> and C<PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT>
1936		2266
1937	When these are set to C<1>, then the respective modules are not	2267	When these are set to C<1>, then the respective modules are not
1938	loaded. Mostly good for testing AnyEvent itself.	2268	loaded. Mostly good for testing AnyEvent itself.
…		…
2270	(even when used without AnyEvent), but most event loops have acceptable	2600	(even when used without AnyEvent), but most event loops have acceptable
2271	performance with or without AnyEvent.	2601	performance with or without AnyEvent.
2272		2602
2273	=item * The overhead AnyEvent adds is usually much smaller than the overhead of	2603	=item * The overhead AnyEvent adds is usually much smaller than the overhead of
2274	the actual event loop, only with extremely fast event loops such as EV	2604	the actual event loop, only with extremely fast event loops such as EV
2275	adds AnyEvent significant overhead.	2605	does AnyEvent add significant overhead.
2276		2606
2277	=item * You should avoid POE like the plague if you want performance or	2607	=item * You should avoid POE like the plague if you want performance or
2278	reasonable memory usage.	2608	reasonable memory usage.
2279		2609
2280	=back	2610	=back
…		…
2510	unless defined $SIG{PIPE};	2840	unless defined $SIG{PIPE};
2511		2841
2512	=head1 RECOMMENDED/OPTIONAL MODULES	2842	=head1 RECOMMENDED/OPTIONAL MODULES
2513		2843
2514	One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and	2844	One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and
2515	it's built-in modules) are required to use it.	2845	its built-in modules) are required to use it.
2516		2846
2517	That does not mean that AnyEvent won't take advantage of some additional	2847	That does not mean that AnyEvent won't take advantage of some additional
2518	modules if they are installed.	2848	modules if they are installed.
2519		2849
2520	This section explains which additional modules will be used, and how they	2850	This section explains which additional modules will be used, and how they
…		…
2578	the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL.	2908	the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL.
2579		2909
2580	=item L<Time::HiRes>	2910	=item L<Time::HiRes>
2581		2911
2582	This module is part of perl since release 5.008. It will be used when the	2912	This module is part of perl since release 5.008. It will be used when the
2583	chosen event library does not come with a timing source on it's own. The	2913	chosen event library does not come with a timing source of its own. The
2584	pure-perl event loop (L<AnyEvent::Impl::Perl>) will additionally use it to	2914	pure-perl event loop (L<AnyEvent::Loop>) will additionally load it to
2585	try to use a monotonic clock for timing stability.	2915	try to use a monotonic clock for timing stability.
2586		2916
2587	=back	2917	=back
2588		2918
2589		2919
…		…
2651	pronounced).	2981	pronounced).
2652		2982
2653		2983
2654	=head1 SEE ALSO	2984	=head1 SEE ALSO
2655		2985
2656	Utility functions: L<AnyEvent::Util>.	2986	Tutorial/Introduction: L<AnyEvent::Intro>.
2657		2987
2658	Event modules: L<EV>, L<EV::Glib>, L<Glib::EV>, L<Event>, L<Glib::Event>,	2988	FAQ: L<AnyEvent::FAQ>.
2659	L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.	2989
		2990	Utility functions: L<AnyEvent::Util> (misc. grab-bag), L<AnyEvent::Log>
		2991	(simply logging).
		2992
		2993	Development/Debugging: L<AnyEvent::Strict> (stricter checking),
		2994	L<AnyEvent::Debug> (interactive shell, watcher tracing).
		2995
		2996	Supported event modules: L<AnyEvent::Loop>, L<EV>, L<EV::Glib>,
		2997	L<Glib::EV>, L<Event>, L<Glib::Event>, L<Glib>, L<Tk>, L<Event::Lib>,
		2998	L<Qt>, L<POE>, L<FLTK>.
2660		2999
2661	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,	3000	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,
2662	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,	3001	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,
2663	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,	3002	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,
2664	L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>, L<Anyevent::Impl::Irssi>.	3003	L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>, L<Anyevent::Impl::Irssi>,
		3004	L<AnyEvent::Impl::FLTK>.
2665		3005
2666	Non-blocking file handles, sockets, TCP clients and	3006	Non-blocking handles, pipes, stream sockets, TCP clients and
2667	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.	3007	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.
2668		3008
2669	Asynchronous DNS: L<AnyEvent::DNS>.	3009	Asynchronous DNS: L<AnyEvent::DNS>.
2670		3010
2671	Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>,	3011	Thread support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>.
2672	L<Coro::Event>,
2673		3012
2674	Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::XMPP>,	3013	Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::IRC>,
2675	L<AnyEvent::HTTP>.	3014	L<AnyEvent::HTTP>.
2676		3015
2677		3016
2678	=head1 AUTHOR	3017	=head1 AUTHOR
2679		3018

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