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Revision 1.404 by root, Sat May 12 23:14:29 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
…		…
138	use AnyEvent;	138	use AnyEvent;
139		139
140	# .. AnyEvent will likely default to Tk	140	# .. AnyEvent will likely default to Tk
141		141
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. Maybe you should tell their authors to	143	starts using it, all bets are off - this case should be very rare though,
144	use AnyEvent so their modules work together with others seamlessly...	144	as very few modules hardcode event loops without announcing this very
		145	loudly.
145		146
146	The pure-perl implementation of AnyEvent is called	147	The pure-perl implementation of AnyEvent is called C<AnyEvent::Loop>. Like
147	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
148	explicitly and enjoy the high availability of that event loop :)	149	availability of that event loop :)
149		150
150	=head1 WATCHERS	151	=head1 WATCHERS
151		152
152	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
153	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
…		…
158	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
159	is in control).	160	is in control).
160		161
161	Note that B<callbacks must not permanently change global variables>	162	Note that B<callbacks must not permanently change global variables>
162	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<<
163	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
164	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
165	widely between event loops.	166	widely between event loops.
166		167
167	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
168	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
169	to it).	170	to it).
170		171
171	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.
172		173
173	Many watchers either are used with "recursion" (repeating timers for	174	Many watchers either are used with "recursion" (repeating timers for
174	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.
175		176
176	An any way to achieve that is this pattern:	177	One way to achieve that is this pattern:
177		178
178	my $w; $w = AnyEvent->type (arg => value ..., cb => sub {	179	my $w; $w = AnyEvent->type (arg => value ..., cb => sub {
179	# you can use $w here, for example to undef it	180	# you can use $w here, for example to undef it
180	undef $w;	181	undef $w;
181	});	182	});
…		…
213		214
214	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.
215	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
216	underlying file descriptor.	217	underlying file descriptor.
217		218
218	Some event loops issue spurious readyness notifications, so you should	219	Some event loops issue spurious readiness notifications, so you should
219	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
220	handles.	221	handles.
221		222
222	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
223	watcher.	224	watcher.
…		…
247		248
248	Although the callback might get passed parameters, their value and	249	Although the callback might get passed parameters, their value and
249	presence is undefined and you cannot rely on them. Portable AnyEvent	250	presence is undefined and you cannot rely on them. Portable AnyEvent
250	callbacks cannot use arguments passed to time watcher callbacks.	251	callbacks cannot use arguments passed to time watcher callbacks.
251		252
252	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
253	parameter, C<interval>, as a strictly positive number (> 0), then the	254	parameter, C<interval>, as a strictly positive number (> 0), then the
254	callback will be invoked regularly at that interval (in fractional	255	callback will be invoked regularly at that interval (in fractional
255	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
256	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.
257		258
258	The callback will be rescheduled before invoking the callback, but no	259	The callback will be rescheduled before invoking the callback, but no
259	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
260	only approximate.	261	only approximate.
261		262
262	Example: fire an event after 7.7 seconds.	263	Example: fire an event after 7.7 seconds.
263		264
264	my $w = AnyEvent->timer (after => 7.7, cb => sub {	265	my $w = AnyEvent->timer (after => 7.7, cb => sub {
…		…
282		283
283	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
284	use absolute time internally. This makes a difference when your clock	285	use absolute time internally. This makes a difference when your clock
285	"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
286	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
287	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.
288		289
289	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
290	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
291	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)
292	timers.	293	timers.
293		294
294	AnyEvent always prefers relative timers, if available, matching the	295	AnyEvent always prefers relative timers, if available, matching the
295	AnyEvent API.	296	AnyEvent API.
…		…
317	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
318	function to call when you want to know the current time.>	319	function to call when you want to know the current time.>
319		320
320	This function is also often faster then C<< AnyEvent->time >>, and	321	This function is also often faster then C<< AnyEvent->time >>, and
321	thus the preferred method if you want some timestamp (for example,	322	thus the preferred method if you want some timestamp (for example,
322	L<AnyEvent::Handle> uses this to update it's activity timeouts).	323	L<AnyEvent::Handle> uses this to update its activity timeouts).
323		324
324	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
325	with your timing, you can skip it without bad conscience.	326	with your timing; you can skip it without a bad conscience.
326		327
327	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>
328	and L<EV> and the following set-up:	329	and L<EV> and the following set-up:
329		330
330	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
331	time=500 (assume no other callbacks delay processing). In your callback,	332	time=500 (assume no other callbacks delay processing). In your callback,
332	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
333	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
334	after three seconds.	335	after three seconds.
335		336
…		…
355	difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into	356	difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into
356	account.	357	account.
357		358
358	=item AnyEvent->now_update	359	=item AnyEvent->now_update
359		360
360	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
361	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 >>,
362	AnyEvent->now >>, above).	363	above).
363		364
364	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
365	this "current" time will differ substantially from the real time, which	366	this "current" time will differ substantially from the real time, which
366	might affect timers and time-outs.	367	might affect timers and time-outs.
367		368
…		…
414	not restart syscalls (that includes L<Async::Interrupt> and AnyEvent's	415	not restart syscalls (that includes L<Async::Interrupt> and AnyEvent's
415	pure perl implementation).	416	pure perl implementation).
416		417
417	=head3 Safe/Unsafe Signals	418	=head3 Safe/Unsafe Signals
418		419
419	Perl signals can be either "safe" (synchronous to opcode handling) or	420	Perl signals can be either "safe" (synchronous to opcode handling)
420	"unsafe" (asynchronous) - the former might get delayed indefinitely, the	421	or "unsafe" (asynchronous) - the former might delay signal delivery
421	latter might corrupt your memory.	422	indefinitely, the latter might corrupt your memory.
422		423
423	AnyEvent signal handlers are, in addition, synchronous to the event loop,	424	AnyEvent signal handlers are, in addition, synchronous to the event loop,
424	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
425	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.
426	callbacks, too).	427	callbacks, too).
427		428
428	=head3 Signal Races, Delays and Workarounds	429	=head3 Signal Races, Delays and Workarounds
429		430
430	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
431	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,
432	do race-free signal handling in perl, requiring C libraries for	433	as you cannot do race-free signal handling in perl, requiring
433	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
434	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
435	specified in C<$AnyEvent::MAX_SIGNAL_LATENCY> (default: 10 seconds). This	436	a signal might be delayed is 10 seconds by default, but can
436	variable can be changed only before the first signal watcher is created,	437	be overriden via C<$ENV{PERL_ANYEVENT_MAX_SIGNAL_LATENCY}> or
437	and should be left alone otherwise. This variable determines how often	438	C<$AnyEvent::MAX_SIGNAL_LATENCY> - see the L<ENVIRONMENT VARIABLES>
438	AnyEvent polls for signals (in case a wake-up was missed). Higher values	439	section for details.
439	will cause fewer spurious wake-ups, which is better for power and CPU
440	saving.
441		440
442	All these problems can be avoided by installing the optional	441	All these problems can be avoided by installing the optional
443	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
444	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>
445	(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
446	one-second latency). For those, you just have to suffer the delays.	445	delays.
447		446
448	=head2 CHILD PROCESS WATCHERS	447	=head2 CHILD PROCESS WATCHERS
449		448
450	$w = AnyEvent->child (pid => <process id>, cb => <callback>);	449	$w = AnyEvent->child (pid => <process id>, cb => <callback>);
451		450
452	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.
453		452
454	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,
455	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
456	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
457	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
458	(stopped/continued).	457	(stopped/continued).
459		458
…		…
481	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
482	watcher before you C<fork> the child (alternatively, you can call	481	watcher before you C<fork> the child (alternatively, you can call
483	C<AnyEvent::detect>).	482	C<AnyEvent::detect>).
484		483
485	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
486	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
487	mentioned in the description of signal watchers apply.	486	problems mentioned in the description of signal watchers apply.
488		487
489	Example: fork a process and wait for it	488	Example: fork a process and wait for it
490		489
491	my $done = AnyEvent->condvar;	490	my $done = AnyEvent->condvar;
492		491
…		…
506		505
507	=head2 IDLE WATCHERS	506	=head2 IDLE WATCHERS
508		507
509	$w = AnyEvent->idle (cb => <callback>);	508	$w = AnyEvent->idle (cb => <callback>);
510		509
511	Repeatedly invoke the callback after the process becomes idle, until	510	This will repeatedly invoke the callback after the process becomes idle,
512	either the watcher is destroyed or new events have been detected.	511	until either the watcher is destroyed or new events have been detected.
513		512
514	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
515	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
516	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
517	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
…		…
556	will actively watch for new events and call your callbacks.	555	will actively watch for new events and call your callbacks.
557		556
558	AnyEvent is slightly different: it expects somebody else to run the event	557	AnyEvent is slightly different: it expects somebody else to run the event
559	loop and will only block when necessary (usually when told by the user).	558	loop and will only block when necessary (usually when told by the user).
560		559
561	The instrument to do that is called a "condition variable", so called	560	The tool to do that is called a "condition variable", so called because
562	because they represent a condition that must become true.	561	they represent a condition that must become true.
563		562
564	Now is probably a good time to look at the examples further below.	563	Now is probably a good time to look at the examples further below.
565		564
566	Condition variables can be created by calling the C<< AnyEvent->condvar	565	Condition variables can be created by calling the C<< AnyEvent->condvar
567	>> method, usually without arguments. The only argument pair allowed is	566	>> method, usually without arguments. The only argument pair allowed is
…		…
572	After creation, the condition variable is "false" until it becomes "true"	571	After creation, the condition variable is "false" until it becomes "true"
573	by calling the C<send> method (or calling the condition variable as if it	572	by calling the C<send> method (or calling the condition variable as if it
574	were a callback, read about the caveats in the description for the C<<	573	were a callback, read about the caveats in the description for the C<<
575	->send >> method).	574	->send >> method).
576		575
577	Condition variables are similar to callbacks, except that you can	576	Since condition variables are the most complex part of the AnyEvent API, here are
578	optionally wait for them. They can also be called merge points - points	577	some different mental models of what they are - pick the ones you can connect to:
579	in time where multiple outstanding events have been processed. And yet	578
580	another way to call them is transactions - each condition variable can be	579	=over 4
581	used to represent a transaction, which finishes at some point and delivers	580
582	a result. And yet some people know them as "futures" - a promise to	581	=item * Condition variables are like callbacks - you can call them (and pass them instead
583	compute/deliver something that you can wait for.	582	of callbacks). Unlike callbacks however, you can also wait for them to be called.
		583
		584	=item * Condition variables are signals - one side can emit or send them,
		585	the other side can wait for them, or install a handler that is called when
		586	the signal fires.
		587
		588	=item * Condition variables are like "Merge Points" - points in your program
		589	where you merge multiple independent results/control flows into one.
		590
		591	=item * Condition variables represent a transaction - functions that start
		592	some kind of transaction can return them, leaving the caller the choice
		593	between waiting in a blocking fashion, or setting a callback.
		594
		595	=item * Condition variables represent future values, or promises to deliver
		596	some result, long before the result is available.
		597
		598	=back
584		599
585	Condition variables are very useful to signal that something has finished,	600	Condition variables are very useful to signal that something has finished,
586	for example, if you write a module that does asynchronous http requests,	601	for example, if you write a module that does asynchronous http requests,
587	then a condition variable would be the ideal candidate to signal the	602	then a condition variable would be the ideal candidate to signal the
588	availability of results. The user can either act when the callback is	603	availability of results. The user can either act when the callback is
…		…
601		616
602	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
603	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
604	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
605	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
606	it's C<new> method in your own C<new> method.	621	its C<new> method in your own C<new> method.
607		622
608	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
609	eventually calls C<< -> send >>, and the "consumer side", which waits	624	eventually calls C<< -> send >>, and the "consumer side", which waits
610	for the send to occur.	625	for the send to occur.
611		626
…		…
676	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
677	C<send>.	692	C<send>.
678		693
679	=item $cv->croak ($error)	694	=item $cv->croak ($error)
680		695
681	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
682	C<Carp::croak> with the given error message/object/scalar.	697	C<Carp::croak> with the given error message/object/scalar.
683		698
684	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
685	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
686	delays the error detetcion, but has the overwhelmign advantage that it	701	delays the error detection, but has the overwhelming advantage that it
687	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
688	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
689	the problem.	704	the problem.
690		705
691	=item $cv->begin ([group callback])	706	=item $cv->begin ([group callback])
692		707
693	=item $cv->end	708	=item $cv->end
…		…
731	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
732	sending.	747	sending.
733		748
734	The ping example mentioned above is slightly more complicated, as the	749	The ping example mentioned above is slightly more complicated, as the
735	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
736	begung can potentially be zero:	751	begun can potentially be zero:
737		752
738	my $cv = AnyEvent->condvar;	753	my $cv = AnyEvent->condvar;
739		754
740	my %result;	755	my %result;
741	$cv->begin (sub { shift->send (\%result) });	756	$cv->begin (sub { shift->send (\%result) });
…		…
762	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
763	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
764	doesn't execute once).	779	doesn't execute once).
765		780
766	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
767	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
768	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
769	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,
770	call C<end>.	785	call C<end>.
771		786
772	=back	787	=back
…		…
779	=over 4	794	=over 4
780		795
781	=item $cv->recv	796	=item $cv->recv
782		797
783	Wait (blocking if necessary) until the C<< ->send >> or C<< ->croak	798	Wait (blocking if necessary) until the C<< ->send >> or C<< ->croak
784	>> methods have been called on c<$cv>, while servicing other watchers	799	>> methods have been called on C<$cv>, while servicing other watchers
785	normally.	800	normally.
786		801
787	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
788	will return immediately.	803	will return immediately.
789		804
…		…
806	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
807	condition variables with some kind of request results and supporting	822	condition variables with some kind of request results and supporting
808	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,
809	while still supporting blocking waits if the caller so desires).	824	while still supporting blocking waits if the caller so desires).
810		825
811	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
812	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
813	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
814	waits otherwise.	829	waits otherwise.
815		830
816	=item $bool = $cv->ready	831	=item $bool = $cv->ready
…		…
821	=item $cb = $cv->cb ($cb->($cv))	836	=item $cb = $cv->cb ($cb->($cv))
822		837
823	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
824	replaces it before doing so.	839	replaces it before doing so.
825		840
826	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
827	"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
828	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
829	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.
830		846
831	=back	847	=back
832		848
833	=head1 SUPPORTED EVENT LOOPS/BACKENDS	849	=head1 SUPPORTED EVENT LOOPS/BACKENDS
834		850
…		…
842	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
843	pure-perl implementation, which is available everywhere as it comes with	859	pure-perl implementation, which is available everywhere as it comes with
844	AnyEvent itself.	860	AnyEvent itself.
845		861
846	AnyEvent::Impl::EV based on EV (interface to libev, best choice).	862	AnyEvent::Impl::EV based on EV (interface to libev, best choice).
847	AnyEvent::Impl::Perl pure-perl implementation, fast and portable.	863	AnyEvent::Impl::Perl pure-perl AnyEvent::Loop, fast and portable.
848		864
849	=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.
850		866
851	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
852	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
853	them. This means that AnyEvent will automatically pick the right backend	869	them. This means that AnyEvent will automatically pick the right backend
854	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
855	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.
856		872
…		…
858	AnyEvent::Impl::Glib based on Glib, slow but very stable.	874	AnyEvent::Impl::Glib based on Glib, slow but very stable.
859	AnyEvent::Impl::Tk based on Tk, very broken.	875	AnyEvent::Impl::Tk based on Tk, very broken.
860	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.	876	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
861	AnyEvent::Impl::POE based on POE, very slow, some limitations.	877	AnyEvent::Impl::POE based on POE, very slow, some limitations.
862	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).
863		882
864	=item Backends with special needs.	883	=item Backends with special needs.
865		884
866	Qt requires the Qt::Application to be instantiated first, but will	885	Qt requires the Qt::Application to be instantiated first, but will
867	otherwise be picked up automatically. As long as the main program	886	otherwise be picked up automatically. As long as the main program
868	instantiates the application before any AnyEvent watchers are created,	887	instantiates the application before any AnyEvent watchers are created,
869	everything should just work.	888	everything should just work.
870		889
871	AnyEvent::Impl::Qt based on Qt.	890	AnyEvent::Impl::Qt based on Qt.
872		891
873	Support for IO::Async can only be partial, as it is too broken and
874	architecturally limited to even support the AnyEvent API. It also
875	is the only event loop that needs the loop to be set explicitly, so
876	it can only be used by a main program knowing about AnyEvent. See
877	L<AnyEvent::Impl::Async> for the gory details.
878
879	AnyEvent::Impl::IOAsync based on IO::Async, cannot be autoprobed.
880
881	=item Event loops that are indirectly supported via other backends.	892	=item Event loops that are indirectly supported via other backends.
882		893
883	Some event loops can be supported via other modules:	894	Some event loops can be supported via other modules:
884		895
885	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>.
…		…
910	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
911	backend has been autodetected.	922	backend has been autodetected.
912		923
913	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
914	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
915	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
916	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
917	will be C<urxvt::anyevent>).	928	will be C<urxvt::anyevent>).
918		929
919	=item AnyEvent::detect	930	=item AnyEvent::detect
920		931
921	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model	932	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model
922	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
923	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
924	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).
925		940
926	If you need to do some initialisation before AnyEvent watchers are	941	If you need to do some initialisation before AnyEvent watchers are
927	created, use C<post_detect>.	942	created, use C<post_detect>.
928		943
929	=item $guard = AnyEvent::post_detect { BLOCK }	944	=item $guard = AnyEvent::post_detect { BLOCK }
930		945
931	Arranges for the code block to be executed as soon as the event model is	946	Arranges for the code block to be executed as soon as the event model is
932	autodetected (or immediately if this has already happened).	947	autodetected (or immediately if that has already happened).
933		948
934	The block will be executed I<after> the actual backend has been detected	949	The block will be executed I<after> the actual backend has been detected
935	(C<$AnyEvent::MODEL> is set), but I<before> any watchers have been	950	(C<$AnyEvent::MODEL> is set), but I<before> any watchers have been
936	created, so it is possible to e.g. patch C<@AnyEvent::ISA> or do	951	created, so it is possible to e.g. patch C<@AnyEvent::ISA> or do
937	other initialisations - see the sources of L<AnyEvent::Strict> or	952	other initialisations - see the sources of L<AnyEvent::Strict> or
…		…
946	that automatically removes the callback again when it is destroyed (or	961	that automatically removes the callback again when it is destroyed (or
947	C<undef> when the hook was immediately executed). See L<AnyEvent::AIO> for	962	C<undef> when the hook was immediately executed). See L<AnyEvent::AIO> for
948	a case where this is useful.	963	a case where this is useful.
949		964
950	Example: Create a watcher for the IO::AIO module and store it in	965	Example: Create a watcher for the IO::AIO module and store it in
951	C<$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.
952		967
953	our WATCHER;	968	our WATCHER;
954		969
955	my $guard = AnyEvent::post_detect {	970	my $guard = AnyEvent::post_detect {
956	$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);
…		…
964	$WATCHER ||= $guard;	979	$WATCHER ||= $guard;
965		980
966	=item @AnyEvent::post_detect	981	=item @AnyEvent::post_detect
967		982
968	If there are any code references in this array (you can C<push> to it	983	If there are any code references in this array (you can C<push> to it
969	before or after loading AnyEvent), then they will called directly after	984	before or after loading AnyEvent), then they will be called directly
970	the event loop has been chosen.	985	after the event loop has been chosen.
971		986
972	You should check C<$AnyEvent::MODEL> before adding to this array, though:	987	You should check C<$AnyEvent::MODEL> before adding to this array, though:
973	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
974	array will be ignored.	989	array will be ignored.
975		990
…		…
992	# AnyEvent not yet initialised, so make sure to load Coro::AnyEvent	1007	# AnyEvent not yet initialised, so make sure to load Coro::AnyEvent
993	# as soon as it is	1008	# as soon as it is
994	push @AnyEvent::post_detect, sub { require Coro::AnyEvent };	1009	push @AnyEvent::post_detect, sub { require Coro::AnyEvent };
995	}	1010	}
996		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
997	=back	1070	=back
998		1071
999	=head1 WHAT TO DO IN A MODULE	1072	=head1 WHAT TO DO IN A MODULE
1000		1073
1001	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
…		…
1011	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
1012	events is to stay interactive.	1085	events is to stay interactive.
1013		1086
1014	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
1015	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
1016	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 >>
1017	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).
1018		1091
1019	=head1 WHAT TO DO IN THE MAIN PROGRAM	1092	=head1 WHAT TO DO IN THE MAIN PROGRAM
1020		1093
1021	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
1022	dictate which event model to use.	1095	dictate which event model to use.
1023		1096
1024	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
1025	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
1026	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.
1027		1102
1028	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
1029	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
1030	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
1031	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
1032	modules might create watchers when they are loaded, and AnyEvent will	1107	modules might create watchers when they are loaded, and AnyEvent will
1033	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
1034	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.
1035		1110
1036	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
1037	C<AnyEvent::Impl::Perl> module, which gives you similar behaviour	1112	C<AnyEvent::Loop> module, which gives you similar behaviour
1038	everywhere, but letting AnyEvent chose the model is generally better.	1113	everywhere, but letting AnyEvent chose the model is generally better.
1039		1114
1040	=head2 MAINLOOP EMULATION	1115	=head2 MAINLOOP EMULATION
1041		1116
1042	Sometimes (often for short test scripts, or even standalone programs who	1117	Sometimes (often for short test scripts, or even standalone programs who
…		…
1055		1130
1056		1131
1057	=head1 OTHER MODULES	1132	=head1 OTHER MODULES
1058		1133
1059	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
1060	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
1061	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
1062	come with AnyEvent, most are available via CPAN.	1137	modules come as part of AnyEvent, the others are available via CPAN (see
		1138	L<http://search.cpan.org/search?m=module&q=anyevent%3A%3A*> for
		1139	a longer non-exhaustive list), and the list is heavily biased towards
		1140	modules of the AnyEvent author himself :)
1063		1141
1064	=over 4	1142	=over 4
1065		1143
1066	=item L<AnyEvent::Util>	1144	=item L<AnyEvent::Util>
1067		1145
1068	Contains various utility functions that replace often-used but blocking	1146	Contains various utility functions that replace often-used blocking
1069	functions such as C<inet_aton> by event-/callback-based versions.	1147	functions such as C<inet_aton> with event/callback-based versions.
1070		1148
1071	=item L<AnyEvent::Socket>	1149	=item L<AnyEvent::Socket>
1072		1150
1073	Provides various utility functions for (internet protocol) sockets,	1151	Provides various utility functions for (internet protocol) sockets,
1074	addresses and name resolution. Also functions to create non-blocking tcp	1152	addresses and name resolution. Also functions to create non-blocking tcp
…		…
1076		1154
1077	=item L<AnyEvent::Handle>	1155	=item L<AnyEvent::Handle>
1078		1156
1079	Provide read and write buffers, manages watchers for reads and writes,	1157	Provide read and write buffers, manages watchers for reads and writes,
1080	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
1081	non-blocking SSL/TLS (via L<AnyEvent::TLS>.	1159	non-blocking SSL/TLS (via L<AnyEvent::TLS>).
1082		1160
1083	=item L<AnyEvent::DNS>	1161	=item L<AnyEvent::DNS>
1084		1162
1085	Provides rich asynchronous DNS resolver capabilities.	1163	Provides rich asynchronous DNS resolver capabilities.
1086		1164
1087	=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>
1088		1166
1089	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
1090	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
1091	Client Protocol).	1169	Client Protocol).
1092
1093	=item L<AnyEvent::Handle::UDP>
1094
1095	Here be danger!
1096
1097	As Pauli would put it, "Not only is it not right, it's not even wrong!" -
1098	there are so many things wrong with AnyEvent::Handle::UDP, most notably
1099	it's use of a stream-based API with a protocol that isn't streamable, that
1100	the only way to improve it is to delete it.
1101
1102	It features data corruption (but typically only under load) and general
1103	confusion. On top, the author is not only clueless about UDP but also
1104	fact-resistant - some gems of his understanding: "connect doesn't work
1105	with UDP", "UDP packets are not IP packets", "UDP only has datagrams, not
1106	packets", "I don't need to implement proper error checking as UDP doesn't
1107	support error checking" and so on - he doesn't even understand what's
1108	wrong with his module when it is explained to him.
1109
1110	=item L<AnyEvent::DBI>
1111
1112	Executes L<DBI> requests asynchronously in a proxy process for you,
1113	notifying you in an event-bnased way when the operation is finished.
1114		1170
1115	=item L<AnyEvent::AIO>	1171	=item L<AnyEvent::AIO>
1116		1172
1117	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
1118	toolbox of every event programmer. AnyEvent::AIO transparently fuses	1174	toolbox of every event programmer. AnyEvent::AIO transparently fuses
1119	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
1120	file I/O, and much more.	1176	file I/O, and much more.
1121		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
1122	=item L<AnyEvent::HTTPD>	1196	=item L<AnyEvent::HTTPD>
1123		1197
1124	A simple embedded webserver.	1198	A simple embedded webserver.
1125		1199
1126	=item L<AnyEvent::FastPing>	1200	=item L<AnyEvent::FastPing>
1127		1201
1128	The fastest ping in the west.	1202	The fastest ping in the west.
1129		1203
1130	=item L<Coro>	1204	=item L<Coro>
1131		1205
1132	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	};
1133		1219
1134	=back	1220	=back
1135		1221
1136	=cut	1222	=cut
1137		1223
1138	package AnyEvent;	1224	package AnyEvent;
1139		1225
1140	# basically a tuned-down version of common::sense	1226	# basically a tuned-down version of common::sense
1141	sub common_sense {	1227	sub common_sense {
1142	# from common:.sense 1.0	1228	# from common:.sense 3.5
		1229	local $^W;
1143	${^WARNING_BITS} = "\xfc\x3f\x33\x00\x0f\xf3\xcf\xc0\xf3\xfc\x33\x00";	1230	${^WARNING_BITS} ^= ${^WARNING_BITS} ^ "\x3c\x3f\x33\x00\x0f\xf0\x0f\xc0\xf0\xfc\x33\x00";
1144	# use strict vars subs - NO UTF-8, as Util.pm doesn't like this atm. (uts46data.pl)	1231	# use strict vars subs - NO UTF-8, as Util.pm doesn't like this atm. (uts46data.pl)
1145	$^H |= 0x00000600;	1232	$^H |= 0x00000600;
1146	}	1233	}
1147		1234
1148	BEGIN { AnyEvent::common_sense }	1235	BEGIN { AnyEvent::common_sense }
1149		1236
1150	use Carp ();	1237	use Carp ();
1151		1238
1152	our $VERSION = '5.261';	1239	our $VERSION = '7.01';
1153	our $MODEL;	1240	our $MODEL;
1154
1155	our $AUTOLOAD;
1156	our @ISA;	1241	our @ISA;
1157
1158	our @REGISTRY;	1242	our @REGISTRY;
1159
1160	our $VERBOSE;	1243	our $VERBOSE;
		1244	our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred
		1245	our $MAX_SIGNAL_LATENCY = $ENV{PERL_ANYEVENT_MAX_SIGNAL_LATENCY} || 10; # executes after the BEGIN block below (tainting!)
1161		1246
1162	BEGIN {	1247	BEGIN {
1163	require "AnyEvent/constants.pl";	1248	require "AnyEvent/constants.pl";
1164		1249
1165	eval "sub TAINT (){" . (${^TAINT}*1) . "}";	1250	eval "sub TAINT (){" . (${^TAINT}*1) . "}";
1166		1251
1167	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}	1252	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}
1168	if ${^TAINT};	1253	if ${^TAINT};
1169		1254
1170	$VERBOSE = $ENV{PERL_ANYEVENT_VERBOSE}*1;	1255	$ENV{"PERL_ANYEVENT_$_"} = $ENV{"AE_$_"}
		1256	for grep s/^AE_// && !exists $ENV{"PERL_ANYEVENT_$_"}, keys %ENV;
1171		1257
1172	}	1258	@ENV{grep /^PERL_ANYEVENT_/, keys %ENV} = ()
		1259	if ${^TAINT};
1173		1260
1174	our $MAX_SIGNAL_LATENCY = 10;	1261	# $ENV{PERL_ANYEVENT_xxx} now valid
1175		1262
1176	our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred	1263	$VERBOSE = length $ENV{PERL_ANYEVENT_VERBOSE} ? $ENV{PERL_ANYEVENT_VERBOSE}*1 : 4;
1177		1264
1178	{
1179	my $idx;	1265	my $idx;
1180	$PROTOCOL{$_} = ++$idx	1266	$PROTOCOL{$_} = ++$idx
1181	for reverse split /\s*,\s*/,	1267	for reverse split /\s*,\s*/,
1182	$ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";	1268	$ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";
1183	}	1269	}
1184		1270
		1271	our @post_detect;
		1272
		1273	sub post_detect(&) {
		1274	my ($cb) = @_;
		1275
		1276	push @post_detect, $cb;
		1277
		1278	defined wantarray
		1279	? bless \$cb, "AnyEvent::Util::postdetect"
		1280	: ()
		1281	}
		1282
		1283	sub AnyEvent::Util::postdetect::DESTROY {
		1284	@post_detect = grep $_ != ${$_[0]}, @post_detect;
		1285	}
		1286
		1287	our $POSTPONE_W;
		1288	our @POSTPONE;
		1289
		1290	sub _postpone_exec {
		1291	undef $POSTPONE_W;
		1292
		1293	&{ shift @POSTPONE }
		1294	while @POSTPONE;
		1295	}
		1296
		1297	sub postpone(&) {
		1298	push @POSTPONE, shift;
		1299
		1300	$POSTPONE_W ||= AE::timer (0, 0, \&_postpone_exec);
		1301
		1302	()
		1303	}
		1304
		1305	sub log($$;@) {
		1306	# only load the big bloated module when we actually are about to log something
		1307	if ($_[0] <= ($VERBOSE || 1)) { # also catches non-numeric levels(!) and fatal
		1308	local ($!, $@);
		1309	require AnyEvent::Log; # among other things, sets $VERBOSE to 9
		1310	# AnyEvent::Log overwrites this function
		1311	goto &log;
		1312	}
		1313
		1314	0 # not logged
		1315	}
		1316
		1317	sub _logger($;$) {
		1318	my ($level, $renabled) = @_;
		1319
		1320	$$renabled = $level <= $VERBOSE;
		1321
		1322	my $logger = [(caller)[0], $level, $renabled];
		1323
		1324	$AnyEvent::Log::LOGGER{$logger+0} = $logger;
		1325
		1326	# return unless defined wantarray;
		1327	#
		1328	# require AnyEvent::Util;
		1329	# my $guard = AnyEvent::Util::guard (sub {
		1330	# # "clean up"
		1331	# delete $LOGGER{$logger+0};
		1332	# });
		1333	#
		1334	# sub {
		1335	# return 0 unless $$renabled;
		1336	#
		1337	# $guard if 0; # keep guard alive, but don't cause runtime overhead
		1338	# require AnyEvent::Log unless $AnyEvent::Log::VERSION;
		1339	# package AnyEvent::Log;
		1340	# _log ($logger->[0], $level, @_) # logger->[0] has been converted at load time
		1341	# }
		1342	}
		1343
		1344	if (length $ENV{PERL_ANYEVENT_LOG}) {
		1345	require AnyEvent::Log; # AnyEvent::Log does the thing for us
		1346	}
		1347
1185	my @models = (	1348	our @models = (
1186	[EV:: => AnyEvent::Impl::EV:: , 1],	1349	[EV:: => AnyEvent::Impl::EV::],
1187	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl:: , 1],	1350	[AnyEvent::Loop:: => AnyEvent::Impl::Perl::],
1188	# everything below here will not (normally) be autoprobed	1351	# everything below here will not (normally) be autoprobed
1189	# as the pureperl backend should work everywhere	1352	# as the pure perl backend should work everywhere
1190	# and is usually faster	1353	# and is usually faster
		1354	[Irssi:: => AnyEvent::Impl::Irssi::], # Irssi has a bogus "Event" package, so msut be near the top
1191	[Event:: => AnyEvent::Impl::Event::, 1],	1355	[Event:: => AnyEvent::Impl::Event::], # slow, stable
1192	[Glib:: => AnyEvent::Impl::Glib:: , 1], # becomes extremely slow with many watchers	1356	[Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers
		1357	# everything below here should not be autoloaded
1193	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy	1358	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
1194	[Irssi:: => AnyEvent::Impl::Irssi::], # Irssi has a bogus "Event" package
1195	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles	1359	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
1196	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program	1360	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program
1197	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza	1361	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
1198	[Wx:: => AnyEvent::Impl::POE::],	1362	[Wx:: => AnyEvent::Impl::POE::],
1199	[Prima:: => AnyEvent::Impl::POE::],	1363	[Prima:: => AnyEvent::Impl::POE::],
1200	# IO::Async is just too broken - we would need workarounds for its	1364	[IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # a bitch to autodetect
1201	# byzantine signal and broken child handling, among others.	1365	[Cocoa::EventLoop:: => AnyEvent::Impl::Cocoa::],
1202	# IO::Async is rather hard to detect, as it doesn't have any	1366	[FLTK:: => AnyEvent::Impl::FLTK::],
1203	# obvious default class.
1204	[IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program
1205	[IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program
1206	[IO::Async::Notifier:: => AnyEvent::Impl::IOAsync::], # requires special main program
1207	[AnyEvent::Impl::IOAsync:: => AnyEvent::Impl::IOAsync::], # requires special main program
1208	);	1367	);
1209		1368
1210	our %method = map +($_ => 1),	1369	our @isa_hook;
		1370
		1371	sub _isa_set {
		1372	my @pkg = ("AnyEvent", (map $_->[0], grep defined, @isa_hook), $MODEL);
		1373
		1374	@{"$pkg[$_-1]::ISA"} = $pkg[$_]
		1375	for 1 .. $#pkg;
		1376
		1377	grep $_ && $_->[1], @isa_hook
		1378	and AE::_reset ();
		1379	}
		1380
		1381	# used for hooking AnyEvent::Strict and AnyEvent::Debug::Wrap into the class hierarchy
		1382	sub _isa_hook($$;$) {
		1383	my ($i, $pkg, $reset_ae) = @_;
		1384
		1385	$isa_hook[$i] = $pkg ? [$pkg, $reset_ae] : undef;
		1386
		1387	_isa_set;
		1388	}
		1389
		1390	# all autoloaded methods reserve the complete glob, not just the method slot.
		1391	# due to bugs in perls method cache implementation.
1211	qw(io timer time now now_update signal child idle condvar one_event DESTROY);	1392	our @methods = qw(io timer time now now_update signal child idle condvar);
1212
1213	our @post_detect;
1214
1215	sub post_detect(&) {
1216	my ($cb) = @_;
1217
1218	push @post_detect, $cb;
1219
1220	defined wantarray
1221	? bless \$cb, "AnyEvent::Util::postdetect"
1222	: ()
1223	}
1224
1225	sub AnyEvent::Util::postdetect::DESTROY {
1226	@post_detect = grep $_ != ${$_[0]}, @post_detect;
1227	}
1228		1393
1229	sub detect() {	1394	sub detect() {
		1395	return $MODEL if $MODEL; # some programs keep references to detect
		1396
		1397	# IO::Async::Loop::AnyEvent is extremely evil, refuse to work with it
		1398	# the author knows about the problems and what it does to AnyEvent as a whole
		1399	# (and the ability of others to use AnyEvent), but simply wants to abuse AnyEvent
		1400	# anyway.
		1401	AnyEvent::log fatal => "IO::Async::Loop::AnyEvent detected - that module is broken by\n"
		1402	. "design, abuses internals and breaks AnyEvent - will not continue."
		1403	if exists $INC{"IO/Async/Loop/AnyEvent.pm"};
		1404
		1405	local $!; # for good measure
		1406	local $SIG{__DIE__}; # we use eval
		1407
1230	# free some memory	1408	# free some memory
1231	*detect = sub () { $MODEL };	1409	*detect = sub () { $MODEL };
		1410	# undef &func doesn't correctly update the method cache. grmbl.
		1411	# so we delete the whole glob. grmbl.
		1412	# otoh, perl doesn't let me undef an active usb, but it lets me free
		1413	# a glob with an active sub. hrm. i hope it works, but perl is
		1414	# usually buggy in this department. sigh.
		1415	delete @{"AnyEvent::"}{@methods};
		1416	undef @methods;
1232		1417
1233	local $!; # for good measure
1234	local $SIG{__DIE__};
1235
1236	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {	1418	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z0-9:]+)$/) {
1237	my $model = "AnyEvent::Impl::$1";	1419	my $model = $1;
		1420	$model = "AnyEvent::Impl::$model" unless $model =~ s/::$//;
1238	if (eval "require $model") {	1421	if (eval "require $model") {
		1422	AnyEvent::log 7 => "Loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.";
1239	$MODEL = $model;	1423	$MODEL = $model;
1240	warn "AnyEvent: loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.\n" if $VERBOSE >= 2;
1241	} else {	1424	} else {
1242	warn "AnyEvent: unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@" if $VERBOSE;	1425	AnyEvent::log 4 => "Unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@";
1243	}	1426	}
1244	}	1427	}
1245		1428
1246	# check for already loaded models	1429	# check for already loaded models
1247	unless ($MODEL) {	1430	unless ($MODEL) {
1248	for (@REGISTRY, @models) {	1431	for (@REGISTRY, @models) {
1249	my ($package, $model) = @$_;	1432	my ($package, $model) = @$_;
1250	if (${"$package\::VERSION"} > 0) {	1433	if (${"$package\::VERSION"} > 0) {
1251	if (eval "require $model") {	1434	if (eval "require $model") {
		1435	AnyEvent::log 7 => "Autodetected model '$model', using it.";
1252	$MODEL = $model;	1436	$MODEL = $model;
1253	warn "AnyEvent: autodetected model '$model', using it.\n" if $VERBOSE >= 2;	1437	last;
		1438	} else {
		1439	AnyEvent::log 8 => "Detected event loop $package, but cannot load '$model', skipping: $@";
		1440	}
		1441	}
		1442	}
		1443
		1444	unless ($MODEL) {
		1445	# try to autoload a model
		1446	for (@REGISTRY, @models) {
		1447	my ($package, $model) = @$_;
		1448	if (
		1449	eval "require $package"
		1450	and ${"$package\::VERSION"} > 0
		1451	and eval "require $model"
		1452	) {
		1453	AnyEvent::log 7 => "Autoloaded model '$model', using it.";
		1454	$MODEL = $model;
1254	last;	1455	last;
1255	}	1456	}
1256	}	1457	}
1257	}
1258
1259	unless ($MODEL) {
1260	# try to autoload a model
1261	for (@REGISTRY, @models) {
1262	my ($package, $model, $autoload) = @$_;
1263	if (
1264	$autoload
1265	and eval "require $package"
1266	and ${"$package\::VERSION"} > 0
1267	and eval "require $model"
1268	) {
1269	$MODEL = $model;
1270	warn "AnyEvent: autoloaded model '$model', using it.\n" if $VERBOSE >= 2;
1271	last;
1272	}
1273	}
1274		1458
1275	$MODEL	1459	$MODEL
1276	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.\n";	1460	or AnyEvent::log fatal => "Backend autodetection failed - did you properly install AnyEvent?";
1277	}	1461	}
1278	}	1462	}
1279		1463
1280	@models = (); # free probe data	1464	# free memory only needed for probing
		1465	undef @models;
		1466	undef @REGISTRY;
1281		1467
1282	push @{"$MODEL\::ISA"}, "AnyEvent::Base";	1468	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
1283	unshift @ISA, $MODEL;
1284		1469
1285	# now nuke some methods that are overriden by the backend.	1470	# now nuke some methods that are overridden by the backend.
1286	# SUPER is not allowed.	1471	# SUPER usage is not allowed in these.
1287	for (qw(time signal child idle)) {	1472	for (qw(time signal child idle)) {
1288	undef &{"AnyEvent::Base::$_"}	1473	undef &{"AnyEvent::Base::$_"}
1289	if defined &{"$MODEL\::$_"};	1474	if defined &{"$MODEL\::$_"};
1290	}	1475	}
1291		1476
1292	require AnyEvent::Strict if $ENV{PERL_ANYEVENT_STRICT};	1477	_isa_set;
		1478
		1479	# we're officially open!
		1480
		1481	if ($ENV{PERL_ANYEVENT_STRICT}) {
		1482	require AnyEvent::Strict;
		1483	}
		1484
		1485	if ($ENV{PERL_ANYEVENT_DEBUG_WRAP}) {
		1486	require AnyEvent::Debug;
		1487	AnyEvent::Debug::wrap ($ENV{PERL_ANYEVENT_DEBUG_WRAP});
		1488	}
		1489
		1490	if (length $ENV{PERL_ANYEVENT_DEBUG_SHELL}) {
		1491	require AnyEvent::Socket;
		1492	require AnyEvent::Debug;
		1493
		1494	my $shell = $ENV{PERL_ANYEVENT_DEBUG_SHELL};
		1495	$shell =~ s/\$\$/$$/g;
		1496
		1497	my ($host, $service) = AnyEvent::Socket::parse_hostport ($shell);
		1498	$AnyEvent::Debug::SHELL = AnyEvent::Debug::shell ($host, $service);
		1499	}
		1500
		1501	# now the anyevent environment is set up as the user told us to, so
		1502	# call the actual user code - post detects
1293		1503
1294	(shift @post_detect)->() while @post_detect;	1504	(shift @post_detect)->() while @post_detect;
		1505	undef @post_detect;
1295		1506
1296	*post_detect = sub(&) {	1507	*post_detect = sub(&) {
1297	shift->();	1508	shift->();
1298		1509
1299	undef	1510	undef
1300	};	1511	};
1301		1512
1302	$MODEL	1513	$MODEL
1303	}	1514	}
1304		1515
1305	sub AUTOLOAD {	1516	for my $name (@methods) {
1306	(my $func = $AUTOLOAD) =~ s/.*://;	1517	*$name = sub {
1307
1308	$method{$func}
1309	or Carp::croak "$func: not a valid AnyEvent class method";
1310
1311	detect;	1518	detect;
1312		1519	# we use goto because
1313	my $class = shift;	1520	# a) it makes the thunk more transparent
1314	$class->$func (@_);	1521	# b) it allows us to delete the thunk later
		1522	goto &{ UNIVERSAL::can AnyEvent => "SUPER::$name" }
		1523	};
1315	}	1524	}
1316		1525
1317	# utility function to dup a filehandle. this is used by many backends	1526	# utility function to dup a filehandle. this is used by many backends
1318	# to support binding more than one watcher per filehandle (they usually	1527	# to support binding more than one watcher per filehandle (they usually
1319	# allow only one watcher per fd, so we dup it to get a different one).	1528	# allow only one watcher per fd, so we dup it to get a different one).
…		…
1343		1552
1344	package AE;	1553	package AE;
1345		1554
1346	our $VERSION = $AnyEvent::VERSION;	1555	our $VERSION = $AnyEvent::VERSION;
1347		1556
		1557	sub _reset() {
		1558	eval q{
1348	# fall back to the main API by default - backends and AnyEvent::Base	1559	# fall back to the main API by default - backends and AnyEvent::Base
1349	# implementations can overwrite these.	1560	# implementations can overwrite these.
1350		1561
1351	sub io($$$) {	1562	sub io($$$) {
1352	AnyEvent->io (fh => $_[0], poll => $_[1] ? "w" : "r", cb => $_[2])	1563	AnyEvent->io (fh => $_[0], poll => $_[1] ? "w" : "r", cb => $_[2])
1353	}	1564	}
1354		1565
1355	sub timer($$$) {	1566	sub timer($$$) {
1356	AnyEvent->timer (after => $_[0], interval => $_[1], cb => $_[2])	1567	AnyEvent->timer (after => $_[0], interval => $_[1], cb => $_[2])
1357	}	1568	}
1358		1569
1359	sub signal($$) {	1570	sub signal($$) {
1360	AnyEvent->signal (signal => $_[0], cb => $_[1])	1571	AnyEvent->signal (signal => $_[0], cb => $_[1])
1361	}	1572	}
1362		1573
1363	sub child($$) {	1574	sub child($$) {
1364	AnyEvent->child (pid => $_[0], cb => $_[1])	1575	AnyEvent->child (pid => $_[0], cb => $_[1])
1365	}	1576	}
1366		1577
1367	sub idle($) {	1578	sub idle($) {
1368	AnyEvent->idle (cb => $_[0])	1579	AnyEvent->idle (cb => $_[0]);
1369	}	1580	}
1370		1581
1371	sub cv(;&) {	1582	sub cv(;&) {
1372	AnyEvent->condvar (@_ ? (cb => $_[0]) : ())	1583	AnyEvent->condvar (@_ ? (cb => $_[0]) : ())
1373	}	1584	}
1374		1585
1375	sub now() {	1586	sub now() {
1376	AnyEvent->now	1587	AnyEvent->now
1377	}	1588	}
1378		1589
1379	sub now_update() {	1590	sub now_update() {
1380	AnyEvent->now_update	1591	AnyEvent->now_update
1381	}	1592	}
1382		1593
1383	sub time() {	1594	sub time() {
1384	AnyEvent->time	1595	AnyEvent->time
		1596	}
		1597
		1598	*postpone = \&AnyEvent::postpone;
		1599	*log = \&AnyEvent::log;
		1600	};
		1601	die if $@;
1385	}	1602	}
		1603
		1604	BEGIN { _reset }
1386		1605
1387	package AnyEvent::Base;	1606	package AnyEvent::Base;
1388		1607
1389	# default implementations for many methods	1608	# default implementations for many methods
1390		1609
1391	sub time {	1610	sub time {
1392	eval q{ # poor man's autoloading {}	1611	eval q{ # poor man's autoloading {}
1393	# probe for availability of Time::HiRes	1612	# probe for availability of Time::HiRes
1394	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {	1613	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {
1395	warn "AnyEvent: using Time::HiRes for sub-second timing accuracy.\n" if $VERBOSE >= 8;	1614	*time = sub { Time::HiRes::time () };
1396	*AE::time = \&Time::HiRes::time;	1615	*AE::time = \& Time::HiRes::time ;
		1616	*now = \&time;
		1617	AnyEvent::log 8 => "using Time::HiRes for sub-second timing accuracy.";
1397	# if (eval "use POSIX (); (POSIX::times())...	1618	# if (eval "use POSIX (); (POSIX::times())...
1398	} else {	1619	} else {
1399	warn "AnyEvent: using built-in time(), WARNING, no sub-second resolution!\n" if $VERBOSE;	1620	*time = sub { CORE::time };
1400	*AE::time = sub (){ time }; # epic fail	1621	*AE::time = sub (){ CORE::time };
		1622	*now = \&time;
		1623	AnyEvent::log 3 => "Using built-in time(), no sub-second resolution!";
1401	}	1624	}
1402
1403	*time = sub { AE::time }; # different prototypes
1404	};	1625	};
1405	die if $@;	1626	die if $@;
1406		1627
1407	&time	1628	&time
1408	}	1629	}
1409		1630
1410	*now = \&time;	1631	*now = \&time;
1411
1412	sub now_update { }	1632	sub now_update { }
1413		1633
		1634	sub _poll {
		1635	Carp::croak "$AnyEvent::MODEL does not support blocking waits. Caught";
		1636	}
		1637
1414	# default implementation for ->condvar	1638	# default implementation for ->condvar
		1639	# in fact, the default should not be overwritten
1415		1640
1416	sub condvar {	1641	sub condvar {
1417	eval q{ # poor man's autoloading {}	1642	eval q{ # poor man's autoloading {}
1418	*condvar = sub {	1643	*condvar = sub {
1419	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"	1644	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"
…		…
1497		1722
1498	sub signal {	1723	sub signal {
1499	eval q{ # poor man's autoloading {}	1724	eval q{ # poor man's autoloading {}
1500	# probe for availability of Async::Interrupt	1725	# probe for availability of Async::Interrupt
1501	if (_have_async_interrupt) {	1726	if (_have_async_interrupt) {
1502	warn "AnyEvent: using Async::Interrupt for race-free signal handling.\n" if $VERBOSE >= 8;	1727	AnyEvent::log 8 => "Using Async::Interrupt for race-free signal handling.";
1503		1728
1504	$SIGPIPE_R = new Async::Interrupt::EventPipe;	1729	$SIGPIPE_R = new Async::Interrupt::EventPipe;
1505	$SIG_IO = AE::io $SIGPIPE_R->fileno, 0, \&_signal_exec;	1730	$SIG_IO = AE::io $SIGPIPE_R->fileno, 0, \&_signal_exec;
1506		1731
1507	} else {	1732	} else {
1508	warn "AnyEvent: using emulated perl signal handling with latency timer.\n" if $VERBOSE >= 8;	1733	AnyEvent::log 8 => "Using emulated perl signal handling with latency timer.";
1509		1734
1510	if (AnyEvent::WIN32) {	1735	if (AnyEvent::WIN32) {
1511	require AnyEvent::Util;	1736	require AnyEvent::Util;
1512		1737
1513	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();	1738	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
…		…
1589	: sysread $SIGPIPE_R, (my $dummy), 9;	1814	: sysread $SIGPIPE_R, (my $dummy), 9;
1590		1815
1591	while (%SIG_EV) {	1816	while (%SIG_EV) {
1592	for (keys %SIG_EV) {	1817	for (keys %SIG_EV) {
1593	delete $SIG_EV{$_};	1818	delete $SIG_EV{$_};
1594	$_->() for values %{ $SIG_CB{$_} || {} };	1819	&$_ for values %{ $SIG_CB{$_} || {} };
1595	}	1820	}
1596	}	1821	}
1597	};	1822	};
1598	};	1823	};
1599	die if $@;	1824	die if $@;
…		…
1604	# default implementation for ->child	1829	# default implementation for ->child
1605		1830
1606	our %PID_CB;	1831	our %PID_CB;
1607	our $CHLD_W;	1832	our $CHLD_W;
1608	our $CHLD_DELAY_W;	1833	our $CHLD_DELAY_W;
1609	our $WNOHANG;
1610		1834
1611	# used by many Impl's	1835	# used by many Impl's
1612	sub _emit_childstatus($$) {	1836	sub _emit_childstatus($$) {
1613	my (undef, $rpid, $rstatus) = @_;	1837	my (undef, $rpid, $rstatus) = @_;
1614		1838
…		…
1621	eval q{ # poor man's autoloading {}	1845	eval q{ # poor man's autoloading {}
1622	*_sigchld = sub {	1846	*_sigchld = sub {
1623	my $pid;	1847	my $pid;
1624		1848
1625	AnyEvent->_emit_childstatus ($pid, $?)	1849	AnyEvent->_emit_childstatus ($pid, $?)
1626	while ($pid = waitpid -1, $WNOHANG) > 0;	1850	while ($pid = waitpid -1, WNOHANG) > 0;
1627	};	1851	};
1628		1852
1629	*child = sub {	1853	*child = sub {
1630	my (undef, %arg) = @_;	1854	my (undef, %arg) = @_;
1631		1855
1632	defined (my $pid = $arg{pid} + 0)	1856	my $pid = $arg{pid};
1633	or Carp::croak "required option 'pid' is missing";	1857	my $cb = $arg{cb};
1634		1858
1635	$PID_CB{$pid}{$arg{cb}} = $arg{cb};	1859	$PID_CB{$pid}{$cb+0} = $cb;
1636
1637	# WNOHANG is almost cetrainly 1 everywhere
1638	$WNOHANG ||= $^O =~ /^(?:openbsd|netbsd|linux|freebsd|cygwin|MSWin32)$/
1639	? 1
1640	: eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1;
1641		1860
1642	unless ($CHLD_W) {	1861	unless ($CHLD_W) {
1643	$CHLD_W = AE::signal CHLD => \&_sigchld;	1862	$CHLD_W = AE::signal CHLD => \&_sigchld;
1644	# child could be a zombie already, so make at least one round	1863	# child could be a zombie already, so make at least one round
1645	&_sigchld;	1864	&_sigchld;
1646	}	1865	}
1647		1866
1648	bless [$pid, $arg{cb}], "AnyEvent::Base::child"	1867	bless [$pid, $cb+0], "AnyEvent::Base::child"
1649	};	1868	};
1650		1869
1651	*AnyEvent::Base::child::DESTROY = sub {	1870	*AnyEvent::Base::child::DESTROY = sub {
1652	my ($pid, $cb) = @{$_[0]};	1871	my ($pid, $icb) = @{$_[0]};
1653		1872
1654	delete $PID_CB{$pid}{$cb};	1873	delete $PID_CB{$pid}{$icb};
1655	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };	1874	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };
1656		1875
1657	undef $CHLD_W unless keys %PID_CB;	1876	undef $CHLD_W unless keys %PID_CB;
1658	};	1877	};
1659	};	1878	};
…		…
1672		1891
1673	my ($cb, $w, $rcb) = $arg{cb};	1892	my ($cb, $w, $rcb) = $arg{cb};
1674		1893
1675	$rcb = sub {	1894	$rcb = sub {
1676	if ($cb) {	1895	if ($cb) {
1677	$w = _time;	1896	$w = AE::time;
1678	&$cb;	1897	&$cb;
1679	$w = _time - $w;	1898	$w = AE::time - $w;
1680		1899
1681	# never use more then 50% of the time for the idle watcher,	1900	# never use more then 50% of the time for the idle watcher,
1682	# within some limits	1901	# within some limits
1683	$w = 0.0001 if $w < 0.0001;	1902	$w = 0.0001 if $w < 0.0001;
1684	$w = 5 if $w > 5;	1903	$w = 5 if $w > 5;
…		…
1707		1926
1708	package AnyEvent::CondVar;	1927	package AnyEvent::CondVar;
1709		1928
1710	our @ISA = AnyEvent::CondVar::Base::;	1929	our @ISA = AnyEvent::CondVar::Base::;
1711		1930
		1931	# only to be used for subclassing
		1932	sub new {
		1933	my $class = shift;
		1934	bless AnyEvent->condvar (@_), $class
		1935	}
		1936
1712	package AnyEvent::CondVar::Base;	1937	package AnyEvent::CondVar::Base;
1713		1938
1714	#use overload	1939	#use overload
1715	# '&{}' => sub { my $self = shift; sub { $self->send (@_) } },	1940	# '&{}' => sub { my $self = shift; sub { $self->send (@_) } },
1716	# fallback => 1;	1941	# fallback => 1;
…		…
1725		1950
1726	sub _send {	1951	sub _send {
1727	# nop	1952	# nop
1728	}	1953	}
1729		1954
		1955	sub _wait {
		1956	AnyEvent->_poll until $_[0]{_ae_sent};
		1957	}
		1958
1730	sub send {	1959	sub send {
1731	my $cv = shift;	1960	my $cv = shift;
1732	$cv->{_ae_sent} = [@_];	1961	$cv->{_ae_sent} = [@_];
1733	(delete $cv->{_ae_cb})->($cv) if $cv->{_ae_cb};	1962	(delete $cv->{_ae_cb})->($cv) if $cv->{_ae_cb};
1734	$cv->_send;	1963	$cv->_send;
…		…
1741		1970
1742	sub ready {	1971	sub ready {
1743	$_[0]{_ae_sent}	1972	$_[0]{_ae_sent}
1744	}	1973	}
1745		1974
1746	sub _wait {
1747	$WAITING
1748	and !$_[0]{_ae_sent}
1749	and Carp::croak "AnyEvent::CondVar: recursive blocking wait detected";
1750
1751	local $WAITING = 1;
1752	AnyEvent->one_event while !$_[0]{_ae_sent};
1753	}
1754
1755	sub recv {	1975	sub recv {
		1976	unless ($_[0]{_ae_sent}) {
		1977	$WAITING
		1978	and Carp::croak "AnyEvent::CondVar: recursive blocking wait attempted";
		1979
		1980	local $WAITING = 1;
1756	$_[0]->_wait;	1981	$_[0]->_wait;
		1982	}
1757		1983
1758	Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak};	1984	$_[0]{_ae_croak}
1759	wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0]	1985	and Carp::croak $_[0]{_ae_croak};
		1986
		1987	wantarray
		1988	? @{ $_[0]{_ae_sent} }
		1989	: $_[0]{_ae_sent}[0]
1760	}	1990	}
1761		1991
1762	sub cb {	1992	sub cb {
1763	my $cv = shift;	1993	my $cv = shift;
1764		1994
…		…
1780	&{ $_[0]{_ae_end_cb} || sub { $_[0]->send } };	2010	&{ $_[0]{_ae_end_cb} || sub { $_[0]->send } };
1781	}	2011	}
1782		2012
1783	# undocumented/compatibility with pre-3.4	2013	# undocumented/compatibility with pre-3.4
1784	*broadcast = \&send;	2014	*broadcast = \&send;
1785	*wait = \&_wait;	2015	*wait = \&recv;
1786		2016
1787	=head1 ERROR AND EXCEPTION HANDLING	2017	=head1 ERROR AND EXCEPTION HANDLING
1788		2018
1789	In general, AnyEvent does not do any error handling - it relies on the	2019	In general, AnyEvent does not do any error handling - it relies on the
1790	caller to do that if required. The L<AnyEvent::Strict> module (see also	2020	caller to do that if required. The L<AnyEvent::Strict> module (see also
…		…
1802	$Event/EV::DIED->() >>, L<Glib> uses C<< install_exception_handler >> and	2032	$Event/EV::DIED->() >>, L<Glib> uses C<< install_exception_handler >> and
1803	so on.	2033	so on.
1804		2034
1805	=head1 ENVIRONMENT VARIABLES	2035	=head1 ENVIRONMENT VARIABLES
1806		2036
1807	The following environment variables are used by this module or its	2037	AnyEvent supports a number of environment variables that tune the
1808	submodules.	2038	runtime behaviour. They are usually evaluated when AnyEvent is
		2039	loaded, initialised, or a submodule that uses them is loaded. Many of
		2040	them also cause AnyEvent to load additional modules - for example,
		2041	C<PERL_ANYEVENT_DEBUG_WRAP> causes the L<AnyEvent::Debug> module to be
		2042	loaded.
1809		2043
1810	Note that AnyEvent will remove I<all> environment variables starting with	2044	All the environment variables documented here start with
1811	C<PERL_ANYEVENT_> from C<%ENV> when it is loaded while taint mode is	2045	C<PERL_ANYEVENT_>, which is what AnyEvent considers its own
1812	enabled.	2046	namespace. Other modules are encouraged (but by no means required) to use
		2047	C<PERL_ANYEVENT_SUBMODULE> if they have registered the AnyEvent::Submodule
		2048	namespace on CPAN, for any submodule. For example, L<AnyEvent::HTTP> could
		2049	be expected to use C<PERL_ANYEVENT_HTTP_PROXY> (it should not access env
		2050	variables starting with C<AE_>, see below).
		2051
		2052	All variables can also be set via the C<AE_> prefix, that is, instead
		2053	of setting C<PERL_ANYEVENT_VERBOSE> you can also set C<AE_VERBOSE>. In
		2054	case there is a clash btween anyevent and another program that uses
		2055	C<AE_something> you can set the corresponding C<PERL_ANYEVENT_something>
		2056	variable to the empty string, as those variables take precedence.
		2057
		2058	When AnyEvent is first loaded, it copies all C<AE_xxx> env variables
		2059	to their C<PERL_ANYEVENT_xxx> counterpart unless that variable already
		2060	exists. If taint mode is on, then AnyEvent will remove I<all> environment
		2061	variables starting with C<PERL_ANYEVENT_> from C<%ENV> (or replace them
		2062	with C<undef> or the empty string, if the corresaponding C<AE_> variable
		2063	is set).
		2064
		2065	The exact algorithm is currently:
		2066
		2067	1. if taint mode enabled, delete all PERL_ANYEVENT_xyz variables from %ENV
		2068	2. copy over AE_xyz to PERL_ANYEVENT_xyz unless the latter alraedy exists
		2069	3. if taint mode enabled, set all PERL_ANYEVENT_xyz variables to undef.
		2070
		2071	This ensures that child processes will not see the C<AE_> variables.
		2072
		2073	The following environment variables are currently known to AnyEvent:
1813		2074
1814	=over 4	2075	=over 4
1815		2076
1816	=item C<PERL_ANYEVENT_VERBOSE>	2077	=item C<PERL_ANYEVENT_VERBOSE>
1817		2078
1818	By default, AnyEvent will be completely silent except in fatal	2079	By default, AnyEvent will log messages with loglevel C<4> (C<error>) or
1819	conditions. You can set this environment variable to make AnyEvent more	2080	higher (see L<AnyEvent::Log>). You can set this environment variable to a
1820	talkative.	2081	numerical loglevel to make AnyEvent more (or less) talkative.
1821		2082
		2083	If you want to do more than just set the global logging level
		2084	you should have a look at C<PERL_ANYEVENT_LOG>, which allows much more
		2085	complex specifications.
		2086
		2087	When set to C<0> (C<off>), then no messages whatsoever will be logged with
		2088	everything else at defaults.
		2089
1822	When set to C<1> or higher, causes AnyEvent to warn about unexpected	2090	When set to C<5> or higher (C<warn>), AnyEvent warns about unexpected
1823	conditions, such as not being able to load the event model specified by	2091	conditions, such as not being able to load the event model specified by
1824	C<PERL_ANYEVENT_MODEL>.	2092	C<PERL_ANYEVENT_MODEL>, or a guard callback throwing an exception - this
		2093	is the minimum recommended level for use during development.
1825		2094
1826	When set to C<2> or higher, cause AnyEvent to report to STDERR which event	2095	When set to C<7> or higher (info), AnyEvent reports which event model it
1827	model it chooses.	2096	chooses.
1828		2097
1829	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
1830	which optional modules it loads and how it implements certain features.	2099	information on which optional modules it loads and how it implements
		2100	certain features.
		2101
		2102	=item C<PERL_ANYEVENT_LOG>
		2103
		2104	Accepts rather complex logging specifications. For example, you could log
		2105	all C<debug> messages of some module to stderr, warnings and above to
		2106	stderr, and errors and above to syslog, with:
		2107
		2108	PERL_ANYEVENT_LOG=Some::Module=debug,+log:filter=warn,+%syslog:%syslog=error,syslog
		2109
		2110	For the rather extensive details, see L<AnyEvent::Log>.
		2111
		2112	This variable is evaluated when AnyEvent (or L<AnyEvent::Log>) is loaded,
		2113	so will take effect even before AnyEvent has initialised itself.
		2114
		2115	Note that specifying this environment variable causes the L<AnyEvent::Log>
		2116	module to be loaded, while C<PERL_ANYEVENT_VERBOSE> does not, so only
		2117	using the latter saves a few hundred kB of memory unless a module
		2118	explicitly needs the extra features of AnyEvent::Log.
1831		2119
1832	=item C<PERL_ANYEVENT_STRICT>	2120	=item C<PERL_ANYEVENT_STRICT>
1833		2121
1834	AnyEvent does not do much argument checking by default, as thorough	2122	AnyEvent does not do much argument checking by default, as thorough
1835	argument checking is very costly. Setting this variable to a true value	2123	argument checking is very costly. Setting this variable to a true value
…		…
1837	check the arguments passed to most method calls. If it finds any problems,	2125	check the arguments passed to most method calls. If it finds any problems,
1838	it will croak.	2126	it will croak.
1839		2127
1840	In other words, enables "strict" mode.	2128	In other words, enables "strict" mode.
1841		2129
1842	Unlike C<use strict> (or it's modern cousin, C<< use L<common::sense>	2130	Unlike C<use strict> (or its modern cousin, C<< use L<common::sense>
1843	>>, it is definitely recommended to keep it off in production. Keeping	2131	>>, it is definitely recommended to keep it off in production. Keeping
1844	C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs	2132	C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs
1845	can be very useful, however.	2133	can be very useful, however.
1846		2134
		2135	=item C<PERL_ANYEVENT_DEBUG_SHELL>
		2136
		2137	If this env variable is nonempty, then its contents will be interpreted by
		2138	C<AnyEvent::Socket::parse_hostport> and C<AnyEvent::Debug::shell> (after
		2139	replacing every occurance of C<$$> by the process pid). The shell object
		2140	is saved in C<$AnyEvent::Debug::SHELL>.
		2141
		2142	This happens when the first watcher is created.
		2143
		2144	For example, to bind a debug shell on a unix domain socket in
		2145	F<< /tmp/debug<pid>.sock >>, you could use this:
		2146
		2147	PERL_ANYEVENT_DEBUG_SHELL=/tmp/debug\$\$.sock perlprog
		2148	# connect with e.g.: socat readline /tmp/debug123.sock
		2149
		2150	Or to bind to tcp port 4545 on localhost:
		2151
		2152	PERL_ANYEVENT_DEBUG_SHELL=127.0.0.1:4545 perlprog
		2153	# connect with e.g.: telnet localhost 4545
		2154
		2155	Note that creating sockets in F</tmp> or on localhost is very unsafe on
		2156	multiuser systems.
		2157
		2158	=item C<PERL_ANYEVENT_DEBUG_WRAP>
		2159
		2160	Can be set to C<0>, C<1> or C<2> and enables wrapping of all watchers for
		2161	debugging purposes. See C<AnyEvent::Debug::wrap> for details.
		2162
1847	=item C<PERL_ANYEVENT_MODEL>	2163	=item C<PERL_ANYEVENT_MODEL>
1848		2164
1849	This can be used to specify the event model to be used by AnyEvent, before	2165	This can be used to specify the event model to be used by AnyEvent, before
1850	auto detection and -probing kicks in. It must be a string consisting	2166	auto detection and -probing kicks in.
1851	entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended	2167
		2168	It normally is a string consisting entirely of ASCII letters (e.g. C<EV>
		2169	or C<IOAsync>). The string C<AnyEvent::Impl::> gets prepended and the
1852	and the resulting module name is loaded and if the load was successful,	2170	resulting module name is loaded and - if the load was successful - used as
1853	used as event model. If it fails to load AnyEvent will proceed with	2171	event model backend. If it fails to load then AnyEvent will proceed with
1854	auto detection and -probing.	2172	auto detection and -probing.
1855		2173
1856	This functionality might change in future versions.	2174	If the string ends with C<::> instead (e.g. C<AnyEvent::Impl::EV::>) then
		2175	nothing gets prepended and the module name is used as-is (hint: C<::> at
		2176	the end of a string designates a module name and quotes it appropriately).
1857		2177
1858	For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you	2178	For example, to force the pure perl model (L<AnyEvent::Loop::Perl>) you
1859	could start your program like this:	2179	could start your program like this:
1860		2180
1861	PERL_ANYEVENT_MODEL=Perl perl ...	2181	PERL_ANYEVENT_MODEL=Perl perl ...
		2182
		2183	=item C<PERL_ANYEVENT_IO_MODEL>
		2184
		2185	The current file I/O model - see L<AnyEvent::IO> for more info.
		2186
		2187	At the moment, only C<Perl> (small, pure-perl, synchronous) and
		2188	C<IOAIO> (truly asynchronous) are supported. The default is C<IOAIO> if
		2189	L<AnyEvent::AIO> can be loaded, otherwise it is C<Perl>.
1862		2190
1863	=item C<PERL_ANYEVENT_PROTOCOLS>	2191	=item C<PERL_ANYEVENT_PROTOCOLS>
1864		2192
1865	Used by both L<AnyEvent::DNS> and L<AnyEvent::Socket> to determine preferences	2193	Used by both L<AnyEvent::DNS> and L<AnyEvent::Socket> to determine preferences
1866	for IPv4 or IPv6. The default is unspecified (and might change, or be the result	2194	for IPv4 or IPv6. The default is unspecified (and might change, or be the result
…		…
1879	but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4>	2207	but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4>
1880	- only support IPv4, never try to resolve or contact IPv6	2208	- only support IPv4, never try to resolve or contact IPv6
1881	addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or	2209	addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or
1882	IPv6, but prefer IPv6 over IPv4.	2210	IPv6, but prefer IPv6 over IPv4.
1883		2211
		2212	=item C<PERL_ANYEVENT_HOSTS>
		2213
		2214	This variable, if specified, overrides the F</etc/hosts> file used by
		2215	L<AnyEvent::Socket>C<::resolve_sockaddr>, i.e. hosts aliases will be read
		2216	from that file instead.
		2217
1884	=item C<PERL_ANYEVENT_EDNS0>	2218	=item C<PERL_ANYEVENT_EDNS0>
1885		2219
1886	Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension	2220	Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension for
1887	for DNS. This extension is generally useful to reduce DNS traffic, but	2221	DNS. This extension is generally useful to reduce DNS traffic, especially
1888	some (broken) firewalls drop such DNS packets, which is why it is off by	2222	when DNSSEC is involved, but some (broken) firewalls drop such DNS
1889	default.	2223	packets, which is why it is off by default.
1890		2224
1891	Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce	2225	Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce
1892	EDNS0 in its DNS requests.	2226	EDNS0 in its DNS requests.
1893		2227
1894	=item C<PERL_ANYEVENT_MAX_FORKS>	2228	=item C<PERL_ANYEVENT_MAX_FORKS>
…		…
1900		2234
1901	The default value for the C<max_outstanding> parameter for the default DNS	2235	The default value for the C<max_outstanding> parameter for the default DNS
1902	resolver - this is the maximum number of parallel DNS requests that are	2236	resolver - this is the maximum number of parallel DNS requests that are
1903	sent to the DNS server.	2237	sent to the DNS server.
1904		2238
		2239	=item C<PERL_ANYEVENT_MAX_SIGNAL_LATENCY>
		2240
		2241	Perl has inherently racy signal handling (you can basically choose between
		2242	losing signals and memory corruption) - pure perl event loops (including
		2243	C<AnyEvent::Loop>, when C<Async::Interrupt> isn't available) therefore
		2244	have to poll regularly to avoid losing signals.
		2245
		2246	Some event loops are racy, but don't poll regularly, and some event loops
		2247	are written in C but are still racy. For those event loops, AnyEvent
		2248	installs a timer that regularly wakes up the event loop.
		2249
		2250	By default, the interval for this timer is C<10> seconds, but you can
		2251	override this delay with this environment variable (or by setting
		2252	the C<$AnyEvent::MAX_SIGNAL_LATENCY> variable before creating signal
		2253	watchers).
		2254
		2255	Lower values increase CPU (and energy) usage, higher values can introduce
		2256	long delays when reaping children or waiting for signals.
		2257
		2258	The L<AnyEvent::Async> module, if available, will be used to avoid this
		2259	polling (with most event loops).
		2260
1905	=item C<PERL_ANYEVENT_RESOLV_CONF>	2261	=item C<PERL_ANYEVENT_RESOLV_CONF>
1906		2262
1907	The file to use instead of F</etc/resolv.conf> (or OS-specific	2263	The absolute path to a F<resolv.conf>-style file to use instead of
1908	configuration) in the default resolver. When set to the empty string, no	2264	F</etc/resolv.conf> (or the OS-specific configuration) in the default
1909	default config will be used.	2265	resolver, or the empty string to select the default configuration.
1910		2266
1911	=item C<PERL_ANYEVENT_CA_FILE>, C<PERL_ANYEVENT_CA_PATH>.	2267	=item C<PERL_ANYEVENT_CA_FILE>, C<PERL_ANYEVENT_CA_PATH>.
1912		2268
1913	When neither C<ca_file> nor C<ca_path> was specified during	2269	When neither C<ca_file> nor C<ca_path> was specified during
1914	L<AnyEvent::TLS> context creation, and either of these environment	2270	L<AnyEvent::TLS> context creation, and either of these environment
1915	variables exist, they will be used to specify CA certificate locations	2271	variables are nonempty, they will be used to specify CA certificate
1916	instead of a system-dependent default.	2272	locations instead of a system-dependent default.
1917		2273
1918	=item C<PERL_ANYEVENT_AVOID_GUARD> and C<PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT>	2274	=item C<PERL_ANYEVENT_AVOID_GUARD> and C<PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT>
1919		2275
1920	When these are set to C<1>, then the respective modules are not	2276	When these are set to C<1>, then the respective modules are not
1921	loaded. Mostly good for testing AnyEvent itself.	2277	loaded. Mostly good for testing AnyEvent itself.
…		…
2253	(even when used without AnyEvent), but most event loops have acceptable	2609	(even when used without AnyEvent), but most event loops have acceptable
2254	performance with or without AnyEvent.	2610	performance with or without AnyEvent.
2255		2611
2256	=item * The overhead AnyEvent adds is usually much smaller than the overhead of	2612	=item * The overhead AnyEvent adds is usually much smaller than the overhead of
2257	the actual event loop, only with extremely fast event loops such as EV	2613	the actual event loop, only with extremely fast event loops such as EV
2258	adds AnyEvent significant overhead.	2614	does AnyEvent add significant overhead.
2259		2615
2260	=item * You should avoid POE like the plague if you want performance or	2616	=item * You should avoid POE like the plague if you want performance or
2261	reasonable memory usage.	2617	reasonable memory usage.
2262		2618
2263	=back	2619	=back
…		…
2493	unless defined $SIG{PIPE};	2849	unless defined $SIG{PIPE};
2494		2850
2495	=head1 RECOMMENDED/OPTIONAL MODULES	2851	=head1 RECOMMENDED/OPTIONAL MODULES
2496		2852
2497	One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and	2853	One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and
2498	it's built-in modules) are required to use it.	2854	its built-in modules) are required to use it.
2499		2855
2500	That does not mean that AnyEvent won't take advantage of some additional	2856	That does not mean that AnyEvent won't take advantage of some additional
2501	modules if they are installed.	2857	modules if they are installed.
2502		2858
2503	This section explains which additional modules will be used, and how they	2859	This section explains which additional modules will be used, and how they
…		…
2561	the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL.	2917	the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL.
2562		2918
2563	=item L<Time::HiRes>	2919	=item L<Time::HiRes>
2564		2920
2565	This module is part of perl since release 5.008. It will be used when the	2921	This module is part of perl since release 5.008. It will be used when the
2566	chosen event library does not come with a timing source on it's own. The	2922	chosen event library does not come with a timing source of its own. The
2567	pure-perl event loop (L<AnyEvent::Impl::Perl>) will additionally use it to	2923	pure-perl event loop (L<AnyEvent::Loop>) will additionally load it to
2568	try to use a monotonic clock for timing stability.	2924	try to use a monotonic clock for timing stability.
2569		2925
2570	=back	2926	=back
2571		2927
2572		2928
…		…
2634	pronounced).	2990	pronounced).
2635		2991
2636		2992
2637	=head1 SEE ALSO	2993	=head1 SEE ALSO
2638		2994
2639	Utility functions: L<AnyEvent::Util>.	2995	Tutorial/Introduction: L<AnyEvent::Intro>.
2640		2996
2641	Event modules: L<EV>, L<EV::Glib>, L<Glib::EV>, L<Event>, L<Glib::Event>,	2997	FAQ: L<AnyEvent::FAQ>.
2642	L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.	2998
		2999	Utility functions: L<AnyEvent::Util> (misc. grab-bag), L<AnyEvent::Log>
		3000	(simply logging).
		3001
		3002	Development/Debugging: L<AnyEvent::Strict> (stricter checking),
		3003	L<AnyEvent::Debug> (interactive shell, watcher tracing).
		3004
		3005	Supported event modules: L<AnyEvent::Loop>, L<EV>, L<EV::Glib>,
		3006	L<Glib::EV>, L<Event>, L<Glib::Event>, L<Glib>, L<Tk>, L<Event::Lib>,
		3007	L<Qt>, L<POE>, L<FLTK>.
2643		3008
2644	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,	3009	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,
2645	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,	3010	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,
2646	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,	3011	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,
2647	L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>, L<Anyevent::Impl::Irssi>.	3012	L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>, L<Anyevent::Impl::Irssi>,
		3013	L<AnyEvent::Impl::FLTK>.
2648		3014
2649	Non-blocking file handles, sockets, TCP clients and	3015	Non-blocking handles, pipes, stream sockets, TCP clients and
2650	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.	3016	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.
2651		3017
		3018	Asynchronous File I/O: L<AnyEvent::IO>.
		3019
2652	Asynchronous DNS: L<AnyEvent::DNS>.	3020	Asynchronous DNS: L<AnyEvent::DNS>.
2653		3021
2654	Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>,	3022	Thread support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>.
2655	L<Coro::Event>,
2656		3023
2657	Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::XMPP>,	3024	Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::IRC>,
2658	L<AnyEvent::HTTP>.	3025	L<AnyEvent::HTTP>.
2659		3026
2660		3027
2661	=head1 AUTHOR	3028	=head1 AUTHOR
2662		3029
2663	Marc Lehmann <schmorp@schmorp.de>	3030	Marc Lehmann <schmorp@schmorp.de>
2664	http://home.schmorp.de/	3031	http://anyevent.schmorp.de
2665		3032
2666	=cut	3033	=cut
2667		3034
2668	1	3035	1
2669		3036

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