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Revision 1.406 by root, Thu Nov 15 01:17:29 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
		12	# if you prefer function calls, look at the AE manpage for
		13	# an alternative API.
		14
12	# file descriptor readable	15	# file handle or descriptor readable
13	my $w = AnyEvent->io (fh => $fh, poll => "r", cb => sub { ... });	16	my $w = AnyEvent->io (fh => $fh, poll => "r", cb => sub { ... });
14		17
15	# one-shot or repeating timers	18	# one-shot or repeating timers
16	my $w = AnyEvent->timer (after => $seconds, cb => sub { ... });	19	my $w = AnyEvent->timer (after => $seconds, cb => sub { ... });
17	my $w = AnyEvent->timer (after => $seconds, interval => $seconds, cb => ...	20	my $w = AnyEvent->timer (after => $seconds, interval => $seconds, cb => ...);
18		21
19	print AnyEvent->now; # prints current event loop time	22	print AnyEvent->now; # prints current event loop time
20	print AnyEvent->time; # think Time::HiRes::time or simply CORE::time.	23	print AnyEvent->time; # think Time::HiRes::time or simply CORE::time.
21		24
22	# POSIX signal	25	# POSIX signal
…		…
43	in a tutorial or some gentle introduction, have a look at the	46	in a tutorial or some gentle introduction, have a look at the
44	L<AnyEvent::Intro> manpage.	47	L<AnyEvent::Intro> manpage.
45		48
46	=head1 SUPPORT	49	=head1 SUPPORT
47		50
		51	An FAQ document is available as L<AnyEvent::FAQ>.
		52
48	There is a mailinglist for discussing all things AnyEvent, and an IRC	53	There also is a mailinglist for discussing all things AnyEvent, and an IRC
49	channel, too.	54	channel, too.
50		55
51	See the AnyEvent project page at the B<Schmorpforge Ta-Sa Software	56	See the AnyEvent project page at the B<Schmorpforge Ta-Sa Software
52	Repository>, at L<http://anyevent.schmorp.de>, for more info.	57	Repository>, at L<http://anyevent.schmorp.de>, for more info.
53		58
…		…
73	module users into the same thing by forcing them to use the same event	78	module users into the same thing by forcing them to use the same event
74	model you use.	79	model you use.
75		80
76	For modules like POE or IO::Async (which is a total misnomer as it is	81	For modules like POE or IO::Async (which is a total misnomer as it is
77	actually doing all I/O I<synchronously>...), using them in your module is	82	actually doing all I/O I<synchronously>...), using them in your module is
78	like joining a cult: After you joined, you are dependent on them and you	83	like joining a cult: After you join, you are dependent on them and you
79	cannot use anything else, as they are simply incompatible to everything	84	cannot use anything else, as they are simply incompatible to everything
80	that isn't them. What's worse, all the potential users of your	85	that isn't them. What's worse, all the potential users of your
81	module are I<also> forced to use the same event loop you use.	86	module are I<also> forced to use the same event loop you use.
82		87
83	AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works	88	AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works
84	fine. AnyEvent + Tk works fine etc. etc. but none of these work together	89	fine. AnyEvent + Tk works fine etc. etc. but none of these work together
85	with the rest: POE + IO::Async? No go. Tk + Event? No go. Again: if	90	with the rest: POE + EV? No go. Tk + Event? No go. Again: if your module
86	your module uses one of those, every user of your module has to use it,	91	uses one of those, every user of your module has to use it, too. But if
87	too. But if your module uses AnyEvent, it works transparently with all	92	your module uses AnyEvent, it works transparently with all event models it
88	event models it supports (including stuff like IO::Async, as long as those	93	supports (including stuff like IO::Async, as long as those use one of the
89	use one of the supported event loops. It is trivial to add new event loops	94	supported event loops. It is easy to add new event loops to AnyEvent, too,
90	to AnyEvent, too, so it is future-proof).	95	so it is future-proof).
91		96
92	In addition to being free of having to use I<the one and only true event	97	In addition to being free of having to use I<the one and only true event
93	model>, AnyEvent also is free of bloat and policy: with POE or similar	98	model>, AnyEvent also is free of bloat and policy: with POE or similar
94	modules, you get an enormous amount of code and strict rules you have to	99	modules, you get an enormous amount of code and strict rules you have to
95	follow. AnyEvent, on the other hand, is lean and up to the point, by only	100	follow. AnyEvent, on the other hand, is lean and to the point, by only
96	offering the functionality that is necessary, in as thin as a wrapper as	101	offering the functionality that is necessary, in as thin as a wrapper as
97	technically possible.	102	technically possible.
98		103
99	Of course, AnyEvent comes with a big (and fully optional!) toolbox	104	Of course, AnyEvent comes with a big (and fully optional!) toolbox
100	of useful functionality, such as an asynchronous DNS resolver, 100%	105	of useful functionality, such as an asynchronous DNS resolver, 100%
…		…
106	useful) and you want to force your users to use the one and only event	111	useful) and you want to force your users to use the one and only event
107	model, you should I<not> use this module.	112	model, you should I<not> use this module.
108		113
109	=head1 DESCRIPTION	114	=head1 DESCRIPTION
110		115
111	L<AnyEvent> provides an identical interface to multiple event loops. This	116	L<AnyEvent> provides a uniform interface to various event loops. This
112	allows module authors to utilise an event loop without forcing module	117	allows module authors to use event loop functionality without forcing
113	users to use the same event loop (as only a single event loop can coexist	118	module users to use a specific event loop implementation (since more
114	peacefully at any one time).	119	than one event loop cannot coexist peacefully).
115		120
116	The interface itself is vaguely similar, but not identical to the L<Event>	121	The interface itself is vaguely similar, but not identical to the L<Event>
117	module.	122	module.
118		123
119	During the first call of any watcher-creation method, the module tries	124	During the first call of any watcher-creation method, the module tries
120	to detect the currently loaded event loop by probing whether one of the	125	to detect the currently loaded event loop by probing whether one of the
121	following modules is already loaded: L<EV>,	126	following modules is already loaded: L<EV>, L<AnyEvent::Loop>,
122	L<Event>, L<Glib>, L<AnyEvent::Impl::Perl>, L<Tk>, L<Event::Lib>, L<Qt>,	127	L<Event>, L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>. The first one
123	L<POE>. The first one found is used. If none are found, the module tries	128	found is used. If none are detected, the module tries to load the first
124	to load these modules (excluding Tk, Event::Lib, Qt and POE as the pure perl	129	four modules in the order given; but note that if L<EV> is not
125	adaptor should always succeed) in the order given. The first one that can	130	available, the pure-perl L<AnyEvent::Loop> should always work, so
126	be successfully loaded will be used. If, after this, still none could be	131	the other two are not normally tried.
127	found, AnyEvent will fall back to a pure-perl event loop, which is not
128	very efficient, but should work everywhere.
129		132
130	Because AnyEvent first checks for modules that are already loaded, loading	133	Because AnyEvent first checks for modules that are already loaded, loading
131	an event model explicitly before first using AnyEvent will likely make	134	an event model explicitly before first using AnyEvent will likely make
132	that model the default. For example:	135	that model the default. For example:
133		136
…		…
135	use AnyEvent;	138	use AnyEvent;
136		139
137	# .. AnyEvent will likely default to Tk	140	# .. AnyEvent will likely default to Tk
138		141
139	The I<likely> means that, if any module loads another event model and	142	The I<likely> means that, if any module loads another event model and
140	starts using it, all bets are off. Maybe you should tell their authors to	143	starts using it, all bets are off - this case should be very rare though,
141	use AnyEvent so their modules work together with others seamlessly...	144	as very few modules hardcode event loops without announcing this very
		145	loudly.
142		146
143	The pure-perl implementation of AnyEvent is called	147	The pure-perl implementation of AnyEvent is called C<AnyEvent::Loop>. Like
144	C<AnyEvent::Impl::Perl>. Like other event modules you can load it	148	other event modules you can load it explicitly and enjoy the high
145	explicitly and enjoy the high availability of that event loop :)	149	availability of that event loop :)
146		150
147	=head1 WATCHERS	151	=head1 WATCHERS
148		152
149	AnyEvent has the central concept of a I<watcher>, which is an object that	153	AnyEvent has the central concept of a I<watcher>, which is an object that
150	stores relevant data for each kind of event you are waiting for, such as	154	stores relevant data for each kind of event you are waiting for, such as
…		…
155	callback when the event occurs (of course, only when the event model	159	callback when the event occurs (of course, only when the event model
156	is in control).	160	is in control).
157		161
158	Note that B<callbacks must not permanently change global variables>	162	Note that B<callbacks must not permanently change global variables>
159	potentially in use by the event loop (such as C<$_> or C<$[>) and that B<<	163	potentially in use by the event loop (such as C<$_> or C<$[>) and that B<<
160	callbacks must not C<die> >>. The former is good programming practise in	164	callbacks must not C<die> >>. The former is good programming practice in
161	Perl and the latter stems from the fact that exception handling differs	165	Perl and the latter stems from the fact that exception handling differs
162	widely between event loops.	166	widely between event loops.
163		167
164	To disable the watcher you have to destroy it (e.g. by setting the	168	To disable a watcher you have to destroy it (e.g. by setting the
165	variable you store it in to C<undef> or otherwise deleting all references	169	variable you store it in to C<undef> or otherwise deleting all references
166	to it).	170	to it).
167		171
168	All watchers are created by calling a method on the C<AnyEvent> class.	172	All watchers are created by calling a method on the C<AnyEvent> class.
169		173
170	Many watchers either are used with "recursion" (repeating timers for	174	Many watchers either are used with "recursion" (repeating timers for
171	example), or need to refer to their watcher object in other ways.	175	example), or need to refer to their watcher object in other ways.
172		176
173	An any way to achieve that is this pattern:	177	One way to achieve that is this pattern:
174		178
175	my $w; $w = AnyEvent->type (arg => value ..., cb => sub {	179	my $w; $w = AnyEvent->type (arg => value ..., cb => sub {
176	# you can use $w here, for example to undef it	180	# you can use $w here, for example to undef it
177	undef $w;	181	undef $w;
178	});	182	});
…		…
210		214
211	The I/O watcher might use the underlying file descriptor or a copy of it.	215	The I/O watcher might use the underlying file descriptor or a copy of it.
212	You must not close a file handle as long as any watcher is active on the	216	You must not close a file handle as long as any watcher is active on the
213	underlying file descriptor.	217	underlying file descriptor.
214		218
215	Some event loops issue spurious readyness notifications, so you should	219	Some event loops issue spurious readiness notifications, so you should
216	always use non-blocking calls when reading/writing from/to your file	220	always use non-blocking calls when reading/writing from/to your file
217	handles.	221	handles.
218		222
219	Example: wait for readability of STDIN, then read a line and disable the	223	Example: wait for readability of STDIN, then read a line and disable the
220	watcher.	224	watcher.
…		…
244		248
245	Although the callback might get passed parameters, their value and	249	Although the callback might get passed parameters, their value and
246	presence is undefined and you cannot rely on them. Portable AnyEvent	250	presence is undefined and you cannot rely on them. Portable AnyEvent
247	callbacks cannot use arguments passed to time watcher callbacks.	251	callbacks cannot use arguments passed to time watcher callbacks.
248		252
249	The callback will normally be invoked once only. If you specify another	253	The callback will normally be invoked only once. If you specify another
250	parameter, C<interval>, as a strictly positive number (> 0), then the	254	parameter, C<interval>, as a strictly positive number (> 0), then the
251	callback will be invoked regularly at that interval (in fractional	255	callback will be invoked regularly at that interval (in fractional
252	seconds) after the first invocation. If C<interval> is specified with a	256	seconds) after the first invocation. If C<interval> is specified with a
253	false value, then it is treated as if it were missing.	257	false value, then it is treated as if it were not specified at all.
254		258
255	The callback will be rescheduled before invoking the callback, but no	259	The callback will be rescheduled before invoking the callback, but no
256	attempt is done to avoid timer drift in most backends, so the interval is	260	attempt is made to avoid timer drift in most backends, so the interval is
257	only approximate.	261	only approximate.
258		262
259	Example: fire an event after 7.7 seconds.	263	Example: fire an event after 7.7 seconds.
260		264
261	my $w = AnyEvent->timer (after => 7.7, cb => sub {	265	my $w = AnyEvent->timer (after => 7.7, cb => sub {
…		…
279		283
280	While most event loops expect timers to specified in a relative way, they	284	While most event loops expect timers to specified in a relative way, they
281	use absolute time internally. This makes a difference when your clock	285	use absolute time internally. This makes a difference when your clock
282	"jumps", for example, when ntp decides to set your clock backwards from	286	"jumps", for example, when ntp decides to set your clock backwards from
283	the wrong date of 2014-01-01 to 2008-01-01, a watcher that is supposed to	287	the wrong date of 2014-01-01 to 2008-01-01, a watcher that is supposed to
284	fire "after" a second might actually take six years to finally fire.	288	fire "after a second" might actually take six years to finally fire.
285		289
286	AnyEvent cannot compensate for this. The only event loop that is conscious	290	AnyEvent cannot compensate for this. The only event loop that is conscious
287	about these issues is L<EV>, which offers both relative (ev_timer, based	291	of these issues is L<EV>, which offers both relative (ev_timer, based
288	on true relative time) and absolute (ev_periodic, based on wallclock time)	292	on true relative time) and absolute (ev_periodic, based on wallclock time)
289	timers.	293	timers.
290		294
291	AnyEvent always prefers relative timers, if available, matching the	295	AnyEvent always prefers relative timers, if available, matching the
292	AnyEvent API.	296	AnyEvent API.
…		…
314	I<In almost all cases (in all cases if you don't care), this is the	318	I<In almost all cases (in all cases if you don't care), this is the
315	function to call when you want to know the current time.>	319	function to call when you want to know the current time.>
316		320
317	This function is also often faster then C<< AnyEvent->time >>, and	321	This function is also often faster then C<< AnyEvent->time >>, and
318	thus the preferred method if you want some timestamp (for example,	322	thus the preferred method if you want some timestamp (for example,
319	L<AnyEvent::Handle> uses this to update it's activity timeouts).	323	L<AnyEvent::Handle> uses this to update its activity timeouts).
320		324
321	The rest of this section is only of relevance if you try to be very exact	325	The rest of this section is only of relevance if you try to be very exact
322	with your timing, you can skip it without bad conscience.	326	with your timing; you can skip it without a bad conscience.
323		327
324	For a practical example of when these times differ, consider L<Event::Lib>	328	For a practical example of when these times differ, consider L<Event::Lib>
325	and L<EV> and the following set-up:	329	and L<EV> and the following set-up:
326		330
327	The event loop is running and has just invoked one of your callback at	331	The event loop is running and has just invoked one of your callbacks at
328	time=500 (assume no other callbacks delay processing). In your callback,	332	time=500 (assume no other callbacks delay processing). In your callback,
329	you wait a second by executing C<sleep 1> (blocking the process for a	333	you wait a second by executing C<sleep 1> (blocking the process for a
330	second) and then (at time=501) you create a relative timer that fires	334	second) and then (at time=501) you create a relative timer that fires
331	after three seconds.	335	after three seconds.
332		336
…		…
352	difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into	356	difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into
353	account.	357	account.
354		358
355	=item AnyEvent->now_update	359	=item AnyEvent->now_update
356		360
357	Some event loops (such as L<EV> or L<AnyEvent::Impl::Perl>) cache	361	Some event loops (such as L<EV> or L<AnyEvent::Loop>) cache the current
358	the current time for each loop iteration (see the discussion of L<<	362	time for each loop iteration (see the discussion of L<< AnyEvent->now >>,
359	AnyEvent->now >>, above).	363	above).
360		364
361	When a callback runs for a long time (or when the process sleeps), then	365	When a callback runs for a long time (or when the process sleeps), then
362	this "current" time will differ substantially from the real time, which	366	this "current" time will differ substantially from the real time, which
363	might affect timers and time-outs.	367	might affect timers and time-outs.
364		368
…		…
411	not restart syscalls (that includes L<Async::Interrupt> and AnyEvent's	415	not restart syscalls (that includes L<Async::Interrupt> and AnyEvent's
412	pure perl implementation).	416	pure perl implementation).
413		417
414	=head3 Safe/Unsafe Signals	418	=head3 Safe/Unsafe Signals
415		419
416	Perl signals can be either "safe" (synchronous to opcode handling) or	420	Perl signals can be either "safe" (synchronous to opcode handling)
417	"unsafe" (asynchronous) - the former might get delayed indefinitely, the	421	or "unsafe" (asynchronous) - the former might delay signal delivery
418	latter might corrupt your memory.	422	indefinitely, the latter might corrupt your memory.
419		423
420	AnyEvent signal handlers are, in addition, synchronous to the event loop,	424	AnyEvent signal handlers are, in addition, synchronous to the event loop,
421	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
422	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.
423	callbacks, too).	427	callbacks, too).
424		428
425	=head3 Signal Races, Delays and Workarounds	429	=head3 Signal Races, Delays and Workarounds
426		430
427	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
428	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,
429	do race-free signal handling in perl, requiring C libraries for	433	as you cannot do race-free signal handling in perl, requiring
430	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
431	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
432	specified in C<$AnyEvent::MAX_SIGNAL_LATENCY> (default: 10 seconds). This	436	a signal might be delayed is 10 seconds by default, but can
433	variable can be changed only before the first signal watcher is created,	437	be overriden via C<$ENV{PERL_ANYEVENT_MAX_SIGNAL_LATENCY}> or
434	and should be left alone otherwise. This variable determines how often	438	C<$AnyEvent::MAX_SIGNAL_LATENCY> - see the L<ENVIRONMENT VARIABLES>
435	AnyEvent polls for signals (in case a wake-up was missed). Higher values	439	section for details.
436	will cause fewer spurious wake-ups, which is better for power and CPU
437	saving.
438		440
439	All these problems can be avoided by installing the optional	441	All these problems can be avoided by installing the optional
440	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
441	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>
442	(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
443	one-second latency). For those, you just have to suffer the delays.	445	delays.
444		446
445	=head2 CHILD PROCESS WATCHERS	447	=head2 CHILD PROCESS WATCHERS
446		448
447	$w = AnyEvent->child (pid => <process id>, cb => <callback>);	449	$w = AnyEvent->child (pid => <process id>, cb => <callback>);
448		450
449	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.
450		452
451	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,
452	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
453	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
454	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
455	(stopped/continued).	457	(stopped/continued).
456		458
…		…
478	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
479	watcher before you C<fork> the child (alternatively, you can call	481	watcher before you C<fork> the child (alternatively, you can call
480	C<AnyEvent::detect>).	482	C<AnyEvent::detect>).
481		483
482	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
483	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
484	mentioned in the description of signal watchers apply.	486	problems mentioned in the description of signal watchers apply.
485		487
486	Example: fork a process and wait for it	488	Example: fork a process and wait for it
487		489
488	my $done = AnyEvent->condvar;	490	my $done = AnyEvent->condvar;
489		491
…		…
503		505
504	=head2 IDLE WATCHERS	506	=head2 IDLE WATCHERS
505		507
506	$w = AnyEvent->idle (cb => <callback>);	508	$w = AnyEvent->idle (cb => <callback>);
507		509
508	Repeatedly invoke the callback after the process becomes idle, until	510	This will repeatedly invoke the callback after the process becomes idle,
509	either the watcher is destroyed or new events have been detected.	511	until either the watcher is destroyed or new events have been detected.
510		512
511	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
512	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
513	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
514	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
…		…
553	will actively watch for new events and call your callbacks.	555	will actively watch for new events and call your callbacks.
554		556
555	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
556	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).
557		559
558	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
559	because they represent a condition that must become true.	561	they represent a condition that must become true.
560		562
561	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.
562		564
563	Condition variables can be created by calling the C<< AnyEvent->condvar	565	Condition variables can be created by calling the C<< AnyEvent->condvar
564	>> method, usually without arguments. The only argument pair allowed is	566	>> method, usually without arguments. The only argument pair allowed is
…		…
569	After creation, the condition variable is "false" until it becomes "true"	571	After creation, the condition variable is "false" until it becomes "true"
570	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
571	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<<
572	->send >> method).	574	->send >> method).
573		575
574	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
575	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:
576	in time where multiple outstanding events have been processed. And yet	578
577	another way to call them is transactions - each condition variable can be	579	=over 4
578	used to represent a transaction, which finishes at some point and delivers	580
579	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
580	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
581		599
582	Condition variables are very useful to signal that something has finished,	600	Condition variables are very useful to signal that something has finished,
583	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,
584	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
585	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
…		…
598		616
599	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
600	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
601	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
602	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
603	it's C<new> method in your own C<new> method.	621	its C<new> method in your own C<new> method.
604		622
605	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
606	eventually calls C<< -> send >>, and the "consumer side", which waits	624	eventually calls C<< -> send >>, and the "consumer side", which waits
607	for the send to occur.	625	for the send to occur.
608		626
609	Example: wait for a timer.	627	Example: wait for a timer.
610		628
611	# wait till the result is ready	629	# condition: "wait till the timer is fired"
612	my $result_ready = AnyEvent->condvar;	630	my $timer_fired = AnyEvent->condvar;
613		631
614	# do something such as adding a timer	632	# create the timer - we could wait for, say
615	# or socket watcher the calls $result_ready->send	633	# a handle becomign ready, or even an
616	# when the "result" is ready.	634	# AnyEvent::HTTP request to finish, but
617	# in this case, we simply use a timer:	635	# in this case, we simply use a timer:
618	my $w = AnyEvent->timer (	636	my $w = AnyEvent->timer (
619	after => 1,	637	after => 1,
620	cb => sub { $result_ready->send },	638	cb => sub { $timer_fired->send },
621	);	639	);
622		640
623	# this "blocks" (while handling events) till the callback	641	# this "blocks" (while handling events) till the callback
624	# calls ->send	642	# calls ->send
625	$result_ready->recv;	643	$timer_fired->recv;
626		644
627	Example: wait for a timer, but take advantage of the fact that condition	645	Example: wait for a timer, but take advantage of the fact that condition
628	variables are also callable directly.	646	variables are also callable directly.
629		647
630	my $done = AnyEvent->condvar;	648	my $done = AnyEvent->condvar;
…		…
673	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
674	C<send>.	692	C<send>.
675		693
676	=item $cv->croak ($error)	694	=item $cv->croak ($error)
677		695
678	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
679	C<Carp::croak> with the given error message/object/scalar.	697	C<Carp::croak> with the given error message/object/scalar.
680		698
681	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
682	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
683	delays the error detetcion, but has the overwhelmign advantage that it	701	delays the error detection, but has the overwhelming advantage that it
684	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
685	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
686	the problem.	704	the problem.
687		705
688	=item $cv->begin ([group callback])	706	=item $cv->begin ([group callback])
689		707
690	=item $cv->end	708	=item $cv->end
…		…
728	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
729	sending.	747	sending.
730		748
731	The ping example mentioned above is slightly more complicated, as the	749	The ping example mentioned above is slightly more complicated, as the
732	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
733	begung can potentially be zero:	751	begun can potentially be zero:
734		752
735	my $cv = AnyEvent->condvar;	753	my $cv = AnyEvent->condvar;
736		754
737	my %result;	755	my %result;
738	$cv->begin (sub { shift->send (\%result) });	756	$cv->begin (sub { shift->send (\%result) });
…		…
759	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
760	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
761	doesn't execute once).	779	doesn't execute once).
762		780
763	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
764	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
765	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
766	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,
767	call C<end>.	785	call C<end>.
768		786
769	=back	787	=back
…		…
776	=over 4	794	=over 4
777		795
778	=item $cv->recv	796	=item $cv->recv
779		797
780	Wait (blocking if necessary) until the C<< ->send >> or C<< ->croak	798	Wait (blocking if necessary) until the C<< ->send >> or C<< ->croak
781	>> methods have been called on c<$cv>, while servicing other watchers	799	>> methods have been called on C<$cv>, while servicing other watchers
782	normally.	800	normally.
783		801
784	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
785	will return immediately.	803	will return immediately.
786		804
…		…
803	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
804	condition variables with some kind of request results and supporting	822	condition variables with some kind of request results and supporting
805	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,
806	while still supporting blocking waits if the caller so desires).	824	while still supporting blocking waits if the caller so desires).
807		825
808	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
809	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
810	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
811	waits otherwise.	829	waits otherwise.
812		830
813	=item $bool = $cv->ready	831	=item $bool = $cv->ready
…		…
818	=item $cb = $cv->cb ($cb->($cv))	836	=item $cb = $cv->cb ($cb->($cv))
819		837
820	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
821	replaces it before doing so.	839	replaces it before doing so.
822		840
823	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
824	"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
825	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
826	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.
827		846
828	=back	847	=back
829		848
830	=head1 SUPPORTED EVENT LOOPS/BACKENDS	849	=head1 SUPPORTED EVENT LOOPS/BACKENDS
831		850
…		…
839	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
840	pure-perl implementation, which is available everywhere as it comes with	859	pure-perl implementation, which is available everywhere as it comes with
841	AnyEvent itself.	860	AnyEvent itself.
842		861
843	AnyEvent::Impl::EV based on EV (interface to libev, best choice).	862	AnyEvent::Impl::EV based on EV (interface to libev, best choice).
844	AnyEvent::Impl::Perl pure-perl implementation, fast and portable.	863	AnyEvent::Impl::Perl pure-perl AnyEvent::Loop, fast and portable.
845		864
846	=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.
847		866
848	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
849	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
850	them. This means that AnyEvent will automatically pick the right backend	869	them. This means that AnyEvent will automatically pick the right backend
851	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
852	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.
853		872
…		…
855	AnyEvent::Impl::Glib based on Glib, slow but very stable.	874	AnyEvent::Impl::Glib based on Glib, slow but very stable.
856	AnyEvent::Impl::Tk based on Tk, very broken.	875	AnyEvent::Impl::Tk based on Tk, very broken.
857	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.	876	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
858	AnyEvent::Impl::POE based on POE, very slow, some limitations.	877	AnyEvent::Impl::POE based on POE, very slow, some limitations.
859	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).
860		882
861	=item Backends with special needs.	883	=item Backends with special needs.
862		884
863	Qt requires the Qt::Application to be instantiated first, but will	885	Qt requires the Qt::Application to be instantiated first, but will
864	otherwise be picked up automatically. As long as the main program	886	otherwise be picked up automatically. As long as the main program
865	instantiates the application before any AnyEvent watchers are created,	887	instantiates the application before any AnyEvent watchers are created,
866	everything should just work.	888	everything should just work.
867		889
868	AnyEvent::Impl::Qt based on Qt.	890	AnyEvent::Impl::Qt based on Qt.
869		891
870	Support for IO::Async can only be partial, as it is too broken and
871	architecturally limited to even support the AnyEvent API. It also
872	is the only event loop that needs the loop to be set explicitly, so
873	it can only be used by a main program knowing about AnyEvent. See
874	L<AnyEvent::Impl::Async> for the gory details.
875
876	AnyEvent::Impl::IOAsync based on IO::Async, cannot be autoprobed.
877
878	=item Event loops that are indirectly supported via other backends.	892	=item Event loops that are indirectly supported via other backends.
879		893
880	Some event loops can be supported via other modules:	894	Some event loops can be supported via other modules:
881		895
882	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>.
…		…
907	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
908	backend has been autodetected.	922	backend has been autodetected.
909		923
910	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
911	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
912	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
913	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
914	will be C<urxvt::anyevent>).	928	will be C<urxvt::anyevent>).
915		929
916	=item AnyEvent::detect	930	=item AnyEvent::detect
917		931
918	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model	932	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model
919	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
920	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
921	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).
922		940
923	If you need to do some initialisation before AnyEvent watchers are	941	If you need to do some initialisation before AnyEvent watchers are
924	created, use C<post_detect>.	942	created, use C<post_detect>.
925		943
926	=item $guard = AnyEvent::post_detect { BLOCK }	944	=item $guard = AnyEvent::post_detect { BLOCK }
927		945
928	Arranges for the code block to be executed as soon as the event model is	946	Arranges for the code block to be executed as soon as the event model is
929	autodetected (or immediately if this has already happened).	947	autodetected (or immediately if that has already happened).
930		948
931	The block will be executed I<after> the actual backend has been detected	949	The block will be executed I<after> the actual backend has been detected
932	(C<$AnyEvent::MODEL> is set), but I<before> any watchers have been	950	(C<$AnyEvent::MODEL> is set), but I<before> any watchers have been
933	created, so it is possible to e.g. patch C<@AnyEvent::ISA> or do	951	created, so it is possible to e.g. patch C<@AnyEvent::ISA> or do
934	other initialisations - see the sources of L<AnyEvent::Strict> or	952	other initialisations - see the sources of L<AnyEvent::Strict> or
…		…
943	that automatically removes the callback again when it is destroyed (or	961	that automatically removes the callback again when it is destroyed (or
944	C<undef> when the hook was immediately executed). See L<AnyEvent::AIO> for	962	C<undef> when the hook was immediately executed). See L<AnyEvent::AIO> for
945	a case where this is useful.	963	a case where this is useful.
946		964
947	Example: Create a watcher for the IO::AIO module and store it in	965	Example: Create a watcher for the IO::AIO module and store it in
948	C<$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.
949		967
950	our WATCHER;	968	our WATCHER;
951		969
952	my $guard = AnyEvent::post_detect {	970	my $guard = AnyEvent::post_detect {
953	$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);
…		…
961	$WATCHER ||= $guard;	979	$WATCHER ||= $guard;
962		980
963	=item @AnyEvent::post_detect	981	=item @AnyEvent::post_detect
964		982
965	If there are any code references in this array (you can C<push> to it	983	If there are any code references in this array (you can C<push> to it
966	before or after loading AnyEvent), then they will called directly after	984	before or after loading AnyEvent), then they will be called directly
967	the event loop has been chosen.	985	after the event loop has been chosen.
968		986
969	You should check C<$AnyEvent::MODEL> before adding to this array, though:	987	You should check C<$AnyEvent::MODEL> before adding to this array, though:
970	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
971	array will be ignored.	989	array will be ignored.
972		990
…		…
989	# AnyEvent not yet initialised, so make sure to load Coro::AnyEvent	1007	# AnyEvent not yet initialised, so make sure to load Coro::AnyEvent
990	# as soon as it is	1008	# as soon as it is
991	push @AnyEvent::post_detect, sub { require Coro::AnyEvent };	1009	push @AnyEvent::post_detect, sub { require Coro::AnyEvent };
992	}	1010	}
993		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
994	=back	1070	=back
995		1071
996	=head1 WHAT TO DO IN A MODULE	1072	=head1 WHAT TO DO IN A MODULE
997		1073
998	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
…		…
1008	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
1009	events is to stay interactive.	1085	events is to stay interactive.
1010		1086
1011	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
1012	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
1013	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 >>
1014	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).
1015		1091
1016	=head1 WHAT TO DO IN THE MAIN PROGRAM	1092	=head1 WHAT TO DO IN THE MAIN PROGRAM
1017		1093
1018	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
1019	dictate which event model to use.	1095	dictate which event model to use.
1020		1096
1021	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
1022	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
1023	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.
1024		1102
1025	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
1026	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
1027	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
1028	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
1029	modules might create watchers when they are loaded, and AnyEvent will	1107	modules might create watchers when they are loaded, and AnyEvent will
1030	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
1031	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.
1032		1110
1033	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
1034	C<AnyEvent::Impl::Perl> module, which gives you similar behaviour	1112	C<AnyEvent::Loop> module, which gives you similar behaviour
1035	everywhere, but letting AnyEvent chose the model is generally better.	1113	everywhere, but letting AnyEvent chose the model is generally better.
1036		1114
1037	=head2 MAINLOOP EMULATION	1115	=head2 MAINLOOP EMULATION
1038		1116
1039	Sometimes (often for short test scripts, or even standalone programs who	1117	Sometimes (often for short test scripts, or even standalone programs who
…		…
1052		1130
1053		1131
1054	=head1 OTHER MODULES	1132	=head1 OTHER MODULES
1055		1133
1056	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
1057	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
1058	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
1059	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 :)
1060		1141
1061	=over 4	1142	=over 4
1062		1143
1063	=item L<AnyEvent::Util>	1144	=item L<AnyEvent::Util>
1064		1145
1065	Contains various utility functions that replace often-used but blocking	1146	Contains various utility functions that replace often-used blocking
1066	functions such as C<inet_aton> by event-/callback-based versions.	1147	functions such as C<inet_aton> with event/callback-based versions.
1067		1148
1068	=item L<AnyEvent::Socket>	1149	=item L<AnyEvent::Socket>
1069		1150
1070	Provides various utility functions for (internet protocol) sockets,	1151	Provides various utility functions for (internet protocol) sockets,
1071	addresses and name resolution. Also functions to create non-blocking tcp	1152	addresses and name resolution. Also functions to create non-blocking tcp
…		…
1073		1154
1074	=item L<AnyEvent::Handle>	1155	=item L<AnyEvent::Handle>
1075		1156
1076	Provide read and write buffers, manages watchers for reads and writes,	1157	Provide read and write buffers, manages watchers for reads and writes,
1077	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
1078	non-blocking SSL/TLS (via L<AnyEvent::TLS>.	1159	non-blocking SSL/TLS (via L<AnyEvent::TLS>).
1079		1160
1080	=item L<AnyEvent::DNS>	1161	=item L<AnyEvent::DNS>
1081		1162
1082	Provides rich asynchronous DNS resolver capabilities.	1163	Provides rich asynchronous DNS resolver capabilities.
1083		1164
		1165	=item L<AnyEvent::HTTP>, L<AnyEvent::IRC>, L<AnyEvent::XMPP>, L<AnyEvent::GPSD>, L<AnyEvent::IGS>, L<AnyEvent::FCP>
		1166
		1167	Implement event-based interfaces to the protocols of the same name (for
		1168	the curious, IGS is the International Go Server and FCP is the Freenet
		1169	Client Protocol).
		1170
1084	=item L<AnyEvent::HTTP>	1171	=item L<AnyEvent::AIO>
1085		1172
1086	A simple-to-use HTTP library that is capable of making a lot of concurrent	1173	Truly asynchronous (as opposed to non-blocking) I/O, should be in the
1087	HTTP requests.	1174	toolbox of every event programmer. AnyEvent::AIO transparently fuses
		1175	L<IO::AIO> and AnyEvent together, giving AnyEvent access to event-based
		1176	file I/O, and much more.
		1177
		1178	=item L<AnyEvent::Filesys::Notify>
		1179
		1180	AnyEvent is good for non-blocking stuff, but it can't detect file or
		1181	path changes (e.g. "watch this directory for new files", "watch this
		1182	file for changes"). The L<AnyEvent::Filesys::Notify> module promises to
		1183	do just that in a portbale fashion, supporting inotify on GNU/Linux and
		1184	some weird, without doubt broken, stuff on OS X to monitor files. It can
		1185	fall back to blocking scans at regular intervals transparently on other
		1186	platforms, so it's about as portable as it gets.
		1187
		1188	(I haven't used it myself, but I haven't heard anybody complaining about
		1189	it yet).
		1190
		1191	=item L<AnyEvent::DBI>
		1192
		1193	Executes L<DBI> requests asynchronously in a proxy process for you,
		1194	notifying you in an event-based way when the operation is finished.
1088		1195
1089	=item L<AnyEvent::HTTPD>	1196	=item L<AnyEvent::HTTPD>
1090		1197
1091	Provides a simple web application server framework.	1198	A simple embedded webserver.
1092		1199
1093	=item L<AnyEvent::FastPing>	1200	=item L<AnyEvent::FastPing>
1094		1201
1095	The fastest ping in the west.	1202	The fastest ping in the west.
1096		1203
1097	=item L<AnyEvent::DBI>
1098
1099	Executes L<DBI> requests asynchronously in a proxy process.
1100
1101	=item L<AnyEvent::AIO>
1102
1103	Truly asynchronous I/O, should be in the toolbox of every event
1104	programmer. AnyEvent::AIO transparently fuses L<IO::AIO> and AnyEvent
1105	together.
1106
1107	=item L<AnyEvent::BDB>
1108
1109	Truly asynchronous Berkeley DB access. AnyEvent::BDB transparently fuses
1110	L<BDB> and AnyEvent together.
1111
1112	=item L<AnyEvent::GPSD>
1113
1114	A non-blocking interface to gpsd, a daemon delivering GPS information.
1115
1116	=item L<AnyEvent::IRC>
1117
1118	AnyEvent based IRC client module family (replacing the older Net::IRC3).
1119
1120	=item L<AnyEvent::XMPP>
1121
1122	AnyEvent based XMPP (Jabber protocol) module family (replacing the older
1123	Net::XMPP2>.
1124
1125	=item L<AnyEvent::IGS>
1126
1127	A non-blocking interface to the Internet Go Server protocol (used by
1128	L<App::IGS>).
1129
1130	=item L<Net::FCP>
1131
1132	AnyEvent-based implementation of the Freenet Client Protocol, birthplace
1133	of AnyEvent.
1134
1135	=item L<Event::ExecFlow>
1136
1137	High level API for event-based execution flow control.
1138
1139	=item L<Coro>	1204	=item L<Coro>
1140		1205
1141	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	};
1142		1219
1143	=back	1220	=back
1144		1221
1145	=cut	1222	=cut
1146		1223
1147	package AnyEvent;	1224	package AnyEvent;
1148		1225
1149	# basically a tuned-down version of common::sense	1226	# basically a tuned-down version of common::sense
1150	sub common_sense {	1227	sub common_sense {
1151	# from common:.sense 1.0	1228	# from common:.sense 3.5
		1229	local $^W;
1152	${^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";
1153	# 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)
1154	$^H |= 0x00000600;	1232	$^H |= 0x00000600;
1155	}	1233	}
1156		1234
1157	BEGIN { AnyEvent::common_sense }	1235	BEGIN { AnyEvent::common_sense }
1158		1236
1159	use Carp ();	1237	use Carp ();
1160		1238
1161	our $VERSION = '5.25';	1239	our $VERSION = '7.03';
1162	our $MODEL;	1240	our $MODEL;
1163
1164	our $AUTOLOAD;
1165	our @ISA;	1241	our @ISA;
1166
1167	our @REGISTRY;	1242	our @REGISTRY;
1168
1169	our $VERBOSE;	1243	our $VERBOSE;
		1244	our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred
		1245	our $MAX_SIGNAL_LATENCY = $ENV{PERL_ANYEVENT_MAX_SIGNAL_LATENCY} || 10; # executes after the BEGIN block below (tainting!)
1170		1246
1171	BEGIN {	1247	BEGIN {
1172	require "AnyEvent/constants.pl";	1248	require "AnyEvent/constants.pl";
1173		1249
1174	eval "sub TAINT (){" . (${^TAINT} *1) . "}";	1250	eval "sub TAINT (){" . (${^TAINT}*1) . "}";
1175		1251
1176	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}	1252	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}
1177	if ${^TAINT};	1253	if ${^TAINT};
1178		1254
1179	$VERBOSE = $ENV{PERL_ANYEVENT_VERBOSE}*1;	1255	$ENV{"PERL_ANYEVENT_$_"} = $ENV{"AE_$_"}
		1256	for grep s/^AE_// && !exists $ENV{"PERL_ANYEVENT_$_"}, keys %ENV;
1180		1257
1181	}	1258	@ENV{grep /^PERL_ANYEVENT_/, keys %ENV} = ()
		1259	if ${^TAINT};
1182		1260
1183	our $MAX_SIGNAL_LATENCY = 10;	1261	# $ENV{PERL_ANYEVENT_xxx} now valid
1184		1262
1185	our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred	1263	$VERBOSE = length $ENV{PERL_ANYEVENT_VERBOSE} ? $ENV{PERL_ANYEVENT_VERBOSE}*1 : 4;
1186		1264
1187	{
1188	my $idx;	1265	my $idx;
1189	$PROTOCOL{$_} = ++$idx	1266	$PROTOCOL{$_} = ++$idx
1190	for reverse split /\s*,\s*/,	1267	for reverse split /\s*,\s*/,
1191	$ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";	1268	$ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";
1192	}	1269	}
1193		1270
		1271	our @post_detect;
		1272
		1273	sub post_detect(&) {
		1274	my ($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
1194	my @models = (	1348	our @models = (
1195	[EV:: => AnyEvent::Impl::EV:: , 1],	1349	[EV:: => AnyEvent::Impl::EV::],
1196	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl:: , 1],	1350	[AnyEvent::Loop:: => AnyEvent::Impl::Perl::],
1197	# everything below here will not (normally) be autoprobed	1351	# everything below here will not (normally) be autoprobed
1198	# as the pureperl backend should work everywhere	1352	# as the pure perl backend should work everywhere
1199	# 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
1200	[Event:: => AnyEvent::Impl::Event::, 1],	1355	[Event:: => AnyEvent::Impl::Event::], # slow, stable
1201	[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
1202	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy	1358	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
1203	[Irssi:: => AnyEvent::Impl::Irssi::], # Irssi has a bogus "Event" package
1204	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles	1359	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
1205	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program	1360	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program
1206	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza	1361	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
1207	[Wx:: => AnyEvent::Impl::POE::],	1362	[Wx:: => AnyEvent::Impl::POE::],
1208	[Prima:: => AnyEvent::Impl::POE::],	1363	[Prima:: => AnyEvent::Impl::POE::],
1209	# IO::Async is just too broken - we would need workarounds for its	1364	[IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # a bitch to autodetect
1210	# byzantine signal and broken child handling, among others.	1365	[Cocoa::EventLoop:: => AnyEvent::Impl::Cocoa::],
1211	# IO::Async is rather hard to detect, as it doesn't have any	1366	[FLTK:: => AnyEvent::Impl::FLTK::],
1212	# obvious default class.
1213	[IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program
1214	[IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program
1215	[IO::Async::Notifier:: => AnyEvent::Impl::IOAsync::], # requires special main program
1216	[AnyEvent::Impl::IOAsync:: => AnyEvent::Impl::IOAsync::], # requires special main program
1217	);	1367	);
1218		1368
1219	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, $reset_ae] : undef;
		1386
		1387	_isa_set;
		1388	}
		1389
		1390	# all autoloaded methods reserve the complete glob, not just the method slot.
		1391	# due to bugs in perls method cache implementation.
1220	qw(io timer time now now_update signal child idle condvar one_event DESTROY);	1392	our @methods = qw(io timer time now now_update signal child idle condvar);
1221
1222	our @post_detect;
1223
1224	sub post_detect(&) {
1225	my ($cb) = @_;
1226
1227	if ($MODEL) {
1228	$cb->();
1229
1230	undef
1231	} else {
1232	push @post_detect, $cb;
1233
1234	defined wantarray
1235	? bless \$cb, "AnyEvent::Util::postdetect"
1236	: ()
1237	}
1238	}
1239
1240	sub AnyEvent::Util::postdetect::DESTROY {
1241	@post_detect = grep $_ != ${$_[0]}, @post_detect;
1242	}
1243		1393
1244	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
1245	# free some memory	1408	# free some memory
1246	*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;
1247		1417
1248	local $!; # for good measure
1249	local $SIG{__DIE__};
1250
1251	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {	1418	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z0-9:]+)$/) {
1252	my $model = "AnyEvent::Impl::$1";	1419	my $model = $1;
		1420	$model = "AnyEvent::Impl::$model" unless $model =~ s/::$//;
1253	if (eval "require $model") {	1421	if (eval "require $model") {
		1422	AnyEvent::log 7 => "Loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.";
1254	$MODEL = $model;	1423	$MODEL = $model;
1255	warn "AnyEvent: loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.\n" if $VERBOSE >= 2;
1256	} else {	1424	} else {
1257	warn "AnyEvent: unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@" if $VERBOSE;	1425	AnyEvent::log 4 => "Unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@";
1258	}	1426	}
1259	}	1427	}
1260		1428
1261	# check for already loaded models	1429	# check for already loaded models
1262	unless ($MODEL) {	1430	unless ($MODEL) {
1263	for (@REGISTRY, @models) {	1431	for (@REGISTRY, @models) {
1264	my ($package, $model) = @$_;	1432	my ($package, $model) = @$_;
1265	if (${"$package\::VERSION"} > 0) {	1433	if (${"$package\::VERSION"} > 0) {
1266	if (eval "require $model") {	1434	if (eval "require $model") {
		1435	AnyEvent::log 7 => "Autodetected model '$model', using it.";
1267	$MODEL = $model;	1436	$MODEL = $model;
1268	warn "AnyEvent: autodetected model '$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 = $model;
1269	last;	1455	last;
1270	}	1456	}
1271	}	1457	}
1272	}
1273
1274	unless ($MODEL) {
1275	# try to autoload a model
1276	for (@REGISTRY, @models) {
1277	my ($package, $model, $autoload) = @$_;
1278	if (
1279	$autoload
1280	and eval "require $package"
1281	and ${"$package\::VERSION"} > 0
1282	and eval "require $model"
1283	) {
1284	$MODEL = $model;
1285	warn "AnyEvent: autoloaded model '$model', using it.\n" if $VERBOSE >= 2;
1286	last;
1287	}
1288	}
1289		1458
1290	$MODEL	1459	$MODEL
1291	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.\n";	1460	or AnyEvent::log fatal => "Backend autodetection failed - did you properly install AnyEvent?";
1292	}	1461	}
1293	}	1462	}
1294		1463
1295	@models = (); # free probe data	1464	# free memory only needed for probing
		1465	undef @models;
		1466	undef @REGISTRY;
1296		1467
1297	push @{"$MODEL\::ISA"}, "AnyEvent::Base";	1468	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
1298	unshift @ISA, $MODEL;
1299		1469
1300	require AnyEvent::Strict if $ENV{PERL_ANYEVENT_STRICT};	1470	# now nuke some methods that are overridden by the backend.
		1471	# SUPER usage is not allowed in these.
		1472	for (qw(time signal child idle)) {
		1473	undef &{"AnyEvent::Base::$_"}
		1474	if defined &{"$MODEL\::$_"};
		1475	}
		1476
		1477	_isa_set;
		1478
		1479	# we're officially open!
		1480
		1481	if ($ENV{PERL_ANYEVENT_STRICT}) {
		1482	require AnyEvent::Strict;
		1483	}
		1484
		1485	if ($ENV{PERL_ANYEVENT_DEBUG_WRAP}) {
		1486	require AnyEvent::Debug;
		1487	AnyEvent::Debug::wrap ($ENV{PERL_ANYEVENT_DEBUG_WRAP});
		1488	}
		1489
		1490	if (length $ENV{PERL_ANYEVENT_DEBUG_SHELL}) {
		1491	require AnyEvent::Socket;
		1492	require AnyEvent::Debug;
		1493
		1494	my $shell = $ENV{PERL_ANYEVENT_DEBUG_SHELL};
		1495	$shell =~ s/\$\$/$$/g;
		1496
		1497	my ($host, $service) = AnyEvent::Socket::parse_hostport ($shell);
		1498	$AnyEvent::Debug::SHELL = AnyEvent::Debug::shell ($host, $service);
		1499	}
		1500
		1501	# now the anyevent environment is set up as the user told us to, so
		1502	# call the actual user code - post detects
1301		1503
1302	(shift @post_detect)->() while @post_detect;	1504	(shift @post_detect)->() while @post_detect;
		1505	undef @post_detect;
		1506
		1507	*post_detect = sub(&) {
		1508	shift->();
		1509
		1510	undef
		1511	};
1303		1512
1304	$MODEL	1513	$MODEL
1305	}	1514	}
1306		1515
1307	sub AUTOLOAD {	1516	for my $name (@methods) {
1308	(my $func = $AUTOLOAD) =~ s/.*://;	1517	*$name = sub {
1309
1310	$method{$func}
1311	or Carp::croak "$func: not a valid AnyEvent class method";
1312
1313	detect;	1518	detect;
1314		1519	# we use goto because
1315	my $class = shift;	1520	# a) it makes the thunk more transparent
1316	$class->$func (@_);	1521	# b) it allows us to delete the thunk later
		1522	goto &{ UNIVERSAL::can AnyEvent => "SUPER::$name" }
		1523	};
1317	}	1524	}
1318		1525
1319	# 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
1320	# to support binding more than one watcher per filehandle (they usually	1527	# to support binding more than one watcher per filehandle (they usually
1321	# 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).
…		…
1335		1542
1336	=head1 SIMPLIFIED AE API	1543	=head1 SIMPLIFIED AE API
1337		1544
1338	Starting with version 5.0, AnyEvent officially supports a second, much	1545	Starting with version 5.0, AnyEvent officially supports a second, much
1339	simpler, API that is designed to reduce the calling, typing and memory	1546	simpler, API that is designed to reduce the calling, typing and memory
1340	overhead.	1547	overhead by using function call syntax and a fixed number of parameters.
1341		1548
1342	See the L<AE> manpage for details.	1549	See the L<AE> manpage for details.
1343		1550
1344	=cut	1551	=cut
1345		1552
1346	package AE;	1553	package AE;
1347		1554
1348	our $VERSION = $AnyEvent::VERSION;	1555	our $VERSION = $AnyEvent::VERSION;
1349		1556
		1557	sub _reset() {
		1558	eval q{
		1559	# fall back to the main API by default - backends and AnyEvent::Base
		1560	# implementations can overwrite these.
		1561
1350	sub io($$$) {	1562	sub io($$$) {
1351	AnyEvent->io (fh => $_[0], poll => $_[1] ? "w" : "r", cb => $_[2])	1563	AnyEvent->io (fh => $_[0], poll => $_[1] ? "w" : "r", cb => $_[2])
1352	}	1564	}
1353		1565
1354	sub timer($$$) {	1566	sub timer($$$) {
1355	AnyEvent->timer (after => $_[0], interval => $_[1], cb => $_[2])	1567	AnyEvent->timer (after => $_[0], interval => $_[1], cb => $_[2])
1356	}	1568	}
1357		1569
1358	sub signal($$) {	1570	sub signal($$) {
1359	AnyEvent->signal (signal => $_[0], cb => $_[1])	1571	AnyEvent->signal (signal => $_[0], cb => $_[1])
1360	}	1572	}
1361		1573
1362	sub child($$) {	1574	sub child($$) {
1363	AnyEvent->child (pid => $_[0], cb => $_[1])	1575	AnyEvent->child (pid => $_[0], cb => $_[1])
1364	}	1576	}
1365		1577
1366	sub idle($) {	1578	sub idle($) {
1367	AnyEvent->idle (cb => $_[0])	1579	AnyEvent->idle (cb => $_[0]);
1368	}	1580	}
1369		1581
1370	sub cv(;&) {	1582	sub cv(;&) {
1371	AnyEvent->condvar (@_ ? (cb => $_[0]) : ())	1583	AnyEvent->condvar (@_ ? (cb => $_[0]) : ())
1372	}	1584	}
1373		1585
1374	sub now() {	1586	sub now() {
1375	AnyEvent->now	1587	AnyEvent->now
1376	}	1588	}
1377		1589
1378	sub now_update() {	1590	sub now_update() {
1379	AnyEvent->now_update	1591	AnyEvent->now_update
1380	}	1592	}
1381		1593
1382	sub time() {	1594	sub time() {
1383	AnyEvent->time	1595	AnyEvent->time
		1596	}
		1597
		1598	*postpone = \&AnyEvent::postpone;
		1599	*log = \&AnyEvent::log;
		1600	};
		1601	die if $@;
1384	}	1602	}
		1603
		1604	BEGIN { _reset }
1385		1605
1386	package AnyEvent::Base;	1606	package AnyEvent::Base;
1387		1607
1388	# default implementations for many methods	1608	# default implementations for many methods
1389		1609
1390	sub _time() {	1610	sub time {
1391	eval q{ # poor man's autoloading	1611	eval q{ # poor man's autoloading {}
1392	# probe for availability of Time::HiRes	1612	# probe for availability of Time::HiRes
1393	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {	1613	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {
1394	warn "AnyEvent: using Time::HiRes for sub-second timing accuracy.\n" if $VERBOSE >= 8;	1614	*time = sub { Time::HiRes::time () };
1395	*_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.";
1396	# if (eval "use POSIX (); (POSIX::times())...	1618	# if (eval "use POSIX (); (POSIX::times())...
1397	} else {	1619	} else {
		1620	*time = sub { CORE::time };
		1621	*AE::time = sub (){ CORE::time };
		1622	*now = \&time;
1398	warn "AnyEvent: using built-in time(), WARNING, no sub-second resolution!\n" if $VERBOSE;	1623	AnyEvent::log 3 => "Using built-in time(), no sub-second resolution!";
1399	*_time = sub (){ time }; # epic fail
1400	}	1624	}
1401	};	1625	};
1402	die if $@;	1626	die if $@;
1403		1627
1404	&_time	1628	&time
1405	}	1629	}
1406		1630
1407	sub time { _time }	1631	*now = \&time;
1408	sub now { _time }
1409	sub now_update { }	1632	sub now_update { }
1410		1633
		1634	sub _poll {
		1635	Carp::croak "$AnyEvent::MODEL does not support blocking waits. Caught";
		1636	}
		1637
1411	# default implementation for ->condvar	1638	# default implementation for ->condvar
		1639	# in fact, the default should not be overwritten
1412		1640
1413	sub condvar {	1641	sub condvar {
		1642	eval q{ # poor man's autoloading {}
		1643	*condvar = sub {
1414	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"	1644	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"
		1645	};
		1646
		1647	*AE::cv = sub (;&) {
		1648	bless { @_ ? (_ae_cb => shift) : () }, "AnyEvent::CondVar"
		1649	};
		1650	};
		1651	die if $@;
		1652
		1653	&condvar
1415	}	1654	}
1416		1655
1417	# default implementation for ->signal	1656	# default implementation for ->signal
1418		1657
1419	our $HAVE_ASYNC_INTERRUPT;	1658	our $HAVE_ASYNC_INTERRUPT;
…		…
1449	undef $SIG_TW	1688	undef $SIG_TW
1450	unless --$SIG_COUNT;	1689	unless --$SIG_COUNT;
1451	}	1690	}
1452		1691
1453	our $_sig_name_init; $_sig_name_init = sub {	1692	our $_sig_name_init; $_sig_name_init = sub {
1454	eval q{ # poor man's autoloading	1693	eval q{ # poor man's autoloading {}
1455	undef $_sig_name_init;	1694	undef $_sig_name_init;
1456		1695
1457	if (_have_async_interrupt) {	1696	if (_have_async_interrupt) {
1458	*sig2num = \&Async::Interrupt::sig2num;	1697	*sig2num = \&Async::Interrupt::sig2num;
1459	*sig2name = \&Async::Interrupt::sig2name;	1698	*sig2name = \&Async::Interrupt::sig2name;
…		…
1483		1722
1484	sub signal {	1723	sub signal {
1485	eval q{ # poor man's autoloading {}	1724	eval q{ # poor man's autoloading {}
1486	# probe for availability of Async::Interrupt	1725	# probe for availability of Async::Interrupt
1487	if (_have_async_interrupt) {	1726	if (_have_async_interrupt) {
1488	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.";
1489		1728
1490	$SIGPIPE_R = new Async::Interrupt::EventPipe;	1729	$SIGPIPE_R = new Async::Interrupt::EventPipe;
1491	$SIG_IO = AE::io $SIGPIPE_R->fileno, 0, \&_signal_exec;	1730	$SIG_IO = AE::io $SIGPIPE_R->fileno, 0, \&_signal_exec;
1492		1731
1493	} else {	1732	} else {
1494	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.";
1495		1734
1496	if (AnyEvent::WIN32) {	1735	if (AnyEvent::WIN32) {
1497	require AnyEvent::Util;	1736	require AnyEvent::Util;
1498		1737
1499	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();	1738	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
…		…
1513	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";	1752	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";
1514		1753
1515	$SIG_IO = AE::io $SIGPIPE_R, 0, \&_signal_exec;	1754	$SIG_IO = AE::io $SIGPIPE_R, 0, \&_signal_exec;
1516	}	1755	}
1517		1756
1518	*signal = sub {	1757	*signal = $HAVE_ASYNC_INTERRUPT
		1758	? sub {
1519	my (undef, %arg) = @_;	1759	my (undef, %arg) = @_;
1520		1760
1521	my $signal = uc $arg{signal}
1522	or Carp::croak "required option 'signal' is missing";
1523
1524	if ($HAVE_ASYNC_INTERRUPT) {
1525	# async::interrupt	1761	# async::interrupt
1526
1527	$signal = sig2num $signal;	1762	my $signal = sig2num $arg{signal};
1528	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};	1763	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
1529		1764
1530	$SIG_ASY{$signal} ||= new Async::Interrupt	1765	$SIG_ASY{$signal} ||= new Async::Interrupt
1531	cb => sub { undef $SIG_EV{$signal} },	1766	cb => sub { undef $SIG_EV{$signal} },
1532	signal => $signal,	1767	signal => $signal,
1533	pipe => [$SIGPIPE_R->filenos],	1768	pipe => [$SIGPIPE_R->filenos],
1534	pipe_autodrain => 0,	1769	pipe_autodrain => 0,
1535	;	1770	;
1536		1771
1537	} else {	1772	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
		1773	}
		1774	: sub {
		1775	my (undef, %arg) = @_;
		1776
1538	# pure perl	1777	# pure perl
1539
1540	# AE::Util has been loaded in signal
1541	$signal = sig2name $signal;	1778	my $signal = sig2name $arg{signal};
1542	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};	1779	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
1543		1780
1544	$SIG{$signal} ||= sub {	1781	$SIG{$signal} ||= sub {
1545	local $!;	1782	local $!;
1546	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;	1783	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;
1547	undef $SIG_EV{$signal};	1784	undef $SIG_EV{$signal};
1548	};	1785	};
1549		1786
1550	# can't do signal processing without introducing races in pure perl,	1787	# can't do signal processing without introducing races in pure perl,
1551	# so limit the signal latency.	1788	# so limit the signal latency.
1552	_sig_add;	1789	_sig_add;
1553	}
1554		1790
1555	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"	1791	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
		1792	}
1556	};	1793	;
1557		1794
1558	*AnyEvent::Base::signal::DESTROY = sub {	1795	*AnyEvent::Base::signal::DESTROY = sub {
1559	my ($signal, $cb) = @{$_[0]};	1796	my ($signal, $cb) = @{$_[0]};
1560		1797
1561	_sig_del;	1798	_sig_del;
…		…
1577	: sysread $SIGPIPE_R, (my $dummy), 9;	1814	: sysread $SIGPIPE_R, (my $dummy), 9;
1578		1815
1579	while (%SIG_EV) {	1816	while (%SIG_EV) {
1580	for (keys %SIG_EV) {	1817	for (keys %SIG_EV) {
1581	delete $SIG_EV{$_};	1818	delete $SIG_EV{$_};
1582	$_->() for values %{ $SIG_CB{$_} || {} };	1819	&$_ for values %{ $SIG_CB{$_} || {} };
1583	}	1820	}
1584	}	1821	}
1585	};	1822	};
1586	};	1823	};
1587	die if $@;	1824	die if $@;
…		…
1592	# default implementation for ->child	1829	# default implementation for ->child
1593		1830
1594	our %PID_CB;	1831	our %PID_CB;
1595	our $CHLD_W;	1832	our $CHLD_W;
1596	our $CHLD_DELAY_W;	1833	our $CHLD_DELAY_W;
1597	our $WNOHANG;
1598		1834
1599	# used by many Impl's	1835	# used by many Impl's
1600	sub _emit_childstatus($$) {	1836	sub _emit_childstatus($$) {
1601	my (undef, $rpid, $rstatus) = @_;	1837	my (undef, $rpid, $rstatus) = @_;
1602		1838
…		…
1609	eval q{ # poor man's autoloading {}	1845	eval q{ # poor man's autoloading {}
1610	*_sigchld = sub {	1846	*_sigchld = sub {
1611	my $pid;	1847	my $pid;
1612		1848
1613	AnyEvent->_emit_childstatus ($pid, $?)	1849	AnyEvent->_emit_childstatus ($pid, $?)
1614	while ($pid = waitpid -1, $WNOHANG) > 0;	1850	while ($pid = waitpid -1, WNOHANG) > 0;
1615	};	1851	};
1616		1852
1617	*child = sub {	1853	*child = sub {
1618	my (undef, %arg) = @_;	1854	my (undef, %arg) = @_;
1619		1855
1620	defined (my $pid = $arg{pid} + 0)	1856	my $pid = $arg{pid};
1621	or Carp::croak "required option 'pid' is missing";	1857	my $cb = $arg{cb};
1622		1858
1623	$PID_CB{$pid}{$arg{cb}} = $arg{cb};	1859	$PID_CB{$pid}{$cb+0} = $cb;
1624
1625	# WNOHANG is almost cetrainly 1 everywhere
1626	$WNOHANG ||= $^O =~ /^(?:openbsd|netbsd|linux|freebsd|cygwin|MSWin32)$/
1627	? 1
1628	: eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1;
1629		1860
1630	unless ($CHLD_W) {	1861	unless ($CHLD_W) {
1631	$CHLD_W = AE::signal CHLD => \&_sigchld;	1862	$CHLD_W = AE::signal CHLD => \&_sigchld;
1632	# 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
1633	&_sigchld;	1864	&_sigchld;
1634	}	1865	}
1635		1866
1636	bless [$pid, $arg{cb}], "AnyEvent::Base::child"	1867	bless [$pid, $cb+0], "AnyEvent::Base::child"
1637	};	1868	};
1638		1869
1639	*AnyEvent::Base::child::DESTROY = sub {	1870	*AnyEvent::Base::child::DESTROY = sub {
1640	my ($pid, $cb) = @{$_[0]};	1871	my ($pid, $icb) = @{$_[0]};
1641		1872
1642	delete $PID_CB{$pid}{$cb};	1873	delete $PID_CB{$pid}{$icb};
1643	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };	1874	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };
1644		1875
1645	undef $CHLD_W unless keys %PID_CB;	1876	undef $CHLD_W unless keys %PID_CB;
1646	};	1877	};
1647	};	1878	};
…		…
1660		1891
1661	my ($cb, $w, $rcb) = $arg{cb};	1892	my ($cb, $w, $rcb) = $arg{cb};
1662		1893
1663	$rcb = sub {	1894	$rcb = sub {
1664	if ($cb) {	1895	if ($cb) {
1665	$w = _time;	1896	$w = AE::time;
1666	&$cb;	1897	&$cb;
1667	$w = _time - $w;	1898	$w = AE::time - $w;
1668		1899
1669	# 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,
1670	# within some limits	1901	# within some limits
1671	$w = 0.0001 if $w < 0.0001;	1902	$w = 0.0001 if $w < 0.0001;
1672	$w = 5 if $w > 5;	1903	$w = 5 if $w > 5;
…		…
1695		1926
1696	package AnyEvent::CondVar;	1927	package AnyEvent::CondVar;
1697		1928
1698	our @ISA = AnyEvent::CondVar::Base::;	1929	our @ISA = AnyEvent::CondVar::Base::;
1699		1930
		1931	# only to be used for subclassing
		1932	sub new {
		1933	my $class = shift;
		1934	bless AnyEvent->condvar (@_), $class
		1935	}
		1936
1700	package AnyEvent::CondVar::Base;	1937	package AnyEvent::CondVar::Base;
1701		1938
1702	#use overload	1939	#use overload
1703	# '&{}' => sub { my $self = shift; sub { $self->send (@_) } },	1940	# '&{}' => sub { my $self = shift; sub { $self->send (@_) } },
1704	# fallback => 1;	1941	# fallback => 1;
…		…
1713		1950
1714	sub _send {	1951	sub _send {
1715	# nop	1952	# nop
1716	}	1953	}
1717		1954
		1955	sub _wait {
		1956	AnyEvent->_poll until $_[0]{_ae_sent};
		1957	}
		1958
1718	sub send {	1959	sub send {
1719	my $cv = shift;	1960	my $cv = shift;
1720	$cv->{_ae_sent} = [@_];	1961	$cv->{_ae_sent} = [@_];
1721	(delete $cv->{_ae_cb})->($cv) if $cv->{_ae_cb};	1962	(delete $cv->{_ae_cb})->($cv) if $cv->{_ae_cb};
1722	$cv->_send;	1963	$cv->_send;
…		…
1729		1970
1730	sub ready {	1971	sub ready {
1731	$_[0]{_ae_sent}	1972	$_[0]{_ae_sent}
1732	}	1973	}
1733		1974
1734	sub _wait {
1735	$WAITING
1736	and !$_[0]{_ae_sent}
1737	and Carp::croak "AnyEvent::CondVar: recursive blocking wait detected";
1738
1739	local $WAITING = 1;
1740	AnyEvent->one_event while !$_[0]{_ae_sent};
1741	}
1742
1743	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;
1744	$_[0]->_wait;	1981	$_[0]->_wait;
		1982	}
1745		1983
1746	Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak};	1984	$_[0]{_ae_croak}
1747	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]
1748	}	1990	}
1749		1991
1750	sub cb {	1992	sub cb {
1751	my $cv = shift;	1993	my $cv = shift;
1752		1994
…		…
1768	&{ $_[0]{_ae_end_cb} || sub { $_[0]->send } };	2010	&{ $_[0]{_ae_end_cb} || sub { $_[0]->send } };
1769	}	2011	}
1770		2012
1771	# undocumented/compatibility with pre-3.4	2013	# undocumented/compatibility with pre-3.4
1772	*broadcast = \&send;	2014	*broadcast = \&send;
1773	*wait = \&_wait;	2015	*wait = \&recv;
1774		2016
1775	=head1 ERROR AND EXCEPTION HANDLING	2017	=head1 ERROR AND EXCEPTION HANDLING
1776		2018
1777	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
1778	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
…		…
1790	$Event/EV::DIED->() >>, L<Glib> uses C<< install_exception_handler >> and	2032	$Event/EV::DIED->() >>, L<Glib> uses C<< install_exception_handler >> and
1791	so on.	2033	so on.
1792		2034
1793	=head1 ENVIRONMENT VARIABLES	2035	=head1 ENVIRONMENT VARIABLES
1794		2036
1795	The following environment variables are used by this module or its	2037	AnyEvent supports a number of environment variables that tune the
1796	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.
1797		2043
1798	Note that AnyEvent will remove I<all> environment variables starting with	2044	All the environment variables documented here start with
1799	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
1800	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:
1801		2074
1802	=over 4	2075	=over 4
1803		2076
1804	=item C<PERL_ANYEVENT_VERBOSE>	2077	=item C<PERL_ANYEVENT_VERBOSE>
1805		2078
1806	By default, AnyEvent will be completely silent except in fatal	2079	By default, AnyEvent will log messages with loglevel C<4> (C<error>) or
1807	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
1808	talkative.	2081	numerical loglevel to make AnyEvent more (or less) talkative.
1809		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
1810	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
1811	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
1812	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.
1813		2094
1814	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
1815	model it chooses.	2096	chooses.
1816		2097
1817	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
1818	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.
1819		2119
1820	=item C<PERL_ANYEVENT_STRICT>	2120	=item C<PERL_ANYEVENT_STRICT>
1821		2121
1822	AnyEvent does not do much argument checking by default, as thorough	2122	AnyEvent does not do much argument checking by default, as thorough
1823	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
…		…
1825	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,
1826	it will croak.	2126	it will croak.
1827		2127
1828	In other words, enables "strict" mode.	2128	In other words, enables "strict" mode.
1829		2129
1830	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>
1831	>>, it is definitely recommended to keep it off in production. Keeping	2131	>>, it is definitely recommended to keep it off in production. Keeping
1832	C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs	2132	C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs
1833	can be very useful, however.	2133	can be very useful, however.
1834		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
1835	=item C<PERL_ANYEVENT_MODEL>	2163	=item C<PERL_ANYEVENT_MODEL>
1836		2164
1837	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
1838	auto detection and -probing kicks in. It must be a string consisting	2166	auto detection and -probing kicks in.
1839	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
1840	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
1841	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
1842	auto detection and -probing.	2172	auto detection and -probing.
1843		2173
1844	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).
1845		2177
1846	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
1847	could start your program like this:	2179	could start your program like this:
1848		2180
1849	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>.
1850		2190
1851	=item C<PERL_ANYEVENT_PROTOCOLS>	2191	=item C<PERL_ANYEVENT_PROTOCOLS>
1852		2192
1853	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
1854	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
…		…
1867	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>
1868	- only support IPv4, never try to resolve or contact IPv6	2208	- only support IPv4, never try to resolve or contact IPv6
1869	addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or	2209	addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or
1870	IPv6, but prefer IPv6 over IPv4.	2210	IPv6, but prefer IPv6 over IPv4.
1871		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
1872	=item C<PERL_ANYEVENT_EDNS0>	2218	=item C<PERL_ANYEVENT_EDNS0>
1873		2219
1874	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
1875	for DNS. This extension is generally useful to reduce DNS traffic, but	2221	DNS. This extension is generally useful to reduce DNS traffic, especially
1876	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
1877	default.	2223	packets, which is why it is off by default.
1878		2224
1879	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
1880	EDNS0 in its DNS requests.	2226	EDNS0 in its DNS requests.
1881		2227
1882	=item C<PERL_ANYEVENT_MAX_FORKS>	2228	=item C<PERL_ANYEVENT_MAX_FORKS>
…		…
1888		2234
1889	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
1890	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
1891	sent to the DNS server.	2237	sent to the DNS server.
1892		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
1893	=item C<PERL_ANYEVENT_RESOLV_CONF>	2261	=item C<PERL_ANYEVENT_RESOLV_CONF>
1894		2262
1895	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
1896	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
1897	default config will be used.	2265	resolver, or the empty string to select the default configuration.
1898		2266
1899	=item C<PERL_ANYEVENT_CA_FILE>, C<PERL_ANYEVENT_CA_PATH>.	2267	=item C<PERL_ANYEVENT_CA_FILE>, C<PERL_ANYEVENT_CA_PATH>.
1900		2268
1901	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
1902	L<AnyEvent::TLS> context creation, and either of these environment	2270	L<AnyEvent::TLS> context creation, and either of these environment
1903	variables exist, they will be used to specify CA certificate locations	2271	variables are nonempty, they will be used to specify CA certificate
1904	instead of a system-dependent default.	2272	locations instead of a system-dependent default.
1905		2273
1906	=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>
1907		2275
1908	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
1909	loaded. Mostly good for testing AnyEvent itself.	2277	loaded. Mostly good for testing AnyEvent itself.
…		…
2057		2425
2058	The actual code goes further and collects all errors (C<die>s, exceptions)	2426	The actual code goes further and collects all errors (C<die>s, exceptions)
2059	that occurred during request processing. The C<result> method detects	2427	that occurred during request processing. The C<result> method detects
2060	whether an exception as thrown (it is stored inside the $txn object)	2428	whether an exception as thrown (it is stored inside the $txn object)
2061	and just throws the exception, which means connection errors and other	2429	and just throws the exception, which means connection errors and other
2062	problems get reported tot he code that tries to use the result, not in a	2430	problems get reported to the code that tries to use the result, not in a
2063	random callback.	2431	random callback.
2064		2432
2065	All of this enables the following usage styles:	2433	All of this enables the following usage styles:
2066		2434
2067	1. Blocking:	2435	1. Blocking:
…		…
2241	(even when used without AnyEvent), but most event loops have acceptable	2609	(even when used without AnyEvent), but most event loops have acceptable
2242	performance with or without AnyEvent.	2610	performance with or without AnyEvent.
2243		2611
2244	=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
2245	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
2246	adds AnyEvent significant overhead.	2614	does AnyEvent add significant overhead.
2247		2615
2248	=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
2249	reasonable memory usage.	2617	reasonable memory usage.
2250		2618
2251	=back	2619	=back
…		…
2481	unless defined $SIG{PIPE};	2849	unless defined $SIG{PIPE};
2482		2850
2483	=head1 RECOMMENDED/OPTIONAL MODULES	2851	=head1 RECOMMENDED/OPTIONAL MODULES
2484		2852
2485	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
2486	it's built-in modules) are required to use it.	2854	its built-in modules) are required to use it.
2487		2855
2488	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
2489	modules if they are installed.	2857	modules if they are installed.
2490		2858
2491	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
…		…
2524	automatic timer adjustments even when no monotonic clock is available,	2892	automatic timer adjustments even when no monotonic clock is available,
2525	can take avdantage of advanced kernel interfaces such as C<epoll> and	2893	can take avdantage of advanced kernel interfaces such as C<epoll> and
2526	C<kqueue>, and is the fastest backend I<by far>. You can even embed	2894	C<kqueue>, and is the fastest backend I<by far>. You can even embed
2527	L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>).	2895	L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>).
2528		2896
		2897	If you only use backends that rely on another event loop (e.g. C<Tk>),
		2898	then this module will do nothing for you.
		2899
2529	=item L<Guard>	2900	=item L<Guard>
2530		2901
2531	The guard module, when used, will be used to implement	2902	The guard module, when used, will be used to implement
2532	C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a	2903	C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a
2533	lot less memory), but otherwise doesn't affect guard operation much. It is	2904	lot less memory), but otherwise doesn't affect guard operation much. It is
2534	purely used for performance.	2905	purely used for performance.
2535		2906
2536	=item L<JSON> and L<JSON::XS>	2907	=item L<JSON> and L<JSON::XS>
2537		2908
2538	One of these modules is required when you want to read or write JSON data	2909	One of these modules is required when you want to read or write JSON data
2539	via L<AnyEvent::Handle>. It is also written in pure-perl, but can take	2910	via L<AnyEvent::Handle>. L<JSON> is also written in pure-perl, but can take
2540	advantage of the ultra-high-speed L<JSON::XS> module when it is installed.	2911	advantage of the ultra-high-speed L<JSON::XS> module when it is installed.
2541
2542	In fact, L<AnyEvent::Handle> will use L<JSON::XS> by default if it is
2543	installed.
2544		2912
2545	=item L<Net::SSLeay>	2913	=item L<Net::SSLeay>
2546		2914
2547	Implementing TLS/SSL in Perl is certainly interesting, but not very	2915	Implementing TLS/SSL in Perl is certainly interesting, but not very
2548	worthwhile: If this module is installed, then L<AnyEvent::Handle> (with	2916	worthwhile: If this module is installed, then L<AnyEvent::Handle> (with
2549	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.
2550		2918
2551	=item L<Time::HiRes>	2919	=item L<Time::HiRes>
2552		2920
2553	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
2554	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
2555	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
2556	try to use a monotonic clock for timing stability.	2924	try to use a monotonic clock for timing stability.
2557		2925
2558	=back	2926	=back
2559		2927
2560		2928
…		…
2622	pronounced).	2990	pronounced).
2623		2991
2624		2992
2625	=head1 SEE ALSO	2993	=head1 SEE ALSO
2626		2994
2627	Utility functions: L<AnyEvent::Util>.	2995	Tutorial/Introduction: L<AnyEvent::Intro>.
2628		2996
2629	Event modules: L<EV>, L<EV::Glib>, L<Glib::EV>, L<Event>, L<Glib::Event>,	2997	FAQ: L<AnyEvent::FAQ>.
2630	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>.
2631		3008
2632	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,	3009	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,
2633	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>,
2634	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,	3011	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,
2635	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>.
2636		3014
2637	Non-blocking file handles, sockets, TCP clients and	3015	Non-blocking handles, pipes, stream sockets, TCP clients and
2638	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.	3016	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.
2639		3017
		3018	Asynchronous File I/O: L<AnyEvent::IO>.
		3019
2640	Asynchronous DNS: L<AnyEvent::DNS>.	3020	Asynchronous DNS: L<AnyEvent::DNS>.
2641		3021
2642	Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>,	3022	Thread support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>.
2643	L<Coro::Event>,
2644		3023
2645	Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::XMPP>,	3024	Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::IRC>,
2646	L<AnyEvent::HTTP>.	3025	L<AnyEvent::HTTP>.
2647		3026
2648		3027
2649	=head1 AUTHOR	3028	=head1 AUTHOR
2650		3029
2651	Marc Lehmann <schmorp@schmorp.de>	3030	Marc Lehmann <schmorp@schmorp.de>
2652	http://home.schmorp.de/	3031	http://anyevent.schmorp.de
2653		3032
2654	=cut	3033	=cut
2655		3034
2656	1	3035	1
2657		3036

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