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Revision 1.409 by root, Thu Dec 6 12:10:09 2012 UTC

1	=head1 NAME	1	=head1 NAME
2		2
3	AnyEvent - the DBI of event loop programming	3	AnyEvent - the DBI of event loop programming
4		4
5	EV, Event, Glib, Tk, Perl, Event::Lib, Irssi, rxvt-unicode, IO::Async, Qt	5	EV, Event, Glib, Tk, Perl, Event::Lib, Irssi, rxvt-unicode, IO::Async, Qt,
6	and POE are various supported event loops/environments.	6	FLTK and POE are various supported event loops/environments.
7		7
8	=head1 SYNOPSIS	8	=head1 SYNOPSIS
9		9
10	use AnyEvent;	10	use AnyEvent;
11		11
…		…
15	# file handle or descriptor readable	15	# file handle or descriptor readable
16	my $w = AnyEvent->io (fh => $fh, poll => "r", cb => sub { ... });	16	my $w = AnyEvent->io (fh => $fh, poll => "r", cb => sub { ... });
17		17
18	# one-shot or repeating timers	18	# one-shot or repeating timers
19	my $w = AnyEvent->timer (after => $seconds, cb => sub { ... });	19	my $w = AnyEvent->timer (after => $seconds, cb => sub { ... });
20	my $w = AnyEvent->timer (after => $seconds, interval => $seconds, cb => ...	20	my $w = AnyEvent->timer (after => $seconds, interval => $seconds, cb => ...);
21		21
22	print AnyEvent->now; # prints current event loop time	22	print AnyEvent->now; # prints current event loop time
23	print AnyEvent->time; # think Time::HiRes::time or simply CORE::time.	23	print AnyEvent->time; # think Time::HiRes::time or simply CORE::time.
24		24
25	# POSIX signal	25	# POSIX signal
…		…
46	in a tutorial or some gentle introduction, have a look at the	46	in a tutorial or some gentle introduction, have a look at the
47	L<AnyEvent::Intro> manpage.	47	L<AnyEvent::Intro> manpage.
48		48
49	=head1 SUPPORT	49	=head1 SUPPORT
50		50
		51	An FAQ document is available as L<AnyEvent::FAQ>.
		52
51	There is a mailinglist for discussing all things AnyEvent, and an IRC	53	There also is a mailinglist for discussing all things AnyEvent, and an IRC
52	channel, too.	54	channel, too.
53		55
54	See the AnyEvent project page at the B<Schmorpforge Ta-Sa Software	56	See the AnyEvent project page at the B<Schmorpforge Ta-Sa Software
55	Repository>, at L<http://anyevent.schmorp.de>, for more info.	57	Repository>, at L<http://anyevent.schmorp.de>, for more info.
56		58
…		…
76	module users into the same thing by forcing them to use the same event	78	module users into the same thing by forcing them to use the same event
77	model you use.	79	model you use.
78		80
79	For modules like POE or IO::Async (which is a total misnomer as it is	81	For modules like POE or IO::Async (which is a total misnomer as it is
80	actually doing all I/O I<synchronously>...), using them in your module is	82	actually doing all I/O I<synchronously>...), using them in your module is
81	like joining a cult: After you joined, you are dependent on them and you	83	like joining a cult: After you join, you are dependent on them and you
82	cannot use anything else, as they are simply incompatible to everything	84	cannot use anything else, as they are simply incompatible to everything
83	that isn't them. What's worse, all the potential users of your	85	that isn't them. What's worse, all the potential users of your
84	module are I<also> forced to use the same event loop you use.	86	module are I<also> forced to use the same event loop you use.
85		87
86	AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works	88	AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works
87	fine. AnyEvent + Tk works fine etc. etc. but none of these work together	89	fine. AnyEvent + Tk works fine etc. etc. but none of these work together
88	with the rest: POE + IO::Async? No go. Tk + Event? No go. Again: if	90	with the rest: POE + EV? No go. Tk + Event? No go. Again: if your module
89	your module uses one of those, every user of your module has to use it,	91	uses one of those, every user of your module has to use it, too. But if
90	too. But if your module uses AnyEvent, it works transparently with all	92	your module uses AnyEvent, it works transparently with all event models it
91	event models it supports (including stuff like IO::Async, as long as those	93	supports (including stuff like IO::Async, as long as those use one of the
92	use one of the supported event loops. It is trivial to add new event loops	94	supported event loops. It is easy to add new event loops to AnyEvent, too,
93	to AnyEvent, too, so it is future-proof).	95	so it is future-proof).
94		96
95	In addition to being free of having to use I<the one and only true event	97	In addition to being free of having to use I<the one and only true event
96	model>, AnyEvent also is free of bloat and policy: with POE or similar	98	model>, AnyEvent also is free of bloat and policy: with POE or similar
97	modules, you get an enormous amount of code and strict rules you have to	99	modules, you get an enormous amount of code and strict rules you have to
98	follow. AnyEvent, on the other hand, is lean and up to the point, by only	100	follow. AnyEvent, on the other hand, is lean and to the point, by only
99	offering the functionality that is necessary, in as thin as a wrapper as	101	offering the functionality that is necessary, in as thin as a wrapper as
100	technically possible.	102	technically possible.
101		103
102	Of course, AnyEvent comes with a big (and fully optional!) toolbox	104	Of course, AnyEvent comes with a big (and fully optional!) toolbox
103	of useful functionality, such as an asynchronous DNS resolver, 100%	105	of useful functionality, such as an asynchronous DNS resolver, 100%
…		…
109	useful) and you want to force your users to use the one and only event	111	useful) and you want to force your users to use the one and only event
110	model, you should I<not> use this module.	112	model, you should I<not> use this module.
111		113
112	=head1 DESCRIPTION	114	=head1 DESCRIPTION
113		115
114	L<AnyEvent> provides an identical interface to multiple event loops. This	116	L<AnyEvent> provides a uniform interface to various event loops. This
115	allows module authors to utilise an event loop without forcing module	117	allows module authors to use event loop functionality without forcing
116	users to use the same event loop (as only a single event loop can coexist	118	module users to use a specific event loop implementation (since more
117	peacefully at any one time).	119	than one event loop cannot coexist peacefully).
118		120
119	The interface itself is vaguely similar, but not identical to the L<Event>	121	The interface itself is vaguely similar, but not identical to the L<Event>
120	module.	122	module.
121		123
122	During the first call of any watcher-creation method, the module tries	124	During the first call of any watcher-creation method, the module tries
123	to detect the currently loaded event loop by probing whether one of the	125	to detect the currently loaded event loop by probing whether one of the
124	following modules is already loaded: L<EV>,	126	following modules is already loaded: L<EV>, L<AnyEvent::Loop>,
125	L<Event>, L<Glib>, L<AnyEvent::Impl::Perl>, L<Tk>, L<Event::Lib>, L<Qt>,	127	L<Event>, L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>. The first one
126	L<POE>. The first one found is used. If none are found, the module tries	128	found is used. If none are detected, the module tries to load the first
127	to load these modules (excluding Tk, Event::Lib, Qt and POE as the pure perl	129	four modules in the order given; but note that if L<EV> is not
128	adaptor should always succeed) in the order given. The first one that can	130	available, the pure-perl L<AnyEvent::Loop> should always work, so
129	be successfully loaded will be used. If, after this, still none could be	131	the other two are not normally tried.
130	found, AnyEvent will fall back to a pure-perl event loop, which is not
131	very efficient, but should work everywhere.
132		132
133	Because AnyEvent first checks for modules that are already loaded, loading	133	Because AnyEvent first checks for modules that are already loaded, loading
134	an event model explicitly before first using AnyEvent will likely make	134	an event model explicitly before first using AnyEvent will likely make
135	that model the default. For example:	135	that model the default. For example:
136		136
…		…
138	use AnyEvent;	138	use AnyEvent;
139		139
140	# .. AnyEvent will likely default to Tk	140	# .. AnyEvent will likely default to Tk
141		141
142	The I<likely> means that, if any module loads another event model and	142	The I<likely> means that, if any module loads another event model and
143	starts using it, all bets are off. Maybe you should tell their authors to	143	starts using it, all bets are off - this case should be very rare though,
144	use AnyEvent so their modules work together with others seamlessly...	144	as very few modules hardcode event loops without announcing this very
		145	loudly.
145		146
146	The pure-perl implementation of AnyEvent is called	147	The pure-perl implementation of AnyEvent is called C<AnyEvent::Loop>. Like
147	C<AnyEvent::Impl::Perl>. Like other event modules you can load it	148	other event modules you can load it explicitly and enjoy the high
148	explicitly and enjoy the high availability of that event loop :)	149	availability of that event loop :)
149		150
150	=head1 WATCHERS	151	=head1 WATCHERS
151		152
152	AnyEvent has the central concept of a I<watcher>, which is an object that	153	AnyEvent has the central concept of a I<watcher>, which is an object that
153	stores relevant data for each kind of event you are waiting for, such as	154	stores relevant data for each kind of event you are waiting for, such as
…		…
158	callback when the event occurs (of course, only when the event model	159	callback when the event occurs (of course, only when the event model
159	is in control).	160	is in control).
160		161
161	Note that B<callbacks must not permanently change global variables>	162	Note that B<callbacks must not permanently change global variables>
162	potentially in use by the event loop (such as C<$_> or C<$[>) and that B<<	163	potentially in use by the event loop (such as C<$_> or C<$[>) and that B<<
163	callbacks must not C<die> >>. The former is good programming practise in	164	callbacks must not C<die> >>. The former is good programming practice in
164	Perl and the latter stems from the fact that exception handling differs	165	Perl and the latter stems from the fact that exception handling differs
165	widely between event loops.	166	widely between event loops.
166		167
167	To disable the watcher you have to destroy it (e.g. by setting the	168	To disable a watcher you have to destroy it (e.g. by setting the
168	variable you store it in to C<undef> or otherwise deleting all references	169	variable you store it in to C<undef> or otherwise deleting all references
169	to it).	170	to it).
170		171
171	All watchers are created by calling a method on the C<AnyEvent> class.	172	All watchers are created by calling a method on the C<AnyEvent> class.
172		173
173	Many watchers either are used with "recursion" (repeating timers for	174	Many watchers either are used with "recursion" (repeating timers for
174	example), or need to refer to their watcher object in other ways.	175	example), or need to refer to their watcher object in other ways.
175		176
176	An any way to achieve that is this pattern:	177	One way to achieve that is this pattern:
177		178
178	my $w; $w = AnyEvent->type (arg => value ..., cb => sub {	179	my $w; $w = AnyEvent->type (arg => value ..., cb => sub {
179	# you can use $w here, for example to undef it	180	# you can use $w here, for example to undef it
180	undef $w;	181	undef $w;
181	});	182	});
…		…
213		214
214	The I/O watcher might use the underlying file descriptor or a copy of it.	215	The I/O watcher might use the underlying file descriptor or a copy of it.
215	You must not close a file handle as long as any watcher is active on the	216	You must not close a file handle as long as any watcher is active on the
216	underlying file descriptor.	217	underlying file descriptor.
217		218
218	Some event loops issue spurious readyness notifications, so you should	219	Some event loops issue spurious readiness notifications, so you should
219	always use non-blocking calls when reading/writing from/to your file	220	always use non-blocking calls when reading/writing from/to your file
220	handles.	221	handles.
221		222
222	Example: wait for readability of STDIN, then read a line and disable the	223	Example: wait for readability of STDIN, then read a line and disable the
223	watcher.	224	watcher.
…		…
247		248
248	Although the callback might get passed parameters, their value and	249	Although the callback might get passed parameters, their value and
249	presence is undefined and you cannot rely on them. Portable AnyEvent	250	presence is undefined and you cannot rely on them. Portable AnyEvent
250	callbacks cannot use arguments passed to time watcher callbacks.	251	callbacks cannot use arguments passed to time watcher callbacks.
251		252
252	The callback will normally be invoked once only. If you specify another	253	The callback will normally be invoked only once. If you specify another
253	parameter, C<interval>, as a strictly positive number (> 0), then the	254	parameter, C<interval>, as a strictly positive number (> 0), then the
254	callback will be invoked regularly at that interval (in fractional	255	callback will be invoked regularly at that interval (in fractional
255	seconds) after the first invocation. If C<interval> is specified with a	256	seconds) after the first invocation. If C<interval> is specified with a
256	false value, then it is treated as if it were missing.	257	false value, then it is treated as if it were not specified at all.
257		258
258	The callback will be rescheduled before invoking the callback, but no	259	The callback will be rescheduled before invoking the callback, but no
259	attempt is done to avoid timer drift in most backends, so the interval is	260	attempt is made to avoid timer drift in most backends, so the interval is
260	only approximate.	261	only approximate.
261		262
262	Example: fire an event after 7.7 seconds.	263	Example: fire an event after 7.7 seconds.
263		264
264	my $w = AnyEvent->timer (after => 7.7, cb => sub {	265	my $w = AnyEvent->timer (after => 7.7, cb => sub {
…		…
282		283
283	While most event loops expect timers to specified in a relative way, they	284	While most event loops expect timers to specified in a relative way, they
284	use absolute time internally. This makes a difference when your clock	285	use absolute time internally. This makes a difference when your clock
285	"jumps", for example, when ntp decides to set your clock backwards from	286	"jumps", for example, when ntp decides to set your clock backwards from
286	the wrong date of 2014-01-01 to 2008-01-01, a watcher that is supposed to	287	the wrong date of 2014-01-01 to 2008-01-01, a watcher that is supposed to
287	fire "after" a second might actually take six years to finally fire.	288	fire "after a second" might actually take six years to finally fire.
288		289
289	AnyEvent cannot compensate for this. The only event loop that is conscious	290	AnyEvent cannot compensate for this. The only event loop that is conscious
290	about these issues is L<EV>, which offers both relative (ev_timer, based	291	of these issues is L<EV>, which offers both relative (ev_timer, based
291	on true relative time) and absolute (ev_periodic, based on wallclock time)	292	on true relative time) and absolute (ev_periodic, based on wallclock time)
292	timers.	293	timers.
293		294
294	AnyEvent always prefers relative timers, if available, matching the	295	AnyEvent always prefers relative timers, if available, matching the
295	AnyEvent API.	296	AnyEvent API.
…		…
317	I<In almost all cases (in all cases if you don't care), this is the	318	I<In almost all cases (in all cases if you don't care), this is the
318	function to call when you want to know the current time.>	319	function to call when you want to know the current time.>
319		320
320	This function is also often faster then C<< AnyEvent->time >>, and	321	This function is also often faster then C<< AnyEvent->time >>, and
321	thus the preferred method if you want some timestamp (for example,	322	thus the preferred method if you want some timestamp (for example,
322	L<AnyEvent::Handle> uses this to update it's activity timeouts).	323	L<AnyEvent::Handle> uses this to update its activity timeouts).
323		324
324	The rest of this section is only of relevance if you try to be very exact	325	The rest of this section is only of relevance if you try to be very exact
325	with your timing, you can skip it without bad conscience.	326	with your timing; you can skip it without a bad conscience.
326		327
327	For a practical example of when these times differ, consider L<Event::Lib>	328	For a practical example of when these times differ, consider L<Event::Lib>
328	and L<EV> and the following set-up:	329	and L<EV> and the following set-up:
329		330
330	The event loop is running and has just invoked one of your callback at	331	The event loop is running and has just invoked one of your callbacks at
331	time=500 (assume no other callbacks delay processing). In your callback,	332	time=500 (assume no other callbacks delay processing). In your callback,
332	you wait a second by executing C<sleep 1> (blocking the process for a	333	you wait a second by executing C<sleep 1> (blocking the process for a
333	second) and then (at time=501) you create a relative timer that fires	334	second) and then (at time=501) you create a relative timer that fires
334	after three seconds.	335	after three seconds.
335		336
…		…
355	difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into	356	difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into
356	account.	357	account.
357		358
358	=item AnyEvent->now_update	359	=item AnyEvent->now_update
359		360
360	Some event loops (such as L<EV> or L<AnyEvent::Impl::Perl>) cache	361	Some event loops (such as L<EV> or L<AnyEvent::Loop>) cache the current
361	the current time for each loop iteration (see the discussion of L<<	362	time for each loop iteration (see the discussion of L<< AnyEvent->now >>,
362	AnyEvent->now >>, above).	363	above).
363		364
364	When a callback runs for a long time (or when the process sleeps), then	365	When a callback runs for a long time (or when the process sleeps), then
365	this "current" time will differ substantially from the real time, which	366	this "current" time will differ substantially from the real time, which
366	might affect timers and time-outs.	367	might affect timers and time-outs.
367		368
…		…
414	not restart syscalls (that includes L<Async::Interrupt> and AnyEvent's	415	not restart syscalls (that includes L<Async::Interrupt> and AnyEvent's
415	pure perl implementation).	416	pure perl implementation).
416		417
417	=head3 Safe/Unsafe Signals	418	=head3 Safe/Unsafe Signals
418		419
419	Perl signals can be either "safe" (synchronous to opcode handling) or	420	Perl signals can be either "safe" (synchronous to opcode handling)
420	"unsafe" (asynchronous) - the former might get delayed indefinitely, the	421	or "unsafe" (asynchronous) - the former might delay signal delivery
421	latter might corrupt your memory.	422	indefinitely, the latter might corrupt your memory.
422		423
423	AnyEvent signal handlers are, in addition, synchronous to the event loop,	424	AnyEvent signal handlers are, in addition, synchronous to the event loop,
424	i.e. they will not interrupt your running perl program but will only be	425	i.e. they will not interrupt your running perl program but will only be
425	called as part of the normal event handling (just like timer, I/O etc.	426	called as part of the normal event handling (just like timer, I/O etc.
426	callbacks, too).	427	callbacks, too).
427		428
428	=head3 Signal Races, Delays and Workarounds	429	=head3 Signal Races, Delays and Workarounds
429		430
430	Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support attaching	431	Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support
431	callbacks to signals in a generic way, which is a pity, as you cannot	432	attaching callbacks to signals in a generic way, which is a pity,
432	do race-free signal handling in perl, requiring C libraries for	433	as you cannot do race-free signal handling in perl, requiring
433	this. AnyEvent will try to do it's best, which means in some cases,	434	C libraries for this. AnyEvent will try to do its best, which
434	signals will be delayed. The maximum time a signal might be delayed is	435	means in some cases, signals will be delayed. The maximum time
435	specified in C<$AnyEvent::MAX_SIGNAL_LATENCY> (default: 10 seconds). This	436	a signal might be delayed is 10 seconds by default, but can
436	variable can be changed only before the first signal watcher is created,	437	be overriden via C<$ENV{PERL_ANYEVENT_MAX_SIGNAL_LATENCY}> or
437	and should be left alone otherwise. This variable determines how often	438	C<$AnyEvent::MAX_SIGNAL_LATENCY> - see the L<ENVIRONMENT VARIABLES>
438	AnyEvent polls for signals (in case a wake-up was missed). Higher values	439	section for details.
439	will cause fewer spurious wake-ups, which is better for power and CPU
440	saving.
441		440
442	All these problems can be avoided by installing the optional	441	All these problems can be avoided by installing the optional
443	L<Async::Interrupt> module, which works with most event loops. It will not	442	L<Async::Interrupt> module, which works with most event loops. It will not
444	work with inherently broken event loops such as L<Event> or L<Event::Lib>	443	work with inherently broken event loops such as L<Event> or L<Event::Lib>
445	(and not with L<POE> currently, as POE does it's own workaround with	444	(and not with L<POE> currently). For those, you just have to suffer the
446	one-second latency). For those, you just have to suffer the delays.	445	delays.
447		446
448	=head2 CHILD PROCESS WATCHERS	447	=head2 CHILD PROCESS WATCHERS
449		448
450	$w = AnyEvent->child (pid => <process id>, cb => <callback>);	449	$w = AnyEvent->child (pid => <process id>, cb => <callback>);
451		450
452	You can also watch on a child process exit and catch its exit status.	451	You can also watch for a child process exit and catch its exit status.
453		452
454	The child process is specified by the C<pid> argument (one some backends,	453	The child process is specified by the C<pid> argument (on some backends,
455	using C<0> watches for any child process exit, on others this will	454	using C<0> watches for any child process exit, on others this will
456	croak). The watcher will be triggered only when the child process has	455	croak). The watcher will be triggered only when the child process has
457	finished and an exit status is available, not on any trace events	456	finished and an exit status is available, not on any trace events
458	(stopped/continued).	457	(stopped/continued).
459		458
…		…
481	thing in an AnyEvent program, you I<have> to create at least one	480	thing in an AnyEvent program, you I<have> to create at least one
482	watcher before you C<fork> the child (alternatively, you can call	481	watcher before you C<fork> the child (alternatively, you can call
483	C<AnyEvent::detect>).	482	C<AnyEvent::detect>).
484		483
485	As most event loops do not support waiting for child events, they will be	484	As most event loops do not support waiting for child events, they will be
486	emulated by AnyEvent in most cases, in which the latency and race problems	485	emulated by AnyEvent in most cases, in which case the latency and race
487	mentioned in the description of signal watchers apply.	486	problems mentioned in the description of signal watchers apply.
488		487
489	Example: fork a process and wait for it	488	Example: fork a process and wait for it
490		489
491	my $done = AnyEvent->condvar;	490	my $done = AnyEvent->condvar;
492		491
…		…
506		505
507	=head2 IDLE WATCHERS	506	=head2 IDLE WATCHERS
508		507
509	$w = AnyEvent->idle (cb => <callback>);	508	$w = AnyEvent->idle (cb => <callback>);
510		509
511	Repeatedly invoke the callback after the process becomes idle, until	510	This will repeatedly invoke the callback after the process becomes idle,
512	either the watcher is destroyed or new events have been detected.	511	until either the watcher is destroyed or new events have been detected.
513		512
514	Idle watchers are useful when there is a need to do something, but it	513	Idle watchers are useful when there is a need to do something, but it
515	is not so important (or wise) to do it instantly. The callback will be	514	is not so important (or wise) to do it instantly. The callback will be
516	invoked only when there is "nothing better to do", which is usually	515	invoked only when there is "nothing better to do", which is usually
517	defined as "all outstanding events have been handled and no new events	516	defined as "all outstanding events have been handled and no new events
…		…
556	will actively watch for new events and call your callbacks.	555	will actively watch for new events and call your callbacks.
557		556
558	AnyEvent is slightly different: it expects somebody else to run the event	557	AnyEvent is slightly different: it expects somebody else to run the event
559	loop and will only block when necessary (usually when told by the user).	558	loop and will only block when necessary (usually when told by the user).
560		559
561	The instrument to do that is called a "condition variable", so called	560	The tool to do that is called a "condition variable", so called because
562	because they represent a condition that must become true.	561	they represent a condition that must become true.
563		562
564	Now is probably a good time to look at the examples further below.	563	Now is probably a good time to look at the examples further below.
565		564
566	Condition variables can be created by calling the C<< AnyEvent->condvar	565	Condition variables can be created by calling the C<< AnyEvent->condvar
567	>> method, usually without arguments. The only argument pair allowed is	566	>> method, usually without arguments. The only argument pair allowed is
…		…
572	After creation, the condition variable is "false" until it becomes "true"	571	After creation, the condition variable is "false" until it becomes "true"
573	by calling the C<send> method (or calling the condition variable as if it	572	by calling the C<send> method (or calling the condition variable as if it
574	were a callback, read about the caveats in the description for the C<<	573	were a callback, read about the caveats in the description for the C<<
575	->send >> method).	574	->send >> method).
576		575
577	Condition variables are similar to callbacks, except that you can	576	Since condition variables are the most complex part of the AnyEvent API, here are
578	optionally wait for them. They can also be called merge points - points	577	some different mental models of what they are - pick the ones you can connect to:
579	in time where multiple outstanding events have been processed. And yet	578
580	another way to call them is transactions - each condition variable can be	579	=over 4
581	used to represent a transaction, which finishes at some point and delivers	580
582	a result. And yet some people know them as "futures" - a promise to	581	=item * Condition variables are like callbacks - you can call them (and pass them instead
583	compute/deliver something that you can wait for.	582	of callbacks). Unlike callbacks however, you can also wait for them to be called.
		583
		584	=item * Condition variables are signals - one side can emit or send them,
		585	the other side can wait for them, or install a handler that is called when
		586	the signal fires.
		587
		588	=item * Condition variables are like "Merge Points" - points in your program
		589	where you merge multiple independent results/control flows into one.
		590
		591	=item * Condition variables represent a transaction - functions that start
		592	some kind of transaction can return them, leaving the caller the choice
		593	between waiting in a blocking fashion, or setting a callback.
		594
		595	=item * Condition variables represent future values, or promises to deliver
		596	some result, long before the result is available.
		597
		598	=back
584		599
585	Condition variables are very useful to signal that something has finished,	600	Condition variables are very useful to signal that something has finished,
586	for example, if you write a module that does asynchronous http requests,	601	for example, if you write a module that does asynchronous http requests,
587	then a condition variable would be the ideal candidate to signal the	602	then a condition variable would be the ideal candidate to signal the
588	availability of results. The user can either act when the callback is	603	availability of results. The user can either act when the callback is
…		…
601		616
602	Condition variables are represented by hash refs in perl, and the keys	617	Condition variables are represented by hash refs in perl, and the keys
603	used by AnyEvent itself are all named C<_ae_XXX> to make subclassing	618	used by AnyEvent itself are all named C<_ae_XXX> to make subclassing
604	easy (it is often useful to build your own transaction class on top of	619	easy (it is often useful to build your own transaction class on top of
605	AnyEvent). To subclass, use C<AnyEvent::CondVar> as base class and call	620	AnyEvent). To subclass, use C<AnyEvent::CondVar> as base class and call
606	it's C<new> method in your own C<new> method.	621	its C<new> method in your own C<new> method.
607		622
608	There are two "sides" to a condition variable - the "producer side" which	623	There are two "sides" to a condition variable - the "producer side" which
609	eventually calls C<< -> send >>, and the "consumer side", which waits	624	eventually calls C<< -> send >>, and the "consumer side", which waits
610	for the send to occur.	625	for the send to occur.
611		626
…		…
676	they were a code reference). Calling them directly is the same as calling	691	they were a code reference). Calling them directly is the same as calling
677	C<send>.	692	C<send>.
678		693
679	=item $cv->croak ($error)	694	=item $cv->croak ($error)
680		695
681	Similar to send, but causes all call's to C<< ->recv >> to invoke	696	Similar to send, but causes all calls to C<< ->recv >> to invoke
682	C<Carp::croak> with the given error message/object/scalar.	697	C<Carp::croak> with the given error message/object/scalar.
683		698
684	This can be used to signal any errors to the condition variable	699	This can be used to signal any errors to the condition variable
685	user/consumer. Doing it this way instead of calling C<croak> directly	700	user/consumer. Doing it this way instead of calling C<croak> directly
686	delays the error detetcion, but has the overwhelmign advantage that it	701	delays the error detection, but has the overwhelming advantage that it
687	diagnoses the error at the place where the result is expected, and not	702	diagnoses the error at the place where the result is expected, and not
688	deep in some event clalback without connection to the actual code causing	703	deep in some event callback with no connection to the actual code causing
689	the problem.	704	the problem.
690		705
691	=item $cv->begin ([group callback])	706	=item $cv->begin ([group callback])
692		707
693	=item $cv->end	708	=item $cv->end
…		…
731	one call to C<begin>, so the condvar waits for all calls to C<end> before	746	one call to C<begin>, so the condvar waits for all calls to C<end> before
732	sending.	747	sending.
733		748
734	The ping example mentioned above is slightly more complicated, as the	749	The ping example mentioned above is slightly more complicated, as the
735	there are results to be passwd back, and the number of tasks that are	750	there are results to be passwd back, and the number of tasks that are
736	begung can potentially be zero:	751	begun can potentially be zero:
737		752
738	my $cv = AnyEvent->condvar;	753	my $cv = AnyEvent->condvar;
739		754
740	my %result;	755	my %result;
741	$cv->begin (sub { shift->send (\%result) });	756	$cv->begin (sub { shift->send (\%result) });
…		…
748	};	763	};
749	}	764	}
750		765
751	$cv->end;	766	$cv->end;
752		767
		768	...
		769
		770	my $results = $cv->recv;
		771
753	This code fragment supposedly pings a number of hosts and calls	772	This code fragment supposedly pings a number of hosts and calls
754	C<send> after results for all then have have been gathered - in any	773	C<send> after results for all then have have been gathered - in any
755	order. To achieve this, the code issues a call to C<begin> when it starts	774	order. To achieve this, the code issues a call to C<begin> when it starts
756	each ping request and calls C<end> when it has received some result for	775	each ping request and calls C<end> when it has received some result for
757	it. Since C<begin> and C<end> only maintain a counter, the order in which	776	it. Since C<begin> and C<end> only maintain a counter, the order in which
…		…
762	to be called once the counter reaches C<0>, and second, it ensures that	781	to be called once the counter reaches C<0>, and second, it ensures that
763	C<send> is called even when C<no> hosts are being pinged (the loop	782	C<send> is called even when C<no> hosts are being pinged (the loop
764	doesn't execute once).	783	doesn't execute once).
765		784
766	This is the general pattern when you "fan out" into multiple (but	785	This is the general pattern when you "fan out" into multiple (but
767	potentially none) subrequests: use an outer C<begin>/C<end> pair to set	786	potentially zero) subrequests: use an outer C<begin>/C<end> pair to set
768	the callback and ensure C<end> is called at least once, and then, for each	787	the callback and ensure C<end> is called at least once, and then, for each
769	subrequest you start, call C<begin> and for each subrequest you finish,	788	subrequest you start, call C<begin> and for each subrequest you finish,
770	call C<end>.	789	call C<end>.
771		790
772	=back	791	=back
…		…
779	=over 4	798	=over 4
780		799
781	=item $cv->recv	800	=item $cv->recv
782		801
783	Wait (blocking if necessary) until the C<< ->send >> or C<< ->croak	802	Wait (blocking if necessary) until the C<< ->send >> or C<< ->croak
784	>> methods have been called on c<$cv>, while servicing other watchers	803	>> methods have been called on C<$cv>, while servicing other watchers
785	normally.	804	normally.
786		805
787	You can only wait once on a condition - additional calls are valid but	806	You can only wait once on a condition - additional calls are valid but
788	will return immediately.	807	will return immediately.
789		808
…		…
792		811
793	In list context, all parameters passed to C<send> will be returned,	812	In list context, all parameters passed to C<send> will be returned,
794	in scalar context only the first one will be returned.	813	in scalar context only the first one will be returned.
795		814
796	Note that doing a blocking wait in a callback is not supported by any	815	Note that doing a blocking wait in a callback is not supported by any
797	event loop, that is, recursive invocation of a blocking C<< ->recv	816	event loop, that is, recursive invocation of a blocking C<< ->recv >> is
798	>> is not allowed, and the C<recv> call will C<croak> if such a	817	not allowed and the C<recv> call will C<croak> if such a condition is
799	condition is detected. This condition can be slightly loosened by using	818	detected. This requirement can be dropped by relying on L<Coro::AnyEvent>
800	L<Coro::AnyEvent>, which allows you to do a blocking C<< ->recv >> from	819	, which allows you to do a blocking C<< ->recv >> from any thread
801	any thread that doesn't run the event loop itself.	820	that doesn't run the event loop itself. L<Coro::AnyEvent> is loaded
		821	automatically when L<Coro> is used with L<AnyEvent>, so code does not need
		822	to do anything special to take advantage of that: any code that would
		823	normally block your program because it calls C<recv>, be executed in an
		824	C<async> thread instead without blocking other threads.
802		825
803	Not all event models support a blocking wait - some die in that case	826	Not all event models support a blocking wait - some die in that case
804	(programs might want to do that to stay interactive), so I<if you are	827	(programs might want to do that to stay interactive), so I<if you are
805	using this from a module, never require a blocking wait>. Instead, let the	828	using this from a module, never require a blocking wait>. Instead, let the
806	caller decide whether the call will block or not (for example, by coupling	829	caller decide whether the call will block or not (for example, by coupling
807	condition variables with some kind of request results and supporting	830	condition variables with some kind of request results and supporting
808	callbacks so the caller knows that getting the result will not block,	831	callbacks so the caller knows that getting the result will not block,
809	while still supporting blocking waits if the caller so desires).	832	while still supporting blocking waits if the caller so desires).
810		833
811	You can ensure that C<< -recv >> never blocks by setting a callback and	834	You can ensure that C<< ->recv >> never blocks by setting a callback and
812	only calling C<< ->recv >> from within that callback (or at a later	835	only calling C<< ->recv >> from within that callback (or at a later
813	time). This will work even when the event loop does not support blocking	836	time). This will work even when the event loop does not support blocking
814	waits otherwise.	837	waits otherwise.
815		838
816	=item $bool = $cv->ready	839	=item $bool = $cv->ready
…		…
821	=item $cb = $cv->cb ($cb->($cv))	844	=item $cb = $cv->cb ($cb->($cv))
822		845
823	This is a mutator function that returns the callback set and optionally	846	This is a mutator function that returns the callback set and optionally
824	replaces it before doing so.	847	replaces it before doing so.
825		848
826	The callback will be called when the condition becomes (or already was)	849	The callback will be called when the condition becomes "true", i.e. when
827	"true", i.e. when C<send> or C<croak> are called (or were called), with	850	C<send> or C<croak> are called, with the only argument being the
828	the only argument being the condition variable itself. Calling C<recv>	851	condition variable itself. If the condition is already true, the
		852	callback is called immediately when it is set. Calling C<recv> inside
829	inside the callback or at any later time is guaranteed not to block.	853	the callback or at any later time is guaranteed not to block.
830		854
831	=back	855	=back
832		856
833	=head1 SUPPORTED EVENT LOOPS/BACKENDS	857	=head1 SUPPORTED EVENT LOOPS/BACKENDS
834		858
…		…
842	use. If EV is not installed, then AnyEvent will fall back to its own	866	use. If EV is not installed, then AnyEvent will fall back to its own
843	pure-perl implementation, which is available everywhere as it comes with	867	pure-perl implementation, which is available everywhere as it comes with
844	AnyEvent itself.	868	AnyEvent itself.
845		869
846	AnyEvent::Impl::EV based on EV (interface to libev, best choice).	870	AnyEvent::Impl::EV based on EV (interface to libev, best choice).
847	AnyEvent::Impl::Perl pure-perl implementation, fast and portable.	871	AnyEvent::Impl::Perl pure-perl AnyEvent::Loop, fast and portable.
848		872
849	=item Backends that are transparently being picked up when they are used.	873	=item Backends that are transparently being picked up when they are used.
850		874
851	These will be used when they are currently loaded when the first watcher	875	These will be used if they are already loaded when the first watcher
852	is created, in which case it is assumed that the application is using	876	is created, in which case it is assumed that the application is using
853	them. This means that AnyEvent will automatically pick the right backend	877	them. This means that AnyEvent will automatically pick the right backend
854	when the main program loads an event module before anything starts to	878	when the main program loads an event module before anything starts to
855	create watchers. Nothing special needs to be done by the main program.	879	create watchers. Nothing special needs to be done by the main program.
856		880
…		…
858	AnyEvent::Impl::Glib based on Glib, slow but very stable.	882	AnyEvent::Impl::Glib based on Glib, slow but very stable.
859	AnyEvent::Impl::Tk based on Tk, very broken.	883	AnyEvent::Impl::Tk based on Tk, very broken.
860	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.	884	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
861	AnyEvent::Impl::POE based on POE, very slow, some limitations.	885	AnyEvent::Impl::POE based on POE, very slow, some limitations.
862	AnyEvent::Impl::Irssi used when running within irssi.	886	AnyEvent::Impl::Irssi used when running within irssi.
		887	AnyEvent::Impl::IOAsync based on IO::Async.
		888	AnyEvent::Impl::Cocoa based on Cocoa::EventLoop.
		889	AnyEvent::Impl::FLTK based on FLTK (fltk 2 binding).
863		890
864	=item Backends with special needs.	891	=item Backends with special needs.
865		892
866	Qt requires the Qt::Application to be instantiated first, but will	893	Qt requires the Qt::Application to be instantiated first, but will
867	otherwise be picked up automatically. As long as the main program	894	otherwise be picked up automatically. As long as the main program
868	instantiates the application before any AnyEvent watchers are created,	895	instantiates the application before any AnyEvent watchers are created,
869	everything should just work.	896	everything should just work.
870		897
871	AnyEvent::Impl::Qt based on Qt.	898	AnyEvent::Impl::Qt based on Qt.
872		899
873	Support for IO::Async can only be partial, as it is too broken and
874	architecturally limited to even support the AnyEvent API. It also
875	is the only event loop that needs the loop to be set explicitly, so
876	it can only be used by a main program knowing about AnyEvent. See
877	L<AnyEvent::Impl::Async> for the gory details.
878
879	AnyEvent::Impl::IOAsync based on IO::Async, cannot be autoprobed.
880
881	=item Event loops that are indirectly supported via other backends.	900	=item Event loops that are indirectly supported via other backends.
882		901
883	Some event loops can be supported via other modules:	902	Some event loops can be supported via other modules:
884		903
885	There is no direct support for WxWidgets (L<Wx>) or L<Prima>.	904	There is no direct support for WxWidgets (L<Wx>) or L<Prima>.
…		…
910	Contains C<undef> until the first watcher is being created, before the	929	Contains C<undef> until the first watcher is being created, before the
911	backend has been autodetected.	930	backend has been autodetected.
912		931
913	Afterwards it contains the event model that is being used, which is the	932	Afterwards it contains the event model that is being used, which is the
914	name of the Perl class implementing the model. This class is usually one	933	name of the Perl class implementing the model. This class is usually one
915	of the C<AnyEvent::Impl:xxx> modules, but can be any other class in the	934	of the C<AnyEvent::Impl::xxx> modules, but can be any other class in the
916	case AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode> it	935	case AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode> it
917	will be C<urxvt::anyevent>).	936	will be C<urxvt::anyevent>).
918		937
919	=item AnyEvent::detect	938	=item AnyEvent::detect
920		939
921	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model	940	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model
922	if necessary. You should only call this function right before you would	941	if necessary. You should only call this function right before you would
923	have created an AnyEvent watcher anyway, that is, as late as possible at	942	have created an AnyEvent watcher anyway, that is, as late as possible at
924	runtime, and not e.g. while initialising of your module.	943	runtime, and not e.g. during initialisation of your module.
		944
		945	The effect of calling this function is as if a watcher had been created
		946	(specifically, actions that happen "when the first watcher is created"
		947	happen when calling detetc as well).
925		948
926	If you need to do some initialisation before AnyEvent watchers are	949	If you need to do some initialisation before AnyEvent watchers are
927	created, use C<post_detect>.	950	created, use C<post_detect>.
928		951
929	=item $guard = AnyEvent::post_detect { BLOCK }	952	=item $guard = AnyEvent::post_detect { BLOCK }
930		953
931	Arranges for the code block to be executed as soon as the event model is	954	Arranges for the code block to be executed as soon as the event model is
932	autodetected (or immediately if this has already happened).	955	autodetected (or immediately if that has already happened).
933		956
934	The block will be executed I<after> the actual backend has been detected	957	The block will be executed I<after> the actual backend has been detected
935	(C<$AnyEvent::MODEL> is set), but I<before> any watchers have been	958	(C<$AnyEvent::MODEL> is set), but I<before> any watchers have been
936	created, so it is possible to e.g. patch C<@AnyEvent::ISA> or do	959	created, so it is possible to e.g. patch C<@AnyEvent::ISA> or do
937	other initialisations - see the sources of L<AnyEvent::Strict> or	960	other initialisations - see the sources of L<AnyEvent::Strict> or
…		…
946	that automatically removes the callback again when it is destroyed (or	969	that automatically removes the callback again when it is destroyed (or
947	C<undef> when the hook was immediately executed). See L<AnyEvent::AIO> for	970	C<undef> when the hook was immediately executed). See L<AnyEvent::AIO> for
948	a case where this is useful.	971	a case where this is useful.
949		972
950	Example: Create a watcher for the IO::AIO module and store it in	973	Example: Create a watcher for the IO::AIO module and store it in
951	C<$WATCHER>. Only do so after the event loop is initialised, though.	974	C<$WATCHER>, but do so only do so after the event loop is initialised.
952		975
953	our WATCHER;	976	our WATCHER;
954		977
955	my $guard = AnyEvent::post_detect {	978	my $guard = AnyEvent::post_detect {
956	$WATCHER = AnyEvent->io (fh => IO::AIO::poll_fileno, poll => 'r', cb => \&IO::AIO::poll_cb);	979	$WATCHER = AnyEvent->io (fh => IO::AIO::poll_fileno, poll => 'r', cb => \&IO::AIO::poll_cb);
…		…
964	$WATCHER ||= $guard;	987	$WATCHER ||= $guard;
965		988
966	=item @AnyEvent::post_detect	989	=item @AnyEvent::post_detect
967		990
968	If there are any code references in this array (you can C<push> to it	991	If there are any code references in this array (you can C<push> to it
969	before or after loading AnyEvent), then they will called directly after	992	before or after loading AnyEvent), then they will be called directly
970	the event loop has been chosen.	993	after the event loop has been chosen.
971		994
972	You should check C<$AnyEvent::MODEL> before adding to this array, though:	995	You should check C<$AnyEvent::MODEL> before adding to this array, though:
973	if it is defined then the event loop has already been detected, and the	996	if it is defined then the event loop has already been detected, and the
974	array will be ignored.	997	array will be ignored.
975		998
…		…
992	# AnyEvent not yet initialised, so make sure to load Coro::AnyEvent	1015	# AnyEvent not yet initialised, so make sure to load Coro::AnyEvent
993	# as soon as it is	1016	# as soon as it is
994	push @AnyEvent::post_detect, sub { require Coro::AnyEvent };	1017	push @AnyEvent::post_detect, sub { require Coro::AnyEvent };
995	}	1018	}
996		1019
		1020	=item AnyEvent::postpone { BLOCK }
		1021
		1022	Arranges for the block to be executed as soon as possible, but not before
		1023	the call itself returns. In practise, the block will be executed just
		1024	before the event loop polls for new events, or shortly afterwards.
		1025
		1026	This function never returns anything (to make the C<return postpone { ...
		1027	}> idiom more useful.
		1028
		1029	To understand the usefulness of this function, consider a function that
		1030	asynchronously does something for you and returns some transaction
		1031	object or guard to let you cancel the operation. For example,
		1032	C<AnyEvent::Socket::tcp_connect>:
		1033
		1034	# start a conenction attempt unless one is active
		1035	$self->{connect_guard} ||= AnyEvent::Socket::tcp_connect "www.example.net", 80, sub {
		1036	delete $self->{connect_guard};
		1037	...
		1038	};
		1039
		1040	Imagine that this function could instantly call the callback, for
		1041	example, because it detects an obvious error such as a negative port
		1042	number. Invoking the callback before the function returns causes problems
		1043	however: the callback will be called and will try to delete the guard
		1044	object. But since the function hasn't returned yet, there is nothing to
		1045	delete. When the function eventually returns it will assign the guard
		1046	object to C<< $self->{connect_guard} >>, where it will likely never be
		1047	deleted, so the program thinks it is still trying to connect.
		1048
		1049	This is where C<AnyEvent::postpone> should be used. Instead of calling the
		1050	callback directly on error:
		1051
		1052	$cb->(undef), return # signal error to callback, BAD!
		1053	if $some_error_condition;
		1054
		1055	It should use C<postpone>:
		1056
		1057	AnyEvent::postpone { $cb->(undef) }, return # signal error to callback, later
		1058	if $some_error_condition;
		1059
		1060	=item AnyEvent::log $level, $msg[, @args]
		1061
		1062	Log the given C<$msg> at the given C<$level>.
		1063
		1064	If L<AnyEvent::Log> is not loaded then this function makes a simple test
		1065	to see whether the message will be logged. If the test succeeds it will
		1066	load AnyEvent::Log and call C<AnyEvent::Log::log> - consequently, look at
		1067	the L<AnyEvent::Log> documentation for details.
		1068
		1069	If the test fails it will simply return. Right now this happens when a
		1070	numerical loglevel is used and it is larger than the level specified via
		1071	C<$ENV{PERL_ANYEVENT_VERBOSE}>.
		1072
		1073	If you want to sprinkle loads of logging calls around your code, consider
		1074	creating a logger callback with the C<AnyEvent::Log::logger> function,
		1075	which can reduce typing, codesize and can reduce the logging overhead
		1076	enourmously.
		1077
997	=back	1078	=back
998		1079
999	=head1 WHAT TO DO IN A MODULE	1080	=head1 WHAT TO DO IN A MODULE
1000		1081
1001	As a module author, you should C<use AnyEvent> and call AnyEvent methods	1082	As a module author, you should C<use AnyEvent> and call AnyEvent methods
…		…
1011	because it will stall the whole program, and the whole point of using	1092	because it will stall the whole program, and the whole point of using
1012	events is to stay interactive.	1093	events is to stay interactive.
1013		1094
1014	It is fine, however, to call C<< ->recv >> when the user of your module	1095	It is fine, however, to call C<< ->recv >> when the user of your module
1015	requests it (i.e. if you create a http request object ad have a method	1096	requests it (i.e. if you create a http request object ad have a method
1016	called C<results> that returns the results, it should call C<< ->recv >>	1097	called C<results> that returns the results, it may call C<< ->recv >>
1017	freely, as the user of your module knows what she is doing. always).	1098	freely, as the user of your module knows what she is doing. Always).
1018		1099
1019	=head1 WHAT TO DO IN THE MAIN PROGRAM	1100	=head1 WHAT TO DO IN THE MAIN PROGRAM
1020		1101
1021	There will always be a single main program - the only place that should	1102	There will always be a single main program - the only place that should
1022	dictate which event model to use.	1103	dictate which event model to use.
1023		1104
1024	If it doesn't care, it can just "use AnyEvent" and use it itself, or not	1105	If the program is not event-based, it need not do anything special, even
1025	do anything special (it does not need to be event-based) and let AnyEvent	1106	when it depends on a module that uses an AnyEvent. If the program itself
1026	decide which implementation to chose if some module relies on it.	1107	uses AnyEvent, but does not care which event loop is used, all it needs
		1108	to do is C<use AnyEvent>. In either case, AnyEvent will choose the best
		1109	available loop implementation.
1027		1110
1028	If the main program relies on a specific event model - for example, in	1111	If the main program relies on a specific event model - for example, in
1029	Gtk2 programs you have to rely on the Glib module - you should load the	1112	Gtk2 programs you have to rely on the Glib module - you should load the
1030	event module before loading AnyEvent or any module that uses it: generally	1113	event module before loading AnyEvent or any module that uses it: generally
1031	speaking, you should load it as early as possible. The reason is that	1114	speaking, you should load it as early as possible. The reason is that
1032	modules might create watchers when they are loaded, and AnyEvent will	1115	modules might create watchers when they are loaded, and AnyEvent will
1033	decide on the event model to use as soon as it creates watchers, and it	1116	decide on the event model to use as soon as it creates watchers, and it
1034	might chose the wrong one unless you load the correct one yourself.	1117	might choose the wrong one unless you load the correct one yourself.
1035		1118
1036	You can chose to use a pure-perl implementation by loading the	1119	You can chose to use a pure-perl implementation by loading the
1037	C<AnyEvent::Impl::Perl> module, which gives you similar behaviour	1120	C<AnyEvent::Loop> module, which gives you similar behaviour
1038	everywhere, but letting AnyEvent chose the model is generally better.	1121	everywhere, but letting AnyEvent chose the model is generally better.
1039		1122
1040	=head2 MAINLOOP EMULATION	1123	=head2 MAINLOOP EMULATION
1041		1124
1042	Sometimes (often for short test scripts, or even standalone programs who	1125	Sometimes (often for short test scripts, or even standalone programs who
…		…
1055		1138
1056		1139
1057	=head1 OTHER MODULES	1140	=head1 OTHER MODULES
1058		1141
1059	The following is a non-exhaustive list of additional modules that use	1142	The following is a non-exhaustive list of additional modules that use
1060	AnyEvent as a client and can therefore be mixed easily with other AnyEvent	1143	AnyEvent as a client and can therefore be mixed easily with other
1061	modules and other event loops in the same program. Some of the modules	1144	AnyEvent modules and other event loops in the same program. Some of the
1062	come with AnyEvent, most are available via CPAN.	1145	modules come as part of AnyEvent, the others are available via CPAN (see
		1146	L<http://search.cpan.org/search?m=module&q=anyevent%3A%3A*> for
		1147	a longer non-exhaustive list), and the list is heavily biased towards
		1148	modules of the AnyEvent author himself :)
1063		1149
1064	=over 4	1150	=over 4
1065		1151
1066	=item L<AnyEvent::Util>	1152	=item L<AnyEvent::Util>
1067		1153
1068	Contains various utility functions that replace often-used but blocking	1154	Contains various utility functions that replace often-used blocking
1069	functions such as C<inet_aton> by event-/callback-based versions.	1155	functions such as C<inet_aton> with event/callback-based versions.
1070		1156
1071	=item L<AnyEvent::Socket>	1157	=item L<AnyEvent::Socket>
1072		1158
1073	Provides various utility functions for (internet protocol) sockets,	1159	Provides various utility functions for (internet protocol) sockets,
1074	addresses and name resolution. Also functions to create non-blocking tcp	1160	addresses and name resolution. Also functions to create non-blocking tcp
…		…
1076		1162
1077	=item L<AnyEvent::Handle>	1163	=item L<AnyEvent::Handle>
1078		1164
1079	Provide read and write buffers, manages watchers for reads and writes,	1165	Provide read and write buffers, manages watchers for reads and writes,
1080	supports raw and formatted I/O, I/O queued and fully transparent and	1166	supports raw and formatted I/O, I/O queued and fully transparent and
1081	non-blocking SSL/TLS (via L<AnyEvent::TLS>.	1167	non-blocking SSL/TLS (via L<AnyEvent::TLS>).
1082		1168
1083	=item L<AnyEvent::DNS>	1169	=item L<AnyEvent::DNS>
1084		1170
1085	Provides rich asynchronous DNS resolver capabilities.	1171	Provides rich asynchronous DNS resolver capabilities.
1086		1172
		1173	=item L<AnyEvent::HTTP>, L<AnyEvent::IRC>, L<AnyEvent::XMPP>, L<AnyEvent::GPSD>, L<AnyEvent::IGS>, L<AnyEvent::FCP>
		1174
		1175	Implement event-based interfaces to the protocols of the same name (for
		1176	the curious, IGS is the International Go Server and FCP is the Freenet
		1177	Client Protocol).
		1178
1087	=item L<AnyEvent::HTTP>	1179	=item L<AnyEvent::AIO>
1088		1180
1089	A simple-to-use HTTP library that is capable of making a lot of concurrent	1181	Truly asynchronous (as opposed to non-blocking) I/O, should be in the
1090	HTTP requests.	1182	toolbox of every event programmer. AnyEvent::AIO transparently fuses
		1183	L<IO::AIO> and AnyEvent together, giving AnyEvent access to event-based
		1184	file I/O, and much more.
		1185
		1186	=item L<AnyEvent::Filesys::Notify>
		1187
		1188	AnyEvent is good for non-blocking stuff, but it can't detect file or
		1189	path changes (e.g. "watch this directory for new files", "watch this
		1190	file for changes"). The L<AnyEvent::Filesys::Notify> module promises to
		1191	do just that in a portbale fashion, supporting inotify on GNU/Linux and
		1192	some weird, without doubt broken, stuff on OS X to monitor files. It can
		1193	fall back to blocking scans at regular intervals transparently on other
		1194	platforms, so it's about as portable as it gets.
		1195
		1196	(I haven't used it myself, but I haven't heard anybody complaining about
		1197	it yet).
		1198
		1199	=item L<AnyEvent::DBI>
		1200
		1201	Executes L<DBI> requests asynchronously in a proxy process for you,
		1202	notifying you in an event-based way when the operation is finished.
1091		1203
1092	=item L<AnyEvent::HTTPD>	1204	=item L<AnyEvent::HTTPD>
1093		1205
1094	Provides a simple web application server framework.	1206	A simple embedded webserver.
1095		1207
1096	=item L<AnyEvent::FastPing>	1208	=item L<AnyEvent::FastPing>
1097		1209
1098	The fastest ping in the west.	1210	The fastest ping in the west.
1099		1211
1100	=item L<AnyEvent::DBI>
1101
1102	Executes L<DBI> requests asynchronously in a proxy process.
1103
1104	=item L<AnyEvent::AIO>
1105
1106	Truly asynchronous I/O, should be in the toolbox of every event
1107	programmer. AnyEvent::AIO transparently fuses L<IO::AIO> and AnyEvent
1108	together.
1109
1110	=item L<AnyEvent::BDB>
1111
1112	Truly asynchronous Berkeley DB access. AnyEvent::BDB transparently fuses
1113	L<BDB> and AnyEvent together.
1114
1115	=item L<AnyEvent::GPSD>
1116
1117	A non-blocking interface to gpsd, a daemon delivering GPS information.
1118
1119	=item L<AnyEvent::IRC>
1120
1121	AnyEvent based IRC client module family (replacing the older Net::IRC3).
1122
1123	=item L<AnyEvent::XMPP>
1124
1125	AnyEvent based XMPP (Jabber protocol) module family (replacing the older
1126	Net::XMPP2>.
1127
1128	=item L<AnyEvent::IGS>
1129
1130	A non-blocking interface to the Internet Go Server protocol (used by
1131	L<App::IGS>).
1132
1133	=item L<Net::FCP>
1134
1135	AnyEvent-based implementation of the Freenet Client Protocol, birthplace
1136	of AnyEvent.
1137
1138	=item L<Event::ExecFlow>
1139
1140	High level API for event-based execution flow control.
1141
1142	=item L<Coro>	1212	=item L<Coro>
1143		1213
1144	Has special support for AnyEvent via L<Coro::AnyEvent>.	1214	Has special support for AnyEvent via L<Coro::AnyEvent>, which allows you
		1215	to simply invert the flow control - don't call us, we will call you:
		1216
		1217	async {
		1218	Coro::AnyEvent::sleep 5; # creates a 5s timer and waits for it
		1219	print "5 seconds later!\n";
		1220
		1221	Coro::AnyEvent::readable *STDIN; # uses an I/O watcher
		1222	my $line = <STDIN>; # works for ttys
		1223
		1224	AnyEvent::HTTP::http_get "url", Coro::rouse_cb;
		1225	my ($body, $hdr) = Coro::rouse_wait;
		1226	};
1145		1227
1146	=back	1228	=back
1147		1229
1148	=cut	1230	=cut
1149		1231
1150	package AnyEvent;	1232	package AnyEvent;
1151		1233
1152	# basically a tuned-down version of common::sense	1234	# basically a tuned-down version of common::sense
1153	sub common_sense {	1235	sub common_sense {
1154	# from common:.sense 1.0	1236	# from common:.sense 3.5
		1237	local $^W;
1155	${^WARNING_BITS} = "\xfc\x3f\x33\x00\x0f\xf3\xcf\xc0\xf3\xfc\x33\x00";	1238	${^WARNING_BITS} ^= ${^WARNING_BITS} ^ "\x3c\x3f\x33\x00\x0f\xf0\x0f\xc0\xf0\xfc\x33\x00";
1156	# use strict vars subs - NO UTF-8, as Util.pm doesn't like this atm. (uts46data.pl)	1239	# use strict vars subs - NO UTF-8, as Util.pm doesn't like this atm. (uts46data.pl)
1157	$^H |= 0x00000600;	1240	$^H |= 0x00000600;
1158	}	1241	}
1159		1242
1160	BEGIN { AnyEvent::common_sense }	1243	BEGIN { AnyEvent::common_sense }
1161		1244
1162	use Carp ();	1245	use Carp ();
1163		1246
1164	our $VERSION = '5.261';	1247	our $VERSION = '7.04';
1165	our $MODEL;	1248	our $MODEL;
1166
1167	our $AUTOLOAD;
1168	our @ISA;	1249	our @ISA;
1169
1170	our @REGISTRY;	1250	our @REGISTRY;
1171
1172	our $VERBOSE;	1251	our $VERBOSE;
		1252	our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred
		1253	our $MAX_SIGNAL_LATENCY = $ENV{PERL_ANYEVENT_MAX_SIGNAL_LATENCY} || 10; # executes after the BEGIN block below (tainting!)
1173		1254
1174	BEGIN {	1255	BEGIN {
1175	require "AnyEvent/constants.pl";	1256	require "AnyEvent/constants.pl";
1176		1257
1177	eval "sub TAINT (){" . (${^TAINT}*1) . "}";	1258	eval "sub TAINT (){" . (${^TAINT}*1) . "}";
1178		1259
1179	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}	1260	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}
1180	if ${^TAINT};	1261	if ${^TAINT};
1181		1262
1182	$VERBOSE = $ENV{PERL_ANYEVENT_VERBOSE}*1;	1263	$ENV{"PERL_ANYEVENT_$_"} = $ENV{"AE_$_"}
		1264	for grep s/^AE_// && !exists $ENV{"PERL_ANYEVENT_$_"}, keys %ENV;
1183		1265
1184	}	1266	@ENV{grep /^PERL_ANYEVENT_/, keys %ENV} = ()
		1267	if ${^TAINT};
1185		1268
1186	our $MAX_SIGNAL_LATENCY = 10;	1269	# $ENV{PERL_ANYEVENT_xxx} now valid
1187		1270
1188	our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred	1271	$VERBOSE = length $ENV{PERL_ANYEVENT_VERBOSE} ? $ENV{PERL_ANYEVENT_VERBOSE}*1 : 4;
1189		1272
1190	{
1191	my $idx;	1273	my $idx;
1192	$PROTOCOL{$_} = ++$idx	1274	$PROTOCOL{$_} = ++$idx
1193	for reverse split /\s*,\s*/,	1275	for reverse split /\s*,\s*/,
1194	$ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";	1276	$ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";
1195	}	1277	}
1196		1278
		1279	our @post_detect;
		1280
		1281	sub post_detect(&) {
		1282	my ($cb) = @_;
		1283
		1284	push @post_detect, $cb;
		1285
		1286	defined wantarray
		1287	? bless \$cb, "AnyEvent::Util::postdetect"
		1288	: ()
		1289	}
		1290
		1291	sub AnyEvent::Util::postdetect::DESTROY {
		1292	@post_detect = grep $_ != ${$_[0]}, @post_detect;
		1293	}
		1294
		1295	our $POSTPONE_W;
		1296	our @POSTPONE;
		1297
		1298	sub _postpone_exec {
		1299	undef $POSTPONE_W;
		1300
		1301	&{ shift @POSTPONE }
		1302	while @POSTPONE;
		1303	}
		1304
		1305	sub postpone(&) {
		1306	push @POSTPONE, shift;
		1307
		1308	$POSTPONE_W ||= AE::timer (0, 0, \&_postpone_exec);
		1309
		1310	()
		1311	}
		1312
		1313	sub log($$;@) {
		1314	# only load the big bloated module when we actually are about to log something
		1315	if ($_[0] <= ($VERBOSE || 1)) { # also catches non-numeric levels(!) and fatal
		1316	local ($!, $@);
		1317	require AnyEvent::Log; # among other things, sets $VERBOSE to 9
		1318	# AnyEvent::Log overwrites this function
		1319	goto &log;
		1320	}
		1321
		1322	0 # not logged
		1323	}
		1324
		1325	sub _logger($;$) {
		1326	my ($level, $renabled) = @_;
		1327
		1328	$$renabled = $level <= $VERBOSE;
		1329
		1330	my $logger = [(caller)[0], $level, $renabled];
		1331
		1332	$AnyEvent::Log::LOGGER{$logger+0} = $logger;
		1333
		1334	# return unless defined wantarray;
		1335	#
		1336	# require AnyEvent::Util;
		1337	# my $guard = AnyEvent::Util::guard (sub {
		1338	# # "clean up"
		1339	# delete $LOGGER{$logger+0};
		1340	# });
		1341	#
		1342	# sub {
		1343	# return 0 unless $$renabled;
		1344	#
		1345	# $guard if 0; # keep guard alive, but don't cause runtime overhead
		1346	# require AnyEvent::Log unless $AnyEvent::Log::VERSION;
		1347	# package AnyEvent::Log;
		1348	# _log ($logger->[0], $level, @_) # logger->[0] has been converted at load time
		1349	# }
		1350	}
		1351
		1352	if (length $ENV{PERL_ANYEVENT_LOG}) {
		1353	require AnyEvent::Log; # AnyEvent::Log does the thing for us
		1354	}
		1355
1197	my @models = (	1356	our @models = (
1198	[EV:: => AnyEvent::Impl::EV:: , 1],	1357	[EV:: => AnyEvent::Impl::EV::],
1199	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl:: , 1],	1358	[AnyEvent::Loop:: => AnyEvent::Impl::Perl::],
1200	# everything below here will not (normally) be autoprobed	1359	# everything below here will not (normally) be autoprobed
1201	# as the pureperl backend should work everywhere	1360	# as the pure perl backend should work everywhere
1202	# and is usually faster	1361	# and is usually faster
		1362	[Irssi:: => AnyEvent::Impl::Irssi::], # Irssi has a bogus "Event" package, so msut be near the top
1203	[Event:: => AnyEvent::Impl::Event::, 1],	1363	[Event:: => AnyEvent::Impl::Event::], # slow, stable
1204	[Glib:: => AnyEvent::Impl::Glib:: , 1], # becomes extremely slow with many watchers	1364	[Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers
		1365	# everything below here should not be autoloaded
1205	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy	1366	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
1206	[Irssi:: => AnyEvent::Impl::Irssi::], # Irssi has a bogus "Event" package
1207	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles	1367	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
1208	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program	1368	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program
1209	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza	1369	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
1210	[Wx:: => AnyEvent::Impl::POE::],	1370	[Wx:: => AnyEvent::Impl::POE::],
1211	[Prima:: => AnyEvent::Impl::POE::],	1371	[Prima:: => AnyEvent::Impl::POE::],
1212	# IO::Async is just too broken - we would need workarounds for its	1372	[IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # a bitch to autodetect
1213	# byzantine signal and broken child handling, among others.	1373	[Cocoa::EventLoop:: => AnyEvent::Impl::Cocoa::],
1214	# IO::Async is rather hard to detect, as it doesn't have any	1374	[FLTK:: => AnyEvent::Impl::FLTK::],
1215	# obvious default class.
1216	[IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program
1217	[IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program
1218	[IO::Async::Notifier:: => AnyEvent::Impl::IOAsync::], # requires special main program
1219	[AnyEvent::Impl::IOAsync:: => AnyEvent::Impl::IOAsync::], # requires special main program
1220	);	1375	);
1221		1376
1222	our %method = map +($_ => 1),	1377	our @isa_hook;
		1378
		1379	sub _isa_set {
		1380	my @pkg = ("AnyEvent", (map $_->[0], grep defined, @isa_hook), $MODEL);
		1381
		1382	@{"$pkg[$_-1]::ISA"} = $pkg[$_]
		1383	for 1 .. $#pkg;
		1384
		1385	grep $_ && $_->[1], @isa_hook
		1386	and AE::_reset ();
		1387	}
		1388
		1389	# used for hooking AnyEvent::Strict and AnyEvent::Debug::Wrap into the class hierarchy
		1390	sub _isa_hook($$;$) {
		1391	my ($i, $pkg, $reset_ae) = @_;
		1392
		1393	$isa_hook[$i] = $pkg ? [$pkg, $reset_ae] : undef;
		1394
		1395	_isa_set;
		1396	}
		1397
		1398	# all autoloaded methods reserve the complete glob, not just the method slot.
		1399	# due to bugs in perls method cache implementation.
1223	qw(io timer time now now_update signal child idle condvar one_event DESTROY);	1400	our @methods = qw(io timer time now now_update signal child idle condvar);
1224
1225	our @post_detect;
1226
1227	sub post_detect(&) {
1228	my ($cb) = @_;
1229
1230	push @post_detect, $cb;
1231
1232	defined wantarray
1233	? bless \$cb, "AnyEvent::Util::postdetect"
1234	: ()
1235	}
1236
1237	sub AnyEvent::Util::postdetect::DESTROY {
1238	@post_detect = grep $_ != ${$_[0]}, @post_detect;
1239	}
1240		1401
1241	sub detect() {	1402	sub detect() {
		1403	return $MODEL if $MODEL; # some programs keep references to detect
		1404
		1405	# IO::Async::Loop::AnyEvent is extremely evil, refuse to work with it
		1406	# the author knows about the problems and what it does to AnyEvent as a whole
		1407	# (and the ability of others to use AnyEvent), but simply wants to abuse AnyEvent
		1408	# anyway.
		1409	AnyEvent::log fatal => "IO::Async::Loop::AnyEvent detected - that module is broken by\n"
		1410	. "design, abuses internals and breaks AnyEvent - will not continue."
		1411	if exists $INC{"IO/Async/Loop/AnyEvent.pm"};
		1412
		1413	local $!; # for good measure
		1414	local $SIG{__DIE__}; # we use eval
		1415
1242	# free some memory	1416	# free some memory
1243	*detect = sub () { $MODEL };	1417	*detect = sub () { $MODEL };
		1418	# undef &func doesn't correctly update the method cache. grmbl.
		1419	# so we delete the whole glob. grmbl.
		1420	# otoh, perl doesn't let me undef an active usb, but it lets me free
		1421	# a glob with an active sub. hrm. i hope it works, but perl is
		1422	# usually buggy in this department. sigh.
		1423	delete @{"AnyEvent::"}{@methods};
		1424	undef @methods;
1244		1425
1245	local $!; # for good measure
1246	local $SIG{__DIE__};
1247
1248	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {	1426	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z0-9:]+)$/) {
1249	my $model = "AnyEvent::Impl::$1";	1427	my $model = $1;
		1428	$model = "AnyEvent::Impl::$model" unless $model =~ s/::$//;
1250	if (eval "require $model") {	1429	if (eval "require $model") {
		1430	AnyEvent::log 7 => "Loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.";
1251	$MODEL = $model;	1431	$MODEL = $model;
1252	warn "AnyEvent: loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.\n" if $VERBOSE >= 2;
1253	} else {	1432	} else {
1254	warn "AnyEvent: unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@" if $VERBOSE;	1433	AnyEvent::log 4 => "Unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@";
1255	}	1434	}
1256	}	1435	}
1257		1436
1258	# check for already loaded models	1437	# check for already loaded models
1259	unless ($MODEL) {	1438	unless ($MODEL) {
1260	for (@REGISTRY, @models) {	1439	for (@REGISTRY, @models) {
1261	my ($package, $model) = @$_;	1440	my ($package, $model) = @$_;
1262	if (${"$package\::VERSION"} > 0) {	1441	if (${"$package\::VERSION"} > 0) {
1263	if (eval "require $model") {	1442	if (eval "require $model") {
		1443	AnyEvent::log 7 => "Autodetected model '$model', using it.";
1264	$MODEL = $model;	1444	$MODEL = $model;
1265	warn "AnyEvent: autodetected model '$model', using it.\n" if $VERBOSE >= 2;	1445	last;
		1446	} else {
		1447	AnyEvent::log 8 => "Detected event loop $package, but cannot load '$model', skipping: $@";
		1448	}
		1449	}
		1450	}
		1451
		1452	unless ($MODEL) {
		1453	# try to autoload a model
		1454	for (@REGISTRY, @models) {
		1455	my ($package, $model) = @$_;
		1456	if (
		1457	eval "require $package"
		1458	and ${"$package\::VERSION"} > 0
		1459	and eval "require $model"
		1460	) {
		1461	AnyEvent::log 7 => "Autoloaded model '$model', using it.";
		1462	$MODEL = $model;
1266	last;	1463	last;
1267	}	1464	}
1268	}	1465	}
1269	}
1270
1271	unless ($MODEL) {
1272	# try to autoload a model
1273	for (@REGISTRY, @models) {
1274	my ($package, $model, $autoload) = @$_;
1275	if (
1276	$autoload
1277	and eval "require $package"
1278	and ${"$package\::VERSION"} > 0
1279	and eval "require $model"
1280	) {
1281	$MODEL = $model;
1282	warn "AnyEvent: autoloaded model '$model', using it.\n" if $VERBOSE >= 2;
1283	last;
1284	}
1285	}
1286		1466
1287	$MODEL	1467	$MODEL
1288	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.\n";	1468	or AnyEvent::log fatal => "Backend autodetection failed - did you properly install AnyEvent?";
1289	}	1469	}
1290	}	1470	}
1291		1471
1292	@models = (); # free probe data	1472	# free memory only needed for probing
		1473	undef @models;
		1474	undef @REGISTRY;
1293		1475
1294	push @{"$MODEL\::ISA"}, "AnyEvent::Base";	1476	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
1295	unshift @ISA, $MODEL;
1296		1477
1297	# now nuke some methods that are overriden by the backend.	1478	# now nuke some methods that are overridden by the backend.
1298	# SUPER is not allowed.	1479	# SUPER usage is not allowed in these.
1299	for (qw(time signal child idle)) {	1480	for (qw(time signal child idle)) {
1300	undef &{"AnyEvent::Base::$_"}	1481	undef &{"AnyEvent::Base::$_"}
1301	if defined &{"$MODEL\::$_"};	1482	if defined &{"$MODEL\::$_"};
1302	}	1483	}
1303		1484
1304	require AnyEvent::Strict if $ENV{PERL_ANYEVENT_STRICT};	1485	_isa_set;
		1486
		1487	# we're officially open!
		1488
		1489	if ($ENV{PERL_ANYEVENT_STRICT}) {
		1490	require AnyEvent::Strict;
		1491	}
		1492
		1493	if ($ENV{PERL_ANYEVENT_DEBUG_WRAP}) {
		1494	require AnyEvent::Debug;
		1495	AnyEvent::Debug::wrap ($ENV{PERL_ANYEVENT_DEBUG_WRAP});
		1496	}
		1497
		1498	if (length $ENV{PERL_ANYEVENT_DEBUG_SHELL}) {
		1499	require AnyEvent::Socket;
		1500	require AnyEvent::Debug;
		1501
		1502	my $shell = $ENV{PERL_ANYEVENT_DEBUG_SHELL};
		1503	$shell =~ s/\$\$/$$/g;
		1504
		1505	my ($host, $service) = AnyEvent::Socket::parse_hostport ($shell);
		1506	$AnyEvent::Debug::SHELL = AnyEvent::Debug::shell ($host, $service);
		1507	}
		1508
		1509	# now the anyevent environment is set up as the user told us to, so
		1510	# call the actual user code - post detects
1305		1511
1306	(shift @post_detect)->() while @post_detect;	1512	(shift @post_detect)->() while @post_detect;
		1513	undef @post_detect;
1307		1514
1308	*post_detect = sub(&) {	1515	*post_detect = sub(&) {
1309	shift->();	1516	shift->();
1310		1517
1311	undef	1518	undef
1312	};	1519	};
1313		1520
1314	$MODEL	1521	$MODEL
1315	}	1522	}
1316		1523
1317	sub AUTOLOAD {	1524	for my $name (@methods) {
1318	(my $func = $AUTOLOAD) =~ s/.*://;	1525	*$name = sub {
1319
1320	$method{$func}
1321	or Carp::croak "$func: not a valid AnyEvent class method";
1322
1323	detect;	1526	detect;
1324		1527	# we use goto because
1325	my $class = shift;	1528	# a) it makes the thunk more transparent
1326	$class->$func (@_);	1529	# b) it allows us to delete the thunk later
		1530	goto &{ UNIVERSAL::can AnyEvent => "SUPER::$name" }
		1531	};
1327	}	1532	}
1328		1533
1329	# utility function to dup a filehandle. this is used by many backends	1534	# utility function to dup a filehandle. this is used by many backends
1330	# to support binding more than one watcher per filehandle (they usually	1535	# to support binding more than one watcher per filehandle (they usually
1331	# allow only one watcher per fd, so we dup it to get a different one).	1536	# allow only one watcher per fd, so we dup it to get a different one).
…		…
1355		1560
1356	package AE;	1561	package AE;
1357		1562
1358	our $VERSION = $AnyEvent::VERSION;	1563	our $VERSION = $AnyEvent::VERSION;
1359		1564
		1565	sub _reset() {
		1566	eval q{
1360	# fall back to the main API by default - backends and AnyEvent::Base	1567	# fall back to the main API by default - backends and AnyEvent::Base
1361	# implementations can overwrite these.	1568	# implementations can overwrite these.
1362		1569
1363	sub io($$$) {	1570	sub io($$$) {
1364	AnyEvent->io (fh => $_[0], poll => $_[1] ? "w" : "r", cb => $_[2])	1571	AnyEvent->io (fh => $_[0], poll => $_[1] ? "w" : "r", cb => $_[2])
1365	}	1572	}
1366		1573
1367	sub timer($$$) {	1574	sub timer($$$) {
1368	AnyEvent->timer (after => $_[0], interval => $_[1], cb => $_[2])	1575	AnyEvent->timer (after => $_[0], interval => $_[1], cb => $_[2])
1369	}	1576	}
1370		1577
1371	sub signal($$) {	1578	sub signal($$) {
1372	AnyEvent->signal (signal => $_[0], cb => $_[1])	1579	AnyEvent->signal (signal => $_[0], cb => $_[1])
1373	}	1580	}
1374		1581
1375	sub child($$) {	1582	sub child($$) {
1376	AnyEvent->child (pid => $_[0], cb => $_[1])	1583	AnyEvent->child (pid => $_[0], cb => $_[1])
1377	}	1584	}
1378		1585
1379	sub idle($) {	1586	sub idle($) {
1380	AnyEvent->idle (cb => $_[0])	1587	AnyEvent->idle (cb => $_[0]);
1381	}	1588	}
1382		1589
1383	sub cv(;&) {	1590	sub cv(;&) {
1384	AnyEvent->condvar (@_ ? (cb => $_[0]) : ())	1591	AnyEvent->condvar (@_ ? (cb => $_[0]) : ())
1385	}	1592	}
1386		1593
1387	sub now() {	1594	sub now() {
1388	AnyEvent->now	1595	AnyEvent->now
1389	}	1596	}
1390		1597
1391	sub now_update() {	1598	sub now_update() {
1392	AnyEvent->now_update	1599	AnyEvent->now_update
1393	}	1600	}
1394		1601
1395	sub time() {	1602	sub time() {
1396	AnyEvent->time	1603	AnyEvent->time
		1604	}
		1605
		1606	*postpone = \&AnyEvent::postpone;
		1607	*log = \&AnyEvent::log;
		1608	};
		1609	die if $@;
1397	}	1610	}
		1611
		1612	BEGIN { _reset }
1398		1613
1399	package AnyEvent::Base;	1614	package AnyEvent::Base;
1400		1615
1401	# default implementations for many methods	1616	# default implementations for many methods
1402		1617
1403	sub time {	1618	sub time {
1404	eval q{ # poor man's autoloading {}	1619	eval q{ # poor man's autoloading {}
1405	# probe for availability of Time::HiRes	1620	# probe for availability of Time::HiRes
1406	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {	1621	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {
1407	warn "AnyEvent: using Time::HiRes for sub-second timing accuracy.\n" if $VERBOSE >= 8;	1622	*time = sub { Time::HiRes::time () };
1408	*AE::time = \&Time::HiRes::time;	1623	*AE::time = \& Time::HiRes::time ;
		1624	*now = \&time;
		1625	AnyEvent::log 8 => "using Time::HiRes for sub-second timing accuracy.";
1409	# if (eval "use POSIX (); (POSIX::times())...	1626	# if (eval "use POSIX (); (POSIX::times())...
1410	} else {	1627	} else {
1411	warn "AnyEvent: using built-in time(), WARNING, no sub-second resolution!\n" if $VERBOSE;	1628	*time = sub { CORE::time };
1412	*AE::time = sub (){ time }; # epic fail	1629	*AE::time = sub (){ CORE::time };
		1630	*now = \&time;
		1631	AnyEvent::log 3 => "Using built-in time(), no sub-second resolution!";
1413	}	1632	}
1414
1415	*time = sub { AE::time }; # different prototypes
1416	};	1633	};
1417	die if $@;	1634	die if $@;
1418		1635
1419	&time	1636	&time
1420	}	1637	}
1421		1638
1422	*now = \&time;	1639	*now = \&time;
1423
1424	sub now_update { }	1640	sub now_update { }
1425		1641
		1642	sub _poll {
		1643	Carp::croak "$AnyEvent::MODEL does not support blocking waits. Caught";
		1644	}
		1645
1426	# default implementation for ->condvar	1646	# default implementation for ->condvar
		1647	# in fact, the default should not be overwritten
1427		1648
1428	sub condvar {	1649	sub condvar {
1429	eval q{ # poor man's autoloading {}	1650	eval q{ # poor man's autoloading {}
1430	*condvar = sub {	1651	*condvar = sub {
1431	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"	1652	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"
…		…
1509		1730
1510	sub signal {	1731	sub signal {
1511	eval q{ # poor man's autoloading {}	1732	eval q{ # poor man's autoloading {}
1512	# probe for availability of Async::Interrupt	1733	# probe for availability of Async::Interrupt
1513	if (_have_async_interrupt) {	1734	if (_have_async_interrupt) {
1514	warn "AnyEvent: using Async::Interrupt for race-free signal handling.\n" if $VERBOSE >= 8;	1735	AnyEvent::log 8 => "Using Async::Interrupt for race-free signal handling.";
1515		1736
1516	$SIGPIPE_R = new Async::Interrupt::EventPipe;	1737	$SIGPIPE_R = new Async::Interrupt::EventPipe;
1517	$SIG_IO = AE::io $SIGPIPE_R->fileno, 0, \&_signal_exec;	1738	$SIG_IO = AE::io $SIGPIPE_R->fileno, 0, \&_signal_exec;
1518		1739
1519	} else {	1740	} else {
1520	warn "AnyEvent: using emulated perl signal handling with latency timer.\n" if $VERBOSE >= 8;	1741	AnyEvent::log 8 => "Using emulated perl signal handling with latency timer.";
1521		1742
1522	if (AnyEvent::WIN32) {	1743	if (AnyEvent::WIN32) {
1523	require AnyEvent::Util;	1744	require AnyEvent::Util;
1524		1745
1525	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();	1746	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
…		…
1601	: sysread $SIGPIPE_R, (my $dummy), 9;	1822	: sysread $SIGPIPE_R, (my $dummy), 9;
1602		1823
1603	while (%SIG_EV) {	1824	while (%SIG_EV) {
1604	for (keys %SIG_EV) {	1825	for (keys %SIG_EV) {
1605	delete $SIG_EV{$_};	1826	delete $SIG_EV{$_};
1606	$_->() for values %{ $SIG_CB{$_} || {} };	1827	&$_ for values %{ $SIG_CB{$_} || {} };
1607	}	1828	}
1608	}	1829	}
1609	};	1830	};
1610	};	1831	};
1611	die if $@;	1832	die if $@;
…		…
1616	# default implementation for ->child	1837	# default implementation for ->child
1617		1838
1618	our %PID_CB;	1839	our %PID_CB;
1619	our $CHLD_W;	1840	our $CHLD_W;
1620	our $CHLD_DELAY_W;	1841	our $CHLD_DELAY_W;
1621	our $WNOHANG;
1622		1842
1623	# used by many Impl's	1843	# used by many Impl's
1624	sub _emit_childstatus($$) {	1844	sub _emit_childstatus($$) {
1625	my (undef, $rpid, $rstatus) = @_;	1845	my (undef, $rpid, $rstatus) = @_;
1626		1846
…		…
1633	eval q{ # poor man's autoloading {}	1853	eval q{ # poor man's autoloading {}
1634	*_sigchld = sub {	1854	*_sigchld = sub {
1635	my $pid;	1855	my $pid;
1636		1856
1637	AnyEvent->_emit_childstatus ($pid, $?)	1857	AnyEvent->_emit_childstatus ($pid, $?)
1638	while ($pid = waitpid -1, $WNOHANG) > 0;	1858	while ($pid = waitpid -1, WNOHANG) > 0;
1639	};	1859	};
1640		1860
1641	*child = sub {	1861	*child = sub {
1642	my (undef, %arg) = @_;	1862	my (undef, %arg) = @_;
1643		1863
1644	defined (my $pid = $arg{pid} + 0)	1864	my $pid = $arg{pid};
1645	or Carp::croak "required option 'pid' is missing";	1865	my $cb = $arg{cb};
1646		1866
1647	$PID_CB{$pid}{$arg{cb}} = $arg{cb};	1867	$PID_CB{$pid}{$cb+0} = $cb;
1648
1649	# WNOHANG is almost cetrainly 1 everywhere
1650	$WNOHANG ||= $^O =~ /^(?:openbsd|netbsd|linux|freebsd|cygwin|MSWin32)$/
1651	? 1
1652	: eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1;
1653		1868
1654	unless ($CHLD_W) {	1869	unless ($CHLD_W) {
1655	$CHLD_W = AE::signal CHLD => \&_sigchld;	1870	$CHLD_W = AE::signal CHLD => \&_sigchld;
1656	# child could be a zombie already, so make at least one round	1871	# child could be a zombie already, so make at least one round
1657	&_sigchld;	1872	&_sigchld;
1658	}	1873	}
1659		1874
1660	bless [$pid, $arg{cb}], "AnyEvent::Base::child"	1875	bless [$pid, $cb+0], "AnyEvent::Base::child"
1661	};	1876	};
1662		1877
1663	*AnyEvent::Base::child::DESTROY = sub {	1878	*AnyEvent::Base::child::DESTROY = sub {
1664	my ($pid, $cb) = @{$_[0]};	1879	my ($pid, $icb) = @{$_[0]};
1665		1880
1666	delete $PID_CB{$pid}{$cb};	1881	delete $PID_CB{$pid}{$icb};
1667	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };	1882	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };
1668		1883
1669	undef $CHLD_W unless keys %PID_CB;	1884	undef $CHLD_W unless keys %PID_CB;
1670	};	1885	};
1671	};	1886	};
…		…
1684		1899
1685	my ($cb, $w, $rcb) = $arg{cb};	1900	my ($cb, $w, $rcb) = $arg{cb};
1686		1901
1687	$rcb = sub {	1902	$rcb = sub {
1688	if ($cb) {	1903	if ($cb) {
1689	$w = _time;	1904	$w = AE::time;
1690	&$cb;	1905	&$cb;
1691	$w = _time - $w;	1906	$w = AE::time - $w;
1692		1907
1693	# never use more then 50% of the time for the idle watcher,	1908	# never use more then 50% of the time for the idle watcher,
1694	# within some limits	1909	# within some limits
1695	$w = 0.0001 if $w < 0.0001;	1910	$w = 0.0001 if $w < 0.0001;
1696	$w = 5 if $w > 5;	1911	$w = 5 if $w > 5;
…		…
1719		1934
1720	package AnyEvent::CondVar;	1935	package AnyEvent::CondVar;
1721		1936
1722	our @ISA = AnyEvent::CondVar::Base::;	1937	our @ISA = AnyEvent::CondVar::Base::;
1723		1938
		1939	# only to be used for subclassing
		1940	sub new {
		1941	my $class = shift;
		1942	bless AnyEvent->condvar (@_), $class
		1943	}
		1944
1724	package AnyEvent::CondVar::Base;	1945	package AnyEvent::CondVar::Base;
1725		1946
1726	#use overload	1947	#use overload
1727	# '&{}' => sub { my $self = shift; sub { $self->send (@_) } },	1948	# '&{}' => sub { my $self = shift; sub { $self->send (@_) } },
1728	# fallback => 1;	1949	# fallback => 1;
…		…
1737		1958
1738	sub _send {	1959	sub _send {
1739	# nop	1960	# nop
1740	}	1961	}
1741		1962
		1963	sub _wait {
		1964	AnyEvent->_poll until $_[0]{_ae_sent};
		1965	}
		1966
1742	sub send {	1967	sub send {
1743	my $cv = shift;	1968	my $cv = shift;
1744	$cv->{_ae_sent} = [@_];	1969	$cv->{_ae_sent} = [@_];
1745	(delete $cv->{_ae_cb})->($cv) if $cv->{_ae_cb};	1970	(delete $cv->{_ae_cb})->($cv) if $cv->{_ae_cb};
1746	$cv->_send;	1971	$cv->_send;
…		…
1753		1978
1754	sub ready {	1979	sub ready {
1755	$_[0]{_ae_sent}	1980	$_[0]{_ae_sent}
1756	}	1981	}
1757		1982
1758	sub _wait {
1759	$WAITING
1760	and !$_[0]{_ae_sent}
1761	and Carp::croak "AnyEvent::CondVar: recursive blocking wait detected";
1762
1763	local $WAITING = 1;
1764	AnyEvent->one_event while !$_[0]{_ae_sent};
1765	}
1766
1767	sub recv {	1983	sub recv {
		1984	unless ($_[0]{_ae_sent}) {
		1985	$WAITING
		1986	and Carp::croak "AnyEvent::CondVar: recursive blocking wait attempted";
		1987
		1988	local $WAITING = 1;
1768	$_[0]->_wait;	1989	$_[0]->_wait;
		1990	}
1769		1991
1770	Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak};	1992	$_[0]{_ae_croak}
1771	wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0]	1993	and Carp::croak $_[0]{_ae_croak};
		1994
		1995	wantarray
		1996	? @{ $_[0]{_ae_sent} }
		1997	: $_[0]{_ae_sent}[0]
1772	}	1998	}
1773		1999
1774	sub cb {	2000	sub cb {
1775	my $cv = shift;	2001	my $cv = shift;
1776		2002
…		…
1792	&{ $_[0]{_ae_end_cb} || sub { $_[0]->send } };	2018	&{ $_[0]{_ae_end_cb} || sub { $_[0]->send } };
1793	}	2019	}
1794		2020
1795	# undocumented/compatibility with pre-3.4	2021	# undocumented/compatibility with pre-3.4
1796	*broadcast = \&send;	2022	*broadcast = \&send;
1797	*wait = \&_wait;	2023	*wait = \&recv;
1798		2024
1799	=head1 ERROR AND EXCEPTION HANDLING	2025	=head1 ERROR AND EXCEPTION HANDLING
1800		2026
1801	In general, AnyEvent does not do any error handling - it relies on the	2027	In general, AnyEvent does not do any error handling - it relies on the
1802	caller to do that if required. The L<AnyEvent::Strict> module (see also	2028	caller to do that if required. The L<AnyEvent::Strict> module (see also
…		…
1814	$Event/EV::DIED->() >>, L<Glib> uses C<< install_exception_handler >> and	2040	$Event/EV::DIED->() >>, L<Glib> uses C<< install_exception_handler >> and
1815	so on.	2041	so on.
1816		2042
1817	=head1 ENVIRONMENT VARIABLES	2043	=head1 ENVIRONMENT VARIABLES
1818		2044
1819	The following environment variables are used by this module or its	2045	AnyEvent supports a number of environment variables that tune the
1820	submodules.	2046	runtime behaviour. They are usually evaluated when AnyEvent is
		2047	loaded, initialised, or a submodule that uses them is loaded. Many of
		2048	them also cause AnyEvent to load additional modules - for example,
		2049	C<PERL_ANYEVENT_DEBUG_WRAP> causes the L<AnyEvent::Debug> module to be
		2050	loaded.
1821		2051
1822	Note that AnyEvent will remove I<all> environment variables starting with	2052	All the environment variables documented here start with
1823	C<PERL_ANYEVENT_> from C<%ENV> when it is loaded while taint mode is	2053	C<PERL_ANYEVENT_>, which is what AnyEvent considers its own
1824	enabled.	2054	namespace. Other modules are encouraged (but by no means required) to use
		2055	C<PERL_ANYEVENT_SUBMODULE> if they have registered the AnyEvent::Submodule
		2056	namespace on CPAN, for any submodule. For example, L<AnyEvent::HTTP> could
		2057	be expected to use C<PERL_ANYEVENT_HTTP_PROXY> (it should not access env
		2058	variables starting with C<AE_>, see below).
		2059
		2060	All variables can also be set via the C<AE_> prefix, that is, instead
		2061	of setting C<PERL_ANYEVENT_VERBOSE> you can also set C<AE_VERBOSE>. In
		2062	case there is a clash btween anyevent and another program that uses
		2063	C<AE_something> you can set the corresponding C<PERL_ANYEVENT_something>
		2064	variable to the empty string, as those variables take precedence.
		2065
		2066	When AnyEvent is first loaded, it copies all C<AE_xxx> env variables
		2067	to their C<PERL_ANYEVENT_xxx> counterpart unless that variable already
		2068	exists. If taint mode is on, then AnyEvent will remove I<all> environment
		2069	variables starting with C<PERL_ANYEVENT_> from C<%ENV> (or replace them
		2070	with C<undef> or the empty string, if the corresaponding C<AE_> variable
		2071	is set).
		2072
		2073	The exact algorithm is currently:
		2074
		2075	1. if taint mode enabled, delete all PERL_ANYEVENT_xyz variables from %ENV
		2076	2. copy over AE_xyz to PERL_ANYEVENT_xyz unless the latter alraedy exists
		2077	3. if taint mode enabled, set all PERL_ANYEVENT_xyz variables to undef.
		2078
		2079	This ensures that child processes will not see the C<AE_> variables.
		2080
		2081	The following environment variables are currently known to AnyEvent:
1825		2082
1826	=over 4	2083	=over 4
1827		2084
1828	=item C<PERL_ANYEVENT_VERBOSE>	2085	=item C<PERL_ANYEVENT_VERBOSE>
1829		2086
1830	By default, AnyEvent will be completely silent except in fatal	2087	By default, AnyEvent will log messages with loglevel C<4> (C<error>) or
1831	conditions. You can set this environment variable to make AnyEvent more	2088	higher (see L<AnyEvent::Log>). You can set this environment variable to a
1832	talkative.	2089	numerical loglevel to make AnyEvent more (or less) talkative.
1833		2090
		2091	If you want to do more than just set the global logging level
		2092	you should have a look at C<PERL_ANYEVENT_LOG>, which allows much more
		2093	complex specifications.
		2094
		2095	When set to C<0> (C<off>), then no messages whatsoever will be logged with
		2096	everything else at defaults.
		2097
1834	When set to C<1> or higher, causes AnyEvent to warn about unexpected	2098	When set to C<5> or higher (C<warn>), AnyEvent warns about unexpected
1835	conditions, such as not being able to load the event model specified by	2099	conditions, such as not being able to load the event model specified by
1836	C<PERL_ANYEVENT_MODEL>.	2100	C<PERL_ANYEVENT_MODEL>, or a guard callback throwing an exception - this
		2101	is the minimum recommended level for use during development.
1837		2102
1838	When set to C<2> or higher, cause AnyEvent to report to STDERR which event	2103	When set to C<7> or higher (info), AnyEvent reports which event model it
1839	model it chooses.	2104	chooses.
1840		2105
1841	When set to C<8> or higher, then AnyEvent will report extra information on	2106	When set to C<8> or higher (debug), then AnyEvent will report extra
1842	which optional modules it loads and how it implements certain features.	2107	information on which optional modules it loads and how it implements
		2108	certain features.
		2109
		2110	=item C<PERL_ANYEVENT_LOG>
		2111
		2112	Accepts rather complex logging specifications. For example, you could log
		2113	all C<debug> messages of some module to stderr, warnings and above to
		2114	stderr, and errors and above to syslog, with:
		2115
		2116	PERL_ANYEVENT_LOG=Some::Module=debug,+log:filter=warn,+%syslog:%syslog=error,syslog
		2117
		2118	For the rather extensive details, see L<AnyEvent::Log>.
		2119
		2120	This variable is evaluated when AnyEvent (or L<AnyEvent::Log>) is loaded,
		2121	so will take effect even before AnyEvent has initialised itself.
		2122
		2123	Note that specifying this environment variable causes the L<AnyEvent::Log>
		2124	module to be loaded, while C<PERL_ANYEVENT_VERBOSE> does not, so only
		2125	using the latter saves a few hundred kB of memory unless a module
		2126	explicitly needs the extra features of AnyEvent::Log.
1843		2127
1844	=item C<PERL_ANYEVENT_STRICT>	2128	=item C<PERL_ANYEVENT_STRICT>
1845		2129
1846	AnyEvent does not do much argument checking by default, as thorough	2130	AnyEvent does not do much argument checking by default, as thorough
1847	argument checking is very costly. Setting this variable to a true value	2131	argument checking is very costly. Setting this variable to a true value
…		…
1849	check the arguments passed to most method calls. If it finds any problems,	2133	check the arguments passed to most method calls. If it finds any problems,
1850	it will croak.	2134	it will croak.
1851		2135
1852	In other words, enables "strict" mode.	2136	In other words, enables "strict" mode.
1853		2137
1854	Unlike C<use strict> (or it's modern cousin, C<< use L<common::sense>	2138	Unlike C<use strict> (or its modern cousin, C<< use L<common::sense>
1855	>>, it is definitely recommended to keep it off in production. Keeping	2139	>>, it is definitely recommended to keep it off in production. Keeping
1856	C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs	2140	C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs
1857	can be very useful, however.	2141	can be very useful, however.
1858		2142
		2143	=item C<PERL_ANYEVENT_DEBUG_SHELL>
		2144
		2145	If this env variable is nonempty, then its contents will be interpreted by
		2146	C<AnyEvent::Socket::parse_hostport> and C<AnyEvent::Debug::shell> (after
		2147	replacing every occurance of C<$$> by the process pid). The shell object
		2148	is saved in C<$AnyEvent::Debug::SHELL>.
		2149
		2150	This happens when the first watcher is created.
		2151
		2152	For example, to bind a debug shell on a unix domain socket in
		2153	F<< /tmp/debug<pid>.sock >>, you could use this:
		2154
		2155	PERL_ANYEVENT_DEBUG_SHELL=/tmp/debug\$\$.sock perlprog
		2156	# connect with e.g.: socat readline /tmp/debug123.sock
		2157
		2158	Or to bind to tcp port 4545 on localhost:
		2159
		2160	PERL_ANYEVENT_DEBUG_SHELL=127.0.0.1:4545 perlprog
		2161	# connect with e.g.: telnet localhost 4545
		2162
		2163	Note that creating sockets in F</tmp> or on localhost is very unsafe on
		2164	multiuser systems.
		2165
		2166	=item C<PERL_ANYEVENT_DEBUG_WRAP>
		2167
		2168	Can be set to C<0>, C<1> or C<2> and enables wrapping of all watchers for
		2169	debugging purposes. See C<AnyEvent::Debug::wrap> for details.
		2170
1859	=item C<PERL_ANYEVENT_MODEL>	2171	=item C<PERL_ANYEVENT_MODEL>
1860		2172
1861	This can be used to specify the event model to be used by AnyEvent, before	2173	This can be used to specify the event model to be used by AnyEvent, before
1862	auto detection and -probing kicks in. It must be a string consisting	2174	auto detection and -probing kicks in.
1863	entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended	2175
		2176	It normally is a string consisting entirely of ASCII letters (e.g. C<EV>
		2177	or C<IOAsync>). The string C<AnyEvent::Impl::> gets prepended and the
1864	and the resulting module name is loaded and if the load was successful,	2178	resulting module name is loaded and - if the load was successful - used as
1865	used as event model. If it fails to load AnyEvent will proceed with	2179	event model backend. If it fails to load then AnyEvent will proceed with
1866	auto detection and -probing.	2180	auto detection and -probing.
1867		2181
1868	This functionality might change in future versions.	2182	If the string ends with C<::> instead (e.g. C<AnyEvent::Impl::EV::>) then
		2183	nothing gets prepended and the module name is used as-is (hint: C<::> at
		2184	the end of a string designates a module name and quotes it appropriately).
1869		2185
1870	For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you	2186	For example, to force the pure perl model (L<AnyEvent::Loop::Perl>) you
1871	could start your program like this:	2187	could start your program like this:
1872		2188
1873	PERL_ANYEVENT_MODEL=Perl perl ...	2189	PERL_ANYEVENT_MODEL=Perl perl ...
		2190
		2191	=item C<PERL_ANYEVENT_IO_MODEL>
		2192
		2193	The current file I/O model - see L<AnyEvent::IO> for more info.
		2194
		2195	At the moment, only C<Perl> (small, pure-perl, synchronous) and
		2196	C<IOAIO> (truly asynchronous) are supported. The default is C<IOAIO> if
		2197	L<AnyEvent::AIO> can be loaded, otherwise it is C<Perl>.
1874		2198
1875	=item C<PERL_ANYEVENT_PROTOCOLS>	2199	=item C<PERL_ANYEVENT_PROTOCOLS>
1876		2200
1877	Used by both L<AnyEvent::DNS> and L<AnyEvent::Socket> to determine preferences	2201	Used by both L<AnyEvent::DNS> and L<AnyEvent::Socket> to determine preferences
1878	for IPv4 or IPv6. The default is unspecified (and might change, or be the result	2202	for IPv4 or IPv6. The default is unspecified (and might change, or be the result
…		…
1891	but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4>	2215	but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4>
1892	- only support IPv4, never try to resolve or contact IPv6	2216	- only support IPv4, never try to resolve or contact IPv6
1893	addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or	2217	addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or
1894	IPv6, but prefer IPv6 over IPv4.	2218	IPv6, but prefer IPv6 over IPv4.
1895		2219
		2220	=item C<PERL_ANYEVENT_HOSTS>
		2221
		2222	This variable, if specified, overrides the F</etc/hosts> file used by
		2223	L<AnyEvent::Socket>C<::resolve_sockaddr>, i.e. hosts aliases will be read
		2224	from that file instead.
		2225
1896	=item C<PERL_ANYEVENT_EDNS0>	2226	=item C<PERL_ANYEVENT_EDNS0>
1897		2227
1898	Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension	2228	Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension for
1899	for DNS. This extension is generally useful to reduce DNS traffic, but	2229	DNS. This extension is generally useful to reduce DNS traffic, especially
1900	some (broken) firewalls drop such DNS packets, which is why it is off by	2230	when DNSSEC is involved, but some (broken) firewalls drop such DNS
1901	default.	2231	packets, which is why it is off by default.
1902		2232
1903	Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce	2233	Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce
1904	EDNS0 in its DNS requests.	2234	EDNS0 in its DNS requests.
1905		2235
1906	=item C<PERL_ANYEVENT_MAX_FORKS>	2236	=item C<PERL_ANYEVENT_MAX_FORKS>
…		…
1912		2242
1913	The default value for the C<max_outstanding> parameter for the default DNS	2243	The default value for the C<max_outstanding> parameter for the default DNS
1914	resolver - this is the maximum number of parallel DNS requests that are	2244	resolver - this is the maximum number of parallel DNS requests that are
1915	sent to the DNS server.	2245	sent to the DNS server.
1916		2246
		2247	=item C<PERL_ANYEVENT_MAX_SIGNAL_LATENCY>
		2248
		2249	Perl has inherently racy signal handling (you can basically choose between
		2250	losing signals and memory corruption) - pure perl event loops (including
		2251	C<AnyEvent::Loop>, when C<Async::Interrupt> isn't available) therefore
		2252	have to poll regularly to avoid losing signals.
		2253
		2254	Some event loops are racy, but don't poll regularly, and some event loops
		2255	are written in C but are still racy. For those event loops, AnyEvent
		2256	installs a timer that regularly wakes up the event loop.
		2257
		2258	By default, the interval for this timer is C<10> seconds, but you can
		2259	override this delay with this environment variable (or by setting
		2260	the C<$AnyEvent::MAX_SIGNAL_LATENCY> variable before creating signal
		2261	watchers).
		2262
		2263	Lower values increase CPU (and energy) usage, higher values can introduce
		2264	long delays when reaping children or waiting for signals.
		2265
		2266	The L<AnyEvent::Async> module, if available, will be used to avoid this
		2267	polling (with most event loops).
		2268
1917	=item C<PERL_ANYEVENT_RESOLV_CONF>	2269	=item C<PERL_ANYEVENT_RESOLV_CONF>
1918		2270
1919	The file to use instead of F</etc/resolv.conf> (or OS-specific	2271	The absolute path to a F<resolv.conf>-style file to use instead of
1920	configuration) in the default resolver. When set to the empty string, no	2272	F</etc/resolv.conf> (or the OS-specific configuration) in the default
1921	default config will be used.	2273	resolver, or the empty string to select the default configuration.
1922		2274
1923	=item C<PERL_ANYEVENT_CA_FILE>, C<PERL_ANYEVENT_CA_PATH>.	2275	=item C<PERL_ANYEVENT_CA_FILE>, C<PERL_ANYEVENT_CA_PATH>.
1924		2276
1925	When neither C<ca_file> nor C<ca_path> was specified during	2277	When neither C<ca_file> nor C<ca_path> was specified during
1926	L<AnyEvent::TLS> context creation, and either of these environment	2278	L<AnyEvent::TLS> context creation, and either of these environment
1927	variables exist, they will be used to specify CA certificate locations	2279	variables are nonempty, they will be used to specify CA certificate
1928	instead of a system-dependent default.	2280	locations instead of a system-dependent default.
1929		2281
1930	=item C<PERL_ANYEVENT_AVOID_GUARD> and C<PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT>	2282	=item C<PERL_ANYEVENT_AVOID_GUARD> and C<PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT>
1931		2283
1932	When these are set to C<1>, then the respective modules are not	2284	When these are set to C<1>, then the respective modules are not
1933	loaded. Mostly good for testing AnyEvent itself.	2285	loaded. Mostly good for testing AnyEvent itself.
…		…
2265	(even when used without AnyEvent), but most event loops have acceptable	2617	(even when used without AnyEvent), but most event loops have acceptable
2266	performance with or without AnyEvent.	2618	performance with or without AnyEvent.
2267		2619
2268	=item * The overhead AnyEvent adds is usually much smaller than the overhead of	2620	=item * The overhead AnyEvent adds is usually much smaller than the overhead of
2269	the actual event loop, only with extremely fast event loops such as EV	2621	the actual event loop, only with extremely fast event loops such as EV
2270	adds AnyEvent significant overhead.	2622	does AnyEvent add significant overhead.
2271		2623
2272	=item * You should avoid POE like the plague if you want performance or	2624	=item * You should avoid POE like the plague if you want performance or
2273	reasonable memory usage.	2625	reasonable memory usage.
2274		2626
2275	=back	2627	=back
…		…
2505	unless defined $SIG{PIPE};	2857	unless defined $SIG{PIPE};
2506		2858
2507	=head1 RECOMMENDED/OPTIONAL MODULES	2859	=head1 RECOMMENDED/OPTIONAL MODULES
2508		2860
2509	One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and	2861	One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and
2510	it's built-in modules) are required to use it.	2862	its built-in modules) are required to use it.
2511		2863
2512	That does not mean that AnyEvent won't take advantage of some additional	2864	That does not mean that AnyEvent won't take advantage of some additional
2513	modules if they are installed.	2865	modules if they are installed.
2514		2866
2515	This section explains which additional modules will be used, and how they	2867	This section explains which additional modules will be used, and how they
…		…
2573	the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL.	2925	the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL.
2574		2926
2575	=item L<Time::HiRes>	2927	=item L<Time::HiRes>
2576		2928
2577	This module is part of perl since release 5.008. It will be used when the	2929	This module is part of perl since release 5.008. It will be used when the
2578	chosen event library does not come with a timing source on it's own. The	2930	chosen event library does not come with a timing source of its own. The
2579	pure-perl event loop (L<AnyEvent::Impl::Perl>) will additionally use it to	2931	pure-perl event loop (L<AnyEvent::Loop>) will additionally load it to
2580	try to use a monotonic clock for timing stability.	2932	try to use a monotonic clock for timing stability.
2581		2933
2582	=back	2934	=back
2583		2935
2584		2936
…		…
2646	pronounced).	2998	pronounced).
2647		2999
2648		3000
2649	=head1 SEE ALSO	3001	=head1 SEE ALSO
2650		3002
2651	Utility functions: L<AnyEvent::Util>.	3003	Tutorial/Introduction: L<AnyEvent::Intro>.
2652		3004
2653	Event modules: L<EV>, L<EV::Glib>, L<Glib::EV>, L<Event>, L<Glib::Event>,	3005	FAQ: L<AnyEvent::FAQ>.
2654	L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.	3006
		3007	Utility functions: L<AnyEvent::Util> (misc. grab-bag), L<AnyEvent::Log>
		3008	(simply logging).
		3009
		3010	Development/Debugging: L<AnyEvent::Strict> (stricter checking),
		3011	L<AnyEvent::Debug> (interactive shell, watcher tracing).
		3012
		3013	Supported event modules: L<AnyEvent::Loop>, L<EV>, L<EV::Glib>,
		3014	L<Glib::EV>, L<Event>, L<Glib::Event>, L<Glib>, L<Tk>, L<Event::Lib>,
		3015	L<Qt>, L<POE>, L<FLTK>.
2655		3016
2656	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,	3017	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,
2657	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,	3018	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,
2658	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,	3019	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,
2659	L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>, L<Anyevent::Impl::Irssi>.	3020	L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>, L<Anyevent::Impl::Irssi>,
		3021	L<AnyEvent::Impl::FLTK>.
2660		3022
2661	Non-blocking file handles, sockets, TCP clients and	3023	Non-blocking handles, pipes, stream sockets, TCP clients and
2662	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.	3024	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.
2663		3025
		3026	Asynchronous File I/O: L<AnyEvent::IO>.
		3027
2664	Asynchronous DNS: L<AnyEvent::DNS>.	3028	Asynchronous DNS: L<AnyEvent::DNS>.
2665		3029
2666	Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>,	3030	Thread support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>.
2667	L<Coro::Event>,
2668		3031
2669	Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::XMPP>,	3032	Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::IRC>,
2670	L<AnyEvent::HTTP>.	3033	L<AnyEvent::HTTP>.
2671		3034
2672		3035
2673	=head1 AUTHOR	3036	=head1 AUTHOR
2674		3037
2675	Marc Lehmann <schmorp@schmorp.de>	3038	Marc Lehmann <schmorp@schmorp.de>
2676	http://home.schmorp.de/	3039	http://anyevent.schmorp.de
2677		3040
2678	=cut	3041	=cut
2679		3042
2680	1	3043	1
2681		3044

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