ViewVC Help

View File | Revision Log | Show Annotations | Download File

/cvs/AnyEvent/lib/AnyEvent.pm

Comparing AnyEvent/lib/AnyEvent.pm (file contents):
Revision 1.312 by root, Mon Feb 15 18:02:35 2010 UTC vs.
Revision 1.387 by root, Sat Oct 1 22:39:29 2011 UTC

1	=head1 NAME	1	=head1 NAME
2		2
3	AnyEvent - the DBI of event loop programming	3	AnyEvent - the DBI of event loop programming
4		4
5	EV, Event, Glib, Tk, Perl, Event::Lib, Irssi, rxvt-unicode, IO::Async, Qt	5	EV, Event, Glib, Tk, Perl, Event::Lib, Irssi, rxvt-unicode, IO::Async, Qt,
6	and POE are various supported event loops/environments.	6	FLTK and POE are various supported event loops/environments.
7		7
8	=head1 SYNOPSIS	8	=head1 SYNOPSIS
9		9
10	use AnyEvent;	10	use AnyEvent;
11		11
		12	# if you prefer function calls, look at the AE manpage for
		13	# an alternative API.
		14
12	# file descriptor readable	15	# file handle or descriptor readable
13	my $w = AnyEvent->io (fh => $fh, poll => "r", cb => sub { ... });	16	my $w = AnyEvent->io (fh => $fh, poll => "r", cb => sub { ... });
14		17
15	# one-shot or repeating timers	18	# one-shot or repeating timers
16	my $w = AnyEvent->timer (after => $seconds, cb => sub { ... });	19	my $w = AnyEvent->timer (after => $seconds, cb => sub { ... });
17	my $w = AnyEvent->timer (after => $seconds, interval => $seconds, cb => ...	20	my $w = AnyEvent->timer (after => $seconds, interval => $seconds, cb => ...);
18		21
19	print AnyEvent->now; # prints current event loop time	22	print AnyEvent->now; # prints current event loop time
20	print AnyEvent->time; # think Time::HiRes::time or simply CORE::time.	23	print AnyEvent->time; # think Time::HiRes::time or simply CORE::time.
21		24
22	# POSIX signal	25	# POSIX signal
…		…
43	in a tutorial or some gentle introduction, have a look at the	46	in a tutorial or some gentle introduction, have a look at the
44	L<AnyEvent::Intro> manpage.	47	L<AnyEvent::Intro> manpage.
45		48
46	=head1 SUPPORT	49	=head1 SUPPORT
47		50
		51	An FAQ document is available as L<AnyEvent::FAQ>.
		52
48	There is a mailinglist for discussing all things AnyEvent, and an IRC	53	There also is a mailinglist for discussing all things AnyEvent, and an IRC
49	channel, too.	54	channel, too.
50		55
51	See the AnyEvent project page at the B<Schmorpforge Ta-Sa Software	56	See the AnyEvent project page at the B<Schmorpforge Ta-Sa Software
52	Repository>, at L<http://anyevent.schmorp.de>, for more info.	57	Repository>, at L<http://anyevent.schmorp.de>, for more info.
53		58
…		…
73	module users into the same thing by forcing them to use the same event	78	module users into the same thing by forcing them to use the same event
74	model you use.	79	model you use.
75		80
76	For modules like POE or IO::Async (which is a total misnomer as it is	81	For modules like POE or IO::Async (which is a total misnomer as it is
77	actually doing all I/O I<synchronously>...), using them in your module is	82	actually doing all I/O I<synchronously>...), using them in your module is
78	like joining a cult: After you joined, you are dependent on them and you	83	like joining a cult: After you join, you are dependent on them and you
79	cannot use anything else, as they are simply incompatible to everything	84	cannot use anything else, as they are simply incompatible to everything
80	that isn't them. What's worse, all the potential users of your	85	that isn't them. What's worse, all the potential users of your
81	module are I<also> forced to use the same event loop you use.	86	module are I<also> forced to use the same event loop you use.
82		87
83	AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works	88	AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works
84	fine. AnyEvent + Tk works fine etc. etc. but none of these work together	89	fine. AnyEvent + Tk works fine etc. etc. but none of these work together
85	with the rest: POE + IO::Async? No go. Tk + Event? No go. Again: if	90	with the rest: POE + EV? No go. Tk + Event? No go. Again: if your module
86	your module uses one of those, every user of your module has to use it,	91	uses one of those, every user of your module has to use it, too. But if
87	too. But if your module uses AnyEvent, it works transparently with all	92	your module uses AnyEvent, it works transparently with all event models it
88	event models it supports (including stuff like IO::Async, as long as those	93	supports (including stuff like IO::Async, as long as those use one of the
89	use one of the supported event loops. It is trivial to add new event loops	94	supported event loops. It is easy to add new event loops to AnyEvent, too,
90	to AnyEvent, too, so it is future-proof).	95	so it is future-proof).
91		96
92	In addition to being free of having to use I<the one and only true event	97	In addition to being free of having to use I<the one and only true event
93	model>, AnyEvent also is free of bloat and policy: with POE or similar	98	model>, AnyEvent also is free of bloat and policy: with POE or similar
94	modules, you get an enormous amount of code and strict rules you have to	99	modules, you get an enormous amount of code and strict rules you have to
95	follow. AnyEvent, on the other hand, is lean and up to the point, by only	100	follow. AnyEvent, on the other hand, is lean and to the point, by only
96	offering the functionality that is necessary, in as thin as a wrapper as	101	offering the functionality that is necessary, in as thin as a wrapper as
97	technically possible.	102	technically possible.
98		103
99	Of course, AnyEvent comes with a big (and fully optional!) toolbox	104	Of course, AnyEvent comes with a big (and fully optional!) toolbox
100	of useful functionality, such as an asynchronous DNS resolver, 100%	105	of useful functionality, such as an asynchronous DNS resolver, 100%
…		…
106	useful) and you want to force your users to use the one and only event	111	useful) and you want to force your users to use the one and only event
107	model, you should I<not> use this module.	112	model, you should I<not> use this module.
108		113
109	=head1 DESCRIPTION	114	=head1 DESCRIPTION
110		115
111	L<AnyEvent> provides an identical interface to multiple event loops. This	116	L<AnyEvent> provides a uniform interface to various event loops. This
112	allows module authors to utilise an event loop without forcing module	117	allows module authors to use event loop functionality without forcing
113	users to use the same event loop (as only a single event loop can coexist	118	module users to use a specific event loop implementation (since more
114	peacefully at any one time).	119	than one event loop cannot coexist peacefully).
115		120
116	The interface itself is vaguely similar, but not identical to the L<Event>	121	The interface itself is vaguely similar, but not identical to the L<Event>
117	module.	122	module.
118		123
119	During the first call of any watcher-creation method, the module tries	124	During the first call of any watcher-creation method, the module tries
120	to detect the currently loaded event loop by probing whether one of the	125	to detect the currently loaded event loop by probing whether one of the
121	following modules is already loaded: L<EV>,	126	following modules is already loaded: L<EV>, L<AnyEvent::Loop>,
122	L<Event>, L<Glib>, L<AnyEvent::Impl::Perl>, L<Tk>, L<Event::Lib>, L<Qt>,	127	L<Event>, L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>. The first one
123	L<POE>. The first one found is used. If none are found, the module tries	128	found is used. If none are detected, the module tries to load the first
124	to load these modules (excluding Tk, Event::Lib, Qt and POE as the pure perl	129	four modules in the order given; but note that if L<EV> is not
125	adaptor should always succeed) in the order given. The first one that can	130	available, the pure-perl L<AnyEvent::Loop> should always work, so
126	be successfully loaded will be used. If, after this, still none could be	131	the other two are not normally tried.
127	found, AnyEvent will fall back to a pure-perl event loop, which is not
128	very efficient, but should work everywhere.
129		132
130	Because AnyEvent first checks for modules that are already loaded, loading	133	Because AnyEvent first checks for modules that are already loaded, loading
131	an event model explicitly before first using AnyEvent will likely make	134	an event model explicitly before first using AnyEvent will likely make
132	that model the default. For example:	135	that model the default. For example:
133		136
…		…
135	use AnyEvent;	138	use AnyEvent;
136		139
137	# .. AnyEvent will likely default to Tk	140	# .. AnyEvent will likely default to Tk
138		141
139	The I<likely> means that, if any module loads another event model and	142	The I<likely> means that, if any module loads another event model and
140	starts using it, all bets are off. Maybe you should tell their authors to	143	starts using it, all bets are off - this case should be very rare though,
141	use AnyEvent so their modules work together with others seamlessly...	144	as very few modules hardcode event loops without announcing this very
		145	loudly.
142		146
143	The pure-perl implementation of AnyEvent is called	147	The pure-perl implementation of AnyEvent is called C<AnyEvent::Loop>. Like
144	C<AnyEvent::Impl::Perl>. Like other event modules you can load it	148	other event modules you can load it explicitly and enjoy the high
145	explicitly and enjoy the high availability of that event loop :)	149	availability of that event loop :)
146		150
147	=head1 WATCHERS	151	=head1 WATCHERS
148		152
149	AnyEvent has the central concept of a I<watcher>, which is an object that	153	AnyEvent has the central concept of a I<watcher>, which is an object that
150	stores relevant data for each kind of event you are waiting for, such as	154	stores relevant data for each kind of event you are waiting for, such as
…		…
155	callback when the event occurs (of course, only when the event model	159	callback when the event occurs (of course, only when the event model
156	is in control).	160	is in control).
157		161
158	Note that B<callbacks must not permanently change global variables>	162	Note that B<callbacks must not permanently change global variables>
159	potentially in use by the event loop (such as C<$_> or C<$[>) and that B<<	163	potentially in use by the event loop (such as C<$_> or C<$[>) and that B<<
160	callbacks must not C<die> >>. The former is good programming practise in	164	callbacks must not C<die> >>. The former is good programming practice in
161	Perl and the latter stems from the fact that exception handling differs	165	Perl and the latter stems from the fact that exception handling differs
162	widely between event loops.	166	widely between event loops.
163		167
164	To disable the watcher you have to destroy it (e.g. by setting the	168	To disable a watcher you have to destroy it (e.g. by setting the
165	variable you store it in to C<undef> or otherwise deleting all references	169	variable you store it in to C<undef> or otherwise deleting all references
166	to it).	170	to it).
167		171
168	All watchers are created by calling a method on the C<AnyEvent> class.	172	All watchers are created by calling a method on the C<AnyEvent> class.
169		173
170	Many watchers either are used with "recursion" (repeating timers for	174	Many watchers either are used with "recursion" (repeating timers for
171	example), or need to refer to their watcher object in other ways.	175	example), or need to refer to their watcher object in other ways.
172		176
173	An any way to achieve that is this pattern:	177	One way to achieve that is this pattern:
174		178
175	my $w; $w = AnyEvent->type (arg => value ..., cb => sub {	179	my $w; $w = AnyEvent->type (arg => value ..., cb => sub {
176	# you can use $w here, for example to undef it	180	# you can use $w here, for example to undef it
177	undef $w;	181	undef $w;
178	});	182	});
…		…
210		214
211	The I/O watcher might use the underlying file descriptor or a copy of it.	215	The I/O watcher might use the underlying file descriptor or a copy of it.
212	You must not close a file handle as long as any watcher is active on the	216	You must not close a file handle as long as any watcher is active on the
213	underlying file descriptor.	217	underlying file descriptor.
214		218
215	Some event loops issue spurious readyness notifications, so you should	219	Some event loops issue spurious readiness notifications, so you should
216	always use non-blocking calls when reading/writing from/to your file	220	always use non-blocking calls when reading/writing from/to your file
217	handles.	221	handles.
218		222
219	Example: wait for readability of STDIN, then read a line and disable the	223	Example: wait for readability of STDIN, then read a line and disable the
220	watcher.	224	watcher.
…		…
244		248
245	Although the callback might get passed parameters, their value and	249	Although the callback might get passed parameters, their value and
246	presence is undefined and you cannot rely on them. Portable AnyEvent	250	presence is undefined and you cannot rely on them. Portable AnyEvent
247	callbacks cannot use arguments passed to time watcher callbacks.	251	callbacks cannot use arguments passed to time watcher callbacks.
248		252
249	The callback will normally be invoked once only. If you specify another	253	The callback will normally be invoked only once. If you specify another
250	parameter, C<interval>, as a strictly positive number (> 0), then the	254	parameter, C<interval>, as a strictly positive number (> 0), then the
251	callback will be invoked regularly at that interval (in fractional	255	callback will be invoked regularly at that interval (in fractional
252	seconds) after the first invocation. If C<interval> is specified with a	256	seconds) after the first invocation. If C<interval> is specified with a
253	false value, then it is treated as if it were missing.	257	false value, then it is treated as if it were not specified at all.
254		258
255	The callback will be rescheduled before invoking the callback, but no	259	The callback will be rescheduled before invoking the callback, but no
256	attempt is done to avoid timer drift in most backends, so the interval is	260	attempt is made to avoid timer drift in most backends, so the interval is
257	only approximate.	261	only approximate.
258		262
259	Example: fire an event after 7.7 seconds.	263	Example: fire an event after 7.7 seconds.
260		264
261	my $w = AnyEvent->timer (after => 7.7, cb => sub {	265	my $w = AnyEvent->timer (after => 7.7, cb => sub {
…		…
279		283
280	While most event loops expect timers to specified in a relative way, they	284	While most event loops expect timers to specified in a relative way, they
281	use absolute time internally. This makes a difference when your clock	285	use absolute time internally. This makes a difference when your clock
282	"jumps", for example, when ntp decides to set your clock backwards from	286	"jumps", for example, when ntp decides to set your clock backwards from
283	the wrong date of 2014-01-01 to 2008-01-01, a watcher that is supposed to	287	the wrong date of 2014-01-01 to 2008-01-01, a watcher that is supposed to
284	fire "after" a second might actually take six years to finally fire.	288	fire "after a second" might actually take six years to finally fire.
285		289
286	AnyEvent cannot compensate for this. The only event loop that is conscious	290	AnyEvent cannot compensate for this. The only event loop that is conscious
287	about these issues is L<EV>, which offers both relative (ev_timer, based	291	of these issues is L<EV>, which offers both relative (ev_timer, based
288	on true relative time) and absolute (ev_periodic, based on wallclock time)	292	on true relative time) and absolute (ev_periodic, based on wallclock time)
289	timers.	293	timers.
290		294
291	AnyEvent always prefers relative timers, if available, matching the	295	AnyEvent always prefers relative timers, if available, matching the
292	AnyEvent API.	296	AnyEvent API.
…		…
314	I<In almost all cases (in all cases if you don't care), this is the	318	I<In almost all cases (in all cases if you don't care), this is the
315	function to call when you want to know the current time.>	319	function to call when you want to know the current time.>
316		320
317	This function is also often faster then C<< AnyEvent->time >>, and	321	This function is also often faster then C<< AnyEvent->time >>, and
318	thus the preferred method if you want some timestamp (for example,	322	thus the preferred method if you want some timestamp (for example,
319	L<AnyEvent::Handle> uses this to update it's activity timeouts).	323	L<AnyEvent::Handle> uses this to update its activity timeouts).
320		324
321	The rest of this section is only of relevance if you try to be very exact	325	The rest of this section is only of relevance if you try to be very exact
322	with your timing, you can skip it without bad conscience.	326	with your timing; you can skip it without a bad conscience.
323		327
324	For a practical example of when these times differ, consider L<Event::Lib>	328	For a practical example of when these times differ, consider L<Event::Lib>
325	and L<EV> and the following set-up:	329	and L<EV> and the following set-up:
326		330
327	The event loop is running and has just invoked one of your callback at	331	The event loop is running and has just invoked one of your callbacks at
328	time=500 (assume no other callbacks delay processing). In your callback,	332	time=500 (assume no other callbacks delay processing). In your callback,
329	you wait a second by executing C<sleep 1> (blocking the process for a	333	you wait a second by executing C<sleep 1> (blocking the process for a
330	second) and then (at time=501) you create a relative timer that fires	334	second) and then (at time=501) you create a relative timer that fires
331	after three seconds.	335	after three seconds.
332		336
…		…
352	difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into	356	difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into
353	account.	357	account.
354		358
355	=item AnyEvent->now_update	359	=item AnyEvent->now_update
356		360
357	Some event loops (such as L<EV> or L<AnyEvent::Impl::Perl>) cache	361	Some event loops (such as L<EV> or L<AnyEvent::Loop>) cache the current
358	the current time for each loop iteration (see the discussion of L<<	362	time for each loop iteration (see the discussion of L<< AnyEvent->now >>,
359	AnyEvent->now >>, above).	363	above).
360		364
361	When a callback runs for a long time (or when the process sleeps), then	365	When a callback runs for a long time (or when the process sleeps), then
362	this "current" time will differ substantially from the real time, which	366	this "current" time will differ substantially from the real time, which
363	might affect timers and time-outs.	367	might affect timers and time-outs.
364		368
…		…
411	not restart syscalls (that includes L<Async::Interrupt> and AnyEvent's	415	not restart syscalls (that includes L<Async::Interrupt> and AnyEvent's
412	pure perl implementation).	416	pure perl implementation).
413		417
414	=head3 Safe/Unsafe Signals	418	=head3 Safe/Unsafe Signals
415		419
416	Perl signals can be either "safe" (synchronous to opcode handling) or	420	Perl signals can be either "safe" (synchronous to opcode handling)
417	"unsafe" (asynchronous) - the former might get delayed indefinitely, the	421	or "unsafe" (asynchronous) - the former might delay signal delivery
418	latter might corrupt your memory.	422	indefinitely, the latter might corrupt your memory.
419		423
420	AnyEvent signal handlers are, in addition, synchronous to the event loop,	424	AnyEvent signal handlers are, in addition, synchronous to the event loop,
421	i.e. they will not interrupt your running perl program but will only be	425	i.e. they will not interrupt your running perl program but will only be
422	called as part of the normal event handling (just like timer, I/O etc.	426	called as part of the normal event handling (just like timer, I/O etc.
423	callbacks, too).	427	callbacks, too).
424		428
425	=head3 Signal Races, Delays and Workarounds	429	=head3 Signal Races, Delays and Workarounds
426		430
427	Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support attaching	431	Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support
428	callbacks to signals in a generic way, which is a pity, as you cannot	432	attaching callbacks to signals in a generic way, which is a pity,
429	do race-free signal handling in perl, requiring C libraries for	433	as you cannot do race-free signal handling in perl, requiring
430	this. AnyEvent will try to do it's best, which means in some cases,	434	C libraries for this. AnyEvent will try to do its best, which
431	signals will be delayed. The maximum time a signal might be delayed is	435	means in some cases, signals will be delayed. The maximum time
432	specified in C<$AnyEvent::MAX_SIGNAL_LATENCY> (default: 10 seconds). This	436	a signal might be delayed is 10 seconds by default, but can
433	variable can be changed only before the first signal watcher is created,	437	be overriden via C<$ENV{PERL_ANYEVENT_MAX_SIGNAL_LATENCY}> or
434	and should be left alone otherwise. This variable determines how often	438	C<$AnyEvent::MAX_SIGNAL_LATENCY> - see the Ö<ENVIRONMENT VARIABLES>
435	AnyEvent polls for signals (in case a wake-up was missed). Higher values	439	section for details.
436	will cause fewer spurious wake-ups, which is better for power and CPU
437	saving.
438		440
439	All these problems can be avoided by installing the optional	441	All these problems can be avoided by installing the optional
440	L<Async::Interrupt> module, which works with most event loops. It will not	442	L<Async::Interrupt> module, which works with most event loops. It will not
441	work with inherently broken event loops such as L<Event> or L<Event::Lib>	443	work with inherently broken event loops such as L<Event> or L<Event::Lib>
442	(and not with L<POE> currently, as POE does it's own workaround with	444	(and not with L<POE> currently). For those, you just have to suffer the
443	one-second latency). For those, you just have to suffer the delays.	445	delays.
444		446
445	=head2 CHILD PROCESS WATCHERS	447	=head2 CHILD PROCESS WATCHERS
446		448
447	$w = AnyEvent->child (pid => <process id>, cb => <callback>);	449	$w = AnyEvent->child (pid => <process id>, cb => <callback>);
448		450
449	You can also watch on a child process exit and catch its exit status.	451	You can also watch for a child process exit and catch its exit status.
450		452
451	The child process is specified by the C<pid> argument (one some backends,	453	The child process is specified by the C<pid> argument (on some backends,
452	using C<0> watches for any child process exit, on others this will	454	using C<0> watches for any child process exit, on others this will
453	croak). The watcher will be triggered only when the child process has	455	croak). The watcher will be triggered only when the child process has
454	finished and an exit status is available, not on any trace events	456	finished and an exit status is available, not on any trace events
455	(stopped/continued).	457	(stopped/continued).
456		458
…		…
478	thing in an AnyEvent program, you I<have> to create at least one	480	thing in an AnyEvent program, you I<have> to create at least one
479	watcher before you C<fork> the child (alternatively, you can call	481	watcher before you C<fork> the child (alternatively, you can call
480	C<AnyEvent::detect>).	482	C<AnyEvent::detect>).
481		483
482	As most event loops do not support waiting for child events, they will be	484	As most event loops do not support waiting for child events, they will be
483	emulated by AnyEvent in most cases, in which the latency and race problems	485	emulated by AnyEvent in most cases, in which case the latency and race
484	mentioned in the description of signal watchers apply.	486	problems mentioned in the description of signal watchers apply.
485		487
486	Example: fork a process and wait for it	488	Example: fork a process and wait for it
487		489
488	my $done = AnyEvent->condvar;	490	my $done = AnyEvent->condvar;
489		491
…		…
503		505
504	=head2 IDLE WATCHERS	506	=head2 IDLE WATCHERS
505		507
506	$w = AnyEvent->idle (cb => <callback>);	508	$w = AnyEvent->idle (cb => <callback>);
507		509
508	Repeatedly invoke the callback after the process becomes idle, until	510	This will repeatedly invoke the callback after the process becomes idle,
509	either the watcher is destroyed or new events have been detected.	511	until either the watcher is destroyed or new events have been detected.
510		512
511	Idle watchers are useful when there is a need to do something, but it	513	Idle watchers are useful when there is a need to do something, but it
512	is not so important (or wise) to do it instantly. The callback will be	514	is not so important (or wise) to do it instantly. The callback will be
513	invoked only when there is "nothing better to do", which is usually	515	invoked only when there is "nothing better to do", which is usually
514	defined as "all outstanding events have been handled and no new events	516	defined as "all outstanding events have been handled and no new events
…		…
553	will actively watch for new events and call your callbacks.	555	will actively watch for new events and call your callbacks.
554		556
555	AnyEvent is slightly different: it expects somebody else to run the event	557	AnyEvent is slightly different: it expects somebody else to run the event
556	loop and will only block when necessary (usually when told by the user).	558	loop and will only block when necessary (usually when told by the user).
557		559
558	The instrument to do that is called a "condition variable", so called	560	The tool to do that is called a "condition variable", so called because
559	because they represent a condition that must become true.	561	they represent a condition that must become true.
560		562
561	Now is probably a good time to look at the examples further below.	563	Now is probably a good time to look at the examples further below.
562		564
563	Condition variables can be created by calling the C<< AnyEvent->condvar	565	Condition variables can be created by calling the C<< AnyEvent->condvar
564	>> method, usually without arguments. The only argument pair allowed is	566	>> method, usually without arguments. The only argument pair allowed is
…		…
569	After creation, the condition variable is "false" until it becomes "true"	571	After creation, the condition variable is "false" until it becomes "true"
570	by calling the C<send> method (or calling the condition variable as if it	572	by calling the C<send> method (or calling the condition variable as if it
571	were a callback, read about the caveats in the description for the C<<	573	were a callback, read about the caveats in the description for the C<<
572	->send >> method).	574	->send >> method).
573		575
574	Condition variables are similar to callbacks, except that you can	576	Since condition variables are the most complex part of the AnyEvent API, here are
575	optionally wait for them. They can also be called merge points - points	577	some different mental models of what they are - pick the ones you can connect to:
576	in time where multiple outstanding events have been processed. And yet	578
577	another way to call them is transactions - each condition variable can be	579	=over 4
578	used to represent a transaction, which finishes at some point and delivers	580
579	a result. And yet some people know them as "futures" - a promise to	581	=item * Condition variables are like callbacks - you can call them (and pass them instead
580	compute/deliver something that you can wait for.	582	of callbacks). Unlike callbacks however, you can also wait for them to be called.
		583
		584	=item * Condition variables are signals - one side can emit or send them,
		585	the other side can wait for them, or install a handler that is called when
		586	the signal fires.
		587
		588	=item * Condition variables are like "Merge Points" - points in your program
		589	where you merge multiple independent results/control flows into one.
		590
		591	=item * Condition variables represent a transaction - functions that start
		592	some kind of transaction can return them, leaving the caller the choice
		593	between waiting in a blocking fashion, or setting a callback.
		594
		595	=item * Condition variables represent future values, or promises to deliver
		596	some result, long before the result is available.
		597
		598	=back
581		599
582	Condition variables are very useful to signal that something has finished,	600	Condition variables are very useful to signal that something has finished,
583	for example, if you write a module that does asynchronous http requests,	601	for example, if you write a module that does asynchronous http requests,
584	then a condition variable would be the ideal candidate to signal the	602	then a condition variable would be the ideal candidate to signal the
585	availability of results. The user can either act when the callback is	603	availability of results. The user can either act when the callback is
…		…
598		616
599	Condition variables are represented by hash refs in perl, and the keys	617	Condition variables are represented by hash refs in perl, and the keys
600	used by AnyEvent itself are all named C<_ae_XXX> to make subclassing	618	used by AnyEvent itself are all named C<_ae_XXX> to make subclassing
601	easy (it is often useful to build your own transaction class on top of	619	easy (it is often useful to build your own transaction class on top of
602	AnyEvent). To subclass, use C<AnyEvent::CondVar> as base class and call	620	AnyEvent). To subclass, use C<AnyEvent::CondVar> as base class and call
603	it's C<new> method in your own C<new> method.	621	its C<new> method in your own C<new> method.
604		622
605	There are two "sides" to a condition variable - the "producer side" which	623	There are two "sides" to a condition variable - the "producer side" which
606	eventually calls C<< -> send >>, and the "consumer side", which waits	624	eventually calls C<< -> send >>, and the "consumer side", which waits
607	for the send to occur.	625	for the send to occur.
608		626
609	Example: wait for a timer.	627	Example: wait for a timer.
610		628
611	# wait till the result is ready	629	# condition: "wait till the timer is fired"
612	my $result_ready = AnyEvent->condvar;	630	my $timer_fired = AnyEvent->condvar;
613		631
614	# do something such as adding a timer	632	# create the timer - we could wait for, say
615	# or socket watcher the calls $result_ready->send	633	# a handle becomign ready, or even an
616	# when the "result" is ready.	634	# AnyEvent::HTTP request to finish, but
617	# in this case, we simply use a timer:	635	# in this case, we simply use a timer:
618	my $w = AnyEvent->timer (	636	my $w = AnyEvent->timer (
619	after => 1,	637	after => 1,
620	cb => sub { $result_ready->send },	638	cb => sub { $timer_fired->send },
621	);	639	);
622		640
623	# this "blocks" (while handling events) till the callback	641	# this "blocks" (while handling events) till the callback
624	# calls ->send	642	# calls ->send
625	$result_ready->recv;	643	$timer_fired->recv;
626		644
627	Example: wait for a timer, but take advantage of the fact that condition	645	Example: wait for a timer, but take advantage of the fact that condition
628	variables are also callable directly.	646	variables are also callable directly.
629		647
630	my $done = AnyEvent->condvar;	648	my $done = AnyEvent->condvar;
…		…
673	they were a code reference). Calling them directly is the same as calling	691	they were a code reference). Calling them directly is the same as calling
674	C<send>.	692	C<send>.
675		693
676	=item $cv->croak ($error)	694	=item $cv->croak ($error)
677		695
678	Similar to send, but causes all call's to C<< ->recv >> to invoke	696	Similar to send, but causes all calls to C<< ->recv >> to invoke
679	C<Carp::croak> with the given error message/object/scalar.	697	C<Carp::croak> with the given error message/object/scalar.
680		698
681	This can be used to signal any errors to the condition variable	699	This can be used to signal any errors to the condition variable
682	user/consumer. Doing it this way instead of calling C<croak> directly	700	user/consumer. Doing it this way instead of calling C<croak> directly
683	delays the error detetcion, but has the overwhelmign advantage that it	701	delays the error detection, but has the overwhelming advantage that it
684	diagnoses the error at the place where the result is expected, and not	702	diagnoses the error at the place where the result is expected, and not
685	deep in some event clalback without connection to the actual code causing	703	deep in some event callback with no connection to the actual code causing
686	the problem.	704	the problem.
687		705
688	=item $cv->begin ([group callback])	706	=item $cv->begin ([group callback])
689		707
690	=item $cv->end	708	=item $cv->end
…		…
728	one call to C<begin>, so the condvar waits for all calls to C<end> before	746	one call to C<begin>, so the condvar waits for all calls to C<end> before
729	sending.	747	sending.
730		748
731	The ping example mentioned above is slightly more complicated, as the	749	The ping example mentioned above is slightly more complicated, as the
732	there are results to be passwd back, and the number of tasks that are	750	there are results to be passwd back, and the number of tasks that are
733	begung can potentially be zero:	751	begun can potentially be zero:
734		752
735	my $cv = AnyEvent->condvar;	753	my $cv = AnyEvent->condvar;
736		754
737	my %result;	755	my %result;
738	$cv->begin (sub { shift->send (\%result) });	756	$cv->begin (sub { shift->send (\%result) });
…		…
759	to be called once the counter reaches C<0>, and second, it ensures that	777	to be called once the counter reaches C<0>, and second, it ensures that
760	C<send> is called even when C<no> hosts are being pinged (the loop	778	C<send> is called even when C<no> hosts are being pinged (the loop
761	doesn't execute once).	779	doesn't execute once).
762		780
763	This is the general pattern when you "fan out" into multiple (but	781	This is the general pattern when you "fan out" into multiple (but
764	potentially none) subrequests: use an outer C<begin>/C<end> pair to set	782	potentially zero) subrequests: use an outer C<begin>/C<end> pair to set
765	the callback and ensure C<end> is called at least once, and then, for each	783	the callback and ensure C<end> is called at least once, and then, for each
766	subrequest you start, call C<begin> and for each subrequest you finish,	784	subrequest you start, call C<begin> and for each subrequest you finish,
767	call C<end>.	785	call C<end>.
768		786
769	=back	787	=back
…		…
776	=over 4	794	=over 4
777		795
778	=item $cv->recv	796	=item $cv->recv
779		797
780	Wait (blocking if necessary) until the C<< ->send >> or C<< ->croak	798	Wait (blocking if necessary) until the C<< ->send >> or C<< ->croak
781	>> methods have been called on c<$cv>, while servicing other watchers	799	>> methods have been called on C<$cv>, while servicing other watchers
782	normally.	800	normally.
783		801
784	You can only wait once on a condition - additional calls are valid but	802	You can only wait once on a condition - additional calls are valid but
785	will return immediately.	803	will return immediately.
786		804
…		…
803	caller decide whether the call will block or not (for example, by coupling	821	caller decide whether the call will block or not (for example, by coupling
804	condition variables with some kind of request results and supporting	822	condition variables with some kind of request results and supporting
805	callbacks so the caller knows that getting the result will not block,	823	callbacks so the caller knows that getting the result will not block,
806	while still supporting blocking waits if the caller so desires).	824	while still supporting blocking waits if the caller so desires).
807		825
808	You can ensure that C<< -recv >> never blocks by setting a callback and	826	You can ensure that C<< ->recv >> never blocks by setting a callback and
809	only calling C<< ->recv >> from within that callback (or at a later	827	only calling C<< ->recv >> from within that callback (or at a later
810	time). This will work even when the event loop does not support blocking	828	time). This will work even when the event loop does not support blocking
811	waits otherwise.	829	waits otherwise.
812		830
813	=item $bool = $cv->ready	831	=item $bool = $cv->ready
…		…
818	=item $cb = $cv->cb ($cb->($cv))	836	=item $cb = $cv->cb ($cb->($cv))
819		837
820	This is a mutator function that returns the callback set and optionally	838	This is a mutator function that returns the callback set and optionally
821	replaces it before doing so.	839	replaces it before doing so.
822		840
823	The callback will be called when the condition becomes (or already was)	841	The callback will be called when the condition becomes "true", i.e. when
824	"true", i.e. when C<send> or C<croak> are called (or were called), with	842	C<send> or C<croak> are called, with the only argument being the
825	the only argument being the condition variable itself. Calling C<recv>	843	condition variable itself. If the condition is already true, the
		844	callback is called immediately when it is set. Calling C<recv> inside
826	inside the callback or at any later time is guaranteed not to block.	845	the callback or at any later time is guaranteed not to block.
827		846
828	=back	847	=back
829		848
830	=head1 SUPPORTED EVENT LOOPS/BACKENDS	849	=head1 SUPPORTED EVENT LOOPS/BACKENDS
831		850
…		…
839	use. If EV is not installed, then AnyEvent will fall back to its own	858	use. If EV is not installed, then AnyEvent will fall back to its own
840	pure-perl implementation, which is available everywhere as it comes with	859	pure-perl implementation, which is available everywhere as it comes with
841	AnyEvent itself.	860	AnyEvent itself.
842		861
843	AnyEvent::Impl::EV based on EV (interface to libev, best choice).	862	AnyEvent::Impl::EV based on EV (interface to libev, best choice).
844	AnyEvent::Impl::Perl pure-perl implementation, fast and portable.	863	AnyEvent::Impl::Perl pure-perl AnyEvent::Loop, fast and portable.
845		864
846	=item Backends that are transparently being picked up when they are used.	865	=item Backends that are transparently being picked up when they are used.
847		866
848	These will be used when they are currently loaded when the first watcher	867	These will be used if they are already loaded when the first watcher
849	is created, in which case it is assumed that the application is using	868	is created, in which case it is assumed that the application is using
850	them. This means that AnyEvent will automatically pick the right backend	869	them. This means that AnyEvent will automatically pick the right backend
851	when the main program loads an event module before anything starts to	870	when the main program loads an event module before anything starts to
852	create watchers. Nothing special needs to be done by the main program.	871	create watchers. Nothing special needs to be done by the main program.
853		872
…		…
855	AnyEvent::Impl::Glib based on Glib, slow but very stable.	874	AnyEvent::Impl::Glib based on Glib, slow but very stable.
856	AnyEvent::Impl::Tk based on Tk, very broken.	875	AnyEvent::Impl::Tk based on Tk, very broken.
857	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.	876	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
858	AnyEvent::Impl::POE based on POE, very slow, some limitations.	877	AnyEvent::Impl::POE based on POE, very slow, some limitations.
859	AnyEvent::Impl::Irssi used when running within irssi.	878	AnyEvent::Impl::Irssi used when running within irssi.
		879	AnyEvent::Impl::IOAsync based on IO::Async.
		880	AnyEvent::Impl::Cocoa based on Cocoa::EventLoop.
		881	AnyEvent::Impl::FLTK based on FLTK (fltk 2 binding).
860		882
861	=item Backends with special needs.	883	=item Backends with special needs.
862		884
863	Qt requires the Qt::Application to be instantiated first, but will	885	Qt requires the Qt::Application to be instantiated first, but will
864	otherwise be picked up automatically. As long as the main program	886	otherwise be picked up automatically. As long as the main program
865	instantiates the application before any AnyEvent watchers are created,	887	instantiates the application before any AnyEvent watchers are created,
866	everything should just work.	888	everything should just work.
867		889
868	AnyEvent::Impl::Qt based on Qt.	890	AnyEvent::Impl::Qt based on Qt.
869		891
870	Support for IO::Async can only be partial, as it is too broken and
871	architecturally limited to even support the AnyEvent API. It also
872	is the only event loop that needs the loop to be set explicitly, so
873	it can only be used by a main program knowing about AnyEvent. See
874	L<AnyEvent::Impl::Async> for the gory details.
875
876	AnyEvent::Impl::IOAsync based on IO::Async, cannot be autoprobed.
877
878	=item Event loops that are indirectly supported via other backends.	892	=item Event loops that are indirectly supported via other backends.
879		893
880	Some event loops can be supported via other modules:	894	Some event loops can be supported via other modules:
881		895
882	There is no direct support for WxWidgets (L<Wx>) or L<Prima>.	896	There is no direct support for WxWidgets (L<Wx>) or L<Prima>.
…		…
907	Contains C<undef> until the first watcher is being created, before the	921	Contains C<undef> until the first watcher is being created, before the
908	backend has been autodetected.	922	backend has been autodetected.
909		923
910	Afterwards it contains the event model that is being used, which is the	924	Afterwards it contains the event model that is being used, which is the
911	name of the Perl class implementing the model. This class is usually one	925	name of the Perl class implementing the model. This class is usually one
912	of the C<AnyEvent::Impl:xxx> modules, but can be any other class in the	926	of the C<AnyEvent::Impl::xxx> modules, but can be any other class in the
913	case AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode> it	927	case AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode> it
914	will be C<urxvt::anyevent>).	928	will be C<urxvt::anyevent>).
915		929
916	=item AnyEvent::detect	930	=item AnyEvent::detect
917		931
918	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model	932	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model
919	if necessary. You should only call this function right before you would	933	if necessary. You should only call this function right before you would
920	have created an AnyEvent watcher anyway, that is, as late as possible at	934	have created an AnyEvent watcher anyway, that is, as late as possible at
921	runtime, and not e.g. while initialising of your module.	935	runtime, and not e.g. during initialisation of your module.
		936
		937	The effect of calling this function is as if a watcher had been created
		938	(specifically, actions that happen "when the first watcher is created"
		939	happen when calling detetc as well).
922		940
923	If you need to do some initialisation before AnyEvent watchers are	941	If you need to do some initialisation before AnyEvent watchers are
924	created, use C<post_detect>.	942	created, use C<post_detect>.
925		943
926	=item $guard = AnyEvent::post_detect { BLOCK }	944	=item $guard = AnyEvent::post_detect { BLOCK }
927		945
928	Arranges for the code block to be executed as soon as the event model is	946	Arranges for the code block to be executed as soon as the event model is
929	autodetected (or immediately if this has already happened).	947	autodetected (or immediately if that has already happened).
930		948
931	The block will be executed I<after> the actual backend has been detected	949	The block will be executed I<after> the actual backend has been detected
932	(C<$AnyEvent::MODEL> is set), but I<before> any watchers have been	950	(C<$AnyEvent::MODEL> is set), but I<before> any watchers have been
933	created, so it is possible to e.g. patch C<@AnyEvent::ISA> or do	951	created, so it is possible to e.g. patch C<@AnyEvent::ISA> or do
934	other initialisations - see the sources of L<AnyEvent::Strict> or	952	other initialisations - see the sources of L<AnyEvent::Strict> or
…		…
943	that automatically removes the callback again when it is destroyed (or	961	that automatically removes the callback again when it is destroyed (or
944	C<undef> when the hook was immediately executed). See L<AnyEvent::AIO> for	962	C<undef> when the hook was immediately executed). See L<AnyEvent::AIO> for
945	a case where this is useful.	963	a case where this is useful.
946		964
947	Example: Create a watcher for the IO::AIO module and store it in	965	Example: Create a watcher for the IO::AIO module and store it in
948	C<$WATCHER>. Only do so after the event loop is initialised, though.	966	C<$WATCHER>, but do so only do so after the event loop is initialised.
949		967
950	our WATCHER;	968	our WATCHER;
951		969
952	my $guard = AnyEvent::post_detect {	970	my $guard = AnyEvent::post_detect {
953	$WATCHER = AnyEvent->io (fh => IO::AIO::poll_fileno, poll => 'r', cb => \&IO::AIO::poll_cb);	971	$WATCHER = AnyEvent->io (fh => IO::AIO::poll_fileno, poll => 'r', cb => \&IO::AIO::poll_cb);
…		…
961	$WATCHER ||= $guard;	979	$WATCHER ||= $guard;
962		980
963	=item @AnyEvent::post_detect	981	=item @AnyEvent::post_detect
964		982
965	If there are any code references in this array (you can C<push> to it	983	If there are any code references in this array (you can C<push> to it
966	before or after loading AnyEvent), then they will called directly after	984	before or after loading AnyEvent), then they will be called directly
967	the event loop has been chosen.	985	after the event loop has been chosen.
968		986
969	You should check C<$AnyEvent::MODEL> before adding to this array, though:	987	You should check C<$AnyEvent::MODEL> before adding to this array, though:
970	if it is defined then the event loop has already been detected, and the	988	if it is defined then the event loop has already been detected, and the
971	array will be ignored.	989	array will be ignored.
972		990
…		…
989	# AnyEvent not yet initialised, so make sure to load Coro::AnyEvent	1007	# AnyEvent not yet initialised, so make sure to load Coro::AnyEvent
990	# as soon as it is	1008	# as soon as it is
991	push @AnyEvent::post_detect, sub { require Coro::AnyEvent };	1009	push @AnyEvent::post_detect, sub { require Coro::AnyEvent };
992	}	1010	}
993		1011
		1012	=item AnyEvent::postpone { BLOCK }
		1013
		1014	Arranges for the block to be executed as soon as possible, but not before
		1015	the call itself returns. In practise, the block will be executed just
		1016	before the event loop polls for new events, or shortly afterwards.
		1017
		1018	This function never returns anything (to make the C<return postpone { ...
		1019	}> idiom more useful.
		1020
		1021	To understand the usefulness of this function, consider a function that
		1022	asynchronously does something for you and returns some transaction
		1023	object or guard to let you cancel the operation. For example,
		1024	C<AnyEvent::Socket::tcp_connect>:
		1025
		1026	# start a conenction attempt unless one is active
		1027	$self->{connect_guard} ||= AnyEvent::Socket::tcp_connect "www.example.net", 80, sub {
		1028	delete $self->{connect_guard};
		1029	...
		1030	};
		1031
		1032	Imagine that this function could instantly call the callback, for
		1033	example, because it detects an obvious error such as a negative port
		1034	number. Invoking the callback before the function returns causes problems
		1035	however: the callback will be called and will try to delete the guard
		1036	object. But since the function hasn't returned yet, there is nothing to
		1037	delete. When the function eventually returns it will assign the guard
		1038	object to C<< $self->{connect_guard} >>, where it will likely never be
		1039	deleted, so the program thinks it is still trying to connect.
		1040
		1041	This is where C<AnyEvent::postpone> should be used. Instead of calling the
		1042	callback directly on error:
		1043
		1044	$cb->(undef), return # signal error to callback, BAD!
		1045	if $some_error_condition;
		1046
		1047	It should use C<postpone>:
		1048
		1049	AnyEvent::postpone { $cb->(undef) }, return # signal error to callback, later
		1050	if $some_error_condition;
		1051
		1052	=item AnyEvent::log $level, $msg[, @args]
		1053
		1054	Log the given C<$msg> at the given C<$level>.
		1055
		1056	If L<AnyEvent::Log> is not loaded then this function makes a simple test
		1057	to see whether the message will be logged. If the test succeeds it will
		1058	load AnyEvent::Log and call C<AnyEvent::Log::log> - consequently, look at
		1059	the L<AnyEvent::Log> documentation for details.
		1060
		1061	If the test fails it will simply return. Right now this happens when a
		1062	numerical loglevel is used and it is larger than the level specified via
		1063	C<$ENV{PERL_ANYEVENT_VERBOSE}>.
		1064
		1065	If you want to sprinkle loads of logging calls around your code, consider
		1066	creating a logger callback with the C<AnyEvent::Log::logger> function,
		1067	which can reduce typing, codesize and can reduce the logging overhead
		1068	enourmously.
		1069
994	=back	1070	=back
995		1071
996	=head1 WHAT TO DO IN A MODULE	1072	=head1 WHAT TO DO IN A MODULE
997		1073
998	As a module author, you should C<use AnyEvent> and call AnyEvent methods	1074	As a module author, you should C<use AnyEvent> and call AnyEvent methods
…		…
1008	because it will stall the whole program, and the whole point of using	1084	because it will stall the whole program, and the whole point of using
1009	events is to stay interactive.	1085	events is to stay interactive.
1010		1086
1011	It is fine, however, to call C<< ->recv >> when the user of your module	1087	It is fine, however, to call C<< ->recv >> when the user of your module
1012	requests it (i.e. if you create a http request object ad have a method	1088	requests it (i.e. if you create a http request object ad have a method
1013	called C<results> that returns the results, it should call C<< ->recv >>	1089	called C<results> that returns the results, it may call C<< ->recv >>
1014	freely, as the user of your module knows what she is doing. always).	1090	freely, as the user of your module knows what she is doing. Always).
1015		1091
1016	=head1 WHAT TO DO IN THE MAIN PROGRAM	1092	=head1 WHAT TO DO IN THE MAIN PROGRAM
1017		1093
1018	There will always be a single main program - the only place that should	1094	There will always be a single main program - the only place that should
1019	dictate which event model to use.	1095	dictate which event model to use.
1020		1096
1021	If it doesn't care, it can just "use AnyEvent" and use it itself, or not	1097	If the program is not event-based, it need not do anything special, even
1022	do anything special (it does not need to be event-based) and let AnyEvent	1098	when it depends on a module that uses an AnyEvent. If the program itself
1023	decide which implementation to chose if some module relies on it.	1099	uses AnyEvent, but does not care which event loop is used, all it needs
		1100	to do is C<use AnyEvent>. In either case, AnyEvent will choose the best
		1101	available loop implementation.
1024		1102
1025	If the main program relies on a specific event model - for example, in	1103	If the main program relies on a specific event model - for example, in
1026	Gtk2 programs you have to rely on the Glib module - you should load the	1104	Gtk2 programs you have to rely on the Glib module - you should load the
1027	event module before loading AnyEvent or any module that uses it: generally	1105	event module before loading AnyEvent or any module that uses it: generally
1028	speaking, you should load it as early as possible. The reason is that	1106	speaking, you should load it as early as possible. The reason is that
1029	modules might create watchers when they are loaded, and AnyEvent will	1107	modules might create watchers when they are loaded, and AnyEvent will
1030	decide on the event model to use as soon as it creates watchers, and it	1108	decide on the event model to use as soon as it creates watchers, and it
1031	might chose the wrong one unless you load the correct one yourself.	1109	might choose the wrong one unless you load the correct one yourself.
1032		1110
1033	You can chose to use a pure-perl implementation by loading the	1111	You can chose to use a pure-perl implementation by loading the
1034	C<AnyEvent::Impl::Perl> module, which gives you similar behaviour	1112	C<AnyEvent::Loop> module, which gives you similar behaviour
1035	everywhere, but letting AnyEvent chose the model is generally better.	1113	everywhere, but letting AnyEvent chose the model is generally better.
1036		1114
1037	=head2 MAINLOOP EMULATION	1115	=head2 MAINLOOP EMULATION
1038		1116
1039	Sometimes (often for short test scripts, or even standalone programs who	1117	Sometimes (often for short test scripts, or even standalone programs who
…		…
1052		1130
1053		1131
1054	=head1 OTHER MODULES	1132	=head1 OTHER MODULES
1055		1133
1056	The following is a non-exhaustive list of additional modules that use	1134	The following is a non-exhaustive list of additional modules that use
1057	AnyEvent as a client and can therefore be mixed easily with other AnyEvent	1135	AnyEvent as a client and can therefore be mixed easily with other
1058	modules and other event loops in the same program. Some of the modules	1136	AnyEvent modules and other event loops in the same program. Some of the
1059	come with AnyEvent, most are available via CPAN.	1137	modules come as part of AnyEvent, the others are available via CPAN (see
		1138	L<http://search.cpan.org/search?m=module&q=anyevent%3A%3A*> for
		1139	a longer non-exhaustive list), and the list is heavily biased towards
		1140	modules of the AnyEvent author himself :)
1060		1141
1061	=over 4	1142	=over 4
1062		1143
1063	=item L<AnyEvent::Util>	1144	=item L<AnyEvent::Util>
1064		1145
1065	Contains various utility functions that replace often-used but blocking	1146	Contains various utility functions that replace often-used blocking
1066	functions such as C<inet_aton> by event-/callback-based versions.	1147	functions such as C<inet_aton> with event/callback-based versions.
1067		1148
1068	=item L<AnyEvent::Socket>	1149	=item L<AnyEvent::Socket>
1069		1150
1070	Provides various utility functions for (internet protocol) sockets,	1151	Provides various utility functions for (internet protocol) sockets,
1071	addresses and name resolution. Also functions to create non-blocking tcp	1152	addresses and name resolution. Also functions to create non-blocking tcp
…		…
1073		1154
1074	=item L<AnyEvent::Handle>	1155	=item L<AnyEvent::Handle>
1075		1156
1076	Provide read and write buffers, manages watchers for reads and writes,	1157	Provide read and write buffers, manages watchers for reads and writes,
1077	supports raw and formatted I/O, I/O queued and fully transparent and	1158	supports raw and formatted I/O, I/O queued and fully transparent and
1078	non-blocking SSL/TLS (via L<AnyEvent::TLS>.	1159	non-blocking SSL/TLS (via L<AnyEvent::TLS>).
1079		1160
1080	=item L<AnyEvent::DNS>	1161	=item L<AnyEvent::DNS>
1081		1162
1082	Provides rich asynchronous DNS resolver capabilities.	1163	Provides rich asynchronous DNS resolver capabilities.
1083		1164
		1165	=item L<AnyEvent::HTTP>, L<AnyEvent::IRC>, L<AnyEvent::XMPP>, L<AnyEvent::GPSD>, L<AnyEvent::IGS>, L<AnyEvent::FCP>
		1166
		1167	Implement event-based interfaces to the protocols of the same name (for
		1168	the curious, IGS is the International Go Server and FCP is the Freenet
		1169	Client Protocol).
		1170
1084	=item L<AnyEvent::HTTP>	1171	=item L<AnyEvent::AIO>
1085		1172
1086	A simple-to-use HTTP library that is capable of making a lot of concurrent	1173	Truly asynchronous (as opposed to non-blocking) I/O, should be in the
1087	HTTP requests.	1174	toolbox of every event programmer. AnyEvent::AIO transparently fuses
		1175	L<IO::AIO> and AnyEvent together, giving AnyEvent access to event-based
		1176	file I/O, and much more.
		1177
		1178	=item L<AnyEvent::Filesys::Notify>
		1179
		1180	AnyEvent is good for non-blocking stuff, but it can't detect file or
		1181	path changes (e.g. "watch this directory for new files", "watch this
		1182	file for changes"). The L<AnyEvent::Filesys::Notify> module promises to
		1183	do just that in a portbale fashion, supporting inotify on GNU/Linux and
		1184	some weird, without doubt broken, stuff on OS X to monitor files. It can
		1185	fall back to blocking scans at regular intervals transparently on other
		1186	platforms, so it's about as portable as it gets.
		1187
		1188	(I haven't used it myself, but I haven't heard anybody complaining about
		1189	it yet).
		1190
		1191	=item L<AnyEvent::DBI>
		1192
		1193	Executes L<DBI> requests asynchronously in a proxy process for you,
		1194	notifying you in an event-based way when the operation is finished.
1088		1195
1089	=item L<AnyEvent::HTTPD>	1196	=item L<AnyEvent::HTTPD>
1090		1197
1091	Provides a simple web application server framework.	1198	A simple embedded webserver.
1092		1199
1093	=item L<AnyEvent::FastPing>	1200	=item L<AnyEvent::FastPing>
1094		1201
1095	The fastest ping in the west.	1202	The fastest ping in the west.
1096		1203
1097	=item L<AnyEvent::DBI>
1098
1099	Executes L<DBI> requests asynchronously in a proxy process.
1100
1101	=item L<AnyEvent::AIO>
1102
1103	Truly asynchronous I/O, should be in the toolbox of every event
1104	programmer. AnyEvent::AIO transparently fuses L<IO::AIO> and AnyEvent
1105	together.
1106
1107	=item L<AnyEvent::BDB>
1108
1109	Truly asynchronous Berkeley DB access. AnyEvent::BDB transparently fuses
1110	L<BDB> and AnyEvent together.
1111
1112	=item L<AnyEvent::GPSD>
1113
1114	A non-blocking interface to gpsd, a daemon delivering GPS information.
1115
1116	=item L<AnyEvent::IRC>
1117
1118	AnyEvent based IRC client module family (replacing the older Net::IRC3).
1119
1120	=item L<AnyEvent::XMPP>
1121
1122	AnyEvent based XMPP (Jabber protocol) module family (replacing the older
1123	Net::XMPP2>.
1124
1125	=item L<AnyEvent::IGS>
1126
1127	A non-blocking interface to the Internet Go Server protocol (used by
1128	L<App::IGS>).
1129
1130	=item L<Net::FCP>
1131
1132	AnyEvent-based implementation of the Freenet Client Protocol, birthplace
1133	of AnyEvent.
1134
1135	=item L<Event::ExecFlow>
1136
1137	High level API for event-based execution flow control.
1138
1139	=item L<Coro>	1204	=item L<Coro>
1140		1205
1141	Has special support for AnyEvent via L<Coro::AnyEvent>.	1206	Has special support for AnyEvent via L<Coro::AnyEvent>, which allows you
		1207	to simply invert the flow control - don't call us, we will call you:
		1208
		1209	async {
		1210	Coro::AnyEvent::sleep 5; # creates a 5s timer and waits for it
		1211	print "5 seconds later!\n";
		1212
		1213	Coro::AnyEvent::readable *STDIN; # uses an I/O watcher
		1214	my $line = <STDIN>; # works for ttys
		1215
		1216	AnyEvent::HTTP::http_get "url", Coro::rouse_cb;
		1217	my ($body, $hdr) = Coro::rouse_wait;
		1218	};
1142		1219
1143	=back	1220	=back
1144		1221
1145	=cut	1222	=cut
1146		1223
1147	package AnyEvent;	1224	package AnyEvent;
1148		1225
1149	# basically a tuned-down version of common::sense	1226	# basically a tuned-down version of common::sense
1150	sub common_sense {	1227	sub common_sense {
1151	# from common:.sense 1.0	1228	# from common:.sense 3.4
1152	${^WARNING_BITS} = "\xfc\x3f\x33\x00\x0f\xf3\xcf\xc0\xf3\xfc\x33\x00";	1229	${^WARNING_BITS} ^= ${^WARNING_BITS} ^ "\x3c\x3f\x33\x00\x0f\xf0\x0f\xc0\xf0\xfc\x33\x00";
1153	# use strict vars subs - NO UTF-8, as Util.pm doesn't like this atm. (uts46data.pl)	1230	# use strict vars subs - NO UTF-8, as Util.pm doesn't like this atm. (uts46data.pl)
1154	$^H |= 0x00000600;	1231	$^H |= 0x00000600;
1155	}	1232	}
1156		1233
1157	BEGIN { AnyEvent::common_sense }	1234	BEGIN { AnyEvent::common_sense }
1158		1235
1159	use Carp ();	1236	use Carp ();
1160		1237
1161	our $VERSION = '5.24';	1238	our $VERSION = '6.02';
1162	our $MODEL;	1239	our $MODEL;
1163
1164	our $AUTOLOAD;
1165	our @ISA;	1240	our @ISA;
1166
1167	our @REGISTRY;	1241	our @REGISTRY;
1168
1169	our $VERBOSE;	1242	our $VERBOSE;
		1243	our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred
		1244	our $MAX_SIGNAL_LATENCY = $ENV{PERL_ANYEVENT_MAX_SIGNAL_LATENCY} || 10; # executes after the BEGIN block below (tainting!)
1170		1245
1171	BEGIN {	1246	BEGIN {
1172	eval "sub CYGWIN(){" . (($^O =~ /cygwin/i) *1) . "}";	1247	require "AnyEvent/constants.pl";
1173	eval "sub WIN32 (){" . (($^O =~ /mswin32/i)*1) . "}";	1248
1174	eval "sub TAINT (){" . (${^TAINT} *1) . "}";	1249	eval "sub TAINT (){" . (${^TAINT}*1) . "}";
1175		1250
1176	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}	1251	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}
1177	if ${^TAINT};	1252	if ${^TAINT};
1178		1253
1179	$VERBOSE = $ENV{PERL_ANYEVENT_VERBOSE}*1;	1254	$ENV{"PERL_ANYEVENT_$_"} = $ENV{"AE_$_"}
		1255	for grep s/^AE_// && !exists $ENV{"PERL_ANYEVENT_$_"}, keys %ENV;
1180		1256
1181	}	1257	@ENV{grep /^PERL_ANYEVENT_/, keys %ENV} = ()
		1258	if ${^TAINT};
1182		1259
1183	our $MAX_SIGNAL_LATENCY = 10;	1260	# $ENV{PERL_ANYEVENT_xxx} now valid
1184		1261
1185	our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred	1262	$VERBOSE = length $ENV{PERL_ANYEVENT_VERBOSE} ? $ENV{PERL_ANYEVENT_VERBOSE}*1 : 4;
1186		1263
1187	{
1188	my $idx;	1264	my $idx;
1189	$PROTOCOL{$_} = ++$idx	1265	$PROTOCOL{$_} = ++$idx
1190	for reverse split /\s*,\s*/,	1266	for reverse split /\s*,\s*/,
1191	$ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";	1267	$ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";
1192	}	1268	}
1193		1269
		1270	our @post_detect;
		1271
		1272	sub post_detect(&) {
		1273	my ($cb) = @_;
		1274
		1275	push @post_detect, $cb;
		1276
		1277	defined wantarray
		1278	? bless \$cb, "AnyEvent::Util::postdetect"
		1279	: ()
		1280	}
		1281
		1282	sub AnyEvent::Util::postdetect::DESTROY {
		1283	@post_detect = grep $_ != ${$_[0]}, @post_detect;
		1284	}
		1285
		1286	our $POSTPONE_W;
		1287	our @POSTPONE;
		1288
		1289	sub _postpone_exec {
		1290	undef $POSTPONE_W;
		1291
		1292	&{ shift @POSTPONE }
		1293	while @POSTPONE;
		1294	}
		1295
		1296	sub postpone(&) {
		1297	push @POSTPONE, shift;
		1298
		1299	$POSTPONE_W ||= AE::timer (0, 0, \&_postpone_exec);
		1300
		1301	()
		1302	}
		1303
		1304	sub log($$;@) {
		1305	# only load the big bloated module when we actually are about to log something
		1306	if ($_[0] <= ($VERBOSE || 1)) { # also catches non-numeric levels(!) and fatal
		1307	require AnyEvent::Log; # among other things, sets $VERBOSE to 9
		1308	# AnyEvent::Log overwrites this function
		1309	goto &log;
		1310	}
		1311
		1312	0 # not logged
		1313	}
		1314
		1315	sub logger($;$) {
		1316	package AnyEvent::Log;
		1317
		1318	my ($level, $renabled) = @_;
		1319
		1320	$$renabled = $level <= $VERBOSE;
		1321
		1322	my $pkg = (caller)[0];
		1323
		1324	my $logger = [$pkg, $level, $renabled];
		1325
		1326	our %LOGGER;
		1327	$LOGGER{$logger+0} = $logger;
		1328
		1329	require AnyEvent::Util;
		1330	my $guard = AnyEvent::Util::guard (sub {
		1331	# "clean up"
		1332	delete $LOGGER{$logger+0};
		1333	});
		1334
		1335	sub {
		1336	return 0 unless $$renabled;
		1337
		1338	$guard if 0; # keep guard alive, but don't cause runtime overhead
		1339	require AnyEvent::Log unless $AnyEvent::Log::VERSION;
		1340	package AnyEvent::Log;
		1341	_log ($logger->[0], $level, @_) # logger->[0] has been converted at load time
		1342	}
		1343	}
		1344
		1345	if (length $ENV{PERL_ANYEVENT_LOG}) {
		1346	require AnyEvent::Log; # AnyEvent::Log does the thing for us
		1347	}
		1348
1194	my @models = (	1349	our @models = (
1195	[EV:: => AnyEvent::Impl::EV:: , 1],	1350	[EV:: => AnyEvent::Impl::EV::],
1196	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl:: , 1],	1351	[AnyEvent::Loop:: => AnyEvent::Impl::Perl::],
1197	# everything below here will not (normally) be autoprobed	1352	# everything below here will not (normally) be autoprobed
1198	# as the pureperl backend should work everywhere	1353	# as the pure perl backend should work everywhere
1199	# and is usually faster	1354	# and is usually faster
		1355	[Irssi:: => AnyEvent::Impl::Irssi::], # Irssi has a bogus "Event" package, so msut be near the top
1200	[Event:: => AnyEvent::Impl::Event::, 1],	1356	[Event:: => AnyEvent::Impl::Event::], # slow, stable
1201	[Glib:: => AnyEvent::Impl::Glib:: , 1], # becomes extremely slow with many watchers	1357	[Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers
		1358	# everything below here should not be autoloaded
1202	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy	1359	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
1203	[Irssi:: => AnyEvent::Impl::Irssi::], # Irssi has a bogus "Event" package
1204	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles	1360	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
1205	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program	1361	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program
1206	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza	1362	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
1207	[Wx:: => AnyEvent::Impl::POE::],	1363	[Wx:: => AnyEvent::Impl::POE::],
1208	[Prima:: => AnyEvent::Impl::POE::],	1364	[Prima:: => AnyEvent::Impl::POE::],
1209	# IO::Async is just too broken - we would need workarounds for its	1365	[IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # a bitch to autodetect
1210	# byzantine signal and broken child handling, among others.	1366	[Cocoa::EventLoop:: => AnyEvent::Impl::Cocoa::],
1211	# IO::Async is rather hard to detect, as it doesn't have any	1367	[FLTK:: => AnyEvent::Impl::FLTK::],
1212	# obvious default class.
1213	[IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program
1214	[IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program
1215	[IO::Async::Notifier:: => AnyEvent::Impl::IOAsync::], # requires special main program
1216	[AnyEvent::Impl::IOAsync:: => AnyEvent::Impl::IOAsync::], # requires special main program
1217	);	1368	);
1218		1369
1219	our %method = map +($_ => 1),	1370	our @isa_hook;
		1371
		1372	sub _isa_set {
		1373	my @pkg = ("AnyEvent", (map $_->[0], grep defined, @isa_hook), $MODEL);
		1374
		1375	@{"$pkg[$_-1]::ISA"} = $pkg[$_]
		1376	for 1 .. $#pkg;
		1377
		1378	grep $_ && $_->[1], @isa_hook
		1379	and AE::_reset ();
		1380	}
		1381
		1382	# used for hooking AnyEvent::Strict and AnyEvent::Debug::Wrap into the class hierarchy
		1383	sub _isa_hook($$;$) {
		1384	my ($i, $pkg, $reset_ae) = @_;
		1385
		1386	$isa_hook[$i] = $pkg ? [$pkg, $reset_ae] : undef;
		1387
		1388	_isa_set;
		1389	}
		1390
		1391	# all autoloaded methods reserve the complete glob, not just the method slot.
		1392	# due to bugs in perls method cache implementation.
1220	qw(io timer time now now_update signal child idle condvar one_event DESTROY);	1393	our @methods = qw(io timer time now now_update signal child idle condvar);
1221
1222	our @post_detect;
1223
1224	sub post_detect(&) {
1225	my ($cb) = @_;
1226
1227	if ($MODEL) {
1228	$cb->();
1229
1230	undef
1231	} else {
1232	push @post_detect, $cb;
1233
1234	defined wantarray
1235	? bless \$cb, "AnyEvent::Util::postdetect"
1236	: ()
1237	}
1238	}
1239
1240	sub AnyEvent::Util::postdetect::DESTROY {
1241	@post_detect = grep $_ != ${$_[0]}, @post_detect;
1242	}
1243		1394
1244	sub detect() {	1395	sub detect() {
		1396	return $MODEL if $MODEL; # some programs keep references to detect
		1397
		1398	# IO::Async::Loop::AnyEvent is extremely evil, refuse to work with it
		1399	# the author knows about the problems and what it does to AnyEvent as a whole
		1400	# (and the ability of others to use AnyEvent), but simply wants to abuse AnyEvent
		1401	# anyway.
		1402	AnyEvent::log fatal => "AnyEvent: IO::Async::Loop::AnyEvent detected - this module is broken by design,\n"
		1403	. "abuses internals and breaks AnyEvent, will not continue."
		1404	if exists $INC{"IO/Async/Loop/AnyEvent.pm"};
		1405
		1406	local $!; # for good measure
		1407	local $SIG{__DIE__}; # we use eval
		1408
1245	# free some memory	1409	# free some memory
1246	*detect = sub () { $MODEL };	1410	*detect = sub () { $MODEL };
		1411	# undef &func doesn't correctly update the method cache. grmbl.
		1412	# so we delete the whole glob. grmbl.
		1413	# otoh, perl doesn't let me undef an active usb, but it lets me free
		1414	# a glob with an active sub. hrm. i hope it works, but perl is
		1415	# usually buggy in this department. sigh.
		1416	delete @{"AnyEvent::"}{@methods};
		1417	undef @methods;
1247		1418
1248	local $!; # for good measure
1249	local $SIG{__DIE__};
1250
1251	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {	1419	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z0-9:]+)$/) {
1252	my $model = "AnyEvent::Impl::$1";	1420	my $model = $1;
		1421	$model = "AnyEvent::Impl::$model" unless $model =~ s/::$//;
1253	if (eval "require $model") {	1422	if (eval "require $model") {
		1423	AnyEvent::log 7 => "loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.";
1254	$MODEL = $model;	1424	$MODEL = $model;
1255	warn "AnyEvent: loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.\n" if $VERBOSE >= 2;
1256	} else {	1425	} else {
1257	warn "AnyEvent: unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@" if $VERBOSE;	1426	AnyEvent::log 4 => "unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@";
1258	}	1427	}
1259	}	1428	}
1260		1429
1261	# check for already loaded models	1430	# check for already loaded models
1262	unless ($MODEL) {	1431	unless ($MODEL) {
1263	for (@REGISTRY, @models) {	1432	for (@REGISTRY, @models) {
1264	my ($package, $model) = @$_;	1433	my ($package, $model) = @$_;
1265	if (${"$package\::VERSION"} > 0) {	1434	if (${"$package\::VERSION"} > 0) {
1266	if (eval "require $model") {	1435	if (eval "require $model") {
		1436	AnyEvent::log 7 => "autodetected model '$model', using it.";
1267	$MODEL = $model;	1437	$MODEL = $model;
1268	warn "AnyEvent: autodetected model '$model', using it.\n" if $VERBOSE >= 2;
1269	last;	1438	last;
1270	}	1439	}
1271	}	1440	}
1272	}	1441	}
1273		1442
1274	unless ($MODEL) {	1443	unless ($MODEL) {
1275	# try to autoload a model	1444	# try to autoload a model
1276	for (@REGISTRY, @models) {	1445	for (@REGISTRY, @models) {
1277	my ($package, $model, $autoload) = @$_;	1446	my ($package, $model) = @$_;
1278	if (	1447	if (
1279	$autoload
1280	and eval "require $package"	1448	eval "require $package"
1281	and ${"$package\::VERSION"} > 0	1449	and ${"$package\::VERSION"} > 0
1282	and eval "require $model"	1450	and eval "require $model"
1283	) {	1451	) {
		1452	AnyEvent::log 7 => "autoloaded model '$model', using it.";
1284	$MODEL = $model;	1453	$MODEL = $model;
1285	warn "AnyEvent: autoloaded model '$model', using it.\n" if $VERBOSE >= 2;
1286	last;	1454	last;
1287	}	1455	}
1288	}	1456	}
1289		1457
1290	$MODEL	1458	$MODEL
1291	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.\n";	1459	or AnyEvent::log fatal => "AnyEvent: backend autodetection failed - did you properly install AnyEvent?";
1292	}	1460	}
1293	}	1461	}
1294		1462
1295	@models = (); # free probe data	1463	# free memory only needed for probing
		1464	undef @models;
		1465	undef @REGISTRY;
1296		1466
1297	push @{"$MODEL\::ISA"}, "AnyEvent::Base";	1467	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
1298	unshift @ISA, $MODEL;
1299		1468
1300	require AnyEvent::Strict if $ENV{PERL_ANYEVENT_STRICT};	1469	# now nuke some methods that are overridden by the backend.
		1470	# SUPER usage is not allowed in these.
		1471	for (qw(time signal child idle)) {
		1472	undef &{"AnyEvent::Base::$_"}
		1473	if defined &{"$MODEL\::$_"};
		1474	}
		1475
		1476	_isa_set;
		1477
		1478	# we're officially open!
		1479
		1480	if ($ENV{PERL_ANYEVENT_STRICT}) {
		1481	require AnyEvent::Strict;
		1482	}
		1483
		1484	if ($ENV{PERL_ANYEVENT_DEBUG_WRAP}) {
		1485	require AnyEvent::Debug;
		1486	AnyEvent::Debug::wrap ($ENV{PERL_ANYEVENT_DEBUG_WRAP});
		1487	}
		1488
		1489	if (length $ENV{PERL_ANYEVENT_DEBUG_SHELL}) {
		1490	require AnyEvent::Socket;
		1491	require AnyEvent::Debug;
		1492
		1493	my $shell = $ENV{PERL_ANYEVENT_DEBUG_SHELL};
		1494	$shell =~ s/\$\$/$$/g;
		1495
		1496	my ($host, $service) = AnyEvent::Socket::parse_hostport ($shell);
		1497	$AnyEvent::Debug::SHELL = AnyEvent::Debug::shell ($host, $service);
		1498	}
		1499
		1500	# now the anyevent environment is set up as the user told us to, so
		1501	# call the actual user code - post detects
1301		1502
1302	(shift @post_detect)->() while @post_detect;	1503	(shift @post_detect)->() while @post_detect;
		1504	undef @post_detect;
		1505
		1506	*post_detect = sub(&) {
		1507	shift->();
		1508
		1509	undef
		1510	};
1303		1511
1304	$MODEL	1512	$MODEL
1305	}	1513	}
1306		1514
1307	sub AUTOLOAD {	1515	for my $name (@methods) {
1308	(my $func = $AUTOLOAD) =~ s/.*://;	1516	*$name = sub {
1309
1310	$method{$func}
1311	or Carp::croak "$func: not a valid AnyEvent class method";
1312
1313	detect;	1517	detect;
1314		1518	# we use goto because
1315	my $class = shift;	1519	# a) it makes the thunk more transparent
1316	$class->$func (@_);	1520	# b) it allows us to delete the thunk later
		1521	goto &{ UNIVERSAL::can AnyEvent => "SUPER::$name" }
		1522	};
1317	}	1523	}
1318		1524
1319	# utility function to dup a filehandle. this is used by many backends	1525	# utility function to dup a filehandle. this is used by many backends
1320	# to support binding more than one watcher per filehandle (they usually	1526	# to support binding more than one watcher per filehandle (they usually
1321	# allow only one watcher per fd, so we dup it to get a different one).	1527	# allow only one watcher per fd, so we dup it to get a different one).
…		…
1335		1541
1336	=head1 SIMPLIFIED AE API	1542	=head1 SIMPLIFIED AE API
1337		1543
1338	Starting with version 5.0, AnyEvent officially supports a second, much	1544	Starting with version 5.0, AnyEvent officially supports a second, much
1339	simpler, API that is designed to reduce the calling, typing and memory	1545	simpler, API that is designed to reduce the calling, typing and memory
1340	overhead.	1546	overhead by using function call syntax and a fixed number of parameters.
1341		1547
1342	See the L<AE> manpage for details.	1548	See the L<AE> manpage for details.
1343		1549
1344	=cut	1550	=cut
1345		1551
1346	package AE;	1552	package AE;
1347		1553
1348	our $VERSION = $AnyEvent::VERSION;	1554	our $VERSION = $AnyEvent::VERSION;
1349		1555
		1556	sub _reset() {
		1557	eval q{
		1558	# fall back to the main API by default - backends and AnyEvent::Base
		1559	# implementations can overwrite these.
		1560
1350	sub io($$$) {	1561	sub io($$$) {
1351	AnyEvent->io (fh => $_[0], poll => $_[1] ? "w" : "r", cb => $_[2])	1562	AnyEvent->io (fh => $_[0], poll => $_[1] ? "w" : "r", cb => $_[2])
1352	}	1563	}
1353		1564
1354	sub timer($$$) {	1565	sub timer($$$) {
1355	AnyEvent->timer (after => $_[0], interval => $_[1], cb => $_[2])	1566	AnyEvent->timer (after => $_[0], interval => $_[1], cb => $_[2])
1356	}	1567	}
1357		1568
1358	sub signal($$) {	1569	sub signal($$) {
1359	AnyEvent->signal (signal => $_[0], cb => $_[1])	1570	AnyEvent->signal (signal => $_[0], cb => $_[1])
1360	}	1571	}
1361		1572
1362	sub child($$) {	1573	sub child($$) {
1363	AnyEvent->child (pid => $_[0], cb => $_[1])	1574	AnyEvent->child (pid => $_[0], cb => $_[1])
1364	}	1575	}
1365		1576
1366	sub idle($) {	1577	sub idle($) {
1367	AnyEvent->idle (cb => $_[0])	1578	AnyEvent->idle (cb => $_[0]);
1368	}	1579	}
1369		1580
1370	sub cv(;&) {	1581	sub cv(;&) {
1371	AnyEvent->condvar (@_ ? (cb => $_[0]) : ())	1582	AnyEvent->condvar (@_ ? (cb => $_[0]) : ())
1372	}	1583	}
1373		1584
1374	sub now() {	1585	sub now() {
1375	AnyEvent->now	1586	AnyEvent->now
1376	}	1587	}
1377		1588
1378	sub now_update() {	1589	sub now_update() {
1379	AnyEvent->now_update	1590	AnyEvent->now_update
1380	}	1591	}
1381		1592
1382	sub time() {	1593	sub time() {
1383	AnyEvent->time	1594	AnyEvent->time
		1595	}
		1596
		1597	*postpone = \&AnyEvent::postpone;
		1598	*log = \&AnyEvent::log;
		1599	};
		1600	die if $@;
1384	}	1601	}
		1602
		1603	BEGIN { _reset }
1385		1604
1386	package AnyEvent::Base;	1605	package AnyEvent::Base;
1387		1606
1388	# default implementations for many methods	1607	# default implementations for many methods
1389		1608
1390	sub _time() {	1609	sub time {
1391	eval q{ # poor man's autoloading	1610	eval q{ # poor man's autoloading {}
1392	# probe for availability of Time::HiRes	1611	# probe for availability of Time::HiRes
1393	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {	1612	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {
1394	warn "AnyEvent: using Time::HiRes for sub-second timing accuracy.\n" if $VERBOSE >= 8;	1613	*time = sub { Time::HiRes::time () };
1395	*_time = \&Time::HiRes::time;	1614	*AE::time = \& Time::HiRes::time ;
		1615	*now = \&time;
		1616	AnyEvent::log 8 => "AnyEvent: using Time::HiRes for sub-second timing accuracy.";
1396	# if (eval "use POSIX (); (POSIX::times())...	1617	# if (eval "use POSIX (); (POSIX::times())...
1397	} else {	1618	} else {
		1619	*time = sub { CORE::time };
		1620	*AE::time = sub (){ CORE::time };
		1621	*now = \&time;
1398	warn "AnyEvent: using built-in time(), WARNING, no sub-second resolution!\n" if $VERBOSE;	1622	AnyEvent::log 3 => "using built-in time(), WARNING, no sub-second resolution!";
1399	*_time = sub (){ time }; # epic fail
1400	}	1623	}
1401	};	1624	};
1402	die if $@;	1625	die if $@;
1403		1626
1404	&_time	1627	&time
1405	}	1628	}
1406		1629
1407	sub time { _time }	1630	*now = \&time;
1408	sub now { _time }
1409	sub now_update { }	1631	sub now_update { }
1410		1632
		1633	sub _poll {
		1634	Carp::croak "$AnyEvent::MODEL does not support blocking waits. Caught";
		1635	}
		1636
1411	# default implementation for ->condvar	1637	# default implementation for ->condvar
		1638	# in fact, the default should not be overwritten
1412		1639
1413	sub condvar {	1640	sub condvar {
		1641	eval q{ # poor man's autoloading {}
		1642	*condvar = sub {
1414	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"	1643	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"
		1644	};
		1645
		1646	*AE::cv = sub (;&) {
		1647	bless { @_ ? (_ae_cb => shift) : () }, "AnyEvent::CondVar"
		1648	};
		1649	};
		1650	die if $@;
		1651
		1652	&condvar
1415	}	1653	}
1416		1654
1417	# default implementation for ->signal	1655	# default implementation for ->signal
1418		1656
1419	our $HAVE_ASYNC_INTERRUPT;	1657	our $HAVE_ASYNC_INTERRUPT;
…		…
1449	undef $SIG_TW	1687	undef $SIG_TW
1450	unless --$SIG_COUNT;	1688	unless --$SIG_COUNT;
1451	}	1689	}
1452		1690
1453	our $_sig_name_init; $_sig_name_init = sub {	1691	our $_sig_name_init; $_sig_name_init = sub {
1454	eval q{ # poor man's autoloading	1692	eval q{ # poor man's autoloading {}
1455	undef $_sig_name_init;	1693	undef $_sig_name_init;
1456		1694
1457	if (_have_async_interrupt) {	1695	if (_have_async_interrupt) {
1458	*sig2num = \&Async::Interrupt::sig2num;	1696	*sig2num = \&Async::Interrupt::sig2num;
1459	*sig2name = \&Async::Interrupt::sig2name;	1697	*sig2name = \&Async::Interrupt::sig2name;
…		…
1483		1721
1484	sub signal {	1722	sub signal {
1485	eval q{ # poor man's autoloading {}	1723	eval q{ # poor man's autoloading {}
1486	# probe for availability of Async::Interrupt	1724	# probe for availability of Async::Interrupt
1487	if (_have_async_interrupt) {	1725	if (_have_async_interrupt) {
1488	warn "AnyEvent: using Async::Interrupt for race-free signal handling.\n" if $VERBOSE >= 8;	1726	AnyEvent::log 8 => "using Async::Interrupt for race-free signal handling.";
1489		1727
1490	$SIGPIPE_R = new Async::Interrupt::EventPipe;	1728	$SIGPIPE_R = new Async::Interrupt::EventPipe;
1491	$SIG_IO = AE::io $SIGPIPE_R->fileno, 0, \&_signal_exec;	1729	$SIG_IO = AE::io $SIGPIPE_R->fileno, 0, \&_signal_exec;
1492		1730
1493	} else {	1731	} else {
1494	warn "AnyEvent: using emulated perl signal handling with latency timer.\n" if $VERBOSE >= 8;	1732	AnyEvent::log 8 => "using emulated perl signal handling with latency timer.";
1495
1496	require Fcntl;
1497		1733
1498	if (AnyEvent::WIN32) {	1734	if (AnyEvent::WIN32) {
1499	require AnyEvent::Util;	1735	require AnyEvent::Util;
1500		1736
1501	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();	1737	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
1502	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R, 1) if $SIGPIPE_R;	1738	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R, 1) if $SIGPIPE_R;
1503	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W, 1) if $SIGPIPE_W; # just in case	1739	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W, 1) if $SIGPIPE_W; # just in case
1504	} else {	1740	} else {
1505	pipe $SIGPIPE_R, $SIGPIPE_W;	1741	pipe $SIGPIPE_R, $SIGPIPE_W;
1506	fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R;	1742	fcntl $SIGPIPE_R, AnyEvent::F_SETFL, AnyEvent::O_NONBLOCK if $SIGPIPE_R;
1507	fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case	1743	fcntl $SIGPIPE_W, AnyEvent::F_SETFL, AnyEvent::O_NONBLOCK if $SIGPIPE_W; # just in case
1508		1744
1509	# not strictly required, as $^F is normally 2, but let's make sure...	1745	# not strictly required, as $^F is normally 2, but let's make sure...
1510	fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;	1746	fcntl $SIGPIPE_R, AnyEvent::F_SETFD, AnyEvent::FD_CLOEXEC;
1511	fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;	1747	fcntl $SIGPIPE_W, AnyEvent::F_SETFD, AnyEvent::FD_CLOEXEC;
1512	}	1748	}
1513		1749
1514	$SIGPIPE_R	1750	$SIGPIPE_R
1515	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";	1751	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";
1516		1752
1517	$SIG_IO = AE::io $SIGPIPE_R, 0, \&_signal_exec;	1753	$SIG_IO = AE::io $SIGPIPE_R, 0, \&_signal_exec;
1518	}	1754	}
1519		1755
1520	*signal = sub {	1756	*signal = $HAVE_ASYNC_INTERRUPT
		1757	? sub {
1521	my (undef, %arg) = @_;	1758	my (undef, %arg) = @_;
1522		1759
1523	my $signal = uc $arg{signal}
1524	or Carp::croak "required option 'signal' is missing";
1525
1526	if ($HAVE_ASYNC_INTERRUPT) {
1527	# async::interrupt	1760	# async::interrupt
1528
1529	$signal = sig2num $signal;	1761	my $signal = sig2num $arg{signal};
1530	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};	1762	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
1531		1763
1532	$SIG_ASY{$signal} ||= new Async::Interrupt	1764	$SIG_ASY{$signal} ||= new Async::Interrupt
1533	cb => sub { undef $SIG_EV{$signal} },	1765	cb => sub { undef $SIG_EV{$signal} },
1534	signal => $signal,	1766	signal => $signal,
1535	pipe => [$SIGPIPE_R->filenos],	1767	pipe => [$SIGPIPE_R->filenos],
1536	pipe_autodrain => 0,	1768	pipe_autodrain => 0,
1537	;	1769	;
1538		1770
1539	} else {	1771	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
		1772	}
		1773	: sub {
		1774	my (undef, %arg) = @_;
		1775
1540	# pure perl	1776	# pure perl
1541
1542	# AE::Util has been loaded in signal
1543	$signal = sig2name $signal;	1777	my $signal = sig2name $arg{signal};
1544	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};	1778	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
1545		1779
1546	$SIG{$signal} ||= sub {	1780	$SIG{$signal} ||= sub {
1547	local $!;	1781	local $!;
1548	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;	1782	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;
1549	undef $SIG_EV{$signal};	1783	undef $SIG_EV{$signal};
1550	};	1784	};
1551		1785
1552	# can't do signal processing without introducing races in pure perl,	1786	# can't do signal processing without introducing races in pure perl,
1553	# so limit the signal latency.	1787	# so limit the signal latency.
1554	_sig_add;	1788	_sig_add;
1555	}
1556		1789
1557	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"	1790	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
		1791	}
1558	};	1792	;
1559		1793
1560	*AnyEvent::Base::signal::DESTROY = sub {	1794	*AnyEvent::Base::signal::DESTROY = sub {
1561	my ($signal, $cb) = @{$_[0]};	1795	my ($signal, $cb) = @{$_[0]};
1562		1796
1563	_sig_del;	1797	_sig_del;
…		…
1579	: sysread $SIGPIPE_R, (my $dummy), 9;	1813	: sysread $SIGPIPE_R, (my $dummy), 9;
1580		1814
1581	while (%SIG_EV) {	1815	while (%SIG_EV) {
1582	for (keys %SIG_EV) {	1816	for (keys %SIG_EV) {
1583	delete $SIG_EV{$_};	1817	delete $SIG_EV{$_};
1584	$_->() for values %{ $SIG_CB{$_} || {} };	1818	&$_ for values %{ $SIG_CB{$_} || {} };
1585	}	1819	}
1586	}	1820	}
1587	};	1821	};
1588	};	1822	};
1589	die if $@;	1823	die if $@;
…		…
1594	# default implementation for ->child	1828	# default implementation for ->child
1595		1829
1596	our %PID_CB;	1830	our %PID_CB;
1597	our $CHLD_W;	1831	our $CHLD_W;
1598	our $CHLD_DELAY_W;	1832	our $CHLD_DELAY_W;
1599	our $WNOHANG;
1600		1833
1601	# used by many Impl's	1834	# used by many Impl's
1602	sub _emit_childstatus($$) {	1835	sub _emit_childstatus($$) {
1603	my (undef, $rpid, $rstatus) = @_;	1836	my (undef, $rpid, $rstatus) = @_;
1604		1837
…		…
1611	eval q{ # poor man's autoloading {}	1844	eval q{ # poor man's autoloading {}
1612	*_sigchld = sub {	1845	*_sigchld = sub {
1613	my $pid;	1846	my $pid;
1614		1847
1615	AnyEvent->_emit_childstatus ($pid, $?)	1848	AnyEvent->_emit_childstatus ($pid, $?)
1616	while ($pid = waitpid -1, $WNOHANG) > 0;	1849	while ($pid = waitpid -1, WNOHANG) > 0;
1617	};	1850	};
1618		1851
1619	*child = sub {	1852	*child = sub {
1620	my (undef, %arg) = @_;	1853	my (undef, %arg) = @_;
1621		1854
1622	defined (my $pid = $arg{pid} + 0)	1855	my $pid = $arg{pid};
1623	or Carp::croak "required option 'pid' is missing";	1856	my $cb = $arg{cb};
1624		1857
1625	$PID_CB{$pid}{$arg{cb}} = $arg{cb};	1858	$PID_CB{$pid}{$cb+0} = $cb;
1626
1627	# WNOHANG is almost cetrainly 1 everywhere
1628	$WNOHANG ||= $^O =~ /^(?:openbsd|netbsd|linux|freebsd|cygwin|MSWin32)$/
1629	? 1
1630	: eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1;
1631		1859
1632	unless ($CHLD_W) {	1860	unless ($CHLD_W) {
1633	$CHLD_W = AE::signal CHLD => \&_sigchld;	1861	$CHLD_W = AE::signal CHLD => \&_sigchld;
1634	# child could be a zombie already, so make at least one round	1862	# child could be a zombie already, so make at least one round
1635	&_sigchld;	1863	&_sigchld;
1636	}	1864	}
1637		1865
1638	bless [$pid, $arg{cb}], "AnyEvent::Base::child"	1866	bless [$pid, $cb+0], "AnyEvent::Base::child"
1639	};	1867	};
1640		1868
1641	*AnyEvent::Base::child::DESTROY = sub {	1869	*AnyEvent::Base::child::DESTROY = sub {
1642	my ($pid, $cb) = @{$_[0]};	1870	my ($pid, $icb) = @{$_[0]};
1643		1871
1644	delete $PID_CB{$pid}{$cb};	1872	delete $PID_CB{$pid}{$icb};
1645	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };	1873	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };
1646		1874
1647	undef $CHLD_W unless keys %PID_CB;	1875	undef $CHLD_W unless keys %PID_CB;
1648	};	1876	};
1649	};	1877	};
…		…
1662		1890
1663	my ($cb, $w, $rcb) = $arg{cb};	1891	my ($cb, $w, $rcb) = $arg{cb};
1664		1892
1665	$rcb = sub {	1893	$rcb = sub {
1666	if ($cb) {	1894	if ($cb) {
1667	$w = _time;	1895	$w = AE::time;
1668	&$cb;	1896	&$cb;
1669	$w = _time - $w;	1897	$w = AE::time - $w;
1670		1898
1671	# never use more then 50% of the time for the idle watcher,	1899	# never use more then 50% of the time for the idle watcher,
1672	# within some limits	1900	# within some limits
1673	$w = 0.0001 if $w < 0.0001;	1901	$w = 0.0001 if $w < 0.0001;
1674	$w = 5 if $w > 5;	1902	$w = 5 if $w > 5;
…		…
1697		1925
1698	package AnyEvent::CondVar;	1926	package AnyEvent::CondVar;
1699		1927
1700	our @ISA = AnyEvent::CondVar::Base::;	1928	our @ISA = AnyEvent::CondVar::Base::;
1701		1929
		1930	# only to be used for subclassing
		1931	sub new {
		1932	my $class = shift;
		1933	bless AnyEvent->condvar (@_), $class
		1934	}
		1935
1702	package AnyEvent::CondVar::Base;	1936	package AnyEvent::CondVar::Base;
1703		1937
1704	#use overload	1938	#use overload
1705	# '&{}' => sub { my $self = shift; sub { $self->send (@_) } },	1939	# '&{}' => sub { my $self = shift; sub { $self->send (@_) } },
1706	# fallback => 1;	1940	# fallback => 1;
…		…
1715		1949
1716	sub _send {	1950	sub _send {
1717	# nop	1951	# nop
1718	}	1952	}
1719		1953
		1954	sub _wait {
		1955	AnyEvent->_poll until $_[0]{_ae_sent};
		1956	}
		1957
1720	sub send {	1958	sub send {
1721	my $cv = shift;	1959	my $cv = shift;
1722	$cv->{_ae_sent} = [@_];	1960	$cv->{_ae_sent} = [@_];
1723	(delete $cv->{_ae_cb})->($cv) if $cv->{_ae_cb};	1961	(delete $cv->{_ae_cb})->($cv) if $cv->{_ae_cb};
1724	$cv->_send;	1962	$cv->_send;
…		…
1731		1969
1732	sub ready {	1970	sub ready {
1733	$_[0]{_ae_sent}	1971	$_[0]{_ae_sent}
1734	}	1972	}
1735		1973
1736	sub _wait {
1737	$WAITING
1738	and !$_[0]{_ae_sent}
1739	and Carp::croak "AnyEvent::CondVar: recursive blocking wait detected";
1740
1741	local $WAITING = 1;
1742	AnyEvent->one_event while !$_[0]{_ae_sent};
1743	}
1744
1745	sub recv {	1974	sub recv {
		1975	unless ($_[0]{_ae_sent}) {
		1976	$WAITING
		1977	and Carp::croak "AnyEvent::CondVar: recursive blocking wait attempted";
		1978
		1979	local $WAITING = 1;
1746	$_[0]->_wait;	1980	$_[0]->_wait;
		1981	}
1747		1982
1748	Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak};	1983	$_[0]{_ae_croak}
1749	wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0]	1984	and Carp::croak $_[0]{_ae_croak};
		1985
		1986	wantarray
		1987	? @{ $_[0]{_ae_sent} }
		1988	: $_[0]{_ae_sent}[0]
1750	}	1989	}
1751		1990
1752	sub cb {	1991	sub cb {
1753	my $cv = shift;	1992	my $cv = shift;
1754		1993
…		…
1770	&{ $_[0]{_ae_end_cb} || sub { $_[0]->send } };	2009	&{ $_[0]{_ae_end_cb} || sub { $_[0]->send } };
1771	}	2010	}
1772		2011
1773	# undocumented/compatibility with pre-3.4	2012	# undocumented/compatibility with pre-3.4
1774	*broadcast = \&send;	2013	*broadcast = \&send;
1775	*wait = \&_wait;	2014	*wait = \&recv;
1776		2015
1777	=head1 ERROR AND EXCEPTION HANDLING	2016	=head1 ERROR AND EXCEPTION HANDLING
1778		2017
1779	In general, AnyEvent does not do any error handling - it relies on the	2018	In general, AnyEvent does not do any error handling - it relies on the
1780	caller to do that if required. The L<AnyEvent::Strict> module (see also	2019	caller to do that if required. The L<AnyEvent::Strict> module (see also
…		…
1792	$Event/EV::DIED->() >>, L<Glib> uses C<< install_exception_handler >> and	2031	$Event/EV::DIED->() >>, L<Glib> uses C<< install_exception_handler >> and
1793	so on.	2032	so on.
1794		2033
1795	=head1 ENVIRONMENT VARIABLES	2034	=head1 ENVIRONMENT VARIABLES
1796		2035
1797	The following environment variables are used by this module or its	2036	AnyEvent supports a number of environment variables that tune the
1798	submodules.	2037	runtime behaviour. They are usually evaluated when AnyEvent is
		2038	loaded, initialised, or a submodule that uses them is loaded. Many of
		2039	them also cause AnyEvent to load additional modules - for example,
		2040	C<PERL_ANYEVENT_DEBUG_WRAP> causes the L<AnyEvent::Debug> module to be
		2041	loaded.
1799		2042
1800	Note that AnyEvent will remove I<all> environment variables starting with	2043	All the environment variables documented here start with
1801	C<PERL_ANYEVENT_> from C<%ENV> when it is loaded while taint mode is	2044	C<PERL_ANYEVENT_>, which is what AnyEvent considers its own
1802	enabled.	2045	namespace. Other modules are encouraged (but by no means required) to use
		2046	C<PERL_ANYEVENT_SUBMODULE> if they have registered the AnyEvent::Submodule
		2047	namespace on CPAN, for any submodule. For example, L<AnyEvent::HTTP> could
		2048	be expected to use C<PERL_ANYEVENT_HTTP_PROXY> (it should not access env
		2049	variables starting with C<AE_>, see below).
		2050
		2051	All variables can also be set via the C<AE_> prefix, that is, instead
		2052	of setting C<PERL_ANYEVENT_VERBOSE> you can also set C<AE_VERBOSE>. In
		2053	case there is a clash btween anyevent and another program that uses
		2054	C<AE_something> you can set the corresponding C<PERL_ANYEVENT_something>
		2055	variable to the empty string, as those variables take precedence.
		2056
		2057	When AnyEvent is first loaded, it copies all C<AE_xxx> env variables
		2058	to their C<PERL_ANYEVENT_xxx> counterpart unless that variable already
		2059	exists. If taint mode is on, then AnyEvent will remove I<all> environment
		2060	variables starting with C<PERL_ANYEVENT_> from C<%ENV> (or replace them
		2061	with C<undef> or the empty string, if the corresaponding C<AE_> variable
		2062	is set).
		2063
		2064	The exact algorithm is currently:
		2065
		2066	1. if taint mode enabled, delete all PERL_ANYEVENT_xyz variables from %ENV
		2067	2. copy over AE_xyz to PERL_ANYEVENT_xyz unless the latter alraedy exists
		2068	3. if taint mode enabled, set all PERL_ANYEVENT_xyz variables to undef.
		2069
		2070	This ensures that child processes will not see the C<AE_> variables.
		2071
		2072	The following environment variables are currently known to AnyEvent:
1803		2073
1804	=over 4	2074	=over 4
1805		2075
1806	=item C<PERL_ANYEVENT_VERBOSE>	2076	=item C<PERL_ANYEVENT_VERBOSE>
1807		2077
1808	By default, AnyEvent will be completely silent except in fatal	2078	By default, AnyEvent will only log messages with loglevel C<3>
1809	conditions. You can set this environment variable to make AnyEvent more	2079	(C<critical>) or higher (see L<AnyEvent::Log>). You can set this
		2080	environment variable to a numerical loglevel to make AnyEvent more (or
1810	talkative.	2081	less) talkative.
1811		2082
		2083	If you want to do more than just set the global logging level
		2084	you should have a look at C<PERL_ANYEVENT_LOG>, which allows much more
		2085	complex specifications.
		2086
		2087	When set to C<0> (C<off>), then no messages whatsoever will be logged with
		2088	the default logging settings.
		2089
1812	When set to C<1> or higher, causes AnyEvent to warn about unexpected	2090	When set to C<5> or higher (C<warn>), causes AnyEvent to warn about
1813	conditions, such as not being able to load the event model specified by	2091	unexpected conditions, such as not being able to load the event model
1814	C<PERL_ANYEVENT_MODEL>.	2092	specified by C<PERL_ANYEVENT_MODEL>, or a guard callback throwing an
		2093	exception - this is the minimum recommended level.
1815		2094
1816	When set to C<2> or higher, cause AnyEvent to report to STDERR which event	2095	When set to C<7> or higher (info), cause AnyEvent to report which event model it
1817	model it chooses.	2096	chooses.
1818		2097
1819	When set to C<8> or higher, then AnyEvent will report extra information on	2098	When set to C<8> or higher (debug), then AnyEvent will report extra information on
1820	which optional modules it loads and how it implements certain features.	2099	which optional modules it loads and how it implements certain features.
		2100
		2101	=item C<PERL_ANYEVENT_LOG>
		2102
		2103	Accepts rather complex logging specifications. For example, you could log
		2104	all C<debug> messages of some module to stderr, warnings and above to
		2105	stderr, and errors and above to syslog, with:
		2106
		2107	PERL_ANYEVENT_LOG=Some::Module=debug,+log:filter=warn,+%syslog:%syslog=error,syslog
		2108
		2109	For the rather extensive details, see L<AnyEvent::Log>.
		2110
		2111	This variable is evaluated when AnyEvent (or L<AnyEvent::Log>) is loaded,
		2112	so will take effect even before AnyEvent has initialised itself.
		2113
		2114	Note that specifying this environment variable causes the L<AnyEvent::Log>
		2115	module to be loaded, while C<PERL_ANYEVENT_VERBOSE> does not, so only
		2116	using the latter saves a few hundred kB of memory until the first message
		2117	is being logged.
1821		2118
1822	=item C<PERL_ANYEVENT_STRICT>	2119	=item C<PERL_ANYEVENT_STRICT>
1823		2120
1824	AnyEvent does not do much argument checking by default, as thorough	2121	AnyEvent does not do much argument checking by default, as thorough
1825	argument checking is very costly. Setting this variable to a true value	2122	argument checking is very costly. Setting this variable to a true value
…		…
1827	check the arguments passed to most method calls. If it finds any problems,	2124	check the arguments passed to most method calls. If it finds any problems,
1828	it will croak.	2125	it will croak.
1829		2126
1830	In other words, enables "strict" mode.	2127	In other words, enables "strict" mode.
1831		2128
1832	Unlike C<use strict> (or it's modern cousin, C<< use L<common::sense>	2129	Unlike C<use strict> (or its modern cousin, C<< use L<common::sense>
1833	>>, it is definitely recommended to keep it off in production. Keeping	2130	>>, it is definitely recommended to keep it off in production. Keeping
1834	C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs	2131	C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs
1835	can be very useful, however.	2132	can be very useful, however.
1836		2133
		2134	=item C<PERL_ANYEVENT_DEBUG_SHELL>
		2135
		2136	If this env variable is nonempty, then its contents will be interpreted by
		2137	C<AnyEvent::Socket::parse_hostport> and C<AnyEvent::Debug::shell> (after
		2138	replacing every occurance of C<$$> by the process pid). The shell object
		2139	is saved in C<$AnyEvent::Debug::SHELL>.
		2140
		2141	This happens when the first watcher is created.
		2142
		2143	For example, to bind a debug shell on a unix domain socket in
		2144	F<< /tmp/debug<pid>.sock >>, you could use this:
		2145
		2146	PERL_ANYEVENT_DEBUG_SHELL=/tmp/debug\$\$.sock perlprog
		2147	# connect with e.g.: socat readline /tmp/debug123.sock
		2148
		2149	Or to bind to tcp port 4545 on localhost:
		2150
		2151	PERL_ANYEVENT_DEBUG_SHELL=127.0.0.1:4545 perlprog
		2152	# connect with e.g.: telnet localhost 4545
		2153
		2154	Note that creating sockets in F</tmp> or on localhost is very unsafe on
		2155	multiuser systems.
		2156
		2157	=item C<PERL_ANYEVENT_DEBUG_WRAP>
		2158
		2159	Can be set to C<0>, C<1> or C<2> and enables wrapping of all watchers for
		2160	debugging purposes. See C<AnyEvent::Debug::wrap> for details.
		2161
1837	=item C<PERL_ANYEVENT_MODEL>	2162	=item C<PERL_ANYEVENT_MODEL>
1838		2163
1839	This can be used to specify the event model to be used by AnyEvent, before	2164	This can be used to specify the event model to be used by AnyEvent, before
1840	auto detection and -probing kicks in. It must be a string consisting	2165	auto detection and -probing kicks in.
1841	entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended	2166
		2167	It normally is a string consisting entirely of ASCII letters (e.g. C<EV>
		2168	or C<IOAsync>). The string C<AnyEvent::Impl::> gets prepended and the
1842	and the resulting module name is loaded and if the load was successful,	2169	resulting module name is loaded and - if the load was successful - used as
1843	used as event model. If it fails to load AnyEvent will proceed with	2170	event model backend. If it fails to load then AnyEvent will proceed with
1844	auto detection and -probing.	2171	auto detection and -probing.
1845		2172
1846	This functionality might change in future versions.	2173	If the string ends with C<::> instead (e.g. C<AnyEvent::Impl::EV::>) then
		2174	nothing gets prepended and the module name is used as-is (hint: C<::> at
		2175	the end of a string designates a module name and quotes it appropriately).
1847		2176
1848	For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you	2177	For example, to force the pure perl model (L<AnyEvent::Loop::Perl>) you
1849	could start your program like this:	2178	could start your program like this:
1850		2179
1851	PERL_ANYEVENT_MODEL=Perl perl ...	2180	PERL_ANYEVENT_MODEL=Perl perl ...
1852		2181
1853	=item C<PERL_ANYEVENT_PROTOCOLS>	2182	=item C<PERL_ANYEVENT_PROTOCOLS>
…		…
1869	but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4>	2198	but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4>
1870	- only support IPv4, never try to resolve or contact IPv6	2199	- only support IPv4, never try to resolve or contact IPv6
1871	addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or	2200	addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or
1872	IPv6, but prefer IPv6 over IPv4.	2201	IPv6, but prefer IPv6 over IPv4.
1873		2202
		2203	=item C<PERL_ANYEVENT_HOSTS>
		2204
		2205	This variable, if specified, overrides the F</etc/hosts> file used by
		2206	L<AnyEvent::Socket>C<::resolve_sockaddr>, i.e. hosts aliases will be read
		2207	from that file instead.
		2208
1874	=item C<PERL_ANYEVENT_EDNS0>	2209	=item C<PERL_ANYEVENT_EDNS0>
1875		2210
1876	Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension	2211	Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension for
1877	for DNS. This extension is generally useful to reduce DNS traffic, but	2212	DNS. This extension is generally useful to reduce DNS traffic, especially
1878	some (broken) firewalls drop such DNS packets, which is why it is off by	2213	when DNSSEC is involved, but some (broken) firewalls drop such DNS
1879	default.	2214	packets, which is why it is off by default.
1880		2215
1881	Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce	2216	Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce
1882	EDNS0 in its DNS requests.	2217	EDNS0 in its DNS requests.
1883		2218
1884	=item C<PERL_ANYEVENT_MAX_FORKS>	2219	=item C<PERL_ANYEVENT_MAX_FORKS>
…		…
1890		2225
1891	The default value for the C<max_outstanding> parameter for the default DNS	2226	The default value for the C<max_outstanding> parameter for the default DNS
1892	resolver - this is the maximum number of parallel DNS requests that are	2227	resolver - this is the maximum number of parallel DNS requests that are
1893	sent to the DNS server.	2228	sent to the DNS server.
1894		2229
		2230	=item C<PERL_ANYEVENT_MAX_SIGNAL_LATENCY>
		2231
		2232	Perl has inherently racy signal handling (you can basically choose between
		2233	losing signals and memory corruption) - pure perl event loops (including
		2234	C<AnyEvent::Loop>, when C<Async::Interrupt> isn't available) therefore
		2235	have to poll regularly to avoid losing signals.
		2236
		2237	Some event loops are racy, but don't poll regularly, and some event loops
		2238	are written in C but are still racy. For those event loops, AnyEvent
		2239	installs a timer that regularly wakes up the event loop.
		2240
		2241	By default, the interval for this timer is C<10> seconds, but you can
		2242	override this delay with this environment variable (or by setting
		2243	the C<$AnyEvent::MAX_SIGNAL_LATENCY> variable before creating signal
		2244	watchers).
		2245
		2246	Lower values increase CPU (and energy) usage, higher values can introduce
		2247	long delays when reaping children or waiting for signals.
		2248
		2249	The L<AnyEvent::Async> module, if available, will be used to avoid this
		2250	polling (with most event loops).
		2251
1895	=item C<PERL_ANYEVENT_RESOLV_CONF>	2252	=item C<PERL_ANYEVENT_RESOLV_CONF>
1896		2253
1897	The file to use instead of F</etc/resolv.conf> (or OS-specific	2254	The absolute path to a F<resolv.conf>-style file to use instead of
1898	configuration) in the default resolver. When set to the empty string, no	2255	F</etc/resolv.conf> (or the OS-specific configuration) in the default
1899	default config will be used.	2256	resolver, or the empty string to select the default configuration.
1900		2257
1901	=item C<PERL_ANYEVENT_CA_FILE>, C<PERL_ANYEVENT_CA_PATH>.	2258	=item C<PERL_ANYEVENT_CA_FILE>, C<PERL_ANYEVENT_CA_PATH>.
1902		2259
1903	When neither C<ca_file> nor C<ca_path> was specified during	2260	When neither C<ca_file> nor C<ca_path> was specified during
1904	L<AnyEvent::TLS> context creation, and either of these environment	2261	L<AnyEvent::TLS> context creation, and either of these environment
1905	variables exist, they will be used to specify CA certificate locations	2262	variables are nonempty, they will be used to specify CA certificate
1906	instead of a system-dependent default.	2263	locations instead of a system-dependent default.
1907		2264
1908	=item C<PERL_ANYEVENT_AVOID_GUARD> and C<PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT>	2265	=item C<PERL_ANYEVENT_AVOID_GUARD> and C<PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT>
1909		2266
1910	When these are set to C<1>, then the respective modules are not	2267	When these are set to C<1>, then the respective modules are not
1911	loaded. Mostly good for testing AnyEvent itself.	2268	loaded. Mostly good for testing AnyEvent itself.
…		…
2059		2416
2060	The actual code goes further and collects all errors (C<die>s, exceptions)	2417	The actual code goes further and collects all errors (C<die>s, exceptions)
2061	that occurred during request processing. The C<result> method detects	2418	that occurred during request processing. The C<result> method detects
2062	whether an exception as thrown (it is stored inside the $txn object)	2419	whether an exception as thrown (it is stored inside the $txn object)
2063	and just throws the exception, which means connection errors and other	2420	and just throws the exception, which means connection errors and other
2064	problems get reported tot he code that tries to use the result, not in a	2421	problems get reported to the code that tries to use the result, not in a
2065	random callback.	2422	random callback.
2066		2423
2067	All of this enables the following usage styles:	2424	All of this enables the following usage styles:
2068		2425
2069	1. Blocking:	2426	1. Blocking:
…		…
2243	(even when used without AnyEvent), but most event loops have acceptable	2600	(even when used without AnyEvent), but most event loops have acceptable
2244	performance with or without AnyEvent.	2601	performance with or without AnyEvent.
2245		2602
2246	=item * The overhead AnyEvent adds is usually much smaller than the overhead of	2603	=item * The overhead AnyEvent adds is usually much smaller than the overhead of
2247	the actual event loop, only with extremely fast event loops such as EV	2604	the actual event loop, only with extremely fast event loops such as EV
2248	adds AnyEvent significant overhead.	2605	does AnyEvent add significant overhead.
2249		2606
2250	=item * You should avoid POE like the plague if you want performance or	2607	=item * You should avoid POE like the plague if you want performance or
2251	reasonable memory usage.	2608	reasonable memory usage.
2252		2609
2253	=back	2610	=back
…		…
2483	unless defined $SIG{PIPE};	2840	unless defined $SIG{PIPE};
2484		2841
2485	=head1 RECOMMENDED/OPTIONAL MODULES	2842	=head1 RECOMMENDED/OPTIONAL MODULES
2486		2843
2487	One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and	2844	One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and
2488	it's built-in modules) are required to use it.	2845	its built-in modules) are required to use it.
2489		2846
2490	That does not mean that AnyEvent won't take advantage of some additional	2847	That does not mean that AnyEvent won't take advantage of some additional
2491	modules if they are installed.	2848	modules if they are installed.
2492		2849
2493	This section explains which additional modules will be used, and how they	2850	This section explains which additional modules will be used, and how they
…		…
2526	automatic timer adjustments even when no monotonic clock is available,	2883	automatic timer adjustments even when no monotonic clock is available,
2527	can take avdantage of advanced kernel interfaces such as C<epoll> and	2884	can take avdantage of advanced kernel interfaces such as C<epoll> and
2528	C<kqueue>, and is the fastest backend I<by far>. You can even embed	2885	C<kqueue>, and is the fastest backend I<by far>. You can even embed
2529	L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>).	2886	L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>).
2530		2887
		2888	If you only use backends that rely on another event loop (e.g. C<Tk>),
		2889	then this module will do nothing for you.
		2890
2531	=item L<Guard>	2891	=item L<Guard>
2532		2892
2533	The guard module, when used, will be used to implement	2893	The guard module, when used, will be used to implement
2534	C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a	2894	C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a
2535	lot less memory), but otherwise doesn't affect guard operation much. It is	2895	lot less memory), but otherwise doesn't affect guard operation much. It is
2536	purely used for performance.	2896	purely used for performance.
2537		2897
2538	=item L<JSON> and L<JSON::XS>	2898	=item L<JSON> and L<JSON::XS>
2539		2899
2540	One of these modules is required when you want to read or write JSON data	2900	One of these modules is required when you want to read or write JSON data
2541	via L<AnyEvent::Handle>. It is also written in pure-perl, but can take	2901	via L<AnyEvent::Handle>. L<JSON> is also written in pure-perl, but can take
2542	advantage of the ultra-high-speed L<JSON::XS> module when it is installed.	2902	advantage of the ultra-high-speed L<JSON::XS> module when it is installed.
2543
2544	In fact, L<AnyEvent::Handle> will use L<JSON::XS> by default if it is
2545	installed.
2546		2903
2547	=item L<Net::SSLeay>	2904	=item L<Net::SSLeay>
2548		2905
2549	Implementing TLS/SSL in Perl is certainly interesting, but not very	2906	Implementing TLS/SSL in Perl is certainly interesting, but not very
2550	worthwhile: If this module is installed, then L<AnyEvent::Handle> (with	2907	worthwhile: If this module is installed, then L<AnyEvent::Handle> (with
2551	the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL.	2908	the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL.
2552		2909
2553	=item L<Time::HiRes>	2910	=item L<Time::HiRes>
2554		2911
2555	This module is part of perl since release 5.008. It will be used when the	2912	This module is part of perl since release 5.008. It will be used when the
2556	chosen event library does not come with a timing source on it's own. The	2913	chosen event library does not come with a timing source of its own. The
2557	pure-perl event loop (L<AnyEvent::Impl::Perl>) will additionally use it to	2914	pure-perl event loop (L<AnyEvent::Loop>) will additionally load it to
2558	try to use a monotonic clock for timing stability.	2915	try to use a monotonic clock for timing stability.
2559		2916
2560	=back	2917	=back
2561		2918
2562		2919
…		…
2624	pronounced).	2981	pronounced).
2625		2982
2626		2983
2627	=head1 SEE ALSO	2984	=head1 SEE ALSO
2628		2985
2629	Utility functions: L<AnyEvent::Util>.	2986	Tutorial/Introduction: L<AnyEvent::Intro>.
2630		2987
2631	Event modules: L<EV>, L<EV::Glib>, L<Glib::EV>, L<Event>, L<Glib::Event>,	2988	FAQ: L<AnyEvent::FAQ>.
2632	L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.	2989
		2990	Utility functions: L<AnyEvent::Util> (misc. grab-bag), L<AnyEvent::Log>
		2991	(simply logging).
		2992
		2993	Development/Debugging: L<AnyEvent::Strict> (stricter checking),
		2994	L<AnyEvent::Debug> (interactive shell, watcher tracing).
		2995
		2996	Supported event modules: L<AnyEvent::Loop>, L<EV>, L<EV::Glib>,
		2997	L<Glib::EV>, L<Event>, L<Glib::Event>, L<Glib>, L<Tk>, L<Event::Lib>,
		2998	L<Qt>, L<POE>, L<FLTK>.
2633		2999
2634	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,	3000	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,
2635	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,	3001	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,
2636	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,	3002	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,
2637	L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>, L<Anyevent::Impl::Irssi>.	3003	L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>, L<Anyevent::Impl::Irssi>,
		3004	L<AnyEvent::Impl::FLTK>.
2638		3005
2639	Non-blocking file handles, sockets, TCP clients and	3006	Non-blocking handles, pipes, stream sockets, TCP clients and
2640	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.	3007	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.
2641		3008
2642	Asynchronous DNS: L<AnyEvent::DNS>.	3009	Asynchronous DNS: L<AnyEvent::DNS>.
2643		3010
2644	Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>,	3011	Thread support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>.
2645	L<Coro::Event>,
2646		3012
2647	Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::XMPP>,	3013	Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::IRC>,
2648	L<AnyEvent::HTTP>.	3014	L<AnyEvent::HTTP>.
2649		3015
2650		3016
2651	=head1 AUTHOR	3017	=head1 AUTHOR
2652		3018

Diff Legend

–	Removed lines
+	Added lines
<	Changed lines
>	Changed lines