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Revision 1.381 by root, Thu Sep 1 22:09:25 2011 UTC

1	=head1 NAME	1	=head1 NAME
2		2
3	AnyEvent - provide framework for multiple event loops	3	AnyEvent - the DBI of event loop programming
4		4
5	EV, Event, Glib, Tk, Perl, Event::Lib, Qt and POE are various supported	5	EV, Event, Glib, Tk, Perl, Event::Lib, Irssi, rxvt-unicode, IO::Async, Qt,
6	event loops.	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
…		…
40	=head1 INTRODUCTION/TUTORIAL	43	=head1 INTRODUCTION/TUTORIAL
41		44
42	This manpage is mainly a reference manual. If you are interested	45	This manpage is mainly a reference manual. If you are interested
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.
		48
		49	=head1 SUPPORT
		50
		51	An FAQ document is available as L<AnyEvent::FAQ>.
		52
		53	There also is a mailinglist for discussing all things AnyEvent, and an IRC
		54	channel, too.
		55
		56	See the AnyEvent project page at the B<Schmorpforge Ta-Sa Software
		57	Repository>, at L<http://anyevent.schmorp.de>, for more info.
45		58
46	=head1 WHY YOU SHOULD USE THIS MODULE (OR NOT)	59	=head1 WHY YOU SHOULD USE THIS MODULE (OR NOT)
47		60
48	Glib, POE, IO::Async, Event... CPAN offers event models by the dozen	61	Glib, POE, IO::Async, Event... CPAN offers event models by the dozen
49	nowadays. So what is different about AnyEvent?	62	nowadays. So what is different about AnyEvent?
…		…
65	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
66	model you use.	79	model you use.
67		80
68	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
69	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
70	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
71	cannot use anything else, as they are simply incompatible to everything	84	cannot use anything else, as they are simply incompatible to everything
72	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
73	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.
74		87
75	AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works	88	AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works
76	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
77	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
78	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
79	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
80	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
81	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,
82	to AnyEvent, too, so it is future-proof).	95	so it is future-proof).
83		96
84	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
85	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
86	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
87	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
88	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
89	technically possible.	102	technically possible.
90		103
91	Of course, AnyEvent comes with a big (and fully optional!) toolbox	104	Of course, AnyEvent comes with a big (and fully optional!) toolbox
92	of useful functionality, such as an asynchronous DNS resolver, 100%	105	of useful functionality, such as an asynchronous DNS resolver, 100%
…		…
98	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
99	model, you should I<not> use this module.	112	model, you should I<not> use this module.
100		113
101	=head1 DESCRIPTION	114	=head1 DESCRIPTION
102		115
103	L<AnyEvent> provides an identical interface to multiple event loops. This	116	L<AnyEvent> provides a uniform interface to various event loops. This
104	allows module authors to utilise an event loop without forcing module	117	allows module authors to use event loop functionality without forcing
105	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
106	peacefully at any one time).	119	than one event loop cannot coexist peacefully).
107		120
108	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>
109	module.	122	module.
110		123
111	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
112	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
113	following modules is already loaded: L<EV>,	126	following modules is already loaded: L<EV>, L<AnyEvent::Loop>,
114	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
115	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
116	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
117	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
118	be successfully loaded will be used. If, after this, still none could be	131	the other two are not normally tried.
119	found, AnyEvent will fall back to a pure-perl event loop, which is not
120	very efficient, but should work everywhere.
121		132
122	Because AnyEvent first checks for modules that are already loaded, loading	133	Because AnyEvent first checks for modules that are already loaded, loading
123	an event model explicitly before first using AnyEvent will likely make	134	an event model explicitly before first using AnyEvent will likely make
124	that model the default. For example:	135	that model the default. For example:
125		136
…		…
127	use AnyEvent;	138	use AnyEvent;
128		139
129	# .. AnyEvent will likely default to Tk	140	# .. AnyEvent will likely default to Tk
130		141
131	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
132	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,
133	use AnyEvent so their modules work together with others seamlessly...	144	as very few modules hardcode event loops without announcing this very
		145	loudly.
134		146
135	The pure-perl implementation of AnyEvent is called	147	The pure-perl implementation of AnyEvent is called C<AnyEvent::Loop>. Like
136	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
137	explicitly and enjoy the high availability of that event loop :)	149	availability of that event loop :)
138		150
139	=head1 WATCHERS	151	=head1 WATCHERS
140		152
141	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
142	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
…		…
147	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
148	is in control).	160	is in control).
149		161
150	Note that B<callbacks must not permanently change global variables>	162	Note that B<callbacks must not permanently change global variables>
151	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<<
152	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
153	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
154	widely between event loops.	166	widely between event loops.
155		167
156	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
157	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
158	to it).	170	to it).
159		171
160	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.
161		173
162	Many watchers either are used with "recursion" (repeating timers for	174	Many watchers either are used with "recursion" (repeating timers for
163	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.
164		176
165	An any way to achieve that is this pattern:	177	One way to achieve that is this pattern:
166		178
167	my $w; $w = AnyEvent->type (arg => value ..., cb => sub {	179	my $w; $w = AnyEvent->type (arg => value ..., cb => sub {
168	# you can use $w here, for example to undef it	180	# you can use $w here, for example to undef it
169	undef $w;	181	undef $w;
170	});	182	});
…		…
172	Note that C<my $w; $w => combination. This is necessary because in Perl,	184	Note that C<my $w; $w => combination. This is necessary because in Perl,
173	my variables are only visible after the statement in which they are	185	my variables are only visible after the statement in which they are
174	declared.	186	declared.
175		187
176	=head2 I/O WATCHERS	188	=head2 I/O WATCHERS
		189
		190	$w = AnyEvent->io (
		191	fh => <filehandle_or_fileno>,
		192	poll => <"r" or "w">,
		193	cb => <callback>,
		194	);
177		195
178	You can create an I/O watcher by calling the C<< AnyEvent->io >> method	196	You can create an I/O watcher by calling the C<< AnyEvent->io >> method
179	with the following mandatory key-value pairs as arguments:	197	with the following mandatory key-value pairs as arguments:
180		198
181	C<fh> is the Perl I<file handle> (or a naked file descriptor) to watch	199	C<fh> is the Perl I<file handle> (or a naked file descriptor) to watch
…		…
196		214
197	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.
198	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
199	underlying file descriptor.	217	underlying file descriptor.
200		218
201	Some event loops issue spurious readyness notifications, so you should	219	Some event loops issue spurious readiness notifications, so you should
202	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
203	handles.	221	handles.
204		222
205	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
206	watcher.	224	watcher.
…		…
211	undef $w;	229	undef $w;
212	});	230	});
213		231
214	=head2 TIME WATCHERS	232	=head2 TIME WATCHERS
215		233
		234	$w = AnyEvent->timer (after => <seconds>, cb => <callback>);
		235
		236	$w = AnyEvent->timer (
		237	after => <fractional_seconds>,
		238	interval => <fractional_seconds>,
		239	cb => <callback>,
		240	);
		241
216	You can create a time watcher by calling the C<< AnyEvent->timer >>	242	You can create a time watcher by calling the C<< AnyEvent->timer >>
217	method with the following mandatory arguments:	243	method with the following mandatory arguments:
218		244
219	C<after> specifies after how many seconds (fractional values are	245	C<after> specifies after how many seconds (fractional values are
220	supported) the callback should be invoked. C<cb> is the callback to invoke	246	supported) the callback should be invoked. C<cb> is the callback to invoke
…		…
222		248
223	Although the callback might get passed parameters, their value and	249	Although the callback might get passed parameters, their value and
224	presence is undefined and you cannot rely on them. Portable AnyEvent	250	presence is undefined and you cannot rely on them. Portable AnyEvent
225	callbacks cannot use arguments passed to time watcher callbacks.	251	callbacks cannot use arguments passed to time watcher callbacks.
226		252
227	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
228	parameter, C<interval>, as a strictly positive number (> 0), then the	254	parameter, C<interval>, as a strictly positive number (> 0), then the
229	callback will be invoked regularly at that interval (in fractional	255	callback will be invoked regularly at that interval (in fractional
230	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
231	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.
232		258
233	The callback will be rescheduled before invoking the callback, but no	259	The callback will be rescheduled before invoking the callback, but no
234	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
235	only approximate.	261	only approximate.
236		262
237	Example: fire an event after 7.7 seconds.	263	Example: fire an event after 7.7 seconds.
238		264
239	my $w = AnyEvent->timer (after => 7.7, cb => sub {	265	my $w = AnyEvent->timer (after => 7.7, cb => sub {
…		…
257		283
258	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
259	use absolute time internally. This makes a difference when your clock	285	use absolute time internally. This makes a difference when your clock
260	"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
261	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
262	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.
263		289
264	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
265	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
266	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)
267	timers.	293	timers.
268		294
269	AnyEvent always prefers relative timers, if available, matching the	295	AnyEvent always prefers relative timers, if available, matching the
270	AnyEvent API.	296	AnyEvent API.
…		…
292	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
293	function to call when you want to know the current time.>	319	function to call when you want to know the current time.>
294		320
295	This function is also often faster then C<< AnyEvent->time >>, and	321	This function is also often faster then C<< AnyEvent->time >>, and
296	thus the preferred method if you want some timestamp (for example,	322	thus the preferred method if you want some timestamp (for example,
297	L<AnyEvent::Handle> uses this to update it's activity timeouts).	323	L<AnyEvent::Handle> uses this to update its activity timeouts).
298		324
299	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
300	with your timing, you can skip it without bad conscience.	326	with your timing; you can skip it without a bad conscience.
301		327
302	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>
303	and L<EV> and the following set-up:	329	and L<EV> and the following set-up:
304		330
305	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
306	time=500 (assume no other callbacks delay processing). In your callback,	332	time=500 (assume no other callbacks delay processing). In your callback,
307	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
308	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
309	after three seconds.	335	after three seconds.
310		336
…		…
330	difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into	356	difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into
331	account.	357	account.
332		358
333	=item AnyEvent->now_update	359	=item AnyEvent->now_update
334		360
335	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
336	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 >>,
337	AnyEvent->now >>, above).	363	above).
338		364
339	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
340	this "current" time will differ substantially from the real time, which	366	this "current" time will differ substantially from the real time, which
341	might affect timers and time-outs.	367	might affect timers and time-outs.
342		368
343	When this is the case, you can call this method, which will update the	369	When this is the case, you can call this method, which will update the
344	event loop's idea of "current time".	370	event loop's idea of "current time".
345		371
		372	A typical example would be a script in a web server (e.g. C<mod_perl>) -
		373	when mod_perl executes the script, then the event loop will have the wrong
		374	idea about the "current time" (being potentially far in the past, when the
		375	script ran the last time). In that case you should arrange a call to C<<
		376	AnyEvent->now_update >> each time the web server process wakes up again
		377	(e.g. at the start of your script, or in a handler).
		378
346	Note that updating the time I<might> cause some events to be handled.	379	Note that updating the time I<might> cause some events to be handled.
347		380
348	=back	381	=back
349		382
350	=head2 SIGNAL WATCHERS	383	=head2 SIGNAL WATCHERS
		384
		385	$w = AnyEvent->signal (signal => <uppercase_signal_name>, cb => <callback>);
351		386
352	You can watch for signals using a signal watcher, C<signal> is the signal	387	You can watch for signals using a signal watcher, C<signal> is the signal
353	I<name> in uppercase and without any C<SIG> prefix, C<cb> is the Perl	388	I<name> in uppercase and without any C<SIG> prefix, C<cb> is the Perl
354	callback to be invoked whenever a signal occurs.	389	callback to be invoked whenever a signal occurs.
355		390
…		…
368		403
369	This watcher might use C<%SIG> (depending on the event loop used),	404	This watcher might use C<%SIG> (depending on the event loop used),
370	so programs overwriting those signals directly will likely not work	405	so programs overwriting those signals directly will likely not work
371	correctly.	406	correctly.
372		407
		408	Example: exit on SIGINT
		409
		410	my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });
		411
		412	=head3 Restart Behaviour
		413
		414	While restart behaviour is up to the event loop implementation, most will
		415	not restart syscalls (that includes L<Async::Interrupt> and AnyEvent's
		416	pure perl implementation).
		417
		418	=head3 Safe/Unsafe Signals
		419
		420	Perl signals can be either "safe" (synchronous to opcode handling) or
		421	"unsafe" (asynchronous) - the former might get delayed indefinitely, the
		422	latter might corrupt your memory.
		423
		424	AnyEvent signal handlers are, in addition, synchronous to the event loop,
		425	i.e. they will not interrupt your running perl program but will only be
		426	called as part of the normal event handling (just like timer, I/O etc.
		427	callbacks, too).
		428
		429	=head3 Signal Races, Delays and Workarounds
		430
373	Also note that many event loops (e.g. Glib, Tk, Qt, IO::Async) do not	431	Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support attaching
374	support attaching callbacks to signals, which is a pity, as you cannot do	432	callbacks to signals in a generic way, which is a pity, as you cannot
375	race-free signal handling in perl. AnyEvent will try to do it's best, but	433	do race-free signal handling in perl, requiring C libraries for
		434	this. AnyEvent will try to do its best, which means in some cases,
376	in some cases, signals will be delayed. The maximum time a signal might	435	signals will be delayed. The maximum time a signal might be delayed is
377	be delayed is specified in C<$AnyEvent::MAX_SIGNAL_LATENCY> (default: 10	436	specified in C<$AnyEvent::MAX_SIGNAL_LATENCY> (default: 10 seconds). This
378	seconds). This variable can be changed only before the first signal	437	variable can be changed only before the first signal watcher is created,
379	watcher is created, and should be left alone otherwise. Higher values	438	and should be left alone otherwise. This variable determines how often
		439	AnyEvent polls for signals (in case a wake-up was missed). Higher values
380	will cause fewer spurious wake-ups, which is better for power and CPU	440	will cause fewer spurious wake-ups, which is better for power and CPU
		441	saving.
		442
381	saving. All these problems can be avoided by installing the optional	443	All these problems can be avoided by installing the optional
382	L<Async::Interrupt> module.	444	L<Async::Interrupt> module, which works with most event loops. It will not
383		445	work with inherently broken event loops such as L<Event> or L<Event::Lib>
384	Example: exit on SIGINT	446	(and not with L<POE> currently, as POE does its own workaround with
385		447	one-second latency). For those, you just have to suffer the delays.
386	my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });
387		448
388	=head2 CHILD PROCESS WATCHERS	449	=head2 CHILD PROCESS WATCHERS
389		450
		451	$w = AnyEvent->child (pid => <process id>, cb => <callback>);
		452
390	You can also watch on a child process exit and catch its exit status.	453	You can also watch for a child process exit and catch its exit status.
391		454
392	The child process is specified by the C<pid> argument (if set to C<0>, it	455	The child process is specified by the C<pid> argument (on some backends,
393	watches for any child process exit). The watcher will triggered only when	456	using C<0> watches for any child process exit, on others this will
394	the child process has finished and an exit status is available, not on	457	croak). The watcher will be triggered only when the child process has
395	any trace events (stopped/continued).	458	finished and an exit status is available, not on any trace events
		459	(stopped/continued).
396		460
397	The callback will be called with the pid and exit status (as returned by	461	The callback will be called with the pid and exit status (as returned by
398	waitpid), so unlike other watcher types, you I<can> rely on child watcher	462	waitpid), so unlike other watcher types, you I<can> rely on child watcher
399	callback arguments.	463	callback arguments.
400		464
…		…
418	thing in an AnyEvent program, you I<have> to create at least one	482	thing in an AnyEvent program, you I<have> to create at least one
419	watcher before you C<fork> the child (alternatively, you can call	483	watcher before you C<fork> the child (alternatively, you can call
420	C<AnyEvent::detect>).	484	C<AnyEvent::detect>).
421		485
422	As most event loops do not support waiting for child events, they will be	486	As most event loops do not support waiting for child events, they will be
423	emulated by AnyEvent in most cases, in which the latency and race problems	487	emulated by AnyEvent in most cases, in which case the latency and race
424	mentioned in the description of signal watchers apply.	488	problems mentioned in the description of signal watchers apply.
425		489
426	Example: fork a process and wait for it	490	Example: fork a process and wait for it
427		491
428	my $done = AnyEvent->condvar;	492	my $done = AnyEvent->condvar;
429		493
…		…
441	# do something else, then wait for process exit	505	# do something else, then wait for process exit
442	$done->recv;	506	$done->recv;
443		507
444	=head2 IDLE WATCHERS	508	=head2 IDLE WATCHERS
445		509
446	Sometimes there is a need to do something, but it is not so important	510	$w = AnyEvent->idle (cb => <callback>);
447	to do it instantly, but only when there is nothing better to do. This
448	"nothing better to do" is usually defined to be "no other events need
449	attention by the event loop".
450		511
451	Idle watchers ideally get invoked when the event loop has nothing	512	This will repeatedly invoke the callback after the process becomes idle,
452	better to do, just before it would block the process to wait for new	513	until either the watcher is destroyed or new events have been detected.
453	events. Instead of blocking, the idle watcher is invoked.
454		514
455	Most event loops unfortunately do not really support idle watchers (only	515	Idle watchers are useful when there is a need to do something, but it
		516	is not so important (or wise) to do it instantly. The callback will be
		517	invoked only when there is "nothing better to do", which is usually
		518	defined as "all outstanding events have been handled and no new events
		519	have been detected". That means that idle watchers ideally get invoked
		520	when the event loop has just polled for new events but none have been
		521	detected. Instead of blocking to wait for more events, the idle watchers
		522	will be invoked.
		523
		524	Unfortunately, most event loops do not really support idle watchers (only
456	EV, Event and Glib do it in a usable fashion) - for the rest, AnyEvent	525	EV, Event and Glib do it in a usable fashion) - for the rest, AnyEvent
457	will simply call the callback "from time to time".	526	will simply call the callback "from time to time".
458		527
459	Example: read lines from STDIN, but only process them when the	528	Example: read lines from STDIN, but only process them when the
460	program is otherwise idle:	529	program is otherwise idle:
…		…
476	});	545	});
477	});	546	});
478		547
479	=head2 CONDITION VARIABLES	548	=head2 CONDITION VARIABLES
480		549
		550	$cv = AnyEvent->condvar;
		551
		552	$cv->send (<list>);
		553	my @res = $cv->recv;
		554
481	If you are familiar with some event loops you will know that all of them	555	If you are familiar with some event loops you will know that all of them
482	require you to run some blocking "loop", "run" or similar function that	556	require you to run some blocking "loop", "run" or similar function that
483	will actively watch for new events and call your callbacks.	557	will actively watch for new events and call your callbacks.
484		558
485	AnyEvent is slightly different: it expects somebody else to run the event	559	AnyEvent is slightly different: it expects somebody else to run the event
486	loop and will only block when necessary (usually when told by the user).	560	loop and will only block when necessary (usually when told by the user).
487		561
488	The instrument to do that is called a "condition variable", so called	562	The tool to do that is called a "condition variable", so called because
489	because they represent a condition that must become true.	563	they represent a condition that must become true.
490		564
491	Now is probably a good time to look at the examples further below.	565	Now is probably a good time to look at the examples further below.
492		566
493	Condition variables can be created by calling the C<< AnyEvent->condvar	567	Condition variables can be created by calling the C<< AnyEvent->condvar
494	>> method, usually without arguments. The only argument pair allowed is	568	>> method, usually without arguments. The only argument pair allowed is
…		…
499	After creation, the condition variable is "false" until it becomes "true"	573	After creation, the condition variable is "false" until it becomes "true"
500	by calling the C<send> method (or calling the condition variable as if it	574	by calling the C<send> method (or calling the condition variable as if it
501	were a callback, read about the caveats in the description for the C<<	575	were a callback, read about the caveats in the description for the C<<
502	->send >> method).	576	->send >> method).
503		577
504	Condition variables are similar to callbacks, except that you can	578	Since condition variables are the most complex part of the AnyEvent API, here are
505	optionally wait for them. They can also be called merge points - points	579	some different mental models of what they are - pick the ones you can connect to:
506	in time where multiple outstanding events have been processed. And yet	580
507	another way to call them is transactions - each condition variable can be	581	=over 4
508	used to represent a transaction, which finishes at some point and delivers	582
509	a result.	583	=item * Condition variables are like callbacks - you can call them (and pass them instead
		584	of callbacks). Unlike callbacks however, you can also wait for them to be called.
		585
		586	=item * Condition variables are signals - one side can emit or send them,
		587	the other side can wait for them, or install a handler that is called when
		588	the signal fires.
		589
		590	=item * Condition variables are like "Merge Points" - points in your program
		591	where you merge multiple independent results/control flows into one.
		592
		593	=item * Condition variables represent a transaction - functions that start
		594	some kind of transaction can return them, leaving the caller the choice
		595	between waiting in a blocking fashion, or setting a callback.
		596
		597	=item * Condition variables represent future values, or promises to deliver
		598	some result, long before the result is available.
		599
		600	=back
510		601
511	Condition variables are very useful to signal that something has finished,	602	Condition variables are very useful to signal that something has finished,
512	for example, if you write a module that does asynchronous http requests,	603	for example, if you write a module that does asynchronous http requests,
513	then a condition variable would be the ideal candidate to signal the	604	then a condition variable would be the ideal candidate to signal the
514	availability of results. The user can either act when the callback is	605	availability of results. The user can either act when the callback is
…		…
527		618
528	Condition variables are represented by hash refs in perl, and the keys	619	Condition variables are represented by hash refs in perl, and the keys
529	used by AnyEvent itself are all named C<_ae_XXX> to make subclassing	620	used by AnyEvent itself are all named C<_ae_XXX> to make subclassing
530	easy (it is often useful to build your own transaction class on top of	621	easy (it is often useful to build your own transaction class on top of
531	AnyEvent). To subclass, use C<AnyEvent::CondVar> as base class and call	622	AnyEvent). To subclass, use C<AnyEvent::CondVar> as base class and call
532	it's C<new> method in your own C<new> method.	623	its C<new> method in your own C<new> method.
533		624
534	There are two "sides" to a condition variable - the "producer side" which	625	There are two "sides" to a condition variable - the "producer side" which
535	eventually calls C<< -> send >>, and the "consumer side", which waits	626	eventually calls C<< -> send >>, and the "consumer side", which waits
536	for the send to occur.	627	for the send to occur.
537		628
538	Example: wait for a timer.	629	Example: wait for a timer.
539		630
540	# wait till the result is ready	631	# condition: "wait till the timer is fired"
541	my $result_ready = AnyEvent->condvar;	632	my $timer_fired = AnyEvent->condvar;
542		633
543	# do something such as adding a timer	634	# create the timer - we could wait for, say
544	# or socket watcher the calls $result_ready->send	635	# a handle becomign ready, or even an
545	# when the "result" is ready.	636	# AnyEvent::HTTP request to finish, but
546	# in this case, we simply use a timer:	637	# in this case, we simply use a timer:
547	my $w = AnyEvent->timer (	638	my $w = AnyEvent->timer (
548	after => 1,	639	after => 1,
549	cb => sub { $result_ready->send },	640	cb => sub { $timer_fired->send },
550	);	641	);
551		642
552	# this "blocks" (while handling events) till the callback	643	# this "blocks" (while handling events) till the callback
553	# calls -<send	644	# calls ->send
554	$result_ready->recv;	645	$timer_fired->recv;
555		646
556	Example: wait for a timer, but take advantage of the fact that condition	647	Example: wait for a timer, but take advantage of the fact that condition
557	variables are also callable directly.	648	variables are also callable directly.
558		649
559	my $done = AnyEvent->condvar;	650	my $done = AnyEvent->condvar;
…		…
602	they were a code reference). Calling them directly is the same as calling	693	they were a code reference). Calling them directly is the same as calling
603	C<send>.	694	C<send>.
604		695
605	=item $cv->croak ($error)	696	=item $cv->croak ($error)
606		697
607	Similar to send, but causes all call's to C<< ->recv >> to invoke	698	Similar to send, but causes all calls to C<< ->recv >> to invoke
608	C<Carp::croak> with the given error message/object/scalar.	699	C<Carp::croak> with the given error message/object/scalar.
609		700
610	This can be used to signal any errors to the condition variable	701	This can be used to signal any errors to the condition variable
611	user/consumer. Doing it this way instead of calling C<croak> directly	702	user/consumer. Doing it this way instead of calling C<croak> directly
612	delays the error detetcion, but has the overwhelmign advantage that it	703	delays the error detection, but has the overwhelming advantage that it
613	diagnoses the error at the place where the result is expected, and not	704	diagnoses the error at the place where the result is expected, and not
614	deep in some event clalback without connection to the actual code causing	705	deep in some event callback with no connection to the actual code causing
615	the problem.	706	the problem.
616		707
617	=item $cv->begin ([group callback])	708	=item $cv->begin ([group callback])
618		709
619	=item $cv->end	710	=item $cv->end
…		…
622	one. For example, a function that pings many hosts in parallel might want	713	one. For example, a function that pings many hosts in parallel might want
623	to use a condition variable for the whole process.	714	to use a condition variable for the whole process.
624		715
625	Every call to C<< ->begin >> will increment a counter, and every call to	716	Every call to C<< ->begin >> will increment a counter, and every call to
626	C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end	717	C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end
627	>>, the (last) callback passed to C<begin> will be executed. That callback	718	>>, the (last) callback passed to C<begin> will be executed, passing the
628	is I<supposed> to call C<< ->send >>, but that is not required. If no	719	condvar as first argument. That callback is I<supposed> to call C<< ->send
629	callback was set, C<send> will be called without any arguments.	720	>>, but that is not required. If no group callback was set, C<send> will
		721	be called without any arguments.
630		722
631	You can think of C<< $cv->send >> giving you an OR condition (one call	723	You can think of C<< $cv->send >> giving you an OR condition (one call
632	sends), while C<< $cv->begin >> and C<< $cv->end >> giving you an AND	724	sends), while C<< $cv->begin >> and C<< $cv->end >> giving you an AND
633	condition (all C<begin> calls must be C<end>'ed before the condvar sends).	725	condition (all C<begin> calls must be C<end>'ed before the condvar sends).
634		726
…		…
656	one call to C<begin>, so the condvar waits for all calls to C<end> before	748	one call to C<begin>, so the condvar waits for all calls to C<end> before
657	sending.	749	sending.
658		750
659	The ping example mentioned above is slightly more complicated, as the	751	The ping example mentioned above is slightly more complicated, as the
660	there are results to be passwd back, and the number of tasks that are	752	there are results to be passwd back, and the number of tasks that are
661	begung can potentially be zero:	753	begun can potentially be zero:
662		754
663	my $cv = AnyEvent->condvar;	755	my $cv = AnyEvent->condvar;
664		756
665	my %result;	757	my %result;
666	$cv->begin (sub { $cv->send (\%result) });	758	$cv->begin (sub { shift->send (\%result) });
667		759
668	for my $host (@list_of_hosts) {	760	for my $host (@list_of_hosts) {
669	$cv->begin;	761	$cv->begin;
670	ping_host_then_call_callback $host, sub {	762	ping_host_then_call_callback $host, sub {
671	$result{$host} = ...;	763	$result{$host} = ...;
…		…
687	to be called once the counter reaches C<0>, and second, it ensures that	779	to be called once the counter reaches C<0>, and second, it ensures that
688	C<send> is called even when C<no> hosts are being pinged (the loop	780	C<send> is called even when C<no> hosts are being pinged (the loop
689	doesn't execute once).	781	doesn't execute once).
690		782
691	This is the general pattern when you "fan out" into multiple (but	783	This is the general pattern when you "fan out" into multiple (but
692	potentially none) subrequests: use an outer C<begin>/C<end> pair to set	784	potentially zero) subrequests: use an outer C<begin>/C<end> pair to set
693	the callback and ensure C<end> is called at least once, and then, for each	785	the callback and ensure C<end> is called at least once, and then, for each
694	subrequest you start, call C<begin> and for each subrequest you finish,	786	subrequest you start, call C<begin> and for each subrequest you finish,
695	call C<end>.	787	call C<end>.
696		788
697	=back	789	=back
…		…
704	=over 4	796	=over 4
705		797
706	=item $cv->recv	798	=item $cv->recv
707		799
708	Wait (blocking if necessary) until the C<< ->send >> or C<< ->croak	800	Wait (blocking if necessary) until the C<< ->send >> or C<< ->croak
709	>> methods have been called on c<$cv>, while servicing other watchers	801	>> methods have been called on C<$cv>, while servicing other watchers
710	normally.	802	normally.
711		803
712	You can only wait once on a condition - additional calls are valid but	804	You can only wait once on a condition - additional calls are valid but
713	will return immediately.	805	will return immediately.
714		806
…		…
731	caller decide whether the call will block or not (for example, by coupling	823	caller decide whether the call will block or not (for example, by coupling
732	condition variables with some kind of request results and supporting	824	condition variables with some kind of request results and supporting
733	callbacks so the caller knows that getting the result will not block,	825	callbacks so the caller knows that getting the result will not block,
734	while still supporting blocking waits if the caller so desires).	826	while still supporting blocking waits if the caller so desires).
735		827
736	You can ensure that C<< -recv >> never blocks by setting a callback and	828	You can ensure that C<< ->recv >> never blocks by setting a callback and
737	only calling C<< ->recv >> from within that callback (or at a later	829	only calling C<< ->recv >> from within that callback (or at a later
738	time). This will work even when the event loop does not support blocking	830	time). This will work even when the event loop does not support blocking
739	waits otherwise.	831	waits otherwise.
740		832
741	=item $bool = $cv->ready	833	=item $bool = $cv->ready
…		…
747		839
748	This is a mutator function that returns the callback set and optionally	840	This is a mutator function that returns the callback set and optionally
749	replaces it before doing so.	841	replaces it before doing so.
750		842
751	The callback will be called when the condition becomes "true", i.e. when	843	The callback will be called when the condition becomes "true", i.e. when
752	C<send> or C<croak> are called, with the only argument being the condition	844	C<send> or C<croak> are called, with the only argument being the
753	variable itself. Calling C<recv> inside the callback or at any later time	845	condition variable itself. If the condition is already true, the
754	is guaranteed not to block.	846	callback is called immediately when it is set. Calling C<recv> inside
		847	the callback or at any later time is guaranteed not to block.
755		848
756	=back	849	=back
757		850
758	=head1 SUPPORTED EVENT LOOPS/BACKENDS	851	=head1 SUPPORTED EVENT LOOPS/BACKENDS
759		852
…		…
762	=over 4	855	=over 4
763		856
764	=item Backends that are autoprobed when no other event loop can be found.	857	=item Backends that are autoprobed when no other event loop can be found.
765		858
766	EV is the preferred backend when no other event loop seems to be in	859	EV is the preferred backend when no other event loop seems to be in
767	use. If EV is not installed, then AnyEvent will try Event, and, failing	860	use. If EV is not installed, then AnyEvent will fall back to its own
768	that, will fall back to its own pure-perl implementation, which is	861	pure-perl implementation, which is available everywhere as it comes with
769	available everywhere as it comes with AnyEvent itself.	862	AnyEvent itself.
770		863
771	AnyEvent::Impl::EV based on EV (interface to libev, best choice).	864	AnyEvent::Impl::EV based on EV (interface to libev, best choice).
772	AnyEvent::Impl::Event based on Event, very stable, few glitches.
773	AnyEvent::Impl::Perl pure-perl implementation, fast and portable.	865	AnyEvent::Impl::Perl pure-perl AnyEvent::Loop, fast and portable.
774		866
775	=item Backends that are transparently being picked up when they are used.	867	=item Backends that are transparently being picked up when they are used.
776		868
777	These will be used when they are currently loaded when the first watcher	869	These will be used if they are already loaded when the first watcher
778	is created, in which case it is assumed that the application is using	870	is created, in which case it is assumed that the application is using
779	them. This means that AnyEvent will automatically pick the right backend	871	them. This means that AnyEvent will automatically pick the right backend
780	when the main program loads an event module before anything starts to	872	when the main program loads an event module before anything starts to
781	create watchers. Nothing special needs to be done by the main program.	873	create watchers. Nothing special needs to be done by the main program.
782		874
		875	AnyEvent::Impl::Event based on Event, very stable, few glitches.
783	AnyEvent::Impl::Glib based on Glib, slow but very stable.	876	AnyEvent::Impl::Glib based on Glib, slow but very stable.
784	AnyEvent::Impl::Tk based on Tk, very broken.	877	AnyEvent::Impl::Tk based on Tk, very broken.
785	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.	878	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
786	AnyEvent::Impl::POE based on POE, very slow, some limitations.	879	AnyEvent::Impl::POE based on POE, very slow, some limitations.
		880	AnyEvent::Impl::Irssi used when running within irssi.
		881	AnyEvent::Impl::IOAsync based on IO::Async.
		882	AnyEvent::Impl::Cocoa based on Cocoa::EventLoop.
		883	AnyEvent::Impl::FLTK based on FLTK (fltk 2 binding).
787		884
788	=item Backends with special needs.	885	=item Backends with special needs.
789		886
790	Qt requires the Qt::Application to be instantiated first, but will	887	Qt requires the Qt::Application to be instantiated first, but will
791	otherwise be picked up automatically. As long as the main program	888	otherwise be picked up automatically. As long as the main program
792	instantiates the application before any AnyEvent watchers are created,	889	instantiates the application before any AnyEvent watchers are created,
793	everything should just work.	890	everything should just work.
794		891
795	AnyEvent::Impl::Qt based on Qt.	892	AnyEvent::Impl::Qt based on Qt.
796		893
797	Support for IO::Async can only be partial, as it is too broken and
798	architecturally limited to even support the AnyEvent API. It also
799	is the only event loop that needs the loop to be set explicitly, so
800	it can only be used by a main program knowing about AnyEvent. See
801	L<AnyEvent::Impl::Async> for the gory details.
802
803	AnyEvent::Impl::IOAsync based on IO::Async, cannot be autoprobed.
804
805	=item Event loops that are indirectly supported via other backends.	894	=item Event loops that are indirectly supported via other backends.
806		895
807	Some event loops can be supported via other modules:	896	Some event loops can be supported via other modules:
808		897
809	There is no direct support for WxWidgets (L<Wx>) or L<Prima>.	898	There is no direct support for WxWidgets (L<Wx>) or L<Prima>.
…		…
834	Contains C<undef> until the first watcher is being created, before the	923	Contains C<undef> until the first watcher is being created, before the
835	backend has been autodetected.	924	backend has been autodetected.
836		925
837	Afterwards it contains the event model that is being used, which is the	926	Afterwards it contains the event model that is being used, which is the
838	name of the Perl class implementing the model. This class is usually one	927	name of the Perl class implementing the model. This class is usually one
839	of the C<AnyEvent::Impl:xxx> modules, but can be any other class in the	928	of the C<AnyEvent::Impl::xxx> modules, but can be any other class in the
840	case AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode> it	929	case AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode> it
841	will be C<urxvt::anyevent>).	930	will be C<urxvt::anyevent>).
842		931
843	=item AnyEvent::detect	932	=item AnyEvent::detect
844		933
845	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model	934	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model
846	if necessary. You should only call this function right before you would	935	if necessary. You should only call this function right before you would
847	have created an AnyEvent watcher anyway, that is, as late as possible at	936	have created an AnyEvent watcher anyway, that is, as late as possible at
848	runtime, and not e.g. while initialising of your module.	937	runtime, and not e.g. during initialisation of your module.
		938
		939	The effect of calling this function is as if a watcher had been created
		940	(specifically, actions that happen "when the first watcher is created"
		941	happen when calling detetc as well).
849		942
850	If you need to do some initialisation before AnyEvent watchers are	943	If you need to do some initialisation before AnyEvent watchers are
851	created, use C<post_detect>.	944	created, use C<post_detect>.
852		945
853	=item $guard = AnyEvent::post_detect { BLOCK }	946	=item $guard = AnyEvent::post_detect { BLOCK }
854		947
855	Arranges for the code block to be executed as soon as the event model is	948	Arranges for the code block to be executed as soon as the event model is
856	autodetected (or immediately if this has already happened).	949	autodetected (or immediately if that has already happened).
857		950
858	The block will be executed I<after> the actual backend has been detected	951	The block will be executed I<after> the actual backend has been detected
859	(C<$AnyEvent::MODEL> is set), but I<before> any watchers have been	952	(C<$AnyEvent::MODEL> is set), but I<before> any watchers have been
860	created, so it is possible to e.g. patch C<@AnyEvent::ISA> or do	953	created, so it is possible to e.g. patch C<@AnyEvent::ISA> or do
861	other initialisations - see the sources of L<AnyEvent::Strict> or	954	other initialisations - see the sources of L<AnyEvent::Strict> or
…		…
865	event module detection too early, for example, L<AnyEvent::AIO> creates	958	event module detection too early, for example, L<AnyEvent::AIO> creates
866	and installs the global L<IO::AIO> watcher in a C<post_detect> block to	959	and installs the global L<IO::AIO> watcher in a C<post_detect> block to
867	avoid autodetecting the event module at load time.	960	avoid autodetecting the event module at load time.
868		961
869	If called in scalar or list context, then it creates and returns an object	962	If called in scalar or list context, then it creates and returns an object
870	that automatically removes the callback again when it is destroyed. See	963	that automatically removes the callback again when it is destroyed (or
		964	C<undef> when the hook was immediately executed). See L<AnyEvent::AIO> for
871	L<Coro::BDB> for a case where this is useful.	965	a case where this is useful.
		966
		967	Example: Create a watcher for the IO::AIO module and store it in
		968	C<$WATCHER>, but do so only do so after the event loop is initialised.
		969
		970	our WATCHER;
		971
		972	my $guard = AnyEvent::post_detect {
		973	$WATCHER = AnyEvent->io (fh => IO::AIO::poll_fileno, poll => 'r', cb => \&IO::AIO::poll_cb);
		974	};
		975
		976	# the ||= is important in case post_detect immediately runs the block,
		977	# as to not clobber the newly-created watcher. assigning both watcher and
		978	# post_detect guard to the same variable has the advantage of users being
		979	# able to just C<undef $WATCHER> if the watcher causes them grief.
		980
		981	$WATCHER ||= $guard;
872		982
873	=item @AnyEvent::post_detect	983	=item @AnyEvent::post_detect
874		984
875	If there are any code references in this array (you can C<push> to it	985	If there are any code references in this array (you can C<push> to it
876	before or after loading AnyEvent), then they will called directly after	986	before or after loading AnyEvent), then they will be called directly
877	the event loop has been chosen.	987	after the event loop has been chosen.
878		988
879	You should check C<$AnyEvent::MODEL> before adding to this array, though:	989	You should check C<$AnyEvent::MODEL> before adding to this array, though:
880	if it is defined then the event loop has already been detected, and the	990	if it is defined then the event loop has already been detected, and the
881	array will be ignored.	991	array will be ignored.
882		992
883	Best use C<AnyEvent::post_detect { BLOCK }> when your application allows	993	Best use C<AnyEvent::post_detect { BLOCK }> when your application allows
884	it,as it takes care of these details.	994	it, as it takes care of these details.
885		995
886	This variable is mainly useful for modules that can do something useful	996	This variable is mainly useful for modules that can do something useful
887	when AnyEvent is used and thus want to know when it is initialised, but do	997	when AnyEvent is used and thus want to know when it is initialised, but do
888	not need to even load it by default. This array provides the means to hook	998	not need to even load it by default. This array provides the means to hook
889	into AnyEvent passively, without loading it.	999	into AnyEvent passively, without loading it.
890		1000
		1001	Example: To load Coro::AnyEvent whenever Coro and AnyEvent are used
		1002	together, you could put this into Coro (this is the actual code used by
		1003	Coro to accomplish this):
		1004
		1005	if (defined $AnyEvent::MODEL) {
		1006	# AnyEvent already initialised, so load Coro::AnyEvent
		1007	require Coro::AnyEvent;
		1008	} else {
		1009	# AnyEvent not yet initialised, so make sure to load Coro::AnyEvent
		1010	# as soon as it is
		1011	push @AnyEvent::post_detect, sub { require Coro::AnyEvent };
		1012	}
		1013
		1014	=item AnyEvent::postpone { BLOCK }
		1015
		1016	Arranges for the block to be executed as soon as possible, but not before
		1017	the call itself returns. In practise, the block will be executed just
		1018	before the event loop polls for new events, or shortly afterwards.
		1019
		1020	This function never returns anything (to make the C<return postpone { ...
		1021	}> idiom more useful.
		1022
		1023	To understand the usefulness of this function, consider a function that
		1024	asynchronously does something for you and returns some transaction
		1025	object or guard to let you cancel the operation. For example,
		1026	C<AnyEvent::Socket::tcp_connect>:
		1027
		1028	# start a conenction attempt unless one is active
		1029	$self->{connect_guard} ||= AnyEvent::Socket::tcp_connect "www.example.net", 80, sub {
		1030	delete $self->{connect_guard};
		1031	...
		1032	};
		1033
		1034	Imagine that this function could instantly call the callback, for
		1035	example, because it detects an obvious error such as a negative port
		1036	number. Invoking the callback before the function returns causes problems
		1037	however: the callback will be called and will try to delete the guard
		1038	object. But since the function hasn't returned yet, there is nothing to
		1039	delete. When the function eventually returns it will assign the guard
		1040	object to C<< $self->{connect_guard} >>, where it will likely never be
		1041	deleted, so the program thinks it is still trying to connect.
		1042
		1043	This is where C<AnyEvent::postpone> should be used. Instead of calling the
		1044	callback directly on error:
		1045
		1046	$cb->(undef), return # signal error to callback, BAD!
		1047	if $some_error_condition;
		1048
		1049	It should use C<postpone>:
		1050
		1051	AnyEvent::postpone { $cb->(undef) }, return # signal error to callback, later
		1052	if $some_error_condition;
		1053
		1054	=item AnyEvent::log $level, $msg[, @args]
		1055
		1056	Log the given C<$msg> at the given C<$level>.
		1057
		1058	If L<AnyEvent::Log> is not loaded then this function makes a simple test
		1059	to see whether the message will be logged. If the test succeeds it will
		1060	load AnyEvent::Log and call C<AnyEvent::Log::log> - consequently, look at
		1061	the L<AnyEvent::Log> documentation for details.
		1062
		1063	If the test fails it will simply return. Right now this happens when a
		1064	numerical loglevel is used and it is larger than the level specified via
		1065	C<$ENV{PERL_ANYEVENT_VERBOSE}>.
		1066
		1067	If you want to sprinkle loads of logging calls around your code, consider
		1068	creating a logger callback with the C<AnyEvent::Log::logger> function,
		1069	which can reduce typing, codesize and can reduce the logging overhead
		1070	enourmously.
		1071
891	=back	1072	=back
892		1073
893	=head1 WHAT TO DO IN A MODULE	1074	=head1 WHAT TO DO IN A MODULE
894		1075
895	As a module author, you should C<use AnyEvent> and call AnyEvent methods	1076	As a module author, you should C<use AnyEvent> and call AnyEvent methods
…		…
905	because it will stall the whole program, and the whole point of using	1086	because it will stall the whole program, and the whole point of using
906	events is to stay interactive.	1087	events is to stay interactive.
907		1088
908	It is fine, however, to call C<< ->recv >> when the user of your module	1089	It is fine, however, to call C<< ->recv >> when the user of your module
909	requests it (i.e. if you create a http request object ad have a method	1090	requests it (i.e. if you create a http request object ad have a method
910	called C<results> that returns the results, it should call C<< ->recv >>	1091	called C<results> that returns the results, it may call C<< ->recv >>
911	freely, as the user of your module knows what she is doing. always).	1092	freely, as the user of your module knows what she is doing. Always).
912		1093
913	=head1 WHAT TO DO IN THE MAIN PROGRAM	1094	=head1 WHAT TO DO IN THE MAIN PROGRAM
914		1095
915	There will always be a single main program - the only place that should	1096	There will always be a single main program - the only place that should
916	dictate which event model to use.	1097	dictate which event model to use.
917		1098
918	If it doesn't care, it can just "use AnyEvent" and use it itself, or not	1099	If the program is not event-based, it need not do anything special, even
919	do anything special (it does not need to be event-based) and let AnyEvent	1100	when it depends on a module that uses an AnyEvent. If the program itself
920	decide which implementation to chose if some module relies on it.	1101	uses AnyEvent, but does not care which event loop is used, all it needs
		1102	to do is C<use AnyEvent>. In either case, AnyEvent will choose the best
		1103	available loop implementation.
921		1104
922	If the main program relies on a specific event model - for example, in	1105	If the main program relies on a specific event model - for example, in
923	Gtk2 programs you have to rely on the Glib module - you should load the	1106	Gtk2 programs you have to rely on the Glib module - you should load the
924	event module before loading AnyEvent or any module that uses it: generally	1107	event module before loading AnyEvent or any module that uses it: generally
925	speaking, you should load it as early as possible. The reason is that	1108	speaking, you should load it as early as possible. The reason is that
926	modules might create watchers when they are loaded, and AnyEvent will	1109	modules might create watchers when they are loaded, and AnyEvent will
927	decide on the event model to use as soon as it creates watchers, and it	1110	decide on the event model to use as soon as it creates watchers, and it
928	might chose the wrong one unless you load the correct one yourself.	1111	might choose the wrong one unless you load the correct one yourself.
929		1112
930	You can chose to use a pure-perl implementation by loading the	1113	You can chose to use a pure-perl implementation by loading the
931	C<AnyEvent::Impl::Perl> module, which gives you similar behaviour	1114	C<AnyEvent::Loop> module, which gives you similar behaviour
932	everywhere, but letting AnyEvent chose the model is generally better.	1115	everywhere, but letting AnyEvent chose the model is generally better.
933		1116
934	=head2 MAINLOOP EMULATION	1117	=head2 MAINLOOP EMULATION
935		1118
936	Sometimes (often for short test scripts, or even standalone programs who	1119	Sometimes (often for short test scripts, or even standalone programs who
…		…
949		1132
950		1133
951	=head1 OTHER MODULES	1134	=head1 OTHER MODULES
952		1135
953	The following is a non-exhaustive list of additional modules that use	1136	The following is a non-exhaustive list of additional modules that use
954	AnyEvent as a client and can therefore be mixed easily with other AnyEvent	1137	AnyEvent as a client and can therefore be mixed easily with other
955	modules and other event loops in the same program. Some of the modules	1138	AnyEvent modules and other event loops in the same program. Some of the
956	come with AnyEvent, most are available via CPAN.	1139	modules come as part of AnyEvent, the others are available via CPAN (see
		1140	L<http://search.cpan.org/search?m=module&q=anyevent%3A%3A*> for
		1141	a longer non-exhaustive list), and the list is heavily biased towards
		1142	modules of the AnyEvent author himself :)
957		1143
958	=over 4	1144	=over 4
959		1145
960	=item L<AnyEvent::Util>	1146	=item L<AnyEvent::Util>
961		1147
962	Contains various utility functions that replace often-used but blocking	1148	Contains various utility functions that replace often-used blocking
963	functions such as C<inet_aton> by event-/callback-based versions.	1149	functions such as C<inet_aton> with event/callback-based versions.
964		1150
965	=item L<AnyEvent::Socket>	1151	=item L<AnyEvent::Socket>
966		1152
967	Provides various utility functions for (internet protocol) sockets,	1153	Provides various utility functions for (internet protocol) sockets,
968	addresses and name resolution. Also functions to create non-blocking tcp	1154	addresses and name resolution. Also functions to create non-blocking tcp
…		…
970		1156
971	=item L<AnyEvent::Handle>	1157	=item L<AnyEvent::Handle>
972		1158
973	Provide read and write buffers, manages watchers for reads and writes,	1159	Provide read and write buffers, manages watchers for reads and writes,
974	supports raw and formatted I/O, I/O queued and fully transparent and	1160	supports raw and formatted I/O, I/O queued and fully transparent and
975	non-blocking SSL/TLS (via L<AnyEvent::TLS>.	1161	non-blocking SSL/TLS (via L<AnyEvent::TLS>).
976		1162
977	=item L<AnyEvent::DNS>	1163	=item L<AnyEvent::DNS>
978		1164
979	Provides rich asynchronous DNS resolver capabilities.	1165	Provides rich asynchronous DNS resolver capabilities.
980		1166
		1167	=item L<AnyEvent::HTTP>, L<AnyEvent::IRC>, L<AnyEvent::XMPP>, L<AnyEvent::GPSD>, L<AnyEvent::IGS>, L<AnyEvent::FCP>
		1168
		1169	Implement event-based interfaces to the protocols of the same name (for
		1170	the curious, IGS is the International Go Server and FCP is the Freenet
		1171	Client Protocol).
		1172
981	=item L<AnyEvent::HTTP>	1173	=item L<AnyEvent::AIO>
982		1174
983	A simple-to-use HTTP library that is capable of making a lot of concurrent	1175	Truly asynchronous (as opposed to non-blocking) I/O, should be in the
984	HTTP requests.	1176	toolbox of every event programmer. AnyEvent::AIO transparently fuses
		1177	L<IO::AIO> and AnyEvent together, giving AnyEvent access to event-based
		1178	file I/O, and much more.
		1179
		1180	=item L<AnyEvent::Filesys::Notify>
		1181
		1182	AnyEvent is good for non-blocking stuff, but it can't detect file or
		1183	path changes (e.g. "watch this directory for new files", "watch this
		1184	file for changes"). The L<AnyEvent::Filesys::Notify> module promises to
		1185	do just that in a portbale fashion, supporting inotify on GNU/Linux and
		1186	some weird, without doubt broken, stuff on OS X to monitor files. It can
		1187	fall back to blocking scans at regular intervals transparently on other
		1188	platforms, so it's about as portable as it gets.
		1189
		1190	(I haven't used it myself, but I haven't heard anybody complaining about
		1191	it yet).
		1192
		1193	=item L<AnyEvent::DBI>
		1194
		1195	Executes L<DBI> requests asynchronously in a proxy process for you,
		1196	notifying you in an event-based way when the operation is finished.
985		1197
986	=item L<AnyEvent::HTTPD>	1198	=item L<AnyEvent::HTTPD>
987		1199
988	Provides a simple web application server framework.	1200	A simple embedded webserver.
989		1201
990	=item L<AnyEvent::FastPing>	1202	=item L<AnyEvent::FastPing>
991		1203
992	The fastest ping in the west.	1204	The fastest ping in the west.
993		1205
994	=item L<AnyEvent::DBI>
995
996	Executes L<DBI> requests asynchronously in a proxy process.
997
998	=item L<AnyEvent::AIO>
999
1000	Truly asynchronous I/O, should be in the toolbox of every event
1001	programmer. AnyEvent::AIO transparently fuses L<IO::AIO> and AnyEvent
1002	together.
1003
1004	=item L<AnyEvent::BDB>
1005
1006	Truly asynchronous Berkeley DB access. AnyEvent::BDB transparently fuses
1007	L<BDB> and AnyEvent together.
1008
1009	=item L<AnyEvent::GPSD>
1010
1011	A non-blocking interface to gpsd, a daemon delivering GPS information.
1012
1013	=item L<AnyEvent::IRC>
1014
1015	AnyEvent based IRC client module family (replacing the older Net::IRC3).
1016
1017	=item L<AnyEvent::XMPP>
1018
1019	AnyEvent based XMPP (Jabber protocol) module family (replacing the older
1020	Net::XMPP2>.
1021
1022	=item L<AnyEvent::IGS>
1023
1024	A non-blocking interface to the Internet Go Server protocol (used by
1025	L<App::IGS>).
1026
1027	=item L<Net::FCP>
1028
1029	AnyEvent-based implementation of the Freenet Client Protocol, birthplace
1030	of AnyEvent.
1031
1032	=item L<Event::ExecFlow>
1033
1034	High level API for event-based execution flow control.
1035
1036	=item L<Coro>	1206	=item L<Coro>
1037		1207
1038	Has special support for AnyEvent via L<Coro::AnyEvent>.	1208	Has special support for AnyEvent via L<Coro::AnyEvent>, which allows you
		1209	to simply invert the flow control - don't call us, we will call you:
		1210
		1211	async {
		1212	Coro::AnyEvent::sleep 5; # creates a 5s timer and waits for it
		1213	print "5 seconds later!\n";
		1214
		1215	Coro::AnyEvent::readable *STDIN; # uses an I/O watcher
		1216	my $line = <STDIN>; # works for ttys
		1217
		1218	AnyEvent::HTTP::http_get "url", Coro::rouse_cb;
		1219	my ($body, $hdr) = Coro::rouse_wait;
		1220	};
1039		1221
1040	=back	1222	=back
1041		1223
1042	=cut	1224	=cut
1043		1225
1044	package AnyEvent;	1226	package AnyEvent;
1045		1227
1046	# basically a tuned-down version of common::sense	1228	# basically a tuned-down version of common::sense
1047	sub common_sense {	1229	sub common_sense {
1048	# no warnings	1230	# from common:.sense 3.4
1049	${^WARNING_BITS} ^= ${^WARNING_BITS};	1231	${^WARNING_BITS} ^= ${^WARNING_BITS} ^ "\x3c\x3f\x33\x00\x0f\xf0\x0f\xc0\xf0\xfc\x33\x00";
1050	# use strict vars subs	1232	# use strict vars subs - NO UTF-8, as Util.pm doesn't like this atm. (uts46data.pl)
1051	$^H |= 0x00000600;	1233	$^H |= 0x00000600;
1052	}	1234	}
1053		1235
1054	BEGIN { AnyEvent::common_sense }	1236	BEGIN { AnyEvent::common_sense }
1055		1237
1056	use Carp ();	1238	use Carp ();
1057		1239
1058	our $VERSION = 4.85;	1240	our $VERSION = '6.02';
1059	our $MODEL;	1241	our $MODEL;
1060		1242
1061	our $AUTOLOAD;
1062	our @ISA;	1243	our @ISA;
1063		1244
1064	our @REGISTRY;	1245	our @REGISTRY;
1065		1246
1066	our $WIN32;
1067
1068	our $VERBOSE;	1247	our $VERBOSE;
1069		1248
1070	BEGIN {	1249	BEGIN {
1071	eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }";	1250	require "AnyEvent/constants.pl";
		1251
1072	eval "sub TAINT(){ " . (${^TAINT}*1) . " }";	1252	eval "sub TAINT (){" . (${^TAINT}*1) . "}";
1073		1253
1074	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}	1254	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}
1075	if ${^TAINT};	1255	if ${^TAINT};
1076		1256
1077	$VERBOSE = $ENV{PERL_ANYEVENT_VERBOSE}*1;	1257	$ENV{"PERL_ANYEVENT_$_"} = $ENV{"AE_$_"}
		1258	for grep s/^AE_// && !exists $ENV{"PERL_ANYEVENT_$_"}, keys %ENV;
1078		1259
		1260	@ENV{grep /^PERL_ANYEVENT_/, keys %ENV} = ()
		1261	if ${^TAINT};
		1262
		1263	# $ENV{PERL_ANYEVENT_xxx} now valid
		1264
		1265	$VERBOSE = length $ENV{PERL_ANYEVENT_VERBOSE} ? $ENV{PERL_ANYEVENT_VERBOSE}*1 : 3;
1079	}	1266	}
1080		1267
1081	our $MAX_SIGNAL_LATENCY = 10;	1268	our $MAX_SIGNAL_LATENCY = 10;
1082		1269
1083	our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred	1270	our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred
…		…
1087	$PROTOCOL{$_} = ++$idx	1274	$PROTOCOL{$_} = ++$idx
1088	for reverse split /\s*,\s*/,	1275	for reverse split /\s*,\s*/,
1089	$ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";	1276	$ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";
1090	}	1277	}
1091		1278
		1279	our @post_detect;
		1280
		1281	sub post_detect(&) {
		1282	my ($cb) = @_;
		1283
		1284	push @post_detect, $cb;
		1285
		1286	defined wantarray
		1287	? bless \$cb, "AnyEvent::Util::postdetect"
		1288	: ()
		1289	}
		1290
		1291	sub AnyEvent::Util::postdetect::DESTROY {
		1292	@post_detect = grep $_ != ${$_[0]}, @post_detect;
		1293	}
		1294
		1295	our $POSTPONE_W;
		1296	our @POSTPONE;
		1297
		1298	sub _postpone_exec {
		1299	undef $POSTPONE_W;
		1300
		1301	&{ shift @POSTPONE }
		1302	while @POSTPONE;
		1303	}
		1304
		1305	sub postpone(&) {
		1306	push @POSTPONE, shift;
		1307
		1308	$POSTPONE_W ||= AE::timer (0, 0, \&_postpone_exec);
		1309
		1310	()
		1311	}
		1312
		1313	sub log($$;@) {
		1314	# only load the big bloated module when we actually are about to log something
		1315	if ($_[0] <= $VERBOSE) { # also catches non-numeric levels(!)
		1316	require AnyEvent::Log;
		1317	# AnyEvent::Log overwrites this function
		1318	goto &log;
		1319	}
		1320
		1321	0 # not logged
		1322	}
		1323
		1324	if (length $ENV{PERL_ANYEVENT_LOG}) {
		1325	require AnyEvent::Log; # AnyEvent::Log does the thing for us
		1326	}
		1327
1092	my @models = (	1328	our @models = (
1093	[EV:: => AnyEvent::Impl::EV::],	1329	[EV:: => AnyEvent::Impl::EV:: , 1],
1094	[Event:: => AnyEvent::Impl::Event::],	1330	[AnyEvent::Loop:: => AnyEvent::Impl::Perl:: , 1],
1095	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::],
1096	# everything below here will not be autoprobed	1331	# everything below here will not (normally) be autoprobed
1097	# as the pureperl backend should work everywhere	1332	# as the pure perl backend should work everywhere
1098	# and is usually faster	1333	# and is usually faster
		1334	[Event:: => AnyEvent::Impl::Event::, 1],
1099	[Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers	1335	[Glib:: => AnyEvent::Impl::Glib:: , 1], # becomes extremely slow with many watchers
1100	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy	1336	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
		1337	[Irssi:: => AnyEvent::Impl::Irssi::], # Irssi has a bogus "Event" package
1101	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles	1338	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
1102	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program	1339	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program
1103	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza	1340	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
1104	[Wx:: => AnyEvent::Impl::POE::],	1341	[Wx:: => AnyEvent::Impl::POE::],
1105	[Prima:: => AnyEvent::Impl::POE::],	1342	[Prima:: => AnyEvent::Impl::POE::],
1106	# IO::Async is just too broken - we would need workarounds for its	1343	[IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # a bitch to autodetect
1107	# byzantine signal and broken child handling, among others.	1344	[Cocoa::EventLoop:: => AnyEvent::Impl::Cocoa::],
1108	# IO::Async is rather hard to detect, as it doesn't have any	1345	[FLTK:: => AnyEvent::Impl::FLTK::],
1109	# obvious default class.
1110	# [IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program
1111	# [IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program
1112	# [IO::Async::Notifier:: => AnyEvent::Impl::IOAsync::], # requires special main program
1113	);	1346	);
1114		1347
1115	our %method = map +($_ => 1),	1348	our @isa_hook;
		1349
		1350	sub _isa_set {
		1351	my @pkg = ("AnyEvent", (map $_->[0], grep defined, @isa_hook), $MODEL);
		1352
		1353	@{"$pkg[$_-1]::ISA"} = $pkg[$_]
		1354	for 1 .. $#pkg;
		1355
		1356	grep $_ && $_->[1], @isa_hook
		1357	and AE::_reset ();
		1358	}
		1359
		1360	# used for hooking AnyEvent::Strict and AnyEvent::Debug::Wrap into the class hierarchy
		1361	sub _isa_hook($$;$) {
		1362	my ($i, $pkg, $reset_ae) = @_;
		1363
		1364	$isa_hook[$i] = $pkg ? [$pkg, $reset_ae] : undef;
		1365
		1366	_isa_set;
		1367	}
		1368
		1369	# all autoloaded methods reserve the complete glob, not just the method slot.
		1370	# due to bugs in perls method cache implementation.
1116	qw(io timer time now now_update signal child idle condvar one_event DESTROY);	1371	our @methods = qw(io timer time now now_update signal child idle condvar);
1117		1372
1118	our @post_detect;
1119
1120	sub post_detect(&) {	1373	sub detect() {
1121	my ($cb) = @_;	1374	return $MODEL if $MODEL; # some programs keep references to detect
1122		1375
1123	if ($MODEL) {	1376	local $!; # for good measure
1124	$cb->();	1377	local $SIG{__DIE__}; # we use eval
1125		1378
1126	1	1379	# free some memory
		1380	*detect = sub () { $MODEL };
		1381	# undef &func doesn't correctly update the method cache. grmbl.
		1382	# so we delete the whole glob. grmbl.
		1383	# otoh, perl doesn't let me undef an active usb, but it lets me free
		1384	# a glob with an active sub. hrm. i hope it works, but perl is
		1385	# usually buggy in this department. sigh.
		1386	delete @{"AnyEvent::"}{@methods};
		1387	undef @methods;
		1388
		1389	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z0-9:]+)$/) {
		1390	my $model = $1;
		1391	$model = "AnyEvent::Impl::$model" unless $model =~ s/::$//;
		1392	if (eval "require $model") {
		1393	AnyEvent::log 7 => "loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.";
		1394	$MODEL = $model;
1127	} else {	1395	} else {
1128	push @post_detect, $cb;	1396	AnyEvent::log 5 => "unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@";
1129		1397	}
1130	defined wantarray
1131	? bless \$cb, "AnyEvent::Util::postdetect"
1132	: ()
1133	}	1398	}
1134	}
1135		1399
1136	sub AnyEvent::Util::postdetect::DESTROY {	1400	# check for already loaded models
1137	@post_detect = grep $_ != ${$_[0]}, @post_detect;
1138	}
1139
1140	sub detect() {
1141	unless ($MODEL) {	1401	unless ($MODEL) {
1142	local $SIG{__DIE__};	1402	for (@REGISTRY, @models) {
1143		1403	my ($package, $model) = @$_;
1144	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {	1404	if (${"$package\::VERSION"} > 0) {
1145	my $model = "AnyEvent::Impl::$1";
1146	if (eval "require $model") {	1405	if (eval "require $model") {
		1406	AnyEvent::log 7 => "autodetected model '$model', using it.";
1147	$MODEL = $model;	1407	$MODEL = $model;
1148	warn "AnyEvent: loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.\n" if $VERBOSE >= 2;	1408	last;
1149	} else {	1409	}
1150	warn "AnyEvent: unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@" if $VERBOSE;
1151	}	1410	}
1152	}	1411	}
1153		1412
1154	# check for already loaded models
1155	unless ($MODEL) {	1413	unless ($MODEL) {
		1414	# try to autoload a model
1156	for (@REGISTRY, @models) {	1415	for (@REGISTRY, @models) {
1157	my ($package, $model) = @$_;	1416	my ($package, $model, $autoload) = @$_;
		1417	if (
		1418	$autoload
		1419	and eval "require $package"
1158	if (${"$package\::VERSION"} > 0) {	1420	and ${"$package\::VERSION"} > 0
1159	if (eval "require $model") {	1421	and eval "require $model"
		1422	) {
		1423	AnyEvent::log 7 => "autoloaded model '$model', using it.";
1160	$MODEL = $model;	1424	$MODEL = $model;
1161	warn "AnyEvent: autodetected model '$model', using it.\n" if $VERBOSE >= 2;
1162	last;	1425	last;
1163	}
1164	}	1426	}
1165	}	1427	}
1166		1428
1167	unless ($MODEL) {
1168	# try to load a model
1169
1170	for (@REGISTRY, @models) {
1171	my ($package, $model) = @$_;
1172	if (eval "require $package"
1173	and ${"$package\::VERSION"} > 0
1174	and eval "require $model") {
1175	$MODEL = $model;
1176	warn "AnyEvent: autoprobed model '$model', using it.\n" if $VERBOSE >= 2;
1177	last;
1178	}
1179	}
1180
1181	$MODEL	1429	$MODEL
1182	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.\n";	1430	or die "AnyEvent: backend autodetection failed - did you properly install AnyEvent?";
1183	}
1184	}	1431	}
1185
1186	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
1187
1188	unshift @ISA, $MODEL;
1189
1190	require AnyEvent::Strict if $ENV{PERL_ANYEVENT_STRICT};
1191
1192	(shift @post_detect)->() while @post_detect;
1193	}	1432	}
1194		1433
		1434	# free memory only needed for probing
		1435	undef @models;
		1436	undef @REGISTRY;
		1437
		1438	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
		1439
		1440	# now nuke some methods that are overridden by the backend.
		1441	# SUPER usage is not allowed in these.
		1442	for (qw(time signal child idle)) {
		1443	undef &{"AnyEvent::Base::$_"}
		1444	if defined &{"$MODEL\::$_"};
		1445	}
		1446
		1447	_isa_set;
		1448
		1449	# we're officially open!
		1450
		1451	if ($ENV{PERL_ANYEVENT_STRICT}) {
		1452	require AnyEvent::Strict;
		1453	}
		1454
		1455	if ($ENV{PERL_ANYEVENT_DEBUG_WRAP}) {
		1456	require AnyEvent::Debug;
		1457	AnyEvent::Debug::wrap ($ENV{PERL_ANYEVENT_DEBUG_WRAP});
		1458	}
		1459
		1460	if (length $ENV{PERL_ANYEVENT_DEBUG_SHELL}) {
		1461	require AnyEvent::Socket;
		1462	require AnyEvent::Debug;
		1463
		1464	my $shell = $ENV{PERL_ANYEVENT_DEBUG_SHELL};
		1465	$shell =~ s/\$\$/$$/g;
		1466
		1467	my ($host, $service) = AnyEvent::Socket::parse_hostport ($shell);
		1468	$AnyEvent::Debug::SHELL = AnyEvent::Debug::shell ($host, $service);
		1469	}
		1470
		1471	# now the anyevent environment is set up as the user told us to, so
		1472	# call the actual user code - post detects
		1473
		1474	(shift @post_detect)->() while @post_detect;
		1475	undef @post_detect;
		1476
		1477	*post_detect = sub(&) {
		1478	shift->();
		1479
		1480	undef
		1481	};
		1482
1195	$MODEL	1483	$MODEL
1196	}	1484	}
1197		1485
1198	sub AUTOLOAD {	1486	for my $name (@methods) {
1199	(my $func = $AUTOLOAD) =~ s/.*://;	1487	*$name = sub {
1200		1488	detect;
1201	$method{$func}	1489	# we use goto because
1202	or Carp::croak "$func: not a valid method for AnyEvent objects";	1490	# a) it makes the thunk more transparent
1203		1491	# b) it allows us to delete the thunk later
1204	detect unless $MODEL;	1492	goto &{ UNIVERSAL::can AnyEvent => "SUPER::$name" }
1205		1493	};
1206	my $class = shift;
1207	$class->$func (@_);
1208	}	1494	}
1209		1495
1210	# utility function to dup a filehandle. this is used by many backends	1496	# utility function to dup a filehandle. this is used by many backends
1211	# to support binding more than one watcher per filehandle (they usually	1497	# to support binding more than one watcher per filehandle (they usually
1212	# allow only one watcher per fd, so we dup it to get a different one).	1498	# allow only one watcher per fd, so we dup it to get a different one).
…		…
1222	# we assume CLOEXEC is already set by perl in all important cases	1508	# we assume CLOEXEC is already set by perl in all important cases
1223		1509
1224	($fh2, $rw)	1510	($fh2, $rw)
1225	}	1511	}
1226		1512
		1513	=head1 SIMPLIFIED AE API
		1514
		1515	Starting with version 5.0, AnyEvent officially supports a second, much
		1516	simpler, API that is designed to reduce the calling, typing and memory
		1517	overhead by using function call syntax and a fixed number of parameters.
		1518
		1519	See the L<AE> manpage for details.
		1520
		1521	=cut
		1522
		1523	package AE;
		1524
		1525	our $VERSION = $AnyEvent::VERSION;
		1526
		1527	sub _reset() {
		1528	eval q{
		1529	# fall back to the main API by default - backends and AnyEvent::Base
		1530	# implementations can overwrite these.
		1531
		1532	sub io($$$) {
		1533	AnyEvent->io (fh => $_[0], poll => $_[1] ? "w" : "r", cb => $_[2])
		1534	}
		1535
		1536	sub timer($$$) {
		1537	AnyEvent->timer (after => $_[0], interval => $_[1], cb => $_[2])
		1538	}
		1539
		1540	sub signal($$) {
		1541	AnyEvent->signal (signal => $_[0], cb => $_[1])
		1542	}
		1543
		1544	sub child($$) {
		1545	AnyEvent->child (pid => $_[0], cb => $_[1])
		1546	}
		1547
		1548	sub idle($) {
		1549	AnyEvent->idle (cb => $_[0]);
		1550	}
		1551
		1552	sub cv(;&) {
		1553	AnyEvent->condvar (@_ ? (cb => $_[0]) : ())
		1554	}
		1555
		1556	sub now() {
		1557	AnyEvent->now
		1558	}
		1559
		1560	sub now_update() {
		1561	AnyEvent->now_update
		1562	}
		1563
		1564	sub time() {
		1565	AnyEvent->time
		1566	}
		1567
		1568	*postpone = \&AnyEvent::postpone;
		1569	*log = \&AnyEvent::log;
		1570	};
		1571	die if $@;
		1572	}
		1573
		1574	BEGIN { _reset }
		1575
1227	package AnyEvent::Base;	1576	package AnyEvent::Base;
1228		1577
1229	# default implementations for many methods	1578	# default implementations for many methods
1230		1579
1231	sub _time {	1580	sub time {
		1581	eval q{ # poor man's autoloading {}
1232	# probe for availability of Time::HiRes	1582	# probe for availability of Time::HiRes
1233	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {	1583	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {
1234	warn "AnyEvent: using Time::HiRes for sub-second timing accuracy.\n" if $VERBOSE >= 8;	1584	*time = sub { Time::HiRes::time () };
1235	*_time = \&Time::HiRes::time;	1585	*AE::time = \& Time::HiRes::time ;
		1586	*now = \&time;
		1587	AnyEvent::log 8 => "AnyEvent: using Time::HiRes for sub-second timing accuracy.";
1236	# if (eval "use POSIX (); (POSIX::times())...	1588	# if (eval "use POSIX (); (POSIX::times())...
1237	} else {	1589	} else {
		1590	*time = sub { CORE::time };
		1591	*AE::time = sub (){ CORE::time };
		1592	*now = \&time;
1238	warn "AnyEvent: using built-in time(), WARNING, no sub-second resolution!\n" if $VERBOSE;	1593	AnyEvent::log 3 => "using built-in time(), WARNING, no sub-second resolution!";
1239	*_time = sub { time }; # epic fail	1594	}
1240	}	1595	};
		1596	die if $@;
1241		1597
1242	&_time	1598	&time
1243	}	1599	}
1244		1600
1245	sub time { _time }	1601	*now = \&time;
1246	sub now { _time }
1247	sub now_update { }	1602	sub now_update { }
1248		1603
		1604	sub _poll {
		1605	Carp::croak "$AnyEvent::MODEL does not support blocking waits. Caught";
		1606	}
		1607
1249	# default implementation for ->condvar	1608	# default implementation for ->condvar
		1609	# in fact, the default should not be overwritten
1250		1610
1251	sub condvar {	1611	sub condvar {
		1612	eval q{ # poor man's autoloading {}
		1613	*condvar = sub {
1252	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"	1614	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"
		1615	};
		1616
		1617	*AE::cv = sub (;&) {
		1618	bless { @_ ? (_ae_cb => shift) : () }, "AnyEvent::CondVar"
		1619	};
		1620	};
		1621	die if $@;
		1622
		1623	&condvar
1253	}	1624	}
1254		1625
1255	# default implementation for ->signal	1626	# default implementation for ->signal
1256		1627
1257	our $HAVE_ASYNC_INTERRUPT;	1628	our $HAVE_ASYNC_INTERRUPT;
		1629
		1630	sub _have_async_interrupt() {
		1631	$HAVE_ASYNC_INTERRUPT = 1*(!$ENV{PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT}
		1632	&& eval "use Async::Interrupt 1.02 (); 1")
		1633	unless defined $HAVE_ASYNC_INTERRUPT;
		1634
		1635	$HAVE_ASYNC_INTERRUPT
		1636	}
		1637
1258	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);	1638	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);
1259	our (%SIG_ASY, %SIG_ASY_W);	1639	our (%SIG_ASY, %SIG_ASY_W);
1260	our ($SIG_COUNT, $SIG_TW);	1640	our ($SIG_COUNT, $SIG_TW);
1261		1641
1262	sub _signal_exec {
1263	$HAVE_ASYNC_INTERRUPT
1264	? $SIGPIPE_R->drain
1265	: sysread $SIGPIPE_R, my $dummy, 9;
1266
1267	while (%SIG_EV) {
1268	for (keys %SIG_EV) {
1269	delete $SIG_EV{$_};
1270	$_->() for values %{ $SIG_CB{$_} || {} };
1271	}
1272	}
1273	}
1274
1275	# install a dumym wakeupw atcher to reduce signal catching latency	1642	# install a dummy wakeup watcher to reduce signal catching latency
		1643	# used by Impls
1276	sub _sig_add() {	1644	sub _sig_add() {
1277	unless ($SIG_COUNT++) {	1645	unless ($SIG_COUNT++) {
1278	# try to align timer on a full-second boundary, if possible	1646	# try to align timer on a full-second boundary, if possible
1279	my $NOW = AnyEvent->now;	1647	my $NOW = AE::now;
1280		1648
1281	$SIG_TW = AnyEvent->timer (	1649	$SIG_TW = AE::timer
1282	after => $MAX_SIGNAL_LATENCY - ($NOW - int $NOW),	1650	$MAX_SIGNAL_LATENCY - ($NOW - int $NOW),
1283	interval => $MAX_SIGNAL_LATENCY,	1651	$MAX_SIGNAL_LATENCY,
1284	cb => sub { }, # just for the PERL_ASYNC_CHECK	1652	sub { } # just for the PERL_ASYNC_CHECK
1285	);	1653	;
1286	}	1654	}
1287	}	1655	}
1288		1656
1289	sub _sig_del {	1657	sub _sig_del {
1290	undef $SIG_TW	1658	undef $SIG_TW
1291	unless --$SIG_COUNT;	1659	unless --$SIG_COUNT;
1292	}	1660	}
1293		1661
		1662	our $_sig_name_init; $_sig_name_init = sub {
		1663	eval q{ # poor man's autoloading {}
		1664	undef $_sig_name_init;
		1665
		1666	if (_have_async_interrupt) {
		1667	*sig2num = \&Async::Interrupt::sig2num;
		1668	*sig2name = \&Async::Interrupt::sig2name;
		1669	} else {
		1670	require Config;
		1671
		1672	my %signame2num;
		1673	@signame2num{ split ' ', $Config::Config{sig_name} }
		1674	= split ' ', $Config::Config{sig_num};
		1675
		1676	my @signum2name;
		1677	@signum2name[values %signame2num] = keys %signame2num;
		1678
		1679	*sig2num = sub($) {
		1680	$_[0] > 0 ? shift : $signame2num{+shift}
		1681	};
		1682	*sig2name = sub ($) {
		1683	$_[0] > 0 ? $signum2name[+shift] : shift
		1684	};
		1685	}
		1686	};
		1687	die if $@;
		1688	};
		1689
		1690	sub sig2num ($) { &$_sig_name_init; &sig2num }
		1691	sub sig2name($) { &$_sig_name_init; &sig2name }
		1692
1294	sub _signal {	1693	sub signal {
1295	my (undef, %arg) = @_;	1694	eval q{ # poor man's autoloading {}
		1695	# probe for availability of Async::Interrupt
		1696	if (_have_async_interrupt) {
		1697	AnyEvent::log 8 => "using Async::Interrupt for race-free signal handling.";
1296		1698
1297	my $signal = uc $arg{signal}	1699	$SIGPIPE_R = new Async::Interrupt::EventPipe;
1298	or Carp::croak "required option 'signal' is missing";	1700	$SIG_IO = AE::io $SIGPIPE_R->fileno, 0, \&_signal_exec;
1299		1701
1300	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};	1702	} else {
		1703	AnyEvent::log 8 => "using emulated perl signal handling with latency timer.";
1301		1704
1302	if ($HAVE_ASYNC_INTERRUPT) {	1705	if (AnyEvent::WIN32) {
1303	# async::interrupt	1706	require AnyEvent::Util;
1304		1707
1305	$SIG_ASY{$signal} ||= do {	1708	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
1306	my $asy = new Async::Interrupt	1709	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R, 1) if $SIGPIPE_R;
1307	cb => sub { undef $SIG_EV{$signal} },	1710	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W, 1) if $SIGPIPE_W; # just in case
1308	signal => $signal,	1711	} else {
1309	pipe => [$SIGPIPE_R->filenos],	1712	pipe $SIGPIPE_R, $SIGPIPE_W;
		1713	fcntl $SIGPIPE_R, AnyEvent::F_SETFL, AnyEvent::O_NONBLOCK if $SIGPIPE_R;
		1714	fcntl $SIGPIPE_W, AnyEvent::F_SETFL, AnyEvent::O_NONBLOCK if $SIGPIPE_W; # just in case
		1715
		1716	# not strictly required, as $^F is normally 2, but let's make sure...
		1717	fcntl $SIGPIPE_R, AnyEvent::F_SETFD, AnyEvent::FD_CLOEXEC;
		1718	fcntl $SIGPIPE_W, AnyEvent::F_SETFD, AnyEvent::FD_CLOEXEC;
1310	;	1719	}
1311	$asy->pipe_autodrain (0);
1312		1720
1313	$asy	1721	$SIGPIPE_R
		1722	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";
		1723
		1724	$SIG_IO = AE::io $SIGPIPE_R, 0, \&_signal_exec;
		1725	}
		1726
		1727	*signal = $HAVE_ASYNC_INTERRUPT
		1728	? sub {
		1729	my (undef, %arg) = @_;
		1730
		1731	# async::interrupt
		1732	my $signal = sig2num $arg{signal};
		1733	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
		1734
		1735	$SIG_ASY{$signal} ||= new Async::Interrupt
		1736	cb => sub { undef $SIG_EV{$signal} },
		1737	signal => $signal,
		1738	pipe => [$SIGPIPE_R->filenos],
		1739	pipe_autodrain => 0,
		1740	;
		1741
		1742	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
		1743	}
		1744	: sub {
		1745	my (undef, %arg) = @_;
		1746
		1747	# pure perl
		1748	my $signal = sig2name $arg{signal};
		1749	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
		1750
		1751	$SIG{$signal} ||= sub {
		1752	local $!;
		1753	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;
		1754	undef $SIG_EV{$signal};
		1755	};
		1756
		1757	# can't do signal processing without introducing races in pure perl,
		1758	# so limit the signal latency.
		1759	_sig_add;
		1760
		1761	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
		1762	}
		1763	;
		1764
		1765	*AnyEvent::Base::signal::DESTROY = sub {
		1766	my ($signal, $cb) = @{$_[0]};
		1767
		1768	_sig_del;
		1769
		1770	delete $SIG_CB{$signal}{$cb};
		1771
		1772	$HAVE_ASYNC_INTERRUPT
		1773	? delete $SIG_ASY{$signal}
		1774	: # delete doesn't work with older perls - they then
		1775	# print weird messages, or just unconditionally exit
		1776	# instead of getting the default action.
		1777	undef $SIG{$signal}
		1778	unless keys %{ $SIG_CB{$signal} };
1314	};	1779	};
1315		1780
1316	} else {	1781	*_signal_exec = sub {
1317	# pure perl	1782	$HAVE_ASYNC_INTERRUPT
		1783	? $SIGPIPE_R->drain
		1784	: sysread $SIGPIPE_R, (my $dummy), 9;
1318		1785
1319	$SIG{$signal} ||= sub {	1786	while (%SIG_EV) {
1320	local $!;	1787	for (keys %SIG_EV) {
1321	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;	1788	delete $SIG_EV{$_};
1322	undef $SIG_EV{$signal};	1789	&$_ for values %{ $SIG_CB{$_} || {} };
		1790	}
		1791	}
1323	};	1792	};
1324
1325	# can't do signal processing without introducing races in pure perl,
1326	# so limit the signal latency.
1327	_sig_add;
1328	}	1793	};
		1794	die if $@;
1329		1795
1330	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
1331	}
1332
1333	sub signal {
1334	# probe for availability of Async::Interrupt
1335	if (!$ENV{PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT} && eval "use Async::Interrupt 0.6 (); 1") {
1336	warn "AnyEvent: using Async::Interrupt for race-free signal handling.\n" if $VERBOSE >= 8;
1337
1338	$HAVE_ASYNC_INTERRUPT = 1;
1339	$SIGPIPE_R = new Async::Interrupt::EventPipe;
1340	$SIG_IO = AnyEvent->io (fh => $SIGPIPE_R->fileno, poll => "r", cb => \&_signal_exec);
1341
1342	} else {
1343	warn "AnyEvent: using emulated perl signal handling with latency timer.\n" if $VERBOSE >= 8;
1344
1345	require Fcntl;
1346
1347	if (AnyEvent::WIN32) {
1348	require AnyEvent::Util;
1349
1350	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
1351	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R) if $SIGPIPE_R;
1352	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W) if $SIGPIPE_W; # just in case
1353	} else {
1354	pipe $SIGPIPE_R, $SIGPIPE_W;
1355	fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R;
1356	fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case
1357
1358	# not strictly required, as $^F is normally 2, but let's make sure...
1359	fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
1360	fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
1361	}
1362
1363	$SIGPIPE_R
1364	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";
1365
1366	$SIG_IO = AnyEvent->io (fh => $SIGPIPE_R, poll => "r", cb => \&_signal_exec);
1367	}
1368
1369	*signal = \&_signal;
1370	&signal	1796	&signal
1371	}
1372
1373	sub AnyEvent::Base::signal::DESTROY {
1374	my ($signal, $cb) = @{$_[0]};
1375
1376	_sig_del;
1377
1378	delete $SIG_CB{$signal}{$cb};
1379
1380	$HAVE_ASYNC_INTERRUPT
1381	? delete $SIG_ASY{$signal}
1382	: # delete doesn't work with older perls - they then
1383	# print weird messages, or just unconditionally exit
1384	# instead of getting the default action.
1385	undef $SIG{$signal}
1386	unless keys %{ $SIG_CB{$signal} };
1387	}	1797	}
1388		1798
1389	# default implementation for ->child	1799	# default implementation for ->child
1390		1800
1391	our %PID_CB;	1801	our %PID_CB;
1392	our $CHLD_W;	1802	our $CHLD_W;
1393	our $CHLD_DELAY_W;	1803	our $CHLD_DELAY_W;
1394	our $WNOHANG;
1395		1804
1396	sub _sigchld {	1805	# used by many Impl's
1397	while (0 < (my $pid = waitpid -1, $WNOHANG)) {	1806	sub _emit_childstatus($$) {
1398	$_->($pid, $?)	1807	my (undef, $rpid, $rstatus) = @_;
		1808
		1809	$_->($rpid, $rstatus)
1399	for values %{ $PID_CB{$pid} || {} },	1810	for values %{ $PID_CB{$rpid} || {} },
1400	values %{ $PID_CB{0} || {} };	1811	values %{ $PID_CB{0} || {} };
1401	}
1402	}	1812	}
1403		1813
1404	sub child {	1814	sub child {
		1815	eval q{ # poor man's autoloading {}
		1816	*_sigchld = sub {
		1817	my $pid;
		1818
		1819	AnyEvent->_emit_childstatus ($pid, $?)
		1820	while ($pid = waitpid -1, WNOHANG) > 0;
		1821	};
		1822
		1823	*child = sub {
1405	my (undef, %arg) = @_;	1824	my (undef, %arg) = @_;
1406		1825
1407	defined (my $pid = $arg{pid} + 0)	1826	my $pid = $arg{pid};
1408	or Carp::croak "required option 'pid' is missing";	1827	my $cb = $arg{cb};
1409		1828
1410	$PID_CB{$pid}{$arg{cb}} = $arg{cb};	1829	$PID_CB{$pid}{$cb+0} = $cb;
1411		1830
1412	# WNOHANG is almost cetrainly 1 everywhere
1413	$WNOHANG ||= $^O =~ /^(?:openbsd|netbsd|linux|freebsd|cygwin|MSWin32)$/
1414	? 1
1415	: eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1;
1416
1417	unless ($CHLD_W) {	1831	unless ($CHLD_W) {
1418	$CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld);	1832	$CHLD_W = AE::signal CHLD => \&_sigchld;
1419	# child could be a zombie already, so make at least one round	1833	# child could be a zombie already, so make at least one round
1420	&_sigchld;	1834	&_sigchld;
1421	}	1835	}
1422		1836
1423	bless [$pid, $arg{cb}], "AnyEvent::Base::child"	1837	bless [$pid, $cb+0], "AnyEvent::Base::child"
1424	}	1838	};
1425		1839
1426	sub AnyEvent::Base::child::DESTROY {	1840	*AnyEvent::Base::child::DESTROY = sub {
1427	my ($pid, $cb) = @{$_[0]};	1841	my ($pid, $icb) = @{$_[0]};
1428		1842
1429	delete $PID_CB{$pid}{$cb};	1843	delete $PID_CB{$pid}{$icb};
1430	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };	1844	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };
1431		1845
1432	undef $CHLD_W unless keys %PID_CB;	1846	undef $CHLD_W unless keys %PID_CB;
		1847	};
		1848	};
		1849	die if $@;
		1850
		1851	&child
1433	}	1852	}
1434		1853
1435	# idle emulation is done by simply using a timer, regardless	1854	# idle emulation is done by simply using a timer, regardless
1436	# of whether the process is idle or not, and not letting	1855	# of whether the process is idle or not, and not letting
1437	# the callback use more than 50% of the time.	1856	# the callback use more than 50% of the time.
1438	sub idle {	1857	sub idle {
		1858	eval q{ # poor man's autoloading {}
		1859	*idle = sub {
1439	my (undef, %arg) = @_;	1860	my (undef, %arg) = @_;
1440		1861
1441	my ($cb, $w, $rcb) = $arg{cb};	1862	my ($cb, $w, $rcb) = $arg{cb};
1442		1863
1443	$rcb = sub {	1864	$rcb = sub {
1444	if ($cb) {	1865	if ($cb) {
1445	$w = _time;	1866	$w = AE::time;
1446	&$cb;	1867	&$cb;
1447	$w = _time - $w;	1868	$w = AE::time - $w;
1448		1869
1449	# never use more then 50% of the time for the idle watcher,	1870	# never use more then 50% of the time for the idle watcher,
1450	# within some limits	1871	# within some limits
1451	$w = 0.0001 if $w < 0.0001;	1872	$w = 0.0001 if $w < 0.0001;
1452	$w = 5 if $w > 5;	1873	$w = 5 if $w > 5;
1453		1874
1454	$w = AnyEvent->timer (after => $w, cb => $rcb);	1875	$w = AE::timer $w, 0, $rcb;
1455	} else {	1876	} else {
1456	# clean up...	1877	# clean up...
1457	undef $w;	1878	undef $w;
1458	undef $rcb;	1879	undef $rcb;
		1880	}
		1881	};
		1882
		1883	$w = AE::timer 0.05, 0, $rcb;
		1884
		1885	bless \\$cb, "AnyEvent::Base::idle"
1459	}	1886	};
		1887
		1888	*AnyEvent::Base::idle::DESTROY = sub {
		1889	undef $${$_[0]};
		1890	};
1460	};	1891	};
		1892	die if $@;
1461		1893
1462	$w = AnyEvent->timer (after => 0.05, cb => $rcb);	1894	&idle
1463
1464	bless \\$cb, "AnyEvent::Base::idle"
1465	}
1466
1467	sub AnyEvent::Base::idle::DESTROY {
1468	undef $${$_[0]};
1469	}	1895	}
1470		1896
1471	package AnyEvent::CondVar;	1897	package AnyEvent::CondVar;
1472		1898
1473	our @ISA = AnyEvent::CondVar::Base::;	1899	our @ISA = AnyEvent::CondVar::Base::;
		1900
		1901	# only to be used for subclassing
		1902	sub new {
		1903	my $class = shift;
		1904	bless AnyEvent->condvar (@_), $class
		1905	}
1474		1906
1475	package AnyEvent::CondVar::Base;	1907	package AnyEvent::CondVar::Base;
1476		1908
1477	#use overload	1909	#use overload
1478	# '&{}' => sub { my $self = shift; sub { $self->send (@_) } },	1910	# '&{}' => sub { my $self = shift; sub { $self->send (@_) } },
…		…
1488		1920
1489	sub _send {	1921	sub _send {
1490	# nop	1922	# nop
1491	}	1923	}
1492		1924
		1925	sub _wait {
		1926	AnyEvent->_poll until $_[0]{_ae_sent};
		1927	}
		1928
1493	sub send {	1929	sub send {
1494	my $cv = shift;	1930	my $cv = shift;
1495	$cv->{_ae_sent} = [@_];	1931	$cv->{_ae_sent} = [@_];
1496	(delete $cv->{_ae_cb})->($cv) if $cv->{_ae_cb};	1932	(delete $cv->{_ae_cb})->($cv) if $cv->{_ae_cb};
1497	$cv->_send;	1933	$cv->_send;
…		…
1504		1940
1505	sub ready {	1941	sub ready {
1506	$_[0]{_ae_sent}	1942	$_[0]{_ae_sent}
1507	}	1943	}
1508		1944
1509	sub _wait {
1510	$WAITING
1511	and !$_[0]{_ae_sent}
1512	and Carp::croak "AnyEvent::CondVar: recursive blocking wait detected";
1513
1514	local $WAITING = 1;
1515	AnyEvent->one_event while !$_[0]{_ae_sent};
1516	}
1517
1518	sub recv {	1945	sub recv {
		1946	unless ($_[0]{_ae_sent}) {
		1947	$WAITING
		1948	and Carp::croak "AnyEvent::CondVar: recursive blocking wait attempted";
		1949
		1950	local $WAITING = 1;
1519	$_[0]->_wait;	1951	$_[0]->_wait;
		1952	}
1520		1953
1521	Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak};	1954	$_[0]{_ae_croak}
1522	wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0]	1955	and Carp::croak $_[0]{_ae_croak};
		1956
		1957	wantarray
		1958	? @{ $_[0]{_ae_sent} }
		1959	: $_[0]{_ae_sent}[0]
1523	}	1960	}
1524		1961
1525	sub cb {	1962	sub cb {
1526	$_[0]{_ae_cb} = $_[1] if @_ > 1;	1963	my $cv = shift;
		1964
		1965	@_
		1966	and $cv->{_ae_cb} = shift
		1967	and $cv->{_ae_sent}
		1968	and (delete $cv->{_ae_cb})->($cv);
		1969
1527	$_[0]{_ae_cb}	1970	$cv->{_ae_cb}
1528	}	1971	}
1529		1972
1530	sub begin {	1973	sub begin {
1531	++$_[0]{_ae_counter};	1974	++$_[0]{_ae_counter};
1532	$_[0]{_ae_end_cb} = $_[1] if @_ > 1;	1975	$_[0]{_ae_end_cb} = $_[1] if @_ > 1;
…		…
1537	&{ $_[0]{_ae_end_cb} || sub { $_[0]->send } };	1980	&{ $_[0]{_ae_end_cb} || sub { $_[0]->send } };
1538	}	1981	}
1539		1982
1540	# undocumented/compatibility with pre-3.4	1983	# undocumented/compatibility with pre-3.4
1541	*broadcast = \&send;	1984	*broadcast = \&send;
1542	*wait = \&_wait;	1985	*wait = \&recv;
1543		1986
1544	=head1 ERROR AND EXCEPTION HANDLING	1987	=head1 ERROR AND EXCEPTION HANDLING
1545		1988
1546	In general, AnyEvent does not do any error handling - it relies on the	1989	In general, AnyEvent does not do any error handling - it relies on the
1547	caller to do that if required. The L<AnyEvent::Strict> module (see also	1990	caller to do that if required. The L<AnyEvent::Strict> module (see also
…		…
1559	$Event/EV::DIED->() >>, L<Glib> uses C<< install_exception_handler >> and	2002	$Event/EV::DIED->() >>, L<Glib> uses C<< install_exception_handler >> and
1560	so on.	2003	so on.
1561		2004
1562	=head1 ENVIRONMENT VARIABLES	2005	=head1 ENVIRONMENT VARIABLES
1563		2006
1564	The following environment variables are used by this module or its	2007	AnyEvent supports a number of environment variables that tune the
1565	submodules.	2008	runtime behaviour. They are usually evaluated when AnyEvent is
		2009	loaded, initialised, or a submodule that uses them is loaded. Many of
		2010	them also cause AnyEvent to load additional modules - for example,
		2011	C<PERL_ANYEVENT_DEBUG_WRAP> causes the L<AnyEvent::Debug> module to be
		2012	loaded.
1566		2013
1567	Note that AnyEvent will remove I<all> environment variables starting with	2014	All the environment variables documented here start with
1568	C<PERL_ANYEVENT_> from C<%ENV> when it is loaded while taint mode is	2015	C<PERL_ANYEVENT_>, which is what AnyEvent considers its own
1569	enabled.	2016	namespace. Other modules are encouraged (but by no means required) to use
		2017	C<PERL_ANYEVENT_SUBMODULE> if they have registered the AnyEvent::Submodule
		2018	namespace on CPAN, for any submodule. For example, L<AnyEvent::HTTP> could
		2019	be expected to use C<PERL_ANYEVENT_HTTP_PROXY> (it should not access env
		2020	variables starting with C<AE_>, see below).
		2021
		2022	All variables can also be set via the C<AE_> prefix, that is, instead
		2023	of setting C<PERL_ANYEVENT_VERBOSE> you can also set C<AE_VERBOSE>. In
		2024	case there is a clash btween anyevent and another program that uses
		2025	C<AE_something> you can set the corresponding C<PERL_ANYEVENT_something>
		2026	variable to the empty string, as those variables take precedence.
		2027
		2028	When AnyEvent is first loaded, it copies all C<AE_xxx> env variables
		2029	to their C<PERL_ANYEVENT_xxx> counterpart unless that variable already
		2030	exists. If taint mode is on, then AnyEvent will remove I<all> environment
		2031	variables starting with C<PERL_ANYEVENT_> from C<%ENV> (or replace them
		2032	with C<undef> or the empty string, if the corresaponding C<AE_> variable
		2033	is set).
		2034
		2035	The exact algorithm is currently:
		2036
		2037	1. if taint mode enabled, delete all PERL_ANYEVENT_xyz variables from %ENV
		2038	2. copy over AE_xyz to PERL_ANYEVENT_xyz unless the latter alraedy exists
		2039	3. if taint mode enabled, set all PERL_ANYEVENT_xyz variables to undef.
		2040
		2041	This ensures that child processes will not see the C<AE_> variables.
		2042
		2043	The following environment variables are currently known to AnyEvent:
1570		2044
1571	=over 4	2045	=over 4
1572		2046
1573	=item C<PERL_ANYEVENT_VERBOSE>	2047	=item C<PERL_ANYEVENT_VERBOSE>
1574		2048
1575	By default, AnyEvent will be completely silent except in fatal	2049	By default, AnyEvent will only log messages with loglevel C<3>
1576	conditions. You can set this environment variable to make AnyEvent more	2050	(C<critical>) or higher (see L<AnyEvent::Log>). You can set this
		2051	environment variable to a numerical loglevel to make AnyEvent more (or
1577	talkative.	2052	less) talkative.
1578		2053
		2054	If you want to do more than just set the global logging level
		2055	you should have a look at C<PERL_ANYEVENT_LOG>, which allows much more
		2056	complex specifications.
		2057
		2058	When set to C<0> (C<off>), then no messages whatsoever will be logged with
		2059	the default logging settings.
		2060
1579	When set to C<1> or higher, causes AnyEvent to warn about unexpected	2061	When set to C<5> or higher (C<warn>), causes AnyEvent to warn about
1580	conditions, such as not being able to load the event model specified by	2062	unexpected conditions, such as not being able to load the event model
1581	C<PERL_ANYEVENT_MODEL>.	2063	specified by C<PERL_ANYEVENT_MODEL>, or a guard callback throwing an
		2064	exception - this is the minimum recommended level.
1582		2065
1583	When set to C<2> or higher, cause AnyEvent to report to STDERR which event	2066	When set to C<7> or higher (info), cause AnyEvent to report which event model it
1584	model it chooses.	2067	chooses.
1585		2068
1586	When set to C<8> or higher, then AnyEvent will report extra information on	2069	When set to C<8> or higher (debug), then AnyEvent will report extra information on
1587	which optional modules it loads and how it implements certain features.	2070	which optional modules it loads and how it implements certain features.
		2071
		2072	=item C<PERL_ANYEVENT_LOG>
		2073
		2074	Accepts rather complex logging specifications. For example, you could log
		2075	all C<debug> messages of some module to stderr, warnings and above to
		2076	stderr, and errors and above to syslog, with:
		2077
		2078	PERL_ANYEVENT_LOG=Some::Module=debug,+log:filter=warn,+%syslog:%syslog=error,syslog
		2079
		2080	For the rather extensive details, see L<AnyEvent::Log>.
		2081
		2082	This variable is evaluated when AnyEvent (or L<AnyEvent::Log>) is loaded,
		2083	so will take effect even before AnyEvent has initialised itself.
		2084
		2085	Note that specifying this environment variable causes the L<AnyEvent::Log>
		2086	module to be loaded, while C<PERL_ANYEVENT_VERBOSE> does not, so only
		2087	using the latter saves a few hundred kB of memory until the first message
		2088	is being logged.
1588		2089
1589	=item C<PERL_ANYEVENT_STRICT>	2090	=item C<PERL_ANYEVENT_STRICT>
1590		2091
1591	AnyEvent does not do much argument checking by default, as thorough	2092	AnyEvent does not do much argument checking by default, as thorough
1592	argument checking is very costly. Setting this variable to a true value	2093	argument checking is very costly. Setting this variable to a true value
…		…
1594	check the arguments passed to most method calls. If it finds any problems,	2095	check the arguments passed to most method calls. If it finds any problems,
1595	it will croak.	2096	it will croak.
1596		2097
1597	In other words, enables "strict" mode.	2098	In other words, enables "strict" mode.
1598		2099
1599	Unlike C<use strict> (or it's modern cousin, C<< use L<common::sense>	2100	Unlike C<use strict> (or its modern cousin, C<< use L<common::sense>
1600	>>, it is definitely recommended to keep it off in production. Keeping	2101	>>, it is definitely recommended to keep it off in production. Keeping
1601	C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs	2102	C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs
1602	can be very useful, however.	2103	can be very useful, however.
1603		2104
		2105	=item C<PERL_ANYEVENT_DEBUG_SHELL>
		2106
		2107	If this env variable is set, then its contents will be interpreted by
		2108	C<AnyEvent::Socket::parse_hostport> (after replacing every occurance of
		2109	C<$$> by the process pid) and an C<AnyEvent::Debug::shell> is bound on
		2110	that port. The shell object is saved in C<$AnyEvent::Debug::SHELL>.
		2111
		2112	This happens when the first watcher is created.
		2113
		2114	For example, to bind a debug shell on a unix domain socket in
		2115	F<< /tmp/debug<pid>.sock >>, you could use this:
		2116
		2117	PERL_ANYEVENT_DEBUG_SHELL=/tmp/debug\$\$.sock perlprog
		2118
		2119	Note that creating sockets in F</tmp> is very unsafe on multiuser
		2120	systems.
		2121
		2122	=item C<PERL_ANYEVENT_DEBUG_WRAP>
		2123
		2124	Can be set to C<0>, C<1> or C<2> and enables wrapping of all watchers for
		2125	debugging purposes. See C<AnyEvent::Debug::wrap> for details.
		2126
1604	=item C<PERL_ANYEVENT_MODEL>	2127	=item C<PERL_ANYEVENT_MODEL>
1605		2128
1606	This can be used to specify the event model to be used by AnyEvent, before	2129	This can be used to specify the event model to be used by AnyEvent, before
1607	auto detection and -probing kicks in. It must be a string consisting	2130	auto detection and -probing kicks in.
1608	entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended	2131
		2132	It normally is a string consisting entirely of ASCII letters (e.g. C<EV>
		2133	or C<IOAsync>). The string C<AnyEvent::Impl::> gets prepended and the
1609	and the resulting module name is loaded and if the load was successful,	2134	resulting module name is loaded and - if the load was successful - used as
1610	used as event model. If it fails to load AnyEvent will proceed with	2135	event model backend. If it fails to load then AnyEvent will proceed with
1611	auto detection and -probing.	2136	auto detection and -probing.
1612		2137
1613	This functionality might change in future versions.	2138	If the string ends with C<::> instead (e.g. C<AnyEvent::Impl::EV::>) then
		2139	nothing gets prepended and the module name is used as-is (hint: C<::> at
		2140	the end of a string designates a module name and quotes it appropriately).
1614		2141
1615	For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you	2142	For example, to force the pure perl model (L<AnyEvent::Loop::Perl>) you
1616	could start your program like this:	2143	could start your program like this:
1617		2144
1618	PERL_ANYEVENT_MODEL=Perl perl ...	2145	PERL_ANYEVENT_MODEL=Perl perl ...
1619		2146
1620	=item C<PERL_ANYEVENT_PROTOCOLS>	2147	=item C<PERL_ANYEVENT_PROTOCOLS>
…		…
1636	but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4>	2163	but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4>
1637	- only support IPv4, never try to resolve or contact IPv6	2164	- only support IPv4, never try to resolve or contact IPv6
1638	addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or	2165	addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or
1639	IPv6, but prefer IPv6 over IPv4.	2166	IPv6, but prefer IPv6 over IPv4.
1640		2167
		2168	=item C<PERL_ANYEVENT_HOSTS>
		2169
		2170	This variable, if specified, overrides the F</etc/hosts> file used by
		2171	L<AnyEvent::Socket>C<::resolve_sockaddr>, i.e. hosts aliases will be read
		2172	from that file instead.
		2173
1641	=item C<PERL_ANYEVENT_EDNS0>	2174	=item C<PERL_ANYEVENT_EDNS0>
1642		2175
1643	Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension	2176	Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension for
1644	for DNS. This extension is generally useful to reduce DNS traffic, but	2177	DNS. This extension is generally useful to reduce DNS traffic, especially
1645	some (broken) firewalls drop such DNS packets, which is why it is off by	2178	when DNSSEC is involved, but some (broken) firewalls drop such DNS
1646	default.	2179	packets, which is why it is off by default.
1647		2180
1648	Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce	2181	Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce
1649	EDNS0 in its DNS requests.	2182	EDNS0 in its DNS requests.
1650		2183
1651	=item C<PERL_ANYEVENT_MAX_FORKS>	2184	=item C<PERL_ANYEVENT_MAX_FORKS>
…		…
1659	resolver - this is the maximum number of parallel DNS requests that are	2192	resolver - this is the maximum number of parallel DNS requests that are
1660	sent to the DNS server.	2193	sent to the DNS server.
1661		2194
1662	=item C<PERL_ANYEVENT_RESOLV_CONF>	2195	=item C<PERL_ANYEVENT_RESOLV_CONF>
1663		2196
1664	The file to use instead of F</etc/resolv.conf> (or OS-specific	2197	The absolute path to a F<resolv.conf>-style file to use instead of
1665	configuration) in the default resolver. When set to the empty string, no	2198	F</etc/resolv.conf> (or the OS-specific configuration) in the default
1666	default config will be used.	2199	resolver, or the empty string to select the default configuration.
1667		2200
1668	=item C<PERL_ANYEVENT_CA_FILE>, C<PERL_ANYEVENT_CA_PATH>.	2201	=item C<PERL_ANYEVENT_CA_FILE>, C<PERL_ANYEVENT_CA_PATH>.
1669		2202
1670	When neither C<ca_file> nor C<ca_path> was specified during	2203	When neither C<ca_file> nor C<ca_path> was specified during
1671	L<AnyEvent::TLS> context creation, and either of these environment	2204	L<AnyEvent::TLS> context creation, and either of these environment
1672	variables exist, they will be used to specify CA certificate locations	2205	variables are nonempty, they will be used to specify CA certificate
1673	instead of a system-dependent default.	2206	locations instead of a system-dependent default.
1674		2207
1675	=item C<PERL_ANYEVENT_AVOID_GUARD> and C<PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT>	2208	=item C<PERL_ANYEVENT_AVOID_GUARD> and C<PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT>
1676		2209
1677	When these are set to C<1>, then the respective modules are not	2210	When these are set to C<1>, then the respective modules are not
1678	loaded. Mostly good for testing AnyEvent itself.	2211	loaded. Mostly good for testing AnyEvent itself.
…		…
1741	warn "read: $input\n"; # output what has been read	2274	warn "read: $input\n"; # output what has been read
1742	$cv->send if $input =~ /^q/i; # quit program if /^q/i	2275	$cv->send if $input =~ /^q/i; # quit program if /^q/i
1743	},	2276	},
1744	);	2277	);
1745		2278
1746	my $time_watcher; # can only be used once
1747
1748	sub new_timer {
1749	$timer = AnyEvent->timer (after => 1, cb => sub {	2279	my $time_watcher = AnyEvent->timer (after => 1, interval => 1, cb => sub {
1750	warn "timeout\n"; # print 'timeout' about every second	2280	warn "timeout\n"; # print 'timeout' at most every second
1751	&new_timer; # and restart the time
1752	});	2281	});
1753	}
1754
1755	new_timer; # create first timer
1756		2282
1757	$cv->recv; # wait until user enters /^q/i	2283	$cv->recv; # wait until user enters /^q/i
1758		2284
1759	=head1 REAL-WORLD EXAMPLE	2285	=head1 REAL-WORLD EXAMPLE
1760		2286
…		…
1833		2359
1834	The actual code goes further and collects all errors (C<die>s, exceptions)	2360	The actual code goes further and collects all errors (C<die>s, exceptions)
1835	that occurred during request processing. The C<result> method detects	2361	that occurred during request processing. The C<result> method detects
1836	whether an exception as thrown (it is stored inside the $txn object)	2362	whether an exception as thrown (it is stored inside the $txn object)
1837	and just throws the exception, which means connection errors and other	2363	and just throws the exception, which means connection errors and other
1838	problems get reported tot he code that tries to use the result, not in a	2364	problems get reported to the code that tries to use the result, not in a
1839	random callback.	2365	random callback.
1840		2366
1841	All of this enables the following usage styles:	2367	All of this enables the following usage styles:
1842		2368
1843	1. Blocking:	2369	1. Blocking:
…		…
1891	through AnyEvent. The benchmark creates a lot of timers (with a zero	2417	through AnyEvent. The benchmark creates a lot of timers (with a zero
1892	timeout) and I/O watchers (watching STDOUT, a pty, to become writable,	2418	timeout) and I/O watchers (watching STDOUT, a pty, to become writable,
1893	which it is), lets them fire exactly once and destroys them again.	2419	which it is), lets them fire exactly once and destroys them again.
1894		2420
1895	Source code for this benchmark is found as F<eg/bench> in the AnyEvent	2421	Source code for this benchmark is found as F<eg/bench> in the AnyEvent
1896	distribution.	2422	distribution. It uses the L<AE> interface, which makes a real difference
		2423	for the EV and Perl backends only.
1897		2424
1898	=head3 Explanation of the columns	2425	=head3 Explanation of the columns
1899		2426
1900	I<watcher> is the number of event watchers created/destroyed. Since	2427	I<watcher> is the number of event watchers created/destroyed. Since
1901	different event models feature vastly different performances, each event	2428	different event models feature vastly different performances, each event
…		…
1922	watcher.	2449	watcher.
1923		2450
1924	=head3 Results	2451	=head3 Results
1925		2452
1926	name watchers bytes create invoke destroy comment	2453	name watchers bytes create invoke destroy comment
1927	EV/EV 400000 224 0.47 0.35 0.27 EV native interface	2454	EV/EV 100000 223 0.47 0.43 0.27 EV native interface
1928	EV/Any 100000 224 2.88 0.34 0.27 EV + AnyEvent watchers	2455	EV/Any 100000 223 0.48 0.42 0.26 EV + AnyEvent watchers
1929	CoroEV/Any 100000 224 2.85 0.35 0.28 coroutines + Coro::Signal	2456	Coro::EV/Any 100000 223 0.47 0.42 0.26 coroutines + Coro::Signal
1930	Perl/Any 100000 452 4.13 0.73 0.95 pure perl implementation	2457	Perl/Any 100000 431 2.70 0.74 0.92 pure perl implementation
1931	Event/Event 16000 517 32.20 31.80 0.81 Event native interface	2458	Event/Event 16000 516 31.16 31.84 0.82 Event native interface
1932	Event/Any 16000 590 35.85 31.55 1.06 Event + AnyEvent watchers	2459	Event/Any 16000 1203 42.61 34.79 1.80 Event + AnyEvent watchers
1933	IOAsync/Any 16000 989 38.10 32.77 11.13 via IO::Async::Loop::IO_Poll	2460	IOAsync/Any 16000 1911 41.92 27.45 16.81 via IO::Async::Loop::IO_Poll
1934	IOAsync/Any 16000 990 37.59 29.50 10.61 via IO::Async::Loop::Epoll	2461	IOAsync/Any 16000 1726 40.69 26.37 15.25 via IO::Async::Loop::Epoll
1935	Glib/Any 16000 1357 102.33 12.31 51.00 quadratic behaviour	2462	Glib/Any 16000 1118 89.00 12.57 51.17 quadratic behaviour
1936	Tk/Any 2000 1860 27.20 66.31 14.00 SEGV with >> 2000 watchers	2463	Tk/Any 2000 1346 20.96 10.75 8.00 SEGV with >> 2000 watchers
1937	POE/Event 2000 6328 109.99 751.67 14.02 via POE::Loop::Event	2464	POE/Any 2000 6951 108.97 795.32 14.24 via POE::Loop::Event
1938	POE/Select 2000 6027 94.54 809.13 579.80 via POE::Loop::Select	2465	POE/Any 2000 6648 94.79 774.40 575.51 via POE::Loop::Select
1939		2466
1940	=head3 Discussion	2467	=head3 Discussion
1941		2468
1942	The benchmark does I<not> measure scalability of the event loop very	2469	The benchmark does I<not> measure scalability of the event loop very
1943	well. For example, a select-based event loop (such as the pure perl one)	2470	well. For example, a select-based event loop (such as the pure perl one)
…		…
1955	benchmark machine, handling an event takes roughly 1600 CPU cycles with	2482	benchmark machine, handling an event takes roughly 1600 CPU cycles with
1956	EV, 3100 CPU cycles with AnyEvent's pure perl loop and almost 3000000 CPU	2483	EV, 3100 CPU cycles with AnyEvent's pure perl loop and almost 3000000 CPU
1957	cycles with POE.	2484	cycles with POE.
1958		2485
1959	C<EV> is the sole leader regarding speed and memory use, which are both	2486	C<EV> is the sole leader regarding speed and memory use, which are both
1960	maximal/minimal, respectively. Even when going through AnyEvent, it uses	2487	maximal/minimal, respectively. When using the L<AE> API there is zero
		2488	overhead (when going through the AnyEvent API create is about 5-6 times
		2489	slower, with other times being equal, so still uses far less memory than
1961	far less memory than any other event loop and is still faster than Event	2490	any other event loop and is still faster than Event natively).
1962	natively.
1963		2491
1964	The pure perl implementation is hit in a few sweet spots (both the	2492	The pure perl implementation is hit in a few sweet spots (both the
1965	constant timeout and the use of a single fd hit optimisations in the perl	2493	constant timeout and the use of a single fd hit optimisations in the perl
1966	interpreter and the backend itself). Nevertheless this shows that it	2494	interpreter and the backend itself). Nevertheless this shows that it
1967	adds very little overhead in itself. Like any select-based backend its	2495	adds very little overhead in itself. Like any select-based backend its
…		…
2015	(even when used without AnyEvent), but most event loops have acceptable	2543	(even when used without AnyEvent), but most event loops have acceptable
2016	performance with or without AnyEvent.	2544	performance with or without AnyEvent.
2017		2545
2018	=item * The overhead AnyEvent adds is usually much smaller than the overhead of	2546	=item * The overhead AnyEvent adds is usually much smaller than the overhead of
2019	the actual event loop, only with extremely fast event loops such as EV	2547	the actual event loop, only with extremely fast event loops such as EV
2020	adds AnyEvent significant overhead.	2548	does AnyEvent add significant overhead.
2021		2549
2022	=item * You should avoid POE like the plague if you want performance or	2550	=item * You should avoid POE like the plague if you want performance or
2023	reasonable memory usage.	2551	reasonable memory usage.
2024		2552
2025	=back	2553	=back
…		…
2041	In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100	2569	In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100
2042	(1%) are active. This mirrors the activity of large servers with many	2570	(1%) are active. This mirrors the activity of large servers with many
2043	connections, most of which are idle at any one point in time.	2571	connections, most of which are idle at any one point in time.
2044		2572
2045	Source code for this benchmark is found as F<eg/bench2> in the AnyEvent	2573	Source code for this benchmark is found as F<eg/bench2> in the AnyEvent
2046	distribution.	2574	distribution. It uses the L<AE> interface, which makes a real difference
		2575	for the EV and Perl backends only.
2047		2576
2048	=head3 Explanation of the columns	2577	=head3 Explanation of the columns
2049		2578
2050	I<sockets> is the number of sockets, and twice the number of "servers" (as	2579	I<sockets> is the number of sockets, and twice the number of "servers" (as
2051	each server has a read and write socket end).	2580	each server has a read and write socket end).
…		…
2059	a new one that moves the timeout into the future.	2588	a new one that moves the timeout into the future.
2060		2589
2061	=head3 Results	2590	=head3 Results
2062		2591
2063	name sockets create request	2592	name sockets create request
2064	EV 20000 69.01 11.16	2593	EV 20000 62.66 7.99
2065	Perl 20000 73.32 35.87	2594	Perl 20000 68.32 32.64
2066	IOAsync 20000 157.00 98.14 epoll	2595	IOAsync 20000 174.06 101.15 epoll
2067	IOAsync 20000 159.31 616.06 poll	2596	IOAsync 20000 174.67 610.84 poll
2068	Event 20000 212.62 257.32	2597	Event 20000 202.69 242.91
2069	Glib 20000 651.16 1896.30	2598	Glib 20000 557.01 1689.52
2070	POE 20000 349.67 12317.24 uses POE::Loop::Event	2599	POE 20000 341.54 12086.32 uses POE::Loop::Event
2071		2600
2072	=head3 Discussion	2601	=head3 Discussion
2073		2602
2074	This benchmark I<does> measure scalability and overall performance of the	2603	This benchmark I<does> measure scalability and overall performance of the
2075	particular event loop.	2604	particular event loop.
…		…
2201	As you can see, the AnyEvent + EV combination even beats the	2730	As you can see, the AnyEvent + EV combination even beats the
2202	hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl	2731	hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl
2203	backend easily beats IO::Lambda and POE.	2732	backend easily beats IO::Lambda and POE.
2204		2733
2205	And even the 100% non-blocking version written using the high-level (and	2734	And even the 100% non-blocking version written using the high-level (and
2206	slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda by a	2735	slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda
2207	large margin, even though it does all of DNS, tcp-connect and socket I/O	2736	higher level ("unoptimised") abstractions by a large margin, even though
2208	in a non-blocking way.	2737	it does all of DNS, tcp-connect and socket I/O in a non-blocking way.
2209		2738
2210	The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and	2739	The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and
2211	F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are	2740	F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are
2212	part of the IO::lambda distribution and were used without any changes.	2741	part of the IO::Lambda distribution and were used without any changes.
2213		2742
2214		2743
2215	=head1 SIGNALS	2744	=head1 SIGNALS
2216		2745
2217	AnyEvent currently installs handlers for these signals:	2746	AnyEvent currently installs handlers for these signals:
…		…
2254	unless defined $SIG{PIPE};	2783	unless defined $SIG{PIPE};
2255		2784
2256	=head1 RECOMMENDED/OPTIONAL MODULES	2785	=head1 RECOMMENDED/OPTIONAL MODULES
2257		2786
2258	One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and	2787	One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and
2259	it's built-in modules) are required to use it.	2788	its built-in modules) are required to use it.
2260		2789
2261	That does not mean that AnyEvent won't take advantage of some additional	2790	That does not mean that AnyEvent won't take advantage of some additional
2262	modules if they are installed.	2791	modules if they are installed.
2263		2792
2264	This section epxlains which additional modules will be used, and how they	2793	This section explains which additional modules will be used, and how they
2265	affect AnyEvent's operetion.	2794	affect AnyEvent's operation.
2266		2795
2267	=over 4	2796	=over 4
2268		2797
2269	=item L<Async::Interrupt>	2798	=item L<Async::Interrupt>
2270		2799
2271	This slightly arcane module is used to implement fast signal handling: To	2800	This slightly arcane module is used to implement fast signal handling: To
2272	my knowledge, there is no way to do completely race-free and quick	2801	my knowledge, there is no way to do completely race-free and quick
2273	signal handling in pure perl. To ensure that signals still get	2802	signal handling in pure perl. To ensure that signals still get
2274	delivered, AnyEvent will start an interval timer to wake up perl (and	2803	delivered, AnyEvent will start an interval timer to wake up perl (and
2275	catch the signals) with soemd elay (default is 10 seconds, look for	2804	catch the signals) with some delay (default is 10 seconds, look for
2276	C<$AnyEvent::MAX_SIGNAL_LATENCY>).	2805	C<$AnyEvent::MAX_SIGNAL_LATENCY>).
2277		2806
2278	If this module is available, then it will be used to implement signal	2807	If this module is available, then it will be used to implement signal
2279	catching, which means that signals will not be delayed, and the event loop	2808	catching, which means that signals will not be delayed, and the event loop
2280	will not be interrupted regularly, which is more efficient (And good for	2809	will not be interrupted regularly, which is more efficient (and good for
2281	battery life on laptops).	2810	battery life on laptops).
2282		2811
2283	This affects not just the pure-perl event loop, but also other event loops	2812	This affects not just the pure-perl event loop, but also other event loops
2284	that have no signal handling on their own (e.g. Glib, Tk, Qt).	2813	that have no signal handling on their own (e.g. Glib, Tk, Qt).
		2814
		2815	Some event loops (POE, Event, Event::Lib) offer signal watchers natively,
		2816	and either employ their own workarounds (POE) or use AnyEvent's workaround
		2817	(using C<$AnyEvent::MAX_SIGNAL_LATENCY>). Installing L<Async::Interrupt>
		2818	does nothing for those backends.
2285		2819
2286	=item L<EV>	2820	=item L<EV>
2287		2821
2288	This module isn't really "optional", as it is simply one of the backend	2822	This module isn't really "optional", as it is simply one of the backend
2289	event loops that AnyEvent can use. However, it is simply the best event	2823	event loops that AnyEvent can use. However, it is simply the best event
…		…
2292	automatic timer adjustments even when no monotonic clock is available,	2826	automatic timer adjustments even when no monotonic clock is available,
2293	can take avdantage of advanced kernel interfaces such as C<epoll> and	2827	can take avdantage of advanced kernel interfaces such as C<epoll> and
2294	C<kqueue>, and is the fastest backend I<by far>. You can even embed	2828	C<kqueue>, and is the fastest backend I<by far>. You can even embed
2295	L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>).	2829	L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>).
2296		2830
		2831	If you only use backends that rely on another event loop (e.g. C<Tk>),
		2832	then this module will do nothing for you.
		2833
2297	=item L<Guard>	2834	=item L<Guard>
2298		2835
2299	The guard module, when used, will be used to implement	2836	The guard module, when used, will be used to implement
2300	C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a	2837	C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a
2301	lot less memory), but otherwise doesn't affect guard operation much. It is	2838	lot less memory), but otherwise doesn't affect guard operation much. It is
2302	purely used for performance.	2839	purely used for performance.
2303		2840
2304	=item L<JSON> and L<JSON::XS>	2841	=item L<JSON> and L<JSON::XS>
2305		2842
2306	This module is required when you want to read or write JSON data via	2843	One of these modules is required when you want to read or write JSON data
2307	L<AnyEvent::Handle>. It is also written in pure-perl, but can take	2844	via L<AnyEvent::Handle>. L<JSON> is also written in pure-perl, but can take
2308	advantage of the ulta-high-speed L<JSON::XS> module when it is installed.	2845	advantage of the ultra-high-speed L<JSON::XS> module when it is installed.
2309
2310	In fact, L<AnyEvent::Handle> will use L<JSON::XS> by default if it is
2311	installed.
2312		2846
2313	=item L<Net::SSLeay>	2847	=item L<Net::SSLeay>
2314		2848
2315	Implementing TLS/SSL in Perl is certainly interesting, but not very	2849	Implementing TLS/SSL in Perl is certainly interesting, but not very
2316	worthwhile: If this module is installed, then L<AnyEvent::Handle> (with	2850	worthwhile: If this module is installed, then L<AnyEvent::Handle> (with
2317	the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL.	2851	the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL.
2318		2852
2319	=item L<Time::HiRes>	2853	=item L<Time::HiRes>
2320		2854
2321	This module is part of perl since release 5.008. It will be used when the	2855	This module is part of perl since release 5.008. It will be used when the
2322	chosen event library does not come with a timing source on it's own. The	2856	chosen event library does not come with a timing source of its own. The
2323	pure-perl event loop (L<AnyEvent::Impl::Perl>) will additionally use it to	2857	pure-perl event loop (L<AnyEvent::Loop>) will additionally load it to
2324	try to use a monotonic clock for timing stability.	2858	try to use a monotonic clock for timing stability.
2325		2859
2326	=back	2860	=back
2327		2861
2328		2862
2329	=head1 FORK	2863	=head1 FORK
2330		2864
2331	Most event libraries are not fork-safe. The ones who are usually are	2865	Most event libraries are not fork-safe. The ones who are usually are
2332	because they rely on inefficient but fork-safe C<select> or C<poll>	2866	because they rely on inefficient but fork-safe C<select> or C<poll> calls
2333	calls. Only L<EV> is fully fork-aware.	2867	- higher performance APIs such as BSD's kqueue or the dreaded Linux epoll
		2868	are usually badly thought-out hacks that are incompatible with fork in
		2869	one way or another. Only L<EV> is fully fork-aware and ensures that you
		2870	continue event-processing in both parent and child (or both, if you know
		2871	what you are doing).
		2872
		2873	This means that, in general, you cannot fork and do event processing in
		2874	the child if the event library was initialised before the fork (which
		2875	usually happens when the first AnyEvent watcher is created, or the library
		2876	is loaded).
2334		2877
2335	If you have to fork, you must either do so I<before> creating your first	2878	If you have to fork, you must either do so I<before> creating your first
2336	watcher OR you must not use AnyEvent at all in the child OR you must do	2879	watcher OR you must not use AnyEvent at all in the child OR you must do
2337	something completely out of the scope of AnyEvent.	2880	something completely out of the scope of AnyEvent.
		2881
		2882	The problem of doing event processing in the parent I<and> the child
		2883	is much more complicated: even for backends that I<are> fork-aware or
		2884	fork-safe, their behaviour is not usually what you want: fork clones all
		2885	watchers, that means all timers, I/O watchers etc. are active in both
		2886	parent and child, which is almost never what you want. USing C<exec>
		2887	to start worker children from some kind of manage rprocess is usually
		2888	preferred, because it is much easier and cleaner, at the expense of having
		2889	to have another binary.
2338		2890
2339		2891
2340	=head1 SECURITY CONSIDERATIONS	2892	=head1 SECURITY CONSIDERATIONS
2341		2893
2342	AnyEvent can be forced to load any event model via	2894	AnyEvent can be forced to load any event model via
…		…
2372	pronounced).	2924	pronounced).
2373		2925
2374		2926
2375	=head1 SEE ALSO	2927	=head1 SEE ALSO
2376		2928
2377	Utility functions: L<AnyEvent::Util>.	2929	Tutorial/Introduction: L<AnyEvent::Intro>.
2378		2930
2379	Event modules: L<EV>, L<EV::Glib>, L<Glib::EV>, L<Event>, L<Glib::Event>,	2931	FAQ: L<AnyEvent::FAQ>.
2380	L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.	2932
		2933	Utility functions: L<AnyEvent::Util> (misc. grab-bag), L<AnyEvent::Log>
		2934	(simply logging).
		2935
		2936	Development/Debugging: L<AnyEvent::Strict> (stricter checking),
		2937	L<AnyEvent::Debug> (interactive shell, watcher tracing).
		2938
		2939	Supported event modules: L<AnyEvent::Loop>, L<EV>, L<EV::Glib>,
		2940	L<Glib::EV>, L<Event>, L<Glib::Event>, L<Glib>, L<Tk>, L<Event::Lib>,
		2941	L<Qt>, L<POE>, L<FLTK>.
2381		2942
2382	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,	2943	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,
2383	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,	2944	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,
2384	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,	2945	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,
2385	L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>.	2946	L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>, L<Anyevent::Impl::Irssi>,
		2947	L<AnyEvent::Impl::FLTK>.
2386		2948
2387	Non-blocking file handles, sockets, TCP clients and	2949	Non-blocking handles, pipes, stream sockets, TCP clients and
2388	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.	2950	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.
2389		2951
2390	Asynchronous DNS: L<AnyEvent::DNS>.	2952	Asynchronous DNS: L<AnyEvent::DNS>.
2391		2953
2392	Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>,	2954	Thread support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>.
2393	L<Coro::Event>,
2394		2955
2395	Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::XMPP>,	2956	Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::IRC>,
2396	L<AnyEvent::HTTP>.	2957	L<AnyEvent::HTTP>.
2397		2958
2398		2959
2399	=head1 AUTHOR	2960	=head1 AUTHOR
2400		2961

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