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Revision 1.383 by root, Fri Sep 2 04:41:16 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
1061	our $AUTOLOAD;
1062	our @ISA;	1242	our @ISA;
1063
1064	our @REGISTRY;	1243	our @REGISTRY;
1065
1066	our $WIN32;
1067
1068	our $VERBOSE;	1244	our $VERBOSE;
		1245	our $MAX_SIGNAL_LATENCY = 10;
		1246	our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred
1069		1247
1070	BEGIN {	1248	BEGIN {
1071	eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }";	1249	require "AnyEvent/constants.pl";
		1250
1072	eval "sub TAINT(){ " . (${^TAINT}*1) . " }";	1251	eval "sub TAINT (){" . (${^TAINT}*1) . "}";
1073		1252
1074	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}	1253	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}
1075	if ${^TAINT};	1254	if ${^TAINT};
1076		1255
1077	$VERBOSE = $ENV{PERL_ANYEVENT_VERBOSE}*1;	1256	$ENV{"PERL_ANYEVENT_$_"} = $ENV{"AE_$_"}
		1257	for grep s/^AE_// && !exists $ENV{"PERL_ANYEVENT_$_"}, keys %ENV;
1078		1258
1079	}	1259	@ENV{grep /^PERL_ANYEVENT_/, keys %ENV} = ()
		1260	if ${^TAINT};
1080		1261
1081	our $MAX_SIGNAL_LATENCY = 10;	1262	# $ENV{PERL_ANYEVENT_xxx} now valid
1082		1263
1083	our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred	1264	$VERBOSE = length $ENV{PERL_ANYEVENT_VERBOSE} ? $ENV{PERL_ANYEVENT_VERBOSE}*1 : 3;
1084		1265
1085	{
1086	my $idx;	1266	my $idx;
1087	$PROTOCOL{$_} = ++$idx	1267	$PROTOCOL{$_} = ++$idx
1088	for reverse split /\s*,\s*/,	1268	for reverse split /\s*,\s*/,
1089	$ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";	1269	$ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";
1090	}	1270	}
1091		1271
		1272	our @post_detect;
		1273
		1274	sub post_detect(&) {
		1275	my ($cb) = @_;
		1276
		1277	push @post_detect, $cb;
		1278
		1279	defined wantarray
		1280	? bless \$cb, "AnyEvent::Util::postdetect"
		1281	: ()
		1282	}
		1283
		1284	sub AnyEvent::Util::postdetect::DESTROY {
		1285	@post_detect = grep $_ != ${$_[0]}, @post_detect;
		1286	}
		1287
		1288	our $POSTPONE_W;
		1289	our @POSTPONE;
		1290
		1291	sub _postpone_exec {
		1292	undef $POSTPONE_W;
		1293
		1294	&{ shift @POSTPONE }
		1295	while @POSTPONE;
		1296	}
		1297
		1298	sub postpone(&) {
		1299	push @POSTPONE, shift;
		1300
		1301	$POSTPONE_W ||= AE::timer (0, 0, \&_postpone_exec);
		1302
		1303	()
		1304	}
		1305
		1306	sub log($$;@) {
		1307	# only load the big bloated module when we actually are about to log something
		1308	if ($_[0] <= $VERBOSE) { # also catches non-numeric levels(!)
		1309	require AnyEvent::Log;
		1310	# AnyEvent::Log overwrites this function
		1311	goto &log;
		1312	}
		1313
		1314	0 # not logged
		1315	}
		1316
		1317	if (length $ENV{PERL_ANYEVENT_LOG}) {
		1318	require AnyEvent::Log; # AnyEvent::Log does the thing for us
		1319	}
		1320
1092	my @models = (	1321	our @models = (
1093	[EV:: => AnyEvent::Impl::EV::],	1322	[EV:: => AnyEvent::Impl::EV:: , 1],
1094	[Event:: => AnyEvent::Impl::Event::],	1323	[AnyEvent::Loop:: => AnyEvent::Impl::Perl:: , 1],
1095	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::],
1096	# everything below here will not be autoprobed	1324	# everything below here will not (normally) be autoprobed
1097	# as the pureperl backend should work everywhere	1325	# as the pure perl backend should work everywhere
1098	# and is usually faster	1326	# and is usually faster
		1327	[Event:: => AnyEvent::Impl::Event::, 1],
1099	[Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers	1328	[Glib:: => AnyEvent::Impl::Glib:: , 1], # becomes extremely slow with many watchers
1100	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy	1329	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
		1330	[Irssi:: => AnyEvent::Impl::Irssi::], # Irssi has a bogus "Event" package
1101	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles	1331	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
1102	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program	1332	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program
1103	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza	1333	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
1104	[Wx:: => AnyEvent::Impl::POE::],	1334	[Wx:: => AnyEvent::Impl::POE::],
1105	[Prima:: => AnyEvent::Impl::POE::],	1335	[Prima:: => AnyEvent::Impl::POE::],
1106	# IO::Async is just too broken - we would need workarounds for its	1336	[IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # a bitch to autodetect
1107	# byzantine signal and broken child handling, among others.	1337	[Cocoa::EventLoop:: => AnyEvent::Impl::Cocoa::],
1108	# IO::Async is rather hard to detect, as it doesn't have any	1338	[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	);	1339	);
1114		1340
1115	our %method = map +($_ => 1),	1341	our @isa_hook;
		1342
		1343	sub _isa_set {
		1344	my @pkg = ("AnyEvent", (map $_->[0], grep defined, @isa_hook), $MODEL);
		1345
		1346	@{"$pkg[$_-1]::ISA"} = $pkg[$_]
		1347	for 1 .. $#pkg;
		1348
		1349	grep $_ && $_->[1], @isa_hook
		1350	and AE::_reset ();
		1351	}
		1352
		1353	# used for hooking AnyEvent::Strict and AnyEvent::Debug::Wrap into the class hierarchy
		1354	sub _isa_hook($$;$) {
		1355	my ($i, $pkg, $reset_ae) = @_;
		1356
		1357	$isa_hook[$i] = $pkg ? [$pkg, $reset_ae] : undef;
		1358
		1359	_isa_set;
		1360	}
		1361
		1362	# all autoloaded methods reserve the complete glob, not just the method slot.
		1363	# due to bugs in perls method cache implementation.
1116	qw(io timer time now now_update signal child idle condvar one_event DESTROY);	1364	our @methods = qw(io timer time now now_update signal child idle condvar);
1117		1365
1118	our @post_detect;
1119
1120	sub post_detect(&) {	1366	sub detect() {
1121	my ($cb) = @_;	1367	return $MODEL if $MODEL; # some programs keep references to detect
1122		1368
1123	if ($MODEL) {	1369	local $!; # for good measure
1124	$cb->();	1370	local $SIG{__DIE__}; # we use eval
1125		1371
1126	1	1372	# free some memory
		1373	*detect = sub () { $MODEL };
		1374	# undef &func doesn't correctly update the method cache. grmbl.
		1375	# so we delete the whole glob. grmbl.
		1376	# otoh, perl doesn't let me undef an active usb, but it lets me free
		1377	# a glob with an active sub. hrm. i hope it works, but perl is
		1378	# usually buggy in this department. sigh.
		1379	delete @{"AnyEvent::"}{@methods};
		1380	undef @methods;
		1381
		1382	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z0-9:]+)$/) {
		1383	my $model = $1;
		1384	$model = "AnyEvent::Impl::$model" unless $model =~ s/::$//;
		1385	if (eval "require $model") {
		1386	AnyEvent::log 7 => "loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.";
		1387	$MODEL = $model;
1127	} else {	1388	} else {
1128	push @post_detect, $cb;	1389	AnyEvent::log 5 => "unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@";
1129		1390	}
1130	defined wantarray
1131	? bless \$cb, "AnyEvent::Util::postdetect"
1132	: ()
1133	}	1391	}
1134	}
1135		1392
1136	sub AnyEvent::Util::postdetect::DESTROY {	1393	# check for already loaded models
1137	@post_detect = grep $_ != ${$_[0]}, @post_detect;
1138	}
1139
1140	sub detect() {
1141	unless ($MODEL) {	1394	unless ($MODEL) {
1142	local $SIG{__DIE__};	1395	for (@REGISTRY, @models) {
1143		1396	my ($package, $model) = @$_;
1144	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {	1397	if (${"$package\::VERSION"} > 0) {
1145	my $model = "AnyEvent::Impl::$1";
1146	if (eval "require $model") {	1398	if (eval "require $model") {
		1399	AnyEvent::log 7 => "autodetected model '$model', using it.";
1147	$MODEL = $model;	1400	$MODEL = $model;
1148	warn "AnyEvent: loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.\n" if $VERBOSE >= 2;	1401	last;
1149	} else {	1402	}
1150	warn "AnyEvent: unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@" if $VERBOSE;
1151	}	1403	}
1152	}	1404	}
1153		1405
1154	# check for already loaded models
1155	unless ($MODEL) {	1406	unless ($MODEL) {
		1407	# try to autoload a model
1156	for (@REGISTRY, @models) {	1408	for (@REGISTRY, @models) {
1157	my ($package, $model) = @$_;	1409	my ($package, $model, $autoload) = @$_;
		1410	if (
		1411	$autoload
		1412	and eval "require $package"
1158	if (${"$package\::VERSION"} > 0) {	1413	and ${"$package\::VERSION"} > 0
1159	if (eval "require $model") {	1414	and eval "require $model"
		1415	) {
		1416	AnyEvent::log 7 => "autoloaded model '$model', using it.";
1160	$MODEL = $model;	1417	$MODEL = $model;
1161	warn "AnyEvent: autodetected model '$model', using it.\n" if $VERBOSE >= 2;
1162	last;	1418	last;
1163	}
1164	}	1419	}
1165	}	1420	}
1166		1421
1167	unless ($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	1422	$MODEL
1182	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.\n";	1423	or die "AnyEvent: backend autodetection failed - did you properly install AnyEvent?";
1183	}
1184	}	1424	}
1185
1186	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
1187
1188	unshift @ISA, $MODEL;
1189
1190	require AnyEvent::Strict if $ENV{PERL_ANYEVENT_STRICT};
1191
1192	(shift @post_detect)->() while @post_detect;
1193	}	1425	}
1194		1426
		1427	# free memory only needed for probing
		1428	undef @models;
		1429	undef @REGISTRY;
		1430
		1431	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
		1432
		1433	# now nuke some methods that are overridden by the backend.
		1434	# SUPER usage is not allowed in these.
		1435	for (qw(time signal child idle)) {
		1436	undef &{"AnyEvent::Base::$_"}
		1437	if defined &{"$MODEL\::$_"};
		1438	}
		1439
		1440	_isa_set;
		1441
		1442	# we're officially open!
		1443
		1444	if ($ENV{PERL_ANYEVENT_STRICT}) {
		1445	require AnyEvent::Strict;
		1446	}
		1447
		1448	if ($ENV{PERL_ANYEVENT_DEBUG_WRAP}) {
		1449	require AnyEvent::Debug;
		1450	AnyEvent::Debug::wrap ($ENV{PERL_ANYEVENT_DEBUG_WRAP});
		1451	}
		1452
		1453	if (length $ENV{PERL_ANYEVENT_DEBUG_SHELL}) {
		1454	require AnyEvent::Socket;
		1455	require AnyEvent::Debug;
		1456
		1457	my $shell = $ENV{PERL_ANYEVENT_DEBUG_SHELL};
		1458	$shell =~ s/\$\$/$$/g;
		1459
		1460	my ($host, $service) = AnyEvent::Socket::parse_hostport ($shell);
		1461	$AnyEvent::Debug::SHELL = AnyEvent::Debug::shell ($host, $service);
		1462	}
		1463
		1464	# now the anyevent environment is set up as the user told us to, so
		1465	# call the actual user code - post detects
		1466
		1467	(shift @post_detect)->() while @post_detect;
		1468	undef @post_detect;
		1469
		1470	*post_detect = sub(&) {
		1471	shift->();
		1472
		1473	undef
		1474	};
		1475
1195	$MODEL	1476	$MODEL
1196	}	1477	}
1197		1478
1198	sub AUTOLOAD {	1479	for my $name (@methods) {
1199	(my $func = $AUTOLOAD) =~ s/.*://;	1480	*$name = sub {
1200		1481	detect;
1201	$method{$func}	1482	# we use goto because
1202	or Carp::croak "$func: not a valid method for AnyEvent objects";	1483	# a) it makes the thunk more transparent
1203		1484	# b) it allows us to delete the thunk later
1204	detect unless $MODEL;	1485	goto &{ UNIVERSAL::can AnyEvent => "SUPER::$name" }
1205		1486	};
1206	my $class = shift;
1207	$class->$func (@_);
1208	}	1487	}
1209		1488
1210	# utility function to dup a filehandle. this is used by many backends	1489	# utility function to dup a filehandle. this is used by many backends
1211	# to support binding more than one watcher per filehandle (they usually	1490	# 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).	1491	# 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	1501	# we assume CLOEXEC is already set by perl in all important cases
1223		1502
1224	($fh2, $rw)	1503	($fh2, $rw)
1225	}	1504	}
1226		1505
		1506	=head1 SIMPLIFIED AE API
		1507
		1508	Starting with version 5.0, AnyEvent officially supports a second, much
		1509	simpler, API that is designed to reduce the calling, typing and memory
		1510	overhead by using function call syntax and a fixed number of parameters.
		1511
		1512	See the L<AE> manpage for details.
		1513
		1514	=cut
		1515
		1516	package AE;
		1517
		1518	our $VERSION = $AnyEvent::VERSION;
		1519
		1520	sub _reset() {
		1521	eval q{
		1522	# fall back to the main API by default - backends and AnyEvent::Base
		1523	# implementations can overwrite these.
		1524
		1525	sub io($$$) {
		1526	AnyEvent->io (fh => $_[0], poll => $_[1] ? "w" : "r", cb => $_[2])
		1527	}
		1528
		1529	sub timer($$$) {
		1530	AnyEvent->timer (after => $_[0], interval => $_[1], cb => $_[2])
		1531	}
		1532
		1533	sub signal($$) {
		1534	AnyEvent->signal (signal => $_[0], cb => $_[1])
		1535	}
		1536
		1537	sub child($$) {
		1538	AnyEvent->child (pid => $_[0], cb => $_[1])
		1539	}
		1540
		1541	sub idle($) {
		1542	AnyEvent->idle (cb => $_[0]);
		1543	}
		1544
		1545	sub cv(;&) {
		1546	AnyEvent->condvar (@_ ? (cb => $_[0]) : ())
		1547	}
		1548
		1549	sub now() {
		1550	AnyEvent->now
		1551	}
		1552
		1553	sub now_update() {
		1554	AnyEvent->now_update
		1555	}
		1556
		1557	sub time() {
		1558	AnyEvent->time
		1559	}
		1560
		1561	*postpone = \&AnyEvent::postpone;
		1562	*log = \&AnyEvent::log;
		1563	};
		1564	die if $@;
		1565	}
		1566
		1567	BEGIN { _reset }
		1568
1227	package AnyEvent::Base;	1569	package AnyEvent::Base;
1228		1570
1229	# default implementations for many methods	1571	# default implementations for many methods
1230		1572
1231	sub _time {	1573	sub time {
		1574	eval q{ # poor man's autoloading {}
1232	# probe for availability of Time::HiRes	1575	# probe for availability of Time::HiRes
1233	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {	1576	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {
1234	warn "AnyEvent: using Time::HiRes for sub-second timing accuracy.\n" if $VERBOSE >= 8;	1577	*time = sub { Time::HiRes::time () };
1235	*_time = \&Time::HiRes::time;	1578	*AE::time = \& Time::HiRes::time ;
		1579	*now = \&time;
		1580	AnyEvent::log 8 => "AnyEvent: using Time::HiRes for sub-second timing accuracy.";
1236	# if (eval "use POSIX (); (POSIX::times())...	1581	# if (eval "use POSIX (); (POSIX::times())...
1237	} else {	1582	} else {
		1583	*time = sub { CORE::time };
		1584	*AE::time = sub (){ CORE::time };
		1585	*now = \&time;
1238	warn "AnyEvent: using built-in time(), WARNING, no sub-second resolution!\n" if $VERBOSE;	1586	AnyEvent::log 3 => "using built-in time(), WARNING, no sub-second resolution!";
1239	*_time = sub { time }; # epic fail	1587	}
1240	}	1588	};
		1589	die if $@;
1241		1590
1242	&_time	1591	&time
1243	}	1592	}
1244		1593
1245	sub time { _time }	1594	*now = \&time;
1246	sub now { _time }
1247	sub now_update { }	1595	sub now_update { }
1248		1596
		1597	sub _poll {
		1598	Carp::croak "$AnyEvent::MODEL does not support blocking waits. Caught";
		1599	}
		1600
1249	# default implementation for ->condvar	1601	# default implementation for ->condvar
		1602	# in fact, the default should not be overwritten
1250		1603
1251	sub condvar {	1604	sub condvar {
		1605	eval q{ # poor man's autoloading {}
		1606	*condvar = sub {
1252	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"	1607	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"
		1608	};
		1609
		1610	*AE::cv = sub (;&) {
		1611	bless { @_ ? (_ae_cb => shift) : () }, "AnyEvent::CondVar"
		1612	};
		1613	};
		1614	die if $@;
		1615
		1616	&condvar
1253	}	1617	}
1254		1618
1255	# default implementation for ->signal	1619	# default implementation for ->signal
1256		1620
1257	our $HAVE_ASYNC_INTERRUPT;	1621	our $HAVE_ASYNC_INTERRUPT;
		1622
		1623	sub _have_async_interrupt() {
		1624	$HAVE_ASYNC_INTERRUPT = 1*(!$ENV{PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT}
		1625	&& eval "use Async::Interrupt 1.02 (); 1")
		1626	unless defined $HAVE_ASYNC_INTERRUPT;
		1627
		1628	$HAVE_ASYNC_INTERRUPT
		1629	}
		1630
1258	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);	1631	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);
1259	our (%SIG_ASY, %SIG_ASY_W);	1632	our (%SIG_ASY, %SIG_ASY_W);
1260	our ($SIG_COUNT, $SIG_TW);	1633	our ($SIG_COUNT, $SIG_TW);
1261		1634
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	1635	# install a dummy wakeup watcher to reduce signal catching latency
		1636	# used by Impls
1276	sub _sig_add() {	1637	sub _sig_add() {
1277	unless ($SIG_COUNT++) {	1638	unless ($SIG_COUNT++) {
1278	# try to align timer on a full-second boundary, if possible	1639	# try to align timer on a full-second boundary, if possible
1279	my $NOW = AnyEvent->now;	1640	my $NOW = AE::now;
1280		1641
1281	$SIG_TW = AnyEvent->timer (	1642	$SIG_TW = AE::timer
1282	after => $MAX_SIGNAL_LATENCY - ($NOW - int $NOW),	1643	$MAX_SIGNAL_LATENCY - ($NOW - int $NOW),
1283	interval => $MAX_SIGNAL_LATENCY,	1644	$MAX_SIGNAL_LATENCY,
1284	cb => sub { }, # just for the PERL_ASYNC_CHECK	1645	sub { } # just for the PERL_ASYNC_CHECK
1285	);	1646	;
1286	}	1647	}
1287	}	1648	}
1288		1649
1289	sub _sig_del {	1650	sub _sig_del {
1290	undef $SIG_TW	1651	undef $SIG_TW
1291	unless --$SIG_COUNT;	1652	unless --$SIG_COUNT;
1292	}	1653	}
1293		1654
		1655	our $_sig_name_init; $_sig_name_init = sub {
		1656	eval q{ # poor man's autoloading {}
		1657	undef $_sig_name_init;
		1658
		1659	if (_have_async_interrupt) {
		1660	*sig2num = \&Async::Interrupt::sig2num;
		1661	*sig2name = \&Async::Interrupt::sig2name;
		1662	} else {
		1663	require Config;
		1664
		1665	my %signame2num;
		1666	@signame2num{ split ' ', $Config::Config{sig_name} }
		1667	= split ' ', $Config::Config{sig_num};
		1668
		1669	my @signum2name;
		1670	@signum2name[values %signame2num] = keys %signame2num;
		1671
		1672	*sig2num = sub($) {
		1673	$_[0] > 0 ? shift : $signame2num{+shift}
		1674	};
		1675	*sig2name = sub ($) {
		1676	$_[0] > 0 ? $signum2name[+shift] : shift
		1677	};
		1678	}
		1679	};
		1680	die if $@;
		1681	};
		1682
		1683	sub sig2num ($) { &$_sig_name_init; &sig2num }
		1684	sub sig2name($) { &$_sig_name_init; &sig2name }
		1685
1294	sub _signal {	1686	sub signal {
1295	my (undef, %arg) = @_;	1687	eval q{ # poor man's autoloading {}
		1688	# probe for availability of Async::Interrupt
		1689	if (_have_async_interrupt) {
		1690	AnyEvent::log 8 => "using Async::Interrupt for race-free signal handling.";
1296		1691
1297	my $signal = uc $arg{signal}	1692	$SIGPIPE_R = new Async::Interrupt::EventPipe;
1298	or Carp::croak "required option 'signal' is missing";	1693	$SIG_IO = AE::io $SIGPIPE_R->fileno, 0, \&_signal_exec;
1299		1694
1300	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};	1695	} else {
		1696	AnyEvent::log 8 => "using emulated perl signal handling with latency timer.";
1301		1697
1302	if ($HAVE_ASYNC_INTERRUPT) {	1698	if (AnyEvent::WIN32) {
1303	# async::interrupt	1699	require AnyEvent::Util;
1304		1700
1305	$SIG_ASY{$signal} ||= do {	1701	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
1306	my $asy = new Async::Interrupt	1702	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R, 1) if $SIGPIPE_R;
1307	cb => sub { undef $SIG_EV{$signal} },	1703	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W, 1) if $SIGPIPE_W; # just in case
1308	signal => $signal,	1704	} else {
1309	pipe => [$SIGPIPE_R->filenos],	1705	pipe $SIGPIPE_R, $SIGPIPE_W;
		1706	fcntl $SIGPIPE_R, AnyEvent::F_SETFL, AnyEvent::O_NONBLOCK if $SIGPIPE_R;
		1707	fcntl $SIGPIPE_W, AnyEvent::F_SETFL, AnyEvent::O_NONBLOCK if $SIGPIPE_W; # just in case
		1708
		1709	# not strictly required, as $^F is normally 2, but let's make sure...
		1710	fcntl $SIGPIPE_R, AnyEvent::F_SETFD, AnyEvent::FD_CLOEXEC;
		1711	fcntl $SIGPIPE_W, AnyEvent::F_SETFD, AnyEvent::FD_CLOEXEC;
1310	;	1712	}
1311	$asy->pipe_autodrain (0);
1312		1713
1313	$asy	1714	$SIGPIPE_R
		1715	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";
		1716
		1717	$SIG_IO = AE::io $SIGPIPE_R, 0, \&_signal_exec;
		1718	}
		1719
		1720	*signal = $HAVE_ASYNC_INTERRUPT
		1721	? sub {
		1722	my (undef, %arg) = @_;
		1723
		1724	# async::interrupt
		1725	my $signal = sig2num $arg{signal};
		1726	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
		1727
		1728	$SIG_ASY{$signal} ||= new Async::Interrupt
		1729	cb => sub { undef $SIG_EV{$signal} },
		1730	signal => $signal,
		1731	pipe => [$SIGPIPE_R->filenos],
		1732	pipe_autodrain => 0,
		1733	;
		1734
		1735	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
		1736	}
		1737	: sub {
		1738	my (undef, %arg) = @_;
		1739
		1740	# pure perl
		1741	my $signal = sig2name $arg{signal};
		1742	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
		1743
		1744	$SIG{$signal} ||= sub {
		1745	local $!;
		1746	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;
		1747	undef $SIG_EV{$signal};
		1748	};
		1749
		1750	# can't do signal processing without introducing races in pure perl,
		1751	# so limit the signal latency.
		1752	_sig_add;
		1753
		1754	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
		1755	}
		1756	;
		1757
		1758	*AnyEvent::Base::signal::DESTROY = sub {
		1759	my ($signal, $cb) = @{$_[0]};
		1760
		1761	_sig_del;
		1762
		1763	delete $SIG_CB{$signal}{$cb};
		1764
		1765	$HAVE_ASYNC_INTERRUPT
		1766	? delete $SIG_ASY{$signal}
		1767	: # delete doesn't work with older perls - they then
		1768	# print weird messages, or just unconditionally exit
		1769	# instead of getting the default action.
		1770	undef $SIG{$signal}
		1771	unless keys %{ $SIG_CB{$signal} };
1314	};	1772	};
1315		1773
1316	} else {	1774	*_signal_exec = sub {
1317	# pure perl	1775	$HAVE_ASYNC_INTERRUPT
		1776	? $SIGPIPE_R->drain
		1777	: sysread $SIGPIPE_R, (my $dummy), 9;
1318		1778
1319	$SIG{$signal} ||= sub {	1779	while (%SIG_EV) {
1320	local $!;	1780	for (keys %SIG_EV) {
1321	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;	1781	delete $SIG_EV{$_};
1322	undef $SIG_EV{$signal};	1782	&$_ for values %{ $SIG_CB{$_} || {} };
		1783	}
		1784	}
1323	};	1785	};
1324
1325	# can't do signal processing without introducing races in pure perl,
1326	# so limit the signal latency.
1327	_sig_add;
1328	}	1786	};
		1787	die if $@;
1329		1788
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	1789	&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	}	1790	}
1388		1791
1389	# default implementation for ->child	1792	# default implementation for ->child
1390		1793
1391	our %PID_CB;	1794	our %PID_CB;
1392	our $CHLD_W;	1795	our $CHLD_W;
1393	our $CHLD_DELAY_W;	1796	our $CHLD_DELAY_W;
1394	our $WNOHANG;
1395		1797
1396	sub _sigchld {	1798	# used by many Impl's
1397	while (0 < (my $pid = waitpid -1, $WNOHANG)) {	1799	sub _emit_childstatus($$) {
1398	$_->($pid, $?)	1800	my (undef, $rpid, $rstatus) = @_;
		1801
		1802	$_->($rpid, $rstatus)
1399	for values %{ $PID_CB{$pid} || {} },	1803	for values %{ $PID_CB{$rpid} || {} },
1400	values %{ $PID_CB{0} || {} };	1804	values %{ $PID_CB{0} || {} };
1401	}
1402	}	1805	}
1403		1806
1404	sub child {	1807	sub child {
		1808	eval q{ # poor man's autoloading {}
		1809	*_sigchld = sub {
		1810	my $pid;
		1811
		1812	AnyEvent->_emit_childstatus ($pid, $?)
		1813	while ($pid = waitpid -1, WNOHANG) > 0;
		1814	};
		1815
		1816	*child = sub {
1405	my (undef, %arg) = @_;	1817	my (undef, %arg) = @_;
1406		1818
1407	defined (my $pid = $arg{pid} + 0)	1819	my $pid = $arg{pid};
1408	or Carp::croak "required option 'pid' is missing";	1820	my $cb = $arg{cb};
1409		1821
1410	$PID_CB{$pid}{$arg{cb}} = $arg{cb};	1822	$PID_CB{$pid}{$cb+0} = $cb;
1411		1823
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) {	1824	unless ($CHLD_W) {
1418	$CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld);	1825	$CHLD_W = AE::signal CHLD => \&_sigchld;
1419	# child could be a zombie already, so make at least one round	1826	# child could be a zombie already, so make at least one round
1420	&_sigchld;	1827	&_sigchld;
1421	}	1828	}
1422		1829
1423	bless [$pid, $arg{cb}], "AnyEvent::Base::child"	1830	bless [$pid, $cb+0], "AnyEvent::Base::child"
1424	}	1831	};
1425		1832
1426	sub AnyEvent::Base::child::DESTROY {	1833	*AnyEvent::Base::child::DESTROY = sub {
1427	my ($pid, $cb) = @{$_[0]};	1834	my ($pid, $icb) = @{$_[0]};
1428		1835
1429	delete $PID_CB{$pid}{$cb};	1836	delete $PID_CB{$pid}{$icb};
1430	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };	1837	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };
1431		1838
1432	undef $CHLD_W unless keys %PID_CB;	1839	undef $CHLD_W unless keys %PID_CB;
		1840	};
		1841	};
		1842	die if $@;
		1843
		1844	&child
1433	}	1845	}
1434		1846
1435	# idle emulation is done by simply using a timer, regardless	1847	# idle emulation is done by simply using a timer, regardless
1436	# of whether the process is idle or not, and not letting	1848	# of whether the process is idle or not, and not letting
1437	# the callback use more than 50% of the time.	1849	# the callback use more than 50% of the time.
1438	sub idle {	1850	sub idle {
		1851	eval q{ # poor man's autoloading {}
		1852	*idle = sub {
1439	my (undef, %arg) = @_;	1853	my (undef, %arg) = @_;
1440		1854
1441	my ($cb, $w, $rcb) = $arg{cb};	1855	my ($cb, $w, $rcb) = $arg{cb};
1442		1856
1443	$rcb = sub {	1857	$rcb = sub {
1444	if ($cb) {	1858	if ($cb) {
1445	$w = _time;	1859	$w = AE::time;
1446	&$cb;	1860	&$cb;
1447	$w = _time - $w;	1861	$w = AE::time - $w;
1448		1862
1449	# never use more then 50% of the time for the idle watcher,	1863	# never use more then 50% of the time for the idle watcher,
1450	# within some limits	1864	# within some limits
1451	$w = 0.0001 if $w < 0.0001;	1865	$w = 0.0001 if $w < 0.0001;
1452	$w = 5 if $w > 5;	1866	$w = 5 if $w > 5;
1453		1867
1454	$w = AnyEvent->timer (after => $w, cb => $rcb);	1868	$w = AE::timer $w, 0, $rcb;
1455	} else {	1869	} else {
1456	# clean up...	1870	# clean up...
1457	undef $w;	1871	undef $w;
1458	undef $rcb;	1872	undef $rcb;
		1873	}
		1874	};
		1875
		1876	$w = AE::timer 0.05, 0, $rcb;
		1877
		1878	bless \\$cb, "AnyEvent::Base::idle"
1459	}	1879	};
		1880
		1881	*AnyEvent::Base::idle::DESTROY = sub {
		1882	undef $${$_[0]};
		1883	};
1460	};	1884	};
		1885	die if $@;
1461		1886
1462	$w = AnyEvent->timer (after => 0.05, cb => $rcb);	1887	&idle
1463
1464	bless \\$cb, "AnyEvent::Base::idle"
1465	}
1466
1467	sub AnyEvent::Base::idle::DESTROY {
1468	undef $${$_[0]};
1469	}	1888	}
1470		1889
1471	package AnyEvent::CondVar;	1890	package AnyEvent::CondVar;
1472		1891
1473	our @ISA = AnyEvent::CondVar::Base::;	1892	our @ISA = AnyEvent::CondVar::Base::;
		1893
		1894	# only to be used for subclassing
		1895	sub new {
		1896	my $class = shift;
		1897	bless AnyEvent->condvar (@_), $class
		1898	}
1474		1899
1475	package AnyEvent::CondVar::Base;	1900	package AnyEvent::CondVar::Base;
1476		1901
1477	#use overload	1902	#use overload
1478	# '&{}' => sub { my $self = shift; sub { $self->send (@_) } },	1903	# '&{}' => sub { my $self = shift; sub { $self->send (@_) } },
…		…
1488		1913
1489	sub _send {	1914	sub _send {
1490	# nop	1915	# nop
1491	}	1916	}
1492		1917
		1918	sub _wait {
		1919	AnyEvent->_poll until $_[0]{_ae_sent};
		1920	}
		1921
1493	sub send {	1922	sub send {
1494	my $cv = shift;	1923	my $cv = shift;
1495	$cv->{_ae_sent} = [@_];	1924	$cv->{_ae_sent} = [@_];
1496	(delete $cv->{_ae_cb})->($cv) if $cv->{_ae_cb};	1925	(delete $cv->{_ae_cb})->($cv) if $cv->{_ae_cb};
1497	$cv->_send;	1926	$cv->_send;
…		…
1504		1933
1505	sub ready {	1934	sub ready {
1506	$_[0]{_ae_sent}	1935	$_[0]{_ae_sent}
1507	}	1936	}
1508		1937
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 {	1938	sub recv {
		1939	unless ($_[0]{_ae_sent}) {
		1940	$WAITING
		1941	and Carp::croak "AnyEvent::CondVar: recursive blocking wait attempted";
		1942
		1943	local $WAITING = 1;
1519	$_[0]->_wait;	1944	$_[0]->_wait;
		1945	}
1520		1946
1521	Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak};	1947	$_[0]{_ae_croak}
1522	wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0]	1948	and Carp::croak $_[0]{_ae_croak};
		1949
		1950	wantarray
		1951	? @{ $_[0]{_ae_sent} }
		1952	: $_[0]{_ae_sent}[0]
1523	}	1953	}
1524		1954
1525	sub cb {	1955	sub cb {
1526	$_[0]{_ae_cb} = $_[1] if @_ > 1;	1956	my $cv = shift;
		1957
		1958	@_
		1959	and $cv->{_ae_cb} = shift
		1960	and $cv->{_ae_sent}
		1961	and (delete $cv->{_ae_cb})->($cv);
		1962
1527	$_[0]{_ae_cb}	1963	$cv->{_ae_cb}
1528	}	1964	}
1529		1965
1530	sub begin {	1966	sub begin {
1531	++$_[0]{_ae_counter};	1967	++$_[0]{_ae_counter};
1532	$_[0]{_ae_end_cb} = $_[1] if @_ > 1;	1968	$_[0]{_ae_end_cb} = $_[1] if @_ > 1;
…		…
1537	&{ $_[0]{_ae_end_cb} || sub { $_[0]->send } };	1973	&{ $_[0]{_ae_end_cb} || sub { $_[0]->send } };
1538	}	1974	}
1539		1975
1540	# undocumented/compatibility with pre-3.4	1976	# undocumented/compatibility with pre-3.4
1541	*broadcast = \&send;	1977	*broadcast = \&send;
1542	*wait = \&_wait;	1978	*wait = \&recv;
1543		1979
1544	=head1 ERROR AND EXCEPTION HANDLING	1980	=head1 ERROR AND EXCEPTION HANDLING
1545		1981
1546	In general, AnyEvent does not do any error handling - it relies on the	1982	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	1983	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	1995	$Event/EV::DIED->() >>, L<Glib> uses C<< install_exception_handler >> and
1560	so on.	1996	so on.
1561		1997
1562	=head1 ENVIRONMENT VARIABLES	1998	=head1 ENVIRONMENT VARIABLES
1563		1999
1564	The following environment variables are used by this module or its	2000	AnyEvent supports a number of environment variables that tune the
1565	submodules.	2001	runtime behaviour. They are usually evaluated when AnyEvent is
		2002	loaded, initialised, or a submodule that uses them is loaded. Many of
		2003	them also cause AnyEvent to load additional modules - for example,
		2004	C<PERL_ANYEVENT_DEBUG_WRAP> causes the L<AnyEvent::Debug> module to be
		2005	loaded.
1566		2006
1567	Note that AnyEvent will remove I<all> environment variables starting with	2007	All the environment variables documented here start with
1568	C<PERL_ANYEVENT_> from C<%ENV> when it is loaded while taint mode is	2008	C<PERL_ANYEVENT_>, which is what AnyEvent considers its own
1569	enabled.	2009	namespace. Other modules are encouraged (but by no means required) to use
		2010	C<PERL_ANYEVENT_SUBMODULE> if they have registered the AnyEvent::Submodule
		2011	namespace on CPAN, for any submodule. For example, L<AnyEvent::HTTP> could
		2012	be expected to use C<PERL_ANYEVENT_HTTP_PROXY> (it should not access env
		2013	variables starting with C<AE_>, see below).
		2014
		2015	All variables can also be set via the C<AE_> prefix, that is, instead
		2016	of setting C<PERL_ANYEVENT_VERBOSE> you can also set C<AE_VERBOSE>. In
		2017	case there is a clash btween anyevent and another program that uses
		2018	C<AE_something> you can set the corresponding C<PERL_ANYEVENT_something>
		2019	variable to the empty string, as those variables take precedence.
		2020
		2021	When AnyEvent is first loaded, it copies all C<AE_xxx> env variables
		2022	to their C<PERL_ANYEVENT_xxx> counterpart unless that variable already
		2023	exists. If taint mode is on, then AnyEvent will remove I<all> environment
		2024	variables starting with C<PERL_ANYEVENT_> from C<%ENV> (or replace them
		2025	with C<undef> or the empty string, if the corresaponding C<AE_> variable
		2026	is set).
		2027
		2028	The exact algorithm is currently:
		2029
		2030	1. if taint mode enabled, delete all PERL_ANYEVENT_xyz variables from %ENV
		2031	2. copy over AE_xyz to PERL_ANYEVENT_xyz unless the latter alraedy exists
		2032	3. if taint mode enabled, set all PERL_ANYEVENT_xyz variables to undef.
		2033
		2034	This ensures that child processes will not see the C<AE_> variables.
		2035
		2036	The following environment variables are currently known to AnyEvent:
1570		2037
1571	=over 4	2038	=over 4
1572		2039
1573	=item C<PERL_ANYEVENT_VERBOSE>	2040	=item C<PERL_ANYEVENT_VERBOSE>
1574		2041
1575	By default, AnyEvent will be completely silent except in fatal	2042	By default, AnyEvent will only log messages with loglevel C<3>
1576	conditions. You can set this environment variable to make AnyEvent more	2043	(C<critical>) or higher (see L<AnyEvent::Log>). You can set this
		2044	environment variable to a numerical loglevel to make AnyEvent more (or
1577	talkative.	2045	less) talkative.
1578		2046
		2047	If you want to do more than just set the global logging level
		2048	you should have a look at C<PERL_ANYEVENT_LOG>, which allows much more
		2049	complex specifications.
		2050
		2051	When set to C<0> (C<off>), then no messages whatsoever will be logged with
		2052	the default logging settings.
		2053
1579	When set to C<1> or higher, causes AnyEvent to warn about unexpected	2054	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	2055	unexpected conditions, such as not being able to load the event model
1581	C<PERL_ANYEVENT_MODEL>.	2056	specified by C<PERL_ANYEVENT_MODEL>, or a guard callback throwing an
		2057	exception - this is the minimum recommended level.
1582		2058
1583	When set to C<2> or higher, cause AnyEvent to report to STDERR which event	2059	When set to C<7> or higher (info), cause AnyEvent to report which event model it
1584	model it chooses.	2060	chooses.
1585		2061
1586	When set to C<8> or higher, then AnyEvent will report extra information on	2062	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.	2063	which optional modules it loads and how it implements certain features.
		2064
		2065	=item C<PERL_ANYEVENT_LOG>
		2066
		2067	Accepts rather complex logging specifications. For example, you could log
		2068	all C<debug> messages of some module to stderr, warnings and above to
		2069	stderr, and errors and above to syslog, with:
		2070
		2071	PERL_ANYEVENT_LOG=Some::Module=debug,+log:filter=warn,+%syslog:%syslog=error,syslog
		2072
		2073	For the rather extensive details, see L<AnyEvent::Log>.
		2074
		2075	This variable is evaluated when AnyEvent (or L<AnyEvent::Log>) is loaded,
		2076	so will take effect even before AnyEvent has initialised itself.
		2077
		2078	Note that specifying this environment variable causes the L<AnyEvent::Log>
		2079	module to be loaded, while C<PERL_ANYEVENT_VERBOSE> does not, so only
		2080	using the latter saves a few hundred kB of memory until the first message
		2081	is being logged.
1588		2082
1589	=item C<PERL_ANYEVENT_STRICT>	2083	=item C<PERL_ANYEVENT_STRICT>
1590		2084
1591	AnyEvent does not do much argument checking by default, as thorough	2085	AnyEvent does not do much argument checking by default, as thorough
1592	argument checking is very costly. Setting this variable to a true value	2086	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,	2088	check the arguments passed to most method calls. If it finds any problems,
1595	it will croak.	2089	it will croak.
1596		2090
1597	In other words, enables "strict" mode.	2091	In other words, enables "strict" mode.
1598		2092
1599	Unlike C<use strict> (or it's modern cousin, C<< use L<common::sense>	2093	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	2094	>>, it is definitely recommended to keep it off in production. Keeping
1601	C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs	2095	C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs
1602	can be very useful, however.	2096	can be very useful, however.
1603		2097
		2098	=item C<PERL_ANYEVENT_DEBUG_SHELL>
		2099
		2100	If this env variable is nonempty, then its contents will be interpreted by
		2101	C<AnyEvent::Socket::parse_hostport> and C<AnyEvent::Debug::shell> (after
		2102	replacing every occurance of C<$$> by the process pid). The shell object
		2103	is saved in C<$AnyEvent::Debug::SHELL>.
		2104
		2105	This happens when the first watcher is created.
		2106
		2107	For example, to bind a debug shell on a unix domain socket in
		2108	F<< /tmp/debug<pid>.sock >>, you could use this:
		2109
		2110	PERL_ANYEVENT_DEBUG_SHELL=/tmp/debug\$\$.sock perlprog
		2111	# connect with e.g.: socat readline /tmp/debug123.sock
		2112
		2113	Or to bind to tcp port 4545 on localhost:
		2114
		2115	PERL_ANYEVENT_DEBUG_SHELL=127.0.0.1:4545 perlprog
		2116	# connect with e.g.: telnet localhost 4545
		2117
		2118	Note that creating sockets in F</tmp> or on localhost is very unsafe on
		2119	multiuser systems.
		2120
		2121	=item C<PERL_ANYEVENT_DEBUG_WRAP>
		2122
		2123	Can be set to C<0>, C<1> or C<2> and enables wrapping of all watchers for
		2124	debugging purposes. See C<AnyEvent::Debug::wrap> for details.
		2125
1604	=item C<PERL_ANYEVENT_MODEL>	2126	=item C<PERL_ANYEVENT_MODEL>
1605		2127
1606	This can be used to specify the event model to be used by AnyEvent, before	2128	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	2129	auto detection and -probing kicks in.
1608	entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended	2130
		2131	It normally is a string consisting entirely of ASCII letters (e.g. C<EV>
		2132	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,	2133	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	2134	event model backend. If it fails to load then AnyEvent will proceed with
1611	auto detection and -probing.	2135	auto detection and -probing.
1612		2136
1613	This functionality might change in future versions.	2137	If the string ends with C<::> instead (e.g. C<AnyEvent::Impl::EV::>) then
		2138	nothing gets prepended and the module name is used as-is (hint: C<::> at
		2139	the end of a string designates a module name and quotes it appropriately).
1614		2140
1615	For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you	2141	For example, to force the pure perl model (L<AnyEvent::Loop::Perl>) you
1616	could start your program like this:	2142	could start your program like this:
1617		2143
1618	PERL_ANYEVENT_MODEL=Perl perl ...	2144	PERL_ANYEVENT_MODEL=Perl perl ...
1619		2145
1620	=item C<PERL_ANYEVENT_PROTOCOLS>	2146	=item C<PERL_ANYEVENT_PROTOCOLS>
…		…
1636	but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4>	2162	but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4>
1637	- only support IPv4, never try to resolve or contact IPv6	2163	- only support IPv4, never try to resolve or contact IPv6
1638	addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or	2164	addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or
1639	IPv6, but prefer IPv6 over IPv4.	2165	IPv6, but prefer IPv6 over IPv4.
1640		2166
		2167	=item C<PERL_ANYEVENT_HOSTS>
		2168
		2169	This variable, if specified, overrides the F</etc/hosts> file used by
		2170	L<AnyEvent::Socket>C<::resolve_sockaddr>, i.e. hosts aliases will be read
		2171	from that file instead.
		2172
1641	=item C<PERL_ANYEVENT_EDNS0>	2173	=item C<PERL_ANYEVENT_EDNS0>
1642		2174
1643	Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension	2175	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	2176	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	2177	when DNSSEC is involved, but some (broken) firewalls drop such DNS
1646	default.	2178	packets, which is why it is off by default.
1647		2179
1648	Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce	2180	Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce
1649	EDNS0 in its DNS requests.	2181	EDNS0 in its DNS requests.
1650		2182
1651	=item C<PERL_ANYEVENT_MAX_FORKS>	2183	=item C<PERL_ANYEVENT_MAX_FORKS>
…		…
1659	resolver - this is the maximum number of parallel DNS requests that are	2191	resolver - this is the maximum number of parallel DNS requests that are
1660	sent to the DNS server.	2192	sent to the DNS server.
1661		2193
1662	=item C<PERL_ANYEVENT_RESOLV_CONF>	2194	=item C<PERL_ANYEVENT_RESOLV_CONF>
1663		2195
1664	The file to use instead of F</etc/resolv.conf> (or OS-specific	2196	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	2197	F</etc/resolv.conf> (or the OS-specific configuration) in the default
1666	default config will be used.	2198	resolver, or the empty string to select the default configuration.
1667		2199
1668	=item C<PERL_ANYEVENT_CA_FILE>, C<PERL_ANYEVENT_CA_PATH>.	2200	=item C<PERL_ANYEVENT_CA_FILE>, C<PERL_ANYEVENT_CA_PATH>.
1669		2201
1670	When neither C<ca_file> nor C<ca_path> was specified during	2202	When neither C<ca_file> nor C<ca_path> was specified during
1671	L<AnyEvent::TLS> context creation, and either of these environment	2203	L<AnyEvent::TLS> context creation, and either of these environment
1672	variables exist, they will be used to specify CA certificate locations	2204	variables are nonempty, they will be used to specify CA certificate
1673	instead of a system-dependent default.	2205	locations instead of a system-dependent default.
1674		2206
1675	=item C<PERL_ANYEVENT_AVOID_GUARD> and C<PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT>	2207	=item C<PERL_ANYEVENT_AVOID_GUARD> and C<PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT>
1676		2208
1677	When these are set to C<1>, then the respective modules are not	2209	When these are set to C<1>, then the respective modules are not
1678	loaded. Mostly good for testing AnyEvent itself.	2210	loaded. Mostly good for testing AnyEvent itself.
…		…
1741	warn "read: $input\n"; # output what has been read	2273	warn "read: $input\n"; # output what has been read
1742	$cv->send if $input =~ /^q/i; # quit program if /^q/i	2274	$cv->send if $input =~ /^q/i; # quit program if /^q/i
1743	},	2275	},
1744	);	2276	);
1745		2277
1746	my $time_watcher; # can only be used once
1747
1748	sub new_timer {
1749	$timer = AnyEvent->timer (after => 1, cb => sub {	2278	my $time_watcher = AnyEvent->timer (after => 1, interval => 1, cb => sub {
1750	warn "timeout\n"; # print 'timeout' about every second	2279	warn "timeout\n"; # print 'timeout' at most every second
1751	&new_timer; # and restart the time
1752	});	2280	});
1753	}
1754
1755	new_timer; # create first timer
1756		2281
1757	$cv->recv; # wait until user enters /^q/i	2282	$cv->recv; # wait until user enters /^q/i
1758		2283
1759	=head1 REAL-WORLD EXAMPLE	2284	=head1 REAL-WORLD EXAMPLE
1760		2285
…		…
1833		2358
1834	The actual code goes further and collects all errors (C<die>s, exceptions)	2359	The actual code goes further and collects all errors (C<die>s, exceptions)
1835	that occurred during request processing. The C<result> method detects	2360	that occurred during request processing. The C<result> method detects
1836	whether an exception as thrown (it is stored inside the $txn object)	2361	whether an exception as thrown (it is stored inside the $txn object)
1837	and just throws the exception, which means connection errors and other	2362	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	2363	problems get reported to the code that tries to use the result, not in a
1839	random callback.	2364	random callback.
1840		2365
1841	All of this enables the following usage styles:	2366	All of this enables the following usage styles:
1842		2367
1843	1. Blocking:	2368	1. Blocking:
…		…
1891	through AnyEvent. The benchmark creates a lot of timers (with a zero	2416	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,	2417	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.	2418	which it is), lets them fire exactly once and destroys them again.
1894		2419
1895	Source code for this benchmark is found as F<eg/bench> in the AnyEvent	2420	Source code for this benchmark is found as F<eg/bench> in the AnyEvent
1896	distribution.	2421	distribution. It uses the L<AE> interface, which makes a real difference
		2422	for the EV and Perl backends only.
1897		2423
1898	=head3 Explanation of the columns	2424	=head3 Explanation of the columns
1899		2425
1900	I<watcher> is the number of event watchers created/destroyed. Since	2426	I<watcher> is the number of event watchers created/destroyed. Since
1901	different event models feature vastly different performances, each event	2427	different event models feature vastly different performances, each event
…		…
1922	watcher.	2448	watcher.
1923		2449
1924	=head3 Results	2450	=head3 Results
1925		2451
1926	name watchers bytes create invoke destroy comment	2452	name watchers bytes create invoke destroy comment
1927	EV/EV 400000 224 0.47 0.35 0.27 EV native interface	2453	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	2454	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	2455	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	2456	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	2457	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	2458	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	2459	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	2460	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	2461	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	2462	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	2463	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	2464	POE/Any 2000 6648 94.79 774.40 575.51 via POE::Loop::Select
1939		2465
1940	=head3 Discussion	2466	=head3 Discussion
1941		2467
1942	The benchmark does I<not> measure scalability of the event loop very	2468	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)	2469	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	2481	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	2482	EV, 3100 CPU cycles with AnyEvent's pure perl loop and almost 3000000 CPU
1957	cycles with POE.	2483	cycles with POE.
1958		2484
1959	C<EV> is the sole leader regarding speed and memory use, which are both	2485	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	2486	maximal/minimal, respectively. When using the L<AE> API there is zero
		2487	overhead (when going through the AnyEvent API create is about 5-6 times
		2488	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	2489	any other event loop and is still faster than Event natively).
1962	natively.
1963		2490
1964	The pure perl implementation is hit in a few sweet spots (both the	2491	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	2492	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	2493	interpreter and the backend itself). Nevertheless this shows that it
1967	adds very little overhead in itself. Like any select-based backend its	2494	adds very little overhead in itself. Like any select-based backend its
…		…
2015	(even when used without AnyEvent), but most event loops have acceptable	2542	(even when used without AnyEvent), but most event loops have acceptable
2016	performance with or without AnyEvent.	2543	performance with or without AnyEvent.
2017		2544
2018	=item * The overhead AnyEvent adds is usually much smaller than the overhead of	2545	=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	2546	the actual event loop, only with extremely fast event loops such as EV
2020	adds AnyEvent significant overhead.	2547	does AnyEvent add significant overhead.
2021		2548
2022	=item * You should avoid POE like the plague if you want performance or	2549	=item * You should avoid POE like the plague if you want performance or
2023	reasonable memory usage.	2550	reasonable memory usage.
2024		2551
2025	=back	2552	=back
…		…
2041	In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100	2568	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	2569	(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.	2570	connections, most of which are idle at any one point in time.
2044		2571
2045	Source code for this benchmark is found as F<eg/bench2> in the AnyEvent	2572	Source code for this benchmark is found as F<eg/bench2> in the AnyEvent
2046	distribution.	2573	distribution. It uses the L<AE> interface, which makes a real difference
		2574	for the EV and Perl backends only.
2047		2575
2048	=head3 Explanation of the columns	2576	=head3 Explanation of the columns
2049		2577
2050	I<sockets> is the number of sockets, and twice the number of "servers" (as	2578	I<sockets> is the number of sockets, and twice the number of "servers" (as
2051	each server has a read and write socket end).	2579	each server has a read and write socket end).
…		…
2059	a new one that moves the timeout into the future.	2587	a new one that moves the timeout into the future.
2060		2588
2061	=head3 Results	2589	=head3 Results
2062		2590
2063	name sockets create request	2591	name sockets create request
2064	EV 20000 69.01 11.16	2592	EV 20000 62.66 7.99
2065	Perl 20000 73.32 35.87	2593	Perl 20000 68.32 32.64
2066	IOAsync 20000 157.00 98.14 epoll	2594	IOAsync 20000 174.06 101.15 epoll
2067	IOAsync 20000 159.31 616.06 poll	2595	IOAsync 20000 174.67 610.84 poll
2068	Event 20000 212.62 257.32	2596	Event 20000 202.69 242.91
2069	Glib 20000 651.16 1896.30	2597	Glib 20000 557.01 1689.52
2070	POE 20000 349.67 12317.24 uses POE::Loop::Event	2598	POE 20000 341.54 12086.32 uses POE::Loop::Event
2071		2599
2072	=head3 Discussion	2600	=head3 Discussion
2073		2601
2074	This benchmark I<does> measure scalability and overall performance of the	2602	This benchmark I<does> measure scalability and overall performance of the
2075	particular event loop.	2603	particular event loop.
…		…
2201	As you can see, the AnyEvent + EV combination even beats the	2729	As you can see, the AnyEvent + EV combination even beats the
2202	hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl	2730	hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl
2203	backend easily beats IO::Lambda and POE.	2731	backend easily beats IO::Lambda and POE.
2204		2732
2205	And even the 100% non-blocking version written using the high-level (and	2733	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	2734	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	2735	higher level ("unoptimised") abstractions by a large margin, even though
2208	in a non-blocking way.	2736	it does all of DNS, tcp-connect and socket I/O in a non-blocking way.
2209		2737
2210	The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and	2738	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	2739	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.	2740	part of the IO::Lambda distribution and were used without any changes.
2213		2741
2214		2742
2215	=head1 SIGNALS	2743	=head1 SIGNALS
2216		2744
2217	AnyEvent currently installs handlers for these signals:	2745	AnyEvent currently installs handlers for these signals:
…		…
2254	unless defined $SIG{PIPE};	2782	unless defined $SIG{PIPE};
2255		2783
2256	=head1 RECOMMENDED/OPTIONAL MODULES	2784	=head1 RECOMMENDED/OPTIONAL MODULES
2257		2785
2258	One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and	2786	One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and
2259	it's built-in modules) are required to use it.	2787	its built-in modules) are required to use it.
2260		2788
2261	That does not mean that AnyEvent won't take advantage of some additional	2789	That does not mean that AnyEvent won't take advantage of some additional
2262	modules if they are installed.	2790	modules if they are installed.
2263		2791
2264	This section epxlains which additional modules will be used, and how they	2792	This section explains which additional modules will be used, and how they
2265	affect AnyEvent's operetion.	2793	affect AnyEvent's operation.
2266		2794
2267	=over 4	2795	=over 4
2268		2796
2269	=item L<Async::Interrupt>	2797	=item L<Async::Interrupt>
2270		2798
2271	This slightly arcane module is used to implement fast signal handling: To	2799	This slightly arcane module is used to implement fast signal handling: To
2272	my knowledge, there is no way to do completely race-free and quick	2800	my knowledge, there is no way to do completely race-free and quick
2273	signal handling in pure perl. To ensure that signals still get	2801	signal handling in pure perl. To ensure that signals still get
2274	delivered, AnyEvent will start an interval timer to wake up perl (and	2802	delivered, AnyEvent will start an interval timer to wake up perl (and
2275	catch the signals) with soemd elay (default is 10 seconds, look for	2803	catch the signals) with some delay (default is 10 seconds, look for
2276	C<$AnyEvent::MAX_SIGNAL_LATENCY>).	2804	C<$AnyEvent::MAX_SIGNAL_LATENCY>).
2277		2805
2278	If this module is available, then it will be used to implement signal	2806	If this module is available, then it will be used to implement signal
2279	catching, which means that signals will not be delayed, and the event loop	2807	catching, which means that signals will not be delayed, and the event loop
2280	will not be interrupted regularly, which is more efficient (And good for	2808	will not be interrupted regularly, which is more efficient (and good for
2281	battery life on laptops).	2809	battery life on laptops).
2282		2810
2283	This affects not just the pure-perl event loop, but also other event loops	2811	This affects not just the pure-perl event loop, but also other event loops
2284	that have no signal handling on their own (e.g. Glib, Tk, Qt).	2812	that have no signal handling on their own (e.g. Glib, Tk, Qt).
		2813
		2814	Some event loops (POE, Event, Event::Lib) offer signal watchers natively,
		2815	and either employ their own workarounds (POE) or use AnyEvent's workaround
		2816	(using C<$AnyEvent::MAX_SIGNAL_LATENCY>). Installing L<Async::Interrupt>
		2817	does nothing for those backends.
2285		2818
2286	=item L<EV>	2819	=item L<EV>
2287		2820
2288	This module isn't really "optional", as it is simply one of the backend	2821	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	2822	event loops that AnyEvent can use. However, it is simply the best event
…		…
2292	automatic timer adjustments even when no monotonic clock is available,	2825	automatic timer adjustments even when no monotonic clock is available,
2293	can take avdantage of advanced kernel interfaces such as C<epoll> and	2826	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	2827	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>).	2828	L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>).
2296		2829
		2830	If you only use backends that rely on another event loop (e.g. C<Tk>),
		2831	then this module will do nothing for you.
		2832
2297	=item L<Guard>	2833	=item L<Guard>
2298		2834
2299	The guard module, when used, will be used to implement	2835	The guard module, when used, will be used to implement
2300	C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a	2836	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	2837	lot less memory), but otherwise doesn't affect guard operation much. It is
2302	purely used for performance.	2838	purely used for performance.
2303		2839
2304	=item L<JSON> and L<JSON::XS>	2840	=item L<JSON> and L<JSON::XS>
2305		2841
2306	This module is required when you want to read or write JSON data via	2842	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	2843	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.	2844	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		2845
2313	=item L<Net::SSLeay>	2846	=item L<Net::SSLeay>
2314		2847
2315	Implementing TLS/SSL in Perl is certainly interesting, but not very	2848	Implementing TLS/SSL in Perl is certainly interesting, but not very
2316	worthwhile: If this module is installed, then L<AnyEvent::Handle> (with	2849	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.	2850	the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL.
2318		2851
2319	=item L<Time::HiRes>	2852	=item L<Time::HiRes>
2320		2853
2321	This module is part of perl since release 5.008. It will be used when the	2854	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	2855	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	2856	pure-perl event loop (L<AnyEvent::Loop>) will additionally load it to
2324	try to use a monotonic clock for timing stability.	2857	try to use a monotonic clock for timing stability.
2325		2858
2326	=back	2859	=back
2327		2860
2328		2861
2329	=head1 FORK	2862	=head1 FORK
2330		2863
2331	Most event libraries are not fork-safe. The ones who are usually are	2864	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>	2865	because they rely on inefficient but fork-safe C<select> or C<poll> calls
2333	calls. Only L<EV> is fully fork-aware.	2866	- higher performance APIs such as BSD's kqueue or the dreaded Linux epoll
		2867	are usually badly thought-out hacks that are incompatible with fork in
		2868	one way or another. Only L<EV> is fully fork-aware and ensures that you
		2869	continue event-processing in both parent and child (or both, if you know
		2870	what you are doing).
		2871
		2872	This means that, in general, you cannot fork and do event processing in
		2873	the child if the event library was initialised before the fork (which
		2874	usually happens when the first AnyEvent watcher is created, or the library
		2875	is loaded).
2334		2876
2335	If you have to fork, you must either do so I<before> creating your first	2877	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	2878	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.	2879	something completely out of the scope of AnyEvent.
		2880
		2881	The problem of doing event processing in the parent I<and> the child
		2882	is much more complicated: even for backends that I<are> fork-aware or
		2883	fork-safe, their behaviour is not usually what you want: fork clones all
		2884	watchers, that means all timers, I/O watchers etc. are active in both
		2885	parent and child, which is almost never what you want. USing C<exec>
		2886	to start worker children from some kind of manage rprocess is usually
		2887	preferred, because it is much easier and cleaner, at the expense of having
		2888	to have another binary.
2338		2889
2339		2890
2340	=head1 SECURITY CONSIDERATIONS	2891	=head1 SECURITY CONSIDERATIONS
2341		2892
2342	AnyEvent can be forced to load any event model via	2893	AnyEvent can be forced to load any event model via
…		…
2372	pronounced).	2923	pronounced).
2373		2924
2374		2925
2375	=head1 SEE ALSO	2926	=head1 SEE ALSO
2376		2927
2377	Utility functions: L<AnyEvent::Util>.	2928	Tutorial/Introduction: L<AnyEvent::Intro>.
2378		2929
2379	Event modules: L<EV>, L<EV::Glib>, L<Glib::EV>, L<Event>, L<Glib::Event>,	2930	FAQ: L<AnyEvent::FAQ>.
2380	L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.	2931
		2932	Utility functions: L<AnyEvent::Util> (misc. grab-bag), L<AnyEvent::Log>
		2933	(simply logging).
		2934
		2935	Development/Debugging: L<AnyEvent::Strict> (stricter checking),
		2936	L<AnyEvent::Debug> (interactive shell, watcher tracing).
		2937
		2938	Supported event modules: L<AnyEvent::Loop>, L<EV>, L<EV::Glib>,
		2939	L<Glib::EV>, L<Event>, L<Glib::Event>, L<Glib>, L<Tk>, L<Event::Lib>,
		2940	L<Qt>, L<POE>, L<FLTK>.
2381		2941
2382	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,	2942	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,
2383	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,	2943	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,
2384	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,	2944	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,
2385	L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>.	2945	L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>, L<Anyevent::Impl::Irssi>,
		2946	L<AnyEvent::Impl::FLTK>.
2386		2947
2387	Non-blocking file handles, sockets, TCP clients and	2948	Non-blocking handles, pipes, stream sockets, TCP clients and
2388	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.	2949	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.
2389		2950
2390	Asynchronous DNS: L<AnyEvent::DNS>.	2951	Asynchronous DNS: L<AnyEvent::DNS>.
2391		2952
2392	Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>,	2953	Thread support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>.
2393	L<Coro::Event>,
2394		2954
2395	Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::XMPP>,	2955	Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::IRC>,
2396	L<AnyEvent::HTTP>.	2956	L<AnyEvent::HTTP>.
2397		2957
2398		2958
2399	=head1 AUTHOR	2959	=head1 AUTHOR
2400		2960

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