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Revision 1.379 by root, Fri Aug 26 18:09:04 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.
		1064
		1065	If you want to sprinkle loads of logging calls around your code, consider
		1066	creating a logger callback with the C<AnyEvent::Log::logger> function,
		1067	which can reduce typing, codesize and can reduce the logging overhead
		1068	enourmously.
		1069
891	=back	1070	=back
892		1071
893	=head1 WHAT TO DO IN A MODULE	1072	=head1 WHAT TO DO IN A MODULE
894		1073
895	As a module author, you should C<use AnyEvent> and call AnyEvent methods	1074	As a module author, you should C<use AnyEvent> and call AnyEvent methods
…		…
905	because it will stall the whole program, and the whole point of using	1084	because it will stall the whole program, and the whole point of using
906	events is to stay interactive.	1085	events is to stay interactive.
907		1086
908	It is fine, however, to call C<< ->recv >> when the user of your module	1087	It is fine, however, to call C<< ->recv >> when the user of your module
909	requests it (i.e. if you create a http request object ad have a method	1088	requests it (i.e. if you create a http request object ad have a method
910	called C<results> that returns the results, it should call C<< ->recv >>	1089	called C<results> that returns the results, it may call C<< ->recv >>
911	freely, as the user of your module knows what she is doing. always).	1090	freely, as the user of your module knows what she is doing. Always).
912		1091
913	=head1 WHAT TO DO IN THE MAIN PROGRAM	1092	=head1 WHAT TO DO IN THE MAIN PROGRAM
914		1093
915	There will always be a single main program - the only place that should	1094	There will always be a single main program - the only place that should
916	dictate which event model to use.	1095	dictate which event model to use.
917		1096
918	If it doesn't care, it can just "use AnyEvent" and use it itself, or not	1097	If the program is not event-based, it need not do anything special, even
919	do anything special (it does not need to be event-based) and let AnyEvent	1098	when it depends on a module that uses an AnyEvent. If the program itself
920	decide which implementation to chose if some module relies on it.	1099	uses AnyEvent, but does not care which event loop is used, all it needs
		1100	to do is C<use AnyEvent>. In either case, AnyEvent will choose the best
		1101	available loop implementation.
921		1102
922	If the main program relies on a specific event model - for example, in	1103	If the main program relies on a specific event model - for example, in
923	Gtk2 programs you have to rely on the Glib module - you should load the	1104	Gtk2 programs you have to rely on the Glib module - you should load the
924	event module before loading AnyEvent or any module that uses it: generally	1105	event module before loading AnyEvent or any module that uses it: generally
925	speaking, you should load it as early as possible. The reason is that	1106	speaking, you should load it as early as possible. The reason is that
926	modules might create watchers when they are loaded, and AnyEvent will	1107	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	1108	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.	1109	might choose the wrong one unless you load the correct one yourself.
929		1110
930	You can chose to use a pure-perl implementation by loading the	1111	You can chose to use a pure-perl implementation by loading the
931	C<AnyEvent::Impl::Perl> module, which gives you similar behaviour	1112	C<AnyEvent::Loop> module, which gives you similar behaviour
932	everywhere, but letting AnyEvent chose the model is generally better.	1113	everywhere, but letting AnyEvent chose the model is generally better.
933		1114
934	=head2 MAINLOOP EMULATION	1115	=head2 MAINLOOP EMULATION
935		1116
936	Sometimes (often for short test scripts, or even standalone programs who	1117	Sometimes (often for short test scripts, or even standalone programs who
…		…
949		1130
950		1131
951	=head1 OTHER MODULES	1132	=head1 OTHER MODULES
952		1133
953	The following is a non-exhaustive list of additional modules that use	1134	The following is a non-exhaustive list of additional modules that use
954	AnyEvent as a client and can therefore be mixed easily with other AnyEvent	1135	AnyEvent as a client and can therefore be mixed easily with other
955	modules and other event loops in the same program. Some of the modules	1136	AnyEvent modules and other event loops in the same program. Some of the
956	come with AnyEvent, most are available via CPAN.	1137	modules come as part of AnyEvent, the others are available via CPAN (see
		1138	L<http://search.cpan.org/search?m=module&q=anyevent%3A%3A*> for
		1139	a longer non-exhaustive list), and the list is heavily biased towards
		1140	modules of the AnyEvent author himself :)
957		1141
958	=over 4	1142	=over 4
959		1143
960	=item L<AnyEvent::Util>	1144	=item L<AnyEvent::Util>
961		1145
962	Contains various utility functions that replace often-used but blocking	1146	Contains various utility functions that replace often-used blocking
963	functions such as C<inet_aton> by event-/callback-based versions.	1147	functions such as C<inet_aton> with event/callback-based versions.
964		1148
965	=item L<AnyEvent::Socket>	1149	=item L<AnyEvent::Socket>
966		1150
967	Provides various utility functions for (internet protocol) sockets,	1151	Provides various utility functions for (internet protocol) sockets,
968	addresses and name resolution. Also functions to create non-blocking tcp	1152	addresses and name resolution. Also functions to create non-blocking tcp
…		…
970		1154
971	=item L<AnyEvent::Handle>	1155	=item L<AnyEvent::Handle>
972		1156
973	Provide read and write buffers, manages watchers for reads and writes,	1157	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	1158	supports raw and formatted I/O, I/O queued and fully transparent and
975	non-blocking SSL/TLS (via L<AnyEvent::TLS>.	1159	non-blocking SSL/TLS (via L<AnyEvent::TLS>).
976		1160
977	=item L<AnyEvent::DNS>	1161	=item L<AnyEvent::DNS>
978		1162
979	Provides rich asynchronous DNS resolver capabilities.	1163	Provides rich asynchronous DNS resolver capabilities.
980		1164
		1165	=item L<AnyEvent::HTTP>, L<AnyEvent::IRC>, L<AnyEvent::XMPP>, L<AnyEvent::GPSD>, L<AnyEvent::IGS>, L<AnyEvent::FCP>
		1166
		1167	Implement event-based interfaces to the protocols of the same name (for
		1168	the curious, IGS is the International Go Server and FCP is the Freenet
		1169	Client Protocol).
		1170
981	=item L<AnyEvent::HTTP>	1171	=item L<AnyEvent::AIO>
982		1172
983	A simple-to-use HTTP library that is capable of making a lot of concurrent	1173	Truly asynchronous (as opposed to non-blocking) I/O, should be in the
984	HTTP requests.	1174	toolbox of every event programmer. AnyEvent::AIO transparently fuses
		1175	L<IO::AIO> and AnyEvent together, giving AnyEvent access to event-based
		1176	file I/O, and much more.
		1177
		1178	=item L<AnyEvent::Filesys::Notify>
		1179
		1180	AnyEvent is good for non-blocking stuff, but it can't detect file or
		1181	path changes (e.g. "watch this directory for new files", "watch this
		1182	file for changes"). The L<AnyEvent::Filesys::Notify> module promises to
		1183	do just that in a portbale fashion, supporting inotify on GNU/Linux and
		1184	some weird, without doubt broken, stuff on OS X to monitor files. It can
		1185	fall back to blocking scans at regular intervals transparently on other
		1186	platforms, so it's about as portable as it gets.
		1187
		1188	(I haven't used it myself, but I haven't heard anybody complaining about
		1189	it yet).
		1190
		1191	=item L<AnyEvent::DBI>
		1192
		1193	Executes L<DBI> requests asynchronously in a proxy process for you,
		1194	notifying you in an event-based way when the operation is finished.
985		1195
986	=item L<AnyEvent::HTTPD>	1196	=item L<AnyEvent::HTTPD>
987		1197
988	Provides a simple web application server framework.	1198	A simple embedded webserver.
989		1199
990	=item L<AnyEvent::FastPing>	1200	=item L<AnyEvent::FastPing>
991		1201
992	The fastest ping in the west.	1202	The fastest ping in the west.
993		1203
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>	1204	=item L<Coro>
1037		1205
1038	Has special support for AnyEvent via L<Coro::AnyEvent>.	1206	Has special support for AnyEvent via L<Coro::AnyEvent>, which allows you
		1207	to simply invert the flow control - don't call us, we will call you:
		1208
		1209	async {
		1210	Coro::AnyEvent::sleep 5; # creates a 5s timer and waits for it
		1211	print "5 seconds later!\n";
		1212
		1213	Coro::AnyEvent::readable *STDIN; # uses an I/O watcher
		1214	my $line = <STDIN>; # works for ttys
		1215
		1216	AnyEvent::HTTP::http_get "url", Coro::rouse_cb;
		1217	my ($body, $hdr) = Coro::rouse_wait;
		1218	};
1039		1219
1040	=back	1220	=back
1041		1221
1042	=cut	1222	=cut
1043		1223
1044	package AnyEvent;	1224	package AnyEvent;
1045		1225
1046	# basically a tuned-down version of common::sense	1226	# basically a tuned-down version of common::sense
1047	sub common_sense {	1227	sub common_sense {
1048	# no warnings	1228	# from common:.sense 3.4
1049	${^WARNING_BITS} ^= ${^WARNING_BITS};	1229	${^WARNING_BITS} ^= ${^WARNING_BITS} ^ "\x3c\x3f\x33\x00\x0f\xf0\x0f\xc0\xf0\xfc\x33\x00";
1050	# use strict vars subs	1230	# use strict vars subs - NO UTF-8, as Util.pm doesn't like this atm. (uts46data.pl)
1051	$^H |= 0x00000600;	1231	$^H |= 0x00000600;
1052	}	1232	}
1053		1233
1054	BEGIN { AnyEvent::common_sense }	1234	BEGIN { AnyEvent::common_sense }
1055		1235
1056	use Carp ();	1236	use Carp ();
1057		1237
1058	our $VERSION = 4.83;	1238	our $VERSION = '6.02';
1059	our $MODEL;	1239	our $MODEL;
1060		1240
1061	our $AUTOLOAD;
1062	our @ISA;	1241	our @ISA;
1063		1242
1064	our @REGISTRY;	1243	our @REGISTRY;
1065		1244
1066	our $WIN32;
1067
1068	our $VERBOSE;	1245	our $VERBOSE;
1069		1246
1070	BEGIN {	1247	BEGIN {
1071	eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }";	1248	require "AnyEvent/constants.pl";
		1249
1072	eval "sub TAINT(){ " . (${^TAINT}*1) . " }";	1250	eval "sub TAINT (){" . (${^TAINT}*1) . "}";
1073		1251
1074	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}	1252	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}
1075	if ${^TAINT};	1253	if ${^TAINT};
1076		1254
		1255	$ENV{"PERL_ANYEVENT_$_"} = $ENV{"AE_$_"}
		1256	for grep s/^AE_// && !exists $ENV{"PERL_ANYEVENT_$_"}, keys %ENV;
		1257
		1258	@ENV{grep /^PERL_ANYEVENT_/, keys %ENV} = ()
		1259	if ${^TAINT};
		1260
1077	$VERBOSE = $ENV{PERL_ANYEVENT_VERBOSE}*1;	1261	$VERBOSE = $ENV{PERL_ANYEVENT_VERBOSE}*1;
1078
1079	}	1262	}
1080		1263
1081	our $MAX_SIGNAL_LATENCY = 10;	1264	our $MAX_SIGNAL_LATENCY = 10;
1082		1265
1083	our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred	1266	our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred
…		…
1087	$PROTOCOL{$_} = ++$idx	1270	$PROTOCOL{$_} = ++$idx
1088	for reverse split /\s*,\s*/,	1271	for reverse split /\s*,\s*/,
1089	$ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";	1272	$ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";
1090	}	1273	}
1091		1274
		1275	our @post_detect;
		1276
		1277	sub post_detect(&) {
		1278	my ($cb) = @_;
		1279
		1280	push @post_detect, $cb;
		1281
		1282	defined wantarray
		1283	? bless \$cb, "AnyEvent::Util::postdetect"
		1284	: ()
		1285	}
		1286
		1287	sub AnyEvent::Util::postdetect::DESTROY {
		1288	@post_detect = grep $_ != ${$_[0]}, @post_detect;
		1289	}
		1290
		1291	our $POSTPONE_W;
		1292	our @POSTPONE;
		1293
		1294	sub _postpone_exec {
		1295	undef $POSTPONE_W;
		1296
		1297	&{ shift @POSTPONE }
		1298	while @POSTPONE;
		1299	}
		1300
		1301	sub postpone(&) {
		1302	push @POSTPONE, shift;
		1303
		1304	$POSTPONE_W ||= AE::timer (0, 0, \&_postpone_exec);
		1305
		1306	()
		1307	}
		1308
		1309	sub log($$;@) {
		1310	# only load the big bloated module when we actually are about to log something
		1311	if ($_[0] <= $VERBOSE) { # also catches non-numeric levels(!)
		1312	require AnyEvent::Log;
		1313	# AnyEvent::Log overwrites this function
		1314	goto &log;
		1315	}
		1316
		1317	0 # not logged
		1318	}
		1319
		1320	if (length $ENV{PERL_ANYEVENT_LOG}) {
		1321	require AnyEvent::Log; # AnyEvent::Log does the thing for us
		1322	}
		1323
1092	my @models = (	1324	our @models = (
1093	[EV:: => AnyEvent::Impl::EV::],	1325	[EV:: => AnyEvent::Impl::EV:: , 1],
1094	[Event:: => AnyEvent::Impl::Event::],	1326	[AnyEvent::Loop:: => AnyEvent::Impl::Perl:: , 1],
1095	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::],
1096	# everything below here will not be autoprobed	1327	# everything below here will not (normally) be autoprobed
1097	# as the pureperl backend should work everywhere	1328	# as the pure perl backend should work everywhere
1098	# and is usually faster	1329	# and is usually faster
		1330	[Event:: => AnyEvent::Impl::Event::, 1],
1099	[Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers	1331	[Glib:: => AnyEvent::Impl::Glib:: , 1], # becomes extremely slow with many watchers
1100	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy	1332	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
		1333	[Irssi:: => AnyEvent::Impl::Irssi::], # Irssi has a bogus "Event" package
1101	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles	1334	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
1102	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program	1335	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program
1103	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza	1336	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
1104	[Wx:: => AnyEvent::Impl::POE::],	1337	[Wx:: => AnyEvent::Impl::POE::],
1105	[Prima:: => AnyEvent::Impl::POE::],	1338	[Prima:: => AnyEvent::Impl::POE::],
1106	# IO::Async is just too broken - we would need workarounds for its	1339	[IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # a bitch to autodetect
1107	# byzantine signal and broken child handling, among others.	1340	[Cocoa::EventLoop:: => AnyEvent::Impl::Cocoa::],
1108	# IO::Async is rather hard to detect, as it doesn't have any	1341	[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	);	1342	);
1114		1343
1115	our %method = map +($_ => 1),	1344	our @isa_hook;
		1345
		1346	sub _isa_set {
		1347	my @pkg = ("AnyEvent", (map $_->[0], grep defined, @isa_hook), $MODEL);
		1348
		1349	@{"$pkg[$_-1]::ISA"} = $pkg[$_]
		1350	for 1 .. $#pkg;
		1351
		1352	grep $_ && $_->[1], @isa_hook
		1353	and AE::_reset ();
		1354	}
		1355
		1356	# used for hooking AnyEvent::Strict and AnyEvent::Debug::Wrap into the class hierarchy
		1357	sub _isa_hook($$;$) {
		1358	my ($i, $pkg, $reset_ae) = @_;
		1359
		1360	$isa_hook[$i] = $pkg ? [$pkg, $reset_ae] : undef;
		1361
		1362	_isa_set;
		1363	}
		1364
		1365	# all autoloaded methods reserve the complete glob, not just the method slot.
		1366	# due to bugs in perls method cache implementation.
1116	qw(io timer time now now_update signal child idle condvar one_event DESTROY);	1367	our @methods = qw(io timer time now now_update signal child idle condvar);
1117		1368
1118	our @post_detect;
1119
1120	sub post_detect(&) {	1369	sub detect() {
1121	my ($cb) = @_;	1370	return $MODEL if $MODEL; # some programs keep references to detect
1122		1371
1123	if ($MODEL) {	1372	local $!; # for good measure
1124	$cb->();	1373	local $SIG{__DIE__}; # we use eval
1125		1374
1126	1	1375	# free some memory
		1376	*detect = sub () { $MODEL };
		1377	# undef &func doesn't correctly update the method cache. grmbl.
		1378	# so we delete the whole glob. grmbl.
		1379	# otoh, perl doesn't let me undef an active usb, but it lets me free
		1380	# a glob with an active sub. hrm. i hope it works, but perl is
		1381	# usually buggy in this department. sigh.
		1382	delete @{"AnyEvent::"}{@methods};
		1383	undef @methods;
		1384
		1385	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z0-9:]+)$/) {
		1386	my $model = $1;
		1387	$model = "AnyEvent::Impl::$model" unless $model =~ s/::$//;
		1388	if (eval "require $model") {
		1389	AnyEvent::log 7 => "loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.";
		1390	$MODEL = $model;
1127	} else {	1391	} else {
1128	push @post_detect, $cb;	1392	AnyEvent::log 5 => "unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@";
1129		1393	}
1130	defined wantarray
1131	? bless \$cb, "AnyEvent::Util::postdetect"
1132	: ()
1133	}	1394	}
1134	}
1135		1395
1136	sub AnyEvent::Util::postdetect::DESTROY {	1396	# check for already loaded models
1137	@post_detect = grep $_ != ${$_[0]}, @post_detect;
1138	}
1139
1140	sub detect() {
1141	unless ($MODEL) {	1397	unless ($MODEL) {
1142	local $SIG{__DIE__};	1398	for (@REGISTRY, @models) {
1143		1399	my ($package, $model) = @$_;
1144	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {	1400	if (${"$package\::VERSION"} > 0) {
1145	my $model = "AnyEvent::Impl::$1";
1146	if (eval "require $model") {	1401	if (eval "require $model") {
		1402	AnyEvent::log 7 => "autodetected model '$model', using it.";
1147	$MODEL = $model;	1403	$MODEL = $model;
1148	warn "AnyEvent: loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.\n" if $VERBOSE >= 2;	1404	last;
1149	} else {	1405	}
1150	warn "AnyEvent: unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@" if $VERBOSE;
1151	}	1406	}
1152	}	1407	}
1153		1408
1154	# check for already loaded models
1155	unless ($MODEL) {	1409	unless ($MODEL) {
		1410	# try to autoload a model
1156	for (@REGISTRY, @models) {	1411	for (@REGISTRY, @models) {
1157	my ($package, $model) = @$_;	1412	my ($package, $model, $autoload) = @$_;
		1413	if (
		1414	$autoload
		1415	and eval "require $package"
1158	if (${"$package\::VERSION"} > 0) {	1416	and ${"$package\::VERSION"} > 0
1159	if (eval "require $model") {	1417	and eval "require $model"
		1418	) {
		1419	AnyEvent::log 7 => "autoloaded model '$model', using it.";
1160	$MODEL = $model;	1420	$MODEL = $model;
1161	warn "AnyEvent: autodetected model '$model', using it.\n" if $VERBOSE >= 2;
1162	last;	1421	last;
1163	}
1164	}	1422	}
1165	}	1423	}
1166		1424
1167	unless ($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	1425	$MODEL
1182	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.\n";	1426	or die "AnyEvent: backend autodetection failed - did you properly install AnyEvent?";
1183	}
1184	}	1427	}
1185
1186	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
1187
1188	unshift @ISA, $MODEL;
1189
1190	require AnyEvent::Strict if $ENV{PERL_ANYEVENT_STRICT};
1191
1192	(shift @post_detect)->() while @post_detect;
1193	}	1428	}
1194		1429
		1430	# free memory only needed for probing
		1431	undef @models;
		1432	undef @REGISTRY;
		1433
		1434	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
		1435
		1436	# now nuke some methods that are overridden by the backend.
		1437	# SUPER usage is not allowed in these.
		1438	for (qw(time signal child idle)) {
		1439	undef &{"AnyEvent::Base::$_"}
		1440	if defined &{"$MODEL\::$_"};
		1441	}
		1442
		1443	_isa_set;
		1444
		1445	# we're officially open!
		1446
		1447	if ($ENV{PERL_ANYEVENT_STRICT}) {
		1448	require AnyEvent::Strict;
		1449	}
		1450
		1451	if ($ENV{PERL_ANYEVENT_DEBUG_WRAP}) {
		1452	require AnyEvent::Debug;
		1453	AnyEvent::Debug::wrap ($ENV{PERL_ANYEVENT_DEBUG_WRAP});
		1454	}
		1455
		1456	if (length $ENV{PERL_ANYEVENT_DEBUG_SHELL}) {
		1457	require AnyEvent::Socket;
		1458	require AnyEvent::Debug;
		1459
		1460	my $shell = $ENV{PERL_ANYEVENT_DEBUG_SHELL};
		1461	$shell =~ s/\$\$/$$/g;
		1462
		1463	my ($host, $service) = AnyEvent::Socket::parse_hostport ($shell);
		1464	$AnyEvent::Debug::SHELL = AnyEvent::Debug::shell ($host, $service);
		1465	}
		1466
		1467	# now the anyevent environment is set up as the user told us to, so
		1468	# call the actual user code - post detects
		1469
		1470	(shift @post_detect)->() while @post_detect;
		1471	undef @post_detect;
		1472
		1473	*post_detect = sub(&) {
		1474	shift->();
		1475
		1476	undef
		1477	};
		1478
1195	$MODEL	1479	$MODEL
1196	}	1480	}
1197		1481
1198	sub AUTOLOAD {	1482	for my $name (@methods) {
1199	(my $func = $AUTOLOAD) =~ s/.*://;	1483	*$name = sub {
1200		1484	detect;
1201	$method{$func}	1485	# we use goto because
1202	or Carp::croak "$func: not a valid method for AnyEvent objects";	1486	# a) it makes the thunk more transparent
1203		1487	# b) it allows us to delete the thunk later
1204	detect unless $MODEL;	1488	goto &{ UNIVERSAL::can AnyEvent => "SUPER::$name" }
1205		1489	};
1206	my $class = shift;
1207	$class->$func (@_);
1208	}	1490	}
1209		1491
1210	# utility function to dup a filehandle. this is used by many backends	1492	# utility function to dup a filehandle. this is used by many backends
1211	# to support binding more than one watcher per filehandle (they usually	1493	# 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).	1494	# 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	1504	# we assume CLOEXEC is already set by perl in all important cases
1223		1505
1224	($fh2, $rw)	1506	($fh2, $rw)
1225	}	1507	}
1226		1508
		1509	=head1 SIMPLIFIED AE API
		1510
		1511	Starting with version 5.0, AnyEvent officially supports a second, much
		1512	simpler, API that is designed to reduce the calling, typing and memory
		1513	overhead by using function call syntax and a fixed number of parameters.
		1514
		1515	See the L<AE> manpage for details.
		1516
		1517	=cut
		1518
		1519	package AE;
		1520
		1521	our $VERSION = $AnyEvent::VERSION;
		1522
		1523	sub _reset() {
		1524	eval q{
		1525	# fall back to the main API by default - backends and AnyEvent::Base
		1526	# implementations can overwrite these.
		1527
		1528	sub io($$$) {
		1529	AnyEvent->io (fh => $_[0], poll => $_[1] ? "w" : "r", cb => $_[2])
		1530	}
		1531
		1532	sub timer($$$) {
		1533	AnyEvent->timer (after => $_[0], interval => $_[1], cb => $_[2])
		1534	}
		1535
		1536	sub signal($$) {
		1537	AnyEvent->signal (signal => $_[0], cb => $_[1])
		1538	}
		1539
		1540	sub child($$) {
		1541	AnyEvent->child (pid => $_[0], cb => $_[1])
		1542	}
		1543
		1544	sub idle($) {
		1545	AnyEvent->idle (cb => $_[0]);
		1546	}
		1547
		1548	sub cv(;&) {
		1549	AnyEvent->condvar (@_ ? (cb => $_[0]) : ())
		1550	}
		1551
		1552	sub now() {
		1553	AnyEvent->now
		1554	}
		1555
		1556	sub now_update() {
		1557	AnyEvent->now_update
		1558	}
		1559
		1560	sub time() {
		1561	AnyEvent->time
		1562	}
		1563
		1564	*postpone = \&AnyEvent::postpone;
		1565	*log = \&AnyEvent::log;
		1566	};
		1567	die if $@;
		1568	}
		1569
		1570	BEGIN { _reset }
		1571
1227	package AnyEvent::Base;	1572	package AnyEvent::Base;
1228		1573
1229	# default implementations for many methods	1574	# default implementations for many methods
1230		1575
1231	sub _time {	1576	sub time {
		1577	eval q{ # poor man's autoloading {}
1232	# probe for availability of Time::HiRes	1578	# probe for availability of Time::HiRes
1233	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {	1579	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {
1234	warn "AnyEvent: using Time::HiRes for sub-second timing accuracy.\n" if $VERBOSE >= 8;	1580	*time = sub { Time::HiRes::time () };
1235	*_time = \&Time::HiRes::time;	1581	*AE::time = \& Time::HiRes::time ;
		1582	*now = \&time;
		1583	AnyEvent::log 8 => "AnyEvent: using Time::HiRes for sub-second timing accuracy.";
1236	# if (eval "use POSIX (); (POSIX::times())...	1584	# if (eval "use POSIX (); (POSIX::times())...
1237	} else {	1585	} else {
		1586	*time = sub { CORE::time };
		1587	*AE::time = sub (){ CORE::time };
		1588	*now = \&time;
1238	warn "AnyEvent: using built-in time(), WARNING, no sub-second resolution!\n" if $VERBOSE;	1589	AnyEvent::log 3 => "using built-in time(), WARNING, no sub-second resolution!";
1239	*_time = sub { time }; # epic fail	1590	}
1240	}	1591	};
		1592	die if $@;
1241		1593
1242	&_time	1594	&time
1243	}	1595	}
1244		1596
1245	sub time { _time }	1597	*now = \&time;
1246	sub now { _time }
1247	sub now_update { }	1598	sub now_update { }
1248		1599
		1600	sub _poll {
		1601	Carp::croak "$AnyEvent::MODEL does not support blocking waits. Caught";
		1602	}
		1603
1249	# default implementation for ->condvar	1604	# default implementation for ->condvar
		1605	# in fact, the default should not be overwritten
1250		1606
1251	sub condvar {	1607	sub condvar {
		1608	eval q{ # poor man's autoloading {}
		1609	*condvar = sub {
1252	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"	1610	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"
		1611	};
		1612
		1613	*AE::cv = sub (;&) {
		1614	bless { @_ ? (_ae_cb => shift) : () }, "AnyEvent::CondVar"
		1615	};
		1616	};
		1617	die if $@;
		1618
		1619	&condvar
1253	}	1620	}
1254		1621
1255	# default implementation for ->signal	1622	# default implementation for ->signal
1256		1623
1257	our $HAVE_ASYNC_INTERRUPT;	1624	our $HAVE_ASYNC_INTERRUPT;
		1625
		1626	sub _have_async_interrupt() {
		1627	$HAVE_ASYNC_INTERRUPT = 1*(!$ENV{PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT}
		1628	&& eval "use Async::Interrupt 1.02 (); 1")
		1629	unless defined $HAVE_ASYNC_INTERRUPT;
		1630
		1631	$HAVE_ASYNC_INTERRUPT
		1632	}
		1633
1258	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);	1634	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);
1259	our (%SIG_ASY, %SIG_ASY_W);	1635	our (%SIG_ASY, %SIG_ASY_W);
1260	our ($SIG_COUNT, $SIG_TW);	1636	our ($SIG_COUNT, $SIG_TW);
1261		1637
1262	sub _signal_exec {	1638	# install a dummy wakeup watcher to reduce signal catching latency
1263	$HAVE_ASYNC_INTERRUPT	1639	# used by Impls
1264	? $SIGPIPE_R->drain	1640	sub _sig_add() {
1265	: sysread $SIGPIPE_R, my $dummy, 9;	1641	unless ($SIG_COUNT++) {
		1642	# try to align timer on a full-second boundary, if possible
		1643	my $NOW = AE::now;
1266		1644
1267	while (%SIG_EV) {	1645	$SIG_TW = AE::timer
1268	for (keys %SIG_EV) {	1646	$MAX_SIGNAL_LATENCY - ($NOW - int $NOW),
1269	delete $SIG_EV{$_};	1647	$MAX_SIGNAL_LATENCY,
1270	$_->() for values %{ $SIG_CB{$_} || {} };	1648	sub { } # just for the PERL_ASYNC_CHECK
1271	}	1649	;
1272	}	1650	}
1273	}	1651	}
1274		1652
1275	sub _signal {	1653	sub _sig_del {
1276	my (undef, %arg) = @_;
1277
1278	my $signal = uc $arg{signal}
1279	or Carp::croak "required option 'signal' is missing";
1280
1281	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
1282
1283	if ($HAVE_ASYNC_INTERRUPT) {
1284	# async::interrupt
1285
1286	$SIG_ASY{$signal} ||= do {
1287	my $asy = new Async::Interrupt
1288	cb => sub { undef $SIG_EV{$signal} },
1289	signal => $signal,
1290	pipe => [$SIGPIPE_R->filenos],
1291	;
1292	$asy->pipe_autodrain (0);
1293
1294	$asy
1295	};
1296
1297	} else {
1298	# pure perl
1299
1300	$SIG{$signal} ||= sub {
1301	local $!;
1302	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;
1303	undef $SIG_EV{$signal};
1304	};
1305
1306	# can't do signal processing without introducing races in pure perl,
1307	# so limit the signal latency.
1308	++$SIG_COUNT;
1309	$SIG_TW ||= AnyEvent->timer (
1310	after => $MAX_SIGNAL_LATENCY,
1311	interval => $MAX_SIGNAL_LATENCY,
1312	cb => sub { }, # just for the PERL_ASYNC_CHECK
1313	);
1314	}
1315
1316	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
1317	}
1318
1319	sub signal {
1320	# probe for availability of Async::Interrupt
1321	if (!$ENV{PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT} && eval "use Async::Interrupt 0.6 (); 1") {
1322	warn "AnyEvent: using Async::Interrupt for race-free signal handling.\n" if $VERBOSE >= 8;
1323
1324	$HAVE_ASYNC_INTERRUPT = 1;
1325	$SIGPIPE_R = new Async::Interrupt::EventPipe;
1326	$SIG_IO = AnyEvent->io (fh => $SIGPIPE_R->fileno, poll => "r", cb => \&_signal_exec);
1327
1328	} else {
1329	warn "AnyEvent: using emulated perl signal handling with latency timer.\n" if $VERBOSE >= 8;
1330
1331	require Fcntl;
1332
1333	if (AnyEvent::WIN32) {
1334	require AnyEvent::Util;
1335
1336	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
1337	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R) if $SIGPIPE_R;
1338	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W) if $SIGPIPE_W; # just in case
1339	} else {
1340	pipe $SIGPIPE_R, $SIGPIPE_W;
1341	fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R;
1342	fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case
1343
1344	# not strictly required, as $^F is normally 2, but let's make sure...
1345	fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
1346	fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
1347	}
1348
1349	$SIGPIPE_R
1350	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";
1351
1352	$SIG_IO = AnyEvent->io (fh => $SIGPIPE_R, poll => "r", cb => \&_signal_exec);
1353	}
1354
1355	*signal = \&_signal;
1356	&signal
1357	}
1358
1359	sub AnyEvent::Base::signal::DESTROY {
1360	my ($signal, $cb) = @{$_[0]};
1361
1362	undef $SIG_TW	1654	undef $SIG_TW
1363	unless --$SIG_COUNT;	1655	unless --$SIG_COUNT;
		1656	}
1364		1657
		1658	our $_sig_name_init; $_sig_name_init = sub {
		1659	eval q{ # poor man's autoloading {}
		1660	undef $_sig_name_init;
		1661
		1662	if (_have_async_interrupt) {
		1663	*sig2num = \&Async::Interrupt::sig2num;
		1664	*sig2name = \&Async::Interrupt::sig2name;
		1665	} else {
		1666	require Config;
		1667
		1668	my %signame2num;
		1669	@signame2num{ split ' ', $Config::Config{sig_name} }
		1670	= split ' ', $Config::Config{sig_num};
		1671
		1672	my @signum2name;
		1673	@signum2name[values %signame2num] = keys %signame2num;
		1674
		1675	*sig2num = sub($) {
		1676	$_[0] > 0 ? shift : $signame2num{+shift}
		1677	};
		1678	*sig2name = sub ($) {
		1679	$_[0] > 0 ? $signum2name[+shift] : shift
		1680	};
		1681	}
		1682	};
		1683	die if $@;
		1684	};
		1685
		1686	sub sig2num ($) { &$_sig_name_init; &sig2num }
		1687	sub sig2name($) { &$_sig_name_init; &sig2name }
		1688
		1689	sub signal {
		1690	eval q{ # poor man's autoloading {}
		1691	# probe for availability of Async::Interrupt
		1692	if (_have_async_interrupt) {
		1693	AnyEvent::log 8 => "using Async::Interrupt for race-free signal handling.";
		1694
		1695	$SIGPIPE_R = new Async::Interrupt::EventPipe;
		1696	$SIG_IO = AE::io $SIGPIPE_R->fileno, 0, \&_signal_exec;
		1697
		1698	} else {
		1699	AnyEvent::log 8 => "using emulated perl signal handling with latency timer.";
		1700
		1701	if (AnyEvent::WIN32) {
		1702	require AnyEvent::Util;
		1703
		1704	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
		1705	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R, 1) if $SIGPIPE_R;
		1706	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W, 1) if $SIGPIPE_W; # just in case
		1707	} else {
		1708	pipe $SIGPIPE_R, $SIGPIPE_W;
		1709	fcntl $SIGPIPE_R, AnyEvent::F_SETFL, AnyEvent::O_NONBLOCK if $SIGPIPE_R;
		1710	fcntl $SIGPIPE_W, AnyEvent::F_SETFL, AnyEvent::O_NONBLOCK if $SIGPIPE_W; # just in case
		1711
		1712	# not strictly required, as $^F is normally 2, but let's make sure...
		1713	fcntl $SIGPIPE_R, AnyEvent::F_SETFD, AnyEvent::FD_CLOEXEC;
		1714	fcntl $SIGPIPE_W, AnyEvent::F_SETFD, AnyEvent::FD_CLOEXEC;
		1715	}
		1716
		1717	$SIGPIPE_R
		1718	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";
		1719
		1720	$SIG_IO = AE::io $SIGPIPE_R, 0, \&_signal_exec;
		1721	}
		1722
		1723	*signal = $HAVE_ASYNC_INTERRUPT
		1724	? sub {
		1725	my (undef, %arg) = @_;
		1726
		1727	# async::interrupt
		1728	my $signal = sig2num $arg{signal};
		1729	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
		1730
		1731	$SIG_ASY{$signal} ||= new Async::Interrupt
		1732	cb => sub { undef $SIG_EV{$signal} },
		1733	signal => $signal,
		1734	pipe => [$SIGPIPE_R->filenos],
		1735	pipe_autodrain => 0,
		1736	;
		1737
		1738	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
		1739	}
		1740	: sub {
		1741	my (undef, %arg) = @_;
		1742
		1743	# pure perl
		1744	my $signal = sig2name $arg{signal};
		1745	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
		1746
		1747	$SIG{$signal} ||= sub {
		1748	local $!;
		1749	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;
		1750	undef $SIG_EV{$signal};
		1751	};
		1752
		1753	# can't do signal processing without introducing races in pure perl,
		1754	# so limit the signal latency.
		1755	_sig_add;
		1756
		1757	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
		1758	}
		1759	;
		1760
		1761	*AnyEvent::Base::signal::DESTROY = sub {
		1762	my ($signal, $cb) = @{$_[0]};
		1763
		1764	_sig_del;
		1765
1365	delete $SIG_CB{$signal}{$cb};	1766	delete $SIG_CB{$signal}{$cb};
1366		1767
		1768	$HAVE_ASYNC_INTERRUPT
		1769	? delete $SIG_ASY{$signal}
1367	# delete doesn't work with older perls - they then	1770	: # delete doesn't work with older perls - they then
1368	# print weird messages, or just unconditionally exit	1771	# print weird messages, or just unconditionally exit
1369	# instead of getting the default action.	1772	# instead of getting the default action.
1370	undef $SIG{$signal}	1773	undef $SIG{$signal}
1371	unless keys %{ $SIG_CB{$signal} };	1774	unless keys %{ $SIG_CB{$signal} };
		1775	};
		1776
		1777	*_signal_exec = sub {
		1778	$HAVE_ASYNC_INTERRUPT
		1779	? $SIGPIPE_R->drain
		1780	: sysread $SIGPIPE_R, (my $dummy), 9;
		1781
		1782	while (%SIG_EV) {
		1783	for (keys %SIG_EV) {
		1784	delete $SIG_EV{$_};
		1785	&$_ for values %{ $SIG_CB{$_} || {} };
		1786	}
		1787	}
		1788	};
		1789	};
		1790	die if $@;
		1791
		1792	&signal
1372	}	1793	}
1373		1794
1374	# default implementation for ->child	1795	# default implementation for ->child
1375		1796
1376	our %PID_CB;	1797	our %PID_CB;
1377	our $CHLD_W;	1798	our $CHLD_W;
1378	our $CHLD_DELAY_W;	1799	our $CHLD_DELAY_W;
1379	our $WNOHANG;
1380		1800
1381	sub _sigchld {	1801	# used by many Impl's
1382	while (0 < (my $pid = waitpid -1, $WNOHANG)) {	1802	sub _emit_childstatus($$) {
1383	$_->($pid, $?)	1803	my (undef, $rpid, $rstatus) = @_;
		1804
		1805	$_->($rpid, $rstatus)
1384	for values %{ $PID_CB{$pid} || {} },	1806	for values %{ $PID_CB{$rpid} || {} },
1385	values %{ $PID_CB{0} || {} };	1807	values %{ $PID_CB{0} || {} };
1386	}
1387	}	1808	}
1388		1809
1389	sub child {	1810	sub child {
		1811	eval q{ # poor man's autoloading {}
		1812	*_sigchld = sub {
		1813	my $pid;
		1814
		1815	AnyEvent->_emit_childstatus ($pid, $?)
		1816	while ($pid = waitpid -1, WNOHANG) > 0;
		1817	};
		1818
		1819	*child = sub {
1390	my (undef, %arg) = @_;	1820	my (undef, %arg) = @_;
1391		1821
1392	defined (my $pid = $arg{pid} + 0)	1822	my $pid = $arg{pid};
1393	or Carp::croak "required option 'pid' is missing";	1823	my $cb = $arg{cb};
1394		1824
1395	$PID_CB{$pid}{$arg{cb}} = $arg{cb};	1825	$PID_CB{$pid}{$cb+0} = $cb;
1396		1826
1397	# WNOHANG is almost cetrainly 1 everywhere
1398	$WNOHANG ||= $^O =~ /^(?:openbsd|netbsd|linux|freebsd|cygwin|MSWin32)$/
1399	? 1
1400	: eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1;
1401
1402	unless ($CHLD_W) {	1827	unless ($CHLD_W) {
1403	$CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld);	1828	$CHLD_W = AE::signal CHLD => \&_sigchld;
1404	# child could be a zombie already, so make at least one round	1829	# child could be a zombie already, so make at least one round
1405	&_sigchld;	1830	&_sigchld;
1406	}	1831	}
1407		1832
1408	bless [$pid, $arg{cb}], "AnyEvent::Base::child"	1833	bless [$pid, $cb+0], "AnyEvent::Base::child"
1409	}	1834	};
1410		1835
1411	sub AnyEvent::Base::child::DESTROY {	1836	*AnyEvent::Base::child::DESTROY = sub {
1412	my ($pid, $cb) = @{$_[0]};	1837	my ($pid, $icb) = @{$_[0]};
1413		1838
1414	delete $PID_CB{$pid}{$cb};	1839	delete $PID_CB{$pid}{$icb};
1415	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };	1840	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };
1416		1841
1417	undef $CHLD_W unless keys %PID_CB;	1842	undef $CHLD_W unless keys %PID_CB;
		1843	};
		1844	};
		1845	die if $@;
		1846
		1847	&child
1418	}	1848	}
1419		1849
1420	# idle emulation is done by simply using a timer, regardless	1850	# idle emulation is done by simply using a timer, regardless
1421	# of whether the process is idle or not, and not letting	1851	# of whether the process is idle or not, and not letting
1422	# the callback use more than 50% of the time.	1852	# the callback use more than 50% of the time.
1423	sub idle {	1853	sub idle {
		1854	eval q{ # poor man's autoloading {}
		1855	*idle = sub {
1424	my (undef, %arg) = @_;	1856	my (undef, %arg) = @_;
1425		1857
1426	my ($cb, $w, $rcb) = $arg{cb};	1858	my ($cb, $w, $rcb) = $arg{cb};
1427		1859
1428	$rcb = sub {	1860	$rcb = sub {
1429	if ($cb) {	1861	if ($cb) {
1430	$w = _time;	1862	$w = AE::time;
1431	&$cb;	1863	&$cb;
1432	$w = _time - $w;	1864	$w = AE::time - $w;
1433		1865
1434	# never use more then 50% of the time for the idle watcher,	1866	# never use more then 50% of the time for the idle watcher,
1435	# within some limits	1867	# within some limits
1436	$w = 0.0001 if $w < 0.0001;	1868	$w = 0.0001 if $w < 0.0001;
1437	$w = 5 if $w > 5;	1869	$w = 5 if $w > 5;
1438		1870
1439	$w = AnyEvent->timer (after => $w, cb => $rcb);	1871	$w = AE::timer $w, 0, $rcb;
1440	} else {	1872	} else {
1441	# clean up...	1873	# clean up...
1442	undef $w;	1874	undef $w;
1443	undef $rcb;	1875	undef $rcb;
		1876	}
		1877	};
		1878
		1879	$w = AE::timer 0.05, 0, $rcb;
		1880
		1881	bless \\$cb, "AnyEvent::Base::idle"
1444	}	1882	};
		1883
		1884	*AnyEvent::Base::idle::DESTROY = sub {
		1885	undef $${$_[0]};
		1886	};
1445	};	1887	};
		1888	die if $@;
1446		1889
1447	$w = AnyEvent->timer (after => 0.05, cb => $rcb);	1890	&idle
1448
1449	bless \\$cb, "AnyEvent::Base::idle"
1450	}
1451
1452	sub AnyEvent::Base::idle::DESTROY {
1453	undef $${$_[0]};
1454	}	1891	}
1455		1892
1456	package AnyEvent::CondVar;	1893	package AnyEvent::CondVar;
1457		1894
1458	our @ISA = AnyEvent::CondVar::Base::;	1895	our @ISA = AnyEvent::CondVar::Base::;
		1896
		1897	# only to be used for subclassing
		1898	sub new {
		1899	my $class = shift;
		1900	bless AnyEvent->condvar (@_), $class
		1901	}
1459		1902
1460	package AnyEvent::CondVar::Base;	1903	package AnyEvent::CondVar::Base;
1461		1904
1462	#use overload	1905	#use overload
1463	# '&{}' => sub { my $self = shift; sub { $self->send (@_) } },	1906	# '&{}' => sub { my $self = shift; sub { $self->send (@_) } },
…		…
1473		1916
1474	sub _send {	1917	sub _send {
1475	# nop	1918	# nop
1476	}	1919	}
1477		1920
		1921	sub _wait {
		1922	AnyEvent->_poll until $_[0]{_ae_sent};
		1923	}
		1924
1478	sub send {	1925	sub send {
1479	my $cv = shift;	1926	my $cv = shift;
1480	$cv->{_ae_sent} = [@_];	1927	$cv->{_ae_sent} = [@_];
1481	(delete $cv->{_ae_cb})->($cv) if $cv->{_ae_cb};	1928	(delete $cv->{_ae_cb})->($cv) if $cv->{_ae_cb};
1482	$cv->_send;	1929	$cv->_send;
…		…
1489		1936
1490	sub ready {	1937	sub ready {
1491	$_[0]{_ae_sent}	1938	$_[0]{_ae_sent}
1492	}	1939	}
1493		1940
1494	sub _wait {
1495	$WAITING
1496	and !$_[0]{_ae_sent}
1497	and Carp::croak "AnyEvent::CondVar: recursive blocking wait detected";
1498
1499	local $WAITING = 1;
1500	AnyEvent->one_event while !$_[0]{_ae_sent};
1501	}
1502
1503	sub recv {	1941	sub recv {
		1942	unless ($_[0]{_ae_sent}) {
		1943	$WAITING
		1944	and Carp::croak "AnyEvent::CondVar: recursive blocking wait attempted";
		1945
		1946	local $WAITING = 1;
1504	$_[0]->_wait;	1947	$_[0]->_wait;
		1948	}
1505		1949
1506	Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak};	1950	$_[0]{_ae_croak}
1507	wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0]	1951	and Carp::croak $_[0]{_ae_croak};
		1952
		1953	wantarray
		1954	? @{ $_[0]{_ae_sent} }
		1955	: $_[0]{_ae_sent}[0]
1508	}	1956	}
1509		1957
1510	sub cb {	1958	sub cb {
1511	$_[0]{_ae_cb} = $_[1] if @_ > 1;	1959	my $cv = shift;
		1960
		1961	@_
		1962	and $cv->{_ae_cb} = shift
		1963	and $cv->{_ae_sent}
		1964	and (delete $cv->{_ae_cb})->($cv);
		1965
1512	$_[0]{_ae_cb}	1966	$cv->{_ae_cb}
1513	}	1967	}
1514		1968
1515	sub begin {	1969	sub begin {
1516	++$_[0]{_ae_counter};	1970	++$_[0]{_ae_counter};
1517	$_[0]{_ae_end_cb} = $_[1] if @_ > 1;	1971	$_[0]{_ae_end_cb} = $_[1] if @_ > 1;
…		…
1522	&{ $_[0]{_ae_end_cb} || sub { $_[0]->send } };	1976	&{ $_[0]{_ae_end_cb} || sub { $_[0]->send } };
1523	}	1977	}
1524		1978
1525	# undocumented/compatibility with pre-3.4	1979	# undocumented/compatibility with pre-3.4
1526	*broadcast = \&send;	1980	*broadcast = \&send;
1527	*wait = \&_wait;	1981	*wait = \&recv;
1528		1982
1529	=head1 ERROR AND EXCEPTION HANDLING	1983	=head1 ERROR AND EXCEPTION HANDLING
1530		1984
1531	In general, AnyEvent does not do any error handling - it relies on the	1985	In general, AnyEvent does not do any error handling - it relies on the
1532	caller to do that if required. The L<AnyEvent::Strict> module (see also	1986	caller to do that if required. The L<AnyEvent::Strict> module (see also
…		…
1544	$Event/EV::DIED->() >>, L<Glib> uses C<< install_exception_handler >> and	1998	$Event/EV::DIED->() >>, L<Glib> uses C<< install_exception_handler >> and
1545	so on.	1999	so on.
1546		2000
1547	=head1 ENVIRONMENT VARIABLES	2001	=head1 ENVIRONMENT VARIABLES
1548		2002
1549	The following environment variables are used by this module or its	2003	AnyEvent supports a number of environment variables that tune the
1550	submodules.	2004	runtime behaviour. They are usually evaluated when AnyEvent is
		2005	loaded, initialised, or a submodule that uses them is loaded. Many of
		2006	them also cause AnyEvent to load additional modules - for example,
		2007	C<PERL_ANYEVENT_DEBUG_WRAP> causes the L<AnyEvent::Debug> module to be
		2008	loaded.
1551		2009
1552	Note that AnyEvent will remove I<all> environment variables starting with	2010	All the environment variables documented here start with
1553	C<PERL_ANYEVENT_> from C<%ENV> when it is loaded while taint mode is	2011	C<PERL_ANYEVENT_>, which is what AnyEvent considers its own
1554	enabled.	2012	namespace. Other modules are encouraged (but by no means required) to use
		2013	C<PERL_ANYEVENT_SUBMODULE> if they have registered the AnyEvent::Submodule
		2014	namespace on CPAN, for any submodule. For example, L<AnyEvent::HTTP> could
		2015	be expected to use C<PERL_ANYEVENT_HTTP_PROXY> (it should not access env
		2016	variables starting with C<AE_>, see below).
		2017
		2018	All variables can also be set via the C<AE_> prefix, that is, instead
		2019	of setting C<PERL_ANYEVENT_VERBOSE> you can also set C<AE_VERBOSE>. In
		2020	case there is a clash btween anyevent and another program that uses
		2021	C<AE_something> you can set the corresponding C<PERL_ANYEVENT_something>
		2022	variable to the empty string, as those variables take precedence.
		2023
		2024	When AnyEvent is first loaded, it copies all C<AE_xxx> env variables
		2025	to their C<PERL_ANYEVENT_xxx> counterpart unless that variable already
		2026	exists. If taint mode is on, then AnyEvent will remove I<all> environment
		2027	variables starting with C<PERL_ANYEVENT_> from C<%ENV> (or replace them
		2028	with C<undef> or the empty string, if the corresaponding C<AE_> variable
		2029	is set).
		2030
		2031	The exact algorithm is currently:
		2032
		2033	1. if taint mode enabled, delete all PERL_ANYEVENT_xyz variables from %ENV
		2034	2. copy over AE_xyz to PERL_ANYEVENT_xyz unless the latter alraedy exists
		2035	3. if taint mode enabled, set all PERL_ANYEVENT_xyz variables to undef.
		2036
		2037	This ensures that child processes will not see the C<AE_> variables.
		2038
		2039	The following environment variables are currently known to AnyEvent:
1555		2040
1556	=over 4	2041	=over 4
1557		2042
1558	=item C<PERL_ANYEVENT_VERBOSE>	2043	=item C<PERL_ANYEVENT_VERBOSE>
1559		2044
1560	By default, AnyEvent will be completely silent except in fatal	2045	By default, AnyEvent will be completely silent except in fatal
1561	conditions. You can set this environment variable to make AnyEvent more	2046	conditions. You can set this environment variable to make AnyEvent more
1562	talkative.	2047	talkative. 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.
1563		2050
1564	When set to C<1> or higher, causes AnyEvent to warn about unexpected	2051	When set to C<5> or higher (warn), causes AnyEvent to warn about unexpected
1565	conditions, such as not being able to load the event model specified by	2052	conditions, such as not being able to load the event model specified by
1566	C<PERL_ANYEVENT_MODEL>.	2053	C<PERL_ANYEVENT_MODEL>, or a guard callback throwing an exception - this
		2054	is the minimum recommended level.
1567		2055
1568	When set to C<2> or higher, cause AnyEvent to report to STDERR which event	2056	When set to C<7> or higher (info), cause AnyEvent to report which event model it
1569	model it chooses.	2057	chooses.
		2058
		2059	When set to C<8> or higher (debug), then AnyEvent will report extra information on
		2060	which optional modules it loads and how it implements certain features.
		2061
		2062	=item C<PERL_ANYEVENT_LOG>
		2063
		2064	Accepts rather complex logging specifications. For example, you could log
		2065	all C<debug> messages of some module to stderr, warnings and above to
		2066	stderr, and errors and above to syslog, with:
		2067
		2068	PERL_ANYEVENT_LOG=Some::Module=debug,+log:filter=warn,+%syslog:%syslog=error,syslog
		2069
		2070	For the rather extensive details, see L<AnyEvent::Log>.
		2071
		2072	This variable is evaluated when AnyEvent (or L<AnyEvent::Log>) is loaded,
		2073	so will take effect even before AnyEvent has initialised itself.
		2074
		2075	Note that specifying this environment variable causes the L<AnyEvent::Log>
		2076	module to be loaded, while C<PERL_ANYEVENT_VERBOSE> does not, so only
		2077	using the latter saves a few hundred kB of memory until the first message
		2078	is being logged.
1570		2079
1571	=item C<PERL_ANYEVENT_STRICT>	2080	=item C<PERL_ANYEVENT_STRICT>
1572		2081
1573	AnyEvent does not do much argument checking by default, as thorough	2082	AnyEvent does not do much argument checking by default, as thorough
1574	argument checking is very costly. Setting this variable to a true value	2083	argument checking is very costly. Setting this variable to a true value
…		…
1576	check the arguments passed to most method calls. If it finds any problems,	2085	check the arguments passed to most method calls. If it finds any problems,
1577	it will croak.	2086	it will croak.
1578		2087
1579	In other words, enables "strict" mode.	2088	In other words, enables "strict" mode.
1580		2089
1581	Unlike C<use strict> (or it's modern cousin, C<< use L<common::sense>	2090	Unlike C<use strict> (or its modern cousin, C<< use L<common::sense>
1582	>>, it is definitely recommended to keep it off in production. Keeping	2091	>>, it is definitely recommended to keep it off in production. Keeping
1583	C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs	2092	C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs
1584	can be very useful, however.	2093	can be very useful, however.
1585		2094
		2095	=item C<PERL_ANYEVENT_DEBUG_SHELL>
		2096
		2097	If this env variable is set, then its contents will be interpreted by
		2098	C<AnyEvent::Socket::parse_hostport> (after replacing every occurance of
		2099	C<$$> by the process pid) and an C<AnyEvent::Debug::shell> is bound on
		2100	that port. The shell object is saved in C<$AnyEvent::Debug::SHELL>.
		2101
		2102	This happens when the first watcher is created.
		2103
		2104	For example, to bind a debug shell on a unix domain socket in
		2105	F<< /tmp/debug<pid>.sock >>, you could use this:
		2106
		2107	PERL_ANYEVENT_DEBUG_SHELL=/tmp/debug\$\$.sock perlprog
		2108
		2109	Note that creating sockets in F</tmp> is very unsafe on multiuser
		2110	systems.
		2111
		2112	=item C<PERL_ANYEVENT_DEBUG_WRAP>
		2113
		2114	Can be set to C<0>, C<1> or C<2> and enables wrapping of all watchers for
		2115	debugging purposes. See C<AnyEvent::Debug::wrap> for details.
		2116
1586	=item C<PERL_ANYEVENT_MODEL>	2117	=item C<PERL_ANYEVENT_MODEL>
1587		2118
1588	This can be used to specify the event model to be used by AnyEvent, before	2119	This can be used to specify the event model to be used by AnyEvent, before
1589	auto detection and -probing kicks in. It must be a string consisting	2120	auto detection and -probing kicks in.
1590	entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended	2121
		2122	It normally is a string consisting entirely of ASCII letters (e.g. C<EV>
		2123	or C<IOAsync>). The string C<AnyEvent::Impl::> gets prepended and the
1591	and the resulting module name is loaded and if the load was successful,	2124	resulting module name is loaded and - if the load was successful - used as
1592	used as event model. If it fails to load AnyEvent will proceed with	2125	event model backend. If it fails to load then AnyEvent will proceed with
1593	auto detection and -probing.	2126	auto detection and -probing.
1594		2127
1595	This functionality might change in future versions.	2128	If the string ends with C<::> instead (e.g. C<AnyEvent::Impl::EV::>) then
		2129	nothing gets prepended and the module name is used as-is (hint: C<::> at
		2130	the end of a string designates a module name and quotes it appropriately).
1596		2131
1597	For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you	2132	For example, to force the pure perl model (L<AnyEvent::Loop::Perl>) you
1598	could start your program like this:	2133	could start your program like this:
1599		2134
1600	PERL_ANYEVENT_MODEL=Perl perl ...	2135	PERL_ANYEVENT_MODEL=Perl perl ...
1601		2136
1602	=item C<PERL_ANYEVENT_PROTOCOLS>	2137	=item C<PERL_ANYEVENT_PROTOCOLS>
…		…
1618	but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4>	2153	but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4>
1619	- only support IPv4, never try to resolve or contact IPv6	2154	- only support IPv4, never try to resolve or contact IPv6
1620	addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or	2155	addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or
1621	IPv6, but prefer IPv6 over IPv4.	2156	IPv6, but prefer IPv6 over IPv4.
1622		2157
		2158	=item C<PERL_ANYEVENT_HOSTS>
		2159
		2160	This variable, if specified, overrides the F</etc/hosts> file used by
		2161	L<AnyEvent::Socket>C<::resolve_sockaddr>, i.e. hosts aliases will be read
		2162	from that file instead.
		2163
1623	=item C<PERL_ANYEVENT_EDNS0>	2164	=item C<PERL_ANYEVENT_EDNS0>
1624		2165
1625	Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension	2166	Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension for
1626	for DNS. This extension is generally useful to reduce DNS traffic, but	2167	DNS. This extension is generally useful to reduce DNS traffic, especially
1627	some (broken) firewalls drop such DNS packets, which is why it is off by	2168	when DNSSEC is involved, but some (broken) firewalls drop such DNS
1628	default.	2169	packets, which is why it is off by default.
1629		2170
1630	Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce	2171	Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce
1631	EDNS0 in its DNS requests.	2172	EDNS0 in its DNS requests.
1632		2173
1633	=item C<PERL_ANYEVENT_MAX_FORKS>	2174	=item C<PERL_ANYEVENT_MAX_FORKS>
…		…
1641	resolver - this is the maximum number of parallel DNS requests that are	2182	resolver - this is the maximum number of parallel DNS requests that are
1642	sent to the DNS server.	2183	sent to the DNS server.
1643		2184
1644	=item C<PERL_ANYEVENT_RESOLV_CONF>	2185	=item C<PERL_ANYEVENT_RESOLV_CONF>
1645		2186
1646	The file to use instead of F</etc/resolv.conf> (or OS-specific	2187	The absolute path to a F<resolv.conf>-style file to use instead of
1647	configuration) in the default resolver. When set to the empty string, no	2188	F</etc/resolv.conf> (or the OS-specific configuration) in the default
1648	default config will be used.	2189	resolver, or the empty string to select the default configuration.
1649		2190
1650	=item C<PERL_ANYEVENT_CA_FILE>, C<PERL_ANYEVENT_CA_PATH>.	2191	=item C<PERL_ANYEVENT_CA_FILE>, C<PERL_ANYEVENT_CA_PATH>.
1651		2192
1652	When neither C<ca_file> nor C<ca_path> was specified during	2193	When neither C<ca_file> nor C<ca_path> was specified during
1653	L<AnyEvent::TLS> context creation, and either of these environment	2194	L<AnyEvent::TLS> context creation, and either of these environment
1654	variables exist, they will be used to specify CA certificate locations	2195	variables are nonempty, they will be used to specify CA certificate
1655	instead of a system-dependent default.	2196	locations instead of a system-dependent default.
		2197
		2198	=item C<PERL_ANYEVENT_AVOID_GUARD> and C<PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT>
		2199
		2200	When these are set to C<1>, then the respective modules are not
		2201	loaded. Mostly good for testing AnyEvent itself.
1656		2202
1657	=back	2203	=back
1658		2204
1659	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE	2205	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE
1660		2206
…		…
1718	warn "read: $input\n"; # output what has been read	2264	warn "read: $input\n"; # output what has been read
1719	$cv->send if $input =~ /^q/i; # quit program if /^q/i	2265	$cv->send if $input =~ /^q/i; # quit program if /^q/i
1720	},	2266	},
1721	);	2267	);
1722		2268
1723	my $time_watcher; # can only be used once
1724
1725	sub new_timer {
1726	$timer = AnyEvent->timer (after => 1, cb => sub {	2269	my $time_watcher = AnyEvent->timer (after => 1, interval => 1, cb => sub {
1727	warn "timeout\n"; # print 'timeout' about every second	2270	warn "timeout\n"; # print 'timeout' at most every second
1728	&new_timer; # and restart the time
1729	});	2271	});
1730	}
1731
1732	new_timer; # create first timer
1733		2272
1734	$cv->recv; # wait until user enters /^q/i	2273	$cv->recv; # wait until user enters /^q/i
1735		2274
1736	=head1 REAL-WORLD EXAMPLE	2275	=head1 REAL-WORLD EXAMPLE
1737		2276
…		…
1810		2349
1811	The actual code goes further and collects all errors (C<die>s, exceptions)	2350	The actual code goes further and collects all errors (C<die>s, exceptions)
1812	that occurred during request processing. The C<result> method detects	2351	that occurred during request processing. The C<result> method detects
1813	whether an exception as thrown (it is stored inside the $txn object)	2352	whether an exception as thrown (it is stored inside the $txn object)
1814	and just throws the exception, which means connection errors and other	2353	and just throws the exception, which means connection errors and other
1815	problems get reported tot he code that tries to use the result, not in a	2354	problems get reported to the code that tries to use the result, not in a
1816	random callback.	2355	random callback.
1817		2356
1818	All of this enables the following usage styles:	2357	All of this enables the following usage styles:
1819		2358
1820	1. Blocking:	2359	1. Blocking:
…		…
1868	through AnyEvent. The benchmark creates a lot of timers (with a zero	2407	through AnyEvent. The benchmark creates a lot of timers (with a zero
1869	timeout) and I/O watchers (watching STDOUT, a pty, to become writable,	2408	timeout) and I/O watchers (watching STDOUT, a pty, to become writable,
1870	which it is), lets them fire exactly once and destroys them again.	2409	which it is), lets them fire exactly once and destroys them again.
1871		2410
1872	Source code for this benchmark is found as F<eg/bench> in the AnyEvent	2411	Source code for this benchmark is found as F<eg/bench> in the AnyEvent
1873	distribution.	2412	distribution. It uses the L<AE> interface, which makes a real difference
		2413	for the EV and Perl backends only.
1874		2414
1875	=head3 Explanation of the columns	2415	=head3 Explanation of the columns
1876		2416
1877	I<watcher> is the number of event watchers created/destroyed. Since	2417	I<watcher> is the number of event watchers created/destroyed. Since
1878	different event models feature vastly different performances, each event	2418	different event models feature vastly different performances, each event
…		…
1899	watcher.	2439	watcher.
1900		2440
1901	=head3 Results	2441	=head3 Results
1902		2442
1903	name watchers bytes create invoke destroy comment	2443	name watchers bytes create invoke destroy comment
1904	EV/EV 400000 224 0.47 0.35 0.27 EV native interface	2444	EV/EV 100000 223 0.47 0.43 0.27 EV native interface
1905	EV/Any 100000 224 2.88 0.34 0.27 EV + AnyEvent watchers	2445	EV/Any 100000 223 0.48 0.42 0.26 EV + AnyEvent watchers
1906	CoroEV/Any 100000 224 2.85 0.35 0.28 coroutines + Coro::Signal	2446	Coro::EV/Any 100000 223 0.47 0.42 0.26 coroutines + Coro::Signal
1907	Perl/Any 100000 452 4.13 0.73 0.95 pure perl implementation	2447	Perl/Any 100000 431 2.70 0.74 0.92 pure perl implementation
1908	Event/Event 16000 517 32.20 31.80 0.81 Event native interface	2448	Event/Event 16000 516 31.16 31.84 0.82 Event native interface
1909	Event/Any 16000 590 35.85 31.55 1.06 Event + AnyEvent watchers	2449	Event/Any 16000 1203 42.61 34.79 1.80 Event + AnyEvent watchers
1910	IOAsync/Any 16000 989 38.10 32.77 11.13 via IO::Async::Loop::IO_Poll	2450	IOAsync/Any 16000 1911 41.92 27.45 16.81 via IO::Async::Loop::IO_Poll
1911	IOAsync/Any 16000 990 37.59 29.50 10.61 via IO::Async::Loop::Epoll	2451	IOAsync/Any 16000 1726 40.69 26.37 15.25 via IO::Async::Loop::Epoll
1912	Glib/Any 16000 1357 102.33 12.31 51.00 quadratic behaviour	2452	Glib/Any 16000 1118 89.00 12.57 51.17 quadratic behaviour
1913	Tk/Any 2000 1860 27.20 66.31 14.00 SEGV with >> 2000 watchers	2453	Tk/Any 2000 1346 20.96 10.75 8.00 SEGV with >> 2000 watchers
1914	POE/Event 2000 6328 109.99 751.67 14.02 via POE::Loop::Event	2454	POE/Any 2000 6951 108.97 795.32 14.24 via POE::Loop::Event
1915	POE/Select 2000 6027 94.54 809.13 579.80 via POE::Loop::Select	2455	POE/Any 2000 6648 94.79 774.40 575.51 via POE::Loop::Select
1916		2456
1917	=head3 Discussion	2457	=head3 Discussion
1918		2458
1919	The benchmark does I<not> measure scalability of the event loop very	2459	The benchmark does I<not> measure scalability of the event loop very
1920	well. For example, a select-based event loop (such as the pure perl one)	2460	well. For example, a select-based event loop (such as the pure perl one)
…		…
1932	benchmark machine, handling an event takes roughly 1600 CPU cycles with	2472	benchmark machine, handling an event takes roughly 1600 CPU cycles with
1933	EV, 3100 CPU cycles with AnyEvent's pure perl loop and almost 3000000 CPU	2473	EV, 3100 CPU cycles with AnyEvent's pure perl loop and almost 3000000 CPU
1934	cycles with POE.	2474	cycles with POE.
1935		2475
1936	C<EV> is the sole leader regarding speed and memory use, which are both	2476	C<EV> is the sole leader regarding speed and memory use, which are both
1937	maximal/minimal, respectively. Even when going through AnyEvent, it uses	2477	maximal/minimal, respectively. When using the L<AE> API there is zero
		2478	overhead (when going through the AnyEvent API create is about 5-6 times
		2479	slower, with other times being equal, so still uses far less memory than
1938	far less memory than any other event loop and is still faster than Event	2480	any other event loop and is still faster than Event natively).
1939	natively.
1940		2481
1941	The pure perl implementation is hit in a few sweet spots (both the	2482	The pure perl implementation is hit in a few sweet spots (both the
1942	constant timeout and the use of a single fd hit optimisations in the perl	2483	constant timeout and the use of a single fd hit optimisations in the perl
1943	interpreter and the backend itself). Nevertheless this shows that it	2484	interpreter and the backend itself). Nevertheless this shows that it
1944	adds very little overhead in itself. Like any select-based backend its	2485	adds very little overhead in itself. Like any select-based backend its
…		…
1992	(even when used without AnyEvent), but most event loops have acceptable	2533	(even when used without AnyEvent), but most event loops have acceptable
1993	performance with or without AnyEvent.	2534	performance with or without AnyEvent.
1994		2535
1995	=item * The overhead AnyEvent adds is usually much smaller than the overhead of	2536	=item * The overhead AnyEvent adds is usually much smaller than the overhead of
1996	the actual event loop, only with extremely fast event loops such as EV	2537	the actual event loop, only with extremely fast event loops such as EV
1997	adds AnyEvent significant overhead.	2538	does AnyEvent add significant overhead.
1998		2539
1999	=item * You should avoid POE like the plague if you want performance or	2540	=item * You should avoid POE like the plague if you want performance or
2000	reasonable memory usage.	2541	reasonable memory usage.
2001		2542
2002	=back	2543	=back
…		…
2018	In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100	2559	In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100
2019	(1%) are active. This mirrors the activity of large servers with many	2560	(1%) are active. This mirrors the activity of large servers with many
2020	connections, most of which are idle at any one point in time.	2561	connections, most of which are idle at any one point in time.
2021		2562
2022	Source code for this benchmark is found as F<eg/bench2> in the AnyEvent	2563	Source code for this benchmark is found as F<eg/bench2> in the AnyEvent
2023	distribution.	2564	distribution. It uses the L<AE> interface, which makes a real difference
		2565	for the EV and Perl backends only.
2024		2566
2025	=head3 Explanation of the columns	2567	=head3 Explanation of the columns
2026		2568
2027	I<sockets> is the number of sockets, and twice the number of "servers" (as	2569	I<sockets> is the number of sockets, and twice the number of "servers" (as
2028	each server has a read and write socket end).	2570	each server has a read and write socket end).
…		…
2036	a new one that moves the timeout into the future.	2578	a new one that moves the timeout into the future.
2037		2579
2038	=head3 Results	2580	=head3 Results
2039		2581
2040	name sockets create request	2582	name sockets create request
2041	EV 20000 69.01 11.16	2583	EV 20000 62.66 7.99
2042	Perl 20000 73.32 35.87	2584	Perl 20000 68.32 32.64
2043	IOAsync 20000 157.00 98.14 epoll	2585	IOAsync 20000 174.06 101.15 epoll
2044	IOAsync 20000 159.31 616.06 poll	2586	IOAsync 20000 174.67 610.84 poll
2045	Event 20000 212.62 257.32	2587	Event 20000 202.69 242.91
2046	Glib 20000 651.16 1896.30	2588	Glib 20000 557.01 1689.52
2047	POE 20000 349.67 12317.24 uses POE::Loop::Event	2589	POE 20000 341.54 12086.32 uses POE::Loop::Event
2048		2590
2049	=head3 Discussion	2591	=head3 Discussion
2050		2592
2051	This benchmark I<does> measure scalability and overall performance of the	2593	This benchmark I<does> measure scalability and overall performance of the
2052	particular event loop.	2594	particular event loop.
…		…
2178	As you can see, the AnyEvent + EV combination even beats the	2720	As you can see, the AnyEvent + EV combination even beats the
2179	hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl	2721	hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl
2180	backend easily beats IO::Lambda and POE.	2722	backend easily beats IO::Lambda and POE.
2181		2723
2182	And even the 100% non-blocking version written using the high-level (and	2724	And even the 100% non-blocking version written using the high-level (and
2183	slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda by a	2725	slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda
2184	large margin, even though it does all of DNS, tcp-connect and socket I/O	2726	higher level ("unoptimised") abstractions by a large margin, even though
2185	in a non-blocking way.	2727	it does all of DNS, tcp-connect and socket I/O in a non-blocking way.
2186		2728
2187	The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and	2729	The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and
2188	F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are	2730	F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are
2189	part of the IO::lambda distribution and were used without any changes.	2731	part of the IO::Lambda distribution and were used without any changes.
2190		2732
2191		2733
2192	=head1 SIGNALS	2734	=head1 SIGNALS
2193		2735
2194	AnyEvent currently installs handlers for these signals:	2736	AnyEvent currently installs handlers for these signals:
…		…
2231	unless defined $SIG{PIPE};	2773	unless defined $SIG{PIPE};
2232		2774
2233	=head1 RECOMMENDED/OPTIONAL MODULES	2775	=head1 RECOMMENDED/OPTIONAL MODULES
2234		2776
2235	One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and	2777	One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and
2236	it's built-in modules) are required to use it.	2778	its built-in modules) are required to use it.
2237		2779
2238	That does not mean that AnyEvent won't take advantage of some additional	2780	That does not mean that AnyEvent won't take advantage of some additional
2239	modules if they are installed.	2781	modules if they are installed.
2240		2782
2241	This section epxlains which additional modules will be used, and how they	2783	This section explains which additional modules will be used, and how they
2242	affect AnyEvent's operetion.	2784	affect AnyEvent's operation.
2243		2785
2244	=over 4	2786	=over 4
2245		2787
2246	=item L<Async::Interrupt>	2788	=item L<Async::Interrupt>
2247		2789
2248	This slightly arcane module is used to implement fast signal handling: To	2790	This slightly arcane module is used to implement fast signal handling: To
2249	my knowledge, there is no way to do completely race-free and quick	2791	my knowledge, there is no way to do completely race-free and quick
2250	signal handling in pure perl. To ensure that signals still get	2792	signal handling in pure perl. To ensure that signals still get
2251	delivered, AnyEvent will start an interval timer to wake up perl (and	2793	delivered, AnyEvent will start an interval timer to wake up perl (and
2252	catch the signals) with soemd elay (default is 10 seconds, look for	2794	catch the signals) with some delay (default is 10 seconds, look for
2253	C<$AnyEvent::MAX_SIGNAL_LATENCY>).	2795	C<$AnyEvent::MAX_SIGNAL_LATENCY>).
2254		2796
2255	If this module is available, then it will be used to implement signal	2797	If this module is available, then it will be used to implement signal
2256	catching, which means that signals will not be delayed, and the event loop	2798	catching, which means that signals will not be delayed, and the event loop
2257	will not be interrupted regularly, which is more efficient (And good for	2799	will not be interrupted regularly, which is more efficient (and good for
2258	battery life on laptops).	2800	battery life on laptops).
2259		2801
2260	This affects not just the pure-perl event loop, but also other event loops	2802	This affects not just the pure-perl event loop, but also other event loops
2261	that have no signal handling on their own (e.g. Glib, Tk, Qt).	2803	that have no signal handling on their own (e.g. Glib, Tk, Qt).
		2804
		2805	Some event loops (POE, Event, Event::Lib) offer signal watchers natively,
		2806	and either employ their own workarounds (POE) or use AnyEvent's workaround
		2807	(using C<$AnyEvent::MAX_SIGNAL_LATENCY>). Installing L<Async::Interrupt>
		2808	does nothing for those backends.
2262		2809
2263	=item L<EV>	2810	=item L<EV>
2264		2811
2265	This module isn't really "optional", as it is simply one of the backend	2812	This module isn't really "optional", as it is simply one of the backend
2266	event loops that AnyEvent can use. However, it is simply the best event	2813	event loops that AnyEvent can use. However, it is simply the best event
…		…
2269	automatic timer adjustments even when no monotonic clock is available,	2816	automatic timer adjustments even when no monotonic clock is available,
2270	can take avdantage of advanced kernel interfaces such as C<epoll> and	2817	can take avdantage of advanced kernel interfaces such as C<epoll> and
2271	C<kqueue>, and is the fastest backend I<by far>. You can even embed	2818	C<kqueue>, and is the fastest backend I<by far>. You can even embed
2272	L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>).	2819	L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>).
2273		2820
		2821	If you only use backends that rely on another event loop (e.g. C<Tk>),
		2822	then this module will do nothing for you.
		2823
2274	=item L<Guard>	2824	=item L<Guard>
2275		2825
2276	The guard module, when used, will be used to implement	2826	The guard module, when used, will be used to implement
2277	C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a	2827	C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a
2278	lot less memory), but otherwise doesn't affect guard operation much. It is	2828	lot less memory), but otherwise doesn't affect guard operation much. It is
2279	purely used for performance.	2829	purely used for performance.
2280		2830
2281	=item L<JSON> and L<JSON::XS>	2831	=item L<JSON> and L<JSON::XS>
2282		2832
2283	This module is required when you want to read or write JSON data via	2833	One of these modules is required when you want to read or write JSON data
2284	L<AnyEvent::Handle>. It is also written in pure-perl, but can take	2834	via L<AnyEvent::Handle>. L<JSON> is also written in pure-perl, but can take
2285	advantage of the ulta-high-speed L<JSON::XS> module when it is installed.	2835	advantage of the ultra-high-speed L<JSON::XS> module when it is installed.
2286
2287	In fact, L<AnyEvent::Handle> will use L<JSON::XS> by default if it is
2288	installed.
2289		2836
2290	=item L<Net::SSLeay>	2837	=item L<Net::SSLeay>
2291		2838
2292	Implementing TLS/SSL in Perl is certainly interesting, but not very	2839	Implementing TLS/SSL in Perl is certainly interesting, but not very
2293	worthwhile: If this module is installed, then L<AnyEvent::Handle> (with	2840	worthwhile: If this module is installed, then L<AnyEvent::Handle> (with
2294	the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL.	2841	the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL.
2295		2842
2296	=item L<Time::HiRes>	2843	=item L<Time::HiRes>
2297		2844
2298	This module is part of perl since release 5.008. It will be used when the	2845	This module is part of perl since release 5.008. It will be used when the
2299	chosen event library does not come with a timing source on it's own. The	2846	chosen event library does not come with a timing source of its own. The
2300	pure-perl event loop (L<AnyEvent::Impl::Perl>) will additionally use it to	2847	pure-perl event loop (L<AnyEvent::Loop>) will additionally load it to
2301	try to use a monotonic clock for timing stability.	2848	try to use a monotonic clock for timing stability.
2302		2849
2303	=back	2850	=back
2304		2851
2305		2852
2306	=head1 FORK	2853	=head1 FORK
2307		2854
2308	Most event libraries are not fork-safe. The ones who are usually are	2855	Most event libraries are not fork-safe. The ones who are usually are
2309	because they rely on inefficient but fork-safe C<select> or C<poll>	2856	because they rely on inefficient but fork-safe C<select> or C<poll> calls
2310	calls. Only L<EV> is fully fork-aware.	2857	- higher performance APIs such as BSD's kqueue or the dreaded Linux epoll
		2858	are usually badly thought-out hacks that are incompatible with fork in
		2859	one way or another. Only L<EV> is fully fork-aware and ensures that you
		2860	continue event-processing in both parent and child (or both, if you know
		2861	what you are doing).
		2862
		2863	This means that, in general, you cannot fork and do event processing in
		2864	the child if the event library was initialised before the fork (which
		2865	usually happens when the first AnyEvent watcher is created, or the library
		2866	is loaded).
2311		2867
2312	If you have to fork, you must either do so I<before> creating your first	2868	If you have to fork, you must either do so I<before> creating your first
2313	watcher OR you must not use AnyEvent at all in the child OR you must do	2869	watcher OR you must not use AnyEvent at all in the child OR you must do
2314	something completely out of the scope of AnyEvent.	2870	something completely out of the scope of AnyEvent.
		2871
		2872	The problem of doing event processing in the parent I<and> the child
		2873	is much more complicated: even for backends that I<are> fork-aware or
		2874	fork-safe, their behaviour is not usually what you want: fork clones all
		2875	watchers, that means all timers, I/O watchers etc. are active in both
		2876	parent and child, which is almost never what you want. USing C<exec>
		2877	to start worker children from some kind of manage rprocess is usually
		2878	preferred, because it is much easier and cleaner, at the expense of having
		2879	to have another binary.
2315		2880
2316		2881
2317	=head1 SECURITY CONSIDERATIONS	2882	=head1 SECURITY CONSIDERATIONS
2318		2883
2319	AnyEvent can be forced to load any event model via	2884	AnyEvent can be forced to load any event model via
…		…
2349	pronounced).	2914	pronounced).
2350		2915
2351		2916
2352	=head1 SEE ALSO	2917	=head1 SEE ALSO
2353		2918
2354	Utility functions: L<AnyEvent::Util>.	2919	Tutorial/Introduction: L<AnyEvent::Intro>.
2355		2920
2356	Event modules: L<EV>, L<EV::Glib>, L<Glib::EV>, L<Event>, L<Glib::Event>,	2921	FAQ: L<AnyEvent::FAQ>.
2357	L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.	2922
		2923	Utility functions: L<AnyEvent::Util> (misc. grab-bag), L<AnyEvent::Log>
		2924	(simply logging).
		2925
		2926	Development/Debugging: L<AnyEvent::Strict> (stricter checking),
		2927	L<AnyEvent::Debug> (interactive shell, watcher tracing).
		2928
		2929	Supported event modules: L<AnyEvent::Loop>, L<EV>, L<EV::Glib>,
		2930	L<Glib::EV>, L<Event>, L<Glib::Event>, L<Glib>, L<Tk>, L<Event::Lib>,
		2931	L<Qt>, L<POE>, L<FLTK>.
2358		2932
2359	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,	2933	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,
2360	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,	2934	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,
2361	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,	2935	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,
2362	L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>.	2936	L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>, L<Anyevent::Impl::Irssi>,
		2937	L<AnyEvent::Impl::FLTK>.
2363		2938
2364	Non-blocking file handles, sockets, TCP clients and	2939	Non-blocking handles, pipes, stream sockets, TCP clients and
2365	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.	2940	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.
2366		2941
2367	Asynchronous DNS: L<AnyEvent::DNS>.	2942	Asynchronous DNS: L<AnyEvent::DNS>.
2368		2943
2369	Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>,	2944	Thread support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>.
2370	L<Coro::Event>,
2371		2945
2372	Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::XMPP>,	2946	Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::IRC>,
2373	L<AnyEvent::HTTP>.	2947	L<AnyEvent::HTTP>.
2374		2948
2375		2949
2376	=head1 AUTHOR	2950	=head1 AUTHOR
2377		2951

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