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Revision 1.250 by root, Mon Jul 20 07:12:38 2009 UTC vs.
Revision 1.352 by root, Thu Aug 4 09:14:01 2011 UTC

1	=head1 NAME	1	=head1 NAME
2		2
3	AnyEvent - events independent of event loop implementation	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	and POE are various supported event loops/environments.
7		7
8	=head1 SYNOPSIS	8	=head1 SYNOPSIS
9		9
10	use AnyEvent;	10	use AnyEvent;
11		11
		12	# if you prefer function calls, look at the AE manpage for
		13	# an alternative API.
		14
12	# file descriptor readable	15	# file handle or descriptor readable
13	my $w = AnyEvent->io (fh => $fh, poll => "r", cb => sub { ... });	16	my $w = AnyEvent->io (fh => $fh, poll => "r", cb => sub { ... });
14		17
15	# one-shot or repeating timers	18	# one-shot or repeating timers
16	my $w = AnyEvent->timer (after => $seconds, cb => sub { ... });	19	my $w = AnyEvent->timer (after => $seconds, cb => sub { ... });
17	my $w = AnyEvent->timer (after => $seconds, interval => $seconds, cb => ...	20	my $w = AnyEvent->timer (after => $seconds, interval => $seconds, cb => ...);
18		21
19	print AnyEvent->now; # prints current event loop time	22	print AnyEvent->now; # prints current event loop time
20	print AnyEvent->time; # think Time::HiRes::time or simply CORE::time.	23	print AnyEvent->time; # think Time::HiRes::time or simply CORE::time.
21		24
22	# POSIX signal	25	# POSIX signal
…		…
43	in a tutorial or some gentle introduction, have a look at the	46	in a tutorial or some gentle introduction, have a look at the
44	L<AnyEvent::Intro> manpage.	47	L<AnyEvent::Intro> manpage.
45		48
46	=head1 SUPPORT	49	=head1 SUPPORT
47		50
		51	An FAQ document is available as L<AnyEvent::FAQ>.
		52
48	There is a mailinglist for discussing all things AnyEvent, and an IRC	53	There also is a mailinglist for discussing all things AnyEvent, and an IRC
49	channel, too.	54	channel, too.
50		55
51	See the AnyEvent project page at the B<Schmorpforge Ta-Sa Software	56	See the AnyEvent project page at the B<Schmorpforge Ta-Sa Software
52	Respository>, at L<http://anyevent.schmorp.de>, for more info.	57	Repository>, at L<http://anyevent.schmorp.de>, for more info.
53		58
54	=head1 WHY YOU SHOULD USE THIS MODULE (OR NOT)	59	=head1 WHY YOU SHOULD USE THIS MODULE (OR NOT)
55		60
56	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
57	nowadays. So what is different about AnyEvent?	62	nowadays. So what is different about AnyEvent?
…		…
73	module users into the same thing by forcing them to use the same event	78	module users into the same thing by forcing them to use the same event
74	model you use.	79	model you use.
75		80
76	For modules like POE or IO::Async (which is a total misnomer as it is	81	For modules like POE or IO::Async (which is a total misnomer as it is
77	actually doing all I/O I<synchronously>...), using them in your module is	82	actually doing all I/O I<synchronously>...), using them in your module is
78	like joining a cult: After you joined, you are dependent on them and you	83	like joining a cult: After you join, you are dependent on them and you
79	cannot use anything else, as they are simply incompatible to everything	84	cannot use anything else, as they are simply incompatible to everything
80	that isn't them. What's worse, all the potential users of your	85	that isn't them. What's worse, all the potential users of your
81	module are I<also> forced to use the same event loop you use.	86	module are I<also> forced to use the same event loop you use.
82		87
83	AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works	88	AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works
84	fine. AnyEvent + Tk works fine etc. etc. but none of these work together	89	fine. AnyEvent + Tk works fine etc. etc. but none of these work together
85	with the rest: POE + IO::Async? No go. Tk + Event? No go. Again: if	90	with the rest: POE + EV? No go. Tk + Event? No go. Again: if your module
86	your module uses one of those, every user of your module has to use it,	91	uses one of those, every user of your module has to use it, too. But if
87	too. But if your module uses AnyEvent, it works transparently with all	92	your module uses AnyEvent, it works transparently with all event models it
88	event models it supports (including stuff like IO::Async, as long as those	93	supports (including stuff like IO::Async, as long as those use one of the
89	use one of the supported event loops. It is trivial to add new event loops	94	supported event loops. It is easy to add new event loops to AnyEvent, too,
90	to AnyEvent, too, so it is future-proof).	95	so it is future-proof).
91		96
92	In addition to being free of having to use I<the one and only true event	97	In addition to being free of having to use I<the one and only true event
93	model>, AnyEvent also is free of bloat and policy: with POE or similar	98	model>, AnyEvent also is free of bloat and policy: with POE or similar
94	modules, you get an enormous amount of code and strict rules you have to	99	modules, you get an enormous amount of code and strict rules you have to
95	follow. AnyEvent, on the other hand, is lean and up to the point, by only	100	follow. AnyEvent, on the other hand, is lean and to the point, by only
96	offering the functionality that is necessary, in as thin as a wrapper as	101	offering the functionality that is necessary, in as thin as a wrapper as
97	technically possible.	102	technically possible.
98		103
99	Of course, AnyEvent comes with a big (and fully optional!) toolbox	104	Of course, AnyEvent comes with a big (and fully optional!) toolbox
100	of useful functionality, such as an asynchronous DNS resolver, 100%	105	of useful functionality, such as an asynchronous DNS resolver, 100%
…		…
106	useful) and you want to force your users to use the one and only event	111	useful) and you want to force your users to use the one and only event
107	model, you should I<not> use this module.	112	model, you should I<not> use this module.
108		113
109	=head1 DESCRIPTION	114	=head1 DESCRIPTION
110		115
111	L<AnyEvent> provides an identical interface to multiple event loops. This	116	L<AnyEvent> provides a uniform interface to various event loops. This
112	allows module authors to utilise an event loop without forcing module	117	allows module authors to use event loop functionality without forcing
113	users to use the same event loop (as only a single event loop can coexist	118	module users to use a specific event loop implementation (since more
114	peacefully at any one time).	119	than one event loop cannot coexist peacefully).
115		120
116	The interface itself is vaguely similar, but not identical to the L<Event>	121	The interface itself is vaguely similar, but not identical to the L<Event>
117	module.	122	module.
118		123
119	During the first call of any watcher-creation method, the module tries	124	During the first call of any watcher-creation method, the module tries
120	to detect the currently loaded event loop by probing whether one of the	125	to detect the currently loaded event loop by probing whether one of the
121	following modules is already loaded: L<EV>,	126	following modules is already loaded: L<EV>, L<AnyEvent::Loop>,
122	L<Event>, L<Glib>, L<AnyEvent::Impl::Perl>, L<Tk>, L<Event::Lib>, L<Qt>,	127	L<Event>, L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>. The first one
123	L<POE>. The first one found is used. If none are found, the module tries	128	found is used. If none are detected, the module tries to load the first
124	to load these modules (excluding Tk, Event::Lib, Qt and POE as the pure perl	129	four modules in the order given; but note that if L<EV> is not
125	adaptor should always succeed) in the order given. The first one that can	130	available, the pure-perl L<AnyEvent::Loop> should always work, so
126	be successfully loaded will be used. If, after this, still none could be	131	the other two are not normally tried.
127	found, AnyEvent will fall back to a pure-perl event loop, which is not
128	very efficient, but should work everywhere.
129		132
130	Because AnyEvent first checks for modules that are already loaded, loading	133	Because AnyEvent first checks for modules that are already loaded, loading
131	an event model explicitly before first using AnyEvent will likely make	134	an event model explicitly before first using AnyEvent will likely make
132	that model the default. For example:	135	that model the default. For example:
133		136
…		…
135	use AnyEvent;	138	use AnyEvent;
136		139
137	# .. AnyEvent will likely default to Tk	140	# .. AnyEvent will likely default to Tk
138		141
139	The I<likely> means that, if any module loads another event model and	142	The I<likely> means that, if any module loads another event model and
140	starts using it, all bets are off. Maybe you should tell their authors to	143	starts using it, all bets are off - this case should be very rare though,
141	use AnyEvent so their modules work together with others seamlessly...	144	as very few modules hardcode event loops without announcing this very
		145	loudly.
142		146
143	The pure-perl implementation of AnyEvent is called	147	The pure-perl implementation of AnyEvent is called C<AnyEvent::Loop>. Like
144	C<AnyEvent::Impl::Perl>. Like other event modules you can load it	148	other event modules you can load it explicitly and enjoy the high
145	explicitly and enjoy the high availability of that event loop :)	149	availability of that event loop :)
146		150
147	=head1 WATCHERS	151	=head1 WATCHERS
148		152
149	AnyEvent has the central concept of a I<watcher>, which is an object that	153	AnyEvent has the central concept of a I<watcher>, which is an object that
150	stores relevant data for each kind of event you are waiting for, such as	154	stores relevant data for each kind of event you are waiting for, such as
…		…
155	callback when the event occurs (of course, only when the event model	159	callback when the event occurs (of course, only when the event model
156	is in control).	160	is in control).
157		161
158	Note that B<callbacks must not permanently change global variables>	162	Note that B<callbacks must not permanently change global variables>
159	potentially in use by the event loop (such as C<$_> or C<$[>) and that B<<	163	potentially in use by the event loop (such as C<$_> or C<$[>) and that B<<
160	callbacks must not C<die> >>. The former is good programming practise in	164	callbacks must not C<die> >>. The former is good programming practice in
161	Perl and the latter stems from the fact that exception handling differs	165	Perl and the latter stems from the fact that exception handling differs
162	widely between event loops.	166	widely between event loops.
163		167
164	To disable the watcher you have to destroy it (e.g. by setting the	168	To disable a watcher you have to destroy it (e.g. by setting the
165	variable you store it in to C<undef> or otherwise deleting all references	169	variable you store it in to C<undef> or otherwise deleting all references
166	to it).	170	to it).
167		171
168	All watchers are created by calling a method on the C<AnyEvent> class.	172	All watchers are created by calling a method on the C<AnyEvent> class.
169		173
170	Many watchers either are used with "recursion" (repeating timers for	174	Many watchers either are used with "recursion" (repeating timers for
171	example), or need to refer to their watcher object in other ways.	175	example), or need to refer to their watcher object in other ways.
172		176
173	An any way to achieve that is this pattern:	177	One way to achieve that is this pattern:
174		178
175	my $w; $w = AnyEvent->type (arg => value ..., cb => sub {	179	my $w; $w = AnyEvent->type (arg => value ..., cb => sub {
176	# you can use $w here, for example to undef it	180	# you can use $w here, for example to undef it
177	undef $w;	181	undef $w;
178	});	182	});
…		…
180	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,
181	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
182	declared.	186	declared.
183		187
184	=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	);
185		195
186	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
187	with the following mandatory key-value pairs as arguments:	197	with the following mandatory key-value pairs as arguments:
188		198
189	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
…		…
204		214
205	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.
206	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
207	underlying file descriptor.	217	underlying file descriptor.
208		218
209	Some event loops issue spurious readyness notifications, so you should	219	Some event loops issue spurious readiness notifications, so you should
210	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
211	handles.	221	handles.
212		222
213	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
214	watcher.	224	watcher.
…		…
219	undef $w;	229	undef $w;
220	});	230	});
221		231
222	=head2 TIME WATCHERS	232	=head2 TIME WATCHERS
223		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
224	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 >>
225	method with the following mandatory arguments:	243	method with the following mandatory arguments:
226		244
227	C<after> specifies after how many seconds (fractional values are	245	C<after> specifies after how many seconds (fractional values are
228	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
…		…
230		248
231	Although the callback might get passed parameters, their value and	249	Although the callback might get passed parameters, their value and
232	presence is undefined and you cannot rely on them. Portable AnyEvent	250	presence is undefined and you cannot rely on them. Portable AnyEvent
233	callbacks cannot use arguments passed to time watcher callbacks.	251	callbacks cannot use arguments passed to time watcher callbacks.
234		252
235	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
236	parameter, C<interval>, as a strictly positive number (> 0), then the	254	parameter, C<interval>, as a strictly positive number (> 0), then the
237	callback will be invoked regularly at that interval (in fractional	255	callback will be invoked regularly at that interval (in fractional
238	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
239	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.
240		258
241	The callback will be rescheduled before invoking the callback, but no	259	The callback will be rescheduled before invoking the callback, but no
242	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
243	only approximate.	261	only approximate.
244		262
245	Example: fire an event after 7.7 seconds.	263	Example: fire an event after 7.7 seconds.
246		264
247	my $w = AnyEvent->timer (after => 7.7, cb => sub {	265	my $w = AnyEvent->timer (after => 7.7, cb => sub {
…		…
265		283
266	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
267	use absolute time internally. This makes a difference when your clock	285	use absolute time internally. This makes a difference when your clock
268	"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
269	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
270	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.
271		289
272	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
273	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
274	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)
275	timers.	293	timers.
276		294
277	AnyEvent always prefers relative timers, if available, matching the	295	AnyEvent always prefers relative timers, if available, matching the
278	AnyEvent API.	296	AnyEvent API.
…		…
300	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
301	function to call when you want to know the current time.>	319	function to call when you want to know the current time.>
302		320
303	This function is also often faster then C<< AnyEvent->time >>, and	321	This function is also often faster then C<< AnyEvent->time >>, and
304	thus the preferred method if you want some timestamp (for example,	322	thus the preferred method if you want some timestamp (for example,
305	L<AnyEvent::Handle> uses this to update it's activity timeouts).	323	L<AnyEvent::Handle> uses this to update its activity timeouts).
306		324
307	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
308	with your timing, you can skip it without bad conscience.	326	with your timing; you can skip it without a bad conscience.
309		327
310	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>
311	and L<EV> and the following set-up:	329	and L<EV> and the following set-up:
312		330
313	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
314	time=500 (assume no other callbacks delay processing). In your callback,	332	time=500 (assume no other callbacks delay processing). In your callback,
315	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
316	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
317	after three seconds.	335	after three seconds.
318		336
…		…
338	difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into	356	difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into
339	account.	357	account.
340		358
341	=item AnyEvent->now_update	359	=item AnyEvent->now_update
342		360
343	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
344	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 >>,
345	AnyEvent->now >>, above).	363	above).
346		364
347	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
348	this "current" time will differ substantially from the real time, which	366	this "current" time will differ substantially from the real time, which
349	might affect timers and time-outs.	367	might affect timers and time-outs.
350		368
351	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
352	event loop's idea of "current time".	370	event loop's idea of "current time".
353		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
354	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.
355		380
356	=back	381	=back
357		382
358	=head2 SIGNAL WATCHERS	383	=head2 SIGNAL WATCHERS
		384
		385	$w = AnyEvent->signal (signal => <uppercase_signal_name>, cb => <callback>);
359		386
360	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
361	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
362	callback to be invoked whenever a signal occurs.	389	callback to be invoked whenever a signal occurs.
363		390
…		…
380		407
381	Example: exit on SIGINT	408	Example: exit on SIGINT
382		409
383	my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });	410	my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });
384		411
		412	=head3 Restart Behaviour
		413
		414	While restart behaviour is up to the event loop implementation, most will
		415	not restart syscalls (that includes L<Async::Interrupt> and AnyEvent's
		416	pure perl implementation).
		417
		418	=head3 Safe/Unsafe Signals
		419
		420	Perl signals can be either "safe" (synchronous to opcode handling) or
		421	"unsafe" (asynchronous) - the former might get delayed indefinitely, the
		422	latter might corrupt your memory.
		423
		424	AnyEvent signal handlers are, in addition, synchronous to the event loop,
		425	i.e. they will not interrupt your running perl program but will only be
		426	called as part of the normal event handling (just like timer, I/O etc.
		427	callbacks, too).
		428
385	=head3 Signal Races, Delays and Workarounds	429	=head3 Signal Races, Delays and Workarounds
386		430
387	Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support attaching	431	Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support attaching
388	callbacks to signals in a generic way, which is a pity, as you cannot do	432	callbacks to signals in a generic way, which is a pity, as you cannot
389	race-free signal handling in perl. AnyEvent will try to do it's best, but	433	do race-free signal handling in perl, requiring C libraries for
		434	this. AnyEvent will try to do its best, which means in some cases,
390	in some cases, signals will be delayed. The maximum time a signal might	435	signals will be delayed. The maximum time a signal might be delayed is
391	be delayed is specified in C<$AnyEvent::MAX_SIGNAL_LATENCY> (default: 10	436	specified in C<$AnyEvent::MAX_SIGNAL_LATENCY> (default: 10 seconds). This
392	seconds). This variable can be changed only before the first signal	437	variable can be changed only before the first signal watcher is created,
393	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
394	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
395	saving. All these problems can be avoided by installing the optional	443	All these problems can be avoided by installing the optional
396	L<Async::Interrupt> module. This will not work with inherently broken	444	L<Async::Interrupt> module, which works with most event loops. It will not
397	event loops such as L<Event> or L<Event::Lib> (and not with L<POE>	445	work with inherently broken event loops such as L<Event> or L<Event::Lib>
398	currently, as POE does it's own workaround with one-second latency). With	446	(and not with L<POE> currently, as POE does its own workaround with
399	those, you just have to suffer the delays.	447	one-second latency). For those, you just have to suffer the delays.
400		448
401	=head2 CHILD PROCESS WATCHERS	449	=head2 CHILD PROCESS WATCHERS
402		450
		451	$w = AnyEvent->child (pid => <process id>, cb => <callback>);
		452
403	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.
404		454
405	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,
406	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
407	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
408	any trace events (stopped/continued).	458	finished and an exit status is available, not on any trace events
		459	(stopped/continued).
409		460
410	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
411	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
412	callback arguments.	463	callback arguments.
413		464
…		…
431	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
432	watcher before you C<fork> the child (alternatively, you can call	483	watcher before you C<fork> the child (alternatively, you can call
433	C<AnyEvent::detect>).	484	C<AnyEvent::detect>).
434		485
435	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
436	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
437	mentioned in the description of signal watchers apply.	488	problems mentioned in the description of signal watchers apply.
438		489
439	Example: fork a process and wait for it	490	Example: fork a process and wait for it
440		491
441	my $done = AnyEvent->condvar;	492	my $done = AnyEvent->condvar;
442		493
…		…
454	# do something else, then wait for process exit	505	# do something else, then wait for process exit
455	$done->recv;	506	$done->recv;
456		507
457	=head2 IDLE WATCHERS	508	=head2 IDLE WATCHERS
458		509
459	Sometimes there is a need to do something, but it is not so important	510	$w = AnyEvent->idle (cb => <callback>);
460	to do it instantly, but only when there is nothing better to do. This
461	"nothing better to do" is usually defined to be "no other events need
462	attention by the event loop".
463		511
464	Idle watchers ideally get invoked when the event loop has nothing	512	This will repeatedly invoke the callback after the process becomes idle,
465	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.
466	events. Instead of blocking, the idle watcher is invoked.
467		514
468	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
469	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
470	will simply call the callback "from time to time".	526	will simply call the callback "from time to time".
471		527
472	Example: read lines from STDIN, but only process them when the	528	Example: read lines from STDIN, but only process them when the
473	program is otherwise idle:	529	program is otherwise idle:
…		…
489	});	545	});
490	});	546	});
491		547
492	=head2 CONDITION VARIABLES	548	=head2 CONDITION VARIABLES
493		549
		550	$cv = AnyEvent->condvar;
		551
		552	$cv->send (<list>);
		553	my @res = $cv->recv;
		554
494	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
495	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
496	will actively watch for new events and call your callbacks.	557	will actively watch for new events and call your callbacks.
497		558
498	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
499	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).
500		561
501	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
502	because they represent a condition that must become true.	563	they represent a condition that must become true.
503		564
504	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.
505		566
506	Condition variables can be created by calling the C<< AnyEvent->condvar	567	Condition variables can be created by calling the C<< AnyEvent->condvar
507	>> method, usually without arguments. The only argument pair allowed is	568	>> method, usually without arguments. The only argument pair allowed is
…		…
512	After creation, the condition variable is "false" until it becomes "true"	573	After creation, the condition variable is "false" until it becomes "true"
513	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
514	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<<
515	->send >> method).	576	->send >> method).
516		577
517	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
518	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:
519	in time where multiple outstanding events have been processed. And yet	580
520	another way to call them is transactions - each condition variable can be	581	=over 4
521	used to represent a transaction, which finishes at some point and delivers	582
522	a result. And yet some people know them as "futures" - a promise to	583	=item * Condition variables are like callbacks - you can call them (and pass them instead
523	compute/deliver something that you can wait for.	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
524		601
525	Condition variables are very useful to signal that something has finished,	602	Condition variables are very useful to signal that something has finished,
526	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,
527	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
528	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
…		…
541		618
542	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
543	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
544	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
545	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
546	it's C<new> method in your own C<new> method.	623	its C<new> method in your own C<new> method.
547		624
548	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
549	eventually calls C<< -> send >>, and the "consumer side", which waits	626	eventually calls C<< -> send >>, and the "consumer side", which waits
550	for the send to occur.	627	for the send to occur.
551		628
552	Example: wait for a timer.	629	Example: wait for a timer.
553		630
554	# wait till the result is ready	631	# condition: "wait till the timer is fired"
555	my $result_ready = AnyEvent->condvar;	632	my $timer_fired = AnyEvent->condvar;
556		633
557	# do something such as adding a timer	634	# create the timer - we could wait for, say
558	# or socket watcher the calls $result_ready->send	635	# a handle becomign ready, or even an
559	# when the "result" is ready.	636	# AnyEvent::HTTP request to finish, but
560	# in this case, we simply use a timer:	637	# in this case, we simply use a timer:
561	my $w = AnyEvent->timer (	638	my $w = AnyEvent->timer (
562	after => 1,	639	after => 1,
563	cb => sub { $result_ready->send },	640	cb => sub { $timer_fired->send },
564	);	641	);
565		642
566	# this "blocks" (while handling events) till the callback	643	# this "blocks" (while handling events) till the callback
567	# calls -<send	644	# calls ->send
568	$result_ready->recv;	645	$timer_fired->recv;
569		646
570	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
571	variables are also callable directly.	648	variables are also callable directly.
572		649
573	my $done = AnyEvent->condvar;	650	my $done = AnyEvent->condvar;
…		…
616	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
617	C<send>.	694	C<send>.
618		695
619	=item $cv->croak ($error)	696	=item $cv->croak ($error)
620		697
621	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
622	C<Carp::croak> with the given error message/object/scalar.	699	C<Carp::croak> with the given error message/object/scalar.
623		700
624	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
625	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
626	delays the error detetcion, but has the overwhelmign advantage that it	703	delays the error detection, but has the overwhelming advantage that it
627	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
628	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
629	the problem.	706	the problem.
630		707
631	=item $cv->begin ([group callback])	708	=item $cv->begin ([group callback])
632		709
633	=item $cv->end	710	=item $cv->end
…		…
636	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
637	to use a condition variable for the whole process.	714	to use a condition variable for the whole process.
638		715
639	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
640	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
641	>>, 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
642	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
643	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.
644		722
645	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
646	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
647	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).
648		726
…		…
670	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
671	sending.	749	sending.
672		750
673	The ping example mentioned above is slightly more complicated, as the	751	The ping example mentioned above is slightly more complicated, as the
674	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
675	begung can potentially be zero:	753	begun can potentially be zero:
676		754
677	my $cv = AnyEvent->condvar;	755	my $cv = AnyEvent->condvar;
678		756
679	my %result;	757	my %result;
680	$cv->begin (sub { $cv->send (\%result) });	758	$cv->begin (sub { shift->send (\%result) });
681		759
682	for my $host (@list_of_hosts) {	760	for my $host (@list_of_hosts) {
683	$cv->begin;	761	$cv->begin;
684	ping_host_then_call_callback $host, sub {	762	ping_host_then_call_callback $host, sub {
685	$result{$host} = ...;	763	$result{$host} = ...;
…		…
701	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
702	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
703	doesn't execute once).	781	doesn't execute once).
704		782
705	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
706	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
707	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
708	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,
709	call C<end>.	787	call C<end>.
710		788
711	=back	789	=back
…		…
718	=over 4	796	=over 4
719		797
720	=item $cv->recv	798	=item $cv->recv
721		799
722	Wait (blocking if necessary) until the C<< ->send >> or C<< ->croak	800	Wait (blocking if necessary) until the C<< ->send >> or C<< ->croak
723	>> methods have been called on c<$cv>, while servicing other watchers	801	>> methods have been called on C<$cv>, while servicing other watchers
724	normally.	802	normally.
725		803
726	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
727	will return immediately.	805	will return immediately.
728		806
…		…
745	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
746	condition variables with some kind of request results and supporting	824	condition variables with some kind of request results and supporting
747	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,
748	while still supporting blocking waits if the caller so desires).	826	while still supporting blocking waits if the caller so desires).
749		827
750	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
751	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
752	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
753	waits otherwise.	831	waits otherwise.
754		832
755	=item $bool = $cv->ready	833	=item $bool = $cv->ready
…		…
761		839
762	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
763	replaces it before doing so.	841	replaces it before doing so.
764		842
765	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
766	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
767	variable itself. Calling C<recv> inside the callback or at any later time	845	condition variable itself. If the condition is already true, the
768	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.
769		848
770	=back	849	=back
771		850
772	=head1 SUPPORTED EVENT LOOPS/BACKENDS	851	=head1 SUPPORTED EVENT LOOPS/BACKENDS
773		852
…		…
776	=over 4	855	=over 4
777		856
778	=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.
779		858
780	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
781	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
782	that, will fall back to its own pure-perl implementation, which is	861	pure-perl implementation, which is available everywhere as it comes with
783	available everywhere as it comes with AnyEvent itself.	862	AnyEvent itself.
784		863
785	AnyEvent::Impl::EV based on EV (interface to libev, best choice).	864	AnyEvent::Impl::EV based on EV (interface to libev, best choice).
786	AnyEvent::Impl::Event based on Event, very stable, few glitches.
787	AnyEvent::Impl::Perl pure-perl implementation, fast and portable.	865	AnyEvent::Impl::Perl pure-perl AnyEvent::Loop, fast and portable.
788		866
789	=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.
790		868
791	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
792	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
793	them. This means that AnyEvent will automatically pick the right backend	871	them. This means that AnyEvent will automatically pick the right backend
794	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
795	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.
796		874
		875	AnyEvent::Impl::Event based on Event, very stable, few glitches.
797	AnyEvent::Impl::Glib based on Glib, slow but very stable.	876	AnyEvent::Impl::Glib based on Glib, slow but very stable.
798	AnyEvent::Impl::Tk based on Tk, very broken.	877	AnyEvent::Impl::Tk based on Tk, very broken.
799	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.	878	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
800	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.
801		884
802	=item Backends with special needs.	885	=item Backends with special needs.
803		886
804	Qt requires the Qt::Application to be instantiated first, but will	887	Qt requires the Qt::Application to be instantiated first, but will
805	otherwise be picked up automatically. As long as the main program	888	otherwise be picked up automatically. As long as the main program
806	instantiates the application before any AnyEvent watchers are created,	889	instantiates the application before any AnyEvent watchers are created,
807	everything should just work.	890	everything should just work.
808		891
809	AnyEvent::Impl::Qt based on Qt.	892	AnyEvent::Impl::Qt based on Qt.
810		893
811	Support for IO::Async can only be partial, as it is too broken and
812	architecturally limited to even support the AnyEvent API. It also
813	is the only event loop that needs the loop to be set explicitly, so
814	it can only be used by a main program knowing about AnyEvent. See
815	L<AnyEvent::Impl::Async> for the gory details.
816
817	AnyEvent::Impl::IOAsync based on IO::Async, cannot be autoprobed.
818
819	=item Event loops that are indirectly supported via other backends.	894	=item Event loops that are indirectly supported via other backends.
820		895
821	Some event loops can be supported via other modules:	896	Some event loops can be supported via other modules:
822		897
823	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>.
…		…
848	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
849	backend has been autodetected.	924	backend has been autodetected.
850		925
851	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
852	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
853	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
854	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
855	will be C<urxvt::anyevent>).	930	will be C<urxvt::anyevent>).
856		931
857	=item AnyEvent::detect	932	=item AnyEvent::detect
858		933
859	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model	934	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model
860	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
861	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
862	runtime, and not e.g. while initialising of your module.	937	runtime, and not e.g. during initialisation of your module.
863		938
864	If you need to do some initialisation before AnyEvent watchers are	939	If you need to do some initialisation before AnyEvent watchers are
865	created, use C<post_detect>.	940	created, use C<post_detect>.
866		941
867	=item $guard = AnyEvent::post_detect { BLOCK }	942	=item $guard = AnyEvent::post_detect { BLOCK }
868		943
869	Arranges for the code block to be executed as soon as the event model is	944	Arranges for the code block to be executed as soon as the event model is
870	autodetected (or immediately if this has already happened).	945	autodetected (or immediately if that has already happened).
871		946
872	The block will be executed I<after> the actual backend has been detected	947	The block will be executed I<after> the actual backend has been detected
873	(C<$AnyEvent::MODEL> is set), but I<before> any watchers have been	948	(C<$AnyEvent::MODEL> is set), but I<before> any watchers have been
874	created, so it is possible to e.g. patch C<@AnyEvent::ISA> or do	949	created, so it is possible to e.g. patch C<@AnyEvent::ISA> or do
875	other initialisations - see the sources of L<AnyEvent::Strict> or	950	other initialisations - see the sources of L<AnyEvent::Strict> or
…		…
879	event module detection too early, for example, L<AnyEvent::AIO> creates	954	event module detection too early, for example, L<AnyEvent::AIO> creates
880	and installs the global L<IO::AIO> watcher in a C<post_detect> block to	955	and installs the global L<IO::AIO> watcher in a C<post_detect> block to
881	avoid autodetecting the event module at load time.	956	avoid autodetecting the event module at load time.
882		957
883	If called in scalar or list context, then it creates and returns an object	958	If called in scalar or list context, then it creates and returns an object
884	that automatically removes the callback again when it is destroyed. See	959	that automatically removes the callback again when it is destroyed (or
		960	C<undef> when the hook was immediately executed). See L<AnyEvent::AIO> for
885	L<Coro::BDB> for a case where this is useful.	961	a case where this is useful.
		962
		963	Example: Create a watcher for the IO::AIO module and store it in
		964	C<$WATCHER>, but do so only do so after the event loop is initialised.
		965
		966	our WATCHER;
		967
		968	my $guard = AnyEvent::post_detect {
		969	$WATCHER = AnyEvent->io (fh => IO::AIO::poll_fileno, poll => 'r', cb => \&IO::AIO::poll_cb);
		970	};
		971
		972	# the ||= is important in case post_detect immediately runs the block,
		973	# as to not clobber the newly-created watcher. assigning both watcher and
		974	# post_detect guard to the same variable has the advantage of users being
		975	# able to just C<undef $WATCHER> if the watcher causes them grief.
		976
		977	$WATCHER ||= $guard;
886		978
887	=item @AnyEvent::post_detect	979	=item @AnyEvent::post_detect
888		980
889	If there are any code references in this array (you can C<push> to it	981	If there are any code references in this array (you can C<push> to it
890	before or after loading AnyEvent), then they will called directly after	982	before or after loading AnyEvent), then they will be called directly
891	the event loop has been chosen.	983	after the event loop has been chosen.
892		984
893	You should check C<$AnyEvent::MODEL> before adding to this array, though:	985	You should check C<$AnyEvent::MODEL> before adding to this array, though:
894	if it is defined then the event loop has already been detected, and the	986	if it is defined then the event loop has already been detected, and the
895	array will be ignored.	987	array will be ignored.
896		988
897	Best use C<AnyEvent::post_detect { BLOCK }> when your application allows	989	Best use C<AnyEvent::post_detect { BLOCK }> when your application allows
898	it,as it takes care of these details.	990	it, as it takes care of these details.
899		991
900	This variable is mainly useful for modules that can do something useful	992	This variable is mainly useful for modules that can do something useful
901	when AnyEvent is used and thus want to know when it is initialised, but do	993	when AnyEvent is used and thus want to know when it is initialised, but do
902	not need to even load it by default. This array provides the means to hook	994	not need to even load it by default. This array provides the means to hook
903	into AnyEvent passively, without loading it.	995	into AnyEvent passively, without loading it.
904		996
		997	Example: To load Coro::AnyEvent whenever Coro and AnyEvent are used
		998	together, you could put this into Coro (this is the actual code used by
		999	Coro to accomplish this):
		1000
		1001	if (defined $AnyEvent::MODEL) {
		1002	# AnyEvent already initialised, so load Coro::AnyEvent
		1003	require Coro::AnyEvent;
		1004	} else {
		1005	# AnyEvent not yet initialised, so make sure to load Coro::AnyEvent
		1006	# as soon as it is
		1007	push @AnyEvent::post_detect, sub { require Coro::AnyEvent };
		1008	}
		1009
905	=back	1010	=back
906		1011
907	=head1 WHAT TO DO IN A MODULE	1012	=head1 WHAT TO DO IN A MODULE
908		1013
909	As a module author, you should C<use AnyEvent> and call AnyEvent methods	1014	As a module author, you should C<use AnyEvent> and call AnyEvent methods
…		…
919	because it will stall the whole program, and the whole point of using	1024	because it will stall the whole program, and the whole point of using
920	events is to stay interactive.	1025	events is to stay interactive.
921		1026
922	It is fine, however, to call C<< ->recv >> when the user of your module	1027	It is fine, however, to call C<< ->recv >> when the user of your module
923	requests it (i.e. if you create a http request object ad have a method	1028	requests it (i.e. if you create a http request object ad have a method
924	called C<results> that returns the results, it should call C<< ->recv >>	1029	called C<results> that returns the results, it may call C<< ->recv >>
925	freely, as the user of your module knows what she is doing. always).	1030	freely, as the user of your module knows what she is doing. Always).
926		1031
927	=head1 WHAT TO DO IN THE MAIN PROGRAM	1032	=head1 WHAT TO DO IN THE MAIN PROGRAM
928		1033
929	There will always be a single main program - the only place that should	1034	There will always be a single main program - the only place that should
930	dictate which event model to use.	1035	dictate which event model to use.
931		1036
932	If it doesn't care, it can just "use AnyEvent" and use it itself, or not	1037	If the program is not event-based, it need not do anything special, even
933	do anything special (it does not need to be event-based) and let AnyEvent	1038	when it depends on a module that uses an AnyEvent. If the program itself
934	decide which implementation to chose if some module relies on it.	1039	uses AnyEvent, but does not care which event loop is used, all it needs
		1040	to do is C<use AnyEvent>. In either case, AnyEvent will choose the best
		1041	available loop implementation.
935		1042
936	If the main program relies on a specific event model - for example, in	1043	If the main program relies on a specific event model - for example, in
937	Gtk2 programs you have to rely on the Glib module - you should load the	1044	Gtk2 programs you have to rely on the Glib module - you should load the
938	event module before loading AnyEvent or any module that uses it: generally	1045	event module before loading AnyEvent or any module that uses it: generally
939	speaking, you should load it as early as possible. The reason is that	1046	speaking, you should load it as early as possible. The reason is that
940	modules might create watchers when they are loaded, and AnyEvent will	1047	modules might create watchers when they are loaded, and AnyEvent will
941	decide on the event model to use as soon as it creates watchers, and it	1048	decide on the event model to use as soon as it creates watchers, and it
942	might chose the wrong one unless you load the correct one yourself.	1049	might choose the wrong one unless you load the correct one yourself.
943		1050
944	You can chose to use a pure-perl implementation by loading the	1051	You can chose to use a pure-perl implementation by loading the
945	C<AnyEvent::Impl::Perl> module, which gives you similar behaviour	1052	C<AnyEvent::Loop> module, which gives you similar behaviour
946	everywhere, but letting AnyEvent chose the model is generally better.	1053	everywhere, but letting AnyEvent chose the model is generally better.
947		1054
948	=head2 MAINLOOP EMULATION	1055	=head2 MAINLOOP EMULATION
949		1056
950	Sometimes (often for short test scripts, or even standalone programs who	1057	Sometimes (often for short test scripts, or even standalone programs who
…		…
965	=head1 OTHER MODULES	1072	=head1 OTHER MODULES
966		1073
967	The following is a non-exhaustive list of additional modules that use	1074	The following is a non-exhaustive list of additional modules that use
968	AnyEvent as a client and can therefore be mixed easily with other AnyEvent	1075	AnyEvent as a client and can therefore be mixed easily with other AnyEvent
969	modules and other event loops in the same program. Some of the modules	1076	modules and other event loops in the same program. Some of the modules
970	come with AnyEvent, most are available via CPAN.	1077	come as part of AnyEvent, the others are available via CPAN.
971		1078
972	=over 4	1079	=over 4
973		1080
974	=item L<AnyEvent::Util>	1081	=item L<AnyEvent::Util>
975		1082
976	Contains various utility functions that replace often-used but blocking	1083	Contains various utility functions that replace often-used blocking
977	functions such as C<inet_aton> by event-/callback-based versions.	1084	functions such as C<inet_aton> with event/callback-based versions.
978		1085
979	=item L<AnyEvent::Socket>	1086	=item L<AnyEvent::Socket>
980		1087
981	Provides various utility functions for (internet protocol) sockets,	1088	Provides various utility functions for (internet protocol) sockets,
982	addresses and name resolution. Also functions to create non-blocking tcp	1089	addresses and name resolution. Also functions to create non-blocking tcp
…		…
984		1091
985	=item L<AnyEvent::Handle>	1092	=item L<AnyEvent::Handle>
986		1093
987	Provide read and write buffers, manages watchers for reads and writes,	1094	Provide read and write buffers, manages watchers for reads and writes,
988	supports raw and formatted I/O, I/O queued and fully transparent and	1095	supports raw and formatted I/O, I/O queued and fully transparent and
989	non-blocking SSL/TLS (via L<AnyEvent::TLS>.	1096	non-blocking SSL/TLS (via L<AnyEvent::TLS>).
990		1097
991	=item L<AnyEvent::DNS>	1098	=item L<AnyEvent::DNS>
992		1099
993	Provides rich asynchronous DNS resolver capabilities.	1100	Provides rich asynchronous DNS resolver capabilities.
994		1101
		1102	=item L<AnyEvent::HTTP>, L<AnyEvent::IRC>, L<AnyEvent::XMPP>, L<AnyEvent::GPSD>, L<AnyEvent::IGS>, L<AnyEvent::FCP>
		1103
		1104	Implement event-based interfaces to the protocols of the same name (for
		1105	the curious, IGS is the International Go Server and FCP is the Freenet
		1106	Client Protocol).
		1107
		1108	=item L<AnyEvent::Handle::UDP>
		1109
		1110	Here be danger!
		1111
		1112	As Pauli would put it, "Not only is it not right, it's not even wrong!" -
		1113	there are so many things wrong with AnyEvent::Handle::UDP, most notably
		1114	its use of a stream-based API with a protocol that isn't streamable, that
		1115	the only way to improve it is to delete it.
		1116
		1117	It features data corruption (but typically only under load) and general
		1118	confusion. On top, the author is not only clueless about UDP but also
		1119	fact-resistant - some gems of his understanding: "connect doesn't work
		1120	with UDP", "UDP packets are not IP packets", "UDP only has datagrams, not
		1121	packets", "I don't need to implement proper error checking as UDP doesn't
		1122	support error checking" and so on - he doesn't even understand what's
		1123	wrong with his module when it is explained to him.
		1124
995	=item L<AnyEvent::HTTP>	1125	=item L<AnyEvent::DBI>
996		1126
997	A simple-to-use HTTP library that is capable of making a lot of concurrent	1127	Executes L<DBI> requests asynchronously in a proxy process for you,
998	HTTP requests.	1128	notifying you in an event-based way when the operation is finished.
		1129
		1130	=item L<AnyEvent::AIO>
		1131
		1132	Truly asynchronous (as opposed to non-blocking) I/O, should be in the
		1133	toolbox of every event programmer. AnyEvent::AIO transparently fuses
		1134	L<IO::AIO> and AnyEvent together, giving AnyEvent access to event-based
		1135	file I/O, and much more.
999		1136
1000	=item L<AnyEvent::HTTPD>	1137	=item L<AnyEvent::HTTPD>
1001		1138
1002	Provides a simple web application server framework.	1139	A simple embedded webserver.
1003		1140
1004	=item L<AnyEvent::FastPing>	1141	=item L<AnyEvent::FastPing>
1005		1142
1006	The fastest ping in the west.	1143	The fastest ping in the west.
1007
1008	=item L<AnyEvent::DBI>
1009
1010	Executes L<DBI> requests asynchronously in a proxy process.
1011
1012	=item L<AnyEvent::AIO>
1013
1014	Truly asynchronous I/O, should be in the toolbox of every event
1015	programmer. AnyEvent::AIO transparently fuses L<IO::AIO> and AnyEvent
1016	together.
1017
1018	=item L<AnyEvent::BDB>
1019
1020	Truly asynchronous Berkeley DB access. AnyEvent::BDB transparently fuses
1021	L<BDB> and AnyEvent together.
1022
1023	=item L<AnyEvent::GPSD>
1024
1025	A non-blocking interface to gpsd, a daemon delivering GPS information.
1026
1027	=item L<AnyEvent::IRC>
1028
1029	AnyEvent based IRC client module family (replacing the older Net::IRC3).
1030
1031	=item L<AnyEvent::XMPP>
1032
1033	AnyEvent based XMPP (Jabber protocol) module family (replacing the older
1034	Net::XMPP2>.
1035
1036	=item L<AnyEvent::IGS>
1037
1038	A non-blocking interface to the Internet Go Server protocol (used by
1039	L<App::IGS>).
1040
1041	=item L<Net::FCP>
1042
1043	AnyEvent-based implementation of the Freenet Client Protocol, birthplace
1044	of AnyEvent.
1045
1046	=item L<Event::ExecFlow>
1047
1048	High level API for event-based execution flow control.
1049		1144
1050	=item L<Coro>	1145	=item L<Coro>
1051		1146
1052	Has special support for AnyEvent via L<Coro::AnyEvent>.	1147	Has special support for AnyEvent via L<Coro::AnyEvent>.
1053		1148
…		…
1057		1152
1058	package AnyEvent;	1153	package AnyEvent;
1059		1154
1060	# basically a tuned-down version of common::sense	1155	# basically a tuned-down version of common::sense
1061	sub common_sense {	1156	sub common_sense {
1062	# no warnings	1157	# from common:.sense 3.4
1063	${^WARNING_BITS} ^= ${^WARNING_BITS};	1158	${^WARNING_BITS} ^= ${^WARNING_BITS} ^ "\x3c\x3f\x33\x00\x0f\xf0\x0f\xc0\xf0\xfc\x33\x00";
1064	# use strict vars subs	1159	# use strict vars subs - NO UTF-8, as Util.pm doesn't like this atm. (uts46data.pl)
1065	$^H |= 0x00000600;	1160	$^H |= 0x00000600;
1066	}	1161	}
1067		1162
1068	BEGIN { AnyEvent::common_sense }	1163	BEGIN { AnyEvent::common_sense }
1069		1164
1070	use Carp ();	1165	use Carp ();
1071		1166
1072	our $VERSION = 4.85;	1167	our $VERSION = '5.34';
1073	our $MODEL;	1168	our $MODEL;
1074		1169
1075	our $AUTOLOAD;	1170	our $AUTOLOAD;
1076	our @ISA;	1171	our @ISA;
1077		1172
1078	our @REGISTRY;	1173	our @REGISTRY;
1079		1174
1080	our $WIN32;
1081
1082	our $VERBOSE;	1175	our $VERBOSE;
1083		1176
1084	BEGIN {	1177	BEGIN {
1085	eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }";	1178	require "AnyEvent/constants.pl";
		1179
1086	eval "sub TAINT(){ " . (${^TAINT}*1) . " }";	1180	eval "sub TAINT (){" . (${^TAINT}*1) . "}";
1087		1181
1088	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}	1182	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}
1089	if ${^TAINT};	1183	if ${^TAINT};
1090		1184
1091	$VERBOSE = $ENV{PERL_ANYEVENT_VERBOSE}*1;	1185	$VERBOSE = $ENV{PERL_ANYEVENT_VERBOSE}*1;
…		…
1102	for reverse split /\s*,\s*/,	1196	for reverse split /\s*,\s*/,
1103	$ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";	1197	$ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";
1104	}	1198	}
1105		1199
1106	my @models = (	1200	my @models = (
1107	[EV:: => AnyEvent::Impl::EV::],	1201	[EV:: => AnyEvent::Impl::EV:: , 1],
1108	[Event:: => AnyEvent::Impl::Event::],	1202	[AnyEvent::Loop:: => AnyEvent::Impl::Perl:: , 1],
1109	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::],
1110	# everything below here will not be autoprobed	1203	# everything below here will not (normally) be autoprobed
1111	# as the pureperl backend should work everywhere	1204	# as the pure perl backend should work everywhere
1112	# and is usually faster	1205	# and is usually faster
		1206	[Event:: => AnyEvent::Impl::Event::, 1],
1113	[Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers	1207	[Glib:: => AnyEvent::Impl::Glib:: , 1], # becomes extremely slow with many watchers
1114	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy	1208	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
		1209	[Irssi:: => AnyEvent::Impl::Irssi::], # Irssi has a bogus "Event" package
1115	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles	1210	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
1116	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program	1211	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program
1117	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza	1212	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
1118	[Wx:: => AnyEvent::Impl::POE::],	1213	[Wx:: => AnyEvent::Impl::POE::],
1119	[Prima:: => AnyEvent::Impl::POE::],	1214	[Prima:: => AnyEvent::Impl::POE::],
1120	# IO::Async is just too broken - we would need workarounds for its
1121	# byzantine signal and broken child handling, among others.
1122	# IO::Async is rather hard to detect, as it doesn't have any
1123	# obvious default class.
1124	# [IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program
1125	# [IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program	1215	[IO::Async::Loop:: => AnyEvent::Impl::IOAsync::],
1126	# [IO::Async::Notifier:: => AnyEvent::Impl::IOAsync::], # requires special main program	1216	[Cocoa::EventLoop:: => AnyEvent::Impl::Cocoa::],
		1217	[FLTK:: => AnyEvent::Impl::FLTK::],
1127	);	1218	);
1128		1219
1129	our %method = map +($_ => 1),	1220	our %method = map +($_ => 1),
1130	qw(io timer time now now_update signal child idle condvar one_event DESTROY);	1221	qw(io timer time now now_update signal child idle condvar DESTROY);
1131		1222
1132	our @post_detect;	1223	our @post_detect;
1133		1224
1134	sub post_detect(&) {	1225	sub post_detect(&) {
1135	my ($cb) = @_;	1226	my ($cb) = @_;
1136		1227
1137	if ($MODEL) {
1138	$cb->();
1139
1140	1
1141	} else {
1142	push @post_detect, $cb;	1228	push @post_detect, $cb;
1143		1229
1144	defined wantarray	1230	defined wantarray
1145	? bless \$cb, "AnyEvent::Util::postdetect"	1231	? bless \$cb, "AnyEvent::Util::postdetect"
1146	: ()	1232	: ()
1147	}
1148	}	1233	}
1149		1234
1150	sub AnyEvent::Util::postdetect::DESTROY {	1235	sub AnyEvent::Util::postdetect::DESTROY {
1151	@post_detect = grep $_ != ${$_[0]}, @post_detect;	1236	@post_detect = grep $_ != ${$_[0]}, @post_detect;
1152	}	1237	}
1153		1238
1154	sub detect() {	1239	sub detect() {
		1240	# free some memory
		1241	*detect = sub () { $MODEL };
		1242
		1243	local $!; # for good measure
		1244	local $SIG{__DIE__};
		1245
		1246	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {
		1247	my $model = "AnyEvent::Impl::$1";
		1248	if (eval "require $model") {
		1249	$MODEL = $model;
		1250	warn "AnyEvent: loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.\n" if $VERBOSE >= 2;
		1251	} else {
		1252	warn "AnyEvent: unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@" if $VERBOSE;
		1253	}
		1254	}
		1255
		1256	# check for already loaded models
1155	unless ($MODEL) {	1257	unless ($MODEL) {
1156	local $SIG{__DIE__};	1258	for (@REGISTRY, @models) {
1157		1259	my ($package, $model) = @$_;
1158	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {	1260	if (${"$package\::VERSION"} > 0) {
1159	my $model = "AnyEvent::Impl::$1";
1160	if (eval "require $model") {	1261	if (eval "require $model") {
1161	$MODEL = $model;	1262	$MODEL = $model;
1162	warn "AnyEvent: loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.\n" if $VERBOSE >= 2;	1263	warn "AnyEvent: autodetected model '$model', using it.\n" if $VERBOSE >= 2;
1163	} else {	1264	last;
1164	warn "AnyEvent: unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@" if $VERBOSE;	1265	}
1165	}	1266	}
1166	}	1267	}
1167		1268
1168	# check for already loaded models
1169	unless ($MODEL) {	1269	unless ($MODEL) {
		1270	# try to autoload a model
1170	for (@REGISTRY, @models) {	1271	for (@REGISTRY, @models) {
1171	my ($package, $model) = @$_;	1272	my ($package, $model, $autoload) = @$_;
		1273	if (
		1274	$autoload
		1275	and eval "require $package"
1172	if (${"$package\::VERSION"} > 0) {	1276	and ${"$package\::VERSION"} > 0
1173	if (eval "require $model") {	1277	and eval "require $model"
		1278	) {
1174	$MODEL = $model;	1279	$MODEL = $model;
1175	warn "AnyEvent: autodetected model '$model', using it.\n" if $VERBOSE >= 2;	1280	warn "AnyEvent: autoloaded model '$model', using it.\n" if $VERBOSE >= 2;
1176	last;	1281	last;
1177	}
1178	}	1282	}
1179	}	1283	}
1180		1284
1181	unless ($MODEL) {
1182	# try to load a model
1183
1184	for (@REGISTRY, @models) {
1185	my ($package, $model) = @$_;
1186	if (eval "require $package"
1187	and ${"$package\::VERSION"} > 0
1188	and eval "require $model") {
1189	$MODEL = $model;
1190	warn "AnyEvent: autoprobed model '$model', using it.\n" if $VERBOSE >= 2;
1191	last;
1192	}
1193	}
1194
1195	$MODEL	1285	$MODEL
1196	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.\n";	1286	or die "AnyEvent: backend autodetection failed - did you properly install AnyEvent?\n";
1197	}
1198	}	1287	}
1199
1200	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
1201
1202	unshift @ISA, $MODEL;
1203
1204	require AnyEvent::Strict if $ENV{PERL_ANYEVENT_STRICT};
1205
1206	(shift @post_detect)->() while @post_detect;
1207	}	1288	}
		1289
		1290	@models = (); # free probe data
		1291
		1292	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
		1293	unshift @ISA, $MODEL;
		1294
		1295	# now nuke some methods that are overridden by the backend.
		1296	# SUPER is not allowed.
		1297	for (qw(time signal child idle)) {
		1298	undef &{"AnyEvent::Base::$_"}
		1299	if defined &{"$MODEL\::$_"};
		1300	}
		1301
		1302	if ($ENV{PERL_ANYEVENT_STRICT}) {
		1303	eval { require AnyEvent::Strict };
		1304	warn "AnyEvent: cannot load AnyEvent::Strict: $@"
		1305	if $@ && $VERBOSE;
		1306	}
		1307
		1308	(shift @post_detect)->() while @post_detect;
		1309
		1310	*post_detect = sub(&) {
		1311	shift->();
		1312
		1313	undef
		1314	};
1208		1315
1209	$MODEL	1316	$MODEL
1210	}	1317	}
1211		1318
1212	sub AUTOLOAD {	1319	sub AUTOLOAD {
1213	(my $func = $AUTOLOAD) =~ s/.*://;	1320	(my $func = $AUTOLOAD) =~ s/.*://;
1214		1321
1215	$method{$func}	1322	$method{$func}
1216	or Carp::croak "$func: not a valid method for AnyEvent objects";	1323	or Carp::croak "$func: not a valid AnyEvent class method";
1217		1324
1218	detect unless $MODEL;	1325	detect;
1219		1326
1220	my $class = shift;	1327	my $class = shift;
1221	$class->$func (@_);	1328	$class->$func (@_);
1222	}	1329	}
1223		1330
…		…
1236	# we assume CLOEXEC is already set by perl in all important cases	1343	# we assume CLOEXEC is already set by perl in all important cases
1237		1344
1238	($fh2, $rw)	1345	($fh2, $rw)
1239	}	1346	}
1240		1347
		1348	=head1 SIMPLIFIED AE API
		1349
		1350	Starting with version 5.0, AnyEvent officially supports a second, much
		1351	simpler, API that is designed to reduce the calling, typing and memory
		1352	overhead by using function call syntax and a fixed number of parameters.
		1353
		1354	See the L<AE> manpage for details.
		1355
		1356	=cut
		1357
		1358	package AE;
		1359
		1360	our $VERSION = $AnyEvent::VERSION;
		1361
		1362	# fall back to the main API by default - backends and AnyEvent::Base
		1363	# implementations can overwrite these.
		1364
		1365	sub io($$$) {
		1366	AnyEvent->io (fh => $_[0], poll => $_[1] ? "w" : "r", cb => $_[2])
		1367	}
		1368
		1369	sub timer($$$) {
		1370	AnyEvent->timer (after => $_[0], interval => $_[1], cb => $_[2])
		1371	}
		1372
		1373	sub signal($$) {
		1374	AnyEvent->signal (signal => $_[0], cb => $_[1])
		1375	}
		1376
		1377	sub child($$) {
		1378	AnyEvent->child (pid => $_[0], cb => $_[1])
		1379	}
		1380
		1381	sub idle($) {
		1382	AnyEvent->idle (cb => $_[0])
		1383	}
		1384
		1385	sub cv(;&) {
		1386	AnyEvent->condvar (@_ ? (cb => $_[0]) : ())
		1387	}
		1388
		1389	sub now() {
		1390	AnyEvent->now
		1391	}
		1392
		1393	sub now_update() {
		1394	AnyEvent->now_update
		1395	}
		1396
		1397	sub time() {
		1398	AnyEvent->time
		1399	}
		1400
1241	package AnyEvent::Base;	1401	package AnyEvent::Base;
1242		1402
1243	# default implementations for many methods	1403	# default implementations for many methods
1244		1404
1245	sub _time {	1405	sub time {
		1406	eval q{ # poor man's autoloading {}
1246	# probe for availability of Time::HiRes	1407	# probe for availability of Time::HiRes
1247	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {	1408	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {
1248	warn "AnyEvent: using Time::HiRes for sub-second timing accuracy.\n" if $VERBOSE >= 8;	1409	warn "AnyEvent: using Time::HiRes for sub-second timing accuracy.\n" if $VERBOSE >= 8;
1249	*_time = \&Time::HiRes::time;	1410	*AE::time = \&Time::HiRes::time;
1250	# if (eval "use POSIX (); (POSIX::times())...	1411	# if (eval "use POSIX (); (POSIX::times())...
1251	} else {	1412	} else {
1252	warn "AnyEvent: using built-in time(), WARNING, no sub-second resolution!\n" if $VERBOSE;	1413	warn "AnyEvent: using built-in time(), WARNING, no sub-second resolution!\n" if $VERBOSE;
1253	*_time = sub { time }; # epic fail	1414	*AE::time = sub (){ time }; # epic fail
		1415	}
		1416
		1417	*time = sub { AE::time }; # different prototypes
1254	}	1418	};
		1419	die if $@;
1255		1420
1256	&_time	1421	&time
1257	}	1422	}
1258		1423
1259	sub time { _time }	1424	*now = \&time;
1260	sub now { _time }	1425
1261	sub now_update { }	1426	sub now_update { }
1262		1427
		1428	sub _poll {
		1429	Carp::croak "$AnyEvent::MODEL does not support blocking waits. Caught";
		1430	}
		1431
1263	# default implementation for ->condvar	1432	# default implementation for ->condvar
		1433	# in fact,t he default should not be overwritten
1264		1434
1265	sub condvar {	1435	sub condvar {
		1436	eval q{ # poor man's autoloading {}
		1437	*condvar = sub {
1266	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"	1438	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"
		1439	};
		1440
		1441	*AE::cv = sub (;&) {
		1442	bless { @_ ? (_ae_cb => shift) : () }, "AnyEvent::CondVar"
		1443	};
		1444	};
		1445	die if $@;
		1446
		1447	&condvar
1267	}	1448	}
1268		1449
1269	# default implementation for ->signal	1450	# default implementation for ->signal
1270		1451
1271	our $HAVE_ASYNC_INTERRUPT;	1452	our $HAVE_ASYNC_INTERRUPT;
		1453
		1454	sub _have_async_interrupt() {
		1455	$HAVE_ASYNC_INTERRUPT = 1*(!$ENV{PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT}
		1456	&& eval "use Async::Interrupt 1.02 (); 1")
		1457	unless defined $HAVE_ASYNC_INTERRUPT;
		1458
		1459	$HAVE_ASYNC_INTERRUPT
		1460	}
		1461
1272	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);	1462	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);
1273	our (%SIG_ASY, %SIG_ASY_W);	1463	our (%SIG_ASY, %SIG_ASY_W);
1274	our ($SIG_COUNT, $SIG_TW);	1464	our ($SIG_COUNT, $SIG_TW);
1275		1465
1276	sub _signal_exec {
1277	$HAVE_ASYNC_INTERRUPT
1278	? $SIGPIPE_R->drain
1279	: sysread $SIGPIPE_R, my $dummy, 9;
1280
1281	while (%SIG_EV) {
1282	for (keys %SIG_EV) {
1283	delete $SIG_EV{$_};
1284	$_->() for values %{ $SIG_CB{$_} || {} };
1285	}
1286	}
1287	}
1288
1289	# install a dumym wakeupw atcher to reduce signal catching latency	1466	# install a dummy wakeup watcher to reduce signal catching latency
		1467	# used by Impls
1290	sub _sig_add() {	1468	sub _sig_add() {
1291	unless ($SIG_COUNT++) {	1469	unless ($SIG_COUNT++) {
1292	# try to align timer on a full-second boundary, if possible	1470	# try to align timer on a full-second boundary, if possible
1293	my $NOW = AnyEvent->now;	1471	my $NOW = AE::now;
1294		1472
1295	$SIG_TW = AnyEvent->timer (	1473	$SIG_TW = AE::timer
1296	after => $MAX_SIGNAL_LATENCY - ($NOW - int $NOW),	1474	$MAX_SIGNAL_LATENCY - ($NOW - int $NOW),
1297	interval => $MAX_SIGNAL_LATENCY,	1475	$MAX_SIGNAL_LATENCY,
1298	cb => sub { }, # just for the PERL_ASYNC_CHECK	1476	sub { } # just for the PERL_ASYNC_CHECK
1299	);	1477	;
1300	}	1478	}
1301	}	1479	}
1302		1480
1303	sub _sig_del {	1481	sub _sig_del {
1304	undef $SIG_TW	1482	undef $SIG_TW
1305	unless --$SIG_COUNT;	1483	unless --$SIG_COUNT;
1306	}	1484	}
1307		1485
		1486	our $_sig_name_init; $_sig_name_init = sub {
		1487	eval q{ # poor man's autoloading {}
		1488	undef $_sig_name_init;
		1489
		1490	if (_have_async_interrupt) {
		1491	*sig2num = \&Async::Interrupt::sig2num;
		1492	*sig2name = \&Async::Interrupt::sig2name;
		1493	} else {
		1494	require Config;
		1495
		1496	my %signame2num;
		1497	@signame2num{ split ' ', $Config::Config{sig_name} }
		1498	= split ' ', $Config::Config{sig_num};
		1499
		1500	my @signum2name;
		1501	@signum2name[values %signame2num] = keys %signame2num;
		1502
		1503	*sig2num = sub($) {
		1504	$_[0] > 0 ? shift : $signame2num{+shift}
		1505	};
		1506	*sig2name = sub ($) {
		1507	$_[0] > 0 ? $signum2name[+shift] : shift
		1508	};
		1509	}
		1510	};
		1511	die if $@;
		1512	};
		1513
		1514	sub sig2num ($) { &$_sig_name_init; &sig2num }
		1515	sub sig2name($) { &$_sig_name_init; &sig2name }
		1516
1308	sub _signal {	1517	sub signal {
1309	my (undef, %arg) = @_;	1518	eval q{ # poor man's autoloading {}
		1519	# probe for availability of Async::Interrupt
		1520	if (_have_async_interrupt) {
		1521	warn "AnyEvent: using Async::Interrupt for race-free signal handling.\n" if $VERBOSE >= 8;
1310		1522
1311	my $signal = uc $arg{signal}	1523	$SIGPIPE_R = new Async::Interrupt::EventPipe;
1312	or Carp::croak "required option 'signal' is missing";	1524	$SIG_IO = AE::io $SIGPIPE_R->fileno, 0, \&_signal_exec;
1313		1525
1314	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};	1526	} else {
		1527	warn "AnyEvent: using emulated perl signal handling with latency timer.\n" if $VERBOSE >= 8;
1315		1528
1316	if ($HAVE_ASYNC_INTERRUPT) {	1529	if (AnyEvent::WIN32) {
1317	# async::interrupt	1530	require AnyEvent::Util;
1318		1531
1319	$SIG_ASY{$signal} ||= do {	1532	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
1320	my $asy = new Async::Interrupt	1533	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R, 1) if $SIGPIPE_R;
1321	cb => sub { undef $SIG_EV{$signal} },	1534	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W, 1) if $SIGPIPE_W; # just in case
1322	signal => $signal,	1535	} else {
1323	pipe => [$SIGPIPE_R->filenos],	1536	pipe $SIGPIPE_R, $SIGPIPE_W;
		1537	fcntl $SIGPIPE_R, AnyEvent::F_SETFL, AnyEvent::O_NONBLOCK if $SIGPIPE_R;
		1538	fcntl $SIGPIPE_W, AnyEvent::F_SETFL, AnyEvent::O_NONBLOCK if $SIGPIPE_W; # just in case
		1539
		1540	# not strictly required, as $^F is normally 2, but let's make sure...
		1541	fcntl $SIGPIPE_R, AnyEvent::F_SETFD, AnyEvent::FD_CLOEXEC;
		1542	fcntl $SIGPIPE_W, AnyEvent::F_SETFD, AnyEvent::FD_CLOEXEC;
1324	;	1543	}
1325	$asy->pipe_autodrain (0);
1326		1544
1327	$asy	1545	$SIGPIPE_R
		1546	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";
		1547
		1548	$SIG_IO = AE::io $SIGPIPE_R, 0, \&_signal_exec;
		1549	}
		1550
		1551	*signal = $HAVE_ASYNC_INTERRUPT
		1552	? sub {
		1553	my (undef, %arg) = @_;
		1554
		1555	# async::interrupt
		1556	my $signal = sig2num $arg{signal};
		1557	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
		1558
		1559	$SIG_ASY{$signal} ||= new Async::Interrupt
		1560	cb => sub { undef $SIG_EV{$signal} },
		1561	signal => $signal,
		1562	pipe => [$SIGPIPE_R->filenos],
		1563	pipe_autodrain => 0,
		1564	;
		1565
		1566	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
		1567	}
		1568	: sub {
		1569	my (undef, %arg) = @_;
		1570
		1571	# pure perl
		1572	my $signal = sig2name $arg{signal};
		1573	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
		1574
		1575	$SIG{$signal} ||= sub {
		1576	local $!;
		1577	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;
		1578	undef $SIG_EV{$signal};
		1579	};
		1580
		1581	# can't do signal processing without introducing races in pure perl,
		1582	# so limit the signal latency.
		1583	_sig_add;
		1584
		1585	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
		1586	}
		1587	;
		1588
		1589	*AnyEvent::Base::signal::DESTROY = sub {
		1590	my ($signal, $cb) = @{$_[0]};
		1591
		1592	_sig_del;
		1593
		1594	delete $SIG_CB{$signal}{$cb};
		1595
		1596	$HAVE_ASYNC_INTERRUPT
		1597	? delete $SIG_ASY{$signal}
		1598	: # delete doesn't work with older perls - they then
		1599	# print weird messages, or just unconditionally exit
		1600	# instead of getting the default action.
		1601	undef $SIG{$signal}
		1602	unless keys %{ $SIG_CB{$signal} };
1328	};	1603	};
1329		1604
1330	} else {	1605	*_signal_exec = sub {
1331	# pure perl	1606	$HAVE_ASYNC_INTERRUPT
		1607	? $SIGPIPE_R->drain
		1608	: sysread $SIGPIPE_R, (my $dummy), 9;
1332		1609
1333	$SIG{$signal} ||= sub {	1610	while (%SIG_EV) {
1334	local $!;	1611	for (keys %SIG_EV) {
1335	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;	1612	delete $SIG_EV{$_};
1336	undef $SIG_EV{$signal};	1613	$_->() for values %{ $SIG_CB{$_} || {} };
		1614	}
		1615	}
1337	};	1616	};
1338
1339	# can't do signal processing without introducing races in pure perl,
1340	# so limit the signal latency.
1341	_sig_add;
1342	}	1617	};
		1618	die if $@;
1343		1619
1344	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
1345	}
1346
1347	sub signal {
1348	# probe for availability of Async::Interrupt
1349	if (!$ENV{PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT} && eval "use Async::Interrupt 0.6 (); 1") {
1350	warn "AnyEvent: using Async::Interrupt for race-free signal handling.\n" if $VERBOSE >= 8;
1351
1352	$HAVE_ASYNC_INTERRUPT = 1;
1353	$SIGPIPE_R = new Async::Interrupt::EventPipe;
1354	$SIG_IO = AnyEvent->io (fh => $SIGPIPE_R->fileno, poll => "r", cb => \&_signal_exec);
1355
1356	} else {
1357	warn "AnyEvent: using emulated perl signal handling with latency timer.\n" if $VERBOSE >= 8;
1358
1359	require Fcntl;
1360
1361	if (AnyEvent::WIN32) {
1362	require AnyEvent::Util;
1363
1364	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
1365	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R) if $SIGPIPE_R;
1366	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W) if $SIGPIPE_W; # just in case
1367	} else {
1368	pipe $SIGPIPE_R, $SIGPIPE_W;
1369	fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R;
1370	fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case
1371
1372	# not strictly required, as $^F is normally 2, but let's make sure...
1373	fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
1374	fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
1375	}
1376
1377	$SIGPIPE_R
1378	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";
1379
1380	$SIG_IO = AnyEvent->io (fh => $SIGPIPE_R, poll => "r", cb => \&_signal_exec);
1381	}
1382
1383	*signal = \&_signal;
1384	&signal	1620	&signal
1385	}
1386
1387	sub AnyEvent::Base::signal::DESTROY {
1388	my ($signal, $cb) = @{$_[0]};
1389
1390	_sig_del;
1391
1392	delete $SIG_CB{$signal}{$cb};
1393
1394	$HAVE_ASYNC_INTERRUPT
1395	? delete $SIG_ASY{$signal}
1396	: # delete doesn't work with older perls - they then
1397	# print weird messages, or just unconditionally exit
1398	# instead of getting the default action.
1399	undef $SIG{$signal}
1400	unless keys %{ $SIG_CB{$signal} };
1401	}	1621	}
1402		1622
1403	# default implementation for ->child	1623	# default implementation for ->child
1404		1624
1405	our %PID_CB;	1625	our %PID_CB;
1406	our $CHLD_W;	1626	our $CHLD_W;
1407	our $CHLD_DELAY_W;	1627	our $CHLD_DELAY_W;
1408	our $WNOHANG;
1409		1628
1410	sub _sigchld {	1629	# used by many Impl's
1411	while (0 < (my $pid = waitpid -1, $WNOHANG)) {	1630	sub _emit_childstatus($$) {
1412	$_->($pid, $?)	1631	my (undef, $rpid, $rstatus) = @_;
		1632
		1633	$_->($rpid, $rstatus)
1413	for values %{ $PID_CB{$pid} || {} },	1634	for values %{ $PID_CB{$rpid} || {} },
1414	values %{ $PID_CB{0} || {} };	1635	values %{ $PID_CB{0} || {} };
1415	}
1416	}	1636	}
1417		1637
1418	sub child {	1638	sub child {
		1639	eval q{ # poor man's autoloading {}
		1640	*_sigchld = sub {
		1641	my $pid;
		1642
		1643	AnyEvent->_emit_childstatus ($pid, $?)
		1644	while ($pid = waitpid -1, WNOHANG) > 0;
		1645	};
		1646
		1647	*child = sub {
1419	my (undef, %arg) = @_;	1648	my (undef, %arg) = @_;
1420		1649
1421	defined (my $pid = $arg{pid} + 0)	1650	my $pid = $arg{pid};
1422	or Carp::croak "required option 'pid' is missing";	1651	my $cb = $arg{cb};
1423		1652
1424	$PID_CB{$pid}{$arg{cb}} = $arg{cb};	1653	$PID_CB{$pid}{$cb+0} = $cb;
1425		1654
1426	# WNOHANG is almost cetrainly 1 everywhere
1427	$WNOHANG ||= $^O =~ /^(?:openbsd|netbsd|linux|freebsd|cygwin|MSWin32)$/
1428	? 1
1429	: eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1;
1430
1431	unless ($CHLD_W) {	1655	unless ($CHLD_W) {
1432	$CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld);	1656	$CHLD_W = AE::signal CHLD => \&_sigchld;
1433	# child could be a zombie already, so make at least one round	1657	# child could be a zombie already, so make at least one round
1434	&_sigchld;	1658	&_sigchld;
1435	}	1659	}
1436		1660
1437	bless [$pid, $arg{cb}], "AnyEvent::Base::child"	1661	bless [$pid, $cb+0], "AnyEvent::Base::child"
1438	}	1662	};
1439		1663
1440	sub AnyEvent::Base::child::DESTROY {	1664	*AnyEvent::Base::child::DESTROY = sub {
1441	my ($pid, $cb) = @{$_[0]};	1665	my ($pid, $icb) = @{$_[0]};
1442		1666
1443	delete $PID_CB{$pid}{$cb};	1667	delete $PID_CB{$pid}{$icb};
1444	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };	1668	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };
1445		1669
1446	undef $CHLD_W unless keys %PID_CB;	1670	undef $CHLD_W unless keys %PID_CB;
		1671	};
		1672	};
		1673	die if $@;
		1674
		1675	&child
1447	}	1676	}
1448		1677
1449	# idle emulation is done by simply using a timer, regardless	1678	# idle emulation is done by simply using a timer, regardless
1450	# of whether the process is idle or not, and not letting	1679	# of whether the process is idle or not, and not letting
1451	# the callback use more than 50% of the time.	1680	# the callback use more than 50% of the time.
1452	sub idle {	1681	sub idle {
		1682	eval q{ # poor man's autoloading {}
		1683	*idle = sub {
1453	my (undef, %arg) = @_;	1684	my (undef, %arg) = @_;
1454		1685
1455	my ($cb, $w, $rcb) = $arg{cb};	1686	my ($cb, $w, $rcb) = $arg{cb};
1456		1687
1457	$rcb = sub {	1688	$rcb = sub {
1458	if ($cb) {	1689	if ($cb) {
1459	$w = _time;	1690	$w = _time;
1460	&$cb;	1691	&$cb;
1461	$w = _time - $w;	1692	$w = _time - $w;
1462		1693
1463	# never use more then 50% of the time for the idle watcher,	1694	# never use more then 50% of the time for the idle watcher,
1464	# within some limits	1695	# within some limits
1465	$w = 0.0001 if $w < 0.0001;	1696	$w = 0.0001 if $w < 0.0001;
1466	$w = 5 if $w > 5;	1697	$w = 5 if $w > 5;
1467		1698
1468	$w = AnyEvent->timer (after => $w, cb => $rcb);	1699	$w = AE::timer $w, 0, $rcb;
1469	} else {	1700	} else {
1470	# clean up...	1701	# clean up...
1471	undef $w;	1702	undef $w;
1472	undef $rcb;	1703	undef $rcb;
		1704	}
		1705	};
		1706
		1707	$w = AE::timer 0.05, 0, $rcb;
		1708
		1709	bless \\$cb, "AnyEvent::Base::idle"
1473	}	1710	};
		1711
		1712	*AnyEvent::Base::idle::DESTROY = sub {
		1713	undef $${$_[0]};
		1714	};
1474	};	1715	};
		1716	die if $@;
1475		1717
1476	$w = AnyEvent->timer (after => 0.05, cb => $rcb);	1718	&idle
1477
1478	bless \\$cb, "AnyEvent::Base::idle"
1479	}
1480
1481	sub AnyEvent::Base::idle::DESTROY {
1482	undef $${$_[0]};
1483	}	1719	}
1484		1720
1485	package AnyEvent::CondVar;	1721	package AnyEvent::CondVar;
1486		1722
1487	our @ISA = AnyEvent::CondVar::Base::;	1723	our @ISA = AnyEvent::CondVar::Base::;
		1724
		1725	# only to be used for subclassing
		1726	sub new {
		1727	my $class = shift;
		1728	bless AnyEvent->condvar (@_), $class
		1729	}
1488		1730
1489	package AnyEvent::CondVar::Base;	1731	package AnyEvent::CondVar::Base;
1490		1732
1491	#use overload	1733	#use overload
1492	# '&{}' => sub { my $self = shift; sub { $self->send (@_) } },	1734	# '&{}' => sub { my $self = shift; sub { $self->send (@_) } },
…		…
1502		1744
1503	sub _send {	1745	sub _send {
1504	# nop	1746	# nop
1505	}	1747	}
1506		1748
		1749	sub _wait {
		1750	AnyEvent->_poll until $_[0]{_ae_sent};
		1751	}
		1752
1507	sub send {	1753	sub send {
1508	my $cv = shift;	1754	my $cv = shift;
1509	$cv->{_ae_sent} = [@_];	1755	$cv->{_ae_sent} = [@_];
1510	(delete $cv->{_ae_cb})->($cv) if $cv->{_ae_cb};	1756	(delete $cv->{_ae_cb})->($cv) if $cv->{_ae_cb};
1511	$cv->_send;	1757	$cv->_send;
…		…
1518		1764
1519	sub ready {	1765	sub ready {
1520	$_[0]{_ae_sent}	1766	$_[0]{_ae_sent}
1521	}	1767	}
1522		1768
1523	sub _wait {
1524	$WAITING
1525	and !$_[0]{_ae_sent}
1526	and Carp::croak "AnyEvent::CondVar: recursive blocking wait detected";
1527
1528	local $WAITING = 1;
1529	AnyEvent->one_event while !$_[0]{_ae_sent};
1530	}
1531
1532	sub recv {	1769	sub recv {
		1770	unless ($_[0]{_ae_sent}) {
		1771	$WAITING
		1772	and Carp::croak "AnyEvent::CondVar: recursive blocking wait attempted";
		1773
		1774	local $WAITING = 1;
1533	$_[0]->_wait;	1775	$_[0]->_wait;
		1776	}
1534		1777
1535	Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak};	1778	$_[0]{_ae_croak}
1536	wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0]	1779	and Carp::croak $_[0]{_ae_croak};
		1780
		1781	wantarray
		1782	? @{ $_[0]{_ae_sent} }
		1783	: $_[0]{_ae_sent}[0]
1537	}	1784	}
1538		1785
1539	sub cb {	1786	sub cb {
1540	$_[0]{_ae_cb} = $_[1] if @_ > 1;	1787	my $cv = shift;
		1788
		1789	@_
		1790	and $cv->{_ae_cb} = shift
		1791	and $cv->{_ae_sent}
		1792	and (delete $cv->{_ae_cb})->($cv);
		1793
1541	$_[0]{_ae_cb}	1794	$cv->{_ae_cb}
1542	}	1795	}
1543		1796
1544	sub begin {	1797	sub begin {
1545	++$_[0]{_ae_counter};	1798	++$_[0]{_ae_counter};
1546	$_[0]{_ae_end_cb} = $_[1] if @_ > 1;	1799	$_[0]{_ae_end_cb} = $_[1] if @_ > 1;
…		…
1551	&{ $_[0]{_ae_end_cb} || sub { $_[0]->send } };	1804	&{ $_[0]{_ae_end_cb} || sub { $_[0]->send } };
1552	}	1805	}
1553		1806
1554	# undocumented/compatibility with pre-3.4	1807	# undocumented/compatibility with pre-3.4
1555	*broadcast = \&send;	1808	*broadcast = \&send;
1556	*wait = \&_wait;	1809	*wait = \&recv;
1557		1810
1558	=head1 ERROR AND EXCEPTION HANDLING	1811	=head1 ERROR AND EXCEPTION HANDLING
1559		1812
1560	In general, AnyEvent does not do any error handling - it relies on the	1813	In general, AnyEvent does not do any error handling - it relies on the
1561	caller to do that if required. The L<AnyEvent::Strict> module (see also	1814	caller to do that if required. The L<AnyEvent::Strict> module (see also
…		…
1608	check the arguments passed to most method calls. If it finds any problems,	1861	check the arguments passed to most method calls. If it finds any problems,
1609	it will croak.	1862	it will croak.
1610		1863
1611	In other words, enables "strict" mode.	1864	In other words, enables "strict" mode.
1612		1865
1613	Unlike C<use strict> (or it's modern cousin, C<< use L<common::sense>	1866	Unlike C<use strict> (or its modern cousin, C<< use L<common::sense>
1614	>>, it is definitely recommended to keep it off in production. Keeping	1867	>>, it is definitely recommended to keep it off in production. Keeping
1615	C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs	1868	C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs
1616	can be very useful, however.	1869	can be very useful, however.
1617		1870
1618	=item C<PERL_ANYEVENT_MODEL>	1871	=item C<PERL_ANYEVENT_MODEL>
…		…
1624	used as event model. If it fails to load AnyEvent will proceed with	1877	used as event model. If it fails to load AnyEvent will proceed with
1625	auto detection and -probing.	1878	auto detection and -probing.
1626		1879
1627	This functionality might change in future versions.	1880	This functionality might change in future versions.
1628		1881
1629	For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you	1882	For example, to force the pure perl model (L<AnyEvent::Loop::Perl>) you
1630	could start your program like this:	1883	could start your program like this:
1631		1884
1632	PERL_ANYEVENT_MODEL=Perl perl ...	1885	PERL_ANYEVENT_MODEL=Perl perl ...
1633		1886
1634	=item C<PERL_ANYEVENT_PROTOCOLS>	1887	=item C<PERL_ANYEVENT_PROTOCOLS>
…		…
1755	warn "read: $input\n"; # output what has been read	2008	warn "read: $input\n"; # output what has been read
1756	$cv->send if $input =~ /^q/i; # quit program if /^q/i	2009	$cv->send if $input =~ /^q/i; # quit program if /^q/i
1757	},	2010	},
1758	);	2011	);
1759		2012
1760	my $time_watcher; # can only be used once
1761
1762	sub new_timer {
1763	$timer = AnyEvent->timer (after => 1, cb => sub {	2013	my $time_watcher = AnyEvent->timer (after => 1, interval => 1, cb => sub {
1764	warn "timeout\n"; # print 'timeout' about every second	2014	warn "timeout\n"; # print 'timeout' at most every second
1765	&new_timer; # and restart the time
1766	});	2015	});
1767	}
1768
1769	new_timer; # create first timer
1770		2016
1771	$cv->recv; # wait until user enters /^q/i	2017	$cv->recv; # wait until user enters /^q/i
1772		2018
1773	=head1 REAL-WORLD EXAMPLE	2019	=head1 REAL-WORLD EXAMPLE
1774		2020
…		…
1847		2093
1848	The actual code goes further and collects all errors (C<die>s, exceptions)	2094	The actual code goes further and collects all errors (C<die>s, exceptions)
1849	that occurred during request processing. The C<result> method detects	2095	that occurred during request processing. The C<result> method detects
1850	whether an exception as thrown (it is stored inside the $txn object)	2096	whether an exception as thrown (it is stored inside the $txn object)
1851	and just throws the exception, which means connection errors and other	2097	and just throws the exception, which means connection errors and other
1852	problems get reported tot he code that tries to use the result, not in a	2098	problems get reported to the code that tries to use the result, not in a
1853	random callback.	2099	random callback.
1854		2100
1855	All of this enables the following usage styles:	2101	All of this enables the following usage styles:
1856		2102
1857	1. Blocking:	2103	1. Blocking:
…		…
1905	through AnyEvent. The benchmark creates a lot of timers (with a zero	2151	through AnyEvent. The benchmark creates a lot of timers (with a zero
1906	timeout) and I/O watchers (watching STDOUT, a pty, to become writable,	2152	timeout) and I/O watchers (watching STDOUT, a pty, to become writable,
1907	which it is), lets them fire exactly once and destroys them again.	2153	which it is), lets them fire exactly once and destroys them again.
1908		2154
1909	Source code for this benchmark is found as F<eg/bench> in the AnyEvent	2155	Source code for this benchmark is found as F<eg/bench> in the AnyEvent
1910	distribution.	2156	distribution. It uses the L<AE> interface, which makes a real difference
		2157	for the EV and Perl backends only.
1911		2158
1912	=head3 Explanation of the columns	2159	=head3 Explanation of the columns
1913		2160
1914	I<watcher> is the number of event watchers created/destroyed. Since	2161	I<watcher> is the number of event watchers created/destroyed. Since
1915	different event models feature vastly different performances, each event	2162	different event models feature vastly different performances, each event
…		…
1936	watcher.	2183	watcher.
1937		2184
1938	=head3 Results	2185	=head3 Results
1939		2186
1940	name watchers bytes create invoke destroy comment	2187	name watchers bytes create invoke destroy comment
1941	EV/EV 400000 224 0.47 0.35 0.27 EV native interface	2188	EV/EV 100000 223 0.47 0.43 0.27 EV native interface
1942	EV/Any 100000 224 2.88 0.34 0.27 EV + AnyEvent watchers	2189	EV/Any 100000 223 0.48 0.42 0.26 EV + AnyEvent watchers
1943	CoroEV/Any 100000 224 2.85 0.35 0.28 coroutines + Coro::Signal	2190	Coro::EV/Any 100000 223 0.47 0.42 0.26 coroutines + Coro::Signal
1944	Perl/Any 100000 452 4.13 0.73 0.95 pure perl implementation	2191	Perl/Any 100000 431 2.70 0.74 0.92 pure perl implementation
1945	Event/Event 16000 517 32.20 31.80 0.81 Event native interface	2192	Event/Event 16000 516 31.16 31.84 0.82 Event native interface
1946	Event/Any 16000 590 35.85 31.55 1.06 Event + AnyEvent watchers	2193	Event/Any 16000 1203 42.61 34.79 1.80 Event + AnyEvent watchers
1947	IOAsync/Any 16000 989 38.10 32.77 11.13 via IO::Async::Loop::IO_Poll	2194	IOAsync/Any 16000 1911 41.92 27.45 16.81 via IO::Async::Loop::IO_Poll
1948	IOAsync/Any 16000 990 37.59 29.50 10.61 via IO::Async::Loop::Epoll	2195	IOAsync/Any 16000 1726 40.69 26.37 15.25 via IO::Async::Loop::Epoll
1949	Glib/Any 16000 1357 102.33 12.31 51.00 quadratic behaviour	2196	Glib/Any 16000 1118 89.00 12.57 51.17 quadratic behaviour
1950	Tk/Any 2000 1860 27.20 66.31 14.00 SEGV with >> 2000 watchers	2197	Tk/Any 2000 1346 20.96 10.75 8.00 SEGV with >> 2000 watchers
1951	POE/Event 2000 6328 109.99 751.67 14.02 via POE::Loop::Event	2198	POE/Any 2000 6951 108.97 795.32 14.24 via POE::Loop::Event
1952	POE/Select 2000 6027 94.54 809.13 579.80 via POE::Loop::Select	2199	POE/Any 2000 6648 94.79 774.40 575.51 via POE::Loop::Select
1953		2200
1954	=head3 Discussion	2201	=head3 Discussion
1955		2202
1956	The benchmark does I<not> measure scalability of the event loop very	2203	The benchmark does I<not> measure scalability of the event loop very
1957	well. For example, a select-based event loop (such as the pure perl one)	2204	well. For example, a select-based event loop (such as the pure perl one)
…		…
1969	benchmark machine, handling an event takes roughly 1600 CPU cycles with	2216	benchmark machine, handling an event takes roughly 1600 CPU cycles with
1970	EV, 3100 CPU cycles with AnyEvent's pure perl loop and almost 3000000 CPU	2217	EV, 3100 CPU cycles with AnyEvent's pure perl loop and almost 3000000 CPU
1971	cycles with POE.	2218	cycles with POE.
1972		2219
1973	C<EV> is the sole leader regarding speed and memory use, which are both	2220	C<EV> is the sole leader regarding speed and memory use, which are both
1974	maximal/minimal, respectively. Even when going through AnyEvent, it uses	2221	maximal/minimal, respectively. When using the L<AE> API there is zero
		2222	overhead (when going through the AnyEvent API create is about 5-6 times
		2223	slower, with other times being equal, so still uses far less memory than
1975	far less memory than any other event loop and is still faster than Event	2224	any other event loop and is still faster than Event natively).
1976	natively.
1977		2225
1978	The pure perl implementation is hit in a few sweet spots (both the	2226	The pure perl implementation is hit in a few sweet spots (both the
1979	constant timeout and the use of a single fd hit optimisations in the perl	2227	constant timeout and the use of a single fd hit optimisations in the perl
1980	interpreter and the backend itself). Nevertheless this shows that it	2228	interpreter and the backend itself). Nevertheless this shows that it
1981	adds very little overhead in itself. Like any select-based backend its	2229	adds very little overhead in itself. Like any select-based backend its
…		…
2055	In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100	2303	In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100
2056	(1%) are active. This mirrors the activity of large servers with many	2304	(1%) are active. This mirrors the activity of large servers with many
2057	connections, most of which are idle at any one point in time.	2305	connections, most of which are idle at any one point in time.
2058		2306
2059	Source code for this benchmark is found as F<eg/bench2> in the AnyEvent	2307	Source code for this benchmark is found as F<eg/bench2> in the AnyEvent
2060	distribution.	2308	distribution. It uses the L<AE> interface, which makes a real difference
		2309	for the EV and Perl backends only.
2061		2310
2062	=head3 Explanation of the columns	2311	=head3 Explanation of the columns
2063		2312
2064	I<sockets> is the number of sockets, and twice the number of "servers" (as	2313	I<sockets> is the number of sockets, and twice the number of "servers" (as
2065	each server has a read and write socket end).	2314	each server has a read and write socket end).
…		…
2073	a new one that moves the timeout into the future.	2322	a new one that moves the timeout into the future.
2074		2323
2075	=head3 Results	2324	=head3 Results
2076		2325
2077	name sockets create request	2326	name sockets create request
2078	EV 20000 69.01 11.16	2327	EV 20000 62.66 7.99
2079	Perl 20000 73.32 35.87	2328	Perl 20000 68.32 32.64
2080	IOAsync 20000 157.00 98.14 epoll	2329	IOAsync 20000 174.06 101.15 epoll
2081	IOAsync 20000 159.31 616.06 poll	2330	IOAsync 20000 174.67 610.84 poll
2082	Event 20000 212.62 257.32	2331	Event 20000 202.69 242.91
2083	Glib 20000 651.16 1896.30	2332	Glib 20000 557.01 1689.52
2084	POE 20000 349.67 12317.24 uses POE::Loop::Event	2333	POE 20000 341.54 12086.32 uses POE::Loop::Event
2085		2334
2086	=head3 Discussion	2335	=head3 Discussion
2087		2336
2088	This benchmark I<does> measure scalability and overall performance of the	2337	This benchmark I<does> measure scalability and overall performance of the
2089	particular event loop.	2338	particular event loop.
…		…
2215	As you can see, the AnyEvent + EV combination even beats the	2464	As you can see, the AnyEvent + EV combination even beats the
2216	hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl	2465	hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl
2217	backend easily beats IO::Lambda and POE.	2466	backend easily beats IO::Lambda and POE.
2218		2467
2219	And even the 100% non-blocking version written using the high-level (and	2468	And even the 100% non-blocking version written using the high-level (and
2220	slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda by a	2469	slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda
2221	large margin, even though it does all of DNS, tcp-connect and socket I/O	2470	higher level ("unoptimised") abstractions by a large margin, even though
2222	in a non-blocking way.	2471	it does all of DNS, tcp-connect and socket I/O in a non-blocking way.
2223		2472
2224	The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and	2473	The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and
2225	F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are	2474	F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are
2226	part of the IO::lambda distribution and were used without any changes.	2475	part of the IO::Lambda distribution and were used without any changes.
2227		2476
2228		2477
2229	=head1 SIGNALS	2478	=head1 SIGNALS
2230		2479
2231	AnyEvent currently installs handlers for these signals:	2480	AnyEvent currently installs handlers for these signals:
…		…
2268	unless defined $SIG{PIPE};	2517	unless defined $SIG{PIPE};
2269		2518
2270	=head1 RECOMMENDED/OPTIONAL MODULES	2519	=head1 RECOMMENDED/OPTIONAL MODULES
2271		2520
2272	One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and	2521	One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and
2273	it's built-in modules) are required to use it.	2522	its built-in modules) are required to use it.
2274		2523
2275	That does not mean that AnyEvent won't take advantage of some additional	2524	That does not mean that AnyEvent won't take advantage of some additional
2276	modules if they are installed.	2525	modules if they are installed.
2277		2526
2278	This section epxlains which additional modules will be used, and how they	2527	This section explains which additional modules will be used, and how they
2279	affect AnyEvent's operetion.	2528	affect AnyEvent's operation.
2280		2529
2281	=over 4	2530	=over 4
2282		2531
2283	=item L<Async::Interrupt>	2532	=item L<Async::Interrupt>
2284		2533
…		…
2289	catch the signals) with some delay (default is 10 seconds, look for	2538	catch the signals) with some delay (default is 10 seconds, look for
2290	C<$AnyEvent::MAX_SIGNAL_LATENCY>).	2539	C<$AnyEvent::MAX_SIGNAL_LATENCY>).
2291		2540
2292	If this module is available, then it will be used to implement signal	2541	If this module is available, then it will be used to implement signal
2293	catching, which means that signals will not be delayed, and the event loop	2542	catching, which means that signals will not be delayed, and the event loop
2294	will not be interrupted regularly, which is more efficient (And good for	2543	will not be interrupted regularly, which is more efficient (and good for
2295	battery life on laptops).	2544	battery life on laptops).
2296		2545
2297	This affects not just the pure-perl event loop, but also other event loops	2546	This affects not just the pure-perl event loop, but also other event loops
2298	that have no signal handling on their own (e.g. Glib, Tk, Qt).	2547	that have no signal handling on their own (e.g. Glib, Tk, Qt).
2299		2548
…		…
2311	automatic timer adjustments even when no monotonic clock is available,	2560	automatic timer adjustments even when no monotonic clock is available,
2312	can take avdantage of advanced kernel interfaces such as C<epoll> and	2561	can take avdantage of advanced kernel interfaces such as C<epoll> and
2313	C<kqueue>, and is the fastest backend I<by far>. You can even embed	2562	C<kqueue>, and is the fastest backend I<by far>. You can even embed
2314	L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>).	2563	L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>).
2315		2564
		2565	If you only use backends that rely on another event loop (e.g. C<Tk>),
		2566	then this module will do nothing for you.
		2567
2316	=item L<Guard>	2568	=item L<Guard>
2317		2569
2318	The guard module, when used, will be used to implement	2570	The guard module, when used, will be used to implement
2319	C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a	2571	C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a
2320	lot less memory), but otherwise doesn't affect guard operation much. It is	2572	lot less memory), but otherwise doesn't affect guard operation much. It is
2321	purely used for performance.	2573	purely used for performance.
2322		2574
2323	=item L<JSON> and L<JSON::XS>	2575	=item L<JSON> and L<JSON::XS>
2324		2576
2325	This module is required when you want to read or write JSON data via	2577	One of these modules is required when you want to read or write JSON data
2326	L<AnyEvent::Handle>. It is also written in pure-perl, but can take	2578	via L<AnyEvent::Handle>. L<JSON> is also written in pure-perl, but can take
2327	advantage of the ultra-high-speed L<JSON::XS> module when it is installed.	2579	advantage of the ultra-high-speed L<JSON::XS> module when it is installed.
2328
2329	In fact, L<AnyEvent::Handle> will use L<JSON::XS> by default if it is
2330	installed.
2331		2580
2332	=item L<Net::SSLeay>	2581	=item L<Net::SSLeay>
2333		2582
2334	Implementing TLS/SSL in Perl is certainly interesting, but not very	2583	Implementing TLS/SSL in Perl is certainly interesting, but not very
2335	worthwhile: If this module is installed, then L<AnyEvent::Handle> (with	2584	worthwhile: If this module is installed, then L<AnyEvent::Handle> (with
2336	the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL.	2585	the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL.
2337		2586
2338	=item L<Time::HiRes>	2587	=item L<Time::HiRes>
2339		2588
2340	This module is part of perl since release 5.008. It will be used when the	2589	This module is part of perl since release 5.008. It will be used when the
2341	chosen event library does not come with a timing source on it's own. The	2590	chosen event library does not come with a timing source of its own. The
2342	pure-perl event loop (L<AnyEvent::Impl::Perl>) will additionally use it to	2591	pure-perl event loop (L<AnyEvent::Loop>) will additionally load it to
2343	try to use a monotonic clock for timing stability.	2592	try to use a monotonic clock for timing stability.
2344		2593
2345	=back	2594	=back
2346		2595
2347		2596
2348	=head1 FORK	2597	=head1 FORK
2349		2598
2350	Most event libraries are not fork-safe. The ones who are usually are	2599	Most event libraries are not fork-safe. The ones who are usually are
2351	because they rely on inefficient but fork-safe C<select> or C<poll>	2600	because they rely on inefficient but fork-safe C<select> or C<poll> calls
2352	calls. Only L<EV> is fully fork-aware.	2601	- higher performance APIs such as BSD's kqueue or the dreaded Linux epoll
		2602	are usually badly thought-out hacks that are incompatible with fork in
		2603	one way or another. Only L<EV> is fully fork-aware and ensures that you
		2604	continue event-processing in both parent and child (or both, if you know
		2605	what you are doing).
		2606
		2607	This means that, in general, you cannot fork and do event processing in
		2608	the child if the event library was initialised before the fork (which
		2609	usually happens when the first AnyEvent watcher is created, or the library
		2610	is loaded).
2353		2611
2354	If you have to fork, you must either do so I<before> creating your first	2612	If you have to fork, you must either do so I<before> creating your first
2355	watcher OR you must not use AnyEvent at all in the child OR you must do	2613	watcher OR you must not use AnyEvent at all in the child OR you must do
2356	something completely out of the scope of AnyEvent.	2614	something completely out of the scope of AnyEvent.
		2615
		2616	The problem of doing event processing in the parent I<and> the child
		2617	is much more complicated: even for backends that I<are> fork-aware or
		2618	fork-safe, their behaviour is not usually what you want: fork clones all
		2619	watchers, that means all timers, I/O watchers etc. are active in both
		2620	parent and child, which is almost never what you want. USing C<exec>
		2621	to start worker children from some kind of manage rprocess is usually
		2622	preferred, because it is much easier and cleaner, at the expense of having
		2623	to have another binary.
2357		2624
2358		2625
2359	=head1 SECURITY CONSIDERATIONS	2626	=head1 SECURITY CONSIDERATIONS
2360		2627
2361	AnyEvent can be forced to load any event model via	2628	AnyEvent can be forced to load any event model via
…		…
2391	pronounced).	2658	pronounced).
2392		2659
2393		2660
2394	=head1 SEE ALSO	2661	=head1 SEE ALSO
2395		2662
		2663	Tutorial/Introduction: L<AnyEvent::Intro>.
		2664
		2665	FAQ: L<AnyEvent::FAQ>.
		2666
2396	Utility functions: L<AnyEvent::Util>.	2667	Utility functions: L<AnyEvent::Util>.
2397		2668
2398	Event modules: L<EV>, L<EV::Glib>, L<Glib::EV>, L<Event>, L<Glib::Event>,	2669	Event modules: L<AnyEvent::Loop>, L<EV>, L<EV::Glib>, L<Glib::EV>,
2399	L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.	2670	L<Event>, L<Glib::Event>, L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.
2400		2671
2401	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,	2672	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,
2402	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,	2673	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,
2403	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,	2674	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,
2404	L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>.	2675	L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>, L<Anyevent::Impl::Irssi>.
2405		2676
2406	Non-blocking file handles, sockets, TCP clients and	2677	Non-blocking file handles, sockets, TCP clients and
2407	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.	2678	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.
2408		2679
2409	Asynchronous DNS: L<AnyEvent::DNS>.	2680	Asynchronous DNS: L<AnyEvent::DNS>.
2410		2681
2411	Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>,	2682	Thread support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>.
2412	L<Coro::Event>,
2413		2683
2414	Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::XMPP>,	2684	Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::IRC>,
2415	L<AnyEvent::HTTP>.	2685	L<AnyEvent::HTTP>.
2416		2686
2417		2687
2418	=head1 AUTHOR	2688	=head1 AUTHOR
2419		2689

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