ViewVC Help

View File | Revision Log | Show Annotations | Download File

/cvs/AnyEvent/lib/AnyEvent.pm

Comparing AnyEvent/lib/AnyEvent.pm (file contents):
Revision 1.242 by root, Fri Jul 17 22:05:12 2009 UTC vs.
Revision 1.398 by root, Tue Mar 27 16:21:11 2012 UTC

1	=head1 NAME	1	=head1 NAME
2		2
3	AnyEvent - provide framework for multiple event loops	3	AnyEvent - the DBI of event loop programming
4		4
5	EV, Event, Glib, Tk, Perl, Event::Lib, Qt and POE are various supported	5	EV, Event, Glib, Tk, Perl, Event::Lib, Irssi, rxvt-unicode, IO::Async, Qt,
6	event loops.	6	FLTK and POE are various supported event loops/environments.
7		7
8	=head1 SYNOPSIS	8	=head1 SYNOPSIS
9		9
10	use AnyEvent;	10	use AnyEvent;
11		11
		12	# if you prefer function calls, look at the AE manpage for
		13	# an alternative API.
		14
12	# file descriptor readable	15	# file handle or descriptor readable
13	my $w = AnyEvent->io (fh => $fh, poll => "r", cb => sub { ... });	16	my $w = AnyEvent->io (fh => $fh, poll => "r", cb => sub { ... });
14		17
15	# one-shot or repeating timers	18	# one-shot or repeating timers
16	my $w = AnyEvent->timer (after => $seconds, cb => sub { ... });	19	my $w = AnyEvent->timer (after => $seconds, cb => sub { ... });
17	my $w = AnyEvent->timer (after => $seconds, interval => $seconds, cb => ...	20	my $w = AnyEvent->timer (after => $seconds, interval => $seconds, cb => ...);
18		21
19	print AnyEvent->now; # prints current event loop time	22	print AnyEvent->now; # prints current event loop time
20	print AnyEvent->time; # think Time::HiRes::time or simply CORE::time.	23	print AnyEvent->time; # think Time::HiRes::time or simply CORE::time.
21		24
22	# POSIX signal	25	# POSIX signal
…		…
40	=head1 INTRODUCTION/TUTORIAL	43	=head1 INTRODUCTION/TUTORIAL
41		44
42	This manpage is mainly a reference manual. If you are interested	45	This manpage is mainly a reference manual. If you are interested
43	in a tutorial or some gentle introduction, have a look at the	46	in a tutorial or some gentle introduction, have a look at the
44	L<AnyEvent::Intro> manpage.	47	L<AnyEvent::Intro> manpage.
		48
		49	=head1 SUPPORT
		50
		51	An FAQ document is available as L<AnyEvent::FAQ>.
		52
		53	There also is a mailinglist for discussing all things AnyEvent, and an IRC
		54	channel, too.
		55
		56	See the AnyEvent project page at the B<Schmorpforge Ta-Sa Software
		57	Repository>, at L<http://anyevent.schmorp.de>, for more info.
45		58
46	=head1 WHY YOU SHOULD USE THIS MODULE (OR NOT)	59	=head1 WHY YOU SHOULD USE THIS MODULE (OR NOT)
47		60
48	Glib, POE, IO::Async, Event... CPAN offers event models by the dozen	61	Glib, POE, IO::Async, Event... CPAN offers event models by the dozen
49	nowadays. So what is different about AnyEvent?	62	nowadays. So what is different about AnyEvent?
…		…
65	module users into the same thing by forcing them to use the same event	78	module users into the same thing by forcing them to use the same event
66	model you use.	79	model you use.
67		80
68	For modules like POE or IO::Async (which is a total misnomer as it is	81	For modules like POE or IO::Async (which is a total misnomer as it is
69	actually doing all I/O I<synchronously>...), using them in your module is	82	actually doing all I/O I<synchronously>...), using them in your module is
70	like joining a cult: After you joined, you are dependent on them and you	83	like joining a cult: After you join, you are dependent on them and you
71	cannot use anything else, as they are simply incompatible to everything	84	cannot use anything else, as they are simply incompatible to everything
72	that isn't them. What's worse, all the potential users of your	85	that isn't them. What's worse, all the potential users of your
73	module are I<also> forced to use the same event loop you use.	86	module are I<also> forced to use the same event loop you use.
74		87
75	AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works	88	AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works
76	fine. AnyEvent + Tk works fine etc. etc. but none of these work together	89	fine. AnyEvent + Tk works fine etc. etc. but none of these work together
77	with the rest: POE + IO::Async? No go. Tk + Event? No go. Again: if	90	with the rest: POE + EV? No go. Tk + Event? No go. Again: if your module
78	your module uses one of those, every user of your module has to use it,	91	uses one of those, every user of your module has to use it, too. But if
79	too. But if your module uses AnyEvent, it works transparently with all	92	your module uses AnyEvent, it works transparently with all event models it
80	event models it supports (including stuff like IO::Async, as long as those	93	supports (including stuff like IO::Async, as long as those use one of the
81	use one of the supported event loops. It is trivial to add new event loops	94	supported event loops. It is easy to add new event loops to AnyEvent, too,
82	to AnyEvent, too, so it is future-proof).	95	so it is future-proof).
83		96
84	In addition to being free of having to use I<the one and only true event	97	In addition to being free of having to use I<the one and only true event
85	model>, AnyEvent also is free of bloat and policy: with POE or similar	98	model>, AnyEvent also is free of bloat and policy: with POE or similar
86	modules, you get an enormous amount of code and strict rules you have to	99	modules, you get an enormous amount of code and strict rules you have to
87	follow. AnyEvent, on the other hand, is lean and up to the point, by only	100	follow. AnyEvent, on the other hand, is lean and to the point, by only
88	offering the functionality that is necessary, in as thin as a wrapper as	101	offering the functionality that is necessary, in as thin as a wrapper as
89	technically possible.	102	technically possible.
90		103
91	Of course, AnyEvent comes with a big (and fully optional!) toolbox	104	Of course, AnyEvent comes with a big (and fully optional!) toolbox
92	of useful functionality, such as an asynchronous DNS resolver, 100%	105	of useful functionality, such as an asynchronous DNS resolver, 100%
…		…
98	useful) and you want to force your users to use the one and only event	111	useful) and you want to force your users to use the one and only event
99	model, you should I<not> use this module.	112	model, you should I<not> use this module.
100		113
101	=head1 DESCRIPTION	114	=head1 DESCRIPTION
102		115
103	L<AnyEvent> provides an identical interface to multiple event loops. This	116	L<AnyEvent> provides a uniform interface to various event loops. This
104	allows module authors to utilise an event loop without forcing module	117	allows module authors to use event loop functionality without forcing
105	users to use the same event loop (as only a single event loop can coexist	118	module users to use a specific event loop implementation (since more
106	peacefully at any one time).	119	than one event loop cannot coexist peacefully).
107		120
108	The interface itself is vaguely similar, but not identical to the L<Event>	121	The interface itself is vaguely similar, but not identical to the L<Event>
109	module.	122	module.
110		123
111	During the first call of any watcher-creation method, the module tries	124	During the first call of any watcher-creation method, the module tries
112	to detect the currently loaded event loop by probing whether one of the	125	to detect the currently loaded event loop by probing whether one of the
113	following modules is already loaded: L<EV>,	126	following modules is already loaded: L<EV>, L<AnyEvent::Loop>,
114	L<Event>, L<Glib>, L<AnyEvent::Impl::Perl>, L<Tk>, L<Event::Lib>, L<Qt>,	127	L<Event>, L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>. The first one
115	L<POE>. The first one found is used. If none are found, the module tries	128	found is used. If none are detected, the module tries to load the first
116	to load these modules (excluding Tk, Event::Lib, Qt and POE as the pure perl	129	four modules in the order given; but note that if L<EV> is not
117	adaptor should always succeed) in the order given. The first one that can	130	available, the pure-perl L<AnyEvent::Loop> should always work, so
118	be successfully loaded will be used. If, after this, still none could be	131	the other two are not normally tried.
119	found, AnyEvent will fall back to a pure-perl event loop, which is not
120	very efficient, but should work everywhere.
121		132
122	Because AnyEvent first checks for modules that are already loaded, loading	133	Because AnyEvent first checks for modules that are already loaded, loading
123	an event model explicitly before first using AnyEvent will likely make	134	an event model explicitly before first using AnyEvent will likely make
124	that model the default. For example:	135	that model the default. For example:
125		136
…		…
127	use AnyEvent;	138	use AnyEvent;
128		139
129	# .. AnyEvent will likely default to Tk	140	# .. AnyEvent will likely default to Tk
130		141
131	The I<likely> means that, if any module loads another event model and	142	The I<likely> means that, if any module loads another event model and
132	starts using it, all bets are off. Maybe you should tell their authors to	143	starts using it, all bets are off - this case should be very rare though,
133	use AnyEvent so their modules work together with others seamlessly...	144	as very few modules hardcode event loops without announcing this very
		145	loudly.
134		146
135	The pure-perl implementation of AnyEvent is called	147	The pure-perl implementation of AnyEvent is called C<AnyEvent::Loop>. Like
136	C<AnyEvent::Impl::Perl>. Like other event modules you can load it	148	other event modules you can load it explicitly and enjoy the high
137	explicitly and enjoy the high availability of that event loop :)	149	availability of that event loop :)
138		150
139	=head1 WATCHERS	151	=head1 WATCHERS
140		152
141	AnyEvent has the central concept of a I<watcher>, which is an object that	153	AnyEvent has the central concept of a I<watcher>, which is an object that
142	stores relevant data for each kind of event you are waiting for, such as	154	stores relevant data for each kind of event you are waiting for, such as
…		…
147	callback when the event occurs (of course, only when the event model	159	callback when the event occurs (of course, only when the event model
148	is in control).	160	is in control).
149		161
150	Note that B<callbacks must not permanently change global variables>	162	Note that B<callbacks must not permanently change global variables>
151	potentially in use by the event loop (such as C<$_> or C<$[>) and that B<<	163	potentially in use by the event loop (such as C<$_> or C<$[>) and that B<<
152	callbacks must not C<die> >>. The former is good programming practise in	164	callbacks must not C<die> >>. The former is good programming practice in
153	Perl and the latter stems from the fact that exception handling differs	165	Perl and the latter stems from the fact that exception handling differs
154	widely between event loops.	166	widely between event loops.
155		167
156	To disable the watcher you have to destroy it (e.g. by setting the	168	To disable a watcher you have to destroy it (e.g. by setting the
157	variable you store it in to C<undef> or otherwise deleting all references	169	variable you store it in to C<undef> or otherwise deleting all references
158	to it).	170	to it).
159		171
160	All watchers are created by calling a method on the C<AnyEvent> class.	172	All watchers are created by calling a method on the C<AnyEvent> class.
161		173
162	Many watchers either are used with "recursion" (repeating timers for	174	Many watchers either are used with "recursion" (repeating timers for
163	example), or need to refer to their watcher object in other ways.	175	example), or need to refer to their watcher object in other ways.
164		176
165	An any way to achieve that is this pattern:	177	One way to achieve that is this pattern:
166		178
167	my $w; $w = AnyEvent->type (arg => value ..., cb => sub {	179	my $w; $w = AnyEvent->type (arg => value ..., cb => sub {
168	# you can use $w here, for example to undef it	180	# you can use $w here, for example to undef it
169	undef $w;	181	undef $w;
170	});	182	});
…		…
172	Note that C<my $w; $w => combination. This is necessary because in Perl,	184	Note that C<my $w; $w => combination. This is necessary because in Perl,
173	my variables are only visible after the statement in which they are	185	my variables are only visible after the statement in which they are
174	declared.	186	declared.
175		187
176	=head2 I/O WATCHERS	188	=head2 I/O WATCHERS
		189
		190	$w = AnyEvent->io (
		191	fh => <filehandle_or_fileno>,
		192	poll => <"r" or "w">,
		193	cb => <callback>,
		194	);
177		195
178	You can create an I/O watcher by calling the C<< AnyEvent->io >> method	196	You can create an I/O watcher by calling the C<< AnyEvent->io >> method
179	with the following mandatory key-value pairs as arguments:	197	with the following mandatory key-value pairs as arguments:
180		198
181	C<fh> is the Perl I<file handle> (or a naked file descriptor) to watch	199	C<fh> is the Perl I<file handle> (or a naked file descriptor) to watch
…		…
196		214
197	The I/O watcher might use the underlying file descriptor or a copy of it.	215	The I/O watcher might use the underlying file descriptor or a copy of it.
198	You must not close a file handle as long as any watcher is active on the	216	You must not close a file handle as long as any watcher is active on the
199	underlying file descriptor.	217	underlying file descriptor.
200		218
201	Some event loops issue spurious readyness notifications, so you should	219	Some event loops issue spurious readiness notifications, so you should
202	always use non-blocking calls when reading/writing from/to your file	220	always use non-blocking calls when reading/writing from/to your file
203	handles.	221	handles.
204		222
205	Example: wait for readability of STDIN, then read a line and disable the	223	Example: wait for readability of STDIN, then read a line and disable the
206	watcher.	224	watcher.
…		…
211	undef $w;	229	undef $w;
212	});	230	});
213		231
214	=head2 TIME WATCHERS	232	=head2 TIME WATCHERS
215		233
		234	$w = AnyEvent->timer (after => <seconds>, cb => <callback>);
		235
		236	$w = AnyEvent->timer (
		237	after => <fractional_seconds>,
		238	interval => <fractional_seconds>,
		239	cb => <callback>,
		240	);
		241
216	You can create a time watcher by calling the C<< AnyEvent->timer >>	242	You can create a time watcher by calling the C<< AnyEvent->timer >>
217	method with the following mandatory arguments:	243	method with the following mandatory arguments:
218		244
219	C<after> specifies after how many seconds (fractional values are	245	C<after> specifies after how many seconds (fractional values are
220	supported) the callback should be invoked. C<cb> is the callback to invoke	246	supported) the callback should be invoked. C<cb> is the callback to invoke
…		…
222		248
223	Although the callback might get passed parameters, their value and	249	Although the callback might get passed parameters, their value and
224	presence is undefined and you cannot rely on them. Portable AnyEvent	250	presence is undefined and you cannot rely on them. Portable AnyEvent
225	callbacks cannot use arguments passed to time watcher callbacks.	251	callbacks cannot use arguments passed to time watcher callbacks.
226		252
227	The callback will normally be invoked once only. If you specify another	253	The callback will normally be invoked only once. If you specify another
228	parameter, C<interval>, as a strictly positive number (> 0), then the	254	parameter, C<interval>, as a strictly positive number (> 0), then the
229	callback will be invoked regularly at that interval (in fractional	255	callback will be invoked regularly at that interval (in fractional
230	seconds) after the first invocation. If C<interval> is specified with a	256	seconds) after the first invocation. If C<interval> is specified with a
231	false value, then it is treated as if it were missing.	257	false value, then it is treated as if it were not specified at all.
232		258
233	The callback will be rescheduled before invoking the callback, but no	259	The callback will be rescheduled before invoking the callback, but no
234	attempt is done to avoid timer drift in most backends, so the interval is	260	attempt is made to avoid timer drift in most backends, so the interval is
235	only approximate.	261	only approximate.
236		262
237	Example: fire an event after 7.7 seconds.	263	Example: fire an event after 7.7 seconds.
238		264
239	my $w = AnyEvent->timer (after => 7.7, cb => sub {	265	my $w = AnyEvent->timer (after => 7.7, cb => sub {
…		…
257		283
258	While most event loops expect timers to specified in a relative way, they	284	While most event loops expect timers to specified in a relative way, they
259	use absolute time internally. This makes a difference when your clock	285	use absolute time internally. This makes a difference when your clock
260	"jumps", for example, when ntp decides to set your clock backwards from	286	"jumps", for example, when ntp decides to set your clock backwards from
261	the wrong date of 2014-01-01 to 2008-01-01, a watcher that is supposed to	287	the wrong date of 2014-01-01 to 2008-01-01, a watcher that is supposed to
262	fire "after" a second might actually take six years to finally fire.	288	fire "after a second" might actually take six years to finally fire.
263		289
264	AnyEvent cannot compensate for this. The only event loop that is conscious	290	AnyEvent cannot compensate for this. The only event loop that is conscious
265	about these issues is L<EV>, which offers both relative (ev_timer, based	291	of these issues is L<EV>, which offers both relative (ev_timer, based
266	on true relative time) and absolute (ev_periodic, based on wallclock time)	292	on true relative time) and absolute (ev_periodic, based on wallclock time)
267	timers.	293	timers.
268		294
269	AnyEvent always prefers relative timers, if available, matching the	295	AnyEvent always prefers relative timers, if available, matching the
270	AnyEvent API.	296	AnyEvent API.
…		…
292	I<In almost all cases (in all cases if you don't care), this is the	318	I<In almost all cases (in all cases if you don't care), this is the
293	function to call when you want to know the current time.>	319	function to call when you want to know the current time.>
294		320
295	This function is also often faster then C<< AnyEvent->time >>, and	321	This function is also often faster then C<< AnyEvent->time >>, and
296	thus the preferred method if you want some timestamp (for example,	322	thus the preferred method if you want some timestamp (for example,
297	L<AnyEvent::Handle> uses this to update it's activity timeouts).	323	L<AnyEvent::Handle> uses this to update its activity timeouts).
298		324
299	The rest of this section is only of relevance if you try to be very exact	325	The rest of this section is only of relevance if you try to be very exact
300	with your timing, you can skip it without bad conscience.	326	with your timing; you can skip it without a bad conscience.
301		327
302	For a practical example of when these times differ, consider L<Event::Lib>	328	For a practical example of when these times differ, consider L<Event::Lib>
303	and L<EV> and the following set-up:	329	and L<EV> and the following set-up:
304		330
305	The event loop is running and has just invoked one of your callback at	331	The event loop is running and has just invoked one of your callbacks at
306	time=500 (assume no other callbacks delay processing). In your callback,	332	time=500 (assume no other callbacks delay processing). In your callback,
307	you wait a second by executing C<sleep 1> (blocking the process for a	333	you wait a second by executing C<sleep 1> (blocking the process for a
308	second) and then (at time=501) you create a relative timer that fires	334	second) and then (at time=501) you create a relative timer that fires
309	after three seconds.	335	after three seconds.
310		336
…		…
330	difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into	356	difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into
331	account.	357	account.
332		358
333	=item AnyEvent->now_update	359	=item AnyEvent->now_update
334		360
335	Some event loops (such as L<EV> or L<AnyEvent::Impl::Perl>) cache	361	Some event loops (such as L<EV> or L<AnyEvent::Loop>) cache the current
336	the current time for each loop iteration (see the discussion of L<<	362	time for each loop iteration (see the discussion of L<< AnyEvent->now >>,
337	AnyEvent->now >>, above).	363	above).
338		364
339	When a callback runs for a long time (or when the process sleeps), then	365	When a callback runs for a long time (or when the process sleeps), then
340	this "current" time will differ substantially from the real time, which	366	this "current" time will differ substantially from the real time, which
341	might affect timers and time-outs.	367	might affect timers and time-outs.
342		368
343	When this is the case, you can call this method, which will update the	369	When this is the case, you can call this method, which will update the
344	event loop's idea of "current time".	370	event loop's idea of "current time".
345		371
		372	A typical example would be a script in a web server (e.g. C<mod_perl>) -
		373	when mod_perl executes the script, then the event loop will have the wrong
		374	idea about the "current time" (being potentially far in the past, when the
		375	script ran the last time). In that case you should arrange a call to C<<
		376	AnyEvent->now_update >> each time the web server process wakes up again
		377	(e.g. at the start of your script, or in a handler).
		378
346	Note that updating the time I<might> cause some events to be handled.	379	Note that updating the time I<might> cause some events to be handled.
347		380
348	=back	381	=back
349		382
350	=head2 SIGNAL WATCHERS	383	=head2 SIGNAL WATCHERS
		384
		385	$w = AnyEvent->signal (signal => <uppercase_signal_name>, cb => <callback>);
351		386
352	You can watch for signals using a signal watcher, C<signal> is the signal	387	You can watch for signals using a signal watcher, C<signal> is the signal
353	I<name> in uppercase and without any C<SIG> prefix, C<cb> is the Perl	388	I<name> in uppercase and without any C<SIG> prefix, C<cb> is the Perl
354	callback to be invoked whenever a signal occurs.	389	callback to be invoked whenever a signal occurs.
355		390
…		…
368		403
369	This watcher might use C<%SIG> (depending on the event loop used),	404	This watcher might use C<%SIG> (depending on the event loop used),
370	so programs overwriting those signals directly will likely not work	405	so programs overwriting those signals directly will likely not work
371	correctly.	406	correctly.
372		407
373	Also note that many event loops (e.g. Glib, Tk, Qt, IO::Async) do not
374	support attaching callbacks to signals, which is a pity, as you cannot do
375	race-free signal handling in perl. AnyEvent will try to do it's best, but
376	in some cases, signals will be delayed. The maximum time a signal might
377	be delayed is specified in C<$AnyEvent::MAX_SIGNAL_LATENCY> (default: 10
378	seconds). This variable can be changed only before the first signal
379	watcher is created, and should be left alone otherwise. Higher values
380	will cause fewer spurious wake-ups, which is better for power and CPU
381	saving. All these problems can be avoided by installing the optional
382	L<Async::Interrupt> module.
383
384	Example: exit on SIGINT	408	Example: exit on SIGINT
385		409
386	my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });	410	my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });
387		411
		412	=head3 Restart Behaviour
		413
		414	While restart behaviour is up to the event loop implementation, most will
		415	not restart syscalls (that includes L<Async::Interrupt> and AnyEvent's
		416	pure perl implementation).
		417
		418	=head3 Safe/Unsafe Signals
		419
		420	Perl signals can be either "safe" (synchronous to opcode handling)
		421	or "unsafe" (asynchronous) - the former might delay signal delivery
		422	indefinitely, the latter might corrupt your memory.
		423
		424	AnyEvent signal handlers are, in addition, synchronous to the event loop,
		425	i.e. they will not interrupt your running perl program but will only be
		426	called as part of the normal event handling (just like timer, I/O etc.
		427	callbacks, too).
		428
		429	=head3 Signal Races, Delays and Workarounds
		430
		431	Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support
		432	attaching callbacks to signals in a generic way, which is a pity,
		433	as you cannot do race-free signal handling in perl, requiring
		434	C libraries for this. AnyEvent will try to do its best, which
		435	means in some cases, signals will be delayed. The maximum time
		436	a signal might be delayed is 10 seconds by default, but can
		437	be overriden via C<$ENV{PERL_ANYEVENT_MAX_SIGNAL_LATENCY}> or
		438	C<$AnyEvent::MAX_SIGNAL_LATENCY> - see the L<ENVIRONMENT VARIABLES>
		439	section for details.
		440
		441	All these problems can be avoided by installing the optional
		442	L<Async::Interrupt> module, which works with most event loops. It will not
		443	work with inherently broken event loops such as L<Event> or L<Event::Lib>
		444	(and not with L<POE> currently). For those, you just have to suffer the
		445	delays.
		446
388	=head2 CHILD PROCESS WATCHERS	447	=head2 CHILD PROCESS WATCHERS
389		448
		449	$w = AnyEvent->child (pid => <process id>, cb => <callback>);
		450
390	You can also watch on a child process exit and catch its exit status.	451	You can also watch for a child process exit and catch its exit status.
391		452
392	The child process is specified by the C<pid> argument (if set to C<0>, it	453	The child process is specified by the C<pid> argument (on some backends,
393	watches for any child process exit). The watcher will triggered only when	454	using C<0> watches for any child process exit, on others this will
394	the child process has finished and an exit status is available, not on	455	croak). The watcher will be triggered only when the child process has
395	any trace events (stopped/continued).	456	finished and an exit status is available, not on any trace events
		457	(stopped/continued).
396		458
397	The callback will be called with the pid and exit status (as returned by	459	The callback will be called with the pid and exit status (as returned by
398	waitpid), so unlike other watcher types, you I<can> rely on child watcher	460	waitpid), so unlike other watcher types, you I<can> rely on child watcher
399	callback arguments.	461	callback arguments.
400		462
…		…
418	thing in an AnyEvent program, you I<have> to create at least one	480	thing in an AnyEvent program, you I<have> to create at least one
419	watcher before you C<fork> the child (alternatively, you can call	481	watcher before you C<fork> the child (alternatively, you can call
420	C<AnyEvent::detect>).	482	C<AnyEvent::detect>).
421		483
422	As most event loops do not support waiting for child events, they will be	484	As most event loops do not support waiting for child events, they will be
423	emulated by AnyEvent in most cases, in which the latency and race problems	485	emulated by AnyEvent in most cases, in which case the latency and race
424	mentioned in the description of signal watchers apply.	486	problems mentioned in the description of signal watchers apply.
425		487
426	Example: fork a process and wait for it	488	Example: fork a process and wait for it
427		489
428	my $done = AnyEvent->condvar;	490	my $done = AnyEvent->condvar;
429		491
…		…
441	# do something else, then wait for process exit	503	# do something else, then wait for process exit
442	$done->recv;	504	$done->recv;
443		505
444	=head2 IDLE WATCHERS	506	=head2 IDLE WATCHERS
445		507
446	Sometimes there is a need to do something, but it is not so important	508	$w = AnyEvent->idle (cb => <callback>);
447	to do it instantly, but only when there is nothing better to do. This
448	"nothing better to do" is usually defined to be "no other events need
449	attention by the event loop".
450		509
451	Idle watchers ideally get invoked when the event loop has nothing	510	This will repeatedly invoke the callback after the process becomes idle,
452	better to do, just before it would block the process to wait for new	511	until either the watcher is destroyed or new events have been detected.
453	events. Instead of blocking, the idle watcher is invoked.
454		512
455	Most event loops unfortunately do not really support idle watchers (only	513	Idle watchers are useful when there is a need to do something, but it
		514	is not so important (or wise) to do it instantly. The callback will be
		515	invoked only when there is "nothing better to do", which is usually
		516	defined as "all outstanding events have been handled and no new events
		517	have been detected". That means that idle watchers ideally get invoked
		518	when the event loop has just polled for new events but none have been
		519	detected. Instead of blocking to wait for more events, the idle watchers
		520	will be invoked.
		521
		522	Unfortunately, most event loops do not really support idle watchers (only
456	EV, Event and Glib do it in a usable fashion) - for the rest, AnyEvent	523	EV, Event and Glib do it in a usable fashion) - for the rest, AnyEvent
457	will simply call the callback "from time to time".	524	will simply call the callback "from time to time".
458		525
459	Example: read lines from STDIN, but only process them when the	526	Example: read lines from STDIN, but only process them when the
460	program is otherwise idle:	527	program is otherwise idle:
…		…
476	});	543	});
477	});	544	});
478		545
479	=head2 CONDITION VARIABLES	546	=head2 CONDITION VARIABLES
480		547
		548	$cv = AnyEvent->condvar;
		549
		550	$cv->send (<list>);
		551	my @res = $cv->recv;
		552
481	If you are familiar with some event loops you will know that all of them	553	If you are familiar with some event loops you will know that all of them
482	require you to run some blocking "loop", "run" or similar function that	554	require you to run some blocking "loop", "run" or similar function that
483	will actively watch for new events and call your callbacks.	555	will actively watch for new events and call your callbacks.
484		556
485	AnyEvent is slightly different: it expects somebody else to run the event	557	AnyEvent is slightly different: it expects somebody else to run the event
486	loop and will only block when necessary (usually when told by the user).	558	loop and will only block when necessary (usually when told by the user).
487		559
488	The instrument to do that is called a "condition variable", so called	560	The tool to do that is called a "condition variable", so called because
489	because they represent a condition that must become true.	561	they represent a condition that must become true.
490		562
491	Now is probably a good time to look at the examples further below.	563	Now is probably a good time to look at the examples further below.
492		564
493	Condition variables can be created by calling the C<< AnyEvent->condvar	565	Condition variables can be created by calling the C<< AnyEvent->condvar
494	>> method, usually without arguments. The only argument pair allowed is	566	>> method, usually without arguments. The only argument pair allowed is
…		…
499	After creation, the condition variable is "false" until it becomes "true"	571	After creation, the condition variable is "false" until it becomes "true"
500	by calling the C<send> method (or calling the condition variable as if it	572	by calling the C<send> method (or calling the condition variable as if it
501	were a callback, read about the caveats in the description for the C<<	573	were a callback, read about the caveats in the description for the C<<
502	->send >> method).	574	->send >> method).
503		575
504	Condition variables are similar to callbacks, except that you can	576	Since condition variables are the most complex part of the AnyEvent API, here are
505	optionally wait for them. They can also be called merge points - points	577	some different mental models of what they are - pick the ones you can connect to:
506	in time where multiple outstanding events have been processed. And yet	578
507	another way to call them is transactions - each condition variable can be	579	=over 4
508	used to represent a transaction, which finishes at some point and delivers	580
509	a result.	581	=item * Condition variables are like callbacks - you can call them (and pass them instead
		582	of callbacks). Unlike callbacks however, you can also wait for them to be called.
		583
		584	=item * Condition variables are signals - one side can emit or send them,
		585	the other side can wait for them, or install a handler that is called when
		586	the signal fires.
		587
		588	=item * Condition variables are like "Merge Points" - points in your program
		589	where you merge multiple independent results/control flows into one.
		590
		591	=item * Condition variables represent a transaction - functions that start
		592	some kind of transaction can return them, leaving the caller the choice
		593	between waiting in a blocking fashion, or setting a callback.
		594
		595	=item * Condition variables represent future values, or promises to deliver
		596	some result, long before the result is available.
		597
		598	=back
510		599
511	Condition variables are very useful to signal that something has finished,	600	Condition variables are very useful to signal that something has finished,
512	for example, if you write a module that does asynchronous http requests,	601	for example, if you write a module that does asynchronous http requests,
513	then a condition variable would be the ideal candidate to signal the	602	then a condition variable would be the ideal candidate to signal the
514	availability of results. The user can either act when the callback is	603	availability of results. The user can either act when the callback is
…		…
527		616
528	Condition variables are represented by hash refs in perl, and the keys	617	Condition variables are represented by hash refs in perl, and the keys
529	used by AnyEvent itself are all named C<_ae_XXX> to make subclassing	618	used by AnyEvent itself are all named C<_ae_XXX> to make subclassing
530	easy (it is often useful to build your own transaction class on top of	619	easy (it is often useful to build your own transaction class on top of
531	AnyEvent). To subclass, use C<AnyEvent::CondVar> as base class and call	620	AnyEvent). To subclass, use C<AnyEvent::CondVar> as base class and call
532	it's C<new> method in your own C<new> method.	621	its C<new> method in your own C<new> method.
533		622
534	There are two "sides" to a condition variable - the "producer side" which	623	There are two "sides" to a condition variable - the "producer side" which
535	eventually calls C<< -> send >>, and the "consumer side", which waits	624	eventually calls C<< -> send >>, and the "consumer side", which waits
536	for the send to occur.	625	for the send to occur.
537		626
538	Example: wait for a timer.	627	Example: wait for a timer.
539		628
540	# wait till the result is ready	629	# condition: "wait till the timer is fired"
541	my $result_ready = AnyEvent->condvar;	630	my $timer_fired = AnyEvent->condvar;
542		631
543	# do something such as adding a timer	632	# create the timer - we could wait for, say
544	# or socket watcher the calls $result_ready->send	633	# a handle becomign ready, or even an
545	# when the "result" is ready.	634	# AnyEvent::HTTP request to finish, but
546	# in this case, we simply use a timer:	635	# in this case, we simply use a timer:
547	my $w = AnyEvent->timer (	636	my $w = AnyEvent->timer (
548	after => 1,	637	after => 1,
549	cb => sub { $result_ready->send },	638	cb => sub { $timer_fired->send },
550	);	639	);
551		640
552	# this "blocks" (while handling events) till the callback	641	# this "blocks" (while handling events) till the callback
553	# calls -<send	642	# calls ->send
554	$result_ready->recv;	643	$timer_fired->recv;
555		644
556	Example: wait for a timer, but take advantage of the fact that condition	645	Example: wait for a timer, but take advantage of the fact that condition
557	variables are also callable directly.	646	variables are also callable directly.
558		647
559	my $done = AnyEvent->condvar;	648	my $done = AnyEvent->condvar;
…		…
602	they were a code reference). Calling them directly is the same as calling	691	they were a code reference). Calling them directly is the same as calling
603	C<send>.	692	C<send>.
604		693
605	=item $cv->croak ($error)	694	=item $cv->croak ($error)
606		695
607	Similar to send, but causes all call's to C<< ->recv >> to invoke	696	Similar to send, but causes all calls to C<< ->recv >> to invoke
608	C<Carp::croak> with the given error message/object/scalar.	697	C<Carp::croak> with the given error message/object/scalar.
609		698
610	This can be used to signal any errors to the condition variable	699	This can be used to signal any errors to the condition variable
611	user/consumer. Doing it this way instead of calling C<croak> directly	700	user/consumer. Doing it this way instead of calling C<croak> directly
612	delays the error detetcion, but has the overwhelmign advantage that it	701	delays the error detection, but has the overwhelming advantage that it
613	diagnoses the error at the place where the result is expected, and not	702	diagnoses the error at the place where the result is expected, and not
614	deep in some event clalback without connection to the actual code causing	703	deep in some event callback with no connection to the actual code causing
615	the problem.	704	the problem.
616		705
617	=item $cv->begin ([group callback])	706	=item $cv->begin ([group callback])
618		707
619	=item $cv->end	708	=item $cv->end
…		…
622	one. For example, a function that pings many hosts in parallel might want	711	one. For example, a function that pings many hosts in parallel might want
623	to use a condition variable for the whole process.	712	to use a condition variable for the whole process.
624		713
625	Every call to C<< ->begin >> will increment a counter, and every call to	714	Every call to C<< ->begin >> will increment a counter, and every call to
626	C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end	715	C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end
627	>>, the (last) callback passed to C<begin> will be executed. That callback	716	>>, the (last) callback passed to C<begin> will be executed, passing the
628	is I<supposed> to call C<< ->send >>, but that is not required. If no	717	condvar as first argument. That callback is I<supposed> to call C<< ->send
629	callback was set, C<send> will be called without any arguments.	718	>>, but that is not required. If no group callback was set, C<send> will
		719	be called without any arguments.
630		720
631	You can think of C<< $cv->send >> giving you an OR condition (one call	721	You can think of C<< $cv->send >> giving you an OR condition (one call
632	sends), while C<< $cv->begin >> and C<< $cv->end >> giving you an AND	722	sends), while C<< $cv->begin >> and C<< $cv->end >> giving you an AND
633	condition (all C<begin> calls must be C<end>'ed before the condvar sends).	723	condition (all C<begin> calls must be C<end>'ed before the condvar sends).
634		724
…		…
656	one call to C<begin>, so the condvar waits for all calls to C<end> before	746	one call to C<begin>, so the condvar waits for all calls to C<end> before
657	sending.	747	sending.
658		748
659	The ping example mentioned above is slightly more complicated, as the	749	The ping example mentioned above is slightly more complicated, as the
660	there are results to be passwd back, and the number of tasks that are	750	there are results to be passwd back, and the number of tasks that are
661	begung can potentially be zero:	751	begun can potentially be zero:
662		752
663	my $cv = AnyEvent->condvar;	753	my $cv = AnyEvent->condvar;
664		754
665	my %result;	755	my %result;
666	$cv->begin (sub { $cv->send (\%result) });	756	$cv->begin (sub { shift->send (\%result) });
667		757
668	for my $host (@list_of_hosts) {	758	for my $host (@list_of_hosts) {
669	$cv->begin;	759	$cv->begin;
670	ping_host_then_call_callback $host, sub {	760	ping_host_then_call_callback $host, sub {
671	$result{$host} = ...;	761	$result{$host} = ...;
…		…
687	to be called once the counter reaches C<0>, and second, it ensures that	777	to be called once the counter reaches C<0>, and second, it ensures that
688	C<send> is called even when C<no> hosts are being pinged (the loop	778	C<send> is called even when C<no> hosts are being pinged (the loop
689	doesn't execute once).	779	doesn't execute once).
690		780
691	This is the general pattern when you "fan out" into multiple (but	781	This is the general pattern when you "fan out" into multiple (but
692	potentially none) subrequests: use an outer C<begin>/C<end> pair to set	782	potentially zero) subrequests: use an outer C<begin>/C<end> pair to set
693	the callback and ensure C<end> is called at least once, and then, for each	783	the callback and ensure C<end> is called at least once, and then, for each
694	subrequest you start, call C<begin> and for each subrequest you finish,	784	subrequest you start, call C<begin> and for each subrequest you finish,
695	call C<end>.	785	call C<end>.
696		786
697	=back	787	=back
…		…
704	=over 4	794	=over 4
705		795
706	=item $cv->recv	796	=item $cv->recv
707		797
708	Wait (blocking if necessary) until the C<< ->send >> or C<< ->croak	798	Wait (blocking if necessary) until the C<< ->send >> or C<< ->croak
709	>> methods have been called on c<$cv>, while servicing other watchers	799	>> methods have been called on C<$cv>, while servicing other watchers
710	normally.	800	normally.
711		801
712	You can only wait once on a condition - additional calls are valid but	802	You can only wait once on a condition - additional calls are valid but
713	will return immediately.	803	will return immediately.
714		804
…		…
731	caller decide whether the call will block or not (for example, by coupling	821	caller decide whether the call will block or not (for example, by coupling
732	condition variables with some kind of request results and supporting	822	condition variables with some kind of request results and supporting
733	callbacks so the caller knows that getting the result will not block,	823	callbacks so the caller knows that getting the result will not block,
734	while still supporting blocking waits if the caller so desires).	824	while still supporting blocking waits if the caller so desires).
735		825
736	You can ensure that C<< -recv >> never blocks by setting a callback and	826	You can ensure that C<< ->recv >> never blocks by setting a callback and
737	only calling C<< ->recv >> from within that callback (or at a later	827	only calling C<< ->recv >> from within that callback (or at a later
738	time). This will work even when the event loop does not support blocking	828	time). This will work even when the event loop does not support blocking
739	waits otherwise.	829	waits otherwise.
740		830
741	=item $bool = $cv->ready	831	=item $bool = $cv->ready
…		…
747		837
748	This is a mutator function that returns the callback set and optionally	838	This is a mutator function that returns the callback set and optionally
749	replaces it before doing so.	839	replaces it before doing so.
750		840
751	The callback will be called when the condition becomes "true", i.e. when	841	The callback will be called when the condition becomes "true", i.e. when
752	C<send> or C<croak> are called, with the only argument being the condition	842	C<send> or C<croak> are called, with the only argument being the
753	variable itself. Calling C<recv> inside the callback or at any later time	843	condition variable itself. If the condition is already true, the
754	is guaranteed not to block.	844	callback is called immediately when it is set. Calling C<recv> inside
		845	the callback or at any later time is guaranteed not to block.
755		846
756	=back	847	=back
757		848
758	=head1 SUPPORTED EVENT LOOPS/BACKENDS	849	=head1 SUPPORTED EVENT LOOPS/BACKENDS
759		850
…		…
762	=over 4	853	=over 4
763		854
764	=item Backends that are autoprobed when no other event loop can be found.	855	=item Backends that are autoprobed when no other event loop can be found.
765		856
766	EV is the preferred backend when no other event loop seems to be in	857	EV is the preferred backend when no other event loop seems to be in
767	use. If EV is not installed, then AnyEvent will try Event, and, failing	858	use. If EV is not installed, then AnyEvent will fall back to its own
768	that, will fall back to its own pure-perl implementation, which is	859	pure-perl implementation, which is available everywhere as it comes with
769	available everywhere as it comes with AnyEvent itself.	860	AnyEvent itself.
770		861
771	AnyEvent::Impl::EV based on EV (interface to libev, best choice).	862	AnyEvent::Impl::EV based on EV (interface to libev, best choice).
772	AnyEvent::Impl::Event based on Event, very stable, few glitches.
773	AnyEvent::Impl::Perl pure-perl implementation, fast and portable.	863	AnyEvent::Impl::Perl pure-perl AnyEvent::Loop, fast and portable.
774		864
775	=item Backends that are transparently being picked up when they are used.	865	=item Backends that are transparently being picked up when they are used.
776		866
777	These will be used when they are currently loaded when the first watcher	867	These will be used if they are already loaded when the first watcher
778	is created, in which case it is assumed that the application is using	868	is created, in which case it is assumed that the application is using
779	them. This means that AnyEvent will automatically pick the right backend	869	them. This means that AnyEvent will automatically pick the right backend
780	when the main program loads an event module before anything starts to	870	when the main program loads an event module before anything starts to
781	create watchers. Nothing special needs to be done by the main program.	871	create watchers. Nothing special needs to be done by the main program.
782		872
		873	AnyEvent::Impl::Event based on Event, very stable, few glitches.
783	AnyEvent::Impl::Glib based on Glib, slow but very stable.	874	AnyEvent::Impl::Glib based on Glib, slow but very stable.
784	AnyEvent::Impl::Tk based on Tk, very broken.	875	AnyEvent::Impl::Tk based on Tk, very broken.
785	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.	876	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
786	AnyEvent::Impl::POE based on POE, very slow, some limitations.	877	AnyEvent::Impl::POE based on POE, very slow, some limitations.
		878	AnyEvent::Impl::Irssi used when running within irssi.
		879	AnyEvent::Impl::IOAsync based on IO::Async.
		880	AnyEvent::Impl::Cocoa based on Cocoa::EventLoop.
		881	AnyEvent::Impl::FLTK based on FLTK (fltk 2 binding).
787		882
788	=item Backends with special needs.	883	=item Backends with special needs.
789		884
790	Qt requires the Qt::Application to be instantiated first, but will	885	Qt requires the Qt::Application to be instantiated first, but will
791	otherwise be picked up automatically. As long as the main program	886	otherwise be picked up automatically. As long as the main program
792	instantiates the application before any AnyEvent watchers are created,	887	instantiates the application before any AnyEvent watchers are created,
793	everything should just work.	888	everything should just work.
794		889
795	AnyEvent::Impl::Qt based on Qt.	890	AnyEvent::Impl::Qt based on Qt.
796		891
797	Support for IO::Async can only be partial, as it is too broken and
798	architecturally limited to even support the AnyEvent API. It also
799	is the only event loop that needs the loop to be set explicitly, so
800	it can only be used by a main program knowing about AnyEvent. See
801	L<AnyEvent::Impl::Async> for the gory details.
802
803	AnyEvent::Impl::IOAsync based on IO::Async, cannot be autoprobed.
804
805	=item Event loops that are indirectly supported via other backends.	892	=item Event loops that are indirectly supported via other backends.
806		893
807	Some event loops can be supported via other modules:	894	Some event loops can be supported via other modules:
808		895
809	There is no direct support for WxWidgets (L<Wx>) or L<Prima>.	896	There is no direct support for WxWidgets (L<Wx>) or L<Prima>.
…		…
834	Contains C<undef> until the first watcher is being created, before the	921	Contains C<undef> until the first watcher is being created, before the
835	backend has been autodetected.	922	backend has been autodetected.
836		923
837	Afterwards it contains the event model that is being used, which is the	924	Afterwards it contains the event model that is being used, which is the
838	name of the Perl class implementing the model. This class is usually one	925	name of the Perl class implementing the model. This class is usually one
839	of the C<AnyEvent::Impl:xxx> modules, but can be any other class in the	926	of the C<AnyEvent::Impl::xxx> modules, but can be any other class in the
840	case AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode> it	927	case AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode> it
841	will be C<urxvt::anyevent>).	928	will be C<urxvt::anyevent>).
842		929
843	=item AnyEvent::detect	930	=item AnyEvent::detect
844		931
845	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model	932	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model
846	if necessary. You should only call this function right before you would	933	if necessary. You should only call this function right before you would
847	have created an AnyEvent watcher anyway, that is, as late as possible at	934	have created an AnyEvent watcher anyway, that is, as late as possible at
848	runtime, and not e.g. while initialising of your module.	935	runtime, and not e.g. during initialisation of your module.
		936
		937	The effect of calling this function is as if a watcher had been created
		938	(specifically, actions that happen "when the first watcher is created"
		939	happen when calling detetc as well).
849		940
850	If you need to do some initialisation before AnyEvent watchers are	941	If you need to do some initialisation before AnyEvent watchers are
851	created, use C<post_detect>.	942	created, use C<post_detect>.
852		943
853	=item $guard = AnyEvent::post_detect { BLOCK }	944	=item $guard = AnyEvent::post_detect { BLOCK }
854		945
855	Arranges for the code block to be executed as soon as the event model is	946	Arranges for the code block to be executed as soon as the event model is
856	autodetected (or immediately if this has already happened).	947	autodetected (or immediately if that has already happened).
857		948
858	The block will be executed I<after> the actual backend has been detected	949	The block will be executed I<after> the actual backend has been detected
859	(C<$AnyEvent::MODEL> is set), but I<before> any watchers have been	950	(C<$AnyEvent::MODEL> is set), but I<before> any watchers have been
860	created, so it is possible to e.g. patch C<@AnyEvent::ISA> or do	951	created, so it is possible to e.g. patch C<@AnyEvent::ISA> or do
861	other initialisations - see the sources of L<AnyEvent::Strict> or	952	other initialisations - see the sources of L<AnyEvent::Strict> or
…		…
865	event module detection too early, for example, L<AnyEvent::AIO> creates	956	event module detection too early, for example, L<AnyEvent::AIO> creates
866	and installs the global L<IO::AIO> watcher in a C<post_detect> block to	957	and installs the global L<IO::AIO> watcher in a C<post_detect> block to
867	avoid autodetecting the event module at load time.	958	avoid autodetecting the event module at load time.
868		959
869	If called in scalar or list context, then it creates and returns an object	960	If called in scalar or list context, then it creates and returns an object
870	that automatically removes the callback again when it is destroyed. See	961	that automatically removes the callback again when it is destroyed (or
		962	C<undef> when the hook was immediately executed). See L<AnyEvent::AIO> for
871	L<Coro::BDB> for a case where this is useful.	963	a case where this is useful.
		964
		965	Example: Create a watcher for the IO::AIO module and store it in
		966	C<$WATCHER>, but do so only do so after the event loop is initialised.
		967
		968	our WATCHER;
		969
		970	my $guard = AnyEvent::post_detect {
		971	$WATCHER = AnyEvent->io (fh => IO::AIO::poll_fileno, poll => 'r', cb => \&IO::AIO::poll_cb);
		972	};
		973
		974	# the ||= is important in case post_detect immediately runs the block,
		975	# as to not clobber the newly-created watcher. assigning both watcher and
		976	# post_detect guard to the same variable has the advantage of users being
		977	# able to just C<undef $WATCHER> if the watcher causes them grief.
		978
		979	$WATCHER ||= $guard;
872		980
873	=item @AnyEvent::post_detect	981	=item @AnyEvent::post_detect
874		982
875	If there are any code references in this array (you can C<push> to it	983	If there are any code references in this array (you can C<push> to it
876	before or after loading AnyEvent), then they will called directly after	984	before or after loading AnyEvent), then they will be called directly
877	the event loop has been chosen.	985	after the event loop has been chosen.
878		986
879	You should check C<$AnyEvent::MODEL> before adding to this array, though:	987	You should check C<$AnyEvent::MODEL> before adding to this array, though:
880	if it is defined then the event loop has already been detected, and the	988	if it is defined then the event loop has already been detected, and the
881	array will be ignored.	989	array will be ignored.
882		990
883	Best use C<AnyEvent::post_detect { BLOCK }> when your application allows	991	Best use C<AnyEvent::post_detect { BLOCK }> when your application allows
884	it,as it takes care of these details.	992	it, as it takes care of these details.
885		993
886	This variable is mainly useful for modules that can do something useful	994	This variable is mainly useful for modules that can do something useful
887	when AnyEvent is used and thus want to know when it is initialised, but do	995	when AnyEvent is used and thus want to know when it is initialised, but do
888	not need to even load it by default. This array provides the means to hook	996	not need to even load it by default. This array provides the means to hook
889	into AnyEvent passively, without loading it.	997	into AnyEvent passively, without loading it.
890		998
		999	Example: To load Coro::AnyEvent whenever Coro and AnyEvent are used
		1000	together, you could put this into Coro (this is the actual code used by
		1001	Coro to accomplish this):
		1002
		1003	if (defined $AnyEvent::MODEL) {
		1004	# AnyEvent already initialised, so load Coro::AnyEvent
		1005	require Coro::AnyEvent;
		1006	} else {
		1007	# AnyEvent not yet initialised, so make sure to load Coro::AnyEvent
		1008	# as soon as it is
		1009	push @AnyEvent::post_detect, sub { require Coro::AnyEvent };
		1010	}
		1011
		1012	=item AnyEvent::postpone { BLOCK }
		1013
		1014	Arranges for the block to be executed as soon as possible, but not before
		1015	the call itself returns. In practise, the block will be executed just
		1016	before the event loop polls for new events, or shortly afterwards.
		1017
		1018	This function never returns anything (to make the C<return postpone { ...
		1019	}> idiom more useful.
		1020
		1021	To understand the usefulness of this function, consider a function that
		1022	asynchronously does something for you and returns some transaction
		1023	object or guard to let you cancel the operation. For example,
		1024	C<AnyEvent::Socket::tcp_connect>:
		1025
		1026	# start a conenction attempt unless one is active
		1027	$self->{connect_guard} ||= AnyEvent::Socket::tcp_connect "www.example.net", 80, sub {
		1028	delete $self->{connect_guard};
		1029	...
		1030	};
		1031
		1032	Imagine that this function could instantly call the callback, for
		1033	example, because it detects an obvious error such as a negative port
		1034	number. Invoking the callback before the function returns causes problems
		1035	however: the callback will be called and will try to delete the guard
		1036	object. But since the function hasn't returned yet, there is nothing to
		1037	delete. When the function eventually returns it will assign the guard
		1038	object to C<< $self->{connect_guard} >>, where it will likely never be
		1039	deleted, so the program thinks it is still trying to connect.
		1040
		1041	This is where C<AnyEvent::postpone> should be used. Instead of calling the
		1042	callback directly on error:
		1043
		1044	$cb->(undef), return # signal error to callback, BAD!
		1045	if $some_error_condition;
		1046
		1047	It should use C<postpone>:
		1048
		1049	AnyEvent::postpone { $cb->(undef) }, return # signal error to callback, later
		1050	if $some_error_condition;
		1051
		1052	=item AnyEvent::log $level, $msg[, @args]
		1053
		1054	Log the given C<$msg> at the given C<$level>.
		1055
		1056	If L<AnyEvent::Log> is not loaded then this function makes a simple test
		1057	to see whether the message will be logged. If the test succeeds it will
		1058	load AnyEvent::Log and call C<AnyEvent::Log::log> - consequently, look at
		1059	the L<AnyEvent::Log> documentation for details.
		1060
		1061	If the test fails it will simply return. Right now this happens when a
		1062	numerical loglevel is used and it is larger than the level specified via
		1063	C<$ENV{PERL_ANYEVENT_VERBOSE}>.
		1064
		1065	If you want to sprinkle loads of logging calls around your code, consider
		1066	creating a logger callback with the C<AnyEvent::Log::logger> function,
		1067	which can reduce typing, codesize and can reduce the logging overhead
		1068	enourmously.
		1069
891	=back	1070	=back
892		1071
893	=head1 WHAT TO DO IN A MODULE	1072	=head1 WHAT TO DO IN A MODULE
894		1073
895	As a module author, you should C<use AnyEvent> and call AnyEvent methods	1074	As a module author, you should C<use AnyEvent> and call AnyEvent methods
…		…
905	because it will stall the whole program, and the whole point of using	1084	because it will stall the whole program, and the whole point of using
906	events is to stay interactive.	1085	events is to stay interactive.
907		1086
908	It is fine, however, to call C<< ->recv >> when the user of your module	1087	It is fine, however, to call C<< ->recv >> when the user of your module
909	requests it (i.e. if you create a http request object ad have a method	1088	requests it (i.e. if you create a http request object ad have a method
910	called C<results> that returns the results, it should call C<< ->recv >>	1089	called C<results> that returns the results, it may call C<< ->recv >>
911	freely, as the user of your module knows what she is doing. always).	1090	freely, as the user of your module knows what she is doing. Always).
912		1091
913	=head1 WHAT TO DO IN THE MAIN PROGRAM	1092	=head1 WHAT TO DO IN THE MAIN PROGRAM
914		1093
915	There will always be a single main program - the only place that should	1094	There will always be a single main program - the only place that should
916	dictate which event model to use.	1095	dictate which event model to use.
917		1096
918	If it doesn't care, it can just "use AnyEvent" and use it itself, or not	1097	If the program is not event-based, it need not do anything special, even
919	do anything special (it does not need to be event-based) and let AnyEvent	1098	when it depends on a module that uses an AnyEvent. If the program itself
920	decide which implementation to chose if some module relies on it.	1099	uses AnyEvent, but does not care which event loop is used, all it needs
		1100	to do is C<use AnyEvent>. In either case, AnyEvent will choose the best
		1101	available loop implementation.
921		1102
922	If the main program relies on a specific event model - for example, in	1103	If the main program relies on a specific event model - for example, in
923	Gtk2 programs you have to rely on the Glib module - you should load the	1104	Gtk2 programs you have to rely on the Glib module - you should load the
924	event module before loading AnyEvent or any module that uses it: generally	1105	event module before loading AnyEvent or any module that uses it: generally
925	speaking, you should load it as early as possible. The reason is that	1106	speaking, you should load it as early as possible. The reason is that
926	modules might create watchers when they are loaded, and AnyEvent will	1107	modules might create watchers when they are loaded, and AnyEvent will
927	decide on the event model to use as soon as it creates watchers, and it	1108	decide on the event model to use as soon as it creates watchers, and it
928	might chose the wrong one unless you load the correct one yourself.	1109	might choose the wrong one unless you load the correct one yourself.
929		1110
930	You can chose to use a pure-perl implementation by loading the	1111	You can chose to use a pure-perl implementation by loading the
931	C<AnyEvent::Impl::Perl> module, which gives you similar behaviour	1112	C<AnyEvent::Loop> module, which gives you similar behaviour
932	everywhere, but letting AnyEvent chose the model is generally better.	1113	everywhere, but letting AnyEvent chose the model is generally better.
933		1114
934	=head2 MAINLOOP EMULATION	1115	=head2 MAINLOOP EMULATION
935		1116
936	Sometimes (often for short test scripts, or even standalone programs who	1117	Sometimes (often for short test scripts, or even standalone programs who
…		…
949		1130
950		1131
951	=head1 OTHER MODULES	1132	=head1 OTHER MODULES
952		1133
953	The following is a non-exhaustive list of additional modules that use	1134	The following is a non-exhaustive list of additional modules that use
954	AnyEvent as a client and can therefore be mixed easily with other AnyEvent	1135	AnyEvent as a client and can therefore be mixed easily with other
955	modules and other event loops in the same program. Some of the modules	1136	AnyEvent modules and other event loops in the same program. Some of the
956	come with AnyEvent, most are available via CPAN.	1137	modules come as part of AnyEvent, the others are available via CPAN (see
		1138	L<http://search.cpan.org/search?m=module&q=anyevent%3A%3A*> for
		1139	a longer non-exhaustive list), and the list is heavily biased towards
		1140	modules of the AnyEvent author himself :)
957		1141
958	=over 4	1142	=over 4
959		1143
960	=item L<AnyEvent::Util>	1144	=item L<AnyEvent::Util>
961		1145
962	Contains various utility functions that replace often-used but blocking	1146	Contains various utility functions that replace often-used blocking
963	functions such as C<inet_aton> by event-/callback-based versions.	1147	functions such as C<inet_aton> with event/callback-based versions.
964		1148
965	=item L<AnyEvent::Socket>	1149	=item L<AnyEvent::Socket>
966		1150
967	Provides various utility functions for (internet protocol) sockets,	1151	Provides various utility functions for (internet protocol) sockets,
968	addresses and name resolution. Also functions to create non-blocking tcp	1152	addresses and name resolution. Also functions to create non-blocking tcp
…		…
970		1154
971	=item L<AnyEvent::Handle>	1155	=item L<AnyEvent::Handle>
972		1156
973	Provide read and write buffers, manages watchers for reads and writes,	1157	Provide read and write buffers, manages watchers for reads and writes,
974	supports raw and formatted I/O, I/O queued and fully transparent and	1158	supports raw and formatted I/O, I/O queued and fully transparent and
975	non-blocking SSL/TLS (via L<AnyEvent::TLS>.	1159	non-blocking SSL/TLS (via L<AnyEvent::TLS>).
976		1160
977	=item L<AnyEvent::DNS>	1161	=item L<AnyEvent::DNS>
978		1162
979	Provides rich asynchronous DNS resolver capabilities.	1163	Provides rich asynchronous DNS resolver capabilities.
980		1164
		1165	=item L<AnyEvent::HTTP>, L<AnyEvent::IRC>, L<AnyEvent::XMPP>, L<AnyEvent::GPSD>, L<AnyEvent::IGS>, L<AnyEvent::FCP>
		1166
		1167	Implement event-based interfaces to the protocols of the same name (for
		1168	the curious, IGS is the International Go Server and FCP is the Freenet
		1169	Client Protocol).
		1170
981	=item L<AnyEvent::HTTP>	1171	=item L<AnyEvent::AIO>
982		1172
983	A simple-to-use HTTP library that is capable of making a lot of concurrent	1173	Truly asynchronous (as opposed to non-blocking) I/O, should be in the
984	HTTP requests.	1174	toolbox of every event programmer. AnyEvent::AIO transparently fuses
		1175	L<IO::AIO> and AnyEvent together, giving AnyEvent access to event-based
		1176	file I/O, and much more.
		1177
		1178	=item L<AnyEvent::Filesys::Notify>
		1179
		1180	AnyEvent is good for non-blocking stuff, but it can't detect file or
		1181	path changes (e.g. "watch this directory for new files", "watch this
		1182	file for changes"). The L<AnyEvent::Filesys::Notify> module promises to
		1183	do just that in a portbale fashion, supporting inotify on GNU/Linux and
		1184	some weird, without doubt broken, stuff on OS X to monitor files. It can
		1185	fall back to blocking scans at regular intervals transparently on other
		1186	platforms, so it's about as portable as it gets.
		1187
		1188	(I haven't used it myself, but I haven't heard anybody complaining about
		1189	it yet).
		1190
		1191	=item L<AnyEvent::DBI>
		1192
		1193	Executes L<DBI> requests asynchronously in a proxy process for you,
		1194	notifying you in an event-based way when the operation is finished.
985		1195
986	=item L<AnyEvent::HTTPD>	1196	=item L<AnyEvent::HTTPD>
987		1197
988	Provides a simple web application server framework.	1198	A simple embedded webserver.
989		1199
990	=item L<AnyEvent::FastPing>	1200	=item L<AnyEvent::FastPing>
991		1201
992	The fastest ping in the west.	1202	The fastest ping in the west.
993		1203
994	=item L<AnyEvent::DBI>
995
996	Executes L<DBI> requests asynchronously in a proxy process.
997
998	=item L<AnyEvent::AIO>
999
1000	Truly asynchronous I/O, should be in the toolbox of every event
1001	programmer. AnyEvent::AIO transparently fuses L<IO::AIO> and AnyEvent
1002	together.
1003
1004	=item L<AnyEvent::BDB>
1005
1006	Truly asynchronous Berkeley DB access. AnyEvent::BDB transparently fuses
1007	L<BDB> and AnyEvent together.
1008
1009	=item L<AnyEvent::GPSD>
1010
1011	A non-blocking interface to gpsd, a daemon delivering GPS information.
1012
1013	=item L<AnyEvent::IRC>
1014
1015	AnyEvent based IRC client module family (replacing the older Net::IRC3).
1016
1017	=item L<AnyEvent::XMPP>
1018
1019	AnyEvent based XMPP (Jabber protocol) module family (replacing the older
1020	Net::XMPP2>.
1021
1022	=item L<AnyEvent::IGS>
1023
1024	A non-blocking interface to the Internet Go Server protocol (used by
1025	L<App::IGS>).
1026
1027	=item L<Net::FCP>
1028
1029	AnyEvent-based implementation of the Freenet Client Protocol, birthplace
1030	of AnyEvent.
1031
1032	=item L<Event::ExecFlow>
1033
1034	High level API for event-based execution flow control.
1035
1036	=item L<Coro>	1204	=item L<Coro>
1037		1205
1038	Has special support for AnyEvent via L<Coro::AnyEvent>.	1206	Has special support for AnyEvent via L<Coro::AnyEvent>, which allows you
		1207	to simply invert the flow control - don't call us, we will call you:
		1208
		1209	async {
		1210	Coro::AnyEvent::sleep 5; # creates a 5s timer and waits for it
		1211	print "5 seconds later!\n";
		1212
		1213	Coro::AnyEvent::readable *STDIN; # uses an I/O watcher
		1214	my $line = <STDIN>; # works for ttys
		1215
		1216	AnyEvent::HTTP::http_get "url", Coro::rouse_cb;
		1217	my ($body, $hdr) = Coro::rouse_wait;
		1218	};
1039		1219
1040	=back	1220	=back
1041		1221
1042	=cut	1222	=cut
1043		1223
1044	package AnyEvent;	1224	package AnyEvent;
1045		1225
1046	no warnings;	1226	# basically a tuned-down version of common::sense
1047	use strict qw(vars subs);	1227	sub common_sense {
		1228	# from common:.sense 3.5
		1229	local $^W;
		1230	${^WARNING_BITS} ^= ${^WARNING_BITS} ^ "\x3c\x3f\x33\x00\x0f\xf0\x0f\xc0\xf0\xfc\x33\x00";
		1231	# use strict vars subs - NO UTF-8, as Util.pm doesn't like this atm. (uts46data.pl)
		1232	$^H |= 0x00000600;
		1233	}
		1234
		1235	BEGIN { AnyEvent::common_sense }
1048		1236
1049	use Carp ();	1237	use Carp ();
1050		1238
1051	our $VERSION = 4.83;	1239	our $VERSION = '6.14';
1052	our $MODEL;	1240	our $MODEL;
1053
1054	our $AUTOLOAD;
1055	our @ISA;	1241	our @ISA;
1056
1057	our @REGISTRY;	1242	our @REGISTRY;
1058
1059	our $WIN32;
1060
1061	our $VERBOSE;	1243	our $VERBOSE;
		1244	our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred
		1245	our $MAX_SIGNAL_LATENCY = $ENV{PERL_ANYEVENT_MAX_SIGNAL_LATENCY} || 10; # executes after the BEGIN block below (tainting!)
1062		1246
1063	BEGIN {	1247	BEGIN {
1064	eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }";	1248	require "AnyEvent/constants.pl";
		1249
1065	eval "sub TAINT(){ " . (${^TAINT}*1) . " }";	1250	eval "sub TAINT (){" . (${^TAINT}*1) . "}";
1066		1251
1067	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}	1252	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}
1068	if ${^TAINT};	1253	if ${^TAINT};
1069		1254
1070	$VERBOSE = $ENV{PERL_ANYEVENT_VERBOSE}*1;	1255	$ENV{"PERL_ANYEVENT_$_"} = $ENV{"AE_$_"}
		1256	for grep s/^AE_// && !exists $ENV{"PERL_ANYEVENT_$_"}, keys %ENV;
1071		1257
1072	}	1258	@ENV{grep /^PERL_ANYEVENT_/, keys %ENV} = ()
		1259	if ${^TAINT};
1073		1260
1074	our $MAX_SIGNAL_LATENCY = 10;	1261	# $ENV{PERL_ANYEVENT_xxx} now valid
1075		1262
1076	our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred	1263	$VERBOSE = length $ENV{PERL_ANYEVENT_VERBOSE} ? $ENV{PERL_ANYEVENT_VERBOSE}*1 : 4;
1077		1264
1078	{
1079	my $idx;	1265	my $idx;
1080	$PROTOCOL{$_} = ++$idx	1266	$PROTOCOL{$_} = ++$idx
1081	for reverse split /\s*,\s*/,	1267	for reverse split /\s*,\s*/,
1082	$ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";	1268	$ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";
1083	}	1269	}
1084		1270
		1271	our @post_detect;
		1272
		1273	sub post_detect(&) {
		1274	my ($cb) = @_;
		1275
		1276	push @post_detect, $cb;
		1277
		1278	defined wantarray
		1279	? bless \$cb, "AnyEvent::Util::postdetect"
		1280	: ()
		1281	}
		1282
		1283	sub AnyEvent::Util::postdetect::DESTROY {
		1284	@post_detect = grep $_ != ${$_[0]}, @post_detect;
		1285	}
		1286
		1287	our $POSTPONE_W;
		1288	our @POSTPONE;
		1289
		1290	sub _postpone_exec {
		1291	undef $POSTPONE_W;
		1292
		1293	&{ shift @POSTPONE }
		1294	while @POSTPONE;
		1295	}
		1296
		1297	sub postpone(&) {
		1298	push @POSTPONE, shift;
		1299
		1300	$POSTPONE_W ||= AE::timer (0, 0, \&_postpone_exec);
		1301
		1302	()
		1303	}
		1304
		1305	sub log($$;@) {
		1306	# only load the big bloated module when we actually are about to log something
		1307	if ($_[0] <= ($VERBOSE || 1)) { # also catches non-numeric levels(!) and fatal
		1308	local ($!, $@);
		1309	require AnyEvent::Log; # among other things, sets $VERBOSE to 9
		1310	# AnyEvent::Log overwrites this function
		1311	goto &log;
		1312	}
		1313
		1314	0 # not logged
		1315	}
		1316
		1317	sub _logger($;$) {
		1318	my ($level, $renabled) = @_;
		1319
		1320	$$renabled = $level <= $VERBOSE;
		1321
		1322	my $logger = [(caller)[0], $level, $renabled];
		1323
		1324	$AnyEvent::Log::LOGGER{$logger+0} = $logger;
		1325
		1326	# return unless defined wantarray;
		1327	#
		1328	# require AnyEvent::Util;
		1329	# my $guard = AnyEvent::Util::guard (sub {
		1330	# # "clean up"
		1331	# delete $LOGGER{$logger+0};
		1332	# });
		1333	#
		1334	# sub {
		1335	# return 0 unless $$renabled;
		1336	#
		1337	# $guard if 0; # keep guard alive, but don't cause runtime overhead
		1338	# require AnyEvent::Log unless $AnyEvent::Log::VERSION;
		1339	# package AnyEvent::Log;
		1340	# _log ($logger->[0], $level, @_) # logger->[0] has been converted at load time
		1341	# }
		1342	}
		1343
		1344	if (length $ENV{PERL_ANYEVENT_LOG}) {
		1345	require AnyEvent::Log; # AnyEvent::Log does the thing for us
		1346	}
		1347
1085	my @models = (	1348	our @models = (
1086	[EV:: => AnyEvent::Impl::EV::],	1349	[EV:: => AnyEvent::Impl::EV::],
1087	[Event:: => AnyEvent::Impl::Event::],
1088	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::],	1350	[AnyEvent::Loop:: => AnyEvent::Impl::Perl::],
1089	# everything below here will not be autoprobed	1351	# everything below here will not (normally) be autoprobed
1090	# as the pureperl backend should work everywhere	1352	# as the pure perl backend should work everywhere
1091	# and is usually faster	1353	# and is usually faster
		1354	[Irssi:: => AnyEvent::Impl::Irssi::], # Irssi has a bogus "Event" package, so msut be near the top
		1355	[Event:: => AnyEvent::Impl::Event::], # slow, stable
1092	[Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers	1356	[Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers
		1357	# everything below here should not be autoloaded
1093	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy	1358	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
1094	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles	1359	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
1095	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program	1360	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program
1096	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza	1361	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
1097	[Wx:: => AnyEvent::Impl::POE::],	1362	[Wx:: => AnyEvent::Impl::POE::],
1098	[Prima:: => AnyEvent::Impl::POE::],	1363	[Prima:: => AnyEvent::Impl::POE::],
1099	# IO::Async is just too broken - we would need workarounds for its	1364	[IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # a bitch to autodetect
1100	# byzantine signal and broken child handling, among others.	1365	[Cocoa::EventLoop:: => AnyEvent::Impl::Cocoa::],
1101	# IO::Async is rather hard to detect, as it doesn't have any	1366	[FLTK:: => AnyEvent::Impl::FLTK::],
1102	# obvious default class.
1103	# [IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program
1104	# [IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program
1105	# [IO::Async::Notifier:: => AnyEvent::Impl::IOAsync::], # requires special main program
1106	);	1367	);
1107		1368
1108	our %method = map +($_ => 1),	1369	our @isa_hook;
		1370
		1371	sub _isa_set {
		1372	my @pkg = ("AnyEvent", (map $_->[0], grep defined, @isa_hook), $MODEL);
		1373
		1374	@{"$pkg[$_-1]::ISA"} = $pkg[$_]
		1375	for 1 .. $#pkg;
		1376
		1377	grep $_ && $_->[1], @isa_hook
		1378	and AE::_reset ();
		1379	}
		1380
		1381	# used for hooking AnyEvent::Strict and AnyEvent::Debug::Wrap into the class hierarchy
		1382	sub _isa_hook($$;$) {
		1383	my ($i, $pkg, $reset_ae) = @_;
		1384
		1385	$isa_hook[$i] = $pkg ? [$pkg, $reset_ae] : undef;
		1386
		1387	_isa_set;
		1388	}
		1389
		1390	# all autoloaded methods reserve the complete glob, not just the method slot.
		1391	# due to bugs in perls method cache implementation.
1109	qw(io timer time now now_update signal child idle condvar one_event DESTROY);	1392	our @methods = qw(io timer time now now_update signal child idle condvar);
1110		1393
1111	our @post_detect;
1112
1113	sub post_detect(&) {	1394	sub detect() {
1114	my ($cb) = @_;	1395	return $MODEL if $MODEL; # some programs keep references to detect
1115		1396
1116	if ($MODEL) {	1397	# IO::Async::Loop::AnyEvent is extremely evil, refuse to work with it
1117	$cb->();	1398	# the author knows about the problems and what it does to AnyEvent as a whole
		1399	# (and the ability of others to use AnyEvent), but simply wants to abuse AnyEvent
		1400	# anyway.
		1401	AnyEvent::log fatal => "AnyEvent: IO::Async::Loop::AnyEvent detected - that module is broken by\n"
		1402	. "design, abuses internals and breaks AnyEvent - will not continue."
		1403	if exists $INC{"IO/Async/Loop/AnyEvent.pm"};
1118		1404
1119	1	1405	local $!; # for good measure
		1406	local $SIG{__DIE__}; # we use eval
		1407
		1408	# free some memory
		1409	*detect = sub () { $MODEL };
		1410	# undef &func doesn't correctly update the method cache. grmbl.
		1411	# so we delete the whole glob. grmbl.
		1412	# otoh, perl doesn't let me undef an active usb, but it lets me free
		1413	# a glob with an active sub. hrm. i hope it works, but perl is
		1414	# usually buggy in this department. sigh.
		1415	delete @{"AnyEvent::"}{@methods};
		1416	undef @methods;
		1417
		1418	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z0-9:]+)$/) {
		1419	my $model = $1;
		1420	$model = "AnyEvent::Impl::$model" unless $model =~ s/::$//;
		1421	if (eval "require $model") {
		1422	AnyEvent::log 7 => "loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.";
		1423	$MODEL = $model;
1120	} else {	1424	} else {
1121	push @post_detect, $cb;	1425	AnyEvent::log 4 => "unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@";
1122		1426	}
1123	defined wantarray
1124	? bless \$cb, "AnyEvent::Util::postdetect"
1125	: ()
1126	}	1427	}
1127	}
1128		1428
1129	sub AnyEvent::Util::postdetect::DESTROY {	1429	# check for already loaded models
1130	@post_detect = grep $_ != ${$_[0]}, @post_detect;
1131	}
1132
1133	sub detect() {
1134	unless ($MODEL) {	1430	unless ($MODEL) {
1135	no strict 'refs';	1431	for (@REGISTRY, @models) {
1136	local $SIG{__DIE__};	1432	my ($package, $model) = @$_;
1137		1433	if (${"$package\::VERSION"} > 0) {
1138	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {
1139	my $model = "AnyEvent::Impl::$1";
1140	if (eval "require $model") {	1434	if (eval "require $model") {
		1435	AnyEvent::log 7 => "autodetected model '$model', using it.";
1141	$MODEL = $model;	1436	$MODEL = $model;
1142	warn "AnyEvent: loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.\n" if $VERBOSE >= 2;	1437	last;
1143	} else {	1438	} else {
1144	warn "AnyEvent: unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@" if $VERBOSE;	1439	AnyEvent::log 8 => "detected event loop $package, but cannot load '$model', skipping: $@";
		1440	}
1145	}	1441	}
1146	}	1442	}
1147		1443
1148	# check for already loaded models
1149	unless ($MODEL) {	1444	unless ($MODEL) {
		1445	# try to autoload a model
1150	for (@REGISTRY, @models) {	1446	for (@REGISTRY, @models) {
1151	my ($package, $model) = @$_;	1447	my ($package, $model) = @$_;
		1448	if (
		1449	eval "require $package"
1152	if (${"$package\::VERSION"} > 0) {	1450	and ${"$package\::VERSION"} > 0
1153	if (eval "require $model") {	1451	and eval "require $model"
		1452	) {
		1453	AnyEvent::log 7 => "autoloaded model '$model', using it.";
1154	$MODEL = $model;	1454	$MODEL = $model;
1155	warn "AnyEvent: autodetected model '$model', using it.\n" if $VERBOSE >= 2;
1156	last;	1455	last;
1157	}
1158	}	1456	}
1159	}	1457	}
1160		1458
1161	unless ($MODEL) {
1162	# try to load a model
1163
1164	for (@REGISTRY, @models) {
1165	my ($package, $model) = @$_;
1166	if (eval "require $package"
1167	and ${"$package\::VERSION"} > 0
1168	and eval "require $model") {
1169	$MODEL = $model;
1170	warn "AnyEvent: autoprobed model '$model', using it.\n" if $VERBOSE >= 2;
1171	last;
1172	}
1173	}
1174
1175	$MODEL	1459	$MODEL
1176	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.\n";	1460	or AnyEvent::log fatal => "AnyEvent: backend autodetection failed - did you properly install AnyEvent?";
1177	}
1178	}	1461	}
1179
1180	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
1181
1182	unshift @ISA, $MODEL;
1183
1184	require AnyEvent::Strict if $ENV{PERL_ANYEVENT_STRICT};
1185
1186	(shift @post_detect)->() while @post_detect;
1187	}	1462	}
1188		1463
		1464	# free memory only needed for probing
		1465	undef @models;
		1466	undef @REGISTRY;
		1467
		1468	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
		1469
		1470	# now nuke some methods that are overridden by the backend.
		1471	# SUPER usage is not allowed in these.
		1472	for (qw(time signal child idle)) {
		1473	undef &{"AnyEvent::Base::$_"}
		1474	if defined &{"$MODEL\::$_"};
		1475	}
		1476
		1477	_isa_set;
		1478
		1479	# we're officially open!
		1480
		1481	if ($ENV{PERL_ANYEVENT_STRICT}) {
		1482	require AnyEvent::Strict;
		1483	}
		1484
		1485	if ($ENV{PERL_ANYEVENT_DEBUG_WRAP}) {
		1486	require AnyEvent::Debug;
		1487	AnyEvent::Debug::wrap ($ENV{PERL_ANYEVENT_DEBUG_WRAP});
		1488	}
		1489
		1490	if (length $ENV{PERL_ANYEVENT_DEBUG_SHELL}) {
		1491	require AnyEvent::Socket;
		1492	require AnyEvent::Debug;
		1493
		1494	my $shell = $ENV{PERL_ANYEVENT_DEBUG_SHELL};
		1495	$shell =~ s/\$\$/$$/g;
		1496
		1497	my ($host, $service) = AnyEvent::Socket::parse_hostport ($shell);
		1498	$AnyEvent::Debug::SHELL = AnyEvent::Debug::shell ($host, $service);
		1499	}
		1500
		1501	# now the anyevent environment is set up as the user told us to, so
		1502	# call the actual user code - post detects
		1503
		1504	(shift @post_detect)->() while @post_detect;
		1505	undef @post_detect;
		1506
		1507	*post_detect = sub(&) {
		1508	shift->();
		1509
		1510	undef
		1511	};
		1512
1189	$MODEL	1513	$MODEL
1190	}	1514	}
1191		1515
1192	sub AUTOLOAD {	1516	for my $name (@methods) {
1193	(my $func = $AUTOLOAD) =~ s/.*://;	1517	*$name = sub {
1194		1518	detect;
1195	$method{$func}	1519	# we use goto because
1196	or Carp::croak "$func: not a valid method for AnyEvent objects";	1520	# a) it makes the thunk more transparent
1197		1521	# b) it allows us to delete the thunk later
1198	detect unless $MODEL;	1522	goto &{ UNIVERSAL::can AnyEvent => "SUPER::$name" }
1199		1523	};
1200	my $class = shift;
1201	$class->$func (@_);
1202	}	1524	}
1203		1525
1204	# utility function to dup a filehandle. this is used by many backends	1526	# utility function to dup a filehandle. this is used by many backends
1205	# to support binding more than one watcher per filehandle (they usually	1527	# to support binding more than one watcher per filehandle (they usually
1206	# allow only one watcher per fd, so we dup it to get a different one).	1528	# allow only one watcher per fd, so we dup it to get a different one).
…		…
1216	# we assume CLOEXEC is already set by perl in all important cases	1538	# we assume CLOEXEC is already set by perl in all important cases
1217		1539
1218	($fh2, $rw)	1540	($fh2, $rw)
1219	}	1541	}
1220		1542
		1543	=head1 SIMPLIFIED AE API
		1544
		1545	Starting with version 5.0, AnyEvent officially supports a second, much
		1546	simpler, API that is designed to reduce the calling, typing and memory
		1547	overhead by using function call syntax and a fixed number of parameters.
		1548
		1549	See the L<AE> manpage for details.
		1550
		1551	=cut
		1552
		1553	package AE;
		1554
		1555	our $VERSION = $AnyEvent::VERSION;
		1556
		1557	sub _reset() {
		1558	eval q{
		1559	# fall back to the main API by default - backends and AnyEvent::Base
		1560	# implementations can overwrite these.
		1561
		1562	sub io($$$) {
		1563	AnyEvent->io (fh => $_[0], poll => $_[1] ? "w" : "r", cb => $_[2])
		1564	}
		1565
		1566	sub timer($$$) {
		1567	AnyEvent->timer (after => $_[0], interval => $_[1], cb => $_[2])
		1568	}
		1569
		1570	sub signal($$) {
		1571	AnyEvent->signal (signal => $_[0], cb => $_[1])
		1572	}
		1573
		1574	sub child($$) {
		1575	AnyEvent->child (pid => $_[0], cb => $_[1])
		1576	}
		1577
		1578	sub idle($) {
		1579	AnyEvent->idle (cb => $_[0]);
		1580	}
		1581
		1582	sub cv(;&) {
		1583	AnyEvent->condvar (@_ ? (cb => $_[0]) : ())
		1584	}
		1585
		1586	sub now() {
		1587	AnyEvent->now
		1588	}
		1589
		1590	sub now_update() {
		1591	AnyEvent->now_update
		1592	}
		1593
		1594	sub time() {
		1595	AnyEvent->time
		1596	}
		1597
		1598	*postpone = \&AnyEvent::postpone;
		1599	*log = \&AnyEvent::log;
		1600	};
		1601	die if $@;
		1602	}
		1603
		1604	BEGIN { _reset }
		1605
1221	package AnyEvent::Base;	1606	package AnyEvent::Base;
1222		1607
1223	# default implementations for many methods	1608	# default implementations for many methods
1224		1609
1225	sub _time {	1610	sub time {
		1611	eval q{ # poor man's autoloading {}
1226	# probe for availability of Time::HiRes	1612	# probe for availability of Time::HiRes
1227	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {	1613	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {
1228	warn "AnyEvent: using Time::HiRes for sub-second timing accuracy.\n" if $VERBOSE >= 8;	1614	*time = sub { Time::HiRes::time () };
1229	*_time = \&Time::HiRes::time;	1615	*AE::time = \& Time::HiRes::time ;
		1616	*now = \&time;
		1617	AnyEvent::log 8 => "AnyEvent: using Time::HiRes for sub-second timing accuracy.";
1230	# if (eval "use POSIX (); (POSIX::times())...	1618	# if (eval "use POSIX (); (POSIX::times())...
1231	} else {	1619	} else {
		1620	*time = sub { CORE::time };
		1621	*AE::time = sub (){ CORE::time };
		1622	*now = \&time;
1232	warn "AnyEvent: using built-in time(), WARNING, no sub-second resolution!\n" if $VERBOSE;	1623	AnyEvent::log 3 => "using built-in time(), WARNING, no sub-second resolution!";
1233	*_time = sub { time }; # epic fail	1624	}
1234	}	1625	};
		1626	die if $@;
1235		1627
1236	&_time	1628	&time
1237	}	1629	}
1238		1630
1239	sub time { _time }	1631	*now = \&time;
1240	sub now { _time }
1241	sub now_update { }	1632	sub now_update { }
1242		1633
		1634	sub _poll {
		1635	Carp::croak "$AnyEvent::MODEL does not support blocking waits. Caught";
		1636	}
		1637
1243	# default implementation for ->condvar	1638	# default implementation for ->condvar
		1639	# in fact, the default should not be overwritten
1244		1640
1245	sub condvar {	1641	sub condvar {
		1642	eval q{ # poor man's autoloading {}
		1643	*condvar = sub {
1246	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"	1644	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"
		1645	};
		1646
		1647	*AE::cv = sub (;&) {
		1648	bless { @_ ? (_ae_cb => shift) : () }, "AnyEvent::CondVar"
		1649	};
		1650	};
		1651	die if $@;
		1652
		1653	&condvar
1247	}	1654	}
1248		1655
1249	# default implementation for ->signal	1656	# default implementation for ->signal
1250		1657
1251	our $HAVE_ASYNC_INTERRUPT;	1658	our $HAVE_ASYNC_INTERRUPT;
		1659
		1660	sub _have_async_interrupt() {
		1661	$HAVE_ASYNC_INTERRUPT = 1*(!$ENV{PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT}
		1662	&& eval "use Async::Interrupt 1.02 (); 1")
		1663	unless defined $HAVE_ASYNC_INTERRUPT;
		1664
		1665	$HAVE_ASYNC_INTERRUPT
		1666	}
		1667
1252	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);	1668	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);
1253	our (%SIG_ASY, %SIG_ASY_W);	1669	our (%SIG_ASY, %SIG_ASY_W);
1254	our ($SIG_COUNT, $SIG_TW);	1670	our ($SIG_COUNT, $SIG_TW);
1255		1671
1256	sub _signal_exec {	1672	# install a dummy wakeup watcher to reduce signal catching latency
1257	$HAVE_ASYNC_INTERRUPT	1673	# used by Impls
1258	? $SIGPIPE_R->drain	1674	sub _sig_add() {
1259	: sysread $SIGPIPE_R, my $dummy, 9;	1675	unless ($SIG_COUNT++) {
		1676	# try to align timer on a full-second boundary, if possible
		1677	my $NOW = AE::now;
1260		1678
1261	while (%SIG_EV) {	1679	$SIG_TW = AE::timer
1262	for (keys %SIG_EV) {	1680	$MAX_SIGNAL_LATENCY - ($NOW - int $NOW),
1263	delete $SIG_EV{$_};	1681	$MAX_SIGNAL_LATENCY,
1264	$_->() for values %{ $SIG_CB{$_} || {} };	1682	sub { } # just for the PERL_ASYNC_CHECK
1265	}	1683	;
1266	}	1684	}
1267	}	1685	}
1268		1686
1269	sub _signal {	1687	sub _sig_del {
1270	my (undef, %arg) = @_;
1271
1272	my $signal = uc $arg{signal}
1273	or Carp::croak "required option 'signal' is missing";
1274
1275	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
1276
1277	if ($HAVE_ASYNC_INTERRUPT) {
1278	# async::interrupt
1279
1280	$SIG_ASY{$signal} ||= do {
1281	my $asy = new Async::Interrupt
1282	cb => sub { undef $SIG_EV{$signal} },
1283	signal => $signal,
1284	pipe => [$SIGPIPE_R->filenos],
1285	;
1286	$asy->pipe_autodrain (0);
1287
1288	$asy
1289	};
1290
1291	} else {
1292	# pure perl
1293
1294	$SIG{$signal} ||= sub {
1295	local $!;
1296	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;
1297	undef $SIG_EV{$signal};
1298	};
1299
1300	# can't do signal processing without introducing races in pure perl,
1301	# so limit the signal latency.
1302	++$SIG_COUNT;
1303	$SIG_TW ||= AnyEvent->timer (
1304	after => $MAX_SIGNAL_LATENCY,
1305	interval => $MAX_SIGNAL_LATENCY,
1306	cb => sub { }, # just for the PERL_ASYNC_CHECK
1307	);
1308	}
1309
1310	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
1311	}
1312
1313	sub signal {
1314	# probe for availability of Async::Interrupt
1315	if (!$ENV{PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT} && eval "use Async::Interrupt 0.6 (); 1") {
1316	warn "AnyEvent: using Async::Interrupt for race-free signal handling.\n" if $VERBOSE >= 8;
1317
1318	$HAVE_ASYNC_INTERRUPT = 1;
1319	$SIGPIPE_R = new Async::Interrupt::EventPipe;
1320	$SIG_IO = AnyEvent->io (fh => $SIGPIPE_R->fileno, poll => "r", cb => \&_signal_exec);
1321
1322	} else {
1323	warn "AnyEvent: using emulated perl signal handling with latency timer.\n" if $VERBOSE >= 8;
1324
1325	require Fcntl;
1326
1327	if (AnyEvent::WIN32) {
1328	require AnyEvent::Util;
1329
1330	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
1331	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R) if $SIGPIPE_R;
1332	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W) if $SIGPIPE_W; # just in case
1333	} else {
1334	pipe $SIGPIPE_R, $SIGPIPE_W;
1335	fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R;
1336	fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case
1337
1338	# not strictly required, as $^F is normally 2, but let's make sure...
1339	fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
1340	fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
1341	}
1342
1343	$SIGPIPE_R
1344	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";
1345
1346	$SIG_IO = AnyEvent->io (fh => $SIGPIPE_R, poll => "r", cb => \&_signal_exec);
1347	}
1348
1349	*signal = \&_signal;
1350	&signal
1351	}
1352
1353	sub AnyEvent::Base::signal::DESTROY {
1354	my ($signal, $cb) = @{$_[0]};
1355
1356	undef $SIG_TW	1688	undef $SIG_TW
1357	unless --$SIG_COUNT;	1689	unless --$SIG_COUNT;
		1690	}
1358		1691
		1692	our $_sig_name_init; $_sig_name_init = sub {
		1693	eval q{ # poor man's autoloading {}
		1694	undef $_sig_name_init;
		1695
		1696	if (_have_async_interrupt) {
		1697	*sig2num = \&Async::Interrupt::sig2num;
		1698	*sig2name = \&Async::Interrupt::sig2name;
		1699	} else {
		1700	require Config;
		1701
		1702	my %signame2num;
		1703	@signame2num{ split ' ', $Config::Config{sig_name} }
		1704	= split ' ', $Config::Config{sig_num};
		1705
		1706	my @signum2name;
		1707	@signum2name[values %signame2num] = keys %signame2num;
		1708
		1709	*sig2num = sub($) {
		1710	$_[0] > 0 ? shift : $signame2num{+shift}
		1711	};
		1712	*sig2name = sub ($) {
		1713	$_[0] > 0 ? $signum2name[+shift] : shift
		1714	};
		1715	}
		1716	};
		1717	die if $@;
		1718	};
		1719
		1720	sub sig2num ($) { &$_sig_name_init; &sig2num }
		1721	sub sig2name($) { &$_sig_name_init; &sig2name }
		1722
		1723	sub signal {
		1724	eval q{ # poor man's autoloading {}
		1725	# probe for availability of Async::Interrupt
		1726	if (_have_async_interrupt) {
		1727	AnyEvent::log 8 => "using Async::Interrupt for race-free signal handling.";
		1728
		1729	$SIGPIPE_R = new Async::Interrupt::EventPipe;
		1730	$SIG_IO = AE::io $SIGPIPE_R->fileno, 0, \&_signal_exec;
		1731
		1732	} else {
		1733	AnyEvent::log 8 => "using emulated perl signal handling with latency timer.";
		1734
		1735	if (AnyEvent::WIN32) {
		1736	require AnyEvent::Util;
		1737
		1738	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
		1739	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R, 1) if $SIGPIPE_R;
		1740	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W, 1) if $SIGPIPE_W; # just in case
		1741	} else {
		1742	pipe $SIGPIPE_R, $SIGPIPE_W;
		1743	fcntl $SIGPIPE_R, AnyEvent::F_SETFL, AnyEvent::O_NONBLOCK if $SIGPIPE_R;
		1744	fcntl $SIGPIPE_W, AnyEvent::F_SETFL, AnyEvent::O_NONBLOCK if $SIGPIPE_W; # just in case
		1745
		1746	# not strictly required, as $^F is normally 2, but let's make sure...
		1747	fcntl $SIGPIPE_R, AnyEvent::F_SETFD, AnyEvent::FD_CLOEXEC;
		1748	fcntl $SIGPIPE_W, AnyEvent::F_SETFD, AnyEvent::FD_CLOEXEC;
		1749	}
		1750
		1751	$SIGPIPE_R
		1752	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";
		1753
		1754	$SIG_IO = AE::io $SIGPIPE_R, 0, \&_signal_exec;
		1755	}
		1756
		1757	*signal = $HAVE_ASYNC_INTERRUPT
		1758	? sub {
		1759	my (undef, %arg) = @_;
		1760
		1761	# async::interrupt
		1762	my $signal = sig2num $arg{signal};
		1763	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
		1764
		1765	$SIG_ASY{$signal} ||= new Async::Interrupt
		1766	cb => sub { undef $SIG_EV{$signal} },
		1767	signal => $signal,
		1768	pipe => [$SIGPIPE_R->filenos],
		1769	pipe_autodrain => 0,
		1770	;
		1771
		1772	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
		1773	}
		1774	: sub {
		1775	my (undef, %arg) = @_;
		1776
		1777	# pure perl
		1778	my $signal = sig2name $arg{signal};
		1779	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
		1780
		1781	$SIG{$signal} ||= sub {
		1782	local $!;
		1783	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;
		1784	undef $SIG_EV{$signal};
		1785	};
		1786
		1787	# can't do signal processing without introducing races in pure perl,
		1788	# so limit the signal latency.
		1789	_sig_add;
		1790
		1791	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
		1792	}
		1793	;
		1794
		1795	*AnyEvent::Base::signal::DESTROY = sub {
		1796	my ($signal, $cb) = @{$_[0]};
		1797
		1798	_sig_del;
		1799
1359	delete $SIG_CB{$signal}{$cb};	1800	delete $SIG_CB{$signal}{$cb};
1360		1801
		1802	$HAVE_ASYNC_INTERRUPT
		1803	? delete $SIG_ASY{$signal}
1361	# delete doesn't work with older perls - they then	1804	: # delete doesn't work with older perls - they then
1362	# print weird messages, or just unconditionally exit	1805	# print weird messages, or just unconditionally exit
1363	# instead of getting the default action.	1806	# instead of getting the default action.
1364	undef $SIG{$signal}	1807	undef $SIG{$signal}
1365	unless keys %{ $SIG_CB{$signal} };	1808	unless keys %{ $SIG_CB{$signal} };
		1809	};
		1810
		1811	*_signal_exec = sub {
		1812	$HAVE_ASYNC_INTERRUPT
		1813	? $SIGPIPE_R->drain
		1814	: sysread $SIGPIPE_R, (my $dummy), 9;
		1815
		1816	while (%SIG_EV) {
		1817	for (keys %SIG_EV) {
		1818	delete $SIG_EV{$_};
		1819	&$_ for values %{ $SIG_CB{$_} || {} };
		1820	}
		1821	}
		1822	};
		1823	};
		1824	die if $@;
		1825
		1826	&signal
1366	}	1827	}
1367		1828
1368	# default implementation for ->child	1829	# default implementation for ->child
1369		1830
1370	our %PID_CB;	1831	our %PID_CB;
1371	our $CHLD_W;	1832	our $CHLD_W;
1372	our $CHLD_DELAY_W;	1833	our $CHLD_DELAY_W;
1373	our $WNOHANG;
1374		1834
1375	sub _sigchld {	1835	# used by many Impl's
1376	while (0 < (my $pid = waitpid -1, $WNOHANG)) {	1836	sub _emit_childstatus($$) {
1377	$_->($pid, $?)	1837	my (undef, $rpid, $rstatus) = @_;
		1838
		1839	$_->($rpid, $rstatus)
1378	for values %{ $PID_CB{$pid} || {} },	1840	for values %{ $PID_CB{$rpid} || {} },
1379	values %{ $PID_CB{0} || {} };	1841	values %{ $PID_CB{0} || {} };
1380	}
1381	}	1842	}
1382		1843
1383	sub child {	1844	sub child {
		1845	eval q{ # poor man's autoloading {}
		1846	*_sigchld = sub {
		1847	my $pid;
		1848
		1849	AnyEvent->_emit_childstatus ($pid, $?)
		1850	while ($pid = waitpid -1, WNOHANG) > 0;
		1851	};
		1852
		1853	*child = sub {
1384	my (undef, %arg) = @_;	1854	my (undef, %arg) = @_;
1385		1855
1386	defined (my $pid = $arg{pid} + 0)	1856	my $pid = $arg{pid};
1387	or Carp::croak "required option 'pid' is missing";	1857	my $cb = $arg{cb};
1388		1858
1389	$PID_CB{$pid}{$arg{cb}} = $arg{cb};	1859	$PID_CB{$pid}{$cb+0} = $cb;
1390		1860
1391	$WNOHANG ||= eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1;
1392
1393	unless ($CHLD_W) {	1861	unless ($CHLD_W) {
1394	$CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld);	1862	$CHLD_W = AE::signal CHLD => \&_sigchld;
1395	# child could be a zombie already, so make at least one round	1863	# child could be a zombie already, so make at least one round
1396	&_sigchld;	1864	&_sigchld;
1397	}	1865	}
1398		1866
1399	bless [$pid, $arg{cb}], "AnyEvent::Base::child"	1867	bless [$pid, $cb+0], "AnyEvent::Base::child"
1400	}	1868	};
1401		1869
1402	sub AnyEvent::Base::child::DESTROY {	1870	*AnyEvent::Base::child::DESTROY = sub {
1403	my ($pid, $cb) = @{$_[0]};	1871	my ($pid, $icb) = @{$_[0]};
1404		1872
1405	delete $PID_CB{$pid}{$cb};	1873	delete $PID_CB{$pid}{$icb};
1406	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };	1874	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };
1407		1875
1408	undef $CHLD_W unless keys %PID_CB;	1876	undef $CHLD_W unless keys %PID_CB;
		1877	};
		1878	};
		1879	die if $@;
		1880
		1881	&child
1409	}	1882	}
1410		1883
1411	# idle emulation is done by simply using a timer, regardless	1884	# idle emulation is done by simply using a timer, regardless
1412	# of whether the process is idle or not, and not letting	1885	# of whether the process is idle or not, and not letting
1413	# the callback use more than 50% of the time.	1886	# the callback use more than 50% of the time.
1414	sub idle {	1887	sub idle {
		1888	eval q{ # poor man's autoloading {}
		1889	*idle = sub {
1415	my (undef, %arg) = @_;	1890	my (undef, %arg) = @_;
1416		1891
1417	my ($cb, $w, $rcb) = $arg{cb};	1892	my ($cb, $w, $rcb) = $arg{cb};
1418		1893
1419	$rcb = sub {	1894	$rcb = sub {
1420	if ($cb) {	1895	if ($cb) {
1421	$w = _time;	1896	$w = AE::time;
1422	&$cb;	1897	&$cb;
1423	$w = _time - $w;	1898	$w = AE::time - $w;
1424		1899
1425	# never use more then 50% of the time for the idle watcher,	1900	# never use more then 50% of the time for the idle watcher,
1426	# within some limits	1901	# within some limits
1427	$w = 0.0001 if $w < 0.0001;	1902	$w = 0.0001 if $w < 0.0001;
1428	$w = 5 if $w > 5;	1903	$w = 5 if $w > 5;
1429		1904
1430	$w = AnyEvent->timer (after => $w, cb => $rcb);	1905	$w = AE::timer $w, 0, $rcb;
1431	} else {	1906	} else {
1432	# clean up...	1907	# clean up...
1433	undef $w;	1908	undef $w;
1434	undef $rcb;	1909	undef $rcb;
		1910	}
		1911	};
		1912
		1913	$w = AE::timer 0.05, 0, $rcb;
		1914
		1915	bless \\$cb, "AnyEvent::Base::idle"
1435	}	1916	};
		1917
		1918	*AnyEvent::Base::idle::DESTROY = sub {
		1919	undef $${$_[0]};
		1920	};
1436	};	1921	};
		1922	die if $@;
1437		1923
1438	$w = AnyEvent->timer (after => 0.05, cb => $rcb);	1924	&idle
1439
1440	bless \\$cb, "AnyEvent::Base::idle"
1441	}
1442
1443	sub AnyEvent::Base::idle::DESTROY {
1444	undef $${$_[0]};
1445	}	1925	}
1446		1926
1447	package AnyEvent::CondVar;	1927	package AnyEvent::CondVar;
1448		1928
1449	our @ISA = AnyEvent::CondVar::Base::;	1929	our @ISA = AnyEvent::CondVar::Base::;
1450		1930
		1931	# only to be used for subclassing
		1932	sub new {
		1933	my $class = shift;
		1934	bless AnyEvent->condvar (@_), $class
		1935	}
		1936
1451	package AnyEvent::CondVar::Base;	1937	package AnyEvent::CondVar::Base;
1452		1938
1453	use overload	1939	#use overload
1454	'&{}' => sub { my $self = shift; sub { $self->send (@_) } },	1940	# '&{}' => sub { my $self = shift; sub { $self->send (@_) } },
1455	fallback => 1;	1941	# fallback => 1;
		1942
		1943	# save 300+ kilobytes by dirtily hardcoding overloading
		1944	${"AnyEvent::CondVar::Base::OVERLOAD"}{dummy}++; # Register with magic by touching.
		1945	*{'AnyEvent::CondVar::Base::()'} = sub { }; # "Make it findable via fetchmethod."
		1946	*{'AnyEvent::CondVar::Base::(&{}'} = sub { my $self = shift; sub { $self->send (@_) } }; # &{}
		1947	${'AnyEvent::CondVar::Base::()'} = 1; # fallback
1456		1948
1457	our $WAITING;	1949	our $WAITING;
1458		1950
1459	sub _send {	1951	sub _send {
1460	# nop	1952	# nop
		1953	}
		1954
		1955	sub _wait {
		1956	AnyEvent->_poll until $_[0]{_ae_sent};
1461	}	1957	}
1462		1958
1463	sub send {	1959	sub send {
1464	my $cv = shift;	1960	my $cv = shift;
1465	$cv->{_ae_sent} = [@_];	1961	$cv->{_ae_sent} = [@_];
…		…
1474		1970
1475	sub ready {	1971	sub ready {
1476	$_[0]{_ae_sent}	1972	$_[0]{_ae_sent}
1477	}	1973	}
1478		1974
1479	sub _wait {
1480	$WAITING
1481	and !$_[0]{_ae_sent}
1482	and Carp::croak "AnyEvent::CondVar: recursive blocking wait detected";
1483
1484	local $WAITING = 1;
1485	AnyEvent->one_event while !$_[0]{_ae_sent};
1486	}
1487
1488	sub recv {	1975	sub recv {
		1976	unless ($_[0]{_ae_sent}) {
		1977	$WAITING
		1978	and Carp::croak "AnyEvent::CondVar: recursive blocking wait attempted";
		1979
		1980	local $WAITING = 1;
1489	$_[0]->_wait;	1981	$_[0]->_wait;
		1982	}
1490		1983
1491	Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak};	1984	$_[0]{_ae_croak}
1492	wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0]	1985	and Carp::croak $_[0]{_ae_croak};
		1986
		1987	wantarray
		1988	? @{ $_[0]{_ae_sent} }
		1989	: $_[0]{_ae_sent}[0]
1493	}	1990	}
1494		1991
1495	sub cb {	1992	sub cb {
1496	$_[0]{_ae_cb} = $_[1] if @_ > 1;	1993	my $cv = shift;
		1994
		1995	@_
		1996	and $cv->{_ae_cb} = shift
		1997	and $cv->{_ae_sent}
		1998	and (delete $cv->{_ae_cb})->($cv);
		1999
1497	$_[0]{_ae_cb}	2000	$cv->{_ae_cb}
1498	}	2001	}
1499		2002
1500	sub begin {	2003	sub begin {
1501	++$_[0]{_ae_counter};	2004	++$_[0]{_ae_counter};
1502	$_[0]{_ae_end_cb} = $_[1] if @_ > 1;	2005	$_[0]{_ae_end_cb} = $_[1] if @_ > 1;
…		…
1507	&{ $_[0]{_ae_end_cb} || sub { $_[0]->send } };	2010	&{ $_[0]{_ae_end_cb} || sub { $_[0]->send } };
1508	}	2011	}
1509		2012
1510	# undocumented/compatibility with pre-3.4	2013	# undocumented/compatibility with pre-3.4
1511	*broadcast = \&send;	2014	*broadcast = \&send;
1512	*wait = \&_wait;	2015	*wait = \&recv;
1513		2016
1514	=head1 ERROR AND EXCEPTION HANDLING	2017	=head1 ERROR AND EXCEPTION HANDLING
1515		2018
1516	In general, AnyEvent does not do any error handling - it relies on the	2019	In general, AnyEvent does not do any error handling - it relies on the
1517	caller to do that if required. The L<AnyEvent::Strict> module (see also	2020	caller to do that if required. The L<AnyEvent::Strict> module (see also
…		…
1529	$Event/EV::DIED->() >>, L<Glib> uses C<< install_exception_handler >> and	2032	$Event/EV::DIED->() >>, L<Glib> uses C<< install_exception_handler >> and
1530	so on.	2033	so on.
1531		2034
1532	=head1 ENVIRONMENT VARIABLES	2035	=head1 ENVIRONMENT VARIABLES
1533		2036
1534	The following environment variables are used by this module or its	2037	AnyEvent supports a number of environment variables that tune the
1535	submodules.	2038	runtime behaviour. They are usually evaluated when AnyEvent is
		2039	loaded, initialised, or a submodule that uses them is loaded. Many of
		2040	them also cause AnyEvent to load additional modules - for example,
		2041	C<PERL_ANYEVENT_DEBUG_WRAP> causes the L<AnyEvent::Debug> module to be
		2042	loaded.
1536		2043
1537	Note that AnyEvent will remove I<all> environment variables starting with	2044	All the environment variables documented here start with
1538	C<PERL_ANYEVENT_> from C<%ENV> when it is loaded while taint mode is	2045	C<PERL_ANYEVENT_>, which is what AnyEvent considers its own
1539	enabled.	2046	namespace. Other modules are encouraged (but by no means required) to use
		2047	C<PERL_ANYEVENT_SUBMODULE> if they have registered the AnyEvent::Submodule
		2048	namespace on CPAN, for any submodule. For example, L<AnyEvent::HTTP> could
		2049	be expected to use C<PERL_ANYEVENT_HTTP_PROXY> (it should not access env
		2050	variables starting with C<AE_>, see below).
		2051
		2052	All variables can also be set via the C<AE_> prefix, that is, instead
		2053	of setting C<PERL_ANYEVENT_VERBOSE> you can also set C<AE_VERBOSE>. In
		2054	case there is a clash btween anyevent and another program that uses
		2055	C<AE_something> you can set the corresponding C<PERL_ANYEVENT_something>
		2056	variable to the empty string, as those variables take precedence.
		2057
		2058	When AnyEvent is first loaded, it copies all C<AE_xxx> env variables
		2059	to their C<PERL_ANYEVENT_xxx> counterpart unless that variable already
		2060	exists. If taint mode is on, then AnyEvent will remove I<all> environment
		2061	variables starting with C<PERL_ANYEVENT_> from C<%ENV> (or replace them
		2062	with C<undef> or the empty string, if the corresaponding C<AE_> variable
		2063	is set).
		2064
		2065	The exact algorithm is currently:
		2066
		2067	1. if taint mode enabled, delete all PERL_ANYEVENT_xyz variables from %ENV
		2068	2. copy over AE_xyz to PERL_ANYEVENT_xyz unless the latter alraedy exists
		2069	3. if taint mode enabled, set all PERL_ANYEVENT_xyz variables to undef.
		2070
		2071	This ensures that child processes will not see the C<AE_> variables.
		2072
		2073	The following environment variables are currently known to AnyEvent:
1540		2074
1541	=over 4	2075	=over 4
1542		2076
1543	=item C<PERL_ANYEVENT_VERBOSE>	2077	=item C<PERL_ANYEVENT_VERBOSE>
1544		2078
1545	By default, AnyEvent will be completely silent except in fatal	2079	By default, AnyEvent will log messages with loglevel C<4> (C<error>) or
1546	conditions. You can set this environment variable to make AnyEvent more	2080	higher (see L<AnyEvent::Log>). You can set this environment variable to a
1547	talkative.	2081	numerical loglevel to make AnyEvent more (or less) talkative.
1548		2082
		2083	If you want to do more than just set the global logging level
		2084	you should have a look at C<PERL_ANYEVENT_LOG>, which allows much more
		2085	complex specifications.
		2086
		2087	When set to C<0> (C<off>), then no messages whatsoever will be logged with
		2088	everything else at defaults.
		2089
1549	When set to C<1> or higher, causes AnyEvent to warn about unexpected	2090	When set to C<5> or higher (C<warn>), AnyEvent warns about unexpected
1550	conditions, such as not being able to load the event model specified by	2091	conditions, such as not being able to load the event model specified by
1551	C<PERL_ANYEVENT_MODEL>.	2092	C<PERL_ANYEVENT_MODEL>, or a guard callback throwing an exception - this
		2093	is the minimum recommended level for use during development.
1552		2094
1553	When set to C<2> or higher, cause AnyEvent to report to STDERR which event	2095	When set to C<7> or higher (info), AnyEvent reports which event model it
1554	model it chooses.	2096	chooses.
		2097
		2098	When set to C<8> or higher (debug), then AnyEvent will report extra
		2099	information on which optional modules it loads and how it implements
		2100	certain features.
		2101
		2102	=item C<PERL_ANYEVENT_LOG>
		2103
		2104	Accepts rather complex logging specifications. For example, you could log
		2105	all C<debug> messages of some module to stderr, warnings and above to
		2106	stderr, and errors and above to syslog, with:
		2107
		2108	PERL_ANYEVENT_LOG=Some::Module=debug,+log:filter=warn,+%syslog:%syslog=error,syslog
		2109
		2110	For the rather extensive details, see L<AnyEvent::Log>.
		2111
		2112	This variable is evaluated when AnyEvent (or L<AnyEvent::Log>) is loaded,
		2113	so will take effect even before AnyEvent has initialised itself.
		2114
		2115	Note that specifying this environment variable causes the L<AnyEvent::Log>
		2116	module to be loaded, while C<PERL_ANYEVENT_VERBOSE> does not, so only
		2117	using the latter saves a few hundred kB of memory unless a module
		2118	explicitly needs the extra features of AnyEvent::Log.
1555		2119
1556	=item C<PERL_ANYEVENT_STRICT>	2120	=item C<PERL_ANYEVENT_STRICT>
1557		2121
1558	AnyEvent does not do much argument checking by default, as thorough	2122	AnyEvent does not do much argument checking by default, as thorough
1559	argument checking is very costly. Setting this variable to a true value	2123	argument checking is very costly. Setting this variable to a true value
…		…
1561	check the arguments passed to most method calls. If it finds any problems,	2125	check the arguments passed to most method calls. If it finds any problems,
1562	it will croak.	2126	it will croak.
1563		2127
1564	In other words, enables "strict" mode.	2128	In other words, enables "strict" mode.
1565		2129
1566	Unlike C<use strict>, it is definitely recommended to keep it off in	2130	Unlike C<use strict> (or its modern cousin, C<< use L<common::sense>
1567	production. Keeping C<PERL_ANYEVENT_STRICT=1> in your environment while	2131	>>, it is definitely recommended to keep it off in production. Keeping
1568	developing programs can be very useful, however.	2132	C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs
		2133	can be very useful, however.
		2134
		2135	=item C<PERL_ANYEVENT_DEBUG_SHELL>
		2136
		2137	If this env variable is nonempty, then its contents will be interpreted by
		2138	C<AnyEvent::Socket::parse_hostport> and C<AnyEvent::Debug::shell> (after
		2139	replacing every occurance of C<$$> by the process pid). The shell object
		2140	is saved in C<$AnyEvent::Debug::SHELL>.
		2141
		2142	This happens when the first watcher is created.
		2143
		2144	For example, to bind a debug shell on a unix domain socket in
		2145	F<< /tmp/debug<pid>.sock >>, you could use this:
		2146
		2147	PERL_ANYEVENT_DEBUG_SHELL=/tmp/debug\$\$.sock perlprog
		2148	# connect with e.g.: socat readline /tmp/debug123.sock
		2149
		2150	Or to bind to tcp port 4545 on localhost:
		2151
		2152	PERL_ANYEVENT_DEBUG_SHELL=127.0.0.1:4545 perlprog
		2153	# connect with e.g.: telnet localhost 4545
		2154
		2155	Note that creating sockets in F</tmp> or on localhost is very unsafe on
		2156	multiuser systems.
		2157
		2158	=item C<PERL_ANYEVENT_DEBUG_WRAP>
		2159
		2160	Can be set to C<0>, C<1> or C<2> and enables wrapping of all watchers for
		2161	debugging purposes. See C<AnyEvent::Debug::wrap> for details.
1569		2162
1570	=item C<PERL_ANYEVENT_MODEL>	2163	=item C<PERL_ANYEVENT_MODEL>
1571		2164
1572	This can be used to specify the event model to be used by AnyEvent, before	2165	This can be used to specify the event model to be used by AnyEvent, before
1573	auto detection and -probing kicks in. It must be a string consisting	2166	auto detection and -probing kicks in.
1574	entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended	2167
		2168	It normally is a string consisting entirely of ASCII letters (e.g. C<EV>
		2169	or C<IOAsync>). The string C<AnyEvent::Impl::> gets prepended and the
1575	and the resulting module name is loaded and if the load was successful,	2170	resulting module name is loaded and - if the load was successful - used as
1576	used as event model. If it fails to load AnyEvent will proceed with	2171	event model backend. If it fails to load then AnyEvent will proceed with
1577	auto detection and -probing.	2172	auto detection and -probing.
1578		2173
1579	This functionality might change in future versions.	2174	If the string ends with C<::> instead (e.g. C<AnyEvent::Impl::EV::>) then
		2175	nothing gets prepended and the module name is used as-is (hint: C<::> at
		2176	the end of a string designates a module name and quotes it appropriately).
1580		2177
1581	For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you	2178	For example, to force the pure perl model (L<AnyEvent::Loop::Perl>) you
1582	could start your program like this:	2179	could start your program like this:
1583		2180
1584	PERL_ANYEVENT_MODEL=Perl perl ...	2181	PERL_ANYEVENT_MODEL=Perl perl ...
1585		2182
1586	=item C<PERL_ANYEVENT_PROTOCOLS>	2183	=item C<PERL_ANYEVENT_PROTOCOLS>
…		…
1602	but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4>	2199	but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4>
1603	- only support IPv4, never try to resolve or contact IPv6	2200	- only support IPv4, never try to resolve or contact IPv6
1604	addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or	2201	addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or
1605	IPv6, but prefer IPv6 over IPv4.	2202	IPv6, but prefer IPv6 over IPv4.
1606		2203
		2204	=item C<PERL_ANYEVENT_HOSTS>
		2205
		2206	This variable, if specified, overrides the F</etc/hosts> file used by
		2207	L<AnyEvent::Socket>C<::resolve_sockaddr>, i.e. hosts aliases will be read
		2208	from that file instead.
		2209
1607	=item C<PERL_ANYEVENT_EDNS0>	2210	=item C<PERL_ANYEVENT_EDNS0>
1608		2211
1609	Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension	2212	Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension for
1610	for DNS. This extension is generally useful to reduce DNS traffic, but	2213	DNS. This extension is generally useful to reduce DNS traffic, especially
1611	some (broken) firewalls drop such DNS packets, which is why it is off by	2214	when DNSSEC is involved, but some (broken) firewalls drop such DNS
1612	default.	2215	packets, which is why it is off by default.
1613		2216
1614	Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce	2217	Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce
1615	EDNS0 in its DNS requests.	2218	EDNS0 in its DNS requests.
1616		2219
1617	=item C<PERL_ANYEVENT_MAX_FORKS>	2220	=item C<PERL_ANYEVENT_MAX_FORKS>
…		…
1623		2226
1624	The default value for the C<max_outstanding> parameter for the default DNS	2227	The default value for the C<max_outstanding> parameter for the default DNS
1625	resolver - this is the maximum number of parallel DNS requests that are	2228	resolver - this is the maximum number of parallel DNS requests that are
1626	sent to the DNS server.	2229	sent to the DNS server.
1627		2230
		2231	=item C<PERL_ANYEVENT_MAX_SIGNAL_LATENCY>
		2232
		2233	Perl has inherently racy signal handling (you can basically choose between
		2234	losing signals and memory corruption) - pure perl event loops (including
		2235	C<AnyEvent::Loop>, when C<Async::Interrupt> isn't available) therefore
		2236	have to poll regularly to avoid losing signals.
		2237
		2238	Some event loops are racy, but don't poll regularly, and some event loops
		2239	are written in C but are still racy. For those event loops, AnyEvent
		2240	installs a timer that regularly wakes up the event loop.
		2241
		2242	By default, the interval for this timer is C<10> seconds, but you can
		2243	override this delay with this environment variable (or by setting
		2244	the C<$AnyEvent::MAX_SIGNAL_LATENCY> variable before creating signal
		2245	watchers).
		2246
		2247	Lower values increase CPU (and energy) usage, higher values can introduce
		2248	long delays when reaping children or waiting for signals.
		2249
		2250	The L<AnyEvent::Async> module, if available, will be used to avoid this
		2251	polling (with most event loops).
		2252
1628	=item C<PERL_ANYEVENT_RESOLV_CONF>	2253	=item C<PERL_ANYEVENT_RESOLV_CONF>
1629		2254
1630	The file to use instead of F</etc/resolv.conf> (or OS-specific	2255	The absolute path to a F<resolv.conf>-style file to use instead of
1631	configuration) in the default resolver. When set to the empty string, no	2256	F</etc/resolv.conf> (or the OS-specific configuration) in the default
1632	default config will be used.	2257	resolver, or the empty string to select the default configuration.
1633		2258
1634	=item C<PERL_ANYEVENT_CA_FILE>, C<PERL_ANYEVENT_CA_PATH>.	2259	=item C<PERL_ANYEVENT_CA_FILE>, C<PERL_ANYEVENT_CA_PATH>.
1635		2260
1636	When neither C<ca_file> nor C<ca_path> was specified during	2261	When neither C<ca_file> nor C<ca_path> was specified during
1637	L<AnyEvent::TLS> context creation, and either of these environment	2262	L<AnyEvent::TLS> context creation, and either of these environment
1638	variables exist, they will be used to specify CA certificate locations	2263	variables are nonempty, they will be used to specify CA certificate
1639	instead of a system-dependent default.	2264	locations instead of a system-dependent default.
		2265
		2266	=item C<PERL_ANYEVENT_AVOID_GUARD> and C<PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT>
		2267
		2268	When these are set to C<1>, then the respective modules are not
		2269	loaded. Mostly good for testing AnyEvent itself.
1640		2270
1641	=back	2271	=back
1642		2272
1643	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE	2273	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE
1644		2274
…		…
1702	warn "read: $input\n"; # output what has been read	2332	warn "read: $input\n"; # output what has been read
1703	$cv->send if $input =~ /^q/i; # quit program if /^q/i	2333	$cv->send if $input =~ /^q/i; # quit program if /^q/i
1704	},	2334	},
1705	);	2335	);
1706		2336
1707	my $time_watcher; # can only be used once
1708
1709	sub new_timer {
1710	$timer = AnyEvent->timer (after => 1, cb => sub {	2337	my $time_watcher = AnyEvent->timer (after => 1, interval => 1, cb => sub {
1711	warn "timeout\n"; # print 'timeout' about every second	2338	warn "timeout\n"; # print 'timeout' at most every second
1712	&new_timer; # and restart the time
1713	});	2339	});
1714	}
1715
1716	new_timer; # create first timer
1717		2340
1718	$cv->recv; # wait until user enters /^q/i	2341	$cv->recv; # wait until user enters /^q/i
1719		2342
1720	=head1 REAL-WORLD EXAMPLE	2343	=head1 REAL-WORLD EXAMPLE
1721		2344
…		…
1794		2417
1795	The actual code goes further and collects all errors (C<die>s, exceptions)	2418	The actual code goes further and collects all errors (C<die>s, exceptions)
1796	that occurred during request processing. The C<result> method detects	2419	that occurred during request processing. The C<result> method detects
1797	whether an exception as thrown (it is stored inside the $txn object)	2420	whether an exception as thrown (it is stored inside the $txn object)
1798	and just throws the exception, which means connection errors and other	2421	and just throws the exception, which means connection errors and other
1799	problems get reported tot he code that tries to use the result, not in a	2422	problems get reported to the code that tries to use the result, not in a
1800	random callback.	2423	random callback.
1801		2424
1802	All of this enables the following usage styles:	2425	All of this enables the following usage styles:
1803		2426
1804	1. Blocking:	2427	1. Blocking:
…		…
1852	through AnyEvent. The benchmark creates a lot of timers (with a zero	2475	through AnyEvent. The benchmark creates a lot of timers (with a zero
1853	timeout) and I/O watchers (watching STDOUT, a pty, to become writable,	2476	timeout) and I/O watchers (watching STDOUT, a pty, to become writable,
1854	which it is), lets them fire exactly once and destroys them again.	2477	which it is), lets them fire exactly once and destroys them again.
1855		2478
1856	Source code for this benchmark is found as F<eg/bench> in the AnyEvent	2479	Source code for this benchmark is found as F<eg/bench> in the AnyEvent
1857	distribution.	2480	distribution. It uses the L<AE> interface, which makes a real difference
		2481	for the EV and Perl backends only.
1858		2482
1859	=head3 Explanation of the columns	2483	=head3 Explanation of the columns
1860		2484
1861	I<watcher> is the number of event watchers created/destroyed. Since	2485	I<watcher> is the number of event watchers created/destroyed. Since
1862	different event models feature vastly different performances, each event	2486	different event models feature vastly different performances, each event
…		…
1883	watcher.	2507	watcher.
1884		2508
1885	=head3 Results	2509	=head3 Results
1886		2510
1887	name watchers bytes create invoke destroy comment	2511	name watchers bytes create invoke destroy comment
1888	EV/EV 400000 224 0.47 0.35 0.27 EV native interface	2512	EV/EV 100000 223 0.47 0.43 0.27 EV native interface
1889	EV/Any 100000 224 2.88 0.34 0.27 EV + AnyEvent watchers	2513	EV/Any 100000 223 0.48 0.42 0.26 EV + AnyEvent watchers
1890	CoroEV/Any 100000 224 2.85 0.35 0.28 coroutines + Coro::Signal	2514	Coro::EV/Any 100000 223 0.47 0.42 0.26 coroutines + Coro::Signal
1891	Perl/Any 100000 452 4.13 0.73 0.95 pure perl implementation	2515	Perl/Any 100000 431 2.70 0.74 0.92 pure perl implementation
1892	Event/Event 16000 517 32.20 31.80 0.81 Event native interface	2516	Event/Event 16000 516 31.16 31.84 0.82 Event native interface
1893	Event/Any 16000 590 35.85 31.55 1.06 Event + AnyEvent watchers	2517	Event/Any 16000 1203 42.61 34.79 1.80 Event + AnyEvent watchers
1894	IOAsync/Any 16000 989 38.10 32.77 11.13 via IO::Async::Loop::IO_Poll	2518	IOAsync/Any 16000 1911 41.92 27.45 16.81 via IO::Async::Loop::IO_Poll
1895	IOAsync/Any 16000 990 37.59 29.50 10.61 via IO::Async::Loop::Epoll	2519	IOAsync/Any 16000 1726 40.69 26.37 15.25 via IO::Async::Loop::Epoll
1896	Glib/Any 16000 1357 102.33 12.31 51.00 quadratic behaviour	2520	Glib/Any 16000 1118 89.00 12.57 51.17 quadratic behaviour
1897	Tk/Any 2000 1860 27.20 66.31 14.00 SEGV with >> 2000 watchers	2521	Tk/Any 2000 1346 20.96 10.75 8.00 SEGV with >> 2000 watchers
1898	POE/Event 2000 6328 109.99 751.67 14.02 via POE::Loop::Event	2522	POE/Any 2000 6951 108.97 795.32 14.24 via POE::Loop::Event
1899	POE/Select 2000 6027 94.54 809.13 579.80 via POE::Loop::Select	2523	POE/Any 2000 6648 94.79 774.40 575.51 via POE::Loop::Select
1900		2524
1901	=head3 Discussion	2525	=head3 Discussion
1902		2526
1903	The benchmark does I<not> measure scalability of the event loop very	2527	The benchmark does I<not> measure scalability of the event loop very
1904	well. For example, a select-based event loop (such as the pure perl one)	2528	well. For example, a select-based event loop (such as the pure perl one)
…		…
1916	benchmark machine, handling an event takes roughly 1600 CPU cycles with	2540	benchmark machine, handling an event takes roughly 1600 CPU cycles with
1917	EV, 3100 CPU cycles with AnyEvent's pure perl loop and almost 3000000 CPU	2541	EV, 3100 CPU cycles with AnyEvent's pure perl loop and almost 3000000 CPU
1918	cycles with POE.	2542	cycles with POE.
1919		2543
1920	C<EV> is the sole leader regarding speed and memory use, which are both	2544	C<EV> is the sole leader regarding speed and memory use, which are both
1921	maximal/minimal, respectively. Even when going through AnyEvent, it uses	2545	maximal/minimal, respectively. When using the L<AE> API there is zero
		2546	overhead (when going through the AnyEvent API create is about 5-6 times
		2547	slower, with other times being equal, so still uses far less memory than
1922	far less memory than any other event loop and is still faster than Event	2548	any other event loop and is still faster than Event natively).
1923	natively.
1924		2549
1925	The pure perl implementation is hit in a few sweet spots (both the	2550	The pure perl implementation is hit in a few sweet spots (both the
1926	constant timeout and the use of a single fd hit optimisations in the perl	2551	constant timeout and the use of a single fd hit optimisations in the perl
1927	interpreter and the backend itself). Nevertheless this shows that it	2552	interpreter and the backend itself). Nevertheless this shows that it
1928	adds very little overhead in itself. Like any select-based backend its	2553	adds very little overhead in itself. Like any select-based backend its
…		…
1976	(even when used without AnyEvent), but most event loops have acceptable	2601	(even when used without AnyEvent), but most event loops have acceptable
1977	performance with or without AnyEvent.	2602	performance with or without AnyEvent.
1978		2603
1979	=item * The overhead AnyEvent adds is usually much smaller than the overhead of	2604	=item * The overhead AnyEvent adds is usually much smaller than the overhead of
1980	the actual event loop, only with extremely fast event loops such as EV	2605	the actual event loop, only with extremely fast event loops such as EV
1981	adds AnyEvent significant overhead.	2606	does AnyEvent add significant overhead.
1982		2607
1983	=item * You should avoid POE like the plague if you want performance or	2608	=item * You should avoid POE like the plague if you want performance or
1984	reasonable memory usage.	2609	reasonable memory usage.
1985		2610
1986	=back	2611	=back
…		…
2002	In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100	2627	In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100
2003	(1%) are active. This mirrors the activity of large servers with many	2628	(1%) are active. This mirrors the activity of large servers with many
2004	connections, most of which are idle at any one point in time.	2629	connections, most of which are idle at any one point in time.
2005		2630
2006	Source code for this benchmark is found as F<eg/bench2> in the AnyEvent	2631	Source code for this benchmark is found as F<eg/bench2> in the AnyEvent
2007	distribution.	2632	distribution. It uses the L<AE> interface, which makes a real difference
		2633	for the EV and Perl backends only.
2008		2634
2009	=head3 Explanation of the columns	2635	=head3 Explanation of the columns
2010		2636
2011	I<sockets> is the number of sockets, and twice the number of "servers" (as	2637	I<sockets> is the number of sockets, and twice the number of "servers" (as
2012	each server has a read and write socket end).	2638	each server has a read and write socket end).
…		…
2020	a new one that moves the timeout into the future.	2646	a new one that moves the timeout into the future.
2021		2647
2022	=head3 Results	2648	=head3 Results
2023		2649
2024	name sockets create request	2650	name sockets create request
2025	EV 20000 69.01 11.16	2651	EV 20000 62.66 7.99
2026	Perl 20000 73.32 35.87	2652	Perl 20000 68.32 32.64
2027	IOAsync 20000 157.00 98.14 epoll	2653	IOAsync 20000 174.06 101.15 epoll
2028	IOAsync 20000 159.31 616.06 poll	2654	IOAsync 20000 174.67 610.84 poll
2029	Event 20000 212.62 257.32	2655	Event 20000 202.69 242.91
2030	Glib 20000 651.16 1896.30	2656	Glib 20000 557.01 1689.52
2031	POE 20000 349.67 12317.24 uses POE::Loop::Event	2657	POE 20000 341.54 12086.32 uses POE::Loop::Event
2032		2658
2033	=head3 Discussion	2659	=head3 Discussion
2034		2660
2035	This benchmark I<does> measure scalability and overall performance of the	2661	This benchmark I<does> measure scalability and overall performance of the
2036	particular event loop.	2662	particular event loop.
…		…
2162	As you can see, the AnyEvent + EV combination even beats the	2788	As you can see, the AnyEvent + EV combination even beats the
2163	hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl	2789	hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl
2164	backend easily beats IO::Lambda and POE.	2790	backend easily beats IO::Lambda and POE.
2165		2791
2166	And even the 100% non-blocking version written using the high-level (and	2792	And even the 100% non-blocking version written using the high-level (and
2167	slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda by a	2793	slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda
2168	large margin, even though it does all of DNS, tcp-connect and socket I/O	2794	higher level ("unoptimised") abstractions by a large margin, even though
2169	in a non-blocking way.	2795	it does all of DNS, tcp-connect and socket I/O in a non-blocking way.
2170		2796
2171	The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and	2797	The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and
2172	F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are	2798	F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are
2173	part of the IO::lambda distribution and were used without any changes.	2799	part of the IO::Lambda distribution and were used without any changes.
2174		2800
2175		2801
2176	=head1 SIGNALS	2802	=head1 SIGNALS
2177		2803
2178	AnyEvent currently installs handlers for these signals:	2804	AnyEvent currently installs handlers for these signals:
…		…
2215	unless defined $SIG{PIPE};	2841	unless defined $SIG{PIPE};
2216		2842
2217	=head1 RECOMMENDED/OPTIONAL MODULES	2843	=head1 RECOMMENDED/OPTIONAL MODULES
2218		2844
2219	One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and	2845	One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and
2220	it's built-in modules) are required to use it.	2846	its built-in modules) are required to use it.
2221		2847
2222	That does not mean that AnyEvent won't take advantage of some additional	2848	That does not mean that AnyEvent won't take advantage of some additional
2223	modules if they are installed.	2849	modules if they are installed.
2224		2850
2225	This section epxlains which additional modules will be used, and how they	2851	This section explains which additional modules will be used, and how they
2226	affect AnyEvent's operetion.	2852	affect AnyEvent's operation.
2227		2853
2228	=over 4	2854	=over 4
2229		2855
2230	=item L<Async::Interrupt>	2856	=item L<Async::Interrupt>
2231		2857
2232	This slightly arcane module is used to implement fast signal handling: To	2858	This slightly arcane module is used to implement fast signal handling: To
2233	my knowledge, there is no way to do completely race-free and quick	2859	my knowledge, there is no way to do completely race-free and quick
2234	signal handling in pure perl. To ensure that signals still get	2860	signal handling in pure perl. To ensure that signals still get
2235	delivered, AnyEvent will start an interval timer to wake up perl (and	2861	delivered, AnyEvent will start an interval timer to wake up perl (and
2236	catch the signals) with soemd elay (default is 10 seconds, look for	2862	catch the signals) with some delay (default is 10 seconds, look for
2237	C<$AnyEvent::MAX_SIGNAL_LATENCY>).	2863	C<$AnyEvent::MAX_SIGNAL_LATENCY>).
2238		2864
2239	If this module is available, then it will be used to implement signal	2865	If this module is available, then it will be used to implement signal
2240	catching, which means that signals will not be delayed, and the event loop	2866	catching, which means that signals will not be delayed, and the event loop
2241	will not be interrupted regularly, which is more efficient (And good for	2867	will not be interrupted regularly, which is more efficient (and good for
2242	battery life on laptops).	2868	battery life on laptops).
2243		2869
2244	This affects not just the pure-perl event loop, but also other event loops	2870	This affects not just the pure-perl event loop, but also other event loops
2245	that have no signal handling on their own (e.g. Glib, Tk, Qt).	2871	that have no signal handling on their own (e.g. Glib, Tk, Qt).
		2872
		2873	Some event loops (POE, Event, Event::Lib) offer signal watchers natively,
		2874	and either employ their own workarounds (POE) or use AnyEvent's workaround
		2875	(using C<$AnyEvent::MAX_SIGNAL_LATENCY>). Installing L<Async::Interrupt>
		2876	does nothing for those backends.
2246		2877
2247	=item L<EV>	2878	=item L<EV>
2248		2879
2249	This module isn't really "optional", as it is simply one of the backend	2880	This module isn't really "optional", as it is simply one of the backend
2250	event loops that AnyEvent can use. However, it is simply the best event	2881	event loops that AnyEvent can use. However, it is simply the best event
…		…
2253	automatic timer adjustments even when no monotonic clock is available,	2884	automatic timer adjustments even when no monotonic clock is available,
2254	can take avdantage of advanced kernel interfaces such as C<epoll> and	2885	can take avdantage of advanced kernel interfaces such as C<epoll> and
2255	C<kqueue>, and is the fastest backend I<by far>. You can even embed	2886	C<kqueue>, and is the fastest backend I<by far>. You can even embed
2256	L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>).	2887	L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>).
2257		2888
		2889	If you only use backends that rely on another event loop (e.g. C<Tk>),
		2890	then this module will do nothing for you.
		2891
2258	=item L<Guard>	2892	=item L<Guard>
2259		2893
2260	The guard module, when used, will be used to implement	2894	The guard module, when used, will be used to implement
2261	C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a	2895	C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a
2262	lot less memory), but otherwise doesn't affect guard operation much. It is	2896	lot less memory), but otherwise doesn't affect guard operation much. It is
2263	purely used for performance.	2897	purely used for performance.
2264		2898
2265	=item L<JSON> and L<JSON::XS>	2899	=item L<JSON> and L<JSON::XS>
2266		2900
2267	This module is required when you want to read or write JSON data via	2901	One of these modules is required when you want to read or write JSON data
2268	L<AnyEvent::Handle>. It is also written in pure-perl, but can take	2902	via L<AnyEvent::Handle>. L<JSON> is also written in pure-perl, but can take
2269	advantage of the ulta-high-speed L<JSON::XS> module when it is installed.	2903	advantage of the ultra-high-speed L<JSON::XS> module when it is installed.
2270
2271	In fact, L<AnyEvent::Handle> will use L<JSON::XS> by default if it is
2272	installed.
2273		2904
2274	=item L<Net::SSLeay>	2905	=item L<Net::SSLeay>
2275		2906
2276	Implementing TLS/SSL in Perl is certainly interesting, but not very	2907	Implementing TLS/SSL in Perl is certainly interesting, but not very
2277	worthwhile: If this module is installed, then L<AnyEvent::Handle> (with	2908	worthwhile: If this module is installed, then L<AnyEvent::Handle> (with
2278	the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL.	2909	the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL.
2279		2910
2280	=item L<Time::HiRes>	2911	=item L<Time::HiRes>
2281		2912
2282	This module is part of perl since release 5.008. It will be used when the	2913	This module is part of perl since release 5.008. It will be used when the
2283	chosen event library does not come with a timing source on it's own. The	2914	chosen event library does not come with a timing source of its own. The
2284	pure-perl event loop (L<AnyEvent::Impl::Perl>) will additionally use it to	2915	pure-perl event loop (L<AnyEvent::Loop>) will additionally load it to
2285	try to use a monotonic clock for timing stability.	2916	try to use a monotonic clock for timing stability.
2286		2917
2287	=back	2918	=back
2288		2919
2289		2920
2290	=head1 FORK	2921	=head1 FORK
2291		2922
2292	Most event libraries are not fork-safe. The ones who are usually are	2923	Most event libraries are not fork-safe. The ones who are usually are
2293	because they rely on inefficient but fork-safe C<select> or C<poll>	2924	because they rely on inefficient but fork-safe C<select> or C<poll> calls
2294	calls. Only L<EV> is fully fork-aware.	2925	- higher performance APIs such as BSD's kqueue or the dreaded Linux epoll
		2926	are usually badly thought-out hacks that are incompatible with fork in
		2927	one way or another. Only L<EV> is fully fork-aware and ensures that you
		2928	continue event-processing in both parent and child (or both, if you know
		2929	what you are doing).
		2930
		2931	This means that, in general, you cannot fork and do event processing in
		2932	the child if the event library was initialised before the fork (which
		2933	usually happens when the first AnyEvent watcher is created, or the library
		2934	is loaded).
2295		2935
2296	If you have to fork, you must either do so I<before> creating your first	2936	If you have to fork, you must either do so I<before> creating your first
2297	watcher OR you must not use AnyEvent at all in the child OR you must do	2937	watcher OR you must not use AnyEvent at all in the child OR you must do
2298	something completely out of the scope of AnyEvent.	2938	something completely out of the scope of AnyEvent.
		2939
		2940	The problem of doing event processing in the parent I<and> the child
		2941	is much more complicated: even for backends that I<are> fork-aware or
		2942	fork-safe, their behaviour is not usually what you want: fork clones all
		2943	watchers, that means all timers, I/O watchers etc. are active in both
		2944	parent and child, which is almost never what you want. USing C<exec>
		2945	to start worker children from some kind of manage rprocess is usually
		2946	preferred, because it is much easier and cleaner, at the expense of having
		2947	to have another binary.
2299		2948
2300		2949
2301	=head1 SECURITY CONSIDERATIONS	2950	=head1 SECURITY CONSIDERATIONS
2302		2951
2303	AnyEvent can be forced to load any event model via	2952	AnyEvent can be forced to load any event model via
…		…
2333	pronounced).	2982	pronounced).
2334		2983
2335		2984
2336	=head1 SEE ALSO	2985	=head1 SEE ALSO
2337		2986
2338	Utility functions: L<AnyEvent::Util>.	2987	Tutorial/Introduction: L<AnyEvent::Intro>.
2339		2988
2340	Event modules: L<EV>, L<EV::Glib>, L<Glib::EV>, L<Event>, L<Glib::Event>,	2989	FAQ: L<AnyEvent::FAQ>.
2341	L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.	2990
		2991	Utility functions: L<AnyEvent::Util> (misc. grab-bag), L<AnyEvent::Log>
		2992	(simply logging).
		2993
		2994	Development/Debugging: L<AnyEvent::Strict> (stricter checking),
		2995	L<AnyEvent::Debug> (interactive shell, watcher tracing).
		2996
		2997	Supported event modules: L<AnyEvent::Loop>, L<EV>, L<EV::Glib>,
		2998	L<Glib::EV>, L<Event>, L<Glib::Event>, L<Glib>, L<Tk>, L<Event::Lib>,
		2999	L<Qt>, L<POE>, L<FLTK>.
2342		3000
2343	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,	3001	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,
2344	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,	3002	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,
2345	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,	3003	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,
2346	L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>.	3004	L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>, L<Anyevent::Impl::Irssi>,
		3005	L<AnyEvent::Impl::FLTK>.
2347		3006
2348	Non-blocking file handles, sockets, TCP clients and	3007	Non-blocking handles, pipes, stream sockets, TCP clients and
2349	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.	3008	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.
2350		3009
2351	Asynchronous DNS: L<AnyEvent::DNS>.	3010	Asynchronous DNS: L<AnyEvent::DNS>.
2352		3011
2353	Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>,	3012	Thread support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>.
2354	L<Coro::Event>,
2355		3013
2356	Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::XMPP>,	3014	Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::IRC>,
2357	L<AnyEvent::HTTP>.	3015	L<AnyEvent::HTTP>.
2358		3016
2359		3017
2360	=head1 AUTHOR	3018	=head1 AUTHOR
2361		3019

Diff Legend

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