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Revision 1.259 by root, Tue Jul 28 02:07:18 2009 UTC vs.
Revision 1.406 by root, Thu Nov 15 01:17:29 2012 UTC

1	=head1 NAME	1	=head1 NAME
2		2
3	AnyEvent - the DBI of event loop programming	3	AnyEvent - the DBI of event loop programming
4		4
5	EV, Event, Glib, Tk, Perl, Event::Lib, Irssi, rxvt-unicode, IO::Async, Qt	5	EV, Event, Glib, Tk, Perl, Event::Lib, Irssi, rxvt-unicode, IO::Async, Qt,
6	and POE are various supported event loops/environments.	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
…		…
43	in a tutorial or some gentle introduction, have a look at the	46	in a tutorial or some gentle introduction, have a look at the
44	L<AnyEvent::Intro> manpage.	47	L<AnyEvent::Intro> manpage.
45		48
46	=head1 SUPPORT	49	=head1 SUPPORT
47		50
		51	An FAQ document is available as L<AnyEvent::FAQ>.
		52
48	There is a mailinglist for discussing all things AnyEvent, and an IRC	53	There also is a mailinglist for discussing all things AnyEvent, and an IRC
49	channel, too.	54	channel, too.
50		55
51	See the AnyEvent project page at the B<Schmorpforge Ta-Sa Software	56	See the AnyEvent project page at the B<Schmorpforge Ta-Sa Software
52	Repository>, at L<http://anyevent.schmorp.de>, for more info.	57	Repository>, at L<http://anyevent.schmorp.de>, for more info.
53		58
…		…
73	module users into the same thing by forcing them to use the same event	78	module users into the same thing by forcing them to use the same event
74	model you use.	79	model you use.
75		80
76	For modules like POE or IO::Async (which is a total misnomer as it is	81	For modules like POE or IO::Async (which is a total misnomer as it is
77	actually doing all I/O I<synchronously>...), using them in your module is	82	actually doing all I/O I<synchronously>...), using them in your module is
78	like joining a cult: After you joined, you are dependent on them and you	83	like joining a cult: After you join, you are dependent on them and you
79	cannot use anything else, as they are simply incompatible to everything	84	cannot use anything else, as they are simply incompatible to everything
80	that isn't them. What's worse, all the potential users of your	85	that isn't them. What's worse, all the potential users of your
81	module are I<also> forced to use the same event loop you use.	86	module are I<also> forced to use the same event loop you use.
82		87
83	AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works	88	AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works
84	fine. AnyEvent + Tk works fine etc. etc. but none of these work together	89	fine. AnyEvent + Tk works fine etc. etc. but none of these work together
85	with the rest: POE + IO::Async? No go. Tk + Event? No go. Again: if	90	with the rest: POE + EV? No go. Tk + Event? No go. Again: if your module
86	your module uses one of those, every user of your module has to use it,	91	uses one of those, every user of your module has to use it, too. But if
87	too. But if your module uses AnyEvent, it works transparently with all	92	your module uses AnyEvent, it works transparently with all event models it
88	event models it supports (including stuff like IO::Async, as long as those	93	supports (including stuff like IO::Async, as long as those use one of the
89	use one of the supported event loops. It is trivial to add new event loops	94	supported event loops. It is easy to add new event loops to AnyEvent, too,
90	to AnyEvent, too, so it is future-proof).	95	so it is future-proof).
91		96
92	In addition to being free of having to use I<the one and only true event	97	In addition to being free of having to use I<the one and only true event
93	model>, AnyEvent also is free of bloat and policy: with POE or similar	98	model>, AnyEvent also is free of bloat and policy: with POE or similar
94	modules, you get an enormous amount of code and strict rules you have to	99	modules, you get an enormous amount of code and strict rules you have to
95	follow. AnyEvent, on the other hand, is lean and up to the point, by only	100	follow. AnyEvent, on the other hand, is lean and to the point, by only
96	offering the functionality that is necessary, in as thin as a wrapper as	101	offering the functionality that is necessary, in as thin as a wrapper as
97	technically possible.	102	technically possible.
98		103
99	Of course, AnyEvent comes with a big (and fully optional!) toolbox	104	Of course, AnyEvent comes with a big (and fully optional!) toolbox
100	of useful functionality, such as an asynchronous DNS resolver, 100%	105	of useful functionality, such as an asynchronous DNS resolver, 100%
…		…
106	useful) and you want to force your users to use the one and only event	111	useful) and you want to force your users to use the one and only event
107	model, you should I<not> use this module.	112	model, you should I<not> use this module.
108		113
109	=head1 DESCRIPTION	114	=head1 DESCRIPTION
110		115
111	L<AnyEvent> provides an identical interface to multiple event loops. This	116	L<AnyEvent> provides a uniform interface to various event loops. This
112	allows module authors to utilise an event loop without forcing module	117	allows module authors to use event loop functionality without forcing
113	users to use the same event loop (as only a single event loop can coexist	118	module users to use a specific event loop implementation (since more
114	peacefully at any one time).	119	than one event loop cannot coexist peacefully).
115		120
116	The interface itself is vaguely similar, but not identical to the L<Event>	121	The interface itself is vaguely similar, but not identical to the L<Event>
117	module.	122	module.
118		123
119	During the first call of any watcher-creation method, the module tries	124	During the first call of any watcher-creation method, the module tries
120	to detect the currently loaded event loop by probing whether one of the	125	to detect the currently loaded event loop by probing whether one of the
121	following modules is already loaded: L<EV>,	126	following modules is already loaded: L<EV>, L<AnyEvent::Loop>,
122	L<Event>, L<Glib>, L<AnyEvent::Impl::Perl>, L<Tk>, L<Event::Lib>, L<Qt>,	127	L<Event>, L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>. The first one
123	L<POE>. The first one found is used. If none are found, the module tries	128	found is used. If none are detected, the module tries to load the first
124	to load these modules (excluding Tk, Event::Lib, Qt and POE as the pure perl	129	four modules in the order given; but note that if L<EV> is not
125	adaptor should always succeed) in the order given. The first one that can	130	available, the pure-perl L<AnyEvent::Loop> should always work, so
126	be successfully loaded will be used. If, after this, still none could be	131	the other two are not normally tried.
127	found, AnyEvent will fall back to a pure-perl event loop, which is not
128	very efficient, but should work everywhere.
129		132
130	Because AnyEvent first checks for modules that are already loaded, loading	133	Because AnyEvent first checks for modules that are already loaded, loading
131	an event model explicitly before first using AnyEvent will likely make	134	an event model explicitly before first using AnyEvent will likely make
132	that model the default. For example:	135	that model the default. For example:
133		136
…		…
135	use AnyEvent;	138	use AnyEvent;
136		139
137	# .. AnyEvent will likely default to Tk	140	# .. AnyEvent will likely default to Tk
138		141
139	The I<likely> means that, if any module loads another event model and	142	The I<likely> means that, if any module loads another event model and
140	starts using it, all bets are off. Maybe you should tell their authors to	143	starts using it, all bets are off - this case should be very rare though,
141	use AnyEvent so their modules work together with others seamlessly...	144	as very few modules hardcode event loops without announcing this very
		145	loudly.
142		146
143	The pure-perl implementation of AnyEvent is called	147	The pure-perl implementation of AnyEvent is called C<AnyEvent::Loop>. Like
144	C<AnyEvent::Impl::Perl>. Like other event modules you can load it	148	other event modules you can load it explicitly and enjoy the high
145	explicitly and enjoy the high availability of that event loop :)	149	availability of that event loop :)
146		150
147	=head1 WATCHERS	151	=head1 WATCHERS
148		152
149	AnyEvent has the central concept of a I<watcher>, which is an object that	153	AnyEvent has the central concept of a I<watcher>, which is an object that
150	stores relevant data for each kind of event you are waiting for, such as	154	stores relevant data for each kind of event you are waiting for, such as
…		…
155	callback when the event occurs (of course, only when the event model	159	callback when the event occurs (of course, only when the event model
156	is in control).	160	is in control).
157		161
158	Note that B<callbacks must not permanently change global variables>	162	Note that B<callbacks must not permanently change global variables>
159	potentially in use by the event loop (such as C<$_> or C<$[>) and that B<<	163	potentially in use by the event loop (such as C<$_> or C<$[>) and that B<<
160	callbacks must not C<die> >>. The former is good programming practise in	164	callbacks must not C<die> >>. The former is good programming practice in
161	Perl and the latter stems from the fact that exception handling differs	165	Perl and the latter stems from the fact that exception handling differs
162	widely between event loops.	166	widely between event loops.
163		167
164	To disable the watcher you have to destroy it (e.g. by setting the	168	To disable a watcher you have to destroy it (e.g. by setting the
165	variable you store it in to C<undef> or otherwise deleting all references	169	variable you store it in to C<undef> or otherwise deleting all references
166	to it).	170	to it).
167		171
168	All watchers are created by calling a method on the C<AnyEvent> class.	172	All watchers are created by calling a method on the C<AnyEvent> class.
169		173
170	Many watchers either are used with "recursion" (repeating timers for	174	Many watchers either are used with "recursion" (repeating timers for
171	example), or need to refer to their watcher object in other ways.	175	example), or need to refer to their watcher object in other ways.
172		176
173	An any way to achieve that is this pattern:	177	One way to achieve that is this pattern:
174		178
175	my $w; $w = AnyEvent->type (arg => value ..., cb => sub {	179	my $w; $w = AnyEvent->type (arg => value ..., cb => sub {
176	# you can use $w here, for example to undef it	180	# you can use $w here, for example to undef it
177	undef $w;	181	undef $w;
178	});	182	});
…		…
180	Note that C<my $w; $w => combination. This is necessary because in Perl,	184	Note that C<my $w; $w => combination. This is necessary because in Perl,
181	my variables are only visible after the statement in which they are	185	my variables are only visible after the statement in which they are
182	declared.	186	declared.
183		187
184	=head2 I/O WATCHERS	188	=head2 I/O WATCHERS
		189
		190	$w = AnyEvent->io (
		191	fh => <filehandle_or_fileno>,
		192	poll => <"r" or "w">,
		193	cb => <callback>,
		194	);
185		195
186	You can create an I/O watcher by calling the C<< AnyEvent->io >> method	196	You can create an I/O watcher by calling the C<< AnyEvent->io >> method
187	with the following mandatory key-value pairs as arguments:	197	with the following mandatory key-value pairs as arguments:
188		198
189	C<fh> is the Perl I<file handle> (or a naked file descriptor) to watch	199	C<fh> is the Perl I<file handle> (or a naked file descriptor) to watch
…		…
204		214
205	The I/O watcher might use the underlying file descriptor or a copy of it.	215	The I/O watcher might use the underlying file descriptor or a copy of it.
206	You must not close a file handle as long as any watcher is active on the	216	You must not close a file handle as long as any watcher is active on the
207	underlying file descriptor.	217	underlying file descriptor.
208		218
209	Some event loops issue spurious readyness notifications, so you should	219	Some event loops issue spurious readiness notifications, so you should
210	always use non-blocking calls when reading/writing from/to your file	220	always use non-blocking calls when reading/writing from/to your file
211	handles.	221	handles.
212		222
213	Example: wait for readability of STDIN, then read a line and disable the	223	Example: wait for readability of STDIN, then read a line and disable the
214	watcher.	224	watcher.
…		…
219	undef $w;	229	undef $w;
220	});	230	});
221		231
222	=head2 TIME WATCHERS	232	=head2 TIME WATCHERS
223		233
		234	$w = AnyEvent->timer (after => <seconds>, cb => <callback>);
		235
		236	$w = AnyEvent->timer (
		237	after => <fractional_seconds>,
		238	interval => <fractional_seconds>,
		239	cb => <callback>,
		240	);
		241
224	You can create a time watcher by calling the C<< AnyEvent->timer >>	242	You can create a time watcher by calling the C<< AnyEvent->timer >>
225	method with the following mandatory arguments:	243	method with the following mandatory arguments:
226		244
227	C<after> specifies after how many seconds (fractional values are	245	C<after> specifies after how many seconds (fractional values are
228	supported) the callback should be invoked. C<cb> is the callback to invoke	246	supported) the callback should be invoked. C<cb> is the callback to invoke
…		…
230		248
231	Although the callback might get passed parameters, their value and	249	Although the callback might get passed parameters, their value and
232	presence is undefined and you cannot rely on them. Portable AnyEvent	250	presence is undefined and you cannot rely on them. Portable AnyEvent
233	callbacks cannot use arguments passed to time watcher callbacks.	251	callbacks cannot use arguments passed to time watcher callbacks.
234		252
235	The callback will normally be invoked once only. If you specify another	253	The callback will normally be invoked only once. If you specify another
236	parameter, C<interval>, as a strictly positive number (> 0), then the	254	parameter, C<interval>, as a strictly positive number (> 0), then the
237	callback will be invoked regularly at that interval (in fractional	255	callback will be invoked regularly at that interval (in fractional
238	seconds) after the first invocation. If C<interval> is specified with a	256	seconds) after the first invocation. If C<interval> is specified with a
239	false value, then it is treated as if it were missing.	257	false value, then it is treated as if it were not specified at all.
240		258
241	The callback will be rescheduled before invoking the callback, but no	259	The callback will be rescheduled before invoking the callback, but no
242	attempt is done to avoid timer drift in most backends, so the interval is	260	attempt is made to avoid timer drift in most backends, so the interval is
243	only approximate.	261	only approximate.
244		262
245	Example: fire an event after 7.7 seconds.	263	Example: fire an event after 7.7 seconds.
246		264
247	my $w = AnyEvent->timer (after => 7.7, cb => sub {	265	my $w = AnyEvent->timer (after => 7.7, cb => sub {
…		…
265		283
266	While most event loops expect timers to specified in a relative way, they	284	While most event loops expect timers to specified in a relative way, they
267	use absolute time internally. This makes a difference when your clock	285	use absolute time internally. This makes a difference when your clock
268	"jumps", for example, when ntp decides to set your clock backwards from	286	"jumps", for example, when ntp decides to set your clock backwards from
269	the wrong date of 2014-01-01 to 2008-01-01, a watcher that is supposed to	287	the wrong date of 2014-01-01 to 2008-01-01, a watcher that is supposed to
270	fire "after" a second might actually take six years to finally fire.	288	fire "after a second" might actually take six years to finally fire.
271		289
272	AnyEvent cannot compensate for this. The only event loop that is conscious	290	AnyEvent cannot compensate for this. The only event loop that is conscious
273	about these issues is L<EV>, which offers both relative (ev_timer, based	291	of these issues is L<EV>, which offers both relative (ev_timer, based
274	on true relative time) and absolute (ev_periodic, based on wallclock time)	292	on true relative time) and absolute (ev_periodic, based on wallclock time)
275	timers.	293	timers.
276		294
277	AnyEvent always prefers relative timers, if available, matching the	295	AnyEvent always prefers relative timers, if available, matching the
278	AnyEvent API.	296	AnyEvent API.
…		…
300	I<In almost all cases (in all cases if you don't care), this is the	318	I<In almost all cases (in all cases if you don't care), this is the
301	function to call when you want to know the current time.>	319	function to call when you want to know the current time.>
302		320
303	This function is also often faster then C<< AnyEvent->time >>, and	321	This function is also often faster then C<< AnyEvent->time >>, and
304	thus the preferred method if you want some timestamp (for example,	322	thus the preferred method if you want some timestamp (for example,
305	L<AnyEvent::Handle> uses this to update it's activity timeouts).	323	L<AnyEvent::Handle> uses this to update its activity timeouts).
306		324
307	The rest of this section is only of relevance if you try to be very exact	325	The rest of this section is only of relevance if you try to be very exact
308	with your timing, you can skip it without bad conscience.	326	with your timing; you can skip it without a bad conscience.
309		327
310	For a practical example of when these times differ, consider L<Event::Lib>	328	For a practical example of when these times differ, consider L<Event::Lib>
311	and L<EV> and the following set-up:	329	and L<EV> and the following set-up:
312		330
313	The event loop is running and has just invoked one of your callback at	331	The event loop is running and has just invoked one of your callbacks at
314	time=500 (assume no other callbacks delay processing). In your callback,	332	time=500 (assume no other callbacks delay processing). In your callback,
315	you wait a second by executing C<sleep 1> (blocking the process for a	333	you wait a second by executing C<sleep 1> (blocking the process for a
316	second) and then (at time=501) you create a relative timer that fires	334	second) and then (at time=501) you create a relative timer that fires
317	after three seconds.	335	after three seconds.
318		336
…		…
338	difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into	356	difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into
339	account.	357	account.
340		358
341	=item AnyEvent->now_update	359	=item AnyEvent->now_update
342		360
343	Some event loops (such as L<EV> or L<AnyEvent::Impl::Perl>) cache	361	Some event loops (such as L<EV> or L<AnyEvent::Loop>) cache the current
344	the current time for each loop iteration (see the discussion of L<<	362	time for each loop iteration (see the discussion of L<< AnyEvent->now >>,
345	AnyEvent->now >>, above).	363	above).
346		364
347	When a callback runs for a long time (or when the process sleeps), then	365	When a callback runs for a long time (or when the process sleeps), then
348	this "current" time will differ substantially from the real time, which	366	this "current" time will differ substantially from the real time, which
349	might affect timers and time-outs.	367	might affect timers and time-outs.
350		368
351	When this is the case, you can call this method, which will update the	369	When this is the case, you can call this method, which will update the
352	event loop's idea of "current time".	370	event loop's idea of "current time".
353		371
		372	A typical example would be a script in a web server (e.g. C<mod_perl>) -
		373	when mod_perl executes the script, then the event loop will have the wrong
		374	idea about the "current time" (being potentially far in the past, when the
		375	script ran the last time). In that case you should arrange a call to C<<
		376	AnyEvent->now_update >> each time the web server process wakes up again
		377	(e.g. at the start of your script, or in a handler).
		378
354	Note that updating the time I<might> cause some events to be handled.	379	Note that updating the time I<might> cause some events to be handled.
355		380
356	=back	381	=back
357		382
358	=head2 SIGNAL WATCHERS	383	=head2 SIGNAL WATCHERS
		384
		385	$w = AnyEvent->signal (signal => <uppercase_signal_name>, cb => <callback>);
359		386
360	You can watch for signals using a signal watcher, C<signal> is the signal	387	You can watch for signals using a signal watcher, C<signal> is the signal
361	I<name> in uppercase and without any C<SIG> prefix, C<cb> is the Perl	388	I<name> in uppercase and without any C<SIG> prefix, C<cb> is the Perl
362	callback to be invoked whenever a signal occurs.	389	callback to be invoked whenever a signal occurs.
363		390
…		…
380		407
381	Example: exit on SIGINT	408	Example: exit on SIGINT
382		409
383	my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });	410	my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });
384		411
		412	=head3 Restart Behaviour
		413
		414	While restart behaviour is up to the event loop implementation, most will
		415	not restart syscalls (that includes L<Async::Interrupt> and AnyEvent's
		416	pure perl implementation).
		417
		418	=head3 Safe/Unsafe Signals
		419
		420	Perl signals can be either "safe" (synchronous to opcode handling)
		421	or "unsafe" (asynchronous) - the former might delay signal delivery
		422	indefinitely, the latter might corrupt your memory.
		423
		424	AnyEvent signal handlers are, in addition, synchronous to the event loop,
		425	i.e. they will not interrupt your running perl program but will only be
		426	called as part of the normal event handling (just like timer, I/O etc.
		427	callbacks, too).
		428
385	=head3 Signal Races, Delays and Workarounds	429	=head3 Signal Races, Delays and Workarounds
386		430
387	Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support attaching	431	Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support
388	callbacks to signals in a generic way, which is a pity, as you cannot do	432	attaching callbacks to signals in a generic way, which is a pity,
389	race-free signal handling in perl. AnyEvent will try to do it's best, but	433	as you cannot do race-free signal handling in perl, requiring
		434	C libraries for this. AnyEvent will try to do its best, which
390	in some cases, signals will be delayed. The maximum time a signal might	435	means in some cases, signals will be delayed. The maximum time
391	be delayed is specified in C<$AnyEvent::MAX_SIGNAL_LATENCY> (default: 10	436	a signal might be delayed is 10 seconds by default, but can
392	seconds). This variable can be changed only before the first signal	437	be overriden via C<$ENV{PERL_ANYEVENT_MAX_SIGNAL_LATENCY}> or
393	watcher is created, and should be left alone otherwise. Higher values	438	C<$AnyEvent::MAX_SIGNAL_LATENCY> - see the L<ENVIRONMENT VARIABLES>
394	will cause fewer spurious wake-ups, which is better for power and CPU	439	section for details.
		440
395	saving. All these problems can be avoided by installing the optional	441	All these problems can be avoided by installing the optional
396	L<Async::Interrupt> module. This will not work with inherently broken	442	L<Async::Interrupt> module, which works with most event loops. It will not
397	event loops such as L<Event> or L<Event::Lib> (and not with L<POE>	443	work with inherently broken event loops such as L<Event> or L<Event::Lib>
398	currently, as POE does it's own workaround with one-second latency). With	444	(and not with L<POE> currently). For those, you just have to suffer the
399	those, you just have to suffer the delays.	445	delays.
400		446
401	=head2 CHILD PROCESS WATCHERS	447	=head2 CHILD PROCESS WATCHERS
402		448
		449	$w = AnyEvent->child (pid => <process id>, cb => <callback>);
		450
403	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.
404		452
405	The child process is specified by the C<pid> argument (one some backends,	453	The child process is specified by the C<pid> argument (on some backends,
406	using C<0> watches for any child process exit, on others this will	454	using C<0> watches for any child process exit, on others this will
407	croak). The watcher will be triggered only when the child process has	455	croak). The watcher will be triggered only when the child process has
408	finished and an exit status is available, not on any trace events	456	finished and an exit status is available, not on any trace events
409	(stopped/continued).	457	(stopped/continued).
410		458
…		…
432	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
433	watcher before you C<fork> the child (alternatively, you can call	481	watcher before you C<fork> the child (alternatively, you can call
434	C<AnyEvent::detect>).	482	C<AnyEvent::detect>).
435		483
436	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
437	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
438	mentioned in the description of signal watchers apply.	486	problems mentioned in the description of signal watchers apply.
439		487
440	Example: fork a process and wait for it	488	Example: fork a process and wait for it
441		489
442	my $done = AnyEvent->condvar;	490	my $done = AnyEvent->condvar;
443		491
…		…
455	# do something else, then wait for process exit	503	# do something else, then wait for process exit
456	$done->recv;	504	$done->recv;
457		505
458	=head2 IDLE WATCHERS	506	=head2 IDLE WATCHERS
459		507
460	Sometimes there is a need to do something, but it is not so important	508	$w = AnyEvent->idle (cb => <callback>);
461	to do it instantly, but only when there is nothing better to do. This
462	"nothing better to do" is usually defined to be "no other events need
463	attention by the event loop".
464		509
465	Idle watchers ideally get invoked when the event loop has nothing	510	This will repeatedly invoke the callback after the process becomes idle,
466	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.
467	events. Instead of blocking, the idle watcher is invoked.
468		512
469	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
470	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
471	will simply call the callback "from time to time".	524	will simply call the callback "from time to time".
472		525
473	Example: read lines from STDIN, but only process them when the	526	Example: read lines from STDIN, but only process them when the
474	program is otherwise idle:	527	program is otherwise idle:
…		…
490	});	543	});
491	});	544	});
492		545
493	=head2 CONDITION VARIABLES	546	=head2 CONDITION VARIABLES
494		547
		548	$cv = AnyEvent->condvar;
		549
		550	$cv->send (<list>);
		551	my @res = $cv->recv;
		552
495	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
496	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
497	will actively watch for new events and call your callbacks.	555	will actively watch for new events and call your callbacks.
498		556
499	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
500	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).
501		559
502	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
503	because they represent a condition that must become true.	561	they represent a condition that must become true.
504		562
505	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.
506		564
507	Condition variables can be created by calling the C<< AnyEvent->condvar	565	Condition variables can be created by calling the C<< AnyEvent->condvar
508	>> method, usually without arguments. The only argument pair allowed is	566	>> method, usually without arguments. The only argument pair allowed is
…		…
513	After creation, the condition variable is "false" until it becomes "true"	571	After creation, the condition variable is "false" until it becomes "true"
514	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
515	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<<
516	->send >> method).	574	->send >> method).
517		575
518	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
519	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:
520	in time where multiple outstanding events have been processed. And yet	578
521	another way to call them is transactions - each condition variable can be	579	=over 4
522	used to represent a transaction, which finishes at some point and delivers	580
523	a result. And yet some people know them as "futures" - a promise to	581	=item * Condition variables are like callbacks - you can call them (and pass them instead
524	compute/deliver something that you can wait for.	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
525		599
526	Condition variables are very useful to signal that something has finished,	600	Condition variables are very useful to signal that something has finished,
527	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,
528	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
529	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
…		…
542		616
543	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
544	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
545	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
546	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
547	it's C<new> method in your own C<new> method.	621	its C<new> method in your own C<new> method.
548		622
549	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
550	eventually calls C<< -> send >>, and the "consumer side", which waits	624	eventually calls C<< -> send >>, and the "consumer side", which waits
551	for the send to occur.	625	for the send to occur.
552		626
553	Example: wait for a timer.	627	Example: wait for a timer.
554		628
555	# wait till the result is ready	629	# condition: "wait till the timer is fired"
556	my $result_ready = AnyEvent->condvar;	630	my $timer_fired = AnyEvent->condvar;
557		631
558	# do something such as adding a timer	632	# create the timer - we could wait for, say
559	# or socket watcher the calls $result_ready->send	633	# a handle becomign ready, or even an
560	# when the "result" is ready.	634	# AnyEvent::HTTP request to finish, but
561	# in this case, we simply use a timer:	635	# in this case, we simply use a timer:
562	my $w = AnyEvent->timer (	636	my $w = AnyEvent->timer (
563	after => 1,	637	after => 1,
564	cb => sub { $result_ready->send },	638	cb => sub { $timer_fired->send },
565	);	639	);
566		640
567	# this "blocks" (while handling events) till the callback	641	# this "blocks" (while handling events) till the callback
568	# calls -<send	642	# calls ->send
569	$result_ready->recv;	643	$timer_fired->recv;
570		644
571	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
572	variables are also callable directly.	646	variables are also callable directly.
573		647
574	my $done = AnyEvent->condvar;	648	my $done = AnyEvent->condvar;
…		…
617	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
618	C<send>.	692	C<send>.
619		693
620	=item $cv->croak ($error)	694	=item $cv->croak ($error)
621		695
622	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
623	C<Carp::croak> with the given error message/object/scalar.	697	C<Carp::croak> with the given error message/object/scalar.
624		698
625	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
626	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
627	delays the error detetcion, but has the overwhelmign advantage that it	701	delays the error detection, but has the overwhelming advantage that it
628	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
629	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
630	the problem.	704	the problem.
631		705
632	=item $cv->begin ([group callback])	706	=item $cv->begin ([group callback])
633		707
634	=item $cv->end	708	=item $cv->end
…		…
637	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
638	to use a condition variable for the whole process.	712	to use a condition variable for the whole process.
639		713
640	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
641	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
642	>>, 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
643	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
644	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.
645		720
646	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
647	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
648	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).
649		724
…		…
671	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
672	sending.	747	sending.
673		748
674	The ping example mentioned above is slightly more complicated, as the	749	The ping example mentioned above is slightly more complicated, as the
675	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
676	begung can potentially be zero:	751	begun can potentially be zero:
677		752
678	my $cv = AnyEvent->condvar;	753	my $cv = AnyEvent->condvar;
679		754
680	my %result;	755	my %result;
681	$cv->begin (sub { $cv->send (\%result) });	756	$cv->begin (sub { shift->send (\%result) });
682		757
683	for my $host (@list_of_hosts) {	758	for my $host (@list_of_hosts) {
684	$cv->begin;	759	$cv->begin;
685	ping_host_then_call_callback $host, sub {	760	ping_host_then_call_callback $host, sub {
686	$result{$host} = ...;	761	$result{$host} = ...;
…		…
702	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
703	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
704	doesn't execute once).	779	doesn't execute once).
705		780
706	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
707	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
708	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
709	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,
710	call C<end>.	785	call C<end>.
711		786
712	=back	787	=back
…		…
719	=over 4	794	=over 4
720		795
721	=item $cv->recv	796	=item $cv->recv
722		797
723	Wait (blocking if necessary) until the C<< ->send >> or C<< ->croak	798	Wait (blocking if necessary) until the C<< ->send >> or C<< ->croak
724	>> methods have been called on c<$cv>, while servicing other watchers	799	>> methods have been called on C<$cv>, while servicing other watchers
725	normally.	800	normally.
726		801
727	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
728	will return immediately.	803	will return immediately.
729		804
…		…
746	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
747	condition variables with some kind of request results and supporting	822	condition variables with some kind of request results and supporting
748	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,
749	while still supporting blocking waits if the caller so desires).	824	while still supporting blocking waits if the caller so desires).
750		825
751	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
752	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
753	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
754	waits otherwise.	829	waits otherwise.
755		830
756	=item $bool = $cv->ready	831	=item $bool = $cv->ready
…		…
762		837
763	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
764	replaces it before doing so.	839	replaces it before doing so.
765		840
766	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
767	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
768	variable itself. Calling C<recv> inside the callback or at any later time	843	condition variable itself. If the condition is already true, the
769	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.
770		846
771	=back	847	=back
772		848
773	=head1 SUPPORTED EVENT LOOPS/BACKENDS	849	=head1 SUPPORTED EVENT LOOPS/BACKENDS
774		850
…		…
777	=over 4	853	=over 4
778		854
779	=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.
780		856
781	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
782	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
783	that, will fall back to its own pure-perl implementation, which is	859	pure-perl implementation, which is available everywhere as it comes with
784	available everywhere as it comes with AnyEvent itself.	860	AnyEvent itself.
785		861
786	AnyEvent::Impl::EV based on EV (interface to libev, best choice).	862	AnyEvent::Impl::EV based on EV (interface to libev, best choice).
787	AnyEvent::Impl::Event based on Event, very stable, few glitches.
788	AnyEvent::Impl::Perl pure-perl implementation, fast and portable.	863	AnyEvent::Impl::Perl pure-perl AnyEvent::Loop, fast and portable.
789		864
790	=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.
791		866
792	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
793	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
794	them. This means that AnyEvent will automatically pick the right backend	869	them. This means that AnyEvent will automatically pick the right backend
795	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
796	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.
797		872
		873	AnyEvent::Impl::Event based on Event, very stable, few glitches.
798	AnyEvent::Impl::Glib based on Glib, slow but very stable.	874	AnyEvent::Impl::Glib based on Glib, slow but very stable.
799	AnyEvent::Impl::Tk based on Tk, very broken.	875	AnyEvent::Impl::Tk based on Tk, very broken.
800	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.	876	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
801	AnyEvent::Impl::POE based on POE, very slow, some limitations.	877	AnyEvent::Impl::POE based on POE, very slow, some limitations.
802	AnyEvent::Impl::Irssi used when running within irssi.	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).
803		882
804	=item Backends with special needs.	883	=item Backends with special needs.
805		884
806	Qt requires the Qt::Application to be instantiated first, but will	885	Qt requires the Qt::Application to be instantiated first, but will
807	otherwise be picked up automatically. As long as the main program	886	otherwise be picked up automatically. As long as the main program
808	instantiates the application before any AnyEvent watchers are created,	887	instantiates the application before any AnyEvent watchers are created,
809	everything should just work.	888	everything should just work.
810		889
811	AnyEvent::Impl::Qt based on Qt.	890	AnyEvent::Impl::Qt based on Qt.
812		891
813	Support for IO::Async can only be partial, as it is too broken and
814	architecturally limited to even support the AnyEvent API. It also
815	is the only event loop that needs the loop to be set explicitly, so
816	it can only be used by a main program knowing about AnyEvent. See
817	L<AnyEvent::Impl::Async> for the gory details.
818
819	AnyEvent::Impl::IOAsync based on IO::Async, cannot be autoprobed.
820
821	=item Event loops that are indirectly supported via other backends.	892	=item Event loops that are indirectly supported via other backends.
822		893
823	Some event loops can be supported via other modules:	894	Some event loops can be supported via other modules:
824		895
825	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>.
…		…
850	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
851	backend has been autodetected.	922	backend has been autodetected.
852		923
853	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
854	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
855	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
856	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
857	will be C<urxvt::anyevent>).	928	will be C<urxvt::anyevent>).
858		929
859	=item AnyEvent::detect	930	=item AnyEvent::detect
860		931
861	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model	932	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model
862	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
863	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
864	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).
865		940
866	If you need to do some initialisation before AnyEvent watchers are	941	If you need to do some initialisation before AnyEvent watchers are
867	created, use C<post_detect>.	942	created, use C<post_detect>.
868		943
869	=item $guard = AnyEvent::post_detect { BLOCK }	944	=item $guard = AnyEvent::post_detect { BLOCK }
870		945
871	Arranges for the code block to be executed as soon as the event model is	946	Arranges for the code block to be executed as soon as the event model is
872	autodetected (or immediately if this has already happened).	947	autodetected (or immediately if that has already happened).
873		948
874	The block will be executed I<after> the actual backend has been detected	949	The block will be executed I<after> the actual backend has been detected
875	(C<$AnyEvent::MODEL> is set), but I<before> any watchers have been	950	(C<$AnyEvent::MODEL> is set), but I<before> any watchers have been
876	created, so it is possible to e.g. patch C<@AnyEvent::ISA> or do	951	created, so it is possible to e.g. patch C<@AnyEvent::ISA> or do
877	other initialisations - see the sources of L<AnyEvent::Strict> or	952	other initialisations - see the sources of L<AnyEvent::Strict> or
…		…
886	that automatically removes the callback again when it is destroyed (or	961	that automatically removes the callback again when it is destroyed (or
887	C<undef> when the hook was immediately executed). See L<AnyEvent::AIO> for	962	C<undef> when the hook was immediately executed). See L<AnyEvent::AIO> for
888	a case where this is useful.	963	a case where this is useful.
889		964
890	Example: Create a watcher for the IO::AIO module and store it in	965	Example: Create a watcher for the IO::AIO module and store it in
891	C<$WATCHER>. Only do so after the event loop is initialised, though.	966	C<$WATCHER>, but do so only do so after the event loop is initialised.
892		967
893	our WATCHER;	968	our WATCHER;
894		969
895	my $guard = AnyEvent::post_detect {	970	my $guard = AnyEvent::post_detect {
896	$WATCHER = AnyEvent->io (fh => IO::AIO::poll_fileno, poll => 'r', cb => \&IO::AIO::poll_cb);	971	$WATCHER = AnyEvent->io (fh => IO::AIO::poll_fileno, poll => 'r', cb => \&IO::AIO::poll_cb);
…		…
904	$WATCHER ||= $guard;	979	$WATCHER ||= $guard;
905		980
906	=item @AnyEvent::post_detect	981	=item @AnyEvent::post_detect
907		982
908	If there are any code references in this array (you can C<push> to it	983	If there are any code references in this array (you can C<push> to it
909	before or after loading AnyEvent), then they will called directly after	984	before or after loading AnyEvent), then they will be called directly
910	the event loop has been chosen.	985	after the event loop has been chosen.
911		986
912	You should check C<$AnyEvent::MODEL> before adding to this array, though:	987	You should check C<$AnyEvent::MODEL> before adding to this array, though:
913	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
914	array will be ignored.	989	array will be ignored.
915		990
916	Best use C<AnyEvent::post_detect { BLOCK }> when your application allows	991	Best use C<AnyEvent::post_detect { BLOCK }> when your application allows
917	it,as it takes care of these details.	992	it, as it takes care of these details.
918		993
919	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
920	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
921	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
922	into AnyEvent passively, without loading it.	997	into AnyEvent passively, without loading it.
923		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
924	=back	1070	=back
925		1071
926	=head1 WHAT TO DO IN A MODULE	1072	=head1 WHAT TO DO IN A MODULE
927		1073
928	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
…		…
938	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
939	events is to stay interactive.	1085	events is to stay interactive.
940		1086
941	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
942	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
943	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 >>
944	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).
945		1091
946	=head1 WHAT TO DO IN THE MAIN PROGRAM	1092	=head1 WHAT TO DO IN THE MAIN PROGRAM
947		1093
948	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
949	dictate which event model to use.	1095	dictate which event model to use.
950		1096
951	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
952	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
953	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.
954		1102
955	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
956	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
957	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
958	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
959	modules might create watchers when they are loaded, and AnyEvent will	1107	modules might create watchers when they are loaded, and AnyEvent will
960	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
961	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.
962		1110
963	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
964	C<AnyEvent::Impl::Perl> module, which gives you similar behaviour	1112	C<AnyEvent::Loop> module, which gives you similar behaviour
965	everywhere, but letting AnyEvent chose the model is generally better.	1113	everywhere, but letting AnyEvent chose the model is generally better.
966		1114
967	=head2 MAINLOOP EMULATION	1115	=head2 MAINLOOP EMULATION
968		1116
969	Sometimes (often for short test scripts, or even standalone programs who	1117	Sometimes (often for short test scripts, or even standalone programs who
…		…
982		1130
983		1131
984	=head1 OTHER MODULES	1132	=head1 OTHER MODULES
985		1133
986	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
987	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
988	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
989	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 :)
990		1141
991	=over 4	1142	=over 4
992		1143
993	=item L<AnyEvent::Util>	1144	=item L<AnyEvent::Util>
994		1145
995	Contains various utility functions that replace often-used but blocking	1146	Contains various utility functions that replace often-used blocking
996	functions such as C<inet_aton> by event-/callback-based versions.	1147	functions such as C<inet_aton> with event/callback-based versions.
997		1148
998	=item L<AnyEvent::Socket>	1149	=item L<AnyEvent::Socket>
999		1150
1000	Provides various utility functions for (internet protocol) sockets,	1151	Provides various utility functions for (internet protocol) sockets,
1001	addresses and name resolution. Also functions to create non-blocking tcp	1152	addresses and name resolution. Also functions to create non-blocking tcp
…		…
1003		1154
1004	=item L<AnyEvent::Handle>	1155	=item L<AnyEvent::Handle>
1005		1156
1006	Provide read and write buffers, manages watchers for reads and writes,	1157	Provide read and write buffers, manages watchers for reads and writes,
1007	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
1008	non-blocking SSL/TLS (via L<AnyEvent::TLS>.	1159	non-blocking SSL/TLS (via L<AnyEvent::TLS>).
1009		1160
1010	=item L<AnyEvent::DNS>	1161	=item L<AnyEvent::DNS>
1011		1162
1012	Provides rich asynchronous DNS resolver capabilities.	1163	Provides rich asynchronous DNS resolver capabilities.
1013		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
1014	=item L<AnyEvent::HTTP>	1171	=item L<AnyEvent::AIO>
1015		1172
1016	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
1017	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.
1018		1195
1019	=item L<AnyEvent::HTTPD>	1196	=item L<AnyEvent::HTTPD>
1020		1197
1021	Provides a simple web application server framework.	1198	A simple embedded webserver.
1022		1199
1023	=item L<AnyEvent::FastPing>	1200	=item L<AnyEvent::FastPing>
1024		1201
1025	The fastest ping in the west.	1202	The fastest ping in the west.
1026		1203
1027	=item L<AnyEvent::DBI>
1028
1029	Executes L<DBI> requests asynchronously in a proxy process.
1030
1031	=item L<AnyEvent::AIO>
1032
1033	Truly asynchronous I/O, should be in the toolbox of every event
1034	programmer. AnyEvent::AIO transparently fuses L<IO::AIO> and AnyEvent
1035	together.
1036
1037	=item L<AnyEvent::BDB>
1038
1039	Truly asynchronous Berkeley DB access. AnyEvent::BDB transparently fuses
1040	L<BDB> and AnyEvent together.
1041
1042	=item L<AnyEvent::GPSD>
1043
1044	A non-blocking interface to gpsd, a daemon delivering GPS information.
1045
1046	=item L<AnyEvent::IRC>
1047
1048	AnyEvent based IRC client module family (replacing the older Net::IRC3).
1049
1050	=item L<AnyEvent::XMPP>
1051
1052	AnyEvent based XMPP (Jabber protocol) module family (replacing the older
1053	Net::XMPP2>.
1054
1055	=item L<AnyEvent::IGS>
1056
1057	A non-blocking interface to the Internet Go Server protocol (used by
1058	L<App::IGS>).
1059
1060	=item L<Net::FCP>
1061
1062	AnyEvent-based implementation of the Freenet Client Protocol, birthplace
1063	of AnyEvent.
1064
1065	=item L<Event::ExecFlow>
1066
1067	High level API for event-based execution flow control.
1068
1069	=item L<Coro>	1204	=item L<Coro>
1070		1205
1071	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	};
1072		1219
1073	=back	1220	=back
1074		1221
1075	=cut	1222	=cut
1076		1223
1077	package AnyEvent;	1224	package AnyEvent;
1078		1225
1079	# basically a tuned-down version of common::sense	1226	# basically a tuned-down version of common::sense
1080	sub common_sense {	1227	sub common_sense {
1081	# no warnings	1228	# from common:.sense 3.5
1082	${^WARNING_BITS} ^= ${^WARNING_BITS};	1229	local $^W;
1083	# use strict vars subs	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)
1084	$^H |= 0x00000600;	1232	$^H |= 0x00000600;
1085	}	1233	}
1086		1234
1087	BEGIN { AnyEvent::common_sense }	1235	BEGIN { AnyEvent::common_sense }
1088		1236
1089	use Carp ();	1237	use Carp ();
1090		1238
1091	our $VERSION = 4.88;	1239	our $VERSION = '7.03';
1092	our $MODEL;	1240	our $MODEL;
1093
1094	our $AUTOLOAD;
1095	our @ISA;	1241	our @ISA;
1096
1097	our @REGISTRY;	1242	our @REGISTRY;
1098
1099	our $WIN32;
1100
1101	our $VERBOSE;	1243	our $VERBOSE;
		1244	our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred
		1245	our $MAX_SIGNAL_LATENCY = $ENV{PERL_ANYEVENT_MAX_SIGNAL_LATENCY} || 10; # executes after the BEGIN block below (tainting!)
1102		1246
1103	BEGIN {	1247	BEGIN {
1104	eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }";	1248	require "AnyEvent/constants.pl";
		1249
1105	eval "sub TAINT(){ " . (${^TAINT}*1) . " }";	1250	eval "sub TAINT (){" . (${^TAINT}*1) . "}";
1106		1251
1107	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}	1252	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}
1108	if ${^TAINT};	1253	if ${^TAINT};
1109		1254
1110	$VERBOSE = $ENV{PERL_ANYEVENT_VERBOSE}*1;	1255	$ENV{"PERL_ANYEVENT_$_"} = $ENV{"AE_$_"}
		1256	for grep s/^AE_// && !exists $ENV{"PERL_ANYEVENT_$_"}, keys %ENV;
1111		1257
1112	}	1258	@ENV{grep /^PERL_ANYEVENT_/, keys %ENV} = ()
		1259	if ${^TAINT};
1113		1260
1114	our $MAX_SIGNAL_LATENCY = 10;	1261	# $ENV{PERL_ANYEVENT_xxx} now valid
1115		1262
1116	our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred	1263	$VERBOSE = length $ENV{PERL_ANYEVENT_VERBOSE} ? $ENV{PERL_ANYEVENT_VERBOSE}*1 : 4;
1117		1264
1118	{
1119	my $idx;	1265	my $idx;
1120	$PROTOCOL{$_} = ++$idx	1266	$PROTOCOL{$_} = ++$idx
1121	for reverse split /\s*,\s*/,	1267	for reverse split /\s*,\s*/,
1122	$ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";	1268	$ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";
1123	}	1269	}
1124		1270
		1271	our @post_detect;
		1272
		1273	sub post_detect(&) {
		1274	my ($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
1125	my @models = (	1348	our @models = (
1126	[EV:: => AnyEvent::Impl::EV:: , 1],	1349	[EV:: => AnyEvent::Impl::EV::],
1127	[Event:: => AnyEvent::Impl::Event::, 1],	1350	[AnyEvent::Loop:: => AnyEvent::Impl::Perl::],
1128	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl:: , 1],
1129	# everything below here will not (normally) be autoprobed	1351	# everything below here will not (normally) be autoprobed
1130	# as the pureperl backend should work everywhere	1352	# as the pure perl backend should work everywhere
1131	# 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
1132	[Glib:: => AnyEvent::Impl::Glib:: , 1], # 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
1133	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy	1358	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
1134	[Irssi:: => AnyEvent::Impl::Irssi::], # Irssi has a bogus "Event" package
1135	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles	1359	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
1136	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program	1360	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program
1137	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza	1361	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
1138	[Wx:: => AnyEvent::Impl::POE::],	1362	[Wx:: => AnyEvent::Impl::POE::],
1139	[Prima:: => AnyEvent::Impl::POE::],	1363	[Prima:: => AnyEvent::Impl::POE::],
1140	# IO::Async is just too broken - we would need workarounds for its	1364	[IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # a bitch to autodetect
1141	# byzantine signal and broken child handling, among others.	1365	[Cocoa::EventLoop:: => AnyEvent::Impl::Cocoa::],
1142	# IO::Async is rather hard to detect, as it doesn't have any	1366	[FLTK:: => AnyEvent::Impl::FLTK::],
1143	# obvious default class.
1144	# [0, IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program
1145	# [0, IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program
1146	# [0, IO::Async::Notifier:: => AnyEvent::Impl::IOAsync::], # requires special main program
1147	);	1367	);
1148		1368
1149	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, $reset_ae] : undef;
		1386
		1387	_isa_set;
		1388	}
		1389
		1390	# all autoloaded methods reserve the complete glob, not just the method slot.
		1391	# due to bugs in perls method cache implementation.
1150	qw(io timer time now now_update signal child idle condvar one_event DESTROY);	1392	our @methods = qw(io timer time now now_update signal child idle condvar);
1151		1393
1152	our @post_detect;
1153
1154	sub post_detect(&) {	1394	sub detect() {
1155	my ($cb) = @_;	1395	return $MODEL if $MODEL; # some programs keep references to detect
1156		1396
1157	if ($MODEL) {	1397	# IO::Async::Loop::AnyEvent is extremely evil, refuse to work with it
1158	$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 => "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"};
1159		1404
1160	undef	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;
1161	} else {	1424	} else {
1162	push @post_detect, $cb;	1425	AnyEvent::log 4 => "Unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@";
1163		1426	}
1164	defined wantarray
1165	? bless \$cb, "AnyEvent::Util::postdetect"
1166	: ()
1167	}	1427	}
1168	}
1169		1428
1170	sub AnyEvent::Util::postdetect::DESTROY {	1429	# check for already loaded models
1171	@post_detect = grep $_ != ${$_[0]}, @post_detect;
1172	}
1173
1174	sub detect() {
1175	unless ($MODEL) {	1430	unless ($MODEL) {
1176	local $SIG{__DIE__};	1431	for (@REGISTRY, @models) {
1177		1432	my ($package, $model) = @$_;
1178	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {	1433	if (${"$package\::VERSION"} > 0) {
1179	my $model = "AnyEvent::Impl::$1";
1180	if (eval "require $model") {	1434	if (eval "require $model") {
		1435	AnyEvent::log 7 => "Autodetected model '$model', using it.";
1181	$MODEL = $model;	1436	$MODEL = $model;
1182	warn "AnyEvent: loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.\n" if $VERBOSE >= 2;	1437	last;
1183	} else {	1438	} else {
1184	warn "AnyEvent: unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@" if $VERBOSE;	1439	AnyEvent::log 8 => "Detected event loop $package, but cannot load '$model', skipping: $@";
		1440	}
1185	}	1441	}
1186	}	1442	}
1187		1443
1188	# check for already loaded models
1189	unless ($MODEL) {	1444	unless ($MODEL) {
		1445	# try to autoload a model
1190	for (@REGISTRY, @models) {	1446	for (@REGISTRY, @models) {
1191	my ($package, $model) = @$_;	1447	my ($package, $model) = @$_;
		1448	if (
		1449	eval "require $package"
1192	if (${"$package\::VERSION"} > 0) {	1450	and ${"$package\::VERSION"} > 0
1193	if (eval "require $model") {	1451	and eval "require $model"
		1452	) {
		1453	AnyEvent::log 7 => "Autoloaded model '$model', using it.";
1194	$MODEL = $model;	1454	$MODEL = $model;
1195	warn "AnyEvent: autodetected model '$model', using it.\n" if $VERBOSE >= 2;
1196	last;	1455	last;
1197	}
1198	}	1456	}
1199	}	1457	}
1200		1458
1201	unless ($MODEL) {
1202	# try to autoload a model
1203	for (@REGISTRY, @models) {
1204	my ($package, $model, $autoload) = @$_;
1205	if (
1206	$autoload
1207	and eval "require $package"
1208	and ${"$package\::VERSION"} > 0
1209	and eval "require $model"
1210	) {
1211	$MODEL = $model;
1212	warn "AnyEvent: autoloaded model '$model', using it.\n" if $VERBOSE >= 2;
1213	last;
1214	}
1215	}
1216
1217	$MODEL	1459	$MODEL
1218	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.\n";	1460	or AnyEvent::log fatal => "Backend autodetection failed - did you properly install AnyEvent?";
1219	}
1220	}	1461	}
1221
1222	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
1223
1224	unshift @ISA, $MODEL;
1225
1226	require AnyEvent::Strict if $ENV{PERL_ANYEVENT_STRICT};
1227
1228	(shift @post_detect)->() while @post_detect;
1229	}	1462	}
1230		1463
		1464	# free memory only needed for probing
		1465	undef @models;
		1466	undef @REGISTRY;
		1467
		1468	push @{"$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
1231	$MODEL	1513	$MODEL
1232	}	1514	}
1233		1515
1234	sub AUTOLOAD {	1516	for my $name (@methods) {
1235	(my $func = $AUTOLOAD) =~ s/.*://;	1517	*$name = sub {
1236		1518	detect;
1237	$method{$func}	1519	# we use goto because
1238	or Carp::croak "$func: not a valid method for AnyEvent objects";	1520	# a) it makes the thunk more transparent
1239		1521	# b) it allows us to delete the thunk later
1240	detect unless $MODEL;	1522	goto &{ UNIVERSAL::can AnyEvent => "SUPER::$name" }
1241		1523	};
1242	my $class = shift;
1243	$class->$func (@_);
1244	}	1524	}
1245		1525
1246	# 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
1247	# to support binding more than one watcher per filehandle (they usually	1527	# to support binding more than one watcher per filehandle (they usually
1248	# 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).
…		…
1258	# 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
1259		1539
1260	($fh2, $rw)	1540	($fh2, $rw)
1261	}	1541	}
1262		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
1263	package AnyEvent::Base;	1606	package AnyEvent::Base;
1264		1607
1265	# default implementations for many methods	1608	# default implementations for many methods
1266		1609
1267	sub _time {	1610	sub time {
		1611	eval q{ # poor man's autoloading {}
1268	# probe for availability of Time::HiRes	1612	# probe for availability of Time::HiRes
1269	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {	1613	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {
1270	warn "AnyEvent: using Time::HiRes for sub-second timing accuracy.\n" if $VERBOSE >= 8;	1614	*time = sub { Time::HiRes::time () };
1271	*_time = \&Time::HiRes::time;	1615	*AE::time = \& Time::HiRes::time ;
		1616	*now = \&time;
		1617	AnyEvent::log 8 => "using Time::HiRes for sub-second timing accuracy.";
1272	# if (eval "use POSIX (); (POSIX::times())...	1618	# if (eval "use POSIX (); (POSIX::times())...
1273	} else {	1619	} else {
1274	warn "AnyEvent: using built-in time(), WARNING, no sub-second resolution!\n" if $VERBOSE;	1620	*time = sub { CORE::time };
1275	*_time = sub { time }; # epic fail	1621	*AE::time = sub (){ CORE::time };
		1622	*now = \&time;
		1623	AnyEvent::log 3 => "Using built-in time(), no sub-second resolution!";
		1624	}
1276	}	1625	};
		1626	die if $@;
1277		1627
1278	&_time	1628	&time
1279	}	1629	}
1280		1630
1281	sub time { _time }	1631	*now = \&time;
1282	sub now { _time }
1283	sub now_update { }	1632	sub now_update { }
1284		1633
		1634	sub _poll {
		1635	Carp::croak "$AnyEvent::MODEL does not support blocking waits. Caught";
		1636	}
		1637
1285	# default implementation for ->condvar	1638	# default implementation for ->condvar
		1639	# in fact, the default should not be overwritten
1286		1640
1287	sub condvar {	1641	sub condvar {
		1642	eval q{ # poor man's autoloading {}
		1643	*condvar = sub {
1288	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
1289	}	1654	}
1290		1655
1291	# default implementation for ->signal	1656	# default implementation for ->signal
1292		1657
1293	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
1294	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);	1668	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);
1295	our (%SIG_ASY, %SIG_ASY_W);	1669	our (%SIG_ASY, %SIG_ASY_W);
1296	our ($SIG_COUNT, $SIG_TW);	1670	our ($SIG_COUNT, $SIG_TW);
1297		1671
1298	sub _signal_exec {
1299	$HAVE_ASYNC_INTERRUPT
1300	? $SIGPIPE_R->drain
1301	: sysread $SIGPIPE_R, my $dummy, 9;
1302
1303	while (%SIG_EV) {
1304	for (keys %SIG_EV) {
1305	delete $SIG_EV{$_};
1306	$_->() for values %{ $SIG_CB{$_} || {} };
1307	}
1308	}
1309	}
1310
1311	# install a dumym wakeupw atcher to reduce signal catching latency	1672	# install a dummy wakeup watcher to reduce signal catching latency
		1673	# used by Impls
1312	sub _sig_add() {	1674	sub _sig_add() {
1313	unless ($SIG_COUNT++) {	1675	unless ($SIG_COUNT++) {
1314	# try to align timer on a full-second boundary, if possible	1676	# try to align timer on a full-second boundary, if possible
1315	my $NOW = AnyEvent->now;	1677	my $NOW = AE::now;
1316		1678
1317	$SIG_TW = AnyEvent->timer (	1679	$SIG_TW = AE::timer
1318	after => $MAX_SIGNAL_LATENCY - ($NOW - int $NOW),	1680	$MAX_SIGNAL_LATENCY - ($NOW - int $NOW),
1319	interval => $MAX_SIGNAL_LATENCY,	1681	$MAX_SIGNAL_LATENCY,
1320	cb => sub { }, # just for the PERL_ASYNC_CHECK	1682	sub { } # just for the PERL_ASYNC_CHECK
1321	);	1683	;
1322	}	1684	}
1323	}	1685	}
1324		1686
1325	sub _sig_del {	1687	sub _sig_del {
1326	undef $SIG_TW	1688	undef $SIG_TW
1327	unless --$SIG_COUNT;	1689	unless --$SIG_COUNT;
1328	}	1690	}
1329		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
1330	sub _signal {	1723	sub signal {
1331	my (undef, %arg) = @_;	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.";
1332		1728
1333	my $signal = uc $arg{signal}	1729	$SIGPIPE_R = new Async::Interrupt::EventPipe;
1334	or Carp::croak "required option 'signal' is missing";	1730	$SIG_IO = AE::io $SIGPIPE_R->fileno, 0, \&_signal_exec;
1335		1731
1336	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};	1732	} else {
		1733	AnyEvent::log 8 => "Using emulated perl signal handling with latency timer.";
1337		1734
1338	if ($HAVE_ASYNC_INTERRUPT) {	1735	if (AnyEvent::WIN32) {
1339	# async::interrupt	1736	require AnyEvent::Util;
1340		1737
1341	$SIG_ASY{$signal} ||= do {	1738	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
1342	my $asy = new Async::Interrupt	1739	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R, 1) if $SIGPIPE_R;
1343	cb => sub { undef $SIG_EV{$signal} },	1740	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W, 1) if $SIGPIPE_W; # just in case
1344	signal => $signal,	1741	} else {
1345	pipe => [$SIGPIPE_R->filenos],	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;
1346	;	1749	}
1347	$asy->pipe_autodrain (0);
1348		1750
1349	$asy	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
		1800	delete $SIG_CB{$signal}{$cb};
		1801
		1802	$HAVE_ASYNC_INTERRUPT
		1803	? delete $SIG_ASY{$signal}
		1804	: # delete doesn't work with older perls - they then
		1805	# print weird messages, or just unconditionally exit
		1806	# instead of getting the default action.
		1807	undef $SIG{$signal}
		1808	unless keys %{ $SIG_CB{$signal} };
1350	};	1809	};
1351		1810
1352	} else {	1811	*_signal_exec = sub {
1353	# pure perl	1812	$HAVE_ASYNC_INTERRUPT
		1813	? $SIGPIPE_R->drain
		1814	: sysread $SIGPIPE_R, (my $dummy), 9;
1354		1815
1355	$SIG{$signal} ||= sub {	1816	while (%SIG_EV) {
1356	local $!;	1817	for (keys %SIG_EV) {
1357	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;	1818	delete $SIG_EV{$_};
1358	undef $SIG_EV{$signal};	1819	&$_ for values %{ $SIG_CB{$_} || {} };
		1820	}
		1821	}
1359	};	1822	};
1360
1361	# can't do signal processing without introducing races in pure perl,
1362	# so limit the signal latency.
1363	_sig_add;
1364	}	1823	};
		1824	die if $@;
1365		1825
1366	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
1367	}
1368
1369	sub signal {
1370	# probe for availability of Async::Interrupt
1371	if (!$ENV{PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT} && eval "use Async::Interrupt 0.6 (); 1") {
1372	warn "AnyEvent: using Async::Interrupt for race-free signal handling.\n" if $VERBOSE >= 8;
1373
1374	$HAVE_ASYNC_INTERRUPT = 1;
1375	$SIGPIPE_R = new Async::Interrupt::EventPipe;
1376	$SIG_IO = AnyEvent->io (fh => $SIGPIPE_R->fileno, poll => "r", cb => \&_signal_exec);
1377
1378	} else {
1379	warn "AnyEvent: using emulated perl signal handling with latency timer.\n" if $VERBOSE >= 8;
1380
1381	require Fcntl;
1382
1383	if (AnyEvent::WIN32) {
1384	require AnyEvent::Util;
1385
1386	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
1387	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R) if $SIGPIPE_R;
1388	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W) if $SIGPIPE_W; # just in case
1389	} else {
1390	pipe $SIGPIPE_R, $SIGPIPE_W;
1391	fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R;
1392	fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case
1393
1394	# not strictly required, as $^F is normally 2, but let's make sure...
1395	fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
1396	fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
1397	}
1398
1399	$SIGPIPE_R
1400	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";
1401
1402	$SIG_IO = AnyEvent->io (fh => $SIGPIPE_R, poll => "r", cb => \&_signal_exec);
1403	}
1404
1405	*signal = \&_signal;
1406	&signal	1826	&signal
1407	}
1408
1409	sub AnyEvent::Base::signal::DESTROY {
1410	my ($signal, $cb) = @{$_[0]};
1411
1412	_sig_del;
1413
1414	delete $SIG_CB{$signal}{$cb};
1415
1416	$HAVE_ASYNC_INTERRUPT
1417	? delete $SIG_ASY{$signal}
1418	: # delete doesn't work with older perls - they then
1419	# print weird messages, or just unconditionally exit
1420	# instead of getting the default action.
1421	undef $SIG{$signal}
1422	unless keys %{ $SIG_CB{$signal} };
1423	}	1827	}
1424		1828
1425	# default implementation for ->child	1829	# default implementation for ->child
1426		1830
1427	our %PID_CB;	1831	our %PID_CB;
1428	our $CHLD_W;	1832	our $CHLD_W;
1429	our $CHLD_DELAY_W;	1833	our $CHLD_DELAY_W;
1430	our $WNOHANG;
1431		1834
		1835	# used by many Impl's
1432	sub _emit_childstatus($$) {	1836	sub _emit_childstatus($$) {
1433	my (undef, $rpid, $rstatus) = @_;	1837	my (undef, $rpid, $rstatus) = @_;
1434		1838
1435	$_->($rpid, $rstatus)	1839	$_->($rpid, $rstatus)
1436	for values %{ $PID_CB{$rpid} || {} },	1840	for values %{ $PID_CB{$rpid} || {} },
1437	values %{ $PID_CB{0} || {} };	1841	values %{ $PID_CB{0} || {} };
1438	}	1842	}
1439		1843
1440	sub _sigchld {
1441	my $pid;
1442
1443	AnyEvent->_emit_childstatus ($pid, $?)
1444	while ($pid = waitpid -1, $WNOHANG) > 0;
1445	}
1446
1447	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 {
1448	my (undef, %arg) = @_;	1854	my (undef, %arg) = @_;
1449		1855
1450	defined (my $pid = $arg{pid} + 0)	1856	my $pid = $arg{pid};
1451	or Carp::croak "required option 'pid' is missing";	1857	my $cb = $arg{cb};
1452		1858
1453	$PID_CB{$pid}{$arg{cb}} = $arg{cb};	1859	$PID_CB{$pid}{$cb+0} = $cb;
1454		1860
1455	# WNOHANG is almost cetrainly 1 everywhere
1456	$WNOHANG ||= $^O =~ /^(?:openbsd|netbsd|linux|freebsd|cygwin|MSWin32)$/
1457	? 1
1458	: eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1;
1459
1460	unless ($CHLD_W) {	1861	unless ($CHLD_W) {
1461	$CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld);	1862	$CHLD_W = AE::signal CHLD => \&_sigchld;
1462	# 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
1463	&_sigchld;	1864	&_sigchld;
1464	}	1865	}
1465		1866
1466	bless [$pid, $arg{cb}], "AnyEvent::Base::child"	1867	bless [$pid, $cb+0], "AnyEvent::Base::child"
1467	}	1868	};
1468		1869
1469	sub AnyEvent::Base::child::DESTROY {	1870	*AnyEvent::Base::child::DESTROY = sub {
1470	my ($pid, $cb) = @{$_[0]};	1871	my ($pid, $icb) = @{$_[0]};
1471		1872
1472	delete $PID_CB{$pid}{$cb};	1873	delete $PID_CB{$pid}{$icb};
1473	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };	1874	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };
1474		1875
1475	undef $CHLD_W unless keys %PID_CB;	1876	undef $CHLD_W unless keys %PID_CB;
		1877	};
		1878	};
		1879	die if $@;
		1880
		1881	&child
1476	}	1882	}
1477		1883
1478	# idle emulation is done by simply using a timer, regardless	1884	# idle emulation is done by simply using a timer, regardless
1479	# of whether the process is idle or not, and not letting	1885	# of whether the process is idle or not, and not letting
1480	# the callback use more than 50% of the time.	1886	# the callback use more than 50% of the time.
1481	sub idle {	1887	sub idle {
		1888	eval q{ # poor man's autoloading {}
		1889	*idle = sub {
1482	my (undef, %arg) = @_;	1890	my (undef, %arg) = @_;
1483		1891
1484	my ($cb, $w, $rcb) = $arg{cb};	1892	my ($cb, $w, $rcb) = $arg{cb};
1485		1893
1486	$rcb = sub {	1894	$rcb = sub {
1487	if ($cb) {	1895	if ($cb) {
1488	$w = _time;	1896	$w = AE::time;
1489	&$cb;	1897	&$cb;
1490	$w = _time - $w;	1898	$w = AE::time - $w;
1491		1899
1492	# 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,
1493	# within some limits	1901	# within some limits
1494	$w = 0.0001 if $w < 0.0001;	1902	$w = 0.0001 if $w < 0.0001;
1495	$w = 5 if $w > 5;	1903	$w = 5 if $w > 5;
1496		1904
1497	$w = AnyEvent->timer (after => $w, cb => $rcb);	1905	$w = AE::timer $w, 0, $rcb;
1498	} else {	1906	} else {
1499	# clean up...	1907	# clean up...
1500	undef $w;	1908	undef $w;
1501	undef $rcb;	1909	undef $rcb;
		1910	}
		1911	};
		1912
		1913	$w = AE::timer 0.05, 0, $rcb;
		1914
		1915	bless \\$cb, "AnyEvent::Base::idle"
1502	}	1916	};
		1917
		1918	*AnyEvent::Base::idle::DESTROY = sub {
		1919	undef $${$_[0]};
		1920	};
1503	};	1921	};
		1922	die if $@;
1504		1923
1505	$w = AnyEvent->timer (after => 0.05, cb => $rcb);	1924	&idle
1506
1507	bless \\$cb, "AnyEvent::Base::idle"
1508	}
1509
1510	sub AnyEvent::Base::idle::DESTROY {
1511	undef $${$_[0]};
1512	}	1925	}
1513		1926
1514	package AnyEvent::CondVar;	1927	package AnyEvent::CondVar;
1515		1928
1516	our @ISA = AnyEvent::CondVar::Base::;	1929	our @ISA = AnyEvent::CondVar::Base::;
		1930
		1931	# only to be used for subclassing
		1932	sub new {
		1933	my $class = shift;
		1934	bless AnyEvent->condvar (@_), $class
		1935	}
1517		1936
1518	package AnyEvent::CondVar::Base;	1937	package AnyEvent::CondVar::Base;
1519		1938
1520	#use overload	1939	#use overload
1521	# '&{}' => sub { my $self = shift; sub { $self->send (@_) } },	1940	# '&{}' => sub { my $self = shift; sub { $self->send (@_) } },
…		…
1531		1950
1532	sub _send {	1951	sub _send {
1533	# nop	1952	# nop
1534	}	1953	}
1535		1954
		1955	sub _wait {
		1956	AnyEvent->_poll until $_[0]{_ae_sent};
		1957	}
		1958
1536	sub send {	1959	sub send {
1537	my $cv = shift;	1960	my $cv = shift;
1538	$cv->{_ae_sent} = [@_];	1961	$cv->{_ae_sent} = [@_];
1539	(delete $cv->{_ae_cb})->($cv) if $cv->{_ae_cb};	1962	(delete $cv->{_ae_cb})->($cv) if $cv->{_ae_cb};
1540	$cv->_send;	1963	$cv->_send;
…		…
1547		1970
1548	sub ready {	1971	sub ready {
1549	$_[0]{_ae_sent}	1972	$_[0]{_ae_sent}
1550	}	1973	}
1551		1974
1552	sub _wait {
1553	$WAITING
1554	and !$_[0]{_ae_sent}
1555	and Carp::croak "AnyEvent::CondVar: recursive blocking wait detected";
1556
1557	local $WAITING = 1;
1558	AnyEvent->one_event while !$_[0]{_ae_sent};
1559	}
1560
1561	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;
1562	$_[0]->_wait;	1981	$_[0]->_wait;
		1982	}
1563		1983
1564	Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak};	1984	$_[0]{_ae_croak}
1565	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]
1566	}	1990	}
1567		1991
1568	sub cb {	1992	sub cb {
1569	$_[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
1570	$_[0]{_ae_cb}	2000	$cv->{_ae_cb}
1571	}	2001	}
1572		2002
1573	sub begin {	2003	sub begin {
1574	++$_[0]{_ae_counter};	2004	++$_[0]{_ae_counter};
1575	$_[0]{_ae_end_cb} = $_[1] if @_ > 1;	2005	$_[0]{_ae_end_cb} = $_[1] if @_ > 1;
…		…
1580	&{ $_[0]{_ae_end_cb} || sub { $_[0]->send } };	2010	&{ $_[0]{_ae_end_cb} || sub { $_[0]->send } };
1581	}	2011	}
1582		2012
1583	# undocumented/compatibility with pre-3.4	2013	# undocumented/compatibility with pre-3.4
1584	*broadcast = \&send;	2014	*broadcast = \&send;
1585	*wait = \&_wait;	2015	*wait = \&recv;
1586		2016
1587	=head1 ERROR AND EXCEPTION HANDLING	2017	=head1 ERROR AND EXCEPTION HANDLING
1588		2018
1589	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
1590	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
…		…
1602	$Event/EV::DIED->() >>, L<Glib> uses C<< install_exception_handler >> and	2032	$Event/EV::DIED->() >>, L<Glib> uses C<< install_exception_handler >> and
1603	so on.	2033	so on.
1604		2034
1605	=head1 ENVIRONMENT VARIABLES	2035	=head1 ENVIRONMENT VARIABLES
1606		2036
1607	The following environment variables are used by this module or its	2037	AnyEvent supports a number of environment variables that tune the
1608	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.
1609		2043
1610	Note that AnyEvent will remove I<all> environment variables starting with	2044	All the environment variables documented here start with
1611	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
1612	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:
1613		2074
1614	=over 4	2075	=over 4
1615		2076
1616	=item C<PERL_ANYEVENT_VERBOSE>	2077	=item C<PERL_ANYEVENT_VERBOSE>
1617		2078
1618	By default, AnyEvent will be completely silent except in fatal	2079	By default, AnyEvent will log messages with loglevel C<4> (C<error>) or
1619	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
1620	talkative.	2081	numerical loglevel to make AnyEvent more (or less) talkative.
1621		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
1622	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
1623	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
1624	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.
1625		2094
1626	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
1627	model it chooses.	2096	chooses.
1628		2097
1629	When set to C<8> or higher, then AnyEvent will report extra information on	2098	When set to C<8> or higher (debug), then AnyEvent will report extra
1630	which optional modules it loads and how it implements certain features.	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.
1631		2119
1632	=item C<PERL_ANYEVENT_STRICT>	2120	=item C<PERL_ANYEVENT_STRICT>
1633		2121
1634	AnyEvent does not do much argument checking by default, as thorough	2122	AnyEvent does not do much argument checking by default, as thorough
1635	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
…		…
1637	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,
1638	it will croak.	2126	it will croak.
1639		2127
1640	In other words, enables "strict" mode.	2128	In other words, enables "strict" mode.
1641		2129
1642	Unlike C<use strict> (or it's modern cousin, C<< use L<common::sense>	2130	Unlike C<use strict> (or its modern cousin, C<< use L<common::sense>
1643	>>, it is definitely recommended to keep it off in production. Keeping	2131	>>, it is definitely recommended to keep it off in production. Keeping
1644	C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs	2132	C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs
1645	can be very useful, however.	2133	can be very useful, however.
1646		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.
		2162
1647	=item C<PERL_ANYEVENT_MODEL>	2163	=item C<PERL_ANYEVENT_MODEL>
1648		2164
1649	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
1650	auto detection and -probing kicks in. It must be a string consisting	2166	auto detection and -probing kicks in.
1651	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
1652	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
1653	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
1654	auto detection and -probing.	2172	auto detection and -probing.
1655		2173
1656	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).
1657		2177
1658	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
1659	could start your program like this:	2179	could start your program like this:
1660		2180
1661	PERL_ANYEVENT_MODEL=Perl perl ...	2181	PERL_ANYEVENT_MODEL=Perl perl ...
		2182
		2183	=item C<PERL_ANYEVENT_IO_MODEL>
		2184
		2185	The current file I/O model - see L<AnyEvent::IO> for more info.
		2186
		2187	At the moment, only C<Perl> (small, pure-perl, synchronous) and
		2188	C<IOAIO> (truly asynchronous) are supported. The default is C<IOAIO> if
		2189	L<AnyEvent::AIO> can be loaded, otherwise it is C<Perl>.
1662		2190
1663	=item C<PERL_ANYEVENT_PROTOCOLS>	2191	=item C<PERL_ANYEVENT_PROTOCOLS>
1664		2192
1665	Used by both L<AnyEvent::DNS> and L<AnyEvent::Socket> to determine preferences	2193	Used by both L<AnyEvent::DNS> and L<AnyEvent::Socket> to determine preferences
1666	for IPv4 or IPv6. The default is unspecified (and might change, or be the result	2194	for IPv4 or IPv6. The default is unspecified (and might change, or be the result
…		…
1679	but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4>	2207	but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4>
1680	- only support IPv4, never try to resolve or contact IPv6	2208	- only support IPv4, never try to resolve or contact IPv6
1681	addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or	2209	addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or
1682	IPv6, but prefer IPv6 over IPv4.	2210	IPv6, but prefer IPv6 over IPv4.
1683		2211
		2212	=item C<PERL_ANYEVENT_HOSTS>
		2213
		2214	This variable, if specified, overrides the F</etc/hosts> file used by
		2215	L<AnyEvent::Socket>C<::resolve_sockaddr>, i.e. hosts aliases will be read
		2216	from that file instead.
		2217
1684	=item C<PERL_ANYEVENT_EDNS0>	2218	=item C<PERL_ANYEVENT_EDNS0>
1685		2219
1686	Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension	2220	Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension for
1687	for DNS. This extension is generally useful to reduce DNS traffic, but	2221	DNS. This extension is generally useful to reduce DNS traffic, especially
1688	some (broken) firewalls drop such DNS packets, which is why it is off by	2222	when DNSSEC is involved, but some (broken) firewalls drop such DNS
1689	default.	2223	packets, which is why it is off by default.
1690		2224
1691	Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce	2225	Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce
1692	EDNS0 in its DNS requests.	2226	EDNS0 in its DNS requests.
1693		2227
1694	=item C<PERL_ANYEVENT_MAX_FORKS>	2228	=item C<PERL_ANYEVENT_MAX_FORKS>
…		…
1700		2234
1701	The default value for the C<max_outstanding> parameter for the default DNS	2235	The default value for the C<max_outstanding> parameter for the default DNS
1702	resolver - this is the maximum number of parallel DNS requests that are	2236	resolver - this is the maximum number of parallel DNS requests that are
1703	sent to the DNS server.	2237	sent to the DNS server.
1704		2238
		2239	=item C<PERL_ANYEVENT_MAX_SIGNAL_LATENCY>
		2240
		2241	Perl has inherently racy signal handling (you can basically choose between
		2242	losing signals and memory corruption) - pure perl event loops (including
		2243	C<AnyEvent::Loop>, when C<Async::Interrupt> isn't available) therefore
		2244	have to poll regularly to avoid losing signals.
		2245
		2246	Some event loops are racy, but don't poll regularly, and some event loops
		2247	are written in C but are still racy. For those event loops, AnyEvent
		2248	installs a timer that regularly wakes up the event loop.
		2249
		2250	By default, the interval for this timer is C<10> seconds, but you can
		2251	override this delay with this environment variable (or by setting
		2252	the C<$AnyEvent::MAX_SIGNAL_LATENCY> variable before creating signal
		2253	watchers).
		2254
		2255	Lower values increase CPU (and energy) usage, higher values can introduce
		2256	long delays when reaping children or waiting for signals.
		2257
		2258	The L<AnyEvent::Async> module, if available, will be used to avoid this
		2259	polling (with most event loops).
		2260
1705	=item C<PERL_ANYEVENT_RESOLV_CONF>	2261	=item C<PERL_ANYEVENT_RESOLV_CONF>
1706		2262
1707	The file to use instead of F</etc/resolv.conf> (or OS-specific	2263	The absolute path to a F<resolv.conf>-style file to use instead of
1708	configuration) in the default resolver. When set to the empty string, no	2264	F</etc/resolv.conf> (or the OS-specific configuration) in the default
1709	default config will be used.	2265	resolver, or the empty string to select the default configuration.
1710		2266
1711	=item C<PERL_ANYEVENT_CA_FILE>, C<PERL_ANYEVENT_CA_PATH>.	2267	=item C<PERL_ANYEVENT_CA_FILE>, C<PERL_ANYEVENT_CA_PATH>.
1712		2268
1713	When neither C<ca_file> nor C<ca_path> was specified during	2269	When neither C<ca_file> nor C<ca_path> was specified during
1714	L<AnyEvent::TLS> context creation, and either of these environment	2270	L<AnyEvent::TLS> context creation, and either of these environment
1715	variables exist, they will be used to specify CA certificate locations	2271	variables are nonempty, they will be used to specify CA certificate
1716	instead of a system-dependent default.	2272	locations instead of a system-dependent default.
1717		2273
1718	=item C<PERL_ANYEVENT_AVOID_GUARD> and C<PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT>	2274	=item C<PERL_ANYEVENT_AVOID_GUARD> and C<PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT>
1719		2275
1720	When these are set to C<1>, then the respective modules are not	2276	When these are set to C<1>, then the respective modules are not
1721	loaded. Mostly good for testing AnyEvent itself.	2277	loaded. Mostly good for testing AnyEvent itself.
…		…
1784	warn "read: $input\n"; # output what has been read	2340	warn "read: $input\n"; # output what has been read
1785	$cv->send if $input =~ /^q/i; # quit program if /^q/i	2341	$cv->send if $input =~ /^q/i; # quit program if /^q/i
1786	},	2342	},
1787	);	2343	);
1788		2344
1789	my $time_watcher; # can only be used once
1790
1791	sub new_timer {
1792	$timer = AnyEvent->timer (after => 1, cb => sub {	2345	my $time_watcher = AnyEvent->timer (after => 1, interval => 1, cb => sub {
1793	warn "timeout\n"; # print 'timeout' about every second	2346	warn "timeout\n"; # print 'timeout' at most every second
1794	&new_timer; # and restart the time
1795	});	2347	});
1796	}
1797
1798	new_timer; # create first timer
1799		2348
1800	$cv->recv; # wait until user enters /^q/i	2349	$cv->recv; # wait until user enters /^q/i
1801		2350
1802	=head1 REAL-WORLD EXAMPLE	2351	=head1 REAL-WORLD EXAMPLE
1803		2352
…		…
1876		2425
1877	The actual code goes further and collects all errors (C<die>s, exceptions)	2426	The actual code goes further and collects all errors (C<die>s, exceptions)
1878	that occurred during request processing. The C<result> method detects	2427	that occurred during request processing. The C<result> method detects
1879	whether an exception as thrown (it is stored inside the $txn object)	2428	whether an exception as thrown (it is stored inside the $txn object)
1880	and just throws the exception, which means connection errors and other	2429	and just throws the exception, which means connection errors and other
1881	problems get reported tot he code that tries to use the result, not in a	2430	problems get reported to the code that tries to use the result, not in a
1882	random callback.	2431	random callback.
1883		2432
1884	All of this enables the following usage styles:	2433	All of this enables the following usage styles:
1885		2434
1886	1. Blocking:	2435	1. Blocking:
…		…
1934	through AnyEvent. The benchmark creates a lot of timers (with a zero	2483	through AnyEvent. The benchmark creates a lot of timers (with a zero
1935	timeout) and I/O watchers (watching STDOUT, a pty, to become writable,	2484	timeout) and I/O watchers (watching STDOUT, a pty, to become writable,
1936	which it is), lets them fire exactly once and destroys them again.	2485	which it is), lets them fire exactly once and destroys them again.
1937		2486
1938	Source code for this benchmark is found as F<eg/bench> in the AnyEvent	2487	Source code for this benchmark is found as F<eg/bench> in the AnyEvent
1939	distribution.	2488	distribution. It uses the L<AE> interface, which makes a real difference
		2489	for the EV and Perl backends only.
1940		2490
1941	=head3 Explanation of the columns	2491	=head3 Explanation of the columns
1942		2492
1943	I<watcher> is the number of event watchers created/destroyed. Since	2493	I<watcher> is the number of event watchers created/destroyed. Since
1944	different event models feature vastly different performances, each event	2494	different event models feature vastly different performances, each event
…		…
1965	watcher.	2515	watcher.
1966		2516
1967	=head3 Results	2517	=head3 Results
1968		2518
1969	name watchers bytes create invoke destroy comment	2519	name watchers bytes create invoke destroy comment
1970	EV/EV 400000 224 0.47 0.35 0.27 EV native interface	2520	EV/EV 100000 223 0.47 0.43 0.27 EV native interface
1971	EV/Any 100000 224 2.88 0.34 0.27 EV + AnyEvent watchers	2521	EV/Any 100000 223 0.48 0.42 0.26 EV + AnyEvent watchers
1972	CoroEV/Any 100000 224 2.85 0.35 0.28 coroutines + Coro::Signal	2522	Coro::EV/Any 100000 223 0.47 0.42 0.26 coroutines + Coro::Signal
1973	Perl/Any 100000 452 4.13 0.73 0.95 pure perl implementation	2523	Perl/Any 100000 431 2.70 0.74 0.92 pure perl implementation
1974	Event/Event 16000 517 32.20 31.80 0.81 Event native interface	2524	Event/Event 16000 516 31.16 31.84 0.82 Event native interface
1975	Event/Any 16000 590 35.85 31.55 1.06 Event + AnyEvent watchers	2525	Event/Any 16000 1203 42.61 34.79 1.80 Event + AnyEvent watchers
1976	IOAsync/Any 16000 989 38.10 32.77 11.13 via IO::Async::Loop::IO_Poll	2526	IOAsync/Any 16000 1911 41.92 27.45 16.81 via IO::Async::Loop::IO_Poll
1977	IOAsync/Any 16000 990 37.59 29.50 10.61 via IO::Async::Loop::Epoll	2527	IOAsync/Any 16000 1726 40.69 26.37 15.25 via IO::Async::Loop::Epoll
1978	Glib/Any 16000 1357 102.33 12.31 51.00 quadratic behaviour	2528	Glib/Any 16000 1118 89.00 12.57 51.17 quadratic behaviour
1979	Tk/Any 2000 1860 27.20 66.31 14.00 SEGV with >> 2000 watchers	2529	Tk/Any 2000 1346 20.96 10.75 8.00 SEGV with >> 2000 watchers
1980	POE/Event 2000 6328 109.99 751.67 14.02 via POE::Loop::Event	2530	POE/Any 2000 6951 108.97 795.32 14.24 via POE::Loop::Event
1981	POE/Select 2000 6027 94.54 809.13 579.80 via POE::Loop::Select	2531	POE/Any 2000 6648 94.79 774.40 575.51 via POE::Loop::Select
1982		2532
1983	=head3 Discussion	2533	=head3 Discussion
1984		2534
1985	The benchmark does I<not> measure scalability of the event loop very	2535	The benchmark does I<not> measure scalability of the event loop very
1986	well. For example, a select-based event loop (such as the pure perl one)	2536	well. For example, a select-based event loop (such as the pure perl one)
…		…
1998	benchmark machine, handling an event takes roughly 1600 CPU cycles with	2548	benchmark machine, handling an event takes roughly 1600 CPU cycles with
1999	EV, 3100 CPU cycles with AnyEvent's pure perl loop and almost 3000000 CPU	2549	EV, 3100 CPU cycles with AnyEvent's pure perl loop and almost 3000000 CPU
2000	cycles with POE.	2550	cycles with POE.
2001		2551
2002	C<EV> is the sole leader regarding speed and memory use, which are both	2552	C<EV> is the sole leader regarding speed and memory use, which are both
2003	maximal/minimal, respectively. Even when going through AnyEvent, it uses	2553	maximal/minimal, respectively. When using the L<AE> API there is zero
		2554	overhead (when going through the AnyEvent API create is about 5-6 times
		2555	slower, with other times being equal, so still uses far less memory than
2004	far less memory than any other event loop and is still faster than Event	2556	any other event loop and is still faster than Event natively).
2005	natively.
2006		2557
2007	The pure perl implementation is hit in a few sweet spots (both the	2558	The pure perl implementation is hit in a few sweet spots (both the
2008	constant timeout and the use of a single fd hit optimisations in the perl	2559	constant timeout and the use of a single fd hit optimisations in the perl
2009	interpreter and the backend itself). Nevertheless this shows that it	2560	interpreter and the backend itself). Nevertheless this shows that it
2010	adds very little overhead in itself. Like any select-based backend its	2561	adds very little overhead in itself. Like any select-based backend its
…		…
2058	(even when used without AnyEvent), but most event loops have acceptable	2609	(even when used without AnyEvent), but most event loops have acceptable
2059	performance with or without AnyEvent.	2610	performance with or without AnyEvent.
2060		2611
2061	=item * The overhead AnyEvent adds is usually much smaller than the overhead of	2612	=item * The overhead AnyEvent adds is usually much smaller than the overhead of
2062	the actual event loop, only with extremely fast event loops such as EV	2613	the actual event loop, only with extremely fast event loops such as EV
2063	adds AnyEvent significant overhead.	2614	does AnyEvent add significant overhead.
2064		2615
2065	=item * You should avoid POE like the plague if you want performance or	2616	=item * You should avoid POE like the plague if you want performance or
2066	reasonable memory usage.	2617	reasonable memory usage.
2067		2618
2068	=back	2619	=back
…		…
2084	In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100	2635	In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100
2085	(1%) are active. This mirrors the activity of large servers with many	2636	(1%) are active. This mirrors the activity of large servers with many
2086	connections, most of which are idle at any one point in time.	2637	connections, most of which are idle at any one point in time.
2087		2638
2088	Source code for this benchmark is found as F<eg/bench2> in the AnyEvent	2639	Source code for this benchmark is found as F<eg/bench2> in the AnyEvent
2089	distribution.	2640	distribution. It uses the L<AE> interface, which makes a real difference
		2641	for the EV and Perl backends only.
2090		2642
2091	=head3 Explanation of the columns	2643	=head3 Explanation of the columns
2092		2644
2093	I<sockets> is the number of sockets, and twice the number of "servers" (as	2645	I<sockets> is the number of sockets, and twice the number of "servers" (as
2094	each server has a read and write socket end).	2646	each server has a read and write socket end).
…		…
2102	a new one that moves the timeout into the future.	2654	a new one that moves the timeout into the future.
2103		2655
2104	=head3 Results	2656	=head3 Results
2105		2657
2106	name sockets create request	2658	name sockets create request
2107	EV 20000 69.01 11.16	2659	EV 20000 62.66 7.99
2108	Perl 20000 73.32 35.87	2660	Perl 20000 68.32 32.64
2109	IOAsync 20000 157.00 98.14 epoll	2661	IOAsync 20000 174.06 101.15 epoll
2110	IOAsync 20000 159.31 616.06 poll	2662	IOAsync 20000 174.67 610.84 poll
2111	Event 20000 212.62 257.32	2663	Event 20000 202.69 242.91
2112	Glib 20000 651.16 1896.30	2664	Glib 20000 557.01 1689.52
2113	POE 20000 349.67 12317.24 uses POE::Loop::Event	2665	POE 20000 341.54 12086.32 uses POE::Loop::Event
2114		2666
2115	=head3 Discussion	2667	=head3 Discussion
2116		2668
2117	This benchmark I<does> measure scalability and overall performance of the	2669	This benchmark I<does> measure scalability and overall performance of the
2118	particular event loop.	2670	particular event loop.
…		…
2244	As you can see, the AnyEvent + EV combination even beats the	2796	As you can see, the AnyEvent + EV combination even beats the
2245	hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl	2797	hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl
2246	backend easily beats IO::Lambda and POE.	2798	backend easily beats IO::Lambda and POE.
2247		2799
2248	And even the 100% non-blocking version written using the high-level (and	2800	And even the 100% non-blocking version written using the high-level (and
2249	slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda by a	2801	slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda
2250	large margin, even though it does all of DNS, tcp-connect and socket I/O	2802	higher level ("unoptimised") abstractions by a large margin, even though
2251	in a non-blocking way.	2803	it does all of DNS, tcp-connect and socket I/O in a non-blocking way.
2252		2804
2253	The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and	2805	The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and
2254	F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are	2806	F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are
2255	part of the IO::lambda distribution and were used without any changes.	2807	part of the IO::Lambda distribution and were used without any changes.
2256		2808
2257		2809
2258	=head1 SIGNALS	2810	=head1 SIGNALS
2259		2811
2260	AnyEvent currently installs handlers for these signals:	2812	AnyEvent currently installs handlers for these signals:
…		…
2297	unless defined $SIG{PIPE};	2849	unless defined $SIG{PIPE};
2298		2850
2299	=head1 RECOMMENDED/OPTIONAL MODULES	2851	=head1 RECOMMENDED/OPTIONAL MODULES
2300		2852
2301	One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and	2853	One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and
2302	it's built-in modules) are required to use it.	2854	its built-in modules) are required to use it.
2303		2855
2304	That does not mean that AnyEvent won't take advantage of some additional	2856	That does not mean that AnyEvent won't take advantage of some additional
2305	modules if they are installed.	2857	modules if they are installed.
2306		2858
2307	This section epxlains which additional modules will be used, and how they	2859	This section explains which additional modules will be used, and how they
2308	affect AnyEvent's operetion.	2860	affect AnyEvent's operation.
2309		2861
2310	=over 4	2862	=over 4
2311		2863
2312	=item L<Async::Interrupt>	2864	=item L<Async::Interrupt>
2313		2865
…		…
2318	catch the signals) with some delay (default is 10 seconds, look for	2870	catch the signals) with some delay (default is 10 seconds, look for
2319	C<$AnyEvent::MAX_SIGNAL_LATENCY>).	2871	C<$AnyEvent::MAX_SIGNAL_LATENCY>).
2320		2872
2321	If this module is available, then it will be used to implement signal	2873	If this module is available, then it will be used to implement signal
2322	catching, which means that signals will not be delayed, and the event loop	2874	catching, which means that signals will not be delayed, and the event loop
2323	will not be interrupted regularly, which is more efficient (And good for	2875	will not be interrupted regularly, which is more efficient (and good for
2324	battery life on laptops).	2876	battery life on laptops).
2325		2877
2326	This affects not just the pure-perl event loop, but also other event loops	2878	This affects not just the pure-perl event loop, but also other event loops
2327	that have no signal handling on their own (e.g. Glib, Tk, Qt).	2879	that have no signal handling on their own (e.g. Glib, Tk, Qt).
2328		2880
…		…
2340	automatic timer adjustments even when no monotonic clock is available,	2892	automatic timer adjustments even when no monotonic clock is available,
2341	can take avdantage of advanced kernel interfaces such as C<epoll> and	2893	can take avdantage of advanced kernel interfaces such as C<epoll> and
2342	C<kqueue>, and is the fastest backend I<by far>. You can even embed	2894	C<kqueue>, and is the fastest backend I<by far>. You can even embed
2343	L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>).	2895	L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>).
2344		2896
		2897	If you only use backends that rely on another event loop (e.g. C<Tk>),
		2898	then this module will do nothing for you.
		2899
2345	=item L<Guard>	2900	=item L<Guard>
2346		2901
2347	The guard module, when used, will be used to implement	2902	The guard module, when used, will be used to implement
2348	C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a	2903	C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a
2349	lot less memory), but otherwise doesn't affect guard operation much. It is	2904	lot less memory), but otherwise doesn't affect guard operation much. It is
2350	purely used for performance.	2905	purely used for performance.
2351		2906
2352	=item L<JSON> and L<JSON::XS>	2907	=item L<JSON> and L<JSON::XS>
2353		2908
2354	This module is required when you want to read or write JSON data via	2909	One of these modules is required when you want to read or write JSON data
2355	L<AnyEvent::Handle>. It is also written in pure-perl, but can take	2910	via L<AnyEvent::Handle>. L<JSON> is also written in pure-perl, but can take
2356	advantage of the ultra-high-speed L<JSON::XS> module when it is installed.	2911	advantage of the ultra-high-speed L<JSON::XS> module when it is installed.
2357
2358	In fact, L<AnyEvent::Handle> will use L<JSON::XS> by default if it is
2359	installed.
2360		2912
2361	=item L<Net::SSLeay>	2913	=item L<Net::SSLeay>
2362		2914
2363	Implementing TLS/SSL in Perl is certainly interesting, but not very	2915	Implementing TLS/SSL in Perl is certainly interesting, but not very
2364	worthwhile: If this module is installed, then L<AnyEvent::Handle> (with	2916	worthwhile: If this module is installed, then L<AnyEvent::Handle> (with
2365	the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL.	2917	the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL.
2366		2918
2367	=item L<Time::HiRes>	2919	=item L<Time::HiRes>
2368		2920
2369	This module is part of perl since release 5.008. It will be used when the	2921	This module is part of perl since release 5.008. It will be used when the
2370	chosen event library does not come with a timing source on it's own. The	2922	chosen event library does not come with a timing source of its own. The
2371	pure-perl event loop (L<AnyEvent::Impl::Perl>) will additionally use it to	2923	pure-perl event loop (L<AnyEvent::Loop>) will additionally load it to
2372	try to use a monotonic clock for timing stability.	2924	try to use a monotonic clock for timing stability.
2373		2925
2374	=back	2926	=back
2375		2927
2376		2928
2377	=head1 FORK	2929	=head1 FORK
2378		2930
2379	Most event libraries are not fork-safe. The ones who are usually are	2931	Most event libraries are not fork-safe. The ones who are usually are
2380	because they rely on inefficient but fork-safe C<select> or C<poll>	2932	because they rely on inefficient but fork-safe C<select> or C<poll> calls
2381	calls. Only L<EV> is fully fork-aware.	2933	- higher performance APIs such as BSD's kqueue or the dreaded Linux epoll
		2934	are usually badly thought-out hacks that are incompatible with fork in
		2935	one way or another. Only L<EV> is fully fork-aware and ensures that you
		2936	continue event-processing in both parent and child (or both, if you know
		2937	what you are doing).
		2938
		2939	This means that, in general, you cannot fork and do event processing in
		2940	the child if the event library was initialised before the fork (which
		2941	usually happens when the first AnyEvent watcher is created, or the library
		2942	is loaded).
2382		2943
2383	If you have to fork, you must either do so I<before> creating your first	2944	If you have to fork, you must either do so I<before> creating your first
2384	watcher OR you must not use AnyEvent at all in the child OR you must do	2945	watcher OR you must not use AnyEvent at all in the child OR you must do
2385	something completely out of the scope of AnyEvent.	2946	something completely out of the scope of AnyEvent.
		2947
		2948	The problem of doing event processing in the parent I<and> the child
		2949	is much more complicated: even for backends that I<are> fork-aware or
		2950	fork-safe, their behaviour is not usually what you want: fork clones all
		2951	watchers, that means all timers, I/O watchers etc. are active in both
		2952	parent and child, which is almost never what you want. USing C<exec>
		2953	to start worker children from some kind of manage rprocess is usually
		2954	preferred, because it is much easier and cleaner, at the expense of having
		2955	to have another binary.
2386		2956
2387		2957
2388	=head1 SECURITY CONSIDERATIONS	2958	=head1 SECURITY CONSIDERATIONS
2389		2959
2390	AnyEvent can be forced to load any event model via	2960	AnyEvent can be forced to load any event model via
…		…
2420	pronounced).	2990	pronounced).
2421		2991
2422		2992
2423	=head1 SEE ALSO	2993	=head1 SEE ALSO
2424		2994
2425	Utility functions: L<AnyEvent::Util>.	2995	Tutorial/Introduction: L<AnyEvent::Intro>.
2426		2996
2427	Event modules: L<EV>, L<EV::Glib>, L<Glib::EV>, L<Event>, L<Glib::Event>,	2997	FAQ: L<AnyEvent::FAQ>.
2428	L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.	2998
		2999	Utility functions: L<AnyEvent::Util> (misc. grab-bag), L<AnyEvent::Log>
		3000	(simply logging).
		3001
		3002	Development/Debugging: L<AnyEvent::Strict> (stricter checking),
		3003	L<AnyEvent::Debug> (interactive shell, watcher tracing).
		3004
		3005	Supported event modules: L<AnyEvent::Loop>, L<EV>, L<EV::Glib>,
		3006	L<Glib::EV>, L<Event>, L<Glib::Event>, L<Glib>, L<Tk>, L<Event::Lib>,
		3007	L<Qt>, L<POE>, L<FLTK>.
2429		3008
2430	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,	3009	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,
2431	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,	3010	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,
2432	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,	3011	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,
2433	L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>, L<Anyevent::Impl::Irssi>.	3012	L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>, L<Anyevent::Impl::Irssi>,
		3013	L<AnyEvent::Impl::FLTK>.
2434		3014
2435	Non-blocking file handles, sockets, TCP clients and	3015	Non-blocking handles, pipes, stream sockets, TCP clients and
2436	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.	3016	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.
2437		3017
		3018	Asynchronous File I/O: L<AnyEvent::IO>.
		3019
2438	Asynchronous DNS: L<AnyEvent::DNS>.	3020	Asynchronous DNS: L<AnyEvent::DNS>.
2439		3021
2440	Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>,	3022	Thread support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>.
2441	L<Coro::Event>,
2442		3023
2443	Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::XMPP>,	3024	Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::IRC>,
2444	L<AnyEvent::HTTP>.	3025	L<AnyEvent::HTTP>.
2445		3026
2446		3027
2447	=head1 AUTHOR	3028	=head1 AUTHOR
2448		3029
2449	Marc Lehmann <schmorp@schmorp.de>	3030	Marc Lehmann <schmorp@schmorp.de>
2450	http://home.schmorp.de/	3031	http://anyevent.schmorp.de
2451		3032
2452	=cut	3033	=cut
2453		3034
2454	1	3035	1
2455		3036

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