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Revision 1.371 by root, Wed Aug 24 23:59:10 2011 UTC

1	=head1 NAME	1	=head1 NAME
2		2
3	AnyEvent - provide framework for multiple event loops	3	AnyEvent - the DBI of event loop programming
4		4
5	EV, Event, Glib, Tk, Perl, Event::Lib, Qt and POE are various supported	5	EV, Event, Glib, Tk, Perl, Event::Lib, Irssi, rxvt-unicode, IO::Async, Qt,
6	event loops.	6	FLTK and POE are various supported event loops/environments.
7		7
8	=head1 SYNOPSIS	8	=head1 SYNOPSIS
9		9
10	use AnyEvent;	10	use AnyEvent;
11		11
		12	# if you prefer function calls, look at the AE manpage for
		13	# an alternative API.
		14
12	# file descriptor readable	15	# file handle or descriptor readable
13	my $w = AnyEvent->io (fh => $fh, poll => "r", cb => sub { ... });	16	my $w = AnyEvent->io (fh => $fh, poll => "r", cb => sub { ... });
14		17
15	# one-shot or repeating timers	18	# one-shot or repeating timers
16	my $w = AnyEvent->timer (after => $seconds, cb => sub { ... });	19	my $w = AnyEvent->timer (after => $seconds, cb => sub { ... });
17	my $w = AnyEvent->timer (after => $seconds, interval => $seconds, cb => ...	20	my $w = AnyEvent->timer (after => $seconds, interval => $seconds, cb => ...);
18		21
19	print AnyEvent->now; # prints current event loop time	22	print AnyEvent->now; # prints current event loop time
20	print AnyEvent->time; # think Time::HiRes::time or simply CORE::time.	23	print AnyEvent->time; # think Time::HiRes::time or simply CORE::time.
21		24
22	# POSIX signal	25	# POSIX signal
…		…
40	=head1 INTRODUCTION/TUTORIAL	43	=head1 INTRODUCTION/TUTORIAL
41		44
42	This manpage is mainly a reference manual. If you are interested	45	This manpage is mainly a reference manual. If you are interested
43	in a tutorial or some gentle introduction, have a look at the	46	in a tutorial or some gentle introduction, have a look at the
44	L<AnyEvent::Intro> manpage.	47	L<AnyEvent::Intro> manpage.
		48
		49	=head1 SUPPORT
		50
		51	An FAQ document is available as L<AnyEvent::FAQ>.
		52
		53	There also is a mailinglist for discussing all things AnyEvent, and an IRC
		54	channel, too.
		55
		56	See the AnyEvent project page at the B<Schmorpforge Ta-Sa Software
		57	Repository>, at L<http://anyevent.schmorp.de>, for more info.
45		58
46	=head1 WHY YOU SHOULD USE THIS MODULE (OR NOT)	59	=head1 WHY YOU SHOULD USE THIS MODULE (OR NOT)
47		60
48	Glib, POE, IO::Async, Event... CPAN offers event models by the dozen	61	Glib, POE, IO::Async, Event... CPAN offers event models by the dozen
49	nowadays. So what is different about AnyEvent?	62	nowadays. So what is different about AnyEvent?
…		…
65	module users into the same thing by forcing them to use the same event	78	module users into the same thing by forcing them to use the same event
66	model you use.	79	model you use.
67		80
68	For modules like POE or IO::Async (which is a total misnomer as it is	81	For modules like POE or IO::Async (which is a total misnomer as it is
69	actually doing all I/O I<synchronously>...), using them in your module is	82	actually doing all I/O I<synchronously>...), using them in your module is
70	like joining a cult: After you joined, you are dependent on them and you	83	like joining a cult: After you join, you are dependent on them and you
71	cannot use anything else, as they are simply incompatible to everything	84	cannot use anything else, as they are simply incompatible to everything
72	that isn't them. What's worse, all the potential users of your	85	that isn't them. What's worse, all the potential users of your
73	module are I<also> forced to use the same event loop you use.	86	module are I<also> forced to use the same event loop you use.
74		87
75	AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works	88	AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works
76	fine. AnyEvent + Tk works fine etc. etc. but none of these work together	89	fine. AnyEvent + Tk works fine etc. etc. but none of these work together
77	with the rest: POE + IO::Async? No go. Tk + Event? No go. Again: if	90	with the rest: POE + EV? No go. Tk + Event? No go. Again: if your module
78	your module uses one of those, every user of your module has to use it,	91	uses one of those, every user of your module has to use it, too. But if
79	too. But if your module uses AnyEvent, it works transparently with all	92	your module uses AnyEvent, it works transparently with all event models it
80	event models it supports (including stuff like IO::Async, as long as those	93	supports (including stuff like IO::Async, as long as those use one of the
81	use one of the supported event loops. It is trivial to add new event loops	94	supported event loops. It is easy to add new event loops to AnyEvent, too,
82	to AnyEvent, too, so it is future-proof).	95	so it is future-proof).
83		96
84	In addition to being free of having to use I<the one and only true event	97	In addition to being free of having to use I<the one and only true event
85	model>, AnyEvent also is free of bloat and policy: with POE or similar	98	model>, AnyEvent also is free of bloat and policy: with POE or similar
86	modules, you get an enormous amount of code and strict rules you have to	99	modules, you get an enormous amount of code and strict rules you have to
87	follow. AnyEvent, on the other hand, is lean and up to the point, by only	100	follow. AnyEvent, on the other hand, is lean and to the point, by only
88	offering the functionality that is necessary, in as thin as a wrapper as	101	offering the functionality that is necessary, in as thin as a wrapper as
89	technically possible.	102	technically possible.
90		103
91	Of course, AnyEvent comes with a big (and fully optional!) toolbox	104	Of course, AnyEvent comes with a big (and fully optional!) toolbox
92	of useful functionality, such as an asynchronous DNS resolver, 100%	105	of useful functionality, such as an asynchronous DNS resolver, 100%
…		…
98	useful) and you want to force your users to use the one and only event	111	useful) and you want to force your users to use the one and only event
99	model, you should I<not> use this module.	112	model, you should I<not> use this module.
100		113
101	=head1 DESCRIPTION	114	=head1 DESCRIPTION
102		115
103	L<AnyEvent> provides an identical interface to multiple event loops. This	116	L<AnyEvent> provides a uniform interface to various event loops. This
104	allows module authors to utilise an event loop without forcing module	117	allows module authors to use event loop functionality without forcing
105	users to use the same event loop (as only a single event loop can coexist	118	module users to use a specific event loop implementation (since more
106	peacefully at any one time).	119	than one event loop cannot coexist peacefully).
107		120
108	The interface itself is vaguely similar, but not identical to the L<Event>	121	The interface itself is vaguely similar, but not identical to the L<Event>
109	module.	122	module.
110		123
111	During the first call of any watcher-creation method, the module tries	124	During the first call of any watcher-creation method, the module tries
112	to detect the currently loaded event loop by probing whether one of the	125	to detect the currently loaded event loop by probing whether one of the
113	following modules is already loaded: L<EV>,	126	following modules is already loaded: L<EV>, L<AnyEvent::Loop>,
114	L<Event>, L<Glib>, L<AnyEvent::Impl::Perl>, L<Tk>, L<Event::Lib>, L<Qt>,	127	L<Event>, L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>. The first one
115	L<POE>. The first one found is used. If none are found, the module tries	128	found is used. If none are detected, the module tries to load the first
116	to load these modules (excluding Tk, Event::Lib, Qt and POE as the pure perl	129	four modules in the order given; but note that if L<EV> is not
117	adaptor should always succeed) in the order given. The first one that can	130	available, the pure-perl L<AnyEvent::Loop> should always work, so
118	be successfully loaded will be used. If, after this, still none could be	131	the other two are not normally tried.
119	found, AnyEvent will fall back to a pure-perl event loop, which is not
120	very efficient, but should work everywhere.
121		132
122	Because AnyEvent first checks for modules that are already loaded, loading	133	Because AnyEvent first checks for modules that are already loaded, loading
123	an event model explicitly before first using AnyEvent will likely make	134	an event model explicitly before first using AnyEvent will likely make
124	that model the default. For example:	135	that model the default. For example:
125		136
…		…
127	use AnyEvent;	138	use AnyEvent;
128		139
129	# .. AnyEvent will likely default to Tk	140	# .. AnyEvent will likely default to Tk
130		141
131	The I<likely> means that, if any module loads another event model and	142	The I<likely> means that, if any module loads another event model and
132	starts using it, all bets are off. Maybe you should tell their authors to	143	starts using it, all bets are off - this case should be very rare though,
133	use AnyEvent so their modules work together with others seamlessly...	144	as very few modules hardcode event loops without announcing this very
		145	loudly.
134		146
135	The pure-perl implementation of AnyEvent is called	147	The pure-perl implementation of AnyEvent is called C<AnyEvent::Loop>. Like
136	C<AnyEvent::Impl::Perl>. Like other event modules you can load it	148	other event modules you can load it explicitly and enjoy the high
137	explicitly and enjoy the high availability of that event loop :)	149	availability of that event loop :)
138		150
139	=head1 WATCHERS	151	=head1 WATCHERS
140		152
141	AnyEvent has the central concept of a I<watcher>, which is an object that	153	AnyEvent has the central concept of a I<watcher>, which is an object that
142	stores relevant data for each kind of event you are waiting for, such as	154	stores relevant data for each kind of event you are waiting for, such as
…		…
147	callback when the event occurs (of course, only when the event model	159	callback when the event occurs (of course, only when the event model
148	is in control).	160	is in control).
149		161
150	Note that B<callbacks must not permanently change global variables>	162	Note that B<callbacks must not permanently change global variables>
151	potentially in use by the event loop (such as C<$_> or C<$[>) and that B<<	163	potentially in use by the event loop (such as C<$_> or C<$[>) and that B<<
152	callbacks must not C<die> >>. The former is good programming practise in	164	callbacks must not C<die> >>. The former is good programming practice in
153	Perl and the latter stems from the fact that exception handling differs	165	Perl and the latter stems from the fact that exception handling differs
154	widely between event loops.	166	widely between event loops.
155		167
156	To disable the watcher you have to destroy it (e.g. by setting the	168	To disable a watcher you have to destroy it (e.g. by setting the
157	variable you store it in to C<undef> or otherwise deleting all references	169	variable you store it in to C<undef> or otherwise deleting all references
158	to it).	170	to it).
159		171
160	All watchers are created by calling a method on the C<AnyEvent> class.	172	All watchers are created by calling a method on the C<AnyEvent> class.
161		173
162	Many watchers either are used with "recursion" (repeating timers for	174	Many watchers either are used with "recursion" (repeating timers for
163	example), or need to refer to their watcher object in other ways.	175	example), or need to refer to their watcher object in other ways.
164		176
165	An any way to achieve that is this pattern:	177	One way to achieve that is this pattern:
166		178
167	my $w; $w = AnyEvent->type (arg => value ..., cb => sub {	179	my $w; $w = AnyEvent->type (arg => value ..., cb => sub {
168	# you can use $w here, for example to undef it	180	# you can use $w here, for example to undef it
169	undef $w;	181	undef $w;
170	});	182	});
…		…
172	Note that C<my $w; $w => combination. This is necessary because in Perl,	184	Note that C<my $w; $w => combination. This is necessary because in Perl,
173	my variables are only visible after the statement in which they are	185	my variables are only visible after the statement in which they are
174	declared.	186	declared.
175		187
176	=head2 I/O WATCHERS	188	=head2 I/O WATCHERS
		189
		190	$w = AnyEvent->io (
		191	fh => <filehandle_or_fileno>,
		192	poll => <"r" or "w">,
		193	cb => <callback>,
		194	);
177		195
178	You can create an I/O watcher by calling the C<< AnyEvent->io >> method	196	You can create an I/O watcher by calling the C<< AnyEvent->io >> method
179	with the following mandatory key-value pairs as arguments:	197	with the following mandatory key-value pairs as arguments:
180		198
181	C<fh> is the Perl I<file handle> (or a naked file descriptor) to watch	199	C<fh> is the Perl I<file handle> (or a naked file descriptor) to watch
…		…
196		214
197	The I/O watcher might use the underlying file descriptor or a copy of it.	215	The I/O watcher might use the underlying file descriptor or a copy of it.
198	You must not close a file handle as long as any watcher is active on the	216	You must not close a file handle as long as any watcher is active on the
199	underlying file descriptor.	217	underlying file descriptor.
200		218
201	Some event loops issue spurious readyness notifications, so you should	219	Some event loops issue spurious readiness notifications, so you should
202	always use non-blocking calls when reading/writing from/to your file	220	always use non-blocking calls when reading/writing from/to your file
203	handles.	221	handles.
204		222
205	Example: wait for readability of STDIN, then read a line and disable the	223	Example: wait for readability of STDIN, then read a line and disable the
206	watcher.	224	watcher.
…		…
211	undef $w;	229	undef $w;
212	});	230	});
213		231
214	=head2 TIME WATCHERS	232	=head2 TIME WATCHERS
215		233
		234	$w = AnyEvent->timer (after => <seconds>, cb => <callback>);
		235
		236	$w = AnyEvent->timer (
		237	after => <fractional_seconds>,
		238	interval => <fractional_seconds>,
		239	cb => <callback>,
		240	);
		241
216	You can create a time watcher by calling the C<< AnyEvent->timer >>	242	You can create a time watcher by calling the C<< AnyEvent->timer >>
217	method with the following mandatory arguments:	243	method with the following mandatory arguments:
218		244
219	C<after> specifies after how many seconds (fractional values are	245	C<after> specifies after how many seconds (fractional values are
220	supported) the callback should be invoked. C<cb> is the callback to invoke	246	supported) the callback should be invoked. C<cb> is the callback to invoke
…		…
222		248
223	Although the callback might get passed parameters, their value and	249	Although the callback might get passed parameters, their value and
224	presence is undefined and you cannot rely on them. Portable AnyEvent	250	presence is undefined and you cannot rely on them. Portable AnyEvent
225	callbacks cannot use arguments passed to time watcher callbacks.	251	callbacks cannot use arguments passed to time watcher callbacks.
226		252
227	The callback will normally be invoked once only. If you specify another	253	The callback will normally be invoked only once. If you specify another
228	parameter, C<interval>, as a strictly positive number (> 0), then the	254	parameter, C<interval>, as a strictly positive number (> 0), then the
229	callback will be invoked regularly at that interval (in fractional	255	callback will be invoked regularly at that interval (in fractional
230	seconds) after the first invocation. If C<interval> is specified with a	256	seconds) after the first invocation. If C<interval> is specified with a
231	false value, then it is treated as if it were missing.	257	false value, then it is treated as if it were not specified at all.
232		258
233	The callback will be rescheduled before invoking the callback, but no	259	The callback will be rescheduled before invoking the callback, but no
234	attempt is done to avoid timer drift in most backends, so the interval is	260	attempt is made to avoid timer drift in most backends, so the interval is
235	only approximate.	261	only approximate.
236		262
237	Example: fire an event after 7.7 seconds.	263	Example: fire an event after 7.7 seconds.
238		264
239	my $w = AnyEvent->timer (after => 7.7, cb => sub {	265	my $w = AnyEvent->timer (after => 7.7, cb => sub {
…		…
257		283
258	While most event loops expect timers to specified in a relative way, they	284	While most event loops expect timers to specified in a relative way, they
259	use absolute time internally. This makes a difference when your clock	285	use absolute time internally. This makes a difference when your clock
260	"jumps", for example, when ntp decides to set your clock backwards from	286	"jumps", for example, when ntp decides to set your clock backwards from
261	the wrong date of 2014-01-01 to 2008-01-01, a watcher that is supposed to	287	the wrong date of 2014-01-01 to 2008-01-01, a watcher that is supposed to
262	fire "after" a second might actually take six years to finally fire.	288	fire "after a second" might actually take six years to finally fire.
263		289
264	AnyEvent cannot compensate for this. The only event loop that is conscious	290	AnyEvent cannot compensate for this. The only event loop that is conscious
265	about these issues is L<EV>, which offers both relative (ev_timer, based	291	of these issues is L<EV>, which offers both relative (ev_timer, based
266	on true relative time) and absolute (ev_periodic, based on wallclock time)	292	on true relative time) and absolute (ev_periodic, based on wallclock time)
267	timers.	293	timers.
268		294
269	AnyEvent always prefers relative timers, if available, matching the	295	AnyEvent always prefers relative timers, if available, matching the
270	AnyEvent API.	296	AnyEvent API.
…		…
292	I<In almost all cases (in all cases if you don't care), this is the	318	I<In almost all cases (in all cases if you don't care), this is the
293	function to call when you want to know the current time.>	319	function to call when you want to know the current time.>
294		320
295	This function is also often faster then C<< AnyEvent->time >>, and	321	This function is also often faster then C<< AnyEvent->time >>, and
296	thus the preferred method if you want some timestamp (for example,	322	thus the preferred method if you want some timestamp (for example,
297	L<AnyEvent::Handle> uses this to update it's activity timeouts).	323	L<AnyEvent::Handle> uses this to update its activity timeouts).
298		324
299	The rest of this section is only of relevance if you try to be very exact	325	The rest of this section is only of relevance if you try to be very exact
300	with your timing, you can skip it without bad conscience.	326	with your timing; you can skip it without a bad conscience.
301		327
302	For a practical example of when these times differ, consider L<Event::Lib>	328	For a practical example of when these times differ, consider L<Event::Lib>
303	and L<EV> and the following set-up:	329	and L<EV> and the following set-up:
304		330
305	The event loop is running and has just invoked one of your callback at	331	The event loop is running and has just invoked one of your callbacks at
306	time=500 (assume no other callbacks delay processing). In your callback,	332	time=500 (assume no other callbacks delay processing). In your callback,
307	you wait a second by executing C<sleep 1> (blocking the process for a	333	you wait a second by executing C<sleep 1> (blocking the process for a
308	second) and then (at time=501) you create a relative timer that fires	334	second) and then (at time=501) you create a relative timer that fires
309	after three seconds.	335	after three seconds.
310		336
…		…
330	difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into	356	difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into
331	account.	357	account.
332		358
333	=item AnyEvent->now_update	359	=item AnyEvent->now_update
334		360
335	Some event loops (such as L<EV> or L<AnyEvent::Impl::Perl>) cache	361	Some event loops (such as L<EV> or L<AnyEvent::Loop>) cache the current
336	the current time for each loop iteration (see the discussion of L<<	362	time for each loop iteration (see the discussion of L<< AnyEvent->now >>,
337	AnyEvent->now >>, above).	363	above).
338		364
339	When a callback runs for a long time (or when the process sleeps), then	365	When a callback runs for a long time (or when the process sleeps), then
340	this "current" time will differ substantially from the real time, which	366	this "current" time will differ substantially from the real time, which
341	might affect timers and time-outs.	367	might affect timers and time-outs.
342		368
343	When this is the case, you can call this method, which will update the	369	When this is the case, you can call this method, which will update the
344	event loop's idea of "current time".	370	event loop's idea of "current time".
345		371
		372	A typical example would be a script in a web server (e.g. C<mod_perl>) -
		373	when mod_perl executes the script, then the event loop will have the wrong
		374	idea about the "current time" (being potentially far in the past, when the
		375	script ran the last time). In that case you should arrange a call to C<<
		376	AnyEvent->now_update >> each time the web server process wakes up again
		377	(e.g. at the start of your script, or in a handler).
		378
346	Note that updating the time I<might> cause some events to be handled.	379	Note that updating the time I<might> cause some events to be handled.
347		380
348	=back	381	=back
349		382
350	=head2 SIGNAL WATCHERS	383	=head2 SIGNAL WATCHERS
		384
		385	$w = AnyEvent->signal (signal => <uppercase_signal_name>, cb => <callback>);
351		386
352	You can watch for signals using a signal watcher, C<signal> is the signal	387	You can watch for signals using a signal watcher, C<signal> is the signal
353	I<name> in uppercase and without any C<SIG> prefix, C<cb> is the Perl	388	I<name> in uppercase and without any C<SIG> prefix, C<cb> is the Perl
354	callback to be invoked whenever a signal occurs.	389	callback to be invoked whenever a signal occurs.
355		390
…		…
368		403
369	This watcher might use C<%SIG> (depending on the event loop used),	404	This watcher might use C<%SIG> (depending on the event loop used),
370	so programs overwriting those signals directly will likely not work	405	so programs overwriting those signals directly will likely not work
371	correctly.	406	correctly.
372		407
		408	Example: exit on SIGINT
		409
		410	my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });
		411
		412	=head3 Restart Behaviour
		413
		414	While restart behaviour is up to the event loop implementation, most will
		415	not restart syscalls (that includes L<Async::Interrupt> and AnyEvent's
		416	pure perl implementation).
		417
		418	=head3 Safe/Unsafe Signals
		419
		420	Perl signals can be either "safe" (synchronous to opcode handling) or
		421	"unsafe" (asynchronous) - the former might get delayed indefinitely, the
		422	latter might corrupt your memory.
		423
		424	AnyEvent signal handlers are, in addition, synchronous to the event loop,
		425	i.e. they will not interrupt your running perl program but will only be
		426	called as part of the normal event handling (just like timer, I/O etc.
		427	callbacks, too).
		428
		429	=head3 Signal Races, Delays and Workarounds
		430
373	Also note that many event loops (e.g. Glib, Tk, Qt, IO::Async) do not	431	Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support attaching
374	support attaching callbacks to signals, which is a pity, as you cannot do	432	callbacks to signals in a generic way, which is a pity, as you cannot
375	race-free signal handling in perl. AnyEvent will try to do it's best, but	433	do race-free signal handling in perl, requiring C libraries for
		434	this. AnyEvent will try to do its best, which means in some cases,
376	in some cases, signals will be delayed. The maximum time a signal might	435	signals will be delayed. The maximum time a signal might be delayed is
377	be delayed is specified in C<$AnyEvent::MAX_SIGNAL_LATENCY> (default: 10	436	specified in C<$AnyEvent::MAX_SIGNAL_LATENCY> (default: 10 seconds). This
378	seconds). This variable can be changed only before the first signal	437	variable can be changed only before the first signal watcher is created,
379	watcher is created, and should be left alone otherwise. Higher values	438	and should be left alone otherwise. This variable determines how often
		439	AnyEvent polls for signals (in case a wake-up was missed). Higher values
380	will cause fewer spurious wake-ups, which is better for power and CPU	440	will cause fewer spurious wake-ups, which is better for power and CPU
		441	saving.
		442
381	saving. All these problems can be avoided by installing the optional	443	All these problems can be avoided by installing the optional
382	L<Async::Interrupt> module.	444	L<Async::Interrupt> module, which works with most event loops. It will not
383		445	work with inherently broken event loops such as L<Event> or L<Event::Lib>
384	Example: exit on SIGINT	446	(and not with L<POE> currently, as POE does its own workaround with
385		447	one-second latency). For those, you just have to suffer the delays.
386	my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });
387		448
388	=head2 CHILD PROCESS WATCHERS	449	=head2 CHILD PROCESS WATCHERS
389		450
		451	$w = AnyEvent->child (pid => <process id>, cb => <callback>);
		452
390	You can also watch on a child process exit and catch its exit status.	453	You can also watch for a child process exit and catch its exit status.
391		454
392	The child process is specified by the C<pid> argument (if set to C<0>, it	455	The child process is specified by the C<pid> argument (on some backends,
393	watches for any child process exit). The watcher will triggered only when	456	using C<0> watches for any child process exit, on others this will
394	the child process has finished and an exit status is available, not on	457	croak). The watcher will be triggered only when the child process has
395	any trace events (stopped/continued).	458	finished and an exit status is available, not on any trace events
		459	(stopped/continued).
396		460
397	The callback will be called with the pid and exit status (as returned by	461	The callback will be called with the pid and exit status (as returned by
398	waitpid), so unlike other watcher types, you I<can> rely on child watcher	462	waitpid), so unlike other watcher types, you I<can> rely on child watcher
399	callback arguments.	463	callback arguments.
400		464
…		…
418	thing in an AnyEvent program, you I<have> to create at least one	482	thing in an AnyEvent program, you I<have> to create at least one
419	watcher before you C<fork> the child (alternatively, you can call	483	watcher before you C<fork> the child (alternatively, you can call
420	C<AnyEvent::detect>).	484	C<AnyEvent::detect>).
421		485
422	As most event loops do not support waiting for child events, they will be	486	As most event loops do not support waiting for child events, they will be
423	emulated by AnyEvent in most cases, in which the latency and race problems	487	emulated by AnyEvent in most cases, in which case the latency and race
424	mentioned in the description of signal watchers apply.	488	problems mentioned in the description of signal watchers apply.
425		489
426	Example: fork a process and wait for it	490	Example: fork a process and wait for it
427		491
428	my $done = AnyEvent->condvar;	492	my $done = AnyEvent->condvar;
429		493
…		…
441	# do something else, then wait for process exit	505	# do something else, then wait for process exit
442	$done->recv;	506	$done->recv;
443		507
444	=head2 IDLE WATCHERS	508	=head2 IDLE WATCHERS
445		509
446	Sometimes there is a need to do something, but it is not so important	510	$w = AnyEvent->idle (cb => <callback>);
447	to do it instantly, but only when there is nothing better to do. This
448	"nothing better to do" is usually defined to be "no other events need
449	attention by the event loop".
450		511
451	Idle watchers ideally get invoked when the event loop has nothing	512	This will repeatedly invoke the callback after the process becomes idle,
452	better to do, just before it would block the process to wait for new	513	until either the watcher is destroyed or new events have been detected.
453	events. Instead of blocking, the idle watcher is invoked.
454		514
455	Most event loops unfortunately do not really support idle watchers (only	515	Idle watchers are useful when there is a need to do something, but it
		516	is not so important (or wise) to do it instantly. The callback will be
		517	invoked only when there is "nothing better to do", which is usually
		518	defined as "all outstanding events have been handled and no new events
		519	have been detected". That means that idle watchers ideally get invoked
		520	when the event loop has just polled for new events but none have been
		521	detected. Instead of blocking to wait for more events, the idle watchers
		522	will be invoked.
		523
		524	Unfortunately, most event loops do not really support idle watchers (only
456	EV, Event and Glib do it in a usable fashion) - for the rest, AnyEvent	525	EV, Event and Glib do it in a usable fashion) - for the rest, AnyEvent
457	will simply call the callback "from time to time".	526	will simply call the callback "from time to time".
458		527
459	Example: read lines from STDIN, but only process them when the	528	Example: read lines from STDIN, but only process them when the
460	program is otherwise idle:	529	program is otherwise idle:
…		…
476	});	545	});
477	});	546	});
478		547
479	=head2 CONDITION VARIABLES	548	=head2 CONDITION VARIABLES
480		549
		550	$cv = AnyEvent->condvar;
		551
		552	$cv->send (<list>);
		553	my @res = $cv->recv;
		554
481	If you are familiar with some event loops you will know that all of them	555	If you are familiar with some event loops you will know that all of them
482	require you to run some blocking "loop", "run" or similar function that	556	require you to run some blocking "loop", "run" or similar function that
483	will actively watch for new events and call your callbacks.	557	will actively watch for new events and call your callbacks.
484		558
485	AnyEvent is slightly different: it expects somebody else to run the event	559	AnyEvent is slightly different: it expects somebody else to run the event
486	loop and will only block when necessary (usually when told by the user).	560	loop and will only block when necessary (usually when told by the user).
487		561
488	The instrument to do that is called a "condition variable", so called	562	The tool to do that is called a "condition variable", so called because
489	because they represent a condition that must become true.	563	they represent a condition that must become true.
490		564
491	Now is probably a good time to look at the examples further below.	565	Now is probably a good time to look at the examples further below.
492		566
493	Condition variables can be created by calling the C<< AnyEvent->condvar	567	Condition variables can be created by calling the C<< AnyEvent->condvar
494	>> method, usually without arguments. The only argument pair allowed is	568	>> method, usually without arguments. The only argument pair allowed is
…		…
499	After creation, the condition variable is "false" until it becomes "true"	573	After creation, the condition variable is "false" until it becomes "true"
500	by calling the C<send> method (or calling the condition variable as if it	574	by calling the C<send> method (or calling the condition variable as if it
501	were a callback, read about the caveats in the description for the C<<	575	were a callback, read about the caveats in the description for the C<<
502	->send >> method).	576	->send >> method).
503		577
504	Condition variables are similar to callbacks, except that you can	578	Since condition variables are the most complex part of the AnyEvent API, here are
505	optionally wait for them. They can also be called merge points - points	579	some different mental models of what they are - pick the ones you can connect to:
506	in time where multiple outstanding events have been processed. And yet	580
507	another way to call them is transactions - each condition variable can be	581	=over 4
508	used to represent a transaction, which finishes at some point and delivers	582
509	a result.	583	=item * Condition variables are like callbacks - you can call them (and pass them instead
		584	of callbacks). Unlike callbacks however, you can also wait for them to be called.
		585
		586	=item * Condition variables are signals - one side can emit or send them,
		587	the other side can wait for them, or install a handler that is called when
		588	the signal fires.
		589
		590	=item * Condition variables are like "Merge Points" - points in your program
		591	where you merge multiple independent results/control flows into one.
		592
		593	=item * Condition variables represent a transaction - functions that start
		594	some kind of transaction can return them, leaving the caller the choice
		595	between waiting in a blocking fashion, or setting a callback.
		596
		597	=item * Condition variables represent future values, or promises to deliver
		598	some result, long before the result is available.
		599
		600	=back
510		601
511	Condition variables are very useful to signal that something has finished,	602	Condition variables are very useful to signal that something has finished,
512	for example, if you write a module that does asynchronous http requests,	603	for example, if you write a module that does asynchronous http requests,
513	then a condition variable would be the ideal candidate to signal the	604	then a condition variable would be the ideal candidate to signal the
514	availability of results. The user can either act when the callback is	605	availability of results. The user can either act when the callback is
…		…
527		618
528	Condition variables are represented by hash refs in perl, and the keys	619	Condition variables are represented by hash refs in perl, and the keys
529	used by AnyEvent itself are all named C<_ae_XXX> to make subclassing	620	used by AnyEvent itself are all named C<_ae_XXX> to make subclassing
530	easy (it is often useful to build your own transaction class on top of	621	easy (it is often useful to build your own transaction class on top of
531	AnyEvent). To subclass, use C<AnyEvent::CondVar> as base class and call	622	AnyEvent). To subclass, use C<AnyEvent::CondVar> as base class and call
532	it's C<new> method in your own C<new> method.	623	its C<new> method in your own C<new> method.
533		624
534	There are two "sides" to a condition variable - the "producer side" which	625	There are two "sides" to a condition variable - the "producer side" which
535	eventually calls C<< -> send >>, and the "consumer side", which waits	626	eventually calls C<< -> send >>, and the "consumer side", which waits
536	for the send to occur.	627	for the send to occur.
537		628
538	Example: wait for a timer.	629	Example: wait for a timer.
539		630
540	# wait till the result is ready	631	# condition: "wait till the timer is fired"
541	my $result_ready = AnyEvent->condvar;	632	my $timer_fired = AnyEvent->condvar;
542		633
543	# do something such as adding a timer	634	# create the timer - we could wait for, say
544	# or socket watcher the calls $result_ready->send	635	# a handle becomign ready, or even an
545	# when the "result" is ready.	636	# AnyEvent::HTTP request to finish, but
546	# in this case, we simply use a timer:	637	# in this case, we simply use a timer:
547	my $w = AnyEvent->timer (	638	my $w = AnyEvent->timer (
548	after => 1,	639	after => 1,
549	cb => sub { $result_ready->send },	640	cb => sub { $timer_fired->send },
550	);	641	);
551		642
552	# this "blocks" (while handling events) till the callback	643	# this "blocks" (while handling events) till the callback
553	# calls -<send	644	# calls ->send
554	$result_ready->recv;	645	$timer_fired->recv;
555		646
556	Example: wait for a timer, but take advantage of the fact that condition	647	Example: wait for a timer, but take advantage of the fact that condition
557	variables are also callable directly.	648	variables are also callable directly.
558		649
559	my $done = AnyEvent->condvar;	650	my $done = AnyEvent->condvar;
…		…
602	they were a code reference). Calling them directly is the same as calling	693	they were a code reference). Calling them directly is the same as calling
603	C<send>.	694	C<send>.
604		695
605	=item $cv->croak ($error)	696	=item $cv->croak ($error)
606		697
607	Similar to send, but causes all call's to C<< ->recv >> to invoke	698	Similar to send, but causes all calls to C<< ->recv >> to invoke
608	C<Carp::croak> with the given error message/object/scalar.	699	C<Carp::croak> with the given error message/object/scalar.
609		700
610	This can be used to signal any errors to the condition variable	701	This can be used to signal any errors to the condition variable
611	user/consumer. Doing it this way instead of calling C<croak> directly	702	user/consumer. Doing it this way instead of calling C<croak> directly
612	delays the error detetcion, but has the overwhelmign advantage that it	703	delays the error detection, but has the overwhelming advantage that it
613	diagnoses the error at the place where the result is expected, and not	704	diagnoses the error at the place where the result is expected, and not
614	deep in some event clalback without connection to the actual code causing	705	deep in some event callback with no connection to the actual code causing
615	the problem.	706	the problem.
616		707
617	=item $cv->begin ([group callback])	708	=item $cv->begin ([group callback])
618		709
619	=item $cv->end	710	=item $cv->end
…		…
622	one. For example, a function that pings many hosts in parallel might want	713	one. For example, a function that pings many hosts in parallel might want
623	to use a condition variable for the whole process.	714	to use a condition variable for the whole process.
624		715
625	Every call to C<< ->begin >> will increment a counter, and every call to	716	Every call to C<< ->begin >> will increment a counter, and every call to
626	C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end	717	C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end
627	>>, the (last) callback passed to C<begin> will be executed. That callback	718	>>, the (last) callback passed to C<begin> will be executed, passing the
628	is I<supposed> to call C<< ->send >>, but that is not required. If no	719	condvar as first argument. That callback is I<supposed> to call C<< ->send
629	callback was set, C<send> will be called without any arguments.	720	>>, but that is not required. If no group callback was set, C<send> will
		721	be called without any arguments.
630		722
631	You can think of C<< $cv->send >> giving you an OR condition (one call	723	You can think of C<< $cv->send >> giving you an OR condition (one call
632	sends), while C<< $cv->begin >> and C<< $cv->end >> giving you an AND	724	sends), while C<< $cv->begin >> and C<< $cv->end >> giving you an AND
633	condition (all C<begin> calls must be C<end>'ed before the condvar sends).	725	condition (all C<begin> calls must be C<end>'ed before the condvar sends).
634		726
…		…
656	one call to C<begin>, so the condvar waits for all calls to C<end> before	748	one call to C<begin>, so the condvar waits for all calls to C<end> before
657	sending.	749	sending.
658		750
659	The ping example mentioned above is slightly more complicated, as the	751	The ping example mentioned above is slightly more complicated, as the
660	there are results to be passwd back, and the number of tasks that are	752	there are results to be passwd back, and the number of tasks that are
661	begung can potentially be zero:	753	begun can potentially be zero:
662		754
663	my $cv = AnyEvent->condvar;	755	my $cv = AnyEvent->condvar;
664		756
665	my %result;	757	my %result;
666	$cv->begin (sub { $cv->send (\%result) });	758	$cv->begin (sub { shift->send (\%result) });
667		759
668	for my $host (@list_of_hosts) {	760	for my $host (@list_of_hosts) {
669	$cv->begin;	761	$cv->begin;
670	ping_host_then_call_callback $host, sub {	762	ping_host_then_call_callback $host, sub {
671	$result{$host} = ...;	763	$result{$host} = ...;
…		…
687	to be called once the counter reaches C<0>, and second, it ensures that	779	to be called once the counter reaches C<0>, and second, it ensures that
688	C<send> is called even when C<no> hosts are being pinged (the loop	780	C<send> is called even when C<no> hosts are being pinged (the loop
689	doesn't execute once).	781	doesn't execute once).
690		782
691	This is the general pattern when you "fan out" into multiple (but	783	This is the general pattern when you "fan out" into multiple (but
692	potentially none) subrequests: use an outer C<begin>/C<end> pair to set	784	potentially zero) subrequests: use an outer C<begin>/C<end> pair to set
693	the callback and ensure C<end> is called at least once, and then, for each	785	the callback and ensure C<end> is called at least once, and then, for each
694	subrequest you start, call C<begin> and for each subrequest you finish,	786	subrequest you start, call C<begin> and for each subrequest you finish,
695	call C<end>.	787	call C<end>.
696		788
697	=back	789	=back
…		…
704	=over 4	796	=over 4
705		797
706	=item $cv->recv	798	=item $cv->recv
707		799
708	Wait (blocking if necessary) until the C<< ->send >> or C<< ->croak	800	Wait (blocking if necessary) until the C<< ->send >> or C<< ->croak
709	>> methods have been called on c<$cv>, while servicing other watchers	801	>> methods have been called on C<$cv>, while servicing other watchers
710	normally.	802	normally.
711		803
712	You can only wait once on a condition - additional calls are valid but	804	You can only wait once on a condition - additional calls are valid but
713	will return immediately.	805	will return immediately.
714		806
…		…
731	caller decide whether the call will block or not (for example, by coupling	823	caller decide whether the call will block or not (for example, by coupling
732	condition variables with some kind of request results and supporting	824	condition variables with some kind of request results and supporting
733	callbacks so the caller knows that getting the result will not block,	825	callbacks so the caller knows that getting the result will not block,
734	while still supporting blocking waits if the caller so desires).	826	while still supporting blocking waits if the caller so desires).
735		827
736	You can ensure that C<< -recv >> never blocks by setting a callback and	828	You can ensure that C<< ->recv >> never blocks by setting a callback and
737	only calling C<< ->recv >> from within that callback (or at a later	829	only calling C<< ->recv >> from within that callback (or at a later
738	time). This will work even when the event loop does not support blocking	830	time). This will work even when the event loop does not support blocking
739	waits otherwise.	831	waits otherwise.
740		832
741	=item $bool = $cv->ready	833	=item $bool = $cv->ready
…		…
747		839
748	This is a mutator function that returns the callback set and optionally	840	This is a mutator function that returns the callback set and optionally
749	replaces it before doing so.	841	replaces it before doing so.
750		842
751	The callback will be called when the condition becomes "true", i.e. when	843	The callback will be called when the condition becomes "true", i.e. when
752	C<send> or C<croak> are called, with the only argument being the condition	844	C<send> or C<croak> are called, with the only argument being the
753	variable itself. Calling C<recv> inside the callback or at any later time	845	condition variable itself. If the condition is already true, the
754	is guaranteed not to block.	846	callback is called immediately when it is set. Calling C<recv> inside
		847	the callback or at any later time is guaranteed not to block.
755		848
756	=back	849	=back
757		850
758	=head1 SUPPORTED EVENT LOOPS/BACKENDS	851	=head1 SUPPORTED EVENT LOOPS/BACKENDS
759		852
…		…
762	=over 4	855	=over 4
763		856
764	=item Backends that are autoprobed when no other event loop can be found.	857	=item Backends that are autoprobed when no other event loop can be found.
765		858
766	EV is the preferred backend when no other event loop seems to be in	859	EV is the preferred backend when no other event loop seems to be in
767	use. If EV is not installed, then AnyEvent will try Event, and, failing	860	use. If EV is not installed, then AnyEvent will fall back to its own
768	that, will fall back to its own pure-perl implementation, which is	861	pure-perl implementation, which is available everywhere as it comes with
769	available everywhere as it comes with AnyEvent itself.	862	AnyEvent itself.
770		863
771	AnyEvent::Impl::EV based on EV (interface to libev, best choice).	864	AnyEvent::Impl::EV based on EV (interface to libev, best choice).
772	AnyEvent::Impl::Event based on Event, very stable, few glitches.
773	AnyEvent::Impl::Perl pure-perl implementation, fast and portable.	865	AnyEvent::Impl::Perl pure-perl AnyEvent::Loop, fast and portable.
774		866
775	=item Backends that are transparently being picked up when they are used.	867	=item Backends that are transparently being picked up when they are used.
776		868
777	These will be used when they are currently loaded when the first watcher	869	These will be used if they are already loaded when the first watcher
778	is created, in which case it is assumed that the application is using	870	is created, in which case it is assumed that the application is using
779	them. This means that AnyEvent will automatically pick the right backend	871	them. This means that AnyEvent will automatically pick the right backend
780	when the main program loads an event module before anything starts to	872	when the main program loads an event module before anything starts to
781	create watchers. Nothing special needs to be done by the main program.	873	create watchers. Nothing special needs to be done by the main program.
782		874
		875	AnyEvent::Impl::Event based on Event, very stable, few glitches.
783	AnyEvent::Impl::Glib based on Glib, slow but very stable.	876	AnyEvent::Impl::Glib based on Glib, slow but very stable.
784	AnyEvent::Impl::Tk based on Tk, very broken.	877	AnyEvent::Impl::Tk based on Tk, very broken.
785	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.	878	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
786	AnyEvent::Impl::POE based on POE, very slow, some limitations.	879	AnyEvent::Impl::POE based on POE, very slow, some limitations.
		880	AnyEvent::Impl::Irssi used when running within irssi.
		881	AnyEvent::Impl::IOAsync based on IO::Async.
		882	AnyEvent::Impl::Cocoa based on Cocoa::EventLoop.
		883	AnyEvent::Impl::FLTK2 based on FLTK (fltk 2 binding).
787		884
788	=item Backends with special needs.	885	=item Backends with special needs.
789		886
790	Qt requires the Qt::Application to be instantiated first, but will	887	Qt requires the Qt::Application to be instantiated first, but will
791	otherwise be picked up automatically. As long as the main program	888	otherwise be picked up automatically. As long as the main program
792	instantiates the application before any AnyEvent watchers are created,	889	instantiates the application before any AnyEvent watchers are created,
793	everything should just work.	890	everything should just work.
794		891
795	AnyEvent::Impl::Qt based on Qt.	892	AnyEvent::Impl::Qt based on Qt.
796		893
797	Support for IO::Async can only be partial, as it is too broken and
798	architecturally limited to even support the AnyEvent API. It also
799	is the only event loop that needs the loop to be set explicitly, so
800	it can only be used by a main program knowing about AnyEvent. See
801	L<AnyEvent::Impl::Async> for the gory details.
802
803	AnyEvent::Impl::IOAsync based on IO::Async, cannot be autoprobed.
804
805	=item Event loops that are indirectly supported via other backends.	894	=item Event loops that are indirectly supported via other backends.
806		895
807	Some event loops can be supported via other modules:	896	Some event loops can be supported via other modules:
808		897
809	There is no direct support for WxWidgets (L<Wx>) or L<Prima>.	898	There is no direct support for WxWidgets (L<Wx>) or L<Prima>.
…		…
834	Contains C<undef> until the first watcher is being created, before the	923	Contains C<undef> until the first watcher is being created, before the
835	backend has been autodetected.	924	backend has been autodetected.
836		925
837	Afterwards it contains the event model that is being used, which is the	926	Afterwards it contains the event model that is being used, which is the
838	name of the Perl class implementing the model. This class is usually one	927	name of the Perl class implementing the model. This class is usually one
839	of the C<AnyEvent::Impl:xxx> modules, but can be any other class in the	928	of the C<AnyEvent::Impl::xxx> modules, but can be any other class in the
840	case AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode> it	929	case AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode> it
841	will be C<urxvt::anyevent>).	930	will be C<urxvt::anyevent>).
842		931
843	=item AnyEvent::detect	932	=item AnyEvent::detect
844		933
845	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model	934	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model
846	if necessary. You should only call this function right before you would	935	if necessary. You should only call this function right before you would
847	have created an AnyEvent watcher anyway, that is, as late as possible at	936	have created an AnyEvent watcher anyway, that is, as late as possible at
848	runtime, and not e.g. while initialising of your module.	937	runtime, and not e.g. during initialisation of your module.
		938
		939	The effect of calling this function is as if a watcher had been created
		940	(specifically, actions that happen "when the first watcher is created"
		941	happen when calling detetc as well).
849		942
850	If you need to do some initialisation before AnyEvent watchers are	943	If you need to do some initialisation before AnyEvent watchers are
851	created, use C<post_detect>.	944	created, use C<post_detect>.
852		945
853	=item $guard = AnyEvent::post_detect { BLOCK }	946	=item $guard = AnyEvent::post_detect { BLOCK }
854		947
855	Arranges for the code block to be executed as soon as the event model is	948	Arranges for the code block to be executed as soon as the event model is
856	autodetected (or immediately if this has already happened).	949	autodetected (or immediately if that has already happened).
857		950
858	The block will be executed I<after> the actual backend has been detected	951	The block will be executed I<after> the actual backend has been detected
859	(C<$AnyEvent::MODEL> is set), but I<before> any watchers have been	952	(C<$AnyEvent::MODEL> is set), but I<before> any watchers have been
860	created, so it is possible to e.g. patch C<@AnyEvent::ISA> or do	953	created, so it is possible to e.g. patch C<@AnyEvent::ISA> or do
861	other initialisations - see the sources of L<AnyEvent::Strict> or	954	other initialisations - see the sources of L<AnyEvent::Strict> or
…		…
865	event module detection too early, for example, L<AnyEvent::AIO> creates	958	event module detection too early, for example, L<AnyEvent::AIO> creates
866	and installs the global L<IO::AIO> watcher in a C<post_detect> block to	959	and installs the global L<IO::AIO> watcher in a C<post_detect> block to
867	avoid autodetecting the event module at load time.	960	avoid autodetecting the event module at load time.
868		961
869	If called in scalar or list context, then it creates and returns an object	962	If called in scalar or list context, then it creates and returns an object
870	that automatically removes the callback again when it is destroyed. See	963	that automatically removes the callback again when it is destroyed (or
		964	C<undef> when the hook was immediately executed). See L<AnyEvent::AIO> for
871	L<Coro::BDB> for a case where this is useful.	965	a case where this is useful.
		966
		967	Example: Create a watcher for the IO::AIO module and store it in
		968	C<$WATCHER>, but do so only do so after the event loop is initialised.
		969
		970	our WATCHER;
		971
		972	my $guard = AnyEvent::post_detect {
		973	$WATCHER = AnyEvent->io (fh => IO::AIO::poll_fileno, poll => 'r', cb => \&IO::AIO::poll_cb);
		974	};
		975
		976	# the ||= is important in case post_detect immediately runs the block,
		977	# as to not clobber the newly-created watcher. assigning both watcher and
		978	# post_detect guard to the same variable has the advantage of users being
		979	# able to just C<undef $WATCHER> if the watcher causes them grief.
		980
		981	$WATCHER ||= $guard;
872		982
873	=item @AnyEvent::post_detect	983	=item @AnyEvent::post_detect
874		984
875	If there are any code references in this array (you can C<push> to it	985	If there are any code references in this array (you can C<push> to it
876	before or after loading AnyEvent), then they will called directly after	986	before or after loading AnyEvent), then they will be called directly
877	the event loop has been chosen.	987	after the event loop has been chosen.
878		988
879	You should check C<$AnyEvent::MODEL> before adding to this array, though:	989	You should check C<$AnyEvent::MODEL> before adding to this array, though:
880	if it is defined then the event loop has already been detected, and the	990	if it is defined then the event loop has already been detected, and the
881	array will be ignored.	991	array will be ignored.
882		992
883	Best use C<AnyEvent::post_detect { BLOCK }> when your application allows	993	Best use C<AnyEvent::post_detect { BLOCK }> when your application allows
884	it,as it takes care of these details.	994	it, as it takes care of these details.
885		995
886	This variable is mainly useful for modules that can do something useful	996	This variable is mainly useful for modules that can do something useful
887	when AnyEvent is used and thus want to know when it is initialised, but do	997	when AnyEvent is used and thus want to know when it is initialised, but do
888	not need to even load it by default. This array provides the means to hook	998	not need to even load it by default. This array provides the means to hook
889	into AnyEvent passively, without loading it.	999	into AnyEvent passively, without loading it.
890		1000
		1001	Example: To load Coro::AnyEvent whenever Coro and AnyEvent are used
		1002	together, you could put this into Coro (this is the actual code used by
		1003	Coro to accomplish this):
		1004
		1005	if (defined $AnyEvent::MODEL) {
		1006	# AnyEvent already initialised, so load Coro::AnyEvent
		1007	require Coro::AnyEvent;
		1008	} else {
		1009	# AnyEvent not yet initialised, so make sure to load Coro::AnyEvent
		1010	# as soon as it is
		1011	push @AnyEvent::post_detect, sub { require Coro::AnyEvent };
		1012	}
		1013
		1014	=item AnyEvent::postpone { BLOCK }
		1015
		1016	Arranges for the block to be executed as soon as possible, but not before
		1017	the call itself returns. In practise, the block will be executed just
		1018	before the event loop polls for new events, or shortly afterwards.
		1019
		1020	This function never returns anything (to make the C<return postpone { ...
		1021	}> idiom more useful.
		1022
		1023	To understand the usefulness of this function, consider a function that
		1024	asynchronously does something for you and returns some transaction
		1025	object or guard to let you cancel the operation. For example,
		1026	C<AnyEvent::Socket::tcp_connect>:
		1027
		1028	# start a conenction attempt unless one is active
		1029	$self->{connect_guard} ||= AnyEvent::Socket::tcp_connect "www.example.net", 80, sub {
		1030	delete $self->{connect_guard};
		1031	...
		1032	};
		1033
		1034	Imagine that this function could instantly call the callback, for
		1035	example, because it detects an obvious error such as a negative port
		1036	number. Invoking the callback before the function returns causes problems
		1037	however: the callback will be called and will try to delete the guard
		1038	object. But since the function hasn't returned yet, there is nothing to
		1039	delete. When the function eventually returns it will assign the guard
		1040	object to C<< $self->{connect_guard} >>, where it will likely never be
		1041	deleted, so the program thinks it is still trying to connect.
		1042
		1043	This is where C<AnyEvent::postpone> should be used. Instead of calling the
		1044	callback directly on error:
		1045
		1046	$cb->(undef), return # signal error to callback, BAD!
		1047	if $some_error_condition;
		1048
		1049	It should use C<postpone>:
		1050
		1051	AnyEvent::postpone { $cb->(undef) }, return # signal error to callback, later
		1052	if $some_error_condition;
		1053
		1054	=item AnyEvent::log $level, $msg[, @args]
		1055
		1056	Log the given C<$msg> at the given C<$level>.
		1057
		1058	Loads AnyEvent::Log on first use and calls C<AnyEvent::Log::log> -
		1059	consequently, look at the L<AnyEvent::Log> documentation for details.
		1060
		1061	If you want to sprinkle loads of logging calls around your code, consider
		1062	creating a logger callback with the C<AnyEvent::Log::logger> function.
		1063
891	=back	1064	=back
892		1065
893	=head1 WHAT TO DO IN A MODULE	1066	=head1 WHAT TO DO IN A MODULE
894		1067
895	As a module author, you should C<use AnyEvent> and call AnyEvent methods	1068	As a module author, you should C<use AnyEvent> and call AnyEvent methods
…		…
905	because it will stall the whole program, and the whole point of using	1078	because it will stall the whole program, and the whole point of using
906	events is to stay interactive.	1079	events is to stay interactive.
907		1080
908	It is fine, however, to call C<< ->recv >> when the user of your module	1081	It is fine, however, to call C<< ->recv >> when the user of your module
909	requests it (i.e. if you create a http request object ad have a method	1082	requests it (i.e. if you create a http request object ad have a method
910	called C<results> that returns the results, it should call C<< ->recv >>	1083	called C<results> that returns the results, it may call C<< ->recv >>
911	freely, as the user of your module knows what she is doing. always).	1084	freely, as the user of your module knows what she is doing. Always).
912		1085
913	=head1 WHAT TO DO IN THE MAIN PROGRAM	1086	=head1 WHAT TO DO IN THE MAIN PROGRAM
914		1087
915	There will always be a single main program - the only place that should	1088	There will always be a single main program - the only place that should
916	dictate which event model to use.	1089	dictate which event model to use.
917		1090
918	If it doesn't care, it can just "use AnyEvent" and use it itself, or not	1091	If the program is not event-based, it need not do anything special, even
919	do anything special (it does not need to be event-based) and let AnyEvent	1092	when it depends on a module that uses an AnyEvent. If the program itself
920	decide which implementation to chose if some module relies on it.	1093	uses AnyEvent, but does not care which event loop is used, all it needs
		1094	to do is C<use AnyEvent>. In either case, AnyEvent will choose the best
		1095	available loop implementation.
921		1096
922	If the main program relies on a specific event model - for example, in	1097	If the main program relies on a specific event model - for example, in
923	Gtk2 programs you have to rely on the Glib module - you should load the	1098	Gtk2 programs you have to rely on the Glib module - you should load the
924	event module before loading AnyEvent or any module that uses it: generally	1099	event module before loading AnyEvent or any module that uses it: generally
925	speaking, you should load it as early as possible. The reason is that	1100	speaking, you should load it as early as possible. The reason is that
926	modules might create watchers when they are loaded, and AnyEvent will	1101	modules might create watchers when they are loaded, and AnyEvent will
927	decide on the event model to use as soon as it creates watchers, and it	1102	decide on the event model to use as soon as it creates watchers, and it
928	might chose the wrong one unless you load the correct one yourself.	1103	might choose the wrong one unless you load the correct one yourself.
929		1104
930	You can chose to use a pure-perl implementation by loading the	1105	You can chose to use a pure-perl implementation by loading the
931	C<AnyEvent::Impl::Perl> module, which gives you similar behaviour	1106	C<AnyEvent::Loop> module, which gives you similar behaviour
932	everywhere, but letting AnyEvent chose the model is generally better.	1107	everywhere, but letting AnyEvent chose the model is generally better.
933		1108
934	=head2 MAINLOOP EMULATION	1109	=head2 MAINLOOP EMULATION
935		1110
936	Sometimes (often for short test scripts, or even standalone programs who	1111	Sometimes (often for short test scripts, or even standalone programs who
…		…
949		1124
950		1125
951	=head1 OTHER MODULES	1126	=head1 OTHER MODULES
952		1127
953	The following is a non-exhaustive list of additional modules that use	1128	The following is a non-exhaustive list of additional modules that use
954	AnyEvent as a client and can therefore be mixed easily with other AnyEvent	1129	AnyEvent as a client and can therefore be mixed easily with other
955	modules and other event loops in the same program. Some of the modules	1130	AnyEvent modules and other event loops in the same program. Some of the
956	come with AnyEvent, most are available via CPAN.	1131	modules come as part of AnyEvent, the others are available via CPAN (see
		1132	L<http://search.cpan.org/search?m=module&q=anyevent%3A%3A*> for
		1133	a longer non-exhaustive list), and the list is heavily biased towards
		1134	modules of the AnyEvent author himself :)
957		1135
958	=over 4	1136	=over 4
959		1137
960	=item L<AnyEvent::Util>	1138	=item L<AnyEvent::Util>
961		1139
962	Contains various utility functions that replace often-used but blocking	1140	Contains various utility functions that replace often-used blocking
963	functions such as C<inet_aton> by event-/callback-based versions.	1141	functions such as C<inet_aton> with event/callback-based versions.
964		1142
965	=item L<AnyEvent::Socket>	1143	=item L<AnyEvent::Socket>
966		1144
967	Provides various utility functions for (internet protocol) sockets,	1145	Provides various utility functions for (internet protocol) sockets,
968	addresses and name resolution. Also functions to create non-blocking tcp	1146	addresses and name resolution. Also functions to create non-blocking tcp
…		…
970		1148
971	=item L<AnyEvent::Handle>	1149	=item L<AnyEvent::Handle>
972		1150
973	Provide read and write buffers, manages watchers for reads and writes,	1151	Provide read and write buffers, manages watchers for reads and writes,
974	supports raw and formatted I/O, I/O queued and fully transparent and	1152	supports raw and formatted I/O, I/O queued and fully transparent and
975	non-blocking SSL/TLS (via L<AnyEvent::TLS>.	1153	non-blocking SSL/TLS (via L<AnyEvent::TLS>).
976		1154
977	=item L<AnyEvent::DNS>	1155	=item L<AnyEvent::DNS>
978		1156
979	Provides rich asynchronous DNS resolver capabilities.	1157	Provides rich asynchronous DNS resolver capabilities.
980		1158
		1159	=item L<AnyEvent::HTTP>, L<AnyEvent::IRC>, L<AnyEvent::XMPP>, L<AnyEvent::GPSD>, L<AnyEvent::IGS>, L<AnyEvent::FCP>
		1160
		1161	Implement event-based interfaces to the protocols of the same name (for
		1162	the curious, IGS is the International Go Server and FCP is the Freenet
		1163	Client Protocol).
		1164
		1165	=item L<AnyEvent::Handle::UDP>
		1166
		1167	Here be danger!
		1168
		1169	As Pauli would put it, "Not only is it not right, it's not even wrong!" -
		1170	there are so many things wrong with AnyEvent::Handle::UDP, most notably
		1171	its use of a stream-based API with a protocol that isn't streamable, that
		1172	the only way to improve it is to delete it.
		1173
		1174	It features data corruption (but typically only under load) and general
		1175	confusion. On top, the author is not only clueless about UDP but also
		1176	fact-resistant - some gems of his understanding: "connect doesn't work
		1177	with UDP", "UDP packets are not IP packets", "UDP only has datagrams, not
		1178	packets", "I don't need to implement proper error checking as UDP doesn't
		1179	support error checking" and so on - he doesn't even understand what's
		1180	wrong with his module when it is explained to him.
		1181
981	=item L<AnyEvent::HTTP>	1182	=item L<AnyEvent::DBI>
982		1183
983	A simple-to-use HTTP library that is capable of making a lot of concurrent	1184	Executes L<DBI> requests asynchronously in a proxy process for you,
984	HTTP requests.	1185	notifying you in an event-based way when the operation is finished.
		1186
		1187	=item L<AnyEvent::AIO>
		1188
		1189	Truly asynchronous (as opposed to non-blocking) I/O, should be in the
		1190	toolbox of every event programmer. AnyEvent::AIO transparently fuses
		1191	L<IO::AIO> and AnyEvent together, giving AnyEvent access to event-based
		1192	file I/O, and much more.
985		1193
986	=item L<AnyEvent::HTTPD>	1194	=item L<AnyEvent::HTTPD>
987		1195
988	Provides a simple web application server framework.	1196	A simple embedded webserver.
989		1197
990	=item L<AnyEvent::FastPing>	1198	=item L<AnyEvent::FastPing>
991		1199
992	The fastest ping in the west.	1200	The fastest ping in the west.
993
994	=item L<AnyEvent::DBI>
995
996	Executes L<DBI> requests asynchronously in a proxy process.
997
998	=item L<AnyEvent::AIO>
999
1000	Truly asynchronous I/O, should be in the toolbox of every event
1001	programmer. AnyEvent::AIO transparently fuses L<IO::AIO> and AnyEvent
1002	together.
1003
1004	=item L<AnyEvent::BDB>
1005
1006	Truly asynchronous Berkeley DB access. AnyEvent::BDB transparently fuses
1007	L<BDB> and AnyEvent together.
1008
1009	=item L<AnyEvent::GPSD>
1010
1011	A non-blocking interface to gpsd, a daemon delivering GPS information.
1012
1013	=item L<AnyEvent::IRC>
1014
1015	AnyEvent based IRC client module family (replacing the older Net::IRC3).
1016
1017	=item L<AnyEvent::XMPP>
1018
1019	AnyEvent based XMPP (Jabber protocol) module family (replacing the older
1020	Net::XMPP2>.
1021
1022	=item L<AnyEvent::IGS>
1023
1024	A non-blocking interface to the Internet Go Server protocol (used by
1025	L<App::IGS>).
1026
1027	=item L<Net::FCP>
1028
1029	AnyEvent-based implementation of the Freenet Client Protocol, birthplace
1030	of AnyEvent.
1031
1032	=item L<Event::ExecFlow>
1033
1034	High level API for event-based execution flow control.
1035		1201
1036	=item L<Coro>	1202	=item L<Coro>
1037		1203
1038	Has special support for AnyEvent via L<Coro::AnyEvent>.	1204	Has special support for AnyEvent via L<Coro::AnyEvent>.
1039		1205
…		…
1043		1209
1044	package AnyEvent;	1210	package AnyEvent;
1045		1211
1046	# basically a tuned-down version of common::sense	1212	# basically a tuned-down version of common::sense
1047	sub common_sense {	1213	sub common_sense {
1048	# no warnings	1214	# from common:.sense 3.4
1049	${^WARNING_BITS} ^= ${^WARNING_BITS};	1215	${^WARNING_BITS} ^= ${^WARNING_BITS} ^ "\x3c\x3f\x33\x00\x0f\xf0\x0f\xc0\xf0\xfc\x33\x00";
1050	# use strict vars subs	1216	# use strict vars subs - NO UTF-8, as Util.pm doesn't like this atm. (uts46data.pl)
1051	$^H |= 0x00000600;	1217	$^H |= 0x00000600;
1052	}	1218	}
1053		1219
1054	BEGIN { AnyEvent::common_sense }	1220	BEGIN { AnyEvent::common_sense }
1055		1221
1056	use Carp ();	1222	use Carp ();
1057		1223
1058	our $VERSION = 4.85;	1224	our $VERSION = '6.01';
1059	our $MODEL;	1225	our $MODEL;
1060		1226
1061	our $AUTOLOAD;
1062	our @ISA;	1227	our @ISA;
1063		1228
1064	our @REGISTRY;	1229	our @REGISTRY;
1065		1230
1066	our $WIN32;
1067
1068	our $VERBOSE;	1231	our $VERBOSE;
1069		1232
1070	BEGIN {	1233	BEGIN {
1071	eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }";	1234	require "AnyEvent/constants.pl";
		1235
1072	eval "sub TAINT(){ " . (${^TAINT}*1) . " }";	1236	eval "sub TAINT (){" . (${^TAINT}*1) . "}";
1073		1237
1074	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}	1238	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}
1075	if ${^TAINT};	1239	if ${^TAINT};
1076		1240
		1241	$ENV{"PERL_ANYEVENT_$_"} = $ENV{"AE_$_"}
		1242	for grep s/^AE_// && !exists $ENV{"PERL_ANYEVENT_$_"}, keys %ENV;
		1243
		1244	@ENV{grep /^PERL_ANYEVENT_/, keys %ENV} = ()
		1245	if ${^TAINT};
		1246
1077	$VERBOSE = $ENV{PERL_ANYEVENT_VERBOSE}*1;	1247	$VERBOSE = $ENV{PERL_ANYEVENT_VERBOSE}*1;
1078
1079	}	1248	}
1080		1249
1081	our $MAX_SIGNAL_LATENCY = 10;	1250	our $MAX_SIGNAL_LATENCY = 10;
1082		1251
1083	our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred	1252	our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred
…		…
1087	$PROTOCOL{$_} = ++$idx	1256	$PROTOCOL{$_} = ++$idx
1088	for reverse split /\s*,\s*/,	1257	for reverse split /\s*,\s*/,
1089	$ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";	1258	$ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";
1090	}	1259	}
1091		1260
		1261	our @post_detect;
		1262
		1263	sub post_detect(&) {
		1264	my ($cb) = @_;
		1265
		1266	push @post_detect, $cb;
		1267
		1268	defined wantarray
		1269	? bless \$cb, "AnyEvent::Util::postdetect"
		1270	: ()
		1271	}
		1272
		1273	sub AnyEvent::Util::postdetect::DESTROY {
		1274	@post_detect = grep $_ != ${$_[0]}, @post_detect;
		1275	}
		1276
		1277	our $POSTPONE_W;
		1278	our @POSTPONE;
		1279
		1280	sub _postpone_exec {
		1281	undef $POSTPONE_W;
		1282
		1283	&{ shift @POSTPONE }
		1284	while @POSTPONE;
		1285	}
		1286
		1287	sub postpone(&) {
		1288	push @POSTPONE, shift;
		1289
		1290	$POSTPONE_W ||= AE::timer (0, 0, \&_postpone_exec);
		1291
		1292	()
		1293	}
		1294
		1295	sub log($$;@) {
		1296	require AnyEvent::Log;
		1297	# AnyEvent::Log overwrites this function
		1298	goto &log;
		1299	}
		1300
1092	my @models = (	1301	our @models = (
1093	[EV:: => AnyEvent::Impl::EV::],	1302	[EV:: => AnyEvent::Impl::EV:: , 1],
1094	[Event:: => AnyEvent::Impl::Event::],	1303	[AnyEvent::Loop:: => AnyEvent::Impl::Perl:: , 1],
1095	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::],
1096	# everything below here will not be autoprobed	1304	# everything below here will not (normally) be autoprobed
1097	# as the pureperl backend should work everywhere	1305	# as the pure perl backend should work everywhere
1098	# and is usually faster	1306	# and is usually faster
		1307	[Event:: => AnyEvent::Impl::Event::, 1],
1099	[Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers	1308	[Glib:: => AnyEvent::Impl::Glib:: , 1], # becomes extremely slow with many watchers
1100	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy	1309	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
		1310	[Irssi:: => AnyEvent::Impl::Irssi::], # Irssi has a bogus "Event" package
1101	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles	1311	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
1102	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program	1312	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program
1103	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza	1313	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
1104	[Wx:: => AnyEvent::Impl::POE::],	1314	[Wx:: => AnyEvent::Impl::POE::],
1105	[Prima:: => AnyEvent::Impl::POE::],	1315	[Prima:: => AnyEvent::Impl::POE::],
1106	# IO::Async is just too broken - we would need workarounds for its	1316	[IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # a bitch to autodetect
1107	# byzantine signal and broken child handling, among others.	1317	[Cocoa::EventLoop:: => AnyEvent::Impl::Cocoa::],
1108	# IO::Async is rather hard to detect, as it doesn't have any	1318	[FLTK:: => AnyEvent::Impl::FLTK2::],
1109	# obvious default class.
1110	# [IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program
1111	# [IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program
1112	# [IO::Async::Notifier:: => AnyEvent::Impl::IOAsync::], # requires special main program
1113	);	1319	);
1114		1320
1115	our %method = map +($_ => 1),	1321	our @isa_hook;
		1322
		1323	sub _isa_set {
		1324	my @pkg = ("AnyEvent", (map $_->[0], grep defined, @isa_hook), $MODEL);
		1325
		1326	@{"$pkg[$_-1]::ISA"} = $pkg[$_]
		1327	for 1 .. $#pkg;
		1328
		1329	grep $_ && $_->[1], @isa_hook
		1330	and AE::_reset ();
		1331	}
		1332
		1333	# used for hooking AnyEvent::Strict and AnyEvent::Debug::Wrap into the class hierarchy
		1334	sub _isa_hook($$;$) {
		1335	my ($i, $pkg, $reset_ae) = @_;
		1336
		1337	$isa_hook[$i] = $pkg ? [$pkg, $reset_ae] : undef;
		1338
		1339	_isa_set;
		1340	}
		1341
		1342	# all autoloaded methods reserve the complete glob, not just the method slot.
		1343	# due to bugs in perls method cache implementation.
1116	qw(io timer time now now_update signal child idle condvar one_event DESTROY);	1344	our @methods = qw(io timer time now now_update signal child idle condvar);
1117		1345
1118	our @post_detect;
1119
1120	sub post_detect(&) {	1346	sub detect() {
1121	my ($cb) = @_;	1347	return $MODEL if $MODEL; # some programs keep references to detect
1122		1348
1123	if ($MODEL) {	1349	local $!; # for good measure
1124	$cb->();	1350	local $SIG{__DIE__}; # we use eval
1125		1351
1126	1	1352	# free some memory
		1353	*detect = sub () { $MODEL };
		1354	# undef &func doesn't correctly update the method cache. grmbl.
		1355	# so we delete the whole glob. grmbl.
		1356	# otoh, perl doesn't let me undef an active usb, but it lets me free
		1357	# a glob with an active sub. hrm. i hope it works, but perl is
		1358	# usually buggy in this department. sigh.
		1359	delete @{"AnyEvent::"}{@methods};
		1360	undef @methods;
		1361
		1362	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z0-9:]+)$/) {
		1363	my $model = $1;
		1364	$model = "AnyEvent::Impl::$model" unless $model =~ s/::$//;
		1365	if (eval "require $model") {
		1366	$MODEL = $model;
		1367	AnyEvent::log 7 => "loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it."
		1368	if $VERBOSE >= 7;
1127	} else {	1369	} else {
1128	push @post_detect, $cb;	1370	AnyEvent::log warn => "unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@";
1129		1371	}
1130	defined wantarray
1131	? bless \$cb, "AnyEvent::Util::postdetect"
1132	: ()
1133	}	1372	}
1134	}
1135		1373
1136	sub AnyEvent::Util::postdetect::DESTROY {	1374	# check for already loaded models
1137	@post_detect = grep $_ != ${$_[0]}, @post_detect;
1138	}
1139
1140	sub detect() {
1141	unless ($MODEL) {	1375	unless ($MODEL) {
1142	local $SIG{__DIE__};	1376	for (@REGISTRY, @models) {
1143		1377	my ($package, $model) = @$_;
1144	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {	1378	if (${"$package\::VERSION"} > 0) {
1145	my $model = "AnyEvent::Impl::$1";
1146	if (eval "require $model") {	1379	if (eval "require $model") {
1147	$MODEL = $model;	1380	$MODEL = $model;
1148	warn "AnyEvent: loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.\n" if $VERBOSE >= 2;	1381	AnyEvent::log 7 => "autodetected model '$model', using it."
1149	} else {	1382	if $VERBOSE >= 7;
1150	warn "AnyEvent: unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@" if $VERBOSE;	1383	last;
		1384	}
1151	}	1385	}
1152	}	1386	}
1153		1387
1154	# check for already loaded models
1155	unless ($MODEL) {	1388	unless ($MODEL) {
		1389	# try to autoload a model
1156	for (@REGISTRY, @models) {	1390	for (@REGISTRY, @models) {
1157	my ($package, $model) = @$_;	1391	my ($package, $model, $autoload) = @$_;
		1392	if (
		1393	$autoload
		1394	and eval "require $package"
1158	if (${"$package\::VERSION"} > 0) {	1395	and ${"$package\::VERSION"} > 0
1159	if (eval "require $model") {	1396	and eval "require $model"
		1397	) {
1160	$MODEL = $model;	1398	$MODEL = $model;
1161	warn "AnyEvent: autodetected model '$model', using it.\n" if $VERBOSE >= 2;	1399	AnyEvent::log 7 => "autoloaded model '$model', using it."
		1400	if $VERBOSE >= 7;
1162	last;	1401	last;
1163	}
1164	}	1402	}
1165	}	1403	}
1166		1404
1167	unless ($MODEL) {
1168	# try to load a model
1169
1170	for (@REGISTRY, @models) {
1171	my ($package, $model) = @$_;
1172	if (eval "require $package"
1173	and ${"$package\::VERSION"} > 0
1174	and eval "require $model") {
1175	$MODEL = $model;
1176	warn "AnyEvent: autoprobed model '$model', using it.\n" if $VERBOSE >= 2;
1177	last;
1178	}
1179	}
1180
1181	$MODEL	1405	$MODEL
1182	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.\n";	1406	or die "AnyEvent: backend autodetection failed - did you properly install AnyEvent?";
1183	}
1184	}	1407	}
1185
1186	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
1187
1188	unshift @ISA, $MODEL;
1189
1190	require AnyEvent::Strict if $ENV{PERL_ANYEVENT_STRICT};
1191
1192	(shift @post_detect)->() while @post_detect;
1193	}	1408	}
1194		1409
		1410	# free memory only needed for probing
		1411	undef @models;
		1412	undef @REGISTRY;
		1413
		1414	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
		1415
		1416	# now nuke some methods that are overridden by the backend.
		1417	# SUPER usage is not allowed in these.
		1418	for (qw(time signal child idle)) {
		1419	undef &{"AnyEvent::Base::$_"}
		1420	if defined &{"$MODEL\::$_"};
		1421	}
		1422
		1423	_isa_set;
		1424
		1425	# we're officially open!
		1426
		1427	if (length $ENV{PERL_ANYEVENT_LOG}) {
		1428	require AnyEvent::Log; # AnyEvent::Log does the thing for us
		1429	}
		1430
		1431	if ($ENV{PERL_ANYEVENT_STRICT}) {
		1432	require AnyEvent::Strict;
		1433	}
		1434
		1435	if ($ENV{PERL_ANYEVENT_DEBUG_WRAP}) {
		1436	require AnyEvent::Debug;
		1437	AnyEvent::Debug::wrap ($ENV{PERL_ANYEVENT_DEBUG_WRAP});
		1438	}
		1439
		1440	if (length $ENV{PERL_ANYEVENT_DEBUG_SHELL}) {
		1441	require AnyEvent::Socket;
		1442	require AnyEvent::Debug;
		1443
		1444	my $shell = $ENV{PERL_ANYEVENT_DEBUG_SHELL};
		1445	$shell =~ s/\$\$/$$/g;
		1446
		1447	my ($host, $service) = AnyEvent::Socket::parse_hostport ($shell);
		1448	$AnyEvent::Debug::SHELL = AnyEvent::Debug::shell ($host, $service);
		1449	}
		1450
		1451	# now the anyevent environment is set up as the user told us to, so
		1452	# call the actual user code - post detects
		1453
		1454	(shift @post_detect)->() while @post_detect;
		1455	undef @post_detect;
		1456
		1457	*post_detect = sub(&) {
		1458	shift->();
		1459
		1460	undef
		1461	};
		1462
1195	$MODEL	1463	$MODEL
1196	}	1464	}
1197		1465
1198	sub AUTOLOAD {	1466	for my $name (@methods) {
1199	(my $func = $AUTOLOAD) =~ s/.*://;	1467	*$name = sub {
1200		1468	detect;
1201	$method{$func}	1469	# we use goto because
1202	or Carp::croak "$func: not a valid method for AnyEvent objects";	1470	# a) it makes the thunk more transparent
1203		1471	# b) it allows us to delete the thunk later
1204	detect unless $MODEL;	1472	goto &{ UNIVERSAL::can AnyEvent => "SUPER::$name" }
1205		1473	};
1206	my $class = shift;
1207	$class->$func (@_);
1208	}	1474	}
1209		1475
1210	# utility function to dup a filehandle. this is used by many backends	1476	# utility function to dup a filehandle. this is used by many backends
1211	# to support binding more than one watcher per filehandle (they usually	1477	# to support binding more than one watcher per filehandle (they usually
1212	# allow only one watcher per fd, so we dup it to get a different one).	1478	# allow only one watcher per fd, so we dup it to get a different one).
…		…
1222	# we assume CLOEXEC is already set by perl in all important cases	1488	# we assume CLOEXEC is already set by perl in all important cases
1223		1489
1224	($fh2, $rw)	1490	($fh2, $rw)
1225	}	1491	}
1226		1492
		1493	=head1 SIMPLIFIED AE API
		1494
		1495	Starting with version 5.0, AnyEvent officially supports a second, much
		1496	simpler, API that is designed to reduce the calling, typing and memory
		1497	overhead by using function call syntax and a fixed number of parameters.
		1498
		1499	See the L<AE> manpage for details.
		1500
		1501	=cut
		1502
		1503	package AE;
		1504
		1505	our $VERSION = $AnyEvent::VERSION;
		1506
		1507	sub _reset() {
		1508	eval q{
		1509	# fall back to the main API by default - backends and AnyEvent::Base
		1510	# implementations can overwrite these.
		1511
		1512	sub io($$$) {
		1513	AnyEvent->io (fh => $_[0], poll => $_[1] ? "w" : "r", cb => $_[2])
		1514	}
		1515
		1516	sub timer($$$) {
		1517	AnyEvent->timer (after => $_[0], interval => $_[1], cb => $_[2])
		1518	}
		1519
		1520	sub signal($$) {
		1521	AnyEvent->signal (signal => $_[0], cb => $_[1])
		1522	}
		1523
		1524	sub child($$) {
		1525	AnyEvent->child (pid => $_[0], cb => $_[1])
		1526	}
		1527
		1528	sub idle($) {
		1529	AnyEvent->idle (cb => $_[0]);
		1530	}
		1531
		1532	sub cv(;&) {
		1533	AnyEvent->condvar (@_ ? (cb => $_[0]) : ())
		1534	}
		1535
		1536	sub now() {
		1537	AnyEvent->now
		1538	}
		1539
		1540	sub now_update() {
		1541	AnyEvent->now_update
		1542	}
		1543
		1544	sub time() {
		1545	AnyEvent->time
		1546	}
		1547
		1548	*postpone = \&AnyEvent::postpone;
		1549	*log = \&AnyEvent::log;
		1550	};
		1551	die if $@;
		1552	}
		1553
		1554	BEGIN { _reset }
		1555
1227	package AnyEvent::Base;	1556	package AnyEvent::Base;
1228		1557
1229	# default implementations for many methods	1558	# default implementations for many methods
1230		1559
1231	sub _time {	1560	sub time {
		1561	eval q{ # poor man's autoloading {}
1232	# probe for availability of Time::HiRes	1562	# probe for availability of Time::HiRes
1233	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {	1563	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {
1234	warn "AnyEvent: using Time::HiRes for sub-second timing accuracy.\n" if $VERBOSE >= 8;	1564	AnyEvent::log 8 => "AnyEvent: using Time::HiRes for sub-second timing accuracy."
		1565	if $AnyEvent::VERBOSE >= 8;
		1566	*time = sub { Time::HiRes::time () };
1235	*_time = \&Time::HiRes::time;	1567	*AE::time = \& Time::HiRes::time ;
1236	# if (eval "use POSIX (); (POSIX::times())...	1568	# if (eval "use POSIX (); (POSIX::times())...
1237	} else {	1569	} else {
1238	warn "AnyEvent: using built-in time(), WARNING, no sub-second resolution!\n" if $VERBOSE;	1570	AnyEvent::log critical => "using built-in time(), WARNING, no sub-second resolution!";
1239	*_time = sub { time }; # epic fail	1571	*time = sub { CORE::time };
		1572	*AE::time = sub (){ CORE::time };
		1573	}
		1574
		1575	*now = \&time;
1240	}	1576	};
		1577	die if $@;
1241		1578
1242	&_time	1579	&time
1243	}	1580	}
1244		1581
1245	sub time { _time }	1582	*now = \&time;
1246	sub now { _time }
1247	sub now_update { }	1583	sub now_update { }
1248		1584
		1585	sub _poll {
		1586	Carp::croak "$AnyEvent::MODEL does not support blocking waits. Caught";
		1587	}
		1588
1249	# default implementation for ->condvar	1589	# default implementation for ->condvar
		1590	# in fact, the default should not be overwritten
1250		1591
1251	sub condvar {	1592	sub condvar {
		1593	eval q{ # poor man's autoloading {}
		1594	*condvar = sub {
1252	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"	1595	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"
		1596	};
		1597
		1598	*AE::cv = sub (;&) {
		1599	bless { @_ ? (_ae_cb => shift) : () }, "AnyEvent::CondVar"
		1600	};
		1601	};
		1602	die if $@;
		1603
		1604	&condvar
1253	}	1605	}
1254		1606
1255	# default implementation for ->signal	1607	# default implementation for ->signal
1256		1608
1257	our $HAVE_ASYNC_INTERRUPT;	1609	our $HAVE_ASYNC_INTERRUPT;
		1610
		1611	sub _have_async_interrupt() {
		1612	$HAVE_ASYNC_INTERRUPT = 1*(!$ENV{PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT}
		1613	&& eval "use Async::Interrupt 1.02 (); 1")
		1614	unless defined $HAVE_ASYNC_INTERRUPT;
		1615
		1616	$HAVE_ASYNC_INTERRUPT
		1617	}
		1618
1258	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);	1619	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);
1259	our (%SIG_ASY, %SIG_ASY_W);	1620	our (%SIG_ASY, %SIG_ASY_W);
1260	our ($SIG_COUNT, $SIG_TW);	1621	our ($SIG_COUNT, $SIG_TW);
1261		1622
1262	sub _signal_exec {
1263	$HAVE_ASYNC_INTERRUPT
1264	? $SIGPIPE_R->drain
1265	: sysread $SIGPIPE_R, my $dummy, 9;
1266
1267	while (%SIG_EV) {
1268	for (keys %SIG_EV) {
1269	delete $SIG_EV{$_};
1270	$_->() for values %{ $SIG_CB{$_} || {} };
1271	}
1272	}
1273	}
1274
1275	# install a dumym wakeupw atcher to reduce signal catching latency	1623	# install a dummy wakeup watcher to reduce signal catching latency
		1624	# used by Impls
1276	sub _sig_add() {	1625	sub _sig_add() {
1277	unless ($SIG_COUNT++) {	1626	unless ($SIG_COUNT++) {
1278	# try to align timer on a full-second boundary, if possible	1627	# try to align timer on a full-second boundary, if possible
1279	my $NOW = AnyEvent->now;	1628	my $NOW = AE::now;
1280		1629
1281	$SIG_TW = AnyEvent->timer (	1630	$SIG_TW = AE::timer
1282	after => $MAX_SIGNAL_LATENCY - ($NOW - int $NOW),	1631	$MAX_SIGNAL_LATENCY - ($NOW - int $NOW),
1283	interval => $MAX_SIGNAL_LATENCY,	1632	$MAX_SIGNAL_LATENCY,
1284	cb => sub { }, # just for the PERL_ASYNC_CHECK	1633	sub { } # just for the PERL_ASYNC_CHECK
1285	);	1634	;
1286	}	1635	}
1287	}	1636	}
1288		1637
1289	sub _sig_del {	1638	sub _sig_del {
1290	undef $SIG_TW	1639	undef $SIG_TW
1291	unless --$SIG_COUNT;	1640	unless --$SIG_COUNT;
1292	}	1641	}
1293		1642
		1643	our $_sig_name_init; $_sig_name_init = sub {
		1644	eval q{ # poor man's autoloading {}
		1645	undef $_sig_name_init;
		1646
		1647	if (_have_async_interrupt) {
		1648	*sig2num = \&Async::Interrupt::sig2num;
		1649	*sig2name = \&Async::Interrupt::sig2name;
		1650	} else {
		1651	require Config;
		1652
		1653	my %signame2num;
		1654	@signame2num{ split ' ', $Config::Config{sig_name} }
		1655	= split ' ', $Config::Config{sig_num};
		1656
		1657	my @signum2name;
		1658	@signum2name[values %signame2num] = keys %signame2num;
		1659
		1660	*sig2num = sub($) {
		1661	$_[0] > 0 ? shift : $signame2num{+shift}
		1662	};
		1663	*sig2name = sub ($) {
		1664	$_[0] > 0 ? $signum2name[+shift] : shift
		1665	};
		1666	}
		1667	};
		1668	die if $@;
		1669	};
		1670
		1671	sub sig2num ($) { &$_sig_name_init; &sig2num }
		1672	sub sig2name($) { &$_sig_name_init; &sig2name }
		1673
1294	sub _signal {	1674	sub signal {
1295	my (undef, %arg) = @_;	1675	eval q{ # poor man's autoloading {}
		1676	# probe for availability of Async::Interrupt
		1677	if (_have_async_interrupt) {
		1678	AnyEvent::log 8 => "using Async::Interrupt for race-free signal handling."
		1679	if $AnyEvent::VERBOSE >= 8;
1296		1680
1297	my $signal = uc $arg{signal}	1681	$SIGPIPE_R = new Async::Interrupt::EventPipe;
1298	or Carp::croak "required option 'signal' is missing";	1682	$SIG_IO = AE::io $SIGPIPE_R->fileno, 0, \&_signal_exec;
1299		1683
1300	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};	1684	} else {
		1685	AnyEvent::log 8 => "using emulated perl signal handling with latency timer."
		1686	if $AnyEvent::VERBOSE >= 8;
1301		1687
1302	if ($HAVE_ASYNC_INTERRUPT) {	1688	if (AnyEvent::WIN32) {
1303	# async::interrupt	1689	require AnyEvent::Util;
1304		1690
1305	$SIG_ASY{$signal} ||= do {	1691	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
1306	my $asy = new Async::Interrupt	1692	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R, 1) if $SIGPIPE_R;
1307	cb => sub { undef $SIG_EV{$signal} },	1693	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W, 1) if $SIGPIPE_W; # just in case
1308	signal => $signal,	1694	} else {
1309	pipe => [$SIGPIPE_R->filenos],	1695	pipe $SIGPIPE_R, $SIGPIPE_W;
		1696	fcntl $SIGPIPE_R, AnyEvent::F_SETFL, AnyEvent::O_NONBLOCK if $SIGPIPE_R;
		1697	fcntl $SIGPIPE_W, AnyEvent::F_SETFL, AnyEvent::O_NONBLOCK if $SIGPIPE_W; # just in case
		1698
		1699	# not strictly required, as $^F is normally 2, but let's make sure...
		1700	fcntl $SIGPIPE_R, AnyEvent::F_SETFD, AnyEvent::FD_CLOEXEC;
		1701	fcntl $SIGPIPE_W, AnyEvent::F_SETFD, AnyEvent::FD_CLOEXEC;
1310	;	1702	}
1311	$asy->pipe_autodrain (0);
1312		1703
1313	$asy	1704	$SIGPIPE_R
		1705	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";
		1706
		1707	$SIG_IO = AE::io $SIGPIPE_R, 0, \&_signal_exec;
		1708	}
		1709
		1710	*signal = $HAVE_ASYNC_INTERRUPT
		1711	? sub {
		1712	my (undef, %arg) = @_;
		1713
		1714	# async::interrupt
		1715	my $signal = sig2num $arg{signal};
		1716	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
		1717
		1718	$SIG_ASY{$signal} ||= new Async::Interrupt
		1719	cb => sub { undef $SIG_EV{$signal} },
		1720	signal => $signal,
		1721	pipe => [$SIGPIPE_R->filenos],
		1722	pipe_autodrain => 0,
		1723	;
		1724
		1725	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
		1726	}
		1727	: sub {
		1728	my (undef, %arg) = @_;
		1729
		1730	# pure perl
		1731	my $signal = sig2name $arg{signal};
		1732	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
		1733
		1734	$SIG{$signal} ||= sub {
		1735	local $!;
		1736	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;
		1737	undef $SIG_EV{$signal};
		1738	};
		1739
		1740	# can't do signal processing without introducing races in pure perl,
		1741	# so limit the signal latency.
		1742	_sig_add;
		1743
		1744	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
		1745	}
		1746	;
		1747
		1748	*AnyEvent::Base::signal::DESTROY = sub {
		1749	my ($signal, $cb) = @{$_[0]};
		1750
		1751	_sig_del;
		1752
		1753	delete $SIG_CB{$signal}{$cb};
		1754
		1755	$HAVE_ASYNC_INTERRUPT
		1756	? delete $SIG_ASY{$signal}
		1757	: # delete doesn't work with older perls - they then
		1758	# print weird messages, or just unconditionally exit
		1759	# instead of getting the default action.
		1760	undef $SIG{$signal}
		1761	unless keys %{ $SIG_CB{$signal} };
1314	};	1762	};
1315		1763
1316	} else {	1764	*_signal_exec = sub {
1317	# pure perl	1765	$HAVE_ASYNC_INTERRUPT
		1766	? $SIGPIPE_R->drain
		1767	: sysread $SIGPIPE_R, (my $dummy), 9;
1318		1768
1319	$SIG{$signal} ||= sub {	1769	while (%SIG_EV) {
1320	local $!;	1770	for (keys %SIG_EV) {
1321	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;	1771	delete $SIG_EV{$_};
1322	undef $SIG_EV{$signal};	1772	&$_ for values %{ $SIG_CB{$_} || {} };
		1773	}
		1774	}
1323	};	1775	};
1324
1325	# can't do signal processing without introducing races in pure perl,
1326	# so limit the signal latency.
1327	_sig_add;
1328	}	1776	};
		1777	die if $@;
1329		1778
1330	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
1331	}
1332
1333	sub signal {
1334	# probe for availability of Async::Interrupt
1335	if (!$ENV{PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT} && eval "use Async::Interrupt 0.6 (); 1") {
1336	warn "AnyEvent: using Async::Interrupt for race-free signal handling.\n" if $VERBOSE >= 8;
1337
1338	$HAVE_ASYNC_INTERRUPT = 1;
1339	$SIGPIPE_R = new Async::Interrupt::EventPipe;
1340	$SIG_IO = AnyEvent->io (fh => $SIGPIPE_R->fileno, poll => "r", cb => \&_signal_exec);
1341
1342	} else {
1343	warn "AnyEvent: using emulated perl signal handling with latency timer.\n" if $VERBOSE >= 8;
1344
1345	require Fcntl;
1346
1347	if (AnyEvent::WIN32) {
1348	require AnyEvent::Util;
1349
1350	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
1351	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R) if $SIGPIPE_R;
1352	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W) if $SIGPIPE_W; # just in case
1353	} else {
1354	pipe $SIGPIPE_R, $SIGPIPE_W;
1355	fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R;
1356	fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case
1357
1358	# not strictly required, as $^F is normally 2, but let's make sure...
1359	fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
1360	fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
1361	}
1362
1363	$SIGPIPE_R
1364	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";
1365
1366	$SIG_IO = AnyEvent->io (fh => $SIGPIPE_R, poll => "r", cb => \&_signal_exec);
1367	}
1368
1369	*signal = \&_signal;
1370	&signal	1779	&signal
1371	}
1372
1373	sub AnyEvent::Base::signal::DESTROY {
1374	my ($signal, $cb) = @{$_[0]};
1375
1376	_sig_del;
1377
1378	delete $SIG_CB{$signal}{$cb};
1379
1380	$HAVE_ASYNC_INTERRUPT
1381	? delete $SIG_ASY{$signal}
1382	: # delete doesn't work with older perls - they then
1383	# print weird messages, or just unconditionally exit
1384	# instead of getting the default action.
1385	undef $SIG{$signal}
1386	unless keys %{ $SIG_CB{$signal} };
1387	}	1780	}
1388		1781
1389	# default implementation for ->child	1782	# default implementation for ->child
1390		1783
1391	our %PID_CB;	1784	our %PID_CB;
1392	our $CHLD_W;	1785	our $CHLD_W;
1393	our $CHLD_DELAY_W;	1786	our $CHLD_DELAY_W;
1394	our $WNOHANG;
1395		1787
1396	sub _sigchld {	1788	# used by many Impl's
1397	while (0 < (my $pid = waitpid -1, $WNOHANG)) {	1789	sub _emit_childstatus($$) {
1398	$_->($pid, $?)	1790	my (undef, $rpid, $rstatus) = @_;
		1791
		1792	$_->($rpid, $rstatus)
1399	for values %{ $PID_CB{$pid} || {} },	1793	for values %{ $PID_CB{$rpid} || {} },
1400	values %{ $PID_CB{0} || {} };	1794	values %{ $PID_CB{0} || {} };
1401	}
1402	}	1795	}
1403		1796
1404	sub child {	1797	sub child {
		1798	eval q{ # poor man's autoloading {}
		1799	*_sigchld = sub {
		1800	my $pid;
		1801
		1802	AnyEvent->_emit_childstatus ($pid, $?)
		1803	while ($pid = waitpid -1, WNOHANG) > 0;
		1804	};
		1805
		1806	*child = sub {
1405	my (undef, %arg) = @_;	1807	my (undef, %arg) = @_;
1406		1808
1407	defined (my $pid = $arg{pid} + 0)	1809	my $pid = $arg{pid};
1408	or Carp::croak "required option 'pid' is missing";	1810	my $cb = $arg{cb};
1409		1811
1410	$PID_CB{$pid}{$arg{cb}} = $arg{cb};	1812	$PID_CB{$pid}{$cb+0} = $cb;
1411		1813
1412	# WNOHANG is almost cetrainly 1 everywhere
1413	$WNOHANG ||= $^O =~ /^(?:openbsd|netbsd|linux|freebsd|cygwin|MSWin32)$/
1414	? 1
1415	: eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1;
1416
1417	unless ($CHLD_W) {	1814	unless ($CHLD_W) {
1418	$CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld);	1815	$CHLD_W = AE::signal CHLD => \&_sigchld;
1419	# child could be a zombie already, so make at least one round	1816	# child could be a zombie already, so make at least one round
1420	&_sigchld;	1817	&_sigchld;
1421	}	1818	}
1422		1819
1423	bless [$pid, $arg{cb}], "AnyEvent::Base::child"	1820	bless [$pid, $cb+0], "AnyEvent::Base::child"
1424	}	1821	};
1425		1822
1426	sub AnyEvent::Base::child::DESTROY {	1823	*AnyEvent::Base::child::DESTROY = sub {
1427	my ($pid, $cb) = @{$_[0]};	1824	my ($pid, $icb) = @{$_[0]};
1428		1825
1429	delete $PID_CB{$pid}{$cb};	1826	delete $PID_CB{$pid}{$icb};
1430	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };	1827	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };
1431		1828
1432	undef $CHLD_W unless keys %PID_CB;	1829	undef $CHLD_W unless keys %PID_CB;
		1830	};
		1831	};
		1832	die if $@;
		1833
		1834	&child
1433	}	1835	}
1434		1836
1435	# idle emulation is done by simply using a timer, regardless	1837	# idle emulation is done by simply using a timer, regardless
1436	# of whether the process is idle or not, and not letting	1838	# of whether the process is idle or not, and not letting
1437	# the callback use more than 50% of the time.	1839	# the callback use more than 50% of the time.
1438	sub idle {	1840	sub idle {
		1841	eval q{ # poor man's autoloading {}
		1842	*idle = sub {
1439	my (undef, %arg) = @_;	1843	my (undef, %arg) = @_;
1440		1844
1441	my ($cb, $w, $rcb) = $arg{cb};	1845	my ($cb, $w, $rcb) = $arg{cb};
1442		1846
1443	$rcb = sub {	1847	$rcb = sub {
1444	if ($cb) {	1848	if ($cb) {
1445	$w = _time;	1849	$w = AE::time;
1446	&$cb;	1850	&$cb;
1447	$w = _time - $w;	1851	$w = AE::time - $w;
1448		1852
1449	# never use more then 50% of the time for the idle watcher,	1853	# never use more then 50% of the time for the idle watcher,
1450	# within some limits	1854	# within some limits
1451	$w = 0.0001 if $w < 0.0001;	1855	$w = 0.0001 if $w < 0.0001;
1452	$w = 5 if $w > 5;	1856	$w = 5 if $w > 5;
1453		1857
1454	$w = AnyEvent->timer (after => $w, cb => $rcb);	1858	$w = AE::timer $w, 0, $rcb;
1455	} else {	1859	} else {
1456	# clean up...	1860	# clean up...
1457	undef $w;	1861	undef $w;
1458	undef $rcb;	1862	undef $rcb;
		1863	}
		1864	};
		1865
		1866	$w = AE::timer 0.05, 0, $rcb;
		1867
		1868	bless \\$cb, "AnyEvent::Base::idle"
1459	}	1869	};
		1870
		1871	*AnyEvent::Base::idle::DESTROY = sub {
		1872	undef $${$_[0]};
		1873	};
1460	};	1874	};
		1875	die if $@;
1461		1876
1462	$w = AnyEvent->timer (after => 0.05, cb => $rcb);	1877	&idle
1463
1464	bless \\$cb, "AnyEvent::Base::idle"
1465	}
1466
1467	sub AnyEvent::Base::idle::DESTROY {
1468	undef $${$_[0]};
1469	}	1878	}
1470		1879
1471	package AnyEvent::CondVar;	1880	package AnyEvent::CondVar;
1472		1881
1473	our @ISA = AnyEvent::CondVar::Base::;	1882	our @ISA = AnyEvent::CondVar::Base::;
		1883
		1884	# only to be used for subclassing
		1885	sub new {
		1886	my $class = shift;
		1887	bless AnyEvent->condvar (@_), $class
		1888	}
1474		1889
1475	package AnyEvent::CondVar::Base;	1890	package AnyEvent::CondVar::Base;
1476		1891
1477	#use overload	1892	#use overload
1478	# '&{}' => sub { my $self = shift; sub { $self->send (@_) } },	1893	# '&{}' => sub { my $self = shift; sub { $self->send (@_) } },
…		…
1488		1903
1489	sub _send {	1904	sub _send {
1490	# nop	1905	# nop
1491	}	1906	}
1492		1907
		1908	sub _wait {
		1909	AnyEvent->_poll until $_[0]{_ae_sent};
		1910	}
		1911
1493	sub send {	1912	sub send {
1494	my $cv = shift;	1913	my $cv = shift;
1495	$cv->{_ae_sent} = [@_];	1914	$cv->{_ae_sent} = [@_];
1496	(delete $cv->{_ae_cb})->($cv) if $cv->{_ae_cb};	1915	(delete $cv->{_ae_cb})->($cv) if $cv->{_ae_cb};
1497	$cv->_send;	1916	$cv->_send;
…		…
1504		1923
1505	sub ready {	1924	sub ready {
1506	$_[0]{_ae_sent}	1925	$_[0]{_ae_sent}
1507	}	1926	}
1508		1927
1509	sub _wait {
1510	$WAITING
1511	and !$_[0]{_ae_sent}
1512	and Carp::croak "AnyEvent::CondVar: recursive blocking wait detected";
1513
1514	local $WAITING = 1;
1515	AnyEvent->one_event while !$_[0]{_ae_sent};
1516	}
1517
1518	sub recv {	1928	sub recv {
		1929	unless ($_[0]{_ae_sent}) {
		1930	$WAITING
		1931	and Carp::croak "AnyEvent::CondVar: recursive blocking wait attempted";
		1932
		1933	local $WAITING = 1;
1519	$_[0]->_wait;	1934	$_[0]->_wait;
		1935	}
1520		1936
1521	Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak};	1937	$_[0]{_ae_croak}
1522	wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0]	1938	and Carp::croak $_[0]{_ae_croak};
		1939
		1940	wantarray
		1941	? @{ $_[0]{_ae_sent} }
		1942	: $_[0]{_ae_sent}[0]
1523	}	1943	}
1524		1944
1525	sub cb {	1945	sub cb {
1526	$_[0]{_ae_cb} = $_[1] if @_ > 1;	1946	my $cv = shift;
		1947
		1948	@_
		1949	and $cv->{_ae_cb} = shift
		1950	and $cv->{_ae_sent}
		1951	and (delete $cv->{_ae_cb})->($cv);
		1952
1527	$_[0]{_ae_cb}	1953	$cv->{_ae_cb}
1528	}	1954	}
1529		1955
1530	sub begin {	1956	sub begin {
1531	++$_[0]{_ae_counter};	1957	++$_[0]{_ae_counter};
1532	$_[0]{_ae_end_cb} = $_[1] if @_ > 1;	1958	$_[0]{_ae_end_cb} = $_[1] if @_ > 1;
…		…
1537	&{ $_[0]{_ae_end_cb} || sub { $_[0]->send } };	1963	&{ $_[0]{_ae_end_cb} || sub { $_[0]->send } };
1538	}	1964	}
1539		1965
1540	# undocumented/compatibility with pre-3.4	1966	# undocumented/compatibility with pre-3.4
1541	*broadcast = \&send;	1967	*broadcast = \&send;
1542	*wait = \&_wait;	1968	*wait = \&recv;
1543		1969
1544	=head1 ERROR AND EXCEPTION HANDLING	1970	=head1 ERROR AND EXCEPTION HANDLING
1545		1971
1546	In general, AnyEvent does not do any error handling - it relies on the	1972	In general, AnyEvent does not do any error handling - it relies on the
1547	caller to do that if required. The L<AnyEvent::Strict> module (see also	1973	caller to do that if required. The L<AnyEvent::Strict> module (see also
…		…
1559	$Event/EV::DIED->() >>, L<Glib> uses C<< install_exception_handler >> and	1985	$Event/EV::DIED->() >>, L<Glib> uses C<< install_exception_handler >> and
1560	so on.	1986	so on.
1561		1987
1562	=head1 ENVIRONMENT VARIABLES	1988	=head1 ENVIRONMENT VARIABLES
1563		1989
1564	The following environment variables are used by this module or its	1990	AnyEvent supports a number of environment variables that tune the
1565	submodules.	1991	runtime behaviour. They are usually evaluated when AnyEvent is
		1992	loaded, initialised, or a submodule that uses them is loaded. Many of
		1993	them also cause AnyEvent to load additional modules - for example,
		1994	C<PERL_ANYEVENT_DEBUG_WRAP> causes the L<AnyEvent::Debug> module to be
		1995	loaded.
1566		1996
1567	Note that AnyEvent will remove I<all> environment variables starting with	1997	All the environment variables documented here start with
1568	C<PERL_ANYEVENT_> from C<%ENV> when it is loaded while taint mode is	1998	C<PERL_ANYEVENT_>, which is what AnyEvent considers its own
1569	enabled.	1999	namespace. Other modules are encouraged (but by no means required) to use
		2000	C<PERL_ANYEVENT_SUBMODULE> if they have registered the AnyEvent::Submodule
		2001	namespace on CPAN, for any submodule. For example, L<AnyEvent::HTTP> could
		2002	be expected to use C<PERL_ANYEVENT_HTTP_PROXY> (it should not access env
		2003	variables starting with C<AE_>, see below).
		2004
		2005	All variables can also be set via the C<AE_> prefix, that is, instead
		2006	of setting C<PERL_ANYEVENT_VERBOSE> you can also set C<AE_VERBOSE>. In
		2007	case there is a clash btween anyevent and another program that uses
		2008	C<AE_something> you can set the corresponding C<PERL_ANYEVENT_something>
		2009	variable to the empty string, as those variables take precedence.
		2010
		2011	When AnyEvent is first loaded, it copies all C<AE_xxx> env variables
		2012	to their C<PERL_ANYEVENT_xxx> counterpart unless that variable already
		2013	exists. If taint mode is on, then AnyEvent will remove I<all> environment
		2014	variables starting with C<PERL_ANYEVENT_> from C<%ENV> (or replace them
		2015	with C<undef> or the empty string, if the corresaponding C<AE_> variable
		2016	is set).
		2017
		2018	The exact algorithm is currently:
		2019
		2020	1. if taint mode enabled, delete all PERL_ANYEVENT_xyz variables from %ENV
		2021	2. copy over AE_xyz to PERL_ANYEVENT_xyz unless the latter alraedy exists
		2022	3. if taint mode enabled, set all PERL_ANYEVENT_xyz variables to undef.
		2023
		2024	This ensures that child processes will not see the C<AE_> variables.
		2025
		2026	The following environment variables are currently known to AnyEvent:
1570		2027
1571	=over 4	2028	=over 4
1572		2029
1573	=item C<PERL_ANYEVENT_VERBOSE>	2030	=item C<PERL_ANYEVENT_VERBOSE>
1574		2031
1575	By default, AnyEvent will be completely silent except in fatal	2032	By default, AnyEvent will be completely silent except in fatal
1576	conditions. You can set this environment variable to make AnyEvent more	2033	conditions. You can set this environment variable to make AnyEvent more
1577	talkative.	2034	talkative. If you want to do more than just set the global logging level
		2035	you should have a look at C<PERL_ANYEVENT_LOG>, which allows much more
		2036	complex specifications.
1578		2037
1579	When set to C<1> or higher, causes AnyEvent to warn about unexpected	2038	When set to C<5> or higher, causes AnyEvent to warn about unexpected
1580	conditions, such as not being able to load the event model specified by	2039	conditions, such as not being able to load the event model specified by
1581	C<PERL_ANYEVENT_MODEL>.	2040	C<PERL_ANYEVENT_MODEL>.
1582		2041
1583	When set to C<2> or higher, cause AnyEvent to report to STDERR which event	2042	When set to C<7> or higher, cause AnyEvent to report to STDERR which event
1584	model it chooses.	2043	model it chooses.
1585		2044
1586	When set to C<8> or higher, then AnyEvent will report extra information on	2045	When set to C<8> or higher, then AnyEvent will report extra information on
1587	which optional modules it loads and how it implements certain features.	2046	which optional modules it loads and how it implements certain features.
		2047
		2048	=item C<PERL_ANYEVENT_LOG>
		2049
		2050	Accepts rather complex logging specifications. For example, you could log
		2051	all C<debug> messages of some module to stderr, warnings and above to
		2052	stderr, and errors and above to syslog, with:
		2053
		2054	PERL_ANYEVENT_LOG=Some::Module=debug,+log:filter=warn,+%syslog:%syslog=error,syslog
		2055
		2056	For the rather extensive details, see L<AnyEvent::Log>.
		2057
		2058	Note that specifying this environment variable causes the L<AnyEvent::Log>
		2059	module to be loaded, while C<PERL_ANYEVENT_VERBOSE> does not, so only
		2060	using the latter saves a few hundred kB of memory until the first message
		2061	is being logged.
1588		2062
1589	=item C<PERL_ANYEVENT_STRICT>	2063	=item C<PERL_ANYEVENT_STRICT>
1590		2064
1591	AnyEvent does not do much argument checking by default, as thorough	2065	AnyEvent does not do much argument checking by default, as thorough
1592	argument checking is very costly. Setting this variable to a true value	2066	argument checking is very costly. Setting this variable to a true value
…		…
1594	check the arguments passed to most method calls. If it finds any problems,	2068	check the arguments passed to most method calls. If it finds any problems,
1595	it will croak.	2069	it will croak.
1596		2070
1597	In other words, enables "strict" mode.	2071	In other words, enables "strict" mode.
1598		2072
1599	Unlike C<use strict> (or it's modern cousin, C<< use L<common::sense>	2073	Unlike C<use strict> (or its modern cousin, C<< use L<common::sense>
1600	>>, it is definitely recommended to keep it off in production. Keeping	2074	>>, it is definitely recommended to keep it off in production. Keeping
1601	C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs	2075	C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs
1602	can be very useful, however.	2076	can be very useful, however.
1603		2077
		2078	=item C<PERL_ANYEVENT_DEBUG_SHELL>
		2079
		2080	If this env variable is set, then its contents will be interpreted by
		2081	C<AnyEvent::Socket::parse_hostport> (after replacing every occurance of
		2082	C<$$> by the process pid) and an C<AnyEvent::Debug::shell> is bound on
		2083	that port. The shell object is saved in C<$AnyEvent::Debug::SHELL>.
		2084
		2085	This takes place when the first watcher is created.
		2086
		2087	For example, to bind a debug shell on a unix domain socket in
		2088	F<< /tmp/debug<pid>.sock >>, you could use this:
		2089
		2090	PERL_ANYEVENT_DEBUG_SHELL=/tmp/debug\$\$.sock perlprog
		2091
		2092	Note that creating sockets in F</tmp> is very unsafe on multiuser
		2093	systems.
		2094
		2095	=item C<PERL_ANYEVENT_DEBUG_WRAP>
		2096
		2097	Can be set to C<0>, C<1> or C<2> and enables wrapping of all watchers for
		2098	debugging purposes. See C<AnyEvent::Debug::wrap> for details.
		2099
1604	=item C<PERL_ANYEVENT_MODEL>	2100	=item C<PERL_ANYEVENT_MODEL>
1605		2101
1606	This can be used to specify the event model to be used by AnyEvent, before	2102	This can be used to specify the event model to be used by AnyEvent, before
1607	auto detection and -probing kicks in. It must be a string consisting	2103	auto detection and -probing kicks in.
1608	entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended	2104
		2105	It normally is a string consisting entirely of ASCII letters (e.g. C<EV>
		2106	or C<IOAsync>). The string C<AnyEvent::Impl::> gets prepended and the
1609	and the resulting module name is loaded and if the load was successful,	2107	resulting module name is loaded and - if the load was successful - used as
1610	used as event model. If it fails to load AnyEvent will proceed with	2108	event model backend. If it fails to load then AnyEvent will proceed with
1611	auto detection and -probing.	2109	auto detection and -probing.
1612		2110
1613	This functionality might change in future versions.	2111	If the string ends with C<::> instead (e.g. C<AnyEvent::Impl::EV::>) then
		2112	nothing gets prepended and the module name is used as-is (hint: C<::> at
		2113	the end of a string designates a module name and quotes it appropriately).
1614		2114
1615	For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you	2115	For example, to force the pure perl model (L<AnyEvent::Loop::Perl>) you
1616	could start your program like this:	2116	could start your program like this:
1617		2117
1618	PERL_ANYEVENT_MODEL=Perl perl ...	2118	PERL_ANYEVENT_MODEL=Perl perl ...
1619		2119
1620	=item C<PERL_ANYEVENT_PROTOCOLS>	2120	=item C<PERL_ANYEVENT_PROTOCOLS>
…		…
1638	addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or	2138	addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or
1639	IPv6, but prefer IPv6 over IPv4.	2139	IPv6, but prefer IPv6 over IPv4.
1640		2140
1641	=item C<PERL_ANYEVENT_EDNS0>	2141	=item C<PERL_ANYEVENT_EDNS0>
1642		2142
1643	Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension	2143	Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension for
1644	for DNS. This extension is generally useful to reduce DNS traffic, but	2144	DNS. This extension is generally useful to reduce DNS traffic, especially
1645	some (broken) firewalls drop such DNS packets, which is why it is off by	2145	when DNSSEC is involved, but some (broken) firewalls drop such DNS
1646	default.	2146	packets, which is why it is off by default.
1647		2147
1648	Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce	2148	Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce
1649	EDNS0 in its DNS requests.	2149	EDNS0 in its DNS requests.
1650		2150
1651	=item C<PERL_ANYEVENT_MAX_FORKS>	2151	=item C<PERL_ANYEVENT_MAX_FORKS>
…		…
1659	resolver - this is the maximum number of parallel DNS requests that are	2159	resolver - this is the maximum number of parallel DNS requests that are
1660	sent to the DNS server.	2160	sent to the DNS server.
1661		2161
1662	=item C<PERL_ANYEVENT_RESOLV_CONF>	2162	=item C<PERL_ANYEVENT_RESOLV_CONF>
1663		2163
1664	The file to use instead of F</etc/resolv.conf> (or OS-specific	2164	The absolute path to a F<resolv.conf>-style file to use instead of
1665	configuration) in the default resolver. When set to the empty string, no	2165	F</etc/resolv.conf> (or the OS-specific configuration) in the default
1666	default config will be used.	2166	resolver, or the empty string to select the default configuration.
1667		2167
1668	=item C<PERL_ANYEVENT_CA_FILE>, C<PERL_ANYEVENT_CA_PATH>.	2168	=item C<PERL_ANYEVENT_CA_FILE>, C<PERL_ANYEVENT_CA_PATH>.
1669		2169
1670	When neither C<ca_file> nor C<ca_path> was specified during	2170	When neither C<ca_file> nor C<ca_path> was specified during
1671	L<AnyEvent::TLS> context creation, and either of these environment	2171	L<AnyEvent::TLS> context creation, and either of these environment
1672	variables exist, they will be used to specify CA certificate locations	2172	variables are nonempty, they will be used to specify CA certificate
1673	instead of a system-dependent default.	2173	locations instead of a system-dependent default.
1674		2174
1675	=item C<PERL_ANYEVENT_AVOID_GUARD> and C<PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT>	2175	=item C<PERL_ANYEVENT_AVOID_GUARD> and C<PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT>
1676		2176
1677	When these are set to C<1>, then the respective modules are not	2177	When these are set to C<1>, then the respective modules are not
1678	loaded. Mostly good for testing AnyEvent itself.	2178	loaded. Mostly good for testing AnyEvent itself.
…		…
1741	warn "read: $input\n"; # output what has been read	2241	warn "read: $input\n"; # output what has been read
1742	$cv->send if $input =~ /^q/i; # quit program if /^q/i	2242	$cv->send if $input =~ /^q/i; # quit program if /^q/i
1743	},	2243	},
1744	);	2244	);
1745		2245
1746	my $time_watcher; # can only be used once
1747
1748	sub new_timer {
1749	$timer = AnyEvent->timer (after => 1, cb => sub {	2246	my $time_watcher = AnyEvent->timer (after => 1, interval => 1, cb => sub {
1750	warn "timeout\n"; # print 'timeout' about every second	2247	warn "timeout\n"; # print 'timeout' at most every second
1751	&new_timer; # and restart the time
1752	});	2248	});
1753	}
1754
1755	new_timer; # create first timer
1756		2249
1757	$cv->recv; # wait until user enters /^q/i	2250	$cv->recv; # wait until user enters /^q/i
1758		2251
1759	=head1 REAL-WORLD EXAMPLE	2252	=head1 REAL-WORLD EXAMPLE
1760		2253
…		…
1833		2326
1834	The actual code goes further and collects all errors (C<die>s, exceptions)	2327	The actual code goes further and collects all errors (C<die>s, exceptions)
1835	that occurred during request processing. The C<result> method detects	2328	that occurred during request processing. The C<result> method detects
1836	whether an exception as thrown (it is stored inside the $txn object)	2329	whether an exception as thrown (it is stored inside the $txn object)
1837	and just throws the exception, which means connection errors and other	2330	and just throws the exception, which means connection errors and other
1838	problems get reported tot he code that tries to use the result, not in a	2331	problems get reported to the code that tries to use the result, not in a
1839	random callback.	2332	random callback.
1840		2333
1841	All of this enables the following usage styles:	2334	All of this enables the following usage styles:
1842		2335
1843	1. Blocking:	2336	1. Blocking:
…		…
1891	through AnyEvent. The benchmark creates a lot of timers (with a zero	2384	through AnyEvent. The benchmark creates a lot of timers (with a zero
1892	timeout) and I/O watchers (watching STDOUT, a pty, to become writable,	2385	timeout) and I/O watchers (watching STDOUT, a pty, to become writable,
1893	which it is), lets them fire exactly once and destroys them again.	2386	which it is), lets them fire exactly once and destroys them again.
1894		2387
1895	Source code for this benchmark is found as F<eg/bench> in the AnyEvent	2388	Source code for this benchmark is found as F<eg/bench> in the AnyEvent
1896	distribution.	2389	distribution. It uses the L<AE> interface, which makes a real difference
		2390	for the EV and Perl backends only.
1897		2391
1898	=head3 Explanation of the columns	2392	=head3 Explanation of the columns
1899		2393
1900	I<watcher> is the number of event watchers created/destroyed. Since	2394	I<watcher> is the number of event watchers created/destroyed. Since
1901	different event models feature vastly different performances, each event	2395	different event models feature vastly different performances, each event
…		…
1922	watcher.	2416	watcher.
1923		2417
1924	=head3 Results	2418	=head3 Results
1925		2419
1926	name watchers bytes create invoke destroy comment	2420	name watchers bytes create invoke destroy comment
1927	EV/EV 400000 224 0.47 0.35 0.27 EV native interface	2421	EV/EV 100000 223 0.47 0.43 0.27 EV native interface
1928	EV/Any 100000 224 2.88 0.34 0.27 EV + AnyEvent watchers	2422	EV/Any 100000 223 0.48 0.42 0.26 EV + AnyEvent watchers
1929	CoroEV/Any 100000 224 2.85 0.35 0.28 coroutines + Coro::Signal	2423	Coro::EV/Any 100000 223 0.47 0.42 0.26 coroutines + Coro::Signal
1930	Perl/Any 100000 452 4.13 0.73 0.95 pure perl implementation	2424	Perl/Any 100000 431 2.70 0.74 0.92 pure perl implementation
1931	Event/Event 16000 517 32.20 31.80 0.81 Event native interface	2425	Event/Event 16000 516 31.16 31.84 0.82 Event native interface
1932	Event/Any 16000 590 35.85 31.55 1.06 Event + AnyEvent watchers	2426	Event/Any 16000 1203 42.61 34.79 1.80 Event + AnyEvent watchers
1933	IOAsync/Any 16000 989 38.10 32.77 11.13 via IO::Async::Loop::IO_Poll	2427	IOAsync/Any 16000 1911 41.92 27.45 16.81 via IO::Async::Loop::IO_Poll
1934	IOAsync/Any 16000 990 37.59 29.50 10.61 via IO::Async::Loop::Epoll	2428	IOAsync/Any 16000 1726 40.69 26.37 15.25 via IO::Async::Loop::Epoll
1935	Glib/Any 16000 1357 102.33 12.31 51.00 quadratic behaviour	2429	Glib/Any 16000 1118 89.00 12.57 51.17 quadratic behaviour
1936	Tk/Any 2000 1860 27.20 66.31 14.00 SEGV with >> 2000 watchers	2430	Tk/Any 2000 1346 20.96 10.75 8.00 SEGV with >> 2000 watchers
1937	POE/Event 2000 6328 109.99 751.67 14.02 via POE::Loop::Event	2431	POE/Any 2000 6951 108.97 795.32 14.24 via POE::Loop::Event
1938	POE/Select 2000 6027 94.54 809.13 579.80 via POE::Loop::Select	2432	POE/Any 2000 6648 94.79 774.40 575.51 via POE::Loop::Select
1939		2433
1940	=head3 Discussion	2434	=head3 Discussion
1941		2435
1942	The benchmark does I<not> measure scalability of the event loop very	2436	The benchmark does I<not> measure scalability of the event loop very
1943	well. For example, a select-based event loop (such as the pure perl one)	2437	well. For example, a select-based event loop (such as the pure perl one)
…		…
1955	benchmark machine, handling an event takes roughly 1600 CPU cycles with	2449	benchmark machine, handling an event takes roughly 1600 CPU cycles with
1956	EV, 3100 CPU cycles with AnyEvent's pure perl loop and almost 3000000 CPU	2450	EV, 3100 CPU cycles with AnyEvent's pure perl loop and almost 3000000 CPU
1957	cycles with POE.	2451	cycles with POE.
1958		2452
1959	C<EV> is the sole leader regarding speed and memory use, which are both	2453	C<EV> is the sole leader regarding speed and memory use, which are both
1960	maximal/minimal, respectively. Even when going through AnyEvent, it uses	2454	maximal/minimal, respectively. When using the L<AE> API there is zero
		2455	overhead (when going through the AnyEvent API create is about 5-6 times
		2456	slower, with other times being equal, so still uses far less memory than
1961	far less memory than any other event loop and is still faster than Event	2457	any other event loop and is still faster than Event natively).
1962	natively.
1963		2458
1964	The pure perl implementation is hit in a few sweet spots (both the	2459	The pure perl implementation is hit in a few sweet spots (both the
1965	constant timeout and the use of a single fd hit optimisations in the perl	2460	constant timeout and the use of a single fd hit optimisations in the perl
1966	interpreter and the backend itself). Nevertheless this shows that it	2461	interpreter and the backend itself). Nevertheless this shows that it
1967	adds very little overhead in itself. Like any select-based backend its	2462	adds very little overhead in itself. Like any select-based backend its
…		…
2015	(even when used without AnyEvent), but most event loops have acceptable	2510	(even when used without AnyEvent), but most event loops have acceptable
2016	performance with or without AnyEvent.	2511	performance with or without AnyEvent.
2017		2512
2018	=item * The overhead AnyEvent adds is usually much smaller than the overhead of	2513	=item * The overhead AnyEvent adds is usually much smaller than the overhead of
2019	the actual event loop, only with extremely fast event loops such as EV	2514	the actual event loop, only with extremely fast event loops such as EV
2020	adds AnyEvent significant overhead.	2515	does AnyEvent add significant overhead.
2021		2516
2022	=item * You should avoid POE like the plague if you want performance or	2517	=item * You should avoid POE like the plague if you want performance or
2023	reasonable memory usage.	2518	reasonable memory usage.
2024		2519
2025	=back	2520	=back
…		…
2041	In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100	2536	In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100
2042	(1%) are active. This mirrors the activity of large servers with many	2537	(1%) are active. This mirrors the activity of large servers with many
2043	connections, most of which are idle at any one point in time.	2538	connections, most of which are idle at any one point in time.
2044		2539
2045	Source code for this benchmark is found as F<eg/bench2> in the AnyEvent	2540	Source code for this benchmark is found as F<eg/bench2> in the AnyEvent
2046	distribution.	2541	distribution. It uses the L<AE> interface, which makes a real difference
		2542	for the EV and Perl backends only.
2047		2543
2048	=head3 Explanation of the columns	2544	=head3 Explanation of the columns
2049		2545
2050	I<sockets> is the number of sockets, and twice the number of "servers" (as	2546	I<sockets> is the number of sockets, and twice the number of "servers" (as
2051	each server has a read and write socket end).	2547	each server has a read and write socket end).
…		…
2059	a new one that moves the timeout into the future.	2555	a new one that moves the timeout into the future.
2060		2556
2061	=head3 Results	2557	=head3 Results
2062		2558
2063	name sockets create request	2559	name sockets create request
2064	EV 20000 69.01 11.16	2560	EV 20000 62.66 7.99
2065	Perl 20000 73.32 35.87	2561	Perl 20000 68.32 32.64
2066	IOAsync 20000 157.00 98.14 epoll	2562	IOAsync 20000 174.06 101.15 epoll
2067	IOAsync 20000 159.31 616.06 poll	2563	IOAsync 20000 174.67 610.84 poll
2068	Event 20000 212.62 257.32	2564	Event 20000 202.69 242.91
2069	Glib 20000 651.16 1896.30	2565	Glib 20000 557.01 1689.52
2070	POE 20000 349.67 12317.24 uses POE::Loop::Event	2566	POE 20000 341.54 12086.32 uses POE::Loop::Event
2071		2567
2072	=head3 Discussion	2568	=head3 Discussion
2073		2569
2074	This benchmark I<does> measure scalability and overall performance of the	2570	This benchmark I<does> measure scalability and overall performance of the
2075	particular event loop.	2571	particular event loop.
…		…
2201	As you can see, the AnyEvent + EV combination even beats the	2697	As you can see, the AnyEvent + EV combination even beats the
2202	hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl	2698	hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl
2203	backend easily beats IO::Lambda and POE.	2699	backend easily beats IO::Lambda and POE.
2204		2700
2205	And even the 100% non-blocking version written using the high-level (and	2701	And even the 100% non-blocking version written using the high-level (and
2206	slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda by a	2702	slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda
2207	large margin, even though it does all of DNS, tcp-connect and socket I/O	2703	higher level ("unoptimised") abstractions by a large margin, even though
2208	in a non-blocking way.	2704	it does all of DNS, tcp-connect and socket I/O in a non-blocking way.
2209		2705
2210	The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and	2706	The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and
2211	F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are	2707	F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are
2212	part of the IO::lambda distribution and were used without any changes.	2708	part of the IO::Lambda distribution and were used without any changes.
2213		2709
2214		2710
2215	=head1 SIGNALS	2711	=head1 SIGNALS
2216		2712
2217	AnyEvent currently installs handlers for these signals:	2713	AnyEvent currently installs handlers for these signals:
…		…
2254	unless defined $SIG{PIPE};	2750	unless defined $SIG{PIPE};
2255		2751
2256	=head1 RECOMMENDED/OPTIONAL MODULES	2752	=head1 RECOMMENDED/OPTIONAL MODULES
2257		2753
2258	One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and	2754	One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and
2259	it's built-in modules) are required to use it.	2755	its built-in modules) are required to use it.
2260		2756
2261	That does not mean that AnyEvent won't take advantage of some additional	2757	That does not mean that AnyEvent won't take advantage of some additional
2262	modules if they are installed.	2758	modules if they are installed.
2263		2759
2264	This section epxlains which additional modules will be used, and how they	2760	This section explains which additional modules will be used, and how they
2265	affect AnyEvent's operetion.	2761	affect AnyEvent's operation.
2266		2762
2267	=over 4	2763	=over 4
2268		2764
2269	=item L<Async::Interrupt>	2765	=item L<Async::Interrupt>
2270		2766
2271	This slightly arcane module is used to implement fast signal handling: To	2767	This slightly arcane module is used to implement fast signal handling: To
2272	my knowledge, there is no way to do completely race-free and quick	2768	my knowledge, there is no way to do completely race-free and quick
2273	signal handling in pure perl. To ensure that signals still get	2769	signal handling in pure perl. To ensure that signals still get
2274	delivered, AnyEvent will start an interval timer to wake up perl (and	2770	delivered, AnyEvent will start an interval timer to wake up perl (and
2275	catch the signals) with soemd elay (default is 10 seconds, look for	2771	catch the signals) with some delay (default is 10 seconds, look for
2276	C<$AnyEvent::MAX_SIGNAL_LATENCY>).	2772	C<$AnyEvent::MAX_SIGNAL_LATENCY>).
2277		2773
2278	If this module is available, then it will be used to implement signal	2774	If this module is available, then it will be used to implement signal
2279	catching, which means that signals will not be delayed, and the event loop	2775	catching, which means that signals will not be delayed, and the event loop
2280	will not be interrupted regularly, which is more efficient (And good for	2776	will not be interrupted regularly, which is more efficient (and good for
2281	battery life on laptops).	2777	battery life on laptops).
2282		2778
2283	This affects not just the pure-perl event loop, but also other event loops	2779	This affects not just the pure-perl event loop, but also other event loops
2284	that have no signal handling on their own (e.g. Glib, Tk, Qt).	2780	that have no signal handling on their own (e.g. Glib, Tk, Qt).
		2781
		2782	Some event loops (POE, Event, Event::Lib) offer signal watchers natively,
		2783	and either employ their own workarounds (POE) or use AnyEvent's workaround
		2784	(using C<$AnyEvent::MAX_SIGNAL_LATENCY>). Installing L<Async::Interrupt>
		2785	does nothing for those backends.
2285		2786
2286	=item L<EV>	2787	=item L<EV>
2287		2788
2288	This module isn't really "optional", as it is simply one of the backend	2789	This module isn't really "optional", as it is simply one of the backend
2289	event loops that AnyEvent can use. However, it is simply the best event	2790	event loops that AnyEvent can use. However, it is simply the best event
…		…
2292	automatic timer adjustments even when no monotonic clock is available,	2793	automatic timer adjustments even when no monotonic clock is available,
2293	can take avdantage of advanced kernel interfaces such as C<epoll> and	2794	can take avdantage of advanced kernel interfaces such as C<epoll> and
2294	C<kqueue>, and is the fastest backend I<by far>. You can even embed	2795	C<kqueue>, and is the fastest backend I<by far>. You can even embed
2295	L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>).	2796	L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>).
2296		2797
		2798	If you only use backends that rely on another event loop (e.g. C<Tk>),
		2799	then this module will do nothing for you.
		2800
2297	=item L<Guard>	2801	=item L<Guard>
2298		2802
2299	The guard module, when used, will be used to implement	2803	The guard module, when used, will be used to implement
2300	C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a	2804	C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a
2301	lot less memory), but otherwise doesn't affect guard operation much. It is	2805	lot less memory), but otherwise doesn't affect guard operation much. It is
2302	purely used for performance.	2806	purely used for performance.
2303		2807
2304	=item L<JSON> and L<JSON::XS>	2808	=item L<JSON> and L<JSON::XS>
2305		2809
2306	This module is required when you want to read or write JSON data via	2810	One of these modules is required when you want to read or write JSON data
2307	L<AnyEvent::Handle>. It is also written in pure-perl, but can take	2811	via L<AnyEvent::Handle>. L<JSON> is also written in pure-perl, but can take
2308	advantage of the ulta-high-speed L<JSON::XS> module when it is installed.	2812	advantage of the ultra-high-speed L<JSON::XS> module when it is installed.
2309
2310	In fact, L<AnyEvent::Handle> will use L<JSON::XS> by default if it is
2311	installed.
2312		2813
2313	=item L<Net::SSLeay>	2814	=item L<Net::SSLeay>
2314		2815
2315	Implementing TLS/SSL in Perl is certainly interesting, but not very	2816	Implementing TLS/SSL in Perl is certainly interesting, but not very
2316	worthwhile: If this module is installed, then L<AnyEvent::Handle> (with	2817	worthwhile: If this module is installed, then L<AnyEvent::Handle> (with
2317	the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL.	2818	the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL.
2318		2819
2319	=item L<Time::HiRes>	2820	=item L<Time::HiRes>
2320		2821
2321	This module is part of perl since release 5.008. It will be used when the	2822	This module is part of perl since release 5.008. It will be used when the
2322	chosen event library does not come with a timing source on it's own. The	2823	chosen event library does not come with a timing source of its own. The
2323	pure-perl event loop (L<AnyEvent::Impl::Perl>) will additionally use it to	2824	pure-perl event loop (L<AnyEvent::Loop>) will additionally load it to
2324	try to use a monotonic clock for timing stability.	2825	try to use a monotonic clock for timing stability.
2325		2826
2326	=back	2827	=back
2327		2828
2328		2829
2329	=head1 FORK	2830	=head1 FORK
2330		2831
2331	Most event libraries are not fork-safe. The ones who are usually are	2832	Most event libraries are not fork-safe. The ones who are usually are
2332	because they rely on inefficient but fork-safe C<select> or C<poll>	2833	because they rely on inefficient but fork-safe C<select> or C<poll> calls
2333	calls. Only L<EV> is fully fork-aware.	2834	- higher performance APIs such as BSD's kqueue or the dreaded Linux epoll
		2835	are usually badly thought-out hacks that are incompatible with fork in
		2836	one way or another. Only L<EV> is fully fork-aware and ensures that you
		2837	continue event-processing in both parent and child (or both, if you know
		2838	what you are doing).
		2839
		2840	This means that, in general, you cannot fork and do event processing in
		2841	the child if the event library was initialised before the fork (which
		2842	usually happens when the first AnyEvent watcher is created, or the library
		2843	is loaded).
2334		2844
2335	If you have to fork, you must either do so I<before> creating your first	2845	If you have to fork, you must either do so I<before> creating your first
2336	watcher OR you must not use AnyEvent at all in the child OR you must do	2846	watcher OR you must not use AnyEvent at all in the child OR you must do
2337	something completely out of the scope of AnyEvent.	2847	something completely out of the scope of AnyEvent.
		2848
		2849	The problem of doing event processing in the parent I<and> the child
		2850	is much more complicated: even for backends that I<are> fork-aware or
		2851	fork-safe, their behaviour is not usually what you want: fork clones all
		2852	watchers, that means all timers, I/O watchers etc. are active in both
		2853	parent and child, which is almost never what you want. USing C<exec>
		2854	to start worker children from some kind of manage rprocess is usually
		2855	preferred, because it is much easier and cleaner, at the expense of having
		2856	to have another binary.
2338		2857
2339		2858
2340	=head1 SECURITY CONSIDERATIONS	2859	=head1 SECURITY CONSIDERATIONS
2341		2860
2342	AnyEvent can be forced to load any event model via	2861	AnyEvent can be forced to load any event model via
…		…
2372	pronounced).	2891	pronounced).
2373		2892
2374		2893
2375	=head1 SEE ALSO	2894	=head1 SEE ALSO
2376		2895
2377	Utility functions: L<AnyEvent::Util>.	2896	Tutorial/Introduction: L<AnyEvent::Intro>.
2378		2897
2379	Event modules: L<EV>, L<EV::Glib>, L<Glib::EV>, L<Event>, L<Glib::Event>,	2898	FAQ: L<AnyEvent::FAQ>.
2380	L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.	2899
		2900	Utility functions: L<AnyEvent::Util> (misc. grab-bag), L<AnyEvent::Log>
		2901	(simply logging).
		2902
		2903	Development/Debugging: L<AnyEvent::Strict> (stricter checking),
		2904	L<AnyEvent::Debug> (interactive shell, watcher tracing).
		2905
		2906	Supported event modules: L<AnyEvent::Loop>, L<EV>, L<EV::Glib>,
		2907	L<Glib::EV>, L<Event>, L<Glib::Event>, L<Glib>, L<Tk>, L<Event::Lib>,
		2908	L<Qt>, L<POE>, L<FLTK>.
2381		2909
2382	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,	2910	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,
2383	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,	2911	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,
2384	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,	2912	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,
2385	L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>.	2913	L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>, L<Anyevent::Impl::Irssi>,
		2914	L<AnyEvent::Impl::FLTK>.
2386		2915
2387	Non-blocking file handles, sockets, TCP clients and	2916	Non-blocking handles, pipes, stream sockets, TCP clients and
2388	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.	2917	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.
2389		2918
2390	Asynchronous DNS: L<AnyEvent::DNS>.	2919	Asynchronous DNS: L<AnyEvent::DNS>.
2391		2920
2392	Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>,	2921	Thread support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>.
2393	L<Coro::Event>,
2394		2922
2395	Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::XMPP>,	2923	Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::IRC>,
2396	L<AnyEvent::HTTP>.	2924	L<AnyEvent::HTTP>.
2397		2925
2398		2926
2399	=head1 AUTHOR	2927	=head1 AUTHOR
2400		2928

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