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Revision 1.266 by root, Thu Jul 30 03:41:56 2009 UTC vs.
Revision 1.389 by root, Tue Oct 4 05:34:50 2011 UTC

1	=head1 NAME	1	=head1 NAME
2		2
3	AnyEvent - the DBI of event loop programming	3	AnyEvent - the DBI of event loop programming
4		4
5	EV, Event, Glib, Tk, Perl, Event::Lib, Irssi, rxvt-unicode, IO::Async, Qt	5	EV, Event, Glib, Tk, Perl, Event::Lib, Irssi, rxvt-unicode, IO::Async, Qt,
6	and POE are various supported event loops/environments.	6	FLTK and POE are various supported event loops/environments.
7		7
8	=head1 SYNOPSIS	8	=head1 SYNOPSIS
9		9
10	use AnyEvent;	10	use AnyEvent;
11		11
		12	# if you prefer function calls, look at the AE manpage for
		13	# an alternative API.
		14
12	# file descriptor readable	15	# file handle or descriptor readable
13	my $w = AnyEvent->io (fh => $fh, poll => "r", cb => sub { ... });	16	my $w = AnyEvent->io (fh => $fh, poll => "r", cb => sub { ... });
14		17
15	# one-shot or repeating timers	18	# one-shot or repeating timers
16	my $w = AnyEvent->timer (after => $seconds, cb => sub { ... });	19	my $w = AnyEvent->timer (after => $seconds, cb => sub { ... });
17	my $w = AnyEvent->timer (after => $seconds, interval => $seconds, cb => ...	20	my $w = AnyEvent->timer (after => $seconds, interval => $seconds, cb => ...);
18		21
19	print AnyEvent->now; # prints current event loop time	22	print AnyEvent->now; # prints current event loop time
20	print AnyEvent->time; # think Time::HiRes::time or simply CORE::time.	23	print AnyEvent->time; # think Time::HiRes::time or simply CORE::time.
21		24
22	# POSIX signal	25	# POSIX signal
…		…
43	in a tutorial or some gentle introduction, have a look at the	46	in a tutorial or some gentle introduction, have a look at the
44	L<AnyEvent::Intro> manpage.	47	L<AnyEvent::Intro> manpage.
45		48
46	=head1 SUPPORT	49	=head1 SUPPORT
47		50
		51	An FAQ document is available as L<AnyEvent::FAQ>.
		52
48	There is a mailinglist for discussing all things AnyEvent, and an IRC	53	There also is a mailinglist for discussing all things AnyEvent, and an IRC
49	channel, too.	54	channel, too.
50		55
51	See the AnyEvent project page at the B<Schmorpforge Ta-Sa Software	56	See the AnyEvent project page at the B<Schmorpforge Ta-Sa Software
52	Repository>, at L<http://anyevent.schmorp.de>, for more info.	57	Repository>, at L<http://anyevent.schmorp.de>, for more info.
53		58
…		…
73	module users into the same thing by forcing them to use the same event	78	module users into the same thing by forcing them to use the same event
74	model you use.	79	model you use.
75		80
76	For modules like POE or IO::Async (which is a total misnomer as it is	81	For modules like POE or IO::Async (which is a total misnomer as it is
77	actually doing all I/O I<synchronously>...), using them in your module is	82	actually doing all I/O I<synchronously>...), using them in your module is
78	like joining a cult: After you joined, you are dependent on them and you	83	like joining a cult: After you join, you are dependent on them and you
79	cannot use anything else, as they are simply incompatible to everything	84	cannot use anything else, as they are simply incompatible to everything
80	that isn't them. What's worse, all the potential users of your	85	that isn't them. What's worse, all the potential users of your
81	module are I<also> forced to use the same event loop you use.	86	module are I<also> forced to use the same event loop you use.
82		87
83	AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works	88	AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works
84	fine. AnyEvent + Tk works fine etc. etc. but none of these work together	89	fine. AnyEvent + Tk works fine etc. etc. but none of these work together
85	with the rest: POE + IO::Async? No go. Tk + Event? No go. Again: if	90	with the rest: POE + EV? No go. Tk + Event? No go. Again: if your module
86	your module uses one of those, every user of your module has to use it,	91	uses one of those, every user of your module has to use it, too. But if
87	too. But if your module uses AnyEvent, it works transparently with all	92	your module uses AnyEvent, it works transparently with all event models it
88	event models it supports (including stuff like IO::Async, as long as those	93	supports (including stuff like IO::Async, as long as those use one of the
89	use one of the supported event loops. It is trivial to add new event loops	94	supported event loops. It is easy to add new event loops to AnyEvent, too,
90	to AnyEvent, too, so it is future-proof).	95	so it is future-proof).
91		96
92	In addition to being free of having to use I<the one and only true event	97	In addition to being free of having to use I<the one and only true event
93	model>, AnyEvent also is free of bloat and policy: with POE or similar	98	model>, AnyEvent also is free of bloat and policy: with POE or similar
94	modules, you get an enormous amount of code and strict rules you have to	99	modules, you get an enormous amount of code and strict rules you have to
95	follow. AnyEvent, on the other hand, is lean and up to the point, by only	100	follow. AnyEvent, on the other hand, is lean and to the point, by only
96	offering the functionality that is necessary, in as thin as a wrapper as	101	offering the functionality that is necessary, in as thin as a wrapper as
97	technically possible.	102	technically possible.
98		103
99	Of course, AnyEvent comes with a big (and fully optional!) toolbox	104	Of course, AnyEvent comes with a big (and fully optional!) toolbox
100	of useful functionality, such as an asynchronous DNS resolver, 100%	105	of useful functionality, such as an asynchronous DNS resolver, 100%
…		…
106	useful) and you want to force your users to use the one and only event	111	useful) and you want to force your users to use the one and only event
107	model, you should I<not> use this module.	112	model, you should I<not> use this module.
108		113
109	=head1 DESCRIPTION	114	=head1 DESCRIPTION
110		115
111	L<AnyEvent> provides an identical interface to multiple event loops. This	116	L<AnyEvent> provides a uniform interface to various event loops. This
112	allows module authors to utilise an event loop without forcing module	117	allows module authors to use event loop functionality without forcing
113	users to use the same event loop (as only a single event loop can coexist	118	module users to use a specific event loop implementation (since more
114	peacefully at any one time).	119	than one event loop cannot coexist peacefully).
115		120
116	The interface itself is vaguely similar, but not identical to the L<Event>	121	The interface itself is vaguely similar, but not identical to the L<Event>
117	module.	122	module.
118		123
119	During the first call of any watcher-creation method, the module tries	124	During the first call of any watcher-creation method, the module tries
120	to detect the currently loaded event loop by probing whether one of the	125	to detect the currently loaded event loop by probing whether one of the
121	following modules is already loaded: L<EV>,	126	following modules is already loaded: L<EV>, L<AnyEvent::Loop>,
122	L<Event>, L<Glib>, L<AnyEvent::Impl::Perl>, L<Tk>, L<Event::Lib>, L<Qt>,	127	L<Event>, L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>. The first one
123	L<POE>. The first one found is used. If none are found, the module tries	128	found is used. If none are detected, the module tries to load the first
124	to load these modules (excluding Tk, Event::Lib, Qt and POE as the pure perl	129	four modules in the order given; but note that if L<EV> is not
125	adaptor should always succeed) in the order given. The first one that can	130	available, the pure-perl L<AnyEvent::Loop> should always work, so
126	be successfully loaded will be used. If, after this, still none could be	131	the other two are not normally tried.
127	found, AnyEvent will fall back to a pure-perl event loop, which is not
128	very efficient, but should work everywhere.
129		132
130	Because AnyEvent first checks for modules that are already loaded, loading	133	Because AnyEvent first checks for modules that are already loaded, loading
131	an event model explicitly before first using AnyEvent will likely make	134	an event model explicitly before first using AnyEvent will likely make
132	that model the default. For example:	135	that model the default. For example:
133		136
…		…
135	use AnyEvent;	138	use AnyEvent;
136		139
137	# .. AnyEvent will likely default to Tk	140	# .. AnyEvent will likely default to Tk
138		141
139	The I<likely> means that, if any module loads another event model and	142	The I<likely> means that, if any module loads another event model and
140	starts using it, all bets are off. Maybe you should tell their authors to	143	starts using it, all bets are off - this case should be very rare though,
141	use AnyEvent so their modules work together with others seamlessly...	144	as very few modules hardcode event loops without announcing this very
		145	loudly.
142		146
143	The pure-perl implementation of AnyEvent is called	147	The pure-perl implementation of AnyEvent is called C<AnyEvent::Loop>. Like
144	C<AnyEvent::Impl::Perl>. Like other event modules you can load it	148	other event modules you can load it explicitly and enjoy the high
145	explicitly and enjoy the high availability of that event loop :)	149	availability of that event loop :)
146		150
147	=head1 WATCHERS	151	=head1 WATCHERS
148		152
149	AnyEvent has the central concept of a I<watcher>, which is an object that	153	AnyEvent has the central concept of a I<watcher>, which is an object that
150	stores relevant data for each kind of event you are waiting for, such as	154	stores relevant data for each kind of event you are waiting for, such as
…		…
155	callback when the event occurs (of course, only when the event model	159	callback when the event occurs (of course, only when the event model
156	is in control).	160	is in control).
157		161
158	Note that B<callbacks must not permanently change global variables>	162	Note that B<callbacks must not permanently change global variables>
159	potentially in use by the event loop (such as C<$_> or C<$[>) and that B<<	163	potentially in use by the event loop (such as C<$_> or C<$[>) and that B<<
160	callbacks must not C<die> >>. The former is good programming practise in	164	callbacks must not C<die> >>. The former is good programming practice in
161	Perl and the latter stems from the fact that exception handling differs	165	Perl and the latter stems from the fact that exception handling differs
162	widely between event loops.	166	widely between event loops.
163		167
164	To disable the watcher you have to destroy it (e.g. by setting the	168	To disable a watcher you have to destroy it (e.g. by setting the
165	variable you store it in to C<undef> or otherwise deleting all references	169	variable you store it in to C<undef> or otherwise deleting all references
166	to it).	170	to it).
167		171
168	All watchers are created by calling a method on the C<AnyEvent> class.	172	All watchers are created by calling a method on the C<AnyEvent> class.
169		173
170	Many watchers either are used with "recursion" (repeating timers for	174	Many watchers either are used with "recursion" (repeating timers for
171	example), or need to refer to their watcher object in other ways.	175	example), or need to refer to their watcher object in other ways.
172		176
173	An any way to achieve that is this pattern:	177	One way to achieve that is this pattern:
174		178
175	my $w; $w = AnyEvent->type (arg => value ..., cb => sub {	179	my $w; $w = AnyEvent->type (arg => value ..., cb => sub {
176	# you can use $w here, for example to undef it	180	# you can use $w here, for example to undef it
177	undef $w;	181	undef $w;
178	});	182	});
…		…
210		214
211	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.
212	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
213	underlying file descriptor.	217	underlying file descriptor.
214		218
215	Some event loops issue spurious readyness notifications, so you should	219	Some event loops issue spurious readiness notifications, so you should
216	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
217	handles.	221	handles.
218		222
219	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
220	watcher.	224	watcher.
…		…
244		248
245	Although the callback might get passed parameters, their value and	249	Although the callback might get passed parameters, their value and
246	presence is undefined and you cannot rely on them. Portable AnyEvent	250	presence is undefined and you cannot rely on them. Portable AnyEvent
247	callbacks cannot use arguments passed to time watcher callbacks.	251	callbacks cannot use arguments passed to time watcher callbacks.
248		252
249	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
250	parameter, C<interval>, as a strictly positive number (> 0), then the	254	parameter, C<interval>, as a strictly positive number (> 0), then the
251	callback will be invoked regularly at that interval (in fractional	255	callback will be invoked regularly at that interval (in fractional
252	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
253	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.
254		258
255	The callback will be rescheduled before invoking the callback, but no	259	The callback will be rescheduled before invoking the callback, but no
256	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
257	only approximate.	261	only approximate.
258		262
259	Example: fire an event after 7.7 seconds.	263	Example: fire an event after 7.7 seconds.
260		264
261	my $w = AnyEvent->timer (after => 7.7, cb => sub {	265	my $w = AnyEvent->timer (after => 7.7, cb => sub {
…		…
279		283
280	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
281	use absolute time internally. This makes a difference when your clock	285	use absolute time internally. This makes a difference when your clock
282	"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
283	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
284	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.
285		289
286	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
287	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
288	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)
289	timers.	293	timers.
290		294
291	AnyEvent always prefers relative timers, if available, matching the	295	AnyEvent always prefers relative timers, if available, matching the
292	AnyEvent API.	296	AnyEvent API.
…		…
314	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
315	function to call when you want to know the current time.>	319	function to call when you want to know the current time.>
316		320
317	This function is also often faster then C<< AnyEvent->time >>, and	321	This function is also often faster then C<< AnyEvent->time >>, and
318	thus the preferred method if you want some timestamp (for example,	322	thus the preferred method if you want some timestamp (for example,
319	L<AnyEvent::Handle> uses this to update it's activity timeouts).	323	L<AnyEvent::Handle> uses this to update its activity timeouts).
320		324
321	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
322	with your timing, you can skip it without bad conscience.	326	with your timing; you can skip it without a bad conscience.
323		327
324	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>
325	and L<EV> and the following set-up:	329	and L<EV> and the following set-up:
326		330
327	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
328	time=500 (assume no other callbacks delay processing). In your callback,	332	time=500 (assume no other callbacks delay processing). In your callback,
329	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
330	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
331	after three seconds.	335	after three seconds.
332		336
…		…
352	difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into	356	difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into
353	account.	357	account.
354		358
355	=item AnyEvent->now_update	359	=item AnyEvent->now_update
356		360
357	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
358	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 >>,
359	AnyEvent->now >>, above).	363	above).
360		364
361	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
362	this "current" time will differ substantially from the real time, which	366	this "current" time will differ substantially from the real time, which
363	might affect timers and time-outs.	367	might affect timers and time-outs.
364		368
365	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
366	event loop's idea of "current time".	370	event loop's idea of "current time".
		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).
367		378
368	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.
369		380
370	=back	381	=back
371		382
…		…
396		407
397	Example: exit on SIGINT	408	Example: exit on SIGINT
398		409
399	my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });	410	my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });
400		411
		412	=head3 Restart Behaviour
		413
		414	While restart behaviour is up to the event loop implementation, most will
		415	not restart syscalls (that includes L<Async::Interrupt> and AnyEvent's
		416	pure perl implementation).
		417
		418	=head3 Safe/Unsafe Signals
		419
		420	Perl signals can be either "safe" (synchronous to opcode handling)
		421	or "unsafe" (asynchronous) - the former might delay signal delivery
		422	indefinitely, the latter might corrupt your memory.
		423
		424	AnyEvent signal handlers are, in addition, synchronous to the event loop,
		425	i.e. they will not interrupt your running perl program but will only be
		426	called as part of the normal event handling (just like timer, I/O etc.
		427	callbacks, too).
		428
401	=head3 Signal Races, Delays and Workarounds	429	=head3 Signal Races, Delays and Workarounds
402		430
403	Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support attaching	431	Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support
404	callbacks to signals in a generic way, which is a pity, as you cannot do	432	attaching callbacks to signals in a generic way, which is a pity,
405	race-free signal handling in perl. AnyEvent will try to do it's best, but	433	as you cannot do race-free signal handling in perl, requiring
		434	C libraries for this. AnyEvent will try to do its best, which
406	in some cases, signals will be delayed. The maximum time a signal might	435	means in some cases, signals will be delayed. The maximum time
407	be delayed is specified in C<$AnyEvent::MAX_SIGNAL_LATENCY> (default: 10	436	a signal might be delayed is 10 seconds by default, but can
408	seconds). This variable can be changed only before the first signal	437	be overriden via C<$ENV{PERL_ANYEVENT_MAX_SIGNAL_LATENCY}> or
409	watcher is created, and should be left alone otherwise. Higher values	438	C<$AnyEvent::MAX_SIGNAL_LATENCY> - see the Ö<ENVIRONMENT VARIABLES>
410	will cause fewer spurious wake-ups, which is better for power and CPU	439	section for details.
		440
411	saving. All these problems can be avoided by installing the optional	441	All these problems can be avoided by installing the optional
412	L<Async::Interrupt> module. This will not work with inherently broken	442	L<Async::Interrupt> module, which works with most event loops. It will not
413	event loops such as L<Event> or L<Event::Lib> (and not with L<POE>	443	work with inherently broken event loops such as L<Event> or L<Event::Lib>
414	currently, as POE does it's own workaround with one-second latency). With	444	(and not with L<POE> currently). For those, you just have to suffer the
415	those, you just have to suffer the delays.	445	delays.
416		446
417	=head2 CHILD PROCESS WATCHERS	447	=head2 CHILD PROCESS WATCHERS
418		448
419	$w = AnyEvent->child (pid => <process id>, cb => <callback>);	449	$w = AnyEvent->child (pid => <process id>, cb => <callback>);
420		450
421	You can also watch on a child process exit and catch its exit status.	451	You can also watch for a child process exit and catch its exit status.
422		452
423	The child process is specified by the C<pid> argument (one some backends,	453	The child process is specified by the C<pid> argument (on some backends,
424	using C<0> watches for any child process exit, on others this will	454	using C<0> watches for any child process exit, on others this will
425	croak). The watcher will be triggered only when the child process has	455	croak). The watcher will be triggered only when the child process has
426	finished and an exit status is available, not on any trace events	456	finished and an exit status is available, not on any trace events
427	(stopped/continued).	457	(stopped/continued).
428		458
…		…
450	thing in an AnyEvent program, you I<have> to create at least one	480	thing in an AnyEvent program, you I<have> to create at least one
451	watcher before you C<fork> the child (alternatively, you can call	481	watcher before you C<fork> the child (alternatively, you can call
452	C<AnyEvent::detect>).	482	C<AnyEvent::detect>).
453		483
454	As most event loops do not support waiting for child events, they will be	484	As most event loops do not support waiting for child events, they will be
455	emulated by AnyEvent in most cases, in which the latency and race problems	485	emulated by AnyEvent in most cases, in which case the latency and race
456	mentioned in the description of signal watchers apply.	486	problems mentioned in the description of signal watchers apply.
457		487
458	Example: fork a process and wait for it	488	Example: fork a process and wait for it
459		489
460	my $done = AnyEvent->condvar;	490	my $done = AnyEvent->condvar;
461		491
…		…
475		505
476	=head2 IDLE WATCHERS	506	=head2 IDLE WATCHERS
477		507
478	$w = AnyEvent->idle (cb => <callback>);	508	$w = AnyEvent->idle (cb => <callback>);
479		509
480	Sometimes there is a need to do something, but it is not so important	510	This will repeatedly invoke the callback after the process becomes idle,
481	to do it instantly, but only when there is nothing better to do. This	511	until either the watcher is destroyed or new events have been detected.
482	"nothing better to do" is usually defined to be "no other events need
483	attention by the event loop".
484		512
485	Idle watchers ideally get invoked when the event loop has nothing	513	Idle watchers are useful when there is a need to do something, but it
486	better to do, just before it would block the process to wait for new	514	is not so important (or wise) to do it instantly. The callback will be
487	events. Instead of blocking, the idle watcher is invoked.	515	invoked only when there is "nothing better to do", which is usually
		516	defined as "all outstanding events have been handled and no new events
		517	have been detected". That means that idle watchers ideally get invoked
		518	when the event loop has just polled for new events but none have been
		519	detected. Instead of blocking to wait for more events, the idle watchers
		520	will be invoked.
488		521
489	Most event loops unfortunately do not really support idle watchers (only	522	Unfortunately, most event loops do not really support idle watchers (only
490	EV, Event and Glib do it in a usable fashion) - for the rest, AnyEvent	523	EV, Event and Glib do it in a usable fashion) - for the rest, AnyEvent
491	will simply call the callback "from time to time".	524	will simply call the callback "from time to time".
492		525
493	Example: read lines from STDIN, but only process them when the	526	Example: read lines from STDIN, but only process them when the
494	program is otherwise idle:	527	program is otherwise idle:
…		…
522	will actively watch for new events and call your callbacks.	555	will actively watch for new events and call your callbacks.
523		556
524	AnyEvent is slightly different: it expects somebody else to run the event	557	AnyEvent is slightly different: it expects somebody else to run the event
525	loop and will only block when necessary (usually when told by the user).	558	loop and will only block when necessary (usually when told by the user).
526		559
527	The instrument to do that is called a "condition variable", so called	560	The tool to do that is called a "condition variable", so called because
528	because they represent a condition that must become true.	561	they represent a condition that must become true.
529		562
530	Now is probably a good time to look at the examples further below.	563	Now is probably a good time to look at the examples further below.
531		564
532	Condition variables can be created by calling the C<< AnyEvent->condvar	565	Condition variables can be created by calling the C<< AnyEvent->condvar
533	>> method, usually without arguments. The only argument pair allowed is	566	>> method, usually without arguments. The only argument pair allowed is
…		…
538	After creation, the condition variable is "false" until it becomes "true"	571	After creation, the condition variable is "false" until it becomes "true"
539	by calling the C<send> method (or calling the condition variable as if it	572	by calling the C<send> method (or calling the condition variable as if it
540	were a callback, read about the caveats in the description for the C<<	573	were a callback, read about the caveats in the description for the C<<
541	->send >> method).	574	->send >> method).
542		575
543	Condition variables are similar to callbacks, except that you can	576	Since condition variables are the most complex part of the AnyEvent API, here are
544	optionally wait for them. They can also be called merge points - points	577	some different mental models of what they are - pick the ones you can connect to:
545	in time where multiple outstanding events have been processed. And yet	578
546	another way to call them is transactions - each condition variable can be	579	=over 4
547	used to represent a transaction, which finishes at some point and delivers	580
548	a result. And yet some people know them as "futures" - a promise to	581	=item * Condition variables are like callbacks - you can call them (and pass them instead
549	compute/deliver something that you can wait for.	582	of callbacks). Unlike callbacks however, you can also wait for them to be called.
		583
		584	=item * Condition variables are signals - one side can emit or send them,
		585	the other side can wait for them, or install a handler that is called when
		586	the signal fires.
		587
		588	=item * Condition variables are like "Merge Points" - points in your program
		589	where you merge multiple independent results/control flows into one.
		590
		591	=item * Condition variables represent a transaction - functions that start
		592	some kind of transaction can return them, leaving the caller the choice
		593	between waiting in a blocking fashion, or setting a callback.
		594
		595	=item * Condition variables represent future values, or promises to deliver
		596	some result, long before the result is available.
		597
		598	=back
550		599
551	Condition variables are very useful to signal that something has finished,	600	Condition variables are very useful to signal that something has finished,
552	for example, if you write a module that does asynchronous http requests,	601	for example, if you write a module that does asynchronous http requests,
553	then a condition variable would be the ideal candidate to signal the	602	then a condition variable would be the ideal candidate to signal the
554	availability of results. The user can either act when the callback is	603	availability of results. The user can either act when the callback is
…		…
567		616
568	Condition variables are represented by hash refs in perl, and the keys	617	Condition variables are represented by hash refs in perl, and the keys
569	used by AnyEvent itself are all named C<_ae_XXX> to make subclassing	618	used by AnyEvent itself are all named C<_ae_XXX> to make subclassing
570	easy (it is often useful to build your own transaction class on top of	619	easy (it is often useful to build your own transaction class on top of
571	AnyEvent). To subclass, use C<AnyEvent::CondVar> as base class and call	620	AnyEvent). To subclass, use C<AnyEvent::CondVar> as base class and call
572	it's C<new> method in your own C<new> method.	621	its C<new> method in your own C<new> method.
573		622
574	There are two "sides" to a condition variable - the "producer side" which	623	There are two "sides" to a condition variable - the "producer side" which
575	eventually calls C<< -> send >>, and the "consumer side", which waits	624	eventually calls C<< -> send >>, and the "consumer side", which waits
576	for the send to occur.	625	for the send to occur.
577		626
578	Example: wait for a timer.	627	Example: wait for a timer.
579		628
580	# wait till the result is ready	629	# condition: "wait till the timer is fired"
581	my $result_ready = AnyEvent->condvar;	630	my $timer_fired = AnyEvent->condvar;
582		631
583	# do something such as adding a timer	632	# create the timer - we could wait for, say
584	# or socket watcher the calls $result_ready->send	633	# a handle becomign ready, or even an
585	# when the "result" is ready.	634	# AnyEvent::HTTP request to finish, but
586	# in this case, we simply use a timer:	635	# in this case, we simply use a timer:
587	my $w = AnyEvent->timer (	636	my $w = AnyEvent->timer (
588	after => 1,	637	after => 1,
589	cb => sub { $result_ready->send },	638	cb => sub { $timer_fired->send },
590	);	639	);
591		640
592	# this "blocks" (while handling events) till the callback	641	# this "blocks" (while handling events) till the callback
593	# calls -<send	642	# calls ->send
594	$result_ready->recv;	643	$timer_fired->recv;
595		644
596	Example: wait for a timer, but take advantage of the fact that condition	645	Example: wait for a timer, but take advantage of the fact that condition
597	variables are also callable directly.	646	variables are also callable directly.
598		647
599	my $done = AnyEvent->condvar;	648	my $done = AnyEvent->condvar;
…		…
642	they were a code reference). Calling them directly is the same as calling	691	they were a code reference). Calling them directly is the same as calling
643	C<send>.	692	C<send>.
644		693
645	=item $cv->croak ($error)	694	=item $cv->croak ($error)
646		695
647	Similar to send, but causes all call's to C<< ->recv >> to invoke	696	Similar to send, but causes all calls to C<< ->recv >> to invoke
648	C<Carp::croak> with the given error message/object/scalar.	697	C<Carp::croak> with the given error message/object/scalar.
649		698
650	This can be used to signal any errors to the condition variable	699	This can be used to signal any errors to the condition variable
651	user/consumer. Doing it this way instead of calling C<croak> directly	700	user/consumer. Doing it this way instead of calling C<croak> directly
652	delays the error detetcion, but has the overwhelmign advantage that it	701	delays the error detection, but has the overwhelming advantage that it
653	diagnoses the error at the place where the result is expected, and not	702	diagnoses the error at the place where the result is expected, and not
654	deep in some event clalback without connection to the actual code causing	703	deep in some event callback with no connection to the actual code causing
655	the problem.	704	the problem.
656		705
657	=item $cv->begin ([group callback])	706	=item $cv->begin ([group callback])
658		707
659	=item $cv->end	708	=item $cv->end
…		…
662	one. For example, a function that pings many hosts in parallel might want	711	one. For example, a function that pings many hosts in parallel might want
663	to use a condition variable for the whole process.	712	to use a condition variable for the whole process.
664		713
665	Every call to C<< ->begin >> will increment a counter, and every call to	714	Every call to C<< ->begin >> will increment a counter, and every call to
666	C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end	715	C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end
667	>>, the (last) callback passed to C<begin> will be executed. That callback	716	>>, the (last) callback passed to C<begin> will be executed, passing the
668	is I<supposed> to call C<< ->send >>, but that is not required. If no	717	condvar as first argument. That callback is I<supposed> to call C<< ->send
669	callback was set, C<send> will be called without any arguments.	718	>>, but that is not required. If no group callback was set, C<send> will
		719	be called without any arguments.
670		720
671	You can think of C<< $cv->send >> giving you an OR condition (one call	721	You can think of C<< $cv->send >> giving you an OR condition (one call
672	sends), while C<< $cv->begin >> and C<< $cv->end >> giving you an AND	722	sends), while C<< $cv->begin >> and C<< $cv->end >> giving you an AND
673	condition (all C<begin> calls must be C<end>'ed before the condvar sends).	723	condition (all C<begin> calls must be C<end>'ed before the condvar sends).
674		724
…		…
696	one call to C<begin>, so the condvar waits for all calls to C<end> before	746	one call to C<begin>, so the condvar waits for all calls to C<end> before
697	sending.	747	sending.
698		748
699	The ping example mentioned above is slightly more complicated, as the	749	The ping example mentioned above is slightly more complicated, as the
700	there are results to be passwd back, and the number of tasks that are	750	there are results to be passwd back, and the number of tasks that are
701	begung can potentially be zero:	751	begun can potentially be zero:
702		752
703	my $cv = AnyEvent->condvar;	753	my $cv = AnyEvent->condvar;
704		754
705	my %result;	755	my %result;
706	$cv->begin (sub { $cv->send (\%result) });	756	$cv->begin (sub { shift->send (\%result) });
707		757
708	for my $host (@list_of_hosts) {	758	for my $host (@list_of_hosts) {
709	$cv->begin;	759	$cv->begin;
710	ping_host_then_call_callback $host, sub {	760	ping_host_then_call_callback $host, sub {
711	$result{$host} = ...;	761	$result{$host} = ...;
…		…
727	to be called once the counter reaches C<0>, and second, it ensures that	777	to be called once the counter reaches C<0>, and second, it ensures that
728	C<send> is called even when C<no> hosts are being pinged (the loop	778	C<send> is called even when C<no> hosts are being pinged (the loop
729	doesn't execute once).	779	doesn't execute once).
730		780
731	This is the general pattern when you "fan out" into multiple (but	781	This is the general pattern when you "fan out" into multiple (but
732	potentially none) subrequests: use an outer C<begin>/C<end> pair to set	782	potentially zero) subrequests: use an outer C<begin>/C<end> pair to set
733	the callback and ensure C<end> is called at least once, and then, for each	783	the callback and ensure C<end> is called at least once, and then, for each
734	subrequest you start, call C<begin> and for each subrequest you finish,	784	subrequest you start, call C<begin> and for each subrequest you finish,
735	call C<end>.	785	call C<end>.
736		786
737	=back	787	=back
…		…
744	=over 4	794	=over 4
745		795
746	=item $cv->recv	796	=item $cv->recv
747		797
748	Wait (blocking if necessary) until the C<< ->send >> or C<< ->croak	798	Wait (blocking if necessary) until the C<< ->send >> or C<< ->croak
749	>> methods have been called on c<$cv>, while servicing other watchers	799	>> methods have been called on C<$cv>, while servicing other watchers
750	normally.	800	normally.
751		801
752	You can only wait once on a condition - additional calls are valid but	802	You can only wait once on a condition - additional calls are valid but
753	will return immediately.	803	will return immediately.
754		804
…		…
771	caller decide whether the call will block or not (for example, by coupling	821	caller decide whether the call will block or not (for example, by coupling
772	condition variables with some kind of request results and supporting	822	condition variables with some kind of request results and supporting
773	callbacks so the caller knows that getting the result will not block,	823	callbacks so the caller knows that getting the result will not block,
774	while still supporting blocking waits if the caller so desires).	824	while still supporting blocking waits if the caller so desires).
775		825
776	You can ensure that C<< -recv >> never blocks by setting a callback and	826	You can ensure that C<< ->recv >> never blocks by setting a callback and
777	only calling C<< ->recv >> from within that callback (or at a later	827	only calling C<< ->recv >> from within that callback (or at a later
778	time). This will work even when the event loop does not support blocking	828	time). This will work even when the event loop does not support blocking
779	waits otherwise.	829	waits otherwise.
780		830
781	=item $bool = $cv->ready	831	=item $bool = $cv->ready
…		…
787		837
788	This is a mutator function that returns the callback set and optionally	838	This is a mutator function that returns the callback set and optionally
789	replaces it before doing so.	839	replaces it before doing so.
790		840
791	The callback will be called when the condition becomes "true", i.e. when	841	The callback will be called when the condition becomes "true", i.e. when
792	C<send> or C<croak> are called, with the only argument being the condition	842	C<send> or C<croak> are called, with the only argument being the
793	variable itself. Calling C<recv> inside the callback or at any later time	843	condition variable itself. If the condition is already true, the
794	is guaranteed not to block.	844	callback is called immediately when it is set. Calling C<recv> inside
		845	the callback or at any later time is guaranteed not to block.
795		846
796	=back	847	=back
797		848
798	=head1 SUPPORTED EVENT LOOPS/BACKENDS	849	=head1 SUPPORTED EVENT LOOPS/BACKENDS
799		850
…		…
802	=over 4	853	=over 4
803		854
804	=item Backends that are autoprobed when no other event loop can be found.	855	=item Backends that are autoprobed when no other event loop can be found.
805		856
806	EV is the preferred backend when no other event loop seems to be in	857	EV is the preferred backend when no other event loop seems to be in
807	use. If EV is not installed, then AnyEvent will try Event, and, failing	858	use. If EV is not installed, then AnyEvent will fall back to its own
808	that, will fall back to its own pure-perl implementation, which is	859	pure-perl implementation, which is available everywhere as it comes with
809	available everywhere as it comes with AnyEvent itself.	860	AnyEvent itself.
810		861
811	AnyEvent::Impl::EV based on EV (interface to libev, best choice).	862	AnyEvent::Impl::EV based on EV (interface to libev, best choice).
812	AnyEvent::Impl::Event based on Event, very stable, few glitches.
813	AnyEvent::Impl::Perl pure-perl implementation, fast and portable.	863	AnyEvent::Impl::Perl pure-perl AnyEvent::Loop, fast and portable.
814		864
815	=item Backends that are transparently being picked up when they are used.	865	=item Backends that are transparently being picked up when they are used.
816		866
817	These will be used when they are currently loaded when the first watcher	867	These will be used if they are already loaded when the first watcher
818	is created, in which case it is assumed that the application is using	868	is created, in which case it is assumed that the application is using
819	them. This means that AnyEvent will automatically pick the right backend	869	them. This means that AnyEvent will automatically pick the right backend
820	when the main program loads an event module before anything starts to	870	when the main program loads an event module before anything starts to
821	create watchers. Nothing special needs to be done by the main program.	871	create watchers. Nothing special needs to be done by the main program.
822		872
		873	AnyEvent::Impl::Event based on Event, very stable, few glitches.
823	AnyEvent::Impl::Glib based on Glib, slow but very stable.	874	AnyEvent::Impl::Glib based on Glib, slow but very stable.
824	AnyEvent::Impl::Tk based on Tk, very broken.	875	AnyEvent::Impl::Tk based on Tk, very broken.
825	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.	876	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
826	AnyEvent::Impl::POE based on POE, very slow, some limitations.	877	AnyEvent::Impl::POE based on POE, very slow, some limitations.
827	AnyEvent::Impl::Irssi used when running within irssi.	878	AnyEvent::Impl::Irssi used when running within irssi.
		879	AnyEvent::Impl::IOAsync based on IO::Async.
		880	AnyEvent::Impl::Cocoa based on Cocoa::EventLoop.
		881	AnyEvent::Impl::FLTK based on FLTK (fltk 2 binding).
828		882
829	=item Backends with special needs.	883	=item Backends with special needs.
830		884
831	Qt requires the Qt::Application to be instantiated first, but will	885	Qt requires the Qt::Application to be instantiated first, but will
832	otherwise be picked up automatically. As long as the main program	886	otherwise be picked up automatically. As long as the main program
833	instantiates the application before any AnyEvent watchers are created,	887	instantiates the application before any AnyEvent watchers are created,
834	everything should just work.	888	everything should just work.
835		889
836	AnyEvent::Impl::Qt based on Qt.	890	AnyEvent::Impl::Qt based on Qt.
837		891
838	Support for IO::Async can only be partial, as it is too broken and
839	architecturally limited to even support the AnyEvent API. It also
840	is the only event loop that needs the loop to be set explicitly, so
841	it can only be used by a main program knowing about AnyEvent. See
842	L<AnyEvent::Impl::Async> for the gory details.
843
844	AnyEvent::Impl::IOAsync based on IO::Async, cannot be autoprobed.
845
846	=item Event loops that are indirectly supported via other backends.	892	=item Event loops that are indirectly supported via other backends.
847		893
848	Some event loops can be supported via other modules:	894	Some event loops can be supported via other modules:
849		895
850	There is no direct support for WxWidgets (L<Wx>) or L<Prima>.	896	There is no direct support for WxWidgets (L<Wx>) or L<Prima>.
…		…
875	Contains C<undef> until the first watcher is being created, before the	921	Contains C<undef> until the first watcher is being created, before the
876	backend has been autodetected.	922	backend has been autodetected.
877		923
878	Afterwards it contains the event model that is being used, which is the	924	Afterwards it contains the event model that is being used, which is the
879	name of the Perl class implementing the model. This class is usually one	925	name of the Perl class implementing the model. This class is usually one
880	of the C<AnyEvent::Impl:xxx> modules, but can be any other class in the	926	of the C<AnyEvent::Impl::xxx> modules, but can be any other class in the
881	case AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode> it	927	case AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode> it
882	will be C<urxvt::anyevent>).	928	will be C<urxvt::anyevent>).
883		929
884	=item AnyEvent::detect	930	=item AnyEvent::detect
885		931
886	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model	932	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model
887	if necessary. You should only call this function right before you would	933	if necessary. You should only call this function right before you would
888	have created an AnyEvent watcher anyway, that is, as late as possible at	934	have created an AnyEvent watcher anyway, that is, as late as possible at
889	runtime, and not e.g. while initialising of your module.	935	runtime, and not e.g. during initialisation of your module.
		936
		937	The effect of calling this function is as if a watcher had been created
		938	(specifically, actions that happen "when the first watcher is created"
		939	happen when calling detetc as well).
890		940
891	If you need to do some initialisation before AnyEvent watchers are	941	If you need to do some initialisation before AnyEvent watchers are
892	created, use C<post_detect>.	942	created, use C<post_detect>.
893		943
894	=item $guard = AnyEvent::post_detect { BLOCK }	944	=item $guard = AnyEvent::post_detect { BLOCK }
895		945
896	Arranges for the code block to be executed as soon as the event model is	946	Arranges for the code block to be executed as soon as the event model is
897	autodetected (or immediately if this has already happened).	947	autodetected (or immediately if that has already happened).
898		948
899	The block will be executed I<after> the actual backend has been detected	949	The block will be executed I<after> the actual backend has been detected
900	(C<$AnyEvent::MODEL> is set), but I<before> any watchers have been	950	(C<$AnyEvent::MODEL> is set), but I<before> any watchers have been
901	created, so it is possible to e.g. patch C<@AnyEvent::ISA> or do	951	created, so it is possible to e.g. patch C<@AnyEvent::ISA> or do
902	other initialisations - see the sources of L<AnyEvent::Strict> or	952	other initialisations - see the sources of L<AnyEvent::Strict> or
…		…
911	that automatically removes the callback again when it is destroyed (or	961	that automatically removes the callback again when it is destroyed (or
912	C<undef> when the hook was immediately executed). See L<AnyEvent::AIO> for	962	C<undef> when the hook was immediately executed). See L<AnyEvent::AIO> for
913	a case where this is useful.	963	a case where this is useful.
914		964
915	Example: Create a watcher for the IO::AIO module and store it in	965	Example: Create a watcher for the IO::AIO module and store it in
916	C<$WATCHER>. Only do so after the event loop is initialised, though.	966	C<$WATCHER>, but do so only do so after the event loop is initialised.
917		967
918	our WATCHER;	968	our WATCHER;
919		969
920	my $guard = AnyEvent::post_detect {	970	my $guard = AnyEvent::post_detect {
921	$WATCHER = AnyEvent->io (fh => IO::AIO::poll_fileno, poll => 'r', cb => \&IO::AIO::poll_cb);	971	$WATCHER = AnyEvent->io (fh => IO::AIO::poll_fileno, poll => 'r', cb => \&IO::AIO::poll_cb);
…		…
929	$WATCHER ||= $guard;	979	$WATCHER ||= $guard;
930		980
931	=item @AnyEvent::post_detect	981	=item @AnyEvent::post_detect
932		982
933	If there are any code references in this array (you can C<push> to it	983	If there are any code references in this array (you can C<push> to it
934	before or after loading AnyEvent), then they will called directly after	984	before or after loading AnyEvent), then they will be called directly
935	the event loop has been chosen.	985	after the event loop has been chosen.
936		986
937	You should check C<$AnyEvent::MODEL> before adding to this array, though:	987	You should check C<$AnyEvent::MODEL> before adding to this array, though:
938	if it is defined then the event loop has already been detected, and the	988	if it is defined then the event loop has already been detected, and the
939	array will be ignored.	989	array will be ignored.
940		990
941	Best use C<AnyEvent::post_detect { BLOCK }> when your application allows	991	Best use C<AnyEvent::post_detect { BLOCK }> when your application allows
942	it,as it takes care of these details.	992	it, as it takes care of these details.
943		993
944	This variable is mainly useful for modules that can do something useful	994	This variable is mainly useful for modules that can do something useful
945	when AnyEvent is used and thus want to know when it is initialised, but do	995	when AnyEvent is used and thus want to know when it is initialised, but do
946	not need to even load it by default. This array provides the means to hook	996	not need to even load it by default. This array provides the means to hook
947	into AnyEvent passively, without loading it.	997	into AnyEvent passively, without loading it.
948		998
		999	Example: To load Coro::AnyEvent whenever Coro and AnyEvent are used
		1000	together, you could put this into Coro (this is the actual code used by
		1001	Coro to accomplish this):
		1002
		1003	if (defined $AnyEvent::MODEL) {
		1004	# AnyEvent already initialised, so load Coro::AnyEvent
		1005	require Coro::AnyEvent;
		1006	} else {
		1007	# AnyEvent not yet initialised, so make sure to load Coro::AnyEvent
		1008	# as soon as it is
		1009	push @AnyEvent::post_detect, sub { require Coro::AnyEvent };
		1010	}
		1011
		1012	=item AnyEvent::postpone { BLOCK }
		1013
		1014	Arranges for the block to be executed as soon as possible, but not before
		1015	the call itself returns. In practise, the block will be executed just
		1016	before the event loop polls for new events, or shortly afterwards.
		1017
		1018	This function never returns anything (to make the C<return postpone { ...
		1019	}> idiom more useful.
		1020
		1021	To understand the usefulness of this function, consider a function that
		1022	asynchronously does something for you and returns some transaction
		1023	object or guard to let you cancel the operation. For example,
		1024	C<AnyEvent::Socket::tcp_connect>:
		1025
		1026	# start a conenction attempt unless one is active
		1027	$self->{connect_guard} ||= AnyEvent::Socket::tcp_connect "www.example.net", 80, sub {
		1028	delete $self->{connect_guard};
		1029	...
		1030	};
		1031
		1032	Imagine that this function could instantly call the callback, for
		1033	example, because it detects an obvious error such as a negative port
		1034	number. Invoking the callback before the function returns causes problems
		1035	however: the callback will be called and will try to delete the guard
		1036	object. But since the function hasn't returned yet, there is nothing to
		1037	delete. When the function eventually returns it will assign the guard
		1038	object to C<< $self->{connect_guard} >>, where it will likely never be
		1039	deleted, so the program thinks it is still trying to connect.
		1040
		1041	This is where C<AnyEvent::postpone> should be used. Instead of calling the
		1042	callback directly on error:
		1043
		1044	$cb->(undef), return # signal error to callback, BAD!
		1045	if $some_error_condition;
		1046
		1047	It should use C<postpone>:
		1048
		1049	AnyEvent::postpone { $cb->(undef) }, return # signal error to callback, later
		1050	if $some_error_condition;
		1051
		1052	=item AnyEvent::log $level, $msg[, @args]
		1053
		1054	Log the given C<$msg> at the given C<$level>.
		1055
		1056	If L<AnyEvent::Log> is not loaded then this function makes a simple test
		1057	to see whether the message will be logged. If the test succeeds it will
		1058	load AnyEvent::Log and call C<AnyEvent::Log::log> - consequently, look at
		1059	the L<AnyEvent::Log> documentation for details.
		1060
		1061	If the test fails it will simply return. Right now this happens when a
		1062	numerical loglevel is used and it is larger than the level specified via
		1063	C<$ENV{PERL_ANYEVENT_VERBOSE}>.
		1064
		1065	If you want to sprinkle loads of logging calls around your code, consider
		1066	creating a logger callback with the C<AnyEvent::Log::logger> function,
		1067	which can reduce typing, codesize and can reduce the logging overhead
		1068	enourmously.
		1069
949	=back	1070	=back
950		1071
951	=head1 WHAT TO DO IN A MODULE	1072	=head1 WHAT TO DO IN A MODULE
952		1073
953	As a module author, you should C<use AnyEvent> and call AnyEvent methods	1074	As a module author, you should C<use AnyEvent> and call AnyEvent methods
…		…
963	because it will stall the whole program, and the whole point of using	1084	because it will stall the whole program, and the whole point of using
964	events is to stay interactive.	1085	events is to stay interactive.
965		1086
966	It is fine, however, to call C<< ->recv >> when the user of your module	1087	It is fine, however, to call C<< ->recv >> when the user of your module
967	requests it (i.e. if you create a http request object ad have a method	1088	requests it (i.e. if you create a http request object ad have a method
968	called C<results> that returns the results, it should call C<< ->recv >>	1089	called C<results> that returns the results, it may call C<< ->recv >>
969	freely, as the user of your module knows what she is doing. always).	1090	freely, as the user of your module knows what she is doing. Always).
970		1091
971	=head1 WHAT TO DO IN THE MAIN PROGRAM	1092	=head1 WHAT TO DO IN THE MAIN PROGRAM
972		1093
973	There will always be a single main program - the only place that should	1094	There will always be a single main program - the only place that should
974	dictate which event model to use.	1095	dictate which event model to use.
975		1096
976	If it doesn't care, it can just "use AnyEvent" and use it itself, or not	1097	If the program is not event-based, it need not do anything special, even
977	do anything special (it does not need to be event-based) and let AnyEvent	1098	when it depends on a module that uses an AnyEvent. If the program itself
978	decide which implementation to chose if some module relies on it.	1099	uses AnyEvent, but does not care which event loop is used, all it needs
		1100	to do is C<use AnyEvent>. In either case, AnyEvent will choose the best
		1101	available loop implementation.
979		1102
980	If the main program relies on a specific event model - for example, in	1103	If the main program relies on a specific event model - for example, in
981	Gtk2 programs you have to rely on the Glib module - you should load the	1104	Gtk2 programs you have to rely on the Glib module - you should load the
982	event module before loading AnyEvent or any module that uses it: generally	1105	event module before loading AnyEvent or any module that uses it: generally
983	speaking, you should load it as early as possible. The reason is that	1106	speaking, you should load it as early as possible. The reason is that
984	modules might create watchers when they are loaded, and AnyEvent will	1107	modules might create watchers when they are loaded, and AnyEvent will
985	decide on the event model to use as soon as it creates watchers, and it	1108	decide on the event model to use as soon as it creates watchers, and it
986	might chose the wrong one unless you load the correct one yourself.	1109	might choose the wrong one unless you load the correct one yourself.
987		1110
988	You can chose to use a pure-perl implementation by loading the	1111	You can chose to use a pure-perl implementation by loading the
989	C<AnyEvent::Impl::Perl> module, which gives you similar behaviour	1112	C<AnyEvent::Loop> module, which gives you similar behaviour
990	everywhere, but letting AnyEvent chose the model is generally better.	1113	everywhere, but letting AnyEvent chose the model is generally better.
991		1114
992	=head2 MAINLOOP EMULATION	1115	=head2 MAINLOOP EMULATION
993		1116
994	Sometimes (often for short test scripts, or even standalone programs who	1117	Sometimes (often for short test scripts, or even standalone programs who
…		…
1007		1130
1008		1131
1009	=head1 OTHER MODULES	1132	=head1 OTHER MODULES
1010		1133
1011	The following is a non-exhaustive list of additional modules that use	1134	The following is a non-exhaustive list of additional modules that use
1012	AnyEvent as a client and can therefore be mixed easily with other AnyEvent	1135	AnyEvent as a client and can therefore be mixed easily with other
1013	modules and other event loops in the same program. Some of the modules	1136	AnyEvent modules and other event loops in the same program. Some of the
1014	come with AnyEvent, most are available via CPAN.	1137	modules come as part of AnyEvent, the others are available via CPAN (see
		1138	L<http://search.cpan.org/search?m=module&q=anyevent%3A%3A*> for
		1139	a longer non-exhaustive list), and the list is heavily biased towards
		1140	modules of the AnyEvent author himself :)
1015		1141
1016	=over 4	1142	=over 4
1017		1143
1018	=item L<AnyEvent::Util>	1144	=item L<AnyEvent::Util>
1019		1145
1020	Contains various utility functions that replace often-used but blocking	1146	Contains various utility functions that replace often-used blocking
1021	functions such as C<inet_aton> by event-/callback-based versions.	1147	functions such as C<inet_aton> with event/callback-based versions.
1022		1148
1023	=item L<AnyEvent::Socket>	1149	=item L<AnyEvent::Socket>
1024		1150
1025	Provides various utility functions for (internet protocol) sockets,	1151	Provides various utility functions for (internet protocol) sockets,
1026	addresses and name resolution. Also functions to create non-blocking tcp	1152	addresses and name resolution. Also functions to create non-blocking tcp
…		…
1028		1154
1029	=item L<AnyEvent::Handle>	1155	=item L<AnyEvent::Handle>
1030		1156
1031	Provide read and write buffers, manages watchers for reads and writes,	1157	Provide read and write buffers, manages watchers for reads and writes,
1032	supports raw and formatted I/O, I/O queued and fully transparent and	1158	supports raw and formatted I/O, I/O queued and fully transparent and
1033	non-blocking SSL/TLS (via L<AnyEvent::TLS>.	1159	non-blocking SSL/TLS (via L<AnyEvent::TLS>).
1034		1160
1035	=item L<AnyEvent::DNS>	1161	=item L<AnyEvent::DNS>
1036		1162
1037	Provides rich asynchronous DNS resolver capabilities.	1163	Provides rich asynchronous DNS resolver capabilities.
1038		1164
		1165	=item L<AnyEvent::HTTP>, L<AnyEvent::IRC>, L<AnyEvent::XMPP>, L<AnyEvent::GPSD>, L<AnyEvent::IGS>, L<AnyEvent::FCP>
		1166
		1167	Implement event-based interfaces to the protocols of the same name (for
		1168	the curious, IGS is the International Go Server and FCP is the Freenet
		1169	Client Protocol).
		1170
1039	=item L<AnyEvent::HTTP>	1171	=item L<AnyEvent::AIO>
1040		1172
1041	A simple-to-use HTTP library that is capable of making a lot of concurrent	1173	Truly asynchronous (as opposed to non-blocking) I/O, should be in the
1042	HTTP requests.	1174	toolbox of every event programmer. AnyEvent::AIO transparently fuses
		1175	L<IO::AIO> and AnyEvent together, giving AnyEvent access to event-based
		1176	file I/O, and much more.
		1177
		1178	=item L<AnyEvent::Filesys::Notify>
		1179
		1180	AnyEvent is good for non-blocking stuff, but it can't detect file or
		1181	path changes (e.g. "watch this directory for new files", "watch this
		1182	file for changes"). The L<AnyEvent::Filesys::Notify> module promises to
		1183	do just that in a portbale fashion, supporting inotify on GNU/Linux and
		1184	some weird, without doubt broken, stuff on OS X to monitor files. It can
		1185	fall back to blocking scans at regular intervals transparently on other
		1186	platforms, so it's about as portable as it gets.
		1187
		1188	(I haven't used it myself, but I haven't heard anybody complaining about
		1189	it yet).
		1190
		1191	=item L<AnyEvent::DBI>
		1192
		1193	Executes L<DBI> requests asynchronously in a proxy process for you,
		1194	notifying you in an event-based way when the operation is finished.
1043		1195
1044	=item L<AnyEvent::HTTPD>	1196	=item L<AnyEvent::HTTPD>
1045		1197
1046	Provides a simple web application server framework.	1198	A simple embedded webserver.
1047		1199
1048	=item L<AnyEvent::FastPing>	1200	=item L<AnyEvent::FastPing>
1049		1201
1050	The fastest ping in the west.	1202	The fastest ping in the west.
1051		1203
1052	=item L<AnyEvent::DBI>
1053
1054	Executes L<DBI> requests asynchronously in a proxy process.
1055
1056	=item L<AnyEvent::AIO>
1057
1058	Truly asynchronous I/O, should be in the toolbox of every event
1059	programmer. AnyEvent::AIO transparently fuses L<IO::AIO> and AnyEvent
1060	together.
1061
1062	=item L<AnyEvent::BDB>
1063
1064	Truly asynchronous Berkeley DB access. AnyEvent::BDB transparently fuses
1065	L<BDB> and AnyEvent together.
1066
1067	=item L<AnyEvent::GPSD>
1068
1069	A non-blocking interface to gpsd, a daemon delivering GPS information.
1070
1071	=item L<AnyEvent::IRC>
1072
1073	AnyEvent based IRC client module family (replacing the older Net::IRC3).
1074
1075	=item L<AnyEvent::XMPP>
1076
1077	AnyEvent based XMPP (Jabber protocol) module family (replacing the older
1078	Net::XMPP2>.
1079
1080	=item L<AnyEvent::IGS>
1081
1082	A non-blocking interface to the Internet Go Server protocol (used by
1083	L<App::IGS>).
1084
1085	=item L<Net::FCP>
1086
1087	AnyEvent-based implementation of the Freenet Client Protocol, birthplace
1088	of AnyEvent.
1089
1090	=item L<Event::ExecFlow>
1091
1092	High level API for event-based execution flow control.
1093
1094	=item L<Coro>	1204	=item L<Coro>
1095		1205
1096	Has special support for AnyEvent via L<Coro::AnyEvent>.	1206	Has special support for AnyEvent via L<Coro::AnyEvent>, which allows you
		1207	to simply invert the flow control - don't call us, we will call you:
		1208
		1209	async {
		1210	Coro::AnyEvent::sleep 5; # creates a 5s timer and waits for it
		1211	print "5 seconds later!\n";
		1212
		1213	Coro::AnyEvent::readable *STDIN; # uses an I/O watcher
		1214	my $line = <STDIN>; # works for ttys
		1215
		1216	AnyEvent::HTTP::http_get "url", Coro::rouse_cb;
		1217	my ($body, $hdr) = Coro::rouse_wait;
		1218	};
1097		1219
1098	=back	1220	=back
1099		1221
1100	=cut	1222	=cut
1101		1223
1102	package AnyEvent;	1224	package AnyEvent;
1103		1225
1104	# basically a tuned-down version of common::sense	1226	# basically a tuned-down version of common::sense
1105	sub common_sense {	1227	sub common_sense {
1106	# no warnings	1228	# from common:.sense 3.4
1107	${^WARNING_BITS} ^= ${^WARNING_BITS};	1229	${^WARNING_BITS} ^= ${^WARNING_BITS} ^ "\x3c\x3f\x33\x00\x0f\xf0\x0f\xc0\xf0\xfc\x33\x00";
1108	# use strict vars subs	1230	# use strict vars subs - NO UTF-8, as Util.pm doesn't like this atm. (uts46data.pl)
1109	$^H |= 0x00000600;	1231	$^H |= 0x00000600;
1110	}	1232	}
1111		1233
1112	BEGIN { AnyEvent::common_sense }	1234	BEGIN { AnyEvent::common_sense }
1113		1235
1114	use Carp ();	1236	use Carp ();
1115		1237
1116	our $VERSION = 4.881;	1238	our $VERSION = '6.02';
1117	our $MODEL;	1239	our $MODEL;
1118
1119	our $AUTOLOAD;
1120	our @ISA;	1240	our @ISA;
1121
1122	our @REGISTRY;	1241	our @REGISTRY;
1123
1124	our $WIN32;
1125
1126	our $VERBOSE;	1242	our $VERBOSE;
		1243	our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred
		1244	our $MAX_SIGNAL_LATENCY = $ENV{PERL_ANYEVENT_MAX_SIGNAL_LATENCY} || 10; # executes after the BEGIN block below (tainting!)
1127		1245
1128	BEGIN {	1246	BEGIN {
1129	eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }";	1247	require "AnyEvent/constants.pl";
		1248
1130	eval "sub TAINT(){ " . (${^TAINT}*1) . " }";	1249	eval "sub TAINT (){" . (${^TAINT}*1) . "}";
1131		1250
1132	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}	1251	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}
1133	if ${^TAINT};	1252	if ${^TAINT};
1134		1253
1135	$VERBOSE = $ENV{PERL_ANYEVENT_VERBOSE}*1;	1254	$ENV{"PERL_ANYEVENT_$_"} = $ENV{"AE_$_"}
		1255	for grep s/^AE_// && !exists $ENV{"PERL_ANYEVENT_$_"}, keys %ENV;
1136		1256
1137	}	1257	@ENV{grep /^PERL_ANYEVENT_/, keys %ENV} = ()
		1258	if ${^TAINT};
1138		1259
1139	our $MAX_SIGNAL_LATENCY = 10;	1260	# $ENV{PERL_ANYEVENT_xxx} now valid
1140		1261
1141	our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred	1262	$VERBOSE = length $ENV{PERL_ANYEVENT_VERBOSE} ? $ENV{PERL_ANYEVENT_VERBOSE}*1 : 4;
1142		1263
1143	{
1144	my $idx;	1264	my $idx;
1145	$PROTOCOL{$_} = ++$idx	1265	$PROTOCOL{$_} = ++$idx
1146	for reverse split /\s*,\s*/,	1266	for reverse split /\s*,\s*/,
1147	$ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";	1267	$ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";
1148	}	1268	}
1149		1269
		1270	our @post_detect;
		1271
		1272	sub post_detect(&) {
		1273	my ($cb) = @_;
		1274
		1275	push @post_detect, $cb;
		1276
		1277	defined wantarray
		1278	? bless \$cb, "AnyEvent::Util::postdetect"
		1279	: ()
		1280	}
		1281
		1282	sub AnyEvent::Util::postdetect::DESTROY {
		1283	@post_detect = grep $_ != ${$_[0]}, @post_detect;
		1284	}
		1285
		1286	our $POSTPONE_W;
		1287	our @POSTPONE;
		1288
		1289	sub _postpone_exec {
		1290	undef $POSTPONE_W;
		1291
		1292	&{ shift @POSTPONE }
		1293	while @POSTPONE;
		1294	}
		1295
		1296	sub postpone(&) {
		1297	push @POSTPONE, shift;
		1298
		1299	$POSTPONE_W ||= AE::timer (0, 0, \&_postpone_exec);
		1300
		1301	()
		1302	}
		1303
		1304	sub log($$;@) {
		1305	# only load the big bloated module when we actually are about to log something
		1306	if ($_[0] <= ($VERBOSE || 1)) { # also catches non-numeric levels(!) and fatal
		1307	local ($!, $@);
		1308	require AnyEvent::Log; # among other things, sets $VERBOSE to 9
		1309	# AnyEvent::Log overwrites this function
		1310	goto &log;
		1311	}
		1312
		1313	0 # not logged
		1314	}
		1315
		1316	sub _logger($;$) {
		1317	my ($level, $renabled) = @_;
		1318
		1319	$$renabled = $level <= $VERBOSE;
		1320
		1321	my $logger = [(caller)[0], $level, $renabled];
		1322
		1323	$AnyEvent::Log::LOGGER{$logger+0} = $logger;
		1324
		1325	# return unless defined wantarray;
		1326	#
		1327	# require AnyEvent::Util;
		1328	# my $guard = AnyEvent::Util::guard (sub {
		1329	# # "clean up"
		1330	# delete $LOGGER{$logger+0};
		1331	# });
		1332	#
		1333	# sub {
		1334	# return 0 unless $$renabled;
		1335	#
		1336	# $guard if 0; # keep guard alive, but don't cause runtime overhead
		1337	# require AnyEvent::Log unless $AnyEvent::Log::VERSION;
		1338	# package AnyEvent::Log;
		1339	# _log ($logger->[0], $level, @_) # logger->[0] has been converted at load time
		1340	# }
		1341	}
		1342
		1343	if (length $ENV{PERL_ANYEVENT_LOG}) {
		1344	require AnyEvent::Log; # AnyEvent::Log does the thing for us
		1345	}
		1346
1150	my @models = (	1347	our @models = (
1151	[EV:: => AnyEvent::Impl::EV:: , 1],	1348	[EV:: => AnyEvent::Impl::EV::],
1152	[Event:: => AnyEvent::Impl::Event::, 1],	1349	[AnyEvent::Loop:: => AnyEvent::Impl::Perl::],
1153	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl:: , 1],
1154	# everything below here will not (normally) be autoprobed	1350	# everything below here will not (normally) be autoprobed
1155	# as the pureperl backend should work everywhere	1351	# as the pure perl backend should work everywhere
1156	# and is usually faster	1352	# and is usually faster
		1353	[Irssi:: => AnyEvent::Impl::Irssi::], # Irssi has a bogus "Event" package, so msut be near the top
		1354	[Event:: => AnyEvent::Impl::Event::], # slow, stable
1157	[Glib:: => AnyEvent::Impl::Glib:: , 1], # becomes extremely slow with many watchers	1355	[Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers
		1356	# everything below here should not be autoloaded
1158	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy	1357	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
1159	[Irssi:: => AnyEvent::Impl::Irssi::], # Irssi has a bogus "Event" package
1160	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles	1358	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
1161	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program	1359	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program
1162	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza	1360	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
1163	[Wx:: => AnyEvent::Impl::POE::],	1361	[Wx:: => AnyEvent::Impl::POE::],
1164	[Prima:: => AnyEvent::Impl::POE::],	1362	[Prima:: => AnyEvent::Impl::POE::],
1165	# IO::Async is just too broken - we would need workarounds for its	1363	[IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # a bitch to autodetect
1166	# byzantine signal and broken child handling, among others.	1364	[Cocoa::EventLoop:: => AnyEvent::Impl::Cocoa::],
1167	# IO::Async is rather hard to detect, as it doesn't have any	1365	[FLTK:: => AnyEvent::Impl::FLTK::],
1168	# obvious default class.
1169	# [0, IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program
1170	# [0, IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program
1171	# [0, IO::Async::Notifier:: => AnyEvent::Impl::IOAsync::], # requires special main program
1172	);	1366	);
1173		1367
1174	our %method = map +($_ => 1),	1368	our @isa_hook;
		1369
		1370	sub _isa_set {
		1371	my @pkg = ("AnyEvent", (map $_->[0], grep defined, @isa_hook), $MODEL);
		1372
		1373	@{"$pkg[$_-1]::ISA"} = $pkg[$_]
		1374	for 1 .. $#pkg;
		1375
		1376	grep $_ && $_->[1], @isa_hook
		1377	and AE::_reset ();
		1378	}
		1379
		1380	# used for hooking AnyEvent::Strict and AnyEvent::Debug::Wrap into the class hierarchy
		1381	sub _isa_hook($$;$) {
		1382	my ($i, $pkg, $reset_ae) = @_;
		1383
		1384	$isa_hook[$i] = $pkg ? [$pkg, $reset_ae] : undef;
		1385
		1386	_isa_set;
		1387	}
		1388
		1389	# all autoloaded methods reserve the complete glob, not just the method slot.
		1390	# due to bugs in perls method cache implementation.
1175	qw(io timer time now now_update signal child idle condvar one_event DESTROY);	1391	our @methods = qw(io timer time now now_update signal child idle condvar);
1176		1392
1177	our @post_detect;
1178
1179	sub post_detect(&) {	1393	sub detect() {
1180	my ($cb) = @_;	1394	return $MODEL if $MODEL; # some programs keep references to detect
1181		1395
1182	if ($MODEL) {	1396	# IO::Async::Loop::AnyEvent is extremely evil, refuse to work with it
1183	$cb->();	1397	# the author knows about the problems and what it does to AnyEvent as a whole
		1398	# (and the ability of others to use AnyEvent), but simply wants to abuse AnyEvent
		1399	# anyway.
		1400	AnyEvent::log fatal => "AnyEvent: IO::Async::Loop::AnyEvent detected - this module is broken by design,\n"
		1401	. "abuses internals and breaks AnyEvent, will not continue."
		1402	if exists $INC{"IO/Async/Loop/AnyEvent.pm"};
1184		1403
1185	undef	1404	local $!; # for good measure
		1405	local $SIG{__DIE__}; # we use eval
		1406
		1407	# free some memory
		1408	*detect = sub () { $MODEL };
		1409	# undef &func doesn't correctly update the method cache. grmbl.
		1410	# so we delete the whole glob. grmbl.
		1411	# otoh, perl doesn't let me undef an active usb, but it lets me free
		1412	# a glob with an active sub. hrm. i hope it works, but perl is
		1413	# usually buggy in this department. sigh.
		1414	delete @{"AnyEvent::"}{@methods};
		1415	undef @methods;
		1416
		1417	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z0-9:]+)$/) {
		1418	my $model = $1;
		1419	$model = "AnyEvent::Impl::$model" unless $model =~ s/::$//;
		1420	if (eval "require $model") {
		1421	AnyEvent::log 7 => "loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.";
		1422	$MODEL = $model;
1186	} else {	1423	} else {
1187	push @post_detect, $cb;	1424	AnyEvent::log 4 => "unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@";
1188		1425	}
1189	defined wantarray
1190	? bless \$cb, "AnyEvent::Util::postdetect"
1191	: ()
1192	}	1426	}
1193	}
1194		1427
1195	sub AnyEvent::Util::postdetect::DESTROY {	1428	# check for already loaded models
1196	@post_detect = grep $_ != ${$_[0]}, @post_detect;
1197	}
1198
1199	sub detect() {
1200	unless ($MODEL) {	1429	unless ($MODEL) {
1201	local $SIG{__DIE__};	1430	for (@REGISTRY, @models) {
1202		1431	my ($package, $model) = @$_;
1203	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {	1432	if (${"$package\::VERSION"} > 0) {
1204	my $model = "AnyEvent::Impl::$1";
1205	if (eval "require $model") {	1433	if (eval "require $model") {
		1434	AnyEvent::log 7 => "autodetected model '$model', using it.";
1206	$MODEL = $model;	1435	$MODEL = $model;
1207	warn "AnyEvent: loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.\n" if $VERBOSE >= 2;	1436	last;
1208	} else {	1437	}
1209	warn "AnyEvent: unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@" if $VERBOSE;
1210	}	1438	}
1211	}	1439	}
1212		1440
1213	# check for already loaded models
1214	unless ($MODEL) {	1441	unless ($MODEL) {
		1442	# try to autoload a model
1215	for (@REGISTRY, @models) {	1443	for (@REGISTRY, @models) {
1216	my ($package, $model) = @$_;	1444	my ($package, $model) = @$_;
		1445	if (
		1446	eval "require $package"
1217	if (${"$package\::VERSION"} > 0) {	1447	and ${"$package\::VERSION"} > 0
1218	if (eval "require $model") {	1448	and eval "require $model"
		1449	) {
		1450	AnyEvent::log 7 => "autoloaded model '$model', using it.";
1219	$MODEL = $model;	1451	$MODEL = $model;
1220	warn "AnyEvent: autodetected model '$model', using it.\n" if $VERBOSE >= 2;
1221	last;	1452	last;
1222	}
1223	}	1453	}
1224	}	1454	}
1225		1455
1226	unless ($MODEL) {
1227	# try to autoload a model
1228	for (@REGISTRY, @models) {
1229	my ($package, $model, $autoload) = @$_;
1230	if (
1231	$autoload
1232	and eval "require $package"
1233	and ${"$package\::VERSION"} > 0
1234	and eval "require $model"
1235	) {
1236	$MODEL = $model;
1237	warn "AnyEvent: autoloaded model '$model', using it.\n" if $VERBOSE >= 2;
1238	last;
1239	}
1240	}
1241
1242	$MODEL	1456	$MODEL
1243	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.\n";	1457	or AnyEvent::log fatal => "AnyEvent: backend autodetection failed - did you properly install AnyEvent?";
1244	}
1245	}	1458	}
1246
1247	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
1248
1249	unshift @ISA, $MODEL;
1250
1251	require AnyEvent::Strict if $ENV{PERL_ANYEVENT_STRICT};
1252
1253	(shift @post_detect)->() while @post_detect;
1254	}	1459	}
1255		1460
		1461	# free memory only needed for probing
		1462	undef @models;
		1463	undef @REGISTRY;
		1464
		1465	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
		1466
		1467	# now nuke some methods that are overridden by the backend.
		1468	# SUPER usage is not allowed in these.
		1469	for (qw(time signal child idle)) {
		1470	undef &{"AnyEvent::Base::$_"}
		1471	if defined &{"$MODEL\::$_"};
		1472	}
		1473
		1474	_isa_set;
		1475
		1476	# we're officially open!
		1477
		1478	if ($ENV{PERL_ANYEVENT_STRICT}) {
		1479	require AnyEvent::Strict;
		1480	}
		1481
		1482	if ($ENV{PERL_ANYEVENT_DEBUG_WRAP}) {
		1483	require AnyEvent::Debug;
		1484	AnyEvent::Debug::wrap ($ENV{PERL_ANYEVENT_DEBUG_WRAP});
		1485	}
		1486
		1487	if (length $ENV{PERL_ANYEVENT_DEBUG_SHELL}) {
		1488	require AnyEvent::Socket;
		1489	require AnyEvent::Debug;
		1490
		1491	my $shell = $ENV{PERL_ANYEVENT_DEBUG_SHELL};
		1492	$shell =~ s/\$\$/$$/g;
		1493
		1494	my ($host, $service) = AnyEvent::Socket::parse_hostport ($shell);
		1495	$AnyEvent::Debug::SHELL = AnyEvent::Debug::shell ($host, $service);
		1496	}
		1497
		1498	# now the anyevent environment is set up as the user told us to, so
		1499	# call the actual user code - post detects
		1500
		1501	(shift @post_detect)->() while @post_detect;
		1502	undef @post_detect;
		1503
		1504	*post_detect = sub(&) {
		1505	shift->();
		1506
		1507	undef
		1508	};
		1509
1256	$MODEL	1510	$MODEL
1257	}	1511	}
1258		1512
1259	sub AUTOLOAD {	1513	for my $name (@methods) {
1260	(my $func = $AUTOLOAD) =~ s/.*://;	1514	*$name = sub {
1261		1515	detect;
1262	$method{$func}	1516	# we use goto because
1263	or Carp::croak "$func: not a valid method for AnyEvent objects";	1517	# a) it makes the thunk more transparent
1264		1518	# b) it allows us to delete the thunk later
1265	detect unless $MODEL;	1519	goto &{ UNIVERSAL::can AnyEvent => "SUPER::$name" }
1266		1520	};
1267	my $class = shift;
1268	$class->$func (@_);
1269	}	1521	}
1270		1522
1271	# utility function to dup a filehandle. this is used by many backends	1523	# utility function to dup a filehandle. this is used by many backends
1272	# to support binding more than one watcher per filehandle (they usually	1524	# to support binding more than one watcher per filehandle (they usually
1273	# allow only one watcher per fd, so we dup it to get a different one).	1525	# allow only one watcher per fd, so we dup it to get a different one).
…		…
1283	# we assume CLOEXEC is already set by perl in all important cases	1535	# we assume CLOEXEC is already set by perl in all important cases
1284		1536
1285	($fh2, $rw)	1537	($fh2, $rw)
1286	}	1538	}
1287		1539
		1540	=head1 SIMPLIFIED AE API
		1541
		1542	Starting with version 5.0, AnyEvent officially supports a second, much
		1543	simpler, API that is designed to reduce the calling, typing and memory
		1544	overhead by using function call syntax and a fixed number of parameters.
		1545
		1546	See the L<AE> manpage for details.
		1547
		1548	=cut
		1549
		1550	package AE;
		1551
		1552	our $VERSION = $AnyEvent::VERSION;
		1553
		1554	sub _reset() {
		1555	eval q{
		1556	# fall back to the main API by default - backends and AnyEvent::Base
		1557	# implementations can overwrite these.
		1558
		1559	sub io($$$) {
		1560	AnyEvent->io (fh => $_[0], poll => $_[1] ? "w" : "r", cb => $_[2])
		1561	}
		1562
		1563	sub timer($$$) {
		1564	AnyEvent->timer (after => $_[0], interval => $_[1], cb => $_[2])
		1565	}
		1566
		1567	sub signal($$) {
		1568	AnyEvent->signal (signal => $_[0], cb => $_[1])
		1569	}
		1570
		1571	sub child($$) {
		1572	AnyEvent->child (pid => $_[0], cb => $_[1])
		1573	}
		1574
		1575	sub idle($) {
		1576	AnyEvent->idle (cb => $_[0]);
		1577	}
		1578
		1579	sub cv(;&) {
		1580	AnyEvent->condvar (@_ ? (cb => $_[0]) : ())
		1581	}
		1582
		1583	sub now() {
		1584	AnyEvent->now
		1585	}
		1586
		1587	sub now_update() {
		1588	AnyEvent->now_update
		1589	}
		1590
		1591	sub time() {
		1592	AnyEvent->time
		1593	}
		1594
		1595	*postpone = \&AnyEvent::postpone;
		1596	*log = \&AnyEvent::log;
		1597	};
		1598	die if $@;
		1599	}
		1600
		1601	BEGIN { _reset }
		1602
1288	package AnyEvent::Base;	1603	package AnyEvent::Base;
1289		1604
1290	# default implementations for many methods	1605	# default implementations for many methods
1291		1606
1292	sub _time {	1607	sub time {
		1608	eval q{ # poor man's autoloading {}
1293	# probe for availability of Time::HiRes	1609	# probe for availability of Time::HiRes
1294	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {	1610	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {
1295	warn "AnyEvent: using Time::HiRes for sub-second timing accuracy.\n" if $VERBOSE >= 8;	1611	*time = sub { Time::HiRes::time () };
1296	*_time = \&Time::HiRes::time;	1612	*AE::time = \& Time::HiRes::time ;
		1613	*now = \&time;
		1614	AnyEvent::log 8 => "AnyEvent: using Time::HiRes for sub-second timing accuracy.";
1297	# if (eval "use POSIX (); (POSIX::times())...	1615	# if (eval "use POSIX (); (POSIX::times())...
1298	} else {	1616	} else {
		1617	*time = sub { CORE::time };
		1618	*AE::time = sub (){ CORE::time };
		1619	*now = \&time;
1299	warn "AnyEvent: using built-in time(), WARNING, no sub-second resolution!\n" if $VERBOSE;	1620	AnyEvent::log 3 => "using built-in time(), WARNING, no sub-second resolution!";
1300	*_time = sub { time }; # epic fail	1621	}
1301	}	1622	};
		1623	die if $@;
1302		1624
1303	&_time	1625	&time
1304	}	1626	}
1305		1627
1306	sub time { _time }	1628	*now = \&time;
1307	sub now { _time }
1308	sub now_update { }	1629	sub now_update { }
1309		1630
		1631	sub _poll {
		1632	Carp::croak "$AnyEvent::MODEL does not support blocking waits. Caught";
		1633	}
		1634
1310	# default implementation for ->condvar	1635	# default implementation for ->condvar
		1636	# in fact, the default should not be overwritten
1311		1637
1312	sub condvar {	1638	sub condvar {
		1639	eval q{ # poor man's autoloading {}
		1640	*condvar = sub {
1313	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"	1641	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"
		1642	};
		1643
		1644	*AE::cv = sub (;&) {
		1645	bless { @_ ? (_ae_cb => shift) : () }, "AnyEvent::CondVar"
		1646	};
		1647	};
		1648	die if $@;
		1649
		1650	&condvar
1314	}	1651	}
1315		1652
1316	# default implementation for ->signal	1653	# default implementation for ->signal
1317		1654
1318	our $HAVE_ASYNC_INTERRUPT;	1655	our $HAVE_ASYNC_INTERRUPT;
1319		1656
1320	sub _have_async_interrupt() {	1657	sub _have_async_interrupt() {
1321	$HAVE_ASYNC_INTERRUPT = 1*(!$ENV{PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT}	1658	$HAVE_ASYNC_INTERRUPT = 1*(!$ENV{PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT}
1322	&& eval "use Async::Interrupt 1.0 (); 1")	1659	&& eval "use Async::Interrupt 1.02 (); 1")
1323	unless defined $HAVE_ASYNC_INTERRUPT;	1660	unless defined $HAVE_ASYNC_INTERRUPT;
1324		1661
1325	$HAVE_ASYNC_INTERRUPT	1662	$HAVE_ASYNC_INTERRUPT
1326	}	1663	}
1327		1664
1328	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);	1665	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);
1329	our (%SIG_ASY, %SIG_ASY_W);	1666	our (%SIG_ASY, %SIG_ASY_W);
1330	our ($SIG_COUNT, $SIG_TW);	1667	our ($SIG_COUNT, $SIG_TW);
1331		1668
1332	sub _signal_exec {
1333	$HAVE_ASYNC_INTERRUPT
1334	? $SIGPIPE_R->drain
1335	: sysread $SIGPIPE_R, my $dummy, 9;
1336
1337	while (%SIG_EV) {
1338	for (keys %SIG_EV) {
1339	delete $SIG_EV{$_};
1340	$_->() for values %{ $SIG_CB{$_} || {} };
1341	}
1342	}
1343	}
1344
1345	# install a dummy wakeup watcher to reduce signal catching latency	1669	# install a dummy wakeup watcher to reduce signal catching latency
		1670	# used by Impls
1346	sub _sig_add() {	1671	sub _sig_add() {
1347	unless ($SIG_COUNT++) {	1672	unless ($SIG_COUNT++) {
1348	# try to align timer on a full-second boundary, if possible	1673	# try to align timer on a full-second boundary, if possible
1349	my $NOW = AnyEvent->now;	1674	my $NOW = AE::now;
1350		1675
1351	$SIG_TW = AnyEvent->timer (	1676	$SIG_TW = AE::timer
1352	after => $MAX_SIGNAL_LATENCY - ($NOW - int $NOW),	1677	$MAX_SIGNAL_LATENCY - ($NOW - int $NOW),
1353	interval => $MAX_SIGNAL_LATENCY,	1678	$MAX_SIGNAL_LATENCY,
1354	cb => sub { }, # just for the PERL_ASYNC_CHECK	1679	sub { } # just for the PERL_ASYNC_CHECK
1355	);	1680	;
1356	}	1681	}
1357	}	1682	}
1358		1683
1359	sub _sig_del {	1684	sub _sig_del {
1360	undef $SIG_TW	1685	undef $SIG_TW
1361	unless --$SIG_COUNT;	1686	unless --$SIG_COUNT;
1362	}	1687	}
1363		1688
1364	our $_sig_name_init; $_sig_name_init = sub {	1689	our $_sig_name_init; $_sig_name_init = sub {
1365	eval q{ # poor man's autoloading	1690	eval q{ # poor man's autoloading {}
1366	undef $_sig_name_init;	1691	undef $_sig_name_init;
1367		1692
1368	if (_have_async_interrupt) {	1693	if (_have_async_interrupt) {
1369	*sig2num = \&Async::Interrupt::sig2num;	1694	*sig2num = \&Async::Interrupt::sig2num;
1370	*sig2name = \&Async::Interrupt::sig2name;	1695	*sig2name = \&Async::Interrupt::sig2name;
…		…
1394		1719
1395	sub signal {	1720	sub signal {
1396	eval q{ # poor man's autoloading {}	1721	eval q{ # poor man's autoloading {}
1397	# probe for availability of Async::Interrupt	1722	# probe for availability of Async::Interrupt
1398	if (_have_async_interrupt) {	1723	if (_have_async_interrupt) {
1399	warn "AnyEvent: using Async::Interrupt for race-free signal handling.\n" if $VERBOSE >= 8;	1724	AnyEvent::log 8 => "using Async::Interrupt for race-free signal handling.";
1400		1725
1401	$SIGPIPE_R = new Async::Interrupt::EventPipe;	1726	$SIGPIPE_R = new Async::Interrupt::EventPipe;
1402	$SIG_IO = AnyEvent->io (fh => $SIGPIPE_R->fileno, poll => "r", cb => \&_signal_exec);	1727	$SIG_IO = AE::io $SIGPIPE_R->fileno, 0, \&_signal_exec;
1403		1728
1404	} else {	1729	} else {
1405	warn "AnyEvent: using emulated perl signal handling with latency timer.\n" if $VERBOSE >= 8;	1730	AnyEvent::log 8 => "using emulated perl signal handling with latency timer.";
1406
1407	require Fcntl;
1408		1731
1409	if (AnyEvent::WIN32) {	1732	if (AnyEvent::WIN32) {
1410	require AnyEvent::Util;	1733	require AnyEvent::Util;
1411		1734
1412	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();	1735	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
1413	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R, 1) if $SIGPIPE_R;	1736	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R, 1) if $SIGPIPE_R;
1414	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W, 1) if $SIGPIPE_W; # just in case	1737	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W, 1) if $SIGPIPE_W; # just in case
1415	} else {	1738	} else {
1416	pipe $SIGPIPE_R, $SIGPIPE_W;	1739	pipe $SIGPIPE_R, $SIGPIPE_W;
1417	fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R;	1740	fcntl $SIGPIPE_R, AnyEvent::F_SETFL, AnyEvent::O_NONBLOCK if $SIGPIPE_R;
1418	fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case	1741	fcntl $SIGPIPE_W, AnyEvent::F_SETFL, AnyEvent::O_NONBLOCK if $SIGPIPE_W; # just in case
1419		1742
1420	# not strictly required, as $^F is normally 2, but let's make sure...	1743	# not strictly required, as $^F is normally 2, but let's make sure...
1421	fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;	1744	fcntl $SIGPIPE_R, AnyEvent::F_SETFD, AnyEvent::FD_CLOEXEC;
1422	fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;	1745	fcntl $SIGPIPE_W, AnyEvent::F_SETFD, AnyEvent::FD_CLOEXEC;
1423	}	1746	}
1424		1747
1425	$SIGPIPE_R	1748	$SIGPIPE_R
1426	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";	1749	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";
1427		1750
1428	$SIG_IO = AnyEvent->io (fh => $SIGPIPE_R, poll => "r", cb => \&_signal_exec);	1751	$SIG_IO = AE::io $SIGPIPE_R, 0, \&_signal_exec;
1429	}	1752	}
1430		1753
1431	*signal = sub {	1754	*signal = $HAVE_ASYNC_INTERRUPT
		1755	? sub {
1432	my (undef, %arg) = @_;	1756	my (undef, %arg) = @_;
1433		1757
1434	my $signal = uc $arg{signal}
1435	or Carp::croak "required option 'signal' is missing";
1436
1437	if ($HAVE_ASYNC_INTERRUPT) {
1438	# async::interrupt	1758	# async::interrupt
1439
1440	$signal = sig2num $signal;	1759	my $signal = sig2num $arg{signal};
1441	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};	1760	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
1442		1761
1443	$SIG_ASY{$signal} ||= new Async::Interrupt	1762	$SIG_ASY{$signal} ||= new Async::Interrupt
1444	cb => sub { undef $SIG_EV{$signal} },	1763	cb => sub { undef $SIG_EV{$signal} },
1445	signal => $signal,	1764	signal => $signal,
1446	pipe => [$SIGPIPE_R->filenos],	1765	pipe => [$SIGPIPE_R->filenos],
1447	pipe_autodrain => 0,	1766	pipe_autodrain => 0,
1448	;	1767	;
1449		1768
1450	} else {	1769	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
		1770	}
		1771	: sub {
		1772	my (undef, %arg) = @_;
		1773
1451	# pure perl	1774	# pure perl
1452
1453	# AE::Util has been loaded in signal
1454	$signal = sig2name $signal;	1775	my $signal = sig2name $arg{signal};
1455	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};	1776	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
1456		1777
1457	$SIG{$signal} ||= sub {	1778	$SIG{$signal} ||= sub {
1458	local $!;	1779	local $!;
1459	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;	1780	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;
1460	undef $SIG_EV{$signal};	1781	undef $SIG_EV{$signal};
1461	};	1782	};
1462		1783
1463	# can't do signal processing without introducing races in pure perl,	1784	# can't do signal processing without introducing races in pure perl,
1464	# so limit the signal latency.	1785	# so limit the signal latency.
1465	_sig_add;	1786	_sig_add;
1466	}
1467		1787
1468	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"	1788	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
		1789	}
1469	};	1790	;
1470		1791
1471	*AnyEvent::Base::signal::DESTROY = sub {	1792	*AnyEvent::Base::signal::DESTROY = sub {
1472	my ($signal, $cb) = @{$_[0]};	1793	my ($signal, $cb) = @{$_[0]};
1473		1794
1474	_sig_del;	1795	_sig_del;
…		…
1481	# print weird messages, or just unconditionally exit	1802	# print weird messages, or just unconditionally exit
1482	# instead of getting the default action.	1803	# instead of getting the default action.
1483	undef $SIG{$signal}	1804	undef $SIG{$signal}
1484	unless keys %{ $SIG_CB{$signal} };	1805	unless keys %{ $SIG_CB{$signal} };
1485	};	1806	};
		1807
		1808	*_signal_exec = sub {
		1809	$HAVE_ASYNC_INTERRUPT
		1810	? $SIGPIPE_R->drain
		1811	: sysread $SIGPIPE_R, (my $dummy), 9;
		1812
		1813	while (%SIG_EV) {
		1814	for (keys %SIG_EV) {
		1815	delete $SIG_EV{$_};
		1816	&$_ for values %{ $SIG_CB{$_} || {} };
		1817	}
		1818	}
		1819	};
1486	};	1820	};
1487	die if $@;	1821	die if $@;
		1822
1488	&signal	1823	&signal
1489	}	1824	}
1490		1825
1491	# default implementation for ->child	1826	# default implementation for ->child
1492		1827
1493	our %PID_CB;	1828	our %PID_CB;
1494	our $CHLD_W;	1829	our $CHLD_W;
1495	our $CHLD_DELAY_W;	1830	our $CHLD_DELAY_W;
1496	our $WNOHANG;
1497		1831
		1832	# used by many Impl's
1498	sub _emit_childstatus($$) {	1833	sub _emit_childstatus($$) {
1499	my (undef, $rpid, $rstatus) = @_;	1834	my (undef, $rpid, $rstatus) = @_;
1500		1835
1501	$_->($rpid, $rstatus)	1836	$_->($rpid, $rstatus)
1502	for values %{ $PID_CB{$rpid} || {} },	1837	for values %{ $PID_CB{$rpid} || {} },
1503	values %{ $PID_CB{0} || {} };	1838	values %{ $PID_CB{0} || {} };
1504	}	1839	}
1505		1840
1506	sub _sigchld {
1507	my $pid;
1508
1509	AnyEvent->_emit_childstatus ($pid, $?)
1510	while ($pid = waitpid -1, $WNOHANG) > 0;
1511	}
1512
1513	sub child {	1841	sub child {
		1842	eval q{ # poor man's autoloading {}
		1843	*_sigchld = sub {
		1844	my $pid;
		1845
		1846	AnyEvent->_emit_childstatus ($pid, $?)
		1847	while ($pid = waitpid -1, WNOHANG) > 0;
		1848	};
		1849
		1850	*child = sub {
1514	my (undef, %arg) = @_;	1851	my (undef, %arg) = @_;
1515		1852
1516	defined (my $pid = $arg{pid} + 0)	1853	my $pid = $arg{pid};
1517	or Carp::croak "required option 'pid' is missing";	1854	my $cb = $arg{cb};
1518		1855
1519	$PID_CB{$pid}{$arg{cb}} = $arg{cb};	1856	$PID_CB{$pid}{$cb+0} = $cb;
1520		1857
1521	# WNOHANG is almost cetrainly 1 everywhere
1522	$WNOHANG ||= $^O =~ /^(?:openbsd|netbsd|linux|freebsd|cygwin|MSWin32)$/
1523	? 1
1524	: eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1;
1525
1526	unless ($CHLD_W) {	1858	unless ($CHLD_W) {
1527	$CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld);	1859	$CHLD_W = AE::signal CHLD => \&_sigchld;
1528	# child could be a zombie already, so make at least one round	1860	# child could be a zombie already, so make at least one round
1529	&_sigchld;	1861	&_sigchld;
1530	}	1862	}
1531		1863
1532	bless [$pid, $arg{cb}], "AnyEvent::Base::child"	1864	bless [$pid, $cb+0], "AnyEvent::Base::child"
1533	}	1865	};
1534		1866
1535	sub AnyEvent::Base::child::DESTROY {	1867	*AnyEvent::Base::child::DESTROY = sub {
1536	my ($pid, $cb) = @{$_[0]};	1868	my ($pid, $icb) = @{$_[0]};
1537		1869
1538	delete $PID_CB{$pid}{$cb};	1870	delete $PID_CB{$pid}{$icb};
1539	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };	1871	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };
1540		1872
1541	undef $CHLD_W unless keys %PID_CB;	1873	undef $CHLD_W unless keys %PID_CB;
		1874	};
		1875	};
		1876	die if $@;
		1877
		1878	&child
1542	}	1879	}
1543		1880
1544	# idle emulation is done by simply using a timer, regardless	1881	# idle emulation is done by simply using a timer, regardless
1545	# of whether the process is idle or not, and not letting	1882	# of whether the process is idle or not, and not letting
1546	# the callback use more than 50% of the time.	1883	# the callback use more than 50% of the time.
1547	sub idle {	1884	sub idle {
		1885	eval q{ # poor man's autoloading {}
		1886	*idle = sub {
1548	my (undef, %arg) = @_;	1887	my (undef, %arg) = @_;
1549		1888
1550	my ($cb, $w, $rcb) = $arg{cb};	1889	my ($cb, $w, $rcb) = $arg{cb};
1551		1890
1552	$rcb = sub {	1891	$rcb = sub {
1553	if ($cb) {	1892	if ($cb) {
1554	$w = _time;	1893	$w = AE::time;
1555	&$cb;	1894	&$cb;
1556	$w = _time - $w;	1895	$w = AE::time - $w;
1557		1896
1558	# never use more then 50% of the time for the idle watcher,	1897	# never use more then 50% of the time for the idle watcher,
1559	# within some limits	1898	# within some limits
1560	$w = 0.0001 if $w < 0.0001;	1899	$w = 0.0001 if $w < 0.0001;
1561	$w = 5 if $w > 5;	1900	$w = 5 if $w > 5;
1562		1901
1563	$w = AnyEvent->timer (after => $w, cb => $rcb);	1902	$w = AE::timer $w, 0, $rcb;
1564	} else {	1903	} else {
1565	# clean up...	1904	# clean up...
1566	undef $w;	1905	undef $w;
1567	undef $rcb;	1906	undef $rcb;
		1907	}
		1908	};
		1909
		1910	$w = AE::timer 0.05, 0, $rcb;
		1911
		1912	bless \\$cb, "AnyEvent::Base::idle"
1568	}	1913	};
		1914
		1915	*AnyEvent::Base::idle::DESTROY = sub {
		1916	undef $${$_[0]};
		1917	};
1569	};	1918	};
		1919	die if $@;
1570		1920
1571	$w = AnyEvent->timer (after => 0.05, cb => $rcb);	1921	&idle
1572
1573	bless \\$cb, "AnyEvent::Base::idle"
1574	}
1575
1576	sub AnyEvent::Base::idle::DESTROY {
1577	undef $${$_[0]};
1578	}	1922	}
1579		1923
1580	package AnyEvent::CondVar;	1924	package AnyEvent::CondVar;
1581		1925
1582	our @ISA = AnyEvent::CondVar::Base::;	1926	our @ISA = AnyEvent::CondVar::Base::;
		1927
		1928	# only to be used for subclassing
		1929	sub new {
		1930	my $class = shift;
		1931	bless AnyEvent->condvar (@_), $class
		1932	}
1583		1933
1584	package AnyEvent::CondVar::Base;	1934	package AnyEvent::CondVar::Base;
1585		1935
1586	#use overload	1936	#use overload
1587	# '&{}' => sub { my $self = shift; sub { $self->send (@_) } },	1937	# '&{}' => sub { my $self = shift; sub { $self->send (@_) } },
…		…
1597		1947
1598	sub _send {	1948	sub _send {
1599	# nop	1949	# nop
1600	}	1950	}
1601		1951
		1952	sub _wait {
		1953	AnyEvent->_poll until $_[0]{_ae_sent};
		1954	}
		1955
1602	sub send {	1956	sub send {
1603	my $cv = shift;	1957	my $cv = shift;
1604	$cv->{_ae_sent} = [@_];	1958	$cv->{_ae_sent} = [@_];
1605	(delete $cv->{_ae_cb})->($cv) if $cv->{_ae_cb};	1959	(delete $cv->{_ae_cb})->($cv) if $cv->{_ae_cb};
1606	$cv->_send;	1960	$cv->_send;
…		…
1613		1967
1614	sub ready {	1968	sub ready {
1615	$_[0]{_ae_sent}	1969	$_[0]{_ae_sent}
1616	}	1970	}
1617		1971
1618	sub _wait {
1619	$WAITING
1620	and !$_[0]{_ae_sent}
1621	and Carp::croak "AnyEvent::CondVar: recursive blocking wait detected";
1622
1623	local $WAITING = 1;
1624	AnyEvent->one_event while !$_[0]{_ae_sent};
1625	}
1626
1627	sub recv {	1972	sub recv {
		1973	unless ($_[0]{_ae_sent}) {
		1974	$WAITING
		1975	and Carp::croak "AnyEvent::CondVar: recursive blocking wait attempted";
		1976
		1977	local $WAITING = 1;
1628	$_[0]->_wait;	1978	$_[0]->_wait;
		1979	}
1629		1980
1630	Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak};	1981	$_[0]{_ae_croak}
1631	wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0]	1982	and Carp::croak $_[0]{_ae_croak};
		1983
		1984	wantarray
		1985	? @{ $_[0]{_ae_sent} }
		1986	: $_[0]{_ae_sent}[0]
1632	}	1987	}
1633		1988
1634	sub cb {	1989	sub cb {
1635	$_[0]{_ae_cb} = $_[1] if @_ > 1;	1990	my $cv = shift;
		1991
		1992	@_
		1993	and $cv->{_ae_cb} = shift
		1994	and $cv->{_ae_sent}
		1995	and (delete $cv->{_ae_cb})->($cv);
		1996
1636	$_[0]{_ae_cb}	1997	$cv->{_ae_cb}
1637	}	1998	}
1638		1999
1639	sub begin {	2000	sub begin {
1640	++$_[0]{_ae_counter};	2001	++$_[0]{_ae_counter};
1641	$_[0]{_ae_end_cb} = $_[1] if @_ > 1;	2002	$_[0]{_ae_end_cb} = $_[1] if @_ > 1;
…		…
1646	&{ $_[0]{_ae_end_cb} || sub { $_[0]->send } };	2007	&{ $_[0]{_ae_end_cb} || sub { $_[0]->send } };
1647	}	2008	}
1648		2009
1649	# undocumented/compatibility with pre-3.4	2010	# undocumented/compatibility with pre-3.4
1650	*broadcast = \&send;	2011	*broadcast = \&send;
1651	*wait = \&_wait;	2012	*wait = \&recv;
1652
1653	#############################################################################
1654	# "new" API, currently only emulation of it
1655	#############################################################################
1656
1657	package AE;
1658
1659	sub io($$$) {
1660	AnyEvent->io (fh => $_[0], poll => $_[1] ? "w" : "r", cb => $_[2])
1661	}
1662
1663	sub timer($$$) {
1664	AnyEvent->timer (after => $_[0], interval => $_[1], cb => $_[2]);
1665	}
1666
1667	sub signal($$) {
1668	AnyEvent->signal (signal => $_[0], cb => $_[1]);
1669	}
1670
1671	sub child($$) {
1672	AnyEvent->child (pid => $_[0], cb => $_[1]);
1673	}
1674
1675	sub idle($) {
1676	AnyEvent->idle (cb => $_[0]);
1677	}
1678
1679	sub cv() {
1680	AnyEvent->condvar
1681	}
1682
1683	sub now() {
1684	AnyEvent->now
1685	}
1686
1687	sub now_update() {
1688	AnyEvent->now_update
1689	}
1690
1691	sub time() {
1692	AnyEvent->time
1693	}
1694		2013
1695	=head1 ERROR AND EXCEPTION HANDLING	2014	=head1 ERROR AND EXCEPTION HANDLING
1696		2015
1697	In general, AnyEvent does not do any error handling - it relies on the	2016	In general, AnyEvent does not do any error handling - it relies on the
1698	caller to do that if required. The L<AnyEvent::Strict> module (see also	2017	caller to do that if required. The L<AnyEvent::Strict> module (see also
…		…
1710	$Event/EV::DIED->() >>, L<Glib> uses C<< install_exception_handler >> and	2029	$Event/EV::DIED->() >>, L<Glib> uses C<< install_exception_handler >> and
1711	so on.	2030	so on.
1712		2031
1713	=head1 ENVIRONMENT VARIABLES	2032	=head1 ENVIRONMENT VARIABLES
1714		2033
1715	The following environment variables are used by this module or its	2034	AnyEvent supports a number of environment variables that tune the
1716	submodules.	2035	runtime behaviour. They are usually evaluated when AnyEvent is
		2036	loaded, initialised, or a submodule that uses them is loaded. Many of
		2037	them also cause AnyEvent to load additional modules - for example,
		2038	C<PERL_ANYEVENT_DEBUG_WRAP> causes the L<AnyEvent::Debug> module to be
		2039	loaded.
1717		2040
1718	Note that AnyEvent will remove I<all> environment variables starting with	2041	All the environment variables documented here start with
1719	C<PERL_ANYEVENT_> from C<%ENV> when it is loaded while taint mode is	2042	C<PERL_ANYEVENT_>, which is what AnyEvent considers its own
1720	enabled.	2043	namespace. Other modules are encouraged (but by no means required) to use
		2044	C<PERL_ANYEVENT_SUBMODULE> if they have registered the AnyEvent::Submodule
		2045	namespace on CPAN, for any submodule. For example, L<AnyEvent::HTTP> could
		2046	be expected to use C<PERL_ANYEVENT_HTTP_PROXY> (it should not access env
		2047	variables starting with C<AE_>, see below).
		2048
		2049	All variables can also be set via the C<AE_> prefix, that is, instead
		2050	of setting C<PERL_ANYEVENT_VERBOSE> you can also set C<AE_VERBOSE>. In
		2051	case there is a clash btween anyevent and another program that uses
		2052	C<AE_something> you can set the corresponding C<PERL_ANYEVENT_something>
		2053	variable to the empty string, as those variables take precedence.
		2054
		2055	When AnyEvent is first loaded, it copies all C<AE_xxx> env variables
		2056	to their C<PERL_ANYEVENT_xxx> counterpart unless that variable already
		2057	exists. If taint mode is on, then AnyEvent will remove I<all> environment
		2058	variables starting with C<PERL_ANYEVENT_> from C<%ENV> (or replace them
		2059	with C<undef> or the empty string, if the corresaponding C<AE_> variable
		2060	is set).
		2061
		2062	The exact algorithm is currently:
		2063
		2064	1. if taint mode enabled, delete all PERL_ANYEVENT_xyz variables from %ENV
		2065	2. copy over AE_xyz to PERL_ANYEVENT_xyz unless the latter alraedy exists
		2066	3. if taint mode enabled, set all PERL_ANYEVENT_xyz variables to undef.
		2067
		2068	This ensures that child processes will not see the C<AE_> variables.
		2069
		2070	The following environment variables are currently known to AnyEvent:
1721		2071
1722	=over 4	2072	=over 4
1723		2073
1724	=item C<PERL_ANYEVENT_VERBOSE>	2074	=item C<PERL_ANYEVENT_VERBOSE>
1725		2075
1726	By default, AnyEvent will be completely silent except in fatal	2076	By default, AnyEvent will only log messages with loglevel C<3>
1727	conditions. You can set this environment variable to make AnyEvent more	2077	(C<critical>) or higher (see L<AnyEvent::Log>). You can set this
		2078	environment variable to a numerical loglevel to make AnyEvent more (or
1728	talkative.	2079	less) talkative.
1729		2080
		2081	If you want to do more than just set the global logging level
		2082	you should have a look at C<PERL_ANYEVENT_LOG>, which allows much more
		2083	complex specifications.
		2084
		2085	When set to C<0> (C<off>), then no messages whatsoever will be logged with
		2086	the default logging settings.
		2087
1730	When set to C<1> or higher, causes AnyEvent to warn about unexpected	2088	When set to C<5> or higher (C<warn>), causes AnyEvent to warn about
1731	conditions, such as not being able to load the event model specified by	2089	unexpected conditions, such as not being able to load the event model
1732	C<PERL_ANYEVENT_MODEL>.	2090	specified by C<PERL_ANYEVENT_MODEL>, or a guard callback throwing an
		2091	exception - this is the minimum recommended level.
1733		2092
1734	When set to C<2> or higher, cause AnyEvent to report to STDERR which event	2093	When set to C<7> or higher (info), cause AnyEvent to report which event model it
1735	model it chooses.	2094	chooses.
1736		2095
1737	When set to C<8> or higher, then AnyEvent will report extra information on	2096	When set to C<8> or higher (debug), then AnyEvent will report extra information on
1738	which optional modules it loads and how it implements certain features.	2097	which optional modules it loads and how it implements certain features.
		2098
		2099	=item C<PERL_ANYEVENT_LOG>
		2100
		2101	Accepts rather complex logging specifications. For example, you could log
		2102	all C<debug> messages of some module to stderr, warnings and above to
		2103	stderr, and errors and above to syslog, with:
		2104
		2105	PERL_ANYEVENT_LOG=Some::Module=debug,+log:filter=warn,+%syslog:%syslog=error,syslog
		2106
		2107	For the rather extensive details, see L<AnyEvent::Log>.
		2108
		2109	This variable is evaluated when AnyEvent (or L<AnyEvent::Log>) is loaded,
		2110	so will take effect even before AnyEvent has initialised itself.
		2111
		2112	Note that specifying this environment variable causes the L<AnyEvent::Log>
		2113	module to be loaded, while C<PERL_ANYEVENT_VERBOSE> does not, so only
		2114	using the latter saves a few hundred kB of memory until the first message
		2115	is being logged.
1739		2116
1740	=item C<PERL_ANYEVENT_STRICT>	2117	=item C<PERL_ANYEVENT_STRICT>
1741		2118
1742	AnyEvent does not do much argument checking by default, as thorough	2119	AnyEvent does not do much argument checking by default, as thorough
1743	argument checking is very costly. Setting this variable to a true value	2120	argument checking is very costly. Setting this variable to a true value
…		…
1745	check the arguments passed to most method calls. If it finds any problems,	2122	check the arguments passed to most method calls. If it finds any problems,
1746	it will croak.	2123	it will croak.
1747		2124
1748	In other words, enables "strict" mode.	2125	In other words, enables "strict" mode.
1749		2126
1750	Unlike C<use strict> (or it's modern cousin, C<< use L<common::sense>	2127	Unlike C<use strict> (or its modern cousin, C<< use L<common::sense>
1751	>>, it is definitely recommended to keep it off in production. Keeping	2128	>>, it is definitely recommended to keep it off in production. Keeping
1752	C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs	2129	C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs
1753	can be very useful, however.	2130	can be very useful, however.
1754		2131
		2132	=item C<PERL_ANYEVENT_DEBUG_SHELL>
		2133
		2134	If this env variable is nonempty, then its contents will be interpreted by
		2135	C<AnyEvent::Socket::parse_hostport> and C<AnyEvent::Debug::shell> (after
		2136	replacing every occurance of C<$$> by the process pid). The shell object
		2137	is saved in C<$AnyEvent::Debug::SHELL>.
		2138
		2139	This happens when the first watcher is created.
		2140
		2141	For example, to bind a debug shell on a unix domain socket in
		2142	F<< /tmp/debug<pid>.sock >>, you could use this:
		2143
		2144	PERL_ANYEVENT_DEBUG_SHELL=/tmp/debug\$\$.sock perlprog
		2145	# connect with e.g.: socat readline /tmp/debug123.sock
		2146
		2147	Or to bind to tcp port 4545 on localhost:
		2148
		2149	PERL_ANYEVENT_DEBUG_SHELL=127.0.0.1:4545 perlprog
		2150	# connect with e.g.: telnet localhost 4545
		2151
		2152	Note that creating sockets in F</tmp> or on localhost is very unsafe on
		2153	multiuser systems.
		2154
		2155	=item C<PERL_ANYEVENT_DEBUG_WRAP>
		2156
		2157	Can be set to C<0>, C<1> or C<2> and enables wrapping of all watchers for
		2158	debugging purposes. See C<AnyEvent::Debug::wrap> for details.
		2159
1755	=item C<PERL_ANYEVENT_MODEL>	2160	=item C<PERL_ANYEVENT_MODEL>
1756		2161
1757	This can be used to specify the event model to be used by AnyEvent, before	2162	This can be used to specify the event model to be used by AnyEvent, before
1758	auto detection and -probing kicks in. It must be a string consisting	2163	auto detection and -probing kicks in.
1759	entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended	2164
		2165	It normally is a string consisting entirely of ASCII letters (e.g. C<EV>
		2166	or C<IOAsync>). The string C<AnyEvent::Impl::> gets prepended and the
1760	and the resulting module name is loaded and if the load was successful,	2167	resulting module name is loaded and - if the load was successful - used as
1761	used as event model. If it fails to load AnyEvent will proceed with	2168	event model backend. If it fails to load then AnyEvent will proceed with
1762	auto detection and -probing.	2169	auto detection and -probing.
1763		2170
1764	This functionality might change in future versions.	2171	If the string ends with C<::> instead (e.g. C<AnyEvent::Impl::EV::>) then
		2172	nothing gets prepended and the module name is used as-is (hint: C<::> at
		2173	the end of a string designates a module name and quotes it appropriately).
1765		2174
1766	For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you	2175	For example, to force the pure perl model (L<AnyEvent::Loop::Perl>) you
1767	could start your program like this:	2176	could start your program like this:
1768		2177
1769	PERL_ANYEVENT_MODEL=Perl perl ...	2178	PERL_ANYEVENT_MODEL=Perl perl ...
1770		2179
1771	=item C<PERL_ANYEVENT_PROTOCOLS>	2180	=item C<PERL_ANYEVENT_PROTOCOLS>
…		…
1787	but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4>	2196	but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4>
1788	- only support IPv4, never try to resolve or contact IPv6	2197	- only support IPv4, never try to resolve or contact IPv6
1789	addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or	2198	addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or
1790	IPv6, but prefer IPv6 over IPv4.	2199	IPv6, but prefer IPv6 over IPv4.
1791		2200
		2201	=item C<PERL_ANYEVENT_HOSTS>
		2202
		2203	This variable, if specified, overrides the F</etc/hosts> file used by
		2204	L<AnyEvent::Socket>C<::resolve_sockaddr>, i.e. hosts aliases will be read
		2205	from that file instead.
		2206
1792	=item C<PERL_ANYEVENT_EDNS0>	2207	=item C<PERL_ANYEVENT_EDNS0>
1793		2208
1794	Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension	2209	Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension for
1795	for DNS. This extension is generally useful to reduce DNS traffic, but	2210	DNS. This extension is generally useful to reduce DNS traffic, especially
1796	some (broken) firewalls drop such DNS packets, which is why it is off by	2211	when DNSSEC is involved, but some (broken) firewalls drop such DNS
1797	default.	2212	packets, which is why it is off by default.
1798		2213
1799	Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce	2214	Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce
1800	EDNS0 in its DNS requests.	2215	EDNS0 in its DNS requests.
1801		2216
1802	=item C<PERL_ANYEVENT_MAX_FORKS>	2217	=item C<PERL_ANYEVENT_MAX_FORKS>
…		…
1808		2223
1809	The default value for the C<max_outstanding> parameter for the default DNS	2224	The default value for the C<max_outstanding> parameter for the default DNS
1810	resolver - this is the maximum number of parallel DNS requests that are	2225	resolver - this is the maximum number of parallel DNS requests that are
1811	sent to the DNS server.	2226	sent to the DNS server.
1812		2227
		2228	=item C<PERL_ANYEVENT_MAX_SIGNAL_LATENCY>
		2229
		2230	Perl has inherently racy signal handling (you can basically choose between
		2231	losing signals and memory corruption) - pure perl event loops (including
		2232	C<AnyEvent::Loop>, when C<Async::Interrupt> isn't available) therefore
		2233	have to poll regularly to avoid losing signals.
		2234
		2235	Some event loops are racy, but don't poll regularly, and some event loops
		2236	are written in C but are still racy. For those event loops, AnyEvent
		2237	installs a timer that regularly wakes up the event loop.
		2238
		2239	By default, the interval for this timer is C<10> seconds, but you can
		2240	override this delay with this environment variable (or by setting
		2241	the C<$AnyEvent::MAX_SIGNAL_LATENCY> variable before creating signal
		2242	watchers).
		2243
		2244	Lower values increase CPU (and energy) usage, higher values can introduce
		2245	long delays when reaping children or waiting for signals.
		2246
		2247	The L<AnyEvent::Async> module, if available, will be used to avoid this
		2248	polling (with most event loops).
		2249
1813	=item C<PERL_ANYEVENT_RESOLV_CONF>	2250	=item C<PERL_ANYEVENT_RESOLV_CONF>
1814		2251
1815	The file to use instead of F</etc/resolv.conf> (or OS-specific	2252	The absolute path to a F<resolv.conf>-style file to use instead of
1816	configuration) in the default resolver. When set to the empty string, no	2253	F</etc/resolv.conf> (or the OS-specific configuration) in the default
1817	default config will be used.	2254	resolver, or the empty string to select the default configuration.
1818		2255
1819	=item C<PERL_ANYEVENT_CA_FILE>, C<PERL_ANYEVENT_CA_PATH>.	2256	=item C<PERL_ANYEVENT_CA_FILE>, C<PERL_ANYEVENT_CA_PATH>.
1820		2257
1821	When neither C<ca_file> nor C<ca_path> was specified during	2258	When neither C<ca_file> nor C<ca_path> was specified during
1822	L<AnyEvent::TLS> context creation, and either of these environment	2259	L<AnyEvent::TLS> context creation, and either of these environment
1823	variables exist, they will be used to specify CA certificate locations	2260	variables are nonempty, they will be used to specify CA certificate
1824	instead of a system-dependent default.	2261	locations instead of a system-dependent default.
1825		2262
1826	=item C<PERL_ANYEVENT_AVOID_GUARD> and C<PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT>	2263	=item C<PERL_ANYEVENT_AVOID_GUARD> and C<PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT>
1827		2264
1828	When these are set to C<1>, then the respective modules are not	2265	When these are set to C<1>, then the respective modules are not
1829	loaded. Mostly good for testing AnyEvent itself.	2266	loaded. Mostly good for testing AnyEvent itself.
…		…
1892	warn "read: $input\n"; # output what has been read	2329	warn "read: $input\n"; # output what has been read
1893	$cv->send if $input =~ /^q/i; # quit program if /^q/i	2330	$cv->send if $input =~ /^q/i; # quit program if /^q/i
1894	},	2331	},
1895	);	2332	);
1896		2333
1897	my $time_watcher; # can only be used once
1898
1899	sub new_timer {
1900	$timer = AnyEvent->timer (after => 1, cb => sub {	2334	my $time_watcher = AnyEvent->timer (after => 1, interval => 1, cb => sub {
1901	warn "timeout\n"; # print 'timeout' about every second	2335	warn "timeout\n"; # print 'timeout' at most every second
1902	&new_timer; # and restart the time
1903	});	2336	});
1904	}
1905
1906	new_timer; # create first timer
1907		2337
1908	$cv->recv; # wait until user enters /^q/i	2338	$cv->recv; # wait until user enters /^q/i
1909		2339
1910	=head1 REAL-WORLD EXAMPLE	2340	=head1 REAL-WORLD EXAMPLE
1911		2341
…		…
1984		2414
1985	The actual code goes further and collects all errors (C<die>s, exceptions)	2415	The actual code goes further and collects all errors (C<die>s, exceptions)
1986	that occurred during request processing. The C<result> method detects	2416	that occurred during request processing. The C<result> method detects
1987	whether an exception as thrown (it is stored inside the $txn object)	2417	whether an exception as thrown (it is stored inside the $txn object)
1988	and just throws the exception, which means connection errors and other	2418	and just throws the exception, which means connection errors and other
1989	problems get reported tot he code that tries to use the result, not in a	2419	problems get reported to the code that tries to use the result, not in a
1990	random callback.	2420	random callback.
1991		2421
1992	All of this enables the following usage styles:	2422	All of this enables the following usage styles:
1993		2423
1994	1. Blocking:	2424	1. Blocking:
…		…
2042	through AnyEvent. The benchmark creates a lot of timers (with a zero	2472	through AnyEvent. The benchmark creates a lot of timers (with a zero
2043	timeout) and I/O watchers (watching STDOUT, a pty, to become writable,	2473	timeout) and I/O watchers (watching STDOUT, a pty, to become writable,
2044	which it is), lets them fire exactly once and destroys them again.	2474	which it is), lets them fire exactly once and destroys them again.
2045		2475
2046	Source code for this benchmark is found as F<eg/bench> in the AnyEvent	2476	Source code for this benchmark is found as F<eg/bench> in the AnyEvent
2047	distribution.	2477	distribution. It uses the L<AE> interface, which makes a real difference
		2478	for the EV and Perl backends only.
2048		2479
2049	=head3 Explanation of the columns	2480	=head3 Explanation of the columns
2050		2481
2051	I<watcher> is the number of event watchers created/destroyed. Since	2482	I<watcher> is the number of event watchers created/destroyed. Since
2052	different event models feature vastly different performances, each event	2483	different event models feature vastly different performances, each event
…		…
2073	watcher.	2504	watcher.
2074		2505
2075	=head3 Results	2506	=head3 Results
2076		2507
2077	name watchers bytes create invoke destroy comment	2508	name watchers bytes create invoke destroy comment
2078	EV/EV 400000 224 0.47 0.35 0.27 EV native interface	2509	EV/EV 100000 223 0.47 0.43 0.27 EV native interface
2079	EV/Any 100000 224 2.88 0.34 0.27 EV + AnyEvent watchers	2510	EV/Any 100000 223 0.48 0.42 0.26 EV + AnyEvent watchers
2080	CoroEV/Any 100000 224 2.85 0.35 0.28 coroutines + Coro::Signal	2511	Coro::EV/Any 100000 223 0.47 0.42 0.26 coroutines + Coro::Signal
2081	Perl/Any 100000 452 4.13 0.73 0.95 pure perl implementation	2512	Perl/Any 100000 431 2.70 0.74 0.92 pure perl implementation
2082	Event/Event 16000 517 32.20 31.80 0.81 Event native interface	2513	Event/Event 16000 516 31.16 31.84 0.82 Event native interface
2083	Event/Any 16000 590 35.85 31.55 1.06 Event + AnyEvent watchers	2514	Event/Any 16000 1203 42.61 34.79 1.80 Event + AnyEvent watchers
2084	IOAsync/Any 16000 989 38.10 32.77 11.13 via IO::Async::Loop::IO_Poll	2515	IOAsync/Any 16000 1911 41.92 27.45 16.81 via IO::Async::Loop::IO_Poll
2085	IOAsync/Any 16000 990 37.59 29.50 10.61 via IO::Async::Loop::Epoll	2516	IOAsync/Any 16000 1726 40.69 26.37 15.25 via IO::Async::Loop::Epoll
2086	Glib/Any 16000 1357 102.33 12.31 51.00 quadratic behaviour	2517	Glib/Any 16000 1118 89.00 12.57 51.17 quadratic behaviour
2087	Tk/Any 2000 1860 27.20 66.31 14.00 SEGV with >> 2000 watchers	2518	Tk/Any 2000 1346 20.96 10.75 8.00 SEGV with >> 2000 watchers
2088	POE/Event 2000 6328 109.99 751.67 14.02 via POE::Loop::Event	2519	POE/Any 2000 6951 108.97 795.32 14.24 via POE::Loop::Event
2089	POE/Select 2000 6027 94.54 809.13 579.80 via POE::Loop::Select	2520	POE/Any 2000 6648 94.79 774.40 575.51 via POE::Loop::Select
2090		2521
2091	=head3 Discussion	2522	=head3 Discussion
2092		2523
2093	The benchmark does I<not> measure scalability of the event loop very	2524	The benchmark does I<not> measure scalability of the event loop very
2094	well. For example, a select-based event loop (such as the pure perl one)	2525	well. For example, a select-based event loop (such as the pure perl one)
…		…
2106	benchmark machine, handling an event takes roughly 1600 CPU cycles with	2537	benchmark machine, handling an event takes roughly 1600 CPU cycles with
2107	EV, 3100 CPU cycles with AnyEvent's pure perl loop and almost 3000000 CPU	2538	EV, 3100 CPU cycles with AnyEvent's pure perl loop and almost 3000000 CPU
2108	cycles with POE.	2539	cycles with POE.
2109		2540
2110	C<EV> is the sole leader regarding speed and memory use, which are both	2541	C<EV> is the sole leader regarding speed and memory use, which are both
2111	maximal/minimal, respectively. Even when going through AnyEvent, it uses	2542	maximal/minimal, respectively. When using the L<AE> API there is zero
		2543	overhead (when going through the AnyEvent API create is about 5-6 times
		2544	slower, with other times being equal, so still uses far less memory than
2112	far less memory than any other event loop and is still faster than Event	2545	any other event loop and is still faster than Event natively).
2113	natively.
2114		2546
2115	The pure perl implementation is hit in a few sweet spots (both the	2547	The pure perl implementation is hit in a few sweet spots (both the
2116	constant timeout and the use of a single fd hit optimisations in the perl	2548	constant timeout and the use of a single fd hit optimisations in the perl
2117	interpreter and the backend itself). Nevertheless this shows that it	2549	interpreter and the backend itself). Nevertheless this shows that it
2118	adds very little overhead in itself. Like any select-based backend its	2550	adds very little overhead in itself. Like any select-based backend its
…		…
2166	(even when used without AnyEvent), but most event loops have acceptable	2598	(even when used without AnyEvent), but most event loops have acceptable
2167	performance with or without AnyEvent.	2599	performance with or without AnyEvent.
2168		2600
2169	=item * The overhead AnyEvent adds is usually much smaller than the overhead of	2601	=item * The overhead AnyEvent adds is usually much smaller than the overhead of
2170	the actual event loop, only with extremely fast event loops such as EV	2602	the actual event loop, only with extremely fast event loops such as EV
2171	adds AnyEvent significant overhead.	2603	does AnyEvent add significant overhead.
2172		2604
2173	=item * You should avoid POE like the plague if you want performance or	2605	=item * You should avoid POE like the plague if you want performance or
2174	reasonable memory usage.	2606	reasonable memory usage.
2175		2607
2176	=back	2608	=back
…		…
2192	In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100	2624	In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100
2193	(1%) are active. This mirrors the activity of large servers with many	2625	(1%) are active. This mirrors the activity of large servers with many
2194	connections, most of which are idle at any one point in time.	2626	connections, most of which are idle at any one point in time.
2195		2627
2196	Source code for this benchmark is found as F<eg/bench2> in the AnyEvent	2628	Source code for this benchmark is found as F<eg/bench2> in the AnyEvent
2197	distribution.	2629	distribution. It uses the L<AE> interface, which makes a real difference
		2630	for the EV and Perl backends only.
2198		2631
2199	=head3 Explanation of the columns	2632	=head3 Explanation of the columns
2200		2633
2201	I<sockets> is the number of sockets, and twice the number of "servers" (as	2634	I<sockets> is the number of sockets, and twice the number of "servers" (as
2202	each server has a read and write socket end).	2635	each server has a read and write socket end).
…		…
2210	a new one that moves the timeout into the future.	2643	a new one that moves the timeout into the future.
2211		2644
2212	=head3 Results	2645	=head3 Results
2213		2646
2214	name sockets create request	2647	name sockets create request
2215	EV 20000 69.01 11.16	2648	EV 20000 62.66 7.99
2216	Perl 20000 73.32 35.87	2649	Perl 20000 68.32 32.64
2217	IOAsync 20000 157.00 98.14 epoll	2650	IOAsync 20000 174.06 101.15 epoll
2218	IOAsync 20000 159.31 616.06 poll	2651	IOAsync 20000 174.67 610.84 poll
2219	Event 20000 212.62 257.32	2652	Event 20000 202.69 242.91
2220	Glib 20000 651.16 1896.30	2653	Glib 20000 557.01 1689.52
2221	POE 20000 349.67 12317.24 uses POE::Loop::Event	2654	POE 20000 341.54 12086.32 uses POE::Loop::Event
2222		2655
2223	=head3 Discussion	2656	=head3 Discussion
2224		2657
2225	This benchmark I<does> measure scalability and overall performance of the	2658	This benchmark I<does> measure scalability and overall performance of the
2226	particular event loop.	2659	particular event loop.
…		…
2352	As you can see, the AnyEvent + EV combination even beats the	2785	As you can see, the AnyEvent + EV combination even beats the
2353	hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl	2786	hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl
2354	backend easily beats IO::Lambda and POE.	2787	backend easily beats IO::Lambda and POE.
2355		2788
2356	And even the 100% non-blocking version written using the high-level (and	2789	And even the 100% non-blocking version written using the high-level (and
2357	slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda by a	2790	slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda
2358	large margin, even though it does all of DNS, tcp-connect and socket I/O	2791	higher level ("unoptimised") abstractions by a large margin, even though
2359	in a non-blocking way.	2792	it does all of DNS, tcp-connect and socket I/O in a non-blocking way.
2360		2793
2361	The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and	2794	The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and
2362	F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are	2795	F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are
2363	part of the IO::lambda distribution and were used without any changes.	2796	part of the IO::Lambda distribution and were used without any changes.
2364		2797
2365		2798
2366	=head1 SIGNALS	2799	=head1 SIGNALS
2367		2800
2368	AnyEvent currently installs handlers for these signals:	2801	AnyEvent currently installs handlers for these signals:
…		…
2405	unless defined $SIG{PIPE};	2838	unless defined $SIG{PIPE};
2406		2839
2407	=head1 RECOMMENDED/OPTIONAL MODULES	2840	=head1 RECOMMENDED/OPTIONAL MODULES
2408		2841
2409	One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and	2842	One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and
2410	it's built-in modules) are required to use it.	2843	its built-in modules) are required to use it.
2411		2844
2412	That does not mean that AnyEvent won't take advantage of some additional	2845	That does not mean that AnyEvent won't take advantage of some additional
2413	modules if they are installed.	2846	modules if they are installed.
2414		2847
2415	This section epxlains which additional modules will be used, and how they	2848	This section explains which additional modules will be used, and how they
2416	affect AnyEvent's operetion.	2849	affect AnyEvent's operation.
2417		2850
2418	=over 4	2851	=over 4
2419		2852
2420	=item L<Async::Interrupt>	2853	=item L<Async::Interrupt>
2421		2854
…		…
2426	catch the signals) with some delay (default is 10 seconds, look for	2859	catch the signals) with some delay (default is 10 seconds, look for
2427	C<$AnyEvent::MAX_SIGNAL_LATENCY>).	2860	C<$AnyEvent::MAX_SIGNAL_LATENCY>).
2428		2861
2429	If this module is available, then it will be used to implement signal	2862	If this module is available, then it will be used to implement signal
2430	catching, which means that signals will not be delayed, and the event loop	2863	catching, which means that signals will not be delayed, and the event loop
2431	will not be interrupted regularly, which is more efficient (And good for	2864	will not be interrupted regularly, which is more efficient (and good for
2432	battery life on laptops).	2865	battery life on laptops).
2433		2866
2434	This affects not just the pure-perl event loop, but also other event loops	2867	This affects not just the pure-perl event loop, but also other event loops
2435	that have no signal handling on their own (e.g. Glib, Tk, Qt).	2868	that have no signal handling on their own (e.g. Glib, Tk, Qt).
2436		2869
…		…
2448	automatic timer adjustments even when no monotonic clock is available,	2881	automatic timer adjustments even when no monotonic clock is available,
2449	can take avdantage of advanced kernel interfaces such as C<epoll> and	2882	can take avdantage of advanced kernel interfaces such as C<epoll> and
2450	C<kqueue>, and is the fastest backend I<by far>. You can even embed	2883	C<kqueue>, and is the fastest backend I<by far>. You can even embed
2451	L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>).	2884	L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>).
2452		2885
		2886	If you only use backends that rely on another event loop (e.g. C<Tk>),
		2887	then this module will do nothing for you.
		2888
2453	=item L<Guard>	2889	=item L<Guard>
2454		2890
2455	The guard module, when used, will be used to implement	2891	The guard module, when used, will be used to implement
2456	C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a	2892	C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a
2457	lot less memory), but otherwise doesn't affect guard operation much. It is	2893	lot less memory), but otherwise doesn't affect guard operation much. It is
2458	purely used for performance.	2894	purely used for performance.
2459		2895
2460	=item L<JSON> and L<JSON::XS>	2896	=item L<JSON> and L<JSON::XS>
2461		2897
2462	This module is required when you want to read or write JSON data via	2898	One of these modules is required when you want to read or write JSON data
2463	L<AnyEvent::Handle>. It is also written in pure-perl, but can take	2899	via L<AnyEvent::Handle>. L<JSON> is also written in pure-perl, but can take
2464	advantage of the ultra-high-speed L<JSON::XS> module when it is installed.	2900	advantage of the ultra-high-speed L<JSON::XS> module when it is installed.
2465
2466	In fact, L<AnyEvent::Handle> will use L<JSON::XS> by default if it is
2467	installed.
2468		2901
2469	=item L<Net::SSLeay>	2902	=item L<Net::SSLeay>
2470		2903
2471	Implementing TLS/SSL in Perl is certainly interesting, but not very	2904	Implementing TLS/SSL in Perl is certainly interesting, but not very
2472	worthwhile: If this module is installed, then L<AnyEvent::Handle> (with	2905	worthwhile: If this module is installed, then L<AnyEvent::Handle> (with
2473	the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL.	2906	the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL.
2474		2907
2475	=item L<Time::HiRes>	2908	=item L<Time::HiRes>
2476		2909
2477	This module is part of perl since release 5.008. It will be used when the	2910	This module is part of perl since release 5.008. It will be used when the
2478	chosen event library does not come with a timing source on it's own. The	2911	chosen event library does not come with a timing source of its own. The
2479	pure-perl event loop (L<AnyEvent::Impl::Perl>) will additionally use it to	2912	pure-perl event loop (L<AnyEvent::Loop>) will additionally load it to
2480	try to use a monotonic clock for timing stability.	2913	try to use a monotonic clock for timing stability.
2481		2914
2482	=back	2915	=back
2483		2916
2484		2917
2485	=head1 FORK	2918	=head1 FORK
2486		2919
2487	Most event libraries are not fork-safe. The ones who are usually are	2920	Most event libraries are not fork-safe. The ones who are usually are
2488	because they rely on inefficient but fork-safe C<select> or C<poll>	2921	because they rely on inefficient but fork-safe C<select> or C<poll> calls
2489	calls. Only L<EV> is fully fork-aware.	2922	- higher performance APIs such as BSD's kqueue or the dreaded Linux epoll
		2923	are usually badly thought-out hacks that are incompatible with fork in
		2924	one way or another. Only L<EV> is fully fork-aware and ensures that you
		2925	continue event-processing in both parent and child (or both, if you know
		2926	what you are doing).
		2927
		2928	This means that, in general, you cannot fork and do event processing in
		2929	the child if the event library was initialised before the fork (which
		2930	usually happens when the first AnyEvent watcher is created, or the library
		2931	is loaded).
2490		2932
2491	If you have to fork, you must either do so I<before> creating your first	2933	If you have to fork, you must either do so I<before> creating your first
2492	watcher OR you must not use AnyEvent at all in the child OR you must do	2934	watcher OR you must not use AnyEvent at all in the child OR you must do
2493	something completely out of the scope of AnyEvent.	2935	something completely out of the scope of AnyEvent.
		2936
		2937	The problem of doing event processing in the parent I<and> the child
		2938	is much more complicated: even for backends that I<are> fork-aware or
		2939	fork-safe, their behaviour is not usually what you want: fork clones all
		2940	watchers, that means all timers, I/O watchers etc. are active in both
		2941	parent and child, which is almost never what you want. USing C<exec>
		2942	to start worker children from some kind of manage rprocess is usually
		2943	preferred, because it is much easier and cleaner, at the expense of having
		2944	to have another binary.
2494		2945
2495		2946
2496	=head1 SECURITY CONSIDERATIONS	2947	=head1 SECURITY CONSIDERATIONS
2497		2948
2498	AnyEvent can be forced to load any event model via	2949	AnyEvent can be forced to load any event model via
…		…
2528	pronounced).	2979	pronounced).
2529		2980
2530		2981
2531	=head1 SEE ALSO	2982	=head1 SEE ALSO
2532		2983
2533	Utility functions: L<AnyEvent::Util>.	2984	Tutorial/Introduction: L<AnyEvent::Intro>.
2534		2985
2535	Event modules: L<EV>, L<EV::Glib>, L<Glib::EV>, L<Event>, L<Glib::Event>,	2986	FAQ: L<AnyEvent::FAQ>.
2536	L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.	2987
		2988	Utility functions: L<AnyEvent::Util> (misc. grab-bag), L<AnyEvent::Log>
		2989	(simply logging).
		2990
		2991	Development/Debugging: L<AnyEvent::Strict> (stricter checking),
		2992	L<AnyEvent::Debug> (interactive shell, watcher tracing).
		2993
		2994	Supported event modules: L<AnyEvent::Loop>, L<EV>, L<EV::Glib>,
		2995	L<Glib::EV>, L<Event>, L<Glib::Event>, L<Glib>, L<Tk>, L<Event::Lib>,
		2996	L<Qt>, L<POE>, L<FLTK>.
2537		2997
2538	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,	2998	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,
2539	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,	2999	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,
2540	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,	3000	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,
2541	L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>, L<Anyevent::Impl::Irssi>.	3001	L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>, L<Anyevent::Impl::Irssi>,
		3002	L<AnyEvent::Impl::FLTK>.
2542		3003
2543	Non-blocking file handles, sockets, TCP clients and	3004	Non-blocking handles, pipes, stream sockets, TCP clients and
2544	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.	3005	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.
2545		3006
2546	Asynchronous DNS: L<AnyEvent::DNS>.	3007	Asynchronous DNS: L<AnyEvent::DNS>.
2547		3008
2548	Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>,	3009	Thread support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>.
2549	L<Coro::Event>,
2550		3010
2551	Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::XMPP>,	3011	Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::IRC>,
2552	L<AnyEvent::HTTP>.	3012	L<AnyEvent::HTTP>.
2553		3013
2554		3014
2555	=head1 AUTHOR	3015	=head1 AUTHOR
2556		3016

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