[ViewVC] Diff of: cvs/AnyEvent/lib/AnyEvent.pm

Comparing AnyEvent/lib/AnyEvent.pm (file contents):
Revision 1.299 by root, Tue Dec 1 17:53:48 2009 UTC vs.
Revision 1.396 by root, Sat Mar 10 17:36:24 2012 UTC

…		…
1	=head1 NAME	1	=head1 NAME
2		2
3	AnyEvent - the DBI of event loop programming	3	AnyEvent - the DBI of event loop programming
4		4
5	EV, Event, Glib, Tk, Perl, Event::Lib, Irssi, rxvt-unicode, IO::Async, Qt	5	EV, Event, Glib, Tk, Perl, Event::Lib, Irssi, rxvt-unicode, IO::Async, Qt,
6	and POE are various supported event loops/environments.	6	FLTK and POE are various supported event loops/environments.
7		7
8	=head1 SYNOPSIS	8	=head1 SYNOPSIS
9		9
10	use AnyEvent;	10	use AnyEvent;
11		11
		12	# if you prefer function calls, look at the AE manpage for
		13	# an alternative API.
		14
12	# file descriptor readable	15	# file handle or descriptor readable
13	my $w = AnyEvent->io (fh => $fh, poll => "r", cb => sub { ... });	16	my $w = AnyEvent->io (fh => $fh, poll => "r", cb => sub { ... });
14		17
15	# one-shot or repeating timers	18	# one-shot or repeating timers
16	my $w = AnyEvent->timer (after => $seconds, cb => sub { ... });	19	my $w = AnyEvent->timer (after => $seconds, cb => sub { ... });
17	my $w = AnyEvent->timer (after => $seconds, interval => $seconds, cb => ...	20	my $w = AnyEvent->timer (after => $seconds, interval => $seconds, cb => ...);
18		21
19	print AnyEvent->now; # prints current event loop time	22	print AnyEvent->now; # prints current event loop time
20	print AnyEvent->time; # think Time::HiRes::time or simply CORE::time.	23	print AnyEvent->time; # think Time::HiRes::time or simply CORE::time.
21		24
22	# POSIX signal	25	# POSIX signal
43	in a tutorial or some gentle introduction, have a look at the	46	in a tutorial or some gentle introduction, have a look at the
44	L<AnyEvent::Intro> manpage.	47	L<AnyEvent::Intro> manpage.
45		48
46	=head1 SUPPORT	49	=head1 SUPPORT
47		50
		51	An FAQ document is available as L<AnyEvent::FAQ>.
		52
48	There is a mailinglist for discussing all things AnyEvent, and an IRC	53	There also is a mailinglist for discussing all things AnyEvent, and an IRC
49	channel, too.	54	channel, too.
50		55
51	See the AnyEvent project page at the B<Schmorpforge Ta-Sa Software	56	See the AnyEvent project page at the B<Schmorpforge Ta-Sa Software
52	Repository>, at L<http://anyevent.schmorp.de>, for more info.	57	Repository>, at L<http://anyevent.schmorp.de>, for more info.
53		58
…		…
73	module users into the same thing by forcing them to use the same event	78	module users into the same thing by forcing them to use the same event
74	model you use.	79	model you use.
75		80
76	For modules like POE or IO::Async (which is a total misnomer as it is	81	For modules like POE or IO::Async (which is a total misnomer as it is
77	actually doing all I/O I<synchronously>...), using them in your module is	82	actually doing all I/O I<synchronously>...), using them in your module is
78	like joining a cult: After you joined, you are dependent on them and you	83	like joining a cult: After you join, you are dependent on them and you
79	cannot use anything else, as they are simply incompatible to everything	84	cannot use anything else, as they are simply incompatible to everything
80	that isn't them. What's worse, all the potential users of your	85	that isn't them. What's worse, all the potential users of your
81	module are I<also> forced to use the same event loop you use.	86	module are I<also> forced to use the same event loop you use.
82		87
83	AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works	88	AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works
84	fine. AnyEvent + Tk works fine etc. etc. but none of these work together	89	fine. AnyEvent + Tk works fine etc. etc. but none of these work together
85	with the rest: POE + IO::Async? No go. Tk + Event? No go. Again: if	90	with the rest: POE + EV? No go. Tk + Event? No go. Again: if your module
86	your module uses one of those, every user of your module has to use it,	91	uses one of those, every user of your module has to use it, too. But if
87	too. But if your module uses AnyEvent, it works transparently with all	92	your module uses AnyEvent, it works transparently with all event models it
88	event models it supports (including stuff like IO::Async, as long as those	93	supports (including stuff like IO::Async, as long as those use one of the
89	use one of the supported event loops. It is trivial to add new event loops	94	supported event loops. It is easy to add new event loops to AnyEvent, too,
90	to AnyEvent, too, so it is future-proof).	95	so it is future-proof).
91		96
92	In addition to being free of having to use I<the one and only true event	97	In addition to being free of having to use I<the one and only true event
93	model>, AnyEvent also is free of bloat and policy: with POE or similar	98	model>, AnyEvent also is free of bloat and policy: with POE or similar
94	modules, you get an enormous amount of code and strict rules you have to	99	modules, you get an enormous amount of code and strict rules you have to
95	follow. AnyEvent, on the other hand, is lean and up to the point, by only	100	follow. AnyEvent, on the other hand, is lean and to the point, by only
96	offering the functionality that is necessary, in as thin as a wrapper as	101	offering the functionality that is necessary, in as thin as a wrapper as
97	technically possible.	102	technically possible.
98		103
99	Of course, AnyEvent comes with a big (and fully optional!) toolbox	104	Of course, AnyEvent comes with a big (and fully optional!) toolbox
100	of useful functionality, such as an asynchronous DNS resolver, 100%	105	of useful functionality, such as an asynchronous DNS resolver, 100%
…		…
106	useful) and you want to force your users to use the one and only event	111	useful) and you want to force your users to use the one and only event
107	model, you should I<not> use this module.	112	model, you should I<not> use this module.
108		113
109	=head1 DESCRIPTION	114	=head1 DESCRIPTION
110		115
111	L<AnyEvent> provides an identical interface to multiple event loops. This	116	L<AnyEvent> provides a uniform interface to various event loops. This
112	allows module authors to utilise an event loop without forcing module	117	allows module authors to use event loop functionality without forcing
113	users to use the same event loop (as only a single event loop can coexist	118	module users to use a specific event loop implementation (since more
114	peacefully at any one time).	119	than one event loop cannot coexist peacefully).
115		120
116	The interface itself is vaguely similar, but not identical to the L<Event>	121	The interface itself is vaguely similar, but not identical to the L<Event>
117	module.	122	module.
118		123
119	During the first call of any watcher-creation method, the module tries	124	During the first call of any watcher-creation method, the module tries
120	to detect the currently loaded event loop by probing whether one of the	125	to detect the currently loaded event loop by probing whether one of the
121	following modules is already loaded: L<EV>,	126	following modules is already loaded: L<EV>, L<AnyEvent::Loop>,
122	L<Event>, L<Glib>, L<AnyEvent::Impl::Perl>, L<Tk>, L<Event::Lib>, L<Qt>,	127	L<Event>, L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>. The first one
123	L<POE>. The first one found is used. If none are found, the module tries	128	found is used. If none are detected, the module tries to load the first
124	to load these modules (excluding Tk, Event::Lib, Qt and POE as the pure perl	129	four modules in the order given; but note that if L<EV> is not
125	adaptor should always succeed) in the order given. The first one that can	130	available, the pure-perl L<AnyEvent::Loop> should always work, so
126	be successfully loaded will be used. If, after this, still none could be	131	the other two are not normally tried.
127	found, AnyEvent will fall back to a pure-perl event loop, which is not
128	very efficient, but should work everywhere.
129		132
130	Because AnyEvent first checks for modules that are already loaded, loading	133	Because AnyEvent first checks for modules that are already loaded, loading
131	an event model explicitly before first using AnyEvent will likely make	134	an event model explicitly before first using AnyEvent will likely make
132	that model the default. For example:	135	that model the default. For example:
133		136
…		…
135	use AnyEvent;	138	use AnyEvent;
136		139
137	# .. AnyEvent will likely default to Tk	140	# .. AnyEvent will likely default to Tk
138		141
139	The I<likely> means that, if any module loads another event model and	142	The I<likely> means that, if any module loads another event model and
140	starts using it, all bets are off. Maybe you should tell their authors to	143	starts using it, all bets are off - this case should be very rare though,
141	use AnyEvent so their modules work together with others seamlessly...	144	as very few modules hardcode event loops without announcing this very
		145	loudly.
142		146
143	The pure-perl implementation of AnyEvent is called	147	The pure-perl implementation of AnyEvent is called C<AnyEvent::Loop>. Like
144	C<AnyEvent::Impl::Perl>. Like other event modules you can load it	148	other event modules you can load it explicitly and enjoy the high
145	explicitly and enjoy the high availability of that event loop :)	149	availability of that event loop :)
146		150
147	=head1 WATCHERS	151	=head1 WATCHERS
148		152
149	AnyEvent has the central concept of a I<watcher>, which is an object that	153	AnyEvent has the central concept of a I<watcher>, which is an object that
150	stores relevant data for each kind of event you are waiting for, such as	154	stores relevant data for each kind of event you are waiting for, such as
…		…
155	callback when the event occurs (of course, only when the event model	159	callback when the event occurs (of course, only when the event model
156	is in control).	160	is in control).
157		161
158	Note that B<callbacks must not permanently change global variables>	162	Note that B<callbacks must not permanently change global variables>
159	potentially in use by the event loop (such as C<$_> or C<$[>) and that B<<	163	potentially in use by the event loop (such as C<$_> or C<$[>) and that B<<
160	callbacks must not C<die> >>. The former is good programming practise in	164	callbacks must not C<die> >>. The former is good programming practice in
161	Perl and the latter stems from the fact that exception handling differs	165	Perl and the latter stems from the fact that exception handling differs
162	widely between event loops.	166	widely between event loops.
163		167
164	To disable the watcher you have to destroy it (e.g. by setting the	168	To disable a watcher you have to destroy it (e.g. by setting the
165	variable you store it in to C<undef> or otherwise deleting all references	169	variable you store it in to C<undef> or otherwise deleting all references
166	to it).	170	to it).
167		171
168	All watchers are created by calling a method on the C<AnyEvent> class.	172	All watchers are created by calling a method on the C<AnyEvent> class.
169		173
170	Many watchers either are used with "recursion" (repeating timers for	174	Many watchers either are used with "recursion" (repeating timers for
171	example), or need to refer to their watcher object in other ways.	175	example), or need to refer to their watcher object in other ways.
172		176
173	An any way to achieve that is this pattern:	177	One way to achieve that is this pattern:
174		178
175	my $w; $w = AnyEvent->type (arg => value ..., cb => sub {	179	my $w; $w = AnyEvent->type (arg => value ..., cb => sub {
176	# you can use $w here, for example to undef it	180	# you can use $w here, for example to undef it
177	undef $w;	181	undef $w;
178	});	182	});
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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 {
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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.
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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
…		…
411	not restart syscalls (that includes L<Async::Interrupt> and AnyEvent's	415	not restart syscalls (that includes L<Async::Interrupt> and AnyEvent's
412	pure perl implementation).	416	pure perl implementation).
413		417
414	=head3 Safe/Unsafe Signals	418	=head3 Safe/Unsafe Signals
415		419
416	Perl signals can be either "safe" (synchronous to opcode handling) or	420	Perl signals can be either "safe" (synchronous to opcode handling)
417	"unsafe" (asynchronous) - the former might get delayed indefinitely, the	421	or "unsafe" (asynchronous) - the former might delay signal delivery
418	latter might corrupt your memory.	422	indefinitely, the latter might corrupt your memory.
419		423
420	AnyEvent signal handlers are, in addition, synchronous to the event loop,	424	AnyEvent signal handlers are, in addition, synchronous to the event loop,
421	i.e. they will not interrupt your running perl program but will only be	425	i.e. they will not interrupt your running perl program but will only be
422	called as part of the normal event handling (just like timer, I/O etc.	426	called as part of the normal event handling (just like timer, I/O etc.
423	callbacks, too).	427	callbacks, too).
424		428
425	=head3 Signal Races, Delays and Workarounds	429	=head3 Signal Races, Delays and Workarounds
426		430
427	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
428	callbacks to signals in a generic way, which is a pity, as you cannot	432	attaching callbacks to signals in a generic way, which is a pity,
429	do race-free signal handling in perl, requiring C libraries for	433	as you cannot do race-free signal handling in perl, requiring
430	this. AnyEvent will try to do it's best, which means in some cases,	434	C libraries for this. AnyEvent will try to do its best, which
431	signals will be delayed. The maximum time a signal might be delayed is	435	means in some cases, signals will be delayed. The maximum time
432	specified in C<$AnyEvent::MAX_SIGNAL_LATENCY> (default: 10 seconds). This	436	a signal might be delayed is 10 seconds by default, but can
433	variable can be changed only before the first signal watcher is created,	437	be overriden via C<$ENV{PERL_ANYEVENT_MAX_SIGNAL_LATENCY}> or
434	and should be left alone otherwise. This variable determines how often	438	C<$AnyEvent::MAX_SIGNAL_LATENCY> - see the L<ENVIRONMENT VARIABLES>
435	AnyEvent polls for signals (in case a wake-up was missed). Higher values	439	section for details.
436	will cause fewer spurious wake-ups, which is better for power and CPU
437	saving.
438		440
439	All these problems can be avoided by installing the optional	441	All these problems can be avoided by installing the optional
440	L<Async::Interrupt> module, which works with most event loops. It will not	442	L<Async::Interrupt> module, which works with most event loops. It will not
441	work with inherently broken event loops such as L<Event> or L<Event::Lib>	443	work with inherently broken event loops such as L<Event> or L<Event::Lib>
442	(and not with L<POE> currently, as POE does it's own workaround with	444	(and not with L<POE> currently). For those, you just have to suffer the
443	one-second latency). For those, you just have to suffer the delays.	445	delays.
444		446
445	=head2 CHILD PROCESS WATCHERS	447	=head2 CHILD PROCESS WATCHERS
446		448
447	$w = AnyEvent->child (pid => <process id>, cb => <callback>);	449	$w = AnyEvent->child (pid => <process id>, cb => <callback>);
448		450
449	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.
450		452
451	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,
452	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
453	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
454	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
455	(stopped/continued).	457	(stopped/continued).
456		458
…		…
478	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
479	watcher before you C<fork> the child (alternatively, you can call	481	watcher before you C<fork> the child (alternatively, you can call
480	C<AnyEvent::detect>).	482	C<AnyEvent::detect>).
481		483
482	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
483	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
484	mentioned in the description of signal watchers apply.	486	problems mentioned in the description of signal watchers apply.
485		487
486	Example: fork a process and wait for it	488	Example: fork a process and wait for it
487		489
488	my $done = AnyEvent->condvar;	490	my $done = AnyEvent->condvar;
489		491
…		…
503		505
504	=head2 IDLE WATCHERS	506	=head2 IDLE WATCHERS
505		507
506	$w = AnyEvent->idle (cb => <callback>);	508	$w = AnyEvent->idle (cb => <callback>);
507		509
508	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,
509	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.
510	"nothing better to do" is usually defined to be "no other events need
511	attention by the event loop".
512		512
513	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
514	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
515	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.
516		521
517	Most event loops unfortunately do not really support idle watchers (only	522	Unfortunately, most event loops do not really support idle watchers (only
518	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
519	will simply call the callback "from time to time".	524	will simply call the callback "from time to time".
520		525
521	Example: read lines from STDIN, but only process them when the	526	Example: read lines from STDIN, but only process them when the
522	program is otherwise idle:	527	program is otherwise idle:
…		…
550	will actively watch for new events and call your callbacks.	555	will actively watch for new events and call your callbacks.
551		556
552	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
553	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).
554		559
555	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
556	because they represent a condition that must become true.	561	they represent a condition that must become true.
557		562
558	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.
559		564
560	Condition variables can be created by calling the C<< AnyEvent->condvar	565	Condition variables can be created by calling the C<< AnyEvent->condvar
561	>> method, usually without arguments. The only argument pair allowed is	566	>> method, usually without arguments. The only argument pair allowed is
…		…
566	After creation, the condition variable is "false" until it becomes "true"	571	After creation, the condition variable is "false" until it becomes "true"
567	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
568	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<<
569	->send >> method).	574	->send >> method).
570		575
571	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
572	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:
573	in time where multiple outstanding events have been processed. And yet	578
574	another way to call them is transactions - each condition variable can be	579	=over 4
575	used to represent a transaction, which finishes at some point and delivers	580
576	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
577	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
578		599
579	Condition variables are very useful to signal that something has finished,	600	Condition variables are very useful to signal that something has finished,
580	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,
581	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
582	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
…		…
595		616
596	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
597	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
598	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
599	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
600	it's C<new> method in your own C<new> method.	621	its C<new> method in your own C<new> method.
601		622
602	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
603	eventually calls C<< -> send >>, and the "consumer side", which waits	624	eventually calls C<< -> send >>, and the "consumer side", which waits
604	for the send to occur.	625	for the send to occur.
605		626
606	Example: wait for a timer.	627	Example: wait for a timer.
607		628
608	# wait till the result is ready	629	# condition: "wait till the timer is fired"
609	my $result_ready = AnyEvent->condvar;	630	my $timer_fired = AnyEvent->condvar;
610		631
611	# do something such as adding a timer	632	# create the timer - we could wait for, say
612	# or socket watcher the calls $result_ready->send	633	# a handle becomign ready, or even an
613	# when the "result" is ready.	634	# AnyEvent::HTTP request to finish, but
614	# in this case, we simply use a timer:	635	# in this case, we simply use a timer:
615	my $w = AnyEvent->timer (	636	my $w = AnyEvent->timer (
616	after => 1,	637	after => 1,
617	cb => sub { $result_ready->send },	638	cb => sub { $timer_fired->send },
618	);	639	);
619		640
620	# this "blocks" (while handling events) till the callback	641	# this "blocks" (while handling events) till the callback
621	# calls ->send	642	# calls ->send
622	$result_ready->recv;	643	$timer_fired->recv;
623		644
624	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
625	variables are also callable directly.	646	variables are also callable directly.
626		647
627	my $done = AnyEvent->condvar;	648	my $done = AnyEvent->condvar;
…		…
670	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
671	C<send>.	692	C<send>.
672		693
673	=item $cv->croak ($error)	694	=item $cv->croak ($error)
674		695
675	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
676	C<Carp::croak> with the given error message/object/scalar.	697	C<Carp::croak> with the given error message/object/scalar.
677		698
678	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
679	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
680	delays the error detetcion, but has the overwhelmign advantage that it	701	delays the error detection, but has the overwhelming advantage that it
681	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
682	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
683	the problem.	704	the problem.
684		705
685	=item $cv->begin ([group callback])	706	=item $cv->begin ([group callback])
686		707
687	=item $cv->end	708	=item $cv->end
…		…
725	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
726	sending.	747	sending.
727		748
728	The ping example mentioned above is slightly more complicated, as the	749	The ping example mentioned above is slightly more complicated, as the
729	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
730	begung can potentially be zero:	751	begun can potentially be zero:
731		752
732	my $cv = AnyEvent->condvar;	753	my $cv = AnyEvent->condvar;
733		754
734	my %result;	755	my %result;
735	$cv->begin (sub { shift->send (\%result) });	756	$cv->begin (sub { shift->send (\%result) });
…		…
756	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
757	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
758	doesn't execute once).	779	doesn't execute once).
759		780
760	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
761	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
762	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
763	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,
764	call C<end>.	785	call C<end>.
765		786
766	=back	787	=back
…		…
773	=over 4	794	=over 4
774		795
775	=item $cv->recv	796	=item $cv->recv
776		797
777	Wait (blocking if necessary) until the C<< ->send >> or C<< ->croak	798	Wait (blocking if necessary) until the C<< ->send >> or C<< ->croak
778	>> methods have been called on c<$cv>, while servicing other watchers	799	>> methods have been called on C<$cv>, while servicing other watchers
779	normally.	800	normally.
780		801
781	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
782	will return immediately.	803	will return immediately.
783		804
…		…
800	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
801	condition variables with some kind of request results and supporting	822	condition variables with some kind of request results and supporting
802	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,
803	while still supporting blocking waits if the caller so desires).	824	while still supporting blocking waits if the caller so desires).
804		825
805	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
806	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
807	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
808	waits otherwise.	829	waits otherwise.
809		830
810	=item $bool = $cv->ready	831	=item $bool = $cv->ready
…		…
815	=item $cb = $cv->cb ($cb->($cv))	836	=item $cb = $cv->cb ($cb->($cv))
816		837
817	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
818	replaces it before doing so.	839	replaces it before doing so.
819		840
820	The callback will be called when the condition becomes (or already was)	841	The callback will be called when the condition becomes "true", i.e. when
821	"true", i.e. when C<send> or C<croak> are called (or were called), with	842	C<send> or C<croak> are called, with the only argument being the
822	the only argument being the condition variable itself. Calling C<recv>	843	condition variable itself. If the condition is already true, the
		844	callback is called immediately when it is set. Calling C<recv> inside
823	inside the callback or at any later time is guaranteed not to block.	845	the callback or at any later time is guaranteed not to block.
824		846
825	=back	847	=back
826		848
827	=head1 SUPPORTED EVENT LOOPS/BACKENDS	849	=head1 SUPPORTED EVENT LOOPS/BACKENDS
828		850
…		…
836	use. If EV is not installed, then AnyEvent will fall back to its own	858	use. If EV is not installed, then AnyEvent will fall back to its own
837	pure-perl implementation, which is available everywhere as it comes with	859	pure-perl implementation, which is available everywhere as it comes with
838	AnyEvent itself.	860	AnyEvent itself.
839		861
840	AnyEvent::Impl::EV based on EV (interface to libev, best choice).	862	AnyEvent::Impl::EV based on EV (interface to libev, best choice).
841	AnyEvent::Impl::Perl pure-perl implementation, fast and portable.	863	AnyEvent::Impl::Perl pure-perl AnyEvent::Loop, fast and portable.
842		864
843	=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.
844		866
845	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
846	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
847	them. This means that AnyEvent will automatically pick the right backend	869	them. This means that AnyEvent will automatically pick the right backend
848	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
849	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.
850		872
…		…
852	AnyEvent::Impl::Glib based on Glib, slow but very stable.	874	AnyEvent::Impl::Glib based on Glib, slow but very stable.
853	AnyEvent::Impl::Tk based on Tk, very broken.	875	AnyEvent::Impl::Tk based on Tk, very broken.
854	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.	876	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
855	AnyEvent::Impl::POE based on POE, very slow, some limitations.	877	AnyEvent::Impl::POE based on POE, very slow, some limitations.
856	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).
857		882
858	=item Backends with special needs.	883	=item Backends with special needs.
859		884
860	Qt requires the Qt::Application to be instantiated first, but will	885	Qt requires the Qt::Application to be instantiated first, but will
861	otherwise be picked up automatically. As long as the main program	886	otherwise be picked up automatically. As long as the main program
862	instantiates the application before any AnyEvent watchers are created,	887	instantiates the application before any AnyEvent watchers are created,
863	everything should just work.	888	everything should just work.
864		889
865	AnyEvent::Impl::Qt based on Qt.	890	AnyEvent::Impl::Qt based on Qt.
866		891
867	Support for IO::Async can only be partial, as it is too broken and
868	architecturally limited to even support the AnyEvent API. It also
869	is the only event loop that needs the loop to be set explicitly, so
870	it can only be used by a main program knowing about AnyEvent. See
871	L<AnyEvent::Impl::Async> for the gory details.
872
873	AnyEvent::Impl::IOAsync based on IO::Async, cannot be autoprobed.
874
875	=item Event loops that are indirectly supported via other backends.	892	=item Event loops that are indirectly supported via other backends.
876		893
877	Some event loops can be supported via other modules:	894	Some event loops can be supported via other modules:
878		895
879	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>.
…		…
904	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
905	backend has been autodetected.	922	backend has been autodetected.
906		923
907	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
908	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
909	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
910	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
911	will be C<urxvt::anyevent>).	928	will be C<urxvt::anyevent>).
912		929
913	=item AnyEvent::detect	930	=item AnyEvent::detect
914		931
915	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model	932	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model
916	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
917	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
918	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).
919		940
920	If you need to do some initialisation before AnyEvent watchers are	941	If you need to do some initialisation before AnyEvent watchers are
921	created, use C<post_detect>.	942	created, use C<post_detect>.
922		943
923	=item $guard = AnyEvent::post_detect { BLOCK }	944	=item $guard = AnyEvent::post_detect { BLOCK }
924		945
925	Arranges for the code block to be executed as soon as the event model is	946	Arranges for the code block to be executed as soon as the event model is
926	autodetected (or immediately if this has already happened).	947	autodetected (or immediately if that has already happened).
927		948
928	The block will be executed I<after> the actual backend has been detected	949	The block will be executed I<after> the actual backend has been detected
929	(C<$AnyEvent::MODEL> is set), but I<before> any watchers have been	950	(C<$AnyEvent::MODEL> is set), but I<before> any watchers have been
930	created, so it is possible to e.g. patch C<@AnyEvent::ISA> or do	951	created, so it is possible to e.g. patch C<@AnyEvent::ISA> or do
931	other initialisations - see the sources of L<AnyEvent::Strict> or	952	other initialisations - see the sources of L<AnyEvent::Strict> or
…		…
940	that automatically removes the callback again when it is destroyed (or	961	that automatically removes the callback again when it is destroyed (or
941	C<undef> when the hook was immediately executed). See L<AnyEvent::AIO> for	962	C<undef> when the hook was immediately executed). See L<AnyEvent::AIO> for
942	a case where this is useful.	963	a case where this is useful.
943		964
944	Example: Create a watcher for the IO::AIO module and store it in	965	Example: Create a watcher for the IO::AIO module and store it in
945	C<$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.
946		967
947	our WATCHER;	968	our WATCHER;
948		969
949	my $guard = AnyEvent::post_detect {	970	my $guard = AnyEvent::post_detect {
950	$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);
…		…
958	$WATCHER \|\|= $guard;	979	$WATCHER \|\|= $guard;
959		980
960	=item @AnyEvent::post_detect	981	=item @AnyEvent::post_detect
961		982
962	If there are any code references in this array (you can C<push> to it	983	If there are any code references in this array (you can C<push> to it
963	before or after loading AnyEvent), then they will called directly after	984	before or after loading AnyEvent), then they will be called directly
964	the event loop has been chosen.	985	after the event loop has been chosen.
965		986
966	You should check C<$AnyEvent::MODEL> before adding to this array, though:	987	You should check C<$AnyEvent::MODEL> before adding to this array, though:
967	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
968	array will be ignored.	989	array will be ignored.
969		990
970	Best use C<AnyEvent::post_detect { BLOCK }> when your application allows	991	Best use C<AnyEvent::post_detect { BLOCK }> when your application allows
971	it,as it takes care of these details.	992	it, as it takes care of these details.
972		993
973	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
974	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
975	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
976	into AnyEvent passively, without loading it.	997	into AnyEvent passively, without loading it.
977		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
978	=back	1070	=back
979		1071
980	=head1 WHAT TO DO IN A MODULE	1072	=head1 WHAT TO DO IN A MODULE
981		1073
982	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
…		…
992	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
993	events is to stay interactive.	1085	events is to stay interactive.
994		1086
995	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
996	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
997	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 >>
998	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).
999		1091
1000	=head1 WHAT TO DO IN THE MAIN PROGRAM	1092	=head1 WHAT TO DO IN THE MAIN PROGRAM
1001		1093
1002	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
1003	dictate which event model to use.	1095	dictate which event model to use.
1004		1096
1005	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
1006	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
1007	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.
1008		1102
1009	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
1010	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
1011	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
1012	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
1013	modules might create watchers when they are loaded, and AnyEvent will	1107	modules might create watchers when they are loaded, and AnyEvent will
1014	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
1015	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.
1016		1110
1017	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
1018	C<AnyEvent::Impl::Perl> module, which gives you similar behaviour	1112	C<AnyEvent::Loop> module, which gives you similar behaviour
1019	everywhere, but letting AnyEvent chose the model is generally better.	1113	everywhere, but letting AnyEvent chose the model is generally better.
1020		1114
1021	=head2 MAINLOOP EMULATION	1115	=head2 MAINLOOP EMULATION
1022		1116
1023	Sometimes (often for short test scripts, or even standalone programs who	1117	Sometimes (often for short test scripts, or even standalone programs who
…		…
1036		1130
1037		1131
1038	=head1 OTHER MODULES	1132	=head1 OTHER MODULES
1039		1133
1040	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
1041	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
1042	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
1043	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 :)
1044		1141
1045	=over 4	1142	=over 4
1046		1143
1047	=item L<AnyEvent::Util>	1144	=item L<AnyEvent::Util>
1048		1145
1049	Contains various utility functions that replace often-used but blocking	1146	Contains various utility functions that replace often-used blocking
1050	functions such as C<inet_aton> by event-/callback-based versions.	1147	functions such as C<inet_aton> with event/callback-based versions.
1051		1148
1052	=item L<AnyEvent::Socket>	1149	=item L<AnyEvent::Socket>
1053		1150
1054	Provides various utility functions for (internet protocol) sockets,	1151	Provides various utility functions for (internet protocol) sockets,
1055	addresses and name resolution. Also functions to create non-blocking tcp	1152	addresses and name resolution. Also functions to create non-blocking tcp
…		…
1057		1154
1058	=item L<AnyEvent::Handle>	1155	=item L<AnyEvent::Handle>
1059		1156
1060	Provide read and write buffers, manages watchers for reads and writes,	1157	Provide read and write buffers, manages watchers for reads and writes,
1061	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
1062	non-blocking SSL/TLS (via L<AnyEvent::TLS>.	1159	non-blocking SSL/TLS (via L<AnyEvent::TLS>).
1063		1160
1064	=item L<AnyEvent::DNS>	1161	=item L<AnyEvent::DNS>
1065		1162
1066	Provides rich asynchronous DNS resolver capabilities.	1163	Provides rich asynchronous DNS resolver capabilities.
1067		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
1068	=item L<AnyEvent::HTTP>	1171	=item L<AnyEvent::AIO>
1069		1172
1070	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
1071	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.
1072		1195
1073	=item L<AnyEvent::HTTPD>	1196	=item L<AnyEvent::HTTPD>
1074		1197
1075	Provides a simple web application server framework.	1198	A simple embedded webserver.
1076		1199
1077	=item L<AnyEvent::FastPing>	1200	=item L<AnyEvent::FastPing>
1078		1201
1079	The fastest ping in the west.	1202	The fastest ping in the west.
1080		1203
1081	=item L<AnyEvent::DBI>
1082
1083	Executes L<DBI> requests asynchronously in a proxy process.
1084
1085	=item L<AnyEvent::AIO>
1086
1087	Truly asynchronous I/O, should be in the toolbox of every event
1088	programmer. AnyEvent::AIO transparently fuses L<IO::AIO> and AnyEvent
1089	together.
1090
1091	=item L<AnyEvent::BDB>
1092
1093	Truly asynchronous Berkeley DB access. AnyEvent::BDB transparently fuses
1094	L<BDB> and AnyEvent together.
1095
1096	=item L<AnyEvent::GPSD>
1097
1098	A non-blocking interface to gpsd, a daemon delivering GPS information.
1099
1100	=item L<AnyEvent::IRC>
1101
1102	AnyEvent based IRC client module family (replacing the older Net::IRC3).
1103
1104	=item L<AnyEvent::XMPP>
1105
1106	AnyEvent based XMPP (Jabber protocol) module family (replacing the older
1107	Net::XMPP2>.
1108
1109	=item L<AnyEvent::IGS>
1110
1111	A non-blocking interface to the Internet Go Server protocol (used by
1112	L<App::IGS>).
1113
1114	=item L<Net::FCP>
1115
1116	AnyEvent-based implementation of the Freenet Client Protocol, birthplace
1117	of AnyEvent.
1118
1119	=item L<Event::ExecFlow>
1120
1121	High level API for event-based execution flow control.
1122
1123	=item L<Coro>	1204	=item L<Coro>
1124		1205
1125	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	};
1126		1219
1127	=back	1220	=back
1128		1221
1129	=cut	1222	=cut
1130		1223
1131	package AnyEvent;	1224	package AnyEvent;
1132		1225
1133	# basically a tuned-down version of common::sense	1226	# basically a tuned-down version of common::sense
1134	sub common_sense {	1227	sub common_sense {
1135	# from common:.sense 1.0	1228	# from common:.sense 3.4
1136	${^WARNING_BITS} = "\xfc\x3f\xf3\x00\x0f\xf3\xcf\xc0\xf3\xfc\x33\x03";	1229	${^WARNING_BITS} ^= ${^WARNING_BITS} ^ "\x3c\x3f\x33\x00\x0f\xf0\x0f\xc0\xf0\xfc\x33\x00";
1137	# use strict vars subs	1230	# use strict vars subs - NO UTF-8, as Util.pm doesn't like this atm. (uts46data.pl)
1138	$^H \|= 0x00000600;	1231	$^H \|= 0x00000600;
1139	}	1232	}
1140		1233
1141	BEGIN { AnyEvent::common_sense }	1234	BEGIN { AnyEvent::common_sense }
1142		1235
1143	use Carp ();	1236	use Carp ();
1144		1237
1145	our $VERSION = '5.21';	1238	our $VERSION = '6.14';
1146	our $MODEL;	1239	our $MODEL;
1147
1148	our $AUTOLOAD;
1149	our @ISA;	1240	our @ISA;
1150
1151	our @REGISTRY;	1241	our @REGISTRY;
1152
1153	our $VERBOSE;	1242	our $VERBOSE;
		1243	our %PROTOCOL; # (ipv4\|ipv6) => (1\|2), higher numbers are preferred
		1244	our $MAX_SIGNAL_LATENCY = $ENV{PERL_ANYEVENT_MAX_SIGNAL_LATENCY} \|\| 10; # executes after the BEGIN block below (tainting!)
1154		1245
1155	BEGIN {	1246	BEGIN {
1156	eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }";	1247	require "AnyEvent/constants.pl";
		1248
1157	eval "sub TAINT(){ " . (${^TAINT}*1) . " }";	1249	eval "sub TAINT (){" . (${^TAINT}*1) . "}";
1158		1250
1159	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}	1251	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}
1160	if ${^TAINT};	1252	if ${^TAINT};
1161		1253
1162	$VERBOSE = $ENV{PERL_ANYEVENT_VERBOSE}*1;	1254	$ENV{"PERL_ANYEVENT_$_"} = $ENV{"AE_$_"}
		1255	for grep s/^AE_// && !exists $ENV{"PERL_ANYEVENT_$_"}, keys %ENV;
1163		1256
1164	}	1257	@ENV{grep /^PERL_ANYEVENT_/, keys %ENV} = ()
		1258	if ${^TAINT};
1165		1259
1166	our $MAX_SIGNAL_LATENCY = 10;	1260	# $ENV{PERL_ANYEVENT_xxx} now valid
1167		1261
1168	our %PROTOCOL; # (ipv4\|ipv6) => (1\|2), higher numbers are preferred	1262	$VERBOSE = length $ENV{PERL_ANYEVENT_VERBOSE} ? $ENV{PERL_ANYEVENT_VERBOSE}*1 : 4;
1169		1263
1170	{
1171	my $idx;	1264	my $idx;
1172	$PROTOCOL{$_} = ++$idx	1265	$PROTOCOL{$_} = ++$idx
1173	for reverse split /\s,\s/,	1266	for reverse split /\s,\s/,
1174	$ENV{PERL_ANYEVENT_PROTOCOLS} \|\| "ipv4,ipv6";	1267	$ENV{PERL_ANYEVENT_PROTOCOLS} \|\| "ipv4,ipv6";
1175	}	1268	}
1176		1269
		1270	our @post_detect;
		1271
		1272	sub post_detect(&) {
		1273	my ($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
1177	my @models = (	1347	our @models = (
1178	[EV:: => AnyEvent::Impl::EV:: , 1],	1348	[EV:: => AnyEvent::Impl::EV::],
1179	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl:: , 1],	1349	[AnyEvent::Loop:: => AnyEvent::Impl::Perl::],
1180	# everything below here will not (normally) be autoprobed	1350	# everything below here will not (normally) be autoprobed
1181	# as the pureperl backend should work everywhere	1351	# as the pure perl backend should work everywhere
1182	# 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
1183	[Event:: => AnyEvent::Impl::Event::, 1],	1354	[Event:: => AnyEvent::Impl::Event::], # slow, stable
1184	[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
1185	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy	1357	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
1186	[Irssi:: => AnyEvent::Impl::Irssi::], # Irssi has a bogus "Event" package
1187	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles	1358	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
1188	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program	1359	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program
1189	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza	1360	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
1190	[Wx:: => AnyEvent::Impl::POE::],	1361	[Wx:: => AnyEvent::Impl::POE::],
1191	[Prima:: => AnyEvent::Impl::POE::],	1362	[Prima:: => AnyEvent::Impl::POE::],
1192	# IO::Async is just too broken - we would need workarounds for its	1363	[IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # a bitch to autodetect
1193	# byzantine signal and broken child handling, among others.	1364	[Cocoa::EventLoop:: => AnyEvent::Impl::Cocoa::],
1194	# IO::Async is rather hard to detect, as it doesn't have any	1365	[FLTK:: => AnyEvent::Impl::FLTK::],
1195	# obvious default class.
1196	[IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program
1197	[IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program
1198	[IO::Async::Notifier:: => AnyEvent::Impl::IOAsync::], # requires special main program
1199	[AnyEvent::Impl::IOAsync:: => AnyEvent::Impl::IOAsync::], # requires special main program
1200	);	1366	);
1201		1367
1202	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, $reset_ae] : undef;
		1385
		1386	_isa_set;
		1387	}
		1388
		1389	# all autoloaded methods reserve the complete glob, not just the method slot.
		1390	# due to bugs in perls method cache implementation.
1203	qw(io timer time now now_update signal child idle condvar one_event DESTROY);	1391	our @methods = qw(io timer time now now_update signal child idle condvar);
1204		1392
1205	our @post_detect;
1206
1207	sub post_detect(&) {	1393	sub detect() {
1208	my ($cb) = @_;	1394	return $MODEL if $MODEL; # some programs keep references to detect
1209		1395
1210	if ($MODEL) {	1396	# IO::Async::Loop::AnyEvent is extremely evil, refuse to work with it
1211	$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 - that module is broken by\n"
		1401	. "design, abuses internals and breaks AnyEvent - will not continue."
		1402	if exists $INC{"IO/Async/Loop/AnyEvent.pm"};
1212		1403
1213	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;
1214	} else {	1423	} else {
1215	push @post_detect, $cb;	1424	AnyEvent::log 4 => "unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@";
1216		1425	}
1217	defined wantarray
1218	? bless \$cb, "AnyEvent::Util::postdetect"
1219	: ()
1220	}	1426	}
1221	}
1222		1427
1223	sub AnyEvent::Util::postdetect::DESTROY {	1428	# check for already loaded models
1224	@post_detect = grep $_ != ${$_[0]}, @post_detect;
1225	}
1226
1227	sub detect() {
1228	unless ($MODEL) {	1429	unless ($MODEL) {
1229	local $SIG{__DIE__};	1430	for (@REGISTRY, @models) {
1230		1431	my ($package, $model) = @$_;
1231	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {	1432	if (${"$package\::VERSION"} > 0) {
1232	my $model = "AnyEvent::Impl::$1";
1233	if (eval "require $model") {	1433	if (eval "require $model") {
		1434	AnyEvent::log 7 => "autodetected model '$model', using it.";
1234	$MODEL = $model;	1435	$MODEL = $model;
1235	warn "AnyEvent: loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.\n" if $VERBOSE >= 2;	1436	last;
1236	} else {	1437	} else {
1237	warn "AnyEvent: unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@" if $VERBOSE;	1438	AnyEvent::log 8 => "detected event loop $package, but cannot load '$model', skipping: $@";
		1439	}
1238	}	1440	}
1239	}	1441	}
1240		1442
1241	# check for already loaded models
1242	unless ($MODEL) {	1443	unless ($MODEL) {
		1444	# try to autoload a model
1243	for (@REGISTRY, @models) {	1445	for (@REGISTRY, @models) {
1244	my ($package, $model) = @$_;	1446	my ($package, $model) = @$_;
		1447	if (
		1448	eval "require $package"
1245	if (${"$package\::VERSION"} > 0) {	1449	and ${"$package\::VERSION"} > 0
1246	if (eval "require $model") {	1450	and eval "require $model"
		1451	) {
		1452	AnyEvent::log 7 => "autoloaded model '$model', using it.";
1247	$MODEL = $model;	1453	$MODEL = $model;
1248	warn "AnyEvent: autodetected model '$model', using it.\n" if $VERBOSE >= 2;
1249	last;	1454	last;
1250	}
1251	}	1455	}
1252	}	1456	}
1253		1457
1254	unless ($MODEL) {
1255	# try to autoload a model
1256	for (@REGISTRY, @models) {
1257	my ($package, $model, $autoload) = @$_;
1258	if (
1259	$autoload
1260	and eval "require $package"
1261	and ${"$package\::VERSION"} > 0
1262	and eval "require $model"
1263	) {
1264	$MODEL = $model;
1265	warn "AnyEvent: autoloaded model '$model', using it.\n" if $VERBOSE >= 2;
1266	last;
1267	}
1268	}
1269
1270	$MODEL	1458	$MODEL
1271	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.\n";	1459	or AnyEvent::log fatal => "AnyEvent: backend autodetection failed - did you properly install AnyEvent?";
1272	}
1273	}	1460	}
1274
1275	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
1276
1277	unshift @ISA, $MODEL;
1278
1279	require AnyEvent::Strict if $ENV{PERL_ANYEVENT_STRICT};
1280
1281	(shift @post_detect)->() while @post_detect;
1282	}	1461	}
1283		1462
		1463	# free memory only needed for probing
		1464	undef @models;
		1465	undef @REGISTRY;
		1466
		1467	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
		1468
		1469	# now nuke some methods that are overridden by the backend.
		1470	# SUPER usage is not allowed in these.
		1471	for (qw(time signal child idle)) {
		1472	undef &{"AnyEvent::Base::$_"}
		1473	if defined &{"$MODEL\::$_"};
		1474	}
		1475
		1476	_isa_set;
		1477
		1478	# we're officially open!
		1479
		1480	if ($ENV{PERL_ANYEVENT_STRICT}) {
		1481	require AnyEvent::Strict;
		1482	}
		1483
		1484	if ($ENV{PERL_ANYEVENT_DEBUG_WRAP}) {
		1485	require AnyEvent::Debug;
		1486	AnyEvent::Debug::wrap ($ENV{PERL_ANYEVENT_DEBUG_WRAP});
		1487	}
		1488
		1489	if (length $ENV{PERL_ANYEVENT_DEBUG_SHELL}) {
		1490	require AnyEvent::Socket;
		1491	require AnyEvent::Debug;
		1492
		1493	my $shell = $ENV{PERL_ANYEVENT_DEBUG_SHELL};
		1494	$shell =~ s/\$\$/$$/g;
		1495
		1496	my ($host, $service) = AnyEvent::Socket::parse_hostport ($shell);
		1497	$AnyEvent::Debug::SHELL = AnyEvent::Debug::shell ($host, $service);
		1498	}
		1499
		1500	# now the anyevent environment is set up as the user told us to, so
		1501	# call the actual user code - post detects
		1502
		1503	(shift @post_detect)->() while @post_detect;
		1504	undef @post_detect;
		1505
		1506	*post_detect = sub(&) {
		1507	shift->();
		1508
		1509	undef
		1510	};
		1511
1284	$MODEL	1512	$MODEL
1285	}	1513	}
1286		1514
1287	sub AUTOLOAD {	1515	for my $name (@methods) {
1288	(my $func = $AUTOLOAD) =~ s/.*://;	1516	*$name = sub {
1289		1517	detect;
1290	$method{$func}	1518	# we use goto because
1291	or Carp::croak "$func: not a valid method for AnyEvent objects";	1519	# a) it makes the thunk more transparent
1292		1520	# b) it allows us to delete the thunk later
1293	detect unless $MODEL;	1521	goto &{ UNIVERSAL::can AnyEvent => "SUPER::$name" }
1294		1522	};
1295	my $class = shift;
1296	$class->$func (@_);
1297	}	1523	}
1298		1524
1299	# utility function to dup a filehandle. this is used by many backends	1525	# utility function to dup a filehandle. this is used by many backends
1300	# to support binding more than one watcher per filehandle (they usually	1526	# to support binding more than one watcher per filehandle (they usually
1301	# allow only one watcher per fd, so we dup it to get a different one).	1527	# allow only one watcher per fd, so we dup it to get a different one).
…		…
1315		1541
1316	=head1 SIMPLIFIED AE API	1542	=head1 SIMPLIFIED AE API
1317		1543
1318	Starting with version 5.0, AnyEvent officially supports a second, much	1544	Starting with version 5.0, AnyEvent officially supports a second, much
1319	simpler, API that is designed to reduce the calling, typing and memory	1545	simpler, API that is designed to reduce the calling, typing and memory
1320	overhead.	1546	overhead by using function call syntax and a fixed number of parameters.
1321		1547
1322	See the L<AE> manpage for details.	1548	See the L<AE> manpage for details.
1323		1549
1324	=cut	1550	=cut
1325		1551
1326	package AE;	1552	package AE;
1327		1553
1328	our $VERSION = $AnyEvent::VERSION;	1554	our $VERSION = $AnyEvent::VERSION;
1329		1555
		1556	sub _reset() {
		1557	eval q{
		1558	# fall back to the main API by default - backends and AnyEvent::Base
		1559	# implementations can overwrite these.
		1560
1330	sub io($$$) {	1561	sub io($$$) {
1331	AnyEvent->io (fh => $_[0], poll => $_[1] ? "w" : "r", cb => $_[2])	1562	AnyEvent->io (fh => $_[0], poll => $_[1] ? "w" : "r", cb => $_[2])
1332	}	1563	}
1333		1564
1334	sub timer($$$) {	1565	sub timer($$$) {
1335	AnyEvent->timer (after => $_[0], interval => $_[1], cb => $_[2])	1566	AnyEvent->timer (after => $_[0], interval => $_[1], cb => $_[2])
1336	}	1567	}
1337		1568
1338	sub signal($$) {	1569	sub signal($$) {
1339	AnyEvent->signal (signal => $_[0], cb => $_[1])	1570	AnyEvent->signal (signal => $_[0], cb => $_[1])
1340	}	1571	}
1341		1572
1342	sub child($$) {	1573	sub child($$) {
1343	AnyEvent->child (pid => $_[0], cb => $_[1])	1574	AnyEvent->child (pid => $_[0], cb => $_[1])
1344	}	1575	}
1345		1576
1346	sub idle($) {	1577	sub idle($) {
1347	AnyEvent->idle (cb => $_[0])	1578	AnyEvent->idle (cb => $_[0]);
1348	}	1579	}
1349		1580
1350	sub cv(;&) {	1581	sub cv(;&) {
1351	AnyEvent->condvar (@_ ? (cb => $_[0]) : ())	1582	AnyEvent->condvar (@_ ? (cb => $_[0]) : ())
1352	}	1583	}
1353		1584
1354	sub now() {	1585	sub now() {
1355	AnyEvent->now	1586	AnyEvent->now
1356	}	1587	}
1357		1588
1358	sub now_update() {	1589	sub now_update() {
1359	AnyEvent->now_update	1590	AnyEvent->now_update
1360	}	1591	}
1361		1592
1362	sub time() {	1593	sub time() {
1363	AnyEvent->time	1594	AnyEvent->time
		1595	}
		1596
		1597	*postpone = \&AnyEvent::postpone;
		1598	*log = \&AnyEvent::log;
		1599	};
		1600	die if $@;
1364	}	1601	}
		1602
		1603	BEGIN { _reset }
1365		1604
1366	package AnyEvent::Base;	1605	package AnyEvent::Base;
1367		1606
1368	# default implementations for many methods	1607	# default implementations for many methods
1369		1608
1370	sub _time() {	1609	sub time {
		1610	eval q{ # poor man's autoloading {}
1371	# probe for availability of Time::HiRes	1611	# probe for availability of Time::HiRes
1372	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {	1612	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {
1373	warn "AnyEvent: using Time::HiRes for sub-second timing accuracy.\n" if $VERBOSE >= 8;	1613	*time = sub { Time::HiRes::time () };
1374	*_time = \&Time::HiRes::time;	1614	*AE::time = \& Time::HiRes::time ;
		1615	*now = \&time;
		1616	AnyEvent::log 8 => "AnyEvent: using Time::HiRes for sub-second timing accuracy.";
1375	# if (eval "use POSIX (); (POSIX::times())...	1617	# if (eval "use POSIX (); (POSIX::times())...
1376	} else {	1618	} else {
		1619	*time = sub { CORE::time };
		1620	*AE::time = sub (){ CORE::time };
		1621	*now = \&time;
1377	warn "AnyEvent: using built-in time(), WARNING, no sub-second resolution!\n" if $VERBOSE;	1622	AnyEvent::log 3 => "using built-in time(), WARNING, no sub-second resolution!";
1378	*_time = sub { time }; # epic fail	1623	}
1379	}	1624	};
		1625	die if $@;
1380		1626
1381	&_time	1627	&time
1382	}	1628	}
1383		1629
1384	sub time { _time }	1630	*now = \&time;
1385	sub now { _time }
1386	sub now_update { }	1631	sub now_update { }
1387		1632
		1633	sub _poll {
		1634	Carp::croak "$AnyEvent::MODEL does not support blocking waits. Caught";
		1635	}
		1636
1388	# default implementation for ->condvar	1637	# default implementation for ->condvar
		1638	# in fact, the default should not be overwritten
1389		1639
1390	sub condvar {	1640	sub condvar {
		1641	eval q{ # poor man's autoloading {}
		1642	*condvar = sub {
1391	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"	1643	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"
		1644	};
		1645
		1646	*AE::cv = sub (;&) {
		1647	bless { @_ ? (_ae_cb => shift) : () }, "AnyEvent::CondVar"
		1648	};
		1649	};
		1650	die if $@;
		1651
		1652	&condvar
1392	}	1653	}
1393		1654
1394	# default implementation for ->signal	1655	# default implementation for ->signal
1395		1656
1396	our $HAVE_ASYNC_INTERRUPT;	1657	our $HAVE_ASYNC_INTERRUPT;
…		…
1405		1666
1406	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);	1667	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);
1407	our (%SIG_ASY, %SIG_ASY_W);	1668	our (%SIG_ASY, %SIG_ASY_W);
1408	our ($SIG_COUNT, $SIG_TW);	1669	our ($SIG_COUNT, $SIG_TW);
1409		1670
1410	sub _signal_exec {
1411	$HAVE_ASYNC_INTERRUPT
1412	? $SIGPIPE_R->drain
1413	: sysread $SIGPIPE_R, (my $dummy), 9;
1414
1415	while (%SIG_EV) {
1416	for (keys %SIG_EV) {
1417	delete $SIG_EV{$_};
1418	$_->() for values %{ $SIG_CB{$_} \|\| {} };
1419	}
1420	}
1421	}
1422
1423	# install a dummy wakeup watcher to reduce signal catching latency	1671	# install a dummy wakeup watcher to reduce signal catching latency
		1672	# used by Impls
1424	sub _sig_add() {	1673	sub _sig_add() {
1425	unless ($SIG_COUNT++) {	1674	unless ($SIG_COUNT++) {
1426	# try to align timer on a full-second boundary, if possible	1675	# try to align timer on a full-second boundary, if possible
1427	my $NOW = AE::now;	1676	my $NOW = AE::now;
1428		1677
…		…
1438	undef $SIG_TW	1687	undef $SIG_TW
1439	unless --$SIG_COUNT;	1688	unless --$SIG_COUNT;
1440	}	1689	}
1441		1690
1442	our $_sig_name_init; $_sig_name_init = sub {	1691	our $_sig_name_init; $_sig_name_init = sub {
1443	eval q{ # poor man's autoloading	1692	eval q{ # poor man's autoloading {}
1444	undef $_sig_name_init;	1693	undef $_sig_name_init;
1445		1694
1446	if (_have_async_interrupt) {	1695	if (_have_async_interrupt) {
1447	*sig2num = \&Async::Interrupt::sig2num;	1696	*sig2num = \&Async::Interrupt::sig2num;
1448	*sig2name = \&Async::Interrupt::sig2name;	1697	*sig2name = \&Async::Interrupt::sig2name;
…		…
1472		1721
1473	sub signal {	1722	sub signal {
1474	eval q{ # poor man's autoloading {}	1723	eval q{ # poor man's autoloading {}
1475	# probe for availability of Async::Interrupt	1724	# probe for availability of Async::Interrupt
1476	if (_have_async_interrupt) {	1725	if (_have_async_interrupt) {
1477	warn "AnyEvent: using Async::Interrupt for race-free signal handling.\n" if $VERBOSE >= 8;	1726	AnyEvent::log 8 => "using Async::Interrupt for race-free signal handling.";
1478		1727
1479	$SIGPIPE_R = new Async::Interrupt::EventPipe;	1728	$SIGPIPE_R = new Async::Interrupt::EventPipe;
1480	$SIG_IO = AE::io $SIGPIPE_R->fileno, 0, \&_signal_exec;	1729	$SIG_IO = AE::io $SIGPIPE_R->fileno, 0, \&_signal_exec;
1481		1730
1482	} else {	1731	} else {
1483	warn "AnyEvent: using emulated perl signal handling with latency timer.\n" if $VERBOSE >= 8;	1732	AnyEvent::log 8 => "using emulated perl signal handling with latency timer.";
1484
1485	require Fcntl;
1486		1733
1487	if (AnyEvent::WIN32) {	1734	if (AnyEvent::WIN32) {
1488	require AnyEvent::Util;	1735	require AnyEvent::Util;
1489		1736
1490	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();	1737	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
1491	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R, 1) if $SIGPIPE_R;	1738	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R, 1) if $SIGPIPE_R;
1492	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W, 1) if $SIGPIPE_W; # just in case	1739	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W, 1) if $SIGPIPE_W; # just in case
1493	} else {	1740	} else {
1494	pipe $SIGPIPE_R, $SIGPIPE_W;	1741	pipe $SIGPIPE_R, $SIGPIPE_W;
1495	fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R;	1742	fcntl $SIGPIPE_R, AnyEvent::F_SETFL, AnyEvent::O_NONBLOCK if $SIGPIPE_R;
1496	fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case	1743	fcntl $SIGPIPE_W, AnyEvent::F_SETFL, AnyEvent::O_NONBLOCK if $SIGPIPE_W; # just in case
1497		1744
1498	# not strictly required, as $^F is normally 2, but let's make sure...	1745	# not strictly required, as $^F is normally 2, but let's make sure...
1499	fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;	1746	fcntl $SIGPIPE_R, AnyEvent::F_SETFD, AnyEvent::FD_CLOEXEC;
1500	fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;	1747	fcntl $SIGPIPE_W, AnyEvent::F_SETFD, AnyEvent::FD_CLOEXEC;
1501	}	1748	}
1502		1749
1503	$SIGPIPE_R	1750	$SIGPIPE_R
1504	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";	1751	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";
1505		1752
1506	$SIG_IO = AE::io $SIGPIPE_R, 0, \&_signal_exec;	1753	$SIG_IO = AE::io $SIGPIPE_R, 0, \&_signal_exec;
1507	}	1754	}
1508		1755
1509	*signal = sub {	1756	*signal = $HAVE_ASYNC_INTERRUPT
		1757	? sub {
1510	my (undef, %arg) = @_;	1758	my (undef, %arg) = @_;
1511		1759
1512	my $signal = uc $arg{signal}
1513	or Carp::croak "required option 'signal' is missing";
1514
1515	if ($HAVE_ASYNC_INTERRUPT) {
1516	# async::interrupt	1760	# async::interrupt
1517
1518	$signal = sig2num $signal;	1761	my $signal = sig2num $arg{signal};
1519	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};	1762	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
1520		1763
1521	$SIG_ASY{$signal} \|\|= new Async::Interrupt	1764	$SIG_ASY{$signal} \|\|= new Async::Interrupt
1522	cb => sub { undef $SIG_EV{$signal} },	1765	cb => sub { undef $SIG_EV{$signal} },
1523	signal => $signal,	1766	signal => $signal,
1524	pipe => [$SIGPIPE_R->filenos],	1767	pipe => [$SIGPIPE_R->filenos],
1525	pipe_autodrain => 0,	1768	pipe_autodrain => 0,
1526	;	1769	;
1527		1770
1528	} else {	1771	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
		1772	}
		1773	: sub {
		1774	my (undef, %arg) = @_;
		1775
1529	# pure perl	1776	# pure perl
1530
1531	# AE::Util has been loaded in signal
1532	$signal = sig2name $signal;	1777	my $signal = sig2name $arg{signal};
1533	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};	1778	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
1534		1779
1535	$SIG{$signal} \|\|= sub {	1780	$SIG{$signal} \|\|= sub {
1536	local $!;	1781	local $!;
1537	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;	1782	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;
1538	undef $SIG_EV{$signal};	1783	undef $SIG_EV{$signal};
1539	};	1784	};
1540		1785
1541	# can't do signal processing without introducing races in pure perl,	1786	# can't do signal processing without introducing races in pure perl,
1542	# so limit the signal latency.	1787	# so limit the signal latency.
1543	_sig_add;	1788	_sig_add;
1544	}
1545		1789
1546	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"	1790	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
		1791	}
1547	};	1792	;
1548		1793
1549	*AnyEvent::Base::signal::DESTROY = sub {	1794	*AnyEvent::Base::signal::DESTROY = sub {
1550	my ($signal, $cb) = @{$_[0]};	1795	my ($signal, $cb) = @{$_[0]};
1551		1796
1552	_sig_del;	1797	_sig_del;
…		…
1559	# print weird messages, or just unconditionally exit	1804	# print weird messages, or just unconditionally exit
1560	# instead of getting the default action.	1805	# instead of getting the default action.
1561	undef $SIG{$signal}	1806	undef $SIG{$signal}
1562	unless keys %{ $SIG_CB{$signal} };	1807	unless keys %{ $SIG_CB{$signal} };
1563	};	1808	};
		1809
		1810	*_signal_exec = sub {
		1811	$HAVE_ASYNC_INTERRUPT
		1812	? $SIGPIPE_R->drain
		1813	: sysread $SIGPIPE_R, (my $dummy), 9;
		1814
		1815	while (%SIG_EV) {
		1816	for (keys %SIG_EV) {
		1817	delete $SIG_EV{$_};
		1818	&$_ for values %{ $SIG_CB{$_} \|\| {} };
		1819	}
		1820	}
		1821	};
1564	};	1822	};
1565	die if $@;	1823	die if $@;
		1824
1566	&signal	1825	&signal
1567	}	1826	}
1568		1827
1569	# default implementation for ->child	1828	# default implementation for ->child
1570		1829
1571	our %PID_CB;	1830	our %PID_CB;
1572	our $CHLD_W;	1831	our $CHLD_W;
1573	our $CHLD_DELAY_W;	1832	our $CHLD_DELAY_W;
1574	our $WNOHANG;
1575		1833
		1834	# used by many Impl's
1576	sub _emit_childstatus($$) {	1835	sub _emit_childstatus($$) {
1577	my (undef, $rpid, $rstatus) = @_;	1836	my (undef, $rpid, $rstatus) = @_;
1578		1837
1579	$_->($rpid, $rstatus)	1838	$_->($rpid, $rstatus)
1580	for values %{ $PID_CB{$rpid} \|\| {} },	1839	for values %{ $PID_CB{$rpid} \|\| {} },
1581	values %{ $PID_CB{0} \|\| {} };	1840	values %{ $PID_CB{0} \|\| {} };
1582	}	1841	}
1583		1842
1584	sub _sigchld {
1585	my $pid;
1586
1587	AnyEvent->_emit_childstatus ($pid, $?)
1588	while ($pid = waitpid -1, $WNOHANG) > 0;
1589	}
1590
1591	sub child {	1843	sub child {
		1844	eval q{ # poor man's autoloading {}
		1845	*_sigchld = sub {
		1846	my $pid;
		1847
		1848	AnyEvent->_emit_childstatus ($pid, $?)
		1849	while ($pid = waitpid -1, WNOHANG) > 0;
		1850	};
		1851
		1852	*child = sub {
1592	my (undef, %arg) = @_;	1853	my (undef, %arg) = @_;
1593		1854
1594	defined (my $pid = $arg{pid} + 0)	1855	my $pid = $arg{pid};
1595	or Carp::croak "required option 'pid' is missing";	1856	my $cb = $arg{cb};
1596		1857
1597	$PID_CB{$pid}{$arg{cb}} = $arg{cb};	1858	$PID_CB{$pid}{$cb+0} = $cb;
1598		1859
1599	# WNOHANG is almost cetrainly 1 everywhere
1600	$WNOHANG \|\|= $^O =~ /^(?:openbsd\|netbsd\|linux\|freebsd\|cygwin\|MSWin32)$/
1601	? 1
1602	: eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } \|\| 1;
1603
1604	unless ($CHLD_W) {	1860	unless ($CHLD_W) {
1605	$CHLD_W = AE::signal CHLD => \&_sigchld;	1861	$CHLD_W = AE::signal CHLD => \&_sigchld;
1606	# child could be a zombie already, so make at least one round	1862	# child could be a zombie already, so make at least one round
1607	&_sigchld;	1863	&_sigchld;
1608	}	1864	}
1609		1865
1610	bless [$pid, $arg{cb}], "AnyEvent::Base::child"	1866	bless [$pid, $cb+0], "AnyEvent::Base::child"
1611	}	1867	};
1612		1868
1613	sub AnyEvent::Base::child::DESTROY {	1869	*AnyEvent::Base::child::DESTROY = sub {
1614	my ($pid, $cb) = @{$_[0]};	1870	my ($pid, $icb) = @{$_[0]};
1615		1871
1616	delete $PID_CB{$pid}{$cb};	1872	delete $PID_CB{$pid}{$icb};
1617	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };	1873	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };
1618		1874
1619	undef $CHLD_W unless keys %PID_CB;	1875	undef $CHLD_W unless keys %PID_CB;
		1876	};
		1877	};
		1878	die if $@;
		1879
		1880	&child
1620	}	1881	}
1621		1882
1622	# idle emulation is done by simply using a timer, regardless	1883	# idle emulation is done by simply using a timer, regardless
1623	# of whether the process is idle or not, and not letting	1884	# of whether the process is idle or not, and not letting
1624	# the callback use more than 50% of the time.	1885	# the callback use more than 50% of the time.
1625	sub idle {	1886	sub idle {
		1887	eval q{ # poor man's autoloading {}
		1888	*idle = sub {
1626	my (undef, %arg) = @_;	1889	my (undef, %arg) = @_;
1627		1890
1628	my ($cb, $w, $rcb) = $arg{cb};	1891	my ($cb, $w, $rcb) = $arg{cb};
1629		1892
1630	$rcb = sub {	1893	$rcb = sub {
1631	if ($cb) {	1894	if ($cb) {
1632	$w = _time;	1895	$w = AE::time;
1633	&$cb;	1896	&$cb;
1634	$w = _time - $w;	1897	$w = AE::time - $w;
1635		1898
1636	# never use more then 50% of the time for the idle watcher,	1899	# never use more then 50% of the time for the idle watcher,
1637	# within some limits	1900	# within some limits
1638	$w = 0.0001 if $w < 0.0001;	1901	$w = 0.0001 if $w < 0.0001;
1639	$w = 5 if $w > 5;	1902	$w = 5 if $w > 5;
1640		1903
1641	$w = AE::timer $w, 0, $rcb;	1904	$w = AE::timer $w, 0, $rcb;
1642	} else {	1905	} else {
1643	# clean up...	1906	# clean up...
1644	undef $w;	1907	undef $w;
1645	undef $rcb;	1908	undef $rcb;
		1909	}
		1910	};
		1911
		1912	$w = AE::timer 0.05, 0, $rcb;
		1913
		1914	bless \\$cb, "AnyEvent::Base::idle"
1646	}	1915	};
		1916
		1917	*AnyEvent::Base::idle::DESTROY = sub {
		1918	undef $${$_[0]};
		1919	};
1647	};	1920	};
		1921	die if $@;
1648		1922
1649	$w = AE::timer 0.05, 0, $rcb;	1923	&idle
1650
1651	bless \\$cb, "AnyEvent::Base::idle"
1652	}
1653
1654	sub AnyEvent::Base::idle::DESTROY {
1655	undef $${$_[0]};
1656	}	1924	}
1657		1925
1658	package AnyEvent::CondVar;	1926	package AnyEvent::CondVar;
1659		1927
1660	our @ISA = AnyEvent::CondVar::Base::;	1928	our @ISA = AnyEvent::CondVar::Base::;
		1929
		1930	# only to be used for subclassing
		1931	sub new {
		1932	my $class = shift;
		1933	bless AnyEvent->condvar (@_), $class
		1934	}
1661		1935
1662	package AnyEvent::CondVar::Base;	1936	package AnyEvent::CondVar::Base;
1663		1937
1664	#use overload	1938	#use overload
1665	# '&{}' => sub { my $self = shift; sub { $self->send (@_) } },	1939	# '&{}' => sub { my $self = shift; sub { $self->send (@_) } },
…		…
1675		1949
1676	sub _send {	1950	sub _send {
1677	# nop	1951	# nop
1678	}	1952	}
1679		1953
		1954	sub _wait {
		1955	AnyEvent->_poll until $_[0]{_ae_sent};
		1956	}
		1957
1680	sub send {	1958	sub send {
1681	my $cv = shift;	1959	my $cv = shift;
1682	$cv->{_ae_sent} = [@_];	1960	$cv->{_ae_sent} = [@_];
1683	(delete $cv->{_ae_cb})->($cv) if $cv->{_ae_cb};	1961	(delete $cv->{_ae_cb})->($cv) if $cv->{_ae_cb};
1684	$cv->_send;	1962	$cv->_send;
…		…
1691		1969
1692	sub ready {	1970	sub ready {
1693	$_[0]{_ae_sent}	1971	$_[0]{_ae_sent}
1694	}	1972	}
1695		1973
1696	sub _wait {
1697	$WAITING
1698	and !$_[0]{_ae_sent}
1699	and Carp::croak "AnyEvent::CondVar: recursive blocking wait detected";
1700
1701	local $WAITING = 1;
1702	AnyEvent->one_event while !$_[0]{_ae_sent};
1703	}
1704
1705	sub recv {	1974	sub recv {
		1975	unless ($_[0]{_ae_sent}) {
		1976	$WAITING
		1977	and Carp::croak "AnyEvent::CondVar: recursive blocking wait attempted";
		1978
		1979	local $WAITING = 1;
1706	$_[0]->_wait;	1980	$_[0]->_wait;
		1981	}
1707		1982
1708	Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak};	1983	$_[0]{_ae_croak}
1709	wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0]	1984	and Carp::croak $_[0]{_ae_croak};
		1985
		1986	wantarray
		1987	? @{ $_[0]{_ae_sent} }
		1988	: $_[0]{_ae_sent}[0]
1710	}	1989	}
1711		1990
1712	sub cb {	1991	sub cb {
1713	my $cv = shift;	1992	my $cv = shift;
1714		1993
…		…
1730	&{ $_[0]{_ae_end_cb} \|\| sub { $_[0]->send } };	2009	&{ $_[0]{_ae_end_cb} \|\| sub { $_[0]->send } };
1731	}	2010	}
1732		2011
1733	# undocumented/compatibility with pre-3.4	2012	# undocumented/compatibility with pre-3.4
1734	*broadcast = \&send;	2013	*broadcast = \&send;
1735	*wait = \&_wait;	2014	*wait = \&recv;
1736		2015
1737	=head1 ERROR AND EXCEPTION HANDLING	2016	=head1 ERROR AND EXCEPTION HANDLING
1738		2017
1739	In general, AnyEvent does not do any error handling - it relies on the	2018	In general, AnyEvent does not do any error handling - it relies on the
1740	caller to do that if required. The L<AnyEvent::Strict> module (see also	2019	caller to do that if required. The L<AnyEvent::Strict> module (see also
…		…
1752	$Event/EV::DIED->() >>, L<Glib> uses C<< install_exception_handler >> and	2031	$Event/EV::DIED->() >>, L<Glib> uses C<< install_exception_handler >> and
1753	so on.	2032	so on.
1754		2033
1755	=head1 ENVIRONMENT VARIABLES	2034	=head1 ENVIRONMENT VARIABLES
1756		2035
1757	The following environment variables are used by this module or its	2036	AnyEvent supports a number of environment variables that tune the
1758	submodules.	2037	runtime behaviour. They are usually evaluated when AnyEvent is
		2038	loaded, initialised, or a submodule that uses them is loaded. Many of
		2039	them also cause AnyEvent to load additional modules - for example,
		2040	C<PERL_ANYEVENT_DEBUG_WRAP> causes the L<AnyEvent::Debug> module to be
		2041	loaded.
1759		2042
1760	Note that AnyEvent will remove I<all> environment variables starting with	2043	All the environment variables documented here start with
1761	C<PERL_ANYEVENT_> from C<%ENV> when it is loaded while taint mode is	2044	C<PERL_ANYEVENT_>, which is what AnyEvent considers its own
1762	enabled.	2045	namespace. Other modules are encouraged (but by no means required) to use
		2046	C<PERL_ANYEVENT_SUBMODULE> if they have registered the AnyEvent::Submodule
		2047	namespace on CPAN, for any submodule. For example, L<AnyEvent::HTTP> could
		2048	be expected to use C<PERL_ANYEVENT_HTTP_PROXY> (it should not access env
		2049	variables starting with C<AE_>, see below).
		2050
		2051	All variables can also be set via the C<AE_> prefix, that is, instead
		2052	of setting C<PERL_ANYEVENT_VERBOSE> you can also set C<AE_VERBOSE>. In
		2053	case there is a clash btween anyevent and another program that uses
		2054	C<AE_something> you can set the corresponding C<PERL_ANYEVENT_something>
		2055	variable to the empty string, as those variables take precedence.
		2056
		2057	When AnyEvent is first loaded, it copies all C<AE_xxx> env variables
		2058	to their C<PERL_ANYEVENT_xxx> counterpart unless that variable already
		2059	exists. If taint mode is on, then AnyEvent will remove I<all> environment
		2060	variables starting with C<PERL_ANYEVENT_> from C<%ENV> (or replace them
		2061	with C<undef> or the empty string, if the corresaponding C<AE_> variable
		2062	is set).
		2063
		2064	The exact algorithm is currently:
		2065
		2066	1. if taint mode enabled, delete all PERL_ANYEVENT_xyz variables from %ENV
		2067	2. copy over AE_xyz to PERL_ANYEVENT_xyz unless the latter alraedy exists
		2068	3. if taint mode enabled, set all PERL_ANYEVENT_xyz variables to undef.
		2069
		2070	This ensures that child processes will not see the C<AE_> variables.
		2071
		2072	The following environment variables are currently known to AnyEvent:
1763		2073
1764	=over 4	2074	=over 4
1765		2075
1766	=item C<PERL_ANYEVENT_VERBOSE>	2076	=item C<PERL_ANYEVENT_VERBOSE>
1767		2077
1768	By default, AnyEvent will be completely silent except in fatal	2078	By default, AnyEvent will only log messages with loglevel C<3>
1769	conditions. You can set this environment variable to make AnyEvent more	2079	(C<critical>) or higher (see L<AnyEvent::Log>). You can set this
		2080	environment variable to a numerical loglevel to make AnyEvent more (or
1770	talkative.	2081	less) talkative.
1771		2082
		2083	If you want to do more than just set the global logging level
		2084	you should have a look at C<PERL_ANYEVENT_LOG>, which allows much more
		2085	complex specifications.
		2086
		2087	When set to C<0> (C<off>), then no messages whatsoever will be logged with
		2088	the default logging settings.
		2089
1772	When set to C<1> or higher, causes AnyEvent to warn about unexpected	2090	When set to C<5> or higher (C<warn>), causes AnyEvent to warn about
1773	conditions, such as not being able to load the event model specified by	2091	unexpected conditions, such as not being able to load the event model
1774	C<PERL_ANYEVENT_MODEL>.	2092	specified by C<PERL_ANYEVENT_MODEL>, or a guard callback throwing an
		2093	exception - this is the minimum recommended level.
1775		2094
1776	When set to C<2> or higher, cause AnyEvent to report to STDERR which event	2095	When set to C<7> or higher (info), cause AnyEvent to report which event model it
1777	model it chooses.	2096	chooses.
1778		2097
1779	When set to C<8> or higher, then AnyEvent will report extra information on	2098	When set to C<8> or higher (debug), then AnyEvent will report extra information on
1780	which optional modules it loads and how it implements certain features.	2099	which optional modules it loads and how it implements certain features.
		2100
		2101	=item C<PERL_ANYEVENT_LOG>
		2102
		2103	Accepts rather complex logging specifications. For example, you could log
		2104	all C<debug> messages of some module to stderr, warnings and above to
		2105	stderr, and errors and above to syslog, with:
		2106
		2107	PERL_ANYEVENT_LOG=Some::Module=debug,+log:filter=warn,+%syslog:%syslog=error,syslog
		2108
		2109	For the rather extensive details, see L<AnyEvent::Log>.
		2110
		2111	This variable is evaluated when AnyEvent (or L<AnyEvent::Log>) is loaded,
		2112	so will take effect even before AnyEvent has initialised itself.
		2113
		2114	Note that specifying this environment variable causes the L<AnyEvent::Log>
		2115	module to be loaded, while C<PERL_ANYEVENT_VERBOSE> does not, so only
		2116	using the latter saves a few hundred kB of memory until the first message
		2117	is being logged.
1781		2118
1782	=item C<PERL_ANYEVENT_STRICT>	2119	=item C<PERL_ANYEVENT_STRICT>
1783		2120
1784	AnyEvent does not do much argument checking by default, as thorough	2121	AnyEvent does not do much argument checking by default, as thorough
1785	argument checking is very costly. Setting this variable to a true value	2122	argument checking is very costly. Setting this variable to a true value
…		…
1787	check the arguments passed to most method calls. If it finds any problems,	2124	check the arguments passed to most method calls. If it finds any problems,
1788	it will croak.	2125	it will croak.
1789		2126
1790	In other words, enables "strict" mode.	2127	In other words, enables "strict" mode.
1791		2128
1792	Unlike C<use strict> (or it's modern cousin, C<< use L<common::sense>	2129	Unlike C<use strict> (or its modern cousin, C<< use L<common::sense>
1793	>>, it is definitely recommended to keep it off in production. Keeping	2130	>>, it is definitely recommended to keep it off in production. Keeping
1794	C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs	2131	C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs
1795	can be very useful, however.	2132	can be very useful, however.
1796		2133
		2134	=item C<PERL_ANYEVENT_DEBUG_SHELL>
		2135
		2136	If this env variable is nonempty, then its contents will be interpreted by
		2137	C<AnyEvent::Socket::parse_hostport> and C<AnyEvent::Debug::shell> (after
		2138	replacing every occurance of C<$$> by the process pid). The shell object
		2139	is saved in C<$AnyEvent::Debug::SHELL>.
		2140
		2141	This happens when the first watcher is created.
		2142
		2143	For example, to bind a debug shell on a unix domain socket in
		2144	F<< /tmp/debug<pid>.sock >>, you could use this:
		2145
		2146	PERL_ANYEVENT_DEBUG_SHELL=/tmp/debug\$\$.sock perlprog
		2147	# connect with e.g.: socat readline /tmp/debug123.sock
		2148
		2149	Or to bind to tcp port 4545 on localhost:
		2150
		2151	PERL_ANYEVENT_DEBUG_SHELL=127.0.0.1:4545 perlprog
		2152	# connect with e.g.: telnet localhost 4545
		2153
		2154	Note that creating sockets in F</tmp> or on localhost is very unsafe on
		2155	multiuser systems.
		2156
		2157	=item C<PERL_ANYEVENT_DEBUG_WRAP>
		2158
		2159	Can be set to C<0>, C<1> or C<2> and enables wrapping of all watchers for
		2160	debugging purposes. See C<AnyEvent::Debug::wrap> for details.
		2161
1797	=item C<PERL_ANYEVENT_MODEL>	2162	=item C<PERL_ANYEVENT_MODEL>
1798		2163
1799	This can be used to specify the event model to be used by AnyEvent, before	2164	This can be used to specify the event model to be used by AnyEvent, before
1800	auto detection and -probing kicks in. It must be a string consisting	2165	auto detection and -probing kicks in.
1801	entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended	2166
		2167	It normally is a string consisting entirely of ASCII letters (e.g. C<EV>
		2168	or C<IOAsync>). The string C<AnyEvent::Impl::> gets prepended and the
1802	and the resulting module name is loaded and if the load was successful,	2169	resulting module name is loaded and - if the load was successful - used as
1803	used as event model. If it fails to load AnyEvent will proceed with	2170	event model backend. If it fails to load then AnyEvent will proceed with
1804	auto detection and -probing.	2171	auto detection and -probing.
1805		2172
1806	This functionality might change in future versions.	2173	If the string ends with C<::> instead (e.g. C<AnyEvent::Impl::EV::>) then
		2174	nothing gets prepended and the module name is used as-is (hint: C<::> at
		2175	the end of a string designates a module name and quotes it appropriately).
1807		2176
1808	For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you	2177	For example, to force the pure perl model (L<AnyEvent::Loop::Perl>) you
1809	could start your program like this:	2178	could start your program like this:
1810		2179
1811	PERL_ANYEVENT_MODEL=Perl perl ...	2180	PERL_ANYEVENT_MODEL=Perl perl ...
1812		2181
1813	=item C<PERL_ANYEVENT_PROTOCOLS>	2182	=item C<PERL_ANYEVENT_PROTOCOLS>
…		…
1829	but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4>	2198	but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4>
1830	- only support IPv4, never try to resolve or contact IPv6	2199	- only support IPv4, never try to resolve or contact IPv6
1831	addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or	2200	addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or
1832	IPv6, but prefer IPv6 over IPv4.	2201	IPv6, but prefer IPv6 over IPv4.
1833		2202
		2203	=item C<PERL_ANYEVENT_HOSTS>
		2204
		2205	This variable, if specified, overrides the F</etc/hosts> file used by
		2206	L<AnyEvent::Socket>C<::resolve_sockaddr>, i.e. hosts aliases will be read
		2207	from that file instead.
		2208
1834	=item C<PERL_ANYEVENT_EDNS0>	2209	=item C<PERL_ANYEVENT_EDNS0>
1835		2210
1836	Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension	2211	Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension for
1837	for DNS. This extension is generally useful to reduce DNS traffic, but	2212	DNS. This extension is generally useful to reduce DNS traffic, especially
1838	some (broken) firewalls drop such DNS packets, which is why it is off by	2213	when DNSSEC is involved, but some (broken) firewalls drop such DNS
1839	default.	2214	packets, which is why it is off by default.
1840		2215
1841	Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce	2216	Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce
1842	EDNS0 in its DNS requests.	2217	EDNS0 in its DNS requests.
1843		2218
1844	=item C<PERL_ANYEVENT_MAX_FORKS>	2219	=item C<PERL_ANYEVENT_MAX_FORKS>
…		…
1850		2225
1851	The default value for the C<max_outstanding> parameter for the default DNS	2226	The default value for the C<max_outstanding> parameter for the default DNS
1852	resolver - this is the maximum number of parallel DNS requests that are	2227	resolver - this is the maximum number of parallel DNS requests that are
1853	sent to the DNS server.	2228	sent to the DNS server.
1854		2229
		2230	=item C<PERL_ANYEVENT_MAX_SIGNAL_LATENCY>
		2231
		2232	Perl has inherently racy signal handling (you can basically choose between
		2233	losing signals and memory corruption) - pure perl event loops (including
		2234	C<AnyEvent::Loop>, when C<Async::Interrupt> isn't available) therefore
		2235	have to poll regularly to avoid losing signals.
		2236
		2237	Some event loops are racy, but don't poll regularly, and some event loops
		2238	are written in C but are still racy. For those event loops, AnyEvent
		2239	installs a timer that regularly wakes up the event loop.
		2240
		2241	By default, the interval for this timer is C<10> seconds, but you can
		2242	override this delay with this environment variable (or by setting
		2243	the C<$AnyEvent::MAX_SIGNAL_LATENCY> variable before creating signal
		2244	watchers).
		2245
		2246	Lower values increase CPU (and energy) usage, higher values can introduce
		2247	long delays when reaping children or waiting for signals.
		2248
		2249	The L<AnyEvent::Async> module, if available, will be used to avoid this
		2250	polling (with most event loops).
		2251
1855	=item C<PERL_ANYEVENT_RESOLV_CONF>	2252	=item C<PERL_ANYEVENT_RESOLV_CONF>
1856		2253
1857	The file to use instead of F</etc/resolv.conf> (or OS-specific	2254	The absolute path to a F<resolv.conf>-style file to use instead of
1858	configuration) in the default resolver. When set to the empty string, no	2255	F</etc/resolv.conf> (or the OS-specific configuration) in the default
1859	default config will be used.	2256	resolver, or the empty string to select the default configuration.
1860		2257
1861	=item C<PERL_ANYEVENT_CA_FILE>, C<PERL_ANYEVENT_CA_PATH>.	2258	=item C<PERL_ANYEVENT_CA_FILE>, C<PERL_ANYEVENT_CA_PATH>.
1862		2259
1863	When neither C<ca_file> nor C<ca_path> was specified during	2260	When neither C<ca_file> nor C<ca_path> was specified during
1864	L<AnyEvent::TLS> context creation, and either of these environment	2261	L<AnyEvent::TLS> context creation, and either of these environment
1865	variables exist, they will be used to specify CA certificate locations	2262	variables are nonempty, they will be used to specify CA certificate
1866	instead of a system-dependent default.	2263	locations instead of a system-dependent default.
1867		2264
1868	=item C<PERL_ANYEVENT_AVOID_GUARD> and C<PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT>	2265	=item C<PERL_ANYEVENT_AVOID_GUARD> and C<PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT>
1869		2266
1870	When these are set to C<1>, then the respective modules are not	2267	When these are set to C<1>, then the respective modules are not
1871	loaded. Mostly good for testing AnyEvent itself.	2268	loaded. Mostly good for testing AnyEvent itself.
…		…
2019		2416
2020	The actual code goes further and collects all errors (C<die>s, exceptions)	2417	The actual code goes further and collects all errors (C<die>s, exceptions)
2021	that occurred during request processing. The C<result> method detects	2418	that occurred during request processing. The C<result> method detects
2022	whether an exception as thrown (it is stored inside the $txn object)	2419	whether an exception as thrown (it is stored inside the $txn object)
2023	and just throws the exception, which means connection errors and other	2420	and just throws the exception, which means connection errors and other
2024	problems get reported tot he code that tries to use the result, not in a	2421	problems get reported to the code that tries to use the result, not in a
2025	random callback.	2422	random callback.
2026		2423
2027	All of this enables the following usage styles:	2424	All of this enables the following usage styles:
2028		2425
2029	1. Blocking:	2426	1. Blocking:
…		…
2203	(even when used without AnyEvent), but most event loops have acceptable	2600	(even when used without AnyEvent), but most event loops have acceptable
2204	performance with or without AnyEvent.	2601	performance with or without AnyEvent.
2205		2602
2206	=item * The overhead AnyEvent adds is usually much smaller than the overhead of	2603	=item * The overhead AnyEvent adds is usually much smaller than the overhead of
2207	the actual event loop, only with extremely fast event loops such as EV	2604	the actual event loop, only with extremely fast event loops such as EV
2208	adds AnyEvent significant overhead.	2605	does AnyEvent add significant overhead.
2209		2606
2210	=item * You should avoid POE like the plague if you want performance or	2607	=item * You should avoid POE like the plague if you want performance or
2211	reasonable memory usage.	2608	reasonable memory usage.
2212		2609
2213	=back	2610	=back
…		…
2443	unless defined $SIG{PIPE};	2840	unless defined $SIG{PIPE};
2444		2841
2445	=head1 RECOMMENDED/OPTIONAL MODULES	2842	=head1 RECOMMENDED/OPTIONAL MODULES
2446		2843
2447	One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and	2844	One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and
2448	it's built-in modules) are required to use it.	2845	its built-in modules) are required to use it.
2449		2846
2450	That does not mean that AnyEvent won't take advantage of some additional	2847	That does not mean that AnyEvent won't take advantage of some additional
2451	modules if they are installed.	2848	modules if they are installed.
2452		2849
2453	This section epxlains which additional modules will be used, and how they	2850	This section explains which additional modules will be used, and how they
2454	affect AnyEvent's operation.	2851	affect AnyEvent's operation.
2455		2852
2456	=over 4	2853	=over 4
2457		2854
2458	=item L<Async::Interrupt>	2855	=item L<Async::Interrupt>
…		…
2464	catch the signals) with some delay (default is 10 seconds, look for	2861	catch the signals) with some delay (default is 10 seconds, look for
2465	C<$AnyEvent::MAX_SIGNAL_LATENCY>).	2862	C<$AnyEvent::MAX_SIGNAL_LATENCY>).
2466		2863
2467	If this module is available, then it will be used to implement signal	2864	If this module is available, then it will be used to implement signal
2468	catching, which means that signals will not be delayed, and the event loop	2865	catching, which means that signals will not be delayed, and the event loop
2469	will not be interrupted regularly, which is more efficient (And good for	2866	will not be interrupted regularly, which is more efficient (and good for
2470	battery life on laptops).	2867	battery life on laptops).
2471		2868
2472	This affects not just the pure-perl event loop, but also other event loops	2869	This affects not just the pure-perl event loop, but also other event loops
2473	that have no signal handling on their own (e.g. Glib, Tk, Qt).	2870	that have no signal handling on their own (e.g. Glib, Tk, Qt).
2474		2871
…		…
2486	automatic timer adjustments even when no monotonic clock is available,	2883	automatic timer adjustments even when no monotonic clock is available,
2487	can take avdantage of advanced kernel interfaces such as C<epoll> and	2884	can take avdantage of advanced kernel interfaces such as C<epoll> and
2488	C<kqueue>, and is the fastest backend I<by far>. You can even embed	2885	C<kqueue>, and is the fastest backend I<by far>. You can even embed
2489	L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>).	2886	L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>).
2490		2887
		2888	If you only use backends that rely on another event loop (e.g. C<Tk>),
		2889	then this module will do nothing for you.
		2890
2491	=item L<Guard>	2891	=item L<Guard>
2492		2892
2493	The guard module, when used, will be used to implement	2893	The guard module, when used, will be used to implement
2494	C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a	2894	C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a
2495	lot less memory), but otherwise doesn't affect guard operation much. It is	2895	lot less memory), but otherwise doesn't affect guard operation much. It is
2496	purely used for performance.	2896	purely used for performance.
2497		2897
2498	=item L<JSON> and L<JSON::XS>	2898	=item L<JSON> and L<JSON::XS>
2499		2899
2500	One of these modules is required when you want to read or write JSON data	2900	One of these modules is required when you want to read or write JSON data
2501	via L<AnyEvent::Handle>. It is also written in pure-perl, but can take	2901	via L<AnyEvent::Handle>. L<JSON> is also written in pure-perl, but can take
2502	advantage of the ultra-high-speed L<JSON::XS> module when it is installed.	2902	advantage of the ultra-high-speed L<JSON::XS> module when it is installed.
2503
2504	In fact, L<AnyEvent::Handle> will use L<JSON::XS> by default if it is
2505	installed.
2506		2903
2507	=item L<Net::SSLeay>	2904	=item L<Net::SSLeay>
2508		2905
2509	Implementing TLS/SSL in Perl is certainly interesting, but not very	2906	Implementing TLS/SSL in Perl is certainly interesting, but not very
2510	worthwhile: If this module is installed, then L<AnyEvent::Handle> (with	2907	worthwhile: If this module is installed, then L<AnyEvent::Handle> (with
2511	the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL.	2908	the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL.
2512		2909
2513	=item L<Time::HiRes>	2910	=item L<Time::HiRes>
2514		2911
2515	This module is part of perl since release 5.008. It will be used when the	2912	This module is part of perl since release 5.008. It will be used when the
2516	chosen event library does not come with a timing source on it's own. The	2913	chosen event library does not come with a timing source of its own. The
2517	pure-perl event loop (L<AnyEvent::Impl::Perl>) will additionally use it to	2914	pure-perl event loop (L<AnyEvent::Loop>) will additionally load it to
2518	try to use a monotonic clock for timing stability.	2915	try to use a monotonic clock for timing stability.
2519		2916
2520	=back	2917	=back
2521		2918
2522		2919
2523	=head1 FORK	2920	=head1 FORK
2524		2921
2525	Most event libraries are not fork-safe. The ones who are usually are	2922	Most event libraries are not fork-safe. The ones who are usually are
2526	because they rely on inefficient but fork-safe C<select> or C<poll>	2923	because they rely on inefficient but fork-safe C<select> or C<poll> calls
2527	calls. Only L<EV> is fully fork-aware.	2924	- higher performance APIs such as BSD's kqueue or the dreaded Linux epoll
		2925	are usually badly thought-out hacks that are incompatible with fork in
		2926	one way or another. Only L<EV> is fully fork-aware and ensures that you
		2927	continue event-processing in both parent and child (or both, if you know
		2928	what you are doing).
		2929
		2930	This means that, in general, you cannot fork and do event processing in
		2931	the child if the event library was initialised before the fork (which
		2932	usually happens when the first AnyEvent watcher is created, or the library
		2933	is loaded).
2528		2934
2529	If you have to fork, you must either do so I<before> creating your first	2935	If you have to fork, you must either do so I<before> creating your first
2530	watcher OR you must not use AnyEvent at all in the child OR you must do	2936	watcher OR you must not use AnyEvent at all in the child OR you must do
2531	something completely out of the scope of AnyEvent.	2937	something completely out of the scope of AnyEvent.
		2938
		2939	The problem of doing event processing in the parent I<and> the child
		2940	is much more complicated: even for backends that I<are> fork-aware or
		2941	fork-safe, their behaviour is not usually what you want: fork clones all
		2942	watchers, that means all timers, I/O watchers etc. are active in both
		2943	parent and child, which is almost never what you want. USing C<exec>
		2944	to start worker children from some kind of manage rprocess is usually
		2945	preferred, because it is much easier and cleaner, at the expense of having
		2946	to have another binary.
2532		2947
2533		2948
2534	=head1 SECURITY CONSIDERATIONS	2949	=head1 SECURITY CONSIDERATIONS
2535		2950
2536	AnyEvent can be forced to load any event model via	2951	AnyEvent can be forced to load any event model via
…		…
2566	pronounced).	2981	pronounced).
2567		2982
2568		2983
2569	=head1 SEE ALSO	2984	=head1 SEE ALSO
2570		2985
2571	Utility functions: L<AnyEvent::Util>.	2986	Tutorial/Introduction: L<AnyEvent::Intro>.
2572		2987
2573	Event modules: L<EV>, L<EV::Glib>, L<Glib::EV>, L<Event>, L<Glib::Event>,	2988	FAQ: L<AnyEvent::FAQ>.
2574	L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.	2989
		2990	Utility functions: L<AnyEvent::Util> (misc. grab-bag), L<AnyEvent::Log>
		2991	(simply logging).
		2992
		2993	Development/Debugging: L<AnyEvent::Strict> (stricter checking),
		2994	L<AnyEvent::Debug> (interactive shell, watcher tracing).
		2995
		2996	Supported event modules: L<AnyEvent::Loop>, L<EV>, L<EV::Glib>,
		2997	L<Glib::EV>, L<Event>, L<Glib::Event>, L<Glib>, L<Tk>, L<Event::Lib>,
		2998	L<Qt>, L<POE>, L<FLTK>.
2575		2999
2576	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,	3000	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,
2577	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,	3001	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,
2578	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,	3002	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,
2579	L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>, L<Anyevent::Impl::Irssi>.	3003	L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>, L<Anyevent::Impl::Irssi>,
		3004	L<AnyEvent::Impl::FLTK>.
2580		3005
2581	Non-blocking file handles, sockets, TCP clients and	3006	Non-blocking handles, pipes, stream sockets, TCP clients and
2582	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.	3007	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.
2583		3008
2584	Asynchronous DNS: L<AnyEvent::DNS>.	3009	Asynchronous DNS: L<AnyEvent::DNS>.
2585		3010
2586	Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>,	3011	Thread support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>.
2587	L<Coro::Event>,
2588		3012
2589	Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::XMPP>,	3013	Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::IRC>,
2590	L<AnyEvent::HTTP>.	3014	L<AnyEvent::HTTP>.
2591		3015
2592		3016
2593	=head1 AUTHOR	3017	=head1 AUTHOR
2594		3018

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Comparing AnyEvent/lib/AnyEvent.pm (file contents): Revision 1.299 by root, Tue Dec 1 17:53:48 2009 UTC vs. Revision 1.396 by root, Sat Mar 10 17:36:24 2012 UTC

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Comparing AnyEvent/lib/AnyEvent.pm (file contents):
Revision 1.299 by root, Tue Dec 1 17:53:48 2009 UTC vs.
Revision 1.396 by root, Sat Mar 10 17:36:24 2012 UTC