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Revision 1.295 by root, Wed Oct 28 02:42:06 2009 UTC vs.
Revision 1.409 by root, Thu Dec 6 12:10:09 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	});
…		…
210		214
211	The I/O watcher might use the underlying file descriptor or a copy of it.	215	The I/O watcher might use the underlying file descriptor or a copy of it.
212	You must not close a file handle as long as any watcher is active on the	216	You must not close a file handle as long as any watcher is active on the
213	underlying file descriptor.	217	underlying file descriptor.
214		218
215	Some event loops issue spurious readyness notifications, so you should	219	Some event loops issue spurious readiness notifications, so you should
216	always use non-blocking calls when reading/writing from/to your file	220	always use non-blocking calls when reading/writing from/to your file
217	handles.	221	handles.
218		222
219	Example: wait for readability of STDIN, then read a line and disable the	223	Example: wait for readability of STDIN, then read a line and disable the
220	watcher.	224	watcher.
…		…
244		248
245	Although the callback might get passed parameters, their value and	249	Although the callback might get passed parameters, their value and
246	presence is undefined and you cannot rely on them. Portable AnyEvent	250	presence is undefined and you cannot rely on them. Portable AnyEvent
247	callbacks cannot use arguments passed to time watcher callbacks.	251	callbacks cannot use arguments passed to time watcher callbacks.
248		252
249	The callback will normally be invoked once only. If you specify another	253	The callback will normally be invoked only once. If you specify another
250	parameter, C<interval>, as a strictly positive number (> 0), then the	254	parameter, C<interval>, as a strictly positive number (> 0), then the
251	callback will be invoked regularly at that interval (in fractional	255	callback will be invoked regularly at that interval (in fractional
252	seconds) after the first invocation. If C<interval> is specified with a	256	seconds) after the first invocation. If C<interval> is specified with a
253	false value, then it is treated as if it were missing.	257	false value, then it is treated as if it were not specified at all.
254		258
255	The callback will be rescheduled before invoking the callback, but no	259	The callback will be rescheduled before invoking the callback, but no
256	attempt is done to avoid timer drift in most backends, so the interval is	260	attempt is made to avoid timer drift in most backends, so the interval is
257	only approximate.	261	only approximate.
258		262
259	Example: fire an event after 7.7 seconds.	263	Example: fire an event after 7.7 seconds.
260		264
261	my $w = AnyEvent->timer (after => 7.7, cb => sub {	265	my $w = AnyEvent->timer (after => 7.7, cb => sub {
…		…
279		283
280	While most event loops expect timers to specified in a relative way, they	284	While most event loops expect timers to specified in a relative way, they
281	use absolute time internally. This makes a difference when your clock	285	use absolute time internally. This makes a difference when your clock
282	"jumps", for example, when ntp decides to set your clock backwards from	286	"jumps", for example, when ntp decides to set your clock backwards from
283	the wrong date of 2014-01-01 to 2008-01-01, a watcher that is supposed to	287	the wrong date of 2014-01-01 to 2008-01-01, a watcher that is supposed to
284	fire "after" a second might actually take six years to finally fire.	288	fire "after a second" might actually take six years to finally fire.
285		289
286	AnyEvent cannot compensate for this. The only event loop that is conscious	290	AnyEvent cannot compensate for this. The only event loop that is conscious
287	about these issues is L<EV>, which offers both relative (ev_timer, based	291	of these issues is L<EV>, which offers both relative (ev_timer, based
288	on true relative time) and absolute (ev_periodic, based on wallclock time)	292	on true relative time) and absolute (ev_periodic, based on wallclock time)
289	timers.	293	timers.
290		294
291	AnyEvent always prefers relative timers, if available, matching the	295	AnyEvent always prefers relative timers, if available, matching the
292	AnyEvent API.	296	AnyEvent API.
…		…
314	I<In almost all cases (in all cases if you don't care), this is the	318	I<In almost all cases (in all cases if you don't care), this is the
315	function to call when you want to know the current time.>	319	function to call when you want to know the current time.>
316		320
317	This function is also often faster then C<< AnyEvent->time >>, and	321	This function is also often faster then C<< AnyEvent->time >>, and
318	thus the preferred method if you want some timestamp (for example,	322	thus the preferred method if you want some timestamp (for example,
319	L<AnyEvent::Handle> uses this to update it's activity timeouts).	323	L<AnyEvent::Handle> uses this to update its activity timeouts).
320		324
321	The rest of this section is only of relevance if you try to be very exact	325	The rest of this section is only of relevance if you try to be very exact
322	with your timing, you can skip it without bad conscience.	326	with your timing; you can skip it without a bad conscience.
323		327
324	For a practical example of when these times differ, consider L<Event::Lib>	328	For a practical example of when these times differ, consider L<Event::Lib>
325	and L<EV> and the following set-up:	329	and L<EV> and the following set-up:
326		330
327	The event loop is running and has just invoked one of your callback at	331	The event loop is running and has just invoked one of your callbacks at
328	time=500 (assume no other callbacks delay processing). In your callback,	332	time=500 (assume no other callbacks delay processing). In your callback,
329	you wait a second by executing C<sleep 1> (blocking the process for a	333	you wait a second by executing C<sleep 1> (blocking the process for a
330	second) and then (at time=501) you create a relative timer that fires	334	second) and then (at time=501) you create a relative timer that fires
331	after three seconds.	335	after three seconds.
332		336
…		…
352	difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into	356	difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into
353	account.	357	account.
354		358
355	=item AnyEvent->now_update	359	=item AnyEvent->now_update
356		360
357	Some event loops (such as L<EV> or L<AnyEvent::Impl::Perl>) cache	361	Some event loops (such as L<EV> or L<AnyEvent::Loop>) cache the current
358	the current time for each loop iteration (see the discussion of L<<	362	time for each loop iteration (see the discussion of L<< AnyEvent->now >>,
359	AnyEvent->now >>, above).	363	above).
360		364
361	When a callback runs for a long time (or when the process sleeps), then	365	When a callback runs for a long time (or when the process sleeps), then
362	this "current" time will differ substantially from the real time, which	366	this "current" time will differ substantially from the real time, which
363	might affect timers and time-outs.	367	might affect timers and time-outs.
364		368
365	When this is the case, you can call this method, which will update the	369	When this is the case, you can call this method, which will update the
366	event loop's idea of "current time".	370	event loop's idea of "current time".
		371
		372	A typical example would be a script in a web server (e.g. C<mod_perl>) -
		373	when mod_perl executes the script, then the event loop will have the wrong
		374	idea about the "current time" (being potentially far in the past, when the
		375	script ran the last time). In that case you should arrange a call to C<<
		376	AnyEvent->now_update >> each time the web server process wakes up again
		377	(e.g. at the start of your script, or in a handler).
367		378
368	Note that updating the time I<might> cause some events to be handled.	379	Note that updating the time I<might> cause some events to be handled.
369		380
370	=back	381	=back
371		382
…		…
396		407
397	Example: exit on SIGINT	408	Example: exit on SIGINT
398		409
399	my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });	410	my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });
400		411
		412	=head3 Restart Behaviour
		413
		414	While restart behaviour is up to the event loop implementation, most will
		415	not restart syscalls (that includes L<Async::Interrupt> and AnyEvent's
		416	pure perl implementation).
		417
		418	=head3 Safe/Unsafe Signals
		419
		420	Perl signals can be either "safe" (synchronous to opcode handling)
		421	or "unsafe" (asynchronous) - the former might delay signal delivery
		422	indefinitely, the latter might corrupt your memory.
		423
		424	AnyEvent signal handlers are, in addition, synchronous to the event loop,
		425	i.e. they will not interrupt your running perl program but will only be
		426	called as part of the normal event handling (just like timer, I/O etc.
		427	callbacks, too).
		428
401	=head3 Signal Races, Delays and Workarounds	429	=head3 Signal Races, Delays and Workarounds
402		430
403	Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support attaching	431	Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support
404	callbacks to signals in a generic way, which is a pity, as you cannot	432	attaching callbacks to signals in a generic way, which is a pity,
405	do race-free signal handling in perl, requiring C libraries for	433	as you cannot do race-free signal handling in perl, requiring
406	this. AnyEvent will try to do it's best, which means in some cases,	434	C libraries for this. AnyEvent will try to do its best, which
407	signals will be delayed. The maximum time a signal might be delayed is	435	means in some cases, signals will be delayed. The maximum time
408	specified in C<$AnyEvent::MAX_SIGNAL_LATENCY> (default: 10 seconds). This	436	a signal might be delayed is 10 seconds by default, but can
409	variable can be changed only before the first signal watcher is created,	437	be overriden via C<$ENV{PERL_ANYEVENT_MAX_SIGNAL_LATENCY}> or
410	and should be left alone otherwise. This variable determines how often	438	C<$AnyEvent::MAX_SIGNAL_LATENCY> - see the L<ENVIRONMENT VARIABLES>
411	AnyEvent polls for signals (in case a wake-up was missed). Higher values	439	section for details.
412	will cause fewer spurious wake-ups, which is better for power and CPU
413	saving.
414		440
415	All these problems can be avoided by installing the optional	441	All these problems can be avoided by installing the optional
416	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
417	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>
418	(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
419	one-second latency). For those, you just have to suffer the delays.	445	delays.
420		446
421	=head2 CHILD PROCESS WATCHERS	447	=head2 CHILD PROCESS WATCHERS
422		448
423	$w = AnyEvent->child (pid => <process id>, cb => <callback>);	449	$w = AnyEvent->child (pid => <process id>, cb => <callback>);
424		450
425	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.
426		452
427	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,
428	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
429	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
430	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
431	(stopped/continued).	457	(stopped/continued).
432		458
…		…
454	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
455	watcher before you C<fork> the child (alternatively, you can call	481	watcher before you C<fork> the child (alternatively, you can call
456	C<AnyEvent::detect>).	482	C<AnyEvent::detect>).
457		483
458	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
459	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
460	mentioned in the description of signal watchers apply.	486	problems mentioned in the description of signal watchers apply.
461		487
462	Example: fork a process and wait for it	488	Example: fork a process and wait for it
463		489
464	my $done = AnyEvent->condvar;	490	my $done = AnyEvent->condvar;
465		491
…		…
479		505
480	=head2 IDLE WATCHERS	506	=head2 IDLE WATCHERS
481		507
482	$w = AnyEvent->idle (cb => <callback>);	508	$w = AnyEvent->idle (cb => <callback>);
483		509
484	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,
485	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.
486	"nothing better to do" is usually defined to be "no other events need
487	attention by the event loop".
488		512
489	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
490	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
491	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.
492		521
493	Most event loops unfortunately do not really support idle watchers (only	522	Unfortunately, most event loops do not really support idle watchers (only
494	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
495	will simply call the callback "from time to time".	524	will simply call the callback "from time to time".
496		525
497	Example: read lines from STDIN, but only process them when the	526	Example: read lines from STDIN, but only process them when the
498	program is otherwise idle:	527	program is otherwise idle:
…		…
526	will actively watch for new events and call your callbacks.	555	will actively watch for new events and call your callbacks.
527		556
528	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
529	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).
530		559
531	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
532	because they represent a condition that must become true.	561	they represent a condition that must become true.
533		562
534	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.
535		564
536	Condition variables can be created by calling the C<< AnyEvent->condvar	565	Condition variables can be created by calling the C<< AnyEvent->condvar
537	>> method, usually without arguments. The only argument pair allowed is	566	>> method, usually without arguments. The only argument pair allowed is
…		…
542	After creation, the condition variable is "false" until it becomes "true"	571	After creation, the condition variable is "false" until it becomes "true"
543	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
544	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<<
545	->send >> method).	574	->send >> method).
546		575
547	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
548	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:
549	in time where multiple outstanding events have been processed. And yet	578
550	another way to call them is transactions - each condition variable can be	579	=over 4
551	used to represent a transaction, which finishes at some point and delivers	580
552	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
553	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
554		599
555	Condition variables are very useful to signal that something has finished,	600	Condition variables are very useful to signal that something has finished,
556	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,
557	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
558	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
…		…
571		616
572	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
573	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
574	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
575	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
576	it's C<new> method in your own C<new> method.	621	its C<new> method in your own C<new> method.
577		622
578	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
579	eventually calls C<< -> send >>, and the "consumer side", which waits	624	eventually calls C<< -> send >>, and the "consumer side", which waits
580	for the send to occur.	625	for the send to occur.
581		626
582	Example: wait for a timer.	627	Example: wait for a timer.
583		628
584	# wait till the result is ready	629	# condition: "wait till the timer is fired"
585	my $result_ready = AnyEvent->condvar;	630	my $timer_fired = AnyEvent->condvar;
586		631
587	# do something such as adding a timer	632	# create the timer - we could wait for, say
588	# or socket watcher the calls $result_ready->send	633	# a handle becomign ready, or even an
589	# when the "result" is ready.	634	# AnyEvent::HTTP request to finish, but
590	# in this case, we simply use a timer:	635	# in this case, we simply use a timer:
591	my $w = AnyEvent->timer (	636	my $w = AnyEvent->timer (
592	after => 1,	637	after => 1,
593	cb => sub { $result_ready->send },	638	cb => sub { $timer_fired->send },
594	);	639	);
595		640
596	# this "blocks" (while handling events) till the callback	641	# this "blocks" (while handling events) till the callback
597	# calls ->send	642	# calls ->send
598	$result_ready->recv;	643	$timer_fired->recv;
599		644
600	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
601	variables are also callable directly.	646	variables are also callable directly.
602		647
603	my $done = AnyEvent->condvar;	648	my $done = AnyEvent->condvar;
…		…
646	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
647	C<send>.	692	C<send>.
648		693
649	=item $cv->croak ($error)	694	=item $cv->croak ($error)
650		695
651	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
652	C<Carp::croak> with the given error message/object/scalar.	697	C<Carp::croak> with the given error message/object/scalar.
653		698
654	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
655	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
656	delays the error detetcion, but has the overwhelmign advantage that it	701	delays the error detection, but has the overwhelming advantage that it
657	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
658	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
659	the problem.	704	the problem.
660		705
661	=item $cv->begin ([group callback])	706	=item $cv->begin ([group callback])
662		707
663	=item $cv->end	708	=item $cv->end
…		…
701	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
702	sending.	747	sending.
703		748
704	The ping example mentioned above is slightly more complicated, as the	749	The ping example mentioned above is slightly more complicated, as the
705	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
706	begung can potentially be zero:	751	begun can potentially be zero:
707		752
708	my $cv = AnyEvent->condvar;	753	my $cv = AnyEvent->condvar;
709		754
710	my %result;	755	my %result;
711	$cv->begin (sub { shift->send (\%result) });	756	$cv->begin (sub { shift->send (\%result) });
…		…
718	};	763	};
719	}	764	}
720		765
721	$cv->end;	766	$cv->end;
722		767
		768	...
		769
		770	my $results = $cv->recv;
		771
723	This code fragment supposedly pings a number of hosts and calls	772	This code fragment supposedly pings a number of hosts and calls
724	C<send> after results for all then have have been gathered - in any	773	C<send> after results for all then have have been gathered - in any
725	order. To achieve this, the code issues a call to C<begin> when it starts	774	order. To achieve this, the code issues a call to C<begin> when it starts
726	each ping request and calls C<end> when it has received some result for	775	each ping request and calls C<end> when it has received some result for
727	it. Since C<begin> and C<end> only maintain a counter, the order in which	776	it. Since C<begin> and C<end> only maintain a counter, the order in which
…		…
732	to be called once the counter reaches C<0>, and second, it ensures that	781	to be called once the counter reaches C<0>, and second, it ensures that
733	C<send> is called even when C<no> hosts are being pinged (the loop	782	C<send> is called even when C<no> hosts are being pinged (the loop
734	doesn't execute once).	783	doesn't execute once).
735		784
736	This is the general pattern when you "fan out" into multiple (but	785	This is the general pattern when you "fan out" into multiple (but
737	potentially none) subrequests: use an outer C<begin>/C<end> pair to set	786	potentially zero) subrequests: use an outer C<begin>/C<end> pair to set
738	the callback and ensure C<end> is called at least once, and then, for each	787	the callback and ensure C<end> is called at least once, and then, for each
739	subrequest you start, call C<begin> and for each subrequest you finish,	788	subrequest you start, call C<begin> and for each subrequest you finish,
740	call C<end>.	789	call C<end>.
741		790
742	=back	791	=back
…		…
749	=over 4	798	=over 4
750		799
751	=item $cv->recv	800	=item $cv->recv
752		801
753	Wait (blocking if necessary) until the C<< ->send >> or C<< ->croak	802	Wait (blocking if necessary) until the C<< ->send >> or C<< ->croak
754	>> methods have been called on c<$cv>, while servicing other watchers	803	>> methods have been called on C<$cv>, while servicing other watchers
755	normally.	804	normally.
756		805
757	You can only wait once on a condition - additional calls are valid but	806	You can only wait once on a condition - additional calls are valid but
758	will return immediately.	807	will return immediately.
759		808
…		…
762		811
763	In list context, all parameters passed to C<send> will be returned,	812	In list context, all parameters passed to C<send> will be returned,
764	in scalar context only the first one will be returned.	813	in scalar context only the first one will be returned.
765		814
766	Note that doing a blocking wait in a callback is not supported by any	815	Note that doing a blocking wait in a callback is not supported by any
767	event loop, that is, recursive invocation of a blocking C<< ->recv	816	event loop, that is, recursive invocation of a blocking C<< ->recv >> is
768	>> is not allowed, and the C<recv> call will C<croak> if such a	817	not allowed and the C<recv> call will C<croak> if such a condition is
769	condition is detected. This condition can be slightly loosened by using	818	detected. This requirement can be dropped by relying on L<Coro::AnyEvent>
770	L<Coro::AnyEvent>, which allows you to do a blocking C<< ->recv >> from	819	, which allows you to do a blocking C<< ->recv >> from any thread
771	any thread that doesn't run the event loop itself.	820	that doesn't run the event loop itself. L<Coro::AnyEvent> is loaded
		821	automatically when L<Coro> is used with L<AnyEvent>, so code does not need
		822	to do anything special to take advantage of that: any code that would
		823	normally block your program because it calls C<recv>, be executed in an
		824	C<async> thread instead without blocking other threads.
772		825
773	Not all event models support a blocking wait - some die in that case	826	Not all event models support a blocking wait - some die in that case
774	(programs might want to do that to stay interactive), so I<if you are	827	(programs might want to do that to stay interactive), so I<if you are
775	using this from a module, never require a blocking wait>. Instead, let the	828	using this from a module, never require a blocking wait>. Instead, let the
776	caller decide whether the call will block or not (for example, by coupling	829	caller decide whether the call will block or not (for example, by coupling
777	condition variables with some kind of request results and supporting	830	condition variables with some kind of request results and supporting
778	callbacks so the caller knows that getting the result will not block,	831	callbacks so the caller knows that getting the result will not block,
779	while still supporting blocking waits if the caller so desires).	832	while still supporting blocking waits if the caller so desires).
780		833
781	You can ensure that C<< -recv >> never blocks by setting a callback and	834	You can ensure that C<< ->recv >> never blocks by setting a callback and
782	only calling C<< ->recv >> from within that callback (or at a later	835	only calling C<< ->recv >> from within that callback (or at a later
783	time). This will work even when the event loop does not support blocking	836	time). This will work even when the event loop does not support blocking
784	waits otherwise.	837	waits otherwise.
785		838
786	=item $bool = $cv->ready	839	=item $bool = $cv->ready
…		…
791	=item $cb = $cv->cb ($cb->($cv))	844	=item $cb = $cv->cb ($cb->($cv))
792		845
793	This is a mutator function that returns the callback set and optionally	846	This is a mutator function that returns the callback set and optionally
794	replaces it before doing so.	847	replaces it before doing so.
795		848
796	The callback will be called when the condition becomes (or already was)	849	The callback will be called when the condition becomes "true", i.e. when
797	"true", i.e. when C<send> or C<croak> are called (or were called), with	850	C<send> or C<croak> are called, with the only argument being the
798	the only argument being the condition variable itself. Calling C<recv>	851	condition variable itself. If the condition is already true, the
		852	callback is called immediately when it is set. Calling C<recv> inside
799	inside the callback or at any later time is guaranteed not to block.	853	the callback or at any later time is guaranteed not to block.
800		854
801	=back	855	=back
802		856
803	=head1 SUPPORTED EVENT LOOPS/BACKENDS	857	=head1 SUPPORTED EVENT LOOPS/BACKENDS
804		858
…		…
812	use. If EV is not installed, then AnyEvent will fall back to its own	866	use. If EV is not installed, then AnyEvent will fall back to its own
813	pure-perl implementation, which is available everywhere as it comes with	867	pure-perl implementation, which is available everywhere as it comes with
814	AnyEvent itself.	868	AnyEvent itself.
815		869
816	AnyEvent::Impl::EV based on EV (interface to libev, best choice).	870	AnyEvent::Impl::EV based on EV (interface to libev, best choice).
817	AnyEvent::Impl::Perl pure-perl implementation, fast and portable.	871	AnyEvent::Impl::Perl pure-perl AnyEvent::Loop, fast and portable.
818		872
819	=item Backends that are transparently being picked up when they are used.	873	=item Backends that are transparently being picked up when they are used.
820		874
821	These will be used when they are currently loaded when the first watcher	875	These will be used if they are already loaded when the first watcher
822	is created, in which case it is assumed that the application is using	876	is created, in which case it is assumed that the application is using
823	them. This means that AnyEvent will automatically pick the right backend	877	them. This means that AnyEvent will automatically pick the right backend
824	when the main program loads an event module before anything starts to	878	when the main program loads an event module before anything starts to
825	create watchers. Nothing special needs to be done by the main program.	879	create watchers. Nothing special needs to be done by the main program.
826		880
…		…
828	AnyEvent::Impl::Glib based on Glib, slow but very stable.	882	AnyEvent::Impl::Glib based on Glib, slow but very stable.
829	AnyEvent::Impl::Tk based on Tk, very broken.	883	AnyEvent::Impl::Tk based on Tk, very broken.
830	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.	884	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
831	AnyEvent::Impl::POE based on POE, very slow, some limitations.	885	AnyEvent::Impl::POE based on POE, very slow, some limitations.
832	AnyEvent::Impl::Irssi used when running within irssi.	886	AnyEvent::Impl::Irssi used when running within irssi.
		887	AnyEvent::Impl::IOAsync based on IO::Async.
		888	AnyEvent::Impl::Cocoa based on Cocoa::EventLoop.
		889	AnyEvent::Impl::FLTK based on FLTK (fltk 2 binding).
833		890
834	=item Backends with special needs.	891	=item Backends with special needs.
835		892
836	Qt requires the Qt::Application to be instantiated first, but will	893	Qt requires the Qt::Application to be instantiated first, but will
837	otherwise be picked up automatically. As long as the main program	894	otherwise be picked up automatically. As long as the main program
838	instantiates the application before any AnyEvent watchers are created,	895	instantiates the application before any AnyEvent watchers are created,
839	everything should just work.	896	everything should just work.
840		897
841	AnyEvent::Impl::Qt based on Qt.	898	AnyEvent::Impl::Qt based on Qt.
842		899
843	Support for IO::Async can only be partial, as it is too broken and
844	architecturally limited to even support the AnyEvent API. It also
845	is the only event loop that needs the loop to be set explicitly, so
846	it can only be used by a main program knowing about AnyEvent. See
847	L<AnyEvent::Impl::Async> for the gory details.
848
849	AnyEvent::Impl::IOAsync based on IO::Async, cannot be autoprobed.
850
851	=item Event loops that are indirectly supported via other backends.	900	=item Event loops that are indirectly supported via other backends.
852		901
853	Some event loops can be supported via other modules:	902	Some event loops can be supported via other modules:
854		903
855	There is no direct support for WxWidgets (L<Wx>) or L<Prima>.	904	There is no direct support for WxWidgets (L<Wx>) or L<Prima>.
…		…
880	Contains C<undef> until the first watcher is being created, before the	929	Contains C<undef> until the first watcher is being created, before the
881	backend has been autodetected.	930	backend has been autodetected.
882		931
883	Afterwards it contains the event model that is being used, which is the	932	Afterwards it contains the event model that is being used, which is the
884	name of the Perl class implementing the model. This class is usually one	933	name of the Perl class implementing the model. This class is usually one
885	of the C<AnyEvent::Impl:xxx> modules, but can be any other class in the	934	of the C<AnyEvent::Impl::xxx> modules, but can be any other class in the
886	case AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode> it	935	case AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode> it
887	will be C<urxvt::anyevent>).	936	will be C<urxvt::anyevent>).
888		937
889	=item AnyEvent::detect	938	=item AnyEvent::detect
890		939
891	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model	940	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model
892	if necessary. You should only call this function right before you would	941	if necessary. You should only call this function right before you would
893	have created an AnyEvent watcher anyway, that is, as late as possible at	942	have created an AnyEvent watcher anyway, that is, as late as possible at
894	runtime, and not e.g. while initialising of your module.	943	runtime, and not e.g. during initialisation of your module.
		944
		945	The effect of calling this function is as if a watcher had been created
		946	(specifically, actions that happen "when the first watcher is created"
		947	happen when calling detetc as well).
895		948
896	If you need to do some initialisation before AnyEvent watchers are	949	If you need to do some initialisation before AnyEvent watchers are
897	created, use C<post_detect>.	950	created, use C<post_detect>.
898		951
899	=item $guard = AnyEvent::post_detect { BLOCK }	952	=item $guard = AnyEvent::post_detect { BLOCK }
900		953
901	Arranges for the code block to be executed as soon as the event model is	954	Arranges for the code block to be executed as soon as the event model is
902	autodetected (or immediately if this has already happened).	955	autodetected (or immediately if that has already happened).
903		956
904	The block will be executed I<after> the actual backend has been detected	957	The block will be executed I<after> the actual backend has been detected
905	(C<$AnyEvent::MODEL> is set), but I<before> any watchers have been	958	(C<$AnyEvent::MODEL> is set), but I<before> any watchers have been
906	created, so it is possible to e.g. patch C<@AnyEvent::ISA> or do	959	created, so it is possible to e.g. patch C<@AnyEvent::ISA> or do
907	other initialisations - see the sources of L<AnyEvent::Strict> or	960	other initialisations - see the sources of L<AnyEvent::Strict> or
…		…
916	that automatically removes the callback again when it is destroyed (or	969	that automatically removes the callback again when it is destroyed (or
917	C<undef> when the hook was immediately executed). See L<AnyEvent::AIO> for	970	C<undef> when the hook was immediately executed). See L<AnyEvent::AIO> for
918	a case where this is useful.	971	a case where this is useful.
919		972
920	Example: Create a watcher for the IO::AIO module and store it in	973	Example: Create a watcher for the IO::AIO module and store it in
921	C<$WATCHER>. Only do so after the event loop is initialised, though.	974	C<$WATCHER>, but do so only do so after the event loop is initialised.
922		975
923	our WATCHER;	976	our WATCHER;
924		977
925	my $guard = AnyEvent::post_detect {	978	my $guard = AnyEvent::post_detect {
926	$WATCHER = AnyEvent->io (fh => IO::AIO::poll_fileno, poll => 'r', cb => \&IO::AIO::poll_cb);	979	$WATCHER = AnyEvent->io (fh => IO::AIO::poll_fileno, poll => 'r', cb => \&IO::AIO::poll_cb);
…		…
934	$WATCHER ||= $guard;	987	$WATCHER ||= $guard;
935		988
936	=item @AnyEvent::post_detect	989	=item @AnyEvent::post_detect
937		990
938	If there are any code references in this array (you can C<push> to it	991	If there are any code references in this array (you can C<push> to it
939	before or after loading AnyEvent), then they will called directly after	992	before or after loading AnyEvent), then they will be called directly
940	the event loop has been chosen.	993	after the event loop has been chosen.
941		994
942	You should check C<$AnyEvent::MODEL> before adding to this array, though:	995	You should check C<$AnyEvent::MODEL> before adding to this array, though:
943	if it is defined then the event loop has already been detected, and the	996	if it is defined then the event loop has already been detected, and the
944	array will be ignored.	997	array will be ignored.
945		998
946	Best use C<AnyEvent::post_detect { BLOCK }> when your application allows	999	Best use C<AnyEvent::post_detect { BLOCK }> when your application allows
947	it,as it takes care of these details.	1000	it, as it takes care of these details.
948		1001
949	This variable is mainly useful for modules that can do something useful	1002	This variable is mainly useful for modules that can do something useful
950	when AnyEvent is used and thus want to know when it is initialised, but do	1003	when AnyEvent is used and thus want to know when it is initialised, but do
951	not need to even load it by default. This array provides the means to hook	1004	not need to even load it by default. This array provides the means to hook
952	into AnyEvent passively, without loading it.	1005	into AnyEvent passively, without loading it.
953		1006
		1007	Example: To load Coro::AnyEvent whenever Coro and AnyEvent are used
		1008	together, you could put this into Coro (this is the actual code used by
		1009	Coro to accomplish this):
		1010
		1011	if (defined $AnyEvent::MODEL) {
		1012	# AnyEvent already initialised, so load Coro::AnyEvent
		1013	require Coro::AnyEvent;
		1014	} else {
		1015	# AnyEvent not yet initialised, so make sure to load Coro::AnyEvent
		1016	# as soon as it is
		1017	push @AnyEvent::post_detect, sub { require Coro::AnyEvent };
		1018	}
		1019
		1020	=item AnyEvent::postpone { BLOCK }
		1021
		1022	Arranges for the block to be executed as soon as possible, but not before
		1023	the call itself returns. In practise, the block will be executed just
		1024	before the event loop polls for new events, or shortly afterwards.
		1025
		1026	This function never returns anything (to make the C<return postpone { ...
		1027	}> idiom more useful.
		1028
		1029	To understand the usefulness of this function, consider a function that
		1030	asynchronously does something for you and returns some transaction
		1031	object or guard to let you cancel the operation. For example,
		1032	C<AnyEvent::Socket::tcp_connect>:
		1033
		1034	# start a conenction attempt unless one is active
		1035	$self->{connect_guard} ||= AnyEvent::Socket::tcp_connect "www.example.net", 80, sub {
		1036	delete $self->{connect_guard};
		1037	...
		1038	};
		1039
		1040	Imagine that this function could instantly call the callback, for
		1041	example, because it detects an obvious error such as a negative port
		1042	number. Invoking the callback before the function returns causes problems
		1043	however: the callback will be called and will try to delete the guard
		1044	object. But since the function hasn't returned yet, there is nothing to
		1045	delete. When the function eventually returns it will assign the guard
		1046	object to C<< $self->{connect_guard} >>, where it will likely never be
		1047	deleted, so the program thinks it is still trying to connect.
		1048
		1049	This is where C<AnyEvent::postpone> should be used. Instead of calling the
		1050	callback directly on error:
		1051
		1052	$cb->(undef), return # signal error to callback, BAD!
		1053	if $some_error_condition;
		1054
		1055	It should use C<postpone>:
		1056
		1057	AnyEvent::postpone { $cb->(undef) }, return # signal error to callback, later
		1058	if $some_error_condition;
		1059
		1060	=item AnyEvent::log $level, $msg[, @args]
		1061
		1062	Log the given C<$msg> at the given C<$level>.
		1063
		1064	If L<AnyEvent::Log> is not loaded then this function makes a simple test
		1065	to see whether the message will be logged. If the test succeeds it will
		1066	load AnyEvent::Log and call C<AnyEvent::Log::log> - consequently, look at
		1067	the L<AnyEvent::Log> documentation for details.
		1068
		1069	If the test fails it will simply return. Right now this happens when a
		1070	numerical loglevel is used and it is larger than the level specified via
		1071	C<$ENV{PERL_ANYEVENT_VERBOSE}>.
		1072
		1073	If you want to sprinkle loads of logging calls around your code, consider
		1074	creating a logger callback with the C<AnyEvent::Log::logger> function,
		1075	which can reduce typing, codesize and can reduce the logging overhead
		1076	enourmously.
		1077
954	=back	1078	=back
955		1079
956	=head1 WHAT TO DO IN A MODULE	1080	=head1 WHAT TO DO IN A MODULE
957		1081
958	As a module author, you should C<use AnyEvent> and call AnyEvent methods	1082	As a module author, you should C<use AnyEvent> and call AnyEvent methods
…		…
968	because it will stall the whole program, and the whole point of using	1092	because it will stall the whole program, and the whole point of using
969	events is to stay interactive.	1093	events is to stay interactive.
970		1094
971	It is fine, however, to call C<< ->recv >> when the user of your module	1095	It is fine, however, to call C<< ->recv >> when the user of your module
972	requests it (i.e. if you create a http request object ad have a method	1096	requests it (i.e. if you create a http request object ad have a method
973	called C<results> that returns the results, it should call C<< ->recv >>	1097	called C<results> that returns the results, it may call C<< ->recv >>
974	freely, as the user of your module knows what she is doing. always).	1098	freely, as the user of your module knows what she is doing. Always).
975		1099
976	=head1 WHAT TO DO IN THE MAIN PROGRAM	1100	=head1 WHAT TO DO IN THE MAIN PROGRAM
977		1101
978	There will always be a single main program - the only place that should	1102	There will always be a single main program - the only place that should
979	dictate which event model to use.	1103	dictate which event model to use.
980		1104
981	If it doesn't care, it can just "use AnyEvent" and use it itself, or not	1105	If the program is not event-based, it need not do anything special, even
982	do anything special (it does not need to be event-based) and let AnyEvent	1106	when it depends on a module that uses an AnyEvent. If the program itself
983	decide which implementation to chose if some module relies on it.	1107	uses AnyEvent, but does not care which event loop is used, all it needs
		1108	to do is C<use AnyEvent>. In either case, AnyEvent will choose the best
		1109	available loop implementation.
984		1110
985	If the main program relies on a specific event model - for example, in	1111	If the main program relies on a specific event model - for example, in
986	Gtk2 programs you have to rely on the Glib module - you should load the	1112	Gtk2 programs you have to rely on the Glib module - you should load the
987	event module before loading AnyEvent or any module that uses it: generally	1113	event module before loading AnyEvent or any module that uses it: generally
988	speaking, you should load it as early as possible. The reason is that	1114	speaking, you should load it as early as possible. The reason is that
989	modules might create watchers when they are loaded, and AnyEvent will	1115	modules might create watchers when they are loaded, and AnyEvent will
990	decide on the event model to use as soon as it creates watchers, and it	1116	decide on the event model to use as soon as it creates watchers, and it
991	might chose the wrong one unless you load the correct one yourself.	1117	might choose the wrong one unless you load the correct one yourself.
992		1118
993	You can chose to use a pure-perl implementation by loading the	1119	You can chose to use a pure-perl implementation by loading the
994	C<AnyEvent::Impl::Perl> module, which gives you similar behaviour	1120	C<AnyEvent::Loop> module, which gives you similar behaviour
995	everywhere, but letting AnyEvent chose the model is generally better.	1121	everywhere, but letting AnyEvent chose the model is generally better.
996		1122
997	=head2 MAINLOOP EMULATION	1123	=head2 MAINLOOP EMULATION
998		1124
999	Sometimes (often for short test scripts, or even standalone programs who	1125	Sometimes (often for short test scripts, or even standalone programs who
…		…
1012		1138
1013		1139
1014	=head1 OTHER MODULES	1140	=head1 OTHER MODULES
1015		1141
1016	The following is a non-exhaustive list of additional modules that use	1142	The following is a non-exhaustive list of additional modules that use
1017	AnyEvent as a client and can therefore be mixed easily with other AnyEvent	1143	AnyEvent as a client and can therefore be mixed easily with other
1018	modules and other event loops in the same program. Some of the modules	1144	AnyEvent modules and other event loops in the same program. Some of the
1019	come with AnyEvent, most are available via CPAN.	1145	modules come as part of AnyEvent, the others are available via CPAN (see
		1146	L<http://search.cpan.org/search?m=module&q=anyevent%3A%3A*> for
		1147	a longer non-exhaustive list), and the list is heavily biased towards
		1148	modules of the AnyEvent author himself :)
1020		1149
1021	=over 4	1150	=over 4
1022		1151
1023	=item L<AnyEvent::Util>	1152	=item L<AnyEvent::Util>
1024		1153
1025	Contains various utility functions that replace often-used but blocking	1154	Contains various utility functions that replace often-used blocking
1026	functions such as C<inet_aton> by event-/callback-based versions.	1155	functions such as C<inet_aton> with event/callback-based versions.
1027		1156
1028	=item L<AnyEvent::Socket>	1157	=item L<AnyEvent::Socket>
1029		1158
1030	Provides various utility functions for (internet protocol) sockets,	1159	Provides various utility functions for (internet protocol) sockets,
1031	addresses and name resolution. Also functions to create non-blocking tcp	1160	addresses and name resolution. Also functions to create non-blocking tcp
…		…
1033		1162
1034	=item L<AnyEvent::Handle>	1163	=item L<AnyEvent::Handle>
1035		1164
1036	Provide read and write buffers, manages watchers for reads and writes,	1165	Provide read and write buffers, manages watchers for reads and writes,
1037	supports raw and formatted I/O, I/O queued and fully transparent and	1166	supports raw and formatted I/O, I/O queued and fully transparent and
1038	non-blocking SSL/TLS (via L<AnyEvent::TLS>.	1167	non-blocking SSL/TLS (via L<AnyEvent::TLS>).
1039		1168
1040	=item L<AnyEvent::DNS>	1169	=item L<AnyEvent::DNS>
1041		1170
1042	Provides rich asynchronous DNS resolver capabilities.	1171	Provides rich asynchronous DNS resolver capabilities.
1043		1172
		1173	=item L<AnyEvent::HTTP>, L<AnyEvent::IRC>, L<AnyEvent::XMPP>, L<AnyEvent::GPSD>, L<AnyEvent::IGS>, L<AnyEvent::FCP>
		1174
		1175	Implement event-based interfaces to the protocols of the same name (for
		1176	the curious, IGS is the International Go Server and FCP is the Freenet
		1177	Client Protocol).
		1178
1044	=item L<AnyEvent::HTTP>	1179	=item L<AnyEvent::AIO>
1045		1180
1046	A simple-to-use HTTP library that is capable of making a lot of concurrent	1181	Truly asynchronous (as opposed to non-blocking) I/O, should be in the
1047	HTTP requests.	1182	toolbox of every event programmer. AnyEvent::AIO transparently fuses
		1183	L<IO::AIO> and AnyEvent together, giving AnyEvent access to event-based
		1184	file I/O, and much more.
		1185
		1186	=item L<AnyEvent::Filesys::Notify>
		1187
		1188	AnyEvent is good for non-blocking stuff, but it can't detect file or
		1189	path changes (e.g. "watch this directory for new files", "watch this
		1190	file for changes"). The L<AnyEvent::Filesys::Notify> module promises to
		1191	do just that in a portbale fashion, supporting inotify on GNU/Linux and
		1192	some weird, without doubt broken, stuff on OS X to monitor files. It can
		1193	fall back to blocking scans at regular intervals transparently on other
		1194	platforms, so it's about as portable as it gets.
		1195
		1196	(I haven't used it myself, but I haven't heard anybody complaining about
		1197	it yet).
		1198
		1199	=item L<AnyEvent::DBI>
		1200
		1201	Executes L<DBI> requests asynchronously in a proxy process for you,
		1202	notifying you in an event-based way when the operation is finished.
1048		1203
1049	=item L<AnyEvent::HTTPD>	1204	=item L<AnyEvent::HTTPD>
1050		1205
1051	Provides a simple web application server framework.	1206	A simple embedded webserver.
1052		1207
1053	=item L<AnyEvent::FastPing>	1208	=item L<AnyEvent::FastPing>
1054		1209
1055	The fastest ping in the west.	1210	The fastest ping in the west.
1056		1211
1057	=item L<AnyEvent::DBI>
1058
1059	Executes L<DBI> requests asynchronously in a proxy process.
1060
1061	=item L<AnyEvent::AIO>
1062
1063	Truly asynchronous I/O, should be in the toolbox of every event
1064	programmer. AnyEvent::AIO transparently fuses L<IO::AIO> and AnyEvent
1065	together.
1066
1067	=item L<AnyEvent::BDB>
1068
1069	Truly asynchronous Berkeley DB access. AnyEvent::BDB transparently fuses
1070	L<BDB> and AnyEvent together.
1071
1072	=item L<AnyEvent::GPSD>
1073
1074	A non-blocking interface to gpsd, a daemon delivering GPS information.
1075
1076	=item L<AnyEvent::IRC>
1077
1078	AnyEvent based IRC client module family (replacing the older Net::IRC3).
1079
1080	=item L<AnyEvent::XMPP>
1081
1082	AnyEvent based XMPP (Jabber protocol) module family (replacing the older
1083	Net::XMPP2>.
1084
1085	=item L<AnyEvent::IGS>
1086
1087	A non-blocking interface to the Internet Go Server protocol (used by
1088	L<App::IGS>).
1089
1090	=item L<Net::FCP>
1091
1092	AnyEvent-based implementation of the Freenet Client Protocol, birthplace
1093	of AnyEvent.
1094
1095	=item L<Event::ExecFlow>
1096
1097	High level API for event-based execution flow control.
1098
1099	=item L<Coro>	1212	=item L<Coro>
1100		1213
1101	Has special support for AnyEvent via L<Coro::AnyEvent>.	1214	Has special support for AnyEvent via L<Coro::AnyEvent>, which allows you
		1215	to simply invert the flow control - don't call us, we will call you:
		1216
		1217	async {
		1218	Coro::AnyEvent::sleep 5; # creates a 5s timer and waits for it
		1219	print "5 seconds later!\n";
		1220
		1221	Coro::AnyEvent::readable *STDIN; # uses an I/O watcher
		1222	my $line = <STDIN>; # works for ttys
		1223
		1224	AnyEvent::HTTP::http_get "url", Coro::rouse_cb;
		1225	my ($body, $hdr) = Coro::rouse_wait;
		1226	};
1102		1227
1103	=back	1228	=back
1104		1229
1105	=cut	1230	=cut
1106		1231
1107	package AnyEvent;	1232	package AnyEvent;
1108		1233
1109	# basically a tuned-down version of common::sense	1234	# basically a tuned-down version of common::sense
1110	sub common_sense {	1235	sub common_sense {
1111	# from common:.sense 1.0	1236	# from common:.sense 3.5
		1237	local $^W;
1112	${^WARNING_BITS} = "\xfc\x3f\xf3\x00\x0f\xf3\xcf\xc0\xf3\xfc\x33\x03";	1238	${^WARNING_BITS} ^= ${^WARNING_BITS} ^ "\x3c\x3f\x33\x00\x0f\xf0\x0f\xc0\xf0\xfc\x33\x00";
1113	# use strict vars subs	1239	# use strict vars subs - NO UTF-8, as Util.pm doesn't like this atm. (uts46data.pl)
1114	$^H |= 0x00000600;	1240	$^H |= 0x00000600;
1115	}	1241	}
1116		1242
1117	BEGIN { AnyEvent::common_sense }	1243	BEGIN { AnyEvent::common_sense }
1118		1244
1119	use Carp ();	1245	use Carp ();
1120		1246
1121	our $VERSION = '5.202';	1247	our $VERSION = '7.04';
1122	our $MODEL;	1248	our $MODEL;
1123
1124	our $AUTOLOAD;
1125	our @ISA;	1249	our @ISA;
1126
1127	our @REGISTRY;	1250	our @REGISTRY;
1128
1129	our $WIN32;
1130
1131	our $VERBOSE;	1251	our $VERBOSE;
		1252	our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred
		1253	our $MAX_SIGNAL_LATENCY = $ENV{PERL_ANYEVENT_MAX_SIGNAL_LATENCY} || 10; # executes after the BEGIN block below (tainting!)
1132		1254
1133	BEGIN {	1255	BEGIN {
1134	eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }";	1256	require "AnyEvent/constants.pl";
		1257
1135	eval "sub TAINT(){ " . (${^TAINT}*1) . " }";	1258	eval "sub TAINT (){" . (${^TAINT}*1) . "}";
1136		1259
1137	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}	1260	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}
1138	if ${^TAINT};	1261	if ${^TAINT};
1139		1262
1140	$VERBOSE = $ENV{PERL_ANYEVENT_VERBOSE}*1;	1263	$ENV{"PERL_ANYEVENT_$_"} = $ENV{"AE_$_"}
		1264	for grep s/^AE_// && !exists $ENV{"PERL_ANYEVENT_$_"}, keys %ENV;
1141		1265
1142	}	1266	@ENV{grep /^PERL_ANYEVENT_/, keys %ENV} = ()
		1267	if ${^TAINT};
1143		1268
1144	our $MAX_SIGNAL_LATENCY = 10;	1269	# $ENV{PERL_ANYEVENT_xxx} now valid
1145		1270
1146	our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred	1271	$VERBOSE = length $ENV{PERL_ANYEVENT_VERBOSE} ? $ENV{PERL_ANYEVENT_VERBOSE}*1 : 4;
1147		1272
1148	{
1149	my $idx;	1273	my $idx;
1150	$PROTOCOL{$_} = ++$idx	1274	$PROTOCOL{$_} = ++$idx
1151	for reverse split /\s*,\s*/,	1275	for reverse split /\s*,\s*/,
1152	$ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";	1276	$ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";
1153	}	1277	}
1154		1278
		1279	our @post_detect;
		1280
		1281	sub post_detect(&) {
		1282	my ($cb) = @_;
		1283
		1284	push @post_detect, $cb;
		1285
		1286	defined wantarray
		1287	? bless \$cb, "AnyEvent::Util::postdetect"
		1288	: ()
		1289	}
		1290
		1291	sub AnyEvent::Util::postdetect::DESTROY {
		1292	@post_detect = grep $_ != ${$_[0]}, @post_detect;
		1293	}
		1294
		1295	our $POSTPONE_W;
		1296	our @POSTPONE;
		1297
		1298	sub _postpone_exec {
		1299	undef $POSTPONE_W;
		1300
		1301	&{ shift @POSTPONE }
		1302	while @POSTPONE;
		1303	}
		1304
		1305	sub postpone(&) {
		1306	push @POSTPONE, shift;
		1307
		1308	$POSTPONE_W ||= AE::timer (0, 0, \&_postpone_exec);
		1309
		1310	()
		1311	}
		1312
		1313	sub log($$;@) {
		1314	# only load the big bloated module when we actually are about to log something
		1315	if ($_[0] <= ($VERBOSE || 1)) { # also catches non-numeric levels(!) and fatal
		1316	local ($!, $@);
		1317	require AnyEvent::Log; # among other things, sets $VERBOSE to 9
		1318	# AnyEvent::Log overwrites this function
		1319	goto &log;
		1320	}
		1321
		1322	0 # not logged
		1323	}
		1324
		1325	sub _logger($;$) {
		1326	my ($level, $renabled) = @_;
		1327
		1328	$$renabled = $level <= $VERBOSE;
		1329
		1330	my $logger = [(caller)[0], $level, $renabled];
		1331
		1332	$AnyEvent::Log::LOGGER{$logger+0} = $logger;
		1333
		1334	# return unless defined wantarray;
		1335	#
		1336	# require AnyEvent::Util;
		1337	# my $guard = AnyEvent::Util::guard (sub {
		1338	# # "clean up"
		1339	# delete $LOGGER{$logger+0};
		1340	# });
		1341	#
		1342	# sub {
		1343	# return 0 unless $$renabled;
		1344	#
		1345	# $guard if 0; # keep guard alive, but don't cause runtime overhead
		1346	# require AnyEvent::Log unless $AnyEvent::Log::VERSION;
		1347	# package AnyEvent::Log;
		1348	# _log ($logger->[0], $level, @_) # logger->[0] has been converted at load time
		1349	# }
		1350	}
		1351
		1352	if (length $ENV{PERL_ANYEVENT_LOG}) {
		1353	require AnyEvent::Log; # AnyEvent::Log does the thing for us
		1354	}
		1355
1155	my @models = (	1356	our @models = (
1156	[EV:: => AnyEvent::Impl::EV:: , 1],	1357	[EV:: => AnyEvent::Impl::EV::],
1157	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl:: , 1],	1358	[AnyEvent::Loop:: => AnyEvent::Impl::Perl::],
1158	# everything below here will not (normally) be autoprobed	1359	# everything below here will not (normally) be autoprobed
1159	# as the pureperl backend should work everywhere	1360	# as the pure perl backend should work everywhere
1160	# and is usually faster	1361	# and is usually faster
		1362	[Irssi:: => AnyEvent::Impl::Irssi::], # Irssi has a bogus "Event" package, so msut be near the top
1161	[Event:: => AnyEvent::Impl::Event::, 1],	1363	[Event:: => AnyEvent::Impl::Event::], # slow, stable
1162	[Glib:: => AnyEvent::Impl::Glib:: , 1], # becomes extremely slow with many watchers	1364	[Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers
		1365	# everything below here should not be autoloaded
1163	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy	1366	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
1164	[Irssi:: => AnyEvent::Impl::Irssi::], # Irssi has a bogus "Event" package
1165	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles	1367	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
1166	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program	1368	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program
1167	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza	1369	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
1168	[Wx:: => AnyEvent::Impl::POE::],	1370	[Wx:: => AnyEvent::Impl::POE::],
1169	[Prima:: => AnyEvent::Impl::POE::],	1371	[Prima:: => AnyEvent::Impl::POE::],
1170	# IO::Async is just too broken - we would need workarounds for its	1372	[IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # a bitch to autodetect
1171	# byzantine signal and broken child handling, among others.	1373	[Cocoa::EventLoop:: => AnyEvent::Impl::Cocoa::],
1172	# IO::Async is rather hard to detect, as it doesn't have any	1374	[FLTK:: => AnyEvent::Impl::FLTK::],
1173	# obvious default class.
1174	[IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program
1175	[IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program
1176	[IO::Async::Notifier:: => AnyEvent::Impl::IOAsync::], # requires special main program
1177	[AnyEvent::Impl::IOAsync:: => AnyEvent::Impl::IOAsync::], # requires special main program
1178	);	1375	);
1179		1376
1180	our %method = map +($_ => 1),	1377	our @isa_hook;
		1378
		1379	sub _isa_set {
		1380	my @pkg = ("AnyEvent", (map $_->[0], grep defined, @isa_hook), $MODEL);
		1381
		1382	@{"$pkg[$_-1]::ISA"} = $pkg[$_]
		1383	for 1 .. $#pkg;
		1384
		1385	grep $_ && $_->[1], @isa_hook
		1386	and AE::_reset ();
		1387	}
		1388
		1389	# used for hooking AnyEvent::Strict and AnyEvent::Debug::Wrap into the class hierarchy
		1390	sub _isa_hook($$;$) {
		1391	my ($i, $pkg, $reset_ae) = @_;
		1392
		1393	$isa_hook[$i] = $pkg ? [$pkg, $reset_ae] : undef;
		1394
		1395	_isa_set;
		1396	}
		1397
		1398	# all autoloaded methods reserve the complete glob, not just the method slot.
		1399	# due to bugs in perls method cache implementation.
1181	qw(io timer time now now_update signal child idle condvar one_event DESTROY);	1400	our @methods = qw(io timer time now now_update signal child idle condvar);
1182		1401
1183	our @post_detect;
1184
1185	sub post_detect(&) {	1402	sub detect() {
1186	my ($cb) = @_;	1403	return $MODEL if $MODEL; # some programs keep references to detect
1187		1404
1188	if ($MODEL) {	1405	# IO::Async::Loop::AnyEvent is extremely evil, refuse to work with it
1189	$cb->();	1406	# the author knows about the problems and what it does to AnyEvent as a whole
		1407	# (and the ability of others to use AnyEvent), but simply wants to abuse AnyEvent
		1408	# anyway.
		1409	AnyEvent::log fatal => "IO::Async::Loop::AnyEvent detected - that module is broken by\n"
		1410	. "design, abuses internals and breaks AnyEvent - will not continue."
		1411	if exists $INC{"IO/Async/Loop/AnyEvent.pm"};
1190		1412
1191	undef	1413	local $!; # for good measure
		1414	local $SIG{__DIE__}; # we use eval
		1415
		1416	# free some memory
		1417	*detect = sub () { $MODEL };
		1418	# undef &func doesn't correctly update the method cache. grmbl.
		1419	# so we delete the whole glob. grmbl.
		1420	# otoh, perl doesn't let me undef an active usb, but it lets me free
		1421	# a glob with an active sub. hrm. i hope it works, but perl is
		1422	# usually buggy in this department. sigh.
		1423	delete @{"AnyEvent::"}{@methods};
		1424	undef @methods;
		1425
		1426	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z0-9:]+)$/) {
		1427	my $model = $1;
		1428	$model = "AnyEvent::Impl::$model" unless $model =~ s/::$//;
		1429	if (eval "require $model") {
		1430	AnyEvent::log 7 => "Loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.";
		1431	$MODEL = $model;
1192	} else {	1432	} else {
1193	push @post_detect, $cb;	1433	AnyEvent::log 4 => "Unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@";
1194		1434	}
1195	defined wantarray
1196	? bless \$cb, "AnyEvent::Util::postdetect"
1197	: ()
1198	}	1435	}
1199	}
1200		1436
1201	sub AnyEvent::Util::postdetect::DESTROY {	1437	# check for already loaded models
1202	@post_detect = grep $_ != ${$_[0]}, @post_detect;
1203	}
1204
1205	sub detect() {
1206	unless ($MODEL) {	1438	unless ($MODEL) {
1207	local $SIG{__DIE__};	1439	for (@REGISTRY, @models) {
1208		1440	my ($package, $model) = @$_;
1209	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {	1441	if (${"$package\::VERSION"} > 0) {
1210	my $model = "AnyEvent::Impl::$1";
1211	if (eval "require $model") {	1442	if (eval "require $model") {
		1443	AnyEvent::log 7 => "Autodetected model '$model', using it.";
1212	$MODEL = $model;	1444	$MODEL = $model;
1213	warn "AnyEvent: loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.\n" if $VERBOSE >= 2;	1445	last;
1214	} else {	1446	} else {
1215	warn "AnyEvent: unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@" if $VERBOSE;	1447	AnyEvent::log 8 => "Detected event loop $package, but cannot load '$model', skipping: $@";
		1448	}
1216	}	1449	}
1217	}	1450	}
1218		1451
1219	# check for already loaded models
1220	unless ($MODEL) {	1452	unless ($MODEL) {
		1453	# try to autoload a model
1221	for (@REGISTRY, @models) {	1454	for (@REGISTRY, @models) {
1222	my ($package, $model) = @$_;	1455	my ($package, $model) = @$_;
		1456	if (
		1457	eval "require $package"
1223	if (${"$package\::VERSION"} > 0) {	1458	and ${"$package\::VERSION"} > 0
1224	if (eval "require $model") {	1459	and eval "require $model"
		1460	) {
		1461	AnyEvent::log 7 => "Autoloaded model '$model', using it.";
1225	$MODEL = $model;	1462	$MODEL = $model;
1226	warn "AnyEvent: autodetected model '$model', using it.\n" if $VERBOSE >= 2;
1227	last;	1463	last;
1228	}
1229	}	1464	}
1230	}	1465	}
1231		1466
1232	unless ($MODEL) {
1233	# try to autoload a model
1234	for (@REGISTRY, @models) {
1235	my ($package, $model, $autoload) = @$_;
1236	if (
1237	$autoload
1238	and eval "require $package"
1239	and ${"$package\::VERSION"} > 0
1240	and eval "require $model"
1241	) {
1242	$MODEL = $model;
1243	warn "AnyEvent: autoloaded model '$model', using it.\n" if $VERBOSE >= 2;
1244	last;
1245	}
1246	}
1247
1248	$MODEL	1467	$MODEL
1249	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.\n";	1468	or AnyEvent::log fatal => "Backend autodetection failed - did you properly install AnyEvent?";
1250	}
1251	}	1469	}
1252
1253	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
1254
1255	unshift @ISA, $MODEL;
1256
1257	require AnyEvent::Strict if $ENV{PERL_ANYEVENT_STRICT};
1258
1259	(shift @post_detect)->() while @post_detect;
1260	}	1470	}
1261		1471
		1472	# free memory only needed for probing
		1473	undef @models;
		1474	undef @REGISTRY;
		1475
		1476	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
		1477
		1478	# now nuke some methods that are overridden by the backend.
		1479	# SUPER usage is not allowed in these.
		1480	for (qw(time signal child idle)) {
		1481	undef &{"AnyEvent::Base::$_"}
		1482	if defined &{"$MODEL\::$_"};
		1483	}
		1484
		1485	_isa_set;
		1486
		1487	# we're officially open!
		1488
		1489	if ($ENV{PERL_ANYEVENT_STRICT}) {
		1490	require AnyEvent::Strict;
		1491	}
		1492
		1493	if ($ENV{PERL_ANYEVENT_DEBUG_WRAP}) {
		1494	require AnyEvent::Debug;
		1495	AnyEvent::Debug::wrap ($ENV{PERL_ANYEVENT_DEBUG_WRAP});
		1496	}
		1497
		1498	if (length $ENV{PERL_ANYEVENT_DEBUG_SHELL}) {
		1499	require AnyEvent::Socket;
		1500	require AnyEvent::Debug;
		1501
		1502	my $shell = $ENV{PERL_ANYEVENT_DEBUG_SHELL};
		1503	$shell =~ s/\$\$/$$/g;
		1504
		1505	my ($host, $service) = AnyEvent::Socket::parse_hostport ($shell);
		1506	$AnyEvent::Debug::SHELL = AnyEvent::Debug::shell ($host, $service);
		1507	}
		1508
		1509	# now the anyevent environment is set up as the user told us to, so
		1510	# call the actual user code - post detects
		1511
		1512	(shift @post_detect)->() while @post_detect;
		1513	undef @post_detect;
		1514
		1515	*post_detect = sub(&) {
		1516	shift->();
		1517
		1518	undef
		1519	};
		1520
1262	$MODEL	1521	$MODEL
1263	}	1522	}
1264		1523
1265	sub AUTOLOAD {	1524	for my $name (@methods) {
1266	(my $func = $AUTOLOAD) =~ s/.*://;	1525	*$name = sub {
1267		1526	detect;
1268	$method{$func}	1527	# we use goto because
1269	or Carp::croak "$func: not a valid method for AnyEvent objects";	1528	# a) it makes the thunk more transparent
1270		1529	# b) it allows us to delete the thunk later
1271	detect unless $MODEL;	1530	goto &{ UNIVERSAL::can AnyEvent => "SUPER::$name" }
1272		1531	};
1273	my $class = shift;
1274	$class->$func (@_);
1275	}	1532	}
1276		1533
1277	# utility function to dup a filehandle. this is used by many backends	1534	# utility function to dup a filehandle. this is used by many backends
1278	# to support binding more than one watcher per filehandle (they usually	1535	# to support binding more than one watcher per filehandle (they usually
1279	# allow only one watcher per fd, so we dup it to get a different one).	1536	# allow only one watcher per fd, so we dup it to get a different one).
…		…
1293		1550
1294	=head1 SIMPLIFIED AE API	1551	=head1 SIMPLIFIED AE API
1295		1552
1296	Starting with version 5.0, AnyEvent officially supports a second, much	1553	Starting with version 5.0, AnyEvent officially supports a second, much
1297	simpler, API that is designed to reduce the calling, typing and memory	1554	simpler, API that is designed to reduce the calling, typing and memory
1298	overhead.	1555	overhead by using function call syntax and a fixed number of parameters.
1299		1556
1300	See the L<AE> manpage for details.	1557	See the L<AE> manpage for details.
1301		1558
1302	=cut	1559	=cut
1303		1560
1304	package AE;	1561	package AE;
1305		1562
1306	our $VERSION = $AnyEvent::VERSION;	1563	our $VERSION = $AnyEvent::VERSION;
1307		1564
		1565	sub _reset() {
		1566	eval q{
		1567	# fall back to the main API by default - backends and AnyEvent::Base
		1568	# implementations can overwrite these.
		1569
1308	sub io($$$) {	1570	sub io($$$) {
1309	AnyEvent->io (fh => $_[0], poll => $_[1] ? "w" : "r", cb => $_[2])	1571	AnyEvent->io (fh => $_[0], poll => $_[1] ? "w" : "r", cb => $_[2])
1310	}	1572	}
1311		1573
1312	sub timer($$$) {	1574	sub timer($$$) {
1313	AnyEvent->timer (after => $_[0], interval => $_[1], cb => $_[2])	1575	AnyEvent->timer (after => $_[0], interval => $_[1], cb => $_[2])
1314	}	1576	}
1315		1577
1316	sub signal($$) {	1578	sub signal($$) {
1317	AnyEvent->signal (signal => $_[0], cb => $_[1])	1579	AnyEvent->signal (signal => $_[0], cb => $_[1])
1318	}	1580	}
1319		1581
1320	sub child($$) {	1582	sub child($$) {
1321	AnyEvent->child (pid => $_[0], cb => $_[1])	1583	AnyEvent->child (pid => $_[0], cb => $_[1])
1322	}	1584	}
1323		1585
1324	sub idle($) {	1586	sub idle($) {
1325	AnyEvent->idle (cb => $_[0])	1587	AnyEvent->idle (cb => $_[0]);
1326	}	1588	}
1327		1589
1328	sub cv(;&) {	1590	sub cv(;&) {
1329	AnyEvent->condvar (@_ ? (cb => $_[0]) : ())	1591	AnyEvent->condvar (@_ ? (cb => $_[0]) : ())
1330	}	1592	}
1331		1593
1332	sub now() {	1594	sub now() {
1333	AnyEvent->now	1595	AnyEvent->now
1334	}	1596	}
1335		1597
1336	sub now_update() {	1598	sub now_update() {
1337	AnyEvent->now_update	1599	AnyEvent->now_update
1338	}	1600	}
1339		1601
1340	sub time() {	1602	sub time() {
1341	AnyEvent->time	1603	AnyEvent->time
		1604	}
		1605
		1606	*postpone = \&AnyEvent::postpone;
		1607	*log = \&AnyEvent::log;
		1608	};
		1609	die if $@;
1342	}	1610	}
		1611
		1612	BEGIN { _reset }
1343		1613
1344	package AnyEvent::Base;	1614	package AnyEvent::Base;
1345		1615
1346	# default implementations for many methods	1616	# default implementations for many methods
1347		1617
1348	sub _time() {	1618	sub time {
		1619	eval q{ # poor man's autoloading {}
1349	# probe for availability of Time::HiRes	1620	# probe for availability of Time::HiRes
1350	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {	1621	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {
1351	warn "AnyEvent: using Time::HiRes for sub-second timing accuracy.\n" if $VERBOSE >= 8;	1622	*time = sub { Time::HiRes::time () };
1352	*_time = \&Time::HiRes::time;	1623	*AE::time = \& Time::HiRes::time ;
		1624	*now = \&time;
		1625	AnyEvent::log 8 => "using Time::HiRes for sub-second timing accuracy.";
1353	# if (eval "use POSIX (); (POSIX::times())...	1626	# if (eval "use POSIX (); (POSIX::times())...
1354	} else {	1627	} else {
1355	warn "AnyEvent: using built-in time(), WARNING, no sub-second resolution!\n" if $VERBOSE;	1628	*time = sub { CORE::time };
1356	*_time = sub { time }; # epic fail	1629	*AE::time = sub (){ CORE::time };
		1630	*now = \&time;
		1631	AnyEvent::log 3 => "Using built-in time(), no sub-second resolution!";
		1632	}
1357	}	1633	};
		1634	die if $@;
1358		1635
1359	&_time	1636	&time
1360	}	1637	}
1361		1638
1362	sub time { _time }	1639	*now = \&time;
1363	sub now { _time }
1364	sub now_update { }	1640	sub now_update { }
1365		1641
		1642	sub _poll {
		1643	Carp::croak "$AnyEvent::MODEL does not support blocking waits. Caught";
		1644	}
		1645
1366	# default implementation for ->condvar	1646	# default implementation for ->condvar
		1647	# in fact, the default should not be overwritten
1367		1648
1368	sub condvar {	1649	sub condvar {
		1650	eval q{ # poor man's autoloading {}
		1651	*condvar = sub {
1369	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"	1652	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"
		1653	};
		1654
		1655	*AE::cv = sub (;&) {
		1656	bless { @_ ? (_ae_cb => shift) : () }, "AnyEvent::CondVar"
		1657	};
		1658	};
		1659	die if $@;
		1660
		1661	&condvar
1370	}	1662	}
1371		1663
1372	# default implementation for ->signal	1664	# default implementation for ->signal
1373		1665
1374	our $HAVE_ASYNC_INTERRUPT;	1666	our $HAVE_ASYNC_INTERRUPT;
…		…
1383		1675
1384	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);	1676	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);
1385	our (%SIG_ASY, %SIG_ASY_W);	1677	our (%SIG_ASY, %SIG_ASY_W);
1386	our ($SIG_COUNT, $SIG_TW);	1678	our ($SIG_COUNT, $SIG_TW);
1387		1679
1388	sub _signal_exec {
1389	$HAVE_ASYNC_INTERRUPT
1390	? $SIGPIPE_R->drain
1391	: sysread $SIGPIPE_R, (my $dummy), 9;
1392
1393	while (%SIG_EV) {
1394	for (keys %SIG_EV) {
1395	delete $SIG_EV{$_};
1396	$_->() for values %{ $SIG_CB{$_} || {} };
1397	}
1398	}
1399	}
1400
1401	# install a dummy wakeup watcher to reduce signal catching latency	1680	# install a dummy wakeup watcher to reduce signal catching latency
		1681	# used by Impls
1402	sub _sig_add() {	1682	sub _sig_add() {
1403	unless ($SIG_COUNT++) {	1683	unless ($SIG_COUNT++) {
1404	# try to align timer on a full-second boundary, if possible	1684	# try to align timer on a full-second boundary, if possible
1405	my $NOW = AE::now;	1685	my $NOW = AE::now;
1406		1686
…		…
1416	undef $SIG_TW	1696	undef $SIG_TW
1417	unless --$SIG_COUNT;	1697	unless --$SIG_COUNT;
1418	}	1698	}
1419		1699
1420	our $_sig_name_init; $_sig_name_init = sub {	1700	our $_sig_name_init; $_sig_name_init = sub {
1421	eval q{ # poor man's autoloading	1701	eval q{ # poor man's autoloading {}
1422	undef $_sig_name_init;	1702	undef $_sig_name_init;
1423		1703
1424	if (_have_async_interrupt) {	1704	if (_have_async_interrupt) {
1425	*sig2num = \&Async::Interrupt::sig2num;	1705	*sig2num = \&Async::Interrupt::sig2num;
1426	*sig2name = \&Async::Interrupt::sig2name;	1706	*sig2name = \&Async::Interrupt::sig2name;
…		…
1450		1730
1451	sub signal {	1731	sub signal {
1452	eval q{ # poor man's autoloading {}	1732	eval q{ # poor man's autoloading {}
1453	# probe for availability of Async::Interrupt	1733	# probe for availability of Async::Interrupt
1454	if (_have_async_interrupt) {	1734	if (_have_async_interrupt) {
1455	warn "AnyEvent: using Async::Interrupt for race-free signal handling.\n" if $VERBOSE >= 8;	1735	AnyEvent::log 8 => "Using Async::Interrupt for race-free signal handling.";
1456		1736
1457	$SIGPIPE_R = new Async::Interrupt::EventPipe;	1737	$SIGPIPE_R = new Async::Interrupt::EventPipe;
1458	$SIG_IO = AE::io $SIGPIPE_R->fileno, 0, \&_signal_exec;	1738	$SIG_IO = AE::io $SIGPIPE_R->fileno, 0, \&_signal_exec;
1459		1739
1460	} else {	1740	} else {
1461	warn "AnyEvent: using emulated perl signal handling with latency timer.\n" if $VERBOSE >= 8;	1741	AnyEvent::log 8 => "Using emulated perl signal handling with latency timer.";
1462
1463	require Fcntl;
1464		1742
1465	if (AnyEvent::WIN32) {	1743	if (AnyEvent::WIN32) {
1466	require AnyEvent::Util;	1744	require AnyEvent::Util;
1467		1745
1468	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();	1746	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
1469	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R, 1) if $SIGPIPE_R;	1747	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R, 1) if $SIGPIPE_R;
1470	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W, 1) if $SIGPIPE_W; # just in case	1748	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W, 1) if $SIGPIPE_W; # just in case
1471	} else {	1749	} else {
1472	pipe $SIGPIPE_R, $SIGPIPE_W;	1750	pipe $SIGPIPE_R, $SIGPIPE_W;
1473	fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R;	1751	fcntl $SIGPIPE_R, AnyEvent::F_SETFL, AnyEvent::O_NONBLOCK if $SIGPIPE_R;
1474	fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case	1752	fcntl $SIGPIPE_W, AnyEvent::F_SETFL, AnyEvent::O_NONBLOCK if $SIGPIPE_W; # just in case
1475		1753
1476	# not strictly required, as $^F is normally 2, but let's make sure...	1754	# not strictly required, as $^F is normally 2, but let's make sure...
1477	fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;	1755	fcntl $SIGPIPE_R, AnyEvent::F_SETFD, AnyEvent::FD_CLOEXEC;
1478	fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;	1756	fcntl $SIGPIPE_W, AnyEvent::F_SETFD, AnyEvent::FD_CLOEXEC;
1479	}	1757	}
1480		1758
1481	$SIGPIPE_R	1759	$SIGPIPE_R
1482	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";	1760	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";
1483		1761
1484	$SIG_IO = AE::io $SIGPIPE_R, 0, \&_signal_exec;	1762	$SIG_IO = AE::io $SIGPIPE_R, 0, \&_signal_exec;
1485	}	1763	}
1486		1764
1487	*signal = sub {	1765	*signal = $HAVE_ASYNC_INTERRUPT
		1766	? sub {
1488	my (undef, %arg) = @_;	1767	my (undef, %arg) = @_;
1489		1768
1490	my $signal = uc $arg{signal}
1491	or Carp::croak "required option 'signal' is missing";
1492
1493	if ($HAVE_ASYNC_INTERRUPT) {
1494	# async::interrupt	1769	# async::interrupt
1495
1496	$signal = sig2num $signal;	1770	my $signal = sig2num $arg{signal};
1497	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};	1771	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
1498		1772
1499	$SIG_ASY{$signal} ||= new Async::Interrupt	1773	$SIG_ASY{$signal} ||= new Async::Interrupt
1500	cb => sub { undef $SIG_EV{$signal} },	1774	cb => sub { undef $SIG_EV{$signal} },
1501	signal => $signal,	1775	signal => $signal,
1502	pipe => [$SIGPIPE_R->filenos],	1776	pipe => [$SIGPIPE_R->filenos],
1503	pipe_autodrain => 0,	1777	pipe_autodrain => 0,
1504	;	1778	;
1505		1779
1506	} else {	1780	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
		1781	}
		1782	: sub {
		1783	my (undef, %arg) = @_;
		1784
1507	# pure perl	1785	# pure perl
1508
1509	# AE::Util has been loaded in signal
1510	$signal = sig2name $signal;	1786	my $signal = sig2name $arg{signal};
1511	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};	1787	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
1512		1788
1513	$SIG{$signal} ||= sub {	1789	$SIG{$signal} ||= sub {
1514	local $!;	1790	local $!;
1515	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;	1791	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;
1516	undef $SIG_EV{$signal};	1792	undef $SIG_EV{$signal};
1517	};	1793	};
1518		1794
1519	# can't do signal processing without introducing races in pure perl,	1795	# can't do signal processing without introducing races in pure perl,
1520	# so limit the signal latency.	1796	# so limit the signal latency.
1521	_sig_add;	1797	_sig_add;
1522	}
1523		1798
1524	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"	1799	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
		1800	}
1525	};	1801	;
1526		1802
1527	*AnyEvent::Base::signal::DESTROY = sub {	1803	*AnyEvent::Base::signal::DESTROY = sub {
1528	my ($signal, $cb) = @{$_[0]};	1804	my ($signal, $cb) = @{$_[0]};
1529		1805
1530	_sig_del;	1806	_sig_del;
…		…
1537	# print weird messages, or just unconditionally exit	1813	# print weird messages, or just unconditionally exit
1538	# instead of getting the default action.	1814	# instead of getting the default action.
1539	undef $SIG{$signal}	1815	undef $SIG{$signal}
1540	unless keys %{ $SIG_CB{$signal} };	1816	unless keys %{ $SIG_CB{$signal} };
1541	};	1817	};
		1818
		1819	*_signal_exec = sub {
		1820	$HAVE_ASYNC_INTERRUPT
		1821	? $SIGPIPE_R->drain
		1822	: sysread $SIGPIPE_R, (my $dummy), 9;
		1823
		1824	while (%SIG_EV) {
		1825	for (keys %SIG_EV) {
		1826	delete $SIG_EV{$_};
		1827	&$_ for values %{ $SIG_CB{$_} || {} };
		1828	}
		1829	}
		1830	};
1542	};	1831	};
1543	die if $@;	1832	die if $@;
		1833
1544	&signal	1834	&signal
1545	}	1835	}
1546		1836
1547	# default implementation for ->child	1837	# default implementation for ->child
1548		1838
1549	our %PID_CB;	1839	our %PID_CB;
1550	our $CHLD_W;	1840	our $CHLD_W;
1551	our $CHLD_DELAY_W;	1841	our $CHLD_DELAY_W;
1552	our $WNOHANG;
1553		1842
		1843	# used by many Impl's
1554	sub _emit_childstatus($$) {	1844	sub _emit_childstatus($$) {
1555	my (undef, $rpid, $rstatus) = @_;	1845	my (undef, $rpid, $rstatus) = @_;
1556		1846
1557	$_->($rpid, $rstatus)	1847	$_->($rpid, $rstatus)
1558	for values %{ $PID_CB{$rpid} || {} },	1848	for values %{ $PID_CB{$rpid} || {} },
1559	values %{ $PID_CB{0} || {} };	1849	values %{ $PID_CB{0} || {} };
1560	}	1850	}
1561		1851
1562	sub _sigchld {
1563	my $pid;
1564
1565	AnyEvent->_emit_childstatus ($pid, $?)
1566	while ($pid = waitpid -1, $WNOHANG) > 0;
1567	}
1568
1569	sub child {	1852	sub child {
		1853	eval q{ # poor man's autoloading {}
		1854	*_sigchld = sub {
		1855	my $pid;
		1856
		1857	AnyEvent->_emit_childstatus ($pid, $?)
		1858	while ($pid = waitpid -1, WNOHANG) > 0;
		1859	};
		1860
		1861	*child = sub {
1570	my (undef, %arg) = @_;	1862	my (undef, %arg) = @_;
1571		1863
1572	defined (my $pid = $arg{pid} + 0)	1864	my $pid = $arg{pid};
1573	or Carp::croak "required option 'pid' is missing";	1865	my $cb = $arg{cb};
1574		1866
1575	$PID_CB{$pid}{$arg{cb}} = $arg{cb};	1867	$PID_CB{$pid}{$cb+0} = $cb;
1576		1868
1577	# WNOHANG is almost cetrainly 1 everywhere
1578	$WNOHANG ||= $^O =~ /^(?:openbsd|netbsd|linux|freebsd|cygwin|MSWin32)$/
1579	? 1
1580	: eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1;
1581
1582	unless ($CHLD_W) {	1869	unless ($CHLD_W) {
1583	$CHLD_W = AE::signal CHLD => \&_sigchld;	1870	$CHLD_W = AE::signal CHLD => \&_sigchld;
1584	# child could be a zombie already, so make at least one round	1871	# child could be a zombie already, so make at least one round
1585	&_sigchld;	1872	&_sigchld;
1586	}	1873	}
1587		1874
1588	bless [$pid, $arg{cb}], "AnyEvent::Base::child"	1875	bless [$pid, $cb+0], "AnyEvent::Base::child"
1589	}	1876	};
1590		1877
1591	sub AnyEvent::Base::child::DESTROY {	1878	*AnyEvent::Base::child::DESTROY = sub {
1592	my ($pid, $cb) = @{$_[0]};	1879	my ($pid, $icb) = @{$_[0]};
1593		1880
1594	delete $PID_CB{$pid}{$cb};	1881	delete $PID_CB{$pid}{$icb};
1595	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };	1882	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };
1596		1883
1597	undef $CHLD_W unless keys %PID_CB;	1884	undef $CHLD_W unless keys %PID_CB;
		1885	};
		1886	};
		1887	die if $@;
		1888
		1889	&child
1598	}	1890	}
1599		1891
1600	# idle emulation is done by simply using a timer, regardless	1892	# idle emulation is done by simply using a timer, regardless
1601	# of whether the process is idle or not, and not letting	1893	# of whether the process is idle or not, and not letting
1602	# the callback use more than 50% of the time.	1894	# the callback use more than 50% of the time.
1603	sub idle {	1895	sub idle {
		1896	eval q{ # poor man's autoloading {}
		1897	*idle = sub {
1604	my (undef, %arg) = @_;	1898	my (undef, %arg) = @_;
1605		1899
1606	my ($cb, $w, $rcb) = $arg{cb};	1900	my ($cb, $w, $rcb) = $arg{cb};
1607		1901
1608	$rcb = sub {	1902	$rcb = sub {
1609	if ($cb) {	1903	if ($cb) {
1610	$w = _time;	1904	$w = AE::time;
1611	&$cb;	1905	&$cb;
1612	$w = _time - $w;	1906	$w = AE::time - $w;
1613		1907
1614	# never use more then 50% of the time for the idle watcher,	1908	# never use more then 50% of the time for the idle watcher,
1615	# within some limits	1909	# within some limits
1616	$w = 0.0001 if $w < 0.0001;	1910	$w = 0.0001 if $w < 0.0001;
1617	$w = 5 if $w > 5;	1911	$w = 5 if $w > 5;
1618		1912
1619	$w = AE::timer $w, 0, $rcb;	1913	$w = AE::timer $w, 0, $rcb;
1620	} else {	1914	} else {
1621	# clean up...	1915	# clean up...
1622	undef $w;	1916	undef $w;
1623	undef $rcb;	1917	undef $rcb;
		1918	}
		1919	};
		1920
		1921	$w = AE::timer 0.05, 0, $rcb;
		1922
		1923	bless \\$cb, "AnyEvent::Base::idle"
1624	}	1924	};
		1925
		1926	*AnyEvent::Base::idle::DESTROY = sub {
		1927	undef $${$_[0]};
		1928	};
1625	};	1929	};
		1930	die if $@;
1626		1931
1627	$w = AE::timer 0.05, 0, $rcb;	1932	&idle
1628
1629	bless \\$cb, "AnyEvent::Base::idle"
1630	}
1631
1632	sub AnyEvent::Base::idle::DESTROY {
1633	undef $${$_[0]};
1634	}	1933	}
1635		1934
1636	package AnyEvent::CondVar;	1935	package AnyEvent::CondVar;
1637		1936
1638	our @ISA = AnyEvent::CondVar::Base::;	1937	our @ISA = AnyEvent::CondVar::Base::;
		1938
		1939	# only to be used for subclassing
		1940	sub new {
		1941	my $class = shift;
		1942	bless AnyEvent->condvar (@_), $class
		1943	}
1639		1944
1640	package AnyEvent::CondVar::Base;	1945	package AnyEvent::CondVar::Base;
1641		1946
1642	#use overload	1947	#use overload
1643	# '&{}' => sub { my $self = shift; sub { $self->send (@_) } },	1948	# '&{}' => sub { my $self = shift; sub { $self->send (@_) } },
…		…
1653		1958
1654	sub _send {	1959	sub _send {
1655	# nop	1960	# nop
1656	}	1961	}
1657		1962
		1963	sub _wait {
		1964	AnyEvent->_poll until $_[0]{_ae_sent};
		1965	}
		1966
1658	sub send {	1967	sub send {
1659	my $cv = shift;	1968	my $cv = shift;
1660	$cv->{_ae_sent} = [@_];	1969	$cv->{_ae_sent} = [@_];
1661	(delete $cv->{_ae_cb})->($cv) if $cv->{_ae_cb};	1970	(delete $cv->{_ae_cb})->($cv) if $cv->{_ae_cb};
1662	$cv->_send;	1971	$cv->_send;
…		…
1669		1978
1670	sub ready {	1979	sub ready {
1671	$_[0]{_ae_sent}	1980	$_[0]{_ae_sent}
1672	}	1981	}
1673		1982
1674	sub _wait {
1675	$WAITING
1676	and !$_[0]{_ae_sent}
1677	and Carp::croak "AnyEvent::CondVar: recursive blocking wait detected";
1678
1679	local $WAITING = 1;
1680	AnyEvent->one_event while !$_[0]{_ae_sent};
1681	}
1682
1683	sub recv {	1983	sub recv {
		1984	unless ($_[0]{_ae_sent}) {
		1985	$WAITING
		1986	and Carp::croak "AnyEvent::CondVar: recursive blocking wait attempted";
		1987
		1988	local $WAITING = 1;
1684	$_[0]->_wait;	1989	$_[0]->_wait;
		1990	}
1685		1991
1686	Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak};	1992	$_[0]{_ae_croak}
1687	wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0]	1993	and Carp::croak $_[0]{_ae_croak};
		1994
		1995	wantarray
		1996	? @{ $_[0]{_ae_sent} }
		1997	: $_[0]{_ae_sent}[0]
1688	}	1998	}
1689		1999
1690	sub cb {	2000	sub cb {
1691	my $cv = shift;	2001	my $cv = shift;
1692		2002
…		…
1708	&{ $_[0]{_ae_end_cb} || sub { $_[0]->send } };	2018	&{ $_[0]{_ae_end_cb} || sub { $_[0]->send } };
1709	}	2019	}
1710		2020
1711	# undocumented/compatibility with pre-3.4	2021	# undocumented/compatibility with pre-3.4
1712	*broadcast = \&send;	2022	*broadcast = \&send;
1713	*wait = \&_wait;	2023	*wait = \&recv;
1714		2024
1715	=head1 ERROR AND EXCEPTION HANDLING	2025	=head1 ERROR AND EXCEPTION HANDLING
1716		2026
1717	In general, AnyEvent does not do any error handling - it relies on the	2027	In general, AnyEvent does not do any error handling - it relies on the
1718	caller to do that if required. The L<AnyEvent::Strict> module (see also	2028	caller to do that if required. The L<AnyEvent::Strict> module (see also
…		…
1730	$Event/EV::DIED->() >>, L<Glib> uses C<< install_exception_handler >> and	2040	$Event/EV::DIED->() >>, L<Glib> uses C<< install_exception_handler >> and
1731	so on.	2041	so on.
1732		2042
1733	=head1 ENVIRONMENT VARIABLES	2043	=head1 ENVIRONMENT VARIABLES
1734		2044
1735	The following environment variables are used by this module or its	2045	AnyEvent supports a number of environment variables that tune the
1736	submodules.	2046	runtime behaviour. They are usually evaluated when AnyEvent is
		2047	loaded, initialised, or a submodule that uses them is loaded. Many of
		2048	them also cause AnyEvent to load additional modules - for example,
		2049	C<PERL_ANYEVENT_DEBUG_WRAP> causes the L<AnyEvent::Debug> module to be
		2050	loaded.
1737		2051
1738	Note that AnyEvent will remove I<all> environment variables starting with	2052	All the environment variables documented here start with
1739	C<PERL_ANYEVENT_> from C<%ENV> when it is loaded while taint mode is	2053	C<PERL_ANYEVENT_>, which is what AnyEvent considers its own
1740	enabled.	2054	namespace. Other modules are encouraged (but by no means required) to use
		2055	C<PERL_ANYEVENT_SUBMODULE> if they have registered the AnyEvent::Submodule
		2056	namespace on CPAN, for any submodule. For example, L<AnyEvent::HTTP> could
		2057	be expected to use C<PERL_ANYEVENT_HTTP_PROXY> (it should not access env
		2058	variables starting with C<AE_>, see below).
		2059
		2060	All variables can also be set via the C<AE_> prefix, that is, instead
		2061	of setting C<PERL_ANYEVENT_VERBOSE> you can also set C<AE_VERBOSE>. In
		2062	case there is a clash btween anyevent and another program that uses
		2063	C<AE_something> you can set the corresponding C<PERL_ANYEVENT_something>
		2064	variable to the empty string, as those variables take precedence.
		2065
		2066	When AnyEvent is first loaded, it copies all C<AE_xxx> env variables
		2067	to their C<PERL_ANYEVENT_xxx> counterpart unless that variable already
		2068	exists. If taint mode is on, then AnyEvent will remove I<all> environment
		2069	variables starting with C<PERL_ANYEVENT_> from C<%ENV> (or replace them
		2070	with C<undef> or the empty string, if the corresaponding C<AE_> variable
		2071	is set).
		2072
		2073	The exact algorithm is currently:
		2074
		2075	1. if taint mode enabled, delete all PERL_ANYEVENT_xyz variables from %ENV
		2076	2. copy over AE_xyz to PERL_ANYEVENT_xyz unless the latter alraedy exists
		2077	3. if taint mode enabled, set all PERL_ANYEVENT_xyz variables to undef.
		2078
		2079	This ensures that child processes will not see the C<AE_> variables.
		2080
		2081	The following environment variables are currently known to AnyEvent:
1741		2082
1742	=over 4	2083	=over 4
1743		2084
1744	=item C<PERL_ANYEVENT_VERBOSE>	2085	=item C<PERL_ANYEVENT_VERBOSE>
1745		2086
1746	By default, AnyEvent will be completely silent except in fatal	2087	By default, AnyEvent will log messages with loglevel C<4> (C<error>) or
1747	conditions. You can set this environment variable to make AnyEvent more	2088	higher (see L<AnyEvent::Log>). You can set this environment variable to a
1748	talkative.	2089	numerical loglevel to make AnyEvent more (or less) talkative.
1749		2090
		2091	If you want to do more than just set the global logging level
		2092	you should have a look at C<PERL_ANYEVENT_LOG>, which allows much more
		2093	complex specifications.
		2094
		2095	When set to C<0> (C<off>), then no messages whatsoever will be logged with
		2096	everything else at defaults.
		2097
1750	When set to C<1> or higher, causes AnyEvent to warn about unexpected	2098	When set to C<5> or higher (C<warn>), AnyEvent warns about unexpected
1751	conditions, such as not being able to load the event model specified by	2099	conditions, such as not being able to load the event model specified by
1752	C<PERL_ANYEVENT_MODEL>.	2100	C<PERL_ANYEVENT_MODEL>, or a guard callback throwing an exception - this
		2101	is the minimum recommended level for use during development.
1753		2102
1754	When set to C<2> or higher, cause AnyEvent to report to STDERR which event	2103	When set to C<7> or higher (info), AnyEvent reports which event model it
1755	model it chooses.	2104	chooses.
1756		2105
1757	When set to C<8> or higher, then AnyEvent will report extra information on	2106	When set to C<8> or higher (debug), then AnyEvent will report extra
1758	which optional modules it loads and how it implements certain features.	2107	information on which optional modules it loads and how it implements
		2108	certain features.
		2109
		2110	=item C<PERL_ANYEVENT_LOG>
		2111
		2112	Accepts rather complex logging specifications. For example, you could log
		2113	all C<debug> messages of some module to stderr, warnings and above to
		2114	stderr, and errors and above to syslog, with:
		2115
		2116	PERL_ANYEVENT_LOG=Some::Module=debug,+log:filter=warn,+%syslog:%syslog=error,syslog
		2117
		2118	For the rather extensive details, see L<AnyEvent::Log>.
		2119
		2120	This variable is evaluated when AnyEvent (or L<AnyEvent::Log>) is loaded,
		2121	so will take effect even before AnyEvent has initialised itself.
		2122
		2123	Note that specifying this environment variable causes the L<AnyEvent::Log>
		2124	module to be loaded, while C<PERL_ANYEVENT_VERBOSE> does not, so only
		2125	using the latter saves a few hundred kB of memory unless a module
		2126	explicitly needs the extra features of AnyEvent::Log.
1759		2127
1760	=item C<PERL_ANYEVENT_STRICT>	2128	=item C<PERL_ANYEVENT_STRICT>
1761		2129
1762	AnyEvent does not do much argument checking by default, as thorough	2130	AnyEvent does not do much argument checking by default, as thorough
1763	argument checking is very costly. Setting this variable to a true value	2131	argument checking is very costly. Setting this variable to a true value
…		…
1765	check the arguments passed to most method calls. If it finds any problems,	2133	check the arguments passed to most method calls. If it finds any problems,
1766	it will croak.	2134	it will croak.
1767		2135
1768	In other words, enables "strict" mode.	2136	In other words, enables "strict" mode.
1769		2137
1770	Unlike C<use strict> (or it's modern cousin, C<< use L<common::sense>	2138	Unlike C<use strict> (or its modern cousin, C<< use L<common::sense>
1771	>>, it is definitely recommended to keep it off in production. Keeping	2139	>>, it is definitely recommended to keep it off in production. Keeping
1772	C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs	2140	C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs
1773	can be very useful, however.	2141	can be very useful, however.
1774		2142
		2143	=item C<PERL_ANYEVENT_DEBUG_SHELL>
		2144
		2145	If this env variable is nonempty, then its contents will be interpreted by
		2146	C<AnyEvent::Socket::parse_hostport> and C<AnyEvent::Debug::shell> (after
		2147	replacing every occurance of C<$$> by the process pid). The shell object
		2148	is saved in C<$AnyEvent::Debug::SHELL>.
		2149
		2150	This happens when the first watcher is created.
		2151
		2152	For example, to bind a debug shell on a unix domain socket in
		2153	F<< /tmp/debug<pid>.sock >>, you could use this:
		2154
		2155	PERL_ANYEVENT_DEBUG_SHELL=/tmp/debug\$\$.sock perlprog
		2156	# connect with e.g.: socat readline /tmp/debug123.sock
		2157
		2158	Or to bind to tcp port 4545 on localhost:
		2159
		2160	PERL_ANYEVENT_DEBUG_SHELL=127.0.0.1:4545 perlprog
		2161	# connect with e.g.: telnet localhost 4545
		2162
		2163	Note that creating sockets in F</tmp> or on localhost is very unsafe on
		2164	multiuser systems.
		2165
		2166	=item C<PERL_ANYEVENT_DEBUG_WRAP>
		2167
		2168	Can be set to C<0>, C<1> or C<2> and enables wrapping of all watchers for
		2169	debugging purposes. See C<AnyEvent::Debug::wrap> for details.
		2170
1775	=item C<PERL_ANYEVENT_MODEL>	2171	=item C<PERL_ANYEVENT_MODEL>
1776		2172
1777	This can be used to specify the event model to be used by AnyEvent, before	2173	This can be used to specify the event model to be used by AnyEvent, before
1778	auto detection and -probing kicks in. It must be a string consisting	2174	auto detection and -probing kicks in.
1779	entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended	2175
		2176	It normally is a string consisting entirely of ASCII letters (e.g. C<EV>
		2177	or C<IOAsync>). The string C<AnyEvent::Impl::> gets prepended and the
1780	and the resulting module name is loaded and if the load was successful,	2178	resulting module name is loaded and - if the load was successful - used as
1781	used as event model. If it fails to load AnyEvent will proceed with	2179	event model backend. If it fails to load then AnyEvent will proceed with
1782	auto detection and -probing.	2180	auto detection and -probing.
1783		2181
1784	This functionality might change in future versions.	2182	If the string ends with C<::> instead (e.g. C<AnyEvent::Impl::EV::>) then
		2183	nothing gets prepended and the module name is used as-is (hint: C<::> at
		2184	the end of a string designates a module name and quotes it appropriately).
1785		2185
1786	For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you	2186	For example, to force the pure perl model (L<AnyEvent::Loop::Perl>) you
1787	could start your program like this:	2187	could start your program like this:
1788		2188
1789	PERL_ANYEVENT_MODEL=Perl perl ...	2189	PERL_ANYEVENT_MODEL=Perl perl ...
		2190
		2191	=item C<PERL_ANYEVENT_IO_MODEL>
		2192
		2193	The current file I/O model - see L<AnyEvent::IO> for more info.
		2194
		2195	At the moment, only C<Perl> (small, pure-perl, synchronous) and
		2196	C<IOAIO> (truly asynchronous) are supported. The default is C<IOAIO> if
		2197	L<AnyEvent::AIO> can be loaded, otherwise it is C<Perl>.
1790		2198
1791	=item C<PERL_ANYEVENT_PROTOCOLS>	2199	=item C<PERL_ANYEVENT_PROTOCOLS>
1792		2200
1793	Used by both L<AnyEvent::DNS> and L<AnyEvent::Socket> to determine preferences	2201	Used by both L<AnyEvent::DNS> and L<AnyEvent::Socket> to determine preferences
1794	for IPv4 or IPv6. The default is unspecified (and might change, or be the result	2202	for IPv4 or IPv6. The default is unspecified (and might change, or be the result
…		…
1807	but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4>	2215	but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4>
1808	- only support IPv4, never try to resolve or contact IPv6	2216	- only support IPv4, never try to resolve or contact IPv6
1809	addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or	2217	addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or
1810	IPv6, but prefer IPv6 over IPv4.	2218	IPv6, but prefer IPv6 over IPv4.
1811		2219
		2220	=item C<PERL_ANYEVENT_HOSTS>
		2221
		2222	This variable, if specified, overrides the F</etc/hosts> file used by
		2223	L<AnyEvent::Socket>C<::resolve_sockaddr>, i.e. hosts aliases will be read
		2224	from that file instead.
		2225
1812	=item C<PERL_ANYEVENT_EDNS0>	2226	=item C<PERL_ANYEVENT_EDNS0>
1813		2227
1814	Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension	2228	Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension for
1815	for DNS. This extension is generally useful to reduce DNS traffic, but	2229	DNS. This extension is generally useful to reduce DNS traffic, especially
1816	some (broken) firewalls drop such DNS packets, which is why it is off by	2230	when DNSSEC is involved, but some (broken) firewalls drop such DNS
1817	default.	2231	packets, which is why it is off by default.
1818		2232
1819	Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce	2233	Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce
1820	EDNS0 in its DNS requests.	2234	EDNS0 in its DNS requests.
1821		2235
1822	=item C<PERL_ANYEVENT_MAX_FORKS>	2236	=item C<PERL_ANYEVENT_MAX_FORKS>
…		…
1828		2242
1829	The default value for the C<max_outstanding> parameter for the default DNS	2243	The default value for the C<max_outstanding> parameter for the default DNS
1830	resolver - this is the maximum number of parallel DNS requests that are	2244	resolver - this is the maximum number of parallel DNS requests that are
1831	sent to the DNS server.	2245	sent to the DNS server.
1832		2246
		2247	=item C<PERL_ANYEVENT_MAX_SIGNAL_LATENCY>
		2248
		2249	Perl has inherently racy signal handling (you can basically choose between
		2250	losing signals and memory corruption) - pure perl event loops (including
		2251	C<AnyEvent::Loop>, when C<Async::Interrupt> isn't available) therefore
		2252	have to poll regularly to avoid losing signals.
		2253
		2254	Some event loops are racy, but don't poll regularly, and some event loops
		2255	are written in C but are still racy. For those event loops, AnyEvent
		2256	installs a timer that regularly wakes up the event loop.
		2257
		2258	By default, the interval for this timer is C<10> seconds, but you can
		2259	override this delay with this environment variable (or by setting
		2260	the C<$AnyEvent::MAX_SIGNAL_LATENCY> variable before creating signal
		2261	watchers).
		2262
		2263	Lower values increase CPU (and energy) usage, higher values can introduce
		2264	long delays when reaping children or waiting for signals.
		2265
		2266	The L<AnyEvent::Async> module, if available, will be used to avoid this
		2267	polling (with most event loops).
		2268
1833	=item C<PERL_ANYEVENT_RESOLV_CONF>	2269	=item C<PERL_ANYEVENT_RESOLV_CONF>
1834		2270
1835	The file to use instead of F</etc/resolv.conf> (or OS-specific	2271	The absolute path to a F<resolv.conf>-style file to use instead of
1836	configuration) in the default resolver. When set to the empty string, no	2272	F</etc/resolv.conf> (or the OS-specific configuration) in the default
1837	default config will be used.	2273	resolver, or the empty string to select the default configuration.
1838		2274
1839	=item C<PERL_ANYEVENT_CA_FILE>, C<PERL_ANYEVENT_CA_PATH>.	2275	=item C<PERL_ANYEVENT_CA_FILE>, C<PERL_ANYEVENT_CA_PATH>.
1840		2276
1841	When neither C<ca_file> nor C<ca_path> was specified during	2277	When neither C<ca_file> nor C<ca_path> was specified during
1842	L<AnyEvent::TLS> context creation, and either of these environment	2278	L<AnyEvent::TLS> context creation, and either of these environment
1843	variables exist, they will be used to specify CA certificate locations	2279	variables are nonempty, they will be used to specify CA certificate
1844	instead of a system-dependent default.	2280	locations instead of a system-dependent default.
1845		2281
1846	=item C<PERL_ANYEVENT_AVOID_GUARD> and C<PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT>	2282	=item C<PERL_ANYEVENT_AVOID_GUARD> and C<PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT>
1847		2283
1848	When these are set to C<1>, then the respective modules are not	2284	When these are set to C<1>, then the respective modules are not
1849	loaded. Mostly good for testing AnyEvent itself.	2285	loaded. Mostly good for testing AnyEvent itself.
…		…
1997		2433
1998	The actual code goes further and collects all errors (C<die>s, exceptions)	2434	The actual code goes further and collects all errors (C<die>s, exceptions)
1999	that occurred during request processing. The C<result> method detects	2435	that occurred during request processing. The C<result> method detects
2000	whether an exception as thrown (it is stored inside the $txn object)	2436	whether an exception as thrown (it is stored inside the $txn object)
2001	and just throws the exception, which means connection errors and other	2437	and just throws the exception, which means connection errors and other
2002	problems get reported tot he code that tries to use the result, not in a	2438	problems get reported to the code that tries to use the result, not in a
2003	random callback.	2439	random callback.
2004		2440
2005	All of this enables the following usage styles:	2441	All of this enables the following usage styles:
2006		2442
2007	1. Blocking:	2443	1. Blocking:
…		…
2181	(even when used without AnyEvent), but most event loops have acceptable	2617	(even when used without AnyEvent), but most event loops have acceptable
2182	performance with or without AnyEvent.	2618	performance with or without AnyEvent.
2183		2619
2184	=item * The overhead AnyEvent adds is usually much smaller than the overhead of	2620	=item * The overhead AnyEvent adds is usually much smaller than the overhead of
2185	the actual event loop, only with extremely fast event loops such as EV	2621	the actual event loop, only with extremely fast event loops such as EV
2186	adds AnyEvent significant overhead.	2622	does AnyEvent add significant overhead.
2187		2623
2188	=item * You should avoid POE like the plague if you want performance or	2624	=item * You should avoid POE like the plague if you want performance or
2189	reasonable memory usage.	2625	reasonable memory usage.
2190		2626
2191	=back	2627	=back
…		…
2421	unless defined $SIG{PIPE};	2857	unless defined $SIG{PIPE};
2422		2858
2423	=head1 RECOMMENDED/OPTIONAL MODULES	2859	=head1 RECOMMENDED/OPTIONAL MODULES
2424		2860
2425	One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and	2861	One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and
2426	it's built-in modules) are required to use it.	2862	its built-in modules) are required to use it.
2427		2863
2428	That does not mean that AnyEvent won't take advantage of some additional	2864	That does not mean that AnyEvent won't take advantage of some additional
2429	modules if they are installed.	2865	modules if they are installed.
2430		2866
2431	This section epxlains which additional modules will be used, and how they	2867	This section explains which additional modules will be used, and how they
2432	affect AnyEvent's operetion.	2868	affect AnyEvent's operation.
2433		2869
2434	=over 4	2870	=over 4
2435		2871
2436	=item L<Async::Interrupt>	2872	=item L<Async::Interrupt>
2437		2873
…		…
2442	catch the signals) with some delay (default is 10 seconds, look for	2878	catch the signals) with some delay (default is 10 seconds, look for
2443	C<$AnyEvent::MAX_SIGNAL_LATENCY>).	2879	C<$AnyEvent::MAX_SIGNAL_LATENCY>).
2444		2880
2445	If this module is available, then it will be used to implement signal	2881	If this module is available, then it will be used to implement signal
2446	catching, which means that signals will not be delayed, and the event loop	2882	catching, which means that signals will not be delayed, and the event loop
2447	will not be interrupted regularly, which is more efficient (And good for	2883	will not be interrupted regularly, which is more efficient (and good for
2448	battery life on laptops).	2884	battery life on laptops).
2449		2885
2450	This affects not just the pure-perl event loop, but also other event loops	2886	This affects not just the pure-perl event loop, but also other event loops
2451	that have no signal handling on their own (e.g. Glib, Tk, Qt).	2887	that have no signal handling on their own (e.g. Glib, Tk, Qt).
2452		2888
…		…
2464	automatic timer adjustments even when no monotonic clock is available,	2900	automatic timer adjustments even when no monotonic clock is available,
2465	can take avdantage of advanced kernel interfaces such as C<epoll> and	2901	can take avdantage of advanced kernel interfaces such as C<epoll> and
2466	C<kqueue>, and is the fastest backend I<by far>. You can even embed	2902	C<kqueue>, and is the fastest backend I<by far>. You can even embed
2467	L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>).	2903	L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>).
2468		2904
		2905	If you only use backends that rely on another event loop (e.g. C<Tk>),
		2906	then this module will do nothing for you.
		2907
2469	=item L<Guard>	2908	=item L<Guard>
2470		2909
2471	The guard module, when used, will be used to implement	2910	The guard module, when used, will be used to implement
2472	C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a	2911	C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a
2473	lot less memory), but otherwise doesn't affect guard operation much. It is	2912	lot less memory), but otherwise doesn't affect guard operation much. It is
2474	purely used for performance.	2913	purely used for performance.
2475		2914
2476	=item L<JSON> and L<JSON::XS>	2915	=item L<JSON> and L<JSON::XS>
2477		2916
2478	One of these modules is required when you want to read or write JSON data	2917	One of these modules is required when you want to read or write JSON data
2479	via L<AnyEvent::Handle>. It is also written in pure-perl, but can take	2918	via L<AnyEvent::Handle>. L<JSON> is also written in pure-perl, but can take
2480	advantage of the ultra-high-speed L<JSON::XS> module when it is installed.	2919	advantage of the ultra-high-speed L<JSON::XS> module when it is installed.
2481
2482	In fact, L<AnyEvent::Handle> will use L<JSON::XS> by default if it is
2483	installed.
2484		2920
2485	=item L<Net::SSLeay>	2921	=item L<Net::SSLeay>
2486		2922
2487	Implementing TLS/SSL in Perl is certainly interesting, but not very	2923	Implementing TLS/SSL in Perl is certainly interesting, but not very
2488	worthwhile: If this module is installed, then L<AnyEvent::Handle> (with	2924	worthwhile: If this module is installed, then L<AnyEvent::Handle> (with
2489	the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL.	2925	the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL.
2490		2926
2491	=item L<Time::HiRes>	2927	=item L<Time::HiRes>
2492		2928
2493	This module is part of perl since release 5.008. It will be used when the	2929	This module is part of perl since release 5.008. It will be used when the
2494	chosen event library does not come with a timing source on it's own. The	2930	chosen event library does not come with a timing source of its own. The
2495	pure-perl event loop (L<AnyEvent::Impl::Perl>) will additionally use it to	2931	pure-perl event loop (L<AnyEvent::Loop>) will additionally load it to
2496	try to use a monotonic clock for timing stability.	2932	try to use a monotonic clock for timing stability.
2497		2933
2498	=back	2934	=back
2499		2935
2500		2936
2501	=head1 FORK	2937	=head1 FORK
2502		2938
2503	Most event libraries are not fork-safe. The ones who are usually are	2939	Most event libraries are not fork-safe. The ones who are usually are
2504	because they rely on inefficient but fork-safe C<select> or C<poll>	2940	because they rely on inefficient but fork-safe C<select> or C<poll> calls
2505	calls. Only L<EV> is fully fork-aware.	2941	- higher performance APIs such as BSD's kqueue or the dreaded Linux epoll
		2942	are usually badly thought-out hacks that are incompatible with fork in
		2943	one way or another. Only L<EV> is fully fork-aware and ensures that you
		2944	continue event-processing in both parent and child (or both, if you know
		2945	what you are doing).
		2946
		2947	This means that, in general, you cannot fork and do event processing in
		2948	the child if the event library was initialised before the fork (which
		2949	usually happens when the first AnyEvent watcher is created, or the library
		2950	is loaded).
2506		2951
2507	If you have to fork, you must either do so I<before> creating your first	2952	If you have to fork, you must either do so I<before> creating your first
2508	watcher OR you must not use AnyEvent at all in the child OR you must do	2953	watcher OR you must not use AnyEvent at all in the child OR you must do
2509	something completely out of the scope of AnyEvent.	2954	something completely out of the scope of AnyEvent.
		2955
		2956	The problem of doing event processing in the parent I<and> the child
		2957	is much more complicated: even for backends that I<are> fork-aware or
		2958	fork-safe, their behaviour is not usually what you want: fork clones all
		2959	watchers, that means all timers, I/O watchers etc. are active in both
		2960	parent and child, which is almost never what you want. USing C<exec>
		2961	to start worker children from some kind of manage rprocess is usually
		2962	preferred, because it is much easier and cleaner, at the expense of having
		2963	to have another binary.
2510		2964
2511		2965
2512	=head1 SECURITY CONSIDERATIONS	2966	=head1 SECURITY CONSIDERATIONS
2513		2967
2514	AnyEvent can be forced to load any event model via	2968	AnyEvent can be forced to load any event model via
…		…
2544	pronounced).	2998	pronounced).
2545		2999
2546		3000
2547	=head1 SEE ALSO	3001	=head1 SEE ALSO
2548		3002
2549	Utility functions: L<AnyEvent::Util>.	3003	Tutorial/Introduction: L<AnyEvent::Intro>.
2550		3004
2551	Event modules: L<EV>, L<EV::Glib>, L<Glib::EV>, L<Event>, L<Glib::Event>,	3005	FAQ: L<AnyEvent::FAQ>.
2552	L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.	3006
		3007	Utility functions: L<AnyEvent::Util> (misc. grab-bag), L<AnyEvent::Log>
		3008	(simply logging).
		3009
		3010	Development/Debugging: L<AnyEvent::Strict> (stricter checking),
		3011	L<AnyEvent::Debug> (interactive shell, watcher tracing).
		3012
		3013	Supported event modules: L<AnyEvent::Loop>, L<EV>, L<EV::Glib>,
		3014	L<Glib::EV>, L<Event>, L<Glib::Event>, L<Glib>, L<Tk>, L<Event::Lib>,
		3015	L<Qt>, L<POE>, L<FLTK>.
2553		3016
2554	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,	3017	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,
2555	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,	3018	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,
2556	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,	3019	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,
2557	L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>, L<Anyevent::Impl::Irssi>.	3020	L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>, L<Anyevent::Impl::Irssi>,
		3021	L<AnyEvent::Impl::FLTK>.
2558		3022
2559	Non-blocking file handles, sockets, TCP clients and	3023	Non-blocking handles, pipes, stream sockets, TCP clients and
2560	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.	3024	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.
2561		3025
		3026	Asynchronous File I/O: L<AnyEvent::IO>.
		3027
2562	Asynchronous DNS: L<AnyEvent::DNS>.	3028	Asynchronous DNS: L<AnyEvent::DNS>.
2563		3029
2564	Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>,	3030	Thread support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>.
2565	L<Coro::Event>,
2566		3031
2567	Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::XMPP>,	3032	Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::IRC>,
2568	L<AnyEvent::HTTP>.	3033	L<AnyEvent::HTTP>.
2569		3034
2570		3035
2571	=head1 AUTHOR	3036	=head1 AUTHOR
2572		3037
2573	Marc Lehmann <schmorp@schmorp.de>	3038	Marc Lehmann <schmorp@schmorp.de>
2574	http://home.schmorp.de/	3039	http://anyevent.schmorp.de
2575		3040
2576	=cut	3041	=cut
2577		3042
2578	1	3043	1
2579		3044

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