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Revision 1.279 by root, Sun Aug 9 16:05:11 2009 UTC vs.
Revision 1.379 by root, Fri Aug 26 18:09:04 2011 UTC

1	=head1 NAME	1	=head1 NAME
2		2
3	AnyEvent - the DBI of event loop programming	3	AnyEvent - the DBI of event loop programming
4		4
5	EV, Event, Glib, Tk, Perl, Event::Lib, Irssi, rxvt-unicode, IO::Async, Qt	5	EV, Event, Glib, Tk, Perl, Event::Lib, Irssi, rxvt-unicode, IO::Async, Qt,
6	and POE are various supported event loops/environments.	6	FLTK and POE are various supported event loops/environments.
7		7
8	=head1 SYNOPSIS	8	=head1 SYNOPSIS
9		9
10	use AnyEvent;	10	use AnyEvent;
11		11
		12	# if you prefer function calls, look at the AE manpage for
		13	# an alternative API.
		14
12	# file descriptor readable	15	# file handle or descriptor readable
13	my $w = AnyEvent->io (fh => $fh, poll => "r", cb => sub { ... });	16	my $w = AnyEvent->io (fh => $fh, poll => "r", cb => sub { ... });
14		17
15	# one-shot or repeating timers	18	# one-shot or repeating timers
16	my $w = AnyEvent->timer (after => $seconds, cb => sub { ... });	19	my $w = AnyEvent->timer (after => $seconds, cb => sub { ... });
17	my $w = AnyEvent->timer (after => $seconds, interval => $seconds, cb => ...	20	my $w = AnyEvent->timer (after => $seconds, interval => $seconds, cb => ...);
18		21
19	print AnyEvent->now; # prints current event loop time	22	print AnyEvent->now; # prints current event loop time
20	print AnyEvent->time; # think Time::HiRes::time or simply CORE::time.	23	print AnyEvent->time; # think Time::HiRes::time or simply CORE::time.
21		24
22	# POSIX signal	25	# POSIX signal
…		…
43	in a tutorial or some gentle introduction, have a look at the	46	in a tutorial or some gentle introduction, have a look at the
44	L<AnyEvent::Intro> manpage.	47	L<AnyEvent::Intro> manpage.
45		48
46	=head1 SUPPORT	49	=head1 SUPPORT
47		50
		51	An FAQ document is available as L<AnyEvent::FAQ>.
		52
48	There is a mailinglist for discussing all things AnyEvent, and an IRC	53	There also is a mailinglist for discussing all things AnyEvent, and an IRC
49	channel, too.	54	channel, too.
50		55
51	See the AnyEvent project page at the B<Schmorpforge Ta-Sa Software	56	See the AnyEvent project page at the B<Schmorpforge Ta-Sa Software
52	Repository>, at L<http://anyevent.schmorp.de>, for more info.	57	Repository>, at L<http://anyevent.schmorp.de>, for more info.
53		58
…		…
73	module users into the same thing by forcing them to use the same event	78	module users into the same thing by forcing them to use the same event
74	model you use.	79	model you use.
75		80
76	For modules like POE or IO::Async (which is a total misnomer as it is	81	For modules like POE or IO::Async (which is a total misnomer as it is
77	actually doing all I/O I<synchronously>...), using them in your module is	82	actually doing all I/O I<synchronously>...), using them in your module is
78	like joining a cult: After you joined, you are dependent on them and you	83	like joining a cult: After you join, you are dependent on them and you
79	cannot use anything else, as they are simply incompatible to everything	84	cannot use anything else, as they are simply incompatible to everything
80	that isn't them. What's worse, all the potential users of your	85	that isn't them. What's worse, all the potential users of your
81	module are I<also> forced to use the same event loop you use.	86	module are I<also> forced to use the same event loop you use.
82		87
83	AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works	88	AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works
84	fine. AnyEvent + Tk works fine etc. etc. but none of these work together	89	fine. AnyEvent + Tk works fine etc. etc. but none of these work together
85	with the rest: POE + IO::Async? No go. Tk + Event? No go. Again: if	90	with the rest: POE + EV? No go. Tk + Event? No go. Again: if your module
86	your module uses one of those, every user of your module has to use it,	91	uses one of those, every user of your module has to use it, too. But if
87	too. But if your module uses AnyEvent, it works transparently with all	92	your module uses AnyEvent, it works transparently with all event models it
88	event models it supports (including stuff like IO::Async, as long as those	93	supports (including stuff like IO::Async, as long as those use one of the
89	use one of the supported event loops. It is trivial to add new event loops	94	supported event loops. It is easy to add new event loops to AnyEvent, too,
90	to AnyEvent, too, so it is future-proof).	95	so it is future-proof).
91		96
92	In addition to being free of having to use I<the one and only true event	97	In addition to being free of having to use I<the one and only true event
93	model>, AnyEvent also is free of bloat and policy: with POE or similar	98	model>, AnyEvent also is free of bloat and policy: with POE or similar
94	modules, you get an enormous amount of code and strict rules you have to	99	modules, you get an enormous amount of code and strict rules you have to
95	follow. AnyEvent, on the other hand, is lean and up to the point, by only	100	follow. AnyEvent, on the other hand, is lean and to the point, by only
96	offering the functionality that is necessary, in as thin as a wrapper as	101	offering the functionality that is necessary, in as thin as a wrapper as
97	technically possible.	102	technically possible.
98		103
99	Of course, AnyEvent comes with a big (and fully optional!) toolbox	104	Of course, AnyEvent comes with a big (and fully optional!) toolbox
100	of useful functionality, such as an asynchronous DNS resolver, 100%	105	of useful functionality, such as an asynchronous DNS resolver, 100%
…		…
106	useful) and you want to force your users to use the one and only event	111	useful) and you want to force your users to use the one and only event
107	model, you should I<not> use this module.	112	model, you should I<not> use this module.
108		113
109	=head1 DESCRIPTION	114	=head1 DESCRIPTION
110		115
111	L<AnyEvent> provides an identical interface to multiple event loops. This	116	L<AnyEvent> provides a uniform interface to various event loops. This
112	allows module authors to utilise an event loop without forcing module	117	allows module authors to use event loop functionality without forcing
113	users to use the same event loop (as only a single event loop can coexist	118	module users to use a specific event loop implementation (since more
114	peacefully at any one time).	119	than one event loop cannot coexist peacefully).
115		120
116	The interface itself is vaguely similar, but not identical to the L<Event>	121	The interface itself is vaguely similar, but not identical to the L<Event>
117	module.	122	module.
118		123
119	During the first call of any watcher-creation method, the module tries	124	During the first call of any watcher-creation method, the module tries
120	to detect the currently loaded event loop by probing whether one of the	125	to detect the currently loaded event loop by probing whether one of the
121	following modules is already loaded: L<EV>,	126	following modules is already loaded: L<EV>, L<AnyEvent::Loop>,
122	L<Event>, L<Glib>, L<AnyEvent::Impl::Perl>, L<Tk>, L<Event::Lib>, L<Qt>,	127	L<Event>, L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>. The first one
123	L<POE>. The first one found is used. If none are found, the module tries	128	found is used. If none are detected, the module tries to load the first
124	to load these modules (excluding Tk, Event::Lib, Qt and POE as the pure perl	129	four modules in the order given; but note that if L<EV> is not
125	adaptor should always succeed) in the order given. The first one that can	130	available, the pure-perl L<AnyEvent::Loop> should always work, so
126	be successfully loaded will be used. If, after this, still none could be	131	the other two are not normally tried.
127	found, AnyEvent will fall back to a pure-perl event loop, which is not
128	very efficient, but should work everywhere.
129		132
130	Because AnyEvent first checks for modules that are already loaded, loading	133	Because AnyEvent first checks for modules that are already loaded, loading
131	an event model explicitly before first using AnyEvent will likely make	134	an event model explicitly before first using AnyEvent will likely make
132	that model the default. For example:	135	that model the default. For example:
133		136
…		…
135	use AnyEvent;	138	use AnyEvent;
136		139
137	# .. AnyEvent will likely default to Tk	140	# .. AnyEvent will likely default to Tk
138		141
139	The I<likely> means that, if any module loads another event model and	142	The I<likely> means that, if any module loads another event model and
140	starts using it, all bets are off. Maybe you should tell their authors to	143	starts using it, all bets are off - this case should be very rare though,
141	use AnyEvent so their modules work together with others seamlessly...	144	as very few modules hardcode event loops without announcing this very
		145	loudly.
142		146
143	The pure-perl implementation of AnyEvent is called	147	The pure-perl implementation of AnyEvent is called C<AnyEvent::Loop>. Like
144	C<AnyEvent::Impl::Perl>. Like other event modules you can load it	148	other event modules you can load it explicitly and enjoy the high
145	explicitly and enjoy the high availability of that event loop :)	149	availability of that event loop :)
146		150
147	=head1 WATCHERS	151	=head1 WATCHERS
148		152
149	AnyEvent has the central concept of a I<watcher>, which is an object that	153	AnyEvent has the central concept of a I<watcher>, which is an object that
150	stores relevant data for each kind of event you are waiting for, such as	154	stores relevant data for each kind of event you are waiting for, such as
…		…
155	callback when the event occurs (of course, only when the event model	159	callback when the event occurs (of course, only when the event model
156	is in control).	160	is in control).
157		161
158	Note that B<callbacks must not permanently change global variables>	162	Note that B<callbacks must not permanently change global variables>
159	potentially in use by the event loop (such as C<$_> or C<$[>) and that B<<	163	potentially in use by the event loop (such as C<$_> or C<$[>) and that B<<
160	callbacks must not C<die> >>. The former is good programming practise in	164	callbacks must not C<die> >>. The former is good programming practice in
161	Perl and the latter stems from the fact that exception handling differs	165	Perl and the latter stems from the fact that exception handling differs
162	widely between event loops.	166	widely between event loops.
163		167
164	To disable the watcher you have to destroy it (e.g. by setting the	168	To disable a watcher you have to destroy it (e.g. by setting the
165	variable you store it in to C<undef> or otherwise deleting all references	169	variable you store it in to C<undef> or otherwise deleting all references
166	to it).	170	to it).
167		171
168	All watchers are created by calling a method on the C<AnyEvent> class.	172	All watchers are created by calling a method on the C<AnyEvent> class.
169		173
170	Many watchers either are used with "recursion" (repeating timers for	174	Many watchers either are used with "recursion" (repeating timers for
171	example), or need to refer to their watcher object in other ways.	175	example), or need to refer to their watcher object in other ways.
172		176
173	An any way to achieve that is this pattern:	177	One way to achieve that is this pattern:
174		178
175	my $w; $w = AnyEvent->type (arg => value ..., cb => sub {	179	my $w; $w = AnyEvent->type (arg => value ..., cb => sub {
176	# you can use $w here, for example to undef it	180	# you can use $w here, for example to undef it
177	undef $w;	181	undef $w;
178	});	182	});
…		…
210		214
211	The I/O watcher might use the underlying file descriptor or a copy of it.	215	The I/O watcher might use the underlying file descriptor or a copy of it.
212	You must not close a file handle as long as any watcher is active on the	216	You must not close a file handle as long as any watcher is active on the
213	underlying file descriptor.	217	underlying file descriptor.
214		218
215	Some event loops issue spurious readyness notifications, so you should	219	Some event loops issue spurious readiness notifications, so you should
216	always use non-blocking calls when reading/writing from/to your file	220	always use non-blocking calls when reading/writing from/to your file
217	handles.	221	handles.
218		222
219	Example: wait for readability of STDIN, then read a line and disable the	223	Example: wait for readability of STDIN, then read a line and disable the
220	watcher.	224	watcher.
…		…
244		248
245	Although the callback might get passed parameters, their value and	249	Although the callback might get passed parameters, their value and
246	presence is undefined and you cannot rely on them. Portable AnyEvent	250	presence is undefined and you cannot rely on them. Portable AnyEvent
247	callbacks cannot use arguments passed to time watcher callbacks.	251	callbacks cannot use arguments passed to time watcher callbacks.
248		252
249	The callback will normally be invoked once only. If you specify another	253	The callback will normally be invoked only once. If you specify another
250	parameter, C<interval>, as a strictly positive number (> 0), then the	254	parameter, C<interval>, as a strictly positive number (> 0), then the
251	callback will be invoked regularly at that interval (in fractional	255	callback will be invoked regularly at that interval (in fractional
252	seconds) after the first invocation. If C<interval> is specified with a	256	seconds) after the first invocation. If C<interval> is specified with a
253	false value, then it is treated as if it were missing.	257	false value, then it is treated as if it were not specified at all.
254		258
255	The callback will be rescheduled before invoking the callback, but no	259	The callback will be rescheduled before invoking the callback, but no
256	attempt is done to avoid timer drift in most backends, so the interval is	260	attempt is made to avoid timer drift in most backends, so the interval is
257	only approximate.	261	only approximate.
258		262
259	Example: fire an event after 7.7 seconds.	263	Example: fire an event after 7.7 seconds.
260		264
261	my $w = AnyEvent->timer (after => 7.7, cb => sub {	265	my $w = AnyEvent->timer (after => 7.7, cb => sub {
…		…
279		283
280	While most event loops expect timers to specified in a relative way, they	284	While most event loops expect timers to specified in a relative way, they
281	use absolute time internally. This makes a difference when your clock	285	use absolute time internally. This makes a difference when your clock
282	"jumps", for example, when ntp decides to set your clock backwards from	286	"jumps", for example, when ntp decides to set your clock backwards from
283	the wrong date of 2014-01-01 to 2008-01-01, a watcher that is supposed to	287	the wrong date of 2014-01-01 to 2008-01-01, a watcher that is supposed to
284	fire "after" a second might actually take six years to finally fire.	288	fire "after a second" might actually take six years to finally fire.
285		289
286	AnyEvent cannot compensate for this. The only event loop that is conscious	290	AnyEvent cannot compensate for this. The only event loop that is conscious
287	about these issues is L<EV>, which offers both relative (ev_timer, based	291	of these issues is L<EV>, which offers both relative (ev_timer, based
288	on true relative time) and absolute (ev_periodic, based on wallclock time)	292	on true relative time) and absolute (ev_periodic, based on wallclock time)
289	timers.	293	timers.
290		294
291	AnyEvent always prefers relative timers, if available, matching the	295	AnyEvent always prefers relative timers, if available, matching the
292	AnyEvent API.	296	AnyEvent API.
…		…
314	I<In almost all cases (in all cases if you don't care), this is the	318	I<In almost all cases (in all cases if you don't care), this is the
315	function to call when you want to know the current time.>	319	function to call when you want to know the current time.>
316		320
317	This function is also often faster then C<< AnyEvent->time >>, and	321	This function is also often faster then C<< AnyEvent->time >>, and
318	thus the preferred method if you want some timestamp (for example,	322	thus the preferred method if you want some timestamp (for example,
319	L<AnyEvent::Handle> uses this to update it's activity timeouts).	323	L<AnyEvent::Handle> uses this to update its activity timeouts).
320		324
321	The rest of this section is only of relevance if you try to be very exact	325	The rest of this section is only of relevance if you try to be very exact
322	with your timing, you can skip it without bad conscience.	326	with your timing; you can skip it without a bad conscience.
323		327
324	For a practical example of when these times differ, consider L<Event::Lib>	328	For a practical example of when these times differ, consider L<Event::Lib>
325	and L<EV> and the following set-up:	329	and L<EV> and the following set-up:
326		330
327	The event loop is running and has just invoked one of your callback at	331	The event loop is running and has just invoked one of your callbacks at
328	time=500 (assume no other callbacks delay processing). In your callback,	332	time=500 (assume no other callbacks delay processing). In your callback,
329	you wait a second by executing C<sleep 1> (blocking the process for a	333	you wait a second by executing C<sleep 1> (blocking the process for a
330	second) and then (at time=501) you create a relative timer that fires	334	second) and then (at time=501) you create a relative timer that fires
331	after three seconds.	335	after three seconds.
332		336
…		…
352	difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into	356	difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into
353	account.	357	account.
354		358
355	=item AnyEvent->now_update	359	=item AnyEvent->now_update
356		360
357	Some event loops (such as L<EV> or L<AnyEvent::Impl::Perl>) cache	361	Some event loops (such as L<EV> or L<AnyEvent::Loop>) cache the current
358	the current time for each loop iteration (see the discussion of L<<	362	time for each loop iteration (see the discussion of L<< AnyEvent->now >>,
359	AnyEvent->now >>, above).	363	above).
360		364
361	When a callback runs for a long time (or when the process sleeps), then	365	When a callback runs for a long time (or when the process sleeps), then
362	this "current" time will differ substantially from the real time, which	366	this "current" time will differ substantially from the real time, which
363	might affect timers and time-outs.	367	might affect timers and time-outs.
364		368
365	When this is the case, you can call this method, which will update the	369	When this is the case, you can call this method, which will update the
366	event loop's idea of "current time".	370	event loop's idea of "current time".
		371
		372	A typical example would be a script in a web server (e.g. C<mod_perl>) -
		373	when mod_perl executes the script, then the event loop will have the wrong
		374	idea about the "current time" (being potentially far in the past, when the
		375	script ran the last time). In that case you should arrange a call to C<<
		376	AnyEvent->now_update >> each time the web server process wakes up again
		377	(e.g. at the start of your script, or in a handler).
367		378
368	Note that updating the time I<might> cause some events to be handled.	379	Note that updating the time I<might> cause some events to be handled.
369		380
370	=back	381	=back
371		382
…		…
396		407
397	Example: exit on SIGINT	408	Example: exit on SIGINT
398		409
399	my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });	410	my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });
400		411
		412	=head3 Restart Behaviour
		413
		414	While restart behaviour is up to the event loop implementation, most will
		415	not restart syscalls (that includes L<Async::Interrupt> and AnyEvent's
		416	pure perl implementation).
		417
		418	=head3 Safe/Unsafe Signals
		419
		420	Perl signals can be either "safe" (synchronous to opcode handling) or
		421	"unsafe" (asynchronous) - the former might get delayed indefinitely, the
		422	latter might corrupt your memory.
		423
		424	AnyEvent signal handlers are, in addition, synchronous to the event loop,
		425	i.e. they will not interrupt your running perl program but will only be
		426	called as part of the normal event handling (just like timer, I/O etc.
		427	callbacks, too).
		428
401	=head3 Signal Races, Delays and Workarounds	429	=head3 Signal Races, Delays and Workarounds
402		430
403	Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support attaching	431	Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support attaching
404	callbacks to signals in a generic way, which is a pity, as you cannot	432	callbacks to signals in a generic way, which is a pity, as you cannot
405	do race-free signal handling in perl, requiring C libraries for	433	do race-free signal handling in perl, requiring C libraries for
406	this. AnyEvent will try to do it's best, which means in some cases,	434	this. AnyEvent will try to do its best, which means in some cases,
407	signals will be delayed. The maximum time a signal might be delayed is	435	signals will be delayed. The maximum time a signal might be delayed is
408	specified in C<$AnyEvent::MAX_SIGNAL_LATENCY> (default: 10 seconds). This	436	specified in C<$AnyEvent::MAX_SIGNAL_LATENCY> (default: 10 seconds). This
409	variable can be changed only before the first signal watcher is created,	437	variable can be changed only before the first signal watcher is created,
410	and should be left alone otherwise. This variable determines how often	438	and should be left alone otherwise. This variable determines how often
411	AnyEvent polls for signals (in case a wake-up was missed). Higher values	439	AnyEvent polls for signals (in case a wake-up was missed). Higher values
…		…
413	saving.	441	saving.
414		442
415	All these problems can be avoided by installing the optional	443	All these problems can be avoided by installing the optional
416	L<Async::Interrupt> module, which works with most event loops. It will not	444	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>	445	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	446	(and not with L<POE> currently, as POE does its own workaround with
419	one-second latency). For those, you just have to suffer the delays.	447	one-second latency). For those, you just have to suffer the delays.
420		448
421	=head2 CHILD PROCESS WATCHERS	449	=head2 CHILD PROCESS WATCHERS
422		450
423	$w = AnyEvent->child (pid => <process id>, cb => <callback>);	451	$w = AnyEvent->child (pid => <process id>, cb => <callback>);
424		452
425	You can also watch on a child process exit and catch its exit status.	453	You can also watch for a child process exit and catch its exit status.
426		454
427	The child process is specified by the C<pid> argument (one some backends,	455	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	456	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	457	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	458	finished and an exit status is available, not on any trace events
431	(stopped/continued).	459	(stopped/continued).
432		460
…		…
454	thing in an AnyEvent program, you I<have> to create at least one	482	thing in an AnyEvent program, you I<have> to create at least one
455	watcher before you C<fork> the child (alternatively, you can call	483	watcher before you C<fork> the child (alternatively, you can call
456	C<AnyEvent::detect>).	484	C<AnyEvent::detect>).
457		485
458	As most event loops do not support waiting for child events, they will be	486	As most event loops do not support waiting for child events, they will be
459	emulated by AnyEvent in most cases, in which the latency and race problems	487	emulated by AnyEvent in most cases, in which case the latency and race
460	mentioned in the description of signal watchers apply.	488	problems mentioned in the description of signal watchers apply.
461		489
462	Example: fork a process and wait for it	490	Example: fork a process and wait for it
463		491
464	my $done = AnyEvent->condvar;	492	my $done = AnyEvent->condvar;
465		493
…		…
479		507
480	=head2 IDLE WATCHERS	508	=head2 IDLE WATCHERS
481		509
482	$w = AnyEvent->idle (cb => <callback>);	510	$w = AnyEvent->idle (cb => <callback>);
483		511
484	Sometimes there is a need to do something, but it is not so important	512	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	513	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		514
489	Idle watchers ideally get invoked when the event loop has nothing	515	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	516	is not so important (or wise) to do it instantly. The callback will be
491	events. Instead of blocking, the idle watcher is invoked.	517	invoked only when there is "nothing better to do", which is usually
		518	defined as "all outstanding events have been handled and no new events
		519	have been detected". That means that idle watchers ideally get invoked
		520	when the event loop has just polled for new events but none have been
		521	detected. Instead of blocking to wait for more events, the idle watchers
		522	will be invoked.
492		523
493	Most event loops unfortunately do not really support idle watchers (only	524	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	525	EV, Event and Glib do it in a usable fashion) - for the rest, AnyEvent
495	will simply call the callback "from time to time".	526	will simply call the callback "from time to time".
496		527
497	Example: read lines from STDIN, but only process them when the	528	Example: read lines from STDIN, but only process them when the
498	program is otherwise idle:	529	program is otherwise idle:
…		…
526	will actively watch for new events and call your callbacks.	557	will actively watch for new events and call your callbacks.
527		558
528	AnyEvent is slightly different: it expects somebody else to run the event	559	AnyEvent is slightly different: it expects somebody else to run the event
529	loop and will only block when necessary (usually when told by the user).	560	loop and will only block when necessary (usually when told by the user).
530		561
531	The instrument to do that is called a "condition variable", so called	562	The tool to do that is called a "condition variable", so called because
532	because they represent a condition that must become true.	563	they represent a condition that must become true.
533		564
534	Now is probably a good time to look at the examples further below.	565	Now is probably a good time to look at the examples further below.
535		566
536	Condition variables can be created by calling the C<< AnyEvent->condvar	567	Condition variables can be created by calling the C<< AnyEvent->condvar
537	>> method, usually without arguments. The only argument pair allowed is	568	>> method, usually without arguments. The only argument pair allowed is
…		…
542	After creation, the condition variable is "false" until it becomes "true"	573	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	574	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<<	575	were a callback, read about the caveats in the description for the C<<
545	->send >> method).	576	->send >> method).
546		577
547	Condition variables are similar to callbacks, except that you can	578	Since condition variables are the most complex part of the AnyEvent API, here are
548	optionally wait for them. They can also be called merge points - points	579	some different mental models of what they are - pick the ones you can connect to:
549	in time where multiple outstanding events have been processed. And yet	580
550	another way to call them is transactions - each condition variable can be	581	=over 4
551	used to represent a transaction, which finishes at some point and delivers	582
552	a result. And yet some people know them as "futures" - a promise to	583	=item * Condition variables are like callbacks - you can call them (and pass them instead
553	compute/deliver something that you can wait for.	584	of callbacks). Unlike callbacks however, you can also wait for them to be called.
		585
		586	=item * Condition variables are signals - one side can emit or send them,
		587	the other side can wait for them, or install a handler that is called when
		588	the signal fires.
		589
		590	=item * Condition variables are like "Merge Points" - points in your program
		591	where you merge multiple independent results/control flows into one.
		592
		593	=item * Condition variables represent a transaction - functions that start
		594	some kind of transaction can return them, leaving the caller the choice
		595	between waiting in a blocking fashion, or setting a callback.
		596
		597	=item * Condition variables represent future values, or promises to deliver
		598	some result, long before the result is available.
		599
		600	=back
554		601
555	Condition variables are very useful to signal that something has finished,	602	Condition variables are very useful to signal that something has finished,
556	for example, if you write a module that does asynchronous http requests,	603	for example, if you write a module that does asynchronous http requests,
557	then a condition variable would be the ideal candidate to signal the	604	then a condition variable would be the ideal candidate to signal the
558	availability of results. The user can either act when the callback is	605	availability of results. The user can either act when the callback is
…		…
571		618
572	Condition variables are represented by hash refs in perl, and the keys	619	Condition variables are represented by hash refs in perl, and the keys
573	used by AnyEvent itself are all named C<_ae_XXX> to make subclassing	620	used by AnyEvent itself are all named C<_ae_XXX> to make subclassing
574	easy (it is often useful to build your own transaction class on top of	621	easy (it is often useful to build your own transaction class on top of
575	AnyEvent). To subclass, use C<AnyEvent::CondVar> as base class and call	622	AnyEvent). To subclass, use C<AnyEvent::CondVar> as base class and call
576	it's C<new> method in your own C<new> method.	623	its C<new> method in your own C<new> method.
577		624
578	There are two "sides" to a condition variable - the "producer side" which	625	There are two "sides" to a condition variable - the "producer side" which
579	eventually calls C<< -> send >>, and the "consumer side", which waits	626	eventually calls C<< -> send >>, and the "consumer side", which waits
580	for the send to occur.	627	for the send to occur.
581		628
582	Example: wait for a timer.	629	Example: wait for a timer.
583		630
584	# wait till the result is ready	631	# condition: "wait till the timer is fired"
585	my $result_ready = AnyEvent->condvar;	632	my $timer_fired = AnyEvent->condvar;
586		633
587	# do something such as adding a timer	634	# create the timer - we could wait for, say
588	# or socket watcher the calls $result_ready->send	635	# a handle becomign ready, or even an
589	# when the "result" is ready.	636	# AnyEvent::HTTP request to finish, but
590	# in this case, we simply use a timer:	637	# in this case, we simply use a timer:
591	my $w = AnyEvent->timer (	638	my $w = AnyEvent->timer (
592	after => 1,	639	after => 1,
593	cb => sub { $result_ready->send },	640	cb => sub { $timer_fired->send },
594	);	641	);
595		642
596	# this "blocks" (while handling events) till the callback	643	# this "blocks" (while handling events) till the callback
597	# calls -<send	644	# calls ->send
598	$result_ready->recv;	645	$timer_fired->recv;
599		646
600	Example: wait for a timer, but take advantage of the fact that condition	647	Example: wait for a timer, but take advantage of the fact that condition
601	variables are also callable directly.	648	variables are also callable directly.
602		649
603	my $done = AnyEvent->condvar;	650	my $done = AnyEvent->condvar;
…		…
646	they were a code reference). Calling them directly is the same as calling	693	they were a code reference). Calling them directly is the same as calling
647	C<send>.	694	C<send>.
648		695
649	=item $cv->croak ($error)	696	=item $cv->croak ($error)
650		697
651	Similar to send, but causes all call's to C<< ->recv >> to invoke	698	Similar to send, but causes all calls to C<< ->recv >> to invoke
652	C<Carp::croak> with the given error message/object/scalar.	699	C<Carp::croak> with the given error message/object/scalar.
653		700
654	This can be used to signal any errors to the condition variable	701	This can be used to signal any errors to the condition variable
655	user/consumer. Doing it this way instead of calling C<croak> directly	702	user/consumer. Doing it this way instead of calling C<croak> directly
656	delays the error detetcion, but has the overwhelmign advantage that it	703	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	704	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	705	deep in some event callback with no connection to the actual code causing
659	the problem.	706	the problem.
660		707
661	=item $cv->begin ([group callback])	708	=item $cv->begin ([group callback])
662		709
663	=item $cv->end	710	=item $cv->end
…		…
666	one. For example, a function that pings many hosts in parallel might want	713	one. For example, a function that pings many hosts in parallel might want
667	to use a condition variable for the whole process.	714	to use a condition variable for the whole process.
668		715
669	Every call to C<< ->begin >> will increment a counter, and every call to	716	Every call to C<< ->begin >> will increment a counter, and every call to
670	C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end	717	C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end
671	>>, the (last) callback passed to C<begin> will be executed. That callback	718	>>, the (last) callback passed to C<begin> will be executed, passing the
672	is I<supposed> to call C<< ->send >>, but that is not required. If no	719	condvar as first argument. That callback is I<supposed> to call C<< ->send
673	callback was set, C<send> will be called without any arguments.	720	>>, but that is not required. If no group callback was set, C<send> will
		721	be called without any arguments.
674		722
675	You can think of C<< $cv->send >> giving you an OR condition (one call	723	You can think of C<< $cv->send >> giving you an OR condition (one call
676	sends), while C<< $cv->begin >> and C<< $cv->end >> giving you an AND	724	sends), while C<< $cv->begin >> and C<< $cv->end >> giving you an AND
677	condition (all C<begin> calls must be C<end>'ed before the condvar sends).	725	condition (all C<begin> calls must be C<end>'ed before the condvar sends).
678		726
…		…
700	one call to C<begin>, so the condvar waits for all calls to C<end> before	748	one call to C<begin>, so the condvar waits for all calls to C<end> before
701	sending.	749	sending.
702		750
703	The ping example mentioned above is slightly more complicated, as the	751	The ping example mentioned above is slightly more complicated, as the
704	there are results to be passwd back, and the number of tasks that are	752	there are results to be passwd back, and the number of tasks that are
705	begung can potentially be zero:	753	begun can potentially be zero:
706		754
707	my $cv = AnyEvent->condvar;	755	my $cv = AnyEvent->condvar;
708		756
709	my %result;	757	my %result;
710	$cv->begin (sub { $cv->send (\%result) });	758	$cv->begin (sub { shift->send (\%result) });
711		759
712	for my $host (@list_of_hosts) {	760	for my $host (@list_of_hosts) {
713	$cv->begin;	761	$cv->begin;
714	ping_host_then_call_callback $host, sub {	762	ping_host_then_call_callback $host, sub {
715	$result{$host} = ...;	763	$result{$host} = ...;
…		…
731	to be called once the counter reaches C<0>, and second, it ensures that	779	to be called once the counter reaches C<0>, and second, it ensures that
732	C<send> is called even when C<no> hosts are being pinged (the loop	780	C<send> is called even when C<no> hosts are being pinged (the loop
733	doesn't execute once).	781	doesn't execute once).
734		782
735	This is the general pattern when you "fan out" into multiple (but	783	This is the general pattern when you "fan out" into multiple (but
736	potentially none) subrequests: use an outer C<begin>/C<end> pair to set	784	potentially zero) subrequests: use an outer C<begin>/C<end> pair to set
737	the callback and ensure C<end> is called at least once, and then, for each	785	the callback and ensure C<end> is called at least once, and then, for each
738	subrequest you start, call C<begin> and for each subrequest you finish,	786	subrequest you start, call C<begin> and for each subrequest you finish,
739	call C<end>.	787	call C<end>.
740		788
741	=back	789	=back
…		…
748	=over 4	796	=over 4
749		797
750	=item $cv->recv	798	=item $cv->recv
751		799
752	Wait (blocking if necessary) until the C<< ->send >> or C<< ->croak	800	Wait (blocking if necessary) until the C<< ->send >> or C<< ->croak
753	>> methods have been called on c<$cv>, while servicing other watchers	801	>> methods have been called on C<$cv>, while servicing other watchers
754	normally.	802	normally.
755		803
756	You can only wait once on a condition - additional calls are valid but	804	You can only wait once on a condition - additional calls are valid but
757	will return immediately.	805	will return immediately.
758		806
…		…
775	caller decide whether the call will block or not (for example, by coupling	823	caller decide whether the call will block or not (for example, by coupling
776	condition variables with some kind of request results and supporting	824	condition variables with some kind of request results and supporting
777	callbacks so the caller knows that getting the result will not block,	825	callbacks so the caller knows that getting the result will not block,
778	while still supporting blocking waits if the caller so desires).	826	while still supporting blocking waits if the caller so desires).
779		827
780	You can ensure that C<< -recv >> never blocks by setting a callback and	828	You can ensure that C<< ->recv >> never blocks by setting a callback and
781	only calling C<< ->recv >> from within that callback (or at a later	829	only calling C<< ->recv >> from within that callback (or at a later
782	time). This will work even when the event loop does not support blocking	830	time). This will work even when the event loop does not support blocking
783	waits otherwise.	831	waits otherwise.
784		832
785	=item $bool = $cv->ready	833	=item $bool = $cv->ready
…		…
790	=item $cb = $cv->cb ($cb->($cv))	838	=item $cb = $cv->cb ($cb->($cv))
791		839
792	This is a mutator function that returns the callback set and optionally	840	This is a mutator function that returns the callback set and optionally
793	replaces it before doing so.	841	replaces it before doing so.
794		842
795	The callback will be called when the condition becomes (or already was)	843	The callback will be called when the condition becomes "true", i.e. when
796	"true", i.e. when C<send> or C<croak> are called (or were called), with	844	C<send> or C<croak> are called, with the only argument being the
797	the only argument being the condition variable itself. Calling C<recv>	845	condition variable itself. If the condition is already true, the
		846	callback is called immediately when it is set. Calling C<recv> inside
798	inside the callback or at any later time is guaranteed not to block.	847	the callback or at any later time is guaranteed not to block.
799		848
800	=back	849	=back
801		850
802	=head1 SUPPORTED EVENT LOOPS/BACKENDS	851	=head1 SUPPORTED EVENT LOOPS/BACKENDS
803		852
…		…
811	use. If EV is not installed, then AnyEvent will fall back to its own	860	use. If EV is not installed, then AnyEvent will fall back to its own
812	pure-perl implementation, which is available everywhere as it comes with	861	pure-perl implementation, which is available everywhere as it comes with
813	AnyEvent itself.	862	AnyEvent itself.
814		863
815	AnyEvent::Impl::EV based on EV (interface to libev, best choice).	864	AnyEvent::Impl::EV based on EV (interface to libev, best choice).
816	AnyEvent::Impl::Perl pure-perl implementation, fast and portable.	865	AnyEvent::Impl::Perl pure-perl AnyEvent::Loop, fast and portable.
817		866
818	=item Backends that are transparently being picked up when they are used.	867	=item Backends that are transparently being picked up when they are used.
819		868
820	These will be used when they are currently loaded when the first watcher	869	These will be used if they are already loaded when the first watcher
821	is created, in which case it is assumed that the application is using	870	is created, in which case it is assumed that the application is using
822	them. This means that AnyEvent will automatically pick the right backend	871	them. This means that AnyEvent will automatically pick the right backend
823	when the main program loads an event module before anything starts to	872	when the main program loads an event module before anything starts to
824	create watchers. Nothing special needs to be done by the main program.	873	create watchers. Nothing special needs to be done by the main program.
825		874
…		…
827	AnyEvent::Impl::Glib based on Glib, slow but very stable.	876	AnyEvent::Impl::Glib based on Glib, slow but very stable.
828	AnyEvent::Impl::Tk based on Tk, very broken.	877	AnyEvent::Impl::Tk based on Tk, very broken.
829	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.	878	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
830	AnyEvent::Impl::POE based on POE, very slow, some limitations.	879	AnyEvent::Impl::POE based on POE, very slow, some limitations.
831	AnyEvent::Impl::Irssi used when running within irssi.	880	AnyEvent::Impl::Irssi used when running within irssi.
		881	AnyEvent::Impl::IOAsync based on IO::Async.
		882	AnyEvent::Impl::Cocoa based on Cocoa::EventLoop.
		883	AnyEvent::Impl::FLTK based on FLTK (fltk 2 binding).
832		884
833	=item Backends with special needs.	885	=item Backends with special needs.
834		886
835	Qt requires the Qt::Application to be instantiated first, but will	887	Qt requires the Qt::Application to be instantiated first, but will
836	otherwise be picked up automatically. As long as the main program	888	otherwise be picked up automatically. As long as the main program
837	instantiates the application before any AnyEvent watchers are created,	889	instantiates the application before any AnyEvent watchers are created,
838	everything should just work.	890	everything should just work.
839		891
840	AnyEvent::Impl::Qt based on Qt.	892	AnyEvent::Impl::Qt based on Qt.
841		893
842	Support for IO::Async can only be partial, as it is too broken and
843	architecturally limited to even support the AnyEvent API. It also
844	is the only event loop that needs the loop to be set explicitly, so
845	it can only be used by a main program knowing about AnyEvent. See
846	L<AnyEvent::Impl::Async> for the gory details.
847
848	AnyEvent::Impl::IOAsync based on IO::Async, cannot be autoprobed.
849
850	=item Event loops that are indirectly supported via other backends.	894	=item Event loops that are indirectly supported via other backends.
851		895
852	Some event loops can be supported via other modules:	896	Some event loops can be supported via other modules:
853		897
854	There is no direct support for WxWidgets (L<Wx>) or L<Prima>.	898	There is no direct support for WxWidgets (L<Wx>) or L<Prima>.
…		…
879	Contains C<undef> until the first watcher is being created, before the	923	Contains C<undef> until the first watcher is being created, before the
880	backend has been autodetected.	924	backend has been autodetected.
881		925
882	Afterwards it contains the event model that is being used, which is the	926	Afterwards it contains the event model that is being used, which is the
883	name of the Perl class implementing the model. This class is usually one	927	name of the Perl class implementing the model. This class is usually one
884	of the C<AnyEvent::Impl:xxx> modules, but can be any other class in the	928	of the C<AnyEvent::Impl::xxx> modules, but can be any other class in the
885	case AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode> it	929	case AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode> it
886	will be C<urxvt::anyevent>).	930	will be C<urxvt::anyevent>).
887		931
888	=item AnyEvent::detect	932	=item AnyEvent::detect
889		933
890	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model	934	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model
891	if necessary. You should only call this function right before you would	935	if necessary. You should only call this function right before you would
892	have created an AnyEvent watcher anyway, that is, as late as possible at	936	have created an AnyEvent watcher anyway, that is, as late as possible at
893	runtime, and not e.g. while initialising of your module.	937	runtime, and not e.g. during initialisation of your module.
		938
		939	The effect of calling this function is as if a watcher had been created
		940	(specifically, actions that happen "when the first watcher is created"
		941	happen when calling detetc as well).
894		942
895	If you need to do some initialisation before AnyEvent watchers are	943	If you need to do some initialisation before AnyEvent watchers are
896	created, use C<post_detect>.	944	created, use C<post_detect>.
897		945
898	=item $guard = AnyEvent::post_detect { BLOCK }	946	=item $guard = AnyEvent::post_detect { BLOCK }
899		947
900	Arranges for the code block to be executed as soon as the event model is	948	Arranges for the code block to be executed as soon as the event model is
901	autodetected (or immediately if this has already happened).	949	autodetected (or immediately if that has already happened).
902		950
903	The block will be executed I<after> the actual backend has been detected	951	The block will be executed I<after> the actual backend has been detected
904	(C<$AnyEvent::MODEL> is set), but I<before> any watchers have been	952	(C<$AnyEvent::MODEL> is set), but I<before> any watchers have been
905	created, so it is possible to e.g. patch C<@AnyEvent::ISA> or do	953	created, so it is possible to e.g. patch C<@AnyEvent::ISA> or do
906	other initialisations - see the sources of L<AnyEvent::Strict> or	954	other initialisations - see the sources of L<AnyEvent::Strict> or
…		…
915	that automatically removes the callback again when it is destroyed (or	963	that automatically removes the callback again when it is destroyed (or
916	C<undef> when the hook was immediately executed). See L<AnyEvent::AIO> for	964	C<undef> when the hook was immediately executed). See L<AnyEvent::AIO> for
917	a case where this is useful.	965	a case where this is useful.
918		966
919	Example: Create a watcher for the IO::AIO module and store it in	967	Example: Create a watcher for the IO::AIO module and store it in
920	C<$WATCHER>. Only do so after the event loop is initialised, though.	968	C<$WATCHER>, but do so only do so after the event loop is initialised.
921		969
922	our WATCHER;	970	our WATCHER;
923		971
924	my $guard = AnyEvent::post_detect {	972	my $guard = AnyEvent::post_detect {
925	$WATCHER = AnyEvent->io (fh => IO::AIO::poll_fileno, poll => 'r', cb => \&IO::AIO::poll_cb);	973	$WATCHER = AnyEvent->io (fh => IO::AIO::poll_fileno, poll => 'r', cb => \&IO::AIO::poll_cb);
…		…
933	$WATCHER ||= $guard;	981	$WATCHER ||= $guard;
934		982
935	=item @AnyEvent::post_detect	983	=item @AnyEvent::post_detect
936		984
937	If there are any code references in this array (you can C<push> to it	985	If there are any code references in this array (you can C<push> to it
938	before or after loading AnyEvent), then they will called directly after	986	before or after loading AnyEvent), then they will be called directly
939	the event loop has been chosen.	987	after the event loop has been chosen.
940		988
941	You should check C<$AnyEvent::MODEL> before adding to this array, though:	989	You should check C<$AnyEvent::MODEL> before adding to this array, though:
942	if it is defined then the event loop has already been detected, and the	990	if it is defined then the event loop has already been detected, and the
943	array will be ignored.	991	array will be ignored.
944		992
945	Best use C<AnyEvent::post_detect { BLOCK }> when your application allows	993	Best use C<AnyEvent::post_detect { BLOCK }> when your application allows
946	it,as it takes care of these details.	994	it, as it takes care of these details.
947		995
948	This variable is mainly useful for modules that can do something useful	996	This variable is mainly useful for modules that can do something useful
949	when AnyEvent is used and thus want to know when it is initialised, but do	997	when AnyEvent is used and thus want to know when it is initialised, but do
950	not need to even load it by default. This array provides the means to hook	998	not need to even load it by default. This array provides the means to hook
951	into AnyEvent passively, without loading it.	999	into AnyEvent passively, without loading it.
952		1000
		1001	Example: To load Coro::AnyEvent whenever Coro and AnyEvent are used
		1002	together, you could put this into Coro (this is the actual code used by
		1003	Coro to accomplish this):
		1004
		1005	if (defined $AnyEvent::MODEL) {
		1006	# AnyEvent already initialised, so load Coro::AnyEvent
		1007	require Coro::AnyEvent;
		1008	} else {
		1009	# AnyEvent not yet initialised, so make sure to load Coro::AnyEvent
		1010	# as soon as it is
		1011	push @AnyEvent::post_detect, sub { require Coro::AnyEvent };
		1012	}
		1013
		1014	=item AnyEvent::postpone { BLOCK }
		1015
		1016	Arranges for the block to be executed as soon as possible, but not before
		1017	the call itself returns. In practise, the block will be executed just
		1018	before the event loop polls for new events, or shortly afterwards.
		1019
		1020	This function never returns anything (to make the C<return postpone { ...
		1021	}> idiom more useful.
		1022
		1023	To understand the usefulness of this function, consider a function that
		1024	asynchronously does something for you and returns some transaction
		1025	object or guard to let you cancel the operation. For example,
		1026	C<AnyEvent::Socket::tcp_connect>:
		1027
		1028	# start a conenction attempt unless one is active
		1029	$self->{connect_guard} ||= AnyEvent::Socket::tcp_connect "www.example.net", 80, sub {
		1030	delete $self->{connect_guard};
		1031	...
		1032	};
		1033
		1034	Imagine that this function could instantly call the callback, for
		1035	example, because it detects an obvious error such as a negative port
		1036	number. Invoking the callback before the function returns causes problems
		1037	however: the callback will be called and will try to delete the guard
		1038	object. But since the function hasn't returned yet, there is nothing to
		1039	delete. When the function eventually returns it will assign the guard
		1040	object to C<< $self->{connect_guard} >>, where it will likely never be
		1041	deleted, so the program thinks it is still trying to connect.
		1042
		1043	This is where C<AnyEvent::postpone> should be used. Instead of calling the
		1044	callback directly on error:
		1045
		1046	$cb->(undef), return # signal error to callback, BAD!
		1047	if $some_error_condition;
		1048
		1049	It should use C<postpone>:
		1050
		1051	AnyEvent::postpone { $cb->(undef) }, return # signal error to callback, later
		1052	if $some_error_condition;
		1053
		1054	=item AnyEvent::log $level, $msg[, @args]
		1055
		1056	Log the given C<$msg> at the given C<$level>.
		1057
		1058	If L<AnyEvent::Log> is not loaded then this function makes a simple test
		1059	to see whether the message will be logged. If the test succeeds it will
		1060	load AnyEvent::Log and call C<AnyEvent::Log::log> - consequently, look at
		1061	the L<AnyEvent::Log> documentation for details.
		1062
		1063	If the test fails it will simply return.
		1064
		1065	If you want to sprinkle loads of logging calls around your code, consider
		1066	creating a logger callback with the C<AnyEvent::Log::logger> function,
		1067	which can reduce typing, codesize and can reduce the logging overhead
		1068	enourmously.
		1069
953	=back	1070	=back
954		1071
955	=head1 WHAT TO DO IN A MODULE	1072	=head1 WHAT TO DO IN A MODULE
956		1073
957	As a module author, you should C<use AnyEvent> and call AnyEvent methods	1074	As a module author, you should C<use AnyEvent> and call AnyEvent methods
…		…
967	because it will stall the whole program, and the whole point of using	1084	because it will stall the whole program, and the whole point of using
968	events is to stay interactive.	1085	events is to stay interactive.
969		1086
970	It is fine, however, to call C<< ->recv >> when the user of your module	1087	It is fine, however, to call C<< ->recv >> when the user of your module
971	requests it (i.e. if you create a http request object ad have a method	1088	requests it (i.e. if you create a http request object ad have a method
972	called C<results> that returns the results, it should call C<< ->recv >>	1089	called C<results> that returns the results, it may call C<< ->recv >>
973	freely, as the user of your module knows what she is doing. always).	1090	freely, as the user of your module knows what she is doing. Always).
974		1091
975	=head1 WHAT TO DO IN THE MAIN PROGRAM	1092	=head1 WHAT TO DO IN THE MAIN PROGRAM
976		1093
977	There will always be a single main program - the only place that should	1094	There will always be a single main program - the only place that should
978	dictate which event model to use.	1095	dictate which event model to use.
979		1096
980	If it doesn't care, it can just "use AnyEvent" and use it itself, or not	1097	If the program is not event-based, it need not do anything special, even
981	do anything special (it does not need to be event-based) and let AnyEvent	1098	when it depends on a module that uses an AnyEvent. If the program itself
982	decide which implementation to chose if some module relies on it.	1099	uses AnyEvent, but does not care which event loop is used, all it needs
		1100	to do is C<use AnyEvent>. In either case, AnyEvent will choose the best
		1101	available loop implementation.
983		1102
984	If the main program relies on a specific event model - for example, in	1103	If the main program relies on a specific event model - for example, in
985	Gtk2 programs you have to rely on the Glib module - you should load the	1104	Gtk2 programs you have to rely on the Glib module - you should load the
986	event module before loading AnyEvent or any module that uses it: generally	1105	event module before loading AnyEvent or any module that uses it: generally
987	speaking, you should load it as early as possible. The reason is that	1106	speaking, you should load it as early as possible. The reason is that
988	modules might create watchers when they are loaded, and AnyEvent will	1107	modules might create watchers when they are loaded, and AnyEvent will
989	decide on the event model to use as soon as it creates watchers, and it	1108	decide on the event model to use as soon as it creates watchers, and it
990	might chose the wrong one unless you load the correct one yourself.	1109	might choose the wrong one unless you load the correct one yourself.
991		1110
992	You can chose to use a pure-perl implementation by loading the	1111	You can chose to use a pure-perl implementation by loading the
993	C<AnyEvent::Impl::Perl> module, which gives you similar behaviour	1112	C<AnyEvent::Loop> module, which gives you similar behaviour
994	everywhere, but letting AnyEvent chose the model is generally better.	1113	everywhere, but letting AnyEvent chose the model is generally better.
995		1114
996	=head2 MAINLOOP EMULATION	1115	=head2 MAINLOOP EMULATION
997		1116
998	Sometimes (often for short test scripts, or even standalone programs who	1117	Sometimes (often for short test scripts, or even standalone programs who
…		…
1011		1130
1012		1131
1013	=head1 OTHER MODULES	1132	=head1 OTHER MODULES
1014		1133
1015	The following is a non-exhaustive list of additional modules that use	1134	The following is a non-exhaustive list of additional modules that use
1016	AnyEvent as a client and can therefore be mixed easily with other AnyEvent	1135	AnyEvent as a client and can therefore be mixed easily with other
1017	modules and other event loops in the same program. Some of the modules	1136	AnyEvent modules and other event loops in the same program. Some of the
1018	come with AnyEvent, most are available via CPAN.	1137	modules come as part of AnyEvent, the others are available via CPAN (see
		1138	L<http://search.cpan.org/search?m=module&q=anyevent%3A%3A*> for
		1139	a longer non-exhaustive list), and the list is heavily biased towards
		1140	modules of the AnyEvent author himself :)
1019		1141
1020	=over 4	1142	=over 4
1021		1143
1022	=item L<AnyEvent::Util>	1144	=item L<AnyEvent::Util>
1023		1145
1024	Contains various utility functions that replace often-used but blocking	1146	Contains various utility functions that replace often-used blocking
1025	functions such as C<inet_aton> by event-/callback-based versions.	1147	functions such as C<inet_aton> with event/callback-based versions.
1026		1148
1027	=item L<AnyEvent::Socket>	1149	=item L<AnyEvent::Socket>
1028		1150
1029	Provides various utility functions for (internet protocol) sockets,	1151	Provides various utility functions for (internet protocol) sockets,
1030	addresses and name resolution. Also functions to create non-blocking tcp	1152	addresses and name resolution. Also functions to create non-blocking tcp
…		…
1032		1154
1033	=item L<AnyEvent::Handle>	1155	=item L<AnyEvent::Handle>
1034		1156
1035	Provide read and write buffers, manages watchers for reads and writes,	1157	Provide read and write buffers, manages watchers for reads and writes,
1036	supports raw and formatted I/O, I/O queued and fully transparent and	1158	supports raw and formatted I/O, I/O queued and fully transparent and
1037	non-blocking SSL/TLS (via L<AnyEvent::TLS>.	1159	non-blocking SSL/TLS (via L<AnyEvent::TLS>).
1038		1160
1039	=item L<AnyEvent::DNS>	1161	=item L<AnyEvent::DNS>
1040		1162
1041	Provides rich asynchronous DNS resolver capabilities.	1163	Provides rich asynchronous DNS resolver capabilities.
1042		1164
		1165	=item L<AnyEvent::HTTP>, L<AnyEvent::IRC>, L<AnyEvent::XMPP>, L<AnyEvent::GPSD>, L<AnyEvent::IGS>, L<AnyEvent::FCP>
		1166
		1167	Implement event-based interfaces to the protocols of the same name (for
		1168	the curious, IGS is the International Go Server and FCP is the Freenet
		1169	Client Protocol).
		1170
1043	=item L<AnyEvent::HTTP>	1171	=item L<AnyEvent::AIO>
1044		1172
1045	A simple-to-use HTTP library that is capable of making a lot of concurrent	1173	Truly asynchronous (as opposed to non-blocking) I/O, should be in the
1046	HTTP requests.	1174	toolbox of every event programmer. AnyEvent::AIO transparently fuses
		1175	L<IO::AIO> and AnyEvent together, giving AnyEvent access to event-based
		1176	file I/O, and much more.
		1177
		1178	=item L<AnyEvent::Filesys::Notify>
		1179
		1180	AnyEvent is good for non-blocking stuff, but it can't detect file or
		1181	path changes (e.g. "watch this directory for new files", "watch this
		1182	file for changes"). The L<AnyEvent::Filesys::Notify> module promises to
		1183	do just that in a portbale fashion, supporting inotify on GNU/Linux and
		1184	some weird, without doubt broken, stuff on OS X to monitor files. It can
		1185	fall back to blocking scans at regular intervals transparently on other
		1186	platforms, so it's about as portable as it gets.
		1187
		1188	(I haven't used it myself, but I haven't heard anybody complaining about
		1189	it yet).
		1190
		1191	=item L<AnyEvent::DBI>
		1192
		1193	Executes L<DBI> requests asynchronously in a proxy process for you,
		1194	notifying you in an event-based way when the operation is finished.
1047		1195
1048	=item L<AnyEvent::HTTPD>	1196	=item L<AnyEvent::HTTPD>
1049		1197
1050	Provides a simple web application server framework.	1198	A simple embedded webserver.
1051		1199
1052	=item L<AnyEvent::FastPing>	1200	=item L<AnyEvent::FastPing>
1053		1201
1054	The fastest ping in the west.	1202	The fastest ping in the west.
1055		1203
1056	=item L<AnyEvent::DBI>
1057
1058	Executes L<DBI> requests asynchronously in a proxy process.
1059
1060	=item L<AnyEvent::AIO>
1061
1062	Truly asynchronous I/O, should be in the toolbox of every event
1063	programmer. AnyEvent::AIO transparently fuses L<IO::AIO> and AnyEvent
1064	together.
1065
1066	=item L<AnyEvent::BDB>
1067
1068	Truly asynchronous Berkeley DB access. AnyEvent::BDB transparently fuses
1069	L<BDB> and AnyEvent together.
1070
1071	=item L<AnyEvent::GPSD>
1072
1073	A non-blocking interface to gpsd, a daemon delivering GPS information.
1074
1075	=item L<AnyEvent::IRC>
1076
1077	AnyEvent based IRC client module family (replacing the older Net::IRC3).
1078
1079	=item L<AnyEvent::XMPP>
1080
1081	AnyEvent based XMPP (Jabber protocol) module family (replacing the older
1082	Net::XMPP2>.
1083
1084	=item L<AnyEvent::IGS>
1085
1086	A non-blocking interface to the Internet Go Server protocol (used by
1087	L<App::IGS>).
1088
1089	=item L<Net::FCP>
1090
1091	AnyEvent-based implementation of the Freenet Client Protocol, birthplace
1092	of AnyEvent.
1093
1094	=item L<Event::ExecFlow>
1095
1096	High level API for event-based execution flow control.
1097
1098	=item L<Coro>	1204	=item L<Coro>
1099		1205
1100	Has special support for AnyEvent via L<Coro::AnyEvent>.	1206	Has special support for AnyEvent via L<Coro::AnyEvent>, which allows you
		1207	to simply invert the flow control - don't call us, we will call you:
		1208
		1209	async {
		1210	Coro::AnyEvent::sleep 5; # creates a 5s timer and waits for it
		1211	print "5 seconds later!\n";
		1212
		1213	Coro::AnyEvent::readable *STDIN; # uses an I/O watcher
		1214	my $line = <STDIN>; # works for ttys
		1215
		1216	AnyEvent::HTTP::http_get "url", Coro::rouse_cb;
		1217	my ($body, $hdr) = Coro::rouse_wait;
		1218	};
1101		1219
1102	=back	1220	=back
1103		1221
1104	=cut	1222	=cut
1105		1223
1106	package AnyEvent;	1224	package AnyEvent;
1107		1225
1108	# basically a tuned-down version of common::sense	1226	# basically a tuned-down version of common::sense
1109	sub common_sense {	1227	sub common_sense {
1110	# no warnings	1228	# from common:.sense 3.4
1111	${^WARNING_BITS} ^= ${^WARNING_BITS};	1229	${^WARNING_BITS} ^= ${^WARNING_BITS} ^ "\x3c\x3f\x33\x00\x0f\xf0\x0f\xc0\xf0\xfc\x33\x00";
1112	# use strict vars subs	1230	# use strict vars subs - NO UTF-8, as Util.pm doesn't like this atm. (uts46data.pl)
1113	$^H |= 0x00000600;	1231	$^H |= 0x00000600;
1114	}	1232	}
1115		1233
1116	BEGIN { AnyEvent::common_sense }	1234	BEGIN { AnyEvent::common_sense }
1117		1235
1118	use Carp ();	1236	use Carp ();
1119		1237
1120	our $VERSION = '5.0';	1238	our $VERSION = '6.02';
1121	our $MODEL;	1239	our $MODEL;
1122		1240
1123	our $AUTOLOAD;
1124	our @ISA;	1241	our @ISA;
1125		1242
1126	our @REGISTRY;	1243	our @REGISTRY;
1127		1244
1128	our $WIN32;
1129
1130	our $VERBOSE;	1245	our $VERBOSE;
1131		1246
1132	BEGIN {	1247	BEGIN {
1133	eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }";	1248	require "AnyEvent/constants.pl";
		1249
1134	eval "sub TAINT(){ " . (${^TAINT}*1) . " }";	1250	eval "sub TAINT (){" . (${^TAINT}*1) . "}";
1135		1251
1136	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}	1252	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}
1137	if ${^TAINT};	1253	if ${^TAINT};
1138		1254
		1255	$ENV{"PERL_ANYEVENT_$_"} = $ENV{"AE_$_"}
		1256	for grep s/^AE_// && !exists $ENV{"PERL_ANYEVENT_$_"}, keys %ENV;
		1257
		1258	@ENV{grep /^PERL_ANYEVENT_/, keys %ENV} = ()
		1259	if ${^TAINT};
		1260
1139	$VERBOSE = $ENV{PERL_ANYEVENT_VERBOSE}*1;	1261	$VERBOSE = $ENV{PERL_ANYEVENT_VERBOSE}*1;
1140
1141	}	1262	}
1142		1263
1143	our $MAX_SIGNAL_LATENCY = 10;	1264	our $MAX_SIGNAL_LATENCY = 10;
1144		1265
1145	our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred	1266	our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred
…		…
1149	$PROTOCOL{$_} = ++$idx	1270	$PROTOCOL{$_} = ++$idx
1150	for reverse split /\s*,\s*/,	1271	for reverse split /\s*,\s*/,
1151	$ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";	1272	$ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";
1152	}	1273	}
1153		1274
		1275	our @post_detect;
		1276
		1277	sub post_detect(&) {
		1278	my ($cb) = @_;
		1279
		1280	push @post_detect, $cb;
		1281
		1282	defined wantarray
		1283	? bless \$cb, "AnyEvent::Util::postdetect"
		1284	: ()
		1285	}
		1286
		1287	sub AnyEvent::Util::postdetect::DESTROY {
		1288	@post_detect = grep $_ != ${$_[0]}, @post_detect;
		1289	}
		1290
		1291	our $POSTPONE_W;
		1292	our @POSTPONE;
		1293
		1294	sub _postpone_exec {
		1295	undef $POSTPONE_W;
		1296
		1297	&{ shift @POSTPONE }
		1298	while @POSTPONE;
		1299	}
		1300
		1301	sub postpone(&) {
		1302	push @POSTPONE, shift;
		1303
		1304	$POSTPONE_W ||= AE::timer (0, 0, \&_postpone_exec);
		1305
		1306	()
		1307	}
		1308
		1309	sub log($$;@) {
		1310	# only load the big bloated module when we actually are about to log something
		1311	if ($_[0] <= $VERBOSE) { # also catches non-numeric levels(!)
		1312	require AnyEvent::Log;
		1313	# AnyEvent::Log overwrites this function
		1314	goto &log;
		1315	}
		1316
		1317	0 # not logged
		1318	}
		1319
		1320	if (length $ENV{PERL_ANYEVENT_LOG}) {
		1321	require AnyEvent::Log; # AnyEvent::Log does the thing for us
		1322	}
		1323
1154	my @models = (	1324	our @models = (
1155	[EV:: => AnyEvent::Impl::EV:: , 1],	1325	[EV:: => AnyEvent::Impl::EV:: , 1],
1156	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl:: , 1],	1326	[AnyEvent::Loop:: => AnyEvent::Impl::Perl:: , 1],
1157	# everything below here will not (normally) be autoprobed	1327	# everything below here will not (normally) be autoprobed
1158	# as the pureperl backend should work everywhere	1328	# as the pure perl backend should work everywhere
1159	# and is usually faster	1329	# and is usually faster
1160	[Event:: => AnyEvent::Impl::Event::, 1],	1330	[Event:: => AnyEvent::Impl::Event::, 1],
1161	[Glib:: => AnyEvent::Impl::Glib:: , 1], # becomes extremely slow with many watchers	1331	[Glib:: => AnyEvent::Impl::Glib:: , 1], # becomes extremely slow with many watchers
1162	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy	1332	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
1163	[Irssi:: => AnyEvent::Impl::Irssi::], # Irssi has a bogus "Event" package	1333	[Irssi:: => AnyEvent::Impl::Irssi::], # Irssi has a bogus "Event" package
1164	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles	1334	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
1165	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program	1335	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program
1166	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza	1336	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
1167	[Wx:: => AnyEvent::Impl::POE::],	1337	[Wx:: => AnyEvent::Impl::POE::],
1168	[Prima:: => AnyEvent::Impl::POE::],	1338	[Prima:: => AnyEvent::Impl::POE::],
1169	# IO::Async is just too broken - we would need workarounds for its	1339	[IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # a bitch to autodetect
1170	# byzantine signal and broken child handling, among others.	1340	[Cocoa::EventLoop:: => AnyEvent::Impl::Cocoa::],
1171	# IO::Async is rather hard to detect, as it doesn't have any	1341	[FLTK:: => AnyEvent::Impl::FLTK::],
1172	# obvious default class.
1173	[IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program
1174	[IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program
1175	[IO::Async::Notifier:: => AnyEvent::Impl::IOAsync::], # requires special main program
1176	[AnyEvent::Impl::IOAsync:: => AnyEvent::Impl::IOAsync::], # requires special main program
1177	);	1342	);
1178		1343
1179	our %method = map +($_ => 1),	1344	our @isa_hook;
		1345
		1346	sub _isa_set {
		1347	my @pkg = ("AnyEvent", (map $_->[0], grep defined, @isa_hook), $MODEL);
		1348
		1349	@{"$pkg[$_-1]::ISA"} = $pkg[$_]
		1350	for 1 .. $#pkg;
		1351
		1352	grep $_ && $_->[1], @isa_hook
		1353	and AE::_reset ();
		1354	}
		1355
		1356	# used for hooking AnyEvent::Strict and AnyEvent::Debug::Wrap into the class hierarchy
		1357	sub _isa_hook($$;$) {
		1358	my ($i, $pkg, $reset_ae) = @_;
		1359
		1360	$isa_hook[$i] = $pkg ? [$pkg, $reset_ae] : undef;
		1361
		1362	_isa_set;
		1363	}
		1364
		1365	# all autoloaded methods reserve the complete glob, not just the method slot.
		1366	# due to bugs in perls method cache implementation.
1180	qw(io timer time now now_update signal child idle condvar one_event DESTROY);	1367	our @methods = qw(io timer time now now_update signal child idle condvar);
1181		1368
1182	our @post_detect;
1183
1184	sub post_detect(&) {	1369	sub detect() {
1185	my ($cb) = @_;	1370	return $MODEL if $MODEL; # some programs keep references to detect
1186		1371
1187	if ($MODEL) {	1372	local $!; # for good measure
1188	$cb->();	1373	local $SIG{__DIE__}; # we use eval
1189		1374
1190	undef	1375	# free some memory
		1376	*detect = sub () { $MODEL };
		1377	# undef &func doesn't correctly update the method cache. grmbl.
		1378	# so we delete the whole glob. grmbl.
		1379	# otoh, perl doesn't let me undef an active usb, but it lets me free
		1380	# a glob with an active sub. hrm. i hope it works, but perl is
		1381	# usually buggy in this department. sigh.
		1382	delete @{"AnyEvent::"}{@methods};
		1383	undef @methods;
		1384
		1385	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z0-9:]+)$/) {
		1386	my $model = $1;
		1387	$model = "AnyEvent::Impl::$model" unless $model =~ s/::$//;
		1388	if (eval "require $model") {
		1389	AnyEvent::log 7 => "loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.";
		1390	$MODEL = $model;
1191	} else {	1391	} else {
1192	push @post_detect, $cb;	1392	AnyEvent::log 5 => "unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@";
1193		1393	}
1194	defined wantarray
1195	? bless \$cb, "AnyEvent::Util::postdetect"
1196	: ()
1197	}	1394	}
1198	}
1199		1395
1200	sub AnyEvent::Util::postdetect::DESTROY {	1396	# check for already loaded models
1201	@post_detect = grep $_ != ${$_[0]}, @post_detect;
1202	}
1203
1204	sub detect() {
1205	unless ($MODEL) {	1397	unless ($MODEL) {
1206	local $SIG{__DIE__};	1398	for (@REGISTRY, @models) {
1207		1399	my ($package, $model) = @$_;
1208	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {	1400	if (${"$package\::VERSION"} > 0) {
1209	my $model = "AnyEvent::Impl::$1";
1210	if (eval "require $model") {	1401	if (eval "require $model") {
		1402	AnyEvent::log 7 => "autodetected model '$model', using it.";
1211	$MODEL = $model;	1403	$MODEL = $model;
1212	warn "AnyEvent: loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.\n" if $VERBOSE >= 2;	1404	last;
1213	} else {	1405	}
1214	warn "AnyEvent: unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@" if $VERBOSE;
1215	}	1406	}
1216	}	1407	}
1217		1408
1218	# check for already loaded models
1219	unless ($MODEL) {	1409	unless ($MODEL) {
		1410	# try to autoload a model
1220	for (@REGISTRY, @models) {	1411	for (@REGISTRY, @models) {
1221	my ($package, $model) = @$_;	1412	my ($package, $model, $autoload) = @$_;
		1413	if (
		1414	$autoload
		1415	and eval "require $package"
1222	if (${"$package\::VERSION"} > 0) {	1416	and ${"$package\::VERSION"} > 0
1223	if (eval "require $model") {	1417	and eval "require $model"
		1418	) {
		1419	AnyEvent::log 7 => "autoloaded model '$model', using it.";
1224	$MODEL = $model;	1420	$MODEL = $model;
1225	warn "AnyEvent: autodetected model '$model', using it.\n" if $VERBOSE >= 2;
1226	last;	1421	last;
1227	}
1228	}	1422	}
1229	}	1423	}
1230		1424
1231	unless ($MODEL) {
1232	# try to autoload a model
1233	for (@REGISTRY, @models) {
1234	my ($package, $model, $autoload) = @$_;
1235	if (
1236	$autoload
1237	and eval "require $package"
1238	and ${"$package\::VERSION"} > 0
1239	and eval "require $model"
1240	) {
1241	$MODEL = $model;
1242	warn "AnyEvent: autoloaded model '$model', using it.\n" if $VERBOSE >= 2;
1243	last;
1244	}
1245	}
1246
1247	$MODEL	1425	$MODEL
1248	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.\n";	1426	or die "AnyEvent: backend autodetection failed - did you properly install AnyEvent?";
1249	}
1250	}	1427	}
1251
1252	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
1253
1254	unshift @ISA, $MODEL;
1255
1256	require AnyEvent::Strict if $ENV{PERL_ANYEVENT_STRICT};
1257
1258	(shift @post_detect)->() while @post_detect;
1259	}	1428	}
1260		1429
		1430	# free memory only needed for probing
		1431	undef @models;
		1432	undef @REGISTRY;
		1433
		1434	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
		1435
		1436	# now nuke some methods that are overridden by the backend.
		1437	# SUPER usage is not allowed in these.
		1438	for (qw(time signal child idle)) {
		1439	undef &{"AnyEvent::Base::$_"}
		1440	if defined &{"$MODEL\::$_"};
		1441	}
		1442
		1443	_isa_set;
		1444
		1445	# we're officially open!
		1446
		1447	if ($ENV{PERL_ANYEVENT_STRICT}) {
		1448	require AnyEvent::Strict;
		1449	}
		1450
		1451	if ($ENV{PERL_ANYEVENT_DEBUG_WRAP}) {
		1452	require AnyEvent::Debug;
		1453	AnyEvent::Debug::wrap ($ENV{PERL_ANYEVENT_DEBUG_WRAP});
		1454	}
		1455
		1456	if (length $ENV{PERL_ANYEVENT_DEBUG_SHELL}) {
		1457	require AnyEvent::Socket;
		1458	require AnyEvent::Debug;
		1459
		1460	my $shell = $ENV{PERL_ANYEVENT_DEBUG_SHELL};
		1461	$shell =~ s/\$\$/$$/g;
		1462
		1463	my ($host, $service) = AnyEvent::Socket::parse_hostport ($shell);
		1464	$AnyEvent::Debug::SHELL = AnyEvent::Debug::shell ($host, $service);
		1465	}
		1466
		1467	# now the anyevent environment is set up as the user told us to, so
		1468	# call the actual user code - post detects
		1469
		1470	(shift @post_detect)->() while @post_detect;
		1471	undef @post_detect;
		1472
		1473	*post_detect = sub(&) {
		1474	shift->();
		1475
		1476	undef
		1477	};
		1478
1261	$MODEL	1479	$MODEL
1262	}	1480	}
1263		1481
1264	sub AUTOLOAD {	1482	for my $name (@methods) {
1265	(my $func = $AUTOLOAD) =~ s/.*://;	1483	*$name = sub {
1266		1484	detect;
1267	$method{$func}	1485	# we use goto because
1268	or Carp::croak "$func: not a valid method for AnyEvent objects";	1486	# a) it makes the thunk more transparent
1269		1487	# b) it allows us to delete the thunk later
1270	detect unless $MODEL;	1488	goto &{ UNIVERSAL::can AnyEvent => "SUPER::$name" }
1271		1489	};
1272	my $class = shift;
1273	$class->$func (@_);
1274	}	1490	}
1275		1491
1276	# utility function to dup a filehandle. this is used by many backends	1492	# utility function to dup a filehandle. this is used by many backends
1277	# to support binding more than one watcher per filehandle (they usually	1493	# to support binding more than one watcher per filehandle (they usually
1278	# allow only one watcher per fd, so we dup it to get a different one).	1494	# allow only one watcher per fd, so we dup it to get a different one).
…		…
1292		1508
1293	=head1 SIMPLIFIED AE API	1509	=head1 SIMPLIFIED AE API
1294		1510
1295	Starting with version 5.0, AnyEvent officially supports a second, much	1511	Starting with version 5.0, AnyEvent officially supports a second, much
1296	simpler, API that is designed to reduce the calling, typing and memory	1512	simpler, API that is designed to reduce the calling, typing and memory
1297	overhead.	1513	overhead by using function call syntax and a fixed number of parameters.
1298		1514
1299	See the L<AE> manpage for details.	1515	See the L<AE> manpage for details.
1300		1516
1301	=cut	1517	=cut
1302		1518
1303	package AE;	1519	package AE;
1304		1520
1305	our $VERSION = $AnyEvent::VERSION;	1521	our $VERSION = $AnyEvent::VERSION;
1306		1522
		1523	sub _reset() {
		1524	eval q{
		1525	# fall back to the main API by default - backends and AnyEvent::Base
		1526	# implementations can overwrite these.
		1527
1307	sub io($$$) {	1528	sub io($$$) {
1308	AnyEvent->io (fh => $_[0], poll => $_[1] ? "w" : "r", cb => $_[2])	1529	AnyEvent->io (fh => $_[0], poll => $_[1] ? "w" : "r", cb => $_[2])
1309	}	1530	}
1310		1531
1311	sub timer($$$) {	1532	sub timer($$$) {
1312	AnyEvent->timer (after => $_[0], interval => $_[1], cb => $_[2])	1533	AnyEvent->timer (after => $_[0], interval => $_[1], cb => $_[2])
1313	}	1534	}
1314		1535
1315	sub signal($$) {	1536	sub signal($$) {
1316	AnyEvent->signal (signal => $_[0], cb => $_[1])	1537	AnyEvent->signal (signal => $_[0], cb => $_[1])
1317	}	1538	}
1318		1539
1319	sub child($$) {	1540	sub child($$) {
1320	AnyEvent->child (pid => $_[0], cb => $_[1])	1541	AnyEvent->child (pid => $_[0], cb => $_[1])
1321	}	1542	}
1322		1543
1323	sub idle($) {	1544	sub idle($) {
1324	AnyEvent->idle (cb => $_[0])	1545	AnyEvent->idle (cb => $_[0]);
1325	}	1546	}
1326		1547
1327	sub cv(;&) {	1548	sub cv(;&) {
1328	AnyEvent->condvar (@_ ? (cb => $_[0]) : ())	1549	AnyEvent->condvar (@_ ? (cb => $_[0]) : ())
1329	}	1550	}
1330		1551
1331	sub now() {	1552	sub now() {
1332	AnyEvent->now	1553	AnyEvent->now
1333	}	1554	}
1334		1555
1335	sub now_update() {	1556	sub now_update() {
1336	AnyEvent->now_update	1557	AnyEvent->now_update
1337	}	1558	}
1338		1559
1339	sub time() {	1560	sub time() {
1340	AnyEvent->time	1561	AnyEvent->time
		1562	}
		1563
		1564	*postpone = \&AnyEvent::postpone;
		1565	*log = \&AnyEvent::log;
		1566	};
		1567	die if $@;
1341	}	1568	}
		1569
		1570	BEGIN { _reset }
1342		1571
1343	package AnyEvent::Base;	1572	package AnyEvent::Base;
1344		1573
1345	# default implementations for many methods	1574	# default implementations for many methods
1346		1575
1347	sub _time {	1576	sub time {
		1577	eval q{ # poor man's autoloading {}
1348	# probe for availability of Time::HiRes	1578	# probe for availability of Time::HiRes
1349	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {	1579	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {
1350	warn "AnyEvent: using Time::HiRes for sub-second timing accuracy.\n" if $VERBOSE >= 8;	1580	*time = sub { Time::HiRes::time () };
1351	*_time = \&Time::HiRes::time;	1581	*AE::time = \& Time::HiRes::time ;
		1582	*now = \&time;
		1583	AnyEvent::log 8 => "AnyEvent: using Time::HiRes for sub-second timing accuracy.";
1352	# if (eval "use POSIX (); (POSIX::times())...	1584	# if (eval "use POSIX (); (POSIX::times())...
1353	} else {	1585	} else {
		1586	*time = sub { CORE::time };
		1587	*AE::time = sub (){ CORE::time };
		1588	*now = \&time;
1354	warn "AnyEvent: using built-in time(), WARNING, no sub-second resolution!\n" if $VERBOSE;	1589	AnyEvent::log 3 => "using built-in time(), WARNING, no sub-second resolution!";
1355	*_time = sub { time }; # epic fail	1590	}
1356	}	1591	};
		1592	die if $@;
1357		1593
1358	&_time	1594	&time
1359	}	1595	}
1360		1596
1361	sub time { _time }	1597	*now = \&time;
1362	sub now { _time }
1363	sub now_update { }	1598	sub now_update { }
1364		1599
		1600	sub _poll {
		1601	Carp::croak "$AnyEvent::MODEL does not support blocking waits. Caught";
		1602	}
		1603
1365	# default implementation for ->condvar	1604	# default implementation for ->condvar
		1605	# in fact, the default should not be overwritten
1366		1606
1367	sub condvar {	1607	sub condvar {
		1608	eval q{ # poor man's autoloading {}
		1609	*condvar = sub {
1368	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"	1610	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"
		1611	};
		1612
		1613	*AE::cv = sub (;&) {
		1614	bless { @_ ? (_ae_cb => shift) : () }, "AnyEvent::CondVar"
		1615	};
		1616	};
		1617	die if $@;
		1618
		1619	&condvar
1369	}	1620	}
1370		1621
1371	# default implementation for ->signal	1622	# default implementation for ->signal
1372		1623
1373	our $HAVE_ASYNC_INTERRUPT;	1624	our $HAVE_ASYNC_INTERRUPT;
1374		1625
1375	sub _have_async_interrupt() {	1626	sub _have_async_interrupt() {
1376	$HAVE_ASYNC_INTERRUPT = 1*(!$ENV{PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT}	1627	$HAVE_ASYNC_INTERRUPT = 1*(!$ENV{PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT}
1377	&& eval "use Async::Interrupt 1.0 (); 1")	1628	&& eval "use Async::Interrupt 1.02 (); 1")
1378	unless defined $HAVE_ASYNC_INTERRUPT;	1629	unless defined $HAVE_ASYNC_INTERRUPT;
1379		1630
1380	$HAVE_ASYNC_INTERRUPT	1631	$HAVE_ASYNC_INTERRUPT
1381	}	1632	}
1382		1633
1383	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);	1634	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);
1384	our (%SIG_ASY, %SIG_ASY_W);	1635	our (%SIG_ASY, %SIG_ASY_W);
1385	our ($SIG_COUNT, $SIG_TW);	1636	our ($SIG_COUNT, $SIG_TW);
1386		1637
1387	sub _signal_exec {
1388	$HAVE_ASYNC_INTERRUPT
1389	? $SIGPIPE_R->drain
1390	: sysread $SIGPIPE_R, my $dummy, 9;
1391
1392	while (%SIG_EV) {
1393	for (keys %SIG_EV) {
1394	delete $SIG_EV{$_};
1395	$_->() for values %{ $SIG_CB{$_} || {} };
1396	}
1397	}
1398	}
1399
1400	# install a dummy wakeup watcher to reduce signal catching latency	1638	# install a dummy wakeup watcher to reduce signal catching latency
		1639	# used by Impls
1401	sub _sig_add() {	1640	sub _sig_add() {
1402	unless ($SIG_COUNT++) {	1641	unless ($SIG_COUNT++) {
1403	# try to align timer on a full-second boundary, if possible	1642	# try to align timer on a full-second boundary, if possible
1404	my $NOW = AE::now;	1643	my $NOW = AE::now;
1405		1644
…		…
1415	undef $SIG_TW	1654	undef $SIG_TW
1416	unless --$SIG_COUNT;	1655	unless --$SIG_COUNT;
1417	}	1656	}
1418		1657
1419	our $_sig_name_init; $_sig_name_init = sub {	1658	our $_sig_name_init; $_sig_name_init = sub {
1420	eval q{ # poor man's autoloading	1659	eval q{ # poor man's autoloading {}
1421	undef $_sig_name_init;	1660	undef $_sig_name_init;
1422		1661
1423	if (_have_async_interrupt) {	1662	if (_have_async_interrupt) {
1424	*sig2num = \&Async::Interrupt::sig2num;	1663	*sig2num = \&Async::Interrupt::sig2num;
1425	*sig2name = \&Async::Interrupt::sig2name;	1664	*sig2name = \&Async::Interrupt::sig2name;
…		…
1449		1688
1450	sub signal {	1689	sub signal {
1451	eval q{ # poor man's autoloading {}	1690	eval q{ # poor man's autoloading {}
1452	# probe for availability of Async::Interrupt	1691	# probe for availability of Async::Interrupt
1453	if (_have_async_interrupt) {	1692	if (_have_async_interrupt) {
1454	warn "AnyEvent: using Async::Interrupt for race-free signal handling.\n" if $VERBOSE >= 8;	1693	AnyEvent::log 8 => "using Async::Interrupt for race-free signal handling.";
1455		1694
1456	$SIGPIPE_R = new Async::Interrupt::EventPipe;	1695	$SIGPIPE_R = new Async::Interrupt::EventPipe;
1457	$SIG_IO = AE::io $SIGPIPE_R->fileno, 0, \&_signal_exec;	1696	$SIG_IO = AE::io $SIGPIPE_R->fileno, 0, \&_signal_exec;
1458		1697
1459	} else {	1698	} else {
1460	warn "AnyEvent: using emulated perl signal handling with latency timer.\n" if $VERBOSE >= 8;	1699	AnyEvent::log 8 => "using emulated perl signal handling with latency timer.";
1461
1462	require Fcntl;
1463		1700
1464	if (AnyEvent::WIN32) {	1701	if (AnyEvent::WIN32) {
1465	require AnyEvent::Util;	1702	require AnyEvent::Util;
1466		1703
1467	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();	1704	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
1468	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R, 1) if $SIGPIPE_R;	1705	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R, 1) if $SIGPIPE_R;
1469	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W, 1) if $SIGPIPE_W; # just in case	1706	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W, 1) if $SIGPIPE_W; # just in case
1470	} else {	1707	} else {
1471	pipe $SIGPIPE_R, $SIGPIPE_W;	1708	pipe $SIGPIPE_R, $SIGPIPE_W;
1472	fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R;	1709	fcntl $SIGPIPE_R, AnyEvent::F_SETFL, AnyEvent::O_NONBLOCK if $SIGPIPE_R;
1473	fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case	1710	fcntl $SIGPIPE_W, AnyEvent::F_SETFL, AnyEvent::O_NONBLOCK if $SIGPIPE_W; # just in case
1474		1711
1475	# not strictly required, as $^F is normally 2, but let's make sure...	1712	# not strictly required, as $^F is normally 2, but let's make sure...
1476	fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;	1713	fcntl $SIGPIPE_R, AnyEvent::F_SETFD, AnyEvent::FD_CLOEXEC;
1477	fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;	1714	fcntl $SIGPIPE_W, AnyEvent::F_SETFD, AnyEvent::FD_CLOEXEC;
1478	}	1715	}
1479		1716
1480	$SIGPIPE_R	1717	$SIGPIPE_R
1481	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";	1718	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";
1482		1719
1483	$SIG_IO = AE::io $SIGPIPE_R, 0, \&_signal_exec;	1720	$SIG_IO = AE::io $SIGPIPE_R, 0, \&_signal_exec;
1484	}	1721	}
1485		1722
1486	*signal = sub {	1723	*signal = $HAVE_ASYNC_INTERRUPT
		1724	? sub {
1487	my (undef, %arg) = @_;	1725	my (undef, %arg) = @_;
1488		1726
1489	my $signal = uc $arg{signal}
1490	or Carp::croak "required option 'signal' is missing";
1491
1492	if ($HAVE_ASYNC_INTERRUPT) {
1493	# async::interrupt	1727	# async::interrupt
1494
1495	$signal = sig2num $signal;	1728	my $signal = sig2num $arg{signal};
1496	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};	1729	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
1497		1730
1498	$SIG_ASY{$signal} ||= new Async::Interrupt	1731	$SIG_ASY{$signal} ||= new Async::Interrupt
1499	cb => sub { undef $SIG_EV{$signal} },	1732	cb => sub { undef $SIG_EV{$signal} },
1500	signal => $signal,	1733	signal => $signal,
1501	pipe => [$SIGPIPE_R->filenos],	1734	pipe => [$SIGPIPE_R->filenos],
1502	pipe_autodrain => 0,	1735	pipe_autodrain => 0,
1503	;	1736	;
1504		1737
1505	} else {	1738	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
		1739	}
		1740	: sub {
		1741	my (undef, %arg) = @_;
		1742
1506	# pure perl	1743	# pure perl
1507
1508	# AE::Util has been loaded in signal
1509	$signal = sig2name $signal;	1744	my $signal = sig2name $arg{signal};
1510	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};	1745	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
1511		1746
1512	$SIG{$signal} ||= sub {	1747	$SIG{$signal} ||= sub {
1513	local $!;	1748	local $!;
1514	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;	1749	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;
1515	undef $SIG_EV{$signal};	1750	undef $SIG_EV{$signal};
1516	};	1751	};
1517		1752
1518	# can't do signal processing without introducing races in pure perl,	1753	# can't do signal processing without introducing races in pure perl,
1519	# so limit the signal latency.	1754	# so limit the signal latency.
1520	_sig_add;	1755	_sig_add;
1521	}
1522		1756
1523	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"	1757	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
		1758	}
1524	};	1759	;
1525		1760
1526	*AnyEvent::Base::signal::DESTROY = sub {	1761	*AnyEvent::Base::signal::DESTROY = sub {
1527	my ($signal, $cb) = @{$_[0]};	1762	my ($signal, $cb) = @{$_[0]};
1528		1763
1529	_sig_del;	1764	_sig_del;
…		…
1536	# print weird messages, or just unconditionally exit	1771	# print weird messages, or just unconditionally exit
1537	# instead of getting the default action.	1772	# instead of getting the default action.
1538	undef $SIG{$signal}	1773	undef $SIG{$signal}
1539	unless keys %{ $SIG_CB{$signal} };	1774	unless keys %{ $SIG_CB{$signal} };
1540	};	1775	};
		1776
		1777	*_signal_exec = sub {
		1778	$HAVE_ASYNC_INTERRUPT
		1779	? $SIGPIPE_R->drain
		1780	: sysread $SIGPIPE_R, (my $dummy), 9;
		1781
		1782	while (%SIG_EV) {
		1783	for (keys %SIG_EV) {
		1784	delete $SIG_EV{$_};
		1785	&$_ for values %{ $SIG_CB{$_} || {} };
		1786	}
		1787	}
		1788	};
1541	};	1789	};
1542	die if $@;	1790	die if $@;
		1791
1543	&signal	1792	&signal
1544	}	1793	}
1545		1794
1546	# default implementation for ->child	1795	# default implementation for ->child
1547		1796
1548	our %PID_CB;	1797	our %PID_CB;
1549	our $CHLD_W;	1798	our $CHLD_W;
1550	our $CHLD_DELAY_W;	1799	our $CHLD_DELAY_W;
1551	our $WNOHANG;
1552		1800
		1801	# used by many Impl's
1553	sub _emit_childstatus($$) {	1802	sub _emit_childstatus($$) {
1554	my (undef, $rpid, $rstatus) = @_;	1803	my (undef, $rpid, $rstatus) = @_;
1555		1804
1556	$_->($rpid, $rstatus)	1805	$_->($rpid, $rstatus)
1557	for values %{ $PID_CB{$rpid} || {} },	1806	for values %{ $PID_CB{$rpid} || {} },
1558	values %{ $PID_CB{0} || {} };	1807	values %{ $PID_CB{0} || {} };
1559	}	1808	}
1560		1809
1561	sub _sigchld {
1562	my $pid;
1563
1564	AnyEvent->_emit_childstatus ($pid, $?)
1565	while ($pid = waitpid -1, $WNOHANG) > 0;
1566	}
1567
1568	sub child {	1810	sub child {
		1811	eval q{ # poor man's autoloading {}
		1812	*_sigchld = sub {
		1813	my $pid;
		1814
		1815	AnyEvent->_emit_childstatus ($pid, $?)
		1816	while ($pid = waitpid -1, WNOHANG) > 0;
		1817	};
		1818
		1819	*child = sub {
1569	my (undef, %arg) = @_;	1820	my (undef, %arg) = @_;
1570		1821
1571	defined (my $pid = $arg{pid} + 0)	1822	my $pid = $arg{pid};
1572	or Carp::croak "required option 'pid' is missing";	1823	my $cb = $arg{cb};
1573		1824
1574	$PID_CB{$pid}{$arg{cb}} = $arg{cb};	1825	$PID_CB{$pid}{$cb+0} = $cb;
1575		1826
1576	# WNOHANG is almost cetrainly 1 everywhere
1577	$WNOHANG ||= $^O =~ /^(?:openbsd|netbsd|linux|freebsd|cygwin|MSWin32)$/
1578	? 1
1579	: eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1;
1580
1581	unless ($CHLD_W) {	1827	unless ($CHLD_W) {
1582	$CHLD_W = AE::signal CHLD => \&_sigchld;	1828	$CHLD_W = AE::signal CHLD => \&_sigchld;
1583	# child could be a zombie already, so make at least one round	1829	# child could be a zombie already, so make at least one round
1584	&_sigchld;	1830	&_sigchld;
1585	}	1831	}
1586		1832
1587	bless [$pid, $arg{cb}], "AnyEvent::Base::child"	1833	bless [$pid, $cb+0], "AnyEvent::Base::child"
1588	}	1834	};
1589		1835
1590	sub AnyEvent::Base::child::DESTROY {	1836	*AnyEvent::Base::child::DESTROY = sub {
1591	my ($pid, $cb) = @{$_[0]};	1837	my ($pid, $icb) = @{$_[0]};
1592		1838
1593	delete $PID_CB{$pid}{$cb};	1839	delete $PID_CB{$pid}{$icb};
1594	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };	1840	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };
1595		1841
1596	undef $CHLD_W unless keys %PID_CB;	1842	undef $CHLD_W unless keys %PID_CB;
		1843	};
		1844	};
		1845	die if $@;
		1846
		1847	&child
1597	}	1848	}
1598		1849
1599	# idle emulation is done by simply using a timer, regardless	1850	# idle emulation is done by simply using a timer, regardless
1600	# of whether the process is idle or not, and not letting	1851	# of whether the process is idle or not, and not letting
1601	# the callback use more than 50% of the time.	1852	# the callback use more than 50% of the time.
1602	sub idle {	1853	sub idle {
		1854	eval q{ # poor man's autoloading {}
		1855	*idle = sub {
1603	my (undef, %arg) = @_;	1856	my (undef, %arg) = @_;
1604		1857
1605	my ($cb, $w, $rcb) = $arg{cb};	1858	my ($cb, $w, $rcb) = $arg{cb};
1606		1859
1607	$rcb = sub {	1860	$rcb = sub {
1608	if ($cb) {	1861	if ($cb) {
1609	$w = _time;	1862	$w = AE::time;
1610	&$cb;	1863	&$cb;
1611	$w = _time - $w;	1864	$w = AE::time - $w;
1612		1865
1613	# never use more then 50% of the time for the idle watcher,	1866	# never use more then 50% of the time for the idle watcher,
1614	# within some limits	1867	# within some limits
1615	$w = 0.0001 if $w < 0.0001;	1868	$w = 0.0001 if $w < 0.0001;
1616	$w = 5 if $w > 5;	1869	$w = 5 if $w > 5;
1617		1870
1618	$w = AE::timer $w, 0, $rcb;	1871	$w = AE::timer $w, 0, $rcb;
1619	} else {	1872	} else {
1620	# clean up...	1873	# clean up...
1621	undef $w;	1874	undef $w;
1622	undef $rcb;	1875	undef $rcb;
		1876	}
		1877	};
		1878
		1879	$w = AE::timer 0.05, 0, $rcb;
		1880
		1881	bless \\$cb, "AnyEvent::Base::idle"
1623	}	1882	};
		1883
		1884	*AnyEvent::Base::idle::DESTROY = sub {
		1885	undef $${$_[0]};
		1886	};
1624	};	1887	};
		1888	die if $@;
1625		1889
1626	$w = AE::timer 0.05, 0, $rcb;	1890	&idle
1627
1628	bless \\$cb, "AnyEvent::Base::idle"
1629	}
1630
1631	sub AnyEvent::Base::idle::DESTROY {
1632	undef $${$_[0]};
1633	}	1891	}
1634		1892
1635	package AnyEvent::CondVar;	1893	package AnyEvent::CondVar;
1636		1894
1637	our @ISA = AnyEvent::CondVar::Base::;	1895	our @ISA = AnyEvent::CondVar::Base::;
		1896
		1897	# only to be used for subclassing
		1898	sub new {
		1899	my $class = shift;
		1900	bless AnyEvent->condvar (@_), $class
		1901	}
1638		1902
1639	package AnyEvent::CondVar::Base;	1903	package AnyEvent::CondVar::Base;
1640		1904
1641	#use overload	1905	#use overload
1642	# '&{}' => sub { my $self = shift; sub { $self->send (@_) } },	1906	# '&{}' => sub { my $self = shift; sub { $self->send (@_) } },
…		…
1652		1916
1653	sub _send {	1917	sub _send {
1654	# nop	1918	# nop
1655	}	1919	}
1656		1920
		1921	sub _wait {
		1922	AnyEvent->_poll until $_[0]{_ae_sent};
		1923	}
		1924
1657	sub send {	1925	sub send {
1658	my $cv = shift;	1926	my $cv = shift;
1659	$cv->{_ae_sent} = [@_];	1927	$cv->{_ae_sent} = [@_];
1660	(delete $cv->{_ae_cb})->($cv) if $cv->{_ae_cb};	1928	(delete $cv->{_ae_cb})->($cv) if $cv->{_ae_cb};
1661	$cv->_send;	1929	$cv->_send;
…		…
1668		1936
1669	sub ready {	1937	sub ready {
1670	$_[0]{_ae_sent}	1938	$_[0]{_ae_sent}
1671	}	1939	}
1672		1940
1673	sub _wait {
1674	$WAITING
1675	and !$_[0]{_ae_sent}
1676	and Carp::croak "AnyEvent::CondVar: recursive blocking wait detected";
1677
1678	local $WAITING = 1;
1679	AnyEvent->one_event while !$_[0]{_ae_sent};
1680	}
1681
1682	sub recv {	1941	sub recv {
		1942	unless ($_[0]{_ae_sent}) {
		1943	$WAITING
		1944	and Carp::croak "AnyEvent::CondVar: recursive blocking wait attempted";
		1945
		1946	local $WAITING = 1;
1683	$_[0]->_wait;	1947	$_[0]->_wait;
		1948	}
1684		1949
1685	Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak};	1950	$_[0]{_ae_croak}
1686	wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0]	1951	and Carp::croak $_[0]{_ae_croak};
		1952
		1953	wantarray
		1954	? @{ $_[0]{_ae_sent} }
		1955	: $_[0]{_ae_sent}[0]
1687	}	1956	}
1688		1957
1689	sub cb {	1958	sub cb {
1690	my $cv = shift;	1959	my $cv = shift;
1691		1960
…		…
1707	&{ $_[0]{_ae_end_cb} || sub { $_[0]->send } };	1976	&{ $_[0]{_ae_end_cb} || sub { $_[0]->send } };
1708	}	1977	}
1709		1978
1710	# undocumented/compatibility with pre-3.4	1979	# undocumented/compatibility with pre-3.4
1711	*broadcast = \&send;	1980	*broadcast = \&send;
1712	*wait = \&_wait;	1981	*wait = \&recv;
1713		1982
1714	=head1 ERROR AND EXCEPTION HANDLING	1983	=head1 ERROR AND EXCEPTION HANDLING
1715		1984
1716	In general, AnyEvent does not do any error handling - it relies on the	1985	In general, AnyEvent does not do any error handling - it relies on the
1717	caller to do that if required. The L<AnyEvent::Strict> module (see also	1986	caller to do that if required. The L<AnyEvent::Strict> module (see also
…		…
1729	$Event/EV::DIED->() >>, L<Glib> uses C<< install_exception_handler >> and	1998	$Event/EV::DIED->() >>, L<Glib> uses C<< install_exception_handler >> and
1730	so on.	1999	so on.
1731		2000
1732	=head1 ENVIRONMENT VARIABLES	2001	=head1 ENVIRONMENT VARIABLES
1733		2002
1734	The following environment variables are used by this module or its	2003	AnyEvent supports a number of environment variables that tune the
1735	submodules.	2004	runtime behaviour. They are usually evaluated when AnyEvent is
		2005	loaded, initialised, or a submodule that uses them is loaded. Many of
		2006	them also cause AnyEvent to load additional modules - for example,
		2007	C<PERL_ANYEVENT_DEBUG_WRAP> causes the L<AnyEvent::Debug> module to be
		2008	loaded.
1736		2009
1737	Note that AnyEvent will remove I<all> environment variables starting with	2010	All the environment variables documented here start with
1738	C<PERL_ANYEVENT_> from C<%ENV> when it is loaded while taint mode is	2011	C<PERL_ANYEVENT_>, which is what AnyEvent considers its own
1739	enabled.	2012	namespace. Other modules are encouraged (but by no means required) to use
		2013	C<PERL_ANYEVENT_SUBMODULE> if they have registered the AnyEvent::Submodule
		2014	namespace on CPAN, for any submodule. For example, L<AnyEvent::HTTP> could
		2015	be expected to use C<PERL_ANYEVENT_HTTP_PROXY> (it should not access env
		2016	variables starting with C<AE_>, see below).
		2017
		2018	All variables can also be set via the C<AE_> prefix, that is, instead
		2019	of setting C<PERL_ANYEVENT_VERBOSE> you can also set C<AE_VERBOSE>. In
		2020	case there is a clash btween anyevent and another program that uses
		2021	C<AE_something> you can set the corresponding C<PERL_ANYEVENT_something>
		2022	variable to the empty string, as those variables take precedence.
		2023
		2024	When AnyEvent is first loaded, it copies all C<AE_xxx> env variables
		2025	to their C<PERL_ANYEVENT_xxx> counterpart unless that variable already
		2026	exists. If taint mode is on, then AnyEvent will remove I<all> environment
		2027	variables starting with C<PERL_ANYEVENT_> from C<%ENV> (or replace them
		2028	with C<undef> or the empty string, if the corresaponding C<AE_> variable
		2029	is set).
		2030
		2031	The exact algorithm is currently:
		2032
		2033	1. if taint mode enabled, delete all PERL_ANYEVENT_xyz variables from %ENV
		2034	2. copy over AE_xyz to PERL_ANYEVENT_xyz unless the latter alraedy exists
		2035	3. if taint mode enabled, set all PERL_ANYEVENT_xyz variables to undef.
		2036
		2037	This ensures that child processes will not see the C<AE_> variables.
		2038
		2039	The following environment variables are currently known to AnyEvent:
1740		2040
1741	=over 4	2041	=over 4
1742		2042
1743	=item C<PERL_ANYEVENT_VERBOSE>	2043	=item C<PERL_ANYEVENT_VERBOSE>
1744		2044
1745	By default, AnyEvent will be completely silent except in fatal	2045	By default, AnyEvent will be completely silent except in fatal
1746	conditions. You can set this environment variable to make AnyEvent more	2046	conditions. You can set this environment variable to make AnyEvent more
1747	talkative.	2047	talkative. If you want to do more than just set the global logging level
		2048	you should have a look at C<PERL_ANYEVENT_LOG>, which allows much more
		2049	complex specifications.
1748		2050
1749	When set to C<1> or higher, causes AnyEvent to warn about unexpected	2051	When set to C<5> or higher (warn), causes AnyEvent to warn about unexpected
1750	conditions, such as not being able to load the event model specified by	2052	conditions, such as not being able to load the event model specified by
1751	C<PERL_ANYEVENT_MODEL>.	2053	C<PERL_ANYEVENT_MODEL>, or a guard callback throwing an exception - this
		2054	is the minimum recommended level.
1752		2055
1753	When set to C<2> or higher, cause AnyEvent to report to STDERR which event	2056	When set to C<7> or higher (info), cause AnyEvent to report which event model it
1754	model it chooses.	2057	chooses.
1755		2058
1756	When set to C<8> or higher, then AnyEvent will report extra information on	2059	When set to C<8> or higher (debug), then AnyEvent will report extra information on
1757	which optional modules it loads and how it implements certain features.	2060	which optional modules it loads and how it implements certain features.
		2061
		2062	=item C<PERL_ANYEVENT_LOG>
		2063
		2064	Accepts rather complex logging specifications. For example, you could log
		2065	all C<debug> messages of some module to stderr, warnings and above to
		2066	stderr, and errors and above to syslog, with:
		2067
		2068	PERL_ANYEVENT_LOG=Some::Module=debug,+log:filter=warn,+%syslog:%syslog=error,syslog
		2069
		2070	For the rather extensive details, see L<AnyEvent::Log>.
		2071
		2072	This variable is evaluated when AnyEvent (or L<AnyEvent::Log>) is loaded,
		2073	so will take effect even before AnyEvent has initialised itself.
		2074
		2075	Note that specifying this environment variable causes the L<AnyEvent::Log>
		2076	module to be loaded, while C<PERL_ANYEVENT_VERBOSE> does not, so only
		2077	using the latter saves a few hundred kB of memory until the first message
		2078	is being logged.
1758		2079
1759	=item C<PERL_ANYEVENT_STRICT>	2080	=item C<PERL_ANYEVENT_STRICT>
1760		2081
1761	AnyEvent does not do much argument checking by default, as thorough	2082	AnyEvent does not do much argument checking by default, as thorough
1762	argument checking is very costly. Setting this variable to a true value	2083	argument checking is very costly. Setting this variable to a true value
…		…
1764	check the arguments passed to most method calls. If it finds any problems,	2085	check the arguments passed to most method calls. If it finds any problems,
1765	it will croak.	2086	it will croak.
1766		2087
1767	In other words, enables "strict" mode.	2088	In other words, enables "strict" mode.
1768		2089
1769	Unlike C<use strict> (or it's modern cousin, C<< use L<common::sense>	2090	Unlike C<use strict> (or its modern cousin, C<< use L<common::sense>
1770	>>, it is definitely recommended to keep it off in production. Keeping	2091	>>, it is definitely recommended to keep it off in production. Keeping
1771	C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs	2092	C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs
1772	can be very useful, however.	2093	can be very useful, however.
1773		2094
		2095	=item C<PERL_ANYEVENT_DEBUG_SHELL>
		2096
		2097	If this env variable is set, then its contents will be interpreted by
		2098	C<AnyEvent::Socket::parse_hostport> (after replacing every occurance of
		2099	C<$$> by the process pid) and an C<AnyEvent::Debug::shell> is bound on
		2100	that port. The shell object is saved in C<$AnyEvent::Debug::SHELL>.
		2101
		2102	This happens when the first watcher is created.
		2103
		2104	For example, to bind a debug shell on a unix domain socket in
		2105	F<< /tmp/debug<pid>.sock >>, you could use this:
		2106
		2107	PERL_ANYEVENT_DEBUG_SHELL=/tmp/debug\$\$.sock perlprog
		2108
		2109	Note that creating sockets in F</tmp> is very unsafe on multiuser
		2110	systems.
		2111
		2112	=item C<PERL_ANYEVENT_DEBUG_WRAP>
		2113
		2114	Can be set to C<0>, C<1> or C<2> and enables wrapping of all watchers for
		2115	debugging purposes. See C<AnyEvent::Debug::wrap> for details.
		2116
1774	=item C<PERL_ANYEVENT_MODEL>	2117	=item C<PERL_ANYEVENT_MODEL>
1775		2118
1776	This can be used to specify the event model to be used by AnyEvent, before	2119	This can be used to specify the event model to be used by AnyEvent, before
1777	auto detection and -probing kicks in. It must be a string consisting	2120	auto detection and -probing kicks in.
1778	entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended	2121
		2122	It normally is a string consisting entirely of ASCII letters (e.g. C<EV>
		2123	or C<IOAsync>). The string C<AnyEvent::Impl::> gets prepended and the
1779	and the resulting module name is loaded and if the load was successful,	2124	resulting module name is loaded and - if the load was successful - used as
1780	used as event model. If it fails to load AnyEvent will proceed with	2125	event model backend. If it fails to load then AnyEvent will proceed with
1781	auto detection and -probing.	2126	auto detection and -probing.
1782		2127
1783	This functionality might change in future versions.	2128	If the string ends with C<::> instead (e.g. C<AnyEvent::Impl::EV::>) then
		2129	nothing gets prepended and the module name is used as-is (hint: C<::> at
		2130	the end of a string designates a module name and quotes it appropriately).
1784		2131
1785	For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you	2132	For example, to force the pure perl model (L<AnyEvent::Loop::Perl>) you
1786	could start your program like this:	2133	could start your program like this:
1787		2134
1788	PERL_ANYEVENT_MODEL=Perl perl ...	2135	PERL_ANYEVENT_MODEL=Perl perl ...
1789		2136
1790	=item C<PERL_ANYEVENT_PROTOCOLS>	2137	=item C<PERL_ANYEVENT_PROTOCOLS>
…		…
1806	but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4>	2153	but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4>
1807	- only support IPv4, never try to resolve or contact IPv6	2154	- only support IPv4, never try to resolve or contact IPv6
1808	addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or	2155	addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or
1809	IPv6, but prefer IPv6 over IPv4.	2156	IPv6, but prefer IPv6 over IPv4.
1810		2157
		2158	=item C<PERL_ANYEVENT_HOSTS>
		2159
		2160	This variable, if specified, overrides the F</etc/hosts> file used by
		2161	L<AnyEvent::Socket>C<::resolve_sockaddr>, i.e. hosts aliases will be read
		2162	from that file instead.
		2163
1811	=item C<PERL_ANYEVENT_EDNS0>	2164	=item C<PERL_ANYEVENT_EDNS0>
1812		2165
1813	Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension	2166	Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension for
1814	for DNS. This extension is generally useful to reduce DNS traffic, but	2167	DNS. This extension is generally useful to reduce DNS traffic, especially
1815	some (broken) firewalls drop such DNS packets, which is why it is off by	2168	when DNSSEC is involved, but some (broken) firewalls drop such DNS
1816	default.	2169	packets, which is why it is off by default.
1817		2170
1818	Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce	2171	Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce
1819	EDNS0 in its DNS requests.	2172	EDNS0 in its DNS requests.
1820		2173
1821	=item C<PERL_ANYEVENT_MAX_FORKS>	2174	=item C<PERL_ANYEVENT_MAX_FORKS>
…		…
1829	resolver - this is the maximum number of parallel DNS requests that are	2182	resolver - this is the maximum number of parallel DNS requests that are
1830	sent to the DNS server.	2183	sent to the DNS server.
1831		2184
1832	=item C<PERL_ANYEVENT_RESOLV_CONF>	2185	=item C<PERL_ANYEVENT_RESOLV_CONF>
1833		2186
1834	The file to use instead of F</etc/resolv.conf> (or OS-specific	2187	The absolute path to a F<resolv.conf>-style file to use instead of
1835	configuration) in the default resolver. When set to the empty string, no	2188	F</etc/resolv.conf> (or the OS-specific configuration) in the default
1836	default config will be used.	2189	resolver, or the empty string to select the default configuration.
1837		2190
1838	=item C<PERL_ANYEVENT_CA_FILE>, C<PERL_ANYEVENT_CA_PATH>.	2191	=item C<PERL_ANYEVENT_CA_FILE>, C<PERL_ANYEVENT_CA_PATH>.
1839		2192
1840	When neither C<ca_file> nor C<ca_path> was specified during	2193	When neither C<ca_file> nor C<ca_path> was specified during
1841	L<AnyEvent::TLS> context creation, and either of these environment	2194	L<AnyEvent::TLS> context creation, and either of these environment
1842	variables exist, they will be used to specify CA certificate locations	2195	variables are nonempty, they will be used to specify CA certificate
1843	instead of a system-dependent default.	2196	locations instead of a system-dependent default.
1844		2197
1845	=item C<PERL_ANYEVENT_AVOID_GUARD> and C<PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT>	2198	=item C<PERL_ANYEVENT_AVOID_GUARD> and C<PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT>
1846		2199
1847	When these are set to C<1>, then the respective modules are not	2200	When these are set to C<1>, then the respective modules are not
1848	loaded. Mostly good for testing AnyEvent itself.	2201	loaded. Mostly good for testing AnyEvent itself.
…		…
1911	warn "read: $input\n"; # output what has been read	2264	warn "read: $input\n"; # output what has been read
1912	$cv->send if $input =~ /^q/i; # quit program if /^q/i	2265	$cv->send if $input =~ /^q/i; # quit program if /^q/i
1913	},	2266	},
1914	);	2267	);
1915		2268
1916	my $time_watcher; # can only be used once
1917
1918	sub new_timer {
1919	$timer = AnyEvent->timer (after => 1, cb => sub {	2269	my $time_watcher = AnyEvent->timer (after => 1, interval => 1, cb => sub {
1920	warn "timeout\n"; # print 'timeout' about every second	2270	warn "timeout\n"; # print 'timeout' at most every second
1921	&new_timer; # and restart the time
1922	});	2271	});
1923	}
1924
1925	new_timer; # create first timer
1926		2272
1927	$cv->recv; # wait until user enters /^q/i	2273	$cv->recv; # wait until user enters /^q/i
1928		2274
1929	=head1 REAL-WORLD EXAMPLE	2275	=head1 REAL-WORLD EXAMPLE
1930		2276
…		…
2003		2349
2004	The actual code goes further and collects all errors (C<die>s, exceptions)	2350	The actual code goes further and collects all errors (C<die>s, exceptions)
2005	that occurred during request processing. The C<result> method detects	2351	that occurred during request processing. The C<result> method detects
2006	whether an exception as thrown (it is stored inside the $txn object)	2352	whether an exception as thrown (it is stored inside the $txn object)
2007	and just throws the exception, which means connection errors and other	2353	and just throws the exception, which means connection errors and other
2008	problems get reported tot he code that tries to use the result, not in a	2354	problems get reported to the code that tries to use the result, not in a
2009	random callback.	2355	random callback.
2010		2356
2011	All of this enables the following usage styles:	2357	All of this enables the following usage styles:
2012		2358
2013	1. Blocking:	2359	1. Blocking:
…		…
2187	(even when used without AnyEvent), but most event loops have acceptable	2533	(even when used without AnyEvent), but most event loops have acceptable
2188	performance with or without AnyEvent.	2534	performance with or without AnyEvent.
2189		2535
2190	=item * The overhead AnyEvent adds is usually much smaller than the overhead of	2536	=item * The overhead AnyEvent adds is usually much smaller than the overhead of
2191	the actual event loop, only with extremely fast event loops such as EV	2537	the actual event loop, only with extremely fast event loops such as EV
2192	adds AnyEvent significant overhead.	2538	does AnyEvent add significant overhead.
2193		2539
2194	=item * You should avoid POE like the plague if you want performance or	2540	=item * You should avoid POE like the plague if you want performance or
2195	reasonable memory usage.	2541	reasonable memory usage.
2196		2542
2197	=back	2543	=back
…		…
2374	As you can see, the AnyEvent + EV combination even beats the	2720	As you can see, the AnyEvent + EV combination even beats the
2375	hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl	2721	hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl
2376	backend easily beats IO::Lambda and POE.	2722	backend easily beats IO::Lambda and POE.
2377		2723
2378	And even the 100% non-blocking version written using the high-level (and	2724	And even the 100% non-blocking version written using the high-level (and
2379	slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda by a	2725	slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda
2380	large margin, even though it does all of DNS, tcp-connect and socket I/O	2726	higher level ("unoptimised") abstractions by a large margin, even though
2381	in a non-blocking way.	2727	it does all of DNS, tcp-connect and socket I/O in a non-blocking way.
2382		2728
2383	The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and	2729	The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and
2384	F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are	2730	F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are
2385	part of the IO::lambda distribution and were used without any changes.	2731	part of the IO::Lambda distribution and were used without any changes.
2386		2732
2387		2733
2388	=head1 SIGNALS	2734	=head1 SIGNALS
2389		2735
2390	AnyEvent currently installs handlers for these signals:	2736	AnyEvent currently installs handlers for these signals:
…		…
2427	unless defined $SIG{PIPE};	2773	unless defined $SIG{PIPE};
2428		2774
2429	=head1 RECOMMENDED/OPTIONAL MODULES	2775	=head1 RECOMMENDED/OPTIONAL MODULES
2430		2776
2431	One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and	2777	One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and
2432	it's built-in modules) are required to use it.	2778	its built-in modules) are required to use it.
2433		2779
2434	That does not mean that AnyEvent won't take advantage of some additional	2780	That does not mean that AnyEvent won't take advantage of some additional
2435	modules if they are installed.	2781	modules if they are installed.
2436		2782
2437	This section epxlains which additional modules will be used, and how they	2783	This section explains which additional modules will be used, and how they
2438	affect AnyEvent's operetion.	2784	affect AnyEvent's operation.
2439		2785
2440	=over 4	2786	=over 4
2441		2787
2442	=item L<Async::Interrupt>	2788	=item L<Async::Interrupt>
2443		2789
…		…
2448	catch the signals) with some delay (default is 10 seconds, look for	2794	catch the signals) with some delay (default is 10 seconds, look for
2449	C<$AnyEvent::MAX_SIGNAL_LATENCY>).	2795	C<$AnyEvent::MAX_SIGNAL_LATENCY>).
2450		2796
2451	If this module is available, then it will be used to implement signal	2797	If this module is available, then it will be used to implement signal
2452	catching, which means that signals will not be delayed, and the event loop	2798	catching, which means that signals will not be delayed, and the event loop
2453	will not be interrupted regularly, which is more efficient (And good for	2799	will not be interrupted regularly, which is more efficient (and good for
2454	battery life on laptops).	2800	battery life on laptops).
2455		2801
2456	This affects not just the pure-perl event loop, but also other event loops	2802	This affects not just the pure-perl event loop, but also other event loops
2457	that have no signal handling on their own (e.g. Glib, Tk, Qt).	2803	that have no signal handling on their own (e.g. Glib, Tk, Qt).
2458		2804
…		…
2470	automatic timer adjustments even when no monotonic clock is available,	2816	automatic timer adjustments even when no monotonic clock is available,
2471	can take avdantage of advanced kernel interfaces such as C<epoll> and	2817	can take avdantage of advanced kernel interfaces such as C<epoll> and
2472	C<kqueue>, and is the fastest backend I<by far>. You can even embed	2818	C<kqueue>, and is the fastest backend I<by far>. You can even embed
2473	L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>).	2819	L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>).
2474		2820
		2821	If you only use backends that rely on another event loop (e.g. C<Tk>),
		2822	then this module will do nothing for you.
		2823
2475	=item L<Guard>	2824	=item L<Guard>
2476		2825
2477	The guard module, when used, will be used to implement	2826	The guard module, when used, will be used to implement
2478	C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a	2827	C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a
2479	lot less memory), but otherwise doesn't affect guard operation much. It is	2828	lot less memory), but otherwise doesn't affect guard operation much. It is
2480	purely used for performance.	2829	purely used for performance.
2481		2830
2482	=item L<JSON> and L<JSON::XS>	2831	=item L<JSON> and L<JSON::XS>
2483		2832
2484	This module is required when you want to read or write JSON data via	2833	One of these modules is required when you want to read or write JSON data
2485	L<AnyEvent::Handle>. It is also written in pure-perl, but can take	2834	via L<AnyEvent::Handle>. L<JSON> is also written in pure-perl, but can take
2486	advantage of the ultra-high-speed L<JSON::XS> module when it is installed.	2835	advantage of the ultra-high-speed L<JSON::XS> module when it is installed.
2487
2488	In fact, L<AnyEvent::Handle> will use L<JSON::XS> by default if it is
2489	installed.
2490		2836
2491	=item L<Net::SSLeay>	2837	=item L<Net::SSLeay>
2492		2838
2493	Implementing TLS/SSL in Perl is certainly interesting, but not very	2839	Implementing TLS/SSL in Perl is certainly interesting, but not very
2494	worthwhile: If this module is installed, then L<AnyEvent::Handle> (with	2840	worthwhile: If this module is installed, then L<AnyEvent::Handle> (with
2495	the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL.	2841	the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL.
2496		2842
2497	=item L<Time::HiRes>	2843	=item L<Time::HiRes>
2498		2844
2499	This module is part of perl since release 5.008. It will be used when the	2845	This module is part of perl since release 5.008. It will be used when the
2500	chosen event library does not come with a timing source on it's own. The	2846	chosen event library does not come with a timing source of its own. The
2501	pure-perl event loop (L<AnyEvent::Impl::Perl>) will additionally use it to	2847	pure-perl event loop (L<AnyEvent::Loop>) will additionally load it to
2502	try to use a monotonic clock for timing stability.	2848	try to use a monotonic clock for timing stability.
2503		2849
2504	=back	2850	=back
2505		2851
2506		2852
2507	=head1 FORK	2853	=head1 FORK
2508		2854
2509	Most event libraries are not fork-safe. The ones who are usually are	2855	Most event libraries are not fork-safe. The ones who are usually are
2510	because they rely on inefficient but fork-safe C<select> or C<poll>	2856	because they rely on inefficient but fork-safe C<select> or C<poll> calls
2511	calls. Only L<EV> is fully fork-aware.	2857	- higher performance APIs such as BSD's kqueue or the dreaded Linux epoll
		2858	are usually badly thought-out hacks that are incompatible with fork in
		2859	one way or another. Only L<EV> is fully fork-aware and ensures that you
		2860	continue event-processing in both parent and child (or both, if you know
		2861	what you are doing).
		2862
		2863	This means that, in general, you cannot fork and do event processing in
		2864	the child if the event library was initialised before the fork (which
		2865	usually happens when the first AnyEvent watcher is created, or the library
		2866	is loaded).
2512		2867
2513	If you have to fork, you must either do so I<before> creating your first	2868	If you have to fork, you must either do so I<before> creating your first
2514	watcher OR you must not use AnyEvent at all in the child OR you must do	2869	watcher OR you must not use AnyEvent at all in the child OR you must do
2515	something completely out of the scope of AnyEvent.	2870	something completely out of the scope of AnyEvent.
		2871
		2872	The problem of doing event processing in the parent I<and> the child
		2873	is much more complicated: even for backends that I<are> fork-aware or
		2874	fork-safe, their behaviour is not usually what you want: fork clones all
		2875	watchers, that means all timers, I/O watchers etc. are active in both
		2876	parent and child, which is almost never what you want. USing C<exec>
		2877	to start worker children from some kind of manage rprocess is usually
		2878	preferred, because it is much easier and cleaner, at the expense of having
		2879	to have another binary.
2516		2880
2517		2881
2518	=head1 SECURITY CONSIDERATIONS	2882	=head1 SECURITY CONSIDERATIONS
2519		2883
2520	AnyEvent can be forced to load any event model via	2884	AnyEvent can be forced to load any event model via
…		…
2550	pronounced).	2914	pronounced).
2551		2915
2552		2916
2553	=head1 SEE ALSO	2917	=head1 SEE ALSO
2554		2918
2555	Utility functions: L<AnyEvent::Util>.	2919	Tutorial/Introduction: L<AnyEvent::Intro>.
2556		2920
2557	Event modules: L<EV>, L<EV::Glib>, L<Glib::EV>, L<Event>, L<Glib::Event>,	2921	FAQ: L<AnyEvent::FAQ>.
2558	L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.	2922
		2923	Utility functions: L<AnyEvent::Util> (misc. grab-bag), L<AnyEvent::Log>
		2924	(simply logging).
		2925
		2926	Development/Debugging: L<AnyEvent::Strict> (stricter checking),
		2927	L<AnyEvent::Debug> (interactive shell, watcher tracing).
		2928
		2929	Supported event modules: L<AnyEvent::Loop>, L<EV>, L<EV::Glib>,
		2930	L<Glib::EV>, L<Event>, L<Glib::Event>, L<Glib>, L<Tk>, L<Event::Lib>,
		2931	L<Qt>, L<POE>, L<FLTK>.
2559		2932
2560	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,	2933	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,
2561	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,	2934	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,
2562	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,	2935	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,
2563	L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>, L<Anyevent::Impl::Irssi>.	2936	L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>, L<Anyevent::Impl::Irssi>,
		2937	L<AnyEvent::Impl::FLTK>.
2564		2938
2565	Non-blocking file handles, sockets, TCP clients and	2939	Non-blocking handles, pipes, stream sockets, TCP clients and
2566	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.	2940	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.
2567		2941
2568	Asynchronous DNS: L<AnyEvent::DNS>.	2942	Asynchronous DNS: L<AnyEvent::DNS>.
2569		2943
2570	Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>,	2944	Thread support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>.
2571	L<Coro::Event>,
2572		2945
2573	Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::XMPP>,	2946	Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::IRC>,
2574	L<AnyEvent::HTTP>.	2947	L<AnyEvent::HTTP>.
2575		2948
2576		2949
2577	=head1 AUTHOR	2950	=head1 AUTHOR
2578		2951

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