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Revision 1.279 by root, Sun Aug 9 16:05:11 2009 UTC vs.
Revision 1.375 by root, Thu Aug 25 05:39:47 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::FLTK2 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	Loads AnyEvent::Log on first use and calls C<AnyEvent::Log::log> -
		1059	consequently, look at the L<AnyEvent::Log> documentation for details.
		1060
		1061	If you want to sprinkle loads of logging calls around your code, consider
		1062	creating a logger callback with the C<AnyEvent::Log::logger> function.
		1063
953	=back	1064	=back
954		1065
955	=head1 WHAT TO DO IN A MODULE	1066	=head1 WHAT TO DO IN A MODULE
956		1067
957	As a module author, you should C<use AnyEvent> and call AnyEvent methods	1068	As a module author, you should C<use AnyEvent> and call AnyEvent methods
…		…
967	because it will stall the whole program, and the whole point of using	1078	because it will stall the whole program, and the whole point of using
968	events is to stay interactive.	1079	events is to stay interactive.
969		1080
970	It is fine, however, to call C<< ->recv >> when the user of your module	1081	It is fine, however, to call C<< ->recv >> when the user of your module
971	requests it (i.e. if you create a http request object ad have a method	1082	requests it (i.e. if you create a http request object ad have a method
972	called C<results> that returns the results, it should call C<< ->recv >>	1083	called C<results> that returns the results, it may call C<< ->recv >>
973	freely, as the user of your module knows what she is doing. always).	1084	freely, as the user of your module knows what she is doing. Always).
974		1085
975	=head1 WHAT TO DO IN THE MAIN PROGRAM	1086	=head1 WHAT TO DO IN THE MAIN PROGRAM
976		1087
977	There will always be a single main program - the only place that should	1088	There will always be a single main program - the only place that should
978	dictate which event model to use.	1089	dictate which event model to use.
979		1090
980	If it doesn't care, it can just "use AnyEvent" and use it itself, or not	1091	If the program is not event-based, it need not do anything special, even
981	do anything special (it does not need to be event-based) and let AnyEvent	1092	when it depends on a module that uses an AnyEvent. If the program itself
982	decide which implementation to chose if some module relies on it.	1093	uses AnyEvent, but does not care which event loop is used, all it needs
		1094	to do is C<use AnyEvent>. In either case, AnyEvent will choose the best
		1095	available loop implementation.
983		1096
984	If the main program relies on a specific event model - for example, in	1097	If the main program relies on a specific event model - for example, in
985	Gtk2 programs you have to rely on the Glib module - you should load the	1098	Gtk2 programs you have to rely on the Glib module - you should load the
986	event module before loading AnyEvent or any module that uses it: generally	1099	event module before loading AnyEvent or any module that uses it: generally
987	speaking, you should load it as early as possible. The reason is that	1100	speaking, you should load it as early as possible. The reason is that
988	modules might create watchers when they are loaded, and AnyEvent will	1101	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	1102	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.	1103	might choose the wrong one unless you load the correct one yourself.
991		1104
992	You can chose to use a pure-perl implementation by loading the	1105	You can chose to use a pure-perl implementation by loading the
993	C<AnyEvent::Impl::Perl> module, which gives you similar behaviour	1106	C<AnyEvent::Loop> module, which gives you similar behaviour
994	everywhere, but letting AnyEvent chose the model is generally better.	1107	everywhere, but letting AnyEvent chose the model is generally better.
995		1108
996	=head2 MAINLOOP EMULATION	1109	=head2 MAINLOOP EMULATION
997		1110
998	Sometimes (often for short test scripts, or even standalone programs who	1111	Sometimes (often for short test scripts, or even standalone programs who
…		…
1011		1124
1012		1125
1013	=head1 OTHER MODULES	1126	=head1 OTHER MODULES
1014		1127
1015	The following is a non-exhaustive list of additional modules that use	1128	The following is a non-exhaustive list of additional modules that use
1016	AnyEvent as a client and can therefore be mixed easily with other AnyEvent	1129	AnyEvent as a client and can therefore be mixed easily with other
1017	modules and other event loops in the same program. Some of the modules	1130	AnyEvent modules and other event loops in the same program. Some of the
1018	come with AnyEvent, most are available via CPAN.	1131	modules come as part of AnyEvent, the others are available via CPAN (see
		1132	L<http://search.cpan.org/search?m=module&q=anyevent%3A%3A*> for
		1133	a longer non-exhaustive list), and the list is heavily biased towards
		1134	modules of the AnyEvent author himself :)
1019		1135
1020	=over 4	1136	=over 4
1021		1137
1022	=item L<AnyEvent::Util>	1138	=item L<AnyEvent::Util>
1023		1139
1024	Contains various utility functions that replace often-used but blocking	1140	Contains various utility functions that replace often-used blocking
1025	functions such as C<inet_aton> by event-/callback-based versions.	1141	functions such as C<inet_aton> with event/callback-based versions.
1026		1142
1027	=item L<AnyEvent::Socket>	1143	=item L<AnyEvent::Socket>
1028		1144
1029	Provides various utility functions for (internet protocol) sockets,	1145	Provides various utility functions for (internet protocol) sockets,
1030	addresses and name resolution. Also functions to create non-blocking tcp	1146	addresses and name resolution. Also functions to create non-blocking tcp
…		…
1032		1148
1033	=item L<AnyEvent::Handle>	1149	=item L<AnyEvent::Handle>
1034		1150
1035	Provide read and write buffers, manages watchers for reads and writes,	1151	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	1152	supports raw and formatted I/O, I/O queued and fully transparent and
1037	non-blocking SSL/TLS (via L<AnyEvent::TLS>.	1153	non-blocking SSL/TLS (via L<AnyEvent::TLS>).
1038		1154
1039	=item L<AnyEvent::DNS>	1155	=item L<AnyEvent::DNS>
1040		1156
1041	Provides rich asynchronous DNS resolver capabilities.	1157	Provides rich asynchronous DNS resolver capabilities.
1042		1158
		1159	=item L<AnyEvent::HTTP>, L<AnyEvent::IRC>, L<AnyEvent::XMPP>, L<AnyEvent::GPSD>, L<AnyEvent::IGS>, L<AnyEvent::FCP>
		1160
		1161	Implement event-based interfaces to the protocols of the same name (for
		1162	the curious, IGS is the International Go Server and FCP is the Freenet
		1163	Client Protocol).
		1164
		1165	=item L<AnyEvent::Handle::UDP>
		1166
		1167	Here be danger!
		1168
		1169	As Pauli would put it, "Not only is it not right, it's not even wrong!" -
		1170	there are so many things wrong with AnyEvent::Handle::UDP, most notably
		1171	its use of a stream-based API with a protocol that isn't streamable, that
		1172	the only way to improve it is to delete it.
		1173
		1174	It features data corruption (but typically only under load) and general
		1175	confusion. On top, the author is not only clueless about UDP but also
		1176	fact-resistant - some gems of his understanding: "connect doesn't work
		1177	with UDP", "UDP packets are not IP packets", "UDP only has datagrams, not
		1178	packets", "I don't need to implement proper error checking as UDP doesn't
		1179	support error checking" and so on - he doesn't even understand what's
		1180	wrong with his module when it is explained to him.
		1181
1043	=item L<AnyEvent::HTTP>	1182	=item L<AnyEvent::DBI>
1044		1183
1045	A simple-to-use HTTP library that is capable of making a lot of concurrent	1184	Executes L<DBI> requests asynchronously in a proxy process for you,
1046	HTTP requests.	1185	notifying you in an event-based way when the operation is finished.
		1186
		1187	=item L<AnyEvent::AIO>
		1188
		1189	Truly asynchronous (as opposed to non-blocking) I/O, should be in the
		1190	toolbox of every event programmer. AnyEvent::AIO transparently fuses
		1191	L<IO::AIO> and AnyEvent together, giving AnyEvent access to event-based
		1192	file I/O, and much more.
1047		1193
1048	=item L<AnyEvent::HTTPD>	1194	=item L<AnyEvent::HTTPD>
1049		1195
1050	Provides a simple web application server framework.	1196	A simple embedded webserver.
1051		1197
1052	=item L<AnyEvent::FastPing>	1198	=item L<AnyEvent::FastPing>
1053		1199
1054	The fastest ping in the west.	1200	The fastest ping in the west.
1055
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		1201
1098	=item L<Coro>	1202	=item L<Coro>
1099		1203
1100	Has special support for AnyEvent via L<Coro::AnyEvent>.	1204	Has special support for AnyEvent via L<Coro::AnyEvent>.
1101		1205
…		…
1105		1209
1106	package AnyEvent;	1210	package AnyEvent;
1107		1211
1108	# basically a tuned-down version of common::sense	1212	# basically a tuned-down version of common::sense
1109	sub common_sense {	1213	sub common_sense {
1110	# no warnings	1214	# from common:.sense 3.4
1111	${^WARNING_BITS} ^= ${^WARNING_BITS};	1215	${^WARNING_BITS} ^= ${^WARNING_BITS} ^ "\x3c\x3f\x33\x00\x0f\xf0\x0f\xc0\xf0\xfc\x33\x00";
1112	# use strict vars subs	1216	# use strict vars subs - NO UTF-8, as Util.pm doesn't like this atm. (uts46data.pl)
1113	$^H |= 0x00000600;	1217	$^H |= 0x00000600;
1114	}	1218	}
1115		1219
1116	BEGIN { AnyEvent::common_sense }	1220	BEGIN { AnyEvent::common_sense }
1117		1221
1118	use Carp ();	1222	use Carp ();
1119		1223
1120	our $VERSION = '5.0';	1224	our $VERSION = '6.01';
1121	our $MODEL;	1225	our $MODEL;
1122		1226
1123	our $AUTOLOAD;
1124	our @ISA;	1227	our @ISA;
1125		1228
1126	our @REGISTRY;	1229	our @REGISTRY;
1127		1230
1128	our $WIN32;
1129
1130	our $VERBOSE;	1231	our $VERBOSE;
1131		1232
1132	BEGIN {	1233	BEGIN {
1133	eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }";	1234	require "AnyEvent/constants.pl";
		1235
1134	eval "sub TAINT(){ " . (${^TAINT}*1) . " }";	1236	eval "sub TAINT (){" . (${^TAINT}*1) . "}";
1135		1237
1136	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}	1238	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}
1137	if ${^TAINT};	1239	if ${^TAINT};
1138		1240
		1241	$ENV{"PERL_ANYEVENT_$_"} = $ENV{"AE_$_"}
		1242	for grep s/^AE_// && !exists $ENV{"PERL_ANYEVENT_$_"}, keys %ENV;
		1243
		1244	@ENV{grep /^PERL_ANYEVENT_/, keys %ENV} = ()
		1245	if ${^TAINT};
		1246
1139	$VERBOSE = $ENV{PERL_ANYEVENT_VERBOSE}*1;	1247	$VERBOSE = $ENV{PERL_ANYEVENT_VERBOSE}*1;
1140
1141	}	1248	}
1142		1249
1143	our $MAX_SIGNAL_LATENCY = 10;	1250	our $MAX_SIGNAL_LATENCY = 10;
1144		1251
1145	our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred	1252	our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred
…		…
1149	$PROTOCOL{$_} = ++$idx	1256	$PROTOCOL{$_} = ++$idx
1150	for reverse split /\s*,\s*/,	1257	for reverse split /\s*,\s*/,
1151	$ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";	1258	$ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";
1152	}	1259	}
1153		1260
		1261	our @post_detect;
		1262
		1263	sub post_detect(&) {
		1264	my ($cb) = @_;
		1265
		1266	push @post_detect, $cb;
		1267
		1268	defined wantarray
		1269	? bless \$cb, "AnyEvent::Util::postdetect"
		1270	: ()
		1271	}
		1272
		1273	sub AnyEvent::Util::postdetect::DESTROY {
		1274	@post_detect = grep $_ != ${$_[0]}, @post_detect;
		1275	}
		1276
		1277	our $POSTPONE_W;
		1278	our @POSTPONE;
		1279
		1280	sub _postpone_exec {
		1281	undef $POSTPONE_W;
		1282
		1283	&{ shift @POSTPONE }
		1284	while @POSTPONE;
		1285	}
		1286
		1287	sub postpone(&) {
		1288	push @POSTPONE, shift;
		1289
		1290	$POSTPONE_W ||= AE::timer (0, 0, \&_postpone_exec);
		1291
		1292	()
		1293	}
		1294
		1295	sub log($$;@) {
		1296	# only load the bug bloated module when we actually are about to log something
		1297	if ($_[0] <= $VERBOSE) {
		1298	require AnyEvent::Log;
		1299	# AnyEvent::Log overwrites this function
		1300	goto &log;
		1301	}
		1302	}
		1303
		1304	if (length $ENV{PERL_ANYEVENT_LOG}) {
		1305	require AnyEvent::Log; # AnyEvent::Log does the thing for us
		1306	}
		1307
1154	my @models = (	1308	our @models = (
1155	[EV:: => AnyEvent::Impl::EV:: , 1],	1309	[EV:: => AnyEvent::Impl::EV:: , 1],
1156	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl:: , 1],	1310	[AnyEvent::Loop:: => AnyEvent::Impl::Perl:: , 1],
1157	# everything below here will not (normally) be autoprobed	1311	# everything below here will not (normally) be autoprobed
1158	# as the pureperl backend should work everywhere	1312	# as the pure perl backend should work everywhere
1159	# and is usually faster	1313	# and is usually faster
1160	[Event:: => AnyEvent::Impl::Event::, 1],	1314	[Event:: => AnyEvent::Impl::Event::, 1],
1161	[Glib:: => AnyEvent::Impl::Glib:: , 1], # becomes extremely slow with many watchers	1315	[Glib:: => AnyEvent::Impl::Glib:: , 1], # becomes extremely slow with many watchers
1162	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy	1316	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
1163	[Irssi:: => AnyEvent::Impl::Irssi::], # Irssi has a bogus "Event" package	1317	[Irssi:: => AnyEvent::Impl::Irssi::], # Irssi has a bogus "Event" package
1164	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles	1318	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
1165	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program	1319	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program
1166	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza	1320	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
1167	[Wx:: => AnyEvent::Impl::POE::],	1321	[Wx:: => AnyEvent::Impl::POE::],
1168	[Prima:: => AnyEvent::Impl::POE::],	1322	[Prima:: => AnyEvent::Impl::POE::],
1169	# IO::Async is just too broken - we would need workarounds for its	1323	[IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # a bitch to autodetect
1170	# byzantine signal and broken child handling, among others.	1324	[Cocoa::EventLoop:: => AnyEvent::Impl::Cocoa::],
1171	# IO::Async is rather hard to detect, as it doesn't have any	1325	[FLTK:: => AnyEvent::Impl::FLTK2::],
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	);	1326	);
1178		1327
1179	our %method = map +($_ => 1),	1328	our @isa_hook;
		1329
		1330	sub _isa_set {
		1331	my @pkg = ("AnyEvent", (map $_->[0], grep defined, @isa_hook), $MODEL);
		1332
		1333	@{"$pkg[$_-1]::ISA"} = $pkg[$_]
		1334	for 1 .. $#pkg;
		1335
		1336	grep $_ && $_->[1], @isa_hook
		1337	and AE::_reset ();
		1338	}
		1339
		1340	# used for hooking AnyEvent::Strict and AnyEvent::Debug::Wrap into the class hierarchy
		1341	sub _isa_hook($$;$) {
		1342	my ($i, $pkg, $reset_ae) = @_;
		1343
		1344	$isa_hook[$i] = $pkg ? [$pkg, $reset_ae] : undef;
		1345
		1346	_isa_set;
		1347	}
		1348
		1349	# all autoloaded methods reserve the complete glob, not just the method slot.
		1350	# due to bugs in perls method cache implementation.
1180	qw(io timer time now now_update signal child idle condvar one_event DESTROY);	1351	our @methods = qw(io timer time now now_update signal child idle condvar);
1181		1352
1182	our @post_detect;
1183
1184	sub post_detect(&) {	1353	sub detect() {
1185	my ($cb) = @_;	1354	return $MODEL if $MODEL; # some programs keep references to detect
1186		1355
1187	if ($MODEL) {	1356	local $!; # for good measure
1188	$cb->();	1357	local $SIG{__DIE__}; # we use eval
1189		1358
1190	undef	1359	# free some memory
		1360	*detect = sub () { $MODEL };
		1361	# undef &func doesn't correctly update the method cache. grmbl.
		1362	# so we delete the whole glob. grmbl.
		1363	# otoh, perl doesn't let me undef an active usb, but it lets me free
		1364	# a glob with an active sub. hrm. i hope it works, but perl is
		1365	# usually buggy in this department. sigh.
		1366	delete @{"AnyEvent::"}{@methods};
		1367	undef @methods;
		1368
		1369	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z0-9:]+)$/) {
		1370	my $model = $1;
		1371	$model = "AnyEvent::Impl::$model" unless $model =~ s/::$//;
		1372	if (eval "require $model") {
		1373	AnyEvent::log 7 => "loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.";
		1374	$MODEL = $model;
1191	} else {	1375	} else {
1192	push @post_detect, $cb;	1376	AnyEvent::log warn => "unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@";
1193		1377	}
1194	defined wantarray
1195	? bless \$cb, "AnyEvent::Util::postdetect"
1196	: ()
1197	}	1378	}
1198	}
1199		1379
1200	sub AnyEvent::Util::postdetect::DESTROY {	1380	# check for already loaded models
1201	@post_detect = grep $_ != ${$_[0]}, @post_detect;
1202	}
1203
1204	sub detect() {
1205	unless ($MODEL) {	1381	unless ($MODEL) {
1206	local $SIG{__DIE__};	1382	for (@REGISTRY, @models) {
1207		1383	my ($package, $model) = @$_;
1208	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {	1384	if (${"$package\::VERSION"} > 0) {
1209	my $model = "AnyEvent::Impl::$1";
1210	if (eval "require $model") {	1385	if (eval "require $model") {
		1386	AnyEvent::log 7 => "autodetected model '$model', using it.";
1211	$MODEL = $model;	1387	$MODEL = $model;
1212	warn "AnyEvent: loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.\n" if $VERBOSE >= 2;	1388	last;
1213	} else {	1389	}
1214	warn "AnyEvent: unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@" if $VERBOSE;
1215	}	1390	}
1216	}	1391	}
1217		1392
1218	# check for already loaded models
1219	unless ($MODEL) {	1393	unless ($MODEL) {
		1394	# try to autoload a model
1220	for (@REGISTRY, @models) {	1395	for (@REGISTRY, @models) {
1221	my ($package, $model) = @$_;	1396	my ($package, $model, $autoload) = @$_;
		1397	if (
		1398	$autoload
		1399	and eval "require $package"
1222	if (${"$package\::VERSION"} > 0) {	1400	and ${"$package\::VERSION"} > 0
1223	if (eval "require $model") {	1401	and eval "require $model"
		1402	) {
		1403	AnyEvent::log 7 => "autoloaded model '$model', using it.";
1224	$MODEL = $model;	1404	$MODEL = $model;
1225	warn "AnyEvent: autodetected model '$model', using it.\n" if $VERBOSE >= 2;
1226	last;	1405	last;
1227	}
1228	}	1406	}
1229	}	1407	}
1230		1408
1231	unless ($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	1409	$MODEL
1248	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.\n";	1410	or die "AnyEvent: backend autodetection failed - did you properly install AnyEvent?";
1249	}
1250	}	1411	}
1251
1252	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
1253
1254	unshift @ISA, $MODEL;
1255
1256	require AnyEvent::Strict if $ENV{PERL_ANYEVENT_STRICT};
1257
1258	(shift @post_detect)->() while @post_detect;
1259	}	1412	}
1260		1413
		1414	# free memory only needed for probing
		1415	undef @models;
		1416	undef @REGISTRY;
		1417
		1418	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
		1419
		1420	# now nuke some methods that are overridden by the backend.
		1421	# SUPER usage is not allowed in these.
		1422	for (qw(time signal child idle)) {
		1423	undef &{"AnyEvent::Base::$_"}
		1424	if defined &{"$MODEL\::$_"};
		1425	}
		1426
		1427	_isa_set;
		1428
		1429	# we're officially open!
		1430
		1431	if ($ENV{PERL_ANYEVENT_STRICT}) {
		1432	require AnyEvent::Strict;
		1433	}
		1434
		1435	if ($ENV{PERL_ANYEVENT_DEBUG_WRAP}) {
		1436	require AnyEvent::Debug;
		1437	AnyEvent::Debug::wrap ($ENV{PERL_ANYEVENT_DEBUG_WRAP});
		1438	}
		1439
		1440	if (length $ENV{PERL_ANYEVENT_DEBUG_SHELL}) {
		1441	require AnyEvent::Socket;
		1442	require AnyEvent::Debug;
		1443
		1444	my $shell = $ENV{PERL_ANYEVENT_DEBUG_SHELL};
		1445	$shell =~ s/\$\$/$$/g;
		1446
		1447	my ($host, $service) = AnyEvent::Socket::parse_hostport ($shell);
		1448	$AnyEvent::Debug::SHELL = AnyEvent::Debug::shell ($host, $service);
		1449	}
		1450
		1451	# now the anyevent environment is set up as the user told us to, so
		1452	# call the actual user code - post detects
		1453
		1454	(shift @post_detect)->() while @post_detect;
		1455	undef @post_detect;
		1456
		1457	*post_detect = sub(&) {
		1458	shift->();
		1459
		1460	undef
		1461	};
		1462
1261	$MODEL	1463	$MODEL
1262	}	1464	}
1263		1465
1264	sub AUTOLOAD {	1466	for my $name (@methods) {
1265	(my $func = $AUTOLOAD) =~ s/.*://;	1467	*$name = sub {
1266		1468	detect;
1267	$method{$func}	1469	# we use goto because
1268	or Carp::croak "$func: not a valid method for AnyEvent objects";	1470	# a) it makes the thunk more transparent
1269		1471	# b) it allows us to delete the thunk later
1270	detect unless $MODEL;	1472	goto &{ UNIVERSAL::can AnyEvent => "SUPER::$name" }
1271		1473	};
1272	my $class = shift;
1273	$class->$func (@_);
1274	}	1474	}
1275		1475
1276	# utility function to dup a filehandle. this is used by many backends	1476	# utility function to dup a filehandle. this is used by many backends
1277	# to support binding more than one watcher per filehandle (they usually	1477	# 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).	1478	# allow only one watcher per fd, so we dup it to get a different one).
…		…
1292		1492
1293	=head1 SIMPLIFIED AE API	1493	=head1 SIMPLIFIED AE API
1294		1494
1295	Starting with version 5.0, AnyEvent officially supports a second, much	1495	Starting with version 5.0, AnyEvent officially supports a second, much
1296	simpler, API that is designed to reduce the calling, typing and memory	1496	simpler, API that is designed to reduce the calling, typing and memory
1297	overhead.	1497	overhead by using function call syntax and a fixed number of parameters.
1298		1498
1299	See the L<AE> manpage for details.	1499	See the L<AE> manpage for details.
1300		1500
1301	=cut	1501	=cut
1302		1502
1303	package AE;	1503	package AE;
1304		1504
1305	our $VERSION = $AnyEvent::VERSION;	1505	our $VERSION = $AnyEvent::VERSION;
1306		1506
		1507	sub _reset() {
		1508	eval q{
		1509	# fall back to the main API by default - backends and AnyEvent::Base
		1510	# implementations can overwrite these.
		1511
1307	sub io($$$) {	1512	sub io($$$) {
1308	AnyEvent->io (fh => $_[0], poll => $_[1] ? "w" : "r", cb => $_[2])	1513	AnyEvent->io (fh => $_[0], poll => $_[1] ? "w" : "r", cb => $_[2])
1309	}	1514	}
1310		1515
1311	sub timer($$$) {	1516	sub timer($$$) {
1312	AnyEvent->timer (after => $_[0], interval => $_[1], cb => $_[2])	1517	AnyEvent->timer (after => $_[0], interval => $_[1], cb => $_[2])
1313	}	1518	}
1314		1519
1315	sub signal($$) {	1520	sub signal($$) {
1316	AnyEvent->signal (signal => $_[0], cb => $_[1])	1521	AnyEvent->signal (signal => $_[0], cb => $_[1])
1317	}	1522	}
1318		1523
1319	sub child($$) {	1524	sub child($$) {
1320	AnyEvent->child (pid => $_[0], cb => $_[1])	1525	AnyEvent->child (pid => $_[0], cb => $_[1])
1321	}	1526	}
1322		1527
1323	sub idle($) {	1528	sub idle($) {
1324	AnyEvent->idle (cb => $_[0])	1529	AnyEvent->idle (cb => $_[0]);
1325	}	1530	}
1326		1531
1327	sub cv(;&) {	1532	sub cv(;&) {
1328	AnyEvent->condvar (@_ ? (cb => $_[0]) : ())	1533	AnyEvent->condvar (@_ ? (cb => $_[0]) : ())
1329	}	1534	}
1330		1535
1331	sub now() {	1536	sub now() {
1332	AnyEvent->now	1537	AnyEvent->now
1333	}	1538	}
1334		1539
1335	sub now_update() {	1540	sub now_update() {
1336	AnyEvent->now_update	1541	AnyEvent->now_update
1337	}	1542	}
1338		1543
1339	sub time() {	1544	sub time() {
1340	AnyEvent->time	1545	AnyEvent->time
		1546	}
		1547
		1548	*postpone = \&AnyEvent::postpone;
		1549	*log = \&AnyEvent::log;
		1550	};
		1551	die if $@;
1341	}	1552	}
		1553
		1554	BEGIN { _reset }
1342		1555
1343	package AnyEvent::Base;	1556	package AnyEvent::Base;
1344		1557
1345	# default implementations for many methods	1558	# default implementations for many methods
1346		1559
1347	sub _time {	1560	sub time {
		1561	eval q{ # poor man's autoloading {}
1348	# probe for availability of Time::HiRes	1562	# probe for availability of Time::HiRes
1349	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {	1563	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {
1350	warn "AnyEvent: using Time::HiRes for sub-second timing accuracy.\n" if $VERBOSE >= 8;	1564	AnyEvent::log 8 => "AnyEvent: using Time::HiRes for sub-second timing accuracy."
		1565	if $AnyEvent::VERBOSE >= 8;
		1566	*time = sub { Time::HiRes::time () };
1351	*_time = \&Time::HiRes::time;	1567	*AE::time = \& Time::HiRes::time ;
1352	# if (eval "use POSIX (); (POSIX::times())...	1568	# if (eval "use POSIX (); (POSIX::times())...
1353	} else {	1569	} else {
1354	warn "AnyEvent: using built-in time(), WARNING, no sub-second resolution!\n" if $VERBOSE;	1570	AnyEvent::log critical => "using built-in time(), WARNING, no sub-second resolution!";
1355	*_time = sub { time }; # epic fail	1571	*time = sub { CORE::time };
		1572	*AE::time = sub (){ CORE::time };
		1573	}
		1574
		1575	*now = \&time;
1356	}	1576	};
		1577	die if $@;
1357		1578
1358	&_time	1579	&time
1359	}	1580	}
1360		1581
1361	sub time { _time }	1582	*now = \&time;
1362	sub now { _time }
1363	sub now_update { }	1583	sub now_update { }
1364		1584
		1585	sub _poll {
		1586	Carp::croak "$AnyEvent::MODEL does not support blocking waits. Caught";
		1587	}
		1588
1365	# default implementation for ->condvar	1589	# default implementation for ->condvar
		1590	# in fact, the default should not be overwritten
1366		1591
1367	sub condvar {	1592	sub condvar {
		1593	eval q{ # poor man's autoloading {}
		1594	*condvar = sub {
1368	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"	1595	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"
		1596	};
		1597
		1598	*AE::cv = sub (;&) {
		1599	bless { @_ ? (_ae_cb => shift) : () }, "AnyEvent::CondVar"
		1600	};
		1601	};
		1602	die if $@;
		1603
		1604	&condvar
1369	}	1605	}
1370		1606
1371	# default implementation for ->signal	1607	# default implementation for ->signal
1372		1608
1373	our $HAVE_ASYNC_INTERRUPT;	1609	our $HAVE_ASYNC_INTERRUPT;
1374		1610
1375	sub _have_async_interrupt() {	1611	sub _have_async_interrupt() {
1376	$HAVE_ASYNC_INTERRUPT = 1*(!$ENV{PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT}	1612	$HAVE_ASYNC_INTERRUPT = 1*(!$ENV{PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT}
1377	&& eval "use Async::Interrupt 1.0 (); 1")	1613	&& eval "use Async::Interrupt 1.02 (); 1")
1378	unless defined $HAVE_ASYNC_INTERRUPT;	1614	unless defined $HAVE_ASYNC_INTERRUPT;
1379		1615
1380	$HAVE_ASYNC_INTERRUPT	1616	$HAVE_ASYNC_INTERRUPT
1381	}	1617	}
1382		1618
1383	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);	1619	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);
1384	our (%SIG_ASY, %SIG_ASY_W);	1620	our (%SIG_ASY, %SIG_ASY_W);
1385	our ($SIG_COUNT, $SIG_TW);	1621	our ($SIG_COUNT, $SIG_TW);
1386		1622
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	1623	# install a dummy wakeup watcher to reduce signal catching latency
		1624	# used by Impls
1401	sub _sig_add() {	1625	sub _sig_add() {
1402	unless ($SIG_COUNT++) {	1626	unless ($SIG_COUNT++) {
1403	# try to align timer on a full-second boundary, if possible	1627	# try to align timer on a full-second boundary, if possible
1404	my $NOW = AE::now;	1628	my $NOW = AE::now;
1405		1629
…		…
1415	undef $SIG_TW	1639	undef $SIG_TW
1416	unless --$SIG_COUNT;	1640	unless --$SIG_COUNT;
1417	}	1641	}
1418		1642
1419	our $_sig_name_init; $_sig_name_init = sub {	1643	our $_sig_name_init; $_sig_name_init = sub {
1420	eval q{ # poor man's autoloading	1644	eval q{ # poor man's autoloading {}
1421	undef $_sig_name_init;	1645	undef $_sig_name_init;
1422		1646
1423	if (_have_async_interrupt) {	1647	if (_have_async_interrupt) {
1424	*sig2num = \&Async::Interrupt::sig2num;	1648	*sig2num = \&Async::Interrupt::sig2num;
1425	*sig2name = \&Async::Interrupt::sig2name;	1649	*sig2name = \&Async::Interrupt::sig2name;
…		…
1449		1673
1450	sub signal {	1674	sub signal {
1451	eval q{ # poor man's autoloading {}	1675	eval q{ # poor man's autoloading {}
1452	# probe for availability of Async::Interrupt	1676	# probe for availability of Async::Interrupt
1453	if (_have_async_interrupt) {	1677	if (_have_async_interrupt) {
1454	warn "AnyEvent: using Async::Interrupt for race-free signal handling.\n" if $VERBOSE >= 8;	1678	AnyEvent::log 8 => "using Async::Interrupt for race-free signal handling."
		1679	if $AnyEvent::VERBOSE >= 8;
1455		1680
1456	$SIGPIPE_R = new Async::Interrupt::EventPipe;	1681	$SIGPIPE_R = new Async::Interrupt::EventPipe;
1457	$SIG_IO = AE::io $SIGPIPE_R->fileno, 0, \&_signal_exec;	1682	$SIG_IO = AE::io $SIGPIPE_R->fileno, 0, \&_signal_exec;
1458		1683
1459	} else {	1684	} else {
1460	warn "AnyEvent: using emulated perl signal handling with latency timer.\n" if $VERBOSE >= 8;	1685	AnyEvent::log 8 => "using emulated perl signal handling with latency timer."
1461		1686	if $AnyEvent::VERBOSE >= 8;
1462	require Fcntl;
1463		1687
1464	if (AnyEvent::WIN32) {	1688	if (AnyEvent::WIN32) {
1465	require AnyEvent::Util;	1689	require AnyEvent::Util;
1466		1690
1467	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();	1691	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
1468	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R, 1) if $SIGPIPE_R;	1692	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R, 1) if $SIGPIPE_R;
1469	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W, 1) if $SIGPIPE_W; # just in case	1693	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W, 1) if $SIGPIPE_W; # just in case
1470	} else {	1694	} else {
1471	pipe $SIGPIPE_R, $SIGPIPE_W;	1695	pipe $SIGPIPE_R, $SIGPIPE_W;
1472	fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R;	1696	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	1697	fcntl $SIGPIPE_W, AnyEvent::F_SETFL, AnyEvent::O_NONBLOCK if $SIGPIPE_W; # just in case
1474		1698
1475	# not strictly required, as $^F is normally 2, but let's make sure...	1699	# not strictly required, as $^F is normally 2, but let's make sure...
1476	fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;	1700	fcntl $SIGPIPE_R, AnyEvent::F_SETFD, AnyEvent::FD_CLOEXEC;
1477	fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;	1701	fcntl $SIGPIPE_W, AnyEvent::F_SETFD, AnyEvent::FD_CLOEXEC;
1478	}	1702	}
1479		1703
1480	$SIGPIPE_R	1704	$SIGPIPE_R
1481	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";	1705	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";
1482		1706
1483	$SIG_IO = AE::io $SIGPIPE_R, 0, \&_signal_exec;	1707	$SIG_IO = AE::io $SIGPIPE_R, 0, \&_signal_exec;
1484	}	1708	}
1485		1709
1486	*signal = sub {	1710	*signal = $HAVE_ASYNC_INTERRUPT
		1711	? sub {
1487	my (undef, %arg) = @_;	1712	my (undef, %arg) = @_;
1488		1713
1489	my $signal = uc $arg{signal}
1490	or Carp::croak "required option 'signal' is missing";
1491
1492	if ($HAVE_ASYNC_INTERRUPT) {
1493	# async::interrupt	1714	# async::interrupt
1494
1495	$signal = sig2num $signal;	1715	my $signal = sig2num $arg{signal};
1496	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};	1716	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
1497		1717
1498	$SIG_ASY{$signal} ||= new Async::Interrupt	1718	$SIG_ASY{$signal} ||= new Async::Interrupt
1499	cb => sub { undef $SIG_EV{$signal} },	1719	cb => sub { undef $SIG_EV{$signal} },
1500	signal => $signal,	1720	signal => $signal,
1501	pipe => [$SIGPIPE_R->filenos],	1721	pipe => [$SIGPIPE_R->filenos],
1502	pipe_autodrain => 0,	1722	pipe_autodrain => 0,
1503	;	1723	;
1504		1724
1505	} else {	1725	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
		1726	}
		1727	: sub {
		1728	my (undef, %arg) = @_;
		1729
1506	# pure perl	1730	# pure perl
1507
1508	# AE::Util has been loaded in signal
1509	$signal = sig2name $signal;	1731	my $signal = sig2name $arg{signal};
1510	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};	1732	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
1511		1733
1512	$SIG{$signal} ||= sub {	1734	$SIG{$signal} ||= sub {
1513	local $!;	1735	local $!;
1514	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;	1736	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;
1515	undef $SIG_EV{$signal};	1737	undef $SIG_EV{$signal};
1516	};	1738	};
1517		1739
1518	# can't do signal processing without introducing races in pure perl,	1740	# can't do signal processing without introducing races in pure perl,
1519	# so limit the signal latency.	1741	# so limit the signal latency.
1520	_sig_add;	1742	_sig_add;
1521	}
1522		1743
1523	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"	1744	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
		1745	}
1524	};	1746	;
1525		1747
1526	*AnyEvent::Base::signal::DESTROY = sub {	1748	*AnyEvent::Base::signal::DESTROY = sub {
1527	my ($signal, $cb) = @{$_[0]};	1749	my ($signal, $cb) = @{$_[0]};
1528		1750
1529	_sig_del;	1751	_sig_del;
…		…
1536	# print weird messages, or just unconditionally exit	1758	# print weird messages, or just unconditionally exit
1537	# instead of getting the default action.	1759	# instead of getting the default action.
1538	undef $SIG{$signal}	1760	undef $SIG{$signal}
1539	unless keys %{ $SIG_CB{$signal} };	1761	unless keys %{ $SIG_CB{$signal} };
1540	};	1762	};
		1763
		1764	*_signal_exec = sub {
		1765	$HAVE_ASYNC_INTERRUPT
		1766	? $SIGPIPE_R->drain
		1767	: sysread $SIGPIPE_R, (my $dummy), 9;
		1768
		1769	while (%SIG_EV) {
		1770	for (keys %SIG_EV) {
		1771	delete $SIG_EV{$_};
		1772	&$_ for values %{ $SIG_CB{$_} || {} };
		1773	}
		1774	}
		1775	};
1541	};	1776	};
1542	die if $@;	1777	die if $@;
		1778
1543	&signal	1779	&signal
1544	}	1780	}
1545		1781
1546	# default implementation for ->child	1782	# default implementation for ->child
1547		1783
1548	our %PID_CB;	1784	our %PID_CB;
1549	our $CHLD_W;	1785	our $CHLD_W;
1550	our $CHLD_DELAY_W;	1786	our $CHLD_DELAY_W;
1551	our $WNOHANG;
1552		1787
		1788	# used by many Impl's
1553	sub _emit_childstatus($$) {	1789	sub _emit_childstatus($$) {
1554	my (undef, $rpid, $rstatus) = @_;	1790	my (undef, $rpid, $rstatus) = @_;
1555		1791
1556	$_->($rpid, $rstatus)	1792	$_->($rpid, $rstatus)
1557	for values %{ $PID_CB{$rpid} || {} },	1793	for values %{ $PID_CB{$rpid} || {} },
1558	values %{ $PID_CB{0} || {} };	1794	values %{ $PID_CB{0} || {} };
1559	}	1795	}
1560		1796
1561	sub _sigchld {
1562	my $pid;
1563
1564	AnyEvent->_emit_childstatus ($pid, $?)
1565	while ($pid = waitpid -1, $WNOHANG) > 0;
1566	}
1567
1568	sub child {	1797	sub child {
		1798	eval q{ # poor man's autoloading {}
		1799	*_sigchld = sub {
		1800	my $pid;
		1801
		1802	AnyEvent->_emit_childstatus ($pid, $?)
		1803	while ($pid = waitpid -1, WNOHANG) > 0;
		1804	};
		1805
		1806	*child = sub {
1569	my (undef, %arg) = @_;	1807	my (undef, %arg) = @_;
1570		1808
1571	defined (my $pid = $arg{pid} + 0)	1809	my $pid = $arg{pid};
1572	or Carp::croak "required option 'pid' is missing";	1810	my $cb = $arg{cb};
1573		1811
1574	$PID_CB{$pid}{$arg{cb}} = $arg{cb};	1812	$PID_CB{$pid}{$cb+0} = $cb;
1575		1813
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) {	1814	unless ($CHLD_W) {
1582	$CHLD_W = AE::signal CHLD => \&_sigchld;	1815	$CHLD_W = AE::signal CHLD => \&_sigchld;
1583	# child could be a zombie already, so make at least one round	1816	# child could be a zombie already, so make at least one round
1584	&_sigchld;	1817	&_sigchld;
1585	}	1818	}
1586		1819
1587	bless [$pid, $arg{cb}], "AnyEvent::Base::child"	1820	bless [$pid, $cb+0], "AnyEvent::Base::child"
1588	}	1821	};
1589		1822
1590	sub AnyEvent::Base::child::DESTROY {	1823	*AnyEvent::Base::child::DESTROY = sub {
1591	my ($pid, $cb) = @{$_[0]};	1824	my ($pid, $icb) = @{$_[0]};
1592		1825
1593	delete $PID_CB{$pid}{$cb};	1826	delete $PID_CB{$pid}{$icb};
1594	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };	1827	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };
1595		1828
1596	undef $CHLD_W unless keys %PID_CB;	1829	undef $CHLD_W unless keys %PID_CB;
		1830	};
		1831	};
		1832	die if $@;
		1833
		1834	&child
1597	}	1835	}
1598		1836
1599	# idle emulation is done by simply using a timer, regardless	1837	# idle emulation is done by simply using a timer, regardless
1600	# of whether the process is idle or not, and not letting	1838	# of whether the process is idle or not, and not letting
1601	# the callback use more than 50% of the time.	1839	# the callback use more than 50% of the time.
1602	sub idle {	1840	sub idle {
		1841	eval q{ # poor man's autoloading {}
		1842	*idle = sub {
1603	my (undef, %arg) = @_;	1843	my (undef, %arg) = @_;
1604		1844
1605	my ($cb, $w, $rcb) = $arg{cb};	1845	my ($cb, $w, $rcb) = $arg{cb};
1606		1846
1607	$rcb = sub {	1847	$rcb = sub {
1608	if ($cb) {	1848	if ($cb) {
1609	$w = _time;	1849	$w = AE::time;
1610	&$cb;	1850	&$cb;
1611	$w = _time - $w;	1851	$w = AE::time - $w;
1612		1852
1613	# never use more then 50% of the time for the idle watcher,	1853	# never use more then 50% of the time for the idle watcher,
1614	# within some limits	1854	# within some limits
1615	$w = 0.0001 if $w < 0.0001;	1855	$w = 0.0001 if $w < 0.0001;
1616	$w = 5 if $w > 5;	1856	$w = 5 if $w > 5;
1617		1857
1618	$w = AE::timer $w, 0, $rcb;	1858	$w = AE::timer $w, 0, $rcb;
1619	} else {	1859	} else {
1620	# clean up...	1860	# clean up...
1621	undef $w;	1861	undef $w;
1622	undef $rcb;	1862	undef $rcb;
		1863	}
		1864	};
		1865
		1866	$w = AE::timer 0.05, 0, $rcb;
		1867
		1868	bless \\$cb, "AnyEvent::Base::idle"
1623	}	1869	};
		1870
		1871	*AnyEvent::Base::idle::DESTROY = sub {
		1872	undef $${$_[0]};
		1873	};
1624	};	1874	};
		1875	die if $@;
1625		1876
1626	$w = AE::timer 0.05, 0, $rcb;	1877	&idle
1627
1628	bless \\$cb, "AnyEvent::Base::idle"
1629	}
1630
1631	sub AnyEvent::Base::idle::DESTROY {
1632	undef $${$_[0]};
1633	}	1878	}
1634		1879
1635	package AnyEvent::CondVar;	1880	package AnyEvent::CondVar;
1636		1881
1637	our @ISA = AnyEvent::CondVar::Base::;	1882	our @ISA = AnyEvent::CondVar::Base::;
		1883
		1884	# only to be used for subclassing
		1885	sub new {
		1886	my $class = shift;
		1887	bless AnyEvent->condvar (@_), $class
		1888	}
1638		1889
1639	package AnyEvent::CondVar::Base;	1890	package AnyEvent::CondVar::Base;
1640		1891
1641	#use overload	1892	#use overload
1642	# '&{}' => sub { my $self = shift; sub { $self->send (@_) } },	1893	# '&{}' => sub { my $self = shift; sub { $self->send (@_) } },
…		…
1652		1903
1653	sub _send {	1904	sub _send {
1654	# nop	1905	# nop
1655	}	1906	}
1656		1907
		1908	sub _wait {
		1909	AnyEvent->_poll until $_[0]{_ae_sent};
		1910	}
		1911
1657	sub send {	1912	sub send {
1658	my $cv = shift;	1913	my $cv = shift;
1659	$cv->{_ae_sent} = [@_];	1914	$cv->{_ae_sent} = [@_];
1660	(delete $cv->{_ae_cb})->($cv) if $cv->{_ae_cb};	1915	(delete $cv->{_ae_cb})->($cv) if $cv->{_ae_cb};
1661	$cv->_send;	1916	$cv->_send;
…		…
1668		1923
1669	sub ready {	1924	sub ready {
1670	$_[0]{_ae_sent}	1925	$_[0]{_ae_sent}
1671	}	1926	}
1672		1927
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 {	1928	sub recv {
		1929	unless ($_[0]{_ae_sent}) {
		1930	$WAITING
		1931	and Carp::croak "AnyEvent::CondVar: recursive blocking wait attempted";
		1932
		1933	local $WAITING = 1;
1683	$_[0]->_wait;	1934	$_[0]->_wait;
		1935	}
1684		1936
1685	Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak};	1937	$_[0]{_ae_croak}
1686	wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0]	1938	and Carp::croak $_[0]{_ae_croak};
		1939
		1940	wantarray
		1941	? @{ $_[0]{_ae_sent} }
		1942	: $_[0]{_ae_sent}[0]
1687	}	1943	}
1688		1944
1689	sub cb {	1945	sub cb {
1690	my $cv = shift;	1946	my $cv = shift;
1691		1947
…		…
1707	&{ $_[0]{_ae_end_cb} || sub { $_[0]->send } };	1963	&{ $_[0]{_ae_end_cb} || sub { $_[0]->send } };
1708	}	1964	}
1709		1965
1710	# undocumented/compatibility with pre-3.4	1966	# undocumented/compatibility with pre-3.4
1711	*broadcast = \&send;	1967	*broadcast = \&send;
1712	*wait = \&_wait;	1968	*wait = \&recv;
1713		1969
1714	=head1 ERROR AND EXCEPTION HANDLING	1970	=head1 ERROR AND EXCEPTION HANDLING
1715		1971
1716	In general, AnyEvent does not do any error handling - it relies on the	1972	In general, AnyEvent does not do any error handling - it relies on the
1717	caller to do that if required. The L<AnyEvent::Strict> module (see also	1973	caller to do that if required. The L<AnyEvent::Strict> module (see also
…		…
1729	$Event/EV::DIED->() >>, L<Glib> uses C<< install_exception_handler >> and	1985	$Event/EV::DIED->() >>, L<Glib> uses C<< install_exception_handler >> and
1730	so on.	1986	so on.
1731		1987
1732	=head1 ENVIRONMENT VARIABLES	1988	=head1 ENVIRONMENT VARIABLES
1733		1989
1734	The following environment variables are used by this module or its	1990	AnyEvent supports a number of environment variables that tune the
1735	submodules.	1991	runtime behaviour. They are usually evaluated when AnyEvent is
		1992	loaded, initialised, or a submodule that uses them is loaded. Many of
		1993	them also cause AnyEvent to load additional modules - for example,
		1994	C<PERL_ANYEVENT_DEBUG_WRAP> causes the L<AnyEvent::Debug> module to be
		1995	loaded.
1736		1996
1737	Note that AnyEvent will remove I<all> environment variables starting with	1997	All the environment variables documented here start with
1738	C<PERL_ANYEVENT_> from C<%ENV> when it is loaded while taint mode is	1998	C<PERL_ANYEVENT_>, which is what AnyEvent considers its own
1739	enabled.	1999	namespace. Other modules are encouraged (but by no means required) to use
		2000	C<PERL_ANYEVENT_SUBMODULE> if they have registered the AnyEvent::Submodule
		2001	namespace on CPAN, for any submodule. For example, L<AnyEvent::HTTP> could
		2002	be expected to use C<PERL_ANYEVENT_HTTP_PROXY> (it should not access env
		2003	variables starting with C<AE_>, see below).
		2004
		2005	All variables can also be set via the C<AE_> prefix, that is, instead
		2006	of setting C<PERL_ANYEVENT_VERBOSE> you can also set C<AE_VERBOSE>. In
		2007	case there is a clash btween anyevent and another program that uses
		2008	C<AE_something> you can set the corresponding C<PERL_ANYEVENT_something>
		2009	variable to the empty string, as those variables take precedence.
		2010
		2011	When AnyEvent is first loaded, it copies all C<AE_xxx> env variables
		2012	to their C<PERL_ANYEVENT_xxx> counterpart unless that variable already
		2013	exists. If taint mode is on, then AnyEvent will remove I<all> environment
		2014	variables starting with C<PERL_ANYEVENT_> from C<%ENV> (or replace them
		2015	with C<undef> or the empty string, if the corresaponding C<AE_> variable
		2016	is set).
		2017
		2018	The exact algorithm is currently:
		2019
		2020	1. if taint mode enabled, delete all PERL_ANYEVENT_xyz variables from %ENV
		2021	2. copy over AE_xyz to PERL_ANYEVENT_xyz unless the latter alraedy exists
		2022	3. if taint mode enabled, set all PERL_ANYEVENT_xyz variables to undef.
		2023
		2024	This ensures that child processes will not see the C<AE_> variables.
		2025
		2026	The following environment variables are currently known to AnyEvent:
1740		2027
1741	=over 4	2028	=over 4
1742		2029
1743	=item C<PERL_ANYEVENT_VERBOSE>	2030	=item C<PERL_ANYEVENT_VERBOSE>
1744		2031
1745	By default, AnyEvent will be completely silent except in fatal	2032	By default, AnyEvent will be completely silent except in fatal
1746	conditions. You can set this environment variable to make AnyEvent more	2033	conditions. You can set this environment variable to make AnyEvent more
1747	talkative.	2034	talkative. If you want to do more than just set the global logging level
		2035	you should have a look at C<PERL_ANYEVENT_LOG>, which allows much more
		2036	complex specifications.
1748		2037
1749	When set to C<1> or higher, causes AnyEvent to warn about unexpected	2038	When set to C<5> or higher, causes AnyEvent to warn about unexpected
1750	conditions, such as not being able to load the event model specified by	2039	conditions, such as not being able to load the event model specified by
1751	C<PERL_ANYEVENT_MODEL>.	2040	C<PERL_ANYEVENT_MODEL>.
1752		2041
1753	When set to C<2> or higher, cause AnyEvent to report to STDERR which event	2042	When set to C<7> or higher, cause AnyEvent to report to STDERR which event
1754	model it chooses.	2043	model it chooses.
1755		2044
1756	When set to C<8> or higher, then AnyEvent will report extra information on	2045	When set to C<8> or higher, then AnyEvent will report extra information on
1757	which optional modules it loads and how it implements certain features.	2046	which optional modules it loads and how it implements certain features.
		2047
		2048	=item C<PERL_ANYEVENT_LOG>
		2049
		2050	Accepts rather complex logging specifications. For example, you could log
		2051	all C<debug> messages of some module to stderr, warnings and above to
		2052	stderr, and errors and above to syslog, with:
		2053
		2054	PERL_ANYEVENT_LOG=Some::Module=debug,+log:filter=warn,+%syslog:%syslog=error,syslog
		2055
		2056	For the rather extensive details, see L<AnyEvent::Log>.
		2057
		2058	This variable is evaluated when AnyEvent (or L<AnyEvent::Log>) is loaded,
		2059	so will take effect even before AnyEvent has initialised itself.
		2060
		2061	Note that specifying this environment variable causes the L<AnyEvent::Log>
		2062	module to be loaded, while C<PERL_ANYEVENT_VERBOSE> does not, so only
		2063	using the latter saves a few hundred kB of memory until the first message
		2064	is being logged.
1758		2065
1759	=item C<PERL_ANYEVENT_STRICT>	2066	=item C<PERL_ANYEVENT_STRICT>
1760		2067
1761	AnyEvent does not do much argument checking by default, as thorough	2068	AnyEvent does not do much argument checking by default, as thorough
1762	argument checking is very costly. Setting this variable to a true value	2069	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,	2071	check the arguments passed to most method calls. If it finds any problems,
1765	it will croak.	2072	it will croak.
1766		2073
1767	In other words, enables "strict" mode.	2074	In other words, enables "strict" mode.
1768		2075
1769	Unlike C<use strict> (or it's modern cousin, C<< use L<common::sense>	2076	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	2077	>>, it is definitely recommended to keep it off in production. Keeping
1771	C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs	2078	C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs
1772	can be very useful, however.	2079	can be very useful, however.
1773		2080
		2081	=item C<PERL_ANYEVENT_DEBUG_SHELL>
		2082
		2083	If this env variable is set, then its contents will be interpreted by
		2084	C<AnyEvent::Socket::parse_hostport> (after replacing every occurance of
		2085	C<$$> by the process pid) and an C<AnyEvent::Debug::shell> is bound on
		2086	that port. The shell object is saved in C<$AnyEvent::Debug::SHELL>.
		2087
		2088	This happens when the first watcher is created.
		2089
		2090	For example, to bind a debug shell on a unix domain socket in
		2091	F<< /tmp/debug<pid>.sock >>, you could use this:
		2092
		2093	PERL_ANYEVENT_DEBUG_SHELL=/tmp/debug\$\$.sock perlprog
		2094
		2095	Note that creating sockets in F</tmp> is very unsafe on multiuser
		2096	systems.
		2097
		2098	=item C<PERL_ANYEVENT_DEBUG_WRAP>
		2099
		2100	Can be set to C<0>, C<1> or C<2> and enables wrapping of all watchers for
		2101	debugging purposes. See C<AnyEvent::Debug::wrap> for details.
		2102
1774	=item C<PERL_ANYEVENT_MODEL>	2103	=item C<PERL_ANYEVENT_MODEL>
1775		2104
1776	This can be used to specify the event model to be used by AnyEvent, before	2105	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	2106	auto detection and -probing kicks in.
1778	entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended	2107
		2108	It normally is a string consisting entirely of ASCII letters (e.g. C<EV>
		2109	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,	2110	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	2111	event model backend. If it fails to load then AnyEvent will proceed with
1781	auto detection and -probing.	2112	auto detection and -probing.
1782		2113
1783	This functionality might change in future versions.	2114	If the string ends with C<::> instead (e.g. C<AnyEvent::Impl::EV::>) then
		2115	nothing gets prepended and the module name is used as-is (hint: C<::> at
		2116	the end of a string designates a module name and quotes it appropriately).
1784		2117
1785	For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you	2118	For example, to force the pure perl model (L<AnyEvent::Loop::Perl>) you
1786	could start your program like this:	2119	could start your program like this:
1787		2120
1788	PERL_ANYEVENT_MODEL=Perl perl ...	2121	PERL_ANYEVENT_MODEL=Perl perl ...
1789		2122
1790	=item C<PERL_ANYEVENT_PROTOCOLS>	2123	=item C<PERL_ANYEVENT_PROTOCOLS>
…		…
1806	but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4>	2139	but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4>
1807	- only support IPv4, never try to resolve or contact IPv6	2140	- only support IPv4, never try to resolve or contact IPv6
1808	addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or	2141	addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or
1809	IPv6, but prefer IPv6 over IPv4.	2142	IPv6, but prefer IPv6 over IPv4.
1810		2143
		2144	=item C<PERL_ANYEVENT_HOSTS>
		2145
		2146	This variable, if specified, overrides the F</etc/hosts> file used by
		2147	L<AnyEvent::Socket>C<::resolve_sockaddr>, i.e. hosts aliases will be read
		2148	from that file instead.
		2149
1811	=item C<PERL_ANYEVENT_EDNS0>	2150	=item C<PERL_ANYEVENT_EDNS0>
1812		2151
1813	Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension	2152	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	2153	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	2154	when DNSSEC is involved, but some (broken) firewalls drop such DNS
1816	default.	2155	packets, which is why it is off by default.
1817		2156
1818	Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce	2157	Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce
1819	EDNS0 in its DNS requests.	2158	EDNS0 in its DNS requests.
1820		2159
1821	=item C<PERL_ANYEVENT_MAX_FORKS>	2160	=item C<PERL_ANYEVENT_MAX_FORKS>
…		…
1829	resolver - this is the maximum number of parallel DNS requests that are	2168	resolver - this is the maximum number of parallel DNS requests that are
1830	sent to the DNS server.	2169	sent to the DNS server.
1831		2170
1832	=item C<PERL_ANYEVENT_RESOLV_CONF>	2171	=item C<PERL_ANYEVENT_RESOLV_CONF>
1833		2172
1834	The file to use instead of F</etc/resolv.conf> (or OS-specific	2173	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	2174	F</etc/resolv.conf> (or the OS-specific configuration) in the default
1836	default config will be used.	2175	resolver, or the empty string to select the default configuration.
1837		2176
1838	=item C<PERL_ANYEVENT_CA_FILE>, C<PERL_ANYEVENT_CA_PATH>.	2177	=item C<PERL_ANYEVENT_CA_FILE>, C<PERL_ANYEVENT_CA_PATH>.
1839		2178
1840	When neither C<ca_file> nor C<ca_path> was specified during	2179	When neither C<ca_file> nor C<ca_path> was specified during
1841	L<AnyEvent::TLS> context creation, and either of these environment	2180	L<AnyEvent::TLS> context creation, and either of these environment
1842	variables exist, they will be used to specify CA certificate locations	2181	variables are nonempty, they will be used to specify CA certificate
1843	instead of a system-dependent default.	2182	locations instead of a system-dependent default.
1844		2183
1845	=item C<PERL_ANYEVENT_AVOID_GUARD> and C<PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT>	2184	=item C<PERL_ANYEVENT_AVOID_GUARD> and C<PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT>
1846		2185
1847	When these are set to C<1>, then the respective modules are not	2186	When these are set to C<1>, then the respective modules are not
1848	loaded. Mostly good for testing AnyEvent itself.	2187	loaded. Mostly good for testing AnyEvent itself.
…		…
1911	warn "read: $input\n"; # output what has been read	2250	warn "read: $input\n"; # output what has been read
1912	$cv->send if $input =~ /^q/i; # quit program if /^q/i	2251	$cv->send if $input =~ /^q/i; # quit program if /^q/i
1913	},	2252	},
1914	);	2253	);
1915		2254
1916	my $time_watcher; # can only be used once
1917
1918	sub new_timer {
1919	$timer = AnyEvent->timer (after => 1, cb => sub {	2255	my $time_watcher = AnyEvent->timer (after => 1, interval => 1, cb => sub {
1920	warn "timeout\n"; # print 'timeout' about every second	2256	warn "timeout\n"; # print 'timeout' at most every second
1921	&new_timer; # and restart the time
1922	});	2257	});
1923	}
1924
1925	new_timer; # create first timer
1926		2258
1927	$cv->recv; # wait until user enters /^q/i	2259	$cv->recv; # wait until user enters /^q/i
1928		2260
1929	=head1 REAL-WORLD EXAMPLE	2261	=head1 REAL-WORLD EXAMPLE
1930		2262
…		…
2003		2335
2004	The actual code goes further and collects all errors (C<die>s, exceptions)	2336	The actual code goes further and collects all errors (C<die>s, exceptions)
2005	that occurred during request processing. The C<result> method detects	2337	that occurred during request processing. The C<result> method detects
2006	whether an exception as thrown (it is stored inside the $txn object)	2338	whether an exception as thrown (it is stored inside the $txn object)
2007	and just throws the exception, which means connection errors and other	2339	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	2340	problems get reported to the code that tries to use the result, not in a
2009	random callback.	2341	random callback.
2010		2342
2011	All of this enables the following usage styles:	2343	All of this enables the following usage styles:
2012		2344
2013	1. Blocking:	2345	1. Blocking:
…		…
2187	(even when used without AnyEvent), but most event loops have acceptable	2519	(even when used without AnyEvent), but most event loops have acceptable
2188	performance with or without AnyEvent.	2520	performance with or without AnyEvent.
2189		2521
2190	=item * The overhead AnyEvent adds is usually much smaller than the overhead of	2522	=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	2523	the actual event loop, only with extremely fast event loops such as EV
2192	adds AnyEvent significant overhead.	2524	does AnyEvent add significant overhead.
2193		2525
2194	=item * You should avoid POE like the plague if you want performance or	2526	=item * You should avoid POE like the plague if you want performance or
2195	reasonable memory usage.	2527	reasonable memory usage.
2196		2528
2197	=back	2529	=back
…		…
2374	As you can see, the AnyEvent + EV combination even beats the	2706	As you can see, the AnyEvent + EV combination even beats the
2375	hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl	2707	hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl
2376	backend easily beats IO::Lambda and POE.	2708	backend easily beats IO::Lambda and POE.
2377		2709
2378	And even the 100% non-blocking version written using the high-level (and	2710	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	2711	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	2712	higher level ("unoptimised") abstractions by a large margin, even though
2381	in a non-blocking way.	2713	it does all of DNS, tcp-connect and socket I/O in a non-blocking way.
2382		2714
2383	The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and	2715	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	2716	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.	2717	part of the IO::Lambda distribution and were used without any changes.
2386		2718
2387		2719
2388	=head1 SIGNALS	2720	=head1 SIGNALS
2389		2721
2390	AnyEvent currently installs handlers for these signals:	2722	AnyEvent currently installs handlers for these signals:
…		…
2427	unless defined $SIG{PIPE};	2759	unless defined $SIG{PIPE};
2428		2760
2429	=head1 RECOMMENDED/OPTIONAL MODULES	2761	=head1 RECOMMENDED/OPTIONAL MODULES
2430		2762
2431	One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and	2763	One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and
2432	it's built-in modules) are required to use it.	2764	its built-in modules) are required to use it.
2433		2765
2434	That does not mean that AnyEvent won't take advantage of some additional	2766	That does not mean that AnyEvent won't take advantage of some additional
2435	modules if they are installed.	2767	modules if they are installed.
2436		2768
2437	This section epxlains which additional modules will be used, and how they	2769	This section explains which additional modules will be used, and how they
2438	affect AnyEvent's operetion.	2770	affect AnyEvent's operation.
2439		2771
2440	=over 4	2772	=over 4
2441		2773
2442	=item L<Async::Interrupt>	2774	=item L<Async::Interrupt>
2443		2775
…		…
2448	catch the signals) with some delay (default is 10 seconds, look for	2780	catch the signals) with some delay (default is 10 seconds, look for
2449	C<$AnyEvent::MAX_SIGNAL_LATENCY>).	2781	C<$AnyEvent::MAX_SIGNAL_LATENCY>).
2450		2782
2451	If this module is available, then it will be used to implement signal	2783	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	2784	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	2785	will not be interrupted regularly, which is more efficient (and good for
2454	battery life on laptops).	2786	battery life on laptops).
2455		2787
2456	This affects not just the pure-perl event loop, but also other event loops	2788	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).	2789	that have no signal handling on their own (e.g. Glib, Tk, Qt).
2458		2790
…		…
2470	automatic timer adjustments even when no monotonic clock is available,	2802	automatic timer adjustments even when no monotonic clock is available,
2471	can take avdantage of advanced kernel interfaces such as C<epoll> and	2803	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	2804	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>).	2805	L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>).
2474		2806
		2807	If you only use backends that rely on another event loop (e.g. C<Tk>),
		2808	then this module will do nothing for you.
		2809
2475	=item L<Guard>	2810	=item L<Guard>
2476		2811
2477	The guard module, when used, will be used to implement	2812	The guard module, when used, will be used to implement
2478	C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a	2813	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	2814	lot less memory), but otherwise doesn't affect guard operation much. It is
2480	purely used for performance.	2815	purely used for performance.
2481		2816
2482	=item L<JSON> and L<JSON::XS>	2817	=item L<JSON> and L<JSON::XS>
2483		2818
2484	This module is required when you want to read or write JSON data via	2819	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	2820	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.	2821	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		2822
2491	=item L<Net::SSLeay>	2823	=item L<Net::SSLeay>
2492		2824
2493	Implementing TLS/SSL in Perl is certainly interesting, but not very	2825	Implementing TLS/SSL in Perl is certainly interesting, but not very
2494	worthwhile: If this module is installed, then L<AnyEvent::Handle> (with	2826	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.	2827	the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL.
2496		2828
2497	=item L<Time::HiRes>	2829	=item L<Time::HiRes>
2498		2830
2499	This module is part of perl since release 5.008. It will be used when the	2831	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	2832	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	2833	pure-perl event loop (L<AnyEvent::Loop>) will additionally load it to
2502	try to use a monotonic clock for timing stability.	2834	try to use a monotonic clock for timing stability.
2503		2835
2504	=back	2836	=back
2505		2837
2506		2838
2507	=head1 FORK	2839	=head1 FORK
2508		2840
2509	Most event libraries are not fork-safe. The ones who are usually are	2841	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>	2842	because they rely on inefficient but fork-safe C<select> or C<poll> calls
2511	calls. Only L<EV> is fully fork-aware.	2843	- higher performance APIs such as BSD's kqueue or the dreaded Linux epoll
		2844	are usually badly thought-out hacks that are incompatible with fork in
		2845	one way or another. Only L<EV> is fully fork-aware and ensures that you
		2846	continue event-processing in both parent and child (or both, if you know
		2847	what you are doing).
		2848
		2849	This means that, in general, you cannot fork and do event processing in
		2850	the child if the event library was initialised before the fork (which
		2851	usually happens when the first AnyEvent watcher is created, or the library
		2852	is loaded).
2512		2853
2513	If you have to fork, you must either do so I<before> creating your first	2854	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	2855	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.	2856	something completely out of the scope of AnyEvent.
		2857
		2858	The problem of doing event processing in the parent I<and> the child
		2859	is much more complicated: even for backends that I<are> fork-aware or
		2860	fork-safe, their behaviour is not usually what you want: fork clones all
		2861	watchers, that means all timers, I/O watchers etc. are active in both
		2862	parent and child, which is almost never what you want. USing C<exec>
		2863	to start worker children from some kind of manage rprocess is usually
		2864	preferred, because it is much easier and cleaner, at the expense of having
		2865	to have another binary.
2516		2866
2517		2867
2518	=head1 SECURITY CONSIDERATIONS	2868	=head1 SECURITY CONSIDERATIONS
2519		2869
2520	AnyEvent can be forced to load any event model via	2870	AnyEvent can be forced to load any event model via
…		…
2550	pronounced).	2900	pronounced).
2551		2901
2552		2902
2553	=head1 SEE ALSO	2903	=head1 SEE ALSO
2554		2904
2555	Utility functions: L<AnyEvent::Util>.	2905	Tutorial/Introduction: L<AnyEvent::Intro>.
2556		2906
2557	Event modules: L<EV>, L<EV::Glib>, L<Glib::EV>, L<Event>, L<Glib::Event>,	2907	FAQ: L<AnyEvent::FAQ>.
2558	L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.	2908
		2909	Utility functions: L<AnyEvent::Util> (misc. grab-bag), L<AnyEvent::Log>
		2910	(simply logging).
		2911
		2912	Development/Debugging: L<AnyEvent::Strict> (stricter checking),
		2913	L<AnyEvent::Debug> (interactive shell, watcher tracing).
		2914
		2915	Supported event modules: L<AnyEvent::Loop>, L<EV>, L<EV::Glib>,
		2916	L<Glib::EV>, L<Event>, L<Glib::Event>, L<Glib>, L<Tk>, L<Event::Lib>,
		2917	L<Qt>, L<POE>, L<FLTK>.
2559		2918
2560	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,	2919	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,
2561	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,	2920	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,
2562	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,	2921	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,
2563	L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>, L<Anyevent::Impl::Irssi>.	2922	L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>, L<Anyevent::Impl::Irssi>,
		2923	L<AnyEvent::Impl::FLTK>.
2564		2924
2565	Non-blocking file handles, sockets, TCP clients and	2925	Non-blocking handles, pipes, stream sockets, TCP clients and
2566	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.	2926	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.
2567		2927
2568	Asynchronous DNS: L<AnyEvent::DNS>.	2928	Asynchronous DNS: L<AnyEvent::DNS>.
2569		2929
2570	Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>,	2930	Thread support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>.
2571	L<Coro::Event>,
2572		2931
2573	Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::XMPP>,	2932	Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::IRC>,
2574	L<AnyEvent::HTTP>.	2933	L<AnyEvent::HTTP>.
2575		2934
2576		2935
2577	=head1 AUTHOR	2936	=head1 AUTHOR
2578		2937

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