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Revision 1.388 by root, Sun Oct 2 01:22:01 2011 UTC

1	=head1 NAME	1	=head1 NAME
2		2
3	AnyEvent - the DBI of event loop programming	3	AnyEvent - the DBI of event loop programming
4		4
5	EV, Event, Glib, Tk, Perl, Event::Lib, Irssi, rxvt-unicode, IO::Async, Qt	5	EV, Event, Glib, Tk, Perl, Event::Lib, Irssi, rxvt-unicode, IO::Async, Qt,
6	and POE are various supported event loops/environments.	6	FLTK and POE are various supported event loops/environments.
7		7
8	=head1 SYNOPSIS	8	=head1 SYNOPSIS
9		9
10	use AnyEvent;	10	use AnyEvent;
11		11
		12	# if you prefer function calls, look at the AE manpage for
		13	# an alternative API.
		14
12	# file descriptor readable	15	# file handle or descriptor readable
13	my $w = AnyEvent->io (fh => $fh, poll => "r", cb => sub { ... });	16	my $w = AnyEvent->io (fh => $fh, poll => "r", cb => sub { ... });
14		17
15	# one-shot or repeating timers	18	# one-shot or repeating timers
16	my $w = AnyEvent->timer (after => $seconds, cb => sub { ... });	19	my $w = AnyEvent->timer (after => $seconds, cb => sub { ... });
17	my $w = AnyEvent->timer (after => $seconds, interval => $seconds, cb => ...	20	my $w = AnyEvent->timer (after => $seconds, interval => $seconds, cb => ...);
18		21
19	print AnyEvent->now; # prints current event loop time	22	print AnyEvent->now; # prints current event loop time
20	print AnyEvent->time; # think Time::HiRes::time or simply CORE::time.	23	print AnyEvent->time; # think Time::HiRes::time or simply CORE::time.
21		24
22	# POSIX signal	25	# POSIX signal
…		…
43	in a tutorial or some gentle introduction, have a look at the	46	in a tutorial or some gentle introduction, have a look at the
44	L<AnyEvent::Intro> manpage.	47	L<AnyEvent::Intro> manpage.
45		48
46	=head1 SUPPORT	49	=head1 SUPPORT
47		50
		51	An FAQ document is available as L<AnyEvent::FAQ>.
		52
48	There is a mailinglist for discussing all things AnyEvent, and an IRC	53	There also is a mailinglist for discussing all things AnyEvent, and an IRC
49	channel, too.	54	channel, too.
50		55
51	See the AnyEvent project page at the B<Schmorpforge Ta-Sa Software	56	See the AnyEvent project page at the B<Schmorpforge Ta-Sa Software
52	Repository>, at L<http://anyevent.schmorp.de>, for more info.	57	Repository>, at L<http://anyevent.schmorp.de>, for more info.
53		58
…		…
73	module users into the same thing by forcing them to use the same event	78	module users into the same thing by forcing them to use the same event
74	model you use.	79	model you use.
75		80
76	For modules like POE or IO::Async (which is a total misnomer as it is	81	For modules like POE or IO::Async (which is a total misnomer as it is
77	actually doing all I/O I<synchronously>...), using them in your module is	82	actually doing all I/O I<synchronously>...), using them in your module is
78	like joining a cult: After you joined, you are dependent on them and you	83	like joining a cult: After you join, you are dependent on them and you
79	cannot use anything else, as they are simply incompatible to everything	84	cannot use anything else, as they are simply incompatible to everything
80	that isn't them. What's worse, all the potential users of your	85	that isn't them. What's worse, all the potential users of your
81	module are I<also> forced to use the same event loop you use.	86	module are I<also> forced to use the same event loop you use.
82		87
83	AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works	88	AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works
84	fine. AnyEvent + Tk works fine etc. etc. but none of these work together	89	fine. AnyEvent + Tk works fine etc. etc. but none of these work together
85	with the rest: POE + IO::Async? No go. Tk + Event? No go. Again: if	90	with the rest: POE + EV? No go. Tk + Event? No go. Again: if your module
86	your module uses one of those, every user of your module has to use it,	91	uses one of those, every user of your module has to use it, too. But if
87	too. But if your module uses AnyEvent, it works transparently with all	92	your module uses AnyEvent, it works transparently with all event models it
88	event models it supports (including stuff like IO::Async, as long as those	93	supports (including stuff like IO::Async, as long as those use one of the
89	use one of the supported event loops. It is trivial to add new event loops	94	supported event loops. It is easy to add new event loops to AnyEvent, too,
90	to AnyEvent, too, so it is future-proof).	95	so it is future-proof).
91		96
92	In addition to being free of having to use I<the one and only true event	97	In addition to being free of having to use I<the one and only true event
93	model>, AnyEvent also is free of bloat and policy: with POE or similar	98	model>, AnyEvent also is free of bloat and policy: with POE or similar
94	modules, you get an enormous amount of code and strict rules you have to	99	modules, you get an enormous amount of code and strict rules you have to
95	follow. AnyEvent, on the other hand, is lean and up to the point, by only	100	follow. AnyEvent, on the other hand, is lean and to the point, by only
96	offering the functionality that is necessary, in as thin as a wrapper as	101	offering the functionality that is necessary, in as thin as a wrapper as
97	technically possible.	102	technically possible.
98		103
99	Of course, AnyEvent comes with a big (and fully optional!) toolbox	104	Of course, AnyEvent comes with a big (and fully optional!) toolbox
100	of useful functionality, such as an asynchronous DNS resolver, 100%	105	of useful functionality, such as an asynchronous DNS resolver, 100%
…		…
106	useful) and you want to force your users to use the one and only event	111	useful) and you want to force your users to use the one and only event
107	model, you should I<not> use this module.	112	model, you should I<not> use this module.
108		113
109	=head1 DESCRIPTION	114	=head1 DESCRIPTION
110		115
111	L<AnyEvent> provides an identical interface to multiple event loops. This	116	L<AnyEvent> provides a uniform interface to various event loops. This
112	allows module authors to utilise an event loop without forcing module	117	allows module authors to use event loop functionality without forcing
113	users to use the same event loop (as only a single event loop can coexist	118	module users to use a specific event loop implementation (since more
114	peacefully at any one time).	119	than one event loop cannot coexist peacefully).
115		120
116	The interface itself is vaguely similar, but not identical to the L<Event>	121	The interface itself is vaguely similar, but not identical to the L<Event>
117	module.	122	module.
118		123
119	During the first call of any watcher-creation method, the module tries	124	During the first call of any watcher-creation method, the module tries
120	to detect the currently loaded event loop by probing whether one of the	125	to detect the currently loaded event loop by probing whether one of the
121	following modules is already loaded: L<EV>,	126	following modules is already loaded: L<EV>, L<AnyEvent::Loop>,
122	L<Event>, L<Glib>, L<AnyEvent::Impl::Perl>, L<Tk>, L<Event::Lib>, L<Qt>,	127	L<Event>, L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>. The first one
123	L<POE>. The first one found is used. If none are found, the module tries	128	found is used. If none are detected, the module tries to load the first
124	to load these modules (excluding Tk, Event::Lib, Qt and POE as the pure perl	129	four modules in the order given; but note that if L<EV> is not
125	adaptor should always succeed) in the order given. The first one that can	130	available, the pure-perl L<AnyEvent::Loop> should always work, so
126	be successfully loaded will be used. If, after this, still none could be	131	the other two are not normally tried.
127	found, AnyEvent will fall back to a pure-perl event loop, which is not
128	very efficient, but should work everywhere.
129		132
130	Because AnyEvent first checks for modules that are already loaded, loading	133	Because AnyEvent first checks for modules that are already loaded, loading
131	an event model explicitly before first using AnyEvent will likely make	134	an event model explicitly before first using AnyEvent will likely make
132	that model the default. For example:	135	that model the default. For example:
133		136
…		…
135	use AnyEvent;	138	use AnyEvent;
136		139
137	# .. AnyEvent will likely default to Tk	140	# .. AnyEvent will likely default to Tk
138		141
139	The I<likely> means that, if any module loads another event model and	142	The I<likely> means that, if any module loads another event model and
140	starts using it, all bets are off. Maybe you should tell their authors to	143	starts using it, all bets are off - this case should be very rare though,
141	use AnyEvent so their modules work together with others seamlessly...	144	as very few modules hardcode event loops without announcing this very
		145	loudly.
142		146
143	The pure-perl implementation of AnyEvent is called	147	The pure-perl implementation of AnyEvent is called C<AnyEvent::Loop>. Like
144	C<AnyEvent::Impl::Perl>. Like other event modules you can load it	148	other event modules you can load it explicitly and enjoy the high
145	explicitly and enjoy the high availability of that event loop :)	149	availability of that event loop :)
146		150
147	=head1 WATCHERS	151	=head1 WATCHERS
148		152
149	AnyEvent has the central concept of a I<watcher>, which is an object that	153	AnyEvent has the central concept of a I<watcher>, which is an object that
150	stores relevant data for each kind of event you are waiting for, such as	154	stores relevant data for each kind of event you are waiting for, such as
…		…
155	callback when the event occurs (of course, only when the event model	159	callback when the event occurs (of course, only when the event model
156	is in control).	160	is in control).
157		161
158	Note that B<callbacks must not permanently change global variables>	162	Note that B<callbacks must not permanently change global variables>
159	potentially in use by the event loop (such as C<$_> or C<$[>) and that B<<	163	potentially in use by the event loop (such as C<$_> or C<$[>) and that B<<
160	callbacks must not C<die> >>. The former is good programming practise in	164	callbacks must not C<die> >>. The former is good programming practice in
161	Perl and the latter stems from the fact that exception handling differs	165	Perl and the latter stems from the fact that exception handling differs
162	widely between event loops.	166	widely between event loops.
163		167
164	To disable the watcher you have to destroy it (e.g. by setting the	168	To disable a watcher you have to destroy it (e.g. by setting the
165	variable you store it in to C<undef> or otherwise deleting all references	169	variable you store it in to C<undef> or otherwise deleting all references
166	to it).	170	to it).
167		171
168	All watchers are created by calling a method on the C<AnyEvent> class.	172	All watchers are created by calling a method on the C<AnyEvent> class.
169		173
170	Many watchers either are used with "recursion" (repeating timers for	174	Many watchers either are used with "recursion" (repeating timers for
171	example), or need to refer to their watcher object in other ways.	175	example), or need to refer to their watcher object in other ways.
172		176
173	An any way to achieve that is this pattern:	177	One way to achieve that is this pattern:
174		178
175	my $w; $w = AnyEvent->type (arg => value ..., cb => sub {	179	my $w; $w = AnyEvent->type (arg => value ..., cb => sub {
176	# you can use $w here, for example to undef it	180	# you can use $w here, for example to undef it
177	undef $w;	181	undef $w;
178	});	182	});
…		…
210		214
211	The I/O watcher might use the underlying file descriptor or a copy of it.	215	The I/O watcher might use the underlying file descriptor or a copy of it.
212	You must not close a file handle as long as any watcher is active on the	216	You must not close a file handle as long as any watcher is active on the
213	underlying file descriptor.	217	underlying file descriptor.
214		218
215	Some event loops issue spurious readyness notifications, so you should	219	Some event loops issue spurious readiness notifications, so you should
216	always use non-blocking calls when reading/writing from/to your file	220	always use non-blocking calls when reading/writing from/to your file
217	handles.	221	handles.
218		222
219	Example: wait for readability of STDIN, then read a line and disable the	223	Example: wait for readability of STDIN, then read a line and disable the
220	watcher.	224	watcher.
…		…
244		248
245	Although the callback might get passed parameters, their value and	249	Although the callback might get passed parameters, their value and
246	presence is undefined and you cannot rely on them. Portable AnyEvent	250	presence is undefined and you cannot rely on them. Portable AnyEvent
247	callbacks cannot use arguments passed to time watcher callbacks.	251	callbacks cannot use arguments passed to time watcher callbacks.
248		252
249	The callback will normally be invoked once only. If you specify another	253	The callback will normally be invoked only once. If you specify another
250	parameter, C<interval>, as a strictly positive number (> 0), then the	254	parameter, C<interval>, as a strictly positive number (> 0), then the
251	callback will be invoked regularly at that interval (in fractional	255	callback will be invoked regularly at that interval (in fractional
252	seconds) after the first invocation. If C<interval> is specified with a	256	seconds) after the first invocation. If C<interval> is specified with a
253	false value, then it is treated as if it were missing.	257	false value, then it is treated as if it were not specified at all.
254		258
255	The callback will be rescheduled before invoking the callback, but no	259	The callback will be rescheduled before invoking the callback, but no
256	attempt is done to avoid timer drift in most backends, so the interval is	260	attempt is made to avoid timer drift in most backends, so the interval is
257	only approximate.	261	only approximate.
258		262
259	Example: fire an event after 7.7 seconds.	263	Example: fire an event after 7.7 seconds.
260		264
261	my $w = AnyEvent->timer (after => 7.7, cb => sub {	265	my $w = AnyEvent->timer (after => 7.7, cb => sub {
…		…
279		283
280	While most event loops expect timers to specified in a relative way, they	284	While most event loops expect timers to specified in a relative way, they
281	use absolute time internally. This makes a difference when your clock	285	use absolute time internally. This makes a difference when your clock
282	"jumps", for example, when ntp decides to set your clock backwards from	286	"jumps", for example, when ntp decides to set your clock backwards from
283	the wrong date of 2014-01-01 to 2008-01-01, a watcher that is supposed to	287	the wrong date of 2014-01-01 to 2008-01-01, a watcher that is supposed to
284	fire "after" a second might actually take six years to finally fire.	288	fire "after a second" might actually take six years to finally fire.
285		289
286	AnyEvent cannot compensate for this. The only event loop that is conscious	290	AnyEvent cannot compensate for this. The only event loop that is conscious
287	about these issues is L<EV>, which offers both relative (ev_timer, based	291	of these issues is L<EV>, which offers both relative (ev_timer, based
288	on true relative time) and absolute (ev_periodic, based on wallclock time)	292	on true relative time) and absolute (ev_periodic, based on wallclock time)
289	timers.	293	timers.
290		294
291	AnyEvent always prefers relative timers, if available, matching the	295	AnyEvent always prefers relative timers, if available, matching the
292	AnyEvent API.	296	AnyEvent API.
…		…
314	I<In almost all cases (in all cases if you don't care), this is the	318	I<In almost all cases (in all cases if you don't care), this is the
315	function to call when you want to know the current time.>	319	function to call when you want to know the current time.>
316		320
317	This function is also often faster then C<< AnyEvent->time >>, and	321	This function is also often faster then C<< AnyEvent->time >>, and
318	thus the preferred method if you want some timestamp (for example,	322	thus the preferred method if you want some timestamp (for example,
319	L<AnyEvent::Handle> uses this to update it's activity timeouts).	323	L<AnyEvent::Handle> uses this to update its activity timeouts).
320		324
321	The rest of this section is only of relevance if you try to be very exact	325	The rest of this section is only of relevance if you try to be very exact
322	with your timing, you can skip it without bad conscience.	326	with your timing; you can skip it without a bad conscience.
323		327
324	For a practical example of when these times differ, consider L<Event::Lib>	328	For a practical example of when these times differ, consider L<Event::Lib>
325	and L<EV> and the following set-up:	329	and L<EV> and the following set-up:
326		330
327	The event loop is running and has just invoked one of your callback at	331	The event loop is running and has just invoked one of your callbacks at
328	time=500 (assume no other callbacks delay processing). In your callback,	332	time=500 (assume no other callbacks delay processing). In your callback,
329	you wait a second by executing C<sleep 1> (blocking the process for a	333	you wait a second by executing C<sleep 1> (blocking the process for a
330	second) and then (at time=501) you create a relative timer that fires	334	second) and then (at time=501) you create a relative timer that fires
331	after three seconds.	335	after three seconds.
332		336
…		…
352	difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into	356	difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into
353	account.	357	account.
354		358
355	=item AnyEvent->now_update	359	=item AnyEvent->now_update
356		360
357	Some event loops (such as L<EV> or L<AnyEvent::Impl::Perl>) cache	361	Some event loops (such as L<EV> or L<AnyEvent::Loop>) cache the current
358	the current time for each loop iteration (see the discussion of L<<	362	time for each loop iteration (see the discussion of L<< AnyEvent->now >>,
359	AnyEvent->now >>, above).	363	above).
360		364
361	When a callback runs for a long time (or when the process sleeps), then	365	When a callback runs for a long time (or when the process sleeps), then
362	this "current" time will differ substantially from the real time, which	366	this "current" time will differ substantially from the real time, which
363	might affect timers and time-outs.	367	might affect timers and time-outs.
364		368
365	When this is the case, you can call this method, which will update the	369	When this is the case, you can call this method, which will update the
366	event loop's idea of "current time".	370	event loop's idea of "current time".
		371
		372	A typical example would be a script in a web server (e.g. C<mod_perl>) -
		373	when mod_perl executes the script, then the event loop will have the wrong
		374	idea about the "current time" (being potentially far in the past, when the
		375	script ran the last time). In that case you should arrange a call to C<<
		376	AnyEvent->now_update >> each time the web server process wakes up again
		377	(e.g. at the start of your script, or in a handler).
367		378
368	Note that updating the time I<might> cause some events to be handled.	379	Note that updating the time I<might> cause some events to be handled.
369		380
370	=back	381	=back
371		382
…		…
396		407
397	Example: exit on SIGINT	408	Example: exit on SIGINT
398		409
399	my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });	410	my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });
400		411
		412	=head3 Restart Behaviour
		413
		414	While restart behaviour is up to the event loop implementation, most will
		415	not restart syscalls (that includes L<Async::Interrupt> and AnyEvent's
		416	pure perl implementation).
		417
		418	=head3 Safe/Unsafe Signals
		419
		420	Perl signals can be either "safe" (synchronous to opcode handling)
		421	or "unsafe" (asynchronous) - the former might delay signal delivery
		422	indefinitely, the latter might corrupt your memory.
		423
		424	AnyEvent signal handlers are, in addition, synchronous to the event loop,
		425	i.e. they will not interrupt your running perl program but will only be
		426	called as part of the normal event handling (just like timer, I/O etc.
		427	callbacks, too).
		428
401	=head3 Signal Races, Delays and Workarounds	429	=head3 Signal Races, Delays and Workarounds
402		430
403	Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support attaching	431	Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support
404	callbacks to signals in a generic way, which is a pity, as you cannot	432	attaching callbacks to signals in a generic way, which is a pity,
405	do race-free signal handling in perl, requiring C libraries for	433	as you cannot do race-free signal handling in perl, requiring
406	this. AnyEvent will try to do it's best, which means in some cases,	434	C libraries for this. AnyEvent will try to do its best, which
407	signals will be delayed. The maximum time a signal might be delayed is	435	means in some cases, signals will be delayed. The maximum time
408	specified in C<$AnyEvent::MAX_SIGNAL_LATENCY> (default: 10 seconds). This	436	a signal might be delayed is 10 seconds by default, but can
409	variable can be changed only before the first signal watcher is created,	437	be overriden via C<$ENV{PERL_ANYEVENT_MAX_SIGNAL_LATENCY}> or
410	and should be left alone otherwise. This variable determines how often	438	C<$AnyEvent::MAX_SIGNAL_LATENCY> - see the Ö<ENVIRONMENT VARIABLES>
411	AnyEvent polls for signals (in case a wake-up was missed). Higher values	439	section for details.
412	will cause fewer spurious wake-ups, which is better for power and CPU
413	saving.
414		440
415	All these problems can be avoided by installing the optional	441	All these problems can be avoided by installing the optional
416	L<Async::Interrupt> module, which works with most event loops. It will not	442	L<Async::Interrupt> module, which works with most event loops. It will not
417	work with inherently broken event loops such as L<Event> or L<Event::Lib>	443	work with inherently broken event loops such as L<Event> or L<Event::Lib>
418	(and not with L<POE> currently, as POE does it's own workaround with	444	(and not with L<POE> currently). For those, you just have to suffer the
419	one-second latency). For those, you just have to suffer the delays.	445	delays.
420		446
421	=head2 CHILD PROCESS WATCHERS	447	=head2 CHILD PROCESS WATCHERS
422		448
423	$w = AnyEvent->child (pid => <process id>, cb => <callback>);	449	$w = AnyEvent->child (pid => <process id>, cb => <callback>);
424		450
425	You can also watch on a child process exit and catch its exit status.	451	You can also watch for a child process exit and catch its exit status.
426		452
427	The child process is specified by the C<pid> argument (one some backends,	453	The child process is specified by the C<pid> argument (on some backends,
428	using C<0> watches for any child process exit, on others this will	454	using C<0> watches for any child process exit, on others this will
429	croak). The watcher will be triggered only when the child process has	455	croak). The watcher will be triggered only when the child process has
430	finished and an exit status is available, not on any trace events	456	finished and an exit status is available, not on any trace events
431	(stopped/continued).	457	(stopped/continued).
432		458
…		…
454	thing in an AnyEvent program, you I<have> to create at least one	480	thing in an AnyEvent program, you I<have> to create at least one
455	watcher before you C<fork> the child (alternatively, you can call	481	watcher before you C<fork> the child (alternatively, you can call
456	C<AnyEvent::detect>).	482	C<AnyEvent::detect>).
457		483
458	As most event loops do not support waiting for child events, they will be	484	As most event loops do not support waiting for child events, they will be
459	emulated by AnyEvent in most cases, in which the latency and race problems	485	emulated by AnyEvent in most cases, in which case the latency and race
460	mentioned in the description of signal watchers apply.	486	problems mentioned in the description of signal watchers apply.
461		487
462	Example: fork a process and wait for it	488	Example: fork a process and wait for it
463		489
464	my $done = AnyEvent->condvar;	490	my $done = AnyEvent->condvar;
465		491
…		…
479		505
480	=head2 IDLE WATCHERS	506	=head2 IDLE WATCHERS
481		507
482	$w = AnyEvent->idle (cb => <callback>);	508	$w = AnyEvent->idle (cb => <callback>);
483		509
484	Sometimes there is a need to do something, but it is not so important	510	This will repeatedly invoke the callback after the process becomes idle,
485	to do it instantly, but only when there is nothing better to do. This	511	until either the watcher is destroyed or new events have been detected.
486	"nothing better to do" is usually defined to be "no other events need
487	attention by the event loop".
488		512
489	Idle watchers ideally get invoked when the event loop has nothing	513	Idle watchers are useful when there is a need to do something, but it
490	better to do, just before it would block the process to wait for new	514	is not so important (or wise) to do it instantly. The callback will be
491	events. Instead of blocking, the idle watcher is invoked.	515	invoked only when there is "nothing better to do", which is usually
		516	defined as "all outstanding events have been handled and no new events
		517	have been detected". That means that idle watchers ideally get invoked
		518	when the event loop has just polled for new events but none have been
		519	detected. Instead of blocking to wait for more events, the idle watchers
		520	will be invoked.
492		521
493	Most event loops unfortunately do not really support idle watchers (only	522	Unfortunately, most event loops do not really support idle watchers (only
494	EV, Event and Glib do it in a usable fashion) - for the rest, AnyEvent	523	EV, Event and Glib do it in a usable fashion) - for the rest, AnyEvent
495	will simply call the callback "from time to time".	524	will simply call the callback "from time to time".
496		525
497	Example: read lines from STDIN, but only process them when the	526	Example: read lines from STDIN, but only process them when the
498	program is otherwise idle:	527	program is otherwise idle:
…		…
526	will actively watch for new events and call your callbacks.	555	will actively watch for new events and call your callbacks.
527		556
528	AnyEvent is slightly different: it expects somebody else to run the event	557	AnyEvent is slightly different: it expects somebody else to run the event
529	loop and will only block when necessary (usually when told by the user).	558	loop and will only block when necessary (usually when told by the user).
530		559
531	The instrument to do that is called a "condition variable", so called	560	The tool to do that is called a "condition variable", so called because
532	because they represent a condition that must become true.	561	they represent a condition that must become true.
533		562
534	Now is probably a good time to look at the examples further below.	563	Now is probably a good time to look at the examples further below.
535		564
536	Condition variables can be created by calling the C<< AnyEvent->condvar	565	Condition variables can be created by calling the C<< AnyEvent->condvar
537	>> method, usually without arguments. The only argument pair allowed is	566	>> method, usually without arguments. The only argument pair allowed is
…		…
542	After creation, the condition variable is "false" until it becomes "true"	571	After creation, the condition variable is "false" until it becomes "true"
543	by calling the C<send> method (or calling the condition variable as if it	572	by calling the C<send> method (or calling the condition variable as if it
544	were a callback, read about the caveats in the description for the C<<	573	were a callback, read about the caveats in the description for the C<<
545	->send >> method).	574	->send >> method).
546		575
547	Condition variables are similar to callbacks, except that you can	576	Since condition variables are the most complex part of the AnyEvent API, here are
548	optionally wait for them. They can also be called merge points - points	577	some different mental models of what they are - pick the ones you can connect to:
549	in time where multiple outstanding events have been processed. And yet	578
550	another way to call them is transactions - each condition variable can be	579	=over 4
551	used to represent a transaction, which finishes at some point and delivers	580
552	a result. And yet some people know them as "futures" - a promise to	581	=item * Condition variables are like callbacks - you can call them (and pass them instead
553	compute/deliver something that you can wait for.	582	of callbacks). Unlike callbacks however, you can also wait for them to be called.
		583
		584	=item * Condition variables are signals - one side can emit or send them,
		585	the other side can wait for them, or install a handler that is called when
		586	the signal fires.
		587
		588	=item * Condition variables are like "Merge Points" - points in your program
		589	where you merge multiple independent results/control flows into one.
		590
		591	=item * Condition variables represent a transaction - functions that start
		592	some kind of transaction can return them, leaving the caller the choice
		593	between waiting in a blocking fashion, or setting a callback.
		594
		595	=item * Condition variables represent future values, or promises to deliver
		596	some result, long before the result is available.
		597
		598	=back
554		599
555	Condition variables are very useful to signal that something has finished,	600	Condition variables are very useful to signal that something has finished,
556	for example, if you write a module that does asynchronous http requests,	601	for example, if you write a module that does asynchronous http requests,
557	then a condition variable would be the ideal candidate to signal the	602	then a condition variable would be the ideal candidate to signal the
558	availability of results. The user can either act when the callback is	603	availability of results. The user can either act when the callback is
…		…
571		616
572	Condition variables are represented by hash refs in perl, and the keys	617	Condition variables are represented by hash refs in perl, and the keys
573	used by AnyEvent itself are all named C<_ae_XXX> to make subclassing	618	used by AnyEvent itself are all named C<_ae_XXX> to make subclassing
574	easy (it is often useful to build your own transaction class on top of	619	easy (it is often useful to build your own transaction class on top of
575	AnyEvent). To subclass, use C<AnyEvent::CondVar> as base class and call	620	AnyEvent). To subclass, use C<AnyEvent::CondVar> as base class and call
576	it's C<new> method in your own C<new> method.	621	its C<new> method in your own C<new> method.
577		622
578	There are two "sides" to a condition variable - the "producer side" which	623	There are two "sides" to a condition variable - the "producer side" which
579	eventually calls C<< -> send >>, and the "consumer side", which waits	624	eventually calls C<< -> send >>, and the "consumer side", which waits
580	for the send to occur.	625	for the send to occur.
581		626
582	Example: wait for a timer.	627	Example: wait for a timer.
583		628
584	# wait till the result is ready	629	# condition: "wait till the timer is fired"
585	my $result_ready = AnyEvent->condvar;	630	my $timer_fired = AnyEvent->condvar;
586		631
587	# do something such as adding a timer	632	# create the timer - we could wait for, say
588	# or socket watcher the calls $result_ready->send	633	# a handle becomign ready, or even an
589	# when the "result" is ready.	634	# AnyEvent::HTTP request to finish, but
590	# in this case, we simply use a timer:	635	# in this case, we simply use a timer:
591	my $w = AnyEvent->timer (	636	my $w = AnyEvent->timer (
592	after => 1,	637	after => 1,
593	cb => sub { $result_ready->send },	638	cb => sub { $timer_fired->send },
594	);	639	);
595		640
596	# this "blocks" (while handling events) till the callback	641	# this "blocks" (while handling events) till the callback
597	# calls -<send	642	# calls ->send
598	$result_ready->recv;	643	$timer_fired->recv;
599		644
600	Example: wait for a timer, but take advantage of the fact that condition	645	Example: wait for a timer, but take advantage of the fact that condition
601	variables are also callable directly.	646	variables are also callable directly.
602		647
603	my $done = AnyEvent->condvar;	648	my $done = AnyEvent->condvar;
…		…
646	they were a code reference). Calling them directly is the same as calling	691	they were a code reference). Calling them directly is the same as calling
647	C<send>.	692	C<send>.
648		693
649	=item $cv->croak ($error)	694	=item $cv->croak ($error)
650		695
651	Similar to send, but causes all call's to C<< ->recv >> to invoke	696	Similar to send, but causes all calls to C<< ->recv >> to invoke
652	C<Carp::croak> with the given error message/object/scalar.	697	C<Carp::croak> with the given error message/object/scalar.
653		698
654	This can be used to signal any errors to the condition variable	699	This can be used to signal any errors to the condition variable
655	user/consumer. Doing it this way instead of calling C<croak> directly	700	user/consumer. Doing it this way instead of calling C<croak> directly
656	delays the error detetcion, but has the overwhelmign advantage that it	701	delays the error detection, but has the overwhelming advantage that it
657	diagnoses the error at the place where the result is expected, and not	702	diagnoses the error at the place where the result is expected, and not
658	deep in some event clalback without connection to the actual code causing	703	deep in some event callback with no connection to the actual code causing
659	the problem.	704	the problem.
660		705
661	=item $cv->begin ([group callback])	706	=item $cv->begin ([group callback])
662		707
663	=item $cv->end	708	=item $cv->end
…		…
666	one. For example, a function that pings many hosts in parallel might want	711	one. For example, a function that pings many hosts in parallel might want
667	to use a condition variable for the whole process.	712	to use a condition variable for the whole process.
668		713
669	Every call to C<< ->begin >> will increment a counter, and every call to	714	Every call to C<< ->begin >> will increment a counter, and every call to
670	C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end	715	C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end
671	>>, the (last) callback passed to C<begin> will be executed. That callback	716	>>, the (last) callback passed to C<begin> will be executed, passing the
672	is I<supposed> to call C<< ->send >>, but that is not required. If no	717	condvar as first argument. That callback is I<supposed> to call C<< ->send
673	callback was set, C<send> will be called without any arguments.	718	>>, but that is not required. If no group callback was set, C<send> will
		719	be called without any arguments.
674		720
675	You can think of C<< $cv->send >> giving you an OR condition (one call	721	You can think of C<< $cv->send >> giving you an OR condition (one call
676	sends), while C<< $cv->begin >> and C<< $cv->end >> giving you an AND	722	sends), while C<< $cv->begin >> and C<< $cv->end >> giving you an AND
677	condition (all C<begin> calls must be C<end>'ed before the condvar sends).	723	condition (all C<begin> calls must be C<end>'ed before the condvar sends).
678		724
…		…
700	one call to C<begin>, so the condvar waits for all calls to C<end> before	746	one call to C<begin>, so the condvar waits for all calls to C<end> before
701	sending.	747	sending.
702		748
703	The ping example mentioned above is slightly more complicated, as the	749	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	750	there are results to be passwd back, and the number of tasks that are
705	begung can potentially be zero:	751	begun can potentially be zero:
706		752
707	my $cv = AnyEvent->condvar;	753	my $cv = AnyEvent->condvar;
708		754
709	my %result;	755	my %result;
710	$cv->begin (sub { $cv->send (\%result) });	756	$cv->begin (sub { shift->send (\%result) });
711		757
712	for my $host (@list_of_hosts) {	758	for my $host (@list_of_hosts) {
713	$cv->begin;	759	$cv->begin;
714	ping_host_then_call_callback $host, sub {	760	ping_host_then_call_callback $host, sub {
715	$result{$host} = ...;	761	$result{$host} = ...;
…		…
731	to be called once the counter reaches C<0>, and second, it ensures that	777	to be called once the counter reaches C<0>, and second, it ensures that
732	C<send> is called even when C<no> hosts are being pinged (the loop	778	C<send> is called even when C<no> hosts are being pinged (the loop
733	doesn't execute once).	779	doesn't execute once).
734		780
735	This is the general pattern when you "fan out" into multiple (but	781	This is the general pattern when you "fan out" into multiple (but
736	potentially none) subrequests: use an outer C<begin>/C<end> pair to set	782	potentially zero) subrequests: use an outer C<begin>/C<end> pair to set
737	the callback and ensure C<end> is called at least once, and then, for each	783	the callback and ensure C<end> is called at least once, and then, for each
738	subrequest you start, call C<begin> and for each subrequest you finish,	784	subrequest you start, call C<begin> and for each subrequest you finish,
739	call C<end>.	785	call C<end>.
740		786
741	=back	787	=back
…		…
748	=over 4	794	=over 4
749		795
750	=item $cv->recv	796	=item $cv->recv
751		797
752	Wait (blocking if necessary) until the C<< ->send >> or C<< ->croak	798	Wait (blocking if necessary) until the C<< ->send >> or C<< ->croak
753	>> methods have been called on c<$cv>, while servicing other watchers	799	>> methods have been called on C<$cv>, while servicing other watchers
754	normally.	800	normally.
755		801
756	You can only wait once on a condition - additional calls are valid but	802	You can only wait once on a condition - additional calls are valid but
757	will return immediately.	803	will return immediately.
758		804
…		…
775	caller decide whether the call will block or not (for example, by coupling	821	caller decide whether the call will block or not (for example, by coupling
776	condition variables with some kind of request results and supporting	822	condition variables with some kind of request results and supporting
777	callbacks so the caller knows that getting the result will not block,	823	callbacks so the caller knows that getting the result will not block,
778	while still supporting blocking waits if the caller so desires).	824	while still supporting blocking waits if the caller so desires).
779		825
780	You can ensure that C<< -recv >> never blocks by setting a callback and	826	You can ensure that C<< ->recv >> never blocks by setting a callback and
781	only calling C<< ->recv >> from within that callback (or at a later	827	only calling C<< ->recv >> from within that callback (or at a later
782	time). This will work even when the event loop does not support blocking	828	time). This will work even when the event loop does not support blocking
783	waits otherwise.	829	waits otherwise.
784		830
785	=item $bool = $cv->ready	831	=item $bool = $cv->ready
…		…
790	=item $cb = $cv->cb ($cb->($cv))	836	=item $cb = $cv->cb ($cb->($cv))
791		837
792	This is a mutator function that returns the callback set and optionally	838	This is a mutator function that returns the callback set and optionally
793	replaces it before doing so.	839	replaces it before doing so.
794		840
795	The callback will be called when the condition becomes (or already was)	841	The callback will be called when the condition becomes "true", i.e. when
796	"true", i.e. when C<send> or C<croak> are called (or were called), with	842	C<send> or C<croak> are called, with the only argument being the
797	the only argument being the condition variable itself. Calling C<recv>	843	condition variable itself. If the condition is already true, the
		844	callback is called immediately when it is set. Calling C<recv> inside
798	inside the callback or at any later time is guaranteed not to block.	845	the callback or at any later time is guaranteed not to block.
799		846
800	=back	847	=back
801		848
802	=head1 SUPPORTED EVENT LOOPS/BACKENDS	849	=head1 SUPPORTED EVENT LOOPS/BACKENDS
803		850
…		…
806	=over 4	853	=over 4
807		854
808	=item Backends that are autoprobed when no other event loop can be found.	855	=item Backends that are autoprobed when no other event loop can be found.
809		856
810	EV is the preferred backend when no other event loop seems to be in	857	EV is the preferred backend when no other event loop seems to be in
811	use. If EV is not installed, then AnyEvent will try Event, and, failing	858	use. If EV is not installed, then AnyEvent will fall back to its own
812	that, will fall back to its own pure-perl implementation, which is	859	pure-perl implementation, which is available everywhere as it comes with
813	available everywhere as it comes with AnyEvent itself.	860	AnyEvent itself.
814		861
815	AnyEvent::Impl::EV based on EV (interface to libev, best choice).	862	AnyEvent::Impl::EV based on EV (interface to libev, best choice).
816	AnyEvent::Impl::Event based on Event, very stable, few glitches.
817	AnyEvent::Impl::Perl pure-perl implementation, fast and portable.	863	AnyEvent::Impl::Perl pure-perl AnyEvent::Loop, fast and portable.
818		864
819	=item Backends that are transparently being picked up when they are used.	865	=item Backends that are transparently being picked up when they are used.
820		866
821	These will be used when they are currently loaded when the first watcher	867	These will be used if they are already loaded when the first watcher
822	is created, in which case it is assumed that the application is using	868	is created, in which case it is assumed that the application is using
823	them. This means that AnyEvent will automatically pick the right backend	869	them. This means that AnyEvent will automatically pick the right backend
824	when the main program loads an event module before anything starts to	870	when the main program loads an event module before anything starts to
825	create watchers. Nothing special needs to be done by the main program.	871	create watchers. Nothing special needs to be done by the main program.
826		872
		873	AnyEvent::Impl::Event based on Event, very stable, few glitches.
827	AnyEvent::Impl::Glib based on Glib, slow but very stable.	874	AnyEvent::Impl::Glib based on Glib, slow but very stable.
828	AnyEvent::Impl::Tk based on Tk, very broken.	875	AnyEvent::Impl::Tk based on Tk, very broken.
829	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.	876	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
830	AnyEvent::Impl::POE based on POE, very slow, some limitations.	877	AnyEvent::Impl::POE based on POE, very slow, some limitations.
831	AnyEvent::Impl::Irssi used when running within irssi.	878	AnyEvent::Impl::Irssi used when running within irssi.
		879	AnyEvent::Impl::IOAsync based on IO::Async.
		880	AnyEvent::Impl::Cocoa based on Cocoa::EventLoop.
		881	AnyEvent::Impl::FLTK based on FLTK (fltk 2 binding).
832		882
833	=item Backends with special needs.	883	=item Backends with special needs.
834		884
835	Qt requires the Qt::Application to be instantiated first, but will	885	Qt requires the Qt::Application to be instantiated first, but will
836	otherwise be picked up automatically. As long as the main program	886	otherwise be picked up automatically. As long as the main program
837	instantiates the application before any AnyEvent watchers are created,	887	instantiates the application before any AnyEvent watchers are created,
838	everything should just work.	888	everything should just work.
839		889
840	AnyEvent::Impl::Qt based on Qt.	890	AnyEvent::Impl::Qt based on Qt.
841		891
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.	892	=item Event loops that are indirectly supported via other backends.
851		893
852	Some event loops can be supported via other modules:	894	Some event loops can be supported via other modules:
853		895
854	There is no direct support for WxWidgets (L<Wx>) or L<Prima>.	896	There is no direct support for WxWidgets (L<Wx>) or L<Prima>.
…		…
879	Contains C<undef> until the first watcher is being created, before the	921	Contains C<undef> until the first watcher is being created, before the
880	backend has been autodetected.	922	backend has been autodetected.
881		923
882	Afterwards it contains the event model that is being used, which is the	924	Afterwards it contains the event model that is being used, which is the
883	name of the Perl class implementing the model. This class is usually one	925	name of the Perl class implementing the model. This class is usually one
884	of the C<AnyEvent::Impl:xxx> modules, but can be any other class in the	926	of the C<AnyEvent::Impl::xxx> modules, but can be any other class in the
885	case AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode> it	927	case AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode> it
886	will be C<urxvt::anyevent>).	928	will be C<urxvt::anyevent>).
887		929
888	=item AnyEvent::detect	930	=item AnyEvent::detect
889		931
890	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model	932	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model
891	if necessary. You should only call this function right before you would	933	if necessary. You should only call this function right before you would
892	have created an AnyEvent watcher anyway, that is, as late as possible at	934	have created an AnyEvent watcher anyway, that is, as late as possible at
893	runtime, and not e.g. while initialising of your module.	935	runtime, and not e.g. during initialisation of your module.
		936
		937	The effect of calling this function is as if a watcher had been created
		938	(specifically, actions that happen "when the first watcher is created"
		939	happen when calling detetc as well).
894		940
895	If you need to do some initialisation before AnyEvent watchers are	941	If you need to do some initialisation before AnyEvent watchers are
896	created, use C<post_detect>.	942	created, use C<post_detect>.
897		943
898	=item $guard = AnyEvent::post_detect { BLOCK }	944	=item $guard = AnyEvent::post_detect { BLOCK }
899		945
900	Arranges for the code block to be executed as soon as the event model is	946	Arranges for the code block to be executed as soon as the event model is
901	autodetected (or immediately if this has already happened).	947	autodetected (or immediately if that has already happened).
902		948
903	The block will be executed I<after> the actual backend has been detected	949	The block will be executed I<after> the actual backend has been detected
904	(C<$AnyEvent::MODEL> is set), but I<before> any watchers have been	950	(C<$AnyEvent::MODEL> is set), but I<before> any watchers have been
905	created, so it is possible to e.g. patch C<@AnyEvent::ISA> or do	951	created, so it is possible to e.g. patch C<@AnyEvent::ISA> or do
906	other initialisations - see the sources of L<AnyEvent::Strict> or	952	other initialisations - see the sources of L<AnyEvent::Strict> or
…		…
915	that automatically removes the callback again when it is destroyed (or	961	that automatically removes the callback again when it is destroyed (or
916	C<undef> when the hook was immediately executed). See L<AnyEvent::AIO> for	962	C<undef> when the hook was immediately executed). See L<AnyEvent::AIO> for
917	a case where this is useful.	963	a case where this is useful.
918		964
919	Example: Create a watcher for the IO::AIO module and store it in	965	Example: Create a watcher for the IO::AIO module and store it in
920	C<$WATCHER>. Only do so after the event loop is initialised, though.	966	C<$WATCHER>, but do so only do so after the event loop is initialised.
921		967
922	our WATCHER;	968	our WATCHER;
923		969
924	my $guard = AnyEvent::post_detect {	970	my $guard = AnyEvent::post_detect {
925	$WATCHER = AnyEvent->io (fh => IO::AIO::poll_fileno, poll => 'r', cb => \&IO::AIO::poll_cb);	971	$WATCHER = AnyEvent->io (fh => IO::AIO::poll_fileno, poll => 'r', cb => \&IO::AIO::poll_cb);
…		…
933	$WATCHER ||= $guard;	979	$WATCHER ||= $guard;
934		980
935	=item @AnyEvent::post_detect	981	=item @AnyEvent::post_detect
936		982
937	If there are any code references in this array (you can C<push> to it	983	If there are any code references in this array (you can C<push> to it
938	before or after loading AnyEvent), then they will called directly after	984	before or after loading AnyEvent), then they will be called directly
939	the event loop has been chosen.	985	after the event loop has been chosen.
940		986
941	You should check C<$AnyEvent::MODEL> before adding to this array, though:	987	You should check C<$AnyEvent::MODEL> before adding to this array, though:
942	if it is defined then the event loop has already been detected, and the	988	if it is defined then the event loop has already been detected, and the
943	array will be ignored.	989	array will be ignored.
944		990
945	Best use C<AnyEvent::post_detect { BLOCK }> when your application allows	991	Best use C<AnyEvent::post_detect { BLOCK }> when your application allows
946	it,as it takes care of these details.	992	it, as it takes care of these details.
947		993
948	This variable is mainly useful for modules that can do something useful	994	This variable is mainly useful for modules that can do something useful
949	when AnyEvent is used and thus want to know when it is initialised, but do	995	when AnyEvent is used and thus want to know when it is initialised, but do
950	not need to even load it by default. This array provides the means to hook	996	not need to even load it by default. This array provides the means to hook
951	into AnyEvent passively, without loading it.	997	into AnyEvent passively, without loading it.
952		998
		999	Example: To load Coro::AnyEvent whenever Coro and AnyEvent are used
		1000	together, you could put this into Coro (this is the actual code used by
		1001	Coro to accomplish this):
		1002
		1003	if (defined $AnyEvent::MODEL) {
		1004	# AnyEvent already initialised, so load Coro::AnyEvent
		1005	require Coro::AnyEvent;
		1006	} else {
		1007	# AnyEvent not yet initialised, so make sure to load Coro::AnyEvent
		1008	# as soon as it is
		1009	push @AnyEvent::post_detect, sub { require Coro::AnyEvent };
		1010	}
		1011
		1012	=item AnyEvent::postpone { BLOCK }
		1013
		1014	Arranges for the block to be executed as soon as possible, but not before
		1015	the call itself returns. In practise, the block will be executed just
		1016	before the event loop polls for new events, or shortly afterwards.
		1017
		1018	This function never returns anything (to make the C<return postpone { ...
		1019	}> idiom more useful.
		1020
		1021	To understand the usefulness of this function, consider a function that
		1022	asynchronously does something for you and returns some transaction
		1023	object or guard to let you cancel the operation. For example,
		1024	C<AnyEvent::Socket::tcp_connect>:
		1025
		1026	# start a conenction attempt unless one is active
		1027	$self->{connect_guard} ||= AnyEvent::Socket::tcp_connect "www.example.net", 80, sub {
		1028	delete $self->{connect_guard};
		1029	...
		1030	};
		1031
		1032	Imagine that this function could instantly call the callback, for
		1033	example, because it detects an obvious error such as a negative port
		1034	number. Invoking the callback before the function returns causes problems
		1035	however: the callback will be called and will try to delete the guard
		1036	object. But since the function hasn't returned yet, there is nothing to
		1037	delete. When the function eventually returns it will assign the guard
		1038	object to C<< $self->{connect_guard} >>, where it will likely never be
		1039	deleted, so the program thinks it is still trying to connect.
		1040
		1041	This is where C<AnyEvent::postpone> should be used. Instead of calling the
		1042	callback directly on error:
		1043
		1044	$cb->(undef), return # signal error to callback, BAD!
		1045	if $some_error_condition;
		1046
		1047	It should use C<postpone>:
		1048
		1049	AnyEvent::postpone { $cb->(undef) }, return # signal error to callback, later
		1050	if $some_error_condition;
		1051
		1052	=item AnyEvent::log $level, $msg[, @args]
		1053
		1054	Log the given C<$msg> at the given C<$level>.
		1055
		1056	If L<AnyEvent::Log> is not loaded then this function makes a simple test
		1057	to see whether the message will be logged. If the test succeeds it will
		1058	load AnyEvent::Log and call C<AnyEvent::Log::log> - consequently, look at
		1059	the L<AnyEvent::Log> documentation for details.
		1060
		1061	If the test fails it will simply return. Right now this happens when a
		1062	numerical loglevel is used and it is larger than the level specified via
		1063	C<$ENV{PERL_ANYEVENT_VERBOSE}>.
		1064
		1065	If you want to sprinkle loads of logging calls around your code, consider
		1066	creating a logger callback with the C<AnyEvent::Log::logger> function,
		1067	which can reduce typing, codesize and can reduce the logging overhead
		1068	enourmously.
		1069
953	=back	1070	=back
954		1071
955	=head1 WHAT TO DO IN A MODULE	1072	=head1 WHAT TO DO IN A MODULE
956		1073
957	As a module author, you should C<use AnyEvent> and call AnyEvent methods	1074	As a module author, you should C<use AnyEvent> and call AnyEvent methods
…		…
967	because it will stall the whole program, and the whole point of using	1084	because it will stall the whole program, and the whole point of using
968	events is to stay interactive.	1085	events is to stay interactive.
969		1086
970	It is fine, however, to call C<< ->recv >> when the user of your module	1087	It is fine, however, to call C<< ->recv >> when the user of your module
971	requests it (i.e. if you create a http request object ad have a method	1088	requests it (i.e. if you create a http request object ad have a method
972	called C<results> that returns the results, it should call C<< ->recv >>	1089	called C<results> that returns the results, it may call C<< ->recv >>
973	freely, as the user of your module knows what she is doing. always).	1090	freely, as the user of your module knows what she is doing. Always).
974		1091
975	=head1 WHAT TO DO IN THE MAIN PROGRAM	1092	=head1 WHAT TO DO IN THE MAIN PROGRAM
976		1093
977	There will always be a single main program - the only place that should	1094	There will always be a single main program - the only place that should
978	dictate which event model to use.	1095	dictate which event model to use.
979		1096
980	If it doesn't care, it can just "use AnyEvent" and use it itself, or not	1097	If the program is not event-based, it need not do anything special, even
981	do anything special (it does not need to be event-based) and let AnyEvent	1098	when it depends on a module that uses an AnyEvent. If the program itself
982	decide which implementation to chose if some module relies on it.	1099	uses AnyEvent, but does not care which event loop is used, all it needs
		1100	to do is C<use AnyEvent>. In either case, AnyEvent will choose the best
		1101	available loop implementation.
983		1102
984	If the main program relies on a specific event model - for example, in	1103	If the main program relies on a specific event model - for example, in
985	Gtk2 programs you have to rely on the Glib module - you should load the	1104	Gtk2 programs you have to rely on the Glib module - you should load the
986	event module before loading AnyEvent or any module that uses it: generally	1105	event module before loading AnyEvent or any module that uses it: generally
987	speaking, you should load it as early as possible. The reason is that	1106	speaking, you should load it as early as possible. The reason is that
988	modules might create watchers when they are loaded, and AnyEvent will	1107	modules might create watchers when they are loaded, and AnyEvent will
989	decide on the event model to use as soon as it creates watchers, and it	1108	decide on the event model to use as soon as it creates watchers, and it
990	might chose the wrong one unless you load the correct one yourself.	1109	might choose the wrong one unless you load the correct one yourself.
991		1110
992	You can chose to use a pure-perl implementation by loading the	1111	You can chose to use a pure-perl implementation by loading the
993	C<AnyEvent::Impl::Perl> module, which gives you similar behaviour	1112	C<AnyEvent::Loop> module, which gives you similar behaviour
994	everywhere, but letting AnyEvent chose the model is generally better.	1113	everywhere, but letting AnyEvent chose the model is generally better.
995		1114
996	=head2 MAINLOOP EMULATION	1115	=head2 MAINLOOP EMULATION
997		1116
998	Sometimes (often for short test scripts, or even standalone programs who	1117	Sometimes (often for short test scripts, or even standalone programs who
…		…
1011		1130
1012		1131
1013	=head1 OTHER MODULES	1132	=head1 OTHER MODULES
1014		1133
1015	The following is a non-exhaustive list of additional modules that use	1134	The following is a non-exhaustive list of additional modules that use
1016	AnyEvent as a client and can therefore be mixed easily with other AnyEvent	1135	AnyEvent as a client and can therefore be mixed easily with other
1017	modules and other event loops in the same program. Some of the modules	1136	AnyEvent modules and other event loops in the same program. Some of the
1018	come with AnyEvent, most are available via CPAN.	1137	modules come as part of AnyEvent, the others are available via CPAN (see
		1138	L<http://search.cpan.org/search?m=module&q=anyevent%3A%3A*> for
		1139	a longer non-exhaustive list), and the list is heavily biased towards
		1140	modules of the AnyEvent author himself :)
1019		1141
1020	=over 4	1142	=over 4
1021		1143
1022	=item L<AnyEvent::Util>	1144	=item L<AnyEvent::Util>
1023		1145
1024	Contains various utility functions that replace often-used but blocking	1146	Contains various utility functions that replace often-used blocking
1025	functions such as C<inet_aton> by event-/callback-based versions.	1147	functions such as C<inet_aton> with event/callback-based versions.
1026		1148
1027	=item L<AnyEvent::Socket>	1149	=item L<AnyEvent::Socket>
1028		1150
1029	Provides various utility functions for (internet protocol) sockets,	1151	Provides various utility functions for (internet protocol) sockets,
1030	addresses and name resolution. Also functions to create non-blocking tcp	1152	addresses and name resolution. Also functions to create non-blocking tcp
…		…
1032		1154
1033	=item L<AnyEvent::Handle>	1155	=item L<AnyEvent::Handle>
1034		1156
1035	Provide read and write buffers, manages watchers for reads and writes,	1157	Provide read and write buffers, manages watchers for reads and writes,
1036	supports raw and formatted I/O, I/O queued and fully transparent and	1158	supports raw and formatted I/O, I/O queued and fully transparent and
1037	non-blocking SSL/TLS (via L<AnyEvent::TLS>.	1159	non-blocking SSL/TLS (via L<AnyEvent::TLS>).
1038		1160
1039	=item L<AnyEvent::DNS>	1161	=item L<AnyEvent::DNS>
1040		1162
1041	Provides rich asynchronous DNS resolver capabilities.	1163	Provides rich asynchronous DNS resolver capabilities.
1042		1164
		1165	=item L<AnyEvent::HTTP>, L<AnyEvent::IRC>, L<AnyEvent::XMPP>, L<AnyEvent::GPSD>, L<AnyEvent::IGS>, L<AnyEvent::FCP>
		1166
		1167	Implement event-based interfaces to the protocols of the same name (for
		1168	the curious, IGS is the International Go Server and FCP is the Freenet
		1169	Client Protocol).
		1170
1043	=item L<AnyEvent::HTTP>	1171	=item L<AnyEvent::AIO>
1044		1172
1045	A simple-to-use HTTP library that is capable of making a lot of concurrent	1173	Truly asynchronous (as opposed to non-blocking) I/O, should be in the
1046	HTTP requests.	1174	toolbox of every event programmer. AnyEvent::AIO transparently fuses
		1175	L<IO::AIO> and AnyEvent together, giving AnyEvent access to event-based
		1176	file I/O, and much more.
		1177
		1178	=item L<AnyEvent::Filesys::Notify>
		1179
		1180	AnyEvent is good for non-blocking stuff, but it can't detect file or
		1181	path changes (e.g. "watch this directory for new files", "watch this
		1182	file for changes"). The L<AnyEvent::Filesys::Notify> module promises to
		1183	do just that in a portbale fashion, supporting inotify on GNU/Linux and
		1184	some weird, without doubt broken, stuff on OS X to monitor files. It can
		1185	fall back to blocking scans at regular intervals transparently on other
		1186	platforms, so it's about as portable as it gets.
		1187
		1188	(I haven't used it myself, but I haven't heard anybody complaining about
		1189	it yet).
		1190
		1191	=item L<AnyEvent::DBI>
		1192
		1193	Executes L<DBI> requests asynchronously in a proxy process for you,
		1194	notifying you in an event-based way when the operation is finished.
1047		1195
1048	=item L<AnyEvent::HTTPD>	1196	=item L<AnyEvent::HTTPD>
1049		1197
1050	Provides a simple web application server framework.	1198	A simple embedded webserver.
1051		1199
1052	=item L<AnyEvent::FastPing>	1200	=item L<AnyEvent::FastPing>
1053		1201
1054	The fastest ping in the west.	1202	The fastest ping in the west.
1055		1203
1056	=item L<AnyEvent::DBI>
1057
1058	Executes L<DBI> requests asynchronously in a proxy process.
1059
1060	=item L<AnyEvent::AIO>
1061
1062	Truly asynchronous I/O, should be in the toolbox of every event
1063	programmer. AnyEvent::AIO transparently fuses L<IO::AIO> and AnyEvent
1064	together.
1065
1066	=item L<AnyEvent::BDB>
1067
1068	Truly asynchronous Berkeley DB access. AnyEvent::BDB transparently fuses
1069	L<BDB> and AnyEvent together.
1070
1071	=item L<AnyEvent::GPSD>
1072
1073	A non-blocking interface to gpsd, a daemon delivering GPS information.
1074
1075	=item L<AnyEvent::IRC>
1076
1077	AnyEvent based IRC client module family (replacing the older Net::IRC3).
1078
1079	=item L<AnyEvent::XMPP>
1080
1081	AnyEvent based XMPP (Jabber protocol) module family (replacing the older
1082	Net::XMPP2>.
1083
1084	=item L<AnyEvent::IGS>
1085
1086	A non-blocking interface to the Internet Go Server protocol (used by
1087	L<App::IGS>).
1088
1089	=item L<Net::FCP>
1090
1091	AnyEvent-based implementation of the Freenet Client Protocol, birthplace
1092	of AnyEvent.
1093
1094	=item L<Event::ExecFlow>
1095
1096	High level API for event-based execution flow control.
1097
1098	=item L<Coro>	1204	=item L<Coro>
1099		1205
1100	Has special support for AnyEvent via L<Coro::AnyEvent>.	1206	Has special support for AnyEvent via L<Coro::AnyEvent>, which allows you
		1207	to simply invert the flow control - don't call us, we will call you:
		1208
		1209	async {
		1210	Coro::AnyEvent::sleep 5; # creates a 5s timer and waits for it
		1211	print "5 seconds later!\n";
		1212
		1213	Coro::AnyEvent::readable *STDIN; # uses an I/O watcher
		1214	my $line = <STDIN>; # works for ttys
		1215
		1216	AnyEvent::HTTP::http_get "url", Coro::rouse_cb;
		1217	my ($body, $hdr) = Coro::rouse_wait;
		1218	};
1101		1219
1102	=back	1220	=back
1103		1221
1104	=cut	1222	=cut
1105		1223
1106	package AnyEvent;	1224	package AnyEvent;
1107		1225
1108	# basically a tuned-down version of common::sense	1226	# basically a tuned-down version of common::sense
1109	sub common_sense {	1227	sub common_sense {
1110	# no warnings	1228	# from common:.sense 3.4
1111	${^WARNING_BITS} ^= ${^WARNING_BITS};	1229	${^WARNING_BITS} ^= ${^WARNING_BITS} ^ "\x3c\x3f\x33\x00\x0f\xf0\x0f\xc0\xf0\xfc\x33\x00";
1112	# use strict vars subs	1230	# use strict vars subs - NO UTF-8, as Util.pm doesn't like this atm. (uts46data.pl)
1113	$^H |= 0x00000600;	1231	$^H |= 0x00000600;
1114	}	1232	}
1115		1233
1116	BEGIN { AnyEvent::common_sense }	1234	BEGIN { AnyEvent::common_sense }
1117		1235
1118	use Carp ();	1236	use Carp ();
1119		1237
1120	our $VERSION = 4.901;	1238	our $VERSION = '6.02';
1121	our $MODEL;	1239	our $MODEL;
1122
1123	our $AUTOLOAD;
1124	our @ISA;	1240	our @ISA;
1125
1126	our @REGISTRY;	1241	our @REGISTRY;
1127
1128	our $WIN32;
1129
1130	our $VERBOSE;	1242	our $VERBOSE;
		1243	our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred
		1244	our $MAX_SIGNAL_LATENCY = $ENV{PERL_ANYEVENT_MAX_SIGNAL_LATENCY} || 10; # executes after the BEGIN block below (tainting!)
1131		1245
1132	BEGIN {	1246	BEGIN {
1133	eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }";	1247	require "AnyEvent/constants.pl";
		1248
1134	eval "sub TAINT(){ " . (${^TAINT}*1) . " }";	1249	eval "sub TAINT (){" . (${^TAINT}*1) . "}";
1135		1250
1136	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}	1251	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}
1137	if ${^TAINT};	1252	if ${^TAINT};
1138		1253
1139	$VERBOSE = $ENV{PERL_ANYEVENT_VERBOSE}*1;	1254	$ENV{"PERL_ANYEVENT_$_"} = $ENV{"AE_$_"}
		1255	for grep s/^AE_// && !exists $ENV{"PERL_ANYEVENT_$_"}, keys %ENV;
1140		1256
1141	}	1257	@ENV{grep /^PERL_ANYEVENT_/, keys %ENV} = ()
		1258	if ${^TAINT};
1142		1259
1143	our $MAX_SIGNAL_LATENCY = 10;	1260	# $ENV{PERL_ANYEVENT_xxx} now valid
1144		1261
1145	our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred	1262	$VERBOSE = length $ENV{PERL_ANYEVENT_VERBOSE} ? $ENV{PERL_ANYEVENT_VERBOSE}*1 : 4;
1146		1263
1147	{
1148	my $idx;	1264	my $idx;
1149	$PROTOCOL{$_} = ++$idx	1265	$PROTOCOL{$_} = ++$idx
1150	for reverse split /\s*,\s*/,	1266	for reverse split /\s*,\s*/,
1151	$ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";	1267	$ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";
1152	}	1268	}
1153		1269
		1270	our @post_detect;
		1271
		1272	sub post_detect(&) {
		1273	my ($cb) = @_;
		1274
		1275	push @post_detect, $cb;
		1276
		1277	defined wantarray
		1278	? bless \$cb, "AnyEvent::Util::postdetect"
		1279	: ()
		1280	}
		1281
		1282	sub AnyEvent::Util::postdetect::DESTROY {
		1283	@post_detect = grep $_ != ${$_[0]}, @post_detect;
		1284	}
		1285
		1286	our $POSTPONE_W;
		1287	our @POSTPONE;
		1288
		1289	sub _postpone_exec {
		1290	undef $POSTPONE_W;
		1291
		1292	&{ shift @POSTPONE }
		1293	while @POSTPONE;
		1294	}
		1295
		1296	sub postpone(&) {
		1297	push @POSTPONE, shift;
		1298
		1299	$POSTPONE_W ||= AE::timer (0, 0, \&_postpone_exec);
		1300
		1301	()
		1302	}
		1303
		1304	sub log($$;@) {
		1305	# only load the big bloated module when we actually are about to log something
		1306	if ($_[0] <= ($VERBOSE || 1)) { # also catches non-numeric levels(!) and fatal
		1307	local ($!, $@);
		1308	require AnyEvent::Log; # among other things, sets $VERBOSE to 9
		1309	# AnyEvent::Log overwrites this function
		1310	goto &log;
		1311	}
		1312
		1313	0 # not logged
		1314	}
		1315
		1316	sub logger($;$) {
		1317	package AnyEvent::Log;
		1318
		1319	my ($level, $renabled) = @_;
		1320
		1321	$$renabled = $level <= $VERBOSE;
		1322
		1323	my $pkg = (caller)[0];
		1324
		1325	my $logger = [$pkg, $level, $renabled];
		1326
		1327	our %LOGGER;
		1328	$LOGGER{$logger+0} = $logger;
		1329
		1330	return unless defined wantarray;
		1331
		1332	require AnyEvent::Util;
		1333	my $guard = AnyEvent::Util::guard (sub {
		1334	# "clean up"
		1335	delete $LOGGER{$logger+0};
		1336	});
		1337
		1338	sub {
		1339	return 0 unless $$renabled;
		1340
		1341	$guard if 0; # keep guard alive, but don't cause runtime overhead
		1342	require AnyEvent::Log unless $AnyEvent::Log::VERSION;
		1343	package AnyEvent::Log;
		1344	_log ($logger->[0], $level, @_) # logger->[0] has been converted at load time
		1345	}
		1346	}
		1347
		1348	if (length $ENV{PERL_ANYEVENT_LOG}) {
		1349	require AnyEvent::Log; # AnyEvent::Log does the thing for us
		1350	}
		1351
1154	my @models = (	1352	our @models = (
1155	[EV:: => AnyEvent::Impl::EV:: , 1],	1353	[EV:: => AnyEvent::Impl::EV::],
1156	[Event:: => AnyEvent::Impl::Event::, 1],	1354	[AnyEvent::Loop:: => AnyEvent::Impl::Perl::],
1157	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl:: , 1],
1158	# everything below here will not (normally) be autoprobed	1355	# everything below here will not (normally) be autoprobed
1159	# as the pureperl backend should work everywhere	1356	# as the pure perl backend should work everywhere
1160	# and is usually faster	1357	# and is usually faster
		1358	[Irssi:: => AnyEvent::Impl::Irssi::], # Irssi has a bogus "Event" package, so msut be near the top
		1359	[Event:: => AnyEvent::Impl::Event::], # slow, stable
1161	[Glib:: => AnyEvent::Impl::Glib:: , 1], # becomes extremely slow with many watchers	1360	[Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers
		1361	# everything below here should not be autoloaded
1162	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy	1362	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
1163	[Irssi:: => AnyEvent::Impl::Irssi::], # Irssi has a bogus "Event" package
1164	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles	1363	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
1165	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program	1364	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program
1166	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza	1365	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
1167	[Wx:: => AnyEvent::Impl::POE::],	1366	[Wx:: => AnyEvent::Impl::POE::],
1168	[Prima:: => AnyEvent::Impl::POE::],	1367	[Prima:: => AnyEvent::Impl::POE::],
1169	# IO::Async is just too broken - we would need workarounds for its	1368	[IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # a bitch to autodetect
1170	# byzantine signal and broken child handling, among others.	1369	[Cocoa::EventLoop:: => AnyEvent::Impl::Cocoa::],
1171	# IO::Async is rather hard to detect, as it doesn't have any	1370	[FLTK:: => AnyEvent::Impl::FLTK::],
1172	# obvious default class.
1173	# [0, IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program
1174	# [0, IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program
1175	# [0, IO::Async::Notifier:: => AnyEvent::Impl::IOAsync::], # requires special main program
1176	);	1371	);
1177		1372
1178	our %method = map +($_ => 1),	1373	our @isa_hook;
		1374
		1375	sub _isa_set {
		1376	my @pkg = ("AnyEvent", (map $_->[0], grep defined, @isa_hook), $MODEL);
		1377
		1378	@{"$pkg[$_-1]::ISA"} = $pkg[$_]
		1379	for 1 .. $#pkg;
		1380
		1381	grep $_ && $_->[1], @isa_hook
		1382	and AE::_reset ();
		1383	}
		1384
		1385	# used for hooking AnyEvent::Strict and AnyEvent::Debug::Wrap into the class hierarchy
		1386	sub _isa_hook($$;$) {
		1387	my ($i, $pkg, $reset_ae) = @_;
		1388
		1389	$isa_hook[$i] = $pkg ? [$pkg, $reset_ae] : undef;
		1390
		1391	_isa_set;
		1392	}
		1393
		1394	# all autoloaded methods reserve the complete glob, not just the method slot.
		1395	# due to bugs in perls method cache implementation.
1179	qw(io timer time now now_update signal child idle condvar one_event DESTROY);	1396	our @methods = qw(io timer time now now_update signal child idle condvar);
1180		1397
1181	our @post_detect;
1182
1183	sub post_detect(&) {	1398	sub detect() {
1184	my ($cb) = @_;	1399	return $MODEL if $MODEL; # some programs keep references to detect
1185		1400
1186	if ($MODEL) {	1401	# IO::Async::Loop::AnyEvent is extremely evil, refuse to work with it
1187	$cb->();	1402	# the author knows about the problems and what it does to AnyEvent as a whole
		1403	# (and the ability of others to use AnyEvent), but simply wants to abuse AnyEvent
		1404	# anyway.
		1405	AnyEvent::log fatal => "AnyEvent: IO::Async::Loop::AnyEvent detected - this module is broken by design,\n"
		1406	. "abuses internals and breaks AnyEvent, will not continue."
		1407	if exists $INC{"IO/Async/Loop/AnyEvent.pm"};
1188		1408
1189	undef	1409	local $!; # for good measure
		1410	local $SIG{__DIE__}; # we use eval
		1411
		1412	# free some memory
		1413	*detect = sub () { $MODEL };
		1414	# undef &func doesn't correctly update the method cache. grmbl.
		1415	# so we delete the whole glob. grmbl.
		1416	# otoh, perl doesn't let me undef an active usb, but it lets me free
		1417	# a glob with an active sub. hrm. i hope it works, but perl is
		1418	# usually buggy in this department. sigh.
		1419	delete @{"AnyEvent::"}{@methods};
		1420	undef @methods;
		1421
		1422	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z0-9:]+)$/) {
		1423	my $model = $1;
		1424	$model = "AnyEvent::Impl::$model" unless $model =~ s/::$//;
		1425	if (eval "require $model") {
		1426	AnyEvent::log 7 => "loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.";
		1427	$MODEL = $model;
1190	} else {	1428	} else {
1191	push @post_detect, $cb;	1429	AnyEvent::log 4 => "unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@";
1192		1430	}
1193	defined wantarray
1194	? bless \$cb, "AnyEvent::Util::postdetect"
1195	: ()
1196	}	1431	}
1197	}
1198		1432
1199	sub AnyEvent::Util::postdetect::DESTROY {	1433	# check for already loaded models
1200	@post_detect = grep $_ != ${$_[0]}, @post_detect;
1201	}
1202
1203	sub detect() {
1204	unless ($MODEL) {	1434	unless ($MODEL) {
1205	local $SIG{__DIE__};	1435	for (@REGISTRY, @models) {
1206		1436	my ($package, $model) = @$_;
1207	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {	1437	if (${"$package\::VERSION"} > 0) {
1208	my $model = "AnyEvent::Impl::$1";
1209	if (eval "require $model") {	1438	if (eval "require $model") {
		1439	AnyEvent::log 7 => "autodetected model '$model', using it.";
1210	$MODEL = $model;	1440	$MODEL = $model;
1211	warn "AnyEvent: loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.\n" if $VERBOSE >= 2;	1441	last;
1212	} else {	1442	}
1213	warn "AnyEvent: unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@" if $VERBOSE;
1214	}	1443	}
1215	}	1444	}
1216		1445
1217	# check for already loaded models
1218	unless ($MODEL) {	1446	unless ($MODEL) {
		1447	# try to autoload a model
1219	for (@REGISTRY, @models) {	1448	for (@REGISTRY, @models) {
1220	my ($package, $model) = @$_;	1449	my ($package, $model) = @$_;
		1450	if (
		1451	eval "require $package"
1221	if (${"$package\::VERSION"} > 0) {	1452	and ${"$package\::VERSION"} > 0
1222	if (eval "require $model") {	1453	and eval "require $model"
		1454	) {
		1455	AnyEvent::log 7 => "autoloaded model '$model', using it.";
1223	$MODEL = $model;	1456	$MODEL = $model;
1224	warn "AnyEvent: autodetected model '$model', using it.\n" if $VERBOSE >= 2;
1225	last;	1457	last;
1226	}
1227	}	1458	}
1228	}	1459	}
1229		1460
1230	unless ($MODEL) {
1231	# try to autoload a model
1232	for (@REGISTRY, @models) {
1233	my ($package, $model, $autoload) = @$_;
1234	if (
1235	$autoload
1236	and eval "require $package"
1237	and ${"$package\::VERSION"} > 0
1238	and eval "require $model"
1239	) {
1240	$MODEL = $model;
1241	warn "AnyEvent: autoloaded model '$model', using it.\n" if $VERBOSE >= 2;
1242	last;
1243	}
1244	}
1245
1246	$MODEL	1461	$MODEL
1247	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.\n";	1462	or AnyEvent::log fatal => "AnyEvent: backend autodetection failed - did you properly install AnyEvent?";
1248	}
1249	}	1463	}
1250
1251	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
1252
1253	unshift @ISA, $MODEL;
1254
1255	require AnyEvent::Strict if $ENV{PERL_ANYEVENT_STRICT};
1256
1257	(shift @post_detect)->() while @post_detect;
1258	}	1464	}
1259		1465
		1466	# free memory only needed for probing
		1467	undef @models;
		1468	undef @REGISTRY;
		1469
		1470	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
		1471
		1472	# now nuke some methods that are overridden by the backend.
		1473	# SUPER usage is not allowed in these.
		1474	for (qw(time signal child idle)) {
		1475	undef &{"AnyEvent::Base::$_"}
		1476	if defined &{"$MODEL\::$_"};
		1477	}
		1478
		1479	_isa_set;
		1480
		1481	# we're officially open!
		1482
		1483	if ($ENV{PERL_ANYEVENT_STRICT}) {
		1484	require AnyEvent::Strict;
		1485	}
		1486
		1487	if ($ENV{PERL_ANYEVENT_DEBUG_WRAP}) {
		1488	require AnyEvent::Debug;
		1489	AnyEvent::Debug::wrap ($ENV{PERL_ANYEVENT_DEBUG_WRAP});
		1490	}
		1491
		1492	if (length $ENV{PERL_ANYEVENT_DEBUG_SHELL}) {
		1493	require AnyEvent::Socket;
		1494	require AnyEvent::Debug;
		1495
		1496	my $shell = $ENV{PERL_ANYEVENT_DEBUG_SHELL};
		1497	$shell =~ s/\$\$/$$/g;
		1498
		1499	my ($host, $service) = AnyEvent::Socket::parse_hostport ($shell);
		1500	$AnyEvent::Debug::SHELL = AnyEvent::Debug::shell ($host, $service);
		1501	}
		1502
		1503	# now the anyevent environment is set up as the user told us to, so
		1504	# call the actual user code - post detects
		1505
		1506	(shift @post_detect)->() while @post_detect;
		1507	undef @post_detect;
		1508
		1509	*post_detect = sub(&) {
		1510	shift->();
		1511
		1512	undef
		1513	};
		1514
1260	$MODEL	1515	$MODEL
1261	}	1516	}
1262		1517
1263	sub AUTOLOAD {	1518	for my $name (@methods) {
1264	(my $func = $AUTOLOAD) =~ s/.*://;	1519	*$name = sub {
1265		1520	detect;
1266	$method{$func}	1521	# we use goto because
1267	or Carp::croak "$func: not a valid method for AnyEvent objects";	1522	# a) it makes the thunk more transparent
1268		1523	# b) it allows us to delete the thunk later
1269	detect unless $MODEL;	1524	goto &{ UNIVERSAL::can AnyEvent => "SUPER::$name" }
1270		1525	};
1271	my $class = shift;
1272	$class->$func (@_);
1273	}	1526	}
1274		1527
1275	# utility function to dup a filehandle. this is used by many backends	1528	# utility function to dup a filehandle. this is used by many backends
1276	# to support binding more than one watcher per filehandle (they usually	1529	# to support binding more than one watcher per filehandle (they usually
1277	# allow only one watcher per fd, so we dup it to get a different one).	1530	# allow only one watcher per fd, so we dup it to get a different one).
…		…
1287	# we assume CLOEXEC is already set by perl in all important cases	1540	# we assume CLOEXEC is already set by perl in all important cases
1288		1541
1289	($fh2, $rw)	1542	($fh2, $rw)
1290	}	1543	}
1291		1544
		1545	=head1 SIMPLIFIED AE API
		1546
		1547	Starting with version 5.0, AnyEvent officially supports a second, much
		1548	simpler, API that is designed to reduce the calling, typing and memory
		1549	overhead by using function call syntax and a fixed number of parameters.
		1550
		1551	See the L<AE> manpage for details.
		1552
		1553	=cut
		1554
		1555	package AE;
		1556
		1557	our $VERSION = $AnyEvent::VERSION;
		1558
		1559	sub _reset() {
		1560	eval q{
		1561	# fall back to the main API by default - backends and AnyEvent::Base
		1562	# implementations can overwrite these.
		1563
		1564	sub io($$$) {
		1565	AnyEvent->io (fh => $_[0], poll => $_[1] ? "w" : "r", cb => $_[2])
		1566	}
		1567
		1568	sub timer($$$) {
		1569	AnyEvent->timer (after => $_[0], interval => $_[1], cb => $_[2])
		1570	}
		1571
		1572	sub signal($$) {
		1573	AnyEvent->signal (signal => $_[0], cb => $_[1])
		1574	}
		1575
		1576	sub child($$) {
		1577	AnyEvent->child (pid => $_[0], cb => $_[1])
		1578	}
		1579
		1580	sub idle($) {
		1581	AnyEvent->idle (cb => $_[0]);
		1582	}
		1583
		1584	sub cv(;&) {
		1585	AnyEvent->condvar (@_ ? (cb => $_[0]) : ())
		1586	}
		1587
		1588	sub now() {
		1589	AnyEvent->now
		1590	}
		1591
		1592	sub now_update() {
		1593	AnyEvent->now_update
		1594	}
		1595
		1596	sub time() {
		1597	AnyEvent->time
		1598	}
		1599
		1600	*postpone = \&AnyEvent::postpone;
		1601	*log = \&AnyEvent::log;
		1602	};
		1603	die if $@;
		1604	}
		1605
		1606	BEGIN { _reset }
		1607
1292	package AnyEvent::Base;	1608	package AnyEvent::Base;
1293		1609
1294	# default implementations for many methods	1610	# default implementations for many methods
1295		1611
1296	sub _time {	1612	sub time {
		1613	eval q{ # poor man's autoloading {}
1297	# probe for availability of Time::HiRes	1614	# probe for availability of Time::HiRes
1298	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {	1615	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {
1299	warn "AnyEvent: using Time::HiRes for sub-second timing accuracy.\n" if $VERBOSE >= 8;	1616	*time = sub { Time::HiRes::time () };
1300	*_time = \&Time::HiRes::time;	1617	*AE::time = \& Time::HiRes::time ;
		1618	*now = \&time;
		1619	AnyEvent::log 8 => "AnyEvent: using Time::HiRes for sub-second timing accuracy.";
1301	# if (eval "use POSIX (); (POSIX::times())...	1620	# if (eval "use POSIX (); (POSIX::times())...
1302	} else {	1621	} else {
		1622	*time = sub { CORE::time };
		1623	*AE::time = sub (){ CORE::time };
		1624	*now = \&time;
1303	warn "AnyEvent: using built-in time(), WARNING, no sub-second resolution!\n" if $VERBOSE;	1625	AnyEvent::log 3 => "using built-in time(), WARNING, no sub-second resolution!";
1304	*_time = sub { time }; # epic fail	1626	}
1305	}	1627	};
		1628	die if $@;
1306		1629
1307	&_time	1630	&time
1308	}	1631	}
1309		1632
1310	sub time { _time }	1633	*now = \&time;
1311	sub now { _time }
1312	sub now_update { }	1634	sub now_update { }
1313		1635
		1636	sub _poll {
		1637	Carp::croak "$AnyEvent::MODEL does not support blocking waits. Caught";
		1638	}
		1639
1314	# default implementation for ->condvar	1640	# default implementation for ->condvar
		1641	# in fact, the default should not be overwritten
1315		1642
1316	sub condvar {	1643	sub condvar {
		1644	eval q{ # poor man's autoloading {}
		1645	*condvar = sub {
1317	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"	1646	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"
		1647	};
		1648
		1649	*AE::cv = sub (;&) {
		1650	bless { @_ ? (_ae_cb => shift) : () }, "AnyEvent::CondVar"
		1651	};
		1652	};
		1653	die if $@;
		1654
		1655	&condvar
1318	}	1656	}
1319		1657
1320	# default implementation for ->signal	1658	# default implementation for ->signal
1321		1659
1322	our $HAVE_ASYNC_INTERRUPT;	1660	our $HAVE_ASYNC_INTERRUPT;
1323		1661
1324	sub _have_async_interrupt() {	1662	sub _have_async_interrupt() {
1325	$HAVE_ASYNC_INTERRUPT = 1*(!$ENV{PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT}	1663	$HAVE_ASYNC_INTERRUPT = 1*(!$ENV{PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT}
1326	&& eval "use Async::Interrupt 1.0 (); 1")	1664	&& eval "use Async::Interrupt 1.02 (); 1")
1327	unless defined $HAVE_ASYNC_INTERRUPT;	1665	unless defined $HAVE_ASYNC_INTERRUPT;
1328		1666
1329	$HAVE_ASYNC_INTERRUPT	1667	$HAVE_ASYNC_INTERRUPT
1330	}	1668	}
1331		1669
1332	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);	1670	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);
1333	our (%SIG_ASY, %SIG_ASY_W);	1671	our (%SIG_ASY, %SIG_ASY_W);
1334	our ($SIG_COUNT, $SIG_TW);	1672	our ($SIG_COUNT, $SIG_TW);
1335		1673
1336	sub _signal_exec {
1337	$HAVE_ASYNC_INTERRUPT
1338	? $SIGPIPE_R->drain
1339	: sysread $SIGPIPE_R, my $dummy, 9;
1340
1341	while (%SIG_EV) {
1342	for (keys %SIG_EV) {
1343	delete $SIG_EV{$_};
1344	$_->() for values %{ $SIG_CB{$_} || {} };
1345	}
1346	}
1347	}
1348
1349	# install a dummy wakeup watcher to reduce signal catching latency	1674	# install a dummy wakeup watcher to reduce signal catching latency
		1675	# used by Impls
1350	sub _sig_add() {	1676	sub _sig_add() {
1351	unless ($SIG_COUNT++) {	1677	unless ($SIG_COUNT++) {
1352	# try to align timer on a full-second boundary, if possible	1678	# try to align timer on a full-second boundary, if possible
1353	my $NOW = AnyEvent->now;	1679	my $NOW = AE::now;
1354		1680
1355	$SIG_TW = AnyEvent->timer (	1681	$SIG_TW = AE::timer
1356	after => $MAX_SIGNAL_LATENCY - ($NOW - int $NOW),	1682	$MAX_SIGNAL_LATENCY - ($NOW - int $NOW),
1357	interval => $MAX_SIGNAL_LATENCY,	1683	$MAX_SIGNAL_LATENCY,
1358	cb => sub { }, # just for the PERL_ASYNC_CHECK	1684	sub { } # just for the PERL_ASYNC_CHECK
1359	);	1685	;
1360	}	1686	}
1361	}	1687	}
1362		1688
1363	sub _sig_del {	1689	sub _sig_del {
1364	undef $SIG_TW	1690	undef $SIG_TW
1365	unless --$SIG_COUNT;	1691	unless --$SIG_COUNT;
1366	}	1692	}
1367		1693
1368	our $_sig_name_init; $_sig_name_init = sub {	1694	our $_sig_name_init; $_sig_name_init = sub {
1369	eval q{ # poor man's autoloading	1695	eval q{ # poor man's autoloading {}
1370	undef $_sig_name_init;	1696	undef $_sig_name_init;
1371		1697
1372	if (_have_async_interrupt) {	1698	if (_have_async_interrupt) {
1373	*sig2num = \&Async::Interrupt::sig2num;	1699	*sig2num = \&Async::Interrupt::sig2num;
1374	*sig2name = \&Async::Interrupt::sig2name;	1700	*sig2name = \&Async::Interrupt::sig2name;
…		…
1398		1724
1399	sub signal {	1725	sub signal {
1400	eval q{ # poor man's autoloading {}	1726	eval q{ # poor man's autoloading {}
1401	# probe for availability of Async::Interrupt	1727	# probe for availability of Async::Interrupt
1402	if (_have_async_interrupt) {	1728	if (_have_async_interrupt) {
1403	warn "AnyEvent: using Async::Interrupt for race-free signal handling.\n" if $VERBOSE >= 8;	1729	AnyEvent::log 8 => "using Async::Interrupt for race-free signal handling.";
1404		1730
1405	$SIGPIPE_R = new Async::Interrupt::EventPipe;	1731	$SIGPIPE_R = new Async::Interrupt::EventPipe;
1406	$SIG_IO = AnyEvent->io (fh => $SIGPIPE_R->fileno, poll => "r", cb => \&_signal_exec);	1732	$SIG_IO = AE::io $SIGPIPE_R->fileno, 0, \&_signal_exec;
1407		1733
1408	} else {	1734	} else {
1409	warn "AnyEvent: using emulated perl signal handling with latency timer.\n" if $VERBOSE >= 8;	1735	AnyEvent::log 8 => "using emulated perl signal handling with latency timer.";
1410
1411	require Fcntl;
1412		1736
1413	if (AnyEvent::WIN32) {	1737	if (AnyEvent::WIN32) {
1414	require AnyEvent::Util;	1738	require AnyEvent::Util;
1415		1739
1416	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();	1740	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
1417	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R, 1) if $SIGPIPE_R;	1741	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R, 1) if $SIGPIPE_R;
1418	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W, 1) if $SIGPIPE_W; # just in case	1742	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W, 1) if $SIGPIPE_W; # just in case
1419	} else {	1743	} else {
1420	pipe $SIGPIPE_R, $SIGPIPE_W;	1744	pipe $SIGPIPE_R, $SIGPIPE_W;
1421	fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R;	1745	fcntl $SIGPIPE_R, AnyEvent::F_SETFL, AnyEvent::O_NONBLOCK if $SIGPIPE_R;
1422	fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case	1746	fcntl $SIGPIPE_W, AnyEvent::F_SETFL, AnyEvent::O_NONBLOCK if $SIGPIPE_W; # just in case
1423		1747
1424	# not strictly required, as $^F is normally 2, but let's make sure...	1748	# not strictly required, as $^F is normally 2, but let's make sure...
1425	fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;	1749	fcntl $SIGPIPE_R, AnyEvent::F_SETFD, AnyEvent::FD_CLOEXEC;
1426	fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;	1750	fcntl $SIGPIPE_W, AnyEvent::F_SETFD, AnyEvent::FD_CLOEXEC;
1427	}	1751	}
1428		1752
1429	$SIGPIPE_R	1753	$SIGPIPE_R
1430	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";	1754	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";
1431		1755
1432	$SIG_IO = AnyEvent->io (fh => $SIGPIPE_R, poll => "r", cb => \&_signal_exec);	1756	$SIG_IO = AE::io $SIGPIPE_R, 0, \&_signal_exec;
1433	}	1757	}
1434		1758
1435	*signal = sub {	1759	*signal = $HAVE_ASYNC_INTERRUPT
		1760	? sub {
1436	my (undef, %arg) = @_;	1761	my (undef, %arg) = @_;
1437		1762
1438	my $signal = uc $arg{signal}
1439	or Carp::croak "required option 'signal' is missing";
1440
1441	if ($HAVE_ASYNC_INTERRUPT) {
1442	# async::interrupt	1763	# async::interrupt
1443
1444	$signal = sig2num $signal;	1764	my $signal = sig2num $arg{signal};
1445	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};	1765	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
1446		1766
1447	$SIG_ASY{$signal} ||= new Async::Interrupt	1767	$SIG_ASY{$signal} ||= new Async::Interrupt
1448	cb => sub { undef $SIG_EV{$signal} },	1768	cb => sub { undef $SIG_EV{$signal} },
1449	signal => $signal,	1769	signal => $signal,
1450	pipe => [$SIGPIPE_R->filenos],	1770	pipe => [$SIGPIPE_R->filenos],
1451	pipe_autodrain => 0,	1771	pipe_autodrain => 0,
1452	;	1772	;
1453		1773
1454	} else {	1774	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
		1775	}
		1776	: sub {
		1777	my (undef, %arg) = @_;
		1778
1455	# pure perl	1779	# pure perl
1456
1457	# AE::Util has been loaded in signal
1458	$signal = sig2name $signal;	1780	my $signal = sig2name $arg{signal};
1459	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};	1781	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
1460		1782
1461	$SIG{$signal} ||= sub {	1783	$SIG{$signal} ||= sub {
1462	local $!;	1784	local $!;
1463	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;	1785	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;
1464	undef $SIG_EV{$signal};	1786	undef $SIG_EV{$signal};
1465	};	1787	};
1466		1788
1467	# can't do signal processing without introducing races in pure perl,	1789	# can't do signal processing without introducing races in pure perl,
1468	# so limit the signal latency.	1790	# so limit the signal latency.
1469	_sig_add;	1791	_sig_add;
1470	}
1471		1792
1472	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"	1793	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
		1794	}
1473	};	1795	;
1474		1796
1475	*AnyEvent::Base::signal::DESTROY = sub {	1797	*AnyEvent::Base::signal::DESTROY = sub {
1476	my ($signal, $cb) = @{$_[0]};	1798	my ($signal, $cb) = @{$_[0]};
1477		1799
1478	_sig_del;	1800	_sig_del;
…		…
1485	# print weird messages, or just unconditionally exit	1807	# print weird messages, or just unconditionally exit
1486	# instead of getting the default action.	1808	# instead of getting the default action.
1487	undef $SIG{$signal}	1809	undef $SIG{$signal}
1488	unless keys %{ $SIG_CB{$signal} };	1810	unless keys %{ $SIG_CB{$signal} };
1489	};	1811	};
		1812
		1813	*_signal_exec = sub {
		1814	$HAVE_ASYNC_INTERRUPT
		1815	? $SIGPIPE_R->drain
		1816	: sysread $SIGPIPE_R, (my $dummy), 9;
		1817
		1818	while (%SIG_EV) {
		1819	for (keys %SIG_EV) {
		1820	delete $SIG_EV{$_};
		1821	&$_ for values %{ $SIG_CB{$_} || {} };
		1822	}
		1823	}
		1824	};
1490	};	1825	};
1491	die if $@;	1826	die if $@;
		1827
1492	&signal	1828	&signal
1493	}	1829	}
1494		1830
1495	# default implementation for ->child	1831	# default implementation for ->child
1496		1832
1497	our %PID_CB;	1833	our %PID_CB;
1498	our $CHLD_W;	1834	our $CHLD_W;
1499	our $CHLD_DELAY_W;	1835	our $CHLD_DELAY_W;
1500	our $WNOHANG;
1501		1836
		1837	# used by many Impl's
1502	sub _emit_childstatus($$) {	1838	sub _emit_childstatus($$) {
1503	my (undef, $rpid, $rstatus) = @_;	1839	my (undef, $rpid, $rstatus) = @_;
1504		1840
1505	$_->($rpid, $rstatus)	1841	$_->($rpid, $rstatus)
1506	for values %{ $PID_CB{$rpid} || {} },	1842	for values %{ $PID_CB{$rpid} || {} },
1507	values %{ $PID_CB{0} || {} };	1843	values %{ $PID_CB{0} || {} };
1508	}	1844	}
1509		1845
1510	sub _sigchld {
1511	my $pid;
1512
1513	AnyEvent->_emit_childstatus ($pid, $?)
1514	while ($pid = waitpid -1, $WNOHANG) > 0;
1515	}
1516
1517	sub child {	1846	sub child {
		1847	eval q{ # poor man's autoloading {}
		1848	*_sigchld = sub {
		1849	my $pid;
		1850
		1851	AnyEvent->_emit_childstatus ($pid, $?)
		1852	while ($pid = waitpid -1, WNOHANG) > 0;
		1853	};
		1854
		1855	*child = sub {
1518	my (undef, %arg) = @_;	1856	my (undef, %arg) = @_;
1519		1857
1520	defined (my $pid = $arg{pid} + 0)	1858	my $pid = $arg{pid};
1521	or Carp::croak "required option 'pid' is missing";	1859	my $cb = $arg{cb};
1522		1860
1523	$PID_CB{$pid}{$arg{cb}} = $arg{cb};	1861	$PID_CB{$pid}{$cb+0} = $cb;
1524		1862
1525	# WNOHANG is almost cetrainly 1 everywhere
1526	$WNOHANG ||= $^O =~ /^(?:openbsd|netbsd|linux|freebsd|cygwin|MSWin32)$/
1527	? 1
1528	: eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1;
1529
1530	unless ($CHLD_W) {	1863	unless ($CHLD_W) {
1531	$CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld);	1864	$CHLD_W = AE::signal CHLD => \&_sigchld;
1532	# child could be a zombie already, so make at least one round	1865	# child could be a zombie already, so make at least one round
1533	&_sigchld;	1866	&_sigchld;
1534	}	1867	}
1535		1868
1536	bless [$pid, $arg{cb}], "AnyEvent::Base::child"	1869	bless [$pid, $cb+0], "AnyEvent::Base::child"
1537	}	1870	};
1538		1871
1539	sub AnyEvent::Base::child::DESTROY {	1872	*AnyEvent::Base::child::DESTROY = sub {
1540	my ($pid, $cb) = @{$_[0]};	1873	my ($pid, $icb) = @{$_[0]};
1541		1874
1542	delete $PID_CB{$pid}{$cb};	1875	delete $PID_CB{$pid}{$icb};
1543	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };	1876	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };
1544		1877
1545	undef $CHLD_W unless keys %PID_CB;	1878	undef $CHLD_W unless keys %PID_CB;
		1879	};
		1880	};
		1881	die if $@;
		1882
		1883	&child
1546	}	1884	}
1547		1885
1548	# idle emulation is done by simply using a timer, regardless	1886	# idle emulation is done by simply using a timer, regardless
1549	# of whether the process is idle or not, and not letting	1887	# of whether the process is idle or not, and not letting
1550	# the callback use more than 50% of the time.	1888	# the callback use more than 50% of the time.
1551	sub idle {	1889	sub idle {
		1890	eval q{ # poor man's autoloading {}
		1891	*idle = sub {
1552	my (undef, %arg) = @_;	1892	my (undef, %arg) = @_;
1553		1893
1554	my ($cb, $w, $rcb) = $arg{cb};	1894	my ($cb, $w, $rcb) = $arg{cb};
1555		1895
1556	$rcb = sub {	1896	$rcb = sub {
1557	if ($cb) {	1897	if ($cb) {
1558	$w = _time;	1898	$w = AE::time;
1559	&$cb;	1899	&$cb;
1560	$w = _time - $w;	1900	$w = AE::time - $w;
1561		1901
1562	# never use more then 50% of the time for the idle watcher,	1902	# never use more then 50% of the time for the idle watcher,
1563	# within some limits	1903	# within some limits
1564	$w = 0.0001 if $w < 0.0001;	1904	$w = 0.0001 if $w < 0.0001;
1565	$w = 5 if $w > 5;	1905	$w = 5 if $w > 5;
1566		1906
1567	$w = AnyEvent->timer (after => $w, cb => $rcb);	1907	$w = AE::timer $w, 0, $rcb;
1568	} else {	1908	} else {
1569	# clean up...	1909	# clean up...
1570	undef $w;	1910	undef $w;
1571	undef $rcb;	1911	undef $rcb;
		1912	}
		1913	};
		1914
		1915	$w = AE::timer 0.05, 0, $rcb;
		1916
		1917	bless \\$cb, "AnyEvent::Base::idle"
1572	}	1918	};
		1919
		1920	*AnyEvent::Base::idle::DESTROY = sub {
		1921	undef $${$_[0]};
		1922	};
1573	};	1923	};
		1924	die if $@;
1574		1925
1575	$w = AnyEvent->timer (after => 0.05, cb => $rcb);	1926	&idle
1576
1577	bless \\$cb, "AnyEvent::Base::idle"
1578	}
1579
1580	sub AnyEvent::Base::idle::DESTROY {
1581	undef $${$_[0]};
1582	}	1927	}
1583		1928
1584	package AnyEvent::CondVar;	1929	package AnyEvent::CondVar;
1585		1930
1586	our @ISA = AnyEvent::CondVar::Base::;	1931	our @ISA = AnyEvent::CondVar::Base::;
		1932
		1933	# only to be used for subclassing
		1934	sub new {
		1935	my $class = shift;
		1936	bless AnyEvent->condvar (@_), $class
		1937	}
1587		1938
1588	package AnyEvent::CondVar::Base;	1939	package AnyEvent::CondVar::Base;
1589		1940
1590	#use overload	1941	#use overload
1591	# '&{}' => sub { my $self = shift; sub { $self->send (@_) } },	1942	# '&{}' => sub { my $self = shift; sub { $self->send (@_) } },
…		…
1601		1952
1602	sub _send {	1953	sub _send {
1603	# nop	1954	# nop
1604	}	1955	}
1605		1956
		1957	sub _wait {
		1958	AnyEvent->_poll until $_[0]{_ae_sent};
		1959	}
		1960
1606	sub send {	1961	sub send {
1607	my $cv = shift;	1962	my $cv = shift;
1608	$cv->{_ae_sent} = [@_];	1963	$cv->{_ae_sent} = [@_];
1609	(delete $cv->{_ae_cb})->($cv) if $cv->{_ae_cb};	1964	(delete $cv->{_ae_cb})->($cv) if $cv->{_ae_cb};
1610	$cv->_send;	1965	$cv->_send;
…		…
1617		1972
1618	sub ready {	1973	sub ready {
1619	$_[0]{_ae_sent}	1974	$_[0]{_ae_sent}
1620	}	1975	}
1621		1976
1622	sub _wait {
1623	$WAITING
1624	and !$_[0]{_ae_sent}
1625	and Carp::croak "AnyEvent::CondVar: recursive blocking wait detected";
1626
1627	local $WAITING = 1;
1628	AnyEvent->one_event while !$_[0]{_ae_sent};
1629	}
1630
1631	sub recv {	1977	sub recv {
		1978	unless ($_[0]{_ae_sent}) {
		1979	$WAITING
		1980	and Carp::croak "AnyEvent::CondVar: recursive blocking wait attempted";
		1981
		1982	local $WAITING = 1;
1632	$_[0]->_wait;	1983	$_[0]->_wait;
		1984	}
1633		1985
1634	Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak};	1986	$_[0]{_ae_croak}
1635	wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0]	1987	and Carp::croak $_[0]{_ae_croak};
		1988
		1989	wantarray
		1990	? @{ $_[0]{_ae_sent} }
		1991	: $_[0]{_ae_sent}[0]
1636	}	1992	}
1637		1993
1638	sub cb {	1994	sub cb {
1639	my $cv = shift;	1995	my $cv = shift;
1640		1996
…		…
1656	&{ $_[0]{_ae_end_cb} || sub { $_[0]->send } };	2012	&{ $_[0]{_ae_end_cb} || sub { $_[0]->send } };
1657	}	2013	}
1658		2014
1659	# undocumented/compatibility with pre-3.4	2015	# undocumented/compatibility with pre-3.4
1660	*broadcast = \&send;	2016	*broadcast = \&send;
1661	*wait = \&_wait;	2017	*wait = \&recv;
1662
1663	#############################################################################
1664	# "new" API, currently only emulation of it
1665	#############################################################################
1666
1667	package AE;
1668
1669	sub io($$$) {
1670	AnyEvent->io (fh => $_[0], poll => $_[1] ? "w" : "r", cb => $_[2])
1671	}
1672
1673	sub timer($$$) {
1674	AnyEvent->timer (after => $_[0], interval => $_[1], cb => $_[2]);
1675	}
1676
1677	sub signal($$) {
1678	AnyEvent->signal (signal => $_[0], cb => $_[1]);
1679	}
1680
1681	sub child($$) {
1682	AnyEvent->child (pid => $_[0], cb => $_[1]);
1683	}
1684
1685	sub idle($) {
1686	AnyEvent->idle (cb => $_[0]);
1687	}
1688
1689	sub cv() {
1690	AnyEvent->condvar
1691	}
1692
1693	sub now() {
1694	AnyEvent->now
1695	}
1696
1697	sub now_update() {
1698	AnyEvent->now_update
1699	}
1700
1701	sub time() {
1702	AnyEvent->time
1703	}
1704		2018
1705	=head1 ERROR AND EXCEPTION HANDLING	2019	=head1 ERROR AND EXCEPTION HANDLING
1706		2020
1707	In general, AnyEvent does not do any error handling - it relies on the	2021	In general, AnyEvent does not do any error handling - it relies on the
1708	caller to do that if required. The L<AnyEvent::Strict> module (see also	2022	caller to do that if required. The L<AnyEvent::Strict> module (see also
…		…
1720	$Event/EV::DIED->() >>, L<Glib> uses C<< install_exception_handler >> and	2034	$Event/EV::DIED->() >>, L<Glib> uses C<< install_exception_handler >> and
1721	so on.	2035	so on.
1722		2036
1723	=head1 ENVIRONMENT VARIABLES	2037	=head1 ENVIRONMENT VARIABLES
1724		2038
1725	The following environment variables are used by this module or its	2039	AnyEvent supports a number of environment variables that tune the
1726	submodules.	2040	runtime behaviour. They are usually evaluated when AnyEvent is
		2041	loaded, initialised, or a submodule that uses them is loaded. Many of
		2042	them also cause AnyEvent to load additional modules - for example,
		2043	C<PERL_ANYEVENT_DEBUG_WRAP> causes the L<AnyEvent::Debug> module to be
		2044	loaded.
1727		2045
1728	Note that AnyEvent will remove I<all> environment variables starting with	2046	All the environment variables documented here start with
1729	C<PERL_ANYEVENT_> from C<%ENV> when it is loaded while taint mode is	2047	C<PERL_ANYEVENT_>, which is what AnyEvent considers its own
1730	enabled.	2048	namespace. Other modules are encouraged (but by no means required) to use
		2049	C<PERL_ANYEVENT_SUBMODULE> if they have registered the AnyEvent::Submodule
		2050	namespace on CPAN, for any submodule. For example, L<AnyEvent::HTTP> could
		2051	be expected to use C<PERL_ANYEVENT_HTTP_PROXY> (it should not access env
		2052	variables starting with C<AE_>, see below).
		2053
		2054	All variables can also be set via the C<AE_> prefix, that is, instead
		2055	of setting C<PERL_ANYEVENT_VERBOSE> you can also set C<AE_VERBOSE>. In
		2056	case there is a clash btween anyevent and another program that uses
		2057	C<AE_something> you can set the corresponding C<PERL_ANYEVENT_something>
		2058	variable to the empty string, as those variables take precedence.
		2059
		2060	When AnyEvent is first loaded, it copies all C<AE_xxx> env variables
		2061	to their C<PERL_ANYEVENT_xxx> counterpart unless that variable already
		2062	exists. If taint mode is on, then AnyEvent will remove I<all> environment
		2063	variables starting with C<PERL_ANYEVENT_> from C<%ENV> (or replace them
		2064	with C<undef> or the empty string, if the corresaponding C<AE_> variable
		2065	is set).
		2066
		2067	The exact algorithm is currently:
		2068
		2069	1. if taint mode enabled, delete all PERL_ANYEVENT_xyz variables from %ENV
		2070	2. copy over AE_xyz to PERL_ANYEVENT_xyz unless the latter alraedy exists
		2071	3. if taint mode enabled, set all PERL_ANYEVENT_xyz variables to undef.
		2072
		2073	This ensures that child processes will not see the C<AE_> variables.
		2074
		2075	The following environment variables are currently known to AnyEvent:
1731		2076
1732	=over 4	2077	=over 4
1733		2078
1734	=item C<PERL_ANYEVENT_VERBOSE>	2079	=item C<PERL_ANYEVENT_VERBOSE>
1735		2080
1736	By default, AnyEvent will be completely silent except in fatal	2081	By default, AnyEvent will only log messages with loglevel C<3>
1737	conditions. You can set this environment variable to make AnyEvent more	2082	(C<critical>) or higher (see L<AnyEvent::Log>). You can set this
		2083	environment variable to a numerical loglevel to make AnyEvent more (or
1738	talkative.	2084	less) talkative.
1739		2085
		2086	If you want to do more than just set the global logging level
		2087	you should have a look at C<PERL_ANYEVENT_LOG>, which allows much more
		2088	complex specifications.
		2089
		2090	When set to C<0> (C<off>), then no messages whatsoever will be logged with
		2091	the default logging settings.
		2092
1740	When set to C<1> or higher, causes AnyEvent to warn about unexpected	2093	When set to C<5> or higher (C<warn>), causes AnyEvent to warn about
1741	conditions, such as not being able to load the event model specified by	2094	unexpected conditions, such as not being able to load the event model
1742	C<PERL_ANYEVENT_MODEL>.	2095	specified by C<PERL_ANYEVENT_MODEL>, or a guard callback throwing an
		2096	exception - this is the minimum recommended level.
1743		2097
1744	When set to C<2> or higher, cause AnyEvent to report to STDERR which event	2098	When set to C<7> or higher (info), cause AnyEvent to report which event model it
1745	model it chooses.	2099	chooses.
1746		2100
1747	When set to C<8> or higher, then AnyEvent will report extra information on	2101	When set to C<8> or higher (debug), then AnyEvent will report extra information on
1748	which optional modules it loads and how it implements certain features.	2102	which optional modules it loads and how it implements certain features.
		2103
		2104	=item C<PERL_ANYEVENT_LOG>
		2105
		2106	Accepts rather complex logging specifications. For example, you could log
		2107	all C<debug> messages of some module to stderr, warnings and above to
		2108	stderr, and errors and above to syslog, with:
		2109
		2110	PERL_ANYEVENT_LOG=Some::Module=debug,+log:filter=warn,+%syslog:%syslog=error,syslog
		2111
		2112	For the rather extensive details, see L<AnyEvent::Log>.
		2113
		2114	This variable is evaluated when AnyEvent (or L<AnyEvent::Log>) is loaded,
		2115	so will take effect even before AnyEvent has initialised itself.
		2116
		2117	Note that specifying this environment variable causes the L<AnyEvent::Log>
		2118	module to be loaded, while C<PERL_ANYEVENT_VERBOSE> does not, so only
		2119	using the latter saves a few hundred kB of memory until the first message
		2120	is being logged.
1749		2121
1750	=item C<PERL_ANYEVENT_STRICT>	2122	=item C<PERL_ANYEVENT_STRICT>
1751		2123
1752	AnyEvent does not do much argument checking by default, as thorough	2124	AnyEvent does not do much argument checking by default, as thorough
1753	argument checking is very costly. Setting this variable to a true value	2125	argument checking is very costly. Setting this variable to a true value
…		…
1755	check the arguments passed to most method calls. If it finds any problems,	2127	check the arguments passed to most method calls. If it finds any problems,
1756	it will croak.	2128	it will croak.
1757		2129
1758	In other words, enables "strict" mode.	2130	In other words, enables "strict" mode.
1759		2131
1760	Unlike C<use strict> (or it's modern cousin, C<< use L<common::sense>	2132	Unlike C<use strict> (or its modern cousin, C<< use L<common::sense>
1761	>>, it is definitely recommended to keep it off in production. Keeping	2133	>>, it is definitely recommended to keep it off in production. Keeping
1762	C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs	2134	C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs
1763	can be very useful, however.	2135	can be very useful, however.
1764		2136
		2137	=item C<PERL_ANYEVENT_DEBUG_SHELL>
		2138
		2139	If this env variable is nonempty, then its contents will be interpreted by
		2140	C<AnyEvent::Socket::parse_hostport> and C<AnyEvent::Debug::shell> (after
		2141	replacing every occurance of C<$$> by the process pid). The shell object
		2142	is saved in C<$AnyEvent::Debug::SHELL>.
		2143
		2144	This happens when the first watcher is created.
		2145
		2146	For example, to bind a debug shell on a unix domain socket in
		2147	F<< /tmp/debug<pid>.sock >>, you could use this:
		2148
		2149	PERL_ANYEVENT_DEBUG_SHELL=/tmp/debug\$\$.sock perlprog
		2150	# connect with e.g.: socat readline /tmp/debug123.sock
		2151
		2152	Or to bind to tcp port 4545 on localhost:
		2153
		2154	PERL_ANYEVENT_DEBUG_SHELL=127.0.0.1:4545 perlprog
		2155	# connect with e.g.: telnet localhost 4545
		2156
		2157	Note that creating sockets in F</tmp> or on localhost is very unsafe on
		2158	multiuser systems.
		2159
		2160	=item C<PERL_ANYEVENT_DEBUG_WRAP>
		2161
		2162	Can be set to C<0>, C<1> or C<2> and enables wrapping of all watchers for
		2163	debugging purposes. See C<AnyEvent::Debug::wrap> for details.
		2164
1765	=item C<PERL_ANYEVENT_MODEL>	2165	=item C<PERL_ANYEVENT_MODEL>
1766		2166
1767	This can be used to specify the event model to be used by AnyEvent, before	2167	This can be used to specify the event model to be used by AnyEvent, before
1768	auto detection and -probing kicks in. It must be a string consisting	2168	auto detection and -probing kicks in.
1769	entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended	2169
		2170	It normally is a string consisting entirely of ASCII letters (e.g. C<EV>
		2171	or C<IOAsync>). The string C<AnyEvent::Impl::> gets prepended and the
1770	and the resulting module name is loaded and if the load was successful,	2172	resulting module name is loaded and - if the load was successful - used as
1771	used as event model. If it fails to load AnyEvent will proceed with	2173	event model backend. If it fails to load then AnyEvent will proceed with
1772	auto detection and -probing.	2174	auto detection and -probing.
1773		2175
1774	This functionality might change in future versions.	2176	If the string ends with C<::> instead (e.g. C<AnyEvent::Impl::EV::>) then
		2177	nothing gets prepended and the module name is used as-is (hint: C<::> at
		2178	the end of a string designates a module name and quotes it appropriately).
1775		2179
1776	For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you	2180	For example, to force the pure perl model (L<AnyEvent::Loop::Perl>) you
1777	could start your program like this:	2181	could start your program like this:
1778		2182
1779	PERL_ANYEVENT_MODEL=Perl perl ...	2183	PERL_ANYEVENT_MODEL=Perl perl ...
1780		2184
1781	=item C<PERL_ANYEVENT_PROTOCOLS>	2185	=item C<PERL_ANYEVENT_PROTOCOLS>
…		…
1797	but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4>	2201	but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4>
1798	- only support IPv4, never try to resolve or contact IPv6	2202	- only support IPv4, never try to resolve or contact IPv6
1799	addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or	2203	addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or
1800	IPv6, but prefer IPv6 over IPv4.	2204	IPv6, but prefer IPv6 over IPv4.
1801		2205
		2206	=item C<PERL_ANYEVENT_HOSTS>
		2207
		2208	This variable, if specified, overrides the F</etc/hosts> file used by
		2209	L<AnyEvent::Socket>C<::resolve_sockaddr>, i.e. hosts aliases will be read
		2210	from that file instead.
		2211
1802	=item C<PERL_ANYEVENT_EDNS0>	2212	=item C<PERL_ANYEVENT_EDNS0>
1803		2213
1804	Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension	2214	Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension for
1805	for DNS. This extension is generally useful to reduce DNS traffic, but	2215	DNS. This extension is generally useful to reduce DNS traffic, especially
1806	some (broken) firewalls drop such DNS packets, which is why it is off by	2216	when DNSSEC is involved, but some (broken) firewalls drop such DNS
1807	default.	2217	packets, which is why it is off by default.
1808		2218
1809	Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce	2219	Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce
1810	EDNS0 in its DNS requests.	2220	EDNS0 in its DNS requests.
1811		2221
1812	=item C<PERL_ANYEVENT_MAX_FORKS>	2222	=item C<PERL_ANYEVENT_MAX_FORKS>
…		…
1818		2228
1819	The default value for the C<max_outstanding> parameter for the default DNS	2229	The default value for the C<max_outstanding> parameter for the default DNS
1820	resolver - this is the maximum number of parallel DNS requests that are	2230	resolver - this is the maximum number of parallel DNS requests that are
1821	sent to the DNS server.	2231	sent to the DNS server.
1822		2232
		2233	=item C<PERL_ANYEVENT_MAX_SIGNAL_LATENCY>
		2234
		2235	Perl has inherently racy signal handling (you can basically choose between
		2236	losing signals and memory corruption) - pure perl event loops (including
		2237	C<AnyEvent::Loop>, when C<Async::Interrupt> isn't available) therefore
		2238	have to poll regularly to avoid losing signals.
		2239
		2240	Some event loops are racy, but don't poll regularly, and some event loops
		2241	are written in C but are still racy. For those event loops, AnyEvent
		2242	installs a timer that regularly wakes up the event loop.
		2243
		2244	By default, the interval for this timer is C<10> seconds, but you can
		2245	override this delay with this environment variable (or by setting
		2246	the C<$AnyEvent::MAX_SIGNAL_LATENCY> variable before creating signal
		2247	watchers).
		2248
		2249	Lower values increase CPU (and energy) usage, higher values can introduce
		2250	long delays when reaping children or waiting for signals.
		2251
		2252	The L<AnyEvent::Async> module, if available, will be used to avoid this
		2253	polling (with most event loops).
		2254
1823	=item C<PERL_ANYEVENT_RESOLV_CONF>	2255	=item C<PERL_ANYEVENT_RESOLV_CONF>
1824		2256
1825	The file to use instead of F</etc/resolv.conf> (or OS-specific	2257	The absolute path to a F<resolv.conf>-style file to use instead of
1826	configuration) in the default resolver. When set to the empty string, no	2258	F</etc/resolv.conf> (or the OS-specific configuration) in the default
1827	default config will be used.	2259	resolver, or the empty string to select the default configuration.
1828		2260
1829	=item C<PERL_ANYEVENT_CA_FILE>, C<PERL_ANYEVENT_CA_PATH>.	2261	=item C<PERL_ANYEVENT_CA_FILE>, C<PERL_ANYEVENT_CA_PATH>.
1830		2262
1831	When neither C<ca_file> nor C<ca_path> was specified during	2263	When neither C<ca_file> nor C<ca_path> was specified during
1832	L<AnyEvent::TLS> context creation, and either of these environment	2264	L<AnyEvent::TLS> context creation, and either of these environment
1833	variables exist, they will be used to specify CA certificate locations	2265	variables are nonempty, they will be used to specify CA certificate
1834	instead of a system-dependent default.	2266	locations instead of a system-dependent default.
1835		2267
1836	=item C<PERL_ANYEVENT_AVOID_GUARD> and C<PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT>	2268	=item C<PERL_ANYEVENT_AVOID_GUARD> and C<PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT>
1837		2269
1838	When these are set to C<1>, then the respective modules are not	2270	When these are set to C<1>, then the respective modules are not
1839	loaded. Mostly good for testing AnyEvent itself.	2271	loaded. Mostly good for testing AnyEvent itself.
…		…
1902	warn "read: $input\n"; # output what has been read	2334	warn "read: $input\n"; # output what has been read
1903	$cv->send if $input =~ /^q/i; # quit program if /^q/i	2335	$cv->send if $input =~ /^q/i; # quit program if /^q/i
1904	},	2336	},
1905	);	2337	);
1906		2338
1907	my $time_watcher; # can only be used once
1908
1909	sub new_timer {
1910	$timer = AnyEvent->timer (after => 1, cb => sub {	2339	my $time_watcher = AnyEvent->timer (after => 1, interval => 1, cb => sub {
1911	warn "timeout\n"; # print 'timeout' about every second	2340	warn "timeout\n"; # print 'timeout' at most every second
1912	&new_timer; # and restart the time
1913	});	2341	});
1914	}
1915
1916	new_timer; # create first timer
1917		2342
1918	$cv->recv; # wait until user enters /^q/i	2343	$cv->recv; # wait until user enters /^q/i
1919		2344
1920	=head1 REAL-WORLD EXAMPLE	2345	=head1 REAL-WORLD EXAMPLE
1921		2346
…		…
1994		2419
1995	The actual code goes further and collects all errors (C<die>s, exceptions)	2420	The actual code goes further and collects all errors (C<die>s, exceptions)
1996	that occurred during request processing. The C<result> method detects	2421	that occurred during request processing. The C<result> method detects
1997	whether an exception as thrown (it is stored inside the $txn object)	2422	whether an exception as thrown (it is stored inside the $txn object)
1998	and just throws the exception, which means connection errors and other	2423	and just throws the exception, which means connection errors and other
1999	problems get reported tot he code that tries to use the result, not in a	2424	problems get reported to the code that tries to use the result, not in a
2000	random callback.	2425	random callback.
2001		2426
2002	All of this enables the following usage styles:	2427	All of this enables the following usage styles:
2003		2428
2004	1. Blocking:	2429	1. Blocking:
…		…
2052	through AnyEvent. The benchmark creates a lot of timers (with a zero	2477	through AnyEvent. The benchmark creates a lot of timers (with a zero
2053	timeout) and I/O watchers (watching STDOUT, a pty, to become writable,	2478	timeout) and I/O watchers (watching STDOUT, a pty, to become writable,
2054	which it is), lets them fire exactly once and destroys them again.	2479	which it is), lets them fire exactly once and destroys them again.
2055		2480
2056	Source code for this benchmark is found as F<eg/bench> in the AnyEvent	2481	Source code for this benchmark is found as F<eg/bench> in the AnyEvent
2057	distribution.	2482	distribution. It uses the L<AE> interface, which makes a real difference
		2483	for the EV and Perl backends only.
2058		2484
2059	=head3 Explanation of the columns	2485	=head3 Explanation of the columns
2060		2486
2061	I<watcher> is the number of event watchers created/destroyed. Since	2487	I<watcher> is the number of event watchers created/destroyed. Since
2062	different event models feature vastly different performances, each event	2488	different event models feature vastly different performances, each event
…		…
2083	watcher.	2509	watcher.
2084		2510
2085	=head3 Results	2511	=head3 Results
2086		2512
2087	name watchers bytes create invoke destroy comment	2513	name watchers bytes create invoke destroy comment
2088	EV/EV 400000 224 0.47 0.35 0.27 EV native interface	2514	EV/EV 100000 223 0.47 0.43 0.27 EV native interface
2089	EV/Any 100000 224 2.88 0.34 0.27 EV + AnyEvent watchers	2515	EV/Any 100000 223 0.48 0.42 0.26 EV + AnyEvent watchers
2090	CoroEV/Any 100000 224 2.85 0.35 0.28 coroutines + Coro::Signal	2516	Coro::EV/Any 100000 223 0.47 0.42 0.26 coroutines + Coro::Signal
2091	Perl/Any 100000 452 4.13 0.73 0.95 pure perl implementation	2517	Perl/Any 100000 431 2.70 0.74 0.92 pure perl implementation
2092	Event/Event 16000 517 32.20 31.80 0.81 Event native interface	2518	Event/Event 16000 516 31.16 31.84 0.82 Event native interface
2093	Event/Any 16000 590 35.85 31.55 1.06 Event + AnyEvent watchers	2519	Event/Any 16000 1203 42.61 34.79 1.80 Event + AnyEvent watchers
2094	IOAsync/Any 16000 989 38.10 32.77 11.13 via IO::Async::Loop::IO_Poll	2520	IOAsync/Any 16000 1911 41.92 27.45 16.81 via IO::Async::Loop::IO_Poll
2095	IOAsync/Any 16000 990 37.59 29.50 10.61 via IO::Async::Loop::Epoll	2521	IOAsync/Any 16000 1726 40.69 26.37 15.25 via IO::Async::Loop::Epoll
2096	Glib/Any 16000 1357 102.33 12.31 51.00 quadratic behaviour	2522	Glib/Any 16000 1118 89.00 12.57 51.17 quadratic behaviour
2097	Tk/Any 2000 1860 27.20 66.31 14.00 SEGV with >> 2000 watchers	2523	Tk/Any 2000 1346 20.96 10.75 8.00 SEGV with >> 2000 watchers
2098	POE/Event 2000 6328 109.99 751.67 14.02 via POE::Loop::Event	2524	POE/Any 2000 6951 108.97 795.32 14.24 via POE::Loop::Event
2099	POE/Select 2000 6027 94.54 809.13 579.80 via POE::Loop::Select	2525	POE/Any 2000 6648 94.79 774.40 575.51 via POE::Loop::Select
2100		2526
2101	=head3 Discussion	2527	=head3 Discussion
2102		2528
2103	The benchmark does I<not> measure scalability of the event loop very	2529	The benchmark does I<not> measure scalability of the event loop very
2104	well. For example, a select-based event loop (such as the pure perl one)	2530	well. For example, a select-based event loop (such as the pure perl one)
…		…
2116	benchmark machine, handling an event takes roughly 1600 CPU cycles with	2542	benchmark machine, handling an event takes roughly 1600 CPU cycles with
2117	EV, 3100 CPU cycles with AnyEvent's pure perl loop and almost 3000000 CPU	2543	EV, 3100 CPU cycles with AnyEvent's pure perl loop and almost 3000000 CPU
2118	cycles with POE.	2544	cycles with POE.
2119		2545
2120	C<EV> is the sole leader regarding speed and memory use, which are both	2546	C<EV> is the sole leader regarding speed and memory use, which are both
2121	maximal/minimal, respectively. Even when going through AnyEvent, it uses	2547	maximal/minimal, respectively. When using the L<AE> API there is zero
		2548	overhead (when going through the AnyEvent API create is about 5-6 times
		2549	slower, with other times being equal, so still uses far less memory than
2122	far less memory than any other event loop and is still faster than Event	2550	any other event loop and is still faster than Event natively).
2123	natively.
2124		2551
2125	The pure perl implementation is hit in a few sweet spots (both the	2552	The pure perl implementation is hit in a few sweet spots (both the
2126	constant timeout and the use of a single fd hit optimisations in the perl	2553	constant timeout and the use of a single fd hit optimisations in the perl
2127	interpreter and the backend itself). Nevertheless this shows that it	2554	interpreter and the backend itself). Nevertheless this shows that it
2128	adds very little overhead in itself. Like any select-based backend its	2555	adds very little overhead in itself. Like any select-based backend its
…		…
2176	(even when used without AnyEvent), but most event loops have acceptable	2603	(even when used without AnyEvent), but most event loops have acceptable
2177	performance with or without AnyEvent.	2604	performance with or without AnyEvent.
2178		2605
2179	=item * The overhead AnyEvent adds is usually much smaller than the overhead of	2606	=item * The overhead AnyEvent adds is usually much smaller than the overhead of
2180	the actual event loop, only with extremely fast event loops such as EV	2607	the actual event loop, only with extremely fast event loops such as EV
2181	adds AnyEvent significant overhead.	2608	does AnyEvent add significant overhead.
2182		2609
2183	=item * You should avoid POE like the plague if you want performance or	2610	=item * You should avoid POE like the plague if you want performance or
2184	reasonable memory usage.	2611	reasonable memory usage.
2185		2612
2186	=back	2613	=back
…		…
2202	In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100	2629	In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100
2203	(1%) are active. This mirrors the activity of large servers with many	2630	(1%) are active. This mirrors the activity of large servers with many
2204	connections, most of which are idle at any one point in time.	2631	connections, most of which are idle at any one point in time.
2205		2632
2206	Source code for this benchmark is found as F<eg/bench2> in the AnyEvent	2633	Source code for this benchmark is found as F<eg/bench2> in the AnyEvent
2207	distribution.	2634	distribution. It uses the L<AE> interface, which makes a real difference
		2635	for the EV and Perl backends only.
2208		2636
2209	=head3 Explanation of the columns	2637	=head3 Explanation of the columns
2210		2638
2211	I<sockets> is the number of sockets, and twice the number of "servers" (as	2639	I<sockets> is the number of sockets, and twice the number of "servers" (as
2212	each server has a read and write socket end).	2640	each server has a read and write socket end).
…		…
2220	a new one that moves the timeout into the future.	2648	a new one that moves the timeout into the future.
2221		2649
2222	=head3 Results	2650	=head3 Results
2223		2651
2224	name sockets create request	2652	name sockets create request
2225	EV 20000 69.01 11.16	2653	EV 20000 62.66 7.99
2226	Perl 20000 73.32 35.87	2654	Perl 20000 68.32 32.64
2227	IOAsync 20000 157.00 98.14 epoll	2655	IOAsync 20000 174.06 101.15 epoll
2228	IOAsync 20000 159.31 616.06 poll	2656	IOAsync 20000 174.67 610.84 poll
2229	Event 20000 212.62 257.32	2657	Event 20000 202.69 242.91
2230	Glib 20000 651.16 1896.30	2658	Glib 20000 557.01 1689.52
2231	POE 20000 349.67 12317.24 uses POE::Loop::Event	2659	POE 20000 341.54 12086.32 uses POE::Loop::Event
2232		2660
2233	=head3 Discussion	2661	=head3 Discussion
2234		2662
2235	This benchmark I<does> measure scalability and overall performance of the	2663	This benchmark I<does> measure scalability and overall performance of the
2236	particular event loop.	2664	particular event loop.
…		…
2362	As you can see, the AnyEvent + EV combination even beats the	2790	As you can see, the AnyEvent + EV combination even beats the
2363	hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl	2791	hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl
2364	backend easily beats IO::Lambda and POE.	2792	backend easily beats IO::Lambda and POE.
2365		2793
2366	And even the 100% non-blocking version written using the high-level (and	2794	And even the 100% non-blocking version written using the high-level (and
2367	slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda by a	2795	slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda
2368	large margin, even though it does all of DNS, tcp-connect and socket I/O	2796	higher level ("unoptimised") abstractions by a large margin, even though
2369	in a non-blocking way.	2797	it does all of DNS, tcp-connect and socket I/O in a non-blocking way.
2370		2798
2371	The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and	2799	The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and
2372	F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are	2800	F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are
2373	part of the IO::lambda distribution and were used without any changes.	2801	part of the IO::Lambda distribution and were used without any changes.
2374		2802
2375		2803
2376	=head1 SIGNALS	2804	=head1 SIGNALS
2377		2805
2378	AnyEvent currently installs handlers for these signals:	2806	AnyEvent currently installs handlers for these signals:
…		…
2415	unless defined $SIG{PIPE};	2843	unless defined $SIG{PIPE};
2416		2844
2417	=head1 RECOMMENDED/OPTIONAL MODULES	2845	=head1 RECOMMENDED/OPTIONAL MODULES
2418		2846
2419	One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and	2847	One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and
2420	it's built-in modules) are required to use it.	2848	its built-in modules) are required to use it.
2421		2849
2422	That does not mean that AnyEvent won't take advantage of some additional	2850	That does not mean that AnyEvent won't take advantage of some additional
2423	modules if they are installed.	2851	modules if they are installed.
2424		2852
2425	This section epxlains which additional modules will be used, and how they	2853	This section explains which additional modules will be used, and how they
2426	affect AnyEvent's operetion.	2854	affect AnyEvent's operation.
2427		2855
2428	=over 4	2856	=over 4
2429		2857
2430	=item L<Async::Interrupt>	2858	=item L<Async::Interrupt>
2431		2859
…		…
2436	catch the signals) with some delay (default is 10 seconds, look for	2864	catch the signals) with some delay (default is 10 seconds, look for
2437	C<$AnyEvent::MAX_SIGNAL_LATENCY>).	2865	C<$AnyEvent::MAX_SIGNAL_LATENCY>).
2438		2866
2439	If this module is available, then it will be used to implement signal	2867	If this module is available, then it will be used to implement signal
2440	catching, which means that signals will not be delayed, and the event loop	2868	catching, which means that signals will not be delayed, and the event loop
2441	will not be interrupted regularly, which is more efficient (And good for	2869	will not be interrupted regularly, which is more efficient (and good for
2442	battery life on laptops).	2870	battery life on laptops).
2443		2871
2444	This affects not just the pure-perl event loop, but also other event loops	2872	This affects not just the pure-perl event loop, but also other event loops
2445	that have no signal handling on their own (e.g. Glib, Tk, Qt).	2873	that have no signal handling on their own (e.g. Glib, Tk, Qt).
2446		2874
…		…
2458	automatic timer adjustments even when no monotonic clock is available,	2886	automatic timer adjustments even when no monotonic clock is available,
2459	can take avdantage of advanced kernel interfaces such as C<epoll> and	2887	can take avdantage of advanced kernel interfaces such as C<epoll> and
2460	C<kqueue>, and is the fastest backend I<by far>. You can even embed	2888	C<kqueue>, and is the fastest backend I<by far>. You can even embed
2461	L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>).	2889	L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>).
2462		2890
		2891	If you only use backends that rely on another event loop (e.g. C<Tk>),
		2892	then this module will do nothing for you.
		2893
2463	=item L<Guard>	2894	=item L<Guard>
2464		2895
2465	The guard module, when used, will be used to implement	2896	The guard module, when used, will be used to implement
2466	C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a	2897	C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a
2467	lot less memory), but otherwise doesn't affect guard operation much. It is	2898	lot less memory), but otherwise doesn't affect guard operation much. It is
2468	purely used for performance.	2899	purely used for performance.
2469		2900
2470	=item L<JSON> and L<JSON::XS>	2901	=item L<JSON> and L<JSON::XS>
2471		2902
2472	This module is required when you want to read or write JSON data via	2903	One of these modules is required when you want to read or write JSON data
2473	L<AnyEvent::Handle>. It is also written in pure-perl, but can take	2904	via L<AnyEvent::Handle>. L<JSON> is also written in pure-perl, but can take
2474	advantage of the ultra-high-speed L<JSON::XS> module when it is installed.	2905	advantage of the ultra-high-speed L<JSON::XS> module when it is installed.
2475
2476	In fact, L<AnyEvent::Handle> will use L<JSON::XS> by default if it is
2477	installed.
2478		2906
2479	=item L<Net::SSLeay>	2907	=item L<Net::SSLeay>
2480		2908
2481	Implementing TLS/SSL in Perl is certainly interesting, but not very	2909	Implementing TLS/SSL in Perl is certainly interesting, but not very
2482	worthwhile: If this module is installed, then L<AnyEvent::Handle> (with	2910	worthwhile: If this module is installed, then L<AnyEvent::Handle> (with
2483	the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL.	2911	the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL.
2484		2912
2485	=item L<Time::HiRes>	2913	=item L<Time::HiRes>
2486		2914
2487	This module is part of perl since release 5.008. It will be used when the	2915	This module is part of perl since release 5.008. It will be used when the
2488	chosen event library does not come with a timing source on it's own. The	2916	chosen event library does not come with a timing source of its own. The
2489	pure-perl event loop (L<AnyEvent::Impl::Perl>) will additionally use it to	2917	pure-perl event loop (L<AnyEvent::Loop>) will additionally load it to
2490	try to use a monotonic clock for timing stability.	2918	try to use a monotonic clock for timing stability.
2491		2919
2492	=back	2920	=back
2493		2921
2494		2922
2495	=head1 FORK	2923	=head1 FORK
2496		2924
2497	Most event libraries are not fork-safe. The ones who are usually are	2925	Most event libraries are not fork-safe. The ones who are usually are
2498	because they rely on inefficient but fork-safe C<select> or C<poll>	2926	because they rely on inefficient but fork-safe C<select> or C<poll> calls
2499	calls. Only L<EV> is fully fork-aware.	2927	- higher performance APIs such as BSD's kqueue or the dreaded Linux epoll
		2928	are usually badly thought-out hacks that are incompatible with fork in
		2929	one way or another. Only L<EV> is fully fork-aware and ensures that you
		2930	continue event-processing in both parent and child (or both, if you know
		2931	what you are doing).
		2932
		2933	This means that, in general, you cannot fork and do event processing in
		2934	the child if the event library was initialised before the fork (which
		2935	usually happens when the first AnyEvent watcher is created, or the library
		2936	is loaded).
2500		2937
2501	If you have to fork, you must either do so I<before> creating your first	2938	If you have to fork, you must either do so I<before> creating your first
2502	watcher OR you must not use AnyEvent at all in the child OR you must do	2939	watcher OR you must not use AnyEvent at all in the child OR you must do
2503	something completely out of the scope of AnyEvent.	2940	something completely out of the scope of AnyEvent.
		2941
		2942	The problem of doing event processing in the parent I<and> the child
		2943	is much more complicated: even for backends that I<are> fork-aware or
		2944	fork-safe, their behaviour is not usually what you want: fork clones all
		2945	watchers, that means all timers, I/O watchers etc. are active in both
		2946	parent and child, which is almost never what you want. USing C<exec>
		2947	to start worker children from some kind of manage rprocess is usually
		2948	preferred, because it is much easier and cleaner, at the expense of having
		2949	to have another binary.
2504		2950
2505		2951
2506	=head1 SECURITY CONSIDERATIONS	2952	=head1 SECURITY CONSIDERATIONS
2507		2953
2508	AnyEvent can be forced to load any event model via	2954	AnyEvent can be forced to load any event model via
…		…
2538	pronounced).	2984	pronounced).
2539		2985
2540		2986
2541	=head1 SEE ALSO	2987	=head1 SEE ALSO
2542		2988
2543	Utility functions: L<AnyEvent::Util>.	2989	Tutorial/Introduction: L<AnyEvent::Intro>.
2544		2990
2545	Event modules: L<EV>, L<EV::Glib>, L<Glib::EV>, L<Event>, L<Glib::Event>,	2991	FAQ: L<AnyEvent::FAQ>.
2546	L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.	2992
		2993	Utility functions: L<AnyEvent::Util> (misc. grab-bag), L<AnyEvent::Log>
		2994	(simply logging).
		2995
		2996	Development/Debugging: L<AnyEvent::Strict> (stricter checking),
		2997	L<AnyEvent::Debug> (interactive shell, watcher tracing).
		2998
		2999	Supported event modules: L<AnyEvent::Loop>, L<EV>, L<EV::Glib>,
		3000	L<Glib::EV>, L<Event>, L<Glib::Event>, L<Glib>, L<Tk>, L<Event::Lib>,
		3001	L<Qt>, L<POE>, L<FLTK>.
2547		3002
2548	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,	3003	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,
2549	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,	3004	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,
2550	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,	3005	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,
2551	L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>, L<Anyevent::Impl::Irssi>.	3006	L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>, L<Anyevent::Impl::Irssi>,
		3007	L<AnyEvent::Impl::FLTK>.
2552		3008
2553	Non-blocking file handles, sockets, TCP clients and	3009	Non-blocking handles, pipes, stream sockets, TCP clients and
2554	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.	3010	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.
2555		3011
2556	Asynchronous DNS: L<AnyEvent::DNS>.	3012	Asynchronous DNS: L<AnyEvent::DNS>.
2557		3013
2558	Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>,	3014	Thread support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>.
2559	L<Coro::Event>,
2560		3015
2561	Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::XMPP>,	3016	Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::IRC>,
2562	L<AnyEvent::HTTP>.	3017	L<AnyEvent::HTTP>.
2563		3018
2564		3019
2565	=head1 AUTHOR	3020	=head1 AUTHOR
2566		3021

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