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Revision 1.266 by root, Thu Jul 30 03:41:56 2009 UTC vs.
Revision 1.333 by root, Tue Oct 12 06:47:54 2010 UTC

…		…
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
…		…
73	module users into the same thing by forcing them to use the same event	76	module users into the same thing by forcing them to use the same event
74	model you use.	77	model you use.
75		78
76	For modules like POE or IO::Async (which is a total misnomer as it is	79	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	80	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	81	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	82	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	83	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.	84	module are I<also> forced to use the same event loop you use.
82		85
83	AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works	86	AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works
84	fine. AnyEvent + Tk works fine etc. etc. but none of these work together	87	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	88	with the rest: POE + IO::Async? No go. Tk + Event? No go. Again: if
86	your module uses one of those, every user of your module has to use it,	89	your module uses one of those, every user of your module has to use it,
87	too. But if your module uses AnyEvent, it works transparently with all	90	too. But if your module uses AnyEvent, it works transparently with all
88	event models it supports (including stuff like IO::Async, as long as those	91	event models it supports (including stuff like IO::Async, as long as those
89	use one of the supported event loops. It is trivial to add new event loops	92	use one of the supported event loops. It is easy to add new event loops
90	to AnyEvent, too, so it is future-proof).	93	to AnyEvent, too, so it is future-proof).
91		94
92	In addition to being free of having to use I<the one and only true event	95	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	96	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	97	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	98	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	99	offering the functionality that is necessary, in as thin as a wrapper as
97	technically possible.	100	technically possible.
98		101
99	Of course, AnyEvent comes with a big (and fully optional!) toolbox	102	Of course, AnyEvent comes with a big (and fully optional!) toolbox
100	of useful functionality, such as an asynchronous DNS resolver, 100%	103	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	109	useful) and you want to force your users to use the one and only event
107	model, you should I<not> use this module.	110	model, you should I<not> use this module.
108		111
109	=head1 DESCRIPTION	112	=head1 DESCRIPTION
110		113
111	L<AnyEvent> provides an identical interface to multiple event loops. This	114	L<AnyEvent> provides a uniform interface to various event loops. This
112	allows module authors to utilise an event loop without forcing module	115	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	116	module users to use a specific event loop implementation (since more
114	peacefully at any one time).	117	than one event loop cannot coexist peacefully).
115		118
116	The interface itself is vaguely similar, but not identical to the L<Event>	119	The interface itself is vaguely similar, but not identical to the L<Event>
117	module.	120	module.
118		121
119	During the first call of any watcher-creation method, the module tries	122	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	123	to detect the currently loaded event loop by probing whether one of the
121	following modules is already loaded: L<EV>,	124	following modules is already loaded: L<EV>, L<AnyEvent::Impl::Perl>,
122	L<Event>, L<Glib>, L<AnyEvent::Impl::Perl>, L<Tk>, L<Event::Lib>, L<Qt>,	125	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	126	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	127	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	128	available, the pure-perl L<AnyEvent::Impl::Perl> should always work, so
126	be successfully loaded will be used. If, after this, still none could be	129	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		130
130	Because AnyEvent first checks for modules that are already loaded, loading	131	Because AnyEvent first checks for modules that are already loaded, loading
131	an event model explicitly before first using AnyEvent will likely make	132	an event model explicitly before first using AnyEvent will likely make
132	that model the default. For example:	133	that model the default. For example:
133		134
…		…
135	use AnyEvent;	136	use AnyEvent;
136		137
137	# .. AnyEvent will likely default to Tk	138	# .. AnyEvent will likely default to Tk
138		139
139	The I<likely> means that, if any module loads another event model and	140	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	141	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...	142	as very few modules hardcode event loops without announcing this very
		143	loudly.
142		144
143	The pure-perl implementation of AnyEvent is called	145	The pure-perl implementation of AnyEvent is called
144	C<AnyEvent::Impl::Perl>. Like other event modules you can load it	146	C<AnyEvent::Impl::Perl>. Like other event modules you can load it
145	explicitly and enjoy the high availability of that event loop :)	147	explicitly and enjoy the high availability of that event loop :)
146		148
…		…
155	callback when the event occurs (of course, only when the event model	157	callback when the event occurs (of course, only when the event model
156	is in control).	158	is in control).
157		159
158	Note that B<callbacks must not permanently change global variables>	160	Note that B<callbacks must not permanently change global variables>
159	potentially in use by the event loop (such as C<$_> or C<$[>) and that B<<	161	potentially in use by the event loop (such as C<$_> or C<$[>) and that B<<
160	callbacks must not C<die> >>. The former is good programming practise in	162	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	163	Perl and the latter stems from the fact that exception handling differs
162	widely between event loops.	164	widely between event loops.
163		165
164	To disable the watcher you have to destroy it (e.g. by setting the	166	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	167	variable you store it in to C<undef> or otherwise deleting all references
166	to it).	168	to it).
167		169
168	All watchers are created by calling a method on the C<AnyEvent> class.	170	All watchers are created by calling a method on the C<AnyEvent> class.
169		171
170	Many watchers either are used with "recursion" (repeating timers for	172	Many watchers either are used with "recursion" (repeating timers for
171	example), or need to refer to their watcher object in other ways.	173	example), or need to refer to their watcher object in other ways.
172		174
173	An any way to achieve that is this pattern:	175	One way to achieve that is this pattern:
174		176
175	my $w; $w = AnyEvent->type (arg => value ..., cb => sub {	177	my $w; $w = AnyEvent->type (arg => value ..., cb => sub {
176	# you can use $w here, for example to undef it	178	# you can use $w here, for example to undef it
177	undef $w;	179	undef $w;
178	});	180	});
…		…
210		212
211	The I/O watcher might use the underlying file descriptor or a copy of it.	213	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	214	You must not close a file handle as long as any watcher is active on the
213	underlying file descriptor.	215	underlying file descriptor.
214		216
215	Some event loops issue spurious readyness notifications, so you should	217	Some event loops issue spurious readiness notifications, so you should
216	always use non-blocking calls when reading/writing from/to your file	218	always use non-blocking calls when reading/writing from/to your file
217	handles.	219	handles.
218		220
219	Example: wait for readability of STDIN, then read a line and disable the	221	Example: wait for readability of STDIN, then read a line and disable the
220	watcher.	222	watcher.
…		…
244		246
245	Although the callback might get passed parameters, their value and	247	Although the callback might get passed parameters, their value and
246	presence is undefined and you cannot rely on them. Portable AnyEvent	248	presence is undefined and you cannot rely on them. Portable AnyEvent
247	callbacks cannot use arguments passed to time watcher callbacks.	249	callbacks cannot use arguments passed to time watcher callbacks.
248		250
249	The callback will normally be invoked once only. If you specify another	251	The callback will normally be invoked only once. If you specify another
250	parameter, C<interval>, as a strictly positive number (> 0), then the	252	parameter, C<interval>, as a strictly positive number (> 0), then the
251	callback will be invoked regularly at that interval (in fractional	253	callback will be invoked regularly at that interval (in fractional
252	seconds) after the first invocation. If C<interval> is specified with a	254	seconds) after the first invocation. If C<interval> is specified with a
253	false value, then it is treated as if it were missing.	255	false value, then it is treated as if it were not specified at all.
254		256
255	The callback will be rescheduled before invoking the callback, but no	257	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	258	attempt is made to avoid timer drift in most backends, so the interval is
257	only approximate.	259	only approximate.
258		260
259	Example: fire an event after 7.7 seconds.	261	Example: fire an event after 7.7 seconds.
260		262
261	my $w = AnyEvent->timer (after => 7.7, cb => sub {	263	my $w = AnyEvent->timer (after => 7.7, cb => sub {
…		…
279		281
280	While most event loops expect timers to specified in a relative way, they	282	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	283	use absolute time internally. This makes a difference when your clock
282	"jumps", for example, when ntp decides to set your clock backwards from	284	"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	285	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.	286	fire "after a second" might actually take six years to finally fire.
285		287
286	AnyEvent cannot compensate for this. The only event loop that is conscious	288	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	289	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)	290	on true relative time) and absolute (ev_periodic, based on wallclock time)
289	timers.	291	timers.
290		292
291	AnyEvent always prefers relative timers, if available, matching the	293	AnyEvent always prefers relative timers, if available, matching the
292	AnyEvent API.	294	AnyEvent API.
…		…
314	I<In almost all cases (in all cases if you don't care), this is the	316	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.>	317	function to call when you want to know the current time.>
316		318
317	This function is also often faster then C<< AnyEvent->time >>, and	319	This function is also often faster then C<< AnyEvent->time >>, and
318	thus the preferred method if you want some timestamp (for example,	320	thus the preferred method if you want some timestamp (for example,
319	L<AnyEvent::Handle> uses this to update it's activity timeouts).	321	L<AnyEvent::Handle> uses this to update its activity timeouts).
320		322
321	The rest of this section is only of relevance if you try to be very exact	323	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.	324	with your timing; you can skip it without a bad conscience.
323		325
324	For a practical example of when these times differ, consider L<Event::Lib>	326	For a practical example of when these times differ, consider L<Event::Lib>
325	and L<EV> and the following set-up:	327	and L<EV> and the following set-up:
326		328
327	The event loop is running and has just invoked one of your callback at	329	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,	330	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	331	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	332	second) and then (at time=501) you create a relative timer that fires
331	after three seconds.	333	after three seconds.
332		334
…		…
363	might affect timers and time-outs.	365	might affect timers and time-outs.
364		366
365	When this is the case, you can call this method, which will update the	367	When this is the case, you can call this method, which will update the
366	event loop's idea of "current time".	368	event loop's idea of "current time".
367		369
		370	A typical example would be a script in a web server (e.g. C<mod_perl>) -
		371	when mod_perl executes the script, then the event loop will have the wrong
		372	idea about the "current time" (being potentially far in the past, when the
		373	script ran the last time). In that case you should arrange a call to C<<
		374	AnyEvent->now_update >> each time the web server process wakes up again
		375	(e.g. at the start of your script, or in a handler).
		376
368	Note that updating the time I<might> cause some events to be handled.	377	Note that updating the time I<might> cause some events to be handled.
369		378
370	=back	379	=back
371		380
372	=head2 SIGNAL WATCHERS	381	=head2 SIGNAL WATCHERS
…		…
396		405
397	Example: exit on SIGINT	406	Example: exit on SIGINT
398		407
399	my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });	408	my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });
400		409
		410	=head3 Restart Behaviour
		411
		412	While restart behaviour is up to the event loop implementation, most will
		413	not restart syscalls (that includes L<Async::Interrupt> and AnyEvent's
		414	pure perl implementation).
		415
		416	=head3 Safe/Unsafe Signals
		417
		418	Perl signals can be either "safe" (synchronous to opcode handling) or
		419	"unsafe" (asynchronous) - the former might get delayed indefinitely, the
		420	latter might corrupt your memory.
		421
		422	AnyEvent signal handlers are, in addition, synchronous to the event loop,
		423	i.e. they will not interrupt your running perl program but will only be
		424	called as part of the normal event handling (just like timer, I/O etc.
		425	callbacks, too).
		426
401	=head3 Signal Races, Delays and Workarounds	427	=head3 Signal Races, Delays and Workarounds
402		428
403	Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support attaching	429	Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support attaching
404	callbacks to signals in a generic way, which is a pity, as you cannot do	430	callbacks to signals in a generic way, which is a pity, as you cannot
405	race-free signal handling in perl. AnyEvent will try to do it's best, but	431	do race-free signal handling in perl, requiring C libraries for
		432	this. AnyEvent will try to do its best, which means in some cases,
406	in some cases, signals will be delayed. The maximum time a signal might	433	signals will be delayed. The maximum time a signal might be delayed is
407	be delayed is specified in C<$AnyEvent::MAX_SIGNAL_LATENCY> (default: 10	434	specified in C<$AnyEvent::MAX_SIGNAL_LATENCY> (default: 10 seconds). This
408	seconds). This variable can be changed only before the first signal	435	variable can be changed only before the first signal watcher is created,
409	watcher is created, and should be left alone otherwise. Higher values	436	and should be left alone otherwise. This variable determines how often
		437	AnyEvent polls for signals (in case a wake-up was missed). Higher values
410	will cause fewer spurious wake-ups, which is better for power and CPU	438	will cause fewer spurious wake-ups, which is better for power and CPU
		439	saving.
		440
411	saving. All these problems can be avoided by installing the optional	441	All these problems can be avoided by installing the optional
412	L<Async::Interrupt> module. This will not work with inherently broken	442	L<Async::Interrupt> module, which works with most event loops. It will not
413	event loops such as L<Event> or L<Event::Lib> (and not with L<POE>	443	work with inherently broken event loops such as L<Event> or L<Event::Lib>
414	currently, as POE does it's own workaround with one-second latency). With	444	(and not with L<POE> currently, as POE does its own workaround with
415	those, you just have to suffer the delays.	445	one-second latency). For those, you just have to suffer the delays.
416		446
417	=head2 CHILD PROCESS WATCHERS	447	=head2 CHILD PROCESS WATCHERS
418		448
419	$w = AnyEvent->child (pid => <process id>, cb => <callback>);	449	$w = AnyEvent->child (pid => <process id>, cb => <callback>);
420		450
421	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.
422		452
423	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,
424	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
425	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
426	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
427	(stopped/continued).	457	(stopped/continued).
428		458
…		…
475		505
476	=head2 IDLE WATCHERS	506	=head2 IDLE WATCHERS
477		507
478	$w = AnyEvent->idle (cb => <callback>);	508	$w = AnyEvent->idle (cb => <callback>);
479		509
480	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,
481	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.
482	"nothing better to do" is usually defined to be "no other events need
483	attention by the event loop".
484		512
485	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
486	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
487	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.
488		521
489	Most event loops unfortunately do not really support idle watchers (only	522	Unfortunately, most event loops do not really support idle watchers (only
490	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
491	will simply call the callback "from time to time".	524	will simply call the callback "from time to time".
492		525
493	Example: read lines from STDIN, but only process them when the	526	Example: read lines from STDIN, but only process them when the
494	program is otherwise idle:	527	program is otherwise idle:
…		…
522	will actively watch for new events and call your callbacks.	555	will actively watch for new events and call your callbacks.
523		556
524	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
525	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).
526		559
527	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
528	because they represent a condition that must become true.	561	they represent a condition that must become true.
529		562
530	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.
531		564
532	Condition variables can be created by calling the C<< AnyEvent->condvar	565	Condition variables can be created by calling the C<< AnyEvent->condvar
533	>> method, usually without arguments. The only argument pair allowed is	566	>> method, usually without arguments. The only argument pair allowed is
…		…
538	After creation, the condition variable is "false" until it becomes "true"	571	After creation, the condition variable is "false" until it becomes "true"
539	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
540	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<<
541	->send >> method).	574	->send >> method).
542		575
543	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
544	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:
545	in time where multiple outstanding events have been processed. And yet	578
546	another way to call them is transactions - each condition variable can be	579	=over 4
547	used to represent a transaction, which finishes at some point and delivers	580
548	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
549	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
550		599
551	Condition variables are very useful to signal that something has finished,	600	Condition variables are very useful to signal that something has finished,
552	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,
553	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
554	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
…		…
567		616
568	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
569	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
570	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
571	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
572	it's C<new> method in your own C<new> method.	621	its C<new> method in your own C<new> method.
573		622
574	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
575	eventually calls C<< -> send >>, and the "consumer side", which waits	624	eventually calls C<< -> send >>, and the "consumer side", which waits
576	for the send to occur.	625	for the send to occur.
577		626
578	Example: wait for a timer.	627	Example: wait for a timer.
579		628
580	# wait till the result is ready	629	# condition: "wait till the timer is fired"
581	my $result_ready = AnyEvent->condvar;	630	my $timer_fired = AnyEvent->condvar;
582		631
583	# do something such as adding a timer	632	# create the timer - we could wait for, say
584	# or socket watcher the calls $result_ready->send	633	# a handle becomign ready, or even an
585	# when the "result" is ready.	634	# AnyEvent::HTTP request to finish, but
586	# in this case, we simply use a timer:	635	# in this case, we simply use a timer:
587	my $w = AnyEvent->timer (	636	my $w = AnyEvent->timer (
588	after => 1,	637	after => 1,
589	cb => sub { $result_ready->send },	638	cb => sub { $timer_fired->send },
590	);	639	);
591		640
592	# this "blocks" (while handling events) till the callback	641	# this "blocks" (while handling events) till the callback
593	# calls -<send	642	# calls ->send
594	$result_ready->recv;	643	$timer_fired->recv;
595		644
596	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
597	variables are also callable directly.	646	variables are also callable directly.
598		647
599	my $done = AnyEvent->condvar;	648	my $done = AnyEvent->condvar;
…		…
642	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
643	C<send>.	692	C<send>.
644		693
645	=item $cv->croak ($error)	694	=item $cv->croak ($error)
646		695
647	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
648	C<Carp::croak> with the given error message/object/scalar.	697	C<Carp::croak> with the given error message/object/scalar.
649		698
650	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
651	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
652	delays the error detetcion, but has the overwhelmign advantage that it	701	delays the error detection, but has the overwhelming advantage that it
653	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
654	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
655	the problem.	704	the problem.
656		705
657	=item $cv->begin ([group callback])	706	=item $cv->begin ([group callback])
658		707
659	=item $cv->end	708	=item $cv->end
…		…
662	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
663	to use a condition variable for the whole process.	712	to use a condition variable for the whole process.
664		713
665	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
666	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
667	>>, 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
668	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
669	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.
670		720
671	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
672	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
673	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).
674		724
…		…
696	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
697	sending.	747	sending.
698		748
699	The ping example mentioned above is slightly more complicated, as the	749	The ping example mentioned above is slightly more complicated, as the
700	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
701	begung can potentially be zero:	751	begun can potentially be zero:
702		752
703	my $cv = AnyEvent->condvar;	753	my $cv = AnyEvent->condvar;
704		754
705	my %result;	755	my %result;
706	$cv->begin (sub { $cv->send (\%result) });	756	$cv->begin (sub { shift->send (\%result) });
707		757
708	for my $host (@list_of_hosts) {	758	for my $host (@list_of_hosts) {
709	$cv->begin;	759	$cv->begin;
710	ping_host_then_call_callback $host, sub {	760	ping_host_then_call_callback $host, sub {
711	$result{$host} = ...;	761	$result{$host} = ...;
…		…
727	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
728	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
729	doesn't execute once).	779	doesn't execute once).
730		780
731	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
732	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
733	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
734	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,
735	call C<end>.	785	call C<end>.
736		786
737	=back	787	=back
…		…
744	=over 4	794	=over 4
745		795
746	=item $cv->recv	796	=item $cv->recv
747		797
748	Wait (blocking if necessary) until the C<< ->send >> or C<< ->croak	798	Wait (blocking if necessary) until the C<< ->send >> or C<< ->croak
749	>> methods have been called on c<$cv>, while servicing other watchers	799	>> methods have been called on C<$cv>, while servicing other watchers
750	normally.	800	normally.
751		801
752	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
753	will return immediately.	803	will return immediately.
754		804
…		…
771	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
772	condition variables with some kind of request results and supporting	822	condition variables with some kind of request results and supporting
773	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,
774	while still supporting blocking waits if the caller so desires).	824	while still supporting blocking waits if the caller so desires).
775		825
776	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
777	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
778	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
779	waits otherwise.	829	waits otherwise.
780		830
781	=item $bool = $cv->ready	831	=item $bool = $cv->ready
…		…
787		837
788	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
789	replaces it before doing so.	839	replaces it before doing so.
790		840
791	The callback will be called when the condition becomes "true", i.e. when	841	The callback will be called when the condition becomes "true", i.e. when
792	C<send> or C<croak> are called, with the only argument being the condition	842	C<send> or C<croak> are called, with the only argument being the
793	variable itself. Calling C<recv> inside the callback or at any later time	843	condition variable itself. If the condition is already true, the
794	is guaranteed not to block.	844	callback is called immediately when it is set. Calling C<recv> inside
		845	the callback or at any later time is guaranteed not to block.
795		846
796	=back	847	=back
797		848
798	=head1 SUPPORTED EVENT LOOPS/BACKENDS	849	=head1 SUPPORTED EVENT LOOPS/BACKENDS
799		850
…		…
802	=over 4	853	=over 4
803		854
804	=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.
805		856
806	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
807	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
808	that, will fall back to its own pure-perl implementation, which is	859	pure-perl implementation, which is available everywhere as it comes with
809	available everywhere as it comes with AnyEvent itself.	860	AnyEvent itself.
810		861
811	AnyEvent::Impl::EV based on EV (interface to libev, best choice).	862	AnyEvent::Impl::EV based on EV (interface to libev, best choice).
812	AnyEvent::Impl::Event based on Event, very stable, few glitches.
813	AnyEvent::Impl::Perl pure-perl implementation, fast and portable.	863	AnyEvent::Impl::Perl pure-perl implementation, fast and portable.
814		864
815	=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.
816		866
817	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
818	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
819	them. This means that AnyEvent will automatically pick the right backend	869	them. This means that AnyEvent will automatically pick the right backend
820	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
821	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.
822		872
		873	AnyEvent::Impl::Event based on Event, very stable, few glitches.
823	AnyEvent::Impl::Glib based on Glib, slow but very stable.	874	AnyEvent::Impl::Glib based on Glib, slow but very stable.
824	AnyEvent::Impl::Tk based on Tk, very broken.	875	AnyEvent::Impl::Tk based on Tk, very broken.
825	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.	876	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
826	AnyEvent::Impl::POE based on POE, very slow, some limitations.	877	AnyEvent::Impl::POE based on POE, very slow, some limitations.
827	AnyEvent::Impl::Irssi used when running within irssi.	878	AnyEvent::Impl::Irssi used when running within irssi.
…		…
837		888
838	Support for IO::Async can only be partial, as it is too broken and	889	Support for IO::Async can only be partial, as it is too broken and
839	architecturally limited to even support the AnyEvent API. It also	890	architecturally limited to even support the AnyEvent API. It also
840	is the only event loop that needs the loop to be set explicitly, so	891	is the only event loop that needs the loop to be set explicitly, so
841	it can only be used by a main program knowing about AnyEvent. See	892	it can only be used by a main program knowing about AnyEvent. See
842	L<AnyEvent::Impl::Async> for the gory details.	893	L<AnyEvent::Impl::IOAsync> for the gory details.
843		894
844	AnyEvent::Impl::IOAsync based on IO::Async, cannot be autoprobed.	895	AnyEvent::Impl::IOAsync based on IO::Async, cannot be autoprobed.
845		896
846	=item Event loops that are indirectly supported via other backends.	897	=item Event loops that are indirectly supported via other backends.
847		898
…		…
875	Contains C<undef> until the first watcher is being created, before the	926	Contains C<undef> until the first watcher is being created, before the
876	backend has been autodetected.	927	backend has been autodetected.
877		928
878	Afterwards it contains the event model that is being used, which is the	929	Afterwards it contains the event model that is being used, which is the
879	name of the Perl class implementing the model. This class is usually one	930	name of the Perl class implementing the model. This class is usually one
880	of the C<AnyEvent::Impl:xxx> modules, but can be any other class in the	931	of the C<AnyEvent::Impl::xxx> modules, but can be any other class in the
881	case AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode> it	932	case AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode> it
882	will be C<urxvt::anyevent>).	933	will be C<urxvt::anyevent>).
883		934
884	=item AnyEvent::detect	935	=item AnyEvent::detect
885		936
886	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model	937	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model
887	if necessary. You should only call this function right before you would	938	if necessary. You should only call this function right before you would
888	have created an AnyEvent watcher anyway, that is, as late as possible at	939	have created an AnyEvent watcher anyway, that is, as late as possible at
889	runtime, and not e.g. while initialising of your module.	940	runtime, and not e.g. during initialisation of your module.
890		941
891	If you need to do some initialisation before AnyEvent watchers are	942	If you need to do some initialisation before AnyEvent watchers are
892	created, use C<post_detect>.	943	created, use C<post_detect>.
893		944
894	=item $guard = AnyEvent::post_detect { BLOCK }	945	=item $guard = AnyEvent::post_detect { BLOCK }
895		946
896	Arranges for the code block to be executed as soon as the event model is	947	Arranges for the code block to be executed as soon as the event model is
897	autodetected (or immediately if this has already happened).	948	autodetected (or immediately if that has already happened).
898		949
899	The block will be executed I<after> the actual backend has been detected	950	The block will be executed I<after> the actual backend has been detected
900	(C<$AnyEvent::MODEL> is set), but I<before> any watchers have been	951	(C<$AnyEvent::MODEL> is set), but I<before> any watchers have been
901	created, so it is possible to e.g. patch C<@AnyEvent::ISA> or do	952	created, so it is possible to e.g. patch C<@AnyEvent::ISA> or do
902	other initialisations - see the sources of L<AnyEvent::Strict> or	953	other initialisations - see the sources of L<AnyEvent::Strict> or
…		…
911	that automatically removes the callback again when it is destroyed (or	962	that automatically removes the callback again when it is destroyed (or
912	C<undef> when the hook was immediately executed). See L<AnyEvent::AIO> for	963	C<undef> when the hook was immediately executed). See L<AnyEvent::AIO> for
913	a case where this is useful.	964	a case where this is useful.
914		965
915	Example: Create a watcher for the IO::AIO module and store it in	966	Example: Create a watcher for the IO::AIO module and store it in
916	C<$WATCHER>. Only do so after the event loop is initialised, though.	967	C<$WATCHER>, but do so only do so after the event loop is initialised.
917		968
918	our WATCHER;	969	our WATCHER;
919		970
920	my $guard = AnyEvent::post_detect {	971	my $guard = AnyEvent::post_detect {
921	$WATCHER = AnyEvent->io (fh => IO::AIO::poll_fileno, poll => 'r', cb => \&IO::AIO::poll_cb);	972	$WATCHER = AnyEvent->io (fh => IO::AIO::poll_fileno, poll => 'r', cb => \&IO::AIO::poll_cb);
…		…
929	$WATCHER ||= $guard;	980	$WATCHER ||= $guard;
930		981
931	=item @AnyEvent::post_detect	982	=item @AnyEvent::post_detect
932		983
933	If there are any code references in this array (you can C<push> to it	984	If there are any code references in this array (you can C<push> to it
934	before or after loading AnyEvent), then they will called directly after	985	before or after loading AnyEvent), then they will be called directly
935	the event loop has been chosen.	986	after the event loop has been chosen.
936		987
937	You should check C<$AnyEvent::MODEL> before adding to this array, though:	988	You should check C<$AnyEvent::MODEL> before adding to this array, though:
938	if it is defined then the event loop has already been detected, and the	989	if it is defined then the event loop has already been detected, and the
939	array will be ignored.	990	array will be ignored.
940		991
941	Best use C<AnyEvent::post_detect { BLOCK }> when your application allows	992	Best use C<AnyEvent::post_detect { BLOCK }> when your application allows
942	it,as it takes care of these details.	993	it, as it takes care of these details.
943		994
944	This variable is mainly useful for modules that can do something useful	995	This variable is mainly useful for modules that can do something useful
945	when AnyEvent is used and thus want to know when it is initialised, but do	996	when AnyEvent is used and thus want to know when it is initialised, but do
946	not need to even load it by default. This array provides the means to hook	997	not need to even load it by default. This array provides the means to hook
947	into AnyEvent passively, without loading it.	998	into AnyEvent passively, without loading it.
948		999
		1000	Example: To load Coro::AnyEvent whenever Coro and AnyEvent are used
		1001	together, you could put this into Coro (this is the actual code used by
		1002	Coro to accomplish this):
		1003
		1004	if (defined $AnyEvent::MODEL) {
		1005	# AnyEvent already initialised, so load Coro::AnyEvent
		1006	require Coro::AnyEvent;
		1007	} else {
		1008	# AnyEvent not yet initialised, so make sure to load Coro::AnyEvent
		1009	# as soon as it is
		1010	push @AnyEvent::post_detect, sub { require Coro::AnyEvent };
		1011	}
		1012
949	=back	1013	=back
950		1014
951	=head1 WHAT TO DO IN A MODULE	1015	=head1 WHAT TO DO IN A MODULE
952		1016
953	As a module author, you should C<use AnyEvent> and call AnyEvent methods	1017	As a module author, you should C<use AnyEvent> and call AnyEvent methods
…		…
963	because it will stall the whole program, and the whole point of using	1027	because it will stall the whole program, and the whole point of using
964	events is to stay interactive.	1028	events is to stay interactive.
965		1029
966	It is fine, however, to call C<< ->recv >> when the user of your module	1030	It is fine, however, to call C<< ->recv >> when the user of your module
967	requests it (i.e. if you create a http request object ad have a method	1031	requests it (i.e. if you create a http request object ad have a method
968	called C<results> that returns the results, it should call C<< ->recv >>	1032	called C<results> that returns the results, it may call C<< ->recv >>
969	freely, as the user of your module knows what she is doing. always).	1033	freely, as the user of your module knows what she is doing. Always).
970		1034
971	=head1 WHAT TO DO IN THE MAIN PROGRAM	1035	=head1 WHAT TO DO IN THE MAIN PROGRAM
972		1036
973	There will always be a single main program - the only place that should	1037	There will always be a single main program - the only place that should
974	dictate which event model to use.	1038	dictate which event model to use.
975		1039
976	If it doesn't care, it can just "use AnyEvent" and use it itself, or not	1040	If the program is not event-based, it need not do anything special, even
977	do anything special (it does not need to be event-based) and let AnyEvent	1041	when it depends on a module that uses an AnyEvent. If the program itself
978	decide which implementation to chose if some module relies on it.	1042	uses AnyEvent, but does not care which event loop is used, all it needs
		1043	to do is C<use AnyEvent>. In either case, AnyEvent will choose the best
		1044	available loop implementation.
979		1045
980	If the main program relies on a specific event model - for example, in	1046	If the main program relies on a specific event model - for example, in
981	Gtk2 programs you have to rely on the Glib module - you should load the	1047	Gtk2 programs you have to rely on the Glib module - you should load the
982	event module before loading AnyEvent or any module that uses it: generally	1048	event module before loading AnyEvent or any module that uses it: generally
983	speaking, you should load it as early as possible. The reason is that	1049	speaking, you should load it as early as possible. The reason is that
984	modules might create watchers when they are loaded, and AnyEvent will	1050	modules might create watchers when they are loaded, and AnyEvent will
985	decide on the event model to use as soon as it creates watchers, and it	1051	decide on the event model to use as soon as it creates watchers, and it
986	might chose the wrong one unless you load the correct one yourself.	1052	might choose the wrong one unless you load the correct one yourself.
987		1053
988	You can chose to use a pure-perl implementation by loading the	1054	You can chose to use a pure-perl implementation by loading the
989	C<AnyEvent::Impl::Perl> module, which gives you similar behaviour	1055	C<AnyEvent::Impl::Perl> module, which gives you similar behaviour
990	everywhere, but letting AnyEvent chose the model is generally better.	1056	everywhere, but letting AnyEvent chose the model is generally better.
991		1057
…		…
1009	=head1 OTHER MODULES	1075	=head1 OTHER MODULES
1010		1076
1011	The following is a non-exhaustive list of additional modules that use	1077	The following is a non-exhaustive list of additional modules that use
1012	AnyEvent as a client and can therefore be mixed easily with other AnyEvent	1078	AnyEvent as a client and can therefore be mixed easily with other AnyEvent
1013	modules and other event loops in the same program. Some of the modules	1079	modules and other event loops in the same program. Some of the modules
1014	come with AnyEvent, most are available via CPAN.	1080	come as part of AnyEvent, the others are available via CPAN.
1015		1081
1016	=over 4	1082	=over 4
1017		1083
1018	=item L<AnyEvent::Util>	1084	=item L<AnyEvent::Util>
1019		1085
1020	Contains various utility functions that replace often-used but blocking	1086	Contains various utility functions that replace often-used blocking
1021	functions such as C<inet_aton> by event-/callback-based versions.	1087	functions such as C<inet_aton> with event/callback-based versions.
1022		1088
1023	=item L<AnyEvent::Socket>	1089	=item L<AnyEvent::Socket>
1024		1090
1025	Provides various utility functions for (internet protocol) sockets,	1091	Provides various utility functions for (internet protocol) sockets,
1026	addresses and name resolution. Also functions to create non-blocking tcp	1092	addresses and name resolution. Also functions to create non-blocking tcp
…		…
1028		1094
1029	=item L<AnyEvent::Handle>	1095	=item L<AnyEvent::Handle>
1030		1096
1031	Provide read and write buffers, manages watchers for reads and writes,	1097	Provide read and write buffers, manages watchers for reads and writes,
1032	supports raw and formatted I/O, I/O queued and fully transparent and	1098	supports raw and formatted I/O, I/O queued and fully transparent and
1033	non-blocking SSL/TLS (via L<AnyEvent::TLS>.	1099	non-blocking SSL/TLS (via L<AnyEvent::TLS>).
1034		1100
1035	=item L<AnyEvent::DNS>	1101	=item L<AnyEvent::DNS>
1036		1102
1037	Provides rich asynchronous DNS resolver capabilities.	1103	Provides rich asynchronous DNS resolver capabilities.
1038		1104
		1105	=item L<AnyEvent::HTTP>, L<AnyEvent::IRC>, L<AnyEvent::XMPP>, L<AnyEvent::GPSD>, L<AnyEvent::IGS>, L<AnyEvent::FCP>
		1106
		1107	Implement event-based interfaces to the protocols of the same name (for
		1108	the curious, IGS is the International Go Server and FCP is the Freenet
		1109	Client Protocol).
		1110
		1111	=item L<AnyEvent::Handle::UDP>
		1112
		1113	Here be danger!
		1114
		1115	As Pauli would put it, "Not only is it not right, it's not even wrong!" -
		1116	there are so many things wrong with AnyEvent::Handle::UDP, most notably
		1117	its use of a stream-based API with a protocol that isn't streamable, that
		1118	the only way to improve it is to delete it.
		1119
		1120	It features data corruption (but typically only under load) and general
		1121	confusion. On top, the author is not only clueless about UDP but also
		1122	fact-resistant - some gems of his understanding: "connect doesn't work
		1123	with UDP", "UDP packets are not IP packets", "UDP only has datagrams, not
		1124	packets", "I don't need to implement proper error checking as UDP doesn't
		1125	support error checking" and so on - he doesn't even understand what's
		1126	wrong with his module when it is explained to him.
		1127
1039	=item L<AnyEvent::HTTP>	1128	=item L<AnyEvent::DBI>
1040		1129
1041	A simple-to-use HTTP library that is capable of making a lot of concurrent	1130	Executes L<DBI> requests asynchronously in a proxy process for you,
1042	HTTP requests.	1131	notifying you in an event-based way when the operation is finished.
		1132
		1133	=item L<AnyEvent::AIO>
		1134
		1135	Truly asynchronous (as opposed to non-blocking) I/O, should be in the
		1136	toolbox of every event programmer. AnyEvent::AIO transparently fuses
		1137	L<IO::AIO> and AnyEvent together, giving AnyEvent access to event-based
		1138	file I/O, and much more.
1043		1139
1044	=item L<AnyEvent::HTTPD>	1140	=item L<AnyEvent::HTTPD>
1045		1141
1046	Provides a simple web application server framework.	1142	A simple embedded webserver.
1047		1143
1048	=item L<AnyEvent::FastPing>	1144	=item L<AnyEvent::FastPing>
1049		1145
1050	The fastest ping in the west.	1146	The fastest ping in the west.
1051
1052	=item L<AnyEvent::DBI>
1053
1054	Executes L<DBI> requests asynchronously in a proxy process.
1055
1056	=item L<AnyEvent::AIO>
1057
1058	Truly asynchronous I/O, should be in the toolbox of every event
1059	programmer. AnyEvent::AIO transparently fuses L<IO::AIO> and AnyEvent
1060	together.
1061
1062	=item L<AnyEvent::BDB>
1063
1064	Truly asynchronous Berkeley DB access. AnyEvent::BDB transparently fuses
1065	L<BDB> and AnyEvent together.
1066
1067	=item L<AnyEvent::GPSD>
1068
1069	A non-blocking interface to gpsd, a daemon delivering GPS information.
1070
1071	=item L<AnyEvent::IRC>
1072
1073	AnyEvent based IRC client module family (replacing the older Net::IRC3).
1074
1075	=item L<AnyEvent::XMPP>
1076
1077	AnyEvent based XMPP (Jabber protocol) module family (replacing the older
1078	Net::XMPP2>.
1079
1080	=item L<AnyEvent::IGS>
1081
1082	A non-blocking interface to the Internet Go Server protocol (used by
1083	L<App::IGS>).
1084
1085	=item L<Net::FCP>
1086
1087	AnyEvent-based implementation of the Freenet Client Protocol, birthplace
1088	of AnyEvent.
1089
1090	=item L<Event::ExecFlow>
1091
1092	High level API for event-based execution flow control.
1093		1147
1094	=item L<Coro>	1148	=item L<Coro>
1095		1149
1096	Has special support for AnyEvent via L<Coro::AnyEvent>.	1150	Has special support for AnyEvent via L<Coro::AnyEvent>.
1097		1151
…		…
1101		1155
1102	package AnyEvent;	1156	package AnyEvent;
1103		1157
1104	# basically a tuned-down version of common::sense	1158	# basically a tuned-down version of common::sense
1105	sub common_sense {	1159	sub common_sense {
1106	# no warnings	1160	# from common:.sense 3.3
1107	${^WARNING_BITS} ^= ${^WARNING_BITS};	1161	${^WARNING_BITS} ^= ${^WARNING_BITS} ^ "\x3c\x3f\x33\x00\x0f\xf3\x0f\xc0\xf0\xfc\x33\x00";
1108	# use strict vars subs	1162	# use strict vars subs - NO UTF-8, as Util.pm doesn't like this atm. (uts46data.pl)
1109	$^H |= 0x00000600;	1163	$^H |= 0x00000600;
1110	}	1164	}
1111		1165
1112	BEGIN { AnyEvent::common_sense }	1166	BEGIN { AnyEvent::common_sense }
1113		1167
1114	use Carp ();	1168	use Carp ();
1115		1169
1116	our $VERSION = 4.881;	1170	our $VERSION = '5.271';
1117	our $MODEL;	1171	our $MODEL;
1118		1172
1119	our $AUTOLOAD;	1173	our $AUTOLOAD;
1120	our @ISA;	1174	our @ISA;
1121		1175
1122	our @REGISTRY;	1176	our @REGISTRY;
1123		1177
1124	our $WIN32;
1125
1126	our $VERBOSE;	1178	our $VERBOSE;
1127		1179
1128	BEGIN {	1180	BEGIN {
1129	eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }";	1181	require "AnyEvent/constants.pl";
		1182
1130	eval "sub TAINT(){ " . (${^TAINT}*1) . " }";	1183	eval "sub TAINT (){" . (${^TAINT}*1) . "}";
1131		1184
1132	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}	1185	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}
1133	if ${^TAINT};	1186	if ${^TAINT};
1134		1187
1135	$VERBOSE = $ENV{PERL_ANYEVENT_VERBOSE}*1;	1188	$VERBOSE = $ENV{PERL_ANYEVENT_VERBOSE}*1;
…		…
1147	$ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";	1200	$ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";
1148	}	1201	}
1149		1202
1150	my @models = (	1203	my @models = (
1151	[EV:: => AnyEvent::Impl::EV:: , 1],	1204	[EV:: => AnyEvent::Impl::EV:: , 1],
1152	[Event:: => AnyEvent::Impl::Event::, 1],
1153	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl:: , 1],	1205	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl:: , 1],
1154	# everything below here will not (normally) be autoprobed	1206	# everything below here will not (normally) be autoprobed
1155	# as the pureperl backend should work everywhere	1207	# as the pureperl backend should work everywhere
1156	# and is usually faster	1208	# and is usually faster
		1209	[Event:: => AnyEvent::Impl::Event::, 1],
1157	[Glib:: => AnyEvent::Impl::Glib:: , 1], # becomes extremely slow with many watchers	1210	[Glib:: => AnyEvent::Impl::Glib:: , 1], # becomes extremely slow with many watchers
1158	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy	1211	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
1159	[Irssi:: => AnyEvent::Impl::Irssi::], # Irssi has a bogus "Event" package	1212	[Irssi:: => AnyEvent::Impl::Irssi::], # Irssi has a bogus "Event" package
1160	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles	1213	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
1161	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program	1214	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program
…		…
1164	[Prima:: => AnyEvent::Impl::POE::],	1217	[Prima:: => AnyEvent::Impl::POE::],
1165	# IO::Async is just too broken - we would need workarounds for its	1218	# IO::Async is just too broken - we would need workarounds for its
1166	# byzantine signal and broken child handling, among others.	1219	# byzantine signal and broken child handling, among others.
1167	# IO::Async is rather hard to detect, as it doesn't have any	1220	# IO::Async is rather hard to detect, as it doesn't have any
1168	# obvious default class.	1221	# obvious default class.
1169	# [0, IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program	1222	[IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program
1170	# [0, IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program	1223	[IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program
1171	# [0, IO::Async::Notifier:: => AnyEvent::Impl::IOAsync::], # requires special main program	1224	[IO::Async::Notifier:: => AnyEvent::Impl::IOAsync::], # requires special main program
		1225	[AnyEvent::Impl::IOAsync:: => AnyEvent::Impl::IOAsync::], # requires special main program
1172	);	1226	);
1173		1227
1174	our %method = map +($_ => 1),	1228	our %method = map +($_ => 1),
1175	qw(io timer time now now_update signal child idle condvar one_event DESTROY);	1229	qw(io timer time now now_update signal child idle condvar one_event DESTROY);
1176		1230
1177	our @post_detect;	1231	our @post_detect;
1178		1232
1179	sub post_detect(&) {	1233	sub post_detect(&) {
1180	my ($cb) = @_;	1234	my ($cb) = @_;
1181		1235
1182	if ($MODEL) {
1183	$cb->();
1184
1185	undef
1186	} else {
1187	push @post_detect, $cb;	1236	push @post_detect, $cb;
1188		1237
1189	defined wantarray	1238	defined wantarray
1190	? bless \$cb, "AnyEvent::Util::postdetect"	1239	? bless \$cb, "AnyEvent::Util::postdetect"
1191	: ()	1240	: ()
1192	}
1193	}	1241	}
1194		1242
1195	sub AnyEvent::Util::postdetect::DESTROY {	1243	sub AnyEvent::Util::postdetect::DESTROY {
1196	@post_detect = grep $_ != ${$_[0]}, @post_detect;	1244	@post_detect = grep $_ != ${$_[0]}, @post_detect;
1197	}	1245	}
1198		1246
1199	sub detect() {	1247	sub detect() {
		1248	# free some memory
		1249	*detect = sub () { $MODEL };
		1250
		1251	local $!; # for good measure
		1252	local $SIG{__DIE__};
		1253
		1254	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {
		1255	my $model = "AnyEvent::Impl::$1";
		1256	if (eval "require $model") {
		1257	$MODEL = $model;
		1258	warn "AnyEvent: loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.\n" if $VERBOSE >= 2;
		1259	} else {
		1260	warn "AnyEvent: unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@" if $VERBOSE;
		1261	}
		1262	}
		1263
		1264	# check for already loaded models
1200	unless ($MODEL) {	1265	unless ($MODEL) {
1201	local $SIG{__DIE__};	1266	for (@REGISTRY, @models) {
1202		1267	my ($package, $model) = @$_;
1203	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {	1268	if (${"$package\::VERSION"} > 0) {
1204	my $model = "AnyEvent::Impl::$1";
1205	if (eval "require $model") {	1269	if (eval "require $model") {
1206	$MODEL = $model;	1270	$MODEL = $model;
1207	warn "AnyEvent: loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.\n" if $VERBOSE >= 2;	1271	warn "AnyEvent: autodetected model '$model', using it.\n" if $VERBOSE >= 2;
1208	} else {	1272	last;
1209	warn "AnyEvent: unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@" if $VERBOSE;	1273	}
1210	}	1274	}
1211	}	1275	}
1212		1276
1213	# check for already loaded models
1214	unless ($MODEL) {	1277	unless ($MODEL) {
		1278	# try to autoload a model
1215	for (@REGISTRY, @models) {	1279	for (@REGISTRY, @models) {
1216	my ($package, $model) = @$_;	1280	my ($package, $model, $autoload) = @$_;
		1281	if (
		1282	$autoload
		1283	and eval "require $package"
1217	if (${"$package\::VERSION"} > 0) {	1284	and ${"$package\::VERSION"} > 0
1218	if (eval "require $model") {	1285	and eval "require $model"
		1286	) {
1219	$MODEL = $model;	1287	$MODEL = $model;
1220	warn "AnyEvent: autodetected model '$model', using it.\n" if $VERBOSE >= 2;	1288	warn "AnyEvent: autoloaded model '$model', using it.\n" if $VERBOSE >= 2;
1221	last;	1289	last;
1222	}
1223	}	1290	}
1224	}	1291	}
1225		1292
1226	unless ($MODEL) {
1227	# try to autoload a model
1228	for (@REGISTRY, @models) {
1229	my ($package, $model, $autoload) = @$_;
1230	if (
1231	$autoload
1232	and eval "require $package"
1233	and ${"$package\::VERSION"} > 0
1234	and eval "require $model"
1235	) {
1236	$MODEL = $model;
1237	warn "AnyEvent: autoloaded model '$model', using it.\n" if $VERBOSE >= 2;
1238	last;
1239	}
1240	}
1241
1242	$MODEL	1293	$MODEL
1243	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.\n";	1294	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.\n";
1244	}
1245	}	1295	}
1246
1247	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
1248
1249	unshift @ISA, $MODEL;
1250
1251	require AnyEvent::Strict if $ENV{PERL_ANYEVENT_STRICT};
1252
1253	(shift @post_detect)->() while @post_detect;
1254	}	1296	}
		1297
		1298	@models = (); # free probe data
		1299
		1300	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
		1301	unshift @ISA, $MODEL;
		1302
		1303	# now nuke some methods that are overriden by the backend.
		1304	# SUPER is not allowed.
		1305	for (qw(time signal child idle)) {
		1306	undef &{"AnyEvent::Base::$_"}
		1307	if defined &{"$MODEL\::$_"};
		1308	}
		1309
		1310	require AnyEvent::Strict if $ENV{PERL_ANYEVENT_STRICT};
		1311
		1312	(shift @post_detect)->() while @post_detect;
		1313
		1314	*post_detect = sub(&) {
		1315	shift->();
		1316
		1317	undef
		1318	};
1255		1319
1256	$MODEL	1320	$MODEL
1257	}	1321	}
1258		1322
1259	sub AUTOLOAD {	1323	sub AUTOLOAD {
1260	(my $func = $AUTOLOAD) =~ s/.*://;	1324	(my $func = $AUTOLOAD) =~ s/.*://;
1261		1325
1262	$method{$func}	1326	$method{$func}
1263	or Carp::croak "$func: not a valid method for AnyEvent objects";	1327	or Carp::croak "$func: not a valid AnyEvent class method";
1264		1328
1265	detect unless $MODEL;	1329	detect;
1266		1330
1267	my $class = shift;	1331	my $class = shift;
1268	$class->$func (@_);	1332	$class->$func (@_);
1269	}	1333	}
1270		1334
…		…
1283	# we assume CLOEXEC is already set by perl in all important cases	1347	# we assume CLOEXEC is already set by perl in all important cases
1284		1348
1285	($fh2, $rw)	1349	($fh2, $rw)
1286	}	1350	}
1287		1351
		1352	=head1 SIMPLIFIED AE API
		1353
		1354	Starting with version 5.0, AnyEvent officially supports a second, much
		1355	simpler, API that is designed to reduce the calling, typing and memory
		1356	overhead by using function call syntax and a fixed number of parameters.
		1357
		1358	See the L<AE> manpage for details.
		1359
		1360	=cut
		1361
		1362	package AE;
		1363
		1364	our $VERSION = $AnyEvent::VERSION;
		1365
		1366	# fall back to the main API by default - backends and AnyEvent::Base
		1367	# implementations can overwrite these.
		1368
		1369	sub io($$$) {
		1370	AnyEvent->io (fh => $_[0], poll => $_[1] ? "w" : "r", cb => $_[2])
		1371	}
		1372
		1373	sub timer($$$) {
		1374	AnyEvent->timer (after => $_[0], interval => $_[1], cb => $_[2])
		1375	}
		1376
		1377	sub signal($$) {
		1378	AnyEvent->signal (signal => $_[0], cb => $_[1])
		1379	}
		1380
		1381	sub child($$) {
		1382	AnyEvent->child (pid => $_[0], cb => $_[1])
		1383	}
		1384
		1385	sub idle($) {
		1386	AnyEvent->idle (cb => $_[0])
		1387	}
		1388
		1389	sub cv(;&) {
		1390	AnyEvent->condvar (@_ ? (cb => $_[0]) : ())
		1391	}
		1392
		1393	sub now() {
		1394	AnyEvent->now
		1395	}
		1396
		1397	sub now_update() {
		1398	AnyEvent->now_update
		1399	}
		1400
		1401	sub time() {
		1402	AnyEvent->time
		1403	}
		1404
1288	package AnyEvent::Base;	1405	package AnyEvent::Base;
1289		1406
1290	# default implementations for many methods	1407	# default implementations for many methods
1291		1408
1292	sub _time {	1409	sub time {
		1410	eval q{ # poor man's autoloading {}
1293	# probe for availability of Time::HiRes	1411	# probe for availability of Time::HiRes
1294	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {	1412	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {
1295	warn "AnyEvent: using Time::HiRes for sub-second timing accuracy.\n" if $VERBOSE >= 8;	1413	warn "AnyEvent: using Time::HiRes for sub-second timing accuracy.\n" if $VERBOSE >= 8;
1296	*_time = \&Time::HiRes::time;	1414	*AE::time = \&Time::HiRes::time;
1297	# if (eval "use POSIX (); (POSIX::times())...	1415	# if (eval "use POSIX (); (POSIX::times())...
1298	} else {	1416	} else {
1299	warn "AnyEvent: using built-in time(), WARNING, no sub-second resolution!\n" if $VERBOSE;	1417	warn "AnyEvent: using built-in time(), WARNING, no sub-second resolution!\n" if $VERBOSE;
1300	*_time = sub { time }; # epic fail	1418	*AE::time = sub (){ time }; # epic fail
		1419	}
		1420
		1421	*time = sub { AE::time }; # different prototypes
1301	}	1422	};
		1423	die if $@;
1302		1424
1303	&_time	1425	&time
1304	}	1426	}
1305		1427
1306	sub time { _time }	1428	*now = \&time;
1307	sub now { _time }	1429
1308	sub now_update { }	1430	sub now_update { }
1309		1431
1310	# default implementation for ->condvar	1432	# default implementation for ->condvar
1311		1433
1312	sub condvar {	1434	sub condvar {
		1435	eval q{ # poor man's autoloading {}
		1436	*condvar = sub {
1313	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"	1437	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"
		1438	};
		1439
		1440	*AE::cv = sub (;&) {
		1441	bless { @_ ? (_ae_cb => shift) : () }, "AnyEvent::CondVar"
		1442	};
		1443	};
		1444	die if $@;
		1445
		1446	&condvar
1314	}	1447	}
1315		1448
1316	# default implementation for ->signal	1449	# default implementation for ->signal
1317		1450
1318	our $HAVE_ASYNC_INTERRUPT;	1451	our $HAVE_ASYNC_INTERRUPT;
1319		1452
1320	sub _have_async_interrupt() {	1453	sub _have_async_interrupt() {
1321	$HAVE_ASYNC_INTERRUPT = 1*(!$ENV{PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT}	1454	$HAVE_ASYNC_INTERRUPT = 1*(!$ENV{PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT}
1322	&& eval "use Async::Interrupt 1.0 (); 1")	1455	&& eval "use Async::Interrupt 1.02 (); 1")
1323	unless defined $HAVE_ASYNC_INTERRUPT;	1456	unless defined $HAVE_ASYNC_INTERRUPT;
1324		1457
1325	$HAVE_ASYNC_INTERRUPT	1458	$HAVE_ASYNC_INTERRUPT
1326	}	1459	}
1327		1460
1328	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);	1461	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);
1329	our (%SIG_ASY, %SIG_ASY_W);	1462	our (%SIG_ASY, %SIG_ASY_W);
1330	our ($SIG_COUNT, $SIG_TW);	1463	our ($SIG_COUNT, $SIG_TW);
1331		1464
1332	sub _signal_exec {
1333	$HAVE_ASYNC_INTERRUPT
1334	? $SIGPIPE_R->drain
1335	: sysread $SIGPIPE_R, my $dummy, 9;
1336
1337	while (%SIG_EV) {
1338	for (keys %SIG_EV) {
1339	delete $SIG_EV{$_};
1340	$_->() for values %{ $SIG_CB{$_} || {} };
1341	}
1342	}
1343	}
1344
1345	# install a dummy wakeup watcher to reduce signal catching latency	1465	# install a dummy wakeup watcher to reduce signal catching latency
		1466	# used by Impls
1346	sub _sig_add() {	1467	sub _sig_add() {
1347	unless ($SIG_COUNT++) {	1468	unless ($SIG_COUNT++) {
1348	# try to align timer on a full-second boundary, if possible	1469	# try to align timer on a full-second boundary, if possible
1349	my $NOW = AnyEvent->now;	1470	my $NOW = AE::now;
1350		1471
1351	$SIG_TW = AnyEvent->timer (	1472	$SIG_TW = AE::timer
1352	after => $MAX_SIGNAL_LATENCY - ($NOW - int $NOW),	1473	$MAX_SIGNAL_LATENCY - ($NOW - int $NOW),
1353	interval => $MAX_SIGNAL_LATENCY,	1474	$MAX_SIGNAL_LATENCY,
1354	cb => sub { }, # just for the PERL_ASYNC_CHECK	1475	sub { } # just for the PERL_ASYNC_CHECK
1355	);	1476	;
1356	}	1477	}
1357	}	1478	}
1358		1479
1359	sub _sig_del {	1480	sub _sig_del {
1360	undef $SIG_TW	1481	undef $SIG_TW
1361	unless --$SIG_COUNT;	1482	unless --$SIG_COUNT;
1362	}	1483	}
1363		1484
1364	our $_sig_name_init; $_sig_name_init = sub {	1485	our $_sig_name_init; $_sig_name_init = sub {
1365	eval q{ # poor man's autoloading	1486	eval q{ # poor man's autoloading {}
1366	undef $_sig_name_init;	1487	undef $_sig_name_init;
1367		1488
1368	if (_have_async_interrupt) {	1489	if (_have_async_interrupt) {
1369	*sig2num = \&Async::Interrupt::sig2num;	1490	*sig2num = \&Async::Interrupt::sig2num;
1370	*sig2name = \&Async::Interrupt::sig2name;	1491	*sig2name = \&Async::Interrupt::sig2name;
…		…
1397	# probe for availability of Async::Interrupt	1518	# probe for availability of Async::Interrupt
1398	if (_have_async_interrupt) {	1519	if (_have_async_interrupt) {
1399	warn "AnyEvent: using Async::Interrupt for race-free signal handling.\n" if $VERBOSE >= 8;	1520	warn "AnyEvent: using Async::Interrupt for race-free signal handling.\n" if $VERBOSE >= 8;
1400		1521
1401	$SIGPIPE_R = new Async::Interrupt::EventPipe;	1522	$SIGPIPE_R = new Async::Interrupt::EventPipe;
1402	$SIG_IO = AnyEvent->io (fh => $SIGPIPE_R->fileno, poll => "r", cb => \&_signal_exec);	1523	$SIG_IO = AE::io $SIGPIPE_R->fileno, 0, \&_signal_exec;
1403		1524
1404	} else {	1525	} else {
1405	warn "AnyEvent: using emulated perl signal handling with latency timer.\n" if $VERBOSE >= 8;	1526	warn "AnyEvent: using emulated perl signal handling with latency timer.\n" if $VERBOSE >= 8;
1406
1407	require Fcntl;
1408		1527
1409	if (AnyEvent::WIN32) {	1528	if (AnyEvent::WIN32) {
1410	require AnyEvent::Util;	1529	require AnyEvent::Util;
1411		1530
1412	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();	1531	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
1413	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R, 1) if $SIGPIPE_R;	1532	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R, 1) if $SIGPIPE_R;
1414	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W, 1) if $SIGPIPE_W; # just in case	1533	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W, 1) if $SIGPIPE_W; # just in case
1415	} else {	1534	} else {
1416	pipe $SIGPIPE_R, $SIGPIPE_W;	1535	pipe $SIGPIPE_R, $SIGPIPE_W;
1417	fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R;	1536	fcntl $SIGPIPE_R, AnyEvent::F_SETFL, AnyEvent::O_NONBLOCK if $SIGPIPE_R;
1418	fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case	1537	fcntl $SIGPIPE_W, AnyEvent::F_SETFL, AnyEvent::O_NONBLOCK if $SIGPIPE_W; # just in case
1419		1538
1420	# not strictly required, as $^F is normally 2, but let's make sure...	1539	# not strictly required, as $^F is normally 2, but let's make sure...
1421	fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;	1540	fcntl $SIGPIPE_R, AnyEvent::F_SETFD, AnyEvent::FD_CLOEXEC;
1422	fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;	1541	fcntl $SIGPIPE_W, AnyEvent::F_SETFD, AnyEvent::FD_CLOEXEC;
1423	}	1542	}
1424		1543
1425	$SIGPIPE_R	1544	$SIGPIPE_R
1426	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";	1545	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";
1427		1546
1428	$SIG_IO = AnyEvent->io (fh => $SIGPIPE_R, poll => "r", cb => \&_signal_exec);	1547	$SIG_IO = AE::io $SIGPIPE_R, 0, \&_signal_exec;
1429	}	1548	}
1430		1549
1431	*signal = sub {	1550	*signal = $HAVE_ASYNC_INTERRUPT
		1551	? sub {
1432	my (undef, %arg) = @_;	1552	my (undef, %arg) = @_;
1433		1553
1434	my $signal = uc $arg{signal}
1435	or Carp::croak "required option 'signal' is missing";
1436
1437	if ($HAVE_ASYNC_INTERRUPT) {
1438	# async::interrupt	1554	# async::interrupt
1439
1440	$signal = sig2num $signal;	1555	my $signal = sig2num $arg{signal};
1441	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};	1556	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
1442		1557
1443	$SIG_ASY{$signal} ||= new Async::Interrupt	1558	$SIG_ASY{$signal} ||= new Async::Interrupt
1444	cb => sub { undef $SIG_EV{$signal} },	1559	cb => sub { undef $SIG_EV{$signal} },
1445	signal => $signal,	1560	signal => $signal,
1446	pipe => [$SIGPIPE_R->filenos],	1561	pipe => [$SIGPIPE_R->filenos],
1447	pipe_autodrain => 0,	1562	pipe_autodrain => 0,
1448	;	1563	;
1449		1564
1450	} else {	1565	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
		1566	}
		1567	: sub {
		1568	my (undef, %arg) = @_;
		1569
1451	# pure perl	1570	# pure perl
1452
1453	# AE::Util has been loaded in signal
1454	$signal = sig2name $signal;	1571	my $signal = sig2name $arg{signal};
1455	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};	1572	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
1456		1573
1457	$SIG{$signal} ||= sub {	1574	$SIG{$signal} ||= sub {
1458	local $!;	1575	local $!;
1459	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;	1576	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;
1460	undef $SIG_EV{$signal};	1577	undef $SIG_EV{$signal};
1461	};	1578	};
1462		1579
1463	# can't do signal processing without introducing races in pure perl,	1580	# can't do signal processing without introducing races in pure perl,
1464	# so limit the signal latency.	1581	# so limit the signal latency.
1465	_sig_add;	1582	_sig_add;
1466	}
1467		1583
1468	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"	1584	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
		1585	}
1469	};	1586	;
1470		1587
1471	*AnyEvent::Base::signal::DESTROY = sub {	1588	*AnyEvent::Base::signal::DESTROY = sub {
1472	my ($signal, $cb) = @{$_[0]};	1589	my ($signal, $cb) = @{$_[0]};
1473		1590
1474	_sig_del;	1591	_sig_del;
…		…
1481	# print weird messages, or just unconditionally exit	1598	# print weird messages, or just unconditionally exit
1482	# instead of getting the default action.	1599	# instead of getting the default action.
1483	undef $SIG{$signal}	1600	undef $SIG{$signal}
1484	unless keys %{ $SIG_CB{$signal} };	1601	unless keys %{ $SIG_CB{$signal} };
1485	};	1602	};
		1603
		1604	*_signal_exec = sub {
		1605	$HAVE_ASYNC_INTERRUPT
		1606	? $SIGPIPE_R->drain
		1607	: sysread $SIGPIPE_R, (my $dummy), 9;
		1608
		1609	while (%SIG_EV) {
		1610	for (keys %SIG_EV) {
		1611	delete $SIG_EV{$_};
		1612	$_->() for values %{ $SIG_CB{$_} || {} };
		1613	}
		1614	}
		1615	};
1486	};	1616	};
1487	die if $@;	1617	die if $@;
		1618
1488	&signal	1619	&signal
1489	}	1620	}
1490		1621
1491	# default implementation for ->child	1622	# default implementation for ->child
1492		1623
1493	our %PID_CB;	1624	our %PID_CB;
1494	our $CHLD_W;	1625	our $CHLD_W;
1495	our $CHLD_DELAY_W;	1626	our $CHLD_DELAY_W;
1496	our $WNOHANG;	1627	our $WNOHANG;
1497		1628
		1629	# used by many Impl's
1498	sub _emit_childstatus($$) {	1630	sub _emit_childstatus($$) {
1499	my (undef, $rpid, $rstatus) = @_;	1631	my (undef, $rpid, $rstatus) = @_;
1500		1632
1501	$_->($rpid, $rstatus)	1633	$_->($rpid, $rstatus)
1502	for values %{ $PID_CB{$rpid} || {} },	1634	for values %{ $PID_CB{$rpid} || {} },
1503	values %{ $PID_CB{0} || {} };	1635	values %{ $PID_CB{0} || {} };
1504	}	1636	}
1505		1637
1506	sub _sigchld {
1507	my $pid;
1508
1509	AnyEvent->_emit_childstatus ($pid, $?)
1510	while ($pid = waitpid -1, $WNOHANG) > 0;
1511	}
1512
1513	sub child {	1638	sub child {
		1639	eval q{ # poor man's autoloading {}
		1640	*_sigchld = sub {
		1641	my $pid;
		1642
		1643	AnyEvent->_emit_childstatus ($pid, $?)
		1644	while ($pid = waitpid -1, $WNOHANG) > 0;
		1645	};
		1646
		1647	*child = sub {
1514	my (undef, %arg) = @_;	1648	my (undef, %arg) = @_;
1515		1649
1516	defined (my $pid = $arg{pid} + 0)	1650	defined (my $pid = $arg{pid} + 0)
1517	or Carp::croak "required option 'pid' is missing";	1651	or Carp::croak "required option 'pid' is missing";
1518		1652
1519	$PID_CB{$pid}{$arg{cb}} = $arg{cb};	1653	$PID_CB{$pid}{$arg{cb}} = $arg{cb};
1520		1654
1521	# WNOHANG is almost cetrainly 1 everywhere	1655	# WNOHANG is almost cetrainly 1 everywhere
1522	$WNOHANG ||= $^O =~ /^(?:openbsd|netbsd|linux|freebsd|cygwin|MSWin32)$/	1656	$WNOHANG ||= $^O =~ /^(?:openbsd|netbsd|linux|freebsd|cygwin|MSWin32)$/
1523	? 1	1657	? 1
1524	: eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1;	1658	: eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1;
1525		1659
1526	unless ($CHLD_W) {	1660	unless ($CHLD_W) {
1527	$CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld);	1661	$CHLD_W = AE::signal CHLD => \&_sigchld;
1528	# child could be a zombie already, so make at least one round	1662	# child could be a zombie already, so make at least one round
1529	&_sigchld;	1663	&_sigchld;
1530	}	1664	}
1531		1665
1532	bless [$pid, $arg{cb}], "AnyEvent::Base::child"	1666	bless [$pid, $arg{cb}], "AnyEvent::Base::child"
1533	}	1667	};
1534		1668
1535	sub AnyEvent::Base::child::DESTROY {	1669	*AnyEvent::Base::child::DESTROY = sub {
1536	my ($pid, $cb) = @{$_[0]};	1670	my ($pid, $cb) = @{$_[0]};
1537		1671
1538	delete $PID_CB{$pid}{$cb};	1672	delete $PID_CB{$pid}{$cb};
1539	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };	1673	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };
1540		1674
1541	undef $CHLD_W unless keys %PID_CB;	1675	undef $CHLD_W unless keys %PID_CB;
		1676	};
		1677	};
		1678	die if $@;
		1679
		1680	&child
1542	}	1681	}
1543		1682
1544	# idle emulation is done by simply using a timer, regardless	1683	# idle emulation is done by simply using a timer, regardless
1545	# of whether the process is idle or not, and not letting	1684	# of whether the process is idle or not, and not letting
1546	# the callback use more than 50% of the time.	1685	# the callback use more than 50% of the time.
1547	sub idle {	1686	sub idle {
		1687	eval q{ # poor man's autoloading {}
		1688	*idle = sub {
1548	my (undef, %arg) = @_;	1689	my (undef, %arg) = @_;
1549		1690
1550	my ($cb, $w, $rcb) = $arg{cb};	1691	my ($cb, $w, $rcb) = $arg{cb};
1551		1692
1552	$rcb = sub {	1693	$rcb = sub {
1553	if ($cb) {	1694	if ($cb) {
1554	$w = _time;	1695	$w = _time;
1555	&$cb;	1696	&$cb;
1556	$w = _time - $w;	1697	$w = _time - $w;
1557		1698
1558	# never use more then 50% of the time for the idle watcher,	1699	# never use more then 50% of the time for the idle watcher,
1559	# within some limits	1700	# within some limits
1560	$w = 0.0001 if $w < 0.0001;	1701	$w = 0.0001 if $w < 0.0001;
1561	$w = 5 if $w > 5;	1702	$w = 5 if $w > 5;
1562		1703
1563	$w = AnyEvent->timer (after => $w, cb => $rcb);	1704	$w = AE::timer $w, 0, $rcb;
1564	} else {	1705	} else {
1565	# clean up...	1706	# clean up...
1566	undef $w;	1707	undef $w;
1567	undef $rcb;	1708	undef $rcb;
		1709	}
		1710	};
		1711
		1712	$w = AE::timer 0.05, 0, $rcb;
		1713
		1714	bless \\$cb, "AnyEvent::Base::idle"
1568	}	1715	};
		1716
		1717	*AnyEvent::Base::idle::DESTROY = sub {
		1718	undef $${$_[0]};
		1719	};
1569	};	1720	};
		1721	die if $@;
1570		1722
1571	$w = AnyEvent->timer (after => 0.05, cb => $rcb);	1723	&idle
1572
1573	bless \\$cb, "AnyEvent::Base::idle"
1574	}
1575
1576	sub AnyEvent::Base::idle::DESTROY {
1577	undef $${$_[0]};
1578	}	1724	}
1579		1725
1580	package AnyEvent::CondVar;	1726	package AnyEvent::CondVar;
1581		1727
1582	our @ISA = AnyEvent::CondVar::Base::;	1728	our @ISA = AnyEvent::CondVar::Base::;
		1729
		1730	# only to be used for subclassing
		1731	sub new {
		1732	my $class = shift;
		1733	bless AnyEvent->condvar (@_), $class
		1734	}
1583		1735
1584	package AnyEvent::CondVar::Base;	1736	package AnyEvent::CondVar::Base;
1585		1737
1586	#use overload	1738	#use overload
1587	# '&{}' => sub { my $self = shift; sub { $self->send (@_) } },	1739	# '&{}' => sub { my $self = shift; sub { $self->send (@_) } },
…		…
1630	Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak};	1782	Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak};
1631	wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0]	1783	wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0]
1632	}	1784	}
1633		1785
1634	sub cb {	1786	sub cb {
1635	$_[0]{_ae_cb} = $_[1] if @_ > 1;	1787	my $cv = shift;
		1788
		1789	@_
		1790	and $cv->{_ae_cb} = shift
		1791	and $cv->{_ae_sent}
		1792	and (delete $cv->{_ae_cb})->($cv);
		1793
1636	$_[0]{_ae_cb}	1794	$cv->{_ae_cb}
1637	}	1795	}
1638		1796
1639	sub begin {	1797	sub begin {
1640	++$_[0]{_ae_counter};	1798	++$_[0]{_ae_counter};
1641	$_[0]{_ae_end_cb} = $_[1] if @_ > 1;	1799	$_[0]{_ae_end_cb} = $_[1] if @_ > 1;
…		…
1647	}	1805	}
1648		1806
1649	# undocumented/compatibility with pre-3.4	1807	# undocumented/compatibility with pre-3.4
1650	*broadcast = \&send;	1808	*broadcast = \&send;
1651	*wait = \&_wait;	1809	*wait = \&_wait;
1652
1653	#############################################################################
1654	# "new" API, currently only emulation of it
1655	#############################################################################
1656
1657	package AE;
1658
1659	sub io($$$) {
1660	AnyEvent->io (fh => $_[0], poll => $_[1] ? "w" : "r", cb => $_[2])
1661	}
1662
1663	sub timer($$$) {
1664	AnyEvent->timer (after => $_[0], interval => $_[1], cb => $_[2]);
1665	}
1666
1667	sub signal($$) {
1668	AnyEvent->signal (signal => $_[0], cb => $_[1]);
1669	}
1670
1671	sub child($$) {
1672	AnyEvent->child (pid => $_[0], cb => $_[1]);
1673	}
1674
1675	sub idle($) {
1676	AnyEvent->idle (cb => $_[0]);
1677	}
1678
1679	sub cv() {
1680	AnyEvent->condvar
1681	}
1682
1683	sub now() {
1684	AnyEvent->now
1685	}
1686
1687	sub now_update() {
1688	AnyEvent->now_update
1689	}
1690
1691	sub time() {
1692	AnyEvent->time
1693	}
1694		1810
1695	=head1 ERROR AND EXCEPTION HANDLING	1811	=head1 ERROR AND EXCEPTION HANDLING
1696		1812
1697	In general, AnyEvent does not do any error handling - it relies on the	1813	In general, AnyEvent does not do any error handling - it relies on the
1698	caller to do that if required. The L<AnyEvent::Strict> module (see also	1814	caller to do that if required. The L<AnyEvent::Strict> module (see also
…		…
1745	check the arguments passed to most method calls. If it finds any problems,	1861	check the arguments passed to most method calls. If it finds any problems,
1746	it will croak.	1862	it will croak.
1747		1863
1748	In other words, enables "strict" mode.	1864	In other words, enables "strict" mode.
1749		1865
1750	Unlike C<use strict> (or it's modern cousin, C<< use L<common::sense>	1866	Unlike C<use strict> (or its modern cousin, C<< use L<common::sense>
1751	>>, it is definitely recommended to keep it off in production. Keeping	1867	>>, it is definitely recommended to keep it off in production. Keeping
1752	C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs	1868	C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs
1753	can be very useful, however.	1869	can be very useful, however.
1754		1870
1755	=item C<PERL_ANYEVENT_MODEL>	1871	=item C<PERL_ANYEVENT_MODEL>
…		…
1892	warn "read: $input\n"; # output what has been read	2008	warn "read: $input\n"; # output what has been read
1893	$cv->send if $input =~ /^q/i; # quit program if /^q/i	2009	$cv->send if $input =~ /^q/i; # quit program if /^q/i
1894	},	2010	},
1895	);	2011	);
1896		2012
1897	my $time_watcher; # can only be used once
1898
1899	sub new_timer {
1900	$timer = AnyEvent->timer (after => 1, cb => sub {	2013	my $time_watcher = AnyEvent->timer (after => 1, interval => 1, cb => sub {
1901	warn "timeout\n"; # print 'timeout' about every second	2014	warn "timeout\n"; # print 'timeout' at most every second
1902	&new_timer; # and restart the time
1903	});	2015	});
1904	}
1905
1906	new_timer; # create first timer
1907		2016
1908	$cv->recv; # wait until user enters /^q/i	2017	$cv->recv; # wait until user enters /^q/i
1909		2018
1910	=head1 REAL-WORLD EXAMPLE	2019	=head1 REAL-WORLD EXAMPLE
1911		2020
…		…
1984		2093
1985	The actual code goes further and collects all errors (C<die>s, exceptions)	2094	The actual code goes further and collects all errors (C<die>s, exceptions)
1986	that occurred during request processing. The C<result> method detects	2095	that occurred during request processing. The C<result> method detects
1987	whether an exception as thrown (it is stored inside the $txn object)	2096	whether an exception as thrown (it is stored inside the $txn object)
1988	and just throws the exception, which means connection errors and other	2097	and just throws the exception, which means connection errors and other
1989	problems get reported tot he code that tries to use the result, not in a	2098	problems get reported to the code that tries to use the result, not in a
1990	random callback.	2099	random callback.
1991		2100
1992	All of this enables the following usage styles:	2101	All of this enables the following usage styles:
1993		2102
1994	1. Blocking:	2103	1. Blocking:
…		…
2042	through AnyEvent. The benchmark creates a lot of timers (with a zero	2151	through AnyEvent. The benchmark creates a lot of timers (with a zero
2043	timeout) and I/O watchers (watching STDOUT, a pty, to become writable,	2152	timeout) and I/O watchers (watching STDOUT, a pty, to become writable,
2044	which it is), lets them fire exactly once and destroys them again.	2153	which it is), lets them fire exactly once and destroys them again.
2045		2154
2046	Source code for this benchmark is found as F<eg/bench> in the AnyEvent	2155	Source code for this benchmark is found as F<eg/bench> in the AnyEvent
2047	distribution.	2156	distribution. It uses the L<AE> interface, which makes a real difference
		2157	for the EV and Perl backends only.
2048		2158
2049	=head3 Explanation of the columns	2159	=head3 Explanation of the columns
2050		2160
2051	I<watcher> is the number of event watchers created/destroyed. Since	2161	I<watcher> is the number of event watchers created/destroyed. Since
2052	different event models feature vastly different performances, each event	2162	different event models feature vastly different performances, each event
…		…
2073	watcher.	2183	watcher.
2074		2184
2075	=head3 Results	2185	=head3 Results
2076		2186
2077	name watchers bytes create invoke destroy comment	2187	name watchers bytes create invoke destroy comment
2078	EV/EV 400000 224 0.47 0.35 0.27 EV native interface	2188	EV/EV 100000 223 0.47 0.43 0.27 EV native interface
2079	EV/Any 100000 224 2.88 0.34 0.27 EV + AnyEvent watchers	2189	EV/Any 100000 223 0.48 0.42 0.26 EV + AnyEvent watchers
2080	CoroEV/Any 100000 224 2.85 0.35 0.28 coroutines + Coro::Signal	2190	Coro::EV/Any 100000 223 0.47 0.42 0.26 coroutines + Coro::Signal
2081	Perl/Any 100000 452 4.13 0.73 0.95 pure perl implementation	2191	Perl/Any 100000 431 2.70 0.74 0.92 pure perl implementation
2082	Event/Event 16000 517 32.20 31.80 0.81 Event native interface	2192	Event/Event 16000 516 31.16 31.84 0.82 Event native interface
2083	Event/Any 16000 590 35.85 31.55 1.06 Event + AnyEvent watchers	2193	Event/Any 16000 1203 42.61 34.79 1.80 Event + AnyEvent watchers
2084	IOAsync/Any 16000 989 38.10 32.77 11.13 via IO::Async::Loop::IO_Poll	2194	IOAsync/Any 16000 1911 41.92 27.45 16.81 via IO::Async::Loop::IO_Poll
2085	IOAsync/Any 16000 990 37.59 29.50 10.61 via IO::Async::Loop::Epoll	2195	IOAsync/Any 16000 1726 40.69 26.37 15.25 via IO::Async::Loop::Epoll
2086	Glib/Any 16000 1357 102.33 12.31 51.00 quadratic behaviour	2196	Glib/Any 16000 1118 89.00 12.57 51.17 quadratic behaviour
2087	Tk/Any 2000 1860 27.20 66.31 14.00 SEGV with >> 2000 watchers	2197	Tk/Any 2000 1346 20.96 10.75 8.00 SEGV with >> 2000 watchers
2088	POE/Event 2000 6328 109.99 751.67 14.02 via POE::Loop::Event	2198	POE/Any 2000 6951 108.97 795.32 14.24 via POE::Loop::Event
2089	POE/Select 2000 6027 94.54 809.13 579.80 via POE::Loop::Select	2199	POE/Any 2000 6648 94.79 774.40 575.51 via POE::Loop::Select
2090		2200
2091	=head3 Discussion	2201	=head3 Discussion
2092		2202
2093	The benchmark does I<not> measure scalability of the event loop very	2203	The benchmark does I<not> measure scalability of the event loop very
2094	well. For example, a select-based event loop (such as the pure perl one)	2204	well. For example, a select-based event loop (such as the pure perl one)
…		…
2106	benchmark machine, handling an event takes roughly 1600 CPU cycles with	2216	benchmark machine, handling an event takes roughly 1600 CPU cycles with
2107	EV, 3100 CPU cycles with AnyEvent's pure perl loop and almost 3000000 CPU	2217	EV, 3100 CPU cycles with AnyEvent's pure perl loop and almost 3000000 CPU
2108	cycles with POE.	2218	cycles with POE.
2109		2219
2110	C<EV> is the sole leader regarding speed and memory use, which are both	2220	C<EV> is the sole leader regarding speed and memory use, which are both
2111	maximal/minimal, respectively. Even when going through AnyEvent, it uses	2221	maximal/minimal, respectively. When using the L<AE> API there is zero
		2222	overhead (when going through the AnyEvent API create is about 5-6 times
		2223	slower, with other times being equal, so still uses far less memory than
2112	far less memory than any other event loop and is still faster than Event	2224	any other event loop and is still faster than Event natively).
2113	natively.
2114		2225
2115	The pure perl implementation is hit in a few sweet spots (both the	2226	The pure perl implementation is hit in a few sweet spots (both the
2116	constant timeout and the use of a single fd hit optimisations in the perl	2227	constant timeout and the use of a single fd hit optimisations in the perl
2117	interpreter and the backend itself). Nevertheless this shows that it	2228	interpreter and the backend itself). Nevertheless this shows that it
2118	adds very little overhead in itself. Like any select-based backend its	2229	adds very little overhead in itself. Like any select-based backend its
…		…
2192	In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100	2303	In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100
2193	(1%) are active. This mirrors the activity of large servers with many	2304	(1%) are active. This mirrors the activity of large servers with many
2194	connections, most of which are idle at any one point in time.	2305	connections, most of which are idle at any one point in time.
2195		2306
2196	Source code for this benchmark is found as F<eg/bench2> in the AnyEvent	2307	Source code for this benchmark is found as F<eg/bench2> in the AnyEvent
2197	distribution.	2308	distribution. It uses the L<AE> interface, which makes a real difference
		2309	for the EV and Perl backends only.
2198		2310
2199	=head3 Explanation of the columns	2311	=head3 Explanation of the columns
2200		2312
2201	I<sockets> is the number of sockets, and twice the number of "servers" (as	2313	I<sockets> is the number of sockets, and twice the number of "servers" (as
2202	each server has a read and write socket end).	2314	each server has a read and write socket end).
…		…
2210	a new one that moves the timeout into the future.	2322	a new one that moves the timeout into the future.
2211		2323
2212	=head3 Results	2324	=head3 Results
2213		2325
2214	name sockets create request	2326	name sockets create request
2215	EV 20000 69.01 11.16	2327	EV 20000 62.66 7.99
2216	Perl 20000 73.32 35.87	2328	Perl 20000 68.32 32.64
2217	IOAsync 20000 157.00 98.14 epoll	2329	IOAsync 20000 174.06 101.15 epoll
2218	IOAsync 20000 159.31 616.06 poll	2330	IOAsync 20000 174.67 610.84 poll
2219	Event 20000 212.62 257.32	2331	Event 20000 202.69 242.91
2220	Glib 20000 651.16 1896.30	2332	Glib 20000 557.01 1689.52
2221	POE 20000 349.67 12317.24 uses POE::Loop::Event	2333	POE 20000 341.54 12086.32 uses POE::Loop::Event
2222		2334
2223	=head3 Discussion	2335	=head3 Discussion
2224		2336
2225	This benchmark I<does> measure scalability and overall performance of the	2337	This benchmark I<does> measure scalability and overall performance of the
2226	particular event loop.	2338	particular event loop.
…		…
2352	As you can see, the AnyEvent + EV combination even beats the	2464	As you can see, the AnyEvent + EV combination even beats the
2353	hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl	2465	hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl
2354	backend easily beats IO::Lambda and POE.	2466	backend easily beats IO::Lambda and POE.
2355		2467
2356	And even the 100% non-blocking version written using the high-level (and	2468	And even the 100% non-blocking version written using the high-level (and
2357	slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda by a	2469	slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda
2358	large margin, even though it does all of DNS, tcp-connect and socket I/O	2470	higher level ("unoptimised") abstractions by a large margin, even though
2359	in a non-blocking way.	2471	it does all of DNS, tcp-connect and socket I/O in a non-blocking way.
2360		2472
2361	The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and	2473	The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and
2362	F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are	2474	F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are
2363	part of the IO::lambda distribution and were used without any changes.	2475	part of the IO::Lambda distribution and were used without any changes.
2364		2476
2365		2477
2366	=head1 SIGNALS	2478	=head1 SIGNALS
2367		2479
2368	AnyEvent currently installs handlers for these signals:	2480	AnyEvent currently installs handlers for these signals:
…		…
2405	unless defined $SIG{PIPE};	2517	unless defined $SIG{PIPE};
2406		2518
2407	=head1 RECOMMENDED/OPTIONAL MODULES	2519	=head1 RECOMMENDED/OPTIONAL MODULES
2408		2520
2409	One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and	2521	One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and
2410	it's built-in modules) are required to use it.	2522	its built-in modules) are required to use it.
2411		2523
2412	That does not mean that AnyEvent won't take advantage of some additional	2524	That does not mean that AnyEvent won't take advantage of some additional
2413	modules if they are installed.	2525	modules if they are installed.
2414		2526
2415	This section epxlains which additional modules will be used, and how they	2527	This section explains which additional modules will be used, and how they
2416	affect AnyEvent's operetion.	2528	affect AnyEvent's operation.
2417		2529
2418	=over 4	2530	=over 4
2419		2531
2420	=item L<Async::Interrupt>	2532	=item L<Async::Interrupt>
2421		2533
…		…
2426	catch the signals) with some delay (default is 10 seconds, look for	2538	catch the signals) with some delay (default is 10 seconds, look for
2427	C<$AnyEvent::MAX_SIGNAL_LATENCY>).	2539	C<$AnyEvent::MAX_SIGNAL_LATENCY>).
2428		2540
2429	If this module is available, then it will be used to implement signal	2541	If this module is available, then it will be used to implement signal
2430	catching, which means that signals will not be delayed, and the event loop	2542	catching, which means that signals will not be delayed, and the event loop
2431	will not be interrupted regularly, which is more efficient (And good for	2543	will not be interrupted regularly, which is more efficient (and good for
2432	battery life on laptops).	2544	battery life on laptops).
2433		2545
2434	This affects not just the pure-perl event loop, but also other event loops	2546	This affects not just the pure-perl event loop, but also other event loops
2435	that have no signal handling on their own (e.g. Glib, Tk, Qt).	2547	that have no signal handling on their own (e.g. Glib, Tk, Qt).
2436		2548
…		…
2448	automatic timer adjustments even when no monotonic clock is available,	2560	automatic timer adjustments even when no monotonic clock is available,
2449	can take avdantage of advanced kernel interfaces such as C<epoll> and	2561	can take avdantage of advanced kernel interfaces such as C<epoll> and
2450	C<kqueue>, and is the fastest backend I<by far>. You can even embed	2562	C<kqueue>, and is the fastest backend I<by far>. You can even embed
2451	L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>).	2563	L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>).
2452		2564
		2565	If you only use backends that rely on another event loop (e.g. C<Tk>),
		2566	then this module will do nothing for you.
		2567
2453	=item L<Guard>	2568	=item L<Guard>
2454		2569
2455	The guard module, when used, will be used to implement	2570	The guard module, when used, will be used to implement
2456	C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a	2571	C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a
2457	lot less memory), but otherwise doesn't affect guard operation much. It is	2572	lot less memory), but otherwise doesn't affect guard operation much. It is
2458	purely used for performance.	2573	purely used for performance.
2459		2574
2460	=item L<JSON> and L<JSON::XS>	2575	=item L<JSON> and L<JSON::XS>
2461		2576
2462	This module is required when you want to read or write JSON data via	2577	One of these modules is required when you want to read or write JSON data
2463	L<AnyEvent::Handle>. It is also written in pure-perl, but can take	2578	via L<AnyEvent::Handle>. L<JSON> is also written in pure-perl, but can take
2464	advantage of the ultra-high-speed L<JSON::XS> module when it is installed.	2579	advantage of the ultra-high-speed L<JSON::XS> module when it is installed.
2465
2466	In fact, L<AnyEvent::Handle> will use L<JSON::XS> by default if it is
2467	installed.
2468		2580
2469	=item L<Net::SSLeay>	2581	=item L<Net::SSLeay>
2470		2582
2471	Implementing TLS/SSL in Perl is certainly interesting, but not very	2583	Implementing TLS/SSL in Perl is certainly interesting, but not very
2472	worthwhile: If this module is installed, then L<AnyEvent::Handle> (with	2584	worthwhile: If this module is installed, then L<AnyEvent::Handle> (with
2473	the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL.	2585	the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL.
2474		2586
2475	=item L<Time::HiRes>	2587	=item L<Time::HiRes>
2476		2588
2477	This module is part of perl since release 5.008. It will be used when the	2589	This module is part of perl since release 5.008. It will be used when the
2478	chosen event library does not come with a timing source on it's own. The	2590	chosen event library does not come with a timing source of its own. The
2479	pure-perl event loop (L<AnyEvent::Impl::Perl>) will additionally use it to	2591	pure-perl event loop (L<AnyEvent::Impl::Perl>) will additionally use it to
2480	try to use a monotonic clock for timing stability.	2592	try to use a monotonic clock for timing stability.
2481		2593
2482	=back	2594	=back
2483		2595
2484		2596
2485	=head1 FORK	2597	=head1 FORK
2486		2598
2487	Most event libraries are not fork-safe. The ones who are usually are	2599	Most event libraries are not fork-safe. The ones who are usually are
2488	because they rely on inefficient but fork-safe C<select> or C<poll>	2600	because they rely on inefficient but fork-safe C<select> or C<poll> calls
2489	calls. Only L<EV> is fully fork-aware.	2601	- higher performance APIs such as BSD's kqueue or the dreaded Linux epoll
		2602	are usually badly thought-out hacks that are incompatible with fork in
		2603	one way or another. Only L<EV> is fully fork-aware and ensures that you
		2604	continue event-processing in both parent and child (or both, if you know
		2605	what you are doing).
		2606
		2607	This means that, in general, you cannot fork and do event processing in
		2608	the child if the event library was initialised before the fork (which
		2609	usually happens when the first AnyEvent watcher is created, or the library
		2610	is loaded).
2490		2611
2491	If you have to fork, you must either do so I<before> creating your first	2612	If you have to fork, you must either do so I<before> creating your first
2492	watcher OR you must not use AnyEvent at all in the child OR you must do	2613	watcher OR you must not use AnyEvent at all in the child OR you must do
2493	something completely out of the scope of AnyEvent.	2614	something completely out of the scope of AnyEvent.
		2615
		2616	The problem of doing event processing in the parent I<and> the child
		2617	is much more complicated: even for backends that I<are> fork-aware or
		2618	fork-safe, their behaviour is not usually what you want: fork clones all
		2619	watchers, that means all timers, I/O watchers etc. are active in both
		2620	parent and child, which is almost never what you want. USing C<exec>
		2621	to start worker children from some kind of manage rprocess is usually
		2622	preferred, because it is much easier and cleaner, at the expense of having
		2623	to have another binary.
2494		2624
2495		2625
2496	=head1 SECURITY CONSIDERATIONS	2626	=head1 SECURITY CONSIDERATIONS
2497		2627
2498	AnyEvent can be forced to load any event model via	2628	AnyEvent can be forced to load any event model via

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