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Revision 1.243 by root, Fri Jul 17 23:12:20 2009 UTC vs.
Revision 1.323 by root, Thu May 20 21:22:20 2010 UTC

1	=head1 NAME	1	=head1 NAME
2		2
3	AnyEvent - provide framework for multiple event loops	3	AnyEvent - the DBI of event loop programming
4		4
5	EV, Event, Glib, Tk, Perl, Event::Lib, Qt and POE are various supported	5	EV, Event, Glib, Tk, Perl, Event::Lib, Irssi, rxvt-unicode, IO::Async, Qt
6	event loops.	6	and POE are various supported event loops/environments.
7		7
8	=head1 SYNOPSIS	8	=head1 SYNOPSIS
9		9
10	use AnyEvent;	10	use AnyEvent;
11		11
		12	# if you prefer function calls, look at the AE manpage for
		13	# an alternative API.
		14
12	# file descriptor readable	15	# file handle or descriptor readable
13	my $w = AnyEvent->io (fh => $fh, poll => "r", cb => sub { ... });	16	my $w = AnyEvent->io (fh => $fh, poll => "r", cb => sub { ... });
14		17
15	# one-shot or repeating timers	18	# one-shot or repeating timers
16	my $w = AnyEvent->timer (after => $seconds, cb => sub { ... });	19	my $w = AnyEvent->timer (after => $seconds, cb => sub { ... });
17	my $w = AnyEvent->timer (after => $seconds, interval => $seconds, cb => ...	20	my $w = AnyEvent->timer (after => $seconds, interval => $seconds, cb => ...
…		…
40	=head1 INTRODUCTION/TUTORIAL	43	=head1 INTRODUCTION/TUTORIAL
41		44
42	This manpage is mainly a reference manual. If you are interested	45	This manpage is mainly a reference manual. If you are interested
43	in a tutorial or some gentle introduction, have a look at the	46	in a tutorial or some gentle introduction, have a look at the
44	L<AnyEvent::Intro> manpage.	47	L<AnyEvent::Intro> manpage.
		48
		49	=head1 SUPPORT
		50
		51	There is a mailinglist for discussing all things AnyEvent, and an IRC
		52	channel, too.
		53
		54	See the AnyEvent project page at the B<Schmorpforge Ta-Sa Software
		55	Repository>, at L<http://anyevent.schmorp.de>, for more info.
45		56
46	=head1 WHY YOU SHOULD USE THIS MODULE (OR NOT)	57	=head1 WHY YOU SHOULD USE THIS MODULE (OR NOT)
47		58
48	Glib, POE, IO::Async, Event... CPAN offers event models by the dozen	59	Glib, POE, IO::Async, Event... CPAN offers event models by the dozen
49	nowadays. So what is different about AnyEvent?	60	nowadays. So what is different about AnyEvent?
…		…
173	my variables are only visible after the statement in which they are	184	my variables are only visible after the statement in which they are
174	declared.	185	declared.
175		186
176	=head2 I/O WATCHERS	187	=head2 I/O WATCHERS
177		188
		189	$w = AnyEvent->io (
		190	fh => <filehandle_or_fileno>,
		191	poll => <"r" or "w">,
		192	cb => <callback>,
		193	);
		194
178	You can create an I/O watcher by calling the C<< AnyEvent->io >> method	195	You can create an I/O watcher by calling the C<< AnyEvent->io >> method
179	with the following mandatory key-value pairs as arguments:	196	with the following mandatory key-value pairs as arguments:
180		197
181	C<fh> is the Perl I<file handle> (or a naked file descriptor) to watch	198	C<fh> is the Perl I<file handle> (or a naked file descriptor) to watch
182	for events (AnyEvent might or might not keep a reference to this file	199	for events (AnyEvent might or might not keep a reference to this file
…		…
211	undef $w;	228	undef $w;
212	});	229	});
213		230
214	=head2 TIME WATCHERS	231	=head2 TIME WATCHERS
215		232
		233	$w = AnyEvent->timer (after => <seconds>, cb => <callback>);
		234
		235	$w = AnyEvent->timer (
		236	after => <fractional_seconds>,
		237	interval => <fractional_seconds>,
		238	cb => <callback>,
		239	);
		240
216	You can create a time watcher by calling the C<< AnyEvent->timer >>	241	You can create a time watcher by calling the C<< AnyEvent->timer >>
217	method with the following mandatory arguments:	242	method with the following mandatory arguments:
218		243
219	C<after> specifies after how many seconds (fractional values are	244	C<after> specifies after how many seconds (fractional values are
220	supported) the callback should be invoked. C<cb> is the callback to invoke	245	supported) the callback should be invoked. C<cb> is the callback to invoke
…		…
341	might affect timers and time-outs.	366	might affect timers and time-outs.
342		367
343	When this is the case, you can call this method, which will update the	368	When this is the case, you can call this method, which will update the
344	event loop's idea of "current time".	369	event loop's idea of "current time".
345		370
		371	A typical example would be a script in a web server (e.g. C<mod_perl>) -
		372	when mod_perl executes the script, then the event loop will have the wrong
		373	idea about the "current time" (being potentially far in the past, when the
		374	script ran the last time). In that case you should arrange a call to C<<
		375	AnyEvent->now_update >> each time the web server process wakes up again
		376	(e.g. at the start of your script, or in a handler).
		377
346	Note that updating the time I<might> cause some events to be handled.	378	Note that updating the time I<might> cause some events to be handled.
347		379
348	=back	380	=back
349		381
350	=head2 SIGNAL WATCHERS	382	=head2 SIGNAL WATCHERS
		383
		384	$w = AnyEvent->signal (signal => <uppercase_signal_name>, cb => <callback>);
351		385
352	You can watch for signals using a signal watcher, C<signal> is the signal	386	You can watch for signals using a signal watcher, C<signal> is the signal
353	I<name> in uppercase and without any C<SIG> prefix, C<cb> is the Perl	387	I<name> in uppercase and without any C<SIG> prefix, C<cb> is the Perl
354	callback to be invoked whenever a signal occurs.	388	callback to be invoked whenever a signal occurs.
355		389
…		…
368		402
369	This watcher might use C<%SIG> (depending on the event loop used),	403	This watcher might use C<%SIG> (depending on the event loop used),
370	so programs overwriting those signals directly will likely not work	404	so programs overwriting those signals directly will likely not work
371	correctly.	405	correctly.
372		406
		407	Example: exit on SIGINT
		408
		409	my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });
		410
		411	=head3 Restart Behaviour
		412
		413	While restart behaviour is up to the event loop implementation, most will
		414	not restart syscalls (that includes L<Async::Interrupt> and AnyEvent's
		415	pure perl implementation).
		416
		417	=head3 Safe/Unsafe Signals
		418
		419	Perl signals can be either "safe" (synchronous to opcode handling) or
		420	"unsafe" (asynchronous) - the former might get delayed indefinitely, the
		421	latter might corrupt your memory.
		422
		423	AnyEvent signal handlers are, in addition, synchronous to the event loop,
		424	i.e. they will not interrupt your running perl program but will only be
		425	called as part of the normal event handling (just like timer, I/O etc.
		426	callbacks, too).
		427
		428	=head3 Signal Races, Delays and Workarounds
		429
373	Also note that many event loops (e.g. Glib, Tk, Qt, IO::Async) do not	430	Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support attaching
374	support attaching callbacks to signals, which is a pity, as you cannot do	431	callbacks to signals in a generic way, which is a pity, as you cannot
375	race-free signal handling in perl. AnyEvent will try to do it's best, but	432	do race-free signal handling in perl, requiring C libraries for
		433	this. AnyEvent will try to do it's best, which means in some cases,
376	in some cases, signals will be delayed. The maximum time a signal might	434	signals will be delayed. The maximum time a signal might be delayed is
377	be delayed is specified in C<$AnyEvent::MAX_SIGNAL_LATENCY> (default: 10	435	specified in C<$AnyEvent::MAX_SIGNAL_LATENCY> (default: 10 seconds). This
378	seconds). This variable can be changed only before the first signal	436	variable can be changed only before the first signal watcher is created,
379	watcher is created, and should be left alone otherwise. Higher values	437	and should be left alone otherwise. This variable determines how often
		438	AnyEvent polls for signals (in case a wake-up was missed). Higher values
380	will cause fewer spurious wake-ups, which is better for power and CPU	439	will cause fewer spurious wake-ups, which is better for power and CPU
		440	saving.
		441
381	saving. All these problems can be avoided by installing the optional	442	All these problems can be avoided by installing the optional
382	L<Async::Interrupt> module.	443	L<Async::Interrupt> module, which works with most event loops. It will not
383		444	work with inherently broken event loops such as L<Event> or L<Event::Lib>
384	Example: exit on SIGINT	445	(and not with L<POE> currently, as POE does it's own workaround with
385		446	one-second latency). For those, you just have to suffer the delays.
386	my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });
387		447
388	=head2 CHILD PROCESS WATCHERS	448	=head2 CHILD PROCESS WATCHERS
389		449
		450	$w = AnyEvent->child (pid => <process id>, cb => <callback>);
		451
390	You can also watch on a child process exit and catch its exit status.	452	You can also watch on a child process exit and catch its exit status.
391		453
392	The child process is specified by the C<pid> argument (if set to C<0>, it	454	The child process is specified by the C<pid> argument (one some backends,
393	watches for any child process exit). The watcher will triggered only when	455	using C<0> watches for any child process exit, on others this will
394	the child process has finished and an exit status is available, not on	456	croak). The watcher will be triggered only when the child process has
395	any trace events (stopped/continued).	457	finished and an exit status is available, not on any trace events
		458	(stopped/continued).
396		459
397	The callback will be called with the pid and exit status (as returned by	460	The callback will be called with the pid and exit status (as returned by
398	waitpid), so unlike other watcher types, you I<can> rely on child watcher	461	waitpid), so unlike other watcher types, you I<can> rely on child watcher
399	callback arguments.	462	callback arguments.
400		463
…		…
441	# do something else, then wait for process exit	504	# do something else, then wait for process exit
442	$done->recv;	505	$done->recv;
443		506
444	=head2 IDLE WATCHERS	507	=head2 IDLE WATCHERS
445		508
446	Sometimes there is a need to do something, but it is not so important	509	$w = AnyEvent->idle (cb => <callback>);
447	to do it instantly, but only when there is nothing better to do. This
448	"nothing better to do" is usually defined to be "no other events need
449	attention by the event loop".
450		510
451	Idle watchers ideally get invoked when the event loop has nothing	511	Repeatedly invoke the callback after the process becomes idle, until
452	better to do, just before it would block the process to wait for new	512	either the watcher is destroyed or new events have been detected.
453	events. Instead of blocking, the idle watcher is invoked.
454		513
455	Most event loops unfortunately do not really support idle watchers (only	514	Idle watchers are useful when there is a need to do something, but it
		515	is not so important (or wise) to do it instantly. The callback will be
		516	invoked only when there is "nothing better to do", which is usually
		517	defined as "all outstanding events have been handled and no new events
		518	have been detected". That means that idle watchers ideally get invoked
		519	when the event loop has just polled for new events but none have been
		520	detected. Instead of blocking to wait for more events, the idle watchers
		521	will be invoked.
		522
		523	Unfortunately, most event loops do not really support idle watchers (only
456	EV, Event and Glib do it in a usable fashion) - for the rest, AnyEvent	524	EV, Event and Glib do it in a usable fashion) - for the rest, AnyEvent
457	will simply call the callback "from time to time".	525	will simply call the callback "from time to time".
458		526
459	Example: read lines from STDIN, but only process them when the	527	Example: read lines from STDIN, but only process them when the
460	program is otherwise idle:	528	program is otherwise idle:
…		…
476	});	544	});
477	});	545	});
478		546
479	=head2 CONDITION VARIABLES	547	=head2 CONDITION VARIABLES
480		548
		549	$cv = AnyEvent->condvar;
		550
		551	$cv->send (<list>);
		552	my @res = $cv->recv;
		553
481	If you are familiar with some event loops you will know that all of them	554	If you are familiar with some event loops you will know that all of them
482	require you to run some blocking "loop", "run" or similar function that	555	require you to run some blocking "loop", "run" or similar function that
483	will actively watch for new events and call your callbacks.	556	will actively watch for new events and call your callbacks.
484		557
485	AnyEvent is slightly different: it expects somebody else to run the event	558	AnyEvent is slightly different: it expects somebody else to run the event
…		…
504	Condition variables are similar to callbacks, except that you can	577	Condition variables are similar to callbacks, except that you can
505	optionally wait for them. They can also be called merge points - points	578	optionally wait for them. They can also be called merge points - points
506	in time where multiple outstanding events have been processed. And yet	579	in time where multiple outstanding events have been processed. And yet
507	another way to call them is transactions - each condition variable can be	580	another way to call them is transactions - each condition variable can be
508	used to represent a transaction, which finishes at some point and delivers	581	used to represent a transaction, which finishes at some point and delivers
509	a result.	582	a result. And yet some people know them as "futures" - a promise to
		583	compute/deliver something that you can wait for.
510		584
511	Condition variables are very useful to signal that something has finished,	585	Condition variables are very useful to signal that something has finished,
512	for example, if you write a module that does asynchronous http requests,	586	for example, if you write a module that does asynchronous http requests,
513	then a condition variable would be the ideal candidate to signal the	587	then a condition variable would be the ideal candidate to signal the
514	availability of results. The user can either act when the callback is	588	availability of results. The user can either act when the callback is
…		…
535	eventually calls C<< -> send >>, and the "consumer side", which waits	609	eventually calls C<< -> send >>, and the "consumer side", which waits
536	for the send to occur.	610	for the send to occur.
537		611
538	Example: wait for a timer.	612	Example: wait for a timer.
539		613
540	# wait till the result is ready	614	# condition: "wait till the timer is fired"
541	my $result_ready = AnyEvent->condvar;	615	my $timer_fired = AnyEvent->condvar;
542		616
543	# do something such as adding a timer	617	# create the timer - we could wait for, say
544	# or socket watcher the calls $result_ready->send	618	# a handle becomign ready, or even an
545	# when the "result" is ready.	619	# AnyEvent::HTTP request to finish, but
546	# in this case, we simply use a timer:	620	# in this case, we simply use a timer:
547	my $w = AnyEvent->timer (	621	my $w = AnyEvent->timer (
548	after => 1,	622	after => 1,
549	cb => sub { $result_ready->send },	623	cb => sub { $timer_fired->send },
550	);	624	);
551		625
552	# this "blocks" (while handling events) till the callback	626	# this "blocks" (while handling events) till the callback
553	# calls -<send	627	# calls ->send
554	$result_ready->recv;	628	$timer_fired->recv;
555		629
556	Example: wait for a timer, but take advantage of the fact that condition	630	Example: wait for a timer, but take advantage of the fact that condition
557	variables are also callable directly.	631	variables are also callable directly.
558		632
559	my $done = AnyEvent->condvar;	633	my $done = AnyEvent->condvar;
…		…
622	one. For example, a function that pings many hosts in parallel might want	696	one. For example, a function that pings many hosts in parallel might want
623	to use a condition variable for the whole process.	697	to use a condition variable for the whole process.
624		698
625	Every call to C<< ->begin >> will increment a counter, and every call to	699	Every call to C<< ->begin >> will increment a counter, and every call to
626	C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end	700	C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end
627	>>, the (last) callback passed to C<begin> will be executed. That callback	701	>>, the (last) callback passed to C<begin> will be executed, passing the
628	is I<supposed> to call C<< ->send >>, but that is not required. If no	702	condvar as first argument. That callback is I<supposed> to call C<< ->send
629	callback was set, C<send> will be called without any arguments.	703	>>, but that is not required. If no group callback was set, C<send> will
		704	be called without any arguments.
630		705
631	You can think of C<< $cv->send >> giving you an OR condition (one call	706	You can think of C<< $cv->send >> giving you an OR condition (one call
632	sends), while C<< $cv->begin >> and C<< $cv->end >> giving you an AND	707	sends), while C<< $cv->begin >> and C<< $cv->end >> giving you an AND
633	condition (all C<begin> calls must be C<end>'ed before the condvar sends).	708	condition (all C<begin> calls must be C<end>'ed before the condvar sends).
634		709
…		…
661	begung can potentially be zero:	736	begung can potentially be zero:
662		737
663	my $cv = AnyEvent->condvar;	738	my $cv = AnyEvent->condvar;
664		739
665	my %result;	740	my %result;
666	$cv->begin (sub { $cv->send (\%result) });	741	$cv->begin (sub { shift->send (\%result) });
667		742
668	for my $host (@list_of_hosts) {	743	for my $host (@list_of_hosts) {
669	$cv->begin;	744	$cv->begin;
670	ping_host_then_call_callback $host, sub {	745	ping_host_then_call_callback $host, sub {
671	$result{$host} = ...;	746	$result{$host} = ...;
…		…
746	=item $cb = $cv->cb ($cb->($cv))	821	=item $cb = $cv->cb ($cb->($cv))
747		822
748	This is a mutator function that returns the callback set and optionally	823	This is a mutator function that returns the callback set and optionally
749	replaces it before doing so.	824	replaces it before doing so.
750		825
751	The callback will be called when the condition becomes "true", i.e. when	826	The callback will be called when the condition becomes (or already was)
752	C<send> or C<croak> are called, with the only argument being the condition	827	"true", i.e. when C<send> or C<croak> are called (or were called), with
753	variable itself. Calling C<recv> inside the callback or at any later time	828	the only argument being the condition variable itself. Calling C<recv>
754	is guaranteed not to block.	829	inside the callback or at any later time is guaranteed not to block.
755		830
756	=back	831	=back
757		832
758	=head1 SUPPORTED EVENT LOOPS/BACKENDS	833	=head1 SUPPORTED EVENT LOOPS/BACKENDS
759		834
…		…
762	=over 4	837	=over 4
763		838
764	=item Backends that are autoprobed when no other event loop can be found.	839	=item Backends that are autoprobed when no other event loop can be found.
765		840
766	EV is the preferred backend when no other event loop seems to be in	841	EV is the preferred backend when no other event loop seems to be in
767	use. If EV is not installed, then AnyEvent will try Event, and, failing	842	use. If EV is not installed, then AnyEvent will fall back to its own
768	that, will fall back to its own pure-perl implementation, which is	843	pure-perl implementation, which is available everywhere as it comes with
769	available everywhere as it comes with AnyEvent itself.	844	AnyEvent itself.
770		845
771	AnyEvent::Impl::EV based on EV (interface to libev, best choice).	846	AnyEvent::Impl::EV based on EV (interface to libev, best choice).
772	AnyEvent::Impl::Event based on Event, very stable, few glitches.
773	AnyEvent::Impl::Perl pure-perl implementation, fast and portable.	847	AnyEvent::Impl::Perl pure-perl implementation, fast and portable.
774		848
775	=item Backends that are transparently being picked up when they are used.	849	=item Backends that are transparently being picked up when they are used.
776		850
777	These will be used when they are currently loaded when the first watcher	851	These will be used when they are currently loaded when the first watcher
778	is created, in which case it is assumed that the application is using	852	is created, in which case it is assumed that the application is using
779	them. This means that AnyEvent will automatically pick the right backend	853	them. This means that AnyEvent will automatically pick the right backend
780	when the main program loads an event module before anything starts to	854	when the main program loads an event module before anything starts to
781	create watchers. Nothing special needs to be done by the main program.	855	create watchers. Nothing special needs to be done by the main program.
782		856
		857	AnyEvent::Impl::Event based on Event, very stable, few glitches.
783	AnyEvent::Impl::Glib based on Glib, slow but very stable.	858	AnyEvent::Impl::Glib based on Glib, slow but very stable.
784	AnyEvent::Impl::Tk based on Tk, very broken.	859	AnyEvent::Impl::Tk based on Tk, very broken.
785	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.	860	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
786	AnyEvent::Impl::POE based on POE, very slow, some limitations.	861	AnyEvent::Impl::POE based on POE, very slow, some limitations.
		862	AnyEvent::Impl::Irssi used when running within irssi.
787		863
788	=item Backends with special needs.	864	=item Backends with special needs.
789		865
790	Qt requires the Qt::Application to be instantiated first, but will	866	Qt requires the Qt::Application to be instantiated first, but will
791	otherwise be picked up automatically. As long as the main program	867	otherwise be picked up automatically. As long as the main program
…		…
865	event module detection too early, for example, L<AnyEvent::AIO> creates	941	event module detection too early, for example, L<AnyEvent::AIO> creates
866	and installs the global L<IO::AIO> watcher in a C<post_detect> block to	942	and installs the global L<IO::AIO> watcher in a C<post_detect> block to
867	avoid autodetecting the event module at load time.	943	avoid autodetecting the event module at load time.
868		944
869	If called in scalar or list context, then it creates and returns an object	945	If called in scalar or list context, then it creates and returns an object
870	that automatically removes the callback again when it is destroyed. See	946	that automatically removes the callback again when it is destroyed (or
		947	C<undef> when the hook was immediately executed). See L<AnyEvent::AIO> for
871	L<Coro::BDB> for a case where this is useful.	948	a case where this is useful.
		949
		950	Example: Create a watcher for the IO::AIO module and store it in
		951	C<$WATCHER>. Only do so after the event loop is initialised, though.
		952
		953	our WATCHER;
		954
		955	my $guard = AnyEvent::post_detect {
		956	$WATCHER = AnyEvent->io (fh => IO::AIO::poll_fileno, poll => 'r', cb => \&IO::AIO::poll_cb);
		957	};
		958
		959	# the ||= is important in case post_detect immediately runs the block,
		960	# as to not clobber the newly-created watcher. assigning both watcher and
		961	# post_detect guard to the same variable has the advantage of users being
		962	# able to just C<undef $WATCHER> if the watcher causes them grief.
		963
		964	$WATCHER ||= $guard;
872		965
873	=item @AnyEvent::post_detect	966	=item @AnyEvent::post_detect
874		967
875	If there are any code references in this array (you can C<push> to it	968	If there are any code references in this array (you can C<push> to it
876	before or after loading AnyEvent), then they will called directly after	969	before or after loading AnyEvent), then they will called directly after
…		…
879	You should check C<$AnyEvent::MODEL> before adding to this array, though:	972	You should check C<$AnyEvent::MODEL> before adding to this array, though:
880	if it is defined then the event loop has already been detected, and the	973	if it is defined then the event loop has already been detected, and the
881	array will be ignored.	974	array will be ignored.
882		975
883	Best use C<AnyEvent::post_detect { BLOCK }> when your application allows	976	Best use C<AnyEvent::post_detect { BLOCK }> when your application allows
884	it,as it takes care of these details.	977	it, as it takes care of these details.
885		978
886	This variable is mainly useful for modules that can do something useful	979	This variable is mainly useful for modules that can do something useful
887	when AnyEvent is used and thus want to know when it is initialised, but do	980	when AnyEvent is used and thus want to know when it is initialised, but do
888	not need to even load it by default. This array provides the means to hook	981	not need to even load it by default. This array provides the means to hook
889	into AnyEvent passively, without loading it.	982	into AnyEvent passively, without loading it.
		983
		984	Example: To load Coro::AnyEvent whenever Coro and AnyEvent are used
		985	together, you could put this into Coro (this is the actual code used by
		986	Coro to accomplish this):
		987
		988	if (defined $AnyEvent::MODEL) {
		989	# AnyEvent already initialised, so load Coro::AnyEvent
		990	require Coro::AnyEvent;
		991	} else {
		992	# AnyEvent not yet initialised, so make sure to load Coro::AnyEvent
		993	# as soon as it is
		994	push @AnyEvent::post_detect, sub { require Coro::AnyEvent };
		995	}
890		996
891	=back	997	=back
892		998
893	=head1 WHAT TO DO IN A MODULE	999	=head1 WHAT TO DO IN A MODULE
894		1000
…		…
976		1082
977	=item L<AnyEvent::DNS>	1083	=item L<AnyEvent::DNS>
978		1084
979	Provides rich asynchronous DNS resolver capabilities.	1085	Provides rich asynchronous DNS resolver capabilities.
980		1086
		1087	=item L<AnyEvent::HTTP>, L<AnyEvent::IRC>, L<AnyEvent::XMPP>, L<AnyEvent::GPSD>, L<AnyEvent::IGS>, L<AnyEvent::FCP>
		1088
		1089	Implement event-based interfaces to the protocols of the same name (for
		1090	the curious, IGS is the International Go Server and FCP is the Freenet
		1091	Client Protocol).
		1092
		1093	=item L<AnyEvent::Handle::UDP>
		1094
		1095	Here be danger!
		1096
		1097	As Pauli would put it, "Not only is it not right, it's not even wrong!" -
		1098	there are so many things wrong with AnyEvent::Handle::UDP, most notably
		1099	it's use of a stream-based API with a protocol that isn't streamable, that
		1100	the only way to improve it is to delete it.
		1101
		1102	It features data corruption (but typically only under load) and general
		1103	confusion. On top, the author is not only clueless about UDP but also
		1104	fact-resistant - some gems of his understanding: "connect doesn't work
		1105	with UDP", "UDP packets are not IP packets", "UDP only has datagrams, not
		1106	packets", "I don't need to implement proper error checking as UDP doesn't
		1107	support error checking" and so on - he doesn't even understand what's
		1108	wrong with his module when it is explained to him.
		1109
981	=item L<AnyEvent::HTTP>	1110	=item L<AnyEvent::DBI>
982		1111
983	A simple-to-use HTTP library that is capable of making a lot of concurrent	1112	Executes L<DBI> requests asynchronously in a proxy process for you,
984	HTTP requests.	1113	notifying you in an event-bnased way when the operation is finished.
		1114
		1115	=item L<AnyEvent::AIO>
		1116
		1117	Truly asynchronous (as opposed to non-blocking) I/O, should be in the
		1118	toolbox of every event programmer. AnyEvent::AIO transparently fuses
		1119	L<IO::AIO> and AnyEvent together, giving AnyEvent access to event-based
		1120	file I/O, and much more.
985		1121
986	=item L<AnyEvent::HTTPD>	1122	=item L<AnyEvent::HTTPD>
987		1123
988	Provides a simple web application server framework.	1124	A simple embedded webserver.
989		1125
990	=item L<AnyEvent::FastPing>	1126	=item L<AnyEvent::FastPing>
991		1127
992	The fastest ping in the west.	1128	The fastest ping in the west.
993
994	=item L<AnyEvent::DBI>
995
996	Executes L<DBI> requests asynchronously in a proxy process.
997
998	=item L<AnyEvent::AIO>
999
1000	Truly asynchronous I/O, should be in the toolbox of every event
1001	programmer. AnyEvent::AIO transparently fuses L<IO::AIO> and AnyEvent
1002	together.
1003
1004	=item L<AnyEvent::BDB>
1005
1006	Truly asynchronous Berkeley DB access. AnyEvent::BDB transparently fuses
1007	L<BDB> and AnyEvent together.
1008
1009	=item L<AnyEvent::GPSD>
1010
1011	A non-blocking interface to gpsd, a daemon delivering GPS information.
1012
1013	=item L<AnyEvent::IRC>
1014
1015	AnyEvent based IRC client module family (replacing the older Net::IRC3).
1016
1017	=item L<AnyEvent::XMPP>
1018
1019	AnyEvent based XMPP (Jabber protocol) module family (replacing the older
1020	Net::XMPP2>.
1021
1022	=item L<AnyEvent::IGS>
1023
1024	A non-blocking interface to the Internet Go Server protocol (used by
1025	L<App::IGS>).
1026
1027	=item L<Net::FCP>
1028
1029	AnyEvent-based implementation of the Freenet Client Protocol, birthplace
1030	of AnyEvent.
1031
1032	=item L<Event::ExecFlow>
1033
1034	High level API for event-based execution flow control.
1035		1129
1036	=item L<Coro>	1130	=item L<Coro>
1037		1131
1038	Has special support for AnyEvent via L<Coro::AnyEvent>.	1132	Has special support for AnyEvent via L<Coro::AnyEvent>.
1039		1133
…		…
1043		1137
1044	package AnyEvent;	1138	package AnyEvent;
1045		1139
1046	# basically a tuned-down version of common::sense	1140	# basically a tuned-down version of common::sense
1047	sub common_sense {	1141	sub common_sense {
1048	# no warnings	1142	# from common:.sense 1.0
1049	${^WARNING_BITS} ^= ${^WARNING_BITS};	1143	${^WARNING_BITS} = "\xfc\x3f\x33\x00\x0f\xf3\xcf\xc0\xf3\xfc\x33\x00";
1050	# use strict vars subs	1144	# use strict vars subs - NO UTF-8, as Util.pm doesn't like this atm. (uts46data.pl)
1051	$^H |= 0x00000600;	1145	$^H |= 0x00000600;
1052	}	1146	}
1053		1147
1054	BEGIN { AnyEvent::common_sense }	1148	BEGIN { AnyEvent::common_sense }
1055		1149
1056	use Carp ();	1150	use Carp ();
1057		1151
1058	our $VERSION = 4.83;	1152	our $VERSION = '5.261';
1059	our $MODEL;	1153	our $MODEL;
1060		1154
1061	our $AUTOLOAD;	1155	our $AUTOLOAD;
1062	our @ISA;	1156	our @ISA;
1063		1157
1064	our @REGISTRY;	1158	our @REGISTRY;
1065		1159
1066	our $WIN32;
1067
1068	our $VERBOSE;	1160	our $VERBOSE;
1069		1161
1070	BEGIN {	1162	BEGIN {
1071	eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }";	1163	require "AnyEvent/constants.pl";
		1164
1072	eval "sub TAINT(){ " . (${^TAINT}*1) . " }";	1165	eval "sub TAINT (){" . (${^TAINT}*1) . "}";
1073		1166
1074	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}	1167	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}
1075	if ${^TAINT};	1168	if ${^TAINT};
1076		1169
1077	$VERBOSE = $ENV{PERL_ANYEVENT_VERBOSE}*1;	1170	$VERBOSE = $ENV{PERL_ANYEVENT_VERBOSE}*1;
…		…
1088	for reverse split /\s*,\s*/,	1181	for reverse split /\s*,\s*/,
1089	$ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";	1182	$ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";
1090	}	1183	}
1091		1184
1092	my @models = (	1185	my @models = (
1093	[EV:: => AnyEvent::Impl::EV::],	1186	[EV:: => AnyEvent::Impl::EV:: , 1],
1094	[Event:: => AnyEvent::Impl::Event::],
1095	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::],	1187	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl:: , 1],
1096	# everything below here will not be autoprobed	1188	# everything below here will not (normally) be autoprobed
1097	# as the pureperl backend should work everywhere	1189	# as the pureperl backend should work everywhere
1098	# and is usually faster	1190	# and is usually faster
		1191	[Event:: => AnyEvent::Impl::Event::, 1],
1099	[Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers	1192	[Glib:: => AnyEvent::Impl::Glib:: , 1], # becomes extremely slow with many watchers
1100	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy	1193	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
		1194	[Irssi:: => AnyEvent::Impl::Irssi::], # Irssi has a bogus "Event" package
1101	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles	1195	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
1102	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program	1196	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program
1103	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza	1197	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
1104	[Wx:: => AnyEvent::Impl::POE::],	1198	[Wx:: => AnyEvent::Impl::POE::],
1105	[Prima:: => AnyEvent::Impl::POE::],	1199	[Prima:: => AnyEvent::Impl::POE::],
1106	# IO::Async is just too broken - we would need workarounds for its	1200	# IO::Async is just too broken - we would need workarounds for its
1107	# byzantine signal and broken child handling, among others.	1201	# byzantine signal and broken child handling, among others.
1108	# IO::Async is rather hard to detect, as it doesn't have any	1202	# IO::Async is rather hard to detect, as it doesn't have any
1109	# obvious default class.	1203	# obvious default class.
1110	# [IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program	1204	[IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program
1111	# [IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program	1205	[IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program
1112	# [IO::Async::Notifier:: => AnyEvent::Impl::IOAsync::], # requires special main program	1206	[IO::Async::Notifier:: => AnyEvent::Impl::IOAsync::], # requires special main program
		1207	[AnyEvent::Impl::IOAsync:: => AnyEvent::Impl::IOAsync::], # requires special main program
1113	);	1208	);
1114		1209
1115	our %method = map +($_ => 1),	1210	our %method = map +($_ => 1),
1116	qw(io timer time now now_update signal child idle condvar one_event DESTROY);	1211	qw(io timer time now now_update signal child idle condvar one_event DESTROY);
1117		1212
1118	our @post_detect;	1213	our @post_detect;
1119		1214
1120	sub post_detect(&) {	1215	sub post_detect(&) {
1121	my ($cb) = @_;	1216	my ($cb) = @_;
1122		1217
1123	if ($MODEL) {
1124	$cb->();
1125
1126	1
1127	} else {
1128	push @post_detect, $cb;	1218	push @post_detect, $cb;
1129		1219
1130	defined wantarray	1220	defined wantarray
1131	? bless \$cb, "AnyEvent::Util::postdetect"	1221	? bless \$cb, "AnyEvent::Util::postdetect"
1132	: ()	1222	: ()
1133	}
1134	}	1223	}
1135		1224
1136	sub AnyEvent::Util::postdetect::DESTROY {	1225	sub AnyEvent::Util::postdetect::DESTROY {
1137	@post_detect = grep $_ != ${$_[0]}, @post_detect;	1226	@post_detect = grep $_ != ${$_[0]}, @post_detect;
1138	}	1227	}
1139		1228
1140	sub detect() {	1229	sub detect() {
		1230	# free some memory
		1231	*detect = sub () { $MODEL };
		1232
		1233	local $!; # for good measure
		1234	local $SIG{__DIE__};
		1235
		1236	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {
		1237	my $model = "AnyEvent::Impl::$1";
		1238	if (eval "require $model") {
		1239	$MODEL = $model;
		1240	warn "AnyEvent: loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.\n" if $VERBOSE >= 2;
		1241	} else {
		1242	warn "AnyEvent: unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@" if $VERBOSE;
		1243	}
		1244	}
		1245
		1246	# check for already loaded models
1141	unless ($MODEL) {	1247	unless ($MODEL) {
1142	local $SIG{__DIE__};	1248	for (@REGISTRY, @models) {
1143		1249	my ($package, $model) = @$_;
1144	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {	1250	if (${"$package\::VERSION"} > 0) {
1145	my $model = "AnyEvent::Impl::$1";
1146	if (eval "require $model") {	1251	if (eval "require $model") {
1147	$MODEL = $model;	1252	$MODEL = $model;
1148	warn "AnyEvent: loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.\n" if $VERBOSE >= 2;	1253	warn "AnyEvent: autodetected model '$model', using it.\n" if $VERBOSE >= 2;
1149	} else {	1254	last;
1150	warn "AnyEvent: unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@" if $VERBOSE;	1255	}
1151	}	1256	}
1152	}	1257	}
1153		1258
1154	# check for already loaded models
1155	unless ($MODEL) {	1259	unless ($MODEL) {
		1260	# try to autoload a model
1156	for (@REGISTRY, @models) {	1261	for (@REGISTRY, @models) {
1157	my ($package, $model) = @$_;	1262	my ($package, $model, $autoload) = @$_;
		1263	if (
		1264	$autoload
		1265	and eval "require $package"
1158	if (${"$package\::VERSION"} > 0) {	1266	and ${"$package\::VERSION"} > 0
1159	if (eval "require $model") {	1267	and eval "require $model"
		1268	) {
1160	$MODEL = $model;	1269	$MODEL = $model;
1161	warn "AnyEvent: autodetected model '$model', using it.\n" if $VERBOSE >= 2;	1270	warn "AnyEvent: autoloaded model '$model', using it.\n" if $VERBOSE >= 2;
1162	last;	1271	last;
1163	}
1164	}	1272	}
1165	}	1273	}
1166		1274
1167	unless ($MODEL) {
1168	# try to load a model
1169
1170	for (@REGISTRY, @models) {
1171	my ($package, $model) = @$_;
1172	if (eval "require $package"
1173	and ${"$package\::VERSION"} > 0
1174	and eval "require $model") {
1175	$MODEL = $model;
1176	warn "AnyEvent: autoprobed model '$model', using it.\n" if $VERBOSE >= 2;
1177	last;
1178	}
1179	}
1180
1181	$MODEL	1275	$MODEL
1182	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.\n";	1276	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.\n";
1183	}
1184	}	1277	}
1185
1186	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
1187
1188	unshift @ISA, $MODEL;
1189
1190	require AnyEvent::Strict if $ENV{PERL_ANYEVENT_STRICT};
1191
1192	(shift @post_detect)->() while @post_detect;
1193	}	1278	}
		1279
		1280	@models = (); # free probe data
		1281
		1282	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
		1283	unshift @ISA, $MODEL;
		1284
		1285	# now nuke some methods that are overriden by the backend.
		1286	# SUPER is not allowed.
		1287	for (qw(time signal child idle)) {
		1288	undef &{"AnyEvent::Base::$_"}
		1289	if defined &{"$MODEL\::$_"};
		1290	}
		1291
		1292	require AnyEvent::Strict if $ENV{PERL_ANYEVENT_STRICT};
		1293
		1294	(shift @post_detect)->() while @post_detect;
		1295
		1296	*post_detect = sub(&) {
		1297	shift->();
		1298
		1299	undef
		1300	};
1194		1301
1195	$MODEL	1302	$MODEL
1196	}	1303	}
1197		1304
1198	sub AUTOLOAD {	1305	sub AUTOLOAD {
1199	(my $func = $AUTOLOAD) =~ s/.*://;	1306	(my $func = $AUTOLOAD) =~ s/.*://;
1200		1307
1201	$method{$func}	1308	$method{$func}
1202	or Carp::croak "$func: not a valid method for AnyEvent objects";	1309	or Carp::croak "$func: not a valid AnyEvent class method";
1203		1310
1204	detect unless $MODEL;	1311	detect;
1205		1312
1206	my $class = shift;	1313	my $class = shift;
1207	$class->$func (@_);	1314	$class->$func (@_);
1208	}	1315	}
1209		1316
…		…
1222	# we assume CLOEXEC is already set by perl in all important cases	1329	# we assume CLOEXEC is already set by perl in all important cases
1223		1330
1224	($fh2, $rw)	1331	($fh2, $rw)
1225	}	1332	}
1226		1333
		1334	=head1 SIMPLIFIED AE API
		1335
		1336	Starting with version 5.0, AnyEvent officially supports a second, much
		1337	simpler, API that is designed to reduce the calling, typing and memory
		1338	overhead by using function call syntax and a fixed number of parameters.
		1339
		1340	See the L<AE> manpage for details.
		1341
		1342	=cut
		1343
		1344	package AE;
		1345
		1346	our $VERSION = $AnyEvent::VERSION;
		1347
		1348	# fall back to the main API by default - backends and AnyEvent::Base
		1349	# implementations can overwrite these.
		1350
		1351	sub io($$$) {
		1352	AnyEvent->io (fh => $_[0], poll => $_[1] ? "w" : "r", cb => $_[2])
		1353	}
		1354
		1355	sub timer($$$) {
		1356	AnyEvent->timer (after => $_[0], interval => $_[1], cb => $_[2])
		1357	}
		1358
		1359	sub signal($$) {
		1360	AnyEvent->signal (signal => $_[0], cb => $_[1])
		1361	}
		1362
		1363	sub child($$) {
		1364	AnyEvent->child (pid => $_[0], cb => $_[1])
		1365	}
		1366
		1367	sub idle($) {
		1368	AnyEvent->idle (cb => $_[0])
		1369	}
		1370
		1371	sub cv(;&) {
		1372	AnyEvent->condvar (@_ ? (cb => $_[0]) : ())
		1373	}
		1374
		1375	sub now() {
		1376	AnyEvent->now
		1377	}
		1378
		1379	sub now_update() {
		1380	AnyEvent->now_update
		1381	}
		1382
		1383	sub time() {
		1384	AnyEvent->time
		1385	}
		1386
1227	package AnyEvent::Base;	1387	package AnyEvent::Base;
1228		1388
1229	# default implementations for many methods	1389	# default implementations for many methods
1230		1390
1231	sub _time {	1391	sub time {
		1392	eval q{ # poor man's autoloading {}
1232	# probe for availability of Time::HiRes	1393	# probe for availability of Time::HiRes
1233	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {	1394	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {
1234	warn "AnyEvent: using Time::HiRes for sub-second timing accuracy.\n" if $VERBOSE >= 8;	1395	warn "AnyEvent: using Time::HiRes for sub-second timing accuracy.\n" if $VERBOSE >= 8;
1235	*_time = \&Time::HiRes::time;	1396	*AE::time = \&Time::HiRes::time;
1236	# if (eval "use POSIX (); (POSIX::times())...	1397	# if (eval "use POSIX (); (POSIX::times())...
1237	} else {	1398	} else {
1238	warn "AnyEvent: using built-in time(), WARNING, no sub-second resolution!\n" if $VERBOSE;	1399	warn "AnyEvent: using built-in time(), WARNING, no sub-second resolution!\n" if $VERBOSE;
1239	*_time = sub { time }; # epic fail	1400	*AE::time = sub (){ time }; # epic fail
		1401	}
		1402
		1403	*time = sub { AE::time }; # different prototypes
1240	}	1404	};
		1405	die if $@;
1241		1406
1242	&_time	1407	&time
1243	}	1408	}
1244		1409
1245	sub time { _time }	1410	*now = \&time;
1246	sub now { _time }	1411
1247	sub now_update { }	1412	sub now_update { }
1248		1413
1249	# default implementation for ->condvar	1414	# default implementation for ->condvar
1250		1415
1251	sub condvar {	1416	sub condvar {
		1417	eval q{ # poor man's autoloading {}
		1418	*condvar = sub {
1252	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"	1419	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"
		1420	};
		1421
		1422	*AE::cv = sub (;&) {
		1423	bless { @_ ? (_ae_cb => shift) : () }, "AnyEvent::CondVar"
		1424	};
		1425	};
		1426	die if $@;
		1427
		1428	&condvar
1253	}	1429	}
1254		1430
1255	# default implementation for ->signal	1431	# default implementation for ->signal
1256		1432
1257	our $HAVE_ASYNC_INTERRUPT;	1433	our $HAVE_ASYNC_INTERRUPT;
		1434
		1435	sub _have_async_interrupt() {
		1436	$HAVE_ASYNC_INTERRUPT = 1*(!$ENV{PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT}
		1437	&& eval "use Async::Interrupt 1.02 (); 1")
		1438	unless defined $HAVE_ASYNC_INTERRUPT;
		1439
		1440	$HAVE_ASYNC_INTERRUPT
		1441	}
		1442
1258	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);	1443	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);
1259	our (%SIG_ASY, %SIG_ASY_W);	1444	our (%SIG_ASY, %SIG_ASY_W);
1260	our ($SIG_COUNT, $SIG_TW);	1445	our ($SIG_COUNT, $SIG_TW);
1261		1446
1262	sub _signal_exec {	1447	# install a dummy wakeup watcher to reduce signal catching latency
1263	$HAVE_ASYNC_INTERRUPT	1448	# used by Impls
1264	? $SIGPIPE_R->drain	1449	sub _sig_add() {
1265	: sysread $SIGPIPE_R, my $dummy, 9;	1450	unless ($SIG_COUNT++) {
		1451	# try to align timer on a full-second boundary, if possible
		1452	my $NOW = AE::now;
1266		1453
1267	while (%SIG_EV) {	1454	$SIG_TW = AE::timer
1268	for (keys %SIG_EV) {	1455	$MAX_SIGNAL_LATENCY - ($NOW - int $NOW),
1269	delete $SIG_EV{$_};	1456	$MAX_SIGNAL_LATENCY,
1270	$_->() for values %{ $SIG_CB{$_} || {} };	1457	sub { } # just for the PERL_ASYNC_CHECK
1271	}	1458	;
1272	}	1459	}
1273	}	1460	}
1274		1461
1275	sub _signal {	1462	sub _sig_del {
1276	my (undef, %arg) = @_;
1277
1278	my $signal = uc $arg{signal}
1279	or Carp::croak "required option 'signal' is missing";
1280
1281	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
1282
1283	if ($HAVE_ASYNC_INTERRUPT) {
1284	# async::interrupt
1285
1286	$SIG_ASY{$signal} ||= do {
1287	my $asy = new Async::Interrupt
1288	cb => sub { undef $SIG_EV{$signal} },
1289	signal => $signal,
1290	pipe => [$SIGPIPE_R->filenos],
1291	;
1292	$asy->pipe_autodrain (0);
1293
1294	$asy
1295	};
1296
1297	} else {
1298	# pure perl
1299
1300	$SIG{$signal} ||= sub {
1301	local $!;
1302	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;
1303	undef $SIG_EV{$signal};
1304	};
1305
1306	# can't do signal processing without introducing races in pure perl,
1307	# so limit the signal latency.
1308	++$SIG_COUNT;
1309	$SIG_TW ||= AnyEvent->timer (
1310	after => $MAX_SIGNAL_LATENCY,
1311	interval => $MAX_SIGNAL_LATENCY,
1312	cb => sub { }, # just for the PERL_ASYNC_CHECK
1313	);
1314	}
1315
1316	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
1317	}
1318
1319	sub signal {
1320	# probe for availability of Async::Interrupt
1321	if (!$ENV{PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT} && eval "use Async::Interrupt 0.6 (); 1") {
1322	warn "AnyEvent: using Async::Interrupt for race-free signal handling.\n" if $VERBOSE >= 8;
1323
1324	$HAVE_ASYNC_INTERRUPT = 1;
1325	$SIGPIPE_R = new Async::Interrupt::EventPipe;
1326	$SIG_IO = AnyEvent->io (fh => $SIGPIPE_R->fileno, poll => "r", cb => \&_signal_exec);
1327
1328	} else {
1329	warn "AnyEvent: using emulated perl signal handling with latency timer.\n" if $VERBOSE >= 8;
1330
1331	require Fcntl;
1332
1333	if (AnyEvent::WIN32) {
1334	require AnyEvent::Util;
1335
1336	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
1337	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R) if $SIGPIPE_R;
1338	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W) if $SIGPIPE_W; # just in case
1339	} else {
1340	pipe $SIGPIPE_R, $SIGPIPE_W;
1341	fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R;
1342	fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case
1343
1344	# not strictly required, as $^F is normally 2, but let's make sure...
1345	fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
1346	fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
1347	}
1348
1349	$SIGPIPE_R
1350	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";
1351
1352	$SIG_IO = AnyEvent->io (fh => $SIGPIPE_R, poll => "r", cb => \&_signal_exec);
1353	}
1354
1355	*signal = \&_signal;
1356	&signal
1357	}
1358
1359	sub AnyEvent::Base::signal::DESTROY {
1360	my ($signal, $cb) = @{$_[0]};
1361
1362	undef $SIG_TW	1463	undef $SIG_TW
1363	unless --$SIG_COUNT;	1464	unless --$SIG_COUNT;
		1465	}
1364		1466
		1467	our $_sig_name_init; $_sig_name_init = sub {
		1468	eval q{ # poor man's autoloading {}
		1469	undef $_sig_name_init;
		1470
		1471	if (_have_async_interrupt) {
		1472	*sig2num = \&Async::Interrupt::sig2num;
		1473	*sig2name = \&Async::Interrupt::sig2name;
		1474	} else {
		1475	require Config;
		1476
		1477	my %signame2num;
		1478	@signame2num{ split ' ', $Config::Config{sig_name} }
		1479	= split ' ', $Config::Config{sig_num};
		1480
		1481	my @signum2name;
		1482	@signum2name[values %signame2num] = keys %signame2num;
		1483
		1484	*sig2num = sub($) {
		1485	$_[0] > 0 ? shift : $signame2num{+shift}
		1486	};
		1487	*sig2name = sub ($) {
		1488	$_[0] > 0 ? $signum2name[+shift] : shift
		1489	};
		1490	}
		1491	};
		1492	die if $@;
		1493	};
		1494
		1495	sub sig2num ($) { &$_sig_name_init; &sig2num }
		1496	sub sig2name($) { &$_sig_name_init; &sig2name }
		1497
		1498	sub signal {
		1499	eval q{ # poor man's autoloading {}
		1500	# probe for availability of Async::Interrupt
		1501	if (_have_async_interrupt) {
		1502	warn "AnyEvent: using Async::Interrupt for race-free signal handling.\n" if $VERBOSE >= 8;
		1503
		1504	$SIGPIPE_R = new Async::Interrupt::EventPipe;
		1505	$SIG_IO = AE::io $SIGPIPE_R->fileno, 0, \&_signal_exec;
		1506
		1507	} else {
		1508	warn "AnyEvent: using emulated perl signal handling with latency timer.\n" if $VERBOSE >= 8;
		1509
		1510	if (AnyEvent::WIN32) {
		1511	require AnyEvent::Util;
		1512
		1513	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
		1514	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R, 1) if $SIGPIPE_R;
		1515	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W, 1) if $SIGPIPE_W; # just in case
		1516	} else {
		1517	pipe $SIGPIPE_R, $SIGPIPE_W;
		1518	fcntl $SIGPIPE_R, AnyEvent::F_SETFL, AnyEvent::O_NONBLOCK if $SIGPIPE_R;
		1519	fcntl $SIGPIPE_W, AnyEvent::F_SETFL, AnyEvent::O_NONBLOCK if $SIGPIPE_W; # just in case
		1520
		1521	# not strictly required, as $^F is normally 2, but let's make sure...
		1522	fcntl $SIGPIPE_R, AnyEvent::F_SETFD, AnyEvent::FD_CLOEXEC;
		1523	fcntl $SIGPIPE_W, AnyEvent::F_SETFD, AnyEvent::FD_CLOEXEC;
		1524	}
		1525
		1526	$SIGPIPE_R
		1527	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";
		1528
		1529	$SIG_IO = AE::io $SIGPIPE_R, 0, \&_signal_exec;
		1530	}
		1531
		1532	*signal = $HAVE_ASYNC_INTERRUPT
		1533	? sub {
		1534	my (undef, %arg) = @_;
		1535
		1536	# async::interrupt
		1537	my $signal = sig2num $arg{signal};
		1538	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
		1539
		1540	$SIG_ASY{$signal} ||= new Async::Interrupt
		1541	cb => sub { undef $SIG_EV{$signal} },
		1542	signal => $signal,
		1543	pipe => [$SIGPIPE_R->filenos],
		1544	pipe_autodrain => 0,
		1545	;
		1546
		1547	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
		1548	}
		1549	: sub {
		1550	my (undef, %arg) = @_;
		1551
		1552	# pure perl
		1553	my $signal = sig2name $arg{signal};
		1554	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
		1555
		1556	$SIG{$signal} ||= sub {
		1557	local $!;
		1558	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;
		1559	undef $SIG_EV{$signal};
		1560	};
		1561
		1562	# can't do signal processing without introducing races in pure perl,
		1563	# so limit the signal latency.
		1564	_sig_add;
		1565
		1566	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
		1567	}
		1568	;
		1569
		1570	*AnyEvent::Base::signal::DESTROY = sub {
		1571	my ($signal, $cb) = @{$_[0]};
		1572
		1573	_sig_del;
		1574
1365	delete $SIG_CB{$signal}{$cb};	1575	delete $SIG_CB{$signal}{$cb};
1366		1576
		1577	$HAVE_ASYNC_INTERRUPT
		1578	? delete $SIG_ASY{$signal}
1367	# delete doesn't work with older perls - they then	1579	: # delete doesn't work with older perls - they then
1368	# print weird messages, or just unconditionally exit	1580	# print weird messages, or just unconditionally exit
1369	# instead of getting the default action.	1581	# instead of getting the default action.
1370	undef $SIG{$signal}	1582	undef $SIG{$signal}
1371	unless keys %{ $SIG_CB{$signal} };	1583	unless keys %{ $SIG_CB{$signal} };
		1584	};
		1585
		1586	*_signal_exec = sub {
		1587	$HAVE_ASYNC_INTERRUPT
		1588	? $SIGPIPE_R->drain
		1589	: sysread $SIGPIPE_R, (my $dummy), 9;
		1590
		1591	while (%SIG_EV) {
		1592	for (keys %SIG_EV) {
		1593	delete $SIG_EV{$_};
		1594	$_->() for values %{ $SIG_CB{$_} || {} };
		1595	}
		1596	}
		1597	};
		1598	};
		1599	die if $@;
		1600
		1601	&signal
1372	}	1602	}
1373		1603
1374	# default implementation for ->child	1604	# default implementation for ->child
1375		1605
1376	our %PID_CB;	1606	our %PID_CB;
1377	our $CHLD_W;	1607	our $CHLD_W;
1378	our $CHLD_DELAY_W;	1608	our $CHLD_DELAY_W;
1379	our $WNOHANG;	1609	our $WNOHANG;
1380		1610
1381	sub _sigchld {	1611	# used by many Impl's
1382	while (0 < (my $pid = waitpid -1, $WNOHANG)) {	1612	sub _emit_childstatus($$) {
1383	$_->($pid, $?)	1613	my (undef, $rpid, $rstatus) = @_;
		1614
		1615	$_->($rpid, $rstatus)
1384	for values %{ $PID_CB{$pid} || {} },	1616	for values %{ $PID_CB{$rpid} || {} },
1385	values %{ $PID_CB{0} || {} };	1617	values %{ $PID_CB{0} || {} };
1386	}
1387	}	1618	}
1388		1619
1389	sub child {	1620	sub child {
		1621	eval q{ # poor man's autoloading {}
		1622	*_sigchld = sub {
		1623	my $pid;
		1624
		1625	AnyEvent->_emit_childstatus ($pid, $?)
		1626	while ($pid = waitpid -1, $WNOHANG) > 0;
		1627	};
		1628
		1629	*child = sub {
1390	my (undef, %arg) = @_;	1630	my (undef, %arg) = @_;
1391		1631
1392	defined (my $pid = $arg{pid} + 0)	1632	defined (my $pid = $arg{pid} + 0)
1393	or Carp::croak "required option 'pid' is missing";	1633	or Carp::croak "required option 'pid' is missing";
1394		1634
1395	$PID_CB{$pid}{$arg{cb}} = $arg{cb};	1635	$PID_CB{$pid}{$arg{cb}} = $arg{cb};
1396		1636
1397	# WNOHANG is almost cetrainly 1 everywhere	1637	# WNOHANG is almost cetrainly 1 everywhere
1398	$WNOHANG ||= $^O =~ /^(?:openbsd|netbsd|linux|freebsd|cygwin|MSWin32)$/	1638	$WNOHANG ||= $^O =~ /^(?:openbsd|netbsd|linux|freebsd|cygwin|MSWin32)$/
1399	? 1	1639	? 1
1400	: eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1;	1640	: eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1;
1401		1641
1402	unless ($CHLD_W) {	1642	unless ($CHLD_W) {
1403	$CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld);	1643	$CHLD_W = AE::signal CHLD => \&_sigchld;
1404	# child could be a zombie already, so make at least one round	1644	# child could be a zombie already, so make at least one round
1405	&_sigchld;	1645	&_sigchld;
1406	}	1646	}
1407		1647
1408	bless [$pid, $arg{cb}], "AnyEvent::Base::child"	1648	bless [$pid, $arg{cb}], "AnyEvent::Base::child"
1409	}	1649	};
1410		1650
1411	sub AnyEvent::Base::child::DESTROY {	1651	*AnyEvent::Base::child::DESTROY = sub {
1412	my ($pid, $cb) = @{$_[0]};	1652	my ($pid, $cb) = @{$_[0]};
1413		1653
1414	delete $PID_CB{$pid}{$cb};	1654	delete $PID_CB{$pid}{$cb};
1415	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };	1655	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };
1416		1656
1417	undef $CHLD_W unless keys %PID_CB;	1657	undef $CHLD_W unless keys %PID_CB;
		1658	};
		1659	};
		1660	die if $@;
		1661
		1662	&child
1418	}	1663	}
1419		1664
1420	# idle emulation is done by simply using a timer, regardless	1665	# idle emulation is done by simply using a timer, regardless
1421	# of whether the process is idle or not, and not letting	1666	# of whether the process is idle or not, and not letting
1422	# the callback use more than 50% of the time.	1667	# the callback use more than 50% of the time.
1423	sub idle {	1668	sub idle {
		1669	eval q{ # poor man's autoloading {}
		1670	*idle = sub {
1424	my (undef, %arg) = @_;	1671	my (undef, %arg) = @_;
1425		1672
1426	my ($cb, $w, $rcb) = $arg{cb};	1673	my ($cb, $w, $rcb) = $arg{cb};
1427		1674
1428	$rcb = sub {	1675	$rcb = sub {
1429	if ($cb) {	1676	if ($cb) {
1430	$w = _time;	1677	$w = _time;
1431	&$cb;	1678	&$cb;
1432	$w = _time - $w;	1679	$w = _time - $w;
1433		1680
1434	# never use more then 50% of the time for the idle watcher,	1681	# never use more then 50% of the time for the idle watcher,
1435	# within some limits	1682	# within some limits
1436	$w = 0.0001 if $w < 0.0001;	1683	$w = 0.0001 if $w < 0.0001;
1437	$w = 5 if $w > 5;	1684	$w = 5 if $w > 5;
1438		1685
1439	$w = AnyEvent->timer (after => $w, cb => $rcb);	1686	$w = AE::timer $w, 0, $rcb;
1440	} else {	1687	} else {
1441	# clean up...	1688	# clean up...
1442	undef $w;	1689	undef $w;
1443	undef $rcb;	1690	undef $rcb;
		1691	}
		1692	};
		1693
		1694	$w = AE::timer 0.05, 0, $rcb;
		1695
		1696	bless \\$cb, "AnyEvent::Base::idle"
1444	}	1697	};
		1698
		1699	*AnyEvent::Base::idle::DESTROY = sub {
		1700	undef $${$_[0]};
		1701	};
1445	};	1702	};
		1703	die if $@;
1446		1704
1447	$w = AnyEvent->timer (after => 0.05, cb => $rcb);	1705	&idle
1448
1449	bless \\$cb, "AnyEvent::Base::idle"
1450	}
1451
1452	sub AnyEvent::Base::idle::DESTROY {
1453	undef $${$_[0]};
1454	}	1706	}
1455		1707
1456	package AnyEvent::CondVar;	1708	package AnyEvent::CondVar;
1457		1709
1458	our @ISA = AnyEvent::CondVar::Base::;	1710	our @ISA = AnyEvent::CondVar::Base::;
…		…
1506	Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak};	1758	Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak};
1507	wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0]	1759	wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0]
1508	}	1760	}
1509		1761
1510	sub cb {	1762	sub cb {
1511	$_[0]{_ae_cb} = $_[1] if @_ > 1;	1763	my $cv = shift;
		1764
		1765	@_
		1766	and $cv->{_ae_cb} = shift
		1767	and $cv->{_ae_sent}
		1768	and (delete $cv->{_ae_cb})->($cv);
		1769
1512	$_[0]{_ae_cb}	1770	$cv->{_ae_cb}
1513	}	1771	}
1514		1772
1515	sub begin {	1773	sub begin {
1516	++$_[0]{_ae_counter};	1774	++$_[0]{_ae_counter};
1517	$_[0]{_ae_end_cb} = $_[1] if @_ > 1;	1775	$_[0]{_ae_end_cb} = $_[1] if @_ > 1;
…		…
1565	conditions, such as not being able to load the event model specified by	1823	conditions, such as not being able to load the event model specified by
1566	C<PERL_ANYEVENT_MODEL>.	1824	C<PERL_ANYEVENT_MODEL>.
1567		1825
1568	When set to C<2> or higher, cause AnyEvent to report to STDERR which event	1826	When set to C<2> or higher, cause AnyEvent to report to STDERR which event
1569	model it chooses.	1827	model it chooses.
		1828
		1829	When set to C<8> or higher, then AnyEvent will report extra information on
		1830	which optional modules it loads and how it implements certain features.
1570		1831
1571	=item C<PERL_ANYEVENT_STRICT>	1832	=item C<PERL_ANYEVENT_STRICT>
1572		1833
1573	AnyEvent does not do much argument checking by default, as thorough	1834	AnyEvent does not do much argument checking by default, as thorough
1574	argument checking is very costly. Setting this variable to a true value	1835	argument checking is very costly. Setting this variable to a true value
…		…
1651		1912
1652	When neither C<ca_file> nor C<ca_path> was specified during	1913	When neither C<ca_file> nor C<ca_path> was specified during
1653	L<AnyEvent::TLS> context creation, and either of these environment	1914	L<AnyEvent::TLS> context creation, and either of these environment
1654	variables exist, they will be used to specify CA certificate locations	1915	variables exist, they will be used to specify CA certificate locations
1655	instead of a system-dependent default.	1916	instead of a system-dependent default.
		1917
		1918	=item C<PERL_ANYEVENT_AVOID_GUARD> and C<PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT>
		1919
		1920	When these are set to C<1>, then the respective modules are not
		1921	loaded. Mostly good for testing AnyEvent itself.
1656		1922
1657	=back	1923	=back
1658		1924
1659	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE	1925	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE
1660		1926
…		…
1718	warn "read: $input\n"; # output what has been read	1984	warn "read: $input\n"; # output what has been read
1719	$cv->send if $input =~ /^q/i; # quit program if /^q/i	1985	$cv->send if $input =~ /^q/i; # quit program if /^q/i
1720	},	1986	},
1721	);	1987	);
1722		1988
1723	my $time_watcher; # can only be used once
1724
1725	sub new_timer {
1726	$timer = AnyEvent->timer (after => 1, cb => sub {	1989	my $time_watcher = AnyEvent->timer (after => 1, interval => 1, cb => sub {
1727	warn "timeout\n"; # print 'timeout' about every second	1990	warn "timeout\n"; # print 'timeout' at most every second
1728	&new_timer; # and restart the time
1729	});	1991	});
1730	}
1731
1732	new_timer; # create first timer
1733		1992
1734	$cv->recv; # wait until user enters /^q/i	1993	$cv->recv; # wait until user enters /^q/i
1735		1994
1736	=head1 REAL-WORLD EXAMPLE	1995	=head1 REAL-WORLD EXAMPLE
1737		1996
…		…
1810		2069
1811	The actual code goes further and collects all errors (C<die>s, exceptions)	2070	The actual code goes further and collects all errors (C<die>s, exceptions)
1812	that occurred during request processing. The C<result> method detects	2071	that occurred during request processing. The C<result> method detects
1813	whether an exception as thrown (it is stored inside the $txn object)	2072	whether an exception as thrown (it is stored inside the $txn object)
1814	and just throws the exception, which means connection errors and other	2073	and just throws the exception, which means connection errors and other
1815	problems get reported tot he code that tries to use the result, not in a	2074	problems get reported to the code that tries to use the result, not in a
1816	random callback.	2075	random callback.
1817		2076
1818	All of this enables the following usage styles:	2077	All of this enables the following usage styles:
1819		2078
1820	1. Blocking:	2079	1. Blocking:
…		…
1868	through AnyEvent. The benchmark creates a lot of timers (with a zero	2127	through AnyEvent. The benchmark creates a lot of timers (with a zero
1869	timeout) and I/O watchers (watching STDOUT, a pty, to become writable,	2128	timeout) and I/O watchers (watching STDOUT, a pty, to become writable,
1870	which it is), lets them fire exactly once and destroys them again.	2129	which it is), lets them fire exactly once and destroys them again.
1871		2130
1872	Source code for this benchmark is found as F<eg/bench> in the AnyEvent	2131	Source code for this benchmark is found as F<eg/bench> in the AnyEvent
1873	distribution.	2132	distribution. It uses the L<AE> interface, which makes a real difference
		2133	for the EV and Perl backends only.
1874		2134
1875	=head3 Explanation of the columns	2135	=head3 Explanation of the columns
1876		2136
1877	I<watcher> is the number of event watchers created/destroyed. Since	2137	I<watcher> is the number of event watchers created/destroyed. Since
1878	different event models feature vastly different performances, each event	2138	different event models feature vastly different performances, each event
…		…
1899	watcher.	2159	watcher.
1900		2160
1901	=head3 Results	2161	=head3 Results
1902		2162
1903	name watchers bytes create invoke destroy comment	2163	name watchers bytes create invoke destroy comment
1904	EV/EV 400000 224 0.47 0.35 0.27 EV native interface	2164	EV/EV 100000 223 0.47 0.43 0.27 EV native interface
1905	EV/Any 100000 224 2.88 0.34 0.27 EV + AnyEvent watchers	2165	EV/Any 100000 223 0.48 0.42 0.26 EV + AnyEvent watchers
1906	CoroEV/Any 100000 224 2.85 0.35 0.28 coroutines + Coro::Signal	2166	Coro::EV/Any 100000 223 0.47 0.42 0.26 coroutines + Coro::Signal
1907	Perl/Any 100000 452 4.13 0.73 0.95 pure perl implementation	2167	Perl/Any 100000 431 2.70 0.74 0.92 pure perl implementation
1908	Event/Event 16000 517 32.20 31.80 0.81 Event native interface	2168	Event/Event 16000 516 31.16 31.84 0.82 Event native interface
1909	Event/Any 16000 590 35.85 31.55 1.06 Event + AnyEvent watchers	2169	Event/Any 16000 1203 42.61 34.79 1.80 Event + AnyEvent watchers
1910	IOAsync/Any 16000 989 38.10 32.77 11.13 via IO::Async::Loop::IO_Poll	2170	IOAsync/Any 16000 1911 41.92 27.45 16.81 via IO::Async::Loop::IO_Poll
1911	IOAsync/Any 16000 990 37.59 29.50 10.61 via IO::Async::Loop::Epoll	2171	IOAsync/Any 16000 1726 40.69 26.37 15.25 via IO::Async::Loop::Epoll
1912	Glib/Any 16000 1357 102.33 12.31 51.00 quadratic behaviour	2172	Glib/Any 16000 1118 89.00 12.57 51.17 quadratic behaviour
1913	Tk/Any 2000 1860 27.20 66.31 14.00 SEGV with >> 2000 watchers	2173	Tk/Any 2000 1346 20.96 10.75 8.00 SEGV with >> 2000 watchers
1914	POE/Event 2000 6328 109.99 751.67 14.02 via POE::Loop::Event	2174	POE/Any 2000 6951 108.97 795.32 14.24 via POE::Loop::Event
1915	POE/Select 2000 6027 94.54 809.13 579.80 via POE::Loop::Select	2175	POE/Any 2000 6648 94.79 774.40 575.51 via POE::Loop::Select
1916		2176
1917	=head3 Discussion	2177	=head3 Discussion
1918		2178
1919	The benchmark does I<not> measure scalability of the event loop very	2179	The benchmark does I<not> measure scalability of the event loop very
1920	well. For example, a select-based event loop (such as the pure perl one)	2180	well. For example, a select-based event loop (such as the pure perl one)
…		…
1932	benchmark machine, handling an event takes roughly 1600 CPU cycles with	2192	benchmark machine, handling an event takes roughly 1600 CPU cycles with
1933	EV, 3100 CPU cycles with AnyEvent's pure perl loop and almost 3000000 CPU	2193	EV, 3100 CPU cycles with AnyEvent's pure perl loop and almost 3000000 CPU
1934	cycles with POE.	2194	cycles with POE.
1935		2195
1936	C<EV> is the sole leader regarding speed and memory use, which are both	2196	C<EV> is the sole leader regarding speed and memory use, which are both
1937	maximal/minimal, respectively. Even when going through AnyEvent, it uses	2197	maximal/minimal, respectively. When using the L<AE> API there is zero
		2198	overhead (when going through the AnyEvent API create is about 5-6 times
		2199	slower, with other times being equal, so still uses far less memory than
1938	far less memory than any other event loop and is still faster than Event	2200	any other event loop and is still faster than Event natively).
1939	natively.
1940		2201
1941	The pure perl implementation is hit in a few sweet spots (both the	2202	The pure perl implementation is hit in a few sweet spots (both the
1942	constant timeout and the use of a single fd hit optimisations in the perl	2203	constant timeout and the use of a single fd hit optimisations in the perl
1943	interpreter and the backend itself). Nevertheless this shows that it	2204	interpreter and the backend itself). Nevertheless this shows that it
1944	adds very little overhead in itself. Like any select-based backend its	2205	adds very little overhead in itself. Like any select-based backend its
…		…
2018	In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100	2279	In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100
2019	(1%) are active. This mirrors the activity of large servers with many	2280	(1%) are active. This mirrors the activity of large servers with many
2020	connections, most of which are idle at any one point in time.	2281	connections, most of which are idle at any one point in time.
2021		2282
2022	Source code for this benchmark is found as F<eg/bench2> in the AnyEvent	2283	Source code for this benchmark is found as F<eg/bench2> in the AnyEvent
2023	distribution.	2284	distribution. It uses the L<AE> interface, which makes a real difference
		2285	for the EV and Perl backends only.
2024		2286
2025	=head3 Explanation of the columns	2287	=head3 Explanation of the columns
2026		2288
2027	I<sockets> is the number of sockets, and twice the number of "servers" (as	2289	I<sockets> is the number of sockets, and twice the number of "servers" (as
2028	each server has a read and write socket end).	2290	each server has a read and write socket end).
…		…
2036	a new one that moves the timeout into the future.	2298	a new one that moves the timeout into the future.
2037		2299
2038	=head3 Results	2300	=head3 Results
2039		2301
2040	name sockets create request	2302	name sockets create request
2041	EV 20000 69.01 11.16	2303	EV 20000 62.66 7.99
2042	Perl 20000 73.32 35.87	2304	Perl 20000 68.32 32.64
2043	IOAsync 20000 157.00 98.14 epoll	2305	IOAsync 20000 174.06 101.15 epoll
2044	IOAsync 20000 159.31 616.06 poll	2306	IOAsync 20000 174.67 610.84 poll
2045	Event 20000 212.62 257.32	2307	Event 20000 202.69 242.91
2046	Glib 20000 651.16 1896.30	2308	Glib 20000 557.01 1689.52
2047	POE 20000 349.67 12317.24 uses POE::Loop::Event	2309	POE 20000 341.54 12086.32 uses POE::Loop::Event
2048		2310
2049	=head3 Discussion	2311	=head3 Discussion
2050		2312
2051	This benchmark I<does> measure scalability and overall performance of the	2313	This benchmark I<does> measure scalability and overall performance of the
2052	particular event loop.	2314	particular event loop.
…		…
2178	As you can see, the AnyEvent + EV combination even beats the	2440	As you can see, the AnyEvent + EV combination even beats the
2179	hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl	2441	hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl
2180	backend easily beats IO::Lambda and POE.	2442	backend easily beats IO::Lambda and POE.
2181		2443
2182	And even the 100% non-blocking version written using the high-level (and	2444	And even the 100% non-blocking version written using the high-level (and
2183	slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda by a	2445	slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda
2184	large margin, even though it does all of DNS, tcp-connect and socket I/O	2446	higher level ("unoptimised") abstractions by a large margin, even though
2185	in a non-blocking way.	2447	it does all of DNS, tcp-connect and socket I/O in a non-blocking way.
2186		2448
2187	The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and	2449	The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and
2188	F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are	2450	F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are
2189	part of the IO::lambda distribution and were used without any changes.	2451	part of the IO::Lambda distribution and were used without any changes.
2190		2452
2191		2453
2192	=head1 SIGNALS	2454	=head1 SIGNALS
2193		2455
2194	AnyEvent currently installs handlers for these signals:	2456	AnyEvent currently installs handlers for these signals:
…		…
2236	it's built-in modules) are required to use it.	2498	it's built-in modules) are required to use it.
2237		2499
2238	That does not mean that AnyEvent won't take advantage of some additional	2500	That does not mean that AnyEvent won't take advantage of some additional
2239	modules if they are installed.	2501	modules if they are installed.
2240		2502
2241	This section epxlains which additional modules will be used, and how they	2503	This section explains which additional modules will be used, and how they
2242	affect AnyEvent's operetion.	2504	affect AnyEvent's operation.
2243		2505
2244	=over 4	2506	=over 4
2245		2507
2246	=item L<Async::Interrupt>	2508	=item L<Async::Interrupt>
2247		2509
2248	This slightly arcane module is used to implement fast signal handling: To	2510	This slightly arcane module is used to implement fast signal handling: To
2249	my knowledge, there is no way to do completely race-free and quick	2511	my knowledge, there is no way to do completely race-free and quick
2250	signal handling in pure perl. To ensure that signals still get	2512	signal handling in pure perl. To ensure that signals still get
2251	delivered, AnyEvent will start an interval timer to wake up perl (and	2513	delivered, AnyEvent will start an interval timer to wake up perl (and
2252	catch the signals) with soemd elay (default is 10 seconds, look for	2514	catch the signals) with some delay (default is 10 seconds, look for
2253	C<$AnyEvent::MAX_SIGNAL_LATENCY>).	2515	C<$AnyEvent::MAX_SIGNAL_LATENCY>).
2254		2516
2255	If this module is available, then it will be used to implement signal	2517	If this module is available, then it will be used to implement signal
2256	catching, which means that signals will not be delayed, and the event loop	2518	catching, which means that signals will not be delayed, and the event loop
2257	will not be interrupted regularly, which is more efficient (And good for	2519	will not be interrupted regularly, which is more efficient (and good for
2258	battery life on laptops).	2520	battery life on laptops).
2259		2521
2260	This affects not just the pure-perl event loop, but also other event loops	2522	This affects not just the pure-perl event loop, but also other event loops
2261	that have no signal handling on their own (e.g. Glib, Tk, Qt).	2523	that have no signal handling on their own (e.g. Glib, Tk, Qt).
		2524
		2525	Some event loops (POE, Event, Event::Lib) offer signal watchers natively,
		2526	and either employ their own workarounds (POE) or use AnyEvent's workaround
		2527	(using C<$AnyEvent::MAX_SIGNAL_LATENCY>). Installing L<Async::Interrupt>
		2528	does nothing for those backends.
2262		2529
2263	=item L<EV>	2530	=item L<EV>
2264		2531
2265	This module isn't really "optional", as it is simply one of the backend	2532	This module isn't really "optional", as it is simply one of the backend
2266	event loops that AnyEvent can use. However, it is simply the best event	2533	event loops that AnyEvent can use. However, it is simply the best event
…		…
2269	automatic timer adjustments even when no monotonic clock is available,	2536	automatic timer adjustments even when no monotonic clock is available,
2270	can take avdantage of advanced kernel interfaces such as C<epoll> and	2537	can take avdantage of advanced kernel interfaces such as C<epoll> and
2271	C<kqueue>, and is the fastest backend I<by far>. You can even embed	2538	C<kqueue>, and is the fastest backend I<by far>. You can even embed
2272	L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>).	2539	L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>).
2273		2540
		2541	If you only use backends that rely on another event loop (e.g. C<Tk>),
		2542	then this module will do nothing for you.
		2543
2274	=item L<Guard>	2544	=item L<Guard>
2275		2545
2276	The guard module, when used, will be used to implement	2546	The guard module, when used, will be used to implement
2277	C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a	2547	C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a
2278	lot less memory), but otherwise doesn't affect guard operation much. It is	2548	lot less memory), but otherwise doesn't affect guard operation much. It is
2279	purely used for performance.	2549	purely used for performance.
2280		2550
2281	=item L<JSON> and L<JSON::XS>	2551	=item L<JSON> and L<JSON::XS>
2282		2552
2283	This module is required when you want to read or write JSON data via	2553	One of these modules is required when you want to read or write JSON data
2284	L<AnyEvent::Handle>. It is also written in pure-perl, but can take	2554	via L<AnyEvent::Handle>. L<JSON> is also written in pure-perl, but can take
2285	advantage of the ulta-high-speed L<JSON::XS> module when it is installed.	2555	advantage of the ultra-high-speed L<JSON::XS> module when it is installed.
2286
2287	In fact, L<AnyEvent::Handle> will use L<JSON::XS> by default if it is
2288	installed.
2289		2556
2290	=item L<Net::SSLeay>	2557	=item L<Net::SSLeay>
2291		2558
2292	Implementing TLS/SSL in Perl is certainly interesting, but not very	2559	Implementing TLS/SSL in Perl is certainly interesting, but not very
2293	worthwhile: If this module is installed, then L<AnyEvent::Handle> (with	2560	worthwhile: If this module is installed, then L<AnyEvent::Handle> (with
…		…
2304		2571
2305		2572
2306	=head1 FORK	2573	=head1 FORK
2307		2574
2308	Most event libraries are not fork-safe. The ones who are usually are	2575	Most event libraries are not fork-safe. The ones who are usually are
2309	because they rely on inefficient but fork-safe C<select> or C<poll>	2576	because they rely on inefficient but fork-safe C<select> or C<poll> calls
2310	calls. Only L<EV> is fully fork-aware.	2577	- higher performance APIs such as BSD's kqueue or the dreaded Linux epoll
		2578	are usually badly thought-out hacks that are incompatible with fork in
		2579	one way or another. Only L<EV> is fully fork-aware and ensures that you
		2580	continue event-processing in both parent and child (or both, if you know
		2581	what you are doing).
		2582
		2583	This means that, in general, you cannot fork and do event processing in
		2584	the child if the event library was initialised before the fork (which
		2585	usually happens when the first AnyEvent watcher is created, or the library
		2586	is loaded).
2311		2587
2312	If you have to fork, you must either do so I<before> creating your first	2588	If you have to fork, you must either do so I<before> creating your first
2313	watcher OR you must not use AnyEvent at all in the child OR you must do	2589	watcher OR you must not use AnyEvent at all in the child OR you must do
2314	something completely out of the scope of AnyEvent.	2590	something completely out of the scope of AnyEvent.
		2591
		2592	The problem of doing event processing in the parent I<and> the child
		2593	is much more complicated: even for backends that I<are> fork-aware or
		2594	fork-safe, their behaviour is not usually what you want: fork clones all
		2595	watchers, that means all timers, I/O watchers etc. are active in both
		2596	parent and child, which is almost never what you want. USing C<exec>
		2597	to start worker children from some kind of manage rprocess is usually
		2598	preferred, because it is much easier and cleaner, at the expense of having
		2599	to have another binary.
2315		2600
2316		2601
2317	=head1 SECURITY CONSIDERATIONS	2602	=head1 SECURITY CONSIDERATIONS
2318		2603
2319	AnyEvent can be forced to load any event model via	2604	AnyEvent can be forced to load any event model via
…		…
2357	L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.	2642	L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.
2358		2643
2359	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,	2644	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,
2360	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,	2645	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,
2361	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,	2646	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,
2362	L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>.	2647	L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>, L<Anyevent::Impl::Irssi>.
2363		2648
2364	Non-blocking file handles, sockets, TCP clients and	2649	Non-blocking file handles, sockets, TCP clients and
2365	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.	2650	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.
2366		2651
2367	Asynchronous DNS: L<AnyEvent::DNS>.	2652	Asynchronous DNS: L<AnyEvent::DNS>.

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