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Revision 1.276 by root, Sun Aug 9 10:53:33 2009 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
…		…
40	=head1 INTRODUCTION/TUTORIAL	40	=head1 INTRODUCTION/TUTORIAL
41		41
42	This manpage is mainly a reference manual. If you are interested	42	This manpage is mainly a reference manual. If you are interested
43	in a tutorial or some gentle introduction, have a look at the	43	in a tutorial or some gentle introduction, have a look at the
44	L<AnyEvent::Intro> manpage.	44	L<AnyEvent::Intro> manpage.
		45
		46	=head1 SUPPORT
		47
		48	There is a mailinglist for discussing all things AnyEvent, and an IRC
		49	channel, too.
		50
		51	See the AnyEvent project page at the B<Schmorpforge Ta-Sa Software
		52	Repository>, at L<http://anyevent.schmorp.de>, for more info.
45		53
46	=head1 WHY YOU SHOULD USE THIS MODULE (OR NOT)	54	=head1 WHY YOU SHOULD USE THIS MODULE (OR NOT)
47		55
48	Glib, POE, IO::Async, Event... CPAN offers event models by the dozen	56	Glib, POE, IO::Async, Event... CPAN offers event models by the dozen
49	nowadays. So what is different about AnyEvent?	57	nowadays. So what is different about AnyEvent?
…		…
173	my variables are only visible after the statement in which they are	181	my variables are only visible after the statement in which they are
174	declared.	182	declared.
175		183
176	=head2 I/O WATCHERS	184	=head2 I/O WATCHERS
177		185
		186	$w = AnyEvent->io (
		187	fh => <filehandle_or_fileno>,
		188	poll => <"r" or "w">,
		189	cb => <callback>,
		190	);
		191
178	You can create an I/O watcher by calling the C<< AnyEvent->io >> method	192	You can create an I/O watcher by calling the C<< AnyEvent->io >> method
179	with the following mandatory key-value pairs as arguments:	193	with the following mandatory key-value pairs as arguments:
180		194
181	C<fh> is the Perl I<file handle> (I<not> file descriptor) to watch	195	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	196	for events (AnyEvent might or might not keep a reference to this file
183	handle). Note that only file handles pointing to things for which	197	handle). Note that only file handles pointing to things for which
184	non-blocking operation makes sense are allowed. This includes sockets,	198	non-blocking operation makes sense are allowed. This includes sockets,
185	most character devices, pipes, fifos and so on, but not for example files	199	most character devices, pipes, fifos and so on, but not for example files
186	or block devices.	200	or block devices.
…		…
211	undef $w;	225	undef $w;
212	});	226	});
213		227
214	=head2 TIME WATCHERS	228	=head2 TIME WATCHERS
215		229
		230	$w = AnyEvent->timer (after => <seconds>, cb => <callback>);
		231
		232	$w = AnyEvent->timer (
		233	after => <fractional_seconds>,
		234	interval => <fractional_seconds>,
		235	cb => <callback>,
		236	);
		237
216	You can create a time watcher by calling the C<< AnyEvent->timer >>	238	You can create a time watcher by calling the C<< AnyEvent->timer >>
217	method with the following mandatory arguments:	239	method with the following mandatory arguments:
218		240
219	C<after> specifies after how many seconds (fractional values are	241	C<after> specifies after how many seconds (fractional values are
220	supported) the callback should be invoked. C<cb> is the callback to invoke	242	supported) the callback should be invoked. C<cb> is the callback to invoke
…		…
347		369
348	=back	370	=back
349		371
350	=head2 SIGNAL WATCHERS	372	=head2 SIGNAL WATCHERS
351		373
		374	$w = AnyEvent->signal (signal => <uppercase_signal_name>, cb => <callback>);
		375
352	You can watch for signals using a signal watcher, C<signal> is the signal	376	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	377	I<name> in uppercase and without any C<SIG> prefix, C<cb> is the Perl
354	callback to be invoked whenever a signal occurs.	378	callback to be invoked whenever a signal occurs.
355		379
356	Although the callback might get passed parameters, their value and	380	Although the callback might get passed parameters, their value and
…		…
361	invocation, and callback invocation will be synchronous. Synchronous means	385	invocation, and callback invocation will be synchronous. Synchronous means
362	that it might take a while until the signal gets handled by the process,	386	that it might take a while until the signal gets handled by the process,
363	but it is guaranteed not to interrupt any other callbacks.	387	but it is guaranteed not to interrupt any other callbacks.
364		388
365	The main advantage of using these watchers is that you can share a signal	389	The main advantage of using these watchers is that you can share a signal
366	between multiple watchers.	390	between multiple watchers, and AnyEvent will ensure that signals will not
		391	interrupt your program at bad times.
367		392
368	This watcher might use C<%SIG>, so programs overwriting those signals	393	This watcher might use C<%SIG> (depending on the event loop used),
369	directly will likely not work correctly.	394	so programs overwriting those signals directly will likely not work
		395	correctly.
370		396
371	Example: exit on SIGINT	397	Example: exit on SIGINT
372		398
373	my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });	399	my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });
374		400
		401	=head3 Signal Races, Delays and Workarounds
		402
		403	Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support attaching
		404	callbacks to signals in a generic way, which is a pity, as you cannot
		405	do race-free signal handling in perl, requiring C libraries for
		406	this. AnyEvent will try to do it's best, which means in some cases,
		407	signals will be delayed. The maximum time a signal might be delayed is
		408	specified in C<$AnyEvent::MAX_SIGNAL_LATENCY> (default: 10 seconds). This
		409	variable can be changed only before the first signal watcher is created,
		410	and should be left alone otherwise. This variable determines how often
		411	AnyEvent polls for signals (in case a wake-up was missed). Higher values
		412	will cause fewer spurious wake-ups, which is better for power and CPU
		413	saving.
		414
		415	All these problems can be avoided by installing the optional
		416	L<Async::Interrupt> module, which works with most event loops. It will not
		417	work with inherently broken event loops such as L<Event> or L<Event::Lib>
		418	(and not with L<POE> currently, as POE does it's own workaround with
		419	one-second latency). For those, you just have to suffer the delays.
		420
375	=head2 CHILD PROCESS WATCHERS	421	=head2 CHILD PROCESS WATCHERS
376		422
		423	$w = AnyEvent->child (pid => <process id>, cb => <callback>);
		424
377	You can also watch on a child process exit and catch its exit status.	425	You can also watch on a child process exit and catch its exit status.
378		426
379	The child process is specified by the C<pid> argument (if set to C<0>, it	427	The child process is specified by the C<pid> argument (one some backends,
380	watches for any child process exit). The watcher will triggered only when	428	using C<0> watches for any child process exit, on others this will
381	the child process has finished and an exit status is available, not on	429	croak). The watcher will be triggered only when the child process has
382	any trace events (stopped/continued).	430	finished and an exit status is available, not on any trace events
		431	(stopped/continued).
383		432
384	The callback will be called with the pid and exit status (as returned by	433	The callback will be called with the pid and exit status (as returned by
385	waitpid), so unlike other watcher types, you I<can> rely on child watcher	434	waitpid), so unlike other watcher types, you I<can> rely on child watcher
386	callback arguments.	435	callback arguments.
387		436
…		…
403		452
404	This means you cannot create a child watcher as the very first	453	This means you cannot create a child watcher as the very first
405	thing in an AnyEvent program, you I<have> to create at least one	454	thing in an AnyEvent program, you I<have> to create at least one
406	watcher before you C<fork> the child (alternatively, you can call	455	watcher before you C<fork> the child (alternatively, you can call
407	C<AnyEvent::detect>).	456	C<AnyEvent::detect>).
		457
		458	As most event loops do not support waiting for child events, they will be
		459	emulated by AnyEvent in most cases, in which the latency and race problems
		460	mentioned in the description of signal watchers apply.
408		461
409	Example: fork a process and wait for it	462	Example: fork a process and wait for it
410		463
411	my $done = AnyEvent->condvar;	464	my $done = AnyEvent->condvar;
412		465
…		…
424	# do something else, then wait for process exit	477	# do something else, then wait for process exit
425	$done->recv;	478	$done->recv;
426		479
427	=head2 IDLE WATCHERS	480	=head2 IDLE WATCHERS
428		481
		482	$w = AnyEvent->idle (cb => <callback>);
		483
429	Sometimes there is a need to do something, but it is not so important	484	Sometimes there is a need to do something, but it is not so important
430	to do it instantly, but only when there is nothing better to do. This	485	to do it instantly, but only when there is nothing better to do. This
431	"nothing better to do" is usually defined to be "no other events need	486	"nothing better to do" is usually defined to be "no other events need
432	attention by the event loop".	487	attention by the event loop".
433		488
…		…
459	});	514	});
460	});	515	});
461		516
462	=head2 CONDITION VARIABLES	517	=head2 CONDITION VARIABLES
463		518
		519	$cv = AnyEvent->condvar;
		520
		521	$cv->send (<list>);
		522	my @res = $cv->recv;
		523
464	If you are familiar with some event loops you will know that all of them	524	If you are familiar with some event loops you will know that all of them
465	require you to run some blocking "loop", "run" or similar function that	525	require you to run some blocking "loop", "run" or similar function that
466	will actively watch for new events and call your callbacks.	526	will actively watch for new events and call your callbacks.
467		527
468	AnyEvent is different, it expects somebody else to run the event loop and	528	AnyEvent is slightly different: it expects somebody else to run the event
469	will only block when necessary (usually when told by the user).	529	loop and will only block when necessary (usually when told by the user).
470		530
471	The instrument to do that is called a "condition variable", so called	531	The instrument to do that is called a "condition variable", so called
472	because they represent a condition that must become true.	532	because they represent a condition that must become true.
473		533
		534	Now is probably a good time to look at the examples further below.
		535
474	Condition variables can be created by calling the C<< AnyEvent->condvar	536	Condition variables can be created by calling the C<< AnyEvent->condvar
475	>> method, usually without arguments. The only argument pair allowed is	537	>> method, usually without arguments. The only argument pair allowed is
476
477	C<cb>, which specifies a callback to be called when the condition variable	538	C<cb>, which specifies a callback to be called when the condition variable
478	becomes true, with the condition variable as the first argument (but not	539	becomes true, with the condition variable as the first argument (but not
479	the results).	540	the results).
480		541
481	After creation, the condition variable is "false" until it becomes "true"	542	After creation, the condition variable is "false" until it becomes "true"
…		…
486	Condition variables are similar to callbacks, except that you can	547	Condition variables are similar to callbacks, except that you can
487	optionally wait for them. They can also be called merge points - points	548	optionally wait for them. They can also be called merge points - points
488	in time where multiple outstanding events have been processed. And yet	549	in time where multiple outstanding events have been processed. And yet
489	another way to call them is transactions - each condition variable can be	550	another way to call them is transactions - each condition variable can be
490	used to represent a transaction, which finishes at some point and delivers	551	used to represent a transaction, which finishes at some point and delivers
491	a result.	552	a result. And yet some people know them as "futures" - a promise to
		553	compute/deliver something that you can wait for.
492		554
493	Condition variables are very useful to signal that something has finished,	555	Condition variables are very useful to signal that something has finished,
494	for example, if you write a module that does asynchronous http requests,	556	for example, if you write a module that does asynchronous http requests,
495	then a condition variable would be the ideal candidate to signal the	557	then a condition variable would be the ideal candidate to signal the
496	availability of results. The user can either act when the callback is	558	availability of results. The user can either act when the callback is
…		…
530	after => 1,	592	after => 1,
531	cb => sub { $result_ready->send },	593	cb => sub { $result_ready->send },
532	);	594	);
533		595
534	# this "blocks" (while handling events) till the callback	596	# this "blocks" (while handling events) till the callback
535	# calls send	597	# calls -<send
536	$result_ready->recv;	598	$result_ready->recv;
537		599
538	Example: wait for a timer, but take advantage of the fact that	600	Example: wait for a timer, but take advantage of the fact that condition
539	condition variables are also code references.	601	variables are also callable directly.
540		602
541	my $done = AnyEvent->condvar;	603	my $done = AnyEvent->condvar;
542	my $delay = AnyEvent->timer (after => 5, cb => $done);	604	my $delay = AnyEvent->timer (after => 5, cb => $done);
543	$done->recv;	605	$done->recv;
544		606
…		…
550		612
551	...	613	...
552		614
553	my @info = $couchdb->info->recv;	615	my @info = $couchdb->info->recv;
554		616
555	And this is how you would just ste a callback to be called whenever the	617	And this is how you would just set a callback to be called whenever the
556	results are available:	618	results are available:
557		619
558	$couchdb->info->cb (sub {	620	$couchdb->info->cb (sub {
559	my @info = $_[0]->recv;	621	my @info = $_[0]->recv;
560	});	622	});
…		…
578	immediately from within send.	640	immediately from within send.
579		641
580	Any arguments passed to the C<send> call will be returned by all	642	Any arguments passed to the C<send> call will be returned by all
581	future C<< ->recv >> calls.	643	future C<< ->recv >> calls.
582		644
583	Condition variables are overloaded so one can call them directly	645	Condition variables are overloaded so one can call them directly (as if
584	(as a code reference). Calling them directly is the same as calling	646	they were a code reference). Calling them directly is the same as calling
585	C<send>. Note, however, that many C-based event loops do not handle	647	C<send>.
586	overloading, so as tempting as it may be, passing a condition variable
587	instead of a callback does not work. Both the pure perl and EV loops
588	support overloading, however, as well as all functions that use perl to
589	invoke a callback (as in L<AnyEvent::Socket> and L<AnyEvent::DNS> for
590	example).
591		648
592	=item $cv->croak ($error)	649	=item $cv->croak ($error)
593		650
594	Similar to send, but causes all call's to C<< ->recv >> to invoke	651	Similar to send, but causes all call's to C<< ->recv >> to invoke
595	C<Carp::croak> with the given error message/object/scalar.	652	C<Carp::croak> with the given error message/object/scalar.
596		653
597	This can be used to signal any errors to the condition variable	654	This can be used to signal any errors to the condition variable
598	user/consumer.	655	user/consumer. Doing it this way instead of calling C<croak> directly
		656	delays the error detetcion, but has the overwhelmign advantage that it
		657	diagnoses the error at the place where the result is expected, and not
		658	deep in some event clalback without connection to the actual code causing
		659	the problem.
599		660
600	=item $cv->begin ([group callback])	661	=item $cv->begin ([group callback])
601		662
602	=item $cv->end	663	=item $cv->end
603
604	These two methods are EXPERIMENTAL and MIGHT CHANGE.
605		664
606	These two methods can be used to combine many transactions/events into	665	These two methods can be used to combine many transactions/events into
607	one. For example, a function that pings many hosts in parallel might want	666	one. For example, a function that pings many hosts in parallel might want
608	to use a condition variable for the whole process.	667	to use a condition variable for the whole process.
609		668
…		…
611	C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end	670	C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end
612	>>, the (last) callback passed to C<begin> will be executed. That callback	671	>>, the (last) callback passed to C<begin> will be executed. That callback
613	is I<supposed> to call C<< ->send >>, but that is not required. If no	672	is I<supposed> to call C<< ->send >>, but that is not required. If no
614	callback was set, C<send> will be called without any arguments.	673	callback was set, C<send> will be called without any arguments.
615		674
616	Let's clarify this with the ping example:	675	You can think of C<< $cv->send >> giving you an OR condition (one call
		676	sends), while C<< $cv->begin >> and C<< $cv->end >> giving you an AND
		677	condition (all C<begin> calls must be C<end>'ed before the condvar sends).
		678
		679	Let's start with a simple example: you have two I/O watchers (for example,
		680	STDOUT and STDERR for a program), and you want to wait for both streams to
		681	close before activating a condvar:
		682
		683	my $cv = AnyEvent->condvar;
		684
		685	$cv->begin; # first watcher
		686	my $w1 = AnyEvent->io (fh => $fh1, cb => sub {
		687	defined sysread $fh1, my $buf, 4096
		688	or $cv->end;
		689	});
		690
		691	$cv->begin; # second watcher
		692	my $w2 = AnyEvent->io (fh => $fh2, cb => sub {
		693	defined sysread $fh2, my $buf, 4096
		694	or $cv->end;
		695	});
		696
		697	$cv->recv;
		698
		699	This works because for every event source (EOF on file handle), there is
		700	one call to C<begin>, so the condvar waits for all calls to C<end> before
		701	sending.
		702
		703	The ping example mentioned above is slightly more complicated, as the
		704	there are results to be passwd back, and the number of tasks that are
		705	begung can potentially be zero:
617		706
618	my $cv = AnyEvent->condvar;	707	my $cv = AnyEvent->condvar;
619		708
620	my %result;	709	my %result;
621	$cv->begin (sub { $cv->send (\%result) });	710	$cv->begin (sub { $cv->send (\%result) });
…		…
641	loop, which serves two important purposes: first, it sets the callback	730	loop, which serves two important purposes: first, it sets the callback
642	to be called once the counter reaches C<0>, and second, it ensures that	731	to be called once the counter reaches C<0>, and second, it ensures that
643	C<send> is called even when C<no> hosts are being pinged (the loop	732	C<send> is called even when C<no> hosts are being pinged (the loop
644	doesn't execute once).	733	doesn't execute once).
645		734
646	This is the general pattern when you "fan out" into multiple subrequests:	735	This is the general pattern when you "fan out" into multiple (but
647	use an outer C<begin>/C<end> pair to set the callback and ensure C<end>	736	potentially none) subrequests: use an outer C<begin>/C<end> pair to set
648	is called at least once, and then, for each subrequest you start, call	737	the callback and ensure C<end> is called at least once, and then, for each
649	C<begin> and for each subrequest you finish, call C<end>.	738	subrequest you start, call C<begin> and for each subrequest you finish,
		739	call C<end>.
650		740
651	=back	741	=back
652		742
653	=head3 METHODS FOR CONSUMERS	743	=head3 METHODS FOR CONSUMERS
654		744
…		…
670	function will call C<croak>.	760	function will call C<croak>.
671		761
672	In list context, all parameters passed to C<send> will be returned,	762	In list context, all parameters passed to C<send> will be returned,
673	in scalar context only the first one will be returned.	763	in scalar context only the first one will be returned.
674		764
		765	Note that doing a blocking wait in a callback is not supported by any
		766	event loop, that is, recursive invocation of a blocking C<< ->recv
		767	>> is not allowed, and the C<recv> call will C<croak> if such a
		768	condition is detected. This condition can be slightly loosened by using
		769	L<Coro::AnyEvent>, which allows you to do a blocking C<< ->recv >> from
		770	any thread that doesn't run the event loop itself.
		771
675	Not all event models support a blocking wait - some die in that case	772	Not all event models support a blocking wait - some die in that case
676	(programs might want to do that to stay interactive), so I<if you are	773	(programs might want to do that to stay interactive), so I<if you are
677	using this from a module, never require a blocking wait>, but let the	774	using this from a module, never require a blocking wait>. Instead, let the
678	caller decide whether the call will block or not (for example, by coupling	775	caller decide whether the call will block or not (for example, by coupling
679	condition variables with some kind of request results and supporting	776	condition variables with some kind of request results and supporting
680	callbacks so the caller knows that getting the result will not block,	777	callbacks so the caller knows that getting the result will not block,
681	while still supporting blocking waits if the caller so desires).	778	while still supporting blocking waits if the caller so desires).
682		779
683	Another reason I<never> to C<< ->recv >> in a module is that you cannot
684	sensibly have two C<< ->recv >>'s in parallel, as that would require
685	multiple interpreters or coroutines/threads, none of which C<AnyEvent>
686	can supply.
687
688	The L<Coro> module, however, I<can> and I<does> supply coroutines and, in
689	fact, L<Coro::AnyEvent> replaces AnyEvent's condvars by coroutine-safe
690	versions and also integrates coroutines into AnyEvent, making blocking
691	C<< ->recv >> calls perfectly safe as long as they are done from another
692	coroutine (one that doesn't run the event loop).
693
694	You can ensure that C<< -recv >> never blocks by setting a callback and	780	You can ensure that C<< -recv >> never blocks by setting a callback and
695	only calling C<< ->recv >> from within that callback (or at a later	781	only calling C<< ->recv >> from within that callback (or at a later
696	time). This will work even when the event loop does not support blocking	782	time). This will work even when the event loop does not support blocking
697	waits otherwise.	783	waits otherwise.
698		784
…		…
704	=item $cb = $cv->cb ($cb->($cv))	790	=item $cb = $cv->cb ($cb->($cv))
705		791
706	This is a mutator function that returns the callback set and optionally	792	This is a mutator function that returns the callback set and optionally
707	replaces it before doing so.	793	replaces it before doing so.
708		794
709	The callback will be called when the condition becomes "true", i.e. when	795	The callback will be called when the condition becomes (or already was)
710	C<send> or C<croak> are called, with the only argument being the condition	796	"true", i.e. when C<send> or C<croak> are called (or were called), with
711	variable itself. Calling C<recv> inside the callback or at any later time	797	the only argument being the condition variable itself. Calling C<recv>
712	is guaranteed not to block.	798	inside the callback or at any later time is guaranteed not to block.
713		799
714	=back	800	=back
715		801
		802	=head1 SUPPORTED EVENT LOOPS/BACKENDS
		803
		804	The available backend classes are (every class has its own manpage):
		805
		806	=over 4
		807
		808	=item Backends that are autoprobed when no other event loop can be found.
		809
		810	EV is the preferred backend when no other event loop seems to be in
		811	use. If EV is not installed, then AnyEvent will fall back to its own
		812	pure-perl implementation, which is available everywhere as it comes with
		813	AnyEvent itself.
		814
		815	AnyEvent::Impl::EV based on EV (interface to libev, best choice).
		816	AnyEvent::Impl::Perl pure-perl implementation, fast and portable.
		817
		818	=item Backends that are transparently being picked up when they are used.
		819
		820	These will be used when they are currently loaded when the first watcher
		821	is created, in which case it is assumed that the application is using
		822	them. This means that AnyEvent will automatically pick the right backend
		823	when the main program loads an event module before anything starts to
		824	create watchers. Nothing special needs to be done by the main program.
		825
		826	AnyEvent::Impl::Event based on Event, very stable, few glitches.
		827	AnyEvent::Impl::Glib based on Glib, slow but very stable.
		828	AnyEvent::Impl::Tk based on Tk, very broken.
		829	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
		830	AnyEvent::Impl::POE based on POE, very slow, some limitations.
		831	AnyEvent::Impl::Irssi used when running within irssi.
		832
		833	=item Backends with special needs.
		834
		835	Qt requires the Qt::Application to be instantiated first, but will
		836	otherwise be picked up automatically. As long as the main program
		837	instantiates the application before any AnyEvent watchers are created,
		838	everything should just work.
		839
		840	AnyEvent::Impl::Qt based on Qt.
		841
		842	Support for IO::Async can only be partial, as it is too broken and
		843	architecturally limited to even support the AnyEvent API. It also
		844	is the only event loop that needs the loop to be set explicitly, so
		845	it can only be used by a main program knowing about AnyEvent. See
		846	L<AnyEvent::Impl::Async> for the gory details.
		847
		848	AnyEvent::Impl::IOAsync based on IO::Async, cannot be autoprobed.
		849
		850	=item Event loops that are indirectly supported via other backends.
		851
		852	Some event loops can be supported via other modules:
		853
		854	There is no direct support for WxWidgets (L<Wx>) or L<Prima>.
		855
		856	B<WxWidgets> has no support for watching file handles. However, you can
		857	use WxWidgets through the POE adaptor, as POE has a Wx backend that simply
		858	polls 20 times per second, which was considered to be too horrible to even
		859	consider for AnyEvent.
		860
		861	B<Prima> is not supported as nobody seems to be using it, but it has a POE
		862	backend, so it can be supported through POE.
		863
		864	AnyEvent knows about both L<Prima> and L<Wx>, however, and will try to
		865	load L<POE> when detecting them, in the hope that POE will pick them up,
		866	in which case everything will be automatic.
		867
		868	=back
		869
716	=head1 GLOBAL VARIABLES AND FUNCTIONS	870	=head1 GLOBAL VARIABLES AND FUNCTIONS
717		871
		872	These are not normally required to use AnyEvent, but can be useful to
		873	write AnyEvent extension modules.
		874
718	=over 4	875	=over 4
719		876
720	=item $AnyEvent::MODEL	877	=item $AnyEvent::MODEL
721		878
722	Contains C<undef> until the first watcher is being created. Then it	879	Contains C<undef> until the first watcher is being created, before the
		880	backend has been autodetected.
		881
723	contains the event model that is being used, which is the name of the	882	Afterwards it contains the event model that is being used, which is the
724	Perl class implementing the model. This class is usually one of the	883	name of the Perl class implementing the model. This class is usually one
725	C<AnyEvent::Impl:xxx> modules, but can be any other class in the case	884	of the C<AnyEvent::Impl:xxx> modules, but can be any other class in the
726	AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode>).	885	case AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode> it
727		886	will be C<urxvt::anyevent>).
728	The known classes so far are:
729
730	AnyEvent::Impl::EV based on EV (an interface to libev, best choice).
731	AnyEvent::Impl::Event based on Event, second best choice.
732	AnyEvent::Impl::Perl pure-perl implementation, fast and portable.
733	AnyEvent::Impl::Glib based on Glib, third-best choice.
734	AnyEvent::Impl::Tk based on Tk, very bad choice.
735	AnyEvent::Impl::Qt based on Qt, cannot be autoprobed (see its docs).
736	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
737	AnyEvent::Impl::POE based on POE, not generic enough for full support.
738
739	# warning, support for IO::Async is only partial, as it is too broken
740	# and limited toe ven support the AnyEvent API. See AnyEvent::Impl::Async.
741	AnyEvent::Impl::IOAsync based on IO::Async, cannot be autoprobed (see its docs).
742
743	There is no support for WxWidgets, as WxWidgets has no support for
744	watching file handles. However, you can use WxWidgets through the
745	POE Adaptor, as POE has a Wx backend that simply polls 20 times per
746	second, which was considered to be too horrible to even consider for
747	AnyEvent. Likewise, other POE backends can be used by AnyEvent by using
748	it's adaptor.
749
750	AnyEvent knows about L<Prima> and L<Wx> and will try to use L<POE> when
751	autodetecting them.
752		887
753	=item AnyEvent::detect	888	=item AnyEvent::detect
754		889
755	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model	890	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model
756	if necessary. You should only call this function right before you would	891	if necessary. You should only call this function right before you would
757	have created an AnyEvent watcher anyway, that is, as late as possible at	892	have created an AnyEvent watcher anyway, that is, as late as possible at
758	runtime.	893	runtime, and not e.g. while initialising of your module.
		894
		895	If you need to do some initialisation before AnyEvent watchers are
		896	created, use C<post_detect>.
759		897
760	=item $guard = AnyEvent::post_detect { BLOCK }	898	=item $guard = AnyEvent::post_detect { BLOCK }
761		899
762	Arranges for the code block to be executed as soon as the event model is	900	Arranges for the code block to be executed as soon as the event model is
763	autodetected (or immediately if this has already happened).	901	autodetected (or immediately if this has already happened).
764		902
		903	The block will be executed I<after> the actual backend has been detected
		904	(C<$AnyEvent::MODEL> is set), but I<before> any watchers have been
		905	created, so it is possible to e.g. patch C<@AnyEvent::ISA> or do
		906	other initialisations - see the sources of L<AnyEvent::Strict> or
		907	L<AnyEvent::AIO> to see how this is used.
		908
		909	The most common usage is to create some global watchers, without forcing
		910	event module detection too early, for example, L<AnyEvent::AIO> creates
		911	and installs the global L<IO::AIO> watcher in a C<post_detect> block to
		912	avoid autodetecting the event module at load time.
		913
765	If called in scalar or list context, then it creates and returns an object	914	If called in scalar or list context, then it creates and returns an object
766	that automatically removes the callback again when it is destroyed. See	915	that automatically removes the callback again when it is destroyed (or
		916	C<undef> when the hook was immediately executed). See L<AnyEvent::AIO> for
767	L<Coro::BDB> for a case where this is useful.	917	a case where this is useful.
		918
		919	Example: Create a watcher for the IO::AIO module and store it in
		920	C<$WATCHER>. Only do so after the event loop is initialised, though.
		921
		922	our WATCHER;
		923
		924	my $guard = AnyEvent::post_detect {
		925	$WATCHER = AnyEvent->io (fh => IO::AIO::poll_fileno, poll => 'r', cb => \&IO::AIO::poll_cb);
		926	};
		927
		928	# the ||= is important in case post_detect immediately runs the block,
		929	# as to not clobber the newly-created watcher. assigning both watcher and
		930	# post_detect guard to the same variable has the advantage of users being
		931	# able to just C<undef $WATCHER> if the watcher causes them grief.
		932
		933	$WATCHER ||= $guard;
768		934
769	=item @AnyEvent::post_detect	935	=item @AnyEvent::post_detect
770		936
771	If there are any code references in this array (you can C<push> to it	937	If there are any code references in this array (you can C<push> to it
772	before or after loading AnyEvent), then they will called directly after	938	before or after loading AnyEvent), then they will called directly after
773	the event loop has been chosen.	939	the event loop has been chosen.
774		940
775	You should check C<$AnyEvent::MODEL> before adding to this array, though:	941	You should check C<$AnyEvent::MODEL> before adding to this array, though:
776	if it contains a true value then the event loop has already been detected,	942	if it is defined then the event loop has already been detected, and the
777	and the array will be ignored.	943	array will be ignored.
778		944
779	Best use C<AnyEvent::post_detect { BLOCK }> instead.	945	Best use C<AnyEvent::post_detect { BLOCK }> when your application allows
		946	it,as it takes care of these details.
		947
		948	This variable is mainly useful for modules that can do something useful
		949	when AnyEvent is used and thus want to know when it is initialised, but do
		950	not need to even load it by default. This array provides the means to hook
		951	into AnyEvent passively, without loading it.
780		952
781	=back	953	=back
782		954
783	=head1 WHAT TO DO IN A MODULE	955	=head1 WHAT TO DO IN A MODULE
784		956
…		…
839		1011
840		1012
841	=head1 OTHER MODULES	1013	=head1 OTHER MODULES
842		1014
843	The following is a non-exhaustive list of additional modules that use	1015	The following is a non-exhaustive list of additional modules that use
844	AnyEvent and can therefore be mixed easily with other AnyEvent modules	1016	AnyEvent as a client and can therefore be mixed easily with other AnyEvent
845	in the same program. Some of the modules come with AnyEvent, some are	1017	modules and other event loops in the same program. Some of the modules
846	available via CPAN.	1018	come with AnyEvent, most are available via CPAN.
847		1019
848	=over 4	1020	=over 4
849		1021
850	=item L<AnyEvent::Util>	1022	=item L<AnyEvent::Util>
851		1023
…		…
860		1032
861	=item L<AnyEvent::Handle>	1033	=item L<AnyEvent::Handle>
862		1034
863	Provide read and write buffers, manages watchers for reads and writes,	1035	Provide read and write buffers, manages watchers for reads and writes,
864	supports raw and formatted I/O, I/O queued and fully transparent and	1036	supports raw and formatted I/O, I/O queued and fully transparent and
865	non-blocking SSL/TLS.	1037	non-blocking SSL/TLS (via L<AnyEvent::TLS>.
866		1038
867	=item L<AnyEvent::DNS>	1039	=item L<AnyEvent::DNS>
868		1040
869	Provides rich asynchronous DNS resolver capabilities.	1041	Provides rich asynchronous DNS resolver capabilities.
870		1042
…		…
898		1070
899	=item L<AnyEvent::GPSD>	1071	=item L<AnyEvent::GPSD>
900		1072
901	A non-blocking interface to gpsd, a daemon delivering GPS information.	1073	A non-blocking interface to gpsd, a daemon delivering GPS information.
902		1074
		1075	=item L<AnyEvent::IRC>
		1076
		1077	AnyEvent based IRC client module family (replacing the older Net::IRC3).
		1078
		1079	=item L<AnyEvent::XMPP>
		1080
		1081	AnyEvent based XMPP (Jabber protocol) module family (replacing the older
		1082	Net::XMPP2>.
		1083
903	=item L<AnyEvent::IGS>	1084	=item L<AnyEvent::IGS>
904		1085
905	A non-blocking interface to the Internet Go Server protocol (used by	1086	A non-blocking interface to the Internet Go Server protocol (used by
906	L<App::IGS>).	1087	L<App::IGS>).
907		1088
908	=item L<AnyEvent::IRC>
909
910	AnyEvent based IRC client module family (replacing the older Net::IRC3).
911
912	=item L<Net::XMPP2>
913
914	AnyEvent based XMPP (Jabber protocol) module family.
915
916	=item L<Net::FCP>	1089	=item L<Net::FCP>
917		1090
918	AnyEvent-based implementation of the Freenet Client Protocol, birthplace	1091	AnyEvent-based implementation of the Freenet Client Protocol, birthplace
919	of AnyEvent.	1092	of AnyEvent.
920		1093
…		…
924		1097
925	=item L<Coro>	1098	=item L<Coro>
926		1099
927	Has special support for AnyEvent via L<Coro::AnyEvent>.	1100	Has special support for AnyEvent via L<Coro::AnyEvent>.
928		1101
929	=item L<IO::Lambda>
930
931	The lambda approach to I/O - don't ask, look there. Can use AnyEvent.
932
933	=back	1102	=back
934		1103
935	=cut	1104	=cut
936		1105
937	package AnyEvent;	1106	package AnyEvent;
938		1107
		1108	# basically a tuned-down version of common::sense
		1109	sub common_sense {
939	no warnings;	1110	# no warnings
		1111	${^WARNING_BITS} ^= ${^WARNING_BITS};
940	use strict qw(vars subs);	1112	# use strict vars subs
		1113	$^H |= 0x00000600;
		1114	}
941		1115
		1116	BEGIN { AnyEvent::common_sense }
		1117
942	use Carp;	1118	use Carp ();
943		1119
944	our $VERSION = 4.412;	1120	our $VERSION = 4.92;
945	our $MODEL;	1121	our $MODEL;
946		1122
947	our $AUTOLOAD;	1123	our $AUTOLOAD;
948	our @ISA;	1124	our @ISA;
949		1125
950	our @REGISTRY;	1126	our @REGISTRY;
951		1127
952	our $WIN32;	1128	our $WIN32;
		1129
		1130	our $VERBOSE;
953		1131
954	BEGIN {	1132	BEGIN {
955	eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }";	1133	eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }";
956	eval "sub TAINT(){ " . (${^TAINT}*1) . " }";	1134	eval "sub TAINT(){ " . (${^TAINT}*1) . " }";
957		1135
958	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}	1136	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}
959	if ${^TAINT};	1137	if ${^TAINT};
960	}
961		1138
962	our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1;	1139	$VERBOSE = $ENV{PERL_ANYEVENT_VERBOSE}*1;
		1140
		1141	}
		1142
		1143	our $MAX_SIGNAL_LATENCY = 10;
963		1144
964	our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred	1145	our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred
965		1146
966	{	1147	{
967	my $idx;	1148	my $idx;
…		…
969	for reverse split /\s*,\s*/,	1150	for reverse split /\s*,\s*/,
970	$ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";	1151	$ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";
971	}	1152	}
972		1153
973	my @models = (	1154	my @models = (
974	[EV:: => AnyEvent::Impl::EV::],	1155	[EV:: => AnyEvent::Impl::EV:: , 1],
975	[Event:: => AnyEvent::Impl::Event::],
976	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::],	1156	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl:: , 1],
977	# everything below here will not be autoprobed	1157	# everything below here will not (normally) be autoprobed
978	# as the pureperl backend should work everywhere	1158	# as the pureperl backend should work everywhere
979	# and is usually faster	1159	# and is usually faster
		1160	[Event:: => AnyEvent::Impl::Event::, 1],
		1161	[Glib:: => AnyEvent::Impl::Glib:: , 1], # becomes extremely slow with many watchers
		1162	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
		1163	[Irssi:: => AnyEvent::Impl::Irssi::], # Irssi has a bogus "Event" package
980	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles	1164	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
981	[Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers
982	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
983	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program	1165	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program
984	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza	1166	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
985	[Wx:: => AnyEvent::Impl::POE::],	1167	[Wx:: => AnyEvent::Impl::POE::],
986	[Prima:: => AnyEvent::Impl::POE::],	1168	[Prima:: => AnyEvent::Impl::POE::],
987	# IO::Async is just too broken - we would need workaorunds for its	1169	# IO::Async is just too broken - we would need workarounds for its
988	# byzantine signal and broken child handling, among others.	1170	# byzantine signal and broken child handling, among others.
989	# IO::Async is rather hard to detect, as it doesn't have any	1171	# IO::Async is rather hard to detect, as it doesn't have any
990	# obvious default class.	1172	# obvious default class.
991	# [IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program	1173	# [0, IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program
992	# [IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program	1174	# [0, IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program
993	# [IO::Async::Notifier:: => AnyEvent::Impl::IOAsync::], # requires special main program	1175	# [0, IO::Async::Notifier:: => AnyEvent::Impl::IOAsync::], # requires special main program
994	);	1176	);
995		1177
996	our %method = map +($_ => 1),	1178	our %method = map +($_ => 1),
997	qw(io timer time now now_update signal child idle condvar one_event DESTROY);	1179	qw(io timer time now now_update signal child idle condvar one_event DESTROY);
998		1180
…		…
1002	my ($cb) = @_;	1184	my ($cb) = @_;
1003		1185
1004	if ($MODEL) {	1186	if ($MODEL) {
1005	$cb->();	1187	$cb->();
1006		1188
1007	1	1189	undef
1008	} else {	1190	} else {
1009	push @post_detect, $cb;	1191	push @post_detect, $cb;
1010		1192
1011	defined wantarray	1193	defined wantarray
1012	? bless \$cb, "AnyEvent::Util::postdetect"	1194	? bless \$cb, "AnyEvent::Util::postdetect"
…		…
1018	@post_detect = grep $_ != ${$_[0]}, @post_detect;	1200	@post_detect = grep $_ != ${$_[0]}, @post_detect;
1019	}	1201	}
1020		1202
1021	sub detect() {	1203	sub detect() {
1022	unless ($MODEL) {	1204	unless ($MODEL) {
1023	no strict 'refs';
1024	local $SIG{__DIE__};	1205	local $SIG{__DIE__};
1025		1206
1026	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {	1207	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {
1027	my $model = "AnyEvent::Impl::$1";	1208	my $model = "AnyEvent::Impl::$1";
1028	if (eval "require $model") {	1209	if (eval "require $model") {
1029	$MODEL = $model;	1210	$MODEL = $model;
1030	warn "AnyEvent: loaded model '$model' (forced by \$PERL_ANYEVENT_MODEL), using it.\n" if $verbose > 1;	1211	warn "AnyEvent: loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.\n" if $VERBOSE >= 2;
1031	} else {	1212	} else {
1032	warn "AnyEvent: unable to load model '$model' (from \$PERL_ANYEVENT_MODEL):\n$@" if $verbose;	1213	warn "AnyEvent: unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@" if $VERBOSE;
1033	}	1214	}
1034	}	1215	}
1035		1216
1036	# check for already loaded models	1217	# check for already loaded models
1037	unless ($MODEL) {	1218	unless ($MODEL) {
1038	for (@REGISTRY, @models) {	1219	for (@REGISTRY, @models) {
1039	my ($package, $model) = @$_;	1220	my ($package, $model) = @$_;
1040	if (${"$package\::VERSION"} > 0) {	1221	if (${"$package\::VERSION"} > 0) {
1041	if (eval "require $model") {	1222	if (eval "require $model") {
1042	$MODEL = $model;	1223	$MODEL = $model;
1043	warn "AnyEvent: autodetected model '$model', using it.\n" if $verbose > 1;	1224	warn "AnyEvent: autodetected model '$model', using it.\n" if $VERBOSE >= 2;
1044	last;	1225	last;
1045	}	1226	}
1046	}	1227	}
1047	}	1228	}
1048		1229
1049	unless ($MODEL) {	1230	unless ($MODEL) {
1050	# try to load a model	1231	# try to autoload a model
1051
1052	for (@REGISTRY, @models) {	1232	for (@REGISTRY, @models) {
1053	my ($package, $model) = @$_;	1233	my ($package, $model, $autoload) = @$_;
		1234	if (
		1235	$autoload
1054	if (eval "require $package"	1236	and eval "require $package"
1055	and ${"$package\::VERSION"} > 0	1237	and ${"$package\::VERSION"} > 0
1056	and eval "require $model") {	1238	and eval "require $model"
		1239	) {
1057	$MODEL = $model;	1240	$MODEL = $model;
1058	warn "AnyEvent: autoprobed model '$model', using it.\n" if $verbose > 1;	1241	warn "AnyEvent: autoloaded model '$model', using it.\n" if $VERBOSE >= 2;
1059	last;	1242	last;
1060	}	1243	}
1061	}	1244	}
1062		1245
1063	$MODEL	1246	$MODEL
…		…
1079		1262
1080	sub AUTOLOAD {	1263	sub AUTOLOAD {
1081	(my $func = $AUTOLOAD) =~ s/.*://;	1264	(my $func = $AUTOLOAD) =~ s/.*://;
1082		1265
1083	$method{$func}	1266	$method{$func}
1084	or croak "$func: not a valid method for AnyEvent objects";	1267	or Carp::croak "$func: not a valid method for AnyEvent objects";
1085		1268
1086	detect unless $MODEL;	1269	detect unless $MODEL;
1087		1270
1088	my $class = shift;	1271	my $class = shift;
1089	$class->$func (@_);	1272	$class->$func (@_);
…		…
1094	# allow only one watcher per fd, so we dup it to get a different one).	1277	# allow only one watcher per fd, so we dup it to get a different one).
1095	sub _dupfh($$;$$) {	1278	sub _dupfh($$;$$) {
1096	my ($poll, $fh, $r, $w) = @_;	1279	my ($poll, $fh, $r, $w) = @_;
1097		1280
1098	# cygwin requires the fh mode to be matching, unix doesn't	1281	# cygwin requires the fh mode to be matching, unix doesn't
1099	my ($rw, $mode) = $poll eq "r" ? ($r, "<")	1282	my ($rw, $mode) = $poll eq "r" ? ($r, "<&") : ($w, ">&");
1100	: $poll eq "w" ? ($w, ">")
1101	: Carp::croak "AnyEvent->io requires poll set to either 'r' or 'w'";
1102		1283
1103	open my $fh2, "$mode&" . fileno $fh	1284	open my $fh2, $mode, $fh
1104	or die "cannot dup() filehandle: $!,";	1285	or die "AnyEvent->io: cannot dup() filehandle in mode '$poll': $!,";
1105		1286
1106	# we assume CLOEXEC is already set by perl in all important cases	1287	# we assume CLOEXEC is already set by perl in all important cases
1107		1288
1108	($fh2, $rw)	1289	($fh2, $rw)
1109	}	1290	}
1110		1291
		1292	#############################################################################
		1293	# "new" API, currently only emulation of it
		1294	#############################################################################
		1295
		1296	package AE;
		1297
		1298	our $VERSION = $AnyEvent::VERSION;
		1299
		1300	sub io($$$) {
		1301	AnyEvent->io (fh => $_[0], poll => $_[1] ? "w" : "r", cb => $_[2])
		1302	}
		1303
		1304	sub timer($$$) {
		1305	AnyEvent->timer (after => $_[0], interval => $_[1], cb => $_[2]);
		1306	}
		1307
		1308	sub signal($$) {
		1309	AnyEvent->signal (signal => $_[0], cb => $_[1]);
		1310	}
		1311
		1312	sub child($$) {
		1313	AnyEvent->child (pid => $_[0], cb => $_[1]);
		1314	}
		1315
		1316	sub idle($) {
		1317	AnyEvent->idle (cb => $_[0]);
		1318	}
		1319
		1320	sub cv(;&) {
		1321	AnyEvent->condvar (@_ ? (cb => $_[0]) : ())
		1322	}
		1323
		1324	sub now() {
		1325	AnyEvent->now
		1326	}
		1327
		1328	sub now_update() {
		1329	AnyEvent->now_update
		1330	}
		1331
		1332	sub time() {
		1333	AnyEvent->time
		1334	}
		1335
1111	package AnyEvent::Base;	1336	package AnyEvent::Base;
1112		1337
1113	# default implementations for many methods	1338	# default implementations for many methods
1114		1339
1115	BEGIN {	1340	sub _time {
		1341	# probe for availability of Time::HiRes
1116	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {	1342	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {
		1343	warn "AnyEvent: using Time::HiRes for sub-second timing accuracy.\n" if $VERBOSE >= 8;
1117	*_time = \&Time::HiRes::time;	1344	*_time = \&Time::HiRes::time;
1118	# if (eval "use POSIX (); (POSIX::times())...	1345	# if (eval "use POSIX (); (POSIX::times())...
1119	} else {	1346	} else {
		1347	warn "AnyEvent: using built-in time(), WARNING, no sub-second resolution!\n" if $VERBOSE;
1120	*_time = sub { time }; # epic fail	1348	*_time = sub { time }; # epic fail
1121	}	1349	}
		1350
		1351	&_time
1122	}	1352	}
1123		1353
1124	sub time { _time }	1354	sub time { _time }
1125	sub now { _time }	1355	sub now { _time }
1126	sub now_update { }	1356	sub now_update { }
…		…
1131	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"	1361	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"
1132	}	1362	}
1133		1363
1134	# default implementation for ->signal	1364	# default implementation for ->signal
1135		1365
		1366	our $HAVE_ASYNC_INTERRUPT;
		1367
		1368	sub _have_async_interrupt() {
		1369	$HAVE_ASYNC_INTERRUPT = 1*(!$ENV{PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT}
		1370	&& eval "use Async::Interrupt 1.0 (); 1")
		1371	unless defined $HAVE_ASYNC_INTERRUPT;
		1372
		1373	$HAVE_ASYNC_INTERRUPT
		1374	}
		1375
1136	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);	1376	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);
		1377	our (%SIG_ASY, %SIG_ASY_W);
		1378	our ($SIG_COUNT, $SIG_TW);
1137		1379
1138	sub _signal_exec {	1380	sub _signal_exec {
		1381	$HAVE_ASYNC_INTERRUPT
		1382	? $SIGPIPE_R->drain
1139	sysread $SIGPIPE_R, my $dummy, 4;	1383	: sysread $SIGPIPE_R, my $dummy, 9;
1140		1384
1141	while (%SIG_EV) {	1385	while (%SIG_EV) {
1142	for (keys %SIG_EV) {	1386	for (keys %SIG_EV) {
1143	delete $SIG_EV{$_};	1387	delete $SIG_EV{$_};
1144	$_->() for values %{ $SIG_CB{$_} || {} };	1388	$_->() for values %{ $SIG_CB{$_} || {} };
1145	}	1389	}
1146	}	1390	}
1147	}	1391	}
1148		1392
		1393	# install a dummy wakeup watcher to reduce signal catching latency
		1394	sub _sig_add() {
		1395	unless ($SIG_COUNT++) {
		1396	# try to align timer on a full-second boundary, if possible
		1397	my $NOW = AE::now;
		1398
		1399	$SIG_TW = AE::timer
		1400	$MAX_SIGNAL_LATENCY - ($NOW - int $NOW),
		1401	$MAX_SIGNAL_LATENCY,
		1402	sub { } # just for the PERL_ASYNC_CHECK
		1403	;
		1404	}
		1405	}
		1406
		1407	sub _sig_del {
		1408	undef $SIG_TW
		1409	unless --$SIG_COUNT;
		1410	}
		1411
		1412	our $_sig_name_init; $_sig_name_init = sub {
		1413	eval q{ # poor man's autoloading
		1414	undef $_sig_name_init;
		1415
		1416	if (_have_async_interrupt) {
		1417	*sig2num = \&Async::Interrupt::sig2num;
		1418	*sig2name = \&Async::Interrupt::sig2name;
		1419	} else {
		1420	require Config;
		1421
		1422	my %signame2num;
		1423	@signame2num{ split ' ', $Config::Config{sig_name} }
		1424	= split ' ', $Config::Config{sig_num};
		1425
		1426	my @signum2name;
		1427	@signum2name[values %signame2num] = keys %signame2num;
		1428
		1429	*sig2num = sub($) {
		1430	$_[0] > 0 ? shift : $signame2num{+shift}
		1431	};
		1432	*sig2name = sub ($) {
		1433	$_[0] > 0 ? $signum2name[+shift] : shift
		1434	};
		1435	}
		1436	};
		1437	die if $@;
		1438	};
		1439
		1440	sub sig2num ($) { &$_sig_name_init; &sig2num }
		1441	sub sig2name($) { &$_sig_name_init; &sig2name }
		1442
1149	sub signal {	1443	sub signal {
1150	my (undef, %arg) = @_;	1444	eval q{ # poor man's autoloading {}
		1445	# probe for availability of Async::Interrupt
		1446	if (_have_async_interrupt) {
		1447	warn "AnyEvent: using Async::Interrupt for race-free signal handling.\n" if $VERBOSE >= 8;
1151		1448
1152	unless ($SIGPIPE_R) {	1449	$SIGPIPE_R = new Async::Interrupt::EventPipe;
1153	require Fcntl;	1450	$SIG_IO = AE::io $SIGPIPE_R->fileno, 0, \&_signal_exec;
1154		1451
1155	if (AnyEvent::WIN32) {
1156	require AnyEvent::Util;
1157
1158	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
1159	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R) if $SIGPIPE_R;
1160	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W) if $SIGPIPE_W; # just in case
1161	} else {	1452	} else {
		1453	warn "AnyEvent: using emulated perl signal handling with latency timer.\n" if $VERBOSE >= 8;
		1454
		1455	require Fcntl;
		1456
		1457	if (AnyEvent::WIN32) {
		1458	require AnyEvent::Util;
		1459
		1460	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
		1461	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R, 1) if $SIGPIPE_R;
		1462	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W, 1) if $SIGPIPE_W; # just in case
		1463	} else {
1162	pipe $SIGPIPE_R, $SIGPIPE_W;	1464	pipe $SIGPIPE_R, $SIGPIPE_W;
1163	fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R;	1465	fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R;
1164	fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case	1466	fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case
1165		1467
1166	# not strictly required, as $^F is normally 2, but let's make sure...	1468	# not strictly required, as $^F is normally 2, but let's make sure...
1167	fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;	1469	fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
1168	fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;	1470	fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
		1471	}
		1472
		1473	$SIGPIPE_R
		1474	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";
		1475
		1476	$SIG_IO = AE::io $SIGPIPE_R, 0, \&_signal_exec;
1169	}	1477	}
1170		1478
1171	$SIGPIPE_R	1479	*signal = sub {
1172	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";	1480	my (undef, %arg) = @_;
1173		1481
1174	$SIG_IO = AnyEvent->io (fh => $SIGPIPE_R, poll => "r", cb => \&_signal_exec);
1175	}
1176
1177	my $signal = uc $arg{signal}	1482	my $signal = uc $arg{signal}
1178	or Carp::croak "required option 'signal' is missing";	1483	or Carp::croak "required option 'signal' is missing";
1179		1484
		1485	if ($HAVE_ASYNC_INTERRUPT) {
		1486	# async::interrupt
		1487
		1488	$signal = sig2num $signal;
1180	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};	1489	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
		1490
		1491	$SIG_ASY{$signal} ||= new Async::Interrupt
		1492	cb => sub { undef $SIG_EV{$signal} },
		1493	signal => $signal,
		1494	pipe => [$SIGPIPE_R->filenos],
		1495	pipe_autodrain => 0,
		1496	;
		1497
		1498	} else {
		1499	# pure perl
		1500
		1501	# AE::Util has been loaded in signal
		1502	$signal = sig2name $signal;
		1503	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
		1504
1181	$SIG{$signal} ||= sub {	1505	$SIG{$signal} ||= sub {
1182	local $!;	1506	local $!;
1183	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;	1507	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;
1184	undef $SIG_EV{$signal};	1508	undef $SIG_EV{$signal};
		1509	};
		1510
		1511	# can't do signal processing without introducing races in pure perl,
		1512	# so limit the signal latency.
		1513	_sig_add;
		1514	}
		1515
		1516	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
		1517	};
		1518
		1519	*AnyEvent::Base::signal::DESTROY = sub {
		1520	my ($signal, $cb) = @{$_[0]};
		1521
		1522	_sig_del;
		1523
		1524	delete $SIG_CB{$signal}{$cb};
		1525
		1526	$HAVE_ASYNC_INTERRUPT
		1527	? delete $SIG_ASY{$signal}
		1528	: # delete doesn't work with older perls - they then
		1529	# print weird messages, or just unconditionally exit
		1530	# instead of getting the default action.
		1531	undef $SIG{$signal}
		1532	unless keys %{ $SIG_CB{$signal} };
		1533	};
1185	};	1534	};
1186		1535	die if $@;
1187	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"	1536	&signal
1188	}
1189
1190	sub AnyEvent::Base::signal::DESTROY {
1191	my ($signal, $cb) = @{$_[0]};
1192
1193	delete $SIG_CB{$signal}{$cb};
1194
1195	# delete doesn't work with older perls - they then
1196	# print weird messages, or just unconditionally exit
1197	# instead of getting the default action.
1198	undef $SIG{$signal} unless keys %{ $SIG_CB{$signal} };
1199	}	1537	}
1200		1538
1201	# default implementation for ->child	1539	# default implementation for ->child
1202		1540
1203	our %PID_CB;	1541	our %PID_CB;
1204	our $CHLD_W;	1542	our $CHLD_W;
1205	our $CHLD_DELAY_W;	1543	our $CHLD_DELAY_W;
1206	our $WNOHANG;	1544	our $WNOHANG;
1207		1545
		1546	sub _emit_childstatus($$) {
		1547	my (undef, $rpid, $rstatus) = @_;
		1548
		1549	$_->($rpid, $rstatus)
		1550	for values %{ $PID_CB{$rpid} || {} },
		1551	values %{ $PID_CB{0} || {} };
		1552	}
		1553
1208	sub _sigchld {	1554	sub _sigchld {
		1555	my $pid;
		1556
		1557	AnyEvent->_emit_childstatus ($pid, $?)
1209	while (0 < (my $pid = waitpid -1, $WNOHANG)) {	1558	while ($pid = waitpid -1, $WNOHANG) > 0;
1210	$_->($pid, $?) for (values %{ $PID_CB{$pid} || {} }),
1211	(values %{ $PID_CB{0} || {} });
1212	}
1213	}	1559	}
1214		1560
1215	sub child {	1561	sub child {
1216	my (undef, %arg) = @_;	1562	my (undef, %arg) = @_;
1217		1563
1218	defined (my $pid = $arg{pid} + 0)	1564	defined (my $pid = $arg{pid} + 0)
1219	or Carp::croak "required option 'pid' is missing";	1565	or Carp::croak "required option 'pid' is missing";
1220		1566
1221	$PID_CB{$pid}{$arg{cb}} = $arg{cb};	1567	$PID_CB{$pid}{$arg{cb}} = $arg{cb};
1222		1568
		1569	# WNOHANG is almost cetrainly 1 everywhere
		1570	$WNOHANG ||= $^O =~ /^(?:openbsd|netbsd|linux|freebsd|cygwin|MSWin32)$/
		1571	? 1
1223	$WNOHANG ||= eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1;	1572	: eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1;
1224		1573
1225	unless ($CHLD_W) {	1574	unless ($CHLD_W) {
1226	$CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld);	1575	$CHLD_W = AE::signal CHLD => \&_sigchld;
1227	# child could be a zombie already, so make at least one round	1576	# child could be a zombie already, so make at least one round
1228	&_sigchld;	1577	&_sigchld;
1229	}	1578	}
1230		1579
1231	bless [$pid, $arg{cb}], "AnyEvent::Base::child"	1580	bless [$pid, $arg{cb}], "AnyEvent::Base::child"
…		…
1257	# never use more then 50% of the time for the idle watcher,	1606	# never use more then 50% of the time for the idle watcher,
1258	# within some limits	1607	# within some limits
1259	$w = 0.0001 if $w < 0.0001;	1608	$w = 0.0001 if $w < 0.0001;
1260	$w = 5 if $w > 5;	1609	$w = 5 if $w > 5;
1261		1610
1262	$w = AnyEvent->timer (after => $w, cb => $rcb);	1611	$w = AE::timer $w, 0, $rcb;
1263	} else {	1612	} else {
1264	# clean up...	1613	# clean up...
1265	undef $w;	1614	undef $w;
1266	undef $rcb;	1615	undef $rcb;
1267	}	1616	}
1268	};	1617	};
1269		1618
1270	$w = AnyEvent->timer (after => 0.05, cb => $rcb);	1619	$w = AE::timer 0.05, 0, $rcb;
1271		1620
1272	bless \\$cb, "AnyEvent::Base::idle"	1621	bless \\$cb, "AnyEvent::Base::idle"
1273	}	1622	}
1274		1623
1275	sub AnyEvent::Base::idle::DESTROY {	1624	sub AnyEvent::Base::idle::DESTROY {
…		…
1280		1629
1281	our @ISA = AnyEvent::CondVar::Base::;	1630	our @ISA = AnyEvent::CondVar::Base::;
1282		1631
1283	package AnyEvent::CondVar::Base;	1632	package AnyEvent::CondVar::Base;
1284		1633
1285	use overload	1634	#use overload
1286	'&{}' => sub { my $self = shift; sub { $self->send (@_) } },	1635	# '&{}' => sub { my $self = shift; sub { $self->send (@_) } },
1287	fallback => 1;	1636	# fallback => 1;
		1637
		1638	# save 300+ kilobytes by dirtily hardcoding overloading
		1639	${"AnyEvent::CondVar::Base::OVERLOAD"}{dummy}++; # Register with magic by touching.
		1640	*{'AnyEvent::CondVar::Base::()'} = sub { }; # "Make it findable via fetchmethod."
		1641	*{'AnyEvent::CondVar::Base::(&{}'} = sub { my $self = shift; sub { $self->send (@_) } }; # &{}
		1642	${'AnyEvent::CondVar::Base::()'} = 1; # fallback
		1643
		1644	our $WAITING;
1288		1645
1289	sub _send {	1646	sub _send {
1290	# nop	1647	# nop
1291	}	1648	}
1292		1649
…		…
1305	sub ready {	1662	sub ready {
1306	$_[0]{_ae_sent}	1663	$_[0]{_ae_sent}
1307	}	1664	}
1308		1665
1309	sub _wait {	1666	sub _wait {
		1667	$WAITING
		1668	and !$_[0]{_ae_sent}
		1669	and Carp::croak "AnyEvent::CondVar: recursive blocking wait detected";
		1670
		1671	local $WAITING = 1;
1310	AnyEvent->one_event while !$_[0]{_ae_sent};	1672	AnyEvent->one_event while !$_[0]{_ae_sent};
1311	}	1673	}
1312		1674
1313	sub recv {	1675	sub recv {
1314	$_[0]->_wait;	1676	$_[0]->_wait;
…		…
1316	Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak};	1678	Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak};
1317	wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0]	1679	wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0]
1318	}	1680	}
1319		1681
1320	sub cb {	1682	sub cb {
1321	$_[0]{_ae_cb} = $_[1] if @_ > 1;	1683	my $cv = shift;
		1684
		1685	@_
		1686	and $cv->{_ae_cb} = shift
		1687	and $cv->{_ae_sent}
		1688	and (delete $cv->{_ae_cb})->($cv);
		1689
1322	$_[0]{_ae_cb}	1690	$cv->{_ae_cb}
1323	}	1691	}
1324		1692
1325	sub begin {	1693	sub begin {
1326	++$_[0]{_ae_counter};	1694	++$_[0]{_ae_counter};
1327	$_[0]{_ae_end_cb} = $_[1] if @_ > 1;	1695	$_[0]{_ae_end_cb} = $_[1] if @_ > 1;
…		…
1376	C<PERL_ANYEVENT_MODEL>.	1744	C<PERL_ANYEVENT_MODEL>.
1377		1745
1378	When set to C<2> or higher, cause AnyEvent to report to STDERR which event	1746	When set to C<2> or higher, cause AnyEvent to report to STDERR which event
1379	model it chooses.	1747	model it chooses.
1380		1748
		1749	When set to C<8> or higher, then AnyEvent will report extra information on
		1750	which optional modules it loads and how it implements certain features.
		1751
1381	=item C<PERL_ANYEVENT_STRICT>	1752	=item C<PERL_ANYEVENT_STRICT>
1382		1753
1383	AnyEvent does not do much argument checking by default, as thorough	1754	AnyEvent does not do much argument checking by default, as thorough
1384	argument checking is very costly. Setting this variable to a true value	1755	argument checking is very costly. Setting this variable to a true value
1385	will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly	1756	will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly
1386	check the arguments passed to most method calls. If it finds any problems,	1757	check the arguments passed to most method calls. If it finds any problems,
1387	it will croak.	1758	it will croak.
1388		1759
1389	In other words, enables "strict" mode.	1760	In other words, enables "strict" mode.
1390		1761
1391	Unlike C<use strict>, it is definitely recommended to keep it off in	1762	Unlike C<use strict> (or it's modern cousin, C<< use L<common::sense>
1392	production. Keeping C<PERL_ANYEVENT_STRICT=1> in your environment while	1763	>>, it is definitely recommended to keep it off in production. Keeping
1393	developing programs can be very useful, however.	1764	C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs
		1765	can be very useful, however.
1394		1766
1395	=item C<PERL_ANYEVENT_MODEL>	1767	=item C<PERL_ANYEVENT_MODEL>
1396		1768
1397	This can be used to specify the event model to be used by AnyEvent, before	1769	This can be used to specify the event model to be used by AnyEvent, before
1398	auto detection and -probing kicks in. It must be a string consisting	1770	auto detection and -probing kicks in. It must be a string consisting
…		…
1441		1813
1442	=item C<PERL_ANYEVENT_MAX_FORKS>	1814	=item C<PERL_ANYEVENT_MAX_FORKS>
1443		1815
1444	The maximum number of child processes that C<AnyEvent::Util::fork_call>	1816	The maximum number of child processes that C<AnyEvent::Util::fork_call>
1445	will create in parallel.	1817	will create in parallel.
		1818
		1819	=item C<PERL_ANYEVENT_MAX_OUTSTANDING_DNS>
		1820
		1821	The default value for the C<max_outstanding> parameter for the default DNS
		1822	resolver - this is the maximum number of parallel DNS requests that are
		1823	sent to the DNS server.
		1824
		1825	=item C<PERL_ANYEVENT_RESOLV_CONF>
		1826
		1827	The file to use instead of F</etc/resolv.conf> (or OS-specific
		1828	configuration) in the default resolver. When set to the empty string, no
		1829	default config will be used.
		1830
		1831	=item C<PERL_ANYEVENT_CA_FILE>, C<PERL_ANYEVENT_CA_PATH>.
		1832
		1833	When neither C<ca_file> nor C<ca_path> was specified during
		1834	L<AnyEvent::TLS> context creation, and either of these environment
		1835	variables exist, they will be used to specify CA certificate locations
		1836	instead of a system-dependent default.
		1837
		1838	=item C<PERL_ANYEVENT_AVOID_GUARD> and C<PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT>
		1839
		1840	When these are set to C<1>, then the respective modules are not
		1841	loaded. Mostly good for testing AnyEvent itself.
1446		1842
1447	=back	1843	=back
1448		1844
1449	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE	1845	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE
1450		1846
…		…
1695	EV/Any 100000 224 2.88 0.34 0.27 EV + AnyEvent watchers	2091	EV/Any 100000 224 2.88 0.34 0.27 EV + AnyEvent watchers
1696	CoroEV/Any 100000 224 2.85 0.35 0.28 coroutines + Coro::Signal	2092	CoroEV/Any 100000 224 2.85 0.35 0.28 coroutines + Coro::Signal
1697	Perl/Any 100000 452 4.13 0.73 0.95 pure perl implementation	2093	Perl/Any 100000 452 4.13 0.73 0.95 pure perl implementation
1698	Event/Event 16000 517 32.20 31.80 0.81 Event native interface	2094	Event/Event 16000 517 32.20 31.80 0.81 Event native interface
1699	Event/Any 16000 590 35.85 31.55 1.06 Event + AnyEvent watchers	2095	Event/Any 16000 590 35.85 31.55 1.06 Event + AnyEvent watchers
		2096	IOAsync/Any 16000 989 38.10 32.77 11.13 via IO::Async::Loop::IO_Poll
		2097	IOAsync/Any 16000 990 37.59 29.50 10.61 via IO::Async::Loop::Epoll
1700	Glib/Any 16000 1357 102.33 12.31 51.00 quadratic behaviour	2098	Glib/Any 16000 1357 102.33 12.31 51.00 quadratic behaviour
1701	Tk/Any 2000 1860 27.20 66.31 14.00 SEGV with >> 2000 watchers	2099	Tk/Any 2000 1860 27.20 66.31 14.00 SEGV with >> 2000 watchers
1702	POE/Event 2000 6328 109.99 751.67 14.02 via POE::Loop::Event	2100	POE/Event 2000 6328 109.99 751.67 14.02 via POE::Loop::Event
1703	POE/Select 2000 6027 94.54 809.13 579.80 via POE::Loop::Select	2101	POE/Select 2000 6027 94.54 809.13 579.80 via POE::Loop::Select
1704		2102
…		…
1733	performance becomes really bad with lots of file descriptors (and few of	2131	performance becomes really bad with lots of file descriptors (and few of
1734	them active), of course, but this was not subject of this benchmark.	2132	them active), of course, but this was not subject of this benchmark.
1735		2133
1736	The C<Event> module has a relatively high setup and callback invocation	2134	The C<Event> module has a relatively high setup and callback invocation
1737	cost, but overall scores in on the third place.	2135	cost, but overall scores in on the third place.
		2136
		2137	C<IO::Async> performs admirably well, about on par with C<Event>, even
		2138	when using its pure perl backend.
1738		2139
1739	C<Glib>'s memory usage is quite a bit higher, but it features a	2140	C<Glib>'s memory usage is quite a bit higher, but it features a
1740	faster callback invocation and overall ends up in the same class as	2141	faster callback invocation and overall ends up in the same class as
1741	C<Event>. However, Glib scales extremely badly, doubling the number of	2142	C<Event>. However, Glib scales extremely badly, doubling the number of
1742	watchers increases the processing time by more than a factor of four,	2143	watchers increases the processing time by more than a factor of four,
…		…
1820	it to another server. This includes deleting the old timeout and creating	2221	it to another server. This includes deleting the old timeout and creating
1821	a new one that moves the timeout into the future.	2222	a new one that moves the timeout into the future.
1822		2223
1823	=head3 Results	2224	=head3 Results
1824		2225
1825	name sockets create request	2226	name sockets create request
1826	EV 20000 69.01 11.16	2227	EV 20000 69.01 11.16
1827	Perl 20000 73.32 35.87	2228	Perl 20000 73.32 35.87
		2229	IOAsync 20000 157.00 98.14 epoll
		2230	IOAsync 20000 159.31 616.06 poll
1828	Event 20000 212.62 257.32	2231	Event 20000 212.62 257.32
1829	Glib 20000 651.16 1896.30	2232	Glib 20000 651.16 1896.30
1830	POE 20000 349.67 12317.24 uses POE::Loop::Event	2233	POE 20000 349.67 12317.24 uses POE::Loop::Event
1831		2234
1832	=head3 Discussion	2235	=head3 Discussion
1833		2236
1834	This benchmark I<does> measure scalability and overall performance of the	2237	This benchmark I<does> measure scalability and overall performance of the
1835	particular event loop.	2238	particular event loop.
…		…
1837	EV is again fastest. Since it is using epoll on my system, the setup time	2240	EV is again fastest. Since it is using epoll on my system, the setup time
1838	is relatively high, though.	2241	is relatively high, though.
1839		2242
1840	Perl surprisingly comes second. It is much faster than the C-based event	2243	Perl surprisingly comes second. It is much faster than the C-based event
1841	loops Event and Glib.	2244	loops Event and Glib.
		2245
		2246	IO::Async performs very well when using its epoll backend, and still quite
		2247	good compared to Glib when using its pure perl backend.
1842		2248
1843	Event suffers from high setup time as well (look at its code and you will	2249	Event suffers from high setup time as well (look at its code and you will
1844	understand why). Callback invocation also has a high overhead compared to	2250	understand why). Callback invocation also has a high overhead compared to
1845	the C<< $_->() for .. >>-style loop that the Perl event loop uses. Event	2251	the C<< $_->() for .. >>-style loop that the Perl event loop uses. Event
1846	uses select or poll in basically all documented configurations.	2252	uses select or poll in basically all documented configurations.
…		…
1979		2385
1980	A handler for C<SIGCHLD> is installed by AnyEvent's child watcher	2386	A handler for C<SIGCHLD> is installed by AnyEvent's child watcher
1981	emulation for event loops that do not support them natively. Also, some	2387	emulation for event loops that do not support them natively. Also, some
1982	event loops install a similar handler.	2388	event loops install a similar handler.
1983		2389
1984	If, when AnyEvent is loaded, SIGCHLD is set to IGNORE, then AnyEvent will	2390	Additionally, when AnyEvent is loaded and SIGCHLD is set to IGNORE, then
1985	reset it to default, to avoid losing child exit statuses.	2391	AnyEvent will reset it to default, to avoid losing child exit statuses.
1986		2392
1987	=item SIGPIPE	2393	=item SIGPIPE
1988		2394
1989	A no-op handler is installed for C<SIGPIPE> when C<$SIG{PIPE}> is C<undef>	2395	A no-op handler is installed for C<SIGPIPE> when C<$SIG{PIPE}> is C<undef>
1990	when AnyEvent gets loaded.	2396	when AnyEvent gets loaded.
…		…
2008	if $SIG{CHLD} eq 'IGNORE';	2414	if $SIG{CHLD} eq 'IGNORE';
2009		2415
2010	$SIG{PIPE} = sub { }	2416	$SIG{PIPE} = sub { }
2011	unless defined $SIG{PIPE};	2417	unless defined $SIG{PIPE};
2012		2418
		2419	=head1 RECOMMENDED/OPTIONAL MODULES
		2420
		2421	One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and
		2422	it's built-in modules) are required to use it.
		2423
		2424	That does not mean that AnyEvent won't take advantage of some additional
		2425	modules if they are installed.
		2426
		2427	This section epxlains which additional modules will be used, and how they
		2428	affect AnyEvent's operetion.
		2429
		2430	=over 4
		2431
		2432	=item L<Async::Interrupt>
		2433
		2434	This slightly arcane module is used to implement fast signal handling: To
		2435	my knowledge, there is no way to do completely race-free and quick
		2436	signal handling in pure perl. To ensure that signals still get
		2437	delivered, AnyEvent will start an interval timer to wake up perl (and
		2438	catch the signals) with some delay (default is 10 seconds, look for
		2439	C<$AnyEvent::MAX_SIGNAL_LATENCY>).
		2440
		2441	If this module is available, then it will be used to implement signal
		2442	catching, which means that signals will not be delayed, and the event loop
		2443	will not be interrupted regularly, which is more efficient (And good for
		2444	battery life on laptops).
		2445
		2446	This affects not just the pure-perl event loop, but also other event loops
		2447	that have no signal handling on their own (e.g. Glib, Tk, Qt).
		2448
		2449	Some event loops (POE, Event, Event::Lib) offer signal watchers natively,
		2450	and either employ their own workarounds (POE) or use AnyEvent's workaround
		2451	(using C<$AnyEvent::MAX_SIGNAL_LATENCY>). Installing L<Async::Interrupt>
		2452	does nothing for those backends.
		2453
		2454	=item L<EV>
		2455
		2456	This module isn't really "optional", as it is simply one of the backend
		2457	event loops that AnyEvent can use. However, it is simply the best event
		2458	loop available in terms of features, speed and stability: It supports
		2459	the AnyEvent API optimally, implements all the watcher types in XS, does
		2460	automatic timer adjustments even when no monotonic clock is available,
		2461	can take avdantage of advanced kernel interfaces such as C<epoll> and
		2462	C<kqueue>, and is the fastest backend I<by far>. You can even embed
		2463	L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>).
		2464
		2465	=item L<Guard>
		2466
		2467	The guard module, when used, will be used to implement
		2468	C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a
		2469	lot less memory), but otherwise doesn't affect guard operation much. It is
		2470	purely used for performance.
		2471
		2472	=item L<JSON> and L<JSON::XS>
		2473
		2474	This module is required when you want to read or write JSON data via
		2475	L<AnyEvent::Handle>. It is also written in pure-perl, but can take
		2476	advantage of the ultra-high-speed L<JSON::XS> module when it is installed.
		2477
		2478	In fact, L<AnyEvent::Handle> will use L<JSON::XS> by default if it is
		2479	installed.
		2480
		2481	=item L<Net::SSLeay>
		2482
		2483	Implementing TLS/SSL in Perl is certainly interesting, but not very
		2484	worthwhile: If this module is installed, then L<AnyEvent::Handle> (with
		2485	the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL.
		2486
		2487	=item L<Time::HiRes>
		2488
		2489	This module is part of perl since release 5.008. It will be used when the
		2490	chosen event library does not come with a timing source on it's own. The
		2491	pure-perl event loop (L<AnyEvent::Impl::Perl>) will additionally use it to
		2492	try to use a monotonic clock for timing stability.
		2493
		2494	=back
		2495
		2496
2013	=head1 FORK	2497	=head1 FORK
2014		2498
2015	Most event libraries are not fork-safe. The ones who are usually are	2499	Most event libraries are not fork-safe. The ones who are usually are
2016	because they rely on inefficient but fork-safe C<select> or C<poll>	2500	because they rely on inefficient but fork-safe C<select> or C<poll>
2017	calls. Only L<EV> is fully fork-aware.	2501	calls. Only L<EV> is fully fork-aware.
2018		2502
2019	If you have to fork, you must either do so I<before> creating your first	2503	If you have to fork, you must either do so I<before> creating your first
2020	watcher OR you must not use AnyEvent at all in the child.	2504	watcher OR you must not use AnyEvent at all in the child OR you must do
		2505	something completely out of the scope of AnyEvent.
2021		2506
2022		2507
2023	=head1 SECURITY CONSIDERATIONS	2508	=head1 SECURITY CONSIDERATIONS
2024		2509
2025	AnyEvent can be forced to load any event model via	2510	AnyEvent can be forced to load any event model via
…		…
2063	L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.	2548	L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.
2064		2549
2065	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,	2550	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,
2066	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,	2551	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,
2067	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,	2552	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,
2068	L<AnyEvent::Impl::POE>.	2553	L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>, L<Anyevent::Impl::Irssi>.
2069		2554
2070	Non-blocking file handles, sockets, TCP clients and	2555	Non-blocking file handles, sockets, TCP clients and
2071	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>.	2556	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.
2072		2557
2073	Asynchronous DNS: L<AnyEvent::DNS>.	2558	Asynchronous DNS: L<AnyEvent::DNS>.
2074		2559
2075	Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>,	2560	Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>,
		2561	L<Coro::Event>,
2076		2562
2077	Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>, L<AnyEvent::DNS>.	2563	Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::XMPP>,
		2564	L<AnyEvent::HTTP>.
2078		2565
2079		2566
2080	=head1 AUTHOR	2567	=head1 AUTHOR
2081		2568
2082	Marc Lehmann <schmorp@schmorp.de>	2569	Marc Lehmann <schmorp@schmorp.de>

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