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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, POE - various supported event loops	5	EV, Event, Glib, Tk, Perl, Event::Lib, Irssi, rxvt-unicode, IO::Async, Qt
		6	and POE are various supported event loops/environments.
6		7
7	=head1 SYNOPSIS	8	=head1 SYNOPSIS
8		9
9	use AnyEvent;	10	use AnyEvent;
10		11
…		…
39	=head1 INTRODUCTION/TUTORIAL	40	=head1 INTRODUCTION/TUTORIAL
40		41
41	This manpage is mainly a reference manual. If you are interested	42	This manpage is mainly a reference manual. If you are interested
42	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
43	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.
44		53
45	=head1 WHY YOU SHOULD USE THIS MODULE (OR NOT)	54	=head1 WHY YOU SHOULD USE THIS MODULE (OR NOT)
46		55
47	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
48	nowadays. So what is different about AnyEvent?	57	nowadays. So what is different about AnyEvent?
…		…
172	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
173	declared.	182	declared.
174		183
175	=head2 I/O WATCHERS	184	=head2 I/O WATCHERS
176		185
		186	$w = AnyEvent->io (
		187	fh => <filehandle_or_fileno>,
		188	poll => <"r" or "w">,
		189	cb => <callback>,
		190	);
		191
177	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
178	with the following mandatory key-value pairs as arguments:	193	with the following mandatory key-value pairs as arguments:
179		194
180	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
181	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
182	handle). Note that only file handles pointing to things for which	197	handle). Note that only file handles pointing to things for which
183	non-blocking operation makes sense are allowed. This includes sockets,	198	non-blocking operation makes sense are allowed. This includes sockets,
184	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
185	or block devices.	200	or block devices.
…		…
210	undef $w;	225	undef $w;
211	});	226	});
212		227
213	=head2 TIME WATCHERS	228	=head2 TIME WATCHERS
214		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
215	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 >>
216	method with the following mandatory arguments:	239	method with the following mandatory arguments:
217		240
218	C<after> specifies after how many seconds (fractional values are	241	C<after> specifies after how many seconds (fractional values are
219	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
…		…
346		369
347	=back	370	=back
348		371
349	=head2 SIGNAL WATCHERS	372	=head2 SIGNAL WATCHERS
350		373
		374	$w = AnyEvent->signal (signal => <uppercase_signal_name>, cb => <callback>);
		375
351	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
352	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
353	callback to be invoked whenever a signal occurs.	378	callback to be invoked whenever a signal occurs.
354		379
355	Although the callback might get passed parameters, their value and	380	Although the callback might get passed parameters, their value and
…		…
360	invocation, and callback invocation will be synchronous. Synchronous means	385	invocation, and callback invocation will be synchronous. Synchronous means
361	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,
362	but it is guaranteed not to interrupt any other callbacks.	387	but it is guaranteed not to interrupt any other callbacks.
363		388
364	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
365	between multiple watchers.	390	between multiple watchers, and AnyEvent will ensure that signals will not
		391	interrupt your program at bad times.
366		392
367	This watcher might use C<%SIG>, so programs overwriting those signals	393	This watcher might use C<%SIG> (depending on the event loop used),
368	directly will likely not work correctly.	394	so programs overwriting those signals directly will likely not work
		395	correctly.
369		396
370	Example: exit on SIGINT	397	Example: exit on SIGINT
371		398
372	my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });	399	my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });
373		400
		401	=head3 Signal Races, Delays and Workarounds
		402
		403	Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support attaching
		404	callbacks to signals in a generic way, which is a pity, as you cannot
		405	do race-free signal handling in perl, requiring C libraries for
		406	this. AnyEvent will try to do it's best, which means in some cases,
		407	signals will be delayed. The maximum time a signal might be delayed is
		408	specified in C<$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
374	=head2 CHILD PROCESS WATCHERS	421	=head2 CHILD PROCESS WATCHERS
375		422
		423	$w = AnyEvent->child (pid => <process id>, cb => <callback>);
		424
376	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.
377		426
378	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,
379	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
380	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
381	any trace events (stopped/continued).	430	finished and an exit status is available, not on any trace events
		431	(stopped/continued).
382		432
383	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
384	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
385	callback arguments.	435	callback arguments.
386		436
…		…
391		441
392	There is a slight catch to child watchers, however: you usually start them	442	There is a slight catch to child watchers, however: you usually start them
393	I<after> the child process was created, and this means the process could	443	I<after> the child process was created, and this means the process could
394	have exited already (and no SIGCHLD will be sent anymore).	444	have exited already (and no SIGCHLD will be sent anymore).
395		445
396	Not all event models handle this correctly (POE doesn't), but even for	446	Not all event models handle this correctly (neither POE nor IO::Async do,
		447	see their AnyEvent::Impl manpages for details), but even for event models
397	event models that I<do> handle this correctly, they usually need to be	448	that I<do> handle this correctly, they usually need to be loaded before
398	loaded before the process exits (i.e. before you fork in the first place).	449	the process exits (i.e. before you fork in the first place). AnyEvent's
		450	pure perl event loop handles all cases correctly regardless of when you
		451	start the watcher.
399		452
400	This means you cannot create a child watcher as the very first thing in an	453	This means you cannot create a child watcher as the very first
401	AnyEvent program, you I<have> to create at least one watcher before you	454	thing in an AnyEvent program, you I<have> to create at least one
402	C<fork> the child (alternatively, you can call C<AnyEvent::detect>).	455	watcher before you C<fork> the child (alternatively, you can call
		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.
403		461
404	Example: fork a process and wait for it	462	Example: fork a process and wait for it
405		463
406	my $done = AnyEvent->condvar;	464	my $done = AnyEvent->condvar;
407		465
…		…
419	# do something else, then wait for process exit	477	# do something else, then wait for process exit
420	$done->recv;	478	$done->recv;
421		479
422	=head2 IDLE WATCHERS	480	=head2 IDLE WATCHERS
423		481
		482	$w = AnyEvent->idle (cb => <callback>);
		483
424	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
425	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
426	"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
427	attention by the event loop".	487	attention by the event loop".
428		488
…		…
454	});	514	});
455	});	515	});
456		516
457	=head2 CONDITION VARIABLES	517	=head2 CONDITION VARIABLES
458		518
		519	$cv = AnyEvent->condvar;
		520
		521	$cv->send (<list>);
		522	my @res = $cv->recv;
		523
459	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
460	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
461	will actively watch for new events and call your callbacks.	526	will actively watch for new events and call your callbacks.
462		527
463	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
464	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).
465		530
466	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
467	because they represent a condition that must become true.	532	because they represent a condition that must become true.
468		533
		534	Now is probably a good time to look at the examples further below.
		535
469	Condition variables can be created by calling the C<< AnyEvent->condvar	536	Condition variables can be created by calling the C<< AnyEvent->condvar
470	>> method, usually without arguments. The only argument pair allowed is	537	>> method, usually without arguments. The only argument pair allowed is
471
472	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
473	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
474	the results).	540	the results).
475		541
476	After creation, the condition variable is "false" until it becomes "true"	542	After creation, the condition variable is "false" until it becomes "true"
…		…
481	Condition variables are similar to callbacks, except that you can	547	Condition variables are similar to callbacks, except that you can
482	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
483	in time where multiple outstanding events have been processed. And yet	549	in time where multiple outstanding events have been processed. And yet
484	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
485	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
486	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.
487		554
488	Condition variables are very useful to signal that something has finished,	555	Condition variables are very useful to signal that something has finished,
489	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,
490	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
491	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
…		…
525	after => 1,	592	after => 1,
526	cb => sub { $result_ready->send },	593	cb => sub { $result_ready->send },
527	);	594	);
528		595
529	# this "blocks" (while handling events) till the callback	596	# this "blocks" (while handling events) till the callback
530	# calls send	597	# calls -<send
531	$result_ready->recv;	598	$result_ready->recv;
532		599
533	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
534	condition variables are also code references.	601	variables are also callable directly.
535		602
536	my $done = AnyEvent->condvar;	603	my $done = AnyEvent->condvar;
537	my $delay = AnyEvent->timer (after => 5, cb => $done);	604	my $delay = AnyEvent->timer (after => 5, cb => $done);
538	$done->recv;	605	$done->recv;
539		606
…		…
545		612
546	...	613	...
547		614
548	my @info = $couchdb->info->recv;	615	my @info = $couchdb->info->recv;
549		616
550	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
551	results are available:	618	results are available:
552		619
553	$couchdb->info->cb (sub {	620	$couchdb->info->cb (sub {
554	my @info = $_[0]->recv;	621	my @info = $_[0]->recv;
555	});	622	});
…		…
573	immediately from within send.	640	immediately from within send.
574		641
575	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
576	future C<< ->recv >> calls.	643	future C<< ->recv >> calls.
577		644
578	Condition variables are overloaded so one can call them directly	645	Condition variables are overloaded so one can call them directly (as if
579	(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
580	C<send>. Note, however, that many C-based event loops do not handle	647	C<send>.
581	overloading, so as tempting as it may be, passing a condition variable
582	instead of a callback does not work. Both the pure perl and EV loops
583	support overloading, however, as well as all functions that use perl to
584	invoke a callback (as in L<AnyEvent::Socket> and L<AnyEvent::DNS> for
585	example).
586		648
587	=item $cv->croak ($error)	649	=item $cv->croak ($error)
588		650
589	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
590	C<Carp::croak> with the given error message/object/scalar.	652	C<Carp::croak> with the given error message/object/scalar.
591		653
592	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
593	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.
594		660
595	=item $cv->begin ([group callback])	661	=item $cv->begin ([group callback])
596		662
597	=item $cv->end	663	=item $cv->end
598
599	These two methods are EXPERIMENTAL and MIGHT CHANGE.
600		664
601	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
602	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
603	to use a condition variable for the whole process.	667	to use a condition variable for the whole process.
604		668
…		…
606	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
607	>>, 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
608	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
609	callback was set, C<send> will be called without any arguments.	673	callback was set, C<send> will be called without any arguments.
610		674
611	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:
612		706
613	my $cv = AnyEvent->condvar;	707	my $cv = AnyEvent->condvar;
614		708
615	my %result;	709	my %result;
616	$cv->begin (sub { $cv->send (\%result) });	710	$cv->begin (sub { $cv->send (\%result) });
…		…
636	loop, which serves two important purposes: first, it sets the callback	730	loop, which serves two important purposes: first, it sets the callback
637	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
638	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
639	doesn't execute once).	733	doesn't execute once).
640		734
641	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
642	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
643	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
644	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>.
645		740
646	=back	741	=back
647		742
648	=head3 METHODS FOR CONSUMERS	743	=head3 METHODS FOR CONSUMERS
649		744
…		…
665	function will call C<croak>.	760	function will call C<croak>.
666		761
667	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,
668	in scalar context only the first one will be returned.	763	in scalar context only the first one will be returned.
669		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
670	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
671	(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
672	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
673	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
674	condition variables with some kind of request results and supporting	776	condition variables with some kind of request results and supporting
675	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,
676	while still supporting blocking waits if the caller so desires).	778	while still supporting blocking waits if the caller so desires).
677		779
678	Another reason I<never> to C<< ->recv >> in a module is that you cannot
679	sensibly have two C<< ->recv >>'s in parallel, as that would require
680	multiple interpreters or coroutines/threads, none of which C<AnyEvent>
681	can supply.
682
683	The L<Coro> module, however, I<can> and I<does> supply coroutines and, in
684	fact, L<Coro::AnyEvent> replaces AnyEvent's condvars by coroutine-safe
685	versions and also integrates coroutines into AnyEvent, making blocking
686	C<< ->recv >> calls perfectly safe as long as they are done from another
687	coroutine (one that doesn't run the event loop).
688
689	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
690	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
691	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
692	waits otherwise.	783	waits otherwise.
693		784
…		…
699	=item $cb = $cv->cb ($cb->($cv))	790	=item $cb = $cv->cb ($cb->($cv))
700		791
701	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
702	replaces it before doing so.	793	replaces it before doing so.
703		794
704	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)
705	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
706	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>
707	is guaranteed not to block.	798	inside the callback or at any later time is guaranteed not to block.
708		799
709	=back	800	=back
710		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
711	=head1 GLOBAL VARIABLES AND FUNCTIONS	870	=head1 GLOBAL VARIABLES AND FUNCTIONS
712		871
		872	These are not normally required to use AnyEvent, but can be useful to
		873	write AnyEvent extension modules.
		874
713	=over 4	875	=over 4
714		876
715	=item $AnyEvent::MODEL	877	=item $AnyEvent::MODEL
716		878
717	Contains C<undef> until the first watcher is being created. Then it	879	Contains C<undef> until the first watcher is being created, before the
		880	backend has been autodetected.
		881
718	contains the event model that is being used, which is the name of the	882	Afterwards it contains the event model that is being used, which is the
719	Perl class implementing the model. This class is usually one of the	883	name of the Perl class implementing the model. This class is usually one
720	C<AnyEvent::Impl:xxx> modules, but can be any other class in the case	884	of the C<AnyEvent::Impl:xxx> modules, but can be any other class in the
721	AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode>).	885	case AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode> it
722		886	will be C<urxvt::anyevent>).
723	The known classes so far are:
724
725	AnyEvent::Impl::EV based on EV (an interface to libev, best choice).
726	AnyEvent::Impl::Event based on Event, second best choice.
727	AnyEvent::Impl::Perl pure-perl implementation, fast and portable.
728	AnyEvent::Impl::Glib based on Glib, third-best choice.
729	AnyEvent::Impl::Tk based on Tk, very bad choice.
730	AnyEvent::Impl::Qt based on Qt, cannot be autoprobed (see its docs).
731	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
732	AnyEvent::Impl::POE based on POE, not generic enough for full support.
733
734	There is no support for WxWidgets, as WxWidgets has no support for
735	watching file handles. However, you can use WxWidgets through the
736	POE Adaptor, as POE has a Wx backend that simply polls 20 times per
737	second, which was considered to be too horrible to even consider for
738	AnyEvent. Likewise, other POE backends can be used by AnyEvent by using
739	it's adaptor.
740
741	AnyEvent knows about L<Prima> and L<Wx> and will try to use L<POE> when
742	autodetecting them.
743		887
744	=item AnyEvent::detect	888	=item AnyEvent::detect
745		889
746	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model	890	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model
747	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
748	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
749	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>.
750		897
751	=item $guard = AnyEvent::post_detect { BLOCK }	898	=item $guard = AnyEvent::post_detect { BLOCK }
752		899
753	Arranges for the code block to be executed as soon as the event model is	900	Arranges for the code block to be executed as soon as the event model is
754	autodetected (or immediately if this has already happened).	901	autodetected (or immediately if this has already happened).
755		902
		903	The block will be executed I<after> the actual backend has been detected
		904	(C<$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
756	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
757	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
758	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 ||= $guard;
759		934
760	=item @AnyEvent::post_detect	935	=item @AnyEvent::post_detect
761		936
762	If there are any code references in this array (you can C<push> to it	937	If there are any code references in this array (you can C<push> to it
763	before or after loading AnyEvent), then they will called directly after	938	before or after loading AnyEvent), then they will called directly after
764	the event loop has been chosen.	939	the event loop has been chosen.
765		940
766	You should check C<$AnyEvent::MODEL> before adding to this array, though:	941	You should check C<$AnyEvent::MODEL> before adding to this array, though:
767	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
768	and the array will be ignored.	943	array will be ignored.
769		944
770	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.
771		952
772	=back	953	=back
773		954
774	=head1 WHAT TO DO IN A MODULE	955	=head1 WHAT TO DO IN A MODULE
775		956
…		…
830		1011
831		1012
832	=head1 OTHER MODULES	1013	=head1 OTHER MODULES
833		1014
834	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
835	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
836	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
837	available via CPAN.	1018	come with AnyEvent, most are available via CPAN.
838		1019
839	=over 4	1020	=over 4
840		1021
841	=item L<AnyEvent::Util>	1022	=item L<AnyEvent::Util>
842		1023
…		…
851		1032
852	=item L<AnyEvent::Handle>	1033	=item L<AnyEvent::Handle>
853		1034
854	Provide read and write buffers, manages watchers for reads and writes,	1035	Provide read and write buffers, manages watchers for reads and writes,
855	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
856	non-blocking SSL/TLS.	1037	non-blocking SSL/TLS (via L<AnyEvent::TLS>.
857		1038
858	=item L<AnyEvent::DNS>	1039	=item L<AnyEvent::DNS>
859		1040
860	Provides rich asynchronous DNS resolver capabilities.	1041	Provides rich asynchronous DNS resolver capabilities.
861		1042
…		…
889		1070
890	=item L<AnyEvent::GPSD>	1071	=item L<AnyEvent::GPSD>
891		1072
892	A non-blocking interface to gpsd, a daemon delivering GPS information.	1073	A non-blocking interface to gpsd, a daemon delivering GPS information.
893		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
894	=item L<AnyEvent::IGS>	1084	=item L<AnyEvent::IGS>
895		1085
896	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
897	L<App::IGS>).	1087	L<App::IGS>).
898		1088
899	=item L<AnyEvent::IRC>
900
901	AnyEvent based IRC client module family (replacing the older Net::IRC3).
902
903	=item L<Net::XMPP2>
904
905	AnyEvent based XMPP (Jabber protocol) module family.
906
907	=item L<Net::FCP>	1089	=item L<Net::FCP>
908		1090
909	AnyEvent-based implementation of the Freenet Client Protocol, birthplace	1091	AnyEvent-based implementation of the Freenet Client Protocol, birthplace
910	of AnyEvent.	1092	of AnyEvent.
911		1093
…		…
915		1097
916	=item L<Coro>	1098	=item L<Coro>
917		1099
918	Has special support for AnyEvent via L<Coro::AnyEvent>.	1100	Has special support for AnyEvent via L<Coro::AnyEvent>.
919		1101
920	=item L<IO::Lambda>
921
922	The lambda approach to I/O - don't ask, look there. Can use AnyEvent.
923
924	=back	1102	=back
925		1103
926	=cut	1104	=cut
927		1105
928	package AnyEvent;	1106	package AnyEvent;
929		1107
		1108	# basically a tuned-down version of common::sense
		1109	sub common_sense {
930	no warnings;	1110	# no warnings
		1111	${^WARNING_BITS} ^= ${^WARNING_BITS};
931	use strict qw(vars subs);	1112	# use strict vars subs
		1113	$^H |= 0x00000600;
		1114	}
932		1115
		1116	BEGIN { AnyEvent::common_sense }
		1117
933	use Carp;	1118	use Carp ();
934		1119
935	our $VERSION = 4.41;	1120	our $VERSION = 4.92;
936	our $MODEL;	1121	our $MODEL;
937		1122
938	our $AUTOLOAD;	1123	our $AUTOLOAD;
939	our @ISA;	1124	our @ISA;
940		1125
941	our @REGISTRY;	1126	our @REGISTRY;
942		1127
943	our $WIN32;	1128	our $WIN32;
944		1129
		1130	our $VERBOSE;
		1131
945	BEGIN {	1132	BEGIN {
946	my $win32 = ! ! ($^O =~ /mswin32/i);	1133	eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }";
947	eval "sub WIN32(){ $win32 }";	1134	eval "sub TAINT(){ " . (${^TAINT}*1) . " }";
948	}
949		1135
		1136	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}
		1137	if ${^TAINT};
		1138
950	our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1;	1139	$VERBOSE = $ENV{PERL_ANYEVENT_VERBOSE}*1;
		1140
		1141	}
		1142
		1143	our $MAX_SIGNAL_LATENCY = 10;
951		1144
952	our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred	1145	our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred
953		1146
954	{	1147	{
955	my $idx;	1148	my $idx;
…		…
957	for reverse split /\s*,\s*/,	1150	for reverse split /\s*,\s*/,
958	$ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";	1151	$ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";
959	}	1152	}
960		1153
961	my @models = (	1154	my @models = (
962	[EV:: => AnyEvent::Impl::EV::],	1155	[EV:: => AnyEvent::Impl::EV:: , 1],
963	[Event:: => AnyEvent::Impl::Event::],
964	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::],	1156	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl:: , 1],
965	# everything below here will not be autoprobed	1157	# everything below here will not (normally) be autoprobed
966	# as the pureperl backend should work everywhere	1158	# as the pureperl backend should work everywhere
967	# 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
968	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles	1164	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
969	[Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers
970	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
971	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program	1165	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program
972	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza	1166	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
973	[Wx:: => AnyEvent::Impl::POE::],	1167	[Wx:: => AnyEvent::Impl::POE::],
974	[Prima:: => AnyEvent::Impl::POE::],	1168	[Prima:: => AnyEvent::Impl::POE::],
		1169	# IO::Async is just too broken - we would need workarounds for its
		1170	# byzantine signal and broken child handling, among others.
		1171	# IO::Async is rather hard to detect, as it doesn't have any
		1172	# obvious default class.
		1173	# [0, IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program
		1174	# [0, IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program
		1175	# [0, IO::Async::Notifier:: => AnyEvent::Impl::IOAsync::], # requires special main program
975	);	1176	);
976		1177
977	our %method = map +($_ => 1),	1178	our %method = map +($_ => 1),
978	qw(io timer time now now_update signal child idle condvar one_event DESTROY);	1179	qw(io timer time now now_update signal child idle condvar one_event DESTROY);
979		1180
…		…
983	my ($cb) = @_;	1184	my ($cb) = @_;
984		1185
985	if ($MODEL) {	1186	if ($MODEL) {
986	$cb->();	1187	$cb->();
987		1188
988	1	1189	undef
989	} else {	1190	} else {
990	push @post_detect, $cb;	1191	push @post_detect, $cb;
991		1192
992	defined wantarray	1193	defined wantarray
993	? bless \$cb, "AnyEvent::Util::postdetect"	1194	? bless \$cb, "AnyEvent::Util::postdetect"
…		…
999	@post_detect = grep $_ != ${$_[0]}, @post_detect;	1200	@post_detect = grep $_ != ${$_[0]}, @post_detect;
1000	}	1201	}
1001		1202
1002	sub detect() {	1203	sub detect() {
1003	unless ($MODEL) {	1204	unless ($MODEL) {
1004	no strict 'refs';
1005	local $SIG{__DIE__};	1205	local $SIG{__DIE__};
1006		1206
1007	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {	1207	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {
1008	my $model = "AnyEvent::Impl::$1";	1208	my $model = "AnyEvent::Impl::$1";
1009	if (eval "require $model") {	1209	if (eval "require $model") {
1010	$MODEL = $model;	1210	$MODEL = $model;
1011	warn "AnyEvent: loaded model '$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 $VERBOSE >= 2;
1012	} else {	1212	} else {
1013	warn "AnyEvent: unable to load model '$model' (from \$PERL_ANYEVENT_MODEL):\n$@" if $verbose;	1213	warn "AnyEvent: unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@" if $VERBOSE;
1014	}	1214	}
1015	}	1215	}
1016		1216
1017	# check for already loaded models	1217	# check for already loaded models
1018	unless ($MODEL) {	1218	unless ($MODEL) {
1019	for (@REGISTRY, @models) {	1219	for (@REGISTRY, @models) {
1020	my ($package, $model) = @$_;	1220	my ($package, $model) = @$_;
1021	if (${"$package\::VERSION"} > 0) {	1221	if (${"$package\::VERSION"} > 0) {
1022	if (eval "require $model") {	1222	if (eval "require $model") {
1023	$MODEL = $model;	1223	$MODEL = $model;
1024	warn "AnyEvent: autodetected model '$model', using it.\n" if $verbose > 1;	1224	warn "AnyEvent: autodetected model '$model', using it.\n" if $VERBOSE >= 2;
1025	last;	1225	last;
1026	}	1226	}
1027	}	1227	}
1028	}	1228	}
1029		1229
1030	unless ($MODEL) {	1230	unless ($MODEL) {
1031	# try to load a model	1231	# try to autoload a model
1032
1033	for (@REGISTRY, @models) {	1232	for (@REGISTRY, @models) {
1034	my ($package, $model) = @$_;	1233	my ($package, $model, $autoload) = @$_;
		1234	if (
		1235	$autoload
1035	if (eval "require $package"	1236	and eval "require $package"
1036	and ${"$package\::VERSION"} > 0	1237	and ${"$package\::VERSION"} > 0
1037	and eval "require $model") {	1238	and eval "require $model"
		1239	) {
1038	$MODEL = $model;	1240	$MODEL = $model;
1039	warn "AnyEvent: autoprobed model '$model', using it.\n" if $verbose > 1;	1241	warn "AnyEvent: autoloaded model '$model', using it.\n" if $VERBOSE >= 2;
1040	last;	1242	last;
1041	}	1243	}
1042	}	1244	}
1043		1245
1044	$MODEL	1246	$MODEL
…		…
1060		1262
1061	sub AUTOLOAD {	1263	sub AUTOLOAD {
1062	(my $func = $AUTOLOAD) =~ s/.*://;	1264	(my $func = $AUTOLOAD) =~ s/.*://;
1063		1265
1064	$method{$func}	1266	$method{$func}
1065	or croak "$func: not a valid method for AnyEvent objects";	1267	or Carp::croak "$func: not a valid method for AnyEvent objects";
1066		1268
1067	detect unless $MODEL;	1269	detect unless $MODEL;
1068		1270
1069	my $class = shift;	1271	my $class = shift;
1070	$class->$func (@_);	1272	$class->$func (@_);
1071	}	1273	}
1072		1274
1073	# utility function to dup a filehandle. this is used by many backends	1275	# utility function to dup a filehandle. this is used by many backends
1074	# to support binding more than one watcher per filehandle (they usually	1276	# to support binding more than one watcher per filehandle (they usually
1075	# 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).
1076	sub _dupfh($$$$) {	1278	sub _dupfh($$;$$) {
1077	my ($poll, $fh, $r, $w) = @_;	1279	my ($poll, $fh, $r, $w) = @_;
1078		1280
1079	# cygwin requires the fh mode to be matching, unix doesn't	1281	# cygwin requires the fh mode to be matching, unix doesn't
1080	my ($rw, $mode) = $poll eq "r" ? ($r, "<")	1282	my ($rw, $mode) = $poll eq "r" ? ($r, "<&") : ($w, ">&");
1081	: $poll eq "w" ? ($w, ">")
1082	: Carp::croak "AnyEvent->io requires poll set to either 'r' or 'w'";
1083		1283
1084	open my $fh2, "$mode&" . fileno $fh	1284	open my $fh2, $mode, $fh
1085	or die "cannot dup() filehandle: $!,";	1285	or die "AnyEvent->io: cannot dup() filehandle in mode '$poll': $!,";
1086		1286
1087	# we assume CLOEXEC is already set by perl in all important cases	1287	# we assume CLOEXEC is already set by perl in all important cases
1088		1288
1089	($fh2, $rw)	1289	($fh2, $rw)
1090	}	1290	}
1091		1291
		1292	#############################################################################
		1293	# "new" API, currently only emulation of it
		1294	#############################################################################
		1295
		1296	package AE;
		1297
		1298	our $VERSION = $AnyEvent::VERSION;
		1299
		1300	sub io($$$) {
		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
1092	package AnyEvent::Base;	1336	package AnyEvent::Base;
1093		1337
1094	# default implementations for many methods	1338	# default implementations for many methods
1095		1339
1096	BEGIN {	1340	sub _time {
		1341	# probe for availability of Time::HiRes
1097	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;
1098	*_time = \&Time::HiRes::time;	1344	*_time = \&Time::HiRes::time;
1099	# if (eval "use POSIX (); (POSIX::times())...	1345	# if (eval "use POSIX (); (POSIX::times())...
1100	} else {	1346	} else {
		1347	warn "AnyEvent: using built-in time(), WARNING, no sub-second resolution!\n" if $VERBOSE;
1101	*_time = sub { time }; # epic fail	1348	*_time = sub { time }; # epic fail
1102	}	1349	}
		1350
		1351	&_time
1103	}	1352	}
1104		1353
1105	sub time { _time }	1354	sub time { _time }
1106	sub now { _time }	1355	sub now { _time }
1107	sub now_update { }	1356	sub now_update { }
…		…
1112	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"	1361	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"
1113	}	1362	}
1114		1363
1115	# default implementation for ->signal	1364	# default implementation for ->signal
1116		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
1117	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);
1118		1379
1119	sub _signal_exec {	1380	sub _signal_exec {
		1381	$HAVE_ASYNC_INTERRUPT
		1382	? $SIGPIPE_R->drain
1120	sysread $SIGPIPE_R, my $dummy, 4;	1383	: sysread $SIGPIPE_R, my $dummy, 9;
1121		1384
1122	while (%SIG_EV) {	1385	while (%SIG_EV) {
1123	for (keys %SIG_EV) {	1386	for (keys %SIG_EV) {
1124	delete $SIG_EV{$_};	1387	delete $SIG_EV{$_};
1125	$_->() for values %{ $SIG_CB{$_} || {} };	1388	$_->() for values %{ $SIG_CB{$_} || {} };
1126	}	1389	}
1127	}	1390	}
1128	}	1391	}
1129		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
1130	sub signal {	1443	sub signal {
1131	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;
1132		1448
1133	unless ($SIGPIPE_R) {	1449	$SIGPIPE_R = new Async::Interrupt::EventPipe;
1134	require Fcntl;	1450	$SIG_IO = AE::io $SIGPIPE_R->fileno, 0, \&_signal_exec;
1135		1451
1136	if (AnyEvent::WIN32) {
1137	require AnyEvent::Util;
1138
1139	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
1140	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R) if $SIGPIPE_R;
1141	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W) if $SIGPIPE_W; # just in case
1142	} 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 {
1143	pipe $SIGPIPE_R, $SIGPIPE_W;	1464	pipe $SIGPIPE_R, $SIGPIPE_W;
1144	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;
1145	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
		1467
		1468	# not strictly required, as $^F is normally 2, but let's make sure...
		1469	fcntl $SIGPIPE_R, &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;
1146	}	1477	}
1147		1478
1148	$SIGPIPE_R	1479	*signal = sub {
1149	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";	1480	my (undef, %arg) = @_;
1150		1481
1151	# not strictly required, as $^F is normally 2, but let's make sure...
1152	fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
1153	fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
1154
1155	$SIG_IO = AnyEvent->io (fh => $SIGPIPE_R, poll => "r", cb => \&_signal_exec);
1156	}
1157
1158	my $signal = uc $arg{signal}	1482	my $signal = uc $arg{signal}
1159	or Carp::croak "required option 'signal' is missing";	1483	or Carp::croak "required option 'signal' is missing";
1160		1484
		1485	if ($HAVE_ASYNC_INTERRUPT) {
		1486	# async::interrupt
		1487
		1488	$signal = sig2num $signal;
1161	$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
1162	$SIG{$signal} ||= sub {	1505	$SIG{$signal} ||= sub {
1163	local $!;	1506	local $!;
1164	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;	1507	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;
1165	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	};
1166	};	1534	};
1167		1535	die if $@;
1168	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"	1536	&signal
1169	}
1170
1171	sub AnyEvent::Base::signal::DESTROY {
1172	my ($signal, $cb) = @{$_[0]};
1173
1174	delete $SIG_CB{$signal}{$cb};
1175
1176	$SIG{$signal} = 'DEFAULT' unless keys %{ $SIG_CB{$signal} };
1177	}	1537	}
1178		1538
1179	# default implementation for ->child	1539	# default implementation for ->child
1180		1540
1181	our %PID_CB;	1541	our %PID_CB;
1182	our $CHLD_W;	1542	our $CHLD_W;
1183	our $CHLD_DELAY_W;	1543	our $CHLD_DELAY_W;
1184	our $PID_IDLE;
1185	our $WNOHANG;	1544	our $WNOHANG;
1186		1545
1187	sub _child_wait {	1546	sub _emit_childstatus($$) {
1188	while (0 < (my $pid = waitpid -1, $WNOHANG)) {	1547	my (undef, $rpid, $rstatus) = @_;
		1548
		1549	$_->($rpid, $rstatus)
1189	$_->($pid, $?) for (values %{ $PID_CB{$pid} || {} }),	1550	for values %{ $PID_CB{$rpid} || {} },
1190	(values %{ $PID_CB{0} || {} });	1551	values %{ $PID_CB{0} || {} };
1191	}
1192
1193	undef $PID_IDLE;
1194	}	1552	}
1195		1553
1196	sub _sigchld {	1554	sub _sigchld {
1197	# make sure we deliver these changes "synchronous" with the event loop.	1555	my $pid;
1198	$CHLD_DELAY_W ||= AnyEvent->timer (after => 0, cb => sub {	1556
1199	undef $CHLD_DELAY_W;	1557	AnyEvent->_emit_childstatus ($pid, $?)
1200	&_child_wait;	1558	while ($pid = waitpid -1, $WNOHANG) > 0;
1201	});
1202	}	1559	}
1203		1560
1204	sub child {	1561	sub child {
1205	my (undef, %arg) = @_;	1562	my (undef, %arg) = @_;
1206		1563
1207	defined (my $pid = $arg{pid} + 0)	1564	defined (my $pid = $arg{pid} + 0)
1208	or Carp::croak "required option 'pid' is missing";	1565	or Carp::croak "required option 'pid' is missing";
1209		1566
1210	$PID_CB{$pid}{$arg{cb}} = $arg{cb};	1567	$PID_CB{$pid}{$arg{cb}} = $arg{cb};
1211		1568
1212	unless ($WNOHANG) {	1569	# WNOHANG is almost cetrainly 1 everywhere
		1570	$WNOHANG ||= $^O =~ /^(?:openbsd|netbsd|linux|freebsd|cygwin|MSWin32)$/
		1571	? 1
1213	$WNOHANG = eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1;	1572	: eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1;
1214	}
1215		1573
1216	unless ($CHLD_W) {	1574	unless ($CHLD_W) {
1217	$CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld);	1575	$CHLD_W = AE::signal CHLD => \&_sigchld;
1218	# child could be a zombie already, so make at least one round	1576	# child could be a zombie already, so make at least one round
1219	&_sigchld;	1577	&_sigchld;
1220	}	1578	}
1221		1579
1222	bless [$pid, $arg{cb}], "AnyEvent::Base::child"	1580	bless [$pid, $arg{cb}], "AnyEvent::Base::child"
…		…
1230		1588
1231	undef $CHLD_W unless keys %PID_CB;	1589	undef $CHLD_W unless keys %PID_CB;
1232	}	1590	}
1233		1591
1234	# idle emulation is done by simply using a timer, regardless	1592	# idle emulation is done by simply using a timer, regardless
1235	# of whether the proces sis idle or not, and not letting	1593	# of whether the process is idle or not, and not letting
1236	# the callback use more than 50% of the time.	1594	# the callback use more than 50% of the time.
1237	sub idle {	1595	sub idle {
1238	my (undef, %arg) = @_;	1596	my (undef, %arg) = @_;
1239		1597
1240	my ($cb, $w, $rcb) = $arg{cb};	1598	my ($cb, $w, $rcb) = $arg{cb};
…		…
1248	# 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,
1249	# within some limits	1607	# within some limits
1250	$w = 0.0001 if $w < 0.0001;	1608	$w = 0.0001 if $w < 0.0001;
1251	$w = 5 if $w > 5;	1609	$w = 5 if $w > 5;
1252		1610
1253	$w = AnyEvent->timer (after => $w, cb => $rcb);	1611	$w = AE::timer $w, 0, $rcb;
1254	} else {	1612	} else {
1255	# clean up...	1613	# clean up...
1256	undef $w;	1614	undef $w;
1257	undef $rcb;	1615	undef $rcb;
1258	}	1616	}
1259	};	1617	};
1260		1618
1261	$w = AnyEvent->timer (after => 0.05, cb => $rcb);	1619	$w = AE::timer 0.05, 0, $rcb;
1262		1620
1263	bless \\$cb, "AnyEvent::Base::idle"	1621	bless \\$cb, "AnyEvent::Base::idle"
1264	}	1622	}
1265		1623
1266	sub AnyEvent::Base::idle::DESTROY {	1624	sub AnyEvent::Base::idle::DESTROY {
…		…
1271		1629
1272	our @ISA = AnyEvent::CondVar::Base::;	1630	our @ISA = AnyEvent::CondVar::Base::;
1273		1631
1274	package AnyEvent::CondVar::Base;	1632	package AnyEvent::CondVar::Base;
1275		1633
1276	use overload	1634	#use overload
1277	'&{}' => sub { my $self = shift; sub { $self->send (@_) } },	1635	# '&{}' => sub { my $self = shift; sub { $self->send (@_) } },
1278	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;
1279		1645
1280	sub _send {	1646	sub _send {
1281	# nop	1647	# nop
1282	}	1648	}
1283		1649
…		…
1296	sub ready {	1662	sub ready {
1297	$_[0]{_ae_sent}	1663	$_[0]{_ae_sent}
1298	}	1664	}
1299		1665
1300	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 $WAITING = 1;
1301	AnyEvent->one_event while !$_[0]{_ae_sent};	1672	AnyEvent->one_event while !$_[0]{_ae_sent};
1302	}	1673	}
1303		1674
1304	sub recv {	1675	sub recv {
1305	$_[0]->_wait;	1676	$_[0]->_wait;
…		…
1307	Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak};	1678	Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak};
1308	wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0]	1679	wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0]
1309	}	1680	}
1310		1681
1311	sub cb {	1682	sub cb {
1312	$_[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
1313	$_[0]{_ae_cb}	1690	$cv->{_ae_cb}
1314	}	1691	}
1315		1692
1316	sub begin {	1693	sub begin {
1317	++$_[0]{_ae_counter};	1694	++$_[0]{_ae_counter};
1318	$_[0]{_ae_end_cb} = $_[1] if @_ > 1;	1695	$_[0]{_ae_end_cb} = $_[1] if @_ > 1;
…		…
1346	so on.	1723	so on.
1347		1724
1348	=head1 ENVIRONMENT VARIABLES	1725	=head1 ENVIRONMENT VARIABLES
1349		1726
1350	The following environment variables are used by this module or its	1727	The following environment variables are used by this module or its
1351	submodules:	1728	submodules.
		1729
		1730	Note that AnyEvent will remove I<all> environment variables starting with
		1731	C<PERL_ANYEVENT_> from C<%ENV> when it is loaded while taint mode is
		1732	enabled.
1352		1733
1353	=over 4	1734	=over 4
1354		1735
1355	=item C<PERL_ANYEVENT_VERBOSE>	1736	=item C<PERL_ANYEVENT_VERBOSE>
1356		1737
…		…
1363	C<PERL_ANYEVENT_MODEL>.	1744	C<PERL_ANYEVENT_MODEL>.
1364		1745
1365	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
1366	model it chooses.	1747	model it chooses.
1367		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
1368	=item C<PERL_ANYEVENT_STRICT>	1752	=item C<PERL_ANYEVENT_STRICT>
1369		1753
1370	AnyEvent does not do much argument checking by default, as thorough	1754	AnyEvent does not do much argument checking by default, as thorough
1371	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
1372	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
1373	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,
1374	it will croak.	1758	it will croak.
1375		1759
1376	In other words, enables "strict" mode.	1760	In other words, enables "strict" mode.
1377		1761
1378	Unlike C<use strict>, it is definitely recommended ot keep it off in	1762	Unlike C<use strict> (or it's modern cousin, C<< use L<common::sense>
1379	production. Keeping C<PERL_ANYEVENT_STRICT=1> in your environment while	1763	>>, it is definitely recommended to keep it off in production. Keeping
1380	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.
1381		1766
1382	=item C<PERL_ANYEVENT_MODEL>	1767	=item C<PERL_ANYEVENT_MODEL>
1383		1768
1384	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
1385	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
…		…
1428		1813
1429	=item C<PERL_ANYEVENT_MAX_FORKS>	1814	=item C<PERL_ANYEVENT_MAX_FORKS>
1430		1815
1431	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>
1432	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.
1433		1842
1434	=back	1843	=back
1435		1844
1436	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE	1845	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE
1437		1846
…		…
1682	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
1683	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
1684	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
1685	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
1686	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
1687	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
1688	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
1689	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
1690	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
1691		2102
…		…
1720	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
1721	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.
1722		2133
1723	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
1724	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.
1725		2139
1726	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
1727	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
1728	C<Event>. However, Glib scales extremely badly, doubling the number of	2142	C<Event>. However, Glib scales extremely badly, doubling the number of
1729	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,
…		…
1807	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
1808	a new one that moves the timeout into the future.	2222	a new one that moves the timeout into the future.
1809		2223
1810	=head3 Results	2224	=head3 Results
1811		2225
1812	name sockets create request	2226	name sockets create request
1813	EV 20000 69.01 11.16	2227	EV 20000 69.01 11.16
1814	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
1815	Event 20000 212.62 257.32	2231	Event 20000 212.62 257.32
1816	Glib 20000 651.16 1896.30	2232	Glib 20000 651.16 1896.30
1817	POE 20000 349.67 12317.24 uses POE::Loop::Event	2233	POE 20000 349.67 12317.24 uses POE::Loop::Event
1818		2234
1819	=head3 Discussion	2235	=head3 Discussion
1820		2236
1821	This benchmark I<does> measure scalability and overall performance of the	2237	This benchmark I<does> measure scalability and overall performance of the
1822	particular event loop.	2238	particular event loop.
…		…
1824	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
1825	is relatively high, though.	2241	is relatively high, though.
1826		2242
1827	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
1828	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.
1829		2248
1830	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
1831	understand why). Callback invocation also has a high overhead compared to	2250	understand why). Callback invocation also has a high overhead compared to
1832	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
1833	uses select or poll in basically all documented configurations.	2252	uses select or poll in basically all documented configurations.
…		…
1896	=item * C-based event loops perform very well with small number of	2315	=item * C-based event loops perform very well with small number of
1897	watchers, as the management overhead dominates.	2316	watchers, as the management overhead dominates.
1898		2317
1899	=back	2318	=back
1900		2319
		2320	=head2 THE IO::Lambda BENCHMARK
		2321
		2322	Recently I was told about the benchmark in the IO::Lambda manpage, which
		2323	could be misinterpreted to make AnyEvent look bad. In fact, the benchmark
		2324	simply compares IO::Lambda with POE, and IO::Lambda looks better (which
		2325	shouldn't come as a surprise to anybody). As such, the benchmark is
		2326	fine, and mostly shows that the AnyEvent backend from IO::Lambda isn't
		2327	very optimal. But how would AnyEvent compare when used without the extra
		2328	baggage? To explore this, I wrote the equivalent benchmark for AnyEvent.
		2329
		2330	The benchmark itself creates an echo-server, and then, for 500 times,
		2331	connects to the echo server, sends a line, waits for the reply, and then
		2332	creates the next connection. This is a rather bad benchmark, as it doesn't
		2333	test the efficiency of the framework or much non-blocking I/O, but it is a
		2334	benchmark nevertheless.
		2335
		2336	name runtime
		2337	Lambda/select 0.330 sec
		2338	+ optimized 0.122 sec
		2339	Lambda/AnyEvent 0.327 sec
		2340	+ optimized 0.138 sec
		2341	Raw sockets/select 0.077 sec
		2342	POE/select, components 0.662 sec
		2343	POE/select, raw sockets 0.226 sec
		2344	POE/select, optimized 0.404 sec
		2345
		2346	AnyEvent/select/nb 0.085 sec
		2347	AnyEvent/EV/nb 0.068 sec
		2348	+state machine 0.134 sec
		2349
		2350	The benchmark is also a bit unfair (my fault): the IO::Lambda/POE
		2351	benchmarks actually make blocking connects and use 100% blocking I/O,
		2352	defeating the purpose of an event-based solution. All of the newly
		2353	written AnyEvent benchmarks use 100% non-blocking connects (using
		2354	AnyEvent::Socket::tcp_connect and the asynchronous pure perl DNS
		2355	resolver), so AnyEvent is at a disadvantage here, as non-blocking connects
		2356	generally require a lot more bookkeeping and event handling than blocking
		2357	connects (which involve a single syscall only).
		2358
		2359	The last AnyEvent benchmark additionally uses L<AnyEvent::Handle>, which
		2360	offers similar expressive power as POE and IO::Lambda, using conventional
		2361	Perl syntax. This means that both the echo server and the client are 100%
		2362	non-blocking, further placing it at a disadvantage.
		2363
		2364	As you can see, the AnyEvent + EV combination even beats the
		2365	hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl
		2366	backend easily beats IO::Lambda and POE.
		2367
		2368	And even the 100% non-blocking version written using the high-level (and
		2369	slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda by a
		2370	large margin, even though it does all of DNS, tcp-connect and socket I/O
		2371	in a non-blocking way.
		2372
		2373	The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and
		2374	F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are
		2375	part of the IO::lambda distribution and were used without any changes.
		2376
1901		2377
1902	=head1 SIGNALS	2378	=head1 SIGNALS
1903		2379
1904	AnyEvent currently installs handlers for these signals:	2380	AnyEvent currently installs handlers for these signals:
1905		2381
…		…
1908	=item SIGCHLD	2384	=item SIGCHLD
1909		2385
1910	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
1911	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
1912	event loops install a similar handler.	2388	event loops install a similar handler.
		2389
		2390	Additionally, when AnyEvent is loaded and SIGCHLD is set to IGNORE, then
		2391	AnyEvent will reset it to default, to avoid losing child exit statuses.
1913		2392
1914	=item SIGPIPE	2393	=item SIGPIPE
1915		2394
1916	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>
1917	when AnyEvent gets loaded.	2396	when AnyEvent gets loaded.
…		…
1929		2408
1930	=back	2409	=back
1931		2410
1932	=cut	2411	=cut
1933		2412
		2413	undef $SIG{CHLD}
		2414	if $SIG{CHLD} eq 'IGNORE';
		2415
1934	$SIG{PIPE} = sub { }	2416	$SIG{PIPE} = sub { }
1935	unless defined $SIG{PIPE};	2417	unless defined $SIG{PIPE};
		2418
		2419	=head1 RECOMMENDED/OPTIONAL MODULES
		2420
		2421	One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and
		2422	it's built-in modules) are required to use it.
		2423
		2424	That does not mean that AnyEvent won't take advantage of some additional
		2425	modules if they are installed.
		2426
		2427	This section epxlains which additional modules will be used, and how they
		2428	affect AnyEvent's operetion.
		2429
		2430	=over 4
		2431
		2432	=item L<Async::Interrupt>
		2433
		2434	This slightly arcane module is used to implement fast signal handling: To
		2435	my knowledge, there is no way to do completely race-free and quick
		2436	signal handling in pure perl. To ensure that signals still get
		2437	delivered, AnyEvent will start an interval timer to wake up perl (and
		2438	catch the signals) with some delay (default is 10 seconds, look for
		2439	C<$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
1936		2495
1937		2496
1938	=head1 FORK	2497	=head1 FORK
1939		2498
1940	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
1941	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>
1942	calls. Only L<EV> is fully fork-aware.	2501	calls. Only L<EV> is fully fork-aware.
1943		2502
1944	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
1945	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.
1946		2506
1947		2507
1948	=head1 SECURITY CONSIDERATIONS	2508	=head1 SECURITY CONSIDERATIONS
1949		2509
1950	AnyEvent can be forced to load any event model via	2510	AnyEvent can be forced to load any event model via
…		…
1962	use AnyEvent;	2522	use AnyEvent;
1963		2523
1964	Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can	2524	Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can
1965	be used to probe what backend is used and gain other information (which is	2525	be used to probe what backend is used and gain other information (which is
1966	probably even less useful to an attacker than PERL_ANYEVENT_MODEL), and	2526	probably even less useful to an attacker than PERL_ANYEVENT_MODEL), and
1967	$ENV{PERL_ANYEGENT_STRICT}.	2527	$ENV{PERL_ANYEVENT_STRICT}.
		2528
		2529	Note that AnyEvent will remove I<all> environment variables starting with
		2530	C<PERL_ANYEVENT_> from C<%ENV> when it is loaded while taint mode is
		2531	enabled.
1968		2532
1969		2533
1970	=head1 BUGS	2534	=head1 BUGS
1971		2535
1972	Perl 5.8 has numerous memleaks that sometimes hit this module and are hard	2536	Perl 5.8 has numerous memleaks that sometimes hit this module and are hard
…		…
1984	L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.	2548	L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.
1985		2549
1986	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,	2550	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,
1987	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>,
1988	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,	2552	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,
1989	L<AnyEvent::Impl::POE>.	2553	L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>, L<Anyevent::Impl::Irssi>.
1990		2554
1991	Non-blocking file handles, sockets, TCP clients and	2555	Non-blocking file handles, sockets, TCP clients and
1992	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>.	2556	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.
1993		2557
1994	Asynchronous DNS: L<AnyEvent::DNS>.	2558	Asynchronous DNS: L<AnyEvent::DNS>.
1995		2559
1996	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>,
1997		2562
1998	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>.
1999		2565
2000		2566
2001	=head1 AUTHOR	2567	=head1 AUTHOR
2002		2568
2003	Marc Lehmann <schmorp@schmorp.de>	2569	Marc Lehmann <schmorp@schmorp.de>

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