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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 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
…		…
392		441
393	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
394	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
395	have exited already (and no SIGCHLD will be sent anymore).	444	have exited already (and no SIGCHLD will be sent anymore).
396		445
397	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
398	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
399	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.
400		452
401	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
402	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
403	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.
404		461
405	Example: fork a process and wait for it	462	Example: fork a process and wait for it
406		463
407	my $done = AnyEvent->condvar;	464	my $done = AnyEvent->condvar;
408		465
…		…
420	# do something else, then wait for process exit	477	# do something else, then wait for process exit
421	$done->recv;	478	$done->recv;
422		479
423	=head2 IDLE WATCHERS	480	=head2 IDLE WATCHERS
424		481
		482	$w = AnyEvent->idle (cb => <callback>);
		483
425	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
426	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
427	"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
428	attention by the event loop".	487	attention by the event loop".
429		488
…		…
455	});	514	});
456	});	515	});
457		516
458	=head2 CONDITION VARIABLES	517	=head2 CONDITION VARIABLES
459		518
		519	$cv = AnyEvent->condvar;
		520
		521	$cv->send (<list>);
		522	my @res = $cv->recv;
		523
460	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
461	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
462	will actively watch for new events and call your callbacks.	526	will actively watch for new events and call your callbacks.
463		527
464	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
465	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).
466		530
467	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
468	because they represent a condition that must become true.	532	because they represent a condition that must become true.
469		533
		534	Now is probably a good time to look at the examples further below.
		535
470	Condition variables can be created by calling the C<< AnyEvent->condvar	536	Condition variables can be created by calling the C<< AnyEvent->condvar
471	>> method, usually without arguments. The only argument pair allowed is	537	>> method, usually without arguments. The only argument pair allowed is
472
473	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
474	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
475	the results).	540	the results).
476		541
477	After creation, the condition variable is "false" until it becomes "true"	542	After creation, the condition variable is "false" until it becomes "true"
…		…
482	Condition variables are similar to callbacks, except that you can	547	Condition variables are similar to callbacks, except that you can
483	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
484	in time where multiple outstanding events have been processed. And yet	549	in time where multiple outstanding events have been processed. And yet
485	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
486	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
487	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.
488		554
489	Condition variables are very useful to signal that something has finished,	555	Condition variables are very useful to signal that something has finished,
490	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,
491	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
492	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
…		…
526	after => 1,	592	after => 1,
527	cb => sub { $result_ready->send },	593	cb => sub { $result_ready->send },
528	);	594	);
529		595
530	# this "blocks" (while handling events) till the callback	596	# this "blocks" (while handling events) till the callback
531	# calls send	597	# calls -<send
532	$result_ready->recv;	598	$result_ready->recv;
533		599
534	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
535	condition variables are also code references.	601	variables are also callable directly.
536		602
537	my $done = AnyEvent->condvar;	603	my $done = AnyEvent->condvar;
538	my $delay = AnyEvent->timer (after => 5, cb => $done);	604	my $delay = AnyEvent->timer (after => 5, cb => $done);
539	$done->recv;	605	$done->recv;
540		606
…		…
546		612
547	...	613	...
548		614
549	my @info = $couchdb->info->recv;	615	my @info = $couchdb->info->recv;
550		616
551	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
552	results are available:	618	results are available:
553		619
554	$couchdb->info->cb (sub {	620	$couchdb->info->cb (sub {
555	my @info = $_[0]->recv;	621	my @info = $_[0]->recv;
556	});	622	});
…		…
574	immediately from within send.	640	immediately from within send.
575		641
576	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
577	future C<< ->recv >> calls.	643	future C<< ->recv >> calls.
578		644
579	Condition variables are overloaded so one can call them directly	645	Condition variables are overloaded so one can call them directly (as if
580	(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
581	C<send>. Note, however, that many C-based event loops do not handle	647	C<send>.
582	overloading, so as tempting as it may be, passing a condition variable
583	instead of a callback does not work. Both the pure perl and EV loops
584	support overloading, however, as well as all functions that use perl to
585	invoke a callback (as in L<AnyEvent::Socket> and L<AnyEvent::DNS> for
586	example).
587		648
588	=item $cv->croak ($error)	649	=item $cv->croak ($error)
589		650
590	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
591	C<Carp::croak> with the given error message/object/scalar.	652	C<Carp::croak> with the given error message/object/scalar.
592		653
593	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
594	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.
595		660
596	=item $cv->begin ([group callback])	661	=item $cv->begin ([group callback])
597		662
598	=item $cv->end	663	=item $cv->end
599
600	These two methods are EXPERIMENTAL and MIGHT CHANGE.
601		664
602	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
603	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
604	to use a condition variable for the whole process.	667	to use a condition variable for the whole process.
605		668
…		…
607	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
608	>>, 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
609	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
610	callback was set, C<send> will be called without any arguments.	673	callback was set, C<send> will be called without any arguments.
611		674
612	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:
613		706
614	my $cv = AnyEvent->condvar;	707	my $cv = AnyEvent->condvar;
615		708
616	my %result;	709	my %result;
617	$cv->begin (sub { $cv->send (\%result) });	710	$cv->begin (sub { $cv->send (\%result) });
…		…
637	loop, which serves two important purposes: first, it sets the callback	730	loop, which serves two important purposes: first, it sets the callback
638	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
639	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
640	doesn't execute once).	733	doesn't execute once).
641		734
642	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
643	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
644	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
645	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>.
646		740
647	=back	741	=back
648		742
649	=head3 METHODS FOR CONSUMERS	743	=head3 METHODS FOR CONSUMERS
650		744
…		…
666	function will call C<croak>.	760	function will call C<croak>.
667		761
668	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,
669	in scalar context only the first one will be returned.	763	in scalar context only the first one will be returned.
670		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
671	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
672	(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
673	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
674	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
675	condition variables with some kind of request results and supporting	776	condition variables with some kind of request results and supporting
676	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,
677	while still supporting blocking waits if the caller so desires).	778	while still supporting blocking waits if the caller so desires).
678		779
679	Another reason I<never> to C<< ->recv >> in a module is that you cannot
680	sensibly have two C<< ->recv >>'s in parallel, as that would require
681	multiple interpreters or coroutines/threads, none of which C<AnyEvent>
682	can supply.
683
684	The L<Coro> module, however, I<can> and I<does> supply coroutines and, in
685	fact, L<Coro::AnyEvent> replaces AnyEvent's condvars by coroutine-safe
686	versions and also integrates coroutines into AnyEvent, making blocking
687	C<< ->recv >> calls perfectly safe as long as they are done from another
688	coroutine (one that doesn't run the event loop).
689
690	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
691	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
692	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
693	waits otherwise.	783	waits otherwise.
694		784
…		…
700	=item $cb = $cv->cb ($cb->($cv))	790	=item $cb = $cv->cb ($cb->($cv))
701		791
702	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
703	replaces it before doing so.	793	replaces it before doing so.
704		794
705	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)
706	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
707	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>
708	is guaranteed not to block.	798	inside the callback or at any later time is guaranteed not to block.
709		799
710	=back	800	=back
711		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
712	=head1 GLOBAL VARIABLES AND FUNCTIONS	870	=head1 GLOBAL VARIABLES AND FUNCTIONS
713		871
		872	These are not normally required to use AnyEvent, but can be useful to
		873	write AnyEvent extension modules.
		874
714	=over 4	875	=over 4
715		876
716	=item $AnyEvent::MODEL	877	=item $AnyEvent::MODEL
717		878
718	Contains C<undef> until the first watcher is being created. Then it	879	Contains C<undef> until the first watcher is being created, before the
		880	backend has been autodetected.
		881
719	contains the event model that is being used, which is the name of the	882	Afterwards it contains the event model that is being used, which is the
720	Perl class implementing the model. This class is usually one of the	883	name of the Perl class implementing the model. This class is usually one
721	C<AnyEvent::Impl:xxx> modules, but can be any other class in the case	884	of the C<AnyEvent::Impl:xxx> modules, but can be any other class in the
722	AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode>).	885	case AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode> it
723		886	will be C<urxvt::anyevent>).
724	The known classes so far are:
725
726	AnyEvent::Impl::EV based on EV (an interface to libev, best choice).
727	AnyEvent::Impl::Event based on Event, second best choice.
728	AnyEvent::Impl::Perl pure-perl implementation, fast and portable.
729	AnyEvent::Impl::Glib based on Glib, third-best choice.
730	AnyEvent::Impl::Tk based on Tk, very bad choice.
731	AnyEvent::Impl::Qt based on Qt, cannot be autoprobed (see its docs).
732	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
733	AnyEvent::Impl::POE based on POE, not generic enough for full support.
734
735	There is no support for WxWidgets, as WxWidgets has no support for
736	watching file handles. However, you can use WxWidgets through the
737	POE Adaptor, as POE has a Wx backend that simply polls 20 times per
738	second, which was considered to be too horrible to even consider for
739	AnyEvent. Likewise, other POE backends can be used by AnyEvent by using
740	it's adaptor.
741
742	AnyEvent knows about L<Prima> and L<Wx> and will try to use L<POE> when
743	autodetecting them.
744		887
745	=item AnyEvent::detect	888	=item AnyEvent::detect
746		889
747	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model	890	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model
748	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
749	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
750	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>.
751		897
752	=item $guard = AnyEvent::post_detect { BLOCK }	898	=item $guard = AnyEvent::post_detect { BLOCK }
753		899
754	Arranges for the code block to be executed as soon as the event model is	900	Arranges for the code block to be executed as soon as the event model is
755	autodetected (or immediately if this has already happened).	901	autodetected (or immediately if this has already happened).
756		902
		903	The block will be executed I<after> the actual backend has been detected
		904	(C<$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
757	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
758	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
759	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 ||= $guard;
760		934
761	=item @AnyEvent::post_detect	935	=item @AnyEvent::post_detect
762		936
763	If there are any code references in this array (you can C<push> to it	937	If there are any code references in this array (you can C<push> to it
764	before or after loading AnyEvent), then they will called directly after	938	before or after loading AnyEvent), then they will called directly after
765	the event loop has been chosen.	939	the event loop has been chosen.
766		940
767	You should check C<$AnyEvent::MODEL> before adding to this array, though:	941	You should check C<$AnyEvent::MODEL> before adding to this array, though:
768	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
769	and the array will be ignored.	943	array will be ignored.
770		944
771	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.
772		952
773	=back	953	=back
774		954
775	=head1 WHAT TO DO IN A MODULE	955	=head1 WHAT TO DO IN A MODULE
776		956
…		…
831		1011
832		1012
833	=head1 OTHER MODULES	1013	=head1 OTHER MODULES
834		1014
835	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
836	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
837	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
838	available via CPAN.	1018	come with AnyEvent, most are available via CPAN.
839		1019
840	=over 4	1020	=over 4
841		1021
842	=item L<AnyEvent::Util>	1022	=item L<AnyEvent::Util>
843		1023
…		…
852		1032
853	=item L<AnyEvent::Handle>	1033	=item L<AnyEvent::Handle>
854		1034
855	Provide read and write buffers, manages watchers for reads and writes,	1035	Provide read and write buffers, manages watchers for reads and writes,
856	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
857	non-blocking SSL/TLS.	1037	non-blocking SSL/TLS (via L<AnyEvent::TLS>.
858		1038
859	=item L<AnyEvent::DNS>	1039	=item L<AnyEvent::DNS>
860		1040
861	Provides rich asynchronous DNS resolver capabilities.	1041	Provides rich asynchronous DNS resolver capabilities.
862		1042
…		…
890		1070
891	=item L<AnyEvent::GPSD>	1071	=item L<AnyEvent::GPSD>
892		1072
893	A non-blocking interface to gpsd, a daemon delivering GPS information.	1073	A non-blocking interface to gpsd, a daemon delivering GPS information.
894		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
895	=item L<AnyEvent::IGS>	1084	=item L<AnyEvent::IGS>
896		1085
897	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
898	L<App::IGS>).	1087	L<App::IGS>).
899		1088
900	=item L<AnyEvent::IRC>
901
902	AnyEvent based IRC client module family (replacing the older Net::IRC3).
903
904	=item L<Net::XMPP2>
905
906	AnyEvent based XMPP (Jabber protocol) module family.
907
908	=item L<Net::FCP>	1089	=item L<Net::FCP>
909		1090
910	AnyEvent-based implementation of the Freenet Client Protocol, birthplace	1091	AnyEvent-based implementation of the Freenet Client Protocol, birthplace
911	of AnyEvent.	1092	of AnyEvent.
912		1093
…		…
916		1097
917	=item L<Coro>	1098	=item L<Coro>
918		1099
919	Has special support for AnyEvent via L<Coro::AnyEvent>.	1100	Has special support for AnyEvent via L<Coro::AnyEvent>.
920		1101
921	=item L<IO::Lambda>
922
923	The lambda approach to I/O - don't ask, look there. Can use AnyEvent.
924
925	=back	1102	=back
926		1103
927	=cut	1104	=cut
928		1105
929	package AnyEvent;	1106	package AnyEvent;
930		1107
		1108	# basically a tuned-down version of common::sense
		1109	sub common_sense {
931	no warnings;	1110	# no warnings
		1111	${^WARNING_BITS} ^= ${^WARNING_BITS};
932	use strict qw(vars subs);	1112	# use strict vars subs
		1113	$^H |= 0x00000600;
		1114	}
933		1115
		1116	BEGIN { AnyEvent::common_sense }
		1117
934	use Carp;	1118	use Carp ();
935		1119
936	our $VERSION = 4.411;	1120	our $VERSION = '5.0';
937	our $MODEL;	1121	our $MODEL;
938		1122
939	our $AUTOLOAD;	1123	our $AUTOLOAD;
940	our @ISA;	1124	our @ISA;
941		1125
942	our @REGISTRY;	1126	our @REGISTRY;
943		1127
944	our $WIN32;	1128	our $WIN32;
		1129
		1130	our $VERBOSE;
945		1131
946	BEGIN {	1132	BEGIN {
947	eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }";	1133	eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }";
948	eval "sub TAINT(){ " . (${^TAINT}*1) . " }";	1134	eval "sub TAINT(){ " . (${^TAINT}*1) . " }";
949		1135
950	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}	1136	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}
951	if ${^TAINT};	1137	if ${^TAINT};
952	}
953		1138
954	our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1;	1139	$VERBOSE = $ENV{PERL_ANYEVENT_VERBOSE}*1;
		1140
		1141	}
		1142
		1143	our $MAX_SIGNAL_LATENCY = 10;
955		1144
956	our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred	1145	our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred
957		1146
958	{	1147	{
959	my $idx;	1148	my $idx;
…		…
961	for reverse split /\s*,\s*/,	1150	for reverse split /\s*,\s*/,
962	$ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";	1151	$ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";
963	}	1152	}
964		1153
965	my @models = (	1154	my @models = (
966	[EV:: => AnyEvent::Impl::EV::],	1155	[EV:: => AnyEvent::Impl::EV:: , 1],
967	[Event:: => AnyEvent::Impl::Event::],
968	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::],	1156	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl:: , 1],
969	# everything below here will not be autoprobed	1157	# everything below here will not (normally) be autoprobed
970	# as the pureperl backend should work everywhere	1158	# as the pureperl backend should work everywhere
971	# 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
972	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles	1164	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
973	[Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers
974	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
975	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program	1165	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program
976	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza	1166	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
977	[Wx:: => AnyEvent::Impl::POE::],	1167	[Wx:: => AnyEvent::Impl::POE::],
978	[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	[IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program
		1174	[IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program
		1175	[IO::Async::Notifier:: => AnyEvent::Impl::IOAsync::], # requires special main program
		1176	[AnyEvent::Impl::IOAsync:: => AnyEvent::Impl::IOAsync::], # requires special main program
979	);	1177	);
980		1178
981	our %method = map +($_ => 1),	1179	our %method = map +($_ => 1),
982	qw(io timer time now now_update signal child idle condvar one_event DESTROY);	1180	qw(io timer time now now_update signal child idle condvar one_event DESTROY);
983		1181
…		…
987	my ($cb) = @_;	1185	my ($cb) = @_;
988		1186
989	if ($MODEL) {	1187	if ($MODEL) {
990	$cb->();	1188	$cb->();
991		1189
992	1	1190	undef
993	} else {	1191	} else {
994	push @post_detect, $cb;	1192	push @post_detect, $cb;
995		1193
996	defined wantarray	1194	defined wantarray
997	? bless \$cb, "AnyEvent::Util::postdetect"	1195	? bless \$cb, "AnyEvent::Util::postdetect"
…		…
1003	@post_detect = grep $_ != ${$_[0]}, @post_detect;	1201	@post_detect = grep $_ != ${$_[0]}, @post_detect;
1004	}	1202	}
1005		1203
1006	sub detect() {	1204	sub detect() {
1007	unless ($MODEL) {	1205	unless ($MODEL) {
1008	no strict 'refs';
1009	local $SIG{__DIE__};	1206	local $SIG{__DIE__};
1010		1207
1011	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {	1208	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {
1012	my $model = "AnyEvent::Impl::$1";	1209	my $model = "AnyEvent::Impl::$1";
1013	if (eval "require $model") {	1210	if (eval "require $model") {
1014	$MODEL = $model;	1211	$MODEL = $model;
1015	warn "AnyEvent: loaded model '$model' (forced by \$PERL_ANYEVENT_MODEL), using it.\n" if $verbose > 1;	1212	warn "AnyEvent: loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.\n" if $VERBOSE >= 2;
1016	} else {	1213	} else {
1017	warn "AnyEvent: unable to load model '$model' (from \$PERL_ANYEVENT_MODEL):\n$@" if $verbose;	1214	warn "AnyEvent: unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@" if $VERBOSE;
1018	}	1215	}
1019	}	1216	}
1020		1217
1021	# check for already loaded models	1218	# check for already loaded models
1022	unless ($MODEL) {	1219	unless ($MODEL) {
1023	for (@REGISTRY, @models) {	1220	for (@REGISTRY, @models) {
1024	my ($package, $model) = @$_;	1221	my ($package, $model) = @$_;
1025	if (${"$package\::VERSION"} > 0) {	1222	if (${"$package\::VERSION"} > 0) {
1026	if (eval "require $model") {	1223	if (eval "require $model") {
1027	$MODEL = $model;	1224	$MODEL = $model;
1028	warn "AnyEvent: autodetected model '$model', using it.\n" if $verbose > 1;	1225	warn "AnyEvent: autodetected model '$model', using it.\n" if $VERBOSE >= 2;
1029	last;	1226	last;
1030	}	1227	}
1031	}	1228	}
1032	}	1229	}
1033		1230
1034	unless ($MODEL) {	1231	unless ($MODEL) {
1035	# try to load a model	1232	# try to autoload a model
1036
1037	for (@REGISTRY, @models) {	1233	for (@REGISTRY, @models) {
1038	my ($package, $model) = @$_;	1234	my ($package, $model, $autoload) = @$_;
		1235	if (
		1236	$autoload
1039	if (eval "require $package"	1237	and eval "require $package"
1040	and ${"$package\::VERSION"} > 0	1238	and ${"$package\::VERSION"} > 0
1041	and eval "require $model") {	1239	and eval "require $model"
		1240	) {
1042	$MODEL = $model;	1241	$MODEL = $model;
1043	warn "AnyEvent: autoprobed model '$model', using it.\n" if $verbose > 1;	1242	warn "AnyEvent: autoloaded model '$model', using it.\n" if $VERBOSE >= 2;
1044	last;	1243	last;
1045	}	1244	}
1046	}	1245	}
1047		1246
1048	$MODEL	1247	$MODEL
…		…
1064		1263
1065	sub AUTOLOAD {	1264	sub AUTOLOAD {
1066	(my $func = $AUTOLOAD) =~ s/.*://;	1265	(my $func = $AUTOLOAD) =~ s/.*://;
1067		1266
1068	$method{$func}	1267	$method{$func}
1069	or croak "$func: not a valid method for AnyEvent objects";	1268	or Carp::croak "$func: not a valid method for AnyEvent objects";
1070		1269
1071	detect unless $MODEL;	1270	detect unless $MODEL;
1072		1271
1073	my $class = shift;	1272	my $class = shift;
1074	$class->$func (@_);	1273	$class->$func (@_);
1075	}	1274	}
1076		1275
1077	# utility function to dup a filehandle. this is used by many backends	1276	# utility function to dup a filehandle. this is used by many backends
1078	# to support binding more than one watcher per filehandle (they usually	1277	# to support binding more than one watcher per filehandle (they usually
1079	# allow only one watcher per fd, so we dup it to get a different one).	1278	# allow only one watcher per fd, so we dup it to get a different one).
1080	sub _dupfh($$$$) {	1279	sub _dupfh($$;$$) {
1081	my ($poll, $fh, $r, $w) = @_;	1280	my ($poll, $fh, $r, $w) = @_;
1082		1281
1083	# cygwin requires the fh mode to be matching, unix doesn't	1282	# cygwin requires the fh mode to be matching, unix doesn't
1084	my ($rw, $mode) = $poll eq "r" ? ($r, "<")	1283	my ($rw, $mode) = $poll eq "r" ? ($r, "<&") : ($w, ">&");
1085	: $poll eq "w" ? ($w, ">")
1086	: Carp::croak "AnyEvent->io requires poll set to either 'r' or 'w'";
1087		1284
1088	open my $fh2, "$mode&" . fileno $fh	1285	open my $fh2, $mode, $fh
1089	or die "cannot dup() filehandle: $!,";	1286	or die "AnyEvent->io: cannot dup() filehandle in mode '$poll': $!,";
1090		1287
1091	# we assume CLOEXEC is already set by perl in all important cases	1288	# we assume CLOEXEC is already set by perl in all important cases
1092		1289
1093	($fh2, $rw)	1290	($fh2, $rw)
1094	}	1291	}
1095		1292
		1293	=head1 SIMPLIFIED AE API
		1294
		1295	Starting with version 5.0, AnyEvent officially supports a second, much
		1296	simpler, API that is designed to reduce the calling, typing and memory
		1297	overhead.
		1298
		1299	See the L<AE> manpage for details.
		1300
		1301	=cut
		1302
		1303	package AE;
		1304
		1305	our $VERSION = $AnyEvent::VERSION;
		1306
		1307	sub io($$$) {
		1308	AnyEvent->io (fh => $_[0], poll => $_[1] ? "w" : "r", cb => $_[2])
		1309	}
		1310
		1311	sub timer($$$) {
		1312	AnyEvent->timer (after => $_[0], interval => $_[1], cb => $_[2])
		1313	}
		1314
		1315	sub signal($$) {
		1316	AnyEvent->signal (signal => $_[0], cb => $_[1])
		1317	}
		1318
		1319	sub child($$) {
		1320	AnyEvent->child (pid => $_[0], cb => $_[1])
		1321	}
		1322
		1323	sub idle($) {
		1324	AnyEvent->idle (cb => $_[0])
		1325	}
		1326
		1327	sub cv(;&) {
		1328	AnyEvent->condvar (@_ ? (cb => $_[0]) : ())
		1329	}
		1330
		1331	sub now() {
		1332	AnyEvent->now
		1333	}
		1334
		1335	sub now_update() {
		1336	AnyEvent->now_update
		1337	}
		1338
		1339	sub time() {
		1340	AnyEvent->time
		1341	}
		1342
1096	package AnyEvent::Base;	1343	package AnyEvent::Base;
1097		1344
1098	# default implementations for many methods	1345	# default implementations for many methods
1099		1346
1100	BEGIN {	1347	sub _time {
		1348	# probe for availability of Time::HiRes
1101	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {	1349	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {
		1350	warn "AnyEvent: using Time::HiRes for sub-second timing accuracy.\n" if $VERBOSE >= 8;
1102	*_time = \&Time::HiRes::time;	1351	*_time = \&Time::HiRes::time;
1103	# if (eval "use POSIX (); (POSIX::times())...	1352	# if (eval "use POSIX (); (POSIX::times())...
1104	} else {	1353	} else {
		1354	warn "AnyEvent: using built-in time(), WARNING, no sub-second resolution!\n" if $VERBOSE;
1105	*_time = sub { time }; # epic fail	1355	*_time = sub { time }; # epic fail
1106	}	1356	}
		1357
		1358	&_time
1107	}	1359	}
1108		1360
1109	sub time { _time }	1361	sub time { _time }
1110	sub now { _time }	1362	sub now { _time }
1111	sub now_update { }	1363	sub now_update { }
…		…
1116	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"	1368	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"
1117	}	1369	}
1118		1370
1119	# default implementation for ->signal	1371	# default implementation for ->signal
1120		1372
		1373	our $HAVE_ASYNC_INTERRUPT;
		1374
		1375	sub _have_async_interrupt() {
		1376	$HAVE_ASYNC_INTERRUPT = 1*(!$ENV{PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT}
		1377	&& eval "use Async::Interrupt 1.0 (); 1")
		1378	unless defined $HAVE_ASYNC_INTERRUPT;
		1379
		1380	$HAVE_ASYNC_INTERRUPT
		1381	}
		1382
1121	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);	1383	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);
		1384	our (%SIG_ASY, %SIG_ASY_W);
		1385	our ($SIG_COUNT, $SIG_TW);
1122		1386
1123	sub _signal_exec {	1387	sub _signal_exec {
		1388	$HAVE_ASYNC_INTERRUPT
		1389	? $SIGPIPE_R->drain
1124	sysread $SIGPIPE_R, my $dummy, 4;	1390	: sysread $SIGPIPE_R, my $dummy, 9;
1125		1391
1126	while (%SIG_EV) {	1392	while (%SIG_EV) {
1127	for (keys %SIG_EV) {	1393	for (keys %SIG_EV) {
1128	delete $SIG_EV{$_};	1394	delete $SIG_EV{$_};
1129	$_->() for values %{ $SIG_CB{$_} || {} };	1395	$_->() for values %{ $SIG_CB{$_} || {} };
1130	}	1396	}
1131	}	1397	}
1132	}	1398	}
1133		1399
		1400	# install a dummy wakeup watcher to reduce signal catching latency
		1401	sub _sig_add() {
		1402	unless ($SIG_COUNT++) {
		1403	# try to align timer on a full-second boundary, if possible
		1404	my $NOW = AE::now;
		1405
		1406	$SIG_TW = AE::timer
		1407	$MAX_SIGNAL_LATENCY - ($NOW - int $NOW),
		1408	$MAX_SIGNAL_LATENCY,
		1409	sub { } # just for the PERL_ASYNC_CHECK
		1410	;
		1411	}
		1412	}
		1413
		1414	sub _sig_del {
		1415	undef $SIG_TW
		1416	unless --$SIG_COUNT;
		1417	}
		1418
		1419	our $_sig_name_init; $_sig_name_init = sub {
		1420	eval q{ # poor man's autoloading
		1421	undef $_sig_name_init;
		1422
		1423	if (_have_async_interrupt) {
		1424	*sig2num = \&Async::Interrupt::sig2num;
		1425	*sig2name = \&Async::Interrupt::sig2name;
		1426	} else {
		1427	require Config;
		1428
		1429	my %signame2num;
		1430	@signame2num{ split ' ', $Config::Config{sig_name} }
		1431	= split ' ', $Config::Config{sig_num};
		1432
		1433	my @signum2name;
		1434	@signum2name[values %signame2num] = keys %signame2num;
		1435
		1436	*sig2num = sub($) {
		1437	$_[0] > 0 ? shift : $signame2num{+shift}
		1438	};
		1439	*sig2name = sub ($) {
		1440	$_[0] > 0 ? $signum2name[+shift] : shift
		1441	};
		1442	}
		1443	};
		1444	die if $@;
		1445	};
		1446
		1447	sub sig2num ($) { &$_sig_name_init; &sig2num }
		1448	sub sig2name($) { &$_sig_name_init; &sig2name }
		1449
1134	sub signal {	1450	sub signal {
1135	my (undef, %arg) = @_;	1451	eval q{ # poor man's autoloading {}
		1452	# probe for availability of Async::Interrupt
		1453	if (_have_async_interrupt) {
		1454	warn "AnyEvent: using Async::Interrupt for race-free signal handling.\n" if $VERBOSE >= 8;
1136		1455
1137	unless ($SIGPIPE_R) {	1456	$SIGPIPE_R = new Async::Interrupt::EventPipe;
1138	require Fcntl;	1457	$SIG_IO = AE::io $SIGPIPE_R->fileno, 0, \&_signal_exec;
1139		1458
1140	if (AnyEvent::WIN32) {
1141	require AnyEvent::Util;
1142
1143	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
1144	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R) if $SIGPIPE_R;
1145	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W) if $SIGPIPE_W; # just in case
1146	} else {	1459	} else {
		1460	warn "AnyEvent: using emulated perl signal handling with latency timer.\n" if $VERBOSE >= 8;
		1461
		1462	require Fcntl;
		1463
		1464	if (AnyEvent::WIN32) {
		1465	require AnyEvent::Util;
		1466
		1467	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
		1468	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R, 1) if $SIGPIPE_R;
		1469	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W, 1) if $SIGPIPE_W; # just in case
		1470	} else {
1147	pipe $SIGPIPE_R, $SIGPIPE_W;	1471	pipe $SIGPIPE_R, $SIGPIPE_W;
1148	fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R;	1472	fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R;
1149	fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case	1473	fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case
1150		1474
1151	# not strictly required, as $^F is normally 2, but let's make sure...	1475	# not strictly required, as $^F is normally 2, but let's make sure...
1152	fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;	1476	fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
1153	fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;	1477	fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
		1478	}
		1479
		1480	$SIGPIPE_R
		1481	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";
		1482
		1483	$SIG_IO = AE::io $SIGPIPE_R, 0, \&_signal_exec;
1154	}	1484	}
1155		1485
1156	$SIGPIPE_R	1486	*signal = sub {
1157	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";	1487	my (undef, %arg) = @_;
1158		1488
1159	$SIG_IO = AnyEvent->io (fh => $SIGPIPE_R, poll => "r", cb => \&_signal_exec);
1160	}
1161
1162	my $signal = uc $arg{signal}	1489	my $signal = uc $arg{signal}
1163	or Carp::croak "required option 'signal' is missing";	1490	or Carp::croak "required option 'signal' is missing";
1164		1491
		1492	if ($HAVE_ASYNC_INTERRUPT) {
		1493	# async::interrupt
		1494
		1495	$signal = sig2num $signal;
1165	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};	1496	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
		1497
		1498	$SIG_ASY{$signal} ||= new Async::Interrupt
		1499	cb => sub { undef $SIG_EV{$signal} },
		1500	signal => $signal,
		1501	pipe => [$SIGPIPE_R->filenos],
		1502	pipe_autodrain => 0,
		1503	;
		1504
		1505	} else {
		1506	# pure perl
		1507
		1508	# AE::Util has been loaded in signal
		1509	$signal = sig2name $signal;
		1510	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
		1511
1166	$SIG{$signal} ||= sub {	1512	$SIG{$signal} ||= sub {
1167	local $!;	1513	local $!;
1168	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;	1514	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;
1169	undef $SIG_EV{$signal};	1515	undef $SIG_EV{$signal};
		1516	};
		1517
		1518	# can't do signal processing without introducing races in pure perl,
		1519	# so limit the signal latency.
		1520	_sig_add;
		1521	}
		1522
		1523	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
		1524	};
		1525
		1526	*AnyEvent::Base::signal::DESTROY = sub {
		1527	my ($signal, $cb) = @{$_[0]};
		1528
		1529	_sig_del;
		1530
		1531	delete $SIG_CB{$signal}{$cb};
		1532
		1533	$HAVE_ASYNC_INTERRUPT
		1534	? delete $SIG_ASY{$signal}
		1535	: # delete doesn't work with older perls - they then
		1536	# print weird messages, or just unconditionally exit
		1537	# instead of getting the default action.
		1538	undef $SIG{$signal}
		1539	unless keys %{ $SIG_CB{$signal} };
		1540	};
1170	};	1541	};
1171		1542	die if $@;
1172	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"	1543	&signal
1173	}
1174
1175	sub AnyEvent::Base::signal::DESTROY {
1176	my ($signal, $cb) = @{$_[0]};
1177
1178	delete $SIG_CB{$signal}{$cb};
1179
1180	# delete doesn't work with older perls - they then
1181	# print weird messages, or just unconditionally exit
1182	# instead of getting the default action.
1183	undef $SIG{$signal} unless keys %{ $SIG_CB{$signal} };
1184	}	1544	}
1185		1545
1186	# default implementation for ->child	1546	# default implementation for ->child
1187		1547
1188	our %PID_CB;	1548	our %PID_CB;
1189	our $CHLD_W;	1549	our $CHLD_W;
1190	our $CHLD_DELAY_W;	1550	our $CHLD_DELAY_W;
1191	our $WNOHANG;	1551	our $WNOHANG;
1192		1552
		1553	sub _emit_childstatus($$) {
		1554	my (undef, $rpid, $rstatus) = @_;
		1555
		1556	$_->($rpid, $rstatus)
		1557	for values %{ $PID_CB{$rpid} || {} },
		1558	values %{ $PID_CB{0} || {} };
		1559	}
		1560
1193	sub _sigchld {	1561	sub _sigchld {
		1562	my $pid;
		1563
		1564	AnyEvent->_emit_childstatus ($pid, $?)
1194	while (0 < (my $pid = waitpid -1, $WNOHANG)) {	1565	while ($pid = waitpid -1, $WNOHANG) > 0;
1195	$_->($pid, $?) for (values %{ $PID_CB{$pid} || {} }),
1196	(values %{ $PID_CB{0} || {} });
1197	}
1198	}	1566	}
1199		1567
1200	sub child {	1568	sub child {
1201	my (undef, %arg) = @_;	1569	my (undef, %arg) = @_;
1202		1570
1203	defined (my $pid = $arg{pid} + 0)	1571	defined (my $pid = $arg{pid} + 0)
1204	or Carp::croak "required option 'pid' is missing";	1572	or Carp::croak "required option 'pid' is missing";
1205		1573
1206	$PID_CB{$pid}{$arg{cb}} = $arg{cb};	1574	$PID_CB{$pid}{$arg{cb}} = $arg{cb};
1207		1575
		1576	# WNOHANG is almost cetrainly 1 everywhere
		1577	$WNOHANG ||= $^O =~ /^(?:openbsd|netbsd|linux|freebsd|cygwin|MSWin32)$/
		1578	? 1
1208	$WNOHANG ||= eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1;	1579	: eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1;
1209		1580
1210	unless ($CHLD_W) {	1581	unless ($CHLD_W) {
1211	$CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld);	1582	$CHLD_W = AE::signal CHLD => \&_sigchld;
1212	# child could be a zombie already, so make at least one round	1583	# child could be a zombie already, so make at least one round
1213	&_sigchld;	1584	&_sigchld;
1214	}	1585	}
1215		1586
1216	bless [$pid, $arg{cb}], "AnyEvent::Base::child"	1587	bless [$pid, $arg{cb}], "AnyEvent::Base::child"
…		…
1242	# never use more then 50% of the time for the idle watcher,	1613	# never use more then 50% of the time for the idle watcher,
1243	# within some limits	1614	# within some limits
1244	$w = 0.0001 if $w < 0.0001;	1615	$w = 0.0001 if $w < 0.0001;
1245	$w = 5 if $w > 5;	1616	$w = 5 if $w > 5;
1246		1617
1247	$w = AnyEvent->timer (after => $w, cb => $rcb);	1618	$w = AE::timer $w, 0, $rcb;
1248	} else {	1619	} else {
1249	# clean up...	1620	# clean up...
1250	undef $w;	1621	undef $w;
1251	undef $rcb;	1622	undef $rcb;
1252	}	1623	}
1253	};	1624	};
1254		1625
1255	$w = AnyEvent->timer (after => 0.05, cb => $rcb);	1626	$w = AE::timer 0.05, 0, $rcb;
1256		1627
1257	bless \\$cb, "AnyEvent::Base::idle"	1628	bless \\$cb, "AnyEvent::Base::idle"
1258	}	1629	}
1259		1630
1260	sub AnyEvent::Base::idle::DESTROY {	1631	sub AnyEvent::Base::idle::DESTROY {
…		…
1265		1636
1266	our @ISA = AnyEvent::CondVar::Base::;	1637	our @ISA = AnyEvent::CondVar::Base::;
1267		1638
1268	package AnyEvent::CondVar::Base;	1639	package AnyEvent::CondVar::Base;
1269		1640
1270	use overload	1641	#use overload
1271	'&{}' => sub { my $self = shift; sub { $self->send (@_) } },	1642	# '&{}' => sub { my $self = shift; sub { $self->send (@_) } },
1272	fallback => 1;	1643	# fallback => 1;
		1644
		1645	# save 300+ kilobytes by dirtily hardcoding overloading
		1646	${"AnyEvent::CondVar::Base::OVERLOAD"}{dummy}++; # Register with magic by touching.
		1647	*{'AnyEvent::CondVar::Base::()'} = sub { }; # "Make it findable via fetchmethod."
		1648	*{'AnyEvent::CondVar::Base::(&{}'} = sub { my $self = shift; sub { $self->send (@_) } }; # &{}
		1649	${'AnyEvent::CondVar::Base::()'} = 1; # fallback
		1650
		1651	our $WAITING;
1273		1652
1274	sub _send {	1653	sub _send {
1275	# nop	1654	# nop
1276	}	1655	}
1277		1656
…		…
1290	sub ready {	1669	sub ready {
1291	$_[0]{_ae_sent}	1670	$_[0]{_ae_sent}
1292	}	1671	}
1293		1672
1294	sub _wait {	1673	sub _wait {
		1674	$WAITING
		1675	and !$_[0]{_ae_sent}
		1676	and Carp::croak "AnyEvent::CondVar: recursive blocking wait detected";
		1677
		1678	local $WAITING = 1;
1295	AnyEvent->one_event while !$_[0]{_ae_sent};	1679	AnyEvent->one_event while !$_[0]{_ae_sent};
1296	}	1680	}
1297		1681
1298	sub recv {	1682	sub recv {
1299	$_[0]->_wait;	1683	$_[0]->_wait;
…		…
1301	Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak};	1685	Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak};
1302	wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0]	1686	wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0]
1303	}	1687	}
1304		1688
1305	sub cb {	1689	sub cb {
1306	$_[0]{_ae_cb} = $_[1] if @_ > 1;	1690	my $cv = shift;
		1691
		1692	@_
		1693	and $cv->{_ae_cb} = shift
		1694	and $cv->{_ae_sent}
		1695	and (delete $cv->{_ae_cb})->($cv);
		1696
1307	$_[0]{_ae_cb}	1697	$cv->{_ae_cb}
1308	}	1698	}
1309		1699
1310	sub begin {	1700	sub begin {
1311	++$_[0]{_ae_counter};	1701	++$_[0]{_ae_counter};
1312	$_[0]{_ae_end_cb} = $_[1] if @_ > 1;	1702	$_[0]{_ae_end_cb} = $_[1] if @_ > 1;
…		…
1361	C<PERL_ANYEVENT_MODEL>.	1751	C<PERL_ANYEVENT_MODEL>.
1362		1752
1363	When set to C<2> or higher, cause AnyEvent to report to STDERR which event	1753	When set to C<2> or higher, cause AnyEvent to report to STDERR which event
1364	model it chooses.	1754	model it chooses.
1365		1755
		1756	When set to C<8> or higher, then AnyEvent will report extra information on
		1757	which optional modules it loads and how it implements certain features.
		1758
1366	=item C<PERL_ANYEVENT_STRICT>	1759	=item C<PERL_ANYEVENT_STRICT>
1367		1760
1368	AnyEvent does not do much argument checking by default, as thorough	1761	AnyEvent does not do much argument checking by default, as thorough
1369	argument checking is very costly. Setting this variable to a true value	1762	argument checking is very costly. Setting this variable to a true value
1370	will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly	1763	will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly
1371	check the arguments passed to most method calls. If it finds any problems	1764	check the arguments passed to most method calls. If it finds any problems,
1372	it will croak.	1765	it will croak.
1373		1766
1374	In other words, enables "strict" mode.	1767	In other words, enables "strict" mode.
1375		1768
1376	Unlike C<use strict>, it is definitely recommended ot keep it off in	1769	Unlike C<use strict> (or it's modern cousin, C<< use L<common::sense>
1377	production. Keeping C<PERL_ANYEVENT_STRICT=1> in your environment while	1770	>>, it is definitely recommended to keep it off in production. Keeping
1378	developing programs can be very useful, however.	1771	C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs
		1772	can be very useful, however.
1379		1773
1380	=item C<PERL_ANYEVENT_MODEL>	1774	=item C<PERL_ANYEVENT_MODEL>
1381		1775
1382	This can be used to specify the event model to be used by AnyEvent, before	1776	This can be used to specify the event model to be used by AnyEvent, before
1383	auto detection and -probing kicks in. It must be a string consisting	1777	auto detection and -probing kicks in. It must be a string consisting
…		…
1426		1820
1427	=item C<PERL_ANYEVENT_MAX_FORKS>	1821	=item C<PERL_ANYEVENT_MAX_FORKS>
1428		1822
1429	The maximum number of child processes that C<AnyEvent::Util::fork_call>	1823	The maximum number of child processes that C<AnyEvent::Util::fork_call>
1430	will create in parallel.	1824	will create in parallel.
		1825
		1826	=item C<PERL_ANYEVENT_MAX_OUTSTANDING_DNS>
		1827
		1828	The default value for the C<max_outstanding> parameter for the default DNS
		1829	resolver - this is the maximum number of parallel DNS requests that are
		1830	sent to the DNS server.
		1831
		1832	=item C<PERL_ANYEVENT_RESOLV_CONF>
		1833
		1834	The file to use instead of F</etc/resolv.conf> (or OS-specific
		1835	configuration) in the default resolver. When set to the empty string, no
		1836	default config will be used.
		1837
		1838	=item C<PERL_ANYEVENT_CA_FILE>, C<PERL_ANYEVENT_CA_PATH>.
		1839
		1840	When neither C<ca_file> nor C<ca_path> was specified during
		1841	L<AnyEvent::TLS> context creation, and either of these environment
		1842	variables exist, they will be used to specify CA certificate locations
		1843	instead of a system-dependent default.
		1844
		1845	=item C<PERL_ANYEVENT_AVOID_GUARD> and C<PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT>
		1846
		1847	When these are set to C<1>, then the respective modules are not
		1848	loaded. Mostly good for testing AnyEvent itself.
1431		1849
1432	=back	1850	=back
1433		1851
1434	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE	1852	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE
1435		1853
…		…
1643	through AnyEvent. The benchmark creates a lot of timers (with a zero	2061	through AnyEvent. The benchmark creates a lot of timers (with a zero
1644	timeout) and I/O watchers (watching STDOUT, a pty, to become writable,	2062	timeout) and I/O watchers (watching STDOUT, a pty, to become writable,
1645	which it is), lets them fire exactly once and destroys them again.	2063	which it is), lets them fire exactly once and destroys them again.
1646		2064
1647	Source code for this benchmark is found as F<eg/bench> in the AnyEvent	2065	Source code for this benchmark is found as F<eg/bench> in the AnyEvent
1648	distribution.	2066	distribution. It uses the L<AE> interface, which makes a real difference
		2067	for the EV and Perl backends only.
1649		2068
1650	=head3 Explanation of the columns	2069	=head3 Explanation of the columns
1651		2070
1652	I<watcher> is the number of event watchers created/destroyed. Since	2071	I<watcher> is the number of event watchers created/destroyed. Since
1653	different event models feature vastly different performances, each event	2072	different event models feature vastly different performances, each event
…		…
1674	watcher.	2093	watcher.
1675		2094
1676	=head3 Results	2095	=head3 Results
1677		2096
1678	name watchers bytes create invoke destroy comment	2097	name watchers bytes create invoke destroy comment
1679	EV/EV 400000 224 0.47 0.35 0.27 EV native interface	2098	EV/EV 100000 223 0.47 0.43 0.27 EV native interface
1680	EV/Any 100000 224 2.88 0.34 0.27 EV + AnyEvent watchers	2099	EV/Any 100000 223 0.48 0.42 0.26 EV + AnyEvent watchers
1681	CoroEV/Any 100000 224 2.85 0.35 0.28 coroutines + Coro::Signal	2100	Coro::EV/Any 100000 223 0.47 0.42 0.26 coroutines + Coro::Signal
1682	Perl/Any 100000 452 4.13 0.73 0.95 pure perl implementation	2101	Perl/Any 100000 431 2.70 0.74 0.92 pure perl implementation
1683	Event/Event 16000 517 32.20 31.80 0.81 Event native interface	2102	Event/Event 16000 516 31.16 31.84 0.82 Event native interface
1684	Event/Any 16000 590 35.85 31.55 1.06 Event + AnyEvent watchers	2103	Event/Any 16000 1203 42.61 34.79 1.80 Event + AnyEvent watchers
		2104	IOAsync/Any 16000 1911 41.92 27.45 16.81 via IO::Async::Loop::IO_Poll
		2105	IOAsync/Any 16000 1726 40.69 26.37 15.25 via IO::Async::Loop::Epoll
1685	Glib/Any 16000 1357 102.33 12.31 51.00 quadratic behaviour	2106	Glib/Any 16000 1118 89.00 12.57 51.17 quadratic behaviour
1686	Tk/Any 2000 1860 27.20 66.31 14.00 SEGV with >> 2000 watchers	2107	Tk/Any 2000 1346 20.96 10.75 8.00 SEGV with >> 2000 watchers
1687	POE/Event 2000 6328 109.99 751.67 14.02 via POE::Loop::Event	2108	POE/Any 2000 6951 108.97 795.32 14.24 via POE::Loop::Event
1688	POE/Select 2000 6027 94.54 809.13 579.80 via POE::Loop::Select	2109	POE/Any 2000 6648 94.79 774.40 575.51 via POE::Loop::Select
1689		2110
1690	=head3 Discussion	2111	=head3 Discussion
1691		2112
1692	The benchmark does I<not> measure scalability of the event loop very	2113	The benchmark does I<not> measure scalability of the event loop very
1693	well. For example, a select-based event loop (such as the pure perl one)	2114	well. For example, a select-based event loop (such as the pure perl one)
…		…
1705	benchmark machine, handling an event takes roughly 1600 CPU cycles with	2126	benchmark machine, handling an event takes roughly 1600 CPU cycles with
1706	EV, 3100 CPU cycles with AnyEvent's pure perl loop and almost 3000000 CPU	2127	EV, 3100 CPU cycles with AnyEvent's pure perl loop and almost 3000000 CPU
1707	cycles with POE.	2128	cycles with POE.
1708		2129
1709	C<EV> is the sole leader regarding speed and memory use, which are both	2130	C<EV> is the sole leader regarding speed and memory use, which are both
1710	maximal/minimal, respectively. Even when going through AnyEvent, it uses	2131	maximal/minimal, respectively. When using the L<AE> API there is zero
		2132	overhead (when going through the AnyEvent API create is about 5-6 times
		2133	slower, with other times being equal, so still uses far less memory than
1711	far less memory than any other event loop and is still faster than Event	2134	any other event loop and is still faster than Event natively).
1712	natively.
1713		2135
1714	The pure perl implementation is hit in a few sweet spots (both the	2136	The pure perl implementation is hit in a few sweet spots (both the
1715	constant timeout and the use of a single fd hit optimisations in the perl	2137	constant timeout and the use of a single fd hit optimisations in the perl
1716	interpreter and the backend itself). Nevertheless this shows that it	2138	interpreter and the backend itself). Nevertheless this shows that it
1717	adds very little overhead in itself. Like any select-based backend its	2139	adds very little overhead in itself. Like any select-based backend its
1718	performance becomes really bad with lots of file descriptors (and few of	2140	performance becomes really bad with lots of file descriptors (and few of
1719	them active), of course, but this was not subject of this benchmark.	2141	them active), of course, but this was not subject of this benchmark.
1720		2142
1721	The C<Event> module has a relatively high setup and callback invocation	2143	The C<Event> module has a relatively high setup and callback invocation
1722	cost, but overall scores in on the third place.	2144	cost, but overall scores in on the third place.
		2145
		2146	C<IO::Async> performs admirably well, about on par with C<Event>, even
		2147	when using its pure perl backend.
1723		2148
1724	C<Glib>'s memory usage is quite a bit higher, but it features a	2149	C<Glib>'s memory usage is quite a bit higher, but it features a
1725	faster callback invocation and overall ends up in the same class as	2150	faster callback invocation and overall ends up in the same class as
1726	C<Event>. However, Glib scales extremely badly, doubling the number of	2151	C<Event>. However, Glib scales extremely badly, doubling the number of
1727	watchers increases the processing time by more than a factor of four,	2152	watchers increases the processing time by more than a factor of four,
…		…
1788	In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100	2213	In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100
1789	(1%) are active. This mirrors the activity of large servers with many	2214	(1%) are active. This mirrors the activity of large servers with many
1790	connections, most of which are idle at any one point in time.	2215	connections, most of which are idle at any one point in time.
1791		2216
1792	Source code for this benchmark is found as F<eg/bench2> in the AnyEvent	2217	Source code for this benchmark is found as F<eg/bench2> in the AnyEvent
1793	distribution.	2218	distribution. It uses the L<AE> interface, which makes a real difference
		2219	for the EV and Perl backends only.
1794		2220
1795	=head3 Explanation of the columns	2221	=head3 Explanation of the columns
1796		2222
1797	I<sockets> is the number of sockets, and twice the number of "servers" (as	2223	I<sockets> is the number of sockets, and twice the number of "servers" (as
1798	each server has a read and write socket end).	2224	each server has a read and write socket end).
…		…
1805	it to another server. This includes deleting the old timeout and creating	2231	it to another server. This includes deleting the old timeout and creating
1806	a new one that moves the timeout into the future.	2232	a new one that moves the timeout into the future.
1807		2233
1808	=head3 Results	2234	=head3 Results
1809		2235
1810	name sockets create request	2236	name sockets create request
1811	EV 20000 69.01 11.16	2237	EV 20000 62.66 7.99
1812	Perl 20000 73.32 35.87	2238	Perl 20000 68.32 32.64
1813	Event 20000 212.62 257.32	2239	IOAsync 20000 174.06 101.15 epoll
1814	Glib 20000 651.16 1896.30	2240	IOAsync 20000 174.67 610.84 poll
		2241	Event 20000 202.69 242.91
		2242	Glib 20000 557.01 1689.52
1815	POE 20000 349.67 12317.24 uses POE::Loop::Event	2243	POE 20000 341.54 12086.32 uses POE::Loop::Event
1816		2244
1817	=head3 Discussion	2245	=head3 Discussion
1818		2246
1819	This benchmark I<does> measure scalability and overall performance of the	2247	This benchmark I<does> measure scalability and overall performance of the
1820	particular event loop.	2248	particular event loop.
…		…
1822	EV is again fastest. Since it is using epoll on my system, the setup time	2250	EV is again fastest. Since it is using epoll on my system, the setup time
1823	is relatively high, though.	2251	is relatively high, though.
1824		2252
1825	Perl surprisingly comes second. It is much faster than the C-based event	2253	Perl surprisingly comes second. It is much faster than the C-based event
1826	loops Event and Glib.	2254	loops Event and Glib.
		2255
		2256	IO::Async performs very well when using its epoll backend, and still quite
		2257	good compared to Glib when using its pure perl backend.
1827		2258
1828	Event suffers from high setup time as well (look at its code and you will	2259	Event suffers from high setup time as well (look at its code and you will
1829	understand why). Callback invocation also has a high overhead compared to	2260	understand why). Callback invocation also has a high overhead compared to
1830	the C<< $_->() for .. >>-style loop that the Perl event loop uses. Event	2261	the C<< $_->() for .. >>-style loop that the Perl event loop uses. Event
1831	uses select or poll in basically all documented configurations.	2262	uses select or poll in basically all documented configurations.
…		…
1894	=item * C-based event loops perform very well with small number of	2325	=item * C-based event loops perform very well with small number of
1895	watchers, as the management overhead dominates.	2326	watchers, as the management overhead dominates.
1896		2327
1897	=back	2328	=back
1898		2329
		2330	=head2 THE IO::Lambda BENCHMARK
		2331
		2332	Recently I was told about the benchmark in the IO::Lambda manpage, which
		2333	could be misinterpreted to make AnyEvent look bad. In fact, the benchmark
		2334	simply compares IO::Lambda with POE, and IO::Lambda looks better (which
		2335	shouldn't come as a surprise to anybody). As such, the benchmark is
		2336	fine, and mostly shows that the AnyEvent backend from IO::Lambda isn't
		2337	very optimal. But how would AnyEvent compare when used without the extra
		2338	baggage? To explore this, I wrote the equivalent benchmark for AnyEvent.
		2339
		2340	The benchmark itself creates an echo-server, and then, for 500 times,
		2341	connects to the echo server, sends a line, waits for the reply, and then
		2342	creates the next connection. This is a rather bad benchmark, as it doesn't
		2343	test the efficiency of the framework or much non-blocking I/O, but it is a
		2344	benchmark nevertheless.
		2345
		2346	name runtime
		2347	Lambda/select 0.330 sec
		2348	+ optimized 0.122 sec
		2349	Lambda/AnyEvent 0.327 sec
		2350	+ optimized 0.138 sec
		2351	Raw sockets/select 0.077 sec
		2352	POE/select, components 0.662 sec
		2353	POE/select, raw sockets 0.226 sec
		2354	POE/select, optimized 0.404 sec
		2355
		2356	AnyEvent/select/nb 0.085 sec
		2357	AnyEvent/EV/nb 0.068 sec
		2358	+state machine 0.134 sec
		2359
		2360	The benchmark is also a bit unfair (my fault): the IO::Lambda/POE
		2361	benchmarks actually make blocking connects and use 100% blocking I/O,
		2362	defeating the purpose of an event-based solution. All of the newly
		2363	written AnyEvent benchmarks use 100% non-blocking connects (using
		2364	AnyEvent::Socket::tcp_connect and the asynchronous pure perl DNS
		2365	resolver), so AnyEvent is at a disadvantage here, as non-blocking connects
		2366	generally require a lot more bookkeeping and event handling than blocking
		2367	connects (which involve a single syscall only).
		2368
		2369	The last AnyEvent benchmark additionally uses L<AnyEvent::Handle>, which
		2370	offers similar expressive power as POE and IO::Lambda, using conventional
		2371	Perl syntax. This means that both the echo server and the client are 100%
		2372	non-blocking, further placing it at a disadvantage.
		2373
		2374	As you can see, the AnyEvent + EV combination even beats the
		2375	hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl
		2376	backend easily beats IO::Lambda and POE.
		2377
		2378	And even the 100% non-blocking version written using the high-level (and
		2379	slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda by a
		2380	large margin, even though it does all of DNS, tcp-connect and socket I/O
		2381	in a non-blocking way.
		2382
		2383	The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and
		2384	F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are
		2385	part of the IO::lambda distribution and were used without any changes.
		2386
1899		2387
1900	=head1 SIGNALS	2388	=head1 SIGNALS
1901		2389
1902	AnyEvent currently installs handlers for these signals:	2390	AnyEvent currently installs handlers for these signals:
1903		2391
…		…
1906	=item SIGCHLD	2394	=item SIGCHLD
1907		2395
1908	A handler for C<SIGCHLD> is installed by AnyEvent's child watcher	2396	A handler for C<SIGCHLD> is installed by AnyEvent's child watcher
1909	emulation for event loops that do not support them natively. Also, some	2397	emulation for event loops that do not support them natively. Also, some
1910	event loops install a similar handler.	2398	event loops install a similar handler.
		2399
		2400	Additionally, when AnyEvent is loaded and SIGCHLD is set to IGNORE, then
		2401	AnyEvent will reset it to default, to avoid losing child exit statuses.
1911		2402
1912	=item SIGPIPE	2403	=item SIGPIPE
1913		2404
1914	A no-op handler is installed for C<SIGPIPE> when C<$SIG{PIPE}> is C<undef>	2405	A no-op handler is installed for C<SIGPIPE> when C<$SIG{PIPE}> is C<undef>
1915	when AnyEvent gets loaded.	2406	when AnyEvent gets loaded.
…		…
1927		2418
1928	=back	2419	=back
1929		2420
1930	=cut	2421	=cut
1931		2422
		2423	undef $SIG{CHLD}
		2424	if $SIG{CHLD} eq 'IGNORE';
		2425
1932	$SIG{PIPE} = sub { }	2426	$SIG{PIPE} = sub { }
1933	unless defined $SIG{PIPE};	2427	unless defined $SIG{PIPE};
		2428
		2429	=head1 RECOMMENDED/OPTIONAL MODULES
		2430
		2431	One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and
		2432	it's built-in modules) are required to use it.
		2433
		2434	That does not mean that AnyEvent won't take advantage of some additional
		2435	modules if they are installed.
		2436
		2437	This section epxlains which additional modules will be used, and how they
		2438	affect AnyEvent's operetion.
		2439
		2440	=over 4
		2441
		2442	=item L<Async::Interrupt>
		2443
		2444	This slightly arcane module is used to implement fast signal handling: To
		2445	my knowledge, there is no way to do completely race-free and quick
		2446	signal handling in pure perl. To ensure that signals still get
		2447	delivered, AnyEvent will start an interval timer to wake up perl (and
		2448	catch the signals) with some delay (default is 10 seconds, look for
		2449	C<$AnyEvent::MAX_SIGNAL_LATENCY>).
		2450
		2451	If this module is available, then it will be used to implement signal
		2452	catching, which means that signals will not be delayed, and the event loop
		2453	will not be interrupted regularly, which is more efficient (And good for
		2454	battery life on laptops).
		2455
		2456	This affects not just the pure-perl event loop, but also other event loops
		2457	that have no signal handling on their own (e.g. Glib, Tk, Qt).
		2458
		2459	Some event loops (POE, Event, Event::Lib) offer signal watchers natively,
		2460	and either employ their own workarounds (POE) or use AnyEvent's workaround
		2461	(using C<$AnyEvent::MAX_SIGNAL_LATENCY>). Installing L<Async::Interrupt>
		2462	does nothing for those backends.
		2463
		2464	=item L<EV>
		2465
		2466	This module isn't really "optional", as it is simply one of the backend
		2467	event loops that AnyEvent can use. However, it is simply the best event
		2468	loop available in terms of features, speed and stability: It supports
		2469	the AnyEvent API optimally, implements all the watcher types in XS, does
		2470	automatic timer adjustments even when no monotonic clock is available,
		2471	can take avdantage of advanced kernel interfaces such as C<epoll> and
		2472	C<kqueue>, and is the fastest backend I<by far>. You can even embed
		2473	L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>).
		2474
		2475	=item L<Guard>
		2476
		2477	The guard module, when used, will be used to implement
		2478	C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a
		2479	lot less memory), but otherwise doesn't affect guard operation much. It is
		2480	purely used for performance.
		2481
		2482	=item L<JSON> and L<JSON::XS>
		2483
		2484	This module is required when you want to read or write JSON data via
		2485	L<AnyEvent::Handle>. It is also written in pure-perl, but can take
		2486	advantage of the ultra-high-speed L<JSON::XS> module when it is installed.
		2487
		2488	In fact, L<AnyEvent::Handle> will use L<JSON::XS> by default if it is
		2489	installed.
		2490
		2491	=item L<Net::SSLeay>
		2492
		2493	Implementing TLS/SSL in Perl is certainly interesting, but not very
		2494	worthwhile: If this module is installed, then L<AnyEvent::Handle> (with
		2495	the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL.
		2496
		2497	=item L<Time::HiRes>
		2498
		2499	This module is part of perl since release 5.008. It will be used when the
		2500	chosen event library does not come with a timing source on it's own. The
		2501	pure-perl event loop (L<AnyEvent::Impl::Perl>) will additionally use it to
		2502	try to use a monotonic clock for timing stability.
		2503
		2504	=back
1934		2505
1935		2506
1936	=head1 FORK	2507	=head1 FORK
1937		2508
1938	Most event libraries are not fork-safe. The ones who are usually are	2509	Most event libraries are not fork-safe. The ones who are usually are
1939	because they rely on inefficient but fork-safe C<select> or C<poll>	2510	because they rely on inefficient but fork-safe C<select> or C<poll>
1940	calls. Only L<EV> is fully fork-aware.	2511	calls. Only L<EV> is fully fork-aware.
1941		2512
1942	If you have to fork, you must either do so I<before> creating your first	2513	If you have to fork, you must either do so I<before> creating your first
1943	watcher OR you must not use AnyEvent at all in the child.	2514	watcher OR you must not use AnyEvent at all in the child OR you must do
		2515	something completely out of the scope of AnyEvent.
1944		2516
1945		2517
1946	=head1 SECURITY CONSIDERATIONS	2518	=head1 SECURITY CONSIDERATIONS
1947		2519
1948	AnyEvent can be forced to load any event model via	2520	AnyEvent can be forced to load any event model via
…		…
1962	Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can	2534	Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can
1963	be used to probe what backend is used and gain other information (which is	2535	be used to probe what backend is used and gain other information (which is
1964	probably even less useful to an attacker than PERL_ANYEVENT_MODEL), and	2536	probably even less useful to an attacker than PERL_ANYEVENT_MODEL), and
1965	$ENV{PERL_ANYEVENT_STRICT}.	2537	$ENV{PERL_ANYEVENT_STRICT}.
1966		2538
		2539	Note that AnyEvent will remove I<all> environment variables starting with
		2540	C<PERL_ANYEVENT_> from C<%ENV> when it is loaded while taint mode is
		2541	enabled.
		2542
1967		2543
1968	=head1 BUGS	2544	=head1 BUGS
1969		2545
1970	Perl 5.8 has numerous memleaks that sometimes hit this module and are hard	2546	Perl 5.8 has numerous memleaks that sometimes hit this module and are hard
1971	to work around. If you suffer from memleaks, first upgrade to Perl 5.10	2547	to work around. If you suffer from memleaks, first upgrade to Perl 5.10
…		…
1982	L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.	2558	L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.
1983		2559
1984	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,	2560	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,
1985	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,	2561	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,
1986	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,	2562	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,
1987	L<AnyEvent::Impl::POE>.	2563	L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>, L<Anyevent::Impl::Irssi>.
1988		2564
1989	Non-blocking file handles, sockets, TCP clients and	2565	Non-blocking file handles, sockets, TCP clients and
1990	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>.	2566	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.
1991		2567
1992	Asynchronous DNS: L<AnyEvent::DNS>.	2568	Asynchronous DNS: L<AnyEvent::DNS>.
1993		2569
1994	Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>,	2570	Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>,
		2571	L<Coro::Event>,
1995		2572
1996	Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>, L<AnyEvent::DNS>.	2573	Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::XMPP>,
		2574	L<AnyEvent::HTTP>.
1997		2575
1998		2576
1999	=head1 AUTHOR	2577	=head1 AUTHOR
2000		2578
2001	Marc Lehmann <schmorp@schmorp.de>	2579	Marc Lehmann <schmorp@schmorp.de>

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