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Revision 1.279 by root, Sun Aug 9 16:05:11 2009 UTC

1	=head1 NAME	1	=head1 NAME
2		2
3	AnyEvent - provide framework for multiple event loops	3	AnyEvent - the DBI of event loop programming
4		4
5	EV, Event, Glib, Tk, Perl, Event::Lib, Qt, 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 = 4.352;	1120	our $VERSION = '5.0';
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	[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
975	);	1177	);
976		1178
977	our %method = map +($_ => 1),	1179	our %method = map +($_ => 1),
978	qw(io timer time now now_update signal child idle condvar one_event DESTROY);	1180	qw(io timer time now now_update signal child idle condvar one_event DESTROY);
979		1181
…		…
983	my ($cb) = @_;	1185	my ($cb) = @_;
984		1186
985	if ($MODEL) {	1187	if ($MODEL) {
986	$cb->();	1188	$cb->();
987		1189
988	1	1190	undef
989	} else {	1191	} else {
990	push @post_detect, $cb;	1192	push @post_detect, $cb;
991		1193
992	defined wantarray	1194	defined wantarray
993	? bless \$cb, "AnyEvent::Util::postdetect"	1195	? bless \$cb, "AnyEvent::Util::postdetect"
…		…
999	@post_detect = grep $_ != ${$_[0]}, @post_detect;	1201	@post_detect = grep $_ != ${$_[0]}, @post_detect;
1000	}	1202	}
1001		1203
1002	sub detect() {	1204	sub detect() {
1003	unless ($MODEL) {	1205	unless ($MODEL) {
1004	no strict 'refs';
1005	local $SIG{__DIE__};	1206	local $SIG{__DIE__};
1006		1207
1007	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {	1208	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {
1008	my $model = "AnyEvent::Impl::$1";	1209	my $model = "AnyEvent::Impl::$1";
1009	if (eval "require $model") {	1210	if (eval "require $model") {
1010	$MODEL = $model;	1211	$MODEL = $model;
1011	warn "AnyEvent: loaded model '$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 $VERBOSE >= 2;
1012	} else {	1213	} else {
1013	warn "AnyEvent: unable to load model '$model' (from \$PERL_ANYEVENT_MODEL):\n$@" if $verbose;	1214	warn "AnyEvent: unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@" if $VERBOSE;
1014	}	1215	}
1015	}	1216	}
1016		1217
1017	# check for already loaded models	1218	# check for already loaded models
1018	unless ($MODEL) {	1219	unless ($MODEL) {
1019	for (@REGISTRY, @models) {	1220	for (@REGISTRY, @models) {
1020	my ($package, $model) = @$_;	1221	my ($package, $model) = @$_;
1021	if (${"$package\::VERSION"} > 0) {	1222	if (${"$package\::VERSION"} > 0) {
1022	if (eval "require $model") {	1223	if (eval "require $model") {
1023	$MODEL = $model;	1224	$MODEL = $model;
1024	warn "AnyEvent: autodetected model '$model', using it.\n" if $verbose > 1;	1225	warn "AnyEvent: autodetected model '$model', using it.\n" if $VERBOSE >= 2;
1025	last;	1226	last;
1026	}	1227	}
1027	}	1228	}
1028	}	1229	}
1029		1230
1030	unless ($MODEL) {	1231	unless ($MODEL) {
1031	# try to load a model	1232	# try to autoload a model
1032
1033	for (@REGISTRY, @models) {	1233	for (@REGISTRY, @models) {
1034	my ($package, $model) = @$_;	1234	my ($package, $model, $autoload) = @$_;
		1235	if (
		1236	$autoload
1035	if (eval "require $package"	1237	and eval "require $package"
1036	and ${"$package\::VERSION"} > 0	1238	and ${"$package\::VERSION"} > 0
1037	and eval "require $model") {	1239	and eval "require $model"
		1240	) {
1038	$MODEL = $model;	1241	$MODEL = $model;
1039	warn "AnyEvent: autoprobed model '$model', using it.\n" if $verbose > 1;	1242	warn "AnyEvent: autoloaded model '$model', using it.\n" if $VERBOSE >= 2;
1040	last;	1243	last;
1041	}	1244	}
1042	}	1245	}
1043		1246
1044	$MODEL	1247	$MODEL
…		…
1060		1263
1061	sub AUTOLOAD {	1264	sub AUTOLOAD {
1062	(my $func = $AUTOLOAD) =~ s/.*://;	1265	(my $func = $AUTOLOAD) =~ s/.*://;
1063		1266
1064	$method{$func}	1267	$method{$func}
1065	or croak "$func: not a valid method for AnyEvent objects";	1268	or Carp::croak "$func: not a valid method for AnyEvent objects";
1066		1269
1067	detect unless $MODEL;	1270	detect unless $MODEL;
1068		1271
1069	my $class = shift;	1272	my $class = shift;
1070	$class->$func (@_);	1273	$class->$func (@_);
1071	}	1274	}
1072		1275
1073	# 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
1074	# to support binding more than one watcher per filehandle (they usually	1277	# 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).	1278	# allow only one watcher per fd, so we dup it to get a different one).
1076	sub _dupfh($$$$) {	1279	sub _dupfh($$;$$) {
1077	my ($poll, $fh, $r, $w) = @_;	1280	my ($poll, $fh, $r, $w) = @_;
1078		1281
1079	# cygwin requires the fh mode to be matching, unix doesn't	1282	# cygwin requires the fh mode to be matching, unix doesn't
1080	my ($rw, $mode) = $poll eq "r" ? ($r, "<")	1283	my ($rw, $mode) = $poll eq "r" ? ($r, "<&") : ($w, ">&");
1081	: $poll eq "w" ? ($w, ">")
1082	: Carp::croak "AnyEvent->io requires poll set to either 'r' or 'w'";
1083		1284
1084	open my $fh2, "$mode&" . fileno $fh	1285	open my $fh2, $mode, $fh
1085	or die "cannot dup() filehandle: $!,";	1286	or die "AnyEvent->io: cannot dup() filehandle in mode '$poll': $!,";
1086		1287
1087	# we assume CLOEXEC is already set by perl in all important cases	1288	# we assume CLOEXEC is already set by perl in all important cases
1088		1289
1089	($fh2, $rw)	1290	($fh2, $rw)
1090	}	1291	}
1091		1292
		1293	=head1 SIMPLIFIED AE API
		1294
		1295	Starting with version 5.0, AnyEvent officially supports a second, much
		1296	simpler, API that is designed to reduce the calling, typing and memory
		1297	overhead.
		1298
		1299	See the L<AE> manpage for details.
		1300
		1301	=cut
		1302
		1303	package AE;
		1304
		1305	our $VERSION = $AnyEvent::VERSION;
		1306
		1307	sub io($$$) {
		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
1092	package AnyEvent::Base;	1343	package AnyEvent::Base;
1093		1344
1094	# default implementations for many methods	1345	# default implementations for many methods
1095		1346
1096	BEGIN {	1347	sub _time {
		1348	# probe for availability of Time::HiRes
1097	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;
1098	*_time = \&Time::HiRes::time;	1351	*_time = \&Time::HiRes::time;
1099	# if (eval "use POSIX (); (POSIX::times())...	1352	# if (eval "use POSIX (); (POSIX::times())...
1100	} else {	1353	} else {
		1354	warn "AnyEvent: using built-in time(), WARNING, no sub-second resolution!\n" if $VERBOSE;
1101	*_time = sub { time }; # epic fail	1355	*_time = sub { time }; # epic fail
1102	}	1356	}
		1357
		1358	&_time
1103	}	1359	}
1104		1360
1105	sub time { _time }	1361	sub time { _time }
1106	sub now { _time }	1362	sub now { _time }
1107	sub now_update { }	1363	sub now_update { }
…		…
1112	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"	1368	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"
1113	}	1369	}
1114		1370
1115	# default implementation for ->signal	1371	# default implementation for ->signal
1116		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
1117	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);
1118		1386
1119	sub _signal_exec {	1387	sub _signal_exec {
		1388	$HAVE_ASYNC_INTERRUPT
		1389	? $SIGPIPE_R->drain
1120	sysread $SIGPIPE_R, my $dummy, 4;	1390	: sysread $SIGPIPE_R, my $dummy, 9;
1121		1391
1122	while (%SIG_EV) {	1392	while (%SIG_EV) {
1123	for (keys %SIG_EV) {	1393	for (keys %SIG_EV) {
1124	delete $SIG_EV{$_};	1394	delete $SIG_EV{$_};
1125	$_->() for values %{ $SIG_CB{$_} || {} };	1395	$_->() for values %{ $SIG_CB{$_} || {} };
1126	}	1396	}
1127	}	1397	}
1128	}	1398	}
1129		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
1130	sub signal {	1450	sub signal {
1131	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;
1132		1455
1133	unless ($SIGPIPE_R) {	1456	$SIGPIPE_R = new Async::Interrupt::EventPipe;
1134	require Fcntl;	1457	$SIG_IO = AE::io $SIGPIPE_R->fileno, 0, \&_signal_exec;
1135		1458
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 {	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 {
1143	pipe $SIGPIPE_R, $SIGPIPE_W;	1471	pipe $SIGPIPE_R, $SIGPIPE_W;
1144	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;
1145	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
		1474
		1475	# not strictly required, as $^F is normally 2, but let's make sure...
		1476	fcntl $SIGPIPE_R, &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;
1146	}	1484	}
1147		1485
1148	$SIGPIPE_R	1486	*signal = sub {
1149	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";	1487	my (undef, %arg) = @_;
1150		1488
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}	1489	my $signal = uc $arg{signal}
1159	or Carp::croak "required option 'signal' is missing";	1490	or Carp::croak "required option 'signal' is missing";
1160		1491
		1492	if ($HAVE_ASYNC_INTERRUPT) {
		1493	# async::interrupt
		1494
		1495	$signal = sig2num $signal;
1161	$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
1162	$SIG{$signal} ||= sub {	1512	$SIG{$signal} ||= sub {
1163	local $!;	1513	local $!;
1164	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;	1514	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;
1165	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	};
1166	};	1541	};
1167		1542	die if $@;
1168	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"	1543	&signal
1169	}
1170
1171	sub AnyEvent::Base::signal::DESTROY {
1172	my ($signal, $cb) = @{$_[0]};
1173
1174	delete $SIG_CB{$signal}{$cb};
1175
1176	delete $SIG{$signal} unless keys %{ $SIG_CB{$signal} };
1177	}	1544	}
1178		1545
1179	# default implementation for ->child	1546	# default implementation for ->child
1180		1547
1181	our %PID_CB;	1548	our %PID_CB;
1182	our $CHLD_W;	1549	our $CHLD_W;
1183	our $CHLD_DELAY_W;	1550	our $CHLD_DELAY_W;
1184	our $PID_IDLE;
1185	our $WNOHANG;	1551	our $WNOHANG;
1186		1552
1187	sub _child_wait {	1553	sub _emit_childstatus($$) {
1188	while (0 < (my $pid = waitpid -1, $WNOHANG)) {	1554	my (undef, $rpid, $rstatus) = @_;
		1555
		1556	$_->($rpid, $rstatus)
1189	$_->($pid, $?) for (values %{ $PID_CB{$pid} || {} }),	1557	for values %{ $PID_CB{$rpid} || {} },
1190	(values %{ $PID_CB{0} || {} });	1558	values %{ $PID_CB{0} || {} };
1191	}
1192
1193	undef $PID_IDLE;
1194	}	1559	}
1195		1560
1196	sub _sigchld {	1561	sub _sigchld {
1197	# make sure we deliver these changes "synchronous" with the event loop.	1562	my $pid;
1198	$CHLD_DELAY_W ||= AnyEvent->timer (after => 0, cb => sub {	1563
1199	undef $CHLD_DELAY_W;	1564	AnyEvent->_emit_childstatus ($pid, $?)
1200	&_child_wait;	1565	while ($pid = waitpid -1, $WNOHANG) > 0;
1201	});
1202	}	1566	}
1203		1567
1204	sub child {	1568	sub child {
1205	my (undef, %arg) = @_;	1569	my (undef, %arg) = @_;
1206		1570
1207	defined (my $pid = $arg{pid} + 0)	1571	defined (my $pid = $arg{pid} + 0)
1208	or Carp::croak "required option 'pid' is missing";	1572	or Carp::croak "required option 'pid' is missing";
1209		1573
1210	$PID_CB{$pid}{$arg{cb}} = $arg{cb};	1574	$PID_CB{$pid}{$arg{cb}} = $arg{cb};
1211		1575
1212	unless ($WNOHANG) {	1576	# WNOHANG is almost cetrainly 1 everywhere
		1577	$WNOHANG ||= $^O =~ /^(?:openbsd|netbsd|linux|freebsd|cygwin|MSWin32)$/
		1578	? 1
1213	$WNOHANG = eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1;	1579	: eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1;
1214	}
1215		1580
1216	unless ($CHLD_W) {	1581	unless ($CHLD_W) {
1217	$CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld);	1582	$CHLD_W = AE::signal CHLD => \&_sigchld;
1218	# child could be a zombie already, so make at least one round	1583	# child could be a zombie already, so make at least one round
1219	&_sigchld;	1584	&_sigchld;
1220	}	1585	}
1221		1586
1222	bless [$pid, $arg{cb}], "AnyEvent::Base::child"	1587	bless [$pid, $arg{cb}], "AnyEvent::Base::child"
…		…
1230		1595
1231	undef $CHLD_W unless keys %PID_CB;	1596	undef $CHLD_W unless keys %PID_CB;
1232	}	1597	}
1233		1598
1234	# idle emulation is done by simply using a timer, regardless	1599	# idle emulation is done by simply using a timer, regardless
1235	# of whether the proces sis idle or not, and not letting	1600	# of whether the process is idle or not, and not letting
1236	# the callback use more than 50% of the time.	1601	# the callback use more than 50% of the time.
1237	sub idle {	1602	sub idle {
1238	my (undef, %arg) = @_;	1603	my (undef, %arg) = @_;
1239		1604
1240	my ($cb, $w, $rcb) = $arg{cb};	1605	my ($cb, $w, $rcb) = $arg{cb};
…		…
1248	# 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,
1249	# within some limits	1614	# within some limits
1250	$w = 0.0001 if $w < 0.0001;	1615	$w = 0.0001 if $w < 0.0001;
1251	$w = 5 if $w > 5;	1616	$w = 5 if $w > 5;
1252		1617
1253	$w = AnyEvent->timer (after => $w, cb => $rcb);	1618	$w = AE::timer $w, 0, $rcb;
1254	} else {	1619	} else {
1255	# clean up...	1620	# clean up...
1256	undef $w;	1621	undef $w;
1257	undef $rcb;	1622	undef $rcb;
1258	}	1623	}
1259	};	1624	};
1260		1625
1261	$w = AnyEvent->timer (after => 0.05, cb => $rcb);	1626	$w = AE::timer 0.05, 0, $rcb;
1262		1627
1263	bless \\$cb, "AnyEvent::Base::idle"	1628	bless \\$cb, "AnyEvent::Base::idle"
1264	}	1629	}
1265		1630
1266	sub AnyEvent::Base::idle::DESTROY {	1631	sub AnyEvent::Base::idle::DESTROY {
…		…
1271		1636
1272	our @ISA = AnyEvent::CondVar::Base::;	1637	our @ISA = AnyEvent::CondVar::Base::;
1273		1638
1274	package AnyEvent::CondVar::Base;	1639	package AnyEvent::CondVar::Base;
1275		1640
1276	use overload	1641	#use overload
1277	'&{}' => sub { my $self = shift; sub { $self->send (@_) } },	1642	# '&{}' => sub { my $self = shift; sub { $self->send (@_) } },
1278	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;
1279		1652
1280	sub _send {	1653	sub _send {
1281	# nop	1654	# nop
1282	}	1655	}
1283		1656
…		…
1296	sub ready {	1669	sub ready {
1297	$_[0]{_ae_sent}	1670	$_[0]{_ae_sent}
1298	}	1671	}
1299		1672
1300	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 $WAITING = 1;
1301	AnyEvent->one_event while !$_[0]{_ae_sent};	1679	AnyEvent->one_event while !$_[0]{_ae_sent};
1302	}	1680	}
1303		1681
1304	sub recv {	1682	sub recv {
1305	$_[0]->_wait;	1683	$_[0]->_wait;
…		…
1307	Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak};	1685	Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak};
1308	wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0]	1686	wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0]
1309	}	1687	}
1310		1688
1311	sub cb {	1689	sub cb {
1312	$_[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
1313	$_[0]{_ae_cb}	1697	$cv->{_ae_cb}
1314	}	1698	}
1315		1699
1316	sub begin {	1700	sub begin {
1317	++$_[0]{_ae_counter};	1701	++$_[0]{_ae_counter};
1318	$_[0]{_ae_end_cb} = $_[1] if @_ > 1;	1702	$_[0]{_ae_end_cb} = $_[1] if @_ > 1;
…		…
1346	so on.	1730	so on.
1347		1731
1348	=head1 ENVIRONMENT VARIABLES	1732	=head1 ENVIRONMENT VARIABLES
1349		1733
1350	The following environment variables are used by this module or its	1734	The following environment variables are used by this module or its
1351	submodules:	1735	submodules.
		1736
		1737	Note that AnyEvent will remove I<all> environment variables starting with
		1738	C<PERL_ANYEVENT_> from C<%ENV> when it is loaded while taint mode is
		1739	enabled.
1352		1740
1353	=over 4	1741	=over 4
1354		1742
1355	=item C<PERL_ANYEVENT_VERBOSE>	1743	=item C<PERL_ANYEVENT_VERBOSE>
1356		1744
…		…
1363	C<PERL_ANYEVENT_MODEL>.	1751	C<PERL_ANYEVENT_MODEL>.
1364		1752
1365	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
1366	model it chooses.	1754	model it chooses.
1367		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
1368	=item C<PERL_ANYEVENT_STRICT>	1759	=item C<PERL_ANYEVENT_STRICT>
1369		1760
1370	AnyEvent does not do much argument checking by default, as thorough	1761	AnyEvent does not do much argument checking by default, as thorough
1371	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
1372	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
1373	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,
1374	it will croak.	1765	it will croak.
1375		1766
1376	In other words, enables "strict" mode.	1767	In other words, enables "strict" mode.
1377		1768
1378	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>
1379	production. Keeping C<PERL_ANYEVENT_STRICT=1> in your environment while	1770	>>, it is definitely recommended to keep it off in production. Keeping
1380	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.
1381		1773
1382	=item C<PERL_ANYEVENT_MODEL>	1774	=item C<PERL_ANYEVENT_MODEL>
1383		1775
1384	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
1385	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
…		…
1428		1820
1429	=item C<PERL_ANYEVENT_MAX_FORKS>	1821	=item C<PERL_ANYEVENT_MAX_FORKS>
1430		1822
1431	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>
1432	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.
1433		1849
1434	=back	1850	=back
1435		1851
1436	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE	1852	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE
1437		1853
…		…
1645	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
1646	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,
1647	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.
1648		2064
1649	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
1650	distribution.	2066	distribution. It uses the L<AE> interface, which makes a real difference
		2067	for the EV and Perl backends only.
1651		2068
1652	=head3 Explanation of the columns	2069	=head3 Explanation of the columns
1653		2070
1654	I<watcher> is the number of event watchers created/destroyed. Since	2071	I<watcher> is the number of event watchers created/destroyed. Since
1655	different event models feature vastly different performances, each event	2072	different event models feature vastly different performances, each event
…		…
1676	watcher.	2093	watcher.
1677		2094
1678	=head3 Results	2095	=head3 Results
1679		2096
1680	name watchers bytes create invoke destroy comment	2097	name watchers bytes create invoke destroy comment
1681	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
1682	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
1683	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
1684	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
1685	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
1686	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
1687	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
1688	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
1689	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
1690	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
1691		2110
1692	=head3 Discussion	2111	=head3 Discussion
1693		2112
1694	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
1695	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)
…		…
1707	benchmark machine, handling an event takes roughly 1600 CPU cycles with	2126	benchmark machine, handling an event takes roughly 1600 CPU cycles with
1708	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
1709	cycles with POE.	2128	cycles with POE.
1710		2129
1711	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
1712	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
1713	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).
1714	natively.
1715		2135
1716	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
1717	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
1718	interpreter and the backend itself). Nevertheless this shows that it	2138	interpreter and the backend itself). Nevertheless this shows that it
1719	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
1720	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
1721	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.
1722		2142
1723	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
1724	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.
1725		2148
1726	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
1727	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
1728	C<Event>. However, Glib scales extremely badly, doubling the number of	2151	C<Event>. However, Glib scales extremely badly, doubling the number of
1729	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,
…		…
1790	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
1791	(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
1792	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.
1793		2216
1794	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
1795	distribution.	2218	distribution. It uses the L<AE> interface, which makes a real difference
		2219	for the EV and Perl backends only.
1796		2220
1797	=head3 Explanation of the columns	2221	=head3 Explanation of the columns
1798		2222
1799	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
1800	each server has a read and write socket end).	2224	each server has a read and write socket end).
…		…
1807	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
1808	a new one that moves the timeout into the future.	2232	a new one that moves the timeout into the future.
1809		2233
1810	=head3 Results	2234	=head3 Results
1811		2235
1812	name sockets create request	2236	name sockets create request
1813	EV 20000 69.01 11.16	2237	EV 20000 62.66 7.99
1814	Perl 20000 73.32 35.87	2238	Perl 20000 68.32 32.64
1815	Event 20000 212.62 257.32	2239	IOAsync 20000 174.06 101.15 epoll
1816	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
1817	POE 20000 349.67 12317.24 uses POE::Loop::Event	2243	POE 20000 341.54 12086.32 uses POE::Loop::Event
1818		2244
1819	=head3 Discussion	2245	=head3 Discussion
1820		2246
1821	This benchmark I<does> measure scalability and overall performance of the	2247	This benchmark I<does> measure scalability and overall performance of the
1822	particular event loop.	2248	particular event loop.
…		…
1824	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
1825	is relatively high, though.	2251	is relatively high, though.
1826		2252
1827	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
1828	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.
1829		2258
1830	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
1831	understand why). Callback invocation also has a high overhead compared to	2260	understand why). Callback invocation also has a high overhead compared to
1832	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
1833	uses select or poll in basically all documented configurations.	2262	uses select or poll in basically all documented configurations.
…		…
1896	=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
1897	watchers, as the management overhead dominates.	2326	watchers, as the management overhead dominates.
1898		2327
1899	=back	2328	=back
1900		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
1901		2387
1902	=head1 SIGNALS	2388	=head1 SIGNALS
1903		2389
1904	AnyEvent currently installs handlers for these signals:	2390	AnyEvent currently installs handlers for these signals:
1905		2391
…		…
1908	=item SIGCHLD	2394	=item SIGCHLD
1909		2395
1910	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
1911	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
1912	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.
1913		2402
1914	=item SIGPIPE	2403	=item SIGPIPE
1915		2404
1916	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>
1917	when AnyEvent gets loaded.	2406	when AnyEvent gets loaded.
…		…
1929		2418
1930	=back	2419	=back
1931		2420
1932	=cut	2421	=cut
1933		2422
		2423	undef $SIG{CHLD}
		2424	if $SIG{CHLD} eq 'IGNORE';
		2425
1934	$SIG{PIPE} = sub { }	2426	$SIG{PIPE} = sub { }
1935	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
1936		2505
1937		2506
1938	=head1 FORK	2507	=head1 FORK
1939		2508
1940	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
1941	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>
1942	calls. Only L<EV> is fully fork-aware.	2511	calls. Only L<EV> is fully fork-aware.
1943		2512
1944	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
1945	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.
1946		2516
1947		2517
1948	=head1 SECURITY CONSIDERATIONS	2518	=head1 SECURITY CONSIDERATIONS
1949		2519
1950	AnyEvent can be forced to load any event model via	2520	AnyEvent can be forced to load any event model via
…		…
1962	use AnyEvent;	2532	use AnyEvent;
1963		2533
1964	Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can	2534	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	2535	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	2536	probably even less useful to an attacker than PERL_ANYEVENT_MODEL), and
1967	$ENV{PERL_ANYEGENT_STRICT}.	2537	$ENV{PERL_ANYEVENT_STRICT}.
		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.
1968		2542
1969		2543
1970	=head1 BUGS	2544	=head1 BUGS
1971		2545
1972	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
…		…
1984	L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.	2558	L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.
1985		2559
1986	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,	2560	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,
1987	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>,
1988	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,	2562	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,
1989	L<AnyEvent::Impl::POE>.	2563	L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>, L<Anyevent::Impl::Irssi>.
1990		2564
1991	Non-blocking file handles, sockets, TCP clients and	2565	Non-blocking file handles, sockets, TCP clients and
1992	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>.	2566	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.
1993		2567
1994	Asynchronous DNS: L<AnyEvent::DNS>.	2568	Asynchronous DNS: L<AnyEvent::DNS>.
1995		2569
1996	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>,
1997		2572
1998	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>.
1999		2575
2000		2576
2001	=head1 AUTHOR	2577	=head1 AUTHOR
2002		2578
2003	Marc Lehmann <schmorp@schmorp.de>	2579	Marc Lehmann <schmorp@schmorp.de>

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