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Revision 1.308 by root, Fri Dec 25 07:39:41 2009 UTC

1	=head1 NAME	1	=head1 NAME
2		2
3	AnyEvent - provide framework for multiple event loops	3	AnyEvent - the DBI of event loop programming
4		4
5	EV, Event, Glib, Tk, Perl, Event::Lib, Qt and POE are various supported	5	EV, Event, Glib, Tk, Perl, Event::Lib, Irssi, rxvt-unicode, IO::Async, Qt
6	event loops.	6	and POE are various supported event loops/environments.
7		7
8	=head1 SYNOPSIS	8	=head1 SYNOPSIS
9		9
10	use AnyEvent;	10	use AnyEvent;
11		11
…		…
40	=head1 INTRODUCTION/TUTORIAL	40	=head1 INTRODUCTION/TUTORIAL
41		41
42	This manpage is mainly a reference manual. If you are interested	42	This manpage is mainly a reference manual. If you are interested
43	in a tutorial or some gentle introduction, have a look at the	43	in a tutorial or some gentle introduction, have a look at the
44	L<AnyEvent::Intro> manpage.	44	L<AnyEvent::Intro> manpage.
		45
		46	=head1 SUPPORT
		47
		48	There is a mailinglist for discussing all things AnyEvent, and an IRC
		49	channel, too.
		50
		51	See the AnyEvent project page at the B<Schmorpforge Ta-Sa Software
		52	Repository>, at L<http://anyevent.schmorp.de>, for more info.
45		53
46	=head1 WHY YOU SHOULD USE THIS MODULE (OR NOT)	54	=head1 WHY YOU SHOULD USE THIS MODULE (OR NOT)
47		55
48	Glib, POE, IO::Async, Event... CPAN offers event models by the dozen	56	Glib, POE, IO::Async, Event... CPAN offers event models by the dozen
49	nowadays. So what is different about AnyEvent?	57	nowadays. So what is different about AnyEvent?
…		…
173	my variables are only visible after the statement in which they are	181	my variables are only visible after the statement in which they are
174	declared.	182	declared.
175		183
176	=head2 I/O WATCHERS	184	=head2 I/O WATCHERS
177		185
		186	$w = AnyEvent->io (
		187	fh => <filehandle_or_fileno>,
		188	poll => <"r" or "w">,
		189	cb => <callback>,
		190	);
		191
178	You can create an I/O watcher by calling the C<< AnyEvent->io >> method	192	You can create an I/O watcher by calling the C<< AnyEvent->io >> method
179	with the following mandatory key-value pairs as arguments:	193	with the following mandatory key-value pairs as arguments:
180		194
181	C<fh> is the Perl I<file handle> (or a naked 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
…		…
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
…		…
341	might affect timers and time-outs.	363	might affect timers and time-outs.
342		364
343	When this is the case, you can call this method, which will update the	365	When this is the case, you can call this method, which will update the
344	event loop's idea of "current time".	366	event loop's idea of "current time".
345		367
		368	A typical example would be a script in a web server (e.g. C<mod_perl>) -
		369	when mod_perl executes the script, then the event loop will have the wrong
		370	idea about the "current time" (being potentially far in the past, when the
		371	script ran the last time). In that case you should arrange a call to C<<
		372	AnyEvent->now_update >> each time the web server process wakes up again
		373	(e.g. at the start of your script, or in a handler).
		374
346	Note that updating the time I<might> cause some events to be handled.	375	Note that updating the time I<might> cause some events to be handled.
347		376
348	=back	377	=back
349		378
350	=head2 SIGNAL WATCHERS	379	=head2 SIGNAL WATCHERS
		380
		381	$w = AnyEvent->signal (signal => <uppercase_signal_name>, cb => <callback>);
351		382
352	You can watch for signals using a signal watcher, C<signal> is the signal	383	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	384	I<name> in uppercase and without any C<SIG> prefix, C<cb> is the Perl
354	callback to be invoked whenever a signal occurs.	385	callback to be invoked whenever a signal occurs.
355		386
…		…
361	invocation, and callback invocation will be synchronous. Synchronous means	392	invocation, and callback invocation will be synchronous. Synchronous means
362	that it might take a while until the signal gets handled by the process,	393	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.	394	but it is guaranteed not to interrupt any other callbacks.
364		395
365	The main advantage of using these watchers is that you can share a signal	396	The main advantage of using these watchers is that you can share a signal
366	between multiple watchers.	397	between multiple watchers, and AnyEvent will ensure that signals will not
		398	interrupt your program at bad times.
367		399
368	This watcher might use C<%SIG>, so programs overwriting those signals	400	This watcher might use C<%SIG> (depending on the event loop used),
369	directly will likely not work correctly.	401	so programs overwriting those signals directly will likely not work
		402	correctly.
370		403
371	Example: exit on SIGINT	404	Example: exit on SIGINT
372		405
373	my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });	406	my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });
374		407
		408	=head3 Restart Behaviour
		409
		410	While restart behaviour is up to the event loop implementation, most will
		411	not restart syscalls (that includes L<Async::Interrupt> and AnyEvent's
		412	pure perl implementation).
		413
		414	=head3 Safe/Unsafe Signals
		415
		416	Perl signals can be either "safe" (synchronous to opcode handling) or
		417	"unsafe" (asynchronous) - the former might get delayed indefinitely, the
		418	latter might corrupt your memory.
		419
		420	AnyEvent signal handlers are, in addition, synchronous to the event loop,
		421	i.e. they will not interrupt your running perl program but will only be
		422	called as part of the normal event handling (just like timer, I/O etc.
		423	callbacks, too).
		424
		425	=head3 Signal Races, Delays and Workarounds
		426
		427	Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support attaching
		428	callbacks to signals in a generic way, which is a pity, as you cannot
		429	do race-free signal handling in perl, requiring C libraries for
		430	this. AnyEvent will try to do it's best, which means in some cases,
		431	signals will be delayed. The maximum time a signal might be delayed is
		432	specified in C<$AnyEvent::MAX_SIGNAL_LATENCY> (default: 10 seconds). This
		433	variable can be changed only before the first signal watcher is created,
		434	and should be left alone otherwise. This variable determines how often
		435	AnyEvent polls for signals (in case a wake-up was missed). Higher values
		436	will cause fewer spurious wake-ups, which is better for power and CPU
		437	saving.
		438
		439	All these problems can be avoided by installing the optional
		440	L<Async::Interrupt> module, which works with most event loops. It will not
		441	work with inherently broken event loops such as L<Event> or L<Event::Lib>
		442	(and not with L<POE> currently, as POE does it's own workaround with
		443	one-second latency). For those, you just have to suffer the delays.
		444
375	=head2 CHILD PROCESS WATCHERS	445	=head2 CHILD PROCESS WATCHERS
376		446
		447	$w = AnyEvent->child (pid => <process id>, cb => <callback>);
		448
377	You can also watch on a child process exit and catch its exit status.	449	You can also watch on a child process exit and catch its exit status.
378		450
379	The child process is specified by the C<pid> argument (if set to C<0>, it	451	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	452	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	453	croak). The watcher will be triggered only when the child process has
382	any trace events (stopped/continued).	454	finished and an exit status is available, not on any trace events
		455	(stopped/continued).
383		456
384	The callback will be called with the pid and exit status (as returned by	457	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	458	waitpid), so unlike other watcher types, you I<can> rely on child watcher
386	callback arguments.	459	callback arguments.
387		460
…		…
403		476
404	This means you cannot create a child watcher as the very first	477	This means you cannot create a child watcher as the very first
405	thing in an AnyEvent program, you I<have> to create at least one	478	thing in an AnyEvent program, you I<have> to create at least one
406	watcher before you C<fork> the child (alternatively, you can call	479	watcher before you C<fork> the child (alternatively, you can call
407	C<AnyEvent::detect>).	480	C<AnyEvent::detect>).
		481
		482	As most event loops do not support waiting for child events, they will be
		483	emulated by AnyEvent in most cases, in which the latency and race problems
		484	mentioned in the description of signal watchers apply.
408		485
409	Example: fork a process and wait for it	486	Example: fork a process and wait for it
410		487
411	my $done = AnyEvent->condvar;	488	my $done = AnyEvent->condvar;
412		489
…		…
424	# do something else, then wait for process exit	501	# do something else, then wait for process exit
425	$done->recv;	502	$done->recv;
426		503
427	=head2 IDLE WATCHERS	504	=head2 IDLE WATCHERS
428		505
		506	$w = AnyEvent->idle (cb => <callback>);
		507
429	Sometimes there is a need to do something, but it is not so important	508	Sometimes there is a need to do something, but it is not so important
430	to do it instantly, but only when there is nothing better to do. This	509	to do it instantly, but only when there is nothing better to do. This
431	"nothing better to do" is usually defined to be "no other events need	510	"nothing better to do" is usually defined to be "no other events need
432	attention by the event loop".	511	attention by the event loop".
433		512
…		…
459	});	538	});
460	});	539	});
461		540
462	=head2 CONDITION VARIABLES	541	=head2 CONDITION VARIABLES
463		542
		543	$cv = AnyEvent->condvar;
		544
		545	$cv->send (<list>);
		546	my @res = $cv->recv;
		547
464	If you are familiar with some event loops you will know that all of them	548	If you are familiar with some event loops you will know that all of them
465	require you to run some blocking "loop", "run" or similar function that	549	require you to run some blocking "loop", "run" or similar function that
466	will actively watch for new events and call your callbacks.	550	will actively watch for new events and call your callbacks.
467		551
468	AnyEvent is different, it expects somebody else to run the event loop and	552	AnyEvent is slightly different: it expects somebody else to run the event
469	will only block when necessary (usually when told by the user).	553	loop and will only block when necessary (usually when told by the user).
470		554
471	The instrument to do that is called a "condition variable", so called	555	The instrument to do that is called a "condition variable", so called
472	because they represent a condition that must become true.	556	because they represent a condition that must become true.
473		557
		558	Now is probably a good time to look at the examples further below.
		559
474	Condition variables can be created by calling the C<< AnyEvent->condvar	560	Condition variables can be created by calling the C<< AnyEvent->condvar
475	>> method, usually without arguments. The only argument pair allowed is	561	>> method, usually without arguments. The only argument pair allowed is
476
477	C<cb>, which specifies a callback to be called when the condition variable	562	C<cb>, which specifies a callback to be called when the condition variable
478	becomes true, with the condition variable as the first argument (but not	563	becomes true, with the condition variable as the first argument (but not
479	the results).	564	the results).
480		565
481	After creation, the condition variable is "false" until it becomes "true"	566	After creation, the condition variable is "false" until it becomes "true"
…		…
486	Condition variables are similar to callbacks, except that you can	571	Condition variables are similar to callbacks, except that you can
487	optionally wait for them. They can also be called merge points - points	572	optionally wait for them. They can also be called merge points - points
488	in time where multiple outstanding events have been processed. And yet	573	in time where multiple outstanding events have been processed. And yet
489	another way to call them is transactions - each condition variable can be	574	another way to call them is transactions - each condition variable can be
490	used to represent a transaction, which finishes at some point and delivers	575	used to represent a transaction, which finishes at some point and delivers
491	a result.	576	a result. And yet some people know them as "futures" - a promise to
		577	compute/deliver something that you can wait for.
492		578
493	Condition variables are very useful to signal that something has finished,	579	Condition variables are very useful to signal that something has finished,
494	for example, if you write a module that does asynchronous http requests,	580	for example, if you write a module that does asynchronous http requests,
495	then a condition variable would be the ideal candidate to signal the	581	then a condition variable would be the ideal candidate to signal the
496	availability of results. The user can either act when the callback is	582	availability of results. The user can either act when the callback is
…		…
530	after => 1,	616	after => 1,
531	cb => sub { $result_ready->send },	617	cb => sub { $result_ready->send },
532	);	618	);
533		619
534	# this "blocks" (while handling events) till the callback	620	# this "blocks" (while handling events) till the callback
535	# calls send	621	# calls ->send
536	$result_ready->recv;	622	$result_ready->recv;
537		623
538	Example: wait for a timer, but take advantage of the fact that	624	Example: wait for a timer, but take advantage of the fact that condition
539	condition variables are also code references.	625	variables are also callable directly.
540		626
541	my $done = AnyEvent->condvar;	627	my $done = AnyEvent->condvar;
542	my $delay = AnyEvent->timer (after => 5, cb => $done);	628	my $delay = AnyEvent->timer (after => 5, cb => $done);
543	$done->recv;	629	$done->recv;
544		630
…		…
550		636
551	...	637	...
552		638
553	my @info = $couchdb->info->recv;	639	my @info = $couchdb->info->recv;
554		640
555	And this is how you would just ste a callback to be called whenever the	641	And this is how you would just set a callback to be called whenever the
556	results are available:	642	results are available:
557		643
558	$couchdb->info->cb (sub {	644	$couchdb->info->cb (sub {
559	my @info = $_[0]->recv;	645	my @info = $_[0]->recv;
560	});	646	});
…		…
578	immediately from within send.	664	immediately from within send.
579		665
580	Any arguments passed to the C<send> call will be returned by all	666	Any arguments passed to the C<send> call will be returned by all
581	future C<< ->recv >> calls.	667	future C<< ->recv >> calls.
582		668
583	Condition variables are overloaded so one can call them directly	669	Condition variables are overloaded so one can call them directly (as if
584	(as a code reference). Calling them directly is the same as calling	670	they were a code reference). Calling them directly is the same as calling
585	C<send>. Note, however, that many C-based event loops do not handle	671	C<send>.
586	overloading, so as tempting as it may be, passing a condition variable
587	instead of a callback does not work. Both the pure perl and EV loops
588	support overloading, however, as well as all functions that use perl to
589	invoke a callback (as in L<AnyEvent::Socket> and L<AnyEvent::DNS> for
590	example).
591		672
592	=item $cv->croak ($error)	673	=item $cv->croak ($error)
593		674
594	Similar to send, but causes all call's to C<< ->recv >> to invoke	675	Similar to send, but causes all call's to C<< ->recv >> to invoke
595	C<Carp::croak> with the given error message/object/scalar.	676	C<Carp::croak> with the given error message/object/scalar.
596		677
597	This can be used to signal any errors to the condition variable	678	This can be used to signal any errors to the condition variable
598	user/consumer.	679	user/consumer. Doing it this way instead of calling C<croak> directly
		680	delays the error detetcion, but has the overwhelmign advantage that it
		681	diagnoses the error at the place where the result is expected, and not
		682	deep in some event clalback without connection to the actual code causing
		683	the problem.
599		684
600	=item $cv->begin ([group callback])	685	=item $cv->begin ([group callback])
601		686
602	=item $cv->end	687	=item $cv->end
603		688
…		…
605	one. For example, a function that pings many hosts in parallel might want	690	one. For example, a function that pings many hosts in parallel might want
606	to use a condition variable for the whole process.	691	to use a condition variable for the whole process.
607		692
608	Every call to C<< ->begin >> will increment a counter, and every call to	693	Every call to C<< ->begin >> will increment a counter, and every call to
609	C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end	694	C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end
610	>>, the (last) callback passed to C<begin> will be executed. That callback	695	>>, the (last) callback passed to C<begin> will be executed, passing the
611	is I<supposed> to call C<< ->send >>, but that is not required. If no	696	condvar as first argument. That callback is I<supposed> to call C<< ->send
612	callback was set, C<send> will be called without any arguments.	697	>>, but that is not required. If no group callback was set, C<send> will
		698	be called without any arguments.
613		699
614	You can think of C<< $cv->send >> giving you an OR condition (one call	700	You can think of C<< $cv->send >> giving you an OR condition (one call
615	sends), while C<< $cv->begin >> and C<< $cv->end >> giving you an AND	701	sends), while C<< $cv->begin >> and C<< $cv->end >> giving you an AND
616	condition (all C<begin> calls must be C<end>'ed before the condvar sends).	702	condition (all C<begin> calls must be C<end>'ed before the condvar sends).
617		703
…		…
644	begung can potentially be zero:	730	begung can potentially be zero:
645		731
646	my $cv = AnyEvent->condvar;	732	my $cv = AnyEvent->condvar;
647		733
648	my %result;	734	my %result;
649	$cv->begin (sub { $cv->send (\%result) });	735	$cv->begin (sub { shift->send (\%result) });
650		736
651	for my $host (@list_of_hosts) {	737	for my $host (@list_of_hosts) {
652	$cv->begin;	738	$cv->begin;
653	ping_host_then_call_callback $host, sub {	739	ping_host_then_call_callback $host, sub {
654	$result{$host} = ...;	740	$result{$host} = ...;
…		…
699	function will call C<croak>.	785	function will call C<croak>.
700		786
701	In list context, all parameters passed to C<send> will be returned,	787	In list context, all parameters passed to C<send> will be returned,
702	in scalar context only the first one will be returned.	788	in scalar context only the first one will be returned.
703		789
		790	Note that doing a blocking wait in a callback is not supported by any
		791	event loop, that is, recursive invocation of a blocking C<< ->recv
		792	>> is not allowed, and the C<recv> call will C<croak> if such a
		793	condition is detected. This condition can be slightly loosened by using
		794	L<Coro::AnyEvent>, which allows you to do a blocking C<< ->recv >> from
		795	any thread that doesn't run the event loop itself.
		796
704	Not all event models support a blocking wait - some die in that case	797	Not all event models support a blocking wait - some die in that case
705	(programs might want to do that to stay interactive), so I<if you are	798	(programs might want to do that to stay interactive), so I<if you are
706	using this from a module, never require a blocking wait>, but let the	799	using this from a module, never require a blocking wait>. Instead, let the
707	caller decide whether the call will block or not (for example, by coupling	800	caller decide whether the call will block or not (for example, by coupling
708	condition variables with some kind of request results and supporting	801	condition variables with some kind of request results and supporting
709	callbacks so the caller knows that getting the result will not block,	802	callbacks so the caller knows that getting the result will not block,
710	while still supporting blocking waits if the caller so desires).	803	while still supporting blocking waits if the caller so desires).
711		804
712	Another reason I<never> to C<< ->recv >> in a module is that you cannot
713	sensibly have two C<< ->recv >>'s in parallel, as that would require
714	multiple interpreters or coroutines/threads, none of which C<AnyEvent>
715	can supply.
716
717	The L<Coro> module, however, I<can> and I<does> supply coroutines and, in
718	fact, L<Coro::AnyEvent> replaces AnyEvent's condvars by coroutine-safe
719	versions and also integrates coroutines into AnyEvent, making blocking
720	C<< ->recv >> calls perfectly safe as long as they are done from another
721	coroutine (one that doesn't run the event loop).
722
723	You can ensure that C<< -recv >> never blocks by setting a callback and	805	You can ensure that C<< -recv >> never blocks by setting a callback and
724	only calling C<< ->recv >> from within that callback (or at a later	806	only calling C<< ->recv >> from within that callback (or at a later
725	time). This will work even when the event loop does not support blocking	807	time). This will work even when the event loop does not support blocking
726	waits otherwise.	808	waits otherwise.
727		809
…		…
733	=item $cb = $cv->cb ($cb->($cv))	815	=item $cb = $cv->cb ($cb->($cv))
734		816
735	This is a mutator function that returns the callback set and optionally	817	This is a mutator function that returns the callback set and optionally
736	replaces it before doing so.	818	replaces it before doing so.
737		819
738	The callback will be called when the condition becomes "true", i.e. when	820	The callback will be called when the condition becomes (or already was)
739	C<send> or C<croak> are called, with the only argument being the condition	821	"true", i.e. when C<send> or C<croak> are called (or were called), with
740	variable itself. Calling C<recv> inside the callback or at any later time	822	the only argument being the condition variable itself. Calling C<recv>
741	is guaranteed not to block.	823	inside the callback or at any later time is guaranteed not to block.
742		824
743	=back	825	=back
744		826
		827	=head1 SUPPORTED EVENT LOOPS/BACKENDS
		828
		829	The available backend classes are (every class has its own manpage):
		830
		831	=over 4
		832
		833	=item Backends that are autoprobed when no other event loop can be found.
		834
		835	EV is the preferred backend when no other event loop seems to be in
		836	use. If EV is not installed, then AnyEvent will fall back to its own
		837	pure-perl implementation, which is available everywhere as it comes with
		838	AnyEvent itself.
		839
		840	AnyEvent::Impl::EV based on EV (interface to libev, best choice).
		841	AnyEvent::Impl::Perl pure-perl implementation, fast and portable.
		842
		843	=item Backends that are transparently being picked up when they are used.
		844
		845	These will be used when they are currently loaded when the first watcher
		846	is created, in which case it is assumed that the application is using
		847	them. This means that AnyEvent will automatically pick the right backend
		848	when the main program loads an event module before anything starts to
		849	create watchers. Nothing special needs to be done by the main program.
		850
		851	AnyEvent::Impl::Event based on Event, very stable, few glitches.
		852	AnyEvent::Impl::Glib based on Glib, slow but very stable.
		853	AnyEvent::Impl::Tk based on Tk, very broken.
		854	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
		855	AnyEvent::Impl::POE based on POE, very slow, some limitations.
		856	AnyEvent::Impl::Irssi used when running within irssi.
		857
		858	=item Backends with special needs.
		859
		860	Qt requires the Qt::Application to be instantiated first, but will
		861	otherwise be picked up automatically. As long as the main program
		862	instantiates the application before any AnyEvent watchers are created,
		863	everything should just work.
		864
		865	AnyEvent::Impl::Qt based on Qt.
		866
		867	Support for IO::Async can only be partial, as it is too broken and
		868	architecturally limited to even support the AnyEvent API. It also
		869	is the only event loop that needs the loop to be set explicitly, so
		870	it can only be used by a main program knowing about AnyEvent. See
		871	L<AnyEvent::Impl::Async> for the gory details.
		872
		873	AnyEvent::Impl::IOAsync based on IO::Async, cannot be autoprobed.
		874
		875	=item Event loops that are indirectly supported via other backends.
		876
		877	Some event loops can be supported via other modules:
		878
		879	There is no direct support for WxWidgets (L<Wx>) or L<Prima>.
		880
		881	B<WxWidgets> has no support for watching file handles. However, you can
		882	use WxWidgets through the POE adaptor, as POE has a Wx backend that simply
		883	polls 20 times per second, which was considered to be too horrible to even
		884	consider for AnyEvent.
		885
		886	B<Prima> is not supported as nobody seems to be using it, but it has a POE
		887	backend, so it can be supported through POE.
		888
		889	AnyEvent knows about both L<Prima> and L<Wx>, however, and will try to
		890	load L<POE> when detecting them, in the hope that POE will pick them up,
		891	in which case everything will be automatic.
		892
		893	=back
		894
745	=head1 GLOBAL VARIABLES AND FUNCTIONS	895	=head1 GLOBAL VARIABLES AND FUNCTIONS
746		896
		897	These are not normally required to use AnyEvent, but can be useful to
		898	write AnyEvent extension modules.
		899
747	=over 4	900	=over 4
748		901
749	=item $AnyEvent::MODEL	902	=item $AnyEvent::MODEL
750		903
751	Contains C<undef> until the first watcher is being created. Then it	904	Contains C<undef> until the first watcher is being created, before the
		905	backend has been autodetected.
		906
752	contains the event model that is being used, which is the name of the	907	Afterwards it contains the event model that is being used, which is the
753	Perl class implementing the model. This class is usually one of the	908	name of the Perl class implementing the model. This class is usually one
754	C<AnyEvent::Impl:xxx> modules, but can be any other class in the case	909	of the C<AnyEvent::Impl:xxx> modules, but can be any other class in the
755	AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode>).	910	case AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode> it
756		911	will be C<urxvt::anyevent>).
757	The known classes so far are:
758
759	AnyEvent::Impl::EV based on EV (an interface to libev, best choice).
760	AnyEvent::Impl::Event based on Event, second best choice.
761	AnyEvent::Impl::Perl pure-perl implementation, fast and portable.
762	AnyEvent::Impl::Glib based on Glib, third-best choice.
763	AnyEvent::Impl::Tk based on Tk, very bad choice.
764	AnyEvent::Impl::Qt based on Qt, cannot be autoprobed (see its docs).
765	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
766	AnyEvent::Impl::POE based on POE, not generic enough for full support.
767
768	# warning, support for IO::Async is only partial, as it is too broken
769	# and limited toe ven support the AnyEvent API. See AnyEvent::Impl::Async.
770	AnyEvent::Impl::IOAsync based on IO::Async, cannot be autoprobed (see its docs).
771
772	There is no support for WxWidgets, as WxWidgets has no support for
773	watching file handles. However, you can use WxWidgets through the
774	POE Adaptor, as POE has a Wx backend that simply polls 20 times per
775	second, which was considered to be too horrible to even consider for
776	AnyEvent. Likewise, other POE backends can be used by AnyEvent by using
777	it's adaptor.
778
779	AnyEvent knows about L<Prima> and L<Wx> and will try to use L<POE> when
780	autodetecting them.
781		912
782	=item AnyEvent::detect	913	=item AnyEvent::detect
783		914
784	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model	915	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model
785	if necessary. You should only call this function right before you would	916	if necessary. You should only call this function right before you would
786	have created an AnyEvent watcher anyway, that is, as late as possible at	917	have created an AnyEvent watcher anyway, that is, as late as possible at
787	runtime.	918	runtime, and not e.g. while initialising of your module.
		919
		920	If you need to do some initialisation before AnyEvent watchers are
		921	created, use C<post_detect>.
788		922
789	=item $guard = AnyEvent::post_detect { BLOCK }	923	=item $guard = AnyEvent::post_detect { BLOCK }
790		924
791	Arranges for the code block to be executed as soon as the event model is	925	Arranges for the code block to be executed as soon as the event model is
792	autodetected (or immediately if this has already happened).	926	autodetected (or immediately if this has already happened).
793		927
		928	The block will be executed I<after> the actual backend has been detected
		929	(C<$AnyEvent::MODEL> is set), but I<before> any watchers have been
		930	created, so it is possible to e.g. patch C<@AnyEvent::ISA> or do
		931	other initialisations - see the sources of L<AnyEvent::Strict> or
		932	L<AnyEvent::AIO> to see how this is used.
		933
		934	The most common usage is to create some global watchers, without forcing
		935	event module detection too early, for example, L<AnyEvent::AIO> creates
		936	and installs the global L<IO::AIO> watcher in a C<post_detect> block to
		937	avoid autodetecting the event module at load time.
		938
794	If called in scalar or list context, then it creates and returns an object	939	If called in scalar or list context, then it creates and returns an object
795	that automatically removes the callback again when it is destroyed. See	940	that automatically removes the callback again when it is destroyed (or
		941	C<undef> when the hook was immediately executed). See L<AnyEvent::AIO> for
796	L<Coro::BDB> for a case where this is useful.	942	a case where this is useful.
		943
		944	Example: Create a watcher for the IO::AIO module and store it in
		945	C<$WATCHER>. Only do so after the event loop is initialised, though.
		946
		947	our WATCHER;
		948
		949	my $guard = AnyEvent::post_detect {
		950	$WATCHER = AnyEvent->io (fh => IO::AIO::poll_fileno, poll => 'r', cb => \&IO::AIO::poll_cb);
		951	};
		952
		953	# the ||= is important in case post_detect immediately runs the block,
		954	# as to not clobber the newly-created watcher. assigning both watcher and
		955	# post_detect guard to the same variable has the advantage of users being
		956	# able to just C<undef $WATCHER> if the watcher causes them grief.
		957
		958	$WATCHER ||= $guard;
797		959
798	=item @AnyEvent::post_detect	960	=item @AnyEvent::post_detect
799		961
800	If there are any code references in this array (you can C<push> to it	962	If there are any code references in this array (you can C<push> to it
801	before or after loading AnyEvent), then they will called directly after	963	before or after loading AnyEvent), then they will called directly after
802	the event loop has been chosen.	964	the event loop has been chosen.
803		965
804	You should check C<$AnyEvent::MODEL> before adding to this array, though:	966	You should check C<$AnyEvent::MODEL> before adding to this array, though:
805	if it contains a true value then the event loop has already been detected,	967	if it is defined then the event loop has already been detected, and the
806	and the array will be ignored.	968	array will be ignored.
807		969
808	Best use C<AnyEvent::post_detect { BLOCK }> instead.	970	Best use C<AnyEvent::post_detect { BLOCK }> when your application allows
		971	it, as it takes care of these details.
		972
		973	This variable is mainly useful for modules that can do something useful
		974	when AnyEvent is used and thus want to know when it is initialised, but do
		975	not need to even load it by default. This array provides the means to hook
		976	into AnyEvent passively, without loading it.
		977
		978	Example: To load Coro::AnyEvent whenever Coro and AnyEvent are used
		979	together, you could put this into Coro (this is the actual code used by
		980	Coro to accomplish this):
		981
		982	if (defined $AnyEvent::MODEL) {
		983	# AnyEvent already initialised, so load Coro::AnyEvent
		984	require Coro::AnyEvent;
		985	} else {
		986	# AnyEvent not yet initialised, so make sure to load Coro::AnyEvent
		987	# as soon as it is
		988	push @AnyEvent::post_detect, sub { require Coro::AnyEvent };
		989	}
809		990
810	=back	991	=back
811		992
812	=head1 WHAT TO DO IN A MODULE	993	=head1 WHAT TO DO IN A MODULE
813		994
…		…
960		1141
961	=cut	1142	=cut
962		1143
963	package AnyEvent;	1144	package AnyEvent;
964		1145
965	no warnings;	1146	# basically a tuned-down version of common::sense
966	use strict qw(vars subs);	1147	sub common_sense {
		1148	# from common:.sense 1.0
		1149	${^WARNING_BITS} = "\xfc\x3f\x33\x00\x0f\xf3\xcf\xc0\xf3\xfc\x33\x00";
		1150	# use strict vars subs - NO UTF-8, as Util.pm doesn't like this atm. (uts46data.pl)
		1151	$^H |= 0x00000600;
		1152	}
967		1153
		1154	BEGIN { AnyEvent::common_sense }
		1155
968	use Carp;	1156	use Carp ();
969		1157
970	our $VERSION = 4.801;	1158	our $VERSION = '5.23';
971	our $MODEL;	1159	our $MODEL;
972		1160
973	our $AUTOLOAD;	1161	our $AUTOLOAD;
974	our @ISA;	1162	our @ISA;
975		1163
976	our @REGISTRY;	1164	our @REGISTRY;
977		1165
978	our $WIN32;	1166	our $VERBOSE;
979		1167
980	BEGIN {	1168	BEGIN {
981	eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }";	1169	eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }";
982	eval "sub TAINT(){ " . (${^TAINT}*1) . " }";	1170	eval "sub TAINT(){ " . (${^TAINT}*1) . " }";
983		1171
984	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}	1172	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}
985	if ${^TAINT};	1173	if ${^TAINT};
986	}
987		1174
988	our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1;	1175	$VERBOSE = $ENV{PERL_ANYEVENT_VERBOSE}*1;
		1176
		1177	}
		1178
		1179	our $MAX_SIGNAL_LATENCY = 10;
989		1180
990	our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred	1181	our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred
991		1182
992	{	1183	{
993	my $idx;	1184	my $idx;
…		…
995	for reverse split /\s*,\s*/,	1186	for reverse split /\s*,\s*/,
996	$ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";	1187	$ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";
997	}	1188	}
998		1189
999	my @models = (	1190	my @models = (
1000	[EV:: => AnyEvent::Impl::EV::],	1191	[EV:: => AnyEvent::Impl::EV:: , 1],
1001	[Event:: => AnyEvent::Impl::Event::],
1002	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::],	1192	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl:: , 1],
1003	# everything below here will not be autoprobed	1193	# everything below here will not (normally) be autoprobed
1004	# as the pureperl backend should work everywhere	1194	# as the pureperl backend should work everywhere
1005	# and is usually faster	1195	# and is usually faster
		1196	[Event:: => AnyEvent::Impl::Event::, 1],
		1197	[Glib:: => AnyEvent::Impl::Glib:: , 1], # becomes extremely slow with many watchers
		1198	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
		1199	[Irssi:: => AnyEvent::Impl::Irssi::], # Irssi has a bogus "Event" package
1006	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles	1200	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
1007	[Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers
1008	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
1009	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program	1201	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program
1010	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza	1202	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
1011	[Wx:: => AnyEvent::Impl::POE::],	1203	[Wx:: => AnyEvent::Impl::POE::],
1012	[Prima:: => AnyEvent::Impl::POE::],	1204	[Prima:: => AnyEvent::Impl::POE::],
1013	# IO::Async is just too broken - we would need workaorunds for its	1205	# IO::Async is just too broken - we would need workarounds for its
1014	# byzantine signal and broken child handling, among others.	1206	# byzantine signal and broken child handling, among others.
1015	# IO::Async is rather hard to detect, as it doesn't have any	1207	# IO::Async is rather hard to detect, as it doesn't have any
1016	# obvious default class.	1208	# obvious default class.
1017	# [IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program	1209	[IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program
1018	# [IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program	1210	[IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program
1019	# [IO::Async::Notifier:: => AnyEvent::Impl::IOAsync::], # requires special main program	1211	[IO::Async::Notifier:: => AnyEvent::Impl::IOAsync::], # requires special main program
		1212	[AnyEvent::Impl::IOAsync:: => AnyEvent::Impl::IOAsync::], # requires special main program
1020	);	1213	);
1021		1214
1022	our %method = map +($_ => 1),	1215	our %method = map +($_ => 1),
1023	qw(io timer time now now_update signal child idle condvar one_event DESTROY);	1216	qw(io timer time now now_update signal child idle condvar one_event DESTROY);
1024		1217
…		…
1028	my ($cb) = @_;	1221	my ($cb) = @_;
1029		1222
1030	if ($MODEL) {	1223	if ($MODEL) {
1031	$cb->();	1224	$cb->();
1032		1225
1033	1	1226	undef
1034	} else {	1227	} else {
1035	push @post_detect, $cb;	1228	push @post_detect, $cb;
1036		1229
1037	defined wantarray	1230	defined wantarray
1038	? bless \$cb, "AnyEvent::Util::postdetect"	1231	? bless \$cb, "AnyEvent::Util::postdetect"
…		…
1044	@post_detect = grep $_ != ${$_[0]}, @post_detect;	1237	@post_detect = grep $_ != ${$_[0]}, @post_detect;
1045	}	1238	}
1046		1239
1047	sub detect() {	1240	sub detect() {
1048	unless ($MODEL) {	1241	unless ($MODEL) {
1049	no strict 'refs';
1050	local $SIG{__DIE__};	1242	local $SIG{__DIE__};
1051		1243
1052	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {	1244	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {
1053	my $model = "AnyEvent::Impl::$1";	1245	my $model = "AnyEvent::Impl::$1";
1054	if (eval "require $model") {	1246	if (eval "require $model") {
1055	$MODEL = $model;	1247	$MODEL = $model;
1056	warn "AnyEvent: loaded model '$model' (forced by \$PERL_ANYEVENT_MODEL), using it.\n" if $verbose > 1;	1248	warn "AnyEvent: loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.\n" if $VERBOSE >= 2;
1057	} else {	1249	} else {
1058	warn "AnyEvent: unable to load model '$model' (from \$PERL_ANYEVENT_MODEL):\n$@" if $verbose;	1250	warn "AnyEvent: unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@" if $VERBOSE;
1059	}	1251	}
1060	}	1252	}
1061		1253
1062	# check for already loaded models	1254	# check for already loaded models
1063	unless ($MODEL) {	1255	unless ($MODEL) {
1064	for (@REGISTRY, @models) {	1256	for (@REGISTRY, @models) {
1065	my ($package, $model) = @$_;	1257	my ($package, $model) = @$_;
1066	if (${"$package\::VERSION"} > 0) {	1258	if (${"$package\::VERSION"} > 0) {
1067	if (eval "require $model") {	1259	if (eval "require $model") {
1068	$MODEL = $model;	1260	$MODEL = $model;
1069	warn "AnyEvent: autodetected model '$model', using it.\n" if $verbose > 1;	1261	warn "AnyEvent: autodetected model '$model', using it.\n" if $VERBOSE >= 2;
1070	last;	1262	last;
1071	}	1263	}
1072	}	1264	}
1073	}	1265	}
1074		1266
1075	unless ($MODEL) {	1267	unless ($MODEL) {
1076	# try to load a model	1268	# try to autoload a model
1077
1078	for (@REGISTRY, @models) {	1269	for (@REGISTRY, @models) {
1079	my ($package, $model) = @$_;	1270	my ($package, $model, $autoload) = @$_;
		1271	if (
		1272	$autoload
1080	if (eval "require $package"	1273	and eval "require $package"
1081	and ${"$package\::VERSION"} > 0	1274	and ${"$package\::VERSION"} > 0
1082	and eval "require $model") {	1275	and eval "require $model"
		1276	) {
1083	$MODEL = $model;	1277	$MODEL = $model;
1084	warn "AnyEvent: autoprobed model '$model', using it.\n" if $verbose > 1;	1278	warn "AnyEvent: autoloaded model '$model', using it.\n" if $VERBOSE >= 2;
1085	last;	1279	last;
1086	}	1280	}
1087	}	1281	}
1088		1282
1089	$MODEL	1283	$MODEL
…		…
1105		1299
1106	sub AUTOLOAD {	1300	sub AUTOLOAD {
1107	(my $func = $AUTOLOAD) =~ s/.*://;	1301	(my $func = $AUTOLOAD) =~ s/.*://;
1108		1302
1109	$method{$func}	1303	$method{$func}
1110	or croak "$func: not a valid method for AnyEvent objects";	1304	or Carp::croak "$func: not a valid method for AnyEvent objects";
1111		1305
1112	detect unless $MODEL;	1306	detect unless $MODEL;
1113		1307
1114	my $class = shift;	1308	my $class = shift;
1115	$class->$func (@_);	1309	$class->$func (@_);
…		…
1120	# allow only one watcher per fd, so we dup it to get a different one).	1314	# allow only one watcher per fd, so we dup it to get a different one).
1121	sub _dupfh($$;$$) {	1315	sub _dupfh($$;$$) {
1122	my ($poll, $fh, $r, $w) = @_;	1316	my ($poll, $fh, $r, $w) = @_;
1123		1317
1124	# cygwin requires the fh mode to be matching, unix doesn't	1318	# cygwin requires the fh mode to be matching, unix doesn't
1125	my ($rw, $mode) = $poll eq "r" ? ($r, "<") : ($w, ">");	1319	my ($rw, $mode) = $poll eq "r" ? ($r, "<&") : ($w, ">&");
1126		1320
1127	open my $fh2, "$mode&", $fh	1321	open my $fh2, $mode, $fh
1128	or die "AnyEvent->io: cannot dup() filehandle in mode '$poll': $!,";	1322	or die "AnyEvent->io: cannot dup() filehandle in mode '$poll': $!,";
1129		1323
1130	# we assume CLOEXEC is already set by perl in all important cases	1324	# we assume CLOEXEC is already set by perl in all important cases
1131		1325
1132	($fh2, $rw)	1326	($fh2, $rw)
1133	}	1327	}
1134		1328
		1329	=head1 SIMPLIFIED AE API
		1330
		1331	Starting with version 5.0, AnyEvent officially supports a second, much
		1332	simpler, API that is designed to reduce the calling, typing and memory
		1333	overhead.
		1334
		1335	See the L<AE> manpage for details.
		1336
		1337	=cut
		1338
		1339	package AE;
		1340
		1341	our $VERSION = $AnyEvent::VERSION;
		1342
		1343	sub io($$$) {
		1344	AnyEvent->io (fh => $_[0], poll => $_[1] ? "w" : "r", cb => $_[2])
		1345	}
		1346
		1347	sub timer($$$) {
		1348	AnyEvent->timer (after => $_[0], interval => $_[1], cb => $_[2])
		1349	}
		1350
		1351	sub signal($$) {
		1352	AnyEvent->signal (signal => $_[0], cb => $_[1])
		1353	}
		1354
		1355	sub child($$) {
		1356	AnyEvent->child (pid => $_[0], cb => $_[1])
		1357	}
		1358
		1359	sub idle($) {
		1360	AnyEvent->idle (cb => $_[0])
		1361	}
		1362
		1363	sub cv(;&) {
		1364	AnyEvent->condvar (@_ ? (cb => $_[0]) : ())
		1365	}
		1366
		1367	sub now() {
		1368	AnyEvent->now
		1369	}
		1370
		1371	sub now_update() {
		1372	AnyEvent->now_update
		1373	}
		1374
		1375	sub time() {
		1376	AnyEvent->time
		1377	}
		1378
1135	package AnyEvent::Base;	1379	package AnyEvent::Base;
1136		1380
1137	# default implementations for many methods	1381	# default implementations for many methods
1138		1382
1139	BEGIN {	1383	sub _time() {
		1384	# probe for availability of Time::HiRes
1140	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {	1385	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {
		1386	warn "AnyEvent: using Time::HiRes for sub-second timing accuracy.\n" if $VERBOSE >= 8;
1141	*_time = \&Time::HiRes::time;	1387	*_time = \&Time::HiRes::time;
1142	# if (eval "use POSIX (); (POSIX::times())...	1388	# if (eval "use POSIX (); (POSIX::times())...
1143	} else {	1389	} else {
		1390	warn "AnyEvent: using built-in time(), WARNING, no sub-second resolution!\n" if $VERBOSE;
1144	*_time = sub { time }; # epic fail	1391	*_time = sub { time }; # epic fail
1145	}	1392	}
		1393
		1394	&_time
1146	}	1395	}
1147		1396
1148	sub time { _time }	1397	sub time { _time }
1149	sub now { _time }	1398	sub now { _time }
1150	sub now_update { }	1399	sub now_update { }
…		…
1155	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"	1404	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"
1156	}	1405	}
1157		1406
1158	# default implementation for ->signal	1407	# default implementation for ->signal
1159		1408
		1409	our $HAVE_ASYNC_INTERRUPT;
		1410
		1411	sub _have_async_interrupt() {
		1412	$HAVE_ASYNC_INTERRUPT = 1*(!$ENV{PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT}
		1413	&& eval "use Async::Interrupt 1.02 (); 1")
		1414	unless defined $HAVE_ASYNC_INTERRUPT;
		1415
		1416	$HAVE_ASYNC_INTERRUPT
		1417	}
		1418
1160	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);	1419	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);
		1420	our (%SIG_ASY, %SIG_ASY_W);
		1421	our ($SIG_COUNT, $SIG_TW);
1161		1422
1162	sub _signal_exec {	1423	sub _signal_exec {
		1424	$HAVE_ASYNC_INTERRUPT
		1425	? $SIGPIPE_R->drain
1163	sysread $SIGPIPE_R, my $dummy, 4;	1426	: sysread $SIGPIPE_R, (my $dummy), 9;
1164		1427
1165	while (%SIG_EV) {	1428	while (%SIG_EV) {
1166	for (keys %SIG_EV) {	1429	for (keys %SIG_EV) {
1167	delete $SIG_EV{$_};	1430	delete $SIG_EV{$_};
1168	$_->() for values %{ $SIG_CB{$_} || {} };	1431	$_->() for values %{ $SIG_CB{$_} || {} };
1169	}	1432	}
1170	}	1433	}
1171	}	1434	}
1172		1435
		1436	# install a dummy wakeup watcher to reduce signal catching latency
		1437	sub _sig_add() {
		1438	unless ($SIG_COUNT++) {
		1439	# try to align timer on a full-second boundary, if possible
		1440	my $NOW = AE::now;
		1441
		1442	$SIG_TW = AE::timer
		1443	$MAX_SIGNAL_LATENCY - ($NOW - int $NOW),
		1444	$MAX_SIGNAL_LATENCY,
		1445	sub { } # just for the PERL_ASYNC_CHECK
		1446	;
		1447	}
		1448	}
		1449
		1450	sub _sig_del {
		1451	undef $SIG_TW
		1452	unless --$SIG_COUNT;
		1453	}
		1454
		1455	our $_sig_name_init; $_sig_name_init = sub {
		1456	eval q{ # poor man's autoloading
		1457	undef $_sig_name_init;
		1458
		1459	if (_have_async_interrupt) {
		1460	*sig2num = \&Async::Interrupt::sig2num;
		1461	*sig2name = \&Async::Interrupt::sig2name;
		1462	} else {
		1463	require Config;
		1464
		1465	my %signame2num;
		1466	@signame2num{ split ' ', $Config::Config{sig_name} }
		1467	= split ' ', $Config::Config{sig_num};
		1468
		1469	my @signum2name;
		1470	@signum2name[values %signame2num] = keys %signame2num;
		1471
		1472	*sig2num = sub($) {
		1473	$_[0] > 0 ? shift : $signame2num{+shift}
		1474	};
		1475	*sig2name = sub ($) {
		1476	$_[0] > 0 ? $signum2name[+shift] : shift
		1477	};
		1478	}
		1479	};
		1480	die if $@;
		1481	};
		1482
		1483	sub sig2num ($) { &$_sig_name_init; &sig2num }
		1484	sub sig2name($) { &$_sig_name_init; &sig2name }
		1485
1173	sub signal {	1486	sub signal {
1174	my (undef, %arg) = @_;	1487	eval q{ # poor man's autoloading {}
		1488	# probe for availability of Async::Interrupt
		1489	if (_have_async_interrupt) {
		1490	warn "AnyEvent: using Async::Interrupt for race-free signal handling.\n" if $VERBOSE >= 8;
1175		1491
1176	unless ($SIGPIPE_R) {	1492	$SIGPIPE_R = new Async::Interrupt::EventPipe;
1177	require Fcntl;	1493	$SIG_IO = AE::io $SIGPIPE_R->fileno, 0, \&_signal_exec;
1178		1494
1179	if (AnyEvent::WIN32) {
1180	require AnyEvent::Util;
1181
1182	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
1183	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R) if $SIGPIPE_R;
1184	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W) if $SIGPIPE_W; # just in case
1185	} else {	1495	} else {
		1496	warn "AnyEvent: using emulated perl signal handling with latency timer.\n" if $VERBOSE >= 8;
		1497
		1498	require Fcntl;
		1499
		1500	if (AnyEvent::WIN32) {
		1501	require AnyEvent::Util;
		1502
		1503	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
		1504	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R, 1) if $SIGPIPE_R;
		1505	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W, 1) if $SIGPIPE_W; # just in case
		1506	} else {
1186	pipe $SIGPIPE_R, $SIGPIPE_W;	1507	pipe $SIGPIPE_R, $SIGPIPE_W;
1187	fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R;	1508	fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R;
1188	fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case	1509	fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case
1189		1510
1190	# not strictly required, as $^F is normally 2, but let's make sure...	1511	# not strictly required, as $^F is normally 2, but let's make sure...
1191	fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;	1512	fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
1192	fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;	1513	fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
		1514	}
		1515
		1516	$SIGPIPE_R
		1517	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";
		1518
		1519	$SIG_IO = AE::io $SIGPIPE_R, 0, \&_signal_exec;
1193	}	1520	}
1194		1521
1195	$SIGPIPE_R	1522	*signal = sub {
1196	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";	1523	my (undef, %arg) = @_;
1197		1524
1198	$SIG_IO = AnyEvent->io (fh => $SIGPIPE_R, poll => "r", cb => \&_signal_exec);
1199	}
1200
1201	my $signal = uc $arg{signal}	1525	my $signal = uc $arg{signal}
1202	or Carp::croak "required option 'signal' is missing";	1526	or Carp::croak "required option 'signal' is missing";
1203		1527
		1528	if ($HAVE_ASYNC_INTERRUPT) {
		1529	# async::interrupt
		1530
		1531	$signal = sig2num $signal;
1204	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};	1532	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
		1533
		1534	$SIG_ASY{$signal} ||= new Async::Interrupt
		1535	cb => sub { undef $SIG_EV{$signal} },
		1536	signal => $signal,
		1537	pipe => [$SIGPIPE_R->filenos],
		1538	pipe_autodrain => 0,
		1539	;
		1540
		1541	} else {
		1542	# pure perl
		1543
		1544	# AE::Util has been loaded in signal
		1545	$signal = sig2name $signal;
		1546	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
		1547
1205	$SIG{$signal} ||= sub {	1548	$SIG{$signal} ||= sub {
1206	local $!;	1549	local $!;
1207	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;	1550	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;
1208	undef $SIG_EV{$signal};	1551	undef $SIG_EV{$signal};
		1552	};
		1553
		1554	# can't do signal processing without introducing races in pure perl,
		1555	# so limit the signal latency.
		1556	_sig_add;
		1557	}
		1558
		1559	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
		1560	};
		1561
		1562	*AnyEvent::Base::signal::DESTROY = sub {
		1563	my ($signal, $cb) = @{$_[0]};
		1564
		1565	_sig_del;
		1566
		1567	delete $SIG_CB{$signal}{$cb};
		1568
		1569	$HAVE_ASYNC_INTERRUPT
		1570	? delete $SIG_ASY{$signal}
		1571	: # delete doesn't work with older perls - they then
		1572	# print weird messages, or just unconditionally exit
		1573	# instead of getting the default action.
		1574	undef $SIG{$signal}
		1575	unless keys %{ $SIG_CB{$signal} };
		1576	};
1209	};	1577	};
1210		1578	die if $@;
1211	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"	1579	&signal
1212	}
1213
1214	sub AnyEvent::Base::signal::DESTROY {
1215	my ($signal, $cb) = @{$_[0]};
1216
1217	delete $SIG_CB{$signal}{$cb};
1218
1219	# delete doesn't work with older perls - they then
1220	# print weird messages, or just unconditionally exit
1221	# instead of getting the default action.
1222	undef $SIG{$signal} unless keys %{ $SIG_CB{$signal} };
1223	}	1580	}
1224		1581
1225	# default implementation for ->child	1582	# default implementation for ->child
1226		1583
1227	our %PID_CB;	1584	our %PID_CB;
1228	our $CHLD_W;	1585	our $CHLD_W;
1229	our $CHLD_DELAY_W;	1586	our $CHLD_DELAY_W;
1230	our $WNOHANG;	1587	our $WNOHANG;
1231		1588
		1589	sub _emit_childstatus($$) {
		1590	my (undef, $rpid, $rstatus) = @_;
		1591
		1592	$_->($rpid, $rstatus)
		1593	for values %{ $PID_CB{$rpid} || {} },
		1594	values %{ $PID_CB{0} || {} };
		1595	}
		1596
1232	sub _sigchld {	1597	sub _sigchld {
		1598	my $pid;
		1599
		1600	AnyEvent->_emit_childstatus ($pid, $?)
1233	while (0 < (my $pid = waitpid -1, $WNOHANG)) {	1601	while ($pid = waitpid -1, $WNOHANG) > 0;
1234	$_->($pid, $?) for (values %{ $PID_CB{$pid} || {} }),
1235	(values %{ $PID_CB{0} || {} });
1236	}
1237	}	1602	}
1238		1603
1239	sub child {	1604	sub child {
1240	my (undef, %arg) = @_;	1605	my (undef, %arg) = @_;
1241		1606
1242	defined (my $pid = $arg{pid} + 0)	1607	defined (my $pid = $arg{pid} + 0)
1243	or Carp::croak "required option 'pid' is missing";	1608	or Carp::croak "required option 'pid' is missing";
1244		1609
1245	$PID_CB{$pid}{$arg{cb}} = $arg{cb};	1610	$PID_CB{$pid}{$arg{cb}} = $arg{cb};
1246		1611
		1612	# WNOHANG is almost cetrainly 1 everywhere
		1613	$WNOHANG ||= $^O =~ /^(?:openbsd|netbsd|linux|freebsd|cygwin|MSWin32)$/
		1614	? 1
1247	$WNOHANG ||= eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1;	1615	: eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1;
1248		1616
1249	unless ($CHLD_W) {	1617	unless ($CHLD_W) {
1250	$CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld);	1618	$CHLD_W = AE::signal CHLD => \&_sigchld;
1251	# child could be a zombie already, so make at least one round	1619	# child could be a zombie already, so make at least one round
1252	&_sigchld;	1620	&_sigchld;
1253	}	1621	}
1254		1622
1255	bless [$pid, $arg{cb}], "AnyEvent::Base::child"	1623	bless [$pid, $arg{cb}], "AnyEvent::Base::child"
…		…
1281	# never use more then 50% of the time for the idle watcher,	1649	# never use more then 50% of the time for the idle watcher,
1282	# within some limits	1650	# within some limits
1283	$w = 0.0001 if $w < 0.0001;	1651	$w = 0.0001 if $w < 0.0001;
1284	$w = 5 if $w > 5;	1652	$w = 5 if $w > 5;
1285		1653
1286	$w = AnyEvent->timer (after => $w, cb => $rcb);	1654	$w = AE::timer $w, 0, $rcb;
1287	} else {	1655	} else {
1288	# clean up...	1656	# clean up...
1289	undef $w;	1657	undef $w;
1290	undef $rcb;	1658	undef $rcb;
1291	}	1659	}
1292	};	1660	};
1293		1661
1294	$w = AnyEvent->timer (after => 0.05, cb => $rcb);	1662	$w = AE::timer 0.05, 0, $rcb;
1295		1663
1296	bless \\$cb, "AnyEvent::Base::idle"	1664	bless \\$cb, "AnyEvent::Base::idle"
1297	}	1665	}
1298		1666
1299	sub AnyEvent::Base::idle::DESTROY {	1667	sub AnyEvent::Base::idle::DESTROY {
…		…
1304		1672
1305	our @ISA = AnyEvent::CondVar::Base::;	1673	our @ISA = AnyEvent::CondVar::Base::;
1306		1674
1307	package AnyEvent::CondVar::Base;	1675	package AnyEvent::CondVar::Base;
1308		1676
1309	use overload	1677	#use overload
1310	'&{}' => sub { my $self = shift; sub { $self->send (@_) } },	1678	# '&{}' => sub { my $self = shift; sub { $self->send (@_) } },
1311	fallback => 1;	1679	# fallback => 1;
		1680
		1681	# save 300+ kilobytes by dirtily hardcoding overloading
		1682	${"AnyEvent::CondVar::Base::OVERLOAD"}{dummy}++; # Register with magic by touching.
		1683	*{'AnyEvent::CondVar::Base::()'} = sub { }; # "Make it findable via fetchmethod."
		1684	*{'AnyEvent::CondVar::Base::(&{}'} = sub { my $self = shift; sub { $self->send (@_) } }; # &{}
		1685	${'AnyEvent::CondVar::Base::()'} = 1; # fallback
		1686
		1687	our $WAITING;
1312		1688
1313	sub _send {	1689	sub _send {
1314	# nop	1690	# nop
1315	}	1691	}
1316		1692
…		…
1329	sub ready {	1705	sub ready {
1330	$_[0]{_ae_sent}	1706	$_[0]{_ae_sent}
1331	}	1707	}
1332		1708
1333	sub _wait {	1709	sub _wait {
		1710	$WAITING
		1711	and !$_[0]{_ae_sent}
		1712	and Carp::croak "AnyEvent::CondVar: recursive blocking wait detected";
		1713
		1714	local $WAITING = 1;
1334	AnyEvent->one_event while !$_[0]{_ae_sent};	1715	AnyEvent->one_event while !$_[0]{_ae_sent};
1335	}	1716	}
1336		1717
1337	sub recv {	1718	sub recv {
1338	$_[0]->_wait;	1719	$_[0]->_wait;
…		…
1340	Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak};	1721	Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak};
1341	wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0]	1722	wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0]
1342	}	1723	}
1343		1724
1344	sub cb {	1725	sub cb {
1345	$_[0]{_ae_cb} = $_[1] if @_ > 1;	1726	my $cv = shift;
		1727
		1728	@_
		1729	and $cv->{_ae_cb} = shift
		1730	and $cv->{_ae_sent}
		1731	and (delete $cv->{_ae_cb})->($cv);
		1732
1346	$_[0]{_ae_cb}	1733	$cv->{_ae_cb}
1347	}	1734	}
1348		1735
1349	sub begin {	1736	sub begin {
1350	++$_[0]{_ae_counter};	1737	++$_[0]{_ae_counter};
1351	$_[0]{_ae_end_cb} = $_[1] if @_ > 1;	1738	$_[0]{_ae_end_cb} = $_[1] if @_ > 1;
…		…
1400	C<PERL_ANYEVENT_MODEL>.	1787	C<PERL_ANYEVENT_MODEL>.
1401		1788
1402	When set to C<2> or higher, cause AnyEvent to report to STDERR which event	1789	When set to C<2> or higher, cause AnyEvent to report to STDERR which event
1403	model it chooses.	1790	model it chooses.
1404		1791
		1792	When set to C<8> or higher, then AnyEvent will report extra information on
		1793	which optional modules it loads and how it implements certain features.
		1794
1405	=item C<PERL_ANYEVENT_STRICT>	1795	=item C<PERL_ANYEVENT_STRICT>
1406		1796
1407	AnyEvent does not do much argument checking by default, as thorough	1797	AnyEvent does not do much argument checking by default, as thorough
1408	argument checking is very costly. Setting this variable to a true value	1798	argument checking is very costly. Setting this variable to a true value
1409	will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly	1799	will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly
1410	check the arguments passed to most method calls. If it finds any problems,	1800	check the arguments passed to most method calls. If it finds any problems,
1411	it will croak.	1801	it will croak.
1412		1802
1413	In other words, enables "strict" mode.	1803	In other words, enables "strict" mode.
1414		1804
1415	Unlike C<use strict>, it is definitely recommended to keep it off in	1805	Unlike C<use strict> (or it's modern cousin, C<< use L<common::sense>
1416	production. Keeping C<PERL_ANYEVENT_STRICT=1> in your environment while	1806	>>, it is definitely recommended to keep it off in production. Keeping
1417	developing programs can be very useful, however.	1807	C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs
		1808	can be very useful, however.
1418		1809
1419	=item C<PERL_ANYEVENT_MODEL>	1810	=item C<PERL_ANYEVENT_MODEL>
1420		1811
1421	This can be used to specify the event model to be used by AnyEvent, before	1812	This can be used to specify the event model to be used by AnyEvent, before
1422	auto detection and -probing kicks in. It must be a string consisting	1813	auto detection and -probing kicks in. It must be a string consisting
…		…
1484		1875
1485	When neither C<ca_file> nor C<ca_path> was specified during	1876	When neither C<ca_file> nor C<ca_path> was specified during
1486	L<AnyEvent::TLS> context creation, and either of these environment	1877	L<AnyEvent::TLS> context creation, and either of these environment
1487	variables exist, they will be used to specify CA certificate locations	1878	variables exist, they will be used to specify CA certificate locations
1488	instead of a system-dependent default.	1879	instead of a system-dependent default.
		1880
		1881	=item C<PERL_ANYEVENT_AVOID_GUARD> and C<PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT>
		1882
		1883	When these are set to C<1>, then the respective modules are not
		1884	loaded. Mostly good for testing AnyEvent itself.
1489		1885
1490	=back	1886	=back
1491		1887
1492	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE	1888	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE
1493		1889
…		…
1551	warn "read: $input\n"; # output what has been read	1947	warn "read: $input\n"; # output what has been read
1552	$cv->send if $input =~ /^q/i; # quit program if /^q/i	1948	$cv->send if $input =~ /^q/i; # quit program if /^q/i
1553	},	1949	},
1554	);	1950	);
1555		1951
1556	my $time_watcher; # can only be used once
1557
1558	sub new_timer {
1559	$timer = AnyEvent->timer (after => 1, cb => sub {	1952	my $time_watcher = AnyEvent->timer (after => 1, interval => 1, cb => sub {
1560	warn "timeout\n"; # print 'timeout' about every second	1953	warn "timeout\n"; # print 'timeout' at most every second
1561	&new_timer; # and restart the time
1562	});	1954	});
1563	}
1564
1565	new_timer; # create first timer
1566		1955
1567	$cv->recv; # wait until user enters /^q/i	1956	$cv->recv; # wait until user enters /^q/i
1568		1957
1569	=head1 REAL-WORLD EXAMPLE	1958	=head1 REAL-WORLD EXAMPLE
1570		1959
…		…
1701	through AnyEvent. The benchmark creates a lot of timers (with a zero	2090	through AnyEvent. The benchmark creates a lot of timers (with a zero
1702	timeout) and I/O watchers (watching STDOUT, a pty, to become writable,	2091	timeout) and I/O watchers (watching STDOUT, a pty, to become writable,
1703	which it is), lets them fire exactly once and destroys them again.	2092	which it is), lets them fire exactly once and destroys them again.
1704		2093
1705	Source code for this benchmark is found as F<eg/bench> in the AnyEvent	2094	Source code for this benchmark is found as F<eg/bench> in the AnyEvent
1706	distribution.	2095	distribution. It uses the L<AE> interface, which makes a real difference
		2096	for the EV and Perl backends only.
1707		2097
1708	=head3 Explanation of the columns	2098	=head3 Explanation of the columns
1709		2099
1710	I<watcher> is the number of event watchers created/destroyed. Since	2100	I<watcher> is the number of event watchers created/destroyed. Since
1711	different event models feature vastly different performances, each event	2101	different event models feature vastly different performances, each event
…		…
1732	watcher.	2122	watcher.
1733		2123
1734	=head3 Results	2124	=head3 Results
1735		2125
1736	name watchers bytes create invoke destroy comment	2126	name watchers bytes create invoke destroy comment
1737	EV/EV 400000 224 0.47 0.35 0.27 EV native interface	2127	EV/EV 100000 223 0.47 0.43 0.27 EV native interface
1738	EV/Any 100000 224 2.88 0.34 0.27 EV + AnyEvent watchers	2128	EV/Any 100000 223 0.48 0.42 0.26 EV + AnyEvent watchers
1739	CoroEV/Any 100000 224 2.85 0.35 0.28 coroutines + Coro::Signal	2129	Coro::EV/Any 100000 223 0.47 0.42 0.26 coroutines + Coro::Signal
1740	Perl/Any 100000 452 4.13 0.73 0.95 pure perl implementation	2130	Perl/Any 100000 431 2.70 0.74 0.92 pure perl implementation
1741	Event/Event 16000 517 32.20 31.80 0.81 Event native interface	2131	Event/Event 16000 516 31.16 31.84 0.82 Event native interface
1742	Event/Any 16000 590 35.85 31.55 1.06 Event + AnyEvent watchers	2132	Event/Any 16000 1203 42.61 34.79 1.80 Event + AnyEvent watchers
1743	IOAsync/Any 16000 989 38.10 32.77 11.13 via IO::Async::Loop::IO_Poll	2133	IOAsync/Any 16000 1911 41.92 27.45 16.81 via IO::Async::Loop::IO_Poll
1744	IOAsync/Any 16000 990 37.59 29.50 10.61 via IO::Async::Loop::Epoll	2134	IOAsync/Any 16000 1726 40.69 26.37 15.25 via IO::Async::Loop::Epoll
1745	Glib/Any 16000 1357 102.33 12.31 51.00 quadratic behaviour	2135	Glib/Any 16000 1118 89.00 12.57 51.17 quadratic behaviour
1746	Tk/Any 2000 1860 27.20 66.31 14.00 SEGV with >> 2000 watchers	2136	Tk/Any 2000 1346 20.96 10.75 8.00 SEGV with >> 2000 watchers
1747	POE/Event 2000 6328 109.99 751.67 14.02 via POE::Loop::Event	2137	POE/Any 2000 6951 108.97 795.32 14.24 via POE::Loop::Event
1748	POE/Select 2000 6027 94.54 809.13 579.80 via POE::Loop::Select	2138	POE/Any 2000 6648 94.79 774.40 575.51 via POE::Loop::Select
1749		2139
1750	=head3 Discussion	2140	=head3 Discussion
1751		2141
1752	The benchmark does I<not> measure scalability of the event loop very	2142	The benchmark does I<not> measure scalability of the event loop very
1753	well. For example, a select-based event loop (such as the pure perl one)	2143	well. For example, a select-based event loop (such as the pure perl one)
…		…
1765	benchmark machine, handling an event takes roughly 1600 CPU cycles with	2155	benchmark machine, handling an event takes roughly 1600 CPU cycles with
1766	EV, 3100 CPU cycles with AnyEvent's pure perl loop and almost 3000000 CPU	2156	EV, 3100 CPU cycles with AnyEvent's pure perl loop and almost 3000000 CPU
1767	cycles with POE.	2157	cycles with POE.
1768		2158
1769	C<EV> is the sole leader regarding speed and memory use, which are both	2159	C<EV> is the sole leader regarding speed and memory use, which are both
1770	maximal/minimal, respectively. Even when going through AnyEvent, it uses	2160	maximal/minimal, respectively. When using the L<AE> API there is zero
		2161	overhead (when going through the AnyEvent API create is about 5-6 times
		2162	slower, with other times being equal, so still uses far less memory than
1771	far less memory than any other event loop and is still faster than Event	2163	any other event loop and is still faster than Event natively).
1772	natively.
1773		2164
1774	The pure perl implementation is hit in a few sweet spots (both the	2165	The pure perl implementation is hit in a few sweet spots (both the
1775	constant timeout and the use of a single fd hit optimisations in the perl	2166	constant timeout and the use of a single fd hit optimisations in the perl
1776	interpreter and the backend itself). Nevertheless this shows that it	2167	interpreter and the backend itself). Nevertheless this shows that it
1777	adds very little overhead in itself. Like any select-based backend its	2168	adds very little overhead in itself. Like any select-based backend its
…		…
1851	In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100	2242	In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100
1852	(1%) are active. This mirrors the activity of large servers with many	2243	(1%) are active. This mirrors the activity of large servers with many
1853	connections, most of which are idle at any one point in time.	2244	connections, most of which are idle at any one point in time.
1854		2245
1855	Source code for this benchmark is found as F<eg/bench2> in the AnyEvent	2246	Source code for this benchmark is found as F<eg/bench2> in the AnyEvent
1856	distribution.	2247	distribution. It uses the L<AE> interface, which makes a real difference
		2248	for the EV and Perl backends only.
1857		2249
1858	=head3 Explanation of the columns	2250	=head3 Explanation of the columns
1859		2251
1860	I<sockets> is the number of sockets, and twice the number of "servers" (as	2252	I<sockets> is the number of sockets, and twice the number of "servers" (as
1861	each server has a read and write socket end).	2253	each server has a read and write socket end).
…		…
1869	a new one that moves the timeout into the future.	2261	a new one that moves the timeout into the future.
1870		2262
1871	=head3 Results	2263	=head3 Results
1872		2264
1873	name sockets create request	2265	name sockets create request
1874	EV 20000 69.01 11.16	2266	EV 20000 62.66 7.99
1875	Perl 20000 73.32 35.87	2267	Perl 20000 68.32 32.64
1876	IOAsync 20000 157.00 98.14 epoll	2268	IOAsync 20000 174.06 101.15 epoll
1877	IOAsync 20000 159.31 616.06 poll	2269	IOAsync 20000 174.67 610.84 poll
1878	Event 20000 212.62 257.32	2270	Event 20000 202.69 242.91
1879	Glib 20000 651.16 1896.30	2271	Glib 20000 557.01 1689.52
1880	POE 20000 349.67 12317.24 uses POE::Loop::Event	2272	POE 20000 341.54 12086.32 uses POE::Loop::Event
1881		2273
1882	=head3 Discussion	2274	=head3 Discussion
1883		2275
1884	This benchmark I<does> measure scalability and overall performance of the	2276	This benchmark I<does> measure scalability and overall performance of the
1885	particular event loop.	2277	particular event loop.
…		…
2011	As you can see, the AnyEvent + EV combination even beats the	2403	As you can see, the AnyEvent + EV combination even beats the
2012	hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl	2404	hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl
2013	backend easily beats IO::Lambda and POE.	2405	backend easily beats IO::Lambda and POE.
2014		2406
2015	And even the 100% non-blocking version written using the high-level (and	2407	And even the 100% non-blocking version written using the high-level (and
2016	slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda by a	2408	slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda
2017	large margin, even though it does all of DNS, tcp-connect and socket I/O	2409	higher level ("unoptimised") abstractions by a large margin, even though
2018	in a non-blocking way.	2410	it does all of DNS, tcp-connect and socket I/O in a non-blocking way.
2019		2411
2020	The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and	2412	The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and
2021	F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are	2413	F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are
2022	part of the IO::lambda distribution and were used without any changes.	2414	part of the IO::Lambda distribution and were used without any changes.
2023		2415
2024		2416
2025	=head1 SIGNALS	2417	=head1 SIGNALS
2026		2418
2027	AnyEvent currently installs handlers for these signals:	2419	AnyEvent currently installs handlers for these signals:
…		…
2032		2424
2033	A handler for C<SIGCHLD> is installed by AnyEvent's child watcher	2425	A handler for C<SIGCHLD> is installed by AnyEvent's child watcher
2034	emulation for event loops that do not support them natively. Also, some	2426	emulation for event loops that do not support them natively. Also, some
2035	event loops install a similar handler.	2427	event loops install a similar handler.
2036		2428
2037	If, when AnyEvent is loaded, SIGCHLD is set to IGNORE, then AnyEvent will	2429	Additionally, when AnyEvent is loaded and SIGCHLD is set to IGNORE, then
2038	reset it to default, to avoid losing child exit statuses.	2430	AnyEvent will reset it to default, to avoid losing child exit statuses.
2039		2431
2040	=item SIGPIPE	2432	=item SIGPIPE
2041		2433
2042	A no-op handler is installed for C<SIGPIPE> when C<$SIG{PIPE}> is C<undef>	2434	A no-op handler is installed for C<SIGPIPE> when C<$SIG{PIPE}> is C<undef>
2043	when AnyEvent gets loaded.	2435	when AnyEvent gets loaded.
…		…
2061	if $SIG{CHLD} eq 'IGNORE';	2453	if $SIG{CHLD} eq 'IGNORE';
2062		2454
2063	$SIG{PIPE} = sub { }	2455	$SIG{PIPE} = sub { }
2064	unless defined $SIG{PIPE};	2456	unless defined $SIG{PIPE};
2065		2457
		2458	=head1 RECOMMENDED/OPTIONAL MODULES
		2459
		2460	One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and
		2461	it's built-in modules) are required to use it.
		2462
		2463	That does not mean that AnyEvent won't take advantage of some additional
		2464	modules if they are installed.
		2465
		2466	This section explains which additional modules will be used, and how they
		2467	affect AnyEvent's operation.
		2468
		2469	=over 4
		2470
		2471	=item L<Async::Interrupt>
		2472
		2473	This slightly arcane module is used to implement fast signal handling: To
		2474	my knowledge, there is no way to do completely race-free and quick
		2475	signal handling in pure perl. To ensure that signals still get
		2476	delivered, AnyEvent will start an interval timer to wake up perl (and
		2477	catch the signals) with some delay (default is 10 seconds, look for
		2478	C<$AnyEvent::MAX_SIGNAL_LATENCY>).
		2479
		2480	If this module is available, then it will be used to implement signal
		2481	catching, which means that signals will not be delayed, and the event loop
		2482	will not be interrupted regularly, which is more efficient (and good for
		2483	battery life on laptops).
		2484
		2485	This affects not just the pure-perl event loop, but also other event loops
		2486	that have no signal handling on their own (e.g. Glib, Tk, Qt).
		2487
		2488	Some event loops (POE, Event, Event::Lib) offer signal watchers natively,
		2489	and either employ their own workarounds (POE) or use AnyEvent's workaround
		2490	(using C<$AnyEvent::MAX_SIGNAL_LATENCY>). Installing L<Async::Interrupt>
		2491	does nothing for those backends.
		2492
		2493	=item L<EV>
		2494
		2495	This module isn't really "optional", as it is simply one of the backend
		2496	event loops that AnyEvent can use. However, it is simply the best event
		2497	loop available in terms of features, speed and stability: It supports
		2498	the AnyEvent API optimally, implements all the watcher types in XS, does
		2499	automatic timer adjustments even when no monotonic clock is available,
		2500	can take avdantage of advanced kernel interfaces such as C<epoll> and
		2501	C<kqueue>, and is the fastest backend I<by far>. You can even embed
		2502	L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>).
		2503
		2504	=item L<Guard>
		2505
		2506	The guard module, when used, will be used to implement
		2507	C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a
		2508	lot less memory), but otherwise doesn't affect guard operation much. It is
		2509	purely used for performance.
		2510
		2511	=item L<JSON> and L<JSON::XS>
		2512
		2513	One of these modules is required when you want to read or write JSON data
		2514	via L<AnyEvent::Handle>. It is also written in pure-perl, but can take
		2515	advantage of the ultra-high-speed L<JSON::XS> module when it is installed.
		2516
		2517	In fact, L<AnyEvent::Handle> will use L<JSON::XS> by default if it is
		2518	installed.
		2519
		2520	=item L<Net::SSLeay>
		2521
		2522	Implementing TLS/SSL in Perl is certainly interesting, but not very
		2523	worthwhile: If this module is installed, then L<AnyEvent::Handle> (with
		2524	the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL.
		2525
		2526	=item L<Time::HiRes>
		2527
		2528	This module is part of perl since release 5.008. It will be used when the
		2529	chosen event library does not come with a timing source on it's own. The
		2530	pure-perl event loop (L<AnyEvent::Impl::Perl>) will additionally use it to
		2531	try to use a monotonic clock for timing stability.
		2532
		2533	=back
		2534
		2535
2066	=head1 FORK	2536	=head1 FORK
2067		2537
2068	Most event libraries are not fork-safe. The ones who are usually are	2538	Most event libraries are not fork-safe. The ones who are usually are
2069	because they rely on inefficient but fork-safe C<select> or C<poll>	2539	because they rely on inefficient but fork-safe C<select> or C<poll> calls
2070	calls. Only L<EV> is fully fork-aware.	2540	- higher performance APIs such as BSD's kqueue or the dreaded Linux epoll
		2541	are usually badly thought-out hacks that are incompatible with fork in
		2542	one way or another. Only L<EV> is fully fork-aware and ensures that you
		2543	continue event-processing in both parent and child (or both, if you know
		2544	what you are doing).
		2545
		2546	This means that, in general, you cannot fork and do event processing in
		2547	the child if the event library was initialised before the fork (which
		2548	usually happens when the first AnyEvent watcher is created, or the library
		2549	is loaded).
2071		2550
2072	If you have to fork, you must either do so I<before> creating your first	2551	If you have to fork, you must either do so I<before> creating your first
2073	watcher OR you must not use AnyEvent at all in the child.	2552	watcher OR you must not use AnyEvent at all in the child OR you must do
		2553	something completely out of the scope of AnyEvent.
		2554
		2555	The problem of doing event processing in the parent I<and> the child
		2556	is much more complicated: even for backends that I<are> fork-aware or
		2557	fork-safe, their behaviour is not usually what you want: fork clones all
		2558	watchers, that means all timers, I/O watchers etc. are active in both
		2559	parent and child, which is almost never what you want. USing C<exec>
		2560	to start worker children from some kind of manage rprocess is usually
		2561	preferred, because it is much easier and cleaner, at the expense of having
		2562	to have another binary.
2074		2563
2075		2564
2076	=head1 SECURITY CONSIDERATIONS	2565	=head1 SECURITY CONSIDERATIONS
2077		2566
2078	AnyEvent can be forced to load any event model via	2567	AnyEvent can be forced to load any event model via
…		…
2116	L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.	2605	L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.
2117		2606
2118	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,	2607	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,
2119	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,	2608	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,
2120	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,	2609	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,
2121	L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>.	2610	L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>, L<Anyevent::Impl::Irssi>.
2122		2611
2123	Non-blocking file handles, sockets, TCP clients and	2612	Non-blocking file handles, sockets, TCP clients and
2124	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.	2613	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.
2125		2614
2126	Asynchronous DNS: L<AnyEvent::DNS>.	2615	Asynchronous DNS: L<AnyEvent::DNS>.

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