ViewVC Help

View File | Revision Log | Show Annotations | Download File

/cvs/AnyEvent/lib/AnyEvent.pm

Comparing AnyEvent/lib/AnyEvent.pm (file contents):
Revision 1.228 by root, Wed Jul 8 01:11:12 2009 UTC vs.
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 and POE are various supported	5	EV, Event, Glib, Tk, Perl, Event::Lib, Irssi, rxvt-unicode, IO::Async, Qt
6	event loops.	6	and POE are various supported event loops/environments.
7		7
8	=head1 SYNOPSIS	8	=head1 SYNOPSIS
9		9
10	use AnyEvent;	10	use AnyEvent;
11		11
…		…
40	=head1 INTRODUCTION/TUTORIAL	40	=head1 INTRODUCTION/TUTORIAL
41		41
42	This manpage is mainly a reference manual. If you are interested	42	This manpage is mainly a reference manual. If you are interested
43	in a tutorial or some gentle introduction, have a look at the	43	in a tutorial or some gentle introduction, have a look at the
44	L<AnyEvent::Intro> manpage.	44	L<AnyEvent::Intro> manpage.
		45
		46	=head1 SUPPORT
		47
		48	There is a mailinglist for discussing all things AnyEvent, and an IRC
		49	channel, too.
		50
		51	See the AnyEvent project page at the B<Schmorpforge Ta-Sa Software
		52	Repository>, at L<http://anyevent.schmorp.de>, for more info.
45		53
46	=head1 WHY YOU SHOULD USE THIS MODULE (OR NOT)	54	=head1 WHY YOU SHOULD USE THIS MODULE (OR NOT)
47		55
48	Glib, POE, IO::Async, Event... CPAN offers event models by the dozen	56	Glib, POE, IO::Async, Event... CPAN offers event models by the dozen
49	nowadays. So what is different about AnyEvent?	57	nowadays. So what is different about AnyEvent?
…		…
173	my variables are only visible after the statement in which they are	181	my variables are only visible after the statement in which they are
174	declared.	182	declared.
175		183
176	=head2 I/O WATCHERS	184	=head2 I/O WATCHERS
177		185
		186	$w = AnyEvent->io (
		187	fh => <filehandle_or_fileno>,
		188	poll => <"r" or "w">,
		189	cb => <callback>,
		190	);
		191
178	You can create an I/O watcher by calling the C<< AnyEvent->io >> method	192	You can create an I/O watcher by calling the C<< AnyEvent->io >> method
179	with the following mandatory key-value pairs as arguments:	193	with the following mandatory key-value pairs as arguments:
180		194
181	C<fh> is the Perl I<file handle> (I<not> file descriptor, see below) to	195	C<fh> is the Perl I<file handle> (or a naked file descriptor) to watch
182	watch for events (AnyEvent might or might not keep a reference to this	196	for events (AnyEvent might or might not keep a reference to this file
183	file handle). Note that only file handles pointing to things for which	197	handle). Note that only file handles pointing to things for which
184	non-blocking operation makes sense are allowed. This includes sockets,	198	non-blocking operation makes sense are allowed. This includes sockets,
185	most character devices, pipes, fifos and so on, but not for example files	199	most character devices, pipes, fifos and so on, but not for example files
186	or block devices.	200	or block devices.
187		201
188	C<poll> must be a string that is either C<r> or C<w>, which creates a	202	C<poll> must be a string that is either C<r> or C<w>, which creates a
…		…
209	chomp (my $input = <STDIN>);	223	chomp (my $input = <STDIN>);
210	warn "read: $input\n";	224	warn "read: $input\n";
211	undef $w;	225	undef $w;
212	});	226	});
213		227
214	=head3 GETTING A FILE HANDLE FROM A FILE DESCRIPTOR
215
216	It is not uncommon to only have a file descriptor, while AnyEvent requires
217	a Perl file handle.
218
219	There are basically two methods to convert a file descriptor into a file handle. If you own
220	the file descriptor, you can open it with C<&=>, as in:
221
222	open my $fh, "<&=$fileno" or die "xxx: §!";
223
224	This will "own" the file descriptor, meaning that when C<$fh> is
225	destroyed, it will automatically close the C<$fileno>. Also, note that
226	the open mode (read, write, read/write) must correspond with how the
227	underlying file descriptor was opened.
228
229	In many cases, taking over the file descriptor is now what you want, in
230	which case the only alternative is to dup the file descriptor:
231
232	open my $fh, "<&$fileno" or die "xxx: $!";
233
234	This has the advantage of not closing the file descriptor and the
235	disadvantage of making a slow copy.
236
237	=head2 TIME WATCHERS	228	=head2 TIME WATCHERS
		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	);
238		237
239	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 >>
240	method with the following mandatory arguments:	239	method with the following mandatory arguments:
241		240
242	C<after> specifies after how many seconds (fractional values are	241	C<after> specifies after how many seconds (fractional values are
…		…
370		369
371	=back	370	=back
372		371
373	=head2 SIGNAL WATCHERS	372	=head2 SIGNAL WATCHERS
374		373
		374	$w = AnyEvent->signal (signal => <uppercase_signal_name>, cb => <callback>);
		375
375	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
376	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
377	callback to be invoked whenever a signal occurs.	378	callback to be invoked whenever a signal occurs.
378		379
379	Although the callback might get passed parameters, their value and	380	Although the callback might get passed parameters, their value and
…		…
384	invocation, and callback invocation will be synchronous. Synchronous means	385	invocation, and callback invocation will be synchronous. Synchronous means
385	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,
386	but it is guaranteed not to interrupt any other callbacks.	387	but it is guaranteed not to interrupt any other callbacks.
387		388
388	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
389	between multiple watchers.	390	between multiple watchers, and AnyEvent will ensure that signals will not
		391	interrupt your program at bad times.
390		392
391	This watcher might use C<%SIG>, so programs overwriting those signals	393	This watcher might use C<%SIG> (depending on the event loop used),
392	directly will likely not work correctly.	394	so programs overwriting those signals directly will likely not work
		395	correctly.
393		396
394	Example: exit on SIGINT	397	Example: exit on SIGINT
395		398
396	my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });	399	my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });
397		400
		401	=head3 Signal Races, Delays and Workarounds
		402
		403	Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support attaching
		404	callbacks to signals in a generic way, which is a pity, as you cannot
		405	do race-free signal handling in perl, requiring C libraries for
		406	this. AnyEvent will try to do it's best, which means in some cases,
		407	signals will be delayed. The maximum time a signal might be delayed is
		408	specified in C<$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
398	=head2 CHILD PROCESS WATCHERS	421	=head2 CHILD PROCESS WATCHERS
399		422
		423	$w = AnyEvent->child (pid => <process id>, cb => <callback>);
		424
400	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.
401		426
402	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,
403	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
404	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
405	any trace events (stopped/continued).	430	finished and an exit status is available, not on any trace events
		431	(stopped/continued).
406		432
407	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
408	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
409	callback arguments.	435	callback arguments.
410		436
…		…
426		452
427	This means you cannot create a child watcher as the very first	453	This means you cannot create a child watcher as the very first
428	thing in an AnyEvent program, you I<have> to create at least one	454	thing in an AnyEvent program, you I<have> to create at least one
429	watcher before you C<fork> the child (alternatively, you can call	455	watcher before you C<fork> the child (alternatively, you can call
430	C<AnyEvent::detect>).	456	C<AnyEvent::detect>).
		457
		458	As most event loops do not support waiting for child events, they will be
		459	emulated by AnyEvent in most cases, in which the latency and race problems
		460	mentioned in the description of signal watchers apply.
431		461
432	Example: fork a process and wait for it	462	Example: fork a process and wait for it
433		463
434	my $done = AnyEvent->condvar;	464	my $done = AnyEvent->condvar;
435		465
…		…
447	# do something else, then wait for process exit	477	# do something else, then wait for process exit
448	$done->recv;	478	$done->recv;
449		479
450	=head2 IDLE WATCHERS	480	=head2 IDLE WATCHERS
451		481
		482	$w = AnyEvent->idle (cb => <callback>);
		483
452	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
453	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
454	"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
455	attention by the event loop".	487	attention by the event loop".
456		488
…		…
482	});	514	});
483	});	515	});
484		516
485	=head2 CONDITION VARIABLES	517	=head2 CONDITION VARIABLES
486		518
		519	$cv = AnyEvent->condvar;
		520
		521	$cv->send (<list>);
		522	my @res = $cv->recv;
		523
487	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
488	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
489	will actively watch for new events and call your callbacks.	526	will actively watch for new events and call your callbacks.
490		527
491	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
492	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).
493		530
494	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
495	because they represent a condition that must become true.	532	because they represent a condition that must become true.
496		533
		534	Now is probably a good time to look at the examples further below.
		535
497	Condition variables can be created by calling the C<< AnyEvent->condvar	536	Condition variables can be created by calling the C<< AnyEvent->condvar
498	>> method, usually without arguments. The only argument pair allowed is	537	>> method, usually without arguments. The only argument pair allowed is
499
500	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
501	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
502	the results).	540	the results).
503		541
504	After creation, the condition variable is "false" until it becomes "true"	542	After creation, the condition variable is "false" until it becomes "true"
…		…
509	Condition variables are similar to callbacks, except that you can	547	Condition variables are similar to callbacks, except that you can
510	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
511	in time where multiple outstanding events have been processed. And yet	549	in time where multiple outstanding events have been processed. And yet
512	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
513	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
514	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.
515		554
516	Condition variables are very useful to signal that something has finished,	555	Condition variables are very useful to signal that something has finished,
517	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,
518	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
519	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
…		…
553	after => 1,	592	after => 1,
554	cb => sub { $result_ready->send },	593	cb => sub { $result_ready->send },
555	);	594	);
556		595
557	# this "blocks" (while handling events) till the callback	596	# this "blocks" (while handling events) till the callback
558	# calls send	597	# calls -<send
559	$result_ready->recv;	598	$result_ready->recv;
560		599
561	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
562	condition variables are also code references.	601	variables are also callable directly.
563		602
564	my $done = AnyEvent->condvar;	603	my $done = AnyEvent->condvar;
565	my $delay = AnyEvent->timer (after => 5, cb => $done);	604	my $delay = AnyEvent->timer (after => 5, cb => $done);
566	$done->recv;	605	$done->recv;
567		606
…		…
573		612
574	...	613	...
575		614
576	my @info = $couchdb->info->recv;	615	my @info = $couchdb->info->recv;
577		616
578	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
579	results are available:	618	results are available:
580		619
581	$couchdb->info->cb (sub {	620	$couchdb->info->cb (sub {
582	my @info = $_[0]->recv;	621	my @info = $_[0]->recv;
583	});	622	});
…		…
601	immediately from within send.	640	immediately from within send.
602		641
603	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
604	future C<< ->recv >> calls.	643	future C<< ->recv >> calls.
605		644
606	Condition variables are overloaded so one can call them directly	645	Condition variables are overloaded so one can call them directly (as if
607	(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
608	C<send>. Note, however, that many C-based event loops do not handle	647	C<send>.
609	overloading, so as tempting as it may be, passing a condition variable
610	instead of a callback does not work. Both the pure perl and EV loops
611	support overloading, however, as well as all functions that use perl to
612	invoke a callback (as in L<AnyEvent::Socket> and L<AnyEvent::DNS> for
613	example).
614		648
615	=item $cv->croak ($error)	649	=item $cv->croak ($error)
616		650
617	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
618	C<Carp::croak> with the given error message/object/scalar.	652	C<Carp::croak> with the given error message/object/scalar.
619		653
620	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
621	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.
622		660
623	=item $cv->begin ([group callback])	661	=item $cv->begin ([group callback])
624		662
625	=item $cv->end	663	=item $cv->end
626		664
…		…
722	function will call C<croak>.	760	function will call C<croak>.
723		761
724	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,
725	in scalar context only the first one will be returned.	763	in scalar context only the first one will be returned.
726		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
727	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
728	(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
729	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
730	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
731	condition variables with some kind of request results and supporting	776	condition variables with some kind of request results and supporting
732	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,
733	while still supporting blocking waits if the caller so desires).	778	while still supporting blocking waits if the caller so desires).
734		779
735	Another reason I<never> to C<< ->recv >> in a module is that you cannot
736	sensibly have two C<< ->recv >>'s in parallel, as that would require
737	multiple interpreters or coroutines/threads, none of which C<AnyEvent>
738	can supply.
739
740	The L<Coro> module, however, I<can> and I<does> supply coroutines and, in
741	fact, L<Coro::AnyEvent> replaces AnyEvent's condvars by coroutine-safe
742	versions and also integrates coroutines into AnyEvent, making blocking
743	C<< ->recv >> calls perfectly safe as long as they are done from another
744	coroutine (one that doesn't run the event loop).
745
746	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
747	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
748	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
749	waits otherwise.	783	waits otherwise.
750		784
…		…
756	=item $cb = $cv->cb ($cb->($cv))	790	=item $cb = $cv->cb ($cb->($cv))
757		791
758	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
759	replaces it before doing so.	793	replaces it before doing so.
760		794
761	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)
762	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
763	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>
764	is guaranteed not to block.	798	inside the callback or at any later time is guaranteed not to block.
765		799
766	=back	800	=back
767		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
768	=head1 GLOBAL VARIABLES AND FUNCTIONS	870	=head1 GLOBAL VARIABLES AND FUNCTIONS
769		871
		872	These are not normally required to use AnyEvent, but can be useful to
		873	write AnyEvent extension modules.
		874
770	=over 4	875	=over 4
771		876
772	=item $AnyEvent::MODEL	877	=item $AnyEvent::MODEL
773		878
774	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
775	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
776	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
777	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
778	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
779		886	will be C<urxvt::anyevent>).
780	The known classes so far are:
781
782	AnyEvent::Impl::EV based on EV (an interface to libev, best choice).
783	AnyEvent::Impl::Event based on Event, second best choice.
784	AnyEvent::Impl::Perl pure-perl implementation, fast and portable.
785	AnyEvent::Impl::Glib based on Glib, third-best choice.
786	AnyEvent::Impl::Tk based on Tk, very bad choice.
787	AnyEvent::Impl::Qt based on Qt, cannot be autoprobed (see its docs).
788	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
789	AnyEvent::Impl::POE based on POE, not generic enough for full support.
790
791	# warning, support for IO::Async is only partial, as it is too broken
792	# and limited toe ven support the AnyEvent API. See AnyEvent::Impl::Async.
793	AnyEvent::Impl::IOAsync based on IO::Async, cannot be autoprobed (see its docs).
794
795	There is no support for WxWidgets, as WxWidgets has no support for
796	watching file handles. However, you can use WxWidgets through the
797	POE Adaptor, as POE has a Wx backend that simply polls 20 times per
798	second, which was considered to be too horrible to even consider for
799	AnyEvent. Likewise, other POE backends can be used by AnyEvent by using
800	it's adaptor.
801
802	AnyEvent knows about L<Prima> and L<Wx> and will try to use L<POE> when
803	autodetecting them.
804		887
805	=item AnyEvent::detect	888	=item AnyEvent::detect
806		889
807	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model	890	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model
808	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
809	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
810	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>.
811		897
812	=item $guard = AnyEvent::post_detect { BLOCK }	898	=item $guard = AnyEvent::post_detect { BLOCK }
813		899
814	Arranges for the code block to be executed as soon as the event model is	900	Arranges for the code block to be executed as soon as the event model is
815	autodetected (or immediately if this has already happened).	901	autodetected (or immediately if this has already happened).
816		902
		903	The block will be executed I<after> the actual backend has been detected
		904	(C<$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
817	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
818	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
819	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 ||= $guard;
820		934
821	=item @AnyEvent::post_detect	935	=item @AnyEvent::post_detect
822		936
823	If there are any code references in this array (you can C<push> to it	937	If there are any code references in this array (you can C<push> to it
824	before or after loading AnyEvent), then they will called directly after	938	before or after loading AnyEvent), then they will called directly after
825	the event loop has been chosen.	939	the event loop has been chosen.
826		940
827	You should check C<$AnyEvent::MODEL> before adding to this array, though:	941	You should check C<$AnyEvent::MODEL> before adding to this array, though:
828	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
829	and the array will be ignored.	943	array will be ignored.
830		944
831	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.
832		952
833	=back	953	=back
834		954
835	=head1 WHAT TO DO IN A MODULE	955	=head1 WHAT TO DO IN A MODULE
836		956
…		…
891		1011
892		1012
893	=head1 OTHER MODULES	1013	=head1 OTHER MODULES
894		1014
895	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
896	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
897	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
898	available via CPAN.	1018	come with AnyEvent, most are available via CPAN.
899		1019
900	=over 4	1020	=over 4
901		1021
902	=item L<AnyEvent::Util>	1022	=item L<AnyEvent::Util>
903		1023
…		…
912		1032
913	=item L<AnyEvent::Handle>	1033	=item L<AnyEvent::Handle>
914		1034
915	Provide read and write buffers, manages watchers for reads and writes,	1035	Provide read and write buffers, manages watchers for reads and writes,
916	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
917	non-blocking SSL/TLS.	1037	non-blocking SSL/TLS (via L<AnyEvent::TLS>.
918		1038
919	=item L<AnyEvent::DNS>	1039	=item L<AnyEvent::DNS>
920		1040
921	Provides rich asynchronous DNS resolver capabilities.	1041	Provides rich asynchronous DNS resolver capabilities.
922		1042
…		…
950		1070
951	=item L<AnyEvent::GPSD>	1071	=item L<AnyEvent::GPSD>
952		1072
953	A non-blocking interface to gpsd, a daemon delivering GPS information.	1073	A non-blocking interface to gpsd, a daemon delivering GPS information.
954		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
955	=item L<AnyEvent::IGS>	1084	=item L<AnyEvent::IGS>
956		1085
957	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
958	L<App::IGS>).	1087	L<App::IGS>).
959		1088
960	=item L<AnyEvent::IRC>
961
962	AnyEvent based IRC client module family (replacing the older Net::IRC3).
963
964	=item L<Net::XMPP2>
965
966	AnyEvent based XMPP (Jabber protocol) module family.
967
968	=item L<Net::FCP>	1089	=item L<Net::FCP>
969		1090
970	AnyEvent-based implementation of the Freenet Client Protocol, birthplace	1091	AnyEvent-based implementation of the Freenet Client Protocol, birthplace
971	of AnyEvent.	1092	of AnyEvent.
972		1093
…		…
976		1097
977	=item L<Coro>	1098	=item L<Coro>
978		1099
979	Has special support for AnyEvent via L<Coro::AnyEvent>.	1100	Has special support for AnyEvent via L<Coro::AnyEvent>.
980		1101
981	=item L<IO::Lambda>
982
983	The lambda approach to I/O - don't ask, look there. Can use AnyEvent.
984
985	=back	1102	=back
986		1103
987	=cut	1104	=cut
988		1105
989	package AnyEvent;	1106	package AnyEvent;
990		1107
		1108	# basically a tuned-down version of common::sense
		1109	sub common_sense {
991	no warnings;	1110	# no warnings
		1111	${^WARNING_BITS} ^= ${^WARNING_BITS};
992	use strict qw(vars subs);	1112	# use strict vars subs
		1113	$^H |= 0x00000600;
		1114	}
993		1115
		1116	BEGIN { AnyEvent::common_sense }
		1117
994	use Carp;	1118	use Carp ();
995		1119
996	our $VERSION = 4.8;	1120	our $VERSION = '5.0';
997	our $MODEL;	1121	our $MODEL;
998		1122
999	our $AUTOLOAD;	1123	our $AUTOLOAD;
1000	our @ISA;	1124	our @ISA;
1001		1125
1002	our @REGISTRY;	1126	our @REGISTRY;
1003		1127
1004	our $WIN32;	1128	our $WIN32;
		1129
		1130	our $VERBOSE;
1005		1131
1006	BEGIN {	1132	BEGIN {
1007	eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }";	1133	eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }";
1008	eval "sub TAINT(){ " . (${^TAINT}*1) . " }";	1134	eval "sub TAINT(){ " . (${^TAINT}*1) . " }";
1009		1135
1010	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}	1136	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}
1011	if ${^TAINT};	1137	if ${^TAINT};
1012	}
1013		1138
1014	our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1;	1139	$VERBOSE = $ENV{PERL_ANYEVENT_VERBOSE}*1;
		1140
		1141	}
		1142
		1143	our $MAX_SIGNAL_LATENCY = 10;
1015		1144
1016	our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred	1145	our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred
1017		1146
1018	{	1147	{
1019	my $idx;	1148	my $idx;
…		…
1021	for reverse split /\s*,\s*/,	1150	for reverse split /\s*,\s*/,
1022	$ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";	1151	$ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";
1023	}	1152	}
1024		1153
1025	my @models = (	1154	my @models = (
1026	[EV:: => AnyEvent::Impl::EV::],	1155	[EV:: => AnyEvent::Impl::EV:: , 1],
1027	[Event:: => AnyEvent::Impl::Event::],
1028	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::],	1156	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl:: , 1],
1029	# everything below here will not be autoprobed	1157	# everything below here will not (normally) be autoprobed
1030	# as the pureperl backend should work everywhere	1158	# as the pureperl backend should work everywhere
1031	# 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
1032	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles	1164	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
1033	[Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers
1034	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
1035	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program	1165	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program
1036	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza	1166	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
1037	[Wx:: => AnyEvent::Impl::POE::],	1167	[Wx:: => AnyEvent::Impl::POE::],
1038	[Prima:: => AnyEvent::Impl::POE::],	1168	[Prima:: => AnyEvent::Impl::POE::],
1039	# IO::Async is just too broken - we would need workaorunds for its	1169	# IO::Async is just too broken - we would need workarounds for its
1040	# byzantine signal and broken child handling, among others.	1170	# byzantine signal and broken child handling, among others.
1041	# IO::Async is rather hard to detect, as it doesn't have any	1171	# IO::Async is rather hard to detect, as it doesn't have any
1042	# obvious default class.	1172	# obvious default class.
1043	# [IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program	1173	[IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program
1044	# [IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program	1174	[IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program
1045	# [IO::Async::Notifier:: => 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
1046	);	1177	);
1047		1178
1048	our %method = map +($_ => 1),	1179	our %method = map +($_ => 1),
1049	qw(io timer time now now_update signal child idle condvar one_event DESTROY);	1180	qw(io timer time now now_update signal child idle condvar one_event DESTROY);
1050		1181
…		…
1054	my ($cb) = @_;	1185	my ($cb) = @_;
1055		1186
1056	if ($MODEL) {	1187	if ($MODEL) {
1057	$cb->();	1188	$cb->();
1058		1189
1059	1	1190	undef
1060	} else {	1191	} else {
1061	push @post_detect, $cb;	1192	push @post_detect, $cb;
1062		1193
1063	defined wantarray	1194	defined wantarray
1064	? bless \$cb, "AnyEvent::Util::postdetect"	1195	? bless \$cb, "AnyEvent::Util::postdetect"
…		…
1070	@post_detect = grep $_ != ${$_[0]}, @post_detect;	1201	@post_detect = grep $_ != ${$_[0]}, @post_detect;
1071	}	1202	}
1072		1203
1073	sub detect() {	1204	sub detect() {
1074	unless ($MODEL) {	1205	unless ($MODEL) {
1075	no strict 'refs';
1076	local $SIG{__DIE__};	1206	local $SIG{__DIE__};
1077		1207
1078	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {	1208	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {
1079	my $model = "AnyEvent::Impl::$1";	1209	my $model = "AnyEvent::Impl::$1";
1080	if (eval "require $model") {	1210	if (eval "require $model") {
1081	$MODEL = $model;	1211	$MODEL = $model;
1082	warn "AnyEvent: loaded model '$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 $VERBOSE >= 2;
1083	} else {	1213	} else {
1084	warn "AnyEvent: unable to load model '$model' (from \$PERL_ANYEVENT_MODEL):\n$@" if $verbose;	1214	warn "AnyEvent: unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@" if $VERBOSE;
1085	}	1215	}
1086	}	1216	}
1087		1217
1088	# check for already loaded models	1218	# check for already loaded models
1089	unless ($MODEL) {	1219	unless ($MODEL) {
1090	for (@REGISTRY, @models) {	1220	for (@REGISTRY, @models) {
1091	my ($package, $model) = @$_;	1221	my ($package, $model) = @$_;
1092	if (${"$package\::VERSION"} > 0) {	1222	if (${"$package\::VERSION"} > 0) {
1093	if (eval "require $model") {	1223	if (eval "require $model") {
1094	$MODEL = $model;	1224	$MODEL = $model;
1095	warn "AnyEvent: autodetected model '$model', using it.\n" if $verbose > 1;	1225	warn "AnyEvent: autodetected model '$model', using it.\n" if $VERBOSE >= 2;
1096	last;	1226	last;
1097	}	1227	}
1098	}	1228	}
1099	}	1229	}
1100		1230
1101	unless ($MODEL) {	1231	unless ($MODEL) {
1102	# try to load a model	1232	# try to autoload a model
1103
1104	for (@REGISTRY, @models) {	1233	for (@REGISTRY, @models) {
1105	my ($package, $model) = @$_;	1234	my ($package, $model, $autoload) = @$_;
		1235	if (
		1236	$autoload
1106	if (eval "require $package"	1237	and eval "require $package"
1107	and ${"$package\::VERSION"} > 0	1238	and ${"$package\::VERSION"} > 0
1108	and eval "require $model") {	1239	and eval "require $model"
		1240	) {
1109	$MODEL = $model;	1241	$MODEL = $model;
1110	warn "AnyEvent: autoprobed model '$model', using it.\n" if $verbose > 1;	1242	warn "AnyEvent: autoloaded model '$model', using it.\n" if $VERBOSE >= 2;
1111	last;	1243	last;
1112	}	1244	}
1113	}	1245	}
1114		1246
1115	$MODEL	1247	$MODEL
…		…
1131		1263
1132	sub AUTOLOAD {	1264	sub AUTOLOAD {
1133	(my $func = $AUTOLOAD) =~ s/.*://;	1265	(my $func = $AUTOLOAD) =~ s/.*://;
1134		1266
1135	$method{$func}	1267	$method{$func}
1136	or croak "$func: not a valid method for AnyEvent objects";	1268	or Carp::croak "$func: not a valid method for AnyEvent objects";
1137		1269
1138	detect unless $MODEL;	1270	detect unless $MODEL;
1139		1271
1140	my $class = shift;	1272	my $class = shift;
1141	$class->$func (@_);	1273	$class->$func (@_);
…		…
1146	# 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).
1147	sub _dupfh($$;$$) {	1279	sub _dupfh($$;$$) {
1148	my ($poll, $fh, $r, $w) = @_;	1280	my ($poll, $fh, $r, $w) = @_;
1149		1281
1150	# cygwin requires the fh mode to be matching, unix doesn't	1282	# cygwin requires the fh mode to be matching, unix doesn't
1151	my ($rw, $mode) = $poll eq "r" ? ($r, "<")	1283	my ($rw, $mode) = $poll eq "r" ? ($r, "<&") : ($w, ">&");
1152	: $poll eq "w" ? ($w, ">")
1153	: Carp::croak "AnyEvent->io requires poll set to either 'r' or 'w'";
1154		1284
1155	open my $fh2, "$mode&" . fileno $fh	1285	open my $fh2, $mode, $fh
1156	or die "cannot dup() filehandle: $!,";	1286	or die "AnyEvent->io: cannot dup() filehandle in mode '$poll': $!,";
1157		1287
1158	# we assume CLOEXEC is already set by perl in all important cases	1288	# we assume CLOEXEC is already set by perl in all important cases
1159		1289
1160	($fh2, $rw)	1290	($fh2, $rw)
1161	}	1291	}
1162		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
1163	package AnyEvent::Base;	1343	package AnyEvent::Base;
1164		1344
1165	# default implementations for many methods	1345	# default implementations for many methods
1166		1346
1167	BEGIN {	1347	sub _time {
		1348	# probe for availability of Time::HiRes
1168	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;
1169	*_time = \&Time::HiRes::time;	1351	*_time = \&Time::HiRes::time;
1170	# if (eval "use POSIX (); (POSIX::times())...	1352	# if (eval "use POSIX (); (POSIX::times())...
1171	} else {	1353	} else {
		1354	warn "AnyEvent: using built-in time(), WARNING, no sub-second resolution!\n" if $VERBOSE;
1172	*_time = sub { time }; # epic fail	1355	*_time = sub { time }; # epic fail
1173	}	1356	}
		1357
		1358	&_time
1174	}	1359	}
1175		1360
1176	sub time { _time }	1361	sub time { _time }
1177	sub now { _time }	1362	sub now { _time }
1178	sub now_update { }	1363	sub now_update { }
…		…
1183	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"	1368	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"
1184	}	1369	}
1185		1370
1186	# default implementation for ->signal	1371	# default implementation for ->signal
1187		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	$HAVE_ASYNC_INTERRUPT
		1381	}
		1382
1188	our ($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);
1189		1386
1190	sub _signal_exec {	1387	sub _signal_exec {
		1388	$HAVE_ASYNC_INTERRUPT
		1389	? $SIGPIPE_R->drain
1191	sysread $SIGPIPE_R, my $dummy, 4;	1390	: sysread $SIGPIPE_R, my $dummy, 9;
1192		1391
1193	while (%SIG_EV) {	1392	while (%SIG_EV) {
1194	for (keys %SIG_EV) {	1393	for (keys %SIG_EV) {
1195	delete $SIG_EV{$_};	1394	delete $SIG_EV{$_};
1196	$_->() for values %{ $SIG_CB{$_} || {} };	1395	$_->() for values %{ $SIG_CB{$_} || {} };
1197	}	1396	}
1198	}	1397	}
1199	}	1398	}
1200		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
1201	sub signal {	1450	sub signal {
1202	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 $VERBOSE >= 8;
1203		1455
1204	unless ($SIGPIPE_R) {	1456	$SIGPIPE_R = new Async::Interrupt::EventPipe;
1205	require Fcntl;	1457	$SIG_IO = AE::io $SIGPIPE_R->fileno, 0, \&_signal_exec;
1206		1458
1207	if (AnyEvent::WIN32) {
1208	require AnyEvent::Util;
1209
1210	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
1211	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R) if $SIGPIPE_R;
1212	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W) if $SIGPIPE_W; # just in case
1213	} 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 {
1214	pipe $SIGPIPE_R, $SIGPIPE_W;	1471	pipe $SIGPIPE_R, $SIGPIPE_W;
1215	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;
1216	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
1217		1474
1218	# not strictly required, as $^F is normally 2, but let's make sure...	1475	# not strictly required, as $^F is normally 2, but let's make sure...
1219	fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;	1476	fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
1220	fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;	1477	fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
		1478	}
		1479
		1480	$SIGPIPE_R
		1481	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";
		1482
		1483	$SIG_IO = AE::io $SIGPIPE_R, 0, \&_signal_exec;
1221	}	1484	}
1222		1485
1223	$SIGPIPE_R	1486	*signal = sub {
1224	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";	1487	my (undef, %arg) = @_;
1225		1488
1226	$SIG_IO = AnyEvent->io (fh => $SIGPIPE_R, poll => "r", cb => \&_signal_exec);
1227	}
1228
1229	my $signal = uc $arg{signal}	1489	my $signal = uc $arg{signal}
1230	or Carp::croak "required option 'signal' is missing";	1490	or Carp::croak "required option 'signal' is missing";
1231		1491
		1492	if ($HAVE_ASYNC_INTERRUPT) {
		1493	# async::interrupt
		1494
		1495	$signal = sig2num $signal;
1232	$SIG_CB{$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
1233	$SIG{$signal} ||= sub {	1512	$SIG{$signal} ||= sub {
1234	local $!;	1513	local $!;
1235	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;	1514	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;
1236	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	};
1237	};	1541	};
1238		1542	die if $@;
1239	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"	1543	&signal
1240	}
1241
1242	sub AnyEvent::Base::signal::DESTROY {
1243	my ($signal, $cb) = @{$_[0]};
1244
1245	delete $SIG_CB{$signal}{$cb};
1246
1247	# delete doesn't work with older perls - they then
1248	# print weird messages, or just unconditionally exit
1249	# instead of getting the default action.
1250	undef $SIG{$signal} unless keys %{ $SIG_CB{$signal} };
1251	}	1544	}
1252		1545
1253	# default implementation for ->child	1546	# default implementation for ->child
1254		1547
1255	our %PID_CB;	1548	our %PID_CB;
1256	our $CHLD_W;	1549	our $CHLD_W;
1257	our $CHLD_DELAY_W;	1550	our $CHLD_DELAY_W;
1258	our $WNOHANG;	1551	our $WNOHANG;
1259		1552
		1553	sub _emit_childstatus($$) {
		1554	my (undef, $rpid, $rstatus) = @_;
		1555
		1556	$_->($rpid, $rstatus)
		1557	for values %{ $PID_CB{$rpid} || {} },
		1558	values %{ $PID_CB{0} || {} };
		1559	}
		1560
1260	sub _sigchld {	1561	sub _sigchld {
		1562	my $pid;
		1563
		1564	AnyEvent->_emit_childstatus ($pid, $?)
1261	while (0 < (my $pid = waitpid -1, $WNOHANG)) {	1565	while ($pid = waitpid -1, $WNOHANG) > 0;
1262	$_->($pid, $?) for (values %{ $PID_CB{$pid} || {} }),
1263	(values %{ $PID_CB{0} || {} });
1264	}
1265	}	1566	}
1266		1567
1267	sub child {	1568	sub child {
1268	my (undef, %arg) = @_;	1569	my (undef, %arg) = @_;
1269		1570
1270	defined (my $pid = $arg{pid} + 0)	1571	defined (my $pid = $arg{pid} + 0)
1271	or Carp::croak "required option 'pid' is missing";	1572	or Carp::croak "required option 'pid' is missing";
1272		1573
1273	$PID_CB{$pid}{$arg{cb}} = $arg{cb};	1574	$PID_CB{$pid}{$arg{cb}} = $arg{cb};
1274		1575
		1576	# WNOHANG is almost cetrainly 1 everywhere
		1577	$WNOHANG ||= $^O =~ /^(?:openbsd|netbsd|linux|freebsd|cygwin|MSWin32)$/
		1578	? 1
1275	$WNOHANG ||= eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1;	1579	: eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1;
1276		1580
1277	unless ($CHLD_W) {	1581	unless ($CHLD_W) {
1278	$CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld);	1582	$CHLD_W = AE::signal CHLD => \&_sigchld;
1279	# child could be a zombie already, so make at least one round	1583	# child could be a zombie already, so make at least one round
1280	&_sigchld;	1584	&_sigchld;
1281	}	1585	}
1282		1586
1283	bless [$pid, $arg{cb}], "AnyEvent::Base::child"	1587	bless [$pid, $arg{cb}], "AnyEvent::Base::child"
…		…
1309	# 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,
1310	# within some limits	1614	# within some limits
1311	$w = 0.0001 if $w < 0.0001;	1615	$w = 0.0001 if $w < 0.0001;
1312	$w = 5 if $w > 5;	1616	$w = 5 if $w > 5;
1313		1617
1314	$w = AnyEvent->timer (after => $w, cb => $rcb);	1618	$w = AE::timer $w, 0, $rcb;
1315	} else {	1619	} else {
1316	# clean up...	1620	# clean up...
1317	undef $w;	1621	undef $w;
1318	undef $rcb;	1622	undef $rcb;
1319	}	1623	}
1320	};	1624	};
1321		1625
1322	$w = AnyEvent->timer (after => 0.05, cb => $rcb);	1626	$w = AE::timer 0.05, 0, $rcb;
1323		1627
1324	bless \\$cb, "AnyEvent::Base::idle"	1628	bless \\$cb, "AnyEvent::Base::idle"
1325	}	1629	}
1326		1630
1327	sub AnyEvent::Base::idle::DESTROY {	1631	sub AnyEvent::Base::idle::DESTROY {
…		…
1332		1636
1333	our @ISA = AnyEvent::CondVar::Base::;	1637	our @ISA = AnyEvent::CondVar::Base::;
1334		1638
1335	package AnyEvent::CondVar::Base;	1639	package AnyEvent::CondVar::Base;
1336		1640
1337	use overload	1641	#use overload
1338	'&{}' => sub { my $self = shift; sub { $self->send (@_) } },	1642	# '&{}' => sub { my $self = shift; sub { $self->send (@_) } },
1339	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;
1340		1652
1341	sub _send {	1653	sub _send {
1342	# nop	1654	# nop
1343	}	1655	}
1344		1656
…		…
1357	sub ready {	1669	sub ready {
1358	$_[0]{_ae_sent}	1670	$_[0]{_ae_sent}
1359	}	1671	}
1360		1672
1361	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 $WAITING = 1;
1362	AnyEvent->one_event while !$_[0]{_ae_sent};	1679	AnyEvent->one_event while !$_[0]{_ae_sent};
1363	}	1680	}
1364		1681
1365	sub recv {	1682	sub recv {
1366	$_[0]->_wait;	1683	$_[0]->_wait;
…		…
1368	Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak};	1685	Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak};
1369	wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0]	1686	wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0]
1370	}	1687	}
1371		1688
1372	sub cb {	1689	sub cb {
1373	$_[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
1374	$_[0]{_ae_cb}	1697	$cv->{_ae_cb}
1375	}	1698	}
1376		1699
1377	sub begin {	1700	sub begin {
1378	++$_[0]{_ae_counter};	1701	++$_[0]{_ae_counter};
1379	$_[0]{_ae_end_cb} = $_[1] if @_ > 1;	1702	$_[0]{_ae_end_cb} = $_[1] if @_ > 1;
…		…
1428	C<PERL_ANYEVENT_MODEL>.	1751	C<PERL_ANYEVENT_MODEL>.
1429		1752
1430	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
1431	model it chooses.	1754	model it chooses.
1432		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
1433	=item C<PERL_ANYEVENT_STRICT>	1759	=item C<PERL_ANYEVENT_STRICT>
1434		1760
1435	AnyEvent does not do much argument checking by default, as thorough	1761	AnyEvent does not do much argument checking by default, as thorough
1436	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
1437	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
1438	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,
1439	it will croak.	1765	it will croak.
1440		1766
1441	In other words, enables "strict" mode.	1767	In other words, enables "strict" mode.
1442		1768
1443	Unlike C<use strict>, it is definitely recommended to keep it off in	1769	Unlike C<use strict> (or it's modern cousin, C<< use L<common::sense>
1444	production. Keeping C<PERL_ANYEVENT_STRICT=1> in your environment while	1770	>>, it is definitely recommended to keep it off in production. Keeping
1445	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.
1446		1773
1447	=item C<PERL_ANYEVENT_MODEL>	1774	=item C<PERL_ANYEVENT_MODEL>
1448		1775
1449	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
1450	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
…		…
1512		1839
1513	When neither C<ca_file> nor C<ca_path> was specified during	1840	When neither C<ca_file> nor C<ca_path> was specified during
1514	L<AnyEvent::TLS> context creation, and either of these environment	1841	L<AnyEvent::TLS> context creation, and either of these environment
1515	variables exist, they will be used to specify CA certificate locations	1842	variables exist, they will be used to specify CA certificate locations
1516	instead of a system-dependent default.	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.
1517		1849
1518	=back	1850	=back
1519		1851
1520	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE	1852	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE
1521		1853
…		…
1729	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
1730	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,
1731	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.
1732		2064
1733	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
1734	distribution.	2066	distribution. It uses the L<AE> interface, which makes a real difference
		2067	for the EV and Perl backends only.
1735		2068
1736	=head3 Explanation of the columns	2069	=head3 Explanation of the columns
1737		2070
1738	I<watcher> is the number of event watchers created/destroyed. Since	2071	I<watcher> is the number of event watchers created/destroyed. Since
1739	different event models feature vastly different performances, each event	2072	different event models feature vastly different performances, each event
…		…
1760	watcher.	2093	watcher.
1761		2094
1762	=head3 Results	2095	=head3 Results
1763		2096
1764	name watchers bytes create invoke destroy comment	2097	name watchers bytes create invoke destroy comment
1765	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
1766	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
1767	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
1768	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
1769	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
1770	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
1771	IOAsync/Any 16000 989 38.10 32.77 11.13 via IO::Async::Loop::IO_Poll	2104	IOAsync/Any 16000 1911 41.92 27.45 16.81 via IO::Async::Loop::IO_Poll
1772	IOAsync/Any 16000 990 37.59 29.50 10.61 via IO::Async::Loop::Epoll	2105	IOAsync/Any 16000 1726 40.69 26.37 15.25 via IO::Async::Loop::Epoll
1773	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
1774	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
1775	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
1776	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
1777		2110
1778	=head3 Discussion	2111	=head3 Discussion
1779		2112
1780	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
1781	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)
…		…
1793	benchmark machine, handling an event takes roughly 1600 CPU cycles with	2126	benchmark machine, handling an event takes roughly 1600 CPU cycles with
1794	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
1795	cycles with POE.	2128	cycles with POE.
1796		2129
1797	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
1798	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
1799	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).
1800	natively.
1801		2135
1802	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
1803	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
1804	interpreter and the backend itself). Nevertheless this shows that it	2138	interpreter and the backend itself). Nevertheless this shows that it
1805	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
…		…
1879	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
1880	(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
1881	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.
1882		2216
1883	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
1884	distribution.	2218	distribution. It uses the L<AE> interface, which makes a real difference
		2219	for the EV and Perl backends only.
1885		2220
1886	=head3 Explanation of the columns	2221	=head3 Explanation of the columns
1887		2222
1888	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
1889	each server has a read and write socket end).	2224	each server has a read and write socket end).
…		…
1897	a new one that moves the timeout into the future.	2232	a new one that moves the timeout into the future.
1898		2233
1899	=head3 Results	2234	=head3 Results
1900		2235
1901	name sockets create request	2236	name sockets create request
1902	EV 20000 69.01 11.16	2237	EV 20000 62.66 7.99
1903	Perl 20000 73.32 35.87	2238	Perl 20000 68.32 32.64
1904	IOAsync 20000 157.00 98.14 epoll	2239	IOAsync 20000 174.06 101.15 epoll
1905	IOAsync 20000 159.31 616.06 poll	2240	IOAsync 20000 174.67 610.84 poll
1906	Event 20000 212.62 257.32	2241	Event 20000 202.69 242.91
1907	Glib 20000 651.16 1896.30	2242	Glib 20000 557.01 1689.52
1908	POE 20000 349.67 12317.24 uses POE::Loop::Event	2243	POE 20000 341.54 12086.32 uses POE::Loop::Event
1909		2244
1910	=head3 Discussion	2245	=head3 Discussion
1911		2246
1912	This benchmark I<does> measure scalability and overall performance of the	2247	This benchmark I<does> measure scalability and overall performance of the
1913	particular event loop.	2248	particular event loop.
…		…
2060		2395
2061	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
2062	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
2063	event loops install a similar handler.	2398	event loops install a similar handler.
2064		2399
2065	If, when AnyEvent is loaded, SIGCHLD is set to IGNORE, then AnyEvent will	2400	Additionally, when AnyEvent is loaded and SIGCHLD is set to IGNORE, then
2066	reset it to default, to avoid losing child exit statuses.	2401	AnyEvent will reset it to default, to avoid losing child exit statuses.
2067		2402
2068	=item SIGPIPE	2403	=item SIGPIPE
2069		2404
2070	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>
2071	when AnyEvent gets loaded.	2406	when AnyEvent gets loaded.
…		…
2089	if $SIG{CHLD} eq 'IGNORE';	2424	if $SIG{CHLD} eq 'IGNORE';
2090		2425
2091	$SIG{PIPE} = sub { }	2426	$SIG{PIPE} = sub { }
2092	unless defined $SIG{PIPE};	2427	unless defined $SIG{PIPE};
2093		2428
		2429	=head1 RECOMMENDED/OPTIONAL MODULES
		2430
		2431	One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and
		2432	it's built-in modules) are required to use it.
		2433
		2434	That does not mean that AnyEvent won't take advantage of some additional
		2435	modules if they are installed.
		2436
		2437	This section epxlains which additional modules will be used, and how they
		2438	affect AnyEvent's operetion.
		2439
		2440	=over 4
		2441
		2442	=item L<Async::Interrupt>
		2443
		2444	This slightly arcane module is used to implement fast signal handling: To
		2445	my knowledge, there is no way to do completely race-free and quick
		2446	signal handling in pure perl. To ensure that signals still get
		2447	delivered, AnyEvent will start an interval timer to wake up perl (and
		2448	catch the signals) with some delay (default is 10 seconds, look for
		2449	C<$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
		2505
		2506
2094	=head1 FORK	2507	=head1 FORK
2095		2508
2096	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
2097	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>
2098	calls. Only L<EV> is fully fork-aware.	2511	calls. Only L<EV> is fully fork-aware.
2099		2512
2100	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
2101	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.
2102		2516
2103		2517
2104	=head1 SECURITY CONSIDERATIONS	2518	=head1 SECURITY CONSIDERATIONS
2105		2519
2106	AnyEvent can be forced to load any event model via	2520	AnyEvent can be forced to load any event model via
…		…
2144	L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.	2558	L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.
2145		2559
2146	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,	2560	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,
2147	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>,
2148	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,	2562	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,
2149	L<AnyEvent::Impl::POE>.	2563	L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>, L<Anyevent::Impl::Irssi>.
2150		2564
2151	Non-blocking file handles, sockets, TCP clients and	2565	Non-blocking file handles, sockets, TCP clients and
2152	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>.	2566	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.
2153		2567
2154	Asynchronous DNS: L<AnyEvent::DNS>.	2568	Asynchronous DNS: L<AnyEvent::DNS>.
2155		2569
2156	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>,
2157		2572
2158	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>.
2159		2575
2160		2576
2161	=head1 AUTHOR	2577	=head1 AUTHOR
2162		2578
2163	Marc Lehmann <schmorp@schmorp.de>	2579	Marc Lehmann <schmorp@schmorp.de>

Diff Legend

–	Removed lines
+	Added lines
<	Changed lines
>	Changed lines