[ViewVC] Diff of: cvs/AnyEvent/lib/AnyEvent.pm

Comparing AnyEvent/lib/AnyEvent.pm (file contents):
Revision 1.219 by root, Thu Jun 25 11:16:08 2009 UTC vs.
Revision 1.253 by root, Tue Jul 21 06:00:47 2009 UTC

…		…
1	=head1 NAME	1	=head1 NAME
2		2
3	AnyEvent - provide framework for multiple event loops	3	AnyEvent - events independent of event loop implementation
4		4
5	EV, Event, Glib, Tk, Perl, Event::Lib, Qt and POE are various supported	5	EV, Event, Glib, Tk, Perl, Event::Lib, Qt and POE are various supported
6	event loops.	6	event loops.
7		7
8	=head1 SYNOPSIS	8	=head1 SYNOPSIS
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	Respository>, 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?
…		…
176	=head2 I/O WATCHERS	184	=head2 I/O WATCHERS
177		185
178	You can create an I/O watcher by calling the C<< AnyEvent->io >> method	186	You can create an I/O watcher by calling the C<< AnyEvent->io >> method
179	with the following mandatory key-value pairs as arguments:	187	with the following mandatory key-value pairs as arguments:
180		188
181	C<fh> is the Perl I<file handle> (I<not> file descriptor) to watch	189	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	190	for events (AnyEvent might or might not keep a reference to this file
183	handle). Note that only file handles pointing to things for which	191	handle). Note that only file handles pointing to things for which
184	non-blocking operation makes sense are allowed. This includes sockets,	192	non-blocking operation makes sense are allowed. This includes sockets,
185	most character devices, pipes, fifos and so on, but not for example files	193	most character devices, pipes, fifos and so on, but not for example files
186	or block devices.	194	or block devices.
…		…
361	invocation, and callback invocation will be synchronous. Synchronous means	369	invocation, and callback invocation will be synchronous. Synchronous means
362	that it might take a while until the signal gets handled by the process,	370	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.	371	but it is guaranteed not to interrupt any other callbacks.
364		372
365	The main advantage of using these watchers is that you can share a signal	373	The main advantage of using these watchers is that you can share a signal
366	between multiple watchers.	374	between multiple watchers, and AnyEvent will ensure that signals will not
		375	interrupt your program at bad times.
367		376
368	This watcher might use C<%SIG>, so programs overwriting those signals	377	This watcher might use C<%SIG> (depending on the event loop used),
369	directly will likely not work correctly.	378	so programs overwriting those signals directly will likely not work
		379	correctly.
370		380
371	Example: exit on SIGINT	381	Example: exit on SIGINT
372		382
373	my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });	383	my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });
		384
		385	=head3 Signal Races, Delays and Workarounds
		386
		387	Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support attaching
		388	callbacks to signals in a generic way, which is a pity, as you cannot do
		389	race-free signal handling in perl. AnyEvent will try to do it's best, but
		390	in some cases, signals will be delayed. The maximum time a signal might
		391	be delayed is specified in C<$AnyEvent::MAX_SIGNAL_LATENCY> (default: 10
		392	seconds). This variable can be changed only before the first signal
		393	watcher is created, and should be left alone otherwise. Higher values
		394	will cause fewer spurious wake-ups, which is better for power and CPU
		395	saving. All these problems can be avoided by installing the optional
		396	L<Async::Interrupt> module. This will not work with inherently broken
		397	event loops such as L<Event> or L<Event::Lib> (and not with L<POE>
		398	currently, as POE does it's own workaround with one-second latency). With
		399	those, you just have to suffer the delays.
374		400
375	=head2 CHILD PROCESS WATCHERS	401	=head2 CHILD PROCESS WATCHERS
376		402
377	You can also watch on a child process exit and catch its exit status.	403	You can also watch on a child process exit and catch its exit status.
378		404
…		…
403		429
404	This means you cannot create a child watcher as the very first	430	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	431	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	432	watcher before you C<fork> the child (alternatively, you can call
407	C<AnyEvent::detect>).	433	C<AnyEvent::detect>).
		434
		435	As most event loops do not support waiting for child events, they will be
		436	emulated by AnyEvent in most cases, in which the latency and race problems
		437	mentioned in the description of signal watchers apply.
408		438
409	Example: fork a process and wait for it	439	Example: fork a process and wait for it
410		440
411	my $done = AnyEvent->condvar;	441	my $done = AnyEvent->condvar;
412		442
…		…
463		493
464	If you are familiar with some event loops you will know that all of them	494	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	495	require you to run some blocking "loop", "run" or similar function that
466	will actively watch for new events and call your callbacks.	496	will actively watch for new events and call your callbacks.
467		497
468	AnyEvent is different, it expects somebody else to run the event loop and	498	AnyEvent is slightly different: it expects somebody else to run the event
469	will only block when necessary (usually when told by the user).	499	loop and will only block when necessary (usually when told by the user).
470		500
471	The instrument to do that is called a "condition variable", so called	501	The instrument to do that is called a "condition variable", so called
472	because they represent a condition that must become true.	502	because they represent a condition that must become true.
473		503
		504	Now is probably a good time to look at the examples further below.
		505
474	Condition variables can be created by calling the C<< AnyEvent->condvar	506	Condition variables can be created by calling the C<< AnyEvent->condvar
475	>> method, usually without arguments. The only argument pair allowed is	507	>> 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	508	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	509	becomes true, with the condition variable as the first argument (but not
479	the results).	510	the results).
480		511
481	After creation, the condition variable is "false" until it becomes "true"	512	After creation, the condition variable is "false" until it becomes "true"
…		…
486	Condition variables are similar to callbacks, except that you can	517	Condition variables are similar to callbacks, except that you can
487	optionally wait for them. They can also be called merge points - points	518	optionally wait for them. They can also be called merge points - points
488	in time where multiple outstanding events have been processed. And yet	519	in time where multiple outstanding events have been processed. And yet
489	another way to call them is transactions - each condition variable can be	520	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	521	used to represent a transaction, which finishes at some point and delivers
491	a result.	522	a result. And yet some people know them as "futures" - a promise to
		523	compute/deliver something that you can wait for.
492		524
493	Condition variables are very useful to signal that something has finished,	525	Condition variables are very useful to signal that something has finished,
494	for example, if you write a module that does asynchronous http requests,	526	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	527	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	528	availability of results. The user can either act when the callback is
…		…
530	after => 1,	562	after => 1,
531	cb => sub { $result_ready->send },	563	cb => sub { $result_ready->send },
532	);	564	);
533		565
534	# this "blocks" (while handling events) till the callback	566	# this "blocks" (while handling events) till the callback
535	# calls send	567	# calls -<send
536	$result_ready->recv;	568	$result_ready->recv;
537		569
538	Example: wait for a timer, but take advantage of the fact that	570	Example: wait for a timer, but take advantage of the fact that condition
539	condition variables are also code references.	571	variables are also callable directly.
540		572
541	my $done = AnyEvent->condvar;	573	my $done = AnyEvent->condvar;
542	my $delay = AnyEvent->timer (after => 5, cb => $done);	574	my $delay = AnyEvent->timer (after => 5, cb => $done);
543	$done->recv;	575	$done->recv;
544		576
…		…
550		582
551	...	583	...
552		584
553	my @info = $couchdb->info->recv;	585	my @info = $couchdb->info->recv;
554		586
555	And this is how you would just ste a callback to be called whenever the	587	And this is how you would just set a callback to be called whenever the
556	results are available:	588	results are available:
557		589
558	$couchdb->info->cb (sub {	590	$couchdb->info->cb (sub {
559	my @info = $_[0]->recv;	591	my @info = $_[0]->recv;
560	});	592	});
…		…
578	immediately from within send.	610	immediately from within send.
579		611
580	Any arguments passed to the C<send> call will be returned by all	612	Any arguments passed to the C<send> call will be returned by all
581	future C<< ->recv >> calls.	613	future C<< ->recv >> calls.
582		614
583	Condition variables are overloaded so one can call them directly	615	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	616	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	617	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		618
592	=item $cv->croak ($error)	619	=item $cv->croak ($error)
593		620
594	Similar to send, but causes all call's to C<< ->recv >> to invoke	621	Similar to send, but causes all call's to C<< ->recv >> to invoke
595	C<Carp::croak> with the given error message/object/scalar.	622	C<Carp::croak> with the given error message/object/scalar.
596		623
597	This can be used to signal any errors to the condition variable	624	This can be used to signal any errors to the condition variable
598	user/consumer.	625	user/consumer. Doing it this way instead of calling C<croak> directly
		626	delays the error detetcion, but has the overwhelmign advantage that it
		627	diagnoses the error at the place where the result is expected, and not
		628	deep in some event clalback without connection to the actual code causing
		629	the problem.
599		630
600	=item $cv->begin ([group callback])	631	=item $cv->begin ([group callback])
601		632
602	=item $cv->end	633	=item $cv->end
603
604	These two methods are EXPERIMENTAL and MIGHT CHANGE.
605		634
606	These two methods can be used to combine many transactions/events into	635	These two methods can be used to combine many transactions/events into
607	one. For example, a function that pings many hosts in parallel might want	636	one. For example, a function that pings many hosts in parallel might want
608	to use a condition variable for the whole process.	637	to use a condition variable for the whole process.
609		638
…		…
611	C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end	640	C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end
612	>>, the (last) callback passed to C<begin> will be executed. That callback	641	>>, the (last) callback passed to C<begin> will be executed. That callback
613	is I<supposed> to call C<< ->send >>, but that is not required. If no	642	is I<supposed> to call C<< ->send >>, but that is not required. If no
614	callback was set, C<send> will be called without any arguments.	643	callback was set, C<send> will be called without any arguments.
615		644
616	Let's clarify this with the ping example:	645	You can think of C<< $cv->send >> giving you an OR condition (one call
		646	sends), while C<< $cv->begin >> and C<< $cv->end >> giving you an AND
		647	condition (all C<begin> calls must be C<end>'ed before the condvar sends).
		648
		649	Let's start with a simple example: you have two I/O watchers (for example,
		650	STDOUT and STDERR for a program), and you want to wait for both streams to
		651	close before activating a condvar:
		652
		653	my $cv = AnyEvent->condvar;
		654
		655	$cv->begin; # first watcher
		656	my $w1 = AnyEvent->io (fh => $fh1, cb => sub {
		657	defined sysread $fh1, my $buf, 4096
		658	or $cv->end;
		659	});
		660
		661	$cv->begin; # second watcher
		662	my $w2 = AnyEvent->io (fh => $fh2, cb => sub {
		663	defined sysread $fh2, my $buf, 4096
		664	or $cv->end;
		665	});
		666
		667	$cv->recv;
		668
		669	This works because for every event source (EOF on file handle), there is
		670	one call to C<begin>, so the condvar waits for all calls to C<end> before
		671	sending.
		672
		673	The ping example mentioned above is slightly more complicated, as the
		674	there are results to be passwd back, and the number of tasks that are
		675	begung can potentially be zero:
617		676
618	my $cv = AnyEvent->condvar;	677	my $cv = AnyEvent->condvar;
619		678
620	my %result;	679	my %result;
621	$cv->begin (sub { $cv->send (\%result) });	680	$cv->begin (sub { $cv->send (\%result) });
…		…
641	loop, which serves two important purposes: first, it sets the callback	700	loop, which serves two important purposes: first, it sets the callback
642	to be called once the counter reaches C<0>, and second, it ensures that	701	to be called once the counter reaches C<0>, and second, it ensures that
643	C<send> is called even when C<no> hosts are being pinged (the loop	702	C<send> is called even when C<no> hosts are being pinged (the loop
644	doesn't execute once).	703	doesn't execute once).
645		704
646	This is the general pattern when you "fan out" into multiple subrequests:	705	This is the general pattern when you "fan out" into multiple (but
647	use an outer C<begin>/C<end> pair to set the callback and ensure C<end>	706	potentially none) subrequests: use an outer C<begin>/C<end> pair to set
648	is called at least once, and then, for each subrequest you start, call	707	the callback and ensure C<end> is called at least once, and then, for each
649	C<begin> and for each subrequest you finish, call C<end>.	708	subrequest you start, call C<begin> and for each subrequest you finish,
		709	call C<end>.
650		710
651	=back	711	=back
652		712
653	=head3 METHODS FOR CONSUMERS	713	=head3 METHODS FOR CONSUMERS
654		714
…		…
670	function will call C<croak>.	730	function will call C<croak>.
671		731
672	In list context, all parameters passed to C<send> will be returned,	732	In list context, all parameters passed to C<send> will be returned,
673	in scalar context only the first one will be returned.	733	in scalar context only the first one will be returned.
674		734
		735	Note that doing a blocking wait in a callback is not supported by any
		736	event loop, that is, recursive invocation of a blocking C<< ->recv
		737	>> is not allowed, and the C<recv> call will C<croak> if such a
		738	condition is detected. This condition can be slightly loosened by using
		739	L<Coro::AnyEvent>, which allows you to do a blocking C<< ->recv >> from
		740	any thread that doesn't run the event loop itself.
		741
675	Not all event models support a blocking wait - some die in that case	742	Not all event models support a blocking wait - some die in that case
676	(programs might want to do that to stay interactive), so I<if you are	743	(programs might want to do that to stay interactive), so I<if you are
677	using this from a module, never require a blocking wait>, but let the	744	using this from a module, never require a blocking wait>. Instead, let the
678	caller decide whether the call will block or not (for example, by coupling	745	caller decide whether the call will block or not (for example, by coupling
679	condition variables with some kind of request results and supporting	746	condition variables with some kind of request results and supporting
680	callbacks so the caller knows that getting the result will not block,	747	callbacks so the caller knows that getting the result will not block,
681	while still supporting blocking waits if the caller so desires).	748	while still supporting blocking waits if the caller so desires).
682		749
683	Another reason I<never> to C<< ->recv >> in a module is that you cannot
684	sensibly have two C<< ->recv >>'s in parallel, as that would require
685	multiple interpreters or coroutines/threads, none of which C<AnyEvent>
686	can supply.
687
688	The L<Coro> module, however, I<can> and I<does> supply coroutines and, in
689	fact, L<Coro::AnyEvent> replaces AnyEvent's condvars by coroutine-safe
690	versions and also integrates coroutines into AnyEvent, making blocking
691	C<< ->recv >> calls perfectly safe as long as they are done from another
692	coroutine (one that doesn't run the event loop).
693
694	You can ensure that C<< -recv >> never blocks by setting a callback and	750	You can ensure that C<< -recv >> never blocks by setting a callback and
695	only calling C<< ->recv >> from within that callback (or at a later	751	only calling C<< ->recv >> from within that callback (or at a later
696	time). This will work even when the event loop does not support blocking	752	time). This will work even when the event loop does not support blocking
697	waits otherwise.	753	waits otherwise.
698		754
…		…
711	variable itself. Calling C<recv> inside the callback or at any later time	767	variable itself. Calling C<recv> inside the callback or at any later time
712	is guaranteed not to block.	768	is guaranteed not to block.
713		769
714	=back	770	=back
715		771
		772	=head1 SUPPORTED EVENT LOOPS/BACKENDS
		773
		774	The available backend classes are (every class has its own manpage):
		775
		776	=over 4
		777
		778	=item Backends that are autoprobed when no other event loop can be found.
		779
		780	EV is the preferred backend when no other event loop seems to be in
		781	use. If EV is not installed, then AnyEvent will try Event, and, failing
		782	that, will fall back to its own pure-perl implementation, which is
		783	available everywhere as it comes with AnyEvent itself.
		784
		785	AnyEvent::Impl::EV based on EV (interface to libev, best choice).
		786	AnyEvent::Impl::Event based on Event, very stable, few glitches.
		787	AnyEvent::Impl::Perl pure-perl implementation, fast and portable.
		788
		789	=item Backends that are transparently being picked up when they are used.
		790
		791	These will be used when they are currently loaded when the first watcher
		792	is created, in which case it is assumed that the application is using
		793	them. This means that AnyEvent will automatically pick the right backend
		794	when the main program loads an event module before anything starts to
		795	create watchers. Nothing special needs to be done by the main program.
		796
		797	AnyEvent::Impl::Glib based on Glib, slow but very stable.
		798	AnyEvent::Impl::Tk based on Tk, very broken.
		799	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
		800	AnyEvent::Impl::POE based on POE, very slow, some limitations.
		801
		802	=item Backends with special needs.
		803
		804	Qt requires the Qt::Application to be instantiated first, but will
		805	otherwise be picked up automatically. As long as the main program
		806	instantiates the application before any AnyEvent watchers are created,
		807	everything should just work.
		808
		809	AnyEvent::Impl::Qt based on Qt.
		810
		811	Support for IO::Async can only be partial, as it is too broken and
		812	architecturally limited to even support the AnyEvent API. It also
		813	is the only event loop that needs the loop to be set explicitly, so
		814	it can only be used by a main program knowing about AnyEvent. See
		815	L<AnyEvent::Impl::Async> for the gory details.
		816
		817	AnyEvent::Impl::IOAsync based on IO::Async, cannot be autoprobed.
		818
		819	=item Event loops that are indirectly supported via other backends.
		820
		821	Some event loops can be supported via other modules:
		822
		823	There is no direct support for WxWidgets (L<Wx>) or L<Prima>.
		824
		825	B<WxWidgets> has no support for watching file handles. However, you can
		826	use WxWidgets through the POE adaptor, as POE has a Wx backend that simply
		827	polls 20 times per second, which was considered to be too horrible to even
		828	consider for AnyEvent.
		829
		830	B<Prima> is not supported as nobody seems to be using it, but it has a POE
		831	backend, so it can be supported through POE.
		832
		833	AnyEvent knows about both L<Prima> and L<Wx>, however, and will try to
		834	load L<POE> when detecting them, in the hope that POE will pick them up,
		835	in which case everything will be automatic.
		836
		837	=back
		838
716	=head1 GLOBAL VARIABLES AND FUNCTIONS	839	=head1 GLOBAL VARIABLES AND FUNCTIONS
717		840
		841	These are not normally required to use AnyEvent, but can be useful to
		842	write AnyEvent extension modules.
		843
718	=over 4	844	=over 4
719		845
720	=item $AnyEvent::MODEL	846	=item $AnyEvent::MODEL
721		847
722	Contains C<undef> until the first watcher is being created. Then it	848	Contains C<undef> until the first watcher is being created, before the
		849	backend has been autodetected.
		850
723	contains the event model that is being used, which is the name of the	851	Afterwards it contains the event model that is being used, which is the
724	Perl class implementing the model. This class is usually one of the	852	name of the Perl class implementing the model. This class is usually one
725	C<AnyEvent::Impl:xxx> modules, but can be any other class in the case	853	of the C<AnyEvent::Impl:xxx> modules, but can be any other class in the
726	AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode>).	854	case AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode> it
727		855	will be C<urxvt::anyevent>).
728	The known classes so far are:
729
730	AnyEvent::Impl::EV based on EV (an interface to libev, best choice).
731	AnyEvent::Impl::Event based on Event, second best choice.
732	AnyEvent::Impl::Perl pure-perl implementation, fast and portable.
733	AnyEvent::Impl::Glib based on Glib, third-best choice.
734	AnyEvent::Impl::Tk based on Tk, very bad choice.
735	AnyEvent::Impl::Qt based on Qt, cannot be autoprobed (see its docs).
736	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
737	AnyEvent::Impl::POE based on POE, not generic enough for full support.
738
739	# warning, support for IO::Async is only partial, as it is too broken
740	# and limited toe ven support the AnyEvent API. See AnyEvent::Impl::Async.
741	AnyEvent::Impl::IOAsync based on IO::Async, cannot be autoprobed (see its docs).
742
743	There is no support for WxWidgets, as WxWidgets has no support for
744	watching file handles. However, you can use WxWidgets through the
745	POE Adaptor, as POE has a Wx backend that simply polls 20 times per
746	second, which was considered to be too horrible to even consider for
747	AnyEvent. Likewise, other POE backends can be used by AnyEvent by using
748	it's adaptor.
749
750	AnyEvent knows about L<Prima> and L<Wx> and will try to use L<POE> when
751	autodetecting them.
752		856
753	=item AnyEvent::detect	857	=item AnyEvent::detect
754		858
755	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model	859	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model
756	if necessary. You should only call this function right before you would	860	if necessary. You should only call this function right before you would
757	have created an AnyEvent watcher anyway, that is, as late as possible at	861	have created an AnyEvent watcher anyway, that is, as late as possible at
758	runtime.	862	runtime, and not e.g. while initialising of your module.
		863
		864	If you need to do some initialisation before AnyEvent watchers are
		865	created, use C<post_detect>.
759		866
760	=item $guard = AnyEvent::post_detect { BLOCK }	867	=item $guard = AnyEvent::post_detect { BLOCK }
761		868
762	Arranges for the code block to be executed as soon as the event model is	869	Arranges for the code block to be executed as soon as the event model is
763	autodetected (or immediately if this has already happened).	870	autodetected (or immediately if this has already happened).
764		871
		872	The block will be executed I<after> the actual backend has been detected
		873	(C<$AnyEvent::MODEL> is set), but I<before> any watchers have been
		874	created, so it is possible to e.g. patch C<@AnyEvent::ISA> or do
		875	other initialisations - see the sources of L<AnyEvent::Strict> or
		876	L<AnyEvent::AIO> to see how this is used.
		877
		878	The most common usage is to create some global watchers, without forcing
		879	event module detection too early, for example, L<AnyEvent::AIO> creates
		880	and installs the global L<IO::AIO> watcher in a C<post_detect> block to
		881	avoid autodetecting the event module at load time.
		882
765	If called in scalar or list context, then it creates and returns an object	883	If called in scalar or list context, then it creates and returns an object
766	that automatically removes the callback again when it is destroyed. See	884	that automatically removes the callback again when it is destroyed (or
		885	C<undef> when the hook was immediately executed). See L<AnyEvent::AIO> for
767	L<Coro::BDB> for a case where this is useful.	886	a case where this is useful.
		887
		888	Example: Create a watcher for the IO::AIO module and store it in
		889	C<$WATCHER>. Only do so after the event loop is initialised, though.
		890
		891	our WATCHER;
		892
		893	my $guard = AnyEvent::post_detect {
		894	$WATCHER = AnyEvent->io (fh => IO::AIO::poll_fileno, poll => 'r', cb => \&IO::AIO::poll_cb);
		895	};
		896
		897	# the \|\|= is important in case post_detect immediately runs the block,
		898	# as to not clobber the newly-created watcher. assigning both watcher and
		899	# post_detect guard to the same variable has the advantage of users being
		900	# able to just C<undef $WATCHER> if the watcher causes them grief.
		901
		902	$WATCHER \|\|= $guard;
768		903
769	=item @AnyEvent::post_detect	904	=item @AnyEvent::post_detect
770		905
771	If there are any code references in this array (you can C<push> to it	906	If there are any code references in this array (you can C<push> to it
772	before or after loading AnyEvent), then they will called directly after	907	before or after loading AnyEvent), then they will called directly after
773	the event loop has been chosen.	908	the event loop has been chosen.
774		909
775	You should check C<$AnyEvent::MODEL> before adding to this array, though:	910	You should check C<$AnyEvent::MODEL> before adding to this array, though:
776	if it contains a true value then the event loop has already been detected,	911	if it is defined then the event loop has already been detected, and the
777	and the array will be ignored.	912	array will be ignored.
778		913
779	Best use C<AnyEvent::post_detect { BLOCK }> instead.	914	Best use C<AnyEvent::post_detect { BLOCK }> when your application allows
		915	it,as it takes care of these details.
		916
		917	This variable is mainly useful for modules that can do something useful
		918	when AnyEvent is used and thus want to know when it is initialised, but do
		919	not need to even load it by default. This array provides the means to hook
		920	into AnyEvent passively, without loading it.
780		921
781	=back	922	=back
782		923
783	=head1 WHAT TO DO IN A MODULE	924	=head1 WHAT TO DO IN A MODULE
784		925
…		…
839		980
840		981
841	=head1 OTHER MODULES	982	=head1 OTHER MODULES
842		983
843	The following is a non-exhaustive list of additional modules that use	984	The following is a non-exhaustive list of additional modules that use
844	AnyEvent and can therefore be mixed easily with other AnyEvent modules	985	AnyEvent as a client and can therefore be mixed easily with other AnyEvent
845	in the same program. Some of the modules come with AnyEvent, some are	986	modules and other event loops in the same program. Some of the modules
846	available via CPAN.	987	come with AnyEvent, most are available via CPAN.
847		988
848	=over 4	989	=over 4
849		990
850	=item L<AnyEvent::Util>	991	=item L<AnyEvent::Util>
851		992
…		…
860		1001
861	=item L<AnyEvent::Handle>	1002	=item L<AnyEvent::Handle>
862		1003
863	Provide read and write buffers, manages watchers for reads and writes,	1004	Provide read and write buffers, manages watchers for reads and writes,
864	supports raw and formatted I/O, I/O queued and fully transparent and	1005	supports raw and formatted I/O, I/O queued and fully transparent and
865	non-blocking SSL/TLS.	1006	non-blocking SSL/TLS (via L<AnyEvent::TLS>.
866		1007
867	=item L<AnyEvent::DNS>	1008	=item L<AnyEvent::DNS>
868		1009
869	Provides rich asynchronous DNS resolver capabilities.	1010	Provides rich asynchronous DNS resolver capabilities.
870		1011
…		…
898		1039
899	=item L<AnyEvent::GPSD>	1040	=item L<AnyEvent::GPSD>
900		1041
901	A non-blocking interface to gpsd, a daemon delivering GPS information.	1042	A non-blocking interface to gpsd, a daemon delivering GPS information.
902		1043
		1044	=item L<AnyEvent::IRC>
		1045
		1046	AnyEvent based IRC client module family (replacing the older Net::IRC3).
		1047
		1048	=item L<AnyEvent::XMPP>
		1049
		1050	AnyEvent based XMPP (Jabber protocol) module family (replacing the older
		1051	Net::XMPP2>.
		1052
903	=item L<AnyEvent::IGS>	1053	=item L<AnyEvent::IGS>
904		1054
905	A non-blocking interface to the Internet Go Server protocol (used by	1055	A non-blocking interface to the Internet Go Server protocol (used by
906	L<App::IGS>).	1056	L<App::IGS>).
907		1057
908	=item L<AnyEvent::IRC>
909
910	AnyEvent based IRC client module family (replacing the older Net::IRC3).
911
912	=item L<Net::XMPP2>
913
914	AnyEvent based XMPP (Jabber protocol) module family.
915
916	=item L<Net::FCP>	1058	=item L<Net::FCP>
917		1059
918	AnyEvent-based implementation of the Freenet Client Protocol, birthplace	1060	AnyEvent-based implementation of the Freenet Client Protocol, birthplace
919	of AnyEvent.	1061	of AnyEvent.
920		1062
…		…
924		1066
925	=item L<Coro>	1067	=item L<Coro>
926		1068
927	Has special support for AnyEvent via L<Coro::AnyEvent>.	1069	Has special support for AnyEvent via L<Coro::AnyEvent>.
928		1070
929	=item L<IO::Lambda>
930
931	The lambda approach to I/O - don't ask, look there. Can use AnyEvent.
932
933	=back	1071	=back
934		1072
935	=cut	1073	=cut
936		1074
937	package AnyEvent;	1075	package AnyEvent;
938		1076
		1077	# basically a tuned-down version of common::sense
		1078	sub common_sense {
939	no warnings;	1079	# no warnings
		1080	${^WARNING_BITS} ^= ${^WARNING_BITS};
940	use strict qw(vars subs);	1081	# use strict vars subs
		1082	$^H \|= 0x00000600;
		1083	}
941		1084
		1085	BEGIN { AnyEvent::common_sense }
		1086
942	use Carp;	1087	use Carp ();
943		1088
944	our $VERSION = 4.412;	1089	our $VERSION = 4.86;
945	our $MODEL;	1090	our $MODEL;
946		1091
947	our $AUTOLOAD;	1092	our $AUTOLOAD;
948	our @ISA;	1093	our @ISA;
949		1094
950	our @REGISTRY;	1095	our @REGISTRY;
951		1096
952	our $WIN32;	1097	our $WIN32;
		1098
		1099	our $VERBOSE;
953		1100
954	BEGIN {	1101	BEGIN {
955	eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }";	1102	eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }";
956	eval "sub TAINT(){ " . (${^TAINT}*1) . " }";	1103	eval "sub TAINT(){ " . (${^TAINT}*1) . " }";
957		1104
958	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}	1105	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}
959	if ${^TAINT};	1106	if ${^TAINT};
960	}
961		1107
962	our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1;	1108	$VERBOSE = $ENV{PERL_ANYEVENT_VERBOSE}*1;
		1109
		1110	}
		1111
		1112	our $MAX_SIGNAL_LATENCY = 10;
963		1113
964	our %PROTOCOL; # (ipv4\|ipv6) => (1\|2), higher numbers are preferred	1114	our %PROTOCOL; # (ipv4\|ipv6) => (1\|2), higher numbers are preferred
965		1115
966	{	1116	{
967	my $idx;	1117	my $idx;
…		…
975	[Event:: => AnyEvent::Impl::Event::],	1125	[Event:: => AnyEvent::Impl::Event::],
976	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::],	1126	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::],
977	# everything below here will not be autoprobed	1127	# everything below here will not be autoprobed
978	# as the pureperl backend should work everywhere	1128	# as the pureperl backend should work everywhere
979	# and is usually faster	1129	# and is usually faster
980	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
981	[Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers	1130	[Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers
982	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy	1131	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
		1132	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
983	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program	1133	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program
984	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza	1134	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
985	[Wx:: => AnyEvent::Impl::POE::],	1135	[Wx:: => AnyEvent::Impl::POE::],
986	[Prima:: => AnyEvent::Impl::POE::],	1136	[Prima:: => AnyEvent::Impl::POE::],
987	# IO::Async is just too broken - we would need workaorunds for its	1137	# IO::Async is just too broken - we would need workarounds for its
988	# byzantine signal and broken child handling, among others.	1138	# byzantine signal and broken child handling, among others.
989	# IO::Async is rather hard to detect, as it doesn't have any	1139	# IO::Async is rather hard to detect, as it doesn't have any
990	# obvious default class.	1140	# obvious default class.
991	# [IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program	1141	# [IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program
992	# [IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program	1142	# [IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program
…		…
1002	my ($cb) = @_;	1152	my ($cb) = @_;
1003		1153
1004	if ($MODEL) {	1154	if ($MODEL) {
1005	$cb->();	1155	$cb->();
1006		1156
1007	1	1157	undef
1008	} else {	1158	} else {
1009	push @post_detect, $cb;	1159	push @post_detect, $cb;
1010		1160
1011	defined wantarray	1161	defined wantarray
1012	? bless \$cb, "AnyEvent::Util::postdetect"	1162	? bless \$cb, "AnyEvent::Util::postdetect"
…		…
1018	@post_detect = grep $_ != ${$_[0]}, @post_detect;	1168	@post_detect = grep $_ != ${$_[0]}, @post_detect;
1019	}	1169	}
1020		1170
1021	sub detect() {	1171	sub detect() {
1022	unless ($MODEL) {	1172	unless ($MODEL) {
1023	no strict 'refs';
1024	local $SIG{__DIE__};	1173	local $SIG{__DIE__};
1025		1174
1026	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {	1175	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {
1027	my $model = "AnyEvent::Impl::$1";	1176	my $model = "AnyEvent::Impl::$1";
1028	if (eval "require $model") {	1177	if (eval "require $model") {
1029	$MODEL = $model;	1178	$MODEL = $model;
1030	warn "AnyEvent: loaded model '$model' (forced by \$PERL_ANYEVENT_MODEL), using it.\n" if $verbose > 1;	1179	warn "AnyEvent: loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.\n" if $VERBOSE >= 2;
1031	} else {	1180	} else {
1032	warn "AnyEvent: unable to load model '$model' (from \$PERL_ANYEVENT_MODEL):\n$@" if $verbose;	1181	warn "AnyEvent: unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@" if $VERBOSE;
1033	}	1182	}
1034	}	1183	}
1035		1184
1036	# check for already loaded models	1185	# check for already loaded models
1037	unless ($MODEL) {	1186	unless ($MODEL) {
1038	for (@REGISTRY, @models) {	1187	for (@REGISTRY, @models) {
1039	my ($package, $model) = @$_;	1188	my ($package, $model) = @$_;
1040	if (${"$package\::VERSION"} > 0) {	1189	if (${"$package\::VERSION"} > 0) {
1041	if (eval "require $model") {	1190	if (eval "require $model") {
1042	$MODEL = $model;	1191	$MODEL = $model;
1043	warn "AnyEvent: autodetected model '$model', using it.\n" if $verbose > 1;	1192	warn "AnyEvent: autodetected model '$model', using it.\n" if $VERBOSE >= 2;
1044	last;	1193	last;
1045	}	1194	}
1046	}	1195	}
1047	}	1196	}
1048		1197
…		…
1053	my ($package, $model) = @$_;	1202	my ($package, $model) = @$_;
1054	if (eval "require $package"	1203	if (eval "require $package"
1055	and ${"$package\::VERSION"} > 0	1204	and ${"$package\::VERSION"} > 0
1056	and eval "require $model") {	1205	and eval "require $model") {
1057	$MODEL = $model;	1206	$MODEL = $model;
1058	warn "AnyEvent: autoprobed model '$model', using it.\n" if $verbose > 1;	1207	warn "AnyEvent: autoprobed model '$model', using it.\n" if $VERBOSE >= 2;
1059	last;	1208	last;
1060	}	1209	}
1061	}	1210	}
1062		1211
1063	$MODEL	1212	$MODEL
…		…
1079		1228
1080	sub AUTOLOAD {	1229	sub AUTOLOAD {
1081	(my $func = $AUTOLOAD) =~ s/.*://;	1230	(my $func = $AUTOLOAD) =~ s/.*://;
1082		1231
1083	$method{$func}	1232	$method{$func}
1084	or croak "$func: not a valid method for AnyEvent objects";	1233	or Carp::croak "$func: not a valid method for AnyEvent objects";
1085		1234
1086	detect unless $MODEL;	1235	detect unless $MODEL;
1087		1236
1088	my $class = shift;	1237	my $class = shift;
1089	$class->$func (@_);	1238	$class->$func (@_);
…		…
1094	# allow only one watcher per fd, so we dup it to get a different one).	1243	# allow only one watcher per fd, so we dup it to get a different one).
1095	sub _dupfh($$;$$) {	1244	sub _dupfh($$;$$) {
1096	my ($poll, $fh, $r, $w) = @_;	1245	my ($poll, $fh, $r, $w) = @_;
1097		1246
1098	# cygwin requires the fh mode to be matching, unix doesn't	1247	# cygwin requires the fh mode to be matching, unix doesn't
1099	my ($rw, $mode) = $poll eq "r" ? ($r, "<")	1248	my ($rw, $mode) = $poll eq "r" ? ($r, "<&") : ($w, ">&");
1100	: $poll eq "w" ? ($w, ">")
1101	: Carp::croak "AnyEvent->io requires poll set to either 'r' or 'w'";
1102		1249
1103	open my $fh2, "$mode&" . fileno $fh	1250	open my $fh2, $mode, $fh
1104	or die "cannot dup() filehandle: $!,";	1251	or die "AnyEvent->io: cannot dup() filehandle in mode '$poll': $!,";
1105		1252
1106	# we assume CLOEXEC is already set by perl in all important cases	1253	# we assume CLOEXEC is already set by perl in all important cases
1107		1254
1108	($fh2, $rw)	1255	($fh2, $rw)
1109	}	1256	}
1110		1257
1111	package AnyEvent::Base;	1258	package AnyEvent::Base;
1112		1259
1113	# default implementations for many methods	1260	# default implementations for many methods
1114		1261
1115	BEGIN {	1262	sub _time {
		1263	# probe for availability of Time::HiRes
1116	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {	1264	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {
		1265	warn "AnyEvent: using Time::HiRes for sub-second timing accuracy.\n" if $VERBOSE >= 8;
1117	*_time = \&Time::HiRes::time;	1266	*_time = \&Time::HiRes::time;
1118	# if (eval "use POSIX (); (POSIX::times())...	1267	# if (eval "use POSIX (); (POSIX::times())...
1119	} else {	1268	} else {
		1269	warn "AnyEvent: using built-in time(), WARNING, no sub-second resolution!\n" if $VERBOSE;
1120	*_time = sub { time }; # epic fail	1270	*_time = sub { time }; # epic fail
1121	}	1271	}
		1272
		1273	&_time
1122	}	1274	}
1123		1275
1124	sub time { _time }	1276	sub time { _time }
1125	sub now { _time }	1277	sub now { _time }
1126	sub now_update { }	1278	sub now_update { }
…		…
1131	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"	1283	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"
1132	}	1284	}
1133		1285
1134	# default implementation for ->signal	1286	# default implementation for ->signal
1135		1287
		1288	our $HAVE_ASYNC_INTERRUPT;
1136	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);	1289	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);
		1290	our (%SIG_ASY, %SIG_ASY_W);
		1291	our ($SIG_COUNT, $SIG_TW);
1137		1292
1138	sub _signal_exec {	1293	sub _signal_exec {
		1294	$HAVE_ASYNC_INTERRUPT
		1295	? $SIGPIPE_R->drain
1139	sysread $SIGPIPE_R, my $dummy, 4;	1296	: sysread $SIGPIPE_R, my $dummy, 9;
1140		1297
1141	while (%SIG_EV) {	1298	while (%SIG_EV) {
1142	for (keys %SIG_EV) {	1299	for (keys %SIG_EV) {
1143	delete $SIG_EV{$_};	1300	delete $SIG_EV{$_};
1144	$_->() for values %{ $SIG_CB{$_} \|\| {} };	1301	$_->() for values %{ $SIG_CB{$_} \|\| {} };
1145	}	1302	}
1146	}	1303	}
1147	}	1304	}
1148		1305
		1306	# install a dumym wakeupw atcher to reduce signal catching latency
		1307	sub _sig_add() {
		1308	unless ($SIG_COUNT++) {
		1309	# try to align timer on a full-second boundary, if possible
		1310	my $NOW = AnyEvent->now;
		1311
		1312	$SIG_TW = AnyEvent->timer (
		1313	after => $MAX_SIGNAL_LATENCY - ($NOW - int $NOW),
		1314	interval => $MAX_SIGNAL_LATENCY,
		1315	cb => sub { }, # just for the PERL_ASYNC_CHECK
		1316	);
		1317	}
		1318	}
		1319
		1320	sub _sig_del {
		1321	undef $SIG_TW
		1322	unless --$SIG_COUNT;
		1323	}
		1324
		1325	sub _signal {
		1326	my (undef, %arg) = @_;
		1327
		1328	my $signal = uc $arg{signal}
		1329	or Carp::croak "required option 'signal' is missing";
		1330
		1331	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
		1332
		1333	if ($HAVE_ASYNC_INTERRUPT) {
		1334	# async::interrupt
		1335
		1336	$SIG_ASY{$signal} \|\|= do {
		1337	my $asy = new Async::Interrupt
		1338	cb => sub { undef $SIG_EV{$signal} },
		1339	signal => $signal,
		1340	pipe => [$SIGPIPE_R->filenos],
		1341	;
		1342	$asy->pipe_autodrain (0);
		1343
		1344	$asy
		1345	};
		1346
		1347	} else {
		1348	# pure perl
		1349
		1350	$SIG{$signal} \|\|= sub {
		1351	local $!;
		1352	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;
		1353	undef $SIG_EV{$signal};
		1354	};
		1355
		1356	# can't do signal processing without introducing races in pure perl,
		1357	# so limit the signal latency.
		1358	_sig_add;
		1359	}
		1360
		1361	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
		1362	}
		1363
1149	sub signal {	1364	sub signal {
1150	my (undef, %arg) = @_;	1365	# probe for availability of Async::Interrupt
		1366	if (!$ENV{PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT} && eval "use Async::Interrupt 0.6 (); 1") {
		1367	warn "AnyEvent: using Async::Interrupt for race-free signal handling.\n" if $VERBOSE >= 8;
1151		1368
1152	unless ($SIGPIPE_R) {	1369	$HAVE_ASYNC_INTERRUPT = 1;
		1370	$SIGPIPE_R = new Async::Interrupt::EventPipe;
		1371	$SIG_IO = AnyEvent->io (fh => $SIGPIPE_R->fileno, poll => "r", cb => \&_signal_exec);
		1372
		1373	} else {
		1374	warn "AnyEvent: using emulated perl signal handling with latency timer.\n" if $VERBOSE >= 8;
		1375
1153	require Fcntl;	1376	require Fcntl;
1154		1377
1155	if (AnyEvent::WIN32) {	1378	if (AnyEvent::WIN32) {
1156	require AnyEvent::Util;	1379	require AnyEvent::Util;
1157		1380
…		…
1172	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";	1395	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";
1173		1396
1174	$SIG_IO = AnyEvent->io (fh => $SIGPIPE_R, poll => "r", cb => \&_signal_exec);	1397	$SIG_IO = AnyEvent->io (fh => $SIGPIPE_R, poll => "r", cb => \&_signal_exec);
1175	}	1398	}
1176		1399
1177	my $signal = uc $arg{signal}	1400	*signal = \&_signal;
1178	or Carp::croak "required option 'signal' is missing";	1401	&signal
1179
1180	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
1181	$SIG{$signal} \|\|= sub {
1182	local $!;
1183	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;
1184	undef $SIG_EV{$signal};
1185	};
1186
1187	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
1188	}	1402	}
1189		1403
1190	sub AnyEvent::Base::signal::DESTROY {	1404	sub AnyEvent::Base::signal::DESTROY {
1191	my ($signal, $cb) = @{$_[0]};	1405	my ($signal, $cb) = @{$_[0]};
1192		1406
		1407	_sig_del;
		1408
1193	delete $SIG_CB{$signal}{$cb};	1409	delete $SIG_CB{$signal}{$cb};
1194		1410
		1411	$HAVE_ASYNC_INTERRUPT
		1412	? delete $SIG_ASY{$signal}
1195	# delete doesn't work with older perls - they then	1413	: # delete doesn't work with older perls - they then
1196	# print weird messages, or just unconditionally exit	1414	# print weird messages, or just unconditionally exit
1197	# instead of getting the default action.	1415	# instead of getting the default action.
		1416	undef $SIG{$signal}
1198	undef $SIG{$signal} unless keys %{ $SIG_CB{$signal} };	1417	unless keys %{ $SIG_CB{$signal} };
1199	}	1418	}
1200		1419
1201	# default implementation for ->child	1420	# default implementation for ->child
1202		1421
1203	our %PID_CB;	1422	our %PID_CB;
…		…
1205	our $CHLD_DELAY_W;	1424	our $CHLD_DELAY_W;
1206	our $WNOHANG;	1425	our $WNOHANG;
1207		1426
1208	sub _sigchld {	1427	sub _sigchld {
1209	while (0 < (my $pid = waitpid -1, $WNOHANG)) {	1428	while (0 < (my $pid = waitpid -1, $WNOHANG)) {
		1429	$_->($pid, $?)
1210	$_->($pid, $?) for (values %{ $PID_CB{$pid} \|\| {} }),	1430	for values %{ $PID_CB{$pid} \|\| {} },
1211	(values %{ $PID_CB{0} \|\| {} });	1431	values %{ $PID_CB{0} \|\| {} };
1212	}	1432	}
1213	}	1433	}
1214		1434
1215	sub child {	1435	sub child {
1216	my (undef, %arg) = @_;	1436	my (undef, %arg) = @_;
…		…
1218	defined (my $pid = $arg{pid} + 0)	1438	defined (my $pid = $arg{pid} + 0)
1219	or Carp::croak "required option 'pid' is missing";	1439	or Carp::croak "required option 'pid' is missing";
1220		1440
1221	$PID_CB{$pid}{$arg{cb}} = $arg{cb};	1441	$PID_CB{$pid}{$arg{cb}} = $arg{cb};
1222		1442
		1443	# WNOHANG is almost cetrainly 1 everywhere
		1444	$WNOHANG \|\|= $^O =~ /^(?:openbsd\|netbsd\|linux\|freebsd\|cygwin\|MSWin32)$/
		1445	? 1
1223	$WNOHANG \|\|= eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } \|\| 1;	1446	: eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } \|\| 1;
1224		1447
1225	unless ($CHLD_W) {	1448	unless ($CHLD_W) {
1226	$CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld);	1449	$CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld);
1227	# child could be a zombie already, so make at least one round	1450	# child could be a zombie already, so make at least one round
1228	&_sigchld;	1451	&_sigchld;
…		…
1280		1503
1281	our @ISA = AnyEvent::CondVar::Base::;	1504	our @ISA = AnyEvent::CondVar::Base::;
1282		1505
1283	package AnyEvent::CondVar::Base;	1506	package AnyEvent::CondVar::Base;
1284		1507
1285	use overload	1508	#use overload
1286	'&{}' => sub { my $self = shift; sub { $self->send (@_) } },	1509	# '&{}' => sub { my $self = shift; sub { $self->send (@_) } },
1287	fallback => 1;	1510	# fallback => 1;
		1511
		1512	# save 300+ kilobytes by dirtily hardcoding overloading
		1513	${"AnyEvent::CondVar::Base::OVERLOAD"}{dummy}++; # Register with magic by touching.
		1514	*{'AnyEvent::CondVar::Base::()'} = sub { }; # "Make it findable via fetchmethod."
		1515	*{'AnyEvent::CondVar::Base::(&{}'} = sub { my $self = shift; sub { $self->send (@_) } }; # &{}
		1516	${'AnyEvent::CondVar::Base::()'} = 1; # fallback
		1517
		1518	our $WAITING;
1288		1519
1289	sub _send {	1520	sub _send {
1290	# nop	1521	# nop
1291	}	1522	}
1292		1523
…		…
1305	sub ready {	1536	sub ready {
1306	$_[0]{_ae_sent}	1537	$_[0]{_ae_sent}
1307	}	1538	}
1308		1539
1309	sub _wait {	1540	sub _wait {
		1541	$WAITING
		1542	and !$_[0]{_ae_sent}
		1543	and Carp::croak "AnyEvent::CondVar: recursive blocking wait detected";
		1544
		1545	local $WAITING = 1;
1310	AnyEvent->one_event while !$_[0]{_ae_sent};	1546	AnyEvent->one_event while !$_[0]{_ae_sent};
1311	}	1547	}
1312		1548
1313	sub recv {	1549	sub recv {
1314	$_[0]->_wait;	1550	$_[0]->_wait;
…		…
1376	C<PERL_ANYEVENT_MODEL>.	1612	C<PERL_ANYEVENT_MODEL>.
1377		1613
1378	When set to C<2> or higher, cause AnyEvent to report to STDERR which event	1614	When set to C<2> or higher, cause AnyEvent to report to STDERR which event
1379	model it chooses.	1615	model it chooses.
1380		1616
		1617	When set to C<8> or higher, then AnyEvent will report extra information on
		1618	which optional modules it loads and how it implements certain features.
		1619
1381	=item C<PERL_ANYEVENT_STRICT>	1620	=item C<PERL_ANYEVENT_STRICT>
1382		1621
1383	AnyEvent does not do much argument checking by default, as thorough	1622	AnyEvent does not do much argument checking by default, as thorough
1384	argument checking is very costly. Setting this variable to a true value	1623	argument checking is very costly. Setting this variable to a true value
1385	will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly	1624	will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly
1386	check the arguments passed to most method calls. If it finds any problems,	1625	check the arguments passed to most method calls. If it finds any problems,
1387	it will croak.	1626	it will croak.
1388		1627
1389	In other words, enables "strict" mode.	1628	In other words, enables "strict" mode.
1390		1629
1391	Unlike C<use strict>, it is definitely recommended to keep it off in	1630	Unlike C<use strict> (or it's modern cousin, C<< use L<common::sense>
1392	production. Keeping C<PERL_ANYEVENT_STRICT=1> in your environment while	1631	>>, it is definitely recommended to keep it off in production. Keeping
1393	developing programs can be very useful, however.	1632	C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs
		1633	can be very useful, however.
1394		1634
1395	=item C<PERL_ANYEVENT_MODEL>	1635	=item C<PERL_ANYEVENT_MODEL>
1396		1636
1397	This can be used to specify the event model to be used by AnyEvent, before	1637	This can be used to specify the event model to be used by AnyEvent, before
1398	auto detection and -probing kicks in. It must be a string consisting	1638	auto detection and -probing kicks in. It must be a string consisting
…		…
1441		1681
1442	=item C<PERL_ANYEVENT_MAX_FORKS>	1682	=item C<PERL_ANYEVENT_MAX_FORKS>
1443		1683
1444	The maximum number of child processes that C<AnyEvent::Util::fork_call>	1684	The maximum number of child processes that C<AnyEvent::Util::fork_call>
1445	will create in parallel.	1685	will create in parallel.
		1686
		1687	=item C<PERL_ANYEVENT_MAX_OUTSTANDING_DNS>
		1688
		1689	The default value for the C<max_outstanding> parameter for the default DNS
		1690	resolver - this is the maximum number of parallel DNS requests that are
		1691	sent to the DNS server.
		1692
		1693	=item C<PERL_ANYEVENT_RESOLV_CONF>
		1694
		1695	The file to use instead of F</etc/resolv.conf> (or OS-specific
		1696	configuration) in the default resolver. When set to the empty string, no
		1697	default config will be used.
		1698
		1699	=item C<PERL_ANYEVENT_CA_FILE>, C<PERL_ANYEVENT_CA_PATH>.
		1700
		1701	When neither C<ca_file> nor C<ca_path> was specified during
		1702	L<AnyEvent::TLS> context creation, and either of these environment
		1703	variables exist, they will be used to specify CA certificate locations
		1704	instead of a system-dependent default.
		1705
		1706	=item C<PERL_ANYEVENT_AVOID_GUARD> and C<PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT>
		1707
		1708	When these are set to C<1>, then the respective modules are not
		1709	loaded. Mostly good for testing AnyEvent itself.
1446		1710
1447	=back	1711	=back
1448		1712
1449	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE	1713	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE
1450		1714
…		…
1695	EV/Any 100000 224 2.88 0.34 0.27 EV + AnyEvent watchers	1959	EV/Any 100000 224 2.88 0.34 0.27 EV + AnyEvent watchers
1696	CoroEV/Any 100000 224 2.85 0.35 0.28 coroutines + Coro::Signal	1960	CoroEV/Any 100000 224 2.85 0.35 0.28 coroutines + Coro::Signal
1697	Perl/Any 100000 452 4.13 0.73 0.95 pure perl implementation	1961	Perl/Any 100000 452 4.13 0.73 0.95 pure perl implementation
1698	Event/Event 16000 517 32.20 31.80 0.81 Event native interface	1962	Event/Event 16000 517 32.20 31.80 0.81 Event native interface
1699	Event/Any 16000 590 35.85 31.55 1.06 Event + AnyEvent watchers	1963	Event/Any 16000 590 35.85 31.55 1.06 Event + AnyEvent watchers
		1964	IOAsync/Any 16000 989 38.10 32.77 11.13 via IO::Async::Loop::IO_Poll
		1965	IOAsync/Any 16000 990 37.59 29.50 10.61 via IO::Async::Loop::Epoll
1700	Glib/Any 16000 1357 102.33 12.31 51.00 quadratic behaviour	1966	Glib/Any 16000 1357 102.33 12.31 51.00 quadratic behaviour
1701	Tk/Any 2000 1860 27.20 66.31 14.00 SEGV with >> 2000 watchers	1967	Tk/Any 2000 1860 27.20 66.31 14.00 SEGV with >> 2000 watchers
1702	POE/Event 2000 6328 109.99 751.67 14.02 via POE::Loop::Event	1968	POE/Event 2000 6328 109.99 751.67 14.02 via POE::Loop::Event
1703	POE/Select 2000 6027 94.54 809.13 579.80 via POE::Loop::Select	1969	POE/Select 2000 6027 94.54 809.13 579.80 via POE::Loop::Select
1704		1970
…		…
1733	performance becomes really bad with lots of file descriptors (and few of	1999	performance becomes really bad with lots of file descriptors (and few of
1734	them active), of course, but this was not subject of this benchmark.	2000	them active), of course, but this was not subject of this benchmark.
1735		2001
1736	The C<Event> module has a relatively high setup and callback invocation	2002	The C<Event> module has a relatively high setup and callback invocation
1737	cost, but overall scores in on the third place.	2003	cost, but overall scores in on the third place.
		2004
		2005	C<IO::Async> performs admirably well, about on par with C<Event>, even
		2006	when using its pure perl backend.
1738		2007
1739	C<Glib>'s memory usage is quite a bit higher, but it features a	2008	C<Glib>'s memory usage is quite a bit higher, but it features a
1740	faster callback invocation and overall ends up in the same class as	2009	faster callback invocation and overall ends up in the same class as
1741	C<Event>. However, Glib scales extremely badly, doubling the number of	2010	C<Event>. However, Glib scales extremely badly, doubling the number of
1742	watchers increases the processing time by more than a factor of four,	2011	watchers increases the processing time by more than a factor of four,
…		…
1820	it to another server. This includes deleting the old timeout and creating	2089	it to another server. This includes deleting the old timeout and creating
1821	a new one that moves the timeout into the future.	2090	a new one that moves the timeout into the future.
1822		2091
1823	=head3 Results	2092	=head3 Results
1824		2093
1825	name sockets create request	2094	name sockets create request
1826	EV 20000 69.01 11.16	2095	EV 20000 69.01 11.16
1827	Perl 20000 73.32 35.87	2096	Perl 20000 73.32 35.87
		2097	IOAsync 20000 157.00 98.14 epoll
		2098	IOAsync 20000 159.31 616.06 poll
1828	Event 20000 212.62 257.32	2099	Event 20000 212.62 257.32
1829	Glib 20000 651.16 1896.30	2100	Glib 20000 651.16 1896.30
1830	POE 20000 349.67 12317.24 uses POE::Loop::Event	2101	POE 20000 349.67 12317.24 uses POE::Loop::Event
1831		2102
1832	=head3 Discussion	2103	=head3 Discussion
1833		2104
1834	This benchmark I<does> measure scalability and overall performance of the	2105	This benchmark I<does> measure scalability and overall performance of the
1835	particular event loop.	2106	particular event loop.
…		…
1837	EV is again fastest. Since it is using epoll on my system, the setup time	2108	EV is again fastest. Since it is using epoll on my system, the setup time
1838	is relatively high, though.	2109	is relatively high, though.
1839		2110
1840	Perl surprisingly comes second. It is much faster than the C-based event	2111	Perl surprisingly comes second. It is much faster than the C-based event
1841	loops Event and Glib.	2112	loops Event and Glib.
		2113
		2114	IO::Async performs very well when using its epoll backend, and still quite
		2115	good compared to Glib when using its pure perl backend.
1842		2116
1843	Event suffers from high setup time as well (look at its code and you will	2117	Event suffers from high setup time as well (look at its code and you will
1844	understand why). Callback invocation also has a high overhead compared to	2118	understand why). Callback invocation also has a high overhead compared to
1845	the C<< $_->() for .. >>-style loop that the Perl event loop uses. Event	2119	the C<< $_->() for .. >>-style loop that the Perl event loop uses. Event
1846	uses select or poll in basically all documented configurations.	2120	uses select or poll in basically all documented configurations.
…		…
1979		2253
1980	A handler for C<SIGCHLD> is installed by AnyEvent's child watcher	2254	A handler for C<SIGCHLD> is installed by AnyEvent's child watcher
1981	emulation for event loops that do not support them natively. Also, some	2255	emulation for event loops that do not support them natively. Also, some
1982	event loops install a similar handler.	2256	event loops install a similar handler.
1983		2257
1984	If, when AnyEvent is loaded, SIGCHLD is set to IGNORE, then AnyEvent will	2258	Additionally, when AnyEvent is loaded and SIGCHLD is set to IGNORE, then
1985	reset it to default, to avoid losing child exit statuses.	2259	AnyEvent will reset it to default, to avoid losing child exit statuses.
1986		2260
1987	=item SIGPIPE	2261	=item SIGPIPE
1988		2262
1989	A no-op handler is installed for C<SIGPIPE> when C<$SIG{PIPE}> is C<undef>	2263	A no-op handler is installed for C<SIGPIPE> when C<$SIG{PIPE}> is C<undef>
1990	when AnyEvent gets loaded.	2264	when AnyEvent gets loaded.
…		…
2008	if $SIG{CHLD} eq 'IGNORE';	2282	if $SIG{CHLD} eq 'IGNORE';
2009		2283
2010	$SIG{PIPE} = sub { }	2284	$SIG{PIPE} = sub { }
2011	unless defined $SIG{PIPE};	2285	unless defined $SIG{PIPE};
2012		2286
		2287	=head1 RECOMMENDED/OPTIONAL MODULES
		2288
		2289	One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and
		2290	it's built-in modules) are required to use it.
		2291
		2292	That does not mean that AnyEvent won't take advantage of some additional
		2293	modules if they are installed.
		2294
		2295	This section epxlains which additional modules will be used, and how they
		2296	affect AnyEvent's operetion.
		2297
		2298	=over 4
		2299
		2300	=item L<Async::Interrupt>
		2301
		2302	This slightly arcane module is used to implement fast signal handling: To
		2303	my knowledge, there is no way to do completely race-free and quick
		2304	signal handling in pure perl. To ensure that signals still get
		2305	delivered, AnyEvent will start an interval timer to wake up perl (and
		2306	catch the signals) with some delay (default is 10 seconds, look for
		2307	C<$AnyEvent::MAX_SIGNAL_LATENCY>).
		2308
		2309	If this module is available, then it will be used to implement signal
		2310	catching, which means that signals will not be delayed, and the event loop
		2311	will not be interrupted regularly, which is more efficient (And good for
		2312	battery life on laptops).
		2313
		2314	This affects not just the pure-perl event loop, but also other event loops
		2315	that have no signal handling on their own (e.g. Glib, Tk, Qt).
		2316
		2317	Some event loops (POE, Event, Event::Lib) offer signal watchers natively,
		2318	and either employ their own workarounds (POE) or use AnyEvent's workaround
		2319	(using C<$AnyEvent::MAX_SIGNAL_LATENCY>). Installing L<Async::Interrupt>
		2320	does nothing for those backends.
		2321
		2322	=item L<EV>
		2323
		2324	This module isn't really "optional", as it is simply one of the backend
		2325	event loops that AnyEvent can use. However, it is simply the best event
		2326	loop available in terms of features, speed and stability: It supports
		2327	the AnyEvent API optimally, implements all the watcher types in XS, does
		2328	automatic timer adjustments even when no monotonic clock is available,
		2329	can take avdantage of advanced kernel interfaces such as C<epoll> and
		2330	C<kqueue>, and is the fastest backend I<by far>. You can even embed
		2331	L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>).
		2332
		2333	=item L<Guard>
		2334
		2335	The guard module, when used, will be used to implement
		2336	C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a
		2337	lot less memory), but otherwise doesn't affect guard operation much. It is
		2338	purely used for performance.
		2339
		2340	=item L<JSON> and L<JSON::XS>
		2341
		2342	This module is required when you want to read or write JSON data via
		2343	L<AnyEvent::Handle>. It is also written in pure-perl, but can take
		2344	advantage of the ultra-high-speed L<JSON::XS> module when it is installed.
		2345
		2346	In fact, L<AnyEvent::Handle> will use L<JSON::XS> by default if it is
		2347	installed.
		2348
		2349	=item L<Net::SSLeay>
		2350
		2351	Implementing TLS/SSL in Perl is certainly interesting, but not very
		2352	worthwhile: If this module is installed, then L<AnyEvent::Handle> (with
		2353	the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL.
		2354
		2355	=item L<Time::HiRes>
		2356
		2357	This module is part of perl since release 5.008. It will be used when the
		2358	chosen event library does not come with a timing source on it's own. The
		2359	pure-perl event loop (L<AnyEvent::Impl::Perl>) will additionally use it to
		2360	try to use a monotonic clock for timing stability.
		2361
		2362	=back
		2363
		2364
2013	=head1 FORK	2365	=head1 FORK
2014		2366
2015	Most event libraries are not fork-safe. The ones who are usually are	2367	Most event libraries are not fork-safe. The ones who are usually are
2016	because they rely on inefficient but fork-safe C<select> or C<poll>	2368	because they rely on inefficient but fork-safe C<select> or C<poll>
2017	calls. Only L<EV> is fully fork-aware.	2369	calls. Only L<EV> is fully fork-aware.
2018		2370
2019	If you have to fork, you must either do so I<before> creating your first	2371	If you have to fork, you must either do so I<before> creating your first
2020	watcher OR you must not use AnyEvent at all in the child.	2372	watcher OR you must not use AnyEvent at all in the child OR you must do
		2373	something completely out of the scope of AnyEvent.
2021		2374
2022		2375
2023	=head1 SECURITY CONSIDERATIONS	2376	=head1 SECURITY CONSIDERATIONS
2024		2377
2025	AnyEvent can be forced to load any event model via	2378	AnyEvent can be forced to load any event model via
…		…
2063	L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.	2416	L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.
2064		2417
2065	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,	2418	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,
2066	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,	2419	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,
2067	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,	2420	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,
2068	L<AnyEvent::Impl::POE>.	2421	L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>.
2069		2422
2070	Non-blocking file handles, sockets, TCP clients and	2423	Non-blocking file handles, sockets, TCP clients and
2071	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>.	2424	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.
2072		2425
2073	Asynchronous DNS: L<AnyEvent::DNS>.	2426	Asynchronous DNS: L<AnyEvent::DNS>.
2074		2427
2075	Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>,	2428	Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>,
		2429	L<Coro::Event>,
2076		2430
2077	Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>, L<AnyEvent::DNS>.	2431	Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::XMPP>,
		2432	L<AnyEvent::HTTP>.
2078		2433
2079		2434
2080	=head1 AUTHOR	2435	=head1 AUTHOR
2081		2436
2082	Marc Lehmann <schmorp@schmorp.de>	2437	Marc Lehmann <schmorp@schmorp.de>

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Comparing AnyEvent/lib/AnyEvent.pm (file contents): Revision 1.219 by root, Thu Jun 25 11:16:08 2009 UTC vs. Revision 1.253 by root, Tue Jul 21 06:00:47 2009 UTC

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Comparing AnyEvent/lib/AnyEvent.pm (file contents):
Revision 1.219 by root, Thu Jun 25 11:16:08 2009 UTC vs.
Revision 1.253 by root, Tue Jul 21 06:00:47 2009 UTC