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

Comparing AnyEvent/lib/AnyEvent.pm (file contents):
Revision 1.218 by root, Wed Jun 24 10:03:42 2009 UTC vs.
Revision 1.241 by root, Fri Jul 17 18:08:35 2009 UTC

…		…
176	=head2 I/O WATCHERS	176	=head2 I/O WATCHERS
177		177
178	You can create an I/O watcher by calling the C<< AnyEvent->io >> method	178	You can create an I/O watcher by calling the C<< AnyEvent->io >> method
179	with the following mandatory key-value pairs as arguments:	179	with the following mandatory key-value pairs as arguments:
180		180
181	C<fh> is the Perl I<file handle> (I<not> file descriptor) to watch	181	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	182	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	183	handle). Note that only file handles pointing to things for which
184	non-blocking operation makes sense are allowed. This includes sockets,	184	non-blocking operation makes sense are allowed. This includes sockets,
185	most character devices, pipes, fifos and so on, but not for example files	185	most character devices, pipes, fifos and so on, but not for example files
186	or block devices.	186	or block devices.
…		…
392		392
393	There is a slight catch to child watchers, however: you usually start them	393	There is a slight catch to child watchers, however: you usually start them
394	I<after> the child process was created, and this means the process could	394	I<after> the child process was created, and this means the process could
395	have exited already (and no SIGCHLD will be sent anymore).	395	have exited already (and no SIGCHLD will be sent anymore).
396		396
397	Not all event models handle this correctly (POE doesn't), but even for	397	Not all event models handle this correctly (neither POE nor IO::Async do,
		398	see their AnyEvent::Impl manpages for details), but even for event models
398	event models that I<do> handle this correctly, they usually need to be	399	that I<do> handle this correctly, they usually need to be loaded before
399	loaded before the process exits (i.e. before you fork in the first place).	400	the process exits (i.e. before you fork in the first place). AnyEvent's
		401	pure perl event loop handles all cases correctly regardless of when you
		402	start the watcher.
400		403
401	This means you cannot create a child watcher as the very first thing in an	404	This means you cannot create a child watcher as the very first
402	AnyEvent program, you I<have> to create at least one watcher before you	405	thing in an AnyEvent program, you I<have> to create at least one
403	C<fork> the child (alternatively, you can call C<AnyEvent::detect>).	406	watcher before you C<fork> the child (alternatively, you can call
		407	C<AnyEvent::detect>).
404		408
405	Example: fork a process and wait for it	409	Example: fork a process and wait for it
406		410
407	my $done = AnyEvent->condvar;	411	my $done = AnyEvent->condvar;
408		412
…		…
459		463
460	If you are familiar with some event loops you will know that all of them	464	If you are familiar with some event loops you will know that all of them
461	require you to run some blocking "loop", "run" or similar function that	465	require you to run some blocking "loop", "run" or similar function that
462	will actively watch for new events and call your callbacks.	466	will actively watch for new events and call your callbacks.
463		467
464	AnyEvent is different, it expects somebody else to run the event loop and	468	AnyEvent is slightly different: it expects somebody else to run the event
465	will only block when necessary (usually when told by the user).	469	loop and will only block when necessary (usually when told by the user).
466		470
467	The instrument to do that is called a "condition variable", so called	471	The instrument to do that is called a "condition variable", so called
468	because they represent a condition that must become true.	472	because they represent a condition that must become true.
469		473
		474	Now is probably a good time to look at the examples further below.
		475
470	Condition variables can be created by calling the C<< AnyEvent->condvar	476	Condition variables can be created by calling the C<< AnyEvent->condvar
471	>> method, usually without arguments. The only argument pair allowed is	477	>> method, usually without arguments. The only argument pair allowed is
472
473	C<cb>, which specifies a callback to be called when the condition variable	478	C<cb>, which specifies a callback to be called when the condition variable
474	becomes true, with the condition variable as the first argument (but not	479	becomes true, with the condition variable as the first argument (but not
475	the results).	480	the results).
476		481
477	After creation, the condition variable is "false" until it becomes "true"	482	After creation, the condition variable is "false" until it becomes "true"
…		…
526	after => 1,	531	after => 1,
527	cb => sub { $result_ready->send },	532	cb => sub { $result_ready->send },
528	);	533	);
529		534
530	# this "blocks" (while handling events) till the callback	535	# this "blocks" (while handling events) till the callback
531	# calls send	536	# calls -<send
532	$result_ready->recv;	537	$result_ready->recv;
533		538
534	Example: wait for a timer, but take advantage of the fact that	539	Example: wait for a timer, but take advantage of the fact that condition
535	condition variables are also code references.	540	variables are also callable directly.
536		541
537	my $done = AnyEvent->condvar;	542	my $done = AnyEvent->condvar;
538	my $delay = AnyEvent->timer (after => 5, cb => $done);	543	my $delay = AnyEvent->timer (after => 5, cb => $done);
539	$done->recv;	544	$done->recv;
540		545
…		…
546		551
547	...	552	...
548		553
549	my @info = $couchdb->info->recv;	554	my @info = $couchdb->info->recv;
550		555
551	And this is how you would just ste a callback to be called whenever the	556	And this is how you would just set a callback to be called whenever the
552	results are available:	557	results are available:
553		558
554	$couchdb->info->cb (sub {	559	$couchdb->info->cb (sub {
555	my @info = $_[0]->recv;	560	my @info = $_[0]->recv;
556	});	561	});
…		…
574	immediately from within send.	579	immediately from within send.
575		580
576	Any arguments passed to the C<send> call will be returned by all	581	Any arguments passed to the C<send> call will be returned by all
577	future C<< ->recv >> calls.	582	future C<< ->recv >> calls.
578		583
579	Condition variables are overloaded so one can call them directly	584	Condition variables are overloaded so one can call them directly (as if
580	(as a code reference). Calling them directly is the same as calling	585	they were a code reference). Calling them directly is the same as calling
581	C<send>. Note, however, that many C-based event loops do not handle	586	C<send>.
582	overloading, so as tempting as it may be, passing a condition variable
583	instead of a callback does not work. Both the pure perl and EV loops
584	support overloading, however, as well as all functions that use perl to
585	invoke a callback (as in L<AnyEvent::Socket> and L<AnyEvent::DNS> for
586	example).
587		587
588	=item $cv->croak ($error)	588	=item $cv->croak ($error)
589		589
590	Similar to send, but causes all call's to C<< ->recv >> to invoke	590	Similar to send, but causes all call's to C<< ->recv >> to invoke
591	C<Carp::croak> with the given error message/object/scalar.	591	C<Carp::croak> with the given error message/object/scalar.
592		592
593	This can be used to signal any errors to the condition variable	593	This can be used to signal any errors to the condition variable
594	user/consumer.	594	user/consumer. Doing it this way instead of calling C<croak> directly
		595	delays the error detetcion, but has the overwhelmign advantage that it
		596	diagnoses the error at the place where the result is expected, and not
		597	deep in some event clalback without connection to the actual code causing
		598	the problem.
595		599
596	=item $cv->begin ([group callback])	600	=item $cv->begin ([group callback])
597		601
598	=item $cv->end	602	=item $cv->end
599
600	These two methods are EXPERIMENTAL and MIGHT CHANGE.
601		603
602	These two methods can be used to combine many transactions/events into	604	These two methods can be used to combine many transactions/events into
603	one. For example, a function that pings many hosts in parallel might want	605	one. For example, a function that pings many hosts in parallel might want
604	to use a condition variable for the whole process.	606	to use a condition variable for the whole process.
605		607
…		…
607	C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end	609	C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end
608	>>, the (last) callback passed to C<begin> will be executed. That callback	610	>>, the (last) callback passed to C<begin> will be executed. That callback
609	is I<supposed> to call C<< ->send >>, but that is not required. If no	611	is I<supposed> to call C<< ->send >>, but that is not required. If no
610	callback was set, C<send> will be called without any arguments.	612	callback was set, C<send> will be called without any arguments.
611		613
612	Let's clarify this with the ping example:	614	You can think of C<< $cv->send >> giving you an OR condition (one call
		615	sends), while C<< $cv->begin >> and C<< $cv->end >> giving you an AND
		616	condition (all C<begin> calls must be C<end>'ed before the condvar sends).
		617
		618	Let's start with a simple example: you have two I/O watchers (for example,
		619	STDOUT and STDERR for a program), and you want to wait for both streams to
		620	close before activating a condvar:
		621
		622	my $cv = AnyEvent->condvar;
		623
		624	$cv->begin; # first watcher
		625	my $w1 = AnyEvent->io (fh => $fh1, cb => sub {
		626	defined sysread $fh1, my $buf, 4096
		627	or $cv->end;
		628	});
		629
		630	$cv->begin; # second watcher
		631	my $w2 = AnyEvent->io (fh => $fh2, cb => sub {
		632	defined sysread $fh2, my $buf, 4096
		633	or $cv->end;
		634	});
		635
		636	$cv->recv;
		637
		638	This works because for every event source (EOF on file handle), there is
		639	one call to C<begin>, so the condvar waits for all calls to C<end> before
		640	sending.
		641
		642	The ping example mentioned above is slightly more complicated, as the
		643	there are results to be passwd back, and the number of tasks that are
		644	begung can potentially be zero:
613		645
614	my $cv = AnyEvent->condvar;	646	my $cv = AnyEvent->condvar;
615		647
616	my %result;	648	my %result;
617	$cv->begin (sub { $cv->send (\%result) });	649	$cv->begin (sub { $cv->send (\%result) });
…		…
637	loop, which serves two important purposes: first, it sets the callback	669	loop, which serves two important purposes: first, it sets the callback
638	to be called once the counter reaches C<0>, and second, it ensures that	670	to be called once the counter reaches C<0>, and second, it ensures that
639	C<send> is called even when C<no> hosts are being pinged (the loop	671	C<send> is called even when C<no> hosts are being pinged (the loop
640	doesn't execute once).	672	doesn't execute once).
641		673
642	This is the general pattern when you "fan out" into multiple subrequests:	674	This is the general pattern when you "fan out" into multiple (but
643	use an outer C<begin>/C<end> pair to set the callback and ensure C<end>	675	potentially none) subrequests: use an outer C<begin>/C<end> pair to set
644	is called at least once, and then, for each subrequest you start, call	676	the callback and ensure C<end> is called at least once, and then, for each
645	C<begin> and for each subrequest you finish, call C<end>.	677	subrequest you start, call C<begin> and for each subrequest you finish,
		678	call C<end>.
646		679
647	=back	680	=back
648		681
649	=head3 METHODS FOR CONSUMERS	682	=head3 METHODS FOR CONSUMERS
650		683
…		…
666	function will call C<croak>.	699	function will call C<croak>.
667		700
668	In list context, all parameters passed to C<send> will be returned,	701	In list context, all parameters passed to C<send> will be returned,
669	in scalar context only the first one will be returned.	702	in scalar context only the first one will be returned.
670		703
		704	Note that doing a blocking wait in a callback is not supported by any
		705	event loop, that is, recursive invocation of a blocking C<< ->recv
		706	>> is not allowed, and the C<recv> call will C<croak> if such a
		707	condition is detected. This condition can be slightly loosened by using
		708	L<Coro::AnyEvent>, which allows you to do a blocking C<< ->recv >> from
		709	any thread that doesn't run the event loop itself.
		710
671	Not all event models support a blocking wait - some die in that case	711	Not all event models support a blocking wait - some die in that case
672	(programs might want to do that to stay interactive), so I<if you are	712	(programs might want to do that to stay interactive), so I<if you are
673	using this from a module, never require a blocking wait>, but let the	713	using this from a module, never require a blocking wait>. Instead, let the
674	caller decide whether the call will block or not (for example, by coupling	714	caller decide whether the call will block or not (for example, by coupling
675	condition variables with some kind of request results and supporting	715	condition variables with some kind of request results and supporting
676	callbacks so the caller knows that getting the result will not block,	716	callbacks so the caller knows that getting the result will not block,
677	while still supporting blocking waits if the caller so desires).	717	while still supporting blocking waits if the caller so desires).
678		718
679	Another reason I<never> to C<< ->recv >> in a module is that you cannot
680	sensibly have two C<< ->recv >>'s in parallel, as that would require
681	multiple interpreters or coroutines/threads, none of which C<AnyEvent>
682	can supply.
683
684	The L<Coro> module, however, I<can> and I<does> supply coroutines and, in
685	fact, L<Coro::AnyEvent> replaces AnyEvent's condvars by coroutine-safe
686	versions and also integrates coroutines into AnyEvent, making blocking
687	C<< ->recv >> calls perfectly safe as long as they are done from another
688	coroutine (one that doesn't run the event loop).
689
690	You can ensure that C<< -recv >> never blocks by setting a callback and	719	You can ensure that C<< -recv >> never blocks by setting a callback and
691	only calling C<< ->recv >> from within that callback (or at a later	720	only calling C<< ->recv >> from within that callback (or at a later
692	time). This will work even when the event loop does not support blocking	721	time). This will work even when the event loop does not support blocking
693	waits otherwise.	722	waits otherwise.
694		723
…		…
707	variable itself. Calling C<recv> inside the callback or at any later time	736	variable itself. Calling C<recv> inside the callback or at any later time
708	is guaranteed not to block.	737	is guaranteed not to block.
709		738
710	=back	739	=back
711		740
		741	=head1 SUPPORTED EVENT LOOPS/BACKENDS
		742
		743	The available backend classes are (every class has its own manpage):
		744
		745	=over 4
		746
		747	=item Backends that are autoprobed when no other event loop can be found.
		748
		749	EV is the preferred backend when no other event loop seems to be in
		750	use. If EV is not installed, then AnyEvent will try Event, and, failing
		751	that, will fall back to its own pure-perl implementation, which is
		752	available everywhere as it comes with AnyEvent itself.
		753
		754	AnyEvent::Impl::EV based on EV (interface to libev, best choice).
		755	AnyEvent::Impl::Event based on Event, very stable, few glitches.
		756	AnyEvent::Impl::Perl pure-perl implementation, fast and portable.
		757
		758	=item Backends that are transparently being picked up when they are used.
		759
		760	These will be used when they are currently loaded when the first watcher
		761	is created, in which case it is assumed that the application is using
		762	them. This means that AnyEvent will automatically pick the right backend
		763	when the main program loads an event module before anything starts to
		764	create watchers. Nothing special needs to be done by the main program.
		765
		766	AnyEvent::Impl::Glib based on Glib, slow but very stable.
		767	AnyEvent::Impl::Tk based on Tk, very broken.
		768	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
		769	AnyEvent::Impl::POE based on POE, very slow, some limitations.
		770
		771	=item Backends with special needs.
		772
		773	Qt requires the Qt::Application to be instantiated first, but will
		774	otherwise be picked up automatically. As long as the main program
		775	instantiates the application before any AnyEvent watchers are created,
		776	everything should just work.
		777
		778	AnyEvent::Impl::Qt based on Qt.
		779
		780	Support for IO::Async can only be partial, as it is too broken and
		781	architecturally limited to even support the AnyEvent API. It also
		782	is the only event loop that needs the loop to be set explicitly, so
		783	it can only be used by a main program knowing about AnyEvent. See
		784	L<AnyEvent::Impl::Async> for the gory details.
		785
		786	AnyEvent::Impl::IOAsync based on IO::Async, cannot be autoprobed.
		787
		788	=item Event loops that are indirectly supported via other backends.
		789
		790	Some event loops can be supported via other modules:
		791
		792	There is no direct support for WxWidgets (L<Wx>) or L<Prima>.
		793
		794	B<WxWidgets> has no support for watching file handles. However, you can
		795	use WxWidgets through the POE adaptor, as POE has a Wx backend that simply
		796	polls 20 times per second, which was considered to be too horrible to even
		797	consider for AnyEvent.
		798
		799	B<Prima> is not supported as nobody seems to be using it, but it has a POE
		800	backend, so it can be supported through POE.
		801
		802	AnyEvent knows about both L<Prima> and L<Wx>, however, and will try to
		803	load L<POE> when detecting them, in the hope that POE will pick them up,
		804	in which case everything will be automatic.
		805
		806	=back
		807
712	=head1 GLOBAL VARIABLES AND FUNCTIONS	808	=head1 GLOBAL VARIABLES AND FUNCTIONS
713		809
		810	These are not normally required to use AnyEvent, but can be useful to
		811	write AnyEvent extension modules.
		812
714	=over 4	813	=over 4
715		814
716	=item $AnyEvent::MODEL	815	=item $AnyEvent::MODEL
717		816
718	Contains C<undef> until the first watcher is being created. Then it	817	Contains C<undef> until the first watcher is being created, before the
		818	backend has been autodetected.
		819
719	contains the event model that is being used, which is the name of the	820	Afterwards it contains the event model that is being used, which is the
720	Perl class implementing the model. This class is usually one of the	821	name of the Perl class implementing the model. This class is usually one
721	C<AnyEvent::Impl:xxx> modules, but can be any other class in the case	822	of the C<AnyEvent::Impl:xxx> modules, but can be any other class in the
722	AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode>).	823	case AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode> it
723		824	will be C<urxvt::anyevent>).
724	The known classes so far are:
725
726	AnyEvent::Impl::EV based on EV (an interface to libev, best choice).
727	AnyEvent::Impl::Event based on Event, second best choice.
728	AnyEvent::Impl::Perl pure-perl implementation, fast and portable.
729	AnyEvent::Impl::Glib based on Glib, third-best choice.
730	AnyEvent::Impl::Tk based on Tk, very bad choice.
731	AnyEvent::Impl::Qt based on Qt, cannot be autoprobed (see its docs).
732	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
733	AnyEvent::Impl::POE based on POE, not generic enough for full support.
734
735	There is no support for WxWidgets, as WxWidgets has no support for
736	watching file handles. However, you can use WxWidgets through the
737	POE Adaptor, as POE has a Wx backend that simply polls 20 times per
738	second, which was considered to be too horrible to even consider for
739	AnyEvent. Likewise, other POE backends can be used by AnyEvent by using
740	it's adaptor.
741
742	AnyEvent knows about L<Prima> and L<Wx> and will try to use L<POE> when
743	autodetecting them.
744		825
745	=item AnyEvent::detect	826	=item AnyEvent::detect
746		827
747	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model	828	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model
748	if necessary. You should only call this function right before you would	829	if necessary. You should only call this function right before you would
749	have created an AnyEvent watcher anyway, that is, as late as possible at	830	have created an AnyEvent watcher anyway, that is, as late as possible at
750	runtime.	831	runtime, and not e.g. while initialising of your module.
		832
		833	If you need to do some initialisation before AnyEvent watchers are
		834	created, use C<post_detect>.
751		835
752	=item $guard = AnyEvent::post_detect { BLOCK }	836	=item $guard = AnyEvent::post_detect { BLOCK }
753		837
754	Arranges for the code block to be executed as soon as the event model is	838	Arranges for the code block to be executed as soon as the event model is
755	autodetected (or immediately if this has already happened).	839	autodetected (or immediately if this has already happened).
		840
		841	The block will be executed I<after> the actual backend has been detected
		842	(C<$AnyEvent::MODEL> is set), but I<before> any watchers have been
		843	created, so it is possible to e.g. patch C<@AnyEvent::ISA> or do
		844	other initialisations - see the sources of L<AnyEvent::Strict> or
		845	L<AnyEvent::AIO> to see how this is used.
		846
		847	The most common usage is to create some global watchers, without forcing
		848	event module detection too early, for example, L<AnyEvent::AIO> creates
		849	and installs the global L<IO::AIO> watcher in a C<post_detect> block to
		850	avoid autodetecting the event module at load time.
756		851
757	If called in scalar or list context, then it creates and returns an object	852	If called in scalar or list context, then it creates and returns an object
758	that automatically removes the callback again when it is destroyed. See	853	that automatically removes the callback again when it is destroyed. See
759	L<Coro::BDB> for a case where this is useful.	854	L<Coro::BDB> for a case where this is useful.
760		855
…		…
763	If there are any code references in this array (you can C<push> to it	858	If there are any code references in this array (you can C<push> to it
764	before or after loading AnyEvent), then they will called directly after	859	before or after loading AnyEvent), then they will called directly after
765	the event loop has been chosen.	860	the event loop has been chosen.
766		861
767	You should check C<$AnyEvent::MODEL> before adding to this array, though:	862	You should check C<$AnyEvent::MODEL> before adding to this array, though:
768	if it contains a true value then the event loop has already been detected,	863	if it is defined then the event loop has already been detected, and the
769	and the array will be ignored.	864	array will be ignored.
770		865
771	Best use C<AnyEvent::post_detect { BLOCK }> instead.	866	Best use C<AnyEvent::post_detect { BLOCK }> when your application allows
		867	it,as it takes care of these details.
		868
		869	This variable is mainly useful for modules that can do something useful
		870	when AnyEvent is used and thus want to know when it is initialised, but do
		871	not need to even load it by default. This array provides the means to hook
		872	into AnyEvent passively, without loading it.
772		873
773	=back	874	=back
774		875
775	=head1 WHAT TO DO IN A MODULE	876	=head1 WHAT TO DO IN A MODULE
776		877
…		…
831		932
832		933
833	=head1 OTHER MODULES	934	=head1 OTHER MODULES
834		935
835	The following is a non-exhaustive list of additional modules that use	936	The following is a non-exhaustive list of additional modules that use
836	AnyEvent and can therefore be mixed easily with other AnyEvent modules	937	AnyEvent as a client and can therefore be mixed easily with other AnyEvent
837	in the same program. Some of the modules come with AnyEvent, some are	938	modules and other event loops in the same program. Some of the modules
838	available via CPAN.	939	come with AnyEvent, most are available via CPAN.
839		940
840	=over 4	941	=over 4
841		942
842	=item L<AnyEvent::Util>	943	=item L<AnyEvent::Util>
843		944
…		…
852		953
853	=item L<AnyEvent::Handle>	954	=item L<AnyEvent::Handle>
854		955
855	Provide read and write buffers, manages watchers for reads and writes,	956	Provide read and write buffers, manages watchers for reads and writes,
856	supports raw and formatted I/O, I/O queued and fully transparent and	957	supports raw and formatted I/O, I/O queued and fully transparent and
857	non-blocking SSL/TLS.	958	non-blocking SSL/TLS (via L<AnyEvent::TLS>.
858		959
859	=item L<AnyEvent::DNS>	960	=item L<AnyEvent::DNS>
860		961
861	Provides rich asynchronous DNS resolver capabilities.	962	Provides rich asynchronous DNS resolver capabilities.
862		963
…		…
890		991
891	=item L<AnyEvent::GPSD>	992	=item L<AnyEvent::GPSD>
892		993
893	A non-blocking interface to gpsd, a daemon delivering GPS information.	994	A non-blocking interface to gpsd, a daemon delivering GPS information.
894		995
		996	=item L<AnyEvent::IRC>
		997
		998	AnyEvent based IRC client module family (replacing the older Net::IRC3).
		999
		1000	=item L<AnyEvent::XMPP>
		1001
		1002	AnyEvent based XMPP (Jabber protocol) module family (replacing the older
		1003	Net::XMPP2>.
		1004
895	=item L<AnyEvent::IGS>	1005	=item L<AnyEvent::IGS>
896		1006
897	A non-blocking interface to the Internet Go Server protocol (used by	1007	A non-blocking interface to the Internet Go Server protocol (used by
898	L<App::IGS>).	1008	L<App::IGS>).
899		1009
900	=item L<AnyEvent::IRC>
901
902	AnyEvent based IRC client module family (replacing the older Net::IRC3).
903
904	=item L<Net::XMPP2>
905
906	AnyEvent based XMPP (Jabber protocol) module family.
907
908	=item L<Net::FCP>	1010	=item L<Net::FCP>
909		1011
910	AnyEvent-based implementation of the Freenet Client Protocol, birthplace	1012	AnyEvent-based implementation of the Freenet Client Protocol, birthplace
911	of AnyEvent.	1013	of AnyEvent.
912		1014
…		…
916		1018
917	=item L<Coro>	1019	=item L<Coro>
918		1020
919	Has special support for AnyEvent via L<Coro::AnyEvent>.	1021	Has special support for AnyEvent via L<Coro::AnyEvent>.
920		1022
921	=item L<IO::Lambda>
922
923	The lambda approach to I/O - don't ask, look there. Can use AnyEvent.
924
925	=back	1023	=back
926		1024
927	=cut	1025	=cut
928		1026
929	package AnyEvent;	1027	package AnyEvent;
930		1028
931	no warnings;	1029	no warnings;
932	use strict qw(vars subs);	1030	use strict qw(vars subs);
933		1031
934	use Carp;	1032	use Carp ();
935		1033
936	our $VERSION = 4.412;	1034	our $VERSION = 4.83;
937	our $MODEL;	1035	our $MODEL;
938		1036
939	our $AUTOLOAD;	1037	our $AUTOLOAD;
940	our @ISA;	1038	our @ISA;
941		1039
…		…
967	[Event:: => AnyEvent::Impl::Event::],	1065	[Event:: => AnyEvent::Impl::Event::],
968	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::],	1066	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::],
969	# everything below here will not be autoprobed	1067	# everything below here will not be autoprobed
970	# as the pureperl backend should work everywhere	1068	# as the pureperl backend should work everywhere
971	# and is usually faster	1069	# and is usually faster
972	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
973	[Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers	1070	[Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers
974	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy	1071	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
		1072	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
975	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program	1073	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program
976	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza	1074	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
977	[Wx:: => AnyEvent::Impl::POE::],	1075	[Wx:: => AnyEvent::Impl::POE::],
978	[Prima:: => AnyEvent::Impl::POE::],	1076	[Prima:: => AnyEvent::Impl::POE::],
		1077	# IO::Async is just too broken - we would need workarounds for its
		1078	# byzantine signal and broken child handling, among others.
		1079	# IO::Async is rather hard to detect, as it doesn't have any
		1080	# obvious default class.
		1081	# [IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program
		1082	# [IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program
		1083	# [IO::Async::Notifier:: => AnyEvent::Impl::IOAsync::], # requires special main program
979	);	1084	);
980		1085
981	our %method = map +($_ => 1),	1086	our %method = map +($_ => 1),
982	qw(io timer time now now_update signal child idle condvar one_event DESTROY);	1087	qw(io timer time now now_update signal child idle condvar one_event DESTROY);
983		1088
…		…
1010		1115
1011	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {	1116	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {
1012	my $model = "AnyEvent::Impl::$1";	1117	my $model = "AnyEvent::Impl::$1";
1013	if (eval "require $model") {	1118	if (eval "require $model") {
1014	$MODEL = $model;	1119	$MODEL = $model;
1015	warn "AnyEvent: loaded model '$model' (forced by \$PERL_ANYEVENT_MODEL), using it.\n" if $verbose > 1;	1120	warn "AnyEvent: loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.\n" if $verbose > 1;
1016	} else {	1121	} else {
1017	warn "AnyEvent: unable to load model '$model' (from \$PERL_ANYEVENT_MODEL):\n$@" if $verbose;	1122	warn "AnyEvent: unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@" if $verbose;
1018	}	1123	}
1019	}	1124	}
1020		1125
1021	# check for already loaded models	1126	# check for already loaded models
1022	unless ($MODEL) {	1127	unless ($MODEL) {
…		…
1064		1169
1065	sub AUTOLOAD {	1170	sub AUTOLOAD {
1066	(my $func = $AUTOLOAD) =~ s/.*://;	1171	(my $func = $AUTOLOAD) =~ s/.*://;
1067		1172
1068	$method{$func}	1173	$method{$func}
1069	or croak "$func: not a valid method for AnyEvent objects";	1174	or Carp::croak "$func: not a valid method for AnyEvent objects";
1070		1175
1071	detect unless $MODEL;	1176	detect unless $MODEL;
1072		1177
1073	my $class = shift;	1178	my $class = shift;
1074	$class->$func (@_);	1179	$class->$func (@_);
1075	}	1180	}
1076		1181
1077	# utility function to dup a filehandle. this is used by many backends	1182	# utility function to dup a filehandle. this is used by many backends
1078	# to support binding more than one watcher per filehandle (they usually	1183	# to support binding more than one watcher per filehandle (they usually
1079	# allow only one watcher per fd, so we dup it to get a different one).	1184	# allow only one watcher per fd, so we dup it to get a different one).
1080	sub _dupfh($$$$) {	1185	sub _dupfh($$;$$) {
1081	my ($poll, $fh, $r, $w) = @_;	1186	my ($poll, $fh, $r, $w) = @_;
1082		1187
1083	# cygwin requires the fh mode to be matching, unix doesn't	1188	# cygwin requires the fh mode to be matching, unix doesn't
1084	my ($rw, $mode) = $poll eq "r" ? ($r, "<")	1189	my ($rw, $mode) = $poll eq "r" ? ($r, "<&") : ($w, ">&");
1085	: $poll eq "w" ? ($w, ">")
1086	: Carp::croak "AnyEvent->io requires poll set to either 'r' or 'w'";
1087		1190
1088	open my $fh2, "$mode&" . fileno $fh	1191	open my $fh2, $mode, $fh
1089	or die "cannot dup() filehandle: $!,";	1192	or die "AnyEvent->io: cannot dup() filehandle in mode '$poll': $!,";
1090		1193
1091	# we assume CLOEXEC is already set by perl in all important cases	1194	# we assume CLOEXEC is already set by perl in all important cases
1092		1195
1093	($fh2, $rw)	1196	($fh2, $rw)
1094	}	1197	}
…		…
1269		1372
1270	use overload	1373	use overload
1271	'&{}' => sub { my $self = shift; sub { $self->send (@_) } },	1374	'&{}' => sub { my $self = shift; sub { $self->send (@_) } },
1272	fallback => 1;	1375	fallback => 1;
1273		1376
		1377	our $WAITING;
		1378
1274	sub _send {	1379	sub _send {
1275	# nop	1380	# nop
1276	}	1381	}
1277		1382
1278	sub send {	1383	sub send {
…		…
1290	sub ready {	1395	sub ready {
1291	$_[0]{_ae_sent}	1396	$_[0]{_ae_sent}
1292	}	1397	}
1293		1398
1294	sub _wait {	1399	sub _wait {
		1400	$WAITING
		1401	and !$_[0]{_ae_sent}
		1402	and Carp::croak "AnyEvent::CondVar: recursive blocking wait detected";
		1403
		1404	local $WAITING = 1;
1295	AnyEvent->one_event while !$_[0]{_ae_sent};	1405	AnyEvent->one_event while !$_[0]{_ae_sent};
1296	}	1406	}
1297		1407
1298	sub recv {	1408	sub recv {
1299	$_[0]->_wait;	1409	$_[0]->_wait;
…		…
1426		1536
1427	=item C<PERL_ANYEVENT_MAX_FORKS>	1537	=item C<PERL_ANYEVENT_MAX_FORKS>
1428		1538
1429	The maximum number of child processes that C<AnyEvent::Util::fork_call>	1539	The maximum number of child processes that C<AnyEvent::Util::fork_call>
1430	will create in parallel.	1540	will create in parallel.
		1541
		1542	=item C<PERL_ANYEVENT_MAX_OUTSTANDING_DNS>
		1543
		1544	The default value for the C<max_outstanding> parameter for the default DNS
		1545	resolver - this is the maximum number of parallel DNS requests that are
		1546	sent to the DNS server.
		1547
		1548	=item C<PERL_ANYEVENT_RESOLV_CONF>
		1549
		1550	The file to use instead of F</etc/resolv.conf> (or OS-specific
		1551	configuration) in the default resolver. When set to the empty string, no
		1552	default config will be used.
		1553
		1554	=item C<PERL_ANYEVENT_CA_FILE>, C<PERL_ANYEVENT_CA_PATH>.
		1555
		1556	When neither C<ca_file> nor C<ca_path> was specified during
		1557	L<AnyEvent::TLS> context creation, and either of these environment
		1558	variables exist, they will be used to specify CA certificate locations
		1559	instead of a system-dependent default.
1431		1560
1432	=back	1561	=back
1433		1562
1434	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE	1563	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE
1435		1564
…		…
1680	EV/Any 100000 224 2.88 0.34 0.27 EV + AnyEvent watchers	1809	EV/Any 100000 224 2.88 0.34 0.27 EV + AnyEvent watchers
1681	CoroEV/Any 100000 224 2.85 0.35 0.28 coroutines + Coro::Signal	1810	CoroEV/Any 100000 224 2.85 0.35 0.28 coroutines + Coro::Signal
1682	Perl/Any 100000 452 4.13 0.73 0.95 pure perl implementation	1811	Perl/Any 100000 452 4.13 0.73 0.95 pure perl implementation
1683	Event/Event 16000 517 32.20 31.80 0.81 Event native interface	1812	Event/Event 16000 517 32.20 31.80 0.81 Event native interface
1684	Event/Any 16000 590 35.85 31.55 1.06 Event + AnyEvent watchers	1813	Event/Any 16000 590 35.85 31.55 1.06 Event + AnyEvent watchers
		1814	IOAsync/Any 16000 989 38.10 32.77 11.13 via IO::Async::Loop::IO_Poll
		1815	IOAsync/Any 16000 990 37.59 29.50 10.61 via IO::Async::Loop::Epoll
1685	Glib/Any 16000 1357 102.33 12.31 51.00 quadratic behaviour	1816	Glib/Any 16000 1357 102.33 12.31 51.00 quadratic behaviour
1686	Tk/Any 2000 1860 27.20 66.31 14.00 SEGV with >> 2000 watchers	1817	Tk/Any 2000 1860 27.20 66.31 14.00 SEGV with >> 2000 watchers
1687	POE/Event 2000 6328 109.99 751.67 14.02 via POE::Loop::Event	1818	POE/Event 2000 6328 109.99 751.67 14.02 via POE::Loop::Event
1688	POE/Select 2000 6027 94.54 809.13 579.80 via POE::Loop::Select	1819	POE/Select 2000 6027 94.54 809.13 579.80 via POE::Loop::Select
1689		1820
…		…
1718	performance becomes really bad with lots of file descriptors (and few of	1849	performance becomes really bad with lots of file descriptors (and few of
1719	them active), of course, but this was not subject of this benchmark.	1850	them active), of course, but this was not subject of this benchmark.
1720		1851
1721	The C<Event> module has a relatively high setup and callback invocation	1852	The C<Event> module has a relatively high setup and callback invocation
1722	cost, but overall scores in on the third place.	1853	cost, but overall scores in on the third place.
		1854
		1855	C<IO::Async> performs admirably well, about on par with C<Event>, even
		1856	when using its pure perl backend.
1723		1857
1724	C<Glib>'s memory usage is quite a bit higher, but it features a	1858	C<Glib>'s memory usage is quite a bit higher, but it features a
1725	faster callback invocation and overall ends up in the same class as	1859	faster callback invocation and overall ends up in the same class as
1726	C<Event>. However, Glib scales extremely badly, doubling the number of	1860	C<Event>. However, Glib scales extremely badly, doubling the number of
1727	watchers increases the processing time by more than a factor of four,	1861	watchers increases the processing time by more than a factor of four,
…		…
1805	it to another server. This includes deleting the old timeout and creating	1939	it to another server. This includes deleting the old timeout and creating
1806	a new one that moves the timeout into the future.	1940	a new one that moves the timeout into the future.
1807		1941
1808	=head3 Results	1942	=head3 Results
1809		1943
1810	name sockets create request	1944	name sockets create request
1811	EV 20000 69.01 11.16	1945	EV 20000 69.01 11.16
1812	Perl 20000 73.32 35.87	1946	Perl 20000 73.32 35.87
		1947	IOAsync 20000 157.00 98.14 epoll
		1948	IOAsync 20000 159.31 616.06 poll
1813	Event 20000 212.62 257.32	1949	Event 20000 212.62 257.32
1814	Glib 20000 651.16 1896.30	1950	Glib 20000 651.16 1896.30
1815	POE 20000 349.67 12317.24 uses POE::Loop::Event	1951	POE 20000 349.67 12317.24 uses POE::Loop::Event
1816		1952
1817	=head3 Discussion	1953	=head3 Discussion
1818		1954
1819	This benchmark I<does> measure scalability and overall performance of the	1955	This benchmark I<does> measure scalability and overall performance of the
1820	particular event loop.	1956	particular event loop.
…		…
1822	EV is again fastest. Since it is using epoll on my system, the setup time	1958	EV is again fastest. Since it is using epoll on my system, the setup time
1823	is relatively high, though.	1959	is relatively high, though.
1824		1960
1825	Perl surprisingly comes second. It is much faster than the C-based event	1961	Perl surprisingly comes second. It is much faster than the C-based event
1826	loops Event and Glib.	1962	loops Event and Glib.
		1963
		1964	IO::Async performs very well when using its epoll backend, and still quite
		1965	good compared to Glib when using its pure perl backend.
1827		1966
1828	Event suffers from high setup time as well (look at its code and you will	1967	Event suffers from high setup time as well (look at its code and you will
1829	understand why). Callback invocation also has a high overhead compared to	1968	understand why). Callback invocation also has a high overhead compared to
1830	the C<< $_->() for .. >>-style loop that the Perl event loop uses. Event	1969	the C<< $_->() for .. >>-style loop that the Perl event loop uses. Event
1831	uses select or poll in basically all documented configurations.	1970	uses select or poll in basically all documented configurations.
…		…
1964		2103
1965	A handler for C<SIGCHLD> is installed by AnyEvent's child watcher	2104	A handler for C<SIGCHLD> is installed by AnyEvent's child watcher
1966	emulation for event loops that do not support them natively. Also, some	2105	emulation for event loops that do not support them natively. Also, some
1967	event loops install a similar handler.	2106	event loops install a similar handler.
1968		2107
		2108	Additionally, when AnyEvent is loaded and SIGCHLD is set to IGNORE, then
		2109	AnyEvent will reset it to default, to avoid losing child exit statuses.
		2110
1969	=item SIGPIPE	2111	=item SIGPIPE
1970		2112
1971	A no-op handler is installed for C<SIGPIPE> when C<$SIG{PIPE}> is C<undef>	2113	A no-op handler is installed for C<SIGPIPE> when C<$SIG{PIPE}> is C<undef>
1972	when AnyEvent gets loaded.	2114	when AnyEvent gets loaded.
1973		2115
…		…
1984		2126
1985	=back	2127	=back
1986		2128
1987	=cut	2129	=cut
1988		2130
		2131	undef $SIG{CHLD}
		2132	if $SIG{CHLD} eq 'IGNORE';
		2133
1989	$SIG{PIPE} = sub { }	2134	$SIG{PIPE} = sub { }
1990	unless defined $SIG{PIPE};	2135	unless defined $SIG{PIPE};
1991
1992		2136
1993	=head1 FORK	2137	=head1 FORK
1994		2138
1995	Most event libraries are not fork-safe. The ones who are usually are	2139	Most event libraries are not fork-safe. The ones who are usually are
1996	because they rely on inefficient but fork-safe C<select> or C<poll>	2140	because they rely on inefficient but fork-safe C<select> or C<poll>
…		…
2043	L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.	2187	L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.
2044		2188
2045	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,	2189	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,
2046	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,	2190	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,
2047	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,	2191	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,
2048	L<AnyEvent::Impl::POE>.	2192	L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>.
2049		2193
2050	Non-blocking file handles, sockets, TCP clients and	2194	Non-blocking file handles, sockets, TCP clients and
2051	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>.	2195	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.
2052		2196
2053	Asynchronous DNS: L<AnyEvent::DNS>.	2197	Asynchronous DNS: L<AnyEvent::DNS>.
2054		2198
2055	Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>,	2199	Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>,
		2200	L<Coro::Event>,
2056		2201
2057	Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>, L<AnyEvent::DNS>.	2202	Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::XMPP>,
		2203	L<AnyEvent::HTTP>.
2058		2204
2059		2205
2060	=head1 AUTHOR	2206	=head1 AUTHOR
2061		2207
2062	Marc Lehmann <schmorp@schmorp.de>	2208	Marc Lehmann <schmorp@schmorp.de>

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Comparing AnyEvent/lib/AnyEvent.pm (file contents): Revision 1.218 by root, Wed Jun 24 10:03:42 2009 UTC vs. Revision 1.241 by root, Fri Jul 17 18:08:35 2009 UTC

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Comparing AnyEvent/lib/AnyEvent.pm (file contents):
Revision 1.218 by root, Wed Jun 24 10:03:42 2009 UTC vs.
Revision 1.241 by root, Fri Jul 17 18:08:35 2009 UTC