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

Comparing AnyEvent/lib/AnyEvent.pm (file contents):
Revision 1.217 by root, Tue Jun 23 23:37:32 2009 UTC vs.
Revision 1.245 by root, Sat Jul 18 05:19:09 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.
…		…
361	invocation, and callback invocation will be synchronous. Synchronous means	361	invocation, and callback invocation will be synchronous. Synchronous means
362	that it might take a while until the signal gets handled by the process,	362	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.	363	but it is guaranteed not to interrupt any other callbacks.
364		364
365	The main advantage of using these watchers is that you can share a signal	365	The main advantage of using these watchers is that you can share a signal
366	between multiple watchers.	366	between multiple watchers, and AnyEvent will ensure that signals will not
		367	interrupt your program at bad times.
367		368
368	This watcher might use C<%SIG>, so programs overwriting those signals	369	This watcher might use C<%SIG> (depending on the event loop used),
369	directly will likely not work correctly.	370	so programs overwriting those signals directly will likely not work
		371	correctly.
		372
		373	Also note that many event loops (e.g. Glib, Tk, Qt, IO::Async) do not
		374	support attaching callbacks to signals, which is a pity, as you cannot do
		375	race-free signal handling in perl. AnyEvent will try to do it's best, but
		376	in some cases, signals will be delayed. The maximum time a signal might
		377	be delayed is specified in C<$AnyEvent::MAX_SIGNAL_LATENCY> (default: 10
		378	seconds). This variable can be changed only before the first signal
		379	watcher is created, and should be left alone otherwise. Higher values
		380	will cause fewer spurious wake-ups, which is better for power and CPU
		381	saving. All these problems can be avoided by installing the optional
		382	L<Async::Interrupt> module.
370		383
371	Example: exit on SIGINT	384	Example: exit on SIGINT
372		385
373	my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });	386	my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });
374		387
…		…
392		405
393	There is a slight catch to child watchers, however: you usually start them	406	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	407	I<after> the child process was created, and this means the process could
395	have exited already (and no SIGCHLD will be sent anymore).	408	have exited already (and no SIGCHLD will be sent anymore).
396		409
397	Not all event models handle this correctly (POE doesn't), but even for	410	Not all event models handle this correctly (neither POE nor IO::Async do,
		411	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	412	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).	413	the process exits (i.e. before you fork in the first place). AnyEvent's
		414	pure perl event loop handles all cases correctly regardless of when you
		415	start the watcher.
400		416
401	This means you cannot create a child watcher as the very first thing in an	417	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	418	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>).	419	watcher before you C<fork> the child (alternatively, you can call
		420	C<AnyEvent::detect>).
		421
		422	As most event loops do not support waiting for child events, they will be
		423	emulated by AnyEvent in most cases, in which the latency and race problems
		424	mentioned in the description of signal watchers apply.
404		425
405	Example: fork a process and wait for it	426	Example: fork a process and wait for it
406		427
407	my $done = AnyEvent->condvar;	428	my $done = AnyEvent->condvar;
408		429
…		…
459		480
460	If you are familiar with some event loops you will know that all of them	481	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	482	require you to run some blocking "loop", "run" or similar function that
462	will actively watch for new events and call your callbacks.	483	will actively watch for new events and call your callbacks.
463		484
464	AnyEvent is different, it expects somebody else to run the event loop and	485	AnyEvent is slightly different: it expects somebody else to run the event
465	will only block when necessary (usually when told by the user).	486	loop and will only block when necessary (usually when told by the user).
466		487
467	The instrument to do that is called a "condition variable", so called	488	The instrument to do that is called a "condition variable", so called
468	because they represent a condition that must become true.	489	because they represent a condition that must become true.
469		490
		491	Now is probably a good time to look at the examples further below.
		492
470	Condition variables can be created by calling the C<< AnyEvent->condvar	493	Condition variables can be created by calling the C<< AnyEvent->condvar
471	>> method, usually without arguments. The only argument pair allowed is	494	>> 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	495	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	496	becomes true, with the condition variable as the first argument (but not
475	the results).	497	the results).
476		498
477	After creation, the condition variable is "false" until it becomes "true"	499	After creation, the condition variable is "false" until it becomes "true"
…		…
526	after => 1,	548	after => 1,
527	cb => sub { $result_ready->send },	549	cb => sub { $result_ready->send },
528	);	550	);
529		551
530	# this "blocks" (while handling events) till the callback	552	# this "blocks" (while handling events) till the callback
531	# calls send	553	# calls -<send
532	$result_ready->recv;	554	$result_ready->recv;
533		555
534	Example: wait for a timer, but take advantage of the fact that	556	Example: wait for a timer, but take advantage of the fact that condition
535	condition variables are also code references.	557	variables are also callable directly.
536		558
537	my $done = AnyEvent->condvar;	559	my $done = AnyEvent->condvar;
538	my $delay = AnyEvent->timer (after => 5, cb => $done);	560	my $delay = AnyEvent->timer (after => 5, cb => $done);
539	$done->recv;	561	$done->recv;
540		562
…		…
546		568
547	...	569	...
548		570
549	my @info = $couchdb->info->recv;	571	my @info = $couchdb->info->recv;
550		572
551	And this is how you would just ste a callback to be called whenever the	573	And this is how you would just set a callback to be called whenever the
552	results are available:	574	results are available:
553		575
554	$couchdb->info->cb (sub {	576	$couchdb->info->cb (sub {
555	my @info = $_[0]->recv;	577	my @info = $_[0]->recv;
556	});	578	});
…		…
574	immediately from within send.	596	immediately from within send.
575		597
576	Any arguments passed to the C<send> call will be returned by all	598	Any arguments passed to the C<send> call will be returned by all
577	future C<< ->recv >> calls.	599	future C<< ->recv >> calls.
578		600
579	Condition variables are overloaded so one can call them directly	601	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	602	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	603	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		604
588	=item $cv->croak ($error)	605	=item $cv->croak ($error)
589		606
590	Similar to send, but causes all call's to C<< ->recv >> to invoke	607	Similar to send, but causes all call's to C<< ->recv >> to invoke
591	C<Carp::croak> with the given error message/object/scalar.	608	C<Carp::croak> with the given error message/object/scalar.
592		609
593	This can be used to signal any errors to the condition variable	610	This can be used to signal any errors to the condition variable
594	user/consumer.	611	user/consumer. Doing it this way instead of calling C<croak> directly
		612	delays the error detetcion, but has the overwhelmign advantage that it
		613	diagnoses the error at the place where the result is expected, and not
		614	deep in some event clalback without connection to the actual code causing
		615	the problem.
595		616
596	=item $cv->begin ([group callback])	617	=item $cv->begin ([group callback])
597		618
598	=item $cv->end	619	=item $cv->end
599
600	These two methods are EXPERIMENTAL and MIGHT CHANGE.
601		620
602	These two methods can be used to combine many transactions/events into	621	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	622	one. For example, a function that pings many hosts in parallel might want
604	to use a condition variable for the whole process.	623	to use a condition variable for the whole process.
605		624
…		…
607	C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end	626	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	627	>>, 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	628	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.	629	callback was set, C<send> will be called without any arguments.
611		630
612	Let's clarify this with the ping example:	631	You can think of C<< $cv->send >> giving you an OR condition (one call
		632	sends), while C<< $cv->begin >> and C<< $cv->end >> giving you an AND
		633	condition (all C<begin> calls must be C<end>'ed before the condvar sends).
		634
		635	Let's start with a simple example: you have two I/O watchers (for example,
		636	STDOUT and STDERR for a program), and you want to wait for both streams to
		637	close before activating a condvar:
		638
		639	my $cv = AnyEvent->condvar;
		640
		641	$cv->begin; # first watcher
		642	my $w1 = AnyEvent->io (fh => $fh1, cb => sub {
		643	defined sysread $fh1, my $buf, 4096
		644	or $cv->end;
		645	});
		646
		647	$cv->begin; # second watcher
		648	my $w2 = AnyEvent->io (fh => $fh2, cb => sub {
		649	defined sysread $fh2, my $buf, 4096
		650	or $cv->end;
		651	});
		652
		653	$cv->recv;
		654
		655	This works because for every event source (EOF on file handle), there is
		656	one call to C<begin>, so the condvar waits for all calls to C<end> before
		657	sending.
		658
		659	The ping example mentioned above is slightly more complicated, as the
		660	there are results to be passwd back, and the number of tasks that are
		661	begung can potentially be zero:
613		662
614	my $cv = AnyEvent->condvar;	663	my $cv = AnyEvent->condvar;
615		664
616	my %result;	665	my %result;
617	$cv->begin (sub { $cv->send (\%result) });	666	$cv->begin (sub { $cv->send (\%result) });
…		…
637	loop, which serves two important purposes: first, it sets the callback	686	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	687	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	688	C<send> is called even when C<no> hosts are being pinged (the loop
640	doesn't execute once).	689	doesn't execute once).
641		690
642	This is the general pattern when you "fan out" into multiple subrequests:	691	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>	692	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	693	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>.	694	subrequest you start, call C<begin> and for each subrequest you finish,
		695	call C<end>.
646		696
647	=back	697	=back
648		698
649	=head3 METHODS FOR CONSUMERS	699	=head3 METHODS FOR CONSUMERS
650		700
…		…
666	function will call C<croak>.	716	function will call C<croak>.
667		717
668	In list context, all parameters passed to C<send> will be returned,	718	In list context, all parameters passed to C<send> will be returned,
669	in scalar context only the first one will be returned.	719	in scalar context only the first one will be returned.
670		720
		721	Note that doing a blocking wait in a callback is not supported by any
		722	event loop, that is, recursive invocation of a blocking C<< ->recv
		723	>> is not allowed, and the C<recv> call will C<croak> if such a
		724	condition is detected. This condition can be slightly loosened by using
		725	L<Coro::AnyEvent>, which allows you to do a blocking C<< ->recv >> from
		726	any thread that doesn't run the event loop itself.
		727
671	Not all event models support a blocking wait - some die in that case	728	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	729	(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	730	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	731	caller decide whether the call will block or not (for example, by coupling
675	condition variables with some kind of request results and supporting	732	condition variables with some kind of request results and supporting
676	callbacks so the caller knows that getting the result will not block,	733	callbacks so the caller knows that getting the result will not block,
677	while still supporting blocking waits if the caller so desires).	734	while still supporting blocking waits if the caller so desires).
678		735
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	736	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	737	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	738	time). This will work even when the event loop does not support blocking
693	waits otherwise.	739	waits otherwise.
694		740
…		…
707	variable itself. Calling C<recv> inside the callback or at any later time	753	variable itself. Calling C<recv> inside the callback or at any later time
708	is guaranteed not to block.	754	is guaranteed not to block.
709		755
710	=back	756	=back
711		757
		758	=head1 SUPPORTED EVENT LOOPS/BACKENDS
		759
		760	The available backend classes are (every class has its own manpage):
		761
		762	=over 4
		763
		764	=item Backends that are autoprobed when no other event loop can be found.
		765
		766	EV is the preferred backend when no other event loop seems to be in
		767	use. If EV is not installed, then AnyEvent will try Event, and, failing
		768	that, will fall back to its own pure-perl implementation, which is
		769	available everywhere as it comes with AnyEvent itself.
		770
		771	AnyEvent::Impl::EV based on EV (interface to libev, best choice).
		772	AnyEvent::Impl::Event based on Event, very stable, few glitches.
		773	AnyEvent::Impl::Perl pure-perl implementation, fast and portable.
		774
		775	=item Backends that are transparently being picked up when they are used.
		776
		777	These will be used when they are currently loaded when the first watcher
		778	is created, in which case it is assumed that the application is using
		779	them. This means that AnyEvent will automatically pick the right backend
		780	when the main program loads an event module before anything starts to
		781	create watchers. Nothing special needs to be done by the main program.
		782
		783	AnyEvent::Impl::Glib based on Glib, slow but very stable.
		784	AnyEvent::Impl::Tk based on Tk, very broken.
		785	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
		786	AnyEvent::Impl::POE based on POE, very slow, some limitations.
		787
		788	=item Backends with special needs.
		789
		790	Qt requires the Qt::Application to be instantiated first, but will
		791	otherwise be picked up automatically. As long as the main program
		792	instantiates the application before any AnyEvent watchers are created,
		793	everything should just work.
		794
		795	AnyEvent::Impl::Qt based on Qt.
		796
		797	Support for IO::Async can only be partial, as it is too broken and
		798	architecturally limited to even support the AnyEvent API. It also
		799	is the only event loop that needs the loop to be set explicitly, so
		800	it can only be used by a main program knowing about AnyEvent. See
		801	L<AnyEvent::Impl::Async> for the gory details.
		802
		803	AnyEvent::Impl::IOAsync based on IO::Async, cannot be autoprobed.
		804
		805	=item Event loops that are indirectly supported via other backends.
		806
		807	Some event loops can be supported via other modules:
		808
		809	There is no direct support for WxWidgets (L<Wx>) or L<Prima>.
		810
		811	B<WxWidgets> has no support for watching file handles. However, you can
		812	use WxWidgets through the POE adaptor, as POE has a Wx backend that simply
		813	polls 20 times per second, which was considered to be too horrible to even
		814	consider for AnyEvent.
		815
		816	B<Prima> is not supported as nobody seems to be using it, but it has a POE
		817	backend, so it can be supported through POE.
		818
		819	AnyEvent knows about both L<Prima> and L<Wx>, however, and will try to
		820	load L<POE> when detecting them, in the hope that POE will pick them up,
		821	in which case everything will be automatic.
		822
		823	=back
		824
712	=head1 GLOBAL VARIABLES AND FUNCTIONS	825	=head1 GLOBAL VARIABLES AND FUNCTIONS
713		826
		827	These are not normally required to use AnyEvent, but can be useful to
		828	write AnyEvent extension modules.
		829
714	=over 4	830	=over 4
715		831
716	=item $AnyEvent::MODEL	832	=item $AnyEvent::MODEL
717		833
718	Contains C<undef> until the first watcher is being created. Then it	834	Contains C<undef> until the first watcher is being created, before the
		835	backend has been autodetected.
		836
719	contains the event model that is being used, which is the name of the	837	Afterwards it contains the event model that is being used, which is the
720	Perl class implementing the model. This class is usually one of the	838	name of the Perl class implementing the model. This class is usually one
721	C<AnyEvent::Impl:xxx> modules, but can be any other class in the case	839	of the C<AnyEvent::Impl:xxx> modules, but can be any other class in the
722	AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode>).	840	case AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode> it
723		841	will be C<urxvt::anyevent>).
724	The known classes so far are:
725
726	AnyEvent::Impl::EV based on EV (an interface to libev, best choice).
727	AnyEvent::Impl::Event based on Event, second best choice.
728	AnyEvent::Impl::Perl pure-perl implementation, fast and portable.
729	AnyEvent::Impl::Glib based on Glib, third-best choice.
730	AnyEvent::Impl::Tk based on Tk, very bad choice.
731	AnyEvent::Impl::Qt based on Qt, cannot be autoprobed (see its docs).
732	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
733	AnyEvent::Impl::POE based on POE, not generic enough for full support.
734
735	There is no support for WxWidgets, as WxWidgets has no support for
736	watching file handles. However, you can use WxWidgets through the
737	POE Adaptor, as POE has a Wx backend that simply polls 20 times per
738	second, which was considered to be too horrible to even consider for
739	AnyEvent. Likewise, other POE backends can be used by AnyEvent by using
740	it's adaptor.
741
742	AnyEvent knows about L<Prima> and L<Wx> and will try to use L<POE> when
743	autodetecting them.
744		842
745	=item AnyEvent::detect	843	=item AnyEvent::detect
746		844
747	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model	845	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model
748	if necessary. You should only call this function right before you would	846	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	847	have created an AnyEvent watcher anyway, that is, as late as possible at
750	runtime.	848	runtime, and not e.g. while initialising of your module.
		849
		850	If you need to do some initialisation before AnyEvent watchers are
		851	created, use C<post_detect>.
751		852
752	=item $guard = AnyEvent::post_detect { BLOCK }	853	=item $guard = AnyEvent::post_detect { BLOCK }
753		854
754	Arranges for the code block to be executed as soon as the event model is	855	Arranges for the code block to be executed as soon as the event model is
755	autodetected (or immediately if this has already happened).	856	autodetected (or immediately if this has already happened).
		857
		858	The block will be executed I<after> the actual backend has been detected
		859	(C<$AnyEvent::MODEL> is set), but I<before> any watchers have been
		860	created, so it is possible to e.g. patch C<@AnyEvent::ISA> or do
		861	other initialisations - see the sources of L<AnyEvent::Strict> or
		862	L<AnyEvent::AIO> to see how this is used.
		863
		864	The most common usage is to create some global watchers, without forcing
		865	event module detection too early, for example, L<AnyEvent::AIO> creates
		866	and installs the global L<IO::AIO> watcher in a C<post_detect> block to
		867	avoid autodetecting the event module at load time.
756		868
757	If called in scalar or list context, then it creates and returns an object	869	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	870	that automatically removes the callback again when it is destroyed. See
759	L<Coro::BDB> for a case where this is useful.	871	L<Coro::BDB> for a case where this is useful.
760		872
…		…
763	If there are any code references in this array (you can C<push> to it	875	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	876	before or after loading AnyEvent), then they will called directly after
765	the event loop has been chosen.	877	the event loop has been chosen.
766		878
767	You should check C<$AnyEvent::MODEL> before adding to this array, though:	879	You should check C<$AnyEvent::MODEL> before adding to this array, though:
768	if it contains a true value then the event loop has already been detected,	880	if it is defined then the event loop has already been detected, and the
769	and the array will be ignored.	881	array will be ignored.
770		882
771	Best use C<AnyEvent::post_detect { BLOCK }> instead.	883	Best use C<AnyEvent::post_detect { BLOCK }> when your application allows
		884	it,as it takes care of these details.
		885
		886	This variable is mainly useful for modules that can do something useful
		887	when AnyEvent is used and thus want to know when it is initialised, but do
		888	not need to even load it by default. This array provides the means to hook
		889	into AnyEvent passively, without loading it.
772		890
773	=back	891	=back
774		892
775	=head1 WHAT TO DO IN A MODULE	893	=head1 WHAT TO DO IN A MODULE
776		894
…		…
831		949
832		950
833	=head1 OTHER MODULES	951	=head1 OTHER MODULES
834		952
835	The following is a non-exhaustive list of additional modules that use	953	The following is a non-exhaustive list of additional modules that use
836	AnyEvent and can therefore be mixed easily with other AnyEvent modules	954	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	955	modules and other event loops in the same program. Some of the modules
838	available via CPAN.	956	come with AnyEvent, most are available via CPAN.
839		957
840	=over 4	958	=over 4
841		959
842	=item L<AnyEvent::Util>	960	=item L<AnyEvent::Util>
843		961
…		…
852		970
853	=item L<AnyEvent::Handle>	971	=item L<AnyEvent::Handle>
854		972
855	Provide read and write buffers, manages watchers for reads and writes,	973	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	974	supports raw and formatted I/O, I/O queued and fully transparent and
857	non-blocking SSL/TLS.	975	non-blocking SSL/TLS (via L<AnyEvent::TLS>.
858		976
859	=item L<AnyEvent::DNS>	977	=item L<AnyEvent::DNS>
860		978
861	Provides rich asynchronous DNS resolver capabilities.	979	Provides rich asynchronous DNS resolver capabilities.
862		980
…		…
890		1008
891	=item L<AnyEvent::GPSD>	1009	=item L<AnyEvent::GPSD>
892		1010
893	A non-blocking interface to gpsd, a daemon delivering GPS information.	1011	A non-blocking interface to gpsd, a daemon delivering GPS information.
894		1012
		1013	=item L<AnyEvent::IRC>
		1014
		1015	AnyEvent based IRC client module family (replacing the older Net::IRC3).
		1016
		1017	=item L<AnyEvent::XMPP>
		1018
		1019	AnyEvent based XMPP (Jabber protocol) module family (replacing the older
		1020	Net::XMPP2>.
		1021
895	=item L<AnyEvent::IGS>	1022	=item L<AnyEvent::IGS>
896		1023
897	A non-blocking interface to the Internet Go Server protocol (used by	1024	A non-blocking interface to the Internet Go Server protocol (used by
898	L<App::IGS>).	1025	L<App::IGS>).
899		1026
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>	1027	=item L<Net::FCP>
909		1028
910	AnyEvent-based implementation of the Freenet Client Protocol, birthplace	1029	AnyEvent-based implementation of the Freenet Client Protocol, birthplace
911	of AnyEvent.	1030	of AnyEvent.
912		1031
…		…
916		1035
917	=item L<Coro>	1036	=item L<Coro>
918		1037
919	Has special support for AnyEvent via L<Coro::AnyEvent>.	1038	Has special support for AnyEvent via L<Coro::AnyEvent>.
920		1039
921	=item L<IO::Lambda>
922
923	The lambda approach to I/O - don't ask, look there. Can use AnyEvent.
924
925	=back	1040	=back
926		1041
927	=cut	1042	=cut
928		1043
929	package AnyEvent;	1044	package AnyEvent;
930		1045
		1046	# basically a tuned-down version of common::sense
		1047	sub common_sense {
931	no warnings;	1048	# no warnings
		1049	${^WARNING_BITS} ^= ${^WARNING_BITS};
932	use strict qw(vars subs);	1050	# use strict vars subs
		1051	$^H \|= 0x00000600;
		1052	}
933		1053
		1054	BEGIN { AnyEvent::common_sense }
		1055
934	use Carp;	1056	use Carp ();
935		1057
936	our $VERSION = 4.412;	1058	our $VERSION = 4.85;
937	our $MODEL;	1059	our $MODEL;
938		1060
939	our $AUTOLOAD;	1061	our $AUTOLOAD;
940	our @ISA;	1062	our @ISA;
941		1063
942	our @REGISTRY;	1064	our @REGISTRY;
943		1065
944	our $WIN32;	1066	our $WIN32;
		1067
		1068	our $VERBOSE;
945		1069
946	BEGIN {	1070	BEGIN {
947	eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }";	1071	eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }";
948	eval "sub TAINT(){ " . (${^TAINT}*1) . " }";	1072	eval "sub TAINT(){ " . (${^TAINT}*1) . " }";
949		1073
950	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}	1074	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}
951	if ${^TAINT};	1075	if ${^TAINT};
952	}
953		1076
954	our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1;	1077	$VERBOSE = $ENV{PERL_ANYEVENT_VERBOSE}*1;
		1078
		1079	}
		1080
		1081	our $MAX_SIGNAL_LATENCY = 10;
955		1082
956	our %PROTOCOL; # (ipv4\|ipv6) => (1\|2), higher numbers are preferred	1083	our %PROTOCOL; # (ipv4\|ipv6) => (1\|2), higher numbers are preferred
957		1084
958	{	1085	{
959	my $idx;	1086	my $idx;
…		…
967	[Event:: => AnyEvent::Impl::Event::],	1094	[Event:: => AnyEvent::Impl::Event::],
968	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::],	1095	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::],
969	# everything below here will not be autoprobed	1096	# everything below here will not be autoprobed
970	# as the pureperl backend should work everywhere	1097	# as the pureperl backend should work everywhere
971	# and is usually faster	1098	# and is usually faster
972	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
973	[Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers	1099	[Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers
974	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy	1100	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
		1101	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
975	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program	1102	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program
976	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza	1103	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
977	[Wx:: => AnyEvent::Impl::POE::],	1104	[Wx:: => AnyEvent::Impl::POE::],
978	[Prima:: => AnyEvent::Impl::POE::],	1105	[Prima:: => AnyEvent::Impl::POE::],
		1106	# IO::Async is just too broken - we would need workarounds for its
		1107	# byzantine signal and broken child handling, among others.
		1108	# IO::Async is rather hard to detect, as it doesn't have any
		1109	# obvious default class.
		1110	# [IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program
		1111	# [IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program
		1112	# [IO::Async::Notifier:: => AnyEvent::Impl::IOAsync::], # requires special main program
979	);	1113	);
980		1114
981	our %method = map +($_ => 1),	1115	our %method = map +($_ => 1),
982	qw(io timer time now now_update signal child idle condvar one_event DESTROY);	1116	qw(io timer time now now_update signal child idle condvar one_event DESTROY);
983		1117
…		…
1003	@post_detect = grep $_ != ${$_[0]}, @post_detect;	1137	@post_detect = grep $_ != ${$_[0]}, @post_detect;
1004	}	1138	}
1005		1139
1006	sub detect() {	1140	sub detect() {
1007	unless ($MODEL) {	1141	unless ($MODEL) {
1008	no strict 'refs';
1009	local $SIG{__DIE__};	1142	local $SIG{__DIE__};
1010		1143
1011	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {	1144	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {
1012	my $model = "AnyEvent::Impl::$1";	1145	my $model = "AnyEvent::Impl::$1";
1013	if (eval "require $model") {	1146	if (eval "require $model") {
1014	$MODEL = $model;	1147	$MODEL = $model;
1015	warn "AnyEvent: loaded model '$model' (forced by \$PERL_ANYEVENT_MODEL), using it.\n" if $verbose > 1;	1148	warn "AnyEvent: loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.\n" if $VERBOSE >= 2;
1016	} else {	1149	} else {
1017	warn "AnyEvent: unable to load model '$model' (from \$PERL_ANYEVENT_MODEL):\n$@" if $verbose;	1150	warn "AnyEvent: unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@" if $VERBOSE;
1018	}	1151	}
1019	}	1152	}
1020		1153
1021	# check for already loaded models	1154	# check for already loaded models
1022	unless ($MODEL) {	1155	unless ($MODEL) {
1023	for (@REGISTRY, @models) {	1156	for (@REGISTRY, @models) {
1024	my ($package, $model) = @$_;	1157	my ($package, $model) = @$_;
1025	if (${"$package\::VERSION"} > 0) {	1158	if (${"$package\::VERSION"} > 0) {
1026	if (eval "require $model") {	1159	if (eval "require $model") {
1027	$MODEL = $model;	1160	$MODEL = $model;
1028	warn "AnyEvent: autodetected model '$model', using it.\n" if $verbose > 1;	1161	warn "AnyEvent: autodetected model '$model', using it.\n" if $VERBOSE >= 2;
1029	last;	1162	last;
1030	}	1163	}
1031	}	1164	}
1032	}	1165	}
1033		1166
…		…
1038	my ($package, $model) = @$_;	1171	my ($package, $model) = @$_;
1039	if (eval "require $package"	1172	if (eval "require $package"
1040	and ${"$package\::VERSION"} > 0	1173	and ${"$package\::VERSION"} > 0
1041	and eval "require $model") {	1174	and eval "require $model") {
1042	$MODEL = $model;	1175	$MODEL = $model;
1043	warn "AnyEvent: autoprobed model '$model', using it.\n" if $verbose > 1;	1176	warn "AnyEvent: autoprobed model '$model', using it.\n" if $VERBOSE >= 2;
1044	last;	1177	last;
1045	}	1178	}
1046	}	1179	}
1047		1180
1048	$MODEL	1181	$MODEL
…		…
1064		1197
1065	sub AUTOLOAD {	1198	sub AUTOLOAD {
1066	(my $func = $AUTOLOAD) =~ s/.*://;	1199	(my $func = $AUTOLOAD) =~ s/.*://;
1067		1200
1068	$method{$func}	1201	$method{$func}
1069	or croak "$func: not a valid method for AnyEvent objects";	1202	or Carp::croak "$func: not a valid method for AnyEvent objects";
1070		1203
1071	detect unless $MODEL;	1204	detect unless $MODEL;
1072		1205
1073	my $class = shift;	1206	my $class = shift;
1074	$class->$func (@_);	1207	$class->$func (@_);
1075	}	1208	}
1076		1209
1077	# utility function to dup a filehandle. this is used by many backends	1210	# utility function to dup a filehandle. this is used by many backends
1078	# to support binding more than one watcher per filehandle (they usually	1211	# 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).	1212	# allow only one watcher per fd, so we dup it to get a different one).
1080	sub _dupfh($$$$) {	1213	sub _dupfh($$;$$) {
1081	my ($poll, $fh, $r, $w) = @_;	1214	my ($poll, $fh, $r, $w) = @_;
1082		1215
1083	# cygwin requires the fh mode to be matching, unix doesn't	1216	# cygwin requires the fh mode to be matching, unix doesn't
1084	my ($rw, $mode) = $poll eq "r" ? ($r, "<")	1217	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		1218
1088	open my $fh2, "$mode&" . fileno $fh	1219	open my $fh2, $mode, $fh
1089	or die "cannot dup() filehandle: $!,";	1220	or die "AnyEvent->io: cannot dup() filehandle in mode '$poll': $!,";
1090		1221
1091	# we assume CLOEXEC is already set by perl in all important cases	1222	# we assume CLOEXEC is already set by perl in all important cases
1092		1223
1093	($fh2, $rw)	1224	($fh2, $rw)
1094	}	1225	}
1095		1226
1096	package AnyEvent::Base;	1227	package AnyEvent::Base;
1097		1228
1098	# default implementations for many methods	1229	# default implementations for many methods
1099		1230
1100	BEGIN {	1231	sub _time {
		1232	# probe for availability of Time::HiRes
1101	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {	1233	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {
		1234	warn "AnyEvent: using Time::HiRes for sub-second timing accuracy.\n" if $VERBOSE >= 8;
1102	*_time = \&Time::HiRes::time;	1235	*_time = \&Time::HiRes::time;
1103	# if (eval "use POSIX (); (POSIX::times())...	1236	# if (eval "use POSIX (); (POSIX::times())...
1104	} else {	1237	} else {
		1238	warn "AnyEvent: using built-in time(), WARNING, no sub-second resolution!\n" if $VERBOSE;
1105	*_time = sub { time }; # epic fail	1239	*_time = sub { time }; # epic fail
1106	}	1240	}
		1241
		1242	&_time
1107	}	1243	}
1108		1244
1109	sub time { _time }	1245	sub time { _time }
1110	sub now { _time }	1246	sub now { _time }
1111	sub now_update { }	1247	sub now_update { }
…		…
1116	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"	1252	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"
1117	}	1253	}
1118		1254
1119	# default implementation for ->signal	1255	# default implementation for ->signal
1120		1256
		1257	our $HAVE_ASYNC_INTERRUPT;
1121	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);	1258	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);
		1259	our (%SIG_ASY, %SIG_ASY_W);
		1260	our ($SIG_COUNT, $SIG_TW);
1122		1261
1123	sub _signal_exec {	1262	sub _signal_exec {
		1263	$HAVE_ASYNC_INTERRUPT
		1264	? $SIGPIPE_R->drain
1124	sysread $SIGPIPE_R, my $dummy, 4;	1265	: sysread $SIGPIPE_R, my $dummy, 9;
1125		1266
1126	while (%SIG_EV) {	1267	while (%SIG_EV) {
1127	for (keys %SIG_EV) {	1268	for (keys %SIG_EV) {
1128	delete $SIG_EV{$_};	1269	delete $SIG_EV{$_};
1129	$_->() for values %{ $SIG_CB{$_} \|\| {} };	1270	$_->() for values %{ $SIG_CB{$_} \|\| {} };
1130	}	1271	}
1131	}	1272	}
1132	}	1273	}
1133		1274
		1275	sub _signal {
		1276	my (undef, %arg) = @_;
		1277
		1278	my $signal = uc $arg{signal}
		1279	or Carp::croak "required option 'signal' is missing";
		1280
		1281	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
		1282
		1283	if ($HAVE_ASYNC_INTERRUPT) {
		1284	# async::interrupt
		1285
		1286	$SIG_ASY{$signal} \|\|= do {
		1287	my $asy = new Async::Interrupt
		1288	cb => sub { undef $SIG_EV{$signal} },
		1289	signal => $signal,
		1290	pipe => [$SIGPIPE_R->filenos],
		1291	;
		1292	$asy->pipe_autodrain (0);
		1293
		1294	$asy
		1295	};
		1296
		1297	} else {
		1298	# pure perl
		1299
		1300	$SIG{$signal} \|\|= sub {
		1301	local $!;
		1302	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;
		1303	undef $SIG_EV{$signal};
		1304	};
		1305
		1306	# can't do signal processing without introducing races in pure perl,
		1307	# so limit the signal latency.
		1308	++$SIG_COUNT;
		1309	$SIG_TW \|\|= AnyEvent->timer (
		1310	after => $MAX_SIGNAL_LATENCY,
		1311	interval => $MAX_SIGNAL_LATENCY,
		1312	cb => sub { }, # just for the PERL_ASYNC_CHECK
		1313	);
		1314	}
		1315
		1316	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
		1317	}
		1318
1134	sub signal {	1319	sub signal {
1135	my (undef, %arg) = @_;	1320	# probe for availability of Async::Interrupt
		1321	if (!$ENV{PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT} && eval "use Async::Interrupt 0.6 (); 1") {
		1322	warn "AnyEvent: using Async::Interrupt for race-free signal handling.\n" if $VERBOSE >= 8;
1136		1323
1137	unless ($SIGPIPE_R) {	1324	$HAVE_ASYNC_INTERRUPT = 1;
		1325	$SIGPIPE_R = new Async::Interrupt::EventPipe;
		1326	$SIG_IO = AnyEvent->io (fh => $SIGPIPE_R->fileno, poll => "r", cb => \&_signal_exec);
		1327
		1328	} else {
		1329	warn "AnyEvent: using emulated perl signal handling with latency timer.\n" if $VERBOSE >= 8;
		1330
1138	require Fcntl;	1331	require Fcntl;
1139		1332
1140	if (AnyEvent::WIN32) {	1333	if (AnyEvent::WIN32) {
1141	require AnyEvent::Util;	1334	require AnyEvent::Util;
1142		1335
…		…
1157	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";	1350	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";
1158		1351
1159	$SIG_IO = AnyEvent->io (fh => $SIGPIPE_R, poll => "r", cb => \&_signal_exec);	1352	$SIG_IO = AnyEvent->io (fh => $SIGPIPE_R, poll => "r", cb => \&_signal_exec);
1160	}	1353	}
1161		1354
1162	my $signal = uc $arg{signal}	1355	*signal = \&_signal;
1163	or Carp::croak "required option 'signal' is missing";	1356	&signal
1164
1165	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
1166	$SIG{$signal} \|\|= sub {
1167	local $!;
1168	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;
1169	undef $SIG_EV{$signal};
1170	};
1171
1172	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
1173	}	1357	}
1174		1358
1175	sub AnyEvent::Base::signal::DESTROY {	1359	sub AnyEvent::Base::signal::DESTROY {
1176	my ($signal, $cb) = @{$_[0]};	1360	my ($signal, $cb) = @{$_[0]};
1177		1361
		1362	undef $SIG_TW
		1363	unless --$SIG_COUNT;
		1364
1178	delete $SIG_CB{$signal}{$cb};	1365	delete $SIG_CB{$signal}{$cb};
1179		1366
		1367	$HAVE_ASYNC_INTERRUPT
		1368	? delete $SIG_ASY{$signal}
1180	# delete doesn't work with older perls - they then	1369	: # delete doesn't work with older perls - they then
1181	# print weird messages, or just unconditionally exit	1370	# print weird messages, or just unconditionally exit
1182	# instead of getting the default action.	1371	# instead of getting the default action.
		1372	undef $SIG{$signal}
1183	undef $SIG{$signal} unless keys %{ $SIG_CB{$signal} };	1373	unless keys %{ $SIG_CB{$signal} };
1184	}	1374	}
1185		1375
1186	# default implementation for ->child	1376	# default implementation for ->child
1187		1377
1188	our %PID_CB;	1378	our %PID_CB;
…		…
1190	our $CHLD_DELAY_W;	1380	our $CHLD_DELAY_W;
1191	our $WNOHANG;	1381	our $WNOHANG;
1192		1382
1193	sub _sigchld {	1383	sub _sigchld {
1194	while (0 < (my $pid = waitpid -1, $WNOHANG)) {	1384	while (0 < (my $pid = waitpid -1, $WNOHANG)) {
		1385	$_->($pid, $?)
1195	$_->($pid, $?) for (values %{ $PID_CB{$pid} \|\| {} }),	1386	for values %{ $PID_CB{$pid} \|\| {} },
1196	(values %{ $PID_CB{0} \|\| {} });	1387	values %{ $PID_CB{0} \|\| {} };
1197	}	1388	}
1198	}	1389	}
1199		1390
1200	sub child {	1391	sub child {
1201	my (undef, %arg) = @_;	1392	my (undef, %arg) = @_;
…		…
1203	defined (my $pid = $arg{pid} + 0)	1394	defined (my $pid = $arg{pid} + 0)
1204	or Carp::croak "required option 'pid' is missing";	1395	or Carp::croak "required option 'pid' is missing";
1205		1396
1206	$PID_CB{$pid}{$arg{cb}} = $arg{cb};	1397	$PID_CB{$pid}{$arg{cb}} = $arg{cb};
1207		1398
		1399	# WNOHANG is almost cetrainly 1 everywhere
		1400	$WNOHANG \|\|= $^O =~ /^(?:openbsd\|netbsd\|linux\|freebsd\|cygwin\|MSWin32)$/
		1401	? 1
1208	$WNOHANG \|\|= eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } \|\| 1;	1402	: eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } \|\| 1;
1209		1403
1210	unless ($CHLD_W) {	1404	unless ($CHLD_W) {
1211	$CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld);	1405	$CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld);
1212	# child could be a zombie already, so make at least one round	1406	# child could be a zombie already, so make at least one round
1213	&_sigchld;	1407	&_sigchld;
…		…
1265		1459
1266	our @ISA = AnyEvent::CondVar::Base::;	1460	our @ISA = AnyEvent::CondVar::Base::;
1267		1461
1268	package AnyEvent::CondVar::Base;	1462	package AnyEvent::CondVar::Base;
1269		1463
1270	use overload	1464	#use overload
1271	'&{}' => sub { my $self = shift; sub { $self->send (@_) } },	1465	# '&{}' => sub { my $self = shift; sub { $self->send (@_) } },
1272	fallback => 1;	1466	# fallback => 1;
		1467
		1468	# save 300+ kilobytes by dirtily hardcoding overloading
		1469	${"AnyEvent::CondVar::Base::OVERLOAD"}{dummy}++; # Register with magic by touching.
		1470	*{'AnyEvent::CondVar::Base::()'} = sub { }; # "Make it findable via fetchmethod."
		1471	*{'AnyEvent::CondVar::Base::(&{}'} = sub { my $self = shift; sub { $self->send (@_) } }; # &{}
		1472	${'AnyEvent::CondVar::Base::()'} = 1; # fallback
		1473
		1474	our $WAITING;
1273		1475
1274	sub _send {	1476	sub _send {
1275	# nop	1477	# nop
1276	}	1478	}
1277		1479
…		…
1290	sub ready {	1492	sub ready {
1291	$_[0]{_ae_sent}	1493	$_[0]{_ae_sent}
1292	}	1494	}
1293		1495
1294	sub _wait {	1496	sub _wait {
		1497	$WAITING
		1498	and !$_[0]{_ae_sent}
		1499	and Carp::croak "AnyEvent::CondVar: recursive blocking wait detected";
		1500
		1501	local $WAITING = 1;
1295	AnyEvent->one_event while !$_[0]{_ae_sent};	1502	AnyEvent->one_event while !$_[0]{_ae_sent};
1296	}	1503	}
1297		1504
1298	sub recv {	1505	sub recv {
1299	$_[0]->_wait;	1506	$_[0]->_wait;
…		…
1361	C<PERL_ANYEVENT_MODEL>.	1568	C<PERL_ANYEVENT_MODEL>.
1362		1569
1363	When set to C<2> or higher, cause AnyEvent to report to STDERR which event	1570	When set to C<2> or higher, cause AnyEvent to report to STDERR which event
1364	model it chooses.	1571	model it chooses.
1365		1572
		1573	When set to C<8> or higher, then AnyEvent will report extra information on
		1574	which optional modules it loads and how it implements certain features.
		1575
1366	=item C<PERL_ANYEVENT_STRICT>	1576	=item C<PERL_ANYEVENT_STRICT>
1367		1577
1368	AnyEvent does not do much argument checking by default, as thorough	1578	AnyEvent does not do much argument checking by default, as thorough
1369	argument checking is very costly. Setting this variable to a true value	1579	argument checking is very costly. Setting this variable to a true value
1370	will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly	1580	will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly
1371	check the arguments passed to most method calls. If it finds any problems	1581	check the arguments passed to most method calls. If it finds any problems,
1372	it will croak.	1582	it will croak.
1373		1583
1374	In other words, enables "strict" mode.	1584	In other words, enables "strict" mode.
1375		1585
1376	Unlike C<use strict>, it is definitely recommended ot keep it off in	1586	Unlike C<use strict> (or it's modern cousin, C<< use L<common::sense>
1377	production. Keeping C<PERL_ANYEVENT_STRICT=1> in your environment while	1587	>>, it is definitely recommended to keep it off in production. Keeping
1378	developing programs can be very useful, however.	1588	C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs
		1589	can be very useful, however.
1379		1590
1380	=item C<PERL_ANYEVENT_MODEL>	1591	=item C<PERL_ANYEVENT_MODEL>
1381		1592
1382	This can be used to specify the event model to be used by AnyEvent, before	1593	This can be used to specify the event model to be used by AnyEvent, before
1383	auto detection and -probing kicks in. It must be a string consisting	1594	auto detection and -probing kicks in. It must be a string consisting
…		…
1426		1637
1427	=item C<PERL_ANYEVENT_MAX_FORKS>	1638	=item C<PERL_ANYEVENT_MAX_FORKS>
1428		1639
1429	The maximum number of child processes that C<AnyEvent::Util::fork_call>	1640	The maximum number of child processes that C<AnyEvent::Util::fork_call>
1430	will create in parallel.	1641	will create in parallel.
		1642
		1643	=item C<PERL_ANYEVENT_MAX_OUTSTANDING_DNS>
		1644
		1645	The default value for the C<max_outstanding> parameter for the default DNS
		1646	resolver - this is the maximum number of parallel DNS requests that are
		1647	sent to the DNS server.
		1648
		1649	=item C<PERL_ANYEVENT_RESOLV_CONF>
		1650
		1651	The file to use instead of F</etc/resolv.conf> (or OS-specific
		1652	configuration) in the default resolver. When set to the empty string, no
		1653	default config will be used.
		1654
		1655	=item C<PERL_ANYEVENT_CA_FILE>, C<PERL_ANYEVENT_CA_PATH>.
		1656
		1657	When neither C<ca_file> nor C<ca_path> was specified during
		1658	L<AnyEvent::TLS> context creation, and either of these environment
		1659	variables exist, they will be used to specify CA certificate locations
		1660	instead of a system-dependent default.
		1661
		1662	=item C<PERL_ANYEVENT_AVOID_GUARD> and C<PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT>
		1663
		1664	When these are set to C<1>, then the respective modules are not
		1665	loaded. Mostly good for testing AnyEvent itself.
1431		1666
1432	=back	1667	=back
1433		1668
1434	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE	1669	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE
1435		1670
…		…
1680	EV/Any 100000 224 2.88 0.34 0.27 EV + AnyEvent watchers	1915	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	1916	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	1917	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	1918	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	1919	Event/Any 16000 590 35.85 31.55 1.06 Event + AnyEvent watchers
		1920	IOAsync/Any 16000 989 38.10 32.77 11.13 via IO::Async::Loop::IO_Poll
		1921	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	1922	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	1923	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	1924	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	1925	POE/Select 2000 6027 94.54 809.13 579.80 via POE::Loop::Select
1689		1926
…		…
1718	performance becomes really bad with lots of file descriptors (and few of	1955	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.	1956	them active), of course, but this was not subject of this benchmark.
1720		1957
1721	The C<Event> module has a relatively high setup and callback invocation	1958	The C<Event> module has a relatively high setup and callback invocation
1722	cost, but overall scores in on the third place.	1959	cost, but overall scores in on the third place.
		1960
		1961	C<IO::Async> performs admirably well, about on par with C<Event>, even
		1962	when using its pure perl backend.
1723		1963
1724	C<Glib>'s memory usage is quite a bit higher, but it features a	1964	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	1965	faster callback invocation and overall ends up in the same class as
1726	C<Event>. However, Glib scales extremely badly, doubling the number of	1966	C<Event>. However, Glib scales extremely badly, doubling the number of
1727	watchers increases the processing time by more than a factor of four,	1967	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	2045	it to another server. This includes deleting the old timeout and creating
1806	a new one that moves the timeout into the future.	2046	a new one that moves the timeout into the future.
1807		2047
1808	=head3 Results	2048	=head3 Results
1809		2049
1810	name sockets create request	2050	name sockets create request
1811	EV 20000 69.01 11.16	2051	EV 20000 69.01 11.16
1812	Perl 20000 73.32 35.87	2052	Perl 20000 73.32 35.87
		2053	IOAsync 20000 157.00 98.14 epoll
		2054	IOAsync 20000 159.31 616.06 poll
1813	Event 20000 212.62 257.32	2055	Event 20000 212.62 257.32
1814	Glib 20000 651.16 1896.30	2056	Glib 20000 651.16 1896.30
1815	POE 20000 349.67 12317.24 uses POE::Loop::Event	2057	POE 20000 349.67 12317.24 uses POE::Loop::Event
1816		2058
1817	=head3 Discussion	2059	=head3 Discussion
1818		2060
1819	This benchmark I<does> measure scalability and overall performance of the	2061	This benchmark I<does> measure scalability and overall performance of the
1820	particular event loop.	2062	particular event loop.
…		…
1822	EV is again fastest. Since it is using epoll on my system, the setup time	2064	EV is again fastest. Since it is using epoll on my system, the setup time
1823	is relatively high, though.	2065	is relatively high, though.
1824		2066
1825	Perl surprisingly comes second. It is much faster than the C-based event	2067	Perl surprisingly comes second. It is much faster than the C-based event
1826	loops Event and Glib.	2068	loops Event and Glib.
		2069
		2070	IO::Async performs very well when using its epoll backend, and still quite
		2071	good compared to Glib when using its pure perl backend.
1827		2072
1828	Event suffers from high setup time as well (look at its code and you will	2073	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	2074	understand why). Callback invocation also has a high overhead compared to
1830	the C<< $_->() for .. >>-style loop that the Perl event loop uses. Event	2075	the C<< $_->() for .. >>-style loop that the Perl event loop uses. Event
1831	uses select or poll in basically all documented configurations.	2076	uses select or poll in basically all documented configurations.
…		…
1900		2145
1901	Recently I was told about the benchmark in the IO::Lambda manpage, which	2146	Recently I was told about the benchmark in the IO::Lambda manpage, which
1902	could be misinterpreted to make AnyEvent look bad. In fact, the benchmark	2147	could be misinterpreted to make AnyEvent look bad. In fact, the benchmark
1903	simply compares IO::Lambda with POE, and IO::Lambda looks better (which	2148	simply compares IO::Lambda with POE, and IO::Lambda looks better (which
1904	shouldn't come as a surprise to anybody). As such, the benchmark is	2149	shouldn't come as a surprise to anybody). As such, the benchmark is
1905	fine, and shows that the AnyEvent backend from IO::Lambda isn't very	2150	fine, and mostly shows that the AnyEvent backend from IO::Lambda isn't
1906	optimal. But how would AnyEvent compare when used without the extra	2151	very optimal. But how would AnyEvent compare when used without the extra
1907	baggage? To explore this, I wrote the equivalent benchmark for AnyEvent.	2152	baggage? To explore this, I wrote the equivalent benchmark for AnyEvent.
1908		2153
1909	The benchmark itself creates an echo-server, and then, for 500 times,	2154	The benchmark itself creates an echo-server, and then, for 500 times,
1910	connects to the echo server, sends a line, waits for the reply, and then	2155	connects to the echo server, sends a line, waits for the reply, and then
1911	creates the next connection. This is a rather bad benchmark, as it doesn't	2156	creates the next connection. This is a rather bad benchmark, as it doesn't
1912	test the efficiency of the framework, but it is a benchmark nevertheless.	2157	test the efficiency of the framework or much non-blocking I/O, but it is a
		2158	benchmark nevertheless.
1913		2159
1914	name runtime	2160	name runtime
1915	Lambda/select 0.330 sec	2161	Lambda/select 0.330 sec
1916	+ optimized 0.122 sec	2162	+ optimized 0.122 sec
1917	Lambda/AnyEvent 0.327 sec	2163	Lambda/AnyEvent 0.327 sec
…		…
1923		2169
1924	AnyEvent/select/nb 0.085 sec	2170	AnyEvent/select/nb 0.085 sec
1925	AnyEvent/EV/nb 0.068 sec	2171	AnyEvent/EV/nb 0.068 sec
1926	+state machine 0.134 sec	2172	+state machine 0.134 sec
1927		2173
1928	The benchmark is also a bit unfair (my fault) - the IO::Lambda	2174	The benchmark is also a bit unfair (my fault): the IO::Lambda/POE
1929	benchmarks actually make blocking connects and use 100% blocking I/O,	2175	benchmarks actually make blocking connects and use 100% blocking I/O,
1930	defeating the purpose of an event-based solution. All of the newly	2176	defeating the purpose of an event-based solution. All of the newly
1931	written AnyEvent benchmarks use 100% non-blocking connects (using	2177	written AnyEvent benchmarks use 100% non-blocking connects (using
1932	AnyEvent::Socket::tcp_connect and the asynchronous pure perl DNS	2178	AnyEvent::Socket::tcp_connect and the asynchronous pure perl DNS
1933	resolver), so AnyEvent is at a disadvantage here as non-blocking connects	2179	resolver), so AnyEvent is at a disadvantage here, as non-blocking connects
1934	generally require a lot more bookkeeping and event handling than blocking	2180	generally require a lot more bookkeeping and event handling than blocking
1935	connects (which involve a single syscall only).	2181	connects (which involve a single syscall only).
1936		2182
1937	The last AnyEvent benchmark additionally uses L<AnyEvent::Handle>, which	2183	The last AnyEvent benchmark additionally uses L<AnyEvent::Handle>, which
1938	offers similar expressive power as POE and IO::Lambda (using conventional	2184	offers similar expressive power as POE and IO::Lambda, using conventional
1939	Perl syntax), which means both the echo server and the client are 100%	2185	Perl syntax. This means that both the echo server and the client are 100%
1940	non-blocking w.r.t. I/O, further placing it at a disadvantage.	2186	non-blocking, further placing it at a disadvantage.
1941		2187
1942	As you can see, AnyEvent + EV even beats the hand-optimised "raw sockets	2188	As you can see, the AnyEvent + EV combination even beats the
1943	benchmark", while AnyEvent + its pure perl backend easily beats	2189	hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl
1944	IO::Lambda and POE.	2190	backend easily beats IO::Lambda and POE.
1945		2191
1946	And even the 100% non-blocking version written using the high-level (and	2192	And even the 100% non-blocking version written using the high-level (and
1947	slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda,	2193	slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda by a
1948	even thought it does all of DNS, tcp-connect and socket I/O in a	2194	large margin, even though it does all of DNS, tcp-connect and socket I/O
1949	non-blocking way.	2195	in a non-blocking way.
1950		2196
1951	The two AnyEvent benchmarks can be found as F<eg/ae0.pl> and F<eg/ae2.pl>	2197	The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and
1952	in the AnyEvent distribution, the remaining benchmarks are part of the	2198	F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are
1953	IO::lambda distribution and were used without any changes.	2199	part of the IO::lambda distribution and were used without any changes.
1954		2200
1955		2201
1956	=head1 SIGNALS	2202	=head1 SIGNALS
1957		2203
1958	AnyEvent currently installs handlers for these signals:	2204	AnyEvent currently installs handlers for these signals:
…		…
1962	=item SIGCHLD	2208	=item SIGCHLD
1963		2209
1964	A handler for C<SIGCHLD> is installed by AnyEvent's child watcher	2210	A handler for C<SIGCHLD> is installed by AnyEvent's child watcher
1965	emulation for event loops that do not support them natively. Also, some	2211	emulation for event loops that do not support them natively. Also, some
1966	event loops install a similar handler.	2212	event loops install a similar handler.
		2213
		2214	Additionally, when AnyEvent is loaded and SIGCHLD is set to IGNORE, then
		2215	AnyEvent will reset it to default, to avoid losing child exit statuses.
1967		2216
1968	=item SIGPIPE	2217	=item SIGPIPE
1969		2218
1970	A no-op handler is installed for C<SIGPIPE> when C<$SIG{PIPE}> is C<undef>	2219	A no-op handler is installed for C<SIGPIPE> when C<$SIG{PIPE}> is C<undef>
1971	when AnyEvent gets loaded.	2220	when AnyEvent gets loaded.
…		…
1983		2232
1984	=back	2233	=back
1985		2234
1986	=cut	2235	=cut
1987		2236
		2237	undef $SIG{CHLD}
		2238	if $SIG{CHLD} eq 'IGNORE';
		2239
1988	$SIG{PIPE} = sub { }	2240	$SIG{PIPE} = sub { }
1989	unless defined $SIG{PIPE};	2241	unless defined $SIG{PIPE};
		2242
		2243	=head1 RECOMMENDED/OPTIONAL MODULES
		2244
		2245	One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and
		2246	it's built-in modules) are required to use it.
		2247
		2248	That does not mean that AnyEvent won't take advantage of some additional
		2249	modules if they are installed.
		2250
		2251	This section epxlains which additional modules will be used, and how they
		2252	affect AnyEvent's operetion.
		2253
		2254	=over 4
		2255
		2256	=item L<Async::Interrupt>
		2257
		2258	This slightly arcane module is used to implement fast signal handling: To
		2259	my knowledge, there is no way to do completely race-free and quick
		2260	signal handling in pure perl. To ensure that signals still get
		2261	delivered, AnyEvent will start an interval timer to wake up perl (and
		2262	catch the signals) with soemd elay (default is 10 seconds, look for
		2263	C<$AnyEvent::MAX_SIGNAL_LATENCY>).
		2264
		2265	If this module is available, then it will be used to implement signal
		2266	catching, which means that signals will not be delayed, and the event loop
		2267	will not be interrupted regularly, which is more efficient (And good for
		2268	battery life on laptops).
		2269
		2270	This affects not just the pure-perl event loop, but also other event loops
		2271	that have no signal handling on their own (e.g. Glib, Tk, Qt).
		2272
		2273	=item L<EV>
		2274
		2275	This module isn't really "optional", as it is simply one of the backend
		2276	event loops that AnyEvent can use. However, it is simply the best event
		2277	loop available in terms of features, speed and stability: It supports
		2278	the AnyEvent API optimally, implements all the watcher types in XS, does
		2279	automatic timer adjustments even when no monotonic clock is available,
		2280	can take avdantage of advanced kernel interfaces such as C<epoll> and
		2281	C<kqueue>, and is the fastest backend I<by far>. You can even embed
		2282	L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>).
		2283
		2284	=item L<Guard>
		2285
		2286	The guard module, when used, will be used to implement
		2287	C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a
		2288	lot less memory), but otherwise doesn't affect guard operation much. It is
		2289	purely used for performance.
		2290
		2291	=item L<JSON> and L<JSON::XS>
		2292
		2293	This module is required when you want to read or write JSON data via
		2294	L<AnyEvent::Handle>. It is also written in pure-perl, but can take
		2295	advantage of the ulta-high-speed L<JSON::XS> module when it is installed.
		2296
		2297	In fact, L<AnyEvent::Handle> will use L<JSON::XS> by default if it is
		2298	installed.
		2299
		2300	=item L<Net::SSLeay>
		2301
		2302	Implementing TLS/SSL in Perl is certainly interesting, but not very
		2303	worthwhile: If this module is installed, then L<AnyEvent::Handle> (with
		2304	the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL.
		2305
		2306	=item L<Time::HiRes>
		2307
		2308	This module is part of perl since release 5.008. It will be used when the
		2309	chosen event library does not come with a timing source on it's own. The
		2310	pure-perl event loop (L<AnyEvent::Impl::Perl>) will additionally use it to
		2311	try to use a monotonic clock for timing stability.
		2312
		2313	=back
1990		2314
1991		2315
1992	=head1 FORK	2316	=head1 FORK
1993		2317
1994	Most event libraries are not fork-safe. The ones who are usually are	2318	Most event libraries are not fork-safe. The ones who are usually are
1995	because they rely on inefficient but fork-safe C<select> or C<poll>	2319	because they rely on inefficient but fork-safe C<select> or C<poll>
1996	calls. Only L<EV> is fully fork-aware.	2320	calls. Only L<EV> is fully fork-aware.
1997		2321
1998	If you have to fork, you must either do so I<before> creating your first	2322	If you have to fork, you must either do so I<before> creating your first
1999	watcher OR you must not use AnyEvent at all in the child.	2323	watcher OR you must not use AnyEvent at all in the child OR you must do
		2324	something completely out of the scope of AnyEvent.
2000		2325
2001		2326
2002	=head1 SECURITY CONSIDERATIONS	2327	=head1 SECURITY CONSIDERATIONS
2003		2328
2004	AnyEvent can be forced to load any event model via	2329	AnyEvent can be forced to load any event model via
…		…
2018	Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can	2343	Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can
2019	be used to probe what backend is used and gain other information (which is	2344	be used to probe what backend is used and gain other information (which is
2020	probably even less useful to an attacker than PERL_ANYEVENT_MODEL), and	2345	probably even less useful to an attacker than PERL_ANYEVENT_MODEL), and
2021	$ENV{PERL_ANYEVENT_STRICT}.	2346	$ENV{PERL_ANYEVENT_STRICT}.
2022		2347
		2348	Note that AnyEvent will remove I<all> environment variables starting with
		2349	C<PERL_ANYEVENT_> from C<%ENV> when it is loaded while taint mode is
		2350	enabled.
		2351
2023		2352
2024	=head1 BUGS	2353	=head1 BUGS
2025		2354
2026	Perl 5.8 has numerous memleaks that sometimes hit this module and are hard	2355	Perl 5.8 has numerous memleaks that sometimes hit this module and are hard
2027	to work around. If you suffer from memleaks, first upgrade to Perl 5.10	2356	to work around. If you suffer from memleaks, first upgrade to Perl 5.10
…		…
2038	L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.	2367	L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.
2039		2368
2040	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,	2369	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,
2041	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,	2370	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,
2042	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,	2371	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,
2043	L<AnyEvent::Impl::POE>.	2372	L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>.
2044		2373
2045	Non-blocking file handles, sockets, TCP clients and	2374	Non-blocking file handles, sockets, TCP clients and
2046	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>.	2375	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.
2047		2376
2048	Asynchronous DNS: L<AnyEvent::DNS>.	2377	Asynchronous DNS: L<AnyEvent::DNS>.
2049		2378
2050	Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>,	2379	Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>,
		2380	L<Coro::Event>,
2051		2381
2052	Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>, L<AnyEvent::DNS>.	2382	Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::XMPP>,
		2383	L<AnyEvent::HTTP>.
2053		2384
2054		2385
2055	=head1 AUTHOR	2386	=head1 AUTHOR
2056		2387
2057	Marc Lehmann <schmorp@schmorp.de>	2388	Marc Lehmann <schmorp@schmorp.de>

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Comparing AnyEvent/lib/AnyEvent.pm (file contents): Revision 1.217 by root, Tue Jun 23 23:37:32 2009 UTC vs. Revision 1.245 by root, Sat Jul 18 05:19:09 2009 UTC

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Comparing AnyEvent/lib/AnyEvent.pm (file contents):
Revision 1.217 by root, Tue Jun 23 23:37:32 2009 UTC vs.
Revision 1.245 by root, Sat Jul 18 05:19:09 2009 UTC