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

Comparing AnyEvent/lib/AnyEvent.pm (file contents):
Revision 1.206 by root, Mon Apr 20 14:34:18 2009 UTC vs.
Revision 1.241 by root, Fri Jul 17 18:08:35 2009 UTC

…		…
1	=head1 NAME	1	=head1 NAME
2		2
3	AnyEvent - provide framework for multiple event loops	3	AnyEvent - provide framework for multiple event loops
4		4
5	EV, Event, Glib, Tk, Perl, Event::Lib, Qt, POE - various supported event loops	5	EV, Event, Glib, Tk, Perl, Event::Lib, Qt and POE are various supported
		6	event loops.
6		7
7	=head1 SYNOPSIS	8	=head1 SYNOPSIS
8		9
9	use AnyEvent;	10	use AnyEvent;
10		11
		12	# file descriptor readable
11	my $w = AnyEvent->io (fh => $fh, poll => "r\|w", cb => sub { ... });	13	my $w = AnyEvent->io (fh => $fh, poll => "r", cb => sub { ... });
12		14
		15	# one-shot or repeating timers
13	my $w = AnyEvent->timer (after => $seconds, cb => sub { ... });	16	my $w = AnyEvent->timer (after => $seconds, cb => sub { ... });
14	my $w = AnyEvent->timer (after => $seconds, interval => $seconds, cb => ...	17	my $w = AnyEvent->timer (after => $seconds, interval => $seconds, cb => ...
15		18
16	print AnyEvent->now; # prints current event loop time	19	print AnyEvent->now; # prints current event loop time
17	print AnyEvent->time; # think Time::HiRes::time or simply CORE::time.	20	print AnyEvent->time; # think Time::HiRes::time or simply CORE::time.
18		21
		22	# POSIX signal
19	my $w = AnyEvent->signal (signal => "TERM", cb => sub { ... });	23	my $w = AnyEvent->signal (signal => "TERM", cb => sub { ... });
20		24
		25	# child process exit
21	my $w = AnyEvent->child (pid => $pid, cb => sub {	26	my $w = AnyEvent->child (pid => $pid, cb => sub {
22	my ($pid, $status) = @_;	27	my ($pid, $status) = @_;
23	...	28	...
24	});	29	});
		30
		31	# called when event loop idle (if applicable)
		32	my $w = AnyEvent->idle (cb => sub { ... });
25		33
26	my $w = AnyEvent->condvar; # stores whether a condition was flagged	34	my $w = AnyEvent->condvar; # stores whether a condition was flagged
27	$w->send; # wake up current and all future recv's	35	$w->send; # wake up current and all future recv's
28	$w->recv; # enters "main loop" till $condvar gets ->send	36	$w->recv; # enters "main loop" till $condvar gets ->send
29	# use a condvar in callback mode:	37	# use a condvar in callback mode:
168	=head2 I/O WATCHERS	176	=head2 I/O WATCHERS
169		177
170	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
171	with the following mandatory key-value pairs as arguments:	179	with the following mandatory key-value pairs as arguments:
172		180
173	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
174	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
175	handle). Note that only file handles pointing to things for which	183	handle). Note that only file handles pointing to things for which
176	non-blocking operation makes sense are allowed. This includes sockets,	184	non-blocking operation makes sense are allowed. This includes sockets,
177	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
178	or block devices.	186	or block devices.
…		…
384		392
385	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
386	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
387	have exited already (and no SIGCHLD will be sent anymore).	395	have exited already (and no SIGCHLD will be sent anymore).
388		396
389	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
390	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
391	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.
392		403
393	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
394	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
395	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>).
396		408
397	Example: fork a process and wait for it	409	Example: fork a process and wait for it
398		410
399	my $done = AnyEvent->condvar;	411	my $done = AnyEvent->condvar;
400		412
…		…
410	);	422	);
411		423
412	# do something else, then wait for process exit	424	# do something else, then wait for process exit
413	$done->recv;	425	$done->recv;
414		426
		427	=head2 IDLE WATCHERS
		428
		429	Sometimes there is a need to do something, but it is not so important
		430	to do it instantly, but only when there is nothing better to do. This
		431	"nothing better to do" is usually defined to be "no other events need
		432	attention by the event loop".
		433
		434	Idle watchers ideally get invoked when the event loop has nothing
		435	better to do, just before it would block the process to wait for new
		436	events. Instead of blocking, the idle watcher is invoked.
		437
		438	Most event loops unfortunately do not really support idle watchers (only
		439	EV, Event and Glib do it in a usable fashion) - for the rest, AnyEvent
		440	will simply call the callback "from time to time".
		441
		442	Example: read lines from STDIN, but only process them when the
		443	program is otherwise idle:
		444
		445	my @lines; # read data
		446	my $idle_w;
		447	my $io_w = AnyEvent->io (fh => \*STDIN, poll => 'r', cb => sub {
		448	push @lines, scalar <STDIN>;
		449
		450	# start an idle watcher, if not already done
		451	$idle_w \|\|= AnyEvent->idle (cb => sub {
		452	# handle only one line, when there are lines left
		453	if (my $line = shift @lines) {
		454	print "handled when idle: $line";
		455	} else {
		456	# otherwise disable the idle watcher again
		457	undef $idle_w;
		458	}
		459	});
		460	});
		461
415	=head2 CONDITION VARIABLES	462	=head2 CONDITION VARIABLES
416		463
417	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
418	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
419	will actively watch for new events and call your callbacks.	466	will actively watch for new events and call your callbacks.
420		467
421	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
422	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).
423		470
424	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
425	because they represent a condition that must become true.	472	because they represent a condition that must become true.
426		473
		474	Now is probably a good time to look at the examples further below.
		475
427	Condition variables can be created by calling the C<< AnyEvent->condvar	476	Condition variables can be created by calling the C<< AnyEvent->condvar
428	>> method, usually without arguments. The only argument pair allowed is	477	>> method, usually without arguments. The only argument pair allowed is
429
430	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
431	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
432	the results).	480	the results).
433		481
434	After creation, the condition variable is "false" until it becomes "true"	482	After creation, the condition variable is "false" until it becomes "true"
…		…
483	after => 1,	531	after => 1,
484	cb => sub { $result_ready->send },	532	cb => sub { $result_ready->send },
485	);	533	);
486		534
487	# this "blocks" (while handling events) till the callback	535	# this "blocks" (while handling events) till the callback
488	# calls send	536	# calls -<send
489	$result_ready->recv;	537	$result_ready->recv;
490		538
491	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
492	condition variables are also code references.	540	variables are also callable directly.
493		541
494	my $done = AnyEvent->condvar;	542	my $done = AnyEvent->condvar;
495	my $delay = AnyEvent->timer (after => 5, cb => $done);	543	my $delay = AnyEvent->timer (after => 5, cb => $done);
496	$done->recv;	544	$done->recv;
497		545
…		…
503		551
504	...	552	...
505		553
506	my @info = $couchdb->info->recv;	554	my @info = $couchdb->info->recv;
507		555
508	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
509	results are available:	557	results are available:
510		558
511	$couchdb->info->cb (sub {	559	$couchdb->info->cb (sub {
512	my @info = $_[0]->recv;	560	my @info = $_[0]->recv;
513	});	561	});
…		…
531	immediately from within send.	579	immediately from within send.
532		580
533	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
534	future C<< ->recv >> calls.	582	future C<< ->recv >> calls.
535		583
536	Condition variables are overloaded so one can call them directly	584	Condition variables are overloaded so one can call them directly (as if
537	(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
538	C<send>. Note, however, that many C-based event loops do not handle	586	C<send>.
539	overloading, so as tempting as it may be, passing a condition variable
540	instead of a callback does not work. Both the pure perl and EV loops
541	support overloading, however, as well as all functions that use perl to
542	invoke a callback (as in L<AnyEvent::Socket> and L<AnyEvent::DNS> for
543	example).
544		587
545	=item $cv->croak ($error)	588	=item $cv->croak ($error)
546		589
547	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
548	C<Carp::croak> with the given error message/object/scalar.	591	C<Carp::croak> with the given error message/object/scalar.
549		592
550	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
551	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.
552		599
553	=item $cv->begin ([group callback])	600	=item $cv->begin ([group callback])
554		601
555	=item $cv->end	602	=item $cv->end
556
557	These two methods are EXPERIMENTAL and MIGHT CHANGE.
558		603
559	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
560	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
561	to use a condition variable for the whole process.	606	to use a condition variable for the whole process.
562		607
…		…
564	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
565	>>, 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
566	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
567	callback was set, C<send> will be called without any arguments.	612	callback was set, C<send> will be called without any arguments.
568		613
569	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:
570		645
571	my $cv = AnyEvent->condvar;	646	my $cv = AnyEvent->condvar;
572		647
573	my %result;	648	my %result;
574	$cv->begin (sub { $cv->send (\%result) });	649	$cv->begin (sub { $cv->send (\%result) });
…		…
594	loop, which serves two important purposes: first, it sets the callback	669	loop, which serves two important purposes: first, it sets the callback
595	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
596	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
597	doesn't execute once).	672	doesn't execute once).
598		673
599	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
600	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
601	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
602	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>.
603		679
604	=back	680	=back
605		681
606	=head3 METHODS FOR CONSUMERS	682	=head3 METHODS FOR CONSUMERS
607		683
…		…
623	function will call C<croak>.	699	function will call C<croak>.
624		700
625	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,
626	in scalar context only the first one will be returned.	702	in scalar context only the first one will be returned.
627		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
628	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
629	(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
630	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
631	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
632	condition variables with some kind of request results and supporting	715	condition variables with some kind of request results and supporting
633	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,
634	while still supporting blocking waits if the caller so desires).	717	while still supporting blocking waits if the caller so desires).
635		718
636	Another reason I<never> to C<< ->recv >> in a module is that you cannot
637	sensibly have two C<< ->recv >>'s in parallel, as that would require
638	multiple interpreters or coroutines/threads, none of which C<AnyEvent>
639	can supply.
640
641	The L<Coro> module, however, I<can> and I<does> supply coroutines and, in
642	fact, L<Coro::AnyEvent> replaces AnyEvent's condvars by coroutine-safe
643	versions and also integrates coroutines into AnyEvent, making blocking
644	C<< ->recv >> calls perfectly safe as long as they are done from another
645	coroutine (one that doesn't run the event loop).
646
647	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
648	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
649	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
650	waits otherwise.	722	waits otherwise.
651		723
…		…
664	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
665	is guaranteed not to block.	737	is guaranteed not to block.
666		738
667	=back	739	=back
668		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
669	=head1 GLOBAL VARIABLES AND FUNCTIONS	808	=head1 GLOBAL VARIABLES AND FUNCTIONS
670		809
		810	These are not normally required to use AnyEvent, but can be useful to
		811	write AnyEvent extension modules.
		812
671	=over 4	813	=over 4
672		814
673	=item $AnyEvent::MODEL	815	=item $AnyEvent::MODEL
674		816
675	Contains C<undef> until the first watcher is being created. Then it	817	Contains C<undef> until the first watcher is being created, before the
		818	backend has been autodetected.
		819
676	contains the event model that is being used, which is the name of the	820	Afterwards it contains the event model that is being used, which is the
677	Perl class implementing the model. This class is usually one of the	821	name of the Perl class implementing the model. This class is usually one
678	C<AnyEvent::Impl:xxx> modules, but can be any other class in the case	822	of the C<AnyEvent::Impl:xxx> modules, but can be any other class in the
679	AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode>).	823	case AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode> it
680		824	will be C<urxvt::anyevent>).
681	The known classes so far are:
682
683	AnyEvent::Impl::EV based on EV (an interface to libev, best choice).
684	AnyEvent::Impl::Event based on Event, second best choice.
685	AnyEvent::Impl::Perl pure-perl implementation, fast and portable.
686	AnyEvent::Impl::Glib based on Glib, third-best choice.
687	AnyEvent::Impl::Tk based on Tk, very bad choice.
688	AnyEvent::Impl::Qt based on Qt, cannot be autoprobed (see its docs).
689	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
690	AnyEvent::Impl::POE based on POE, not generic enough for full support.
691
692	There is no support for WxWidgets, as WxWidgets has no support for
693	watching file handles. However, you can use WxWidgets through the
694	POE Adaptor, as POE has a Wx backend that simply polls 20 times per
695	second, which was considered to be too horrible to even consider for
696	AnyEvent. Likewise, other POE backends can be used by AnyEvent by using
697	it's adaptor.
698
699	AnyEvent knows about L<Prima> and L<Wx> and will try to use L<POE> when
700	autodetecting them.
701		825
702	=item AnyEvent::detect	826	=item AnyEvent::detect
703		827
704	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model	828	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model
705	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
706	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
707	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>.
708		835
709	=item $guard = AnyEvent::post_detect { BLOCK }	836	=item $guard = AnyEvent::post_detect { BLOCK }
710		837
711	Arranges for the code block to be executed as soon as the event model is	838	Arranges for the code block to be executed as soon as the event model is
712	autodetected (or immediately if this has already happened).	839	autodetected (or immediately if this has already happened).
		840
		841	The block will be executed I<after> the actual backend has been detected
		842	(C<$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.
713		851
714	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
715	that automatically removes the callback again when it is destroyed. See	853	that automatically removes the callback again when it is destroyed. See
716	L<Coro::BDB> for a case where this is useful.	854	L<Coro::BDB> for a case where this is useful.
717		855
…		…
720	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
721	before or after loading AnyEvent), then they will called directly after	859	before or after loading AnyEvent), then they will called directly after
722	the event loop has been chosen.	860	the event loop has been chosen.
723		861
724	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:
725	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
726	and the array will be ignored.	864	array will be ignored.
727		865
728	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.
729		873
730	=back	874	=back
731		875
732	=head1 WHAT TO DO IN A MODULE	876	=head1 WHAT TO DO IN A MODULE
733		877
…		…
788		932
789		933
790	=head1 OTHER MODULES	934	=head1 OTHER MODULES
791		935
792	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
793	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
794	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
795	available via CPAN.	939	come with AnyEvent, most are available via CPAN.
796		940
797	=over 4	941	=over 4
798		942
799	=item L<AnyEvent::Util>	943	=item L<AnyEvent::Util>
800		944
…		…
809		953
810	=item L<AnyEvent::Handle>	954	=item L<AnyEvent::Handle>
811		955
812	Provide read and write buffers, manages watchers for reads and writes,	956	Provide read and write buffers, manages watchers for reads and writes,
813	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
814	non-blocking SSL/TLS.	958	non-blocking SSL/TLS (via L<AnyEvent::TLS>.
815		959
816	=item L<AnyEvent::DNS>	960	=item L<AnyEvent::DNS>
817		961
818	Provides rich asynchronous DNS resolver capabilities.	962	Provides rich asynchronous DNS resolver capabilities.
819		963
…		…
847		991
848	=item L<AnyEvent::GPSD>	992	=item L<AnyEvent::GPSD>
849		993
850	A non-blocking interface to gpsd, a daemon delivering GPS information.	994	A non-blocking interface to gpsd, a daemon delivering GPS information.
851		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
852	=item L<AnyEvent::IGS>	1005	=item L<AnyEvent::IGS>
853		1006
854	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
855	L<App::IGS>).	1008	L<App::IGS>).
856		1009
857	=item L<AnyEvent::IRC>
858
859	AnyEvent based IRC client module family (replacing the older Net::IRC3).
860
861	=item L<Net::XMPP2>
862
863	AnyEvent based XMPP (Jabber protocol) module family.
864
865	=item L<Net::FCP>	1010	=item L<Net::FCP>
866		1011
867	AnyEvent-based implementation of the Freenet Client Protocol, birthplace	1012	AnyEvent-based implementation of the Freenet Client Protocol, birthplace
868	of AnyEvent.	1013	of AnyEvent.
869		1014
…		…
873		1018
874	=item L<Coro>	1019	=item L<Coro>
875		1020
876	Has special support for AnyEvent via L<Coro::AnyEvent>.	1021	Has special support for AnyEvent via L<Coro::AnyEvent>.
877		1022
878	=item L<IO::Lambda>
879
880	The lambda approach to I/O - don't ask, look there. Can use AnyEvent.
881
882	=back	1023	=back
883		1024
884	=cut	1025	=cut
885		1026
886	package AnyEvent;	1027	package AnyEvent;
887		1028
888	no warnings;	1029	no warnings;
889	use strict qw(vars subs);	1030	use strict qw(vars subs);
890		1031
891	use Carp;	1032	use Carp ();
892		1033
893	our $VERSION = 4.352;	1034	our $VERSION = 4.83;
894	our $MODEL;	1035	our $MODEL;
895		1036
896	our $AUTOLOAD;	1037	our $AUTOLOAD;
897	our @ISA;	1038	our @ISA;
898		1039
899	our @REGISTRY;	1040	our @REGISTRY;
900		1041
901	our $WIN32;	1042	our $WIN32;
902		1043
903	BEGIN {	1044	BEGIN {
904	my $win32 = ! ! ($^O =~ /mswin32/i);	1045	eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }";
905	eval "sub WIN32(){ $win32 }";	1046	eval "sub TAINT(){ " . (${^TAINT}*1) . " }";
		1047
		1048	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}
		1049	if ${^TAINT};
906	}	1050	}
907		1051
908	our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1;	1052	our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1;
909		1053
910	our %PROTOCOL; # (ipv4\|ipv6) => (1\|2), higher numbers are preferred	1054	our %PROTOCOL; # (ipv4\|ipv6) => (1\|2), higher numbers are preferred
…		…
921	[Event:: => AnyEvent::Impl::Event::],	1065	[Event:: => AnyEvent::Impl::Event::],
922	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::],	1066	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::],
923	# everything below here will not be autoprobed	1067	# everything below here will not be autoprobed
924	# as the pureperl backend should work everywhere	1068	# as the pureperl backend should work everywhere
925	# and is usually faster	1069	# and is usually faster
926	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
927	[Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers	1070	[Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers
928	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy	1071	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
		1072	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
929	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program	1073	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program
930	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza	1074	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
931	[Wx:: => AnyEvent::Impl::POE::],	1075	[Wx:: => AnyEvent::Impl::POE::],
932	[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
933	);	1084	);
934		1085
935	our %method = map +($_ => 1),	1086	our %method = map +($_ => 1),
936	qw(io timer time now now_update signal child condvar one_event DESTROY);	1087	qw(io timer time now now_update signal child idle condvar one_event DESTROY);
937		1088
938	our @post_detect;	1089	our @post_detect;
939		1090
940	sub post_detect(&) {	1091	sub post_detect(&) {
941	my ($cb) = @_;	1092	my ($cb) = @_;
…		…
946	1	1097	1
947	} else {	1098	} else {
948	push @post_detect, $cb;	1099	push @post_detect, $cb;
949		1100
950	defined wantarray	1101	defined wantarray
951	? bless \$cb, "AnyEvent::Util::PostDetect"	1102	? bless \$cb, "AnyEvent::Util::postdetect"
952	: ()	1103	: ()
953	}	1104	}
954	}	1105	}
955		1106
956	sub AnyEvent::Util::PostDetect::DESTROY {	1107	sub AnyEvent::Util::postdetect::DESTROY {
957	@post_detect = grep $_ != ${$_[0]}, @post_detect;	1108	@post_detect = grep $_ != ${$_[0]}, @post_detect;
958	}	1109	}
959		1110
960	sub detect() {	1111	sub detect() {
961	unless ($MODEL) {	1112	unless ($MODEL) {
…		…
964		1115
965	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {	1116	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {
966	my $model = "AnyEvent::Impl::$1";	1117	my $model = "AnyEvent::Impl::$1";
967	if (eval "require $model") {	1118	if (eval "require $model") {
968	$MODEL = $model;	1119	$MODEL = $model;
969	warn "AnyEvent: loaded model '$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 $verbose > 1;
970	} else {	1121	} else {
971	warn "AnyEvent: unable to load model '$model' (from \$PERL_ANYEVENT_MODEL):\n$@" if $verbose;	1122	warn "AnyEvent: unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@" if $verbose;
972	}	1123	}
973	}	1124	}
974		1125
975	# check for already loaded models	1126	# check for already loaded models
976	unless ($MODEL) {	1127	unless ($MODEL) {
…		…
1018		1169
1019	sub AUTOLOAD {	1170	sub AUTOLOAD {
1020	(my $func = $AUTOLOAD) =~ s/.*://;	1171	(my $func = $AUTOLOAD) =~ s/.*://;
1021		1172
1022	$method{$func}	1173	$method{$func}
1023	or croak "$func: not a valid method for AnyEvent objects";	1174	or Carp::croak "$func: not a valid method for AnyEvent objects";
1024		1175
1025	detect unless $MODEL;	1176	detect unless $MODEL;
1026		1177
1027	my $class = shift;	1178	my $class = shift;
1028	$class->$func (@_);	1179	$class->$func (@_);
1029	}	1180	}
1030		1181
1031	# 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
1032	# to support binding more than one watcher per filehandle (they usually	1183	# to support binding more than one watcher per filehandle (they usually
1033	# 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).
1034	sub _dupfh($$$$) {	1185	sub _dupfh($$;$$) {
1035	my ($poll, $fh, $r, $w) = @_;	1186	my ($poll, $fh, $r, $w) = @_;
1036		1187
1037	# cygwin requires the fh mode to be matching, unix doesn't	1188	# cygwin requires the fh mode to be matching, unix doesn't
1038	my ($rw, $mode) = $poll eq "r" ? ($r, "<")	1189	my ($rw, $mode) = $poll eq "r" ? ($r, "<&") : ($w, ">&");
1039	: $poll eq "w" ? ($w, ">")
1040	: Carp::croak "AnyEvent->io requires poll set to either 'r' or 'w'";
1041		1190
1042	open my $fh2, "$mode&" . fileno $fh	1191	open my $fh2, $mode, $fh
1043	or die "cannot dup() filehandle: $!,";	1192	or die "AnyEvent->io: cannot dup() filehandle in mode '$poll': $!,";
1044		1193
1045	# 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
1046		1195
1047	($fh2, $rw)	1196	($fh2, $rw)
1048	}	1197	}
…		…
1050	package AnyEvent::Base;	1199	package AnyEvent::Base;
1051		1200
1052	# default implementations for many methods	1201	# default implementations for many methods
1053		1202
1054	BEGIN {	1203	BEGIN {
1055	if (eval "use Time::HiRes (); time (); 1") {	1204	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {
1056	*_time = \&Time::HiRes::time;	1205	*_time = \&Time::HiRes::time;
1057	# if (eval "use POSIX (); (POSIX::times())...	1206	# if (eval "use POSIX (); (POSIX::times())...
1058	} else {	1207	} else {
1059	*_time = sub { time }; # epic fail	1208	*_time = sub { time }; # epic fail
1060	}	1209	}
…		…
1065	sub now_update { }	1214	sub now_update { }
1066		1215
1067	# default implementation for ->condvar	1216	# default implementation for ->condvar
1068		1217
1069	sub condvar {	1218	sub condvar {
1070	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, AnyEvent::CondVar::	1219	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"
1071	}	1220	}
1072		1221
1073	# default implementation for ->signal	1222	# default implementation for ->signal
1074		1223
1075	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);	1224	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);
…		…
1099	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W) if $SIGPIPE_W; # just in case	1248	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W) if $SIGPIPE_W; # just in case
1100	} else {	1249	} else {
1101	pipe $SIGPIPE_R, $SIGPIPE_W;	1250	pipe $SIGPIPE_R, $SIGPIPE_W;
1102	fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R;	1251	fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R;
1103	fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case	1252	fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case
		1253
		1254	# not strictly required, as $^F is normally 2, but let's make sure...
		1255	fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
		1256	fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
1104	}	1257	}
1105		1258
1106	$SIGPIPE_R	1259	$SIGPIPE_R
1107	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";	1260	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";
1108
1109	# not strictly required, as $^F is normally 2, but let's make sure...
1110	fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
1111	fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
1112		1261
1113	$SIG_IO = AnyEvent->io (fh => $SIGPIPE_R, poll => "r", cb => \&_signal_exec);	1262	$SIG_IO = AnyEvent->io (fh => $SIGPIPE_R, poll => "r", cb => \&_signal_exec);
1114	}	1263	}
1115		1264
1116	my $signal = uc $arg{signal}	1265	my $signal = uc $arg{signal}
…		…
1121	local $!;	1270	local $!;
1122	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;	1271	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;
1123	undef $SIG_EV{$signal};	1272	undef $SIG_EV{$signal};
1124	};	1273	};
1125		1274
1126	bless [$signal, $arg{cb}], "AnyEvent::Base::Signal"	1275	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
1127	}	1276	}
1128		1277
1129	sub AnyEvent::Base::Signal::DESTROY {	1278	sub AnyEvent::Base::signal::DESTROY {
1130	my ($signal, $cb) = @{$_[0]};	1279	my ($signal, $cb) = @{$_[0]};
1131		1280
1132	delete $SIG_CB{$signal}{$cb};	1281	delete $SIG_CB{$signal}{$cb};
1133		1282
		1283	# delete doesn't work with older perls - they then
		1284	# print weird messages, or just unconditionally exit
		1285	# instead of getting the default action.
1134	delete $SIG{$signal} unless keys %{ $SIG_CB{$signal} };	1286	undef $SIG{$signal} unless keys %{ $SIG_CB{$signal} };
1135	}	1287	}
1136		1288
1137	# default implementation for ->child	1289	# default implementation for ->child
1138		1290
1139	our %PID_CB;	1291	our %PID_CB;
1140	our $CHLD_W;	1292	our $CHLD_W;
1141	our $CHLD_DELAY_W;	1293	our $CHLD_DELAY_W;
1142	our $PID_IDLE;
1143	our $WNOHANG;	1294	our $WNOHANG;
1144		1295
1145	sub _child_wait {	1296	sub _sigchld {
1146	while (0 < (my $pid = waitpid -1, $WNOHANG)) {	1297	while (0 < (my $pid = waitpid -1, $WNOHANG)) {
1147	$_->($pid, $?) for (values %{ $PID_CB{$pid} \|\| {} }),	1298	$_->($pid, $?) for (values %{ $PID_CB{$pid} \|\| {} }),
1148	(values %{ $PID_CB{0} \|\| {} });	1299	(values %{ $PID_CB{0} \|\| {} });
1149	}	1300	}
1150
1151	undef $PID_IDLE;
1152	}
1153
1154	sub _sigchld {
1155	# make sure we deliver these changes "synchronous" with the event loop.
1156	$CHLD_DELAY_W \|\|= AnyEvent->timer (after => 0, cb => sub {
1157	undef $CHLD_DELAY_W;
1158	&_child_wait;
1159	});
1160	}	1301	}
1161		1302
1162	sub child {	1303	sub child {
1163	my (undef, %arg) = @_;	1304	my (undef, %arg) = @_;
1164		1305
1165	defined (my $pid = $arg{pid} + 0)	1306	defined (my $pid = $arg{pid} + 0)
1166	or Carp::croak "required option 'pid' is missing";	1307	or Carp::croak "required option 'pid' is missing";
1167		1308
1168	$PID_CB{$pid}{$arg{cb}} = $arg{cb};	1309	$PID_CB{$pid}{$arg{cb}} = $arg{cb};
1169		1310
1170	unless ($WNOHANG) {
1171	$WNOHANG = eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } \|\| 1;	1311	$WNOHANG \|\|= eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } \|\| 1;
1172	}
1173		1312
1174	unless ($CHLD_W) {	1313	unless ($CHLD_W) {
1175	$CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld);	1314	$CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld);
1176	# child could be a zombie already, so make at least one round	1315	# child could be a zombie already, so make at least one round
1177	&_sigchld;	1316	&_sigchld;
1178	}	1317	}
1179		1318
1180	bless [$pid, $arg{cb}], "AnyEvent::Base::Child"	1319	bless [$pid, $arg{cb}], "AnyEvent::Base::child"
1181	}	1320	}
1182		1321
1183	sub AnyEvent::Base::Child::DESTROY {	1322	sub AnyEvent::Base::child::DESTROY {
1184	my ($pid, $cb) = @{$_[0]};	1323	my ($pid, $cb) = @{$_[0]};
1185		1324
1186	delete $PID_CB{$pid}{$cb};	1325	delete $PID_CB{$pid}{$cb};
1187	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };	1326	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };
1188		1327
1189	undef $CHLD_W unless keys %PID_CB;	1328	undef $CHLD_W unless keys %PID_CB;
		1329	}
		1330
		1331	# idle emulation is done by simply using a timer, regardless
		1332	# of whether the process is idle or not, and not letting
		1333	# the callback use more than 50% of the time.
		1334	sub idle {
		1335	my (undef, %arg) = @_;
		1336
		1337	my ($cb, $w, $rcb) = $arg{cb};
		1338
		1339	$rcb = sub {
		1340	if ($cb) {
		1341	$w = _time;
		1342	&$cb;
		1343	$w = _time - $w;
		1344
		1345	# never use more then 50% of the time for the idle watcher,
		1346	# within some limits
		1347	$w = 0.0001 if $w < 0.0001;
		1348	$w = 5 if $w > 5;
		1349
		1350	$w = AnyEvent->timer (after => $w, cb => $rcb);
		1351	} else {
		1352	# clean up...
		1353	undef $w;
		1354	undef $rcb;
		1355	}
		1356	};
		1357
		1358	$w = AnyEvent->timer (after => 0.05, cb => $rcb);
		1359
		1360	bless \\$cb, "AnyEvent::Base::idle"
		1361	}
		1362
		1363	sub AnyEvent::Base::idle::DESTROY {
		1364	undef $${$_[0]};
1190	}	1365	}
1191		1366
1192	package AnyEvent::CondVar;	1367	package AnyEvent::CondVar;
1193		1368
1194	our @ISA = AnyEvent::CondVar::Base::;	1369	our @ISA = AnyEvent::CondVar::Base::;
…		…
1196	package AnyEvent::CondVar::Base;	1371	package AnyEvent::CondVar::Base;
1197		1372
1198	use overload	1373	use overload
1199	'&{}' => sub { my $self = shift; sub { $self->send (@_) } },	1374	'&{}' => sub { my $self = shift; sub { $self->send (@_) } },
1200	fallback => 1;	1375	fallback => 1;
		1376
		1377	our $WAITING;
1201		1378
1202	sub _send {	1379	sub _send {
1203	# nop	1380	# nop
1204	}	1381	}
1205		1382
…		…
1218	sub ready {	1395	sub ready {
1219	$_[0]{_ae_sent}	1396	$_[0]{_ae_sent}
1220	}	1397	}
1221		1398
1222	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 $WAITING = 1;
1223	AnyEvent->one_event while !$_[0]{_ae_sent};	1405	AnyEvent->one_event while !$_[0]{_ae_sent};
1224	}	1406	}
1225		1407
1226	sub recv {	1408	sub recv {
1227	$_[0]->_wait;	1409	$_[0]->_wait;
…		…
1268	so on.	1450	so on.
1269		1451
1270	=head1 ENVIRONMENT VARIABLES	1452	=head1 ENVIRONMENT VARIABLES
1271		1453
1272	The following environment variables are used by this module or its	1454	The following environment variables are used by this module or its
1273	submodules:	1455	submodules.
		1456
		1457	Note that AnyEvent will remove I<all> environment variables starting with
		1458	C<PERL_ANYEVENT_> from C<%ENV> when it is loaded while taint mode is
		1459	enabled.
1274		1460
1275	=over 4	1461	=over 4
1276		1462
1277	=item C<PERL_ANYEVENT_VERBOSE>	1463	=item C<PERL_ANYEVENT_VERBOSE>
1278		1464
…		…
1290	=item C<PERL_ANYEVENT_STRICT>	1476	=item C<PERL_ANYEVENT_STRICT>
1291		1477
1292	AnyEvent does not do much argument checking by default, as thorough	1478	AnyEvent does not do much argument checking by default, as thorough
1293	argument checking is very costly. Setting this variable to a true value	1479	argument checking is very costly. Setting this variable to a true value
1294	will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly	1480	will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly
1295	check the arguments passed to most method calls. If it finds any problems	1481	check the arguments passed to most method calls. If it finds any problems,
1296	it will croak.	1482	it will croak.
1297		1483
1298	In other words, enables "strict" mode.	1484	In other words, enables "strict" mode.
1299		1485
1300	Unlike C<use strict>, it is definitely recommended ot keep it off in	1486	Unlike C<use strict>, it is definitely recommended to keep it off in
1301	production. Keeping C<PERL_ANYEVENT_STRICT=1> in your environment while	1487	production. Keeping C<PERL_ANYEVENT_STRICT=1> in your environment while
1302	developing programs can be very useful, however.	1488	developing programs can be very useful, however.
1303		1489
1304	=item C<PERL_ANYEVENT_MODEL>	1490	=item C<PERL_ANYEVENT_MODEL>
1305		1491
…		…
1350		1536
1351	=item C<PERL_ANYEVENT_MAX_FORKS>	1537	=item C<PERL_ANYEVENT_MAX_FORKS>
1352		1538
1353	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>
1354	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.
1355		1560
1356	=back	1561	=back
1357		1562
1358	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE	1563	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE
1359		1564
…		…
1604	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
1605	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
1606	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
1607	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
1608	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
1609	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
1610	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
1611	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
1612	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
1613		1820
…		…
1642	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
1643	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.
1644		1851
1645	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
1646	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.
1647		1857
1648	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
1649	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
1650	C<Event>. However, Glib scales extremely badly, doubling the number of	1860	C<Event>. However, Glib scales extremely badly, doubling the number of
1651	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,
…		…
1729	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
1730	a new one that moves the timeout into the future.	1940	a new one that moves the timeout into the future.
1731		1941
1732	=head3 Results	1942	=head3 Results
1733		1943
1734	name sockets create request	1944	name sockets create request
1735	EV 20000 69.01 11.16	1945	EV 20000 69.01 11.16
1736	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
1737	Event 20000 212.62 257.32	1949	Event 20000 212.62 257.32
1738	Glib 20000 651.16 1896.30	1950	Glib 20000 651.16 1896.30
1739	POE 20000 349.67 12317.24 uses POE::Loop::Event	1951	POE 20000 349.67 12317.24 uses POE::Loop::Event
1740		1952
1741	=head3 Discussion	1953	=head3 Discussion
1742		1954
1743	This benchmark I<does> measure scalability and overall performance of the	1955	This benchmark I<does> measure scalability and overall performance of the
1744	particular event loop.	1956	particular event loop.
…		…
1746	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
1747	is relatively high, though.	1959	is relatively high, though.
1748		1960
1749	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
1750	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.
1751		1966
1752	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
1753	understand why). Callback invocation also has a high overhead compared to	1968	understand why). Callback invocation also has a high overhead compared to
1754	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
1755	uses select or poll in basically all documented configurations.	1970	uses select or poll in basically all documented configurations.
…		…
1818	=item * C-based event loops perform very well with small number of	2033	=item * C-based event loops perform very well with small number of
1819	watchers, as the management overhead dominates.	2034	watchers, as the management overhead dominates.
1820		2035
1821	=back	2036	=back
1822		2037
		2038	=head2 THE IO::Lambda BENCHMARK
		2039
		2040	Recently I was told about the benchmark in the IO::Lambda manpage, which
		2041	could be misinterpreted to make AnyEvent look bad. In fact, the benchmark
		2042	simply compares IO::Lambda with POE, and IO::Lambda looks better (which
		2043	shouldn't come as a surprise to anybody). As such, the benchmark is
		2044	fine, and mostly shows that the AnyEvent backend from IO::Lambda isn't
		2045	very optimal. But how would AnyEvent compare when used without the extra
		2046	baggage? To explore this, I wrote the equivalent benchmark for AnyEvent.
		2047
		2048	The benchmark itself creates an echo-server, and then, for 500 times,
		2049	connects to the echo server, sends a line, waits for the reply, and then
		2050	creates the next connection. This is a rather bad benchmark, as it doesn't
		2051	test the efficiency of the framework or much non-blocking I/O, but it is a
		2052	benchmark nevertheless.
		2053
		2054	name runtime
		2055	Lambda/select 0.330 sec
		2056	+ optimized 0.122 sec
		2057	Lambda/AnyEvent 0.327 sec
		2058	+ optimized 0.138 sec
		2059	Raw sockets/select 0.077 sec
		2060	POE/select, components 0.662 sec
		2061	POE/select, raw sockets 0.226 sec
		2062	POE/select, optimized 0.404 sec
		2063
		2064	AnyEvent/select/nb 0.085 sec
		2065	AnyEvent/EV/nb 0.068 sec
		2066	+state machine 0.134 sec
		2067
		2068	The benchmark is also a bit unfair (my fault): the IO::Lambda/POE
		2069	benchmarks actually make blocking connects and use 100% blocking I/O,
		2070	defeating the purpose of an event-based solution. All of the newly
		2071	written AnyEvent benchmarks use 100% non-blocking connects (using
		2072	AnyEvent::Socket::tcp_connect and the asynchronous pure perl DNS
		2073	resolver), so AnyEvent is at a disadvantage here, as non-blocking connects
		2074	generally require a lot more bookkeeping and event handling than blocking
		2075	connects (which involve a single syscall only).
		2076
		2077	The last AnyEvent benchmark additionally uses L<AnyEvent::Handle>, which
		2078	offers similar expressive power as POE and IO::Lambda, using conventional
		2079	Perl syntax. This means that both the echo server and the client are 100%
		2080	non-blocking, further placing it at a disadvantage.
		2081
		2082	As you can see, the AnyEvent + EV combination even beats the
		2083	hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl
		2084	backend easily beats IO::Lambda and POE.
		2085
		2086	And even the 100% non-blocking version written using the high-level (and
		2087	slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda by a
		2088	large margin, even though it does all of DNS, tcp-connect and socket I/O
		2089	in a non-blocking way.
		2090
		2091	The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and
		2092	F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are
		2093	part of the IO::lambda distribution and were used without any changes.
		2094
1823		2095
1824	=head1 SIGNALS	2096	=head1 SIGNALS
1825		2097
1826	AnyEvent currently installs handlers for these signals:	2098	AnyEvent currently installs handlers for these signals:
1827		2099
…		…
1830	=item SIGCHLD	2102	=item SIGCHLD
1831		2103
1832	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
1833	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
1834	event loops install a similar handler.	2106	event loops install a similar handler.
		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.
1835		2110
1836	=item SIGPIPE	2111	=item SIGPIPE
1837		2112
1838	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>
1839	when AnyEvent gets loaded.	2114	when AnyEvent gets loaded.
…		…
1851		2126
1852	=back	2127	=back
1853		2128
1854	=cut	2129	=cut
1855		2130
		2131	undef $SIG{CHLD}
		2132	if $SIG{CHLD} eq 'IGNORE';
		2133
1856	$SIG{PIPE} = sub { }	2134	$SIG{PIPE} = sub { }
1857	unless defined $SIG{PIPE};	2135	unless defined $SIG{PIPE};
1858
1859		2136
1860	=head1 FORK	2137	=head1 FORK
1861		2138
1862	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
1863	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>
…		…
1884	use AnyEvent;	2161	use AnyEvent;
1885		2162
1886	Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can	2163	Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can
1887	be used to probe what backend is used and gain other information (which is	2164	be used to probe what backend is used and gain other information (which is
1888	probably even less useful to an attacker than PERL_ANYEVENT_MODEL), and	2165	probably even less useful to an attacker than PERL_ANYEVENT_MODEL), and
1889	$ENV{PERL_ANYEGENT_STRICT}.	2166	$ENV{PERL_ANYEVENT_STRICT}.
		2167
		2168	Note that AnyEvent will remove I<all> environment variables starting with
		2169	C<PERL_ANYEVENT_> from C<%ENV> when it is loaded while taint mode is
		2170	enabled.
1890		2171
1891		2172
1892	=head1 BUGS	2173	=head1 BUGS
1893		2174
1894	Perl 5.8 has numerous memleaks that sometimes hit this module and are hard	2175	Perl 5.8 has numerous memleaks that sometimes hit this module and are hard
…		…
1906	L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.	2187	L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.
1907		2188
1908	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,	2189	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,
1909	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>,
1910	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,	2191	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,
1911	L<AnyEvent::Impl::POE>.	2192	L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>.
1912		2193
1913	Non-blocking file handles, sockets, TCP clients and	2194	Non-blocking file handles, sockets, TCP clients and
1914	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>.	2195	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.
1915		2196
1916	Asynchronous DNS: L<AnyEvent::DNS>.	2197	Asynchronous DNS: L<AnyEvent::DNS>.
1917		2198
1918	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>,
1919		2201
1920	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>.
1921		2204
1922		2205
1923	=head1 AUTHOR	2206	=head1 AUTHOR
1924		2207
1925	Marc Lehmann <schmorp@schmorp.de>	2208	Marc Lehmann <schmorp@schmorp.de>

Diff Legend

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

Comparing AnyEvent/lib/AnyEvent.pm (file contents): Revision 1.206 by root, Mon Apr 20 14:34:18 2009 UTC vs. Revision 1.241 by root, Fri Jul 17 18:08:35 2009 UTC

Diff Legend

Comparing AnyEvent/lib/AnyEvent.pm (file contents):
Revision 1.206 by root, Mon Apr 20 14:34:18 2009 UTC vs.
Revision 1.241 by root, Fri Jul 17 18:08:35 2009 UTC