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

Comparing AnyEvent/lib/AnyEvent.pm (file contents):
Revision 1.216 by root, Tue Jun 23 12:21:34 2009 UTC vs.
Revision 1.253 by root, Tue Jul 21 06:00:47 2009 UTC

…		…
1	=head1 NAME	1	=head1 NAME
2		2
3	AnyEvent - provide framework for multiple event loops	3	AnyEvent - events independent of event loop implementation
4		4
5	EV, Event, Glib, Tk, Perl, Event::Lib, Qt and POE are various supported	5	EV, Event, Glib, Tk, Perl, Event::Lib, Qt and POE are various supported
6	event loops.	6	event loops.
7		7
8	=head1 SYNOPSIS	8	=head1 SYNOPSIS
40	=head1 INTRODUCTION/TUTORIAL	40	=head1 INTRODUCTION/TUTORIAL
41		41
42	This manpage is mainly a reference manual. If you are interested	42	This manpage is mainly a reference manual. If you are interested
43	in a tutorial or some gentle introduction, have a look at the	43	in a tutorial or some gentle introduction, have a look at the
44	L<AnyEvent::Intro> manpage.	44	L<AnyEvent::Intro> manpage.
		45
		46	=head1 SUPPORT
		47
		48	There is a mailinglist for discussing all things AnyEvent, and an IRC
		49	channel, too.
		50
		51	See the AnyEvent project page at the B<Schmorpforge Ta-Sa Software
		52	Respository>, at L<http://anyevent.schmorp.de>, for more info.
45		53
46	=head1 WHY YOU SHOULD USE THIS MODULE (OR NOT)	54	=head1 WHY YOU SHOULD USE THIS MODULE (OR NOT)
47		55
48	Glib, POE, IO::Async, Event... CPAN offers event models by the dozen	56	Glib, POE, IO::Async, Event... CPAN offers event models by the dozen
49	nowadays. So what is different about AnyEvent?	57	nowadays. So what is different about AnyEvent?
…		…
176	=head2 I/O WATCHERS	184	=head2 I/O WATCHERS
177		185
178	You can create an I/O watcher by calling the C<< AnyEvent->io >> method	186	You can create an I/O watcher by calling the C<< AnyEvent->io >> method
179	with the following mandatory key-value pairs as arguments:	187	with the following mandatory key-value pairs as arguments:
180		188
181	C<fh> is the Perl I<file handle> (I<not> file descriptor) to watch	189	C<fh> is the Perl I<file handle> (or a naked file descriptor) to watch
182	for events (AnyEvent might or might not keep a reference to this file	190	for events (AnyEvent might or might not keep a reference to this file
183	handle). Note that only file handles pointing to things for which	191	handle). Note that only file handles pointing to things for which
184	non-blocking operation makes sense are allowed. This includes sockets,	192	non-blocking operation makes sense are allowed. This includes sockets,
185	most character devices, pipes, fifos and so on, but not for example files	193	most character devices, pipes, fifos and so on, but not for example files
186	or block devices.	194	or block devices.
…		…
361	invocation, and callback invocation will be synchronous. Synchronous means	369	invocation, and callback invocation will be synchronous. Synchronous means
362	that it might take a while until the signal gets handled by the process,	370	that it might take a while until the signal gets handled by the process,
363	but it is guaranteed not to interrupt any other callbacks.	371	but it is guaranteed not to interrupt any other callbacks.
364		372
365	The main advantage of using these watchers is that you can share a signal	373	The main advantage of using these watchers is that you can share a signal
366	between multiple watchers.	374	between multiple watchers, and AnyEvent will ensure that signals will not
		375	interrupt your program at bad times.
367		376
368	This watcher might use C<%SIG>, so programs overwriting those signals	377	This watcher might use C<%SIG> (depending on the event loop used),
369	directly will likely not work correctly.	378	so programs overwriting those signals directly will likely not work
		379	correctly.
370		380
371	Example: exit on SIGINT	381	Example: exit on SIGINT
372		382
373	my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });	383	my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });
		384
		385	=head3 Signal Races, Delays and Workarounds
		386
		387	Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support attaching
		388	callbacks to signals in a generic way, which is a pity, as you cannot do
		389	race-free signal handling in perl. AnyEvent will try to do it's best, but
		390	in some cases, signals will be delayed. The maximum time a signal might
		391	be delayed is specified in C<$AnyEvent::MAX_SIGNAL_LATENCY> (default: 10
		392	seconds). This variable can be changed only before the first signal
		393	watcher is created, and should be left alone otherwise. Higher values
		394	will cause fewer spurious wake-ups, which is better for power and CPU
		395	saving. All these problems can be avoided by installing the optional
		396	L<Async::Interrupt> module. This will not work with inherently broken
		397	event loops such as L<Event> or L<Event::Lib> (and not with L<POE>
		398	currently, as POE does it's own workaround with one-second latency). With
		399	those, you just have to suffer the delays.
374		400
375	=head2 CHILD PROCESS WATCHERS	401	=head2 CHILD PROCESS WATCHERS
376		402
377	You can also watch on a child process exit and catch its exit status.	403	You can also watch on a child process exit and catch its exit status.
378		404
…		…
392		418
393	There is a slight catch to child watchers, however: you usually start them	419	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	420	I<after> the child process was created, and this means the process could
395	have exited already (and no SIGCHLD will be sent anymore).	421	have exited already (and no SIGCHLD will be sent anymore).
396		422
397	Not all event models handle this correctly (POE doesn't), but even for	423	Not all event models handle this correctly (neither POE nor IO::Async do,
		424	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	425	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).	426	the process exits (i.e. before you fork in the first place). AnyEvent's
		427	pure perl event loop handles all cases correctly regardless of when you
		428	start the watcher.
400		429
401	This means you cannot create a child watcher as the very first thing in an	430	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	431	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>).	432	watcher before you C<fork> the child (alternatively, you can call
		433	C<AnyEvent::detect>).
		434
		435	As most event loops do not support waiting for child events, they will be
		436	emulated by AnyEvent in most cases, in which the latency and race problems
		437	mentioned in the description of signal watchers apply.
404		438
405	Example: fork a process and wait for it	439	Example: fork a process and wait for it
406		440
407	my $done = AnyEvent->condvar;	441	my $done = AnyEvent->condvar;
408		442
…		…
459		493
460	If you are familiar with some event loops you will know that all of them	494	If you are familiar with some event loops you will know that all of them
461	require you to run some blocking "loop", "run" or similar function that	495	require you to run some blocking "loop", "run" or similar function that
462	will actively watch for new events and call your callbacks.	496	will actively watch for new events and call your callbacks.
463		497
464	AnyEvent is different, it expects somebody else to run the event loop and	498	AnyEvent is slightly different: it expects somebody else to run the event
465	will only block when necessary (usually when told by the user).	499	loop and will only block when necessary (usually when told by the user).
466		500
467	The instrument to do that is called a "condition variable", so called	501	The instrument to do that is called a "condition variable", so called
468	because they represent a condition that must become true.	502	because they represent a condition that must become true.
469		503
		504	Now is probably a good time to look at the examples further below.
		505
470	Condition variables can be created by calling the C<< AnyEvent->condvar	506	Condition variables can be created by calling the C<< AnyEvent->condvar
471	>> method, usually without arguments. The only argument pair allowed is	507	>> 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	508	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	509	becomes true, with the condition variable as the first argument (but not
475	the results).	510	the results).
476		511
477	After creation, the condition variable is "false" until it becomes "true"	512	After creation, the condition variable is "false" until it becomes "true"
…		…
482	Condition variables are similar to callbacks, except that you can	517	Condition variables are similar to callbacks, except that you can
483	optionally wait for them. They can also be called merge points - points	518	optionally wait for them. They can also be called merge points - points
484	in time where multiple outstanding events have been processed. And yet	519	in time where multiple outstanding events have been processed. And yet
485	another way to call them is transactions - each condition variable can be	520	another way to call them is transactions - each condition variable can be
486	used to represent a transaction, which finishes at some point and delivers	521	used to represent a transaction, which finishes at some point and delivers
487	a result.	522	a result. And yet some people know them as "futures" - a promise to
		523	compute/deliver something that you can wait for.
488		524
489	Condition variables are very useful to signal that something has finished,	525	Condition variables are very useful to signal that something has finished,
490	for example, if you write a module that does asynchronous http requests,	526	for example, if you write a module that does asynchronous http requests,
491	then a condition variable would be the ideal candidate to signal the	527	then a condition variable would be the ideal candidate to signal the
492	availability of results. The user can either act when the callback is	528	availability of results. The user can either act when the callback is
…		…
526	after => 1,	562	after => 1,
527	cb => sub { $result_ready->send },	563	cb => sub { $result_ready->send },
528	);	564	);
529		565
530	# this "blocks" (while handling events) till the callback	566	# this "blocks" (while handling events) till the callback
531	# calls send	567	# calls -<send
532	$result_ready->recv;	568	$result_ready->recv;
533		569
534	Example: wait for a timer, but take advantage of the fact that	570	Example: wait for a timer, but take advantage of the fact that condition
535	condition variables are also code references.	571	variables are also callable directly.
536		572
537	my $done = AnyEvent->condvar;	573	my $done = AnyEvent->condvar;
538	my $delay = AnyEvent->timer (after => 5, cb => $done);	574	my $delay = AnyEvent->timer (after => 5, cb => $done);
539	$done->recv;	575	$done->recv;
540		576
…		…
546		582
547	...	583	...
548		584
549	my @info = $couchdb->info->recv;	585	my @info = $couchdb->info->recv;
550		586
551	And this is how you would just ste a callback to be called whenever the	587	And this is how you would just set a callback to be called whenever the
552	results are available:	588	results are available:
553		589
554	$couchdb->info->cb (sub {	590	$couchdb->info->cb (sub {
555	my @info = $_[0]->recv;	591	my @info = $_[0]->recv;
556	});	592	});
…		…
574	immediately from within send.	610	immediately from within send.
575		611
576	Any arguments passed to the C<send> call will be returned by all	612	Any arguments passed to the C<send> call will be returned by all
577	future C<< ->recv >> calls.	613	future C<< ->recv >> calls.
578		614
579	Condition variables are overloaded so one can call them directly	615	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	616	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	617	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		618
588	=item $cv->croak ($error)	619	=item $cv->croak ($error)
589		620
590	Similar to send, but causes all call's to C<< ->recv >> to invoke	621	Similar to send, but causes all call's to C<< ->recv >> to invoke
591	C<Carp::croak> with the given error message/object/scalar.	622	C<Carp::croak> with the given error message/object/scalar.
592		623
593	This can be used to signal any errors to the condition variable	624	This can be used to signal any errors to the condition variable
594	user/consumer.	625	user/consumer. Doing it this way instead of calling C<croak> directly
		626	delays the error detetcion, but has the overwhelmign advantage that it
		627	diagnoses the error at the place where the result is expected, and not
		628	deep in some event clalback without connection to the actual code causing
		629	the problem.
595		630
596	=item $cv->begin ([group callback])	631	=item $cv->begin ([group callback])
597		632
598	=item $cv->end	633	=item $cv->end
599
600	These two methods are EXPERIMENTAL and MIGHT CHANGE.
601		634
602	These two methods can be used to combine many transactions/events into	635	These two methods can be used to combine many transactions/events into
603	one. For example, a function that pings many hosts in parallel might want	636	one. For example, a function that pings many hosts in parallel might want
604	to use a condition variable for the whole process.	637	to use a condition variable for the whole process.
605		638
…		…
607	C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end	640	C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end
608	>>, the (last) callback passed to C<begin> will be executed. That callback	641	>>, the (last) callback passed to C<begin> will be executed. That callback
609	is I<supposed> to call C<< ->send >>, but that is not required. If no	642	is I<supposed> to call C<< ->send >>, but that is not required. If no
610	callback was set, C<send> will be called without any arguments.	643	callback was set, C<send> will be called without any arguments.
611		644
612	Let's clarify this with the ping example:	645	You can think of C<< $cv->send >> giving you an OR condition (one call
		646	sends), while C<< $cv->begin >> and C<< $cv->end >> giving you an AND
		647	condition (all C<begin> calls must be C<end>'ed before the condvar sends).
		648
		649	Let's start with a simple example: you have two I/O watchers (for example,
		650	STDOUT and STDERR for a program), and you want to wait for both streams to
		651	close before activating a condvar:
		652
		653	my $cv = AnyEvent->condvar;
		654
		655	$cv->begin; # first watcher
		656	my $w1 = AnyEvent->io (fh => $fh1, cb => sub {
		657	defined sysread $fh1, my $buf, 4096
		658	or $cv->end;
		659	});
		660
		661	$cv->begin; # second watcher
		662	my $w2 = AnyEvent->io (fh => $fh2, cb => sub {
		663	defined sysread $fh2, my $buf, 4096
		664	or $cv->end;
		665	});
		666
		667	$cv->recv;
		668
		669	This works because for every event source (EOF on file handle), there is
		670	one call to C<begin>, so the condvar waits for all calls to C<end> before
		671	sending.
		672
		673	The ping example mentioned above is slightly more complicated, as the
		674	there are results to be passwd back, and the number of tasks that are
		675	begung can potentially be zero:
613		676
614	my $cv = AnyEvent->condvar;	677	my $cv = AnyEvent->condvar;
615		678
616	my %result;	679	my %result;
617	$cv->begin (sub { $cv->send (\%result) });	680	$cv->begin (sub { $cv->send (\%result) });
…		…
637	loop, which serves two important purposes: first, it sets the callback	700	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	701	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	702	C<send> is called even when C<no> hosts are being pinged (the loop
640	doesn't execute once).	703	doesn't execute once).
641		704
642	This is the general pattern when you "fan out" into multiple subrequests:	705	This is the general pattern when you "fan out" into multiple (but
643	use an outer C<begin>/C<end> pair to set the callback and ensure C<end>	706	potentially none) subrequests: use an outer C<begin>/C<end> pair to set
644	is called at least once, and then, for each subrequest you start, call	707	the callback and ensure C<end> is called at least once, and then, for each
645	C<begin> and for each subrequest you finish, call C<end>.	708	subrequest you start, call C<begin> and for each subrequest you finish,
		709	call C<end>.
646		710
647	=back	711	=back
648		712
649	=head3 METHODS FOR CONSUMERS	713	=head3 METHODS FOR CONSUMERS
650		714
…		…
666	function will call C<croak>.	730	function will call C<croak>.
667		731
668	In list context, all parameters passed to C<send> will be returned,	732	In list context, all parameters passed to C<send> will be returned,
669	in scalar context only the first one will be returned.	733	in scalar context only the first one will be returned.
670		734
		735	Note that doing a blocking wait in a callback is not supported by any
		736	event loop, that is, recursive invocation of a blocking C<< ->recv
		737	>> is not allowed, and the C<recv> call will C<croak> if such a
		738	condition is detected. This condition can be slightly loosened by using
		739	L<Coro::AnyEvent>, which allows you to do a blocking C<< ->recv >> from
		740	any thread that doesn't run the event loop itself.
		741
671	Not all event models support a blocking wait - some die in that case	742	Not all event models support a blocking wait - some die in that case
672	(programs might want to do that to stay interactive), so I<if you are	743	(programs might want to do that to stay interactive), so I<if you are
673	using this from a module, never require a blocking wait>, but let the	744	using this from a module, never require a blocking wait>. Instead, let the
674	caller decide whether the call will block or not (for example, by coupling	745	caller decide whether the call will block or not (for example, by coupling
675	condition variables with some kind of request results and supporting	746	condition variables with some kind of request results and supporting
676	callbacks so the caller knows that getting the result will not block,	747	callbacks so the caller knows that getting the result will not block,
677	while still supporting blocking waits if the caller so desires).	748	while still supporting blocking waits if the caller so desires).
678		749
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	750	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	751	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	752	time). This will work even when the event loop does not support blocking
693	waits otherwise.	753	waits otherwise.
694		754
…		…
707	variable itself. Calling C<recv> inside the callback or at any later time	767	variable itself. Calling C<recv> inside the callback or at any later time
708	is guaranteed not to block.	768	is guaranteed not to block.
709		769
710	=back	770	=back
711		771
		772	=head1 SUPPORTED EVENT LOOPS/BACKENDS
		773
		774	The available backend classes are (every class has its own manpage):
		775
		776	=over 4
		777
		778	=item Backends that are autoprobed when no other event loop can be found.
		779
		780	EV is the preferred backend when no other event loop seems to be in
		781	use. If EV is not installed, then AnyEvent will try Event, and, failing
		782	that, will fall back to its own pure-perl implementation, which is
		783	available everywhere as it comes with AnyEvent itself.
		784
		785	AnyEvent::Impl::EV based on EV (interface to libev, best choice).
		786	AnyEvent::Impl::Event based on Event, very stable, few glitches.
		787	AnyEvent::Impl::Perl pure-perl implementation, fast and portable.
		788
		789	=item Backends that are transparently being picked up when they are used.
		790
		791	These will be used when they are currently loaded when the first watcher
		792	is created, in which case it is assumed that the application is using
		793	them. This means that AnyEvent will automatically pick the right backend
		794	when the main program loads an event module before anything starts to
		795	create watchers. Nothing special needs to be done by the main program.
		796
		797	AnyEvent::Impl::Glib based on Glib, slow but very stable.
		798	AnyEvent::Impl::Tk based on Tk, very broken.
		799	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
		800	AnyEvent::Impl::POE based on POE, very slow, some limitations.
		801
		802	=item Backends with special needs.
		803
		804	Qt requires the Qt::Application to be instantiated first, but will
		805	otherwise be picked up automatically. As long as the main program
		806	instantiates the application before any AnyEvent watchers are created,
		807	everything should just work.
		808
		809	AnyEvent::Impl::Qt based on Qt.
		810
		811	Support for IO::Async can only be partial, as it is too broken and
		812	architecturally limited to even support the AnyEvent API. It also
		813	is the only event loop that needs the loop to be set explicitly, so
		814	it can only be used by a main program knowing about AnyEvent. See
		815	L<AnyEvent::Impl::Async> for the gory details.
		816
		817	AnyEvent::Impl::IOAsync based on IO::Async, cannot be autoprobed.
		818
		819	=item Event loops that are indirectly supported via other backends.
		820
		821	Some event loops can be supported via other modules:
		822
		823	There is no direct support for WxWidgets (L<Wx>) or L<Prima>.
		824
		825	B<WxWidgets> has no support for watching file handles. However, you can
		826	use WxWidgets through the POE adaptor, as POE has a Wx backend that simply
		827	polls 20 times per second, which was considered to be too horrible to even
		828	consider for AnyEvent.
		829
		830	B<Prima> is not supported as nobody seems to be using it, but it has a POE
		831	backend, so it can be supported through POE.
		832
		833	AnyEvent knows about both L<Prima> and L<Wx>, however, and will try to
		834	load L<POE> when detecting them, in the hope that POE will pick them up,
		835	in which case everything will be automatic.
		836
		837	=back
		838
712	=head1 GLOBAL VARIABLES AND FUNCTIONS	839	=head1 GLOBAL VARIABLES AND FUNCTIONS
713		840
		841	These are not normally required to use AnyEvent, but can be useful to
		842	write AnyEvent extension modules.
		843
714	=over 4	844	=over 4
715		845
716	=item $AnyEvent::MODEL	846	=item $AnyEvent::MODEL
717		847
718	Contains C<undef> until the first watcher is being created. Then it	848	Contains C<undef> until the first watcher is being created, before the
		849	backend has been autodetected.
		850
719	contains the event model that is being used, which is the name of the	851	Afterwards it contains the event model that is being used, which is the
720	Perl class implementing the model. This class is usually one of the	852	name of the Perl class implementing the model. This class is usually one
721	C<AnyEvent::Impl:xxx> modules, but can be any other class in the case	853	of the C<AnyEvent::Impl:xxx> modules, but can be any other class in the
722	AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode>).	854	case AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode> it
723		855	will be C<urxvt::anyevent>).
724	The known classes so far are:
725
726	AnyEvent::Impl::EV based on EV (an interface to libev, best choice).
727	AnyEvent::Impl::Event based on Event, second best choice.
728	AnyEvent::Impl::Perl pure-perl implementation, fast and portable.
729	AnyEvent::Impl::Glib based on Glib, third-best choice.
730	AnyEvent::Impl::Tk based on Tk, very bad choice.
731	AnyEvent::Impl::Qt based on Qt, cannot be autoprobed (see its docs).
732	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
733	AnyEvent::Impl::POE based on POE, not generic enough for full support.
734
735	There is no support for WxWidgets, as WxWidgets has no support for
736	watching file handles. However, you can use WxWidgets through the
737	POE Adaptor, as POE has a Wx backend that simply polls 20 times per
738	second, which was considered to be too horrible to even consider for
739	AnyEvent. Likewise, other POE backends can be used by AnyEvent by using
740	it's adaptor.
741
742	AnyEvent knows about L<Prima> and L<Wx> and will try to use L<POE> when
743	autodetecting them.
744		856
745	=item AnyEvent::detect	857	=item AnyEvent::detect
746		858
747	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model	859	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model
748	if necessary. You should only call this function right before you would	860	if necessary. You should only call this function right before you would
749	have created an AnyEvent watcher anyway, that is, as late as possible at	861	have created an AnyEvent watcher anyway, that is, as late as possible at
750	runtime.	862	runtime, and not e.g. while initialising of your module.
		863
		864	If you need to do some initialisation before AnyEvent watchers are
		865	created, use C<post_detect>.
751		866
752	=item $guard = AnyEvent::post_detect { BLOCK }	867	=item $guard = AnyEvent::post_detect { BLOCK }
753		868
754	Arranges for the code block to be executed as soon as the event model is	869	Arranges for the code block to be executed as soon as the event model is
755	autodetected (or immediately if this has already happened).	870	autodetected (or immediately if this has already happened).
756		871
		872	The block will be executed I<after> the actual backend has been detected
		873	(C<$AnyEvent::MODEL> is set), but I<before> any watchers have been
		874	created, so it is possible to e.g. patch C<@AnyEvent::ISA> or do
		875	other initialisations - see the sources of L<AnyEvent::Strict> or
		876	L<AnyEvent::AIO> to see how this is used.
		877
		878	The most common usage is to create some global watchers, without forcing
		879	event module detection too early, for example, L<AnyEvent::AIO> creates
		880	and installs the global L<IO::AIO> watcher in a C<post_detect> block to
		881	avoid autodetecting the event module at load time.
		882
757	If called in scalar or list context, then it creates and returns an object	883	If called in scalar or list context, then it creates and returns an object
758	that automatically removes the callback again when it is destroyed. See	884	that automatically removes the callback again when it is destroyed (or
		885	C<undef> when the hook was immediately executed). See L<AnyEvent::AIO> for
759	L<Coro::BDB> for a case where this is useful.	886	a case where this is useful.
		887
		888	Example: Create a watcher for the IO::AIO module and store it in
		889	C<$WATCHER>. Only do so after the event loop is initialised, though.
		890
		891	our WATCHER;
		892
		893	my $guard = AnyEvent::post_detect {
		894	$WATCHER = AnyEvent->io (fh => IO::AIO::poll_fileno, poll => 'r', cb => \&IO::AIO::poll_cb);
		895	};
		896
		897	# the \|\|= is important in case post_detect immediately runs the block,
		898	# as to not clobber the newly-created watcher. assigning both watcher and
		899	# post_detect guard to the same variable has the advantage of users being
		900	# able to just C<undef $WATCHER> if the watcher causes them grief.
		901
		902	$WATCHER \|\|= $guard;
760		903
761	=item @AnyEvent::post_detect	904	=item @AnyEvent::post_detect
762		905
763	If there are any code references in this array (you can C<push> to it	906	If there are any code references in this array (you can C<push> to it
764	before or after loading AnyEvent), then they will called directly after	907	before or after loading AnyEvent), then they will called directly after
765	the event loop has been chosen.	908	the event loop has been chosen.
766		909
767	You should check C<$AnyEvent::MODEL> before adding to this array, though:	910	You should check C<$AnyEvent::MODEL> before adding to this array, though:
768	if it contains a true value then the event loop has already been detected,	911	if it is defined then the event loop has already been detected, and the
769	and the array will be ignored.	912	array will be ignored.
770		913
771	Best use C<AnyEvent::post_detect { BLOCK }> instead.	914	Best use C<AnyEvent::post_detect { BLOCK }> when your application allows
		915	it,as it takes care of these details.
		916
		917	This variable is mainly useful for modules that can do something useful
		918	when AnyEvent is used and thus want to know when it is initialised, but do
		919	not need to even load it by default. This array provides the means to hook
		920	into AnyEvent passively, without loading it.
772		921
773	=back	922	=back
774		923
775	=head1 WHAT TO DO IN A MODULE	924	=head1 WHAT TO DO IN A MODULE
776		925
…		…
831		980
832		981
833	=head1 OTHER MODULES	982	=head1 OTHER MODULES
834		983
835	The following is a non-exhaustive list of additional modules that use	984	The following is a non-exhaustive list of additional modules that use
836	AnyEvent and can therefore be mixed easily with other AnyEvent modules	985	AnyEvent as a client and can therefore be mixed easily with other AnyEvent
837	in the same program. Some of the modules come with AnyEvent, some are	986	modules and other event loops in the same program. Some of the modules
838	available via CPAN.	987	come with AnyEvent, most are available via CPAN.
839		988
840	=over 4	989	=over 4
841		990
842	=item L<AnyEvent::Util>	991	=item L<AnyEvent::Util>
843		992
…		…
852		1001
853	=item L<AnyEvent::Handle>	1002	=item L<AnyEvent::Handle>
854		1003
855	Provide read and write buffers, manages watchers for reads and writes,	1004	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	1005	supports raw and formatted I/O, I/O queued and fully transparent and
857	non-blocking SSL/TLS.	1006	non-blocking SSL/TLS (via L<AnyEvent::TLS>.
858		1007
859	=item L<AnyEvent::DNS>	1008	=item L<AnyEvent::DNS>
860		1009
861	Provides rich asynchronous DNS resolver capabilities.	1010	Provides rich asynchronous DNS resolver capabilities.
862		1011
…		…
890		1039
891	=item L<AnyEvent::GPSD>	1040	=item L<AnyEvent::GPSD>
892		1041
893	A non-blocking interface to gpsd, a daemon delivering GPS information.	1042	A non-blocking interface to gpsd, a daemon delivering GPS information.
894		1043
		1044	=item L<AnyEvent::IRC>
		1045
		1046	AnyEvent based IRC client module family (replacing the older Net::IRC3).
		1047
		1048	=item L<AnyEvent::XMPP>
		1049
		1050	AnyEvent based XMPP (Jabber protocol) module family (replacing the older
		1051	Net::XMPP2>.
		1052
895	=item L<AnyEvent::IGS>	1053	=item L<AnyEvent::IGS>
896		1054
897	A non-blocking interface to the Internet Go Server protocol (used by	1055	A non-blocking interface to the Internet Go Server protocol (used by
898	L<App::IGS>).	1056	L<App::IGS>).
899		1057
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>	1058	=item L<Net::FCP>
909		1059
910	AnyEvent-based implementation of the Freenet Client Protocol, birthplace	1060	AnyEvent-based implementation of the Freenet Client Protocol, birthplace
911	of AnyEvent.	1061	of AnyEvent.
912		1062
…		…
916		1066
917	=item L<Coro>	1067	=item L<Coro>
918		1068
919	Has special support for AnyEvent via L<Coro::AnyEvent>.	1069	Has special support for AnyEvent via L<Coro::AnyEvent>.
920		1070
921	=item L<IO::Lambda>
922
923	The lambda approach to I/O - don't ask, look there. Can use AnyEvent.
924
925	=back	1071	=back
926		1072
927	=cut	1073	=cut
928		1074
929	package AnyEvent;	1075	package AnyEvent;
930		1076
		1077	# basically a tuned-down version of common::sense
		1078	sub common_sense {
931	no warnings;	1079	# no warnings
		1080	${^WARNING_BITS} ^= ${^WARNING_BITS};
932	use strict qw(vars subs);	1081	# use strict vars subs
		1082	$^H \|= 0x00000600;
		1083	}
933		1084
		1085	BEGIN { AnyEvent::common_sense }
		1086
934	use Carp;	1087	use Carp ();
935		1088
936	our $VERSION = 4.411;	1089	our $VERSION = 4.86;
937	our $MODEL;	1090	our $MODEL;
938		1091
939	our $AUTOLOAD;	1092	our $AUTOLOAD;
940	our @ISA;	1093	our @ISA;
941		1094
942	our @REGISTRY;	1095	our @REGISTRY;
943		1096
944	our $WIN32;	1097	our $WIN32;
		1098
		1099	our $VERBOSE;
945		1100
946	BEGIN {	1101	BEGIN {
947	eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }";	1102	eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }";
948	eval "sub TAINT(){ " . (${^TAINT}*1) . " }";	1103	eval "sub TAINT(){ " . (${^TAINT}*1) . " }";
949		1104
950	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}	1105	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}
951	if ${^TAINT};	1106	if ${^TAINT};
952	}
953		1107
954	our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1;	1108	$VERBOSE = $ENV{PERL_ANYEVENT_VERBOSE}*1;
		1109
		1110	}
		1111
		1112	our $MAX_SIGNAL_LATENCY = 10;
955		1113
956	our %PROTOCOL; # (ipv4\|ipv6) => (1\|2), higher numbers are preferred	1114	our %PROTOCOL; # (ipv4\|ipv6) => (1\|2), higher numbers are preferred
957		1115
958	{	1116	{
959	my $idx;	1117	my $idx;
…		…
967	[Event:: => AnyEvent::Impl::Event::],	1125	[Event:: => AnyEvent::Impl::Event::],
968	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::],	1126	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::],
969	# everything below here will not be autoprobed	1127	# everything below here will not be autoprobed
970	# as the pureperl backend should work everywhere	1128	# as the pureperl backend should work everywhere
971	# and is usually faster	1129	# and is usually faster
972	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
973	[Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers	1130	[Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers
974	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy	1131	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
		1132	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
975	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program	1133	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program
976	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza	1134	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
977	[Wx:: => AnyEvent::Impl::POE::],	1135	[Wx:: => AnyEvent::Impl::POE::],
978	[Prima:: => AnyEvent::Impl::POE::],	1136	[Prima:: => AnyEvent::Impl::POE::],
		1137	# IO::Async is just too broken - we would need workarounds for its
		1138	# byzantine signal and broken child handling, among others.
		1139	# IO::Async is rather hard to detect, as it doesn't have any
		1140	# obvious default class.
		1141	# [IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program
		1142	# [IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program
		1143	# [IO::Async::Notifier:: => AnyEvent::Impl::IOAsync::], # requires special main program
979	);	1144	);
980		1145
981	our %method = map +($_ => 1),	1146	our %method = map +($_ => 1),
982	qw(io timer time now now_update signal child idle condvar one_event DESTROY);	1147	qw(io timer time now now_update signal child idle condvar one_event DESTROY);
983		1148
…		…
987	my ($cb) = @_;	1152	my ($cb) = @_;
988		1153
989	if ($MODEL) {	1154	if ($MODEL) {
990	$cb->();	1155	$cb->();
991		1156
992	1	1157	undef
993	} else {	1158	} else {
994	push @post_detect, $cb;	1159	push @post_detect, $cb;
995		1160
996	defined wantarray	1161	defined wantarray
997	? bless \$cb, "AnyEvent::Util::postdetect"	1162	? bless \$cb, "AnyEvent::Util::postdetect"
…		…
1003	@post_detect = grep $_ != ${$_[0]}, @post_detect;	1168	@post_detect = grep $_ != ${$_[0]}, @post_detect;
1004	}	1169	}
1005		1170
1006	sub detect() {	1171	sub detect() {
1007	unless ($MODEL) {	1172	unless ($MODEL) {
1008	no strict 'refs';
1009	local $SIG{__DIE__};	1173	local $SIG{__DIE__};
1010		1174
1011	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {	1175	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {
1012	my $model = "AnyEvent::Impl::$1";	1176	my $model = "AnyEvent::Impl::$1";
1013	if (eval "require $model") {	1177	if (eval "require $model") {
1014	$MODEL = $model;	1178	$MODEL = $model;
1015	warn "AnyEvent: loaded model '$model' (forced by \$PERL_ANYEVENT_MODEL), using it.\n" if $verbose > 1;	1179	warn "AnyEvent: loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.\n" if $VERBOSE >= 2;
1016	} else {	1180	} else {
1017	warn "AnyEvent: unable to load model '$model' (from \$PERL_ANYEVENT_MODEL):\n$@" if $verbose;	1181	warn "AnyEvent: unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@" if $VERBOSE;
1018	}	1182	}
1019	}	1183	}
1020		1184
1021	# check for already loaded models	1185	# check for already loaded models
1022	unless ($MODEL) {	1186	unless ($MODEL) {
1023	for (@REGISTRY, @models) {	1187	for (@REGISTRY, @models) {
1024	my ($package, $model) = @$_;	1188	my ($package, $model) = @$_;
1025	if (${"$package\::VERSION"} > 0) {	1189	if (${"$package\::VERSION"} > 0) {
1026	if (eval "require $model") {	1190	if (eval "require $model") {
1027	$MODEL = $model;	1191	$MODEL = $model;
1028	warn "AnyEvent: autodetected model '$model', using it.\n" if $verbose > 1;	1192	warn "AnyEvent: autodetected model '$model', using it.\n" if $VERBOSE >= 2;
1029	last;	1193	last;
1030	}	1194	}
1031	}	1195	}
1032	}	1196	}
1033		1197
…		…
1038	my ($package, $model) = @$_;	1202	my ($package, $model) = @$_;
1039	if (eval "require $package"	1203	if (eval "require $package"
1040	and ${"$package\::VERSION"} > 0	1204	and ${"$package\::VERSION"} > 0
1041	and eval "require $model") {	1205	and eval "require $model") {
1042	$MODEL = $model;	1206	$MODEL = $model;
1043	warn "AnyEvent: autoprobed model '$model', using it.\n" if $verbose > 1;	1207	warn "AnyEvent: autoprobed model '$model', using it.\n" if $VERBOSE >= 2;
1044	last;	1208	last;
1045	}	1209	}
1046	}	1210	}
1047		1211
1048	$MODEL	1212	$MODEL
…		…
1064		1228
1065	sub AUTOLOAD {	1229	sub AUTOLOAD {
1066	(my $func = $AUTOLOAD) =~ s/.*://;	1230	(my $func = $AUTOLOAD) =~ s/.*://;
1067		1231
1068	$method{$func}	1232	$method{$func}
1069	or croak "$func: not a valid method for AnyEvent objects";	1233	or Carp::croak "$func: not a valid method for AnyEvent objects";
1070		1234
1071	detect unless $MODEL;	1235	detect unless $MODEL;
1072		1236
1073	my $class = shift;	1237	my $class = shift;
1074	$class->$func (@_);	1238	$class->$func (@_);
1075	}	1239	}
1076		1240
1077	# utility function to dup a filehandle. this is used by many backends	1241	# utility function to dup a filehandle. this is used by many backends
1078	# to support binding more than one watcher per filehandle (they usually	1242	# 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).	1243	# allow only one watcher per fd, so we dup it to get a different one).
1080	sub _dupfh($$$$) {	1244	sub _dupfh($$;$$) {
1081	my ($poll, $fh, $r, $w) = @_;	1245	my ($poll, $fh, $r, $w) = @_;
1082		1246
1083	# cygwin requires the fh mode to be matching, unix doesn't	1247	# cygwin requires the fh mode to be matching, unix doesn't
1084	my ($rw, $mode) = $poll eq "r" ? ($r, "<")	1248	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		1249
1088	open my $fh2, "$mode&" . fileno $fh	1250	open my $fh2, $mode, $fh
1089	or die "cannot dup() filehandle: $!,";	1251	or die "AnyEvent->io: cannot dup() filehandle in mode '$poll': $!,";
1090		1252
1091	# we assume CLOEXEC is already set by perl in all important cases	1253	# we assume CLOEXEC is already set by perl in all important cases
1092		1254
1093	($fh2, $rw)	1255	($fh2, $rw)
1094	}	1256	}
1095		1257
1096	package AnyEvent::Base;	1258	package AnyEvent::Base;
1097		1259
1098	# default implementations for many methods	1260	# default implementations for many methods
1099		1261
1100	BEGIN {	1262	sub _time {
		1263	# probe for availability of Time::HiRes
1101	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {	1264	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {
		1265	warn "AnyEvent: using Time::HiRes for sub-second timing accuracy.\n" if $VERBOSE >= 8;
1102	*_time = \&Time::HiRes::time;	1266	*_time = \&Time::HiRes::time;
1103	# if (eval "use POSIX (); (POSIX::times())...	1267	# if (eval "use POSIX (); (POSIX::times())...
1104	} else {	1268	} else {
		1269	warn "AnyEvent: using built-in time(), WARNING, no sub-second resolution!\n" if $VERBOSE;
1105	*_time = sub { time }; # epic fail	1270	*_time = sub { time }; # epic fail
1106	}	1271	}
		1272
		1273	&_time
1107	}	1274	}
1108		1275
1109	sub time { _time }	1276	sub time { _time }
1110	sub now { _time }	1277	sub now { _time }
1111	sub now_update { }	1278	sub now_update { }
…		…
1116	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"	1283	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"
1117	}	1284	}
1118		1285
1119	# default implementation for ->signal	1286	# default implementation for ->signal
1120		1287
		1288	our $HAVE_ASYNC_INTERRUPT;
1121	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);	1289	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);
		1290	our (%SIG_ASY, %SIG_ASY_W);
		1291	our ($SIG_COUNT, $SIG_TW);
1122		1292
1123	sub _signal_exec {	1293	sub _signal_exec {
		1294	$HAVE_ASYNC_INTERRUPT
		1295	? $SIGPIPE_R->drain
1124	sysread $SIGPIPE_R, my $dummy, 4;	1296	: sysread $SIGPIPE_R, my $dummy, 9;
1125		1297
1126	while (%SIG_EV) {	1298	while (%SIG_EV) {
1127	for (keys %SIG_EV) {	1299	for (keys %SIG_EV) {
1128	delete $SIG_EV{$_};	1300	delete $SIG_EV{$_};
1129	$_->() for values %{ $SIG_CB{$_} \|\| {} };	1301	$_->() for values %{ $SIG_CB{$_} \|\| {} };
1130	}	1302	}
1131	}	1303	}
1132	}	1304	}
1133		1305
		1306	# install a dumym wakeupw atcher to reduce signal catching latency
		1307	sub _sig_add() {
		1308	unless ($SIG_COUNT++) {
		1309	# try to align timer on a full-second boundary, if possible
		1310	my $NOW = AnyEvent->now;
		1311
		1312	$SIG_TW = AnyEvent->timer (
		1313	after => $MAX_SIGNAL_LATENCY - ($NOW - int $NOW),
		1314	interval => $MAX_SIGNAL_LATENCY,
		1315	cb => sub { }, # just for the PERL_ASYNC_CHECK
		1316	);
		1317	}
		1318	}
		1319
		1320	sub _sig_del {
		1321	undef $SIG_TW
		1322	unless --$SIG_COUNT;
		1323	}
		1324
		1325	sub _signal {
		1326	my (undef, %arg) = @_;
		1327
		1328	my $signal = uc $arg{signal}
		1329	or Carp::croak "required option 'signal' is missing";
		1330
		1331	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
		1332
		1333	if ($HAVE_ASYNC_INTERRUPT) {
		1334	# async::interrupt
		1335
		1336	$SIG_ASY{$signal} \|\|= do {
		1337	my $asy = new Async::Interrupt
		1338	cb => sub { undef $SIG_EV{$signal} },
		1339	signal => $signal,
		1340	pipe => [$SIGPIPE_R->filenos],
		1341	;
		1342	$asy->pipe_autodrain (0);
		1343
		1344	$asy
		1345	};
		1346
		1347	} else {
		1348	# pure perl
		1349
		1350	$SIG{$signal} \|\|= sub {
		1351	local $!;
		1352	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;
		1353	undef $SIG_EV{$signal};
		1354	};
		1355
		1356	# can't do signal processing without introducing races in pure perl,
		1357	# so limit the signal latency.
		1358	_sig_add;
		1359	}
		1360
		1361	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
		1362	}
		1363
1134	sub signal {	1364	sub signal {
1135	my (undef, %arg) = @_;	1365	# probe for availability of Async::Interrupt
		1366	if (!$ENV{PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT} && eval "use Async::Interrupt 0.6 (); 1") {
		1367	warn "AnyEvent: using Async::Interrupt for race-free signal handling.\n" if $VERBOSE >= 8;
1136		1368
1137	unless ($SIGPIPE_R) {	1369	$HAVE_ASYNC_INTERRUPT = 1;
		1370	$SIGPIPE_R = new Async::Interrupt::EventPipe;
		1371	$SIG_IO = AnyEvent->io (fh => $SIGPIPE_R->fileno, poll => "r", cb => \&_signal_exec);
		1372
		1373	} else {
		1374	warn "AnyEvent: using emulated perl signal handling with latency timer.\n" if $VERBOSE >= 8;
		1375
1138	require Fcntl;	1376	require Fcntl;
1139		1377
1140	if (AnyEvent::WIN32) {	1378	if (AnyEvent::WIN32) {
1141	require AnyEvent::Util;	1379	require AnyEvent::Util;
1142		1380
…		…
1157	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";	1395	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";
1158		1396
1159	$SIG_IO = AnyEvent->io (fh => $SIGPIPE_R, poll => "r", cb => \&_signal_exec);	1397	$SIG_IO = AnyEvent->io (fh => $SIGPIPE_R, poll => "r", cb => \&_signal_exec);
1160	}	1398	}
1161		1399
1162	my $signal = uc $arg{signal}	1400	*signal = \&_signal;
1163	or Carp::croak "required option 'signal' is missing";	1401	&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, $arg{cb}], "AnyEvent::Base::signal"
1173	}	1402	}
1174		1403
1175	sub AnyEvent::Base::signal::DESTROY {	1404	sub AnyEvent::Base::signal::DESTROY {
1176	my ($signal, $cb) = @{$_[0]};	1405	my ($signal, $cb) = @{$_[0]};
1177		1406
		1407	_sig_del;
		1408
1178	delete $SIG_CB{$signal}{$cb};	1409	delete $SIG_CB{$signal}{$cb};
1179		1410
		1411	$HAVE_ASYNC_INTERRUPT
		1412	? delete $SIG_ASY{$signal}
1180	# delete doesn't work with older perls - they then	1413	: # delete doesn't work with older perls - they then
1181	# print weird messages, or just unconditionally exit	1414	# print weird messages, or just unconditionally exit
1182	# instead of getting the default action.	1415	# instead of getting the default action.
		1416	undef $SIG{$signal}
1183	undef $SIG{$signal} unless keys %{ $SIG_CB{$signal} };	1417	unless keys %{ $SIG_CB{$signal} };
1184	}	1418	}
1185		1419
1186	# default implementation for ->child	1420	# default implementation for ->child
1187		1421
1188	our %PID_CB;	1422	our %PID_CB;
…		…
1190	our $CHLD_DELAY_W;	1424	our $CHLD_DELAY_W;
1191	our $WNOHANG;	1425	our $WNOHANG;
1192		1426
1193	sub _sigchld {	1427	sub _sigchld {
1194	while (0 < (my $pid = waitpid -1, $WNOHANG)) {	1428	while (0 < (my $pid = waitpid -1, $WNOHANG)) {
		1429	$_->($pid, $?)
1195	$_->($pid, $?) for (values %{ $PID_CB{$pid} \|\| {} }),	1430	for values %{ $PID_CB{$pid} \|\| {} },
1196	(values %{ $PID_CB{0} \|\| {} });	1431	values %{ $PID_CB{0} \|\| {} };
1197	}	1432	}
1198	}	1433	}
1199		1434
1200	sub child {	1435	sub child {
1201	my (undef, %arg) = @_;	1436	my (undef, %arg) = @_;
…		…
1203	defined (my $pid = $arg{pid} + 0)	1438	defined (my $pid = $arg{pid} + 0)
1204	or Carp::croak "required option 'pid' is missing";	1439	or Carp::croak "required option 'pid' is missing";
1205		1440
1206	$PID_CB{$pid}{$arg{cb}} = $arg{cb};	1441	$PID_CB{$pid}{$arg{cb}} = $arg{cb};
1207		1442
		1443	# WNOHANG is almost cetrainly 1 everywhere
		1444	$WNOHANG \|\|= $^O =~ /^(?:openbsd\|netbsd\|linux\|freebsd\|cygwin\|MSWin32)$/
		1445	? 1
1208	$WNOHANG \|\|= eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } \|\| 1;	1446	: eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } \|\| 1;
1209		1447
1210	unless ($CHLD_W) {	1448	unless ($CHLD_W) {
1211	$CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld);	1449	$CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld);
1212	# child could be a zombie already, so make at least one round	1450	# child could be a zombie already, so make at least one round
1213	&_sigchld;	1451	&_sigchld;
…		…
1265		1503
1266	our @ISA = AnyEvent::CondVar::Base::;	1504	our @ISA = AnyEvent::CondVar::Base::;
1267		1505
1268	package AnyEvent::CondVar::Base;	1506	package AnyEvent::CondVar::Base;
1269		1507
1270	use overload	1508	#use overload
1271	'&{}' => sub { my $self = shift; sub { $self->send (@_) } },	1509	# '&{}' => sub { my $self = shift; sub { $self->send (@_) } },
1272	fallback => 1;	1510	# fallback => 1;
		1511
		1512	# save 300+ kilobytes by dirtily hardcoding overloading
		1513	${"AnyEvent::CondVar::Base::OVERLOAD"}{dummy}++; # Register with magic by touching.
		1514	*{'AnyEvent::CondVar::Base::()'} = sub { }; # "Make it findable via fetchmethod."
		1515	*{'AnyEvent::CondVar::Base::(&{}'} = sub { my $self = shift; sub { $self->send (@_) } }; # &{}
		1516	${'AnyEvent::CondVar::Base::()'} = 1; # fallback
		1517
		1518	our $WAITING;
1273		1519
1274	sub _send {	1520	sub _send {
1275	# nop	1521	# nop
1276	}	1522	}
1277		1523
…		…
1290	sub ready {	1536	sub ready {
1291	$_[0]{_ae_sent}	1537	$_[0]{_ae_sent}
1292	}	1538	}
1293		1539
1294	sub _wait {	1540	sub _wait {
		1541	$WAITING
		1542	and !$_[0]{_ae_sent}
		1543	and Carp::croak "AnyEvent::CondVar: recursive blocking wait detected";
		1544
		1545	local $WAITING = 1;
1295	AnyEvent->one_event while !$_[0]{_ae_sent};	1546	AnyEvent->one_event while !$_[0]{_ae_sent};
1296	}	1547	}
1297		1548
1298	sub recv {	1549	sub recv {
1299	$_[0]->_wait;	1550	$_[0]->_wait;
…		…
1361	C<PERL_ANYEVENT_MODEL>.	1612	C<PERL_ANYEVENT_MODEL>.
1362		1613
1363	When set to C<2> or higher, cause AnyEvent to report to STDERR which event	1614	When set to C<2> or higher, cause AnyEvent to report to STDERR which event
1364	model it chooses.	1615	model it chooses.
1365		1616
		1617	When set to C<8> or higher, then AnyEvent will report extra information on
		1618	which optional modules it loads and how it implements certain features.
		1619
1366	=item C<PERL_ANYEVENT_STRICT>	1620	=item C<PERL_ANYEVENT_STRICT>
1367		1621
1368	AnyEvent does not do much argument checking by default, as thorough	1622	AnyEvent does not do much argument checking by default, as thorough
1369	argument checking is very costly. Setting this variable to a true value	1623	argument checking is very costly. Setting this variable to a true value
1370	will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly	1624	will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly
1371	check the arguments passed to most method calls. If it finds any problems	1625	check the arguments passed to most method calls. If it finds any problems,
1372	it will croak.	1626	it will croak.
1373		1627
1374	In other words, enables "strict" mode.	1628	In other words, enables "strict" mode.
1375		1629
1376	Unlike C<use strict>, it is definitely recommended ot keep it off in	1630	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	1631	>>, it is definitely recommended to keep it off in production. Keeping
1378	developing programs can be very useful, however.	1632	C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs
		1633	can be very useful, however.
1379		1634
1380	=item C<PERL_ANYEVENT_MODEL>	1635	=item C<PERL_ANYEVENT_MODEL>
1381		1636
1382	This can be used to specify the event model to be used by AnyEvent, before	1637	This can be used to specify the event model to be used by AnyEvent, before
1383	auto detection and -probing kicks in. It must be a string consisting	1638	auto detection and -probing kicks in. It must be a string consisting
…		…
1426		1681
1427	=item C<PERL_ANYEVENT_MAX_FORKS>	1682	=item C<PERL_ANYEVENT_MAX_FORKS>
1428		1683
1429	The maximum number of child processes that C<AnyEvent::Util::fork_call>	1684	The maximum number of child processes that C<AnyEvent::Util::fork_call>
1430	will create in parallel.	1685	will create in parallel.
		1686
		1687	=item C<PERL_ANYEVENT_MAX_OUTSTANDING_DNS>
		1688
		1689	The default value for the C<max_outstanding> parameter for the default DNS
		1690	resolver - this is the maximum number of parallel DNS requests that are
		1691	sent to the DNS server.
		1692
		1693	=item C<PERL_ANYEVENT_RESOLV_CONF>
		1694
		1695	The file to use instead of F</etc/resolv.conf> (or OS-specific
		1696	configuration) in the default resolver. When set to the empty string, no
		1697	default config will be used.
		1698
		1699	=item C<PERL_ANYEVENT_CA_FILE>, C<PERL_ANYEVENT_CA_PATH>.
		1700
		1701	When neither C<ca_file> nor C<ca_path> was specified during
		1702	L<AnyEvent::TLS> context creation, and either of these environment
		1703	variables exist, they will be used to specify CA certificate locations
		1704	instead of a system-dependent default.
		1705
		1706	=item C<PERL_ANYEVENT_AVOID_GUARD> and C<PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT>
		1707
		1708	When these are set to C<1>, then the respective modules are not
		1709	loaded. Mostly good for testing AnyEvent itself.
1431		1710
1432	=back	1711	=back
1433		1712
1434	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE	1713	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE
1435		1714
…		…
1680	EV/Any 100000 224 2.88 0.34 0.27 EV + AnyEvent watchers	1959	EV/Any 100000 224 2.88 0.34 0.27 EV + AnyEvent watchers
1681	CoroEV/Any 100000 224 2.85 0.35 0.28 coroutines + Coro::Signal	1960	CoroEV/Any 100000 224 2.85 0.35 0.28 coroutines + Coro::Signal
1682	Perl/Any 100000 452 4.13 0.73 0.95 pure perl implementation	1961	Perl/Any 100000 452 4.13 0.73 0.95 pure perl implementation
1683	Event/Event 16000 517 32.20 31.80 0.81 Event native interface	1962	Event/Event 16000 517 32.20 31.80 0.81 Event native interface
1684	Event/Any 16000 590 35.85 31.55 1.06 Event + AnyEvent watchers	1963	Event/Any 16000 590 35.85 31.55 1.06 Event + AnyEvent watchers
		1964	IOAsync/Any 16000 989 38.10 32.77 11.13 via IO::Async::Loop::IO_Poll
		1965	IOAsync/Any 16000 990 37.59 29.50 10.61 via IO::Async::Loop::Epoll
1685	Glib/Any 16000 1357 102.33 12.31 51.00 quadratic behaviour	1966	Glib/Any 16000 1357 102.33 12.31 51.00 quadratic behaviour
1686	Tk/Any 2000 1860 27.20 66.31 14.00 SEGV with >> 2000 watchers	1967	Tk/Any 2000 1860 27.20 66.31 14.00 SEGV with >> 2000 watchers
1687	POE/Event 2000 6328 109.99 751.67 14.02 via POE::Loop::Event	1968	POE/Event 2000 6328 109.99 751.67 14.02 via POE::Loop::Event
1688	POE/Select 2000 6027 94.54 809.13 579.80 via POE::Loop::Select	1969	POE/Select 2000 6027 94.54 809.13 579.80 via POE::Loop::Select
1689		1970
…		…
1718	performance becomes really bad with lots of file descriptors (and few of	1999	performance becomes really bad with lots of file descriptors (and few of
1719	them active), of course, but this was not subject of this benchmark.	2000	them active), of course, but this was not subject of this benchmark.
1720		2001
1721	The C<Event> module has a relatively high setup and callback invocation	2002	The C<Event> module has a relatively high setup and callback invocation
1722	cost, but overall scores in on the third place.	2003	cost, but overall scores in on the third place.
		2004
		2005	C<IO::Async> performs admirably well, about on par with C<Event>, even
		2006	when using its pure perl backend.
1723		2007
1724	C<Glib>'s memory usage is quite a bit higher, but it features a	2008	C<Glib>'s memory usage is quite a bit higher, but it features a
1725	faster callback invocation and overall ends up in the same class as	2009	faster callback invocation and overall ends up in the same class as
1726	C<Event>. However, Glib scales extremely badly, doubling the number of	2010	C<Event>. However, Glib scales extremely badly, doubling the number of
1727	watchers increases the processing time by more than a factor of four,	2011	watchers increases the processing time by more than a factor of four,
…		…
1805	it to another server. This includes deleting the old timeout and creating	2089	it to another server. This includes deleting the old timeout and creating
1806	a new one that moves the timeout into the future.	2090	a new one that moves the timeout into the future.
1807		2091
1808	=head3 Results	2092	=head3 Results
1809		2093
1810	name sockets create request	2094	name sockets create request
1811	EV 20000 69.01 11.16	2095	EV 20000 69.01 11.16
1812	Perl 20000 73.32 35.87	2096	Perl 20000 73.32 35.87
		2097	IOAsync 20000 157.00 98.14 epoll
		2098	IOAsync 20000 159.31 616.06 poll
1813	Event 20000 212.62 257.32	2099	Event 20000 212.62 257.32
1814	Glib 20000 651.16 1896.30	2100	Glib 20000 651.16 1896.30
1815	POE 20000 349.67 12317.24 uses POE::Loop::Event	2101	POE 20000 349.67 12317.24 uses POE::Loop::Event
1816		2102
1817	=head3 Discussion	2103	=head3 Discussion
1818		2104
1819	This benchmark I<does> measure scalability and overall performance of the	2105	This benchmark I<does> measure scalability and overall performance of the
1820	particular event loop.	2106	particular event loop.
…		…
1822	EV is again fastest. Since it is using epoll on my system, the setup time	2108	EV is again fastest. Since it is using epoll on my system, the setup time
1823	is relatively high, though.	2109	is relatively high, though.
1824		2110
1825	Perl surprisingly comes second. It is much faster than the C-based event	2111	Perl surprisingly comes second. It is much faster than the C-based event
1826	loops Event and Glib.	2112	loops Event and Glib.
		2113
		2114	IO::Async performs very well when using its epoll backend, and still quite
		2115	good compared to Glib when using its pure perl backend.
1827		2116
1828	Event suffers from high setup time as well (look at its code and you will	2117	Event suffers from high setup time as well (look at its code and you will
1829	understand why). Callback invocation also has a high overhead compared to	2118	understand why). Callback invocation also has a high overhead compared to
1830	the C<< $_->() for .. >>-style loop that the Perl event loop uses. Event	2119	the C<< $_->() for .. >>-style loop that the Perl event loop uses. Event
1831	uses select or poll in basically all documented configurations.	2120	uses select or poll in basically all documented configurations.
…		…
1900		2189
1901	Recently I was told about the benchmark in the IO::Lambda manpage, which	2190	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	2191	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	2192	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	2193	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	2194	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	2195	very optimal. But how would AnyEvent compare when used without the extra
1907	baggage? To explore this, I wrote the equivalent benchmark for AnyEvent.	2196	baggage? To explore this, I wrote the equivalent benchmark for AnyEvent.
1908		2197
1909	The benchmark itself creates an echo-server, and then, for 500 times,	2198	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	2199	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	2200	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.	2201	test the efficiency of the framework or much non-blocking I/O, but it is a
		2202	benchmark nevertheless.
1913		2203
1914	name runtime	2204	name runtime
1915	Lambda/select 0.330 sec	2205	Lambda/select 0.330 sec
1916	+ optimized 0.122 sec	2206	+ optimized 0.122 sec
1917	Lambda/AnyEvent 0.327 sec	2207	Lambda/AnyEvent 0.327 sec
…		…
1923		2213
1924	AnyEvent/select/nb 0.085 sec	2214	AnyEvent/select/nb 0.085 sec
1925	AnyEvent/EV/nb 0.068 sec	2215	AnyEvent/EV/nb 0.068 sec
1926	+state machine 0.134 sec	2216	+state machine 0.134 sec
1927		2217
1928	The benchmark is also a bit unfair (my fault) - the IO::Lambda	2218	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,	2219	benchmarks actually make blocking connects and use 100% blocking I/O,
1930	defeating the purpose of an event-based solution. All of the newly	2220	defeating the purpose of an event-based solution. All of the newly
1931	written AnyEvent benchmarks use 100% non-blocking connects (using	2221	written AnyEvent benchmarks use 100% non-blocking connects (using
1932	AnyEvent::Socket::tcp_connect and the asynchronous pure perl DNS	2222	AnyEvent::Socket::tcp_connect and the asynchronous pure perl DNS
1933	resolver), so AnyEvent is at a disadvantage here as non-blocking connects	2223	resolver), so AnyEvent is at a disadvantage here, as non-blocking connects
1934	generally require a lot more bookkeeping and event handling than blocking	2224	generally require a lot more bookkeeping and event handling than blocking
1935	connects (which involve a single syscall only).	2225	connects (which involve a single syscall only).
1936		2226
1937	The last AnyEvent benchmark additionally uses L<AnyEvent::Handle>, which	2227	The last AnyEvent benchmark additionally uses L<AnyEvent::Handle>, which
1938	offers similar expressive power as POE and IO::Lambda (using conventional	2228	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%	2229	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.	2230	non-blocking, further placing it at a disadvantage.
1941		2231
1942	As you can see, AnyEvent + EV even beats the hand-optimised "raw sockets	2232	As you can see, the AnyEvent + EV combination even beats the
1943	benchmark", while AnyEvent + its pure perl backend easily beats	2233	hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl
1944	IO::Lambda and POE.	2234	backend easily beats IO::Lambda and POE.
1945		2235
1946	And even the 100% non-blocking version written using the high-level (and	2236	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,	2237	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	2238	large margin, even though it does all of DNS, tcp-connect and socket I/O
1949	non-blocking way.	2239	in a non-blocking way.
1950		2240
1951	The two AnyEvent benchmarks can be found as F<eg/ae0.pl> and F<eg/ae2.pl>	2241	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	2242	F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are
1953	IO::lambda distribution and were used without any changes.	2243	part of the IO::lambda distribution and were used without any changes.
1954		2244
1955		2245
1956	=head1 SIGNALS	2246	=head1 SIGNALS
1957		2247
1958	AnyEvent currently installs handlers for these signals:	2248	AnyEvent currently installs handlers for these signals:
…		…
1962	=item SIGCHLD	2252	=item SIGCHLD
1963		2253
1964	A handler for C<SIGCHLD> is installed by AnyEvent's child watcher	2254	A handler for C<SIGCHLD> is installed by AnyEvent's child watcher
1965	emulation for event loops that do not support them natively. Also, some	2255	emulation for event loops that do not support them natively. Also, some
1966	event loops install a similar handler.	2256	event loops install a similar handler.
		2257
		2258	Additionally, when AnyEvent is loaded and SIGCHLD is set to IGNORE, then
		2259	AnyEvent will reset it to default, to avoid losing child exit statuses.
1967		2260
1968	=item SIGPIPE	2261	=item SIGPIPE
1969		2262
1970	A no-op handler is installed for C<SIGPIPE> when C<$SIG{PIPE}> is C<undef>	2263	A no-op handler is installed for C<SIGPIPE> when C<$SIG{PIPE}> is C<undef>
1971	when AnyEvent gets loaded.	2264	when AnyEvent gets loaded.
…		…
1983		2276
1984	=back	2277	=back
1985		2278
1986	=cut	2279	=cut
1987		2280
		2281	undef $SIG{CHLD}
		2282	if $SIG{CHLD} eq 'IGNORE';
		2283
1988	$SIG{PIPE} = sub { }	2284	$SIG{PIPE} = sub { }
1989	unless defined $SIG{PIPE};	2285	unless defined $SIG{PIPE};
		2286
		2287	=head1 RECOMMENDED/OPTIONAL MODULES
		2288
		2289	One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and
		2290	it's built-in modules) are required to use it.
		2291
		2292	That does not mean that AnyEvent won't take advantage of some additional
		2293	modules if they are installed.
		2294
		2295	This section epxlains which additional modules will be used, and how they
		2296	affect AnyEvent's operetion.
		2297
		2298	=over 4
		2299
		2300	=item L<Async::Interrupt>
		2301
		2302	This slightly arcane module is used to implement fast signal handling: To
		2303	my knowledge, there is no way to do completely race-free and quick
		2304	signal handling in pure perl. To ensure that signals still get
		2305	delivered, AnyEvent will start an interval timer to wake up perl (and
		2306	catch the signals) with some delay (default is 10 seconds, look for
		2307	C<$AnyEvent::MAX_SIGNAL_LATENCY>).
		2308
		2309	If this module is available, then it will be used to implement signal
		2310	catching, which means that signals will not be delayed, and the event loop
		2311	will not be interrupted regularly, which is more efficient (And good for
		2312	battery life on laptops).
		2313
		2314	This affects not just the pure-perl event loop, but also other event loops
		2315	that have no signal handling on their own (e.g. Glib, Tk, Qt).
		2316
		2317	Some event loops (POE, Event, Event::Lib) offer signal watchers natively,
		2318	and either employ their own workarounds (POE) or use AnyEvent's workaround
		2319	(using C<$AnyEvent::MAX_SIGNAL_LATENCY>). Installing L<Async::Interrupt>
		2320	does nothing for those backends.
		2321
		2322	=item L<EV>
		2323
		2324	This module isn't really "optional", as it is simply one of the backend
		2325	event loops that AnyEvent can use. However, it is simply the best event
		2326	loop available in terms of features, speed and stability: It supports
		2327	the AnyEvent API optimally, implements all the watcher types in XS, does
		2328	automatic timer adjustments even when no monotonic clock is available,
		2329	can take avdantage of advanced kernel interfaces such as C<epoll> and
		2330	C<kqueue>, and is the fastest backend I<by far>. You can even embed
		2331	L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>).
		2332
		2333	=item L<Guard>
		2334
		2335	The guard module, when used, will be used to implement
		2336	C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a
		2337	lot less memory), but otherwise doesn't affect guard operation much. It is
		2338	purely used for performance.
		2339
		2340	=item L<JSON> and L<JSON::XS>
		2341
		2342	This module is required when you want to read or write JSON data via
		2343	L<AnyEvent::Handle>. It is also written in pure-perl, but can take
		2344	advantage of the ultra-high-speed L<JSON::XS> module when it is installed.
		2345
		2346	In fact, L<AnyEvent::Handle> will use L<JSON::XS> by default if it is
		2347	installed.
		2348
		2349	=item L<Net::SSLeay>
		2350
		2351	Implementing TLS/SSL in Perl is certainly interesting, but not very
		2352	worthwhile: If this module is installed, then L<AnyEvent::Handle> (with
		2353	the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL.
		2354
		2355	=item L<Time::HiRes>
		2356
		2357	This module is part of perl since release 5.008. It will be used when the
		2358	chosen event library does not come with a timing source on it's own. The
		2359	pure-perl event loop (L<AnyEvent::Impl::Perl>) will additionally use it to
		2360	try to use a monotonic clock for timing stability.
		2361
		2362	=back
1990		2363
1991		2364
1992	=head1 FORK	2365	=head1 FORK
1993		2366
1994	Most event libraries are not fork-safe. The ones who are usually are	2367	Most event libraries are not fork-safe. The ones who are usually are
1995	because they rely on inefficient but fork-safe C<select> or C<poll>	2368	because they rely on inefficient but fork-safe C<select> or C<poll>
1996	calls. Only L<EV> is fully fork-aware.	2369	calls. Only L<EV> is fully fork-aware.
1997		2370
1998	If you have to fork, you must either do so I<before> creating your first	2371	If you have to fork, you must either do so I<before> creating your first
1999	watcher OR you must not use AnyEvent at all in the child.	2372	watcher OR you must not use AnyEvent at all in the child OR you must do
		2373	something completely out of the scope of AnyEvent.
2000		2374
2001		2375
2002	=head1 SECURITY CONSIDERATIONS	2376	=head1 SECURITY CONSIDERATIONS
2003		2377
2004	AnyEvent can be forced to load any event model via	2378	AnyEvent can be forced to load any event model via
…		…
2018	Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can	2392	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	2393	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	2394	probably even less useful to an attacker than PERL_ANYEVENT_MODEL), and
2021	$ENV{PERL_ANYEVENT_STRICT}.	2395	$ENV{PERL_ANYEVENT_STRICT}.
2022		2396
		2397	Note that AnyEvent will remove I<all> environment variables starting with
		2398	C<PERL_ANYEVENT_> from C<%ENV> when it is loaded while taint mode is
		2399	enabled.
		2400
2023		2401
2024	=head1 BUGS	2402	=head1 BUGS
2025		2403
2026	Perl 5.8 has numerous memleaks that sometimes hit this module and are hard	2404	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	2405	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>.	2416	L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.
2039		2417
2040	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,	2418	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,
2041	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,	2419	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,
2042	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,	2420	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,
2043	L<AnyEvent::Impl::POE>.	2421	L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>.
2044		2422
2045	Non-blocking file handles, sockets, TCP clients and	2423	Non-blocking file handles, sockets, TCP clients and
2046	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>.	2424	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.
2047		2425
2048	Asynchronous DNS: L<AnyEvent::DNS>.	2426	Asynchronous DNS: L<AnyEvent::DNS>.
2049		2427
2050	Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>,	2428	Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>,
		2429	L<Coro::Event>,
2051		2430
2052	Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>, L<AnyEvent::DNS>.	2431	Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::XMPP>,
		2432	L<AnyEvent::HTTP>.
2053		2433
2054		2434
2055	=head1 AUTHOR	2435	=head1 AUTHOR
2056		2436
2057	Marc Lehmann <schmorp@schmorp.de>	2437	Marc Lehmann <schmorp@schmorp.de>

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Comparing AnyEvent/lib/AnyEvent.pm (file contents): Revision 1.216 by root, Tue Jun 23 12:21:34 2009 UTC vs. Revision 1.253 by root, Tue Jul 21 06:00:47 2009 UTC

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Comparing AnyEvent/lib/AnyEvent.pm (file contents):
Revision 1.216 by root, Tue Jun 23 12:21:34 2009 UTC vs.
Revision 1.253 by root, Tue Jul 21 06:00:47 2009 UTC