[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 1.242 by root, Fri Jul 17 22:05:12 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.
…		…
353	invocation, and callback invocation will be synchronous. Synchronous means	361	invocation, and callback invocation will be synchronous. Synchronous means
354	that it might take a while until the signal gets handled by the process,	362	that it might take a while until the signal gets handled by the process,
355	but it is guaranteed not to interrupt any other callbacks.	363	but it is guaranteed not to interrupt any other callbacks.
356		364
357	The main advantage of using these watchers is that you can share a signal	365	The main advantage of using these watchers is that you can share a signal
358	between multiple watchers.	366	between multiple watchers, and AnyEvent will ensure that signals will not
		367	interrupt your program at bad times.
359		368
360	This watcher might use C<%SIG>, so programs overwriting those signals	369	This watcher might use C<%SIG> (depending on the event loop used),
361	directly will likely not work correctly.	370	so programs overwriting those signals directly will likely not work
		371	correctly.
		372
		373	Also note that many event loops (e.g. Glib, Tk, Qt, IO::Async) do not
		374	support attaching callbacks to signals, which is a pity, as you cannot do
		375	race-free signal handling in perl. AnyEvent will try to do it's best, but
		376	in some cases, signals will be delayed. The maximum time a signal might
		377	be delayed is specified in C<$AnyEvent::MAX_SIGNAL_LATENCY> (default: 10
		378	seconds). This variable can be changed only before the first signal
		379	watcher is created, and should be left alone otherwise. Higher values
		380	will cause fewer spurious wake-ups, which is better for power and CPU
		381	saving. All these problems can be avoided by installing the optional
		382	L<Async::Interrupt> module.
362		383
363	Example: exit on SIGINT	384	Example: exit on SIGINT
364		385
365	my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });	386	my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });
366		387
…		…
384		405
385	There is a slight catch to child watchers, however: you usually start them	406	There is a slight catch to child watchers, however: you usually start them
386	I<after> the child process was created, and this means the process could	407	I<after> the child process was created, and this means the process could
387	have exited already (and no SIGCHLD will be sent anymore).	408	have exited already (and no SIGCHLD will be sent anymore).
388		409
389	Not all event models handle this correctly (POE doesn't), but even for	410	Not all event models handle this correctly (neither POE nor IO::Async do,
		411	see their AnyEvent::Impl manpages for details), but even for event models
390	event models that I<do> handle this correctly, they usually need to be	412	that I<do> handle this correctly, they usually need to be loaded before
391	loaded before the process exits (i.e. before you fork in the first place).	413	the process exits (i.e. before you fork in the first place). AnyEvent's
		414	pure perl event loop handles all cases correctly regardless of when you
		415	start the watcher.
392		416
393	This means you cannot create a child watcher as the very first thing in an	417	This means you cannot create a child watcher as the very first
394	AnyEvent program, you I<have> to create at least one watcher before you	418	thing in an AnyEvent program, you I<have> to create at least one
395	C<fork> the child (alternatively, you can call C<AnyEvent::detect>).	419	watcher before you C<fork> the child (alternatively, you can call
		420	C<AnyEvent::detect>).
		421
		422	As most event loops do not support waiting for child events, they will be
		423	emulated by AnyEvent in most cases, in which the latency and race problems
		424	mentioned in the description of signal watchers apply.
396		425
397	Example: fork a process and wait for it	426	Example: fork a process and wait for it
398		427
399	my $done = AnyEvent->condvar;	428	my $done = AnyEvent->condvar;
400		429
…		…
410	);	439	);
411		440
412	# do something else, then wait for process exit	441	# do something else, then wait for process exit
413	$done->recv;	442	$done->recv;
414		443
		444	=head2 IDLE WATCHERS
		445
		446	Sometimes there is a need to do something, but it is not so important
		447	to do it instantly, but only when there is nothing better to do. This
		448	"nothing better to do" is usually defined to be "no other events need
		449	attention by the event loop".
		450
		451	Idle watchers ideally get invoked when the event loop has nothing
		452	better to do, just before it would block the process to wait for new
		453	events. Instead of blocking, the idle watcher is invoked.
		454
		455	Most event loops unfortunately do not really support idle watchers (only
		456	EV, Event and Glib do it in a usable fashion) - for the rest, AnyEvent
		457	will simply call the callback "from time to time".
		458
		459	Example: read lines from STDIN, but only process them when the
		460	program is otherwise idle:
		461
		462	my @lines; # read data
		463	my $idle_w;
		464	my $io_w = AnyEvent->io (fh => \*STDIN, poll => 'r', cb => sub {
		465	push @lines, scalar <STDIN>;
		466
		467	# start an idle watcher, if not already done
		468	$idle_w \|\|= AnyEvent->idle (cb => sub {
		469	# handle only one line, when there are lines left
		470	if (my $line = shift @lines) {
		471	print "handled when idle: $line";
		472	} else {
		473	# otherwise disable the idle watcher again
		474	undef $idle_w;
		475	}
		476	});
		477	});
		478
415	=head2 CONDITION VARIABLES	479	=head2 CONDITION VARIABLES
416		480
417	If you are familiar with some event loops you will know that all of them	481	If you are familiar with some event loops you will know that all of them
418	require you to run some blocking "loop", "run" or similar function that	482	require you to run some blocking "loop", "run" or similar function that
419	will actively watch for new events and call your callbacks.	483	will actively watch for new events and call your callbacks.
420		484
421	AnyEvent is different, it expects somebody else to run the event loop and	485	AnyEvent is slightly different: it expects somebody else to run the event
422	will only block when necessary (usually when told by the user).	486	loop and will only block when necessary (usually when told by the user).
423		487
424	The instrument to do that is called a "condition variable", so called	488	The instrument to do that is called a "condition variable", so called
425	because they represent a condition that must become true.	489	because they represent a condition that must become true.
426		490
		491	Now is probably a good time to look at the examples further below.
		492
427	Condition variables can be created by calling the C<< AnyEvent->condvar	493	Condition variables can be created by calling the C<< AnyEvent->condvar
428	>> method, usually without arguments. The only argument pair allowed is	494	>> 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	495	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	496	becomes true, with the condition variable as the first argument (but not
432	the results).	497	the results).
433		498
434	After creation, the condition variable is "false" until it becomes "true"	499	After creation, the condition variable is "false" until it becomes "true"
…		…
483	after => 1,	548	after => 1,
484	cb => sub { $result_ready->send },	549	cb => sub { $result_ready->send },
485	);	550	);
486		551
487	# this "blocks" (while handling events) till the callback	552	# this "blocks" (while handling events) till the callback
488	# calls send	553	# calls -<send
489	$result_ready->recv;	554	$result_ready->recv;
490		555
491	Example: wait for a timer, but take advantage of the fact that	556	Example: wait for a timer, but take advantage of the fact that condition
492	condition variables are also code references.	557	variables are also callable directly.
493		558
494	my $done = AnyEvent->condvar;	559	my $done = AnyEvent->condvar;
495	my $delay = AnyEvent->timer (after => 5, cb => $done);	560	my $delay = AnyEvent->timer (after => 5, cb => $done);
496	$done->recv;	561	$done->recv;
497		562
…		…
503		568
504	...	569	...
505		570
506	my @info = $couchdb->info->recv;	571	my @info = $couchdb->info->recv;
507		572
508	And this is how you would just ste a callback to be called whenever the	573	And this is how you would just set a callback to be called whenever the
509	results are available:	574	results are available:
510		575
511	$couchdb->info->cb (sub {	576	$couchdb->info->cb (sub {
512	my @info = $_[0]->recv;	577	my @info = $_[0]->recv;
513	});	578	});
…		…
531	immediately from within send.	596	immediately from within send.
532		597
533	Any arguments passed to the C<send> call will be returned by all	598	Any arguments passed to the C<send> call will be returned by all
534	future C<< ->recv >> calls.	599	future C<< ->recv >> calls.
535		600
536	Condition variables are overloaded so one can call them directly	601	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	602	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	603	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		604
545	=item $cv->croak ($error)	605	=item $cv->croak ($error)
546		606
547	Similar to send, but causes all call's to C<< ->recv >> to invoke	607	Similar to send, but causes all call's to C<< ->recv >> to invoke
548	C<Carp::croak> with the given error message/object/scalar.	608	C<Carp::croak> with the given error message/object/scalar.
549		609
550	This can be used to signal any errors to the condition variable	610	This can be used to signal any errors to the condition variable
551	user/consumer.	611	user/consumer. Doing it this way instead of calling C<croak> directly
		612	delays the error detetcion, but has the overwhelmign advantage that it
		613	diagnoses the error at the place where the result is expected, and not
		614	deep in some event clalback without connection to the actual code causing
		615	the problem.
552		616
553	=item $cv->begin ([group callback])	617	=item $cv->begin ([group callback])
554		618
555	=item $cv->end	619	=item $cv->end
556
557	These two methods are EXPERIMENTAL and MIGHT CHANGE.
558		620
559	These two methods can be used to combine many transactions/events into	621	These two methods can be used to combine many transactions/events into
560	one. For example, a function that pings many hosts in parallel might want	622	one. For example, a function that pings many hosts in parallel might want
561	to use a condition variable for the whole process.	623	to use a condition variable for the whole process.
562		624
…		…
564	C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end	626	C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end
565	>>, the (last) callback passed to C<begin> will be executed. That callback	627	>>, the (last) callback passed to C<begin> will be executed. That callback
566	is I<supposed> to call C<< ->send >>, but that is not required. If no	628	is I<supposed> to call C<< ->send >>, but that is not required. If no
567	callback was set, C<send> will be called without any arguments.	629	callback was set, C<send> will be called without any arguments.
568		630
569	Let's clarify this with the ping example:	631	You can think of C<< $cv->send >> giving you an OR condition (one call
		632	sends), while C<< $cv->begin >> and C<< $cv->end >> giving you an AND
		633	condition (all C<begin> calls must be C<end>'ed before the condvar sends).
		634
		635	Let's start with a simple example: you have two I/O watchers (for example,
		636	STDOUT and STDERR for a program), and you want to wait for both streams to
		637	close before activating a condvar:
		638
		639	my $cv = AnyEvent->condvar;
		640
		641	$cv->begin; # first watcher
		642	my $w1 = AnyEvent->io (fh => $fh1, cb => sub {
		643	defined sysread $fh1, my $buf, 4096
		644	or $cv->end;
		645	});
		646
		647	$cv->begin; # second watcher
		648	my $w2 = AnyEvent->io (fh => $fh2, cb => sub {
		649	defined sysread $fh2, my $buf, 4096
		650	or $cv->end;
		651	});
		652
		653	$cv->recv;
		654
		655	This works because for every event source (EOF on file handle), there is
		656	one call to C<begin>, so the condvar waits for all calls to C<end> before
		657	sending.
		658
		659	The ping example mentioned above is slightly more complicated, as the
		660	there are results to be passwd back, and the number of tasks that are
		661	begung can potentially be zero:
570		662
571	my $cv = AnyEvent->condvar;	663	my $cv = AnyEvent->condvar;
572		664
573	my %result;	665	my %result;
574	$cv->begin (sub { $cv->send (\%result) });	666	$cv->begin (sub { $cv->send (\%result) });
…		…
594	loop, which serves two important purposes: first, it sets the callback	686	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	687	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	688	C<send> is called even when C<no> hosts are being pinged (the loop
597	doesn't execute once).	689	doesn't execute once).
598		690
599	This is the general pattern when you "fan out" into multiple subrequests:	691	This is the general pattern when you "fan out" into multiple (but
600	use an outer C<begin>/C<end> pair to set the callback and ensure C<end>	692	potentially none) subrequests: use an outer C<begin>/C<end> pair to set
601	is called at least once, and then, for each subrequest you start, call	693	the callback and ensure C<end> is called at least once, and then, for each
602	C<begin> and for each subrequest you finish, call C<end>.	694	subrequest you start, call C<begin> and for each subrequest you finish,
		695	call C<end>.
603		696
604	=back	697	=back
605		698
606	=head3 METHODS FOR CONSUMERS	699	=head3 METHODS FOR CONSUMERS
607		700
…		…
623	function will call C<croak>.	716	function will call C<croak>.
624		717
625	In list context, all parameters passed to C<send> will be returned,	718	In list context, all parameters passed to C<send> will be returned,
626	in scalar context only the first one will be returned.	719	in scalar context only the first one will be returned.
627		720
		721	Note that doing a blocking wait in a callback is not supported by any
		722	event loop, that is, recursive invocation of a blocking C<< ->recv
		723	>> is not allowed, and the C<recv> call will C<croak> if such a
		724	condition is detected. This condition can be slightly loosened by using
		725	L<Coro::AnyEvent>, which allows you to do a blocking C<< ->recv >> from
		726	any thread that doesn't run the event loop itself.
		727
628	Not all event models support a blocking wait - some die in that case	728	Not all event models support a blocking wait - some die in that case
629	(programs might want to do that to stay interactive), so I<if you are	729	(programs might want to do that to stay interactive), so I<if you are
630	using this from a module, never require a blocking wait>, but let the	730	using this from a module, never require a blocking wait>. Instead, let the
631	caller decide whether the call will block or not (for example, by coupling	731	caller decide whether the call will block or not (for example, by coupling
632	condition variables with some kind of request results and supporting	732	condition variables with some kind of request results and supporting
633	callbacks so the caller knows that getting the result will not block,	733	callbacks so the caller knows that getting the result will not block,
634	while still supporting blocking waits if the caller so desires).	734	while still supporting blocking waits if the caller so desires).
635		735
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	736	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	737	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	738	time). This will work even when the event loop does not support blocking
650	waits otherwise.	739	waits otherwise.
651		740
…		…
664	variable itself. Calling C<recv> inside the callback or at any later time	753	variable itself. Calling C<recv> inside the callback or at any later time
665	is guaranteed not to block.	754	is guaranteed not to block.
666		755
667	=back	756	=back
668		757
		758	=head1 SUPPORTED EVENT LOOPS/BACKENDS
		759
		760	The available backend classes are (every class has its own manpage):
		761
		762	=over 4
		763
		764	=item Backends that are autoprobed when no other event loop can be found.
		765
		766	EV is the preferred backend when no other event loop seems to be in
		767	use. If EV is not installed, then AnyEvent will try Event, and, failing
		768	that, will fall back to its own pure-perl implementation, which is
		769	available everywhere as it comes with AnyEvent itself.
		770
		771	AnyEvent::Impl::EV based on EV (interface to libev, best choice).
		772	AnyEvent::Impl::Event based on Event, very stable, few glitches.
		773	AnyEvent::Impl::Perl pure-perl implementation, fast and portable.
		774
		775	=item Backends that are transparently being picked up when they are used.
		776
		777	These will be used when they are currently loaded when the first watcher
		778	is created, in which case it is assumed that the application is using
		779	them. This means that AnyEvent will automatically pick the right backend
		780	when the main program loads an event module before anything starts to
		781	create watchers. Nothing special needs to be done by the main program.
		782
		783	AnyEvent::Impl::Glib based on Glib, slow but very stable.
		784	AnyEvent::Impl::Tk based on Tk, very broken.
		785	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
		786	AnyEvent::Impl::POE based on POE, very slow, some limitations.
		787
		788	=item Backends with special needs.
		789
		790	Qt requires the Qt::Application to be instantiated first, but will
		791	otherwise be picked up automatically. As long as the main program
		792	instantiates the application before any AnyEvent watchers are created,
		793	everything should just work.
		794
		795	AnyEvent::Impl::Qt based on Qt.
		796
		797	Support for IO::Async can only be partial, as it is too broken and
		798	architecturally limited to even support the AnyEvent API. It also
		799	is the only event loop that needs the loop to be set explicitly, so
		800	it can only be used by a main program knowing about AnyEvent. See
		801	L<AnyEvent::Impl::Async> for the gory details.
		802
		803	AnyEvent::Impl::IOAsync based on IO::Async, cannot be autoprobed.
		804
		805	=item Event loops that are indirectly supported via other backends.
		806
		807	Some event loops can be supported via other modules:
		808
		809	There is no direct support for WxWidgets (L<Wx>) or L<Prima>.
		810
		811	B<WxWidgets> has no support for watching file handles. However, you can
		812	use WxWidgets through the POE adaptor, as POE has a Wx backend that simply
		813	polls 20 times per second, which was considered to be too horrible to even
		814	consider for AnyEvent.
		815
		816	B<Prima> is not supported as nobody seems to be using it, but it has a POE
		817	backend, so it can be supported through POE.
		818
		819	AnyEvent knows about both L<Prima> and L<Wx>, however, and will try to
		820	load L<POE> when detecting them, in the hope that POE will pick them up,
		821	in which case everything will be automatic.
		822
		823	=back
		824
669	=head1 GLOBAL VARIABLES AND FUNCTIONS	825	=head1 GLOBAL VARIABLES AND FUNCTIONS
670		826
		827	These are not normally required to use AnyEvent, but can be useful to
		828	write AnyEvent extension modules.
		829
671	=over 4	830	=over 4
672		831
673	=item $AnyEvent::MODEL	832	=item $AnyEvent::MODEL
674		833
675	Contains C<undef> until the first watcher is being created. Then it	834	Contains C<undef> until the first watcher is being created, before the
		835	backend has been autodetected.
		836
676	contains the event model that is being used, which is the name of the	837	Afterwards it contains the event model that is being used, which is the
677	Perl class implementing the model. This class is usually one of the	838	name of the Perl class implementing the model. This class is usually one
678	C<AnyEvent::Impl:xxx> modules, but can be any other class in the case	839	of the C<AnyEvent::Impl:xxx> modules, but can be any other class in the
679	AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode>).	840	case AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode> it
680		841	will be C<urxvt::anyevent>).
681	The known classes so far are:
682
683	AnyEvent::Impl::EV based on EV (an interface to libev, best choice).
684	AnyEvent::Impl::Event based on Event, second best choice.
685	AnyEvent::Impl::Perl pure-perl implementation, fast and portable.
686	AnyEvent::Impl::Glib based on Glib, third-best choice.
687	AnyEvent::Impl::Tk based on Tk, very bad choice.
688	AnyEvent::Impl::Qt based on Qt, cannot be autoprobed (see its docs).
689	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
690	AnyEvent::Impl::POE based on POE, not generic enough for full support.
691
692	There is no support for WxWidgets, as WxWidgets has no support for
693	watching file handles. However, you can use WxWidgets through the
694	POE Adaptor, as POE has a Wx backend that simply polls 20 times per
695	second, which was considered to be too horrible to even consider for
696	AnyEvent. Likewise, other POE backends can be used by AnyEvent by using
697	it's adaptor.
698
699	AnyEvent knows about L<Prima> and L<Wx> and will try to use L<POE> when
700	autodetecting them.
701		842
702	=item AnyEvent::detect	843	=item AnyEvent::detect
703		844
704	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model	845	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model
705	if necessary. You should only call this function right before you would	846	if necessary. You should only call this function right before you would
706	have created an AnyEvent watcher anyway, that is, as late as possible at	847	have created an AnyEvent watcher anyway, that is, as late as possible at
707	runtime.	848	runtime, and not e.g. while initialising of your module.
		849
		850	If you need to do some initialisation before AnyEvent watchers are
		851	created, use C<post_detect>.
708		852
709	=item $guard = AnyEvent::post_detect { BLOCK }	853	=item $guard = AnyEvent::post_detect { BLOCK }
710		854
711	Arranges for the code block to be executed as soon as the event model is	855	Arranges for the code block to be executed as soon as the event model is
712	autodetected (or immediately if this has already happened).	856	autodetected (or immediately if this has already happened).
		857
		858	The block will be executed I<after> the actual backend has been detected
		859	(C<$AnyEvent::MODEL> is set), but I<before> any watchers have been
		860	created, so it is possible to e.g. patch C<@AnyEvent::ISA> or do
		861	other initialisations - see the sources of L<AnyEvent::Strict> or
		862	L<AnyEvent::AIO> to see how this is used.
		863
		864	The most common usage is to create some global watchers, without forcing
		865	event module detection too early, for example, L<AnyEvent::AIO> creates
		866	and installs the global L<IO::AIO> watcher in a C<post_detect> block to
		867	avoid autodetecting the event module at load time.
713		868
714	If called in scalar or list context, then it creates and returns an object	869	If called in scalar or list context, then it creates and returns an object
715	that automatically removes the callback again when it is destroyed. See	870	that automatically removes the callback again when it is destroyed. See
716	L<Coro::BDB> for a case where this is useful.	871	L<Coro::BDB> for a case where this is useful.
717		872
…		…
720	If there are any code references in this array (you can C<push> to it	875	If there are any code references in this array (you can C<push> to it
721	before or after loading AnyEvent), then they will called directly after	876	before or after loading AnyEvent), then they will called directly after
722	the event loop has been chosen.	877	the event loop has been chosen.
723		878
724	You should check C<$AnyEvent::MODEL> before adding to this array, though:	879	You should check C<$AnyEvent::MODEL> before adding to this array, though:
725	if it contains a true value then the event loop has already been detected,	880	if it is defined then the event loop has already been detected, and the
726	and the array will be ignored.	881	array will be ignored.
727		882
728	Best use C<AnyEvent::post_detect { BLOCK }> instead.	883	Best use C<AnyEvent::post_detect { BLOCK }> when your application allows
		884	it,as it takes care of these details.
		885
		886	This variable is mainly useful for modules that can do something useful
		887	when AnyEvent is used and thus want to know when it is initialised, but do
		888	not need to even load it by default. This array provides the means to hook
		889	into AnyEvent passively, without loading it.
729		890
730	=back	891	=back
731		892
732	=head1 WHAT TO DO IN A MODULE	893	=head1 WHAT TO DO IN A MODULE
733		894
…		…
788		949
789		950
790	=head1 OTHER MODULES	951	=head1 OTHER MODULES
791		952
792	The following is a non-exhaustive list of additional modules that use	953	The following is a non-exhaustive list of additional modules that use
793	AnyEvent and can therefore be mixed easily with other AnyEvent modules	954	AnyEvent as a client and can therefore be mixed easily with other AnyEvent
794	in the same program. Some of the modules come with AnyEvent, some are	955	modules and other event loops in the same program. Some of the modules
795	available via CPAN.	956	come with AnyEvent, most are available via CPAN.
796		957
797	=over 4	958	=over 4
798		959
799	=item L<AnyEvent::Util>	960	=item L<AnyEvent::Util>
800		961
…		…
809		970
810	=item L<AnyEvent::Handle>	971	=item L<AnyEvent::Handle>
811		972
812	Provide read and write buffers, manages watchers for reads and writes,	973	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	974	supports raw and formatted I/O, I/O queued and fully transparent and
814	non-blocking SSL/TLS.	975	non-blocking SSL/TLS (via L<AnyEvent::TLS>.
815		976
816	=item L<AnyEvent::DNS>	977	=item L<AnyEvent::DNS>
817		978
818	Provides rich asynchronous DNS resolver capabilities.	979	Provides rich asynchronous DNS resolver capabilities.
819		980
…		…
847		1008
848	=item L<AnyEvent::GPSD>	1009	=item L<AnyEvent::GPSD>
849		1010
850	A non-blocking interface to gpsd, a daemon delivering GPS information.	1011	A non-blocking interface to gpsd, a daemon delivering GPS information.
851		1012
		1013	=item L<AnyEvent::IRC>
		1014
		1015	AnyEvent based IRC client module family (replacing the older Net::IRC3).
		1016
		1017	=item L<AnyEvent::XMPP>
		1018
		1019	AnyEvent based XMPP (Jabber protocol) module family (replacing the older
		1020	Net::XMPP2>.
		1021
852	=item L<AnyEvent::IGS>	1022	=item L<AnyEvent::IGS>
853		1023
854	A non-blocking interface to the Internet Go Server protocol (used by	1024	A non-blocking interface to the Internet Go Server protocol (used by
855	L<App::IGS>).	1025	L<App::IGS>).
856		1026
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>	1027	=item L<Net::FCP>
866		1028
867	AnyEvent-based implementation of the Freenet Client Protocol, birthplace	1029	AnyEvent-based implementation of the Freenet Client Protocol, birthplace
868	of AnyEvent.	1030	of AnyEvent.
869		1031
…		…
873		1035
874	=item L<Coro>	1036	=item L<Coro>
875		1037
876	Has special support for AnyEvent via L<Coro::AnyEvent>.	1038	Has special support for AnyEvent via L<Coro::AnyEvent>.
877		1039
878	=item L<IO::Lambda>
879
880	The lambda approach to I/O - don't ask, look there. Can use AnyEvent.
881
882	=back	1040	=back
883		1041
884	=cut	1042	=cut
885		1043
886	package AnyEvent;	1044	package AnyEvent;
887		1045
888	no warnings;	1046	no warnings;
889	use strict qw(vars subs);	1047	use strict qw(vars subs);
890		1048
891	use Carp;	1049	use Carp ();
892		1050
893	our $VERSION = 4.352;	1051	our $VERSION = 4.83;
894	our $MODEL;	1052	our $MODEL;
895		1053
896	our $AUTOLOAD;	1054	our $AUTOLOAD;
897	our @ISA;	1055	our @ISA;
898		1056
899	our @REGISTRY;	1057	our @REGISTRY;
900		1058
901	our $WIN32;	1059	our $WIN32;
902		1060
		1061	our $VERBOSE;
		1062
903	BEGIN {	1063	BEGIN {
904	my $win32 = ! ! ($^O =~ /mswin32/i);	1064	eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }";
905	eval "sub WIN32(){ $win32 }";	1065	eval "sub TAINT(){ " . (${^TAINT}*1) . " }";
906	}
907		1066
		1067	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}
		1068	if ${^TAINT};
		1069
908	our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1;	1070	$VERBOSE = $ENV{PERL_ANYEVENT_VERBOSE}*1;
		1071
		1072	}
		1073
		1074	our $MAX_SIGNAL_LATENCY = 10;
909		1075
910	our %PROTOCOL; # (ipv4\|ipv6) => (1\|2), higher numbers are preferred	1076	our %PROTOCOL; # (ipv4\|ipv6) => (1\|2), higher numbers are preferred
911		1077
912	{	1078	{
913	my $idx;	1079	my $idx;
…		…
921	[Event:: => AnyEvent::Impl::Event::],	1087	[Event:: => AnyEvent::Impl::Event::],
922	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::],	1088	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::],
923	# everything below here will not be autoprobed	1089	# everything below here will not be autoprobed
924	# as the pureperl backend should work everywhere	1090	# as the pureperl backend should work everywhere
925	# and is usually faster	1091	# and is usually faster
926	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
927	[Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers	1092	[Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers
928	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy	1093	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
		1094	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
929	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program	1095	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program
930	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza	1096	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
931	[Wx:: => AnyEvent::Impl::POE::],	1097	[Wx:: => AnyEvent::Impl::POE::],
932	[Prima:: => AnyEvent::Impl::POE::],	1098	[Prima:: => AnyEvent::Impl::POE::],
		1099	# IO::Async is just too broken - we would need workarounds for its
		1100	# byzantine signal and broken child handling, among others.
		1101	# IO::Async is rather hard to detect, as it doesn't have any
		1102	# obvious default class.
		1103	# [IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program
		1104	# [IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program
		1105	# [IO::Async::Notifier:: => AnyEvent::Impl::IOAsync::], # requires special main program
933	);	1106	);
934		1107
935	our %method = map +($_ => 1),	1108	our %method = map +($_ => 1),
936	qw(io timer time now now_update signal child condvar one_event DESTROY);	1109	qw(io timer time now now_update signal child idle condvar one_event DESTROY);
937		1110
938	our @post_detect;	1111	our @post_detect;
939		1112
940	sub post_detect(&) {	1113	sub post_detect(&) {
941	my ($cb) = @_;	1114	my ($cb) = @_;
…		…
946	1	1119	1
947	} else {	1120	} else {
948	push @post_detect, $cb;	1121	push @post_detect, $cb;
949		1122
950	defined wantarray	1123	defined wantarray
951	? bless \$cb, "AnyEvent::Util::PostDetect"	1124	? bless \$cb, "AnyEvent::Util::postdetect"
952	: ()	1125	: ()
953	}	1126	}
954	}	1127	}
955		1128
956	sub AnyEvent::Util::PostDetect::DESTROY {	1129	sub AnyEvent::Util::postdetect::DESTROY {
957	@post_detect = grep $_ != ${$_[0]}, @post_detect;	1130	@post_detect = grep $_ != ${$_[0]}, @post_detect;
958	}	1131	}
959		1132
960	sub detect() {	1133	sub detect() {
961	unless ($MODEL) {	1134	unless ($MODEL) {
…		…
964		1137
965	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {	1138	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {
966	my $model = "AnyEvent::Impl::$1";	1139	my $model = "AnyEvent::Impl::$1";
967	if (eval "require $model") {	1140	if (eval "require $model") {
968	$MODEL = $model;	1141	$MODEL = $model;
969	warn "AnyEvent: loaded model '$model' (forced by \$PERL_ANYEVENT_MODEL), using it.\n" if $verbose > 1;	1142	warn "AnyEvent: loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.\n" if $VERBOSE >= 2;
970	} else {	1143	} else {
971	warn "AnyEvent: unable to load model '$model' (from \$PERL_ANYEVENT_MODEL):\n$@" if $verbose;	1144	warn "AnyEvent: unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@" if $VERBOSE;
972	}	1145	}
973	}	1146	}
974		1147
975	# check for already loaded models	1148	# check for already loaded models
976	unless ($MODEL) {	1149	unless ($MODEL) {
977	for (@REGISTRY, @models) {	1150	for (@REGISTRY, @models) {
978	my ($package, $model) = @$_;	1151	my ($package, $model) = @$_;
979	if (${"$package\::VERSION"} > 0) {	1152	if (${"$package\::VERSION"} > 0) {
980	if (eval "require $model") {	1153	if (eval "require $model") {
981	$MODEL = $model;	1154	$MODEL = $model;
982	warn "AnyEvent: autodetected model '$model', using it.\n" if $verbose > 1;	1155	warn "AnyEvent: autodetected model '$model', using it.\n" if $VERBOSE >= 2;
983	last;	1156	last;
984	}	1157	}
985	}	1158	}
986	}	1159	}
987		1160
…		…
992	my ($package, $model) = @$_;	1165	my ($package, $model) = @$_;
993	if (eval "require $package"	1166	if (eval "require $package"
994	and ${"$package\::VERSION"} > 0	1167	and ${"$package\::VERSION"} > 0
995	and eval "require $model") {	1168	and eval "require $model") {
996	$MODEL = $model;	1169	$MODEL = $model;
997	warn "AnyEvent: autoprobed model '$model', using it.\n" if $verbose > 1;	1170	warn "AnyEvent: autoprobed model '$model', using it.\n" if $VERBOSE >= 2;
998	last;	1171	last;
999	}	1172	}
1000	}	1173	}
1001		1174
1002	$MODEL	1175	$MODEL
…		…
1018		1191
1019	sub AUTOLOAD {	1192	sub AUTOLOAD {
1020	(my $func = $AUTOLOAD) =~ s/.*://;	1193	(my $func = $AUTOLOAD) =~ s/.*://;
1021		1194
1022	$method{$func}	1195	$method{$func}
1023	or croak "$func: not a valid method for AnyEvent objects";	1196	or Carp::croak "$func: not a valid method for AnyEvent objects";
1024		1197
1025	detect unless $MODEL;	1198	detect unless $MODEL;
1026		1199
1027	my $class = shift;	1200	my $class = shift;
1028	$class->$func (@_);	1201	$class->$func (@_);
1029	}	1202	}
1030		1203
1031	# utility function to dup a filehandle. this is used by many backends	1204	# utility function to dup a filehandle. this is used by many backends
1032	# to support binding more than one watcher per filehandle (they usually	1205	# 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).	1206	# allow only one watcher per fd, so we dup it to get a different one).
1034	sub _dupfh($$$$) {	1207	sub _dupfh($$;$$) {
1035	my ($poll, $fh, $r, $w) = @_;	1208	my ($poll, $fh, $r, $w) = @_;
1036		1209
1037	# cygwin requires the fh mode to be matching, unix doesn't	1210	# cygwin requires the fh mode to be matching, unix doesn't
1038	my ($rw, $mode) = $poll eq "r" ? ($r, "<")	1211	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		1212
1042	open my $fh2, "$mode&" . fileno $fh	1213	open my $fh2, $mode, $fh
1043	or die "cannot dup() filehandle: $!,";	1214	or die "AnyEvent->io: cannot dup() filehandle in mode '$poll': $!,";
1044		1215
1045	# we assume CLOEXEC is already set by perl in all important cases	1216	# we assume CLOEXEC is already set by perl in all important cases
1046		1217
1047	($fh2, $rw)	1218	($fh2, $rw)
1048	}	1219	}
1049		1220
1050	package AnyEvent::Base;	1221	package AnyEvent::Base;
1051		1222
1052	# default implementations for many methods	1223	# default implementations for many methods
1053		1224
1054	BEGIN {	1225	sub _time {
		1226	# probe for availability of Time::HiRes
1055	if (eval "use Time::HiRes (); time (); 1") {	1227	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {
		1228	warn "AnyEvent: using Time::HiRes for sub-second timing accuracy.\n" if $VERBOSE >= 8;
1056	*_time = \&Time::HiRes::time;	1229	*_time = \&Time::HiRes::time;
1057	# if (eval "use POSIX (); (POSIX::times())...	1230	# if (eval "use POSIX (); (POSIX::times())...
1058	} else {	1231	} else {
		1232	warn "AnyEvent: using built-in time(), WARNING, no sub-second resolution!\n" if $VERBOSE;
1059	*_time = sub { time }; # epic fail	1233	*_time = sub { time }; # epic fail
1060	}	1234	}
		1235
		1236	&_time
1061	}	1237	}
1062		1238
1063	sub time { _time }	1239	sub time { _time }
1064	sub now { _time }	1240	sub now { _time }
1065	sub now_update { }	1241	sub now_update { }
1066		1242
1067	# default implementation for ->condvar	1243	# default implementation for ->condvar
1068		1244
1069	sub condvar {	1245	sub condvar {
1070	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, AnyEvent::CondVar::	1246	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"
1071	}	1247	}
1072		1248
1073	# default implementation for ->signal	1249	# default implementation for ->signal
1074		1250
		1251	our $HAVE_ASYNC_INTERRUPT;
1075	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);	1252	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);
		1253	our (%SIG_ASY, %SIG_ASY_W);
		1254	our ($SIG_COUNT, $SIG_TW);
1076		1255
1077	sub _signal_exec {	1256	sub _signal_exec {
		1257	$HAVE_ASYNC_INTERRUPT
		1258	? $SIGPIPE_R->drain
1078	sysread $SIGPIPE_R, my $dummy, 4;	1259	: sysread $SIGPIPE_R, my $dummy, 9;
1079		1260
1080	while (%SIG_EV) {	1261	while (%SIG_EV) {
1081	for (keys %SIG_EV) {	1262	for (keys %SIG_EV) {
1082	delete $SIG_EV{$_};	1263	delete $SIG_EV{$_};
1083	$_->() for values %{ $SIG_CB{$_} \|\| {} };	1264	$_->() for values %{ $SIG_CB{$_} \|\| {} };
1084	}	1265	}
1085	}	1266	}
1086	}	1267	}
1087		1268
		1269	sub _signal {
		1270	my (undef, %arg) = @_;
		1271
		1272	my $signal = uc $arg{signal}
		1273	or Carp::croak "required option 'signal' is missing";
		1274
		1275	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
		1276
		1277	if ($HAVE_ASYNC_INTERRUPT) {
		1278	# async::interrupt
		1279
		1280	$SIG_ASY{$signal} \|\|= do {
		1281	my $asy = new Async::Interrupt
		1282	cb => sub { undef $SIG_EV{$signal} },
		1283	signal => $signal,
		1284	pipe => [$SIGPIPE_R->filenos],
		1285	;
		1286	$asy->pipe_autodrain (0);
		1287
		1288	$asy
		1289	};
		1290
		1291	} else {
		1292	# pure perl
		1293
		1294	$SIG{$signal} \|\|= sub {
		1295	local $!;
		1296	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;
		1297	undef $SIG_EV{$signal};
		1298	};
		1299
		1300	# can't do signal processing without introducing races in pure perl,
		1301	# so limit the signal latency.
		1302	++$SIG_COUNT;
		1303	$SIG_TW \|\|= AnyEvent->timer (
		1304	after => $MAX_SIGNAL_LATENCY,
		1305	interval => $MAX_SIGNAL_LATENCY,
		1306	cb => sub { }, # just for the PERL_ASYNC_CHECK
		1307	);
		1308	}
		1309
		1310	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
		1311	}
		1312
1088	sub signal {	1313	sub signal {
1089	my (undef, %arg) = @_;	1314	# probe for availability of Async::Interrupt
		1315	if (!$ENV{PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT} && eval "use Async::Interrupt 0.6 (); 1") {
		1316	warn "AnyEvent: using Async::Interrupt for race-free signal handling.\n" if $VERBOSE >= 8;
1090		1317
1091	unless ($SIGPIPE_R) {	1318	$HAVE_ASYNC_INTERRUPT = 1;
		1319	$SIGPIPE_R = new Async::Interrupt::EventPipe;
		1320	$SIG_IO = AnyEvent->io (fh => $SIGPIPE_R->fileno, poll => "r", cb => \&_signal_exec);
		1321
		1322	} else {
		1323	warn "AnyEvent: using emulated perl signal handling with latency timer.\n" if $VERBOSE >= 8;
		1324
1092	require Fcntl;	1325	require Fcntl;
1093		1326
1094	if (AnyEvent::WIN32) {	1327	if (AnyEvent::WIN32) {
1095	require AnyEvent::Util;	1328	require AnyEvent::Util;
1096		1329
…		…
1099	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W) if $SIGPIPE_W; # just in case	1332	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W) if $SIGPIPE_W; # just in case
1100	} else {	1333	} else {
1101	pipe $SIGPIPE_R, $SIGPIPE_W;	1334	pipe $SIGPIPE_R, $SIGPIPE_W;
1102	fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R;	1335	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	1336	fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case
		1337
		1338	# not strictly required, as $^F is normally 2, but let's make sure...
		1339	fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
		1340	fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
1104	}	1341	}
1105		1342
1106	$SIGPIPE_R	1343	$SIGPIPE_R
1107	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";	1344	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";
1108		1345
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
1113	$SIG_IO = AnyEvent->io (fh => $SIGPIPE_R, poll => "r", cb => \&_signal_exec);	1346	$SIG_IO = AnyEvent->io (fh => $SIGPIPE_R, poll => "r", cb => \&_signal_exec);
1114	}	1347	}
1115		1348
1116	my $signal = uc $arg{signal}	1349	*signal = \&_signal;
1117	or Carp::croak "required option 'signal' is missing";	1350	&signal
1118
1119	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
1120	$SIG{$signal} \|\|= sub {
1121	local $!;
1122	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;
1123	undef $SIG_EV{$signal};
1124	};
1125
1126	bless [$signal, $arg{cb}], "AnyEvent::Base::Signal"
1127	}	1351	}
1128		1352
1129	sub AnyEvent::Base::Signal::DESTROY {	1353	sub AnyEvent::Base::signal::DESTROY {
1130	my ($signal, $cb) = @{$_[0]};	1354	my ($signal, $cb) = @{$_[0]};
1131		1355
		1356	undef $SIG_TW
		1357	unless --$SIG_COUNT;
		1358
1132	delete $SIG_CB{$signal}{$cb};	1359	delete $SIG_CB{$signal}{$cb};
1133		1360
		1361	# delete doesn't work with older perls - they then
		1362	# print weird messages, or just unconditionally exit
		1363	# instead of getting the default action.
		1364	undef $SIG{$signal}
1134	delete $SIG{$signal} unless keys %{ $SIG_CB{$signal} };	1365	unless keys %{ $SIG_CB{$signal} };
1135	}	1366	}
1136		1367
1137	# default implementation for ->child	1368	# default implementation for ->child
1138		1369
1139	our %PID_CB;	1370	our %PID_CB;
1140	our $CHLD_W;	1371	our $CHLD_W;
1141	our $CHLD_DELAY_W;	1372	our $CHLD_DELAY_W;
1142	our $PID_IDLE;
1143	our $WNOHANG;	1373	our $WNOHANG;
1144		1374
1145	sub _child_wait {	1375	sub _sigchld {
1146	while (0 < (my $pid = waitpid -1, $WNOHANG)) {	1376	while (0 < (my $pid = waitpid -1, $WNOHANG)) {
		1377	$_->($pid, $?)
1147	$_->($pid, $?) for (values %{ $PID_CB{$pid} \|\| {} }),	1378	for values %{ $PID_CB{$pid} \|\| {} },
1148	(values %{ $PID_CB{0} \|\| {} });	1379	values %{ $PID_CB{0} \|\| {} };
1149	}	1380	}
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	}	1381	}
1161		1382
1162	sub child {	1383	sub child {
1163	my (undef, %arg) = @_;	1384	my (undef, %arg) = @_;
1164		1385
1165	defined (my $pid = $arg{pid} + 0)	1386	defined (my $pid = $arg{pid} + 0)
1166	or Carp::croak "required option 'pid' is missing";	1387	or Carp::croak "required option 'pid' is missing";
1167		1388
1168	$PID_CB{$pid}{$arg{cb}} = $arg{cb};	1389	$PID_CB{$pid}{$arg{cb}} = $arg{cb};
1169		1390
1170	unless ($WNOHANG) {
1171	$WNOHANG = eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } \|\| 1;	1391	$WNOHANG \|\|= eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } \|\| 1;
1172	}
1173		1392
1174	unless ($CHLD_W) {	1393	unless ($CHLD_W) {
1175	$CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld);	1394	$CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld);
1176	# child could be a zombie already, so make at least one round	1395	# child could be a zombie already, so make at least one round
1177	&_sigchld;	1396	&_sigchld;
1178	}	1397	}
1179		1398
1180	bless [$pid, $arg{cb}], "AnyEvent::Base::Child"	1399	bless [$pid, $arg{cb}], "AnyEvent::Base::child"
1181	}	1400	}
1182		1401
1183	sub AnyEvent::Base::Child::DESTROY {	1402	sub AnyEvent::Base::child::DESTROY {
1184	my ($pid, $cb) = @{$_[0]};	1403	my ($pid, $cb) = @{$_[0]};
1185		1404
1186	delete $PID_CB{$pid}{$cb};	1405	delete $PID_CB{$pid}{$cb};
1187	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };	1406	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };
1188		1407
1189	undef $CHLD_W unless keys %PID_CB;	1408	undef $CHLD_W unless keys %PID_CB;
		1409	}
		1410
		1411	# idle emulation is done by simply using a timer, regardless
		1412	# of whether the process is idle or not, and not letting
		1413	# the callback use more than 50% of the time.
		1414	sub idle {
		1415	my (undef, %arg) = @_;
		1416
		1417	my ($cb, $w, $rcb) = $arg{cb};
		1418
		1419	$rcb = sub {
		1420	if ($cb) {
		1421	$w = _time;
		1422	&$cb;
		1423	$w = _time - $w;
		1424
		1425	# never use more then 50% of the time for the idle watcher,
		1426	# within some limits
		1427	$w = 0.0001 if $w < 0.0001;
		1428	$w = 5 if $w > 5;
		1429
		1430	$w = AnyEvent->timer (after => $w, cb => $rcb);
		1431	} else {
		1432	# clean up...
		1433	undef $w;
		1434	undef $rcb;
		1435	}
		1436	};
		1437
		1438	$w = AnyEvent->timer (after => 0.05, cb => $rcb);
		1439
		1440	bless \\$cb, "AnyEvent::Base::idle"
		1441	}
		1442
		1443	sub AnyEvent::Base::idle::DESTROY {
		1444	undef $${$_[0]};
1190	}	1445	}
1191		1446
1192	package AnyEvent::CondVar;	1447	package AnyEvent::CondVar;
1193		1448
1194	our @ISA = AnyEvent::CondVar::Base::;	1449	our @ISA = AnyEvent::CondVar::Base::;
…		…
1196	package AnyEvent::CondVar::Base;	1451	package AnyEvent::CondVar::Base;
1197		1452
1198	use overload	1453	use overload
1199	'&{}' => sub { my $self = shift; sub { $self->send (@_) } },	1454	'&{}' => sub { my $self = shift; sub { $self->send (@_) } },
1200	fallback => 1;	1455	fallback => 1;
		1456
		1457	our $WAITING;
1201		1458
1202	sub _send {	1459	sub _send {
1203	# nop	1460	# nop
1204	}	1461	}
1205		1462
…		…
1218	sub ready {	1475	sub ready {
1219	$_[0]{_ae_sent}	1476	$_[0]{_ae_sent}
1220	}	1477	}
1221		1478
1222	sub _wait {	1479	sub _wait {
		1480	$WAITING
		1481	and !$_[0]{_ae_sent}
		1482	and Carp::croak "AnyEvent::CondVar: recursive blocking wait detected";
		1483
		1484	local $WAITING = 1;
1223	AnyEvent->one_event while !$_[0]{_ae_sent};	1485	AnyEvent->one_event while !$_[0]{_ae_sent};
1224	}	1486	}
1225		1487
1226	sub recv {	1488	sub recv {
1227	$_[0]->_wait;	1489	$_[0]->_wait;
…		…
1268	so on.	1530	so on.
1269		1531
1270	=head1 ENVIRONMENT VARIABLES	1532	=head1 ENVIRONMENT VARIABLES
1271		1533
1272	The following environment variables are used by this module or its	1534	The following environment variables are used by this module or its
1273	submodules:	1535	submodules.
		1536
		1537	Note that AnyEvent will remove I<all> environment variables starting with
		1538	C<PERL_ANYEVENT_> from C<%ENV> when it is loaded while taint mode is
		1539	enabled.
1274		1540
1275	=over 4	1541	=over 4
1276		1542
1277	=item C<PERL_ANYEVENT_VERBOSE>	1543	=item C<PERL_ANYEVENT_VERBOSE>
1278		1544
…		…
1290	=item C<PERL_ANYEVENT_STRICT>	1556	=item C<PERL_ANYEVENT_STRICT>
1291		1557
1292	AnyEvent does not do much argument checking by default, as thorough	1558	AnyEvent does not do much argument checking by default, as thorough
1293	argument checking is very costly. Setting this variable to a true value	1559	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	1560	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	1561	check the arguments passed to most method calls. If it finds any problems,
1296	it will croak.	1562	it will croak.
1297		1563
1298	In other words, enables "strict" mode.	1564	In other words, enables "strict" mode.
1299		1565
1300	Unlike C<use strict>, it is definitely recommended ot keep it off in	1566	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	1567	production. Keeping C<PERL_ANYEVENT_STRICT=1> in your environment while
1302	developing programs can be very useful, however.	1568	developing programs can be very useful, however.
1303		1569
1304	=item C<PERL_ANYEVENT_MODEL>	1570	=item C<PERL_ANYEVENT_MODEL>
1305		1571
…		…
1350		1616
1351	=item C<PERL_ANYEVENT_MAX_FORKS>	1617	=item C<PERL_ANYEVENT_MAX_FORKS>
1352		1618
1353	The maximum number of child processes that C<AnyEvent::Util::fork_call>	1619	The maximum number of child processes that C<AnyEvent::Util::fork_call>
1354	will create in parallel.	1620	will create in parallel.
		1621
		1622	=item C<PERL_ANYEVENT_MAX_OUTSTANDING_DNS>
		1623
		1624	The default value for the C<max_outstanding> parameter for the default DNS
		1625	resolver - this is the maximum number of parallel DNS requests that are
		1626	sent to the DNS server.
		1627
		1628	=item C<PERL_ANYEVENT_RESOLV_CONF>
		1629
		1630	The file to use instead of F</etc/resolv.conf> (or OS-specific
		1631	configuration) in the default resolver. When set to the empty string, no
		1632	default config will be used.
		1633
		1634	=item C<PERL_ANYEVENT_CA_FILE>, C<PERL_ANYEVENT_CA_PATH>.
		1635
		1636	When neither C<ca_file> nor C<ca_path> was specified during
		1637	L<AnyEvent::TLS> context creation, and either of these environment
		1638	variables exist, they will be used to specify CA certificate locations
		1639	instead of a system-dependent default.
1355		1640
1356	=back	1641	=back
1357		1642
1358	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE	1643	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE
1359		1644
…		…
1604	EV/Any 100000 224 2.88 0.34 0.27 EV + AnyEvent watchers	1889	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	1890	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	1891	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	1892	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	1893	Event/Any 16000 590 35.85 31.55 1.06 Event + AnyEvent watchers
		1894	IOAsync/Any 16000 989 38.10 32.77 11.13 via IO::Async::Loop::IO_Poll
		1895	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	1896	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	1897	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	1898	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	1899	POE/Select 2000 6027 94.54 809.13 579.80 via POE::Loop::Select
1613		1900
…		…
1642	performance becomes really bad with lots of file descriptors (and few of	1929	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.	1930	them active), of course, but this was not subject of this benchmark.
1644		1931
1645	The C<Event> module has a relatively high setup and callback invocation	1932	The C<Event> module has a relatively high setup and callback invocation
1646	cost, but overall scores in on the third place.	1933	cost, but overall scores in on the third place.
		1934
		1935	C<IO::Async> performs admirably well, about on par with C<Event>, even
		1936	when using its pure perl backend.
1647		1937
1648	C<Glib>'s memory usage is quite a bit higher, but it features a	1938	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	1939	faster callback invocation and overall ends up in the same class as
1650	C<Event>. However, Glib scales extremely badly, doubling the number of	1940	C<Event>. However, Glib scales extremely badly, doubling the number of
1651	watchers increases the processing time by more than a factor of four,	1941	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	2019	it to another server. This includes deleting the old timeout and creating
1730	a new one that moves the timeout into the future.	2020	a new one that moves the timeout into the future.
1731		2021
1732	=head3 Results	2022	=head3 Results
1733		2023
1734	name sockets create request	2024	name sockets create request
1735	EV 20000 69.01 11.16	2025	EV 20000 69.01 11.16
1736	Perl 20000 73.32 35.87	2026	Perl 20000 73.32 35.87
		2027	IOAsync 20000 157.00 98.14 epoll
		2028	IOAsync 20000 159.31 616.06 poll
1737	Event 20000 212.62 257.32	2029	Event 20000 212.62 257.32
1738	Glib 20000 651.16 1896.30	2030	Glib 20000 651.16 1896.30
1739	POE 20000 349.67 12317.24 uses POE::Loop::Event	2031	POE 20000 349.67 12317.24 uses POE::Loop::Event
1740		2032
1741	=head3 Discussion	2033	=head3 Discussion
1742		2034
1743	This benchmark I<does> measure scalability and overall performance of the	2035	This benchmark I<does> measure scalability and overall performance of the
1744	particular event loop.	2036	particular event loop.
…		…
1746	EV is again fastest. Since it is using epoll on my system, the setup time	2038	EV is again fastest. Since it is using epoll on my system, the setup time
1747	is relatively high, though.	2039	is relatively high, though.
1748		2040
1749	Perl surprisingly comes second. It is much faster than the C-based event	2041	Perl surprisingly comes second. It is much faster than the C-based event
1750	loops Event and Glib.	2042	loops Event and Glib.
		2043
		2044	IO::Async performs very well when using its epoll backend, and still quite
		2045	good compared to Glib when using its pure perl backend.
1751		2046
1752	Event suffers from high setup time as well (look at its code and you will	2047	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	2048	understand why). Callback invocation also has a high overhead compared to
1754	the C<< $_->() for .. >>-style loop that the Perl event loop uses. Event	2049	the C<< $_->() for .. >>-style loop that the Perl event loop uses. Event
1755	uses select or poll in basically all documented configurations.	2050	uses select or poll in basically all documented configurations.
…		…
1818	=item * C-based event loops perform very well with small number of	2113	=item * C-based event loops perform very well with small number of
1819	watchers, as the management overhead dominates.	2114	watchers, as the management overhead dominates.
1820		2115
1821	=back	2116	=back
1822		2117
		2118	=head2 THE IO::Lambda BENCHMARK
		2119
		2120	Recently I was told about the benchmark in the IO::Lambda manpage, which
		2121	could be misinterpreted to make AnyEvent look bad. In fact, the benchmark
		2122	simply compares IO::Lambda with POE, and IO::Lambda looks better (which
		2123	shouldn't come as a surprise to anybody). As such, the benchmark is
		2124	fine, and mostly shows that the AnyEvent backend from IO::Lambda isn't
		2125	very optimal. But how would AnyEvent compare when used without the extra
		2126	baggage? To explore this, I wrote the equivalent benchmark for AnyEvent.
		2127
		2128	The benchmark itself creates an echo-server, and then, for 500 times,
		2129	connects to the echo server, sends a line, waits for the reply, and then
		2130	creates the next connection. This is a rather bad benchmark, as it doesn't
		2131	test the efficiency of the framework or much non-blocking I/O, but it is a
		2132	benchmark nevertheless.
		2133
		2134	name runtime
		2135	Lambda/select 0.330 sec
		2136	+ optimized 0.122 sec
		2137	Lambda/AnyEvent 0.327 sec
		2138	+ optimized 0.138 sec
		2139	Raw sockets/select 0.077 sec
		2140	POE/select, components 0.662 sec
		2141	POE/select, raw sockets 0.226 sec
		2142	POE/select, optimized 0.404 sec
		2143
		2144	AnyEvent/select/nb 0.085 sec
		2145	AnyEvent/EV/nb 0.068 sec
		2146	+state machine 0.134 sec
		2147
		2148	The benchmark is also a bit unfair (my fault): the IO::Lambda/POE
		2149	benchmarks actually make blocking connects and use 100% blocking I/O,
		2150	defeating the purpose of an event-based solution. All of the newly
		2151	written AnyEvent benchmarks use 100% non-blocking connects (using
		2152	AnyEvent::Socket::tcp_connect and the asynchronous pure perl DNS
		2153	resolver), so AnyEvent is at a disadvantage here, as non-blocking connects
		2154	generally require a lot more bookkeeping and event handling than blocking
		2155	connects (which involve a single syscall only).
		2156
		2157	The last AnyEvent benchmark additionally uses L<AnyEvent::Handle>, which
		2158	offers similar expressive power as POE and IO::Lambda, using conventional
		2159	Perl syntax. This means that both the echo server and the client are 100%
		2160	non-blocking, further placing it at a disadvantage.
		2161
		2162	As you can see, the AnyEvent + EV combination even beats the
		2163	hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl
		2164	backend easily beats IO::Lambda and POE.
		2165
		2166	And even the 100% non-blocking version written using the high-level (and
		2167	slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda by a
		2168	large margin, even though it does all of DNS, tcp-connect and socket I/O
		2169	in a non-blocking way.
		2170
		2171	The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and
		2172	F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are
		2173	part of the IO::lambda distribution and were used without any changes.
		2174
1823		2175
1824	=head1 SIGNALS	2176	=head1 SIGNALS
1825		2177
1826	AnyEvent currently installs handlers for these signals:	2178	AnyEvent currently installs handlers for these signals:
1827		2179
…		…
1830	=item SIGCHLD	2182	=item SIGCHLD
1831		2183
1832	A handler for C<SIGCHLD> is installed by AnyEvent's child watcher	2184	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	2185	emulation for event loops that do not support them natively. Also, some
1834	event loops install a similar handler.	2186	event loops install a similar handler.
		2187
		2188	Additionally, when AnyEvent is loaded and SIGCHLD is set to IGNORE, then
		2189	AnyEvent will reset it to default, to avoid losing child exit statuses.
1835		2190
1836	=item SIGPIPE	2191	=item SIGPIPE
1837		2192
1838	A no-op handler is installed for C<SIGPIPE> when C<$SIG{PIPE}> is C<undef>	2193	A no-op handler is installed for C<SIGPIPE> when C<$SIG{PIPE}> is C<undef>
1839	when AnyEvent gets loaded.	2194	when AnyEvent gets loaded.
…		…
1851		2206
1852	=back	2207	=back
1853		2208
1854	=cut	2209	=cut
1855		2210
		2211	undef $SIG{CHLD}
		2212	if $SIG{CHLD} eq 'IGNORE';
		2213
1856	$SIG{PIPE} = sub { }	2214	$SIG{PIPE} = sub { }
1857	unless defined $SIG{PIPE};	2215	unless defined $SIG{PIPE};
		2216
		2217	=head1 RECOMMENDED/OPTIONAL MODULES
		2218
		2219	One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and
		2220	it's built-in modules) are required to use it.
		2221
		2222	That does not mean that AnyEvent won't take advantage of some additional
		2223	modules if they are installed.
		2224
		2225	This section epxlains which additional modules will be used, and how they
		2226	affect AnyEvent's operetion.
		2227
		2228	=over 4
		2229
		2230	=item L<Async::Interrupt>
		2231
		2232	This slightly arcane module is used to implement fast signal handling: To
		2233	my knowledge, there is no way to do completely race-free and quick
		2234	signal handling in pure perl. To ensure that signals still get
		2235	delivered, AnyEvent will start an interval timer to wake up perl (and
		2236	catch the signals) with soemd elay (default is 10 seconds, look for
		2237	C<$AnyEvent::MAX_SIGNAL_LATENCY>).
		2238
		2239	If this module is available, then it will be used to implement signal
		2240	catching, which means that signals will not be delayed, and the event loop
		2241	will not be interrupted regularly, which is more efficient (And good for
		2242	battery life on laptops).
		2243
		2244	This affects not just the pure-perl event loop, but also other event loops
		2245	that have no signal handling on their own (e.g. Glib, Tk, Qt).
		2246
		2247	=item L<EV>
		2248
		2249	This module isn't really "optional", as it is simply one of the backend
		2250	event loops that AnyEvent can use. However, it is simply the best event
		2251	loop available in terms of features, speed and stability: It supports
		2252	the AnyEvent API optimally, implements all the watcher types in XS, does
		2253	automatic timer adjustments even when no monotonic clock is available,
		2254	can take avdantage of advanced kernel interfaces such as C<epoll> and
		2255	C<kqueue>, and is the fastest backend I<by far>. You can even embed
		2256	L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>).
		2257
		2258	=item L<Guard>
		2259
		2260	The guard module, when used, will be used to implement
		2261	C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a
		2262	lot less memory), but otherwise doesn't affect guard operation much. It is
		2263	purely used for performance.
		2264
		2265	=item L<JSON> and L<JSON::XS>
		2266
		2267	This module is required when you want to read or write JSON data via
		2268	L<AnyEvent::Handle>. It is also written in pure-perl, but can take
		2269	advantage of the ulta-high-speed L<JSON::XS> module when it is installed.
		2270
		2271	In fact, L<AnyEvent::Handle> will use L<JSON::XS> by default if it is
		2272	installed.
		2273
		2274	=item L<Net::SSLeay>
		2275
		2276	Implementing TLS/SSL in Perl is certainly interesting, but not very
		2277	worthwhile: If this module is installed, then L<AnyEvent::Handle> (with
		2278	the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL.
		2279
		2280	=item L<Time::HiRes>
		2281
		2282	This module is part of perl since release 5.008. It will be used when the
		2283	chosen event library does not come with a timing source on it's own. The
		2284	pure-perl event loop (L<AnyEvent::Impl::Perl>) will additionally use it to
		2285	try to use a monotonic clock for timing stability.
		2286
		2287	=back
1858		2288
1859		2289
1860	=head1 FORK	2290	=head1 FORK
1861		2291
1862	Most event libraries are not fork-safe. The ones who are usually are	2292	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>	2293	because they rely on inefficient but fork-safe C<select> or C<poll>
1864	calls. Only L<EV> is fully fork-aware.	2294	calls. Only L<EV> is fully fork-aware.
1865		2295
1866	If you have to fork, you must either do so I<before> creating your first	2296	If you have to fork, you must either do so I<before> creating your first
1867	watcher OR you must not use AnyEvent at all in the child.	2297	watcher OR you must not use AnyEvent at all in the child OR you must do
		2298	something completely out of the scope of AnyEvent.
1868		2299
1869		2300
1870	=head1 SECURITY CONSIDERATIONS	2301	=head1 SECURITY CONSIDERATIONS
1871		2302
1872	AnyEvent can be forced to load any event model via	2303	AnyEvent can be forced to load any event model via
…		…
1884	use AnyEvent;	2315	use AnyEvent;
1885		2316
1886	Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can	2317	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	2318	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	2319	probably even less useful to an attacker than PERL_ANYEVENT_MODEL), and
1889	$ENV{PERL_ANYEGENT_STRICT}.	2320	$ENV{PERL_ANYEVENT_STRICT}.
		2321
		2322	Note that AnyEvent will remove I<all> environment variables starting with
		2323	C<PERL_ANYEVENT_> from C<%ENV> when it is loaded while taint mode is
		2324	enabled.
1890		2325
1891		2326
1892	=head1 BUGS	2327	=head1 BUGS
1893		2328
1894	Perl 5.8 has numerous memleaks that sometimes hit this module and are hard	2329	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>.	2341	L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.
1907		2342
1908	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,	2343	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,
1909	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,	2344	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,
1910	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,	2345	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,
1911	L<AnyEvent::Impl::POE>.	2346	L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>.
1912		2347
1913	Non-blocking file handles, sockets, TCP clients and	2348	Non-blocking file handles, sockets, TCP clients and
1914	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>.	2349	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.
1915		2350
1916	Asynchronous DNS: L<AnyEvent::DNS>.	2351	Asynchronous DNS: L<AnyEvent::DNS>.
1917		2352
1918	Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>,	2353	Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>,
		2354	L<Coro::Event>,
1919		2355
1920	Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>, L<AnyEvent::DNS>.	2356	Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::XMPP>,
		2357	L<AnyEvent::HTTP>.
1921		2358
1922		2359
1923	=head1 AUTHOR	2360	=head1 AUTHOR
1924		2361
1925	Marc Lehmann <schmorp@schmorp.de>	2362	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 1.242 by root, Fri Jul 17 22:05:12 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 1.242 by root, Fri Jul 17 22:05:12 2009 UTC