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

Comparing AnyEvent/lib/AnyEvent.pm (file contents):
Revision 1.190 by root, Wed Nov 5 02:21:27 2008 UTC vs.
Revision 1.241 by root, Fri Jul 17 18:08:35 2009 UTC

…		…
1	=head1 NAME	1	=head1 NAME
2		2
3	AnyEvent - provide framework for multiple event loops	3	AnyEvent - provide framework for multiple event loops
4		4
5	EV, Event, Glib, Tk, Perl, Event::Lib, Qt, POE - various supported event loops	5	EV, Event, Glib, Tk, Perl, Event::Lib, Qt and POE are various supported
		6	event loops.
6		7
7	=head1 SYNOPSIS	8	=head1 SYNOPSIS
8		9
9	use AnyEvent;	10	use AnyEvent;
10		11
		12	# file descriptor readable
11	my $w = AnyEvent->io (fh => $fh, poll => "r\|w", cb => sub { ... });	13	my $w = AnyEvent->io (fh => $fh, poll => "r", cb => sub { ... });
12		14
		15	# one-shot or repeating timers
13	my $w = AnyEvent->timer (after => $seconds, cb => sub { ... });	16	my $w = AnyEvent->timer (after => $seconds, cb => sub { ... });
14	my $w = AnyEvent->timer (after => $seconds, interval => $seconds, cb => ...	17	my $w = AnyEvent->timer (after => $seconds, interval => $seconds, cb => ...
15		18
16	print AnyEvent->now; # prints current event loop time	19	print AnyEvent->now; # prints current event loop time
17	print AnyEvent->time; # think Time::HiRes::time or simply CORE::time.	20	print AnyEvent->time; # think Time::HiRes::time or simply CORE::time.
18		21
		22	# POSIX signal
19	my $w = AnyEvent->signal (signal => "TERM", cb => sub { ... });	23	my $w = AnyEvent->signal (signal => "TERM", cb => sub { ... });
20		24
		25	# child process exit
21	my $w = AnyEvent->child (pid => $pid, cb => sub {	26	my $w = AnyEvent->child (pid => $pid, cb => sub {
22	my ($pid, $status) = @_;	27	my ($pid, $status) = @_;
23	...	28	...
24	});	29	});
		30
		31	# called when event loop idle (if applicable)
		32	my $w = AnyEvent->idle (cb => sub { ... });
25		33
26	my $w = AnyEvent->condvar; # stores whether a condition was flagged	34	my $w = AnyEvent->condvar; # stores whether a condition was flagged
27	$w->send; # wake up current and all future recv's	35	$w->send; # wake up current and all future recv's
28	$w->recv; # enters "main loop" till $condvar gets ->send	36	$w->recv; # enters "main loop" till $condvar gets ->send
29	# use a condvar in callback mode:	37	# use a condvar in callback mode:
137	These watchers are normal Perl objects with normal Perl lifetime. After	145	These watchers are normal Perl objects with normal Perl lifetime. After
138	creating a watcher it will immediately "watch" for events and invoke the	146	creating a watcher it will immediately "watch" for events and invoke the
139	callback when the event occurs (of course, only when the event model	147	callback when the event occurs (of course, only when the event model
140	is in control).	148	is in control).
141		149
		150	Note that B<callbacks must not permanently change global variables>
		151	potentially in use by the event loop (such as C<$_> or C<$[>) and that B<<
		152	callbacks must not C<die> >>. The former is good programming practise in
		153	Perl and the latter stems from the fact that exception handling differs
		154	widely between event loops.
		155
142	To disable the watcher you have to destroy it (e.g. by setting the	156	To disable the watcher you have to destroy it (e.g. by setting the
143	variable you store it in to C<undef> or otherwise deleting all references	157	variable you store it in to C<undef> or otherwise deleting all references
144	to it).	158	to it).
145		159
146	All watchers are created by calling a method on the C<AnyEvent> class.	160	All watchers are created by calling a method on the C<AnyEvent> class.
…		…
162	=head2 I/O WATCHERS	176	=head2 I/O WATCHERS
163		177
164	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
165	with the following mandatory key-value pairs as arguments:	179	with the following mandatory key-value pairs as arguments:
166		180
167	C<fh> the Perl I<file handle> (I<not> file descriptor) to watch for events	181	C<fh> is the Perl I<file handle> (or a naked file descriptor) to watch
168	(AnyEvent might or might not keep a reference to this file handle). C<poll>	182	for events (AnyEvent might or might not keep a reference to this file
		183	handle). Note that only file handles pointing to things for which
		184	non-blocking operation makes sense are allowed. This includes sockets,
		185	most character devices, pipes, fifos and so on, but not for example files
		186	or block devices.
		187
169	must be a string that is either C<r> or C<w>, which creates a watcher	188	C<poll> must be a string that is either C<r> or C<w>, which creates a
170	waiting for "r"eadable or "w"ritable events, respectively. C<cb> is the	189	watcher waiting for "r"eadable or "w"ritable events, respectively.
		190
171	callback to invoke each time the file handle becomes ready.	191	C<cb> is the callback to invoke each time the file handle becomes ready.
172		192
173	Although the callback might get passed parameters, their value and	193	Although the callback might get passed parameters, their value and
174	presence is undefined and you cannot rely on them. Portable AnyEvent	194	presence is undefined and you cannot rely on them. Portable AnyEvent
175	callbacks cannot use arguments passed to I/O watcher callbacks.	195	callbacks cannot use arguments passed to I/O watcher callbacks.
176		196
…		…
308	In either case, if you care (and in most cases, you don't), then you	328	In either case, if you care (and in most cases, you don't), then you
309	can get whatever behaviour you want with any event loop, by taking the	329	can get whatever behaviour you want with any event loop, by taking the
310	difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into	330	difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into
311	account.	331	account.
312		332
		333	=item AnyEvent->now_update
		334
		335	Some event loops (such as L<EV> or L<AnyEvent::Impl::Perl>) cache
		336	the current time for each loop iteration (see the discussion of L<<
		337	AnyEvent->now >>, above).
		338
		339	When a callback runs for a long time (or when the process sleeps), then
		340	this "current" time will differ substantially from the real time, which
		341	might affect timers and time-outs.
		342
		343	When this is the case, you can call this method, which will update the
		344	event loop's idea of "current time".
		345
		346	Note that updating the time I<might> cause some events to be handled.
		347
313	=back	348	=back
314		349
315	=head2 SIGNAL WATCHERS	350	=head2 SIGNAL WATCHERS
316		351
317	You can watch for signals using a signal watcher, C<signal> is the signal	352	You can watch for signals using a signal watcher, C<signal> is the signal
…		…
357		392
358	There is a slight catch to child watchers, however: you usually start them	393	There is a slight catch to child watchers, however: you usually start them
359	I<after> the child process was created, and this means the process could	394	I<after> the child process was created, and this means the process could
360	have exited already (and no SIGCHLD will be sent anymore).	395	have exited already (and no SIGCHLD will be sent anymore).
361		396
362	Not all event models handle this correctly (POE doesn't), but even for	397	Not all event models handle this correctly (neither POE nor IO::Async do,
		398	see their AnyEvent::Impl manpages for details), but even for event models
363	event models that I<do> handle this correctly, they usually need to be	399	that I<do> handle this correctly, they usually need to be loaded before
364	loaded before the process exits (i.e. before you fork in the first place).	400	the process exits (i.e. before you fork in the first place). AnyEvent's
		401	pure perl event loop handles all cases correctly regardless of when you
		402	start the watcher.
365		403
366	This means you cannot create a child watcher as the very first thing in an	404	This means you cannot create a child watcher as the very first
367	AnyEvent program, you I<have> to create at least one watcher before you	405	thing in an AnyEvent program, you I<have> to create at least one
368	C<fork> the child (alternatively, you can call C<AnyEvent::detect>).	406	watcher before you C<fork> the child (alternatively, you can call
		407	C<AnyEvent::detect>).
369		408
370	Example: fork a process and wait for it	409	Example: fork a process and wait for it
371		410
372	my $done = AnyEvent->condvar;	411	my $done = AnyEvent->condvar;
373		412
…		…
383	);	422	);
384		423
385	# do something else, then wait for process exit	424	# do something else, then wait for process exit
386	$done->recv;	425	$done->recv;
387		426
		427	=head2 IDLE WATCHERS
		428
		429	Sometimes there is a need to do something, but it is not so important
		430	to do it instantly, but only when there is nothing better to do. This
		431	"nothing better to do" is usually defined to be "no other events need
		432	attention by the event loop".
		433
		434	Idle watchers ideally get invoked when the event loop has nothing
		435	better to do, just before it would block the process to wait for new
		436	events. Instead of blocking, the idle watcher is invoked.
		437
		438	Most event loops unfortunately do not really support idle watchers (only
		439	EV, Event and Glib do it in a usable fashion) - for the rest, AnyEvent
		440	will simply call the callback "from time to time".
		441
		442	Example: read lines from STDIN, but only process them when the
		443	program is otherwise idle:
		444
		445	my @lines; # read data
		446	my $idle_w;
		447	my $io_w = AnyEvent->io (fh => \*STDIN, poll => 'r', cb => sub {
		448	push @lines, scalar <STDIN>;
		449
		450	# start an idle watcher, if not already done
		451	$idle_w \|\|= AnyEvent->idle (cb => sub {
		452	# handle only one line, when there are lines left
		453	if (my $line = shift @lines) {
		454	print "handled when idle: $line";
		455	} else {
		456	# otherwise disable the idle watcher again
		457	undef $idle_w;
		458	}
		459	});
		460	});
		461
388	=head2 CONDITION VARIABLES	462	=head2 CONDITION VARIABLES
389		463
390	If you are familiar with some event loops you will know that all of them	464	If you are familiar with some event loops you will know that all of them
391	require you to run some blocking "loop", "run" or similar function that	465	require you to run some blocking "loop", "run" or similar function that
392	will actively watch for new events and call your callbacks.	466	will actively watch for new events and call your callbacks.
393		467
394	AnyEvent is different, it expects somebody else to run the event loop and	468	AnyEvent is slightly different: it expects somebody else to run the event
395	will only block when necessary (usually when told by the user).	469	loop and will only block when necessary (usually when told by the user).
396		470
397	The instrument to do that is called a "condition variable", so called	471	The instrument to do that is called a "condition variable", so called
398	because they represent a condition that must become true.	472	because they represent a condition that must become true.
399		473
		474	Now is probably a good time to look at the examples further below.
		475
400	Condition variables can be created by calling the C<< AnyEvent->condvar	476	Condition variables can be created by calling the C<< AnyEvent->condvar
401	>> method, usually without arguments. The only argument pair allowed is	477	>> method, usually without arguments. The only argument pair allowed is
402
403	C<cb>, which specifies a callback to be called when the condition variable	478	C<cb>, which specifies a callback to be called when the condition variable
404	becomes true, with the condition variable as the first argument (but not	479	becomes true, with the condition variable as the first argument (but not
405	the results).	480	the results).
406		481
407	After creation, the condition variable is "false" until it becomes "true"	482	After creation, the condition variable is "false" until it becomes "true"
…		…
456	after => 1,	531	after => 1,
457	cb => sub { $result_ready->send },	532	cb => sub { $result_ready->send },
458	);	533	);
459		534
460	# this "blocks" (while handling events) till the callback	535	# this "blocks" (while handling events) till the callback
461	# calls send	536	# calls -<send
462	$result_ready->recv;	537	$result_ready->recv;
463		538
464	Example: wait for a timer, but take advantage of the fact that	539	Example: wait for a timer, but take advantage of the fact that condition
465	condition variables are also code references.	540	variables are also callable directly.
466		541
467	my $done = AnyEvent->condvar;	542	my $done = AnyEvent->condvar;
468	my $delay = AnyEvent->timer (after => 5, cb => $done);	543	my $delay = AnyEvent->timer (after => 5, cb => $done);
469	$done->recv;	544	$done->recv;
470		545
…		…
476		551
477	...	552	...
478		553
479	my @info = $couchdb->info->recv;	554	my @info = $couchdb->info->recv;
480		555
481	And this is how you would just ste a callback to be called whenever the	556	And this is how you would just set a callback to be called whenever the
482	results are available:	557	results are available:
483		558
484	$couchdb->info->cb (sub {	559	$couchdb->info->cb (sub {
485	my @info = $_[0]->recv;	560	my @info = $_[0]->recv;
486	});	561	});
…		…
504	immediately from within send.	579	immediately from within send.
505		580
506	Any arguments passed to the C<send> call will be returned by all	581	Any arguments passed to the C<send> call will be returned by all
507	future C<< ->recv >> calls.	582	future C<< ->recv >> calls.
508		583
509	Condition variables are overloaded so one can call them directly	584	Condition variables are overloaded so one can call them directly (as if
510	(as a code reference). Calling them directly is the same as calling	585	they were a code reference). Calling them directly is the same as calling
511	C<send>. Note, however, that many C-based event loops do not handle	586	C<send>.
512	overloading, so as tempting as it may be, passing a condition variable
513	instead of a callback does not work. Both the pure perl and EV loops
514	support overloading, however, as well as all functions that use perl to
515	invoke a callback (as in L<AnyEvent::Socket> and L<AnyEvent::DNS> for
516	example).
517		587
518	=item $cv->croak ($error)	588	=item $cv->croak ($error)
519		589
520	Similar to send, but causes all call's to C<< ->recv >> to invoke	590	Similar to send, but causes all call's to C<< ->recv >> to invoke
521	C<Carp::croak> with the given error message/object/scalar.	591	C<Carp::croak> with the given error message/object/scalar.
522		592
523	This can be used to signal any errors to the condition variable	593	This can be used to signal any errors to the condition variable
524	user/consumer.	594	user/consumer. Doing it this way instead of calling C<croak> directly
		595	delays the error detetcion, but has the overwhelmign advantage that it
		596	diagnoses the error at the place where the result is expected, and not
		597	deep in some event clalback without connection to the actual code causing
		598	the problem.
525		599
526	=item $cv->begin ([group callback])	600	=item $cv->begin ([group callback])
527		601
528	=item $cv->end	602	=item $cv->end
529
530	These two methods are EXPERIMENTAL and MIGHT CHANGE.
531		603
532	These two methods can be used to combine many transactions/events into	604	These two methods can be used to combine many transactions/events into
533	one. For example, a function that pings many hosts in parallel might want	605	one. For example, a function that pings many hosts in parallel might want
534	to use a condition variable for the whole process.	606	to use a condition variable for the whole process.
535		607
…		…
537	C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end	609	C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end
538	>>, the (last) callback passed to C<begin> will be executed. That callback	610	>>, the (last) callback passed to C<begin> will be executed. That callback
539	is I<supposed> to call C<< ->send >>, but that is not required. If no	611	is I<supposed> to call C<< ->send >>, but that is not required. If no
540	callback was set, C<send> will be called without any arguments.	612	callback was set, C<send> will be called without any arguments.
541		613
542	Let's clarify this with the ping example:	614	You can think of C<< $cv->send >> giving you an OR condition (one call
		615	sends), while C<< $cv->begin >> and C<< $cv->end >> giving you an AND
		616	condition (all C<begin> calls must be C<end>'ed before the condvar sends).
		617
		618	Let's start with a simple example: you have two I/O watchers (for example,
		619	STDOUT and STDERR for a program), and you want to wait for both streams to
		620	close before activating a condvar:
		621
		622	my $cv = AnyEvent->condvar;
		623
		624	$cv->begin; # first watcher
		625	my $w1 = AnyEvent->io (fh => $fh1, cb => sub {
		626	defined sysread $fh1, my $buf, 4096
		627	or $cv->end;
		628	});
		629
		630	$cv->begin; # second watcher
		631	my $w2 = AnyEvent->io (fh => $fh2, cb => sub {
		632	defined sysread $fh2, my $buf, 4096
		633	or $cv->end;
		634	});
		635
		636	$cv->recv;
		637
		638	This works because for every event source (EOF on file handle), there is
		639	one call to C<begin>, so the condvar waits for all calls to C<end> before
		640	sending.
		641
		642	The ping example mentioned above is slightly more complicated, as the
		643	there are results to be passwd back, and the number of tasks that are
		644	begung can potentially be zero:
543		645
544	my $cv = AnyEvent->condvar;	646	my $cv = AnyEvent->condvar;
545		647
546	my %result;	648	my %result;
547	$cv->begin (sub { $cv->send (\%result) });	649	$cv->begin (sub { $cv->send (\%result) });
…		…
567	loop, which serves two important purposes: first, it sets the callback	669	loop, which serves two important purposes: first, it sets the callback
568	to be called once the counter reaches C<0>, and second, it ensures that	670	to be called once the counter reaches C<0>, and second, it ensures that
569	C<send> is called even when C<no> hosts are being pinged (the loop	671	C<send> is called even when C<no> hosts are being pinged (the loop
570	doesn't execute once).	672	doesn't execute once).
571		673
572	This is the general pattern when you "fan out" into multiple subrequests:	674	This is the general pattern when you "fan out" into multiple (but
573	use an outer C<begin>/C<end> pair to set the callback and ensure C<end>	675	potentially none) subrequests: use an outer C<begin>/C<end> pair to set
574	is called at least once, and then, for each subrequest you start, call	676	the callback and ensure C<end> is called at least once, and then, for each
575	C<begin> and for each subrequest you finish, call C<end>.	677	subrequest you start, call C<begin> and for each subrequest you finish,
		678	call C<end>.
576		679
577	=back	680	=back
578		681
579	=head3 METHODS FOR CONSUMERS	682	=head3 METHODS FOR CONSUMERS
580		683
…		…
596	function will call C<croak>.	699	function will call C<croak>.
597		700
598	In list context, all parameters passed to C<send> will be returned,	701	In list context, all parameters passed to C<send> will be returned,
599	in scalar context only the first one will be returned.	702	in scalar context only the first one will be returned.
600		703
		704	Note that doing a blocking wait in a callback is not supported by any
		705	event loop, that is, recursive invocation of a blocking C<< ->recv
		706	>> is not allowed, and the C<recv> call will C<croak> if such a
		707	condition is detected. This condition can be slightly loosened by using
		708	L<Coro::AnyEvent>, which allows you to do a blocking C<< ->recv >> from
		709	any thread that doesn't run the event loop itself.
		710
601	Not all event models support a blocking wait - some die in that case	711	Not all event models support a blocking wait - some die in that case
602	(programs might want to do that to stay interactive), so I<if you are	712	(programs might want to do that to stay interactive), so I<if you are
603	using this from a module, never require a blocking wait>, but let the	713	using this from a module, never require a blocking wait>. Instead, let the
604	caller decide whether the call will block or not (for example, by coupling	714	caller decide whether the call will block or not (for example, by coupling
605	condition variables with some kind of request results and supporting	715	condition variables with some kind of request results and supporting
606	callbacks so the caller knows that getting the result will not block,	716	callbacks so the caller knows that getting the result will not block,
607	while still supporting blocking waits if the caller so desires).	717	while still supporting blocking waits if the caller so desires).
608		718
609	Another reason I<never> to C<< ->recv >> in a module is that you cannot
610	sensibly have two C<< ->recv >>'s in parallel, as that would require
611	multiple interpreters or coroutines/threads, none of which C<AnyEvent>
612	can supply.
613
614	The L<Coro> module, however, I<can> and I<does> supply coroutines and, in
615	fact, L<Coro::AnyEvent> replaces AnyEvent's condvars by coroutine-safe
616	versions and also integrates coroutines into AnyEvent, making blocking
617	C<< ->recv >> calls perfectly safe as long as they are done from another
618	coroutine (one that doesn't run the event loop).
619
620	You can ensure that C<< -recv >> never blocks by setting a callback and	719	You can ensure that C<< -recv >> never blocks by setting a callback and
621	only calling C<< ->recv >> from within that callback (or at a later	720	only calling C<< ->recv >> from within that callback (or at a later
622	time). This will work even when the event loop does not support blocking	721	time). This will work even when the event loop does not support blocking
623	waits otherwise.	722	waits otherwise.
624		723
…		…
637	variable itself. Calling C<recv> inside the callback or at any later time	736	variable itself. Calling C<recv> inside the callback or at any later time
638	is guaranteed not to block.	737	is guaranteed not to block.
639		738
640	=back	739	=back
641		740
		741	=head1 SUPPORTED EVENT LOOPS/BACKENDS
		742
		743	The available backend classes are (every class has its own manpage):
		744
		745	=over 4
		746
		747	=item Backends that are autoprobed when no other event loop can be found.
		748
		749	EV is the preferred backend when no other event loop seems to be in
		750	use. If EV is not installed, then AnyEvent will try Event, and, failing
		751	that, will fall back to its own pure-perl implementation, which is
		752	available everywhere as it comes with AnyEvent itself.
		753
		754	AnyEvent::Impl::EV based on EV (interface to libev, best choice).
		755	AnyEvent::Impl::Event based on Event, very stable, few glitches.
		756	AnyEvent::Impl::Perl pure-perl implementation, fast and portable.
		757
		758	=item Backends that are transparently being picked up when they are used.
		759
		760	These will be used when they are currently loaded when the first watcher
		761	is created, in which case it is assumed that the application is using
		762	them. This means that AnyEvent will automatically pick the right backend
		763	when the main program loads an event module before anything starts to
		764	create watchers. Nothing special needs to be done by the main program.
		765
		766	AnyEvent::Impl::Glib based on Glib, slow but very stable.
		767	AnyEvent::Impl::Tk based on Tk, very broken.
		768	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
		769	AnyEvent::Impl::POE based on POE, very slow, some limitations.
		770
		771	=item Backends with special needs.
		772
		773	Qt requires the Qt::Application to be instantiated first, but will
		774	otherwise be picked up automatically. As long as the main program
		775	instantiates the application before any AnyEvent watchers are created,
		776	everything should just work.
		777
		778	AnyEvent::Impl::Qt based on Qt.
		779
		780	Support for IO::Async can only be partial, as it is too broken and
		781	architecturally limited to even support the AnyEvent API. It also
		782	is the only event loop that needs the loop to be set explicitly, so
		783	it can only be used by a main program knowing about AnyEvent. See
		784	L<AnyEvent::Impl::Async> for the gory details.
		785
		786	AnyEvent::Impl::IOAsync based on IO::Async, cannot be autoprobed.
		787
		788	=item Event loops that are indirectly supported via other backends.
		789
		790	Some event loops can be supported via other modules:
		791
		792	There is no direct support for WxWidgets (L<Wx>) or L<Prima>.
		793
		794	B<WxWidgets> has no support for watching file handles. However, you can
		795	use WxWidgets through the POE adaptor, as POE has a Wx backend that simply
		796	polls 20 times per second, which was considered to be too horrible to even
		797	consider for AnyEvent.
		798
		799	B<Prima> is not supported as nobody seems to be using it, but it has a POE
		800	backend, so it can be supported through POE.
		801
		802	AnyEvent knows about both L<Prima> and L<Wx>, however, and will try to
		803	load L<POE> when detecting them, in the hope that POE will pick them up,
		804	in which case everything will be automatic.
		805
		806	=back
		807
642	=head1 GLOBAL VARIABLES AND FUNCTIONS	808	=head1 GLOBAL VARIABLES AND FUNCTIONS
643		809
		810	These are not normally required to use AnyEvent, but can be useful to
		811	write AnyEvent extension modules.
		812
644	=over 4	813	=over 4
645		814
646	=item $AnyEvent::MODEL	815	=item $AnyEvent::MODEL
647		816
648	Contains C<undef> until the first watcher is being created. Then it	817	Contains C<undef> until the first watcher is being created, before the
		818	backend has been autodetected.
		819
649	contains the event model that is being used, which is the name of the	820	Afterwards it contains the event model that is being used, which is the
650	Perl class implementing the model. This class is usually one of the	821	name of the Perl class implementing the model. This class is usually one
651	C<AnyEvent::Impl:xxx> modules, but can be any other class in the case	822	of the C<AnyEvent::Impl:xxx> modules, but can be any other class in the
652	AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode>).	823	case AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode> it
653		824	will be C<urxvt::anyevent>).
654	The known classes so far are:
655
656	AnyEvent::Impl::EV based on EV (an interface to libev, best choice).
657	AnyEvent::Impl::Event based on Event, second best choice.
658	AnyEvent::Impl::Perl pure-perl implementation, fast and portable.
659	AnyEvent::Impl::Glib based on Glib, third-best choice.
660	AnyEvent::Impl::Tk based on Tk, very bad choice.
661	AnyEvent::Impl::Qt based on Qt, cannot be autoprobed (see its docs).
662	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
663	AnyEvent::Impl::POE based on POE, not generic enough for full support.
664
665	There is no support for WxWidgets, as WxWidgets has no support for
666	watching file handles. However, you can use WxWidgets through the
667	POE Adaptor, as POE has a Wx backend that simply polls 20 times per
668	second, which was considered to be too horrible to even consider for
669	AnyEvent. Likewise, other POE backends can be used by AnyEvent by using
670	it's adaptor.
671
672	AnyEvent knows about L<Prima> and L<Wx> and will try to use L<POE> when
673	autodetecting them.
674		825
675	=item AnyEvent::detect	826	=item AnyEvent::detect
676		827
677	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model	828	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model
678	if necessary. You should only call this function right before you would	829	if necessary. You should only call this function right before you would
679	have created an AnyEvent watcher anyway, that is, as late as possible at	830	have created an AnyEvent watcher anyway, that is, as late as possible at
680	runtime.	831	runtime, and not e.g. while initialising of your module.
		832
		833	If you need to do some initialisation before AnyEvent watchers are
		834	created, use C<post_detect>.
681		835
682	=item $guard = AnyEvent::post_detect { BLOCK }	836	=item $guard = AnyEvent::post_detect { BLOCK }
683		837
684	Arranges for the code block to be executed as soon as the event model is	838	Arranges for the code block to be executed as soon as the event model is
685	autodetected (or immediately if this has already happened).	839	autodetected (or immediately if this has already happened).
		840
		841	The block will be executed I<after> the actual backend has been detected
		842	(C<$AnyEvent::MODEL> is set), but I<before> any watchers have been
		843	created, so it is possible to e.g. patch C<@AnyEvent::ISA> or do
		844	other initialisations - see the sources of L<AnyEvent::Strict> or
		845	L<AnyEvent::AIO> to see how this is used.
		846
		847	The most common usage is to create some global watchers, without forcing
		848	event module detection too early, for example, L<AnyEvent::AIO> creates
		849	and installs the global L<IO::AIO> watcher in a C<post_detect> block to
		850	avoid autodetecting the event module at load time.
686		851
687	If called in scalar or list context, then it creates and returns an object	852	If called in scalar or list context, then it creates and returns an object
688	that automatically removes the callback again when it is destroyed. See	853	that automatically removes the callback again when it is destroyed. See
689	L<Coro::BDB> for a case where this is useful.	854	L<Coro::BDB> for a case where this is useful.
690		855
…		…
693	If there are any code references in this array (you can C<push> to it	858	If there are any code references in this array (you can C<push> to it
694	before or after loading AnyEvent), then they will called directly after	859	before or after loading AnyEvent), then they will called directly after
695	the event loop has been chosen.	860	the event loop has been chosen.
696		861
697	You should check C<$AnyEvent::MODEL> before adding to this array, though:	862	You should check C<$AnyEvent::MODEL> before adding to this array, though:
698	if it contains a true value then the event loop has already been detected,	863	if it is defined then the event loop has already been detected, and the
699	and the array will be ignored.	864	array will be ignored.
700		865
701	Best use C<AnyEvent::post_detect { BLOCK }> instead.	866	Best use C<AnyEvent::post_detect { BLOCK }> when your application allows
		867	it,as it takes care of these details.
		868
		869	This variable is mainly useful for modules that can do something useful
		870	when AnyEvent is used and thus want to know when it is initialised, but do
		871	not need to even load it by default. This array provides the means to hook
		872	into AnyEvent passively, without loading it.
702		873
703	=back	874	=back
704		875
705	=head1 WHAT TO DO IN A MODULE	876	=head1 WHAT TO DO IN A MODULE
706		877
…		…
761		932
762		933
763	=head1 OTHER MODULES	934	=head1 OTHER MODULES
764		935
765	The following is a non-exhaustive list of additional modules that use	936	The following is a non-exhaustive list of additional modules that use
766	AnyEvent and can therefore be mixed easily with other AnyEvent modules	937	AnyEvent as a client and can therefore be mixed easily with other AnyEvent
767	in the same program. Some of the modules come with AnyEvent, some are	938	modules and other event loops in the same program. Some of the modules
768	available via CPAN.	939	come with AnyEvent, most are available via CPAN.
769		940
770	=over 4	941	=over 4
771		942
772	=item L<AnyEvent::Util>	943	=item L<AnyEvent::Util>
773		944
…		…
782		953
783	=item L<AnyEvent::Handle>	954	=item L<AnyEvent::Handle>
784		955
785	Provide read and write buffers, manages watchers for reads and writes,	956	Provide read and write buffers, manages watchers for reads and writes,
786	supports raw and formatted I/O, I/O queued and fully transparent and	957	supports raw and formatted I/O, I/O queued and fully transparent and
787	non-blocking SSL/TLS.	958	non-blocking SSL/TLS (via L<AnyEvent::TLS>.
788		959
789	=item L<AnyEvent::DNS>	960	=item L<AnyEvent::DNS>
790		961
791	Provides rich asynchronous DNS resolver capabilities.	962	Provides rich asynchronous DNS resolver capabilities.
792		963
…		…
820		991
821	=item L<AnyEvent::GPSD>	992	=item L<AnyEvent::GPSD>
822		993
823	A non-blocking interface to gpsd, a daemon delivering GPS information.	994	A non-blocking interface to gpsd, a daemon delivering GPS information.
824		995
		996	=item L<AnyEvent::IRC>
		997
		998	AnyEvent based IRC client module family (replacing the older Net::IRC3).
		999
		1000	=item L<AnyEvent::XMPP>
		1001
		1002	AnyEvent based XMPP (Jabber protocol) module family (replacing the older
		1003	Net::XMPP2>.
		1004
825	=item L<AnyEvent::IGS>	1005	=item L<AnyEvent::IGS>
826		1006
827	A non-blocking interface to the Internet Go Server protocol (used by	1007	A non-blocking interface to the Internet Go Server protocol (used by
828	L<App::IGS>).	1008	L<App::IGS>).
829		1009
830	=item L<AnyEvent::IRC>
831
832	AnyEvent based IRC client module family (replacing the older Net::IRC3).
833
834	=item L<Net::XMPP2>
835
836	AnyEvent based XMPP (Jabber protocol) module family.
837
838	=item L<Net::FCP>	1010	=item L<Net::FCP>
839		1011
840	AnyEvent-based implementation of the Freenet Client Protocol, birthplace	1012	AnyEvent-based implementation of the Freenet Client Protocol, birthplace
841	of AnyEvent.	1013	of AnyEvent.
842		1014
…		…
846		1018
847	=item L<Coro>	1019	=item L<Coro>
848		1020
849	Has special support for AnyEvent via L<Coro::AnyEvent>.	1021	Has special support for AnyEvent via L<Coro::AnyEvent>.
850		1022
851	=item L<IO::Lambda>
852
853	The lambda approach to I/O - don't ask, look there. Can use AnyEvent.
854
855	=back	1023	=back
856		1024
857	=cut	1025	=cut
858		1026
859	package AnyEvent;	1027	package AnyEvent;
860		1028
861	no warnings;	1029	no warnings;
862	use strict qw(vars subs);	1030	use strict qw(vars subs);
863		1031
864	use Carp;	1032	use Carp ();
865		1033
866	our $VERSION = 4.32;	1034	our $VERSION = 4.83;
867	our $MODEL;	1035	our $MODEL;
868		1036
869	our $AUTOLOAD;	1037	our $AUTOLOAD;
870	our @ISA;	1038	our @ISA;
871		1039
872	our @REGISTRY;	1040	our @REGISTRY;
873		1041
874	our $WIN32;	1042	our $WIN32;
875		1043
876	BEGIN {	1044	BEGIN {
877	my $win32 = ! ! ($^O =~ /mswin32/i);	1045	eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }";
878	eval "sub WIN32(){ $win32 }";	1046	eval "sub TAINT(){ " . (${^TAINT}*1) . " }";
		1047
		1048	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}
		1049	if ${^TAINT};
879	}	1050	}
880		1051
881	our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1;	1052	our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1;
882		1053
883	our %PROTOCOL; # (ipv4\|ipv6) => (1\|2), higher numbers are preferred	1054	our %PROTOCOL; # (ipv4\|ipv6) => (1\|2), higher numbers are preferred
…		…
894	[Event:: => AnyEvent::Impl::Event::],	1065	[Event:: => AnyEvent::Impl::Event::],
895	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::],	1066	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::],
896	# everything below here will not be autoprobed	1067	# everything below here will not be autoprobed
897	# as the pureperl backend should work everywhere	1068	# as the pureperl backend should work everywhere
898	# and is usually faster	1069	# and is usually faster
899	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
900	[Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers	1070	[Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers
901	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy	1071	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
		1072	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
902	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program	1073	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program
903	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza	1074	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
904	[Wx:: => AnyEvent::Impl::POE::],	1075	[Wx:: => AnyEvent::Impl::POE::],
905	[Prima:: => AnyEvent::Impl::POE::],	1076	[Prima:: => AnyEvent::Impl::POE::],
		1077	# IO::Async is just too broken - we would need workarounds for its
		1078	# byzantine signal and broken child handling, among others.
		1079	# IO::Async is rather hard to detect, as it doesn't have any
		1080	# obvious default class.
		1081	# [IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program
		1082	# [IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program
		1083	# [IO::Async::Notifier:: => AnyEvent::Impl::IOAsync::], # requires special main program
906	);	1084	);
907		1085
908	our %method = map +($_ => 1), qw(io timer time now signal child condvar one_event DESTROY);	1086	our %method = map +($_ => 1),
		1087	qw(io timer time now now_update signal child idle condvar one_event DESTROY);
909		1088
910	our @post_detect;	1089	our @post_detect;
911		1090
912	sub post_detect(&) {	1091	sub post_detect(&) {
913	my ($cb) = @_;	1092	my ($cb) = @_;
…		…
918	1	1097	1
919	} else {	1098	} else {
920	push @post_detect, $cb;	1099	push @post_detect, $cb;
921		1100
922	defined wantarray	1101	defined wantarray
923	? bless \$cb, "AnyEvent::Util::PostDetect"	1102	? bless \$cb, "AnyEvent::Util::postdetect"
924	: ()	1103	: ()
925	}	1104	}
926	}	1105	}
927		1106
928	sub AnyEvent::Util::PostDetect::DESTROY {	1107	sub AnyEvent::Util::postdetect::DESTROY {
929	@post_detect = grep $_ != ${$_[0]}, @post_detect;	1108	@post_detect = grep $_ != ${$_[0]}, @post_detect;
930	}	1109	}
931		1110
932	sub detect() {	1111	sub detect() {
933	unless ($MODEL) {	1112	unless ($MODEL) {
…		…
936		1115
937	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {	1116	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {
938	my $model = "AnyEvent::Impl::$1";	1117	my $model = "AnyEvent::Impl::$1";
939	if (eval "require $model") {	1118	if (eval "require $model") {
940	$MODEL = $model;	1119	$MODEL = $model;
941	warn "AnyEvent: loaded model '$model' (forced by \$PERL_ANYEVENT_MODEL), using it.\n" if $verbose > 1;	1120	warn "AnyEvent: loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.\n" if $verbose > 1;
942	} else {	1121	} else {
943	warn "AnyEvent: unable to load model '$model' (from \$PERL_ANYEVENT_MODEL):\n$@" if $verbose;	1122	warn "AnyEvent: unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@" if $verbose;
944	}	1123	}
945	}	1124	}
946		1125
947	# check for already loaded models	1126	# check for already loaded models
948	unless ($MODEL) {	1127	unless ($MODEL) {
…		…
970	last;	1149	last;
971	}	1150	}
972	}	1151	}
973		1152
974	$MODEL	1153	$MODEL
975	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.";	1154	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.\n";
976	}	1155	}
977	}	1156	}
978		1157
979	push @{"$MODEL\::ISA"}, "AnyEvent::Base";	1158	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
980		1159
…		…
990		1169
991	sub AUTOLOAD {	1170	sub AUTOLOAD {
992	(my $func = $AUTOLOAD) =~ s/.*://;	1171	(my $func = $AUTOLOAD) =~ s/.*://;
993		1172
994	$method{$func}	1173	$method{$func}
995	or croak "$func: not a valid method for AnyEvent objects";	1174	or Carp::croak "$func: not a valid method for AnyEvent objects";
996		1175
997	detect unless $MODEL;	1176	detect unless $MODEL;
998		1177
999	my $class = shift;	1178	my $class = shift;
1000	$class->$func (@_);	1179	$class->$func (@_);
1001	}	1180	}
1002		1181
1003	# utility function to dup a filehandle. this is used by many backends	1182	# utility function to dup a filehandle. this is used by many backends
1004	# to support binding more than one watcher per filehandle (they usually	1183	# to support binding more than one watcher per filehandle (they usually
1005	# allow only one watcher per fd, so we dup it to get a different one).	1184	# allow only one watcher per fd, so we dup it to get a different one).
1006	sub _dupfh($$$$) {	1185	sub _dupfh($$;$$) {
1007	my ($poll, $fh, $r, $w) = @_;	1186	my ($poll, $fh, $r, $w) = @_;
1008		1187
1009	require Fcntl;
1010
1011	# cygwin requires the fh mode to be matching, unix doesn't	1188	# cygwin requires the fh mode to be matching, unix doesn't
1012	my ($rw, $mode) = $poll eq "r" ? ($r, "<")	1189	my ($rw, $mode) = $poll eq "r" ? ($r, "<&") : ($w, ">&");
1013	: $poll eq "w" ? ($w, ">")
1014	: Carp::croak "AnyEvent->io requires poll set to either 'r' or 'w'";
1015		1190
1016	open my $fh2, "$mode&" . fileno $fh	1191	open my $fh2, $mode, $fh
1017	or die "cannot dup() filehandle: $!";	1192	or die "AnyEvent->io: cannot dup() filehandle in mode '$poll': $!,";
1018		1193
1019	# we assume CLOEXEC is already set by perl in all important cases	1194	# we assume CLOEXEC is already set by perl in all important cases
1020		1195
1021	($fh2, $rw)	1196	($fh2, $rw)
1022	}	1197	}
1023		1198
1024	package AnyEvent::Base;	1199	package AnyEvent::Base;
1025		1200
1026	# default implementation for now and time	1201	# default implementations for many methods
1027		1202
1028	BEGIN {	1203	BEGIN {
1029	if (eval "use Time::HiRes (); time (); 1") {	1204	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {
1030	*_time = \&Time::HiRes::time;	1205	*_time = \&Time::HiRes::time;
1031	# if (eval "use POSIX (); (POSIX::times())...	1206	# if (eval "use POSIX (); (POSIX::times())...
1032	} else {	1207	} else {
1033	*_time = sub { time }; # epic fail	1208	*_time = sub { time }; # epic fail
1034	}	1209	}
1035	}	1210	}
1036		1211
1037	sub time { _time }	1212	sub time { _time }
1038	sub now { _time }	1213	sub now { _time }
		1214	sub now_update { }
1039		1215
1040	# default implementation for ->condvar	1216	# default implementation for ->condvar
1041		1217
1042	sub condvar {	1218	sub condvar {
1043	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, AnyEvent::CondVar::	1219	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"
1044	}	1220	}
1045		1221
1046	# default implementation for ->signal	1222	# default implementation for ->signal
1047		1223
1048	our %SIG_CB;	1224	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);
		1225
		1226	sub _signal_exec {
		1227	sysread $SIGPIPE_R, my $dummy, 4;
		1228
		1229	while (%SIG_EV) {
		1230	for (keys %SIG_EV) {
		1231	delete $SIG_EV{$_};
		1232	$_->() for values %{ $SIG_CB{$_} \|\| {} };
		1233	}
		1234	}
		1235	}
1049		1236
1050	sub signal {	1237	sub signal {
1051	my (undef, %arg) = @_;	1238	my (undef, %arg) = @_;
1052		1239
		1240	unless ($SIGPIPE_R) {
		1241	require Fcntl;
		1242
		1243	if (AnyEvent::WIN32) {
		1244	require AnyEvent::Util;
		1245
		1246	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
		1247	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R) if $SIGPIPE_R;
		1248	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W) if $SIGPIPE_W; # just in case
		1249	} else {
		1250	pipe $SIGPIPE_R, $SIGPIPE_W;
		1251	fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R;
		1252	fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case
		1253
		1254	# not strictly required, as $^F is normally 2, but let's make sure...
		1255	fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
		1256	fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
		1257	}
		1258
		1259	$SIGPIPE_R
		1260	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";
		1261
		1262	$SIG_IO = AnyEvent->io (fh => $SIGPIPE_R, poll => "r", cb => \&_signal_exec);
		1263	}
		1264
1053	my $signal = uc $arg{signal}	1265	my $signal = uc $arg{signal}
1054	or Carp::croak "required option 'signal' is missing";	1266	or Carp::croak "required option 'signal' is missing";
1055		1267
1056	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};	1268	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
1057	$SIG{$signal} \|\|= sub {	1269	$SIG{$signal} \|\|= sub {
1058	$_->() for values %{ $SIG_CB{$signal} \|\| {} };	1270	local $!;
		1271	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;
		1272	undef $SIG_EV{$signal};
1059	};	1273	};
1060		1274
1061	bless [$signal, $arg{cb}], "AnyEvent::Base::Signal"	1275	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
1062	}	1276	}
1063		1277
1064	sub AnyEvent::Base::Signal::DESTROY {	1278	sub AnyEvent::Base::signal::DESTROY {
1065	my ($signal, $cb) = @{$_[0]};	1279	my ($signal, $cb) = @{$_[0]};
1066		1280
1067	delete $SIG_CB{$signal}{$cb};	1281	delete $SIG_CB{$signal}{$cb};
1068		1282
		1283	# delete doesn't work with older perls - they then
		1284	# print weird messages, or just unconditionally exit
		1285	# instead of getting the default action.
1069	delete $SIG{$signal} unless keys %{ $SIG_CB{$signal} };	1286	undef $SIG{$signal} unless keys %{ $SIG_CB{$signal} };
1070	}	1287	}
1071		1288
1072	# default implementation for ->child	1289	# default implementation for ->child
1073		1290
1074	our %PID_CB;	1291	our %PID_CB;
1075	our $CHLD_W;	1292	our $CHLD_W;
1076	our $CHLD_DELAY_W;	1293	our $CHLD_DELAY_W;
1077	our $PID_IDLE;
1078	our $WNOHANG;	1294	our $WNOHANG;
1079		1295
1080	sub _child_wait {	1296	sub _sigchld {
1081	while (0 < (my $pid = waitpid -1, $WNOHANG)) {	1297	while (0 < (my $pid = waitpid -1, $WNOHANG)) {
1082	$_->($pid, $?) for (values %{ $PID_CB{$pid} \|\| {} }),	1298	$_->($pid, $?) for (values %{ $PID_CB{$pid} \|\| {} }),
1083	(values %{ $PID_CB{0} \|\| {} });	1299	(values %{ $PID_CB{0} \|\| {} });
1084	}	1300	}
1085
1086	undef $PID_IDLE;
1087	}
1088
1089	sub _sigchld {
1090	# make sure we deliver these changes "synchronous" with the event loop.
1091	$CHLD_DELAY_W \|\|= AnyEvent->timer (after => 0, cb => sub {
1092	undef $CHLD_DELAY_W;
1093	&_child_wait;
1094	});
1095	}	1301	}
1096		1302
1097	sub child {	1303	sub child {
1098	my (undef, %arg) = @_;	1304	my (undef, %arg) = @_;
1099		1305
1100	defined (my $pid = $arg{pid} + 0)	1306	defined (my $pid = $arg{pid} + 0)
1101	or Carp::croak "required option 'pid' is missing";	1307	or Carp::croak "required option 'pid' is missing";
1102		1308
1103	$PID_CB{$pid}{$arg{cb}} = $arg{cb};	1309	$PID_CB{$pid}{$arg{cb}} = $arg{cb};
1104		1310
1105	unless ($WNOHANG) {
1106	$WNOHANG = eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } \|\| 1;	1311	$WNOHANG \|\|= eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } \|\| 1;
1107	}
1108		1312
1109	unless ($CHLD_W) {	1313	unless ($CHLD_W) {
1110	$CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld);	1314	$CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld);
1111	# child could be a zombie already, so make at least one round	1315	# child could be a zombie already, so make at least one round
1112	&_sigchld;	1316	&_sigchld;
1113	}	1317	}
1114		1318
1115	bless [$pid, $arg{cb}], "AnyEvent::Base::Child"	1319	bless [$pid, $arg{cb}], "AnyEvent::Base::child"
1116	}	1320	}
1117		1321
1118	sub AnyEvent::Base::Child::DESTROY {	1322	sub AnyEvent::Base::child::DESTROY {
1119	my ($pid, $cb) = @{$_[0]};	1323	my ($pid, $cb) = @{$_[0]};
1120		1324
1121	delete $PID_CB{$pid}{$cb};	1325	delete $PID_CB{$pid}{$cb};
1122	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };	1326	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };
1123		1327
1124	undef $CHLD_W unless keys %PID_CB;	1328	undef $CHLD_W unless keys %PID_CB;
		1329	}
		1330
		1331	# idle emulation is done by simply using a timer, regardless
		1332	# of whether the process is idle or not, and not letting
		1333	# the callback use more than 50% of the time.
		1334	sub idle {
		1335	my (undef, %arg) = @_;
		1336
		1337	my ($cb, $w, $rcb) = $arg{cb};
		1338
		1339	$rcb = sub {
		1340	if ($cb) {
		1341	$w = _time;
		1342	&$cb;
		1343	$w = _time - $w;
		1344
		1345	# never use more then 50% of the time for the idle watcher,
		1346	# within some limits
		1347	$w = 0.0001 if $w < 0.0001;
		1348	$w = 5 if $w > 5;
		1349
		1350	$w = AnyEvent->timer (after => $w, cb => $rcb);
		1351	} else {
		1352	# clean up...
		1353	undef $w;
		1354	undef $rcb;
		1355	}
		1356	};
		1357
		1358	$w = AnyEvent->timer (after => 0.05, cb => $rcb);
		1359
		1360	bless \\$cb, "AnyEvent::Base::idle"
		1361	}
		1362
		1363	sub AnyEvent::Base::idle::DESTROY {
		1364	undef $${$_[0]};
1125	}	1365	}
1126		1366
1127	package AnyEvent::CondVar;	1367	package AnyEvent::CondVar;
1128		1368
1129	our @ISA = AnyEvent::CondVar::Base::;	1369	our @ISA = AnyEvent::CondVar::Base::;
…		…
1131	package AnyEvent::CondVar::Base;	1371	package AnyEvent::CondVar::Base;
1132		1372
1133	use overload	1373	use overload
1134	'&{}' => sub { my $self = shift; sub { $self->send (@_) } },	1374	'&{}' => sub { my $self = shift; sub { $self->send (@_) } },
1135	fallback => 1;	1375	fallback => 1;
		1376
		1377	our $WAITING;
1136		1378
1137	sub _send {	1379	sub _send {
1138	# nop	1380	# nop
1139	}	1381	}
1140		1382
…		…
1153	sub ready {	1395	sub ready {
1154	$_[0]{_ae_sent}	1396	$_[0]{_ae_sent}
1155	}	1397	}
1156		1398
1157	sub _wait {	1399	sub _wait {
		1400	$WAITING
		1401	and !$_[0]{_ae_sent}
		1402	and Carp::croak "AnyEvent::CondVar: recursive blocking wait detected";
		1403
		1404	local $WAITING = 1;
1158	AnyEvent->one_event while !$_[0]{_ae_sent};	1405	AnyEvent->one_event while !$_[0]{_ae_sent};
1159	}	1406	}
1160		1407
1161	sub recv {	1408	sub recv {
1162	$_[0]->_wait;	1409	$_[0]->_wait;
…		…
1203	so on.	1450	so on.
1204		1451
1205	=head1 ENVIRONMENT VARIABLES	1452	=head1 ENVIRONMENT VARIABLES
1206		1453
1207	The following environment variables are used by this module or its	1454	The following environment variables are used by this module or its
1208	submodules:	1455	submodules.
		1456
		1457	Note that AnyEvent will remove I<all> environment variables starting with
		1458	C<PERL_ANYEVENT_> from C<%ENV> when it is loaded while taint mode is
		1459	enabled.
1209		1460
1210	=over 4	1461	=over 4
1211		1462
1212	=item C<PERL_ANYEVENT_VERBOSE>	1463	=item C<PERL_ANYEVENT_VERBOSE>
1213		1464
…		…
1225	=item C<PERL_ANYEVENT_STRICT>	1476	=item C<PERL_ANYEVENT_STRICT>
1226		1477
1227	AnyEvent does not do much argument checking by default, as thorough	1478	AnyEvent does not do much argument checking by default, as thorough
1228	argument checking is very costly. Setting this variable to a true value	1479	argument checking is very costly. Setting this variable to a true value
1229	will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly	1480	will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly
1230	check the arguments passed to most method calls. If it finds any problems	1481	check the arguments passed to most method calls. If it finds any problems,
1231	it will croak.	1482	it will croak.
1232		1483
1233	In other words, enables "strict" mode.	1484	In other words, enables "strict" mode.
1234		1485
1235	Unlike C<use strict>, it is definitely recommended ot keep it off in	1486	Unlike C<use strict>, it is definitely recommended to keep it off in
1236	production. Keeping C<PERL_ANYEVENT_STRICT=1> in your environment while	1487	production. Keeping C<PERL_ANYEVENT_STRICT=1> in your environment while
1237	developing programs can be very useful, however.	1488	developing programs can be very useful, however.
1238		1489
1239	=item C<PERL_ANYEVENT_MODEL>	1490	=item C<PERL_ANYEVENT_MODEL>
1240		1491
…		…
1263	used, and preference will be given to protocols mentioned earlier in the	1514	used, and preference will be given to protocols mentioned earlier in the
1264	list.	1515	list.
1265		1516
1266	This variable can effectively be used for denial-of-service attacks	1517	This variable can effectively be used for denial-of-service attacks
1267	against local programs (e.g. when setuid), although the impact is likely	1518	against local programs (e.g. when setuid), although the impact is likely
1268	small, as the program has to handle connection errors already-	1519	small, as the program has to handle conenction and other failures anyways.
1269		1520
1270	Examples: C<PERL_ANYEVENT_PROTOCOLS=ipv4,ipv6> - prefer IPv4 over IPv6,	1521	Examples: C<PERL_ANYEVENT_PROTOCOLS=ipv4,ipv6> - prefer IPv4 over IPv6,
1271	but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4>	1522	but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4>
1272	- only support IPv4, never try to resolve or contact IPv6	1523	- only support IPv4, never try to resolve or contact IPv6
1273	addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or	1524	addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or
…		…
1285		1536
1286	=item C<PERL_ANYEVENT_MAX_FORKS>	1537	=item C<PERL_ANYEVENT_MAX_FORKS>
1287		1538
1288	The maximum number of child processes that C<AnyEvent::Util::fork_call>	1539	The maximum number of child processes that C<AnyEvent::Util::fork_call>
1289	will create in parallel.	1540	will create in parallel.
		1541
		1542	=item C<PERL_ANYEVENT_MAX_OUTSTANDING_DNS>
		1543
		1544	The default value for the C<max_outstanding> parameter for the default DNS
		1545	resolver - this is the maximum number of parallel DNS requests that are
		1546	sent to the DNS server.
		1547
		1548	=item C<PERL_ANYEVENT_RESOLV_CONF>
		1549
		1550	The file to use instead of F</etc/resolv.conf> (or OS-specific
		1551	configuration) in the default resolver. When set to the empty string, no
		1552	default config will be used.
		1553
		1554	=item C<PERL_ANYEVENT_CA_FILE>, C<PERL_ANYEVENT_CA_PATH>.
		1555
		1556	When neither C<ca_file> nor C<ca_path> was specified during
		1557	L<AnyEvent::TLS> context creation, and either of these environment
		1558	variables exist, they will be used to specify CA certificate locations
		1559	instead of a system-dependent default.
1290		1560
1291	=back	1561	=back
1292		1562
1293	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE	1563	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE
1294		1564
…		…
1539	EV/Any 100000 224 2.88 0.34 0.27 EV + AnyEvent watchers	1809	EV/Any 100000 224 2.88 0.34 0.27 EV + AnyEvent watchers
1540	CoroEV/Any 100000 224 2.85 0.35 0.28 coroutines + Coro::Signal	1810	CoroEV/Any 100000 224 2.85 0.35 0.28 coroutines + Coro::Signal
1541	Perl/Any 100000 452 4.13 0.73 0.95 pure perl implementation	1811	Perl/Any 100000 452 4.13 0.73 0.95 pure perl implementation
1542	Event/Event 16000 517 32.20 31.80 0.81 Event native interface	1812	Event/Event 16000 517 32.20 31.80 0.81 Event native interface
1543	Event/Any 16000 590 35.85 31.55 1.06 Event + AnyEvent watchers	1813	Event/Any 16000 590 35.85 31.55 1.06 Event + AnyEvent watchers
		1814	IOAsync/Any 16000 989 38.10 32.77 11.13 via IO::Async::Loop::IO_Poll
		1815	IOAsync/Any 16000 990 37.59 29.50 10.61 via IO::Async::Loop::Epoll
1544	Glib/Any 16000 1357 102.33 12.31 51.00 quadratic behaviour	1816	Glib/Any 16000 1357 102.33 12.31 51.00 quadratic behaviour
1545	Tk/Any 2000 1860 27.20 66.31 14.00 SEGV with >> 2000 watchers	1817	Tk/Any 2000 1860 27.20 66.31 14.00 SEGV with >> 2000 watchers
1546	POE/Event 2000 6328 109.99 751.67 14.02 via POE::Loop::Event	1818	POE/Event 2000 6328 109.99 751.67 14.02 via POE::Loop::Event
1547	POE/Select 2000 6027 94.54 809.13 579.80 via POE::Loop::Select	1819	POE/Select 2000 6027 94.54 809.13 579.80 via POE::Loop::Select
1548		1820
…		…
1577	performance becomes really bad with lots of file descriptors (and few of	1849	performance becomes really bad with lots of file descriptors (and few of
1578	them active), of course, but this was not subject of this benchmark.	1850	them active), of course, but this was not subject of this benchmark.
1579		1851
1580	The C<Event> module has a relatively high setup and callback invocation	1852	The C<Event> module has a relatively high setup and callback invocation
1581	cost, but overall scores in on the third place.	1853	cost, but overall scores in on the third place.
		1854
		1855	C<IO::Async> performs admirably well, about on par with C<Event>, even
		1856	when using its pure perl backend.
1582		1857
1583	C<Glib>'s memory usage is quite a bit higher, but it features a	1858	C<Glib>'s memory usage is quite a bit higher, but it features a
1584	faster callback invocation and overall ends up in the same class as	1859	faster callback invocation and overall ends up in the same class as
1585	C<Event>. However, Glib scales extremely badly, doubling the number of	1860	C<Event>. However, Glib scales extremely badly, doubling the number of
1586	watchers increases the processing time by more than a factor of four,	1861	watchers increases the processing time by more than a factor of four,
…		…
1664	it to another server. This includes deleting the old timeout and creating	1939	it to another server. This includes deleting the old timeout and creating
1665	a new one that moves the timeout into the future.	1940	a new one that moves the timeout into the future.
1666		1941
1667	=head3 Results	1942	=head3 Results
1668		1943
1669	name sockets create request	1944	name sockets create request
1670	EV 20000 69.01 11.16	1945	EV 20000 69.01 11.16
1671	Perl 20000 73.32 35.87	1946	Perl 20000 73.32 35.87
		1947	IOAsync 20000 157.00 98.14 epoll
		1948	IOAsync 20000 159.31 616.06 poll
1672	Event 20000 212.62 257.32	1949	Event 20000 212.62 257.32
1673	Glib 20000 651.16 1896.30	1950	Glib 20000 651.16 1896.30
1674	POE 20000 349.67 12317.24 uses POE::Loop::Event	1951	POE 20000 349.67 12317.24 uses POE::Loop::Event
1675		1952
1676	=head3 Discussion	1953	=head3 Discussion
1677		1954
1678	This benchmark I<does> measure scalability and overall performance of the	1955	This benchmark I<does> measure scalability and overall performance of the
1679	particular event loop.	1956	particular event loop.
…		…
1681	EV is again fastest. Since it is using epoll on my system, the setup time	1958	EV is again fastest. Since it is using epoll on my system, the setup time
1682	is relatively high, though.	1959	is relatively high, though.
1683		1960
1684	Perl surprisingly comes second. It is much faster than the C-based event	1961	Perl surprisingly comes second. It is much faster than the C-based event
1685	loops Event and Glib.	1962	loops Event and Glib.
		1963
		1964	IO::Async performs very well when using its epoll backend, and still quite
		1965	good compared to Glib when using its pure perl backend.
1686		1966
1687	Event suffers from high setup time as well (look at its code and you will	1967	Event suffers from high setup time as well (look at its code and you will
1688	understand why). Callback invocation also has a high overhead compared to	1968	understand why). Callback invocation also has a high overhead compared to
1689	the C<< $_->() for .. >>-style loop that the Perl event loop uses. Event	1969	the C<< $_->() for .. >>-style loop that the Perl event loop uses. Event
1690	uses select or poll in basically all documented configurations.	1970	uses select or poll in basically all documented configurations.
…		…
1753	=item * C-based event loops perform very well with small number of	2033	=item * C-based event loops perform very well with small number of
1754	watchers, as the management overhead dominates.	2034	watchers, as the management overhead dominates.
1755		2035
1756	=back	2036	=back
1757		2037
		2038	=head2 THE IO::Lambda BENCHMARK
		2039
		2040	Recently I was told about the benchmark in the IO::Lambda manpage, which
		2041	could be misinterpreted to make AnyEvent look bad. In fact, the benchmark
		2042	simply compares IO::Lambda with POE, and IO::Lambda looks better (which
		2043	shouldn't come as a surprise to anybody). As such, the benchmark is
		2044	fine, and mostly shows that the AnyEvent backend from IO::Lambda isn't
		2045	very optimal. But how would AnyEvent compare when used without the extra
		2046	baggage? To explore this, I wrote the equivalent benchmark for AnyEvent.
		2047
		2048	The benchmark itself creates an echo-server, and then, for 500 times,
		2049	connects to the echo server, sends a line, waits for the reply, and then
		2050	creates the next connection. This is a rather bad benchmark, as it doesn't
		2051	test the efficiency of the framework or much non-blocking I/O, but it is a
		2052	benchmark nevertheless.
		2053
		2054	name runtime
		2055	Lambda/select 0.330 sec
		2056	+ optimized 0.122 sec
		2057	Lambda/AnyEvent 0.327 sec
		2058	+ optimized 0.138 sec
		2059	Raw sockets/select 0.077 sec
		2060	POE/select, components 0.662 sec
		2061	POE/select, raw sockets 0.226 sec
		2062	POE/select, optimized 0.404 sec
		2063
		2064	AnyEvent/select/nb 0.085 sec
		2065	AnyEvent/EV/nb 0.068 sec
		2066	+state machine 0.134 sec
		2067
		2068	The benchmark is also a bit unfair (my fault): the IO::Lambda/POE
		2069	benchmarks actually make blocking connects and use 100% blocking I/O,
		2070	defeating the purpose of an event-based solution. All of the newly
		2071	written AnyEvent benchmarks use 100% non-blocking connects (using
		2072	AnyEvent::Socket::tcp_connect and the asynchronous pure perl DNS
		2073	resolver), so AnyEvent is at a disadvantage here, as non-blocking connects
		2074	generally require a lot more bookkeeping and event handling than blocking
		2075	connects (which involve a single syscall only).
		2076
		2077	The last AnyEvent benchmark additionally uses L<AnyEvent::Handle>, which
		2078	offers similar expressive power as POE and IO::Lambda, using conventional
		2079	Perl syntax. This means that both the echo server and the client are 100%
		2080	non-blocking, further placing it at a disadvantage.
		2081
		2082	As you can see, the AnyEvent + EV combination even beats the
		2083	hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl
		2084	backend easily beats IO::Lambda and POE.
		2085
		2086	And even the 100% non-blocking version written using the high-level (and
		2087	slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda by a
		2088	large margin, even though it does all of DNS, tcp-connect and socket I/O
		2089	in a non-blocking way.
		2090
		2091	The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and
		2092	F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are
		2093	part of the IO::lambda distribution and were used without any changes.
		2094
1758		2095
1759	=head1 SIGNALS	2096	=head1 SIGNALS
1760		2097
1761	AnyEvent currently installs handlers for these signals:	2098	AnyEvent currently installs handlers for these signals:
1762		2099
…		…
1765	=item SIGCHLD	2102	=item SIGCHLD
1766		2103
1767	A handler for C<SIGCHLD> is installed by AnyEvent's child watcher	2104	A handler for C<SIGCHLD> is installed by AnyEvent's child watcher
1768	emulation for event loops that do not support them natively. Also, some	2105	emulation for event loops that do not support them natively. Also, some
1769	event loops install a similar handler.	2106	event loops install a similar handler.
		2107
		2108	Additionally, when AnyEvent is loaded and SIGCHLD is set to IGNORE, then
		2109	AnyEvent will reset it to default, to avoid losing child exit statuses.
1770		2110
1771	=item SIGPIPE	2111	=item SIGPIPE
1772		2112
1773	A no-op handler is installed for C<SIGPIPE> when C<$SIG{PIPE}> is C<undef>	2113	A no-op handler is installed for C<SIGPIPE> when C<$SIG{PIPE}> is C<undef>
1774	when AnyEvent gets loaded.	2114	when AnyEvent gets loaded.
…		…
1786		2126
1787	=back	2127	=back
1788		2128
1789	=cut	2129	=cut
1790		2130
		2131	undef $SIG{CHLD}
		2132	if $SIG{CHLD} eq 'IGNORE';
		2133
1791	$SIG{PIPE} = sub { }	2134	$SIG{PIPE} = sub { }
1792	unless defined $SIG{PIPE};	2135	unless defined $SIG{PIPE};
1793
1794		2136
1795	=head1 FORK	2137	=head1 FORK
1796		2138
1797	Most event libraries are not fork-safe. The ones who are usually are	2139	Most event libraries are not fork-safe. The ones who are usually are
1798	because they rely on inefficient but fork-safe C<select> or C<poll>	2140	because they rely on inefficient but fork-safe C<select> or C<poll>
…		…
1819	use AnyEvent;	2161	use AnyEvent;
1820		2162
1821	Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can	2163	Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can
1822	be used to probe what backend is used and gain other information (which is	2164	be used to probe what backend is used and gain other information (which is
1823	probably even less useful to an attacker than PERL_ANYEVENT_MODEL), and	2165	probably even less useful to an attacker than PERL_ANYEVENT_MODEL), and
1824	$ENV{PERL_ANYEGENT_STRICT}.	2166	$ENV{PERL_ANYEVENT_STRICT}.
		2167
		2168	Note that AnyEvent will remove I<all> environment variables starting with
		2169	C<PERL_ANYEVENT_> from C<%ENV> when it is loaded while taint mode is
		2170	enabled.
1825		2171
1826		2172
1827	=head1 BUGS	2173	=head1 BUGS
1828		2174
1829	Perl 5.8 has numerous memleaks that sometimes hit this module and are hard	2175	Perl 5.8 has numerous memleaks that sometimes hit this module and are hard
1830	to work around. If you suffer from memleaks, first upgrade to Perl 5.10	2176	to work around. If you suffer from memleaks, first upgrade to Perl 5.10
1831	and check wether the leaks still show up. (Perl 5.10.0 has other annoying	2177	and check wether the leaks still show up. (Perl 5.10.0 has other annoying
1832	mamleaks, such as leaking on C<map> and C<grep> but it is usually not as	2178	memleaks, such as leaking on C<map> and C<grep> but it is usually not as
1833	pronounced).	2179	pronounced).
1834		2180
1835		2181
1836	=head1 SEE ALSO	2182	=head1 SEE ALSO
1837		2183
…		…
1841	L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.	2187	L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.
1842		2188
1843	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,	2189	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,
1844	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,	2190	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,
1845	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,	2191	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,
1846	L<AnyEvent::Impl::POE>.	2192	L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>.
1847		2193
1848	Non-blocking file handles, sockets, TCP clients and	2194	Non-blocking file handles, sockets, TCP clients and
1849	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>.	2195	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.
1850		2196
1851	Asynchronous DNS: L<AnyEvent::DNS>.	2197	Asynchronous DNS: L<AnyEvent::DNS>.
1852		2198
1853	Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>,	2199	Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>,
		2200	L<Coro::Event>,
1854		2201
1855	Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>, L<AnyEvent::DNS>.	2202	Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::XMPP>,
		2203	L<AnyEvent::HTTP>.
1856		2204
1857		2205
1858	=head1 AUTHOR	2206	=head1 AUTHOR
1859		2207
1860	Marc Lehmann <schmorp@schmorp.de>	2208	Marc Lehmann <schmorp@schmorp.de>

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Comparing AnyEvent/lib/AnyEvent.pm (file contents): Revision 1.190 by root, Wed Nov 5 02:21:27 2008 UTC vs. Revision 1.241 by root, Fri Jul 17 18:08:35 2009 UTC

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Comparing AnyEvent/lib/AnyEvent.pm (file contents):
Revision 1.190 by root, Wed Nov 5 02:21:27 2008 UTC vs.
Revision 1.241 by root, Fri Jul 17 18:08:35 2009 UTC