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

Comparing AnyEvent/lib/AnyEvent.pm (file contents):
Revision 1.198 by root, Thu Mar 26 20:17:44 2009 UTC vs.
Revision 1.241 by root, Fri Jul 17 18:08:35 2009 UTC

…		…
1	=head1 NAME	1	=head1 NAME
2		2
3	AnyEvent - provide framework for multiple event loops	3	AnyEvent - provide framework for multiple event loops
4		4
5	EV, Event, Glib, Tk, Perl, Event::Lib, Qt, POE - various supported event loops	5	EV, Event, Glib, Tk, Perl, Event::Lib, Qt and POE are various supported
		6	event loops.
6		7
7	=head1 SYNOPSIS	8	=head1 SYNOPSIS
8		9
9	use AnyEvent;	10	use AnyEvent;
10		11
		12	# file descriptor readable
11	my $w = AnyEvent->io (fh => $fh, poll => "r\|w", cb => sub { ... });	13	my $w = AnyEvent->io (fh => $fh, poll => "r", cb => sub { ... });
12		14
		15	# one-shot or repeating timers
13	my $w = AnyEvent->timer (after => $seconds, cb => sub { ... });	16	my $w = AnyEvent->timer (after => $seconds, cb => sub { ... });
14	my $w = AnyEvent->timer (after => $seconds, interval => $seconds, cb => ...	17	my $w = AnyEvent->timer (after => $seconds, interval => $seconds, cb => ...
15		18
16	print AnyEvent->now; # prints current event loop time	19	print AnyEvent->now; # prints current event loop time
17	print AnyEvent->time; # think Time::HiRes::time or simply CORE::time.	20	print AnyEvent->time; # think Time::HiRes::time or simply CORE::time.
18		21
		22	# POSIX signal
19	my $w = AnyEvent->signal (signal => "TERM", cb => sub { ... });	23	my $w = AnyEvent->signal (signal => "TERM", cb => sub { ... });
20		24
		25	# child process exit
21	my $w = AnyEvent->child (pid => $pid, cb => sub {	26	my $w = AnyEvent->child (pid => $pid, cb => sub {
22	my ($pid, $status) = @_;	27	my ($pid, $status) = @_;
23	...	28	...
24	});	29	});
		30
		31	# called when event loop idle (if applicable)
		32	my $w = AnyEvent->idle (cb => sub { ... });
25		33
26	my $w = AnyEvent->condvar; # stores whether a condition was flagged	34	my $w = AnyEvent->condvar; # stores whether a condition was flagged
27	$w->send; # wake up current and all future recv's	35	$w->send; # wake up current and all future recv's
28	$w->recv; # enters "main loop" till $condvar gets ->send	36	$w->recv; # enters "main loop" till $condvar gets ->send
29	# use a condvar in callback mode:	37	# use a condvar in callback mode:
168	=head2 I/O WATCHERS	176	=head2 I/O WATCHERS
169		177
170	You can create an I/O watcher by calling the C<< AnyEvent->io >> method	178	You can create an I/O watcher by calling the C<< AnyEvent->io >> method
171	with the following mandatory key-value pairs as arguments:	179	with the following mandatory key-value pairs as arguments:
172		180
173	C<fh> 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
174	(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
175	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
176	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
177	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.
178		192
179	Although the callback might get passed parameters, their value and	193	Although the callback might get passed parameters, their value and
180	presence is undefined and you cannot rely on them. Portable AnyEvent	194	presence is undefined and you cannot rely on them. Portable AnyEvent
181	callbacks cannot use arguments passed to I/O watcher callbacks.	195	callbacks cannot use arguments passed to I/O watcher callbacks.
182		196
…		…
314	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
315	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
316	difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into	330	difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into
317	account.	331	account.
318		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
319	=back	348	=back
320		349
321	=head2 SIGNAL WATCHERS	350	=head2 SIGNAL WATCHERS
322		351
323	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
…		…
363		392
364	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
365	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
366	have exited already (and no SIGCHLD will be sent anymore).	395	have exited already (and no SIGCHLD will be sent anymore).
367		396
368	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
369	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
370	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.
371		403
372	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
373	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
374	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>).
375		408
376	Example: fork a process and wait for it	409	Example: fork a process and wait for it
377		410
378	my $done = AnyEvent->condvar;	411	my $done = AnyEvent->condvar;
379		412
…		…
389	);	422	);
390		423
391	# do something else, then wait for process exit	424	# do something else, then wait for process exit
392	$done->recv;	425	$done->recv;
393		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
394	=head2 CONDITION VARIABLES	462	=head2 CONDITION VARIABLES
395		463
396	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
397	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
398	will actively watch for new events and call your callbacks.	466	will actively watch for new events and call your callbacks.
399		467
400	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
401	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).
402		470
403	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
404	because they represent a condition that must become true.	472	because they represent a condition that must become true.
405		473
		474	Now is probably a good time to look at the examples further below.
		475
406	Condition variables can be created by calling the C<< AnyEvent->condvar	476	Condition variables can be created by calling the C<< AnyEvent->condvar
407	>> method, usually without arguments. The only argument pair allowed is	477	>> method, usually without arguments. The only argument pair allowed is
408
409	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
410	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
411	the results).	480	the results).
412		481
413	After creation, the condition variable is "false" until it becomes "true"	482	After creation, the condition variable is "false" until it becomes "true"
…		…
462	after => 1,	531	after => 1,
463	cb => sub { $result_ready->send },	532	cb => sub { $result_ready->send },
464	);	533	);
465		534
466	# this "blocks" (while handling events) till the callback	535	# this "blocks" (while handling events) till the callback
467	# calls send	536	# calls -<send
468	$result_ready->recv;	537	$result_ready->recv;
469		538
470	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
471	condition variables are also code references.	540	variables are also callable directly.
472		541
473	my $done = AnyEvent->condvar;	542	my $done = AnyEvent->condvar;
474	my $delay = AnyEvent->timer (after => 5, cb => $done);	543	my $delay = AnyEvent->timer (after => 5, cb => $done);
475	$done->recv;	544	$done->recv;
476		545
…		…
482		551
483	...	552	...
484		553
485	my @info = $couchdb->info->recv;	554	my @info = $couchdb->info->recv;
486		555
487	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
488	results are available:	557	results are available:
489		558
490	$couchdb->info->cb (sub {	559	$couchdb->info->cb (sub {
491	my @info = $_[0]->recv;	560	my @info = $_[0]->recv;
492	});	561	});
…		…
510	immediately from within send.	579	immediately from within send.
511		580
512	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
513	future C<< ->recv >> calls.	582	future C<< ->recv >> calls.
514		583
515	Condition variables are overloaded so one can call them directly	584	Condition variables are overloaded so one can call them directly (as if
516	(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
517	C<send>. Note, however, that many C-based event loops do not handle	586	C<send>.
518	overloading, so as tempting as it may be, passing a condition variable
519	instead of a callback does not work. Both the pure perl and EV loops
520	support overloading, however, as well as all functions that use perl to
521	invoke a callback (as in L<AnyEvent::Socket> and L<AnyEvent::DNS> for
522	example).
523		587
524	=item $cv->croak ($error)	588	=item $cv->croak ($error)
525		589
526	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
527	C<Carp::croak> with the given error message/object/scalar.	591	C<Carp::croak> with the given error message/object/scalar.
528		592
529	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
530	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.
531		599
532	=item $cv->begin ([group callback])	600	=item $cv->begin ([group callback])
533		601
534	=item $cv->end	602	=item $cv->end
535
536	These two methods are EXPERIMENTAL and MIGHT CHANGE.
537		603
538	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
539	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
540	to use a condition variable for the whole process.	606	to use a condition variable for the whole process.
541		607
…		…
543	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
544	>>, 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
545	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
546	callback was set, C<send> will be called without any arguments.	612	callback was set, C<send> will be called without any arguments.
547		613
548	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:
549		645
550	my $cv = AnyEvent->condvar;	646	my $cv = AnyEvent->condvar;
551		647
552	my %result;	648	my %result;
553	$cv->begin (sub { $cv->send (\%result) });	649	$cv->begin (sub { $cv->send (\%result) });
…		…
573	loop, which serves two important purposes: first, it sets the callback	669	loop, which serves two important purposes: first, it sets the callback
574	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
575	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
576	doesn't execute once).	672	doesn't execute once).
577		673
578	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
579	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
580	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
581	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>.
582		679
583	=back	680	=back
584		681
585	=head3 METHODS FOR CONSUMERS	682	=head3 METHODS FOR CONSUMERS
586		683
…		…
602	function will call C<croak>.	699	function will call C<croak>.
603		700
604	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,
605	in scalar context only the first one will be returned.	702	in scalar context only the first one will be returned.
606		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
607	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
608	(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
609	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
610	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
611	condition variables with some kind of request results and supporting	715	condition variables with some kind of request results and supporting
612	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,
613	while still supporting blocking waits if the caller so desires).	717	while still supporting blocking waits if the caller so desires).
614		718
615	Another reason I<never> to C<< ->recv >> in a module is that you cannot
616	sensibly have two C<< ->recv >>'s in parallel, as that would require
617	multiple interpreters or coroutines/threads, none of which C<AnyEvent>
618	can supply.
619
620	The L<Coro> module, however, I<can> and I<does> supply coroutines and, in
621	fact, L<Coro::AnyEvent> replaces AnyEvent's condvars by coroutine-safe
622	versions and also integrates coroutines into AnyEvent, making blocking
623	C<< ->recv >> calls perfectly safe as long as they are done from another
624	coroutine (one that doesn't run the event loop).
625
626	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
627	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
628	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
629	waits otherwise.	722	waits otherwise.
630		723
…		…
643	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
644	is guaranteed not to block.	737	is guaranteed not to block.
645		738
646	=back	739	=back
647		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
648	=head1 GLOBAL VARIABLES AND FUNCTIONS	808	=head1 GLOBAL VARIABLES AND FUNCTIONS
649		809
		810	These are not normally required to use AnyEvent, but can be useful to
		811	write AnyEvent extension modules.
		812
650	=over 4	813	=over 4
651		814
652	=item $AnyEvent::MODEL	815	=item $AnyEvent::MODEL
653		816
654	Contains C<undef> until the first watcher is being created. Then it	817	Contains C<undef> until the first watcher is being created, before the
		818	backend has been autodetected.
		819
655	contains the event model that is being used, which is the name of the	820	Afterwards it contains the event model that is being used, which is the
656	Perl class implementing the model. This class is usually one of the	821	name of the Perl class implementing the model. This class is usually one
657	C<AnyEvent::Impl:xxx> modules, but can be any other class in the case	822	of the C<AnyEvent::Impl:xxx> modules, but can be any other class in the
658	AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode>).	823	case AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode> it
659		824	will be C<urxvt::anyevent>).
660	The known classes so far are:
661
662	AnyEvent::Impl::EV based on EV (an interface to libev, best choice).
663	AnyEvent::Impl::Event based on Event, second best choice.
664	AnyEvent::Impl::Perl pure-perl implementation, fast and portable.
665	AnyEvent::Impl::Glib based on Glib, third-best choice.
666	AnyEvent::Impl::Tk based on Tk, very bad choice.
667	AnyEvent::Impl::Qt based on Qt, cannot be autoprobed (see its docs).
668	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
669	AnyEvent::Impl::POE based on POE, not generic enough for full support.
670
671	There is no support for WxWidgets, as WxWidgets has no support for
672	watching file handles. However, you can use WxWidgets through the
673	POE Adaptor, as POE has a Wx backend that simply polls 20 times per
674	second, which was considered to be too horrible to even consider for
675	AnyEvent. Likewise, other POE backends can be used by AnyEvent by using
676	it's adaptor.
677
678	AnyEvent knows about L<Prima> and L<Wx> and will try to use L<POE> when
679	autodetecting them.
680		825
681	=item AnyEvent::detect	826	=item AnyEvent::detect
682		827
683	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model	828	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model
684	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
685	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
686	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>.
687		835
688	=item $guard = AnyEvent::post_detect { BLOCK }	836	=item $guard = AnyEvent::post_detect { BLOCK }
689		837
690	Arranges for the code block to be executed as soon as the event model is	838	Arranges for the code block to be executed as soon as the event model is
691	autodetected (or immediately if this has already happened).	839	autodetected (or immediately if this has already happened).
		840
		841	The block will be executed I<after> the actual backend has been detected
		842	(C<$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.
692		851
693	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
694	that automatically removes the callback again when it is destroyed. See	853	that automatically removes the callback again when it is destroyed. See
695	L<Coro::BDB> for a case where this is useful.	854	L<Coro::BDB> for a case where this is useful.
696		855
…		…
699	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
700	before or after loading AnyEvent), then they will called directly after	859	before or after loading AnyEvent), then they will called directly after
701	the event loop has been chosen.	860	the event loop has been chosen.
702		861
703	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:
704	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
705	and the array will be ignored.	864	array will be ignored.
706		865
707	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.
708		873
709	=back	874	=back
710		875
711	=head1 WHAT TO DO IN A MODULE	876	=head1 WHAT TO DO IN A MODULE
712		877
…		…
767		932
768		933
769	=head1 OTHER MODULES	934	=head1 OTHER MODULES
770		935
771	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
772	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
773	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
774	available via CPAN.	939	come with AnyEvent, most are available via CPAN.
775		940
776	=over 4	941	=over 4
777		942
778	=item L<AnyEvent::Util>	943	=item L<AnyEvent::Util>
779		944
…		…
788		953
789	=item L<AnyEvent::Handle>	954	=item L<AnyEvent::Handle>
790		955
791	Provide read and write buffers, manages watchers for reads and writes,	956	Provide read and write buffers, manages watchers for reads and writes,
792	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
793	non-blocking SSL/TLS.	958	non-blocking SSL/TLS (via L<AnyEvent::TLS>.
794		959
795	=item L<AnyEvent::DNS>	960	=item L<AnyEvent::DNS>
796		961
797	Provides rich asynchronous DNS resolver capabilities.	962	Provides rich asynchronous DNS resolver capabilities.
798		963
…		…
826		991
827	=item L<AnyEvent::GPSD>	992	=item L<AnyEvent::GPSD>
828		993
829	A non-blocking interface to gpsd, a daemon delivering GPS information.	994	A non-blocking interface to gpsd, a daemon delivering GPS information.
830		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
831	=item L<AnyEvent::IGS>	1005	=item L<AnyEvent::IGS>
832		1006
833	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
834	L<App::IGS>).	1008	L<App::IGS>).
835		1009
836	=item L<AnyEvent::IRC>
837
838	AnyEvent based IRC client module family (replacing the older Net::IRC3).
839
840	=item L<Net::XMPP2>
841
842	AnyEvent based XMPP (Jabber protocol) module family.
843
844	=item L<Net::FCP>	1010	=item L<Net::FCP>
845		1011
846	AnyEvent-based implementation of the Freenet Client Protocol, birthplace	1012	AnyEvent-based implementation of the Freenet Client Protocol, birthplace
847	of AnyEvent.	1013	of AnyEvent.
848		1014
…		…
852		1018
853	=item L<Coro>	1019	=item L<Coro>
854		1020
855	Has special support for AnyEvent via L<Coro::AnyEvent>.	1021	Has special support for AnyEvent via L<Coro::AnyEvent>.
856		1022
857	=item L<IO::Lambda>
858
859	The lambda approach to I/O - don't ask, look there. Can use AnyEvent.
860
861	=back	1023	=back
862		1024
863	=cut	1025	=cut
864		1026
865	package AnyEvent;	1027	package AnyEvent;
866		1028
867	no warnings;	1029	no warnings;
868	use strict qw(vars subs);	1030	use strict qw(vars subs);
869		1031
870	use Carp;	1032	use Carp ();
871		1033
872	our $VERSION = 4.341;	1034	our $VERSION = 4.83;
873	our $MODEL;	1035	our $MODEL;
874		1036
875	our $AUTOLOAD;	1037	our $AUTOLOAD;
876	our @ISA;	1038	our @ISA;
877		1039
878	our @REGISTRY;	1040	our @REGISTRY;
879		1041
880	our $WIN32;	1042	our $WIN32;
881		1043
882	BEGIN {	1044	BEGIN {
883	my $win32 = ! ! ($^O =~ /mswin32/i);	1045	eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }";
884	eval "sub WIN32(){ $win32 }";	1046	eval "sub TAINT(){ " . (${^TAINT}*1) . " }";
		1047
		1048	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}
		1049	if ${^TAINT};
885	}	1050	}
886		1051
887	our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1;	1052	our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1;
888		1053
889	our %PROTOCOL; # (ipv4\|ipv6) => (1\|2), higher numbers are preferred	1054	our %PROTOCOL; # (ipv4\|ipv6) => (1\|2), higher numbers are preferred
…		…
900	[Event:: => AnyEvent::Impl::Event::],	1065	[Event:: => AnyEvent::Impl::Event::],
901	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::],	1066	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::],
902	# everything below here will not be autoprobed	1067	# everything below here will not be autoprobed
903	# as the pureperl backend should work everywhere	1068	# as the pureperl backend should work everywhere
904	# and is usually faster	1069	# and is usually faster
905	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
906	[Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers	1070	[Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers
907	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy	1071	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
		1072	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
908	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program	1073	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program
909	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza	1074	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
910	[Wx:: => AnyEvent::Impl::POE::],	1075	[Wx:: => AnyEvent::Impl::POE::],
911	[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
912	);	1084	);
913		1085
914	our %method = map +($_ => 1), qw(io timer time now signal child condvar one_event DESTROY);	1086	our %method = map +($_ => 1),
		1087	qw(io timer time now now_update signal child idle condvar one_event DESTROY);
915		1088
916	our @post_detect;	1089	our @post_detect;
917		1090
918	sub post_detect(&) {	1091	sub post_detect(&) {
919	my ($cb) = @_;	1092	my ($cb) = @_;
…		…
924	1	1097	1
925	} else {	1098	} else {
926	push @post_detect, $cb;	1099	push @post_detect, $cb;
927		1100
928	defined wantarray	1101	defined wantarray
929	? bless \$cb, "AnyEvent::Util::PostDetect"	1102	? bless \$cb, "AnyEvent::Util::postdetect"
930	: ()	1103	: ()
931	}	1104	}
932	}	1105	}
933		1106
934	sub AnyEvent::Util::PostDetect::DESTROY {	1107	sub AnyEvent::Util::postdetect::DESTROY {
935	@post_detect = grep $_ != ${$_[0]}, @post_detect;	1108	@post_detect = grep $_ != ${$_[0]}, @post_detect;
936	}	1109	}
937		1110
938	sub detect() {	1111	sub detect() {
939	unless ($MODEL) {	1112	unless ($MODEL) {
…		…
942		1115
943	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {	1116	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {
944	my $model = "AnyEvent::Impl::$1";	1117	my $model = "AnyEvent::Impl::$1";
945	if (eval "require $model") {	1118	if (eval "require $model") {
946	$MODEL = $model;	1119	$MODEL = $model;
947	warn "AnyEvent: loaded model '$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 $verbose > 1;
948	} else {	1121	} else {
949	warn "AnyEvent: unable to load model '$model' (from \$PERL_ANYEVENT_MODEL):\n$@" if $verbose;	1122	warn "AnyEvent: unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@" if $verbose;
950	}	1123	}
951	}	1124	}
952		1125
953	# check for already loaded models	1126	# check for already loaded models
954	unless ($MODEL) {	1127	unless ($MODEL) {
…		…
976	last;	1149	last;
977	}	1150	}
978	}	1151	}
979		1152
980	$MODEL	1153	$MODEL
981	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.";	1154	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.\n";
982	}	1155	}
983	}	1156	}
984		1157
985	push @{"$MODEL\::ISA"}, "AnyEvent::Base";	1158	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
986		1159
…		…
996		1169
997	sub AUTOLOAD {	1170	sub AUTOLOAD {
998	(my $func = $AUTOLOAD) =~ s/.*://;	1171	(my $func = $AUTOLOAD) =~ s/.*://;
999		1172
1000	$method{$func}	1173	$method{$func}
1001	or croak "$func: not a valid method for AnyEvent objects";	1174	or Carp::croak "$func: not a valid method for AnyEvent objects";
1002		1175
1003	detect unless $MODEL;	1176	detect unless $MODEL;
1004		1177
1005	my $class = shift;	1178	my $class = shift;
1006	$class->$func (@_);	1179	$class->$func (@_);
1007	}	1180	}
1008		1181
1009	# 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
1010	# to support binding more than one watcher per filehandle (they usually	1183	# to support binding more than one watcher per filehandle (they usually
1011	# 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).
1012	sub _dupfh($$$$) {	1185	sub _dupfh($$;$$) {
1013	my ($poll, $fh, $r, $w) = @_;	1186	my ($poll, $fh, $r, $w) = @_;
1014		1187
1015	# cygwin requires the fh mode to be matching, unix doesn't	1188	# cygwin requires the fh mode to be matching, unix doesn't
1016	my ($rw, $mode) = $poll eq "r" ? ($r, "<")	1189	my ($rw, $mode) = $poll eq "r" ? ($r, "<&") : ($w, ">&");
1017	: $poll eq "w" ? ($w, ">")
1018	: Carp::croak "AnyEvent->io requires poll set to either 'r' or 'w'";
1019		1190
1020	open my $fh2, "$mode&" . fileno $fh	1191	open my $fh2, $mode, $fh
1021	or die "cannot dup() filehandle: $!";	1192	or die "AnyEvent->io: cannot dup() filehandle in mode '$poll': $!,";
1022		1193
1023	# 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
1024		1195
1025	($fh2, $rw)	1196	($fh2, $rw)
1026	}	1197	}
1027		1198
1028	package AnyEvent::Base;	1199	package AnyEvent::Base;
1029		1200
1030	# default implementation for now and time	1201	# default implementations for many methods
1031		1202
1032	BEGIN {	1203	BEGIN {
1033	if (eval "use Time::HiRes (); time (); 1") {	1204	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {
1034	*_time = \&Time::HiRes::time;	1205	*_time = \&Time::HiRes::time;
1035	# if (eval "use POSIX (); (POSIX::times())...	1206	# if (eval "use POSIX (); (POSIX::times())...
1036	} else {	1207	} else {
1037	*_time = sub { time }; # epic fail	1208	*_time = sub { time }; # epic fail
1038	}	1209	}
1039	}	1210	}
1040		1211
1041	sub time { _time }	1212	sub time { _time }
1042	sub now { _time }	1213	sub now { _time }
		1214	sub now_update { }
1043		1215
1044	# default implementation for ->condvar	1216	# default implementation for ->condvar
1045		1217
1046	sub condvar {	1218	sub condvar {
1047	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, AnyEvent::CondVar::	1219	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"
1048	}	1220	}
1049		1221
1050	# default implementation for ->signal	1222	# default implementation for ->signal
1051		1223
1052	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);	1224	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);
…		…
1064		1236
1065	sub signal {	1237	sub signal {
1066	my (undef, %arg) = @_;	1238	my (undef, %arg) = @_;
1067		1239
1068	unless ($SIGPIPE_R) {	1240	unless ($SIGPIPE_R) {
		1241	require Fcntl;
		1242
1069	if (AnyEvent::WIN32) {	1243	if (AnyEvent::WIN32) {
		1244	require AnyEvent::Util;
		1245
1070	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();	1246	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
1071	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R) if $SIGPIPE_R;	1247	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R) if $SIGPIPE_R;
1072	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W) if $SIGPIPE_W; # just in case	1248	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W) if $SIGPIPE_W; # just in case
1073	} else {	1249	} else {
1074	pipe $SIGPIPE_R, $SIGPIPE_W;	1250	pipe $SIGPIPE_R, $SIGPIPE_W;
1075	require Fcntl;
1076	fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R;	1251	fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R;
1077	fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case	1252	fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case
		1253
		1254	# not strictly required, as $^F is normally 2, but let's make sure...
		1255	fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
		1256	fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
1078	}	1257	}
1079		1258
1080	$SIGPIPE_R	1259	$SIGPIPE_R
1081	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";	1260	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";
1082		1261
…		…
1086	my $signal = uc $arg{signal}	1265	my $signal = uc $arg{signal}
1087	or Carp::croak "required option 'signal' is missing";	1266	or Carp::croak "required option 'signal' is missing";
1088		1267
1089	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};	1268	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
1090	$SIG{$signal} \|\|= sub {	1269	$SIG{$signal} \|\|= sub {
		1270	local $!;
1091	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;	1271	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;
1092	undef $SIG_EV{$signal};	1272	undef $SIG_EV{$signal};
1093	};	1273	};
1094		1274
1095	bless [$signal, $arg{cb}], "AnyEvent::Base::Signal"	1275	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
1096	}	1276	}
1097		1277
1098	sub AnyEvent::Base::Signal::DESTROY {	1278	sub AnyEvent::Base::signal::DESTROY {
1099	my ($signal, $cb) = @{$_[0]};	1279	my ($signal, $cb) = @{$_[0]};
1100		1280
1101	delete $SIG_CB{$signal}{$cb};	1281	delete $SIG_CB{$signal}{$cb};
1102		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.
1103	delete $SIG{$signal} unless keys %{ $SIG_CB{$signal} };	1286	undef $SIG{$signal} unless keys %{ $SIG_CB{$signal} };
1104	}	1287	}
1105		1288
1106	# default implementation for ->child	1289	# default implementation for ->child
1107		1290
1108	our %PID_CB;	1291	our %PID_CB;
1109	our $CHLD_W;	1292	our $CHLD_W;
1110	our $CHLD_DELAY_W;	1293	our $CHLD_DELAY_W;
1111	our $PID_IDLE;
1112	our $WNOHANG;	1294	our $WNOHANG;
1113		1295
1114	sub _child_wait {	1296	sub _sigchld {
1115	while (0 < (my $pid = waitpid -1, $WNOHANG)) {	1297	while (0 < (my $pid = waitpid -1, $WNOHANG)) {
1116	$_->($pid, $?) for (values %{ $PID_CB{$pid} \|\| {} }),	1298	$_->($pid, $?) for (values %{ $PID_CB{$pid} \|\| {} }),
1117	(values %{ $PID_CB{0} \|\| {} });	1299	(values %{ $PID_CB{0} \|\| {} });
1118	}	1300	}
1119
1120	undef $PID_IDLE;
1121	}
1122
1123	sub _sigchld {
1124	# make sure we deliver these changes "synchronous" with the event loop.
1125	$CHLD_DELAY_W \|\|= AnyEvent->timer (after => 0, cb => sub {
1126	undef $CHLD_DELAY_W;
1127	&_child_wait;
1128	});
1129	}	1301	}
1130		1302
1131	sub child {	1303	sub child {
1132	my (undef, %arg) = @_;	1304	my (undef, %arg) = @_;
1133		1305
1134	defined (my $pid = $arg{pid} + 0)	1306	defined (my $pid = $arg{pid} + 0)
1135	or Carp::croak "required option 'pid' is missing";	1307	or Carp::croak "required option 'pid' is missing";
1136		1308
1137	$PID_CB{$pid}{$arg{cb}} = $arg{cb};	1309	$PID_CB{$pid}{$arg{cb}} = $arg{cb};
1138		1310
1139	unless ($WNOHANG) {
1140	$WNOHANG = eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } \|\| 1;	1311	$WNOHANG \|\|= eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } \|\| 1;
1141	}
1142		1312
1143	unless ($CHLD_W) {	1313	unless ($CHLD_W) {
1144	$CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld);	1314	$CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld);
1145	# 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
1146	&_sigchld;	1316	&_sigchld;
1147	}	1317	}
1148		1318
1149	bless [$pid, $arg{cb}], "AnyEvent::Base::Child"	1319	bless [$pid, $arg{cb}], "AnyEvent::Base::child"
1150	}	1320	}
1151		1321
1152	sub AnyEvent::Base::Child::DESTROY {	1322	sub AnyEvent::Base::child::DESTROY {
1153	my ($pid, $cb) = @{$_[0]};	1323	my ($pid, $cb) = @{$_[0]};
1154		1324
1155	delete $PID_CB{$pid}{$cb};	1325	delete $PID_CB{$pid}{$cb};
1156	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };	1326	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };
1157		1327
1158	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]};
1159	}	1365	}
1160		1366
1161	package AnyEvent::CondVar;	1367	package AnyEvent::CondVar;
1162		1368
1163	our @ISA = AnyEvent::CondVar::Base::;	1369	our @ISA = AnyEvent::CondVar::Base::;
…		…
1165	package AnyEvent::CondVar::Base;	1371	package AnyEvent::CondVar::Base;
1166		1372
1167	use overload	1373	use overload
1168	'&{}' => sub { my $self = shift; sub { $self->send (@_) } },	1374	'&{}' => sub { my $self = shift; sub { $self->send (@_) } },
1169	fallback => 1;	1375	fallback => 1;
		1376
		1377	our $WAITING;
1170		1378
1171	sub _send {	1379	sub _send {
1172	# nop	1380	# nop
1173	}	1381	}
1174		1382
…		…
1187	sub ready {	1395	sub ready {
1188	$_[0]{_ae_sent}	1396	$_[0]{_ae_sent}
1189	}	1397	}
1190		1398
1191	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 $WAITING = 1;
1192	AnyEvent->one_event while !$_[0]{_ae_sent};	1405	AnyEvent->one_event while !$_[0]{_ae_sent};
1193	}	1406	}
1194		1407
1195	sub recv {	1408	sub recv {
1196	$_[0]->_wait;	1409	$_[0]->_wait;
…		…
1237	so on.	1450	so on.
1238		1451
1239	=head1 ENVIRONMENT VARIABLES	1452	=head1 ENVIRONMENT VARIABLES
1240		1453
1241	The following environment variables are used by this module or its	1454	The following environment variables are used by this module or its
1242	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.
1243		1460
1244	=over 4	1461	=over 4
1245		1462
1246	=item C<PERL_ANYEVENT_VERBOSE>	1463	=item C<PERL_ANYEVENT_VERBOSE>
1247		1464
…		…
1259	=item C<PERL_ANYEVENT_STRICT>	1476	=item C<PERL_ANYEVENT_STRICT>
1260		1477
1261	AnyEvent does not do much argument checking by default, as thorough	1478	AnyEvent does not do much argument checking by default, as thorough
1262	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
1263	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
1264	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,
1265	it will croak.	1482	it will croak.
1266		1483
1267	In other words, enables "strict" mode.	1484	In other words, enables "strict" mode.
1268		1485
1269	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
1270	production. Keeping C<PERL_ANYEVENT_STRICT=1> in your environment while	1487	production. Keeping C<PERL_ANYEVENT_STRICT=1> in your environment while
1271	developing programs can be very useful, however.	1488	developing programs can be very useful, however.
1272		1489
1273	=item C<PERL_ANYEVENT_MODEL>	1490	=item C<PERL_ANYEVENT_MODEL>
1274		1491
…		…
1319		1536
1320	=item C<PERL_ANYEVENT_MAX_FORKS>	1537	=item C<PERL_ANYEVENT_MAX_FORKS>
1321		1538
1322	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>
1323	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.
1324		1560
1325	=back	1561	=back
1326		1562
1327	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE	1563	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE
1328		1564
…		…
1573	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
1574	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
1575	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
1576	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
1577	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
1578	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
1579	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
1580	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
1581	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
1582		1820
…		…
1611	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
1612	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.
1613		1851
1614	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
1615	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.
1616		1857
1617	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
1618	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
1619	C<Event>. However, Glib scales extremely badly, doubling the number of	1860	C<Event>. However, Glib scales extremely badly, doubling the number of
1620	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,
…		…
1698	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
1699	a new one that moves the timeout into the future.	1940	a new one that moves the timeout into the future.
1700		1941
1701	=head3 Results	1942	=head3 Results
1702		1943
1703	name sockets create request	1944	name sockets create request
1704	EV 20000 69.01 11.16	1945	EV 20000 69.01 11.16
1705	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
1706	Event 20000 212.62 257.32	1949	Event 20000 212.62 257.32
1707	Glib 20000 651.16 1896.30	1950	Glib 20000 651.16 1896.30
1708	POE 20000 349.67 12317.24 uses POE::Loop::Event	1951	POE 20000 349.67 12317.24 uses POE::Loop::Event
1709		1952
1710	=head3 Discussion	1953	=head3 Discussion
1711		1954
1712	This benchmark I<does> measure scalability and overall performance of the	1955	This benchmark I<does> measure scalability and overall performance of the
1713	particular event loop.	1956	particular event loop.
…		…
1715	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
1716	is relatively high, though.	1959	is relatively high, though.
1717		1960
1718	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
1719	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.
1720		1966
1721	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
1722	understand why). Callback invocation also has a high overhead compared to	1968	understand why). Callback invocation also has a high overhead compared to
1723	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
1724	uses select or poll in basically all documented configurations.	1970	uses select or poll in basically all documented configurations.
…		…
1787	=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
1788	watchers, as the management overhead dominates.	2034	watchers, as the management overhead dominates.
1789		2035
1790	=back	2036	=back
1791		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
1792		2095
1793	=head1 SIGNALS	2096	=head1 SIGNALS
1794		2097
1795	AnyEvent currently installs handlers for these signals:	2098	AnyEvent currently installs handlers for these signals:
1796		2099
…		…
1799	=item SIGCHLD	2102	=item SIGCHLD
1800		2103
1801	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
1802	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
1803	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.
1804		2110
1805	=item SIGPIPE	2111	=item SIGPIPE
1806		2112
1807	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>
1808	when AnyEvent gets loaded.	2114	when AnyEvent gets loaded.
…		…
1820		2126
1821	=back	2127	=back
1822		2128
1823	=cut	2129	=cut
1824		2130
		2131	undef $SIG{CHLD}
		2132	if $SIG{CHLD} eq 'IGNORE';
		2133
1825	$SIG{PIPE} = sub { }	2134	$SIG{PIPE} = sub { }
1826	unless defined $SIG{PIPE};	2135	unless defined $SIG{PIPE};
1827
1828		2136
1829	=head1 FORK	2137	=head1 FORK
1830		2138
1831	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
1832	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>
…		…
1853	use AnyEvent;	2161	use AnyEvent;
1854		2162
1855	Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can	2163	Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can
1856	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
1857	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
1858	$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.
1859		2171
1860		2172
1861	=head1 BUGS	2173	=head1 BUGS
1862		2174
1863	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
…		…
1875	L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.	2187	L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.
1876		2188
1877	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,	2189	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,
1878	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>,
1879	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,	2191	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,
1880	L<AnyEvent::Impl::POE>.	2192	L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>.
1881		2193
1882	Non-blocking file handles, sockets, TCP clients and	2194	Non-blocking file handles, sockets, TCP clients and
1883	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>.	2195	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.
1884		2196
1885	Asynchronous DNS: L<AnyEvent::DNS>.	2197	Asynchronous DNS: L<AnyEvent::DNS>.
1886		2198
1887	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>,
1888		2201
1889	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>.
1890		2204
1891		2205
1892	=head1 AUTHOR	2206	=head1 AUTHOR
1893		2207
1894	Marc Lehmann <schmorp@schmorp.de>	2208	Marc Lehmann <schmorp@schmorp.de>

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Comparing AnyEvent/lib/AnyEvent.pm (file contents): Revision 1.198 by root, Thu Mar 26 20:17:44 2009 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 1.198 by root, Thu Mar 26 20:17:44 2009 UTC vs.
Revision 1.241 by root, Fri Jul 17 18:08:35 2009 UTC