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Revision 1.251 by root, Mon Jul 20 22:39:57 2009 UTC vs.
Revision 1.326 by root, Sun Jun 6 10:11:56 2010 UTC

1	=head1 NAME	1	=head1 NAME
2		2
3	AnyEvent - events independent of event loop implementation	3	AnyEvent - the DBI of event loop programming
4		4
5	EV, Event, Glib, Tk, Perl, Event::Lib, Qt and POE are various supported	5	EV, Event, Glib, Tk, Perl, Event::Lib, Irssi, rxvt-unicode, IO::Async, Qt
6	event loops.	6	and POE are various supported event loops/environments.
7		7
8	=head1 SYNOPSIS	8	=head1 SYNOPSIS
9		9
10	use AnyEvent;	10	use AnyEvent;
11		11
		12	# if you prefer function calls, look at the AE manpage for
		13	# an alternative API.
		14
12	# file descriptor readable	15	# file handle or descriptor readable
13	my $w = AnyEvent->io (fh => $fh, poll => "r", cb => sub { ... });	16	my $w = AnyEvent->io (fh => $fh, poll => "r", cb => sub { ... });
14		17
15	# one-shot or repeating timers	18	# one-shot or repeating timers
16	my $w = AnyEvent->timer (after => $seconds, cb => sub { ... });	19	my $w = AnyEvent->timer (after => $seconds, cb => sub { ... });
17	my $w = AnyEvent->timer (after => $seconds, interval => $seconds, cb => ...	20	my $w = AnyEvent->timer (after => $seconds, interval => $seconds, cb => ...
…		…
47		50
48	There is a mailinglist for discussing all things AnyEvent, and an IRC	51	There is a mailinglist for discussing all things AnyEvent, and an IRC
49	channel, too.	52	channel, too.
50		53
51	See the AnyEvent project page at the B<Schmorpforge Ta-Sa Software	54	See the AnyEvent project page at the B<Schmorpforge Ta-Sa Software
52	Respository>, at L<http://anyevent.schmorp.de>, for more info.	55	Repository>, at L<http://anyevent.schmorp.de>, for more info.
53		56
54	=head1 WHY YOU SHOULD USE THIS MODULE (OR NOT)	57	=head1 WHY YOU SHOULD USE THIS MODULE (OR NOT)
55		58
56	Glib, POE, IO::Async, Event... CPAN offers event models by the dozen	59	Glib, POE, IO::Async, Event... CPAN offers event models by the dozen
57	nowadays. So what is different about AnyEvent?	60	nowadays. So what is different about AnyEvent?
…		…
181	my variables are only visible after the statement in which they are	184	my variables are only visible after the statement in which they are
182	declared.	185	declared.
183		186
184	=head2 I/O WATCHERS	187	=head2 I/O WATCHERS
185		188
		189	$w = AnyEvent->io (
		190	fh => <filehandle_or_fileno>,
		191	poll => <"r" or "w">,
		192	cb => <callback>,
		193	);
		194
186	You can create an I/O watcher by calling the C<< AnyEvent->io >> method	195	You can create an I/O watcher by calling the C<< AnyEvent->io >> method
187	with the following mandatory key-value pairs as arguments:	196	with the following mandatory key-value pairs as arguments:
188		197
189	C<fh> is the Perl I<file handle> (or a naked file descriptor) to watch	198	C<fh> is the Perl I<file handle> (or a naked file descriptor) to watch
190	for events (AnyEvent might or might not keep a reference to this file	199	for events (AnyEvent might or might not keep a reference to this file
…		…
219	undef $w;	228	undef $w;
220	});	229	});
221		230
222	=head2 TIME WATCHERS	231	=head2 TIME WATCHERS
223		232
		233	$w = AnyEvent->timer (after => <seconds>, cb => <callback>);
		234
		235	$w = AnyEvent->timer (
		236	after => <fractional_seconds>,
		237	interval => <fractional_seconds>,
		238	cb => <callback>,
		239	);
		240
224	You can create a time watcher by calling the C<< AnyEvent->timer >>	241	You can create a time watcher by calling the C<< AnyEvent->timer >>
225	method with the following mandatory arguments:	242	method with the following mandatory arguments:
226		243
227	C<after> specifies after how many seconds (fractional values are	244	C<after> specifies after how many seconds (fractional values are
228	supported) the callback should be invoked. C<cb> is the callback to invoke	245	supported) the callback should be invoked. C<cb> is the callback to invoke
…		…
349	might affect timers and time-outs.	366	might affect timers and time-outs.
350		367
351	When this is the case, you can call this method, which will update the	368	When this is the case, you can call this method, which will update the
352	event loop's idea of "current time".	369	event loop's idea of "current time".
353		370
		371	A typical example would be a script in a web server (e.g. C<mod_perl>) -
		372	when mod_perl executes the script, then the event loop will have the wrong
		373	idea about the "current time" (being potentially far in the past, when the
		374	script ran the last time). In that case you should arrange a call to C<<
		375	AnyEvent->now_update >> each time the web server process wakes up again
		376	(e.g. at the start of your script, or in a handler).
		377
354	Note that updating the time I<might> cause some events to be handled.	378	Note that updating the time I<might> cause some events to be handled.
355		379
356	=back	380	=back
357		381
358	=head2 SIGNAL WATCHERS	382	=head2 SIGNAL WATCHERS
		383
		384	$w = AnyEvent->signal (signal => <uppercase_signal_name>, cb => <callback>);
359		385
360	You can watch for signals using a signal watcher, C<signal> is the signal	386	You can watch for signals using a signal watcher, C<signal> is the signal
361	I<name> in uppercase and without any C<SIG> prefix, C<cb> is the Perl	387	I<name> in uppercase and without any C<SIG> prefix, C<cb> is the Perl
362	callback to be invoked whenever a signal occurs.	388	callback to be invoked whenever a signal occurs.
363		389
…		…
380		406
381	Example: exit on SIGINT	407	Example: exit on SIGINT
382		408
383	my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });	409	my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });
384		410
		411	=head3 Restart Behaviour
		412
		413	While restart behaviour is up to the event loop implementation, most will
		414	not restart syscalls (that includes L<Async::Interrupt> and AnyEvent's
		415	pure perl implementation).
		416
		417	=head3 Safe/Unsafe Signals
		418
		419	Perl signals can be either "safe" (synchronous to opcode handling) or
		420	"unsafe" (asynchronous) - the former might get delayed indefinitely, the
		421	latter might corrupt your memory.
		422
		423	AnyEvent signal handlers are, in addition, synchronous to the event loop,
		424	i.e. they will not interrupt your running perl program but will only be
		425	called as part of the normal event handling (just like timer, I/O etc.
		426	callbacks, too).
		427
385	=head3 Signal Races, Delays and Workarounds	428	=head3 Signal Races, Delays and Workarounds
386		429
387	Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support attaching	430	Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support attaching
388	callbacks to signals in a generic way, which is a pity, as you cannot do	431	callbacks to signals in a generic way, which is a pity, as you cannot
389	race-free signal handling in perl. AnyEvent will try to do it's best, but	432	do race-free signal handling in perl, requiring C libraries for
		433	this. AnyEvent will try to do it's best, which means in some cases,
390	in some cases, signals will be delayed. The maximum time a signal might	434	signals will be delayed. The maximum time a signal might be delayed is
391	be delayed is specified in C<$AnyEvent::MAX_SIGNAL_LATENCY> (default: 10	435	specified in C<$AnyEvent::MAX_SIGNAL_LATENCY> (default: 10 seconds). This
392	seconds). This variable can be changed only before the first signal	436	variable can be changed only before the first signal watcher is created,
393	watcher is created, and should be left alone otherwise. Higher values	437	and should be left alone otherwise. This variable determines how often
		438	AnyEvent polls for signals (in case a wake-up was missed). Higher values
394	will cause fewer spurious wake-ups, which is better for power and CPU	439	will cause fewer spurious wake-ups, which is better for power and CPU
		440	saving.
		441
395	saving. All these problems can be avoided by installing the optional	442	All these problems can be avoided by installing the optional
396	L<Async::Interrupt> module. This will not work with inherently broken	443	L<Async::Interrupt> module, which works with most event loops. It will not
397	event loops such as L<Event> or L<Event::Lib> (and not with L<POE>	444	work with inherently broken event loops such as L<Event> or L<Event::Lib>
398	currently, as POE does it's own workaround with one-second latency). With	445	(and not with L<POE> currently, as POE does it's own workaround with
399	those, you just have to suffer the delays.	446	one-second latency). For those, you just have to suffer the delays.
400		447
401	=head2 CHILD PROCESS WATCHERS	448	=head2 CHILD PROCESS WATCHERS
402		449
		450	$w = AnyEvent->child (pid => <process id>, cb => <callback>);
		451
403	You can also watch on a child process exit and catch its exit status.	452	You can also watch on a child process exit and catch its exit status.
404		453
405	The child process is specified by the C<pid> argument (if set to C<0>, it	454	The child process is specified by the C<pid> argument (one some backends,
406	watches for any child process exit). The watcher will triggered only when	455	using C<0> watches for any child process exit, on others this will
407	the child process has finished and an exit status is available, not on	456	croak). The watcher will be triggered only when the child process has
408	any trace events (stopped/continued).	457	finished and an exit status is available, not on any trace events
		458	(stopped/continued).
409		459
410	The callback will be called with the pid and exit status (as returned by	460	The callback will be called with the pid and exit status (as returned by
411	waitpid), so unlike other watcher types, you I<can> rely on child watcher	461	waitpid), so unlike other watcher types, you I<can> rely on child watcher
412	callback arguments.	462	callback arguments.
413		463
…		…
454	# do something else, then wait for process exit	504	# do something else, then wait for process exit
455	$done->recv;	505	$done->recv;
456		506
457	=head2 IDLE WATCHERS	507	=head2 IDLE WATCHERS
458		508
459	Sometimes there is a need to do something, but it is not so important	509	$w = AnyEvent->idle (cb => <callback>);
460	to do it instantly, but only when there is nothing better to do. This
461	"nothing better to do" is usually defined to be "no other events need
462	attention by the event loop".
463		510
464	Idle watchers ideally get invoked when the event loop has nothing	511	Repeatedly invoke the callback after the process becomes idle, until
465	better to do, just before it would block the process to wait for new	512	either the watcher is destroyed or new events have been detected.
466	events. Instead of blocking, the idle watcher is invoked.
467		513
468	Most event loops unfortunately do not really support idle watchers (only	514	Idle watchers are useful when there is a need to do something, but it
		515	is not so important (or wise) to do it instantly. The callback will be
		516	invoked only when there is "nothing better to do", which is usually
		517	defined as "all outstanding events have been handled and no new events
		518	have been detected". That means that idle watchers ideally get invoked
		519	when the event loop has just polled for new events but none have been
		520	detected. Instead of blocking to wait for more events, the idle watchers
		521	will be invoked.
		522
		523	Unfortunately, most event loops do not really support idle watchers (only
469	EV, Event and Glib do it in a usable fashion) - for the rest, AnyEvent	524	EV, Event and Glib do it in a usable fashion) - for the rest, AnyEvent
470	will simply call the callback "from time to time".	525	will simply call the callback "from time to time".
471		526
472	Example: read lines from STDIN, but only process them when the	527	Example: read lines from STDIN, but only process them when the
473	program is otherwise idle:	528	program is otherwise idle:
…		…
489	});	544	});
490	});	545	});
491		546
492	=head2 CONDITION VARIABLES	547	=head2 CONDITION VARIABLES
493		548
		549	$cv = AnyEvent->condvar;
		550
		551	$cv->send (<list>);
		552	my @res = $cv->recv;
		553
494	If you are familiar with some event loops you will know that all of them	554	If you are familiar with some event loops you will know that all of them
495	require you to run some blocking "loop", "run" or similar function that	555	require you to run some blocking "loop", "run" or similar function that
496	will actively watch for new events and call your callbacks.	556	will actively watch for new events and call your callbacks.
497		557
498	AnyEvent is slightly different: it expects somebody else to run the event	558	AnyEvent is slightly different: it expects somebody else to run the event
499	loop and will only block when necessary (usually when told by the user).	559	loop and will only block when necessary (usually when told by the user).
500		560
501	The instrument to do that is called a "condition variable", so called	561	The tool to do that is called a "condition variable", so called because
502	because they represent a condition that must become true.	562	they represent a condition that must become true.
503		563
504	Now is probably a good time to look at the examples further below.	564	Now is probably a good time to look at the examples further below.
505		565
506	Condition variables can be created by calling the C<< AnyEvent->condvar	566	Condition variables can be created by calling the C<< AnyEvent->condvar
507	>> method, usually without arguments. The only argument pair allowed is	567	>> method, usually without arguments. The only argument pair allowed is
…		…
512	After creation, the condition variable is "false" until it becomes "true"	572	After creation, the condition variable is "false" until it becomes "true"
513	by calling the C<send> method (or calling the condition variable as if it	573	by calling the C<send> method (or calling the condition variable as if it
514	were a callback, read about the caveats in the description for the C<<	574	were a callback, read about the caveats in the description for the C<<
515	->send >> method).	575	->send >> method).
516		576
517	Condition variables are similar to callbacks, except that you can	577	Since condition variables are the most complex part of the AnyEvent API, here are
518	optionally wait for them. They can also be called merge points - points	578	some different mental models of what they are - pick the ones you can connect to:
519	in time where multiple outstanding events have been processed. And yet	579
520	another way to call them is transactions - each condition variable can be	580	=over 4
521	used to represent a transaction, which finishes at some point and delivers	581
522	a result. And yet some people know them as "futures" - a promise to	582	=item * Condition variables are like callbacks - you can call them (and pass them instead
523	compute/deliver something that you can wait for.	583	of callbacks). Unlike callbacks however, you can also wait for them to be called.
		584
		585	=item * Condition variables are signals - one side can emit or send them,
		586	the other side can wait for them, or install a handler that is called when
		587	the signal fires.
		588
		589	=item * Condition variables are like "Merge Points" - points in your program
		590	where you merge multiple independent results/control flows into one.
		591
		592	=item * Condition variables represent a transaction - function that start
		593	some kind of transaction can return them, leaving the caller the choice
		594	between waiting in a blocking fashion, or setting a callback.
		595
		596	=item * Condition variables represent future values, or promises to deliver
		597	some result, long before the result is available.
		598
		599	=back
524		600
525	Condition variables are very useful to signal that something has finished,	601	Condition variables are very useful to signal that something has finished,
526	for example, if you write a module that does asynchronous http requests,	602	for example, if you write a module that does asynchronous http requests,
527	then a condition variable would be the ideal candidate to signal the	603	then a condition variable would be the ideal candidate to signal the
528	availability of results. The user can either act when the callback is	604	availability of results. The user can either act when the callback is
…		…
549	eventually calls C<< -> send >>, and the "consumer side", which waits	625	eventually calls C<< -> send >>, and the "consumer side", which waits
550	for the send to occur.	626	for the send to occur.
551		627
552	Example: wait for a timer.	628	Example: wait for a timer.
553		629
554	# wait till the result is ready	630	# condition: "wait till the timer is fired"
555	my $result_ready = AnyEvent->condvar;	631	my $timer_fired = AnyEvent->condvar;
556		632
557	# do something such as adding a timer	633	# create the timer - we could wait for, say
558	# or socket watcher the calls $result_ready->send	634	# a handle becomign ready, or even an
559	# when the "result" is ready.	635	# AnyEvent::HTTP request to finish, but
560	# in this case, we simply use a timer:	636	# in this case, we simply use a timer:
561	my $w = AnyEvent->timer (	637	my $w = AnyEvent->timer (
562	after => 1,	638	after => 1,
563	cb => sub { $result_ready->send },	639	cb => sub { $timer_fired->send },
564	);	640	);
565		641
566	# this "blocks" (while handling events) till the callback	642	# this "blocks" (while handling events) till the callback
567	# calls -<send	643	# calls ->send
568	$result_ready->recv;	644	$timer_fired->recv;
569		645
570	Example: wait for a timer, but take advantage of the fact that condition	646	Example: wait for a timer, but take advantage of the fact that condition
571	variables are also callable directly.	647	variables are also callable directly.
572		648
573	my $done = AnyEvent->condvar;	649	my $done = AnyEvent->condvar;
…		…
636	one. For example, a function that pings many hosts in parallel might want	712	one. For example, a function that pings many hosts in parallel might want
637	to use a condition variable for the whole process.	713	to use a condition variable for the whole process.
638		714
639	Every call to C<< ->begin >> will increment a counter, and every call to	715	Every call to C<< ->begin >> will increment a counter, and every call to
640	C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end	716	C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end
641	>>, the (last) callback passed to C<begin> will be executed. That callback	717	>>, the (last) callback passed to C<begin> will be executed, passing the
642	is I<supposed> to call C<< ->send >>, but that is not required. If no	718	condvar as first argument. That callback is I<supposed> to call C<< ->send
643	callback was set, C<send> will be called without any arguments.	719	>>, but that is not required. If no group callback was set, C<send> will
		720	be called without any arguments.
644		721
645	You can think of C<< $cv->send >> giving you an OR condition (one call	722	You can think of C<< $cv->send >> giving you an OR condition (one call
646	sends), while C<< $cv->begin >> and C<< $cv->end >> giving you an AND	723	sends), while C<< $cv->begin >> and C<< $cv->end >> giving you an AND
647	condition (all C<begin> calls must be C<end>'ed before the condvar sends).	724	condition (all C<begin> calls must be C<end>'ed before the condvar sends).
648		725
…		…
675	begung can potentially be zero:	752	begung can potentially be zero:
676		753
677	my $cv = AnyEvent->condvar;	754	my $cv = AnyEvent->condvar;
678		755
679	my %result;	756	my %result;
680	$cv->begin (sub { $cv->send (\%result) });	757	$cv->begin (sub { shift->send (\%result) });
681		758
682	for my $host (@list_of_hosts) {	759	for my $host (@list_of_hosts) {
683	$cv->begin;	760	$cv->begin;
684	ping_host_then_call_callback $host, sub {	761	ping_host_then_call_callback $host, sub {
685	$result{$host} = ...;	762	$result{$host} = ...;
…		…
760	=item $cb = $cv->cb ($cb->($cv))	837	=item $cb = $cv->cb ($cb->($cv))
761		838
762	This is a mutator function that returns the callback set and optionally	839	This is a mutator function that returns the callback set and optionally
763	replaces it before doing so.	840	replaces it before doing so.
764		841
765	The callback will be called when the condition becomes "true", i.e. when	842	The callback will be called when the condition becomes (or already was)
766	C<send> or C<croak> are called, with the only argument being the condition	843	"true", i.e. when C<send> or C<croak> are called (or were called), with
767	variable itself. Calling C<recv> inside the callback or at any later time	844	the only argument being the condition variable itself. Calling C<recv>
768	is guaranteed not to block.	845	inside the callback or at any later time is guaranteed not to block.
769		846
770	=back	847	=back
771		848
772	=head1 SUPPORTED EVENT LOOPS/BACKENDS	849	=head1 SUPPORTED EVENT LOOPS/BACKENDS
773		850
…		…
776	=over 4	853	=over 4
777		854
778	=item Backends that are autoprobed when no other event loop can be found.	855	=item Backends that are autoprobed when no other event loop can be found.
779		856
780	EV is the preferred backend when no other event loop seems to be in	857	EV is the preferred backend when no other event loop seems to be in
781	use. If EV is not installed, then AnyEvent will try Event, and, failing	858	use. If EV is not installed, then AnyEvent will fall back to its own
782	that, will fall back to its own pure-perl implementation, which is	859	pure-perl implementation, which is available everywhere as it comes with
783	available everywhere as it comes with AnyEvent itself.	860	AnyEvent itself.
784		861
785	AnyEvent::Impl::EV based on EV (interface to libev, best choice).	862	AnyEvent::Impl::EV based on EV (interface to libev, best choice).
786	AnyEvent::Impl::Event based on Event, very stable, few glitches.
787	AnyEvent::Impl::Perl pure-perl implementation, fast and portable.	863	AnyEvent::Impl::Perl pure-perl implementation, fast and portable.
788		864
789	=item Backends that are transparently being picked up when they are used.	865	=item Backends that are transparently being picked up when they are used.
790		866
791	These will be used when they are currently loaded when the first watcher	867	These will be used when they are currently loaded when the first watcher
792	is created, in which case it is assumed that the application is using	868	is created, in which case it is assumed that the application is using
793	them. This means that AnyEvent will automatically pick the right backend	869	them. This means that AnyEvent will automatically pick the right backend
794	when the main program loads an event module before anything starts to	870	when the main program loads an event module before anything starts to
795	create watchers. Nothing special needs to be done by the main program.	871	create watchers. Nothing special needs to be done by the main program.
796		872
		873	AnyEvent::Impl::Event based on Event, very stable, few glitches.
797	AnyEvent::Impl::Glib based on Glib, slow but very stable.	874	AnyEvent::Impl::Glib based on Glib, slow but very stable.
798	AnyEvent::Impl::Tk based on Tk, very broken.	875	AnyEvent::Impl::Tk based on Tk, very broken.
799	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.	876	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
800	AnyEvent::Impl::POE based on POE, very slow, some limitations.	877	AnyEvent::Impl::POE based on POE, very slow, some limitations.
		878	AnyEvent::Impl::Irssi used when running within irssi.
801		879
802	=item Backends with special needs.	880	=item Backends with special needs.
803		881
804	Qt requires the Qt::Application to be instantiated first, but will	882	Qt requires the Qt::Application to be instantiated first, but will
805	otherwise be picked up automatically. As long as the main program	883	otherwise be picked up automatically. As long as the main program
…		…
879	event module detection too early, for example, L<AnyEvent::AIO> creates	957	event module detection too early, for example, L<AnyEvent::AIO> creates
880	and installs the global L<IO::AIO> watcher in a C<post_detect> block to	958	and installs the global L<IO::AIO> watcher in a C<post_detect> block to
881	avoid autodetecting the event module at load time.	959	avoid autodetecting the event module at load time.
882		960
883	If called in scalar or list context, then it creates and returns an object	961	If called in scalar or list context, then it creates and returns an object
884	that automatically removes the callback again when it is destroyed. See	962	that automatically removes the callback again when it is destroyed (or
		963	C<undef> when the hook was immediately executed). See L<AnyEvent::AIO> for
885	L<Coro::BDB> for a case where this is useful.	964	a case where this is useful.
		965
		966	Example: Create a watcher for the IO::AIO module and store it in
		967	C<$WATCHER>. Only do so after the event loop is initialised, though.
		968
		969	our WATCHER;
		970
		971	my $guard = AnyEvent::post_detect {
		972	$WATCHER = AnyEvent->io (fh => IO::AIO::poll_fileno, poll => 'r', cb => \&IO::AIO::poll_cb);
		973	};
		974
		975	# the ||= is important in case post_detect immediately runs the block,
		976	# as to not clobber the newly-created watcher. assigning both watcher and
		977	# post_detect guard to the same variable has the advantage of users being
		978	# able to just C<undef $WATCHER> if the watcher causes them grief.
		979
		980	$WATCHER ||= $guard;
886		981
887	=item @AnyEvent::post_detect	982	=item @AnyEvent::post_detect
888		983
889	If there are any code references in this array (you can C<push> to it	984	If there are any code references in this array (you can C<push> to it
890	before or after loading AnyEvent), then they will called directly after	985	before or after loading AnyEvent), then they will called directly after
…		…
893	You should check C<$AnyEvent::MODEL> before adding to this array, though:	988	You should check C<$AnyEvent::MODEL> before adding to this array, though:
894	if it is defined then the event loop has already been detected, and the	989	if it is defined then the event loop has already been detected, and the
895	array will be ignored.	990	array will be ignored.
896		991
897	Best use C<AnyEvent::post_detect { BLOCK }> when your application allows	992	Best use C<AnyEvent::post_detect { BLOCK }> when your application allows
898	it,as it takes care of these details.	993	it, as it takes care of these details.
899		994
900	This variable is mainly useful for modules that can do something useful	995	This variable is mainly useful for modules that can do something useful
901	when AnyEvent is used and thus want to know when it is initialised, but do	996	when AnyEvent is used and thus want to know when it is initialised, but do
902	not need to even load it by default. This array provides the means to hook	997	not need to even load it by default. This array provides the means to hook
903	into AnyEvent passively, without loading it.	998	into AnyEvent passively, without loading it.
		999
		1000	Example: To load Coro::AnyEvent whenever Coro and AnyEvent are used
		1001	together, you could put this into Coro (this is the actual code used by
		1002	Coro to accomplish this):
		1003
		1004	if (defined $AnyEvent::MODEL) {
		1005	# AnyEvent already initialised, so load Coro::AnyEvent
		1006	require Coro::AnyEvent;
		1007	} else {
		1008	# AnyEvent not yet initialised, so make sure to load Coro::AnyEvent
		1009	# as soon as it is
		1010	push @AnyEvent::post_detect, sub { require Coro::AnyEvent };
		1011	}
904		1012
905	=back	1013	=back
906		1014
907	=head1 WHAT TO DO IN A MODULE	1015	=head1 WHAT TO DO IN A MODULE
908		1016
…		…
965	=head1 OTHER MODULES	1073	=head1 OTHER MODULES
966		1074
967	The following is a non-exhaustive list of additional modules that use	1075	The following is a non-exhaustive list of additional modules that use
968	AnyEvent as a client and can therefore be mixed easily with other AnyEvent	1076	AnyEvent as a client and can therefore be mixed easily with other AnyEvent
969	modules and other event loops in the same program. Some of the modules	1077	modules and other event loops in the same program. Some of the modules
970	come with AnyEvent, most are available via CPAN.	1078	come as part of AnyEvent, the others are available via CPAN.
971		1079
972	=over 4	1080	=over 4
973		1081
974	=item L<AnyEvent::Util>	1082	=item L<AnyEvent::Util>
975		1083
…		…
990		1098
991	=item L<AnyEvent::DNS>	1099	=item L<AnyEvent::DNS>
992		1100
993	Provides rich asynchronous DNS resolver capabilities.	1101	Provides rich asynchronous DNS resolver capabilities.
994		1102
		1103	=item L<AnyEvent::HTTP>, L<AnyEvent::IRC>, L<AnyEvent::XMPP>, L<AnyEvent::GPSD>, L<AnyEvent::IGS>, L<AnyEvent::FCP>
		1104
		1105	Implement event-based interfaces to the protocols of the same name (for
		1106	the curious, IGS is the International Go Server and FCP is the Freenet
		1107	Client Protocol).
		1108
		1109	=item L<AnyEvent::Handle::UDP>
		1110
		1111	Here be danger!
		1112
		1113	As Pauli would put it, "Not only is it not right, it's not even wrong!" -
		1114	there are so many things wrong with AnyEvent::Handle::UDP, most notably
		1115	it's use of a stream-based API with a protocol that isn't streamable, that
		1116	the only way to improve it is to delete it.
		1117
		1118	It features data corruption (but typically only under load) and general
		1119	confusion. On top, the author is not only clueless about UDP but also
		1120	fact-resistant - some gems of his understanding: "connect doesn't work
		1121	with UDP", "UDP packets are not IP packets", "UDP only has datagrams, not
		1122	packets", "I don't need to implement proper error checking as UDP doesn't
		1123	support error checking" and so on - he doesn't even understand what's
		1124	wrong with his module when it is explained to him.
		1125
995	=item L<AnyEvent::HTTP>	1126	=item L<AnyEvent::DBI>
996		1127
997	A simple-to-use HTTP library that is capable of making a lot of concurrent	1128	Executes L<DBI> requests asynchronously in a proxy process for you,
998	HTTP requests.	1129	notifying you in an event-bnased way when the operation is finished.
		1130
		1131	=item L<AnyEvent::AIO>
		1132
		1133	Truly asynchronous (as opposed to non-blocking) I/O, should be in the
		1134	toolbox of every event programmer. AnyEvent::AIO transparently fuses
		1135	L<IO::AIO> and AnyEvent together, giving AnyEvent access to event-based
		1136	file I/O, and much more.
999		1137
1000	=item L<AnyEvent::HTTPD>	1138	=item L<AnyEvent::HTTPD>
1001		1139
1002	Provides a simple web application server framework.	1140	A simple embedded webserver.
1003		1141
1004	=item L<AnyEvent::FastPing>	1142	=item L<AnyEvent::FastPing>
1005		1143
1006	The fastest ping in the west.	1144	The fastest ping in the west.
1007
1008	=item L<AnyEvent::DBI>
1009
1010	Executes L<DBI> requests asynchronously in a proxy process.
1011
1012	=item L<AnyEvent::AIO>
1013
1014	Truly asynchronous I/O, should be in the toolbox of every event
1015	programmer. AnyEvent::AIO transparently fuses L<IO::AIO> and AnyEvent
1016	together.
1017
1018	=item L<AnyEvent::BDB>
1019
1020	Truly asynchronous Berkeley DB access. AnyEvent::BDB transparently fuses
1021	L<BDB> and AnyEvent together.
1022
1023	=item L<AnyEvent::GPSD>
1024
1025	A non-blocking interface to gpsd, a daemon delivering GPS information.
1026
1027	=item L<AnyEvent::IRC>
1028
1029	AnyEvent based IRC client module family (replacing the older Net::IRC3).
1030
1031	=item L<AnyEvent::XMPP>
1032
1033	AnyEvent based XMPP (Jabber protocol) module family (replacing the older
1034	Net::XMPP2>.
1035
1036	=item L<AnyEvent::IGS>
1037
1038	A non-blocking interface to the Internet Go Server protocol (used by
1039	L<App::IGS>).
1040
1041	=item L<Net::FCP>
1042
1043	AnyEvent-based implementation of the Freenet Client Protocol, birthplace
1044	of AnyEvent.
1045
1046	=item L<Event::ExecFlow>
1047
1048	High level API for event-based execution flow control.
1049		1145
1050	=item L<Coro>	1146	=item L<Coro>
1051		1147
1052	Has special support for AnyEvent via L<Coro::AnyEvent>.	1148	Has special support for AnyEvent via L<Coro::AnyEvent>.
1053		1149
…		…
1057		1153
1058	package AnyEvent;	1154	package AnyEvent;
1059		1155
1060	# basically a tuned-down version of common::sense	1156	# basically a tuned-down version of common::sense
1061	sub common_sense {	1157	sub common_sense {
1062	# no warnings	1158	# from common:.sense 1.0
1063	${^WARNING_BITS} ^= ${^WARNING_BITS};	1159	${^WARNING_BITS} = "\xfc\x3f\x33\x00\x0f\xf3\xcf\xc0\xf3\xfc\x33\x00";
1064	# use strict vars subs	1160	# use strict vars subs - NO UTF-8, as Util.pm doesn't like this atm. (uts46data.pl)
1065	$^H |= 0x00000600;	1161	$^H |= 0x00000600;
1066	}	1162	}
1067		1163
1068	BEGIN { AnyEvent::common_sense }	1164	BEGIN { AnyEvent::common_sense }
1069		1165
1070	use Carp ();	1166	use Carp ();
1071		1167
1072	our $VERSION = 4.86;	1168	our $VERSION = '5.261';
1073	our $MODEL;	1169	our $MODEL;
1074		1170
1075	our $AUTOLOAD;	1171	our $AUTOLOAD;
1076	our @ISA;	1172	our @ISA;
1077		1173
1078	our @REGISTRY;	1174	our @REGISTRY;
1079		1175
1080	our $WIN32;
1081
1082	our $VERBOSE;	1176	our $VERBOSE;
1083		1177
1084	BEGIN {	1178	BEGIN {
1085	eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }";	1179	require "AnyEvent/constants.pl";
		1180
1086	eval "sub TAINT(){ " . (${^TAINT}*1) . " }";	1181	eval "sub TAINT (){" . (${^TAINT}*1) . "}";
1087		1182
1088	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}	1183	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}
1089	if ${^TAINT};	1184	if ${^TAINT};
1090		1185
1091	$VERBOSE = $ENV{PERL_ANYEVENT_VERBOSE}*1;	1186	$VERBOSE = $ENV{PERL_ANYEVENT_VERBOSE}*1;
…		…
1102	for reverse split /\s*,\s*/,	1197	for reverse split /\s*,\s*/,
1103	$ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";	1198	$ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";
1104	}	1199	}
1105		1200
1106	my @models = (	1201	my @models = (
1107	[EV:: => AnyEvent::Impl::EV::],	1202	[EV:: => AnyEvent::Impl::EV:: , 1],
1108	[Event:: => AnyEvent::Impl::Event::],
1109	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::],	1203	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl:: , 1],
1110	# everything below here will not be autoprobed	1204	# everything below here will not (normally) be autoprobed
1111	# as the pureperl backend should work everywhere	1205	# as the pureperl backend should work everywhere
1112	# and is usually faster	1206	# and is usually faster
		1207	[Event:: => AnyEvent::Impl::Event::, 1],
1113	[Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers	1208	[Glib:: => AnyEvent::Impl::Glib:: , 1], # becomes extremely slow with many watchers
1114	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy	1209	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
		1210	[Irssi:: => AnyEvent::Impl::Irssi::], # Irssi has a bogus "Event" package
1115	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles	1211	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
1116	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program	1212	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program
1117	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza	1213	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
1118	[Wx:: => AnyEvent::Impl::POE::],	1214	[Wx:: => AnyEvent::Impl::POE::],
1119	[Prima:: => AnyEvent::Impl::POE::],	1215	[Prima:: => AnyEvent::Impl::POE::],
1120	# IO::Async is just too broken - we would need workarounds for its	1216	# IO::Async is just too broken - we would need workarounds for its
1121	# byzantine signal and broken child handling, among others.	1217	# byzantine signal and broken child handling, among others.
1122	# IO::Async is rather hard to detect, as it doesn't have any	1218	# IO::Async is rather hard to detect, as it doesn't have any
1123	# obvious default class.	1219	# obvious default class.
1124	# [IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program	1220	[IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program
1125	# [IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program	1221	[IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program
1126	# [IO::Async::Notifier:: => AnyEvent::Impl::IOAsync::], # requires special main program	1222	[IO::Async::Notifier:: => AnyEvent::Impl::IOAsync::], # requires special main program
		1223	[AnyEvent::Impl::IOAsync:: => AnyEvent::Impl::IOAsync::], # requires special main program
1127	);	1224	);
1128		1225
1129	our %method = map +($_ => 1),	1226	our %method = map +($_ => 1),
1130	qw(io timer time now now_update signal child idle condvar one_event DESTROY);	1227	qw(io timer time now now_update signal child idle condvar one_event DESTROY);
1131		1228
1132	our @post_detect;	1229	our @post_detect;
1133		1230
1134	sub post_detect(&) {	1231	sub post_detect(&) {
1135	my ($cb) = @_;	1232	my ($cb) = @_;
1136		1233
1137	if ($MODEL) {
1138	$cb->();
1139
1140	1
1141	} else {
1142	push @post_detect, $cb;	1234	push @post_detect, $cb;
1143		1235
1144	defined wantarray	1236	defined wantarray
1145	? bless \$cb, "AnyEvent::Util::postdetect"	1237	? bless \$cb, "AnyEvent::Util::postdetect"
1146	: ()	1238	: ()
1147	}
1148	}	1239	}
1149		1240
1150	sub AnyEvent::Util::postdetect::DESTROY {	1241	sub AnyEvent::Util::postdetect::DESTROY {
1151	@post_detect = grep $_ != ${$_[0]}, @post_detect;	1242	@post_detect = grep $_ != ${$_[0]}, @post_detect;
1152	}	1243	}
1153		1244
1154	sub detect() {	1245	sub detect() {
		1246	# free some memory
		1247	*detect = sub () { $MODEL };
		1248
		1249	local $!; # for good measure
		1250	local $SIG{__DIE__};
		1251
		1252	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {
		1253	my $model = "AnyEvent::Impl::$1";
		1254	if (eval "require $model") {
		1255	$MODEL = $model;
		1256	warn "AnyEvent: loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.\n" if $VERBOSE >= 2;
		1257	} else {
		1258	warn "AnyEvent: unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@" if $VERBOSE;
		1259	}
		1260	}
		1261
		1262	# check for already loaded models
1155	unless ($MODEL) {	1263	unless ($MODEL) {
1156	local $SIG{__DIE__};	1264	for (@REGISTRY, @models) {
1157		1265	my ($package, $model) = @$_;
1158	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {	1266	if (${"$package\::VERSION"} > 0) {
1159	my $model = "AnyEvent::Impl::$1";
1160	if (eval "require $model") {	1267	if (eval "require $model") {
1161	$MODEL = $model;	1268	$MODEL = $model;
1162	warn "AnyEvent: loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.\n" if $VERBOSE >= 2;	1269	warn "AnyEvent: autodetected model '$model', using it.\n" if $VERBOSE >= 2;
1163	} else {	1270	last;
1164	warn "AnyEvent: unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@" if $VERBOSE;	1271	}
1165	}	1272	}
1166	}	1273	}
1167		1274
1168	# check for already loaded models
1169	unless ($MODEL) {	1275	unless ($MODEL) {
		1276	# try to autoload a model
1170	for (@REGISTRY, @models) {	1277	for (@REGISTRY, @models) {
1171	my ($package, $model) = @$_;	1278	my ($package, $model, $autoload) = @$_;
		1279	if (
		1280	$autoload
		1281	and eval "require $package"
1172	if (${"$package\::VERSION"} > 0) {	1282	and ${"$package\::VERSION"} > 0
1173	if (eval "require $model") {	1283	and eval "require $model"
		1284	) {
1174	$MODEL = $model;	1285	$MODEL = $model;
1175	warn "AnyEvent: autodetected model '$model', using it.\n" if $VERBOSE >= 2;	1286	warn "AnyEvent: autoloaded model '$model', using it.\n" if $VERBOSE >= 2;
1176	last;	1287	last;
1177	}
1178	}	1288	}
1179	}	1289	}
1180		1290
1181	unless ($MODEL) {
1182	# try to load a model
1183
1184	for (@REGISTRY, @models) {
1185	my ($package, $model) = @$_;
1186	if (eval "require $package"
1187	and ${"$package\::VERSION"} > 0
1188	and eval "require $model") {
1189	$MODEL = $model;
1190	warn "AnyEvent: autoprobed model '$model', using it.\n" if $VERBOSE >= 2;
1191	last;
1192	}
1193	}
1194
1195	$MODEL	1291	$MODEL
1196	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.\n";	1292	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.\n";
1197	}
1198	}	1293	}
1199
1200	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
1201
1202	unshift @ISA, $MODEL;
1203
1204	require AnyEvent::Strict if $ENV{PERL_ANYEVENT_STRICT};
1205
1206	(shift @post_detect)->() while @post_detect;
1207	}	1294	}
		1295
		1296	@models = (); # free probe data
		1297
		1298	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
		1299	unshift @ISA, $MODEL;
		1300
		1301	# now nuke some methods that are overriden by the backend.
		1302	# SUPER is not allowed.
		1303	for (qw(time signal child idle)) {
		1304	undef &{"AnyEvent::Base::$_"}
		1305	if defined &{"$MODEL\::$_"};
		1306	}
		1307
		1308	require AnyEvent::Strict if $ENV{PERL_ANYEVENT_STRICT};
		1309
		1310	(shift @post_detect)->() while @post_detect;
		1311
		1312	*post_detect = sub(&) {
		1313	shift->();
		1314
		1315	undef
		1316	};
1208		1317
1209	$MODEL	1318	$MODEL
1210	}	1319	}
1211		1320
1212	sub AUTOLOAD {	1321	sub AUTOLOAD {
1213	(my $func = $AUTOLOAD) =~ s/.*://;	1322	(my $func = $AUTOLOAD) =~ s/.*://;
1214		1323
1215	$method{$func}	1324	$method{$func}
1216	or Carp::croak "$func: not a valid method for AnyEvent objects";	1325	or Carp::croak "$func: not a valid AnyEvent class method";
1217		1326
1218	detect unless $MODEL;	1327	detect;
1219		1328
1220	my $class = shift;	1329	my $class = shift;
1221	$class->$func (@_);	1330	$class->$func (@_);
1222	}	1331	}
1223		1332
…		…
1236	# we assume CLOEXEC is already set by perl in all important cases	1345	# we assume CLOEXEC is already set by perl in all important cases
1237		1346
1238	($fh2, $rw)	1347	($fh2, $rw)
1239	}	1348	}
1240		1349
		1350	=head1 SIMPLIFIED AE API
		1351
		1352	Starting with version 5.0, AnyEvent officially supports a second, much
		1353	simpler, API that is designed to reduce the calling, typing and memory
		1354	overhead by using function call syntax and a fixed number of parameters.
		1355
		1356	See the L<AE> manpage for details.
		1357
		1358	=cut
		1359
		1360	package AE;
		1361
		1362	our $VERSION = $AnyEvent::VERSION;
		1363
		1364	# fall back to the main API by default - backends and AnyEvent::Base
		1365	# implementations can overwrite these.
		1366
		1367	sub io($$$) {
		1368	AnyEvent->io (fh => $_[0], poll => $_[1] ? "w" : "r", cb => $_[2])
		1369	}
		1370
		1371	sub timer($$$) {
		1372	AnyEvent->timer (after => $_[0], interval => $_[1], cb => $_[2])
		1373	}
		1374
		1375	sub signal($$) {
		1376	AnyEvent->signal (signal => $_[0], cb => $_[1])
		1377	}
		1378
		1379	sub child($$) {
		1380	AnyEvent->child (pid => $_[0], cb => $_[1])
		1381	}
		1382
		1383	sub idle($) {
		1384	AnyEvent->idle (cb => $_[0])
		1385	}
		1386
		1387	sub cv(;&) {
		1388	AnyEvent->condvar (@_ ? (cb => $_[0]) : ())
		1389	}
		1390
		1391	sub now() {
		1392	AnyEvent->now
		1393	}
		1394
		1395	sub now_update() {
		1396	AnyEvent->now_update
		1397	}
		1398
		1399	sub time() {
		1400	AnyEvent->time
		1401	}
		1402
1241	package AnyEvent::Base;	1403	package AnyEvent::Base;
1242		1404
1243	# default implementations for many methods	1405	# default implementations for many methods
1244		1406
1245	sub _time {	1407	sub time {
		1408	eval q{ # poor man's autoloading {}
1246	# probe for availability of Time::HiRes	1409	# probe for availability of Time::HiRes
1247	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {	1410	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {
1248	warn "AnyEvent: using Time::HiRes for sub-second timing accuracy.\n" if $VERBOSE >= 8;	1411	warn "AnyEvent: using Time::HiRes for sub-second timing accuracy.\n" if $VERBOSE >= 8;
1249	*_time = \&Time::HiRes::time;	1412	*AE::time = \&Time::HiRes::time;
1250	# if (eval "use POSIX (); (POSIX::times())...	1413	# if (eval "use POSIX (); (POSIX::times())...
1251	} else {	1414	} else {
1252	warn "AnyEvent: using built-in time(), WARNING, no sub-second resolution!\n" if $VERBOSE;	1415	warn "AnyEvent: using built-in time(), WARNING, no sub-second resolution!\n" if $VERBOSE;
1253	*_time = sub { time }; # epic fail	1416	*AE::time = sub (){ time }; # epic fail
		1417	}
		1418
		1419	*time = sub { AE::time }; # different prototypes
1254	}	1420	};
		1421	die if $@;
1255		1422
1256	&_time	1423	&time
1257	}	1424	}
1258		1425
1259	sub time { _time }	1426	*now = \&time;
1260	sub now { _time }	1427
1261	sub now_update { }	1428	sub now_update { }
1262		1429
1263	# default implementation for ->condvar	1430	# default implementation for ->condvar
1264		1431
1265	sub condvar {	1432	sub condvar {
		1433	eval q{ # poor man's autoloading {}
		1434	*condvar = sub {
1266	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"	1435	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"
		1436	};
		1437
		1438	*AE::cv = sub (;&) {
		1439	bless { @_ ? (_ae_cb => shift) : () }, "AnyEvent::CondVar"
		1440	};
		1441	};
		1442	die if $@;
		1443
		1444	&condvar
1267	}	1445	}
1268		1446
1269	# default implementation for ->signal	1447	# default implementation for ->signal
1270		1448
1271	our $HAVE_ASYNC_INTERRUPT;	1449	our $HAVE_ASYNC_INTERRUPT;
		1450
		1451	sub _have_async_interrupt() {
		1452	$HAVE_ASYNC_INTERRUPT = 1*(!$ENV{PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT}
		1453	&& eval "use Async::Interrupt 1.02 (); 1")
		1454	unless defined $HAVE_ASYNC_INTERRUPT;
		1455
		1456	$HAVE_ASYNC_INTERRUPT
		1457	}
		1458
1272	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);	1459	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);
1273	our (%SIG_ASY, %SIG_ASY_W);	1460	our (%SIG_ASY, %SIG_ASY_W);
1274	our ($SIG_COUNT, $SIG_TW);	1461	our ($SIG_COUNT, $SIG_TW);
1275		1462
1276	sub _signal_exec {
1277	$HAVE_ASYNC_INTERRUPT
1278	? $SIGPIPE_R->drain
1279	: sysread $SIGPIPE_R, my $dummy, 9;
1280
1281	while (%SIG_EV) {
1282	for (keys %SIG_EV) {
1283	delete $SIG_EV{$_};
1284	$_->() for values %{ $SIG_CB{$_} || {} };
1285	}
1286	}
1287	}
1288
1289	# install a dumym wakeupw atcher to reduce signal catching latency	1463	# install a dummy wakeup watcher to reduce signal catching latency
		1464	# used by Impls
1290	sub _sig_add() {	1465	sub _sig_add() {
1291	unless ($SIG_COUNT++) {	1466	unless ($SIG_COUNT++) {
1292	# try to align timer on a full-second boundary, if possible	1467	# try to align timer on a full-second boundary, if possible
1293	my $NOW = AnyEvent->now;	1468	my $NOW = AE::now;
1294		1469
1295	$SIG_TW = AnyEvent->timer (	1470	$SIG_TW = AE::timer
1296	after => $MAX_SIGNAL_LATENCY - ($NOW - int $NOW),	1471	$MAX_SIGNAL_LATENCY - ($NOW - int $NOW),
1297	interval => $MAX_SIGNAL_LATENCY,	1472	$MAX_SIGNAL_LATENCY,
1298	cb => sub { }, # just for the PERL_ASYNC_CHECK	1473	sub { } # just for the PERL_ASYNC_CHECK
1299	);	1474	;
1300	}	1475	}
1301	}	1476	}
1302		1477
1303	sub _sig_del {	1478	sub _sig_del {
1304	undef $SIG_TW	1479	undef $SIG_TW
1305	unless --$SIG_COUNT;	1480	unless --$SIG_COUNT;
1306	}	1481	}
1307		1482
		1483	our $_sig_name_init; $_sig_name_init = sub {
		1484	eval q{ # poor man's autoloading {}
		1485	undef $_sig_name_init;
		1486
		1487	if (_have_async_interrupt) {
		1488	*sig2num = \&Async::Interrupt::sig2num;
		1489	*sig2name = \&Async::Interrupt::sig2name;
		1490	} else {
		1491	require Config;
		1492
		1493	my %signame2num;
		1494	@signame2num{ split ' ', $Config::Config{sig_name} }
		1495	= split ' ', $Config::Config{sig_num};
		1496
		1497	my @signum2name;
		1498	@signum2name[values %signame2num] = keys %signame2num;
		1499
		1500	*sig2num = sub($) {
		1501	$_[0] > 0 ? shift : $signame2num{+shift}
		1502	};
		1503	*sig2name = sub ($) {
		1504	$_[0] > 0 ? $signum2name[+shift] : shift
		1505	};
		1506	}
		1507	};
		1508	die if $@;
		1509	};
		1510
		1511	sub sig2num ($) { &$_sig_name_init; &sig2num }
		1512	sub sig2name($) { &$_sig_name_init; &sig2name }
		1513
1308	sub _signal {	1514	sub signal {
1309	my (undef, %arg) = @_;	1515	eval q{ # poor man's autoloading {}
		1516	# probe for availability of Async::Interrupt
		1517	if (_have_async_interrupt) {
		1518	warn "AnyEvent: using Async::Interrupt for race-free signal handling.\n" if $VERBOSE >= 8;
1310		1519
1311	my $signal = uc $arg{signal}	1520	$SIGPIPE_R = new Async::Interrupt::EventPipe;
1312	or Carp::croak "required option 'signal' is missing";	1521	$SIG_IO = AE::io $SIGPIPE_R->fileno, 0, \&_signal_exec;
1313		1522
1314	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};	1523	} else {
		1524	warn "AnyEvent: using emulated perl signal handling with latency timer.\n" if $VERBOSE >= 8;
1315		1525
1316	if ($HAVE_ASYNC_INTERRUPT) {	1526	if (AnyEvent::WIN32) {
1317	# async::interrupt	1527	require AnyEvent::Util;
1318		1528
1319	$SIG_ASY{$signal} ||= do {	1529	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
1320	my $asy = new Async::Interrupt	1530	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R, 1) if $SIGPIPE_R;
1321	cb => sub { undef $SIG_EV{$signal} },	1531	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W, 1) if $SIGPIPE_W; # just in case
1322	signal => $signal,	1532	} else {
1323	pipe => [$SIGPIPE_R->filenos],	1533	pipe $SIGPIPE_R, $SIGPIPE_W;
		1534	fcntl $SIGPIPE_R, AnyEvent::F_SETFL, AnyEvent::O_NONBLOCK if $SIGPIPE_R;
		1535	fcntl $SIGPIPE_W, AnyEvent::F_SETFL, AnyEvent::O_NONBLOCK if $SIGPIPE_W; # just in case
		1536
		1537	# not strictly required, as $^F is normally 2, but let's make sure...
		1538	fcntl $SIGPIPE_R, AnyEvent::F_SETFD, AnyEvent::FD_CLOEXEC;
		1539	fcntl $SIGPIPE_W, AnyEvent::F_SETFD, AnyEvent::FD_CLOEXEC;
1324	;	1540	}
1325	$asy->pipe_autodrain (0);
1326		1541
1327	$asy	1542	$SIGPIPE_R
		1543	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";
		1544
		1545	$SIG_IO = AE::io $SIGPIPE_R, 0, \&_signal_exec;
		1546	}
		1547
		1548	*signal = $HAVE_ASYNC_INTERRUPT
		1549	? sub {
		1550	my (undef, %arg) = @_;
		1551
		1552	# async::interrupt
		1553	my $signal = sig2num $arg{signal};
		1554	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
		1555
		1556	$SIG_ASY{$signal} ||= new Async::Interrupt
		1557	cb => sub { undef $SIG_EV{$signal} },
		1558	signal => $signal,
		1559	pipe => [$SIGPIPE_R->filenos],
		1560	pipe_autodrain => 0,
		1561	;
		1562
		1563	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
		1564	}
		1565	: sub {
		1566	my (undef, %arg) = @_;
		1567
		1568	# pure perl
		1569	my $signal = sig2name $arg{signal};
		1570	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
		1571
		1572	$SIG{$signal} ||= sub {
		1573	local $!;
		1574	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;
		1575	undef $SIG_EV{$signal};
		1576	};
		1577
		1578	# can't do signal processing without introducing races in pure perl,
		1579	# so limit the signal latency.
		1580	_sig_add;
		1581
		1582	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
		1583	}
		1584	;
		1585
		1586	*AnyEvent::Base::signal::DESTROY = sub {
		1587	my ($signal, $cb) = @{$_[0]};
		1588
		1589	_sig_del;
		1590
		1591	delete $SIG_CB{$signal}{$cb};
		1592
		1593	$HAVE_ASYNC_INTERRUPT
		1594	? delete $SIG_ASY{$signal}
		1595	: # delete doesn't work with older perls - they then
		1596	# print weird messages, or just unconditionally exit
		1597	# instead of getting the default action.
		1598	undef $SIG{$signal}
		1599	unless keys %{ $SIG_CB{$signal} };
1328	};	1600	};
1329		1601
1330	} else {	1602	*_signal_exec = sub {
1331	# pure perl	1603	$HAVE_ASYNC_INTERRUPT
		1604	? $SIGPIPE_R->drain
		1605	: sysread $SIGPIPE_R, (my $dummy), 9;
1332		1606
1333	$SIG{$signal} ||= sub {	1607	while (%SIG_EV) {
1334	local $!;	1608	for (keys %SIG_EV) {
1335	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;	1609	delete $SIG_EV{$_};
1336	undef $SIG_EV{$signal};	1610	$_->() for values %{ $SIG_CB{$_} || {} };
		1611	}
		1612	}
1337	};	1613	};
1338
1339	# can't do signal processing without introducing races in pure perl,
1340	# so limit the signal latency.
1341	_sig_add;
1342	}	1614	};
		1615	die if $@;
1343		1616
1344	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
1345	}
1346
1347	sub signal {
1348	# probe for availability of Async::Interrupt
1349	if (!$ENV{PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT} && eval "use Async::Interrupt 0.6 (); 1") {
1350	warn "AnyEvent: using Async::Interrupt for race-free signal handling.\n" if $VERBOSE >= 8;
1351
1352	$HAVE_ASYNC_INTERRUPT = 1;
1353	$SIGPIPE_R = new Async::Interrupt::EventPipe;
1354	$SIG_IO = AnyEvent->io (fh => $SIGPIPE_R->fileno, poll => "r", cb => \&_signal_exec);
1355
1356	} else {
1357	warn "AnyEvent: using emulated perl signal handling with latency timer.\n" if $VERBOSE >= 8;
1358
1359	require Fcntl;
1360
1361	if (AnyEvent::WIN32) {
1362	require AnyEvent::Util;
1363
1364	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
1365	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R) if $SIGPIPE_R;
1366	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W) if $SIGPIPE_W; # just in case
1367	} else {
1368	pipe $SIGPIPE_R, $SIGPIPE_W;
1369	fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R;
1370	fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case
1371
1372	# not strictly required, as $^F is normally 2, but let's make sure...
1373	fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
1374	fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
1375	}
1376
1377	$SIGPIPE_R
1378	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";
1379
1380	$SIG_IO = AnyEvent->io (fh => $SIGPIPE_R, poll => "r", cb => \&_signal_exec);
1381	}
1382
1383	*signal = \&_signal;
1384	&signal	1617	&signal
1385	}
1386
1387	sub AnyEvent::Base::signal::DESTROY {
1388	my ($signal, $cb) = @{$_[0]};
1389
1390	_sig_del;
1391
1392	delete $SIG_CB{$signal}{$cb};
1393
1394	$HAVE_ASYNC_INTERRUPT
1395	? delete $SIG_ASY{$signal}
1396	: # delete doesn't work with older perls - they then
1397	# print weird messages, or just unconditionally exit
1398	# instead of getting the default action.
1399	undef $SIG{$signal}
1400	unless keys %{ $SIG_CB{$signal} };
1401	}	1618	}
1402		1619
1403	# default implementation for ->child	1620	# default implementation for ->child
1404		1621
1405	our %PID_CB;	1622	our %PID_CB;
1406	our $CHLD_W;	1623	our $CHLD_W;
1407	our $CHLD_DELAY_W;	1624	our $CHLD_DELAY_W;
1408	our $WNOHANG;	1625	our $WNOHANG;
1409		1626
1410	sub _sigchld {	1627	# used by many Impl's
1411	while (0 < (my $pid = waitpid -1, $WNOHANG)) {	1628	sub _emit_childstatus($$) {
1412	$_->($pid, $?)	1629	my (undef, $rpid, $rstatus) = @_;
		1630
		1631	$_->($rpid, $rstatus)
1413	for values %{ $PID_CB{$pid} || {} },	1632	for values %{ $PID_CB{$rpid} || {} },
1414	values %{ $PID_CB{0} || {} };	1633	values %{ $PID_CB{0} || {} };
1415	}
1416	}	1634	}
1417		1635
1418	sub child {	1636	sub child {
		1637	eval q{ # poor man's autoloading {}
		1638	*_sigchld = sub {
		1639	my $pid;
		1640
		1641	AnyEvent->_emit_childstatus ($pid, $?)
		1642	while ($pid = waitpid -1, $WNOHANG) > 0;
		1643	};
		1644
		1645	*child = sub {
1419	my (undef, %arg) = @_;	1646	my (undef, %arg) = @_;
1420		1647
1421	defined (my $pid = $arg{pid} + 0)	1648	defined (my $pid = $arg{pid} + 0)
1422	or Carp::croak "required option 'pid' is missing";	1649	or Carp::croak "required option 'pid' is missing";
1423		1650
1424	$PID_CB{$pid}{$arg{cb}} = $arg{cb};	1651	$PID_CB{$pid}{$arg{cb}} = $arg{cb};
1425		1652
1426	# WNOHANG is almost cetrainly 1 everywhere	1653	# WNOHANG is almost cetrainly 1 everywhere
1427	$WNOHANG ||= $^O =~ /^(?:openbsd|netbsd|linux|freebsd|cygwin|MSWin32)$/	1654	$WNOHANG ||= $^O =~ /^(?:openbsd|netbsd|linux|freebsd|cygwin|MSWin32)$/
1428	? 1	1655	? 1
1429	: eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1;	1656	: eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1;
1430		1657
1431	unless ($CHLD_W) {	1658	unless ($CHLD_W) {
1432	$CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld);	1659	$CHLD_W = AE::signal CHLD => \&_sigchld;
1433	# child could be a zombie already, so make at least one round	1660	# child could be a zombie already, so make at least one round
1434	&_sigchld;	1661	&_sigchld;
1435	}	1662	}
1436		1663
1437	bless [$pid, $arg{cb}], "AnyEvent::Base::child"	1664	bless [$pid, $arg{cb}], "AnyEvent::Base::child"
1438	}	1665	};
1439		1666
1440	sub AnyEvent::Base::child::DESTROY {	1667	*AnyEvent::Base::child::DESTROY = sub {
1441	my ($pid, $cb) = @{$_[0]};	1668	my ($pid, $cb) = @{$_[0]};
1442		1669
1443	delete $PID_CB{$pid}{$cb};	1670	delete $PID_CB{$pid}{$cb};
1444	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };	1671	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };
1445		1672
1446	undef $CHLD_W unless keys %PID_CB;	1673	undef $CHLD_W unless keys %PID_CB;
		1674	};
		1675	};
		1676	die if $@;
		1677
		1678	&child
1447	}	1679	}
1448		1680
1449	# idle emulation is done by simply using a timer, regardless	1681	# idle emulation is done by simply using a timer, regardless
1450	# of whether the process is idle or not, and not letting	1682	# of whether the process is idle or not, and not letting
1451	# the callback use more than 50% of the time.	1683	# the callback use more than 50% of the time.
1452	sub idle {	1684	sub idle {
		1685	eval q{ # poor man's autoloading {}
		1686	*idle = sub {
1453	my (undef, %arg) = @_;	1687	my (undef, %arg) = @_;
1454		1688
1455	my ($cb, $w, $rcb) = $arg{cb};	1689	my ($cb, $w, $rcb) = $arg{cb};
1456		1690
1457	$rcb = sub {	1691	$rcb = sub {
1458	if ($cb) {	1692	if ($cb) {
1459	$w = _time;	1693	$w = _time;
1460	&$cb;	1694	&$cb;
1461	$w = _time - $w;	1695	$w = _time - $w;
1462		1696
1463	# never use more then 50% of the time for the idle watcher,	1697	# never use more then 50% of the time for the idle watcher,
1464	# within some limits	1698	# within some limits
1465	$w = 0.0001 if $w < 0.0001;	1699	$w = 0.0001 if $w < 0.0001;
1466	$w = 5 if $w > 5;	1700	$w = 5 if $w > 5;
1467		1701
1468	$w = AnyEvent->timer (after => $w, cb => $rcb);	1702	$w = AE::timer $w, 0, $rcb;
1469	} else {	1703	} else {
1470	# clean up...	1704	# clean up...
1471	undef $w;	1705	undef $w;
1472	undef $rcb;	1706	undef $rcb;
		1707	}
		1708	};
		1709
		1710	$w = AE::timer 0.05, 0, $rcb;
		1711
		1712	bless \\$cb, "AnyEvent::Base::idle"
1473	}	1713	};
		1714
		1715	*AnyEvent::Base::idle::DESTROY = sub {
		1716	undef $${$_[0]};
		1717	};
1474	};	1718	};
		1719	die if $@;
1475		1720
1476	$w = AnyEvent->timer (after => 0.05, cb => $rcb);	1721	&idle
1477
1478	bless \\$cb, "AnyEvent::Base::idle"
1479	}
1480
1481	sub AnyEvent::Base::idle::DESTROY {
1482	undef $${$_[0]};
1483	}	1722	}
1484		1723
1485	package AnyEvent::CondVar;	1724	package AnyEvent::CondVar;
1486		1725
1487	our @ISA = AnyEvent::CondVar::Base::;	1726	our @ISA = AnyEvent::CondVar::Base::;
…		…
1535	Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak};	1774	Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak};
1536	wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0]	1775	wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0]
1537	}	1776	}
1538		1777
1539	sub cb {	1778	sub cb {
1540	$_[0]{_ae_cb} = $_[1] if @_ > 1;	1779	my $cv = shift;
		1780
		1781	@_
		1782	and $cv->{_ae_cb} = shift
		1783	and $cv->{_ae_sent}
		1784	and (delete $cv->{_ae_cb})->($cv);
		1785
1541	$_[0]{_ae_cb}	1786	$cv->{_ae_cb}
1542	}	1787	}
1543		1788
1544	sub begin {	1789	sub begin {
1545	++$_[0]{_ae_counter};	1790	++$_[0]{_ae_counter};
1546	$_[0]{_ae_end_cb} = $_[1] if @_ > 1;	1791	$_[0]{_ae_end_cb} = $_[1] if @_ > 1;
…		…
1755	warn "read: $input\n"; # output what has been read	2000	warn "read: $input\n"; # output what has been read
1756	$cv->send if $input =~ /^q/i; # quit program if /^q/i	2001	$cv->send if $input =~ /^q/i; # quit program if /^q/i
1757	},	2002	},
1758	);	2003	);
1759		2004
1760	my $time_watcher; # can only be used once
1761
1762	sub new_timer {
1763	$timer = AnyEvent->timer (after => 1, cb => sub {	2005	my $time_watcher = AnyEvent->timer (after => 1, interval => 1, cb => sub {
1764	warn "timeout\n"; # print 'timeout' about every second	2006	warn "timeout\n"; # print 'timeout' at most every second
1765	&new_timer; # and restart the time
1766	});	2007	});
1767	}
1768
1769	new_timer; # create first timer
1770		2008
1771	$cv->recv; # wait until user enters /^q/i	2009	$cv->recv; # wait until user enters /^q/i
1772		2010
1773	=head1 REAL-WORLD EXAMPLE	2011	=head1 REAL-WORLD EXAMPLE
1774		2012
…		…
1847		2085
1848	The actual code goes further and collects all errors (C<die>s, exceptions)	2086	The actual code goes further and collects all errors (C<die>s, exceptions)
1849	that occurred during request processing. The C<result> method detects	2087	that occurred during request processing. The C<result> method detects
1850	whether an exception as thrown (it is stored inside the $txn object)	2088	whether an exception as thrown (it is stored inside the $txn object)
1851	and just throws the exception, which means connection errors and other	2089	and just throws the exception, which means connection errors and other
1852	problems get reported tot he code that tries to use the result, not in a	2090	problems get reported to the code that tries to use the result, not in a
1853	random callback.	2091	random callback.
1854		2092
1855	All of this enables the following usage styles:	2093	All of this enables the following usage styles:
1856		2094
1857	1. Blocking:	2095	1. Blocking:
…		…
1905	through AnyEvent. The benchmark creates a lot of timers (with a zero	2143	through AnyEvent. The benchmark creates a lot of timers (with a zero
1906	timeout) and I/O watchers (watching STDOUT, a pty, to become writable,	2144	timeout) and I/O watchers (watching STDOUT, a pty, to become writable,
1907	which it is), lets them fire exactly once and destroys them again.	2145	which it is), lets them fire exactly once and destroys them again.
1908		2146
1909	Source code for this benchmark is found as F<eg/bench> in the AnyEvent	2147	Source code for this benchmark is found as F<eg/bench> in the AnyEvent
1910	distribution.	2148	distribution. It uses the L<AE> interface, which makes a real difference
		2149	for the EV and Perl backends only.
1911		2150
1912	=head3 Explanation of the columns	2151	=head3 Explanation of the columns
1913		2152
1914	I<watcher> is the number of event watchers created/destroyed. Since	2153	I<watcher> is the number of event watchers created/destroyed. Since
1915	different event models feature vastly different performances, each event	2154	different event models feature vastly different performances, each event
…		…
1936	watcher.	2175	watcher.
1937		2176
1938	=head3 Results	2177	=head3 Results
1939		2178
1940	name watchers bytes create invoke destroy comment	2179	name watchers bytes create invoke destroy comment
1941	EV/EV 400000 224 0.47 0.35 0.27 EV native interface	2180	EV/EV 100000 223 0.47 0.43 0.27 EV native interface
1942	EV/Any 100000 224 2.88 0.34 0.27 EV + AnyEvent watchers	2181	EV/Any 100000 223 0.48 0.42 0.26 EV + AnyEvent watchers
1943	CoroEV/Any 100000 224 2.85 0.35 0.28 coroutines + Coro::Signal	2182	Coro::EV/Any 100000 223 0.47 0.42 0.26 coroutines + Coro::Signal
1944	Perl/Any 100000 452 4.13 0.73 0.95 pure perl implementation	2183	Perl/Any 100000 431 2.70 0.74 0.92 pure perl implementation
1945	Event/Event 16000 517 32.20 31.80 0.81 Event native interface	2184	Event/Event 16000 516 31.16 31.84 0.82 Event native interface
1946	Event/Any 16000 590 35.85 31.55 1.06 Event + AnyEvent watchers	2185	Event/Any 16000 1203 42.61 34.79 1.80 Event + AnyEvent watchers
1947	IOAsync/Any 16000 989 38.10 32.77 11.13 via IO::Async::Loop::IO_Poll	2186	IOAsync/Any 16000 1911 41.92 27.45 16.81 via IO::Async::Loop::IO_Poll
1948	IOAsync/Any 16000 990 37.59 29.50 10.61 via IO::Async::Loop::Epoll	2187	IOAsync/Any 16000 1726 40.69 26.37 15.25 via IO::Async::Loop::Epoll
1949	Glib/Any 16000 1357 102.33 12.31 51.00 quadratic behaviour	2188	Glib/Any 16000 1118 89.00 12.57 51.17 quadratic behaviour
1950	Tk/Any 2000 1860 27.20 66.31 14.00 SEGV with >> 2000 watchers	2189	Tk/Any 2000 1346 20.96 10.75 8.00 SEGV with >> 2000 watchers
1951	POE/Event 2000 6328 109.99 751.67 14.02 via POE::Loop::Event	2190	POE/Any 2000 6951 108.97 795.32 14.24 via POE::Loop::Event
1952	POE/Select 2000 6027 94.54 809.13 579.80 via POE::Loop::Select	2191	POE/Any 2000 6648 94.79 774.40 575.51 via POE::Loop::Select
1953		2192
1954	=head3 Discussion	2193	=head3 Discussion
1955		2194
1956	The benchmark does I<not> measure scalability of the event loop very	2195	The benchmark does I<not> measure scalability of the event loop very
1957	well. For example, a select-based event loop (such as the pure perl one)	2196	well. For example, a select-based event loop (such as the pure perl one)
…		…
1969	benchmark machine, handling an event takes roughly 1600 CPU cycles with	2208	benchmark machine, handling an event takes roughly 1600 CPU cycles with
1970	EV, 3100 CPU cycles with AnyEvent's pure perl loop and almost 3000000 CPU	2209	EV, 3100 CPU cycles with AnyEvent's pure perl loop and almost 3000000 CPU
1971	cycles with POE.	2210	cycles with POE.
1972		2211
1973	C<EV> is the sole leader regarding speed and memory use, which are both	2212	C<EV> is the sole leader regarding speed and memory use, which are both
1974	maximal/minimal, respectively. Even when going through AnyEvent, it uses	2213	maximal/minimal, respectively. When using the L<AE> API there is zero
		2214	overhead (when going through the AnyEvent API create is about 5-6 times
		2215	slower, with other times being equal, so still uses far less memory than
1975	far less memory than any other event loop and is still faster than Event	2216	any other event loop and is still faster than Event natively).
1976	natively.
1977		2217
1978	The pure perl implementation is hit in a few sweet spots (both the	2218	The pure perl implementation is hit in a few sweet spots (both the
1979	constant timeout and the use of a single fd hit optimisations in the perl	2219	constant timeout and the use of a single fd hit optimisations in the perl
1980	interpreter and the backend itself). Nevertheless this shows that it	2220	interpreter and the backend itself). Nevertheless this shows that it
1981	adds very little overhead in itself. Like any select-based backend its	2221	adds very little overhead in itself. Like any select-based backend its
…		…
2055	In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100	2295	In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100
2056	(1%) are active. This mirrors the activity of large servers with many	2296	(1%) are active. This mirrors the activity of large servers with many
2057	connections, most of which are idle at any one point in time.	2297	connections, most of which are idle at any one point in time.
2058		2298
2059	Source code for this benchmark is found as F<eg/bench2> in the AnyEvent	2299	Source code for this benchmark is found as F<eg/bench2> in the AnyEvent
2060	distribution.	2300	distribution. It uses the L<AE> interface, which makes a real difference
		2301	for the EV and Perl backends only.
2061		2302
2062	=head3 Explanation of the columns	2303	=head3 Explanation of the columns
2063		2304
2064	I<sockets> is the number of sockets, and twice the number of "servers" (as	2305	I<sockets> is the number of sockets, and twice the number of "servers" (as
2065	each server has a read and write socket end).	2306	each server has a read and write socket end).
…		…
2073	a new one that moves the timeout into the future.	2314	a new one that moves the timeout into the future.
2074		2315
2075	=head3 Results	2316	=head3 Results
2076		2317
2077	name sockets create request	2318	name sockets create request
2078	EV 20000 69.01 11.16	2319	EV 20000 62.66 7.99
2079	Perl 20000 73.32 35.87	2320	Perl 20000 68.32 32.64
2080	IOAsync 20000 157.00 98.14 epoll	2321	IOAsync 20000 174.06 101.15 epoll
2081	IOAsync 20000 159.31 616.06 poll	2322	IOAsync 20000 174.67 610.84 poll
2082	Event 20000 212.62 257.32	2323	Event 20000 202.69 242.91
2083	Glib 20000 651.16 1896.30	2324	Glib 20000 557.01 1689.52
2084	POE 20000 349.67 12317.24 uses POE::Loop::Event	2325	POE 20000 341.54 12086.32 uses POE::Loop::Event
2085		2326
2086	=head3 Discussion	2327	=head3 Discussion
2087		2328
2088	This benchmark I<does> measure scalability and overall performance of the	2329	This benchmark I<does> measure scalability and overall performance of the
2089	particular event loop.	2330	particular event loop.
…		…
2215	As you can see, the AnyEvent + EV combination even beats the	2456	As you can see, the AnyEvent + EV combination even beats the
2216	hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl	2457	hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl
2217	backend easily beats IO::Lambda and POE.	2458	backend easily beats IO::Lambda and POE.
2218		2459
2219	And even the 100% non-blocking version written using the high-level (and	2460	And even the 100% non-blocking version written using the high-level (and
2220	slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda by a	2461	slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda
2221	large margin, even though it does all of DNS, tcp-connect and socket I/O	2462	higher level ("unoptimised") abstractions by a large margin, even though
2222	in a non-blocking way.	2463	it does all of DNS, tcp-connect and socket I/O in a non-blocking way.
2223		2464
2224	The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and	2465	The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and
2225	F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are	2466	F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are
2226	part of the IO::lambda distribution and were used without any changes.	2467	part of the IO::Lambda distribution and were used without any changes.
2227		2468
2228		2469
2229	=head1 SIGNALS	2470	=head1 SIGNALS
2230		2471
2231	AnyEvent currently installs handlers for these signals:	2472	AnyEvent currently installs handlers for these signals:
…		…
2273	it's built-in modules) are required to use it.	2514	it's built-in modules) are required to use it.
2274		2515
2275	That does not mean that AnyEvent won't take advantage of some additional	2516	That does not mean that AnyEvent won't take advantage of some additional
2276	modules if they are installed.	2517	modules if they are installed.
2277		2518
2278	This section epxlains which additional modules will be used, and how they	2519	This section explains which additional modules will be used, and how they
2279	affect AnyEvent's operetion.	2520	affect AnyEvent's operation.
2280		2521
2281	=over 4	2522	=over 4
2282		2523
2283	=item L<Async::Interrupt>	2524	=item L<Async::Interrupt>
2284		2525
…		…
2289	catch the signals) with some delay (default is 10 seconds, look for	2530	catch the signals) with some delay (default is 10 seconds, look for
2290	C<$AnyEvent::MAX_SIGNAL_LATENCY>).	2531	C<$AnyEvent::MAX_SIGNAL_LATENCY>).
2291		2532
2292	If this module is available, then it will be used to implement signal	2533	If this module is available, then it will be used to implement signal
2293	catching, which means that signals will not be delayed, and the event loop	2534	catching, which means that signals will not be delayed, and the event loop
2294	will not be interrupted regularly, which is more efficient (And good for	2535	will not be interrupted regularly, which is more efficient (and good for
2295	battery life on laptops).	2536	battery life on laptops).
2296		2537
2297	This affects not just the pure-perl event loop, but also other event loops	2538	This affects not just the pure-perl event loop, but also other event loops
2298	that have no signal handling on their own (e.g. Glib, Tk, Qt).	2539	that have no signal handling on their own (e.g. Glib, Tk, Qt).
2299		2540
…		…
2311	automatic timer adjustments even when no monotonic clock is available,	2552	automatic timer adjustments even when no monotonic clock is available,
2312	can take avdantage of advanced kernel interfaces such as C<epoll> and	2553	can take avdantage of advanced kernel interfaces such as C<epoll> and
2313	C<kqueue>, and is the fastest backend I<by far>. You can even embed	2554	C<kqueue>, and is the fastest backend I<by far>. You can even embed
2314	L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>).	2555	L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>).
2315		2556
		2557	If you only use backends that rely on another event loop (e.g. C<Tk>),
		2558	then this module will do nothing for you.
		2559
2316	=item L<Guard>	2560	=item L<Guard>
2317		2561
2318	The guard module, when used, will be used to implement	2562	The guard module, when used, will be used to implement
2319	C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a	2563	C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a
2320	lot less memory), but otherwise doesn't affect guard operation much. It is	2564	lot less memory), but otherwise doesn't affect guard operation much. It is
2321	purely used for performance.	2565	purely used for performance.
2322		2566
2323	=item L<JSON> and L<JSON::XS>	2567	=item L<JSON> and L<JSON::XS>
2324		2568
2325	This module is required when you want to read or write JSON data via	2569	One of these modules is required when you want to read or write JSON data
2326	L<AnyEvent::Handle>. It is also written in pure-perl, but can take	2570	via L<AnyEvent::Handle>. L<JSON> is also written in pure-perl, but can take
2327	advantage of the ultra-high-speed L<JSON::XS> module when it is installed.	2571	advantage of the ultra-high-speed L<JSON::XS> module when it is installed.
2328
2329	In fact, L<AnyEvent::Handle> will use L<JSON::XS> by default if it is
2330	installed.
2331		2572
2332	=item L<Net::SSLeay>	2573	=item L<Net::SSLeay>
2333		2574
2334	Implementing TLS/SSL in Perl is certainly interesting, but not very	2575	Implementing TLS/SSL in Perl is certainly interesting, but not very
2335	worthwhile: If this module is installed, then L<AnyEvent::Handle> (with	2576	worthwhile: If this module is installed, then L<AnyEvent::Handle> (with
…		…
2346		2587
2347		2588
2348	=head1 FORK	2589	=head1 FORK
2349		2590
2350	Most event libraries are not fork-safe. The ones who are usually are	2591	Most event libraries are not fork-safe. The ones who are usually are
2351	because they rely on inefficient but fork-safe C<select> or C<poll>	2592	because they rely on inefficient but fork-safe C<select> or C<poll> calls
2352	calls. Only L<EV> is fully fork-aware.	2593	- higher performance APIs such as BSD's kqueue or the dreaded Linux epoll
		2594	are usually badly thought-out hacks that are incompatible with fork in
		2595	one way or another. Only L<EV> is fully fork-aware and ensures that you
		2596	continue event-processing in both parent and child (or both, if you know
		2597	what you are doing).
		2598
		2599	This means that, in general, you cannot fork and do event processing in
		2600	the child if the event library was initialised before the fork (which
		2601	usually happens when the first AnyEvent watcher is created, or the library
		2602	is loaded).
2353		2603
2354	If you have to fork, you must either do so I<before> creating your first	2604	If you have to fork, you must either do so I<before> creating your first
2355	watcher OR you must not use AnyEvent at all in the child OR you must do	2605	watcher OR you must not use AnyEvent at all in the child OR you must do
2356	something completely out of the scope of AnyEvent.	2606	something completely out of the scope of AnyEvent.
		2607
		2608	The problem of doing event processing in the parent I<and> the child
		2609	is much more complicated: even for backends that I<are> fork-aware or
		2610	fork-safe, their behaviour is not usually what you want: fork clones all
		2611	watchers, that means all timers, I/O watchers etc. are active in both
		2612	parent and child, which is almost never what you want. USing C<exec>
		2613	to start worker children from some kind of manage rprocess is usually
		2614	preferred, because it is much easier and cleaner, at the expense of having
		2615	to have another binary.
2357		2616
2358		2617
2359	=head1 SECURITY CONSIDERATIONS	2618	=head1 SECURITY CONSIDERATIONS
2360		2619
2361	AnyEvent can be forced to load any event model via	2620	AnyEvent can be forced to load any event model via
…		…
2399	L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.	2658	L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.
2400		2659
2401	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,	2660	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,
2402	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,	2661	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,
2403	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,	2662	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,
2404	L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>.	2663	L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>, L<Anyevent::Impl::Irssi>.
2405		2664
2406	Non-blocking file handles, sockets, TCP clients and	2665	Non-blocking file handles, sockets, TCP clients and
2407	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.	2666	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.
2408		2667
2409	Asynchronous DNS: L<AnyEvent::DNS>.	2668	Asynchronous DNS: L<AnyEvent::DNS>.

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