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Revision 1.250 by root, Mon Jul 20 07:12:38 2009 UTC vs.
Revision 1.329 by root, Sun Jul 11 05:44:22 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?
…		…
135	use AnyEvent;	138	use AnyEvent;
136		139
137	# .. AnyEvent will likely default to Tk	140	# .. AnyEvent will likely default to Tk
138		141
139	The I<likely> means that, if any module loads another event model and	142	The I<likely> means that, if any module loads another event model and
140	starts using it, all bets are off. Maybe you should tell their authors to	143	starts using it, all bets are off - this case should be very rare though,
141	use AnyEvent so their modules work together with others seamlessly...	144	as very few modules hardcode event loops without announcing this very
		145	loudly.
142		146
143	The pure-perl implementation of AnyEvent is called	147	The pure-perl implementation of AnyEvent is called
144	C<AnyEvent::Impl::Perl>. Like other event modules you can load it	148	C<AnyEvent::Impl::Perl>. Like other event modules you can load it
145	explicitly and enjoy the high availability of that event loop :)	149	explicitly and enjoy the high availability of that event loop :)
146		150
…		…
180	Note that C<my $w; $w => combination. This is necessary because in Perl,	184	Note that C<my $w; $w => combination. This is necessary because in Perl,
181	my variables are only visible after the statement in which they are	185	my variables are only visible after the statement in which they are
182	declared.	186	declared.
183		187
184	=head2 I/O WATCHERS	188	=head2 I/O WATCHERS
		189
		190	$w = AnyEvent->io (
		191	fh => <filehandle_or_fileno>,
		192	poll => <"r" or "w">,
		193	cb => <callback>,
		194	);
185		195
186	You can create an I/O watcher by calling the C<< AnyEvent->io >> method	196	You can create an I/O watcher by calling the C<< AnyEvent->io >> method
187	with the following mandatory key-value pairs as arguments:	197	with the following mandatory key-value pairs as arguments:
188		198
189	C<fh> is the Perl I<file handle> (or a naked file descriptor) to watch	199	C<fh> is the Perl I<file handle> (or a naked file descriptor) to watch
…		…
219	undef $w;	229	undef $w;
220	});	230	});
221		231
222	=head2 TIME WATCHERS	232	=head2 TIME WATCHERS
223		233
		234	$w = AnyEvent->timer (after => <seconds>, cb => <callback>);
		235
		236	$w = AnyEvent->timer (
		237	after => <fractional_seconds>,
		238	interval => <fractional_seconds>,
		239	cb => <callback>,
		240	);
		241
224	You can create a time watcher by calling the C<< AnyEvent->timer >>	242	You can create a time watcher by calling the C<< AnyEvent->timer >>
225	method with the following mandatory arguments:	243	method with the following mandatory arguments:
226		244
227	C<after> specifies after how many seconds (fractional values are	245	C<after> specifies after how many seconds (fractional values are
228	supported) the callback should be invoked. C<cb> is the callback to invoke	246	supported) the callback should be invoked. C<cb> is the callback to invoke
…		…
349	might affect timers and time-outs.	367	might affect timers and time-outs.
350		368
351	When this is the case, you can call this method, which will update the	369	When this is the case, you can call this method, which will update the
352	event loop's idea of "current time".	370	event loop's idea of "current time".
353		371
		372	A typical example would be a script in a web server (e.g. C<mod_perl>) -
		373	when mod_perl executes the script, then the event loop will have the wrong
		374	idea about the "current time" (being potentially far in the past, when the
		375	script ran the last time). In that case you should arrange a call to C<<
		376	AnyEvent->now_update >> each time the web server process wakes up again
		377	(e.g. at the start of your script, or in a handler).
		378
354	Note that updating the time I<might> cause some events to be handled.	379	Note that updating the time I<might> cause some events to be handled.
355		380
356	=back	381	=back
357		382
358	=head2 SIGNAL WATCHERS	383	=head2 SIGNAL WATCHERS
		384
		385	$w = AnyEvent->signal (signal => <uppercase_signal_name>, cb => <callback>);
359		386
360	You can watch for signals using a signal watcher, C<signal> is the signal	387	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	388	I<name> in uppercase and without any C<SIG> prefix, C<cb> is the Perl
362	callback to be invoked whenever a signal occurs.	389	callback to be invoked whenever a signal occurs.
363		390
…		…
380		407
381	Example: exit on SIGINT	408	Example: exit on SIGINT
382		409
383	my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });	410	my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });
384		411
		412	=head3 Restart Behaviour
		413
		414	While restart behaviour is up to the event loop implementation, most will
		415	not restart syscalls (that includes L<Async::Interrupt> and AnyEvent's
		416	pure perl implementation).
		417
		418	=head3 Safe/Unsafe Signals
		419
		420	Perl signals can be either "safe" (synchronous to opcode handling) or
		421	"unsafe" (asynchronous) - the former might get delayed indefinitely, the
		422	latter might corrupt your memory.
		423
		424	AnyEvent signal handlers are, in addition, synchronous to the event loop,
		425	i.e. they will not interrupt your running perl program but will only be
		426	called as part of the normal event handling (just like timer, I/O etc.
		427	callbacks, too).
		428
385	=head3 Signal Races, Delays and Workarounds	429	=head3 Signal Races, Delays and Workarounds
386		430
387	Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support attaching	431	Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support attaching
388	callbacks to signals in a generic way, which is a pity, as you cannot do	432	callbacks to signals in a generic way, which is a pity, as you cannot
389	race-free signal handling in perl. AnyEvent will try to do it's best, but	433	do race-free signal handling in perl, requiring C libraries for
		434	this. AnyEvent will try to do it's best, which means in some cases,
390	in some cases, signals will be delayed. The maximum time a signal might	435	signals will be delayed. The maximum time a signal might be delayed is
391	be delayed is specified in C<$AnyEvent::MAX_SIGNAL_LATENCY> (default: 10	436	specified in C<$AnyEvent::MAX_SIGNAL_LATENCY> (default: 10 seconds). This
392	seconds). This variable can be changed only before the first signal	437	variable can be changed only before the first signal watcher is created,
393	watcher is created, and should be left alone otherwise. Higher values	438	and should be left alone otherwise. This variable determines how often
		439	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	440	will cause fewer spurious wake-ups, which is better for power and CPU
		441	saving.
		442
395	saving. All these problems can be avoided by installing the optional	443	All these problems can be avoided by installing the optional
396	L<Async::Interrupt> module. This will not work with inherently broken	444	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>	445	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	446	(and not with L<POE> currently, as POE does it's own workaround with
399	those, you just have to suffer the delays.	447	one-second latency). For those, you just have to suffer the delays.
400		448
401	=head2 CHILD PROCESS WATCHERS	449	=head2 CHILD PROCESS WATCHERS
402		450
		451	$w = AnyEvent->child (pid => <process id>, cb => <callback>);
		452
403	You can also watch on a child process exit and catch its exit status.	453	You can also watch on a child process exit and catch its exit status.
404		454
405	The child process is specified by the C<pid> argument (if set to C<0>, it	455	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	456	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	457	croak). The watcher will be triggered only when the child process has
408	any trace events (stopped/continued).	458	finished and an exit status is available, not on any trace events
		459	(stopped/continued).
409		460
410	The callback will be called with the pid and exit status (as returned by	461	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	462	waitpid), so unlike other watcher types, you I<can> rely on child watcher
412	callback arguments.	463	callback arguments.
413		464
…		…
454	# do something else, then wait for process exit	505	# do something else, then wait for process exit
455	$done->recv;	506	$done->recv;
456		507
457	=head2 IDLE WATCHERS	508	=head2 IDLE WATCHERS
458		509
459	Sometimes there is a need to do something, but it is not so important	510	$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		511
464	Idle watchers ideally get invoked when the event loop has nothing	512	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	513	either the watcher is destroyed or new events have been detected.
466	events. Instead of blocking, the idle watcher is invoked.
467		514
468	Most event loops unfortunately do not really support idle watchers (only	515	Idle watchers are useful when there is a need to do something, but it
		516	is not so important (or wise) to do it instantly. The callback will be
		517	invoked only when there is "nothing better to do", which is usually
		518	defined as "all outstanding events have been handled and no new events
		519	have been detected". That means that idle watchers ideally get invoked
		520	when the event loop has just polled for new events but none have been
		521	detected. Instead of blocking to wait for more events, the idle watchers
		522	will be invoked.
		523
		524	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	525	EV, Event and Glib do it in a usable fashion) - for the rest, AnyEvent
470	will simply call the callback "from time to time".	526	will simply call the callback "from time to time".
471		527
472	Example: read lines from STDIN, but only process them when the	528	Example: read lines from STDIN, but only process them when the
473	program is otherwise idle:	529	program is otherwise idle:
…		…
489	});	545	});
490	});	546	});
491		547
492	=head2 CONDITION VARIABLES	548	=head2 CONDITION VARIABLES
493		549
		550	$cv = AnyEvent->condvar;
		551
		552	$cv->send (<list>);
		553	my @res = $cv->recv;
		554
494	If you are familiar with some event loops you will know that all of them	555	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	556	require you to run some blocking "loop", "run" or similar function that
496	will actively watch for new events and call your callbacks.	557	will actively watch for new events and call your callbacks.
497		558
498	AnyEvent is slightly different: it expects somebody else to run the event	559	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).	560	loop and will only block when necessary (usually when told by the user).
500		561
501	The instrument to do that is called a "condition variable", so called	562	The tool to do that is called a "condition variable", so called because
502	because they represent a condition that must become true.	563	they represent a condition that must become true.
503		564
504	Now is probably a good time to look at the examples further below.	565	Now is probably a good time to look at the examples further below.
505		566
506	Condition variables can be created by calling the C<< AnyEvent->condvar	567	Condition variables can be created by calling the C<< AnyEvent->condvar
507	>> method, usually without arguments. The only argument pair allowed is	568	>> method, usually without arguments. The only argument pair allowed is
…		…
512	After creation, the condition variable is "false" until it becomes "true"	573	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	574	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<<	575	were a callback, read about the caveats in the description for the C<<
515	->send >> method).	576	->send >> method).
516		577
517	Condition variables are similar to callbacks, except that you can	578	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	579	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	580
520	another way to call them is transactions - each condition variable can be	581	=over 4
521	used to represent a transaction, which finishes at some point and delivers	582
522	a result. And yet some people know them as "futures" - a promise to	583	=item * Condition variables are like callbacks - you can call them (and pass them instead
523	compute/deliver something that you can wait for.	584	of callbacks). Unlike callbacks however, you can also wait for them to be called.
		585
		586	=item * Condition variables are signals - one side can emit or send them,
		587	the other side can wait for them, or install a handler that is called when
		588	the signal fires.
		589
		590	=item * Condition variables are like "Merge Points" - points in your program
		591	where you merge multiple independent results/control flows into one.
		592
		593	=item * Condition variables represent a transaction - function that start
		594	some kind of transaction can return them, leaving the caller the choice
		595	between waiting in a blocking fashion, or setting a callback.
		596
		597	=item * Condition variables represent future values, or promises to deliver
		598	some result, long before the result is available.
		599
		600	=back
524		601
525	Condition variables are very useful to signal that something has finished,	602	Condition variables are very useful to signal that something has finished,
526	for example, if you write a module that does asynchronous http requests,	603	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	604	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	605	availability of results. The user can either act when the callback is
…		…
549	eventually calls C<< -> send >>, and the "consumer side", which waits	626	eventually calls C<< -> send >>, and the "consumer side", which waits
550	for the send to occur.	627	for the send to occur.
551		628
552	Example: wait for a timer.	629	Example: wait for a timer.
553		630
554	# wait till the result is ready	631	# condition: "wait till the timer is fired"
555	my $result_ready = AnyEvent->condvar;	632	my $timer_fired = AnyEvent->condvar;
556		633
557	# do something such as adding a timer	634	# create the timer - we could wait for, say
558	# or socket watcher the calls $result_ready->send	635	# a handle becomign ready, or even an
559	# when the "result" is ready.	636	# AnyEvent::HTTP request to finish, but
560	# in this case, we simply use a timer:	637	# in this case, we simply use a timer:
561	my $w = AnyEvent->timer (	638	my $w = AnyEvent->timer (
562	after => 1,	639	after => 1,
563	cb => sub { $result_ready->send },	640	cb => sub { $timer_fired->send },
564	);	641	);
565		642
566	# this "blocks" (while handling events) till the callback	643	# this "blocks" (while handling events) till the callback
567	# calls -<send	644	# calls ->send
568	$result_ready->recv;	645	$timer_fired->recv;
569		646
570	Example: wait for a timer, but take advantage of the fact that condition	647	Example: wait for a timer, but take advantage of the fact that condition
571	variables are also callable directly.	648	variables are also callable directly.
572		649
573	my $done = AnyEvent->condvar;	650	my $done = AnyEvent->condvar;
…		…
636	one. For example, a function that pings many hosts in parallel might want	713	one. For example, a function that pings many hosts in parallel might want
637	to use a condition variable for the whole process.	714	to use a condition variable for the whole process.
638		715
639	Every call to C<< ->begin >> will increment a counter, and every call to	716	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	717	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	718	>>, 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	719	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.	720	>>, but that is not required. If no group callback was set, C<send> will
		721	be called without any arguments.
644		722
645	You can think of C<< $cv->send >> giving you an OR condition (one call	723	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	724	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).	725	condition (all C<begin> calls must be C<end>'ed before the condvar sends).
648		726
…		…
675	begung can potentially be zero:	753	begung can potentially be zero:
676		754
677	my $cv = AnyEvent->condvar;	755	my $cv = AnyEvent->condvar;
678		756
679	my %result;	757	my %result;
680	$cv->begin (sub { $cv->send (\%result) });	758	$cv->begin (sub { shift->send (\%result) });
681		759
682	for my $host (@list_of_hosts) {	760	for my $host (@list_of_hosts) {
683	$cv->begin;	761	$cv->begin;
684	ping_host_then_call_callback $host, sub {	762	ping_host_then_call_callback $host, sub {
685	$result{$host} = ...;	763	$result{$host} = ...;
…		…
760	=item $cb = $cv->cb ($cb->($cv))	838	=item $cb = $cv->cb ($cb->($cv))
761		839
762	This is a mutator function that returns the callback set and optionally	840	This is a mutator function that returns the callback set and optionally
763	replaces it before doing so.	841	replaces it before doing so.
764		842
765	The callback will be called when the condition becomes "true", i.e. when	843	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	844	"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	845	the only argument being the condition variable itself. Calling C<recv>
768	is guaranteed not to block.	846	inside the callback or at any later time is guaranteed not to block.
769		847
770	=back	848	=back
771		849
772	=head1 SUPPORTED EVENT LOOPS/BACKENDS	850	=head1 SUPPORTED EVENT LOOPS/BACKENDS
773		851
…		…
776	=over 4	854	=over 4
777		855
778	=item Backends that are autoprobed when no other event loop can be found.	856	=item Backends that are autoprobed when no other event loop can be found.
779		857
780	EV is the preferred backend when no other event loop seems to be in	858	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	859	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	860	pure-perl implementation, which is available everywhere as it comes with
783	available everywhere as it comes with AnyEvent itself.	861	AnyEvent itself.
784		862
785	AnyEvent::Impl::EV based on EV (interface to libev, best choice).	863	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.	864	AnyEvent::Impl::Perl pure-perl implementation, fast and portable.
788		865
789	=item Backends that are transparently being picked up when they are used.	866	=item Backends that are transparently being picked up when they are used.
790		867
791	These will be used when they are currently loaded when the first watcher	868	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	869	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	870	them. This means that AnyEvent will automatically pick the right backend
794	when the main program loads an event module before anything starts to	871	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.	872	create watchers. Nothing special needs to be done by the main program.
796		873
		874	AnyEvent::Impl::Event based on Event, very stable, few glitches.
797	AnyEvent::Impl::Glib based on Glib, slow but very stable.	875	AnyEvent::Impl::Glib based on Glib, slow but very stable.
798	AnyEvent::Impl::Tk based on Tk, very broken.	876	AnyEvent::Impl::Tk based on Tk, very broken.
799	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.	877	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
800	AnyEvent::Impl::POE based on POE, very slow, some limitations.	878	AnyEvent::Impl::POE based on POE, very slow, some limitations.
		879	AnyEvent::Impl::Irssi used when running within irssi.
801		880
802	=item Backends with special needs.	881	=item Backends with special needs.
803		882
804	Qt requires the Qt::Application to be instantiated first, but will	883	Qt requires the Qt::Application to be instantiated first, but will
805	otherwise be picked up automatically. As long as the main program	884	otherwise be picked up automatically. As long as the main program
…		…
879	event module detection too early, for example, L<AnyEvent::AIO> creates	958	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	959	and installs the global L<IO::AIO> watcher in a C<post_detect> block to
881	avoid autodetecting the event module at load time.	960	avoid autodetecting the event module at load time.
882		961
883	If called in scalar or list context, then it creates and returns an object	962	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	963	that automatically removes the callback again when it is destroyed (or
		964	C<undef> when the hook was immediately executed). See L<AnyEvent::AIO> for
885	L<Coro::BDB> for a case where this is useful.	965	a case where this is useful.
		966
		967	Example: Create a watcher for the IO::AIO module and store it in
		968	C<$WATCHER>. Only do so after the event loop is initialised, though.
		969
		970	our WATCHER;
		971
		972	my $guard = AnyEvent::post_detect {
		973	$WATCHER = AnyEvent->io (fh => IO::AIO::poll_fileno, poll => 'r', cb => \&IO::AIO::poll_cb);
		974	};
		975
		976	# the ||= is important in case post_detect immediately runs the block,
		977	# as to not clobber the newly-created watcher. assigning both watcher and
		978	# post_detect guard to the same variable has the advantage of users being
		979	# able to just C<undef $WATCHER> if the watcher causes them grief.
		980
		981	$WATCHER ||= $guard;
886		982
887	=item @AnyEvent::post_detect	983	=item @AnyEvent::post_detect
888		984
889	If there are any code references in this array (you can C<push> to it	985	If there are any code references in this array (you can C<push> to it
890	before or after loading AnyEvent), then they will called directly after	986	before or after loading AnyEvent), then they will called directly after
…		…
893	You should check C<$AnyEvent::MODEL> before adding to this array, though:	989	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	990	if it is defined then the event loop has already been detected, and the
895	array will be ignored.	991	array will be ignored.
896		992
897	Best use C<AnyEvent::post_detect { BLOCK }> when your application allows	993	Best use C<AnyEvent::post_detect { BLOCK }> when your application allows
898	it,as it takes care of these details.	994	it, as it takes care of these details.
899		995
900	This variable is mainly useful for modules that can do something useful	996	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	997	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	998	not need to even load it by default. This array provides the means to hook
903	into AnyEvent passively, without loading it.	999	into AnyEvent passively, without loading it.
		1000
		1001	Example: To load Coro::AnyEvent whenever Coro and AnyEvent are used
		1002	together, you could put this into Coro (this is the actual code used by
		1003	Coro to accomplish this):
		1004
		1005	if (defined $AnyEvent::MODEL) {
		1006	# AnyEvent already initialised, so load Coro::AnyEvent
		1007	require Coro::AnyEvent;
		1008	} else {
		1009	# AnyEvent not yet initialised, so make sure to load Coro::AnyEvent
		1010	# as soon as it is
		1011	push @AnyEvent::post_detect, sub { require Coro::AnyEvent };
		1012	}
904		1013
905	=back	1014	=back
906		1015
907	=head1 WHAT TO DO IN A MODULE	1016	=head1 WHAT TO DO IN A MODULE
908		1017
…		…
965	=head1 OTHER MODULES	1074	=head1 OTHER MODULES
966		1075
967	The following is a non-exhaustive list of additional modules that use	1076	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	1077	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	1078	modules and other event loops in the same program. Some of the modules
970	come with AnyEvent, most are available via CPAN.	1079	come as part of AnyEvent, the others are available via CPAN.
971		1080
972	=over 4	1081	=over 4
973		1082
974	=item L<AnyEvent::Util>	1083	=item L<AnyEvent::Util>
975		1084
…		…
990		1099
991	=item L<AnyEvent::DNS>	1100	=item L<AnyEvent::DNS>
992		1101
993	Provides rich asynchronous DNS resolver capabilities.	1102	Provides rich asynchronous DNS resolver capabilities.
994		1103
		1104	=item L<AnyEvent::HTTP>, L<AnyEvent::IRC>, L<AnyEvent::XMPP>, L<AnyEvent::GPSD>, L<AnyEvent::IGS>, L<AnyEvent::FCP>
		1105
		1106	Implement event-based interfaces to the protocols of the same name (for
		1107	the curious, IGS is the International Go Server and FCP is the Freenet
		1108	Client Protocol).
		1109
		1110	=item L<AnyEvent::Handle::UDP>
		1111
		1112	Here be danger!
		1113
		1114	As Pauli would put it, "Not only is it not right, it's not even wrong!" -
		1115	there are so many things wrong with AnyEvent::Handle::UDP, most notably
		1116	it's use of a stream-based API with a protocol that isn't streamable, that
		1117	the only way to improve it is to delete it.
		1118
		1119	It features data corruption (but typically only under load) and general
		1120	confusion. On top, the author is not only clueless about UDP but also
		1121	fact-resistant - some gems of his understanding: "connect doesn't work
		1122	with UDP", "UDP packets are not IP packets", "UDP only has datagrams, not
		1123	packets", "I don't need to implement proper error checking as UDP doesn't
		1124	support error checking" and so on - he doesn't even understand what's
		1125	wrong with his module when it is explained to him.
		1126
995	=item L<AnyEvent::HTTP>	1127	=item L<AnyEvent::DBI>
996		1128
997	A simple-to-use HTTP library that is capable of making a lot of concurrent	1129	Executes L<DBI> requests asynchronously in a proxy process for you,
998	HTTP requests.	1130	notifying you in an event-bnased way when the operation is finished.
		1131
		1132	=item L<AnyEvent::AIO>
		1133
		1134	Truly asynchronous (as opposed to non-blocking) I/O, should be in the
		1135	toolbox of every event programmer. AnyEvent::AIO transparently fuses
		1136	L<IO::AIO> and AnyEvent together, giving AnyEvent access to event-based
		1137	file I/O, and much more.
999		1138
1000	=item L<AnyEvent::HTTPD>	1139	=item L<AnyEvent::HTTPD>
1001		1140
1002	Provides a simple web application server framework.	1141	A simple embedded webserver.
1003		1142
1004	=item L<AnyEvent::FastPing>	1143	=item L<AnyEvent::FastPing>
1005		1144
1006	The fastest ping in the west.	1145	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		1146
1050	=item L<Coro>	1147	=item L<Coro>
1051		1148
1052	Has special support for AnyEvent via L<Coro::AnyEvent>.	1149	Has special support for AnyEvent via L<Coro::AnyEvent>.
1053		1150
…		…
1057		1154
1058	package AnyEvent;	1155	package AnyEvent;
1059		1156
1060	# basically a tuned-down version of common::sense	1157	# basically a tuned-down version of common::sense
1061	sub common_sense {	1158	sub common_sense {
1062	# no warnings	1159	# from common:.sense 1.0
1063	${^WARNING_BITS} ^= ${^WARNING_BITS};	1160	${^WARNING_BITS} = "\xfc\x3f\x33\x00\x0f\xf3\xcf\xc0\xf3\xfc\x33\x00";
1064	# use strict vars subs	1161	# use strict vars subs - NO UTF-8, as Util.pm doesn't like this atm. (uts46data.pl)
1065	$^H |= 0x00000600;	1162	$^H |= 0x00000600;
1066	}	1163	}
1067		1164
1068	BEGIN { AnyEvent::common_sense }	1165	BEGIN { AnyEvent::common_sense }
1069		1166
1070	use Carp ();	1167	use Carp ();
1071		1168
1072	our $VERSION = 4.85;	1169	our $VERSION = '5.271';
1073	our $MODEL;	1170	our $MODEL;
1074		1171
1075	our $AUTOLOAD;	1172	our $AUTOLOAD;
1076	our @ISA;	1173	our @ISA;
1077		1174
1078	our @REGISTRY;	1175	our @REGISTRY;
1079		1176
1080	our $WIN32;
1081
1082	our $VERBOSE;	1177	our $VERBOSE;
1083		1178
1084	BEGIN {	1179	BEGIN {
1085	eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }";	1180	require "AnyEvent/constants.pl";
		1181
1086	eval "sub TAINT(){ " . (${^TAINT}*1) . " }";	1182	eval "sub TAINT (){" . (${^TAINT}*1) . "}";
1087		1183
1088	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}	1184	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}
1089	if ${^TAINT};	1185	if ${^TAINT};
1090		1186
1091	$VERBOSE = $ENV{PERL_ANYEVENT_VERBOSE}*1;	1187	$VERBOSE = $ENV{PERL_ANYEVENT_VERBOSE}*1;
…		…
1102	for reverse split /\s*,\s*/,	1198	for reverse split /\s*,\s*/,
1103	$ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";	1199	$ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";
1104	}	1200	}
1105		1201
1106	my @models = (	1202	my @models = (
1107	[EV:: => AnyEvent::Impl::EV::],	1203	[EV:: => AnyEvent::Impl::EV:: , 1],
1108	[Event:: => AnyEvent::Impl::Event::],
1109	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::],	1204	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl:: , 1],
1110	# everything below here will not be autoprobed	1205	# everything below here will not (normally) be autoprobed
1111	# as the pureperl backend should work everywhere	1206	# as the pureperl backend should work everywhere
1112	# and is usually faster	1207	# and is usually faster
		1208	[Event:: => AnyEvent::Impl::Event::, 1],
1113	[Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers	1209	[Glib:: => AnyEvent::Impl::Glib:: , 1], # becomes extremely slow with many watchers
1114	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy	1210	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
		1211	[Irssi:: => AnyEvent::Impl::Irssi::], # Irssi has a bogus "Event" package
1115	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles	1212	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
1116	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program	1213	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program
1117	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza	1214	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
1118	[Wx:: => AnyEvent::Impl::POE::],	1215	[Wx:: => AnyEvent::Impl::POE::],
1119	[Prima:: => AnyEvent::Impl::POE::],	1216	[Prima:: => AnyEvent::Impl::POE::],
1120	# IO::Async is just too broken - we would need workarounds for its	1217	# IO::Async is just too broken - we would need workarounds for its
1121	# byzantine signal and broken child handling, among others.	1218	# byzantine signal and broken child handling, among others.
1122	# IO::Async is rather hard to detect, as it doesn't have any	1219	# IO::Async is rather hard to detect, as it doesn't have any
1123	# obvious default class.	1220	# obvious default class.
1124	# [IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program	1221	[IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program
1125	# [IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program	1222	[IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program
1126	# [IO::Async::Notifier:: => AnyEvent::Impl::IOAsync::], # requires special main program	1223	[IO::Async::Notifier:: => AnyEvent::Impl::IOAsync::], # requires special main program
		1224	[AnyEvent::Impl::IOAsync:: => AnyEvent::Impl::IOAsync::], # requires special main program
1127	);	1225	);
1128		1226
1129	our %method = map +($_ => 1),	1227	our %method = map +($_ => 1),
1130	qw(io timer time now now_update signal child idle condvar one_event DESTROY);	1228	qw(io timer time now now_update signal child idle condvar one_event DESTROY);
1131		1229
1132	our @post_detect;	1230	our @post_detect;
1133		1231
1134	sub post_detect(&) {	1232	sub post_detect(&) {
1135	my ($cb) = @_;	1233	my ($cb) = @_;
1136		1234
1137	if ($MODEL) {
1138	$cb->();
1139
1140	1
1141	} else {
1142	push @post_detect, $cb;	1235	push @post_detect, $cb;
1143		1236
1144	defined wantarray	1237	defined wantarray
1145	? bless \$cb, "AnyEvent::Util::postdetect"	1238	? bless \$cb, "AnyEvent::Util::postdetect"
1146	: ()	1239	: ()
1147	}
1148	}	1240	}
1149		1241
1150	sub AnyEvent::Util::postdetect::DESTROY {	1242	sub AnyEvent::Util::postdetect::DESTROY {
1151	@post_detect = grep $_ != ${$_[0]}, @post_detect;	1243	@post_detect = grep $_ != ${$_[0]}, @post_detect;
1152	}	1244	}
1153		1245
1154	sub detect() {	1246	sub detect() {
		1247	# free some memory
		1248	*detect = sub () { $MODEL };
		1249
		1250	local $!; # for good measure
		1251	local $SIG{__DIE__};
		1252
		1253	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {
		1254	my $model = "AnyEvent::Impl::$1";
		1255	if (eval "require $model") {
		1256	$MODEL = $model;
		1257	warn "AnyEvent: loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.\n" if $VERBOSE >= 2;
		1258	} else {
		1259	warn "AnyEvent: unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@" if $VERBOSE;
		1260	}
		1261	}
		1262
		1263	# check for already loaded models
1155	unless ($MODEL) {	1264	unless ($MODEL) {
1156	local $SIG{__DIE__};	1265	for (@REGISTRY, @models) {
1157		1266	my ($package, $model) = @$_;
1158	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {	1267	if (${"$package\::VERSION"} > 0) {
1159	my $model = "AnyEvent::Impl::$1";
1160	if (eval "require $model") {	1268	if (eval "require $model") {
1161	$MODEL = $model;	1269	$MODEL = $model;
1162	warn "AnyEvent: loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.\n" if $VERBOSE >= 2;	1270	warn "AnyEvent: autodetected model '$model', using it.\n" if $VERBOSE >= 2;
1163	} else {	1271	last;
1164	warn "AnyEvent: unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@" if $VERBOSE;	1272	}
1165	}	1273	}
1166	}	1274	}
1167		1275
1168	# check for already loaded models
1169	unless ($MODEL) {	1276	unless ($MODEL) {
		1277	# try to autoload a model
1170	for (@REGISTRY, @models) {	1278	for (@REGISTRY, @models) {
1171	my ($package, $model) = @$_;	1279	my ($package, $model, $autoload) = @$_;
		1280	if (
		1281	$autoload
		1282	and eval "require $package"
1172	if (${"$package\::VERSION"} > 0) {	1283	and ${"$package\::VERSION"} > 0
1173	if (eval "require $model") {	1284	and eval "require $model"
		1285	) {
1174	$MODEL = $model;	1286	$MODEL = $model;
1175	warn "AnyEvent: autodetected model '$model', using it.\n" if $VERBOSE >= 2;	1287	warn "AnyEvent: autoloaded model '$model', using it.\n" if $VERBOSE >= 2;
1176	last;	1288	last;
1177	}
1178	}	1289	}
1179	}	1290	}
1180		1291
1181	unless ($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	1292	$MODEL
1196	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.\n";	1293	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.\n";
1197	}
1198	}	1294	}
1199
1200	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
1201
1202	unshift @ISA, $MODEL;
1203
1204	require AnyEvent::Strict if $ENV{PERL_ANYEVENT_STRICT};
1205
1206	(shift @post_detect)->() while @post_detect;
1207	}	1295	}
		1296
		1297	@models = (); # free probe data
		1298
		1299	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
		1300	unshift @ISA, $MODEL;
		1301
		1302	# now nuke some methods that are overriden by the backend.
		1303	# SUPER is not allowed.
		1304	for (qw(time signal child idle)) {
		1305	undef &{"AnyEvent::Base::$_"}
		1306	if defined &{"$MODEL\::$_"};
		1307	}
		1308
		1309	require AnyEvent::Strict if $ENV{PERL_ANYEVENT_STRICT};
		1310
		1311	(shift @post_detect)->() while @post_detect;
		1312
		1313	*post_detect = sub(&) {
		1314	shift->();
		1315
		1316	undef
		1317	};
1208		1318
1209	$MODEL	1319	$MODEL
1210	}	1320	}
1211		1321
1212	sub AUTOLOAD {	1322	sub AUTOLOAD {
1213	(my $func = $AUTOLOAD) =~ s/.*://;	1323	(my $func = $AUTOLOAD) =~ s/.*://;
1214		1324
1215	$method{$func}	1325	$method{$func}
1216	or Carp::croak "$func: not a valid method for AnyEvent objects";	1326	or Carp::croak "$func: not a valid AnyEvent class method";
1217		1327
1218	detect unless $MODEL;	1328	detect;
1219		1329
1220	my $class = shift;	1330	my $class = shift;
1221	$class->$func (@_);	1331	$class->$func (@_);
1222	}	1332	}
1223		1333
…		…
1236	# we assume CLOEXEC is already set by perl in all important cases	1346	# we assume CLOEXEC is already set by perl in all important cases
1237		1347
1238	($fh2, $rw)	1348	($fh2, $rw)
1239	}	1349	}
1240		1350
		1351	=head1 SIMPLIFIED AE API
		1352
		1353	Starting with version 5.0, AnyEvent officially supports a second, much
		1354	simpler, API that is designed to reduce the calling, typing and memory
		1355	overhead by using function call syntax and a fixed number of parameters.
		1356
		1357	See the L<AE> manpage for details.
		1358
		1359	=cut
		1360
		1361	package AE;
		1362
		1363	our $VERSION = $AnyEvent::VERSION;
		1364
		1365	# fall back to the main API by default - backends and AnyEvent::Base
		1366	# implementations can overwrite these.
		1367
		1368	sub io($$$) {
		1369	AnyEvent->io (fh => $_[0], poll => $_[1] ? "w" : "r", cb => $_[2])
		1370	}
		1371
		1372	sub timer($$$) {
		1373	AnyEvent->timer (after => $_[0], interval => $_[1], cb => $_[2])
		1374	}
		1375
		1376	sub signal($$) {
		1377	AnyEvent->signal (signal => $_[0], cb => $_[1])
		1378	}
		1379
		1380	sub child($$) {
		1381	AnyEvent->child (pid => $_[0], cb => $_[1])
		1382	}
		1383
		1384	sub idle($) {
		1385	AnyEvent->idle (cb => $_[0])
		1386	}
		1387
		1388	sub cv(;&) {
		1389	AnyEvent->condvar (@_ ? (cb => $_[0]) : ())
		1390	}
		1391
		1392	sub now() {
		1393	AnyEvent->now
		1394	}
		1395
		1396	sub now_update() {
		1397	AnyEvent->now_update
		1398	}
		1399
		1400	sub time() {
		1401	AnyEvent->time
		1402	}
		1403
1241	package AnyEvent::Base;	1404	package AnyEvent::Base;
1242		1405
1243	# default implementations for many methods	1406	# default implementations for many methods
1244		1407
1245	sub _time {	1408	sub time {
		1409	eval q{ # poor man's autoloading {}
1246	# probe for availability of Time::HiRes	1410	# probe for availability of Time::HiRes
1247	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {	1411	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {
1248	warn "AnyEvent: using Time::HiRes for sub-second timing accuracy.\n" if $VERBOSE >= 8;	1412	warn "AnyEvent: using Time::HiRes for sub-second timing accuracy.\n" if $VERBOSE >= 8;
1249	*_time = \&Time::HiRes::time;	1413	*AE::time = \&Time::HiRes::time;
1250	# if (eval "use POSIX (); (POSIX::times())...	1414	# if (eval "use POSIX (); (POSIX::times())...
1251	} else {	1415	} else {
1252	warn "AnyEvent: using built-in time(), WARNING, no sub-second resolution!\n" if $VERBOSE;	1416	warn "AnyEvent: using built-in time(), WARNING, no sub-second resolution!\n" if $VERBOSE;
1253	*_time = sub { time }; # epic fail	1417	*AE::time = sub (){ time }; # epic fail
		1418	}
		1419
		1420	*time = sub { AE::time }; # different prototypes
1254	}	1421	};
		1422	die if $@;
1255		1423
1256	&_time	1424	&time
1257	}	1425	}
1258		1426
1259	sub time { _time }	1427	*now = \&time;
1260	sub now { _time }	1428
1261	sub now_update { }	1429	sub now_update { }
1262		1430
1263	# default implementation for ->condvar	1431	# default implementation for ->condvar
1264		1432
1265	sub condvar {	1433	sub condvar {
		1434	eval q{ # poor man's autoloading {}
		1435	*condvar = sub {
1266	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"	1436	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"
		1437	};
		1438
		1439	*AE::cv = sub (;&) {
		1440	bless { @_ ? (_ae_cb => shift) : () }, "AnyEvent::CondVar"
		1441	};
		1442	};
		1443	die if $@;
		1444
		1445	&condvar
1267	}	1446	}
1268		1447
1269	# default implementation for ->signal	1448	# default implementation for ->signal
1270		1449
1271	our $HAVE_ASYNC_INTERRUPT;	1450	our $HAVE_ASYNC_INTERRUPT;
		1451
		1452	sub _have_async_interrupt() {
		1453	$HAVE_ASYNC_INTERRUPT = 1*(!$ENV{PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT}
		1454	&& eval "use Async::Interrupt 1.02 (); 1")
		1455	unless defined $HAVE_ASYNC_INTERRUPT;
		1456
		1457	$HAVE_ASYNC_INTERRUPT
		1458	}
		1459
1272	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);	1460	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);
1273	our (%SIG_ASY, %SIG_ASY_W);	1461	our (%SIG_ASY, %SIG_ASY_W);
1274	our ($SIG_COUNT, $SIG_TW);	1462	our ($SIG_COUNT, $SIG_TW);
1275		1463
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	1464	# install a dummy wakeup watcher to reduce signal catching latency
		1465	# used by Impls
1290	sub _sig_add() {	1466	sub _sig_add() {
1291	unless ($SIG_COUNT++) {	1467	unless ($SIG_COUNT++) {
1292	# try to align timer on a full-second boundary, if possible	1468	# try to align timer on a full-second boundary, if possible
1293	my $NOW = AnyEvent->now;	1469	my $NOW = AE::now;
1294		1470
1295	$SIG_TW = AnyEvent->timer (	1471	$SIG_TW = AE::timer
1296	after => $MAX_SIGNAL_LATENCY - ($NOW - int $NOW),	1472	$MAX_SIGNAL_LATENCY - ($NOW - int $NOW),
1297	interval => $MAX_SIGNAL_LATENCY,	1473	$MAX_SIGNAL_LATENCY,
1298	cb => sub { }, # just for the PERL_ASYNC_CHECK	1474	sub { } # just for the PERL_ASYNC_CHECK
1299	);	1475	;
1300	}	1476	}
1301	}	1477	}
1302		1478
1303	sub _sig_del {	1479	sub _sig_del {
1304	undef $SIG_TW	1480	undef $SIG_TW
1305	unless --$SIG_COUNT;	1481	unless --$SIG_COUNT;
1306	}	1482	}
1307		1483
		1484	our $_sig_name_init; $_sig_name_init = sub {
		1485	eval q{ # poor man's autoloading {}
		1486	undef $_sig_name_init;
		1487
		1488	if (_have_async_interrupt) {
		1489	*sig2num = \&Async::Interrupt::sig2num;
		1490	*sig2name = \&Async::Interrupt::sig2name;
		1491	} else {
		1492	require Config;
		1493
		1494	my %signame2num;
		1495	@signame2num{ split ' ', $Config::Config{sig_name} }
		1496	= split ' ', $Config::Config{sig_num};
		1497
		1498	my @signum2name;
		1499	@signum2name[values %signame2num] = keys %signame2num;
		1500
		1501	*sig2num = sub($) {
		1502	$_[0] > 0 ? shift : $signame2num{+shift}
		1503	};
		1504	*sig2name = sub ($) {
		1505	$_[0] > 0 ? $signum2name[+shift] : shift
		1506	};
		1507	}
		1508	};
		1509	die if $@;
		1510	};
		1511
		1512	sub sig2num ($) { &$_sig_name_init; &sig2num }
		1513	sub sig2name($) { &$_sig_name_init; &sig2name }
		1514
1308	sub _signal {	1515	sub signal {
1309	my (undef, %arg) = @_;	1516	eval q{ # poor man's autoloading {}
		1517	# probe for availability of Async::Interrupt
		1518	if (_have_async_interrupt) {
		1519	warn "AnyEvent: using Async::Interrupt for race-free signal handling.\n" if $VERBOSE >= 8;
1310		1520
1311	my $signal = uc $arg{signal}	1521	$SIGPIPE_R = new Async::Interrupt::EventPipe;
1312	or Carp::croak "required option 'signal' is missing";	1522	$SIG_IO = AE::io $SIGPIPE_R->fileno, 0, \&_signal_exec;
1313		1523
1314	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};	1524	} else {
		1525	warn "AnyEvent: using emulated perl signal handling with latency timer.\n" if $VERBOSE >= 8;
1315		1526
1316	if ($HAVE_ASYNC_INTERRUPT) {	1527	if (AnyEvent::WIN32) {
1317	# async::interrupt	1528	require AnyEvent::Util;
1318		1529
1319	$SIG_ASY{$signal} ||= do {	1530	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
1320	my $asy = new Async::Interrupt	1531	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R, 1) if $SIGPIPE_R;
1321	cb => sub { undef $SIG_EV{$signal} },	1532	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W, 1) if $SIGPIPE_W; # just in case
1322	signal => $signal,	1533	} else {
1323	pipe => [$SIGPIPE_R->filenos],	1534	pipe $SIGPIPE_R, $SIGPIPE_W;
		1535	fcntl $SIGPIPE_R, AnyEvent::F_SETFL, AnyEvent::O_NONBLOCK if $SIGPIPE_R;
		1536	fcntl $SIGPIPE_W, AnyEvent::F_SETFL, AnyEvent::O_NONBLOCK if $SIGPIPE_W; # just in case
		1537
		1538	# not strictly required, as $^F is normally 2, but let's make sure...
		1539	fcntl $SIGPIPE_R, AnyEvent::F_SETFD, AnyEvent::FD_CLOEXEC;
		1540	fcntl $SIGPIPE_W, AnyEvent::F_SETFD, AnyEvent::FD_CLOEXEC;
1324	;	1541	}
1325	$asy->pipe_autodrain (0);
1326		1542
1327	$asy	1543	$SIGPIPE_R
		1544	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";
		1545
		1546	$SIG_IO = AE::io $SIGPIPE_R, 0, \&_signal_exec;
		1547	}
		1548
		1549	*signal = $HAVE_ASYNC_INTERRUPT
		1550	? sub {
		1551	my (undef, %arg) = @_;
		1552
		1553	# async::interrupt
		1554	my $signal = sig2num $arg{signal};
		1555	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
		1556
		1557	$SIG_ASY{$signal} ||= new Async::Interrupt
		1558	cb => sub { undef $SIG_EV{$signal} },
		1559	signal => $signal,
		1560	pipe => [$SIGPIPE_R->filenos],
		1561	pipe_autodrain => 0,
		1562	;
		1563
		1564	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
		1565	}
		1566	: sub {
		1567	my (undef, %arg) = @_;
		1568
		1569	# pure perl
		1570	my $signal = sig2name $arg{signal};
		1571	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
		1572
		1573	$SIG{$signal} ||= sub {
		1574	local $!;
		1575	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;
		1576	undef $SIG_EV{$signal};
		1577	};
		1578
		1579	# can't do signal processing without introducing races in pure perl,
		1580	# so limit the signal latency.
		1581	_sig_add;
		1582
		1583	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
		1584	}
		1585	;
		1586
		1587	*AnyEvent::Base::signal::DESTROY = sub {
		1588	my ($signal, $cb) = @{$_[0]};
		1589
		1590	_sig_del;
		1591
		1592	delete $SIG_CB{$signal}{$cb};
		1593
		1594	$HAVE_ASYNC_INTERRUPT
		1595	? delete $SIG_ASY{$signal}
		1596	: # delete doesn't work with older perls - they then
		1597	# print weird messages, or just unconditionally exit
		1598	# instead of getting the default action.
		1599	undef $SIG{$signal}
		1600	unless keys %{ $SIG_CB{$signal} };
1328	};	1601	};
1329		1602
1330	} else {	1603	*_signal_exec = sub {
1331	# pure perl	1604	$HAVE_ASYNC_INTERRUPT
		1605	? $SIGPIPE_R->drain
		1606	: sysread $SIGPIPE_R, (my $dummy), 9;
1332		1607
1333	$SIG{$signal} ||= sub {	1608	while (%SIG_EV) {
1334	local $!;	1609	for (keys %SIG_EV) {
1335	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;	1610	delete $SIG_EV{$_};
1336	undef $SIG_EV{$signal};	1611	$_->() for values %{ $SIG_CB{$_} || {} };
		1612	}
		1613	}
1337	};	1614	};
1338
1339	# can't do signal processing without introducing races in pure perl,
1340	# so limit the signal latency.
1341	_sig_add;
1342	}	1615	};
		1616	die if $@;
1343		1617
1344	bless [$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 => $SIGPIPE_R, poll => "r", cb => \&_signal_exec);
1381	}
1382
1383	*signal = \&_signal;
1384	&signal	1618	&signal
1385	}
1386
1387	sub AnyEvent::Base::signal::DESTROY {
1388	my ($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	}	1619	}
1402		1620
1403	# default implementation for ->child	1621	# default implementation for ->child
1404		1622
1405	our %PID_CB;	1623	our %PID_CB;
1406	our $CHLD_W;	1624	our $CHLD_W;
1407	our $CHLD_DELAY_W;	1625	our $CHLD_DELAY_W;
1408	our $WNOHANG;	1626	our $WNOHANG;
1409		1627
1410	sub _sigchld {	1628	# used by many Impl's
1411	while (0 < (my $pid = waitpid -1, $WNOHANG)) {	1629	sub _emit_childstatus($$) {
1412	$_->($pid, $?)	1630	my (undef, $rpid, $rstatus) = @_;
		1631
		1632	$_->($rpid, $rstatus)
1413	for values %{ $PID_CB{$pid} || {} },	1633	for values %{ $PID_CB{$rpid} || {} },
1414	values %{ $PID_CB{0} || {} };	1634	values %{ $PID_CB{0} || {} };
1415	}
1416	}	1635	}
1417		1636
1418	sub child {	1637	sub child {
		1638	eval q{ # poor man's autoloading {}
		1639	*_sigchld = sub {
		1640	my $pid;
		1641
		1642	AnyEvent->_emit_childstatus ($pid, $?)
		1643	while ($pid = waitpid -1, $WNOHANG) > 0;
		1644	};
		1645
		1646	*child = sub {
1419	my (undef, %arg) = @_;	1647	my (undef, %arg) = @_;
1420		1648
1421	defined (my $pid = $arg{pid} + 0)	1649	defined (my $pid = $arg{pid} + 0)
1422	or Carp::croak "required option 'pid' is missing";	1650	or Carp::croak "required option 'pid' is missing";
1423		1651
1424	$PID_CB{$pid}{$arg{cb}} = $arg{cb};	1652	$PID_CB{$pid}{$arg{cb}} = $arg{cb};
1425		1653
1426	# WNOHANG is almost cetrainly 1 everywhere	1654	# WNOHANG is almost cetrainly 1 everywhere
1427	$WNOHANG ||= $^O =~ /^(?:openbsd|netbsd|linux|freebsd|cygwin|MSWin32)$/	1655	$WNOHANG ||= $^O =~ /^(?:openbsd|netbsd|linux|freebsd|cygwin|MSWin32)$/
1428	? 1	1656	? 1
1429	: eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1;	1657	: eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1;
1430		1658
1431	unless ($CHLD_W) {	1659	unless ($CHLD_W) {
1432	$CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld);	1660	$CHLD_W = AE::signal CHLD => \&_sigchld;
1433	# child could be a zombie already, so make at least one round	1661	# child could be a zombie already, so make at least one round
1434	&_sigchld;	1662	&_sigchld;
1435	}	1663	}
1436		1664
1437	bless [$pid, $arg{cb}], "AnyEvent::Base::child"	1665	bless [$pid, $arg{cb}], "AnyEvent::Base::child"
1438	}	1666	};
1439		1667
1440	sub AnyEvent::Base::child::DESTROY {	1668	*AnyEvent::Base::child::DESTROY = sub {
1441	my ($pid, $cb) = @{$_[0]};	1669	my ($pid, $cb) = @{$_[0]};
1442		1670
1443	delete $PID_CB{$pid}{$cb};	1671	delete $PID_CB{$pid}{$cb};
1444	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };	1672	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };
1445		1673
1446	undef $CHLD_W unless keys %PID_CB;	1674	undef $CHLD_W unless keys %PID_CB;
		1675	};
		1676	};
		1677	die if $@;
		1678
		1679	&child
1447	}	1680	}
1448		1681
1449	# idle emulation is done by simply using a timer, regardless	1682	# idle emulation is done by simply using a timer, regardless
1450	# of whether the process is idle or not, and not letting	1683	# of whether the process is idle or not, and not letting
1451	# the callback use more than 50% of the time.	1684	# the callback use more than 50% of the time.
1452	sub idle {	1685	sub idle {
		1686	eval q{ # poor man's autoloading {}
		1687	*idle = sub {
1453	my (undef, %arg) = @_;	1688	my (undef, %arg) = @_;
1454		1689
1455	my ($cb, $w, $rcb) = $arg{cb};	1690	my ($cb, $w, $rcb) = $arg{cb};
1456		1691
1457	$rcb = sub {	1692	$rcb = sub {
1458	if ($cb) {	1693	if ($cb) {
1459	$w = _time;	1694	$w = _time;
1460	&$cb;	1695	&$cb;
1461	$w = _time - $w;	1696	$w = _time - $w;
1462		1697
1463	# never use more then 50% of the time for the idle watcher,	1698	# never use more then 50% of the time for the idle watcher,
1464	# within some limits	1699	# within some limits
1465	$w = 0.0001 if $w < 0.0001;	1700	$w = 0.0001 if $w < 0.0001;
1466	$w = 5 if $w > 5;	1701	$w = 5 if $w > 5;
1467		1702
1468	$w = AnyEvent->timer (after => $w, cb => $rcb);	1703	$w = AE::timer $w, 0, $rcb;
1469	} else {	1704	} else {
1470	# clean up...	1705	# clean up...
1471	undef $w;	1706	undef $w;
1472	undef $rcb;	1707	undef $rcb;
		1708	}
		1709	};
		1710
		1711	$w = AE::timer 0.05, 0, $rcb;
		1712
		1713	bless \\$cb, "AnyEvent::Base::idle"
1473	}	1714	};
		1715
		1716	*AnyEvent::Base::idle::DESTROY = sub {
		1717	undef $${$_[0]};
		1718	};
1474	};	1719	};
		1720	die if $@;
1475		1721
1476	$w = AnyEvent->timer (after => 0.05, cb => $rcb);	1722	&idle
1477
1478	bless \\$cb, "AnyEvent::Base::idle"
1479	}
1480
1481	sub AnyEvent::Base::idle::DESTROY {
1482	undef $${$_[0]};
1483	}	1723	}
1484		1724
1485	package AnyEvent::CondVar;	1725	package AnyEvent::CondVar;
1486		1726
1487	our @ISA = AnyEvent::CondVar::Base::;	1727	our @ISA = AnyEvent::CondVar::Base::;
…		…
1535	Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak};	1775	Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak};
1536	wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0]	1776	wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0]
1537	}	1777	}
1538		1778
1539	sub cb {	1779	sub cb {
1540	$_[0]{_ae_cb} = $_[1] if @_ > 1;	1780	my $cv = shift;
		1781
		1782	@_
		1783	and $cv->{_ae_cb} = shift
		1784	and $cv->{_ae_sent}
		1785	and (delete $cv->{_ae_cb})->($cv);
		1786
1541	$_[0]{_ae_cb}	1787	$cv->{_ae_cb}
1542	}	1788	}
1543		1789
1544	sub begin {	1790	sub begin {
1545	++$_[0]{_ae_counter};	1791	++$_[0]{_ae_counter};
1546	$_[0]{_ae_end_cb} = $_[1] if @_ > 1;	1792	$_[0]{_ae_end_cb} = $_[1] if @_ > 1;
…		…
1755	warn "read: $input\n"; # output what has been read	2001	warn "read: $input\n"; # output what has been read
1756	$cv->send if $input =~ /^q/i; # quit program if /^q/i	2002	$cv->send if $input =~ /^q/i; # quit program if /^q/i
1757	},	2003	},
1758	);	2004	);
1759		2005
1760	my $time_watcher; # can only be used once
1761
1762	sub new_timer {
1763	$timer = AnyEvent->timer (after => 1, cb => sub {	2006	my $time_watcher = AnyEvent->timer (after => 1, interval => 1, cb => sub {
1764	warn "timeout\n"; # print 'timeout' about every second	2007	warn "timeout\n"; # print 'timeout' at most every second
1765	&new_timer; # and restart the time
1766	});	2008	});
1767	}
1768
1769	new_timer; # create first timer
1770		2009
1771	$cv->recv; # wait until user enters /^q/i	2010	$cv->recv; # wait until user enters /^q/i
1772		2011
1773	=head1 REAL-WORLD EXAMPLE	2012	=head1 REAL-WORLD EXAMPLE
1774		2013
…		…
1847		2086
1848	The actual code goes further and collects all errors (C<die>s, exceptions)	2087	The actual code goes further and collects all errors (C<die>s, exceptions)
1849	that occurred during request processing. The C<result> method detects	2088	that occurred during request processing. The C<result> method detects
1850	whether an exception as thrown (it is stored inside the $txn object)	2089	whether an exception as thrown (it is stored inside the $txn object)
1851	and just throws the exception, which means connection errors and other	2090	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	2091	problems get reported to the code that tries to use the result, not in a
1853	random callback.	2092	random callback.
1854		2093
1855	All of this enables the following usage styles:	2094	All of this enables the following usage styles:
1856		2095
1857	1. Blocking:	2096	1. Blocking:
…		…
1905	through AnyEvent. The benchmark creates a lot of timers (with a zero	2144	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,	2145	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.	2146	which it is), lets them fire exactly once and destroys them again.
1908		2147
1909	Source code for this benchmark is found as F<eg/bench> in the AnyEvent	2148	Source code for this benchmark is found as F<eg/bench> in the AnyEvent
1910	distribution.	2149	distribution. It uses the L<AE> interface, which makes a real difference
		2150	for the EV and Perl backends only.
1911		2151
1912	=head3 Explanation of the columns	2152	=head3 Explanation of the columns
1913		2153
1914	I<watcher> is the number of event watchers created/destroyed. Since	2154	I<watcher> is the number of event watchers created/destroyed. Since
1915	different event models feature vastly different performances, each event	2155	different event models feature vastly different performances, each event
…		…
1936	watcher.	2176	watcher.
1937		2177
1938	=head3 Results	2178	=head3 Results
1939		2179
1940	name watchers bytes create invoke destroy comment	2180	name watchers bytes create invoke destroy comment
1941	EV/EV 400000 224 0.47 0.35 0.27 EV native interface	2181	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	2182	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	2183	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	2184	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	2185	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	2186	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	2187	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	2188	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	2189	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	2190	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	2191	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	2192	POE/Any 2000 6648 94.79 774.40 575.51 via POE::Loop::Select
1953		2193
1954	=head3 Discussion	2194	=head3 Discussion
1955		2195
1956	The benchmark does I<not> measure scalability of the event loop very	2196	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)	2197	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	2209	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	2210	EV, 3100 CPU cycles with AnyEvent's pure perl loop and almost 3000000 CPU
1971	cycles with POE.	2211	cycles with POE.
1972		2212
1973	C<EV> is the sole leader regarding speed and memory use, which are both	2213	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	2214	maximal/minimal, respectively. When using the L<AE> API there is zero
		2215	overhead (when going through the AnyEvent API create is about 5-6 times
		2216	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	2217	any other event loop and is still faster than Event natively).
1976	natively.
1977		2218
1978	The pure perl implementation is hit in a few sweet spots (both the	2219	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	2220	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	2221	interpreter and the backend itself). Nevertheless this shows that it
1981	adds very little overhead in itself. Like any select-based backend its	2222	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	2296	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	2297	(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.	2298	connections, most of which are idle at any one point in time.
2058		2299
2059	Source code for this benchmark is found as F<eg/bench2> in the AnyEvent	2300	Source code for this benchmark is found as F<eg/bench2> in the AnyEvent
2060	distribution.	2301	distribution. It uses the L<AE> interface, which makes a real difference
		2302	for the EV and Perl backends only.
2061		2303
2062	=head3 Explanation of the columns	2304	=head3 Explanation of the columns
2063		2305
2064	I<sockets> is the number of sockets, and twice the number of "servers" (as	2306	I<sockets> is the number of sockets, and twice the number of "servers" (as
2065	each server has a read and write socket end).	2307	each server has a read and write socket end).
…		…
2073	a new one that moves the timeout into the future.	2315	a new one that moves the timeout into the future.
2074		2316
2075	=head3 Results	2317	=head3 Results
2076		2318
2077	name sockets create request	2319	name sockets create request
2078	EV 20000 69.01 11.16	2320	EV 20000 62.66 7.99
2079	Perl 20000 73.32 35.87	2321	Perl 20000 68.32 32.64
2080	IOAsync 20000 157.00 98.14 epoll	2322	IOAsync 20000 174.06 101.15 epoll
2081	IOAsync 20000 159.31 616.06 poll	2323	IOAsync 20000 174.67 610.84 poll
2082	Event 20000 212.62 257.32	2324	Event 20000 202.69 242.91
2083	Glib 20000 651.16 1896.30	2325	Glib 20000 557.01 1689.52
2084	POE 20000 349.67 12317.24 uses POE::Loop::Event	2326	POE 20000 341.54 12086.32 uses POE::Loop::Event
2085		2327
2086	=head3 Discussion	2328	=head3 Discussion
2087		2329
2088	This benchmark I<does> measure scalability and overall performance of the	2330	This benchmark I<does> measure scalability and overall performance of the
2089	particular event loop.	2331	particular event loop.
…		…
2215	As you can see, the AnyEvent + EV combination even beats the	2457	As you can see, the AnyEvent + EV combination even beats the
2216	hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl	2458	hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl
2217	backend easily beats IO::Lambda and POE.	2459	backend easily beats IO::Lambda and POE.
2218		2460
2219	And even the 100% non-blocking version written using the high-level (and	2461	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	2462	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	2463	higher level ("unoptimised") abstractions by a large margin, even though
2222	in a non-blocking way.	2464	it does all of DNS, tcp-connect and socket I/O in a non-blocking way.
2223		2465
2224	The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and	2466	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	2467	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.	2468	part of the IO::Lambda distribution and were used without any changes.
2227		2469
2228		2470
2229	=head1 SIGNALS	2471	=head1 SIGNALS
2230		2472
2231	AnyEvent currently installs handlers for these signals:	2473	AnyEvent currently installs handlers for these signals:
…		…
2273	it's built-in modules) are required to use it.	2515	it's built-in modules) are required to use it.
2274		2516
2275	That does not mean that AnyEvent won't take advantage of some additional	2517	That does not mean that AnyEvent won't take advantage of some additional
2276	modules if they are installed.	2518	modules if they are installed.
2277		2519
2278	This section epxlains which additional modules will be used, and how they	2520	This section explains which additional modules will be used, and how they
2279	affect AnyEvent's operetion.	2521	affect AnyEvent's operation.
2280		2522
2281	=over 4	2523	=over 4
2282		2524
2283	=item L<Async::Interrupt>	2525	=item L<Async::Interrupt>
2284		2526
…		…
2289	catch the signals) with some delay (default is 10 seconds, look for	2531	catch the signals) with some delay (default is 10 seconds, look for
2290	C<$AnyEvent::MAX_SIGNAL_LATENCY>).	2532	C<$AnyEvent::MAX_SIGNAL_LATENCY>).
2291		2533
2292	If this module is available, then it will be used to implement signal	2534	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	2535	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	2536	will not be interrupted regularly, which is more efficient (and good for
2295	battery life on laptops).	2537	battery life on laptops).
2296		2538
2297	This affects not just the pure-perl event loop, but also other event loops	2539	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).	2540	that have no signal handling on their own (e.g. Glib, Tk, Qt).
2299		2541
…		…
2311	automatic timer adjustments even when no monotonic clock is available,	2553	automatic timer adjustments even when no monotonic clock is available,
2312	can take avdantage of advanced kernel interfaces such as C<epoll> and	2554	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	2555	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>).	2556	L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>).
2315		2557
		2558	If you only use backends that rely on another event loop (e.g. C<Tk>),
		2559	then this module will do nothing for you.
		2560
2316	=item L<Guard>	2561	=item L<Guard>
2317		2562
2318	The guard module, when used, will be used to implement	2563	The guard module, when used, will be used to implement
2319	C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a	2564	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	2565	lot less memory), but otherwise doesn't affect guard operation much. It is
2321	purely used for performance.	2566	purely used for performance.
2322		2567
2323	=item L<JSON> and L<JSON::XS>	2568	=item L<JSON> and L<JSON::XS>
2324		2569
2325	This module is required when you want to read or write JSON data via	2570	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	2571	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.	2572	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		2573
2332	=item L<Net::SSLeay>	2574	=item L<Net::SSLeay>
2333		2575
2334	Implementing TLS/SSL in Perl is certainly interesting, but not very	2576	Implementing TLS/SSL in Perl is certainly interesting, but not very
2335	worthwhile: If this module is installed, then L<AnyEvent::Handle> (with	2577	worthwhile: If this module is installed, then L<AnyEvent::Handle> (with
…		…
2346		2588
2347		2589
2348	=head1 FORK	2590	=head1 FORK
2349		2591
2350	Most event libraries are not fork-safe. The ones who are usually are	2592	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>	2593	because they rely on inefficient but fork-safe C<select> or C<poll> calls
2352	calls. Only L<EV> is fully fork-aware.	2594	- higher performance APIs such as BSD's kqueue or the dreaded Linux epoll
		2595	are usually badly thought-out hacks that are incompatible with fork in
		2596	one way or another. Only L<EV> is fully fork-aware and ensures that you
		2597	continue event-processing in both parent and child (or both, if you know
		2598	what you are doing).
		2599
		2600	This means that, in general, you cannot fork and do event processing in
		2601	the child if the event library was initialised before the fork (which
		2602	usually happens when the first AnyEvent watcher is created, or the library
		2603	is loaded).
2353		2604
2354	If you have to fork, you must either do so I<before> creating your first	2605	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	2606	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.	2607	something completely out of the scope of AnyEvent.
		2608
		2609	The problem of doing event processing in the parent I<and> the child
		2610	is much more complicated: even for backends that I<are> fork-aware or
		2611	fork-safe, their behaviour is not usually what you want: fork clones all
		2612	watchers, that means all timers, I/O watchers etc. are active in both
		2613	parent and child, which is almost never what you want. USing C<exec>
		2614	to start worker children from some kind of manage rprocess is usually
		2615	preferred, because it is much easier and cleaner, at the expense of having
		2616	to have another binary.
2357		2617
2358		2618
2359	=head1 SECURITY CONSIDERATIONS	2619	=head1 SECURITY CONSIDERATIONS
2360		2620
2361	AnyEvent can be forced to load any event model via	2621	AnyEvent can be forced to load any event model via
…		…
2399	L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.	2659	L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.
2400		2660
2401	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,	2661	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,
2402	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,	2662	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,
2403	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,	2663	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,
2404	L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>.	2664	L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>, L<Anyevent::Impl::Irssi>.
2405		2665
2406	Non-blocking file handles, sockets, TCP clients and	2666	Non-blocking file handles, sockets, TCP clients and
2407	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.	2667	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.
2408		2668
2409	Asynchronous DNS: L<AnyEvent::DNS>.	2669	Asynchronous DNS: L<AnyEvent::DNS>.

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