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Revision 1.327 by root, Sun Jun 6 10:13:57 2010 UTC

1	=head1 NAME	1	=head1 NAME
2		2
3	AnyEvent - provide framework for multiple event loops	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 => ...
…		…
40	=head1 INTRODUCTION/TUTORIAL	43	=head1 INTRODUCTION/TUTORIAL
41		44
42	This manpage is mainly a reference manual. If you are interested	45	This manpage is mainly a reference manual. If you are interested
43	in a tutorial or some gentle introduction, have a look at the	46	in a tutorial or some gentle introduction, have a look at the
44	L<AnyEvent::Intro> manpage.	47	L<AnyEvent::Intro> manpage.
		48
		49	=head1 SUPPORT
		50
		51	There is a mailinglist for discussing all things AnyEvent, and an IRC
		52	channel, too.
		53
		54	See the AnyEvent project page at the B<Schmorpforge Ta-Sa Software
		55	Repository>, at L<http://anyevent.schmorp.de>, for more info.
45		56
46	=head1 WHY YOU SHOULD USE THIS MODULE (OR NOT)	57	=head1 WHY YOU SHOULD USE THIS MODULE (OR NOT)
47		58
48	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
49	nowadays. So what is different about AnyEvent?	60	nowadays. So what is different about AnyEvent?
…		…
173	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
174	declared.	185	declared.
175		186
176	=head2 I/O WATCHERS	187	=head2 I/O WATCHERS
177		188
		189	$w = AnyEvent->io (
		190	fh => <filehandle_or_fileno>,
		191	poll => <"r" or "w">,
		192	cb => <callback>,
		193	);
		194
178	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
179	with the following mandatory key-value pairs as arguments:	196	with the following mandatory key-value pairs as arguments:
180		197
181	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
182	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
…		…
211	undef $w;	228	undef $w;
212	});	229	});
213		230
214	=head2 TIME WATCHERS	231	=head2 TIME WATCHERS
215		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
216	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 >>
217	method with the following mandatory arguments:	242	method with the following mandatory arguments:
218		243
219	C<after> specifies after how many seconds (fractional values are	244	C<after> specifies after how many seconds (fractional values are
220	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
…		…
341	might affect timers and time-outs.	366	might affect timers and time-outs.
342		367
343	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
344	event loop's idea of "current time".	369	event loop's idea of "current time".
345		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
346	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.
347		379
348	=back	380	=back
349		381
350	=head2 SIGNAL WATCHERS	382	=head2 SIGNAL WATCHERS
		383
		384	$w = AnyEvent->signal (signal => <uppercase_signal_name>, cb => <callback>);
351		385
352	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
353	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
354	callback to be invoked whenever a signal occurs.	388	callback to be invoked whenever a signal occurs.
355		389
…		…
372		406
373	Example: exit on SIGINT	407	Example: exit on SIGINT
374		408
375	my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });	409	my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });
376		410
		411	=head3 Restart Behaviour
		412
		413	While restart behaviour is up to the event loop implementation, most will
		414	not restart syscalls (that includes L<Async::Interrupt> and AnyEvent's
		415	pure perl implementation).
		416
		417	=head3 Safe/Unsafe Signals
		418
		419	Perl signals can be either "safe" (synchronous to opcode handling) or
		420	"unsafe" (asynchronous) - the former might get delayed indefinitely, the
		421	latter might corrupt your memory.
		422
		423	AnyEvent signal handlers are, in addition, synchronous to the event loop,
		424	i.e. they will not interrupt your running perl program but will only be
		425	called as part of the normal event handling (just like timer, I/O etc.
		426	callbacks, too).
		427
377	=head3 Signal Races, Delays and Workarounds	428	=head3 Signal Races, Delays and Workarounds
378		429
379	Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support attaching	430	Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support attaching
380	callbacks to signals in a generic way, which is a pity, as you cannot do	431	callbacks to signals in a generic way, which is a pity, as you cannot
381	race-free signal handling in perl. AnyEvent will try to do it's best, but	432	do race-free signal handling in perl, requiring C libraries for
		433	this. AnyEvent will try to do it's best, which means in some cases,
382	in some cases, signals will be delayed. The maximum time a signal might	434	signals will be delayed. The maximum time a signal might be delayed is
383	be delayed is specified in C<$AnyEvent::MAX_SIGNAL_LATENCY> (default: 10	435	specified in C<$AnyEvent::MAX_SIGNAL_LATENCY> (default: 10 seconds). This
384	seconds). This variable can be changed only before the first signal	436	variable can be changed only before the first signal watcher is created,
385	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
386	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
387	saving. All these problems can be avoided by installing the optional	442	All these problems can be avoided by installing the optional
388	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
389	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>
390	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
391	those, you just have to suffer the delays.	446	one-second latency). For those, you just have to suffer the delays.
392		447
393	=head2 CHILD PROCESS WATCHERS	448	=head2 CHILD PROCESS WATCHERS
394		449
		450	$w = AnyEvent->child (pid => <process id>, cb => <callback>);
		451
395	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.
396		453
397	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,
398	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
399	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
400	any trace events (stopped/continued).	457	finished and an exit status is available, not on any trace events
		458	(stopped/continued).
401		459
402	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
403	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
404	callback arguments.	462	callback arguments.
405		463
…		…
446	# do something else, then wait for process exit	504	# do something else, then wait for process exit
447	$done->recv;	505	$done->recv;
448		506
449	=head2 IDLE WATCHERS	507	=head2 IDLE WATCHERS
450		508
451	Sometimes there is a need to do something, but it is not so important	509	$w = AnyEvent->idle (cb => <callback>);
452	to do it instantly, but only when there is nothing better to do. This
453	"nothing better to do" is usually defined to be "no other events need
454	attention by the event loop".
455		510
456	Idle watchers ideally get invoked when the event loop has nothing	511	Repeatedly invoke the callback after the process becomes idle, until
457	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.
458	events. Instead of blocking, the idle watcher is invoked.
459		513
460	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
461	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
462	will simply call the callback "from time to time".	525	will simply call the callback "from time to time".
463		526
464	Example: read lines from STDIN, but only process them when the	527	Example: read lines from STDIN, but only process them when the
465	program is otherwise idle:	528	program is otherwise idle:
…		…
481	});	544	});
482	});	545	});
483		546
484	=head2 CONDITION VARIABLES	547	=head2 CONDITION VARIABLES
485		548
		549	$cv = AnyEvent->condvar;
		550
		551	$cv->send (<list>);
		552	my @res = $cv->recv;
		553
486	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
487	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
488	will actively watch for new events and call your callbacks.	556	will actively watch for new events and call your callbacks.
489		557
490	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
491	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).
492		560
493	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
494	because they represent a condition that must become true.	562	they represent a condition that must become true.
495		563
496	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.
497		565
498	Condition variables can be created by calling the C<< AnyEvent->condvar	566	Condition variables can be created by calling the C<< AnyEvent->condvar
499	>> method, usually without arguments. The only argument pair allowed is	567	>> method, usually without arguments. The only argument pair allowed is
…		…
504	After creation, the condition variable is "false" until it becomes "true"	572	After creation, the condition variable is "false" until it becomes "true"
505	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
506	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<<
507	->send >> method).	575	->send >> method).
508		576
509	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
510	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:
511	in time where multiple outstanding events have been processed. And yet	579
512	another way to call them is transactions - each condition variable can be	580	=over 4
513	used to represent a transaction, which finishes at some point and delivers	581
514	a result.	582	=item * Condition variables are like callbacks - you can call them (and pass them instead
		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
515		600
516	Condition variables are very useful to signal that something has finished,	601	Condition variables are very useful to signal that something has finished,
517	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,
518	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
519	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
…		…
540	eventually calls C<< -> send >>, and the "consumer side", which waits	625	eventually calls C<< -> send >>, and the "consumer side", which waits
541	for the send to occur.	626	for the send to occur.
542		627
543	Example: wait for a timer.	628	Example: wait for a timer.
544		629
545	# wait till the result is ready	630	# condition: "wait till the timer is fired"
546	my $result_ready = AnyEvent->condvar;	631	my $timer_fired = AnyEvent->condvar;
547		632
548	# do something such as adding a timer	633	# create the timer - we could wait for, say
549	# or socket watcher the calls $result_ready->send	634	# a handle becomign ready, or even an
550	# when the "result" is ready.	635	# AnyEvent::HTTP request to finish, but
551	# in this case, we simply use a timer:	636	# in this case, we simply use a timer:
552	my $w = AnyEvent->timer (	637	my $w = AnyEvent->timer (
553	after => 1,	638	after => 1,
554	cb => sub { $result_ready->send },	639	cb => sub { $timer_fired->send },
555	);	640	);
556		641
557	# this "blocks" (while handling events) till the callback	642	# this "blocks" (while handling events) till the callback
558	# calls -<send	643	# calls ->send
559	$result_ready->recv;	644	$timer_fired->recv;
560		645
561	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
562	variables are also callable directly.	647	variables are also callable directly.
563		648
564	my $done = AnyEvent->condvar;	649	my $done = AnyEvent->condvar;
…		…
627	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
628	to use a condition variable for the whole process.	713	to use a condition variable for the whole process.
629		714
630	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
631	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
632	>>, 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
633	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
634	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.
635		721
636	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
637	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
638	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).
639		725
…		…
666	begung can potentially be zero:	752	begung can potentially be zero:
667		753
668	my $cv = AnyEvent->condvar;	754	my $cv = AnyEvent->condvar;
669		755
670	my %result;	756	my %result;
671	$cv->begin (sub { $cv->send (\%result) });	757	$cv->begin (sub { shift->send (\%result) });
672		758
673	for my $host (@list_of_hosts) {	759	for my $host (@list_of_hosts) {
674	$cv->begin;	760	$cv->begin;
675	ping_host_then_call_callback $host, sub {	761	ping_host_then_call_callback $host, sub {
676	$result{$host} = ...;	762	$result{$host} = ...;
…		…
751	=item $cb = $cv->cb ($cb->($cv))	837	=item $cb = $cv->cb ($cb->($cv))
752		838
753	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
754	replaces it before doing so.	840	replaces it before doing so.
755		841
756	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)
757	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
758	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>
759	is guaranteed not to block.	845	inside the callback or at any later time is guaranteed not to block.
760		846
761	=back	847	=back
762		848
763	=head1 SUPPORTED EVENT LOOPS/BACKENDS	849	=head1 SUPPORTED EVENT LOOPS/BACKENDS
764		850
…		…
767	=over 4	853	=over 4
768		854
769	=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.
770		856
771	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
772	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
773	that, will fall back to its own pure-perl implementation, which is	859	pure-perl implementation, which is available everywhere as it comes with
774	available everywhere as it comes with AnyEvent itself.	860	AnyEvent itself.
775		861
776	AnyEvent::Impl::EV based on EV (interface to libev, best choice).	862	AnyEvent::Impl::EV based on EV (interface to libev, best choice).
777	AnyEvent::Impl::Event based on Event, very stable, few glitches.
778	AnyEvent::Impl::Perl pure-perl implementation, fast and portable.	863	AnyEvent::Impl::Perl pure-perl implementation, fast and portable.
779		864
780	=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.
781		866
782	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
783	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
784	them. This means that AnyEvent will automatically pick the right backend	869	them. This means that AnyEvent will automatically pick the right backend
785	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
786	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.
787		872
		873	AnyEvent::Impl::Event based on Event, very stable, few glitches.
788	AnyEvent::Impl::Glib based on Glib, slow but very stable.	874	AnyEvent::Impl::Glib based on Glib, slow but very stable.
789	AnyEvent::Impl::Tk based on Tk, very broken.	875	AnyEvent::Impl::Tk based on Tk, very broken.
790	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.	876	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
791	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.
792		879
793	=item Backends with special needs.	880	=item Backends with special needs.
794		881
795	Qt requires the Qt::Application to be instantiated first, but will	882	Qt requires the Qt::Application to be instantiated first, but will
796	otherwise be picked up automatically. As long as the main program	883	otherwise be picked up automatically. As long as the main program
…		…
870	event module detection too early, for example, L<AnyEvent::AIO> creates	957	event module detection too early, for example, L<AnyEvent::AIO> creates
871	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
872	avoid autodetecting the event module at load time.	959	avoid autodetecting the event module at load time.
873		960
874	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
875	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
876	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 ||= $guard;
877		981
878	=item @AnyEvent::post_detect	982	=item @AnyEvent::post_detect
879		983
880	If there are any code references in this array (you can C<push> to it	984	If there are any code references in this array (you can C<push> to it
881	before or after loading AnyEvent), then they will called directly after	985	before or after loading AnyEvent), then they will called directly after
…		…
884	You should check C<$AnyEvent::MODEL> before adding to this array, though:	988	You should check C<$AnyEvent::MODEL> before adding to this array, though:
885	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
886	array will be ignored.	990	array will be ignored.
887		991
888	Best use C<AnyEvent::post_detect { BLOCK }> when your application allows	992	Best use C<AnyEvent::post_detect { BLOCK }> when your application allows
889	it,as it takes care of these details.	993	it, as it takes care of these details.
890		994
891	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
892	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
893	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
894	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	}
895		1012
896	=back	1013	=back
897		1014
898	=head1 WHAT TO DO IN A MODULE	1015	=head1 WHAT TO DO IN A MODULE
899		1016
…		…
956	=head1 OTHER MODULES	1073	=head1 OTHER MODULES
957		1074
958	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
959	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
960	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
961	come with AnyEvent, most are available via CPAN.	1078	come as part of AnyEvent, the others are available via CPAN.
962		1079
963	=over 4	1080	=over 4
964		1081
965	=item L<AnyEvent::Util>	1082	=item L<AnyEvent::Util>
966		1083
…		…
981		1098
982	=item L<AnyEvent::DNS>	1099	=item L<AnyEvent::DNS>
983		1100
984	Provides rich asynchronous DNS resolver capabilities.	1101	Provides rich asynchronous DNS resolver capabilities.
985		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
986	=item L<AnyEvent::HTTP>	1126	=item L<AnyEvent::DBI>
987		1127
988	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,
989	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.
990		1137
991	=item L<AnyEvent::HTTPD>	1138	=item L<AnyEvent::HTTPD>
992		1139
993	Provides a simple web application server framework.	1140	A simple embedded webserver.
994		1141
995	=item L<AnyEvent::FastPing>	1142	=item L<AnyEvent::FastPing>
996		1143
997	The fastest ping in the west.	1144	The fastest ping in the west.
998
999	=item L<AnyEvent::DBI>
1000
1001	Executes L<DBI> requests asynchronously in a proxy process.
1002
1003	=item L<AnyEvent::AIO>
1004
1005	Truly asynchronous I/O, should be in the toolbox of every event
1006	programmer. AnyEvent::AIO transparently fuses L<IO::AIO> and AnyEvent
1007	together.
1008
1009	=item L<AnyEvent::BDB>
1010
1011	Truly asynchronous Berkeley DB access. AnyEvent::BDB transparently fuses
1012	L<BDB> and AnyEvent together.
1013
1014	=item L<AnyEvent::GPSD>
1015
1016	A non-blocking interface to gpsd, a daemon delivering GPS information.
1017
1018	=item L<AnyEvent::IRC>
1019
1020	AnyEvent based IRC client module family (replacing the older Net::IRC3).
1021
1022	=item L<AnyEvent::XMPP>
1023
1024	AnyEvent based XMPP (Jabber protocol) module family (replacing the older
1025	Net::XMPP2>.
1026
1027	=item L<AnyEvent::IGS>
1028
1029	A non-blocking interface to the Internet Go Server protocol (used by
1030	L<App::IGS>).
1031
1032	=item L<Net::FCP>
1033
1034	AnyEvent-based implementation of the Freenet Client Protocol, birthplace
1035	of AnyEvent.
1036
1037	=item L<Event::ExecFlow>
1038
1039	High level API for event-based execution flow control.
1040		1145
1041	=item L<Coro>	1146	=item L<Coro>
1042		1147
1043	Has special support for AnyEvent via L<Coro::AnyEvent>.	1148	Has special support for AnyEvent via L<Coro::AnyEvent>.
1044		1149
…		…
1048		1153
1049	package AnyEvent;	1154	package AnyEvent;
1050		1155
1051	# basically a tuned-down version of common::sense	1156	# basically a tuned-down version of common::sense
1052	sub common_sense {	1157	sub common_sense {
1053	# no warnings	1158	# from common:.sense 1.0
1054	${^WARNING_BITS} ^= ${^WARNING_BITS};	1159	${^WARNING_BITS} = "\xfc\x3f\x33\x00\x0f\xf3\xcf\xc0\xf3\xfc\x33\x00";
1055	# use strict vars subs	1160	# use strict vars subs - NO UTF-8, as Util.pm doesn't like this atm. (uts46data.pl)
1056	$^H |= 0x00000600;	1161	$^H |= 0x00000600;
1057	}	1162	}
1058		1163
1059	BEGIN { AnyEvent::common_sense }	1164	BEGIN { AnyEvent::common_sense }
1060		1165
1061	use Carp ();	1166	use Carp ();
1062		1167
1063	our $VERSION = 4.85;	1168	our $VERSION = '5.27';
1064	our $MODEL;	1169	our $MODEL;
1065		1170
1066	our $AUTOLOAD;	1171	our $AUTOLOAD;
1067	our @ISA;	1172	our @ISA;
1068		1173
1069	our @REGISTRY;	1174	our @REGISTRY;
1070		1175
1071	our $WIN32;
1072
1073	our $VERBOSE;	1176	our $VERBOSE;
1074		1177
1075	BEGIN {	1178	BEGIN {
1076	eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }";	1179	require "AnyEvent/constants.pl";
		1180
1077	eval "sub TAINT(){ " . (${^TAINT}*1) . " }";	1181	eval "sub TAINT (){" . (${^TAINT}*1) . "}";
1078		1182
1079	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}	1183	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}
1080	if ${^TAINT};	1184	if ${^TAINT};
1081		1185
1082	$VERBOSE = $ENV{PERL_ANYEVENT_VERBOSE}*1;	1186	$VERBOSE = $ENV{PERL_ANYEVENT_VERBOSE}*1;
…		…
1093	for reverse split /\s*,\s*/,	1197	for reverse split /\s*,\s*/,
1094	$ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";	1198	$ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";
1095	}	1199	}
1096		1200
1097	my @models = (	1201	my @models = (
1098	[EV:: => AnyEvent::Impl::EV::],	1202	[EV:: => AnyEvent::Impl::EV:: , 1],
1099	[Event:: => AnyEvent::Impl::Event::],
1100	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::],	1203	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl:: , 1],
1101	# everything below here will not be autoprobed	1204	# everything below here will not (normally) be autoprobed
1102	# as the pureperl backend should work everywhere	1205	# as the pureperl backend should work everywhere
1103	# and is usually faster	1206	# and is usually faster
		1207	[Event:: => AnyEvent::Impl::Event::, 1],
1104	[Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers	1208	[Glib:: => AnyEvent::Impl::Glib:: , 1], # becomes extremely slow with many watchers
1105	[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
1106	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles	1211	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
1107	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program	1212	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program
1108	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza	1213	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
1109	[Wx:: => AnyEvent::Impl::POE::],	1214	[Wx:: => AnyEvent::Impl::POE::],
1110	[Prima:: => AnyEvent::Impl::POE::],	1215	[Prima:: => AnyEvent::Impl::POE::],
1111	# 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
1112	# byzantine signal and broken child handling, among others.	1217	# byzantine signal and broken child handling, among others.
1113	# 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
1114	# obvious default class.	1219	# obvious default class.
1115	# [IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program	1220	[IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program
1116	# [IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program	1221	[IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program
1117	# [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
1118	);	1224	);
1119		1225
1120	our %method = map +($_ => 1),	1226	our %method = map +($_ => 1),
1121	qw(io timer time now now_update signal child idle condvar one_event DESTROY);	1227	qw(io timer time now now_update signal child idle condvar one_event DESTROY);
1122		1228
1123	our @post_detect;	1229	our @post_detect;
1124		1230
1125	sub post_detect(&) {	1231	sub post_detect(&) {
1126	my ($cb) = @_;	1232	my ($cb) = @_;
1127		1233
1128	if ($MODEL) {
1129	$cb->();
1130
1131	1
1132	} else {
1133	push @post_detect, $cb;	1234	push @post_detect, $cb;
1134		1235
1135	defined wantarray	1236	defined wantarray
1136	? bless \$cb, "AnyEvent::Util::postdetect"	1237	? bless \$cb, "AnyEvent::Util::postdetect"
1137	: ()	1238	: ()
1138	}
1139	}	1239	}
1140		1240
1141	sub AnyEvent::Util::postdetect::DESTROY {	1241	sub AnyEvent::Util::postdetect::DESTROY {
1142	@post_detect = grep $_ != ${$_[0]}, @post_detect;	1242	@post_detect = grep $_ != ${$_[0]}, @post_detect;
1143	}	1243	}
1144		1244
1145	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 $VERBOSE;
		1259	}
		1260	}
		1261
		1262	# check for already loaded models
1146	unless ($MODEL) {	1263	unless ($MODEL) {
1147	local $SIG{__DIE__};	1264	for (@REGISTRY, @models) {
1148		1265	my ($package, $model) = @$_;
1149	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {	1266	if (${"$package\::VERSION"} > 0) {
1150	my $model = "AnyEvent::Impl::$1";
1151	if (eval "require $model") {	1267	if (eval "require $model") {
1152	$MODEL = $model;	1268	$MODEL = $model;
1153	warn "AnyEvent: loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.\n" if $VERBOSE >= 2;	1269	warn "AnyEvent: autodetected model '$model', using it.\n" if $VERBOSE >= 2;
1154	} else {	1270	last;
1155	warn "AnyEvent: unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@" if $VERBOSE;	1271	}
1156	}	1272	}
1157	}	1273	}
1158		1274
1159	# check for already loaded models
1160	unless ($MODEL) {	1275	unless ($MODEL) {
		1276	# try to autoload a model
1161	for (@REGISTRY, @models) {	1277	for (@REGISTRY, @models) {
1162	my ($package, $model) = @$_;	1278	my ($package, $model, $autoload) = @$_;
		1279	if (
		1280	$autoload
		1281	and eval "require $package"
1163	if (${"$package\::VERSION"} > 0) {	1282	and ${"$package\::VERSION"} > 0
1164	if (eval "require $model") {	1283	and eval "require $model"
		1284	) {
1165	$MODEL = $model;	1285	$MODEL = $model;
1166	warn "AnyEvent: autodetected model '$model', using it.\n" if $VERBOSE >= 2;	1286	warn "AnyEvent: autoloaded model '$model', using it.\n" if $VERBOSE >= 2;
1167	last;	1287	last;
1168	}
1169	}	1288	}
1170	}	1289	}
1171		1290
1172	unless ($MODEL) {
1173	# try to load a model
1174
1175	for (@REGISTRY, @models) {
1176	my ($package, $model) = @$_;
1177	if (eval "require $package"
1178	and ${"$package\::VERSION"} > 0
1179	and eval "require $model") {
1180	$MODEL = $model;
1181	warn "AnyEvent: autoprobed model '$model', using it.\n" if $VERBOSE >= 2;
1182	last;
1183	}
1184	}
1185
1186	$MODEL	1291	$MODEL
1187	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.\n";	1292	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.\n";
1188	}
1189	}	1293	}
1190
1191	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
1192
1193	unshift @ISA, $MODEL;
1194
1195	require AnyEvent::Strict if $ENV{PERL_ANYEVENT_STRICT};
1196
1197	(shift @post_detect)->() while @post_detect;
1198	}	1294	}
		1295
		1296	@models = (); # free probe data
		1297
		1298	push @{"$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	};
1199		1317
1200	$MODEL	1318	$MODEL
1201	}	1319	}
1202		1320
1203	sub AUTOLOAD {	1321	sub AUTOLOAD {
1204	(my $func = $AUTOLOAD) =~ s/.*://;	1322	(my $func = $AUTOLOAD) =~ s/.*://;
1205		1323
1206	$method{$func}	1324	$method{$func}
1207	or Carp::croak "$func: not a valid method for AnyEvent objects";	1325	or Carp::croak "$func: not a valid AnyEvent class method";
1208		1326
1209	detect unless $MODEL;	1327	detect;
1210		1328
1211	my $class = shift;	1329	my $class = shift;
1212	$class->$func (@_);	1330	$class->$func (@_);
1213	}	1331	}
1214		1332
…		…
1227	# 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
1228		1346
1229	($fh2, $rw)	1347	($fh2, $rw)
1230	}	1348	}
1231		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
1232	package AnyEvent::Base;	1403	package AnyEvent::Base;
1233		1404
1234	# default implementations for many methods	1405	# default implementations for many methods
1235		1406
1236	sub _time {	1407	sub time {
		1408	eval q{ # poor man's autoloading {}
1237	# probe for availability of Time::HiRes	1409	# probe for availability of Time::HiRes
1238	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {	1410	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {
1239	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;
1240	*_time = \&Time::HiRes::time;	1412	*AE::time = \&Time::HiRes::time;
1241	# if (eval "use POSIX (); (POSIX::times())...	1413	# if (eval "use POSIX (); (POSIX::times())...
1242	} else {	1414	} else {
1243	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;
1244	*_time = sub { time }; # epic fail	1416	*AE::time = sub (){ time }; # epic fail
		1417	}
		1418
		1419	*time = sub { AE::time }; # different prototypes
1245	}	1420	};
		1421	die if $@;
1246		1422
1247	&_time	1423	&time
1248	}	1424	}
1249		1425
1250	sub time { _time }	1426	*now = \&time;
1251	sub now { _time }	1427
1252	sub now_update { }	1428	sub now_update { }
1253		1429
1254	# default implementation for ->condvar	1430	# default implementation for ->condvar
1255		1431
1256	sub condvar {	1432	sub condvar {
		1433	eval q{ # poor man's autoloading {}
		1434	*condvar = sub {
1257	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
1258	}	1445	}
1259		1446
1260	# default implementation for ->signal	1447	# default implementation for ->signal
1261		1448
1262	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	$HAVE_ASYNC_INTERRUPT
		1457	}
		1458
1263	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);	1459	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);
1264	our (%SIG_ASY, %SIG_ASY_W);	1460	our (%SIG_ASY, %SIG_ASY_W);
1265	our ($SIG_COUNT, $SIG_TW);	1461	our ($SIG_COUNT, $SIG_TW);
1266		1462
1267	sub _signal_exec {
1268	$HAVE_ASYNC_INTERRUPT
1269	? $SIGPIPE_R->drain
1270	: sysread $SIGPIPE_R, my $dummy, 9;
1271
1272	while (%SIG_EV) {
1273	for (keys %SIG_EV) {
1274	delete $SIG_EV{$_};
1275	$_->() for values %{ $SIG_CB{$_} || {} };
1276	}
1277	}
1278	}
1279
1280	# 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
1281	sub _sig_add() {	1465	sub _sig_add() {
1282	unless ($SIG_COUNT++) {	1466	unless ($SIG_COUNT++) {
1283	# try to align timer on a full-second boundary, if possible	1467	# try to align timer on a full-second boundary, if possible
1284	my $NOW = AnyEvent->now;	1468	my $NOW = AE::now;
1285		1469
1286	$SIG_TW = AnyEvent->timer (	1470	$SIG_TW = AE::timer
1287	after => $MAX_SIGNAL_LATENCY - ($NOW - int $NOW),	1471	$MAX_SIGNAL_LATENCY - ($NOW - int $NOW),
1288	interval => $MAX_SIGNAL_LATENCY,	1472	$MAX_SIGNAL_LATENCY,
1289	cb => sub { }, # just for the PERL_ASYNC_CHECK	1473	sub { } # just for the PERL_ASYNC_CHECK
1290	);	1474	;
1291	}	1475	}
1292	}	1476	}
1293		1477
1294	sub _sig_del {	1478	sub _sig_del {
1295	undef $SIG_TW	1479	undef $SIG_TW
1296	unless --$SIG_COUNT;	1480	unless --$SIG_COUNT;
1297	}	1481	}
1298		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
1299	sub _signal {	1514	sub signal {
1300	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;
1301		1519
1302	my $signal = uc $arg{signal}	1520	$SIGPIPE_R = new Async::Interrupt::EventPipe;
1303	or Carp::croak "required option 'signal' is missing";	1521	$SIG_IO = AE::io $SIGPIPE_R->fileno, 0, \&_signal_exec;
1304		1522
1305	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};	1523	} else {
		1524	warn "AnyEvent: using emulated perl signal handling with latency timer.\n" if $VERBOSE >= 8;
1306		1525
1307	if ($HAVE_ASYNC_INTERRUPT) {	1526	if (AnyEvent::WIN32) {
1308	# async::interrupt	1527	require AnyEvent::Util;
1309		1528
1310	$SIG_ASY{$signal} ||= do {	1529	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
1311	my $asy = new Async::Interrupt	1530	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R, 1) if $SIGPIPE_R;
1312	cb => sub { undef $SIG_EV{$signal} },	1531	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W, 1) if $SIGPIPE_W; # just in case
1313	signal => $signal,	1532	} else {
1314	pipe => [$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;
1315	;	1540	}
1316	$asy->pipe_autodrain (0);
1317		1541
1318	$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} };
1319	};	1600	};
1320		1601
1321	} else {	1602	*_signal_exec = sub {
1322	# pure perl	1603	$HAVE_ASYNC_INTERRUPT
		1604	? $SIGPIPE_R->drain
		1605	: sysread $SIGPIPE_R, (my $dummy), 9;
1323		1606
1324	$SIG{$signal} ||= sub {	1607	while (%SIG_EV) {
1325	local $!;	1608	for (keys %SIG_EV) {
1326	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;	1609	delete $SIG_EV{$_};
1327	undef $SIG_EV{$signal};	1610	$_->() for values %{ $SIG_CB{$_} || {} };
		1611	}
		1612	}
1328	};	1613	};
1329
1330	# can't do signal processing without introducing races in pure perl,
1331	# so limit the signal latency.
1332	_sig_add;
1333	}	1614	};
		1615	die if $@;
1334		1616
1335	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
1336	}
1337
1338	sub signal {
1339	# probe for availability of Async::Interrupt
1340	if (!$ENV{PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT} && eval "use Async::Interrupt 0.6 (); 1") {
1341	warn "AnyEvent: using Async::Interrupt for race-free signal handling.\n" if $VERBOSE >= 8;
1342
1343	$HAVE_ASYNC_INTERRUPT = 1;
1344	$SIGPIPE_R = new Async::Interrupt::EventPipe;
1345	$SIG_IO = AnyEvent->io (fh => $SIGPIPE_R->fileno, poll => "r", cb => \&_signal_exec);
1346
1347	} else {
1348	warn "AnyEvent: using emulated perl signal handling with latency timer.\n" if $VERBOSE >= 8;
1349
1350	require Fcntl;
1351
1352	if (AnyEvent::WIN32) {
1353	require AnyEvent::Util;
1354
1355	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
1356	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R) if $SIGPIPE_R;
1357	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W) if $SIGPIPE_W; # just in case
1358	} else {
1359	pipe $SIGPIPE_R, $SIGPIPE_W;
1360	fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R;
1361	fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case
1362
1363	# not strictly required, as $^F is normally 2, but let's make sure...
1364	fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
1365	fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
1366	}
1367
1368	$SIGPIPE_R
1369	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";
1370
1371	$SIG_IO = AnyEvent->io (fh => $SIGPIPE_R, poll => "r", cb => \&_signal_exec);
1372	}
1373
1374	*signal = \&_signal;
1375	&signal	1617	&signal
1376	}
1377
1378	sub AnyEvent::Base::signal::DESTROY {
1379	my ($signal, $cb) = @{$_[0]};
1380
1381	_sig_del;
1382
1383	delete $SIG_CB{$signal}{$cb};
1384
1385	$HAVE_ASYNC_INTERRUPT
1386	? delete $SIG_ASY{$signal}
1387	: # delete doesn't work with older perls - they then
1388	# print weird messages, or just unconditionally exit
1389	# instead of getting the default action.
1390	undef $SIG{$signal}
1391	unless keys %{ $SIG_CB{$signal} };
1392	}	1618	}
1393		1619
1394	# default implementation for ->child	1620	# default implementation for ->child
1395		1621
1396	our %PID_CB;	1622	our %PID_CB;
1397	our $CHLD_W;	1623	our $CHLD_W;
1398	our $CHLD_DELAY_W;	1624	our $CHLD_DELAY_W;
1399	our $WNOHANG;	1625	our $WNOHANG;
1400		1626
1401	sub _sigchld {	1627	# used by many Impl's
1402	while (0 < (my $pid = waitpid -1, $WNOHANG)) {	1628	sub _emit_childstatus($$) {
1403	$_->($pid, $?)	1629	my (undef, $rpid, $rstatus) = @_;
		1630
		1631	$_->($rpid, $rstatus)
1404	for values %{ $PID_CB{$pid} || {} },	1632	for values %{ $PID_CB{$rpid} || {} },
1405	values %{ $PID_CB{0} || {} };	1633	values %{ $PID_CB{0} || {} };
1406	}
1407	}	1634	}
1408		1635
1409	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 {
1410	my (undef, %arg) = @_;	1646	my (undef, %arg) = @_;
1411		1647
1412	defined (my $pid = $arg{pid} + 0)	1648	defined (my $pid = $arg{pid} + 0)
1413	or Carp::croak "required option 'pid' is missing";	1649	or Carp::croak "required option 'pid' is missing";
1414		1650
1415	$PID_CB{$pid}{$arg{cb}} = $arg{cb};	1651	$PID_CB{$pid}{$arg{cb}} = $arg{cb};
1416		1652
1417	# WNOHANG is almost cetrainly 1 everywhere	1653	# WNOHANG is almost cetrainly 1 everywhere
1418	$WNOHANG ||= $^O =~ /^(?:openbsd|netbsd|linux|freebsd|cygwin|MSWin32)$/	1654	$WNOHANG ||= $^O =~ /^(?:openbsd|netbsd|linux|freebsd|cygwin|MSWin32)$/
1419	? 1	1655	? 1
1420	: eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1;	1656	: eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1;
1421		1657
1422	unless ($CHLD_W) {	1658	unless ($CHLD_W) {
1423	$CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld);	1659	$CHLD_W = AE::signal CHLD => \&_sigchld;
1424	# 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
1425	&_sigchld;	1661	&_sigchld;
1426	}	1662	}
1427		1663
1428	bless [$pid, $arg{cb}], "AnyEvent::Base::child"	1664	bless [$pid, $arg{cb}], "AnyEvent::Base::child"
1429	}	1665	};
1430		1666
1431	sub AnyEvent::Base::child::DESTROY {	1667	*AnyEvent::Base::child::DESTROY = sub {
1432	my ($pid, $cb) = @{$_[0]};	1668	my ($pid, $cb) = @{$_[0]};
1433		1669
1434	delete $PID_CB{$pid}{$cb};	1670	delete $PID_CB{$pid}{$cb};
1435	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };	1671	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };
1436		1672
1437	undef $CHLD_W unless keys %PID_CB;	1673	undef $CHLD_W unless keys %PID_CB;
		1674	};
		1675	};
		1676	die if $@;
		1677
		1678	&child
1438	}	1679	}
1439		1680
1440	# idle emulation is done by simply using a timer, regardless	1681	# idle emulation is done by simply using a timer, regardless
1441	# of whether the process is idle or not, and not letting	1682	# of whether the process is idle or not, and not letting
1442	# the callback use more than 50% of the time.	1683	# the callback use more than 50% of the time.
1443	sub idle {	1684	sub idle {
		1685	eval q{ # poor man's autoloading {}
		1686	*idle = sub {
1444	my (undef, %arg) = @_;	1687	my (undef, %arg) = @_;
1445		1688
1446	my ($cb, $w, $rcb) = $arg{cb};	1689	my ($cb, $w, $rcb) = $arg{cb};
1447		1690
1448	$rcb = sub {	1691	$rcb = sub {
1449	if ($cb) {	1692	if ($cb) {
1450	$w = _time;	1693	$w = _time;
1451	&$cb;	1694	&$cb;
1452	$w = _time - $w;	1695	$w = _time - $w;
1453		1696
1454	# 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,
1455	# within some limits	1698	# within some limits
1456	$w = 0.0001 if $w < 0.0001;	1699	$w = 0.0001 if $w < 0.0001;
1457	$w = 5 if $w > 5;	1700	$w = 5 if $w > 5;
1458		1701
1459	$w = AnyEvent->timer (after => $w, cb => $rcb);	1702	$w = AE::timer $w, 0, $rcb;
1460	} else {	1703	} else {
1461	# clean up...	1704	# clean up...
1462	undef $w;	1705	undef $w;
1463	undef $rcb;	1706	undef $rcb;
		1707	}
		1708	};
		1709
		1710	$w = AE::timer 0.05, 0, $rcb;
		1711
		1712	bless \\$cb, "AnyEvent::Base::idle"
1464	}	1713	};
		1714
		1715	*AnyEvent::Base::idle::DESTROY = sub {
		1716	undef $${$_[0]};
		1717	};
1465	};	1718	};
		1719	die if $@;
1466		1720
1467	$w = AnyEvent->timer (after => 0.05, cb => $rcb);	1721	&idle
1468
1469	bless \\$cb, "AnyEvent::Base::idle"
1470	}
1471
1472	sub AnyEvent::Base::idle::DESTROY {
1473	undef $${$_[0]};
1474	}	1722	}
1475		1723
1476	package AnyEvent::CondVar;	1724	package AnyEvent::CondVar;
1477		1725
1478	our @ISA = AnyEvent::CondVar::Base::;	1726	our @ISA = AnyEvent::CondVar::Base::;
…		…
1526	Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak};	1774	Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak};
1527	wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0]	1775	wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0]
1528	}	1776	}
1529		1777
1530	sub cb {	1778	sub cb {
1531	$_[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
1532	$_[0]{_ae_cb}	1786	$cv->{_ae_cb}
1533	}	1787	}
1534		1788
1535	sub begin {	1789	sub begin {
1536	++$_[0]{_ae_counter};	1790	++$_[0]{_ae_counter};
1537	$_[0]{_ae_end_cb} = $_[1] if @_ > 1;	1791	$_[0]{_ae_end_cb} = $_[1] if @_ > 1;
…		…
1746	warn "read: $input\n"; # output what has been read	2000	warn "read: $input\n"; # output what has been read
1747	$cv->send if $input =~ /^q/i; # quit program if /^q/i	2001	$cv->send if $input =~ /^q/i; # quit program if /^q/i
1748	},	2002	},
1749	);	2003	);
1750		2004
1751	my $time_watcher; # can only be used once
1752
1753	sub new_timer {
1754	$timer = AnyEvent->timer (after => 1, cb => sub {	2005	my $time_watcher = AnyEvent->timer (after => 1, interval => 1, cb => sub {
1755	warn "timeout\n"; # print 'timeout' about every second	2006	warn "timeout\n"; # print 'timeout' at most every second
1756	&new_timer; # and restart the time
1757	});	2007	});
1758	}
1759
1760	new_timer; # create first timer
1761		2008
1762	$cv->recv; # wait until user enters /^q/i	2009	$cv->recv; # wait until user enters /^q/i
1763		2010
1764	=head1 REAL-WORLD EXAMPLE	2011	=head1 REAL-WORLD EXAMPLE
1765		2012
…		…
1838		2085
1839	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)
1840	that occurred during request processing. The C<result> method detects	2087	that occurred during request processing. The C<result> method detects
1841	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)
1842	and just throws the exception, which means connection errors and other	2089	and just throws the exception, which means connection errors and other
1843	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
1844	random callback.	2091	random callback.
1845		2092
1846	All of this enables the following usage styles:	2093	All of this enables the following usage styles:
1847		2094
1848	1. Blocking:	2095	1. Blocking:
…		…
1896	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
1897	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,
1898	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.
1899		2146
1900	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
1901	distribution.	2148	distribution. It uses the L<AE> interface, which makes a real difference
		2149	for the EV and Perl backends only.
1902		2150
1903	=head3 Explanation of the columns	2151	=head3 Explanation of the columns
1904		2152
1905	I<watcher> is the number of event watchers created/destroyed. Since	2153	I<watcher> is the number of event watchers created/destroyed. Since
1906	different event models feature vastly different performances, each event	2154	different event models feature vastly different performances, each event
…		…
1927	watcher.	2175	watcher.
1928		2176
1929	=head3 Results	2177	=head3 Results
1930		2178
1931	name watchers bytes create invoke destroy comment	2179	name watchers bytes create invoke destroy comment
1932	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
1933	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
1934	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
1935	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
1936	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
1937	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
1938	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
1939	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
1940	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
1941	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
1942	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
1943	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
1944		2192
1945	=head3 Discussion	2193	=head3 Discussion
1946		2194
1947	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
1948	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)
…		…
1960	benchmark machine, handling an event takes roughly 1600 CPU cycles with	2208	benchmark machine, handling an event takes roughly 1600 CPU cycles with
1961	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
1962	cycles with POE.	2210	cycles with POE.
1963		2211
1964	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
1965	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
1966	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).
1967	natively.
1968		2217
1969	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
1970	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
1971	interpreter and the backend itself). Nevertheless this shows that it	2220	interpreter and the backend itself). Nevertheless this shows that it
1972	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
…		…
2046	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
2047	(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
2048	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.
2049		2298
2050	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
2051	distribution.	2300	distribution. It uses the L<AE> interface, which makes a real difference
		2301	for the EV and Perl backends only.
2052		2302
2053	=head3 Explanation of the columns	2303	=head3 Explanation of the columns
2054		2304
2055	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
2056	each server has a read and write socket end).	2306	each server has a read and write socket end).
…		…
2064	a new one that moves the timeout into the future.	2314	a new one that moves the timeout into the future.
2065		2315
2066	=head3 Results	2316	=head3 Results
2067		2317
2068	name sockets create request	2318	name sockets create request
2069	EV 20000 69.01 11.16	2319	EV 20000 62.66 7.99
2070	Perl 20000 73.32 35.87	2320	Perl 20000 68.32 32.64
2071	IOAsync 20000 157.00 98.14 epoll	2321	IOAsync 20000 174.06 101.15 epoll
2072	IOAsync 20000 159.31 616.06 poll	2322	IOAsync 20000 174.67 610.84 poll
2073	Event 20000 212.62 257.32	2323	Event 20000 202.69 242.91
2074	Glib 20000 651.16 1896.30	2324	Glib 20000 557.01 1689.52
2075	POE 20000 349.67 12317.24 uses POE::Loop::Event	2325	POE 20000 341.54 12086.32 uses POE::Loop::Event
2076		2326
2077	=head3 Discussion	2327	=head3 Discussion
2078		2328
2079	This benchmark I<does> measure scalability and overall performance of the	2329	This benchmark I<does> measure scalability and overall performance of the
2080	particular event loop.	2330	particular event loop.
…		…
2206	As you can see, the AnyEvent + EV combination even beats the	2456	As you can see, the AnyEvent + EV combination even beats the
2207	hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl	2457	hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl
2208	backend easily beats IO::Lambda and POE.	2458	backend easily beats IO::Lambda and POE.
2209		2459
2210	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
2211	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
2212	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
2213	in a non-blocking way.	2463	it does all of DNS, tcp-connect and socket I/O in a non-blocking way.
2214		2464
2215	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
2216	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
2217	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.
2218		2468
2219		2469
2220	=head1 SIGNALS	2470	=head1 SIGNALS
2221		2471
2222	AnyEvent currently installs handlers for these signals:	2472	AnyEvent currently installs handlers for these signals:
…		…
2264	it's built-in modules) are required to use it.	2514	it's built-in modules) are required to use it.
2265		2515
2266	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
2267	modules if they are installed.	2517	modules if they are installed.
2268		2518
2269	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
2270	affect AnyEvent's operetion.	2520	affect AnyEvent's operation.
2271		2521
2272	=over 4	2522	=over 4
2273		2523
2274	=item L<Async::Interrupt>	2524	=item L<Async::Interrupt>
2275		2525
…		…
2280	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
2281	C<$AnyEvent::MAX_SIGNAL_LATENCY>).	2531	C<$AnyEvent::MAX_SIGNAL_LATENCY>).
2282		2532
2283	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
2284	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
2285	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
2286	battery life on laptops).	2536	battery life on laptops).
2287		2537
2288	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
2289	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).
2290		2540
…		…
2302	automatic timer adjustments even when no monotonic clock is available,	2552	automatic timer adjustments even when no monotonic clock is available,
2303	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
2304	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
2305	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>).
2306		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
2307	=item L<Guard>	2560	=item L<Guard>
2308		2561
2309	The guard module, when used, will be used to implement	2562	The guard module, when used, will be used to implement
2310	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
2311	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
2312	purely used for performance.	2565	purely used for performance.
2313		2566
2314	=item L<JSON> and L<JSON::XS>	2567	=item L<JSON> and L<JSON::XS>
2315		2568
2316	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
2317	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
2318	advantage of the ulta-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.
2319
2320	In fact, L<AnyEvent::Handle> will use L<JSON::XS> by default if it is
2321	installed.
2322		2572
2323	=item L<Net::SSLeay>	2573	=item L<Net::SSLeay>
2324		2574
2325	Implementing TLS/SSL in Perl is certainly interesting, but not very	2575	Implementing TLS/SSL in Perl is certainly interesting, but not very
2326	worthwhile: If this module is installed, then L<AnyEvent::Handle> (with	2576	worthwhile: If this module is installed, then L<AnyEvent::Handle> (with
…		…
2337		2587
2338		2588
2339	=head1 FORK	2589	=head1 FORK
2340		2590
2341	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
2342	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
2343	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).
2344		2603
2345	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
2346	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
2347	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.
2348		2616
2349		2617
2350	=head1 SECURITY CONSIDERATIONS	2618	=head1 SECURITY CONSIDERATIONS
2351		2619
2352	AnyEvent can be forced to load any event model via	2620	AnyEvent can be forced to load any event model via
…		…
2390	L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.	2658	L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.
2391		2659
2392	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,	2660	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,
2393	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>,
2394	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,	2662	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,
2395	L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>.	2663	L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>, L<Anyevent::Impl::Irssi>.
2396		2664
2397	Non-blocking file handles, sockets, TCP clients and	2665	Non-blocking file handles, sockets, TCP clients and
2398	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.	2666	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.
2399		2667
2400	Asynchronous DNS: L<AnyEvent::DNS>.	2668	Asynchronous DNS: L<AnyEvent::DNS>.

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