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Revision 1.239 by root, Thu Jul 16 20:55:38 2009 UTC vs.
Revision 1.323 by root, Thu May 20 21:22:20 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
…		…
361	invocation, and callback invocation will be synchronous. Synchronous means	395	invocation, and callback invocation will be synchronous. Synchronous means
362	that it might take a while until the signal gets handled by the process,	396	that it might take a while until the signal gets handled by the process,
363	but it is guaranteed not to interrupt any other callbacks.	397	but it is guaranteed not to interrupt any other callbacks.
364		398
365	The main advantage of using these watchers is that you can share a signal	399	The main advantage of using these watchers is that you can share a signal
366	between multiple watchers.	400	between multiple watchers, and AnyEvent will ensure that signals will not
		401	interrupt your program at bad times.
367		402
368	This watcher might use C<%SIG>, so programs overwriting those signals	403	This watcher might use C<%SIG> (depending on the event loop used),
369	directly will likely not work correctly.	404	so programs overwriting those signals directly will likely not work
		405	correctly.
370		406
371	Example: exit on SIGINT	407	Example: exit on SIGINT
372		408
373	my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });	409	my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });
374		410
		411	=head3 Restart Behaviour
		412
		413	While restart behaviour is up to the event loop implementation, most will
		414	not restart syscalls (that includes L<Async::Interrupt> and AnyEvent's
		415	pure perl implementation).
		416
		417	=head3 Safe/Unsafe Signals
		418
		419	Perl signals can be either "safe" (synchronous to opcode handling) or
		420	"unsafe" (asynchronous) - the former might get delayed indefinitely, the
		421	latter might corrupt your memory.
		422
		423	AnyEvent signal handlers are, in addition, synchronous to the event loop,
		424	i.e. they will not interrupt your running perl program but will only be
		425	called as part of the normal event handling (just like timer, I/O etc.
		426	callbacks, too).
		427
		428	=head3 Signal Races, Delays and Workarounds
		429
		430	Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support attaching
		431	callbacks to signals in a generic way, which is a pity, as you cannot
		432	do race-free signal handling in perl, requiring C libraries for
		433	this. AnyEvent will try to do it's best, which means in some cases,
		434	signals will be delayed. The maximum time a signal might be delayed is
		435	specified in C<$AnyEvent::MAX_SIGNAL_LATENCY> (default: 10 seconds). This
		436	variable can be changed only before the first signal watcher is created,
		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
		439	will cause fewer spurious wake-ups, which is better for power and CPU
		440	saving.
		441
		442	All these problems can be avoided by installing the optional
		443	L<Async::Interrupt> module, which works with most event loops. It will not
		444	work with inherently broken event loops such as L<Event> or L<Event::Lib>
		445	(and not with L<POE> currently, as POE does it's own workaround with
		446	one-second latency). For those, you just have to suffer the delays.
		447
375	=head2 CHILD PROCESS WATCHERS	448	=head2 CHILD PROCESS WATCHERS
376		449
		450	$w = AnyEvent->child (pid => <process id>, cb => <callback>);
		451
377	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.
378		453
379	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,
380	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
381	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
382	any trace events (stopped/continued).	457	finished and an exit status is available, not on any trace events
		458	(stopped/continued).
383		459
384	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
385	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
386	callback arguments.	462	callback arguments.
387		463
…		…
403		479
404	This means you cannot create a child watcher as the very first	480	This means you cannot create a child watcher as the very first
405	thing in an AnyEvent program, you I<have> to create at least one	481	thing in an AnyEvent program, you I<have> to create at least one
406	watcher before you C<fork> the child (alternatively, you can call	482	watcher before you C<fork> the child (alternatively, you can call
407	C<AnyEvent::detect>).	483	C<AnyEvent::detect>).
		484
		485	As most event loops do not support waiting for child events, they will be
		486	emulated by AnyEvent in most cases, in which the latency and race problems
		487	mentioned in the description of signal watchers apply.
408		488
409	Example: fork a process and wait for it	489	Example: fork a process and wait for it
410		490
411	my $done = AnyEvent->condvar;	491	my $done = AnyEvent->condvar;
412		492
…		…
424	# do something else, then wait for process exit	504	# do something else, then wait for process exit
425	$done->recv;	505	$done->recv;
426		506
427	=head2 IDLE WATCHERS	507	=head2 IDLE WATCHERS
428		508
429	Sometimes there is a need to do something, but it is not so important	509	$w = AnyEvent->idle (cb => <callback>);
430	to do it instantly, but only when there is nothing better to do. This
431	"nothing better to do" is usually defined to be "no other events need
432	attention by the event loop".
433		510
434	Idle watchers ideally get invoked when the event loop has nothing	511	Repeatedly invoke the callback after the process becomes idle, until
435	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.
436	events. Instead of blocking, the idle watcher is invoked.
437		513
438	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
439	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
440	will simply call the callback "from time to time".	525	will simply call the callback "from time to time".
441		526
442	Example: read lines from STDIN, but only process them when the	527	Example: read lines from STDIN, but only process them when the
443	program is otherwise idle:	528	program is otherwise idle:
…		…
459	});	544	});
460	});	545	});
461		546
462	=head2 CONDITION VARIABLES	547	=head2 CONDITION VARIABLES
463		548
		549	$cv = AnyEvent->condvar;
		550
		551	$cv->send (<list>);
		552	my @res = $cv->recv;
		553
464	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
465	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
466	will actively watch for new events and call your callbacks.	556	will actively watch for new events and call your callbacks.
467		557
468	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
…		…
487	Condition variables are similar to callbacks, except that you can	577	Condition variables are similar to callbacks, except that you can
488	optionally wait for them. They can also be called merge points - points	578	optionally wait for them. They can also be called merge points - points
489	in time where multiple outstanding events have been processed. And yet	579	in time where multiple outstanding events have been processed. And yet
490	another way to call them is transactions - each condition variable can be	580	another way to call them is transactions - each condition variable can be
491	used to represent a transaction, which finishes at some point and delivers	581	used to represent a transaction, which finishes at some point and delivers
492	a result.	582	a result. And yet some people know them as "futures" - a promise to
		583	compute/deliver something that you can wait for.
493		584
494	Condition variables are very useful to signal that something has finished,	585	Condition variables are very useful to signal that something has finished,
495	for example, if you write a module that does asynchronous http requests,	586	for example, if you write a module that does asynchronous http requests,
496	then a condition variable would be the ideal candidate to signal the	587	then a condition variable would be the ideal candidate to signal the
497	availability of results. The user can either act when the callback is	588	availability of results. The user can either act when the callback is
…		…
518	eventually calls C<< -> send >>, and the "consumer side", which waits	609	eventually calls C<< -> send >>, and the "consumer side", which waits
519	for the send to occur.	610	for the send to occur.
520		611
521	Example: wait for a timer.	612	Example: wait for a timer.
522		613
523	# wait till the result is ready	614	# condition: "wait till the timer is fired"
524	my $result_ready = AnyEvent->condvar;	615	my $timer_fired = AnyEvent->condvar;
525		616
526	# do something such as adding a timer	617	# create the timer - we could wait for, say
527	# or socket watcher the calls $result_ready->send	618	# a handle becomign ready, or even an
528	# when the "result" is ready.	619	# AnyEvent::HTTP request to finish, but
529	# in this case, we simply use a timer:	620	# in this case, we simply use a timer:
530	my $w = AnyEvent->timer (	621	my $w = AnyEvent->timer (
531	after => 1,	622	after => 1,
532	cb => sub { $result_ready->send },	623	cb => sub { $timer_fired->send },
533	);	624	);
534		625
535	# this "blocks" (while handling events) till the callback	626	# this "blocks" (while handling events) till the callback
536	# calls -<send	627	# calls ->send
537	$result_ready->recv;	628	$timer_fired->recv;
538		629
539	Example: wait for a timer, but take advantage of the fact that condition	630	Example: wait for a timer, but take advantage of the fact that condition
540	variables are also callable directly.	631	variables are also callable directly.
541		632
542	my $done = AnyEvent->condvar;	633	my $done = AnyEvent->condvar;
…		…
605	one. For example, a function that pings many hosts in parallel might want	696	one. For example, a function that pings many hosts in parallel might want
606	to use a condition variable for the whole process.	697	to use a condition variable for the whole process.
607		698
608	Every call to C<< ->begin >> will increment a counter, and every call to	699	Every call to C<< ->begin >> will increment a counter, and every call to
609	C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end	700	C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end
610	>>, the (last) callback passed to C<begin> will be executed. That callback	701	>>, the (last) callback passed to C<begin> will be executed, passing the
611	is I<supposed> to call C<< ->send >>, but that is not required. If no	702	condvar as first argument. That callback is I<supposed> to call C<< ->send
612	callback was set, C<send> will be called without any arguments.	703	>>, but that is not required. If no group callback was set, C<send> will
		704	be called without any arguments.
613		705
614	You can think of C<< $cv->send >> giving you an OR condition (one call	706	You can think of C<< $cv->send >> giving you an OR condition (one call
615	sends), while C<< $cv->begin >> and C<< $cv->end >> giving you an AND	707	sends), while C<< $cv->begin >> and C<< $cv->end >> giving you an AND
616	condition (all C<begin> calls must be C<end>'ed before the condvar sends).	708	condition (all C<begin> calls must be C<end>'ed before the condvar sends).
617		709
…		…
644	begung can potentially be zero:	736	begung can potentially be zero:
645		737
646	my $cv = AnyEvent->condvar;	738	my $cv = AnyEvent->condvar;
647		739
648	my %result;	740	my %result;
649	$cv->begin (sub { $cv->send (\%result) });	741	$cv->begin (sub { shift->send (\%result) });
650		742
651	for my $host (@list_of_hosts) {	743	for my $host (@list_of_hosts) {
652	$cv->begin;	744	$cv->begin;
653	ping_host_then_call_callback $host, sub {	745	ping_host_then_call_callback $host, sub {
654	$result{$host} = ...;	746	$result{$host} = ...;
…		…
729	=item $cb = $cv->cb ($cb->($cv))	821	=item $cb = $cv->cb ($cb->($cv))
730		822
731	This is a mutator function that returns the callback set and optionally	823	This is a mutator function that returns the callback set and optionally
732	replaces it before doing so.	824	replaces it before doing so.
733		825
734	The callback will be called when the condition becomes "true", i.e. when	826	The callback will be called when the condition becomes (or already was)
735	C<send> or C<croak> are called, with the only argument being the condition	827	"true", i.e. when C<send> or C<croak> are called (or were called), with
736	variable itself. Calling C<recv> inside the callback or at any later time	828	the only argument being the condition variable itself. Calling C<recv>
737	is guaranteed not to block.	829	inside the callback or at any later time is guaranteed not to block.
738		830
739	=back	831	=back
740		832
741	=head1 SUPPORTED EVENT LOOPS/BACKENDS	833	=head1 SUPPORTED EVENT LOOPS/BACKENDS
742		834
…		…
745	=over 4	837	=over 4
746		838
747	=item Backends that are autoprobed when no other event loop can be found.	839	=item Backends that are autoprobed when no other event loop can be found.
748		840
749	EV is the preferred backend when no other event loop seems to be in	841	EV is the preferred backend when no other event loop seems to be in
750	use. If EV is not installed, then AnyEvent will try Event, and, failing	842	use. If EV is not installed, then AnyEvent will fall back to its own
751	that, will fall back to its own pure-perl implementation, which is	843	pure-perl implementation, which is available everywhere as it comes with
752	available everywhere as it comes with AnyEvent itself.	844	AnyEvent itself.
753		845
754	AnyEvent::Impl::EV based on EV (interface to libev, best choice).	846	AnyEvent::Impl::EV based on EV (interface to libev, best choice).
755	AnyEvent::Impl::Event based on Event, very stable, few glitches.
756	AnyEvent::Impl::Perl pure-perl implementation, fast and portable.	847	AnyEvent::Impl::Perl pure-perl implementation, fast and portable.
757		848
758	=item Backends that are transparently being picked up when they are used.	849	=item Backends that are transparently being picked up when they are used.
759		850
760	These will be used when they are currently loaded when the first watcher	851	These will be used when they are currently loaded when the first watcher
761	is created, in which case it is assumed that the application is using	852	is created, in which case it is assumed that the application is using
762	them. This means that AnyEvent will automatically pick the right backend	853	them. This means that AnyEvent will automatically pick the right backend
763	when the main program loads an event module before anything starts to	854	when the main program loads an event module before anything starts to
764	create watchers. Nothing special needs to be done by the main program.	855	create watchers. Nothing special needs to be done by the main program.
765		856
		857	AnyEvent::Impl::Event based on Event, very stable, few glitches.
766	AnyEvent::Impl::Glib based on Glib, slow but very stable.	858	AnyEvent::Impl::Glib based on Glib, slow but very stable.
767	AnyEvent::Impl::Tk based on Tk, very broken.	859	AnyEvent::Impl::Tk based on Tk, very broken.
768	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.	860	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
769	AnyEvent::Impl::POE based on POE, very slow, some limitations.	861	AnyEvent::Impl::POE based on POE, very slow, some limitations.
		862	AnyEvent::Impl::Irssi used when running within irssi.
770		863
771	=item Backends with special needs.	864	=item Backends with special needs.
772		865
773	Qt requires the Qt::Application to be instantiated first, but will	866	Qt requires the Qt::Application to be instantiated first, but will
774	otherwise be picked up automatically. As long as the main program	867	otherwise be picked up automatically. As long as the main program
…		…
848	event module detection too early, for example, L<AnyEvent::AIO> creates	941	event module detection too early, for example, L<AnyEvent::AIO> creates
849	and installs the global L<IO::AIO> watcher in a C<post_detect> block to	942	and installs the global L<IO::AIO> watcher in a C<post_detect> block to
850	avoid autodetecting the event module at load time.	943	avoid autodetecting the event module at load time.
851		944
852	If called in scalar or list context, then it creates and returns an object	945	If called in scalar or list context, then it creates and returns an object
853	that automatically removes the callback again when it is destroyed. See	946	that automatically removes the callback again when it is destroyed (or
		947	C<undef> when the hook was immediately executed). See L<AnyEvent::AIO> for
854	L<Coro::BDB> for a case where this is useful.	948	a case where this is useful.
		949
		950	Example: Create a watcher for the IO::AIO module and store it in
		951	C<$WATCHER>. Only do so after the event loop is initialised, though.
		952
		953	our WATCHER;
		954
		955	my $guard = AnyEvent::post_detect {
		956	$WATCHER = AnyEvent->io (fh => IO::AIO::poll_fileno, poll => 'r', cb => \&IO::AIO::poll_cb);
		957	};
		958
		959	# the ||= is important in case post_detect immediately runs the block,
		960	# as to not clobber the newly-created watcher. assigning both watcher and
		961	# post_detect guard to the same variable has the advantage of users being
		962	# able to just C<undef $WATCHER> if the watcher causes them grief.
		963
		964	$WATCHER ||= $guard;
855		965
856	=item @AnyEvent::post_detect	966	=item @AnyEvent::post_detect
857		967
858	If there are any code references in this array (you can C<push> to it	968	If there are any code references in this array (you can C<push> to it
859	before or after loading AnyEvent), then they will called directly after	969	before or after loading AnyEvent), then they will called directly after
…		…
862	You should check C<$AnyEvent::MODEL> before adding to this array, though:	972	You should check C<$AnyEvent::MODEL> before adding to this array, though:
863	if it is defined then the event loop has already been detected, and the	973	if it is defined then the event loop has already been detected, and the
864	array will be ignored.	974	array will be ignored.
865		975
866	Best use C<AnyEvent::post_detect { BLOCK }> when your application allows	976	Best use C<AnyEvent::post_detect { BLOCK }> when your application allows
867	it,as it takes care of these details.	977	it, as it takes care of these details.
868		978
869	This variable is mainly useful for modules that can do something useful	979	This variable is mainly useful for modules that can do something useful
870	when AnyEvent is used and thus want to know when it is initialised, but do	980	when AnyEvent is used and thus want to know when it is initialised, but do
871	not need to even load it by default. This array provides the means to hook	981	not need to even load it by default. This array provides the means to hook
872	into AnyEvent passively, without loading it.	982	into AnyEvent passively, without loading it.
		983
		984	Example: To load Coro::AnyEvent whenever Coro and AnyEvent are used
		985	together, you could put this into Coro (this is the actual code used by
		986	Coro to accomplish this):
		987
		988	if (defined $AnyEvent::MODEL) {
		989	# AnyEvent already initialised, so load Coro::AnyEvent
		990	require Coro::AnyEvent;
		991	} else {
		992	# AnyEvent not yet initialised, so make sure to load Coro::AnyEvent
		993	# as soon as it is
		994	push @AnyEvent::post_detect, sub { require Coro::AnyEvent };
		995	}
873		996
874	=back	997	=back
875		998
876	=head1 WHAT TO DO IN A MODULE	999	=head1 WHAT TO DO IN A MODULE
877		1000
…		…
959		1082
960	=item L<AnyEvent::DNS>	1083	=item L<AnyEvent::DNS>
961		1084
962	Provides rich asynchronous DNS resolver capabilities.	1085	Provides rich asynchronous DNS resolver capabilities.
963		1086
		1087	=item L<AnyEvent::HTTP>, L<AnyEvent::IRC>, L<AnyEvent::XMPP>, L<AnyEvent::GPSD>, L<AnyEvent::IGS>, L<AnyEvent::FCP>
		1088
		1089	Implement event-based interfaces to the protocols of the same name (for
		1090	the curious, IGS is the International Go Server and FCP is the Freenet
		1091	Client Protocol).
		1092
		1093	=item L<AnyEvent::Handle::UDP>
		1094
		1095	Here be danger!
		1096
		1097	As Pauli would put it, "Not only is it not right, it's not even wrong!" -
		1098	there are so many things wrong with AnyEvent::Handle::UDP, most notably
		1099	it's use of a stream-based API with a protocol that isn't streamable, that
		1100	the only way to improve it is to delete it.
		1101
		1102	It features data corruption (but typically only under load) and general
		1103	confusion. On top, the author is not only clueless about UDP but also
		1104	fact-resistant - some gems of his understanding: "connect doesn't work
		1105	with UDP", "UDP packets are not IP packets", "UDP only has datagrams, not
		1106	packets", "I don't need to implement proper error checking as UDP doesn't
		1107	support error checking" and so on - he doesn't even understand what's
		1108	wrong with his module when it is explained to him.
		1109
964	=item L<AnyEvent::HTTP>	1110	=item L<AnyEvent::DBI>
965		1111
966	A simple-to-use HTTP library that is capable of making a lot of concurrent	1112	Executes L<DBI> requests asynchronously in a proxy process for you,
967	HTTP requests.	1113	notifying you in an event-bnased way when the operation is finished.
		1114
		1115	=item L<AnyEvent::AIO>
		1116
		1117	Truly asynchronous (as opposed to non-blocking) I/O, should be in the
		1118	toolbox of every event programmer. AnyEvent::AIO transparently fuses
		1119	L<IO::AIO> and AnyEvent together, giving AnyEvent access to event-based
		1120	file I/O, and much more.
968		1121
969	=item L<AnyEvent::HTTPD>	1122	=item L<AnyEvent::HTTPD>
970		1123
971	Provides a simple web application server framework.	1124	A simple embedded webserver.
972		1125
973	=item L<AnyEvent::FastPing>	1126	=item L<AnyEvent::FastPing>
974		1127
975	The fastest ping in the west.	1128	The fastest ping in the west.
976		1129
977	=item L<AnyEvent::DBI>
978
979	Executes L<DBI> requests asynchronously in a proxy process.
980
981	=item L<AnyEvent::AIO>
982
983	Truly asynchronous I/O, should be in the toolbox of every event
984	programmer. AnyEvent::AIO transparently fuses L<IO::AIO> and AnyEvent
985	together.
986
987	=item L<AnyEvent::BDB>
988
989	Truly asynchronous Berkeley DB access. AnyEvent::BDB transparently fuses
990	L<BDB> and AnyEvent together.
991
992	=item L<AnyEvent::GPSD>
993
994	A non-blocking interface to gpsd, a daemon delivering GPS information.
995
996	=item L<AnyEvent::IRC>
997
998	AnyEvent based IRC client module family (replacing the older Net::IRC3).
999
1000	=item L<AnyEvent::XMPP>
1001
1002	AnyEvent based XMPP (Jabber protocol) module family (replacing the older
1003	Net::XMPP2>.
1004
1005	=item L<AnyEvent::IGS>
1006
1007	A non-blocking interface to the Internet Go Server protocol (used by
1008	L<App::IGS>).
1009
1010	=item L<Net::FCP>
1011
1012	AnyEvent-based implementation of the Freenet Client Protocol, birthplace
1013	of AnyEvent.
1014
1015	=item L<Event::ExecFlow>
1016
1017	High level API for event-based execution flow control.
1018
1019	=item L<Coro>	1130	=item L<Coro>
1020		1131
1021	Has special support for AnyEvent via L<Coro::AnyEvent>.	1132	Has special support for AnyEvent via L<Coro::AnyEvent>.
1022		1133
1023	=back	1134	=back
1024		1135
1025	=cut	1136	=cut
1026		1137
1027	package AnyEvent;	1138	package AnyEvent;
1028		1139
1029	no warnings;	1140	# basically a tuned-down version of common::sense
1030	use strict qw(vars subs);	1141	sub common_sense {
		1142	# from common:.sense 1.0
		1143	${^WARNING_BITS} = "\xfc\x3f\x33\x00\x0f\xf3\xcf\xc0\xf3\xfc\x33\x00";
		1144	# use strict vars subs - NO UTF-8, as Util.pm doesn't like this atm. (uts46data.pl)
		1145	$^H |= 0x00000600;
		1146	}
		1147
		1148	BEGIN { AnyEvent::common_sense }
1031		1149
1032	use Carp ();	1150	use Carp ();
1033		1151
1034	our $VERSION = 4.82;	1152	our $VERSION = '5.261';
1035	our $MODEL;	1153	our $MODEL;
1036		1154
1037	our $AUTOLOAD;	1155	our $AUTOLOAD;
1038	our @ISA;	1156	our @ISA;
1039		1157
1040	our @REGISTRY;	1158	our @REGISTRY;
1041		1159
1042	our $WIN32;	1160	our $VERBOSE;
1043		1161
1044	BEGIN {	1162	BEGIN {
1045	eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }";	1163	require "AnyEvent/constants.pl";
		1164
1046	eval "sub TAINT(){ " . (${^TAINT}*1) . " }";	1165	eval "sub TAINT (){" . (${^TAINT}*1) . "}";
1047		1166
1048	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}	1167	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}
1049	if ${^TAINT};	1168	if ${^TAINT};
1050	}
1051		1169
1052	our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1;	1170	$VERBOSE = $ENV{PERL_ANYEVENT_VERBOSE}*1;
		1171
		1172	}
		1173
		1174	our $MAX_SIGNAL_LATENCY = 10;
1053		1175
1054	our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred	1176	our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred
1055		1177
1056	{	1178	{
1057	my $idx;	1179	my $idx;
…		…
1059	for reverse split /\s*,\s*/,	1181	for reverse split /\s*,\s*/,
1060	$ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";	1182	$ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";
1061	}	1183	}
1062		1184
1063	my @models = (	1185	my @models = (
1064	[EV:: => AnyEvent::Impl::EV::],	1186	[EV:: => AnyEvent::Impl::EV:: , 1],
1065	[Event:: => AnyEvent::Impl::Event::],
1066	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::],	1187	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl:: , 1],
1067	# everything below here will not be autoprobed	1188	# everything below here will not (normally) be autoprobed
1068	# as the pureperl backend should work everywhere	1189	# as the pureperl backend should work everywhere
1069	# and is usually faster	1190	# and is usually faster
		1191	[Event:: => AnyEvent::Impl::Event::, 1],
1070	[Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers	1192	[Glib:: => AnyEvent::Impl::Glib:: , 1], # becomes extremely slow with many watchers
1071	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy	1193	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
		1194	[Irssi:: => AnyEvent::Impl::Irssi::], # Irssi has a bogus "Event" package
1072	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles	1195	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
1073	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program	1196	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program
1074	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza	1197	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
1075	[Wx:: => AnyEvent::Impl::POE::],	1198	[Wx:: => AnyEvent::Impl::POE::],
1076	[Prima:: => AnyEvent::Impl::POE::],	1199	[Prima:: => AnyEvent::Impl::POE::],
1077	# IO::Async is just too broken - we would need workarounds for its	1200	# IO::Async is just too broken - we would need workarounds for its
1078	# byzantine signal and broken child handling, among others.	1201	# byzantine signal and broken child handling, among others.
1079	# IO::Async is rather hard to detect, as it doesn't have any	1202	# IO::Async is rather hard to detect, as it doesn't have any
1080	# obvious default class.	1203	# obvious default class.
1081	# [IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program	1204	[IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program
1082	# [IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program	1205	[IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program
1083	# [IO::Async::Notifier:: => AnyEvent::Impl::IOAsync::], # requires special main program	1206	[IO::Async::Notifier:: => AnyEvent::Impl::IOAsync::], # requires special main program
		1207	[AnyEvent::Impl::IOAsync:: => AnyEvent::Impl::IOAsync::], # requires special main program
1084	);	1208	);
1085		1209
1086	our %method = map +($_ => 1),	1210	our %method = map +($_ => 1),
1087	qw(io timer time now now_update signal child idle condvar one_event DESTROY);	1211	qw(io timer time now now_update signal child idle condvar one_event DESTROY);
1088		1212
1089	our @post_detect;	1213	our @post_detect;
1090		1214
1091	sub post_detect(&) {	1215	sub post_detect(&) {
1092	my ($cb) = @_;	1216	my ($cb) = @_;
1093		1217
1094	if ($MODEL) {
1095	$cb->();
1096
1097	1
1098	} else {
1099	push @post_detect, $cb;	1218	push @post_detect, $cb;
1100		1219
1101	defined wantarray	1220	defined wantarray
1102	? bless \$cb, "AnyEvent::Util::postdetect"	1221	? bless \$cb, "AnyEvent::Util::postdetect"
1103	: ()	1222	: ()
1104	}
1105	}	1223	}
1106		1224
1107	sub AnyEvent::Util::postdetect::DESTROY {	1225	sub AnyEvent::Util::postdetect::DESTROY {
1108	@post_detect = grep $_ != ${$_[0]}, @post_detect;	1226	@post_detect = grep $_ != ${$_[0]}, @post_detect;
1109	}	1227	}
1110		1228
1111	sub detect() {	1229	sub detect() {
		1230	# free some memory
		1231	*detect = sub () { $MODEL };
		1232
		1233	local $!; # for good measure
		1234	local $SIG{__DIE__};
		1235
		1236	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {
		1237	my $model = "AnyEvent::Impl::$1";
		1238	if (eval "require $model") {
		1239	$MODEL = $model;
		1240	warn "AnyEvent: loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.\n" if $VERBOSE >= 2;
		1241	} else {
		1242	warn "AnyEvent: unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@" if $VERBOSE;
		1243	}
		1244	}
		1245
		1246	# check for already loaded models
1112	unless ($MODEL) {	1247	unless ($MODEL) {
1113	no strict 'refs';	1248	for (@REGISTRY, @models) {
1114	local $SIG{__DIE__};	1249	my ($package, $model) = @$_;
1115		1250	if (${"$package\::VERSION"} > 0) {
1116	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {
1117	my $model = "AnyEvent::Impl::$1";
1118	if (eval "require $model") {	1251	if (eval "require $model") {
1119	$MODEL = $model;	1252	$MODEL = $model;
1120	warn "AnyEvent: loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.\n" if $verbose > 1;	1253	warn "AnyEvent: autodetected model '$model', using it.\n" if $VERBOSE >= 2;
1121	} else {	1254	last;
1122	warn "AnyEvent: unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@" if $verbose;	1255	}
1123	}	1256	}
1124	}	1257	}
1125		1258
1126	# check for already loaded models
1127	unless ($MODEL) {	1259	unless ($MODEL) {
		1260	# try to autoload a model
1128	for (@REGISTRY, @models) {	1261	for (@REGISTRY, @models) {
1129	my ($package, $model) = @$_;	1262	my ($package, $model, $autoload) = @$_;
		1263	if (
		1264	$autoload
		1265	and eval "require $package"
1130	if (${"$package\::VERSION"} > 0) {	1266	and ${"$package\::VERSION"} > 0
1131	if (eval "require $model") {	1267	and eval "require $model"
		1268	) {
1132	$MODEL = $model;	1269	$MODEL = $model;
1133	warn "AnyEvent: autodetected model '$model', using it.\n" if $verbose > 1;	1270	warn "AnyEvent: autoloaded model '$model', using it.\n" if $VERBOSE >= 2;
1134	last;	1271	last;
1135	}
1136	}	1272	}
1137	}	1273	}
1138		1274
1139	unless ($MODEL) {
1140	# try to load a model
1141
1142	for (@REGISTRY, @models) {
1143	my ($package, $model) = @$_;
1144	if (eval "require $package"
1145	and ${"$package\::VERSION"} > 0
1146	and eval "require $model") {
1147	$MODEL = $model;
1148	warn "AnyEvent: autoprobed model '$model', using it.\n" if $verbose > 1;
1149	last;
1150	}
1151	}
1152
1153	$MODEL	1275	$MODEL
1154	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.\n";	1276	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.\n";
1155	}
1156	}	1277	}
1157
1158	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
1159
1160	unshift @ISA, $MODEL;
1161
1162	require AnyEvent::Strict if $ENV{PERL_ANYEVENT_STRICT};
1163
1164	(shift @post_detect)->() while @post_detect;
1165	}	1278	}
		1279
		1280	@models = (); # free probe data
		1281
		1282	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
		1283	unshift @ISA, $MODEL;
		1284
		1285	# now nuke some methods that are overriden by the backend.
		1286	# SUPER is not allowed.
		1287	for (qw(time signal child idle)) {
		1288	undef &{"AnyEvent::Base::$_"}
		1289	if defined &{"$MODEL\::$_"};
		1290	}
		1291
		1292	require AnyEvent::Strict if $ENV{PERL_ANYEVENT_STRICT};
		1293
		1294	(shift @post_detect)->() while @post_detect;
		1295
		1296	*post_detect = sub(&) {
		1297	shift->();
		1298
		1299	undef
		1300	};
1166		1301
1167	$MODEL	1302	$MODEL
1168	}	1303	}
1169		1304
1170	sub AUTOLOAD {	1305	sub AUTOLOAD {
1171	(my $func = $AUTOLOAD) =~ s/.*://;	1306	(my $func = $AUTOLOAD) =~ s/.*://;
1172		1307
1173	$method{$func}	1308	$method{$func}
1174	or Carp::croak "$func: not a valid method for AnyEvent objects";	1309	or Carp::croak "$func: not a valid AnyEvent class method";
1175		1310
1176	detect unless $MODEL;	1311	detect;
1177		1312
1178	my $class = shift;	1313	my $class = shift;
1179	$class->$func (@_);	1314	$class->$func (@_);
1180	}	1315	}
1181		1316
…		…
1184	# allow only one watcher per fd, so we dup it to get a different one).	1319	# allow only one watcher per fd, so we dup it to get a different one).
1185	sub _dupfh($$;$$) {	1320	sub _dupfh($$;$$) {
1186	my ($poll, $fh, $r, $w) = @_;	1321	my ($poll, $fh, $r, $w) = @_;
1187		1322
1188	# cygwin requires the fh mode to be matching, unix doesn't	1323	# cygwin requires the fh mode to be matching, unix doesn't
1189	my ($rw, $mode) = $poll eq "r" ? ($r, "<") : ($w, ">");	1324	my ($rw, $mode) = $poll eq "r" ? ($r, "<&") : ($w, ">&");
1190		1325
1191	open my $fh2, "$mode&", $fh	1326	open my $fh2, $mode, $fh
1192	or die "AnyEvent->io: cannot dup() filehandle in mode '$poll': $!,";	1327	or die "AnyEvent->io: cannot dup() filehandle in mode '$poll': $!,";
1193		1328
1194	# we assume CLOEXEC is already set by perl in all important cases	1329	# we assume CLOEXEC is already set by perl in all important cases
1195		1330
1196	($fh2, $rw)	1331	($fh2, $rw)
1197	}	1332	}
1198		1333
		1334	=head1 SIMPLIFIED AE API
		1335
		1336	Starting with version 5.0, AnyEvent officially supports a second, much
		1337	simpler, API that is designed to reduce the calling, typing and memory
		1338	overhead by using function call syntax and a fixed number of parameters.
		1339
		1340	See the L<AE> manpage for details.
		1341
		1342	=cut
		1343
		1344	package AE;
		1345
		1346	our $VERSION = $AnyEvent::VERSION;
		1347
		1348	# fall back to the main API by default - backends and AnyEvent::Base
		1349	# implementations can overwrite these.
		1350
		1351	sub io($$$) {
		1352	AnyEvent->io (fh => $_[0], poll => $_[1] ? "w" : "r", cb => $_[2])
		1353	}
		1354
		1355	sub timer($$$) {
		1356	AnyEvent->timer (after => $_[0], interval => $_[1], cb => $_[2])
		1357	}
		1358
		1359	sub signal($$) {
		1360	AnyEvent->signal (signal => $_[0], cb => $_[1])
		1361	}
		1362
		1363	sub child($$) {
		1364	AnyEvent->child (pid => $_[0], cb => $_[1])
		1365	}
		1366
		1367	sub idle($) {
		1368	AnyEvent->idle (cb => $_[0])
		1369	}
		1370
		1371	sub cv(;&) {
		1372	AnyEvent->condvar (@_ ? (cb => $_[0]) : ())
		1373	}
		1374
		1375	sub now() {
		1376	AnyEvent->now
		1377	}
		1378
		1379	sub now_update() {
		1380	AnyEvent->now_update
		1381	}
		1382
		1383	sub time() {
		1384	AnyEvent->time
		1385	}
		1386
1199	package AnyEvent::Base;	1387	package AnyEvent::Base;
1200		1388
1201	# default implementations for many methods	1389	# default implementations for many methods
1202		1390
1203	BEGIN {	1391	sub time {
		1392	eval q{ # poor man's autoloading {}
		1393	# probe for availability of Time::HiRes
1204	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {	1394	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {
		1395	warn "AnyEvent: using Time::HiRes for sub-second timing accuracy.\n" if $VERBOSE >= 8;
1205	*_time = \&Time::HiRes::time;	1396	*AE::time = \&Time::HiRes::time;
1206	# if (eval "use POSIX (); (POSIX::times())...	1397	# if (eval "use POSIX (); (POSIX::times())...
1207	} else {	1398	} else {
		1399	warn "AnyEvent: using built-in time(), WARNING, no sub-second resolution!\n" if $VERBOSE;
1208	*_time = sub { time }; # epic fail	1400	*AE::time = sub (){ time }; # epic fail
		1401	}
		1402
		1403	*time = sub { AE::time }; # different prototypes
		1404	};
		1405	die if $@;
		1406
		1407	&time
		1408	}
		1409
		1410	*now = \&time;
		1411
		1412	sub now_update { }
		1413
		1414	# default implementation for ->condvar
		1415
		1416	sub condvar {
		1417	eval q{ # poor man's autoloading {}
		1418	*condvar = sub {
		1419	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"
		1420	};
		1421
		1422	*AE::cv = sub (;&) {
		1423	bless { @_ ? (_ae_cb => shift) : () }, "AnyEvent::CondVar"
		1424	};
		1425	};
		1426	die if $@;
		1427
		1428	&condvar
		1429	}
		1430
		1431	# default implementation for ->signal
		1432
		1433	our $HAVE_ASYNC_INTERRUPT;
		1434
		1435	sub _have_async_interrupt() {
		1436	$HAVE_ASYNC_INTERRUPT = 1*(!$ENV{PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT}
		1437	&& eval "use Async::Interrupt 1.02 (); 1")
		1438	unless defined $HAVE_ASYNC_INTERRUPT;
		1439
		1440	$HAVE_ASYNC_INTERRUPT
		1441	}
		1442
		1443	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);
		1444	our (%SIG_ASY, %SIG_ASY_W);
		1445	our ($SIG_COUNT, $SIG_TW);
		1446
		1447	# install a dummy wakeup watcher to reduce signal catching latency
		1448	# used by Impls
		1449	sub _sig_add() {
		1450	unless ($SIG_COUNT++) {
		1451	# try to align timer on a full-second boundary, if possible
		1452	my $NOW = AE::now;
		1453
		1454	$SIG_TW = AE::timer
		1455	$MAX_SIGNAL_LATENCY - ($NOW - int $NOW),
		1456	$MAX_SIGNAL_LATENCY,
		1457	sub { } # just for the PERL_ASYNC_CHECK
		1458	;
1209	}	1459	}
1210	}	1460	}
1211		1461
1212	sub time { _time }	1462	sub _sig_del {
1213	sub now { _time }	1463	undef $SIG_TW
1214	sub now_update { }	1464	unless --$SIG_COUNT;
1215
1216	# default implementation for ->condvar
1217
1218	sub condvar {
1219	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"
1220	}	1465	}
1221		1466
1222	# default implementation for ->signal	1467	our $_sig_name_init; $_sig_name_init = sub {
		1468	eval q{ # poor man's autoloading {}
		1469	undef $_sig_name_init;
1223		1470
1224	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);	1471	if (_have_async_interrupt) {
		1472	*sig2num = \&Async::Interrupt::sig2num;
		1473	*sig2name = \&Async::Interrupt::sig2name;
		1474	} else {
		1475	require Config;
1225		1476
1226	sub _signal_exec {	1477	my %signame2num;
1227	sysread $SIGPIPE_R, my $dummy, 4;	1478	@signame2num{ split ' ', $Config::Config{sig_name} }
		1479	= split ' ', $Config::Config{sig_num};
1228		1480
1229	while (%SIG_EV) {	1481	my @signum2name;
1230	for (keys %SIG_EV) {	1482	@signum2name[values %signame2num] = keys %signame2num;
1231	delete $SIG_EV{$_};	1483
1232	$_->() for values %{ $SIG_CB{$_} || {} };	1484	*sig2num = sub($) {
		1485	$_[0] > 0 ? shift : $signame2num{+shift}
		1486	};
		1487	*sig2name = sub ($) {
		1488	$_[0] > 0 ? $signum2name[+shift] : shift
		1489	};
1233	}	1490	}
1234	}	1491	};
1235	}	1492	die if $@;
		1493	};
		1494
		1495	sub sig2num ($) { &$_sig_name_init; &sig2num }
		1496	sub sig2name($) { &$_sig_name_init; &sig2name }
1236		1497
1237	sub signal {	1498	sub signal {
1238	my (undef, %arg) = @_;	1499	eval q{ # poor man's autoloading {}
		1500	# probe for availability of Async::Interrupt
		1501	if (_have_async_interrupt) {
		1502	warn "AnyEvent: using Async::Interrupt for race-free signal handling.\n" if $VERBOSE >= 8;
1239		1503
1240	unless ($SIGPIPE_R) {	1504	$SIGPIPE_R = new Async::Interrupt::EventPipe;
1241	require Fcntl;	1505	$SIG_IO = AE::io $SIGPIPE_R->fileno, 0, \&_signal_exec;
1242		1506
1243	if (AnyEvent::WIN32) {
1244	require AnyEvent::Util;
1245
1246	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
1247	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R) if $SIGPIPE_R;
1248	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W) if $SIGPIPE_W; # just in case
1249	} else {	1507	} else {
		1508	warn "AnyEvent: using emulated perl signal handling with latency timer.\n" if $VERBOSE >= 8;
		1509
		1510	if (AnyEvent::WIN32) {
		1511	require AnyEvent::Util;
		1512
		1513	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
		1514	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R, 1) if $SIGPIPE_R;
		1515	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W, 1) if $SIGPIPE_W; # just in case
		1516	} else {
1250	pipe $SIGPIPE_R, $SIGPIPE_W;	1517	pipe $SIGPIPE_R, $SIGPIPE_W;
1251	fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R;	1518	fcntl $SIGPIPE_R, AnyEvent::F_SETFL, AnyEvent::O_NONBLOCK if $SIGPIPE_R;
1252	fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case	1519	fcntl $SIGPIPE_W, AnyEvent::F_SETFL, AnyEvent::O_NONBLOCK if $SIGPIPE_W; # just in case
1253		1520
1254	# not strictly required, as $^F is normally 2, but let's make sure...	1521	# not strictly required, as $^F is normally 2, but let's make sure...
1255	fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;	1522	fcntl $SIGPIPE_R, AnyEvent::F_SETFD, AnyEvent::FD_CLOEXEC;
1256	fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;	1523	fcntl $SIGPIPE_W, AnyEvent::F_SETFD, AnyEvent::FD_CLOEXEC;
		1524	}
		1525
		1526	$SIGPIPE_R
		1527	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";
		1528
		1529	$SIG_IO = AE::io $SIGPIPE_R, 0, \&_signal_exec;
1257	}	1530	}
1258		1531
1259	$SIGPIPE_R	1532	*signal = $HAVE_ASYNC_INTERRUPT
1260	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";	1533	? sub {
		1534	my (undef, %arg) = @_;
1261		1535
1262	$SIG_IO = AnyEvent->io (fh => $SIGPIPE_R, poll => "r", cb => \&_signal_exec);	1536	# async::interrupt
1263	}
1264
1265	my $signal = uc $arg{signal}	1537	my $signal = sig2num $arg{signal};
1266	or Carp::croak "required option 'signal' is missing";
1267
1268	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};	1538	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
		1539
		1540	$SIG_ASY{$signal} ||= new Async::Interrupt
		1541	cb => sub { undef $SIG_EV{$signal} },
		1542	signal => $signal,
		1543	pipe => [$SIGPIPE_R->filenos],
		1544	pipe_autodrain => 0,
		1545	;
		1546
		1547	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
		1548	}
		1549	: sub {
		1550	my (undef, %arg) = @_;
		1551
		1552	# pure perl
		1553	my $signal = sig2name $arg{signal};
		1554	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
		1555
1269	$SIG{$signal} ||= sub {	1556	$SIG{$signal} ||= sub {
1270	local $!;	1557	local $!;
1271	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;	1558	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;
1272	undef $SIG_EV{$signal};	1559	undef $SIG_EV{$signal};
		1560	};
		1561
		1562	# can't do signal processing without introducing races in pure perl,
		1563	# so limit the signal latency.
		1564	_sig_add;
		1565
		1566	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
		1567	}
		1568	;
		1569
		1570	*AnyEvent::Base::signal::DESTROY = sub {
		1571	my ($signal, $cb) = @{$_[0]};
		1572
		1573	_sig_del;
		1574
		1575	delete $SIG_CB{$signal}{$cb};
		1576
		1577	$HAVE_ASYNC_INTERRUPT
		1578	? delete $SIG_ASY{$signal}
		1579	: # delete doesn't work with older perls - they then
		1580	# print weird messages, or just unconditionally exit
		1581	# instead of getting the default action.
		1582	undef $SIG{$signal}
		1583	unless keys %{ $SIG_CB{$signal} };
		1584	};
		1585
		1586	*_signal_exec = sub {
		1587	$HAVE_ASYNC_INTERRUPT
		1588	? $SIGPIPE_R->drain
		1589	: sysread $SIGPIPE_R, (my $dummy), 9;
		1590
		1591	while (%SIG_EV) {
		1592	for (keys %SIG_EV) {
		1593	delete $SIG_EV{$_};
		1594	$_->() for values %{ $SIG_CB{$_} || {} };
		1595	}
		1596	}
		1597	};
1273	};	1598	};
		1599	die if $@;
1274		1600
1275	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"	1601	&signal
1276	}
1277
1278	sub AnyEvent::Base::signal::DESTROY {
1279	my ($signal, $cb) = @{$_[0]};
1280
1281	delete $SIG_CB{$signal}{$cb};
1282
1283	# delete doesn't work with older perls - they then
1284	# print weird messages, or just unconditionally exit
1285	# instead of getting the default action.
1286	undef $SIG{$signal} unless keys %{ $SIG_CB{$signal} };
1287	}	1602	}
1288		1603
1289	# default implementation for ->child	1604	# default implementation for ->child
1290		1605
1291	our %PID_CB;	1606	our %PID_CB;
1292	our $CHLD_W;	1607	our $CHLD_W;
1293	our $CHLD_DELAY_W;	1608	our $CHLD_DELAY_W;
1294	our $WNOHANG;	1609	our $WNOHANG;
1295		1610
1296	sub _sigchld {	1611	# used by many Impl's
1297	while (0 < (my $pid = waitpid -1, $WNOHANG)) {	1612	sub _emit_childstatus($$) {
		1613	my (undef, $rpid, $rstatus) = @_;
		1614
		1615	$_->($rpid, $rstatus)
1298	$_->($pid, $?) for (values %{ $PID_CB{$pid} || {} }),	1616	for values %{ $PID_CB{$rpid} || {} },
1299	(values %{ $PID_CB{0} || {} });	1617	values %{ $PID_CB{0} || {} };
1300	}
1301	}	1618	}
1302		1619
1303	sub child {	1620	sub child {
		1621	eval q{ # poor man's autoloading {}
		1622	*_sigchld = sub {
		1623	my $pid;
		1624
		1625	AnyEvent->_emit_childstatus ($pid, $?)
		1626	while ($pid = waitpid -1, $WNOHANG) > 0;
		1627	};
		1628
		1629	*child = sub {
1304	my (undef, %arg) = @_;	1630	my (undef, %arg) = @_;
1305		1631
1306	defined (my $pid = $arg{pid} + 0)	1632	defined (my $pid = $arg{pid} + 0)
1307	or Carp::croak "required option 'pid' is missing";	1633	or Carp::croak "required option 'pid' is missing";
1308		1634
1309	$PID_CB{$pid}{$arg{cb}} = $arg{cb};	1635	$PID_CB{$pid}{$arg{cb}} = $arg{cb};
1310		1636
		1637	# WNOHANG is almost cetrainly 1 everywhere
		1638	$WNOHANG ||= $^O =~ /^(?:openbsd|netbsd|linux|freebsd|cygwin|MSWin32)$/
		1639	? 1
1311	$WNOHANG ||= eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1;	1640	: eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1;
1312		1641
1313	unless ($CHLD_W) {	1642	unless ($CHLD_W) {
1314	$CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld);	1643	$CHLD_W = AE::signal CHLD => \&_sigchld;
1315	# child could be a zombie already, so make at least one round	1644	# child could be a zombie already, so make at least one round
1316	&_sigchld;	1645	&_sigchld;
1317	}	1646	}
1318		1647
1319	bless [$pid, $arg{cb}], "AnyEvent::Base::child"	1648	bless [$pid, $arg{cb}], "AnyEvent::Base::child"
1320	}	1649	};
1321		1650
1322	sub AnyEvent::Base::child::DESTROY {	1651	*AnyEvent::Base::child::DESTROY = sub {
1323	my ($pid, $cb) = @{$_[0]};	1652	my ($pid, $cb) = @{$_[0]};
1324		1653
1325	delete $PID_CB{$pid}{$cb};	1654	delete $PID_CB{$pid}{$cb};
1326	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };	1655	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };
1327		1656
1328	undef $CHLD_W unless keys %PID_CB;	1657	undef $CHLD_W unless keys %PID_CB;
		1658	};
		1659	};
		1660	die if $@;
		1661
		1662	&child
1329	}	1663	}
1330		1664
1331	# idle emulation is done by simply using a timer, regardless	1665	# idle emulation is done by simply using a timer, regardless
1332	# of whether the process is idle or not, and not letting	1666	# of whether the process is idle or not, and not letting
1333	# the callback use more than 50% of the time.	1667	# the callback use more than 50% of the time.
1334	sub idle {	1668	sub idle {
		1669	eval q{ # poor man's autoloading {}
		1670	*idle = sub {
1335	my (undef, %arg) = @_;	1671	my (undef, %arg) = @_;
1336		1672
1337	my ($cb, $w, $rcb) = $arg{cb};	1673	my ($cb, $w, $rcb) = $arg{cb};
1338		1674
1339	$rcb = sub {	1675	$rcb = sub {
1340	if ($cb) {	1676	if ($cb) {
1341	$w = _time;	1677	$w = _time;
1342	&$cb;	1678	&$cb;
1343	$w = _time - $w;	1679	$w = _time - $w;
1344		1680
1345	# never use more then 50% of the time for the idle watcher,	1681	# never use more then 50% of the time for the idle watcher,
1346	# within some limits	1682	# within some limits
1347	$w = 0.0001 if $w < 0.0001;	1683	$w = 0.0001 if $w < 0.0001;
1348	$w = 5 if $w > 5;	1684	$w = 5 if $w > 5;
1349		1685
1350	$w = AnyEvent->timer (after => $w, cb => $rcb);	1686	$w = AE::timer $w, 0, $rcb;
1351	} else {	1687	} else {
1352	# clean up...	1688	# clean up...
1353	undef $w;	1689	undef $w;
1354	undef $rcb;	1690	undef $rcb;
		1691	}
		1692	};
		1693
		1694	$w = AE::timer 0.05, 0, $rcb;
		1695
		1696	bless \\$cb, "AnyEvent::Base::idle"
1355	}	1697	};
		1698
		1699	*AnyEvent::Base::idle::DESTROY = sub {
		1700	undef $${$_[0]};
		1701	};
1356	};	1702	};
		1703	die if $@;
1357		1704
1358	$w = AnyEvent->timer (after => 0.05, cb => $rcb);	1705	&idle
1359
1360	bless \\$cb, "AnyEvent::Base::idle"
1361	}
1362
1363	sub AnyEvent::Base::idle::DESTROY {
1364	undef $${$_[0]};
1365	}	1706	}
1366		1707
1367	package AnyEvent::CondVar;	1708	package AnyEvent::CondVar;
1368		1709
1369	our @ISA = AnyEvent::CondVar::Base::;	1710	our @ISA = AnyEvent::CondVar::Base::;
1370		1711
1371	package AnyEvent::CondVar::Base;	1712	package AnyEvent::CondVar::Base;
1372		1713
1373	use overload	1714	#use overload
1374	'&{}' => sub { my $self = shift; sub { $self->send (@_) } },	1715	# '&{}' => sub { my $self = shift; sub { $self->send (@_) } },
1375	fallback => 1;	1716	# fallback => 1;
		1717
		1718	# save 300+ kilobytes by dirtily hardcoding overloading
		1719	${"AnyEvent::CondVar::Base::OVERLOAD"}{dummy}++; # Register with magic by touching.
		1720	*{'AnyEvent::CondVar::Base::()'} = sub { }; # "Make it findable via fetchmethod."
		1721	*{'AnyEvent::CondVar::Base::(&{}'} = sub { my $self = shift; sub { $self->send (@_) } }; # &{}
		1722	${'AnyEvent::CondVar::Base::()'} = 1; # fallback
1376		1723
1377	our $WAITING;	1724	our $WAITING;
1378		1725
1379	sub _send {	1726	sub _send {
1380	# nop	1727	# nop
…		…
1411	Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak};	1758	Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak};
1412	wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0]	1759	wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0]
1413	}	1760	}
1414		1761
1415	sub cb {	1762	sub cb {
1416	$_[0]{_ae_cb} = $_[1] if @_ > 1;	1763	my $cv = shift;
		1764
		1765	@_
		1766	and $cv->{_ae_cb} = shift
		1767	and $cv->{_ae_sent}
		1768	and (delete $cv->{_ae_cb})->($cv);
		1769
1417	$_[0]{_ae_cb}	1770	$cv->{_ae_cb}
1418	}	1771	}
1419		1772
1420	sub begin {	1773	sub begin {
1421	++$_[0]{_ae_counter};	1774	++$_[0]{_ae_counter};
1422	$_[0]{_ae_end_cb} = $_[1] if @_ > 1;	1775	$_[0]{_ae_end_cb} = $_[1] if @_ > 1;
…		…
1471	C<PERL_ANYEVENT_MODEL>.	1824	C<PERL_ANYEVENT_MODEL>.
1472		1825
1473	When set to C<2> or higher, cause AnyEvent to report to STDERR which event	1826	When set to C<2> or higher, cause AnyEvent to report to STDERR which event
1474	model it chooses.	1827	model it chooses.
1475		1828
		1829	When set to C<8> or higher, then AnyEvent will report extra information on
		1830	which optional modules it loads and how it implements certain features.
		1831
1476	=item C<PERL_ANYEVENT_STRICT>	1832	=item C<PERL_ANYEVENT_STRICT>
1477		1833
1478	AnyEvent does not do much argument checking by default, as thorough	1834	AnyEvent does not do much argument checking by default, as thorough
1479	argument checking is very costly. Setting this variable to a true value	1835	argument checking is very costly. Setting this variable to a true value
1480	will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly	1836	will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly
1481	check the arguments passed to most method calls. If it finds any problems,	1837	check the arguments passed to most method calls. If it finds any problems,
1482	it will croak.	1838	it will croak.
1483		1839
1484	In other words, enables "strict" mode.	1840	In other words, enables "strict" mode.
1485		1841
1486	Unlike C<use strict>, it is definitely recommended to keep it off in	1842	Unlike C<use strict> (or it's modern cousin, C<< use L<common::sense>
1487	production. Keeping C<PERL_ANYEVENT_STRICT=1> in your environment while	1843	>>, it is definitely recommended to keep it off in production. Keeping
1488	developing programs can be very useful, however.	1844	C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs
		1845	can be very useful, however.
1489		1846
1490	=item C<PERL_ANYEVENT_MODEL>	1847	=item C<PERL_ANYEVENT_MODEL>
1491		1848
1492	This can be used to specify the event model to be used by AnyEvent, before	1849	This can be used to specify the event model to be used by AnyEvent, before
1493	auto detection and -probing kicks in. It must be a string consisting	1850	auto detection and -probing kicks in. It must be a string consisting
…		…
1555		1912
1556	When neither C<ca_file> nor C<ca_path> was specified during	1913	When neither C<ca_file> nor C<ca_path> was specified during
1557	L<AnyEvent::TLS> context creation, and either of these environment	1914	L<AnyEvent::TLS> context creation, and either of these environment
1558	variables exist, they will be used to specify CA certificate locations	1915	variables exist, they will be used to specify CA certificate locations
1559	instead of a system-dependent default.	1916	instead of a system-dependent default.
		1917
		1918	=item C<PERL_ANYEVENT_AVOID_GUARD> and C<PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT>
		1919
		1920	When these are set to C<1>, then the respective modules are not
		1921	loaded. Mostly good for testing AnyEvent itself.
1560		1922
1561	=back	1923	=back
1562		1924
1563	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE	1925	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE
1564		1926
…		…
1622	warn "read: $input\n"; # output what has been read	1984	warn "read: $input\n"; # output what has been read
1623	$cv->send if $input =~ /^q/i; # quit program if /^q/i	1985	$cv->send if $input =~ /^q/i; # quit program if /^q/i
1624	},	1986	},
1625	);	1987	);
1626		1988
1627	my $time_watcher; # can only be used once
1628
1629	sub new_timer {
1630	$timer = AnyEvent->timer (after => 1, cb => sub {	1989	my $time_watcher = AnyEvent->timer (after => 1, interval => 1, cb => sub {
1631	warn "timeout\n"; # print 'timeout' about every second	1990	warn "timeout\n"; # print 'timeout' at most every second
1632	&new_timer; # and restart the time
1633	});	1991	});
1634	}
1635
1636	new_timer; # create first timer
1637		1992
1638	$cv->recv; # wait until user enters /^q/i	1993	$cv->recv; # wait until user enters /^q/i
1639		1994
1640	=head1 REAL-WORLD EXAMPLE	1995	=head1 REAL-WORLD EXAMPLE
1641		1996
…		…
1714		2069
1715	The actual code goes further and collects all errors (C<die>s, exceptions)	2070	The actual code goes further and collects all errors (C<die>s, exceptions)
1716	that occurred during request processing. The C<result> method detects	2071	that occurred during request processing. The C<result> method detects
1717	whether an exception as thrown (it is stored inside the $txn object)	2072	whether an exception as thrown (it is stored inside the $txn object)
1718	and just throws the exception, which means connection errors and other	2073	and just throws the exception, which means connection errors and other
1719	problems get reported tot he code that tries to use the result, not in a	2074	problems get reported to the code that tries to use the result, not in a
1720	random callback.	2075	random callback.
1721		2076
1722	All of this enables the following usage styles:	2077	All of this enables the following usage styles:
1723		2078
1724	1. Blocking:	2079	1. Blocking:
…		…
1772	through AnyEvent. The benchmark creates a lot of timers (with a zero	2127	through AnyEvent. The benchmark creates a lot of timers (with a zero
1773	timeout) and I/O watchers (watching STDOUT, a pty, to become writable,	2128	timeout) and I/O watchers (watching STDOUT, a pty, to become writable,
1774	which it is), lets them fire exactly once and destroys them again.	2129	which it is), lets them fire exactly once and destroys them again.
1775		2130
1776	Source code for this benchmark is found as F<eg/bench> in the AnyEvent	2131	Source code for this benchmark is found as F<eg/bench> in the AnyEvent
1777	distribution.	2132	distribution. It uses the L<AE> interface, which makes a real difference
		2133	for the EV and Perl backends only.
1778		2134
1779	=head3 Explanation of the columns	2135	=head3 Explanation of the columns
1780		2136
1781	I<watcher> is the number of event watchers created/destroyed. Since	2137	I<watcher> is the number of event watchers created/destroyed. Since
1782	different event models feature vastly different performances, each event	2138	different event models feature vastly different performances, each event
…		…
1803	watcher.	2159	watcher.
1804		2160
1805	=head3 Results	2161	=head3 Results
1806		2162
1807	name watchers bytes create invoke destroy comment	2163	name watchers bytes create invoke destroy comment
1808	EV/EV 400000 224 0.47 0.35 0.27 EV native interface	2164	EV/EV 100000 223 0.47 0.43 0.27 EV native interface
1809	EV/Any 100000 224 2.88 0.34 0.27 EV + AnyEvent watchers	2165	EV/Any 100000 223 0.48 0.42 0.26 EV + AnyEvent watchers
1810	CoroEV/Any 100000 224 2.85 0.35 0.28 coroutines + Coro::Signal	2166	Coro::EV/Any 100000 223 0.47 0.42 0.26 coroutines + Coro::Signal
1811	Perl/Any 100000 452 4.13 0.73 0.95 pure perl implementation	2167	Perl/Any 100000 431 2.70 0.74 0.92 pure perl implementation
1812	Event/Event 16000 517 32.20 31.80 0.81 Event native interface	2168	Event/Event 16000 516 31.16 31.84 0.82 Event native interface
1813	Event/Any 16000 590 35.85 31.55 1.06 Event + AnyEvent watchers	2169	Event/Any 16000 1203 42.61 34.79 1.80 Event + AnyEvent watchers
1814	IOAsync/Any 16000 989 38.10 32.77 11.13 via IO::Async::Loop::IO_Poll	2170	IOAsync/Any 16000 1911 41.92 27.45 16.81 via IO::Async::Loop::IO_Poll
1815	IOAsync/Any 16000 990 37.59 29.50 10.61 via IO::Async::Loop::Epoll	2171	IOAsync/Any 16000 1726 40.69 26.37 15.25 via IO::Async::Loop::Epoll
1816	Glib/Any 16000 1357 102.33 12.31 51.00 quadratic behaviour	2172	Glib/Any 16000 1118 89.00 12.57 51.17 quadratic behaviour
1817	Tk/Any 2000 1860 27.20 66.31 14.00 SEGV with >> 2000 watchers	2173	Tk/Any 2000 1346 20.96 10.75 8.00 SEGV with >> 2000 watchers
1818	POE/Event 2000 6328 109.99 751.67 14.02 via POE::Loop::Event	2174	POE/Any 2000 6951 108.97 795.32 14.24 via POE::Loop::Event
1819	POE/Select 2000 6027 94.54 809.13 579.80 via POE::Loop::Select	2175	POE/Any 2000 6648 94.79 774.40 575.51 via POE::Loop::Select
1820		2176
1821	=head3 Discussion	2177	=head3 Discussion
1822		2178
1823	The benchmark does I<not> measure scalability of the event loop very	2179	The benchmark does I<not> measure scalability of the event loop very
1824	well. For example, a select-based event loop (such as the pure perl one)	2180	well. For example, a select-based event loop (such as the pure perl one)
…		…
1836	benchmark machine, handling an event takes roughly 1600 CPU cycles with	2192	benchmark machine, handling an event takes roughly 1600 CPU cycles with
1837	EV, 3100 CPU cycles with AnyEvent's pure perl loop and almost 3000000 CPU	2193	EV, 3100 CPU cycles with AnyEvent's pure perl loop and almost 3000000 CPU
1838	cycles with POE.	2194	cycles with POE.
1839		2195
1840	C<EV> is the sole leader regarding speed and memory use, which are both	2196	C<EV> is the sole leader regarding speed and memory use, which are both
1841	maximal/minimal, respectively. Even when going through AnyEvent, it uses	2197	maximal/minimal, respectively. When using the L<AE> API there is zero
		2198	overhead (when going through the AnyEvent API create is about 5-6 times
		2199	slower, with other times being equal, so still uses far less memory than
1842	far less memory than any other event loop and is still faster than Event	2200	any other event loop and is still faster than Event natively).
1843	natively.
1844		2201
1845	The pure perl implementation is hit in a few sweet spots (both the	2202	The pure perl implementation is hit in a few sweet spots (both the
1846	constant timeout and the use of a single fd hit optimisations in the perl	2203	constant timeout and the use of a single fd hit optimisations in the perl
1847	interpreter and the backend itself). Nevertheless this shows that it	2204	interpreter and the backend itself). Nevertheless this shows that it
1848	adds very little overhead in itself. Like any select-based backend its	2205	adds very little overhead in itself. Like any select-based backend its
…		…
1922	In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100	2279	In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100
1923	(1%) are active. This mirrors the activity of large servers with many	2280	(1%) are active. This mirrors the activity of large servers with many
1924	connections, most of which are idle at any one point in time.	2281	connections, most of which are idle at any one point in time.
1925		2282
1926	Source code for this benchmark is found as F<eg/bench2> in the AnyEvent	2283	Source code for this benchmark is found as F<eg/bench2> in the AnyEvent
1927	distribution.	2284	distribution. It uses the L<AE> interface, which makes a real difference
		2285	for the EV and Perl backends only.
1928		2286
1929	=head3 Explanation of the columns	2287	=head3 Explanation of the columns
1930		2288
1931	I<sockets> is the number of sockets, and twice the number of "servers" (as	2289	I<sockets> is the number of sockets, and twice the number of "servers" (as
1932	each server has a read and write socket end).	2290	each server has a read and write socket end).
…		…
1940	a new one that moves the timeout into the future.	2298	a new one that moves the timeout into the future.
1941		2299
1942	=head3 Results	2300	=head3 Results
1943		2301
1944	name sockets create request	2302	name sockets create request
1945	EV 20000 69.01 11.16	2303	EV 20000 62.66 7.99
1946	Perl 20000 73.32 35.87	2304	Perl 20000 68.32 32.64
1947	IOAsync 20000 157.00 98.14 epoll	2305	IOAsync 20000 174.06 101.15 epoll
1948	IOAsync 20000 159.31 616.06 poll	2306	IOAsync 20000 174.67 610.84 poll
1949	Event 20000 212.62 257.32	2307	Event 20000 202.69 242.91
1950	Glib 20000 651.16 1896.30	2308	Glib 20000 557.01 1689.52
1951	POE 20000 349.67 12317.24 uses POE::Loop::Event	2309	POE 20000 341.54 12086.32 uses POE::Loop::Event
1952		2310
1953	=head3 Discussion	2311	=head3 Discussion
1954		2312
1955	This benchmark I<does> measure scalability and overall performance of the	2313	This benchmark I<does> measure scalability and overall performance of the
1956	particular event loop.	2314	particular event loop.
…		…
2082	As you can see, the AnyEvent + EV combination even beats the	2440	As you can see, the AnyEvent + EV combination even beats the
2083	hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl	2441	hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl
2084	backend easily beats IO::Lambda and POE.	2442	backend easily beats IO::Lambda and POE.
2085		2443
2086	And even the 100% non-blocking version written using the high-level (and	2444	And even the 100% non-blocking version written using the high-level (and
2087	slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda by a	2445	slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda
2088	large margin, even though it does all of DNS, tcp-connect and socket I/O	2446	higher level ("unoptimised") abstractions by a large margin, even though
2089	in a non-blocking way.	2447	it does all of DNS, tcp-connect and socket I/O in a non-blocking way.
2090		2448
2091	The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and	2449	The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and
2092	F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are	2450	F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are
2093	part of the IO::lambda distribution and were used without any changes.	2451	part of the IO::Lambda distribution and were used without any changes.
2094		2452
2095		2453
2096	=head1 SIGNALS	2454	=head1 SIGNALS
2097		2455
2098	AnyEvent currently installs handlers for these signals:	2456	AnyEvent currently installs handlers for these signals:
…		…
2132	if $SIG{CHLD} eq 'IGNORE';	2490	if $SIG{CHLD} eq 'IGNORE';
2133		2491
2134	$SIG{PIPE} = sub { }	2492	$SIG{PIPE} = sub { }
2135	unless defined $SIG{PIPE};	2493	unless defined $SIG{PIPE};
2136		2494
		2495	=head1 RECOMMENDED/OPTIONAL MODULES
		2496
		2497	One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and
		2498	it's built-in modules) are required to use it.
		2499
		2500	That does not mean that AnyEvent won't take advantage of some additional
		2501	modules if they are installed.
		2502
		2503	This section explains which additional modules will be used, and how they
		2504	affect AnyEvent's operation.
		2505
		2506	=over 4
		2507
		2508	=item L<Async::Interrupt>
		2509
		2510	This slightly arcane module is used to implement fast signal handling: To
		2511	my knowledge, there is no way to do completely race-free and quick
		2512	signal handling in pure perl. To ensure that signals still get
		2513	delivered, AnyEvent will start an interval timer to wake up perl (and
		2514	catch the signals) with some delay (default is 10 seconds, look for
		2515	C<$AnyEvent::MAX_SIGNAL_LATENCY>).
		2516
		2517	If this module is available, then it will be used to implement signal
		2518	catching, which means that signals will not be delayed, and the event loop
		2519	will not be interrupted regularly, which is more efficient (and good for
		2520	battery life on laptops).
		2521
		2522	This affects not just the pure-perl event loop, but also other event loops
		2523	that have no signal handling on their own (e.g. Glib, Tk, Qt).
		2524
		2525	Some event loops (POE, Event, Event::Lib) offer signal watchers natively,
		2526	and either employ their own workarounds (POE) or use AnyEvent's workaround
		2527	(using C<$AnyEvent::MAX_SIGNAL_LATENCY>). Installing L<Async::Interrupt>
		2528	does nothing for those backends.
		2529
		2530	=item L<EV>
		2531
		2532	This module isn't really "optional", as it is simply one of the backend
		2533	event loops that AnyEvent can use. However, it is simply the best event
		2534	loop available in terms of features, speed and stability: It supports
		2535	the AnyEvent API optimally, implements all the watcher types in XS, does
		2536	automatic timer adjustments even when no monotonic clock is available,
		2537	can take avdantage of advanced kernel interfaces such as C<epoll> and
		2538	C<kqueue>, and is the fastest backend I<by far>. You can even embed
		2539	L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>).
		2540
		2541	If you only use backends that rely on another event loop (e.g. C<Tk>),
		2542	then this module will do nothing for you.
		2543
		2544	=item L<Guard>
		2545
		2546	The guard module, when used, will be used to implement
		2547	C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a
		2548	lot less memory), but otherwise doesn't affect guard operation much. It is
		2549	purely used for performance.
		2550
		2551	=item L<JSON> and L<JSON::XS>
		2552
		2553	One of these modules is required when you want to read or write JSON data
		2554	via L<AnyEvent::Handle>. L<JSON> is also written in pure-perl, but can take
		2555	advantage of the ultra-high-speed L<JSON::XS> module when it is installed.
		2556
		2557	=item L<Net::SSLeay>
		2558
		2559	Implementing TLS/SSL in Perl is certainly interesting, but not very
		2560	worthwhile: If this module is installed, then L<AnyEvent::Handle> (with
		2561	the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL.
		2562
		2563	=item L<Time::HiRes>
		2564
		2565	This module is part of perl since release 5.008. It will be used when the
		2566	chosen event library does not come with a timing source on it's own. The
		2567	pure-perl event loop (L<AnyEvent::Impl::Perl>) will additionally use it to
		2568	try to use a monotonic clock for timing stability.
		2569
		2570	=back
		2571
		2572
2137	=head1 FORK	2573	=head1 FORK
2138		2574
2139	Most event libraries are not fork-safe. The ones who are usually are	2575	Most event libraries are not fork-safe. The ones who are usually are
2140	because they rely on inefficient but fork-safe C<select> or C<poll>	2576	because they rely on inefficient but fork-safe C<select> or C<poll> calls
2141	calls. Only L<EV> is fully fork-aware.	2577	- higher performance APIs such as BSD's kqueue or the dreaded Linux epoll
		2578	are usually badly thought-out hacks that are incompatible with fork in
		2579	one way or another. Only L<EV> is fully fork-aware and ensures that you
		2580	continue event-processing in both parent and child (or both, if you know
		2581	what you are doing).
		2582
		2583	This means that, in general, you cannot fork and do event processing in
		2584	the child if the event library was initialised before the fork (which
		2585	usually happens when the first AnyEvent watcher is created, or the library
		2586	is loaded).
2142		2587
2143	If you have to fork, you must either do so I<before> creating your first	2588	If you have to fork, you must either do so I<before> creating your first
2144	watcher OR you must not use AnyEvent at all in the child.	2589	watcher OR you must not use AnyEvent at all in the child OR you must do
		2590	something completely out of the scope of AnyEvent.
		2591
		2592	The problem of doing event processing in the parent I<and> the child
		2593	is much more complicated: even for backends that I<are> fork-aware or
		2594	fork-safe, their behaviour is not usually what you want: fork clones all
		2595	watchers, that means all timers, I/O watchers etc. are active in both
		2596	parent and child, which is almost never what you want. USing C<exec>
		2597	to start worker children from some kind of manage rprocess is usually
		2598	preferred, because it is much easier and cleaner, at the expense of having
		2599	to have another binary.
2145		2600
2146		2601
2147	=head1 SECURITY CONSIDERATIONS	2602	=head1 SECURITY CONSIDERATIONS
2148		2603
2149	AnyEvent can be forced to load any event model via	2604	AnyEvent can be forced to load any event model via
…		…
2187	L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.	2642	L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.
2188		2643
2189	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,	2644	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,
2190	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,	2645	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,
2191	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,	2646	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,
2192	L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>.	2647	L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>, L<Anyevent::Impl::Irssi>.
2193		2648
2194	Non-blocking file handles, sockets, TCP clients and	2649	Non-blocking file handles, sockets, TCP clients and
2195	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.	2650	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.
2196		2651
2197	Asynchronous DNS: L<AnyEvent::DNS>.	2652	Asynchronous DNS: L<AnyEvent::DNS>.

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