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Revision 1.312 by root, Mon Feb 15 18:02:35 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
…		…
40	=head1 INTRODUCTION/TUTORIAL	40	=head1 INTRODUCTION/TUTORIAL
41		41
42	This manpage is mainly a reference manual. If you are interested	42	This manpage is mainly a reference manual. If you are interested
43	in a tutorial or some gentle introduction, have a look at the	43	in a tutorial or some gentle introduction, have a look at the
44	L<AnyEvent::Intro> manpage.	44	L<AnyEvent::Intro> manpage.
		45
		46	=head1 SUPPORT
		47
		48	There is a mailinglist for discussing all things AnyEvent, and an IRC
		49	channel, too.
		50
		51	See the AnyEvent project page at the B<Schmorpforge Ta-Sa Software
		52	Repository>, at L<http://anyevent.schmorp.de>, for more info.
45		53
46	=head1 WHY YOU SHOULD USE THIS MODULE (OR NOT)	54	=head1 WHY YOU SHOULD USE THIS MODULE (OR NOT)
47		55
48	Glib, POE, IO::Async, Event... CPAN offers event models by the dozen	56	Glib, POE, IO::Async, Event... CPAN offers event models by the dozen
49	nowadays. So what is different about AnyEvent?	57	nowadays. So what is different about AnyEvent?
…		…
173	my variables are only visible after the statement in which they are	181	my variables are only visible after the statement in which they are
174	declared.	182	declared.
175		183
176	=head2 I/O WATCHERS	184	=head2 I/O WATCHERS
177		185
		186	$w = AnyEvent->io (
		187	fh => <filehandle_or_fileno>,
		188	poll => <"r" or "w">,
		189	cb => <callback>,
		190	);
		191
178	You can create an I/O watcher by calling the C<< AnyEvent->io >> method	192	You can create an I/O watcher by calling the C<< AnyEvent->io >> method
179	with the following mandatory key-value pairs as arguments:	193	with the following mandatory key-value pairs as arguments:
180		194
181	C<fh> is the Perl I<file handle> (or a naked file descriptor) to watch	195	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	196	for events (AnyEvent might or might not keep a reference to this file
…		…
211	undef $w;	225	undef $w;
212	});	226	});
213		227
214	=head2 TIME WATCHERS	228	=head2 TIME WATCHERS
215		229
		230	$w = AnyEvent->timer (after => <seconds>, cb => <callback>);
		231
		232	$w = AnyEvent->timer (
		233	after => <fractional_seconds>,
		234	interval => <fractional_seconds>,
		235	cb => <callback>,
		236	);
		237
216	You can create a time watcher by calling the C<< AnyEvent->timer >>	238	You can create a time watcher by calling the C<< AnyEvent->timer >>
217	method with the following mandatory arguments:	239	method with the following mandatory arguments:
218		240
219	C<after> specifies after how many seconds (fractional values are	241	C<after> specifies after how many seconds (fractional values are
220	supported) the callback should be invoked. C<cb> is the callback to invoke	242	supported) the callback should be invoked. C<cb> is the callback to invoke
…		…
341	might affect timers and time-outs.	363	might affect timers and time-outs.
342		364
343	When this is the case, you can call this method, which will update the	365	When this is the case, you can call this method, which will update the
344	event loop's idea of "current time".	366	event loop's idea of "current time".
345		367
		368	A typical example would be a script in a web server (e.g. C<mod_perl>) -
		369	when mod_perl executes the script, then the event loop will have the wrong
		370	idea about the "current time" (being potentially far in the past, when the
		371	script ran the last time). In that case you should arrange a call to C<<
		372	AnyEvent->now_update >> each time the web server process wakes up again
		373	(e.g. at the start of your script, or in a handler).
		374
346	Note that updating the time I<might> cause some events to be handled.	375	Note that updating the time I<might> cause some events to be handled.
347		376
348	=back	377	=back
349		378
350	=head2 SIGNAL WATCHERS	379	=head2 SIGNAL WATCHERS
		380
		381	$w = AnyEvent->signal (signal => <uppercase_signal_name>, cb => <callback>);
351		382
352	You can watch for signals using a signal watcher, C<signal> is the signal	383	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	384	I<name> in uppercase and without any C<SIG> prefix, C<cb> is the Perl
354	callback to be invoked whenever a signal occurs.	385	callback to be invoked whenever a signal occurs.
355		386
…		…
361	invocation, and callback invocation will be synchronous. Synchronous means	392	invocation, and callback invocation will be synchronous. Synchronous means
362	that it might take a while until the signal gets handled by the process,	393	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.	394	but it is guaranteed not to interrupt any other callbacks.
364		395
365	The main advantage of using these watchers is that you can share a signal	396	The main advantage of using these watchers is that you can share a signal
366	between multiple watchers.	397	between multiple watchers, and AnyEvent will ensure that signals will not
		398	interrupt your program at bad times.
367		399
368	This watcher might use C<%SIG>, so programs overwriting those signals	400	This watcher might use C<%SIG> (depending on the event loop used),
369	directly will likely not work correctly.	401	so programs overwriting those signals directly will likely not work
		402	correctly.
370		403
371	Example: exit on SIGINT	404	Example: exit on SIGINT
372		405
373	my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });	406	my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });
374		407
		408	=head3 Restart Behaviour
		409
		410	While restart behaviour is up to the event loop implementation, most will
		411	not restart syscalls (that includes L<Async::Interrupt> and AnyEvent's
		412	pure perl implementation).
		413
		414	=head3 Safe/Unsafe Signals
		415
		416	Perl signals can be either "safe" (synchronous to opcode handling) or
		417	"unsafe" (asynchronous) - the former might get delayed indefinitely, the
		418	latter might corrupt your memory.
		419
		420	AnyEvent signal handlers are, in addition, synchronous to the event loop,
		421	i.e. they will not interrupt your running perl program but will only be
		422	called as part of the normal event handling (just like timer, I/O etc.
		423	callbacks, too).
		424
		425	=head3 Signal Races, Delays and Workarounds
		426
		427	Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support attaching
		428	callbacks to signals in a generic way, which is a pity, as you cannot
		429	do race-free signal handling in perl, requiring C libraries for
		430	this. AnyEvent will try to do it's best, which means in some cases,
		431	signals will be delayed. The maximum time a signal might be delayed is
		432	specified in C<$AnyEvent::MAX_SIGNAL_LATENCY> (default: 10 seconds). This
		433	variable can be changed only before the first signal watcher is created,
		434	and should be left alone otherwise. This variable determines how often
		435	AnyEvent polls for signals (in case a wake-up was missed). Higher values
		436	will cause fewer spurious wake-ups, which is better for power and CPU
		437	saving.
		438
		439	All these problems can be avoided by installing the optional
		440	L<Async::Interrupt> module, which works with most event loops. It will not
		441	work with inherently broken event loops such as L<Event> or L<Event::Lib>
		442	(and not with L<POE> currently, as POE does it's own workaround with
		443	one-second latency). For those, you just have to suffer the delays.
		444
375	=head2 CHILD PROCESS WATCHERS	445	=head2 CHILD PROCESS WATCHERS
376		446
		447	$w = AnyEvent->child (pid => <process id>, cb => <callback>);
		448
377	You can also watch on a child process exit and catch its exit status.	449	You can also watch on a child process exit and catch its exit status.
378		450
379	The child process is specified by the C<pid> argument (if set to C<0>, it	451	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	452	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	453	croak). The watcher will be triggered only when the child process has
382	any trace events (stopped/continued).	454	finished and an exit status is available, not on any trace events
		455	(stopped/continued).
383		456
384	The callback will be called with the pid and exit status (as returned by	457	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	458	waitpid), so unlike other watcher types, you I<can> rely on child watcher
386	callback arguments.	459	callback arguments.
387		460
…		…
403		476
404	This means you cannot create a child watcher as the very first	477	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	478	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	479	watcher before you C<fork> the child (alternatively, you can call
407	C<AnyEvent::detect>).	480	C<AnyEvent::detect>).
		481
		482	As most event loops do not support waiting for child events, they will be
		483	emulated by AnyEvent in most cases, in which the latency and race problems
		484	mentioned in the description of signal watchers apply.
408		485
409	Example: fork a process and wait for it	486	Example: fork a process and wait for it
410		487
411	my $done = AnyEvent->condvar;	488	my $done = AnyEvent->condvar;
412		489
…		…
424	# do something else, then wait for process exit	501	# do something else, then wait for process exit
425	$done->recv;	502	$done->recv;
426		503
427	=head2 IDLE WATCHERS	504	=head2 IDLE WATCHERS
428		505
429	Sometimes there is a need to do something, but it is not so important	506	$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		507
434	Idle watchers ideally get invoked when the event loop has nothing	508	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	509	either the watcher is destroyed or new events have been detected.
436	events. Instead of blocking, the idle watcher is invoked.
437		510
438	Most event loops unfortunately do not really support idle watchers (only	511	Idle watchers are useful when there is a need to do something, but it
		512	is not so important (or wise) to do it instantly. The callback will be
		513	invoked only when there is "nothing better to do", which is usually
		514	defined as "all outstanding events have been handled and no new events
		515	have been detected". That means that idle watchers ideally get invoked
		516	when the event loop has just polled for new events but none have been
		517	detected. Instead of blocking to wait for more events, the idle watchers
		518	will be invoked.
		519
		520	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	521	EV, Event and Glib do it in a usable fashion) - for the rest, AnyEvent
440	will simply call the callback "from time to time".	522	will simply call the callback "from time to time".
441		523
442	Example: read lines from STDIN, but only process them when the	524	Example: read lines from STDIN, but only process them when the
443	program is otherwise idle:	525	program is otherwise idle:
…		…
459	});	541	});
460	});	542	});
461		543
462	=head2 CONDITION VARIABLES	544	=head2 CONDITION VARIABLES
463		545
		546	$cv = AnyEvent->condvar;
		547
		548	$cv->send (<list>);
		549	my @res = $cv->recv;
		550
464	If you are familiar with some event loops you will know that all of them	551	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	552	require you to run some blocking "loop", "run" or similar function that
466	will actively watch for new events and call your callbacks.	553	will actively watch for new events and call your callbacks.
467		554
468	AnyEvent is different, it expects somebody else to run the event loop and	555	AnyEvent is slightly different: it expects somebody else to run the event
469	will only block when necessary (usually when told by the user).	556	loop and will only block when necessary (usually when told by the user).
470		557
471	The instrument to do that is called a "condition variable", so called	558	The instrument to do that is called a "condition variable", so called
472	because they represent a condition that must become true.	559	because they represent a condition that must become true.
473		560
		561	Now is probably a good time to look at the examples further below.
		562
474	Condition variables can be created by calling the C<< AnyEvent->condvar	563	Condition variables can be created by calling the C<< AnyEvent->condvar
475	>> method, usually without arguments. The only argument pair allowed is	564	>> method, usually without arguments. The only argument pair allowed is
476
477	C<cb>, which specifies a callback to be called when the condition variable	565	C<cb>, which specifies a callback to be called when the condition variable
478	becomes true, with the condition variable as the first argument (but not	566	becomes true, with the condition variable as the first argument (but not
479	the results).	567	the results).
480		568
481	After creation, the condition variable is "false" until it becomes "true"	569	After creation, the condition variable is "false" until it becomes "true"
…		…
486	Condition variables are similar to callbacks, except that you can	574	Condition variables are similar to callbacks, except that you can
487	optionally wait for them. They can also be called merge points - points	575	optionally wait for them. They can also be called merge points - points
488	in time where multiple outstanding events have been processed. And yet	576	in time where multiple outstanding events have been processed. And yet
489	another way to call them is transactions - each condition variable can be	577	another way to call them is transactions - each condition variable can be
490	used to represent a transaction, which finishes at some point and delivers	578	used to represent a transaction, which finishes at some point and delivers
491	a result.	579	a result. And yet some people know them as "futures" - a promise to
		580	compute/deliver something that you can wait for.
492		581
493	Condition variables are very useful to signal that something has finished,	582	Condition variables are very useful to signal that something has finished,
494	for example, if you write a module that does asynchronous http requests,	583	for example, if you write a module that does asynchronous http requests,
495	then a condition variable would be the ideal candidate to signal the	584	then a condition variable would be the ideal candidate to signal the
496	availability of results. The user can either act when the callback is	585	availability of results. The user can either act when the callback is
…		…
530	after => 1,	619	after => 1,
531	cb => sub { $result_ready->send },	620	cb => sub { $result_ready->send },
532	);	621	);
533		622
534	# this "blocks" (while handling events) till the callback	623	# this "blocks" (while handling events) till the callback
535	# calls send	624	# calls ->send
536	$result_ready->recv;	625	$result_ready->recv;
537		626
538	Example: wait for a timer, but take advantage of the fact that	627	Example: wait for a timer, but take advantage of the fact that condition
539	condition variables are also code references.	628	variables are also callable directly.
540		629
541	my $done = AnyEvent->condvar;	630	my $done = AnyEvent->condvar;
542	my $delay = AnyEvent->timer (after => 5, cb => $done);	631	my $delay = AnyEvent->timer (after => 5, cb => $done);
543	$done->recv;	632	$done->recv;
544		633
…		…
550		639
551	...	640	...
552		641
553	my @info = $couchdb->info->recv;	642	my @info = $couchdb->info->recv;
554		643
555	And this is how you would just ste a callback to be called whenever the	644	And this is how you would just set a callback to be called whenever the
556	results are available:	645	results are available:
557		646
558	$couchdb->info->cb (sub {	647	$couchdb->info->cb (sub {
559	my @info = $_[0]->recv;	648	my @info = $_[0]->recv;
560	});	649	});
…		…
578	immediately from within send.	667	immediately from within send.
579		668
580	Any arguments passed to the C<send> call will be returned by all	669	Any arguments passed to the C<send> call will be returned by all
581	future C<< ->recv >> calls.	670	future C<< ->recv >> calls.
582		671
583	Condition variables are overloaded so one can call them directly	672	Condition variables are overloaded so one can call them directly (as if
584	(as a code reference). Calling them directly is the same as calling	673	they were a code reference). Calling them directly is the same as calling
585	C<send>. Note, however, that many C-based event loops do not handle	674	C<send>.
586	overloading, so as tempting as it may be, passing a condition variable
587	instead of a callback does not work. Both the pure perl and EV loops
588	support overloading, however, as well as all functions that use perl to
589	invoke a callback (as in L<AnyEvent::Socket> and L<AnyEvent::DNS> for
590	example).
591		675
592	=item $cv->croak ($error)	676	=item $cv->croak ($error)
593		677
594	Similar to send, but causes all call's to C<< ->recv >> to invoke	678	Similar to send, but causes all call's to C<< ->recv >> to invoke
595	C<Carp::croak> with the given error message/object/scalar.	679	C<Carp::croak> with the given error message/object/scalar.
596		680
597	This can be used to signal any errors to the condition variable	681	This can be used to signal any errors to the condition variable
598	user/consumer.	682	user/consumer. Doing it this way instead of calling C<croak> directly
		683	delays the error detetcion, but has the overwhelmign advantage that it
		684	diagnoses the error at the place where the result is expected, and not
		685	deep in some event clalback without connection to the actual code causing
		686	the problem.
599		687
600	=item $cv->begin ([group callback])	688	=item $cv->begin ([group callback])
601		689
602	=item $cv->end	690	=item $cv->end
603		691
…		…
605	one. For example, a function that pings many hosts in parallel might want	693	one. For example, a function that pings many hosts in parallel might want
606	to use a condition variable for the whole process.	694	to use a condition variable for the whole process.
607		695
608	Every call to C<< ->begin >> will increment a counter, and every call to	696	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	697	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	698	>>, 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	699	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.	700	>>, but that is not required. If no group callback was set, C<send> will
		701	be called without any arguments.
613		702
614	You can think of C<< $cv->send >> giving you an OR condition (one call	703	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	704	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).	705	condition (all C<begin> calls must be C<end>'ed before the condvar sends).
617		706
…		…
644	begung can potentially be zero:	733	begung can potentially be zero:
645		734
646	my $cv = AnyEvent->condvar;	735	my $cv = AnyEvent->condvar;
647		736
648	my %result;	737	my %result;
649	$cv->begin (sub { $cv->send (\%result) });	738	$cv->begin (sub { shift->send (\%result) });
650		739
651	for my $host (@list_of_hosts) {	740	for my $host (@list_of_hosts) {
652	$cv->begin;	741	$cv->begin;
653	ping_host_then_call_callback $host, sub {	742	ping_host_then_call_callback $host, sub {
654	$result{$host} = ...;	743	$result{$host} = ...;
…		…
699	function will call C<croak>.	788	function will call C<croak>.
700		789
701	In list context, all parameters passed to C<send> will be returned,	790	In list context, all parameters passed to C<send> will be returned,
702	in scalar context only the first one will be returned.	791	in scalar context only the first one will be returned.
703		792
		793	Note that doing a blocking wait in a callback is not supported by any
		794	event loop, that is, recursive invocation of a blocking C<< ->recv
		795	>> is not allowed, and the C<recv> call will C<croak> if such a
		796	condition is detected. This condition can be slightly loosened by using
		797	L<Coro::AnyEvent>, which allows you to do a blocking C<< ->recv >> from
		798	any thread that doesn't run the event loop itself.
		799
704	Not all event models support a blocking wait - some die in that case	800	Not all event models support a blocking wait - some die in that case
705	(programs might want to do that to stay interactive), so I<if you are	801	(programs might want to do that to stay interactive), so I<if you are
706	using this from a module, never require a blocking wait>, but let the	802	using this from a module, never require a blocking wait>. Instead, let the
707	caller decide whether the call will block or not (for example, by coupling	803	caller decide whether the call will block or not (for example, by coupling
708	condition variables with some kind of request results and supporting	804	condition variables with some kind of request results and supporting
709	callbacks so the caller knows that getting the result will not block,	805	callbacks so the caller knows that getting the result will not block,
710	while still supporting blocking waits if the caller so desires).	806	while still supporting blocking waits if the caller so desires).
711		807
712	Another reason I<never> to C<< ->recv >> in a module is that you cannot
713	sensibly have two C<< ->recv >>'s in parallel, as that would require
714	multiple interpreters or coroutines/threads, none of which C<AnyEvent>
715	can supply.
716
717	The L<Coro> module, however, I<can> and I<does> supply coroutines and, in
718	fact, L<Coro::AnyEvent> replaces AnyEvent's condvars by coroutine-safe
719	versions and also integrates coroutines into AnyEvent, making blocking
720	C<< ->recv >> calls perfectly safe as long as they are done from another
721	coroutine (one that doesn't run the event loop).
722
723	You can ensure that C<< -recv >> never blocks by setting a callback and	808	You can ensure that C<< -recv >> never blocks by setting a callback and
724	only calling C<< ->recv >> from within that callback (or at a later	809	only calling C<< ->recv >> from within that callback (or at a later
725	time). This will work even when the event loop does not support blocking	810	time). This will work even when the event loop does not support blocking
726	waits otherwise.	811	waits otherwise.
727		812
…		…
733	=item $cb = $cv->cb ($cb->($cv))	818	=item $cb = $cv->cb ($cb->($cv))
734		819
735	This is a mutator function that returns the callback set and optionally	820	This is a mutator function that returns the callback set and optionally
736	replaces it before doing so.	821	replaces it before doing so.
737		822
738	The callback will be called when the condition becomes "true", i.e. when	823	The callback will be called when the condition becomes (or already was)
739	C<send> or C<croak> are called, with the only argument being the condition	824	"true", i.e. when C<send> or C<croak> are called (or were called), with
740	variable itself. Calling C<recv> inside the callback or at any later time	825	the only argument being the condition variable itself. Calling C<recv>
741	is guaranteed not to block.	826	inside the callback or at any later time is guaranteed not to block.
742		827
743	=back	828	=back
744		829
		830	=head1 SUPPORTED EVENT LOOPS/BACKENDS
		831
		832	The available backend classes are (every class has its own manpage):
		833
		834	=over 4
		835
		836	=item Backends that are autoprobed when no other event loop can be found.
		837
		838	EV is the preferred backend when no other event loop seems to be in
		839	use. If EV is not installed, then AnyEvent will fall back to its own
		840	pure-perl implementation, which is available everywhere as it comes with
		841	AnyEvent itself.
		842
		843	AnyEvent::Impl::EV based on EV (interface to libev, best choice).
		844	AnyEvent::Impl::Perl pure-perl implementation, fast and portable.
		845
		846	=item Backends that are transparently being picked up when they are used.
		847
		848	These will be used when they are currently loaded when the first watcher
		849	is created, in which case it is assumed that the application is using
		850	them. This means that AnyEvent will automatically pick the right backend
		851	when the main program loads an event module before anything starts to
		852	create watchers. Nothing special needs to be done by the main program.
		853
		854	AnyEvent::Impl::Event based on Event, very stable, few glitches.
		855	AnyEvent::Impl::Glib based on Glib, slow but very stable.
		856	AnyEvent::Impl::Tk based on Tk, very broken.
		857	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
		858	AnyEvent::Impl::POE based on POE, very slow, some limitations.
		859	AnyEvent::Impl::Irssi used when running within irssi.
		860
		861	=item Backends with special needs.
		862
		863	Qt requires the Qt::Application to be instantiated first, but will
		864	otherwise be picked up automatically. As long as the main program
		865	instantiates the application before any AnyEvent watchers are created,
		866	everything should just work.
		867
		868	AnyEvent::Impl::Qt based on Qt.
		869
		870	Support for IO::Async can only be partial, as it is too broken and
		871	architecturally limited to even support the AnyEvent API. It also
		872	is the only event loop that needs the loop to be set explicitly, so
		873	it can only be used by a main program knowing about AnyEvent. See
		874	L<AnyEvent::Impl::Async> for the gory details.
		875
		876	AnyEvent::Impl::IOAsync based on IO::Async, cannot be autoprobed.
		877
		878	=item Event loops that are indirectly supported via other backends.
		879
		880	Some event loops can be supported via other modules:
		881
		882	There is no direct support for WxWidgets (L<Wx>) or L<Prima>.
		883
		884	B<WxWidgets> has no support for watching file handles. However, you can
		885	use WxWidgets through the POE adaptor, as POE has a Wx backend that simply
		886	polls 20 times per second, which was considered to be too horrible to even
		887	consider for AnyEvent.
		888
		889	B<Prima> is not supported as nobody seems to be using it, but it has a POE
		890	backend, so it can be supported through POE.
		891
		892	AnyEvent knows about both L<Prima> and L<Wx>, however, and will try to
		893	load L<POE> when detecting them, in the hope that POE will pick them up,
		894	in which case everything will be automatic.
		895
		896	=back
		897
745	=head1 GLOBAL VARIABLES AND FUNCTIONS	898	=head1 GLOBAL VARIABLES AND FUNCTIONS
746		899
		900	These are not normally required to use AnyEvent, but can be useful to
		901	write AnyEvent extension modules.
		902
747	=over 4	903	=over 4
748		904
749	=item $AnyEvent::MODEL	905	=item $AnyEvent::MODEL
750		906
751	Contains C<undef> until the first watcher is being created. Then it	907	Contains C<undef> until the first watcher is being created, before the
		908	backend has been autodetected.
		909
752	contains the event model that is being used, which is the name of the	910	Afterwards it contains the event model that is being used, which is the
753	Perl class implementing the model. This class is usually one of the	911	name of the Perl class implementing the model. This class is usually one
754	C<AnyEvent::Impl:xxx> modules, but can be any other class in the case	912	of the C<AnyEvent::Impl:xxx> modules, but can be any other class in the
755	AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode>).	913	case AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode> it
756		914	will be C<urxvt::anyevent>).
757	The known classes so far are:
758
759	AnyEvent::Impl::EV based on EV (an interface to libev, best choice).
760	AnyEvent::Impl::Event based on Event, second best choice.
761	AnyEvent::Impl::Perl pure-perl implementation, fast and portable.
762	AnyEvent::Impl::Glib based on Glib, third-best choice.
763	AnyEvent::Impl::Tk based on Tk, very bad choice.
764	AnyEvent::Impl::Qt based on Qt, cannot be autoprobed (see its docs).
765	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
766	AnyEvent::Impl::POE based on POE, not generic enough for full support.
767
768	# warning, support for IO::Async is only partial, as it is too broken
769	# and limited toe ven support the AnyEvent API. See AnyEvent::Impl::Async.
770	AnyEvent::Impl::IOAsync based on IO::Async, cannot be autoprobed (see its docs).
771
772	There is no support for WxWidgets, as WxWidgets has no support for
773	watching file handles. However, you can use WxWidgets through the
774	POE Adaptor, as POE has a Wx backend that simply polls 20 times per
775	second, which was considered to be too horrible to even consider for
776	AnyEvent. Likewise, other POE backends can be used by AnyEvent by using
777	it's adaptor.
778
779	AnyEvent knows about L<Prima> and L<Wx> and will try to use L<POE> when
780	autodetecting them.
781		915
782	=item AnyEvent::detect	916	=item AnyEvent::detect
783		917
784	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model	918	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model
785	if necessary. You should only call this function right before you would	919	if necessary. You should only call this function right before you would
786	have created an AnyEvent watcher anyway, that is, as late as possible at	920	have created an AnyEvent watcher anyway, that is, as late as possible at
787	runtime.	921	runtime, and not e.g. while initialising of your module.
		922
		923	If you need to do some initialisation before AnyEvent watchers are
		924	created, use C<post_detect>.
788		925
789	=item $guard = AnyEvent::post_detect { BLOCK }	926	=item $guard = AnyEvent::post_detect { BLOCK }
790		927
791	Arranges for the code block to be executed as soon as the event model is	928	Arranges for the code block to be executed as soon as the event model is
792	autodetected (or immediately if this has already happened).	929	autodetected (or immediately if this has already happened).
793		930
		931	The block will be executed I<after> the actual backend has been detected
		932	(C<$AnyEvent::MODEL> is set), but I<before> any watchers have been
		933	created, so it is possible to e.g. patch C<@AnyEvent::ISA> or do
		934	other initialisations - see the sources of L<AnyEvent::Strict> or
		935	L<AnyEvent::AIO> to see how this is used.
		936
		937	The most common usage is to create some global watchers, without forcing
		938	event module detection too early, for example, L<AnyEvent::AIO> creates
		939	and installs the global L<IO::AIO> watcher in a C<post_detect> block to
		940	avoid autodetecting the event module at load time.
		941
794	If called in scalar or list context, then it creates and returns an object	942	If called in scalar or list context, then it creates and returns an object
795	that automatically removes the callback again when it is destroyed. See	943	that automatically removes the callback again when it is destroyed (or
		944	C<undef> when the hook was immediately executed). See L<AnyEvent::AIO> for
796	L<Coro::BDB> for a case where this is useful.	945	a case where this is useful.
		946
		947	Example: Create a watcher for the IO::AIO module and store it in
		948	C<$WATCHER>. Only do so after the event loop is initialised, though.
		949
		950	our WATCHER;
		951
		952	my $guard = AnyEvent::post_detect {
		953	$WATCHER = AnyEvent->io (fh => IO::AIO::poll_fileno, poll => 'r', cb => \&IO::AIO::poll_cb);
		954	};
		955
		956	# the ||= is important in case post_detect immediately runs the block,
		957	# as to not clobber the newly-created watcher. assigning both watcher and
		958	# post_detect guard to the same variable has the advantage of users being
		959	# able to just C<undef $WATCHER> if the watcher causes them grief.
		960
		961	$WATCHER ||= $guard;
797		962
798	=item @AnyEvent::post_detect	963	=item @AnyEvent::post_detect
799		964
800	If there are any code references in this array (you can C<push> to it	965	If there are any code references in this array (you can C<push> to it
801	before or after loading AnyEvent), then they will called directly after	966	before or after loading AnyEvent), then they will called directly after
802	the event loop has been chosen.	967	the event loop has been chosen.
803		968
804	You should check C<$AnyEvent::MODEL> before adding to this array, though:	969	You should check C<$AnyEvent::MODEL> before adding to this array, though:
805	if it contains a true value then the event loop has already been detected,	970	if it is defined then the event loop has already been detected, and the
806	and the array will be ignored.	971	array will be ignored.
807		972
808	Best use C<AnyEvent::post_detect { BLOCK }> instead.	973	Best use C<AnyEvent::post_detect { BLOCK }> when your application allows
		974	it, as it takes care of these details.
		975
		976	This variable is mainly useful for modules that can do something useful
		977	when AnyEvent is used and thus want to know when it is initialised, but do
		978	not need to even load it by default. This array provides the means to hook
		979	into AnyEvent passively, without loading it.
		980
		981	Example: To load Coro::AnyEvent whenever Coro and AnyEvent are used
		982	together, you could put this into Coro (this is the actual code used by
		983	Coro to accomplish this):
		984
		985	if (defined $AnyEvent::MODEL) {
		986	# AnyEvent already initialised, so load Coro::AnyEvent
		987	require Coro::AnyEvent;
		988	} else {
		989	# AnyEvent not yet initialised, so make sure to load Coro::AnyEvent
		990	# as soon as it is
		991	push @AnyEvent::post_detect, sub { require Coro::AnyEvent };
		992	}
809		993
810	=back	994	=back
811		995
812	=head1 WHAT TO DO IN A MODULE	996	=head1 WHAT TO DO IN A MODULE
813		997
…		…
868		1052
869		1053
870	=head1 OTHER MODULES	1054	=head1 OTHER MODULES
871		1055
872	The following is a non-exhaustive list of additional modules that use	1056	The following is a non-exhaustive list of additional modules that use
873	AnyEvent and can therefore be mixed easily with other AnyEvent modules	1057	AnyEvent as a client and can therefore be mixed easily with other AnyEvent
874	in the same program. Some of the modules come with AnyEvent, some are	1058	modules and other event loops in the same program. Some of the modules
875	available via CPAN.	1059	come with AnyEvent, most are available via CPAN.
876		1060
877	=over 4	1061	=over 4
878		1062
879	=item L<AnyEvent::Util>	1063	=item L<AnyEvent::Util>
880		1064
…		…
889		1073
890	=item L<AnyEvent::Handle>	1074	=item L<AnyEvent::Handle>
891		1075
892	Provide read and write buffers, manages watchers for reads and writes,	1076	Provide read and write buffers, manages watchers for reads and writes,
893	supports raw and formatted I/O, I/O queued and fully transparent and	1077	supports raw and formatted I/O, I/O queued and fully transparent and
894	non-blocking SSL/TLS.	1078	non-blocking SSL/TLS (via L<AnyEvent::TLS>.
895		1079
896	=item L<AnyEvent::DNS>	1080	=item L<AnyEvent::DNS>
897		1081
898	Provides rich asynchronous DNS resolver capabilities.	1082	Provides rich asynchronous DNS resolver capabilities.
899		1083
…		…
927		1111
928	=item L<AnyEvent::GPSD>	1112	=item L<AnyEvent::GPSD>
929		1113
930	A non-blocking interface to gpsd, a daemon delivering GPS information.	1114	A non-blocking interface to gpsd, a daemon delivering GPS information.
931		1115
		1116	=item L<AnyEvent::IRC>
		1117
		1118	AnyEvent based IRC client module family (replacing the older Net::IRC3).
		1119
		1120	=item L<AnyEvent::XMPP>
		1121
		1122	AnyEvent based XMPP (Jabber protocol) module family (replacing the older
		1123	Net::XMPP2>.
		1124
932	=item L<AnyEvent::IGS>	1125	=item L<AnyEvent::IGS>
933		1126
934	A non-blocking interface to the Internet Go Server protocol (used by	1127	A non-blocking interface to the Internet Go Server protocol (used by
935	L<App::IGS>).	1128	L<App::IGS>).
936		1129
937	=item L<AnyEvent::IRC>
938
939	AnyEvent based IRC client module family (replacing the older Net::IRC3).
940
941	=item L<Net::XMPP2>
942
943	AnyEvent based XMPP (Jabber protocol) module family.
944
945	=item L<Net::FCP>	1130	=item L<Net::FCP>
946		1131
947	AnyEvent-based implementation of the Freenet Client Protocol, birthplace	1132	AnyEvent-based implementation of the Freenet Client Protocol, birthplace
948	of AnyEvent.	1133	of AnyEvent.
949		1134
…		…
953		1138
954	=item L<Coro>	1139	=item L<Coro>
955		1140
956	Has special support for AnyEvent via L<Coro::AnyEvent>.	1141	Has special support for AnyEvent via L<Coro::AnyEvent>.
957		1142
958	=item L<IO::Lambda>
959
960	The lambda approach to I/O - don't ask, look there. Can use AnyEvent.
961
962	=back	1143	=back
963		1144
964	=cut	1145	=cut
965		1146
966	package AnyEvent;	1147	package AnyEvent;
967		1148
968	no warnings;	1149	# basically a tuned-down version of common::sense
969	use strict qw(vars subs);	1150	sub common_sense {
		1151	# from common:.sense 1.0
		1152	${^WARNING_BITS} = "\xfc\x3f\x33\x00\x0f\xf3\xcf\xc0\xf3\xfc\x33\x00";
		1153	# use strict vars subs - NO UTF-8, as Util.pm doesn't like this atm. (uts46data.pl)
		1154	$^H |= 0x00000600;
		1155	}
970		1156
		1157	BEGIN { AnyEvent::common_sense }
		1158
971	use Carp;	1159	use Carp ();
972		1160
973	our $VERSION = 4.8;	1161	our $VERSION = '5.24';
974	our $MODEL;	1162	our $MODEL;
975		1163
976	our $AUTOLOAD;	1164	our $AUTOLOAD;
977	our @ISA;	1165	our @ISA;
978		1166
979	our @REGISTRY;	1167	our @REGISTRY;
980		1168
981	our $WIN32;	1169	our $VERBOSE;
982		1170
983	BEGIN {	1171	BEGIN {
		1172	eval "sub CYGWIN(){" . (($^O =~ /cygwin/i) *1) . "}";
984	eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }";	1173	eval "sub WIN32 (){" . (($^O =~ /mswin32/i)*1) . "}";
985	eval "sub TAINT(){ " . (${^TAINT}*1) . " }";	1174	eval "sub TAINT (){" . (${^TAINT} *1) . "}";
986		1175
987	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}	1176	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}
988	if ${^TAINT};	1177	if ${^TAINT};
989	}
990		1178
991	our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1;	1179	$VERBOSE = $ENV{PERL_ANYEVENT_VERBOSE}*1;
		1180
		1181	}
		1182
		1183	our $MAX_SIGNAL_LATENCY = 10;
992		1184
993	our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred	1185	our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred
994		1186
995	{	1187	{
996	my $idx;	1188	my $idx;
…		…
998	for reverse split /\s*,\s*/,	1190	for reverse split /\s*,\s*/,
999	$ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";	1191	$ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";
1000	}	1192	}
1001		1193
1002	my @models = (	1194	my @models = (
1003	[EV:: => AnyEvent::Impl::EV::],	1195	[EV:: => AnyEvent::Impl::EV:: , 1],
1004	[Event:: => AnyEvent::Impl::Event::],
1005	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::],	1196	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl:: , 1],
1006	# everything below here will not be autoprobed	1197	# everything below here will not (normally) be autoprobed
1007	# as the pureperl backend should work everywhere	1198	# as the pureperl backend should work everywhere
1008	# and is usually faster	1199	# and is usually faster
		1200	[Event:: => AnyEvent::Impl::Event::, 1],
		1201	[Glib:: => AnyEvent::Impl::Glib:: , 1], # becomes extremely slow with many watchers
		1202	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
		1203	[Irssi:: => AnyEvent::Impl::Irssi::], # Irssi has a bogus "Event" package
1009	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles	1204	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
1010	[Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers
1011	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
1012	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program	1205	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program
1013	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza	1206	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
1014	[Wx:: => AnyEvent::Impl::POE::],	1207	[Wx:: => AnyEvent::Impl::POE::],
1015	[Prima:: => AnyEvent::Impl::POE::],	1208	[Prima:: => AnyEvent::Impl::POE::],
1016	# IO::Async is just too broken - we would need workaorunds for its	1209	# IO::Async is just too broken - we would need workarounds for its
1017	# byzantine signal and broken child handling, among others.	1210	# byzantine signal and broken child handling, among others.
1018	# IO::Async is rather hard to detect, as it doesn't have any	1211	# IO::Async is rather hard to detect, as it doesn't have any
1019	# obvious default class.	1212	# obvious default class.
1020	# [IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program	1213	[IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program
1021	# [IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program	1214	[IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program
1022	# [IO::Async::Notifier:: => AnyEvent::Impl::IOAsync::], # requires special main program	1215	[IO::Async::Notifier:: => AnyEvent::Impl::IOAsync::], # requires special main program
		1216	[AnyEvent::Impl::IOAsync:: => AnyEvent::Impl::IOAsync::], # requires special main program
1023	);	1217	);
1024		1218
1025	our %method = map +($_ => 1),	1219	our %method = map +($_ => 1),
1026	qw(io timer time now now_update signal child idle condvar one_event DESTROY);	1220	qw(io timer time now now_update signal child idle condvar one_event DESTROY);
1027		1221
…		…
1031	my ($cb) = @_;	1225	my ($cb) = @_;
1032		1226
1033	if ($MODEL) {	1227	if ($MODEL) {
1034	$cb->();	1228	$cb->();
1035		1229
1036	1	1230	undef
1037	} else {	1231	} else {
1038	push @post_detect, $cb;	1232	push @post_detect, $cb;
1039		1233
1040	defined wantarray	1234	defined wantarray
1041	? bless \$cb, "AnyEvent::Util::postdetect"	1235	? bless \$cb, "AnyEvent::Util::postdetect"
…		…
1046	sub AnyEvent::Util::postdetect::DESTROY {	1240	sub AnyEvent::Util::postdetect::DESTROY {
1047	@post_detect = grep $_ != ${$_[0]}, @post_detect;	1241	@post_detect = grep $_ != ${$_[0]}, @post_detect;
1048	}	1242	}
1049		1243
1050	sub detect() {	1244	sub detect() {
		1245	# free some memory
		1246	*detect = sub () { $MODEL };
		1247
		1248	local $!; # for good measure
		1249	local $SIG{__DIE__};
		1250
		1251	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {
		1252	my $model = "AnyEvent::Impl::$1";
		1253	if (eval "require $model") {
		1254	$MODEL = $model;
		1255	warn "AnyEvent: loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.\n" if $VERBOSE >= 2;
		1256	} else {
		1257	warn "AnyEvent: unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@" if $VERBOSE;
		1258	}
		1259	}
		1260
		1261	# check for already loaded models
1051	unless ($MODEL) {	1262	unless ($MODEL) {
1052	no strict 'refs';	1263	for (@REGISTRY, @models) {
1053	local $SIG{__DIE__};	1264	my ($package, $model) = @$_;
1054		1265	if (${"$package\::VERSION"} > 0) {
1055	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {
1056	my $model = "AnyEvent::Impl::$1";
1057	if (eval "require $model") {	1266	if (eval "require $model") {
1058	$MODEL = $model;	1267	$MODEL = $model;
1059	warn "AnyEvent: loaded model '$model' (forced by \$PERL_ANYEVENT_MODEL), using it.\n" if $verbose > 1;	1268	warn "AnyEvent: autodetected model '$model', using it.\n" if $VERBOSE >= 2;
1060	} else {	1269	last;
1061	warn "AnyEvent: unable to load model '$model' (from \$PERL_ANYEVENT_MODEL):\n$@" if $verbose;	1270	}
1062	}	1271	}
1063	}	1272	}
1064		1273
1065	# check for already loaded models
1066	unless ($MODEL) {	1274	unless ($MODEL) {
		1275	# try to autoload a model
1067	for (@REGISTRY, @models) {	1276	for (@REGISTRY, @models) {
1068	my ($package, $model) = @$_;	1277	my ($package, $model, $autoload) = @$_;
		1278	if (
		1279	$autoload
		1280	and eval "require $package"
1069	if (${"$package\::VERSION"} > 0) {	1281	and ${"$package\::VERSION"} > 0
1070	if (eval "require $model") {	1282	and eval "require $model"
		1283	) {
1071	$MODEL = $model;	1284	$MODEL = $model;
1072	warn "AnyEvent: autodetected model '$model', using it.\n" if $verbose > 1;	1285	warn "AnyEvent: autoloaded model '$model', using it.\n" if $VERBOSE >= 2;
1073	last;	1286	last;
1074	}
1075	}	1287	}
1076	}	1288	}
1077		1289
1078	unless ($MODEL) {
1079	# try to load a model
1080
1081	for (@REGISTRY, @models) {
1082	my ($package, $model) = @$_;
1083	if (eval "require $package"
1084	and ${"$package\::VERSION"} > 0
1085	and eval "require $model") {
1086	$MODEL = $model;
1087	warn "AnyEvent: autoprobed model '$model', using it.\n" if $verbose > 1;
1088	last;
1089	}
1090	}
1091
1092	$MODEL	1290	$MODEL
1093	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.\n";	1291	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.\n";
1094	}
1095	}	1292	}
1096
1097	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
1098
1099	unshift @ISA, $MODEL;
1100
1101	require AnyEvent::Strict if $ENV{PERL_ANYEVENT_STRICT};
1102
1103	(shift @post_detect)->() while @post_detect;
1104	}	1293	}
		1294
		1295	@models = (); # free probe data
		1296
		1297	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
		1298	unshift @ISA, $MODEL;
		1299
		1300	require AnyEvent::Strict if $ENV{PERL_ANYEVENT_STRICT};
		1301
		1302	(shift @post_detect)->() while @post_detect;
1105		1303
1106	$MODEL	1304	$MODEL
1107	}	1305	}
1108		1306
1109	sub AUTOLOAD {	1307	sub AUTOLOAD {
1110	(my $func = $AUTOLOAD) =~ s/.*://;	1308	(my $func = $AUTOLOAD) =~ s/.*://;
1111		1309
1112	$method{$func}	1310	$method{$func}
1113	or croak "$func: not a valid method for AnyEvent objects";	1311	or Carp::croak "$func: not a valid AnyEvent class method";
1114		1312
1115	detect unless $MODEL;	1313	detect;
1116		1314
1117	my $class = shift;	1315	my $class = shift;
1118	$class->$func (@_);	1316	$class->$func (@_);
1119	}	1317	}
1120		1318
…		…
1123	# allow only one watcher per fd, so we dup it to get a different one).	1321	# allow only one watcher per fd, so we dup it to get a different one).
1124	sub _dupfh($$;$$) {	1322	sub _dupfh($$;$$) {
1125	my ($poll, $fh, $r, $w) = @_;	1323	my ($poll, $fh, $r, $w) = @_;
1126		1324
1127	# cygwin requires the fh mode to be matching, unix doesn't	1325	# cygwin requires the fh mode to be matching, unix doesn't
1128	my ($rw, $mode) = $poll eq "r" ? ($r, "<") : ($w, ">");	1326	my ($rw, $mode) = $poll eq "r" ? ($r, "<&") : ($w, ">&");
1129		1327
1130	open my $fh2, "$mode&", $fh	1328	open my $fh2, $mode, $fh
1131	or die "AnyEvent->io: cannot dup() filehandle in mode '$poll': $!,";	1329	or die "AnyEvent->io: cannot dup() filehandle in mode '$poll': $!,";
1132		1330
1133	# we assume CLOEXEC is already set by perl in all important cases	1331	# we assume CLOEXEC is already set by perl in all important cases
1134		1332
1135	($fh2, $rw)	1333	($fh2, $rw)
1136	}	1334	}
1137		1335
		1336	=head1 SIMPLIFIED AE API
		1337
		1338	Starting with version 5.0, AnyEvent officially supports a second, much
		1339	simpler, API that is designed to reduce the calling, typing and memory
		1340	overhead.
		1341
		1342	See the L<AE> manpage for details.
		1343
		1344	=cut
		1345
		1346	package AE;
		1347
		1348	our $VERSION = $AnyEvent::VERSION;
		1349
		1350	sub io($$$) {
		1351	AnyEvent->io (fh => $_[0], poll => $_[1] ? "w" : "r", cb => $_[2])
		1352	}
		1353
		1354	sub timer($$$) {
		1355	AnyEvent->timer (after => $_[0], interval => $_[1], cb => $_[2])
		1356	}
		1357
		1358	sub signal($$) {
		1359	AnyEvent->signal (signal => $_[0], cb => $_[1])
		1360	}
		1361
		1362	sub child($$) {
		1363	AnyEvent->child (pid => $_[0], cb => $_[1])
		1364	}
		1365
		1366	sub idle($) {
		1367	AnyEvent->idle (cb => $_[0])
		1368	}
		1369
		1370	sub cv(;&) {
		1371	AnyEvent->condvar (@_ ? (cb => $_[0]) : ())
		1372	}
		1373
		1374	sub now() {
		1375	AnyEvent->now
		1376	}
		1377
		1378	sub now_update() {
		1379	AnyEvent->now_update
		1380	}
		1381
		1382	sub time() {
		1383	AnyEvent->time
		1384	}
		1385
1138	package AnyEvent::Base;	1386	package AnyEvent::Base;
1139		1387
1140	# default implementations for many methods	1388	# default implementations for many methods
1141		1389
1142	BEGIN {	1390	sub _time() {
		1391	eval q{ # poor man's autoloading
		1392	# probe for availability of Time::HiRes
1143	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {	1393	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {
		1394	warn "AnyEvent: using Time::HiRes for sub-second timing accuracy.\n" if $VERBOSE >= 8;
1144	*_time = \&Time::HiRes::time;	1395	*_time = \&Time::HiRes::time;
1145	# if (eval "use POSIX (); (POSIX::times())...	1396	# if (eval "use POSIX (); (POSIX::times())...
1146	} else {	1397	} else {
		1398	warn "AnyEvent: using built-in time(), WARNING, no sub-second resolution!\n" if $VERBOSE;
1147	*_time = sub { time }; # epic fail	1399	*_time = sub (){ time }; # epic fail
		1400	}
1148	}	1401	};
		1402	die if $@;
		1403
		1404	&_time
1149	}	1405	}
1150		1406
1151	sub time { _time }	1407	sub time { _time }
1152	sub now { _time }	1408	sub now { _time }
1153	sub now_update { }	1409	sub now_update { }
…		…
1158	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"	1414	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"
1159	}	1415	}
1160		1416
1161	# default implementation for ->signal	1417	# default implementation for ->signal
1162		1418
		1419	our $HAVE_ASYNC_INTERRUPT;
		1420
		1421	sub _have_async_interrupt() {
		1422	$HAVE_ASYNC_INTERRUPT = 1*(!$ENV{PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT}
		1423	&& eval "use Async::Interrupt 1.02 (); 1")
		1424	unless defined $HAVE_ASYNC_INTERRUPT;
		1425
		1426	$HAVE_ASYNC_INTERRUPT
		1427	}
		1428
1163	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);	1429	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);
		1430	our (%SIG_ASY, %SIG_ASY_W);
		1431	our ($SIG_COUNT, $SIG_TW);
1164		1432
1165	sub _signal_exec {	1433	# install a dummy wakeup watcher to reduce signal catching latency
1166	sysread $SIGPIPE_R, my $dummy, 4;	1434	# used by Impls
		1435	sub _sig_add() {
		1436	unless ($SIG_COUNT++) {
		1437	# try to align timer on a full-second boundary, if possible
		1438	my $NOW = AE::now;
1167		1439
1168	while (%SIG_EV) {	1440	$SIG_TW = AE::timer
1169	for (keys %SIG_EV) {	1441	$MAX_SIGNAL_LATENCY - ($NOW - int $NOW),
1170	delete $SIG_EV{$_};	1442	$MAX_SIGNAL_LATENCY,
1171	$_->() for values %{ $SIG_CB{$_} || {} };	1443	sub { } # just for the PERL_ASYNC_CHECK
		1444	;
		1445	}
		1446	}
		1447
		1448	sub _sig_del {
		1449	undef $SIG_TW
		1450	unless --$SIG_COUNT;
		1451	}
		1452
		1453	our $_sig_name_init; $_sig_name_init = sub {
		1454	eval q{ # poor man's autoloading
		1455	undef $_sig_name_init;
		1456
		1457	if (_have_async_interrupt) {
		1458	*sig2num = \&Async::Interrupt::sig2num;
		1459	*sig2name = \&Async::Interrupt::sig2name;
		1460	} else {
		1461	require Config;
		1462
		1463	my %signame2num;
		1464	@signame2num{ split ' ', $Config::Config{sig_name} }
		1465	= split ' ', $Config::Config{sig_num};
		1466
		1467	my @signum2name;
		1468	@signum2name[values %signame2num] = keys %signame2num;
		1469
		1470	*sig2num = sub($) {
		1471	$_[0] > 0 ? shift : $signame2num{+shift}
		1472	};
		1473	*sig2name = sub ($) {
		1474	$_[0] > 0 ? $signum2name[+shift] : shift
		1475	};
1172	}	1476	}
1173	}	1477	};
1174	}	1478	die if $@;
		1479	};
		1480
		1481	sub sig2num ($) { &$_sig_name_init; &sig2num }
		1482	sub sig2name($) { &$_sig_name_init; &sig2name }
1175		1483
1176	sub signal {	1484	sub signal {
1177	my (undef, %arg) = @_;	1485	eval q{ # poor man's autoloading {}
		1486	# probe for availability of Async::Interrupt
		1487	if (_have_async_interrupt) {
		1488	warn "AnyEvent: using Async::Interrupt for race-free signal handling.\n" if $VERBOSE >= 8;
1178		1489
1179	unless ($SIGPIPE_R) {	1490	$SIGPIPE_R = new Async::Interrupt::EventPipe;
1180	require Fcntl;	1491	$SIG_IO = AE::io $SIGPIPE_R->fileno, 0, \&_signal_exec;
1181		1492
1182	if (AnyEvent::WIN32) {
1183	require AnyEvent::Util;
1184
1185	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
1186	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R) if $SIGPIPE_R;
1187	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W) if $SIGPIPE_W; # just in case
1188	} else {	1493	} else {
		1494	warn "AnyEvent: using emulated perl signal handling with latency timer.\n" if $VERBOSE >= 8;
		1495
		1496	require Fcntl;
		1497
		1498	if (AnyEvent::WIN32) {
		1499	require AnyEvent::Util;
		1500
		1501	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
		1502	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R, 1) if $SIGPIPE_R;
		1503	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W, 1) if $SIGPIPE_W; # just in case
		1504	} else {
1189	pipe $SIGPIPE_R, $SIGPIPE_W;	1505	pipe $SIGPIPE_R, $SIGPIPE_W;
1190	fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R;	1506	fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R;
1191	fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case	1507	fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case
1192		1508
1193	# not strictly required, as $^F is normally 2, but let's make sure...	1509	# not strictly required, as $^F is normally 2, but let's make sure...
1194	fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;	1510	fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
1195	fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;	1511	fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
		1512	}
		1513
		1514	$SIGPIPE_R
		1515	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";
		1516
		1517	$SIG_IO = AE::io $SIGPIPE_R, 0, \&_signal_exec;
1196	}	1518	}
1197		1519
1198	$SIGPIPE_R	1520	*signal = sub {
1199	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";	1521	my (undef, %arg) = @_;
1200		1522
1201	$SIG_IO = AnyEvent->io (fh => $SIGPIPE_R, poll => "r", cb => \&_signal_exec);
1202	}
1203
1204	my $signal = uc $arg{signal}	1523	my $signal = uc $arg{signal}
1205	or Carp::croak "required option 'signal' is missing";	1524	or Carp::croak "required option 'signal' is missing";
1206		1525
		1526	if ($HAVE_ASYNC_INTERRUPT) {
		1527	# async::interrupt
		1528
		1529	$signal = sig2num $signal;
1207	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};	1530	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
		1531
		1532	$SIG_ASY{$signal} ||= new Async::Interrupt
		1533	cb => sub { undef $SIG_EV{$signal} },
		1534	signal => $signal,
		1535	pipe => [$SIGPIPE_R->filenos],
		1536	pipe_autodrain => 0,
		1537	;
		1538
		1539	} else {
		1540	# pure perl
		1541
		1542	# AE::Util has been loaded in signal
		1543	$signal = sig2name $signal;
		1544	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
		1545
1208	$SIG{$signal} ||= sub {	1546	$SIG{$signal} ||= sub {
1209	local $!;	1547	local $!;
1210	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;	1548	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;
1211	undef $SIG_EV{$signal};	1549	undef $SIG_EV{$signal};
		1550	};
		1551
		1552	# can't do signal processing without introducing races in pure perl,
		1553	# so limit the signal latency.
		1554	_sig_add;
		1555	}
		1556
		1557	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
		1558	};
		1559
		1560	*AnyEvent::Base::signal::DESTROY = sub {
		1561	my ($signal, $cb) = @{$_[0]};
		1562
		1563	_sig_del;
		1564
		1565	delete $SIG_CB{$signal}{$cb};
		1566
		1567	$HAVE_ASYNC_INTERRUPT
		1568	? delete $SIG_ASY{$signal}
		1569	: # delete doesn't work with older perls - they then
		1570	# print weird messages, or just unconditionally exit
		1571	# instead of getting the default action.
		1572	undef $SIG{$signal}
		1573	unless keys %{ $SIG_CB{$signal} };
		1574	};
		1575
		1576	*_signal_exec = sub {
		1577	$HAVE_ASYNC_INTERRUPT
		1578	? $SIGPIPE_R->drain
		1579	: sysread $SIGPIPE_R, (my $dummy), 9;
		1580
		1581	while (%SIG_EV) {
		1582	for (keys %SIG_EV) {
		1583	delete $SIG_EV{$_};
		1584	$_->() for values %{ $SIG_CB{$_} || {} };
		1585	}
		1586	}
		1587	};
1212	};	1588	};
		1589	die if $@;
1213		1590
1214	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"	1591	&signal
1215	}
1216
1217	sub AnyEvent::Base::signal::DESTROY {
1218	my ($signal, $cb) = @{$_[0]};
1219
1220	delete $SIG_CB{$signal}{$cb};
1221
1222	# delete doesn't work with older perls - they then
1223	# print weird messages, or just unconditionally exit
1224	# instead of getting the default action.
1225	undef $SIG{$signal} unless keys %{ $SIG_CB{$signal} };
1226	}	1592	}
1227		1593
1228	# default implementation for ->child	1594	# default implementation for ->child
1229		1595
1230	our %PID_CB;	1596	our %PID_CB;
1231	our $CHLD_W;	1597	our $CHLD_W;
1232	our $CHLD_DELAY_W;	1598	our $CHLD_DELAY_W;
1233	our $WNOHANG;	1599	our $WNOHANG;
1234		1600
1235	sub _sigchld {	1601	# used by many Impl's
1236	while (0 < (my $pid = waitpid -1, $WNOHANG)) {	1602	sub _emit_childstatus($$) {
		1603	my (undef, $rpid, $rstatus) = @_;
		1604
		1605	$_->($rpid, $rstatus)
1237	$_->($pid, $?) for (values %{ $PID_CB{$pid} || {} }),	1606	for values %{ $PID_CB{$rpid} || {} },
1238	(values %{ $PID_CB{0} || {} });	1607	values %{ $PID_CB{0} || {} };
1239	}
1240	}	1608	}
1241		1609
1242	sub child {	1610	sub child {
		1611	eval q{ # poor man's autoloading {}
		1612	*_sigchld = sub {
		1613	my $pid;
		1614
		1615	AnyEvent->_emit_childstatus ($pid, $?)
		1616	while ($pid = waitpid -1, $WNOHANG) > 0;
		1617	};
		1618
		1619	*child = sub {
1243	my (undef, %arg) = @_;	1620	my (undef, %arg) = @_;
1244		1621
1245	defined (my $pid = $arg{pid} + 0)	1622	defined (my $pid = $arg{pid} + 0)
1246	or Carp::croak "required option 'pid' is missing";	1623	or Carp::croak "required option 'pid' is missing";
1247		1624
1248	$PID_CB{$pid}{$arg{cb}} = $arg{cb};	1625	$PID_CB{$pid}{$arg{cb}} = $arg{cb};
1249		1626
		1627	# WNOHANG is almost cetrainly 1 everywhere
		1628	$WNOHANG ||= $^O =~ /^(?:openbsd|netbsd|linux|freebsd|cygwin|MSWin32)$/
		1629	? 1
1250	$WNOHANG ||= eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1;	1630	: eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1;
1251		1631
1252	unless ($CHLD_W) {	1632	unless ($CHLD_W) {
1253	$CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld);	1633	$CHLD_W = AE::signal CHLD => \&_sigchld;
1254	# child could be a zombie already, so make at least one round	1634	# child could be a zombie already, so make at least one round
1255	&_sigchld;	1635	&_sigchld;
1256	}	1636	}
1257		1637
1258	bless [$pid, $arg{cb}], "AnyEvent::Base::child"	1638	bless [$pid, $arg{cb}], "AnyEvent::Base::child"
1259	}	1639	};
1260		1640
1261	sub AnyEvent::Base::child::DESTROY {	1641	*AnyEvent::Base::child::DESTROY = sub {
1262	my ($pid, $cb) = @{$_[0]};	1642	my ($pid, $cb) = @{$_[0]};
1263		1643
1264	delete $PID_CB{$pid}{$cb};	1644	delete $PID_CB{$pid}{$cb};
1265	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };	1645	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };
1266		1646
1267	undef $CHLD_W unless keys %PID_CB;	1647	undef $CHLD_W unless keys %PID_CB;
		1648	};
		1649	};
		1650	die if $@;
		1651
		1652	&child
1268	}	1653	}
1269		1654
1270	# idle emulation is done by simply using a timer, regardless	1655	# idle emulation is done by simply using a timer, regardless
1271	# of whether the process is idle or not, and not letting	1656	# of whether the process is idle or not, and not letting
1272	# the callback use more than 50% of the time.	1657	# the callback use more than 50% of the time.
1273	sub idle {	1658	sub idle {
		1659	eval q{ # poor man's autoloading {}
		1660	*idle = sub {
1274	my (undef, %arg) = @_;	1661	my (undef, %arg) = @_;
1275		1662
1276	my ($cb, $w, $rcb) = $arg{cb};	1663	my ($cb, $w, $rcb) = $arg{cb};
1277		1664
1278	$rcb = sub {	1665	$rcb = sub {
1279	if ($cb) {	1666	if ($cb) {
1280	$w = _time;	1667	$w = _time;
1281	&$cb;	1668	&$cb;
1282	$w = _time - $w;	1669	$w = _time - $w;
1283		1670
1284	# never use more then 50% of the time for the idle watcher,	1671	# never use more then 50% of the time for the idle watcher,
1285	# within some limits	1672	# within some limits
1286	$w = 0.0001 if $w < 0.0001;	1673	$w = 0.0001 if $w < 0.0001;
1287	$w = 5 if $w > 5;	1674	$w = 5 if $w > 5;
1288		1675
1289	$w = AnyEvent->timer (after => $w, cb => $rcb);	1676	$w = AE::timer $w, 0, $rcb;
1290	} else {	1677	} else {
1291	# clean up...	1678	# clean up...
1292	undef $w;	1679	undef $w;
1293	undef $rcb;	1680	undef $rcb;
		1681	}
		1682	};
		1683
		1684	$w = AE::timer 0.05, 0, $rcb;
		1685
		1686	bless \\$cb, "AnyEvent::Base::idle"
1294	}	1687	};
		1688
		1689	*AnyEvent::Base::idle::DESTROY = sub {
		1690	undef $${$_[0]};
		1691	};
1295	};	1692	};
		1693	die if $@;
1296		1694
1297	$w = AnyEvent->timer (after => 0.05, cb => $rcb);	1695	&idle
1298
1299	bless \\$cb, "AnyEvent::Base::idle"
1300	}
1301
1302	sub AnyEvent::Base::idle::DESTROY {
1303	undef $${$_[0]};
1304	}	1696	}
1305		1697
1306	package AnyEvent::CondVar;	1698	package AnyEvent::CondVar;
1307		1699
1308	our @ISA = AnyEvent::CondVar::Base::;	1700	our @ISA = AnyEvent::CondVar::Base::;
1309		1701
1310	package AnyEvent::CondVar::Base;	1702	package AnyEvent::CondVar::Base;
1311		1703
1312	use overload	1704	#use overload
1313	'&{}' => sub { my $self = shift; sub { $self->send (@_) } },	1705	# '&{}' => sub { my $self = shift; sub { $self->send (@_) } },
1314	fallback => 1;	1706	# fallback => 1;
		1707
		1708	# save 300+ kilobytes by dirtily hardcoding overloading
		1709	${"AnyEvent::CondVar::Base::OVERLOAD"}{dummy}++; # Register with magic by touching.
		1710	*{'AnyEvent::CondVar::Base::()'} = sub { }; # "Make it findable via fetchmethod."
		1711	*{'AnyEvent::CondVar::Base::(&{}'} = sub { my $self = shift; sub { $self->send (@_) } }; # &{}
		1712	${'AnyEvent::CondVar::Base::()'} = 1; # fallback
		1713
		1714	our $WAITING;
1315		1715
1316	sub _send {	1716	sub _send {
1317	# nop	1717	# nop
1318	}	1718	}
1319		1719
…		…
1332	sub ready {	1732	sub ready {
1333	$_[0]{_ae_sent}	1733	$_[0]{_ae_sent}
1334	}	1734	}
1335		1735
1336	sub _wait {	1736	sub _wait {
		1737	$WAITING
		1738	and !$_[0]{_ae_sent}
		1739	and Carp::croak "AnyEvent::CondVar: recursive blocking wait detected";
		1740
		1741	local $WAITING = 1;
1337	AnyEvent->one_event while !$_[0]{_ae_sent};	1742	AnyEvent->one_event while !$_[0]{_ae_sent};
1338	}	1743	}
1339		1744
1340	sub recv {	1745	sub recv {
1341	$_[0]->_wait;	1746	$_[0]->_wait;
…		…
1343	Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak};	1748	Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak};
1344	wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0]	1749	wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0]
1345	}	1750	}
1346		1751
1347	sub cb {	1752	sub cb {
1348	$_[0]{_ae_cb} = $_[1] if @_ > 1;	1753	my $cv = shift;
		1754
		1755	@_
		1756	and $cv->{_ae_cb} = shift
		1757	and $cv->{_ae_sent}
		1758	and (delete $cv->{_ae_cb})->($cv);
		1759
1349	$_[0]{_ae_cb}	1760	$cv->{_ae_cb}
1350	}	1761	}
1351		1762
1352	sub begin {	1763	sub begin {
1353	++$_[0]{_ae_counter};	1764	++$_[0]{_ae_counter};
1354	$_[0]{_ae_end_cb} = $_[1] if @_ > 1;	1765	$_[0]{_ae_end_cb} = $_[1] if @_ > 1;
…		…
1403	C<PERL_ANYEVENT_MODEL>.	1814	C<PERL_ANYEVENT_MODEL>.
1404		1815
1405	When set to C<2> or higher, cause AnyEvent to report to STDERR which event	1816	When set to C<2> or higher, cause AnyEvent to report to STDERR which event
1406	model it chooses.	1817	model it chooses.
1407		1818
		1819	When set to C<8> or higher, then AnyEvent will report extra information on
		1820	which optional modules it loads and how it implements certain features.
		1821
1408	=item C<PERL_ANYEVENT_STRICT>	1822	=item C<PERL_ANYEVENT_STRICT>
1409		1823
1410	AnyEvent does not do much argument checking by default, as thorough	1824	AnyEvent does not do much argument checking by default, as thorough
1411	argument checking is very costly. Setting this variable to a true value	1825	argument checking is very costly. Setting this variable to a true value
1412	will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly	1826	will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly
1413	check the arguments passed to most method calls. If it finds any problems,	1827	check the arguments passed to most method calls. If it finds any problems,
1414	it will croak.	1828	it will croak.
1415		1829
1416	In other words, enables "strict" mode.	1830	In other words, enables "strict" mode.
1417		1831
1418	Unlike C<use strict>, it is definitely recommended to keep it off in	1832	Unlike C<use strict> (or it's modern cousin, C<< use L<common::sense>
1419	production. Keeping C<PERL_ANYEVENT_STRICT=1> in your environment while	1833	>>, it is definitely recommended to keep it off in production. Keeping
1420	developing programs can be very useful, however.	1834	C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs
		1835	can be very useful, however.
1421		1836
1422	=item C<PERL_ANYEVENT_MODEL>	1837	=item C<PERL_ANYEVENT_MODEL>
1423		1838
1424	This can be used to specify the event model to be used by AnyEvent, before	1839	This can be used to specify the event model to be used by AnyEvent, before
1425	auto detection and -probing kicks in. It must be a string consisting	1840	auto detection and -probing kicks in. It must be a string consisting
…		…
1487		1902
1488	When neither C<ca_file> nor C<ca_path> was specified during	1903	When neither C<ca_file> nor C<ca_path> was specified during
1489	L<AnyEvent::TLS> context creation, and either of these environment	1904	L<AnyEvent::TLS> context creation, and either of these environment
1490	variables exist, they will be used to specify CA certificate locations	1905	variables exist, they will be used to specify CA certificate locations
1491	instead of a system-dependent default.	1906	instead of a system-dependent default.
		1907
		1908	=item C<PERL_ANYEVENT_AVOID_GUARD> and C<PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT>
		1909
		1910	When these are set to C<1>, then the respective modules are not
		1911	loaded. Mostly good for testing AnyEvent itself.
1492		1912
1493	=back	1913	=back
1494		1914
1495	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE	1915	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE
1496		1916
…		…
1554	warn "read: $input\n"; # output what has been read	1974	warn "read: $input\n"; # output what has been read
1555	$cv->send if $input =~ /^q/i; # quit program if /^q/i	1975	$cv->send if $input =~ /^q/i; # quit program if /^q/i
1556	},	1976	},
1557	);	1977	);
1558		1978
1559	my $time_watcher; # can only be used once
1560
1561	sub new_timer {
1562	$timer = AnyEvent->timer (after => 1, cb => sub {	1979	my $time_watcher = AnyEvent->timer (after => 1, interval => 1, cb => sub {
1563	warn "timeout\n"; # print 'timeout' about every second	1980	warn "timeout\n"; # print 'timeout' at most every second
1564	&new_timer; # and restart the time
1565	});	1981	});
1566	}
1567
1568	new_timer; # create first timer
1569		1982
1570	$cv->recv; # wait until user enters /^q/i	1983	$cv->recv; # wait until user enters /^q/i
1571		1984
1572	=head1 REAL-WORLD EXAMPLE	1985	=head1 REAL-WORLD EXAMPLE
1573		1986
…		…
1704	through AnyEvent. The benchmark creates a lot of timers (with a zero	2117	through AnyEvent. The benchmark creates a lot of timers (with a zero
1705	timeout) and I/O watchers (watching STDOUT, a pty, to become writable,	2118	timeout) and I/O watchers (watching STDOUT, a pty, to become writable,
1706	which it is), lets them fire exactly once and destroys them again.	2119	which it is), lets them fire exactly once and destroys them again.
1707		2120
1708	Source code for this benchmark is found as F<eg/bench> in the AnyEvent	2121	Source code for this benchmark is found as F<eg/bench> in the AnyEvent
1709	distribution.	2122	distribution. It uses the L<AE> interface, which makes a real difference
		2123	for the EV and Perl backends only.
1710		2124
1711	=head3 Explanation of the columns	2125	=head3 Explanation of the columns
1712		2126
1713	I<watcher> is the number of event watchers created/destroyed. Since	2127	I<watcher> is the number of event watchers created/destroyed. Since
1714	different event models feature vastly different performances, each event	2128	different event models feature vastly different performances, each event
…		…
1735	watcher.	2149	watcher.
1736		2150
1737	=head3 Results	2151	=head3 Results
1738		2152
1739	name watchers bytes create invoke destroy comment	2153	name watchers bytes create invoke destroy comment
1740	EV/EV 400000 224 0.47 0.35 0.27 EV native interface	2154	EV/EV 100000 223 0.47 0.43 0.27 EV native interface
1741	EV/Any 100000 224 2.88 0.34 0.27 EV + AnyEvent watchers	2155	EV/Any 100000 223 0.48 0.42 0.26 EV + AnyEvent watchers
1742	CoroEV/Any 100000 224 2.85 0.35 0.28 coroutines + Coro::Signal	2156	Coro::EV/Any 100000 223 0.47 0.42 0.26 coroutines + Coro::Signal
1743	Perl/Any 100000 452 4.13 0.73 0.95 pure perl implementation	2157	Perl/Any 100000 431 2.70 0.74 0.92 pure perl implementation
1744	Event/Event 16000 517 32.20 31.80 0.81 Event native interface	2158	Event/Event 16000 516 31.16 31.84 0.82 Event native interface
1745	Event/Any 16000 590 35.85 31.55 1.06 Event + AnyEvent watchers	2159	Event/Any 16000 1203 42.61 34.79 1.80 Event + AnyEvent watchers
1746	IOAsync/Any 16000 989 38.10 32.77 11.13 via IO::Async::Loop::IO_Poll	2160	IOAsync/Any 16000 1911 41.92 27.45 16.81 via IO::Async::Loop::IO_Poll
1747	IOAsync/Any 16000 990 37.59 29.50 10.61 via IO::Async::Loop::Epoll	2161	IOAsync/Any 16000 1726 40.69 26.37 15.25 via IO::Async::Loop::Epoll
1748	Glib/Any 16000 1357 102.33 12.31 51.00 quadratic behaviour	2162	Glib/Any 16000 1118 89.00 12.57 51.17 quadratic behaviour
1749	Tk/Any 2000 1860 27.20 66.31 14.00 SEGV with >> 2000 watchers	2163	Tk/Any 2000 1346 20.96 10.75 8.00 SEGV with >> 2000 watchers
1750	POE/Event 2000 6328 109.99 751.67 14.02 via POE::Loop::Event	2164	POE/Any 2000 6951 108.97 795.32 14.24 via POE::Loop::Event
1751	POE/Select 2000 6027 94.54 809.13 579.80 via POE::Loop::Select	2165	POE/Any 2000 6648 94.79 774.40 575.51 via POE::Loop::Select
1752		2166
1753	=head3 Discussion	2167	=head3 Discussion
1754		2168
1755	The benchmark does I<not> measure scalability of the event loop very	2169	The benchmark does I<not> measure scalability of the event loop very
1756	well. For example, a select-based event loop (such as the pure perl one)	2170	well. For example, a select-based event loop (such as the pure perl one)
…		…
1768	benchmark machine, handling an event takes roughly 1600 CPU cycles with	2182	benchmark machine, handling an event takes roughly 1600 CPU cycles with
1769	EV, 3100 CPU cycles with AnyEvent's pure perl loop and almost 3000000 CPU	2183	EV, 3100 CPU cycles with AnyEvent's pure perl loop and almost 3000000 CPU
1770	cycles with POE.	2184	cycles with POE.
1771		2185
1772	C<EV> is the sole leader regarding speed and memory use, which are both	2186	C<EV> is the sole leader regarding speed and memory use, which are both
1773	maximal/minimal, respectively. Even when going through AnyEvent, it uses	2187	maximal/minimal, respectively. When using the L<AE> API there is zero
		2188	overhead (when going through the AnyEvent API create is about 5-6 times
		2189	slower, with other times being equal, so still uses far less memory than
1774	far less memory than any other event loop and is still faster than Event	2190	any other event loop and is still faster than Event natively).
1775	natively.
1776		2191
1777	The pure perl implementation is hit in a few sweet spots (both the	2192	The pure perl implementation is hit in a few sweet spots (both the
1778	constant timeout and the use of a single fd hit optimisations in the perl	2193	constant timeout and the use of a single fd hit optimisations in the perl
1779	interpreter and the backend itself). Nevertheless this shows that it	2194	interpreter and the backend itself). Nevertheless this shows that it
1780	adds very little overhead in itself. Like any select-based backend its	2195	adds very little overhead in itself. Like any select-based backend its
…		…
1854	In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100	2269	In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100
1855	(1%) are active. This mirrors the activity of large servers with many	2270	(1%) are active. This mirrors the activity of large servers with many
1856	connections, most of which are idle at any one point in time.	2271	connections, most of which are idle at any one point in time.
1857		2272
1858	Source code for this benchmark is found as F<eg/bench2> in the AnyEvent	2273	Source code for this benchmark is found as F<eg/bench2> in the AnyEvent
1859	distribution.	2274	distribution. It uses the L<AE> interface, which makes a real difference
		2275	for the EV and Perl backends only.
1860		2276
1861	=head3 Explanation of the columns	2277	=head3 Explanation of the columns
1862		2278
1863	I<sockets> is the number of sockets, and twice the number of "servers" (as	2279	I<sockets> is the number of sockets, and twice the number of "servers" (as
1864	each server has a read and write socket end).	2280	each server has a read and write socket end).
…		…
1872	a new one that moves the timeout into the future.	2288	a new one that moves the timeout into the future.
1873		2289
1874	=head3 Results	2290	=head3 Results
1875		2291
1876	name sockets create request	2292	name sockets create request
1877	EV 20000 69.01 11.16	2293	EV 20000 62.66 7.99
1878	Perl 20000 73.32 35.87	2294	Perl 20000 68.32 32.64
1879	IOAsync 20000 157.00 98.14 epoll	2295	IOAsync 20000 174.06 101.15 epoll
1880	IOAsync 20000 159.31 616.06 poll	2296	IOAsync 20000 174.67 610.84 poll
1881	Event 20000 212.62 257.32	2297	Event 20000 202.69 242.91
1882	Glib 20000 651.16 1896.30	2298	Glib 20000 557.01 1689.52
1883	POE 20000 349.67 12317.24 uses POE::Loop::Event	2299	POE 20000 341.54 12086.32 uses POE::Loop::Event
1884		2300
1885	=head3 Discussion	2301	=head3 Discussion
1886		2302
1887	This benchmark I<does> measure scalability and overall performance of the	2303	This benchmark I<does> measure scalability and overall performance of the
1888	particular event loop.	2304	particular event loop.
…		…
2014	As you can see, the AnyEvent + EV combination even beats the	2430	As you can see, the AnyEvent + EV combination even beats the
2015	hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl	2431	hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl
2016	backend easily beats IO::Lambda and POE.	2432	backend easily beats IO::Lambda and POE.
2017		2433
2018	And even the 100% non-blocking version written using the high-level (and	2434	And even the 100% non-blocking version written using the high-level (and
2019	slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda by a	2435	slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda
2020	large margin, even though it does all of DNS, tcp-connect and socket I/O	2436	higher level ("unoptimised") abstractions by a large margin, even though
2021	in a non-blocking way.	2437	it does all of DNS, tcp-connect and socket I/O in a non-blocking way.
2022		2438
2023	The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and	2439	The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and
2024	F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are	2440	F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are
2025	part of the IO::lambda distribution and were used without any changes.	2441	part of the IO::Lambda distribution and were used without any changes.
2026		2442
2027		2443
2028	=head1 SIGNALS	2444	=head1 SIGNALS
2029		2445
2030	AnyEvent currently installs handlers for these signals:	2446	AnyEvent currently installs handlers for these signals:
…		…
2035		2451
2036	A handler for C<SIGCHLD> is installed by AnyEvent's child watcher	2452	A handler for C<SIGCHLD> is installed by AnyEvent's child watcher
2037	emulation for event loops that do not support them natively. Also, some	2453	emulation for event loops that do not support them natively. Also, some
2038	event loops install a similar handler.	2454	event loops install a similar handler.
2039		2455
2040	If, when AnyEvent is loaded, SIGCHLD is set to IGNORE, then AnyEvent will	2456	Additionally, when AnyEvent is loaded and SIGCHLD is set to IGNORE, then
2041	reset it to default, to avoid losing child exit statuses.	2457	AnyEvent will reset it to default, to avoid losing child exit statuses.
2042		2458
2043	=item SIGPIPE	2459	=item SIGPIPE
2044		2460
2045	A no-op handler is installed for C<SIGPIPE> when C<$SIG{PIPE}> is C<undef>	2461	A no-op handler is installed for C<SIGPIPE> when C<$SIG{PIPE}> is C<undef>
2046	when AnyEvent gets loaded.	2462	when AnyEvent gets loaded.
…		…
2064	if $SIG{CHLD} eq 'IGNORE';	2480	if $SIG{CHLD} eq 'IGNORE';
2065		2481
2066	$SIG{PIPE} = sub { }	2482	$SIG{PIPE} = sub { }
2067	unless defined $SIG{PIPE};	2483	unless defined $SIG{PIPE};
2068		2484
		2485	=head1 RECOMMENDED/OPTIONAL MODULES
		2486
		2487	One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and
		2488	it's built-in modules) are required to use it.
		2489
		2490	That does not mean that AnyEvent won't take advantage of some additional
		2491	modules if they are installed.
		2492
		2493	This section explains which additional modules will be used, and how they
		2494	affect AnyEvent's operation.
		2495
		2496	=over 4
		2497
		2498	=item L<Async::Interrupt>
		2499
		2500	This slightly arcane module is used to implement fast signal handling: To
		2501	my knowledge, there is no way to do completely race-free and quick
		2502	signal handling in pure perl. To ensure that signals still get
		2503	delivered, AnyEvent will start an interval timer to wake up perl (and
		2504	catch the signals) with some delay (default is 10 seconds, look for
		2505	C<$AnyEvent::MAX_SIGNAL_LATENCY>).
		2506
		2507	If this module is available, then it will be used to implement signal
		2508	catching, which means that signals will not be delayed, and the event loop
		2509	will not be interrupted regularly, which is more efficient (and good for
		2510	battery life on laptops).
		2511
		2512	This affects not just the pure-perl event loop, but also other event loops
		2513	that have no signal handling on their own (e.g. Glib, Tk, Qt).
		2514
		2515	Some event loops (POE, Event, Event::Lib) offer signal watchers natively,
		2516	and either employ their own workarounds (POE) or use AnyEvent's workaround
		2517	(using C<$AnyEvent::MAX_SIGNAL_LATENCY>). Installing L<Async::Interrupt>
		2518	does nothing for those backends.
		2519
		2520	=item L<EV>
		2521
		2522	This module isn't really "optional", as it is simply one of the backend
		2523	event loops that AnyEvent can use. However, it is simply the best event
		2524	loop available in terms of features, speed and stability: It supports
		2525	the AnyEvent API optimally, implements all the watcher types in XS, does
		2526	automatic timer adjustments even when no monotonic clock is available,
		2527	can take avdantage of advanced kernel interfaces such as C<epoll> and
		2528	C<kqueue>, and is the fastest backend I<by far>. You can even embed
		2529	L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>).
		2530
		2531	=item L<Guard>
		2532
		2533	The guard module, when used, will be used to implement
		2534	C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a
		2535	lot less memory), but otherwise doesn't affect guard operation much. It is
		2536	purely used for performance.
		2537
		2538	=item L<JSON> and L<JSON::XS>
		2539
		2540	One of these modules is required when you want to read or write JSON data
		2541	via L<AnyEvent::Handle>. It is also written in pure-perl, but can take
		2542	advantage of the ultra-high-speed L<JSON::XS> module when it is installed.
		2543
		2544	In fact, L<AnyEvent::Handle> will use L<JSON::XS> by default if it is
		2545	installed.
		2546
		2547	=item L<Net::SSLeay>
		2548
		2549	Implementing TLS/SSL in Perl is certainly interesting, but not very
		2550	worthwhile: If this module is installed, then L<AnyEvent::Handle> (with
		2551	the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL.
		2552
		2553	=item L<Time::HiRes>
		2554
		2555	This module is part of perl since release 5.008. It will be used when the
		2556	chosen event library does not come with a timing source on it's own. The
		2557	pure-perl event loop (L<AnyEvent::Impl::Perl>) will additionally use it to
		2558	try to use a monotonic clock for timing stability.
		2559
		2560	=back
		2561
		2562
2069	=head1 FORK	2563	=head1 FORK
2070		2564
2071	Most event libraries are not fork-safe. The ones who are usually are	2565	Most event libraries are not fork-safe. The ones who are usually are
2072	because they rely on inefficient but fork-safe C<select> or C<poll>	2566	because they rely on inefficient but fork-safe C<select> or C<poll> calls
2073	calls. Only L<EV> is fully fork-aware.	2567	- higher performance APIs such as BSD's kqueue or the dreaded Linux epoll
		2568	are usually badly thought-out hacks that are incompatible with fork in
		2569	one way or another. Only L<EV> is fully fork-aware and ensures that you
		2570	continue event-processing in both parent and child (or both, if you know
		2571	what you are doing).
		2572
		2573	This means that, in general, you cannot fork and do event processing in
		2574	the child if the event library was initialised before the fork (which
		2575	usually happens when the first AnyEvent watcher is created, or the library
		2576	is loaded).
2074		2577
2075	If you have to fork, you must either do so I<before> creating your first	2578	If you have to fork, you must either do so I<before> creating your first
2076	watcher OR you must not use AnyEvent at all in the child.	2579	watcher OR you must not use AnyEvent at all in the child OR you must do
		2580	something completely out of the scope of AnyEvent.
		2581
		2582	The problem of doing event processing in the parent I<and> the child
		2583	is much more complicated: even for backends that I<are> fork-aware or
		2584	fork-safe, their behaviour is not usually what you want: fork clones all
		2585	watchers, that means all timers, I/O watchers etc. are active in both
		2586	parent and child, which is almost never what you want. USing C<exec>
		2587	to start worker children from some kind of manage rprocess is usually
		2588	preferred, because it is much easier and cleaner, at the expense of having
		2589	to have another binary.
2077		2590
2078		2591
2079	=head1 SECURITY CONSIDERATIONS	2592	=head1 SECURITY CONSIDERATIONS
2080		2593
2081	AnyEvent can be forced to load any event model via	2594	AnyEvent can be forced to load any event model via
…		…
2119	L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.	2632	L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.
2120		2633
2121	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,	2634	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,
2122	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,	2635	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,
2123	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,	2636	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,
2124	L<AnyEvent::Impl::POE>.	2637	L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>, L<Anyevent::Impl::Irssi>.
2125		2638
2126	Non-blocking file handles, sockets, TCP clients and	2639	Non-blocking file handles, sockets, TCP clients and
2127	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>.	2640	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.
2128		2641
2129	Asynchronous DNS: L<AnyEvent::DNS>.	2642	Asynchronous DNS: L<AnyEvent::DNS>.
2130		2643
2131	Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>,	2644	Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>,
		2645	L<Coro::Event>,
2132		2646
2133	Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>, L<AnyEvent::DNS>.	2647	Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::XMPP>,
		2648	L<AnyEvent::HTTP>.
2134		2649
2135		2650
2136	=head1 AUTHOR	2651	=head1 AUTHOR
2137		2652
2138	Marc Lehmann <schmorp@schmorp.de>	2653	Marc Lehmann <schmorp@schmorp.de>

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