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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
745	=head1 SUPPORTED EVENT LOOPS/BACKENDS	830	=head1 SUPPORTED EVENT LOOPS/BACKENDS
746		831
…		…
749	=over 4	834	=over 4
750		835
751	=item Backends that are autoprobed when no other event loop can be found.	836	=item Backends that are autoprobed when no other event loop can be found.
752		837
753	EV is the preferred backend when no other event loop seems to be in	838	EV is the preferred backend when no other event loop seems to be in
754	use. If EV is not installed, then AnyEvent will try Event, and, failing	839	use. If EV is not installed, then AnyEvent will fall back to its own
755	that, will fall back to its own pure-perl implementation, which is	840	pure-perl implementation, which is available everywhere as it comes with
756	available everywhere as it comes with AnyEvent itself.	841	AnyEvent itself.
757		842
758	AnyEvent::Impl::EV based on EV (interface to libev, best choice).	843	AnyEvent::Impl::EV based on EV (interface to libev, best choice).
759	AnyEvent::Impl::Event based on Event, very stable, few glitches.
760	AnyEvent::Impl::Perl pure-perl implementation, fast and portable.	844	AnyEvent::Impl::Perl pure-perl implementation, fast and portable.
761		845
762	=item Backends that are transparently being picked up when they are used.	846	=item Backends that are transparently being picked up when they are used.
763		847
764	These will be used when they are currently loaded when the first watcher	848	These will be used when they are currently loaded when the first watcher
765	is created, in which case it is assumed that the application is using	849	is created, in which case it is assumed that the application is using
766	them. This means that AnyEvent will automatically pick the right backend	850	them. This means that AnyEvent will automatically pick the right backend
767	when the main program loads an event module before anything starts to	851	when the main program loads an event module before anything starts to
768	create watchers. Nothing special needs to be done by the main program.	852	create watchers. Nothing special needs to be done by the main program.
769		853
		854	AnyEvent::Impl::Event based on Event, very stable, few glitches.
770	AnyEvent::Impl::Glib based on Glib, slow but very stable.	855	AnyEvent::Impl::Glib based on Glib, slow but very stable.
771	AnyEvent::Impl::Tk based on Tk, very broken.	856	AnyEvent::Impl::Tk based on Tk, very broken.
772	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.	857	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
773	AnyEvent::Impl::POE based on POE, very slow, some limitations.	858	AnyEvent::Impl::POE based on POE, very slow, some limitations.
		859	AnyEvent::Impl::Irssi used when running within irssi.
774		860
775	=item Backends with special needs.	861	=item Backends with special needs.
776		862
777	Qt requires the Qt::Application to be instantiated first, but will	863	Qt requires the Qt::Application to be instantiated first, but will
778	otherwise be picked up automatically. As long as the main program	864	otherwise be picked up automatically. As long as the main program
…		…
852	event module detection too early, for example, L<AnyEvent::AIO> creates	938	event module detection too early, for example, L<AnyEvent::AIO> creates
853	and installs the global L<IO::AIO> watcher in a C<post_detect> block to	939	and installs the global L<IO::AIO> watcher in a C<post_detect> block to
854	avoid autodetecting the event module at load time.	940	avoid autodetecting the event module at load time.
855		941
856	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
857	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
858	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 ||= $guard;
859		962
860	=item @AnyEvent::post_detect	963	=item @AnyEvent::post_detect
861		964
862	If there are any code references in this array (you can C<push> to it	965	If there are any code references in this array (you can C<push> to it
863	before or after loading AnyEvent), then they will called directly after	966	before or after loading AnyEvent), then they will called directly after
…		…
866	You should check C<$AnyEvent::MODEL> before adding to this array, though:	969	You should check C<$AnyEvent::MODEL> before adding to this array, though:
867	if it is defined then the event loop has already been detected, and the	970	if it is defined then the event loop has already been detected, and the
868	array will be ignored.	971	array will be ignored.
869		972
870	Best use C<AnyEvent::post_detect { BLOCK }> when your application allows	973	Best use C<AnyEvent::post_detect { BLOCK }> when your application allows
871	it,as it takes care of these details.	974	it, as it takes care of these details.
872		975
873	This variable is mainly useful for modules that can do something useful	976	This variable is mainly useful for modules that can do something useful
874	when AnyEvent is used and thus want to know when it is initialised, but do	977	when AnyEvent is used and thus want to know when it is initialised, but do
875	not need to even load it by default. This array provides the means to hook	978	not need to even load it by default. This array provides the means to hook
876	into AnyEvent passively, without loading it.	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	}
877		993
878	=back	994	=back
879		995
880	=head1 WHAT TO DO IN A MODULE	996	=head1 WHAT TO DO IN A MODULE
881		997
…		…
1028		1144
1029	=cut	1145	=cut
1030		1146
1031	package AnyEvent;	1147	package AnyEvent;
1032		1148
1033	no warnings;	1149	# basically a tuned-down version of common::sense
1034	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	}
1035		1156
		1157	BEGIN { AnyEvent::common_sense }
		1158
1036	use Carp;	1159	use Carp ();
1037		1160
1038	our $VERSION = 4.82;	1161	our $VERSION = '5.24';
1039	our $MODEL;	1162	our $MODEL;
1040		1163
1041	our $AUTOLOAD;	1164	our $AUTOLOAD;
1042	our @ISA;	1165	our @ISA;
1043		1166
1044	our @REGISTRY;	1167	our @REGISTRY;
1045		1168
1046	our $WIN32;	1169	our $VERBOSE;
1047		1170
1048	BEGIN {	1171	BEGIN {
		1172	eval "sub CYGWIN(){" . (($^O =~ /cygwin/i) *1) . "}";
1049	eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }";	1173	eval "sub WIN32 (){" . (($^O =~ /mswin32/i)*1) . "}";
1050	eval "sub TAINT(){ " . (${^TAINT}*1) . " }";	1174	eval "sub TAINT (){" . (${^TAINT} *1) . "}";
1051		1175
1052	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}	1176	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}
1053	if ${^TAINT};	1177	if ${^TAINT};
1054	}
1055		1178
1056	our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1;	1179	$VERBOSE = $ENV{PERL_ANYEVENT_VERBOSE}*1;
		1180
		1181	}
		1182
		1183	our $MAX_SIGNAL_LATENCY = 10;
1057		1184
1058	our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred	1185	our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred
1059		1186
1060	{	1187	{
1061	my $idx;	1188	my $idx;
…		…
1063	for reverse split /\s*,\s*/,	1190	for reverse split /\s*,\s*/,
1064	$ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";	1191	$ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";
1065	}	1192	}
1066		1193
1067	my @models = (	1194	my @models = (
1068	[EV:: => AnyEvent::Impl::EV::],	1195	[EV:: => AnyEvent::Impl::EV:: , 1],
1069	[Event:: => AnyEvent::Impl::Event::],
1070	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::],	1196	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl:: , 1],
1071	# everything below here will not be autoprobed	1197	# everything below here will not (normally) be autoprobed
1072	# as the pureperl backend should work everywhere	1198	# as the pureperl backend should work everywhere
1073	# and is usually faster	1199	# and is usually faster
		1200	[Event:: => AnyEvent::Impl::Event::, 1],
1074	[Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers	1201	[Glib:: => AnyEvent::Impl::Glib:: , 1], # becomes extremely slow with many watchers
1075	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy	1202	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
		1203	[Irssi:: => AnyEvent::Impl::Irssi::], # Irssi has a bogus "Event" package
1076	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles	1204	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
1077	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program	1205	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program
1078	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza	1206	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
1079	[Wx:: => AnyEvent::Impl::POE::],	1207	[Wx:: => AnyEvent::Impl::POE::],
1080	[Prima:: => AnyEvent::Impl::POE::],	1208	[Prima:: => AnyEvent::Impl::POE::],
1081	# IO::Async is just too broken - we would need workarounds for its	1209	# IO::Async is just too broken - we would need workarounds for its
1082	# byzantine signal and broken child handling, among others.	1210	# byzantine signal and broken child handling, among others.
1083	# 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
1084	# obvious default class.	1212	# obvious default class.
1085	# [IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program	1213	[IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program
1086	# [IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program	1214	[IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program
1087	# [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
1088	);	1217	);
1089		1218
1090	our %method = map +($_ => 1),	1219	our %method = map +($_ => 1),
1091	qw(io timer time now now_update signal child idle condvar one_event DESTROY);	1220	qw(io timer time now now_update signal child idle condvar one_event DESTROY);
1092		1221
…		…
1096	my ($cb) = @_;	1225	my ($cb) = @_;
1097		1226
1098	if ($MODEL) {	1227	if ($MODEL) {
1099	$cb->();	1228	$cb->();
1100		1229
1101	1	1230	undef
1102	} else {	1231	} else {
1103	push @post_detect, $cb;	1232	push @post_detect, $cb;
1104		1233
1105	defined wantarray	1234	defined wantarray
1106	? bless \$cb, "AnyEvent::Util::postdetect"	1235	? bless \$cb, "AnyEvent::Util::postdetect"
…		…
1111	sub AnyEvent::Util::postdetect::DESTROY {	1240	sub AnyEvent::Util::postdetect::DESTROY {
1112	@post_detect = grep $_ != ${$_[0]}, @post_detect;	1241	@post_detect = grep $_ != ${$_[0]}, @post_detect;
1113	}	1242	}
1114		1243
1115	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 $VERBOSE;
		1258	}
		1259	}
		1260
		1261	# check for already loaded models
1116	unless ($MODEL) {	1262	unless ($MODEL) {
1117	no strict 'refs';	1263	for (@REGISTRY, @models) {
1118	local $SIG{__DIE__};	1264	my ($package, $model) = @$_;
1119		1265	if (${"$package\::VERSION"} > 0) {
1120	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {
1121	my $model = "AnyEvent::Impl::$1";
1122	if (eval "require $model") {	1266	if (eval "require $model") {
1123	$MODEL = $model;	1267	$MODEL = $model;
1124	warn "AnyEvent: loaded model '$model' (forced by \$PERL_ANYEVENT_MODEL), using it.\n" if $verbose > 1;	1268	warn "AnyEvent: autodetected model '$model', using it.\n" if $VERBOSE >= 2;
1125	} else {	1269	last;
1126	warn "AnyEvent: unable to load model '$model' (from \$PERL_ANYEVENT_MODEL):\n$@" if $verbose;	1270	}
1127	}	1271	}
1128	}	1272	}
1129		1273
1130	# check for already loaded models
1131	unless ($MODEL) {	1274	unless ($MODEL) {
		1275	# try to autoload a model
1132	for (@REGISTRY, @models) {	1276	for (@REGISTRY, @models) {
1133	my ($package, $model) = @$_;	1277	my ($package, $model, $autoload) = @$_;
		1278	if (
		1279	$autoload
		1280	and eval "require $package"
1134	if (${"$package\::VERSION"} > 0) {	1281	and ${"$package\::VERSION"} > 0
1135	if (eval "require $model") {	1282	and eval "require $model"
		1283	) {
1136	$MODEL = $model;	1284	$MODEL = $model;
1137	warn "AnyEvent: autodetected model '$model', using it.\n" if $verbose > 1;	1285	warn "AnyEvent: autoloaded model '$model', using it.\n" if $VERBOSE >= 2;
1138	last;	1286	last;
1139	}
1140	}	1287	}
1141	}	1288	}
1142		1289
1143	unless ($MODEL) {
1144	# try to load a model
1145
1146	for (@REGISTRY, @models) {
1147	my ($package, $model) = @$_;
1148	if (eval "require $package"
1149	and ${"$package\::VERSION"} > 0
1150	and eval "require $model") {
1151	$MODEL = $model;
1152	warn "AnyEvent: autoprobed model '$model', using it.\n" if $verbose > 1;
1153	last;
1154	}
1155	}
1156
1157	$MODEL	1290	$MODEL
1158	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.\n";	1291	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.\n";
1159	}
1160	}	1292	}
1161
1162	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
1163
1164	unshift @ISA, $MODEL;
1165
1166	require AnyEvent::Strict if $ENV{PERL_ANYEVENT_STRICT};
1167
1168	(shift @post_detect)->() while @post_detect;
1169	}	1293	}
		1294
		1295	@models = (); # free probe data
		1296
		1297	push @{"$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;
1170		1303
1171	$MODEL	1304	$MODEL
1172	}	1305	}
1173		1306
1174	sub AUTOLOAD {	1307	sub AUTOLOAD {
1175	(my $func = $AUTOLOAD) =~ s/.*://;	1308	(my $func = $AUTOLOAD) =~ s/.*://;
1176		1309
1177	$method{$func}	1310	$method{$func}
1178	or croak "$func: not a valid method for AnyEvent objects";	1311	or Carp::croak "$func: not a valid AnyEvent class method";
1179		1312
1180	detect unless $MODEL;	1313	detect;
1181		1314
1182	my $class = shift;	1315	my $class = shift;
1183	$class->$func (@_);	1316	$class->$func (@_);
1184	}	1317	}
1185		1318
…		…
1188	# 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).
1189	sub _dupfh($$;$$) {	1322	sub _dupfh($$;$$) {
1190	my ($poll, $fh, $r, $w) = @_;	1323	my ($poll, $fh, $r, $w) = @_;
1191		1324
1192	# cygwin requires the fh mode to be matching, unix doesn't	1325	# cygwin requires the fh mode to be matching, unix doesn't
1193	my ($rw, $mode) = $poll eq "r" ? ($r, "<") : ($w, ">");	1326	my ($rw, $mode) = $poll eq "r" ? ($r, "<&") : ($w, ">&");
1194		1327
1195	open my $fh2, "$mode&", $fh	1328	open my $fh2, $mode, $fh
1196	or die "AnyEvent->io: cannot dup() filehandle in mode '$poll': $!,";	1329	or die "AnyEvent->io: cannot dup() filehandle in mode '$poll': $!,";
1197		1330
1198	# we assume CLOEXEC is already set by perl in all important cases	1331	# we assume CLOEXEC is already set by perl in all important cases
1199		1332
1200	($fh2, $rw)	1333	($fh2, $rw)
1201	}	1334	}
1202		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
1203	package AnyEvent::Base;	1386	package AnyEvent::Base;
1204		1387
1205	# default implementations for many methods	1388	# default implementations for many methods
1206		1389
1207	BEGIN {	1390	sub _time() {
		1391	eval q{ # poor man's autoloading
		1392	# probe for availability of Time::HiRes
1208	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;
1209	*_time = \&Time::HiRes::time;	1395	*_time = \&Time::HiRes::time;
1210	# if (eval "use POSIX (); (POSIX::times())...	1396	# if (eval "use POSIX (); (POSIX::times())...
1211	} else {	1397	} else {
		1398	warn "AnyEvent: using built-in time(), WARNING, no sub-second resolution!\n" if $VERBOSE;
1212	*_time = sub { time }; # epic fail	1399	*_time = sub (){ time }; # epic fail
		1400	}
1213	}	1401	};
		1402	die if $@;
		1403
		1404	&_time
1214	}	1405	}
1215		1406
1216	sub time { _time }	1407	sub time { _time }
1217	sub now { _time }	1408	sub now { _time }
1218	sub now_update { }	1409	sub now_update { }
…		…
1223	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"	1414	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"
1224	}	1415	}
1225		1416
1226	# default implementation for ->signal	1417	# default implementation for ->signal
1227		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	$HAVE_ASYNC_INTERRUPT
		1427	}
		1428
1228	our ($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);
1229		1432
1230	sub _signal_exec {	1433	# install a dummy wakeup watcher to reduce signal catching latency
1231	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;
1232		1439
1233	while (%SIG_EV) {	1440	$SIG_TW = AE::timer
1234	for (keys %SIG_EV) {	1441	$MAX_SIGNAL_LATENCY - ($NOW - int $NOW),
1235	delete $SIG_EV{$_};	1442	$MAX_SIGNAL_LATENCY,
1236	$_->() 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	};
1237	}	1476	}
1238	}	1477	};
1239	}	1478	die if $@;
		1479	};
		1480
		1481	sub sig2num ($) { &$_sig_name_init; &sig2num }
		1482	sub sig2name($) { &$_sig_name_init; &sig2name }
1240		1483
1241	sub signal {	1484	sub signal {
1242	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 $VERBOSE >= 8;
1243		1489
1244	unless ($SIGPIPE_R) {	1490	$SIGPIPE_R = new Async::Interrupt::EventPipe;
1245	require Fcntl;	1491	$SIG_IO = AE::io $SIGPIPE_R->fileno, 0, \&_signal_exec;
1246		1492
1247	if (AnyEvent::WIN32) {
1248	require AnyEvent::Util;
1249
1250	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
1251	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R) if $SIGPIPE_R;
1252	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W) if $SIGPIPE_W; # just in case
1253	} 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 {
1254	pipe $SIGPIPE_R, $SIGPIPE_W;	1505	pipe $SIGPIPE_R, $SIGPIPE_W;
1255	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;
1256	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
1257		1508
1258	# 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...
1259	fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;	1510	fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
1260	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;
1261	}	1518	}
1262		1519
1263	$SIGPIPE_R	1520	*signal = sub {
1264	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";	1521	my (undef, %arg) = @_;
1265		1522
1266	$SIG_IO = AnyEvent->io (fh => $SIGPIPE_R, poll => "r", cb => \&_signal_exec);
1267	}
1268
1269	my $signal = uc $arg{signal}	1523	my $signal = uc $arg{signal}
1270	or Carp::croak "required option 'signal' is missing";	1524	or Carp::croak "required option 'signal' is missing";
1271		1525
		1526	if ($HAVE_ASYNC_INTERRUPT) {
		1527	# async::interrupt
		1528
		1529	$signal = sig2num $signal;
1272	$SIG_CB{$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
1273	$SIG{$signal} ||= sub {	1546	$SIG{$signal} ||= sub {
1274	local $!;	1547	local $!;
1275	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;	1548	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;
1276	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	};
1277	};	1588	};
		1589	die if $@;
1278		1590
1279	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"	1591	&signal
1280	}
1281
1282	sub AnyEvent::Base::signal::DESTROY {
1283	my ($signal, $cb) = @{$_[0]};
1284
1285	delete $SIG_CB{$signal}{$cb};
1286
1287	# delete doesn't work with older perls - they then
1288	# print weird messages, or just unconditionally exit
1289	# instead of getting the default action.
1290	undef $SIG{$signal} unless keys %{ $SIG_CB{$signal} };
1291	}	1592	}
1292		1593
1293	# default implementation for ->child	1594	# default implementation for ->child
1294		1595
1295	our %PID_CB;	1596	our %PID_CB;
1296	our $CHLD_W;	1597	our $CHLD_W;
1297	our $CHLD_DELAY_W;	1598	our $CHLD_DELAY_W;
1298	our $WNOHANG;	1599	our $WNOHANG;
1299		1600
1300	sub _sigchld {	1601	# used by many Impl's
1301	while (0 < (my $pid = waitpid -1, $WNOHANG)) {	1602	sub _emit_childstatus($$) {
		1603	my (undef, $rpid, $rstatus) = @_;
		1604
		1605	$_->($rpid, $rstatus)
1302	$_->($pid, $?) for (values %{ $PID_CB{$pid} || {} }),	1606	for values %{ $PID_CB{$rpid} || {} },
1303	(values %{ $PID_CB{0} || {} });	1607	values %{ $PID_CB{0} || {} };
1304	}
1305	}	1608	}
1306		1609
1307	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 {
1308	my (undef, %arg) = @_;	1620	my (undef, %arg) = @_;
1309		1621
1310	defined (my $pid = $arg{pid} + 0)	1622	defined (my $pid = $arg{pid} + 0)
1311	or Carp::croak "required option 'pid' is missing";	1623	or Carp::croak "required option 'pid' is missing";
1312		1624
1313	$PID_CB{$pid}{$arg{cb}} = $arg{cb};	1625	$PID_CB{$pid}{$arg{cb}} = $arg{cb};
1314		1626
		1627	# WNOHANG is almost cetrainly 1 everywhere
		1628	$WNOHANG ||= $^O =~ /^(?:openbsd|netbsd|linux|freebsd|cygwin|MSWin32)$/
		1629	? 1
1315	$WNOHANG ||= eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1;	1630	: eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1;
1316		1631
1317	unless ($CHLD_W) {	1632	unless ($CHLD_W) {
1318	$CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld);	1633	$CHLD_W = AE::signal CHLD => \&_sigchld;
1319	# 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
1320	&_sigchld;	1635	&_sigchld;
1321	}	1636	}
1322		1637
1323	bless [$pid, $arg{cb}], "AnyEvent::Base::child"	1638	bless [$pid, $arg{cb}], "AnyEvent::Base::child"
1324	}	1639	};
1325		1640
1326	sub AnyEvent::Base::child::DESTROY {	1641	*AnyEvent::Base::child::DESTROY = sub {
1327	my ($pid, $cb) = @{$_[0]};	1642	my ($pid, $cb) = @{$_[0]};
1328		1643
1329	delete $PID_CB{$pid}{$cb};	1644	delete $PID_CB{$pid}{$cb};
1330	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };	1645	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };
1331		1646
1332	undef $CHLD_W unless keys %PID_CB;	1647	undef $CHLD_W unless keys %PID_CB;
		1648	};
		1649	};
		1650	die if $@;
		1651
		1652	&child
1333	}	1653	}
1334		1654
1335	# idle emulation is done by simply using a timer, regardless	1655	# idle emulation is done by simply using a timer, regardless
1336	# of whether the process is idle or not, and not letting	1656	# of whether the process is idle or not, and not letting
1337	# the callback use more than 50% of the time.	1657	# the callback use more than 50% of the time.
1338	sub idle {	1658	sub idle {
		1659	eval q{ # poor man's autoloading {}
		1660	*idle = sub {
1339	my (undef, %arg) = @_;	1661	my (undef, %arg) = @_;
1340		1662
1341	my ($cb, $w, $rcb) = $arg{cb};	1663	my ($cb, $w, $rcb) = $arg{cb};
1342		1664
1343	$rcb = sub {	1665	$rcb = sub {
1344	if ($cb) {	1666	if ($cb) {
1345	$w = _time;	1667	$w = _time;
1346	&$cb;	1668	&$cb;
1347	$w = _time - $w;	1669	$w = _time - $w;
1348		1670
1349	# 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,
1350	# within some limits	1672	# within some limits
1351	$w = 0.0001 if $w < 0.0001;	1673	$w = 0.0001 if $w < 0.0001;
1352	$w = 5 if $w > 5;	1674	$w = 5 if $w > 5;
1353		1675
1354	$w = AnyEvent->timer (after => $w, cb => $rcb);	1676	$w = AE::timer $w, 0, $rcb;
1355	} else {	1677	} else {
1356	# clean up...	1678	# clean up...
1357	undef $w;	1679	undef $w;
1358	undef $rcb;	1680	undef $rcb;
		1681	}
		1682	};
		1683
		1684	$w = AE::timer 0.05, 0, $rcb;
		1685
		1686	bless \\$cb, "AnyEvent::Base::idle"
1359	}	1687	};
		1688
		1689	*AnyEvent::Base::idle::DESTROY = sub {
		1690	undef $${$_[0]};
		1691	};
1360	};	1692	};
		1693	die if $@;
1361		1694
1362	$w = AnyEvent->timer (after => 0.05, cb => $rcb);	1695	&idle
1363
1364	bless \\$cb, "AnyEvent::Base::idle"
1365	}
1366
1367	sub AnyEvent::Base::idle::DESTROY {
1368	undef $${$_[0]};
1369	}	1696	}
1370		1697
1371	package AnyEvent::CondVar;	1698	package AnyEvent::CondVar;
1372		1699
1373	our @ISA = AnyEvent::CondVar::Base::;	1700	our @ISA = AnyEvent::CondVar::Base::;
1374		1701
1375	package AnyEvent::CondVar::Base;	1702	package AnyEvent::CondVar::Base;
1376		1703
1377	use overload	1704	#use overload
1378	'&{}' => sub { my $self = shift; sub { $self->send (@_) } },	1705	# '&{}' => sub { my $self = shift; sub { $self->send (@_) } },
1379	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;
1380		1715
1381	sub _send {	1716	sub _send {
1382	# nop	1717	# nop
1383	}	1718	}
1384		1719
…		…
1397	sub ready {	1732	sub ready {
1398	$_[0]{_ae_sent}	1733	$_[0]{_ae_sent}
1399	}	1734	}
1400		1735
1401	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 $WAITING = 1;
1402	AnyEvent->one_event while !$_[0]{_ae_sent};	1742	AnyEvent->one_event while !$_[0]{_ae_sent};
1403	}	1743	}
1404		1744
1405	sub recv {	1745	sub recv {
1406	$_[0]->_wait;	1746	$_[0]->_wait;
…		…
1408	Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak};	1748	Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak};
1409	wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0]	1749	wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0]
1410	}	1750	}
1411		1751
1412	sub cb {	1752	sub cb {
1413	$_[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
1414	$_[0]{_ae_cb}	1760	$cv->{_ae_cb}
1415	}	1761	}
1416		1762
1417	sub begin {	1763	sub begin {
1418	++$_[0]{_ae_counter};	1764	++$_[0]{_ae_counter};
1419	$_[0]{_ae_end_cb} = $_[1] if @_ > 1;	1765	$_[0]{_ae_end_cb} = $_[1] if @_ > 1;
…		…
1468	C<PERL_ANYEVENT_MODEL>.	1814	C<PERL_ANYEVENT_MODEL>.
1469		1815
1470	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
1471	model it chooses.	1817	model it chooses.
1472		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
1473	=item C<PERL_ANYEVENT_STRICT>	1822	=item C<PERL_ANYEVENT_STRICT>
1474		1823
1475	AnyEvent does not do much argument checking by default, as thorough	1824	AnyEvent does not do much argument checking by default, as thorough
1476	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
1477	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
1478	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,
1479	it will croak.	1828	it will croak.
1480		1829
1481	In other words, enables "strict" mode.	1830	In other words, enables "strict" mode.
1482		1831
1483	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>
1484	production. Keeping C<PERL_ANYEVENT_STRICT=1> in your environment while	1833	>>, it is definitely recommended to keep it off in production. Keeping
1485	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.
1486		1836
1487	=item C<PERL_ANYEVENT_MODEL>	1837	=item C<PERL_ANYEVENT_MODEL>
1488		1838
1489	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
1490	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
…		…
1552		1902
1553	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
1554	L<AnyEvent::TLS> context creation, and either of these environment	1904	L<AnyEvent::TLS> context creation, and either of these environment
1555	variables exist, they will be used to specify CA certificate locations	1905	variables exist, they will be used to specify CA certificate locations
1556	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.
1557		1912
1558	=back	1913	=back
1559		1914
1560	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE	1915	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE
1561		1916
…		…
1619	warn "read: $input\n"; # output what has been read	1974	warn "read: $input\n"; # output what has been read
1620	$cv->send if $input =~ /^q/i; # quit program if /^q/i	1975	$cv->send if $input =~ /^q/i; # quit program if /^q/i
1621	},	1976	},
1622	);	1977	);
1623		1978
1624	my $time_watcher; # can only be used once
1625
1626	sub new_timer {
1627	$timer = AnyEvent->timer (after => 1, cb => sub {	1979	my $time_watcher = AnyEvent->timer (after => 1, interval => 1, cb => sub {
1628	warn "timeout\n"; # print 'timeout' about every second	1980	warn "timeout\n"; # print 'timeout' at most every second
1629	&new_timer; # and restart the time
1630	});	1981	});
1631	}
1632
1633	new_timer; # create first timer
1634		1982
1635	$cv->recv; # wait until user enters /^q/i	1983	$cv->recv; # wait until user enters /^q/i
1636		1984
1637	=head1 REAL-WORLD EXAMPLE	1985	=head1 REAL-WORLD EXAMPLE
1638		1986
…		…
1769	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
1770	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,
1771	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.
1772		2120
1773	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
1774	distribution.	2122	distribution. It uses the L<AE> interface, which makes a real difference
		2123	for the EV and Perl backends only.
1775		2124
1776	=head3 Explanation of the columns	2125	=head3 Explanation of the columns
1777		2126
1778	I<watcher> is the number of event watchers created/destroyed. Since	2127	I<watcher> is the number of event watchers created/destroyed. Since
1779	different event models feature vastly different performances, each event	2128	different event models feature vastly different performances, each event
…		…
1800	watcher.	2149	watcher.
1801		2150
1802	=head3 Results	2151	=head3 Results
1803		2152
1804	name watchers bytes create invoke destroy comment	2153	name watchers bytes create invoke destroy comment
1805	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
1806	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
1807	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
1808	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
1809	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
1810	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
1811	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
1812	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
1813	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
1814	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
1815	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
1816	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
1817		2166
1818	=head3 Discussion	2167	=head3 Discussion
1819		2168
1820	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
1821	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)
…		…
1833	benchmark machine, handling an event takes roughly 1600 CPU cycles with	2182	benchmark machine, handling an event takes roughly 1600 CPU cycles with
1834	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
1835	cycles with POE.	2184	cycles with POE.
1836		2185
1837	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
1838	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
1839	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).
1840	natively.
1841		2191
1842	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
1843	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
1844	interpreter and the backend itself). Nevertheless this shows that it	2194	interpreter and the backend itself). Nevertheless this shows that it
1845	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
…		…
1919	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
1920	(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
1921	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.
1922		2272
1923	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
1924	distribution.	2274	distribution. It uses the L<AE> interface, which makes a real difference
		2275	for the EV and Perl backends only.
1925		2276
1926	=head3 Explanation of the columns	2277	=head3 Explanation of the columns
1927		2278
1928	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
1929	each server has a read and write socket end).	2280	each server has a read and write socket end).
…		…
1937	a new one that moves the timeout into the future.	2288	a new one that moves the timeout into the future.
1938		2289
1939	=head3 Results	2290	=head3 Results
1940		2291
1941	name sockets create request	2292	name sockets create request
1942	EV 20000 69.01 11.16	2293	EV 20000 62.66 7.99
1943	Perl 20000 73.32 35.87	2294	Perl 20000 68.32 32.64
1944	IOAsync 20000 157.00 98.14 epoll	2295	IOAsync 20000 174.06 101.15 epoll
1945	IOAsync 20000 159.31 616.06 poll	2296	IOAsync 20000 174.67 610.84 poll
1946	Event 20000 212.62 257.32	2297	Event 20000 202.69 242.91
1947	Glib 20000 651.16 1896.30	2298	Glib 20000 557.01 1689.52
1948	POE 20000 349.67 12317.24 uses POE::Loop::Event	2299	POE 20000 341.54 12086.32 uses POE::Loop::Event
1949		2300
1950	=head3 Discussion	2301	=head3 Discussion
1951		2302
1952	This benchmark I<does> measure scalability and overall performance of the	2303	This benchmark I<does> measure scalability and overall performance of the
1953	particular event loop.	2304	particular event loop.
…		…
2079	As you can see, the AnyEvent + EV combination even beats the	2430	As you can see, the AnyEvent + EV combination even beats the
2080	hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl	2431	hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl
2081	backend easily beats IO::Lambda and POE.	2432	backend easily beats IO::Lambda and POE.
2082		2433
2083	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
2084	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
2085	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
2086	in a non-blocking way.	2437	it does all of DNS, tcp-connect and socket I/O in a non-blocking way.
2087		2438
2088	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
2089	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
2090	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.
2091		2442
2092		2443
2093	=head1 SIGNALS	2444	=head1 SIGNALS
2094		2445
2095	AnyEvent currently installs handlers for these signals:	2446	AnyEvent currently installs handlers for these signals:
…		…
2129	if $SIG{CHLD} eq 'IGNORE';	2480	if $SIG{CHLD} eq 'IGNORE';
2130		2481
2131	$SIG{PIPE} = sub { }	2482	$SIG{PIPE} = sub { }
2132	unless defined $SIG{PIPE};	2483	unless defined $SIG{PIPE};
2133		2484
		2485	=head1 RECOMMENDED/OPTIONAL MODULES
		2486
		2487	One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and
		2488	it's built-in modules) are required to use it.
		2489
		2490	That does not mean that AnyEvent won't take advantage of some additional
		2491	modules if they are installed.
		2492
		2493	This section explains which additional modules will be used, and how they
		2494	affect AnyEvent's operation.
		2495
		2496	=over 4
		2497
		2498	=item L<Async::Interrupt>
		2499
		2500	This slightly arcane module is used to implement fast signal handling: To
		2501	my knowledge, there is no way to do completely race-free and quick
		2502	signal handling in pure perl. To ensure that signals still get
		2503	delivered, AnyEvent will start an interval timer to wake up perl (and
		2504	catch the signals) with some delay (default is 10 seconds, look for
		2505	C<$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
2134	=head1 FORK	2563	=head1 FORK
2135		2564
2136	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
2137	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
2138	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).
2139		2577
2140	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
2141	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.
2142		2590
2143		2591
2144	=head1 SECURITY CONSIDERATIONS	2592	=head1 SECURITY CONSIDERATIONS
2145		2593
2146	AnyEvent can be forced to load any event model via	2594	AnyEvent can be forced to load any event model via
…		…
2184	L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.	2632	L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.
2185		2633
2186	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,	2634	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,
2187	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>,
2188	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,	2636	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,
2189	L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>.	2637	L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>, L<Anyevent::Impl::Irssi>.
2190		2638
2191	Non-blocking file handles, sockets, TCP clients and	2639	Non-blocking file handles, sockets, TCP clients and
2192	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.	2640	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.
2193		2641
2194	Asynchronous DNS: L<AnyEvent::DNS>.	2642	Asynchronous DNS: L<AnyEvent::DNS>.

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