ViewVC Help

View File | Revision Log | Show Annotations | Download File

/cvs/AnyEvent/lib/AnyEvent.pm

Comparing AnyEvent/lib/AnyEvent.pm (file contents):
Revision 1.223 by root, Mon Jun 29 21:00:32 2009 UTC vs.
Revision 1.309 by root, Sat Dec 26 08:59:35 2009 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> (I<not> 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
183	handle). Note that only file handles pointing to things for which	197	handle). Note that only file handles pointing to things for which
184	non-blocking operation makes sense are allowed. This includes sockets,	198	non-blocking operation makes sense are allowed. This includes sockets,
185	most character devices, pipes, fifos and so on, but not for example files	199	most character devices, pipes, fifos and so on, but not for example files
186	or block devices.	200	or block devices.
…		…
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 = 4.45;	1161	our $VERSION = '5.23';
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 $VERBOSE;
982		1170
983	BEGIN {	1171	BEGIN {
984	eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }";	1172	eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }";
985	eval "sub TAINT(){ " . (${^TAINT}*1) . " }";	1173	eval "sub TAINT(){ " . (${^TAINT}*1) . " }";
986		1174
987	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}	1175	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}
988	if ${^TAINT};	1176	if ${^TAINT};
989	}
990		1177
991	our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1;	1178	$VERBOSE = $ENV{PERL_ANYEVENT_VERBOSE}*1;
		1179
		1180	}
		1181
		1182	our $MAX_SIGNAL_LATENCY = 10;
992		1183
993	our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred	1184	our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred
994		1185
995	{	1186	{
996	my $idx;	1187	my $idx;
…		…
998	for reverse split /\s*,\s*/,	1189	for reverse split /\s*,\s*/,
999	$ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";	1190	$ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";
1000	}	1191	}
1001		1192
1002	my @models = (	1193	my @models = (
1003	[EV:: => AnyEvent::Impl::EV::],	1194	[EV:: => AnyEvent::Impl::EV:: , 1],
1004	[Event:: => AnyEvent::Impl::Event::],
1005	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::],	1195	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl:: , 1],
1006	# everything below here will not be autoprobed	1196	# everything below here will not (normally) be autoprobed
1007	# as the pureperl backend should work everywhere	1197	# as the pureperl backend should work everywhere
1008	# and is usually faster	1198	# and is usually faster
		1199	[Event:: => AnyEvent::Impl::Event::, 1],
		1200	[Glib:: => AnyEvent::Impl::Glib:: , 1], # becomes extremely slow with many watchers
		1201	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
		1202	[Irssi:: => AnyEvent::Impl::Irssi::], # Irssi has a bogus "Event" package
1009	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles	1203	[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	1204	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program
1013	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza	1205	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
1014	[Wx:: => AnyEvent::Impl::POE::],	1206	[Wx:: => AnyEvent::Impl::POE::],
1015	[Prima:: => AnyEvent::Impl::POE::],	1207	[Prima:: => AnyEvent::Impl::POE::],
1016	# IO::Async is just too broken - we would need workaorunds for its	1208	# IO::Async is just too broken - we would need workarounds for its
1017	# byzantine signal and broken child handling, among others.	1209	# byzantine signal and broken child handling, among others.
1018	# IO::Async is rather hard to detect, as it doesn't have any	1210	# IO::Async is rather hard to detect, as it doesn't have any
1019	# obvious default class.	1211	# obvious default class.
1020	# [IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program	1212	[IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program
1021	# [IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program	1213	[IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program
1022	# [IO::Async::Notifier:: => AnyEvent::Impl::IOAsync::], # requires special main program	1214	[IO::Async::Notifier:: => AnyEvent::Impl::IOAsync::], # requires special main program
		1215	[AnyEvent::Impl::IOAsync:: => AnyEvent::Impl::IOAsync::], # requires special main program
1023	);	1216	);
1024		1217
1025	our %method = map +($_ => 1),	1218	our %method = map +($_ => 1),
1026	qw(io timer time now now_update signal child idle condvar one_event DESTROY);	1219	qw(io timer time now now_update signal child idle condvar one_event DESTROY);
1027		1220
…		…
1031	my ($cb) = @_;	1224	my ($cb) = @_;
1032		1225
1033	if ($MODEL) {	1226	if ($MODEL) {
1034	$cb->();	1227	$cb->();
1035		1228
1036	1	1229	undef
1037	} else {	1230	} else {
1038	push @post_detect, $cb;	1231	push @post_detect, $cb;
1039		1232
1040	defined wantarray	1233	defined wantarray
1041	? bless \$cb, "AnyEvent::Util::postdetect"	1234	? bless \$cb, "AnyEvent::Util::postdetect"
…		…
1047	@post_detect = grep $_ != ${$_[0]}, @post_detect;	1240	@post_detect = grep $_ != ${$_[0]}, @post_detect;
1048	}	1241	}
1049		1242
1050	sub detect() {	1243	sub detect() {
1051	unless ($MODEL) {	1244	unless ($MODEL) {
1052	no strict 'refs';
1053	local $SIG{__DIE__};	1245	local $SIG{__DIE__};
1054		1246
1055	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {	1247	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {
1056	my $model = "AnyEvent::Impl::$1";	1248	my $model = "AnyEvent::Impl::$1";
1057	if (eval "require $model") {	1249	if (eval "require $model") {
1058	$MODEL = $model;	1250	$MODEL = $model;
1059	warn "AnyEvent: loaded model '$model' (forced by \$PERL_ANYEVENT_MODEL), using it.\n" if $verbose > 1;	1251	warn "AnyEvent: loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.\n" if $VERBOSE >= 2;
1060	} else {	1252	} else {
1061	warn "AnyEvent: unable to load model '$model' (from \$PERL_ANYEVENT_MODEL):\n$@" if $verbose;	1253	warn "AnyEvent: unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@" if $VERBOSE;
1062	}	1254	}
1063	}	1255	}
1064		1256
1065	# check for already loaded models	1257	# check for already loaded models
1066	unless ($MODEL) {	1258	unless ($MODEL) {
1067	for (@REGISTRY, @models) {	1259	for (@REGISTRY, @models) {
1068	my ($package, $model) = @$_;	1260	my ($package, $model) = @$_;
1069	if (${"$package\::VERSION"} > 0) {	1261	if (${"$package\::VERSION"} > 0) {
1070	if (eval "require $model") {	1262	if (eval "require $model") {
1071	$MODEL = $model;	1263	$MODEL = $model;
1072	warn "AnyEvent: autodetected model '$model', using it.\n" if $verbose > 1;	1264	warn "AnyEvent: autodetected model '$model', using it.\n" if $VERBOSE >= 2;
1073	last;	1265	last;
1074	}	1266	}
1075	}	1267	}
1076	}	1268	}
1077		1269
1078	unless ($MODEL) {	1270	unless ($MODEL) {
1079	# try to load a model	1271	# try to autoload a model
1080
1081	for (@REGISTRY, @models) {	1272	for (@REGISTRY, @models) {
1082	my ($package, $model) = @$_;	1273	my ($package, $model, $autoload) = @$_;
		1274	if (
		1275	$autoload
1083	if (eval "require $package"	1276	and eval "require $package"
1084	and ${"$package\::VERSION"} > 0	1277	and ${"$package\::VERSION"} > 0
1085	and eval "require $model") {	1278	and eval "require $model"
		1279	) {
1086	$MODEL = $model;	1280	$MODEL = $model;
1087	warn "AnyEvent: autoprobed model '$model', using it.\n" if $verbose > 1;	1281	warn "AnyEvent: autoloaded model '$model', using it.\n" if $VERBOSE >= 2;
1088	last;	1282	last;
1089	}	1283	}
1090	}	1284	}
1091		1285
1092	$MODEL	1286	$MODEL
…		…
1108		1302
1109	sub AUTOLOAD {	1303	sub AUTOLOAD {
1110	(my $func = $AUTOLOAD) =~ s/.*://;	1304	(my $func = $AUTOLOAD) =~ s/.*://;
1111		1305
1112	$method{$func}	1306	$method{$func}
1113	or croak "$func: not a valid method for AnyEvent objects";	1307	or Carp::croak "$func: not a valid method for AnyEvent objects";
1114		1308
1115	detect unless $MODEL;	1309	detect unless $MODEL;
1116		1310
1117	my $class = shift;	1311	my $class = shift;
1118	$class->$func (@_);	1312	$class->$func (@_);
…		…
1123	# allow only one watcher per fd, so we dup it to get a different one).	1317	# allow only one watcher per fd, so we dup it to get a different one).
1124	sub _dupfh($$;$$) {	1318	sub _dupfh($$;$$) {
1125	my ($poll, $fh, $r, $w) = @_;	1319	my ($poll, $fh, $r, $w) = @_;
1126		1320
1127	# cygwin requires the fh mode to be matching, unix doesn't	1321	# cygwin requires the fh mode to be matching, unix doesn't
1128	my ($rw, $mode) = $poll eq "r" ? ($r, "<")	1322	my ($rw, $mode) = $poll eq "r" ? ($r, "<&") : ($w, ">&");
1129	: $poll eq "w" ? ($w, ">")
1130	: Carp::croak "AnyEvent->io requires poll set to either 'r' or 'w'";
1131		1323
1132	open my $fh2, "$mode&" . fileno $fh	1324	open my $fh2, $mode, $fh
1133	or die "cannot dup() filehandle: $!,";	1325	or die "AnyEvent->io: cannot dup() filehandle in mode '$poll': $!,";
1134		1326
1135	# we assume CLOEXEC is already set by perl in all important cases	1327	# we assume CLOEXEC is already set by perl in all important cases
1136		1328
1137	($fh2, $rw)	1329	($fh2, $rw)
1138	}	1330	}
1139		1331
		1332	=head1 SIMPLIFIED AE API
		1333
		1334	Starting with version 5.0, AnyEvent officially supports a second, much
		1335	simpler, API that is designed to reduce the calling, typing and memory
		1336	overhead.
		1337
		1338	See the L<AE> manpage for details.
		1339
		1340	=cut
		1341
		1342	package AE;
		1343
		1344	our $VERSION = $AnyEvent::VERSION;
		1345
		1346	sub io($$$) {
		1347	AnyEvent->io (fh => $_[0], poll => $_[1] ? "w" : "r", cb => $_[2])
		1348	}
		1349
		1350	sub timer($$$) {
		1351	AnyEvent->timer (after => $_[0], interval => $_[1], cb => $_[2])
		1352	}
		1353
		1354	sub signal($$) {
		1355	AnyEvent->signal (signal => $_[0], cb => $_[1])
		1356	}
		1357
		1358	sub child($$) {
		1359	AnyEvent->child (pid => $_[0], cb => $_[1])
		1360	}
		1361
		1362	sub idle($) {
		1363	AnyEvent->idle (cb => $_[0])
		1364	}
		1365
		1366	sub cv(;&) {
		1367	AnyEvent->condvar (@_ ? (cb => $_[0]) : ())
		1368	}
		1369
		1370	sub now() {
		1371	AnyEvent->now
		1372	}
		1373
		1374	sub now_update() {
		1375	AnyEvent->now_update
		1376	}
		1377
		1378	sub time() {
		1379	AnyEvent->time
		1380	}
		1381
1140	package AnyEvent::Base;	1382	package AnyEvent::Base;
1141		1383
1142	# default implementations for many methods	1384	# default implementations for many methods
1143		1385
1144	BEGIN {	1386	sub _time() {
		1387	# probe for availability of Time::HiRes
1145	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {	1388	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {
		1389	warn "AnyEvent: using Time::HiRes for sub-second timing accuracy.\n" if $VERBOSE >= 8;
1146	*_time = \&Time::HiRes::time;	1390	*_time = \&Time::HiRes::time;
1147	# if (eval "use POSIX (); (POSIX::times())...	1391	# if (eval "use POSIX (); (POSIX::times())...
1148	} else {	1392	} else {
		1393	warn "AnyEvent: using built-in time(), WARNING, no sub-second resolution!\n" if $VERBOSE;
1149	*_time = sub { time }; # epic fail	1394	*_time = sub { time }; # epic fail
1150	}	1395	}
		1396
		1397	&_time
1151	}	1398	}
1152		1399
1153	sub time { _time }	1400	sub time { _time }
1154	sub now { _time }	1401	sub now { _time }
1155	sub now_update { }	1402	sub now_update { }
…		…
1160	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"	1407	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"
1161	}	1408	}
1162		1409
1163	# default implementation for ->signal	1410	# default implementation for ->signal
1164		1411
		1412	our $HAVE_ASYNC_INTERRUPT;
		1413
		1414	sub _have_async_interrupt() {
		1415	$HAVE_ASYNC_INTERRUPT = 1*(!$ENV{PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT}
		1416	&& eval "use Async::Interrupt 1.02 (); 1")
		1417	unless defined $HAVE_ASYNC_INTERRUPT;
		1418
		1419	$HAVE_ASYNC_INTERRUPT
		1420	}
		1421
1165	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);	1422	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);
		1423	our (%SIG_ASY, %SIG_ASY_W);
		1424	our ($SIG_COUNT, $SIG_TW);
1166		1425
1167	sub _signal_exec {	1426	sub _signal_exec {
		1427	$HAVE_ASYNC_INTERRUPT
		1428	? $SIGPIPE_R->drain
1168	sysread $SIGPIPE_R, my $dummy, 4;	1429	: sysread $SIGPIPE_R, (my $dummy), 9;
1169		1430
1170	while (%SIG_EV) {	1431	while (%SIG_EV) {
1171	for (keys %SIG_EV) {	1432	for (keys %SIG_EV) {
1172	delete $SIG_EV{$_};	1433	delete $SIG_EV{$_};
1173	$_->() for values %{ $SIG_CB{$_} || {} };	1434	$_->() for values %{ $SIG_CB{$_} || {} };
1174	}	1435	}
1175	}	1436	}
1176	}	1437	}
1177		1438
		1439	# install a dummy wakeup watcher to reduce signal catching latency
		1440	sub _sig_add() {
		1441	unless ($SIG_COUNT++) {
		1442	# try to align timer on a full-second boundary, if possible
		1443	my $NOW = AE::now;
		1444
		1445	$SIG_TW = AE::timer
		1446	$MAX_SIGNAL_LATENCY - ($NOW - int $NOW),
		1447	$MAX_SIGNAL_LATENCY,
		1448	sub { } # just for the PERL_ASYNC_CHECK
		1449	;
		1450	}
		1451	}
		1452
		1453	sub _sig_del {
		1454	undef $SIG_TW
		1455	unless --$SIG_COUNT;
		1456	}
		1457
		1458	our $_sig_name_init; $_sig_name_init = sub {
		1459	eval q{ # poor man's autoloading
		1460	undef $_sig_name_init;
		1461
		1462	if (_have_async_interrupt) {
		1463	*sig2num = \&Async::Interrupt::sig2num;
		1464	*sig2name = \&Async::Interrupt::sig2name;
		1465	} else {
		1466	require Config;
		1467
		1468	my %signame2num;
		1469	@signame2num{ split ' ', $Config::Config{sig_name} }
		1470	= split ' ', $Config::Config{sig_num};
		1471
		1472	my @signum2name;
		1473	@signum2name[values %signame2num] = keys %signame2num;
		1474
		1475	*sig2num = sub($) {
		1476	$_[0] > 0 ? shift : $signame2num{+shift}
		1477	};
		1478	*sig2name = sub ($) {
		1479	$_[0] > 0 ? $signum2name[+shift] : shift
		1480	};
		1481	}
		1482	};
		1483	die if $@;
		1484	};
		1485
		1486	sub sig2num ($) { &$_sig_name_init; &sig2num }
		1487	sub sig2name($) { &$_sig_name_init; &sig2name }
		1488
1178	sub signal {	1489	sub signal {
1179	my (undef, %arg) = @_;	1490	eval q{ # poor man's autoloading {}
		1491	# probe for availability of Async::Interrupt
		1492	if (_have_async_interrupt) {
		1493	warn "AnyEvent: using Async::Interrupt for race-free signal handling.\n" if $VERBOSE >= 8;
1180		1494
1181	unless ($SIGPIPE_R) {	1495	$SIGPIPE_R = new Async::Interrupt::EventPipe;
1182	require Fcntl;	1496	$SIG_IO = AE::io $SIGPIPE_R->fileno, 0, \&_signal_exec;
1183		1497
1184	if (AnyEvent::WIN32) {
1185	require AnyEvent::Util;
1186
1187	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
1188	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R) if $SIGPIPE_R;
1189	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W) if $SIGPIPE_W; # just in case
1190	} else {	1498	} else {
		1499	warn "AnyEvent: using emulated perl signal handling with latency timer.\n" if $VERBOSE >= 8;
		1500
		1501	require Fcntl;
		1502
		1503	if (AnyEvent::WIN32) {
		1504	require AnyEvent::Util;
		1505
		1506	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
		1507	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R, 1) if $SIGPIPE_R;
		1508	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W, 1) if $SIGPIPE_W; # just in case
		1509	} else {
1191	pipe $SIGPIPE_R, $SIGPIPE_W;	1510	pipe $SIGPIPE_R, $SIGPIPE_W;
1192	fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R;	1511	fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R;
1193	fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case	1512	fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case
1194		1513
1195	# not strictly required, as $^F is normally 2, but let's make sure...	1514	# not strictly required, as $^F is normally 2, but let's make sure...
1196	fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;	1515	fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
1197	fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;	1516	fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
		1517	}
		1518
		1519	$SIGPIPE_R
		1520	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";
		1521
		1522	$SIG_IO = AE::io $SIGPIPE_R, 0, \&_signal_exec;
1198	}	1523	}
1199		1524
1200	$SIGPIPE_R	1525	*signal = sub {
1201	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";	1526	my (undef, %arg) = @_;
1202		1527
1203	$SIG_IO = AnyEvent->io (fh => $SIGPIPE_R, poll => "r", cb => \&_signal_exec);
1204	}
1205
1206	my $signal = uc $arg{signal}	1528	my $signal = uc $arg{signal}
1207	or Carp::croak "required option 'signal' is missing";	1529	or Carp::croak "required option 'signal' is missing";
1208		1530
		1531	if ($HAVE_ASYNC_INTERRUPT) {
		1532	# async::interrupt
		1533
		1534	$signal = sig2num $signal;
1209	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};	1535	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
		1536
		1537	$SIG_ASY{$signal} ||= new Async::Interrupt
		1538	cb => sub { undef $SIG_EV{$signal} },
		1539	signal => $signal,
		1540	pipe => [$SIGPIPE_R->filenos],
		1541	pipe_autodrain => 0,
		1542	;
		1543
		1544	} else {
		1545	# pure perl
		1546
		1547	# AE::Util has been loaded in signal
		1548	$signal = sig2name $signal;
		1549	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
		1550
1210	$SIG{$signal} ||= sub {	1551	$SIG{$signal} ||= sub {
1211	local $!;	1552	local $!;
1212	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;	1553	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;
1213	undef $SIG_EV{$signal};	1554	undef $SIG_EV{$signal};
		1555	};
		1556
		1557	# can't do signal processing without introducing races in pure perl,
		1558	# so limit the signal latency.
		1559	_sig_add;
		1560	}
		1561
		1562	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
		1563	};
		1564
		1565	*AnyEvent::Base::signal::DESTROY = sub {
		1566	my ($signal, $cb) = @{$_[0]};
		1567
		1568	_sig_del;
		1569
		1570	delete $SIG_CB{$signal}{$cb};
		1571
		1572	$HAVE_ASYNC_INTERRUPT
		1573	? delete $SIG_ASY{$signal}
		1574	: # delete doesn't work with older perls - they then
		1575	# print weird messages, or just unconditionally exit
		1576	# instead of getting the default action.
		1577	undef $SIG{$signal}
		1578	unless keys %{ $SIG_CB{$signal} };
		1579	};
1214	};	1580	};
1215		1581	die if $@;
1216	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"	1582	&signal
1217	}
1218
1219	sub AnyEvent::Base::signal::DESTROY {
1220	my ($signal, $cb) = @{$_[0]};
1221
1222	delete $SIG_CB{$signal}{$cb};
1223
1224	# delete doesn't work with older perls - they then
1225	# print weird messages, or just unconditionally exit
1226	# instead of getting the default action.
1227	undef $SIG{$signal} unless keys %{ $SIG_CB{$signal} };
1228	}	1583	}
1229		1584
1230	# default implementation for ->child	1585	# default implementation for ->child
1231		1586
1232	our %PID_CB;	1587	our %PID_CB;
1233	our $CHLD_W;	1588	our $CHLD_W;
1234	our $CHLD_DELAY_W;	1589	our $CHLD_DELAY_W;
1235	our $WNOHANG;	1590	our $WNOHANG;
1236		1591
		1592	sub _emit_childstatus($$) {
		1593	my (undef, $rpid, $rstatus) = @_;
		1594
		1595	$_->($rpid, $rstatus)
		1596	for values %{ $PID_CB{$rpid} || {} },
		1597	values %{ $PID_CB{0} || {} };
		1598	}
		1599
1237	sub _sigchld {	1600	sub _sigchld {
		1601	my $pid;
		1602
		1603	AnyEvent->_emit_childstatus ($pid, $?)
1238	while (0 < (my $pid = waitpid -1, $WNOHANG)) {	1604	while ($pid = waitpid -1, $WNOHANG) > 0;
1239	$_->($pid, $?) for (values %{ $PID_CB{$pid} || {} }),
1240	(values %{ $PID_CB{0} || {} });
1241	}
1242	}	1605	}
1243		1606
1244	sub child {	1607	sub child {
1245	my (undef, %arg) = @_;	1608	my (undef, %arg) = @_;
1246		1609
1247	defined (my $pid = $arg{pid} + 0)	1610	defined (my $pid = $arg{pid} + 0)
1248	or Carp::croak "required option 'pid' is missing";	1611	or Carp::croak "required option 'pid' is missing";
1249		1612
1250	$PID_CB{$pid}{$arg{cb}} = $arg{cb};	1613	$PID_CB{$pid}{$arg{cb}} = $arg{cb};
1251		1614
		1615	# WNOHANG is almost cetrainly 1 everywhere
		1616	$WNOHANG ||= $^O =~ /^(?:openbsd|netbsd|linux|freebsd|cygwin|MSWin32)$/
		1617	? 1
1252	$WNOHANG ||= eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1;	1618	: eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1;
1253		1619
1254	unless ($CHLD_W) {	1620	unless ($CHLD_W) {
1255	$CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld);	1621	$CHLD_W = AE::signal CHLD => \&_sigchld;
1256	# child could be a zombie already, so make at least one round	1622	# child could be a zombie already, so make at least one round
1257	&_sigchld;	1623	&_sigchld;
1258	}	1624	}
1259		1625
1260	bless [$pid, $arg{cb}], "AnyEvent::Base::child"	1626	bless [$pid, $arg{cb}], "AnyEvent::Base::child"
…		…
1286	# never use more then 50% of the time for the idle watcher,	1652	# never use more then 50% of the time for the idle watcher,
1287	# within some limits	1653	# within some limits
1288	$w = 0.0001 if $w < 0.0001;	1654	$w = 0.0001 if $w < 0.0001;
1289	$w = 5 if $w > 5;	1655	$w = 5 if $w > 5;
1290		1656
1291	$w = AnyEvent->timer (after => $w, cb => $rcb);	1657	$w = AE::timer $w, 0, $rcb;
1292	} else {	1658	} else {
1293	# clean up...	1659	# clean up...
1294	undef $w;	1660	undef $w;
1295	undef $rcb;	1661	undef $rcb;
1296	}	1662	}
1297	};	1663	};
1298		1664
1299	$w = AnyEvent->timer (after => 0.05, cb => $rcb);	1665	$w = AE::timer 0.05, 0, $rcb;
1300		1666
1301	bless \\$cb, "AnyEvent::Base::idle"	1667	bless \\$cb, "AnyEvent::Base::idle"
1302	}	1668	}
1303		1669
1304	sub AnyEvent::Base::idle::DESTROY {	1670	sub AnyEvent::Base::idle::DESTROY {
…		…
1309		1675
1310	our @ISA = AnyEvent::CondVar::Base::;	1676	our @ISA = AnyEvent::CondVar::Base::;
1311		1677
1312	package AnyEvent::CondVar::Base;	1678	package AnyEvent::CondVar::Base;
1313		1679
1314	use overload	1680	#use overload
1315	'&{}' => sub { my $self = shift; sub { $self->send (@_) } },	1681	# '&{}' => sub { my $self = shift; sub { $self->send (@_) } },
1316	fallback => 1;	1682	# fallback => 1;
		1683
		1684	# save 300+ kilobytes by dirtily hardcoding overloading
		1685	${"AnyEvent::CondVar::Base::OVERLOAD"}{dummy}++; # Register with magic by touching.
		1686	*{'AnyEvent::CondVar::Base::()'} = sub { }; # "Make it findable via fetchmethod."
		1687	*{'AnyEvent::CondVar::Base::(&{}'} = sub { my $self = shift; sub { $self->send (@_) } }; # &{}
		1688	${'AnyEvent::CondVar::Base::()'} = 1; # fallback
		1689
		1690	our $WAITING;
1317		1691
1318	sub _send {	1692	sub _send {
1319	# nop	1693	# nop
1320	}	1694	}
1321		1695
…		…
1334	sub ready {	1708	sub ready {
1335	$_[0]{_ae_sent}	1709	$_[0]{_ae_sent}
1336	}	1710	}
1337		1711
1338	sub _wait {	1712	sub _wait {
		1713	$WAITING
		1714	and !$_[0]{_ae_sent}
		1715	and Carp::croak "AnyEvent::CondVar: recursive blocking wait detected";
		1716
		1717	local $WAITING = 1;
1339	AnyEvent->one_event while !$_[0]{_ae_sent};	1718	AnyEvent->one_event while !$_[0]{_ae_sent};
1340	}	1719	}
1341		1720
1342	sub recv {	1721	sub recv {
1343	$_[0]->_wait;	1722	$_[0]->_wait;
…		…
1345	Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak};	1724	Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak};
1346	wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0]	1725	wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0]
1347	}	1726	}
1348		1727
1349	sub cb {	1728	sub cb {
1350	$_[0]{_ae_cb} = $_[1] if @_ > 1;	1729	my $cv = shift;
		1730
		1731	@_
		1732	and $cv->{_ae_cb} = shift
		1733	and $cv->{_ae_sent}
		1734	and (delete $cv->{_ae_cb})->($cv);
		1735
1351	$_[0]{_ae_cb}	1736	$cv->{_ae_cb}
1352	}	1737	}
1353		1738
1354	sub begin {	1739	sub begin {
1355	++$_[0]{_ae_counter};	1740	++$_[0]{_ae_counter};
1356	$_[0]{_ae_end_cb} = $_[1] if @_ > 1;	1741	$_[0]{_ae_end_cb} = $_[1] if @_ > 1;
…		…
1405	C<PERL_ANYEVENT_MODEL>.	1790	C<PERL_ANYEVENT_MODEL>.
1406		1791
1407	When set to C<2> or higher, cause AnyEvent to report to STDERR which event	1792	When set to C<2> or higher, cause AnyEvent to report to STDERR which event
1408	model it chooses.	1793	model it chooses.
1409		1794
		1795	When set to C<8> or higher, then AnyEvent will report extra information on
		1796	which optional modules it loads and how it implements certain features.
		1797
1410	=item C<PERL_ANYEVENT_STRICT>	1798	=item C<PERL_ANYEVENT_STRICT>
1411		1799
1412	AnyEvent does not do much argument checking by default, as thorough	1800	AnyEvent does not do much argument checking by default, as thorough
1413	argument checking is very costly. Setting this variable to a true value	1801	argument checking is very costly. Setting this variable to a true value
1414	will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly	1802	will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly
1415	check the arguments passed to most method calls. If it finds any problems,	1803	check the arguments passed to most method calls. If it finds any problems,
1416	it will croak.	1804	it will croak.
1417		1805
1418	In other words, enables "strict" mode.	1806	In other words, enables "strict" mode.
1419		1807
1420	Unlike C<use strict>, it is definitely recommended to keep it off in	1808	Unlike C<use strict> (or it's modern cousin, C<< use L<common::sense>
1421	production. Keeping C<PERL_ANYEVENT_STRICT=1> in your environment while	1809	>>, it is definitely recommended to keep it off in production. Keeping
1422	developing programs can be very useful, however.	1810	C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs
		1811	can be very useful, however.
1423		1812
1424	=item C<PERL_ANYEVENT_MODEL>	1813	=item C<PERL_ANYEVENT_MODEL>
1425		1814
1426	This can be used to specify the event model to be used by AnyEvent, before	1815	This can be used to specify the event model to be used by AnyEvent, before
1427	auto detection and -probing kicks in. It must be a string consisting	1816	auto detection and -probing kicks in. It must be a string consisting
…		…
1470		1859
1471	=item C<PERL_ANYEVENT_MAX_FORKS>	1860	=item C<PERL_ANYEVENT_MAX_FORKS>
1472		1861
1473	The maximum number of child processes that C<AnyEvent::Util::fork_call>	1862	The maximum number of child processes that C<AnyEvent::Util::fork_call>
1474	will create in parallel.	1863	will create in parallel.
		1864
		1865	=item C<PERL_ANYEVENT_MAX_OUTSTANDING_DNS>
		1866
		1867	The default value for the C<max_outstanding> parameter for the default DNS
		1868	resolver - this is the maximum number of parallel DNS requests that are
		1869	sent to the DNS server.
		1870
		1871	=item C<PERL_ANYEVENT_RESOLV_CONF>
		1872
		1873	The file to use instead of F</etc/resolv.conf> (or OS-specific
		1874	configuration) in the default resolver. When set to the empty string, no
		1875	default config will be used.
		1876
		1877	=item C<PERL_ANYEVENT_CA_FILE>, C<PERL_ANYEVENT_CA_PATH>.
		1878
		1879	When neither C<ca_file> nor C<ca_path> was specified during
		1880	L<AnyEvent::TLS> context creation, and either of these environment
		1881	variables exist, they will be used to specify CA certificate locations
		1882	instead of a system-dependent default.
		1883
		1884	=item C<PERL_ANYEVENT_AVOID_GUARD> and C<PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT>
		1885
		1886	When these are set to C<1>, then the respective modules are not
		1887	loaded. Mostly good for testing AnyEvent itself.
1475		1888
1476	=back	1889	=back
1477		1890
1478	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE	1891	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE
1479		1892
…		…
1537	warn "read: $input\n"; # output what has been read	1950	warn "read: $input\n"; # output what has been read
1538	$cv->send if $input =~ /^q/i; # quit program if /^q/i	1951	$cv->send if $input =~ /^q/i; # quit program if /^q/i
1539	},	1952	},
1540	);	1953	);
1541		1954
1542	my $time_watcher; # can only be used once
1543
1544	sub new_timer {
1545	$timer = AnyEvent->timer (after => 1, cb => sub {	1955	my $time_watcher = AnyEvent->timer (after => 1, interval => 1, cb => sub {
1546	warn "timeout\n"; # print 'timeout' about every second	1956	warn "timeout\n"; # print 'timeout' at most every second
1547	&new_timer; # and restart the time
1548	});	1957	});
1549	}
1550
1551	new_timer; # create first timer
1552		1958
1553	$cv->recv; # wait until user enters /^q/i	1959	$cv->recv; # wait until user enters /^q/i
1554		1960
1555	=head1 REAL-WORLD EXAMPLE	1961	=head1 REAL-WORLD EXAMPLE
1556		1962
…		…
1687	through AnyEvent. The benchmark creates a lot of timers (with a zero	2093	through AnyEvent. The benchmark creates a lot of timers (with a zero
1688	timeout) and I/O watchers (watching STDOUT, a pty, to become writable,	2094	timeout) and I/O watchers (watching STDOUT, a pty, to become writable,
1689	which it is), lets them fire exactly once and destroys them again.	2095	which it is), lets them fire exactly once and destroys them again.
1690		2096
1691	Source code for this benchmark is found as F<eg/bench> in the AnyEvent	2097	Source code for this benchmark is found as F<eg/bench> in the AnyEvent
1692	distribution.	2098	distribution. It uses the L<AE> interface, which makes a real difference
		2099	for the EV and Perl backends only.
1693		2100
1694	=head3 Explanation of the columns	2101	=head3 Explanation of the columns
1695		2102
1696	I<watcher> is the number of event watchers created/destroyed. Since	2103	I<watcher> is the number of event watchers created/destroyed. Since
1697	different event models feature vastly different performances, each event	2104	different event models feature vastly different performances, each event
…		…
1718	watcher.	2125	watcher.
1719		2126
1720	=head3 Results	2127	=head3 Results
1721		2128
1722	name watchers bytes create invoke destroy comment	2129	name watchers bytes create invoke destroy comment
1723	EV/EV 400000 224 0.47 0.35 0.27 EV native interface	2130	EV/EV 100000 223 0.47 0.43 0.27 EV native interface
1724	EV/Any 100000 224 2.88 0.34 0.27 EV + AnyEvent watchers	2131	EV/Any 100000 223 0.48 0.42 0.26 EV + AnyEvent watchers
1725	CoroEV/Any 100000 224 2.85 0.35 0.28 coroutines + Coro::Signal	2132	Coro::EV/Any 100000 223 0.47 0.42 0.26 coroutines + Coro::Signal
1726	Perl/Any 100000 452 4.13 0.73 0.95 pure perl implementation	2133	Perl/Any 100000 431 2.70 0.74 0.92 pure perl implementation
1727	Event/Event 16000 517 32.20 31.80 0.81 Event native interface	2134	Event/Event 16000 516 31.16 31.84 0.82 Event native interface
1728	Event/Any 16000 590 35.85 31.55 1.06 Event + AnyEvent watchers	2135	Event/Any 16000 1203 42.61 34.79 1.80 Event + AnyEvent watchers
1729	IOAsync/Any 16000 989 38.10 32.77 11.13 via IO::Async::Loop::IO_Poll	2136	IOAsync/Any 16000 1911 41.92 27.45 16.81 via IO::Async::Loop::IO_Poll
1730	IOAsync/Any 16000 990 37.59 29.50 10.61 via IO::Async::Loop::Epoll	2137	IOAsync/Any 16000 1726 40.69 26.37 15.25 via IO::Async::Loop::Epoll
1731	Glib/Any 16000 1357 102.33 12.31 51.00 quadratic behaviour	2138	Glib/Any 16000 1118 89.00 12.57 51.17 quadratic behaviour
1732	Tk/Any 2000 1860 27.20 66.31 14.00 SEGV with >> 2000 watchers	2139	Tk/Any 2000 1346 20.96 10.75 8.00 SEGV with >> 2000 watchers
1733	POE/Event 2000 6328 109.99 751.67 14.02 via POE::Loop::Event	2140	POE/Any 2000 6951 108.97 795.32 14.24 via POE::Loop::Event
1734	POE/Select 2000 6027 94.54 809.13 579.80 via POE::Loop::Select	2141	POE/Any 2000 6648 94.79 774.40 575.51 via POE::Loop::Select
1735		2142
1736	=head3 Discussion	2143	=head3 Discussion
1737		2144
1738	The benchmark does I<not> measure scalability of the event loop very	2145	The benchmark does I<not> measure scalability of the event loop very
1739	well. For example, a select-based event loop (such as the pure perl one)	2146	well. For example, a select-based event loop (such as the pure perl one)
…		…
1751	benchmark machine, handling an event takes roughly 1600 CPU cycles with	2158	benchmark machine, handling an event takes roughly 1600 CPU cycles with
1752	EV, 3100 CPU cycles with AnyEvent's pure perl loop and almost 3000000 CPU	2159	EV, 3100 CPU cycles with AnyEvent's pure perl loop and almost 3000000 CPU
1753	cycles with POE.	2160	cycles with POE.
1754		2161
1755	C<EV> is the sole leader regarding speed and memory use, which are both	2162	C<EV> is the sole leader regarding speed and memory use, which are both
1756	maximal/minimal, respectively. Even when going through AnyEvent, it uses	2163	maximal/minimal, respectively. When using the L<AE> API there is zero
		2164	overhead (when going through the AnyEvent API create is about 5-6 times
		2165	slower, with other times being equal, so still uses far less memory than
1757	far less memory than any other event loop and is still faster than Event	2166	any other event loop and is still faster than Event natively).
1758	natively.
1759		2167
1760	The pure perl implementation is hit in a few sweet spots (both the	2168	The pure perl implementation is hit in a few sweet spots (both the
1761	constant timeout and the use of a single fd hit optimisations in the perl	2169	constant timeout and the use of a single fd hit optimisations in the perl
1762	interpreter and the backend itself). Nevertheless this shows that it	2170	interpreter and the backend itself). Nevertheless this shows that it
1763	adds very little overhead in itself. Like any select-based backend its	2171	adds very little overhead in itself. Like any select-based backend its
…		…
1837	In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100	2245	In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100
1838	(1%) are active. This mirrors the activity of large servers with many	2246	(1%) are active. This mirrors the activity of large servers with many
1839	connections, most of which are idle at any one point in time.	2247	connections, most of which are idle at any one point in time.
1840		2248
1841	Source code for this benchmark is found as F<eg/bench2> in the AnyEvent	2249	Source code for this benchmark is found as F<eg/bench2> in the AnyEvent
1842	distribution.	2250	distribution. It uses the L<AE> interface, which makes a real difference
		2251	for the EV and Perl backends only.
1843		2252
1844	=head3 Explanation of the columns	2253	=head3 Explanation of the columns
1845		2254
1846	I<sockets> is the number of sockets, and twice the number of "servers" (as	2255	I<sockets> is the number of sockets, and twice the number of "servers" (as
1847	each server has a read and write socket end).	2256	each server has a read and write socket end).
…		…
1855	a new one that moves the timeout into the future.	2264	a new one that moves the timeout into the future.
1856		2265
1857	=head3 Results	2266	=head3 Results
1858		2267
1859	name sockets create request	2268	name sockets create request
1860	EV 20000 69.01 11.16	2269	EV 20000 62.66 7.99
1861	Perl 20000 73.32 35.87	2270	Perl 20000 68.32 32.64
1862	IOAsync 20000 157.00 98.14 epoll	2271	IOAsync 20000 174.06 101.15 epoll
1863	IOAsync 20000 159.31 616.06 poll	2272	IOAsync 20000 174.67 610.84 poll
1864	Event 20000 212.62 257.32	2273	Event 20000 202.69 242.91
1865	Glib 20000 651.16 1896.30	2274	Glib 20000 557.01 1689.52
1866	POE 20000 349.67 12317.24 uses POE::Loop::Event	2275	POE 20000 341.54 12086.32 uses POE::Loop::Event
1867		2276
1868	=head3 Discussion	2277	=head3 Discussion
1869		2278
1870	This benchmark I<does> measure scalability and overall performance of the	2279	This benchmark I<does> measure scalability and overall performance of the
1871	particular event loop.	2280	particular event loop.
…		…
1997	As you can see, the AnyEvent + EV combination even beats the	2406	As you can see, the AnyEvent + EV combination even beats the
1998	hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl	2407	hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl
1999	backend easily beats IO::Lambda and POE.	2408	backend easily beats IO::Lambda and POE.
2000		2409
2001	And even the 100% non-blocking version written using the high-level (and	2410	And even the 100% non-blocking version written using the high-level (and
2002	slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda by a	2411	slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda
2003	large margin, even though it does all of DNS, tcp-connect and socket I/O	2412	higher level ("unoptimised") abstractions by a large margin, even though
2004	in a non-blocking way.	2413	it does all of DNS, tcp-connect and socket I/O in a non-blocking way.
2005		2414
2006	The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and	2415	The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and
2007	F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are	2416	F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are
2008	part of the IO::lambda distribution and were used without any changes.	2417	part of the IO::Lambda distribution and were used without any changes.
2009		2418
2010		2419
2011	=head1 SIGNALS	2420	=head1 SIGNALS
2012		2421
2013	AnyEvent currently installs handlers for these signals:	2422	AnyEvent currently installs handlers for these signals:
…		…
2018		2427
2019	A handler for C<SIGCHLD> is installed by AnyEvent's child watcher	2428	A handler for C<SIGCHLD> is installed by AnyEvent's child watcher
2020	emulation for event loops that do not support them natively. Also, some	2429	emulation for event loops that do not support them natively. Also, some
2021	event loops install a similar handler.	2430	event loops install a similar handler.
2022		2431
2023	If, when AnyEvent is loaded, SIGCHLD is set to IGNORE, then AnyEvent will	2432	Additionally, when AnyEvent is loaded and SIGCHLD is set to IGNORE, then
2024	reset it to default, to avoid losing child exit statuses.	2433	AnyEvent will reset it to default, to avoid losing child exit statuses.
2025		2434
2026	=item SIGPIPE	2435	=item SIGPIPE
2027		2436
2028	A no-op handler is installed for C<SIGPIPE> when C<$SIG{PIPE}> is C<undef>	2437	A no-op handler is installed for C<SIGPIPE> when C<$SIG{PIPE}> is C<undef>
2029	when AnyEvent gets loaded.	2438	when AnyEvent gets loaded.
…		…
2047	if $SIG{CHLD} eq 'IGNORE';	2456	if $SIG{CHLD} eq 'IGNORE';
2048		2457
2049	$SIG{PIPE} = sub { }	2458	$SIG{PIPE} = sub { }
2050	unless defined $SIG{PIPE};	2459	unless defined $SIG{PIPE};
2051		2460
		2461	=head1 RECOMMENDED/OPTIONAL MODULES
		2462
		2463	One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and
		2464	it's built-in modules) are required to use it.
		2465
		2466	That does not mean that AnyEvent won't take advantage of some additional
		2467	modules if they are installed.
		2468
		2469	This section explains which additional modules will be used, and how they
		2470	affect AnyEvent's operation.
		2471
		2472	=over 4
		2473
		2474	=item L<Async::Interrupt>
		2475
		2476	This slightly arcane module is used to implement fast signal handling: To
		2477	my knowledge, there is no way to do completely race-free and quick
		2478	signal handling in pure perl. To ensure that signals still get
		2479	delivered, AnyEvent will start an interval timer to wake up perl (and
		2480	catch the signals) with some delay (default is 10 seconds, look for
		2481	C<$AnyEvent::MAX_SIGNAL_LATENCY>).
		2482
		2483	If this module is available, then it will be used to implement signal
		2484	catching, which means that signals will not be delayed, and the event loop
		2485	will not be interrupted regularly, which is more efficient (and good for
		2486	battery life on laptops).
		2487
		2488	This affects not just the pure-perl event loop, but also other event loops
		2489	that have no signal handling on their own (e.g. Glib, Tk, Qt).
		2490
		2491	Some event loops (POE, Event, Event::Lib) offer signal watchers natively,
		2492	and either employ their own workarounds (POE) or use AnyEvent's workaround
		2493	(using C<$AnyEvent::MAX_SIGNAL_LATENCY>). Installing L<Async::Interrupt>
		2494	does nothing for those backends.
		2495
		2496	=item L<EV>
		2497
		2498	This module isn't really "optional", as it is simply one of the backend
		2499	event loops that AnyEvent can use. However, it is simply the best event
		2500	loop available in terms of features, speed and stability: It supports
		2501	the AnyEvent API optimally, implements all the watcher types in XS, does
		2502	automatic timer adjustments even when no monotonic clock is available,
		2503	can take avdantage of advanced kernel interfaces such as C<epoll> and
		2504	C<kqueue>, and is the fastest backend I<by far>. You can even embed
		2505	L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>).
		2506
		2507	=item L<Guard>
		2508
		2509	The guard module, when used, will be used to implement
		2510	C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a
		2511	lot less memory), but otherwise doesn't affect guard operation much. It is
		2512	purely used for performance.
		2513
		2514	=item L<JSON> and L<JSON::XS>
		2515
		2516	One of these modules is required when you want to read or write JSON data
		2517	via L<AnyEvent::Handle>. It is also written in pure-perl, but can take
		2518	advantage of the ultra-high-speed L<JSON::XS> module when it is installed.
		2519
		2520	In fact, L<AnyEvent::Handle> will use L<JSON::XS> by default if it is
		2521	installed.
		2522
		2523	=item L<Net::SSLeay>
		2524
		2525	Implementing TLS/SSL in Perl is certainly interesting, but not very
		2526	worthwhile: If this module is installed, then L<AnyEvent::Handle> (with
		2527	the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL.
		2528
		2529	=item L<Time::HiRes>
		2530
		2531	This module is part of perl since release 5.008. It will be used when the
		2532	chosen event library does not come with a timing source on it's own. The
		2533	pure-perl event loop (L<AnyEvent::Impl::Perl>) will additionally use it to
		2534	try to use a monotonic clock for timing stability.
		2535
		2536	=back
		2537
		2538
2052	=head1 FORK	2539	=head1 FORK
2053		2540
2054	Most event libraries are not fork-safe. The ones who are usually are	2541	Most event libraries are not fork-safe. The ones who are usually are
2055	because they rely on inefficient but fork-safe C<select> or C<poll>	2542	because they rely on inefficient but fork-safe C<select> or C<poll> calls
2056	calls. Only L<EV> is fully fork-aware.	2543	- higher performance APIs such as BSD's kqueue or the dreaded Linux epoll
		2544	are usually badly thought-out hacks that are incompatible with fork in
		2545	one way or another. Only L<EV> is fully fork-aware and ensures that you
		2546	continue event-processing in both parent and child (or both, if you know
		2547	what you are doing).
		2548
		2549	This means that, in general, you cannot fork and do event processing in
		2550	the child if the event library was initialised before the fork (which
		2551	usually happens when the first AnyEvent watcher is created, or the library
		2552	is loaded).
2057		2553
2058	If you have to fork, you must either do so I<before> creating your first	2554	If you have to fork, you must either do so I<before> creating your first
2059	watcher OR you must not use AnyEvent at all in the child.	2555	watcher OR you must not use AnyEvent at all in the child OR you must do
		2556	something completely out of the scope of AnyEvent.
		2557
		2558	The problem of doing event processing in the parent I<and> the child
		2559	is much more complicated: even for backends that I<are> fork-aware or
		2560	fork-safe, their behaviour is not usually what you want: fork clones all
		2561	watchers, that means all timers, I/O watchers etc. are active in both
		2562	parent and child, which is almost never what you want. USing C<exec>
		2563	to start worker children from some kind of manage rprocess is usually
		2564	preferred, because it is much easier and cleaner, at the expense of having
		2565	to have another binary.
2060		2566
2061		2567
2062	=head1 SECURITY CONSIDERATIONS	2568	=head1 SECURITY CONSIDERATIONS
2063		2569
2064	AnyEvent can be forced to load any event model via	2570	AnyEvent can be forced to load any event model via
…		…
2102	L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.	2608	L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.
2103		2609
2104	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,	2610	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,
2105	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,	2611	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,
2106	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,	2612	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,
2107	L<AnyEvent::Impl::POE>.	2613	L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>, L<Anyevent::Impl::Irssi>.
2108		2614
2109	Non-blocking file handles, sockets, TCP clients and	2615	Non-blocking file handles, sockets, TCP clients and
2110	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>.	2616	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.
2111		2617
2112	Asynchronous DNS: L<AnyEvent::DNS>.	2618	Asynchronous DNS: L<AnyEvent::DNS>.
2113		2619
2114	Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>,	2620	Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>,
		2621	L<Coro::Event>,
2115		2622
2116	Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>, L<AnyEvent::DNS>.	2623	Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::XMPP>,
		2624	L<AnyEvent::HTTP>.
2117		2625
2118		2626
2119	=head1 AUTHOR	2627	=head1 AUTHOR
2120		2628
2121	Marc Lehmann <schmorp@schmorp.de>	2629	Marc Lehmann <schmorp@schmorp.de>

Diff Legend

–	Removed lines
+	Added lines
<	Changed lines
>	Changed lines