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Revision 1.298 by root, Tue Nov 24 05:48:06 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, see below) to	195	C<fh> is the Perl I<file handle> (or a naked file descriptor) to watch
182	watch for events (AnyEvent might or might not keep a reference to this	196	for events (AnyEvent might or might not keep a reference to this file
183	file 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.
187		201
188	C<poll> must be a string that is either C<r> or C<w>, which creates a	202	C<poll> must be a string that is either C<r> or C<w>, which creates a
…		…
209	chomp (my $input = <STDIN>);	223	chomp (my $input = <STDIN>);
210	warn "read: $input\n";	224	warn "read: $input\n";
211	undef $w;	225	undef $w;
212	});	226	});
213		227
214	=head3 GETTING A FILE HANDLE FROM A FILE DESCRIPTOR
215
216	It is not uncommon to only have a file descriptor, while AnyEvent requires
217	a Perl file handle.
218
219	There are basically two methods to convert a file descriptor into a file handle. If you own
220	the file descriptor, you can open it with C<&=>, as in:
221
222	open my $fh, "<&=$fileno" or die "xxx: §!";
223
224	This will "own" the file descriptor, meaning that when C<$fh> is
225	destroyed, it will automatically close the C<$fileno>. Also, note that
226	the open mode (read, write, read/write) must correspond with how the
227	underlying file descriptor was opened.
228
229	In many cases, taking over the file descriptor is now what you want, in
230	which case the only alternative is to dup the file descriptor:
231
232	open my $fh, "<&$fileno" or die "xxx: $!";
233
234	This has the advantage of not closing the file descriptor and the
235	disadvantage of making a slow copy.
236
237	=head2 TIME WATCHERS	228	=head2 TIME WATCHERS
		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	);
238		237
239	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 >>
240	method with the following mandatory arguments:	239	method with the following mandatory arguments:
241		240
242	C<after> specifies after how many seconds (fractional values are	241	C<after> specifies after how many seconds (fractional values are
…		…
364	might affect timers and time-outs.	363	might affect timers and time-outs.
365		364
366	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
367	event loop's idea of "current time".	366	event loop's idea of "current time".
368		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
369	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.
370		376
371	=back	377	=back
372		378
373	=head2 SIGNAL WATCHERS	379	=head2 SIGNAL WATCHERS
		380
		381	$w = AnyEvent->signal (signal => <uppercase_signal_name>, cb => <callback>);
374		382
375	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
376	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
377	callback to be invoked whenever a signal occurs.	385	callback to be invoked whenever a signal occurs.
378		386
…		…
384	invocation, and callback invocation will be synchronous. Synchronous means	392	invocation, and callback invocation will be synchronous. Synchronous means
385	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,
386	but it is guaranteed not to interrupt any other callbacks.	394	but it is guaranteed not to interrupt any other callbacks.
387		395
388	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
389	between multiple watchers.	397	between multiple watchers, and AnyEvent will ensure that signals will not
		398	interrupt your program at bad times.
390		399
391	This watcher might use C<%SIG>, so programs overwriting those signals	400	This watcher might use C<%SIG> (depending on the event loop used),
392	directly will likely not work correctly.	401	so programs overwriting those signals directly will likely not work
		402	correctly.
393		403
394	Example: exit on SIGINT	404	Example: exit on SIGINT
395		405
396	my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });	406	my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });
397		407
		408	=head3 Restart Behaviour
		409
		410	While restart behaviour is up to the event loop implementation, most will
		411	not restart syscalls (that includes L<Async::Interrupt> and AnyEvent's
		412	pure perl implementation).
		413
		414	=head3 Safe/Unsafe Signals
		415
		416	Perl signals can be either "safe" (synchronous to opcode handling) or
		417	"unsafe" (asynchronous) - the former might get delayed indefinitely, the
		418	latter might corrupt your memory.
		419
		420	AnyEvent signal handlers are, in addition, synchronous to the event loop,
		421	i.e. they will not interrupt your running perl program but will only be
		422	called as part of the normal event handling (just like timer, I/O etc.
		423	callbacks, too).
		424
		425	=head3 Signal Races, Delays and Workarounds
		426
		427	Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support attaching
		428	callbacks to signals in a generic way, which is a pity, as you cannot
		429	do race-free signal handling in perl, requiring C libraries for
		430	this. AnyEvent will try to do it's best, which means in some cases,
		431	signals will be delayed. The maximum time a signal might be delayed is
		432	specified in C<$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
398	=head2 CHILD PROCESS WATCHERS	445	=head2 CHILD PROCESS WATCHERS
399		446
		447	$w = AnyEvent->child (pid => <process id>, cb => <callback>);
		448
400	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.
401		450
402	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,
403	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
404	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
405	any trace events (stopped/continued).	454	finished and an exit status is available, not on any trace events
		455	(stopped/continued).
406		456
407	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
408	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
409	callback arguments.	459	callback arguments.
410		460
…		…
426		476
427	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
428	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
429	watcher before you C<fork> the child (alternatively, you can call	479	watcher before you C<fork> the child (alternatively, you can call
430	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.
431		485
432	Example: fork a process and wait for it	486	Example: fork a process and wait for it
433		487
434	my $done = AnyEvent->condvar;	488	my $done = AnyEvent->condvar;
435		489
…		…
447	# do something else, then wait for process exit	501	# do something else, then wait for process exit
448	$done->recv;	502	$done->recv;
449		503
450	=head2 IDLE WATCHERS	504	=head2 IDLE WATCHERS
451		505
		506	$w = AnyEvent->idle (cb => <callback>);
		507
452	Sometimes there is a need to do something, but it is not so important	508	Sometimes there is a need to do something, but it is not so important
453	to do it instantly, but only when there is nothing better to do. This	509	to do it instantly, but only when there is nothing better to do. This
454	"nothing better to do" is usually defined to be "no other events need	510	"nothing better to do" is usually defined to be "no other events need
455	attention by the event loop".	511	attention by the event loop".
456		512
…		…
482	});	538	});
483	});	539	});
484		540
485	=head2 CONDITION VARIABLES	541	=head2 CONDITION VARIABLES
486		542
		543	$cv = AnyEvent->condvar;
		544
		545	$cv->send (<list>);
		546	my @res = $cv->recv;
		547
487	If you are familiar with some event loops you will know that all of them	548	If you are familiar with some event loops you will know that all of them
488	require you to run some blocking "loop", "run" or similar function that	549	require you to run some blocking "loop", "run" or similar function that
489	will actively watch for new events and call your callbacks.	550	will actively watch for new events and call your callbacks.
490		551
491	AnyEvent is different, it expects somebody else to run the event loop and	552	AnyEvent is slightly different: it expects somebody else to run the event
492	will only block when necessary (usually when told by the user).	553	loop and will only block when necessary (usually when told by the user).
493		554
494	The instrument to do that is called a "condition variable", so called	555	The instrument to do that is called a "condition variable", so called
495	because they represent a condition that must become true.	556	because they represent a condition that must become true.
496		557
		558	Now is probably a good time to look at the examples further below.
		559
497	Condition variables can be created by calling the C<< AnyEvent->condvar	560	Condition variables can be created by calling the C<< AnyEvent->condvar
498	>> method, usually without arguments. The only argument pair allowed is	561	>> method, usually without arguments. The only argument pair allowed is
499
500	C<cb>, which specifies a callback to be called when the condition variable	562	C<cb>, which specifies a callback to be called when the condition variable
501	becomes true, with the condition variable as the first argument (but not	563	becomes true, with the condition variable as the first argument (but not
502	the results).	564	the results).
503		565
504	After creation, the condition variable is "false" until it becomes "true"	566	After creation, the condition variable is "false" until it becomes "true"
…		…
509	Condition variables are similar to callbacks, except that you can	571	Condition variables are similar to callbacks, except that you can
510	optionally wait for them. They can also be called merge points - points	572	optionally wait for them. They can also be called merge points - points
511	in time where multiple outstanding events have been processed. And yet	573	in time where multiple outstanding events have been processed. And yet
512	another way to call them is transactions - each condition variable can be	574	another way to call them is transactions - each condition variable can be
513	used to represent a transaction, which finishes at some point and delivers	575	used to represent a transaction, which finishes at some point and delivers
514	a result.	576	a result. And yet some people know them as "futures" - a promise to
		577	compute/deliver something that you can wait for.
515		578
516	Condition variables are very useful to signal that something has finished,	579	Condition variables are very useful to signal that something has finished,
517	for example, if you write a module that does asynchronous http requests,	580	for example, if you write a module that does asynchronous http requests,
518	then a condition variable would be the ideal candidate to signal the	581	then a condition variable would be the ideal candidate to signal the
519	availability of results. The user can either act when the callback is	582	availability of results. The user can either act when the callback is
…		…
553	after => 1,	616	after => 1,
554	cb => sub { $result_ready->send },	617	cb => sub { $result_ready->send },
555	);	618	);
556		619
557	# this "blocks" (while handling events) till the callback	620	# this "blocks" (while handling events) till the callback
558	# calls send	621	# calls ->send
559	$result_ready->recv;	622	$result_ready->recv;
560		623
561	Example: wait for a timer, but take advantage of the fact that	624	Example: wait for a timer, but take advantage of the fact that condition
562	condition variables are also code references.	625	variables are also callable directly.
563		626
564	my $done = AnyEvent->condvar;	627	my $done = AnyEvent->condvar;
565	my $delay = AnyEvent->timer (after => 5, cb => $done);	628	my $delay = AnyEvent->timer (after => 5, cb => $done);
566	$done->recv;	629	$done->recv;
567		630
…		…
573		636
574	...	637	...
575		638
576	my @info = $couchdb->info->recv;	639	my @info = $couchdb->info->recv;
577		640
578	And this is how you would just ste a callback to be called whenever the	641	And this is how you would just set a callback to be called whenever the
579	results are available:	642	results are available:
580		643
581	$couchdb->info->cb (sub {	644	$couchdb->info->cb (sub {
582	my @info = $_[0]->recv;	645	my @info = $_[0]->recv;
583	});	646	});
…		…
601	immediately from within send.	664	immediately from within send.
602		665
603	Any arguments passed to the C<send> call will be returned by all	666	Any arguments passed to the C<send> call will be returned by all
604	future C<< ->recv >> calls.	667	future C<< ->recv >> calls.
605		668
606	Condition variables are overloaded so one can call them directly	669	Condition variables are overloaded so one can call them directly (as if
607	(as a code reference). Calling them directly is the same as calling	670	they were a code reference). Calling them directly is the same as calling
608	C<send>. Note, however, that many C-based event loops do not handle	671	C<send>.
609	overloading, so as tempting as it may be, passing a condition variable
610	instead of a callback does not work. Both the pure perl and EV loops
611	support overloading, however, as well as all functions that use perl to
612	invoke a callback (as in L<AnyEvent::Socket> and L<AnyEvent::DNS> for
613	example).
614		672
615	=item $cv->croak ($error)	673	=item $cv->croak ($error)
616		674
617	Similar to send, but causes all call's to C<< ->recv >> to invoke	675	Similar to send, but causes all call's to C<< ->recv >> to invoke
618	C<Carp::croak> with the given error message/object/scalar.	676	C<Carp::croak> with the given error message/object/scalar.
619		677
620	This can be used to signal any errors to the condition variable	678	This can be used to signal any errors to the condition variable
621	user/consumer.	679	user/consumer. Doing it this way instead of calling C<croak> directly
		680	delays the error detetcion, but has the overwhelmign advantage that it
		681	diagnoses the error at the place where the result is expected, and not
		682	deep in some event clalback without connection to the actual code causing
		683	the problem.
622		684
623	=item $cv->begin ([group callback])	685	=item $cv->begin ([group callback])
624		686
625	=item $cv->end	687	=item $cv->end
626		688
…		…
628	one. For example, a function that pings many hosts in parallel might want	690	one. For example, a function that pings many hosts in parallel might want
629	to use a condition variable for the whole process.	691	to use a condition variable for the whole process.
630		692
631	Every call to C<< ->begin >> will increment a counter, and every call to	693	Every call to C<< ->begin >> will increment a counter, and every call to
632	C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end	694	C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end
633	>>, the (last) callback passed to C<begin> will be executed. That callback	695	>>, the (last) callback passed to C<begin> will be executed, passing the
634	is I<supposed> to call C<< ->send >>, but that is not required. If no	696	condvar as first argument. That callback is I<supposed> to call C<< ->send
635	callback was set, C<send> will be called without any arguments.	697	>>, but that is not required. If no group callback was set, C<send> will
		698	be called without any arguments.
636		699
637	You can think of C<< $cv->send >> giving you an OR condition (one call	700	You can think of C<< $cv->send >> giving you an OR condition (one call
638	sends), while C<< $cv->begin >> and C<< $cv->end >> giving you an AND	701	sends), while C<< $cv->begin >> and C<< $cv->end >> giving you an AND
639	condition (all C<begin> calls must be C<end>'ed before the condvar sends).	702	condition (all C<begin> calls must be C<end>'ed before the condvar sends).
640		703
…		…
667	begung can potentially be zero:	730	begung can potentially be zero:
668		731
669	my $cv = AnyEvent->condvar;	732	my $cv = AnyEvent->condvar;
670		733
671	my %result;	734	my %result;
672	$cv->begin (sub { $cv->send (\%result) });	735	$cv->begin (sub { shift->send (\%result) });
673		736
674	for my $host (@list_of_hosts) {	737	for my $host (@list_of_hosts) {
675	$cv->begin;	738	$cv->begin;
676	ping_host_then_call_callback $host, sub {	739	ping_host_then_call_callback $host, sub {
677	$result{$host} = ...;	740	$result{$host} = ...;
…		…
722	function will call C<croak>.	785	function will call C<croak>.
723		786
724	In list context, all parameters passed to C<send> will be returned,	787	In list context, all parameters passed to C<send> will be returned,
725	in scalar context only the first one will be returned.	788	in scalar context only the first one will be returned.
726		789
		790	Note that doing a blocking wait in a callback is not supported by any
		791	event loop, that is, recursive invocation of a blocking C<< ->recv
		792	>> is not allowed, and the C<recv> call will C<croak> if such a
		793	condition is detected. This condition can be slightly loosened by using
		794	L<Coro::AnyEvent>, which allows you to do a blocking C<< ->recv >> from
		795	any thread that doesn't run the event loop itself.
		796
727	Not all event models support a blocking wait - some die in that case	797	Not all event models support a blocking wait - some die in that case
728	(programs might want to do that to stay interactive), so I<if you are	798	(programs might want to do that to stay interactive), so I<if you are
729	using this from a module, never require a blocking wait>, but let the	799	using this from a module, never require a blocking wait>. Instead, let the
730	caller decide whether the call will block or not (for example, by coupling	800	caller decide whether the call will block or not (for example, by coupling
731	condition variables with some kind of request results and supporting	801	condition variables with some kind of request results and supporting
732	callbacks so the caller knows that getting the result will not block,	802	callbacks so the caller knows that getting the result will not block,
733	while still supporting blocking waits if the caller so desires).	803	while still supporting blocking waits if the caller so desires).
734		804
735	Another reason I<never> to C<< ->recv >> in a module is that you cannot
736	sensibly have two C<< ->recv >>'s in parallel, as that would require
737	multiple interpreters or coroutines/threads, none of which C<AnyEvent>
738	can supply.
739
740	The L<Coro> module, however, I<can> and I<does> supply coroutines and, in
741	fact, L<Coro::AnyEvent> replaces AnyEvent's condvars by coroutine-safe
742	versions and also integrates coroutines into AnyEvent, making blocking
743	C<< ->recv >> calls perfectly safe as long as they are done from another
744	coroutine (one that doesn't run the event loop).
745
746	You can ensure that C<< -recv >> never blocks by setting a callback and	805	You can ensure that C<< -recv >> never blocks by setting a callback and
747	only calling C<< ->recv >> from within that callback (or at a later	806	only calling C<< ->recv >> from within that callback (or at a later
748	time). This will work even when the event loop does not support blocking	807	time). This will work even when the event loop does not support blocking
749	waits otherwise.	808	waits otherwise.
750		809
…		…
756	=item $cb = $cv->cb ($cb->($cv))	815	=item $cb = $cv->cb ($cb->($cv))
757		816
758	This is a mutator function that returns the callback set and optionally	817	This is a mutator function that returns the callback set and optionally
759	replaces it before doing so.	818	replaces it before doing so.
760		819
761	The callback will be called when the condition becomes "true", i.e. when	820	The callback will be called when the condition becomes (or already was)
762	C<send> or C<croak> are called, with the only argument being the condition	821	"true", i.e. when C<send> or C<croak> are called (or were called), with
763	variable itself. Calling C<recv> inside the callback or at any later time	822	the only argument being the condition variable itself. Calling C<recv>
764	is guaranteed not to block.	823	inside the callback or at any later time is guaranteed not to block.
765		824
766	=back	825	=back
767		826
		827	=head1 SUPPORTED EVENT LOOPS/BACKENDS
		828
		829	The available backend classes are (every class has its own manpage):
		830
		831	=over 4
		832
		833	=item Backends that are autoprobed when no other event loop can be found.
		834
		835	EV is the preferred backend when no other event loop seems to be in
		836	use. If EV is not installed, then AnyEvent will fall back to its own
		837	pure-perl implementation, which is available everywhere as it comes with
		838	AnyEvent itself.
		839
		840	AnyEvent::Impl::EV based on EV (interface to libev, best choice).
		841	AnyEvent::Impl::Perl pure-perl implementation, fast and portable.
		842
		843	=item Backends that are transparently being picked up when they are used.
		844
		845	These will be used when they are currently loaded when the first watcher
		846	is created, in which case it is assumed that the application is using
		847	them. This means that AnyEvent will automatically pick the right backend
		848	when the main program loads an event module before anything starts to
		849	create watchers. Nothing special needs to be done by the main program.
		850
		851	AnyEvent::Impl::Event based on Event, very stable, few glitches.
		852	AnyEvent::Impl::Glib based on Glib, slow but very stable.
		853	AnyEvent::Impl::Tk based on Tk, very broken.
		854	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
		855	AnyEvent::Impl::POE based on POE, very slow, some limitations.
		856	AnyEvent::Impl::Irssi used when running within irssi.
		857
		858	=item Backends with special needs.
		859
		860	Qt requires the Qt::Application to be instantiated first, but will
		861	otherwise be picked up automatically. As long as the main program
		862	instantiates the application before any AnyEvent watchers are created,
		863	everything should just work.
		864
		865	AnyEvent::Impl::Qt based on Qt.
		866
		867	Support for IO::Async can only be partial, as it is too broken and
		868	architecturally limited to even support the AnyEvent API. It also
		869	is the only event loop that needs the loop to be set explicitly, so
		870	it can only be used by a main program knowing about AnyEvent. See
		871	L<AnyEvent::Impl::Async> for the gory details.
		872
		873	AnyEvent::Impl::IOAsync based on IO::Async, cannot be autoprobed.
		874
		875	=item Event loops that are indirectly supported via other backends.
		876
		877	Some event loops can be supported via other modules:
		878
		879	There is no direct support for WxWidgets (L<Wx>) or L<Prima>.
		880
		881	B<WxWidgets> has no support for watching file handles. However, you can
		882	use WxWidgets through the POE adaptor, as POE has a Wx backend that simply
		883	polls 20 times per second, which was considered to be too horrible to even
		884	consider for AnyEvent.
		885
		886	B<Prima> is not supported as nobody seems to be using it, but it has a POE
		887	backend, so it can be supported through POE.
		888
		889	AnyEvent knows about both L<Prima> and L<Wx>, however, and will try to
		890	load L<POE> when detecting them, in the hope that POE will pick them up,
		891	in which case everything will be automatic.
		892
		893	=back
		894
768	=head1 GLOBAL VARIABLES AND FUNCTIONS	895	=head1 GLOBAL VARIABLES AND FUNCTIONS
769		896
		897	These are not normally required to use AnyEvent, but can be useful to
		898	write AnyEvent extension modules.
		899
770	=over 4	900	=over 4
771		901
772	=item $AnyEvent::MODEL	902	=item $AnyEvent::MODEL
773		903
774	Contains C<undef> until the first watcher is being created. Then it	904	Contains C<undef> until the first watcher is being created, before the
		905	backend has been autodetected.
		906
775	contains the event model that is being used, which is the name of the	907	Afterwards it contains the event model that is being used, which is the
776	Perl class implementing the model. This class is usually one of the	908	name of the Perl class implementing the model. This class is usually one
777	C<AnyEvent::Impl:xxx> modules, but can be any other class in the case	909	of the C<AnyEvent::Impl:xxx> modules, but can be any other class in the
778	AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode>).	910	case AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode> it
779		911	will be C<urxvt::anyevent>).
780	The known classes so far are:
781
782	AnyEvent::Impl::EV based on EV (an interface to libev, best choice).
783	AnyEvent::Impl::Event based on Event, second best choice.
784	AnyEvent::Impl::Perl pure-perl implementation, fast and portable.
785	AnyEvent::Impl::Glib based on Glib, third-best choice.
786	AnyEvent::Impl::Tk based on Tk, very bad choice.
787	AnyEvent::Impl::Qt based on Qt, cannot be autoprobed (see its docs).
788	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
789	AnyEvent::Impl::POE based on POE, not generic enough for full support.
790
791	# warning, support for IO::Async is only partial, as it is too broken
792	# and limited toe ven support the AnyEvent API. See AnyEvent::Impl::Async.
793	AnyEvent::Impl::IOAsync based on IO::Async, cannot be autoprobed (see its docs).
794
795	There is no support for WxWidgets, as WxWidgets has no support for
796	watching file handles. However, you can use WxWidgets through the
797	POE Adaptor, as POE has a Wx backend that simply polls 20 times per
798	second, which was considered to be too horrible to even consider for
799	AnyEvent. Likewise, other POE backends can be used by AnyEvent by using
800	it's adaptor.
801
802	AnyEvent knows about L<Prima> and L<Wx> and will try to use L<POE> when
803	autodetecting them.
804		912
805	=item AnyEvent::detect	913	=item AnyEvent::detect
806		914
807	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model	915	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model
808	if necessary. You should only call this function right before you would	916	if necessary. You should only call this function right before you would
809	have created an AnyEvent watcher anyway, that is, as late as possible at	917	have created an AnyEvent watcher anyway, that is, as late as possible at
810	runtime.	918	runtime, and not e.g. while initialising of your module.
		919
		920	If you need to do some initialisation before AnyEvent watchers are
		921	created, use C<post_detect>.
811		922
812	=item $guard = AnyEvent::post_detect { BLOCK }	923	=item $guard = AnyEvent::post_detect { BLOCK }
813		924
814	Arranges for the code block to be executed as soon as the event model is	925	Arranges for the code block to be executed as soon as the event model is
815	autodetected (or immediately if this has already happened).	926	autodetected (or immediately if this has already happened).
816		927
		928	The block will be executed I<after> the actual backend has been detected
		929	(C<$AnyEvent::MODEL> is set), but I<before> any watchers have been
		930	created, so it is possible to e.g. patch C<@AnyEvent::ISA> or do
		931	other initialisations - see the sources of L<AnyEvent::Strict> or
		932	L<AnyEvent::AIO> to see how this is used.
		933
		934	The most common usage is to create some global watchers, without forcing
		935	event module detection too early, for example, L<AnyEvent::AIO> creates
		936	and installs the global L<IO::AIO> watcher in a C<post_detect> block to
		937	avoid autodetecting the event module at load time.
		938
817	If called in scalar or list context, then it creates and returns an object	939	If called in scalar or list context, then it creates and returns an object
818	that automatically removes the callback again when it is destroyed. See	940	that automatically removes the callback again when it is destroyed (or
		941	C<undef> when the hook was immediately executed). See L<AnyEvent::AIO> for
819	L<Coro::BDB> for a case where this is useful.	942	a case where this is useful.
		943
		944	Example: Create a watcher for the IO::AIO module and store it in
		945	C<$WATCHER>. Only do so after the event loop is initialised, though.
		946
		947	our WATCHER;
		948
		949	my $guard = AnyEvent::post_detect {
		950	$WATCHER = AnyEvent->io (fh => IO::AIO::poll_fileno, poll => 'r', cb => \&IO::AIO::poll_cb);
		951	};
		952
		953	# the ||= is important in case post_detect immediately runs the block,
		954	# as to not clobber the newly-created watcher. assigning both watcher and
		955	# post_detect guard to the same variable has the advantage of users being
		956	# able to just C<undef $WATCHER> if the watcher causes them grief.
		957
		958	$WATCHER ||= $guard;
820		959
821	=item @AnyEvent::post_detect	960	=item @AnyEvent::post_detect
822		961
823	If there are any code references in this array (you can C<push> to it	962	If there are any code references in this array (you can C<push> to it
824	before or after loading AnyEvent), then they will called directly after	963	before or after loading AnyEvent), then they will called directly after
825	the event loop has been chosen.	964	the event loop has been chosen.
826		965
827	You should check C<$AnyEvent::MODEL> before adding to this array, though:	966	You should check C<$AnyEvent::MODEL> before adding to this array, though:
828	if it contains a true value then the event loop has already been detected,	967	if it is defined then the event loop has already been detected, and the
829	and the array will be ignored.	968	array will be ignored.
830		969
831	Best use C<AnyEvent::post_detect { BLOCK }> instead.	970	Best use C<AnyEvent::post_detect { BLOCK }> when your application allows
		971	it,as it takes care of these details.
		972
		973	This variable is mainly useful for modules that can do something useful
		974	when AnyEvent is used and thus want to know when it is initialised, but do
		975	not need to even load it by default. This array provides the means to hook
		976	into AnyEvent passively, without loading it.
832		977
833	=back	978	=back
834		979
835	=head1 WHAT TO DO IN A MODULE	980	=head1 WHAT TO DO IN A MODULE
836		981
…		…
891		1036
892		1037
893	=head1 OTHER MODULES	1038	=head1 OTHER MODULES
894		1039
895	The following is a non-exhaustive list of additional modules that use	1040	The following is a non-exhaustive list of additional modules that use
896	AnyEvent and can therefore be mixed easily with other AnyEvent modules	1041	AnyEvent as a client and can therefore be mixed easily with other AnyEvent
897	in the same program. Some of the modules come with AnyEvent, some are	1042	modules and other event loops in the same program. Some of the modules
898	available via CPAN.	1043	come with AnyEvent, most are available via CPAN.
899		1044
900	=over 4	1045	=over 4
901		1046
902	=item L<AnyEvent::Util>	1047	=item L<AnyEvent::Util>
903		1048
…		…
912		1057
913	=item L<AnyEvent::Handle>	1058	=item L<AnyEvent::Handle>
914		1059
915	Provide read and write buffers, manages watchers for reads and writes,	1060	Provide read and write buffers, manages watchers for reads and writes,
916	supports raw and formatted I/O, I/O queued and fully transparent and	1061	supports raw and formatted I/O, I/O queued and fully transparent and
917	non-blocking SSL/TLS.	1062	non-blocking SSL/TLS (via L<AnyEvent::TLS>.
918		1063
919	=item L<AnyEvent::DNS>	1064	=item L<AnyEvent::DNS>
920		1065
921	Provides rich asynchronous DNS resolver capabilities.	1066	Provides rich asynchronous DNS resolver capabilities.
922		1067
…		…
950		1095
951	=item L<AnyEvent::GPSD>	1096	=item L<AnyEvent::GPSD>
952		1097
953	A non-blocking interface to gpsd, a daemon delivering GPS information.	1098	A non-blocking interface to gpsd, a daemon delivering GPS information.
954		1099
		1100	=item L<AnyEvent::IRC>
		1101
		1102	AnyEvent based IRC client module family (replacing the older Net::IRC3).
		1103
		1104	=item L<AnyEvent::XMPP>
		1105
		1106	AnyEvent based XMPP (Jabber protocol) module family (replacing the older
		1107	Net::XMPP2>.
		1108
955	=item L<AnyEvent::IGS>	1109	=item L<AnyEvent::IGS>
956		1110
957	A non-blocking interface to the Internet Go Server protocol (used by	1111	A non-blocking interface to the Internet Go Server protocol (used by
958	L<App::IGS>).	1112	L<App::IGS>).
959		1113
960	=item L<AnyEvent::IRC>
961
962	AnyEvent based IRC client module family (replacing the older Net::IRC3).
963
964	=item L<Net::XMPP2>
965
966	AnyEvent based XMPP (Jabber protocol) module family.
967
968	=item L<Net::FCP>	1114	=item L<Net::FCP>
969		1115
970	AnyEvent-based implementation of the Freenet Client Protocol, birthplace	1116	AnyEvent-based implementation of the Freenet Client Protocol, birthplace
971	of AnyEvent.	1117	of AnyEvent.
972		1118
…		…
976		1122
977	=item L<Coro>	1123	=item L<Coro>
978		1124
979	Has special support for AnyEvent via L<Coro::AnyEvent>.	1125	Has special support for AnyEvent via L<Coro::AnyEvent>.
980		1126
981	=item L<IO::Lambda>
982
983	The lambda approach to I/O - don't ask, look there. Can use AnyEvent.
984
985	=back	1127	=back
986		1128
987	=cut	1129	=cut
988		1130
989	package AnyEvent;	1131	package AnyEvent;
990		1132
991	no warnings;	1133	# basically a tuned-down version of common::sense
		1134	sub common_sense {
		1135	# from common:.sense 1.0
		1136	${^WARNING_BITS} = "\xfc\x3f\xf3\x00\x0f\xf3\xcf\xc0\xf3\xfc\x33\x03";
992	use strict qw(vars subs);	1137	# use strict vars subs
		1138	$^H |= 0x00000600;
		1139	}
993		1140
		1141	BEGIN { AnyEvent::common_sense }
		1142
994	use Carp;	1143	use Carp ();
995		1144
996	our $VERSION = 4.8;	1145	our $VERSION = '5.21';
997	our $MODEL;	1146	our $MODEL;
998		1147
999	our $AUTOLOAD;	1148	our $AUTOLOAD;
1000	our @ISA;	1149	our @ISA;
1001		1150
1002	our @REGISTRY;	1151	our @REGISTRY;
1003		1152
1004	our $WIN32;	1153	our $VERBOSE;
1005		1154
1006	BEGIN {	1155	BEGIN {
1007	eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }";	1156	eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }";
1008	eval "sub TAINT(){ " . (${^TAINT}*1) . " }";	1157	eval "sub TAINT(){ " . (${^TAINT}*1) . " }";
1009		1158
1010	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}	1159	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}
1011	if ${^TAINT};	1160	if ${^TAINT};
1012	}
1013		1161
1014	our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1;	1162	$VERBOSE = $ENV{PERL_ANYEVENT_VERBOSE}*1;
		1163
		1164	}
		1165
		1166	our $MAX_SIGNAL_LATENCY = 10;
1015		1167
1016	our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred	1168	our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred
1017		1169
1018	{	1170	{
1019	my $idx;	1171	my $idx;
…		…
1021	for reverse split /\s*,\s*/,	1173	for reverse split /\s*,\s*/,
1022	$ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";	1174	$ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";
1023	}	1175	}
1024		1176
1025	my @models = (	1177	my @models = (
1026	[EV:: => AnyEvent::Impl::EV::],	1178	[EV:: => AnyEvent::Impl::EV:: , 1],
1027	[Event:: => AnyEvent::Impl::Event::],
1028	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::],	1179	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl:: , 1],
1029	# everything below here will not be autoprobed	1180	# everything below here will not (normally) be autoprobed
1030	# as the pureperl backend should work everywhere	1181	# as the pureperl backend should work everywhere
1031	# and is usually faster	1182	# and is usually faster
		1183	[Event:: => AnyEvent::Impl::Event::, 1],
		1184	[Glib:: => AnyEvent::Impl::Glib:: , 1], # becomes extremely slow with many watchers
		1185	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
		1186	[Irssi:: => AnyEvent::Impl::Irssi::], # Irssi has a bogus "Event" package
1032	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles	1187	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
1033	[Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers
1034	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
1035	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program	1188	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program
1036	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza	1189	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
1037	[Wx:: => AnyEvent::Impl::POE::],	1190	[Wx:: => AnyEvent::Impl::POE::],
1038	[Prima:: => AnyEvent::Impl::POE::],	1191	[Prima:: => AnyEvent::Impl::POE::],
1039	# IO::Async is just too broken - we would need workaorunds for its	1192	# IO::Async is just too broken - we would need workarounds for its
1040	# byzantine signal and broken child handling, among others.	1193	# byzantine signal and broken child handling, among others.
1041	# IO::Async is rather hard to detect, as it doesn't have any	1194	# IO::Async is rather hard to detect, as it doesn't have any
1042	# obvious default class.	1195	# obvious default class.
1043	# [IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program	1196	[IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program
1044	# [IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program	1197	[IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program
1045	# [IO::Async::Notifier:: => AnyEvent::Impl::IOAsync::], # requires special main program	1198	[IO::Async::Notifier:: => AnyEvent::Impl::IOAsync::], # requires special main program
		1199	[AnyEvent::Impl::IOAsync:: => AnyEvent::Impl::IOAsync::], # requires special main program
1046	);	1200	);
1047		1201
1048	our %method = map +($_ => 1),	1202	our %method = map +($_ => 1),
1049	qw(io timer time now now_update signal child idle condvar one_event DESTROY);	1203	qw(io timer time now now_update signal child idle condvar one_event DESTROY);
1050		1204
…		…
1054	my ($cb) = @_;	1208	my ($cb) = @_;
1055		1209
1056	if ($MODEL) {	1210	if ($MODEL) {
1057	$cb->();	1211	$cb->();
1058		1212
1059	1	1213	undef
1060	} else {	1214	} else {
1061	push @post_detect, $cb;	1215	push @post_detect, $cb;
1062		1216
1063	defined wantarray	1217	defined wantarray
1064	? bless \$cb, "AnyEvent::Util::postdetect"	1218	? bless \$cb, "AnyEvent::Util::postdetect"
…		…
1070	@post_detect = grep $_ != ${$_[0]}, @post_detect;	1224	@post_detect = grep $_ != ${$_[0]}, @post_detect;
1071	}	1225	}
1072		1226
1073	sub detect() {	1227	sub detect() {
1074	unless ($MODEL) {	1228	unless ($MODEL) {
1075	no strict 'refs';
1076	local $SIG{__DIE__};	1229	local $SIG{__DIE__};
1077		1230
1078	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {	1231	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {
1079	my $model = "AnyEvent::Impl::$1";	1232	my $model = "AnyEvent::Impl::$1";
1080	if (eval "require $model") {	1233	if (eval "require $model") {
1081	$MODEL = $model;	1234	$MODEL = $model;
1082	warn "AnyEvent: loaded model '$model' (forced by \$PERL_ANYEVENT_MODEL), using it.\n" if $verbose > 1;	1235	warn "AnyEvent: loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.\n" if $VERBOSE >= 2;
1083	} else {	1236	} else {
1084	warn "AnyEvent: unable to load model '$model' (from \$PERL_ANYEVENT_MODEL):\n$@" if $verbose;	1237	warn "AnyEvent: unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@" if $VERBOSE;
1085	}	1238	}
1086	}	1239	}
1087		1240
1088	# check for already loaded models	1241	# check for already loaded models
1089	unless ($MODEL) {	1242	unless ($MODEL) {
1090	for (@REGISTRY, @models) {	1243	for (@REGISTRY, @models) {
1091	my ($package, $model) = @$_;	1244	my ($package, $model) = @$_;
1092	if (${"$package\::VERSION"} > 0) {	1245	if (${"$package\::VERSION"} > 0) {
1093	if (eval "require $model") {	1246	if (eval "require $model") {
1094	$MODEL = $model;	1247	$MODEL = $model;
1095	warn "AnyEvent: autodetected model '$model', using it.\n" if $verbose > 1;	1248	warn "AnyEvent: autodetected model '$model', using it.\n" if $VERBOSE >= 2;
1096	last;	1249	last;
1097	}	1250	}
1098	}	1251	}
1099	}	1252	}
1100		1253
1101	unless ($MODEL) {	1254	unless ($MODEL) {
1102	# try to load a model	1255	# try to autoload a model
1103
1104	for (@REGISTRY, @models) {	1256	for (@REGISTRY, @models) {
1105	my ($package, $model) = @$_;	1257	my ($package, $model, $autoload) = @$_;
		1258	if (
		1259	$autoload
1106	if (eval "require $package"	1260	and eval "require $package"
1107	and ${"$package\::VERSION"} > 0	1261	and ${"$package\::VERSION"} > 0
1108	and eval "require $model") {	1262	and eval "require $model"
		1263	) {
1109	$MODEL = $model;	1264	$MODEL = $model;
1110	warn "AnyEvent: autoprobed model '$model', using it.\n" if $verbose > 1;	1265	warn "AnyEvent: autoloaded model '$model', using it.\n" if $VERBOSE >= 2;
1111	last;	1266	last;
1112	}	1267	}
1113	}	1268	}
1114		1269
1115	$MODEL	1270	$MODEL
…		…
1131		1286
1132	sub AUTOLOAD {	1287	sub AUTOLOAD {
1133	(my $func = $AUTOLOAD) =~ s/.*://;	1288	(my $func = $AUTOLOAD) =~ s/.*://;
1134		1289
1135	$method{$func}	1290	$method{$func}
1136	or croak "$func: not a valid method for AnyEvent objects";	1291	or Carp::croak "$func: not a valid method for AnyEvent objects";
1137		1292
1138	detect unless $MODEL;	1293	detect unless $MODEL;
1139		1294
1140	my $class = shift;	1295	my $class = shift;
1141	$class->$func (@_);	1296	$class->$func (@_);
…		…
1146	# allow only one watcher per fd, so we dup it to get a different one).	1301	# allow only one watcher per fd, so we dup it to get a different one).
1147	sub _dupfh($$;$$) {	1302	sub _dupfh($$;$$) {
1148	my ($poll, $fh, $r, $w) = @_;	1303	my ($poll, $fh, $r, $w) = @_;
1149		1304
1150	# cygwin requires the fh mode to be matching, unix doesn't	1305	# cygwin requires the fh mode to be matching, unix doesn't
1151	my ($rw, $mode) = $poll eq "r" ? ($r, "<")	1306	my ($rw, $mode) = $poll eq "r" ? ($r, "<&") : ($w, ">&");
1152	: $poll eq "w" ? ($w, ">")
1153	: Carp::croak "AnyEvent->io requires poll set to either 'r' or 'w'";
1154		1307
1155	open my $fh2, "$mode&" . fileno $fh	1308	open my $fh2, $mode, $fh
1156	or die "cannot dup() filehandle: $!,";	1309	or die "AnyEvent->io: cannot dup() filehandle in mode '$poll': $!,";
1157		1310
1158	# we assume CLOEXEC is already set by perl in all important cases	1311	# we assume CLOEXEC is already set by perl in all important cases
1159		1312
1160	($fh2, $rw)	1313	($fh2, $rw)
1161	}	1314	}
1162		1315
		1316	=head1 SIMPLIFIED AE API
		1317
		1318	Starting with version 5.0, AnyEvent officially supports a second, much
		1319	simpler, API that is designed to reduce the calling, typing and memory
		1320	overhead.
		1321
		1322	See the L<AE> manpage for details.
		1323
		1324	=cut
		1325
		1326	package AE;
		1327
		1328	our $VERSION = $AnyEvent::VERSION;
		1329
		1330	sub io($$$) {
		1331	AnyEvent->io (fh => $_[0], poll => $_[1] ? "w" : "r", cb => $_[2])
		1332	}
		1333
		1334	sub timer($$$) {
		1335	AnyEvent->timer (after => $_[0], interval => $_[1], cb => $_[2])
		1336	}
		1337
		1338	sub signal($$) {
		1339	AnyEvent->signal (signal => $_[0], cb => $_[1])
		1340	}
		1341
		1342	sub child($$) {
		1343	AnyEvent->child (pid => $_[0], cb => $_[1])
		1344	}
		1345
		1346	sub idle($) {
		1347	AnyEvent->idle (cb => $_[0])
		1348	}
		1349
		1350	sub cv(;&) {
		1351	AnyEvent->condvar (@_ ? (cb => $_[0]) : ())
		1352	}
		1353
		1354	sub now() {
		1355	AnyEvent->now
		1356	}
		1357
		1358	sub now_update() {
		1359	AnyEvent->now_update
		1360	}
		1361
		1362	sub time() {
		1363	AnyEvent->time
		1364	}
		1365
1163	package AnyEvent::Base;	1366	package AnyEvent::Base;
1164		1367
1165	# default implementations for many methods	1368	# default implementations for many methods
1166		1369
1167	BEGIN {	1370	sub _time() {
		1371	# probe for availability of Time::HiRes
1168	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {	1372	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {
		1373	warn "AnyEvent: using Time::HiRes for sub-second timing accuracy.\n" if $VERBOSE >= 8;
1169	*_time = \&Time::HiRes::time;	1374	*_time = \&Time::HiRes::time;
1170	# if (eval "use POSIX (); (POSIX::times())...	1375	# if (eval "use POSIX (); (POSIX::times())...
1171	} else {	1376	} else {
		1377	warn "AnyEvent: using built-in time(), WARNING, no sub-second resolution!\n" if $VERBOSE;
1172	*_time = sub { time }; # epic fail	1378	*_time = sub { time }; # epic fail
1173	}	1379	}
		1380
		1381	&_time
1174	}	1382	}
1175		1383
1176	sub time { _time }	1384	sub time { _time }
1177	sub now { _time }	1385	sub now { _time }
1178	sub now_update { }	1386	sub now_update { }
…		…
1183	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"	1391	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"
1184	}	1392	}
1185		1393
1186	# default implementation for ->signal	1394	# default implementation for ->signal
1187		1395
		1396	our $HAVE_ASYNC_INTERRUPT;
		1397
		1398	sub _have_async_interrupt() {
		1399	$HAVE_ASYNC_INTERRUPT = 1*(!$ENV{PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT}
		1400	&& eval "use Async::Interrupt 1.02 (); 1")
		1401	unless defined $HAVE_ASYNC_INTERRUPT;
		1402
		1403	$HAVE_ASYNC_INTERRUPT
		1404	}
		1405
1188	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);	1406	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);
		1407	our (%SIG_ASY, %SIG_ASY_W);
		1408	our ($SIG_COUNT, $SIG_TW);
1189		1409
1190	sub _signal_exec {	1410	sub _signal_exec {
		1411	$HAVE_ASYNC_INTERRUPT
		1412	? $SIGPIPE_R->drain
1191	sysread $SIGPIPE_R, my $dummy, 4;	1413	: sysread $SIGPIPE_R, (my $dummy), 9;
1192		1414
1193	while (%SIG_EV) {	1415	while (%SIG_EV) {
1194	for (keys %SIG_EV) {	1416	for (keys %SIG_EV) {
1195	delete $SIG_EV{$_};	1417	delete $SIG_EV{$_};
1196	$_->() for values %{ $SIG_CB{$_} || {} };	1418	$_->() for values %{ $SIG_CB{$_} || {} };
1197	}	1419	}
1198	}	1420	}
1199	}	1421	}
1200		1422
		1423	# install a dummy wakeup watcher to reduce signal catching latency
		1424	sub _sig_add() {
		1425	unless ($SIG_COUNT++) {
		1426	# try to align timer on a full-second boundary, if possible
		1427	my $NOW = AE::now;
		1428
		1429	$SIG_TW = AE::timer
		1430	$MAX_SIGNAL_LATENCY - ($NOW - int $NOW),
		1431	$MAX_SIGNAL_LATENCY,
		1432	sub { } # just for the PERL_ASYNC_CHECK
		1433	;
		1434	}
		1435	}
		1436
		1437	sub _sig_del {
		1438	undef $SIG_TW
		1439	unless --$SIG_COUNT;
		1440	}
		1441
		1442	our $_sig_name_init; $_sig_name_init = sub {
		1443	eval q{ # poor man's autoloading
		1444	undef $_sig_name_init;
		1445
		1446	if (_have_async_interrupt) {
		1447	*sig2num = \&Async::Interrupt::sig2num;
		1448	*sig2name = \&Async::Interrupt::sig2name;
		1449	} else {
		1450	require Config;
		1451
		1452	my %signame2num;
		1453	@signame2num{ split ' ', $Config::Config{sig_name} }
		1454	= split ' ', $Config::Config{sig_num};
		1455
		1456	my @signum2name;
		1457	@signum2name[values %signame2num] = keys %signame2num;
		1458
		1459	*sig2num = sub($) {
		1460	$_[0] > 0 ? shift : $signame2num{+shift}
		1461	};
		1462	*sig2name = sub ($) {
		1463	$_[0] > 0 ? $signum2name[+shift] : shift
		1464	};
		1465	}
		1466	};
		1467	die if $@;
		1468	};
		1469
		1470	sub sig2num ($) { &$_sig_name_init; &sig2num }
		1471	sub sig2name($) { &$_sig_name_init; &sig2name }
		1472
1201	sub signal {	1473	sub signal {
1202	my (undef, %arg) = @_;	1474	eval q{ # poor man's autoloading {}
		1475	# probe for availability of Async::Interrupt
		1476	if (_have_async_interrupt) {
		1477	warn "AnyEvent: using Async::Interrupt for race-free signal handling.\n" if $VERBOSE >= 8;
1203		1478
1204	unless ($SIGPIPE_R) {	1479	$SIGPIPE_R = new Async::Interrupt::EventPipe;
1205	require Fcntl;	1480	$SIG_IO = AE::io $SIGPIPE_R->fileno, 0, \&_signal_exec;
1206		1481
1207	if (AnyEvent::WIN32) {
1208	require AnyEvent::Util;
1209
1210	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
1211	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R) if $SIGPIPE_R;
1212	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W) if $SIGPIPE_W; # just in case
1213	} else {	1482	} else {
		1483	warn "AnyEvent: using emulated perl signal handling with latency timer.\n" if $VERBOSE >= 8;
		1484
		1485	require Fcntl;
		1486
		1487	if (AnyEvent::WIN32) {
		1488	require AnyEvent::Util;
		1489
		1490	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
		1491	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R, 1) if $SIGPIPE_R;
		1492	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W, 1) if $SIGPIPE_W; # just in case
		1493	} else {
1214	pipe $SIGPIPE_R, $SIGPIPE_W;	1494	pipe $SIGPIPE_R, $SIGPIPE_W;
1215	fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R;	1495	fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R;
1216	fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case	1496	fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case
1217		1497
1218	# not strictly required, as $^F is normally 2, but let's make sure...	1498	# not strictly required, as $^F is normally 2, but let's make sure...
1219	fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;	1499	fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
1220	fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;	1500	fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
		1501	}
		1502
		1503	$SIGPIPE_R
		1504	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";
		1505
		1506	$SIG_IO = AE::io $SIGPIPE_R, 0, \&_signal_exec;
1221	}	1507	}
1222		1508
1223	$SIGPIPE_R	1509	*signal = sub {
1224	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";	1510	my (undef, %arg) = @_;
1225		1511
1226	$SIG_IO = AnyEvent->io (fh => $SIGPIPE_R, poll => "r", cb => \&_signal_exec);
1227	}
1228
1229	my $signal = uc $arg{signal}	1512	my $signal = uc $arg{signal}
1230	or Carp::croak "required option 'signal' is missing";	1513	or Carp::croak "required option 'signal' is missing";
1231		1514
		1515	if ($HAVE_ASYNC_INTERRUPT) {
		1516	# async::interrupt
		1517
		1518	$signal = sig2num $signal;
1232	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};	1519	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
		1520
		1521	$SIG_ASY{$signal} ||= new Async::Interrupt
		1522	cb => sub { undef $SIG_EV{$signal} },
		1523	signal => $signal,
		1524	pipe => [$SIGPIPE_R->filenos],
		1525	pipe_autodrain => 0,
		1526	;
		1527
		1528	} else {
		1529	# pure perl
		1530
		1531	# AE::Util has been loaded in signal
		1532	$signal = sig2name $signal;
		1533	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
		1534
1233	$SIG{$signal} ||= sub {	1535	$SIG{$signal} ||= sub {
1234	local $!;	1536	local $!;
1235	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;	1537	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;
1236	undef $SIG_EV{$signal};	1538	undef $SIG_EV{$signal};
		1539	};
		1540
		1541	# can't do signal processing without introducing races in pure perl,
		1542	# so limit the signal latency.
		1543	_sig_add;
		1544	}
		1545
		1546	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
		1547	};
		1548
		1549	*AnyEvent::Base::signal::DESTROY = sub {
		1550	my ($signal, $cb) = @{$_[0]};
		1551
		1552	_sig_del;
		1553
		1554	delete $SIG_CB{$signal}{$cb};
		1555
		1556	$HAVE_ASYNC_INTERRUPT
		1557	? delete $SIG_ASY{$signal}
		1558	: # delete doesn't work with older perls - they then
		1559	# print weird messages, or just unconditionally exit
		1560	# instead of getting the default action.
		1561	undef $SIG{$signal}
		1562	unless keys %{ $SIG_CB{$signal} };
		1563	};
1237	};	1564	};
1238		1565	die if $@;
1239	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"	1566	&signal
1240	}
1241
1242	sub AnyEvent::Base::signal::DESTROY {
1243	my ($signal, $cb) = @{$_[0]};
1244
1245	delete $SIG_CB{$signal}{$cb};
1246
1247	# delete doesn't work with older perls - they then
1248	# print weird messages, or just unconditionally exit
1249	# instead of getting the default action.
1250	undef $SIG{$signal} unless keys %{ $SIG_CB{$signal} };
1251	}	1567	}
1252		1568
1253	# default implementation for ->child	1569	# default implementation for ->child
1254		1570
1255	our %PID_CB;	1571	our %PID_CB;
1256	our $CHLD_W;	1572	our $CHLD_W;
1257	our $CHLD_DELAY_W;	1573	our $CHLD_DELAY_W;
1258	our $WNOHANG;	1574	our $WNOHANG;
1259		1575
		1576	sub _emit_childstatus($$) {
		1577	my (undef, $rpid, $rstatus) = @_;
		1578
		1579	$_->($rpid, $rstatus)
		1580	for values %{ $PID_CB{$rpid} || {} },
		1581	values %{ $PID_CB{0} || {} };
		1582	}
		1583
1260	sub _sigchld {	1584	sub _sigchld {
		1585	my $pid;
		1586
		1587	AnyEvent->_emit_childstatus ($pid, $?)
1261	while (0 < (my $pid = waitpid -1, $WNOHANG)) {	1588	while ($pid = waitpid -1, $WNOHANG) > 0;
1262	$_->($pid, $?) for (values %{ $PID_CB{$pid} || {} }),
1263	(values %{ $PID_CB{0} || {} });
1264	}
1265	}	1589	}
1266		1590
1267	sub child {	1591	sub child {
1268	my (undef, %arg) = @_;	1592	my (undef, %arg) = @_;
1269		1593
1270	defined (my $pid = $arg{pid} + 0)	1594	defined (my $pid = $arg{pid} + 0)
1271	or Carp::croak "required option 'pid' is missing";	1595	or Carp::croak "required option 'pid' is missing";
1272		1596
1273	$PID_CB{$pid}{$arg{cb}} = $arg{cb};	1597	$PID_CB{$pid}{$arg{cb}} = $arg{cb};
1274		1598
		1599	# WNOHANG is almost cetrainly 1 everywhere
		1600	$WNOHANG ||= $^O =~ /^(?:openbsd|netbsd|linux|freebsd|cygwin|MSWin32)$/
		1601	? 1
1275	$WNOHANG ||= eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1;	1602	: eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1;
1276		1603
1277	unless ($CHLD_W) {	1604	unless ($CHLD_W) {
1278	$CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld);	1605	$CHLD_W = AE::signal CHLD => \&_sigchld;
1279	# child could be a zombie already, so make at least one round	1606	# child could be a zombie already, so make at least one round
1280	&_sigchld;	1607	&_sigchld;
1281	}	1608	}
1282		1609
1283	bless [$pid, $arg{cb}], "AnyEvent::Base::child"	1610	bless [$pid, $arg{cb}], "AnyEvent::Base::child"
…		…
1309	# never use more then 50% of the time for the idle watcher,	1636	# never use more then 50% of the time for the idle watcher,
1310	# within some limits	1637	# within some limits
1311	$w = 0.0001 if $w < 0.0001;	1638	$w = 0.0001 if $w < 0.0001;
1312	$w = 5 if $w > 5;	1639	$w = 5 if $w > 5;
1313		1640
1314	$w = AnyEvent->timer (after => $w, cb => $rcb);	1641	$w = AE::timer $w, 0, $rcb;
1315	} else {	1642	} else {
1316	# clean up...	1643	# clean up...
1317	undef $w;	1644	undef $w;
1318	undef $rcb;	1645	undef $rcb;
1319	}	1646	}
1320	};	1647	};
1321		1648
1322	$w = AnyEvent->timer (after => 0.05, cb => $rcb);	1649	$w = AE::timer 0.05, 0, $rcb;
1323		1650
1324	bless \\$cb, "AnyEvent::Base::idle"	1651	bless \\$cb, "AnyEvent::Base::idle"
1325	}	1652	}
1326		1653
1327	sub AnyEvent::Base::idle::DESTROY {	1654	sub AnyEvent::Base::idle::DESTROY {
…		…
1332		1659
1333	our @ISA = AnyEvent::CondVar::Base::;	1660	our @ISA = AnyEvent::CondVar::Base::;
1334		1661
1335	package AnyEvent::CondVar::Base;	1662	package AnyEvent::CondVar::Base;
1336		1663
1337	use overload	1664	#use overload
1338	'&{}' => sub { my $self = shift; sub { $self->send (@_) } },	1665	# '&{}' => sub { my $self = shift; sub { $self->send (@_) } },
1339	fallback => 1;	1666	# fallback => 1;
		1667
		1668	# save 300+ kilobytes by dirtily hardcoding overloading
		1669	${"AnyEvent::CondVar::Base::OVERLOAD"}{dummy}++; # Register with magic by touching.
		1670	*{'AnyEvent::CondVar::Base::()'} = sub { }; # "Make it findable via fetchmethod."
		1671	*{'AnyEvent::CondVar::Base::(&{}'} = sub { my $self = shift; sub { $self->send (@_) } }; # &{}
		1672	${'AnyEvent::CondVar::Base::()'} = 1; # fallback
		1673
		1674	our $WAITING;
1340		1675
1341	sub _send {	1676	sub _send {
1342	# nop	1677	# nop
1343	}	1678	}
1344		1679
…		…
1357	sub ready {	1692	sub ready {
1358	$_[0]{_ae_sent}	1693	$_[0]{_ae_sent}
1359	}	1694	}
1360		1695
1361	sub _wait {	1696	sub _wait {
		1697	$WAITING
		1698	and !$_[0]{_ae_sent}
		1699	and Carp::croak "AnyEvent::CondVar: recursive blocking wait detected";
		1700
		1701	local $WAITING = 1;
1362	AnyEvent->one_event while !$_[0]{_ae_sent};	1702	AnyEvent->one_event while !$_[0]{_ae_sent};
1363	}	1703	}
1364		1704
1365	sub recv {	1705	sub recv {
1366	$_[0]->_wait;	1706	$_[0]->_wait;
…		…
1368	Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak};	1708	Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak};
1369	wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0]	1709	wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0]
1370	}	1710	}
1371		1711
1372	sub cb {	1712	sub cb {
1373	$_[0]{_ae_cb} = $_[1] if @_ > 1;	1713	my $cv = shift;
		1714
		1715	@_
		1716	and $cv->{_ae_cb} = shift
		1717	and $cv->{_ae_sent}
		1718	and (delete $cv->{_ae_cb})->($cv);
		1719
1374	$_[0]{_ae_cb}	1720	$cv->{_ae_cb}
1375	}	1721	}
1376		1722
1377	sub begin {	1723	sub begin {
1378	++$_[0]{_ae_counter};	1724	++$_[0]{_ae_counter};
1379	$_[0]{_ae_end_cb} = $_[1] if @_ > 1;	1725	$_[0]{_ae_end_cb} = $_[1] if @_ > 1;
…		…
1428	C<PERL_ANYEVENT_MODEL>.	1774	C<PERL_ANYEVENT_MODEL>.
1429		1775
1430	When set to C<2> or higher, cause AnyEvent to report to STDERR which event	1776	When set to C<2> or higher, cause AnyEvent to report to STDERR which event
1431	model it chooses.	1777	model it chooses.
1432		1778
		1779	When set to C<8> or higher, then AnyEvent will report extra information on
		1780	which optional modules it loads and how it implements certain features.
		1781
1433	=item C<PERL_ANYEVENT_STRICT>	1782	=item C<PERL_ANYEVENT_STRICT>
1434		1783
1435	AnyEvent does not do much argument checking by default, as thorough	1784	AnyEvent does not do much argument checking by default, as thorough
1436	argument checking is very costly. Setting this variable to a true value	1785	argument checking is very costly. Setting this variable to a true value
1437	will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly	1786	will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly
1438	check the arguments passed to most method calls. If it finds any problems,	1787	check the arguments passed to most method calls. If it finds any problems,
1439	it will croak.	1788	it will croak.
1440		1789
1441	In other words, enables "strict" mode.	1790	In other words, enables "strict" mode.
1442		1791
1443	Unlike C<use strict>, it is definitely recommended to keep it off in	1792	Unlike C<use strict> (or it's modern cousin, C<< use L<common::sense>
1444	production. Keeping C<PERL_ANYEVENT_STRICT=1> in your environment while	1793	>>, it is definitely recommended to keep it off in production. Keeping
1445	developing programs can be very useful, however.	1794	C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs
		1795	can be very useful, however.
1446		1796
1447	=item C<PERL_ANYEVENT_MODEL>	1797	=item C<PERL_ANYEVENT_MODEL>
1448		1798
1449	This can be used to specify the event model to be used by AnyEvent, before	1799	This can be used to specify the event model to be used by AnyEvent, before
1450	auto detection and -probing kicks in. It must be a string consisting	1800	auto detection and -probing kicks in. It must be a string consisting
…		…
1512		1862
1513	When neither C<ca_file> nor C<ca_path> was specified during	1863	When neither C<ca_file> nor C<ca_path> was specified during
1514	L<AnyEvent::TLS> context creation, and either of these environment	1864	L<AnyEvent::TLS> context creation, and either of these environment
1515	variables exist, they will be used to specify CA certificate locations	1865	variables exist, they will be used to specify CA certificate locations
1516	instead of a system-dependent default.	1866	instead of a system-dependent default.
		1867
		1868	=item C<PERL_ANYEVENT_AVOID_GUARD> and C<PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT>
		1869
		1870	When these are set to C<1>, then the respective modules are not
		1871	loaded. Mostly good for testing AnyEvent itself.
1517		1872
1518	=back	1873	=back
1519		1874
1520	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE	1875	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE
1521		1876
…		…
1579	warn "read: $input\n"; # output what has been read	1934	warn "read: $input\n"; # output what has been read
1580	$cv->send if $input =~ /^q/i; # quit program if /^q/i	1935	$cv->send if $input =~ /^q/i; # quit program if /^q/i
1581	},	1936	},
1582	);	1937	);
1583		1938
1584	my $time_watcher; # can only be used once
1585
1586	sub new_timer {
1587	$timer = AnyEvent->timer (after => 1, cb => sub {	1939	my $time_watcher = AnyEvent->timer (after => 1, interval => 1, cb => sub {
1588	warn "timeout\n"; # print 'timeout' about every second	1940	warn "timeout\n"; # print 'timeout' at most every second
1589	&new_timer; # and restart the time
1590	});	1941	});
1591	}
1592
1593	new_timer; # create first timer
1594		1942
1595	$cv->recv; # wait until user enters /^q/i	1943	$cv->recv; # wait until user enters /^q/i
1596		1944
1597	=head1 REAL-WORLD EXAMPLE	1945	=head1 REAL-WORLD EXAMPLE
1598		1946
…		…
1729	through AnyEvent. The benchmark creates a lot of timers (with a zero	2077	through AnyEvent. The benchmark creates a lot of timers (with a zero
1730	timeout) and I/O watchers (watching STDOUT, a pty, to become writable,	2078	timeout) and I/O watchers (watching STDOUT, a pty, to become writable,
1731	which it is), lets them fire exactly once and destroys them again.	2079	which it is), lets them fire exactly once and destroys them again.
1732		2080
1733	Source code for this benchmark is found as F<eg/bench> in the AnyEvent	2081	Source code for this benchmark is found as F<eg/bench> in the AnyEvent
1734	distribution.	2082	distribution. It uses the L<AE> interface, which makes a real difference
		2083	for the EV and Perl backends only.
1735		2084
1736	=head3 Explanation of the columns	2085	=head3 Explanation of the columns
1737		2086
1738	I<watcher> is the number of event watchers created/destroyed. Since	2087	I<watcher> is the number of event watchers created/destroyed. Since
1739	different event models feature vastly different performances, each event	2088	different event models feature vastly different performances, each event
…		…
1760	watcher.	2109	watcher.
1761		2110
1762	=head3 Results	2111	=head3 Results
1763		2112
1764	name watchers bytes create invoke destroy comment	2113	name watchers bytes create invoke destroy comment
1765	EV/EV 400000 224 0.47 0.35 0.27 EV native interface	2114	EV/EV 100000 223 0.47 0.43 0.27 EV native interface
1766	EV/Any 100000 224 2.88 0.34 0.27 EV + AnyEvent watchers	2115	EV/Any 100000 223 0.48 0.42 0.26 EV + AnyEvent watchers
1767	CoroEV/Any 100000 224 2.85 0.35 0.28 coroutines + Coro::Signal	2116	Coro::EV/Any 100000 223 0.47 0.42 0.26 coroutines + Coro::Signal
1768	Perl/Any 100000 452 4.13 0.73 0.95 pure perl implementation	2117	Perl/Any 100000 431 2.70 0.74 0.92 pure perl implementation
1769	Event/Event 16000 517 32.20 31.80 0.81 Event native interface	2118	Event/Event 16000 516 31.16 31.84 0.82 Event native interface
1770	Event/Any 16000 590 35.85 31.55 1.06 Event + AnyEvent watchers	2119	Event/Any 16000 1203 42.61 34.79 1.80 Event + AnyEvent watchers
1771	IOAsync/Any 16000 989 38.10 32.77 11.13 via IO::Async::Loop::IO_Poll	2120	IOAsync/Any 16000 1911 41.92 27.45 16.81 via IO::Async::Loop::IO_Poll
1772	IOAsync/Any 16000 990 37.59 29.50 10.61 via IO::Async::Loop::Epoll	2121	IOAsync/Any 16000 1726 40.69 26.37 15.25 via IO::Async::Loop::Epoll
1773	Glib/Any 16000 1357 102.33 12.31 51.00 quadratic behaviour	2122	Glib/Any 16000 1118 89.00 12.57 51.17 quadratic behaviour
1774	Tk/Any 2000 1860 27.20 66.31 14.00 SEGV with >> 2000 watchers	2123	Tk/Any 2000 1346 20.96 10.75 8.00 SEGV with >> 2000 watchers
1775	POE/Event 2000 6328 109.99 751.67 14.02 via POE::Loop::Event	2124	POE/Any 2000 6951 108.97 795.32 14.24 via POE::Loop::Event
1776	POE/Select 2000 6027 94.54 809.13 579.80 via POE::Loop::Select	2125	POE/Any 2000 6648 94.79 774.40 575.51 via POE::Loop::Select
1777		2126
1778	=head3 Discussion	2127	=head3 Discussion
1779		2128
1780	The benchmark does I<not> measure scalability of the event loop very	2129	The benchmark does I<not> measure scalability of the event loop very
1781	well. For example, a select-based event loop (such as the pure perl one)	2130	well. For example, a select-based event loop (such as the pure perl one)
…		…
1793	benchmark machine, handling an event takes roughly 1600 CPU cycles with	2142	benchmark machine, handling an event takes roughly 1600 CPU cycles with
1794	EV, 3100 CPU cycles with AnyEvent's pure perl loop and almost 3000000 CPU	2143	EV, 3100 CPU cycles with AnyEvent's pure perl loop and almost 3000000 CPU
1795	cycles with POE.	2144	cycles with POE.
1796		2145
1797	C<EV> is the sole leader regarding speed and memory use, which are both	2146	C<EV> is the sole leader regarding speed and memory use, which are both
1798	maximal/minimal, respectively. Even when going through AnyEvent, it uses	2147	maximal/minimal, respectively. When using the L<AE> API there is zero
		2148	overhead (when going through the AnyEvent API create is about 5-6 times
		2149	slower, with other times being equal, so still uses far less memory than
1799	far less memory than any other event loop and is still faster than Event	2150	any other event loop and is still faster than Event natively).
1800	natively.
1801		2151
1802	The pure perl implementation is hit in a few sweet spots (both the	2152	The pure perl implementation is hit in a few sweet spots (both the
1803	constant timeout and the use of a single fd hit optimisations in the perl	2153	constant timeout and the use of a single fd hit optimisations in the perl
1804	interpreter and the backend itself). Nevertheless this shows that it	2154	interpreter and the backend itself). Nevertheless this shows that it
1805	adds very little overhead in itself. Like any select-based backend its	2155	adds very little overhead in itself. Like any select-based backend its
…		…
1879	In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100	2229	In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100
1880	(1%) are active. This mirrors the activity of large servers with many	2230	(1%) are active. This mirrors the activity of large servers with many
1881	connections, most of which are idle at any one point in time.	2231	connections, most of which are idle at any one point in time.
1882		2232
1883	Source code for this benchmark is found as F<eg/bench2> in the AnyEvent	2233	Source code for this benchmark is found as F<eg/bench2> in the AnyEvent
1884	distribution.	2234	distribution. It uses the L<AE> interface, which makes a real difference
		2235	for the EV and Perl backends only.
1885		2236
1886	=head3 Explanation of the columns	2237	=head3 Explanation of the columns
1887		2238
1888	I<sockets> is the number of sockets, and twice the number of "servers" (as	2239	I<sockets> is the number of sockets, and twice the number of "servers" (as
1889	each server has a read and write socket end).	2240	each server has a read and write socket end).
…		…
1897	a new one that moves the timeout into the future.	2248	a new one that moves the timeout into the future.
1898		2249
1899	=head3 Results	2250	=head3 Results
1900		2251
1901	name sockets create request	2252	name sockets create request
1902	EV 20000 69.01 11.16	2253	EV 20000 62.66 7.99
1903	Perl 20000 73.32 35.87	2254	Perl 20000 68.32 32.64
1904	IOAsync 20000 157.00 98.14 epoll	2255	IOAsync 20000 174.06 101.15 epoll
1905	IOAsync 20000 159.31 616.06 poll	2256	IOAsync 20000 174.67 610.84 poll
1906	Event 20000 212.62 257.32	2257	Event 20000 202.69 242.91
1907	Glib 20000 651.16 1896.30	2258	Glib 20000 557.01 1689.52
1908	POE 20000 349.67 12317.24 uses POE::Loop::Event	2259	POE 20000 341.54 12086.32 uses POE::Loop::Event
1909		2260
1910	=head3 Discussion	2261	=head3 Discussion
1911		2262
1912	This benchmark I<does> measure scalability and overall performance of the	2263	This benchmark I<does> measure scalability and overall performance of the
1913	particular event loop.	2264	particular event loop.
…		…
2039	As you can see, the AnyEvent + EV combination even beats the	2390	As you can see, the AnyEvent + EV combination even beats the
2040	hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl	2391	hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl
2041	backend easily beats IO::Lambda and POE.	2392	backend easily beats IO::Lambda and POE.
2042		2393
2043	And even the 100% non-blocking version written using the high-level (and	2394	And even the 100% non-blocking version written using the high-level (and
2044	slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda by a	2395	slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda
2045	large margin, even though it does all of DNS, tcp-connect and socket I/O	2396	higher level ("unoptimised") abstractions by a large margin, even though
2046	in a non-blocking way.	2397	it does all of DNS, tcp-connect and socket I/O in a non-blocking way.
2047		2398
2048	The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and	2399	The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and
2049	F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are	2400	F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are
2050	part of the IO::lambda distribution and were used without any changes.	2401	part of the IO::Lambda distribution and were used without any changes.
2051		2402
2052		2403
2053	=head1 SIGNALS	2404	=head1 SIGNALS
2054		2405
2055	AnyEvent currently installs handlers for these signals:	2406	AnyEvent currently installs handlers for these signals:
…		…
2060		2411
2061	A handler for C<SIGCHLD> is installed by AnyEvent's child watcher	2412	A handler for C<SIGCHLD> is installed by AnyEvent's child watcher
2062	emulation for event loops that do not support them natively. Also, some	2413	emulation for event loops that do not support them natively. Also, some
2063	event loops install a similar handler.	2414	event loops install a similar handler.
2064		2415
2065	If, when AnyEvent is loaded, SIGCHLD is set to IGNORE, then AnyEvent will	2416	Additionally, when AnyEvent is loaded and SIGCHLD is set to IGNORE, then
2066	reset it to default, to avoid losing child exit statuses.	2417	AnyEvent will reset it to default, to avoid losing child exit statuses.
2067		2418
2068	=item SIGPIPE	2419	=item SIGPIPE
2069		2420
2070	A no-op handler is installed for C<SIGPIPE> when C<$SIG{PIPE}> is C<undef>	2421	A no-op handler is installed for C<SIGPIPE> when C<$SIG{PIPE}> is C<undef>
2071	when AnyEvent gets loaded.	2422	when AnyEvent gets loaded.
…		…
2089	if $SIG{CHLD} eq 'IGNORE';	2440	if $SIG{CHLD} eq 'IGNORE';
2090		2441
2091	$SIG{PIPE} = sub { }	2442	$SIG{PIPE} = sub { }
2092	unless defined $SIG{PIPE};	2443	unless defined $SIG{PIPE};
2093		2444
		2445	=head1 RECOMMENDED/OPTIONAL MODULES
		2446
		2447	One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and
		2448	it's built-in modules) are required to use it.
		2449
		2450	That does not mean that AnyEvent won't take advantage of some additional
		2451	modules if they are installed.
		2452
		2453	This section epxlains which additional modules will be used, and how they
		2454	affect AnyEvent's operetion.
		2455
		2456	=over 4
		2457
		2458	=item L<Async::Interrupt>
		2459
		2460	This slightly arcane module is used to implement fast signal handling: To
		2461	my knowledge, there is no way to do completely race-free and quick
		2462	signal handling in pure perl. To ensure that signals still get
		2463	delivered, AnyEvent will start an interval timer to wake up perl (and
		2464	catch the signals) with some delay (default is 10 seconds, look for
		2465	C<$AnyEvent::MAX_SIGNAL_LATENCY>).
		2466
		2467	If this module is available, then it will be used to implement signal
		2468	catching, which means that signals will not be delayed, and the event loop
		2469	will not be interrupted regularly, which is more efficient (And good for
		2470	battery life on laptops).
		2471
		2472	This affects not just the pure-perl event loop, but also other event loops
		2473	that have no signal handling on their own (e.g. Glib, Tk, Qt).
		2474
		2475	Some event loops (POE, Event, Event::Lib) offer signal watchers natively,
		2476	and either employ their own workarounds (POE) or use AnyEvent's workaround
		2477	(using C<$AnyEvent::MAX_SIGNAL_LATENCY>). Installing L<Async::Interrupt>
		2478	does nothing for those backends.
		2479
		2480	=item L<EV>
		2481
		2482	This module isn't really "optional", as it is simply one of the backend
		2483	event loops that AnyEvent can use. However, it is simply the best event
		2484	loop available in terms of features, speed and stability: It supports
		2485	the AnyEvent API optimally, implements all the watcher types in XS, does
		2486	automatic timer adjustments even when no monotonic clock is available,
		2487	can take avdantage of advanced kernel interfaces such as C<epoll> and
		2488	C<kqueue>, and is the fastest backend I<by far>. You can even embed
		2489	L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>).
		2490
		2491	=item L<Guard>
		2492
		2493	The guard module, when used, will be used to implement
		2494	C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a
		2495	lot less memory), but otherwise doesn't affect guard operation much. It is
		2496	purely used for performance.
		2497
		2498	=item L<JSON> and L<JSON::XS>
		2499
		2500	One of these modules is required when you want to read or write JSON data
		2501	via L<AnyEvent::Handle>. It is also written in pure-perl, but can take
		2502	advantage of the ultra-high-speed L<JSON::XS> module when it is installed.
		2503
		2504	In fact, L<AnyEvent::Handle> will use L<JSON::XS> by default if it is
		2505	installed.
		2506
		2507	=item L<Net::SSLeay>
		2508
		2509	Implementing TLS/SSL in Perl is certainly interesting, but not very
		2510	worthwhile: If this module is installed, then L<AnyEvent::Handle> (with
		2511	the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL.
		2512
		2513	=item L<Time::HiRes>
		2514
		2515	This module is part of perl since release 5.008. It will be used when the
		2516	chosen event library does not come with a timing source on it's own. The
		2517	pure-perl event loop (L<AnyEvent::Impl::Perl>) will additionally use it to
		2518	try to use a monotonic clock for timing stability.
		2519
		2520	=back
		2521
		2522
2094	=head1 FORK	2523	=head1 FORK
2095		2524
2096	Most event libraries are not fork-safe. The ones who are usually are	2525	Most event libraries are not fork-safe. The ones who are usually are
2097	because they rely on inefficient but fork-safe C<select> or C<poll>	2526	because they rely on inefficient but fork-safe C<select> or C<poll>
2098	calls. Only L<EV> is fully fork-aware.	2527	calls. Only L<EV> is fully fork-aware.
2099		2528
2100	If you have to fork, you must either do so I<before> creating your first	2529	If you have to fork, you must either do so I<before> creating your first
2101	watcher OR you must not use AnyEvent at all in the child.	2530	watcher OR you must not use AnyEvent at all in the child OR you must do
		2531	something completely out of the scope of AnyEvent.
2102		2532
2103		2533
2104	=head1 SECURITY CONSIDERATIONS	2534	=head1 SECURITY CONSIDERATIONS
2105		2535
2106	AnyEvent can be forced to load any event model via	2536	AnyEvent can be forced to load any event model via
…		…
2144	L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.	2574	L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.
2145		2575
2146	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,	2576	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,
2147	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,	2577	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,
2148	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,	2578	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,
2149	L<AnyEvent::Impl::POE>.	2579	L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>, L<Anyevent::Impl::Irssi>.
2150		2580
2151	Non-blocking file handles, sockets, TCP clients and	2581	Non-blocking file handles, sockets, TCP clients and
2152	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>.	2582	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.
2153		2583
2154	Asynchronous DNS: L<AnyEvent::DNS>.	2584	Asynchronous DNS: L<AnyEvent::DNS>.
2155		2585
2156	Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>,	2586	Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>,
		2587	L<Coro::Event>,
2157		2588
2158	Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>, L<AnyEvent::DNS>.	2589	Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::XMPP>,
		2590	L<AnyEvent::HTTP>.
2159		2591
2160		2592
2161	=head1 AUTHOR	2593	=head1 AUTHOR
2162		2594
2163	Marc Lehmann <schmorp@schmorp.de>	2595	Marc Lehmann <schmorp@schmorp.de>

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