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Revision 1.296 by root, Tue Nov 17 01:19:49 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, POE - various supported event loops	5	EV, Event, Glib, Tk, Perl, Event::Lib, Irssi, rxvt-unicode, IO::Async, Qt
		6	and POE are various supported event loops/environments.
6		7
7	=head1 SYNOPSIS	8	=head1 SYNOPSIS
8		9
9	use AnyEvent;	10	use AnyEvent;
10		11
…		…
39	=head1 INTRODUCTION/TUTORIAL	40	=head1 INTRODUCTION/TUTORIAL
40		41
41	This manpage is mainly a reference manual. If you are interested	42	This manpage is mainly a reference manual. If you are interested
42	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
43	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.
44		53
45	=head1 WHY YOU SHOULD USE THIS MODULE (OR NOT)	54	=head1 WHY YOU SHOULD USE THIS MODULE (OR NOT)
46		55
47	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
48	nowadays. So what is different about AnyEvent?	57	nowadays. So what is different about AnyEvent?
…		…
172	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
173	declared.	182	declared.
174		183
175	=head2 I/O WATCHERS	184	=head2 I/O WATCHERS
176		185
		186	$w = AnyEvent->io (
		187	fh => <filehandle_or_fileno>,
		188	poll => <"r" or "w">,
		189	cb => <callback>,
		190	);
		191
177	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
178	with the following mandatory key-value pairs as arguments:	193	with the following mandatory key-value pairs as arguments:
179		194
180	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
181	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
182	handle). Note that only file handles pointing to things for which	197	handle). Note that only file handles pointing to things for which
183	non-blocking operation makes sense are allowed. This includes sockets,	198	non-blocking operation makes sense are allowed. This includes sockets,
184	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
185	or block devices.	200	or block devices.
…		…
210	undef $w;	225	undef $w;
211	});	226	});
212		227
213	=head2 TIME WATCHERS	228	=head2 TIME WATCHERS
214		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
215	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 >>
216	method with the following mandatory arguments:	239	method with the following mandatory arguments:
217		240
218	C<after> specifies after how many seconds (fractional values are	241	C<after> specifies after how many seconds (fractional values are
219	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
…		…
340	might affect timers and time-outs.	363	might affect timers and time-outs.
341		364
342	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
343	event loop's idea of "current time".	366	event loop's idea of "current time".
344		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
345	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.
346		376
347	=back	377	=back
348		378
349	=head2 SIGNAL WATCHERS	379	=head2 SIGNAL WATCHERS
		380
		381	$w = AnyEvent->signal (signal => <uppercase_signal_name>, cb => <callback>);
350		382
351	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
352	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
353	callback to be invoked whenever a signal occurs.	385	callback to be invoked whenever a signal occurs.
354		386
…		…
360	invocation, and callback invocation will be synchronous. Synchronous means	392	invocation, and callback invocation will be synchronous. Synchronous means
361	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,
362	but it is guaranteed not to interrupt any other callbacks.	394	but it is guaranteed not to interrupt any other callbacks.
363		395
364	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
365	between multiple watchers.	397	between multiple watchers, and AnyEvent will ensure that signals will not
		398	interrupt your program at bad times.
366		399
367	This watcher might use C<%SIG>, so programs overwriting those signals	400	This watcher might use C<%SIG> (depending on the event loop used),
368	directly will likely not work correctly.	401	so programs overwriting those signals directly will likely not work
		402	correctly.
369		403
370	Example: exit on SIGINT	404	Example: exit on SIGINT
371		405
372	my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });	406	my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });
373		407
		408	=head3 Signal Races, Delays and Workarounds
		409
		410	Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support attaching
		411	callbacks to signals in a generic way, which is a pity, as you cannot
		412	do race-free signal handling in perl, requiring C libraries for
		413	this. AnyEvent will try to do it's best, which means in some cases,
		414	signals will be delayed. The maximum time a signal might be delayed is
		415	specified in C<$AnyEvent::MAX_SIGNAL_LATENCY> (default: 10 seconds). This
		416	variable can be changed only before the first signal watcher is created,
		417	and should be left alone otherwise. This variable determines how often
		418	AnyEvent polls for signals (in case a wake-up was missed). Higher values
		419	will cause fewer spurious wake-ups, which is better for power and CPU
		420	saving.
		421
		422	All these problems can be avoided by installing the optional
		423	L<Async::Interrupt> module, which works with most event loops. It will not
		424	work with inherently broken event loops such as L<Event> or L<Event::Lib>
		425	(and not with L<POE> currently, as POE does it's own workaround with
		426	one-second latency). For those, you just have to suffer the delays.
		427
374	=head2 CHILD PROCESS WATCHERS	428	=head2 CHILD PROCESS WATCHERS
375		429
		430	$w = AnyEvent->child (pid => <process id>, cb => <callback>);
		431
376	You can also watch on a child process exit and catch its exit status.	432	You can also watch on a child process exit and catch its exit status.
377		433
378	The child process is specified by the C<pid> argument (if set to C<0>, it	434	The child process is specified by the C<pid> argument (one some backends,
379	watches for any child process exit). The watcher will triggered only when	435	using C<0> watches for any child process exit, on others this will
380	the child process has finished and an exit status is available, not on	436	croak). The watcher will be triggered only when the child process has
381	any trace events (stopped/continued).	437	finished and an exit status is available, not on any trace events
		438	(stopped/continued).
382		439
383	The callback will be called with the pid and exit status (as returned by	440	The callback will be called with the pid and exit status (as returned by
384	waitpid), so unlike other watcher types, you I<can> rely on child watcher	441	waitpid), so unlike other watcher types, you I<can> rely on child watcher
385	callback arguments.	442	callback arguments.
386		443
…		…
391		448
392	There is a slight catch to child watchers, however: you usually start them	449	There is a slight catch to child watchers, however: you usually start them
393	I<after> the child process was created, and this means the process could	450	I<after> the child process was created, and this means the process could
394	have exited already (and no SIGCHLD will be sent anymore).	451	have exited already (and no SIGCHLD will be sent anymore).
395		452
396	Not all event models handle this correctly (POE doesn't), but even for	453	Not all event models handle this correctly (neither POE nor IO::Async do,
		454	see their AnyEvent::Impl manpages for details), but even for event models
397	event models that I<do> handle this correctly, they usually need to be	455	that I<do> handle this correctly, they usually need to be loaded before
398	loaded before the process exits (i.e. before you fork in the first place).	456	the process exits (i.e. before you fork in the first place). AnyEvent's
		457	pure perl event loop handles all cases correctly regardless of when you
		458	start the watcher.
399		459
400	This means you cannot create a child watcher as the very first thing in an	460	This means you cannot create a child watcher as the very first
401	AnyEvent program, you I<have> to create at least one watcher before you	461	thing in an AnyEvent program, you I<have> to create at least one
402	C<fork> the child (alternatively, you can call C<AnyEvent::detect>).	462	watcher before you C<fork> the child (alternatively, you can call
		463	C<AnyEvent::detect>).
		464
		465	As most event loops do not support waiting for child events, they will be
		466	emulated by AnyEvent in most cases, in which the latency and race problems
		467	mentioned in the description of signal watchers apply.
403		468
404	Example: fork a process and wait for it	469	Example: fork a process and wait for it
405		470
406	my $done = AnyEvent->condvar;	471	my $done = AnyEvent->condvar;
407		472
…		…
419	# do something else, then wait for process exit	484	# do something else, then wait for process exit
420	$done->recv;	485	$done->recv;
421		486
422	=head2 IDLE WATCHERS	487	=head2 IDLE WATCHERS
423		488
		489	$w = AnyEvent->idle (cb => <callback>);
		490
424	Sometimes there is a need to do something, but it is not so important	491	Sometimes there is a need to do something, but it is not so important
425	to do it instantly, but only when there is nothing better to do. This	492	to do it instantly, but only when there is nothing better to do. This
426	"nothing better to do" is usually defined to be "no other events need	493	"nothing better to do" is usually defined to be "no other events need
427	attention by the event loop".	494	attention by the event loop".
428		495
…		…
454	});	521	});
455	});	522	});
456		523
457	=head2 CONDITION VARIABLES	524	=head2 CONDITION VARIABLES
458		525
		526	$cv = AnyEvent->condvar;
		527
		528	$cv->send (<list>);
		529	my @res = $cv->recv;
		530
459	If you are familiar with some event loops you will know that all of them	531	If you are familiar with some event loops you will know that all of them
460	require you to run some blocking "loop", "run" or similar function that	532	require you to run some blocking "loop", "run" or similar function that
461	will actively watch for new events and call your callbacks.	533	will actively watch for new events and call your callbacks.
462		534
463	AnyEvent is different, it expects somebody else to run the event loop and	535	AnyEvent is slightly different: it expects somebody else to run the event
464	will only block when necessary (usually when told by the user).	536	loop and will only block when necessary (usually when told by the user).
465		537
466	The instrument to do that is called a "condition variable", so called	538	The instrument to do that is called a "condition variable", so called
467	because they represent a condition that must become true.	539	because they represent a condition that must become true.
468		540
		541	Now is probably a good time to look at the examples further below.
		542
469	Condition variables can be created by calling the C<< AnyEvent->condvar	543	Condition variables can be created by calling the C<< AnyEvent->condvar
470	>> method, usually without arguments. The only argument pair allowed is	544	>> method, usually without arguments. The only argument pair allowed is
471
472	C<cb>, which specifies a callback to be called when the condition variable	545	C<cb>, which specifies a callback to be called when the condition variable
473	becomes true, with the condition variable as the first argument (but not	546	becomes true, with the condition variable as the first argument (but not
474	the results).	547	the results).
475		548
476	After creation, the condition variable is "false" until it becomes "true"	549	After creation, the condition variable is "false" until it becomes "true"
…		…
481	Condition variables are similar to callbacks, except that you can	554	Condition variables are similar to callbacks, except that you can
482	optionally wait for them. They can also be called merge points - points	555	optionally wait for them. They can also be called merge points - points
483	in time where multiple outstanding events have been processed. And yet	556	in time where multiple outstanding events have been processed. And yet
484	another way to call them is transactions - each condition variable can be	557	another way to call them is transactions - each condition variable can be
485	used to represent a transaction, which finishes at some point and delivers	558	used to represent a transaction, which finishes at some point and delivers
486	a result.	559	a result. And yet some people know them as "futures" - a promise to
		560	compute/deliver something that you can wait for.
487		561
488	Condition variables are very useful to signal that something has finished,	562	Condition variables are very useful to signal that something has finished,
489	for example, if you write a module that does asynchronous http requests,	563	for example, if you write a module that does asynchronous http requests,
490	then a condition variable would be the ideal candidate to signal the	564	then a condition variable would be the ideal candidate to signal the
491	availability of results. The user can either act when the callback is	565	availability of results. The user can either act when the callback is
…		…
525	after => 1,	599	after => 1,
526	cb => sub { $result_ready->send },	600	cb => sub { $result_ready->send },
527	);	601	);
528		602
529	# this "blocks" (while handling events) till the callback	603	# this "blocks" (while handling events) till the callback
530	# calls send	604	# calls ->send
531	$result_ready->recv;	605	$result_ready->recv;
532		606
533	Example: wait for a timer, but take advantage of the fact that	607	Example: wait for a timer, but take advantage of the fact that condition
534	condition variables are also code references.	608	variables are also callable directly.
535		609
536	my $done = AnyEvent->condvar;	610	my $done = AnyEvent->condvar;
537	my $delay = AnyEvent->timer (after => 5, cb => $done);	611	my $delay = AnyEvent->timer (after => 5, cb => $done);
538	$done->recv;	612	$done->recv;
539		613
…		…
545		619
546	...	620	...
547		621
548	my @info = $couchdb->info->recv;	622	my @info = $couchdb->info->recv;
549		623
550	And this is how you would just ste a callback to be called whenever the	624	And this is how you would just set a callback to be called whenever the
551	results are available:	625	results are available:
552		626
553	$couchdb->info->cb (sub {	627	$couchdb->info->cb (sub {
554	my @info = $_[0]->recv;	628	my @info = $_[0]->recv;
555	});	629	});
…		…
573	immediately from within send.	647	immediately from within send.
574		648
575	Any arguments passed to the C<send> call will be returned by all	649	Any arguments passed to the C<send> call will be returned by all
576	future C<< ->recv >> calls.	650	future C<< ->recv >> calls.
577		651
578	Condition variables are overloaded so one can call them directly	652	Condition variables are overloaded so one can call them directly (as if
579	(as a code reference). Calling them directly is the same as calling	653	they were a code reference). Calling them directly is the same as calling
580	C<send>. Note, however, that many C-based event loops do not handle	654	C<send>.
581	overloading, so as tempting as it may be, passing a condition variable
582	instead of a callback does not work. Both the pure perl and EV loops
583	support overloading, however, as well as all functions that use perl to
584	invoke a callback (as in L<AnyEvent::Socket> and L<AnyEvent::DNS> for
585	example).
586		655
587	=item $cv->croak ($error)	656	=item $cv->croak ($error)
588		657
589	Similar to send, but causes all call's to C<< ->recv >> to invoke	658	Similar to send, but causes all call's to C<< ->recv >> to invoke
590	C<Carp::croak> with the given error message/object/scalar.	659	C<Carp::croak> with the given error message/object/scalar.
591		660
592	This can be used to signal any errors to the condition variable	661	This can be used to signal any errors to the condition variable
593	user/consumer.	662	user/consumer. Doing it this way instead of calling C<croak> directly
		663	delays the error detetcion, but has the overwhelmign advantage that it
		664	diagnoses the error at the place where the result is expected, and not
		665	deep in some event clalback without connection to the actual code causing
		666	the problem.
594		667
595	=item $cv->begin ([group callback])	668	=item $cv->begin ([group callback])
596		669
597	=item $cv->end	670	=item $cv->end
598
599	These two methods are EXPERIMENTAL and MIGHT CHANGE.
600		671
601	These two methods can be used to combine many transactions/events into	672	These two methods can be used to combine many transactions/events into
602	one. For example, a function that pings many hosts in parallel might want	673	one. For example, a function that pings many hosts in parallel might want
603	to use a condition variable for the whole process.	674	to use a condition variable for the whole process.
604		675
605	Every call to C<< ->begin >> will increment a counter, and every call to	676	Every call to C<< ->begin >> will increment a counter, and every call to
606	C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end	677	C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end
607	>>, the (last) callback passed to C<begin> will be executed. That callback	678	>>, the (last) callback passed to C<begin> will be executed, passing the
608	is I<supposed> to call C<< ->send >>, but that is not required. If no	679	condvar as first argument. That callback is I<supposed> to call C<< ->send
609	callback was set, C<send> will be called without any arguments.	680	>>, but that is not required. If no group callback was set, C<send> will
		681	be called without any arguments.
610		682
611	Let's clarify this with the ping example:	683	You can think of C<< $cv->send >> giving you an OR condition (one call
		684	sends), while C<< $cv->begin >> and C<< $cv->end >> giving you an AND
		685	condition (all C<begin> calls must be C<end>'ed before the condvar sends).
		686
		687	Let's start with a simple example: you have two I/O watchers (for example,
		688	STDOUT and STDERR for a program), and you want to wait for both streams to
		689	close before activating a condvar:
612		690
613	my $cv = AnyEvent->condvar;	691	my $cv = AnyEvent->condvar;
614		692
		693	$cv->begin; # first watcher
		694	my $w1 = AnyEvent->io (fh => $fh1, cb => sub {
		695	defined sysread $fh1, my $buf, 4096
		696	or $cv->end;
		697	});
		698
		699	$cv->begin; # second watcher
		700	my $w2 = AnyEvent->io (fh => $fh2, cb => sub {
		701	defined sysread $fh2, my $buf, 4096
		702	or $cv->end;
		703	});
		704
		705	$cv->recv;
		706
		707	This works because for every event source (EOF on file handle), there is
		708	one call to C<begin>, so the condvar waits for all calls to C<end> before
		709	sending.
		710
		711	The ping example mentioned above is slightly more complicated, as the
		712	there are results to be passwd back, and the number of tasks that are
		713	begung can potentially be zero:
		714
		715	my $cv = AnyEvent->condvar;
		716
615	my %result;	717	my %result;
616	$cv->begin (sub { $cv->send (\%result) });	718	$cv->begin (sub { shift->send (\%result) });
617		719
618	for my $host (@list_of_hosts) {	720	for my $host (@list_of_hosts) {
619	$cv->begin;	721	$cv->begin;
620	ping_host_then_call_callback $host, sub {	722	ping_host_then_call_callback $host, sub {
621	$result{$host} = ...;	723	$result{$host} = ...;
…		…
636	loop, which serves two important purposes: first, it sets the callback	738	loop, which serves two important purposes: first, it sets the callback
637	to be called once the counter reaches C<0>, and second, it ensures that	739	to be called once the counter reaches C<0>, and second, it ensures that
638	C<send> is called even when C<no> hosts are being pinged (the loop	740	C<send> is called even when C<no> hosts are being pinged (the loop
639	doesn't execute once).	741	doesn't execute once).
640		742
641	This is the general pattern when you "fan out" into multiple subrequests:	743	This is the general pattern when you "fan out" into multiple (but
642	use an outer C<begin>/C<end> pair to set the callback and ensure C<end>	744	potentially none) subrequests: use an outer C<begin>/C<end> pair to set
643	is called at least once, and then, for each subrequest you start, call	745	the callback and ensure C<end> is called at least once, and then, for each
644	C<begin> and for each subrequest you finish, call C<end>.	746	subrequest you start, call C<begin> and for each subrequest you finish,
		747	call C<end>.
645		748
646	=back	749	=back
647		750
648	=head3 METHODS FOR CONSUMERS	751	=head3 METHODS FOR CONSUMERS
649		752
…		…
665	function will call C<croak>.	768	function will call C<croak>.
666		769
667	In list context, all parameters passed to C<send> will be returned,	770	In list context, all parameters passed to C<send> will be returned,
668	in scalar context only the first one will be returned.	771	in scalar context only the first one will be returned.
669		772
		773	Note that doing a blocking wait in a callback is not supported by any
		774	event loop, that is, recursive invocation of a blocking C<< ->recv
		775	>> is not allowed, and the C<recv> call will C<croak> if such a
		776	condition is detected. This condition can be slightly loosened by using
		777	L<Coro::AnyEvent>, which allows you to do a blocking C<< ->recv >> from
		778	any thread that doesn't run the event loop itself.
		779
670	Not all event models support a blocking wait - some die in that case	780	Not all event models support a blocking wait - some die in that case
671	(programs might want to do that to stay interactive), so I<if you are	781	(programs might want to do that to stay interactive), so I<if you are
672	using this from a module, never require a blocking wait>, but let the	782	using this from a module, never require a blocking wait>. Instead, let the
673	caller decide whether the call will block or not (for example, by coupling	783	caller decide whether the call will block or not (for example, by coupling
674	condition variables with some kind of request results and supporting	784	condition variables with some kind of request results and supporting
675	callbacks so the caller knows that getting the result will not block,	785	callbacks so the caller knows that getting the result will not block,
676	while still supporting blocking waits if the caller so desires).	786	while still supporting blocking waits if the caller so desires).
677		787
678	Another reason I<never> to C<< ->recv >> in a module is that you cannot
679	sensibly have two C<< ->recv >>'s in parallel, as that would require
680	multiple interpreters or coroutines/threads, none of which C<AnyEvent>
681	can supply.
682
683	The L<Coro> module, however, I<can> and I<does> supply coroutines and, in
684	fact, L<Coro::AnyEvent> replaces AnyEvent's condvars by coroutine-safe
685	versions and also integrates coroutines into AnyEvent, making blocking
686	C<< ->recv >> calls perfectly safe as long as they are done from another
687	coroutine (one that doesn't run the event loop).
688
689	You can ensure that C<< -recv >> never blocks by setting a callback and	788	You can ensure that C<< -recv >> never blocks by setting a callback and
690	only calling C<< ->recv >> from within that callback (or at a later	789	only calling C<< ->recv >> from within that callback (or at a later
691	time). This will work even when the event loop does not support blocking	790	time). This will work even when the event loop does not support blocking
692	waits otherwise.	791	waits otherwise.
693		792
…		…
699	=item $cb = $cv->cb ($cb->($cv))	798	=item $cb = $cv->cb ($cb->($cv))
700		799
701	This is a mutator function that returns the callback set and optionally	800	This is a mutator function that returns the callback set and optionally
702	replaces it before doing so.	801	replaces it before doing so.
703		802
704	The callback will be called when the condition becomes "true", i.e. when	803	The callback will be called when the condition becomes (or already was)
705	C<send> or C<croak> are called, with the only argument being the condition	804	"true", i.e. when C<send> or C<croak> are called (or were called), with
706	variable itself. Calling C<recv> inside the callback or at any later time	805	the only argument being the condition variable itself. Calling C<recv>
707	is guaranteed not to block.	806	inside the callback or at any later time is guaranteed not to block.
708		807
709	=back	808	=back
710		809
		810	=head1 SUPPORTED EVENT LOOPS/BACKENDS
		811
		812	The available backend classes are (every class has its own manpage):
		813
		814	=over 4
		815
		816	=item Backends that are autoprobed when no other event loop can be found.
		817
		818	EV is the preferred backend when no other event loop seems to be in
		819	use. If EV is not installed, then AnyEvent will fall back to its own
		820	pure-perl implementation, which is available everywhere as it comes with
		821	AnyEvent itself.
		822
		823	AnyEvent::Impl::EV based on EV (interface to libev, best choice).
		824	AnyEvent::Impl::Perl pure-perl implementation, fast and portable.
		825
		826	=item Backends that are transparently being picked up when they are used.
		827
		828	These will be used when they are currently loaded when the first watcher
		829	is created, in which case it is assumed that the application is using
		830	them. This means that AnyEvent will automatically pick the right backend
		831	when the main program loads an event module before anything starts to
		832	create watchers. Nothing special needs to be done by the main program.
		833
		834	AnyEvent::Impl::Event based on Event, very stable, few glitches.
		835	AnyEvent::Impl::Glib based on Glib, slow but very stable.
		836	AnyEvent::Impl::Tk based on Tk, very broken.
		837	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
		838	AnyEvent::Impl::POE based on POE, very slow, some limitations.
		839	AnyEvent::Impl::Irssi used when running within irssi.
		840
		841	=item Backends with special needs.
		842
		843	Qt requires the Qt::Application to be instantiated first, but will
		844	otherwise be picked up automatically. As long as the main program
		845	instantiates the application before any AnyEvent watchers are created,
		846	everything should just work.
		847
		848	AnyEvent::Impl::Qt based on Qt.
		849
		850	Support for IO::Async can only be partial, as it is too broken and
		851	architecturally limited to even support the AnyEvent API. It also
		852	is the only event loop that needs the loop to be set explicitly, so
		853	it can only be used by a main program knowing about AnyEvent. See
		854	L<AnyEvent::Impl::Async> for the gory details.
		855
		856	AnyEvent::Impl::IOAsync based on IO::Async, cannot be autoprobed.
		857
		858	=item Event loops that are indirectly supported via other backends.
		859
		860	Some event loops can be supported via other modules:
		861
		862	There is no direct support for WxWidgets (L<Wx>) or L<Prima>.
		863
		864	B<WxWidgets> has no support for watching file handles. However, you can
		865	use WxWidgets through the POE adaptor, as POE has a Wx backend that simply
		866	polls 20 times per second, which was considered to be too horrible to even
		867	consider for AnyEvent.
		868
		869	B<Prima> is not supported as nobody seems to be using it, but it has a POE
		870	backend, so it can be supported through POE.
		871
		872	AnyEvent knows about both L<Prima> and L<Wx>, however, and will try to
		873	load L<POE> when detecting them, in the hope that POE will pick them up,
		874	in which case everything will be automatic.
		875
		876	=back
		877
711	=head1 GLOBAL VARIABLES AND FUNCTIONS	878	=head1 GLOBAL VARIABLES AND FUNCTIONS
712		879
		880	These are not normally required to use AnyEvent, but can be useful to
		881	write AnyEvent extension modules.
		882
713	=over 4	883	=over 4
714		884
715	=item $AnyEvent::MODEL	885	=item $AnyEvent::MODEL
716		886
717	Contains C<undef> until the first watcher is being created. Then it	887	Contains C<undef> until the first watcher is being created, before the
		888	backend has been autodetected.
		889
718	contains the event model that is being used, which is the name of the	890	Afterwards it contains the event model that is being used, which is the
719	Perl class implementing the model. This class is usually one of the	891	name of the Perl class implementing the model. This class is usually one
720	C<AnyEvent::Impl:xxx> modules, but can be any other class in the case	892	of the C<AnyEvent::Impl:xxx> modules, but can be any other class in the
721	AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode>).	893	case AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode> it
722		894	will be C<urxvt::anyevent>).
723	The known classes so far are:
724
725	AnyEvent::Impl::EV based on EV (an interface to libev, best choice).
726	AnyEvent::Impl::Event based on Event, second best choice.
727	AnyEvent::Impl::Perl pure-perl implementation, fast and portable.
728	AnyEvent::Impl::Glib based on Glib, third-best choice.
729	AnyEvent::Impl::Tk based on Tk, very bad choice.
730	AnyEvent::Impl::Qt based on Qt, cannot be autoprobed (see its docs).
731	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
732	AnyEvent::Impl::POE based on POE, not generic enough for full support.
733
734	There is no support for WxWidgets, as WxWidgets has no support for
735	watching file handles. However, you can use WxWidgets through the
736	POE Adaptor, as POE has a Wx backend that simply polls 20 times per
737	second, which was considered to be too horrible to even consider for
738	AnyEvent. Likewise, other POE backends can be used by AnyEvent by using
739	it's adaptor.
740
741	AnyEvent knows about L<Prima> and L<Wx> and will try to use L<POE> when
742	autodetecting them.
743		895
744	=item AnyEvent::detect	896	=item AnyEvent::detect
745		897
746	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model	898	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model
747	if necessary. You should only call this function right before you would	899	if necessary. You should only call this function right before you would
748	have created an AnyEvent watcher anyway, that is, as late as possible at	900	have created an AnyEvent watcher anyway, that is, as late as possible at
749	runtime.	901	runtime, and not e.g. while initialising of your module.
		902
		903	If you need to do some initialisation before AnyEvent watchers are
		904	created, use C<post_detect>.
750		905
751	=item $guard = AnyEvent::post_detect { BLOCK }	906	=item $guard = AnyEvent::post_detect { BLOCK }
752		907
753	Arranges for the code block to be executed as soon as the event model is	908	Arranges for the code block to be executed as soon as the event model is
754	autodetected (or immediately if this has already happened).	909	autodetected (or immediately if this has already happened).
755		910
		911	The block will be executed I<after> the actual backend has been detected
		912	(C<$AnyEvent::MODEL> is set), but I<before> any watchers have been
		913	created, so it is possible to e.g. patch C<@AnyEvent::ISA> or do
		914	other initialisations - see the sources of L<AnyEvent::Strict> or
		915	L<AnyEvent::AIO> to see how this is used.
		916
		917	The most common usage is to create some global watchers, without forcing
		918	event module detection too early, for example, L<AnyEvent::AIO> creates
		919	and installs the global L<IO::AIO> watcher in a C<post_detect> block to
		920	avoid autodetecting the event module at load time.
		921
756	If called in scalar or list context, then it creates and returns an object	922	If called in scalar or list context, then it creates and returns an object
757	that automatically removes the callback again when it is destroyed. See	923	that automatically removes the callback again when it is destroyed (or
		924	C<undef> when the hook was immediately executed). See L<AnyEvent::AIO> for
758	L<Coro::BDB> for a case where this is useful.	925	a case where this is useful.
		926
		927	Example: Create a watcher for the IO::AIO module and store it in
		928	C<$WATCHER>. Only do so after the event loop is initialised, though.
		929
		930	our WATCHER;
		931
		932	my $guard = AnyEvent::post_detect {
		933	$WATCHER = AnyEvent->io (fh => IO::AIO::poll_fileno, poll => 'r', cb => \&IO::AIO::poll_cb);
		934	};
		935
		936	# the ||= is important in case post_detect immediately runs the block,
		937	# as to not clobber the newly-created watcher. assigning both watcher and
		938	# post_detect guard to the same variable has the advantage of users being
		939	# able to just C<undef $WATCHER> if the watcher causes them grief.
		940
		941	$WATCHER ||= $guard;
759		942
760	=item @AnyEvent::post_detect	943	=item @AnyEvent::post_detect
761		944
762	If there are any code references in this array (you can C<push> to it	945	If there are any code references in this array (you can C<push> to it
763	before or after loading AnyEvent), then they will called directly after	946	before or after loading AnyEvent), then they will called directly after
764	the event loop has been chosen.	947	the event loop has been chosen.
765		948
766	You should check C<$AnyEvent::MODEL> before adding to this array, though:	949	You should check C<$AnyEvent::MODEL> before adding to this array, though:
767	if it contains a true value then the event loop has already been detected,	950	if it is defined then the event loop has already been detected, and the
768	and the array will be ignored.	951	array will be ignored.
769		952
770	Best use C<AnyEvent::post_detect { BLOCK }> instead.	953	Best use C<AnyEvent::post_detect { BLOCK }> when your application allows
		954	it,as it takes care of these details.
		955
		956	This variable is mainly useful for modules that can do something useful
		957	when AnyEvent is used and thus want to know when it is initialised, but do
		958	not need to even load it by default. This array provides the means to hook
		959	into AnyEvent passively, without loading it.
771		960
772	=back	961	=back
773		962
774	=head1 WHAT TO DO IN A MODULE	963	=head1 WHAT TO DO IN A MODULE
775		964
…		…
830		1019
831		1020
832	=head1 OTHER MODULES	1021	=head1 OTHER MODULES
833		1022
834	The following is a non-exhaustive list of additional modules that use	1023	The following is a non-exhaustive list of additional modules that use
835	AnyEvent and can therefore be mixed easily with other AnyEvent modules	1024	AnyEvent as a client and can therefore be mixed easily with other AnyEvent
836	in the same program. Some of the modules come with AnyEvent, some are	1025	modules and other event loops in the same program. Some of the modules
837	available via CPAN.	1026	come with AnyEvent, most are available via CPAN.
838		1027
839	=over 4	1028	=over 4
840		1029
841	=item L<AnyEvent::Util>	1030	=item L<AnyEvent::Util>
842		1031
…		…
851		1040
852	=item L<AnyEvent::Handle>	1041	=item L<AnyEvent::Handle>
853		1042
854	Provide read and write buffers, manages watchers for reads and writes,	1043	Provide read and write buffers, manages watchers for reads and writes,
855	supports raw and formatted I/O, I/O queued and fully transparent and	1044	supports raw and formatted I/O, I/O queued and fully transparent and
856	non-blocking SSL/TLS.	1045	non-blocking SSL/TLS (via L<AnyEvent::TLS>.
857		1046
858	=item L<AnyEvent::DNS>	1047	=item L<AnyEvent::DNS>
859		1048
860	Provides rich asynchronous DNS resolver capabilities.	1049	Provides rich asynchronous DNS resolver capabilities.
861		1050
…		…
889		1078
890	=item L<AnyEvent::GPSD>	1079	=item L<AnyEvent::GPSD>
891		1080
892	A non-blocking interface to gpsd, a daemon delivering GPS information.	1081	A non-blocking interface to gpsd, a daemon delivering GPS information.
893		1082
		1083	=item L<AnyEvent::IRC>
		1084
		1085	AnyEvent based IRC client module family (replacing the older Net::IRC3).
		1086
		1087	=item L<AnyEvent::XMPP>
		1088
		1089	AnyEvent based XMPP (Jabber protocol) module family (replacing the older
		1090	Net::XMPP2>.
		1091
894	=item L<AnyEvent::IGS>	1092	=item L<AnyEvent::IGS>
895		1093
896	A non-blocking interface to the Internet Go Server protocol (used by	1094	A non-blocking interface to the Internet Go Server protocol (used by
897	L<App::IGS>).	1095	L<App::IGS>).
898		1096
899	=item L<AnyEvent::IRC>
900
901	AnyEvent based IRC client module family (replacing the older Net::IRC3).
902
903	=item L<Net::XMPP2>
904
905	AnyEvent based XMPP (Jabber protocol) module family.
906
907	=item L<Net::FCP>	1097	=item L<Net::FCP>
908		1098
909	AnyEvent-based implementation of the Freenet Client Protocol, birthplace	1099	AnyEvent-based implementation of the Freenet Client Protocol, birthplace
910	of AnyEvent.	1100	of AnyEvent.
911		1101
…		…
915		1105
916	=item L<Coro>	1106	=item L<Coro>
917		1107
918	Has special support for AnyEvent via L<Coro::AnyEvent>.	1108	Has special support for AnyEvent via L<Coro::AnyEvent>.
919		1109
920	=item L<IO::Lambda>
921
922	The lambda approach to I/O - don't ask, look there. Can use AnyEvent.
923
924	=back	1110	=back
925		1111
926	=cut	1112	=cut
927		1113
928	package AnyEvent;	1114	package AnyEvent;
929		1115
930	no warnings;	1116	# basically a tuned-down version of common::sense
		1117	sub common_sense {
		1118	# from common:.sense 1.0
		1119	${^WARNING_BITS} = "\xfc\x3f\xf3\x00\x0f\xf3\xcf\xc0\xf3\xfc\x33\x03";
931	use strict qw(vars subs);	1120	# use strict vars subs
		1121	$^H |= 0x00000600;
		1122	}
932		1123
		1124	BEGIN { AnyEvent::common_sense }
		1125
933	use Carp;	1126	use Carp ();
934		1127
935	our $VERSION = 4.41;	1128	our $VERSION = '5.202';
936	our $MODEL;	1129	our $MODEL;
937		1130
938	our $AUTOLOAD;	1131	our $AUTOLOAD;
939	our @ISA;	1132	our @ISA;
940		1133
941	our @REGISTRY;	1134	our @REGISTRY;
942		1135
943	our $WIN32;	1136	our $WIN32;
944		1137
		1138	our $VERBOSE;
		1139
945	BEGIN {	1140	BEGIN {
946	my $win32 = ! ! ($^O =~ /mswin32/i);	1141	eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }";
947	eval "sub WIN32(){ $win32 }";	1142	eval "sub TAINT(){ " . (${^TAINT}*1) . " }";
948	}
949		1143
		1144	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}
		1145	if ${^TAINT};
		1146
950	our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1;	1147	$VERBOSE = $ENV{PERL_ANYEVENT_VERBOSE}*1;
		1148
		1149	}
		1150
		1151	our $MAX_SIGNAL_LATENCY = 10;
951		1152
952	our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred	1153	our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred
953		1154
954	{	1155	{
955	my $idx;	1156	my $idx;
…		…
957	for reverse split /\s*,\s*/,	1158	for reverse split /\s*,\s*/,
958	$ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";	1159	$ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";
959	}	1160	}
960		1161
961	my @models = (	1162	my @models = (
962	[EV:: => AnyEvent::Impl::EV::],	1163	[EV:: => AnyEvent::Impl::EV:: , 1],
963	[Event:: => AnyEvent::Impl::Event::],
964	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::],	1164	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl:: , 1],
965	# everything below here will not be autoprobed	1165	# everything below here will not (normally) be autoprobed
966	# as the pureperl backend should work everywhere	1166	# as the pureperl backend should work everywhere
967	# and is usually faster	1167	# and is usually faster
		1168	[Event:: => AnyEvent::Impl::Event::, 1],
		1169	[Glib:: => AnyEvent::Impl::Glib:: , 1], # becomes extremely slow with many watchers
		1170	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
		1171	[Irssi:: => AnyEvent::Impl::Irssi::], # Irssi has a bogus "Event" package
968	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles	1172	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
969	[Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers
970	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
971	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program	1173	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program
972	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza	1174	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
973	[Wx:: => AnyEvent::Impl::POE::],	1175	[Wx:: => AnyEvent::Impl::POE::],
974	[Prima:: => AnyEvent::Impl::POE::],	1176	[Prima:: => AnyEvent::Impl::POE::],
		1177	# IO::Async is just too broken - we would need workarounds for its
		1178	# byzantine signal and broken child handling, among others.
		1179	# IO::Async is rather hard to detect, as it doesn't have any
		1180	# obvious default class.
		1181	[IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program
		1182	[IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program
		1183	[IO::Async::Notifier:: => AnyEvent::Impl::IOAsync::], # requires special main program
		1184	[AnyEvent::Impl::IOAsync:: => AnyEvent::Impl::IOAsync::], # requires special main program
975	);	1185	);
976		1186
977	our %method = map +($_ => 1),	1187	our %method = map +($_ => 1),
978	qw(io timer time now now_update signal child idle condvar one_event DESTROY);	1188	qw(io timer time now now_update signal child idle condvar one_event DESTROY);
979		1189
…		…
983	my ($cb) = @_;	1193	my ($cb) = @_;
984		1194
985	if ($MODEL) {	1195	if ($MODEL) {
986	$cb->();	1196	$cb->();
987		1197
988	1	1198	undef
989	} else {	1199	} else {
990	push @post_detect, $cb;	1200	push @post_detect, $cb;
991		1201
992	defined wantarray	1202	defined wantarray
993	? bless \$cb, "AnyEvent::Util::postdetect"	1203	? bless \$cb, "AnyEvent::Util::postdetect"
…		…
999	@post_detect = grep $_ != ${$_[0]}, @post_detect;	1209	@post_detect = grep $_ != ${$_[0]}, @post_detect;
1000	}	1210	}
1001		1211
1002	sub detect() {	1212	sub detect() {
1003	unless ($MODEL) {	1213	unless ($MODEL) {
1004	no strict 'refs';
1005	local $SIG{__DIE__};	1214	local $SIG{__DIE__};
1006		1215
1007	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {	1216	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {
1008	my $model = "AnyEvent::Impl::$1";	1217	my $model = "AnyEvent::Impl::$1";
1009	if (eval "require $model") {	1218	if (eval "require $model") {
1010	$MODEL = $model;	1219	$MODEL = $model;
1011	warn "AnyEvent: loaded model '$model' (forced by \$PERL_ANYEVENT_MODEL), using it.\n" if $verbose > 1;	1220	warn "AnyEvent: loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.\n" if $VERBOSE >= 2;
1012	} else {	1221	} else {
1013	warn "AnyEvent: unable to load model '$model' (from \$PERL_ANYEVENT_MODEL):\n$@" if $verbose;	1222	warn "AnyEvent: unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@" if $VERBOSE;
1014	}	1223	}
1015	}	1224	}
1016		1225
1017	# check for already loaded models	1226	# check for already loaded models
1018	unless ($MODEL) {	1227	unless ($MODEL) {
1019	for (@REGISTRY, @models) {	1228	for (@REGISTRY, @models) {
1020	my ($package, $model) = @$_;	1229	my ($package, $model) = @$_;
1021	if (${"$package\::VERSION"} > 0) {	1230	if (${"$package\::VERSION"} > 0) {
1022	if (eval "require $model") {	1231	if (eval "require $model") {
1023	$MODEL = $model;	1232	$MODEL = $model;
1024	warn "AnyEvent: autodetected model '$model', using it.\n" if $verbose > 1;	1233	warn "AnyEvent: autodetected model '$model', using it.\n" if $VERBOSE >= 2;
1025	last;	1234	last;
1026	}	1235	}
1027	}	1236	}
1028	}	1237	}
1029		1238
1030	unless ($MODEL) {	1239	unless ($MODEL) {
1031	# try to load a model	1240	# try to autoload a model
1032
1033	for (@REGISTRY, @models) {	1241	for (@REGISTRY, @models) {
1034	my ($package, $model) = @$_;	1242	my ($package, $model, $autoload) = @$_;
		1243	if (
		1244	$autoload
1035	if (eval "require $package"	1245	and eval "require $package"
1036	and ${"$package\::VERSION"} > 0	1246	and ${"$package\::VERSION"} > 0
1037	and eval "require $model") {	1247	and eval "require $model"
		1248	) {
1038	$MODEL = $model;	1249	$MODEL = $model;
1039	warn "AnyEvent: autoprobed model '$model', using it.\n" if $verbose > 1;	1250	warn "AnyEvent: autoloaded model '$model', using it.\n" if $VERBOSE >= 2;
1040	last;	1251	last;
1041	}	1252	}
1042	}	1253	}
1043		1254
1044	$MODEL	1255	$MODEL
…		…
1060		1271
1061	sub AUTOLOAD {	1272	sub AUTOLOAD {
1062	(my $func = $AUTOLOAD) =~ s/.*://;	1273	(my $func = $AUTOLOAD) =~ s/.*://;
1063		1274
1064	$method{$func}	1275	$method{$func}
1065	or croak "$func: not a valid method for AnyEvent objects";	1276	or Carp::croak "$func: not a valid method for AnyEvent objects";
1066		1277
1067	detect unless $MODEL;	1278	detect unless $MODEL;
1068		1279
1069	my $class = shift;	1280	my $class = shift;
1070	$class->$func (@_);	1281	$class->$func (@_);
1071	}	1282	}
1072		1283
1073	# utility function to dup a filehandle. this is used by many backends	1284	# utility function to dup a filehandle. this is used by many backends
1074	# to support binding more than one watcher per filehandle (they usually	1285	# to support binding more than one watcher per filehandle (they usually
1075	# allow only one watcher per fd, so we dup it to get a different one).	1286	# allow only one watcher per fd, so we dup it to get a different one).
1076	sub _dupfh($$$$) {	1287	sub _dupfh($$;$$) {
1077	my ($poll, $fh, $r, $w) = @_;	1288	my ($poll, $fh, $r, $w) = @_;
1078		1289
1079	# cygwin requires the fh mode to be matching, unix doesn't	1290	# cygwin requires the fh mode to be matching, unix doesn't
1080	my ($rw, $mode) = $poll eq "r" ? ($r, "<")	1291	my ($rw, $mode) = $poll eq "r" ? ($r, "<&") : ($w, ">&");
1081	: $poll eq "w" ? ($w, ">")
1082	: Carp::croak "AnyEvent->io requires poll set to either 'r' or 'w'";
1083		1292
1084	open my $fh2, "$mode&" . fileno $fh	1293	open my $fh2, $mode, $fh
1085	or die "cannot dup() filehandle: $!,";	1294	or die "AnyEvent->io: cannot dup() filehandle in mode '$poll': $!,";
1086		1295
1087	# we assume CLOEXEC is already set by perl in all important cases	1296	# we assume CLOEXEC is already set by perl in all important cases
1088		1297
1089	($fh2, $rw)	1298	($fh2, $rw)
1090	}	1299	}
1091		1300
		1301	=head1 SIMPLIFIED AE API
		1302
		1303	Starting with version 5.0, AnyEvent officially supports a second, much
		1304	simpler, API that is designed to reduce the calling, typing and memory
		1305	overhead.
		1306
		1307	See the L<AE> manpage for details.
		1308
		1309	=cut
		1310
		1311	package AE;
		1312
		1313	our $VERSION = $AnyEvent::VERSION;
		1314
		1315	sub io($$$) {
		1316	AnyEvent->io (fh => $_[0], poll => $_[1] ? "w" : "r", cb => $_[2])
		1317	}
		1318
		1319	sub timer($$$) {
		1320	AnyEvent->timer (after => $_[0], interval => $_[1], cb => $_[2])
		1321	}
		1322
		1323	sub signal($$) {
		1324	AnyEvent->signal (signal => $_[0], cb => $_[1])
		1325	}
		1326
		1327	sub child($$) {
		1328	AnyEvent->child (pid => $_[0], cb => $_[1])
		1329	}
		1330
		1331	sub idle($) {
		1332	AnyEvent->idle (cb => $_[0])
		1333	}
		1334
		1335	sub cv(;&) {
		1336	AnyEvent->condvar (@_ ? (cb => $_[0]) : ())
		1337	}
		1338
		1339	sub now() {
		1340	AnyEvent->now
		1341	}
		1342
		1343	sub now_update() {
		1344	AnyEvent->now_update
		1345	}
		1346
		1347	sub time() {
		1348	AnyEvent->time
		1349	}
		1350
1092	package AnyEvent::Base;	1351	package AnyEvent::Base;
1093		1352
1094	# default implementations for many methods	1353	# default implementations for many methods
1095		1354
1096	BEGIN {	1355	sub _time() {
		1356	# probe for availability of Time::HiRes
1097	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {	1357	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {
		1358	warn "AnyEvent: using Time::HiRes for sub-second timing accuracy.\n" if $VERBOSE >= 8;
1098	*_time = \&Time::HiRes::time;	1359	*_time = \&Time::HiRes::time;
1099	# if (eval "use POSIX (); (POSIX::times())...	1360	# if (eval "use POSIX (); (POSIX::times())...
1100	} else {	1361	} else {
		1362	warn "AnyEvent: using built-in time(), WARNING, no sub-second resolution!\n" if $VERBOSE;
1101	*_time = sub { time }; # epic fail	1363	*_time = sub { time }; # epic fail
1102	}	1364	}
		1365
		1366	&_time
1103	}	1367	}
1104		1368
1105	sub time { _time }	1369	sub time { _time }
1106	sub now { _time }	1370	sub now { _time }
1107	sub now_update { }	1371	sub now_update { }
…		…
1112	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"	1376	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"
1113	}	1377	}
1114		1378
1115	# default implementation for ->signal	1379	# default implementation for ->signal
1116		1380
		1381	our $HAVE_ASYNC_INTERRUPT;
		1382
		1383	sub _have_async_interrupt() {
		1384	$HAVE_ASYNC_INTERRUPT = 1*(!$ENV{PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT}
		1385	&& eval "use Async::Interrupt 1.02 (); 1")
		1386	unless defined $HAVE_ASYNC_INTERRUPT;
		1387
		1388	$HAVE_ASYNC_INTERRUPT
		1389	}
		1390
1117	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);	1391	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);
		1392	our (%SIG_ASY, %SIG_ASY_W);
		1393	our ($SIG_COUNT, $SIG_TW);
1118		1394
1119	sub _signal_exec {	1395	sub _signal_exec {
		1396	$HAVE_ASYNC_INTERRUPT
		1397	? $SIGPIPE_R->drain
1120	sysread $SIGPIPE_R, my $dummy, 4;	1398	: sysread $SIGPIPE_R, (my $dummy), 9;
1121		1399
1122	while (%SIG_EV) {	1400	while (%SIG_EV) {
1123	for (keys %SIG_EV) {	1401	for (keys %SIG_EV) {
1124	delete $SIG_EV{$_};	1402	delete $SIG_EV{$_};
1125	$_->() for values %{ $SIG_CB{$_} || {} };	1403	$_->() for values %{ $SIG_CB{$_} || {} };
1126	}	1404	}
1127	}	1405	}
1128	}	1406	}
1129		1407
		1408	# install a dummy wakeup watcher to reduce signal catching latency
		1409	sub _sig_add() {
		1410	unless ($SIG_COUNT++) {
		1411	# try to align timer on a full-second boundary, if possible
		1412	my $NOW = AE::now;
		1413
		1414	$SIG_TW = AE::timer
		1415	$MAX_SIGNAL_LATENCY - ($NOW - int $NOW),
		1416	$MAX_SIGNAL_LATENCY,
		1417	sub { } # just for the PERL_ASYNC_CHECK
		1418	;
		1419	}
		1420	}
		1421
		1422	sub _sig_del {
		1423	undef $SIG_TW
		1424	unless --$SIG_COUNT;
		1425	}
		1426
		1427	our $_sig_name_init; $_sig_name_init = sub {
		1428	eval q{ # poor man's autoloading
		1429	undef $_sig_name_init;
		1430
		1431	if (_have_async_interrupt) {
		1432	*sig2num = \&Async::Interrupt::sig2num;
		1433	*sig2name = \&Async::Interrupt::sig2name;
		1434	} else {
		1435	require Config;
		1436
		1437	my %signame2num;
		1438	@signame2num{ split ' ', $Config::Config{sig_name} }
		1439	= split ' ', $Config::Config{sig_num};
		1440
		1441	my @signum2name;
		1442	@signum2name[values %signame2num] = keys %signame2num;
		1443
		1444	*sig2num = sub($) {
		1445	$_[0] > 0 ? shift : $signame2num{+shift}
		1446	};
		1447	*sig2name = sub ($) {
		1448	$_[0] > 0 ? $signum2name[+shift] : shift
		1449	};
		1450	}
		1451	};
		1452	die if $@;
		1453	};
		1454
		1455	sub sig2num ($) { &$_sig_name_init; &sig2num }
		1456	sub sig2name($) { &$_sig_name_init; &sig2name }
		1457
1130	sub signal {	1458	sub signal {
1131	my (undef, %arg) = @_;	1459	eval q{ # poor man's autoloading {}
		1460	# probe for availability of Async::Interrupt
		1461	if (_have_async_interrupt) {
		1462	warn "AnyEvent: using Async::Interrupt for race-free signal handling.\n" if $VERBOSE >= 8;
1132		1463
1133	unless ($SIGPIPE_R) {	1464	$SIGPIPE_R = new Async::Interrupt::EventPipe;
1134	require Fcntl;	1465	$SIG_IO = AE::io $SIGPIPE_R->fileno, 0, \&_signal_exec;
1135		1466
1136	if (AnyEvent::WIN32) {
1137	require AnyEvent::Util;
1138
1139	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
1140	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R) if $SIGPIPE_R;
1141	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W) if $SIGPIPE_W; # just in case
1142	} else {	1467	} else {
		1468	warn "AnyEvent: using emulated perl signal handling with latency timer.\n" if $VERBOSE >= 8;
		1469
		1470	require Fcntl;
		1471
		1472	if (AnyEvent::WIN32) {
		1473	require AnyEvent::Util;
		1474
		1475	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
		1476	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R, 1) if $SIGPIPE_R;
		1477	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W, 1) if $SIGPIPE_W; # just in case
		1478	} else {
1143	pipe $SIGPIPE_R, $SIGPIPE_W;	1479	pipe $SIGPIPE_R, $SIGPIPE_W;
1144	fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R;	1480	fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R;
1145	fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case	1481	fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case
		1482
		1483	# not strictly required, as $^F is normally 2, but let's make sure...
		1484	fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
		1485	fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
		1486	}
		1487
		1488	$SIGPIPE_R
		1489	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";
		1490
		1491	$SIG_IO = AE::io $SIGPIPE_R, 0, \&_signal_exec;
1146	}	1492	}
1147		1493
1148	$SIGPIPE_R	1494	*signal = sub {
1149	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";	1495	my (undef, %arg) = @_;
1150		1496
1151	# not strictly required, as $^F is normally 2, but let's make sure...
1152	fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
1153	fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
1154
1155	$SIG_IO = AnyEvent->io (fh => $SIGPIPE_R, poll => "r", cb => \&_signal_exec);
1156	}
1157
1158	my $signal = uc $arg{signal}	1497	my $signal = uc $arg{signal}
1159	or Carp::croak "required option 'signal' is missing";	1498	or Carp::croak "required option 'signal' is missing";
1160		1499
		1500	if ($HAVE_ASYNC_INTERRUPT) {
		1501	# async::interrupt
		1502
		1503	$signal = sig2num $signal;
1161	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};	1504	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
		1505
		1506	$SIG_ASY{$signal} ||= new Async::Interrupt
		1507	cb => sub { undef $SIG_EV{$signal} },
		1508	signal => $signal,
		1509	pipe => [$SIGPIPE_R->filenos],
		1510	pipe_autodrain => 0,
		1511	;
		1512
		1513	} else {
		1514	# pure perl
		1515
		1516	# AE::Util has been loaded in signal
		1517	$signal = sig2name $signal;
		1518	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
		1519
1162	$SIG{$signal} ||= sub {	1520	$SIG{$signal} ||= sub {
1163	local $!;	1521	local $!;
1164	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;	1522	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;
1165	undef $SIG_EV{$signal};	1523	undef $SIG_EV{$signal};
		1524	};
		1525
		1526	# can't do signal processing without introducing races in pure perl,
		1527	# so limit the signal latency.
		1528	_sig_add;
		1529	}
		1530
		1531	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
		1532	};
		1533
		1534	*AnyEvent::Base::signal::DESTROY = sub {
		1535	my ($signal, $cb) = @{$_[0]};
		1536
		1537	_sig_del;
		1538
		1539	delete $SIG_CB{$signal}{$cb};
		1540
		1541	$HAVE_ASYNC_INTERRUPT
		1542	? delete $SIG_ASY{$signal}
		1543	: # delete doesn't work with older perls - they then
		1544	# print weird messages, or just unconditionally exit
		1545	# instead of getting the default action.
		1546	undef $SIG{$signal}
		1547	unless keys %{ $SIG_CB{$signal} };
		1548	};
1166	};	1549	};
1167		1550	die if $@;
1168	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"	1551	&signal
1169	}
1170
1171	sub AnyEvent::Base::signal::DESTROY {
1172	my ($signal, $cb) = @{$_[0]};
1173
1174	delete $SIG_CB{$signal}{$cb};
1175
1176	$SIG{$signal} = 'DEFAULT' unless keys %{ $SIG_CB{$signal} };
1177	}	1552	}
1178		1553
1179	# default implementation for ->child	1554	# default implementation for ->child
1180		1555
1181	our %PID_CB;	1556	our %PID_CB;
1182	our $CHLD_W;	1557	our $CHLD_W;
1183	our $CHLD_DELAY_W;	1558	our $CHLD_DELAY_W;
1184	our $PID_IDLE;
1185	our $WNOHANG;	1559	our $WNOHANG;
1186		1560
1187	sub _child_wait {	1561	sub _emit_childstatus($$) {
1188	while (0 < (my $pid = waitpid -1, $WNOHANG)) {	1562	my (undef, $rpid, $rstatus) = @_;
		1563
		1564	$_->($rpid, $rstatus)
1189	$_->($pid, $?) for (values %{ $PID_CB{$pid} || {} }),	1565	for values %{ $PID_CB{$rpid} || {} },
1190	(values %{ $PID_CB{0} || {} });	1566	values %{ $PID_CB{0} || {} };
1191	}
1192
1193	undef $PID_IDLE;
1194	}	1567	}
1195		1568
1196	sub _sigchld {	1569	sub _sigchld {
1197	# make sure we deliver these changes "synchronous" with the event loop.	1570	my $pid;
1198	$CHLD_DELAY_W ||= AnyEvent->timer (after => 0, cb => sub {	1571
1199	undef $CHLD_DELAY_W;	1572	AnyEvent->_emit_childstatus ($pid, $?)
1200	&_child_wait;	1573	while ($pid = waitpid -1, $WNOHANG) > 0;
1201	});
1202	}	1574	}
1203		1575
1204	sub child {	1576	sub child {
1205	my (undef, %arg) = @_;	1577	my (undef, %arg) = @_;
1206		1578
1207	defined (my $pid = $arg{pid} + 0)	1579	defined (my $pid = $arg{pid} + 0)
1208	or Carp::croak "required option 'pid' is missing";	1580	or Carp::croak "required option 'pid' is missing";
1209		1581
1210	$PID_CB{$pid}{$arg{cb}} = $arg{cb};	1582	$PID_CB{$pid}{$arg{cb}} = $arg{cb};
1211		1583
1212	unless ($WNOHANG) {	1584	# WNOHANG is almost cetrainly 1 everywhere
		1585	$WNOHANG ||= $^O =~ /^(?:openbsd|netbsd|linux|freebsd|cygwin|MSWin32)$/
		1586	? 1
1213	$WNOHANG = eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1;	1587	: eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1;
1214	}
1215		1588
1216	unless ($CHLD_W) {	1589	unless ($CHLD_W) {
1217	$CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld);	1590	$CHLD_W = AE::signal CHLD => \&_sigchld;
1218	# child could be a zombie already, so make at least one round	1591	# child could be a zombie already, so make at least one round
1219	&_sigchld;	1592	&_sigchld;
1220	}	1593	}
1221		1594
1222	bless [$pid, $arg{cb}], "AnyEvent::Base::child"	1595	bless [$pid, $arg{cb}], "AnyEvent::Base::child"
…		…
1230		1603
1231	undef $CHLD_W unless keys %PID_CB;	1604	undef $CHLD_W unless keys %PID_CB;
1232	}	1605	}
1233		1606
1234	# idle emulation is done by simply using a timer, regardless	1607	# idle emulation is done by simply using a timer, regardless
1235	# of whether the proces sis idle or not, and not letting	1608	# of whether the process is idle or not, and not letting
1236	# the callback use more than 50% of the time.	1609	# the callback use more than 50% of the time.
1237	sub idle {	1610	sub idle {
1238	my (undef, %arg) = @_;	1611	my (undef, %arg) = @_;
1239		1612
1240	my ($cb, $w, $rcb) = $arg{cb};	1613	my ($cb, $w, $rcb) = $arg{cb};
…		…
1248	# never use more then 50% of the time for the idle watcher,	1621	# never use more then 50% of the time for the idle watcher,
1249	# within some limits	1622	# within some limits
1250	$w = 0.0001 if $w < 0.0001;	1623	$w = 0.0001 if $w < 0.0001;
1251	$w = 5 if $w > 5;	1624	$w = 5 if $w > 5;
1252		1625
1253	$w = AnyEvent->timer (after => $w, cb => $rcb);	1626	$w = AE::timer $w, 0, $rcb;
1254	} else {	1627	} else {
1255	# clean up...	1628	# clean up...
1256	undef $w;	1629	undef $w;
1257	undef $rcb;	1630	undef $rcb;
1258	}	1631	}
1259	};	1632	};
1260		1633
1261	$w = AnyEvent->timer (after => 0.05, cb => $rcb);	1634	$w = AE::timer 0.05, 0, $rcb;
1262		1635
1263	bless \\$cb, "AnyEvent::Base::idle"	1636	bless \\$cb, "AnyEvent::Base::idle"
1264	}	1637	}
1265		1638
1266	sub AnyEvent::Base::idle::DESTROY {	1639	sub AnyEvent::Base::idle::DESTROY {
…		…
1271		1644
1272	our @ISA = AnyEvent::CondVar::Base::;	1645	our @ISA = AnyEvent::CondVar::Base::;
1273		1646
1274	package AnyEvent::CondVar::Base;	1647	package AnyEvent::CondVar::Base;
1275		1648
1276	use overload	1649	#use overload
1277	'&{}' => sub { my $self = shift; sub { $self->send (@_) } },	1650	# '&{}' => sub { my $self = shift; sub { $self->send (@_) } },
1278	fallback => 1;	1651	# fallback => 1;
		1652
		1653	# save 300+ kilobytes by dirtily hardcoding overloading
		1654	${"AnyEvent::CondVar::Base::OVERLOAD"}{dummy}++; # Register with magic by touching.
		1655	*{'AnyEvent::CondVar::Base::()'} = sub { }; # "Make it findable via fetchmethod."
		1656	*{'AnyEvent::CondVar::Base::(&{}'} = sub { my $self = shift; sub { $self->send (@_) } }; # &{}
		1657	${'AnyEvent::CondVar::Base::()'} = 1; # fallback
		1658
		1659	our $WAITING;
1279		1660
1280	sub _send {	1661	sub _send {
1281	# nop	1662	# nop
1282	}	1663	}
1283		1664
…		…
1296	sub ready {	1677	sub ready {
1297	$_[0]{_ae_sent}	1678	$_[0]{_ae_sent}
1298	}	1679	}
1299		1680
1300	sub _wait {	1681	sub _wait {
		1682	$WAITING
		1683	and !$_[0]{_ae_sent}
		1684	and Carp::croak "AnyEvent::CondVar: recursive blocking wait detected";
		1685
		1686	local $WAITING = 1;
1301	AnyEvent->one_event while !$_[0]{_ae_sent};	1687	AnyEvent->one_event while !$_[0]{_ae_sent};
1302	}	1688	}
1303		1689
1304	sub recv {	1690	sub recv {
1305	$_[0]->_wait;	1691	$_[0]->_wait;
…		…
1307	Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak};	1693	Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak};
1308	wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0]	1694	wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0]
1309	}	1695	}
1310		1696
1311	sub cb {	1697	sub cb {
1312	$_[0]{_ae_cb} = $_[1] if @_ > 1;	1698	my $cv = shift;
		1699
		1700	@_
		1701	and $cv->{_ae_cb} = shift
		1702	and $cv->{_ae_sent}
		1703	and (delete $cv->{_ae_cb})->($cv);
		1704
1313	$_[0]{_ae_cb}	1705	$cv->{_ae_cb}
1314	}	1706	}
1315		1707
1316	sub begin {	1708	sub begin {
1317	++$_[0]{_ae_counter};	1709	++$_[0]{_ae_counter};
1318	$_[0]{_ae_end_cb} = $_[1] if @_ > 1;	1710	$_[0]{_ae_end_cb} = $_[1] if @_ > 1;
…		…
1346	so on.	1738	so on.
1347		1739
1348	=head1 ENVIRONMENT VARIABLES	1740	=head1 ENVIRONMENT VARIABLES
1349		1741
1350	The following environment variables are used by this module or its	1742	The following environment variables are used by this module or its
1351	submodules:	1743	submodules.
		1744
		1745	Note that AnyEvent will remove I<all> environment variables starting with
		1746	C<PERL_ANYEVENT_> from C<%ENV> when it is loaded while taint mode is
		1747	enabled.
1352		1748
1353	=over 4	1749	=over 4
1354		1750
1355	=item C<PERL_ANYEVENT_VERBOSE>	1751	=item C<PERL_ANYEVENT_VERBOSE>
1356		1752
…		…
1363	C<PERL_ANYEVENT_MODEL>.	1759	C<PERL_ANYEVENT_MODEL>.
1364		1760
1365	When set to C<2> or higher, cause AnyEvent to report to STDERR which event	1761	When set to C<2> or higher, cause AnyEvent to report to STDERR which event
1366	model it chooses.	1762	model it chooses.
1367		1763
		1764	When set to C<8> or higher, then AnyEvent will report extra information on
		1765	which optional modules it loads and how it implements certain features.
		1766
1368	=item C<PERL_ANYEVENT_STRICT>	1767	=item C<PERL_ANYEVENT_STRICT>
1369		1768
1370	AnyEvent does not do much argument checking by default, as thorough	1769	AnyEvent does not do much argument checking by default, as thorough
1371	argument checking is very costly. Setting this variable to a true value	1770	argument checking is very costly. Setting this variable to a true value
1372	will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly	1771	will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly
1373	check the arguments passed to most method calls. If it finds any problems	1772	check the arguments passed to most method calls. If it finds any problems,
1374	it will croak.	1773	it will croak.
1375		1774
1376	In other words, enables "strict" mode.	1775	In other words, enables "strict" mode.
1377		1776
1378	Unlike C<use strict>, it is definitely recommended ot keep it off in	1777	Unlike C<use strict> (or it's modern cousin, C<< use L<common::sense>
1379	production. Keeping C<PERL_ANYEVENT_STRICT=1> in your environment while	1778	>>, it is definitely recommended to keep it off in production. Keeping
1380	developing programs can be very useful, however.	1779	C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs
		1780	can be very useful, however.
1381		1781
1382	=item C<PERL_ANYEVENT_MODEL>	1782	=item C<PERL_ANYEVENT_MODEL>
1383		1783
1384	This can be used to specify the event model to be used by AnyEvent, before	1784	This can be used to specify the event model to be used by AnyEvent, before
1385	auto detection and -probing kicks in. It must be a string consisting	1785	auto detection and -probing kicks in. It must be a string consisting
…		…
1428		1828
1429	=item C<PERL_ANYEVENT_MAX_FORKS>	1829	=item C<PERL_ANYEVENT_MAX_FORKS>
1430		1830
1431	The maximum number of child processes that C<AnyEvent::Util::fork_call>	1831	The maximum number of child processes that C<AnyEvent::Util::fork_call>
1432	will create in parallel.	1832	will create in parallel.
		1833
		1834	=item C<PERL_ANYEVENT_MAX_OUTSTANDING_DNS>
		1835
		1836	The default value for the C<max_outstanding> parameter for the default DNS
		1837	resolver - this is the maximum number of parallel DNS requests that are
		1838	sent to the DNS server.
		1839
		1840	=item C<PERL_ANYEVENT_RESOLV_CONF>
		1841
		1842	The file to use instead of F</etc/resolv.conf> (or OS-specific
		1843	configuration) in the default resolver. When set to the empty string, no
		1844	default config will be used.
		1845
		1846	=item C<PERL_ANYEVENT_CA_FILE>, C<PERL_ANYEVENT_CA_PATH>.
		1847
		1848	When neither C<ca_file> nor C<ca_path> was specified during
		1849	L<AnyEvent::TLS> context creation, and either of these environment
		1850	variables exist, they will be used to specify CA certificate locations
		1851	instead of a system-dependent default.
		1852
		1853	=item C<PERL_ANYEVENT_AVOID_GUARD> and C<PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT>
		1854
		1855	When these are set to C<1>, then the respective modules are not
		1856	loaded. Mostly good for testing AnyEvent itself.
1433		1857
1434	=back	1858	=back
1435		1859
1436	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE	1860	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE
1437		1861
…		…
1495	warn "read: $input\n"; # output what has been read	1919	warn "read: $input\n"; # output what has been read
1496	$cv->send if $input =~ /^q/i; # quit program if /^q/i	1920	$cv->send if $input =~ /^q/i; # quit program if /^q/i
1497	},	1921	},
1498	);	1922	);
1499		1923
1500	my $time_watcher; # can only be used once
1501
1502	sub new_timer {
1503	$timer = AnyEvent->timer (after => 1, cb => sub {	1924	my $time_watcher = AnyEvent->timer (after => 1, interval => 1, cb => sub {
1504	warn "timeout\n"; # print 'timeout' about every second	1925	warn "timeout\n"; # print 'timeout' at most every second
1505	&new_timer; # and restart the time
1506	});	1926	});
1507	}
1508
1509	new_timer; # create first timer
1510		1927
1511	$cv->recv; # wait until user enters /^q/i	1928	$cv->recv; # wait until user enters /^q/i
1512		1929
1513	=head1 REAL-WORLD EXAMPLE	1930	=head1 REAL-WORLD EXAMPLE
1514		1931
…		…
1645	through AnyEvent. The benchmark creates a lot of timers (with a zero	2062	through AnyEvent. The benchmark creates a lot of timers (with a zero
1646	timeout) and I/O watchers (watching STDOUT, a pty, to become writable,	2063	timeout) and I/O watchers (watching STDOUT, a pty, to become writable,
1647	which it is), lets them fire exactly once and destroys them again.	2064	which it is), lets them fire exactly once and destroys them again.
1648		2065
1649	Source code for this benchmark is found as F<eg/bench> in the AnyEvent	2066	Source code for this benchmark is found as F<eg/bench> in the AnyEvent
1650	distribution.	2067	distribution. It uses the L<AE> interface, which makes a real difference
		2068	for the EV and Perl backends only.
1651		2069
1652	=head3 Explanation of the columns	2070	=head3 Explanation of the columns
1653		2071
1654	I<watcher> is the number of event watchers created/destroyed. Since	2072	I<watcher> is the number of event watchers created/destroyed. Since
1655	different event models feature vastly different performances, each event	2073	different event models feature vastly different performances, each event
…		…
1676	watcher.	2094	watcher.
1677		2095
1678	=head3 Results	2096	=head3 Results
1679		2097
1680	name watchers bytes create invoke destroy comment	2098	name watchers bytes create invoke destroy comment
1681	EV/EV 400000 224 0.47 0.35 0.27 EV native interface	2099	EV/EV 100000 223 0.47 0.43 0.27 EV native interface
1682	EV/Any 100000 224 2.88 0.34 0.27 EV + AnyEvent watchers	2100	EV/Any 100000 223 0.48 0.42 0.26 EV + AnyEvent watchers
1683	CoroEV/Any 100000 224 2.85 0.35 0.28 coroutines + Coro::Signal	2101	Coro::EV/Any 100000 223 0.47 0.42 0.26 coroutines + Coro::Signal
1684	Perl/Any 100000 452 4.13 0.73 0.95 pure perl implementation	2102	Perl/Any 100000 431 2.70 0.74 0.92 pure perl implementation
1685	Event/Event 16000 517 32.20 31.80 0.81 Event native interface	2103	Event/Event 16000 516 31.16 31.84 0.82 Event native interface
1686	Event/Any 16000 590 35.85 31.55 1.06 Event + AnyEvent watchers	2104	Event/Any 16000 1203 42.61 34.79 1.80 Event + AnyEvent watchers
		2105	IOAsync/Any 16000 1911 41.92 27.45 16.81 via IO::Async::Loop::IO_Poll
		2106	IOAsync/Any 16000 1726 40.69 26.37 15.25 via IO::Async::Loop::Epoll
1687	Glib/Any 16000 1357 102.33 12.31 51.00 quadratic behaviour	2107	Glib/Any 16000 1118 89.00 12.57 51.17 quadratic behaviour
1688	Tk/Any 2000 1860 27.20 66.31 14.00 SEGV with >> 2000 watchers	2108	Tk/Any 2000 1346 20.96 10.75 8.00 SEGV with >> 2000 watchers
1689	POE/Event 2000 6328 109.99 751.67 14.02 via POE::Loop::Event	2109	POE/Any 2000 6951 108.97 795.32 14.24 via POE::Loop::Event
1690	POE/Select 2000 6027 94.54 809.13 579.80 via POE::Loop::Select	2110	POE/Any 2000 6648 94.79 774.40 575.51 via POE::Loop::Select
1691		2111
1692	=head3 Discussion	2112	=head3 Discussion
1693		2113
1694	The benchmark does I<not> measure scalability of the event loop very	2114	The benchmark does I<not> measure scalability of the event loop very
1695	well. For example, a select-based event loop (such as the pure perl one)	2115	well. For example, a select-based event loop (such as the pure perl one)
…		…
1707	benchmark machine, handling an event takes roughly 1600 CPU cycles with	2127	benchmark machine, handling an event takes roughly 1600 CPU cycles with
1708	EV, 3100 CPU cycles with AnyEvent's pure perl loop and almost 3000000 CPU	2128	EV, 3100 CPU cycles with AnyEvent's pure perl loop and almost 3000000 CPU
1709	cycles with POE.	2129	cycles with POE.
1710		2130
1711	C<EV> is the sole leader regarding speed and memory use, which are both	2131	C<EV> is the sole leader regarding speed and memory use, which are both
1712	maximal/minimal, respectively. Even when going through AnyEvent, it uses	2132	maximal/minimal, respectively. When using the L<AE> API there is zero
		2133	overhead (when going through the AnyEvent API create is about 5-6 times
		2134	slower, with other times being equal, so still uses far less memory than
1713	far less memory than any other event loop and is still faster than Event	2135	any other event loop and is still faster than Event natively).
1714	natively.
1715		2136
1716	The pure perl implementation is hit in a few sweet spots (both the	2137	The pure perl implementation is hit in a few sweet spots (both the
1717	constant timeout and the use of a single fd hit optimisations in the perl	2138	constant timeout and the use of a single fd hit optimisations in the perl
1718	interpreter and the backend itself). Nevertheless this shows that it	2139	interpreter and the backend itself). Nevertheless this shows that it
1719	adds very little overhead in itself. Like any select-based backend its	2140	adds very little overhead in itself. Like any select-based backend its
1720	performance becomes really bad with lots of file descriptors (and few of	2141	performance becomes really bad with lots of file descriptors (and few of
1721	them active), of course, but this was not subject of this benchmark.	2142	them active), of course, but this was not subject of this benchmark.
1722		2143
1723	The C<Event> module has a relatively high setup and callback invocation	2144	The C<Event> module has a relatively high setup and callback invocation
1724	cost, but overall scores in on the third place.	2145	cost, but overall scores in on the third place.
		2146
		2147	C<IO::Async> performs admirably well, about on par with C<Event>, even
		2148	when using its pure perl backend.
1725		2149
1726	C<Glib>'s memory usage is quite a bit higher, but it features a	2150	C<Glib>'s memory usage is quite a bit higher, but it features a
1727	faster callback invocation and overall ends up in the same class as	2151	faster callback invocation and overall ends up in the same class as
1728	C<Event>. However, Glib scales extremely badly, doubling the number of	2152	C<Event>. However, Glib scales extremely badly, doubling the number of
1729	watchers increases the processing time by more than a factor of four,	2153	watchers increases the processing time by more than a factor of four,
…		…
1790	In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100	2214	In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100
1791	(1%) are active. This mirrors the activity of large servers with many	2215	(1%) are active. This mirrors the activity of large servers with many
1792	connections, most of which are idle at any one point in time.	2216	connections, most of which are idle at any one point in time.
1793		2217
1794	Source code for this benchmark is found as F<eg/bench2> in the AnyEvent	2218	Source code for this benchmark is found as F<eg/bench2> in the AnyEvent
1795	distribution.	2219	distribution. It uses the L<AE> interface, which makes a real difference
		2220	for the EV and Perl backends only.
1796		2221
1797	=head3 Explanation of the columns	2222	=head3 Explanation of the columns
1798		2223
1799	I<sockets> is the number of sockets, and twice the number of "servers" (as	2224	I<sockets> is the number of sockets, and twice the number of "servers" (as
1800	each server has a read and write socket end).	2225	each server has a read and write socket end).
…		…
1807	it to another server. This includes deleting the old timeout and creating	2232	it to another server. This includes deleting the old timeout and creating
1808	a new one that moves the timeout into the future.	2233	a new one that moves the timeout into the future.
1809		2234
1810	=head3 Results	2235	=head3 Results
1811		2236
1812	name sockets create request	2237	name sockets create request
1813	EV 20000 69.01 11.16	2238	EV 20000 62.66 7.99
1814	Perl 20000 73.32 35.87	2239	Perl 20000 68.32 32.64
1815	Event 20000 212.62 257.32	2240	IOAsync 20000 174.06 101.15 epoll
1816	Glib 20000 651.16 1896.30	2241	IOAsync 20000 174.67 610.84 poll
		2242	Event 20000 202.69 242.91
		2243	Glib 20000 557.01 1689.52
1817	POE 20000 349.67 12317.24 uses POE::Loop::Event	2244	POE 20000 341.54 12086.32 uses POE::Loop::Event
1818		2245
1819	=head3 Discussion	2246	=head3 Discussion
1820		2247
1821	This benchmark I<does> measure scalability and overall performance of the	2248	This benchmark I<does> measure scalability and overall performance of the
1822	particular event loop.	2249	particular event loop.
…		…
1824	EV is again fastest. Since it is using epoll on my system, the setup time	2251	EV is again fastest. Since it is using epoll on my system, the setup time
1825	is relatively high, though.	2252	is relatively high, though.
1826		2253
1827	Perl surprisingly comes second. It is much faster than the C-based event	2254	Perl surprisingly comes second. It is much faster than the C-based event
1828	loops Event and Glib.	2255	loops Event and Glib.
		2256
		2257	IO::Async performs very well when using its epoll backend, and still quite
		2258	good compared to Glib when using its pure perl backend.
1829		2259
1830	Event suffers from high setup time as well (look at its code and you will	2260	Event suffers from high setup time as well (look at its code and you will
1831	understand why). Callback invocation also has a high overhead compared to	2261	understand why). Callback invocation also has a high overhead compared to
1832	the C<< $_->() for .. >>-style loop that the Perl event loop uses. Event	2262	the C<< $_->() for .. >>-style loop that the Perl event loop uses. Event
1833	uses select or poll in basically all documented configurations.	2263	uses select or poll in basically all documented configurations.
…		…
1896	=item * C-based event loops perform very well with small number of	2326	=item * C-based event loops perform very well with small number of
1897	watchers, as the management overhead dominates.	2327	watchers, as the management overhead dominates.
1898		2328
1899	=back	2329	=back
1900		2330
		2331	=head2 THE IO::Lambda BENCHMARK
		2332
		2333	Recently I was told about the benchmark in the IO::Lambda manpage, which
		2334	could be misinterpreted to make AnyEvent look bad. In fact, the benchmark
		2335	simply compares IO::Lambda with POE, and IO::Lambda looks better (which
		2336	shouldn't come as a surprise to anybody). As such, the benchmark is
		2337	fine, and mostly shows that the AnyEvent backend from IO::Lambda isn't
		2338	very optimal. But how would AnyEvent compare when used without the extra
		2339	baggage? To explore this, I wrote the equivalent benchmark for AnyEvent.
		2340
		2341	The benchmark itself creates an echo-server, and then, for 500 times,
		2342	connects to the echo server, sends a line, waits for the reply, and then
		2343	creates the next connection. This is a rather bad benchmark, as it doesn't
		2344	test the efficiency of the framework or much non-blocking I/O, but it is a
		2345	benchmark nevertheless.
		2346
		2347	name runtime
		2348	Lambda/select 0.330 sec
		2349	+ optimized 0.122 sec
		2350	Lambda/AnyEvent 0.327 sec
		2351	+ optimized 0.138 sec
		2352	Raw sockets/select 0.077 sec
		2353	POE/select, components 0.662 sec
		2354	POE/select, raw sockets 0.226 sec
		2355	POE/select, optimized 0.404 sec
		2356
		2357	AnyEvent/select/nb 0.085 sec
		2358	AnyEvent/EV/nb 0.068 sec
		2359	+state machine 0.134 sec
		2360
		2361	The benchmark is also a bit unfair (my fault): the IO::Lambda/POE
		2362	benchmarks actually make blocking connects and use 100% blocking I/O,
		2363	defeating the purpose of an event-based solution. All of the newly
		2364	written AnyEvent benchmarks use 100% non-blocking connects (using
		2365	AnyEvent::Socket::tcp_connect and the asynchronous pure perl DNS
		2366	resolver), so AnyEvent is at a disadvantage here, as non-blocking connects
		2367	generally require a lot more bookkeeping and event handling than blocking
		2368	connects (which involve a single syscall only).
		2369
		2370	The last AnyEvent benchmark additionally uses L<AnyEvent::Handle>, which
		2371	offers similar expressive power as POE and IO::Lambda, using conventional
		2372	Perl syntax. This means that both the echo server and the client are 100%
		2373	non-blocking, further placing it at a disadvantage.
		2374
		2375	As you can see, the AnyEvent + EV combination even beats the
		2376	hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl
		2377	backend easily beats IO::Lambda and POE.
		2378
		2379	And even the 100% non-blocking version written using the high-level (and
		2380	slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda
		2381	higher level ("unoptimised") abstractions by a large margin, even though
		2382	it does all of DNS, tcp-connect and socket I/O in a non-blocking way.
		2383
		2384	The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and
		2385	F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are
		2386	part of the IO::Lambda distribution and were used without any changes.
		2387
1901		2388
1902	=head1 SIGNALS	2389	=head1 SIGNALS
1903		2390
1904	AnyEvent currently installs handlers for these signals:	2391	AnyEvent currently installs handlers for these signals:
1905		2392
…		…
1908	=item SIGCHLD	2395	=item SIGCHLD
1909		2396
1910	A handler for C<SIGCHLD> is installed by AnyEvent's child watcher	2397	A handler for C<SIGCHLD> is installed by AnyEvent's child watcher
1911	emulation for event loops that do not support them natively. Also, some	2398	emulation for event loops that do not support them natively. Also, some
1912	event loops install a similar handler.	2399	event loops install a similar handler.
		2400
		2401	Additionally, when AnyEvent is loaded and SIGCHLD is set to IGNORE, then
		2402	AnyEvent will reset it to default, to avoid losing child exit statuses.
1913		2403
1914	=item SIGPIPE	2404	=item SIGPIPE
1915		2405
1916	A no-op handler is installed for C<SIGPIPE> when C<$SIG{PIPE}> is C<undef>	2406	A no-op handler is installed for C<SIGPIPE> when C<$SIG{PIPE}> is C<undef>
1917	when AnyEvent gets loaded.	2407	when AnyEvent gets loaded.
…		…
1929		2419
1930	=back	2420	=back
1931		2421
1932	=cut	2422	=cut
1933		2423
		2424	undef $SIG{CHLD}
		2425	if $SIG{CHLD} eq 'IGNORE';
		2426
1934	$SIG{PIPE} = sub { }	2427	$SIG{PIPE} = sub { }
1935	unless defined $SIG{PIPE};	2428	unless defined $SIG{PIPE};
		2429
		2430	=head1 RECOMMENDED/OPTIONAL MODULES
		2431
		2432	One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and
		2433	it's built-in modules) are required to use it.
		2434
		2435	That does not mean that AnyEvent won't take advantage of some additional
		2436	modules if they are installed.
		2437
		2438	This section epxlains which additional modules will be used, and how they
		2439	affect AnyEvent's operetion.
		2440
		2441	=over 4
		2442
		2443	=item L<Async::Interrupt>
		2444
		2445	This slightly arcane module is used to implement fast signal handling: To
		2446	my knowledge, there is no way to do completely race-free and quick
		2447	signal handling in pure perl. To ensure that signals still get
		2448	delivered, AnyEvent will start an interval timer to wake up perl (and
		2449	catch the signals) with some delay (default is 10 seconds, look for
		2450	C<$AnyEvent::MAX_SIGNAL_LATENCY>).
		2451
		2452	If this module is available, then it will be used to implement signal
		2453	catching, which means that signals will not be delayed, and the event loop
		2454	will not be interrupted regularly, which is more efficient (And good for
		2455	battery life on laptops).
		2456
		2457	This affects not just the pure-perl event loop, but also other event loops
		2458	that have no signal handling on their own (e.g. Glib, Tk, Qt).
		2459
		2460	Some event loops (POE, Event, Event::Lib) offer signal watchers natively,
		2461	and either employ their own workarounds (POE) or use AnyEvent's workaround
		2462	(using C<$AnyEvent::MAX_SIGNAL_LATENCY>). Installing L<Async::Interrupt>
		2463	does nothing for those backends.
		2464
		2465	=item L<EV>
		2466
		2467	This module isn't really "optional", as it is simply one of the backend
		2468	event loops that AnyEvent can use. However, it is simply the best event
		2469	loop available in terms of features, speed and stability: It supports
		2470	the AnyEvent API optimally, implements all the watcher types in XS, does
		2471	automatic timer adjustments even when no monotonic clock is available,
		2472	can take avdantage of advanced kernel interfaces such as C<epoll> and
		2473	C<kqueue>, and is the fastest backend I<by far>. You can even embed
		2474	L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>).
		2475
		2476	=item L<Guard>
		2477
		2478	The guard module, when used, will be used to implement
		2479	C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a
		2480	lot less memory), but otherwise doesn't affect guard operation much. It is
		2481	purely used for performance.
		2482
		2483	=item L<JSON> and L<JSON::XS>
		2484
		2485	One of these modules is required when you want to read or write JSON data
		2486	via L<AnyEvent::Handle>. It is also written in pure-perl, but can take
		2487	advantage of the ultra-high-speed L<JSON::XS> module when it is installed.
		2488
		2489	In fact, L<AnyEvent::Handle> will use L<JSON::XS> by default if it is
		2490	installed.
		2491
		2492	=item L<Net::SSLeay>
		2493
		2494	Implementing TLS/SSL in Perl is certainly interesting, but not very
		2495	worthwhile: If this module is installed, then L<AnyEvent::Handle> (with
		2496	the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL.
		2497
		2498	=item L<Time::HiRes>
		2499
		2500	This module is part of perl since release 5.008. It will be used when the
		2501	chosen event library does not come with a timing source on it's own. The
		2502	pure-perl event loop (L<AnyEvent::Impl::Perl>) will additionally use it to
		2503	try to use a monotonic clock for timing stability.
		2504
		2505	=back
1936		2506
1937		2507
1938	=head1 FORK	2508	=head1 FORK
1939		2509
1940	Most event libraries are not fork-safe. The ones who are usually are	2510	Most event libraries are not fork-safe. The ones who are usually are
1941	because they rely on inefficient but fork-safe C<select> or C<poll>	2511	because they rely on inefficient but fork-safe C<select> or C<poll>
1942	calls. Only L<EV> is fully fork-aware.	2512	calls. Only L<EV> is fully fork-aware.
1943		2513
1944	If you have to fork, you must either do so I<before> creating your first	2514	If you have to fork, you must either do so I<before> creating your first
1945	watcher OR you must not use AnyEvent at all in the child.	2515	watcher OR you must not use AnyEvent at all in the child OR you must do
		2516	something completely out of the scope of AnyEvent.
1946		2517
1947		2518
1948	=head1 SECURITY CONSIDERATIONS	2519	=head1 SECURITY CONSIDERATIONS
1949		2520
1950	AnyEvent can be forced to load any event model via	2521	AnyEvent can be forced to load any event model via
…		…
1962	use AnyEvent;	2533	use AnyEvent;
1963		2534
1964	Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can	2535	Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can
1965	be used to probe what backend is used and gain other information (which is	2536	be used to probe what backend is used and gain other information (which is
1966	probably even less useful to an attacker than PERL_ANYEVENT_MODEL), and	2537	probably even less useful to an attacker than PERL_ANYEVENT_MODEL), and
1967	$ENV{PERL_ANYEGENT_STRICT}.	2538	$ENV{PERL_ANYEVENT_STRICT}.
		2539
		2540	Note that AnyEvent will remove I<all> environment variables starting with
		2541	C<PERL_ANYEVENT_> from C<%ENV> when it is loaded while taint mode is
		2542	enabled.
1968		2543
1969		2544
1970	=head1 BUGS	2545	=head1 BUGS
1971		2546
1972	Perl 5.8 has numerous memleaks that sometimes hit this module and are hard	2547	Perl 5.8 has numerous memleaks that sometimes hit this module and are hard
…		…
1984	L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.	2559	L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.
1985		2560
1986	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,	2561	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,
1987	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,	2562	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,
1988	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,	2563	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,
1989	L<AnyEvent::Impl::POE>.	2564	L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>, L<Anyevent::Impl::Irssi>.
1990		2565
1991	Non-blocking file handles, sockets, TCP clients and	2566	Non-blocking file handles, sockets, TCP clients and
1992	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>.	2567	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.
1993		2568
1994	Asynchronous DNS: L<AnyEvent::DNS>.	2569	Asynchronous DNS: L<AnyEvent::DNS>.
1995		2570
1996	Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>,	2571	Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>,
		2572	L<Coro::Event>,
1997		2573
1998	Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>, L<AnyEvent::DNS>.	2574	Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::XMPP>,
		2575	L<AnyEvent::HTTP>.
1999		2576
2000		2577
2001	=head1 AUTHOR	2578	=head1 AUTHOR
2002		2579
2003	Marc Lehmann <schmorp@schmorp.de>	2580	Marc Lehmann <schmorp@schmorp.de>

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