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Revision 1.232 by root, Thu Jul 9 01:08:22 2009 UTC vs.
Revision 1.320 by root, Mon Apr 12 02:50:31 2010 UTC

1	=head1 NAME	1	=head1 NAME
2		2
3	AnyEvent - provide framework for multiple event loops	3	AnyEvent - the DBI of event loop programming
4		4
5	EV, Event, Glib, Tk, Perl, Event::Lib, Qt and POE are various supported	5	EV, Event, Glib, Tk, Perl, Event::Lib, Irssi, rxvt-unicode, IO::Async, Qt
6	event loops.	6	and POE are various supported event loops/environments.
7		7
8	=head1 SYNOPSIS	8	=head1 SYNOPSIS
9		9
10	use AnyEvent;	10	use AnyEvent;
11		11
		12	# if you prefer function calls, look at the L<AE> manpage for
		13	# an alternative API.
		14
12	# file descriptor readable	15	# file handle or descriptor readable
13	my $w = AnyEvent->io (fh => $fh, poll => "r", cb => sub { ... });	16	my $w = AnyEvent->io (fh => $fh, poll => "r", cb => sub { ... });
14		17
15	# one-shot or repeating timers	18	# one-shot or repeating timers
16	my $w = AnyEvent->timer (after => $seconds, cb => sub { ... });	19	my $w = AnyEvent->timer (after => $seconds, cb => sub { ... });
17	my $w = AnyEvent->timer (after => $seconds, interval => $seconds, cb => ...	20	my $w = AnyEvent->timer (after => $seconds, interval => $seconds, cb => ...
…		…
40	=head1 INTRODUCTION/TUTORIAL	43	=head1 INTRODUCTION/TUTORIAL
41		44
42	This manpage is mainly a reference manual. If you are interested	45	This manpage is mainly a reference manual. If you are interested
43	in a tutorial or some gentle introduction, have a look at the	46	in a tutorial or some gentle introduction, have a look at the
44	L<AnyEvent::Intro> manpage.	47	L<AnyEvent::Intro> manpage.
		48
		49	=head1 SUPPORT
		50
		51	There is a mailinglist for discussing all things AnyEvent, and an IRC
		52	channel, too.
		53
		54	See the AnyEvent project page at the B<Schmorpforge Ta-Sa Software
		55	Repository>, at L<http://anyevent.schmorp.de>, for more info.
45		56
46	=head1 WHY YOU SHOULD USE THIS MODULE (OR NOT)	57	=head1 WHY YOU SHOULD USE THIS MODULE (OR NOT)
47		58
48	Glib, POE, IO::Async, Event... CPAN offers event models by the dozen	59	Glib, POE, IO::Async, Event... CPAN offers event models by the dozen
49	nowadays. So what is different about AnyEvent?	60	nowadays. So what is different about AnyEvent?
…		…
173	my variables are only visible after the statement in which they are	184	my variables are only visible after the statement in which they are
174	declared.	185	declared.
175		186
176	=head2 I/O WATCHERS	187	=head2 I/O WATCHERS
177		188
		189	$w = AnyEvent->io (
		190	fh => <filehandle_or_fileno>,
		191	poll => <"r" or "w">,
		192	cb => <callback>,
		193	);
		194
178	You can create an I/O watcher by calling the C<< AnyEvent->io >> method	195	You can create an I/O watcher by calling the C<< AnyEvent->io >> method
179	with the following mandatory key-value pairs as arguments:	196	with the following mandatory key-value pairs as arguments:
180		197
181	C<fh> is the Perl I<file handle> (or a naked file descriptor) to watch	198	C<fh> is the Perl I<file handle> (or a naked file descriptor) to watch
182	for events (AnyEvent might or might not keep a reference to this file	199	for events (AnyEvent might or might not keep a reference to this file
…		…
211	undef $w;	228	undef $w;
212	});	229	});
213		230
214	=head2 TIME WATCHERS	231	=head2 TIME WATCHERS
215		232
		233	$w = AnyEvent->timer (after => <seconds>, cb => <callback>);
		234
		235	$w = AnyEvent->timer (
		236	after => <fractional_seconds>,
		237	interval => <fractional_seconds>,
		238	cb => <callback>,
		239	);
		240
216	You can create a time watcher by calling the C<< AnyEvent->timer >>	241	You can create a time watcher by calling the C<< AnyEvent->timer >>
217	method with the following mandatory arguments:	242	method with the following mandatory arguments:
218		243
219	C<after> specifies after how many seconds (fractional values are	244	C<after> specifies after how many seconds (fractional values are
220	supported) the callback should be invoked. C<cb> is the callback to invoke	245	supported) the callback should be invoked. C<cb> is the callback to invoke
…		…
341	might affect timers and time-outs.	366	might affect timers and time-outs.
342		367
343	When this is the case, you can call this method, which will update the	368	When this is the case, you can call this method, which will update the
344	event loop's idea of "current time".	369	event loop's idea of "current time".
345		370
		371	A typical example would be a script in a web server (e.g. C<mod_perl>) -
		372	when mod_perl executes the script, then the event loop will have the wrong
		373	idea about the "current time" (being potentially far in the past, when the
		374	script ran the last time). In that case you should arrange a call to C<<
		375	AnyEvent->now_update >> each time the web server process wakes up again
		376	(e.g. at the start of your script, or in a handler).
		377
346	Note that updating the time I<might> cause some events to be handled.	378	Note that updating the time I<might> cause some events to be handled.
347		379
348	=back	380	=back
349		381
350	=head2 SIGNAL WATCHERS	382	=head2 SIGNAL WATCHERS
		383
		384	$w = AnyEvent->signal (signal => <uppercase_signal_name>, cb => <callback>);
351		385
352	You can watch for signals using a signal watcher, C<signal> is the signal	386	You can watch for signals using a signal watcher, C<signal> is the signal
353	I<name> in uppercase and without any C<SIG> prefix, C<cb> is the Perl	387	I<name> in uppercase and without any C<SIG> prefix, C<cb> is the Perl
354	callback to be invoked whenever a signal occurs.	388	callback to be invoked whenever a signal occurs.
355		389
…		…
361	invocation, and callback invocation will be synchronous. Synchronous means	395	invocation, and callback invocation will be synchronous. Synchronous means
362	that it might take a while until the signal gets handled by the process,	396	that it might take a while until the signal gets handled by the process,
363	but it is guaranteed not to interrupt any other callbacks.	397	but it is guaranteed not to interrupt any other callbacks.
364		398
365	The main advantage of using these watchers is that you can share a signal	399	The main advantage of using these watchers is that you can share a signal
366	between multiple watchers.	400	between multiple watchers, and AnyEvent will ensure that signals will not
		401	interrupt your program at bad times.
367		402
368	This watcher might use C<%SIG>, so programs overwriting those signals	403	This watcher might use C<%SIG> (depending on the event loop used),
369	directly will likely not work correctly.	404	so programs overwriting those signals directly will likely not work
		405	correctly.
370		406
371	Example: exit on SIGINT	407	Example: exit on SIGINT
372		408
373	my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });	409	my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });
374		410
		411	=head3 Restart Behaviour
		412
		413	While restart behaviour is up to the event loop implementation, most will
		414	not restart syscalls (that includes L<Async::Interrupt> and AnyEvent's
		415	pure perl implementation).
		416
		417	=head3 Safe/Unsafe Signals
		418
		419	Perl signals can be either "safe" (synchronous to opcode handling) or
		420	"unsafe" (asynchronous) - the former might get delayed indefinitely, the
		421	latter might corrupt your memory.
		422
		423	AnyEvent signal handlers are, in addition, synchronous to the event loop,
		424	i.e. they will not interrupt your running perl program but will only be
		425	called as part of the normal event handling (just like timer, I/O etc.
		426	callbacks, too).
		427
		428	=head3 Signal Races, Delays and Workarounds
		429
		430	Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support attaching
		431	callbacks to signals in a generic way, which is a pity, as you cannot
		432	do race-free signal handling in perl, requiring C libraries for
		433	this. AnyEvent will try to do it's best, which means in some cases,
		434	signals will be delayed. The maximum time a signal might be delayed is
		435	specified in C<$AnyEvent::MAX_SIGNAL_LATENCY> (default: 10 seconds). This
		436	variable can be changed only before the first signal watcher is created,
		437	and should be left alone otherwise. This variable determines how often
		438	AnyEvent polls for signals (in case a wake-up was missed). Higher values
		439	will cause fewer spurious wake-ups, which is better for power and CPU
		440	saving.
		441
		442	All these problems can be avoided by installing the optional
		443	L<Async::Interrupt> module, which works with most event loops. It will not
		444	work with inherently broken event loops such as L<Event> or L<Event::Lib>
		445	(and not with L<POE> currently, as POE does it's own workaround with
		446	one-second latency). For those, you just have to suffer the delays.
		447
375	=head2 CHILD PROCESS WATCHERS	448	=head2 CHILD PROCESS WATCHERS
376		449
		450	$w = AnyEvent->child (pid => <process id>, cb => <callback>);
		451
377	You can also watch on a child process exit and catch its exit status.	452	You can also watch on a child process exit and catch its exit status.
378		453
379	The child process is specified by the C<pid> argument (if set to C<0>, it	454	The child process is specified by the C<pid> argument (one some backends,
380	watches for any child process exit). The watcher will triggered only when	455	using C<0> watches for any child process exit, on others this will
381	the child process has finished and an exit status is available, not on	456	croak). The watcher will be triggered only when the child process has
382	any trace events (stopped/continued).	457	finished and an exit status is available, not on any trace events
		458	(stopped/continued).
383		459
384	The callback will be called with the pid and exit status (as returned by	460	The callback will be called with the pid and exit status (as returned by
385	waitpid), so unlike other watcher types, you I<can> rely on child watcher	461	waitpid), so unlike other watcher types, you I<can> rely on child watcher
386	callback arguments.	462	callback arguments.
387		463
…		…
403		479
404	This means you cannot create a child watcher as the very first	480	This means you cannot create a child watcher as the very first
405	thing in an AnyEvent program, you I<have> to create at least one	481	thing in an AnyEvent program, you I<have> to create at least one
406	watcher before you C<fork> the child (alternatively, you can call	482	watcher before you C<fork> the child (alternatively, you can call
407	C<AnyEvent::detect>).	483	C<AnyEvent::detect>).
		484
		485	As most event loops do not support waiting for child events, they will be
		486	emulated by AnyEvent in most cases, in which the latency and race problems
		487	mentioned in the description of signal watchers apply.
408		488
409	Example: fork a process and wait for it	489	Example: fork a process and wait for it
410		490
411	my $done = AnyEvent->condvar;	491	my $done = AnyEvent->condvar;
412		492
…		…
424	# do something else, then wait for process exit	504	# do something else, then wait for process exit
425	$done->recv;	505	$done->recv;
426		506
427	=head2 IDLE WATCHERS	507	=head2 IDLE WATCHERS
428		508
429	Sometimes there is a need to do something, but it is not so important	509	$w = AnyEvent->idle (cb => <callback>);
430	to do it instantly, but only when there is nothing better to do. This
431	"nothing better to do" is usually defined to be "no other events need
432	attention by the event loop".
433		510
434	Idle watchers ideally get invoked when the event loop has nothing	511	Repeatedly invoke the callback after the process becomes idle, until
435	better to do, just before it would block the process to wait for new	512	either the watcher is destroyed or new events have been detected.
436	events. Instead of blocking, the idle watcher is invoked.
437		513
438	Most event loops unfortunately do not really support idle watchers (only	514	Idle watchers are useful when there is a need to do something, but it
		515	is not so important (or wise) to do it instantly. The callback will be
		516	invoked only when there is "nothing better to do", which is usually
		517	defined as "all outstanding events have been handled and no new events
		518	have been detected". That means that idle watchers ideally get invoked
		519	when the event loop has just polled for new events but none have been
		520	detected. Instead of blocking to wait for more events, the idle watchers
		521	will be invoked.
		522
		523	Unfortunately, most event loops do not really support idle watchers (only
439	EV, Event and Glib do it in a usable fashion) - for the rest, AnyEvent	524	EV, Event and Glib do it in a usable fashion) - for the rest, AnyEvent
440	will simply call the callback "from time to time".	525	will simply call the callback "from time to time".
441		526
442	Example: read lines from STDIN, but only process them when the	527	Example: read lines from STDIN, but only process them when the
443	program is otherwise idle:	528	program is otherwise idle:
…		…
459	});	544	});
460	});	545	});
461		546
462	=head2 CONDITION VARIABLES	547	=head2 CONDITION VARIABLES
463		548
		549	$cv = AnyEvent->condvar;
		550
		551	$cv->send (<list>);
		552	my @res = $cv->recv;
		553
464	If you are familiar with some event loops you will know that all of them	554	If you are familiar with some event loops you will know that all of them
465	require you to run some blocking "loop", "run" or similar function that	555	require you to run some blocking "loop", "run" or similar function that
466	will actively watch for new events and call your callbacks.	556	will actively watch for new events and call your callbacks.
467		557
468	AnyEvent is different, it expects somebody else to run the event loop and	558	AnyEvent is slightly different: it expects somebody else to run the event
469	will only block when necessary (usually when told by the user).	559	loop and will only block when necessary (usually when told by the user).
470		560
471	The instrument to do that is called a "condition variable", so called	561	The instrument to do that is called a "condition variable", so called
472	because they represent a condition that must become true.	562	because they represent a condition that must become true.
473		563
		564	Now is probably a good time to look at the examples further below.
		565
474	Condition variables can be created by calling the C<< AnyEvent->condvar	566	Condition variables can be created by calling the C<< AnyEvent->condvar
475	>> method, usually without arguments. The only argument pair allowed is	567	>> method, usually without arguments. The only argument pair allowed is
476
477	C<cb>, which specifies a callback to be called when the condition variable	568	C<cb>, which specifies a callback to be called when the condition variable
478	becomes true, with the condition variable as the first argument (but not	569	becomes true, with the condition variable as the first argument (but not
479	the results).	570	the results).
480		571
481	After creation, the condition variable is "false" until it becomes "true"	572	After creation, the condition variable is "false" until it becomes "true"
…		…
486	Condition variables are similar to callbacks, except that you can	577	Condition variables are similar to callbacks, except that you can
487	optionally wait for them. They can also be called merge points - points	578	optionally wait for them. They can also be called merge points - points
488	in time where multiple outstanding events have been processed. And yet	579	in time where multiple outstanding events have been processed. And yet
489	another way to call them is transactions - each condition variable can be	580	another way to call them is transactions - each condition variable can be
490	used to represent a transaction, which finishes at some point and delivers	581	used to represent a transaction, which finishes at some point and delivers
491	a result.	582	a result. And yet some people know them as "futures" - a promise to
		583	compute/deliver something that you can wait for.
492		584
493	Condition variables are very useful to signal that something has finished,	585	Condition variables are very useful to signal that something has finished,
494	for example, if you write a module that does asynchronous http requests,	586	for example, if you write a module that does asynchronous http requests,
495	then a condition variable would be the ideal candidate to signal the	587	then a condition variable would be the ideal candidate to signal the
496	availability of results. The user can either act when the callback is	588	availability of results. The user can either act when the callback is
…		…
517	eventually calls C<< -> send >>, and the "consumer side", which waits	609	eventually calls C<< -> send >>, and the "consumer side", which waits
518	for the send to occur.	610	for the send to occur.
519		611
520	Example: wait for a timer.	612	Example: wait for a timer.
521		613
522	# wait till the result is ready	614	# condition: "wait till the timer is fired"
523	my $result_ready = AnyEvent->condvar;	615	my $timer_fired = AnyEvent->condvar;
524		616
525	# do something such as adding a timer	617	# create the timer - we could wait for, say
526	# or socket watcher the calls $result_ready->send	618	# a handle becomign ready, or even an
527	# when the "result" is ready.	619	# AnyEvent::HTTP request to finish, but
528	# in this case, we simply use a timer:	620	# in this case, we simply use a timer:
529	my $w = AnyEvent->timer (	621	my $w = AnyEvent->timer (
530	after => 1,	622	after => 1,
531	cb => sub { $result_ready->send },	623	cb => sub { $timer_fired->send },
532	);	624	);
533		625
534	# this "blocks" (while handling events) till the callback	626	# this "blocks" (while handling events) till the callback
535	# calls send	627	# calls ->send
536	$result_ready->recv;	628	$timer_fired->recv;
537		629
538	Example: wait for a timer, but take advantage of the fact that	630	Example: wait for a timer, but take advantage of the fact that condition
539	condition variables are also code references.	631	variables are also callable directly.
540		632
541	my $done = AnyEvent->condvar;	633	my $done = AnyEvent->condvar;
542	my $delay = AnyEvent->timer (after => 5, cb => $done);	634	my $delay = AnyEvent->timer (after => 5, cb => $done);
543	$done->recv;	635	$done->recv;
544		636
…		…
550		642
551	...	643	...
552		644
553	my @info = $couchdb->info->recv;	645	my @info = $couchdb->info->recv;
554		646
555	And this is how you would just ste a callback to be called whenever the	647	And this is how you would just set a callback to be called whenever the
556	results are available:	648	results are available:
557		649
558	$couchdb->info->cb (sub {	650	$couchdb->info->cb (sub {
559	my @info = $_[0]->recv;	651	my @info = $_[0]->recv;
560	});	652	});
…		…
578	immediately from within send.	670	immediately from within send.
579		671
580	Any arguments passed to the C<send> call will be returned by all	672	Any arguments passed to the C<send> call will be returned by all
581	future C<< ->recv >> calls.	673	future C<< ->recv >> calls.
582		674
583	Condition variables are overloaded so one can call them directly	675	Condition variables are overloaded so one can call them directly (as if
584	(as a code reference). Calling them directly is the same as calling	676	they were a code reference). Calling them directly is the same as calling
585	C<send>. Note, however, that many C-based event loops do not handle	677	C<send>.
586	overloading, so as tempting as it may be, passing a condition variable
587	instead of a callback does not work. Both the pure perl and EV loops
588	support overloading, however, as well as all functions that use perl to
589	invoke a callback (as in L<AnyEvent::Socket> and L<AnyEvent::DNS> for
590	example).
591		678
592	=item $cv->croak ($error)	679	=item $cv->croak ($error)
593		680
594	Similar to send, but causes all call's to C<< ->recv >> to invoke	681	Similar to send, but causes all call's to C<< ->recv >> to invoke
595	C<Carp::croak> with the given error message/object/scalar.	682	C<Carp::croak> with the given error message/object/scalar.
596		683
597	This can be used to signal any errors to the condition variable	684	This can be used to signal any errors to the condition variable
598	user/consumer.	685	user/consumer. Doing it this way instead of calling C<croak> directly
		686	delays the error detetcion, but has the overwhelmign advantage that it
		687	diagnoses the error at the place where the result is expected, and not
		688	deep in some event clalback without connection to the actual code causing
		689	the problem.
599		690
600	=item $cv->begin ([group callback])	691	=item $cv->begin ([group callback])
601		692
602	=item $cv->end	693	=item $cv->end
603		694
…		…
605	one. For example, a function that pings many hosts in parallel might want	696	one. For example, a function that pings many hosts in parallel might want
606	to use a condition variable for the whole process.	697	to use a condition variable for the whole process.
607		698
608	Every call to C<< ->begin >> will increment a counter, and every call to	699	Every call to C<< ->begin >> will increment a counter, and every call to
609	C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end	700	C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end
610	>>, the (last) callback passed to C<begin> will be executed. That callback	701	>>, the (last) callback passed to C<begin> will be executed, passing the
611	is I<supposed> to call C<< ->send >>, but that is not required. If no	702	condvar as first argument. That callback is I<supposed> to call C<< ->send
612	callback was set, C<send> will be called without any arguments.	703	>>, but that is not required. If no group callback was set, C<send> will
		704	be called without any arguments.
613		705
614	You can think of C<< $cv->send >> giving you an OR condition (one call	706	You can think of C<< $cv->send >> giving you an OR condition (one call
615	sends), while C<< $cv->begin >> and C<< $cv->end >> giving you an AND	707	sends), while C<< $cv->begin >> and C<< $cv->end >> giving you an AND
616	condition (all C<begin> calls must be C<end>'ed before the condvar sends).	708	condition (all C<begin> calls must be C<end>'ed before the condvar sends).
617		709
…		…
644	begung can potentially be zero:	736	begung can potentially be zero:
645		737
646	my $cv = AnyEvent->condvar;	738	my $cv = AnyEvent->condvar;
647		739
648	my %result;	740	my %result;
649	$cv->begin (sub { $cv->send (\%result) });	741	$cv->begin (sub { shift->send (\%result) });
650		742
651	for my $host (@list_of_hosts) {	743	for my $host (@list_of_hosts) {
652	$cv->begin;	744	$cv->begin;
653	ping_host_then_call_callback $host, sub {	745	ping_host_then_call_callback $host, sub {
654	$result{$host} = ...;	746	$result{$host} = ...;
…		…
699	function will call C<croak>.	791	function will call C<croak>.
700		792
701	In list context, all parameters passed to C<send> will be returned,	793	In list context, all parameters passed to C<send> will be returned,
702	in scalar context only the first one will be returned.	794	in scalar context only the first one will be returned.
703		795
		796	Note that doing a blocking wait in a callback is not supported by any
		797	event loop, that is, recursive invocation of a blocking C<< ->recv
		798	>> is not allowed, and the C<recv> call will C<croak> if such a
		799	condition is detected. This condition can be slightly loosened by using
		800	L<Coro::AnyEvent>, which allows you to do a blocking C<< ->recv >> from
		801	any thread that doesn't run the event loop itself.
		802
704	Not all event models support a blocking wait - some die in that case	803	Not all event models support a blocking wait - some die in that case
705	(programs might want to do that to stay interactive), so I<if you are	804	(programs might want to do that to stay interactive), so I<if you are
706	using this from a module, never require a blocking wait>, but let the	805	using this from a module, never require a blocking wait>. Instead, let the
707	caller decide whether the call will block or not (for example, by coupling	806	caller decide whether the call will block or not (for example, by coupling
708	condition variables with some kind of request results and supporting	807	condition variables with some kind of request results and supporting
709	callbacks so the caller knows that getting the result will not block,	808	callbacks so the caller knows that getting the result will not block,
710	while still supporting blocking waits if the caller so desires).	809	while still supporting blocking waits if the caller so desires).
711		810
712	Another reason I<never> to C<< ->recv >> in a module is that you cannot
713	sensibly have two C<< ->recv >>'s in parallel, as that would require
714	multiple interpreters or coroutines/threads, none of which C<AnyEvent>
715	can supply.
716
717	The L<Coro> module, however, I<can> and I<does> supply coroutines and, in
718	fact, L<Coro::AnyEvent> replaces AnyEvent's condvars by coroutine-safe
719	versions and also integrates coroutines into AnyEvent, making blocking
720	C<< ->recv >> calls perfectly safe as long as they are done from another
721	coroutine (one that doesn't run the event loop).
722
723	You can ensure that C<< -recv >> never blocks by setting a callback and	811	You can ensure that C<< -recv >> never blocks by setting a callback and
724	only calling C<< ->recv >> from within that callback (or at a later	812	only calling C<< ->recv >> from within that callback (or at a later
725	time). This will work even when the event loop does not support blocking	813	time). This will work even when the event loop does not support blocking
726	waits otherwise.	814	waits otherwise.
727		815
…		…
733	=item $cb = $cv->cb ($cb->($cv))	821	=item $cb = $cv->cb ($cb->($cv))
734		822
735	This is a mutator function that returns the callback set and optionally	823	This is a mutator function that returns the callback set and optionally
736	replaces it before doing so.	824	replaces it before doing so.
737		825
738	The callback will be called when the condition becomes "true", i.e. when	826	The callback will be called when the condition becomes (or already was)
739	C<send> or C<croak> are called, with the only argument being the condition	827	"true", i.e. when C<send> or C<croak> are called (or were called), with
740	variable itself. Calling C<recv> inside the callback or at any later time	828	the only argument being the condition variable itself. Calling C<recv>
741	is guaranteed not to block.	829	inside the callback or at any later time is guaranteed not to block.
742		830
743	=back	831	=back
744		832
745	=head1 SUPPORTED EVENT LOOPS/BACKENDS	833	=head1 SUPPORTED EVENT LOOPS/BACKENDS
746		834
…		…
749	=over 4	837	=over 4
750		838
751	=item Backends that are autoprobed when no other event loop can be found.	839	=item Backends that are autoprobed when no other event loop can be found.
752		840
753	EV is the preferred backend when no other event loop seems to be in	841	EV is the preferred backend when no other event loop seems to be in
754	use. If EV is not installed, then AnyEvent will try Event, and, failing	842	use. If EV is not installed, then AnyEvent will fall back to its own
755	that, will fall back to its own pure-perl implementation, which is	843	pure-perl implementation, which is available everywhere as it comes with
756	available everywhere as it comes with AnyEvent itself.	844	AnyEvent itself.
757		845
758	AnyEvent::Impl::EV based on EV (interface to libev, best choice).	846	AnyEvent::Impl::EV based on EV (interface to libev, best choice).
759	AnyEvent::Impl::Event based on Event, very stable, few glitches.
760	AnyEvent::Impl::Perl pure-perl implementation, fast and portable.	847	AnyEvent::Impl::Perl pure-perl implementation, fast and portable.
761		848
762	=item Backends that are transparently being picked up when they are used.	849	=item Backends that are transparently being picked up when they are used.
763		850
764	These will be used when they are currently loaded when the first watcher	851	These will be used when they are currently loaded when the first watcher
765	is created, in which case it is assumed that the application is using	852	is created, in which case it is assumed that the application is using
766	them. This means that AnyEvent will automatically pick the right backend	853	them. This means that AnyEvent will automatically pick the right backend
767	when the main program loads an event module before anything starts to	854	when the main program loads an event module before anything starts to
768	create watchers. Nothing special needs to be done by the main program.	855	create watchers. Nothing special needs to be done by the main program.
769		856
		857	AnyEvent::Impl::Event based on Event, very stable, few glitches.
770	AnyEvent::Impl::Glib based on Glib, slow but very stable.	858	AnyEvent::Impl::Glib based on Glib, slow but very stable.
771	AnyEvent::Impl::Tk based on Tk, very broken.	859	AnyEvent::Impl::Tk based on Tk, very broken.
772	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.	860	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
773	AnyEvent::Impl::POE based on POE, very slow, some limitations.	861	AnyEvent::Impl::POE based on POE, very slow, some limitations.
		862	AnyEvent::Impl::Irssi used when running within irssi.
774		863
775	=item Backends with special needs.	864	=item Backends with special needs.
776		865
777	Qt requires the Qt::Application to be instantiated first, but will	866	Qt requires the Qt::Application to be instantiated first, but will
778	otherwise be picked up automatically. As long as the main program	867	otherwise be picked up automatically. As long as the main program
…		…
809		898
810	=back	899	=back
811		900
812	=head1 GLOBAL VARIABLES AND FUNCTIONS	901	=head1 GLOBAL VARIABLES AND FUNCTIONS
813		902
		903	These are not normally required to use AnyEvent, but can be useful to
		904	write AnyEvent extension modules.
		905
814	=over 4	906	=over 4
815		907
816	=item $AnyEvent::MODEL	908	=item $AnyEvent::MODEL
817		909
818	Contains C<undef> until the first watcher is being created. Then it	910	Contains C<undef> until the first watcher is being created, before the
		911	backend has been autodetected.
		912
819	contains the event model that is being used, which is the name of the	913	Afterwards it contains the event model that is being used, which is the
820	Perl class implementing the model. This class is usually one of the	914	name of the Perl class implementing the model. This class is usually one
821	C<AnyEvent::Impl:xxx> modules, but can be any other class in the case	915	of the C<AnyEvent::Impl:xxx> modules, but can be any other class in the
822	AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode>).	916	case AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode> it
		917	will be C<urxvt::anyevent>).
823		918
824	=item AnyEvent::detect	919	=item AnyEvent::detect
825		920
826	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model	921	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model
827	if necessary. You should only call this function right before you would	922	if necessary. You should only call this function right before you would
828	have created an AnyEvent watcher anyway, that is, as late as possible at	923	have created an AnyEvent watcher anyway, that is, as late as possible at
829	runtime.	924	runtime, and not e.g. while initialising of your module.
		925
		926	If you need to do some initialisation before AnyEvent watchers are
		927	created, use C<post_detect>.
830		928
831	=item $guard = AnyEvent::post_detect { BLOCK }	929	=item $guard = AnyEvent::post_detect { BLOCK }
832		930
833	Arranges for the code block to be executed as soon as the event model is	931	Arranges for the code block to be executed as soon as the event model is
834	autodetected (or immediately if this has already happened).	932	autodetected (or immediately if this has already happened).
835		933
		934	The block will be executed I<after> the actual backend has been detected
		935	(C<$AnyEvent::MODEL> is set), but I<before> any watchers have been
		936	created, so it is possible to e.g. patch C<@AnyEvent::ISA> or do
		937	other initialisations - see the sources of L<AnyEvent::Strict> or
		938	L<AnyEvent::AIO> to see how this is used.
		939
		940	The most common usage is to create some global watchers, without forcing
		941	event module detection too early, for example, L<AnyEvent::AIO> creates
		942	and installs the global L<IO::AIO> watcher in a C<post_detect> block to
		943	avoid autodetecting the event module at load time.
		944
836	If called in scalar or list context, then it creates and returns an object	945	If called in scalar or list context, then it creates and returns an object
837	that automatically removes the callback again when it is destroyed. See	946	that automatically removes the callback again when it is destroyed (or
		947	C<undef> when the hook was immediately executed). See L<AnyEvent::AIO> for
838	L<Coro::BDB> for a case where this is useful.	948	a case where this is useful.
		949
		950	Example: Create a watcher for the IO::AIO module and store it in
		951	C<$WATCHER>. Only do so after the event loop is initialised, though.
		952
		953	our WATCHER;
		954
		955	my $guard = AnyEvent::post_detect {
		956	$WATCHER = AnyEvent->io (fh => IO::AIO::poll_fileno, poll => 'r', cb => \&IO::AIO::poll_cb);
		957	};
		958
		959	# the ||= is important in case post_detect immediately runs the block,
		960	# as to not clobber the newly-created watcher. assigning both watcher and
		961	# post_detect guard to the same variable has the advantage of users being
		962	# able to just C<undef $WATCHER> if the watcher causes them grief.
		963
		964	$WATCHER ||= $guard;
839		965
840	=item @AnyEvent::post_detect	966	=item @AnyEvent::post_detect
841		967
842	If there are any code references in this array (you can C<push> to it	968	If there are any code references in this array (you can C<push> to it
843	before or after loading AnyEvent), then they will called directly after	969	before or after loading AnyEvent), then they will called directly after
844	the event loop has been chosen.	970	the event loop has been chosen.
845		971
846	You should check C<$AnyEvent::MODEL> before adding to this array, though:	972	You should check C<$AnyEvent::MODEL> before adding to this array, though:
847	if it contains a true value then the event loop has already been detected,	973	if it is defined then the event loop has already been detected, and the
848	and the array will be ignored.	974	array will be ignored.
849		975
850	Best use C<AnyEvent::post_detect { BLOCK }> instead.	976	Best use C<AnyEvent::post_detect { BLOCK }> when your application allows
		977	it, as it takes care of these details.
		978
		979	This variable is mainly useful for modules that can do something useful
		980	when AnyEvent is used and thus want to know when it is initialised, but do
		981	not need to even load it by default. This array provides the means to hook
		982	into AnyEvent passively, without loading it.
		983
		984	Example: To load Coro::AnyEvent whenever Coro and AnyEvent are used
		985	together, you could put this into Coro (this is the actual code used by
		986	Coro to accomplish this):
		987
		988	if (defined $AnyEvent::MODEL) {
		989	# AnyEvent already initialised, so load Coro::AnyEvent
		990	require Coro::AnyEvent;
		991	} else {
		992	# AnyEvent not yet initialised, so make sure to load Coro::AnyEvent
		993	# as soon as it is
		994	push @AnyEvent::post_detect, sub { require Coro::AnyEvent };
		995	}
851		996
852	=back	997	=back
853		998
854	=head1 WHAT TO DO IN A MODULE	999	=head1 WHAT TO DO IN A MODULE
855		1000
…		…
1002		1147
1003	=cut	1148	=cut
1004		1149
1005	package AnyEvent;	1150	package AnyEvent;
1006		1151
1007	no warnings;	1152	# basically a tuned-down version of common::sense
1008	use strict qw(vars subs);	1153	sub common_sense {
		1154	# from common:.sense 1.0
		1155	${^WARNING_BITS} = "\xfc\x3f\x33\x00\x0f\xf3\xcf\xc0\xf3\xfc\x33\x00";
		1156	# use strict vars subs - NO UTF-8, as Util.pm doesn't like this atm. (uts46data.pl)
		1157	$^H |= 0x00000600;
		1158	}
1009		1159
		1160	BEGIN { AnyEvent::common_sense }
		1161
1010	use Carp;	1162	use Carp ();
1011		1163
1012	our $VERSION = 4.801;	1164	our $VERSION = '5.26';
1013	our $MODEL;	1165	our $MODEL;
1014		1166
1015	our $AUTOLOAD;	1167	our $AUTOLOAD;
1016	our @ISA;	1168	our @ISA;
1017		1169
1018	our @REGISTRY;	1170	our @REGISTRY;
1019		1171
1020	our $WIN32;	1172	our $VERBOSE;
1021		1173
1022	BEGIN {	1174	BEGIN {
1023	eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }";	1175	require "AnyEvent/constants.pl";
		1176
1024	eval "sub TAINT(){ " . (${^TAINT}*1) . " }";	1177	eval "sub TAINT (){" . (${^TAINT}*1) . "}";
1025		1178
1026	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}	1179	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}
1027	if ${^TAINT};	1180	if ${^TAINT};
1028	}
1029		1181
1030	our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1;	1182	$VERBOSE = $ENV{PERL_ANYEVENT_VERBOSE}*1;
		1183
		1184	}
		1185
		1186	our $MAX_SIGNAL_LATENCY = 10;
1031		1187
1032	our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred	1188	our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred
1033		1189
1034	{	1190	{
1035	my $idx;	1191	my $idx;
…		…
1037	for reverse split /\s*,\s*/,	1193	for reverse split /\s*,\s*/,
1038	$ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";	1194	$ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";
1039	}	1195	}
1040		1196
1041	my @models = (	1197	my @models = (
1042	[EV:: => AnyEvent::Impl::EV::],	1198	[EV:: => AnyEvent::Impl::EV:: , 1],
1043	[Event:: => AnyEvent::Impl::Event::],
1044	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::],	1199	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl:: , 1],
1045	# everything below here will not be autoprobed	1200	# everything below here will not (normally) be autoprobed
1046	# as the pureperl backend should work everywhere	1201	# as the pureperl backend should work everywhere
1047	# and is usually faster	1202	# and is usually faster
		1203	[Event:: => AnyEvent::Impl::Event::, 1],
1048	[Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers	1204	[Glib:: => AnyEvent::Impl::Glib:: , 1], # becomes extremely slow with many watchers
1049	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy	1205	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
		1206	[Irssi:: => AnyEvent::Impl::Irssi::], # Irssi has a bogus "Event" package
1050	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles	1207	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
		1208	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program
1051	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza	1209	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
1052	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program
1053	[Wx:: => AnyEvent::Impl::POE::],	1210	[Wx:: => AnyEvent::Impl::POE::],
1054	[Prima:: => AnyEvent::Impl::POE::],	1211	[Prima:: => AnyEvent::Impl::POE::],
1055	# IO::Async is just too broken - we would need workarounds for its	1212	# IO::Async is just too broken - we would need workarounds for its
1056	# byzantine signal and broken child handling, among others.	1213	# byzantine signal and broken child handling, among others.
1057	# IO::Async is rather hard to detect, as it doesn't have any	1214	# IO::Async is rather hard to detect, as it doesn't have any
1058	# obvious default class.	1215	# obvious default class.
1059	# [IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program	1216	[IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program
1060	# [IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program	1217	[IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program
1061	# [IO::Async::Notifier:: => AnyEvent::Impl::IOAsync::], # requires special main program	1218	[IO::Async::Notifier:: => AnyEvent::Impl::IOAsync::], # requires special main program
		1219	[AnyEvent::Impl::IOAsync:: => AnyEvent::Impl::IOAsync::], # requires special main program
1062	);	1220	);
1063		1221
1064	our %method = map +($_ => 1),	1222	our %method = map +($_ => 1),
1065	qw(io timer time now now_update signal child idle condvar one_event DESTROY);	1223	qw(io timer time now now_update signal child idle condvar one_event DESTROY);
1066		1224
1067	our @post_detect;	1225	our @post_detect;
1068		1226
1069	sub post_detect(&) {	1227	sub post_detect(&) {
1070	my ($cb) = @_;	1228	my ($cb) = @_;
1071		1229
1072	if ($MODEL) {
1073	$cb->();
1074
1075	1
1076	} else {
1077	push @post_detect, $cb;	1230	push @post_detect, $cb;
1078		1231
1079	defined wantarray	1232	defined wantarray
1080	? bless \$cb, "AnyEvent::Util::postdetect"	1233	? bless \$cb, "AnyEvent::Util::postdetect"
1081	: ()	1234	: ()
1082	}
1083	}	1235	}
1084		1236
1085	sub AnyEvent::Util::postdetect::DESTROY {	1237	sub AnyEvent::Util::postdetect::DESTROY {
1086	@post_detect = grep $_ != ${$_[0]}, @post_detect;	1238	@post_detect = grep $_ != ${$_[0]}, @post_detect;
1087	}	1239	}
1088		1240
1089	sub detect() {	1241	sub detect() {
		1242	# free some memory
		1243	*detect = sub () { $MODEL };
		1244
		1245	local $!; # for good measure
		1246	local $SIG{__DIE__};
		1247
		1248	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {
		1249	my $model = "AnyEvent::Impl::$1";
		1250	if (eval "require $model") {
		1251	$MODEL = $model;
		1252	warn "AnyEvent: loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.\n" if $VERBOSE >= 2;
		1253	} else {
		1254	warn "AnyEvent: unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@" if $VERBOSE;
		1255	}
		1256	}
		1257
		1258	# check for already loaded models
1090	unless ($MODEL) {	1259	unless ($MODEL) {
1091	no strict 'refs';	1260	for (@REGISTRY, @models) {
1092	local $SIG{__DIE__};	1261	my ($package, $model) = @$_;
1093		1262	if (${"$package\::VERSION"} > 0) {
1094	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {
1095	my $model = "AnyEvent::Impl::$1";
1096	if (eval "require $model") {	1263	if (eval "require $model") {
1097	$MODEL = $model;	1264	$MODEL = $model;
1098	warn "AnyEvent: loaded model '$model' (forced by \$PERL_ANYEVENT_MODEL), using it.\n" if $verbose > 1;	1265	warn "AnyEvent: autodetected model '$model', using it.\n" if $VERBOSE >= 2;
1099	} else {	1266	last;
1100	warn "AnyEvent: unable to load model '$model' (from \$PERL_ANYEVENT_MODEL):\n$@" if $verbose;	1267	}
1101	}	1268	}
1102	}	1269	}
1103		1270
1104	# check for already loaded models
1105	unless ($MODEL) {	1271	unless ($MODEL) {
		1272	# try to autoload a model
1106	for (@REGISTRY, @models) {	1273	for (@REGISTRY, @models) {
1107	my ($package, $model) = @$_;	1274	my ($package, $model, $autoload) = @$_;
		1275	if (
		1276	$autoload
		1277	and eval "require $package"
1108	if (${"$package\::VERSION"} > 0) {	1278	and ${"$package\::VERSION"} > 0
1109	if (eval "require $model") {	1279	and eval "require $model"
		1280	) {
1110	$MODEL = $model;	1281	$MODEL = $model;
1111	warn "AnyEvent: autodetected model '$model', using it.\n" if $verbose > 1;	1282	warn "AnyEvent: autoloaded model '$model', using it.\n" if $VERBOSE >= 2;
1112	last;	1283	last;
1113	}
1114	}	1284	}
1115	}	1285	}
1116		1286
1117	unless ($MODEL) {
1118	# try to load a model
1119
1120	for (@REGISTRY, @models) {
1121	my ($package, $model) = @$_;
1122	if (eval "require $package"
1123	and ${"$package\::VERSION"} > 0
1124	and eval "require $model") {
1125	$MODEL = $model;
1126	warn "AnyEvent: autoprobed model '$model', using it.\n" if $verbose > 1;
1127	last;
1128	}
1129	}
1130
1131	$MODEL	1287	$MODEL
1132	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.\n";	1288	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.\n";
1133	}
1134	}	1289	}
1135
1136	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
1137
1138	unshift @ISA, $MODEL;
1139
1140	require AnyEvent::Strict if $ENV{PERL_ANYEVENT_STRICT};
1141
1142	(shift @post_detect)->() while @post_detect;
1143	}	1290	}
		1291
		1292	@models = (); # free probe data
		1293
		1294	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
		1295	unshift @ISA, $MODEL;
		1296
		1297	# now nuke some methods that are overriden by the backend.
		1298	# SUPER is not allowed.
		1299	for (qw(time signal child idle)) {
		1300	undef &{"AnyEvent::Base::$_"}
		1301	if defined &{"$MODEL\::$_"};
		1302	}
		1303
		1304	require AnyEvent::Strict if $ENV{PERL_ANYEVENT_STRICT};
		1305
		1306	(shift @post_detect)->() while @post_detect;
		1307
		1308	*post_detect = sub(&) {
		1309	shift->();
		1310
		1311	undef
		1312	};
1144		1313
1145	$MODEL	1314	$MODEL
1146	}	1315	}
1147		1316
1148	sub AUTOLOAD {	1317	sub AUTOLOAD {
1149	(my $func = $AUTOLOAD) =~ s/.*://;	1318	(my $func = $AUTOLOAD) =~ s/.*://;
1150		1319
1151	$method{$func}	1320	$method{$func}
1152	or croak "$func: not a valid method for AnyEvent objects";	1321	or Carp::croak "$func: not a valid AnyEvent class method";
1153		1322
1154	detect unless $MODEL;	1323	detect;
1155		1324
1156	my $class = shift;	1325	my $class = shift;
1157	$class->$func (@_);	1326	$class->$func (@_);
1158	}	1327	}
1159		1328
…		…
1162	# allow only one watcher per fd, so we dup it to get a different one).	1331	# allow only one watcher per fd, so we dup it to get a different one).
1163	sub _dupfh($$;$$) {	1332	sub _dupfh($$;$$) {
1164	my ($poll, $fh, $r, $w) = @_;	1333	my ($poll, $fh, $r, $w) = @_;
1165		1334
1166	# cygwin requires the fh mode to be matching, unix doesn't	1335	# cygwin requires the fh mode to be matching, unix doesn't
1167	my ($rw, $mode) = $poll eq "r" ? ($r, "<") : ($w, ">");	1336	my ($rw, $mode) = $poll eq "r" ? ($r, "<&") : ($w, ">&");
1168		1337
1169	open my $fh2, "$mode&", $fh	1338	open my $fh2, $mode, $fh
1170	or die "AnyEvent->io: cannot dup() filehandle in mode '$poll': $!,";	1339	or die "AnyEvent->io: cannot dup() filehandle in mode '$poll': $!,";
1171		1340
1172	# we assume CLOEXEC is already set by perl in all important cases	1341	# we assume CLOEXEC is already set by perl in all important cases
1173		1342
1174	($fh2, $rw)	1343	($fh2, $rw)
1175	}	1344	}
1176		1345
		1346	=head1 SIMPLIFIED AE API
		1347
		1348	Starting with version 5.0, AnyEvent officially supports a second, much
		1349	simpler, API that is designed to reduce the calling, typing and memory
		1350	overhead by using function call syntax and a fixed number of parameters.
		1351
		1352	See the L<AE> manpage for details.
		1353
		1354	=cut
		1355
		1356	package AE;
		1357
		1358	our $VERSION = $AnyEvent::VERSION;
		1359
		1360	# fall back to the main API by default - backends and AnyEvent::Base
		1361	# implementations can overwrite these.
		1362
		1363	sub io($$$) {
		1364	AnyEvent->io (fh => $_[0], poll => $_[1] ? "w" : "r", cb => $_[2])
		1365	}
		1366
		1367	sub timer($$$) {
		1368	AnyEvent->timer (after => $_[0], interval => $_[1], cb => $_[2])
		1369	}
		1370
		1371	sub signal($$) {
		1372	AnyEvent->signal (signal => $_[0], cb => $_[1])
		1373	}
		1374
		1375	sub child($$) {
		1376	AnyEvent->child (pid => $_[0], cb => $_[1])
		1377	}
		1378
		1379	sub idle($) {
		1380	AnyEvent->idle (cb => $_[0])
		1381	}
		1382
		1383	sub cv(;&) {
		1384	AnyEvent->condvar (@_ ? (cb => $_[0]) : ())
		1385	}
		1386
		1387	sub now() {
		1388	AnyEvent->now
		1389	}
		1390
		1391	sub now_update() {
		1392	AnyEvent->now_update
		1393	}
		1394
		1395	sub time() {
		1396	AnyEvent->time
		1397	}
		1398
1177	package AnyEvent::Base;	1399	package AnyEvent::Base;
1178		1400
1179	# default implementations for many methods	1401	# default implementations for many methods
1180		1402
1181	BEGIN {	1403	sub time {
		1404	eval q{ # poor man's autoloading {}
		1405	# probe for availability of Time::HiRes
1182	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {	1406	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {
		1407	warn "AnyEvent: using Time::HiRes for sub-second timing accuracy.\n" if $VERBOSE >= 8;
1183	*_time = \&Time::HiRes::time;	1408	*AE::time = \&Time::HiRes::time;
1184	# if (eval "use POSIX (); (POSIX::times())...	1409	# if (eval "use POSIX (); (POSIX::times())...
1185	} else {	1410	} else {
		1411	warn "AnyEvent: using built-in time(), WARNING, no sub-second resolution!\n" if $VERBOSE;
1186	*_time = sub { time }; # epic fail	1412	*AE::time = sub (){ time }; # epic fail
		1413	}
		1414
		1415	*time = sub { AE::time }; # different prototypes
		1416	};
		1417	die if $@;
		1418
		1419	&time
		1420	}
		1421
		1422	*now = \&time;
		1423
		1424	sub now_update { }
		1425
		1426	# default implementation for ->condvar
		1427
		1428	sub condvar {
		1429	eval q{ # poor man's autoloading {}
		1430	*condvar = sub {
		1431	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"
		1432	};
		1433
		1434	*AE::cv = sub (;&) {
		1435	bless { @_ ? (_ae_cb => shift) : () }, "AnyEvent::CondVar"
		1436	};
		1437	};
		1438	die if $@;
		1439
		1440	&condvar
		1441	}
		1442
		1443	# default implementation for ->signal
		1444
		1445	our $HAVE_ASYNC_INTERRUPT;
		1446
		1447	sub _have_async_interrupt() {
		1448	$HAVE_ASYNC_INTERRUPT = 1*(!$ENV{PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT}
		1449	&& eval "use Async::Interrupt 1.02 (); 1")
		1450	unless defined $HAVE_ASYNC_INTERRUPT;
		1451
		1452	$HAVE_ASYNC_INTERRUPT
		1453	}
		1454
		1455	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);
		1456	our (%SIG_ASY, %SIG_ASY_W);
		1457	our ($SIG_COUNT, $SIG_TW);
		1458
		1459	# install a dummy wakeup watcher to reduce signal catching latency
		1460	# used by Impls
		1461	sub _sig_add() {
		1462	unless ($SIG_COUNT++) {
		1463	# try to align timer on a full-second boundary, if possible
		1464	my $NOW = AE::now;
		1465
		1466	$SIG_TW = AE::timer
		1467	$MAX_SIGNAL_LATENCY - ($NOW - int $NOW),
		1468	$MAX_SIGNAL_LATENCY,
		1469	sub { } # just for the PERL_ASYNC_CHECK
		1470	;
1187	}	1471	}
1188	}	1472	}
1189		1473
1190	sub time { _time }	1474	sub _sig_del {
1191	sub now { _time }	1475	undef $SIG_TW
1192	sub now_update { }	1476	unless --$SIG_COUNT;
1193
1194	# default implementation for ->condvar
1195
1196	sub condvar {
1197	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"
1198	}	1477	}
1199		1478
1200	# default implementation for ->signal	1479	our $_sig_name_init; $_sig_name_init = sub {
		1480	eval q{ # poor man's autoloading {}
		1481	undef $_sig_name_init;
1201		1482
1202	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);	1483	if (_have_async_interrupt) {
		1484	*sig2num = \&Async::Interrupt::sig2num;
		1485	*sig2name = \&Async::Interrupt::sig2name;
		1486	} else {
		1487	require Config;
1203		1488
1204	sub _signal_exec {	1489	my %signame2num;
1205	sysread $SIGPIPE_R, my $dummy, 4;	1490	@signame2num{ split ' ', $Config::Config{sig_name} }
		1491	= split ' ', $Config::Config{sig_num};
1206		1492
1207	while (%SIG_EV) {	1493	my @signum2name;
1208	for (keys %SIG_EV) {	1494	@signum2name[values %signame2num] = keys %signame2num;
1209	delete $SIG_EV{$_};	1495
1210	$_->() for values %{ $SIG_CB{$_} || {} };	1496	*sig2num = sub($) {
		1497	$_[0] > 0 ? shift : $signame2num{+shift}
		1498	};
		1499	*sig2name = sub ($) {
		1500	$_[0] > 0 ? $signum2name[+shift] : shift
		1501	};
1211	}	1502	}
1212	}	1503	};
1213	}	1504	die if $@;
		1505	};
		1506
		1507	sub sig2num ($) { &$_sig_name_init; &sig2num }
		1508	sub sig2name($) { &$_sig_name_init; &sig2name }
1214		1509
1215	sub signal {	1510	sub signal {
1216	my (undef, %arg) = @_;	1511	eval q{ # poor man's autoloading {}
		1512	# probe for availability of Async::Interrupt
		1513	if (_have_async_interrupt) {
		1514	warn "AnyEvent: using Async::Interrupt for race-free signal handling.\n" if $VERBOSE >= 8;
1217		1515
1218	unless ($SIGPIPE_R) {	1516	$SIGPIPE_R = new Async::Interrupt::EventPipe;
1219	require Fcntl;	1517	$SIG_IO = AE::io $SIGPIPE_R->fileno, 0, \&_signal_exec;
1220		1518
1221	if (AnyEvent::WIN32) {
1222	require AnyEvent::Util;
1223
1224	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
1225	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R) if $SIGPIPE_R;
1226	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W) if $SIGPIPE_W; # just in case
1227	} else {	1519	} else {
		1520	warn "AnyEvent: using emulated perl signal handling with latency timer.\n" if $VERBOSE >= 8;
		1521
		1522	if (AnyEvent::WIN32) {
		1523	require AnyEvent::Util;
		1524
		1525	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
		1526	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R, 1) if $SIGPIPE_R;
		1527	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W, 1) if $SIGPIPE_W; # just in case
		1528	} else {
1228	pipe $SIGPIPE_R, $SIGPIPE_W;	1529	pipe $SIGPIPE_R, $SIGPIPE_W;
1229	fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R;	1530	fcntl $SIGPIPE_R, AnyEvent::F_SETFL, AnyEvent::O_NONBLOCK if $SIGPIPE_R;
1230	fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case	1531	fcntl $SIGPIPE_W, AnyEvent::F_SETFL, AnyEvent::O_NONBLOCK if $SIGPIPE_W; # just in case
1231		1532
1232	# not strictly required, as $^F is normally 2, but let's make sure...	1533	# not strictly required, as $^F is normally 2, but let's make sure...
1233	fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;	1534	fcntl $SIGPIPE_R, AnyEvent::F_SETFD, AnyEvent::FD_CLOEXEC;
1234	fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;	1535	fcntl $SIGPIPE_W, AnyEvent::F_SETFD, AnyEvent::FD_CLOEXEC;
		1536	}
		1537
		1538	$SIGPIPE_R
		1539	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";
		1540
		1541	$SIG_IO = AE::io $SIGPIPE_R, 0, \&_signal_exec;
1235	}	1542	}
1236		1543
1237	$SIGPIPE_R	1544	*signal = $HAVE_ASYNC_INTERRUPT
1238	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";	1545	? sub {
		1546	my (undef, %arg) = @_;
1239		1547
1240	$SIG_IO = AnyEvent->io (fh => $SIGPIPE_R, poll => "r", cb => \&_signal_exec);	1548	# async::interrupt
1241	}
1242
1243	my $signal = uc $arg{signal}	1549	my $signal = sig2num $arg{signal};
1244	or Carp::croak "required option 'signal' is missing";
1245
1246	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};	1550	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
		1551
		1552	$SIG_ASY{$signal} ||= new Async::Interrupt
		1553	cb => sub { undef $SIG_EV{$signal} },
		1554	signal => $signal,
		1555	pipe => [$SIGPIPE_R->filenos],
		1556	pipe_autodrain => 0,
		1557	;
		1558
		1559	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
		1560	}
		1561	: sub {
		1562	my (undef, %arg) = @_;
		1563
		1564	# pure perl
		1565	my $signal = sig2name $arg{signal};
		1566	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
		1567
1247	$SIG{$signal} ||= sub {	1568	$SIG{$signal} ||= sub {
1248	local $!;	1569	local $!;
1249	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;	1570	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;
1250	undef $SIG_EV{$signal};	1571	undef $SIG_EV{$signal};
		1572	};
		1573
		1574	# can't do signal processing without introducing races in pure perl,
		1575	# so limit the signal latency.
		1576	_sig_add;
		1577
		1578	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
		1579	}
		1580	;
		1581
		1582	*AnyEvent::Base::signal::DESTROY = sub {
		1583	my ($signal, $cb) = @{$_[0]};
		1584
		1585	_sig_del;
		1586
		1587	delete $SIG_CB{$signal}{$cb};
		1588
		1589	$HAVE_ASYNC_INTERRUPT
		1590	? delete $SIG_ASY{$signal}
		1591	: # delete doesn't work with older perls - they then
		1592	# print weird messages, or just unconditionally exit
		1593	# instead of getting the default action.
		1594	undef $SIG{$signal}
		1595	unless keys %{ $SIG_CB{$signal} };
		1596	};
		1597
		1598	*_signal_exec = sub {
		1599	$HAVE_ASYNC_INTERRUPT
		1600	? $SIGPIPE_R->drain
		1601	: sysread $SIGPIPE_R, (my $dummy), 9;
		1602
		1603	while (%SIG_EV) {
		1604	for (keys %SIG_EV) {
		1605	delete $SIG_EV{$_};
		1606	$_->() for values %{ $SIG_CB{$_} || {} };
		1607	}
		1608	}
		1609	};
1251	};	1610	};
		1611	die if $@;
1252		1612
1253	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"	1613	&signal
1254	}
1255
1256	sub AnyEvent::Base::signal::DESTROY {
1257	my ($signal, $cb) = @{$_[0]};
1258
1259	delete $SIG_CB{$signal}{$cb};
1260
1261	# delete doesn't work with older perls - they then
1262	# print weird messages, or just unconditionally exit
1263	# instead of getting the default action.
1264	undef $SIG{$signal} unless keys %{ $SIG_CB{$signal} };
1265	}	1614	}
1266		1615
1267	# default implementation for ->child	1616	# default implementation for ->child
1268		1617
1269	our %PID_CB;	1618	our %PID_CB;
1270	our $CHLD_W;	1619	our $CHLD_W;
1271	our $CHLD_DELAY_W;	1620	our $CHLD_DELAY_W;
1272	our $WNOHANG;	1621	our $WNOHANG;
1273		1622
1274	sub _sigchld {	1623	# used by many Impl's
1275	while (0 < (my $pid = waitpid -1, $WNOHANG)) {	1624	sub _emit_childstatus($$) {
		1625	my (undef, $rpid, $rstatus) = @_;
		1626
		1627	$_->($rpid, $rstatus)
1276	$_->($pid, $?) for (values %{ $PID_CB{$pid} || {} }),	1628	for values %{ $PID_CB{$rpid} || {} },
1277	(values %{ $PID_CB{0} || {} });	1629	values %{ $PID_CB{0} || {} };
1278	}
1279	}	1630	}
1280		1631
1281	sub child {	1632	sub child {
		1633	eval q{ # poor man's autoloading {}
		1634	*_sigchld = sub {
		1635	my $pid;
		1636
		1637	AnyEvent->_emit_childstatus ($pid, $?)
		1638	while ($pid = waitpid -1, $WNOHANG) > 0;
		1639	};
		1640
		1641	*child = sub {
1282	my (undef, %arg) = @_;	1642	my (undef, %arg) = @_;
1283		1643
1284	defined (my $pid = $arg{pid} + 0)	1644	defined (my $pid = $arg{pid} + 0)
1285	or Carp::croak "required option 'pid' is missing";	1645	or Carp::croak "required option 'pid' is missing";
1286		1646
1287	$PID_CB{$pid}{$arg{cb}} = $arg{cb};	1647	$PID_CB{$pid}{$arg{cb}} = $arg{cb};
1288		1648
		1649	# WNOHANG is almost cetrainly 1 everywhere
		1650	$WNOHANG ||= $^O =~ /^(?:openbsd|netbsd|linux|freebsd|cygwin|MSWin32)$/
		1651	? 1
1289	$WNOHANG ||= eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1;	1652	: eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1;
1290		1653
1291	unless ($CHLD_W) {	1654	unless ($CHLD_W) {
1292	$CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld);	1655	$CHLD_W = AE::signal CHLD => \&_sigchld;
1293	# child could be a zombie already, so make at least one round	1656	# child could be a zombie already, so make at least one round
1294	&_sigchld;	1657	&_sigchld;
1295	}	1658	}
1296		1659
1297	bless [$pid, $arg{cb}], "AnyEvent::Base::child"	1660	bless [$pid, $arg{cb}], "AnyEvent::Base::child"
1298	}	1661	};
1299		1662
1300	sub AnyEvent::Base::child::DESTROY {	1663	*AnyEvent::Base::child::DESTROY = sub {
1301	my ($pid, $cb) = @{$_[0]};	1664	my ($pid, $cb) = @{$_[0]};
1302		1665
1303	delete $PID_CB{$pid}{$cb};	1666	delete $PID_CB{$pid}{$cb};
1304	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };	1667	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };
1305		1668
1306	undef $CHLD_W unless keys %PID_CB;	1669	undef $CHLD_W unless keys %PID_CB;
		1670	};
		1671	};
		1672	die if $@;
		1673
		1674	&child
1307	}	1675	}
1308		1676
1309	# idle emulation is done by simply using a timer, regardless	1677	# idle emulation is done by simply using a timer, regardless
1310	# of whether the process is idle or not, and not letting	1678	# of whether the process is idle or not, and not letting
1311	# the callback use more than 50% of the time.	1679	# the callback use more than 50% of the time.
1312	sub idle {	1680	sub idle {
		1681	eval q{ # poor man's autoloading {}
		1682	*idle = sub {
1313	my (undef, %arg) = @_;	1683	my (undef, %arg) = @_;
1314		1684
1315	my ($cb, $w, $rcb) = $arg{cb};	1685	my ($cb, $w, $rcb) = $arg{cb};
1316		1686
1317	$rcb = sub {	1687	$rcb = sub {
1318	if ($cb) {	1688	if ($cb) {
1319	$w = _time;	1689	$w = _time;
1320	&$cb;	1690	&$cb;
1321	$w = _time - $w;	1691	$w = _time - $w;
1322		1692
1323	# never use more then 50% of the time for the idle watcher,	1693	# never use more then 50% of the time for the idle watcher,
1324	# within some limits	1694	# within some limits
1325	$w = 0.0001 if $w < 0.0001;	1695	$w = 0.0001 if $w < 0.0001;
1326	$w = 5 if $w > 5;	1696	$w = 5 if $w > 5;
1327		1697
1328	$w = AnyEvent->timer (after => $w, cb => $rcb);	1698	$w = AE::timer $w, 0, $rcb;
1329	} else {	1699	} else {
1330	# clean up...	1700	# clean up...
1331	undef $w;	1701	undef $w;
1332	undef $rcb;	1702	undef $rcb;
		1703	}
		1704	};
		1705
		1706	$w = AE::timer 0.05, 0, $rcb;
		1707
		1708	bless \\$cb, "AnyEvent::Base::idle"
1333	}	1709	};
		1710
		1711	*AnyEvent::Base::idle::DESTROY = sub {
		1712	undef $${$_[0]};
		1713	};
1334	};	1714	};
		1715	die if $@;
1335		1716
1336	$w = AnyEvent->timer (after => 0.05, cb => $rcb);	1717	&idle
1337
1338	bless \\$cb, "AnyEvent::Base::idle"
1339	}
1340
1341	sub AnyEvent::Base::idle::DESTROY {
1342	undef $${$_[0]};
1343	}	1718	}
1344		1719
1345	package AnyEvent::CondVar;	1720	package AnyEvent::CondVar;
1346		1721
1347	our @ISA = AnyEvent::CondVar::Base::;	1722	our @ISA = AnyEvent::CondVar::Base::;
1348		1723
1349	package AnyEvent::CondVar::Base;	1724	package AnyEvent::CondVar::Base;
1350		1725
1351	use overload	1726	#use overload
1352	'&{}' => sub { my $self = shift; sub { $self->send (@_) } },	1727	# '&{}' => sub { my $self = shift; sub { $self->send (@_) } },
1353	fallback => 1;	1728	# fallback => 1;
		1729
		1730	# save 300+ kilobytes by dirtily hardcoding overloading
		1731	${"AnyEvent::CondVar::Base::OVERLOAD"}{dummy}++; # Register with magic by touching.
		1732	*{'AnyEvent::CondVar::Base::()'} = sub { }; # "Make it findable via fetchmethod."
		1733	*{'AnyEvent::CondVar::Base::(&{}'} = sub { my $self = shift; sub { $self->send (@_) } }; # &{}
		1734	${'AnyEvent::CondVar::Base::()'} = 1; # fallback
		1735
		1736	our $WAITING;
1354		1737
1355	sub _send {	1738	sub _send {
1356	# nop	1739	# nop
1357	}	1740	}
1358		1741
…		…
1371	sub ready {	1754	sub ready {
1372	$_[0]{_ae_sent}	1755	$_[0]{_ae_sent}
1373	}	1756	}
1374		1757
1375	sub _wait {	1758	sub _wait {
		1759	$WAITING
		1760	and !$_[0]{_ae_sent}
		1761	and Carp::croak "AnyEvent::CondVar: recursive blocking wait detected";
		1762
		1763	local $WAITING = 1;
1376	AnyEvent->one_event while !$_[0]{_ae_sent};	1764	AnyEvent->one_event while !$_[0]{_ae_sent};
1377	}	1765	}
1378		1766
1379	sub recv {	1767	sub recv {
1380	$_[0]->_wait;	1768	$_[0]->_wait;
…		…
1382	Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak};	1770	Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak};
1383	wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0]	1771	wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0]
1384	}	1772	}
1385		1773
1386	sub cb {	1774	sub cb {
1387	$_[0]{_ae_cb} = $_[1] if @_ > 1;	1775	my $cv = shift;
		1776
		1777	@_
		1778	and $cv->{_ae_cb} = shift
		1779	and $cv->{_ae_sent}
		1780	and (delete $cv->{_ae_cb})->($cv);
		1781
1388	$_[0]{_ae_cb}	1782	$cv->{_ae_cb}
1389	}	1783	}
1390		1784
1391	sub begin {	1785	sub begin {
1392	++$_[0]{_ae_counter};	1786	++$_[0]{_ae_counter};
1393	$_[0]{_ae_end_cb} = $_[1] if @_ > 1;	1787	$_[0]{_ae_end_cb} = $_[1] if @_ > 1;
…		…
1442	C<PERL_ANYEVENT_MODEL>.	1836	C<PERL_ANYEVENT_MODEL>.
1443		1837
1444	When set to C<2> or higher, cause AnyEvent to report to STDERR which event	1838	When set to C<2> or higher, cause AnyEvent to report to STDERR which event
1445	model it chooses.	1839	model it chooses.
1446		1840
		1841	When set to C<8> or higher, then AnyEvent will report extra information on
		1842	which optional modules it loads and how it implements certain features.
		1843
1447	=item C<PERL_ANYEVENT_STRICT>	1844	=item C<PERL_ANYEVENT_STRICT>
1448		1845
1449	AnyEvent does not do much argument checking by default, as thorough	1846	AnyEvent does not do much argument checking by default, as thorough
1450	argument checking is very costly. Setting this variable to a true value	1847	argument checking is very costly. Setting this variable to a true value
1451	will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly	1848	will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly
1452	check the arguments passed to most method calls. If it finds any problems,	1849	check the arguments passed to most method calls. If it finds any problems,
1453	it will croak.	1850	it will croak.
1454		1851
1455	In other words, enables "strict" mode.	1852	In other words, enables "strict" mode.
1456		1853
1457	Unlike C<use strict>, it is definitely recommended to keep it off in	1854	Unlike C<use strict> (or it's modern cousin, C<< use L<common::sense>
1458	production. Keeping C<PERL_ANYEVENT_STRICT=1> in your environment while	1855	>>, it is definitely recommended to keep it off in production. Keeping
1459	developing programs can be very useful, however.	1856	C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs
		1857	can be very useful, however.
1460		1858
1461	=item C<PERL_ANYEVENT_MODEL>	1859	=item C<PERL_ANYEVENT_MODEL>
1462		1860
1463	This can be used to specify the event model to be used by AnyEvent, before	1861	This can be used to specify the event model to be used by AnyEvent, before
1464	auto detection and -probing kicks in. It must be a string consisting	1862	auto detection and -probing kicks in. It must be a string consisting
…		…
1526		1924
1527	When neither C<ca_file> nor C<ca_path> was specified during	1925	When neither C<ca_file> nor C<ca_path> was specified during
1528	L<AnyEvent::TLS> context creation, and either of these environment	1926	L<AnyEvent::TLS> context creation, and either of these environment
1529	variables exist, they will be used to specify CA certificate locations	1927	variables exist, they will be used to specify CA certificate locations
1530	instead of a system-dependent default.	1928	instead of a system-dependent default.
		1929
		1930	=item C<PERL_ANYEVENT_AVOID_GUARD> and C<PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT>
		1931
		1932	When these are set to C<1>, then the respective modules are not
		1933	loaded. Mostly good for testing AnyEvent itself.
1531		1934
1532	=back	1935	=back
1533		1936
1534	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE	1937	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE
1535		1938
…		…
1593	warn "read: $input\n"; # output what has been read	1996	warn "read: $input\n"; # output what has been read
1594	$cv->send if $input =~ /^q/i; # quit program if /^q/i	1997	$cv->send if $input =~ /^q/i; # quit program if /^q/i
1595	},	1998	},
1596	);	1999	);
1597		2000
1598	my $time_watcher; # can only be used once
1599
1600	sub new_timer {
1601	$timer = AnyEvent->timer (after => 1, cb => sub {	2001	my $time_watcher = AnyEvent->timer (after => 1, interval => 1, cb => sub {
1602	warn "timeout\n"; # print 'timeout' about every second	2002	warn "timeout\n"; # print 'timeout' at most every second
1603	&new_timer; # and restart the time
1604	});	2003	});
1605	}
1606
1607	new_timer; # create first timer
1608		2004
1609	$cv->recv; # wait until user enters /^q/i	2005	$cv->recv; # wait until user enters /^q/i
1610		2006
1611	=head1 REAL-WORLD EXAMPLE	2007	=head1 REAL-WORLD EXAMPLE
1612		2008
…		…
1685		2081
1686	The actual code goes further and collects all errors (C<die>s, exceptions)	2082	The actual code goes further and collects all errors (C<die>s, exceptions)
1687	that occurred during request processing. The C<result> method detects	2083	that occurred during request processing. The C<result> method detects
1688	whether an exception as thrown (it is stored inside the $txn object)	2084	whether an exception as thrown (it is stored inside the $txn object)
1689	and just throws the exception, which means connection errors and other	2085	and just throws the exception, which means connection errors and other
1690	problems get reported tot he code that tries to use the result, not in a	2086	problems get reported to the code that tries to use the result, not in a
1691	random callback.	2087	random callback.
1692		2088
1693	All of this enables the following usage styles:	2089	All of this enables the following usage styles:
1694		2090
1695	1. Blocking:	2091	1. Blocking:
…		…
1743	through AnyEvent. The benchmark creates a lot of timers (with a zero	2139	through AnyEvent. The benchmark creates a lot of timers (with a zero
1744	timeout) and I/O watchers (watching STDOUT, a pty, to become writable,	2140	timeout) and I/O watchers (watching STDOUT, a pty, to become writable,
1745	which it is), lets them fire exactly once and destroys them again.	2141	which it is), lets them fire exactly once and destroys them again.
1746		2142
1747	Source code for this benchmark is found as F<eg/bench> in the AnyEvent	2143	Source code for this benchmark is found as F<eg/bench> in the AnyEvent
1748	distribution.	2144	distribution. It uses the L<AE> interface, which makes a real difference
		2145	for the EV and Perl backends only.
1749		2146
1750	=head3 Explanation of the columns	2147	=head3 Explanation of the columns
1751		2148
1752	I<watcher> is the number of event watchers created/destroyed. Since	2149	I<watcher> is the number of event watchers created/destroyed. Since
1753	different event models feature vastly different performances, each event	2150	different event models feature vastly different performances, each event
…		…
1774	watcher.	2171	watcher.
1775		2172
1776	=head3 Results	2173	=head3 Results
1777		2174
1778	name watchers bytes create invoke destroy comment	2175	name watchers bytes create invoke destroy comment
1779	EV/EV 400000 224 0.47 0.35 0.27 EV native interface	2176	EV/EV 100000 223 0.47 0.43 0.27 EV native interface
1780	EV/Any 100000 224 2.88 0.34 0.27 EV + AnyEvent watchers	2177	EV/Any 100000 223 0.48 0.42 0.26 EV + AnyEvent watchers
1781	CoroEV/Any 100000 224 2.85 0.35 0.28 coroutines + Coro::Signal	2178	Coro::EV/Any 100000 223 0.47 0.42 0.26 coroutines + Coro::Signal
1782	Perl/Any 100000 452 4.13 0.73 0.95 pure perl implementation	2179	Perl/Any 100000 431 2.70 0.74 0.92 pure perl implementation
1783	Event/Event 16000 517 32.20 31.80 0.81 Event native interface	2180	Event/Event 16000 516 31.16 31.84 0.82 Event native interface
1784	Event/Any 16000 590 35.85 31.55 1.06 Event + AnyEvent watchers	2181	Event/Any 16000 1203 42.61 34.79 1.80 Event + AnyEvent watchers
1785	IOAsync/Any 16000 989 38.10 32.77 11.13 via IO::Async::Loop::IO_Poll	2182	IOAsync/Any 16000 1911 41.92 27.45 16.81 via IO::Async::Loop::IO_Poll
1786	IOAsync/Any 16000 990 37.59 29.50 10.61 via IO::Async::Loop::Epoll	2183	IOAsync/Any 16000 1726 40.69 26.37 15.25 via IO::Async::Loop::Epoll
1787	Glib/Any 16000 1357 102.33 12.31 51.00 quadratic behaviour	2184	Glib/Any 16000 1118 89.00 12.57 51.17 quadratic behaviour
1788	Tk/Any 2000 1860 27.20 66.31 14.00 SEGV with >> 2000 watchers	2185	Tk/Any 2000 1346 20.96 10.75 8.00 SEGV with >> 2000 watchers
1789	POE/Event 2000 6328 109.99 751.67 14.02 via POE::Loop::Event	2186	POE/Any 2000 6951 108.97 795.32 14.24 via POE::Loop::Event
1790	POE/Select 2000 6027 94.54 809.13 579.80 via POE::Loop::Select	2187	POE/Any 2000 6648 94.79 774.40 575.51 via POE::Loop::Select
1791		2188
1792	=head3 Discussion	2189	=head3 Discussion
1793		2190
1794	The benchmark does I<not> measure scalability of the event loop very	2191	The benchmark does I<not> measure scalability of the event loop very
1795	well. For example, a select-based event loop (such as the pure perl one)	2192	well. For example, a select-based event loop (such as the pure perl one)
…		…
1807	benchmark machine, handling an event takes roughly 1600 CPU cycles with	2204	benchmark machine, handling an event takes roughly 1600 CPU cycles with
1808	EV, 3100 CPU cycles with AnyEvent's pure perl loop and almost 3000000 CPU	2205	EV, 3100 CPU cycles with AnyEvent's pure perl loop and almost 3000000 CPU
1809	cycles with POE.	2206	cycles with POE.
1810		2207
1811	C<EV> is the sole leader regarding speed and memory use, which are both	2208	C<EV> is the sole leader regarding speed and memory use, which are both
1812	maximal/minimal, respectively. Even when going through AnyEvent, it uses	2209	maximal/minimal, respectively. When using the L<AE> API there is zero
		2210	overhead (when going through the AnyEvent API create is about 5-6 times
		2211	slower, with other times being equal, so still uses far less memory than
1813	far less memory than any other event loop and is still faster than Event	2212	any other event loop and is still faster than Event natively).
1814	natively.
1815		2213
1816	The pure perl implementation is hit in a few sweet spots (both the	2214	The pure perl implementation is hit in a few sweet spots (both the
1817	constant timeout and the use of a single fd hit optimisations in the perl	2215	constant timeout and the use of a single fd hit optimisations in the perl
1818	interpreter and the backend itself). Nevertheless this shows that it	2216	interpreter and the backend itself). Nevertheless this shows that it
1819	adds very little overhead in itself. Like any select-based backend its	2217	adds very little overhead in itself. Like any select-based backend its
…		…
1893	In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100	2291	In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100
1894	(1%) are active. This mirrors the activity of large servers with many	2292	(1%) are active. This mirrors the activity of large servers with many
1895	connections, most of which are idle at any one point in time.	2293	connections, most of which are idle at any one point in time.
1896		2294
1897	Source code for this benchmark is found as F<eg/bench2> in the AnyEvent	2295	Source code for this benchmark is found as F<eg/bench2> in the AnyEvent
1898	distribution.	2296	distribution. It uses the L<AE> interface, which makes a real difference
		2297	for the EV and Perl backends only.
1899		2298
1900	=head3 Explanation of the columns	2299	=head3 Explanation of the columns
1901		2300
1902	I<sockets> is the number of sockets, and twice the number of "servers" (as	2301	I<sockets> is the number of sockets, and twice the number of "servers" (as
1903	each server has a read and write socket end).	2302	each server has a read and write socket end).
…		…
1911	a new one that moves the timeout into the future.	2310	a new one that moves the timeout into the future.
1912		2311
1913	=head3 Results	2312	=head3 Results
1914		2313
1915	name sockets create request	2314	name sockets create request
1916	EV 20000 69.01 11.16	2315	EV 20000 62.66 7.99
1917	Perl 20000 73.32 35.87	2316	Perl 20000 68.32 32.64
1918	IOAsync 20000 157.00 98.14 epoll	2317	IOAsync 20000 174.06 101.15 epoll
1919	IOAsync 20000 159.31 616.06 poll	2318	IOAsync 20000 174.67 610.84 poll
1920	Event 20000 212.62 257.32	2319	Event 20000 202.69 242.91
1921	Glib 20000 651.16 1896.30	2320	Glib 20000 557.01 1689.52
1922	POE 20000 349.67 12317.24 uses POE::Loop::Event	2321	POE 20000 341.54 12086.32 uses POE::Loop::Event
1923		2322
1924	=head3 Discussion	2323	=head3 Discussion
1925		2324
1926	This benchmark I<does> measure scalability and overall performance of the	2325	This benchmark I<does> measure scalability and overall performance of the
1927	particular event loop.	2326	particular event loop.
…		…
2053	As you can see, the AnyEvent + EV combination even beats the	2452	As you can see, the AnyEvent + EV combination even beats the
2054	hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl	2453	hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl
2055	backend easily beats IO::Lambda and POE.	2454	backend easily beats IO::Lambda and POE.
2056		2455
2057	And even the 100% non-blocking version written using the high-level (and	2456	And even the 100% non-blocking version written using the high-level (and
2058	slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda by a	2457	slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda
2059	large margin, even though it does all of DNS, tcp-connect and socket I/O	2458	higher level ("unoptimised") abstractions by a large margin, even though
2060	in a non-blocking way.	2459	it does all of DNS, tcp-connect and socket I/O in a non-blocking way.
2061		2460
2062	The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and	2461	The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and
2063	F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are	2462	F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are
2064	part of the IO::lambda distribution and were used without any changes.	2463	part of the IO::Lambda distribution and were used without any changes.
2065		2464
2066		2465
2067	=head1 SIGNALS	2466	=head1 SIGNALS
2068		2467
2069	AnyEvent currently installs handlers for these signals:	2468	AnyEvent currently installs handlers for these signals:
…		…
2074		2473
2075	A handler for C<SIGCHLD> is installed by AnyEvent's child watcher	2474	A handler for C<SIGCHLD> is installed by AnyEvent's child watcher
2076	emulation for event loops that do not support them natively. Also, some	2475	emulation for event loops that do not support them natively. Also, some
2077	event loops install a similar handler.	2476	event loops install a similar handler.
2078		2477
2079	If, when AnyEvent is loaded, SIGCHLD is set to IGNORE, then AnyEvent will	2478	Additionally, when AnyEvent is loaded and SIGCHLD is set to IGNORE, then
2080	reset it to default, to avoid losing child exit statuses.	2479	AnyEvent will reset it to default, to avoid losing child exit statuses.
2081		2480
2082	=item SIGPIPE	2481	=item SIGPIPE
2083		2482
2084	A no-op handler is installed for C<SIGPIPE> when C<$SIG{PIPE}> is C<undef>	2483	A no-op handler is installed for C<SIGPIPE> when C<$SIG{PIPE}> is C<undef>
2085	when AnyEvent gets loaded.	2484	when AnyEvent gets loaded.
…		…
2103	if $SIG{CHLD} eq 'IGNORE';	2502	if $SIG{CHLD} eq 'IGNORE';
2104		2503
2105	$SIG{PIPE} = sub { }	2504	$SIG{PIPE} = sub { }
2106	unless defined $SIG{PIPE};	2505	unless defined $SIG{PIPE};
2107		2506
		2507	=head1 RECOMMENDED/OPTIONAL MODULES
		2508
		2509	One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and
		2510	it's built-in modules) are required to use it.
		2511
		2512	That does not mean that AnyEvent won't take advantage of some additional
		2513	modules if they are installed.
		2514
		2515	This section explains which additional modules will be used, and how they
		2516	affect AnyEvent's operation.
		2517
		2518	=over 4
		2519
		2520	=item L<Async::Interrupt>
		2521
		2522	This slightly arcane module is used to implement fast signal handling: To
		2523	my knowledge, there is no way to do completely race-free and quick
		2524	signal handling in pure perl. To ensure that signals still get
		2525	delivered, AnyEvent will start an interval timer to wake up perl (and
		2526	catch the signals) with some delay (default is 10 seconds, look for
		2527	C<$AnyEvent::MAX_SIGNAL_LATENCY>).
		2528
		2529	If this module is available, then it will be used to implement signal
		2530	catching, which means that signals will not be delayed, and the event loop
		2531	will not be interrupted regularly, which is more efficient (and good for
		2532	battery life on laptops).
		2533
		2534	This affects not just the pure-perl event loop, but also other event loops
		2535	that have no signal handling on their own (e.g. Glib, Tk, Qt).
		2536
		2537	Some event loops (POE, Event, Event::Lib) offer signal watchers natively,
		2538	and either employ their own workarounds (POE) or use AnyEvent's workaround
		2539	(using C<$AnyEvent::MAX_SIGNAL_LATENCY>). Installing L<Async::Interrupt>
		2540	does nothing for those backends.
		2541
		2542	=item L<EV>
		2543
		2544	This module isn't really "optional", as it is simply one of the backend
		2545	event loops that AnyEvent can use. However, it is simply the best event
		2546	loop available in terms of features, speed and stability: It supports
		2547	the AnyEvent API optimally, implements all the watcher types in XS, does
		2548	automatic timer adjustments even when no monotonic clock is available,
		2549	can take avdantage of advanced kernel interfaces such as C<epoll> and
		2550	C<kqueue>, and is the fastest backend I<by far>. You can even embed
		2551	L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>).
		2552
		2553	If you only use backends that rely on another event loop (e.g. C<Tk>),
		2554	then this module will do nothing for you.
		2555
		2556	=item L<Guard>
		2557
		2558	The guard module, when used, will be used to implement
		2559	C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a
		2560	lot less memory), but otherwise doesn't affect guard operation much. It is
		2561	purely used for performance.
		2562
		2563	=item L<JSON> and L<JSON::XS>
		2564
		2565	One of these modules is required when you want to read or write JSON data
		2566	via L<AnyEvent::Handle>. L<JSON> is also written in pure-perl, but can take
		2567	advantage of the ultra-high-speed L<JSON::XS> module when it is installed.
		2568
		2569	=item L<Net::SSLeay>
		2570
		2571	Implementing TLS/SSL in Perl is certainly interesting, but not very
		2572	worthwhile: If this module is installed, then L<AnyEvent::Handle> (with
		2573	the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL.
		2574
		2575	=item L<Time::HiRes>
		2576
		2577	This module is part of perl since release 5.008. It will be used when the
		2578	chosen event library does not come with a timing source on it's own. The
		2579	pure-perl event loop (L<AnyEvent::Impl::Perl>) will additionally use it to
		2580	try to use a monotonic clock for timing stability.
		2581
		2582	=back
		2583
		2584
2108	=head1 FORK	2585	=head1 FORK
2109		2586
2110	Most event libraries are not fork-safe. The ones who are usually are	2587	Most event libraries are not fork-safe. The ones who are usually are
2111	because they rely on inefficient but fork-safe C<select> or C<poll>	2588	because they rely on inefficient but fork-safe C<select> or C<poll> calls
2112	calls. Only L<EV> is fully fork-aware.	2589	- higher performance APIs such as BSD's kqueue or the dreaded Linux epoll
		2590	are usually badly thought-out hacks that are incompatible with fork in
		2591	one way or another. Only L<EV> is fully fork-aware and ensures that you
		2592	continue event-processing in both parent and child (or both, if you know
		2593	what you are doing).
		2594
		2595	This means that, in general, you cannot fork and do event processing in
		2596	the child if the event library was initialised before the fork (which
		2597	usually happens when the first AnyEvent watcher is created, or the library
		2598	is loaded).
2113		2599
2114	If you have to fork, you must either do so I<before> creating your first	2600	If you have to fork, you must either do so I<before> creating your first
2115	watcher OR you must not use AnyEvent at all in the child.	2601	watcher OR you must not use AnyEvent at all in the child OR you must do
		2602	something completely out of the scope of AnyEvent.
		2603
		2604	The problem of doing event processing in the parent I<and> the child
		2605	is much more complicated: even for backends that I<are> fork-aware or
		2606	fork-safe, their behaviour is not usually what you want: fork clones all
		2607	watchers, that means all timers, I/O watchers etc. are active in both
		2608	parent and child, which is almost never what you want. USing C<exec>
		2609	to start worker children from some kind of manage rprocess is usually
		2610	preferred, because it is much easier and cleaner, at the expense of having
		2611	to have another binary.
2116		2612
2117		2613
2118	=head1 SECURITY CONSIDERATIONS	2614	=head1 SECURITY CONSIDERATIONS
2119		2615
2120	AnyEvent can be forced to load any event model via	2616	AnyEvent can be forced to load any event model via
…		…
2158	L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.	2654	L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.
2159		2655
2160	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,	2656	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,
2161	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,	2657	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,
2162	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,	2658	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,
2163	L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>.	2659	L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>, L<Anyevent::Impl::Irssi>.
2164		2660
2165	Non-blocking file handles, sockets, TCP clients and	2661	Non-blocking file handles, sockets, TCP clients and
2166	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.	2662	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.
2167		2663
2168	Asynchronous DNS: L<AnyEvent::DNS>.	2664	Asynchronous DNS: L<AnyEvent::DNS>.

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