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Revision 1.234 by root, Thu Jul 9 08:31:16 2009 UTC vs.
Revision 1.326 by root, Sun Jun 6 10:11:56 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 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 tool to do that is called a "condition variable", so called because
472	because they represent a condition that must become true.	562	they represent a condition that must become true.
		563
		564	Now is probably a good time to look at the examples further below.
473		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"
482	by calling the C<send> method (or calling the condition variable as if it	573	by calling the C<send> method (or calling the condition variable as if it
483	were a callback, read about the caveats in the description for the C<<	574	were a callback, read about the caveats in the description for the C<<
484	->send >> method).	575	->send >> method).
485		576
486	Condition variables are similar to callbacks, except that you can	577	Since condition variables are the most complex part of the AnyEvent API, here are
487	optionally wait for them. They can also be called merge points - points	578	some different mental models of what they are - pick the ones you can connect to:
488	in time where multiple outstanding events have been processed. And yet	579
489	another way to call them is transactions - each condition variable can be	580	=over 4
490	used to represent a transaction, which finishes at some point and delivers	581
491	a result.	582	=item * Condition variables are like callbacks - you can call them (and pass them instead
		583	of callbacks). Unlike callbacks however, you can also wait for them to be called.
		584
		585	=item * Condition variables are signals - one side can emit or send them,
		586	the other side can wait for them, or install a handler that is called when
		587	the signal fires.
		588
		589	=item * Condition variables are like "Merge Points" - points in your program
		590	where you merge multiple independent results/control flows into one.
		591
		592	=item * Condition variables represent a transaction - function that start
		593	some kind of transaction can return them, leaving the caller the choice
		594	between waiting in a blocking fashion, or setting a callback.
		595
		596	=item * Condition variables represent future values, or promises to deliver
		597	some result, long before the result is available.
		598
		599	=back
492		600
493	Condition variables are very useful to signal that something has finished,	601	Condition variables are very useful to signal that something has finished,
494	for example, if you write a module that does asynchronous http requests,	602	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	603	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	604	availability of results. The user can either act when the callback is
…		…
517	eventually calls C<< -> send >>, and the "consumer side", which waits	625	eventually calls C<< -> send >>, and the "consumer side", which waits
518	for the send to occur.	626	for the send to occur.
519		627
520	Example: wait for a timer.	628	Example: wait for a timer.
521		629
522	# wait till the result is ready	630	# condition: "wait till the timer is fired"
523	my $result_ready = AnyEvent->condvar;	631	my $timer_fired = AnyEvent->condvar;
524		632
525	# do something such as adding a timer	633	# create the timer - we could wait for, say
526	# or socket watcher the calls $result_ready->send	634	# a handle becomign ready, or even an
527	# when the "result" is ready.	635	# AnyEvent::HTTP request to finish, but
528	# in this case, we simply use a timer:	636	# in this case, we simply use a timer:
529	my $w = AnyEvent->timer (	637	my $w = AnyEvent->timer (
530	after => 1,	638	after => 1,
531	cb => sub { $result_ready->send },	639	cb => sub { $timer_fired->send },
532	);	640	);
533		641
534	# this "blocks" (while handling events) till the callback	642	# this "blocks" (while handling events) till the callback
535	# calls send	643	# calls ->send
536	$result_ready->recv;	644	$timer_fired->recv;
537		645
538	Example: wait for a timer, but take advantage of the fact that	646	Example: wait for a timer, but take advantage of the fact that condition
539	condition variables are also code references.	647	variables are also callable directly.
540		648
541	my $done = AnyEvent->condvar;	649	my $done = AnyEvent->condvar;
542	my $delay = AnyEvent->timer (after => 5, cb => $done);	650	my $delay = AnyEvent->timer (after => 5, cb => $done);
543	$done->recv;	651	$done->recv;
544		652
…		…
550		658
551	...	659	...
552		660
553	my @info = $couchdb->info->recv;	661	my @info = $couchdb->info->recv;
554		662
555	And this is how you would just ste a callback to be called whenever the	663	And this is how you would just set a callback to be called whenever the
556	results are available:	664	results are available:
557		665
558	$couchdb->info->cb (sub {	666	$couchdb->info->cb (sub {
559	my @info = $_[0]->recv;	667	my @info = $_[0]->recv;
560	});	668	});
…		…
578	immediately from within send.	686	immediately from within send.
579		687
580	Any arguments passed to the C<send> call will be returned by all	688	Any arguments passed to the C<send> call will be returned by all
581	future C<< ->recv >> calls.	689	future C<< ->recv >> calls.
582		690
583	Condition variables are overloaded so one can call them directly	691	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	692	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	693	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		694
592	=item $cv->croak ($error)	695	=item $cv->croak ($error)
593		696
594	Similar to send, but causes all call's to C<< ->recv >> to invoke	697	Similar to send, but causes all call's to C<< ->recv >> to invoke
595	C<Carp::croak> with the given error message/object/scalar.	698	C<Carp::croak> with the given error message/object/scalar.
596		699
597	This can be used to signal any errors to the condition variable	700	This can be used to signal any errors to the condition variable
598	user/consumer.	701	user/consumer. Doing it this way instead of calling C<croak> directly
		702	delays the error detetcion, but has the overwhelmign advantage that it
		703	diagnoses the error at the place where the result is expected, and not
		704	deep in some event clalback without connection to the actual code causing
		705	the problem.
599		706
600	=item $cv->begin ([group callback])	707	=item $cv->begin ([group callback])
601		708
602	=item $cv->end	709	=item $cv->end
603		710
…		…
605	one. For example, a function that pings many hosts in parallel might want	712	one. For example, a function that pings many hosts in parallel might want
606	to use a condition variable for the whole process.	713	to use a condition variable for the whole process.
607		714
608	Every call to C<< ->begin >> will increment a counter, and every call to	715	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	716	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	717	>>, 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	718	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.	719	>>, but that is not required. If no group callback was set, C<send> will
		720	be called without any arguments.
613		721
614	You can think of C<< $cv->send >> giving you an OR condition (one call	722	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	723	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).	724	condition (all C<begin> calls must be C<end>'ed before the condvar sends).
617		725
…		…
644	begung can potentially be zero:	752	begung can potentially be zero:
645		753
646	my $cv = AnyEvent->condvar;	754	my $cv = AnyEvent->condvar;
647		755
648	my %result;	756	my %result;
649	$cv->begin (sub { $cv->send (\%result) });	757	$cv->begin (sub { shift->send (\%result) });
650		758
651	for my $host (@list_of_hosts) {	759	for my $host (@list_of_hosts) {
652	$cv->begin;	760	$cv->begin;
653	ping_host_then_call_callback $host, sub {	761	ping_host_then_call_callback $host, sub {
654	$result{$host} = ...;	762	$result{$host} = ...;
…		…
699	function will call C<croak>.	807	function will call C<croak>.
700		808
701	In list context, all parameters passed to C<send> will be returned,	809	In list context, all parameters passed to C<send> will be returned,
702	in scalar context only the first one will be returned.	810	in scalar context only the first one will be returned.
703		811
		812	Note that doing a blocking wait in a callback is not supported by any
		813	event loop, that is, recursive invocation of a blocking C<< ->recv
		814	>> is not allowed, and the C<recv> call will C<croak> if such a
		815	condition is detected. This condition can be slightly loosened by using
		816	L<Coro::AnyEvent>, which allows you to do a blocking C<< ->recv >> from
		817	any thread that doesn't run the event loop itself.
		818
704	Not all event models support a blocking wait - some die in that case	819	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	820	(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	821	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	822	caller decide whether the call will block or not (for example, by coupling
708	condition variables with some kind of request results and supporting	823	condition variables with some kind of request results and supporting
709	callbacks so the caller knows that getting the result will not block,	824	callbacks so the caller knows that getting the result will not block,
710	while still supporting blocking waits if the caller so desires).	825	while still supporting blocking waits if the caller so desires).
711		826
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	827	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	828	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	829	time). This will work even when the event loop does not support blocking
726	waits otherwise.	830	waits otherwise.
727		831
…		…
733	=item $cb = $cv->cb ($cb->($cv))	837	=item $cb = $cv->cb ($cb->($cv))
734		838
735	This is a mutator function that returns the callback set and optionally	839	This is a mutator function that returns the callback set and optionally
736	replaces it before doing so.	840	replaces it before doing so.
737		841
738	The callback will be called when the condition becomes "true", i.e. when	842	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	843	"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	844	the only argument being the condition variable itself. Calling C<recv>
741	is guaranteed not to block.	845	inside the callback or at any later time is guaranteed not to block.
742		846
743	=back	847	=back
744		848
745	=head1 SUPPORTED EVENT LOOPS/BACKENDS	849	=head1 SUPPORTED EVENT LOOPS/BACKENDS
746		850
…		…
749	=over 4	853	=over 4
750		854
751	=item Backends that are autoprobed when no other event loop can be found.	855	=item Backends that are autoprobed when no other event loop can be found.
752		856
753	EV is the preferred backend when no other event loop seems to be in	857	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	858	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	859	pure-perl implementation, which is available everywhere as it comes with
756	available everywhere as it comes with AnyEvent itself.	860	AnyEvent itself.
757		861
758	AnyEvent::Impl::EV based on EV (interface to libev, best choice).	862	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.	863	AnyEvent::Impl::Perl pure-perl implementation, fast and portable.
761		864
762	=item Backends that are transparently being picked up when they are used.	865	=item Backends that are transparently being picked up when they are used.
763		866
764	These will be used when they are currently loaded when the first watcher	867	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	868	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	869	them. This means that AnyEvent will automatically pick the right backend
767	when the main program loads an event module before anything starts to	870	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.	871	create watchers. Nothing special needs to be done by the main program.
769		872
		873	AnyEvent::Impl::Event based on Event, very stable, few glitches.
770	AnyEvent::Impl::Glib based on Glib, slow but very stable.	874	AnyEvent::Impl::Glib based on Glib, slow but very stable.
771	AnyEvent::Impl::Tk based on Tk, very broken.	875	AnyEvent::Impl::Tk based on Tk, very broken.
772	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.	876	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
773	AnyEvent::Impl::POE based on POE, very slow, some limitations.	877	AnyEvent::Impl::POE based on POE, very slow, some limitations.
		878	AnyEvent::Impl::Irssi used when running within irssi.
774		879
775	=item Backends with special needs.	880	=item Backends with special needs.
776		881
777	Qt requires the Qt::Application to be instantiated first, but will	882	Qt requires the Qt::Application to be instantiated first, but will
778	otherwise be picked up automatically. As long as the main program	883	otherwise be picked up automatically. As long as the main program
…		…
852	event module detection too early, for example, L<AnyEvent::AIO> creates	957	event module detection too early, for example, L<AnyEvent::AIO> creates
853	and installs the global L<IO::AIO> watcher in a C<post_detect> block to	958	and installs the global L<IO::AIO> watcher in a C<post_detect> block to
854	avoid autodetecting the event module at load time.	959	avoid autodetecting the event module at load time.
855		960
856	If called in scalar or list context, then it creates and returns an object	961	If called in scalar or list context, then it creates and returns an object
857	that automatically removes the callback again when it is destroyed. See	962	that automatically removes the callback again when it is destroyed (or
		963	C<undef> when the hook was immediately executed). See L<AnyEvent::AIO> for
858	L<Coro::BDB> for a case where this is useful.	964	a case where this is useful.
		965
		966	Example: Create a watcher for the IO::AIO module and store it in
		967	C<$WATCHER>. Only do so after the event loop is initialised, though.
		968
		969	our WATCHER;
		970
		971	my $guard = AnyEvent::post_detect {
		972	$WATCHER = AnyEvent->io (fh => IO::AIO::poll_fileno, poll => 'r', cb => \&IO::AIO::poll_cb);
		973	};
		974
		975	# the ||= is important in case post_detect immediately runs the block,
		976	# as to not clobber the newly-created watcher. assigning both watcher and
		977	# post_detect guard to the same variable has the advantage of users being
		978	# able to just C<undef $WATCHER> if the watcher causes them grief.
		979
		980	$WATCHER ||= $guard;
859		981
860	=item @AnyEvent::post_detect	982	=item @AnyEvent::post_detect
861		983
862	If there are any code references in this array (you can C<push> to it	984	If there are any code references in this array (you can C<push> to it
863	before or after loading AnyEvent), then they will called directly after	985	before or after loading AnyEvent), then they will called directly after
…		…
866	You should check C<$AnyEvent::MODEL> before adding to this array, though:	988	You should check C<$AnyEvent::MODEL> before adding to this array, though:
867	if it is defined then the event loop has already been detected, and the	989	if it is defined then the event loop has already been detected, and the
868	array will be ignored.	990	array will be ignored.
869		991
870	Best use C<AnyEvent::post_detect { BLOCK }> when your application allows	992	Best use C<AnyEvent::post_detect { BLOCK }> when your application allows
871	it,as it takes care of these details.	993	it, as it takes care of these details.
872		994
873	This variable is mainly useful for modules that can do something useful	995	This variable is mainly useful for modules that can do something useful
874	when AnyEvent is used and thus want to know when it is initialised, but do	996	when AnyEvent is used and thus want to know when it is initialised, but do
875	not need to even load it by default. This array provides the means to hook	997	not need to even load it by default. This array provides the means to hook
876	into AnyEvent passively, without loading it.	998	into AnyEvent passively, without loading it.
		999
		1000	Example: To load Coro::AnyEvent whenever Coro and AnyEvent are used
		1001	together, you could put this into Coro (this is the actual code used by
		1002	Coro to accomplish this):
		1003
		1004	if (defined $AnyEvent::MODEL) {
		1005	# AnyEvent already initialised, so load Coro::AnyEvent
		1006	require Coro::AnyEvent;
		1007	} else {
		1008	# AnyEvent not yet initialised, so make sure to load Coro::AnyEvent
		1009	# as soon as it is
		1010	push @AnyEvent::post_detect, sub { require Coro::AnyEvent };
		1011	}
877		1012
878	=back	1013	=back
879		1014
880	=head1 WHAT TO DO IN A MODULE	1015	=head1 WHAT TO DO IN A MODULE
881		1016
…		…
938	=head1 OTHER MODULES	1073	=head1 OTHER MODULES
939		1074
940	The following is a non-exhaustive list of additional modules that use	1075	The following is a non-exhaustive list of additional modules that use
941	AnyEvent as a client and can therefore be mixed easily with other AnyEvent	1076	AnyEvent as a client and can therefore be mixed easily with other AnyEvent
942	modules and other event loops in the same program. Some of the modules	1077	modules and other event loops in the same program. Some of the modules
943	come with AnyEvent, most are available via CPAN.	1078	come as part of AnyEvent, the others are available via CPAN.
944		1079
945	=over 4	1080	=over 4
946		1081
947	=item L<AnyEvent::Util>	1082	=item L<AnyEvent::Util>
948		1083
…		…
963		1098
964	=item L<AnyEvent::DNS>	1099	=item L<AnyEvent::DNS>
965		1100
966	Provides rich asynchronous DNS resolver capabilities.	1101	Provides rich asynchronous DNS resolver capabilities.
967		1102
		1103	=item L<AnyEvent::HTTP>, L<AnyEvent::IRC>, L<AnyEvent::XMPP>, L<AnyEvent::GPSD>, L<AnyEvent::IGS>, L<AnyEvent::FCP>
		1104
		1105	Implement event-based interfaces to the protocols of the same name (for
		1106	the curious, IGS is the International Go Server and FCP is the Freenet
		1107	Client Protocol).
		1108
		1109	=item L<AnyEvent::Handle::UDP>
		1110
		1111	Here be danger!
		1112
		1113	As Pauli would put it, "Not only is it not right, it's not even wrong!" -
		1114	there are so many things wrong with AnyEvent::Handle::UDP, most notably
		1115	it's use of a stream-based API with a protocol that isn't streamable, that
		1116	the only way to improve it is to delete it.
		1117
		1118	It features data corruption (but typically only under load) and general
		1119	confusion. On top, the author is not only clueless about UDP but also
		1120	fact-resistant - some gems of his understanding: "connect doesn't work
		1121	with UDP", "UDP packets are not IP packets", "UDP only has datagrams, not
		1122	packets", "I don't need to implement proper error checking as UDP doesn't
		1123	support error checking" and so on - he doesn't even understand what's
		1124	wrong with his module when it is explained to him.
		1125
968	=item L<AnyEvent::HTTP>	1126	=item L<AnyEvent::DBI>
969		1127
970	A simple-to-use HTTP library that is capable of making a lot of concurrent	1128	Executes L<DBI> requests asynchronously in a proxy process for you,
971	HTTP requests.	1129	notifying you in an event-bnased way when the operation is finished.
		1130
		1131	=item L<AnyEvent::AIO>
		1132
		1133	Truly asynchronous (as opposed to non-blocking) I/O, should be in the
		1134	toolbox of every event programmer. AnyEvent::AIO transparently fuses
		1135	L<IO::AIO> and AnyEvent together, giving AnyEvent access to event-based
		1136	file I/O, and much more.
972		1137
973	=item L<AnyEvent::HTTPD>	1138	=item L<AnyEvent::HTTPD>
974		1139
975	Provides a simple web application server framework.	1140	A simple embedded webserver.
976		1141
977	=item L<AnyEvent::FastPing>	1142	=item L<AnyEvent::FastPing>
978		1143
979	The fastest ping in the west.	1144	The fastest ping in the west.
980		1145
981	=item L<AnyEvent::DBI>
982
983	Executes L<DBI> requests asynchronously in a proxy process.
984
985	=item L<AnyEvent::AIO>
986
987	Truly asynchronous I/O, should be in the toolbox of every event
988	programmer. AnyEvent::AIO transparently fuses L<IO::AIO> and AnyEvent
989	together.
990
991	=item L<AnyEvent::BDB>
992
993	Truly asynchronous Berkeley DB access. AnyEvent::BDB transparently fuses
994	L<BDB> and AnyEvent together.
995
996	=item L<AnyEvent::GPSD>
997
998	A non-blocking interface to gpsd, a daemon delivering GPS information.
999
1000	=item L<AnyEvent::IRC>
1001
1002	AnyEvent based IRC client module family (replacing the older Net::IRC3).
1003
1004	=item L<AnyEvent::XMPP>
1005
1006	AnyEvent based XMPP (Jabber protocol) module family (replacing the older
1007	Net::XMPP2>.
1008
1009	=item L<AnyEvent::IGS>
1010
1011	A non-blocking interface to the Internet Go Server protocol (used by
1012	L<App::IGS>).
1013
1014	=item L<Net::FCP>
1015
1016	AnyEvent-based implementation of the Freenet Client Protocol, birthplace
1017	of AnyEvent.
1018
1019	=item L<Event::ExecFlow>
1020
1021	High level API for event-based execution flow control.
1022
1023	=item L<Coro>	1146	=item L<Coro>
1024		1147
1025	Has special support for AnyEvent via L<Coro::AnyEvent>.	1148	Has special support for AnyEvent via L<Coro::AnyEvent>.
1026		1149
1027	=back	1150	=back
1028		1151
1029	=cut	1152	=cut
1030		1153
1031	package AnyEvent;	1154	package AnyEvent;
1032		1155
1033	no warnings;	1156	# basically a tuned-down version of common::sense
1034	use strict qw(vars subs);	1157	sub common_sense {
		1158	# from common:.sense 1.0
		1159	${^WARNING_BITS} = "\xfc\x3f\x33\x00\x0f\xf3\xcf\xc0\xf3\xfc\x33\x00";
		1160	# use strict vars subs - NO UTF-8, as Util.pm doesn't like this atm. (uts46data.pl)
		1161	$^H |= 0x00000600;
		1162	}
1035		1163
		1164	BEGIN { AnyEvent::common_sense }
		1165
1036	use Carp;	1166	use Carp ();
1037		1167
1038	our $VERSION = 4.81;	1168	our $VERSION = '5.261';
1039	our $MODEL;	1169	our $MODEL;
1040		1170
1041	our $AUTOLOAD;	1171	our $AUTOLOAD;
1042	our @ISA;	1172	our @ISA;
1043		1173
1044	our @REGISTRY;	1174	our @REGISTRY;
1045		1175
1046	our $WIN32;	1176	our $VERBOSE;
1047		1177
1048	BEGIN {	1178	BEGIN {
1049	eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }";	1179	require "AnyEvent/constants.pl";
		1180
1050	eval "sub TAINT(){ " . (${^TAINT}*1) . " }";	1181	eval "sub TAINT (){" . (${^TAINT}*1) . "}";
1051		1182
1052	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}	1183	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}
1053	if ${^TAINT};	1184	if ${^TAINT};
1054	}
1055		1185
1056	our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1;	1186	$VERBOSE = $ENV{PERL_ANYEVENT_VERBOSE}*1;
		1187
		1188	}
		1189
		1190	our $MAX_SIGNAL_LATENCY = 10;
1057		1191
1058	our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred	1192	our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred
1059		1193
1060	{	1194	{
1061	my $idx;	1195	my $idx;
…		…
1063	for reverse split /\s*,\s*/,	1197	for reverse split /\s*,\s*/,
1064	$ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";	1198	$ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";
1065	}	1199	}
1066		1200
1067	my @models = (	1201	my @models = (
1068	[EV:: => AnyEvent::Impl::EV::],	1202	[EV:: => AnyEvent::Impl::EV:: , 1],
1069	[Event:: => AnyEvent::Impl::Event::],
1070	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::],	1203	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl:: , 1],
1071	# everything below here will not be autoprobed	1204	# everything below here will not (normally) be autoprobed
1072	# as the pureperl backend should work everywhere	1205	# as the pureperl backend should work everywhere
1073	# and is usually faster	1206	# and is usually faster
		1207	[Event:: => AnyEvent::Impl::Event::, 1],
1074	[Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers	1208	[Glib:: => AnyEvent::Impl::Glib:: , 1], # becomes extremely slow with many watchers
1075	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy	1209	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
		1210	[Irssi:: => AnyEvent::Impl::Irssi::], # Irssi has a bogus "Event" package
1076	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles	1211	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
		1212	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program
1077	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza	1213	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
1078	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program
1079	[Wx:: => AnyEvent::Impl::POE::],	1214	[Wx:: => AnyEvent::Impl::POE::],
1080	[Prima:: => AnyEvent::Impl::POE::],	1215	[Prima:: => AnyEvent::Impl::POE::],
1081	# IO::Async is just too broken - we would need workarounds for its	1216	# IO::Async is just too broken - we would need workarounds for its
1082	# byzantine signal and broken child handling, among others.	1217	# byzantine signal and broken child handling, among others.
1083	# IO::Async is rather hard to detect, as it doesn't have any	1218	# IO::Async is rather hard to detect, as it doesn't have any
1084	# obvious default class.	1219	# obvious default class.
1085	# [IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program	1220	[IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program
1086	# [IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program	1221	[IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program
1087	# [IO::Async::Notifier:: => AnyEvent::Impl::IOAsync::], # requires special main program	1222	[IO::Async::Notifier:: => AnyEvent::Impl::IOAsync::], # requires special main program
		1223	[AnyEvent::Impl::IOAsync:: => AnyEvent::Impl::IOAsync::], # requires special main program
1088	);	1224	);
1089		1225
1090	our %method = map +($_ => 1),	1226	our %method = map +($_ => 1),
1091	qw(io timer time now now_update signal child idle condvar one_event DESTROY);	1227	qw(io timer time now now_update signal child idle condvar one_event DESTROY);
1092		1228
1093	our @post_detect;	1229	our @post_detect;
1094		1230
1095	sub post_detect(&) {	1231	sub post_detect(&) {
1096	my ($cb) = @_;	1232	my ($cb) = @_;
1097		1233
1098	if ($MODEL) {
1099	$cb->();
1100
1101	1
1102	} else {
1103	push @post_detect, $cb;	1234	push @post_detect, $cb;
1104		1235
1105	defined wantarray	1236	defined wantarray
1106	? bless \$cb, "AnyEvent::Util::postdetect"	1237	? bless \$cb, "AnyEvent::Util::postdetect"
1107	: ()	1238	: ()
1108	}
1109	}	1239	}
1110		1240
1111	sub AnyEvent::Util::postdetect::DESTROY {	1241	sub AnyEvent::Util::postdetect::DESTROY {
1112	@post_detect = grep $_ != ${$_[0]}, @post_detect;	1242	@post_detect = grep $_ != ${$_[0]}, @post_detect;
1113	}	1243	}
1114		1244
1115	sub detect() {	1245	sub detect() {
		1246	# free some memory
		1247	*detect = sub () { $MODEL };
		1248
		1249	local $!; # for good measure
		1250	local $SIG{__DIE__};
		1251
		1252	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {
		1253	my $model = "AnyEvent::Impl::$1";
		1254	if (eval "require $model") {
		1255	$MODEL = $model;
		1256	warn "AnyEvent: loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.\n" if $VERBOSE >= 2;
		1257	} else {
		1258	warn "AnyEvent: unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@" if $VERBOSE;
		1259	}
		1260	}
		1261
		1262	# check for already loaded models
1116	unless ($MODEL) {	1263	unless ($MODEL) {
1117	no strict 'refs';	1264	for (@REGISTRY, @models) {
1118	local $SIG{__DIE__};	1265	my ($package, $model) = @$_;
1119		1266	if (${"$package\::VERSION"} > 0) {
1120	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {
1121	my $model = "AnyEvent::Impl::$1";
1122	if (eval "require $model") {	1267	if (eval "require $model") {
1123	$MODEL = $model;	1268	$MODEL = $model;
1124	warn "AnyEvent: loaded model '$model' (forced by \$PERL_ANYEVENT_MODEL), using it.\n" if $verbose > 1;	1269	warn "AnyEvent: autodetected model '$model', using it.\n" if $VERBOSE >= 2;
1125	} else {	1270	last;
1126	warn "AnyEvent: unable to load model '$model' (from \$PERL_ANYEVENT_MODEL):\n$@" if $verbose;	1271	}
1127	}	1272	}
1128	}	1273	}
1129		1274
1130	# check for already loaded models
1131	unless ($MODEL) {	1275	unless ($MODEL) {
		1276	# try to autoload a model
1132	for (@REGISTRY, @models) {	1277	for (@REGISTRY, @models) {
1133	my ($package, $model) = @$_;	1278	my ($package, $model, $autoload) = @$_;
		1279	if (
		1280	$autoload
		1281	and eval "require $package"
1134	if (${"$package\::VERSION"} > 0) {	1282	and ${"$package\::VERSION"} > 0
1135	if (eval "require $model") {	1283	and eval "require $model"
		1284	) {
1136	$MODEL = $model;	1285	$MODEL = $model;
1137	warn "AnyEvent: autodetected model '$model', using it.\n" if $verbose > 1;	1286	warn "AnyEvent: autoloaded model '$model', using it.\n" if $VERBOSE >= 2;
1138	last;	1287	last;
1139	}
1140	}	1288	}
1141	}	1289	}
1142		1290
1143	unless ($MODEL) {
1144	# try to load a model
1145
1146	for (@REGISTRY, @models) {
1147	my ($package, $model) = @$_;
1148	if (eval "require $package"
1149	and ${"$package\::VERSION"} > 0
1150	and eval "require $model") {
1151	$MODEL = $model;
1152	warn "AnyEvent: autoprobed model '$model', using it.\n" if $verbose > 1;
1153	last;
1154	}
1155	}
1156
1157	$MODEL	1291	$MODEL
1158	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.\n";	1292	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.\n";
1159	}
1160	}	1293	}
1161
1162	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
1163
1164	unshift @ISA, $MODEL;
1165
1166	require AnyEvent::Strict if $ENV{PERL_ANYEVENT_STRICT};
1167
1168	(shift @post_detect)->() while @post_detect;
1169	}	1294	}
		1295
		1296	@models = (); # free probe data
		1297
		1298	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
		1299	unshift @ISA, $MODEL;
		1300
		1301	# now nuke some methods that are overriden by the backend.
		1302	# SUPER is not allowed.
		1303	for (qw(time signal child idle)) {
		1304	undef &{"AnyEvent::Base::$_"}
		1305	if defined &{"$MODEL\::$_"};
		1306	}
		1307
		1308	require AnyEvent::Strict if $ENV{PERL_ANYEVENT_STRICT};
		1309
		1310	(shift @post_detect)->() while @post_detect;
		1311
		1312	*post_detect = sub(&) {
		1313	shift->();
		1314
		1315	undef
		1316	};
1170		1317
1171	$MODEL	1318	$MODEL
1172	}	1319	}
1173		1320
1174	sub AUTOLOAD {	1321	sub AUTOLOAD {
1175	(my $func = $AUTOLOAD) =~ s/.*://;	1322	(my $func = $AUTOLOAD) =~ s/.*://;
1176		1323
1177	$method{$func}	1324	$method{$func}
1178	or croak "$func: not a valid method for AnyEvent objects";	1325	or Carp::croak "$func: not a valid AnyEvent class method";
1179		1326
1180	detect unless $MODEL;	1327	detect;
1181		1328
1182	my $class = shift;	1329	my $class = shift;
1183	$class->$func (@_);	1330	$class->$func (@_);
1184	}	1331	}
1185		1332
…		…
1188	# allow only one watcher per fd, so we dup it to get a different one).	1335	# allow only one watcher per fd, so we dup it to get a different one).
1189	sub _dupfh($$;$$) {	1336	sub _dupfh($$;$$) {
1190	my ($poll, $fh, $r, $w) = @_;	1337	my ($poll, $fh, $r, $w) = @_;
1191		1338
1192	# cygwin requires the fh mode to be matching, unix doesn't	1339	# cygwin requires the fh mode to be matching, unix doesn't
1193	my ($rw, $mode) = $poll eq "r" ? ($r, "<") : ($w, ">");	1340	my ($rw, $mode) = $poll eq "r" ? ($r, "<&") : ($w, ">&");
1194		1341
1195	open my $fh2, "$mode&", $fh	1342	open my $fh2, $mode, $fh
1196	or die "AnyEvent->io: cannot dup() filehandle in mode '$poll': $!,";	1343	or die "AnyEvent->io: cannot dup() filehandle in mode '$poll': $!,";
1197		1344
1198	# we assume CLOEXEC is already set by perl in all important cases	1345	# we assume CLOEXEC is already set by perl in all important cases
1199		1346
1200	($fh2, $rw)	1347	($fh2, $rw)
1201	}	1348	}
1202		1349
		1350	=head1 SIMPLIFIED AE API
		1351
		1352	Starting with version 5.0, AnyEvent officially supports a second, much
		1353	simpler, API that is designed to reduce the calling, typing and memory
		1354	overhead by using function call syntax and a fixed number of parameters.
		1355
		1356	See the L<AE> manpage for details.
		1357
		1358	=cut
		1359
		1360	package AE;
		1361
		1362	our $VERSION = $AnyEvent::VERSION;
		1363
		1364	# fall back to the main API by default - backends and AnyEvent::Base
		1365	# implementations can overwrite these.
		1366
		1367	sub io($$$) {
		1368	AnyEvent->io (fh => $_[0], poll => $_[1] ? "w" : "r", cb => $_[2])
		1369	}
		1370
		1371	sub timer($$$) {
		1372	AnyEvent->timer (after => $_[0], interval => $_[1], cb => $_[2])
		1373	}
		1374
		1375	sub signal($$) {
		1376	AnyEvent->signal (signal => $_[0], cb => $_[1])
		1377	}
		1378
		1379	sub child($$) {
		1380	AnyEvent->child (pid => $_[0], cb => $_[1])
		1381	}
		1382
		1383	sub idle($) {
		1384	AnyEvent->idle (cb => $_[0])
		1385	}
		1386
		1387	sub cv(;&) {
		1388	AnyEvent->condvar (@_ ? (cb => $_[0]) : ())
		1389	}
		1390
		1391	sub now() {
		1392	AnyEvent->now
		1393	}
		1394
		1395	sub now_update() {
		1396	AnyEvent->now_update
		1397	}
		1398
		1399	sub time() {
		1400	AnyEvent->time
		1401	}
		1402
1203	package AnyEvent::Base;	1403	package AnyEvent::Base;
1204		1404
1205	# default implementations for many methods	1405	# default implementations for many methods
1206		1406
1207	BEGIN {	1407	sub time {
		1408	eval q{ # poor man's autoloading {}
		1409	# probe for availability of Time::HiRes
1208	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {	1410	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {
		1411	warn "AnyEvent: using Time::HiRes for sub-second timing accuracy.\n" if $VERBOSE >= 8;
1209	*_time = \&Time::HiRes::time;	1412	*AE::time = \&Time::HiRes::time;
1210	# if (eval "use POSIX (); (POSIX::times())...	1413	# if (eval "use POSIX (); (POSIX::times())...
1211	} else {	1414	} else {
		1415	warn "AnyEvent: using built-in time(), WARNING, no sub-second resolution!\n" if $VERBOSE;
1212	*_time = sub { time }; # epic fail	1416	*AE::time = sub (){ time }; # epic fail
		1417	}
		1418
		1419	*time = sub { AE::time }; # different prototypes
		1420	};
		1421	die if $@;
		1422
		1423	&time
		1424	}
		1425
		1426	*now = \&time;
		1427
		1428	sub now_update { }
		1429
		1430	# default implementation for ->condvar
		1431
		1432	sub condvar {
		1433	eval q{ # poor man's autoloading {}
		1434	*condvar = sub {
		1435	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"
		1436	};
		1437
		1438	*AE::cv = sub (;&) {
		1439	bless { @_ ? (_ae_cb => shift) : () }, "AnyEvent::CondVar"
		1440	};
		1441	};
		1442	die if $@;
		1443
		1444	&condvar
		1445	}
		1446
		1447	# default implementation for ->signal
		1448
		1449	our $HAVE_ASYNC_INTERRUPT;
		1450
		1451	sub _have_async_interrupt() {
		1452	$HAVE_ASYNC_INTERRUPT = 1*(!$ENV{PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT}
		1453	&& eval "use Async::Interrupt 1.02 (); 1")
		1454	unless defined $HAVE_ASYNC_INTERRUPT;
		1455
		1456	$HAVE_ASYNC_INTERRUPT
		1457	}
		1458
		1459	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);
		1460	our (%SIG_ASY, %SIG_ASY_W);
		1461	our ($SIG_COUNT, $SIG_TW);
		1462
		1463	# install a dummy wakeup watcher to reduce signal catching latency
		1464	# used by Impls
		1465	sub _sig_add() {
		1466	unless ($SIG_COUNT++) {
		1467	# try to align timer on a full-second boundary, if possible
		1468	my $NOW = AE::now;
		1469
		1470	$SIG_TW = AE::timer
		1471	$MAX_SIGNAL_LATENCY - ($NOW - int $NOW),
		1472	$MAX_SIGNAL_LATENCY,
		1473	sub { } # just for the PERL_ASYNC_CHECK
		1474	;
1213	}	1475	}
1214	}	1476	}
1215		1477
1216	sub time { _time }	1478	sub _sig_del {
1217	sub now { _time }	1479	undef $SIG_TW
1218	sub now_update { }	1480	unless --$SIG_COUNT;
1219
1220	# default implementation for ->condvar
1221
1222	sub condvar {
1223	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"
1224	}	1481	}
1225		1482
1226	# default implementation for ->signal	1483	our $_sig_name_init; $_sig_name_init = sub {
		1484	eval q{ # poor man's autoloading {}
		1485	undef $_sig_name_init;
1227		1486
1228	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);	1487	if (_have_async_interrupt) {
		1488	*sig2num = \&Async::Interrupt::sig2num;
		1489	*sig2name = \&Async::Interrupt::sig2name;
		1490	} else {
		1491	require Config;
1229		1492
1230	sub _signal_exec {	1493	my %signame2num;
1231	sysread $SIGPIPE_R, my $dummy, 4;	1494	@signame2num{ split ' ', $Config::Config{sig_name} }
		1495	= split ' ', $Config::Config{sig_num};
1232		1496
1233	while (%SIG_EV) {	1497	my @signum2name;
1234	for (keys %SIG_EV) {	1498	@signum2name[values %signame2num] = keys %signame2num;
1235	delete $SIG_EV{$_};	1499
1236	$_->() for values %{ $SIG_CB{$_} || {} };	1500	*sig2num = sub($) {
		1501	$_[0] > 0 ? shift : $signame2num{+shift}
		1502	};
		1503	*sig2name = sub ($) {
		1504	$_[0] > 0 ? $signum2name[+shift] : shift
		1505	};
1237	}	1506	}
1238	}	1507	};
1239	}	1508	die if $@;
		1509	};
		1510
		1511	sub sig2num ($) { &$_sig_name_init; &sig2num }
		1512	sub sig2name($) { &$_sig_name_init; &sig2name }
1240		1513
1241	sub signal {	1514	sub signal {
1242	my (undef, %arg) = @_;	1515	eval q{ # poor man's autoloading {}
		1516	# probe for availability of Async::Interrupt
		1517	if (_have_async_interrupt) {
		1518	warn "AnyEvent: using Async::Interrupt for race-free signal handling.\n" if $VERBOSE >= 8;
1243		1519
1244	unless ($SIGPIPE_R) {	1520	$SIGPIPE_R = new Async::Interrupt::EventPipe;
1245	require Fcntl;	1521	$SIG_IO = AE::io $SIGPIPE_R->fileno, 0, \&_signal_exec;
1246		1522
1247	if (AnyEvent::WIN32) {
1248	require AnyEvent::Util;
1249
1250	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
1251	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R) if $SIGPIPE_R;
1252	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W) if $SIGPIPE_W; # just in case
1253	} else {	1523	} else {
		1524	warn "AnyEvent: using emulated perl signal handling with latency timer.\n" if $VERBOSE >= 8;
		1525
		1526	if (AnyEvent::WIN32) {
		1527	require AnyEvent::Util;
		1528
		1529	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
		1530	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R, 1) if $SIGPIPE_R;
		1531	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W, 1) if $SIGPIPE_W; # just in case
		1532	} else {
1254	pipe $SIGPIPE_R, $SIGPIPE_W;	1533	pipe $SIGPIPE_R, $SIGPIPE_W;
1255	fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R;	1534	fcntl $SIGPIPE_R, AnyEvent::F_SETFL, AnyEvent::O_NONBLOCK if $SIGPIPE_R;
1256	fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case	1535	fcntl $SIGPIPE_W, AnyEvent::F_SETFL, AnyEvent::O_NONBLOCK if $SIGPIPE_W; # just in case
1257		1536
1258	# not strictly required, as $^F is normally 2, but let's make sure...	1537	# not strictly required, as $^F is normally 2, but let's make sure...
1259	fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;	1538	fcntl $SIGPIPE_R, AnyEvent::F_SETFD, AnyEvent::FD_CLOEXEC;
1260	fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;	1539	fcntl $SIGPIPE_W, AnyEvent::F_SETFD, AnyEvent::FD_CLOEXEC;
		1540	}
		1541
		1542	$SIGPIPE_R
		1543	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";
		1544
		1545	$SIG_IO = AE::io $SIGPIPE_R, 0, \&_signal_exec;
1261	}	1546	}
1262		1547
1263	$SIGPIPE_R	1548	*signal = $HAVE_ASYNC_INTERRUPT
1264	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";	1549	? sub {
		1550	my (undef, %arg) = @_;
1265		1551
1266	$SIG_IO = AnyEvent->io (fh => $SIGPIPE_R, poll => "r", cb => \&_signal_exec);	1552	# async::interrupt
1267	}
1268
1269	my $signal = uc $arg{signal}	1553	my $signal = sig2num $arg{signal};
1270	or Carp::croak "required option 'signal' is missing";
1271
1272	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};	1554	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
		1555
		1556	$SIG_ASY{$signal} ||= new Async::Interrupt
		1557	cb => sub { undef $SIG_EV{$signal} },
		1558	signal => $signal,
		1559	pipe => [$SIGPIPE_R->filenos],
		1560	pipe_autodrain => 0,
		1561	;
		1562
		1563	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
		1564	}
		1565	: sub {
		1566	my (undef, %arg) = @_;
		1567
		1568	# pure perl
		1569	my $signal = sig2name $arg{signal};
		1570	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
		1571
1273	$SIG{$signal} ||= sub {	1572	$SIG{$signal} ||= sub {
1274	local $!;	1573	local $!;
1275	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;	1574	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;
1276	undef $SIG_EV{$signal};	1575	undef $SIG_EV{$signal};
		1576	};
		1577
		1578	# can't do signal processing without introducing races in pure perl,
		1579	# so limit the signal latency.
		1580	_sig_add;
		1581
		1582	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
		1583	}
		1584	;
		1585
		1586	*AnyEvent::Base::signal::DESTROY = sub {
		1587	my ($signal, $cb) = @{$_[0]};
		1588
		1589	_sig_del;
		1590
		1591	delete $SIG_CB{$signal}{$cb};
		1592
		1593	$HAVE_ASYNC_INTERRUPT
		1594	? delete $SIG_ASY{$signal}
		1595	: # delete doesn't work with older perls - they then
		1596	# print weird messages, or just unconditionally exit
		1597	# instead of getting the default action.
		1598	undef $SIG{$signal}
		1599	unless keys %{ $SIG_CB{$signal} };
		1600	};
		1601
		1602	*_signal_exec = sub {
		1603	$HAVE_ASYNC_INTERRUPT
		1604	? $SIGPIPE_R->drain
		1605	: sysread $SIGPIPE_R, (my $dummy), 9;
		1606
		1607	while (%SIG_EV) {
		1608	for (keys %SIG_EV) {
		1609	delete $SIG_EV{$_};
		1610	$_->() for values %{ $SIG_CB{$_} || {} };
		1611	}
		1612	}
		1613	};
1277	};	1614	};
		1615	die if $@;
1278		1616
1279	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"	1617	&signal
1280	}
1281
1282	sub AnyEvent::Base::signal::DESTROY {
1283	my ($signal, $cb) = @{$_[0]};
1284
1285	delete $SIG_CB{$signal}{$cb};
1286
1287	# delete doesn't work with older perls - they then
1288	# print weird messages, or just unconditionally exit
1289	# instead of getting the default action.
1290	undef $SIG{$signal} unless keys %{ $SIG_CB{$signal} };
1291	}	1618	}
1292		1619
1293	# default implementation for ->child	1620	# default implementation for ->child
1294		1621
1295	our %PID_CB;	1622	our %PID_CB;
1296	our $CHLD_W;	1623	our $CHLD_W;
1297	our $CHLD_DELAY_W;	1624	our $CHLD_DELAY_W;
1298	our $WNOHANG;	1625	our $WNOHANG;
1299		1626
1300	sub _sigchld {	1627	# used by many Impl's
1301	while (0 < (my $pid = waitpid -1, $WNOHANG)) {	1628	sub _emit_childstatus($$) {
		1629	my (undef, $rpid, $rstatus) = @_;
		1630
		1631	$_->($rpid, $rstatus)
1302	$_->($pid, $?) for (values %{ $PID_CB{$pid} || {} }),	1632	for values %{ $PID_CB{$rpid} || {} },
1303	(values %{ $PID_CB{0} || {} });	1633	values %{ $PID_CB{0} || {} };
1304	}
1305	}	1634	}
1306		1635
1307	sub child {	1636	sub child {
		1637	eval q{ # poor man's autoloading {}
		1638	*_sigchld = sub {
		1639	my $pid;
		1640
		1641	AnyEvent->_emit_childstatus ($pid, $?)
		1642	while ($pid = waitpid -1, $WNOHANG) > 0;
		1643	};
		1644
		1645	*child = sub {
1308	my (undef, %arg) = @_;	1646	my (undef, %arg) = @_;
1309		1647
1310	defined (my $pid = $arg{pid} + 0)	1648	defined (my $pid = $arg{pid} + 0)
1311	or Carp::croak "required option 'pid' is missing";	1649	or Carp::croak "required option 'pid' is missing";
1312		1650
1313	$PID_CB{$pid}{$arg{cb}} = $arg{cb};	1651	$PID_CB{$pid}{$arg{cb}} = $arg{cb};
1314		1652
		1653	# WNOHANG is almost cetrainly 1 everywhere
		1654	$WNOHANG ||= $^O =~ /^(?:openbsd|netbsd|linux|freebsd|cygwin|MSWin32)$/
		1655	? 1
1315	$WNOHANG ||= eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1;	1656	: eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1;
1316		1657
1317	unless ($CHLD_W) {	1658	unless ($CHLD_W) {
1318	$CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld);	1659	$CHLD_W = AE::signal CHLD => \&_sigchld;
1319	# child could be a zombie already, so make at least one round	1660	# child could be a zombie already, so make at least one round
1320	&_sigchld;	1661	&_sigchld;
1321	}	1662	}
1322		1663
1323	bless [$pid, $arg{cb}], "AnyEvent::Base::child"	1664	bless [$pid, $arg{cb}], "AnyEvent::Base::child"
1324	}	1665	};
1325		1666
1326	sub AnyEvent::Base::child::DESTROY {	1667	*AnyEvent::Base::child::DESTROY = sub {
1327	my ($pid, $cb) = @{$_[0]};	1668	my ($pid, $cb) = @{$_[0]};
1328		1669
1329	delete $PID_CB{$pid}{$cb};	1670	delete $PID_CB{$pid}{$cb};
1330	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };	1671	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };
1331		1672
1332	undef $CHLD_W unless keys %PID_CB;	1673	undef $CHLD_W unless keys %PID_CB;
		1674	};
		1675	};
		1676	die if $@;
		1677
		1678	&child
1333	}	1679	}
1334		1680
1335	# idle emulation is done by simply using a timer, regardless	1681	# idle emulation is done by simply using a timer, regardless
1336	# of whether the process is idle or not, and not letting	1682	# of whether the process is idle or not, and not letting
1337	# the callback use more than 50% of the time.	1683	# the callback use more than 50% of the time.
1338	sub idle {	1684	sub idle {
		1685	eval q{ # poor man's autoloading {}
		1686	*idle = sub {
1339	my (undef, %arg) = @_;	1687	my (undef, %arg) = @_;
1340		1688
1341	my ($cb, $w, $rcb) = $arg{cb};	1689	my ($cb, $w, $rcb) = $arg{cb};
1342		1690
1343	$rcb = sub {	1691	$rcb = sub {
1344	if ($cb) {	1692	if ($cb) {
1345	$w = _time;	1693	$w = _time;
1346	&$cb;	1694	&$cb;
1347	$w = _time - $w;	1695	$w = _time - $w;
1348		1696
1349	# never use more then 50% of the time for the idle watcher,	1697	# never use more then 50% of the time for the idle watcher,
1350	# within some limits	1698	# within some limits
1351	$w = 0.0001 if $w < 0.0001;	1699	$w = 0.0001 if $w < 0.0001;
1352	$w = 5 if $w > 5;	1700	$w = 5 if $w > 5;
1353		1701
1354	$w = AnyEvent->timer (after => $w, cb => $rcb);	1702	$w = AE::timer $w, 0, $rcb;
1355	} else {	1703	} else {
1356	# clean up...	1704	# clean up...
1357	undef $w;	1705	undef $w;
1358	undef $rcb;	1706	undef $rcb;
		1707	}
		1708	};
		1709
		1710	$w = AE::timer 0.05, 0, $rcb;
		1711
		1712	bless \\$cb, "AnyEvent::Base::idle"
1359	}	1713	};
		1714
		1715	*AnyEvent::Base::idle::DESTROY = sub {
		1716	undef $${$_[0]};
		1717	};
1360	};	1718	};
		1719	die if $@;
1361		1720
1362	$w = AnyEvent->timer (after => 0.05, cb => $rcb);	1721	&idle
1363
1364	bless \\$cb, "AnyEvent::Base::idle"
1365	}
1366
1367	sub AnyEvent::Base::idle::DESTROY {
1368	undef $${$_[0]};
1369	}	1722	}
1370		1723
1371	package AnyEvent::CondVar;	1724	package AnyEvent::CondVar;
1372		1725
1373	our @ISA = AnyEvent::CondVar::Base::;	1726	our @ISA = AnyEvent::CondVar::Base::;
1374		1727
1375	package AnyEvent::CondVar::Base;	1728	package AnyEvent::CondVar::Base;
1376		1729
1377	use overload	1730	#use overload
1378	'&{}' => sub { my $self = shift; sub { $self->send (@_) } },	1731	# '&{}' => sub { my $self = shift; sub { $self->send (@_) } },
1379	fallback => 1;	1732	# fallback => 1;
		1733
		1734	# save 300+ kilobytes by dirtily hardcoding overloading
		1735	${"AnyEvent::CondVar::Base::OVERLOAD"}{dummy}++; # Register with magic by touching.
		1736	*{'AnyEvent::CondVar::Base::()'} = sub { }; # "Make it findable via fetchmethod."
		1737	*{'AnyEvent::CondVar::Base::(&{}'} = sub { my $self = shift; sub { $self->send (@_) } }; # &{}
		1738	${'AnyEvent::CondVar::Base::()'} = 1; # fallback
		1739
		1740	our $WAITING;
1380		1741
1381	sub _send {	1742	sub _send {
1382	# nop	1743	# nop
1383	}	1744	}
1384		1745
…		…
1397	sub ready {	1758	sub ready {
1398	$_[0]{_ae_sent}	1759	$_[0]{_ae_sent}
1399	}	1760	}
1400		1761
1401	sub _wait {	1762	sub _wait {
		1763	$WAITING
		1764	and !$_[0]{_ae_sent}
		1765	and Carp::croak "AnyEvent::CondVar: recursive blocking wait detected";
		1766
		1767	local $WAITING = 1;
1402	AnyEvent->one_event while !$_[0]{_ae_sent};	1768	AnyEvent->one_event while !$_[0]{_ae_sent};
1403	}	1769	}
1404		1770
1405	sub recv {	1771	sub recv {
1406	$_[0]->_wait;	1772	$_[0]->_wait;
…		…
1408	Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak};	1774	Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak};
1409	wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0]	1775	wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0]
1410	}	1776	}
1411		1777
1412	sub cb {	1778	sub cb {
1413	$_[0]{_ae_cb} = $_[1] if @_ > 1;	1779	my $cv = shift;
		1780
		1781	@_
		1782	and $cv->{_ae_cb} = shift
		1783	and $cv->{_ae_sent}
		1784	and (delete $cv->{_ae_cb})->($cv);
		1785
1414	$_[0]{_ae_cb}	1786	$cv->{_ae_cb}
1415	}	1787	}
1416		1788
1417	sub begin {	1789	sub begin {
1418	++$_[0]{_ae_counter};	1790	++$_[0]{_ae_counter};
1419	$_[0]{_ae_end_cb} = $_[1] if @_ > 1;	1791	$_[0]{_ae_end_cb} = $_[1] if @_ > 1;
…		…
1468	C<PERL_ANYEVENT_MODEL>.	1840	C<PERL_ANYEVENT_MODEL>.
1469		1841
1470	When set to C<2> or higher, cause AnyEvent to report to STDERR which event	1842	When set to C<2> or higher, cause AnyEvent to report to STDERR which event
1471	model it chooses.	1843	model it chooses.
1472		1844
		1845	When set to C<8> or higher, then AnyEvent will report extra information on
		1846	which optional modules it loads and how it implements certain features.
		1847
1473	=item C<PERL_ANYEVENT_STRICT>	1848	=item C<PERL_ANYEVENT_STRICT>
1474		1849
1475	AnyEvent does not do much argument checking by default, as thorough	1850	AnyEvent does not do much argument checking by default, as thorough
1476	argument checking is very costly. Setting this variable to a true value	1851	argument checking is very costly. Setting this variable to a true value
1477	will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly	1852	will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly
1478	check the arguments passed to most method calls. If it finds any problems,	1853	check the arguments passed to most method calls. If it finds any problems,
1479	it will croak.	1854	it will croak.
1480		1855
1481	In other words, enables "strict" mode.	1856	In other words, enables "strict" mode.
1482		1857
1483	Unlike C<use strict>, it is definitely recommended to keep it off in	1858	Unlike C<use strict> (or it's modern cousin, C<< use L<common::sense>
1484	production. Keeping C<PERL_ANYEVENT_STRICT=1> in your environment while	1859	>>, it is definitely recommended to keep it off in production. Keeping
1485	developing programs can be very useful, however.	1860	C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs
		1861	can be very useful, however.
1486		1862
1487	=item C<PERL_ANYEVENT_MODEL>	1863	=item C<PERL_ANYEVENT_MODEL>
1488		1864
1489	This can be used to specify the event model to be used by AnyEvent, before	1865	This can be used to specify the event model to be used by AnyEvent, before
1490	auto detection and -probing kicks in. It must be a string consisting	1866	auto detection and -probing kicks in. It must be a string consisting
…		…
1552		1928
1553	When neither C<ca_file> nor C<ca_path> was specified during	1929	When neither C<ca_file> nor C<ca_path> was specified during
1554	L<AnyEvent::TLS> context creation, and either of these environment	1930	L<AnyEvent::TLS> context creation, and either of these environment
1555	variables exist, they will be used to specify CA certificate locations	1931	variables exist, they will be used to specify CA certificate locations
1556	instead of a system-dependent default.	1932	instead of a system-dependent default.
		1933
		1934	=item C<PERL_ANYEVENT_AVOID_GUARD> and C<PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT>
		1935
		1936	When these are set to C<1>, then the respective modules are not
		1937	loaded. Mostly good for testing AnyEvent itself.
1557		1938
1558	=back	1939	=back
1559		1940
1560	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE	1941	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE
1561		1942
…		…
1619	warn "read: $input\n"; # output what has been read	2000	warn "read: $input\n"; # output what has been read
1620	$cv->send if $input =~ /^q/i; # quit program if /^q/i	2001	$cv->send if $input =~ /^q/i; # quit program if /^q/i
1621	},	2002	},
1622	);	2003	);
1623		2004
1624	my $time_watcher; # can only be used once
1625
1626	sub new_timer {
1627	$timer = AnyEvent->timer (after => 1, cb => sub {	2005	my $time_watcher = AnyEvent->timer (after => 1, interval => 1, cb => sub {
1628	warn "timeout\n"; # print 'timeout' about every second	2006	warn "timeout\n"; # print 'timeout' at most every second
1629	&new_timer; # and restart the time
1630	});	2007	});
1631	}
1632
1633	new_timer; # create first timer
1634		2008
1635	$cv->recv; # wait until user enters /^q/i	2009	$cv->recv; # wait until user enters /^q/i
1636		2010
1637	=head1 REAL-WORLD EXAMPLE	2011	=head1 REAL-WORLD EXAMPLE
1638		2012
…		…
1711		2085
1712	The actual code goes further and collects all errors (C<die>s, exceptions)	2086	The actual code goes further and collects all errors (C<die>s, exceptions)
1713	that occurred during request processing. The C<result> method detects	2087	that occurred during request processing. The C<result> method detects
1714	whether an exception as thrown (it is stored inside the $txn object)	2088	whether an exception as thrown (it is stored inside the $txn object)
1715	and just throws the exception, which means connection errors and other	2089	and just throws the exception, which means connection errors and other
1716	problems get reported tot he code that tries to use the result, not in a	2090	problems get reported to the code that tries to use the result, not in a
1717	random callback.	2091	random callback.
1718		2092
1719	All of this enables the following usage styles:	2093	All of this enables the following usage styles:
1720		2094
1721	1. Blocking:	2095	1. Blocking:
…		…
1769	through AnyEvent. The benchmark creates a lot of timers (with a zero	2143	through AnyEvent. The benchmark creates a lot of timers (with a zero
1770	timeout) and I/O watchers (watching STDOUT, a pty, to become writable,	2144	timeout) and I/O watchers (watching STDOUT, a pty, to become writable,
1771	which it is), lets them fire exactly once and destroys them again.	2145	which it is), lets them fire exactly once and destroys them again.
1772		2146
1773	Source code for this benchmark is found as F<eg/bench> in the AnyEvent	2147	Source code for this benchmark is found as F<eg/bench> in the AnyEvent
1774	distribution.	2148	distribution. It uses the L<AE> interface, which makes a real difference
		2149	for the EV and Perl backends only.
1775		2150
1776	=head3 Explanation of the columns	2151	=head3 Explanation of the columns
1777		2152
1778	I<watcher> is the number of event watchers created/destroyed. Since	2153	I<watcher> is the number of event watchers created/destroyed. Since
1779	different event models feature vastly different performances, each event	2154	different event models feature vastly different performances, each event
…		…
1800	watcher.	2175	watcher.
1801		2176
1802	=head3 Results	2177	=head3 Results
1803		2178
1804	name watchers bytes create invoke destroy comment	2179	name watchers bytes create invoke destroy comment
1805	EV/EV 400000 224 0.47 0.35 0.27 EV native interface	2180	EV/EV 100000 223 0.47 0.43 0.27 EV native interface
1806	EV/Any 100000 224 2.88 0.34 0.27 EV + AnyEvent watchers	2181	EV/Any 100000 223 0.48 0.42 0.26 EV + AnyEvent watchers
1807	CoroEV/Any 100000 224 2.85 0.35 0.28 coroutines + Coro::Signal	2182	Coro::EV/Any 100000 223 0.47 0.42 0.26 coroutines + Coro::Signal
1808	Perl/Any 100000 452 4.13 0.73 0.95 pure perl implementation	2183	Perl/Any 100000 431 2.70 0.74 0.92 pure perl implementation
1809	Event/Event 16000 517 32.20 31.80 0.81 Event native interface	2184	Event/Event 16000 516 31.16 31.84 0.82 Event native interface
1810	Event/Any 16000 590 35.85 31.55 1.06 Event + AnyEvent watchers	2185	Event/Any 16000 1203 42.61 34.79 1.80 Event + AnyEvent watchers
1811	IOAsync/Any 16000 989 38.10 32.77 11.13 via IO::Async::Loop::IO_Poll	2186	IOAsync/Any 16000 1911 41.92 27.45 16.81 via IO::Async::Loop::IO_Poll
1812	IOAsync/Any 16000 990 37.59 29.50 10.61 via IO::Async::Loop::Epoll	2187	IOAsync/Any 16000 1726 40.69 26.37 15.25 via IO::Async::Loop::Epoll
1813	Glib/Any 16000 1357 102.33 12.31 51.00 quadratic behaviour	2188	Glib/Any 16000 1118 89.00 12.57 51.17 quadratic behaviour
1814	Tk/Any 2000 1860 27.20 66.31 14.00 SEGV with >> 2000 watchers	2189	Tk/Any 2000 1346 20.96 10.75 8.00 SEGV with >> 2000 watchers
1815	POE/Event 2000 6328 109.99 751.67 14.02 via POE::Loop::Event	2190	POE/Any 2000 6951 108.97 795.32 14.24 via POE::Loop::Event
1816	POE/Select 2000 6027 94.54 809.13 579.80 via POE::Loop::Select	2191	POE/Any 2000 6648 94.79 774.40 575.51 via POE::Loop::Select
1817		2192
1818	=head3 Discussion	2193	=head3 Discussion
1819		2194
1820	The benchmark does I<not> measure scalability of the event loop very	2195	The benchmark does I<not> measure scalability of the event loop very
1821	well. For example, a select-based event loop (such as the pure perl one)	2196	well. For example, a select-based event loop (such as the pure perl one)
…		…
1833	benchmark machine, handling an event takes roughly 1600 CPU cycles with	2208	benchmark machine, handling an event takes roughly 1600 CPU cycles with
1834	EV, 3100 CPU cycles with AnyEvent's pure perl loop and almost 3000000 CPU	2209	EV, 3100 CPU cycles with AnyEvent's pure perl loop and almost 3000000 CPU
1835	cycles with POE.	2210	cycles with POE.
1836		2211
1837	C<EV> is the sole leader regarding speed and memory use, which are both	2212	C<EV> is the sole leader regarding speed and memory use, which are both
1838	maximal/minimal, respectively. Even when going through AnyEvent, it uses	2213	maximal/minimal, respectively. When using the L<AE> API there is zero
		2214	overhead (when going through the AnyEvent API create is about 5-6 times
		2215	slower, with other times being equal, so still uses far less memory than
1839	far less memory than any other event loop and is still faster than Event	2216	any other event loop and is still faster than Event natively).
1840	natively.
1841		2217
1842	The pure perl implementation is hit in a few sweet spots (both the	2218	The pure perl implementation is hit in a few sweet spots (both the
1843	constant timeout and the use of a single fd hit optimisations in the perl	2219	constant timeout and the use of a single fd hit optimisations in the perl
1844	interpreter and the backend itself). Nevertheless this shows that it	2220	interpreter and the backend itself). Nevertheless this shows that it
1845	adds very little overhead in itself. Like any select-based backend its	2221	adds very little overhead in itself. Like any select-based backend its
…		…
1919	In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100	2295	In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100
1920	(1%) are active. This mirrors the activity of large servers with many	2296	(1%) are active. This mirrors the activity of large servers with many
1921	connections, most of which are idle at any one point in time.	2297	connections, most of which are idle at any one point in time.
1922		2298
1923	Source code for this benchmark is found as F<eg/bench2> in the AnyEvent	2299	Source code for this benchmark is found as F<eg/bench2> in the AnyEvent
1924	distribution.	2300	distribution. It uses the L<AE> interface, which makes a real difference
		2301	for the EV and Perl backends only.
1925		2302
1926	=head3 Explanation of the columns	2303	=head3 Explanation of the columns
1927		2304
1928	I<sockets> is the number of sockets, and twice the number of "servers" (as	2305	I<sockets> is the number of sockets, and twice the number of "servers" (as
1929	each server has a read and write socket end).	2306	each server has a read and write socket end).
…		…
1937	a new one that moves the timeout into the future.	2314	a new one that moves the timeout into the future.
1938		2315
1939	=head3 Results	2316	=head3 Results
1940		2317
1941	name sockets create request	2318	name sockets create request
1942	EV 20000 69.01 11.16	2319	EV 20000 62.66 7.99
1943	Perl 20000 73.32 35.87	2320	Perl 20000 68.32 32.64
1944	IOAsync 20000 157.00 98.14 epoll	2321	IOAsync 20000 174.06 101.15 epoll
1945	IOAsync 20000 159.31 616.06 poll	2322	IOAsync 20000 174.67 610.84 poll
1946	Event 20000 212.62 257.32	2323	Event 20000 202.69 242.91
1947	Glib 20000 651.16 1896.30	2324	Glib 20000 557.01 1689.52
1948	POE 20000 349.67 12317.24 uses POE::Loop::Event	2325	POE 20000 341.54 12086.32 uses POE::Loop::Event
1949		2326
1950	=head3 Discussion	2327	=head3 Discussion
1951		2328
1952	This benchmark I<does> measure scalability and overall performance of the	2329	This benchmark I<does> measure scalability and overall performance of the
1953	particular event loop.	2330	particular event loop.
…		…
2079	As you can see, the AnyEvent + EV combination even beats the	2456	As you can see, the AnyEvent + EV combination even beats the
2080	hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl	2457	hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl
2081	backend easily beats IO::Lambda and POE.	2458	backend easily beats IO::Lambda and POE.
2082		2459
2083	And even the 100% non-blocking version written using the high-level (and	2460	And even the 100% non-blocking version written using the high-level (and
2084	slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda by a	2461	slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda
2085	large margin, even though it does all of DNS, tcp-connect and socket I/O	2462	higher level ("unoptimised") abstractions by a large margin, even though
2086	in a non-blocking way.	2463	it does all of DNS, tcp-connect and socket I/O in a non-blocking way.
2087		2464
2088	The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and	2465	The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and
2089	F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are	2466	F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are
2090	part of the IO::lambda distribution and were used without any changes.	2467	part of the IO::Lambda distribution and were used without any changes.
2091		2468
2092		2469
2093	=head1 SIGNALS	2470	=head1 SIGNALS
2094		2471
2095	AnyEvent currently installs handlers for these signals:	2472	AnyEvent currently installs handlers for these signals:
…		…
2100		2477
2101	A handler for C<SIGCHLD> is installed by AnyEvent's child watcher	2478	A handler for C<SIGCHLD> is installed by AnyEvent's child watcher
2102	emulation for event loops that do not support them natively. Also, some	2479	emulation for event loops that do not support them natively. Also, some
2103	event loops install a similar handler.	2480	event loops install a similar handler.
2104		2481
2105	If, when AnyEvent is loaded, SIGCHLD is set to IGNORE, then AnyEvent will	2482	Additionally, when AnyEvent is loaded and SIGCHLD is set to IGNORE, then
2106	reset it to default, to avoid losing child exit statuses.	2483	AnyEvent will reset it to default, to avoid losing child exit statuses.
2107		2484
2108	=item SIGPIPE	2485	=item SIGPIPE
2109		2486
2110	A no-op handler is installed for C<SIGPIPE> when C<$SIG{PIPE}> is C<undef>	2487	A no-op handler is installed for C<SIGPIPE> when C<$SIG{PIPE}> is C<undef>
2111	when AnyEvent gets loaded.	2488	when AnyEvent gets loaded.
…		…
2129	if $SIG{CHLD} eq 'IGNORE';	2506	if $SIG{CHLD} eq 'IGNORE';
2130		2507
2131	$SIG{PIPE} = sub { }	2508	$SIG{PIPE} = sub { }
2132	unless defined $SIG{PIPE};	2509	unless defined $SIG{PIPE};
2133		2510
		2511	=head1 RECOMMENDED/OPTIONAL MODULES
		2512
		2513	One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and
		2514	it's built-in modules) are required to use it.
		2515
		2516	That does not mean that AnyEvent won't take advantage of some additional
		2517	modules if they are installed.
		2518
		2519	This section explains which additional modules will be used, and how they
		2520	affect AnyEvent's operation.
		2521
		2522	=over 4
		2523
		2524	=item L<Async::Interrupt>
		2525
		2526	This slightly arcane module is used to implement fast signal handling: To
		2527	my knowledge, there is no way to do completely race-free and quick
		2528	signal handling in pure perl. To ensure that signals still get
		2529	delivered, AnyEvent will start an interval timer to wake up perl (and
		2530	catch the signals) with some delay (default is 10 seconds, look for
		2531	C<$AnyEvent::MAX_SIGNAL_LATENCY>).
		2532
		2533	If this module is available, then it will be used to implement signal
		2534	catching, which means that signals will not be delayed, and the event loop
		2535	will not be interrupted regularly, which is more efficient (and good for
		2536	battery life on laptops).
		2537
		2538	This affects not just the pure-perl event loop, but also other event loops
		2539	that have no signal handling on their own (e.g. Glib, Tk, Qt).
		2540
		2541	Some event loops (POE, Event, Event::Lib) offer signal watchers natively,
		2542	and either employ their own workarounds (POE) or use AnyEvent's workaround
		2543	(using C<$AnyEvent::MAX_SIGNAL_LATENCY>). Installing L<Async::Interrupt>
		2544	does nothing for those backends.
		2545
		2546	=item L<EV>
		2547
		2548	This module isn't really "optional", as it is simply one of the backend
		2549	event loops that AnyEvent can use. However, it is simply the best event
		2550	loop available in terms of features, speed and stability: It supports
		2551	the AnyEvent API optimally, implements all the watcher types in XS, does
		2552	automatic timer adjustments even when no monotonic clock is available,
		2553	can take avdantage of advanced kernel interfaces such as C<epoll> and
		2554	C<kqueue>, and is the fastest backend I<by far>. You can even embed
		2555	L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>).
		2556
		2557	If you only use backends that rely on another event loop (e.g. C<Tk>),
		2558	then this module will do nothing for you.
		2559
		2560	=item L<Guard>
		2561
		2562	The guard module, when used, will be used to implement
		2563	C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a
		2564	lot less memory), but otherwise doesn't affect guard operation much. It is
		2565	purely used for performance.
		2566
		2567	=item L<JSON> and L<JSON::XS>
		2568
		2569	One of these modules is required when you want to read or write JSON data
		2570	via L<AnyEvent::Handle>. L<JSON> is also written in pure-perl, but can take
		2571	advantage of the ultra-high-speed L<JSON::XS> module when it is installed.
		2572
		2573	=item L<Net::SSLeay>
		2574
		2575	Implementing TLS/SSL in Perl is certainly interesting, but not very
		2576	worthwhile: If this module is installed, then L<AnyEvent::Handle> (with
		2577	the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL.
		2578
		2579	=item L<Time::HiRes>
		2580
		2581	This module is part of perl since release 5.008. It will be used when the
		2582	chosen event library does not come with a timing source on it's own. The
		2583	pure-perl event loop (L<AnyEvent::Impl::Perl>) will additionally use it to
		2584	try to use a monotonic clock for timing stability.
		2585
		2586	=back
		2587
		2588
2134	=head1 FORK	2589	=head1 FORK
2135		2590
2136	Most event libraries are not fork-safe. The ones who are usually are	2591	Most event libraries are not fork-safe. The ones who are usually are
2137	because they rely on inefficient but fork-safe C<select> or C<poll>	2592	because they rely on inefficient but fork-safe C<select> or C<poll> calls
2138	calls. Only L<EV> is fully fork-aware.	2593	- higher performance APIs such as BSD's kqueue or the dreaded Linux epoll
		2594	are usually badly thought-out hacks that are incompatible with fork in
		2595	one way or another. Only L<EV> is fully fork-aware and ensures that you
		2596	continue event-processing in both parent and child (or both, if you know
		2597	what you are doing).
		2598
		2599	This means that, in general, you cannot fork and do event processing in
		2600	the child if the event library was initialised before the fork (which
		2601	usually happens when the first AnyEvent watcher is created, or the library
		2602	is loaded).
2139		2603
2140	If you have to fork, you must either do so I<before> creating your first	2604	If you have to fork, you must either do so I<before> creating your first
2141	watcher OR you must not use AnyEvent at all in the child.	2605	watcher OR you must not use AnyEvent at all in the child OR you must do
		2606	something completely out of the scope of AnyEvent.
		2607
		2608	The problem of doing event processing in the parent I<and> the child
		2609	is much more complicated: even for backends that I<are> fork-aware or
		2610	fork-safe, their behaviour is not usually what you want: fork clones all
		2611	watchers, that means all timers, I/O watchers etc. are active in both
		2612	parent and child, which is almost never what you want. USing C<exec>
		2613	to start worker children from some kind of manage rprocess is usually
		2614	preferred, because it is much easier and cleaner, at the expense of having
		2615	to have another binary.
2142		2616
2143		2617
2144	=head1 SECURITY CONSIDERATIONS	2618	=head1 SECURITY CONSIDERATIONS
2145		2619
2146	AnyEvent can be forced to load any event model via	2620	AnyEvent can be forced to load any event model via
…		…
2184	L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.	2658	L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.
2185		2659
2186	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,	2660	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,
2187	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,	2661	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,
2188	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,	2662	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,
2189	L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>.	2663	L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>, L<Anyevent::Impl::Irssi>.
2190		2664
2191	Non-blocking file handles, sockets, TCP clients and	2665	Non-blocking file handles, sockets, TCP clients and
2192	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.	2666	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.
2193		2667
2194	Asynchronous DNS: L<AnyEvent::DNS>.	2668	Asynchronous DNS: L<AnyEvent::DNS>.

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