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Revision 1.228 by root, Wed Jul 8 01:11:12 2009 UTC vs.
Revision 1.324 by root, Thu May 20 23:55:51 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> (I<not> file descriptor, see below) to	198	C<fh> is the Perl I<file handle> (or a naked file descriptor) to watch
182	watch for events (AnyEvent might or might not keep a reference to this	199	for events (AnyEvent might or might not keep a reference to this file
183	file handle). Note that only file handles pointing to things for which	200	handle). Note that only file handles pointing to things for which
184	non-blocking operation makes sense are allowed. This includes sockets,	201	non-blocking operation makes sense are allowed. This includes sockets,
185	most character devices, pipes, fifos and so on, but not for example files	202	most character devices, pipes, fifos and so on, but not for example files
186	or block devices.	203	or block devices.
187		204
188	C<poll> must be a string that is either C<r> or C<w>, which creates a	205	C<poll> must be a string that is either C<r> or C<w>, which creates a
…		…
209	chomp (my $input = <STDIN>);	226	chomp (my $input = <STDIN>);
210	warn "read: $input\n";	227	warn "read: $input\n";
211	undef $w;	228	undef $w;
212	});	229	});
213		230
214	=head3 GETTING A FILE HANDLE FROM A FILE DESCRIPTOR
215
216	It is not uncommon to only have a file descriptor, while AnyEvent requires
217	a Perl file handle.
218
219	There are basically two methods to convert a file descriptor into a file handle. If you own
220	the file descriptor, you can open it with C<&=>, as in:
221
222	open my $fh, "<&=$fileno" or die "xxx: §!";
223
224	This will "own" the file descriptor, meaning that when C<$fh> is
225	destroyed, it will automatically close the C<$fileno>. Also, note that
226	the open mode (read, write, read/write) must correspond with how the
227	underlying file descriptor was opened.
228
229	In many cases, taking over the file descriptor is now what you want, in
230	which case the only alternative is to dup the file descriptor:
231
232	open my $fh, "<&$fileno" or die "xxx: $!";
233
234	This has the advantage of not closing the file descriptor and the
235	disadvantage of making a slow copy.
236
237	=head2 TIME WATCHERS	231	=head2 TIME WATCHERS
		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	);
238		240
239	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 >>
240	method with the following mandatory arguments:	242	method with the following mandatory arguments:
241		243
242	C<after> specifies after how many seconds (fractional values are	244	C<after> specifies after how many seconds (fractional values are
…		…
364	might affect timers and time-outs.	366	might affect timers and time-outs.
365		367
366	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
367	event loop's idea of "current time".	369	event loop's idea of "current time".
368		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
369	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.
370		379
371	=back	380	=back
372		381
373	=head2 SIGNAL WATCHERS	382	=head2 SIGNAL WATCHERS
		383
		384	$w = AnyEvent->signal (signal => <uppercase_signal_name>, cb => <callback>);
374		385
375	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
376	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
377	callback to be invoked whenever a signal occurs.	388	callback to be invoked whenever a signal occurs.
378		389
…		…
384	invocation, and callback invocation will be synchronous. Synchronous means	395	invocation, and callback invocation will be synchronous. Synchronous means
385	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,
386	but it is guaranteed not to interrupt any other callbacks.	397	but it is guaranteed not to interrupt any other callbacks.
387		398
388	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
389	between multiple watchers.	400	between multiple watchers, and AnyEvent will ensure that signals will not
		401	interrupt your program at bad times.
390		402
391	This watcher might use C<%SIG>, so programs overwriting those signals	403	This watcher might use C<%SIG> (depending on the event loop used),
392	directly will likely not work correctly.	404	so programs overwriting those signals directly will likely not work
		405	correctly.
393		406
394	Example: exit on SIGINT	407	Example: exit on SIGINT
395		408
396	my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });	409	my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });
397		410
		411	=head3 Restart Behaviour
		412
		413	While restart behaviour is up to the event loop implementation, most will
		414	not restart syscalls (that includes L<Async::Interrupt> and AnyEvent's
		415	pure perl implementation).
		416
		417	=head3 Safe/Unsafe Signals
		418
		419	Perl signals can be either "safe" (synchronous to opcode handling) or
		420	"unsafe" (asynchronous) - the former might get delayed indefinitely, the
		421	latter might corrupt your memory.
		422
		423	AnyEvent signal handlers are, in addition, synchronous to the event loop,
		424	i.e. they will not interrupt your running perl program but will only be
		425	called as part of the normal event handling (just like timer, I/O etc.
		426	callbacks, too).
		427
		428	=head3 Signal Races, Delays and Workarounds
		429
		430	Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support attaching
		431	callbacks to signals in a generic way, which is a pity, as you cannot
		432	do race-free signal handling in perl, requiring C libraries for
		433	this. AnyEvent will try to do it's best, which means in some cases,
		434	signals will be delayed. The maximum time a signal might be delayed is
		435	specified in C<$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
398	=head2 CHILD PROCESS WATCHERS	448	=head2 CHILD PROCESS WATCHERS
399		449
		450	$w = AnyEvent->child (pid => <process id>, cb => <callback>);
		451
400	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.
401		453
402	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,
403	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
404	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
405	any trace events (stopped/continued).	457	finished and an exit status is available, not on any trace events
		458	(stopped/continued).
406		459
407	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
408	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
409	callback arguments.	462	callback arguments.
410		463
…		…
426		479
427	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
428	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
429	watcher before you C<fork> the child (alternatively, you can call	482	watcher before you C<fork> the child (alternatively, you can call
430	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.
431		488
432	Example: fork a process and wait for it	489	Example: fork a process and wait for it
433		490
434	my $done = AnyEvent->condvar;	491	my $done = AnyEvent->condvar;
435		492
…		…
447	# do something else, then wait for process exit	504	# do something else, then wait for process exit
448	$done->recv;	505	$done->recv;
449		506
450	=head2 IDLE WATCHERS	507	=head2 IDLE WATCHERS
451		508
452	Sometimes there is a need to do something, but it is not so important	509	$w = AnyEvent->idle (cb => <callback>);
453	to do it instantly, but only when there is nothing better to do. This
454	"nothing better to do" is usually defined to be "no other events need
455	attention by the event loop".
456		510
457	Idle watchers ideally get invoked when the event loop has nothing	511	Repeatedly invoke the callback after the process becomes idle, until
458	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.
459	events. Instead of blocking, the idle watcher is invoked.
460		513
461	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
462	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
463	will simply call the callback "from time to time".	525	will simply call the callback "from time to time".
464		526
465	Example: read lines from STDIN, but only process them when the	527	Example: read lines from STDIN, but only process them when the
466	program is otherwise idle:	528	program is otherwise idle:
…		…
482	});	544	});
483	});	545	});
484		546
485	=head2 CONDITION VARIABLES	547	=head2 CONDITION VARIABLES
486		548
		549	$cv = AnyEvent->condvar;
		550
		551	$cv->send (<list>);
		552	my @res = $cv->recv;
		553
487	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
488	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
489	will actively watch for new events and call your callbacks.	556	will actively watch for new events and call your callbacks.
490		557
491	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
492	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).
493		560
494	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
495	because they represent a condition that must become true.	562	because they represent a condition that must become true.
496		563
		564	Now is probably a good time to look at the examples further below.
		565
497	Condition variables can be created by calling the C<< AnyEvent->condvar	566	Condition variables can be created by calling the C<< AnyEvent->condvar
498	>> method, usually without arguments. The only argument pair allowed is	567	>> method, usually without arguments. The only argument pair allowed is
499
500	C<cb>, which specifies a callback to be called when the condition variable	568	C<cb>, which specifies a callback to be called when the condition variable
501	becomes true, with the condition variable as the first argument (but not	569	becomes true, with the condition variable as the first argument (but not
502	the results).	570	the results).
503		571
504	After creation, the condition variable is "false" until it becomes "true"	572	After creation, the condition variable is "false" until it becomes "true"
…		…
509	Condition variables are similar to callbacks, except that you can	577	Condition variables are similar to callbacks, except that you can
510	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
511	in time where multiple outstanding events have been processed. And yet	579	in time where multiple outstanding events have been processed. And yet
512	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
513	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
514	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.
515		584
516	Condition variables are very useful to signal that something has finished,	585	Condition variables are very useful to signal that something has finished,
517	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,
518	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
519	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
…		…
540	eventually calls C<< -> send >>, and the "consumer side", which waits	609	eventually calls C<< -> send >>, and the "consumer side", which waits
541	for the send to occur.	610	for the send to occur.
542		611
543	Example: wait for a timer.	612	Example: wait for a timer.
544		613
545	# wait till the result is ready	614	# condition: "wait till the timer is fired"
546	my $result_ready = AnyEvent->condvar;	615	my $timer_fired = AnyEvent->condvar;
547		616
548	# do something such as adding a timer	617	# create the timer - we could wait for, say
549	# or socket watcher the calls $result_ready->send	618	# a handle becomign ready, or even an
550	# when the "result" is ready.	619	# AnyEvent::HTTP request to finish, but
551	# in this case, we simply use a timer:	620	# in this case, we simply use a timer:
552	my $w = AnyEvent->timer (	621	my $w = AnyEvent->timer (
553	after => 1,	622	after => 1,
554	cb => sub { $result_ready->send },	623	cb => sub { $timer_fired->send },
555	);	624	);
556		625
557	# this "blocks" (while handling events) till the callback	626	# this "blocks" (while handling events) till the callback
558	# calls send	627	# calls ->send
559	$result_ready->recv;	628	$timer_fired->recv;
560		629
561	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
562	condition variables are also code references.	631	variables are also callable directly.
563		632
564	my $done = AnyEvent->condvar;	633	my $done = AnyEvent->condvar;
565	my $delay = AnyEvent->timer (after => 5, cb => $done);	634	my $delay = AnyEvent->timer (after => 5, cb => $done);
566	$done->recv;	635	$done->recv;
567		636
…		…
573		642
574	...	643	...
575		644
576	my @info = $couchdb->info->recv;	645	my @info = $couchdb->info->recv;
577		646
578	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
579	results are available:	648	results are available:
580		649
581	$couchdb->info->cb (sub {	650	$couchdb->info->cb (sub {
582	my @info = $_[0]->recv;	651	my @info = $_[0]->recv;
583	});	652	});
…		…
601	immediately from within send.	670	immediately from within send.
602		671
603	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
604	future C<< ->recv >> calls.	673	future C<< ->recv >> calls.
605		674
606	Condition variables are overloaded so one can call them directly	675	Condition variables are overloaded so one can call them directly (as if
607	(as a code reference). Calling them directly is the same as calling	676	they were a code reference). Calling them directly is the same as calling
608	C<send>. Note, however, that many C-based event loops do not handle	677	C<send>.
609	overloading, so as tempting as it may be, passing a condition variable
610	instead of a callback does not work. Both the pure perl and EV loops
611	support overloading, however, as well as all functions that use perl to
612	invoke a callback (as in L<AnyEvent::Socket> and L<AnyEvent::DNS> for
613	example).
614		678
615	=item $cv->croak ($error)	679	=item $cv->croak ($error)
616		680
617	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
618	C<Carp::croak> with the given error message/object/scalar.	682	C<Carp::croak> with the given error message/object/scalar.
619		683
620	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
621	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.
622		690
623	=item $cv->begin ([group callback])	691	=item $cv->begin ([group callback])
624		692
625	=item $cv->end	693	=item $cv->end
626		694
…		…
628	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
629	to use a condition variable for the whole process.	697	to use a condition variable for the whole process.
630		698
631	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
632	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
633	>>, 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
634	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
635	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.
636		705
637	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
638	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
639	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).
640		709
…		…
667	begung can potentially be zero:	736	begung can potentially be zero:
668		737
669	my $cv = AnyEvent->condvar;	738	my $cv = AnyEvent->condvar;
670		739
671	my %result;	740	my %result;
672	$cv->begin (sub { $cv->send (\%result) });	741	$cv->begin (sub { shift->send (\%result) });
673		742
674	for my $host (@list_of_hosts) {	743	for my $host (@list_of_hosts) {
675	$cv->begin;	744	$cv->begin;
676	ping_host_then_call_callback $host, sub {	745	ping_host_then_call_callback $host, sub {
677	$result{$host} = ...;	746	$result{$host} = ...;
…		…
722	function will call C<croak>.	791	function will call C<croak>.
723		792
724	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,
725	in scalar context only the first one will be returned.	794	in scalar context only the first one will be returned.
726		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
727	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
728	(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
729	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
730	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
731	condition variables with some kind of request results and supporting	807	condition variables with some kind of request results and supporting
732	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,
733	while still supporting blocking waits if the caller so desires).	809	while still supporting blocking waits if the caller so desires).
734		810
735	Another reason I<never> to C<< ->recv >> in a module is that you cannot
736	sensibly have two C<< ->recv >>'s in parallel, as that would require
737	multiple interpreters or coroutines/threads, none of which C<AnyEvent>
738	can supply.
739
740	The L<Coro> module, however, I<can> and I<does> supply coroutines and, in
741	fact, L<Coro::AnyEvent> replaces AnyEvent's condvars by coroutine-safe
742	versions and also integrates coroutines into AnyEvent, making blocking
743	C<< ->recv >> calls perfectly safe as long as they are done from another
744	coroutine (one that doesn't run the event loop).
745
746	You can ensure that C<< -recv >> never blocks by setting a callback and	811	You can ensure that C<< -recv >> never blocks by setting a callback and
747	only calling C<< ->recv >> from within that callback (or at a later	812	only calling C<< ->recv >> from within that callback (or at a later
748	time). This will work even when the event loop does not support blocking	813	time). This will work even when the event loop does not support blocking
749	waits otherwise.	814	waits otherwise.
750		815
…		…
756	=item $cb = $cv->cb ($cb->($cv))	821	=item $cb = $cv->cb ($cb->($cv))
757		822
758	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
759	replaces it before doing so.	824	replaces it before doing so.
760		825
761	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)
762	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
763	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>
764	is guaranteed not to block.	829	inside the callback or at any later time is guaranteed not to block.
765		830
766	=back	831	=back
767		832
		833	=head1 SUPPORTED EVENT LOOPS/BACKENDS
		834
		835	The available backend classes are (every class has its own manpage):
		836
		837	=over 4
		838
		839	=item Backends that are autoprobed when no other event loop can be found.
		840
		841	EV is the preferred backend when no other event loop seems to be in
		842	use. If EV is not installed, then AnyEvent will fall back to its own
		843	pure-perl implementation, which is available everywhere as it comes with
		844	AnyEvent itself.
		845
		846	AnyEvent::Impl::EV based on EV (interface to libev, best choice).
		847	AnyEvent::Impl::Perl pure-perl implementation, fast and portable.
		848
		849	=item Backends that are transparently being picked up when they are used.
		850
		851	These will be used when they are currently loaded when the first watcher
		852	is created, in which case it is assumed that the application is using
		853	them. This means that AnyEvent will automatically pick the right backend
		854	when the main program loads an event module before anything starts to
		855	create watchers. Nothing special needs to be done by the main program.
		856
		857	AnyEvent::Impl::Event based on Event, very stable, few glitches.
		858	AnyEvent::Impl::Glib based on Glib, slow but very stable.
		859	AnyEvent::Impl::Tk based on Tk, very broken.
		860	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
		861	AnyEvent::Impl::POE based on POE, very slow, some limitations.
		862	AnyEvent::Impl::Irssi used when running within irssi.
		863
		864	=item Backends with special needs.
		865
		866	Qt requires the Qt::Application to be instantiated first, but will
		867	otherwise be picked up automatically. As long as the main program
		868	instantiates the application before any AnyEvent watchers are created,
		869	everything should just work.
		870
		871	AnyEvent::Impl::Qt based on Qt.
		872
		873	Support for IO::Async can only be partial, as it is too broken and
		874	architecturally limited to even support the AnyEvent API. It also
		875	is the only event loop that needs the loop to be set explicitly, so
		876	it can only be used by a main program knowing about AnyEvent. See
		877	L<AnyEvent::Impl::Async> for the gory details.
		878
		879	AnyEvent::Impl::IOAsync based on IO::Async, cannot be autoprobed.
		880
		881	=item Event loops that are indirectly supported via other backends.
		882
		883	Some event loops can be supported via other modules:
		884
		885	There is no direct support for WxWidgets (L<Wx>) or L<Prima>.
		886
		887	B<WxWidgets> has no support for watching file handles. However, you can
		888	use WxWidgets through the POE adaptor, as POE has a Wx backend that simply
		889	polls 20 times per second, which was considered to be too horrible to even
		890	consider for AnyEvent.
		891
		892	B<Prima> is not supported as nobody seems to be using it, but it has a POE
		893	backend, so it can be supported through POE.
		894
		895	AnyEvent knows about both L<Prima> and L<Wx>, however, and will try to
		896	load L<POE> when detecting them, in the hope that POE will pick them up,
		897	in which case everything will be automatic.
		898
		899	=back
		900
768	=head1 GLOBAL VARIABLES AND FUNCTIONS	901	=head1 GLOBAL VARIABLES AND FUNCTIONS
769		902
		903	These are not normally required to use AnyEvent, but can be useful to
		904	write AnyEvent extension modules.
		905
770	=over 4	906	=over 4
771		907
772	=item $AnyEvent::MODEL	908	=item $AnyEvent::MODEL
773		909
774	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
775	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
776	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
777	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
778	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
779		917	will be C<urxvt::anyevent>).
780	The known classes so far are:
781
782	AnyEvent::Impl::EV based on EV (an interface to libev, best choice).
783	AnyEvent::Impl::Event based on Event, second best choice.
784	AnyEvent::Impl::Perl pure-perl implementation, fast and portable.
785	AnyEvent::Impl::Glib based on Glib, third-best choice.
786	AnyEvent::Impl::Tk based on Tk, very bad choice.
787	AnyEvent::Impl::Qt based on Qt, cannot be autoprobed (see its docs).
788	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
789	AnyEvent::Impl::POE based on POE, not generic enough for full support.
790
791	# warning, support for IO::Async is only partial, as it is too broken
792	# and limited toe ven support the AnyEvent API. See AnyEvent::Impl::Async.
793	AnyEvent::Impl::IOAsync based on IO::Async, cannot be autoprobed (see its docs).
794
795	There is no support for WxWidgets, as WxWidgets has no support for
796	watching file handles. However, you can use WxWidgets through the
797	POE Adaptor, as POE has a Wx backend that simply polls 20 times per
798	second, which was considered to be too horrible to even consider for
799	AnyEvent. Likewise, other POE backends can be used by AnyEvent by using
800	it's adaptor.
801
802	AnyEvent knows about L<Prima> and L<Wx> and will try to use L<POE> when
803	autodetecting them.
804		918
805	=item AnyEvent::detect	919	=item AnyEvent::detect
806		920
807	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model	921	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model
808	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
809	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
810	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>.
811		928
812	=item $guard = AnyEvent::post_detect { BLOCK }	929	=item $guard = AnyEvent::post_detect { BLOCK }
813		930
814	Arranges for the code block to be executed as soon as the event model is	931	Arranges for the code block to be executed as soon as the event model is
815	autodetected (or immediately if this has already happened).	932	autodetected (or immediately if this has already happened).
816		933
		934	The block will be executed I<after> the actual backend has been detected
		935	(C<$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
817	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
818	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
819	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 ||= $guard;
820		965
821	=item @AnyEvent::post_detect	966	=item @AnyEvent::post_detect
822		967
823	If there are any code references in this array (you can C<push> to it	968	If there are any code references in this array (you can C<push> to it
824	before or after loading AnyEvent), then they will called directly after	969	before or after loading AnyEvent), then they will called directly after
825	the event loop has been chosen.	970	the event loop has been chosen.
826		971
827	You should check C<$AnyEvent::MODEL> before adding to this array, though:	972	You should check C<$AnyEvent::MODEL> before adding to this array, though:
828	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
829	and the array will be ignored.	974	array will be ignored.
830		975
831	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	}
832		996
833	=back	997	=back
834		998
835	=head1 WHAT TO DO IN A MODULE	999	=head1 WHAT TO DO IN A MODULE
836		1000
…		…
891		1055
892		1056
893	=head1 OTHER MODULES	1057	=head1 OTHER MODULES
894		1058
895	The following is a non-exhaustive list of additional modules that use	1059	The following is a non-exhaustive list of additional modules that use
896	AnyEvent and can therefore be mixed easily with other AnyEvent modules	1060	AnyEvent as a client and can therefore be mixed easily with other AnyEvent
897	in the same program. Some of the modules come with AnyEvent, some are	1061	modules and other event loops in the same program. Some of the modules
898	available via CPAN.	1062	come with AnyEvent, the others are available via CPAN.
899		1063
900	=over 4	1064	=over 4
901		1065
902	=item L<AnyEvent::Util>	1066	=item L<AnyEvent::Util>
903		1067
…		…
912		1076
913	=item L<AnyEvent::Handle>	1077	=item L<AnyEvent::Handle>
914		1078
915	Provide read and write buffers, manages watchers for reads and writes,	1079	Provide read and write buffers, manages watchers for reads and writes,
916	supports raw and formatted I/O, I/O queued and fully transparent and	1080	supports raw and formatted I/O, I/O queued and fully transparent and
917	non-blocking SSL/TLS.	1081	non-blocking SSL/TLS (via L<AnyEvent::TLS>.
918		1082
919	=item L<AnyEvent::DNS>	1083	=item L<AnyEvent::DNS>
920		1084
921	Provides rich asynchronous DNS resolver capabilities.	1085	Provides rich asynchronous DNS resolver capabilities.
922		1086
		1087	=item L<AnyEvent::HTTP>, L<AnyEvent::IRC>, L<AnyEvent::XMPP>, L<AnyEvent::GPSD>, L<AnyEvent::IGS>, L<AnyEvent::FCP>
		1088
		1089	Implement event-based interfaces to the protocols of the same name (for
		1090	the curious, IGS is the International Go Server and FCP is the Freenet
		1091	Client Protocol).
		1092
		1093	=item L<AnyEvent::Handle::UDP>
		1094
		1095	Here be danger!
		1096
		1097	As Pauli would put it, "Not only is it not right, it's not even wrong!" -
		1098	there are so many things wrong with AnyEvent::Handle::UDP, most notably
		1099	it's use of a stream-based API with a protocol that isn't streamable, that
		1100	the only way to improve it is to delete it.
		1101
		1102	It features data corruption (but typically only under load) and general
		1103	confusion. On top, the author is not only clueless about UDP but also
		1104	fact-resistant - some gems of his understanding: "connect doesn't work
		1105	with UDP", "UDP packets are not IP packets", "UDP only has datagrams, not
		1106	packets", "I don't need to implement proper error checking as UDP doesn't
		1107	support error checking" and so on - he doesn't even understand what's
		1108	wrong with his module when it is explained to him.
		1109
923	=item L<AnyEvent::HTTP>	1110	=item L<AnyEvent::DBI>
924		1111
925	A simple-to-use HTTP library that is capable of making a lot of concurrent	1112	Executes L<DBI> requests asynchronously in a proxy process for you,
926	HTTP requests.	1113	notifying you in an event-bnased way when the operation is finished.
		1114
		1115	=item L<AnyEvent::AIO>
		1116
		1117	Truly asynchronous (as opposed to non-blocking) I/O, should be in the
		1118	toolbox of every event programmer. AnyEvent::AIO transparently fuses
		1119	L<IO::AIO> and AnyEvent together, giving AnyEvent access to event-based
		1120	file I/O, and much more.
927		1121
928	=item L<AnyEvent::HTTPD>	1122	=item L<AnyEvent::HTTPD>
929		1123
930	Provides a simple web application server framework.	1124	A simple embedded webserver.
931		1125
932	=item L<AnyEvent::FastPing>	1126	=item L<AnyEvent::FastPing>
933		1127
934	The fastest ping in the west.	1128	The fastest ping in the west.
935		1129
936	=item L<AnyEvent::DBI>
937
938	Executes L<DBI> requests asynchronously in a proxy process.
939
940	=item L<AnyEvent::AIO>
941
942	Truly asynchronous I/O, should be in the toolbox of every event
943	programmer. AnyEvent::AIO transparently fuses L<IO::AIO> and AnyEvent
944	together.
945
946	=item L<AnyEvent::BDB>
947
948	Truly asynchronous Berkeley DB access. AnyEvent::BDB transparently fuses
949	L<BDB> and AnyEvent together.
950
951	=item L<AnyEvent::GPSD>
952
953	A non-blocking interface to gpsd, a daemon delivering GPS information.
954
955	=item L<AnyEvent::IGS>
956
957	A non-blocking interface to the Internet Go Server protocol (used by
958	L<App::IGS>).
959
960	=item L<AnyEvent::IRC>
961
962	AnyEvent based IRC client module family (replacing the older Net::IRC3).
963
964	=item L<Net::XMPP2>
965
966	AnyEvent based XMPP (Jabber protocol) module family.
967
968	=item L<Net::FCP>
969
970	AnyEvent-based implementation of the Freenet Client Protocol, birthplace
971	of AnyEvent.
972
973	=item L<Event::ExecFlow>
974
975	High level API for event-based execution flow control.
976
977	=item L<Coro>	1130	=item L<Coro>
978		1131
979	Has special support for AnyEvent via L<Coro::AnyEvent>.	1132	Has special support for AnyEvent via L<Coro::AnyEvent>.
980		1133
981	=item L<IO::Lambda>
982
983	The lambda approach to I/O - don't ask, look there. Can use AnyEvent.
984
985	=back	1134	=back
986		1135
987	=cut	1136	=cut
988		1137
989	package AnyEvent;	1138	package AnyEvent;
990		1139
991	no warnings;	1140	# basically a tuned-down version of common::sense
992	use strict qw(vars subs);	1141	sub common_sense {
		1142	# from common:.sense 1.0
		1143	${^WARNING_BITS} = "\xfc\x3f\x33\x00\x0f\xf3\xcf\xc0\xf3\xfc\x33\x00";
		1144	# use strict vars subs - NO UTF-8, as Util.pm doesn't like this atm. (uts46data.pl)
		1145	$^H |= 0x00000600;
		1146	}
993		1147
		1148	BEGIN { AnyEvent::common_sense }
		1149
994	use Carp;	1150	use Carp ();
995		1151
996	our $VERSION = 4.8;	1152	our $VERSION = '5.261';
997	our $MODEL;	1153	our $MODEL;
998		1154
999	our $AUTOLOAD;	1155	our $AUTOLOAD;
1000	our @ISA;	1156	our @ISA;
1001		1157
1002	our @REGISTRY;	1158	our @REGISTRY;
1003		1159
1004	our $WIN32;	1160	our $VERBOSE;
1005		1161
1006	BEGIN {	1162	BEGIN {
1007	eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }";	1163	require "AnyEvent/constants.pl";
		1164
1008	eval "sub TAINT(){ " . (${^TAINT}*1) . " }";	1165	eval "sub TAINT (){" . (${^TAINT}*1) . "}";
1009		1166
1010	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}	1167	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}
1011	if ${^TAINT};	1168	if ${^TAINT};
1012	}
1013		1169
1014	our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1;	1170	$VERBOSE = $ENV{PERL_ANYEVENT_VERBOSE}*1;
		1171
		1172	}
		1173
		1174	our $MAX_SIGNAL_LATENCY = 10;
1015		1175
1016	our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred	1176	our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred
1017		1177
1018	{	1178	{
1019	my $idx;	1179	my $idx;
…		…
1021	for reverse split /\s*,\s*/,	1181	for reverse split /\s*,\s*/,
1022	$ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";	1182	$ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";
1023	}	1183	}
1024		1184
1025	my @models = (	1185	my @models = (
1026	[EV:: => AnyEvent::Impl::EV::],	1186	[EV:: => AnyEvent::Impl::EV:: , 1],
1027	[Event:: => AnyEvent::Impl::Event::],
1028	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::],	1187	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl:: , 1],
1029	# everything below here will not be autoprobed	1188	# everything below here will not (normally) be autoprobed
1030	# as the pureperl backend should work everywhere	1189	# as the pureperl backend should work everywhere
1031	# and is usually faster	1190	# and is usually faster
		1191	[Event:: => AnyEvent::Impl::Event::, 1],
		1192	[Glib:: => AnyEvent::Impl::Glib:: , 1], # becomes extremely slow with many watchers
		1193	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
		1194	[Irssi:: => AnyEvent::Impl::Irssi::], # Irssi has a bogus "Event" package
1032	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles	1195	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
1033	[Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers
1034	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
1035	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program	1196	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program
1036	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza	1197	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
1037	[Wx:: => AnyEvent::Impl::POE::],	1198	[Wx:: => AnyEvent::Impl::POE::],
1038	[Prima:: => AnyEvent::Impl::POE::],	1199	[Prima:: => AnyEvent::Impl::POE::],
1039	# IO::Async is just too broken - we would need workaorunds for its	1200	# IO::Async is just too broken - we would need workarounds for its
1040	# byzantine signal and broken child handling, among others.	1201	# byzantine signal and broken child handling, among others.
1041	# IO::Async is rather hard to detect, as it doesn't have any	1202	# IO::Async is rather hard to detect, as it doesn't have any
1042	# obvious default class.	1203	# obvious default class.
1043	# [IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program	1204	[IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program
1044	# [IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program	1205	[IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program
1045	# [IO::Async::Notifier:: => AnyEvent::Impl::IOAsync::], # requires special main program	1206	[IO::Async::Notifier:: => AnyEvent::Impl::IOAsync::], # requires special main program
		1207	[AnyEvent::Impl::IOAsync:: => AnyEvent::Impl::IOAsync::], # requires special main program
1046	);	1208	);
1047		1209
1048	our %method = map +($_ => 1),	1210	our %method = map +($_ => 1),
1049	qw(io timer time now now_update signal child idle condvar one_event DESTROY);	1211	qw(io timer time now now_update signal child idle condvar one_event DESTROY);
1050		1212
1051	our @post_detect;	1213	our @post_detect;
1052		1214
1053	sub post_detect(&) {	1215	sub post_detect(&) {
1054	my ($cb) = @_;	1216	my ($cb) = @_;
1055		1217
1056	if ($MODEL) {
1057	$cb->();
1058
1059	1
1060	} else {
1061	push @post_detect, $cb;	1218	push @post_detect, $cb;
1062		1219
1063	defined wantarray	1220	defined wantarray
1064	? bless \$cb, "AnyEvent::Util::postdetect"	1221	? bless \$cb, "AnyEvent::Util::postdetect"
1065	: ()	1222	: ()
1066	}
1067	}	1223	}
1068		1224
1069	sub AnyEvent::Util::postdetect::DESTROY {	1225	sub AnyEvent::Util::postdetect::DESTROY {
1070	@post_detect = grep $_ != ${$_[0]}, @post_detect;	1226	@post_detect = grep $_ != ${$_[0]}, @post_detect;
1071	}	1227	}
1072		1228
1073	sub detect() {	1229	sub detect() {
		1230	# free some memory
		1231	*detect = sub () { $MODEL };
		1232
		1233	local $!; # for good measure
		1234	local $SIG{__DIE__};
		1235
		1236	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {
		1237	my $model = "AnyEvent::Impl::$1";
		1238	if (eval "require $model") {
		1239	$MODEL = $model;
		1240	warn "AnyEvent: loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.\n" if $VERBOSE >= 2;
		1241	} else {
		1242	warn "AnyEvent: unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@" if $VERBOSE;
		1243	}
		1244	}
		1245
		1246	# check for already loaded models
1074	unless ($MODEL) {	1247	unless ($MODEL) {
1075	no strict 'refs';	1248	for (@REGISTRY, @models) {
1076	local $SIG{__DIE__};	1249	my ($package, $model) = @$_;
1077		1250	if (${"$package\::VERSION"} > 0) {
1078	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {
1079	my $model = "AnyEvent::Impl::$1";
1080	if (eval "require $model") {	1251	if (eval "require $model") {
1081	$MODEL = $model;	1252	$MODEL = $model;
1082	warn "AnyEvent: loaded model '$model' (forced by \$PERL_ANYEVENT_MODEL), using it.\n" if $verbose > 1;	1253	warn "AnyEvent: autodetected model '$model', using it.\n" if $VERBOSE >= 2;
1083	} else {	1254	last;
1084	warn "AnyEvent: unable to load model '$model' (from \$PERL_ANYEVENT_MODEL):\n$@" if $verbose;	1255	}
1085	}	1256	}
1086	}	1257	}
1087		1258
1088	# check for already loaded models
1089	unless ($MODEL) {	1259	unless ($MODEL) {
		1260	# try to autoload a model
1090	for (@REGISTRY, @models) {	1261	for (@REGISTRY, @models) {
1091	my ($package, $model) = @$_;	1262	my ($package, $model, $autoload) = @$_;
		1263	if (
		1264	$autoload
		1265	and eval "require $package"
1092	if (${"$package\::VERSION"} > 0) {	1266	and ${"$package\::VERSION"} > 0
1093	if (eval "require $model") {	1267	and eval "require $model"
		1268	) {
1094	$MODEL = $model;	1269	$MODEL = $model;
1095	warn "AnyEvent: autodetected model '$model', using it.\n" if $verbose > 1;	1270	warn "AnyEvent: autoloaded model '$model', using it.\n" if $VERBOSE >= 2;
1096	last;	1271	last;
1097	}
1098	}	1272	}
1099	}	1273	}
1100		1274
1101	unless ($MODEL) {
1102	# try to load a model
1103
1104	for (@REGISTRY, @models) {
1105	my ($package, $model) = @$_;
1106	if (eval "require $package"
1107	and ${"$package\::VERSION"} > 0
1108	and eval "require $model") {
1109	$MODEL = $model;
1110	warn "AnyEvent: autoprobed model '$model', using it.\n" if $verbose > 1;
1111	last;
1112	}
1113	}
1114
1115	$MODEL	1275	$MODEL
1116	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.\n";	1276	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.\n";
1117	}
1118	}	1277	}
1119
1120	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
1121
1122	unshift @ISA, $MODEL;
1123
1124	require AnyEvent::Strict if $ENV{PERL_ANYEVENT_STRICT};
1125
1126	(shift @post_detect)->() while @post_detect;
1127	}	1278	}
		1279
		1280	@models = (); # free probe data
		1281
		1282	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
		1283	unshift @ISA, $MODEL;
		1284
		1285	# now nuke some methods that are overriden by the backend.
		1286	# SUPER is not allowed.
		1287	for (qw(time signal child idle)) {
		1288	undef &{"AnyEvent::Base::$_"}
		1289	if defined &{"$MODEL\::$_"};
		1290	}
		1291
		1292	require AnyEvent::Strict if $ENV{PERL_ANYEVENT_STRICT};
		1293
		1294	(shift @post_detect)->() while @post_detect;
		1295
		1296	*post_detect = sub(&) {
		1297	shift->();
		1298
		1299	undef
		1300	};
1128		1301
1129	$MODEL	1302	$MODEL
1130	}	1303	}
1131		1304
1132	sub AUTOLOAD {	1305	sub AUTOLOAD {
1133	(my $func = $AUTOLOAD) =~ s/.*://;	1306	(my $func = $AUTOLOAD) =~ s/.*://;
1134		1307
1135	$method{$func}	1308	$method{$func}
1136	or croak "$func: not a valid method for AnyEvent objects";	1309	or Carp::croak "$func: not a valid AnyEvent class method";
1137		1310
1138	detect unless $MODEL;	1311	detect;
1139		1312
1140	my $class = shift;	1313	my $class = shift;
1141	$class->$func (@_);	1314	$class->$func (@_);
1142	}	1315	}
1143		1316
…		…
1146	# allow only one watcher per fd, so we dup it to get a different one).	1319	# allow only one watcher per fd, so we dup it to get a different one).
1147	sub _dupfh($$;$$) {	1320	sub _dupfh($$;$$) {
1148	my ($poll, $fh, $r, $w) = @_;	1321	my ($poll, $fh, $r, $w) = @_;
1149		1322
1150	# cygwin requires the fh mode to be matching, unix doesn't	1323	# cygwin requires the fh mode to be matching, unix doesn't
1151	my ($rw, $mode) = $poll eq "r" ? ($r, "<")	1324	my ($rw, $mode) = $poll eq "r" ? ($r, "<&") : ($w, ">&");
1152	: $poll eq "w" ? ($w, ">")
1153	: Carp::croak "AnyEvent->io requires poll set to either 'r' or 'w'";
1154		1325
1155	open my $fh2, "$mode&" . fileno $fh	1326	open my $fh2, $mode, $fh
1156	or die "cannot dup() filehandle: $!,";	1327	or die "AnyEvent->io: cannot dup() filehandle in mode '$poll': $!,";
1157		1328
1158	# we assume CLOEXEC is already set by perl in all important cases	1329	# we assume CLOEXEC is already set by perl in all important cases
1159		1330
1160	($fh2, $rw)	1331	($fh2, $rw)
1161	}	1332	}
1162		1333
		1334	=head1 SIMPLIFIED AE API
		1335
		1336	Starting with version 5.0, AnyEvent officially supports a second, much
		1337	simpler, API that is designed to reduce the calling, typing and memory
		1338	overhead by using function call syntax and a fixed number of parameters.
		1339
		1340	See the L<AE> manpage for details.
		1341
		1342	=cut
		1343
		1344	package AE;
		1345
		1346	our $VERSION = $AnyEvent::VERSION;
		1347
		1348	# fall back to the main API by default - backends and AnyEvent::Base
		1349	# implementations can overwrite these.
		1350
		1351	sub io($$$) {
		1352	AnyEvent->io (fh => $_[0], poll => $_[1] ? "w" : "r", cb => $_[2])
		1353	}
		1354
		1355	sub timer($$$) {
		1356	AnyEvent->timer (after => $_[0], interval => $_[1], cb => $_[2])
		1357	}
		1358
		1359	sub signal($$) {
		1360	AnyEvent->signal (signal => $_[0], cb => $_[1])
		1361	}
		1362
		1363	sub child($$) {
		1364	AnyEvent->child (pid => $_[0], cb => $_[1])
		1365	}
		1366
		1367	sub idle($) {
		1368	AnyEvent->idle (cb => $_[0])
		1369	}
		1370
		1371	sub cv(;&) {
		1372	AnyEvent->condvar (@_ ? (cb => $_[0]) : ())
		1373	}
		1374
		1375	sub now() {
		1376	AnyEvent->now
		1377	}
		1378
		1379	sub now_update() {
		1380	AnyEvent->now_update
		1381	}
		1382
		1383	sub time() {
		1384	AnyEvent->time
		1385	}
		1386
1163	package AnyEvent::Base;	1387	package AnyEvent::Base;
1164		1388
1165	# default implementations for many methods	1389	# default implementations for many methods
1166		1390
1167	BEGIN {	1391	sub time {
		1392	eval q{ # poor man's autoloading {}
		1393	# probe for availability of Time::HiRes
1168	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {	1394	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {
		1395	warn "AnyEvent: using Time::HiRes for sub-second timing accuracy.\n" if $VERBOSE >= 8;
1169	*_time = \&Time::HiRes::time;	1396	*AE::time = \&Time::HiRes::time;
1170	# if (eval "use POSIX (); (POSIX::times())...	1397	# if (eval "use POSIX (); (POSIX::times())...
1171	} else {	1398	} else {
		1399	warn "AnyEvent: using built-in time(), WARNING, no sub-second resolution!\n" if $VERBOSE;
1172	*_time = sub { time }; # epic fail	1400	*AE::time = sub (){ time }; # epic fail
		1401	}
		1402
		1403	*time = sub { AE::time }; # different prototypes
		1404	};
		1405	die if $@;
		1406
		1407	&time
		1408	}
		1409
		1410	*now = \&time;
		1411
		1412	sub now_update { }
		1413
		1414	# default implementation for ->condvar
		1415
		1416	sub condvar {
		1417	eval q{ # poor man's autoloading {}
		1418	*condvar = sub {
		1419	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"
		1420	};
		1421
		1422	*AE::cv = sub (;&) {
		1423	bless { @_ ? (_ae_cb => shift) : () }, "AnyEvent::CondVar"
		1424	};
		1425	};
		1426	die if $@;
		1427
		1428	&condvar
		1429	}
		1430
		1431	# default implementation for ->signal
		1432
		1433	our $HAVE_ASYNC_INTERRUPT;
		1434
		1435	sub _have_async_interrupt() {
		1436	$HAVE_ASYNC_INTERRUPT = 1*(!$ENV{PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT}
		1437	&& eval "use Async::Interrupt 1.02 (); 1")
		1438	unless defined $HAVE_ASYNC_INTERRUPT;
		1439
		1440	$HAVE_ASYNC_INTERRUPT
		1441	}
		1442
		1443	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);
		1444	our (%SIG_ASY, %SIG_ASY_W);
		1445	our ($SIG_COUNT, $SIG_TW);
		1446
		1447	# install a dummy wakeup watcher to reduce signal catching latency
		1448	# used by Impls
		1449	sub _sig_add() {
		1450	unless ($SIG_COUNT++) {
		1451	# try to align timer on a full-second boundary, if possible
		1452	my $NOW = AE::now;
		1453
		1454	$SIG_TW = AE::timer
		1455	$MAX_SIGNAL_LATENCY - ($NOW - int $NOW),
		1456	$MAX_SIGNAL_LATENCY,
		1457	sub { } # just for the PERL_ASYNC_CHECK
		1458	;
1173	}	1459	}
1174	}	1460	}
1175		1461
1176	sub time { _time }	1462	sub _sig_del {
1177	sub now { _time }	1463	undef $SIG_TW
1178	sub now_update { }	1464	unless --$SIG_COUNT;
1179
1180	# default implementation for ->condvar
1181
1182	sub condvar {
1183	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"
1184	}	1465	}
1185		1466
1186	# default implementation for ->signal	1467	our $_sig_name_init; $_sig_name_init = sub {
		1468	eval q{ # poor man's autoloading {}
		1469	undef $_sig_name_init;
1187		1470
1188	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);	1471	if (_have_async_interrupt) {
		1472	*sig2num = \&Async::Interrupt::sig2num;
		1473	*sig2name = \&Async::Interrupt::sig2name;
		1474	} else {
		1475	require Config;
1189		1476
1190	sub _signal_exec {	1477	my %signame2num;
1191	sysread $SIGPIPE_R, my $dummy, 4;	1478	@signame2num{ split ' ', $Config::Config{sig_name} }
		1479	= split ' ', $Config::Config{sig_num};
1192		1480
1193	while (%SIG_EV) {	1481	my @signum2name;
1194	for (keys %SIG_EV) {	1482	@signum2name[values %signame2num] = keys %signame2num;
1195	delete $SIG_EV{$_};	1483
1196	$_->() for values %{ $SIG_CB{$_} || {} };	1484	*sig2num = sub($) {
		1485	$_[0] > 0 ? shift : $signame2num{+shift}
		1486	};
		1487	*sig2name = sub ($) {
		1488	$_[0] > 0 ? $signum2name[+shift] : shift
		1489	};
1197	}	1490	}
1198	}	1491	};
1199	}	1492	die if $@;
		1493	};
		1494
		1495	sub sig2num ($) { &$_sig_name_init; &sig2num }
		1496	sub sig2name($) { &$_sig_name_init; &sig2name }
1200		1497
1201	sub signal {	1498	sub signal {
1202	my (undef, %arg) = @_;	1499	eval q{ # poor man's autoloading {}
		1500	# probe for availability of Async::Interrupt
		1501	if (_have_async_interrupt) {
		1502	warn "AnyEvent: using Async::Interrupt for race-free signal handling.\n" if $VERBOSE >= 8;
1203		1503
1204	unless ($SIGPIPE_R) {	1504	$SIGPIPE_R = new Async::Interrupt::EventPipe;
1205	require Fcntl;	1505	$SIG_IO = AE::io $SIGPIPE_R->fileno, 0, \&_signal_exec;
1206		1506
1207	if (AnyEvent::WIN32) {
1208	require AnyEvent::Util;
1209
1210	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
1211	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R) if $SIGPIPE_R;
1212	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W) if $SIGPIPE_W; # just in case
1213	} else {	1507	} else {
		1508	warn "AnyEvent: using emulated perl signal handling with latency timer.\n" if $VERBOSE >= 8;
		1509
		1510	if (AnyEvent::WIN32) {
		1511	require AnyEvent::Util;
		1512
		1513	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
		1514	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R, 1) if $SIGPIPE_R;
		1515	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W, 1) if $SIGPIPE_W; # just in case
		1516	} else {
1214	pipe $SIGPIPE_R, $SIGPIPE_W;	1517	pipe $SIGPIPE_R, $SIGPIPE_W;
1215	fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R;	1518	fcntl $SIGPIPE_R, AnyEvent::F_SETFL, AnyEvent::O_NONBLOCK if $SIGPIPE_R;
1216	fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case	1519	fcntl $SIGPIPE_W, AnyEvent::F_SETFL, AnyEvent::O_NONBLOCK if $SIGPIPE_W; # just in case
1217		1520
1218	# not strictly required, as $^F is normally 2, but let's make sure...	1521	# not strictly required, as $^F is normally 2, but let's make sure...
1219	fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;	1522	fcntl $SIGPIPE_R, AnyEvent::F_SETFD, AnyEvent::FD_CLOEXEC;
1220	fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;	1523	fcntl $SIGPIPE_W, AnyEvent::F_SETFD, AnyEvent::FD_CLOEXEC;
		1524	}
		1525
		1526	$SIGPIPE_R
		1527	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";
		1528
		1529	$SIG_IO = AE::io $SIGPIPE_R, 0, \&_signal_exec;
1221	}	1530	}
1222		1531
1223	$SIGPIPE_R	1532	*signal = $HAVE_ASYNC_INTERRUPT
1224	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";	1533	? sub {
		1534	my (undef, %arg) = @_;
1225		1535
1226	$SIG_IO = AnyEvent->io (fh => $SIGPIPE_R, poll => "r", cb => \&_signal_exec);	1536	# async::interrupt
1227	}
1228
1229	my $signal = uc $arg{signal}	1537	my $signal = sig2num $arg{signal};
1230	or Carp::croak "required option 'signal' is missing";
1231
1232	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};	1538	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
		1539
		1540	$SIG_ASY{$signal} ||= new Async::Interrupt
		1541	cb => sub { undef $SIG_EV{$signal} },
		1542	signal => $signal,
		1543	pipe => [$SIGPIPE_R->filenos],
		1544	pipe_autodrain => 0,
		1545	;
		1546
		1547	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
		1548	}
		1549	: sub {
		1550	my (undef, %arg) = @_;
		1551
		1552	# pure perl
		1553	my $signal = sig2name $arg{signal};
		1554	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
		1555
1233	$SIG{$signal} ||= sub {	1556	$SIG{$signal} ||= sub {
1234	local $!;	1557	local $!;
1235	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;	1558	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;
1236	undef $SIG_EV{$signal};	1559	undef $SIG_EV{$signal};
		1560	};
		1561
		1562	# can't do signal processing without introducing races in pure perl,
		1563	# so limit the signal latency.
		1564	_sig_add;
		1565
		1566	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
		1567	}
		1568	;
		1569
		1570	*AnyEvent::Base::signal::DESTROY = sub {
		1571	my ($signal, $cb) = @{$_[0]};
		1572
		1573	_sig_del;
		1574
		1575	delete $SIG_CB{$signal}{$cb};
		1576
		1577	$HAVE_ASYNC_INTERRUPT
		1578	? delete $SIG_ASY{$signal}
		1579	: # delete doesn't work with older perls - they then
		1580	# print weird messages, or just unconditionally exit
		1581	# instead of getting the default action.
		1582	undef $SIG{$signal}
		1583	unless keys %{ $SIG_CB{$signal} };
		1584	};
		1585
		1586	*_signal_exec = sub {
		1587	$HAVE_ASYNC_INTERRUPT
		1588	? $SIGPIPE_R->drain
		1589	: sysread $SIGPIPE_R, (my $dummy), 9;
		1590
		1591	while (%SIG_EV) {
		1592	for (keys %SIG_EV) {
		1593	delete $SIG_EV{$_};
		1594	$_->() for values %{ $SIG_CB{$_} || {} };
		1595	}
		1596	}
		1597	};
1237	};	1598	};
		1599	die if $@;
1238		1600
1239	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"	1601	&signal
1240	}
1241
1242	sub AnyEvent::Base::signal::DESTROY {
1243	my ($signal, $cb) = @{$_[0]};
1244
1245	delete $SIG_CB{$signal}{$cb};
1246
1247	# delete doesn't work with older perls - they then
1248	# print weird messages, or just unconditionally exit
1249	# instead of getting the default action.
1250	undef $SIG{$signal} unless keys %{ $SIG_CB{$signal} };
1251	}	1602	}
1252		1603
1253	# default implementation for ->child	1604	# default implementation for ->child
1254		1605
1255	our %PID_CB;	1606	our %PID_CB;
1256	our $CHLD_W;	1607	our $CHLD_W;
1257	our $CHLD_DELAY_W;	1608	our $CHLD_DELAY_W;
1258	our $WNOHANG;	1609	our $WNOHANG;
1259		1610
1260	sub _sigchld {	1611	# used by many Impl's
1261	while (0 < (my $pid = waitpid -1, $WNOHANG)) {	1612	sub _emit_childstatus($$) {
		1613	my (undef, $rpid, $rstatus) = @_;
		1614
		1615	$_->($rpid, $rstatus)
1262	$_->($pid, $?) for (values %{ $PID_CB{$pid} || {} }),	1616	for values %{ $PID_CB{$rpid} || {} },
1263	(values %{ $PID_CB{0} || {} });	1617	values %{ $PID_CB{0} || {} };
1264	}
1265	}	1618	}
1266		1619
1267	sub child {	1620	sub child {
		1621	eval q{ # poor man's autoloading {}
		1622	*_sigchld = sub {
		1623	my $pid;
		1624
		1625	AnyEvent->_emit_childstatus ($pid, $?)
		1626	while ($pid = waitpid -1, $WNOHANG) > 0;
		1627	};
		1628
		1629	*child = sub {
1268	my (undef, %arg) = @_;	1630	my (undef, %arg) = @_;
1269		1631
1270	defined (my $pid = $arg{pid} + 0)	1632	defined (my $pid = $arg{pid} + 0)
1271	or Carp::croak "required option 'pid' is missing";	1633	or Carp::croak "required option 'pid' is missing";
1272		1634
1273	$PID_CB{$pid}{$arg{cb}} = $arg{cb};	1635	$PID_CB{$pid}{$arg{cb}} = $arg{cb};
1274		1636
		1637	# WNOHANG is almost cetrainly 1 everywhere
		1638	$WNOHANG ||= $^O =~ /^(?:openbsd|netbsd|linux|freebsd|cygwin|MSWin32)$/
		1639	? 1
1275	$WNOHANG ||= eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1;	1640	: eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1;
1276		1641
1277	unless ($CHLD_W) {	1642	unless ($CHLD_W) {
1278	$CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld);	1643	$CHLD_W = AE::signal CHLD => \&_sigchld;
1279	# child could be a zombie already, so make at least one round	1644	# child could be a zombie already, so make at least one round
1280	&_sigchld;	1645	&_sigchld;
1281	}	1646	}
1282		1647
1283	bless [$pid, $arg{cb}], "AnyEvent::Base::child"	1648	bless [$pid, $arg{cb}], "AnyEvent::Base::child"
1284	}	1649	};
1285		1650
1286	sub AnyEvent::Base::child::DESTROY {	1651	*AnyEvent::Base::child::DESTROY = sub {
1287	my ($pid, $cb) = @{$_[0]};	1652	my ($pid, $cb) = @{$_[0]};
1288		1653
1289	delete $PID_CB{$pid}{$cb};	1654	delete $PID_CB{$pid}{$cb};
1290	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };	1655	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };
1291		1656
1292	undef $CHLD_W unless keys %PID_CB;	1657	undef $CHLD_W unless keys %PID_CB;
		1658	};
		1659	};
		1660	die if $@;
		1661
		1662	&child
1293	}	1663	}
1294		1664
1295	# idle emulation is done by simply using a timer, regardless	1665	# idle emulation is done by simply using a timer, regardless
1296	# of whether the process is idle or not, and not letting	1666	# of whether the process is idle or not, and not letting
1297	# the callback use more than 50% of the time.	1667	# the callback use more than 50% of the time.
1298	sub idle {	1668	sub idle {
		1669	eval q{ # poor man's autoloading {}
		1670	*idle = sub {
1299	my (undef, %arg) = @_;	1671	my (undef, %arg) = @_;
1300		1672
1301	my ($cb, $w, $rcb) = $arg{cb};	1673	my ($cb, $w, $rcb) = $arg{cb};
1302		1674
1303	$rcb = sub {	1675	$rcb = sub {
1304	if ($cb) {	1676	if ($cb) {
1305	$w = _time;	1677	$w = _time;
1306	&$cb;	1678	&$cb;
1307	$w = _time - $w;	1679	$w = _time - $w;
1308		1680
1309	# never use more then 50% of the time for the idle watcher,	1681	# never use more then 50% of the time for the idle watcher,
1310	# within some limits	1682	# within some limits
1311	$w = 0.0001 if $w < 0.0001;	1683	$w = 0.0001 if $w < 0.0001;
1312	$w = 5 if $w > 5;	1684	$w = 5 if $w > 5;
1313		1685
1314	$w = AnyEvent->timer (after => $w, cb => $rcb);	1686	$w = AE::timer $w, 0, $rcb;
1315	} else {	1687	} else {
1316	# clean up...	1688	# clean up...
1317	undef $w;	1689	undef $w;
1318	undef $rcb;	1690	undef $rcb;
		1691	}
		1692	};
		1693
		1694	$w = AE::timer 0.05, 0, $rcb;
		1695
		1696	bless \\$cb, "AnyEvent::Base::idle"
1319	}	1697	};
		1698
		1699	*AnyEvent::Base::idle::DESTROY = sub {
		1700	undef $${$_[0]};
		1701	};
1320	};	1702	};
		1703	die if $@;
1321		1704
1322	$w = AnyEvent->timer (after => 0.05, cb => $rcb);	1705	&idle
1323
1324	bless \\$cb, "AnyEvent::Base::idle"
1325	}
1326
1327	sub AnyEvent::Base::idle::DESTROY {
1328	undef $${$_[0]};
1329	}	1706	}
1330		1707
1331	package AnyEvent::CondVar;	1708	package AnyEvent::CondVar;
1332		1709
1333	our @ISA = AnyEvent::CondVar::Base::;	1710	our @ISA = AnyEvent::CondVar::Base::;
1334		1711
1335	package AnyEvent::CondVar::Base;	1712	package AnyEvent::CondVar::Base;
1336		1713
1337	use overload	1714	#use overload
1338	'&{}' => sub { my $self = shift; sub { $self->send (@_) } },	1715	# '&{}' => sub { my $self = shift; sub { $self->send (@_) } },
1339	fallback => 1;	1716	# fallback => 1;
		1717
		1718	# save 300+ kilobytes by dirtily hardcoding overloading
		1719	${"AnyEvent::CondVar::Base::OVERLOAD"}{dummy}++; # Register with magic by touching.
		1720	*{'AnyEvent::CondVar::Base::()'} = sub { }; # "Make it findable via fetchmethod."
		1721	*{'AnyEvent::CondVar::Base::(&{}'} = sub { my $self = shift; sub { $self->send (@_) } }; # &{}
		1722	${'AnyEvent::CondVar::Base::()'} = 1; # fallback
		1723
		1724	our $WAITING;
1340		1725
1341	sub _send {	1726	sub _send {
1342	# nop	1727	# nop
1343	}	1728	}
1344		1729
…		…
1357	sub ready {	1742	sub ready {
1358	$_[0]{_ae_sent}	1743	$_[0]{_ae_sent}
1359	}	1744	}
1360		1745
1361	sub _wait {	1746	sub _wait {
		1747	$WAITING
		1748	and !$_[0]{_ae_sent}
		1749	and Carp::croak "AnyEvent::CondVar: recursive blocking wait detected";
		1750
		1751	local $WAITING = 1;
1362	AnyEvent->one_event while !$_[0]{_ae_sent};	1752	AnyEvent->one_event while !$_[0]{_ae_sent};
1363	}	1753	}
1364		1754
1365	sub recv {	1755	sub recv {
1366	$_[0]->_wait;	1756	$_[0]->_wait;
…		…
1368	Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak};	1758	Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak};
1369	wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0]	1759	wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0]
1370	}	1760	}
1371		1761
1372	sub cb {	1762	sub cb {
1373	$_[0]{_ae_cb} = $_[1] if @_ > 1;	1763	my $cv = shift;
		1764
		1765	@_
		1766	and $cv->{_ae_cb} = shift
		1767	and $cv->{_ae_sent}
		1768	and (delete $cv->{_ae_cb})->($cv);
		1769
1374	$_[0]{_ae_cb}	1770	$cv->{_ae_cb}
1375	}	1771	}
1376		1772
1377	sub begin {	1773	sub begin {
1378	++$_[0]{_ae_counter};	1774	++$_[0]{_ae_counter};
1379	$_[0]{_ae_end_cb} = $_[1] if @_ > 1;	1775	$_[0]{_ae_end_cb} = $_[1] if @_ > 1;
…		…
1428	C<PERL_ANYEVENT_MODEL>.	1824	C<PERL_ANYEVENT_MODEL>.
1429		1825
1430	When set to C<2> or higher, cause AnyEvent to report to STDERR which event	1826	When set to C<2> or higher, cause AnyEvent to report to STDERR which event
1431	model it chooses.	1827	model it chooses.
1432		1828
		1829	When set to C<8> or higher, then AnyEvent will report extra information on
		1830	which optional modules it loads and how it implements certain features.
		1831
1433	=item C<PERL_ANYEVENT_STRICT>	1832	=item C<PERL_ANYEVENT_STRICT>
1434		1833
1435	AnyEvent does not do much argument checking by default, as thorough	1834	AnyEvent does not do much argument checking by default, as thorough
1436	argument checking is very costly. Setting this variable to a true value	1835	argument checking is very costly. Setting this variable to a true value
1437	will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly	1836	will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly
1438	check the arguments passed to most method calls. If it finds any problems,	1837	check the arguments passed to most method calls. If it finds any problems,
1439	it will croak.	1838	it will croak.
1440		1839
1441	In other words, enables "strict" mode.	1840	In other words, enables "strict" mode.
1442		1841
1443	Unlike C<use strict>, it is definitely recommended to keep it off in	1842	Unlike C<use strict> (or it's modern cousin, C<< use L<common::sense>
1444	production. Keeping C<PERL_ANYEVENT_STRICT=1> in your environment while	1843	>>, it is definitely recommended to keep it off in production. Keeping
1445	developing programs can be very useful, however.	1844	C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs
		1845	can be very useful, however.
1446		1846
1447	=item C<PERL_ANYEVENT_MODEL>	1847	=item C<PERL_ANYEVENT_MODEL>
1448		1848
1449	This can be used to specify the event model to be used by AnyEvent, before	1849	This can be used to specify the event model to be used by AnyEvent, before
1450	auto detection and -probing kicks in. It must be a string consisting	1850	auto detection and -probing kicks in. It must be a string consisting
…		…
1512		1912
1513	When neither C<ca_file> nor C<ca_path> was specified during	1913	When neither C<ca_file> nor C<ca_path> was specified during
1514	L<AnyEvent::TLS> context creation, and either of these environment	1914	L<AnyEvent::TLS> context creation, and either of these environment
1515	variables exist, they will be used to specify CA certificate locations	1915	variables exist, they will be used to specify CA certificate locations
1516	instead of a system-dependent default.	1916	instead of a system-dependent default.
		1917
		1918	=item C<PERL_ANYEVENT_AVOID_GUARD> and C<PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT>
		1919
		1920	When these are set to C<1>, then the respective modules are not
		1921	loaded. Mostly good for testing AnyEvent itself.
1517		1922
1518	=back	1923	=back
1519		1924
1520	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE	1925	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE
1521		1926
…		…
1579	warn "read: $input\n"; # output what has been read	1984	warn "read: $input\n"; # output what has been read
1580	$cv->send if $input =~ /^q/i; # quit program if /^q/i	1985	$cv->send if $input =~ /^q/i; # quit program if /^q/i
1581	},	1986	},
1582	);	1987	);
1583		1988
1584	my $time_watcher; # can only be used once
1585
1586	sub new_timer {
1587	$timer = AnyEvent->timer (after => 1, cb => sub {	1989	my $time_watcher = AnyEvent->timer (after => 1, interval => 1, cb => sub {
1588	warn "timeout\n"; # print 'timeout' about every second	1990	warn "timeout\n"; # print 'timeout' at most every second
1589	&new_timer; # and restart the time
1590	});	1991	});
1591	}
1592
1593	new_timer; # create first timer
1594		1992
1595	$cv->recv; # wait until user enters /^q/i	1993	$cv->recv; # wait until user enters /^q/i
1596		1994
1597	=head1 REAL-WORLD EXAMPLE	1995	=head1 REAL-WORLD EXAMPLE
1598		1996
…		…
1671		2069
1672	The actual code goes further and collects all errors (C<die>s, exceptions)	2070	The actual code goes further and collects all errors (C<die>s, exceptions)
1673	that occurred during request processing. The C<result> method detects	2071	that occurred during request processing. The C<result> method detects
1674	whether an exception as thrown (it is stored inside the $txn object)	2072	whether an exception as thrown (it is stored inside the $txn object)
1675	and just throws the exception, which means connection errors and other	2073	and just throws the exception, which means connection errors and other
1676	problems get reported tot he code that tries to use the result, not in a	2074	problems get reported to the code that tries to use the result, not in a
1677	random callback.	2075	random callback.
1678		2076
1679	All of this enables the following usage styles:	2077	All of this enables the following usage styles:
1680		2078
1681	1. Blocking:	2079	1. Blocking:
…		…
1729	through AnyEvent. The benchmark creates a lot of timers (with a zero	2127	through AnyEvent. The benchmark creates a lot of timers (with a zero
1730	timeout) and I/O watchers (watching STDOUT, a pty, to become writable,	2128	timeout) and I/O watchers (watching STDOUT, a pty, to become writable,
1731	which it is), lets them fire exactly once and destroys them again.	2129	which it is), lets them fire exactly once and destroys them again.
1732		2130
1733	Source code for this benchmark is found as F<eg/bench> in the AnyEvent	2131	Source code for this benchmark is found as F<eg/bench> in the AnyEvent
1734	distribution.	2132	distribution. It uses the L<AE> interface, which makes a real difference
		2133	for the EV and Perl backends only.
1735		2134
1736	=head3 Explanation of the columns	2135	=head3 Explanation of the columns
1737		2136
1738	I<watcher> is the number of event watchers created/destroyed. Since	2137	I<watcher> is the number of event watchers created/destroyed. Since
1739	different event models feature vastly different performances, each event	2138	different event models feature vastly different performances, each event
…		…
1760	watcher.	2159	watcher.
1761		2160
1762	=head3 Results	2161	=head3 Results
1763		2162
1764	name watchers bytes create invoke destroy comment	2163	name watchers bytes create invoke destroy comment
1765	EV/EV 400000 224 0.47 0.35 0.27 EV native interface	2164	EV/EV 100000 223 0.47 0.43 0.27 EV native interface
1766	EV/Any 100000 224 2.88 0.34 0.27 EV + AnyEvent watchers	2165	EV/Any 100000 223 0.48 0.42 0.26 EV + AnyEvent watchers
1767	CoroEV/Any 100000 224 2.85 0.35 0.28 coroutines + Coro::Signal	2166	Coro::EV/Any 100000 223 0.47 0.42 0.26 coroutines + Coro::Signal
1768	Perl/Any 100000 452 4.13 0.73 0.95 pure perl implementation	2167	Perl/Any 100000 431 2.70 0.74 0.92 pure perl implementation
1769	Event/Event 16000 517 32.20 31.80 0.81 Event native interface	2168	Event/Event 16000 516 31.16 31.84 0.82 Event native interface
1770	Event/Any 16000 590 35.85 31.55 1.06 Event + AnyEvent watchers	2169	Event/Any 16000 1203 42.61 34.79 1.80 Event + AnyEvent watchers
1771	IOAsync/Any 16000 989 38.10 32.77 11.13 via IO::Async::Loop::IO_Poll	2170	IOAsync/Any 16000 1911 41.92 27.45 16.81 via IO::Async::Loop::IO_Poll
1772	IOAsync/Any 16000 990 37.59 29.50 10.61 via IO::Async::Loop::Epoll	2171	IOAsync/Any 16000 1726 40.69 26.37 15.25 via IO::Async::Loop::Epoll
1773	Glib/Any 16000 1357 102.33 12.31 51.00 quadratic behaviour	2172	Glib/Any 16000 1118 89.00 12.57 51.17 quadratic behaviour
1774	Tk/Any 2000 1860 27.20 66.31 14.00 SEGV with >> 2000 watchers	2173	Tk/Any 2000 1346 20.96 10.75 8.00 SEGV with >> 2000 watchers
1775	POE/Event 2000 6328 109.99 751.67 14.02 via POE::Loop::Event	2174	POE/Any 2000 6951 108.97 795.32 14.24 via POE::Loop::Event
1776	POE/Select 2000 6027 94.54 809.13 579.80 via POE::Loop::Select	2175	POE/Any 2000 6648 94.79 774.40 575.51 via POE::Loop::Select
1777		2176
1778	=head3 Discussion	2177	=head3 Discussion
1779		2178
1780	The benchmark does I<not> measure scalability of the event loop very	2179	The benchmark does I<not> measure scalability of the event loop very
1781	well. For example, a select-based event loop (such as the pure perl one)	2180	well. For example, a select-based event loop (such as the pure perl one)
…		…
1793	benchmark machine, handling an event takes roughly 1600 CPU cycles with	2192	benchmark machine, handling an event takes roughly 1600 CPU cycles with
1794	EV, 3100 CPU cycles with AnyEvent's pure perl loop and almost 3000000 CPU	2193	EV, 3100 CPU cycles with AnyEvent's pure perl loop and almost 3000000 CPU
1795	cycles with POE.	2194	cycles with POE.
1796		2195
1797	C<EV> is the sole leader regarding speed and memory use, which are both	2196	C<EV> is the sole leader regarding speed and memory use, which are both
1798	maximal/minimal, respectively. Even when going through AnyEvent, it uses	2197	maximal/minimal, respectively. When using the L<AE> API there is zero
		2198	overhead (when going through the AnyEvent API create is about 5-6 times
		2199	slower, with other times being equal, so still uses far less memory than
1799	far less memory than any other event loop and is still faster than Event	2200	any other event loop and is still faster than Event natively).
1800	natively.
1801		2201
1802	The pure perl implementation is hit in a few sweet spots (both the	2202	The pure perl implementation is hit in a few sweet spots (both the
1803	constant timeout and the use of a single fd hit optimisations in the perl	2203	constant timeout and the use of a single fd hit optimisations in the perl
1804	interpreter and the backend itself). Nevertheless this shows that it	2204	interpreter and the backend itself). Nevertheless this shows that it
1805	adds very little overhead in itself. Like any select-based backend its	2205	adds very little overhead in itself. Like any select-based backend its
…		…
1879	In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100	2279	In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100
1880	(1%) are active. This mirrors the activity of large servers with many	2280	(1%) are active. This mirrors the activity of large servers with many
1881	connections, most of which are idle at any one point in time.	2281	connections, most of which are idle at any one point in time.
1882		2282
1883	Source code for this benchmark is found as F<eg/bench2> in the AnyEvent	2283	Source code for this benchmark is found as F<eg/bench2> in the AnyEvent
1884	distribution.	2284	distribution. It uses the L<AE> interface, which makes a real difference
		2285	for the EV and Perl backends only.
1885		2286
1886	=head3 Explanation of the columns	2287	=head3 Explanation of the columns
1887		2288
1888	I<sockets> is the number of sockets, and twice the number of "servers" (as	2289	I<sockets> is the number of sockets, and twice the number of "servers" (as
1889	each server has a read and write socket end).	2290	each server has a read and write socket end).
…		…
1897	a new one that moves the timeout into the future.	2298	a new one that moves the timeout into the future.
1898		2299
1899	=head3 Results	2300	=head3 Results
1900		2301
1901	name sockets create request	2302	name sockets create request
1902	EV 20000 69.01 11.16	2303	EV 20000 62.66 7.99
1903	Perl 20000 73.32 35.87	2304	Perl 20000 68.32 32.64
1904	IOAsync 20000 157.00 98.14 epoll	2305	IOAsync 20000 174.06 101.15 epoll
1905	IOAsync 20000 159.31 616.06 poll	2306	IOAsync 20000 174.67 610.84 poll
1906	Event 20000 212.62 257.32	2307	Event 20000 202.69 242.91
1907	Glib 20000 651.16 1896.30	2308	Glib 20000 557.01 1689.52
1908	POE 20000 349.67 12317.24 uses POE::Loop::Event	2309	POE 20000 341.54 12086.32 uses POE::Loop::Event
1909		2310
1910	=head3 Discussion	2311	=head3 Discussion
1911		2312
1912	This benchmark I<does> measure scalability and overall performance of the	2313	This benchmark I<does> measure scalability and overall performance of the
1913	particular event loop.	2314	particular event loop.
…		…
2039	As you can see, the AnyEvent + EV combination even beats the	2440	As you can see, the AnyEvent + EV combination even beats the
2040	hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl	2441	hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl
2041	backend easily beats IO::Lambda and POE.	2442	backend easily beats IO::Lambda and POE.
2042		2443
2043	And even the 100% non-blocking version written using the high-level (and	2444	And even the 100% non-blocking version written using the high-level (and
2044	slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda by a	2445	slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda
2045	large margin, even though it does all of DNS, tcp-connect and socket I/O	2446	higher level ("unoptimised") abstractions by a large margin, even though
2046	in a non-blocking way.	2447	it does all of DNS, tcp-connect and socket I/O in a non-blocking way.
2047		2448
2048	The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and	2449	The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and
2049	F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are	2450	F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are
2050	part of the IO::lambda distribution and were used without any changes.	2451	part of the IO::Lambda distribution and were used without any changes.
2051		2452
2052		2453
2053	=head1 SIGNALS	2454	=head1 SIGNALS
2054		2455
2055	AnyEvent currently installs handlers for these signals:	2456	AnyEvent currently installs handlers for these signals:
…		…
2060		2461
2061	A handler for C<SIGCHLD> is installed by AnyEvent's child watcher	2462	A handler for C<SIGCHLD> is installed by AnyEvent's child watcher
2062	emulation for event loops that do not support them natively. Also, some	2463	emulation for event loops that do not support them natively. Also, some
2063	event loops install a similar handler.	2464	event loops install a similar handler.
2064		2465
2065	If, when AnyEvent is loaded, SIGCHLD is set to IGNORE, then AnyEvent will	2466	Additionally, when AnyEvent is loaded and SIGCHLD is set to IGNORE, then
2066	reset it to default, to avoid losing child exit statuses.	2467	AnyEvent will reset it to default, to avoid losing child exit statuses.
2067		2468
2068	=item SIGPIPE	2469	=item SIGPIPE
2069		2470
2070	A no-op handler is installed for C<SIGPIPE> when C<$SIG{PIPE}> is C<undef>	2471	A no-op handler is installed for C<SIGPIPE> when C<$SIG{PIPE}> is C<undef>
2071	when AnyEvent gets loaded.	2472	when AnyEvent gets loaded.
…		…
2089	if $SIG{CHLD} eq 'IGNORE';	2490	if $SIG{CHLD} eq 'IGNORE';
2090		2491
2091	$SIG{PIPE} = sub { }	2492	$SIG{PIPE} = sub { }
2092	unless defined $SIG{PIPE};	2493	unless defined $SIG{PIPE};
2093		2494
		2495	=head1 RECOMMENDED/OPTIONAL MODULES
		2496
		2497	One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and
		2498	it's built-in modules) are required to use it.
		2499
		2500	That does not mean that AnyEvent won't take advantage of some additional
		2501	modules if they are installed.
		2502
		2503	This section explains which additional modules will be used, and how they
		2504	affect AnyEvent's operation.
		2505
		2506	=over 4
		2507
		2508	=item L<Async::Interrupt>
		2509
		2510	This slightly arcane module is used to implement fast signal handling: To
		2511	my knowledge, there is no way to do completely race-free and quick
		2512	signal handling in pure perl. To ensure that signals still get
		2513	delivered, AnyEvent will start an interval timer to wake up perl (and
		2514	catch the signals) with some delay (default is 10 seconds, look for
		2515	C<$AnyEvent::MAX_SIGNAL_LATENCY>).
		2516
		2517	If this module is available, then it will be used to implement signal
		2518	catching, which means that signals will not be delayed, and the event loop
		2519	will not be interrupted regularly, which is more efficient (and good for
		2520	battery life on laptops).
		2521
		2522	This affects not just the pure-perl event loop, but also other event loops
		2523	that have no signal handling on their own (e.g. Glib, Tk, Qt).
		2524
		2525	Some event loops (POE, Event, Event::Lib) offer signal watchers natively,
		2526	and either employ their own workarounds (POE) or use AnyEvent's workaround
		2527	(using C<$AnyEvent::MAX_SIGNAL_LATENCY>). Installing L<Async::Interrupt>
		2528	does nothing for those backends.
		2529
		2530	=item L<EV>
		2531
		2532	This module isn't really "optional", as it is simply one of the backend
		2533	event loops that AnyEvent can use. However, it is simply the best event
		2534	loop available in terms of features, speed and stability: It supports
		2535	the AnyEvent API optimally, implements all the watcher types in XS, does
		2536	automatic timer adjustments even when no monotonic clock is available,
		2537	can take avdantage of advanced kernel interfaces such as C<epoll> and
		2538	C<kqueue>, and is the fastest backend I<by far>. You can even embed
		2539	L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>).
		2540
		2541	If you only use backends that rely on another event loop (e.g. C<Tk>),
		2542	then this module will do nothing for you.
		2543
		2544	=item L<Guard>
		2545
		2546	The guard module, when used, will be used to implement
		2547	C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a
		2548	lot less memory), but otherwise doesn't affect guard operation much. It is
		2549	purely used for performance.
		2550
		2551	=item L<JSON> and L<JSON::XS>
		2552
		2553	One of these modules is required when you want to read or write JSON data
		2554	via L<AnyEvent::Handle>. L<JSON> is also written in pure-perl, but can take
		2555	advantage of the ultra-high-speed L<JSON::XS> module when it is installed.
		2556
		2557	=item L<Net::SSLeay>
		2558
		2559	Implementing TLS/SSL in Perl is certainly interesting, but not very
		2560	worthwhile: If this module is installed, then L<AnyEvent::Handle> (with
		2561	the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL.
		2562
		2563	=item L<Time::HiRes>
		2564
		2565	This module is part of perl since release 5.008. It will be used when the
		2566	chosen event library does not come with a timing source on it's own. The
		2567	pure-perl event loop (L<AnyEvent::Impl::Perl>) will additionally use it to
		2568	try to use a monotonic clock for timing stability.
		2569
		2570	=back
		2571
		2572
2094	=head1 FORK	2573	=head1 FORK
2095		2574
2096	Most event libraries are not fork-safe. The ones who are usually are	2575	Most event libraries are not fork-safe. The ones who are usually are
2097	because they rely on inefficient but fork-safe C<select> or C<poll>	2576	because they rely on inefficient but fork-safe C<select> or C<poll> calls
2098	calls. Only L<EV> is fully fork-aware.	2577	- higher performance APIs such as BSD's kqueue or the dreaded Linux epoll
		2578	are usually badly thought-out hacks that are incompatible with fork in
		2579	one way or another. Only L<EV> is fully fork-aware and ensures that you
		2580	continue event-processing in both parent and child (or both, if you know
		2581	what you are doing).
		2582
		2583	This means that, in general, you cannot fork and do event processing in
		2584	the child if the event library was initialised before the fork (which
		2585	usually happens when the first AnyEvent watcher is created, or the library
		2586	is loaded).
2099		2587
2100	If you have to fork, you must either do so I<before> creating your first	2588	If you have to fork, you must either do so I<before> creating your first
2101	watcher OR you must not use AnyEvent at all in the child.	2589	watcher OR you must not use AnyEvent at all in the child OR you must do
		2590	something completely out of the scope of AnyEvent.
		2591
		2592	The problem of doing event processing in the parent I<and> the child
		2593	is much more complicated: even for backends that I<are> fork-aware or
		2594	fork-safe, their behaviour is not usually what you want: fork clones all
		2595	watchers, that means all timers, I/O watchers etc. are active in both
		2596	parent and child, which is almost never what you want. USing C<exec>
		2597	to start worker children from some kind of manage rprocess is usually
		2598	preferred, because it is much easier and cleaner, at the expense of having
		2599	to have another binary.
2102		2600
2103		2601
2104	=head1 SECURITY CONSIDERATIONS	2602	=head1 SECURITY CONSIDERATIONS
2105		2603
2106	AnyEvent can be forced to load any event model via	2604	AnyEvent can be forced to load any event model via
…		…
2144	L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.	2642	L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.
2145		2643
2146	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,	2644	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,
2147	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,	2645	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,
2148	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,	2646	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,
2149	L<AnyEvent::Impl::POE>.	2647	L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>, L<Anyevent::Impl::Irssi>.
2150		2648
2151	Non-blocking file handles, sockets, TCP clients and	2649	Non-blocking file handles, sockets, TCP clients and
2152	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>.	2650	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.
2153		2651
2154	Asynchronous DNS: L<AnyEvent::DNS>.	2652	Asynchronous DNS: L<AnyEvent::DNS>.
2155		2653
2156	Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>,	2654	Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>,
		2655	L<Coro::Event>,
2157		2656
2158	Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>, L<AnyEvent::DNS>.	2657	Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::XMPP>,
		2658	L<AnyEvent::HTTP>.
2159		2659
2160		2660
2161	=head1 AUTHOR	2661	=head1 AUTHOR
2162		2662
2163	Marc Lehmann <schmorp@schmorp.de>	2663	Marc Lehmann <schmorp@schmorp.de>

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