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Revision 1.218 by root, Wed Jun 24 10:03:42 2009 UTC vs.
Revision 1.311 by root, Wed Feb 10 13:33:44 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
…		…
40	=head1 INTRODUCTION/TUTORIAL	40	=head1 INTRODUCTION/TUTORIAL
41		41
42	This manpage is mainly a reference manual. If you are interested	42	This manpage is mainly a reference manual. If you are interested
43	in a tutorial or some gentle introduction, have a look at the	43	in a tutorial or some gentle introduction, have a look at the
44	L<AnyEvent::Intro> manpage.	44	L<AnyEvent::Intro> manpage.
		45
		46	=head1 SUPPORT
		47
		48	There is a mailinglist for discussing all things AnyEvent, and an IRC
		49	channel, too.
		50
		51	See the AnyEvent project page at the B<Schmorpforge Ta-Sa Software
		52	Repository>, at L<http://anyevent.schmorp.de>, for more info.
45		53
46	=head1 WHY YOU SHOULD USE THIS MODULE (OR NOT)	54	=head1 WHY YOU SHOULD USE THIS MODULE (OR NOT)
47		55
48	Glib, POE, IO::Async, Event... CPAN offers event models by the dozen	56	Glib, POE, IO::Async, Event... CPAN offers event models by the dozen
49	nowadays. So what is different about AnyEvent?	57	nowadays. So what is different about AnyEvent?
…		…
173	my variables are only visible after the statement in which they are	181	my variables are only visible after the statement in which they are
174	declared.	182	declared.
175		183
176	=head2 I/O WATCHERS	184	=head2 I/O WATCHERS
177		185
		186	$w = AnyEvent->io (
		187	fh => <filehandle_or_fileno>,
		188	poll => <"r" or "w">,
		189	cb => <callback>,
		190	);
		191
178	You can create an I/O watcher by calling the C<< AnyEvent->io >> method	192	You can create an I/O watcher by calling the C<< AnyEvent->io >> method
179	with the following mandatory key-value pairs as arguments:	193	with the following mandatory key-value pairs as arguments:
180		194
181	C<fh> is the Perl I<file handle> (I<not> file descriptor) to watch	195	C<fh> is the Perl I<file handle> (or a naked file descriptor) to watch
182	for events (AnyEvent might or might not keep a reference to this file	196	for events (AnyEvent might or might not keep a reference to this file
183	handle). Note that only file handles pointing to things for which	197	handle). Note that only file handles pointing to things for which
184	non-blocking operation makes sense are allowed. This includes sockets,	198	non-blocking operation makes sense are allowed. This includes sockets,
185	most character devices, pipes, fifos and so on, but not for example files	199	most character devices, pipes, fifos and so on, but not for example files
186	or block devices.	200	or block devices.
…		…
211	undef $w;	225	undef $w;
212	});	226	});
213		227
214	=head2 TIME WATCHERS	228	=head2 TIME WATCHERS
215		229
		230	$w = AnyEvent->timer (after => <seconds>, cb => <callback>);
		231
		232	$w = AnyEvent->timer (
		233	after => <fractional_seconds>,
		234	interval => <fractional_seconds>,
		235	cb => <callback>,
		236	);
		237
216	You can create a time watcher by calling the C<< AnyEvent->timer >>	238	You can create a time watcher by calling the C<< AnyEvent->timer >>
217	method with the following mandatory arguments:	239	method with the following mandatory arguments:
218		240
219	C<after> specifies after how many seconds (fractional values are	241	C<after> specifies after how many seconds (fractional values are
220	supported) the callback should be invoked. C<cb> is the callback to invoke	242	supported) the callback should be invoked. C<cb> is the callback to invoke
…		…
341	might affect timers and time-outs.	363	might affect timers and time-outs.
342		364
343	When this is the case, you can call this method, which will update the	365	When this is the case, you can call this method, which will update the
344	event loop's idea of "current time".	366	event loop's idea of "current time".
345		367
		368	A typical example would be a script in a web server (e.g. C<mod_perl>) -
		369	when mod_perl executes the script, then the event loop will have the wrong
		370	idea about the "current time" (being potentially far in the past, when the
		371	script ran the last time). In that case you should arrange a call to C<<
		372	AnyEvent->now_update >> each time the web server process wakes up again
		373	(e.g. at the start of your script, or in a handler).
		374
346	Note that updating the time I<might> cause some events to be handled.	375	Note that updating the time I<might> cause some events to be handled.
347		376
348	=back	377	=back
349		378
350	=head2 SIGNAL WATCHERS	379	=head2 SIGNAL WATCHERS
		380
		381	$w = AnyEvent->signal (signal => <uppercase_signal_name>, cb => <callback>);
351		382
352	You can watch for signals using a signal watcher, C<signal> is the signal	383	You can watch for signals using a signal watcher, C<signal> is the signal
353	I<name> in uppercase and without any C<SIG> prefix, C<cb> is the Perl	384	I<name> in uppercase and without any C<SIG> prefix, C<cb> is the Perl
354	callback to be invoked whenever a signal occurs.	385	callback to be invoked whenever a signal occurs.
355		386
…		…
361	invocation, and callback invocation will be synchronous. Synchronous means	392	invocation, and callback invocation will be synchronous. Synchronous means
362	that it might take a while until the signal gets handled by the process,	393	that it might take a while until the signal gets handled by the process,
363	but it is guaranteed not to interrupt any other callbacks.	394	but it is guaranteed not to interrupt any other callbacks.
364		395
365	The main advantage of using these watchers is that you can share a signal	396	The main advantage of using these watchers is that you can share a signal
366	between multiple watchers.	397	between multiple watchers, and AnyEvent will ensure that signals will not
		398	interrupt your program at bad times.
367		399
368	This watcher might use C<%SIG>, so programs overwriting those signals	400	This watcher might use C<%SIG> (depending on the event loop used),
369	directly will likely not work correctly.	401	so programs overwriting those signals directly will likely not work
		402	correctly.
370		403
371	Example: exit on SIGINT	404	Example: exit on SIGINT
372		405
373	my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });	406	my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });
374		407
		408	=head3 Restart Behaviour
		409
		410	While restart behaviour is up to the event loop implementation, most will
		411	not restart syscalls (that includes L<Async::Interrupt> and AnyEvent's
		412	pure perl implementation).
		413
		414	=head3 Safe/Unsafe Signals
		415
		416	Perl signals can be either "safe" (synchronous to opcode handling) or
		417	"unsafe" (asynchronous) - the former might get delayed indefinitely, the
		418	latter might corrupt your memory.
		419
		420	AnyEvent signal handlers are, in addition, synchronous to the event loop,
		421	i.e. they will not interrupt your running perl program but will only be
		422	called as part of the normal event handling (just like timer, I/O etc.
		423	callbacks, too).
		424
		425	=head3 Signal Races, Delays and Workarounds
		426
		427	Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support attaching
		428	callbacks to signals in a generic way, which is a pity, as you cannot
		429	do race-free signal handling in perl, requiring C libraries for
		430	this. AnyEvent will try to do it's best, which means in some cases,
		431	signals will be delayed. The maximum time a signal might be delayed is
		432	specified in C<$AnyEvent::MAX_SIGNAL_LATENCY> (default: 10 seconds). This
		433	variable can be changed only before the first signal watcher is created,
		434	and should be left alone otherwise. This variable determines how often
		435	AnyEvent polls for signals (in case a wake-up was missed). Higher values
		436	will cause fewer spurious wake-ups, which is better for power and CPU
		437	saving.
		438
		439	All these problems can be avoided by installing the optional
		440	L<Async::Interrupt> module, which works with most event loops. It will not
		441	work with inherently broken event loops such as L<Event> or L<Event::Lib>
		442	(and not with L<POE> currently, as POE does it's own workaround with
		443	one-second latency). For those, you just have to suffer the delays.
		444
375	=head2 CHILD PROCESS WATCHERS	445	=head2 CHILD PROCESS WATCHERS
376		446
		447	$w = AnyEvent->child (pid => <process id>, cb => <callback>);
		448
377	You can also watch on a child process exit and catch its exit status.	449	You can also watch on a child process exit and catch its exit status.
378		450
379	The child process is specified by the C<pid> argument (if set to C<0>, it	451	The child process is specified by the C<pid> argument (one some backends,
380	watches for any child process exit). The watcher will triggered only when	452	using C<0> watches for any child process exit, on others this will
381	the child process has finished and an exit status is available, not on	453	croak). The watcher will be triggered only when the child process has
382	any trace events (stopped/continued).	454	finished and an exit status is available, not on any trace events
		455	(stopped/continued).
383		456
384	The callback will be called with the pid and exit status (as returned by	457	The callback will be called with the pid and exit status (as returned by
385	waitpid), so unlike other watcher types, you I<can> rely on child watcher	458	waitpid), so unlike other watcher types, you I<can> rely on child watcher
386	callback arguments.	459	callback arguments.
387		460
…		…
392		465
393	There is a slight catch to child watchers, however: you usually start them	466	There is a slight catch to child watchers, however: you usually start them
394	I<after> the child process was created, and this means the process could	467	I<after> the child process was created, and this means the process could
395	have exited already (and no SIGCHLD will be sent anymore).	468	have exited already (and no SIGCHLD will be sent anymore).
396		469
397	Not all event models handle this correctly (POE doesn't), but even for	470	Not all event models handle this correctly (neither POE nor IO::Async do,
		471	see their AnyEvent::Impl manpages for details), but even for event models
398	event models that I<do> handle this correctly, they usually need to be	472	that I<do> handle this correctly, they usually need to be loaded before
399	loaded before the process exits (i.e. before you fork in the first place).	473	the process exits (i.e. before you fork in the first place). AnyEvent's
		474	pure perl event loop handles all cases correctly regardless of when you
		475	start the watcher.
400		476
401	This means you cannot create a child watcher as the very first thing in an	477	This means you cannot create a child watcher as the very first
402	AnyEvent program, you I<have> to create at least one watcher before you	478	thing in an AnyEvent program, you I<have> to create at least one
403	C<fork> the child (alternatively, you can call C<AnyEvent::detect>).	479	watcher before you C<fork> the child (alternatively, you can call
		480	C<AnyEvent::detect>).
		481
		482	As most event loops do not support waiting for child events, they will be
		483	emulated by AnyEvent in most cases, in which the latency and race problems
		484	mentioned in the description of signal watchers apply.
404		485
405	Example: fork a process and wait for it	486	Example: fork a process and wait for it
406		487
407	my $done = AnyEvent->condvar;	488	my $done = AnyEvent->condvar;
408		489
…		…
420	# do something else, then wait for process exit	501	# do something else, then wait for process exit
421	$done->recv;	502	$done->recv;
422		503
423	=head2 IDLE WATCHERS	504	=head2 IDLE WATCHERS
424		505
425	Sometimes there is a need to do something, but it is not so important	506	$w = AnyEvent->idle (cb => <callback>);
426	to do it instantly, but only when there is nothing better to do. This
427	"nothing better to do" is usually defined to be "no other events need
428	attention by the event loop".
429		507
430	Idle watchers ideally get invoked when the event loop has nothing	508	Repeatedly invoke the callback after the process becomes idle, until
431	better to do, just before it would block the process to wait for new	509	either the watcher is destroyed or new events have been detected.
432	events. Instead of blocking, the idle watcher is invoked.
433		510
434	Most event loops unfortunately do not really support idle watchers (only	511	Idle watchers are useful when there is a need to do something, but it
		512	is not so important (or wise) to do it instantly. The callback will be
		513	invoked only when there is "nothing better to do", which is usually
		514	defined as "all outstanding events have been handled and no new events
		515	have been detected". That means that idle watchers ideally get invoked
		516	when the event loop has just polled for new events but none have been
		517	detected. Instead of blocking to wait for more events, the idle watchers
		518	will be invoked.
		519
		520	Unfortunately, most event loops do not really support idle watchers (only
435	EV, Event and Glib do it in a usable fashion) - for the rest, AnyEvent	521	EV, Event and Glib do it in a usable fashion) - for the rest, AnyEvent
436	will simply call the callback "from time to time".	522	will simply call the callback "from time to time".
437		523
438	Example: read lines from STDIN, but only process them when the	524	Example: read lines from STDIN, but only process them when the
439	program is otherwise idle:	525	program is otherwise idle:
…		…
455	});	541	});
456	});	542	});
457		543
458	=head2 CONDITION VARIABLES	544	=head2 CONDITION VARIABLES
459		545
		546	$cv = AnyEvent->condvar;
		547
		548	$cv->send (<list>);
		549	my @res = $cv->recv;
		550
460	If you are familiar with some event loops you will know that all of them	551	If you are familiar with some event loops you will know that all of them
461	require you to run some blocking "loop", "run" or similar function that	552	require you to run some blocking "loop", "run" or similar function that
462	will actively watch for new events and call your callbacks.	553	will actively watch for new events and call your callbacks.
463		554
464	AnyEvent is different, it expects somebody else to run the event loop and	555	AnyEvent is slightly different: it expects somebody else to run the event
465	will only block when necessary (usually when told by the user).	556	loop and will only block when necessary (usually when told by the user).
466		557
467	The instrument to do that is called a "condition variable", so called	558	The instrument to do that is called a "condition variable", so called
468	because they represent a condition that must become true.	559	because they represent a condition that must become true.
469		560
		561	Now is probably a good time to look at the examples further below.
		562
470	Condition variables can be created by calling the C<< AnyEvent->condvar	563	Condition variables can be created by calling the C<< AnyEvent->condvar
471	>> method, usually without arguments. The only argument pair allowed is	564	>> method, usually without arguments. The only argument pair allowed is
472
473	C<cb>, which specifies a callback to be called when the condition variable	565	C<cb>, which specifies a callback to be called when the condition variable
474	becomes true, with the condition variable as the first argument (but not	566	becomes true, with the condition variable as the first argument (but not
475	the results).	567	the results).
476		568
477	After creation, the condition variable is "false" until it becomes "true"	569	After creation, the condition variable is "false" until it becomes "true"
…		…
482	Condition variables are similar to callbacks, except that you can	574	Condition variables are similar to callbacks, except that you can
483	optionally wait for them. They can also be called merge points - points	575	optionally wait for them. They can also be called merge points - points
484	in time where multiple outstanding events have been processed. And yet	576	in time where multiple outstanding events have been processed. And yet
485	another way to call them is transactions - each condition variable can be	577	another way to call them is transactions - each condition variable can be
486	used to represent a transaction, which finishes at some point and delivers	578	used to represent a transaction, which finishes at some point and delivers
487	a result.	579	a result. And yet some people know them as "futures" - a promise to
		580	compute/deliver something that you can wait for.
488		581
489	Condition variables are very useful to signal that something has finished,	582	Condition variables are very useful to signal that something has finished,
490	for example, if you write a module that does asynchronous http requests,	583	for example, if you write a module that does asynchronous http requests,
491	then a condition variable would be the ideal candidate to signal the	584	then a condition variable would be the ideal candidate to signal the
492	availability of results. The user can either act when the callback is	585	availability of results. The user can either act when the callback is
…		…
526	after => 1,	619	after => 1,
527	cb => sub { $result_ready->send },	620	cb => sub { $result_ready->send },
528	);	621	);
529		622
530	# this "blocks" (while handling events) till the callback	623	# this "blocks" (while handling events) till the callback
531	# calls send	624	# calls ->send
532	$result_ready->recv;	625	$result_ready->recv;
533		626
534	Example: wait for a timer, but take advantage of the fact that	627	Example: wait for a timer, but take advantage of the fact that condition
535	condition variables are also code references.	628	variables are also callable directly.
536		629
537	my $done = AnyEvent->condvar;	630	my $done = AnyEvent->condvar;
538	my $delay = AnyEvent->timer (after => 5, cb => $done);	631	my $delay = AnyEvent->timer (after => 5, cb => $done);
539	$done->recv;	632	$done->recv;
540		633
…		…
546		639
547	...	640	...
548		641
549	my @info = $couchdb->info->recv;	642	my @info = $couchdb->info->recv;
550		643
551	And this is how you would just ste a callback to be called whenever the	644	And this is how you would just set a callback to be called whenever the
552	results are available:	645	results are available:
553		646
554	$couchdb->info->cb (sub {	647	$couchdb->info->cb (sub {
555	my @info = $_[0]->recv;	648	my @info = $_[0]->recv;
556	});	649	});
…		…
574	immediately from within send.	667	immediately from within send.
575		668
576	Any arguments passed to the C<send> call will be returned by all	669	Any arguments passed to the C<send> call will be returned by all
577	future C<< ->recv >> calls.	670	future C<< ->recv >> calls.
578		671
579	Condition variables are overloaded so one can call them directly	672	Condition variables are overloaded so one can call them directly (as if
580	(as a code reference). Calling them directly is the same as calling	673	they were a code reference). Calling them directly is the same as calling
581	C<send>. Note, however, that many C-based event loops do not handle	674	C<send>.
582	overloading, so as tempting as it may be, passing a condition variable
583	instead of a callback does not work. Both the pure perl and EV loops
584	support overloading, however, as well as all functions that use perl to
585	invoke a callback (as in L<AnyEvent::Socket> and L<AnyEvent::DNS> for
586	example).
587		675
588	=item $cv->croak ($error)	676	=item $cv->croak ($error)
589		677
590	Similar to send, but causes all call's to C<< ->recv >> to invoke	678	Similar to send, but causes all call's to C<< ->recv >> to invoke
591	C<Carp::croak> with the given error message/object/scalar.	679	C<Carp::croak> with the given error message/object/scalar.
592		680
593	This can be used to signal any errors to the condition variable	681	This can be used to signal any errors to the condition variable
594	user/consumer.	682	user/consumer. Doing it this way instead of calling C<croak> directly
		683	delays the error detetcion, but has the overwhelmign advantage that it
		684	diagnoses the error at the place where the result is expected, and not
		685	deep in some event clalback without connection to the actual code causing
		686	the problem.
595		687
596	=item $cv->begin ([group callback])	688	=item $cv->begin ([group callback])
597		689
598	=item $cv->end	690	=item $cv->end
599
600	These two methods are EXPERIMENTAL and MIGHT CHANGE.
601		691
602	These two methods can be used to combine many transactions/events into	692	These two methods can be used to combine many transactions/events into
603	one. For example, a function that pings many hosts in parallel might want	693	one. For example, a function that pings many hosts in parallel might want
604	to use a condition variable for the whole process.	694	to use a condition variable for the whole process.
605		695
606	Every call to C<< ->begin >> will increment a counter, and every call to	696	Every call to C<< ->begin >> will increment a counter, and every call to
607	C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end	697	C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end
608	>>, the (last) callback passed to C<begin> will be executed. That callback	698	>>, the (last) callback passed to C<begin> will be executed, passing the
609	is I<supposed> to call C<< ->send >>, but that is not required. If no	699	condvar as first argument. That callback is I<supposed> to call C<< ->send
610	callback was set, C<send> will be called without any arguments.	700	>>, but that is not required. If no group callback was set, C<send> will
		701	be called without any arguments.
611		702
612	Let's clarify this with the ping example:	703	You can think of C<< $cv->send >> giving you an OR condition (one call
		704	sends), while C<< $cv->begin >> and C<< $cv->end >> giving you an AND
		705	condition (all C<begin> calls must be C<end>'ed before the condvar sends).
		706
		707	Let's start with a simple example: you have two I/O watchers (for example,
		708	STDOUT and STDERR for a program), and you want to wait for both streams to
		709	close before activating a condvar:
613		710
614	my $cv = AnyEvent->condvar;	711	my $cv = AnyEvent->condvar;
615		712
		713	$cv->begin; # first watcher
		714	my $w1 = AnyEvent->io (fh => $fh1, cb => sub {
		715	defined sysread $fh1, my $buf, 4096
		716	or $cv->end;
		717	});
		718
		719	$cv->begin; # second watcher
		720	my $w2 = AnyEvent->io (fh => $fh2, cb => sub {
		721	defined sysread $fh2, my $buf, 4096
		722	or $cv->end;
		723	});
		724
		725	$cv->recv;
		726
		727	This works because for every event source (EOF on file handle), there is
		728	one call to C<begin>, so the condvar waits for all calls to C<end> before
		729	sending.
		730
		731	The ping example mentioned above is slightly more complicated, as the
		732	there are results to be passwd back, and the number of tasks that are
		733	begung can potentially be zero:
		734
		735	my $cv = AnyEvent->condvar;
		736
616	my %result;	737	my %result;
617	$cv->begin (sub { $cv->send (\%result) });	738	$cv->begin (sub { shift->send (\%result) });
618		739
619	for my $host (@list_of_hosts) {	740	for my $host (@list_of_hosts) {
620	$cv->begin;	741	$cv->begin;
621	ping_host_then_call_callback $host, sub {	742	ping_host_then_call_callback $host, sub {
622	$result{$host} = ...;	743	$result{$host} = ...;
…		…
637	loop, which serves two important purposes: first, it sets the callback	758	loop, which serves two important purposes: first, it sets the callback
638	to be called once the counter reaches C<0>, and second, it ensures that	759	to be called once the counter reaches C<0>, and second, it ensures that
639	C<send> is called even when C<no> hosts are being pinged (the loop	760	C<send> is called even when C<no> hosts are being pinged (the loop
640	doesn't execute once).	761	doesn't execute once).
641		762
642	This is the general pattern when you "fan out" into multiple subrequests:	763	This is the general pattern when you "fan out" into multiple (but
643	use an outer C<begin>/C<end> pair to set the callback and ensure C<end>	764	potentially none) subrequests: use an outer C<begin>/C<end> pair to set
644	is called at least once, and then, for each subrequest you start, call	765	the callback and ensure C<end> is called at least once, and then, for each
645	C<begin> and for each subrequest you finish, call C<end>.	766	subrequest you start, call C<begin> and for each subrequest you finish,
		767	call C<end>.
646		768
647	=back	769	=back
648		770
649	=head3 METHODS FOR CONSUMERS	771	=head3 METHODS FOR CONSUMERS
650		772
…		…
666	function will call C<croak>.	788	function will call C<croak>.
667		789
668	In list context, all parameters passed to C<send> will be returned,	790	In list context, all parameters passed to C<send> will be returned,
669	in scalar context only the first one will be returned.	791	in scalar context only the first one will be returned.
670		792
		793	Note that doing a blocking wait in a callback is not supported by any
		794	event loop, that is, recursive invocation of a blocking C<< ->recv
		795	>> is not allowed, and the C<recv> call will C<croak> if such a
		796	condition is detected. This condition can be slightly loosened by using
		797	L<Coro::AnyEvent>, which allows you to do a blocking C<< ->recv >> from
		798	any thread that doesn't run the event loop itself.
		799
671	Not all event models support a blocking wait - some die in that case	800	Not all event models support a blocking wait - some die in that case
672	(programs might want to do that to stay interactive), so I<if you are	801	(programs might want to do that to stay interactive), so I<if you are
673	using this from a module, never require a blocking wait>, but let the	802	using this from a module, never require a blocking wait>. Instead, let the
674	caller decide whether the call will block or not (for example, by coupling	803	caller decide whether the call will block or not (for example, by coupling
675	condition variables with some kind of request results and supporting	804	condition variables with some kind of request results and supporting
676	callbacks so the caller knows that getting the result will not block,	805	callbacks so the caller knows that getting the result will not block,
677	while still supporting blocking waits if the caller so desires).	806	while still supporting blocking waits if the caller so desires).
678		807
679	Another reason I<never> to C<< ->recv >> in a module is that you cannot
680	sensibly have two C<< ->recv >>'s in parallel, as that would require
681	multiple interpreters or coroutines/threads, none of which C<AnyEvent>
682	can supply.
683
684	The L<Coro> module, however, I<can> and I<does> supply coroutines and, in
685	fact, L<Coro::AnyEvent> replaces AnyEvent's condvars by coroutine-safe
686	versions and also integrates coroutines into AnyEvent, making blocking
687	C<< ->recv >> calls perfectly safe as long as they are done from another
688	coroutine (one that doesn't run the event loop).
689
690	You can ensure that C<< -recv >> never blocks by setting a callback and	808	You can ensure that C<< -recv >> never blocks by setting a callback and
691	only calling C<< ->recv >> from within that callback (or at a later	809	only calling C<< ->recv >> from within that callback (or at a later
692	time). This will work even when the event loop does not support blocking	810	time). This will work even when the event loop does not support blocking
693	waits otherwise.	811	waits otherwise.
694		812
…		…
700	=item $cb = $cv->cb ($cb->($cv))	818	=item $cb = $cv->cb ($cb->($cv))
701		819
702	This is a mutator function that returns the callback set and optionally	820	This is a mutator function that returns the callback set and optionally
703	replaces it before doing so.	821	replaces it before doing so.
704		822
705	The callback will be called when the condition becomes "true", i.e. when	823	The callback will be called when the condition becomes (or already was)
706	C<send> or C<croak> are called, with the only argument being the condition	824	"true", i.e. when C<send> or C<croak> are called (or were called), with
707	variable itself. Calling C<recv> inside the callback or at any later time	825	the only argument being the condition variable itself. Calling C<recv>
708	is guaranteed not to block.	826	inside the callback or at any later time is guaranteed not to block.
709		827
710	=back	828	=back
711		829
		830	=head1 SUPPORTED EVENT LOOPS/BACKENDS
		831
		832	The available backend classes are (every class has its own manpage):
		833
		834	=over 4
		835
		836	=item Backends that are autoprobed when no other event loop can be found.
		837
		838	EV is the preferred backend when no other event loop seems to be in
		839	use. If EV is not installed, then AnyEvent will fall back to its own
		840	pure-perl implementation, which is available everywhere as it comes with
		841	AnyEvent itself.
		842
		843	AnyEvent::Impl::EV based on EV (interface to libev, best choice).
		844	AnyEvent::Impl::Perl pure-perl implementation, fast and portable.
		845
		846	=item Backends that are transparently being picked up when they are used.
		847
		848	These will be used when they are currently loaded when the first watcher
		849	is created, in which case it is assumed that the application is using
		850	them. This means that AnyEvent will automatically pick the right backend
		851	when the main program loads an event module before anything starts to
		852	create watchers. Nothing special needs to be done by the main program.
		853
		854	AnyEvent::Impl::Event based on Event, very stable, few glitches.
		855	AnyEvent::Impl::Glib based on Glib, slow but very stable.
		856	AnyEvent::Impl::Tk based on Tk, very broken.
		857	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
		858	AnyEvent::Impl::POE based on POE, very slow, some limitations.
		859	AnyEvent::Impl::Irssi used when running within irssi.
		860
		861	=item Backends with special needs.
		862
		863	Qt requires the Qt::Application to be instantiated first, but will
		864	otherwise be picked up automatically. As long as the main program
		865	instantiates the application before any AnyEvent watchers are created,
		866	everything should just work.
		867
		868	AnyEvent::Impl::Qt based on Qt.
		869
		870	Support for IO::Async can only be partial, as it is too broken and
		871	architecturally limited to even support the AnyEvent API. It also
		872	is the only event loop that needs the loop to be set explicitly, so
		873	it can only be used by a main program knowing about AnyEvent. See
		874	L<AnyEvent::Impl::Async> for the gory details.
		875
		876	AnyEvent::Impl::IOAsync based on IO::Async, cannot be autoprobed.
		877
		878	=item Event loops that are indirectly supported via other backends.
		879
		880	Some event loops can be supported via other modules:
		881
		882	There is no direct support for WxWidgets (L<Wx>) or L<Prima>.
		883
		884	B<WxWidgets> has no support for watching file handles. However, you can
		885	use WxWidgets through the POE adaptor, as POE has a Wx backend that simply
		886	polls 20 times per second, which was considered to be too horrible to even
		887	consider for AnyEvent.
		888
		889	B<Prima> is not supported as nobody seems to be using it, but it has a POE
		890	backend, so it can be supported through POE.
		891
		892	AnyEvent knows about both L<Prima> and L<Wx>, however, and will try to
		893	load L<POE> when detecting them, in the hope that POE will pick them up,
		894	in which case everything will be automatic.
		895
		896	=back
		897
712	=head1 GLOBAL VARIABLES AND FUNCTIONS	898	=head1 GLOBAL VARIABLES AND FUNCTIONS
713		899
		900	These are not normally required to use AnyEvent, but can be useful to
		901	write AnyEvent extension modules.
		902
714	=over 4	903	=over 4
715		904
716	=item $AnyEvent::MODEL	905	=item $AnyEvent::MODEL
717		906
718	Contains C<undef> until the first watcher is being created. Then it	907	Contains C<undef> until the first watcher is being created, before the
		908	backend has been autodetected.
		909
719	contains the event model that is being used, which is the name of the	910	Afterwards it contains the event model that is being used, which is the
720	Perl class implementing the model. This class is usually one of the	911	name of the Perl class implementing the model. This class is usually one
721	C<AnyEvent::Impl:xxx> modules, but can be any other class in the case	912	of the C<AnyEvent::Impl:xxx> modules, but can be any other class in the
722	AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode>).	913	case AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode> it
723		914	will be C<urxvt::anyevent>).
724	The known classes so far are:
725
726	AnyEvent::Impl::EV based on EV (an interface to libev, best choice).
727	AnyEvent::Impl::Event based on Event, second best choice.
728	AnyEvent::Impl::Perl pure-perl implementation, fast and portable.
729	AnyEvent::Impl::Glib based on Glib, third-best choice.
730	AnyEvent::Impl::Tk based on Tk, very bad choice.
731	AnyEvent::Impl::Qt based on Qt, cannot be autoprobed (see its docs).
732	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
733	AnyEvent::Impl::POE based on POE, not generic enough for full support.
734
735	There is no support for WxWidgets, as WxWidgets has no support for
736	watching file handles. However, you can use WxWidgets through the
737	POE Adaptor, as POE has a Wx backend that simply polls 20 times per
738	second, which was considered to be too horrible to even consider for
739	AnyEvent. Likewise, other POE backends can be used by AnyEvent by using
740	it's adaptor.
741
742	AnyEvent knows about L<Prima> and L<Wx> and will try to use L<POE> when
743	autodetecting them.
744		915
745	=item AnyEvent::detect	916	=item AnyEvent::detect
746		917
747	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model	918	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model
748	if necessary. You should only call this function right before you would	919	if necessary. You should only call this function right before you would
749	have created an AnyEvent watcher anyway, that is, as late as possible at	920	have created an AnyEvent watcher anyway, that is, as late as possible at
750	runtime.	921	runtime, and not e.g. while initialising of your module.
		922
		923	If you need to do some initialisation before AnyEvent watchers are
		924	created, use C<post_detect>.
751		925
752	=item $guard = AnyEvent::post_detect { BLOCK }	926	=item $guard = AnyEvent::post_detect { BLOCK }
753		927
754	Arranges for the code block to be executed as soon as the event model is	928	Arranges for the code block to be executed as soon as the event model is
755	autodetected (or immediately if this has already happened).	929	autodetected (or immediately if this has already happened).
756		930
		931	The block will be executed I<after> the actual backend has been detected
		932	(C<$AnyEvent::MODEL> is set), but I<before> any watchers have been
		933	created, so it is possible to e.g. patch C<@AnyEvent::ISA> or do
		934	other initialisations - see the sources of L<AnyEvent::Strict> or
		935	L<AnyEvent::AIO> to see how this is used.
		936
		937	The most common usage is to create some global watchers, without forcing
		938	event module detection too early, for example, L<AnyEvent::AIO> creates
		939	and installs the global L<IO::AIO> watcher in a C<post_detect> block to
		940	avoid autodetecting the event module at load time.
		941
757	If called in scalar or list context, then it creates and returns an object	942	If called in scalar or list context, then it creates and returns an object
758	that automatically removes the callback again when it is destroyed. See	943	that automatically removes the callback again when it is destroyed (or
		944	C<undef> when the hook was immediately executed). See L<AnyEvent::AIO> for
759	L<Coro::BDB> for a case where this is useful.	945	a case where this is useful.
		946
		947	Example: Create a watcher for the IO::AIO module and store it in
		948	C<$WATCHER>. Only do so after the event loop is initialised, though.
		949
		950	our WATCHER;
		951
		952	my $guard = AnyEvent::post_detect {
		953	$WATCHER = AnyEvent->io (fh => IO::AIO::poll_fileno, poll => 'r', cb => \&IO::AIO::poll_cb);
		954	};
		955
		956	# the ||= is important in case post_detect immediately runs the block,
		957	# as to not clobber the newly-created watcher. assigning both watcher and
		958	# post_detect guard to the same variable has the advantage of users being
		959	# able to just C<undef $WATCHER> if the watcher causes them grief.
		960
		961	$WATCHER ||= $guard;
760		962
761	=item @AnyEvent::post_detect	963	=item @AnyEvent::post_detect
762		964
763	If there are any code references in this array (you can C<push> to it	965	If there are any code references in this array (you can C<push> to it
764	before or after loading AnyEvent), then they will called directly after	966	before or after loading AnyEvent), then they will called directly after
765	the event loop has been chosen.	967	the event loop has been chosen.
766		968
767	You should check C<$AnyEvent::MODEL> before adding to this array, though:	969	You should check C<$AnyEvent::MODEL> before adding to this array, though:
768	if it contains a true value then the event loop has already been detected,	970	if it is defined then the event loop has already been detected, and the
769	and the array will be ignored.	971	array will be ignored.
770		972
771	Best use C<AnyEvent::post_detect { BLOCK }> instead.	973	Best use C<AnyEvent::post_detect { BLOCK }> when your application allows
		974	it, as it takes care of these details.
		975
		976	This variable is mainly useful for modules that can do something useful
		977	when AnyEvent is used and thus want to know when it is initialised, but do
		978	not need to even load it by default. This array provides the means to hook
		979	into AnyEvent passively, without loading it.
		980
		981	Example: To load Coro::AnyEvent whenever Coro and AnyEvent are used
		982	together, you could put this into Coro (this is the actual code used by
		983	Coro to accomplish this):
		984
		985	if (defined $AnyEvent::MODEL) {
		986	# AnyEvent already initialised, so load Coro::AnyEvent
		987	require Coro::AnyEvent;
		988	} else {
		989	# AnyEvent not yet initialised, so make sure to load Coro::AnyEvent
		990	# as soon as it is
		991	push @AnyEvent::post_detect, sub { require Coro::AnyEvent };
		992	}
772		993
773	=back	994	=back
774		995
775	=head1 WHAT TO DO IN A MODULE	996	=head1 WHAT TO DO IN A MODULE
776		997
…		…
831		1052
832		1053
833	=head1 OTHER MODULES	1054	=head1 OTHER MODULES
834		1055
835	The following is a non-exhaustive list of additional modules that use	1056	The following is a non-exhaustive list of additional modules that use
836	AnyEvent and can therefore be mixed easily with other AnyEvent modules	1057	AnyEvent as a client and can therefore be mixed easily with other AnyEvent
837	in the same program. Some of the modules come with AnyEvent, some are	1058	modules and other event loops in the same program. Some of the modules
838	available via CPAN.	1059	come with AnyEvent, most are available via CPAN.
839		1060
840	=over 4	1061	=over 4
841		1062
842	=item L<AnyEvent::Util>	1063	=item L<AnyEvent::Util>
843		1064
…		…
852		1073
853	=item L<AnyEvent::Handle>	1074	=item L<AnyEvent::Handle>
854		1075
855	Provide read and write buffers, manages watchers for reads and writes,	1076	Provide read and write buffers, manages watchers for reads and writes,
856	supports raw and formatted I/O, I/O queued and fully transparent and	1077	supports raw and formatted I/O, I/O queued and fully transparent and
857	non-blocking SSL/TLS.	1078	non-blocking SSL/TLS (via L<AnyEvent::TLS>.
858		1079
859	=item L<AnyEvent::DNS>	1080	=item L<AnyEvent::DNS>
860		1081
861	Provides rich asynchronous DNS resolver capabilities.	1082	Provides rich asynchronous DNS resolver capabilities.
862		1083
…		…
890		1111
891	=item L<AnyEvent::GPSD>	1112	=item L<AnyEvent::GPSD>
892		1113
893	A non-blocking interface to gpsd, a daemon delivering GPS information.	1114	A non-blocking interface to gpsd, a daemon delivering GPS information.
894		1115
		1116	=item L<AnyEvent::IRC>
		1117
		1118	AnyEvent based IRC client module family (replacing the older Net::IRC3).
		1119
		1120	=item L<AnyEvent::XMPP>
		1121
		1122	AnyEvent based XMPP (Jabber protocol) module family (replacing the older
		1123	Net::XMPP2>.
		1124
895	=item L<AnyEvent::IGS>	1125	=item L<AnyEvent::IGS>
896		1126
897	A non-blocking interface to the Internet Go Server protocol (used by	1127	A non-blocking interface to the Internet Go Server protocol (used by
898	L<App::IGS>).	1128	L<App::IGS>).
899		1129
900	=item L<AnyEvent::IRC>
901
902	AnyEvent based IRC client module family (replacing the older Net::IRC3).
903
904	=item L<Net::XMPP2>
905
906	AnyEvent based XMPP (Jabber protocol) module family.
907
908	=item L<Net::FCP>	1130	=item L<Net::FCP>
909		1131
910	AnyEvent-based implementation of the Freenet Client Protocol, birthplace	1132	AnyEvent-based implementation of the Freenet Client Protocol, birthplace
911	of AnyEvent.	1133	of AnyEvent.
912		1134
…		…
916		1138
917	=item L<Coro>	1139	=item L<Coro>
918		1140
919	Has special support for AnyEvent via L<Coro::AnyEvent>.	1141	Has special support for AnyEvent via L<Coro::AnyEvent>.
920		1142
921	=item L<IO::Lambda>
922
923	The lambda approach to I/O - don't ask, look there. Can use AnyEvent.
924
925	=back	1143	=back
926		1144
927	=cut	1145	=cut
928		1146
929	package AnyEvent;	1147	package AnyEvent;
930		1148
931	no warnings;	1149	# basically a tuned-down version of common::sense
932	use strict qw(vars subs);	1150	sub common_sense {
		1151	# from common:.sense 1.0
		1152	${^WARNING_BITS} = "\xfc\x3f\x33\x00\x0f\xf3\xcf\xc0\xf3\xfc\x33\x00";
		1153	# use strict vars subs - NO UTF-8, as Util.pm doesn't like this atm. (uts46data.pl)
		1154	$^H |= 0x00000600;
		1155	}
933		1156
		1157	BEGIN { AnyEvent::common_sense }
		1158
934	use Carp;	1159	use Carp ();
935		1160
936	our $VERSION = 4.412;	1161	our $VERSION = '5.24';
937	our $MODEL;	1162	our $MODEL;
938		1163
939	our $AUTOLOAD;	1164	our $AUTOLOAD;
940	our @ISA;	1165	our @ISA;
941		1166
942	our @REGISTRY;	1167	our @REGISTRY;
943		1168
944	our $WIN32;	1169	our $VERBOSE;
945		1170
946	BEGIN {	1171	BEGIN {
		1172	eval "sub CYGWIN(){" . (($^O =~ /cygwin/i) *1) . "}";
947	eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }";	1173	eval "sub WIN32 (){" . (($^O =~ /mswin32/i)*1) . "}";
948	eval "sub TAINT(){ " . (${^TAINT}*1) . " }";	1174	eval "sub TAINT (){" . (${^TAINT} *1) . "}";
949		1175
950	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}	1176	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}
951	if ${^TAINT};	1177	if ${^TAINT};
952	}
953		1178
954	our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1;	1179	$VERBOSE = $ENV{PERL_ANYEVENT_VERBOSE}*1;
		1180
		1181	}
		1182
		1183	our $MAX_SIGNAL_LATENCY = 10;
955		1184
956	our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred	1185	our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred
957		1186
958	{	1187	{
959	my $idx;	1188	my $idx;
…		…
961	for reverse split /\s*,\s*/,	1190	for reverse split /\s*,\s*/,
962	$ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";	1191	$ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";
963	}	1192	}
964		1193
965	my @models = (	1194	my @models = (
966	[EV:: => AnyEvent::Impl::EV::],	1195	[EV:: => AnyEvent::Impl::EV:: , 1],
967	[Event:: => AnyEvent::Impl::Event::],
968	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::],	1196	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl:: , 1],
969	# everything below here will not be autoprobed	1197	# everything below here will not (normally) be autoprobed
970	# as the pureperl backend should work everywhere	1198	# as the pureperl backend should work everywhere
971	# and is usually faster	1199	# and is usually faster
		1200	[Event:: => AnyEvent::Impl::Event::, 1],
		1201	[Glib:: => AnyEvent::Impl::Glib:: , 1], # becomes extremely slow with many watchers
		1202	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
		1203	[Irssi:: => AnyEvent::Impl::Irssi::], # Irssi has a bogus "Event" package
972	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles	1204	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
973	[Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers
974	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
975	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program	1205	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program
976	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza	1206	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
977	[Wx:: => AnyEvent::Impl::POE::],	1207	[Wx:: => AnyEvent::Impl::POE::],
978	[Prima:: => AnyEvent::Impl::POE::],	1208	[Prima:: => AnyEvent::Impl::POE::],
		1209	# IO::Async is just too broken - we would need workarounds for its
		1210	# byzantine signal and broken child handling, among others.
		1211	# IO::Async is rather hard to detect, as it doesn't have any
		1212	# obvious default class.
		1213	[IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program
		1214	[IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program
		1215	[IO::Async::Notifier:: => AnyEvent::Impl::IOAsync::], # requires special main program
		1216	[AnyEvent::Impl::IOAsync:: => AnyEvent::Impl::IOAsync::], # requires special main program
979	);	1217	);
980		1218
981	our %method = map +($_ => 1),	1219	our %method = map +($_ => 1),
982	qw(io timer time now now_update signal child idle condvar one_event DESTROY);	1220	qw(io timer time now now_update signal child idle condvar one_event DESTROY);
983		1221
…		…
987	my ($cb) = @_;	1225	my ($cb) = @_;
988		1226
989	if ($MODEL) {	1227	if ($MODEL) {
990	$cb->();	1228	$cb->();
991		1229
992	1	1230	undef
993	} else {	1231	} else {
994	push @post_detect, $cb;	1232	push @post_detect, $cb;
995		1233
996	defined wantarray	1234	defined wantarray
997	? bless \$cb, "AnyEvent::Util::postdetect"	1235	? bless \$cb, "AnyEvent::Util::postdetect"
…		…
1003	@post_detect = grep $_ != ${$_[0]}, @post_detect;	1241	@post_detect = grep $_ != ${$_[0]}, @post_detect;
1004	}	1242	}
1005		1243
1006	sub detect() {	1244	sub detect() {
1007	unless ($MODEL) {	1245	unless ($MODEL) {
1008	no strict 'refs';
1009	local $SIG{__DIE__};	1246	local $SIG{__DIE__};
1010		1247
1011	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {	1248	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {
1012	my $model = "AnyEvent::Impl::$1";	1249	my $model = "AnyEvent::Impl::$1";
1013	if (eval "require $model") {	1250	if (eval "require $model") {
1014	$MODEL = $model;	1251	$MODEL = $model;
1015	warn "AnyEvent: loaded model '$model' (forced by \$PERL_ANYEVENT_MODEL), using it.\n" if $verbose > 1;	1252	warn "AnyEvent: loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.\n" if $VERBOSE >= 2;
1016	} else {	1253	} else {
1017	warn "AnyEvent: unable to load model '$model' (from \$PERL_ANYEVENT_MODEL):\n$@" if $verbose;	1254	warn "AnyEvent: unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@" if $VERBOSE;
1018	}	1255	}
1019	}	1256	}
1020		1257
1021	# check for already loaded models	1258	# check for already loaded models
1022	unless ($MODEL) {	1259	unless ($MODEL) {
1023	for (@REGISTRY, @models) {	1260	for (@REGISTRY, @models) {
1024	my ($package, $model) = @$_;	1261	my ($package, $model) = @$_;
1025	if (${"$package\::VERSION"} > 0) {	1262	if (${"$package\::VERSION"} > 0) {
1026	if (eval "require $model") {	1263	if (eval "require $model") {
1027	$MODEL = $model;	1264	$MODEL = $model;
1028	warn "AnyEvent: autodetected model '$model', using it.\n" if $verbose > 1;	1265	warn "AnyEvent: autodetected model '$model', using it.\n" if $VERBOSE >= 2;
1029	last;	1266	last;
1030	}	1267	}
1031	}	1268	}
1032	}	1269	}
1033		1270
1034	unless ($MODEL) {	1271	unless ($MODEL) {
1035	# try to load a model	1272	# try to autoload a model
1036
1037	for (@REGISTRY, @models) {	1273	for (@REGISTRY, @models) {
1038	my ($package, $model) = @$_;	1274	my ($package, $model, $autoload) = @$_;
		1275	if (
		1276	$autoload
1039	if (eval "require $package"	1277	and eval "require $package"
1040	and ${"$package\::VERSION"} > 0	1278	and ${"$package\::VERSION"} > 0
1041	and eval "require $model") {	1279	and eval "require $model"
		1280	) {
1042	$MODEL = $model;	1281	$MODEL = $model;
1043	warn "AnyEvent: autoprobed model '$model', using it.\n" if $verbose > 1;	1282	warn "AnyEvent: autoloaded model '$model', using it.\n" if $VERBOSE >= 2;
1044	last;	1283	last;
1045	}	1284	}
1046	}	1285	}
1047		1286
1048	$MODEL	1287	$MODEL
…		…
1064		1303
1065	sub AUTOLOAD {	1304	sub AUTOLOAD {
1066	(my $func = $AUTOLOAD) =~ s/.*://;	1305	(my $func = $AUTOLOAD) =~ s/.*://;
1067		1306
1068	$method{$func}	1307	$method{$func}
1069	or croak "$func: not a valid method for AnyEvent objects";	1308	or Carp::croak "$func: not a valid method for AnyEvent objects";
1070		1309
1071	detect unless $MODEL;	1310	detect unless $MODEL;
1072		1311
1073	my $class = shift;	1312	my $class = shift;
1074	$class->$func (@_);	1313	$class->$func (@_);
1075	}	1314	}
1076		1315
1077	# utility function to dup a filehandle. this is used by many backends	1316	# utility function to dup a filehandle. this is used by many backends
1078	# to support binding more than one watcher per filehandle (they usually	1317	# to support binding more than one watcher per filehandle (they usually
1079	# allow only one watcher per fd, so we dup it to get a different one).	1318	# allow only one watcher per fd, so we dup it to get a different one).
1080	sub _dupfh($$$$) {	1319	sub _dupfh($$;$$) {
1081	my ($poll, $fh, $r, $w) = @_;	1320	my ($poll, $fh, $r, $w) = @_;
1082		1321
1083	# cygwin requires the fh mode to be matching, unix doesn't	1322	# cygwin requires the fh mode to be matching, unix doesn't
1084	my ($rw, $mode) = $poll eq "r" ? ($r, "<")	1323	my ($rw, $mode) = $poll eq "r" ? ($r, "<&") : ($w, ">&");
1085	: $poll eq "w" ? ($w, ">")
1086	: Carp::croak "AnyEvent->io requires poll set to either 'r' or 'w'";
1087		1324
1088	open my $fh2, "$mode&" . fileno $fh	1325	open my $fh2, $mode, $fh
1089	or die "cannot dup() filehandle: $!,";	1326	or die "AnyEvent->io: cannot dup() filehandle in mode '$poll': $!,";
1090		1327
1091	# we assume CLOEXEC is already set by perl in all important cases	1328	# we assume CLOEXEC is already set by perl in all important cases
1092		1329
1093	($fh2, $rw)	1330	($fh2, $rw)
1094	}	1331	}
1095		1332
		1333	=head1 SIMPLIFIED AE API
		1334
		1335	Starting with version 5.0, AnyEvent officially supports a second, much
		1336	simpler, API that is designed to reduce the calling, typing and memory
		1337	overhead.
		1338
		1339	See the L<AE> manpage for details.
		1340
		1341	=cut
		1342
		1343	package AE;
		1344
		1345	our $VERSION = $AnyEvent::VERSION;
		1346
		1347	sub io($$$) {
		1348	AnyEvent->io (fh => $_[0], poll => $_[1] ? "w" : "r", cb => $_[2])
		1349	}
		1350
		1351	sub timer($$$) {
		1352	AnyEvent->timer (after => $_[0], interval => $_[1], cb => $_[2])
		1353	}
		1354
		1355	sub signal($$) {
		1356	AnyEvent->signal (signal => $_[0], cb => $_[1])
		1357	}
		1358
		1359	sub child($$) {
		1360	AnyEvent->child (pid => $_[0], cb => $_[1])
		1361	}
		1362
		1363	sub idle($) {
		1364	AnyEvent->idle (cb => $_[0])
		1365	}
		1366
		1367	sub cv(;&) {
		1368	AnyEvent->condvar (@_ ? (cb => $_[0]) : ())
		1369	}
		1370
		1371	sub now() {
		1372	AnyEvent->now
		1373	}
		1374
		1375	sub now_update() {
		1376	AnyEvent->now_update
		1377	}
		1378
		1379	sub time() {
		1380	AnyEvent->time
		1381	}
		1382
1096	package AnyEvent::Base;	1383	package AnyEvent::Base;
1097		1384
1098	# default implementations for many methods	1385	# default implementations for many methods
1099		1386
1100	BEGIN {	1387	sub _time() {
		1388	# probe for availability of Time::HiRes
1101	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {	1389	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {
		1390	warn "AnyEvent: using Time::HiRes for sub-second timing accuracy.\n" if $VERBOSE >= 8;
1102	*_time = \&Time::HiRes::time;	1391	*_time = \&Time::HiRes::time;
1103	# if (eval "use POSIX (); (POSIX::times())...	1392	# if (eval "use POSIX (); (POSIX::times())...
1104	} else {	1393	} else {
		1394	warn "AnyEvent: using built-in time(), WARNING, no sub-second resolution!\n" if $VERBOSE;
1105	*_time = sub { time }; # epic fail	1395	*_time = sub (){ time }; # epic fail
1106	}	1396	}
		1397
		1398	&_time
1107	}	1399	}
1108		1400
1109	sub time { _time }	1401	sub time { _time }
1110	sub now { _time }	1402	sub now { _time }
1111	sub now_update { }	1403	sub now_update { }
…		…
1116	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"	1408	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"
1117	}	1409	}
1118		1410
1119	# default implementation for ->signal	1411	# default implementation for ->signal
1120		1412
		1413	our $HAVE_ASYNC_INTERRUPT;
		1414
		1415	sub _have_async_interrupt() {
		1416	$HAVE_ASYNC_INTERRUPT = 1*(!$ENV{PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT}
		1417	&& eval "use Async::Interrupt 1.02 (); 1")
		1418	unless defined $HAVE_ASYNC_INTERRUPT;
		1419
		1420	$HAVE_ASYNC_INTERRUPT
		1421	}
		1422
1121	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);	1423	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);
		1424	our (%SIG_ASY, %SIG_ASY_W);
		1425	our ($SIG_COUNT, $SIG_TW);
1122		1426
1123	sub _signal_exec {	1427	sub _signal_exec {
		1428	$HAVE_ASYNC_INTERRUPT
		1429	? $SIGPIPE_R->drain
1124	sysread $SIGPIPE_R, my $dummy, 4;	1430	: sysread $SIGPIPE_R, (my $dummy), 9;
1125		1431
1126	while (%SIG_EV) {	1432	while (%SIG_EV) {
1127	for (keys %SIG_EV) {	1433	for (keys %SIG_EV) {
1128	delete $SIG_EV{$_};	1434	delete $SIG_EV{$_};
1129	$_->() for values %{ $SIG_CB{$_} || {} };	1435	$_->() for values %{ $SIG_CB{$_} || {} };
1130	}	1436	}
1131	}	1437	}
1132	}	1438	}
1133		1439
		1440	# install a dummy wakeup watcher to reduce signal catching latency
		1441	sub _sig_add() {
		1442	unless ($SIG_COUNT++) {
		1443	# try to align timer on a full-second boundary, if possible
		1444	my $NOW = AE::now;
		1445
		1446	$SIG_TW = AE::timer
		1447	$MAX_SIGNAL_LATENCY - ($NOW - int $NOW),
		1448	$MAX_SIGNAL_LATENCY,
		1449	sub { } # just for the PERL_ASYNC_CHECK
		1450	;
		1451	}
		1452	}
		1453
		1454	sub _sig_del {
		1455	undef $SIG_TW
		1456	unless --$SIG_COUNT;
		1457	}
		1458
		1459	our $_sig_name_init; $_sig_name_init = sub {
		1460	eval q{ # poor man's autoloading
		1461	undef $_sig_name_init;
		1462
		1463	if (_have_async_interrupt) {
		1464	*sig2num = \&Async::Interrupt::sig2num;
		1465	*sig2name = \&Async::Interrupt::sig2name;
		1466	} else {
		1467	require Config;
		1468
		1469	my %signame2num;
		1470	@signame2num{ split ' ', $Config::Config{sig_name} }
		1471	= split ' ', $Config::Config{sig_num};
		1472
		1473	my @signum2name;
		1474	@signum2name[values %signame2num] = keys %signame2num;
		1475
		1476	*sig2num = sub($) {
		1477	$_[0] > 0 ? shift : $signame2num{+shift}
		1478	};
		1479	*sig2name = sub ($) {
		1480	$_[0] > 0 ? $signum2name[+shift] : shift
		1481	};
		1482	}
		1483	};
		1484	die if $@;
		1485	};
		1486
		1487	sub sig2num ($) { &$_sig_name_init; &sig2num }
		1488	sub sig2name($) { &$_sig_name_init; &sig2name }
		1489
1134	sub signal {	1490	sub signal {
1135	my (undef, %arg) = @_;	1491	eval q{ # poor man's autoloading {}
		1492	# probe for availability of Async::Interrupt
		1493	if (_have_async_interrupt) {
		1494	warn "AnyEvent: using Async::Interrupt for race-free signal handling.\n" if $VERBOSE >= 8;
1136		1495
1137	unless ($SIGPIPE_R) {	1496	$SIGPIPE_R = new Async::Interrupt::EventPipe;
1138	require Fcntl;	1497	$SIG_IO = AE::io $SIGPIPE_R->fileno, 0, \&_signal_exec;
1139		1498
1140	if (AnyEvent::WIN32) {
1141	require AnyEvent::Util;
1142
1143	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
1144	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R) if $SIGPIPE_R;
1145	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W) if $SIGPIPE_W; # just in case
1146	} else {	1499	} else {
		1500	warn "AnyEvent: using emulated perl signal handling with latency timer.\n" if $VERBOSE >= 8;
		1501
		1502	require Fcntl;
		1503
		1504	if (AnyEvent::WIN32) {
		1505	require AnyEvent::Util;
		1506
		1507	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
		1508	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R, 1) if $SIGPIPE_R;
		1509	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W, 1) if $SIGPIPE_W; # just in case
		1510	} else {
1147	pipe $SIGPIPE_R, $SIGPIPE_W;	1511	pipe $SIGPIPE_R, $SIGPIPE_W;
1148	fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R;	1512	fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R;
1149	fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case	1513	fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case
1150		1514
1151	# not strictly required, as $^F is normally 2, but let's make sure...	1515	# not strictly required, as $^F is normally 2, but let's make sure...
1152	fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;	1516	fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
1153	fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;	1517	fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
		1518	}
		1519
		1520	$SIGPIPE_R
		1521	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";
		1522
		1523	$SIG_IO = AE::io $SIGPIPE_R, 0, \&_signal_exec;
1154	}	1524	}
1155		1525
1156	$SIGPIPE_R	1526	*signal = sub {
1157	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";	1527	my (undef, %arg) = @_;
1158		1528
1159	$SIG_IO = AnyEvent->io (fh => $SIGPIPE_R, poll => "r", cb => \&_signal_exec);
1160	}
1161
1162	my $signal = uc $arg{signal}	1529	my $signal = uc $arg{signal}
1163	or Carp::croak "required option 'signal' is missing";	1530	or Carp::croak "required option 'signal' is missing";
1164		1531
		1532	if ($HAVE_ASYNC_INTERRUPT) {
		1533	# async::interrupt
		1534
		1535	$signal = sig2num $signal;
1165	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};	1536	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
		1537
		1538	$SIG_ASY{$signal} ||= new Async::Interrupt
		1539	cb => sub { undef $SIG_EV{$signal} },
		1540	signal => $signal,
		1541	pipe => [$SIGPIPE_R->filenos],
		1542	pipe_autodrain => 0,
		1543	;
		1544
		1545	} else {
		1546	# pure perl
		1547
		1548	# AE::Util has been loaded in signal
		1549	$signal = sig2name $signal;
		1550	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
		1551
1166	$SIG{$signal} ||= sub {	1552	$SIG{$signal} ||= sub {
1167	local $!;	1553	local $!;
1168	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;	1554	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;
1169	undef $SIG_EV{$signal};	1555	undef $SIG_EV{$signal};
		1556	};
		1557
		1558	# can't do signal processing without introducing races in pure perl,
		1559	# so limit the signal latency.
		1560	_sig_add;
		1561	}
		1562
		1563	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
		1564	};
		1565
		1566	*AnyEvent::Base::signal::DESTROY = sub {
		1567	my ($signal, $cb) = @{$_[0]};
		1568
		1569	_sig_del;
		1570
		1571	delete $SIG_CB{$signal}{$cb};
		1572
		1573	$HAVE_ASYNC_INTERRUPT
		1574	? delete $SIG_ASY{$signal}
		1575	: # delete doesn't work with older perls - they then
		1576	# print weird messages, or just unconditionally exit
		1577	# instead of getting the default action.
		1578	undef $SIG{$signal}
		1579	unless keys %{ $SIG_CB{$signal} };
		1580	};
1170	};	1581	};
1171		1582	die if $@;
1172	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"	1583	&signal
1173	}
1174
1175	sub AnyEvent::Base::signal::DESTROY {
1176	my ($signal, $cb) = @{$_[0]};
1177
1178	delete $SIG_CB{$signal}{$cb};
1179
1180	# delete doesn't work with older perls - they then
1181	# print weird messages, or just unconditionally exit
1182	# instead of getting the default action.
1183	undef $SIG{$signal} unless keys %{ $SIG_CB{$signal} };
1184	}	1584	}
1185		1585
1186	# default implementation for ->child	1586	# default implementation for ->child
1187		1587
1188	our %PID_CB;	1588	our %PID_CB;
1189	our $CHLD_W;	1589	our $CHLD_W;
1190	our $CHLD_DELAY_W;	1590	our $CHLD_DELAY_W;
1191	our $WNOHANG;	1591	our $WNOHANG;
1192		1592
		1593	sub _emit_childstatus($$) {
		1594	my (undef, $rpid, $rstatus) = @_;
		1595
		1596	$_->($rpid, $rstatus)
		1597	for values %{ $PID_CB{$rpid} || {} },
		1598	values %{ $PID_CB{0} || {} };
		1599	}
		1600
1193	sub _sigchld {	1601	sub _sigchld {
		1602	my $pid;
		1603
		1604	AnyEvent->_emit_childstatus ($pid, $?)
1194	while (0 < (my $pid = waitpid -1, $WNOHANG)) {	1605	while ($pid = waitpid -1, $WNOHANG) > 0;
1195	$_->($pid, $?) for (values %{ $PID_CB{$pid} || {} }),
1196	(values %{ $PID_CB{0} || {} });
1197	}
1198	}	1606	}
1199		1607
1200	sub child {	1608	sub child {
1201	my (undef, %arg) = @_;	1609	my (undef, %arg) = @_;
1202		1610
1203	defined (my $pid = $arg{pid} + 0)	1611	defined (my $pid = $arg{pid} + 0)
1204	or Carp::croak "required option 'pid' is missing";	1612	or Carp::croak "required option 'pid' is missing";
1205		1613
1206	$PID_CB{$pid}{$arg{cb}} = $arg{cb};	1614	$PID_CB{$pid}{$arg{cb}} = $arg{cb};
1207		1615
		1616	# WNOHANG is almost cetrainly 1 everywhere
		1617	$WNOHANG ||= $^O =~ /^(?:openbsd|netbsd|linux|freebsd|cygwin|MSWin32)$/
		1618	? 1
1208	$WNOHANG ||= eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1;	1619	: eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1;
1209		1620
1210	unless ($CHLD_W) {	1621	unless ($CHLD_W) {
1211	$CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld);	1622	$CHLD_W = AE::signal CHLD => \&_sigchld;
1212	# child could be a zombie already, so make at least one round	1623	# child could be a zombie already, so make at least one round
1213	&_sigchld;	1624	&_sigchld;
1214	}	1625	}
1215		1626
1216	bless [$pid, $arg{cb}], "AnyEvent::Base::child"	1627	bless [$pid, $arg{cb}], "AnyEvent::Base::child"
…		…
1242	# never use more then 50% of the time for the idle watcher,	1653	# never use more then 50% of the time for the idle watcher,
1243	# within some limits	1654	# within some limits
1244	$w = 0.0001 if $w < 0.0001;	1655	$w = 0.0001 if $w < 0.0001;
1245	$w = 5 if $w > 5;	1656	$w = 5 if $w > 5;
1246		1657
1247	$w = AnyEvent->timer (after => $w, cb => $rcb);	1658	$w = AE::timer $w, 0, $rcb;
1248	} else {	1659	} else {
1249	# clean up...	1660	# clean up...
1250	undef $w;	1661	undef $w;
1251	undef $rcb;	1662	undef $rcb;
1252	}	1663	}
1253	};	1664	};
1254		1665
1255	$w = AnyEvent->timer (after => 0.05, cb => $rcb);	1666	$w = AE::timer 0.05, 0, $rcb;
1256		1667
1257	bless \\$cb, "AnyEvent::Base::idle"	1668	bless \\$cb, "AnyEvent::Base::idle"
1258	}	1669	}
1259		1670
1260	sub AnyEvent::Base::idle::DESTROY {	1671	sub AnyEvent::Base::idle::DESTROY {
…		…
1265		1676
1266	our @ISA = AnyEvent::CondVar::Base::;	1677	our @ISA = AnyEvent::CondVar::Base::;
1267		1678
1268	package AnyEvent::CondVar::Base;	1679	package AnyEvent::CondVar::Base;
1269		1680
1270	use overload	1681	#use overload
1271	'&{}' => sub { my $self = shift; sub { $self->send (@_) } },	1682	# '&{}' => sub { my $self = shift; sub { $self->send (@_) } },
1272	fallback => 1;	1683	# fallback => 1;
		1684
		1685	# save 300+ kilobytes by dirtily hardcoding overloading
		1686	${"AnyEvent::CondVar::Base::OVERLOAD"}{dummy}++; # Register with magic by touching.
		1687	*{'AnyEvent::CondVar::Base::()'} = sub { }; # "Make it findable via fetchmethod."
		1688	*{'AnyEvent::CondVar::Base::(&{}'} = sub { my $self = shift; sub { $self->send (@_) } }; # &{}
		1689	${'AnyEvent::CondVar::Base::()'} = 1; # fallback
		1690
		1691	our $WAITING;
1273		1692
1274	sub _send {	1693	sub _send {
1275	# nop	1694	# nop
1276	}	1695	}
1277		1696
…		…
1290	sub ready {	1709	sub ready {
1291	$_[0]{_ae_sent}	1710	$_[0]{_ae_sent}
1292	}	1711	}
1293		1712
1294	sub _wait {	1713	sub _wait {
		1714	$WAITING
		1715	and !$_[0]{_ae_sent}
		1716	and Carp::croak "AnyEvent::CondVar: recursive blocking wait detected";
		1717
		1718	local $WAITING = 1;
1295	AnyEvent->one_event while !$_[0]{_ae_sent};	1719	AnyEvent->one_event while !$_[0]{_ae_sent};
1296	}	1720	}
1297		1721
1298	sub recv {	1722	sub recv {
1299	$_[0]->_wait;	1723	$_[0]->_wait;
…		…
1301	Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak};	1725	Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak};
1302	wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0]	1726	wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0]
1303	}	1727	}
1304		1728
1305	sub cb {	1729	sub cb {
1306	$_[0]{_ae_cb} = $_[1] if @_ > 1;	1730	my $cv = shift;
		1731
		1732	@_
		1733	and $cv->{_ae_cb} = shift
		1734	and $cv->{_ae_sent}
		1735	and (delete $cv->{_ae_cb})->($cv);
		1736
1307	$_[0]{_ae_cb}	1737	$cv->{_ae_cb}
1308	}	1738	}
1309		1739
1310	sub begin {	1740	sub begin {
1311	++$_[0]{_ae_counter};	1741	++$_[0]{_ae_counter};
1312	$_[0]{_ae_end_cb} = $_[1] if @_ > 1;	1742	$_[0]{_ae_end_cb} = $_[1] if @_ > 1;
…		…
1361	C<PERL_ANYEVENT_MODEL>.	1791	C<PERL_ANYEVENT_MODEL>.
1362		1792
1363	When set to C<2> or higher, cause AnyEvent to report to STDERR which event	1793	When set to C<2> or higher, cause AnyEvent to report to STDERR which event
1364	model it chooses.	1794	model it chooses.
1365		1795
		1796	When set to C<8> or higher, then AnyEvent will report extra information on
		1797	which optional modules it loads and how it implements certain features.
		1798
1366	=item C<PERL_ANYEVENT_STRICT>	1799	=item C<PERL_ANYEVENT_STRICT>
1367		1800
1368	AnyEvent does not do much argument checking by default, as thorough	1801	AnyEvent does not do much argument checking by default, as thorough
1369	argument checking is very costly. Setting this variable to a true value	1802	argument checking is very costly. Setting this variable to a true value
1370	will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly	1803	will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly
1371	check the arguments passed to most method calls. If it finds any problems,	1804	check the arguments passed to most method calls. If it finds any problems,
1372	it will croak.	1805	it will croak.
1373		1806
1374	In other words, enables "strict" mode.	1807	In other words, enables "strict" mode.
1375		1808
1376	Unlike C<use strict>, it is definitely recommended to keep it off in	1809	Unlike C<use strict> (or it's modern cousin, C<< use L<common::sense>
1377	production. Keeping C<PERL_ANYEVENT_STRICT=1> in your environment while	1810	>>, it is definitely recommended to keep it off in production. Keeping
1378	developing programs can be very useful, however.	1811	C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs
		1812	can be very useful, however.
1379		1813
1380	=item C<PERL_ANYEVENT_MODEL>	1814	=item C<PERL_ANYEVENT_MODEL>
1381		1815
1382	This can be used to specify the event model to be used by AnyEvent, before	1816	This can be used to specify the event model to be used by AnyEvent, before
1383	auto detection and -probing kicks in. It must be a string consisting	1817	auto detection and -probing kicks in. It must be a string consisting
…		…
1426		1860
1427	=item C<PERL_ANYEVENT_MAX_FORKS>	1861	=item C<PERL_ANYEVENT_MAX_FORKS>
1428		1862
1429	The maximum number of child processes that C<AnyEvent::Util::fork_call>	1863	The maximum number of child processes that C<AnyEvent::Util::fork_call>
1430	will create in parallel.	1864	will create in parallel.
		1865
		1866	=item C<PERL_ANYEVENT_MAX_OUTSTANDING_DNS>
		1867
		1868	The default value for the C<max_outstanding> parameter for the default DNS
		1869	resolver - this is the maximum number of parallel DNS requests that are
		1870	sent to the DNS server.
		1871
		1872	=item C<PERL_ANYEVENT_RESOLV_CONF>
		1873
		1874	The file to use instead of F</etc/resolv.conf> (or OS-specific
		1875	configuration) in the default resolver. When set to the empty string, no
		1876	default config will be used.
		1877
		1878	=item C<PERL_ANYEVENT_CA_FILE>, C<PERL_ANYEVENT_CA_PATH>.
		1879
		1880	When neither C<ca_file> nor C<ca_path> was specified during
		1881	L<AnyEvent::TLS> context creation, and either of these environment
		1882	variables exist, they will be used to specify CA certificate locations
		1883	instead of a system-dependent default.
		1884
		1885	=item C<PERL_ANYEVENT_AVOID_GUARD> and C<PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT>
		1886
		1887	When these are set to C<1>, then the respective modules are not
		1888	loaded. Mostly good for testing AnyEvent itself.
1431		1889
1432	=back	1890	=back
1433		1891
1434	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE	1892	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE
1435		1893
…		…
1493	warn "read: $input\n"; # output what has been read	1951	warn "read: $input\n"; # output what has been read
1494	$cv->send if $input =~ /^q/i; # quit program if /^q/i	1952	$cv->send if $input =~ /^q/i; # quit program if /^q/i
1495	},	1953	},
1496	);	1954	);
1497		1955
1498	my $time_watcher; # can only be used once
1499
1500	sub new_timer {
1501	$timer = AnyEvent->timer (after => 1, cb => sub {	1956	my $time_watcher = AnyEvent->timer (after => 1, interval => 1, cb => sub {
1502	warn "timeout\n"; # print 'timeout' about every second	1957	warn "timeout\n"; # print 'timeout' at most every second
1503	&new_timer; # and restart the time
1504	});	1958	});
1505	}
1506
1507	new_timer; # create first timer
1508		1959
1509	$cv->recv; # wait until user enters /^q/i	1960	$cv->recv; # wait until user enters /^q/i
1510		1961
1511	=head1 REAL-WORLD EXAMPLE	1962	=head1 REAL-WORLD EXAMPLE
1512		1963
…		…
1643	through AnyEvent. The benchmark creates a lot of timers (with a zero	2094	through AnyEvent. The benchmark creates a lot of timers (with a zero
1644	timeout) and I/O watchers (watching STDOUT, a pty, to become writable,	2095	timeout) and I/O watchers (watching STDOUT, a pty, to become writable,
1645	which it is), lets them fire exactly once and destroys them again.	2096	which it is), lets them fire exactly once and destroys them again.
1646		2097
1647	Source code for this benchmark is found as F<eg/bench> in the AnyEvent	2098	Source code for this benchmark is found as F<eg/bench> in the AnyEvent
1648	distribution.	2099	distribution. It uses the L<AE> interface, which makes a real difference
		2100	for the EV and Perl backends only.
1649		2101
1650	=head3 Explanation of the columns	2102	=head3 Explanation of the columns
1651		2103
1652	I<watcher> is the number of event watchers created/destroyed. Since	2104	I<watcher> is the number of event watchers created/destroyed. Since
1653	different event models feature vastly different performances, each event	2105	different event models feature vastly different performances, each event
…		…
1674	watcher.	2126	watcher.
1675		2127
1676	=head3 Results	2128	=head3 Results
1677		2129
1678	name watchers bytes create invoke destroy comment	2130	name watchers bytes create invoke destroy comment
1679	EV/EV 400000 224 0.47 0.35 0.27 EV native interface	2131	EV/EV 100000 223 0.47 0.43 0.27 EV native interface
1680	EV/Any 100000 224 2.88 0.34 0.27 EV + AnyEvent watchers	2132	EV/Any 100000 223 0.48 0.42 0.26 EV + AnyEvent watchers
1681	CoroEV/Any 100000 224 2.85 0.35 0.28 coroutines + Coro::Signal	2133	Coro::EV/Any 100000 223 0.47 0.42 0.26 coroutines + Coro::Signal
1682	Perl/Any 100000 452 4.13 0.73 0.95 pure perl implementation	2134	Perl/Any 100000 431 2.70 0.74 0.92 pure perl implementation
1683	Event/Event 16000 517 32.20 31.80 0.81 Event native interface	2135	Event/Event 16000 516 31.16 31.84 0.82 Event native interface
1684	Event/Any 16000 590 35.85 31.55 1.06 Event + AnyEvent watchers	2136	Event/Any 16000 1203 42.61 34.79 1.80 Event + AnyEvent watchers
		2137	IOAsync/Any 16000 1911 41.92 27.45 16.81 via IO::Async::Loop::IO_Poll
		2138	IOAsync/Any 16000 1726 40.69 26.37 15.25 via IO::Async::Loop::Epoll
1685	Glib/Any 16000 1357 102.33 12.31 51.00 quadratic behaviour	2139	Glib/Any 16000 1118 89.00 12.57 51.17 quadratic behaviour
1686	Tk/Any 2000 1860 27.20 66.31 14.00 SEGV with >> 2000 watchers	2140	Tk/Any 2000 1346 20.96 10.75 8.00 SEGV with >> 2000 watchers
1687	POE/Event 2000 6328 109.99 751.67 14.02 via POE::Loop::Event	2141	POE/Any 2000 6951 108.97 795.32 14.24 via POE::Loop::Event
1688	POE/Select 2000 6027 94.54 809.13 579.80 via POE::Loop::Select	2142	POE/Any 2000 6648 94.79 774.40 575.51 via POE::Loop::Select
1689		2143
1690	=head3 Discussion	2144	=head3 Discussion
1691		2145
1692	The benchmark does I<not> measure scalability of the event loop very	2146	The benchmark does I<not> measure scalability of the event loop very
1693	well. For example, a select-based event loop (such as the pure perl one)	2147	well. For example, a select-based event loop (such as the pure perl one)
…		…
1705	benchmark machine, handling an event takes roughly 1600 CPU cycles with	2159	benchmark machine, handling an event takes roughly 1600 CPU cycles with
1706	EV, 3100 CPU cycles with AnyEvent's pure perl loop and almost 3000000 CPU	2160	EV, 3100 CPU cycles with AnyEvent's pure perl loop and almost 3000000 CPU
1707	cycles with POE.	2161	cycles with POE.
1708		2162
1709	C<EV> is the sole leader regarding speed and memory use, which are both	2163	C<EV> is the sole leader regarding speed and memory use, which are both
1710	maximal/minimal, respectively. Even when going through AnyEvent, it uses	2164	maximal/minimal, respectively. When using the L<AE> API there is zero
		2165	overhead (when going through the AnyEvent API create is about 5-6 times
		2166	slower, with other times being equal, so still uses far less memory than
1711	far less memory than any other event loop and is still faster than Event	2167	any other event loop and is still faster than Event natively).
1712	natively.
1713		2168
1714	The pure perl implementation is hit in a few sweet spots (both the	2169	The pure perl implementation is hit in a few sweet spots (both the
1715	constant timeout and the use of a single fd hit optimisations in the perl	2170	constant timeout and the use of a single fd hit optimisations in the perl
1716	interpreter and the backend itself). Nevertheless this shows that it	2171	interpreter and the backend itself). Nevertheless this shows that it
1717	adds very little overhead in itself. Like any select-based backend its	2172	adds very little overhead in itself. Like any select-based backend its
1718	performance becomes really bad with lots of file descriptors (and few of	2173	performance becomes really bad with lots of file descriptors (and few of
1719	them active), of course, but this was not subject of this benchmark.	2174	them active), of course, but this was not subject of this benchmark.
1720		2175
1721	The C<Event> module has a relatively high setup and callback invocation	2176	The C<Event> module has a relatively high setup and callback invocation
1722	cost, but overall scores in on the third place.	2177	cost, but overall scores in on the third place.
		2178
		2179	C<IO::Async> performs admirably well, about on par with C<Event>, even
		2180	when using its pure perl backend.
1723		2181
1724	C<Glib>'s memory usage is quite a bit higher, but it features a	2182	C<Glib>'s memory usage is quite a bit higher, but it features a
1725	faster callback invocation and overall ends up in the same class as	2183	faster callback invocation and overall ends up in the same class as
1726	C<Event>. However, Glib scales extremely badly, doubling the number of	2184	C<Event>. However, Glib scales extremely badly, doubling the number of
1727	watchers increases the processing time by more than a factor of four,	2185	watchers increases the processing time by more than a factor of four,
…		…
1788	In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100	2246	In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100
1789	(1%) are active. This mirrors the activity of large servers with many	2247	(1%) are active. This mirrors the activity of large servers with many
1790	connections, most of which are idle at any one point in time.	2248	connections, most of which are idle at any one point in time.
1791		2249
1792	Source code for this benchmark is found as F<eg/bench2> in the AnyEvent	2250	Source code for this benchmark is found as F<eg/bench2> in the AnyEvent
1793	distribution.	2251	distribution. It uses the L<AE> interface, which makes a real difference
		2252	for the EV and Perl backends only.
1794		2253
1795	=head3 Explanation of the columns	2254	=head3 Explanation of the columns
1796		2255
1797	I<sockets> is the number of sockets, and twice the number of "servers" (as	2256	I<sockets> is the number of sockets, and twice the number of "servers" (as
1798	each server has a read and write socket end).	2257	each server has a read and write socket end).
…		…
1805	it to another server. This includes deleting the old timeout and creating	2264	it to another server. This includes deleting the old timeout and creating
1806	a new one that moves the timeout into the future.	2265	a new one that moves the timeout into the future.
1807		2266
1808	=head3 Results	2267	=head3 Results
1809		2268
1810	name sockets create request	2269	name sockets create request
1811	EV 20000 69.01 11.16	2270	EV 20000 62.66 7.99
1812	Perl 20000 73.32 35.87	2271	Perl 20000 68.32 32.64
1813	Event 20000 212.62 257.32	2272	IOAsync 20000 174.06 101.15 epoll
1814	Glib 20000 651.16 1896.30	2273	IOAsync 20000 174.67 610.84 poll
		2274	Event 20000 202.69 242.91
		2275	Glib 20000 557.01 1689.52
1815	POE 20000 349.67 12317.24 uses POE::Loop::Event	2276	POE 20000 341.54 12086.32 uses POE::Loop::Event
1816		2277
1817	=head3 Discussion	2278	=head3 Discussion
1818		2279
1819	This benchmark I<does> measure scalability and overall performance of the	2280	This benchmark I<does> measure scalability and overall performance of the
1820	particular event loop.	2281	particular event loop.
…		…
1822	EV is again fastest. Since it is using epoll on my system, the setup time	2283	EV is again fastest. Since it is using epoll on my system, the setup time
1823	is relatively high, though.	2284	is relatively high, though.
1824		2285
1825	Perl surprisingly comes second. It is much faster than the C-based event	2286	Perl surprisingly comes second. It is much faster than the C-based event
1826	loops Event and Glib.	2287	loops Event and Glib.
		2288
		2289	IO::Async performs very well when using its epoll backend, and still quite
		2290	good compared to Glib when using its pure perl backend.
1827		2291
1828	Event suffers from high setup time as well (look at its code and you will	2292	Event suffers from high setup time as well (look at its code and you will
1829	understand why). Callback invocation also has a high overhead compared to	2293	understand why). Callback invocation also has a high overhead compared to
1830	the C<< $_->() for .. >>-style loop that the Perl event loop uses. Event	2294	the C<< $_->() for .. >>-style loop that the Perl event loop uses. Event
1831	uses select or poll in basically all documented configurations.	2295	uses select or poll in basically all documented configurations.
…		…
1943	As you can see, the AnyEvent + EV combination even beats the	2407	As you can see, the AnyEvent + EV combination even beats the
1944	hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl	2408	hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl
1945	backend easily beats IO::Lambda and POE.	2409	backend easily beats IO::Lambda and POE.
1946		2410
1947	And even the 100% non-blocking version written using the high-level (and	2411	And even the 100% non-blocking version written using the high-level (and
1948	slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda by a	2412	slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda
1949	large margin, even though it does all of DNS, tcp-connect and socket I/O	2413	higher level ("unoptimised") abstractions by a large margin, even though
1950	in a non-blocking way.	2414	it does all of DNS, tcp-connect and socket I/O in a non-blocking way.
1951		2415
1952	The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and	2416	The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and
1953	F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are	2417	F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are
1954	part of the IO::lambda distribution and were used without any changes.	2418	part of the IO::Lambda distribution and were used without any changes.
1955		2419
1956		2420
1957	=head1 SIGNALS	2421	=head1 SIGNALS
1958		2422
1959	AnyEvent currently installs handlers for these signals:	2423	AnyEvent currently installs handlers for these signals:
…		…
1963	=item SIGCHLD	2427	=item SIGCHLD
1964		2428
1965	A handler for C<SIGCHLD> is installed by AnyEvent's child watcher	2429	A handler for C<SIGCHLD> is installed by AnyEvent's child watcher
1966	emulation for event loops that do not support them natively. Also, some	2430	emulation for event loops that do not support them natively. Also, some
1967	event loops install a similar handler.	2431	event loops install a similar handler.
		2432
		2433	Additionally, when AnyEvent is loaded and SIGCHLD is set to IGNORE, then
		2434	AnyEvent will reset it to default, to avoid losing child exit statuses.
1968		2435
1969	=item SIGPIPE	2436	=item SIGPIPE
1970		2437
1971	A no-op handler is installed for C<SIGPIPE> when C<$SIG{PIPE}> is C<undef>	2438	A no-op handler is installed for C<SIGPIPE> when C<$SIG{PIPE}> is C<undef>
1972	when AnyEvent gets loaded.	2439	when AnyEvent gets loaded.
…		…
1984		2451
1985	=back	2452	=back
1986		2453
1987	=cut	2454	=cut
1988		2455
		2456	undef $SIG{CHLD}
		2457	if $SIG{CHLD} eq 'IGNORE';
		2458
1989	$SIG{PIPE} = sub { }	2459	$SIG{PIPE} = sub { }
1990	unless defined $SIG{PIPE};	2460	unless defined $SIG{PIPE};
1991		2461
		2462	=head1 RECOMMENDED/OPTIONAL MODULES
		2463
		2464	One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and
		2465	it's built-in modules) are required to use it.
		2466
		2467	That does not mean that AnyEvent won't take advantage of some additional
		2468	modules if they are installed.
		2469
		2470	This section explains which additional modules will be used, and how they
		2471	affect AnyEvent's operation.
		2472
		2473	=over 4
		2474
		2475	=item L<Async::Interrupt>
		2476
		2477	This slightly arcane module is used to implement fast signal handling: To
		2478	my knowledge, there is no way to do completely race-free and quick
		2479	signal handling in pure perl. To ensure that signals still get
		2480	delivered, AnyEvent will start an interval timer to wake up perl (and
		2481	catch the signals) with some delay (default is 10 seconds, look for
		2482	C<$AnyEvent::MAX_SIGNAL_LATENCY>).
		2483
		2484	If this module is available, then it will be used to implement signal
		2485	catching, which means that signals will not be delayed, and the event loop
		2486	will not be interrupted regularly, which is more efficient (and good for
		2487	battery life on laptops).
		2488
		2489	This affects not just the pure-perl event loop, but also other event loops
		2490	that have no signal handling on their own (e.g. Glib, Tk, Qt).
		2491
		2492	Some event loops (POE, Event, Event::Lib) offer signal watchers natively,
		2493	and either employ their own workarounds (POE) or use AnyEvent's workaround
		2494	(using C<$AnyEvent::MAX_SIGNAL_LATENCY>). Installing L<Async::Interrupt>
		2495	does nothing for those backends.
		2496
		2497	=item L<EV>
		2498
		2499	This module isn't really "optional", as it is simply one of the backend
		2500	event loops that AnyEvent can use. However, it is simply the best event
		2501	loop available in terms of features, speed and stability: It supports
		2502	the AnyEvent API optimally, implements all the watcher types in XS, does
		2503	automatic timer adjustments even when no monotonic clock is available,
		2504	can take avdantage of advanced kernel interfaces such as C<epoll> and
		2505	C<kqueue>, and is the fastest backend I<by far>. You can even embed
		2506	L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>).
		2507
		2508	=item L<Guard>
		2509
		2510	The guard module, when used, will be used to implement
		2511	C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a
		2512	lot less memory), but otherwise doesn't affect guard operation much. It is
		2513	purely used for performance.
		2514
		2515	=item L<JSON> and L<JSON::XS>
		2516
		2517	One of these modules is required when you want to read or write JSON data
		2518	via L<AnyEvent::Handle>. It is also written in pure-perl, but can take
		2519	advantage of the ultra-high-speed L<JSON::XS> module when it is installed.
		2520
		2521	In fact, L<AnyEvent::Handle> will use L<JSON::XS> by default if it is
		2522	installed.
		2523
		2524	=item L<Net::SSLeay>
		2525
		2526	Implementing TLS/SSL in Perl is certainly interesting, but not very
		2527	worthwhile: If this module is installed, then L<AnyEvent::Handle> (with
		2528	the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL.
		2529
		2530	=item L<Time::HiRes>
		2531
		2532	This module is part of perl since release 5.008. It will be used when the
		2533	chosen event library does not come with a timing source on it's own. The
		2534	pure-perl event loop (L<AnyEvent::Impl::Perl>) will additionally use it to
		2535	try to use a monotonic clock for timing stability.
		2536
		2537	=back
		2538
1992		2539
1993	=head1 FORK	2540	=head1 FORK
1994		2541
1995	Most event libraries are not fork-safe. The ones who are usually are	2542	Most event libraries are not fork-safe. The ones who are usually are
1996	because they rely on inefficient but fork-safe C<select> or C<poll>	2543	because they rely on inefficient but fork-safe C<select> or C<poll> calls
1997	calls. Only L<EV> is fully fork-aware.	2544	- higher performance APIs such as BSD's kqueue or the dreaded Linux epoll
		2545	are usually badly thought-out hacks that are incompatible with fork in
		2546	one way or another. Only L<EV> is fully fork-aware and ensures that you
		2547	continue event-processing in both parent and child (or both, if you know
		2548	what you are doing).
		2549
		2550	This means that, in general, you cannot fork and do event processing in
		2551	the child if the event library was initialised before the fork (which
		2552	usually happens when the first AnyEvent watcher is created, or the library
		2553	is loaded).
1998		2554
1999	If you have to fork, you must either do so I<before> creating your first	2555	If you have to fork, you must either do so I<before> creating your first
2000	watcher OR you must not use AnyEvent at all in the child.	2556	watcher OR you must not use AnyEvent at all in the child OR you must do
		2557	something completely out of the scope of AnyEvent.
		2558
		2559	The problem of doing event processing in the parent I<and> the child
		2560	is much more complicated: even for backends that I<are> fork-aware or
		2561	fork-safe, their behaviour is not usually what you want: fork clones all
		2562	watchers, that means all timers, I/O watchers etc. are active in both
		2563	parent and child, which is almost never what you want. USing C<exec>
		2564	to start worker children from some kind of manage rprocess is usually
		2565	preferred, because it is much easier and cleaner, at the expense of having
		2566	to have another binary.
2001		2567
2002		2568
2003	=head1 SECURITY CONSIDERATIONS	2569	=head1 SECURITY CONSIDERATIONS
2004		2570
2005	AnyEvent can be forced to load any event model via	2571	AnyEvent can be forced to load any event model via
…		…
2043	L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.	2609	L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.
2044		2610
2045	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,	2611	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,
2046	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,	2612	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,
2047	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,	2613	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,
2048	L<AnyEvent::Impl::POE>.	2614	L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>, L<Anyevent::Impl::Irssi>.
2049		2615
2050	Non-blocking file handles, sockets, TCP clients and	2616	Non-blocking file handles, sockets, TCP clients and
2051	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>.	2617	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.
2052		2618
2053	Asynchronous DNS: L<AnyEvent::DNS>.	2619	Asynchronous DNS: L<AnyEvent::DNS>.
2054		2620
2055	Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>,	2621	Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>,
		2622	L<Coro::Event>,
2056		2623
2057	Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>, L<AnyEvent::DNS>.	2624	Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::XMPP>,
		2625	L<AnyEvent::HTTP>.
2058		2626
2059		2627
2060	=head1 AUTHOR	2628	=head1 AUTHOR
2061		2629
2062	Marc Lehmann <schmorp@schmorp.de>	2630	Marc Lehmann <schmorp@schmorp.de>

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